Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to the U.S. Navy Training and Testing Activities in the Hawaii-Southern California Training and Testing Study Area, 68290-68367 [2023-21499]

Download as PDF 68290 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 218 [Docket No. 230817–0197] RIN 0648–BL72 Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to the U.S. Navy Training and Testing Activities in the HawaiiSouthern California Training and Testing Study Area National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION: Proposed rule; request for comments and information. AGENCY: NMFS has received a request from the U.S. Navy (Navy) to modify the regulations and Letters of Authorization (LOAs) authorizing the take of marine mammals incidental to Navy training and testing activities conducted in the Hawaii-Southern California Training and Testing (HSTT) Study Area between 2018 and 2025. In 2021, two separate U.S. Navy vessels struck unidentified large whales on two separate occasions, one whale in June 2021 and one whale in July 2021, in waters off Southern California. The takes by vessel strike of the two whales by the U.S. Navy were covered by the existing regulations and LOAs, which authorize the U.S. Navy to take up to three large whales by serious injury or mortality by vessel strike between 2018 and 2025. The Navy reanalyzed the potential of vessel strike in the HSTT Study Area, including the recent strikes and as a result, requested two additional takes of large whales by serious injury or mortality by vessel strike for the remainder of the current regulatory period. In May 2023, a U.S. Navy vessel struck a large whale in waters off Southern California. NMFS reanalyzed the potential for vessel strike following the May 2023 strike and proposes to authorize two additional takes of large whales by serious injury or mortality by vessel strike for the remainder of the current regulatory period (two takes in addition to the three takes authorized in the current regulations). Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on the proposed promulgation of modified regulations and associated LOAs for the Navy governing this additional incidental taking of marine mammals. NMFS will consider public comments prior to ddrumheller on DSK120RN23PROD with PROPOSALS2 SUMMARY: VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 issuing any final rule and making final decisions on the issuance of the requested LOAs. Agency responses to public comments will be provided in the notice of the final decision. The Navy’s activities qualify as military readiness activities pursuant to the MMPA, as amended by the National Defense Authorization Act for Fiscal Year 2004 (2004 NDAA). DATES: Comments and information must be received no later than November 17, 2023. ADDRESSES: Submit all electronic public comments via the Federal e-Rulemaking Portal. Go to https:// www.regulations.gov and enter NOAA– NMFS–2023–0102 in the Search box. Click on the ‘‘Comment’’ icon, complete the required fields, and enter or attach your comments. Instructions: Comments sent by any other method, to any other address or individual, or received after the end of the comment period may not be considered by NMFS. All comments received are a part of the public record and will generally be posted for public viewing on www.regulations.gov without change. All personal identifying information (e.g., name, address), confidential business information, or otherwise sensitive information submitted voluntarily by the sender will be publicly accessible. NMFS will accept anonymous comments (enter ‘‘N/ A’’ in the required fields if you wish to remain anonymous). A copy of the Navy’s applications, NMFS’ proposed and final rules and subsequent LOAs for the existing (2020) and previous (2018) regulations, and other supporting documents and documents cited herein may be obtained online at: www.fisheries.noaa.gov/ national/marine-mammal-protection/ incidental-take-authorizations-militaryreadiness-activities. In case of problems accessing these documents, please use the contact listed here (see FOR FURTHER INFORMATION CONTACT). FOR FURTHER INFORMATION CONTACT: Leah Davis, Office of Protected Resources, NMFS, (301) 427–8401. SUPPLEMENTARY INFORMATION: Purpose of Regulatory Action These proposed regulations, issued under the authority of the MMPA (16 U.S.C. 1361 et seq.), would modify the current regulations, which allow for the authorization of take of marine mammals incidental to the Navy’s training and testing activities (which qualify as military readiness activities) from the use of sonar and other transducers, in-water detonations, air guns, impact pile driving/vibratory PO 00000 Frm 00002 Fmt 4701 Sfmt 4702 extraction, and the movement of vessels throughout the HSTT Study Area (50 CFR part 218, subpart H; hereafter ‘‘2020 HSTT regulations’’). NMFS received a request from the Navy to modify the existing regulations and LOAs to authorize two additional takes of large whales by serious injury or mortality by vessel strike over the remainder of the HSTT regulatory period. The current HSTT regulations and LOAs authorize the incidental take, by serious injury or mortality, of three large whales by vessel strike. Here, in consideration of the best available science, including updated information related to vessel strikes, NMFS analyzes and proposes to authorize the incidental serious injury or mortality by vessel strike of five large whales over the effective period of the regulations (December 2018–December 2025). The effective period remains unchanged from the existing regulations. Further, the Navy’s proposed activities remain unchanged; however, this proposed rule includes two additional mitigation measures and revision of two existing mitigation measures to further reduce the probability of vessel strike. With the exception of these new mitigation measures and revisions to two existing mitigation measures, the required mitigation and monitoring measures remain unchanged. Background The MMPA prohibits the ‘‘take’’ of marine mammals, with certain exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) direct the Secretary of Commerce (as delegated to NMFS) to allow, upon request, the incidental, but not intentional, taking of small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and either regulations are issued or, if the taking is limited to harassment, the public is provided with notice of the proposed incidental take authorization and the opportunity to review and submit comments. An authorization for incidental takings shall be granted if NMFS finds that the taking will have a negligible impact on the species or stock(s) and will not have an unmitigable adverse impact on the availability of the species or stock(s) for taking for subsistence uses (where relevant). Further, NMFS must prescribe the permissible methods of taking and other means of effecting the least practicable adverse impact on the affected species or stocks and their habitat, paying particular attention to rookeries, mating grounds, and areas of E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules similar significance, and on the availability of such species or stocks for taking for certain subsistence uses (referred to in this rulemaking as ‘‘mitigation measures’’); and requirements pertaining to the monitoring and reporting of such takings. The MMPA defines ‘‘take’’ to mean to harass, hunt, capture, or kill, or attempt to harass, hunt, capture, or kill any marine mammal. The Preliminary Analysis and Negligible Impact Determination section below discusses the definition of ‘‘negligible impact.’’ The 2004 NDAA (Pub. L. 108–136) amended section 101(a)(5) of the MMPA to remove the ‘‘small numbers’’ and ‘‘specified geographical region’’ provisions indicated above and amended the definition of ‘‘harassment’’ as applied to a ‘‘military readiness activity.’’ The definition of harassment for military readiness activities (section 3(18)(B) of the MMPA) is (i) any act that injures or has the significant potential to injure a marine mammal or marine mammal stock in the wild (Level A Harassment); or (ii) any act that disturbs or is likely to disturb a marine mammal or marine mammal stock in the wild by causing disruption of natural behavioral patterns, including, but not limited to, migration, surfacing, nursing, breeding, feeding, or sheltering, to a point where such behavioral patterns are abandoned or significantly altered (Level B harassment). In addition, the 2004 NDAA amended the MMPA as it relates to military readiness activities such that the least practicable adverse impact analysis shall include consideration of personnel safety, practicality of implementation, and impact on the effectiveness of the military readiness activity. The NDAA for Fiscal Year 2019 (2019 NDAA) (Pub. L. 115–232), amended the MMPA to allow incidental take rules for military readiness activities under section 101(a)(5)(A) to be issued for up to 7 years. Prior to this amendment, all incidental take rules under section 101(a)(5)(A) were limited to 5 years. Under the MMPA implementing regulations, incidental take regulations may be modified, in whole or in part, as new information is developed and after notice and opportunity for public comment (50 CFR 216.105). An LOA must be withdrawn or suspended if, after notice and opportunity for public comment, NMFS determines that the regulations are not being substantially complied with, or the taking is having, or may have, more than a negligible impact on species or stock. Id. at 216.106(e). Note, in its application, Navy relied on §§ 218.76, and 218.77. These sections outline the process for VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 modification of an LOA without modifying the applicable incidental take regulation. These sections do not apply here because the Navy requested modification of the 2020 HSTT regulations. Summary of Request On December 27, 2018, NMFS issued a 5-year final rule governing the taking of marine mammals incidental to Navy training and testing activities conducted in the HSTT Study Area (83 FR 66846; hereafter ‘‘2018 HSTT final rule’’). Previously, on August 13, 2018, and towards the end of the time period in which NMFS was processing the Navy’s request for the 2018 regulations, the 2019 NDAA amended the MMPA for military readiness activities to allow incidental take regulations to be issued for up to 7 years instead of the previous 5 years. The Navy’s training and testing activities conducted in the HSTT Study Area qualify as military readiness activities pursuant to the MMPA, as amended by the 2004 NDAA. On March 11, 2019, the Navy submitted an application requesting that NMFS extend the 2018 HSTT regulations and associated LOAs such that they would cover take incidental to 7 years of training and testing activities instead of 5, extending the expiration date from December 20, 2023 to December 20, 2025. On July 10, 2020, NOAA Fisheries issued regulations to govern the taking of marine mammals incidental to the training and testing activities conducted in the HSTT Study Area over the course of 7 years, effectively extending the effective period from December 20, 2023 to December 20, 2025. On March 31, 2022, NMFS received an adequate and complete application (2022 Navy application) from the Navy requesting that NMFS modify the existing regulations and LOAs to authorize two additional takes of large whales by serious injury or mortality by vessel strike over the remainder of the HSTT authorization period. The 2020 HSTT regulations (50 CFR part 218, subpart H) and LOAs authorize the take of marine mammals from the Navy’s training and testing activities in the HSTT Study Area through December 20, 2025. These regulations and LOAs authorize the take of three large whales by serious injury or mortality by vessel strike. The Navy’s 2022 request is based upon new information regarding U.S. Navy vessel strikes off the coast of Southern California. As described in the 2022 Navy application, in 2021, two separate U.S. Navy vessels struck unidentified large whales off the coast of Southern California on two separate PO 00000 Frm 00003 Fmt 4701 Sfmt 4702 68291 occasions, one whale in June 2021 and one whale in July 2021. Separately, a foreign naval vessel struck two fin whales off the coast of Southern California in May 2021. In the 2022 Navy application, the Navy proposes no changes to the nature of the specified activities covered by the 2020 HSTT final rule. The Navy states that the level of activity within and between years would be consistent with that previously analyzed in the 2020 HSTT final rule, and all activities would be conducted within the same boundaries of the HSTT Study Area identified in the 2020 HSTT final rule. The training and testing activities (e.g., equipment and sources used, exercises conducted) are identical to those described and analyzed in the 2020 HSTT final rule, and the mitigation, monitoring, and reporting measures are similar to those described and analyzed in the 2020 HSTT final rule. The only changes included in the Navy’s request are for additional take by serious injury or mortality by vessel strike. The Navy’s mission is to organize, train, equip, and maintain combat-ready naval forces capable of winning wars, deterring aggression, and maintaining freedom of the seas. This mission is mandated by Federal law (10 U.S.C. 8062), which ensures the readiness of the naval forces of the United States. The Navy executes this responsibility by establishing and executing training programs, including at-sea training and exercises, and ensuring naval forces have access to the ranges, operating areas (OPAREAs), and airspace needed to develop and maintain skills for conducting naval activities. For a summary of the training and testing activities within the HSTT Study Area, see the Navy’s previous rulemaking and LOA applications submitted for HSTT Phase III activities (October 13, 2017 initial rulemaking and LOA application (hereafter ‘‘2017 Navy application’’) and March 11, 2019 extension rulemaking and LOA application (hereafter ‘‘2019 Navy application’’)) and the 2020 HSTT regulations that were subsequently promulgated, which can be found at: https://www.fisheries.noaa.gov/ national/marine-mammal-protection/ incidental-take-authorizations-militaryreadiness-activities. These activities are deemed by the Navy necessary to accomplish military readiness requirements and are anticipated to continue into the reasonably foreseeable future. The 2022 Navy application and this proposed rule cover training and testing activities that would occur over the remainder of the effective period of the current regulations, valid from the E:\FR\FM\03OCP2.SGM 03OCP2 68292 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules ddrumheller on DSK120RN23PROD with PROPOSALS2 publication date of the final rule, if issued, through December 20, 2025. Summary of the Proposed Regulations NMFS is proposing to modify the incidental take regulations and associated LOAs to cover the same Navy activities covered by the 2020 HSTT regulations but authorize five takes of large whales by serious injury or mortality by vessel strike (two takes in addition to the three takes authorized in the current regulations). In its 2022 application, the Navy proposes no additional changes and explains that its training and testing activities, including the level of vessel use, remain unchanged. Nearly all mitigation, monitoring, and reporting measures remain unchanged with the exception of two additional mitigation measures, revision of two existing mitigation measures, and an additional reporting measure resulting from discussions between the Navy and NMFS. In response to the Navy’s request, we focus our analysis on the new information related to vessel strike. We also review any new information that may be pertinent to our analysis of the impacts from all other activities that comprise Navy’s specified activity, and our analysis of mitigation, monitoring, and reporting. Where there is any new information pertinent to the descriptions, analyses, or findings required to authorize the incidental take for military readiness activities under MMPA section 101(a)(5)(A), that information is provided in the appropriate sections below. Where there is no new information or any new information does not change our previous analysis or findings, we indicate as such and refer the reader to the original analysis in the 2018 HSTT proposed and final rule, 2020 HSTT final rule or the 2019 HSTT Final Environmental Impact Statement (FEIS)/ Overseas Environmental Impact Statement (OEIS). After reviewing all new information and as discussed below, we largely find that our previous analyses and findings remain current and applicable. For vessel strike, we provide a new analysis and propose authorizing two additional takes of large whales, for a total of five takes by serious injury or mortality by vessel strike over the 7-year period. We consider authorizing these additional takes after analyzing the best available information and after considering the effects of the entire specified activity and the total taking as required by MMPA section 101(a)(5)(A). When setting forth the permissible methods of taking pursuant to the activity and other means of effecting the least practicable VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 adverse impact on the species or stock, we propose requiring new and modified mitigation and also consider whether to require any new or modified mitigation for the entire specified activity. The proposed regulatory language included at the end of this proposed rule, which would be published at 50 CFR part 218, subpart H, remains largely the same as that under the HSTT 2020 regulations, except for a small number of technical changes related to the Navy’s 2022 request, new and revised mitigation measures, and a new reporting measure. Therefore, in this proposed rule, we refer the reader to complete analyses described in the 2018 HSTT final rule or an updated analysis in the 2020 HSTT final rule, where appropriate. Below is a list of the regulatory documents referenced in this proposed rule. The list indicates the short name by which the document is referenced in this proposed rule as well as the full titles of the cited documents. All of the documents can be found at: www.fisheries.noaa.gov/national/ marine-mammal-protection/incidentaltake-authorizations-military-readinessactivities and https://www.hstteis.com/. • NMFS June 26, 2018, HawaiiSouthern California Training and Testing (HSTT) proposed rule (83 FR 29872; 2018 HSTT proposed rule); • NMFS December 27, 2018, HawaiiSouthern California Training and Testing (HSTT) final rule (83 FR 66846; 2018 HSTT final rule); • NMFS September 13, 2019, HawaiiSouthern California Training and Testing (HSTT) proposed rule (84 FR 48388; 2019 HSTT proposed rule); • NMFS July 10, 2020, HawaiiSouthern California Training and Testing (HSTT) final rule (85 FR 41780; 2020 HSTT final rule); • Navy October 13, 2017, MMPA rulemaking and LOA application (2017 Navy application); • Navy March 11, 2019, MMPA rulemaking and LOA extension application (2019 Navy application); • Navy March 31, 2022, MMPA rulemaking and LOA revision application (2022 Navy application); and • October 26, 2018, Hawaii-Southern California Training and Testing (HSTT) Final Environmental Impact Statement/ Overseas Environmental Impact Statement (FEIS/OEIS) (2018 HSTT FEIS/OEIS). Description of the Specified Activity The Navy requests authorization to take marine mammals incidental to conducting training and testing activities. The Navy has determined that PO 00000 Frm 00004 Fmt 4701 Sfmt 4702 acoustic and explosives stressors are most likely to result in impacts on marine mammals that could rise to the level of harassment. In addition to take by harassment, the Navy has determined that vessel movement may result in serious injury or mortality to marine mammals. Detailed descriptions of these activities are provided in chapter 2 of the 2018 HSTT FEIS/OEIS and in the 2017 Navy application. Overview of Training and Testing Activities The Navy routinely trains in the HSTT Study Area in preparation for national defense missions. Training and testing activities and components covered in the 2022 Navy application are described in detail in the Overview of Training and Testing Activities sections of the 2018 HSTT proposed rule, the 2018 HSTT final rule, and chapter 2 (Description of Proposed Action and Alternatives) of the 2018 HSTT FEIS/OEIS (https:// www.hstteis.com/). Each military training and testing activity described meets mandated Fleet requirements to deploy ready forces. The Navy proposes no changes to the specified activities described and analyzed in the 2018 HSTT final rule and subsequent 2020 HSTT final rule. The boundaries of the HSTT Study Area (see figure 2–1 of the 2019 Navy application); the dates and duration of the activities; and the training and testing activities (e.g., equipment and sources used, exercises conducted) analyzed in this proposed rule are identical to those described and analyzed in the 2020 HSTT final rule and therefore, are not repeated herein. Please see the 2020 HSTT final rule for more information. The manner of vessel movement presented in this proposed rule is also identical to that analyzed in the 2020 HSTT final rule. Vessel Strike Vessel strikes are not specific to any particular training or testing activity but rather, a limited, sporadic, and incidental result of Navy vessel movement within the HSTT Study Area. Vessel strikes from commercial, recreational, and military vessels are known to seriously injure and occasionally kill cetaceans (Abramson et al. 2011; Berman-Kowalewski et al. 2010; Calambokidis, 2012; Douglas et al. 2008; Laggner, 2009; Lammers et al. 2003; Van der Hoop et al. 2012; Van der Hoop et al. 2013; Crum et al. 2019), although reviews of the literature on vessel strikes mainly involve collisions between commercial vessels and whales (Jensen and Silber, 2003; Laist et al. 2001). Vessel speed, size, and mass are E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules all important factors in determining both the potential likelihood and impacts of a vessel strike to marine mammals (Conn and Silber, 2013; Gende et al. 2011; Silber et al. 2010; Vanderlaan and Taggart, 2007; Wiley et al. 2016). For large vessels, speed and angle of approach can influence the severity of a strike. Navy vessels transit at speeds that are optimal for fuel conservation or to meet training and testing requirements. Small craft (for purposes of this analysis, less than 18 m in length) have much more variable speeds (0–50+ knots (kn; 0–92.6 kilometers (km) per hour), dependent on the activity). Submarines generally operate at speeds in the range of 8–13 kn (14.8–24.1 km per hour), and the average speed of large Navy ships range between 10 and 15 kn (18.5 and 27.8 km per hour). While these speeds are considered averages and representative of most events, some vessels need to operate outside of these parameters for certain times or during certain activities. For example, to produce the required relative wind speed over the flight deck, an aircraft carrier engaged in flight operations must adjust its speed through the water accordingly. Also, there are other instances such as launch and recovery of a small rigid hull inflatable boat; vessel boarding, search, and seizure training events; or retrieval of a target when vessels would be dead in the water or moving slowly ahead to maintain steerage. There are a few specific events, including high-speed tests of newly constructed vessels, where vessels would operate at higher speeds. By comparison, this is slower than most commercial vessels where full speed for a container ship is typically 24 kn (44.4 km per hour; Bonney and Leach, 2010). Large Navy vessels (greater than 18 m in length) within the offshore areas of range complexes and testing ranges operate differently from commercial vessels in ways that may reduce the probability of whale collisions. Surface ships operated by or for the Navy have multiple personnel assigned to stand watch at all times when a ship or surfaced submarine is moving through the water (underway). A primary duty of personnel standing watch on surface ships is to detect and report all objects and disturbances sighted in the water that may indicate a threat to the vessel and its crew, such as debris, a periscope, surfaced submarine, or surface disturbance. Per vessel safety requirements, personnel standing watch also report any marine mammals sighted in the path of the vessel as a standard collision avoidance procedure. All vessels proceed at a safe speed so they VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 can take proper and effective action to avoid a collision with any sighted object or disturbance and can be stopped within a distance appropriate to the prevailing circumstances and conditions. As described in the Standard Operating Procedures section, the Navy utilizes Lookouts to avoid collisions, and Lookouts are also trained to spot marine mammals so that vessels may change course or take other appropriate action to avoid collisions. Should a vessel strike occur, we consider that it would likely result in incidental take in the form of serious injury and/or mortality and, accordingly, for the purposes of the analysis, we assume that any vessel strike would result in serious injury or mortality. The Navy proposes no changes to the nature of the specified activities, the training and testing activities, the manner of vessel movement, the speeds at which vessels operate, the number of vessels that would be used during various activities, or the locations in which Navy vessel activity would be concentrated within the HSTT Study Area described in the 2018 HSTT final rule and referenced in the 2020 HSTT final rule. Vessel Movement Vessels used as part of the planned activities include ships, submarines, unmanned vessels, and boats ranging in size from small, 22 ft (7 m) rigid hull inflatable boats to aircraft carriers with lengths up to 1,092 ft (333 m). The average speed of large Navy ships ranges between 10 and 15 kn (18.5 and 27.8 km per hour) and submarines generally operate at speeds in the range of 8–13 kn (14.8–24.1 km per hour) while a few specialized vessels can travel at faster speeds. Small craft (for purposes of this analysis, less than 18 m in length) have much more variable speeds (0–50+ kn (0–92.6 km per hour), dependent on the activity) but generally range from 10 to 14 kn (18.5 to 25.9 km per hour). From unpublished Navy data, average median speed for large Navy ships in the HSTT Study Area from 2011–2015 varied from 5–10 kn (9.2–18.5 km per hour) with variations by ship class and location (i.e., slower speeds close to the coast). While these speeds for large and small craft are representative of most events, some vessels need to temporarily operate outside of these parameters. Typical speed of Navy vessels in HSTT core high use areas from 2014–2018 were between 10 and 15 kn (18.5 and 27.8 km per hour; Starcovic and Mintz 2021). This core area is a region including the approaches to San Diego, and immediate offshore areas west of PO 00000 Frm 00005 Fmt 4701 Sfmt 4702 68293 San Diego, centered north and south of San Clemente Island. A full description of Navy vessels that are used during training and testing activities can be found in the 2017 Navy application and chapter 2 (Description of Proposed Action and Alternatives) of the 2018 HSTT FEIS/OEIS. The number of Navy vessels used in the HSTT Study Area varies based on military training and testing requirements, deployment schedules, annual budgets, and other dynamic factors. Most training and testing activities involve the use of vessels. These activities could be widely dispersed throughout the HSTT Study Area but would typically be conducted near naval ports, piers, and range areas. Navy vessel traffic would be especially concentrated near San Diego, California and Pearl Harbor, Hawaii. Based on historical data, we anticipate the annual number of at-sea hours by U.S. Navy vessels in the HSTT action area will be around 26,800 hours per year (Starcovic and Mintz 2021). We expect that about 25 percent of this vessel activity would occur within the Hawaii Range Complex (HRC) and 75 percent within the Southern California Range Complex (SOCAL; Mintz 2016). There is no seasonal differentiation in Navy vessel use because of continual operational requirements from Combatant Commanders. The majority of large vessel traffic occurs between the installations and the OPAREAs. The transit corridor, notionally defined by the great circle route (e.g., shortest distance) from San Diego to the center of the HRC, as depicted in the 2018 HSTT FEIS/OEIS, is generally used by ships transiting between SOCAL and HRC. While in transit, ships and aircraft would, at times, conduct basic and routine unit-level activities such as gunnery, bombing, and sonar training and maintenance. Of note, support craft would be more concentrated in the coastal waters in the areas of naval installations, ports, and ranges. Activities involving vessel movements occur intermittently and are variable in duration, ranging from a few hours up to weeks. More information on Navy and non-Navy vessel traffic patterns in the HSTT Study Area may be found in several studies prepared by the Navy (Starcovic and Mintz 2021; Mintz, 2016; Mintz and Filadelfo, 2011; Mintz, 2012; Mintz and Parker, 2006). Foreign Navies In addition, we note that in some cases, foreign militaries may participate in U.S. Navy training or testing activities in the HSTT Study Area. The Navy does not consider these foreign E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68294 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules military activities as part of the ‘‘specified activity’’ under the MMPA, and NMFS defers to the applicant to describe the scope of its request for an authorization. The participation of foreign navies varies from year to year, but overall is infrequent compared with Navy’s total training and testing activities. The most significant joint training event is the Rim of the Pacific (RIMPAC), a multinational training exercise held everyother-year primarily in the HRC. The participation level of foreign military vessels in U.S. Navy-led training or testing events within the HRC and within SOCAL differs greatly between RIMPAC and non-RIMPAC years. For example, in 2019 (a non-RIMPAC year), there were 0.1 foreign navy at-sea days (i.e., 1 day = 24 hours) within HRC and 20 foreign navy at-sea days within SOCAL (Navy 2021). Out of 56 U.S.-led training events in 2019, 4 involved foreign navy vessels, with an average time per event of 8.7 hours. In 2020, a RIMPAC year, foreign vessels participating in U.S. Navy-led events accounted for 32 at-sea days in the HRC from August through September (some of this activity occurred after the RIMPAC exercise). During RIMPAC 2022, foreign vessels operated and/or transited through the HRC for 576 hours (24 days). Even in a RIMPAC year, the days at sea for foreign militaries engaged in a Navy-led training or testing activity accounts for a very small percentage compared to the U.S. Navy activities. For instance, the 2020 foreign military participation (a RIMPAC-year) was 1.5 percent of the U.S. Navy’s average days at sea (32 days out of an estimated 2,056 days at sea). According to the U.S. Navy, consistent with customary international law, when a foreign military vessel participates in a U.S. Navy exercise within the U.S. territorial sea (i.e., 0 to 12 nmi (0 to 22.2 km) from shore), the U.S. Navy will request that the foreign vessel follow the U.S. Navy’s mitigation measures for that particular event. When a foreign military vessel participates in a U.S. Navy exercise beyond the U.S. territorial sea but within the U.S. Exclusive Economic Zone, the U.S. Navy will encourage the foreign vessel to follow the U.S. Navy’s mitigation measures for that particular event (Navy 2022a; Navy 2022b). In either scenario (i.e., both within and beyond the territorial sea), U.S. Navy personnel will provide the foreign vessels participating with a description of the mitigation measures to follow. If a foreign military is not participating in a U.S. Navy training or testing exercise, foreign military vessels operating within VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 the HSTT Study Area are expected to adhere to their own standard operating procedures and environmental mitigation measures. According to the U.S. Navy, the May 2021 vessel strike of two fin whales by an Australian navy vessel did not occur while that vessel was participating in a U.S. Navy-led training exercise. The Royal Australian Navy vessel was adhering to its standard operating procedures at the time of the strike. The Royal Australian Navy provided a report of the incident, which is discussed below to inform our analysis. NMFS analyzes the effects of these foreign military activities in two ways. First, effects of all past foreign military activities are captured in the baseline for the analysis, through marine mammal abundance estimates and population trends found in the SARs. Second, NMFS considers foreign military activities, including recent strikes, qualitatively in this proposed rule. For instance, in preparing this rulemaking, NMFS and the U.S. Navy discussed the nature, frequency, and control over joint or U.S. Navy-led training and testing activities with foreign entities to identify opportunities to encourage foreign militaries to adopt mitigation. NMFS and the U.S. Navy examined the Royal Australian Navy strike report for any lessons that could inform U.S. Navy strike mitigation. NMFS considered the Royal Australian Navy strikes along with other recent U.S. Navy strikes to determine whether these strikes indicate an increased risk of strike by the U.S. Navy in this region during the early summer months. NMFS also considered the species struck in this incident, fin whales, along with other literature, when considering the likelihood of certain species to be struck by the U.S. Navy. Finally, NMFS considered the fact that two fin whales were struck by the Royal Australian Navy qualitatively when considering other fin whale population and mortality trends, as well as the take proposed for authorization, as part of the negligible impact analysis. Standard Operating Procedures For training and testing to be effective, personnel must be able to safely use their sensors and weapon systems as they are intended to be used in a real-world situation and to their optimum capabilities. While standard operating procedures (SOPs) are designed for the safety of personnel and equipment and to ensure the success of training and testing activities, their implementation often yields additional benefits on environmental, socioeconomic, public health and PO 00000 Frm 00006 Fmt 4701 Sfmt 4702 safety, and cultural resources. Because standard operating procedures are essential to safety and mission success, the Navy considers them to be part of the proposed activities under NEPA and included them in the environmental analysis. We consider standard operating procedures as part of Navy’s specified activity for the purposes of MMPA but also, where procedures are utilized (even in part) to reduce impacts to marine mammal species and Navy’s commitment to follow the measures are practicable, certain SOPs may also be required as mitigation. Details on standard operating procedures were provided in the 2018 HSTT proposed rule; please see the 2018 HSTT proposed rule, the 2017 Navy application, and Chapter 2 (Description of Proposed Action and Alternatives) of the 2018 HSTT FEIS/OEIS for more information. As stated in its 2022 application, in 2018, the Navy updated its SOPs related to vessel safety to incorporate revised procedures regarding Lookouts for certain ship classes as per the 2021 Surface Ship Navigation Department Organization and Regulations Manual (NAVDORM). The 2021 NAVDORM requires the use of three Lookouts on Navy cruisers and destroyers as compared to the previous requirement of one Lookout when a vessel was underway and not engaged in sonar training or testing. However, as discussed in the Proposed Mitigation Measures section below, the Navy informed NMFS that requiring the additional Lookouts as mitigation is not practicable because this SOP may change in response to manning issues and national security needs. Further, since submission of its 2022 application, the Navy has updated its Lookout Training Handbook and implemented other training improvements, as described in the Proposed Mitigation Measures section (September 2022). Description of Marine Mammals and Their Habitat in the Area of the Specified Activities Marine mammal species and their associated stocks that have the potential to occur in the HSTT Study Area are presented in table 1 along with the best/ minimum abundance estimate and associated coefficient of variation value. Consistent with the 2018 HSTT final rule and 2020 HSTT final rule, the Navy anticipates the take of individuals from 38 marine mammal species by Level A harassment and Level B harassment incidental to training and testing activities from the use of sonar and other transducers, in-water detonations, E:\FR\FM\03OCP2.SGM 03OCP2 68295 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules air guns, and impact pile driving/ vibratory extraction activities. As described in detail later, serious injury or mortality of six species is also analyzed and proposed for authorization. In the 2018 HSTT proposed rule and 2018 HSTT final rule, we presented a detailed discussion of marine mammals and their occurrence in the HSTT Study Area, inclusive of important marine mammal habitat (e.g., ESA-designated critical habitat), biologically important areas (BIAs), national marine sanctuaries (NMSs), and unusual mortality events (UMEs). Please see these rules and the 2017 and 2019 Navy applications for additional information beyond what is provided herein. While there have been some minor changes described here, there have been no changes to important marine mammal habitat, NMSs, or ESA designated critical habitat since the issuance of the 2018 HSTT final rule that change our determination of which species or stocks have the potential to be affected by the Navy’s activities or the information in the Description of Marine Mammals and Their Habitat in the Area of the Specified Activities section in the 2019 HSTT proposed rule and 2020 HSTT final rule. Therefore, the information presented in those sections of the 2019 HSTT proposed rule and 2020 HSTT final rule remains current and valid with the exception of the information about UMEs, BIAs, and revised humpback whale stock structures, discussed below. On April 21, 2021, NMFS designated critical habitat for the endangered Western North Pacific Distinct Population Segment (DPS), the endangered Central America DPS, and the threatened Mexico DPS of humpback whales (86 FR 21082). Areas proposed as critical habitat include specific marine areas located off the coasts of California, Oregon, Washington, and Alaska. None of the designated critical habitat overlaps with the HSTT Study Area. One of the proposed areas, critical habitat Unit 19, would have overlapped with the SOCAL range in the HSTT Study Area but was excluded after consideration of potential national security and economic impacts of designation. NMFS, in the final rule designating critical habitat for humpback whales, identified prey species, primarily euphausiids and small pelagic schooling fishes of sufficient quality, abundance, and accessibility within humpback whale feeding areas to support feeding and population growth, as an essential habitat feature. NMFS, through a critical habitat review team (CHRT), also considered inclusion of migratory corridors and passage features, as well as sound and the soundscape, as essential habitat features. NMFS did not include either in the final critical habitat, however, as the CHRT concluded that the best available science did not allow for identification of any consistently used migratory corridors or definition of any physical, essential migratory or passage conditions for whales transiting between or within habitats of the three DPSs. The best available science also currently does not enable NMFS to identify particular sound levels or to describe a certain soundscape feature that is essential to the conservation of humpback whales. Regardless of whether critical habitat is designated for a particular area, NMFS has considered all applicable information regarding marine mammals and their habitat in the analysis supporting these proposed regulations. NMFS has reviewed the 2022 final Stock Assessment Reports (SARs; Carretta et al. 2023, Young et al. 2023). For all species except humpback whale, NMFS determined that neither the SARs nor any other new information changes our determination of which species or stocks have the potential to be affected by the Navy’s activities. For humpback whale, the 2022 final SARs include a revision to the humpback whale stock structure in the Pacific Ocean. In the 2020 HSTT final rule, NMFS authorized take of the CA/OR/WA stock and Central North Pacific stock of humpback whale. Given the revised stock structure, in this proposed rule, NMFS has reanalyzed the potential for take of each stock of humpback whale and determined that the Central America/ Southern Mexico-CA/OR/WA, Mainland Mexico—CA/OR/WA stock, and Hawaii stocks are likely to be taken by the Navy’s activities. Please refer to the 2022 Alaska and Pacific Ocean SARs for additional information about these new stocks.) The species considered but not carried forward for analysis are two American Samoa stocks of spinner dolphins—(1) the Kure and Midway stock and (2) the Pearl and Hermes stock. There is no potential for overlap with any stressors from Navy activities and therefore there would be no incidental takes, in which case, these stocks are not considered further. TABLE 1—MARINE MAMMAL OCCURRENCE WITHIN THE HSTT STUDY AREA Status Common name Scientific name Stock Occurrence MMPA Blue whale ..................... Bryde’s whale ................ Fin whale ....................... Balaenoptera musculus Eastern North Pacific ... Central North Pacific .... Strategic, Depleted ...... Balaenoptera brydei/ edeni. Eastern Tropical Pacific Balaenoptera physalus Hawaii .......................... CA/OR/WA ................... Hawaii .......................... ddrumheller on DSK120RN23PROD with PROPOSALS2 Humpback whale ........... Megaptera novaeangliae. Central America/Southern Mexico—CA/OR/ WA. Mainland Mexico—CA/ OR/WA. Hawai1i .......................... CA/OR/WA ................... Minke whale .................. Balaenoptera acutorostrata. Sei whale ....................... Balaenoptera borealis .. Hawaii .......................... Eastern North Pacific ... Hawaii .......................... VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 PO 00000 Frm 00007 Strategic, Depleted Endangered — ESA Endangered Hawaii — — Strategic, Depleted Strategic, Depleted Strategic Endangered 1 Strategic Threatened1 Endangered —1 — — — — Strategic, Depleted Strategic, Depleted Fmt 4701 — Endangered Sfmt 4702 — Endangered Endangered Southern California Summer Southern California Hawaii Southern California Hawaii Seasonal absence — 133 (1.09)/ 63. — — — Stock abundance (CV)/minimum population 1,898 (0.085)/1,767. unknown. 602 (0.22)/501. 11,065 (0.405)/7,970. Summer 203 (0.99)/101. Southern California Winter 1,496 (0.171)/1,284. Southern California Hawaii Southern California Hawaii Southern California Hawaii Winter 3,477 (0.101)/3,185. Summer — 11,278 (0.56)/7,265. 915 (0.792)/509. Summer — 438 (1.05)/212. 519 (0.40)/374. Summer 391 (0.9)/204. E:\FR\FM\03OCP2.SGM 03OCP2 68296 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules TABLE 1—MARINE MAMMAL OCCURRENCE WITHIN THE HSTT STUDY AREA—Continued Status Common name Scientific name Stock Occurrence MMPA Gray whale .................... Eschrichtius robustus ... Eastern North Pacific ... Western North Pacific .. Sperm whale ................. Physeter macrocephalus. CA/OR/WA ................... Hawaii .......................... — Strategic, Depleted Strategic, Depleted Strategic, Depleted — Endangered Endangered Endangered Pygmy sperm whale ...... Kogia breviceps ........... CA/OR/WA ................... Dwarf sperm whale ....... Kogia sima ................... Hawaii .......................... CA/OR/WA ................... — — — — Baird’s beaked whale .... Berardius bairdii ........... Hawaii .......................... CA/OR/WA ................... — — — — Blainville’s beaked whale. Cuvier’s beaked whale .. Mesoplodon densirostris. Ziphius cavirostris ........ Hawaii .......................... — — CA/OR/WA ................... — — Longman’s beaked whale. Mesoplodont beaked whales. Common Bottlenose dolphin. Indopacetus pacificus .. Hawaii .......................... Hawaii .......................... — — — — Mesoplodon spp ........... CA/OR/WA ................... — — Tursiops truncatus ....... California Coastal ......... — — CA/OR/WA Offshore .... — — False killer whale .......... Fraser’s dolphin ............. Killer whale .................... ddrumheller on DSK120RN23PROD with PROPOSALS2 — ESA Pseudorca crassidens .. Lagenodelphis hosei .... Orcinus orca ................. Long-beaked common dolphin. Melon-headed whale ..... Delphinus capensis ...... Northern right whale dolphin. Pacific white-sided dolphin. Pantropical spotted dolphin. Lissodelphis borealis .... Peponocephala electra — 5,707 (0.23)/4,486. Winter and Fall — — Southern California Hawaii Hawaii 4,111 (1.12)/1,924. 42,083 (0.64) 25,695. unknown. — — unknown. 1,363 (0.53)/894. — 1,132 (0.99)/564. — 5,454 (0.27)/4,214. — — 4,431 0.41/3,180. 2,550 (0.67)/1,527. — 3,044 (0.54)/1,967. — 453 (0.06)/346. 2,086 (0.35)/1,567. 477 (1.71)/178. — — — — — — 40,960 (0.7)/24,068. 300 (0.1)/276. — — — 349 (N/A)/349. Hawaii .......................... California ...................... — — — — — — 161 (1.06)/78. 83,379 (0.216)/69,636. Hawaiian Islands .......... Kohala Resident ........... CA/OR/WA ................... — — — — — — Hawaii Southern California Southern California Hawaii Southern California Hawaii Hawaii Southern California Southern California Hawaii — — — 40,647 (0.74)/23,301. unknown. 29,285 (0.72)/17,024. — 34,999 (0.222)/29,090. — unknown. Pygmy killer whale ........ Feresa attenuata .......... — — — — — — — — Risso’s dolphins ............ Grampus griseus .......... Hawaii .......................... CA/OR/WA ................... Hawaii .......................... — — — — — — Steno bredanensis ....... NSD 2 ........................... — — Delphinus delphis ........ Hawaii .......................... CA/OR/WA ................... — — — — CA/OR/WA ................... — — Hawaii .......................... Hawaii Pelagic ............. Hawaii Island ................ Oahu and 4-Islands ..... Kauai and Niihau ......... Kure and Midway ......... Pearl and Hermes ........ CA/OR/WA ................... — — — — — — — — — — — — — — — — Jkt 262001 — — — 4-Islands ....................... Hawaii Island ................ Hawaii Pelagic ............. Tropical ........................ 20:43 Oct 02, 2023 1,997 (0.57)/1,270. Hawaii Hawaii — VerDate Sep<11>2014 — — — — — — — — Endangered — Stenella coeruleoalba .. 290 (NA)/271. unknown. NA NA/97. NA. NA. unknown. 167 (0.14)/149. — — — — — Strategic, Depleted — — Oahu ............................ Striped dolphin .............. — — — — — — — Hawaii Pelagic ............. Kauai and Niihau ......... Oahu ............................ 4-Islands ....................... Hawaii Island ................ Main Hawaiian Islands Insular. Hawaii Pelagic ............. Northwestern Hawaiian Islands. Hawaii .......................... Eastern North Pacific Offshore. West Coast Transient .. — Stenella longirostris ...... 26,960 (0.05)/25,849. 3,477 (0.696)/2,048. — Spinner dolphin ............. Southern California Hawaii Southern California Hawaii Southern California Hawaii — — CA/OR/WA ................... Globicephala macrorhynchus. Southern California Southern California Southern California Hawaii Stock abundance (CV)/minimum population Southern California Southern California Southern California Hawaii Hawaii Hawaii Hawaii Hawaii Hawaii Lagenorhynchus obliquidens. Stenella attenuata ........ Rough-toothed dolphin .. Short-beaked common dolphin. Short-finned pilot whale Seasonal absence PO 00000 Frm 00008 Fmt 4701 Sfmt 4702 Hawaii Hawaii Hawaii Southern California Hawaii Southern California Hawaii Southern California Hawaii Southern California Southern California Hawaii Hawaii Hawaii Hawaii Hawaii Hawaii Hawaii Southern California E:\FR\FM\03OCP2.SGM — — — Winter & Spring — — — 03OCP2 unknown. unknown. 39,768 (0.51)/25,548. unknown. 10,328 (0.75)/5,885. 6,336 (0.32)/4,817. 7,385 (0.22)/6,150. — unknown. — — — 76,357 (0.41)/54,804. 1,056,308 (0.21)/ 888,971. 836 (0.79)/466. — — — — — — — — 12,607 (0.18)/10,847. unknown. 665 (0.09)/617. unknown. unknown. unknown. unknown. 29,988 (0.3)/23,448. 68297 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules TABLE 1—MARINE MAMMAL OCCURRENCE WITHIN THE HSTT STUDY AREA—Continued Status Common name Scientific name Stock Occurrence MMPA ESA Dall’s porpoise ............... Phocoenoides dalli ....... Hawaii .......................... CA/OR/WA ................... — — — — Harbor seal .................... Phoca vitulina .............. California ...................... — — Hawaiian monk seal ...... Hawaii .......................... Northern elephant seal .. Neomonachus schauinslandi. Mirounga angustirostris California sea lion ......... Zalophus californianus U.S. Stock .................... Guadalupe fur seal ........ Arctocephalus townsendi. Callorhinus ursinus ...... Mexico to California ..... Northern fur seal ........... California ...................... California ...................... Strategic, Depleted — — Endangered — — Strategic, Depleted Depleted Threatened — Seasonal absence Stock abundance (CV)/minimum population Hawaii Southern California Southern California Hawaii — — 35,179 (0.23)/29,058. 16,498 (0.61)/10,286. — 30,968 (NA)/27,348. — 1,465 3 (0.03)/1,431. Southern California Southern California Southern California Southern California — 187,386 (NA)/85,369. — 257,606 (NA)/233,515. — 34,187 (NA)/31,019. — 14,050 (NA)/7,524. Note: A ‘‘—’’ indicates that this column does not apply. 1 The Mainland Mexico-CA–OR–WA stock and the Mexico-North Pacific stock (which does not occur in the HSTT Study Area) of humpback whale comprise the Mexico DPS. The Hawai1i stock comprises the Hawai1i DPS. The Central America/Southern Mexico-CA–OR–WA stock comprises the Central America DPS. 2 NSD—No stock designation. Rough-toothed dolphin has a range known to include the waters off Southern California, but there is no recognized stock or data available for the U.S. West Coast. 3 The best official estimate of the total population size from the NMFS 2022 Stock Assessment Report (Carretta et al. 2023) is 1,465. This estimate is based on available data through 2020 data for Kure and Midway Atolls, Nihoa Island, and the MHI, and through 2019 for all other subpopulations. More recent survey data for 2021 and 2022 indicate an increasing trend in population size. NMFS estimates a total population size for 2022 of 1,605 (NOAA 2023). ddrumheller on DSK120RN23PROD with PROPOSALS2 Unusual Mortality Events An UME is defined under section 410(6) of the MMPA as a stranding that is unexpected, involves a significant die-off of any marine mammal population, and demands immediate response. From 1991 to the present, there have been 17 formally recognized UMEs affecting marine mammals in California and Hawaii and involving species under NMFS’ jurisdiction. There is one UME that is applicable to our evaluation of the Navy’s activities in the HSTT Study Area. The gray whale UME along the west coast of North America is active and involves ongoing investigations. At the time of publication of the 2020 HSTT final rule, there was an active UME for Guadalupe fur seal, which NMFS fully considered in its analysis (85 FR 41780, July 10, 2020). This UME was closed on September 2, 2021, and therefore, it is not discussed further beyond the information provided here. The UME was closed because conditions under which the UME was declared are no longer occurring or have become persistent. Scientists documented a reduction in strandings compared to peak UME years. The team of scientists who investigated this UME determined the cause of the UME as being due to malnutrition in Guadalupe fur seal pups and yearlings from ecological factors (e.g., warm water events) in the Pacific Ocean causing suboptimal prey conditions. Please see https:// www.fisheries.noaa.gov/national/ marine-life-distress/unusual-mortalityevent-2015-2021-guadalupe-fur-sealand-2015 for additional information on this UME. VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 Gray Whale UME Since January 1, 2019, elevated gray whale strandings have occurred along the west coast of North America, from Mexico to Canada. As of June 25, 2023, there have been a total of 674 strandings along the coasts of the U.S., Canada, and Mexico, with 333 of those strandings occurring along the U.S. coast. Of the strandings on the U.S. coast, 135 have occurred in Alaska, 83 in Washington, 22 in Oregon, and 93 in California. Full or partial necropsy examinations were conducted on a subset of the whales. Preliminary findings in several of the whales have shown evidence of emaciation. These findings are not consistent across all of the whales examined, so more research is needed. As part of the UME investigation process, NOAA has assembled an independent team of scientists to coordinate with the Working Group on Marine Mammal Unusual Mortality Events to review the data collected, sample stranded whales, consider possible causal-linkages between the mortality event and recent ocean and ecosystem perturbations, and determine the next steps for the investigation. Please refer to: https:// www.fisheries.noaa.gov/national/ marine-life-distress/2019-2023-graywhale-unusual-mortality-event-alongwest-coast-and for more information on this UME. See the Preliminary Analysis and Negligible Impact Determination section for additional information on how NMFS has considered this UME in this proposed rule. Biologically Important Areas Since publication of the 2020 HSTT final rule, Kratofil et al. (2023) PO 00000 Frm 00009 Fmt 4701 Sfmt 4702 identified updated BIAs in Hawaii. The HSTT Study Area overlaps the updated BIAs for small and resident populations of the following species in Hawaii: spinner dolphin, short-finned pilot whale, rough-toothed dolphin, pygmy killer whale, pantropical spotted dolphin, melon-headed whale, false killer whale, dwarf sperm whale, Cuvier’s beaked whale, common bottlenose dolphin, and Blainville’s beaked whale. Further, the HSTT Study Area overlaps updated BIAs for humpback whale reproduction in Hawaii. The updated BIAs overlap critical Navy training and testing areas within the HSTT Study Area, including most of the internal Navy operating areas. Please see Kratofil et al. (2023) for additional details about the BIAs. Potential Effects of Specified Activities on Marine Mammals and Their Habitat This section provides a discussion of the ways in which components of the specified activity may impact marine mammals and their habitat. The Estimated Take section later in this document includes a quantitative analysis of the number of individuals that are expected to be taken by this activity. The Negligible Impact Analysis and Determination section considers the content of this section, the Estimated Take section, and the Proposed Mitigation section, to draw conclusions regarding the likely impacts of these activities on the reproductive success or survivorship of individuals and whether those impacts are reasonably expected to, or reasonably likely to, adversely affect the species or stock through effects on annual rates of recruitment or E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68298 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules survival. In the Potential Effects of Specified Activities on Marine Mammals and Their Habitat section of the 2018 HSTT proposed and final rules, and as updated by the 2020 HSTT final rule, NMFS provided a description of the ways marine mammals may be affected by the same activities that the Navy will be conducting during the 7year period analyzed in this rulemaking in the form of serious injury or mortality, physical trauma, sensory impairment (permanent and temporary threshold shifts and acoustic masking), physiological responses (particularly stress responses), behavioral disturbance, or habitat effects. We do not repeat the information here, all of which remains current and applicable, and instead summarize any new relevant information from the scientific literature. For more information we refer the reader to those rules and the 2018 HSTT FEIS/OEIS (Chapter 3, Section 3.7 Marine Mammals), which NMFS participated in the development of via our cooperating agency status and adopted to meet our NEPA requirements. In the Potential Effects of Specified Activities on Marine Mammals and Their Habitat section of the 2018 HSTT final rule, we stated that it has been speculated for some time that beaked whales might have unusual sensitivities to sonar sound due to their likelihood of stranding in conjunction with midfrequency active sonar (MFAS) use, although few definitive causal relationships between MFAS use and strandings have been documented, and no such findings have been documented with Navy use in Hawaii and southern California. On March 25, 2022, a beaked whale (species unknown) stranded in Honaunau Bay, Hawaii. The animal was observed swimming into shore and over rocks. Bystanders intervened to turn the animal off of the rocks, and it swam back out of the Bay on its own. Locals reported hearing a siren or alarm type of sound underwater on the same day, and a Navy vessel was observed from shore on the following day. The Navy confirmed it used continuous active sonar (CAS) within 50 km (27 nmi) and 48 hours of the time of stranding, though the stranding has not been definitively linked to the Navy’s CAS use. An initial study of another deep diving odontocete, the sperm whale, found similar behavioral responses and reductions in foraging when whales were exposed to pulsed active sonar (PAS) and CAS at similar cumulative Sound Exposure Levels (SELcum), even though the CAS signal had a lower source level than the PAS signal. This VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 may indicate that animals were, in this case, responding to the cumulative energy of a signal rather than the instantaneous amplitude (Cure et al. 2021, Isojunno et al. 2020). If a beaked whale were inshore of a Navy vessel using either PAS or CAS MFAS, and responded by moving away from the vessel, they could find themselves in shallow water and become disoriented, as may have happened in the case of Honaunau Bay. In addition, the animal was not seen after it returned to sea, so blood tissue samples could not be obtained. There has been a growing body of literature about the impacts of new pathogens on the health and stranding of marine mammals, including beaked whales in Hawaii and other locations in the Pacific (e.g., Clifton et al. 2023 and West et al. 2013). New Pertinent Science Since Publication of the 2020 HSTT Final Rule NMFS has reviewed new relevant information from the scientific literature since publication of the 2020 HSTT final rule. Summaries of the new key scientific literature reviewed since publication of the 2020 HSTT final rule are presented below. The literature generally falls into the following topic areas: Vessel Strike; Aircraft Noise; Hearing, Vocalization, and Masking; Hearing Loss (Temporary Threshold Shift (TTS) and Permanent Threshold Shift (PTS)); Behavioral Reactions; Stranding; Population Consequences of Disturbance and Cumulative Stressors; Methodology for Assessing Acoustic Impacts. Vessel Strike Crum et al. (2019) analyzed a modeling framework using encounter theory to estimate the risk of lethal commercial vessel strike to North Atlantic right whales. Seasonal mortality rates of right whales decreased by 22 percent on average after a speed rule was implemented, indicating that the rule is effective at reducing lethal collisions. The rule’s effect on risk was greatest where right whales were abundant and vessel traffic was heavy but varied considerably across time and space. Keen et al. (2019) compared vessel traffic patterns in the Southern California Bight, San Francisco, and the Pacific Northwest and found fin whales had a higher risk of nighttime vessel strikes with the nighttime risk being double daytime risk. The authors concluded that the shipping lanes contained 14 percent of all traffic volume and contributed 13 percent of all strike risk similar to conclusions PO 00000 Frm 00010 Fmt 4701 Sfmt 4702 reached by Rockwood et al. (2017). However, the authors also point out that a California Current Ecosystem (CCE) wide shipping speed reductions would not be practicable. Instead, they proposed 24-hour speed restrictions around and within shipping lanes would be more effective and feasible than nighttime only speed restrictions elsewhere. Keen et al. (2019b) reported high fin whale habitat suitability throughout the Southern California Bight, in particular inshore in winter and in southern portions of the Bight, which include HSTT SOCAL Study Area. Leaper (2019) estimated that a global 10 percent reduction in shipping speeds could result in a reduction of underwater sound associated with shipping by approximately 40 percent and vessel strike risk by around 50 percent by 2050. The vessel strike risk reduction done by the author is highly variable based solely on the relationship between ship speed and risk, qualitative in its findings, and speculative. Redfern et al. (2019) compared risk of vessel strike to baleen whales around the Santa Barbara Channel based on 8 years of shipping data (2008–2015). Species evaluated include blue whales, fin whales, and humpback whales using available spatial habitat models and satellite tagging results. Spatial habitat modeling data included the years 1991, 1993, 1996, 2001, 2005, 2008, and 2009. The authors defined collision risk based on the co-occurrence of whales and ships for various management scenarios focused on adding shipping routes, expanding existing area to be avoided, and reducing shipping speed associated with these areas. Encounter rate theory was used to predict relative mortality resulting from vessel strikes by estimating (a) the encounter rate; (b) the number of encounters that result in a collision; and (c) the probability that a collision is lethal (Martin et al. 2016, Rockwood et al. 2017, Crum et al. 2019). The authors concluded that expanding the existing areas to be avoided and speed reductions within shipping lanes and their approaches would be the most effective solutions. Ship speeds declined in the Bight from 2008 to 2015 because California air pollution regulations and economic factors made slow-steaming strategies more favorable, therefore reduction in risk from slowing ships was greatest in 2008 and lowest in 2015. Rockwood and Jahncke (2019) estimated that humpback whale mortality from January to April in Southern California alone was 6.5 whales (1.63/month), based upon modeling using updated abundance E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules estimates for humpback whales off Southern California. When added to the estimated mortality from July to November, the total estimated annual humpback mortality from vessel strikes in California alone was 23.4 deaths (16.9 + 6.5). This study did not include information for January to April for fin or blue whales and did not estimate humpback mortality in central or Northern California. Thus, even this updated study may underestimate whale mortality. The author’s focus was exclusively on shipping approaches to San Francisco Bay (Northern California) and Los Angeles/Long Beach (Southern California) based on Rockwood et al. 2017 with new local fine scale analysis. The paper postulated potential mortality from models, not actual reported strikes. The model is used to predict whale mortality based on factors listed in Rockwood et al. 2017. In the model results, cargo vessels, especially container ships, accounted for more than half of the predicted mortality for all whale species in both Northern and Southern California with oil tankers accounting for the second highest mortality. The author’s recommendation concludes with commercial industrywide shipping speed reduction recommendations given the model is biased on mortality as a function of speed. In summary, Rockwood and Jahncke (2019) only addresses commercial shipping strike risk associated with major California commercial ports, and therefore, the paper may have limited applicability to how the Navy trains and tests in SOCAL. Se`be et al. (2019) assesses previous publications on whale vessel strike risk methodology and proposed a systematic approach to addressing the issue called the Formal Safety Assessment: (1) identification of hazards, (2) assessment of risks, (3) risk control options, (4) costbenefit assessment, and (5) recommendations for decision-making. The authors provided a case study based on data from Rockwood et al. (2017). No new data analysis is presented in the paper. Caveats to Se`be et al. (2019) are similar to those mentioned for Rockwood et al. (2017, 2019): older marine mammal data that may not be reflective of current or future distribution and focus on limited navigation within shipping approaches by commercial ships means that this study may have somewhat limited applicability to how the Navy trains and tests in SOCAL. Szesciorka et al. (2019) concluded that while whales have some cues to avoid ships, this is true only at close range, under certain oceanographic VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 conditions and if the whale is not otherwise distracted by feeding, breeding, or other behaviors. The paper is based on a single blue whale reaction observed in the Santa Barbara Channel, north of, and outside of, SOCAL. The blue whale was tagged as part of the U.S. Navy-funded Southern California Behavioral Response Study (SOCAL BRS) 2010–2015 and exposed to simulated MFAS when a closest point of approach of 93 m from a passing commercial container ship was noted. The whale was only tagged for a couple of hours before tag detachment. As other published papers report from the SOCAL BRS and as cited in the 2018 HSTT FEIS/OEIS, there can be significant individual variation in response to anthropogenic sources, which in this case would include vessel transit. Blondin et al. (2020) estimated blue whale vessel strike risk in the Southern California Bight by combining predicted daily whale distributions with continuous vessel movement data for 4 years (2011, 2013, 2015, 2017). The study focuses on the northern Southern California Bight associated with the commercial vessel traffic separation zone through Santa Barbara Channel approaching the Port of Los Angeles/ Long Beach. This area is north of and outside of SOCAL. The authors found that vessel traffic activity across years (2011, 2013, 2015, 2017) was variable and whale spatial probability was also variable based on inter-annual fluctuations in environmental conditions. Similar to previous monitoring efforts in Southern California, blue whales are typically in higher concentrations north of SOCAL from July-November (Mate et al. 2018), and Blondin et al. (2021) also picked up on this seasonal variability in their analysis. Oceanographic conditions favorable for krill development and concentration (i.e., cool water periods) would lead to increased blue whale occurrence and higher strike risk as evidenced during the higher number of blue whale strikes in 2007 (BermanKowalewski et al. 2010). Finally, the coarse level of data analyzed by the authors does not account for short-term patchy prey conditions influencing blue whale occurrence and may result in overestimation of average risk. Redfern et al. (2020) revised their 2019 assessments of vessel strike risk off California using interannual variability of risk across multiple years for blue whale, fin whale and humpback whale. The authors showed higher concentrations of both blue and fin whales along the Central California coast as compared to within SOCAL. PO 00000 Frm 00011 Fmt 4701 Sfmt 4702 68299 Magnitude of vessel strike risk was influenced by the ship traffic scenario. In addition, interannual species variability (1991, 1993, 1996, 2001, 2005, 2008, and 2009) also influenced the magnitude of vessel strike risk, but did not change whether nearshore or offshore scenarios had higher risk. The author’s conclusions were similar to Redfern et al. (2019). Figure 2 from Redfern et al. (2020) illustrates mean blue whale, fin whale, and humpback whale vessel strike risk for California based on data through 2009. Results from more recent NMFS surveys in 2014 and 2018 may or may not change this assessment in the future. Rockwood et al. (2020b) calculated expected blue whale and humpback whale mortality for hypothetical compliance scenarios by imposing speed caps within and adjacent to vessel traffic lanes leading to the Port of San Francisco in Central California, 400 miles (643.7 km) north of SOCAL. Rookwood et al. (2020a) had already demonstrated this area off Central California had concentrated krill prey with associated higher distributions of blue whales and humpback whales. Rookwood et al. (2020b) used better temporal resolution density data than previous modeling efforts reported by Rookwood et al. (2017). Biological data analysis for Rookwood et al. (2020b) was based on regional monthly krill and whale surveys from 2004–2017. Rockwood et al.’s (2020b) overall modeling conclusions were that lower commercial ship speeds within the vessel traffic lanes could potentially reduce whale mortality from vessel strike. The authors acknowledge that local changes in whale abundance can have strong effects on both inter-annual and long-term patterns of ship-strike mortality. Bernknopf et al. (2021) examined the socioeconomic benefits of using remotely-sensed information instead of in situ observations for determining blue whale occurrence in the eastern North Pacific Ocean. Their analysis used blue whale spatial distribution through 1991–2009 projects as representative of 2017 densities (Becker et al. 2012) combined with automatic identification system (AIS) derived measures of civilian commercial vessel traffic to predict blue whale vessel strike risk, called the Reference Case by the authors. The authors then compared estimated blue whale strike risk in a second analysis that, instead of using empirically measured blue whale observations converted into spatial habitat maps, used satellite tracking and environmental data to identify the spatial and temporal distribution of blue E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68300 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules whales, called the Counterfactual Case by the authors (Hazen et al. 2017). Estimated mean fatal strikes to blue whales for the Reference Case based on empirical density data from 1991–2009 ranged from 0.0490 to 2.5877 (max. values >1.000 between June to October) (see Table 2 in Bernknopf et al. 2021). Estimated mean fatal strikes to blue whales for the Counterfactual Case based on environmental estimates of blue whale density in 2017 ranged from 0.0286 to 2.1556 (max. values >1.000 between August to October). An important caveat to this research is that the two approaches result in different strike risks due to using different blue whale density estimates. Barkaszi et al. (2021) designed a model to estimate risks to large whales from shipping associated with offshore wind development along the U.S. Atlantic Coast. A key caveat for the model is that it is based on civilian vessel types associated with wind energy construction (e.g., tugs, service craft, etc.) with relatively fixed, direct routes to offshore wind sites. Therefore, while lower vessel speeds can reduce mortality, prediction and implementation of reduced speed zones are a far more complex challenge (Barkaszi et al. 2021). Vessel speed has less effect on strike risk over a fixed distance with fixed target density when there are no behavioral components considered (Yin et al. 2019). Vessel speed has a significant effect on strike risk only when behavioral components are considered, thus the ability for the user to input animal or vessel aversion is an important variable that can provide insights to the encounter risk based on vessel speeds. Cusato (2021) discusses the merits of vessel traffic separation changes or mandatory commercial ship speed reductions in the Santa Barbara Channel to reduce the risk of vessel strikes to large whales. The author compares it to similar restrictions on the U.S. East Coast for North Atlantic right whales. The paper is a policy discussion rather than an analysis of current biological distribution of large whales and associated risk. Cusato (2021) focuses on reducing risk from commercial ships in the current vessel traffic separation scheme within the Santa Barbara Channel. Speed restrictions in the Channel would need to be implemented through either Federal regulations or Federal statute. The author also correctly points out legitimate concerns that operating large vessels at slow speeds in certain conditions could pose a safety risk because large vessels are more difficult to control and steer at slower speeds. VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 Hausner et al. (2021) examined tradeoffs of blue whale vessel strikes and speed reduction mitigation over a 17-year period from 2002 to 2018 in the Southern California Bight under two management scenarios verses a ‘‘fixed strategy’’ that implements speed reductions for a fixed time period each year. The two management strategies were (1) a ‘‘daily strategy’’ implementing speed reductions in response to whale habitat conditions on a daily basis, and (2) a ‘‘seasonal strategy’’ implementing speed reductions in response to whale habitat conditions on a seasonal basis. The period of the author’s data analysis also covers the abnormal marine heat wave along the U.S. West Coast (2014–2016). The study’s focus was exclusively with the traffic separation lanes leading from the Santa Barbara Channel to the Ports of Los Angeles and Long Beach, a narrow corridor north of and outside of SOCAL. The daily and seasonal management strategies were more effective in reducing blue whale strike risk in the Santa Barbara channel than the fixed strategy. The daily management strategy had the highest protective effect. This apparent difference in strategies also applied during and after the 2014–2016 marine heat wave where the daily strategy added even extra protection. The authors acknowledged that interannual variation on blue whale presence in the shipping lanes added some variability to their analysis. In addition, their study only considered blue whales sighted within the Traffic Separation Scheme, as opposed to the broader region where vessels transit through or a blue whale could occur. Ransome et al. (2021) documented 40 vessel strikes to large whales in the Eastern Tropical Pacific Ocean between 1905 and 2017 off the coasts of 10 Central and South American countries (Mexico to Columbia). The authors concluded that vessel strikes to large whales are more prolific in this region than previously reported. For instance, the author’s findings of 40 vessel strikes was over three times greater than previous reporting and still is likely under reporting total whale strikes. The majority of whale strikes occurred from the 1950s onward with the growth of modern shipping and whale watching. Humpback whales were the most commonly struck species (45 percent) although 30 percent of the species were not identified in their data. Rockwood et al. (2021), similar to Rockwood et al. (2020b), calculated potential whale strike mortalities using AIS vessel data and whale density data to estimate mortality under several PO 00000 Frm 00012 Fmt 4701 Sfmt 4702 management scenarios within the commercial shipping lanes passing through Santa Barbara Channel and San Pedro Channel to and from the Ports of Los Angeles and Long Beach. While the Santa Barbara Channel is approximately 100 miles (160.9 km) north of SOCAL, Rockwood et al.’s study area also included the southern vessel traffic approach to Los Angeles and Long Beach which did extend into the northeast coastal portion of SOCAL. Recent whale surveys were not available for this effort, so the authors used longterm average blue, fin, and humpback whale densities from Becker et al. (2016). The author’s model also predicted a higher level of whale vessel strikes from commercial ships than Rockwood et al. (2017), although the authors acknowledged that for the 2020 publication they included more vessel classes than for the 2017 publication. Silber et al. (2021) examined the risk to gray whales from commercial shipping in the North Pacific. Vessel strike risk was highest for gray whales including the Western North Pacific Distinct Population Segment (WNP DPS) along most of the migratory routes. Highest risk to the WNP DPS of gray whales was outside of the SOCAL in the western Bering Sea, along the east coast of the Kamchatka peninsula (Russia), and coastlines of Japan. For both Eastern North Pacific and WNP DPSs of gray whales, the greatest vessel strike risk along the U.S. West Coast was from Washington to Central California. Helm et al. (2023) looked at strike risk to foraging humpback whales surfacing around large cruise ships transiting Glacier Bay National Park, Alaska. The authors concluded that the probability of foraging humpback whales remaining near the surface after first sightings was relatively high. While this puts humpback whales at increased risk of ship strike, it also allows shipboard observers more time to spot whales in order to maneuver the ship to avoid a strike. Lookout Effectiveness A recent study by Oedekoven and Thomas (2022) was designed to evaluate the effectiveness of Navy Lookouts at detecting marine mammals before they entered a defined set of mitigation zones (i.e., 200, 500, and 1,000 yd (182.9, 457.2, and 914.4 m)) during MFAS training activities. This study also compared Lookout effectiveness with that of trained marine mammal observers. Lookout teams were comprised of varying numbers of Lookouts depending on the type of ship and the training activity that was occurring (noting that the data was E:\FR\FM\03OCP2.SGM 03OCP2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules ddrumheller on DSK120RN23PROD with PROPOSALS2 collected prior to the Navy’s change in its SOPs to require the use of three Lookouts on Navy cruisers and destroyers.) Marine mammal observer teams consisted of two dedicated observers. Results of this study indicate that Navy Lookout Teams, which include Lookouts and other crew members, have approximately an 80 percent chance of failing to detect a pod of large baleen whales (rorquals) before they come closer than a mitigation range of 200 yd (182.9 m), compared with a 49 percent chance for trained marine mammal observers. The probability of a pod remaining undetected by Lookouts was greater for larger mitigation zones (i.e., 85 percent at 500 yd (457.2 m); 91 percent at 1,000 yd (914.4 m)). These values require some level of interpretation with regard to the numerical results. For instance, the study’s statistical model assumed that Navy ships moved in a straight line at a set speed for the duration of the field trials, and that animals could not move in a direction perpendicular to a ship. Violation of this model assumption would underestimate Lookout effectiveness for some data points. The values for both Navy Lookouts and the Marine Mammal Observers include animals under the water that would not have been available for detection by a Lookout. This study suggests that detection of marine mammals is less certain than previously assumed at certain distances. Hearing, Vocalization, and Masking Branstetter et al. (2021) measured underwater, masked hearing thresholds for frequencies between 0.5 and 80 kilohertz (kHz) in two killer whales. Critical ratios computed from the threshold measurements ranged from 16 to 32 decibels (dB). For communication signals in the 1.5–15 kHz range, killer whales would require the signal to be up to 26 dB above background Gaussian noise to be detected. The authors noted that ambient background noise in the marine environment is not Gaussian, the tones used in this study do not contain as much frequency information as biologically relevant signals, and the temporal and spectral characteristics of actual signals and noise may result in some degree of release from masking. These results are consistent with critical ratio measurements from other odontocete species, despite differences in hearing ability and head size. Fournet et al. (2021) measured call amplitudes from male bearded seals in the Beaufort Sea under different ambient noise conditions. The results showed that estimated source levels of seal calls increased with ambient noise VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 up to approximately 100–105 dB rootmean-squared (rms), above which no further Lombard effect was observed. This suggests that masking of bearded seal mating calls may occur, resulting in reduced communication range, which could reduce the ability of bearded seals to detect one another, mate, and reproduce. Mercado (2021) aimed to characterize how units within humpback whale songs were systematically varied using a large dataset of recordings from off the coast of Kona, Hawaii. The data showed that narrowband, reverberant units repeated at regular time intervals and dominated most song sessions, while broadband units were less predictable and occupied frequency bands that did not overlap with the narrowband units. The persistent production of narrowband units at regular time intervals resulted in consistent reverberation, which could either function to increase the range at which the song can be detected, or listen for fluctuations in echoes to indicate the presence of whale-sized targets. Rey-Baquero et al. (2021) collected theodolite and passive acoustic data on humpback whales in a pristine environment along the Colombian Pacific for 2 months. When acoustic data (n=34 files) were analyzed for unit duration and inter-unit interval before and after boats passed, song unit lengths were shorter and more variable when boats were present. The second aim of this study was to model the whales’ communication space during ambient noise or one to two boats traveling slowly. The most common peak frequency of this stock’s song (350 Hz) was used in the model, and, along with a whale’s location along the coast, informed calculations of transmission loss. However, the source level of ‘‘typical whale-watching boats’’ (145 dB re 1 uPa (decibels referenced to 1 micropascal) at 1 m; (Erbe et al. 2012)) and humpback whales (153 dB re 1 uPa at 1 m; (Au et al. 2006)) were taken from previous studies. Authors found that the infrequent addition of ecotour boat noise could temporarily reduce the ‘‘very audible area’’ (>10 dB SNR) in their song’s commonly used peak frequency (350 Hz) by 63 percent. Ruscher et al. (2021) measured aerial behavioral hearing thresholds in a Hawaiian monk seal (Neomonachus schauinslandi). The results showed a hearing range between 0.1 and 33 kHz with relatively poor sensitivity compared to Phocinae seals. The most sensitive thresholds were 40 dB re 20 mPa measured at 800 Hz and 3.2 kHz. The resulting audiogram was most similar to the northern elephant seal, PO 00000 Frm 00013 Fmt 4701 Sfmt 4702 68301 which is the only other species of Monachinae seal with audiogram data (Reichmuth et al. 2013). This study suggested that hearing sensitivity of Monachinae seals is substantially reduced compared to other species within their functional hearing group (phocid carnivores in air; PCA); therefore, the use of the PCA weighting function to predict auditory impacts is likely conservative for Hawaiian monk seals. Sills et al. (2021) measured underwater auditory detection thresholds in a male Hawaiian monk seal, and the range of most sensitive hearing was between 0.2 and 33 kHz. Peak hearing sensitivity of 73 dB re 1 mPa was observed at 1.6 kHz. The audiogram for this individual was similar but narrower and elevated compared to the hearing group (phocid carnivores in water; PCW) composite audiogram used to assess impacts to this species. Underwater vocalizations were also measured, and 6 call types were identified, which had peak energy between 55 and 400 Hz. The number of calls produced per minute fluctuated seasonally and peaked in the breeding season with the highest call rates recorded in December. Sweeney et al. (2022) examined the difference between noise impact analyses using unweighted broadband sound pressure levels (SPLs) and analyses using auditory weighting functions. The recordings used to conduct parallel analyses in three marine mammal species groups were from a shipping route in Canada. Since shipping noise was predominantly in the low-frequency spectrum, bowhead whales perceived similar weighted and unweighted SPLs while narwhals and ringed seals experienced lower SPLs when auditory weighting functions were used. The data provide a real-world example to support the use of weighting functions based on hearing sensitivity when estimating audibility and potential impact of vessel noise on marine mammals. A study by von Benda-Beckmann et al. (2021) modeled the effect of pulsed and continuous 1–2 kHz active sonar on sperm whale echolocation clicks and found that the presence of upper harmonics in the sonar signal increased masking of clicks produced in the search phase of foraging compared to buzz clicks produced during prey capture. Different levels of sonar caused intermittent to continuous masking (120 to 160 dB re 1 mPa2, respectively), but varied based on click level, whale orientation, and prey target strength. CAS resulted in a greater percentage of E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68302 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules time that echolocation clicks were masked compared to PAS. Kastelein et al. (2021c) compared the ability of harbor porpoises to detect signals in constant-amplitude noise with amplitude-modulated noise. Underwater, behavioral hearing thresholds were measured from harbor porpoises at 4 kHz under three conditions: ambient noise (control), sinusoidally amplitude modulated (SAM) masking noise, and Gaussian (constant amplitude) masking noise. Both masker types were centered at 4 kHz with a one-third octave bandwidth and were tested at various SPLs. The SAM noise was also tested at modulation rates from 1–90 hertz (Hz). The 4 kHz hearing test signals were 0.5, 1, and 2 seconds in duration. The results showed that, compared to Gaussian noise, up to 14.5 dB of masking release (from ‘‘dip listening’’) was observed in lower-modulation rate (1–5 Hz) SAM noise. The effect of masking on communication space is often modeled using constant-amplitude noise, whereas most Navy sources contain gaps, more like amplitudemodulated noise. This study suggests that the signal duration, masker level, and masker modulation rate and depth should be considered when modeling the effect of noise on signal detection. Isojunno et al. (2021) used data from 15 tagged sperm whales (Isojunno et al. 2020) to evaluate odontocete echolocation behavior as a function of received sonar exposures. Statistical analysis revealed small reductions in the number of buzzes and movement during sonar, but the most apparent change in echolocation behavior was a Lombard effect observed during higher sea states (increased surface noise). No behavioral changes in orientation relative to the sonar source were observed that would suggest an antimasking strategy for spatial release from masking. Theoretical modeling of masking potential in terms of detection range revealed that search phase clicks would likely be masked during both PAS and CAS, but the buzz clicks would not. For regular search phase clicks to be continuously masked, SELs would have to be equal to or greater than 160 and 173 dB re 1 mPa2s (dB referenced to 1 micropascal squared seconds) for PAS and CAS, respectively. Overall, the data showed more evidence for masking by increases in ambient noise (surface noise from higher sea states), than for sonar. This result could be due, in part, to the 1–2 kHz narrowband sonar masker, which is not comparable to broadband maskers such as ambient noise or shipping noise. VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 Matthews and Parks (2021) reviewed the existing literature on North Atlantic right whale acoustic behavior and summarize information on acoustic behavior of the Southern right whale, North Pacific right whale, and bowhead whale. The authors reviewed primary literature on whale vocalizations, anatomical modeling, and behavioral responses to playbacks to conclude that the North Atlantic right whale might have a hearing range of 20 Hz to 22 kHz. However, vocalization data cannot be used to directly estimate audible range since there are many examples of mammals (including marine mammals) that vocalize with energy below the frequency of best hearing, and calls can also contain high-frequency harmonics that are above the upper limit of hearing. The anatomical model developed by Ketten (1994) was used by Parks et al. (2007) to estimate a functional hearing range of 15 Hz to 18 kHz for this species. Jacobson et al. (2022) modeled the probability of Blainville’s beaked whale group vocal periods (GVPs) on the Pacific Missile Range Facility during periods of no naval activity, naval activity without hull-mounted MFAS, and naval activity with hull-mounted MFAS. Data were collected from bottom-mounted hydrophones on the range before, during, and after six Submarine Commanders Course (SCC) exercises. At an MFAS received level of 150 dB re 1 mPa rms (root mean square), the probability of GVP detection decreased by 77 percent (95 percent CI: 67 percent–84 percent) compared to periods when general training activity was ongoing and by 87 percent (95 percent CI: 81 percent–91 percent) compared to baseline conditions. This study found a greater reduction in p(GVP) with MFAS than observed in a prior study of Blainville’s beaked whales at the Atlantic Undersea Test and Evaluation Center (AUTEC) (Moretti et al. 2014). The authors suggest that this may be due to the baseline period in the AUTEC study including naval activity without MFAS, potentially lowering the baseline p(GVP), or due to differences in the residency of the populations at each range. Branstetter and Sills (2022) reviewed direct laboratory (i.e., psychoacoustic) studies of marine mammal hearing in noise. Psychoacoustic studies of auditory masking in marine mammals were described in detail and categorized by the type of signal and masker (e.g., tone in white noise), and specific conditions under which masking is reduced (i.e., release from masking). Specifically, comodulation masking release, or the reduction in masking due PO 00000 Frm 00014 Fmt 4701 Sfmt 4702 to amplitude or frequency modulation differences between the signal and noise, and spatial release from masking, or the reduction in masking due to spatial separation between signal and noise and the directional hearing ability of the listener, are discussed. Finally, energetic masking, or the ability of the listener to detect a signal was compared to informational masking, or the ability of the listener to comprehend the signal was reviewed. The authors point out that while the body of scientific evidence thus far shows that processes of the ear result in energetic masking, more research on informational masking is needed to develop realistic communication space models. This is because current communication space models are based on 50 percent signal detection rather than some threshold of successful signal recognition or interpretation by the listener. Hearing Loss (TTS and PTS) Houser (2021) reviews existing literature on the relationship between auditory threshold shift and tissue destruction in mammals. According to small terrestrial mammal literature, TTSs of approximately 30–50 dB measured 24 hours after sound exposure induced progressive tissue damage despite the return of normal hearing thresholds. Although large TTSs allow for full recovery of hearing, pathological tissue destruction may occur; however, smaller-magnitude TTSs are unlikely to result in tissue damage. The author concludes that the current criteria of 40 dB of TTS measured within minutes of the noise exposure as the onset of injury is likely to encompass recoverable auditory threshold shift without tissue damage. This publication supports the use of current definitions of auditory injury in marine mammals. Kastelein et al. (2022a) measured underwater behavioral hearing thresholds in two California sea lions at 0.6, 0.85, and 1.2 kHz before and after exposure to a one-sixth-octave noise band centered at 0.6 kHz for 60-minutes. Hearing tests were also conducted at 1, 1.4, and 2 kHz after exposure to a onesixth-octave noise band centered at 1 kHz for 60-minutes. For the 0.6 kHz exposure, the maximum TTS was 7.5 dB (6.7 dB mean) for a 210 dB cumulative SEL (SELcum) exposure at the hearing test frequency one-half octave above the center frequency of the fatiguing stimulus (0.85 kHz), which recovered after approximately 12 minutes. For the 1 kHz exposure, the maximum TTS was 10.6 dB (9.6 dB mean) after a 195 dB SELcum exposure at the hearing test frequency one-half octave above the center frequency of the fatiguing E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules stimulus (1.4 kHz). Mean threshold shift (TS) greater than 6 dB (mean = 8.0 dB, min = 7.2 dB, max = 8.5 dB) was also observed after exposure to the 1 kHz fatiguing stimulus at 195 dB SELcum for the 1 kHz hearing test frequency. For this exposure frequency, hearing recovered within 24 minutes. The results of this study show individuals exhibiting onset of TTS in water at lower received levels than the otariid thresholds in ‘‘Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)’’ (Navy, 2017). Kastelein et al. (2022b) measured underwater behavioral hearing thresholds in two California sea lions at 8, 11.3, and 16kHz before and after exposure to a one-sixth-octave noise band centered at 8 kHz for 60-minutes. Hearing tests were also conducted at 32 kHz after exposure to a one-sixth-octave noise band centered at 16 kHz for 60minutes. For the 8kHz exposure, the maximum TTS was 20.2 dB (18 dB mean) for a 190 dB SELcum exposure at the hearing test frequency one-half octave above the center frequency of the fatiguing stimulus (11.3 kHz), which recovered after approximately 12 minutes. For the 16 kHz exposure, the maximum TTS was 19.7 dB (16.3 dB mean) after a 207 dB SELcum exposure at the hearing test frequency one-half octave above the center frequency of the fatiguing stimulus (22.4 kHz). For these exposure frequencies and scenarios, hearing recovered within 72 minutes or less. The results of this study show TTS onset in-water occurred at lower received levels than what the current otariid criteria in ‘‘Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III’’) (Navy, 2017) suggest. Kastelein et al. (2021a) measured underwater behavioral hearing thresholds at 0.5, 0.71, and 1 kHz in one harbor porpoise before and after exposure to one-sixth-octave band noise centered at 0.5 kHz. Maximum TTS was 8.9 dB (mean = 7.6 dB) at the 0.5 kHz hearing test frequency after a 205-dB SELcum exposure. For the 0.71 and 1 kHz hearing test frequencies, no mean TTS > 6 dB was observed. However, at 0.71 kHz, maximum TTS was 6.5 dB (mean = 5.8 dB) was observed after a 205-dB SELcum exposure. At 1 kHz, a maximum of 6.3 dB of TTS (mean = 5.7 dB) occurred after 206-dB SELcum exposures. All shifts < 5 dB recovered within 12 minutes and shifts > 6 dB recovered within 60 minutes. These results are consistent with the criteria and thresholds described in ‘‘Criteria and Thresholds for U.S. Navy Acoustic and VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 Explosive Effects Analysis (Phase III)’’ (Navy, 2017). Kastelein et al. (2021b) measured behavioral, underwater hearing thresholds at 2, 2.8, and 4.2 kHz in two sea lions before and after exposure to band-limited noise centered at 2 kHz. Sea lion hearing was also tested at 4.2, 5.6, 8 kHz before and after exposure to noise centered at 4 kHz. Maximum TTS was 24.1 dB (22.4 dB mean) at the 5.6 kHz test frequency after a 205-dB SELcum exposure centered at 4 kHz. Threshold shifts greater than or equal to 6 dB occurred at 187, 181, and 187 dB SELcum for 4.2, 5.6, and 8 kHz test frequencies respectively. After exposure to the 2kHz noise, maximum TTS of 11.1 dB (10.5 dB mean) occurred for 203 dB SELcum at the 2 kHz test frequency. Threshold shifts greater than or equal to 6 dB occurred at SELcum of 192, 186, and 198 dB for test frequencies 2, 2.8, and 4.2 kHz respectively. These data suggest that one-half octave above the exposure frequency is the most sensitive to noise exposure. TTS between 6 and 10 dB recovered within 60 minutes, 10–15 dB of TTS recovered within 120 min, and TTS up to 24.1 dB recovered after 240 minutes. The results of this study show individuals exhibiting onset of TTS inwater at lower received levels than the current otariid criteria (‘‘Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)’’ (Navy, 2017)). Kastelein et al. (2020a) measured underwater, behavioral hearing thresholds in one harbor porpoise before and after exposure to playbacks of onesixth-octave band noise centered at 1.5 kHz and a 6.5 kHz continuous wave. Following exposure to the 1.5 kHz noise band at 201 dB SELcum, a maximum of a 7.8 dB, 9.8 dB, and 7 dB TTS was observed for 1.5, 2.1, and 3 kHz hearing frequencies respectively. After exposure to the 6.5 kHz continuous wave at 184 dB SELcum, a maximum of a 7.5, 16.7, and 11.8 dB TTS was observed for 6.5, 9.2, and 13 kHz hearing frequencies respectively. For the 6.5 kHz exposure, a mean TTS > 6 dB was observed for the 178 and 180 dB SELcum when the hearing test frequency was 9.2 kHz, and for the 180 dB SELcum when the hearing test frequency was 13 kHz. The results of this study show that the animal incurred onset of TTS at higher received levels than what the current HF cetacean criteria in ‘‘Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)’’ (Navy, 2017) indicate for both 1.5 and 6.5 kHz. Kastelein et al. (2020b) measured underwater, behavioral hearing thresholds in two harbor seals before PO 00000 Frm 00015 Fmt 4701 Sfmt 4702 68303 and after exposure to playbacks of onesixth-octave band noise centered at 0.5, 1, and 2 kHz. Hearing tests were conducted at the center frequency, onehalf octave above, and 1 octave above center frequency. No TTS > 6 dB was observed for any hearing frequency after 204, 210, or 211 dB SELcum exposures to the 0.5 kHz noise band. For the 1 kHz exposure frequency, max TTS of 7.4 dB (6.1 mean) was observed after a 207 dB SELcum exposure at a hearing frequency of 1.4 kHz. For this exposure frequency, no other test condition produced TTS > 6 dB; although, a 5.9 dB shift (at 1.4 kHz) occurred at 206 dB SELcum. For the 2 kHz noise band, after a 201 dB SELcum exposure, max TTS of 12 dB was measured one octave above the center frequency (4 kHz). For this exposure frequency, TTS > 6 dB was observed at SELcum > 201, 198, and 192 dB for hearing frequencies 2, 2.8, and 4 kHz respectively. All shifts recovered within 1 hour. These results of this study show that the animal incurred lower TTS (i.e., smaller threshold shifts) at higher received levels than what the current phocid pinniped criteria in ‘‘Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)’’ (Navy, 2017) indicate. Kastelein et al. (2020c) measured underwater, behavioral hearing thresholds in one harbor porpoise before and after exposure to playbacks of onesixth-octave band noise centered at 88.4 kHz. Maximum TTS of 13.6 dB was observed at 197 dB SELcum for the 100 kHz hearing test frequency. No TTS > 6 dB was observed for any SELcum at the 88.4 kHz test frequency. For 125 kHz, shifts > 6 dB were observed for 191, 194, and 197 dB SELcum exposures, with a mean TTS of 5.4, 6.1, and 5.9 dB, respectively. The results of this study show that the animal incurred TTS at higher received levels than what the current HF cetacean criteria in ‘‘Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)’’ (Navy, 2017) suggest. Kastelein et al. (2020d) measured underwater, behavioral hearing thresholds in one harbor porpoise before and after exposure to airgun impulses (‘‘shots’’). Exposure conditions varied with regard to number of airguns, number of shots, light cues, and position of the dolphin relative to the airguns. Hearing test frequencies were 2, 4, and 8 kHz, and no TTS > 6 dB was observed. The results of this study show that the animal would incur TTS onset at higher received levels than what the current HF cetacean criteria in ‘‘Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)’’ (Navy, 2017) suggest. E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68304 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules Kastelein et al. (2020e) measured underwater, behavioral hearing thresholds in two harbor seals before and after exposure to playbacks of onesixth-octave band noise centered at 40 kHz. For the 50 kHz hearing test frequency, a maximum TTS of 30.7 dB was observed 12–16 minutes after the 189 dB SELcum, and a mean TTS > 6 dB was observed for all SELcum 177 dB and above. The 30-dB shift recovered after 3 days. No TTS > 6 dB was observed for any SELcum at the 63 kHz test frequency for either seal. At 40 kHz, mean TTS of 9.2 dB was observed after a 189-dB SEL. The results of this study show that the animal incurred TTS at lower received levels than what the current phocid criteria in ‘‘Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)’’ (Navy, 2017) suggest. Sills et al. (2020) exposed one bearded seal to multiple impulsive underwater noise exposures (seismic air gun ‘‘shots’’). Hearing tests were conducted at 100 Hz and 400 Hz after exposures to 2, 4, and 10 shots. After a 4-shot (191 dB SELcum) exposure, max TTS of 9.4 dB was observed, but no other TTS > 6 dB was demonstrated, despite four 10-shot (194–195 dB SELcum) exposures. It is possible that TTS recovered during the measurements, as quantified by a mean ‘‘first miss’’ of 7.5 dB for the 10-shot exposures (mean TTS was 2.2 dB). The results of this study show that the animal incurred TTS onset at lower received levels than what the current criteria in ‘‘Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)’’ (Navy, 2017) suggest. Behavioral responses were also scored and averaged across three observers. For most exposures, the seal exhibited mild/detectable responses, and all scores indicated that the seal did not move more than half his body and consistently participated in the study. Tougaard et al. (2022) reviewed the most recent temporary TTS data from phocid seals and harbor porpoises and compared empirical data to the predictive exposure functions put forth by Southall et al. (2019), which were based on data collected prior to 2015. The authors concluded that more recent data supports the thresholds used for harbor porpoises (categorized as ‘very high frequency’, or VHF cetaceans), which over-estimated the hearing impact for sounds above 20 kHz in frequency. Similarly, the new data for phocid seals show TTS onset thresholds that are well-above the predicted levels for sounds below 5 kHz in frequency. However, phocid seals might be more VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 sensitive to higher frequency sound exposures than predicted, as the TTS onset data for frequencies higher than 20 kHz was below the predicted levels. von Benda-Beckmann et al. (2022) assessed whether correcting for kurtosis, a measure of sound impulsiveness, improved the ability to predict TTS in a marine mammal. Two different kurtosis correction factors were tested by applying them to frequency-weighted sound exposure levels (SELcum) and fitting (linear least squares) previously collected harbor porpoise TTS data to create dose-response functions, then comparing the resulting R2 values to that of the standard function used to fit TTS growth data. TTS data from both continuous and intermittent sound exposures were used. For intermittent and continuous 1–2 kHz exposures combined, kurtosis-corrected fits were poorer (R2 = 0.47, 0.68) than SELcumbased fits (R2 = 0.73). For intermittent exposures of different types, one of the kurtosis-corrections resulted in a better fit (R2 = 0.84) than SELcum (R2 = 0.64), but only when a model fitting parameter denoting the relationship between SELcum and risk of permanent hearing loss was specifically derived from harbor porpoise TTS growth data. The conclusions from this study were that the kurtosis-corrected SELs did not explain differences in TTS between intermittent and continuous sound exposures, likely because silent intervals provided an opportunity for hearing recovery that could not be accounted for by these models. Kurtosis might still be useful for evaluating sound exposure criteria for different types of sounds having various degrees of impulsiveness. Behavioral Reactions In a study by Benti et al. (2021), vocalizations from Northeast Atlantic herring-feeding killer whales and Northeast Pacific mammal-eating killer whales were played back to humpback whales in Norwegian waters while their behavior was monitored through animal-borne tags and visual observations. In five of six cases the humpback whales approached the fisheating killer whales, suggesting some attraction. The response to the mammaleating killer whales varied with the behavioral context of the humpback whales. The results suggested that the calls of the fish-eating killer whales may have acted like a dinner-bell and initiated approach and foraging behavior in the humpback whales, while the unfamiliar sounds of the mammal-eating killer whales may have been perceived as a threat in offshore waters, but led to mixed behavior PO 00000 Frm 00016 Fmt 4701 Sfmt 4702 during inshore herring foraging by humpback whales. These results indicated that the humpback whales were able to discriminate between the different call types and respond with different behavioral strategies. Boisseau et al. (2021) exposed foraging minke whales in Icelandic waters to an acoustic deterrent device that emitted 15 kHz pure tones with a source level of 198 dB rms. Pulse length and the number of pulses in a block were randomized but average pulse length was 752 millisecond (ms) with a 10 percent duty cycle. The source was deployed from a Zodiac boat 500 m away from an animal for the first two exposures, and 1000 m away in the remaining 8 exposures (max received level of 150 dB RMS at a minimum distance of 338 m). Video-range tracking was used to track animals before, during, and after the exposures and dive duration (sec), swim speed (km/h), reoxygenation rate (blows/min), and path predictability were also examined. During the exposure, animal speed and dive duration increased, measures of path predictability increased indicating straighter paths, and reoxygenation rate decreased. Path predictability had a strong relationship with received level whereas speed and dive duration did not, which suggested those two metrics were more influenced by the presence of the exposure signal than the received sound level. Cure´ et al. (2021) conducted controlled exposure experiments using both PAS (5 percent duty cycle) and CAS (95 percent duty cycle) to measure and score tagged sperm whale behavioral responses. No sonar control exposures resulted in significantly fewer and less severe behavioral responses than sonar exposures. No significant differences were observed between sonar types, but the presence of killer whales or pilot whales did significantly increase the number of responses. The probability of observing low and medium severity responses increased with cumulative sound exposure level (SEL, dB re 1 mPa2 s), reaching a probability of 0.5 at approximately 173 dB SEL for low severity responses. Medium severity responses reached a probability of approximately 0.35 at cumulative SELs between 179 and 189 dB. This study suggested that both PAS and CAS exposure resulted in a greater number of behavioral changes in sperm whales as compared to the vessel (control) alone, and the types of behavioral responses might differ across sonar types. Czapanskiy et al. (2021) modeled energetic costs associated with behavioral response to MFAS using E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules datasets from 11 cetaceans’ feeding rates, prey characteristics, avoidance behavior, and metabolic rates. Authors found that the short-term energetic cost was influenced more by lost foraging opportunities than increased locomotor effort during avoidance. Additionally, the model found that mysticetes incurred more energetic cost than odontocetes, even during mild behavioral responses to sonar. Durbach et al. (2021) analyzed acoustic tracks from minke whales detected on the Pacific Missile Range Facility (PMRF) in Hawaii in 3 years before, during, and after major Navy training exercises. These tracks were fit using a continuous-time correlated random walk at 5-minute interpolated locations. During sonar periods, fast movement became more northerly and more directed (less turning), with less movement south and east in the direction of the training activity, and this more northerly movement continued after sonar cessation. Specifically, whales to the north of the training activity were more likely to head north, while whales that were west of the activity were more likely to head west. Headings did not appear to change for slow, undirected movement during sonar. In addition, fast movement was more likely to occur during sonar than during any other period (70 percent during vs 35–41 percent in the other periods). Finally, whales were more likely to stop calling when in the fast state although not necessarily more during sonar than in other periods; in contrast, slow moving whales were more likely to stop calling during sonar than other periods. These results demonstrated that minke whales moved faster and movements were more directed during periods of active sonar. Minke whales also avoided the locations of the ships producing the sonar and were more likely to cease calling during sonar. Fernandez-Betelu et al. (2021) used passive acoustic data recorded over a 10-year time period to assess the effects of impulsive noise produced during offshore activities on coastal bottlenose dolphin occurrence. Offshore activities included seismic surveys and pile driving from wind farm construction. Echolocation detections of dolphins were compared across years with and without offshore activity and also across days with and without impulsive noise. The effect of distance from the noiseproducing activities on dolphin detections was also investigated by placing recorders (CPODs) at locations expected to be the most (impact areas) and least (reference areas) impacted by noise. No consistent relationship was VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 found between annual dolphin occurrence and impulsive noise, but significantly more detections were observed on days with impulsive noise. The results showed that dolphins were not displaced by impulsive noise levels up to 141 dB re 1 mPa and as close as 20 km (10.8 nmi) from the impact area. These results suggest that the increase in dolphin detections during far-field noise was likely due to an increase in the number and/or amplitude of echolocation vocalizations. Hastie et al. (2021) studied how the number and severity of avoidance events may be an outcome of marine mammal cognition and risk assessment. Five captive grey seals were given the option to forage in a high- or lowdensity prey patch while continuously exposed to silence, pile driving, or tidal turbine playbacks (source levels = 148 dB re 1 mPa at 1 m) for 1 hour. One prey patch was closer to the speaker, so had a higher received level in experimental exposures. Overall, seals avoided both anthropogenic noise playback conditions with higher received levels when the prey density was limited but would forage successfully and for as long as control conditions when the prey density was higher, demonstrating a classic cognitive approach utilized with predation risk and profit balancing. In a study by Holt et al. (2021a), DTAGs (miniature sound and movement recording tags) were attached with suction cups to Southern Resident Killer Whales in the Salish Sea to investigate the relationship between probability of prey capture and vessel and sound variables. The predicted probability of prey capture was lower when vessels increased their speed. Received noise level did not significantly affect the probability of prey capture. The rate of descent during dives was slower when echosounders were on. The observed effects of echosounders suggest that whales prolonged their foraging efforts to successfully hunt, which could be caused by acoustic masking or increased attention to vessels. The rate of descent increased with increasing broadband noise levels and decreasing vessel distance. Decrease prey abundance also decreased the probability of predicted prey capture. Holt et al. (2021b) attached DTAGs to 23 Southern Resident Killer Whales in the San Juan Islands over 3 field seasons in order to investigate the effects of vessel distance on underwater foraging behavior. When vessels were less than 366 m away, whales (n=13) decreased the number of dives associated with prey capture and the amount of time spent in these dives. Additionally, female killer whales were more likely to PO 00000 Frm 00017 Fmt 4701 Sfmt 4702 68305 stop foraging, socializing, and preysharing and instead start traveling when vessels approached at this distance. At the same distance from vessels, male orcas were more likely to transition from close prey capture to socializing and prey-sharing, but would not stop general foraging behavior, such as searching for prey at deeper depths. Female orcas may therefore be at greater risk than males during close vessel interactions. Kates Varghese et al. (2021) analyzed the effect of two separate surveys using a 12 kHz multibeam echosounder (i.e., downward directed, unlike ASW sonar) over the Southern California Antisubmarine Warfare Range (SOAR) hydrophone array on Cuvier’s beaked whale foraging. The authors conducted a spatial analysis, building off a temporal analysis of a previously presented dataset (Varghese et al. 2020). There were differences in spatial use of the SOAR for foraging between the 2 survey years. While no change in overall foraging effort was detected before, during, and after the surveys each year, some localized spatial shifts in foraging hot spots were detected during and after the survey in the second year. Because of the known heterogeneity of prey patches on SOAR, lack of evidence of avoidance of the sound source, and no observed change in overall foraging effort, the authors suggest that the observed spatial shifts were most likely due to prey dynamics. Ko¨nigson et al. (2021) tested the efficacy of Banana Pingers (300 ms, 59– 130 kHz frequency modulated, 133–139 dB rms re 1 mPa at 1 m source level) as a deterrent for harbor porpoise in Sweden. As described previously, these pingers were designed to avoid potential pinniped responses. Authors used recorded echolocation clicks with C– PODs to measure the presence or absence of porpoise in the area. Porpoise were less likely to be detected at 0 m and within 100 m of an active pinger, but a pinger at 400 m appeared to have no effect. In a study by Laborie et al. (2021), unmanned aerial vehicles (UAVs) were flown at three altitudes (25, 20, and 15 m) over Weddell seals, including adult males and females and females with pups. There was generally little response; 88 percent of the time the animals showed mild vigilance or no responses, and mothers rarely ended nursing. Agitation or escape responses only occurred in 12 percent of observations. The strongest response was in females with pups when wind speeds were lowest and therefore ambient noise levels were at their lowest. The probability of response E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68306 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules increased with lower altitude flights, so at altitudes over 25 m a low level of impact to Weddell seal behavior would be expected. Manzano-Roth et al. (2022) found that cross seamount beaked whales reduced clusters of foraging pulses (Group Vocal Periods) during Submarine Command Course events and remained low for a minimum of 3 days after the MFA sonar activity. An analysis subsequent to Varghese et al. (2020) suggested that the observed spatial shifts of Cuvier’s beaked whales during multibeam echosounder activity on the Southern California Antisubmarine Warfare Range were most likely due to prey dynamics (Kates Varghese et al. 2021). Ramesh et al. (2021) explored environmental drivers and the impact of shipping noise on fin whale vocalizations in Ireland. Approximately 3 months of passive acoustic fin whale call data from spring 2016 used in the habitat model found that fin whale calls increased at night, along with signs of higher prey availability. Fin whale calls were also less likely to be detected for every 1 dB re 1 mPa/minute increase in shipping noise levels (rms). However, these results should be used cautiously since the model was more likely to predict the absence of fin whale detections, rather than their presence. Santos-Carvallo et al. (2021) monitored fin whale behavior before, during, and after the presence of whale watching vessels in Caleta Chan˜aral de Aceituno to determine if the whale watching activity was having any adverse impacts on the fin whales. Whale watching activities were only conducted by local artisanal fishers; 39 boats have permission but less than 20 conduct the whale watching activity. Land-based observations were conducted in January and February of 2015–2018 via binocular scans and focal follow tracking using a theodolite. Groups of whales were tracked through the area with continuous sampling of position, behavior, and presence of boats for every surfacing until they were no longer visible. Behavior was classified as traveling or resting, and the groups’ swim speed, reorientation, and directness index, and these were modeled relative to the number of boats and whether the time period was before, during, or after the boats were present. Most observations occurred within the presence of at least one boat, but no more than three boats at one time. Travel swim speeds increased in the after period, while reorientation increased and directness decreased during and after the presence of boats. During rest behavior, reorientation VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 increased during the presence of boats compared to before the boats were present, and directness decreased during the presence of boats. These results indicate that when whale watching vessels were present, the fin whales changed their direction of movement more frequently, with less linear movement than occurred before the boats arrived; this behavior may represent evasion or avoidance of the boats. The increase in travel swim speeds after the boats left the area may be related to the vessel’s rapid speeds when leaving, sometimes in front of animals, leading to more avoidance behavior after the boats departed. Arranz et al. (2021) conducted a noise exposure experiment which compared behavioral reactions of resting shortfinned pilot whale mother-calf pairs during controlled approaches by a tour boat with two electric (136–140 dB) or petrol engines (139–150 dB). Approach speed (<4 kn (7.4 km per hour)), distance of passes (60 m (65.6 yd)), and vessel features other than engine noise remained the same between the two experimental conditions. Behavioral data was collected via unmanned aerial vehicle (UAV) and activity budgets were calculated from continuous focal follows. Mother pilot whales rested less, and calves nursed less, in response to both types of boat engines compared to control conditions (vessel >300 m (328 yd), stationary in neutral). However, they found no significant impact on whale behaviors when the boat approached with the quieter electric engine, while resting behavior decreased 29 percent and nursing decreased 81 percent when the louder petrol engine was installed in the same vessel. Hiley et al. (2021) exposed groups of harbor porpoises to ‘‘startle sounds’’, which were 200-ms in duration and were band limited (5.5–20.5 kHz) with a peak frequency of 10.5 kHz and a source level of 176 dB re 1 mPa. There were 13 exposure sequences in which the startle sound was repeated for 15 minutes at a 0.6 percent duty cycle, and 11 control sequences in which vessels operated but no startle sounds were played. Despite a larger distance between porpoise groups and vessels during sound exposure trials (152 m) as compared to control trials (90 m), avoidance responses during exposures were significant whereas no avoidance was observed for controls. Porpoises avoided the area where sound exposures took place for approximately 30–60 minutes, and no long-term exclusion effect was observed. Pellegrini et al. (2021) examined how boat presence impacts a unique PO 00000 Frm 00018 Fmt 4701 Sfmt 4702 subspecies of bottlenose dolphin (Tursiops truncatus gephyreus, Lahille’s bottlenose) that vocalizes while foraging cooperatively with local fishermen who cast nets onto dolphin-herded fish while standing in coastal waters in Brazil. Dolphin vocalizations changed in response to the number, type, and speed of boats within 250 m. When more than one boat was present, dolphins produced fewer whistles and had a lower click rate and a longer whistle duration; initial and maximum frequency increased as well, especially when group size or calf presence increased. Whistles were longer duration when boat speed increased as well. Martin et al. (2022) exposed a wild Cape fur seal breeding colony in Africa to playback recordings of boat noise and sea-side car traffic. Focal groups of at least six seals were approached by an experimenter who crawled within 6 m to avoid disturbing the seals. Seals were exposed to low (60–64 dB re 20 mPa rms SPL, broadcast at 6 m), medium (64–70 dB, broadcast at 3 m), or high (70–80 dB, broadcast at 1 m) levels, depending on the individual’s distance to the speaker. No behavioral differences were found between low, medium, and highlevel groups. Video recorded behavioral analysis demonstrated that mother-pup pairs spent less time nursing (15–31 percent) and more time awake (13–26 percent), vigilant (7–31 percent), and mobile (2–4 percent) during boat noise conditions compared to control conditions. Mothers were more vigilant (26 percent) than pups (7 percent) to medium levels of boat noise. Jones-Todd et al. (2021) analyzed the movement of seven Blainville’s beaked whales tagged at (AUTEC) relative to MFAS use during the SCC training event. Data from these tags was previously reported by Joyce et al. (2019). A continuous time correlated random walk movement model accounted for location accuracy by modeling 100 track imputations for each tag and arranged samples in equal time intervals. The probability of whale presence within the boundary of the instrumented range (on range), and outside the boundary of the instrumented range (off range) was modeled relative to the time since the last MFAS transmission. Results show there was a higher probability that whales on the range would go off range when there were MFAS transmissions, and that whales off the range would stay off the range when there were MFAS transmissions. These results indicate a response to MFAS that lasted for 3 days since transition rates on-off and off-on the range returned to baseline levels E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules after that amount of time. There was also variability in transition rates and time spent on/off range between individuals, which highlights the need to analyze a larger sample size of whales. Durban et al. (2022) tested new methods of observing behavioral responses of groups of small delphinids to sonar, where the use of tags is challenging, and the response of the group is more salient than that of the individual. They tested the use of a land-based observation platform coupled with a drone and multiple acoustic recorders to observe the vocal behavior, group cohesion, group size, and group behavior before, during, and after a simulated sonar exposure. In a group of short-beaked common dolphins, the authors found the number of whistles and sub-groups to increase during the exposure period, but the directivity of the tracked subgroup did not change much. Ko¨nigson et al. (2022) tested the efficacy of Banana Pingers (300 ms, 59– 130 kHz frequency modulated, 133–139 dBrms re 1 mPa at 1 m source level) as a deterrent for harbor porpoise in Sweden. As described previously, these pingers were designed to avoid potential pinniped responses. Authors used recorded echolocation clicks with C– PODs to measure the presence or absence of porpoise in the area. Porpoise were less likely to be detected at 0 m and within 100 m of an active pinger, but a pinger 400 m appeared to have no effect. Miller et al. (2022) investigated the risk disturbance hypothesis that an animal’s response decision is a trade-off between perceived risk and the cost of a missed opportunity (the reward of foraging). The authors predicted that species that are more vulnerable to predation would be more likely to respond to both predator sounds and anthropogenic stressors. Using data collected from 2008 to 2017 during the 3S project in Norway, changes in foraging duration during killer whale playbacks and changes in foraging duration during mid-frequency sonar were positively correlated across the four species examined (listed in order of increasing sensitivity to foraging disruption: sperm whales, long-finned pilot whales, humpback whales, and northern bottlenose whales). This suggests that tolerance of predation risk may play a role in sensitivity to sonar disturbance. Paitach et al. (2022) tested the efficacy of Banana Pingers (300 ms, 50–120 kHz frequency modulated, 145 dB +/¥ 3 dB at 1 m source level) as a deterrent and entanglement mitigation for Franciscana VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 dolphins in Brazil. These pingers were designed to emit sound outside of the best hearing range for pinnipeds and were therefore less likely to incite a ‘‘dinner bell’’ effect. Authors used recorded echolocation clicks with C– PODs to measure the presence or absence of dolphins in the area. Dolphins were 19 percent and 15 percent less likely to be detected nearby and within 100 m of an active pinger respectively, but dolphins 400 m from the pinger did not appear to avoid it. While a reduction in vocalizations does not always equate to a reduction in presence, this species has been previously seen departing from areas with active pingers. Authors did not witness any habituation to the pinger during the length of the experiment (64 days), and although they recorded fewer dolphins in the area over time, they believe this was due to seasonality rather than habitat displacement. Siegal et al. (2022) used Dtag data from 15 northern bottlenose whales tagged during 3S efforts off Norway (2013–2016) to estimate body density (to represent body condition by lipid energy stores) using hydrodynamic models and obtain foraging and antipredator indicators based on vocal behavior and dive metrics. The authors compared relative anti-predator/foraging indices to body condition and found that relative anti-predator to foraging indices typically did not depend on body condition. This finding is inconsistent with the needs/assets hypothesis; an individual in poor condition would accept more risk (i.e., engage in less anti-predator behavior) for foraging opportunities, whereas healthy animals can afford to be more risk averse (i.e., have a relatively higher anti-predator to foraging index ratio). The authors suggest that this result may be due to an insufficient range of body conditions in the data set to determine a relationship, or a selection of bolder individuals in the tagging effort. The authors also suggest that animals in good condition may take greater predation risks because they may successfully flee. Three of the 15 whales were exposed to sonar (presented in prior 3S publications). The authors compared foraging and anti-predator metrics pre- and post-exposure, showing that all three animals increased their anti-predator index and reduced their foraging index. Stanistreet et al. (2022) used passive acoustic recordings during a multinational navy activity to assess marine mammal acoustic presence and behavioral response to especially long bouts of sonar lasting up to 13 consecutive hours, occurring repeatedly PO 00000 Frm 00019 Fmt 4701 Sfmt 4702 68307 over 8 days (median and maximum SPL = 120 dB and 164 dB). Cuvier’s beaked whales and sperm whales substantially reduced how often they produced clicks during sonar, indicating a decrease or cessation in foraging behavior. Few previous studies have shown sustained changes in foraging or displacement of sperm whales, but there was an absence of sperm whale clicks for 6 consecutive days of sonar activity. Sperm whales returned to baseline levels of clicks within days after the activity, but beaked whale detection rates remained low even 7 days after the exercise. In addition, there were no detections from a Mesoplodon beaked whale species within the area during and at least 7 days after the sonar activity. Clicks from northern bottlenose whales and Sowerby’s beaked whales were also detected but were not frequent enough at the recording site used to compare clicks between baseline and sonar conditions. Benhemma-Le Gall et al. (2021) compared harbor porpoise presence and foraging activity between periods of baseline and construction at two Scottish offshore windfarms with arrays of echolocation click detectors (C– PODs). Noise levels were measured with calibrated noise recorders, and vessel presence was tracked with AIS data. Authors found an 8–17 percent decline in porpoise presence compared to baseline, with more porpoises (more buzzing) further from vessels, construction sites, and related higher levels of noise. The probability of porpoise occurrence by source vessels decreased by 9–23 percent without piling activity, and by 40–54 percent during pile driving. Porpoises were displaced up to 12 km (6.5 nmi) from pile driving and 4 km (2.2 nmi) from construction vessels. At an average vessel distance of 2 km (1.1 nmi), porpoise occurrence decreased by up to 35 percent. Outside piling hours, porpoise detection decreased by 17 percent (0.26), and foraging (buzzes) decreased by up to 41.5 percent (0.03) with increasing noise levels (159 and 155 dB re 1 mPa, respectively). During piling activities, porpoise occurrence began lower (0.16, 102 dB) but occurrence still decreased by 9 percent (0.07), and foraging (buzzes, beginning at 0.76, 104 dB) also decreased by 61.8 percent (0.15) with increasing noise levels (161 and 155 dB re 1 mPa, respectively). Kastelein et al. (2022c) recorded pile driving sounds 100 m from construction for an offshore windfarm turbine, and six versions of the sound were created with varying frequency content using low-pass filters at 44.1, 6.3, 3.2, 1.5, 1.0, E:\FR\FM\03OCP2.SGM 03OCP2 68308 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules ddrumheller on DSK120RN23PROD with PROPOSALS2 and 0.5 kHz, at levels of 135 dB re 1 mPa2s. When authors played these impulsive sounds back to a single harbor porpoise in a pool, she increased swim speed, respiration rate, distance from the transducer, and occasionally jumped in response to the sounds with higher frequencies present (i.e., the sounds with a wider bandwidth, especially sounds low-pass filtered at 44.1 and 6.3 kHz). However, the porpoise still moved away from the three most narrowband sounds, just not as far. Results indicate that frequency weighting of SEL may improve prediction of harbor porpoise behavioral responses, and authors present the argument that weighted SELs should be used for reporting behavioral response threshold levels for criteria. Todd et al. (2022) detected harbor porpoises with C–PODS before, during, and after pile driving for an oil and gas platform from 2015–2020. Pile driving single strike SEL at 750 m was 160–164 dB re 1 mPa2s. Porpoise detections significantly decreased at the beginning of the construction project, but detections appeared to return to baseline levels within 5 months. According to the authors, the lack of significant trend over years indicated that porpoises returned to the area and did not experience habitat displacement for the entire 5-year period. Physiological Responses and Stress Elmegaard et al. (2021) exposed two captive harbor porpoises to sonar sweeps (6–9 kHz, 500 msec duration, 50–100 msec rise time, varying received levels (RL)) and pulsed sounds (50 msec duration, peak frequency 40 kHz, half power bandwidth of ∼5 kHz, rise time < 5 msec, varying RL) to investigate startle reflex and changes in heart rate. The sonar exposures did not elicit startle responses; the initial two to three exposures induced bradycardia (a slow heart rate), with subsequent habituation. This habituation was conserved after a 3-year pause in exposures. The authors suggest that the initial bradycardia allows ‘‘a prolonged breath-hold to assess the nature of a novel stimuli or flee in crypsis if needed;’’ in naı¨ve wild cetaceans, the reduced peripheral perfusion caused by this response may reduce N2 diffusion from supersaturated tissues during dive ascents, increasing risk of decompression sickness. Startle responses to the pulse exposures were directly correlated to RL. The 50 percent motor-startle probability threshold was around 130 dB re 1 mPa (rms50). This is ∼85 dB above hearing threshold and is similar to that observed in bottlenose dolphins (∼90 dB over hearing threshold) (Gotz et al. 2020). No VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 significant change in heart rate was observed. The authors suggest that the parasympathetic cardiac dive response may override any transient sympathetic response, or that diving mammals may not have the cardiac startle response seen in terrestrial mammals in order to maintain volitional cardiovascular control at depth. Fahlman et al. (2021) reviews decompression theory and the mechanisms dolphins have evolved to prevent high N2 levels and gas emboli (i.e., bends-like symptoms) in normal conditions. However, in times of high stress, the selective gas exchange hypothesis states that this mechanism can break down. In addition, circulating microparticles may be useful biomarkers for decompression stress in cetaceans. Yang et al. (2021) measured cortisol concentrations in blood samples of two captive bottlenose dolphins and found significantly higher levels after exposure to high sound level (140 dB re 1 mPa) impulsive noise playbacks, compared to control and low sound levels (0 and 120 dB re 1 mPa, respectively). Six cytokine gene transcriptions were also measured in blood samples and two (IL–10 and IFN-g) showed significant changes at high sound level exposure, compared to control and low sound levels. Results suggest that repeated exposures or sustained stress response to impulsive sounds may increase an affected individual’s susceptibility to pathogens, affect growth and reproduction, etc. In addition, no avoidance behavior was observed during the trials, indicating that stress-induced physiological changes could be present despite the absence of behavioral changes. Williams et al. (2022) measured physiological and behavioral responses in narwhals in the Arctic during seismic airgun impulse exposure compared to control conditions. Responses were measured using heart rateaccelerometer-depth recorders and changes in locomotor, cardiovascular, and respiratory responses were observed following exposure. Airgun SELs, as received at 10 m depth during sound source verifications, were approximately 152 dB re 1 mPa2s at 1 km (0.5 nmi) range and decreased to approximately 120 dB re 1 mPa2s at 10 km (5.4 nmi) dives. The response to seismic and vessel noise was a reduction in gliding descents and prolonged periods of high intensity activity associated with periods of elevated stroke frequencies. Noise exposure also resulted in periods of prolonged and intense bradycardia (i.e., slowed heart rate). An increase in postdive respiratory rates occurred during PO 00000 Frm 00020 Fmt 4701 Sfmt 4702 recovery from noise-exposed dives compared to control dives. Stranding Danil et al. (2021) document the findings of NOAA’s investigation of the strandings of three coastal bottlenose dolphins in 2015 at Silver Strand Training Complex in NOAA Technical Memorandum NMFS–SWFSC–641. On October 21, 2015, two dolphins were found stranded dead near each other on the beach. Because a Navy major training exercise (MTE) was underway, these strandings met the criteria of an Uncommon Stranding Event in accordance with the Southern California Stranding Response Plan in the Navy’s Phase 2 LOA for HSTT. A third decomposed dolphin was found in the same area 10 days later. Examination of the dolphins resulted in findings indicative of severe acute trauma, including lower jaw subcutaneous hemorrhage, emphysema, and cervical blubber hemorrhage. Additional signs of injury to the cerebrum and heart, or lipids in the lungs were also discovered. No hemorrhage was found near the ears. At least two of the dolphins showed signs of feeding before stranding, and all were in robust condition. There were no external signs of strike or entanglement. These observations and lack of others did not clearly determine the cause of the acute trauma. Based on previous case studies, the investigators determined that underwater detonation, peracute underwater entrapment (i.e., fisheries interaction), or sonar were the most plausible causes. The Navy notes that sonar has not been associated with these kinds of symptoms before, nor has there ever been any association between dolphin mortality and sonar. No antisubmarine (ASW) sonar or explosive use was associated with the Navy MTE; however, unit level training with MF1 sonar occurred on October 19 (for 35 minutes) and October 20 (62 minutes in total), with sonar use as close as 6 nmi (11.1 km) to the stranding location. No known squid or bait fishing efforts within U.S. waters occurred in the vicinity preceding the strandings. The Navy notes that it is unknown what fishing efforts occurred in Mexican territorial waters immediately south of the stranding location. Wang et al. (2021) conducted an auditory-evoked potential (AEP) hearing test on a single stranded 19-year-old male melon-headed whale in the 9.5— 181 kHz frequency range. Tone pip trains were presented underwater at a depth of 0.3 m and 1 m distance from the whale, and AEPs were recorded by suction cup electrodes on the skin surface. Hearing was measured in this E:\FR\FM\03OCP2.SGM 03OCP2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules ddrumheller on DSK120RN23PROD with PROPOSALS2 individual after it had been stranded and during attempted rehabilitation in a concrete pool. Eighteen frequencies were measured once, and eight frequencies were measured twice, yielding an audiogram that showed elevated hearing thresholds (compared to the pygmy killer whale) between 10 and 100 kHz. There are no data from normal-hearing individuals of the melon-headed whale species to which this study’s data can be compared. Population Consequences of Disturbance and Cumulative Stressors Southall et al. (2021) provided updated guidance and methods to assess the severity of behavioral responses by marine mammals to several types of anthropogenic noise sources. The criteria developed in the 2007 effort were updated by explicitly distinguishing between captive and field studies, decoupling their respective severity scales, and splitting the severity scale into three categories of foraging, survival, and reproduction. In addition, the updated guidance changed the categorization of noise sources and began to consider long term consequences of exposures rather than just immediate responses. Additional and consistent metrics to be reported in behavioral response studies are recommended, including subjectspecific metrics (e.g., functional hearing group, age class, sex, behavioral state, presence of calf), exposure context metrics (e.g., exposure type, range to source, source and animal depth, presence of other species or other noise sources), and noise exposure metrics (e.g. exposure duration, rise time, number of exposures, SPL [rms and pp], SEL, SNR). The authors then applied the severity scale to acute exposure studies using sonar sources, continuous (industrial) sources, pile driving sources, and airgun sources. For the long-term exposure analysis, a set of factors developed by Bejder and Samuels (2003) were applied to longterm studies on whale-watching and other long-term exposure or multiexposure datasets. These factors included metrics of short-term impacts and long-term survival measures, characteristics of the studies, and sources of anthropogenic disturbance. The applied examples of scoring both acute and long-term studies of behavioral response provide a framework for other researchers to apply the same metrics to their own studies. Migrating humpback whale mothercalf pairs’ responses to seismic surveys were modeled by Dunlop et al. (2021) using both a forwards and backward approach. While a typical forwards VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 approach can determine if a stressor would have population-level consequences, authors demonstrated that working backwards through a population consequences of disturbance (PCoD) model can be used to assess the ‘‘worst case’’ scenario for an interaction of a target species and stressor. Assumptions for the extreme scenario were likely exaggerated (e.g., in area for > 48 hours, exposed to > 3 air gun events) but lack data to inform humpback nursing behavior and calf survivability during acoustic stressors. The results demonstrated that migrating whales would not likely experience enough of a delay as a result of disturbance to result in population consequences, but whales disturbed in breeding or resting areas would be more vulnerable to consequences of disturbance. Greenfield et al. (2020) demonstrated that bottlenose dolphins who had been injured from boat strike or entanglement experienced a decline in their social network’s preferred associations, and as a result were more vulnerable to predation and less fecund. Hin et al. (2021) used a previously published energy budget model for pilot whales (Hin et al. 2019) to examine how lost foraging days affect individuals in a population at carrying capacity. In this model, depletion of prey is dependent on whale density, and prey density limits the energy available for growth, reproduction, and survival. The authors assumed extreme disturbance events for this study: consecutive days of no foraging affecting all individuals in a population. The undisturbed whale population was regulated through the effect of prey availability on calf survival and pregnancy rates and on age at first reproduction of females. During a disturbance event, population decline was generally attributed to loss of lactating females and calves due to reduced body condition. The subsequent increase in prey density and per capita prey availability, however, resulted in improved body condition in the population overall and decreased age at first calf. As disturbance duration was increased (∼40 days of no foraging), the population would enter extreme decline towards extinction. Murray et al. (2021) conducted a cumulative effects assessment on Northern and Southern Resident killer whales, which involved both a Pathways of Effects conceptual model and a Population Viability Analysis quantitative simulation model. Authors found that both populations were highly sensitive to prey abundance and were also impacted by the interaction of low prey abundance with vessel strike, PO 00000 Frm 00021 Fmt 4701 Sfmt 4702 68309 vessel noise, and polychlorinated biphenyls contaminants. However, more research is needed to validate the mechanisms of vessel disturbance and environmental contaminants. Pirotta et al. (2020) reformulated their previous dynamic energy budget model (Pirotta et al. 2018) to investigate the state-dependent life history strategies of female long-finned pilot whales and trade-offs between their body condition (i.e., ability to offset starvation during pregnancy and provide milk), prey availability, and decision to reproduce in situations with and without disturbance. Many whales in this model attempted to reproduce young, and while that had no cost in situations without disturbance, young mothers would starve and die when foraging was prevented by some disturbance event or because resources were low (winter). Whale reproductive strategies resulted in lower lifetime reproductive output, compared to the model used in Hin et al. (2019). Pirotta et al. (2021) integrated different sources of data (e.g., controlled exposure data, activity monitoring, telemetry tracking, and prey sampling) into a bioenergetic model, which was used to predict effects from sonar on a blue whale’s daily energy intake. Approximately half of the simulated whales had no change in daily net energy intake because they either had no response or were not exposed. However, the other half experienced a decrease in net energy intake. A portion (11 percent) of those simulated whales had negative net energy even after brief (e.g., 6–30 min) or weak (e.g., 160–180 dB re 1 mPa source level) events, which indicated that they would not be able to cover that day’s energetic cost. This dichotomy in results was due to the variation in activity budgets, lunging rates and ranging patterns between tagged whales. This evidence suggests that context can influence the predicted costs of disturbance even more than body size or prey density distribution on a daily scale (although prey availability and abundance affected behavioral patterns). Pirotta et al. (2022) evaluated potential long-term effects of changing environmental conditions and military sonar by modeling vital rates of Eastern North Pacific blue whales. Previous work from Pirotta et al. (2021) was used as a foundation for incorporating the most recent best available science into the vital rate model presented in this study. Using data and underlying models of behavioral patterns, energy budgets, body condition, contextual responses to noise, and prey resources, the model predicted female vital rates E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68310 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules including survival (age at death), and reproductive success (number of female calves). The model simulation results showed that ‘‘[e]nvironmental changes were predicted to severely affect vital rates, while the current regime of sonar activities was not.’’ The case study used an annual sonar regime in SOCAL based on the description of the action in the Navy’s 2018 HSTT FEIS/OEIS. Additional military sonar scenarios were modeled, and a ten-fold increase in sonar activity combined with a shift in geographical location to overlap with main feeding areas of blue whales resulted in a moderate decrease in lifetime reproductive success (Cohen’s d = 0.47). However, there was no effect on survival (Cohen’s d = 0.05). Pirotta (2022) covered the development of bioenergetic models [‘‘any mechanistic model where the principles of metabolic ecology are used to describe how an individual animal acquires energy from food resources (i.e., energy intake) and allocates assimilated energy to various life history functions (i.e., energy costs, including maintenance and survival, growth and reproduction)’’] with a focus on applications to marine mammals. This article provided a thorough overview of the history of marine mammal bioenergetic models, defined relevant terminology, and explained the differences between general types of models. McHuron et al. (2021) developed a state-dependent behavioral and life history model to predict the probability of Western gray whale mother-calf pair survival with and without acoustic disturbance and with or without adequate prey availability on their summer foraging grounds. Pregnant mother movement, feeding behavior, fat mass and fetal length were input data for the model. Since prey availability was co-dependent on whales having access to high-density offshore areas by mid-July, nearshore seismic surveys had no impact on population fecundity or mother-calf survival. This model overcomes a key challenge in PCoD literature by providing a link between behavioral responses and vital rates; authors recommend focusing on species that are data rich to accurately characterize the biology of the focal species, metrics of fitness, and key qualities of their environment. Joy et al. (2022) presented a hypothetical case study for fin whales off Southern California exposed to stationary single-ship 53C sonar events over the course of a year, using the Navy’s Phase 3 behavioral response function (BRF). Two model runs were compared: using a = 0.05 (average 20- VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 minute movement disruption) and a= 0.99 (average 3 days movement disruption). When animals returned to baseline behavior after a short disturbance (a = 0.05), there was less regional displacement and thus more instances of behavioral disturbance over the course of a year. When animals returned to baseline behavior after a longer period (a=0.99), there were fewer instances of behavioral disturbances over the course of a year due to cumulative displacement from habitat near the sonar source. Keen et al. (2021) reviewed 15+ years of PCoD modeling and identified the most critical factors for determining long-term impacts to populations. Critical factors include life-history traits, disturbance source characteristics, and environmental conditions. No specific model or quantitative assessment was proposed. Methodology for Assessing Acoustic Impacts Palmer et al. (2022) recorded North Atlantic right whale upcalls using 10 Marine Autonomous Recording Units deployed in Cape Cod Bay from February to May 2009. A modified equation was provided for determining the effective survey area, including a Lombard coefficient, for single sensor applications. The authors state manual annotation or verification is nearly always used to confirm automated detector outputs prior to near-real-time conservation measures due to limitations in automatic detector capabilities. Aircraft Noise Kuehne et al. (2020) measured in-air and underwater sound from lowaltitude EA–18G Growler flights in the immediate vicinity of Ault Field at Naval Air Station Whidbey Island (NASWI). Data were collected by two inair recorders and one hydrophone placed just off the runway at a depth of 30 meters. The underwater 10-flight average sound measurement was 134 ± 3 dB re 1 mPa rms in the highest 1second window. The results showed that the peak frequency range of the Growler overflight noise both in air and underwater was between 50 and 1,000 Hz, which is typically a frequency range with high background noise underwater, particularly in areas with large amounts of vessel traffic (Erbe et al. 2012). The study did not include behavioral observations of wildlife, and the authors’ conclusions about potential impacts to wildlife were unsupported by data from the study. In a separate effort, Kuehne and Olden (2020) relied on volunteers to identify military PO 00000 Frm 00022 Fmt 4701 Sfmt 4702 aircraft noise in recordings taken on land on the Olympic Peninsula. This study also did not examine impacts to or responses by wildlife to aircraft. We reiterate that NMFS reviewed the Navy’s analysis and conclusions that aircraft noise will not result in incidental take of marine mammals, and finds the analysis and conclusions complete and supportable, as stated in the 2018 HSTT final rule. Please see section 3.7 (Marine Mammals) of the 2018 HSTT FEIS/OEIS for additional information. Conclusion for New Pertinent Science Since Publication of the 2020 HSTT Final Rule Having considered the best scientific information available, specifically new relevant information published since the 2020 HSTT final rule, we have preliminarily determined that there is no new information that substantively affects our analysis of impacts on marine mammals and their habitat that appeared in the 2020 HSTT final rule, all of which remains applicable and valid for our assessment of the effects of the Navy’s activities during the 7-year period of this rulemaking. Estimated Take of Marine Mammals This section indicates the number of takes that NMFS is proposing for authorization, which are based on the amount of take that NMFS anticipates could occur or is likely to occur, depending on the type of take and the methods used to estimate it, as described below. NMFS coordinated closely with the Navy in the development of their incidental take application and preliminarily agrees that the methods the Navy has put forth described herein, in the 2019 HSTT proposed rule, 2020 HSTT final rule, and in the 2018 HSTT proposed and final rules to estimate take (including the model, thresholds, and density estimates), and the resulting numbers are based on the best available science and appropriate for authorization, with the exception of that of humpback whales, discussed further below. The number and type of incidental takes that could occur or are likely to occur annually remain identical to those authorized in the 2018 HSTT regulations and 2020 HSTT regulations, with the exception of proposed takes by serious injury or mortality by vessel strike and harassment takes of humpback whale stocks in Southern California (due to the new stock structure). Takes are predominantly in the form of harassment, but a small number of serious injuries or mortalities could E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules occur. For military readiness activities, the MMPA defines ‘‘harassment’’ as (i) any act that injures or has the significant potential to injure a marine mammal or marine mammal stock in the wild (Level A harassment); or (ii) any act that disturbs or is likely to disturb a marine mammal or marine mammal stock in the wild by causing disruption of natural behavioral patterns, including, but not limited to, migration, surfacing, nursing, breeding, feeding, or sheltering, to a point where such behavioral patterns are abandoned or significantly altered (Level B harassment). Proposed authorized takes would primarily be in the form of Level B harassment, as use of the acoustic and explosive sources (i.e., sonar, air guns, pile driving, explosives) and is more likely to result in the disruption of natural behavior patterns to a point where they are abandoned or significantly altered (as defined specifically at the beginning of this section but referred to generally as behavioral disturbance) or TTS for marine mammals. There is also the potential for Level A harassment in the form of auditory injury and/or tissue damage (the latter from explosives only) to result from exposure to the sound sources utilized in training and testing activities. Additionally, serious injuries or mortalities of mysticetes (except for sei whales, minke whales, Bryde’s whales, Central North Pacific stock of blue whales, Hawaii stock of fin whales, Western North Pacific stock of gray whales, and sperm whales) could occur through vessel strike. Proposed mitigation and monitoring measures are expected to minimize the severity of the taking to the extent practicable. Generally speaking, for acoustic impacts, NMFS estimates the amount and type of harassment by considering: (1) acoustic thresholds above which NMFS believes the best available science indicates marine mammals would experience behavioral disturbance or incur some degree of temporary or permanent hearing impairment; (2) the area or volume of water that will be ensonified above these levels in a day or event; (3) the density or occurrence of marine mammals within these ensonified areas; and (4) and the number of days of activities or events. Acoustic Thresholds Using the best available science, NMFS, in coordination with the Navy, has established acoustic thresholds that identify the most appropriate received level of underwater sound above which marine mammals exposed to these sound sources could be reasonably VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 expected to experience a disruption in behavior patterns to a point where they are abandoned or significantly altered or to incur TTS (equated to Level B harassment) or permanent threshold shift (PTS) of some degree (equated to Level A harassment). Thresholds have also been developed to identify the pressure levels above which animals may incur non-auditory injury from exposure to pressure waves from explosive detonation. We described the acoustic thresholds and the methods used to determine thresholds, none of which have changed, in detail in the Acoustic Thresholds section of the 2018 HSTT final rule; please see the 2018 HSTT final rule for detailed information. Further, in the 2020 HSTT final rule, we described new relevant information from the scientific literature since publication of the 2018 HSTT final rule. Since publication of the 2020 HSTT final rule, a number of additional studies have published, including several associated with TTS in harbor porpoises and seals (e.g., Kastelein et al. 2020d; Kastelein et al. 2021a and 2021b; Sills et al. 2020). NMFS is aware of these recent papers, summarized above in the New Pertinent Science Since Publication of the 2020 HSTT Final Rule section. NMFS is currently working with the Navy to update NMFS’ Technical Guidance for Assessing the Effects of Anthropogenic Sound on Marine Mammal Hearing Version 2.0 (Acoustic Technical Guidance; NMFS 2018) to reflect relevant papers that have been published since the 2018 update on our 3–5 year update schedule in the Acoustic Technical Guidance. First, we note that the recent peerreviewed updated marine mammal noise exposure criteria by Southall et al. (2019) provide identical PTS and TTS thresholds and weighting functions to those provided in NMFS’ Acoustic Technical Guidance. NMFS will continue to review and evaluate new relevant data as it becomes available and consider the impacts of those studies on the Acoustic Technical Guidance to determine what revisions or updates may be appropriate. However, any such revisions must undergo peer and public review before being adopted, as described in the Acoustic Technical Guidance methodology. While some of the relevant data may potentially suggest changes to TTS/PTS thresholds for some species, any such changes would not be expected to change the predicted take estimates in a manner that would change the necessary determinations supporting the issuance of these regulations, and the data and values PO 00000 Frm 00023 Fmt 4701 Sfmt 4702 68311 used in this proposed rule reflect the best available science. Navy’s Acoustic Effects Model The Navy proposes no changes to the Acoustic Effects Model as described in the 2018 HSTT final rule (and incorporated by reference in the 2020 HSTT final rule), and there is no new information that would affect the applicability or validity of the model. Please see the 2018 HSTT final and proposed rules and Appendix E of the 2018 HSTT FEIS/OEIS for detailed information. Range to Effects The Navy proposes no changes from the 2018 HSTT final rule (and subsequent 2020 HSTT final rule) to the type and nature of the specified activities to be conducted during the 7year period analyzed in this proposed rule, including equipment and sources used and exercises conducted. NMFS has reviewed and will continue to review and evaluate new relevant data as it becomes available and consider the impacts of those studies on the Acoustic Technical Guidance to determine what revisions/updates may be appropriate. However, any such revisions must undergo peer and public review before being adopted, as described in the Acoustic Guidance methodology. While some of the relevant data may potentially suggest changes to TTS/PTS thresholds for some species (e.g., Kastelein et al. (2020a) shows onset of TTS incurred by a harbor porpoise at higher received levels than would have been anticipated based on the existing criteria, while Kastelein et al. (2022a) shows onset of TTS in otariids in water at lower received levels than the existing criteria), our assessment suggests that any such changes would not be expected to change the predicted take estimates in a manner that would change the necessary determinations supporting the issuance of these regulations, and the data and values used in the 2018 HSTT final rule, 2020 HSTT final rule, and this proposed rule reflect the best available science. Therefore, the ranges to effects in this proposed rule are identical to those described and analyzed in the 2018 HSTT final rule and 2020 HSTT final rule, including received sound levels that may cause onset of significant behavioral response and TTS and PTS in hearing for each source type or explosives that may cause non-auditory injury. Please see the Range to Effects section and tables 24 through 40 of the 2018 HSTT final rule for detailed information. E:\FR\FM\03OCP2.SGM 03OCP2 68312 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules ddrumheller on DSK120RN23PROD with PROPOSALS2 Marine Mammal Density The Navy proposes no changes to the methods used to estimate marine mammal density described in the 2018 HSTT final rule, and there is no new information that would affect the applicability or validity of these methods or change the results in a manner that would change the necessary determinations supporting the issuance of these regulations. The Navy’s estimate of marine mammal density as described in the 2018 HSTT final rule remains valid, though, as described herein, NMFS has incorporated new information regarding humpback whale stock structure into its analysis. Please see the 2018 HSTT final rule, and below, for detailed information. As noted above, NMFS regularly updates SARs, and in this rulemaking considers the 2022 final SARs (Carretta et al. 2023, Young et al. 2023). While these SARs contain updated information, the Navy’s estimate of marine mammal density as described in the 2018 HSTT final rule remains valid for the following reasons. The Navy uses its Marine Species Density Database (NMSDD) for its analysis, which is derived from multiple sources, including but not limited to SARs. In contrast, for most cetacean species, the SAR is estimated using line-transect surveys or mark-recapture studies (e.g., Barlow, 2010; Barlow and Forney, 2007; Calambokidis et al. 2008). The result provides one single abundance value for each species across broad geographic areas, but it does not provide information on the species density or concentrations within that area, and it does not estimate density for other timeframes or seasons that were not surveyed. A change in a stock’s abundance indicated in a SAR does not necessarily indicate a change in that stock’s density in any given area. Therefore, stocks in the HSTT Study Area with higher abundance estimates in the most recent SARs in comparison to the abundance estimates at the time that marine mammal densities were derived for the HSTT Study Area do not necessarily now occur in higher densities in the HSTT Study Area. For humpback whale, while the stock structure in the Pacific Ocean was revised in the 2022 final SARs, the discussion above remains true regarding density of humpback whales in the HSTT Study Area across all stocks. Take Requests As in the 2018 HSTT final rule and 2020 HSTT final rule, the Navy determined that the three stressors VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 below could result in the incidental taking of marine mammals. NMFS has reviewed the Navy’s data and analysis and determined that it is complete and accurate, and NMFS agrees that the following stressors have the potential to result in takes of marine mammals from the Navy’s planned activities: • Acoustics (sonar and other transducers; air guns; pile driving/ extraction); • Explosives (explosive shock wave and sound, assumed to encompass the risk due to fragmentation); and • Physical Disturbance and Strike (vessel strike). NMFS reviewed and agrees with the Navy’s conclusion that acoustic and explosive sources have the potential to result in incidental takes of marine mammals by harassment, serious injury, or mortality. NMFS carefully reviewed the Navy’s analysis and conducted its own analysis of vessel strikes, determining that the likelihood of any particular species of large whale being struck is quite low. However, as noted previously, in 2021, two separate U.S. Navy vessels struck unidentified large whales on two separate occasions, one whale in June 2021 and one whale in July 2021. In May 2023, the U.S. Navy struck a large whale, which based on available photos and video, NMFS and the Navy have determined was either a fin whale or sei whale. NMFS agrees that vessel strikes have the potential to result in incidental take from serious injury or mortality for certain species of large whales, and the Navy has specifically requested coverage for these species. Therefore, the likelihood of vessel strikes, and later the effects of the incidental take that is being proposed to be authorized, has been fully analyzed and is described below. Regarding the quantification of expected takes from acoustic and explosive sources (by Level A and Level B harassment, as well as mortality resulting from exposure to explosives), the number of takes are based directly on the level of activities (days, hours, counts, etc., of different activities and events) in a given year. In the 2020 HSTT final rule, take estimates across the 7 years were based on the Navy conducting 4 years of a representative level of activity and 3 years of maximum level of activity. As in the 2020 HSTT final rule, the Navy proposes to use the maximum annual level to calculate annual takes (which would remain identical to what was determined in the 2020 HSTT final rule, with the exception of attribution of takes to humpback whale stocks), and the sum of all years (4 representative PO 00000 Frm 00024 Fmt 4701 Sfmt 4702 and 3 maximum) to calculate the 7-year totals for this rulemaking. The quantitative analysis process used for the 2018 HSTT FEIS/OEIS and the 2017 and 2019 Navy applications to estimate potential exposures to marine mammals resulting from acoustic and explosive stressors is detailed in the technical report titled Quantifying Acoustic Impacts on Marine Mammals and Sea Turtles: Methods and Analytical Approach for Phase III Training and Testing (U.S. Department of the Navy, 2018). The Navy Acoustic Effects Model estimates acoustic and explosive effects without taking mitigation into account; therefore, the model overestimates predicted impacts on marine mammals within mitigation zones. To account for mitigation for marine species in the take estimates, the Navy conducts a quantitative assessment of mitigation. The Navy conservatively quantifies the manner in which procedural mitigation is expected to reduce the risk for model-estimated PTS for exposures to sonars and for model-estimated mortality for exposures to explosives, based on species sightability, observation area, visibility, and the ability to exercise positive control over the sound source. Where the analysis indicates mitigation would effectively reduce risk, the modelestimated PTS are considered reduced to TTS and the model-estimated mortalities are considered reduced to injury. For a complete explanation of the process for assessing the effects of mitigation, see the 2017 Navy application and the Take Requests section of the 2018 HSTT final rule. The extent to which the mitigation areas reduce impacts on the affected species and stocks is addressed separately in the Preliminary Analysis and Negligible Impact Determination section. No changes have been made to the quantitative analysis process to estimate potential exposures to marine mammals resulting from acoustic and explosive stressors and calculate take estimates, with the exception of take of humpback whales to account for the change in stock structure. Please see the documents described in the paragraph above, the 2018 HSTT proposed rule, the 2018 HSTT final rule, and below for detailed descriptions of these analyses. While Oedekoven and Thomas (2022) suggest that detection of marine mammals is less certain than previously assumed at certain distances, NMFS has independently evaluated the Navy’s method for application of mitigation effectiveness in estimating take and agrees that it is appropriately applied to augment the model in the prediction and authorization of injury and E:\FR\FM\03OCP2.SGM 03OCP2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules ddrumheller on DSK120RN23PROD with PROPOSALS2 mortality as described in the rule, including after consideration of Oedekoven and Thomas (2022). In summary, we believe the Navy’s methods, including the method for incorporating mitigation and avoidance, are the most appropriate methods for predicting PTS, TTS, and behavioral disturbance. But even with the consideration of mitigation and avoidance, given some of the more conservative components of the methodology (e.g., the thresholds do not consider ear recovery between pulses), we would describe the application of these methods as identifying the maximum number of instances in which marine mammals would be reasonably expected to be taken through PTS, TTS, or behavioral disturbance. Summary of Requested Take From Training and Testing Activities Based on the methods discussed in the previous sections and the Navy’s model and quantitative assessment of mitigation, the Navy provided its take estimate and request for authorization of takes incidental to the use of acoustic and explosive sources for training and testing activities both annually (based on the maximum number of activities that could occur per 12-month period) and over the 7-year period in its 2019 rulemaking/LOA application. With the exception of changes to humpback whale take, described below, annual takes (based on the maximum number of activities that could occur per 12-month period) from the use of acoustic and explosive sources are identical to those presented in tables 41 and 42 and in the Explosives subsection of the Take Requests section of the 2018 HSTT final rule. The 2022 Navy application includes the Navy’s updated take estimate and request for take by vessel strike due to vessel movement in the HSTT Study Area. NMFS reviewed the Navy’s data, methodology, and analysis and determined that it was complete, but NMFS has reanalyzed the potential for vessel strike following the May 2023 strike, as described in the Estimated Take from Vessel Strikes and Explosives by Serious Injury or Mortality section. NMFS agrees that the estimates for incidental takes by harassment from all sources as well as the incidental takes by serious injury or mortality from explosives requested for authorization are the maximum number of instances VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 in which marine mammals are reasonably expected to be taken at the time of Navy’s request, and continues to be for all stocks other than humpback whales, for which changes are described below. NMFS also agrees that the takes by serious injury or mortality as a result of vessel strikes could occur. Note that, consistent with the 2020 HSTT final rule, the total amount of estimated incidental take from acoustic and explosive sources over the total 7-year period covered by the 2019 Navy application is less than the annual total multiplied by seven. Although the annual estimates are based on the maximum number of activities per year and therefore, the maximum possible estimated takes, the 7-year total take estimates are based on the sum of 3 maximum years and 4 representative years, with the exception of humpback whale stocks that occur in SOCAL for which 7-year total take is conservatively estimated as the annual total multiplied by seven. Not all activities occur every year. Some activities would occur multiple times within a year, and some activities would occur only a few times over the course of the 7-year period. Using 7 years of the maximum number of activities each year would vastly overestimate the amount of incidental take that would occur over the 7-year period where the Navy knows that it will not conduct the maximum number of activities each and every year for the 7 years. As described above in the Description of Marine Mammals and Their Habitat in the Area of the Specified Activities section, the 2022 final SARs include a revision to the humpback whale stock structure in the Pacific Ocean. In the 2020 HSTT final rule, NMFS authorized take of the CA/OR/WA stock and Central North Pacific stock of humpback whale. Given the revised stock structure, in this proposed rule, NMFS has reanalyzed the potential for take of each stock of humpback whale and determined that the Central America/ Southern Mexico-CA/OR/WA, Mainland Mexico—CA/OR/WA stock, and Hawaii stocks are likely to be taken by the Navy’s activities. Under the new stock structure, the Hawaii stock (Hawaii DPS) is the only stock that would occur in Hawaii. Therefore, the Hawaii stock of humpback whale is the only humpback whale stock anticipated to be taken by PO 00000 Frm 00025 Fmt 4701 Sfmt 4702 68313 the Navy’s activities in the HRC, and all takes of the Central North Pacific stock of humpback whale that were authorized in the 2020 HSTT final rule are anticipated to be of individuals from the new Hawaii stock. In SOCAL, the takes of individuals from the former CA/ OR/WA stock that were authorized in the 2020 HSTT final rule are anticipated to be of individuals from the new Central America/Southern Mexico-CA/ OR/WA and Mainland Mexico-CA/OR/ WA stock. Please see the Estimated Harassment Take from Testing Activities and Estimated Harassment Take from Training Activities sections below for the estimated annual and 7-year total number and type of Level A harassment and Level B harassment for each humpback whale stock. Estimated Harassment Take From Training Activities For training activities, table 11 of the 2020 HSTT final rule summarizes the Navy’s take estimate and request in the 2019 Navy application and the maximum amount and type of Level A harassment and Level B harassment that NMFS concurred is reasonably expected to occur by species or stock and authorized in the 2020 HSTT LOA. In the 2022 Navy application, the Navy requested no change to this authorized take, though as described above, NMFS has since published the 2022 final SARs, which include a revision to humpback whale stock structure. For the estimated 7-year total amount and type of Level A harassment and Level B harassment, see table 11 of the 2020 HSTT final rule for all species other than humpback whale. For the estimated amount and type of Level A harassment and Level B harassment annually, see table 41 in the 2018 HSTT final rule for all species other than humpback whale. Note that take by Level B harassment includes both behavioral disturbance and TTS. Navy Figures 6–12 through 6–50 in Section 6 of the 2017 Navy application illustrate the comparative amounts of TTS and behavioral disturbance for each species annually, noting that if a modeled marine mammal was ‘‘taken’’ through exposure to both TTS and behavioral disturbance in the model, it was recorded as a TTS. E:\FR\FM\03OCP2.SGM 03OCP2 68314 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules TABLE 2—HUMPBACK WHALE TAKE FROM ACOUSTIC AND EXPLOSIVE EFFECTS FOR ALL TRAINING ACTIVITIES IN THE HSTT STUDY AREA Annual Species Stock Humpback whale a ................ Hawaii ........................................................... Central America/Southern Mexico-CA/OR/ WA (Central America DPS). Mainland Mexico—CA/OR/WA (Mexico DPS). Level B harassment 7-Year total Level A harassment Level B harassment Level A harassment 5,604 585 1 0 b 4,095 34,437 12 0 669 1 b 4,683 7 a Combined, takes from the Central America/Southern Mexico- CA/OR/WA stock and the Mainland Mexico CA/OR/WA stock are equal to takes of the CA/OR/WA stock authorized in the 2020 HSTT final rule. b Unlike other species and stocks, for the Central America/Southern Mexico-CA/OR/WA stock and Mainland Mexico-CA/OR/WA stock, NMFS estimated the 7-year take by Level B harassment by multiplying the annual estimated take by seven. However, between the two stocks, NMFS does not anticipate that the total number of takes by Level B harassment across all 7 years would exceed the 7,962 takes by Level B harassment from training activities that were authorized for the CA/OR/WA stock of humpback whales in the 2020 HSTT final rule. Estimated Harassment Take From Testing Activities For testing activities, table 12 of the 2020 HSTT final rule summarizes the Navy’s take estimate and request in the 2019 Navy application and the maximum amount and type of Level A harassment and Level B harassment that NMFS concurred is reasonably expected to occur by species or stock and harassment includes both behavioral disturbance and TTS. Navy Figures 6– 12 through 6–50 in section 6 of the 2017 Navy application illustrate the comparative amounts of TTS and behavioral disturbance for each species annually, noting that if a modeled marine mammal was ‘‘taken’’ through exposure to both TTS and behavioral disturbance in the model, it was recorded as a TTS. authorized in the 2020 HSTT LOA. In the 2022 Navy application, the Navy requested no change to this authorized take. For the estimated 7-year total amount and type of Level A harassment and Level B harassment, see table 12 of the 2020 HSTT final rule. For the estimated amount and type of Level A harassment and Level B harassment annually, see table 42 in the 2018 HSTT final rule. Note that take by Level B TABLE 3—HUMPBACK WHALE TAKE FROM ACOUSTIC AND EXPLOSIVE EFFECTS FOR ALL TESTING ACTIVITIES IN THE HSTT STUDY AREA Annual Species Stock Humpback whale a ................ Hawaii ........................................................... Central America/Southern Mexico—CA/OR/ WA. Mainland Mexico—CA/OR/WA .................... Level B harassment 7-Year total Level A harassment Level B harassment 23,750 Level A harassment 3,522 291 2 0 b 2,037 19 0 449 0 b 3,143 0 a Combined, ddrumheller on DSK120RN23PROD with PROPOSALS2 takes from the Central America/Southern Mexico-CA/OR/WA stock and the Mainland Mexico CA/OR/WA stock are equal to takes of the CA/OR/WA stock authorized in the 2020 HSTT final rule. b Unlike other species and stocks, for the Central America/Southern Mexico-CA/OR/WA stock and Mainland Mexico-CA/OR/WA stock, NMFS estimated the 7-year take by Level B harassment by multiplying the annual estimated take by seven. However, between the two stocks, NMFS does not anticipate that the total number of takes by Level B harassment across all 7 years would exceed the 4,961 takes by Level B harassment from testing activities that were authorized for the CA/OR/WA stock of humpback whales in the 2020 HSTT final rule. Estimated Take From Vessel Strikes and Explosives by Serious Injury or Mortality Vessel Strike Vessel strikes from commercial, recreational, and military vessels are known to affect large whales and have resulted in serious injury and fatalities to cetaceans (Abramson et al. 2011; Berman-Kowalewski et al. 2010; Calambokidis, 2012; Douglas et al. 2008; Laggner, 2009; Lammers et al. 2003; Van der Hoop et al. 2012; Van der Hoop et al. 2013; Crum et al. 2019). Records of collisions date back to the early 17th century, and the worldwide number of collisions appears to have increased steadily during recent decades (Laist et al. 2001; Ritter 2012) due to increases in the number and speed of large vessels, VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 increased reporting of strikes, and increased abundance of some large whales (Ransome et al. 2021), among other factors. Numerous studies of interactions between surface vessels and marine mammals have demonstrated that freeranging marine mammals often, but not always (e.g., McKenna et al. 2015; Smultea et al. 2022; Szesciorka et al. 2019), engage in avoidance behavior when surface vessels move toward them. It is not clear whether these responses are caused by the physical presence of a surface vessel, the underwater noise generated by the vessel, or an interaction between the two (Amaral and Carlson, 2005; Au and Green, 2000; Bain et al. 2006; Bauer PO 00000 Frm 00026 Fmt 4701 Sfmt 4702 1986; Bejder et al. 1999; Bejder and Lusseau, 2008; Bejder et al. 2009; Bryant et al. 1984; Corkeron, 1995; Erbe, 2002; Fe´lix, 2001; Goodwin and Cotton, 2004; Lemon et al. 2006; Lusseau, 2003; Lusseau, 2006; Magalhaes et al. 2002; Nowacek et al. 2001; Richter et al. 2003; Scheidat et al. 2004; Simmonds, 2005; Watkins, 1986; Williams et al. 2002; Wursig et al. 1998). Several authors suggest that the noise generated during vessel movement is probably an important factor (Blane and Jaakson, 1994; Evans et al. 1992; Evans et al. 1994). Water disturbance may also be a factor. These studies suggest that the behavioral responses of marine mammals to surface vessels are similar to their behavioral responses to E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules predators. Avoidance behavior is expected to be even stronger in the subset of instances during which the Navy is conducting training or testing activities using active sonar or explosives. The marine mammals most vulnerable to vessel strikes are those that spend extended periods of time at the surface to restore oxygen levels within their tissues after deep dives (e.g., sperm whales). In addition, some baleen whales seem generally unresponsive to vessel sound, making them more susceptible to vessel collisions (Nowacek et al. 2004). These species are primarily large, slow-moving whales. Some researchers have suggested the relative risk of a vessel strike can be assessed as a function of animal density and the magnitude of vessel traffic (e.g., Fonnesbeck et al. 2008; Vanderlaan et al. 2008). Differences among vessel types also influence the probability of a vessel strike. The ability of any ship to detect a marine mammal and avoid a collision depends on a variety of factors, including environmental conditions, ship design, size, speed, and ability and number of personnel observing, as well as the behavior of the animal. Vessel speed, size, and mass are all important factors in determining if injury or death of a marine mammal is likely due to a vessel strike. For large vessels, speed and angle of approach can influence the severity of a strike. For example, Vanderlaan and Taggart (2007) found that between vessel speeds of 8.6 and 15 kn (15.9 and 27.8 km per hour), the probability that a vessel strike is lethal increases from 0.21 to 0.79. Large whales also do not have to be at the water’s surface to be struck. Silber et al. (2010) found when a whale is below the surface (about one to two times the vessel draft), there is likely to be a pronounced propeller suction effect. This suction effect may draw the whale into the hull of the ship, increasing the probability of propeller strikes. There are some key differences between the operation of military and non-military vessels, which make the likelihood of a military vessel striking a whale lower than some other vessels (e.g., commercial merchant vessels). Key differences include: • Many military ships have their bridges positioned closer to the bow, offering better visibility ahead of the ship (compared to a commercial merchant vessel); • There are often aircraft associated with the training or testing activity (which can serve as Lookouts), which can more readily detect cetaceans in the vicinity of a vessel or ahead of a vessel’s VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 present course before crew on the vessel would be able to detect them; • Military ships are generally more maneuverable than commercial merchant vessels, and if cetaceans are spotted in the path of the ship, could be capable of changing course more quickly; • The crew size on military vessels is generally larger than merchant ships, allowing for stationing more trained Lookouts on the bridge. At all times when vessels are underway, trained Lookouts and bridge navigation teams are used to detect objects on the surface of the water ahead of the ship, including cetaceans. Additional Lookouts, beyond those already stationed on the bridge and on navigation teams, are positioned as Lookouts during some training events; and • When submerged, submarines are generally slow moving (to avoid detection), and therefore, marine mammals at depth with a submarine are likely able to avoid collision with the submarine. When a submarine is transiting on the surface, there are Lookouts serving the same function as they do on surface ships. Vessel strike to marine mammals is not associated with any specific training or testing activity but is rather a limited and sporadic, but possible, accidental result of Navy vessel movement within the HSTT Study Area or while in transit. In 2009, the Navy began implementing additional mitigation measures to further reduce the likelihood of vessel strikes. Prior to the recent strikes in 2021 and 2023, there were two recorded U.S. Navy vessel strikes of large whales in the HSTT Study Area between 2009 and April 2021, a period of approximately 12 years. Since 2021 there have been five documented strikes of large whales in SOCAL by naval vessels, three by the U.S. Navy and two by the Royal Australian Navy. As stated previously, the U.S. Navy struck a large whale in waters off Southern California in May 2023. Based on available photos and video, NMFS and the Navy have determined this whale was either a fin whale or sei whale. The U.S. Navy struck two unidentified large whales during the months of June and July 2021, and prior to that, on May 7, 2021, the Royal Australian Navy HMAS Sydney, a 147.5 m (161.3 yd) Hobart Class Destroyer, struck and killed two fin whales (a mother and her calf) while operating within SOCAL. In the case of the Royal Australian Navy strike, the carcasses were first sighted under the bow of the vessel while it was PO 00000 Frm 00027 Fmt 4701 Sfmt 4702 68315 approaching the Naval Base in San Diego. The whales had been pinned to a sonar dome in the front of the vessel due to the force of water as the ship was underway. Based on interviews with HMAS Sydney personnel, the most likely time of impact with the two whales would have been around 6:25 a.m. when the vessel was located near Cortes Bank, and visibility was poor. The reported vessel speed at the estimated time of strike was 9 kn (16.7 km per hour). One minute before the estimated strike time a lookout reported whales off the starboard bow. The officer on-watch verbally acknowledged the report, slowed speed, and visually tracked the whales passing clear down the starboard side until they were clear of the ship. The morning of the strike, the HMAS Sydney was getting into position to participate in a U.S. Navyled exercise later that day. Of note, throughout the remainder of the day visibility was poor and the vessel had implemented mitigation measures in multiple instances due to whale occurrence. In addition to being the only documented occurrence of a foreign military vessel strike of a large whale within the HSTT Study Area, the HMAS Sydney vessel strike was also somewhat unique, as compared to other reported military vessel strikes, in that two whales were apparently struck at one time, and both remained pinned to the front of the vessel until the vessel approached the port. On June 29, 2021, a U.S. Navy cruiser struck an unknown whale species approximately 95 nmi west of San Diego. The ship was returning from Hawaii, heading to a rendezvous with a fuel replenishment vessel (oiler) for an Underway Replenishment. Off-duty sailors noticed a group of whales approaching the ship from the port quarter (i.e., left rear of the ship), an area unique to cruisers with some equipment structures blocking close aboard sight. The first indication of a whale within the 500-yd mitigation zone immediately prior to the strike was when an off-duty sailor on the flight deck witnessed the whale briefly surface on the aft port quarter before diving. Shortly after this occurred blood was noticed in the wake, and a floating whale body was eventually observed behind the ship. The ship’s speed was 25 kn (46.3 km per hour) at the estimated time the strike occurred. The Navy also noted that, on the morning before the strike occurred, the ship had maneuvered several times to avoid whale blows beyond the 500yd (457.2 m) mitigation zone, closer to 1,000 yd (914.4 m). On July 11, 2021, a U.S. Navy cruiser struck an unknown whale species E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68316 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules approximately 90 nmi (166.7 km) southsouthwest of San Diego. The vessel was a participant in a MTE (Large Integrated Anti-Submarine Warfare—Composite Unit Training Exercise) within the SOCAL portion of the action area. The vessel was maneuvering for pending flight operations to receive an inbound helicopter. At 2:27 p.m., the starboard lookout sighted what they believed to be a whale crossing immediately under the vessel’s bow. The conning officer attempted to maneuver the vessel by turning to port but internal watchstanders subsequently felt the ship shudder aft. The vessel’s combat center observed a red slick 600 yd (548.6 m) astern on a flight deck camera and a brief surfacing of the whale itself, but no carcass was observed. There had not been any sightings of large whales off the bow leading up to the incident. Although the ship was traveling at 25– 30 kn (46.3–55.6 km per hour) one hour before the estimated strike time, at ten minutes before, the vessel changed course and reduced its speed to 17 kn (31.5 km per hour). These 2021 incidents were the first known U.S. Navy vessel strikes in the HSTT Study Area since 2009. On May 20, 2023, a U.S. Navy aircraft carrier was at sea conducting independent, unit-level flight training for the embarked airwing approximately 70 nmi west of San Diego. Training exercises concluded for the day at approximately 7:44 p.m. local time. Navy personnel discovered a whale impinged on the bow of the vessel at approximately 8:00 p.m. local time. The vessel was traveling at approximately 5 kn and had recently made a turn to reset position for the evening when the Navy personnel discovered the whale. Navy personnel captured video and photos of the carcass, and based on those images, NMFS and the Navy have determined this whale was either a fin whale or sei whale; the two species are very similar morphologically and are difficult to distinguish from one another at sea. Navy personnel stopped the vessel to allow lack of momentum to dislodge the carcass from the bow, and based on lack of further observations after the carcass dislodged, it is believed to have sunk around 9:30 p.m. local time. Navy personnel on board the vessel reported that they did not feel an impact from striking the whale. Prior to the strike, between 6:45 p.m. and 7:45 p.m., the forward Lookouts on the vessel observed two whales crossing the vessel’s bow but did not provide a distance between the vessel and the whales. One Lookout reported seeing the blow and the other reported seeing VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 ‘humps’ (presumably the dorsal of the animal). Both whales were sighted past the ship’s course to the northwest. Within the same time window, one of the aft Lookouts observed a single whale swimming parallel to the ship and soon passed astern of the ship. During the same time, independent of the sightings and for general movement reasons, the ship changed speed from 17 knots to 10 knots at 7:22 p.m. For the same reasons listed above describing why the likelihood of a military vessel striking a whale is lower than that of some other vessels striking whales, it is also highly unlikely that a Navy vessel would strike a whale, dolphin, porpoise, or pinniped without detecting it. Specifically, Navy ships have Lookouts, including on the forward part of the ship that can visually detect a hit animal in the event ship personnel do not feel the strike (which has occurred). Accordingly, NMFS is confident that the Navy’s reported strikes are accurate and appropriate for use in the analysis. Navy’s strict internal procedures and mitigation requirements include reporting of any vessel strikes of marine mammals, and the Navy’s discipline, extensive training (not only for detecting marine mammals, but for detecting and reporting any potential navigational obstruction), and strict chain of command give NMFS a high level of confidence that all strikes actually get reported. As noted above, the 2021 Royal Australian Navy vessel strikes were first observed when the vessel came to port at Naval Base San Diego. However, such a scenario is unlikely on a U.S. Navy vessel. While U.S. Navy cannot speculate on the configurations of other ships bows and even sonar dome specifications (that may be at the bow), the Navy believes it would be implausible for a marine mammal to become lodged on the sonar dome of a U.S. Navy ship and remain undetected due to a technological standard operating procedure. Sonar domes on U.S. Navy ships have a pressurized rubber window that maintains 150 pound-force per square inch (PSI) through the ship’s fire main. If anything affects the pressure, an alarm sounds in the sonar control room. In the event of a whale strike in that location, this alarm would alert personnel that something hit the sonar dome. Further, the shape, hydrodynamic design, construction using a non-abrasive material, and regular hull cleaning procedures to remove barnacles and other growth on U.S. Navy ships also make it unlikely that a whale would become lodged and remain undetected PO 00000 Frm 00028 Fmt 4701 Sfmt 4702 on a U.S. Navy ship’s bow or even sonar dome. While in the case of the May 2023 strike, described above, a whale also became lodged on the ship’s bow, the aircraft carrier that struck the whale does not have active or passive sonar capabilities (i.e., no sonar dome), nor does it have a bulbous bow, and the whale was more quickly discovered by Navy personnel. In order to better account for the accidental nature of vessel strikes to large whales in general and the potential risk from U.S. Navy vessel movement within the HSTT Study Area during the remaining period of the HSTT rule in particular, the Navy requested the HSTT rule be modified to authorize additional incidental takes by vessel strike based on probabilities derived from a Poisson distribution using vessel strike data between 2009–2021 in the HSTT Study Area (the time period from when current mitigations were instituted until the Navy conducted the analysis for the 2022 Navy application), as well as historical at-sea days in the HSTT Study Area from 2009–2015 and estimated atsea days for the period from 2016 to 2025 covered by the current regulations. This distribution predicted the probabilities of a specific number of strikes (n=0, 1, 2, etc.) over the remaining period of the regulations at the time of the Navy’s analysis (2022– 2025). The Navy used the two fin whale strikes (2009) and two unidentified large whale strikes (2021) in their calculations to determine the number of strikes likely to result from its activities over the remaining 3 years of the rule (2023–2025, although worldwide strike information from all Navy activities and other sources was used to inform the species that may be struck). The Navy evaluated data beginning in 2009 as that was the start of the Navy’s Marine Species Awareness Training and adoption of additional mitigation measures to address vessel strike, which will remain in place along with additional and modified mitigation measures during the 7 years of this rulemaking. From this analysis, the Navy concluded that there was a 27 percent chance that zero whales would be struck by Navy vessels over the remaining period of the rule (which, at the time that the application was submitted, was 4 years), and a 35, 23, and 10 percent chance that one, two, or three whales, respectively, would be struck over the remaining 4 years of the rule. Therefore, the Navy estimated that there was some probability that the Navy could strike, and take by serious injury or mortality, up to three large whales incidental to training and testing E:\FR\FM\03OCP2.SGM 03OCP2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules activities within the HSTT Study Area over what would have been the remaining 4 years of the current authorization, and the Navy requested authorization of two additional takes of large whales by serious injury or mortality by vessel strike, beyond the three takes authorized by the 2020 HSTT final rule (85 FR 41780, July 10, 2020). NMFS has since updated this analysis to reflect that an additional strike of an unidentified large whale occurred in May 2023 (either a fin whale or sei whale, as stated above) and that additional time has passed since the Navy submitted the 2022 Navy application. Based on further discussions with the Navy, NMFS has also updated the way it calculated at-sea days. This is a different manner of calculating at-sea days for the purposes of the strike analysis rather than a change in Navy’s activity levels. For 2010–2015, the at-sea days used in NMFS’ calculation reflected historic atsea days in the HSTT action area based on positional vessel data records (Mintz, 2016). While the actual annual at-sea days from 2016-present are currently classified, NMFS’ updated calculation reflects an extrapolation of the 2010– 2015 at-sea days (using the formula y = ¥64x + 131555) to estimate the number of at-sea days in 2016 (Navy, 2022). The number of at-sea days derived for 2016 68317 was 2,056 at-sea days, which reflects the downward trend in HSTT vessel activity from 2010–2015. Since we do not have sufficient information to say whether or not this downward trend continued for the years 2017–2022, we conservatively estimate the average over these years was the same as the 2016 extrapolated value of 2,056 at-sea days. This analysis only included at-sea days for Navy warships greater than 65 feet (i.e., destroyers are the smallest ship class included). Navy vessels smaller than 65 feet have never reported a whale strike in the Pacific, and therefore, we consider it unlikely that this would occur in the remaining 2.5 years of the regulations. TABLE 4—HSTT 2009 THROUGH MID-2023 AT-SEA DAYS USED FOR THE VESSEL STRIKE PROBABILITY CALCULATION Year ddrumheller on DSK120RN23PROD with PROPOSALS2 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 At-sea days Derivation .......................................... .......................................... .......................................... .......................................... .......................................... .......................................... .......................................... .......................................... .......................................... .......................................... .......................................... .......................................... .......................................... .......................................... (first half of year) ............. 4,233 5,207 4,483 4,081 4,041 4,272 3,311 2,056 2,056 2,056 2,056 2,056 2,056 2,056 1,028 2009–Mid-2023 total .......... 45,048 NMFS then used the number of past Navy vessel strikes and the at-sea days to calculate a vessel strike rate for 2009 through mid-2023. The estimated total number of Navy at-sea days (for vessels greater than 65 feet) for 2009 through mid-2023 was 45,048 days. Dividing the five known strikes during that period by the at-sea days (i.e., 5 strikes/45,048 atsea days) results in a strike rate of 0.000111 strikes per day. As described above, NMFS conservatively assumed that the average number of at-sea days from mid-2023 through 2025 (the remaining period of the regulations) will be the same as the 2016 extrapolated value of 2,056. Therefore, the estimated at-sea days within the action area for the period from mid-2023 through 2025 is 5,140 days. NMFS multiplied the historic daily strike rate by the estimated at-sea days from mid-2023 through 2025 (0.000111 strikes per day × 5,140 days) to estimate the number of whale strikes anticipated during that period. This calculation predicts an estimated 0.57 strikes over the remaining 2.5 years of VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 Estimated average based on 2010–2015 data. Based on positional vessel data. Based on positional vessel data. Based on positional vessel data. Based on positional vessel data. Based on positional vessel data. Based on positional vessel data. Extrapolated from 2010–2015 regression. Extrapolated from 2010–2015 regression. Extrapolated from 2010–2015 regression. Extrapolated from 2010–2015 regression. Extrapolated from 2010–2015 regression. Extrapolated from 2010–2015 regression. Extrapolated from 2010–2015 regression. Extrapolated from 2010–2015 regression, then reduced by half. the regulations (mid-2023 through 2025). As explained above, according to the U.S. Navy, the May 2021 vessel strike of two fin whales by a Royal Australian Navy vessel did not occur while that vessel was participating in a U.S. Navyled training exercise, and the strike of those two fin whales is not included in the estimated take by vessel strike calculation. Instead, as noted below, NMFS considered the 2021 vessel strike by the Royal Australian Navy along with other strike information when determining which species could be among the estimated large whales struck. NMFS used a Poisson distribution to derive the probabilities of a specific number of strikes (n=0, 1, 2, etc.) from mid-2023 through 2025, given the estimated 0.57 strikes during that period. NMFS’ probability analysis concluded that there is a 57 percent chance that zero whales would be struck by U.S. Navy vessels over the remaining period of the rule (mid-2023 through 2025), and a 32, 9, and 2 percent chance PO 00000 Frm 00029 Fmt 4701 Sfmt 4702 that one, two, or three whales, respectively, would be struck over the remaining 2.5 years of the regulations. Further, there is an estimated 11 percent chance that the Navy would strike more than one large whale over the remaining period of the rule (mid-2023 through 2025). We have assessed these probabilities and determined that the strike up to two large whales could occur over the remaining duration of the regulations, for a total of five takes by serious injury or mortality of large whales by vessel strike total over the 7year duration of the regulations (three takes authorized in the 2020 HSTT final rule (85 FR 41780, July 10, 2020) which have occurred, plus two additional takes). In addition to the reasons listed above that make it unlikely that the Navy will hit a large whale (more maneuverable ships, larger crew, etc.), vessel strike of dolphins, small whales, porpoises, and pinnipeds is considered very unlikely. Dating back more than 20 years and for as long as it has kept records, the Navy has no records of any small whales or E:\FR\FM\03OCP2.SGM 03OCP2 68318 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules pinnipeds being struck by a vessel as a result of Navy activities. Over the same time period, NMFS and the Navy have only one record of a dolphin being struck by a vessel as a result of Navy activities. The dolphin was accidentally struck by a Navy small boat in fall 2021 in Saint Andrew’s Pass, Florida. The smaller size and maneuverability of dolphins, small whales, and pinnipeds generally make such strikes very unlikely. Other than this one reported strike of a dolphin in 2021, NMFS has never received any reports from other LOA or Incidental Harassment Authorization holders indicating that these species have been struck by vessels. In addition, worldwide vessel strike records show little evidence of strikes of these groups from the shipping sector and larger vessels, and the majority of the Navy’s activities involving faster-moving vessels (that could be considered more likely to hit a marine mammal) are located in offshore areas where smaller delphinid, porpoise, and pinniped densities are lower. Based on this information, NMFS concurs with the Navy’s assessment and recognizes the potential for (and is proposing for authorization) incidental take by vessel strike of large whales only (i.e., no dolphins, small whales, porpoises, or pinnipeds) over the course of the 7-year regulations from training and testing activities as discussed below. Next, after determining that take of up to five large whales could occur, NMFS considered which species could be among the five large whales struck. As noted in the 2018 HSTT proposed and final rules, the 2019 HSTT proposed rule, and 2020 HSTT final rule, in the 2017 Navy rulemaking/LOA application, the Navy initially considered a weight of evidence approach that considered relative abundance, historical strike data over many years, and the overlap of Navy activities with the stock distribution in their request. NMFS updated this analysis to consider several factors, in addition to the overlap of Navy activities with stock distribution: (1) The relative likelihood of striking one stock versus another based on available strike data from all vessel types as denoted in the Carretta et al. (2021; referenced in the Pacific SARs), the Pacific and Alaska SARs (Carretta et al. 2023 and Young et al. 2023), and unpublished NMFS vessel strike data for 2019–2021; and (2) whether the Navy has ever struck an individual from a particular species or stock in the HSTT Study Area, and if so, how many times. NMFS did not consider relative abundance, as was considered in previous analyses, given that the relative abundance of a stock does not necessarily inform its occurrence in a specific area. Further, NMFS did not consider the historical strike data from older years (prior to 2015), given that more recent data is more relevant to determining occurrence of, and strike risk to, various stocks. NMFS updated the analysis with NMFS’ vessel strike probability analysis for the remaining 2.5 years of the rule and included new/ updated vessel strike data from the SARs and NMFS records for California and Hawaii. To address number (1) above, for SOCAL, NMFS compiled information from Carretta et al. (2021) and unpublished NMFS vessel strike data for 2020–2021 for California on known annual rates of large whale serious injury or mortality from vessel collisions (this data includes the strike of 2 fin whales by the Royal Australian Navy in 2021, but does not include Navy strikes in 2021 and 2023 because the species struck is not known). Use of Carretta et al. (2021) rather than the Pacific SAR allows NMFS to separate strikes that occurred in California from strikes to the same stocks that occurred in other locations. For the HRC, NMFS compiled information from the Pacific and Alaska SARs and unpublished NMFS vessel strike data for 2019–2021 for Hawaii on known annual rates of large whale serious injury or mortality from vessel collisions. The annual rates of large whale serious injury or mortality from vessel collisions from those sources help inform the relative susceptibility of large whale species to vessel strike in SOCAL and the HRC; therefore, we considered only reported strikes where the species struck was identified with sufficient certainty (i.e., ‘‘known strikes’’). Additionally, the M/ SI in the 2022 SAR considers modeled takes for some, but not most species and stocks (i.e., M/SI for humpback whale includes modeled takes from Rockwood et al. (2017)). Using known strike data for all species and stocks allows us to consider-like metrics for this comparative analysis. (Note we rely on the M/SI estimates from the 2022 SAR in our Negligible Impact Analysis. We also consider modeled takes of species from Rockwood et al. (2017) in table 7). We summed the annual rates of serious injury or mortality from vessel collisions in California and Hawaii as calculated above and then divided each species’ annual rate by this sum to get the proportion of strikes for each species/stock (table 5). TABLE 5—ANNUAL RATES OF SERIOUS INJURY AND MORTALITY FROM VESSEL STRIKE AND PERCENTAGE OF TOTAL STRIKES BY SPECIES IN SOCAL AND THE HRC ESA status Species Stock Listed .............. Blue whale .......................... Central North Pacific ................................. Eastern North Pacific ................................ California, Oregon, & Washington ............ Hawaiian .................................................... Central America/Southern Mexico-CA/OR/ WA (Central America DPS). Mainland Mexico-CA/OR/WA (Mexico DPS). Eastern North Pacific ................................ Hawaiian .................................................... Western North Pacific ............................... California, Oregon, & Washington ............ Hawaiian .................................................... Eastern North Pacific ................................ ETP stock .................................................. Hawaiian .................................................... CA/OR/WA ................................................ Fin whale a .......................... ddrumheller on DSK120RN23PROD with PROPOSALS2 Humpback whale ................ Sei whale ............................ Gray whale .......................... Sperm whale ....................... Not listed ........ Gray whale .......................... Bryde’s whale ..................... Minke whale ........................ VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 PO 00000 Frm 00030 Fmt 4701 Sfmt 4702 SOCAL annual known strikes (2015–2021) HRC annual known strikes (2015–2021) ........................ 0.57 1.57 ........................ b1 0 ........................ ........................ 0 ........................ 0.0 6.5 17.8 0.0 11.3 0.14 ........................ 0 0 ........................ 2.14 0 ........................ 0 ........................ 0 ........................ ........................ 0 ........................ ........................ 0 ........................ 1.6 0.0 0.0 0.0 0.0 24.3 0.0 0.0 0.0 E:\FR\FM\03OCP2.SGM 03OCP2 Percentage of total annual strikes 68319 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules TABLE 5—ANNUAL RATES OF SERIOUS INJURY AND MORTALITY FROM VESSEL STRIKE AND PERCENTAGE OF TOTAL STRIKES BY SPECIES IN SOCAL AND THE HRC—Continued Species Stock SOCAL annual known strikes (2015–2021) HRC annual known strikes (2015–2021) Humpback whale ................ Hawaiian .................................................... Hawaii (Hawaii DPS) ................................. ........................ ........................ 0 3.4 ............................................. .................................................................... ESA status Total ........ 8.82 Percentage of total annual strikes 0.0 38.5 ............................ a This includes the two fin whales struck by the Royal Australian Navy in May 2021. strike occurred to an individual of the CA/OR/WA stock under the previous stock structure. As such, in its analysis, NMFS assumed that this strike could have been of either stock. b This To inform the likelihood of striking a particular species of large whale, we multiplied the percent of total annual strikes for a given species in table 5, by the total percent likelihood of striking at least one whale during the remaining period of the rule (2023–2025; i.e., 43 percent, as described by the probability analysis above). We also calculated the percent likelihood of striking a particular species of large whale twice during the remaining period of the rule by squaring the value estimated for the probability of striking a particular species of whale once (i.e., to calculate the probability of an event occurring twice, multiply the probability of the first event by the second). The results of these calculations are reflected in the last two columns of table 6. We note that these probabilities vary from year to year as the average annual mortality changes depending on the specific range of time considered; however, over the years and through updated data in the SARs and unpublished NMFS records, stocks tend to consistently maintain a relatively higher or relatively lower likelihood of being struck. TABLE 6—PERCENT LIKELIHOOD OF STRIKING EACH STOCK ONE OR TWO TIMES OVER 2.5 YEARS AND TOTAL KNOWN U.S. NAVY STRIKES IN THE HSTT STUDY AREA Total known U.S. Navy strikes in HSTT study area Species Stock Blue whale ...................................... Central North Pacific ...................... Eastern North Pacific ..................... CA/OR/WA ..................................... Hawaiian ........................................ Central America/Southern MexicoCA/OR/WA (Central America DPS). Mainland Mexico-CA/OR/WA (Mexico DPS). Eastern North Pacific ..................... Hawaiian ........................................ Western North Pacific .................... CA/OR/WA ..................................... Hawaiian ........................................ Eastern North Pacific ..................... ETP stock ....................................... Hawaiian ........................................ CA/OR/WA ..................................... Hawaii ............................................ Hawaii (Hawaii DPS) ..................... Fin whale ........................................ Humpback whale ............................ Sei whale ........................................ Gray whale ..................................... Sperm whale ................................... Gray whale ..................................... Bryde’s whale ................................. Minke whale .................................... Humpback whale ............................ 0 1 3 0 0 Percent likelihood of 1 strike over 2.5 years Percent likelihood of 2 strikes over 2.5 years ..................................................... in SOCAL (2004) ........................ in SOCAL (2009, 2023 a) ............ ..................................................... ..................................................... 0.00 2.81 b 7.74 0.00 4.93 0.00 0.08 b 0.60 0.00 0.24 1 in SOCAL (2023 a) ...................... 0 ..................................................... 0 ..................................................... 0.00 ................................................ 1 in HRC (2007) ............................. 3 in SOCAL (1993, 1998) .............. 0 ..................................................... 0 ..................................................... 0 ..................................................... 0 ..................................................... 2 in HRC (2003) ............................. 0.69 0.00 0.00 0.00 0.00 10.55 0.00 0.00 0.00 0.00 16.76 0.00 0.00 0.00 0.00 1.11 0.00 0.00 0.00 0.00 2.81 ddrumheller on DSK120RN23PROD with PROPOSALS2 a Based on available photos and video, NMFS and the Navy have determined the May 2023 strike was of either a fin whale or sei whale. In the analysis herein, NMFS has assumed that this strike could have been of either species, and has therefore, accounted for it in both the fin whale and sei whale strike totals. Given that we are unable to identify the species of the whales struck by the U.S. Navy in 2021, NMFS did not include the two 2021 strikes in this part of the analysis. b This includes the two fin whales struck by the Royal Australian Navy in May 2021. The percent likelihood calculated as described above are then considered in combination with the information indicating the known species that the Navy has hit in the HSTT Study Area since 1991 (since they started tracking consistently; table 6). We note that for the lethal take of species specifically denoted in table 7 below, 47 percent of those struck by the Navy (8 of 17 in the VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 Pacific) remained unidentified (including the May 2023 strike, which as stated above, NMFS and the Navy have determined was of either a fin whale or sei whale). However, given the information on known stocks struck, the analysis below remains appropriate. We also note that Rockwood et al. (2017) modeled the likelihood of vessel strike of blue whales, fin whales, and PO 00000 Frm 00031 Fmt 4701 Sfmt 4702 humpback whales on the U.S. West Coast (discussed in more detail in the Serious Injury or Mortality subsection of the Preliminary Analysis and Negligible Impact Determination section), and those numbers help inform the relative likelihood that the Navy could hit those stocks. For each indicated stock, table 7 includes the percent likelihood of E:\FR\FM\03OCP2.SGM 03OCP2 68320 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules striking an individual whale from a particular stock during the remaining 2.5 years of the rule once based on SAR data, Carretta et al. (2021), and unpublished NMFS vessel strike data from 2019–2021 for Hawaii; total strikes from Navy vessels in the HSTT Study Area, and modeled vessel strikes from Rockwood et al. (2017). The last column indicates the annual mortality proposed to be authorized. TABLE 7—SUMMARY OF FACTORS CONSIDERED IN DETERMINING THE NUMBER OF INDIVIDUALS IN EACH STOCK POTENTIALLY STRUCK BY A VESSEL Percent likelihood of one strike over 2.5 years ESA status Species Stock Listed ............. Blue whale .......................... Central North Pacific .......... Eastern North Pacific .......... CA/OR/WA .......................... Hawaii ................................. Central America/Southern Mexico-CA/OR/WA (Central America DPS). Mainland Mexico-CA/OR/ WA (Mexico DPS). Eastern North Pacific .......... Hawaii ................................. Western North Pacific ......... CA/OR/WA .......................... Hawaii ................................. Eastern North Pacific .......... Eastern Tropical Pacific ...... Hawaii ................................. CA/OR/WA .......................... Hawaii ................................. Hawaii (Hawaii DPS) 5 ........ Fin whale ............................ Humpback whale 4 .............. Sei whale ............................ Gray whale ......................... Sperm whale ....................... Not listed ....... Gray whale ......................... Bryde’s whale ..................... Minke whale ........................ Humpback whale ................ 0.00 2.81 2 7.74 0.00 4.93 Total known U.S. Navy strikes in HSTT study area (1993–2009) 0 1 3 0 0 .......................................... in SOCAL (2004) ............. in SOCAL (2009, 2023 3) .......................................... .......................................... Rockwood et al. 2017 modeled vessel strikes 1 Annual authorized take from 2020 HSTT final rule .................... 18 43 .................... 22 .................... 0.14 0.29 .................... 0.14 Proposed annual authorized take 0 0.14 0.57 0 0 0.14 0.69 0.00 0.00 0.00 0.00 10.55 0.00 0.00 0.00 0.00 16.76 1 0 0 0 1 3 0 0 0 0 2 SOCAL(2023) 3 in ............ .......................................... .......................................... .......................................... in HRC (2007) ................. in SOCAL (1993, 1998) ... .......................................... .......................................... .......................................... .......................................... in HRC (2003) ................. .................... .................... .................... .................... .................... .................... .................... .................... .................... .................... .................... .................... .................... .................... .................... 0.14 0.29 .................... .................... .................... .................... 0.29 0.14 0 0 0 0 0.57 0 0 0 0 0.29 1 Rockwood ddrumheller on DSK120RN23PROD with PROPOSALS2 et al. modeled likely annual vessel strikes off the West Coast for these three species only. 2 This includes the two fin whales struck by the Royal Australian Navy in May 2021. 3 Based on available photos and video, NMFS and the Navy have determined the May 2023 strike was of either a fin whale or sei whale. In the analysis herein, NMFS has assumed that this strike could have been of either species, and has therefore, accounted for it in both the fin whale and sei whale strike totals. 4 In the 2020 HSTT final rule, take of humpback whale by serious injury and mortality by vessel strike in Southern California was attributed to the former CA/OR/WA stock and the Mexico DPS. Text explains why takes in SOCAL come from the Mexico DPS, and therefore the Mainland Mexico-CA/OR/WA stock. 5 The 2022 final SAR reports vessel strike data for the Hawaii stock of humpback whales in Alaska, Washington, and Hawaii. Only vessel strike data from Hawaii was incorporated into our analysis as Alaska and Washington are outside of the HSTT Study Area. Accordingly, stocks that have no record of ever having been struck by any vessel are considered to have a zero percent likelihood of being struck by the Navy in the 7-year period of the rule. Stocks that have never been struck by the Navy, have rarely been struck by other vessels, and have a low percent likelihood based on the historical vessel strike calculation are also considered to have a zero percent likelihood to be struck by the Navy during the 7-year rule. We note that while vessel strike records have not differentiated between Eastern North Pacific and Western North Pacific gray whales, given their small population size and the comparative rarity with which individuals from the Western North Pacific stock are detected off the U.S. West Coast, it is highly unlikely that they would be encountered, much less struck. This rules out all but seven stocks. Further, it is unlikely that the Hawaii stock of sperm whale would be struck given the zero percent likelihood of striking a sperm whale as indicated by the quantitative analysis above, the fact that the last U.S. Navy strike of a Hawaii stock sperm whale was in 2007, before the mitigation updates discussed above, and that, with the exception of VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 humpback whales, vessel strikes (both military and non-military) of other large whale species in the HRC are extremely rare events (Carretta 2021b; Carretta 2022). (The 2020 HSTT final rule authorized 1 take (0.14 annual take) by mortality of the Hawaii stock of sperm whale.) As stated previously, based on available photos and video of the whale struck by the U.S. Navy in Southern California in 2023, NMFS and the Navy have determined this whale was either a fin whale or sei whale. While the species of the two whales struck by the U.S. Navy in 2021 are unknown, given the following factors, NMFS expects these strikes may have been CA/OR/WA fin whales or Eastern North Pacific (ENP) gray whales, or some combination of these two stocks. These species have the highest annual rates of mortality/ serious injury (M/SI) from vessel collision in California (1.57, 2.14, respectively, as noted above; which is approximately one and a half to two times higher than the species with the next highest strike rate, humpback whale, and approximately two to four times higher than the strike rate of blue whale). Additionally, gray whale and fin whale have the most recorded vessel PO 00000 Frm 00032 Fmt 4701 Sfmt 4702 strike incidents by military vessels in SOCAL and are the only stocks known to have been hit more than one time by naval vessels in the SOCAL portion of the HSTT Study Area (3 gray whale strikes by the U.S. Navy (1993, 1998), 2 or 3 fin whale strikes by the U.S. Navy (2009, potentially 2023), and 2 fin whale strikes by the Royal Australian Navy (2021)). Further, accounting for undocumented vessel strikes, Rockwood et al. (2021) estimated that in their study area off Southern California from 2012– 2018, on average 8.9 blue, 4.6 humpback, and 9.7 fin whales were killed by civilian vessel strikes from June to November each year. In addition, they estimated that, on average, 5.7 humpback whales were killed by civilian vessel strike from January–April per year (Rockwood et al. 2021). For fin whales in particular, model-predicted densities of large whales in the Southern California Bight from May to July 2021 (the time period during which the 2021 strikes of two unidentified whales by the U.S. Navy occurred) estimated fin whale abundance as being nearly an order of magnitude higher than either blue or humpback whale abundance during this time period (Becker et al. 2020; Zickel E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules et al. 2021). Ship-whale encounter models for the U.S. West Coast Exclusive Economic Zone also indicated that vessel strike mortality estimates for fin whales were significantly higher than for blue whales and humpback whales (Rockwood et al. 2017). The comparatively higher modeled vessel strike rates for fin whales result from both the larger population as well as the more offshore distribution that overlaps significantly with several major shipping routes for a much greater spatial extent (Rockwood et al. 2017). Based on 1,243 visual boat-based sightings of 2,638 fin whales from 1991– 2011, Calambokidis et al. (2015) found fin whale concentration areas included the San Clemente Basin where the 2021 Navy vessel strikes occurred (Tanner and Cortez Banks area and the shelf edge west of San Nicolas Island were also reported as fin whale concentration areas). There are two different populations of fin whales that occur in the Southern California Bight: a seasonal population, and a population that occurs year-round with offshore/ inshore movements (Campbell et al. 2015; Falcone et al. 2022). This would likely make fin whales more susceptible to vessel strike year-round, as compared to other large whale species that may occur seasonally within SOCAL. Based on all of these factors, there is a reasonable likelihood that the CA/OR/ WA stock of fin whales or ENP stock of gray whales could be struck twice during the remaining 2.5 years of the rule. Therefore, we propose that, of the five total takes by serious injury or mortality by vessel strike of large whales proposed to be authorized, up to four of those takes could be of the CA/OR/WA stock of fin whale or the ENP stock of gray whale given that the two strikes of unidentified large whales in 2021 could have been of either stock. Further, consistent with the 2020 HSTT final rule, we propose that, of the five total takes by serious injury or mortality by vessel strike of large whales proposed to be authorized, up to two of those takes could occur in Hawaii, and therefore be of individuals of the Hawaii stock of humpback whale. Based on the information summarized in table 7 and the fact that there is the potential for up to two large whales to be struck over the remaining 2.5 years of the rule (five strikes over the full 7year rule period), one individual from the Eastern North Pacific stock of blue whale, Mainland Mexico-CA/OR/WA stock of humpback whale, or Eastern North Pacific stock of sei whale could be among the two whales struck during the remaining effective period of the VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 regulations (2023–2025). The total strikes of Eastern North Pacific blue whales and the percent likelihood of striking one based on the historic strike calculation above can both be considered moderate compared to other stocks, and the Navy struck a blue whale in 2004 (based on the historic strike calculation, the likelihood of striking two blue whales is well below one percent (table 6)). Therefore, we consider it reasonably likely that the Navy could strike one individual over the course of the 7-year rule, and given that we do not expect that the 2023 strike nor either of the 2021 U.S. Navy strikes of unidentified large whales were blue whales, we expect that this strike could occur during the remaining 2.5 years of the rule. The total strikes of Eastern North Pacific sei whales are low compared to other stocks, but NMFS and the Navy think it is possible that the Navy may have struck a sei whale in SOCAL in 2023. Therefore, we consider it reasonably likely that the Navy could strike a sei whale over the remaining 2.5 years of the rule. The Navy has not hit a humpback whale in the SOCAL portion of the HSTT Study Area. However, in 2016 a U.S. Coast Guard vessel participating in a Navy event struck a humpback whale in Hood Canal, and as a species, humpbacks have a moderate to high number of total strikes and percent likelihood of being struck. Although the likelihood of Central America/Southern Mexico-CA/ OR/WA (Central America DPS) or Mainland Mexico-CA/OR/WA (Mexico DPS) humpback whales being struck by any vessel type is moderate to high relative to other stocks, the distribution of the Mexico DPS versus the Central America DPS, as well as the distribution of overall vessel strikes inside versus outside of the SOCAL area (the majority are outside), supports the reasonable likelihood that the Navy could strike one individual humpback whale from the Mainland Mexico-CA/OR/WA stock (Mexico DPS) over the 7-year duration of the rule, as described below. Regarding the likelihood of striking a humpback whale from a particular DPS, we evaluated the relative abundance of each of these DPS in California waters. Curtis et al. (2022) estimated the abundance of the Central America DPS to be 1,496 whales. From Wade et al. (2017), about 93 percent (or 1,391 whales) of these humpbacks that winter in Central America will move to Oregon/California in the summer months. While there is currently no abundance estimate for the Mexico DPS, an estimated 3,477 whales from the Mexico DPS feed off the U.S. West Coast PO 00000 Frm 00033 Fmt 4701 Sfmt 4702 68321 (Calambokidis and Barlow 2020; Curtis 2022). Based on this information, we estimate that approximately 30 percent of the humpback whales off the coast of California may be from the Central America DPS with the remaining 70 percent are expected to be from the Mexico DPS. Therefore, we anticipate that if a Navy vessel strike of a humpback whale were to occur within SOCAL, it would likely be from the Mexico DPS. Last, Rockwood et al. (2017) supports a relative likelihood of 1:1:2 for striking blue whales, humpback whales, and fin whales off the U.S West Coast (though as noted above, more recent data suggests that the relative likelihood of striking a fin whale is higher and suggests that the two 2021 U.S. Navy vessel strikes of unidentified large whales may have been fin whales), which, in consideration of more recent data also supports the proposed authorized take included in this rule, which is 1, 1, and 4, respectively over the 7-year period. For these reasons, one lethal take of a Mainland Mexico-CA/OR/WA humpback whale (Mexico DPS) could occur and is proposed for authorization. For Hawaii stocks, given that all known vessel strikes between 2015 and 2021 were of humpback whales, we anticipate that any vessel strike of a large whale in Hawaii would be of the Hawaii stock of humpback whale. Given that this stock has the highest percentage of total annual strikes (38.5 percent) and a 2.81 percent chance of being struck twice over the remaining 2.5 years (more than twice that of the species with the next highest percentage, gray whale), NMFS proposes to authorize two lethal takes of Hawaii humpback whales. As described above, the Navy’s analysis suggests and NMFS’ analysis concurs that the likelihood of vessel strikes to the stocks below is discountable due to the stocks’ relatively low occurrence in the HSTT Study Area, particularly in core HSTT training and testing subareas, and the fact that the stocks have not been struck by the Navy and are rarely, if ever, recorded struck by other vessels. Therefore, NMFS is not proposing to authorize lethal take for the following stocks: Blue whale (Central North Pacific stock), Bryde’s whale (Eastern Tropical Pacific stock and Hawaii stock), fin whale (Hawaii stock), gray whale (Western North Pacific stock), humpback whale (Central America/ Southern Mexico-CA/OR/WA stock, Central America DPS), minke whale (CA/OR/WA stock and Hawaii stock), sei whale (Hawaii stock), and sperm E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68322 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules whale (CA/OR/WA stock and Hawaii stock). Also of note, while information on past Navy vessel strikes can serve as a reasonable indicator of future vessel strike risk, future conditions may differ from the past in ways that could influence the likelihood of a large whale vessel strike occurring. In general, the magnitude of vessel strike risk may be increasing over time as many whale populations are gradually recovering from centuries of commercial whaling (Redfern et al. 2020). Increased vessel strike risk off California in recent decades has been associated with increases in the abundance of fin and humpback whale populations in the North Pacific (Redfern et al. 2020). It has also been suggested that the blue whale population in the Eastern North Pacific, inclusive of the SOCAL portion of the action area, is at carrying capacity and recovered to pre-whaling levels (Monnahan et al. 2014). In addition, the magnitude of risk may also be affected by shifts in whale distributions over time in response to environmental factors including climate change, marine heatwaves, and associated changes in prey distribution. Historically, military vessel strikes of large whales within the HSTT Study Area have been rare events with only seven such strikes occurring over the past 14 years, five U.S. Navy strikes, and two Royal Australian Navy strikes. However, the fact that four of these strikes occurred within a 3-month period (May–July) in 2021, and two occurred within a 4-month period (February–May) in 2009, suggests that military vessel strikes in SOCAL can be both highly episodic and clustered. The four large whale strikes in 2021 (two strikes of unidentified large whales by the U.S. Navy and two fin whale strikes by the Royal Australian Navy) appear to be outliers in the time series of military vessel strikes in SOCAL for that period. However, particularly in consideration of the 2023 U.S. Navy strike, these strikes could also represent an early indicator of an increased military vessel strike risk within SOCAL based on the factors discussed above. Results from a survey of whale watching vessel operators and crew in Southern California, combined with remote sensing data in the area, suggest that the number of large whales may have been greater in May through July of 2021 compared with previous years in certain high military vessel traffic and ‘‘core’’ use HSTT areas off southern California, particularly farther offshore as well as closer to shore off San Diego Bay (Zickel MJ et al. 2021). VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 In conclusion, while take by vessel strike across any given year is sporadic, based on the information and analysis above, including consideration of the 2021 and 2023 strikes by the U.S. Navy, NMFS anticipates no more than five takes of large whales by M/SI could occur over the 7-year period of the rule. Of those five whales over the 7-years, no more than four may come from the following stocks: gray whale (Eastern North Pacific stock) and fin whale (CA/ OR/WA stock). No more than two may come from the Hawaii stock of humpback whales. No more than one may come from the following stocks: blue whale (Eastern North Pacific stock), sei whale (Eastern North Pacific), and humpback whale (Mexico-North Pacific stock or Mainland Mexico-CA/OR/WA, Mexico DPS). Accordingly, NMFS has evaluated under the negligible impact standard the M/SI of 0.14, 0.29, or 0.57 whales annually from each of these species or stocks (i.e., 1, 2, or 4 takes, respectively, divided by 7 years to get the annual number), along with the expected incidental takes by harassment. Explosives The Navy’s model and quantitative analysis process used for the 2018 HSTT FEIS/OEIS and in the Navy’s 2017 and 2019 applications to estimate potential exposures of marine mammals to explosive stressors is detailed in the technical report titled Quantifying Acoustic Impacts on Marine Mammals and Sea Turtles: Methods and Analytical Approach for Phase III Training and Testing report (U.S. Department of the Navy, 2018). Specifically, over the course of a modeled maximum year of training and testing, the Navy’s model and quantitative analysis process estimates M/SI of two short-beaked common dolphin and one California sea lion as a result of exposure to explosive training and testing activities (please see section 6 of the 2017 Navy application where it is explained how maximum annual estimates are calculated). Over the 7-year period of the 2020 HSTT regulations, M/SI of 8 short-beaked common dolphins and 5 California sea lions (13 marine mammals in total) is estimated as a result of exposure to explosive training and testing activities. NMFS proposes no changes to the authorization of take by M/SI as a result of explosive use as the Navy proposes no changes to its activities from that described in the 2018 HSTT final rule, and after reviewing all new information, we find that our previous analyses remain applicable. Please refer to the PO 00000 Frm 00034 Fmt 4701 Sfmt 4702 2018 HSTT final rule and 2020 HSTT final rule for additional information. Proposed Mitigation Measures Under section 101(a)(5)(A) of the MMPA, NMFS must set forth the permissible methods of taking pursuant to the activity, and other means of effecting the least practicable adverse impact on the species or stock(s) and its habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance, and on the availability of the species or stock(s) for subsistence uses (‘‘least practicable adverse impact’’). NMFS does not have a regulatory definition for least practicable adverse impact. The 2004 NDAA amended the MMPA as it relates to military readiness activities and the incidental take authorization process such that a determination of ‘‘least practicable adverse impact’’ shall include consideration of personnel safety, practicality of implementation, and impact on the effectiveness of the military readiness activity. For the full discussion of how NMFS interprets least practicable adverse impact, including how it relates to the negligible-impact standard, see the Mitigation Measures section in the 2018 HSTT final rule. Section 101(a)(5)(A)(i)(II) requires NMFS to issue, in conjunction with its authorization, binding—and enforceable—restrictions (in the form of regulations) setting forth how the activity must be conducted, thus ensuring the activity has the ‘‘least practicable adverse impact’’ on the affected species or stocks. In situations where mitigation is specifically needed to reach a negligible impact determination, section 101(a)(5)(A)(i)(II) also provides a mechanism for ensuring compliance with the ‘‘negligible impact’’ requirement. Finally, the least practicable adverse impact standard also requires consideration of measures for marine mammal habitat, with particular attention to rookeries, mating grounds, and other areas of similar significance, and for subsistence impacts, whereas the negligible impact standard is concerned solely with conclusions about the impact of an activity on annual rates of recruitment and survival.1 In evaluating what mitigation measures are appropriate, NMFS considers the potential impacts of the Specified Activities, the availability of measures to minimize those potential impacts, and the practicability of implementing those measures, as we 1 Outside of the military readiness context, mitigation may also be appropriate to ensure compliance with the ‘‘small numbers’’ language in MMPA sections 101(a)(5)(A) and (D). E:\FR\FM\03OCP2.SGM 03OCP2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules ddrumheller on DSK120RN23PROD with PROPOSALS2 describe below. This proposed rule includes all mitigation measures required by the 2020 HSTT final rule (though two have been modified in this proposed rule), and our discussion in that rule remains complete and accurate (including reference to the 2018 HSTT final rule), except as described below. Implementation of Least Practicable Adverse Impact Standard Our evaluation of potential mitigation measures includes consideration of two primary factors: (1) The manner in which, and the degree to which, implementation of the potential measure(s) is expected to reduce adverse impacts to marine mammal species or stocks, their habitat, and their availability for subsistence uses (where relevant). This analysis considers such things as the nature of the potential adverse impact (such as likelihood, scope, and range), the likelihood that the measure will be effective if implemented, and the likelihood of successful implementation; and (2) The practicability of the measure(s) for applicant implementation. Practicability of implementation may consider such things as cost, impact on activities, and, in the case of a military readiness activity, specifically considers personnel safety, practicality of implementation, and impact on the effectiveness of the military readiness activity. While the language of the least practicable adverse impact standard calls for minimizing impacts to affected species or stocks, we recognize that the reduction of impacts to those species or stocks accrues through the application of mitigation measures that limit impacts to individual animals. Accordingly, NMFS’ analysis focuses on measures that are designed to avoid or minimize impacts on individual marine mammals that are likely to increase the probability or severity of populationlevel effects. While direct evidence of impacts to species or stocks from a specified activity is rarely available, and additional study is still needed to understand how specific disturbance events affect the fitness of individuals of certain species, there have been improvements in understanding the process by which disturbance effects are translated to the population. With recent scientific advancements (both marine mammal energetic research and the development of energetic frameworks), the relative likelihood or degree of impacts on species or stocks may often be inferred given a detailed VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 understanding of the activity, the environment, and the affected species or stocks—and the best available science has been used here. This same information is used in the development of mitigation measures and helps us understand how mitigation measures contribute to lessening effects (or the risk thereof) to species or stocks. We also acknowledge that there is always the potential that new information, or a new recommendation could become available in the future and necessitate reevaluation of mitigation measures (which may be addressed through adaptive management) to see if further reductions of population impacts are possible and practicable. In the evaluation of specific measures, the details of the specified activity will necessarily inform each of the two primary factors discussed above (expected reduction of impacts and practicability), and are carefully considered to determine the types of mitigation that are appropriate under the least practicable adverse impact standard. Analysis of how a potential mitigation measure may reduce adverse impacts on a marine mammal stock or species, consideration of personnel safety, practicality of implementation, and consideration of the impact on effectiveness of military readiness activities are not issues that can be meaningfully evaluated through a yes/ no lens. The manner in which, and the degree to which, implementation of a measure is expected to reduce impacts, as well as its practicability in terms of these considerations, can vary widely. For example, a time/area restriction could be of very high value for decreasing population-level impacts (e.g., avoiding disturbance of feeding females in an area of established biological importance) or it could be of lower value (e.g., decreased disturbance in an area of high productivity but of less firmly established biological importance). Regarding practicability, a measure might involve restrictions in an area or time that impede the Navy’s ability to certify a strike group (higher impact on mission effectiveness), or it could mean delaying a small in-port training event by 30 minutes to avoid exposure of a marine mammal to injurious levels of sound (lower impact). A responsible evaluation of ‘‘least practicable adverse impact’’ will consider the factors along these realistic scales. Accordingly, the greater the likelihood that a measure will contribute to reducing the probability or severity of adverse impacts to the species or stock or its habitat, the greater the weight that measure is given when PO 00000 Frm 00035 Fmt 4701 Sfmt 4702 68323 considered in combination with practicability to determine the appropriateness of the mitigation measure, and vice versa. In the evaluation of specific measures, the details of the specified activity will necessarily inform each of the two primary factors discussed above (expected reduction of impacts and practicability), and will be carefully considered to determine the types of mitigation that are appropriate under the least practicable adverse impact standard. For more detail on how we apply these factors, see the discussion in the Mitigation Measures section of the 2018 HSTT final rule. Assessment of Mitigation Measures for HSTT Rule NMFS fully reviewed the Navy’s specified activities and the mitigation measures for the 2020 HSTT final rule and determined, with the addition of the new and modified measures discussed herein, and after consideration of the new information and studies described above, that the proposed mitigation measures would result in the least practicable adverse impact on marine mammals (see the 2019 Navy application and the 2018 HSTT final rule for detailed information on the Navy’s mitigation measures, with the exception of the new and modified measures described herein). NMFS worked with the Navy in the development of the Navy’s mitigation measures, which were informed by years of implementation and monitoring. A complete discussion of the Navy’s evaluation process used to develop, assess, and select mitigation measures, which was informed by input from NMFS, can be found in Chapter 5 (Mitigation) of the 2018 HSTT FEIS/ OEIS. The process described in Chapter 5 (Mitigation) of the 2018 HSTT FEIS/ OEIS robustly supports NMFS’ independent evaluation of whether the mitigation measures would meet the least practicable adverse impact standard. The Navy has implemented the mitigation measures under the 2020 HSTT regulations and would be required to continue implementation of the mitigation measures identified in this rulemaking for the full 7 years it covers to avoid or reduce potential impacts from acoustic, explosive, and physical disturbance and vessel strike stressors. The Navy also evaluated numerous measures in the 2018 HSTT FEIS/OEIS that were not included in the 2017 Navy application, and NMFS independently reviewed and considered all new information, and continues to concur with Navy’s analysis that their inclusion E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68324 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules was not appropriate under the least practicable adverse impact standard. The Navy considered these additional potential mitigation measures in two groups. First, Chapter 5 (Mitigation) of the 2018 HSTT FEIS/OEIS, in the Measures Considered but Eliminated section, includes an analysis of an array of different types of mitigation that have been recommended over the years by NGOs or the public, through scoping or public comment on environmental compliance documents. Appendix K (Geographic Mitigation Assessment) of the 2018 HSTT FEIS/OEIS includes an in-depth analysis of time/area restrictions that have been recommended over time or previously implemented as a result of litigation. Below, we summarize the mitigation measures (organized into procedural measures and mitigation areas) that NMFS has determined will ensure the least practicable adverse impact on all affected species and stocks and their habitat, including the specific considerations for military readiness activities, and including several measures that are new or modified since publication of the 2020 HSTT final rule. In its 2022 application, the Navy proposed no changes to the procedural or geographic mitigation measures in the 2020 HSTT final rule. NMFS reviewed new information potentially pertinent to mitigation of the Navy’s training and testing activities. While Lookouts are essential to detecting the potential for and potentially avoiding a vessel strike of a marine mammal, NMFS and the Navy have always acknowledged that Lookouts cannot prevent all vessel strikes. The recent U.S. Navy and Royal Australian Navy vessel strikes appear to confirm this, as these strikes occurred when Lookouts were posted. As acknowledged above, these recent incidents may represent an early indicator of an increased military vessel strike risk within SOCAL. Recent reports appear to reflect the sporadic, episodic, or clustered nature of vessel strike or may reflect a trend of increased large whale presence in this area in the early summer months. NMFS and Navy have discussed the circumstances of each of the recent strikes, including the Royal Australian Navy strike, and discussed ways of improving strike mitigation. In these further conversations, NMFS and the Navy developed several new and modified mitigation measures in comparison to those included in the 2020 HSTT final rule. For vessel movement, the 2020 HSTT final rule required that ‘‘When underway Navy personnel must observe the mitigation zone for marine VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 mammals; if marine mammals are observed, Navy personnel must maneuver to maintain distance.’’ This measure has been updated to state that reducing speed may be an appropriate way to maneuver. The revised measure states that ‘‘When underway, Navy personnel must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must maneuver (which may include reducing speed as the mission or circumstances allow) to maintain distance.’’ Of note, between 2009 and 2021 (the most recent year for which data is available), U.S. Navy vessels in the SOCAL portion of the HSTT Study Area maneuvered 316 times to avoid large whales during MTEs. The years 2017 and 2021 had the highest number of maneuvers (n=64 and n=82, respectively). In all years for which data is available (2009 to 2021), Navy cruisers and destroyers account for 51 to 100 percent of maneuvers during MTEs. With this modified measure, NMFS is emphasizing that Navy personnel should consider reducing speed (as mission or circumstances allow) when maneuvering to avoid marine mammals, though this modified measure does not require reduction of vessel speed for reasons explained in Chapter 5 (Mitigation) of the 2018 HSTT FEIS/ OEIS, in the Measures Considered but Eliminated section (i.e., requirements to reduce vessel speeds would have significant direct negative effects on mission effectiveness). This proposed rule also requires that Navy personnel must send alerts to Navy vessels of increased risk of strike following any reported Navy vessel strike in the HSTT Study Area. Further, the 2020 HSTT final rule included a requirement for Navy personnel to issue seasonal awareness notification messages to alert ships and aircraft to the possible presence of blue whales (June–October), humpback whales (November–April), gray whales (November–March), or fin whales (November–May). These messages assist in maintaining safety of navigation and in avoiding interactions with large whales during transits. Platforms must use the information from the awareness notification messages to assist their visual observation of applicable mitigation zones during training and testing activities and to aid in the implementation of procedural mitigation. This proposed rule requires the Navy to re-title the spring blue whale message (released in June) to a large whale awareness message inclusive of typical spring-summer large whales in southern California (mainly blue, fin, and humpback whales). PO 00000 Frm 00036 Fmt 4701 Sfmt 4702 Furthermore, rather than tying the message release to a specific month, the message would be for a period based on predicted oceanographic conditions for a given year (e.g., May–November, April–November, etc.). The Navy will also evaluate information obtained from NMFS’ Southwest Fisheries Science Center scientists, soon to be promulgated revised West Coast BIAs, and other oceanographic or predictive models for guiding message text descriptions of whale occurrence in Southern California. The improvement will emphasize that when a marine mammal is spotted, this may be an indicator that additional marine mammals are present and nearby, and increased vigilance and awareness of Navy personnel is warranted. The proposed rule also contains a new mitigation measure in which Navy personnel would issue real-time notifications to Navy vessels of large whale aggregations (four or more whales) within 1 nmi (1.9 km) of a Navy vessel in a select area of SOCAL (Of note, the four whales do not have to be the same species and do not have to be part of the same group (e.g., two whales of one species sighted at a distance off the port side at 500 yd (457.2 m) and two more whales of another species sighted off the starboard side at 500 yd (457.2 m) would be considered an aggregation under this measure)). This measure would apply to the area between 32–33 degrees North and 117.2–119.5 degrees West, which includes the locations where recent (2009, 2021, 2023) strikes occurred, and historic locations where strikes occurred when precise latitude and longitude were known. Of note, in order to improve mitigation effectiveness, in fall 2022 the Navy made several changes to its Lookout training. The Navy revised its basic Lookout training materials to improve marine mammal awareness and spotting techniques through updates to the Marine Mammal chapter of the Navy’s September 2022 Lookout Training Handbook. Further, the Navy integrated improved Lookout training into a new generation of a shipboard simulator at its recruit training center in the Great Lakes. This simulator enhances new sailor knowledge and skill under realistic training scenarios. Last, the Navy will evaluate future revisions to online or DVD Marine Species Awareness Training video training to emphasize that when a protected species is spotted, this may be an indicator that additional marine mammals are present and nearby, and the vessel should take this into consideration when transiting. E:\FR\FM\03OCP2.SGM 03OCP2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules In addition to Lookouts required under this proposed rule, the Navy mandates the number of Lookouts on underway vessels per internal policy documents, including the Surface Ship NAVDORM. As described in the Standard Operating Procedures section, in 2021, NAVDORM policy changed to require three Lookouts on most classes of surface ship, including destroyers and cruisers. However, the Navy asserts that always including three Lookouts on these vessels in the future as a required mitigation measure is not practicable because lookout numbers are subject to change based on national security needs, including manning and staffing requirements. As such, although the Navy describes these additional Lookouts in its application under the mitigation section, NMFS has not considered the potential presence of two additional lookouts when considering Navy’s mitigation effectiveness. Please see the Proposed Reporting section for additional detail on this proposed requirement. With the exception of Oedekoven and Thomas (2022) described above, there is no new information that affects NMFS’ assessment of the applicability or effectiveness of the measures included in the 2018 HSTT final rule over the remainder of the 7-year period. As stated above in the Potential Effects of Specified Activities on Marine Mammals and Their Habitat section, while (Oedekoven and Thomas, 2022) suggests that detection of marine mammals is less certain than previously assumed at certain distances, model assumptions may still underestimate Lookout effectiveness in some cases. Additionally, maneuvering data summarized above demonstrates that Navy vessels are successfully maneuvering to avoid striking sighted marine mammals in most cases, despite the Oedekoven and Thomas (2022) results. Further, as described above, Navy and NMFS have developed modified or new mitigation in this proposed rule which are anticipated to further reduce the risk of vessel strike of large whales. In summary, and as described in more detail above regarding vessel strike, the Navy has agreed to procedural mitigation measures that will reduce the probability and/or severity of impacts expected to result from acute exposure to acoustic sources or explosives, vessel strike, and impacts to marine mammal habitat. Specifically, the Navy will use a combination of delayed starts, powerdowns, and shutdowns to minimize or avoid M/SI and minimize the likelihood or severity of PTS or other injury, and reduce instances of TTS or more severe behavioral disturbance caused by acoustic sources or explosives. The Navy will also implement multiple time/area restrictions (several of which were 68325 added in the 2018 HSTT final rule since the previous HSTT MMPA incidental take rule) that would reduce take of marine mammals in areas or at times where they are known to engage in important behaviors, such as feeding or calving, where the disruption of those behaviors would have a higher probability of resulting in impacts on reproduction or survival of individuals that could lead to population-level impacts. Table 8 provides the Navy’s required procedural mitigation measures for environmental awareness and education and vessel movement as well as summaries of the Navy’s procedural mitigation measures for other activities. Table 9 provides summaries of mitigation areas for the HSTT Study Area. NMFS and the Navy considered mitigation areas to protect marine mammals, including odontocetes with small or resident populations in the HSTT Study Area. This included consideration of new mitigation areas based on newly identified BIAs in Hawaii (Kratofil et al. 2023). Including additional mitigation areas beyond that included in the 2020 HSTT final rule is impracticable given overlap with critical Navy training areas in the HRC. However, many of the BIAs identified in Kratofil et al. 2023 partially or fully overlap the mitigation areas included in the 2020 HSTT final rule and proposed herein. ddrumheller on DSK120RN23PROD with PROPOSALS2 TABLE 8—SUMMARY OF PROCEDURAL MITIGATION Stressor or activity Mitigation zone sizes and other requirements Environmental Awareness and Education ................................................................ • This mitigation applies to all training and testing activities, as applicable. • Mitigation Requirements: Æ Appropriate Navy personnel (including civilian personnel) involved in mitigation and training or testing activity reporting under the specific activities must complete one or more modules of the U.S. Navy Afloat Environmental Compliance Training Series, as identified in their career path training plan. Modules include: D Introduction to the U.S. Navy Afloat Environmental Compliance Training Series. The introductory module provides information on environmental laws (e.g., ESA, MMPA) and the corresponding responsibilities that are relevant to Navy training and testing activities. The material explains why environmental compliance is important in supporting the Navy’s commitment to environmental stewardship. D Marine Species Awareness Training. All bridge watch personnel, Commanding Officers, Executive Officers, maritime patrol aircraft aircrews, anti-submarine warfare and mine warfare rotary-wing aircrews, Lookouts, and equivalent civilian personnel must successfully complete the Marine Species Awareness Training prior to standing watch or serving as a Lookout. The Marine Species Awareness Training provides information on sighting cues, visual observation tools and techniques, and sighting notification procedures. Navy biologists developed Marine Species Awareness Training to improve the effectiveness of visual observations for biological resources, focusing on marine mammals and sea turtles, and including floating vegetation, jellyfish aggregations, and flocks of seabirds. D U.S. Navy Protective Measures Assessment Protocol. This module provides the necessary instruction for accessing mitigation requirements during the event planning phase using the Protective Measures Assessment Protocol software tool. D U.S. Navy Sonar Positional Reporting System and Marine Mammal Incident Reporting. This module provides instruction on the procedures and activity reporting requirements for the Sonar Positional Reporting System and marine mammal incident reporting. Depending on sonar source: Active Sonar .............................................................................................................. VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 PO 00000 Frm 00037 Fmt 4701 Sfmt 4702 E:\FR\FM\03OCP2.SGM 03OCP2 68326 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules TABLE 8—SUMMARY OF PROCEDURAL MITIGATION—Continued Stressor or activity Mitigation zone sizes and other requirements Air Guns ..................................................................................................................... Pile Driving ................................................................................................................ Weapons Firing Noise ............................................................................................... Explosive Sonobuoys ................................................................................................ Explosive Torpedoes ................................................................................................. Explosive Medium-Caliber and Large-Caliber Projectiles ......................................... • • • • • • • Explosive Mine Neutralization Activities Involving Navy Divers ................................ • • • • • • • • Underwater Demolition Multiple Charge—Mat Weave and Obstacle Loading ......... Maritime Security Operations—Anti-Swimmer Grenades ......................................... Vessel Movement ...................................................................................................... • • • • Explosive Missiles and Rockets ................................................................................ Explosive Bombs ....................................................................................................... Sinking Exercises ...................................................................................................... Explosive Mine Countermeasure and Neutralization Activities ................................. • • • Towed In-Water Devices ........................................................................................... Small-, Medium-, and Large-Caliber Non-Explosive Practice Munitions .................. Non-Explosive Missiles and Rockets ........................................................................ Non-Explosive Bombs and Mine Shapes .................................................................. • • • • • 1,000 yd (914.4 m) power down, 500 yd (457.2 m) power down, and 200 yd (182.9 m) shut down • 200 yd (182.9 m) shut down. 150 yd (137.2 m). 100 yd (91.4 m). 30 degrees on either side of the firing line out to 70 yd (64 m). 600 yd (548.6 m). 2,100 yd (1,920.2 m). 1,000 yd (914.4 m; large-caliber projectiles). 600 yd (548.6 m; medium-caliber projectiles during surface-to-surface activities). 200 yd (182.9 m; medium-caliber projectiles during air-to-surface activities). 2,000 yd (1,828.8 m; 21–500 lb. net explosive weight). 900 yd (823 m; 0.6–20 lb. net explosive weight). 2,500 yd (2,286 m). 2.5 nmi (4.6 km). 2,100 yd (1,929.2 m; 6–650 lb net explosive weight). 600 yd (548.6 m; 0.1–5 lb net explosive weight). 1,000 yd (914.4 m; 21–60 lb net explosive weight for positive control charges and charges using time-delay fuses). 500 yd (457.2 m; 0.1–20 lb net explosive weight for positive control charges). 700 yd (640.1 m). 200 yd (182.9 m). The mitigation must not be applied if: (1) The vessel’s safety is threatened, (2) the vessel is restricted in its ability to maneuver (e.g., during launching and recovery of aircraft or landing craft, during towing activities, when mooring), (3) the vessel is operated autonomously, or (4) when impractical based on mission requirements (e.g., during Amphibious Assault—Battalion Landing exercises). Number of Lookouts and Observation Platform: Æ 1 Lookout must be on the vessel that is underway.1 Mitigation Requirements: Æ Mitigation zones:—500 yd (457.2 m) around whales.—200 yd (182.9 m) around other marine mammals (except bow-riding dolphins and pinnipeds hauled out on man-made navigational structures, port structures, and vessels). Æ During the activity:—When underway, Navy personnel must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must maneuver (which may include reducing speed as the mission or circumstances allow) to maintain distance. Additional requirements: Æ If a marine mammal vessel strike occurs, Navy personnel must follow the established incident reporting procedures. Navy personnel must also send alerts to Navy vessels of increased risk of strike following any reported Navy vessel strike in the HSTT Study Area. Æ Navy personnel must issue real-time notifications to Navy vessels of large whale aggregations (four or more whales) within 1 nmi (1.9 km) of a Navy vessel in the area between 32–33 degrees North and 117.2–119.5 degrees West. 250 yd (228.6 m; marine mammals). 200 yd (182.9 m). 900 yd (823 m). 1,000 yd (914.4 m). Note: lb: pounds; nmi: nautical miles; yd: yards; m: meters. 1 Underway vessels will maintain at least one Lookout. For ship classes required to maintain more than one Lookout, the specific requirement is subject to change over time in accordance with Navy navigation instruction (e.g., the Surface Ship NAVDORM). Navy personnel will notify NMFS as soon as practicable should its Lookout policies change, including in the NAVDORM. TABLE 9—SUMMARY OF MITIGATION AREAS FOR MARINE MAMMALS ddrumheller on DSK120RN23PROD with PROPOSALS2 Summary of mitigation area requirements Hawaii Island Mitigation Area (year-round): • Navy personnel must not conduct more than 300 hours of MF1 surface ship hull-mounted mid-frequency active sonar or 20 hours of MF4 dipping sonar, or use explosives that could potentially result in takes of marine mammals during training and testing.1 4-Islands Region Mitigation Area (November 15–April 15 for active sonar; year-round for explosives): • Navy personnel must not use MF1 surface ship hull-mounted mid-frequency active sonar or explosives that could potentially result in takes of marine mammals during training and testing.1 Humpback Whale Special Reporting Areas (December 15–April 15): • Navy personnel must report the total hours of surface ship hull-mounted mid-frequency active sonar used in the special reporting areas in its annual training and testing activity reports submitted to NMFS. San Diego Arc, San Nicolas Island, and Santa Monica/Long Beach Mitigation Areas (June 1–October 31): • Navy personnel must not conduct more than a total of 200 hours of MF1 surface ship hull-mounted mid-frequency active sonar in the combined areas, excluding normal maintenance and systems checks, during training and testing.1 • Within the San Diego Arc Mitigation Area, Navy personnel must not use explosives that could potentially result in the take of marine mammals during largecaliber gunnery, torpedo, bombing, and missile (including 2.75″ rockets) activities during training and testing.1 • Within the San Nicolas Island Mitigation Area, Navy personnel must not use explosives that could potentially result in the take of marine mammals during mine warfare, large-caliber gunnery, torpedo, bombing, and missile (including 2.75″ rockets) activities during training.1 • Within the Santa Monica/Long Beach Mitigation Area, Navy personnel must not use explosives that could potentially result in the take of marine mammals during mine warfare, large-caliber gunnery, torpedo, bombing, and missile (including 2.75″ rockets) activities during training and testing.1 Santa Barbara Island Mitigation Area (year-round): VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 PO 00000 Frm 00038 Fmt 4701 Sfmt 4702 E:\FR\FM\03OCP2.SGM 03OCP2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules 68327 TABLE 9—SUMMARY OF MITIGATION AREAS FOR MARINE MAMMALS—Continued Summary of mitigation area requirements • Navy personnel must not use MF1 surface ship hull-mounted mid-frequency active sonar during training and testing, or explosives that could potentially result in the take of marine mammals during medium-caliber or large-caliber gunnery, torpedo, bombing, and missile (including 2.75″ rockets) activities during training.1 Awareness Notification Message Areas (seasonal according to species): • Navy personnel must issue awareness notification messages to alert ships and aircraft to the possible presence of large whales during a period based on predicted oceanographic conditions for a given year. The message must emphasize that when a marine mammal is spotted, this may be an indicator that additional marine mammals are present and nearby, and increased vigilance and awareness of Navy personnel is warranted. Navy personnel must also issue awareness notification messages to alert ships and aircraft to the possible presence of gray whales (November–March) and fin whales (November–May). ddrumheller on DSK120RN23PROD with PROPOSALS2 1 If Naval units need to conduct more than the specified amount of training or testing, they will obtain permission from the appropriate designated Command authority prior to commencement of the activity. The Navy will provide NMFS with advance notification and include the information in its annual activity reports submitted to NMFS. Mitigation Conclusions NMFS has carefully evaluated the Navy’s mitigation measures from the 2020 rule—many of which were developed with NMFS’ input during the previous phases of Navy training and testing authorizations and none of which have changed since our evaluation during the 2018 HSTT rulemaking, with the exception of the changes described herein—and considered a broad range of other measures (i.e., the measures considered but eliminated in the 2018 HSTT FEIS/ OEIS, which reflect many of the comments that have arisen via NMFS or public input in past years) in the context of ensuring that NMFS prescribes the means of effecting the least practicable adverse impact on the affected marine mammal species and stocks and their habitat. Our evaluation of potential measures included consideration of the following factors in relation to one another: the manner in which, and the degree to which, the successful implementation of the mitigation measures is expected to reduce the likelihood and/or magnitude of adverse impacts to marine mammal species and stocks and their habitat; the proven or likely efficacy of the measures; and the practicability of the measures for applicant implementation, including consideration of personnel safety, practicality of implementation, and impact on the effectiveness of the military readiness activity. After considering all new information, including consideration of new information regarding vessel strike, NMFS proposes two additional mitigation measures and revision of two existing mitigation measures as described above. Based on our evaluation of the Navy’s current mitigation measures (which are being implemented under the 2020 HSTT regulations), as well as modified and new measures described above, NMFS has preliminarily determined that the proposed mitigation measures are appropriate means of effecting the least practicable adverse impact on VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 marine mammal species or stocks and their habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance, and considering specifically personnel safety, practicality of implementation, and impact on the effectiveness of the military readiness activity. Additionally, as described in more detail below, the 2020 HSTT final rule includes an adaptive management provision, which the Navy proposes to extend, which ensures that mitigation is regularly assessed and provides a mechanism to improve the mitigation, based on the factors above, through modification as appropriate. The proposed rule comment period provides the public an opportunity to submit recommendations, views, and/or concerns regarding the Navy’s activities and the proposed mitigation measures. While NMFS has preliminarily determined that the proposed mitigation measures would effect the least practicable adverse impact on the affected species or stocks and their habitat, NMFS will consider all public comments to help inform our final decision. Consequently, the proposed mitigation measures may be refined, modified, removed, or added to prior to the issuance of the final rule based on public comments received, and where appropriate, further analysis of any additional mitigation measures. Proposed Monitoring Section 101(a)(5)(A) of the MMPA states that in order to authorize incidental take for an activity, NMFS must set forth requirements pertaining to the monitoring and reporting of such taking. The MMPA implementing regulations at 50 CFR 216.104(a)(13) indicate that requests for incidental take authorizations must include the suggested means of accomplishing the necessary monitoring and reporting that will result in increased knowledge of the species and of the level of taking or impacts on populations of marine mammals that are expected to be present. PO 00000 Frm 00039 Fmt 4701 Sfmt 4702 In its 2022 application, the Navy proposes no changes to the monitoring described in the 2018 HSTT final rule and 2020 HSTT final rule. They would continue implementation of the robust Integrated Comprehensive Monitoring Program and Strategic Planning Process described in the 2018 HSTT final rule. The Navy’s monitoring strategy, currently required by the 2018 HSTT regulations, is well-designed to work across Navy ranges to help better understand the impacts of the Navy’s activities on marine mammals and their habitat by focusing on learning more about marine mammal occurrence in different areas and exposure to Navy stressors, marine mammal responses to different sound sources, and the consequences of those exposures and responses on marine mammal populations. Similarly, these proposed modified regulations would include identical adaptive management provisions and reporting requirements as the 2018 HSTT regulations. There is no new information that would indicate that the monitoring measures put in place under the 2018 HSTT final rule would not remain applicable and appropriate for the 7-year period of this proposed rule. See the Monitoring section of the 2018 HSTT final rule for more details on the monitoring program that would be required under this rule. In addition, please see the 2019 Navy application, which references Chapter 13 of the 2017 Navy application for full details on the monitoring and reporting proposed by the Navy. Within the SOCAL portion of HSTT, the Navy has been primarily focused on beaked whale monitoring since 2018 through two separate ongoing projects that are expected to continue until 2025. These projects use passive acoustic devices, visual surveys, satellite tagging, genetic analysis, photoID, and response to anthropogenic sounds to refine population status of beaked whales in SOCAL. There is also one concurrent project with fin whales using visual surveys, satellite tagging, and photoID to gather additional data on fin whale E:\FR\FM\03OCP2.SGM 03OCP2 68328 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules ddrumheller on DSK120RN23PROD with PROPOSALS2 populations in Southern California. Finally, the Navy continues to fund marine mammal sighting data collected during California Cooperative Oceanic Fisheries Investigations (CALCOFI) https://calcofi.org/. These data are collected on a much more frequent basis than NMFS’ West Coast visual survey which typically occur once every 5 years in the summer. CALCOFI surveys occur quarterly every year to include winter and spring seasons NMFS does not survey. Sufficient marine mammal sightings have been accumulated since the Navy started funding in 2004 for the data to be incorporated into ongoing NMFS spatial habitat models, including new models for select species. The Navy also annually funds continued NMFS spatial habitat model improvements as new data and techniques become available. These models benefit the Navy and other Federal partners such as the Bureau of Ocean Energy Management and NMFS, for use in future regional marine mammal density derivation. For additional information, please see the Navy’s Marine Species Monitoring program website, https:// www.navymarinespeciesmonitoring.us/ regions/pacific/current-projects/. Adaptive Management The 2020 HSTT regulations governing the take of marine mammals incidental to Navy training and testing activities in the HSTT Study Area contain an adaptive management component. Our understanding of the effects of Navy training and testing activities (e.g., acoustic and explosive stressors) on marine mammals continues to evolve, which makes the inclusion of an adaptive management component both valuable and necessary within the context of 7-year regulations. The 2022 Navy application proposes no changes to the adaptive management component included in the 2020 HSTT final rule. The reporting requirements associated with this rule are designed to provide NMFS with monitoring data from the previous year to allow NMFS to consider whether any changes to existing mitigation and monitoring requirements are appropriate. The use of adaptive management allows NMFS to consider new information from different sources to determine (with input from the Navy regarding practicability) on an annual or biennial basis if mitigation or monitoring measures should be modified (including additions or deletions). Mitigation measures could be modified if new data suggests that such modifications would have a reasonable likelihood of more effectively accomplishing the goals of the mitigation and monitoring and if the VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 measures are practicable. If the modifications to the mitigation, monitoring, or reporting measures are substantial, NMFS will publish a notice of the planned LOA in the Federal Register and solicit public comment. The following are some of the possible sources of applicable data to be considered through the adaptive management process: (1) results from monitoring and exercises reports, as required by MMPA authorizations; (2) compiled results of Navy funded R&D studies; (3) results from specific stranding investigations; (4) results from general marine mammal and sound research; and (5) any information which reveals that marine mammals may have been taken in a manner, extent, or number not authorized by these regulations or subsequent LOAs. The results from monitoring reports and other studies may be viewed at https:// www.navymarinespeciesmonitoring.us. Proposed Reporting In order to issue incidental take authorization for an activity, section 101(a)(5)(A) of the MMPA states that NMFS must set forth requirements pertaining to the monitoring and reporting of such taking. Effective reporting is critical both to compliance as well as ensuring that the most value is obtained from the required monitoring. Reports from individual monitoring events, results of analyses, publications, and periodic progress reports for specific monitoring projects will be posted to the Navy’s Marine Species Monitoring web portal: https:// www.navymarinespeciesmonitoring.us. The 2019 Navy application and 2022 Navy application proposed no changes to the reporting requirements, though as noted above, the Navy has since proposed to report changes to Lookout SOPs to NMFS. Except as discussed below, reporting requirements would remain identical to those described in the 2018 HSTT final rule and 2020 HSTT final rule, and there is no new information that would indicate that the reporting requirements put in place under the 2020 HSTT final rule would not remain applicable and appropriate for the remaining duration of the 7-year period of this proposed rule. See the Reporting section of the 2018 HSTT final rule for more details on the reporting that would be required under this rulemaking. In addition, the 2018 HSTT proposed and final rules unintentionally failed to include the requirement for the Navy to submit a final activity ‘‘close out’’ report at the end of the regulatory period. That oversight was corrected through the 2020 HSTT final rule. Please see the PO 00000 Frm 00040 Fmt 4701 Sfmt 4702 2020 HSTT final rule for the detailed requirements for that report. In addition to the reporting requirements included in the 2020 HSTT final rule, the Navy must report changes in its Lookout policies to NMFS as soon as practicable after a change is made. Preliminary Analysis and Negligible Impact Determination NMFS has defined negligible impact as an impact resulting from the specified activity that cannot be reasonably expected to, and is not reasonably likely to, adversely affect the species or stock through effects on annual rates of recruitment or survival (50 CFR 216.103). A negligible impact finding is based on the lack of likely adverse effects on annual rates of recruitment or survival (i.e., populationlevel effects). While this proposed rule consists of a modification of take by M/ SI by vessel strike, NMFS considers the impacts of the entire specified activity and the total taking in the negligible impact determination. An estimate of the number of takes alone is not enough information on which to base an impact determination. In addition to considering estimates of the number of marine mammals that might be taken through mortality, serious injury, and Level A or Level B harassment (as presented in tables 11 and 12 of the 2020 HSTT final rule), NMFS considers other factors, such as the likely nature of any responses (e.g., intensity, duration), the context of any responses (e.g., critical reproductive time or location, migration), as well as effects on habitat, and the likely effectiveness of the mitigation. We also assess the number, intensity, and context of estimated takes by evaluating this information relative to population status. Consistent with the 1989 preamble for NMFS’ implementing regulations (54 FR 40338; September 29, 1989), the impacts from other past and ongoing anthropogenic activities (including foreign military activities) are incorporated into this analysis via their impacts on the environmental baseline (e.g., as reflected in the regulatory status of the species, population size and growth rate where known, other ongoing sources of human-caused mortality, ambient noise levels, and specific consideration of take by Level A harassment or M/SI previously authorized for other NMFS activities). In the Estimated Take of Marine Mammals sections of this proposed rule and the 2020 HSTT final rule (where the activities, species and stocks, potential effects, and mitigation measures are the same as for this rulemaking), we E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules identified the subset of potential effects that would be expected to rise to the level of takes both annually and over the 7-year period covered by this rulemaking and then identified the number of each of those mortality takes that we believe could occur or the maximum number of harassment takes that are reasonably expected to occur based on the methods described. The impact that any given take will have is dependent on many case-specific factors that need to be considered in the negligible impact analysis (e.g., the context of behavioral exposures such as duration or intensity of a disturbance, the health of impacted animals, the status of a species that incurs fitnesslevel impacts to individuals, etc.). For this proposed rule, we evaluated the likely impacts of the enumerated maximum number of harassment takes that are reasonably expected to occur and proposed for authorization, in the context of the specific circumstances surrounding these predicted takes. We also assessed M/SI takes that could occur, as well as considering the traits and statuses of the affected species and stocks. Last, we collectively evaluated this information, as well as other more taxa-specific information and mitigation measure effectiveness, in group-specific assessments that support our negligible impact conclusions for each stock or species. Because all of the Navy’s specified activities would occur within the ranges of the marine mammal stocks identified in the rule, all negligible impact analyses and determinations are at the stock level (i.e., additional species-level determinations are not needed). The Navy proposes no changes to the nature or level of the specified activities or the boundaries of the HSTT Study Area, and therefore, the training and testing activities (e.g., equipment and sources used, exercises conducted) are the same as those analyzed in the 2020 HSTT final rule. In addition, the mitigation, monitoring, and nearly all reporting measures are identical to those described and analyzed in the 2018 HSTT final rule with the exception of changes to mitigation measures described previously and the additional reporting requirement for Navy to report changes in its Lookout policies to NMFS as soon as practicable after a change is made. There is no new information since the publication of the 2020 HSTT final rule regarding the impacts of the specified activities on marine mammals, the status and distribution of any of the affected marine mammal species or stocks, or the effectiveness of the mitigation and monitoring measures VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 that would change the content of our analyses, with the exception of that described below. First, naval vessel strikes have occurred in the HSTT and Atlantic Fleet Training and Testing (AFTT) Study Areas since publication of the 2020 HSTT final rule (one fin or sei whale struck by the U.S. Navy in the HSTT Study Area (2023), two unidentified large whales struck by the U.S. Navy in the HSTT Study Area (2021), two fin whales struck by a foreign navy in the HSTT Study Area (2021), and one dolphin struck by the U.S. Navy in the AFTT Study Area (2021)). Second, for gray whales, we have considered the latest effects of the UME on the west coast of North America along with the effects of the Navy’s activities in the negligible impact analysis. Third, a new study suggests that Lookout detection of marine mammals is less certain than previously assumed (Oedekoven and Thomas, 2022). Fourth, stock assessments have been updated for multiple stocks in the 2022 Pacific and Alaska SARs (Carretta et al. 2023; Young et al. 2023). As described above and in the 2022 Navy application, a number of additional studies have been published, including several studies associated with TTS in harbor porpoises and seals (e.g., Kastelein et al. 2020d; Kastelein et al. 2021a and 2021b; Sills et al. 2020). NMFS is aware of these recent papers and is currently working with the Navy to update NMFS’ Technical Guidance for Assessing the Effects of Anthropogenic Sound on Marine Mammal Hearing Version 2.0 (Acoustic Technical Guidance; NMFS 2018) to reflect relevant papers that have been published since the 2018 update on our 3–5 year update schedule in the Acoustic Technical Guidance. We note that the recent peer-reviewed, updated marine mammal noise exposure criteria by Southall et al. (2019) provide identical PTS and TTS thresholds and weighting functions to those provided in NMFS’ Acoustic Technical Guidance. NMFS will continue to review and evaluate new relevant data as it becomes available and consider the impacts of those studies on the Acoustic Technical Guidance to determine what revisions/ updates may be appropriate. However, any such revisions must undergo peer and public review before being adopted, as described in the Acoustic Guidance methodology. While some of the relevant data may potentially suggest changes to TTS/PTS thresholds for some species, any such changes would not be expected to change the predicted take estimates in a manner that would PO 00000 Frm 00041 Fmt 4701 Sfmt 4702 68329 change the necessary determinations supporting the issuance of these regulations, and the data and values used in this rulemaking reflect the best available science. Harassment As described in the Estimated Takes of Marine Mammals section, the annual number of takes proposed for authorization and reasonably expected to occur by Level A harassment and Level B harassment (based on the maximum number of activities per 12month period) are identical to those presented in tables 41 and 42 in the Take Requests section of the 2018 HSTT final rule, with the exception of humpback whale, which are presented in tables 2 and 3 herein. As such, the negligible impact analyses and determinations of the effects of the estimated Level A harassment and Level B harassment takes on annual rates of recruitment or survival for each species and stock are nearly identical to and substantively unchanged from those presented in the 2020 HSTT final rule. The differences in the analysis is our removal of consideration of California Sea Lion UME, which has been closed since publication of the 2020 HSTT final rule, and incorporation of the revised stock structure for humpback whales. This does not affect the results of the analyses or our determinations. For detailed discussion of the impacts that affected individuals may experience given the specific characteristics of the specified activities and required mitigation (e.g., from behavioral disruption, masking, and temporary or permanent threshold shift), along with the effects of the expected Level A harassment and Level B harassment take on reproduction and survival, see the applicable subsections in the Analysis and Negligible Impact Determination section of the 2018 HSTT final rule (83 FR 66977–67018; also incorporated by reference in the 2020 HSTT final rule). Serious Injury or Mortality Based on the information and methods discussed in the Estimated Take of Marine Mammals section (which are identical to those used in the 2018 HSTT final rule for explosives and revised for vessel strike), NMFS is proposing to authorize five mortalities of large whales due to vessel strike over the 7-year period of this rulemaking, two more strikes than what was authorized in the 2018 HSTT final rule and 2020 HSTT final rule. Across the 7year duration of the rule, take of an annual average of 0.57 gray whales (Eastern North Pacific stock) and fin E:\FR\FM\03OCP2.SGM 03OCP2 68330 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules whales (CA/OR/WA stock), an annual average of 0.29 humpback whales (Hawaii stock) and an annual average of 0.14 blue whales (Eastern North Pacific stock), sei whales (Eastern North Pacific stock) and humpback whales (Mainland Mexico-CA/OR/WA stock, Mexico DPS), as described in table 8 (i.e., one, two, or four take(s) over 7 years divided by seven to get the annual number) could occur and are proposed for authorization. TABLE 10—SUMMARY INFORMATION RELATED TO MORTALITIES REQUESTED FOR VESSEL STRIKE [2018–2025] Fisheries interactions (Y/N); annual rate of M/SI from fisheries interactions * Annual rate of M/SI from vessel collision * ≥43.6 Y; ≥0.64 ............ Y, 43 ............... 80 36.4 0.57 131 Y, 9.3 ................ Y, 1.8 .............. 801 3,477 0.14 22 Y; 11.4 .............. Y, 10.15 .......... 11,278 0.29 27.09 Y; 8.39 .............. 7 Y, 1,898 0.14 ≥19.5 519 0.14 ≥0.2 Stock abundance (Nbest) * Annual authorized take by serious injury or mortality 1 Fin whale (CA/OR/WA stock). Gray whale (Eastern North Pacific stock). 11,065 0.57 26,960 Humpback whale (Mainland Mexico-CA/OR/WA stock, Mexico DPS). Humpback whale (Hawaii stock). Blue whale (Eastern North Pacific Stock). Sei whale (Eastern North Pacific Stock). Species (stock) Total annual M/SI * 2 Potential biological removal (PBR) * Residual PBR (PBR minus annual M/SI) 3 Stock trend * 4 Recent UME (Y/N); number and year (since 2007) ↑ ..................... N. 670 5↑ 65 6 43 Unknown ........ Y; 674; 2019 (as of June 25, 2023). N. 10.59 ....... 127 99.91 Unknown ........ Y; 2015; 52.] Y; ≥1.54 ............ Y, 0.8 .............. 4.1 -15.4 Unknown ........ Y; 3, 2007. N; 0 .................. Y, 0.2 .............. 0.75 0.55 Unknown ........ N. ................... * Presented in the 2022 final SARs. 1 This column represents the annual take by serious injury or mortality (M/SI) by vessel collision and was calculated by the number of mortalities proposed for authorization divided by 7 years (the length of the rule and LOAs). 2 This column represents the total number of incidents of M/SI that could potentially accrue to the specified species or stock. This number comes from the SAR, but deducts the takes accrued from either Navy strikes or NMFS’ Southwest Fisheries Science Center (SWFSC) takes in the SARs to ensure not double-counted against PBR. However, for these species, there were no takes from either other Navy activities or SWFSC in the SARs to deduct that would be considered double-counting. 3 This value represents the calculated PBR less the average annual estimate of ongoing anthropogenic mortalities (i.e., total annual human-caused M/SI, which is presented in the SARs). 4 See relevant SARs for more information regarding stock status and trends. 5 The Pacific 2022 SAR indicates that the stock trend is increasing. However, recent (2021–2022) surveys conducted by NMFS’ Southwest Fisheries Science Center estimated that the population has declined to 16,650 whales, though the authors note that this stock has historically shown a pattern of population growth and decline that has not impacted the population in the long term (Eguchi et al. 2022). 6 Vessel strike of the Mainland Mexico-CA/OR/WA stock was calculated by applying a prorated portion of humpback whale strikes modeled by Rockwood et al. (2017) to this stock. 7 For this stock, PBR is currently set at 43 for U.S. waters and 65 for the stock’s entire range. As the HSTT Study Area extends beyond U.S. waters and activities have the potential to impact the entire stock, we present the analysis using the PBR for the stock’s entire range. 8 Annual vessel strike for this stock reported in the 2022 final SAR was calculated by summing vessel strike data from Hawaii, Alaska, and Washington. All observed strikes in Hawaii were assigned to the Hawaii stock, and a portion of observed strikes in Alaska were assigned to the Hawaii stock. Vessel strike of the Hawaii stock in Washington waters was calculated by applying a prorated portion of humpback whale strikes modeled by Rockwood et al. (2017) to the Hawaii stock. The Navy also requested a small number of takes by M/SI from explosives in the 2017 Navy application. To calculate the annual average of mortalities for explosives in table 11, we used the same method as described for vessel strikes. The annual average is the total number of takes over 7 years divided by seven. Specifically, NMFS is proposing to authorize the following M/SI takes from explosives: five California sea lions and eight shortbeaked common dolphins over the 7year period (therefore 0.71 mortalities annually for California sea lions and 1.14 mortalities annually for shortbeaked common dolphin), as described in table 11. As this annual number is the same as that analyzed and authorized in the 2020 HSTT final rule, and no other relevant information about the status, abundance, or effects of mortality on each species or stock has changed, the analysis of the effects of explosives is identical to that presented in the 2020 HSTT final rule. TABLE 11—SUMMARY INFORMATION RELATED TO MORTALITIES FROM EXPLOSIVES [2018–2025] ddrumheller on DSK120RN23PROD with PROPOSALS2 Species (stock) California sea lion (U.S. stock) .............. Short-beaked common dolphin (CA/OR/ WA stock). Stock abundance (Nbest) * Annual authorized take by serious injury or mortality 1 257,606 1,056,308 0.71 1.14 Fisheries interactions (Y/N); annual rate of M/SI from fisheries interactions * Total annual M/SI* 2 ≥321 ≥30.5 Y; ≥197 ............. Y; ≥30.5 ............ PBR * SWFSC authorized take (annual) 3 14,011 8,889 Residual PBR—PBR minus annual M/SI and SWFSC 4 6 2.8 13,684 8,855.7 Stock trend* 5 ↑ ? UME (Y/N); number and year N N * Presented in the 2022 draft SARs or most recent SAR. 1 This column represents the annual take by serious injury or mortality (M/SI) during explosive detonations and was calculated by the number of mortalities planned for authorization divided by 7 years (the length of the rule and LOAs). 2 This column represents the total number of incidents of M/SI that could potentially accrue to the specified species or stock. This number comes from the SAR. 3 This column represents annual take authorized through NMFS’ SWFSC rulemaking/LOAs (86 FR 3840; January 15, 2021). 4 This value represents the calculated PBR less the average annual estimate of ongoing anthropogenic mortalities (i.e., total annual human-caused M/SI column and the annual authorized take from the SWFSC column. In the case of California sea lion the M/SI column (321) and the annual authorized take from the SWFSC (6) were subtracted from the calculated PBR of 14,011. In the case of short-beaked common dolphin the M/SI column (30.5) and the annual authorized take from the SWFSC (2.8) were subtracted from the calculated PBR of 8,889. 5 See relevant SARs for more information regarding stock status and trends. VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 PO 00000 Frm 00042 Fmt 4701 Sfmt 4702 E:\FR\FM\03OCP2.SGM 03OCP2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules ddrumheller on DSK120RN23PROD with PROPOSALS2 See the Serious Injury or Mortality subsection in the Analysis and Negligible Impact Determination section of the 2018 HSTT final rule (83 FR 66985–66993) for detailed discussions of the impacts of M/SI, including a description of how the agency uses the PBR metric and other factors to inform our analysis and an analysis of the impacts on each species and stock for which M/SI is proposed for authorization, including the relationship of potential mortality for each species to the insignificance threshold and residual PBR, except as updated below. Stocks With M/SI Below the Insignificance Threshold As noted in the Serious Injury or Mortality subsection of the Negligible Impact Analysis and Determination section in the 2018 HSTT final rule and 2020 HSTT final rule, for a species or stock with incidental M/SI less than 10 percent of residual PBR, we consider M/ SI from the specified activities to represent an insignificant incremental increase in ongoing anthropogenic M/SI that alone (i.e., in the absence of any other take and barring any other unusual circumstances) will clearly not adversely affect annual rates of recruitment and survival. In this case, as shown in table 10 and table 11, the following species or stocks have potential or estimated M/SI from vessel strike and explosive takes, respectively, and proposed for authorization below their insignificance threshold: fin whale (CA/OR/WA stock), gray whale (Eastern North Pacific stock), humpback whale (Hawaii stock and Mainland MexicoCA/OR/WA stock), California sea lion (U.S stock), and short-beaked common dolphin (CA/OR/WA stock). While the proposed authorized M/SI of gray whales (Eastern North Pacific stock) is below the insignificance threshold, because of the recent UME, we further address how the proposed authorized M/SI and the UME inform the negligible impact determination immediately below. For the other four stocks with proposed authorized M/SI below the insignificance threshold, there are no other known factors, information, or unusual circumstances that indicate anticipated M/SI below the insignificance threshold could have adverse effects on annual rates of recruitment or survival and they are not discussed further. For the remaining stocks with anticipated potential M/SI above the insignificance threshold, how that M/SI compares to residual PBR, as well as additional factors, as appropriate, are discussed below as well. VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 Gray Whales (Eastern North Pacific Stock) Since January 2019, gray whale strandings along the west coast of North America have been significantly higher than the previous 18-year averages. Preliminary findings from necropsies have shown evidence of emaciation. These findings are not consistent across all of the whales examined, so more research is needed. The seasonal pattern of elevated strandings in the spring and summer months is similar to that of the previous gray whale UME in 1999–2000. If strandings continue to follow a similar pattern, we would anticipate a decrease in strandings in late summer and fall. However, combined with other annual human-caused mortalities and viewed through the PBR lens (for human-caused mortalities), total human-caused mortality would still fall below residual PBR. Given the small number of takes by serious injury or mortality proposed for authorization, the proposed takes are not anticipated to exacerbate the ongoing UME. Stocks With M/SI Above the Insignificance Threshold Blue Whale (Eastern North Pacific Stock) For blue whales (Eastern North Pacific stock), PBR is currently set at 4.1 and the total annual M/SI is estimated at greater than or equal to 19.5, yielding a residual PBR of ¥15.4. This is slightly higher than the 2020 HSTT final rule (was ¥16.7). NMFS proposes to authorize one M/SI for the Navy over the 7-year duration of the rule (indicated as 0.14 annually for the purposes of comparing to PBR and evaluating overall effects on annual rates of recruitment and survival), which means that residual PBR is exceeded by 15.54. However, as described in the 2018 and 2020 rules, given that the negligible impact determination is based on the assessment of take of the activity being analyzed, when total annual mortality from human activities is higher, but the impacts from the specific activity being analyzed are very small, NMFS may still find the impact of the proposed authorized take from a specified activity to be negligible even if total humancaused mortality exceeds PBR if the proposed authorized mortality is less than 10 percent of PBR and management measures are being taken to address serious injuries and mortalities from the other activities causing mortality (i.e., other than the specified activities covered by the incidental take authorization in consideration). When those considerations are applied here, PO 00000 Frm 00043 Fmt 4701 Sfmt 4702 68331 the authorized lethal take (0.14 annually) of blue whales from the Eastern North Pacific stock is less than 10 percent of PBR (which is 4.1), and there are management measures in place to address M/SI from activities other than those the Navy is conducting (as discussed below). Perhaps more importantly, the available data suggests that the current number of vessel strikes is not likely to have an adverse impact on the population, despite the fact that it exceeds PBR, with the Navy’s minimal additional mortality of one whale in the 7 years not creating the likelihood of adverse impact. Immediately below, we explain the information that supports our finding that the Navy’s proposed authorized M/ SI is not expected to result in more than a negligible impact on this stock. As described previously, NMFS must also ensure that impacts by the applicant on the species or stock from other types of take (i.e., harassment) do not combine with the impacts from mortality to adversely affect the species or stock via impacts on annual rates of recruitment or survival, which occurs further below in the stock-specific conclusion sections. As discussed in the 2018 HSTT final rule and the 2020 HSTT final rule, the 2018 draft SAR and the more recent SARs rely on a new method to estimate annual deaths by vessel strike utilizing an encounter theory model that combined species distribution models of whale density, vessel traffic characteristics, and whale movement patterns obtained from satellite-tagged animals in the region to estimate encounters that would result in mortality (Rockwood et al. 2017). The model predicts 18 annual mortalities of blue whales from vessel strikes, which, with the additional M/SI of 1.54 from fisheries interactions, results in the current estimate of residual PBR being ¥15.4. Although NMFS’ Permits and Conservation Division in the Office of Protected Resources has independently reviewed the vessel strike model and its results and agrees that it is appropriate for estimating blue whale mortality by vessel strike on the U.S. West Coast, for analytical purposes we also note that if the historical method were used to predict vessel strike (i.e., using observed mortality by vessel strike, or 0.8, instead of 18), then total human-caused mortality including the Navy’s potential take would not exceed PBR. We further note that the authors (Rockwood et al. 2017) do not suggest that vessel strike suddenly increased to 18 recently. In fact, the model is not specific to a year, but rather offers a generalized E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68332 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules prediction of vessel strike off the U.S. West Coast. Therefore, if the Rockwood et al. (2017) model is an accurate representation of vessel strike, then similar levels of vessel strike have been occurring in past years as well. Put another way, if the model is correct, for some number of years total-humancaused mortality has been significantly underestimated and PBR has been similarly exceeded by a notable amount, and yet, the Eastern North Pacific stock of blue whales remains stable nevertheless. NMFS’ 2022 final SAR states that the current population trend is unknown, though there may be evidence of a population size increase since the 1990s. The SAR further cites to Monnahan et al. (2015), which used a population dynamics model to estimate that the Eastern North Pacific blue whale population was at 97 percent of carrying capacity in 2013 and to suggest that the observed lack of a population increase since the early 1990s was explained by density dependence, not impacts from vessel strike. This would mean that this stock of blue whales shows signs of stability and is not increasing in population size because the population size is at or nearing carrying capacity for its available habitat. In fact, we note that this population has maintained this status throughout the years that the Navy has consistently tested and trained at similar levels (with similar vessel traffic) in areas that overlap with blue whale occurrence, which would be another indicator of population stability. Monnahan et al. (2015) modeled vessel numbers, vessel strikes, and the population of the Eastern North Pacific blue whale population from 1905 out to 2050 using a Bayesian framework to incorporate informative biological information and assign probability distributions to parameters and derived quantities of interest. The authors tested multiple scenarios with differing assumptions, incorporated uncertainty, and further tested the sensitivity of multiple variables. Their results indicated that there is no immediate threat (i.e., through 2050) to the population from any of the scenarios tested, which included models with 10 and 35 strike mortalities per year. Broadly, the authors concluded that, unlike other blue whale stocks, the Eastern North Pacific blue whales have recovered from 70 years of whaling and are in no immediate threat from vessel strikes. They further noted that their conclusion conflicts with the depleted and strategic designation under the MMPA as well as PBR specifically. VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 As discussed, we also take into consideration management measures in place to address M/SI caused by other activities. The Channel Islands NMS staff coordinates, collects, and monitors whale sightings in and around the Vessel Speed Reduction (VSR) zones and the Channel Islands NMS region. Redfern et al. (2013) note that the most risky area for blue whales is the Santa Barbara Channel, where shipping lanes intersect with common feeding areas. The seasonally established Southern California VSR zone spans from Point Arguello to Dana Point, including the Traffic Separation Schemes in the Santa Barbara Channel and San Pedro Channel. Vessels transiting the area from May 1 through December 15, 2023 are recommended to exercise caution and voluntarily reduce speed to 10 kn (18.5 km per hour) or less for blue, humpback, and fin whales. (Note this is an expanded timeframe from the Whale Advisory Zone discussed in the 2020 HSTT final rule, which spanned June through November, though the effective period could change in future years.) Channel Island NMS observers collect information from aerial surveys conducted by NOAA, the U.S. Coast Guard, California Department of Fish and Game, and U.S. Navy chartered aircraft. Information on seasonal presence, movement, and general distribution patterns of large whales is shared with mariners, NMFS Office of Protected Resources, U.S. Coast Guard, California Department of Fish and Game, the Santa Barbara Museum of Natural History, the Marine Exchange of Southern California, and whale scientists. Real time and historical whale observation data collected from multiple sources can be viewed on the Point Blue Whale Database. In this case, 0.14 M/SI means one mortality in 1 of the 7 years and zero mortalities in 6 of those 7 years. Therefore, the Navy would not be contributing to the total human-caused mortality at all in 6 of the 7, or 85.7 percent, of the years covered by this rulemaking. That means that even if a blue whale were to be struck, in 6 of the 7 years there could be no effect on annual rates of recruitment or survival from Navy-caused M/SI. Additionally, the loss of a male would have far less, if any, effect on population rates and absent any information suggesting that one sex is more likely to be struck than another, we can reasonably assume that there is a 50 percent chance that the single strike authorized by this rulemaking would be a male, thereby further decreasing the likelihood of impacts on the population rate. In PO 00000 Frm 00044 Fmt 4701 Sfmt 4702 situations like this where potential M/ SI is fractional, consideration must be given to the lessened impacts anticipated due to the absence of M/SI in 6 of the 7 years and the fact that the single strike could be a male. Lastly, we reiterate that PBR is a conservative metric and also not sufficiently precise to serve as an absolute predictor of population effects upon which mortality caps would appropriately be based. This is especially important given the minor difference between zero and one across the 7-year period covered by this rulemaking, which is the smallest distinction possible when considering mortality. As noted above, Wade et al. (1998), authors of the paper from which the current PBR equation is derived, note that ‘‘Estimating incidental mortality in 1 year to be greater than the PBR calculated from a single abundance survey does not prove the mortality will lead to depletion; it identifies a population worthy of careful future monitoring and possibly indicates that mortality-mitigation efforts should be initiated.’’ The information included here indicates that the current population trend of this blue whale stock is unknown but likely approaching carrying capacity and has leveled off because of densitydependence, not human-caused mortality, in spite of what might be otherwise indicated from the calculated PBR. Further, potential (and proposed for authorization) M/SI is below 10 percent of PBR and management actions are in place to minimize vessel strike from other vessel activity in one of the highest-risk areas for strikes. Based on the presence of the factors described above, we do not expect lethal take from Navy activities, alone, to adversely affect Eastern North Pacific blue whales through effects on annual rates of recruitment or survival. Nonetheless, the fact that total human-caused mortality exceeds PBR necessitates close attention to the remainder of the impacts (i.e., harassment) on the Eastern North Pacific stock of blue whales from the Navy’s activities to ensure that the total authorized takes have a negligible impact on the species or stock. Therefore, this information will be considered in combination with our assessment of the impacts of proposed harassment takes in the Group and Species-Specific Analyses section that follows. Sei Whale (Eastern North Pacific Stock) For sei whales (Eastern North Pacific stock), PBR is currently set at 0.75. The total annual M/SI is estimated at greater than or equal to 0.2 in the 2022 final SAR, which reflects one strike over 5 E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules years, yielding a residual PBR of 0.55. However, more recent information suggests that the total annual M/SI reflected in the SAR may be overestimated because the one mortality considered in the calculation may not have been caused by a vessel strike. Carretta et al. (2021) elected to omit this strike from its report summarizing sources of human-related injury and mortality for U.S. Pacific west coast marine mammal stock assessments after reviewing the stranding narrative. The narrative indicated that the strike likely occurred post-mortem, evidenced by a lack of hemorrhaging in the whale’s tissues. NMFS proposes to authorize one M/SI for the Navy over the 7-year duration of the rule (indicated as 0.14 annually for the purposes of comparing to PBR and evaluating overall effects on annual rates of recruitment and survival), which means that residual PBR is 0.41 with the conservative inclusion of the likely post-mortem strike discussed above. We acknowledge that the 2023 vessel strike by the U.S. Navy could have been of a sei whale or a CA/OR/WA fin whale, and this strike is not quantitatively included in this PBR analysis (nor is it quantitatively included in the PBR analysis for CA/ OR/WA fin whale if both of the 2021 U.S. Navy strikes were fin whales) which rely on the 2022 final SARs. However, consideration of the 2023 strike would not change the total M/SI which NMFS compares to PBR, as the single strike from 2012–2016 used to calculate the vessel strike rate in the 2022 final SAR occurred in 2015 (which, as noted above, likely occurred post-mortem, and therefore, inclusion of this strike in the annual total M/SI is inherently conservative), and the 2023 U.S. Navy strike occurred outside of the 2012–2016 time period. Therefore, while we acknowledge the 2023 U.S. Navy strike, in the quantitative analysis it is treated the same as other non-U.S. Navy strikes that occurred outside of the timeframe reflected in the total M/SI (2012–2016). Immediately below, we explain the information that supports our finding that the Navy’s proposed authorized M/ SI is not expected to result in more than a negligible impact on this stock. As described previously, NMFS must also ensure that impacts by the applicant on the species or stock from other types of take (i.e., harassment) do not combine with the impacts from mortality to adversely affect the species or stock via impacts on annual rates of recruitment or survival, which occurs further below in the stock-specific conclusion sections. VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 Of note, management measures are in place to address M/SI caused by other activities. The Channel Islands NMS staff coordinates, collects, and monitors whale sightings in and around the Vessel Speed Reduction (VSR) zones and the Channel Islands NMS region. The seasonally established Southern California VSR zone spans from Point Arguello to Dana Point, including the Traffic Separation Schemes in the Santa Barbara Channel and San Pedro Channel. Vessels transiting the area from May 1 through December 15, 2023 are recommended to exercise caution and voluntarily reduce speed to 10 kn (18.5 km per hour) or less. While the VSR zone is aimed at reducing risk of fatal vessel strike of blue, humpback, and fin whales, this measure is also anticipated to reduce risk to sei whales (note, this is an expanded timeframe from the Whale Advisory Zone discussed in the 2020 HSTT final rule, which spanned June through November, though the effective period could change in future years). Channel Island NMS observers collect information from aerial surveys conducted by NOAA, the U.S. Coast Guard, California Department of Fish and Game, and U.S. Navy chartered aircraft. Information on seasonal presence, movement, and general distribution patterns of large whales is shared with mariners, NMFS Office of Protected Resources, U.S. Coast Guard, California Department of Fish and Game, the Santa Barbara Museum of Natural History, the Marine Exchange of Southern California, and whale scientists. Real time and historical whale observation data collected from multiple sources can be viewed on the Point Blue Whale Database. Further, as stated in the 2022 final SAR, the California swordfish drift gillnet fishery is the most likely U.S. fishery to interact with Eastern North Pacific sei whales, though there are zero estimated annual takes from this fishery given no observed entanglements from 1990–2016 across 8,845 monitored fishing sets (Carretta et al. (2018b)). NMFS established the Pacific Offshore Cetacean Take Reduction Team in 1996 and prepared an associated Plan (PCTRP) to reduce the risk of M/SI via fisheries interactions. In 1997, NMFS published final regulations formalizing the requirements of the PCTRP, including the use of pingers following several specific provisions and the employment of Skipper education workshops. In this case, 0.14 M/SI means one authorized mortality in 1 of the 7 years and zero authorized mortalities in 6 of those 7 years. Therefore, the Navy’s PO 00000 Frm 00045 Fmt 4701 Sfmt 4702 68333 authorized take would not be contributing to the total human-caused mortality at all in 6 of the 7, or 85.7 percent, of the years covered by this rulemaking. That means that even if a sei whale were to be struck, in 6 of the 7 years there could be no effect on annual rates of recruitment or survival from Navy-caused M/SI. Additionally, the loss of a male would have far less, if any, effect on population rates and absent any information suggesting that one sex is more likely to be struck than another, we can reasonably assume that there is a 50 percent chance that the single strike authorized by this rulemaking would be a male, thereby further decreasing the likelihood of impacts on the population rate. In situations like this where potential M/ SI is fractional, consideration must be given to the lessened impacts anticipated due to the absence of M/SI in 6 of the 7 years and the fact that the single strike could be a male. Lastly, we reiterate that PBR is a conservative metric and also not sufficiently precise to serve as an absolute predictor of population effects upon which mortality caps would appropriately be based. This is especially important given the minor difference between zero and one across the 7-year period covered by this rulemaking, which is the smallest distinction possible when considering mortality. As noted above, Wade et al. (1998), authors of the paper from which the current PBR equation is derived, note that ‘‘Estimating incidental mortality in 1 year to be greater than the PBR calculated from a single abundance survey does not prove the mortality will lead to depletion; it identifies a population worthy of careful future monitoring and possibly indicates that mortality-mitigation efforts should be initiated.’’ Even after qualitatively considering the possibility that the whale struck by Navy in 2023 was a sei whale, and based on the presence of the factors described above, we do not expect one authorized lethal take from Navy activities, alone, to adversely affect Eastern North Pacific sei whales through effects on annual rates of recruitment or survival. This information will be considered in combination with our assessment of the impacts of proposed harassment takes in the Group and Species-Specific Analyses section that follows. Group and Species-Specific Analyses In addition to broader analyses of the impacts of the Navy’s activities on mysticetes, odontocetes, and pinnipeds, the 2018 HSTT final rule contained detailed analyses of the effects of the E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68334 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules Navy’s activities in the HSTT Study Area on each affected species and stock and was updated, as appropriate, in the 2020 HSTT final rule. All of that information and analyses remain applicable and valid for our analyses of the effects of the same Navy activities on the same species and stocks, with the exception of humpback whale, for which the stock structure has been revised, and NMFS has updated its analyses accordingly for this proposed rule. See the Group and SpeciesSpecific Analyses subsection in the Analysis and Negligible Impact Determination section of the 2018 HSTT final rule (83 FR 66993–67018). In addition, apart from the additional proposed incidental take by vessel strike of two large whales, the resulting changes to the average annual mortality estimates discussed above, and the revised humpback whale stock structure, no new information has been received since the publication of the 2020 HSTT final rule that significantly changes the analyses of the effects of the Navy’s activities on each species and stock presented in the 2020 HSTT final rule (new information regarding vessel strike, the potential impact of the new gray whale UME, and the revised humpback whale stock structure were discussed earlier in the rule). In the discussions below, the estimated Level B harassment takes represent instances of take, not the number of individuals taken (the much lower and less frequent Level A harassment takes are far more likely to be associated with separate individuals), and in many cases, some individuals are expected to be taken more than one time while in other cases, a portion of individuals will not be taken at all. Below, we compare the total take numbers (including PTS, TTS, and behavioral disturbance) for species or stocks to their associated abundance estimates to evaluate the magnitude of impacts across the species or stock and to individuals. Specifically, when an abundance percentage comparison is below 100, it means that percentage or less of the individuals in the stock will be affected (i.e., some individuals will not be taken at all), that the average for those taken is 1 day per year, and that we would not expect any individuals to be taken more than a few times in a year. When it is more than 100 percent, it means there will definitely be some number of repeated takes of individuals. For example, if the percentage is 300, the average would be each individual is VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 taken on 3 days in a year if all were taken, but it is more likely that some number of individuals will be taken more than three times and some number of individuals fewer times or not at all. While it is not possible to know the maximum number of days across which individuals of a stock might be taken, in acknowledgement of the fact that it is more than the average, for the purposes of this analysis, we assume a number approaching twice the average. For example, if the percentage of take compared to the abundance is 800, we estimate that some individuals might be taken as many as 16 times. Those comparisons are included in the sections below. For some stocks, these numbers have been adjusted slightly (with these adjustments being in the single digits) so as to more consistently apply this approach, but these minor changes did not change the analysis or findings. To assist in understanding what this analysis means, we clarify a few issues related to estimated takes and the analysis here. An individual that incurs a PTS or TTS take may sometimes, for example, also be subject to behavioral disturbance at the same time. As described in the Harassment subsection of the Analysis and Negligible Impact Determination section of the 2018 HSTT final rule, the degree of PTS, and the degree and duration of TTS, expected to be incurred from the Navy’s activities are not expected to impact marine mammals such that their reproduction or survival could be affected. Similarly, data do not suggest that a single instance in which an animal accrues PTS or TTS and is also subjected to behavioral disturbance would result in impacts to reproduction or survival. Alternately, we recognize that if an individual is subjected to behavioral disturbance repeatedly for a longer duration and on consecutive days, effects could accrue to the point that reproductive success is jeopardized (as discussed below in the stock-specific summaries). Accordingly, in analyzing the number of takes and the likelihood of repeated and sequential takes (which could result in reproductive impacts), we consider the total takes, not just the Level B harassment takes by behavioral disturbance, so that individuals potentially exposed to both threshold shift and behavioral disturbance are appropriately considered. We note that the same reasoning applies with the potential addition of behavioral disturbance to tissue damage from PO 00000 Frm 00046 Fmt 4701 Sfmt 4702 explosives, the difference being that we do already consider the likelihood of reproductive impacts whenever tissue damage occurs. Further, the number of Level A harassment takes by either PTS or tissue damage are so low compared to abundance numbers that it is considered highly unlikely that any individual would be taken at those levels more than once. Having considered all of the information and analyses previously presented in the 2018 HSTT final rule, including the Group and SpeciesSpecific Analyses discussions organized by the different groups and species, below we present tables showing instances of total take as a percentage of stock abundance for each group, updated with the new vessel strike calculations and humpback stock structure. We then summarize the information for each species or stock, considering the analysis from the 2018 HSTT final rule, 2020 HSTT final rule, and any new analysis. The analyses below in some cases address species collectively if they occupy the same functional hearing group (i.e., low, mid, and high-frequency cetaceans and pinnipeds in water), share similar life history strategies, and/or are known to behaviorally respond similarly to acoustic stressors. Because some of these groups or species share characteristics that inform the impact analysis similarly, it would be duplicative to repeat the same analysis for each species or stock. In addition, animals belonging to each stock within a species typically have the same hearing capabilities and behaviorally respond in the same manner as animals in other stocks within the species. Mysticetes In table 12 and table 13 below for mysticetes, we indicate the total annual mortality, Level A harassment, and Level B harassment, and a number indicating the instances of total take as a percentage of abundance. Table 12 and table 13 have been updated from tables 18 and 19 in the 2020 HSTT final rule, as appropriate, with the 2022 final SARs and updated information on mortality, as discussed above. For additional information and analysis supporting the negligible-impact analysis, see the Mysticetes discussion in the Group and Species-Specific Analyses section of the 2018 HSTT final rule, all of which remains applicable to this proposed rule unless specifically noted. E:\FR\FM\03OCP2.SGM 03OCP2 68335 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules TABLE 12—ANNUAL ESTIMATED TAKES BY LEVEL B HARASSMENT, LEVEL A HARASSMENT, AND MORTALITY FOR MYSTICETES IN THE HRC PORTION OF THE HSTT STUDY AREA AND NUMBER INDICATING THE INSTANCES OF TOTAL TAKE AS A PERCENTAGE OF STOCK ABUNDANCE Total takes a Instances of indicated types of incidental take (not all takes represent separate individuals, especially for disturbance) Level B harassment Species Blue whale Bryde’s whale. Fin whale Humpback whale. Minke whale. Sei whale Level A harassment Stock Behavioral disturbance TTS (may also include disturbance) PTS Total takes (entire study area) Mortality b Tissue damage Abundance Takes (within Navy EEZ) Instance of total take as percent of abundance Total Navy abundance inside and outside of EEZ (HRC) Within EEZ Navy abundance (HRC) Total take as percentage of total Navy abundance (HRC) EEZ take as percentage of Navy EEZ abundance (HRC) Central North Pacific. Hawaii ..... 15 33 0 0 0 48 40 43 33 112 121 40 106 0 0 0 146 123 108 89 135 138 Hawaii ..... Hawaii ..... 21 2,837 27 6,289 0 3 0 0 0 0.29 48 9,129 41 7,389 52 5,078 40 4,595 92 180 103 161 Hawaii ..... 1,233 3,697 2 0 0 4,932 4,030 3,652 2,835 135 142 Hawaii ..... 46 121 0 0 0 167 135 138 107 121 126 Note: For the Hawaii take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule), both in and outside of the U.S. EEZ. Because the portion of the Navy’s study area inside the U.S. EEZ is generally concomitant with the area used to generate the abundance estimates in the SARs, and the abundance predicted by the same underlying density estimates is the preferred abundance to use, there is no need to separately compare the take to the SARs abundance estimate. a Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities. b The annual mortality of 0.29 is the result of no more than two mortalities over the course of 7 years from vessel strikes as described above in the Estimated Take of Marine Mammals section. TABLE 13—ANNUAL ESTIMATED TAKES BY LEVEL B HARASSMENT, LEVEL A HARASSMENT, AND MORTALITY FOR MYSTICETES IN THE SOCAL PORTION OF THE HSTT STUDY AREA AND NUMBER INDICATING THE INSTANCES OF TOTAL TAKE AS A PERCENTAGE OF STOCK ABUNDANCE Instances of indicated types of incidental take (not all takes represent separate individuals, especially for disturbance) Level B harassment Species Total takes (entire study Area) Stock Blue whale ......... Bryde’s whale .... Fin whale ........... Humpback whale Minke whale ...... Sei whale ........... Gray whale ........ Gray whale ........ ddrumheller on DSK120RN23PROD with PROPOSALS2 Level A harassment Eastern North Pacific. Eastern Tropical Pacific. CA/OR/WA ........ Central America/ Southern Mexico-CA/OR/WA. Mainland Mexico- CA/ OR/WA. CA/OR/WA ........ Eastern North Pacific. Eastern North Pacific. Western North Pacific. Total takes a Abundance Instance of total take as percent of abundance Navy abundance in action area (SOCAL) NMFS SARS abundance Total take as percentage of total Navy abundance in action area Total take as percentage of total SAR abundance Behavioral disturbance TTS (may also include disturbance) PTS Tissue damage 792 1,196 1 0 0.14 1,989 785 1,898 253 105 14 27 0 0 0 41 1.3 unknown 3,154 unknown 835 282 1,390 594 1 0 0 0 0.57 0 2,227 876 363 c 74 11,065 1,496 613 1,184 20 59 198 920 1 0 0.14 1,119 c 173 3,477 647 32 259 27 666 52 1 0 0 0 0 0.14 926 79 163 3 915 519 568 2,633 101 15 1,316 3,355 7 0 0.57 4,679 193 26,960 2,424 17 2 4 0 0 0 6 0 290 0 2 Mortality b Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule). a Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities. b The annual mortality of 0.14 is the result of no more than one mortality over the course of 7 years from vessel strikes as described above in the Estimated Take of Marine Mammals section. The annual mortality of 0.57 is the result of no more than four mortalities over the course of 7 years from vessel strikes. c In the 2020 HSTT final rule, NMFS reported a Navy abundance in Action Area (SOCAL) of 247 CA/OR/WA humpback whales. As explained in more detail in the Estimated Take from Vessel Strikes and Explosives by Serious Injury or Mortality, NMFS estimates that approximately 30 percent of the humpback whales off the coast of California may be from the Central America DPS with the remaining 70 percent are expected to be from the Mexico DPS. Therefore, of the estimated 247 humpback whales in SOCAL, NMFS anticipates that 74 would be of the Central America/Southern Mexico-CA/OR/WA stock (Central America DPS), and 173 would be of the Mainland Mexico-CA/OR/WA stock (Mexico DPS). VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 PO 00000 Frm 00047 Fmt 4701 Sfmt 4702 E:\FR\FM\03OCP2.SGM 03OCP2 68336 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules ddrumheller on DSK120RN23PROD with PROPOSALS2 Below we compile and summarize the information that supports our preliminary determination that the Navy’s activities would not adversely affect any species or stocks through effects on annual rates of recruitment or survival for any of the affected mysticete species and stocks. Blue Whale (Eastern North Pacific Stock) Blue whales are listed as endangered under the ESA, and the current population trend for the Eastern North Pacific stock is unknown. We further note that this stock was originally listed under the ESA as a result of the impacts from commercial whaling, which is no longer affecting the species. NMFS proposes to authorize one mortality over the 7 years covered by this rulemaking or 0.14 mortality annually. With the addition of this 0.14 annual mortality, residual PBR is exceeded, resulting in the total human-caused mortality exceeding PBR by 15.54. However, as described in more detail in the Serious Injury or Mortality section above, when total human-caused mortality exceeds PBR, we consider whether the incremental addition of a small amount of authorized mortality from the specified activity may still result in a negligible impact, in part by identifying whether it is less than 10 percent of PBR. In this case, the authorized mortality is well below 10 percent of PBR, management measures are in place to reduce mortality from other sources, and the incremental addition of a single mortality over the course of the 7-year Navy rule is not expected to, alone, lead to adverse impacts on the stock through effects on annual rates of recruitment or survival. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated total instances of take compared to the abundance (measured against both the Navy-estimated abundance and the SAR) is 253 and 105 percent, respectively (table 13). Given the range of blue whales, this information suggests that only some portion of individuals in the stock are likely impacted, but that there will likely be some repeat exposure (maybe 5 or 6 days within a year) of some subset of individuals that spend extended time within SOCAL. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB with a portion up to 178 dB (i.e., of a moderate or lower level, less likely to evoke a VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 severe response). Additionally, the Navy implements time/area mitigation in SOCAL in the majority of the BIAs, which will reduce the severity of impacts to blue whales by reducing interference in feeding that could result in lost feeding opportunities or necessitate additional energy expenditure to find other good opportunities. Regarding the severity of TTS takes, we have explained in the 2018 HSTT final rule that they are expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere with blue whale communication or other important low-frequency cues— and that the associated lost opportunities and capabilities are not at a level that would impact reproduction or survival. For similar reasons (as described in the 2018 HSTT final rule) the single estimated Level A harassment take by PTS for this stock is unlikely to have any effect on the reproduction or survival of that one individual, even if it were to be experienced by an animal that also experiences one or more Level B harassment takes by behavioral disturbance. Altogether, only a small portion of the stock is anticipated to be impacted and any individual blue whale is likely to be disturbed at a low-moderate level, with likely many animals exposed only once or twice and a subset potentially disturbed across 5 or 6 days but minimized in biologically important areas. This low magnitude and severity of harassment effects is not expected to result in impacts on the reproduction or survival of any individuals and, therefore, when combined with the proposed authorized mortality (which our earlier analysis indicated would not, alone, have more than a negligible impact on this stock of blue whales), the total take is not expected to adversely affect this stock through impacts on annual rates of recruitment or survival. For these reasons, we have preliminarily determined, in consideration of all of the effects of the Navy’s activities combined, that the authorized take proposed would have a negligible impact on the Eastern North Pacific stock of blue whales. percent; however, the abundance upon which this percentage is based (1.3 whales from the Navy estimate, which is extrapolated from density estimates based on very few sightings) is clearly erroneous and the SAR does not include an abundance estimate because all of the survey data is outdated (table 13). However, the abundance in the early 1980s was estimated as 22,000 to 24,000, a portion of the stock was estimated at 13,000 in 1993, and the minimum number in the Gulf of California was estimated at 160 in 1990. Given this information and the fact that 41 total takes of Bryde’s whales were estimated, this information suggests that only a small portion of the individuals in the stock are likely impacted, and few, if any, are likely taken over more than 1 day. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB with a portion up to 178 dB (i.e., of a moderate or lower level, less likely to evoke a severe response). Regarding the severity of TTS takes, they are expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere with Bryde’s whale communication or other important lowfrequency cues. Any associated lost opportunities and capabilities are not at a level that would impact reproduction or survival. Altogether, only a small portion of the stock is anticipated to be impacted and any individual Bryde’s whale is likely to be disturbed at a low-moderate level, with few, if any, individuals exposed over more than 1 day in the year. This low magnitude and severity of harassment effects is not expected to result in impacts on individual reproduction or survival, much less annual rates of recruitment or survival. For these reasons, we have preliminarily determined, in consideration of all of the effects of the Navy’s activities combined, that the authorized take proposed would have a negligible impact on the Eastern Tropical Pacific stock of Bryde’s whales. Bryde’s Whale (Eastern Tropical Pacific Stock) Little is known about this stock or its status, and it is not listed under the ESA. No mortality or Level A harassment is anticipated or proposed to be authorized. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated total instances of take compared to the abundance is 3,154 Fin Whale (CA/OR/WA Stock) The SAR identifies this stock as ‘‘increasing,’’ even though the larger species is listed as endangered under the ESA. NMFS proposes to authorize four mortalities over the 7 years covered by this rulemaking, or 0.57 mortality annually. The addition of this 0.57 annual mortality still leaves the total human-caused mortality well under residual PBR. PO 00000 Frm 00048 Fmt 4701 Sfmt 4702 E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules We acknowledge the 2021 vessel strike of two fin whales by the Royal Australian Navy, and that the 2021 and 2023 vessel strikes by the U.S. Navy could have been CA/OR/WA fin whales. While the Royal Australian Navy strikes are not quantitatively included in the estimated take by vessel strike, even if they were, and if we presumed that the 2021 and 2023 U.S. Navy strikes were all fin whales, M/SI of this stock would still fall well below PBR (80). Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated total instances of take compared to the abundance (measured against both the Navy-estimated abundance and the SAR) is 613 and 20 percent, respectively (table 13). This information suggests that only some portion (less than 25 percent) of individuals in the stock are likely impacted but that there is likely some repeat exposure (perhaps up to 12 days within a year) of some subset of individuals that spend extended time within the SOCAL complex. Some of these takes could occur on a few sequential days for some small number of individuals, for example, if they resulted from a multi-day exercise on a range while individuals were in the area for multiple days feeding. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB with a portion up to 178 dB (i.e., of a moderate or lower level, less likely to evoke a severe response). Additionally, while there are no known BIAs for fin whales in the SOCAL range, the Navy implements time/area mitigation in SOCAL in blue whale BIAs, and fin whales are known to sometimes feed in some of the same areas, which means they could potentially accrue some benefits from the mitigation. Regarding the severity of TTS takes, they are expected to be lowlevel, of short duration, and mostly not in a frequency band that would be expected to interfere with fin whale communication or other important lowfrequency cues—and that the associated lost opportunities and capabilities are not at a level that would impact reproduction or survival. For similar reasons (as described in the 2018 HSTT final rule) the single estimated Level A harassment take by PTS for this stock is unlikely to have any effects on the reproduction or survival of that one individual. Altogether, this population is increasing, only a small portion of the stock is anticipated to be impacted, and VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 any individual fin whale is likely to be disturbed at a low-moderate level, with the taken individuals likely exposed between 1 and 12 days, with a few individuals potentially taken on a few sequential days. This low magnitude and severity of harassment effects is not expected to result in impacts on individual reproduction or survival, and therefore, when combined with the proposed authorized mortality (which our earlier analysis indicated would not, alone, have more than a negligible impact on this stock of fin whales), the total take is not expected to adversely affect this stock through impacts on annual rates of recruitment or survival. For these reasons, we have preliminarily determined, in consideration of all of the effects of the Navy’s activities combined, that the authorized take proposed would have a negligible impact on the CA/OR/WA stock of fin whales. Humpback Whale (Central America/ Southern Mexico-CA/OR/WA Stock) The SAR identifies this stock as increasing, though the growth rate is uncertain. Animals in this stock are of the Central America DPS which is designated as endangered under the ESA. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated total instances of take compared to the abundance (measured against both the Navy-estimated abundance and the SAR) is 1,184 and 59 percent, respectively (table 11). Given the range of humpback whales, this information suggests that only some portion of individuals in the stock are likely impacted but that there is likely some repeat exposure (perhaps up to 23 days within a year) of some subset of individuals that spend extended time within the SOCAL complex. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB with a portion up to 178 dB (i.e., of a moderate or lower level, less likely to evoke a severe response). Some of these takes could occur on several sequential days for some small number of individuals, for example, if they resulted from a multi-day exercise on a range while individuals were in the area for multiple days feeding. However, in these amounts, it would still not be expected to adversely impact reproduction or survival of any individuals. PO 00000 Frm 00049 Fmt 4701 Sfmt 4702 68337 Regarding the severity of TTS takes, they are expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere with humpback whale communication or other important lowfrequency cues—and that the associated lost opportunities and capabilities are not at a level that would impact reproduction or survival. Altogether, only a small portion of the stock is anticipated to be impacted and any individual humpback whale is likely to be disturbed at a low-moderate level, with likely many animals exposed only once or twice and a subset potentially disturbed up to 23 days, but with no reason to think that more than a few of those days would be sequential. This low magnitude and severity of harassment effects is not expected to result in impacts on the reproduction or survival of any individuals and, therefore, the total take is not expected to adversely affect this stock through impacts on annual rates of recruitment or survival. For these reasons, we have preliminarily determined, in consideration of all of the effects of the Navy’s activities combined, that the authorized take proposed would have a negligible impact on the Central America/Southern Mexico-CA/OR/WA stock of humpback whales. Humpback Whale (Mainland MexicoCA/OR/WA Stock) The status of this stock is unknown. Animals in this stock are of the Mexico DPS which is designated as threatened under the ESA. NMFS proposes to authorize one mortality over the 7 years covered by this rulemaking, or 0.14 mortality annually. The addition of this 0.14 annual mortality still leaves the total human-caused mortality well under residual PBR. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated total instances of take compared to the abundance (measured against both the Navy-estimated abundance and the SAR) is 647 and 32 percent, respectively (table 13). Given the range of humpback whales, this information suggests that only some portion of individuals in the stock are likely impacted but that there is likely some repeat exposure (perhaps up to 13 days within a year) of some subset of individuals that spend extended time within the SOCAL complex. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB with a portion up to 178 E:\FR\FM\03OCP2.SGM 03OCP2 68338 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules ddrumheller on DSK120RN23PROD with PROPOSALS2 dB (i.e., of a moderate or lower level, less likely to evoke a severe response). Some of these takes could occur on several sequential days for some small number of individuals, for example, if they resulted from a multi-day exercise on a range while individuals were in the area for multiple days feeding. However, in these amounts, it would still not be expected to adversely impact reproduction or survival of any individuals. Regarding the severity of TTS takes, they are expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere with humpback whale communication or other important lowfrequency cues—and that the associated lost opportunities and capabilities are not at a level that would impact reproduction or survival. For similar reasons (as described in the 2018 HSTT final rule) the single estimated Level A harassment take by PTS for this stock is unlikely to have any effects on the reproduction or survival of that one individual. Altogether, only a small portion of the stock is anticipated to be impacted and any individual humpback whale is likely to be disturbed at a low-moderate level, with likely many animals exposed only once or twice and a subset potentially disturbed up to 13 days, but with no reason to think that more than a few of those days would be sequential. This low magnitude and severity of harassment effects is not expected to result in impacts on the reproduction or survival of any individuals and, therefore, when combined with the proposed authorized mortality (which our earlier analysis indicated would not, alone, have more than a negligible impact on this stock of humpback whales), the total take is not expected to adversely affect this stock through impacts on annual rates of recruitment or survival. For these reasons, we have preliminarily determined, in consideration of all of the effects of the Navy’s activities combined, that the authorized take proposed would have a negligible impact on the CA/OR/WA stock of humpback whales. Minke Whale (CA/OR/WA Stock) The status of this stock is unknown and it is not listed under the ESA. No mortality from vessel strike or tissue damage from explosive exposure is anticipated or proposed for authorization for this species. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated total instances of take compared to the abundance (measured against both the Navy- VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 estimated abundance and the SAR) is 568 and 101 percent, respectively (table 11). Based on the behaviors of minke whales, which often occur along continental shelves and sometimes establish home ranges along the West Coast, this information suggests that only a portion of individuals in the stock are likely impacted but that there is likely some repeat exposure (perhaps up to 11 days within a year) of some subset of individuals that spend extended time within the SOCAL complex. Some of these takes could occur on a few sequential days for some small number of individuals, for example, if they resulted from a multiday exercise on a range while individuals were in the area for multiple days feeding. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB with a portion up to 178 dB (i.e., of a moderate or lower level, less likely to evoke a severe response). Regarding the severity of TTS takes, they are expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere with minke whale communication or other important lowfrequency cues—and that the associated lost opportunities and capabilities are not at a level that would impact reproduction or survival. For similar reasons (as described in the 2018 HSTT final rule) the single estimated Level A harassment take by PTS for this stock is unlikely to have any effects on the reproduction or survival of that individual. Altogether, only a portion of the stock is anticipated to be impacted and any individual minke whale is likely to be disturbed at a low-moderate level, with the taken individuals likely exposed between 1 and 11 days, with a few individuals potentially taken on a few sequential days. This low magnitude and severity of harassment effects is not expected to result in impacts on individual reproduction or survival, much less annual rates of recruitment or survival. For these reasons, we have preliminarily determined, in consideration of all of the effects of the Navy’s activities combined, that the authorized take proposed would have a negligible impact on the CA/OR/WA stock of minke whales. Sei Whale (Eastern North Pacific Stock) The status of this stock is unknown, and sei whales are listed under the ESA. NMFS proposes to authorize one mortality over the 7 years covered by PO 00000 Frm 00050 Fmt 4701 Sfmt 4702 this rulemaking or 0.14 mortality annually. The addition of this 0.14 annual mortality still leaves the total human-caused mortality under residual PBR. After additionally considering several qualitative factors described above, including that the 2023 strike could have been a sei whale (or fin whale), we do not expect one authorized lethal take from Navy activities, alone, to adversely affect Eastern North Pacific sei whales through effects on annual rates of recruitment or survival. No Level A harassment is anticipated or proposed for authorization. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated total instances of take compared to the abundance (measured against both the Navy-estimated abundance and the SAR) is 2,633 and 15 percent, respectively (table 13), however, the abundance upon which the Navy percentage is based (3 from the Navy estimate, which is extrapolated from density estimates based on very few sightings) is likely an underestimate of the number of individuals in the HSTT study Area, resulting in an overestimated percentage. Given this information and the large range of sei whales, and the fact that only 79 total Level B harassment takes of sei whales were estimated, it is likely that some very small number of sei whales would be taken repeatedly, potentially up to 15 days in a year (typically 2,633 percent would lead to the estimate of 52 days/ year, however, given that there are only 79 sei whale total takes, we used the conservative assumption that five individuals might be taken up to 15 times, with the few remaining takes distributed among other individuals). Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB with a portion up to 178 dB (i.e., of a moderate or lower level, less likely to evoke a severe response). Some of these takes could occur on a few sequential days for some small number of individuals, for example, if they resulted from a multi-day exercise on a range while individuals were in the area for multiple days feeding, however, in these amounts it would still not be expected to adversely impact reproduction or survival of any individuals. Regarding the severity of TTS takes, they are expected to be lowlevel, of short duration, and mostly not in a frequency band that would be expected to interfere with sei whale E:\FR\FM\03OCP2.SGM 03OCP2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules ddrumheller on DSK120RN23PROD with PROPOSALS2 communication or other important lowfrequency cues—and that the associated lost opportunities and capabilities are not at a level that would impact reproduction or survival. Altogether, only a small portion of the stock is anticipated to be impacted and any individual sei whale is likely to be disturbed at a low-moderate level, with only a few individuals exposed over one to 15 days in a year, with no more than a few sequential days. This low magnitude and severity of harassment effects is not expected to result in impacts on individual reproduction or survival, and therefore, when combined with the proposed authorized mortality (which our earlier analysis indicated would not, alone, have more than a negligible impact on this stock of sei whales), the total take is not expected to adversely affect this stock through impacts on annual rates of recruitment or survival. For these reasons, we have preliminarily determined, in consideration of all of the effects of the Navy’s activities combined, that the authorized take proposed would have a negligible impact on the Eastern North Pacific stock of sei whales. Gray Whale (Eastern North Pacific Stock) The Eastern North Pacific stock of gray whale is not ESA-listed and the SAR indicates that the stock is increasing. However, recent (2021– 2022) surveys conducted by NMFS’ Southwest Fisheries Science Center estimated that the population has declined to 16,650 whales, though the authors note that this stock has historically shown a pattern of population growth and decline that has not impacted the population in the long term (Eguchi et al. 2022). NMFS is proposing to authorize four mortalities over the 7 years covered by this rulemaking, or 0.57 mortality annually. The addition of this 0.57 annual mortality still leaves the total humancaused mortality well under the insignificance threshold of residual PBR (670). On May 31, 2019, NMFS declared the unusual spike in strandings of gray whales along the west coast of North America since January 1, 2019 an UME. As of June 25, 2023, 674 gray whales have stranded along the west coast of North America (in the U.S., Canada, and Mexico) under this UME. Given the small number of takes by serious injury or mortality proposed for authorization, the proposed takes are not anticipated to exacerbate the ongoing UME. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated total instances of take compared to the VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 abundance (measured against both the Navy-estimated abundance and the SAR) is 2,424 and 16 percent, respectively (table 13). (Note that in comparison to the recent Eguchi et al. 2022 abundance estimate, the number of estimated total instances of take compared to the abundance would be 28 percent.) This information suggests that only some small portion of individuals in the stock are likely impacted (less than 17 percent) but that there is likely some level of repeat exposure of some subset of individuals that spend extended time within the SOCAL complex. Typically 2,424 percent would lead to the estimate of 48 days/year, however, given that a large number of gray whales are known to migrate through the SOCAL complex and the fact that there are 4,679 total takes, we believe that it is more likely that a larger number of individuals would be taken one to a few times, while a small number staying in an area to feed for several days may be taken on 5–10 days. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB with a portion up to 178 dB (i.e., of a moderate or lower level, less likely to evoke a severe response). Some of these takes could occur on a couple of sequential days for some small number of individuals; however, in these amounts it would still not be expected to adversely impact reproduction or survival of any individuals. Regarding the severity of TTS takes, they are expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere with gray whale communication or other important lowfrequency cues and that the associated lost opportunities and capabilities are not at a level that would impact reproduction or survival. For these same reasons (low level and frequency band), while a small permanent loss of hearing sensitivity may include some degree of energetic costs for compensating or may mean some small loss of opportunities or detection capabilities, at the expected scale the seven estimated Level A harassment takes by PTS for gray whales would be unlikely to impact behaviors, opportunities, or detection capabilities to a degree that would interfere with reproductive success or survival of any individuals. Altogether, we have considered the impacts of the gray whale UME, the Eastern North Pacific stock of gray whales is not endangered or threatened PO 00000 Frm 00051 Fmt 4701 Sfmt 4702 68339 under the ESA. The SAR indicates that the stock is increasing. However, recent (2021–2022) surveys conducted by NMFS’ Southwest Fisheries Science Center estimated that the population has declined (Eguchi et al. 2022). Only a small portion of the stock is anticipated to be impacted and any individual gray whale is likely to be disturbed at a lowmoderate level, with likely many animals exposed only once or twice and a subset potentially disturbed across 5 to 10 days. This low magnitude and severity of harassment effects is not expected to result in impacts to reproduction or survival for any individuals and, therefore, when combined with the proposed authorized mortality of four whales over the 7 year period (which our earlier analysis indicated would not, alone, have more than a negligible impact on this stock of gray whales), the total take is not expected to adversely affect this stock through impacts on annual rates of recruitment or survival. For these reasons, we have preliminarily determined, in consideration of all of the effects of the Navy’s activities combined, that the authorized take proposed would have a negligible impact on the Eastern North Pacific stock of gray whales. Gray Whale (Western North Pacific stock) The Western North Pacific stock of gray whales is reported as increasing in the 2022 final SAR but is listed as endangered under the ESA. No mortality or Level A harassment is anticipated or proposed for authorization. This stock is expected to incur the very small number of 6 Level B harassment takes (2 behavioral disruption and 4 TTS) to a stock with a SAR-estimated abundance of 290 (table 11). These takes will likely accrue to different individuals, the behavioral disturbances will be of a low-moderate level, and the TTS instances will be at a low level and short duration. This low magnitude and severity of harassment effects is not expected to result in impacts on individual reproduction or survival, much less to adversely affect this stock through impacts on annual rates of recruitment or survival. For these reasons, we have preliminarily determined, in consideration of all of the effects of the Navy’s activities combined, that the authorized take proposed would have a negligible impact on the Western North Pacific stock of gray whales. Humpback Whale (Hawaii Stock) The status of this stock is unknown. Animals in this stock are of the Hawaii E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68340 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules DPS which is not listed under the ESA. No Level A harassment by tissue damage is proposed for authorization. NMFS proposes to authorize two mortalities over the 7 years covered by this rulemaking, or 0.29 mortalities annually. The addition of this 0.29 annual mortality still leaves the total human-caused mortality well under the insignificance threshold for residual PBR. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated instances of take compared to the abundance, both throughout the HSTT Study Area and within the U.S. EEZ, respectively, is 180 and 161 percent (table 12). This information and the complicated far-ranging nature of the stock structure suggests that some portion of the stock (but not all) are likely impacted, over 1 to several days per year, with little likelihood of take across sequential days. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB with a portion up to 178 dB (i.e., of a moderate or lower level, less likely to evoke a severe response). Additionally, as noted above, there are two mitigation areas implemented by the Navy that span a large area of the important humpback reproductive area (BIA) and minimize impacts by limiting the use of MF1 active sonar and explosives, thereby reducing both the number and severity of takes of humpback whales. Regarding the severity of TTS takes, they are expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere with humpback whale communication or other important low-frequency cues, and that the associated lost opportunities and capabilities are not at a level that would impact reproduction or survival. For these same reasons (low level and frequency band), while a small permanent loss of hearing sensitivity may include some degree of energetic costs for compensating or may mean some small loss of opportunities or detection capabilities, at the expected scale the 3 estimated Level A harassment takes by PTS for humpback whales would be unlikely to impact behaviors, opportunities, or detection capabilities to a degree that would interfere with reproductive success or survival of any individuals. VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 Altogether, this stock’s status is unknown and the DPS is not listed as endangered or threatened under the ESA. Only a small portion of the stock is anticipated to be impacted and any individual humpback whale is likely to be disturbed at a low-moderate level, with the taken individuals likely exposed between 1 to several days per year, with little likelihood of take across sequential days. This low magnitude and severity of harassment effects is not expected to result in impacts on individual reproduction or survival, and therefore, when combined with the proposed authorized mortality (which our earlier analysis indicated would not, alone, have more than a negligible impact on this stock of humpback whales), the total take is not expected to adversely affect this stock through effects on annual rates of recruitment or survival. For these reasons, we have preliminarily determined, in consideration of all of the effects of the Navy’s activities combined, that the authorized take proposed would have a negligible impact on the Hawaii stock of humpback whales. Blue Whale (Central North Pacific Stock) and the Hawaii Stocks of Bryde’s Whale, Fin Whale, Minke Whale, and Sei Whale The status of these stocks are not identified in the SARs. Blue whale (Central North Pacific stock) and the Hawaii stocks of fin whale and sei whale are listed as endangered under the ESA; the Hawaii stocks of minke whales and Bryde’s whales are not listed under the ESA. No mortality or Level A harassment by tissue damage is anticipated or proposed for authorization for any of these stocks. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated instances of take compared to the abundance, both throughout the HSTT Study Area and within the U.S. EEZ, respectively, is 92–135 and 103–142 percent (table 12). This information suggests that some portion of the stocks (but not all) are likely impacted, over 1 to several days per year, with little likelihood of take across sequential days. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB with a portion up to 178 dB (i.e., of a moderate or lower level, less likely to evoke a severe response). PO 00000 Frm 00052 Fmt 4701 Sfmt 4702 Regarding the severity of TTS takes, they are expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere with mysticete communication or other important lowfrequency cues—and that the associated lost opportunities and capabilities are not at a level that would impact reproduction or survival. For similar reasons (as described in the 2018 HSTT final rule) the two estimated Level A harassment takes by PTS for the Hawaii stock of minke whales are unlikely to have any effects on the reproduction or survival of any individuals. Altogether, only a portion of these stocks are anticipated to be impacted and any individuals of these stocks are likely to be disturbed at a low-moderate level, with the taken individuals likely exposed between 1 and several days, with little chance that any are taken across sequential days. This low magnitude and severity of harassment effects is not expected to result in impacts on individual reproduction or survival, much less have impacts on annual rates of recruitment or survival. For these reasons, we have preliminarily determined, in consideration of all of the effects of the Navy’s activities combined, that the authorized take proposed would have a negligible impact on these stocks. Odontocetes Sperm Whale, Dwarf Sperm Whale, and Pygmy Sperm Whale In table 14 and table 15 below for sperm whale, dwarf sperm whale, and pygmy sperm whale, we indicate the total annual mortality (0 for all stocks; the 2020 HSTT final rule included 0.14 annual takes by mortality of the Hawaii stock of sperm whale), Level A and Level B harassment, and a number indicating the instances of total take as a percentage of abundance. Table 14 and table 15 are unchanged from tables 20 and 21 in the 2020 HSTT final rule, except for updated information on mortality for the Hawaii stock of sperm whales, as discussed above. For additional information and analysis supporting the negligible-impact analysis, see the Odontocetes discussion as well as the Sperm Whales, Dwarf Sperm Whales, and Pygmy Sperm Whales discussion in the Group and Species-Specific Analyses section of the 2018 HSTT final rule, all of which remains applicable to this proposed rule unless specifically noted. E:\FR\FM\03OCP2.SGM 03OCP2 68341 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules TABLE 14—ANNUAL ESTIMATED TAKES BY LEVEL B HARASSMENT, LEVEL A HARASSMENT, AND MORTALITY FOR SPERM WHALES, DWARF SPERM WHALES, AND PYGMY SPERM WHALES IN THE HRC PORTION OF THE HSTT STUDY AREA AND NUMBER INDICATING THE INSTANCES OF TOTAL TAKE AS A PERCENTAGE OF STOCK ABUNDANCE Instances of indicated types of incidental take (not all takes represent separate individuals, especially for disturbance) Level B harassment Species Dwarf sperm whale. Pygmy sperm whale. Sperm whale. Total takes Level A harassment Stock Total takes (entire study area) Mortality Abundance Takes (within NAVY EEZ) Instances of total take as percent of abundance Total Navy abundance inside and outside EEZ (HRC) Within EEZ Navy abundance (HRC) Total take as percentage of total Navy abundance (HRC) EEZ take as percentage of EEZ abundance (HRC) Behavioral disturbance TTS (may also include disturbance) PTS Hawaii .... 5,870 14,550 64 0 0 20,484 15,310 8,218 6,379 249 240 Hawaii .... 2,329 5,822 29 0 0 8,180 6,098 3,349 2,600 244 235 Hawaii .... 2,466 30 0 0 0 2,496 1,317 1,656 1,317 151 147 Tissue damage Note: For the Hawaii take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule), both in and outside of the U.S. EEZ. Because the portion of the Navy’s study area inside the U.S. EEZ is generally concomitant with the area used to generate the abundance estimates in the SARs, and the abundance predicted by the same underlying density estimates is the preferred abundance to use, there is no need to separately compare the take to the SARs abundance estimate. Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities. TABLE 15—ANNUAL ESTIMATED TAKES BY LEVEL B HARASSMENT, LEVEL A HARASSMENT, AND MORTALITY FOR SPERM WHALES, DWARF SPERM WHALES, AND PYGMY SPERM WHALES IN THE SOCAL PORTION OF THE HSTT STUDY AREA AND NUMBER INDICATING THE INSTANCES OF TOTAL TAKE AS A PERCENTAGE OF STOCK ABUNDANCE Instances of indicated types of incidental take (not all takes represent separate individuals, especially for disturbance) Level B harassment Species Kogia whales ... Sperm whale ... Level A harassment Stock CA/OR/WA ...... CA/OR/WA ...... Total takes Total takes (entire study area) Mortality Behavioral disturbance TTS (may also include disturbance) PTS 2,779 2,437 6,353 56 38 0 Tissue damage 0 0 Abundance 0 0 Instances of total take as percent of abundance Navy abundance in action area NMFS SARS abundance 757 273 4,111 1,997 9,170 2,493 Total take as percentage of total Navy abundance in Action Area Total take as percentage of total SAR abundance 1,211 913 223 125 Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule). Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities. Below we compile and summarize the information that supports our preliminary determination that the Navy’s activities would not adversely affect any species or stocks through effects on annual rates of recruitment or survival for any of the affected species and stocks addressed in this section. ddrumheller on DSK120RN23PROD with PROPOSALS2 Sperm Whale, Dwarf Sperm Whale, and Pygmy Sperm Whale (CA/OR/WA Stocks) The SAR identifies the CA/OR/WA stock of sperm whales as ‘‘stable’’, and the species is listed as endangered under the ESA. The status of the CA/ OR/WA stocks of pygmy and dwarf sperm whales is unknown and neither are listed under the ESA. Neither mortality nor Level A harassment by tissue damage from exposure to explosives is expected or proposed for VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 authorization for any of these three stocks. Due to their pelagic distribution, small size, and cryptic behavior, pygmy sperm whales and dwarf sperm whales are rarely sighted during at-sea surveys and are difficult to distinguish between when visually observed in the field. Many of the relatively few observations of Kogia spp. off the U.S. West Coast were not identified to species. All at-sea sightings of Kogia spp. have been identified as pygmy sperm whales or Kogia spp. Stranded dwarf sperm and pygmy sperm whales have been found on the U.S. West Coast, however dwarf sperm whale strandings are rare. NMFS SARs suggest that the majority of Kogia sighted off the U.S. West Coast were likely pygmy sperm whales. As such, the stock estimate in the NMFS SAR for pygmy sperm whales is the estimate derived for all Kogia spp. in the region PO 00000 Frm 00053 Fmt 4701 Sfmt 4702 (Barlow, 2016), and no separate abundance estimate can be determined for dwarf sperm whales, though some low number likely reside in the U.S. EEZ. Due to the lack of abundance estimate, it is not possible to predict the take of dwarf sperm whales and take estimates are identified as Kogia spp. (including both pygmy and dwarf sperm whales). We assume only a small portion of those takes are likely to be dwarf sperm whales as the density and abundance in the U.S. EEZ is thought to be low. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated total instances of take compared to the abundance (measured against both the Navy-estimated abundance and the SAR) is, respectively, 913 and 125 for sperm whales and 1,211 and 223 for Kogia spp., with a large proportion of E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68342 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules these anticipated to be pygmy sperm whales due to the low abundance and density of dwarf sperm whales in the HSTT Study Area. (Table 15). Given the range of these stocks (which extends the entire length of the West Coast, as well as beyond the U.S. EEZ boundary), this information suggests that some portion of the individuals in these stocks will not be impacted but that there is likely some repeat exposure (perhaps up to 24 days within a year for Kogia spp. and 18 days a year for sperm whales) of some small subset of individuals that spend extended time within the SOCAL Range. Additionally, while interrupted feeding bouts are a known response and concern for odontocetes, we also know that there are often viable alternative habitat options in the relative vicinity. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB (i.e., of a lower, to occasionally moderate, level and less likely to evoke a severe response). However, some of these takes could occur on a fair number of sequential days for some number of individuals. Regarding the severity of TTS takes, they are expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere with sperm whale communication or other important lowfrequency cues, and that the associated lost opportunities and capabilities are not at a level that would impact reproduction or survival. For these same reasons (low level and frequency band), while a small permanent loss of hearing sensitivity (PTS) may include some degree of energetic costs for compensating or may mean some small loss of opportunities or detection capabilities, at the expected scale the estimated Level A harassment takes by PTS for the dwarf and pygmy sperm whale stocks would be unlikely to impact behaviors, opportunities, or detection capabilities to a degree that would interfere with reproductive success or survival of any individuals. Thus, the 38 total Level A harassment takes by PTS for these two stocks would be unlikely to affect rates of recruitment and survival for the stocks. Altogether, most members of the stocks will likely be taken by Level B harassment (at a low to occasionally moderate level) over several days a year, and some smaller portion of the stocks are expected to be taken on a relatively moderate to high number of days (up to 18 or 24) across the year, some of which could be sequential days. Though the VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 majority of impacts are expected to be of a lower to sometimes moderate severity, the larger number of takes for a subset of individuals makes it more likely that a small number of individuals could be interrupted during foraging in a manner and amount such that impacts to the energy budgets of females (from either losing feeding opportunities or expending considerable energy to find alternative feeding options) could cause them to forego reproduction for a year. Energetic impacts to males are generally meaningless to population rates unless they cause death, and it takes extreme energy deficits beyond what would ever be likely to result from these activities to cause the death of an adult marine mammal. As discussed in the 2020 HSTT final rule, however, foregone reproduction (especially for 1 year, which is the maximum predicted because the small number anticipated in any 1 year makes the probability that any individual would be impacted in this way twice in 7 years very low) has far less of an impact on population rates than mortality and a small number of instances of foregone reproduction would not be expected to adversely affect these stocks through effects on annual rates of recruitment or survival. We also note that residual PBR is 19 for pygmy sperm whales and 1.9 for sperm whales. Both the abundance and PBR are unknown for dwarf sperm whales, however, we know that take of this stock is likely significantly lower in magnitude and severity (i.e., lower number of total takes and repeated takes any individual) than pygmy sperm whales. For these reasons, in consideration of all of the effects of the Navy’s activities combined, we have preliminarily determined that the authorized take proposed would have a negligible impact on the CA/OR/WA stocks of sperm whales and pygmy and dwarf sperm whales. Sperm Whale (Hawaii Stock) The SAR does not identify a trend for this stock and the species is listed as endangered under the ESA. No mortality or Level A harassment by PTS or tissue damage is expected or proposed for authorization. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated instances of take compared to the abundance, both throughout the HSTT Study Area and within the U.S. EEZ, respectively, is 151 and 147 percent (table 14). This information and the sperm whale stock range suggest that likely only a smaller portion of the stock would be impacted, over 1 to several PO 00000 Frm 00054 Fmt 4701 Sfmt 4702 days per year, with little likelihood of take across sequential days. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB (i.e., of a lower, to occasionally moderate, level and less likely to evoke a severe response). Regarding the severity of TTS takes, they are expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere with sperm whale communication or other important lowfrequency cues, and that the associated lost opportunities and capabilities are not at a level that would impact reproduction or survival. Altogether, a relatively small portion of this stock is anticipated to be impacted and any individuals are likely to be disturbed at a low-moderate level, with the taken individuals likely exposed between 1 and several days, with little chance that any are taken across sequential days. This low magnitude and severity of harassment effects is not expected to result in impacts on individual reproduction or survival, much less annual rates of recruitment or survival. For these reasons, we have preliminarily determined, in consideration of all of the effects of the Navy’s activities combined, that the authorized take proposed would have a negligible impact on the Hawaii stock of sperm whales. Pygmy and Dwarf Sperm Whales (Hawaii Stocks) The SAR does not identify a trend for these stocks and the species are not listed under the ESA. No Level A harassment by tissue damage is anticipated or proposed for authorization. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated instances of take compared to the abundance, both throughout the HSTT Study Area and within the U.S. EEZ, respectively, is 244–249 and 235– 240 percent (table 12). This information and the pygmy and dwarf sperm whale stock ranges (at least throughout the U.S. EEZ around the entire Hawaiian Islands) suggest that likely a fair portion of each stock is not impacted, but that a subset of individuals may be taken over one to perhaps 5 days per year, with little likelihood of take across sequential days. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to E:\FR\FM\03OCP2.SGM 03OCP2 68343 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB (i.e., of a lower, to occasionally moderate, level and less likely to evoke a severe response). Additionally, as discussed earlier, within the Hawaii Island Mitigation Area, explosives are not used and the use of MF1 and MF4 active sonar is limited, greatly reducing the severity of impacts within the small and resident population BIA for dwarf sperm whales (Kratofil et al., 2023), which is entirely contained within this mitigation area. Regarding the severity of TTS takes, they are expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere with sperm whale communication or other important lowfrequency cues—and that the associated lost opportunities and capabilities are not at a level that would impact reproduction or survival. For these same reasons (low level and frequency band), while a small permanent loss of hearing sensitivity may include some degree of energetic costs for compensating or may mean some small loss of opportunities or detection capabilities, at the expected scale, estimated Level A harassment takes by PTS for dwarf and pygmy sperm whales would be unlikely to impact behaviors, opportunities, or detection capabilities to a degree that would interfere with reproductive success or survival of any individuals, even if it were to be experienced by an animal that also experiences one or more instances of Level B harassment by behavioral disturbance. Thus the 29 and 64 total Level A harassment takes by PTS for dwarf and pygmy sperm whales, respectively, would be unlikely to affect rates of recruitment and survival for these stocks. Altogether, a portion of these stocks are likely to be impacted and any individuals are likely to be disturbed at a low-moderate level, with the taken individuals likely exposed between 1 and 5 days, with little chance that any are taken across sequential days. This low magnitude and severity of Level A and Level B harassment effects is not expected to result in impacts on individual reproduction or survival, much less impacts on annual rates of recruitment or survival. For these reasons, we have preliminarily determined, in consideration of all of the effects of the Navy’s activities combined, that the expected and authorized take proposed would have a negligible impact on the Hawaii stocks of pygmy and dwarf sperm whales. Beaked Whales In table 16 and table 17 below for beaked whales, we indicate the total annual mortality, Level A and Level B harassment, and a number indicating the instances of total take as a percentage of abundance. Table 16 and table 17 are unchanged from table 22 and table 23 in the 2020 HSTT final rule, with the exception of a correction to a rounding error as noted. For additional information and analysis supporting the negligible-impact analysis, see the Odontocetes discussion as well as the Beaked Whales discussion in the Group and Species-Specific Analyses section of the 2018 HSTT final rule, all of which remains applicable to this proposed rule unless specifically noted. TABLE 16—ANNUAL ESTIMATED TAKES BY LEVEL B HARASSMENT, LEVEL A HARASSMENT, AND MORTALITY FOR BEAKED WHALES IN THE HRC PORTION OF THE HSTT STUDY AREA AND NUMBER INDICATING THE INSTANCES OF TOTAL TAKE AS A PERCENTAGE OF STOCK ABUNDANCE Instances of indicated types of incidental take (not all takes represent separate individuals, especially for disturbance) Total takes Level B harassment Species Blainville’s beaked whale. Cuvier’s beaked whale. Longman’s beaked whale. Stock Total Takes (entire Study Area) Level A harassment Takes (within Navy EEZ) Abundance Instances of total take as percent of abundance Total Navy abundance inside and outside EEZ (HRC) Within EEZ Navy abundance (HRC) Total take as percentage of total Navy abundance (HRC) EEZ take as percentage of EEZ abundance (HRC) Behavioral disturbance TTS (may also include disturbance) Hawaii 5,369 16 0 0 0 5,385 4,140 989 768 a 544 539 Hawaii 1,792 4 0 0 0 1,796 1,377 345 268 521 514 Hawaii 19,152 81 0 0 0 19,233 14,585 3,568 2,770 539 527 Tissue damage PTS Mortality ddrumheller on DSK120RN23PROD with PROPOSALS2 Note: For the Hawaii take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule), both in and outside of the U.S. EEZ. Because the portion of the Navy’s study area inside the U.S. EEZ is generally concomitant with the area used to generate the abundance estimates in the SARs, and the abundance predicted by the same underlying density estimates is the preferred abundance to use, there is no need to separately compare the take to the SARs abundance estimate. Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities. a The 2020 final rule unintentionally presented this percentage as 545. The correct value is provided here. This error does not affect the conclusions in the 2020 HSTT final rule. VerDate Sep<11>2014 21:42 Oct 02, 2023 Jkt 262001 PO 00000 Frm 00055 Fmt 4701 Sfmt 4702 E:\FR\FM\03OCP2.SGM 03OCP2 68344 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules TABLE 17—ANNUAL ESTIMATED TAKES BY LEVEL B HARASSMENT, LEVEL A HARASSMENT, AND MORTALITY FOR BEAKED WHALES IN THE SOCAL PORTION OF THE HSTT STUDY AREA AND NUMBER INDICATING THE INSTANCES OF TOTAL TAKE AS A PERCENTAGE OF STOCK ABUNDANCE Instances of indicated types of incidental take (not all takes represent separate individuals, especially for disturbance) Level B harassment Species Baird’s beaked whale. Cuvier’s beaked whale. Mesoplodon species. Total takes Level A harassment Stock Abundance Total Takes (entire study area) Mortality Instances of total take as percent of abundance Navy abundance in action area NMFS SARS abundance Total take as percentage of total Navy abundance in action area Total take as percentage of total SAR abundance Behavioral disturbance TTS (may also include disturbance) PTS CA/OR/WA ...... 2,030 14 0 0 0 2,044 74 1,363 2,762 150 CA/OR/WA ...... 11,373 127 1 0 0 11,501 520 5,454 2,212 211 CA/OR/WA ...... 6,125 68 1 0 0 6,194 89 3,044 6,960 203 Tissue damage Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule). Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities. Below we compile and summarize the information that supports our determination that the Navy’s activities would not adversely affect any species or stocks through effects on annual rates of recruitment or survival for any of the affected species or stocks addressed in this section. ddrumheller on DSK120RN23PROD with PROPOSALS2 Blainville’s, Cuvier’s, and Longman’s Beaked Whales (Hawaii Stocks) The SAR does not identify a trend for these stocks and the species are not listed under the ESA. No mortality or Level A harassment are expected or proposed for authorization for any of these three stocks. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated instances of take compared to the abundance, both throughout the HSTT Study Area and within the U.S. EEZ, respectively, is 521–544 and 514–539 percent (table 16). This information and the stock ranges (at least of the small, resident island associated stocks around Hawaii) suggest that likely a fair portion of the stocks (but not all) will be impacted, over 1 to perhaps 11 days per year, with little likelihood of much take across sequential days. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 160 dB, though with beaked whales, which are considered somewhat more sensitive, this could mean that some individuals will leave preferred habitat for a day or 2 (i.e., moderate level takes). However, while interrupted feeding bouts are a VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 known response and concern for odontocetes, we also know that there are often viable alternative habitat options nearby. Additionally, as noted earlier, within the Hawaii Island mitigation area (which overlaps a large portion of the BIAs for Cuvier’s and Blainville’s beaked whales), explosives are not used and the use of MF1 and MF4 active sonar is limited, greatly reducing the severity of impacts within these two small resident populations. Regarding the severity of TTS takes, they are expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere with beaked whale communication or other important lowfrequency cues, and that the associated lost opportunities and capabilities are not at a level that would impact reproduction or survival. Altogether, a fair portion of these stocks are anticipated to be impacted and any individuals are likely to be disturbed at a moderate level, with the taken individuals likely exposed between 1 and 11 days, with little chance that individuals are taken across more than a few sequential days. This low, to occasionally moderate, magnitude and severity of harassment effects is not expected to result in impacts on individual reproduction or survival, much less have impacts on annual rates of recruitment or survival. For these reasons, we have preliminarily determined, in consideration of all of the effects of the Navy’s activities combined, that the authorized take proposed would have a negligible impact on the Hawaii stocks of beaked whales. PO 00000 Frm 00056 Fmt 4701 Sfmt 4702 Baird’s and Cuvier’s Beaked Whales and Mesoplodon Species (All CA/OR/WA Stocks) The species are not listed under the ESA and their populations have been identified as ‘‘increasing,’’ ‘‘decreasing,’’ and ‘‘increasing,’’ respectively. No mortality is expected or proposed for authorization for any of these three stocks and only two takes by Level A harassment (PTS) are proposed for authorization. No methods are available to distinguish between the six species of Mesoplodon beaked whale CA/OR/WA stocks (Blainville’s beaked whale (M. densirostris), Perrin’s beaked whale (M. perrini), Lesser beaked whale (M. peruvianus), Stejneger’s beaked whale (M. stejnegeri), Gingko-toothed beaked whale (M. gingkodens), and Hubbs’ beaked whale (M. carlhubbsi)) when observed during at-sea surveys (Carretta et al. 2018a). Bycatch and stranding records from the region indicate that the Hubbs’ beaked whale is most commonly encountered (Carretta et al. 2008, Moore and Barlow, 2013). As indicated in the SAR, no species-specific abundance estimates are available, the abundance estimate includes all CA/OR/WA Mesoplodon spp, and the six species are managed as one unit. Due to the lack of species-specific abundance estimates, it is not possible to predict the take of individual species and take estimates are identified as Mesoplodon spp. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated total instances of take compared to the abundance for these stocks is 2,762, 2,212, and 6,960 percent (measured against Navy-estimated abundance) and E:\FR\FM\03OCP2.SGM 03OCP2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules ddrumheller on DSK120RN23PROD with PROPOSALS2 150, 211, and 203 percent (measured against the SAR) for Baird’s beaked whales, Cuvier’s beaked whales, and Mesoplodon spp., respectively (table 15). Given the ranges of these stocks, this information suggests that some smaller portion of the individuals of these stocks will be taken, and that some subset of individuals within the stock will be taken repeatedly within the year (perhaps up to 20–25 days, and potentially more for Cuvier’s)— potentially over a fair number of sequential days, especially where individuals spend extensive time in the SOCAL Range. Note that we predict lower days of repeated exposure for these stocks than their percentages might have suggested because of the number of overall takes—i.e., using the higher percentage would suggest that an unlikely portion of the takes are taken up by a small portion of the stock incurring a very large number of repeat takes, with little room for take resulting from few or moderate numbers of repeats, which is unlikely. While interrupted feeding bouts are a known response and concern for odontocetes, we also know that there are often viable alternative habitat options in the relative vicinity. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, we have explained that the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 160 dB, though with beaked whales, which are considered somewhat more sensitive, this could mean that some individuals will leave preferred habitat for a day or 2 (i.e., of a moderate level). In addition, as noted, some of these takes could occur on a fair number of sequential days for these stocks. The severity of TTS takes is expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere significantly with conspecific communication, echolocation, or other important low-frequency cues. Therefore, the associated lost opportunities and capabilities would not be expected to impact reproduction or survival. For similar reasons (as VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 described in the 2020 HSTT final rule) the single estimated Level A harassment take by PTS for this stock is unlikely to have any effects on the reproduction or survival of any individuals. Altogether, a portion of these stocks will likely be taken (at a moderate or sometimes low level) over several days a year, and some smaller portion of the stock is expected to be taken on a relatively moderate to high number of days across the year, some of which could be sequential days. Though the majority of impacts are expected to be of a moderate severity, the repeated takes over a potentially fair number of sequential days for some individuals makes it more likely that a small number of individuals could be interrupted during foraging in a manner and amount such that impacts to the energy budgets of females (from either losing feeding opportunities or expending considerable energy to find alternative feeding options) could cause them to forego reproduction for a year. Energetic impacts to males are generally meaningless to population rates unless they cause death, and it takes extreme energy deficits beyond what would ever be likely to result from these activities to cause the death of an adult marine mammal. As noted previously, however, foregone reproduction (especially for 1 year, which is the maximum predicted because the small number anticipated in any 1 year makes the probability that any individual would be impacted in this way twice in 7 years very low) has far less of an impact on population rates than mortality and a small number of instances of foregone reproduction would not be expected to adversely affect these stocks through effects on annual rates of recruitment or survival, especially given the residual PBR of these three beaked whale stocks (8.7, 41.9, and 19.9, respectively). Further, Navy activities have been conducted in SOCAL for many years at similar levels and the SAR considers Mesoplodon spp. and Baird’s beaked whales as increasing. While NMFS’ SAR indicates that Cuvier’s beaked whales on the U.S. West Coast are declining based on a Bayesian trend analysis of NMFS’ survey data collected from 1991 through 2014, results from passive PO 00000 Frm 00057 Fmt 4701 Sfmt 4702 68345 acoustic monitoring and other research have estimated regional Cuvier’s beaked whale densities that were higher than indicated by NMFS’ broad-scale visual surveys for the U.S. West Coast (Debich et al. 2015a; Debich et al. 2015b; Falcone and Schorr, 2012, 2014; Hildebrand et al. 2009; Moretti, 2016; Sˇirovic´ et al. 2016; Smultea and Jefferson, 2014). Research also indicates higher than expected residency in the Navy’s instrumented Southern California Anti-Submarine Warfare Range in particular (Falcone and Schorr, 2012) and photo identification studies in the SOCAL have identified approximately 100 individual Cuvier’s beaked whale individuals with 40 percent having been seen in one or more prior years, with re-sightings up to 7 years apart (Falcone and Schorr, 2014). The documented residency by many Cuvier’s beaked whales over multiple years suggests that a stable population may exist in that small portion of the stock’s overall range (Falcone et al. 2009; Falcone and Schorr, 2014; Schorr et al. 2017). For these reasons, in consideration of all of the effects of the Navy’s activities combined, we have preliminarily determined that the authorized take proposed would have a negligible impact on the CA/OR/WA stocks of Baird’s and Cuvier’s beaked whales, as well as all six species included within the Mesoplodon spp. Small Whales and Dolphins In table 18 and table 19 below for dolphins and small whales, we indicate the total annual mortality, Level A and Level B harassment, and a number indicating the instances of total take as a percentage of abundance. Table 18 and table 19 are updated from tables 24 and 25 in the 2020 HSTT final rule as appropriate with the 2022 final SARs. For additional information and analysis supporting the negligible-impact analysis, see the Odontocetes discussion as well as the Small Whales and Dolphins discussion in the Group and Species-Specific Analyses section of the 2018 HSTT final rule, all of which remains applicable to this proposed rule unless specifically noted. E:\FR\FM\03OCP2.SGM 03OCP2 68346 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules TABLE 18—ANNUAL ESTIMATED TAKES BY LEVEL B HARASSMENT, LEVEL A HARASSMENT, AND MORTALITY FOR DOLPHINS AND SMALL WHALES IN THE HRC PORTION OF THE HSTT STUDY AREA AND NUMBER INDICATING THE INSTANCES OF TOTAL TAKE AS A PERCENTAGE OF STOCK ABUNDANCE Instances of indicated types of incidental take (not all takes represent separate individuals, especially for disturbance) Level B harassment Species Bottlenose dolphin. Bottlenose dolphin. Bottlenose dolphin. Bottlenose dolphin. Bottlenose dolphin. False killer whale. False killer whale. ddrumheller on DSK120RN23PROD with PROPOSALS2 False killer whale. Fraser’s dolphin. Killer whale. Melonheaded whale. Melonheaded whale. Pantropical spotted dolphin. Pantropical spotted dolphin. Pantropical spotted dolphin. Pantropical spotted dolphin. Pygmy killer whale. Pygmy killer whale. Risso’s dolphin. Roughtoothed dolphin. Shortfinned pilot whale. Spinner dolphin. Spinner dolphin. Spinner dolphin. Total takes Level A harassment Stock Total takes (entire study area) Abundance Takes (within Navy EEZ) Instance of total take as percent of abundance Total Navy abundance inside and outside of EEZ (HRC) Within EEZ Navy abundance (HRC) Total take as percentage of total Navy abundance (HRC) EEZ take as percentage of Navy EEZ abundance (HRC) 218 172 Behavioral disturbance TTS (may also include disturbance) PTS 3,196 132 0 0 0 3,328 2,481 1,528 1,442 534 31 0 0 0 565 264 184 184 307 143 a 1,127 Mortality Tissue damage Hawaii Pelagic. Kauai & Niihau. Oahu ...... 8,600 61 1 0 0 8,662 8,376 743 743 a 1,166 4-Island .. 349 10 0 0 0 359 316 189 189 190 167 Hawaii .... 74 6 0 0 0 80 42 131 131 61 32 Hawaii Pelagic. 999 42 0 0 0 1,041 766 645 507 161 151 Main Hawaiian Islands Insular. Northwestern Hawaiian Islands. Hawaii .... 572 17 0 0 0 589 476 147 147 b 401 324 365 16 0 0 0 381 280 215 169 177 166 39,784 1,289 2 0 0 41,075 31,120 5,408 18,763 760 166 Hawaii .... 118 6 0 0 0 124 93 69 54 180 172 Hawaii Islands. 3,261 231 0 0 0 3,492 2,557 1,782 1,782 196 143 Kohala Resident. Hawaii Island. 341 9 0 0 0 350 182 447 447 78 41 3,767 227 0 0 0 3,994 2,576 2,405 2,405 166 107 Hawaii Pelagic. 9,973 476 0 0 0 10,449 7,600 5,462 4,637 191 164 Oahu ...... 4,284 45 0 0 0 4,329 4,194 372 372 1,164 1,127 4-Island .. 701 17 0 0 0 718 634 657 657 109 96 Hawaii .... 8,122 402 0 0 0 8,524 6,538 4,928 3,931 173 166 Tropical .. 710 50 0 0 0 760 490 159 23 478 2,130 Hawaii .... 8,950 448 0 0 0 9,398 7,318 1,210 4,199 777 174 Hawaii .... 6,112 373 0 0 0 6,485 4,859 3,054 2,808 212 173 Hawaii .... 12,499 433 0 0 0 12,932 9,946 6,433 5,784 201 172 Hawaii Island. Hawaii Pelagic. Kauai & Niihau. 279 12 0 0 0 291 89 629 629 46 14 4,332 202 0 0 0 4,534 3,491 2,885 2,229 157 157 1,683 63 0 0 0 1,746 812 604 604 289 134 VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 PO 00000 Frm 00058 Fmt 4701 Sfmt 4702 E:\FR\FM\03OCP2.SGM 03OCP2 68347 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules TABLE 18—ANNUAL ESTIMATED TAKES BY LEVEL B HARASSMENT, LEVEL A HARASSMENT, AND MORTALITY FOR DOLPHINS AND SMALL WHALES IN THE HRC PORTION OF THE HSTT STUDY AREA AND NUMBER INDICATING THE INSTANCES OF TOTAL TAKE AS A PERCENTAGE OF STOCK ABUNDANCE—Continued Instances of indicated types of incidental take (not all takes represent separate individuals, especially for disturbance) Level B harassment Species Spinner dolphin. Striped dolphin. Total takes Level A harassment Stock Total takes (entire study area) Abundance Takes (within Navy EEZ) Instance of total take as percent of abundance Total Navy abundance inside and outside of EEZ (HRC) Within EEZ Navy abundance (HRC) Total take as percentage of total Navy abundance (HRC) EEZ take as percentage of Navy EEZ abundance (HRC) Behavioral disturbance TTS (may also include disturbance) PTS 1,790 34 1 0 0 1,825 1,708 354 354 516 482 7,379 405 0 0 0 7,784 6,034 4,779 3,646 163 165 Oahu & 4Island. Hawaii .... Mortality Tissue damage Note: For the Hawaii take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule), both in and outside of the U.S. EEZ. Because the portion of the Navy’s study area inside the U.S. EEZ is generally concomitant with the area used to generate the abundance estimates in the SARs, and the abundance predicted by the same underlying density estimates is the preferred abundance to use, there is no need to separately compare the take to the SARs abundance estimate. Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities. a The 2020 final rule unintentionally presented these percentages as 1,169 and 1,130. The correct values are provided here. These errors do not affect the conclusions in the 2020 HSTT final rule. b The 2020 final rule unintentionally presented this percentage as 400. The correct value is provided here. This rounding error does not affect the conclusions in the 2020 HSTT final rule. TABLE 19—ANNUAL ESTIMATED TAKES BY LEVEL B HARASSMENT, LEVEL A HARASSMENT, AND MORTALITY FOR DOLPHINS AND SMALL WHALES IN THE SOCAL PORTION OF THE HSTT STUDY AREA AND NUMBER INDICATING THE INSTANCES OF TOTAL TAKE AS A PERCENTAGE OF STOCK ABUNDANCE Instances of indicated types of incidental take (not all takes represent separate individuals, especially for disturbance) Level B harassment Species Bottlenose dolphin. Bottlenose dolphin. Killer whale .... Killer whale .... ddrumheller on DSK120RN23PROD with PROPOSALS2 Long-beaked common dolphin. Northern right whale dolphin. Pacific whitesided dolphin. Risso’s dolphin Short-beaked common dolphin. Short-finned pilot whale. Striped dolphin Total takes Level A harassment Total takes (entire study area) Stock Abundance Instance of total take as percent of abundance Navy abundance in action area (SOCAL) NMFS SARS abundance Total take as percentage of total Navy abundance in action area Total take as percentage of total SAR abundance Behavioral disturbance TTS (may also include disturbance) PTS 1,771 38 0 0 0 1,809 238 453 760 399 51,727 3,695 3 0 0 55,425 5,946 3,477 932 1,594 Mortality Tissue damage California Coastal. CA/OR/WA Offshore. ENP Offshore ENP Transient/West Coast Transient. California ....... 96 179 11 20 0 0 0 0 0 0 107 199 4 30 300 349 2,675 663 36 57 233,485 13,787 18 2 0 247,292 10,258 83,379 2,411 297 CA/OR/WA .... 90,052 8,047 10 1 0 98,110 7,705 29,285 1,273 335 CA/OR/WA .... 69,245 6,093 5 0 0 75,343 6,626 34,999 1,137 215 CA/OR/WA .... CA/OR/WA .... 116,143 1,374,048 10,118 118,525 9 79 0 10 0 1.14 126,270 1,492,664 7,784 261,438 6,336 1,056,308 1,622 571 1,993 141 CA/OR/WA .... 1,789 124 1 0 0 1,914 208 836 920 229 CA/OR/WA .... 163,640 11,614 3 0 0 175,257 39,862 29,988 440 584 Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule). Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities. For mortality takes there is an annual average of 1.14 short-beaked common dolphins (i.e., where eight takes could potentially occur divided by 7 years to get the annual number of mortalities/serious injuries). Below we compile and summarize the information that supports our determination that the Navy’s activities VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 would not adversely affect any species or stocks through effects on annual rates of recruitment or survival for any of the PO 00000 Frm 00059 Fmt 4701 Sfmt 4702 affected species or stocks addressed in this section. E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68348 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules Long-Beaked Common Dolphin (California Stock), Northern Right Whale Dolphin (CA/OR/WA Stock), and Short-Beaked Common Dolphin (CA/ OR/WA Stock) None of these stocks are listed under the ESA and their stock statuses are considered ‘‘increasing,’’ ‘‘unknown,’’ and ‘‘increasing,’’ respectively. Eight mortalities or serious injuries of shortbeaked common dolphins are proposed for authorization over the 7-year rule, or 1.14 M/SI annually. The addition of this 1.14 annual mortality still leaves the total human-caused mortality well under the insignificance threshold for residual PBR. The three stocks are expected to accrue 2, 1, and 10 Level A harassment takes from tissue damage resulting from exposure to explosives, respectively. As described in detail in the 2018 HSTT final rule, the impacts of a Level A harassment take by tissue damage could range in impact from minor to something just less than M/SI that could seriously impact fitness. However, given the Navy’s procedural mitigation, exposure closer to the source and more severe end of the spectrum is less likely and we cautiously assume some moderate impact for these takes that could lower the affected individual’s fitness within the year such that a female (assuming a 50 percent chance of it being a female) might forego reproduction for 1 year. As noted previously, foregone reproduction has less of an impact on population rates than death (especially for only 1 year in 7, which is the maximum predicted because the small number anticipated in any 1 year makes the probability that any individual would be impacted in this way twice in 7 years very low), and 1 to 10 instances would not be expected to impact annual rates of recruitment or survival for these stocks. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated total instances of take compared to the abundance (measured against both the Navy-estimated abundance and the SAR) is 2,411, 1,273, and 571 percent (respective to the stocks listed in the heading) and 297, 335, and 141 percent (respective to the stocks listed in the heading) (table 19). Given the range of these stocks, this information suggests that likely some portion (but not all or even the majority) of the individuals in the northern right whale dolphin and short-beaked common dolphin stocks are likely impacted while it is entirely possible that most or all of the rangelimited long-beaked common dolphin is taken. All three stocks likely will experience some repeat Level B VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 harassment exposure (perhaps up to 48, 25, or 11 days within a year, respective to the stocks listed in the heading) of some subset of individuals that spend extended time within the SOCAL range complex. While interrupted feeding bouts are a known response and concern for odontocetes, we also know that there are often viable alternative habitat options in the relative vicinity. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB with a portion up to 178 dB (i.e., of a moderate or lower level, less likely to evoke a severe response). However, some of these takes could occur on a fair number of sequential days for long-beaked common dolphins or northern right whale dolphins, or even some number of short-beaked common dolphins, given the high number of total takes (i.e., the probability that some number of individuals get taken on a higher number of sequential days is higher, because the total take number is relatively high, even though the percentage is not that high). The severity of TTS takes is expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere significantly with conspecific communication, echolocation, or other important low-frequency cues, and the associated lost opportunities and capabilities would not be expected to impact reproduction or survival. For these same reasons (low level and frequency band), while a small permanent loss of hearing sensitivity may include some degree of energetic costs for compensating or may mean some small loss of opportunities or detection capabilities, as discussed in the 2020 HSTT final rule, it would be unlikely to impact behaviors, opportunities, or detection capabilities to a degree that would interfere with reproductive success or survival of any individuals. Altogether and as described in more detail above, 1.14 annual lethal takes of short-beaked common dolphins are proposed for authorization, all three stocks may experience a very small number of takes by tissue damage or PTS (relative to the stock abundance and PBR), and a moderate to large portion of all three stocks will likely be taken (at a low to occasionally moderate level) over several days a year, and some smaller portion of these stocks is expected to be taken on a relatively moderate to high number of days across PO 00000 Frm 00060 Fmt 4701 Sfmt 4702 the year, some of which could be sequential days. Though the majority of impacts are expected to be of a lower to sometimes moderate severity, the larger number of takes (in total and for certain individuals) makes it more likely (probabilistically) that a small number of individuals could be interrupted during foraging in a manner and amount such that impacts to the energy budgets of females (from either losing feeding opportunities or expending considerable energy to find alternative feeding options) could cause them to forego reproduction for a year. Energetic impacts to males are generally meaningless to population rates unless they cause death, and it takes extreme energy deficits beyond what would ever be likely to result from these activities to cause the death of an adult marine mammal. As noted previously, however, foregone reproduction (especially for only 1 year out of 7, which is the maximum predicted because the small number anticipated in any 1 year makes the probability that any individual would be impacted in this way twice in 7 years very low) has far less of an impact on population rates than mortality and a small number of instances of foregone reproduction (including in combination with that which might result from the small number of tissue damage takes) would not be expected to adversely affect the stocks through effects on annual rates of recruitment or survival, especially given the very high residual PBRs of these stocks (638.3, 156.4, and 8,858.5, respectively). For these reasons, in consideration of all of the effects of the Navy’s activities combined (mortality, Level A harassment, and Level B harassment), we have preliminarily determined that the authorized take proposed would have a negligible impact on these three stocks of dolphins. All Other SOCAL Dolphin Stocks (Except Long-Beaked Common Dolphin, Northern Right Whale Dolphin, and Short-Beaked Common Dolphin) None of these stocks are listed under the ESA and their stock statuses are considered ‘‘unknown,’’ except for the bottlenose dolphin (California coastal stock) and killer whale (Eastern North Pacific stock), which are considered ‘‘stable.’’ No M/SI or Level A harassment via tissue damage from exposure to explosives is expected or proposed for authorization for these stocks. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated total instances of take compared to the E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules abundance (measured against both the Navy-estimated abundance and the SAR) is from 440 to 2,675 percent and 36 to 1,993 percent, respectively (table 19). Given the range of these stocks (along the entire U.S. West Coast, or even beyond, with some also extending seaward of the HSTT Study Area boundaries), this information suggests that some portion (but not all or even the majority) of the individuals of any of these stocks will be taken, with the exception that most or all of the individuals of the more range-limited California coastal stock of bottlenose dolphin may be taken. It is also likely that some subset of individuals within most of these stocks will be taken repeatedly within the year (perhaps up to 10–15 days within a year) but with no more than several potentially sequential days, although the CA/OR/ WA stocks of bottlenose dolphins, Pacific white-sided dolphins, and Risso’s dolphins may include individuals that are taken repeatedly within the year over a higher number of days (up to 57, 22, and 40 days, respectively) and potentially over a fair number of sequential days, especially where individuals spend extensive time in the SOCAL range complex. Note that though percentages are high for the Eastern North Pacific stock of killer whales and short-finned pilot whales, given the low overall number of takes, it is highly unlikely that any individuals would be taken across the number of days their percentages would suggest. While interrupted feeding bouts are a known response and concern for odontocetes, we also know that there are often viable alternative habitat options in the relative vicinity. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, we have explained that the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB (i.e., of a lower, or sometimes moderate level, less likely to evoke a severe response). However, as noted, some of these takes could occur on a fair number of sequential days for the three stocks listed earlier. The severity of TTS takes is expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere significantly with conspecific communication, echolocation, or other important low-frequency cues. For these same reasons (low level and frequency band), while a small permanent loss of hearing sensitivity may include some degree of energetic costs for VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 compensating or may mean some small loss of opportunities or detection capabilities, it would be unlikely to impact behaviors, opportunities, or detection capabilities to a degree that would interfere with reproductive success or survival of any individuals. Altogether, a portion of all of these stocks will likely be taken (at a low to occasionally moderate level) over several days a year, and some smaller portion of CA/OR/WA stocks of bottlenose dolphins, Pacific white-sided dolphins, and Risso’s dolphins, specifically, are expected to be taken on a relatively moderate to high number of days across the year, some of which could be sequential days. Though the majority of impacts are expected to be of a lower to sometimes moderate severity, the larger number of takes (in total and for certain individuals) for the CA/OR/WA stocks of bottlenose dolphins, Pacific white-sided dolphins, and Risso’s dolphins makes it more likely (probabilistically) that a small number of individuals could be interrupted during foraging in a manner and amount such that impacts to the energy budgets of females (from either losing feeding opportunities or expending considerable energy to find alternative feeding options) could cause them to forego reproduction for a year. Energetic impacts to males are generally meaningless to population rates unless they cause death, and it takes extreme energy deficits beyond what would ever be likely to result from these activities to cause the death of an adult marine mammal. As noted previously, however, foregone reproduction (especially for only 1 year in 7, which is the maximum predicted because the small number anticipated in any 1 year makes the probability that any individual would be impacted in this way twice in 7 years very low) has far less of an impact on population rates than mortality and a small number of instances of foregone reproduction would not be expected to adversely affect the stocks through effects on annual rates of recruitment or survival, especially given the residual PBRs of the CA/OR/WA stocks of bottlenose dolphins, Pacific white-sided dolphins, and Risso’s dolphins (18.9, 272, and 42.3, respectively). For these reasons, in consideration of all of the effects of the Navy’s activities combined, we have preliminarily determined that the authorized take proposed would have a negligible impact on these stocks of dolphins. All HRC Dolphin Stocks With the exception of the Main Hawaiian Island stock of false killer whales (listed as endangered under the PO 00000 Frm 00061 Fmt 4701 Sfmt 4702 68349 ESA, with the MMPA stock identified as ‘‘decreasing’’), none of these stocks are listed under the ESA and their stock statuses are considered ‘‘unknown.’’ No M/SI or Level A harassment via tissue damage from exposure to explosives is expected or proposed for authorization for these stocks. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated total instances of take compared to the abundance (measured against both the Navy-estimated abundance and the SAR) is from 46 to 1,166 percent and 14 to 2,130 percent, respectively (table 16). Given the ranges of these stocks (many of them are small, resident, islandassociated stocks), this information suggests that a fairly large portion of the individuals of many of these stocks will be taken but that most individuals will only be impacted across a smaller to moderate number of days within the year (1–15), and with no more than several potentially sequential days, although two stocks (the Oahu stocks of bottlenose dolphin and pantropical spotted dolphin) have a slightly higher percentage, suggesting they could be taken up to 23 days within a year, with perhaps a few more of those days being sequential. We note that although the percentage is higher for the tropical stock of pygmy killer whale within the U.S. EEZ (2,130), given (1) the low overall number of takes (760) and (2) the fact that the small within-U.S. EEZ abundance is not a static set of individuals, but rather individuals moving in and out of the U.S. EEZ making it more appropriate to use the percentage comparison for the total takes versus total abundance—it is highly unlikely that any individuals would be taken across the number of days the within-U.S. EEZ percentage suggests (42). While interrupted feeding bouts are a known response and concern for odontocetes, we also know that there are often viable alternative habitat options in the relative vicinity. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB (i.e., of a lower, or sometimes moderate level, less likely to evoke a severe response). However, as noted, some of these takes could occur on a fair number of sequential days for the Oahu stocks of bottlenose dolphin and pantropical spotted dolphins. Regarding the severity of TTS takes, they are expected to be low-level, of short duration, and mostly not in a frequency band that would be expected E:\FR\FM\03OCP2.SGM 03OCP2 68350 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules to interfere significantly with conspecific communication, echolocation, or other important lowfrequency cues. For these same reasons (low level and frequency band), while a small permanent loss of hearing sensitivity may include some degree of energetic costs for compensating or may mean some small loss of opportunities or detection capabilities, they would be unlikely to impact behaviors, opportunities, or detection capabilities to a degree that would interfere with reproductive success or survival of any individuals, even if accrued to individuals that are also taken by behavioral harassment at the same time. Altogether, most of these stocks (all but the Oahu stocks of bottlenose dolphin and pantropical spotted dolphins) will likely be taken (at a low to occasionally moderate level) over several days a year, with some smaller portion of the stock potentially taken on a more moderate number of days across the year (perhaps up to 15 days for Fraser’s dolphin, though others notably less), some of which could be across a few sequential days, which is not expected to affect the reproductive success or survival of individuals. For the Oahu stocks of bottlenose dolphin and pantropical spotted dolphins, some subset of individuals could be taken up to 23 days in a year, with some small number being taken across several sequential days, such that a small number of individuals could be interrupted during foraging in a manner and amount such that impacts to the energy budgets of females (from either losing feeding opportunities or expending considerable energy to find alternative feeding options) could cause them to forego reproduction for a year. Energetic impacts to males are generally meaningless to population rates unless they cause death, and it takes extreme energy deficits beyond what would ever be likely to result from these activities to cause the death of an adult marine mammal. As noted previously, however, foregone reproduction (especially for 1 year, which is the maximum predicted because the small number anticipated in any 1 year makes the probability that any individual would be impacted in this way twice in 7 years very low) has far less of an impact on population rates than mortality and a small number of instances of foregone reproduction would not be expected to adversely affect these two stocks through effects on annual rates of recruitment or survival. For these reasons, in consideration of all of the effects of the Navy’s activities combined, we have preliminarily determined that the authorized take proposed would have a negligible impact on all of the stocks of dolphins found in the vicinity of the HRC. Dall’s Porpoise In table 20 below for porpoises, we indicate the total annual mortality, Level A harassment and Level B harassment, and a number indicating the instances of total take as a percentage of abundance. Table 20 is updated from table 26 in the 2020 HSTT final rule with the 2022 final SARs. For additional information and analysis supporting the negligible-impact analysis, see the Odontocetes discussion as well as the Dall’s Porpoise discussion in the Group and Species-Specific Analyses section of the 2018 HTT final rule, all of which remains applicable to this proposed rule unless specifically noted. TABLE 20—ANNUAL ESTIMATED TAKES BY LEVEL B HARASSMENT, LEVEL A HARASSMENT, AND MORTALITY FOR PORPOISES IN THE HSTT STUDY AREA AND NUMBER INDICATING THE INSTANCES OF TOTAL TAKE AS A PERCENTAGE OF STOCK ABUNDANCE Instances of indicated types of incidental take (not all takes represent separate individuals, especially for disturbance) Level B harassment Species Dall’s porpoise Level A harassment CA/OR/WA ...... Behavioral disturbance PTS Tissue damage 14,482 29,891 209 0 Abundance Mortality Total takes (entire study area) Navy abundance in action area NMFS SARS abundance 0 44,582 2,054 16,498 Stock TTS (may also include disturbance) Total takes Instances of total take as percent of abundance Total take as percentage of total Navy abundance in action area Total take as percentage of total SAR abundance 2,170 270 ddrumheller on DSK120RN23PROD with PROPOSALS2 Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule). Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities. Below we compile and summarize the information that supports our determination that the Navy’s activities would not adversely affect Dall’s porpoises through effects on annual rates of recruitment or survival. Dall’s porpoise is not listed under the ESA and the stock status is considered ‘‘unknown.’’ No M/SI or Level A harassment via tissue damage from exposure to explosives is expected or proposed for authorization for this stock. Most Level B harassments to Dall’s porpoise from hull-mounted sonar (MF1) in the HSTT Study Area would result from received levels between 154 VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 and 166 dB SPL (85 percent). While harbor porpoises have been observed to be especially sensitive to human activity, the same types of responses have not been observed in Dall’s porpoises. Dall’s porpoises are typically notably longer than and weigh more than twice as much as harbor porpoises making them generally less likely to be preyed upon and likely differentiating their behavioral repertoire somewhat from harbor porpoises. Further, they are typically seen in large groups and feeding aggregations or exhibiting bowriding behaviors, which is very different from the group dynamics observed in the more typically solitary, cryptic PO 00000 Frm 00062 Fmt 4701 Sfmt 4702 harbor porpoises, which are not often seen bow-riding. For these reasons, Dall’s porpoises are not treated as especially sensitive species (as compared to harbor porpoises, which have a lower threshold for Level B harassment by behavioral disturbance and more distant cutoff) but, rather, are analyzed similarly to other odontocetes. Therefore, the majority of Level B harassment takes are expected to be in the form of milder responses compared to higher level exposures. As discussed more fully in the 2018 HSTT final rule, we anticipate more severe effects from takes when animals are exposed to higher received levels. E:\FR\FM\03OCP2.SGM 03OCP2 68351 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), the number of estimated total instances of take compared to the abundance (measured against both the Navy-estimated abundance and the SAR) is 2,170 and 270 percent, respectively (table 20). Given the range of this stock (up the U.S. West Coast through Washington and sometimes beyond the U.S. EEZ), this information suggests that some smaller portion of the individuals of this stock will be taken, and that some subset of individuals within the stock will be taken repeatedly within the year (perhaps up to 42 days)—potentially over a fair number of sequential days, especially where individuals spend extensive time in the SOCAL range complex. While interrupted feeding bouts are a known response and concern for odontocetes, we also know that there are often viable alternative habitat options in the relative vicinity. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB (i.e., of a lower, or sometimes moderate level, less likely to evoke a severe response). However, as noted, some of these takes could occur on a fair number of sequential days for this stock. The severity of TTS takes is expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere significantly with conspecific communication, echolocation, or other important low-frequency cues. Therefore, the associated lost opportunities and capabilities would not be expected to impact reproduction or survival. For these same reasons (low level and the likely frequency band), while a small permanent loss of hearing sensitivity may include some degree of energetic costs for compensating or may mean some small loss of opportunities or detection capabilities, the estimated 209 takes by Level A harassment by PTS for Dall’s porpoise would be unlikely to impact behaviors, opportunities, or detection capabilities to a degree that would interfere with reproductive success or survival for most individuals. Because of the high number of PTS takes, however, we acknowledge that a few animals could potentially incur permanent hearing loss of a higher degree that could potentially interfere with their successful reproduction and growth. Given the status of the stock, even if this occurred, it would not adversely impact rates of recruitment or survival. Altogether, a portion of this stock will likely be taken (at a low to occasionally moderate level) over several days a year, and some smaller portion of the stock is expected to be taken on a relatively moderate to high number of days across the year, some of which could be sequential days. Though the majority of impacts are expected to be of a lower to sometimes moderate severity, the larger number of takes (in total and for certain individuals) for the Dall’s porpoise makes it more likely (probabilistically) that a small number of individuals could be interrupted during foraging in a manner and amount such that impacts to the energy budgets of females (from either losing feeding opportunities or expending considerable energy to find alternative feeding options) could cause them to forego reproduction for a year. Energetic impacts to males are generally meaningless to population rates unless they cause death, and it takes extreme energy deficits beyond what would ever be likely to result from these activities to cause the death of an adult marine mammal. Similarly, we acknowledge the potential for this to occur to a few individuals out of the 209 total that might incur a higher degree of PTS. As noted previously, however, foregone reproduction (especially for only 1 year in 7, which is the maximum predicted because the small number anticipated in any 1 year makes the probability that any individual would be impacted in this way twice in 7 years very low) has far less of an impact on population rates than mortality. Further, the small number of instances of foregone reproduction that could potentially result from PTS and/or the few repeated, more severe Level B harassment takes by behavioral disturbance would not be expected to adversely affect the stock through effects on annual rates of recruitment or survival, especially given the status of the species (not endangered or threatened; minimum population of 10,286 just within the U.S. EEZ) and residual PBR of Dall’s porpoise (98.3). For these reasons, in consideration of all of the effects of the Navy’s activities combined, we have preliminarily determined that the authorized take proposed would have a negligible impact on Dall’s porpoise. Pinnipeds In table 21 and table 22 below for pinnipeds, we indicate the total annual mortality, Level A harassment and Level B harassment, and a number indicating the instances of total take as a percentage of abundance. Table 21 and table 22 have been updated from tables 27 and 28 in the 2020 HSTT final rule with the 2022 final SARs, as appropriate. For additional information and analysis supporting the negligibleimpact analysis, see the Pinnipeds discussion in the Group and SpeciesSpecific Analyses section of the 2018 HSTT final rule, all of which remains applicable to this proposed rule unless specifically noted. TABLE 21—ANNUAL ESTIMATED TAKES BY LEVEL B HARASSMENT, LEVEL A HARASSMENT, AND MORTALITY FOR PINNIPEDS IN THE HRC PORTION OF THE HSTT STUDY AREA AND NUMBER INDICATING THE INSTANCES OF TOTAL TAKE AS A PERCENTAGE OF STOCK ABUNDANCE Instances of indicated types of incidental take (not all takes represent separate individuals, especially for disturbance) Level B harassment Level A harassment ddrumheller on DSK120RN23PROD with PROPOSALS2 Hawaiian monk seal .... TTS (may also include disturbance) PTS Tissue damage 143 62 1 0 Abundance Instance of total take as percent of abundance Mortality Total takes (entire study area) Takes (within Navy EEZ) Total Navy abundance inside and outside of EEZ (HRC) Within EEZ Navy abundance (HRC) Total take as percentage of total Navy abundance (HRC) EEZ take as percentage of Navy EEZ abundance (HRC) 0 206 195 169 169 122 115 Species Behavioral disturbance Total takes Note: For the Hawaii take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule), both in and outside of the U.S. EEZ. Because the portion of the Navy’s study area inside the U.S. EEZ is generally concomitant with the area used to generate the abundance estimates in the SARs, and the abundance predicted by the same underlying density estimates is the preferred abundance to use, there is no need to separately compare the take to the SARs abundance estimate. Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities. VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 PO 00000 Frm 00063 Fmt 4701 Sfmt 4702 E:\FR\FM\03OCP2.SGM 03OCP2 68352 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules TABLE 22—ANNUAL ESTIMATED TAKES BY LEVEL B HARASSMENT, LEVEL A HARASSMENT, AND MORTALITY FOR PINNIPEDS IN THE SOCAL PORTION OF THE HSTT STUDY AREA AND NUMBER INDICATING THE INSTANCES OF TOTAL TAKE AS A PERCENTAGE OF STOCK ABUNDANCE Instances of indicated types of incidental take (not all takes represent separate individuals, especially for disturbance) Level B harassment Species California sea lion. Guadalupe fur seal. Northern fur seal. Harbor seal ...... Northern elephant seal. Total takes Level A harassment Total takes (entire study area) Stock Abundance Instance of total take as percent of abundance Navy abundance in action area (SOCAL) NMFS SARS abundance Total take as percentage of total Navy abundance in action area Total take as percentage of total SAR abundance Behavioral disturbance TTS (may also include disturbance) PTS U.S .................. 113,419 4,789 87 9 0.71 118,305 4,085 257,606 2,896 46 Mexico ............. 1,442 15 0 0 0 1,457 1,171 34,187 124 4 California ......... 15,167 124 1 0 0 15,292 886 14,050 1,726 109 California ......... California ......... 2,450 42,916 2,994 17,955 8 97 0 2 0 0 5,452 60,970 321 4,108 30,968 187,386 1,698 1,484 18 33 Mortality Tissue damage ddrumheller on DSK120RN23PROD with PROPOSALS2 Note: For the SOCAL take estimates, because of the manner in which the Navy action area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond and abundance may only be predicted within the U.S. EEZ, while the Navy action area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare predicted takes to both the abundance estimates for the action area, as well as the SARs. For mortality takes there is an annual average of 0.71 California sea lions (i.e., where five takes could potentially occur divided by 7 years to get the annual number of mortalities/serious injuries). Below we compile and summarize the information that supports our determination that the Navy’s activities would not adversely affect any pinnipeds through effects on annual rates of recruitment or survival for any of the affected species or stocks addressed in this section. Five M/SI takes of California sea lions are proposed for authorization and when this mortality is combined with the other human-caused mortality from other sources, it still falls well below the insignificance threshold for residual PBR (13,684). A small number of Level A harassment takes by tissue damage are also proposed for authorization (nine and two for California sea lions and northern elephant seals, respectively), which, as discussed in the 2020 HSTT final rule, could range in impact from minor to something just less than M/SI that could seriously impact fitness. However, given the Navy’s mitigation, exposure at the closer to the source and more severe end of the spectrum is less likely. Nevertheless, we cautiously assume some moderate impact on the individuals that experience these small numbers of take that could lower the individual’s fitness within the year such that a female (assuming a 50 percent chance of it being a female) might forego reproduction for 1 year. As noted previously, foregone reproduction has less of an impact on population rates than death (especially for only one within 7 years, which is the maximum predicted because the small number anticipated in any 1 year makes the probability that any individual would be impacted in this way twice in 7 years VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 very low) and these low numbers of instances (especially assuming the likelihood that only 50 percent of the takes would affect females) would not be expected to impact annual rates of recruitment or survival, especially given the population sizes of these species. Regarding the magnitude of Level B harassment takes (TTS and behavioral disturbance), for Hawaiian monk seals and Guadalupe fur seals, the two species listed under the ESA, the estimated instances of takes as compared to the stock abundance does not exceed 124 percent, which suggests that some portion of these two stocks would be taken on 1 to a few days per year. For the remaining stocks, the number of estimated total instances of take compared to the abundance (measured against both the Navyestimated abundance and the SAR) for these stocks is 1,484 to 2,896 percent and 18 to 46 percent, respectively (table 21). Given the ranges of these stocks (i.e., very large ranges, but with individuals often staying in the vicinity of haulouts), this information suggests that some very small portion of the individuals of these stocks will be taken, but that some subset of individuals within the stock will be taken repeatedly within the year (perhaps up to 58 days)—potentially over a fair number of sequential days. Regarding the severity of those individual Level B harassment takes by behavioral disturbance, the duration of any exposure is expected to be between minutes and hours (i.e., relatively short) and the received sound levels largely below 172 dB, which is considered a PO 00000 Frm 00064 Fmt 4701 Sfmt 4702 relatively low to occasionally moderate level for pinnipeds. However, as noted, some of these takes could occur on a fair number of sequential days for this stock. As described in the 2018 HSTT final rule and 2020 HSTT final rule, the Hawaii and 4-Islands mitigation areas protect (by not using explosives and limiting MFAS within) a significant portion of the designated critical habitat for Hawaiian monk seals in the Main Hawaiian Islands, including all of it around the islands of Hawaii and Lanai, most around Maui, and good portions around Molokai and Kaho’olawe. As discussed, this protection reduces the overall number of takes and further reduces the severity of effects by minimizing impacts near pupping beaches and in important foraging habitat. The severity of TTS takes are expected to be low-level, of short duration, and mostly not in a frequency band that would be expected to interfere significantly with conspecific communication, echolocation, or other important low-frequency cues that would affect the individual’s reproduction or survival. For these same reasons (low level and frequency band), while a small permanent loss of hearing sensitivity may include some degree of energetic costs for compensating or may mean some small loss of opportunities or detection capabilities, the one to eight estimated Level A harassment takes by PTS for monk seals, northern fur seals, and harbor seals would be unlikely to impact behaviors, opportunities, or detection capabilities to a degree that would interfere with E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules reproductive success or survival of any individuals. Because of the high number of PTS takes for California sea lions and northern elephant seals (87 and 97, respectively), we acknowledge that a few animals could potentially incur permanent hearing loss of a higher degree that could potentially interfere with their successful reproduction and growth. Given the status of the stocks, even if this occurred, it would not adversely impact rates of recruitment or survival (residual PBR of 13,684 and 5,108, respectively). Altogether, an individual Hawaiian monk seal and Guadalupe fur seal would be taken no more than a few days in any year with none of the expected take anticipated to affect individual reproduction or survival, let alone annual rates of recruitment and survival. With all other stocks, only a very small portion of the stock will be taken in any manner. Of those taken, some individuals will be taken by Level B harassment (at a moderate or sometimes low level) over several days a year, and some smaller portion of those taken will be on a relatively moderate to high number of days across the year (up to 58), a fair number of which would likely be sequential days. Though the majority of impacts are expected to be of a lower to sometimes moderate severity, the repeated takes over a potentially fair number of sequential days for some individuals makes it more likely that some number of individuals could be interrupted during foraging in a manner and amount such that impacts to the energy budgets of females (from either losing feeding opportunities or expending considerable energy to find alternative feeding options) could cause them to forego reproduction for a year (energetic impacts to males are generally meaningless to population rates unless they cause death, and it takes extreme energy deficits beyond what would ever be likely to result from these activities to cause the death of an adult marine mammal). As noted previously, however, foregone reproduction (especially for only 1 year within 7, which is the maximum predicted because the small number anticipated in any 1 year makes the probability that any individual would be impacted in this way twice in 7 years very low) has far less of an impact on population rates than mortality and a relatively small number of instances of foregone reproduction (as compared to the stock abundance and residual PBR) would not be expected to adversely affect the stock through effects on annual rates of recruitment or survival, especially given VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 the status of these stocks. Accordingly, we do not anticipate the relatively small number of individual northern fur seals or harbor seals that might be taken over repeated days within the year in a manner that results in 1 year of foregone reproduction to adversely affect the stocks through effects on rates of recruitment or survival, given the status of the stocks, which are respectively increasing and stable with abundances and residual PBRs of 14,050/30,968 and 449/1,598. For California sea lions, given the very high abundance and residual PBR (257,606 and 13,684, respectively), as well as the increasing status of the stock in the presence of similar levels of Navy activities over past years—the impacts of 0.71 annual mortalities, potential foregone reproduction for up to nine individuals in a year taken by tissue damage, and some relatively small number of individuals taken as a result of repeated behavioral harassment over a fair number of sequential days are not expected to adversely affect the stock through effects on annual rates of recruitment or survival. Similarly, for northern elephant seals, given the very high abundance and residual PBR (187,386 and 5,108, respectively), as well as the increasing status of the stock in the presence of similar levels of Navy activities over past years, the impacts of potential foregone reproduction for up to two individuals in a year taken by tissue damage and some relatively small number of individuals taken as a result of repeated behavioral harassment over a fair number of sequential days are not expected to adversely affect the stock through effects on annual rates of recruitment or survival. For these reasons, in consideration of all of the effects of the Navy’s activities combined (M/SI, Level A harassment, and Level B harassment), we have preliminarily determined that the authorized take proposed would have a negligible impact on all pinniped species and stocks. Preliminary Determination The 2018 HSTT final rule included a detailed discussion of all of the anticipated impacts on the affected species and stocks from serious injury or mortality, Level A harassment, and Level B harassment; impacts on habitat; and how the Navy’s mitigation and monitoring measures reduce the number and/or severity of adverse effects. We have evaluated how these impacts as well as an additional proposed take of two large whales by serious injury or mortality by vessel strike, and the proposed mitigation measures are expected to combine, annually, to affect PO 00000 Frm 00065 Fmt 4701 Sfmt 4702 68353 individuals of each species and stock. Those effects were then evaluated in the context of whether they are reasonably likely to impact reproductive success or survivorship of individuals and then, if so, further analyzed to determine whether there would be effects on annual rates of recruitment or survival that would adversely affect the species or stock. As described above, the basis for the negligible impact determination is the assessment of effects on annual rates of recruitment and survival. Accordingly, the analysis included in the 2018 HSTT final rule and 2020 HSTT final rule used annual activity levels, the best available science, and approved methods to predict the annual impacts to marine mammals, which were then analyzed in the context of whether each species or stock would incur more than a negligible impact based on anticipated adverse impacts to annual rates of recruitment or survival. As we have described above, none of the factors upon which the conclusions in the 2020 HSTT final rule were based have changed, with the exception of estimated take by vessel strike. Therefore, even though this proposed rule includes two additional takes by vessel strike, little has changed that would change our 2018 HSTT final rule and subsequent 2020 HSTT final rule analyses, and it is appropriate to rely on those analyses, as well as the new information and analysis discussed above, for this proposed rule. Based on the applicable information and analysis from the 2018 HSTT final rule and 2020 HSTT final rule, as updated with the information and analysis contained herein on the potential and likely effects of the specified activities on the affected marine mammals and their habitat, and taking into consideration the implementation of the monitoring and mitigation measures, NMFS preliminarily finds that the incidental take from the specified activities will have a negligible impact on all affected marine mammal species and stocks. Subsistence Harvest of Marine Mammals There are no subsistence uses or harvest of marine mammals in the geographic area affected by the specified activities. Therefore, NMFS has preliminarily determined that the total taking affecting species or stocks would not have an unmitigable adverse impact on the availability of such species or stocks for taking for subsistence purposes. E:\FR\FM\03OCP2.SGM 03OCP2 68354 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules ddrumheller on DSK120RN23PROD with PROPOSALS2 Classification Endangered Species Act There are nine marine mammal species under NMFS jurisdiction that are listed as endangered or threatened under the ESA with confirmed or possible occurrence in the HSTT Study Area: blue whale (Eastern and Central North Pacific stocks), fin whale (CA/OR/ WA and Hawaii stocks), gray whale (Western North Pacific stock), humpback whale (Mexico and Central America DPSs), sei whale (Eastern North Pacific and Hawaii stocks), sperm whale (CA/OR/WA and Hawaii stocks), false killer whale (Main Hawaiian Islands Insular), Hawaiian monk seal (Hawaii stock), and Guadalupe fur seal (Mexico to California). There is also ESA-designated critical habitat for Hawaiian monk seals and Main Hawaiian Islands Insular false killer whales. The Navy consulted with NMFS pursuant to section 7 of the ESA for HSTT activities. NMFS also consulted internally on the issuance of the 2018 HSTT regulations and LOAs under section 101(a)(5)(A) of the MMPA. NMFS issued a Biological Opinion on December 10, 2018 concluding that the issuance of the 2018 HSTT final rule and subsequent LOAs are not likely to jeopardize the continued existence of the threatened and endangered species under NMFS’ jurisdiction and are not likely to result in the destruction or adverse modification of critical habitat in the HSTT Study Area. The 2018 Biological Opinion included specified conditions under which NMFS would be required to reinitiate section 7 consultation. NMFS reviewed these specified conditions for the 2020 HSTT rulemaking and determined that reinitiation of consultation was not warranted. The incidental take statement that accompanied the 2018 Biological Opinion was amended to cover the 7-year period of the 2020 HSTT rule. The 2018 Biological Opinion for this action is available at https:// www.fisheries.noaa.gov/national/ marine-mammal-protection/incidentaltake-authorizations-military-readinessactivities. The 2018 Biological Opinion reinitiation clause (2), states that formal consultation should be reinitiated if ‘‘new information reveals effects of the agency action that may affect ESA-listed species or critical habitat in a manner or to an extent not previously considered.’’ Given the new information regarding the recent occurrence of large whale strikes by naval vessels in the southern California portion of the HSTT Study Area, as described herein, the Navy has reinitiated consultation with NMFS VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 pursuant to section 7 of the ESA for HSTT Study Area activities, and NMFS has also reinitiated consultation internally on the issuance of these proposed, revised regulations and LOAs under section 101(a)(5)(A) of the MMPA. National Marine Sanctuaries Act Federal agency actions that are likely to injure national marine sanctuary resources are subject to consultation with the Office of National Marine Sanctuaries (ONMS) under section 304(d) of the National Marine Sanctuaries Act (NMSA). There are two national marine sanctuaries in the HSTT Study Area, the Hawaiian Islands Humpback Whale National Marine Sanctuary and the Channel Islands National Marine Sanctuary. NMFS will work with NOAA’s ONMS to fulfill our responsibilities under the NMSA as warranted and will complete any NMSA requirements prior to a determination on the issuance of the final rule and LOAs. National Environmental Policy Act To comply with the National Environmental Policy Act of 1969 (NEPA; 42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216–6A, NMFS must evaluate our proposed actions and alternatives with respect to potential impacts on the human environment. NMFS participated as a cooperating agency on the 2018 HSTT FEIS/OEIS (published on October 26, 2018, https:// www.hstteis.com) which evaluated impacts from Navy training and testing activities in the HSTT Study Area for the reasonably foreseeable future (including through 2025). In accordance with 40 CFR 1506.3, NMFS independently reviewed and evaluated the 2018 HSTT FEIS/OEIS and determined that it was adequate and sufficient to meet our responsibilities under NEPA for the issuance of the 2018 HSTT final rule and associated LOAs. NMFS therefore adopted the 2018 HSTT FEIS/OEIS. In accordance with 40 CFR 1502.9 and the information and analysis contained in this proposed rule, the Navy and NMFS as a cooperating agency have made a preliminary determination that this proposed rule and any subsequent LOAs would not result in significant impacts that were not fully considered in the 2018 HSTT FEIS/OEIS. As indicated in this proposed rule, the Navy has made no substantial changes to the activities nor are there significant new circumstances or information relevant to environmental concerns or their PO 00000 Frm 00066 Fmt 4701 Sfmt 4702 impacts. NMFS will make a final NEPA determination prior to a decision whether to issue a final rule. Regulatory Flexibility Act The Office of Management and Budget has determined that this proposed rule is not significant for purposes of Executive Order 12866. Pursuant to the Regulatory Flexibility Act (RFA), the Chief Counsel for Regulation of the Department of Commerce has certified to the Chief Counsel for Advocacy of the Small Business Administration that this proposed rule, if adopted, would not have a significant economic impact on a substantial number of small entities. The RFA requires Federal agencies to prepare an analysis of a rule’s impact on small entities whenever the agency is required to publish a notice of proposed rulemaking. However, a Federal agency may certify, pursuant to 5 U.S.C. 605(b), that the action will not have a significant economic impact on a substantial number of small entities. The Navy is the sole entity that would be affected by this rulemaking, and the Navy is not a small governmental jurisdiction, small organization, or small business, as defined by the RFA. Any requirements imposed by an LOA issued pursuant to these regulations, and any monitoring or reporting requirements imposed by these regulations, would be applicable only to the Navy. NMFS does not expect the issuance of these regulations or the associated LOAs to result in any impacts to small entities pursuant to the RFA. Because this action, if adopted, would directly affect the Navy and not a small entity, NMFS concludes the action would not result in a significant economic impact on a substantial number of small entities. List of Subjects in 50 CFR Part 218 Exports, Fish, Imports, Incidental take, Indians, Labeling, Marine mammals, Navy, Penalties, Reporting and recordkeeping requirements, Seafood, Sonar, Transportation. Dated: September 26, 2023. Samuel D. Rauch III, Deputy Assistant Administrator for Regulatory Programs, National Marine Fisheries Service. For reasons set forth in the preamble, NMFS proposes to amend 50 CFR part 218 as follows: PART 218—REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE MAMMALS 1. The authority citation for part 218 continues to read as follows: ■ E:\FR\FM\03OCP2.SGM 03OCP2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules Authority: 16 U.S.C. 1361 et seq. ■ 2. Revise subpart H to read as follows: Subpart H—Taking and Importing Marine Mammals; U.S. Navy’s HawaiiSouthern California Training and Testing (HSTT) Sec. 218.70 Specified activity and geographical region. 218.71 Effective dates. 218.72 Permissible methods of taking. 218.73 Prohibitions. 218.74 Mitigation requirements. 218.75 Requirements for monitoring and reporting. 218.76 Letters of Authorization. 218.77 Renewals and modifications of Letters of Authorization. 218.78 and 218.79 [Reserved] Subpart H—Taking and Importing Marine Mammals; U.S. Navy’s HawaiiSouthern California Training and Testing (HSTT) § 218.70 Specified activity and geographical region. (a) Regulations in this subpart apply only to the U.S. Navy (Navy) for the taking of marine mammals that occurs in the area described in paragraph (b) of this section and that occurs incidental to the activities listed in paragraph (c) of this section. (b) The taking of marine mammals by the Navy under this subpart may be authorized in Letters of Authorization (LOAs) only if it occurs within the Hawaii-Southern California Training and Testing (HSTT) Study Area, which includes established operating and warning areas across the north-central Pacific Ocean, from the mean high tide line in Southern California west to Hawaii and the International Date Line. The HSTT Study Area includes the atsea areas of three existing range complexes, the Hawaii Range Complex (HRC), the Southern California Range Complex (SOCAL), and the Silver Strand Training Complex, and overlaps a portion of the Point Mugu Sea Range (PMSR). Also included in the HSTT Study Area are Navy pierside locations in Hawaii and Southern California, Pearl Harbor, San Diego Bay, and the transit corridor on the high seas where sonar training and testing may occur. (c) The taking of marine mammals by the Navy is only authorized if it occurs incidental to the Navy conducting training and testing activities, including: (1) Training. (i) Amphibious warfare; (ii) Anti-submarine warfare; (iii) Electronic warfare; (iv) Expeditionary warfare; (v) Mine warfare; (vi) Surface warfare; and (vii) Pile driving. (2) Testing. (i) Naval Air Systems Command Testing Activities; (ii) Naval Sea System Command Testing Activities; (iii) Office of Naval Research Testing Activities; and (iv) Naval Information Warfare Systems Command. § 218.71 Effective dates. Regulations in this subpart are effective from [date of publication of a final rule in the Federal Register] through December 20, 2025. § 218.72 Permissible methods of taking. (a) Under LOAs issued pursuant to §§ 216.106 of this chapter and 218.76, the Holder of the LOAs (hereinafter ‘‘Navy’’) may incidentally, but not intentionally, take marine mammals within the area described in § 218.70(b) by Level A harassment and Level B harassment associated with the use of active sonar and other acoustic sources and explosives as well as serious injury or mortality associated with vessel strikes and explosives, provided the activity is in compliance with all terms, conditions, and requirements of these regulations in this subpart and the applicable LOAs. (b) The incidental take of marine mammals by the activities listed in § 218.70(c) is limited to the following species: TABLE 1 TO PARAGRAPH (b) ddrumheller on DSK120RN23PROD with PROPOSALS2 Species Stock Blue whale ................................................................................................ Blue whale ................................................................................................ Bryde’s whale ........................................................................................... Bryde’s whale ........................................................................................... Fin whale .................................................................................................. Fin whale .................................................................................................. Humpback whale ...................................................................................... Humpback whale ...................................................................................... Humpback whale ...................................................................................... Minke whale .............................................................................................. Minke whale .............................................................................................. Sei whale .................................................................................................. Sei whale .................................................................................................. Gray whale ............................................................................................... Gray whale ............................................................................................... Sperm whale ............................................................................................. Sperm whale ............................................................................................. Dwarf sperm whale ................................................................................... Pygmy sperm whale ................................................................................. Kogia whales ............................................................................................ Baird’s beaked whale ............................................................................... Blainville’s beaked whale ......................................................................... Cuvier’s beaked whale ............................................................................. Cuvier’s beaked whale ............................................................................. Longman’s beaked whale ......................................................................... Mesoplodon spp ....................................................................................... Bottlenose dolphin .................................................................................... Bottlenose dolphin .................................................................................... Bottlenose dolphin .................................................................................... Bottlenose dolphin .................................................................................... Bottlenose dolphin .................................................................................... Bottlenose dolphin .................................................................................... VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 PO 00000 Frm 00067 Fmt 4701 Central North Pacific. Eastern North Pacific. Eastern Tropical Pacific. Hawaii. CA/OR/WA. Hawaii. Central America/Southern Mexico—CA/OR/WA. Mainland Mexico—CA/OR/WA. Hawaii. CA/OR/WA. Hawaii. Eastern North Pacific. Hawaii. Eastern North Pacific. Western North Pacific. CA/OR/WA. Hawaii. Hawaii. Hawaii. CA/OR/WA. CA/OR/WA. Hawaii. CA/OR/WA. Hawaii. Hawaii. CA/OR/WA. California Coastal. CA/OR/WA Offshore. Hawaii Pelagic. Kauai & Niihau. Oahu. 4-Island. Sfmt 4702 68355 E:\FR\FM\03OCP2.SGM 03OCP2 68356 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules TABLE 1 TO PARAGRAPH (b)—Continued Species Stock Bottlenose dolphin .................................................................................... False killer whale ...................................................................................... False killer whale ...................................................................................... False killer whale ...................................................................................... Fraser’s dolphin ........................................................................................ Killer whale ............................................................................................... Killer whale ............................................................................................... Killer whale ............................................................................................... Long-beaked common dolphin ................................................................. Melon-headed whale ................................................................................ Melon-headed whale ................................................................................ Northern right whale dolphin .................................................................... Pacific white-sided dolphin ....................................................................... Pantropical spotted dolphin ...................................................................... Pantropical spotted dolphin ...................................................................... Pantropical spotted dolphin ...................................................................... Pantropical spotted dolphin ...................................................................... Pygmy killer whale .................................................................................... Pygmy killer whale .................................................................................... Risso’s dolphin ......................................................................................... Risso’s dolphin ......................................................................................... Rough-toothed dolphin ............................................................................. Short-beaked common dolphin ................................................................ Short-finned pilot whale ............................................................................ Short-finned pilot whale ............................................................................ Spinner dolphin ......................................................................................... Spinner dolphin ......................................................................................... Spinner dolphin ......................................................................................... Spinner dolphin ......................................................................................... Striped dolphin .......................................................................................... Striped dolphin .......................................................................................... Dall’s porpoise .......................................................................................... California sea lion ..................................................................................... Guadalupe fur seal ................................................................................... Northern fur seal ....................................................................................... Harbor seal ............................................................................................... Hawaiian monk seal ................................................................................. Northern elephant seal ............................................................................. Hawaii. Hawaii Pelagic. Main Hawaiian Islands Insular. Northwestern Hawaiian Islands. Hawaii. Eastern North Pacific (ENP) Offshore. ENP Transient/West Coast Transient. Hawaii. California. Hawaiian Islands. Kohala Resident. CA/OR/WA. CA/OR/WA. Hawaii Island. Hawaii Pelagic. Oahu. 4-Island. Hawaii. Tropical. CA/OR/WA. Hawaii. Hawaii. CA/OR/WA. CA/OR/WA. Hawaii. Hawaii Island. Hawaii Pelagic. Kauai & Niihau. Oahu & 4-Island. CA/OR/WA. Hawaii. CA/OR/WA. U.S. Mexico. California. California. Hawaii. California. Note to Table 1: CA/OR/WA = California/Oregon/Washington. ddrumheller on DSK120RN23PROD with PROPOSALS2 § 218.73 Prohibitions. Notwithstanding incidental takings contemplated in § 218.72(a) and authorized by LOAs issued under §§ 216.106 of this chapter and 218.76, no person in connection with the activities listed in § 218.70(c) may: (a) Violate, or fail to comply with, the terms, conditions, and requirements of this subpart or an LOA issued under §§ 216.106 of this chapter and 218.76; (b) Take any marine mammal not specified in § 218.72(b); (c) Take any marine mammal specified in § 218.72(b) in any manner other than as specified in the LOAs; or (d) Take a marine mammal specified in § 218.72(b) if NMFS determines such taking results in more than a negligible impact on the species or stocks of such marine mammal. § 218.74 Mitigation requirements. When conducting the activities identified in § 218.70(c), the mitigation measures contained in any LOAs issued under §§ 216.106 of this chapter and VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 218.76 must be implemented. These mitigation measures include, but are not limited to: (a) Procedural mitigation. Procedural mitigation is mitigation that the Navy must implement whenever and wherever an applicable training or testing activity takes place within the HSTT Study Area for each applicable activity category or stressor category and includes acoustic stressors (i.e., active sonar, air guns, pile driving, weapons firing noise), explosive stressors (i.e., sonobuoys, torpedoes, medium-caliber and large-caliber projectiles, missiles and rockets, bombs, sinking exercises, mines, anti-swimmer grenades, and mat weave and obstacle loading), and physical disturbance and strike stressors (i.e., vessel movement; towed in-water devices; small-, medium-, and largecaliber non-explosive practice munitions; non-explosive missiles and rockets; and non-explosive bombs and mine shapes). (1) Environmental awareness and education. Appropriate Navy personnel PO 00000 Frm 00068 Fmt 4701 Sfmt 4702 (including civilian personnel) involved in mitigation and training or testing activity reporting under the specified activities will complete one or more modules identified in their career path training plan, as specified in the LOAs. (2) Active sonar. Active sonar includes low-frequency active sonar, mid-frequency active sonar, and highfrequency active sonar. For vessel-based activities, mitigation applies only to sources that are positively controlled and deployed from manned surface vessels (e.g., sonar sources towed from manned surface platforms). For aircraftbased activities, mitigation applies only to sources that are positively controlled and deployed from manned aircraft that do not operate at high altitudes (e.g., rotary-wing aircraft). Mitigation does not apply to active sonar sources deployed from unmanned aircraft or aircraft operating at high altitudes (e.g., maritime patrol aircraft). (i) Number of Lookouts and observation platform—(A) Hullmounted sources. One Lookout for E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules platforms with space or manning restrictions while underway (at the forward part of a small boat or ship) and platforms using active sonar while moored or at anchor (including pierside); and two Lookouts for platforms without space or manning restrictions while underway (at the forward part of the ship). (B) Sources that are not hull-mounted sources. One Lookout on the ship or aircraft conducting the activity. (ii) Mitigation zone and requirements. During the activity, at 1,000 yards (yd) Navy personnel must power down 6 decibels (dB), at 500 yd (457.2 m) Navy personnel must power down an additional 4 dB (for a total of 10 dB), and at 200 yd (182.9 m) Navy personnel must shut down for low-frequency active sonar ≥200 dB and hull-mounted mid-frequency active sonar; or at 200 yd (182.9 m) Navy personnel must shut down for low-frequency active sonar <200 dB, mid-frequency active sonar sources that are not hull-mounted, and high-frequency active sonar. (A) Prior to activity. Prior to the start of the activity (e.g., when maneuvering on station), Navy personnel must observe the mitigation zone for floating vegetation; if floating vegetation is observed, Navy personnel must relocate or delay the start of active sonar transmission until the mitigation zone is clear. Navy personnel must also observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must relocate or delay the start of active sonar transmission. (B) During the activity for lowfrequency active sonar at or above 200 dB and hull-mounted mid-frequency active sonar. During the activity for lowfrequency active sonar at or above 200 dB and hull-mounted mid-frequency active sonar, Navy personnel must observe the mitigation zone for marine mammals and power down active sonar transmission by 6 dB if marine mammals are observed within 1,000 yd (914.4 m) of the sonar source; power down by an additional 4 dB (for a total of 10 dB total) if marine mammals are observed within 500 yd (457.2 m) of the sonar source; and cease transmission if marine mammals are observed within 200 yd (182.9 m) of the sonar source. (C) During the activity for lowfrequency active sonar below 200 dB, mid-frequency active sonar sources that are not hull mounted, and highfrequency active sonar. During the activity for low-frequency active sonar below 200 dB, mid-frequency active sonar sources that are not hull mounted, and high-frequency active sonar, Navy personnel must observe the mitigation VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 zone for marine mammals and cease active sonar transmission if marine mammals are observed within 200 yd (182.9 m) of the sonar source. (D) Commencement/recommencement conditions after a marine mammal sighting before or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing or powering up active sonar transmission) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the sonar source; (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 10 minutes (min) for aircraft-deployed sonar sources or 30 min for vessel-deployed sonar sources; (4) Sonar source transit. For mobile activities, the active sonar source has transited a distance equal to double that of the mitigation zone size beyond the location of the last sighting; or (5) Bow-riding dolphins. For activities using hull-mounted sonar where a dolphin(s) is observed in the mitigation zone, the Lookout concludes that the dolphin(s) are deliberately closing in on the ship to ride the ship’s bow wave, and are therefore out of the main transmission axis of the sonar (and there are no other marine mammal sightings within the mitigation zone). (3) Air guns—(i) Number of Lookouts and observation platform. One Lookout positioned on a ship or pierside. (ii) Mitigation zone and requirements. 150 yd (137.2 m) around the air gun. (A) Prior to activity. Prior to the initial start of the activity (e.g., when maneuvering on station), Navy personnel must observe the mitigation zone for floating vegetation; if floating vegetation is observed, Navy personnel must relocate or delay the start until the mitigation zone is clear. Navy personnel must also observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must relocate or delay the start of air gun use. (B) During activity. During the activity, Navy personnel must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must cease air gun use. (C) Commencement/recommencement conditions after a marine mammal PO 00000 Frm 00069 Fmt 4701 Sfmt 4702 68357 sighting before or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing air gun use) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the air gun; (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 30 min; or (4) Air gun transit. For mobile activities, the air gun has transited a distance equal to double that of the mitigation zone size beyond the location of the last sighting. (4) Pile driving. Pile driving and pile extraction sound during Elevated Causeway System training. (i) Number of Lookouts and observation platform. One Lookout must be positioned on the shore, the elevated causeway, or a small boat. (ii) Mitigation zone and requirements. 100 yd (91.4 m) around the pile driver. (A) Prior to activity. Prior to the initial start of the activity (for 30 min), Navy personnel must observe the mitigation zone for floating vegetation; if floating vegetation is observed, Navy personnel must delay the start until the mitigation zone is clear. Navy personnel also must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must delay the start of pile driving or vibratory pile extraction. (B) During activity. During the activity, Navy personnel must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must cease impact pile driving or vibratory pile extraction. (C) Commencement/recommencement conditions after a marine mammal sighting before or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing pile driving or pile extraction) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the pile driving location; or E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68358 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 30 minutes. (5) Weapons firing noise. Weapons firing noise associated with large-caliber gunnery activities. (i) Number of Lookouts and observation platform. One Lookout must be positioned on the ship conducting the firing. Depending on the activity, the Lookout could be the same as the one provided for under ‘‘Explosive mediumcaliber and large-caliber projectiles’’ or under ‘‘Small-, medium-, and largecaliber non-explosive practice munitions’’ in paragraphs (a)(8)(i) and (a)(18)(i) of this section. (ii) Mitigation zone and requirements. Thirty degrees on either side of the firing line out to 70 yd from the muzzle of the weapon being fired. (A) Prior to activity. Prior to the start of the activity, Navy personnel must observe the mitigation zone for floating vegetation; if floating vegetation is observed, Navy personnel must relocate or delay the start of weapons firing until the mitigation zone is clear. Navy personnel must also observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must relocate or delay the start of weapons firing. (B) During activity. During the activity, Navy personnel must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must cease weapons firing. (C) Commencement/recommencement conditions after a marine mammal sighting before or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing weapons firing) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the firing ship; (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 30 min; or (4) Firing ship transit. For mobile activities, the firing ship has transited a distance equal to double that of the mitigation zone size beyond the location of the last sighting. (6) Explosive sonobuoys—(i) Number of Lookouts and observation platform. One Lookout must be positioned in an aircraft or on small boat. If additional platforms are participating in the VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 activity, Navy personnel positioned in those assets (e.g., safety observers, evaluators) must support observing the mitigation zone for applicable biological resources while performing their regular duties. (ii) Mitigation zone and requirements. 600 yd (548.6 m) around an explosive sonobuoy. (A) Prior to activity. Prior to the initial start of the activity (e.g., during deployment of a sonobuoy field, which typically lasts 20–30 min), Navy personnel must observe the mitigation zone for floating vegetation; if floating vegetation is observed, Navy personnel must relocate or delay the start of sonobuoy or source/receiver pair detonations until the mitigation zone is clear. Navy personnel must conduct passive acoustic monitoring for marine mammals and use information from detections to assist visual observations. Navy personnel also must visually observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must relocate or delay the start of sonobuoy or source/ receiver pair detonations. (B) During activity. During the activity, Navy personnel must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must cease sonobuoy or source/receiver pair detonations. (C) Commencement/recommencement conditions after a marine mammal sighting before or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing detonations) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the sonobuoy; or (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 10 min when the activity involves aircraft that have fuel constraints (e.g., helicopter), or 30 min when the activity involves aircraft that are not typically fuel constrained. (D) After activity. After completion of the activity (e.g., prior to maneuvering off station), when practical (e.g., when platforms are not constrained by fuel restrictions or mission-essential followon commitments), Navy personnel must observe for marine mammals in the vicinity of where detonations occurred; PO 00000 Frm 00070 Fmt 4701 Sfmt 4702 if any injured or dead marine mammals are observed, Navy personnel must follow established incident reporting procedures. If additional platforms are supporting this activity (e.g., providing range clearance), these Navy assets must assist in the visual observation of the area where detonations occurred. (7) Explosive torpedoes—(i) Number of Lookouts and observation platform. One Lookout positioned in an aircraft. If additional platforms are participating in the activity, Navy personnel positioned in those assets (e.g., safety observers, evaluators) must support observing the mitigation zone for applicable biological resources while performing their regular duties. (ii) Mitigation zone and requirements. 2,100 yd around the intended impact location. (A) Prior to activity. Prior to the initial start of the activity (e.g., during deployment of the target), Navy personnel must observe the mitigation zone for floating vegetation and jellyfish aggregations; if floating vegetation or jellyfish aggregations are observed, Navy personnel must relocate or delay the start of firing until the mitigation zone is clear. Navy personnel must conduct passive acoustic monitoring for marine mammals and use the information from detections to assist visual observations. Navy personnel also must visually observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must relocate or delay the start of firing. (B) During activity. During the activity, Navy personnel must observe for marine mammals and jellyfish aggregations; if marine mammals or jellyfish aggregations are observed, Navy personnel must cease firing. (C) Commencement/recommencement conditions after a marine mammal sighting before or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing firing) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the intended impact location; or (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 10 min when the activity involves aircraft that have fuel constraints, or 30 min when E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules the activity involves aircraft that are not typically fuel constrained. (D) After activity. After completion of the activity (e.g., prior to maneuvering off station), Navy personnel must when practical (e.g., when platforms are not constrained by fuel restrictions or mission-essential follow-on commitments), observe for marine mammals in the vicinity of where detonations occurred; if any injured or dead marine mammals are observed, Navy personnel must follow established incident reporting procedures. If additional platforms are supporting this activity (e.g., providing range clearance), these Navy assets must assist in the visual observation of the area where detonations occurred. (8) Explosive medium-caliber and large-caliber projectiles. Gunnery activities using explosive mediumcaliber and large-caliber projectiles. Mitigation applies to activities using a surface target. (i) Number of Lookouts and observation platform. One Lookout must be on the vessel or aircraft conducting the activity. For activities using explosive large-caliber projectiles, depending on the activity, the Lookout could be the same as the one described in ‘‘Weapons firing noise’’ in paragraph (a)(5)(i) of this section. If additional platforms are participating in the activity, Navy personnel positioned in those assets (e.g., safety observers, evaluators) must support observing the mitigation zone for applicable biological resources while performing their regular duties. (ii) Mitigation zone and requirements—(A) Air-to-surface activities. 200 yd (182.9 m) around the intended impact location for air-tosurface activities using explosive medium-caliber projectiles. (B) Surface-to-surface activities, medium-caliber. 600 yd (548.6 m) around the intended impact location for surface-to-surface activities using explosive medium-caliber projectiles. (C) Surface-to-surface activities, largecaliber. 1,000 yd (914.4 m) around the intended impact location for surface-tosurface activities using explosive largecaliber projectiles. (D) Prior to activity. Prior to the start of the activity (e.g., when maneuvering on station), Navy personnel must observe the mitigation zone for floating vegetation; if floating vegetation is observed, Navy personnel must relocate or delay the start of firing until the mitigation zone is clear. Navy personnel also must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must relocate or delay the start of firing. VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 (E) During activity. During the activity, Navy personnel must observe for marine mammals; if marine mammals are observed, Navy personnel must cease firing. (F) Commencement/recommencement conditions after a marine mammal sighting before or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing firing) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the intended impact location; (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 10 min for aircraft-based firing or 30 min for vesselbased firing; or for activities using mobile targets, the intended impact location has transited a distance equal to double that of the mitigation zone size beyond the location of the last sighting. (G) After activity. After completion of the activity (e.g., prior to maneuvering off station), Navy personnel must, when practical (e.g., when platforms are not constrained by fuel restrictions or mission-essential follow-on commitments), observe for marine mammals in the vicinity of where detonations occurred; if any injured or dead marine mammals are observed, Navy personnel must follow established incident reporting procedures. If additional platforms are supporting this activity (e.g., providing range clearance), these Navy assets must assist in the visual observation of the area where detonations occurred. (9) Explosive missiles and rockets. Aircraft-deployed explosive missiles and rockets. Mitigation applies to activities using a surface target. (i) Number of Lookouts and observation platform. One Lookout must be positioned in an aircraft. If additional platforms are participating in the activity, Navy personnel positioned in those assets (e.g., safety observers, evaluators) must support observing the mitigation zone for applicable biological resources while performing their regular duties. (ii) Mitigation zone and requirements—(A) Missiles or rockets with 0.6–20 lb net explosive weight. 900 yd (823 m) around the intended impact PO 00000 Frm 00071 Fmt 4701 Sfmt 4702 68359 location for missiles or rockets with 0.6– 20 lb net explosive weight. (B) Missiles with 21–500 lb net explosive weight. 2,000 yd (1,828.8 m) around the intended impact location for missiles with 21–500 lb net explosive weight. (C) Prior to activity. Prior to the initial start of the activity (e.g., during a flyover of the mitigation zone), Navy personnel must observe the mitigation zone for floating vegetation; if floating vegetation is observed, Navy personnel must relocate or delay the start of firing until the mitigation zone is clear. Navy personnel also must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must relocate or delay the start of firing. (D) During activity. During the activity, Navy personnel must observe for marine mammals; if marine mammals are observed, Navy personnel must cease firing. (E) Commencement/recommencement conditions after a marine mammal sighting before or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing firing) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the intended impact location; or (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 10 min when the activity involves aircraft that have fuel constraints, or 30 min when the activity involves aircraft that are not typically fuel constrained. (F) After activity. After completion of the activity (e.g., prior to maneuvering off station), Navy personnel must, when practical (e.g., when platforms are not constrained by fuel restrictions or mission-essential follow-on commitments), observe for marine mammals in the vicinity of where detonations occurred; if any injured or dead marine mammals are observed, Navy personnel must follow established incident reporting procedures. If additional platforms are supporting this activity (e.g., providing range clearance), these Navy assets will assist in the visual observation of the area where detonations occurred. (10) Explosive bombs—(i) Number of Lookouts and observation platform. One E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68360 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules Lookout must be positioned in an aircraft conducting the activity. If additional platforms are participating in the activity, Navy personnel positioned in those assets (e.g., safety observers, evaluators) must support observing the mitigation zone for applicable biological resources while performing their regular duties. (ii) Mitigation zone and requirements. 2,500 yd (2,286 m) around the intended target. (A) Prior to activity. Prior to the initial start of the activity (e.g., when arriving on station), Navy personnel must observe the mitigation zone for floating vegetation; if floating vegetation is observed, Navy personnel must relocate or delay the start of bomb deployment until the mitigation zone is clear. Navy personnel also must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must relocate or delay the start of bomb deployment. (B) During activity. During the activity (e.g., during target approach), Navy personnel must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must cease bomb deployment. (C) Commencement/recommencement conditions after a marine mammal sighting before or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing bomb deployment) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the intended target; (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 10 min; or for activities using mobile targets, the intended target has transited a distance equal to double that of the mitigation zone size beyond the location of the last sighting. (D) After activity. After completion of the activity (e.g., prior to maneuvering off station), Navy personnel must, when practical (e.g., when platforms are not constrained by fuel restrictions or mission-essential follow-on commitments), observe for marine mammals in the vicinity of where detonations occurred; if any injured or dead marine mammals are observed, Navy personnel must follow established incident reporting procedures. If VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 additional platforms are supporting this activity (e.g., providing range clearance), these Navy assets must assist in the visual observation of the area where detonations occurred. (11) Sinking exercises—(i) Number of Lookouts and observation platform. Two Lookouts (one must be positioned in an aircraft and one must be positioned on a vessel). If additional platforms are participating in the activity, Navy personnel positioned in those assets (e.g., safety observers, evaluators) must support observing the mitigation zone for applicable biological resources while performing their regular duties. (ii) Mitigation zone and requirements. 2.5 nautical miles (nmi) around the target ship hulk. (A) Prior to activity. Prior to the initial start of the activity (90 min prior to the first firing), Navy personnel must conduct aerial observations of the mitigation zone for floating vegetation and jellyfish aggregations; if floating vegetation or jellyfish aggregations are observed, Navy personnel must delay the start of firing until the mitigation zone is clear. Navy personnel also must conduct aerial observations of the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must delay the start of firing. (B) During activity. During the activity, Navy personnel must conduct passive acoustic monitoring for marine mammals and use the information from detections to assist visual observations. Navy personnel must visually observe the mitigation zone for marine mammals from the vessel; if marine mammals are observed, Navy personnel must cease firing. Immediately after any planned or unplanned breaks in weapons firing of longer than 2 hours, Navy personnel must observe the mitigation zone for marine mammals from the aircraft and vessel; if marine mammals are observed, Navy personnel must delay recommencement of firing. (C) Commencement/recommencement conditions after a marine mammal sighting before or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing firing) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the target ship hulk; or PO 00000 Frm 00072 Fmt 4701 Sfmt 4702 (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 30 minutes. (D) After activity. After completion of the activity (for 2 hours after sinking the vessel or until sunset, whichever comes first), Navy personnel must observe for marine mammals in the vicinity of where detonations occurred; if any injured or dead marine mammals are observed, Navy personnel must follow established incident reporting procedures. If additional platforms are supporting this activity (e.g., providing range clearance), these Navy assets will assist in the visual observation of the area where detonations occurred. (12) Explosive mine countermeasure and neutralization activities—(i) Number of Lookouts and observation platform—(A) Smaller mitigation zone. One Lookout must be positioned on a vessel or in an aircraft when implementing the smaller mitigation zone. (B) Larger mitigation zone. Two Lookouts (one must be positioned in an aircraft and one must be on a small boat) when implementing the larger mitigation zone. (C) Additional platforms. If additional platforms are participating in the activity, Navy personnel positioned in those assets (e.g., safety observers, evaluators) must support observing the mitigation zone for applicable biological resources while performing their regular duties. (ii) Mitigation zone and requirements. (A) Activities using 0.1–5 lb net explosive weight. 600 yd (548.6 m) around the detonation site for activities using 0.1–5 lb net explosive weight. (B) Activities using 6–650 lb net explosive weight. 2,100 yd (1,920.2 m) around the detonation site for activities using 6–650 lb net explosive weight (including high explosive target mines). (C) Prior to activity. Prior to the initial start of the activity (e.g., when maneuvering on station; typically, 10 min when the activity involves aircraft that have fuel constraints, or 30 min when the activity involves aircraft that are not typically fuel constrained), Navy personnel must observe the mitigation zone for floating vegetation; if floating vegetation is observed, Navy personnel must relocate or delay the start of detonations until the mitigation zone is clear. Navy personnel also must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must relocate or delay the start of detonations. (D) During activity. During the activity, Navy personnel must observe the mitigation zone for marine mammals, concentrations of seabirds, E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules and individual foraging seabirds; if marine mammals, concentrations of seabirds, or individual foraging seabirds are observed, Navy personnel must cease detonations. (E) Commencement/recommencement conditions after a marine mammal sighting before or during the activity or a sighting of seabird concentrations or individual foraging seabirds during the activity. Navy personnel must allow a sighted animal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing detonations) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to detonation site; or (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 10 min when the activity involves aircraft that have fuel constraints, or 30 min when the activity involves aircraft that are not typically fuel constrained. (F) After activity. After completion of the activity (typically 10 min when the activity involves aircraft that have fuel constraints, or 30 min when the activity involves aircraft that are not typically fuel constrained), Navy personnel must observe for marine mammals in the vicinity of where detonations occurred; if any injured or dead marine mammals are observed, Navy personnel must follow established incident reporting procedures. If additional platforms are supporting this activity (e.g., providing range clearance), these Navy assets must assist in the visual observation of the area where detonations occurred. (13) Explosive mine neutralization activities involving Navy divers—(i) Number of Lookouts and observation platform—(A) Smaller mitigation zone. Two Lookouts (two small boats with one Lookout each, or one Lookout must be on a small boat and one must be in a rotary-wing aircraft) when implementing the smaller mitigation zone. (B) Larger mitigation zone. Four Lookouts (two small boats with two Lookouts each), and a pilot or member of an aircrew must serve as an additional Lookout if aircraft are used during the activity, when implementing the larger mitigation zone. (C) Divers. All divers placing the charges on mines will support the Lookouts while performing their regular duties and will report applicable VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 sightings to their supporting small boat or Range Safety Officer. (D) Additional platforms. If additional platforms are participating in the activity, Navy personnel positioned in those assets (e.g., safety observers, evaluators) must support observing the mitigation zone for applicable biological resources while performing their regular duties. (ii) Mitigation zone and requirements—(A) Activities under positive control using 0.1–20 lb net explosive weight. 500 yd (457.2 m) around the detonation site during activities under positive control using 0.1–20 lb net explosive weight. (B) Activities under positive control using 21–60 lb net explosive weight charges. 1,000 yd (914.4 m) around the detonation site during all activities using time-delay fuses (0.1–29 lb net explosive weight) and during activities under positive control using 21–60 lb net explosive weight charges. (C) Prior to activity. Prior to the initial start of the activity (e.g., when maneuvering on station for activities under positive control; 30 min for activities using time-delay firing devices), Navy personnel must observe the mitigation zone for floating vegetation; if floating vegetation is observed, Navy personnel must relocate or delay the start of detonations or fuse initiation until the mitigation zone is clear. Navy personnel also must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must relocate or delay the start of detonations or fuse initiation. (D) During activity. During the activity, Navy personnel must observe the mitigation zone for marine mammals, concentrations of seabirds, and individual foraging seabirds (in the water and not on shore); if marine mammals, concentrations of seabirds, or individual foraging seabirds are observed, Navy personnel must cease detonations or fuse initiation. To the maximum extent practicable depending on mission requirements, safety, and environmental conditions, Navy personnel must position boats near the mid-point of the mitigation zone radius (but outside of the detonation plume and human safety zone), must position themselves on opposite sides of the detonation location (when two boats are used), and must travel in a circular pattern around the detonation location with one Lookout observing inward toward the detonation site and the other observing outward toward the perimeter of the mitigation zone. If used, Navy aircraft must travel in a circular pattern around the detonation location to the PO 00000 Frm 00073 Fmt 4701 Sfmt 4702 68361 maximum extent practicable. Navy personnel must not set time-delay firing devices (0.1–29 lb net explosive weight) to exceed 10 minutes. (E) Commencement/recommencement conditions after a marine mammal sighting before or during the activity or a sighting of seabird concentrations or individual foraging seabirds during the activity. Navy personnel must allow a sighted animal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing detonations) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the detonation site; or (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 10 min during activities under positive control with aircraft that have fuel constraints, or 30 min during activities under positive control with aircraft that are not typically fuel constrained and during activities using time-delay firing devices. (F) After activity. After completion of an activity (for 30 min), the Navy must observe for marine mammals for 30 minutes. Navy personnel must observe for marine mammals in the vicinity of where detonations occurred; if any injured or dead marine mammals are observed, Navy personnel must follow established incident reporting procedures. If additional platforms are supporting this activity (e.g., providing range clearance), these Navy assets must assist in the visual observation of the area where detonations occurred. (14) Maritime security operations— anti-swimmer grenades—(i) Number of Lookouts and observation platform. One Lookout must be positioned on the small boat conducting the activity. If additional platforms are participating in the activity, Navy personnel positioned in those assets (e.g., safety observers, evaluators) must support observing the mitigation zone for applicable biological resources while performing their regular duties. (ii) Mitigation zone and requirements. 200 yd (182.9 m) around the intended detonation location. (A) Prior to activity. Prior to the initial start of the activity (e.g., when maneuvering on station), Navy personnel must observe the mitigation zone for floating vegetation; if floating vegetation is observed, Navy personnel E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68362 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules must relocate or delay the start of detonations until the mitigation zone is clear. Navy personnel also must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must relocate or delay the start of detonations. (B) During activity. During the activity, Navy personnel must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must cease detonations. (C) Commencement/recommencement conditions after a marine mammal sighting before or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing detonations) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the intended detonation location; (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 30 min; or (4) Detonation location transit. The intended detonation location has transited a distance equal to double that of the mitigation zone size beyond the location of the last sighting. (D) After activity. After completion of the activity (e.g., prior to maneuvering off station), Navy personnel must, when practical (e.g., when platforms are not constrained by fuel restrictions or mission-essential follow-on commitments), observe for marine mammals in the vicinity of where detonations occurred; if any injured or dead marine mammals are observed, Navy personnel must follow established incident reporting procedures. If additional platforms are supporting this activity (e.g., providing range clearance), these Navy assets will assist in the visual observation of the area where detonations occurred. (15) Underwater demolition multiple charge—mat weave and obstacle loading exercises—(i) Number of Lookouts and observation platform. Two Lookouts (one must be positioned on a small boat and one must be positioned on shore from an elevated platform). If additional platforms are participating in the activity, Navy personnel positioned in those assets (e.g., safety observers, evaluators) must support observing the mitigation zone VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 for applicable biological resources while performing their regular duties. (ii) Mitigation zone and requirements. 700 yd (640.1 m) around the intended detonation location. (A) Prior to activity. Prior to the initial start of the activity, or 30 min prior to the first detonation, the Lookout positioned on a small boat must observe the mitigation zone for floating vegetation and marine mammals; if floating vegetation or marine mammals are observed, Navy personnel must delay the start of detonations until the mitigation zone is clear. For 10 min prior to the first detonation, the Lookout positioned on shore must use binoculars to observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must delay the start of detonations. (B) During activity. During the activity, Navy personnel must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must cease detonations. (C) Commencement/recommencement conditions after a marine mammal sighting before or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing detonations) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the detonation location; or (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 10 min (as determined by the Navy shore observer). (D) After activity. After completion of the activity (for 30 min), the Lookout positioned on a small boat must observe for marine mammals in the vicinity of where detonations occurred; if any injured or dead marine mammals are observed, Navy personnel must follow established incident reporting procedures. If additional platforms are supporting this activity (e.g., providing range clearance), these Navy assets must assist in the visual observation of the area where detonations occurred. (16) Vessel movement. The mitigation will not be applied if: the vessel’s safety is threatened; the vessel is restricted in its ability to maneuver (e.g., during launching and recovery of aircraft or landing craft, during towing activities, when mooring); the vessel is operated PO 00000 Frm 00074 Fmt 4701 Sfmt 4702 autonomously; or when impracticable based on mission requirements (e.g., during Amphibious Assault—Battalion Landing exercise). (i) Number of Lookouts and observation platform. One Lookout must be on the vessel that is underway. (ii) Mitigation zone and requirements—(A) Whales. 500 yd (457.2 m) around whales. (B) Marine mammals other than whales. 200 yd (182.9 m) around all other marine mammals (except bowriding dolphins and pinnipeds hauled out on man-made navigational structures, port structures, and vessels). (iii) During the activity. When underway, Navy personnel must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must maneuver (which may include reducing speed as the mission or circumstances allow) to maintain distance. (iv) Incident reporting procedures. If a marine mammal vessel strike occurs, Navy personnel must follow the established incident reporting procedures. (v) Post-strike alerts. Navy personnel must send alerts to Navy vessels of increased risk of strike following any reported Navy vessel strike in the HSTT Study Area. (vi) Large whale aggregation alerts. Navy personnel must issue real-time notifications to Navy vessels of large whale aggregations (four or more whales) within 1 nmi (1.9 km) of a Navy vessel in the area between 32–33 degrees North and 117.2–119.5 degrees West. (17) Towed in-water devices. Mitigation applies to devices that are towed from a manned surface platform or manned aircraft. The mitigation will not be applied if the safety of the towing platform or in-water device is threatened. (i) Number of Lookouts and observation platform. One Lookout must be positioned on a manned towing platform. (ii) Mitigation zone and requirements. 250 yd (228.6 m) around marine mammals. (iii) During the activity. During the activity (i.e., when towing an in-water device), Navy personnel must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must maneuver to maintain distance. (18) Small-, medium-, and largecaliber non-explosive practice munitions. Mitigation applies to activities using a surface target. (i) Number of Lookouts and observation platform. One Lookout must E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules be positioned on the platform conducting the activity. Depending on the activity, the Lookout could be the same as the one described for ‘‘Weapons firing noise’’ in paragraph (a)(5)(i) of this section. (ii) Mitigation zone and requirements. 200 yd (182.9 m) around the intended impact location. (A) Prior to activity. Prior to the start of the activity (e.g., when maneuvering on station), Navy personnel must observe the mitigation zone for floating vegetation; if floating vegetation is observed, Navy personnel must relocate or delay the start of firing until the mitigation zone is clear. Navy personnel also must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must relocate or delay the start of firing. (B) During activity. During the activity, Navy personnel must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must cease firing. (C) Commencement/recommencement conditions after a marine mammal sighting before or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing firing) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the intended impact location; (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 10 min for aircraft-based firing or 30 min for vesselbased firing; or (4) Impact location transit. For activities using a mobile target, the intended impact location has transited a distance equal to double that of the mitigation zone size beyond the location of the last sighting. (19) Non-explosive missiles and rockets. Aircraft-deployed nonexplosive missiles and rockets. Mitigation applies to activities using a surface target. (i) Number of Lookouts and observation platform. One Lookout must be positioned in an aircraft. (ii) Mitigation zone and requirements. 900 yd around the intended impact location. (A) Prior to activity. Prior to the initial start of the activity (e.g., during a fly- VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 over of the mitigation zone), Navy personnel must observe the mitigation zone for floating vegetation; if floating vegetation is observed, Navy personnel must relocate or delay the start of firing until the mitigation zone is clear. Navy personnel also must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must relocate or delay the start of firing. (B) During activity. During the activity, Navy personnel must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must cease firing. (C) Commencement/recommencement conditions after a marine mammal sighting prior to or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing firing) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the intended impact location; or (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 10 min when the activity involves aircraft that have fuel constraints, or 30 min when the activity involves aircraft that are not typically fuel constrained. (20) Non-explosive bombs and mine shapes. Non-explosive bombs and nonexplosive mine shapes during mine laying activities. (i) Number of Lookouts and observation platform. One Lookout must be positioned in an aircraft. (ii) Mitigation zone and requirements. 1,000 yd (914.4 m) around the intended target. (A) Prior to activity. Prior to the initial start of the activity (e.g., when arriving on station), Navy personnel must observe the mitigation zone for floating vegetation; if floating vegetation is observed, Navy personnel must relocate or delay the start of bomb deployment or mine laying until the mitigation zone is clear. Navy personnel also must observe the mitigation zone for marine mammals; if marine mammals are observed, Navy personnel must relocate or delay the start of bomb deployment or mine laying. (B) During activity. During the activity (e.g., during approach of the target or intended minefield location), Navy PO 00000 Frm 00075 Fmt 4701 Sfmt 4702 68363 personnel must observe the mitigation zone for marine mammals and, if marine mammals are observed, Navy personnel must cease bomb deployment or mine laying. (C) Commencement/recommencement conditions after a marine mammal sighting prior to or during the activity. Navy personnel must allow a sighted marine mammal to leave the mitigation zone prior to the initial start of the activity (by delaying the start) or during the activity (by not recommencing bomb deployment or mine laying) until one of the following conditions has been met: (1) Observed exiting. The animal is observed exiting the mitigation zone; (2) Thought to have exited. The animal is thought to have exited the mitigation zone based on a determination of its course, speed, and movement relative to the intended target or minefield location; (3) Clear from additional sightings. The mitigation zone has been clear from any additional sightings for 10 min; or (4) Target transit. For activities using mobile targets, the intended target has transited a distance equal to double that of the mitigation zone size beyond the location of the last sighting. (b) Mitigation areas. In addition to procedural mitigation, Navy personnel must implement mitigation measures within mitigation areas to avoid or reduce potential impacts on marine mammals. (1) Mitigation areas for marine mammals in the Hawaii Range Complex for sonar, explosives, and vessel strikes—(i) Mitigation area requirements—(A) Hawaii Island Mitigation Area (year-round)—(1) MF1 surface ship hull-mounted midfrequency active sonar, MF4 dipping sonar, or explosives. Except as provided in paragraph (b)(1)(i)(A)(2) of this section, Navy personnel must not conduct more than 300 hours of MF1 surface ship hull-mounted midfrequency active sonar or 20 hours of MF4 dipping sonar annually, or use explosives that could potentially result in takes of marine mammals during training and testing. (2) National security exception. Should national security require conduct of more than 300 hours of MF1 surface ship hull-mounted midfrequency active sonar or 20 hours of MF4 dipping sonar, or use of explosives that could potentially result in the take of marine mammals during training or testing, Naval units must obtain permission from the appropriate designated Command authority prior to commencement of the activity. Navy personnel must provide NMFS with advance notification and include the E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68364 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules information (e.g., sonar hours or explosives usage) in its annual activity reports submitted to NMFS. (B) 4-Islands Region Mitigation Area (November 15–April 15 for active sonar; year-round for explosives)—(1) MF1 surface ship hull-mounted midfrequency active sonar or explosives. Except as provided in paragraph (b)(1)(i)(B)(2) of this section, Navy personnel must not use MF1 surface ship hull-mounted mid-frequency active sonar or explosives that could potentially result in takes of marine mammals during training and testing. (2) National security exception. Should national security require use of MF1 surface ship hull-mounted midfrequency active sonar or explosives that could potentially result in the take of marine mammals during training or testing, Naval units must obtain permission from the appropriate designated Command authority prior to commencement of the activity. Navy personnel must provide NMFS with advance notification and include the information (e.g., sonar hours or explosives usage) in its annual activity reports submitted to NMFS. (C) Humpback Whale Special Reporting Areas (December 15–April 15). Navy personnel must report the total hours of surface ship hull-mounted mid-frequency active sonar used in the special reporting areas in its annual training and testing activity reports submitted to NMFS. (D) Humpback Whale Awareness Notification Message Area (November– April)—(1) Seasonal awareness notification message. Navy personnel must issue a seasonal awareness notification message to alert ships and aircraft operating in the area to the possible presence of concentrations of large whales, including humpback whales. (2) Vessel instruction. To maintain safety of navigation and to avoid interactions with large whales during transits, Navy personnel must instruct vessels to remain vigilant to the presence of large whale species (including humpback whales). (3) Awareness notification message use. Platforms must use the information from the awareness notification message to assist their visual observation of applicable mitigation zones during training and testing activities and to aid in the implementation of procedural mitigation. (ii) [Reserved] (2) Mitigation areas for marine mammals in the southern California portion of the study area for sonar, explosives, and vessel strikes—(i) Mitigation area requirements—(A) San VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 Diego Arc, San Nicolas Island, and Santa Monica/Long Beach Mitigation Areas (June 1–October 31)—(1) MF1 surface ship hull-mounted midfrequency active sonar. Except as provided in paragraph (b)(2)(i)(A)(2) of this section, Navy personnel must not conduct more than a total of 200 hours of MF1 surface ship hull-mounted midfrequency active sonar in the combined areas, excluding normal maintenance and systems checks, during training and testing. (2) National security exception. Should national security require conduct of more than 200 hours of MF1 surface ship hull-mounted midfrequency active sonar in the combined areas during training and testing (excluding normal maintenance and systems checks), Naval units must obtain permission from the appropriate designated Command authority prior to commencement of the activity. Navy personnel must provide NMFS with advance notification and include the information (e.g., sonar hours) in its annual activity reports submitted to NMFS. (3) Explosives in San Diego Arc Mitigation Area. Except as provided in paragraph (b)(2)(i)(A)(4) of this section, within the San Diego Arc Mitigation Area, Navy personnel must not use explosives that could potentially result in the take of marine mammals during large-caliber gunnery, torpedo, bombing, and missile (including 2.75-inch rockets) activities during training and testing. (4) National security exception. Should national security require use of explosives that could potentially result in the take of marine mammals during large-caliber gunnery, torpedo, bombing, and missile (including 2.75-inch rockets) activities during training or testing within the San Diego Arc Mitigation Area, Naval units must obtain permission from the appropriate designated Command authority prior to commencement of the activity. Navy personnel must provide NMFS with advance notification and include the information (e.g., explosives usage) in its annual activity reports submitted to NMFS. (5) Explosives in San Nicolas Island Mitigation Area. Except as provided in paragraph (b)(2)(i)(A)(6) of this section, within the San Nicolas Island Mitigation Area, Navy personnel must not use explosives that could potentially result in the take of marine mammals during mine warfare, large-caliber gunnery, torpedo, bombing, and missile (including 2.75-inch rockets) activities during training. PO 00000 Frm 00076 Fmt 4701 Sfmt 4702 (6) National security exception. Should national security require use of explosives that could potentially result in the take of marine mammals during mine warfare, large-caliber gunnery, torpedo, bombing, and missile (including 2.75-inch rockets) activities during training in the San Nicolas Island Mitigation Area, Naval units must obtain permission from the appropriate designated Command authority prior to commencement of the activity. Navy personnel must provide NMFS with advance notification and include the information (e.g., explosives usage) in its annual activity reports submitted to NMFS. (7) Explosives in the Santa Monica/ Long Beach Mitigation Area. Except as provided in paragraph (b)(2)(i)(A)(8) of this section, within the Santa Monica/ Long Beach Mitigation Area, Navy personnel must not use explosives that could potentially result in the take of marine mammals during mine warfare, large-caliber gunnery, torpedo, bombing, and missile (including 2.75-inch rockets) activities during training and testing. (8) National security exception. Should national security require use of explosives that could potentially result in the take of marine mammals during mine warfare, large-caliber gunnery, torpedo, bombing, and missile (including 2.75-inch rockets) activities during training or testing in the Santa Monica/Long Beach Mitigation Area, Naval units must obtain permission from the appropriate designated Command authority prior to commencement of the activity. Navy personnel must provide NMFS with advance notification and include the information (e.g., explosives usage) in its annual activity reports submitted to NMFS. (B) Santa Barbara Island Mitigation Area (year-round)—(1) MF1 surface ship hull-mounted mid-frequency active sonar or explosives. Except as provided in paragraph (b)(2)(i)(B)(2) of this section, Navy personnel must not use MF1 surface ship hull-mounted midfrequency active sonar during training or testing, or explosives that could potentially result in the take of marine mammals during medium-caliber or large-caliber gunnery, torpedo, bombing, and missile (including 2.75-inch rockets) activities during training. (2) National security exception. Should national security require use of MF1 surface ship hull-mounted midfrequency active sonar during training or testing, or explosives that could potentially result in the take of marine mammals during medium-caliber or large-caliber gunnery, torpedo, bombing, E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules and missile (including 2.75-inch rockets) activities during training, Naval units must obtain permission from the appropriate designated Command authority prior to commencement of the activity. Navy personnel must provide NMFS with advance notification and include the information (e.g., sonar hours or explosives usage) in its annual activity reports submitted to NMFS. (C) Spring Large Whale Awareness Notification Message—(1) Awareness notification message. Navy personnel must issue an awareness notification message to alert ships and aircraft operating in the area to the possible presence of concentrations of large whales, including blue whales, fin whales, and humpback whales. (2) Applicable period. This message must apply to a period that is based on predicted oceanographic conditions for a given year. (3) Marine mammals and vessel transit. To maintain safety of navigation and to avoid interactions with large whales during transits, Navy personnel must emphasize to vessels that when a marine mammal is spotted, this may be an indicator that additional marine mammals are present nearby, and increased vigilance and awareness of Navy personnel is warranted. (4) Platform use of message. Platforms must use the information from the awareness notification messages to assist their visual observation of applicable mitigation zones during training and testing activities and to aid in the implementation of procedural mitigation. (D) Gray Whale (November–March) and Fin Whale (November–May) Awareness Notification Message Areas—(1) Seasonal awareness message. Navy personnel must issue a seasonal awareness notification message to alert ships and aircraft operating in the area to the possible presence of concentrations of large whales, including gray whales, and fin whales. (2) Marine mammals and vessel transit. To maintain safety of navigation and to avoid interactions with large whales during transits, Navy personnel must instruct vessels to remain vigilant to the presence of large whale species. (3) Platform use of message. Platforms must use the information from the awareness notification messages to assist their visual observation of applicable mitigation zones during training and testing activities and to aid in the implementation of procedural mitigation. (ii) [Reserved] VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 § 218.75 Requirements for monitoring and reporting. (a) Unauthorized take. Navy personnel must notify NMFS immediately (or as soon as operational security considerations allow) if the specified activity identified in § 218.70 is thought to have resulted in the mortality or serious injury of any marine mammals, or in any Level A harassment or Level B harassment take of marine mammals not identified in this subpart. (b) Monitoring and reporting under the LOAs. The Navy must conduct all monitoring and reporting required under the LOAs, including abiding by the HSTT Study Area monitoring program. Details on program goals, objectives, project selection process, and current projects are available at www.navymarinespeciesmonitoring.us. (c) Notification of injured, live stranded, or dead marine mammals. The Navy must consult the Notification and Reporting Plan, which sets out notification, reporting, and other requirements when dead, injured, or live stranded marine mammals are detected. The Notification and Reporting Plan is available at https:// www.fisheries.noaa.gov/national/ marine-mammal-protection/incidentaltake-authorizations-military-readinessactivities. (d) Changes in Lookout Policies. The Navy must report changes in its Lookout policies to NMFS as soon as practicable after a change is made. (e) Annual HSTT Study Area marine species monitoring report. The Navy must submit an annual report of the HSTT Study Area monitoring describing the implementation and results from the previous calendar year. Data collection methods must be standardized across range complexes and study areas to allow for comparison in different geographic locations. The report must be submitted to the Director, Office of Protected Resources, NMFS, either within 3 months after the end of the calendar year, or within 3 months after the conclusion of the monitoring year, to be determined by the Adaptive Management process. This report will describe progress of knowledge made with respect to intermediate scientific objectives within the HSTT Study Area associated with the Integrated Comprehensive Monitoring Program (ICMP). Similar study questions must be treated together so that progress on each topic can be summarized across all Navy ranges. The report need not include analyses and content that does not provide direct assessment of cumulative progress on the monitoring plan study questions. As an alternative, the Navy may submit a multi-Range PO 00000 Frm 00077 Fmt 4701 Sfmt 4702 68365 Complex annual Monitoring Plan report to fulfill this requirement. Such a report will describe progress of knowledge made with respect to monitoring study questions across multiple Navy ranges associated with the ICMP. Similar study questions must be treated together so that progress on each topic can be summarized across multiple Navy ranges. The report need not include analyses and content that does not provide direct assessment of cumulative progress on the monitoring study question. This will continue to allow the Navy to provide a cohesive monitoring report covering multiple ranges (as per ICMP goals), rather than entirely separate reports for the HSTT, Gulf of Alaska, Mariana Islands, and Northwest Study Areas. (f) Annual HSTT Study Area training exercise report and testing activity report. Each year, the Navy must submit two preliminary reports (Quick Look Report) detailing the status of authorized sound sources within 21 days after the anniversary of the date of issuance of each LOA to the Director, Office of Protected Resources, NMFS. Each year, the Navy must submit detailed reports to the Director, Office of Protected Resources, NMFS, within 3 months after the 1-year anniversary of the date of issuance of the LOA. The HSTT annual Training Exercise Report and Testing Activity Report can be consolidated with other exercise reports from other range complexes in the Pacific Ocean for a single Pacific Exercise Report, if desired. The annual reports must contain information on major training exercises (MTEs), Sinking Exercise (SINKEX) events, and a summary of all sound sources used, including within specific mitigation reporting areas, as described in paragraph (e)(3) through (5) of this section. The analysis in the detailed reports must be based on the accumulation of data from the current year’s report and data collected from previous reports. The detailed reports must contain information identified in paragraphs (e)(1) through (7) of this section. (1) MTEs. This section of the report must contain the following information for MTEs conducted in the HSTT Study Area. (i) Exercise information (for each MTE). (A) Exercise designator. (B) Date that exercise began and ended. (C) Location. (D) Number and types of active sonar sources used in the exercise. (E) Number and types of passive acoustic sources used in exercise. E:\FR\FM\03OCP2.SGM 03OCP2 ddrumheller on DSK120RN23PROD with PROPOSALS2 68366 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules (F) Number and types of vessels, aircraft, and other platforms participating in exercise. (G) Total hours of all active sonar source operation. (H) Total hours of each active sonar source bin. (I) Wave height (high, low, and average) during exercise. (ii) Individual marine mammal sighting information for each sighting in each exercise where mitigation was implemented: (A) Date, time, and location of sighting. (B) Species (if not possible, indication of whale/dolphin/pinniped). (C) Number of individuals. (D) Initial Detection Sensor (e.g., sonar, Lookout). (E) Indication of specific type of platform observation was made from (including, for example, what type of surface vessel or testing platform). (F) Length of time observers maintained visual contact with marine mammal. (G) Sea state. (H) Visibility. (I) Sound source in use at the time of sighting. (J) Indication of whether animal was less than 200 yd (182.9 m), 200 to 500 yd (182.9 to 457.2 m), 500 to 1,000 yd (457.2 m to 914.4 m), 1,000 to 2,000 yd (914.4 m to 1,828.8 m), or greater than 2,000 yd (1,828.8 m) from sonar source. (K) Whether operation of sonar sensor was delayed, or sonar was powered or shut down, and how long the delay. (L) If source in use was hull-mounted, true bearing of animal from the vessel, true direction of vessel’s travel, and estimation of animal’s motion relative to vessel (opening, closing, parallel). (M) Lookouts must report, in plain language and without trying to categorize in any way, the observed behavior of the animal(s) (such as animal closing to bow ride, paralleling course/speed, floating on surface and not swimming, etc.) and if any calves were present. (iii) An evaluation (based on data gathered during all of the MTEs) of the effectiveness of mitigation measures designed to minimize the received level to which marine mammals may be exposed. This evaluation must identify the specific observations that support any conclusions the Navy reaches about the effectiveness of the mitigation. (2) SINKEXs. This section of the report must include the following information for each SINKEX completed that year. (i) Exercise information (gathered for each SINKEX). (A) Location. VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 (B) Date and time exercise began and ended. (C) Total hours of observation by Lookouts before, during, and after exercise. (D) Total number and types of explosive source bins detonated. (E) Number and types of passive acoustic sources used in exercise. (F) Total hours of passive acoustic search time. (G) Number and types of vessels, aircraft, and other platforms participating in exercise. (H) Wave height in feet (high, low, and average) during exercise. (I) Narrative description of sensors and platforms utilized for marine mammal detection and timeline illustrating how marine mammal detection was conducted. (ii) Individual marine mammal observation (by Navy Lookouts) information for each sighting where mitigation was implemented. (A) Date/Time/Location of sighting. (B) Species (if not possible, indicate whale, dolphin, or pinniped). (C) Number of individuals. (D) Initial detection sensor (e.g., sonar or Lookout). (E) Length of time observers maintained visual contact with marine mammal. (F) Sea state. (G) Visibility. (H) Whether sighting was before, during, or after detonations/exercise, and how many minutes before or after. (I) Distance of marine mammal from actual detonations (or target spot if not yet detonated): Less than 200 yd (182.9 m), 200 to 500 yd (182.9 to 457.2 m), 500 to 1,000 yd (457.2 m to 914.4 m), 1,000 to 2,000 yd (914.4 m to 1,828.8 m), or greater than 2,000 yd (1,828.8 m). (J) Lookouts must report, in plain language and without trying to categorize in any way, the observed behavior of the animal(s) (such as animal closing to bow ride, paralleling course/speed, floating on surface and not swimming etc.), including speed and direction and if any calves were present. (K) The report must indicate whether explosive detonations were delayed, ceased, modified, or not modified due to marine mammal presence and for how long. (L) If observation occurred while explosives were detonating in the water, indicate munition type in use at time of marine mammal detection. (3) Summary of sources used. This section of the report must include the following information summarized from the authorized sound sources used in all training and testing events: PO 00000 Frm 00078 Fmt 4701 Sfmt 4702 (i) Total annual hours or quantity (per the LOA) of each bin of sonar or other acoustic sources (e.g., pile driving and air gun activities); and (ii) Total annual expended/detonated ordinance (missiles, bombs, sonobuoys, etc.) for each explosive bin. (4) Humpback Whale Special Reporting Area (December 15–April 15). The Navy must report the total hours of operation of surface ship hull-mounted mid-frequency active sonar used in the special reporting area. (5) HSTT Study Area Mitigation Areas. The Navy must report any use that occurred as specifically described in these areas. Information included in the classified annual reports may be used to inform future adaptive management of activities within the HSTT Study Area. (6) Geographic information presentation. The reports must present an annual (and seasonal, where practical) depiction of training and testing bin usage (as well as pile driving activities) geographically across the HSTT Study Area. (7) Sonar exercise notification. The Navy must submit to NMFS (contact as specified in the LOA) an electronic report within 15 calendar days after the completion of any MTE indicating: (i) Location of the exercise; (ii) Beginning and end dates of the exercise; and (iii) Type of exercise. (g) Seven-year close-out comprehensive training and testing activity report. This report must be included as part of the 2025 annual training and testing report. This report must provide the annual totals for each sound source bin with a comparison to the annual allowance and the 7-year total for each sound source bin with a comparison to the 7-year allowance. Additionally, if there were any changes to the sound source allowance, this report must include a discussion of why the change was made and include the analysis to support how the change did or did not result in a change in the 2018 HSTT FEIS/OEIS and final rule determinations. The draft report must be submitted within 3 months after the expiration of this subpart to the Director, Office of Protected Resources, NMFS. NMFS must submit comments on the draft close-out report, if any, within 3 months of receipt. The report will be considered final after the Navy has addressed NMFS’ comments, or 3 months after the submittal of the draft if NMFS does not provide comments. § 218.76 Letters of Authorization. (a) To incidentally take marine mammals pursuant to the regulations in E:\FR\FM\03OCP2.SGM 03OCP2 Federal Register / Vol. 88, No. 190 / Tuesday, October 3, 2023 / Proposed Rules this subpart, the Navy must apply for and obtain LOAs in accordance with § 216.106 of this chapter. (b) LOAs, unless suspended or revoked, may be effective for a period of time not to exceed December 20, 2025. (c) If an LOA expires prior to December 20, 2025, the Navy may apply for and obtain a renewal of the LOA. (d) In the event of projected changes to the activity or to mitigation, monitoring, or reporting (excluding changes made pursuant to the adaptive management provision of § 218.77(c)(1)) required by an LOA issued under this subpart, the Navy must apply for and obtain a modification of the LOA as described in § 218.77. (e) Each LOA must set forth: (1) Permissible methods of incidental taking; (2) Geographic areas for incidental taking; (3) Means of effecting the least practicable adverse impact (i.e., mitigation) on the species or stocks of marine mammals and their habitat; and (4) Requirements for monitoring and reporting. (f) Issuance of the LOA(s) must be based on a determination that the level of taking is consistent with the findings made for the total taking allowable under the regulations in this subpart. (g) Notice of issuance or denial of the LOA(s) must be published in the Federal Register within 30 days of a determination. § 218.77 Renewals and modifications of Letters of Authorization. ddrumheller on DSK120RN23PROD with PROPOSALS2 (a) An LOA issued under §§ 216.106 of this chapter and 218.76 for the VerDate Sep<11>2014 20:43 Oct 02, 2023 Jkt 262001 activity identified in § 218.70(c) may be renewed or modified upon request by the applicant, provided that: (1) The planned specified activity and mitigation, monitoring, and reporting measures, as well as the anticipated impacts, are the same as those described and analyzed for the regulations in this subpart (excluding changes made pursuant to the adaptive management provision in paragraph (c)(1) of this section); and (2) NMFS determines that the mitigation, monitoring, and reporting measures required by the previous LOA(s) were implemented. (b) For LOA modification or renewal requests by the applicant that include changes to the activity or to the mitigation, monitoring, or reporting measures (excluding changes made pursuant to the adaptive management provision in paragraph (c)(1) of this section) that do not change the findings made for the regulations or result in no more than a minor change in the total estimated number of takes (or distribution by species or stock or years), NMFS may publish a notice of planned LOA in the Federal Register, including the associated analysis of the change, and solicit public comment before issuing the LOA. (c) An LOA issued under §§ 216.106 of this chapter and 218.76 may be modified by NMFS under the following circumstances: (1) Adaptive management. After consulting with the Navy regarding the practicability of the modifications, NMFS may modify (including adding or removing measures) the existing PO 00000 Frm 00079 Fmt 4701 Sfmt 9990 68367 mitigation, monitoring, or reporting measures if doing so creates a reasonable likelihood of more effectively accomplishing the goals of the mitigation and monitoring. (i) Possible sources of data that could contribute to the decision to modify the mitigation, monitoring, or reporting measures in an LOA include: (A) Results from the Navy’s monitoring from the previous year(s); (B) Results from other marine mammal and/or sound research or studies; or (C) Any information that reveals marine mammals may have been taken in a manner, extent, or number not authorized by the regulations in this subpart or subsequent LOAs. (ii) If, through adaptive management, the modifications to the mitigation, monitoring, or reporting measures are substantial, NMFS will publish a notice of planned LOA in the Federal Register and solicit public comment. (2) Emergencies. If NMFS determines that an emergency exists that poses a significant risk to the well-being of the species or stocks of marine mammals specified in LOAs issued pursuant to §§ 216.106 of this chapter and 218.76, an LOA may be modified without prior notice or opportunity for public comment. Notice would be published in the Federal Register within 30 days of the action. §§ 218.78–218.79 [Reserved] [FR Doc. 2023–21499 Filed 10–2–23; 8:45 am] BILLING CODE 3510–22–P E:\FR\FM\03OCP2.SGM 03OCP2

Agencies

[Federal Register Volume 88, Number 190 (Tuesday, October 3, 2023)]
[Proposed Rules]
[Pages 68290-68367]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-21499]

[[Page 68289]]

Vol. 88

Tuesday,

No. 190

October 3, 2023

Part II

Department of Commerce

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National Oceanic and Atmospheric Administration

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50 CFR Part 218

Taking and Importing Marine Mammals; Taking Marine Mammals Incidental
to the U.S. Navy Training and Testing Activities in the Hawaii-Southern
California Training and Testing Study Area; Proposed Rule

Federal Register / Vol. 88 , No. 190 / Tuesday, October 3, 2023 /
Proposed Rules

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 230817-0197]
RIN 0648-BL72

Taking and Importing Marine Mammals; Taking Marine Mammals
Incidental to the U.S. Navy Training and Testing Activities in the
Hawaii-Southern California Training and Testing Study Area

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.

ACTION: Proposed rule; request for comments and information.

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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) to
modify the regulations and Letters of Authorization (LOAs) authorizing
the take of marine mammals incidental to Navy training and testing
activities conducted in the Hawaii-Southern California Training and
Testing (HSTT) Study Area between 2018 and 2025. In 2021, two separate
U.S. Navy vessels struck unidentified large whales on two separate
occasions, one whale in June 2021 and one whale in July 2021, in waters
off Southern California. The takes by vessel strike of the two whales
by the U.S. Navy were covered by the existing regulations and LOAs,
which authorize the U.S. Navy to take up to three large whales by
serious injury or mortality by vessel strike between 2018 and 2025. The
Navy reanalyzed the potential of vessel strike in the HSTT Study Area,
including the recent strikes and as a result, requested two additional
takes of large whales by serious injury or mortality by vessel strike
for the remainder of the current regulatory period. In May 2023, a U.S.
Navy vessel struck a large whale in waters off Southern California.
NMFS reanalyzed the potential for vessel strike following the May 2023
strike and proposes to authorize two additional takes of large whales
by serious injury or mortality by vessel strike for the remainder of
the current regulatory period (two takes in addition to the three takes
authorized in the current regulations). Pursuant to the Marine Mammal
Protection Act (MMPA), NMFS is requesting comments on the proposed
promulgation of modified regulations and associated LOAs for the Navy
governing this additional incidental taking of marine mammals. NMFS
will consider public comments prior to issuing any final rule and
making final decisions on the issuance of the requested LOAs. Agency
responses to public comments will be provided in the notice of the
final decision. The Navy's activities qualify as military readiness
activities pursuant to the MMPA, as amended by the National Defense
Authorization Act for Fiscal Year 2004 (2004 NDAA).

DATES: Comments and information must be received no later than November
17, 2023.

ADDRESSES: Submit all electronic public comments via the Federal e-
Rulemaking Portal. Go to https://www.regulations.gov and enter NOAA-
NMFS-2023-0102 in the Search box. Click on the ``Comment'' icon,
complete the required fields, and enter or attach your comments.
Instructions: Comments sent by any other method, to any other
address or individual, or received after the end of the comment period
may not be considered by NMFS. All comments received are a part of the
public record and will generally be posted for public viewing on
www.regulations.gov without change. All personal identifying
information (e.g., name, address), confidential business information,
or otherwise sensitive information submitted voluntarily by the sender
will be publicly accessible. NMFS will accept anonymous comments (enter
``N/A'' in the required fields if you wish to remain anonymous).
A copy of the Navy's applications, NMFS' proposed and final rules
and subsequent LOAs for the existing (2020) and previous (2018)
regulations, and other supporting documents and documents cited herein
may be obtained online at: www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities. In case of problems accessing these documents, please use
the contact listed here (see FOR FURTHER INFORMATION CONTACT).

FOR FURTHER INFORMATION CONTACT: Leah Davis, Office of Protected
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Purpose of Regulatory Action

These proposed regulations, issued under the authority of the MMPA
(16 U.S.C. 1361 et seq.), would modify the current regulations, which
allow for the authorization of take of marine mammals incidental to the
Navy's training and testing activities (which qualify as military
readiness activities) from the use of sonar and other transducers, in-
water detonations, air guns, impact pile driving/vibratory extraction,
and the movement of vessels throughout the HSTT Study Area (50 CFR part
218, subpart H; hereafter ``2020 HSTT regulations'').
NMFS received a request from the Navy to modify the existing
regulations and LOAs to authorize two additional takes of large whales
by serious injury or mortality by vessel strike over the remainder of
the HSTT regulatory period. The current HSTT regulations and LOAs
authorize the incidental take, by serious injury or mortality, of three
large whales by vessel strike. Here, in consideration of the best
available science, including updated information related to vessel
strikes, NMFS analyzes and proposes to authorize the incidental serious
injury or mortality by vessel strike of five large whales over the
effective period of the regulations (December 2018-December 2025). The
effective period remains unchanged from the existing regulations.
Further, the Navy's proposed activities remain unchanged; however, this
proposed rule includes two additional mitigation measures and revision
of two existing mitigation measures to further reduce the probability
of vessel strike. With the exception of these new mitigation measures
and revisions to two existing mitigation measures, the required
mitigation and monitoring measures remain unchanged.

Background

The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are issued or, if the taking is limited to harassment, the public is
provided with notice of the proposed incidental take authorization and
the opportunity to review and submit comments.
An authorization for incidental takings shall be granted if NMFS
finds that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other means of effecting the least practicable adverse
impact on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of

[[Page 68291]]

similar significance, and on the availability of such species or stocks
for taking for certain subsistence uses (referred to in this rulemaking
as ``mitigation measures''); and requirements pertaining to the
monitoring and reporting of such takings. The MMPA defines ``take'' to
mean to harass, hunt, capture, or kill, or attempt to harass, hunt,
capture, or kill any marine mammal. The Preliminary Analysis and
Negligible Impact Determination section below discusses the definition
of ``negligible impact.''
The 2004 NDAA (Pub. L. 108-136) amended section 101(a)(5) of the
MMPA to remove the ``small numbers'' and ``specified geographical
region'' provisions indicated above and amended the definition of
``harassment'' as applied to a ``military readiness activity.'' The
definition of harassment for military readiness activities (section
3(18)(B) of the MMPA) is (i) any act that injures or has the
significant potential to injure a marine mammal or marine mammal stock
in the wild (Level A Harassment); or (ii) any act that disturbs or is
likely to disturb a marine mammal or marine mammal stock in the wild by
causing disruption of natural behavioral patterns, including, but not
limited to, migration, surfacing, nursing, breeding, feeding, or
sheltering, to a point where such behavioral patterns are abandoned or
significantly altered (Level B harassment). In addition, the 2004 NDAA
amended the MMPA as it relates to military readiness activities such
that the least practicable adverse impact analysis shall include
consideration of personnel safety, practicality of implementation, and
impact on the effectiveness of the military readiness activity.
The NDAA for Fiscal Year 2019 (2019 NDAA) (Pub. L. 115-232),
amended the MMPA to allow incidental take rules for military readiness
activities under section 101(a)(5)(A) to be issued for up to 7 years.
Prior to this amendment, all incidental take rules under section
101(a)(5)(A) were limited to 5 years.
Under the MMPA implementing regulations, incidental take
regulations may be modified, in whole or in part, as new information is
developed and after notice and opportunity for public comment (50 CFR
216.105). An LOA must be withdrawn or suspended if, after notice and
opportunity for public comment, NMFS determines that the regulations
are not being substantially complied with, or the taking is having, or
may have, more than a negligible impact on species or stock. Id. at
216.106(e). Note, in its application, Navy relied on Sec. Sec. 218.76,
and 218.77. These sections outline the process for modification of an
LOA without modifying the applicable incidental take regulation. These
sections do not apply here because the Navy requested modification of
the 2020 HSTT regulations.

Summary of Request

On December 27, 2018, NMFS issued a 5-year final rule governing the
taking of marine mammals incidental to Navy training and testing
activities conducted in the HSTT Study Area (83 FR 66846; hereafter
``2018 HSTT final rule''). Previously, on August 13, 2018, and towards
the end of the time period in which NMFS was processing the Navy's
request for the 2018 regulations, the 2019 NDAA amended the MMPA for
military readiness activities to allow incidental take regulations to
be issued for up to 7 years instead of the previous 5 years. The Navy's
training and testing activities conducted in the HSTT Study Area
qualify as military readiness activities pursuant to the MMPA, as
amended by the 2004 NDAA. On March 11, 2019, the Navy submitted an
application requesting that NMFS extend the 2018 HSTT regulations and
associated LOAs such that they would cover take incidental to 7 years
of training and testing activities instead of 5, extending the
expiration date from December 20, 2023 to December 20, 2025. On July
10, 2020, NOAA Fisheries issued regulations to govern the taking of
marine mammals incidental to the training and testing activities
conducted in the HSTT Study Area over the course of 7 years,
effectively extending the effective period from December 20, 2023 to
December 20, 2025.
On March 31, 2022, NMFS received an adequate and complete
application (2022 Navy application) from the Navy requesting that NMFS
modify the existing regulations and LOAs to authorize two additional
takes of large whales by serious injury or mortality by vessel strike
over the remainder of the HSTT authorization period. The 2020 HSTT
regulations (50 CFR part 218, subpart H) and LOAs authorize the take of
marine mammals from the Navy's training and testing activities in the
HSTT Study Area through December 20, 2025. These regulations and LOAs
authorize the take of three large whales by serious injury or mortality
by vessel strike.
The Navy's 2022 request is based upon new information regarding
U.S. Navy vessel strikes off the coast of Southern California. As
described in the 2022 Navy application, in 2021, two separate U.S. Navy
vessels struck unidentified large whales off the coast of Southern
California on two separate occasions, one whale in June 2021 and one
whale in July 2021. Separately, a foreign naval vessel struck two fin
whales off the coast of Southern California in May 2021.
In the 2022 Navy application, the Navy proposes no changes to the
nature of the specified activities covered by the 2020 HSTT final rule.
The Navy states that the level of activity within and between years
would be consistent with that previously analyzed in the 2020 HSTT
final rule, and all activities would be conducted within the same
boundaries of the HSTT Study Area identified in the 2020 HSTT final
rule. The training and testing activities (e.g., equipment and sources
used, exercises conducted) are identical to those described and
analyzed in the 2020 HSTT final rule, and the mitigation, monitoring,
and reporting measures are similar to those described and analyzed in
the 2020 HSTT final rule. The only changes included in the Navy's
request are for additional take by serious injury or mortality by
vessel strike.
The Navy's mission is to organize, train, equip, and maintain
combat-ready naval forces capable of winning wars, deterring
aggression, and maintaining freedom of the seas. This mission is
mandated by Federal law (10 U.S.C. 8062), which ensures the readiness
of the naval forces of the United States. The Navy executes this
responsibility by establishing and executing training programs,
including at-sea training and exercises, and ensuring naval forces have
access to the ranges, operating areas (OPAREAs), and airspace needed to
develop and maintain skills for conducting naval activities.
For a summary of the training and testing activities within the
HSTT Study Area, see the Navy's previous rulemaking and LOA
applications submitted for HSTT Phase III activities (October 13, 2017
initial rulemaking and LOA application (hereafter ``2017 Navy
application'') and March 11, 2019 extension rulemaking and LOA
application (hereafter ``2019 Navy application'')) and the 2020 HSTT
regulations that were subsequently promulgated, which can be found at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities. These
activities are deemed by the Navy necessary to accomplish military
readiness requirements and are anticipated to continue into the
reasonably foreseeable future. The 2022 Navy application and this
proposed rule cover training and testing activities that would occur
over the remainder of the effective period of the current regulations,
valid from the

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publication date of the final rule, if issued, through December 20,
2025.

Summary of the Proposed Regulations

NMFS is proposing to modify the incidental take regulations and
associated LOAs to cover the same Navy activities covered by the 2020
HSTT regulations but authorize five takes of large whales by serious
injury or mortality by vessel strike (two takes in addition to the
three takes authorized in the current regulations). In its 2022
application, the Navy proposes no additional changes and explains that
its training and testing activities, including the level of vessel use,
remain unchanged. Nearly all mitigation, monitoring, and reporting
measures remain unchanged with the exception of two additional
mitigation measures, revision of two existing mitigation measures, and
an additional reporting measure resulting from discussions between the
Navy and NMFS.
In response to the Navy's request, we focus our analysis on the new
information related to vessel strike. We also review any new
information that may be pertinent to our analysis of the impacts from
all other activities that comprise Navy's specified activity, and our
analysis of mitigation, monitoring, and reporting. Where there is any
new information pertinent to the descriptions, analyses, or findings
required to authorize the incidental take for military readiness
activities under MMPA section 101(a)(5)(A), that information is
provided in the appropriate sections below. Where there is no new
information or any new information does not change our previous
analysis or findings, we indicate as such and refer the reader to the
original analysis in the 2018 HSTT proposed and final rule, 2020 HSTT
final rule or the 2019 HSTT Final Environmental Impact Statement
(FEIS)/Overseas Environmental Impact Statement (OEIS).
After reviewing all new information and as discussed below, we
largely find that our previous analyses and findings remain current and
applicable. For vessel strike, we provide a new analysis and propose
authorizing two additional takes of large whales, for a total of five
takes by serious injury or mortality by vessel strike over the 7-year
period. We consider authorizing these additional takes after analyzing
the best available information and after considering the effects of the
entire specified activity and the total taking as required by MMPA
section 101(a)(5)(A). When setting forth the permissible methods of
taking pursuant to the activity and other means of effecting the least
practicable adverse impact on the species or stock, we propose
requiring new and modified mitigation and also consider whether to
require any new or modified mitigation for the entire specified
activity.
The proposed regulatory language included at the end of this
proposed rule, which would be published at 50 CFR part 218, subpart H,
remains largely the same as that under the HSTT 2020 regulations,
except for a small number of technical changes related to the Navy's
2022 request, new and revised mitigation measures, and a new reporting
measure. Therefore, in this proposed rule, we refer the reader to
complete analyses described in the 2018 HSTT final rule or an updated
analysis in the 2020 HSTT final rule, where appropriate.
Below is a list of the regulatory documents referenced in this
proposed rule. The list indicates the short name by which the document
is referenced in this proposed rule as well as the full titles of the
cited documents. All of the documents can be found at:
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities and https://www.hstteis.com/.
NMFS June 26, 2018, Hawaii-Southern California Training
and Testing (HSTT) proposed rule (83 FR 29872; 2018 HSTT proposed
rule);
NMFS December 27, 2018, Hawaii-Southern California
Training and Testing (HSTT) final rule (83 FR 66846; 2018 HSTT final
rule);
NMFS September 13, 2019, Hawaii-Southern California
Training and Testing (HSTT) proposed rule (84 FR 48388; 2019 HSTT
proposed rule);
NMFS July 10, 2020, Hawaii-Southern California Training
and Testing (HSTT) final rule (85 FR 41780; 2020 HSTT final rule);
Navy October 13, 2017, MMPA rulemaking and LOA application
(2017 Navy application);
Navy March 11, 2019, MMPA rulemaking and LOA extension
application (2019 Navy application);
Navy March 31, 2022, MMPA rulemaking and LOA revision
application (2022 Navy application); and
October 26, 2018, Hawaii-Southern California Training and
Testing (HSTT) Final Environmental Impact Statement/Overseas
Environmental Impact Statement (FEIS/OEIS) (2018 HSTT FEIS/OEIS).

Description of the Specified Activity

The Navy requests authorization to take marine mammals incidental
to conducting training and testing activities. The Navy has determined
that acoustic and explosives stressors are most likely to result in
impacts on marine mammals that could rise to the level of harassment.
In addition to take by harassment, the Navy has determined that vessel
movement may result in serious injury or mortality to marine mammals.
Detailed descriptions of these activities are provided in chapter 2 of
the 2018 HSTT FEIS/OEIS and in the 2017 Navy application.

Overview of Training and Testing Activities

The Navy routinely trains in the HSTT Study Area in preparation for
national defense missions. Training and testing activities and
components covered in the 2022 Navy application are described in detail
in the Overview of Training and Testing Activities sections of the 2018
HSTT proposed rule, the 2018 HSTT final rule, and chapter 2
(Description of Proposed Action and Alternatives) of the 2018 HSTT
FEIS/OEIS (https://www.hstteis.com/). Each military training and testing
activity described meets mandated Fleet requirements to deploy ready
forces. The Navy proposes no changes to the specified activities
described and analyzed in the 2018 HSTT final rule and subsequent 2020
HSTT final rule. The boundaries of the HSTT Study Area (see figure 2-1
of the 2019 Navy application); the dates and duration of the
activities; and the training and testing activities (e.g., equipment
and sources used, exercises conducted) analyzed in this proposed rule
are identical to those described and analyzed in the 2020 HSTT final
rule and therefore, are not repeated herein. Please see the 2020 HSTT
final rule for more information. The manner of vessel movement
presented in this proposed rule is also identical to that analyzed in
the 2020 HSTT final rule.

Vessel Strike

Vessel strikes are not specific to any particular training or
testing activity but rather, a limited, sporadic, and incidental result
of Navy vessel movement within the HSTT Study Area. Vessel strikes from
commercial, recreational, and military vessels are known to seriously
injure and occasionally kill cetaceans (Abramson et al. 2011; Berman-
Kowalewski et al. 2010; Calambokidis, 2012; Douglas et al. 2008;
Laggner, 2009; Lammers et al. 2003; Van der Hoop et al. 2012; Van der
Hoop et al. 2013; Crum et al. 2019), although reviews of the literature
on vessel strikes mainly involve collisions between commercial vessels
and whales (Jensen and Silber, 2003; Laist et al. 2001). Vessel speed,
size, and mass are

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all important factors in determining both the potential likelihood and
impacts of a vessel strike to marine mammals (Conn and Silber, 2013;
Gende et al. 2011; Silber et al. 2010; Vanderlaan and Taggart, 2007;
Wiley et al. 2016). For large vessels, speed and angle of approach can
influence the severity of a strike.
Navy vessels transit at speeds that are optimal for fuel
conservation or to meet training and testing requirements. Small craft
(for purposes of this analysis, less than 18 m in length) have much
more variable speeds (0-50+ knots (kn; 0-92.6 kilometers (km) per
hour), dependent on the activity). Submarines generally operate at
speeds in the range of 8-13 kn (14.8-24.1 km per hour), and the average
speed of large Navy ships range between 10 and 15 kn (18.5 and 27.8 km
per hour). While these speeds are considered averages and
representative of most events, some vessels need to operate outside of
these parameters for certain times or during certain activities. For
example, to produce the required relative wind speed over the flight
deck, an aircraft carrier engaged in flight operations must adjust its
speed through the water accordingly. Also, there are other instances
such as launch and recovery of a small rigid hull inflatable boat;
vessel boarding, search, and seizure training events; or retrieval of a
target when vessels would be dead in the water or moving slowly ahead
to maintain steerage. There are a few specific events, including high-
speed tests of newly constructed vessels, where vessels would operate
at higher speeds. By comparison, this is slower than most commercial
vessels where full speed for a container ship is typically 24 kn (44.4
km per hour; Bonney and Leach, 2010).
Large Navy vessels (greater than 18 m in length) within the
offshore areas of range complexes and testing ranges operate
differently from commercial vessels in ways that may reduce the
probability of whale collisions. Surface ships operated by or for the
Navy have multiple personnel assigned to stand watch at all times when
a ship or surfaced submarine is moving through the water (underway). A
primary duty of personnel standing watch on surface ships is to detect
and report all objects and disturbances sighted in the water that may
indicate a threat to the vessel and its crew, such as debris, a
periscope, surfaced submarine, or surface disturbance. Per vessel
safety requirements, personnel standing watch also report any marine
mammals sighted in the path of the vessel as a standard collision
avoidance procedure. All vessels proceed at a safe speed so they can
take proper and effective action to avoid a collision with any sighted
object or disturbance and can be stopped within a distance appropriate
to the prevailing circumstances and conditions. As described in the
Standard Operating Procedures section, the Navy utilizes Lookouts to
avoid collisions, and Lookouts are also trained to spot marine mammals
so that vessels may change course or take other appropriate action to
avoid collisions. Should a vessel strike occur, we consider that it
would likely result in incidental take in the form of serious injury
and/or mortality and, accordingly, for the purposes of the analysis, we
assume that any vessel strike would result in serious injury or
mortality.
The Navy proposes no changes to the nature of the specified
activities, the training and testing activities, the manner of vessel
movement, the speeds at which vessels operate, the number of vessels
that would be used during various activities, or the locations in which
Navy vessel activity would be concentrated within the HSTT Study Area
described in the 2018 HSTT final rule and referenced in the 2020 HSTT
final rule.

Vessel Movement

Vessels used as part of the planned activities include ships,
submarines, unmanned vessels, and boats ranging in size from small, 22
ft (7 m) rigid hull inflatable boats to aircraft carriers with lengths
up to 1,092 ft (333 m). The average speed of large Navy ships ranges
between 10 and 15 kn (18.5 and 27.8 km per hour) and submarines
generally operate at speeds in the range of 8-13 kn (14.8-24.1 km per
hour) while a few specialized vessels can travel at faster speeds.
Small craft (for purposes of this analysis, less than 18 m in length)
have much more variable speeds (0-50+ kn (0-92.6 km per hour),
dependent on the activity) but generally range from 10 to 14 kn (18.5
to 25.9 km per hour). From unpublished Navy data, average median speed
for large Navy ships in the HSTT Study Area from 2011-2015 varied from
5-10 kn (9.2-18.5 km per hour) with variations by ship class and
location (i.e., slower speeds close to the coast). While these speeds
for large and small craft are representative of most events, some
vessels need to temporarily operate outside of these parameters.
Typical speed of Navy vessels in HSTT core high use areas from 2014-
2018 were between 10 and 15 kn (18.5 and 27.8 km per hour; Starcovic
and Mintz 2021). This core area is a region including the approaches to
San Diego, and immediate offshore areas west of San Diego, centered
north and south of San Clemente Island. A full description of Navy
vessels that are used during training and testing activities can be
found in the 2017 Navy application and chapter 2 (Description of
Proposed Action and Alternatives) of the 2018 HSTT FEIS/OEIS.
The number of Navy vessels used in the HSTT Study Area varies based
on military training and testing requirements, deployment schedules,
annual budgets, and other dynamic factors. Most training and testing
activities involve the use of vessels. These activities could be widely
dispersed throughout the HSTT Study Area but would typically be
conducted near naval ports, piers, and range areas. Navy vessel traffic
would be especially concentrated near San Diego, California and Pearl
Harbor, Hawaii. Based on historical data, we anticipate the annual
number of at-sea hours by U.S. Navy vessels in the HSTT action area
will be around 26,800 hours per year (Starcovic and Mintz 2021). We
expect that about 25 percent of this vessel activity would occur within
the Hawaii Range Complex (HRC) and 75 percent within the Southern
California Range Complex (SOCAL; Mintz 2016). There is no seasonal
differentiation in Navy vessel use because of continual operational
requirements from Combatant Commanders. The majority of large vessel
traffic occurs between the installations and the OPAREAs. The transit
corridor, notionally defined by the great circle route (e.g., shortest
distance) from San Diego to the center of the HRC, as depicted in the
2018 HSTT FEIS/OEIS, is generally used by ships transiting between
SOCAL and HRC. While in transit, ships and aircraft would, at times,
conduct basic and routine unit-level activities such as gunnery,
bombing, and sonar training and maintenance. Of note, support craft
would be more concentrated in the coastal waters in the areas of naval
installations, ports, and ranges. Activities involving vessel movements
occur intermittently and are variable in duration, ranging from a few
hours up to weeks. More information on Navy and non-Navy vessel traffic
patterns in the HSTT Study Area may be found in several studies
prepared by the Navy (Starcovic and Mintz 2021; Mintz, 2016; Mintz and
Filadelfo, 2011; Mintz, 2012; Mintz and Parker, 2006).

Foreign Navies

In addition, we note that in some cases, foreign militaries may
participate in U.S. Navy training or testing activities in the HSTT
Study Area. The Navy does not consider these foreign

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military activities as part of the ``specified activity'' under the
MMPA, and NMFS defers to the applicant to describe the scope of its
request for an authorization.
The participation of foreign navies varies from year to year, but
overall is infrequent compared with Navy's total training and testing
activities. The most significant joint training event is the Rim of the
Pacific (RIMPAC), a multi-national training exercise held every-other-
year primarily in the HRC. The participation level of foreign military
vessels in U.S. Navy-led training or testing events within the HRC and
within SOCAL differs greatly between RIMPAC and non-RIMPAC years. For
example, in 2019 (a non-RIMPAC year), there were 0.1 foreign navy at-
sea days (i.e., 1 day = 24 hours) within HRC and 20 foreign navy at-sea
days within SOCAL (Navy 2021). Out of 56 U.S.-led training events in
2019, 4 involved foreign navy vessels, with an average time per event
of 8.7 hours. In 2020, a RIMPAC year, foreign vessels participating in
U.S. Navy-led events accounted for 32 at-sea days in the HRC from
August through September (some of this activity occurred after the
RIMPAC exercise). During RIMPAC 2022, foreign vessels operated and/or
transited through the HRC for 576 hours (24 days). Even in a RIMPAC
year, the days at sea for foreign militaries engaged in a Navy-led
training or testing activity accounts for a very small percentage
compared to the U.S. Navy activities. For instance, the 2020 foreign
military participation (a RIMPAC-year) was 1.5 percent of the U.S.
Navy's average days at sea (32 days out of an estimated 2,056 days at
sea).
According to the U.S. Navy, consistent with customary international
law, when a foreign military vessel participates in a U.S. Navy
exercise within the U.S. territorial sea (i.e., 0 to 12 nmi (0 to 22.2
km) from shore), the U.S. Navy will request that the foreign vessel
follow the U.S. Navy's mitigation measures for that particular event.
When a foreign military vessel participates in a U.S. Navy exercise
beyond the U.S. territorial sea but within the U.S. Exclusive Economic
Zone, the U.S. Navy will encourage the foreign vessel to follow the
U.S. Navy's mitigation measures for that particular event (Navy 2022a;
Navy 2022b). In either scenario (i.e., both within and beyond the
territorial sea), U.S. Navy personnel will provide the foreign vessels
participating with a description of the mitigation measures to follow.
If a foreign military is not participating in a U.S. Navy training or
testing exercise, foreign military vessels operating within the HSTT
Study Area are expected to adhere to their own standard operating
procedures and environmental mitigation measures.
According to the U.S. Navy, the May 2021 vessel strike of two fin
whales by an Australian navy vessel did not occur while that vessel was
participating in a U.S. Navy-led training exercise. The Royal
Australian Navy vessel was adhering to its standard operating
procedures at the time of the strike. The Royal Australian Navy
provided a report of the incident, which is discussed below to inform
our analysis.
NMFS analyzes the effects of these foreign military activities in
two ways. First, effects of all past foreign military activities are
captured in the baseline for the analysis, through marine mammal
abundance estimates and population trends found in the SARs. Second,
NMFS considers foreign military activities, including recent strikes,
qualitatively in this proposed rule. For instance, in preparing this
rulemaking, NMFS and the U.S. Navy discussed the nature, frequency, and
control over joint or U.S. Navy-led training and testing activities
with foreign entities to identify opportunities to encourage foreign
militaries to adopt mitigation. NMFS and the U.S. Navy examined the
Royal Australian Navy strike report for any lessons that could inform
U.S. Navy strike mitigation. NMFS considered the Royal Australian Navy
strikes along with other recent U.S. Navy strikes to determine whether
these strikes indicate an increased risk of strike by the U.S. Navy in
this region during the early summer months. NMFS also considered the
species struck in this incident, fin whales, along with other
literature, when considering the likelihood of certain species to be
struck by the U.S. Navy. Finally, NMFS considered the fact that two fin
whales were struck by the Royal Australian Navy qualitatively when
considering other fin whale population and mortality trends, as well as
the take proposed for authorization, as part of the negligible impact
analysis.

Standard Operating Procedures

For training and testing to be effective, personnel must be able to
safely use their sensors and weapon systems as they are intended to be
used in a real-world situation and to their optimum capabilities. While
standard operating procedures (SOPs) are designed for the safety of
personnel and equipment and to ensure the success of training and
testing activities, their implementation often yields additional
benefits on environmental, socioeconomic, public health and safety, and
cultural resources. Because standard operating procedures are essential
to safety and mission success, the Navy considers them to be part of
the proposed activities under NEPA and included them in the
environmental analysis. We consider standard operating procedures as
part of Navy's specified activity for the purposes of MMPA but also,
where procedures are utilized (even in part) to reduce impacts to
marine mammal species and Navy's commitment to follow the measures are
practicable, certain SOPs may also be required as mitigation. Details
on standard operating procedures were provided in the 2018 HSTT
proposed rule; please see the 2018 HSTT proposed rule, the 2017 Navy
application, and Chapter 2 (Description of Proposed Action and
Alternatives) of the 2018 HSTT FEIS/OEIS for more information.
As stated in its 2022 application, in 2018, the Navy updated its
SOPs related to vessel safety to incorporate revised procedures
regarding Lookouts for certain ship classes as per the 2021 Surface
Ship Navigation Department Organization and Regulations Manual
(NAVDORM). The 2021 NAVDORM requires the use of three Lookouts on Navy
cruisers and destroyers as compared to the previous requirement of one
Lookout when a vessel was underway and not engaged in sonar training or
testing. However, as discussed in the Proposed Mitigation Measures
section below, the Navy informed NMFS that requiring the additional
Lookouts as mitigation is not practicable because this SOP may change
in response to manning issues and national security needs. Further,
since submission of its 2022 application, the Navy has updated its
Lookout Training Handbook and implemented other training improvements,
as described in the Proposed Mitigation Measures section (September
2022).

Description of Marine Mammals and Their Habitat in the Area of the
Specified Activities

Marine mammal species and their associated stocks that have the
potential to occur in the HSTT Study Area are presented in table 1
along with the best/minimum abundance estimate and associated
coefficient of variation value. Consistent with the 2018 HSTT final
rule and 2020 HSTT final rule, the Navy anticipates the take of
individuals from 38 marine mammal species by Level A harassment and
Level B harassment incidental to training and testing activities from
the use of sonar and other transducers, in-water detonations,

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air guns, and impact pile driving/vibratory extraction activities. As
described in detail later, serious injury or mortality of six species
is also analyzed and proposed for authorization.
In the 2018 HSTT proposed rule and 2018 HSTT final rule, we
presented a detailed discussion of marine mammals and their occurrence
in the HSTT Study Area, inclusive of important marine mammal habitat
(e.g., ESA-designated critical habitat), biologically important areas
(BIAs), national marine sanctuaries (NMSs), and unusual mortality
events (UMEs). Please see these rules and the 2017 and 2019 Navy
applications for additional information beyond what is provided herein.
While there have been some minor changes described here, there have
been no changes to important marine mammal habitat, NMSs, or ESA
designated critical habitat since the issuance of the 2018 HSTT final
rule that change our determination of which species or stocks have the
potential to be affected by the Navy's activities or the information in
the Description of Marine Mammals and Their Habitat in the Area of the
Specified Activities section in the 2019 HSTT proposed rule and 2020
HSTT final rule. Therefore, the information presented in those sections
of the 2019 HSTT proposed rule and 2020 HSTT final rule remains current
and valid with the exception of the information about UMEs, BIAs, and
revised humpback whale stock structures, discussed below.
On April 21, 2021, NMFS designated critical habitat for the
endangered Western North Pacific Distinct Population Segment (DPS), the
endangered Central America DPS, and the threatened Mexico DPS of
humpback whales (86 FR 21082). Areas proposed as critical habitat
include specific marine areas located off the coasts of California,
Oregon, Washington, and Alaska. None of the designated critical habitat
overlaps with the HSTT Study Area. One of the proposed areas, critical
habitat Unit 19, would have overlapped with the SOCAL range in the HSTT
Study Area but was excluded after consideration of potential national
security and economic impacts of designation. NMFS, in the final rule
designating critical habitat for humpback whales, identified prey
species, primarily euphausiids and small pelagic schooling fishes of
sufficient quality, abundance, and accessibility within humpback whale
feeding areas to support feeding and population growth, as an essential
habitat feature. NMFS, through a critical habitat review team (CHRT),
also considered inclusion of migratory corridors and passage features,
as well as sound and the soundscape, as essential habitat features.
NMFS did not include either in the final critical habitat, however, as
the CHRT concluded that the best available science did not allow for
identification of any consistently used migratory corridors or
definition of any physical, essential migratory or passage conditions
for whales transiting between or within habitats of the three DPSs. The
best available science also currently does not enable NMFS to identify
particular sound levels or to describe a certain soundscape feature
that is essential to the conservation of humpback whales. Regardless of
whether critical habitat is designated for a particular area, NMFS has
considered all applicable information regarding marine mammals and
their habitat in the analysis supporting these proposed regulations.
NMFS has reviewed the 2022 final Stock Assessment Reports (SARs;
Carretta et al. 2023, Young et al. 2023). For all species except
humpback whale, NMFS determined that neither the SARs nor any other new
information changes our determination of which species or stocks have
the potential to be affected by the Navy's activities. For humpback
whale, the 2022 final SARs include a revision to the humpback whale
stock structure in the Pacific Ocean. In the 2020 HSTT final rule, NMFS
authorized take of the CA/OR/WA stock and Central North Pacific stock
of humpback whale. Given the revised stock structure, in this proposed
rule, NMFS has reanalyzed the potential for take of each stock of
humpback whale and determined that the Central America/Southern Mexico-
CA/OR/WA, Mainland Mexico--CA/OR/WA stock, and Hawaii stocks are likely
to be taken by the Navy's activities. Please refer to the 2022 Alaska
and Pacific Ocean SARs for additional information about these new
stocks.)
The species considered but not carried forward for analysis are two
American Samoa stocks of spinner dolphins--(1) the Kure and Midway
stock and (2) the Pearl and Hermes stock. There is no potential for
overlap with any stressors from Navy activities and therefore there
would be no incidental takes, in which case, these stocks are not
considered further.

Table 1--Marine Mammal Occurrence Within the HSTT Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
Status Stock abundance
Common name Scientific name Stock ---------------------------------- Occurrence Seasonal (CV)/minimum
MMPA ESA absence population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale.................... Balaenoptera Eastern North Strategic, Endangered Southern -- 1,898 (0.085)/
musculus. Pacific. Depleted California 1,767.
Central North Strategic, Endangered Hawaii Summer 133 (1.09)/63.
Pacific. Depleted.
Bryde's whale................. Balaenoptera Eastern Tropical -- -- Southern -- unknown.
brydei/edeni. Pacific. California
Hawaii........... -- -- Hawaii -- 602 (0.22)/501.
Fin whale..................... Balaenoptera CA/OR/WA......... Strategic, Endangered Southern -- 11,065 (0.405)/
physalus. Depleted California 7,970.
Hawaii........... Strategic, Endangered Hawaii Summer 203 (0.99)/101.
Depleted
Humpback whale................ Megaptera Central America/ Strategic Endangered \1\ Southern Winter 1,496 (0.171)/
novaeangliae. Southern Mexico-- California 1,284.
CA/OR/WA.
Mainland Mexico-- Strategic Threatened\1\ Southern Winter 3,477 (0.101)/
CA/OR/WA. California 3,185.
Hawai[revaps]i... -- --\1\ Hawaii Summer 11,278 (0.56)/
7,265.
Minke whale................... Balaenoptera CA/OR/WA......... -- -- Southern -- 915 (0.792)/509.
acutorostrata. California
Hawaii........... -- -- Hawaii Summer 438 (1.05)/212.
Sei whale..................... Balaenoptera Eastern North Strategic, Endangered Southern -- 519 (0.40)/374.
borealis. Pacific. Depleted California
Hawaii........... Strategic, Endangered Hawaii Summer 391 (0.9)/204.
Depleted

[[Page 68296]]

Gray whale.................... Eschrichtius Eastern North -- -- Southern -- 26,960 (0.05)/
robustus. Pacific. California 25,849.
Western North Strategic, Endangered Southern -- 290 (NA)/271.
Pacific. Depleted California
Sperm whale................... Physeter CA/OR/WA......... Strategic, Endangered Southern -- 1,997 (0.57)/
macrocephalus. Depleted California 1,270.
Hawaii........... Strategic, Endangered Hawaii -- 5,707 (0.23)/
Depleted 4,486.
Pygmy sperm whale............. Kogia breviceps.. CA/OR/WA......... -- -- Southern Winter and 4,111 (1.12)/
California Fall 1,924.
Hawaii........... -- -- Hawaii -- 42,083 (0.64)
25,695.
Dwarf sperm whale............. Kogia sima....... CA/OR/WA......... -- -- Southern -- unknown.
California
Hawaii........... -- -- Hawaii -- unknown.
Baird's beaked whale.......... Berardius bairdii CA/OR/WA......... -- -- Southern -- 1,363 (0.53)/
California 894.
Blainville's beaked whale..... Mesoplodon Hawaii........... -- -- Hawaii -- 1,132 (0.99)/
densirostris. 564.
Cuvier's beaked whale......... Ziphius CA/OR/WA......... -- -- Southern -- 5,454 (0.27)/
cavirostris. California 4,214.
Hawaii........... -- -- Hawaii -- 4,431 0.41/
3,180.
Longman's beaked whale........ Indopacetus Hawaii........... -- -- Hawaii -- 2,550 (0.67)/
pacificus. 1,527.
Mesoplodont beaked whales..... Mesoplodon spp... CA/OR/WA......... -- -- Southern -- 3,044 (0.54)/
California 1,967.
Common Bottlenose dolphin..... Tursiops California -- -- Southern -- 453 (0.06)/346.
truncatus. Coastal. California
CA/OR/WA Offshore -- -- Southern -- 3,477 (0.696)/
California 2,048.
Hawaii Pelagic... -- -- Hawaii -- unknown.
Kauai and Niihau. -- -- Hawaii -- NA NA/97.
Oahu............. -- -- Hawaii -- NA.
4-Islands........ -- -- Hawaii -- NA.
Hawaii Island.... -- -- Hawaii -- unknown.
False killer whale............ Pseudorca Main Hawaiian Strategic, Endangered Hawaii -- 167 (0.14)/149.
crassidens. Islands Insular. Depleted
Hawaii Pelagic... -- -- Hawaii -- 2,086 (0.35)/
1,567.
Northwestern -- -- Hawaii -- 477 (1.71)/178.
Hawaiian Islands.
Fraser's dolphin.............. Lagenodelphis Hawaii........... -- -- Hawaii -- 40,960 (0.7)/
hosei. 24,068.
Killer whale.................. Orcinus orca..... Eastern North -- -- Southern -- 300 (0.1)/276.
Pacific Offshore. California
West Coast -- -- Southern -- 349 (N/A)/349.
Transient. California
Hawaii........... -- -- Hawaii -- 161 (1.06)/78.
Long-beaked common dolphin.... Delphinus California....... -- -- Southern -- 83,379 (0.216)/
capensis. California 69,636.
Melon-headed whale............ Peponocephala Hawaiian Islands. -- -- Hawaii -- 40,647 (0.74)/
electra. 23,301.
Kohala Resident.. -- -- Hawaii -- unknown.
Northern right whale dolphin.. Lissodelphis CA/OR/WA......... -- -- Southern -- 29,285 (0.72)/
borealis. California 17,024.
Pacific white-sided dolphin... Lagenorhynchus CA/OR/WA......... -- -- Southern -- 34,999 (0.222)/
obliquidens. California 29,090.
Pantropical spotted dolphin... Stenella Oahu............. -- -- Hawaii -- unknown.
attenuata.
4-Islands........ -- -- Hawaii -- unknown.
Hawaii Island.... -- -- Hawaii -- unknown.
Hawaii Pelagic... -- -- Hawaii -- 39,768 (0.51)/
25,548.
Pygmy killer whale............ Feresa attenuata. Tropical......... -- -- Southern Winter & unknown.
California Spring
Hawaii........... -- -- Hawaii -- 10,328 (0.75)/
5,885.
Risso's dolphins.............. Grampus griseus.. CA/OR/WA......... -- -- Southern -- 6,336 (0.32)/
Hawaii........... -- -- California -- 4,817.
Hawaii 7,385 (0.22)/
6,150.
Steno bredanensis NSD \2\.......... -- -- Southern -- unknown.
California
Rough-toothed dolphin......... Hawaii........... -- -- Hawaii -- 76,357 (0.41)/
54,804.
Short-beaked common dolphin... Delphinus delphis CA/OR/WA......... -- -- Southern -- 1,056,308 (0.21)/
California 888,971.
Short-finned pilot whale...... Globicephala CA/OR/WA......... -- -- Southern -- 836 (0.79)/466.
macrorhynchus. California
Hawaii........... -- -- Hawaii -- 12,607 (0.18)/
10,847.
Spinner dolphin............... Stenella Hawaii Pelagic... -- -- Hawaii -- unknown.
longirostris.
Hawaii Island.... -- -- Hawaii -- 665 (0.09)/617.
Oahu and 4- -- -- Hawaii -- unknown.
Islands.
Kauai and Niihau. -- -- Hawaii -- unknown.
Kure and Midway.. -- -- Hawaii -- unknown.
Pearl and Hermes. -- -- Hawaii -- unknown.
Striped dolphin............... Stenella CA/OR/WA......... -- -- Southern -- 29,988 (0.3)/
coeruleoalba. California 23,448.

[[Page 68297]]

Hawaii........... -- -- Hawaii -- 35,179 (0.23)/
29,058.
Dall's porpoise............... Phocoenoides CA/OR/WA......... -- -- Southern -- 16,498 (0.61)/
dalli. California 10,286.
Harbor seal................... Phoca vitulina... California....... -- -- Southern -- 30,968 (NA)/
California 27,348.
Hawaiian monk seal............ Neomonachus Hawaii........... Strategic, Endangered Hawaii -- 1,465 \3\ (0.03)/
schauinslandi. Depleted 1,431.
Northern elephant seal........ Mirounga California....... -- -- Southern -- 187,386 (NA)/
angustirostris. California 85,369.
California sea lion........... Zalophus U.S. Stock....... -- -- Southern -- 257,606 (NA)/
californianus. California 233,515.
Guadalupe fur seal............ Arctocephalus Mexico to Strategic, Threatened Southern -- 34,187 (NA)/
townsendi. California. Depleted California 31,019.
Northern fur seal............. Callorhinus California....... Depleted -- Southern -- 14,050 (NA)/
ursinus. California 7,524.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: A ``--'' indicates that this column does not apply.
\1\ The Mainland Mexico-CA-OR-WA stock and the Mexico-North Pacific stock (which does not occur in the HSTT Study Area) of humpback whale comprise the
Mexico DPS. The Hawai[revaps]i stock comprises the Hawai[revaps]i DPS. The Central America/Southern Mexico-CA-OR-WA stock comprises the Central
America DPS.
\2\ NSD--No stock designation. Rough-toothed dolphin has a range known to include the waters off Southern California, but there is no recognized stock
or data available for the U.S. West Coast.
\3\ The best official estimate of the total population size from the NMFS 2022 Stock Assessment Report (Carretta et al. 2023) is 1,465. This estimate is
based on available data through 2020 data for Kure and Midway Atolls, Nihoa Island, and the MHI, and through 2019 for all other subpopulations. More
recent survey data for 2021 and 2022 indicate an increasing trend in population size. NMFS estimates a total population size for 2022 of 1,605 (NOAA
2023).

Unusual Mortality Events

An UME is defined under section 410(6) of the MMPA as a stranding
that is unexpected, involves a significant die-off of any marine mammal
population, and demands immediate response. From 1991 to the present,
there have been 17 formally recognized UMEs affecting marine mammals in
California and Hawaii and involving species under NMFS' jurisdiction.
There is one UME that is applicable to our evaluation of the Navy's
activities in the HSTT Study Area. The gray whale UME along the west
coast of North America is active and involves ongoing investigations.
At the time of publication of the 2020 HSTT final rule, there was an
active UME for Guadalupe fur seal, which NMFS fully considered in its
analysis (85 FR 41780, July 10, 2020). This UME was closed on September
2, 2021, and therefore, it is not discussed further beyond the
information provided here. The UME was closed because conditions under
which the UME was declared are no longer occurring or have become
persistent. Scientists documented a reduction in strandings compared to
peak UME years. The team of scientists who investigated this UME
determined the cause of the UME as being due to malnutrition in
Guadalupe fur seal pups and yearlings from ecological factors (e.g.,
warm water events) in the Pacific Ocean causing suboptimal prey
conditions. Please see https://www.fisheries.noaa.gov/national/marine-life-distress/unusual-mortality-event-2015-2021-guadalupe-fur-seal-and-2015 for additional information on this UME.
Gray Whale UME
Since January 1, 2019, elevated gray whale strandings have occurred
along the west coast of North America, from Mexico to Canada. As of
June 25, 2023, there have been a total of 674 strandings along the
coasts of the U.S., Canada, and Mexico, with 333 of those strandings
occurring along the U.S. coast. Of the strandings on the U.S. coast,
135 have occurred in Alaska, 83 in Washington, 22 in Oregon, and 93 in
California. Full or partial necropsy examinations were conducted on a
subset of the whales. Preliminary findings in several of the whales
have shown evidence of emaciation. These findings are not consistent
across all of the whales examined, so more research is needed. As part
of the UME investigation process, NOAA has assembled an independent
team of scientists to coordinate with the Working Group on Marine
Mammal Unusual Mortality Events to review the data collected, sample
stranded whales, consider possible causal-linkages between the
mortality event and recent ocean and ecosystem perturbations, and
determine the next steps for the investigation. Please refer to:
https://www.fisheries.noaa.gov/national/marine-life-distress/2019-2023-gray-whale-unusual-mortality-event-along-west-coast-and for more
information on this UME. See the Preliminary Analysis and Negligible
Impact Determination section for additional information on how NMFS has
considered this UME in this proposed rule.

Biologically Important Areas

Since publication of the 2020 HSTT final rule, Kratofil et al.
(2023) identified updated BIAs in Hawaii. The HSTT Study Area overlaps
the updated BIAs for small and resident populations of the following
species in Hawaii: spinner dolphin, short-finned pilot whale, rough-
toothed dolphin, pygmy killer whale, pantropical spotted dolphin,
melon-headed whale, false killer whale, dwarf sperm whale, Cuvier's
beaked whale, common bottlenose dolphin, and Blainville's beaked whale.
Further, the HSTT Study Area overlaps updated BIAs for humpback whale
reproduction in Hawaii. The updated BIAs overlap critical Navy training
and testing areas within the HSTT Study Area, including most of the
internal Navy operating areas. Please see Kratofil et al. (2023) for
additional details about the BIAs.

Potential Effects of Specified Activities on Marine Mammals and Their
Habitat

This section provides a discussion of the ways in which components
of the specified activity may impact marine mammals and their habitat.
The Estimated Take section later in this document includes a
quantitative analysis of the number of individuals that are expected to
be taken by this activity. The Negligible Impact Analysis and
Determination section considers the content of this section, the
Estimated Take section, and the Proposed Mitigation section, to draw
conclusions regarding the likely impacts of these activities on the
reproductive success or survivorship of individuals and whether those
impacts are reasonably expected to, or reasonably likely to, adversely
affect the species or stock through effects on annual rates of
recruitment or

[[Page 68298]]

survival. In the Potential Effects of Specified Activities on Marine
Mammals and Their Habitat section of the 2018 HSTT proposed and final
rules, and as updated by the 2020 HSTT final rule, NMFS provided a
description of the ways marine mammals may be affected by the same
activities that the Navy will be conducting during the 7-year period
analyzed in this rulemaking in the form of serious injury or mortality,
physical trauma, sensory impairment (permanent and temporary threshold
shifts and acoustic masking), physiological responses (particularly
stress responses), behavioral disturbance, or habitat effects. We do
not repeat the information here, all of which remains current and
applicable, and instead summarize any new relevant information from the
scientific literature. For more information we refer the reader to
those rules and the 2018 HSTT FEIS/OEIS (Chapter 3, Section 3.7 Marine
Mammals), which NMFS participated in the development of via our
cooperating agency status and adopted to meet our NEPA requirements.
In the Potential Effects of Specified Activities on Marine Mammals
and Their Habitat section of the 2018 HSTT final rule, we stated that
it has been speculated for some time that beaked whales might have
unusual sensitivities to sonar sound due to their likelihood of
stranding in conjunction with mid-frequency active sonar (MFAS) use,
although few definitive causal relationships between MFAS use and
strandings have been documented, and no such findings have been
documented with Navy use in Hawaii and southern California. On March
25, 2022, a beaked whale (species unknown) stranded in Honaunau Bay,
Hawaii. The animal was observed swimming into shore and over rocks.
Bystanders intervened to turn the animal off of the rocks, and it swam
back out of the Bay on its own. Locals reported hearing a siren or
alarm type of sound underwater on the same day, and a Navy vessel was
observed from shore on the following day. The Navy confirmed it used
continuous active sonar (CAS) within 50 km (27 nmi) and 48 hours of the
time of stranding, though the stranding has not been definitively
linked to the Navy's CAS use.
An initial study of another deep diving odontocete, the sperm
whale, found similar behavioral responses and reductions in foraging
when whales were exposed to pulsed active sonar (PAS) and CAS at
similar cumulative Sound Exposure Levels (SELcum), even
though the CAS signal had a lower source level than the PAS signal.
This may indicate that animals were, in this case, responding to the
cumulative energy of a signal rather than the instantaneous amplitude
(Cure et al. 2021, Isojunno et al. 2020). If a beaked whale were
inshore of a Navy vessel using either PAS or CAS MFAS, and responded by
moving away from the vessel, they could find themselves in shallow
water and become disoriented, as may have happened in the case of
Honaunau Bay. In addition, the animal was not seen after it returned to
sea, so blood tissue samples could not be obtained. There has been a
growing body of literature about the impacts of new pathogens on the
health and stranding of marine mammals, including beaked whales in
Hawaii and other locations in the Pacific (e.g., Clifton et al. 2023
and West et al. 2013).

New Pertinent Science Since Publication of the 2020 HSTT Final Rule

NMFS has reviewed new relevant information from the scientific
literature since publication of the 2020 HSTT final rule. Summaries of
the new key scientific literature reviewed since publication of the
2020 HSTT final rule are presented below. The literature generally
falls into the following topic areas: Vessel Strike; Aircraft Noise;
Hearing, Vocalization, and Masking; Hearing Loss (Temporary Threshold
Shift (TTS) and Permanent Threshold Shift (PTS)); Behavioral Reactions;
Stranding; Population Consequences of Disturbance and Cumulative
Stressors; Methodology for Assessing Acoustic Impacts.

Vessel Strike

Crum et al. (2019) analyzed a modeling framework using encounter
theory to estimate the risk of lethal commercial vessel strike to North
Atlantic right whales. Seasonal mortality rates of right whales
decreased by 22 percent on average after a speed rule was implemented,
indicating that the rule is effective at reducing lethal collisions.
The rule's effect on risk was greatest where right whales were abundant
and vessel traffic was heavy but varied considerably across time and
space.
Keen et al. (2019) compared vessel traffic patterns in the Southern
California Bight, San Francisco, and the Pacific Northwest and found
fin whales had a higher risk of nighttime vessel strikes with the
nighttime risk being double daytime risk. The authors concluded that
the shipping lanes contained 14 percent of all traffic volume and
contributed 13 percent of all strike risk similar to conclusions
reached by Rockwood et al. (2017). However, the authors also point out
that a California Current Ecosystem (CCE) wide shipping speed
reductions would not be practicable. Instead, they proposed 24-hour
speed restrictions around and within shipping lanes would be more
effective and feasible than nighttime only speed restrictions
elsewhere. Keen et al. (2019b) reported high fin whale habitat
suitability throughout the Southern California Bight, in particular
inshore in winter and in southern portions of the Bight, which include
HSTT SOCAL Study Area.
Leaper (2019) estimated that a global 10 percent reduction in
shipping speeds could result in a reduction of underwater sound
associated with shipping by approximately 40 percent and vessel strike
risk by around 50 percent by 2050. The vessel strike risk reduction
done by the author is highly variable based solely on the relationship
between ship speed and risk, qualitative in its findings, and
speculative.
Redfern et al. (2019) compared risk of vessel strike to baleen
whales around the Santa Barbara Channel based on 8 years of shipping
data (2008-2015). Species evaluated include blue whales, fin whales,
and humpback whales using available spatial habitat models and
satellite tagging results. Spatial habitat modeling data included the
years 1991, 1993, 1996, 2001, 2005, 2008, and 2009. The authors defined
collision risk based on the co-occurrence of whales and ships for
various management scenarios focused on adding shipping routes,
expanding existing area to be avoided, and reducing shipping speed
associated with these areas. Encounter rate theory was used to predict
relative mortality resulting from vessel strikes by estimating (a) the
encounter rate; (b) the number of encounters that result in a
collision; and (c) the probability that a collision is lethal (Martin
et al. 2016, Rockwood et al. 2017, Crum et al. 2019). The authors
concluded that expanding the existing areas to be avoided and speed
reductions within shipping lanes and their approaches would be the most
effective solutions. Ship speeds declined in the Bight from 2008 to
2015 because California air pollution regulations and economic factors
made slow[hyphen]steaming strategies more favorable, therefore
reduction in risk from slowing ships was greatest in 2008 and lowest in
2015.
Rockwood and Jahncke (2019) estimated that humpback whale mortality
from January to April in Southern California alone was 6.5 whales
(1.63/month), based upon modeling using updated abundance

[[Page 68299]]

estimates for humpback whales off Southern California. When added to
the estimated mortality from July to November, the total estimated
annual humpback mortality from vessel strikes in California alone was
23.4 deaths (16.9 + 6.5). This study did not include information for
January to April for fin or blue whales and did not estimate humpback
mortality in central or Northern California. Thus, even this updated
study may underestimate whale mortality. The author's focus was
exclusively on shipping approaches to San Francisco Bay (Northern
California) and Los Angeles/Long Beach (Southern California) based on
Rockwood et al. 2017 with new local fine scale analysis. The paper
postulated potential mortality from models, not actual reported
strikes. The model is used to predict whale mortality based on factors
listed in Rockwood et al. 2017. In the model results, cargo vessels,
especially container ships, accounted for more than half of the
predicted mortality for all whale species in both Northern and Southern
California with oil tankers accounting for the second highest
mortality. The author's recommendation concludes with commercial
industry-wide shipping speed reduction recommendations given the model
is biased on mortality as a function of speed. In summary, Rockwood and
Jahncke (2019) only addresses commercial shipping strike risk
associated with major California commercial ports, and therefore, the
paper may have limited applicability to how the Navy trains and tests
in SOCAL.
S[egrave]be et al. (2019) assesses previous publications on whale
vessel strike risk methodology and proposed a systematic approach to
addressing the issue called the Formal Safety Assessment: (1)
identification of hazards, (2) assessment of risks, (3) risk control
options, (4) cost-benefit assessment, and (5) recommendations for
decision-making. The authors provided a case study based on data from
Rockwood et al. (2017). No new data analysis is presented in the paper.
Caveats to S[egrave]be et al. (2019) are similar to those mentioned for
Rockwood et al. (2017, 2019): older marine mammal data that may not be
reflective of current or future distribution and focus on limited
navigation within shipping approaches by commercial ships means that
this study may have somewhat limited applicability to how the Navy
trains and tests in SOCAL.
Szesciorka et al. (2019) concluded that while whales have some cues
to avoid ships, this is true only at close range, under certain
oceanographic conditions and if the whale is not otherwise distracted
by feeding, breeding, or other behaviors. The paper is based on a
single blue whale reaction observed in the Santa Barbara Channel, north
of, and outside of, SOCAL. The blue whale was tagged as part of the
U.S. Navy-funded Southern California Behavioral Response Study (SOCAL
BRS) 2010-2015 and exposed to simulated MFAS when a closest point of
approach of 93 m from a passing commercial container ship was noted.
The whale was only tagged for a couple of hours before tag detachment.
As other published papers report from the SOCAL BRS and as cited in the
2018 HSTT FEIS/OEIS, there can be significant individual variation in
response to anthropogenic sources, which in this case would include
vessel transit.
Blondin et al. (2020) estimated blue whale vessel strike risk in
the Southern California Bight by combining predicted daily whale
distributions with continuous vessel movement data for 4 years (2011,
2013, 2015, 2017). The study focuses on the northern Southern
California Bight associated with the commercial vessel traffic
separation zone through Santa Barbara Channel approaching the Port of
Los Angeles/Long Beach. This area is north of and outside of SOCAL. The
authors found that vessel traffic activity across years (2011, 2013,
2015, 2017) was variable and whale spatial probability was also
variable based on inter-annual fluctuations in environmental
conditions. Similar to previous monitoring efforts in Southern
California, blue whales are typically in higher concentrations north of
SOCAL from July-November (Mate et al. 2018), and Blondin et al. (2021)
also picked up on this seasonal variability in their analysis.
Oceanographic conditions favorable for krill development and
concentration (i.e., cool water periods) would lead to increased blue
whale occurrence and higher strike risk as evidenced during the higher
number of blue whale strikes in 2007 (Berman-Kowalewski et al. 2010).
Finally, the coarse level of data analyzed by the authors does not
account for short-term patchy prey conditions influencing blue whale
occurrence and may result in overestimation of average risk.
Redfern et al. (2020) revised their 2019 assessments of vessel
strike risk off California using interannual variability of risk across
multiple years for blue whale, fin whale and humpback whale. The
authors showed higher concentrations of both blue and fin whales along
the Central California coast as compared to within SOCAL. Magnitude of
vessel strike risk was influenced by the ship traffic scenario. In
addition, interannual species variability (1991, 1993, 1996, 2001,
2005, 2008, and 2009) also influenced the magnitude of vessel strike
risk, but did not change whether nearshore or offshore scenarios had
higher risk. The author's conclusions were similar to Redfern et al.
(2019). Figure 2 from Redfern et al. (2020) illustrates mean blue
whale, fin whale, and humpback whale vessel strike risk for California
based on data through 2009. Results from more recent NMFS surveys in
2014 and 2018 may or may not change this assessment in the future.
Rockwood et al. (2020b) calculated expected blue whale and humpback
whale mortality for hypothetical compliance scenarios by imposing speed
caps within and adjacent to vessel traffic lanes leading to the Port of
San Francisco in Central California, 400 miles (643.7 km) north of
SOCAL. Rookwood et al. (2020a) had already demonstrated this area off
Central California had concentrated krill prey with associated higher
distributions of blue whales and humpback whales. Rookwood et al.
(2020b) used better temporal resolution density data than previous
modeling efforts reported by Rookwood et al. (2017). Biological data
analysis for Rookwood et al. (2020b) was based on regional monthly
krill and whale surveys from 2004-2017. Rockwood et al.'s (2020b)
overall modeling conclusions were that lower commercial ship speeds
within the vessel traffic lanes could potentially reduce whale
mortality from vessel strike. The authors acknowledge that local
changes in whale abundance can have strong effects on both inter-annual
and long-term patterns of ship-strike mortality.
Bernknopf et al. (2021) examined the socioeconomic benefits of
using remotely-sensed information instead of in situ observations for
determining blue whale occurrence in the eastern North Pacific Ocean.
Their analysis used blue whale spatial distribution through 1991-2009
projects as representative of 2017 densities (Becker et al. 2012)
combined with automatic identification system (AIS) derived measures of
civilian commercial vessel traffic to predict blue whale vessel strike
risk, called the Reference Case by the authors. The authors then
compared estimated blue whale strike risk in a second analysis that,
instead of using empirically measured blue whale observations converted
into spatial habitat maps, used satellite tracking and environmental
data to identify the spatial and temporal distribution of blue

[[Page 68300]]

whales, called the Counterfactual Case by the authors (Hazen et al.
2017). Estimated mean fatal strikes to blue whales for the Reference
Case based on empirical density data from 1991-2009 ranged from 0.0490
to 2.5877 (max. values >1.000 between June to October) (see Table 2 in
Bernknopf et al. 2021). Estimated mean fatal strikes to blue whales for
the Counterfactual Case based on environmental estimates of blue whale
density in 2017 ranged from 0.0286 to 2.1556 (max. values >1.000
between August to October). An important caveat to this research is
that the two approaches result in different strike risks due to using
different blue whale density estimates.
Barkaszi et al. (2021) designed a model to estimate risks to large
whales from shipping associated with offshore wind development along
the U.S. Atlantic Coast. A key caveat for the model is that it is based
on civilian vessel types associated with wind energy construction
(e.g., tugs, service craft, etc.) with relatively fixed, direct routes
to offshore wind sites. Therefore, while lower vessel speeds can reduce
mortality, prediction and implementation of reduced speed zones are a
far more complex challenge (Barkaszi et al. 2021). Vessel speed has
less effect on strike risk over a fixed distance with fixed target
density when there are no behavioral components considered (Yin et al.
2019). Vessel speed has a significant effect on strike risk only when
behavioral components are considered, thus the ability for the user to
input animal or vessel aversion is an important variable that can
provide insights to the encounter risk based on vessel speeds.
Cusato (2021) discusses the merits of vessel traffic separation
changes or mandatory commercial ship speed reductions in the Santa
Barbara Channel to reduce the risk of vessel strikes to large whales.
The author compares it to similar restrictions on the U.S. East Coast
for North Atlantic right whales. The paper is a policy discussion
rather than an analysis of current biological distribution of large
whales and associated risk. Cusato (2021) focuses on reducing risk from
commercial ships in the current vessel traffic separation scheme within
the Santa Barbara Channel. Speed restrictions in the Channel would need
to be implemented through either Federal regulations or Federal
statute. The author also correctly points out legitimate concerns that
operating large vessels at slow speeds in certain conditions could pose
a safety risk because large vessels are more difficult to control and
steer at slower speeds.
Hausner et al. (2021) examined tradeoffs of blue whale vessel
strikes and speed reduction mitigation over a 17-year period from 2002
to 2018 in the Southern California Bight under two management scenarios
verses a ``fixed strategy'' that implements speed reductions for a
fixed time period each year. The two management strategies were (1) a
``daily strategy'' implementing speed reductions in response to whale
habitat conditions on a daily basis, and (2) a ``seasonal strategy''
implementing speed reductions in response to whale habitat conditions
on a seasonal basis. The period of the author's data analysis also
covers the abnormal marine heat wave along the U.S. West Coast (2014-
2016). The study's focus was exclusively with the traffic separation
lanes leading from the Santa Barbara Channel to the Ports of Los
Angeles and Long Beach, a narrow corridor north of and outside of
SOCAL. The daily and seasonal management strategies were more effective
in reducing blue whale strike risk in the Santa Barbara channel than
the fixed strategy. The daily management strategy had the highest
protective effect. This apparent difference in strategies also applied
during and after the 2014-2016 marine heat wave where the daily
strategy added even extra protection. The authors acknowledged that
interannual variation on blue whale presence in the shipping lanes
added some variability to their analysis. In addition, their study only
considered blue whales sighted within the Traffic Separation Scheme, as
opposed to the broader region where vessels transit through or a blue
whale could occur.
Ransome et al. (2021) documented 40 vessel strikes to large whales
in the Eastern Tropical Pacific Ocean between 1905 and 2017 off the
coasts of 10 Central and South American countries (Mexico to Columbia).
The authors concluded that vessel strikes to large whales are more
prolific in this region than previously reported. For instance, the
author's findings of 40 vessel strikes was over three times greater
than previous reporting and still is likely under reporting total whale
strikes. The majority of whale strikes occurred from the 1950s onward
with the growth of modern shipping and whale watching. Humpback whales
were the most commonly struck species (45 percent) although 30 percent
of the species were not identified in their data.
Rockwood et al. (2021), similar to Rockwood et al. (2020b),
calculated potential whale strike mortalities using AIS vessel data and
whale density data to estimate mortality under several management
scenarios within the commercial shipping lanes passing through Santa
Barbara Channel and San Pedro Channel to and from the Ports of Los
Angeles and Long Beach. While the Santa Barbara Channel is
approximately 100 miles (160.9 km) north of SOCAL, Rockwood et al.'s
study area also included the southern vessel traffic approach to Los
Angeles and Long Beach which did extend into the northeast coastal
portion of SOCAL. Recent whale surveys were not available for this
effort, so the authors used long-term average blue, fin, and humpback
whale densities from Becker et al. (2016). The author's model also
predicted a higher level of whale vessel strikes from commercial ships
than Rockwood et al. (2017), although the authors acknowledged that for
the 2020 publication they included more vessel classes than for the
2017 publication.
Silber et al. (2021) examined the risk to gray whales from
commercial shipping in the North Pacific. Vessel strike risk was
highest for gray whales including the Western North Pacific Distinct
Population Segment (WNP DPS) along most of the migratory routes.
Highest risk to the WNP DPS of gray whales was outside of the SOCAL in
the western Bering Sea, along the east coast of the Kamchatka peninsula
(Russia), and coastlines of Japan. For both Eastern North Pacific and
WNP DPSs of gray whales, the greatest vessel strike risk along the U.S.
West Coast was from Washington to Central California.
Helm et al. (2023) looked at strike risk to foraging humpback
whales surfacing around large cruise ships transiting Glacier Bay
National Park, Alaska. The authors concluded that the probability of
foraging humpback whales remaining near the surface after first
sightings was relatively high. While this puts humpback whales at
increased risk of ship strike, it also allows shipboard observers more
time to spot whales in order to maneuver the ship to avoid a strike.
Lookout Effectiveness
A recent study by Oedekoven and Thomas (2022) was designed to
evaluate the effectiveness of Navy Lookouts at detecting marine mammals
before they entered a defined set of mitigation zones (i.e., 200, 500,
and 1,000 yd (182.9, 457.2, and 914.4 m)) during MFAS training
activities. This study also compared Lookout effectiveness with that of
trained marine mammal observers. Lookout teams were comprised of
varying numbers of Lookouts depending on the type of ship and the
training activity that was occurring (noting that the data was

[[Page 68301]]

collected prior to the Navy's change in its SOPs to require the use of
three Lookouts on Navy cruisers and destroyers.) Marine mammal observer
teams consisted of two dedicated observers. Results of this study
indicate that Navy Lookout Teams, which include Lookouts and other crew
members, have approximately an 80 percent chance of failing to detect a
pod of large baleen whales (rorquals) before they come closer than a
mitigation range of 200 yd (182.9 m), compared with a 49 percent chance
for trained marine mammal observers. The probability of a pod remaining
undetected by Lookouts was greater for larger mitigation zones (i.e.,
85 percent at 500 yd (457.2 m); 91 percent at 1,000 yd (914.4 m)).
These values require some level of interpretation with regard to the
numerical results. For instance, the study's statistical model assumed
that Navy ships moved in a straight line at a set speed for the
duration of the field trials, and that animals could not move in a
direction perpendicular to a ship. Violation of this model assumption
would underestimate Lookout effectiveness for some data points. The
values for both Navy Lookouts and the Marine Mammal Observers include
animals under the water that would not have been available for
detection by a Lookout. This study suggests that detection of marine
mammals is less certain than previously assumed at certain distances.
Hearing, Vocalization, and Masking
Branstetter et al. (2021) measured underwater, masked hearing
thresholds for frequencies between 0.5 and 80 kilohertz (kHz) in two
killer whales. Critical ratios computed from the threshold measurements
ranged from 16 to 32 decibels (dB). For communication signals in the
1.5-15 kHz range, killer whales would require the signal to be up to 26
dB above background Gaussian noise to be detected. The authors noted
that ambient background noise in the marine environment is not
Gaussian, the tones used in this study do not contain as much frequency
information as biologically relevant signals, and the temporal and
spectral characteristics of actual signals and noise may result in some
degree of release from masking. These results are consistent with
critical ratio measurements from other odontocete species, despite
differences in hearing ability and head size.
Fournet et al. (2021) measured call amplitudes from male bearded
seals in the Beaufort Sea under different ambient noise conditions. The
results showed that estimated source levels of seal calls increased
with ambient noise up to approximately 100-105 dB root-mean-squared
(rms), above which no further Lombard effect was observed. This
suggests that masking of bearded seal mating calls may occur, resulting
in reduced communication range, which could reduce the ability of
bearded seals to detect one another, mate, and reproduce.
Mercado (2021) aimed to characterize how units within humpback
whale songs were systematically varied using a large dataset of
recordings from off the coast of Kona, Hawaii. The data showed that
narrowband, reverberant units repeated at regular time intervals and
dominated most song sessions, while broadband units were less
predictable and occupied frequency bands that did not overlap with the
narrowband units. The persistent production of narrowband units at
regular time intervals resulted in consistent reverberation, which
could either function to increase the range at which the song can be
detected, or listen for fluctuations in echoes to indicate the presence
of whale-sized targets.
Rey-Baquero et al. (2021) collected theodolite and passive acoustic
data on humpback whales in a pristine environment along the Colombian
Pacific for 2 months. When acoustic data (n=34 files) were analyzed for
unit duration and inter-unit interval before and after boats passed,
song unit lengths were shorter and more variable when boats were
present. The second aim of this study was to model the whales'
communication space during ambient noise or one to two boats traveling
slowly. The most common peak frequency of this stock's song (350 Hz)
was used in the model, and, along with a whale's location along the
coast, informed calculations of transmission loss. However, the source
level of ``typical whale-watching boats'' (145 dB re 1 uPa (decibels
referenced to 1 micropascal) at 1 m; (Erbe et al. 2012)) and humpback
whales (153 dB re 1 uPa at 1 m; (Au et al. 2006)) were taken from
previous studies. Authors found that the infrequent addition of ecotour
boat noise could temporarily reduce the ``very audible area'' (>10 dB
SNR) in their song's commonly used peak frequency (350 Hz) by 63
percent.
Ruscher et al. (2021) measured aerial behavioral hearing thresholds
in a Hawaiian monk seal (Neomonachus schauinslandi). The results showed
a hearing range between 0.1 and 33 kHz with relatively poor sensitivity
compared to Phocinae seals. The most sensitive thresholds were 40 dB re
20 [mu]Pa measured at 800 Hz and 3.2 kHz. The resulting audiogram was
most similar to the northern elephant seal, which is the only other
species of Monachinae seal with audiogram data (Reichmuth et al. 2013).
This study suggested that hearing sensitivity of Monachinae seals is
substantially reduced compared to other species within their functional
hearing group (phocid carnivores in air; PCA); therefore, the use of
the PCA weighting function to predict auditory impacts is likely
conservative for Hawaiian monk seals.
Sills et al. (2021) measured underwater auditory detection
thresholds in a male Hawaiian monk seal, and the range of most
sensitive hearing was between 0.2 and 33 kHz. Peak hearing sensitivity
of 73 dB re 1 [mu]Pa was observed at 1.6 kHz. The audiogram for this
individual was similar but narrower and elevated compared to the
hearing group (phocid carnivores in water; PCW) composite audiogram
used to assess impacts to this species. Underwater vocalizations were
also measured, and 6 call types were identified, which had peak energy
between 55 and 400 Hz. The number of calls produced per minute
fluctuated seasonally and peaked in the breeding season with the
highest call rates recorded in December.
Sweeney et al. (2022) examined the difference between noise impact
analyses using unweighted broadband sound pressure levels (SPLs) and
analyses using auditory weighting functions. The recordings used to
conduct parallel analyses in three marine mammal species groups were
from a shipping route in Canada. Since shipping noise was predominantly
in the low-frequency spectrum, bowhead whales perceived similar
weighted and unweighted SPLs while narwhals and ringed seals
experienced lower SPLs when auditory weighting functions were used. The
data provide a real-world example to support the use of weighting
functions based on hearing sensitivity when estimating audibility and
potential impact of vessel noise on marine mammals.
A study by von Benda-Beckmann et al. (2021) modeled the effect of
pulsed and continuous 1-2 kHz active sonar on sperm whale echolocation
clicks and found that the presence of upper harmonics in the sonar
signal increased masking of clicks produced in the search phase of
foraging compared to buzz clicks produced during prey capture.
Different levels of sonar caused intermittent to continuous masking
(120 to 160 dB re 1 [mu]Pa2, respectively), but varied based on click
level, whale orientation, and prey target strength. CAS resulted in a
greater percentage of

[[Page 68302]]

time that echolocation clicks were masked compared to PAS.
Kastelein et al. (2021c) compared the ability of harbor porpoises
to detect signals in constant-amplitude noise with amplitude-modulated
noise. Underwater, behavioral hearing thresholds were measured from
harbor porpoises at 4 kHz under three conditions: ambient noise
(control), sinusoidally amplitude modulated (SAM) masking noise, and
Gaussian (constant amplitude) masking noise. Both masker types were
centered at 4 kHz with a one-third octave bandwidth and were tested at
various SPLs. The SAM noise was also tested at modulation rates from 1-
90 hertz (Hz). The 4 kHz hearing test signals were 0.5, 1, and 2
seconds in duration. The results showed that, compared to Gaussian
noise, up to 14.5 dB of masking release (from ``dip listening'') was
observed in lower-modulation rate (1-5 Hz) SAM noise. The effect of
masking on communication space is often modeled using constant-
amplitude noise, whereas most Navy sources contain gaps, more like
amplitude-modulated noise. This study suggests that the signal
duration, masker level, and masker modulation rate and depth should be
considered when modeling the effect of noise on signal detection.
Isojunno et al. (2021) used data from 15 tagged sperm whales
(Isojunno et al. 2020) to evaluate odontocete echolocation behavior as
a function of received sonar exposures. Statistical analysis revealed
small reductions in the number of buzzes and movement during sonar, but
the most apparent change in echolocation behavior was a Lombard effect
observed during higher sea states (increased surface noise). No
behavioral changes in orientation relative to the sonar source were
observed that would suggest an anti-masking strategy for spatial
release from masking. Theoretical modeling of masking potential in
terms of detection range revealed that search phase clicks would likely
be masked during both PAS and CAS, but the buzz clicks would not. For
regular search phase clicks to be continuously masked, SELs would have
to be equal to or greater than 160 and 173 dB re 1 [mu]Pa\2\s (dB
referenced to 1 micropascal squared seconds) for PAS and CAS,
respectively. Overall, the data showed more evidence for masking by
increases in ambient noise (surface noise from higher sea states), than
for sonar. This result could be due, in part, to the 1-2 kHz narrowband
sonar masker, which is not comparable to broadband maskers such as
ambient noise or shipping noise.
Matthews and Parks (2021) reviewed the existing literature on North
Atlantic right whale acoustic behavior and summarize information on
acoustic behavior of the Southern right whale, North Pacific right
whale, and bowhead whale. The authors reviewed primary literature on
whale vocalizations, anatomical modeling, and behavioral responses to
playbacks to conclude that the North Atlantic right whale might have a
hearing range of 20 Hz to 22 kHz. However, vocalization data cannot be
used to directly estimate audible range since there are many examples
of mammals (including marine mammals) that vocalize with energy below
the frequency of best hearing, and calls can also contain high-
frequency harmonics that are above the upper limit of hearing. The
anatomical model developed by Ketten (1994) was used by Parks et al.
(2007) to estimate a functional hearing range of 15 Hz to 18 kHz for
this species.
Jacobson et al. (2022) modeled the probability of Blainville's
beaked whale group vocal periods (GVPs) on the Pacific Missile Range
Facility during periods of no naval activity, naval activity without
hull-mounted MFAS, and naval activity with hull-mounted MFAS. Data were
collected from bottom-mounted hydrophones on the range before, during,
and after six Submarine Commanders Course (SCC) exercises. At an MFAS
received level of 150 dB re 1 [mu]Pa rms (root mean square), the
probability of GVP detection decreased by 77 percent (95 percent CI: 67
percent-84 percent) compared to periods when general training activity
was ongoing and by 87 percent (95 percent CI: 81 percent-91 percent)
compared to baseline conditions. This study found a greater reduction
in p(GVP) with MFAS than observed in a prior study of Blainville's
beaked whales at the Atlantic Undersea Test and Evaluation Center
(AUTEC) (Moretti et al. 2014). The authors suggest that this may be due
to the baseline period in the AUTEC study including naval activity
without MFAS, potentially lowering the baseline p(GVP), or due to
differences in the residency of the populations at each range.
Branstetter and Sills (2022) reviewed direct laboratory (i.e.,
psychoacoustic) studies of marine mammal hearing in noise.
Psychoacoustic studies of auditory masking in marine mammals were
described in detail and categorized by the type of signal and masker
(e.g., tone in white noise), and specific conditions under which
masking is reduced (i.e., release from masking). Specifically,
comodulation masking release, or the reduction in masking due to
amplitude or frequency modulation differences between the signal and
noise, and spatial release from masking, or the reduction in masking
due to spatial separation between signal and noise and the directional
hearing ability of the listener, are discussed. Finally, energetic
masking, or the ability of the listener to detect a signal was compared
to informational masking, or the ability of the listener to comprehend
the signal was reviewed. The authors point out that while the body of
scientific evidence thus far shows that processes of the ear result in
energetic masking, more research on informational masking is needed to
develop realistic communication space models. This is because current
communication space models are based on 50 percent signal detection
rather than some threshold of successful signal recognition or
interpretation by the listener.
Hearing Loss (TTS and PTS)
Houser (2021) reviews existing literature on the relationship
between auditory threshold shift and tissue destruction in mammals.
According to small terrestrial mammal literature, TTSs of approximately
30-50 dB measured 24 hours after sound exposure induced progressive
tissue damage despite the return of normal hearing thresholds. Although
large TTSs allow for full recovery of hearing, pathological tissue
destruction may occur; however, smaller-magnitude TTSs are unlikely to
result in tissue damage. The author concludes that the current criteria
of 40 dB of TTS measured within minutes of the noise exposure as the
onset of injury is likely to encompass recoverable auditory threshold
shift without tissue damage. This publication supports the use of
current definitions of auditory injury in marine mammals.
Kastelein et al. (2022a) measured underwater behavioral hearing
thresholds in two California sea lions at 0.6, 0.85, and 1.2 kHz before
and after exposure to a one-sixth-octave noise band centered at 0.6 kHz
for 60-minutes. Hearing tests were also conducted at 1, 1.4, and 2 kHz
after exposure to a one-sixth-octave noise band centered at 1 kHz for
60-minutes. For the 0.6 kHz exposure, the maximum TTS was 7.5 dB (6.7
dB mean) for a 210 dB cumulative SEL (SELcum) exposure at
the hearing test frequency one-half octave above the center frequency
of the fatiguing stimulus (0.85 kHz), which recovered after
approximately 12 minutes. For the 1 kHz exposure, the maximum TTS was
10.6 dB (9.6 dB mean) after a 195 dB SELcum exposure at the
hearing test frequency one-half octave above the center frequency of
the fatiguing

[[Page 68303]]

stimulus (1.4 kHz). Mean threshold shift (TS) greater than 6 dB (mean =
8.0 dB, min = 7.2 dB, max = 8.5 dB) was also observed after exposure to
the 1 kHz fatiguing stimulus at 195 dB SELcum for the 1 kHz
hearing test frequency. For this exposure frequency, hearing recovered
within 24 minutes. The results of this study show individuals
exhibiting onset of TTS in water at lower received levels than the
otariid thresholds in ``Criteria and Thresholds for U.S. Navy Acoustic
and Explosive Effects Analysis (Phase III)'' (Navy, 2017).
Kastelein et al. (2022b) measured underwater behavioral hearing
thresholds in two California sea lions at 8, 11.3, and 16kHz before and
after exposure to a one-sixth-octave noise band centered at 8 kHz for
60-minutes. Hearing tests were also conducted at 32 kHz after exposure
to a one-sixth-octave noise band centered at 16 kHz for 60-minutes. For
the 8kHz exposure, the maximum TTS was 20.2 dB (18 dB mean) for a 190
dB SELcum exposure at the hearing test frequency one-half
octave above the center frequency of the fatiguing stimulus (11.3 kHz),
which recovered after approximately 12 minutes. For the 16 kHz
exposure, the maximum TTS was 19.7 dB (16.3 dB mean) after a 207 dB
SELcum exposure at the hearing test frequency one-half
octave above the center frequency of the fatiguing stimulus (22.4 kHz).
For these exposure frequencies and scenarios, hearing recovered within
72 minutes or less. The results of this study show TTS onset in-water
occurred at lower received levels than what the current otariid
criteria in ``Criteria and Thresholds for U.S. Navy Acoustic and
Explosive Effects Analysis (Phase III'') (Navy, 2017) suggest.
Kastelein et al. (2021a) measured underwater behavioral hearing
thresholds at 0.5, 0.71, and 1 kHz in one harbor porpoise before and
after exposure to one-sixth-octave band noise centered at 0.5 kHz.
Maximum TTS was 8.9 dB (mean = 7.6 dB) at the 0.5 kHz hearing test
frequency after a 205-dB SELcum exposure. For the 0.71 and 1
kHz hearing test frequencies, no mean TTS > 6 dB was observed. However,
at 0.71 kHz, maximum TTS was 6.5 dB (mean = 5.8 dB) was observed after
a 205-dB SELcum exposure. At 1 kHz, a maximum of 6.3 dB of
TTS (mean = 5.7 dB) occurred after 206-dB SELcum exposures.
All shifts < 5 dB recovered within 12 minutes and shifts > 6 dB
recovered within 60 minutes. These results are consistent with the
criteria and thresholds described in ``Criteria and Thresholds for U.S.
Navy Acoustic and Explosive Effects Analysis (Phase III)'' (Navy,
2017).
Kastelein et al. (2021b) measured behavioral, underwater hearing
thresholds at 2, 2.8, and 4.2 kHz in two sea lions before and after
exposure to band-limited noise centered at 2 kHz. Sea lion hearing was
also tested at 4.2, 5.6, 8 kHz before and after exposure to noise
centered at 4 kHz. Maximum TTS was 24.1 dB (22.4 dB mean) at the 5.6
kHz test frequency after a 205-dB SELcum exposure centered
at 4 kHz. Threshold shifts greater than or equal to 6 dB occurred at
187, 181, and 187 dB SELcum for 4.2, 5.6, and 8 kHz test
frequencies respectively. After exposure to the 2-kHz noise, maximum
TTS of 11.1 dB (10.5 dB mean) occurred for 203 dB SELcum at
the 2 kHz test frequency. Threshold shifts greater than or equal to 6
dB occurred at SELcum of 192, 186, and 198 dB for test
frequencies 2, 2.8, and 4.2 kHz respectively. These data suggest that
one-half octave above the exposure frequency is the most sensitive to
noise exposure. TTS between 6 and 10 dB recovered within 60 minutes,
10-15 dB of TTS recovered within 120 min, and TTS up to 24.1 dB
recovered after 240 minutes. The results of this study show individuals
exhibiting onset of TTS in-water at lower received levels than the
current otariid criteria (``Criteria and Thresholds for U.S. Navy
Acoustic and Explosive Effects Analysis (Phase III)'' (Navy, 2017)).
Kastelein et al. (2020a) measured underwater, behavioral hearing
thresholds in one harbor porpoise before and after exposure to
playbacks of one-sixth-octave band noise centered at 1.5 kHz and a 6.5
kHz continuous wave. Following exposure to the 1.5 kHz noise band at
201 dB SELcum, a maximum of a 7.8 dB, 9.8 dB, and 7 dB TTS
was observed for 1.5, 2.1, and 3 kHz hearing frequencies respectively.
After exposure to the 6.5 kHz continuous wave at 184 dB
SELcum, a maximum of a 7.5, 16.7, and 11.8 dB TTS was
observed for 6.5, 9.2, and 13 kHz hearing frequencies respectively. For
the 6.5 kHz exposure, a mean TTS > 6 dB was observed for the 178 and
180 dB SELcum when the hearing test frequency was 9.2 kHz,
and for the 180 dB SELcum when the hearing test frequency
was 13 kHz. The results of this study show that the animal incurred
onset of TTS at higher received levels than what the current HF
cetacean criteria in ``Criteria and Thresholds for U.S. Navy Acoustic
and Explosive Effects Analysis (Phase III)'' (Navy, 2017) indicate for
both 1.5 and 6.5 kHz.
Kastelein et al. (2020b) measured underwater, behavioral hearing
thresholds in two harbor seals before and after exposure to playbacks
of one-sixth-octave band noise centered at 0.5, 1, and 2 kHz. Hearing
tests were conducted at the center frequency, one-half octave above,
and 1 octave above center frequency. No TTS > 6 dB was observed for any
hearing frequency after 204, 210, or 211 dB SELcum exposures
to the 0.5 kHz noise band. For the 1 kHz exposure frequency, max TTS of
7.4 dB (6.1 mean) was observed after a 207 dB SELcum
exposure at a hearing frequency of 1.4 kHz. For this exposure
frequency, no other test condition produced TTS > 6 dB; although, a 5.9
dB shift (at 1.4 kHz) occurred at 206 dB SELcum. For the 2
kHz noise band, after a 201 dB SELcum exposure, max TTS of
12 dB was measured one octave above the center frequency (4 kHz). For
this exposure frequency, TTS > 6 dB was observed at SELcum >
201, 198, and 192 dB for hearing frequencies 2, 2.8, and 4 kHz
respectively. All shifts recovered within 1 hour. These results of this
study show that the animal incurred lower TTS (i.e., smaller threshold
shifts) at higher received levels than what the current phocid pinniped
criteria in ``Criteria and Thresholds for U.S. Navy Acoustic and
Explosive Effects Analysis (Phase III)'' (Navy, 2017) indicate.
Kastelein et al. (2020c) measured underwater, behavioral hearing
thresholds in one harbor porpoise before and after exposure to
playbacks of one-sixth-octave band noise centered at 88.4 kHz. Maximum
TTS of 13.6 dB was observed at 197 dB SELcum for the 100 kHz
hearing test frequency. No TTS > 6 dB was observed for any
SELcum at the 88.4 kHz test frequency. For 125 kHz, shifts >
6 dB were observed for 191, 194, and 197 dB SELcum
exposures, with a mean TTS of 5.4, 6.1, and 5.9 dB, respectively. The
results of this study show that the animal incurred TTS at higher
received levels than what the current HF cetacean criteria in
``Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects
Analysis (Phase III)'' (Navy, 2017) suggest.
Kastelein et al. (2020d) measured underwater, behavioral hearing
thresholds in one harbor porpoise before and after exposure to airgun
impulses (``shots''). Exposure conditions varied with regard to number
of airguns, number of shots, light cues, and position of the dolphin
relative to the airguns. Hearing test frequencies were 2, 4, and 8 kHz,
and no TTS > 6 dB was observed. The results of this study show that the
animal would incur TTS onset at higher received levels than what the
current HF cetacean criteria in ``Criteria and Thresholds for U.S. Navy
Acoustic and Explosive Effects Analysis (Phase III)'' (Navy, 2017)
suggest.

[[Page 68304]]

Kastelein et al. (2020e) measured underwater, behavioral hearing
thresholds in two harbor seals before and after exposure to playbacks
of one-sixth-octave band noise centered at 40 kHz. For the 50 kHz
hearing test frequency, a maximum TTS of 30.7 dB was observed 12-16
minutes after the 189 dB SELcum, and a mean TTS > 6 dB was
observed for all SELcum 177 dB and above. The 30-dB shift
recovered after 3 days. No TTS > 6 dB was observed for any
SELcum at the 63 kHz test frequency for either seal. At 40
kHz, mean TTS of 9.2 dB was observed after a 189-dB SEL. The results of
this study show that the animal incurred TTS at lower received levels
than what the current phocid criteria in ``Criteria and Thresholds for
U.S. Navy Acoustic and Explosive Effects Analysis (Phase III)'' (Navy,
2017) suggest.
Sills et al. (2020) exposed one bearded seal to multiple impulsive
underwater noise exposures (seismic air gun ``shots''). Hearing tests
were conducted at 100 Hz and 400 Hz after exposures to 2, 4, and 10
shots. After a 4-shot (191 dB SELcum) exposure, max TTS of
9.4 dB was observed, but no other TTS > 6 dB was demonstrated, despite
four 10-shot (194-195 dB SELcum) exposures. It is possible
that TTS recovered during the measurements, as quantified by a mean
``first miss'' of 7.5 dB for the 10-shot exposures (mean TTS was 2.2
dB). The results of this study show that the animal incurred TTS onset
at lower received levels than what the current criteria in ``Criteria
and Thresholds for U.S. Navy Acoustic and Explosive Effects Analysis
(Phase III)'' (Navy, 2017) suggest. Behavioral responses were also
scored and averaged across three observers. For most exposures, the
seal exhibited mild/detectable responses, and all scores indicated that
the seal did not move more than half his body and consistently
participated in the study.
Tougaard et al. (2022) reviewed the most recent temporary TTS data
from phocid seals and harbor porpoises and compared empirical data to
the predictive exposure functions put forth by Southall et al. (2019),
which were based on data collected prior to 2015. The authors concluded
that more recent data supports the thresholds used for harbor porpoises
(categorized as `very high frequency', or VHF cetaceans), which over-
estimated the hearing impact for sounds above 20 kHz in frequency.
Similarly, the new data for phocid seals show TTS onset thresholds that
are well-above the predicted levels for sounds below 5 kHz in
frequency. However, phocid seals might be more sensitive to higher
frequency sound exposures than predicted, as the TTS onset data for
frequencies higher than 20 kHz was below the predicted levels.
von Benda-Beckmann et al. (2022) assessed whether correcting for
kurtosis, a measure of sound impulsiveness, improved the ability to
predict TTS in a marine mammal. Two different kurtosis correction
factors were tested by applying them to frequency-weighted sound
exposure levels (SELcum) and fitting (linear least squares)
previously collected harbor porpoise TTS data to create dose-response
functions, then comparing the resulting R\2\ values to that of the
standard function used to fit TTS growth data. TTS data from both
continuous and intermittent sound exposures were used. For intermittent
and continuous 1-2 kHz exposures combined, kurtosis-corrected fits were
poorer (R\2\ = 0.47, 0.68) than SELcum-based fits (R\2\ =
0.73). For intermittent exposures of different types, one of the
kurtosis-corrections resulted in a better fit (R\2\ = 0.84) than
SELcum (R\2\ = 0.64), but only when a model fitting
parameter denoting the relationship between SELcum and risk
of permanent hearing loss was specifically derived from harbor porpoise
TTS growth data. The conclusions from this study were that the
kurtosis-corrected SELs did not explain differences in TTS between
intermittent and continuous sound exposures, likely because silent
intervals provided an opportunity for hearing recovery that could not
be accounted for by these models. Kurtosis might still be useful for
evaluating sound exposure criteria for different types of sounds having
various degrees of impulsiveness.
Behavioral Reactions
In a study by Benti et al. (2021), vocalizations from Northeast
Atlantic herring-feeding killer whales and Northeast Pacific mammal-
eating killer whales were played back to humpback whales in Norwegian
waters while their behavior was monitored through animal-borne tags and
visual observations. In five of six cases the humpback whales
approached the fish-eating killer whales, suggesting some attraction.
The response to the mammal-eating killer whales varied with the
behavioral context of the humpback whales. The results suggested that
the calls of the fish-eating killer whales may have acted like a
dinner-bell and initiated approach and foraging behavior in the
humpback whales, while the unfamiliar sounds of the mammal-eating
killer whales may have been perceived as a threat in offshore waters,
but led to mixed behavior during inshore herring foraging by humpback
whales. These results indicated that the humpback whales were able to
discriminate between the different call types and respond with
different behavioral strategies.
Boisseau et al. (2021) exposed foraging minke whales in Icelandic
waters to an acoustic deterrent device that emitted 15 kHz pure tones
with a source level of 198 dB rms. Pulse length and the number of
pulses in a block were randomized but average pulse length was 752
millisecond (ms) with a 10 percent duty cycle. The source was deployed
from a Zodiac boat 500 m away from an animal for the first two
exposures, and 1000 m away in the remaining 8 exposures (max received
level of 150 dB RMS at a minimum distance of 338 m). Video-range
tracking was used to track animals before, during, and after the
exposures and dive duration (sec), swim speed (km/h), reoxygenation
rate (blows/min), and path predictability were also examined. During
the exposure, animal speed and dive duration increased, measures of
path predictability increased indicating straighter paths, and
reoxygenation rate decreased. Path predictability had a strong
relationship with received level whereas speed and dive duration did
not, which suggested those two metrics were more influenced by the
presence of the exposure signal than the received sound level.
Cur[eacute] et al. (2021) conducted controlled exposure experiments
using both PAS (5 percent duty cycle) and CAS (95 percent duty cycle)
to measure and score tagged sperm whale behavioral responses. No sonar
control exposures resulted in significantly fewer and less severe
behavioral responses than sonar exposures. No significant differences
were observed between sonar types, but the presence of killer whales or
pilot whales did significantly increase the number of responses. The
probability of observing low and medium severity responses increased
with cumulative sound exposure level (SEL, dB re 1 [mu]Pa2 s), reaching
a probability of 0.5 at approximately 173 dB SEL for low severity
responses. Medium severity responses reached a probability of
approximately 0.35 at cumulative SELs between 179 and 189 dB. This
study suggested that both PAS and CAS exposure resulted in a greater
number of behavioral changes in sperm whales as compared to the vessel
(control) alone, and the types of behavioral responses might differ
across sonar types.
Czapanskiy et al. (2021) modeled energetic costs associated with
behavioral response to MFAS using

[[Page 68305]]

datasets from 11 cetaceans' feeding rates, prey characteristics,
avoidance behavior, and metabolic rates. Authors found that the short-
term energetic cost was influenced more by lost foraging opportunities
than increased locomotor effort during avoidance. Additionally, the
model found that mysticetes incurred more energetic cost than
odontocetes, even during mild behavioral responses to sonar.
Durbach et al. (2021) analyzed acoustic tracks from minke whales
detected on the Pacific Missile Range Facility (PMRF) in Hawaii in 3
years before, during, and after major Navy training exercises. These
tracks were fit using a continuous-time correlated random walk at 5-
minute interpolated locations. During sonar periods, fast movement
became more northerly and more directed (less turning), with less
movement south and east in the direction of the training activity, and
this more northerly movement continued after sonar cessation.
Specifically, whales to the north of the training activity were more
likely to head north, while whales that were west of the activity were
more likely to head west. Headings did not appear to change for slow,
undirected movement during sonar. In addition, fast movement was more
likely to occur during sonar than during any other period (70 percent
during vs 35-41 percent in the other periods). Finally, whales were
more likely to stop calling when in the fast state although not
necessarily more during sonar than in other periods; in contrast, slow
moving whales were more likely to stop calling during sonar than other
periods. These results demonstrated that minke whales moved faster and
movements were more directed during periods of active sonar. Minke
whales also avoided the locations of the ships producing the sonar and
were more likely to cease calling during sonar.
Fernandez-Betelu et al. (2021) used passive acoustic data recorded
over a 10-year time period to assess the effects of impulsive noise
produced during offshore activities on coastal bottlenose dolphin
occurrence. Offshore activities included seismic surveys and pile
driving from wind farm construction. Echolocation detections of
dolphins were compared across years with and without offshore activity
and also across days with and without impulsive noise. The effect of
distance from the noise-producing activities on dolphin detections was
also investigated by placing recorders (CPODs) at locations expected to
be the most (impact areas) and least (reference areas) impacted by
noise. No consistent relationship was found between annual dolphin
occurrence and impulsive noise, but significantly more detections were
observed on days with impulsive noise. The results showed that dolphins
were not displaced by impulsive noise levels up to 141 dB re 1 [mu]Pa
and as close as 20 km (10.8 nmi) from the impact area. These results
suggest that the increase in dolphin detections during far-field noise
was likely due to an increase in the number and/or amplitude of
echolocation vocalizations.
Hastie et al. (2021) studied how the number and severity of
avoidance events may be an outcome of marine mammal cognition and risk
assessment. Five captive grey seals were given the option to forage in
a high- or low-density prey patch while continuously exposed to
silence, pile driving, or tidal turbine playbacks (source levels = 148
dB re 1 [mu]Pa at 1 m) for 1 hour. One prey patch was closer to the
speaker, so had a higher received level in experimental exposures.
Overall, seals avoided both anthropogenic noise playback conditions
with higher received levels when the prey density was limited but would
forage successfully and for as long as control conditions when the prey
density was higher, demonstrating a classic cognitive approach utilized
with predation risk and profit balancing.
In a study by Holt et al. (2021a), DTAGs (miniature sound and
movement recording tags) were attached with suction cups to Southern
Resident Killer Whales in the Salish Sea to investigate the
relationship between probability of prey capture and vessel and sound
variables. The predicted probability of prey capture was lower when
vessels increased their speed. Received noise level did not
significantly affect the probability of prey capture. The rate of
descent during dives was slower when echosounders were on. The observed
effects of echosounders suggest that whales prolonged their foraging
efforts to successfully hunt, which could be caused by acoustic masking
or increased attention to vessels. The rate of descent increased with
increasing broadband noise levels and decreasing vessel distance.
Decrease prey abundance also decreased the probability of predicted
prey capture.
Holt et al. (2021b) attached DTAGs to 23 Southern Resident Killer
Whales in the San Juan Islands over 3 field seasons in order to
investigate the effects of vessel distance on underwater foraging
behavior. When vessels were less than 366 m away, whales (n=13)
decreased the number of dives associated with prey capture and the
amount of time spent in these dives. Additionally, female killer whales
were more likely to stop foraging, socializing, and prey-sharing and
instead start traveling when vessels approached at this distance. At
the same distance from vessels, male orcas were more likely to
transition from close prey capture to socializing and prey-sharing, but
would not stop general foraging behavior, such as searching for prey at
deeper depths. Female orcas may therefore be at greater risk than males
during close vessel interactions.
Kates Varghese et al. (2021) analyzed the effect of two separate
surveys using a 12 kHz multibeam echosounder (i.e., downward directed,
unlike ASW sonar) over the Southern California Antisubmarine Warfare
Range (SOAR) hydrophone array on Cuvier's beaked whale foraging. The
authors conducted a spatial analysis, building off a temporal analysis
of a previously presented dataset (Varghese et al. 2020). There were
differences in spatial use of the SOAR for foraging between the 2
survey years. While no change in overall foraging effort was detected
before, during, and after the surveys each year, some localized spatial
shifts in foraging hot spots were detected during and after the survey
in the second year. Because of the known heterogeneity of prey patches
on SOAR, lack of evidence of avoidance of the sound source, and no
observed change in overall foraging effort, the authors suggest that
the observed spatial shifts were most likely due to prey dynamics.
K[ouml]nigson et al. (2021) tested the efficacy of Banana Pingers
(300 ms, 59-130 kHz frequency modulated, 133-139 dB rms re 1 [micro]Pa
at 1 m source level) as a deterrent for harbor porpoise in Sweden. As
described previously, these pingers were designed to avoid potential
pinniped responses. Authors used recorded echolocation clicks with C-
PODs to measure the presence or absence of porpoise in the area.
Porpoise were less likely to be detected at 0 m and within 100 m of an
active pinger, but a pinger at 400 m appeared to have no effect.
In a study by Laborie et al. (2021), unmanned aerial vehicles
(UAVs) were flown at three altitudes (25, 20, and 15 m) over Weddell
seals, including adult males and females and females with pups. There
was generally little response; 88 percent of the time the animals
showed mild vigilance or no responses, and mothers rarely ended
nursing. Agitation or escape responses only occurred in 12 percent of
observations. The strongest response was in females with pups when wind
speeds were lowest and therefore ambient noise levels were at their
lowest. The probability of response

[[Page 68306]]

increased with lower altitude flights, so at altitudes over 25 m a low
level of impact to Weddell seal behavior would be expected.
Manzano-Roth et al. (2022) found that cross seamount beaked whales
reduced clusters of foraging pulses (Group Vocal Periods) during
Submarine Command Course events and remained low for a minimum of 3
days after the MFA sonar activity.
An analysis subsequent to Varghese et al. (2020) suggested that the
observed spatial shifts of Cuvier's beaked whales during multibeam
echosounder activity on the Southern California Antisubmarine Warfare
Range were most likely due to prey dynamics (Kates Varghese et al.
2021).
Ramesh et al. (2021) explored environmental drivers and the impact
of shipping noise on fin whale vocalizations in Ireland. Approximately
3 months of passive acoustic fin whale call data from spring 2016 used
in the habitat model found that fin whale calls increased at night,
along with signs of higher prey availability. Fin whale calls were also
less likely to be detected for every 1 dB re 1 [mu]Pa/minute increase
in shipping noise levels (rms). However, these results should be used
cautiously since the model was more likely to predict the absence of
fin whale detections, rather than their presence.
Santos-Carvallo et al. (2021) monitored fin whale behavior before,
during, and after the presence of whale watching vessels in Caleta
Cha[ntilde]aral de Aceituno to determine if the whale watching activity
was having any adverse impacts on the fin whales. Whale watching
activities were only conducted by local artisanal fishers; 39 boats
have permission but less than 20 conduct the whale watching activity.
Land-based observations were conducted in January and February of 2015-
2018 via binocular scans and focal follow tracking using a theodolite.
Groups of whales were tracked through the area with continuous sampling
of position, behavior, and presence of boats for every surfacing until
they were no longer visible. Behavior was classified as traveling or
resting, and the groups' swim speed, reorientation, and directness
index, and these were modeled relative to the number of boats and
whether the time period was before, during, or after the boats were
present. Most observations occurred within the presence of at least one
boat, but no more than three boats at one time. Travel swim speeds
increased in the after period, while reorientation increased and
directness decreased during and after the presence of boats. During
rest behavior, reorientation increased during the presence of boats
compared to before the boats were present, and directness decreased
during the presence of boats. These results indicate that when whale
watching vessels were present, the fin whales changed their direction
of movement more frequently, with less linear movement than occurred
before the boats arrived; this behavior may represent evasion or
avoidance of the boats. The increase in travel swim speeds after the
boats left the area may be related to the vessel's rapid speeds when
leaving, sometimes in front of animals, leading to more avoidance
behavior after the boats departed.
Arranz et al. (2021) conducted a noise exposure experiment which
compared behavioral reactions of resting short-finned pilot whale
mother-calf pairs during controlled approaches by a tour boat with two
electric (136-140 dB) or petrol engines (139-150 dB). Approach speed
(<4 kn (7.4 km per hour)), distance of passes (60 m (65.6 yd)), and
vessel features other than engine noise remained the same between the
two experimental conditions. Behavioral data was collected via unmanned
aerial vehicle (UAV) and activity budgets were calculated from
continuous focal follows. Mother pilot whales rested less, and calves
nursed less, in response to both types of boat engines compared to
control conditions (vessel >300 m (328 yd), stationary in neutral).
However, they found no significant impact on whale behaviors when the
boat approached with the quieter electric engine, while resting
behavior decreased 29 percent and nursing decreased 81 percent when the
louder petrol engine was installed in the same vessel.
Hiley et al. (2021) exposed groups of harbor porpoises to ``startle
sounds'', which were 200-ms in duration and were band limited (5.5-20.5
kHz) with a peak frequency of 10.5 kHz and a source level of 176 dB re
1 [micro]Pa. There were 13 exposure sequences in which the startle
sound was repeated for 15 minutes at a 0.6 percent duty cycle, and 11
control sequences in which vessels operated but no startle sounds were
played. Despite a larger distance between porpoise groups and vessels
during sound exposure trials (152 m) as compared to control trials (90
m), avoidance responses during exposures were significant whereas no
avoidance was observed for controls. Porpoises avoided the area where
sound exposures took place for approximately 30-60 minutes, and no
long-term exclusion effect was observed.
Pellegrini et al. (2021) examined how boat presence impacts a
unique subspecies of bottlenose dolphin (Tursiops truncatus gephyreus,
Lahille's bottlenose) that vocalizes while foraging cooperatively with
local fishermen who cast nets onto dolphin-herded fish while standing
in coastal waters in Brazil. Dolphin vocalizations changed in response
to the number, type, and speed of boats within 250 m. When more than
one boat was present, dolphins produced fewer whistles and had a lower
click rate and a longer whistle duration; initial and maximum frequency
increased as well, especially when group size or calf presence
increased. Whistles were longer duration when boat speed increased as
well.
Martin et al. (2022) exposed a wild Cape fur seal breeding colony
in Africa to playback recordings of boat noise and sea-side car
traffic. Focal groups of at least six seals were approached by an
experimenter who crawled within 6 m to avoid disturbing the seals.
Seals were exposed to low (60-64 dB re 20 [micro]Pa rms SPL, broadcast
at 6 m), medium (64-70 dB, broadcast at 3 m), or high (70-80 dB,
broadcast at 1 m) levels, depending on the individual's distance to the
speaker. No behavioral differences were found between low, medium, and
high-level groups. Video recorded behavioral analysis demonstrated that
mother-pup pairs spent less time nursing (15-31 percent) and more time
awake (13-26 percent), vigilant (7-31 percent), and mobile (2-4
percent) during boat noise conditions compared to control conditions.
Mothers were more vigilant (26 percent) than pups (7 percent) to medium
levels of boat noise.
Jones[hyphen]Todd et al. (2021) analyzed the movement of seven
Blainville's beaked whales tagged at (AUTEC) relative to MFAS use
during the SCC training event. Data from these tags was previously
reported by Joyce et al. (2019). A continuous time correlated random
walk movement model accounted for location accuracy by modeling 100
track imputations for each tag and arranged samples in equal time
intervals. The probability of whale presence within the boundary of the
instrumented range (on range), and outside the boundary of the
instrumented range (off range) was modeled relative to the time since
the last MFAS transmission. Results show there was a higher probability
that whales on the range would go off range when there were MFAS
transmissions, and that whales off the range would stay off the range
when there were MFAS transmissions. These results indicate a response
to MFAS that lasted for 3 days since transition rates on-off and off-on
the range returned to baseline levels

[[Page 68307]]

after that amount of time. There was also variability in transition
rates and time spent on/off range between individuals, which highlights
the need to analyze a larger sample size of whales.
Durban et al. (2022) tested new methods of observing behavioral
responses of groups of small delphinids to sonar, where the use of tags
is challenging, and the response of the group is more salient than that
of the individual. They tested the use of a land-based observation
platform coupled with a drone and multiple acoustic recorders to
observe the vocal behavior, group cohesion, group size, and group
behavior before, during, and after a simulated sonar exposure. In a
group of short-beaked common dolphins, the authors found the number of
whistles and sub-groups to increase during the exposure period, but the
directivity of the tracked subgroup did not change much.
K[ouml]nigson et al. (2022) tested the efficacy of Banana Pingers
(300 ms, 59-130 kHz frequency modulated, 133-139 dBrms re 1
[micro]Pa at 1 m source level) as a deterrent for harbor porpoise in
Sweden. As described previously, these pingers were designed to avoid
potential pinniped responses. Authors used recorded echolocation clicks
with C-PODs to measure the presence or absence of porpoise in the area.
Porpoise were less likely to be detected at 0 m and within 100 m of an
active pinger, but a pinger 400 m appeared to have no effect.
Miller et al. (2022) investigated the risk disturbance hypothesis
that an animal's response decision is a trade-off between perceived
risk and the cost of a missed opportunity (the reward of foraging). The
authors predicted that species that are more vulnerable to predation
would be more likely to respond to both predator sounds and
anthropogenic stressors. Using data collected from 2008 to 2017 during
the 3S project in Norway, changes in foraging duration during killer
whale playbacks and changes in foraging duration during mid-frequency
sonar were positively correlated across the four species examined
(listed in order of increasing sensitivity to foraging disruption:
sperm whales, long-finned pilot whales, humpback whales, and northern
bottlenose whales). This suggests that tolerance of predation risk may
play a role in sensitivity to sonar disturbance.
Paitach et al. (2022) tested the efficacy of Banana Pingers (300
ms, 50-120 kHz frequency modulated, 145 dB +/- 3 dB at 1 m source
level) as a deterrent and entanglement mitigation for Franciscana
dolphins in Brazil. These pingers were designed to emit sound outside
of the best hearing range for pinnipeds and were therefore less likely
to incite a ``dinner bell'' effect. Authors used recorded echolocation
clicks with C-PODs to measure the presence or absence of dolphins in
the area. Dolphins were 19 percent and 15 percent less likely to be
detected nearby and within 100 m of an active pinger respectively, but
dolphins 400 m from the pinger did not appear to avoid it. While a
reduction in vocalizations does not always equate to a reduction in
presence, this species has been previously seen departing from areas
with active pingers. Authors did not witness any habituation to the
pinger during the length of the experiment (64 days), and although they
recorded fewer dolphins in the area over time, they believe this was
due to seasonality rather than habitat displacement.
Siegal et al. (2022) used Dtag data from 15 northern bottlenose
whales tagged during 3S efforts off Norway (2013-2016) to estimate body
density (to represent body condition by lipid energy stores) using
hydrodynamic models and obtain foraging and anti-predator indicators
based on vocal behavior and dive metrics. The authors compared relative
anti-predator/foraging indices to body condition and found that
relative anti-predator to foraging indices typically did not depend on
body condition. This finding is inconsistent with the needs/assets
hypothesis; an individual in poor condition would accept more risk
(i.e., engage in less anti-predator behavior) for foraging
opportunities, whereas healthy animals can afford to be more risk
averse (i.e., have a relatively higher anti-predator to foraging index
ratio). The authors suggest that this result may be due to an
insufficient range of body conditions in the data set to determine a
relationship, or a selection of bolder individuals in the tagging
effort. The authors also suggest that animals in good condition may
take greater predation risks because they may successfully flee. Three
of the 15 whales were exposed to sonar (presented in prior 3S
publications). The authors compared foraging and anti-predator metrics
pre- and post-exposure, showing that all three animals increased their
anti-predator index and reduced their foraging index.
Stanistreet et al. (2022) used passive acoustic recordings during a
multinational navy activity to assess marine mammal acoustic presence
and behavioral response to especially long bouts of sonar lasting up to
13 consecutive hours, occurring repeatedly over 8 days (median and
maximum SPL = 120 dB and 164 dB). Cuvier's beaked whales and sperm
whales substantially reduced how often they produced clicks during
sonar, indicating a decrease or cessation in foraging behavior. Few
previous studies have shown sustained changes in foraging or
displacement of sperm whales, but there was an absence of sperm whale
clicks for 6 consecutive days of sonar activity. Sperm whales returned
to baseline levels of clicks within days after the activity, but beaked
whale detection rates remained low even 7 days after the exercise. In
addition, there were no detections from a Mesoplodon beaked whale
species within the area during and at least 7 days after the sonar
activity. Clicks from northern bottlenose whales and Sowerby's beaked
whales were also detected but were not frequent enough at the recording
site used to compare clicks between baseline and sonar conditions.
Benhemma-Le Gall et al. (2021) compared harbor porpoise presence
and foraging activity between periods of baseline and construction at
two Scottish offshore windfarms with arrays of echolocation click
detectors (C-PODs). Noise levels were measured with calibrated noise
recorders, and vessel presence was tracked with AIS data. Authors found
an 8-17 percent decline in porpoise presence compared to baseline, with
more porpoises (more buzzing) further from vessels, construction sites,
and related higher levels of noise. The probability of porpoise
occurrence by source vessels decreased by 9-23 percent without piling
activity, and by 40-54 percent during pile driving. Porpoises were
displaced up to 12 km (6.5 nmi) from pile driving and 4 km (2.2 nmi)
from construction vessels. At an average vessel distance of 2 km (1.1
nmi), porpoise occurrence decreased by up to 35 percent. Outside piling
hours, porpoise detection decreased by 17 percent (0.26), and foraging
(buzzes) decreased by up to 41.5 percent (0.03) with increasing noise
levels (159 and 155 dB re 1 [micro]Pa, respectively). During piling
activities, porpoise occurrence began lower (0.16, 102 dB) but
occurrence still decreased by 9 percent (0.07), and foraging (buzzes,
beginning at 0.76, 104 dB) also decreased by 61.8 percent (0.15) with
increasing noise levels (161 and 155 dB re 1 [micro]Pa, respectively).
Kastelein et al. (2022c) recorded pile driving sounds 100 m from
construction for an offshore windfarm turbine, and six versions of the
sound were created with varying frequency content using low-pass
filters at 44.1, 6.3, 3.2, 1.5, 1.0,

[[Page 68308]]

and 0.5 kHz, at levels of 135 dB re 1 [micro]Pa\2\s. When authors
played these impulsive sounds back to a single harbor porpoise in a
pool, she increased swim speed, respiration rate, distance from the
transducer, and occasionally jumped in response to the sounds with
higher frequencies present (i.e., the sounds with a wider bandwidth,
especially sounds low-pass filtered at 44.1 and 6.3 kHz). However, the
porpoise still moved away from the three most narrowband sounds, just
not as far. Results indicate that frequency weighting of SEL may
improve prediction of harbor porpoise behavioral responses, and authors
present the argument that weighted SELs should be used for reporting
behavioral response threshold levels for criteria.
Todd et al. (2022) detected harbor porpoises with C-PODS before,
during, and after pile driving for an oil and gas platform from 2015-
2020. Pile driving single strike SEL at 750 m was 160-164 dB re 1
[micro]Pa\2\s. Porpoise detections significantly decreased at the
beginning of the construction project, but detections appeared to
return to baseline levels within 5 months. According to the authors,
the lack of significant trend over years indicated that porpoises
returned to the area and did not experience habitat displacement for
the entire 5-year period.

Physiological Responses and Stress

Elmegaard et al. (2021) exposed two captive harbor porpoises to
sonar sweeps (6-9 kHz, 500 msec duration, 50-100 msec rise time,
varying received levels (RL)) and pulsed sounds (50 msec duration, peak
frequency 40 kHz, half power bandwidth of ~5 kHz, rise time < 5 msec,
varying RL) to investigate startle reflex and changes in heart rate.
The sonar exposures did not elicit startle responses; the initial two
to three exposures induced bradycardia (a slow heart rate), with
subsequent habituation. This habituation was conserved after a 3-year
pause in exposures. The authors suggest that the initial bradycardia
allows ``a prolonged breath-hold to assess the nature of a novel
stimuli or flee in crypsis if needed;'' in na[iuml]ve wild cetaceans,
the reduced peripheral perfusion caused by this response may reduce
N2 diffusion from supersaturated tissues during dive
ascents, increasing risk of decompression sickness. Startle responses
to the pulse exposures were directly correlated to RL. The 50 percent
motor-startle probability threshold was around 130 dB re 1 [mu]Pa
(rms50). This is ~85 dB above hearing threshold and is similar to that
observed in bottlenose dolphins (~90 dB over hearing threshold) (Gotz
et al. 2020). No significant change in heart rate was observed. The
authors suggest that the parasympathetic cardiac dive response may
override any transient sympathetic response, or that diving mammals may
not have the cardiac startle response seen in terrestrial mammals in
order to maintain volitional cardiovascular control at depth.
Fahlman et al. (2021) reviews decompression theory and the
mechanisms dolphins have evolved to prevent high N2 levels and gas
emboli (i.e., bends-like symptoms) in normal conditions. However, in
times of high stress, the selective gas exchange hypothesis states that
this mechanism can break down. In addition, circulating microparticles
may be useful biomarkers for decompression stress in cetaceans.
Yang et al. (2021) measured cortisol concentrations in blood
samples of two captive bottlenose dolphins and found significantly
higher levels after exposure to high sound level (140 dB re 1 [mu]Pa)
impulsive noise playbacks, compared to control and low sound levels (0
and 120 dB re 1 [mu]Pa, respectively). Six cytokine gene transcriptions
were also measured in blood samples and two (IL-10 and IFN-[gamma])
showed significant changes at high sound level exposure, compared to
control and low sound levels. Results suggest that repeated exposures
or sustained stress response to impulsive sounds may increase an
affected individual's susceptibility to pathogens, affect growth and
reproduction, etc. In addition, no avoidance behavior was observed
during the trials, indicating that stress-induced physiological changes
could be present despite the absence of behavioral changes.
Williams et al. (2022) measured physiological and behavioral
responses in narwhals in the Arctic during seismic airgun impulse
exposure compared to control conditions. Responses were measured using
heart rate-accelerometer-depth recorders and changes in locomotor,
cardiovascular, and respiratory responses were observed following
exposure. Airgun SELs, as received at 10 m depth during sound source
verifications, were approximately 152 dB re 1 [micro]Pa\2\s at 1 km
(0.5 nmi) range and decreased to approximately 120 dB re 1
[micro]Pa\2\s at 10 km (5.4 nmi) dives. The response to seismic and
vessel noise was a reduction in gliding descents and prolonged periods
of high intensity activity associated with periods of elevated stroke
frequencies. Noise exposure also resulted in periods of prolonged and
intense bradycardia (i.e., slowed heart rate). An increase in post-dive
respiratory rates occurred during recovery from noise-exposed dives
compared to control dives.

Stranding

Danil et al. (2021) document the findings of NOAA's investigation
of the strandings of three coastal bottlenose dolphins in 2015 at
Silver Strand Training Complex in NOAA Technical Memorandum NMFS-SWFSC-
641. On October 21, 2015, two dolphins were found stranded dead near
each other on the beach. Because a Navy major training exercise (MTE)
was underway, these strandings met the criteria of an Uncommon
Stranding Event in accordance with the Southern California Stranding
Response Plan in the Navy's Phase 2 LOA for HSTT. A third decomposed
dolphin was found in the same area 10 days later. Examination of the
dolphins resulted in findings indicative of severe acute trauma,
including lower jaw subcutaneous hemorrhage, emphysema, and cervical
blubber hemorrhage. Additional signs of injury to the cerebrum and
heart, or lipids in the lungs were also discovered. No hemorrhage was
found near the ears. At least two of the dolphins showed signs of
feeding before stranding, and all were in robust condition. There were
no external signs of strike or entanglement. These observations and
lack of others did not clearly determine the cause of the acute trauma.
Based on previous case studies, the investigators determined that
underwater detonation, peracute underwater entrapment (i.e., fisheries
interaction), or sonar were the most plausible causes. The Navy notes
that sonar has not been associated with these kinds of symptoms before,
nor has there ever been any association between dolphin mortality and
sonar. No anti-submarine (ASW) sonar or explosive use was associated
with the Navy MTE; however, unit level training with MF1 sonar occurred
on October 19 (for 35 minutes) and October 20 (62 minutes in total),
with sonar use as close as 6 nmi (11.1 km) to the stranding location.
No known squid or bait fishing efforts within U.S. waters occurred in
the vicinity preceding the strandings. The Navy notes that it is
unknown what fishing efforts occurred in Mexican territorial waters
immediately south of the stranding location.
Wang et al. (2021) conducted an auditory-evoked potential (AEP)
hearing test on a single stranded 19-year-old male melon-headed whale
in the 9.5--181 kHz frequency range. Tone pip trains were presented
underwater at a depth of 0.3 m and 1 m distance from the whale, and
AEPs were recorded by suction cup electrodes on the skin surface.
Hearing was measured in this

[[Page 68309]]

individual after it had been stranded and during attempted
rehabilitation in a concrete pool. Eighteen frequencies were measured
once, and eight frequencies were measured twice, yielding an audiogram
that showed elevated hearing thresholds (compared to the pygmy killer
whale) between 10 and 100 kHz. There are no data from normal-hearing
individuals of the melon-headed whale species to which this study's
data can be compared.

Population Consequences of Disturbance and Cumulative Stressors

Southall et al. (2021) provided updated guidance and methods to
assess the severity of behavioral responses by marine mammals to
several types of anthropogenic noise sources. The criteria developed in
the 2007 effort were updated by explicitly distinguishing between
captive and field studies, decoupling their respective severity scales,
and splitting the severity scale into three categories of foraging,
survival, and reproduction. In addition, the updated guidance changed
the categorization of noise sources and began to consider long term
consequences of exposures rather than just immediate responses.
Additional and consistent metrics to be reported in behavioral response
studies are recommended, including subject-specific metrics (e.g.,
functional hearing group, age class, sex, behavioral state, presence of
calf), exposure context metrics (e.g., exposure type, range to source,
source and animal depth, presence of other species or other noise
sources), and noise exposure metrics (e.g. exposure duration, rise
time, number of exposures, SPL [rms and p-p], SEL, SNR). The authors
then applied the severity scale to acute exposure studies using sonar
sources, continuous (industrial) sources, pile driving sources, and
airgun sources. For the long-term exposure analysis, a set of factors
developed by Bejder and Samuels (2003) were applied to long-term
studies on whale-watching and other long-term exposure or multi-
exposure datasets. These factors included metrics of short-term impacts
and long-term survival measures, characteristics of the studies, and
sources of anthropogenic disturbance. The applied examples of scoring
both acute and long-term studies of behavioral response provide a
framework for other researchers to apply the same metrics to their own
studies.
Migrating humpback whale mother-calf pairs' responses to seismic
surveys were modeled by Dunlop et al. (2021) using both a forwards and
backward approach. While a typical forwards approach can determine if a
stressor would have population-level consequences, authors demonstrated
that working backwards through a population consequences of disturbance
(PCoD) model can be used to assess the ``worst case'' scenario for an
interaction of a target species and stressor. Assumptions for the
extreme scenario were likely exaggerated (e.g., in area for > 48 hours,
exposed to > 3 air gun events) but lack data to inform humpback nursing
behavior and calf survivability during acoustic stressors. The results
demonstrated that migrating whales would not likely experience enough
of a delay as a result of disturbance to result in population
consequences, but whales disturbed in breeding or resting areas would
be more vulnerable to consequences of disturbance.
Greenfield et al. (2020) demonstrated that bottlenose dolphins who
had been injured from boat strike or entanglement experienced a decline
in their social network's preferred associations, and as a result were
more vulnerable to predation and less fecund.
Hin et al. (2021) used a previously published energy budget model
for pilot whales (Hin et al. 2019) to examine how lost foraging days
affect individuals in a population at carrying capacity. In this model,
depletion of prey is dependent on whale density, and prey density
limits the energy available for growth, reproduction, and survival. The
authors assumed extreme disturbance events for this study: consecutive
days of no foraging affecting all individuals in a population. The
undisturbed whale population was regulated through the effect of prey
availability on calf survival and pregnancy rates and on age at first
reproduction of females. During a disturbance event, population decline
was generally attributed to loss of lactating females and calves due to
reduced body condition. The subsequent increase in prey density and per
capita prey availability, however, resulted in improved body condition
in the population overall and decreased age at first calf. As
disturbance duration was increased (~40 days of no foraging), the
population would enter extreme decline towards extinction.
Murray et al. (2021) conducted a cumulative effects assessment on
Northern and Southern Resident killer whales, which involved both a
Pathways of Effects conceptual model and a Population Viability
Analysis quantitative simulation model. Authors found that both
populations were highly sensitive to prey abundance and were also
impacted by the interaction of low prey abundance with vessel strike,
vessel noise, and polychlorinated biphenyls contaminants. However, more
research is needed to validate the mechanisms of vessel disturbance and
environmental contaminants.
Pirotta et al. (2020) reformulated their previous dynamic energy
budget model (Pirotta et al. 2018) to investigate the state-dependent
life history strategies of female long-finned pilot whales and trade-
offs between their body condition (i.e., ability to offset starvation
during pregnancy and provide milk), prey availability, and decision to
reproduce in situations with and without disturbance. Many whales in
this model attempted to reproduce young, and while that had no cost in
situations without disturbance, young mothers would starve and die when
foraging was prevented by some disturbance event or because resources
were low (winter). Whale reproductive strategies resulted in lower
lifetime reproductive output, compared to the model used in Hin et al.
(2019).
Pirotta et al. (2021) integrated different sources of data (e.g.,
controlled exposure data, activity monitoring, telemetry tracking, and
prey sampling) into a bioenergetic model, which was used to predict
effects from sonar on a blue whale's daily energy intake. Approximately
half of the simulated whales had no change in daily net energy intake
because they either had no response or were not exposed. However, the
other half experienced a decrease in net energy intake. A portion (11
percent) of those simulated whales had negative net energy even after
brief (e.g., 6-30 min) or weak (e.g., 160-180 dB re 1 [mu]Pa source
level) events, which indicated that they would not be able to cover
that day's energetic cost. This dichotomy in results was due to the
variation in activity budgets, lunging rates and ranging patterns
between tagged whales. This evidence suggests that context can
influence the predicted costs of disturbance even more than body size
or prey density distribution on a daily scale (although prey
availability and abundance affected behavioral patterns).
Pirotta et al. (2022) evaluated potential long-term effects of
changing environmental conditions and military sonar by modeling vital
rates of Eastern North Pacific blue whales. Previous work from Pirotta
et al. (2021) was used as a foundation for incorporating the most
recent best available science into the vital rate model presented in
this study. Using data and underlying models of behavioral patterns,
energy budgets, body condition, contextual responses to noise, and prey
resources, the model predicted female vital rates

[[Page 68310]]

including survival (age at death), and reproductive success (number of
female calves). The model simulation results showed that
``[e]nvironmental changes were predicted to severely affect vital
rates, while the current regime of sonar activities was not.'' The case
study used an annual sonar regime in SOCAL based on the description of
the action in the Navy's 2018 HSTT FEIS/OEIS. Additional military sonar
scenarios were modeled, and a ten-fold increase in sonar activity
combined with a shift in geographical location to overlap with main
feeding areas of blue whales resulted in a moderate decrease in
lifetime reproductive success (Cohen's d = 0.47). However, there was no
effect on survival (Cohen's d = 0.05).
Pirotta (2022) covered the development of bioenergetic models
[``any mechanistic model where the principles of metabolic ecology are
used to describe how an individual animal acquires energy from food
resources (i.e., energy intake) and allocates assimilated energy to
various life history functions (i.e., energy costs, including
maintenance and survival, growth and reproduction)''] with a focus on
applications to marine mammals. This article provided a thorough
overview of the history of marine mammal bioenergetic models, defined
relevant terminology, and explained the differences between general
types of models.
McHuron et al. (2021) developed a state-dependent behavioral and
life history model to predict the probability of Western gray whale
mother-calf pair survival with and without acoustic disturbance and
with or without adequate prey availability on their summer foraging
grounds. Pregnant mother movement, feeding behavior, fat mass and fetal
length were input data for the model. Since prey availability was co-
dependent on whales having access to high-density offshore areas by
mid-July, nearshore seismic surveys had no impact on population
fecundity or mother-calf survival. This model overcomes a key challenge
in PCoD literature by providing a link between behavioral responses and
vital rates; authors recommend focusing on species that are data rich
to accurately characterize the biology of the focal species, metrics of
fitness, and key qualities of their environment.
Joy et al. (2022) presented a hypothetical case study for fin
whales off Southern California exposed to stationary single-ship 53C
sonar events over the course of a year, using the Navy's Phase 3
behavioral response function (BRF). Two model runs were compared: using
[alpha] = 0.05 (average 20-minute movement disruption) and [alpha]=
0.99 (average 3 days movement disruption). When animals returned to
baseline behavior after a short disturbance ([alpha] = 0.05), there was
less regional displacement and thus more instances of behavioral
disturbance over the course of a year. When animals returned to
baseline behavior after a longer period ([alpha]=0.99), there were
fewer instances of behavioral disturbances over the course of a year
due to cumulative displacement from habitat near the sonar source.
Keen et al. (2021) reviewed 15+ years of PCoD modeling and
identified the most critical factors for determining long-term impacts
to populations. Critical factors include life-history traits,
disturbance source characteristics, and environmental conditions. No
specific model or quantitative assessment was proposed.
Methodology for Assessing Acoustic Impacts
Palmer et al. (2022) recorded North Atlantic right whale upcalls
using 10 Marine Autonomous Recording Units deployed in Cape Cod Bay
from February to May 2009. A modified equation was provided for
determining the effective survey area, including a Lombard coefficient,
for single sensor applications. The authors state manual annotation or
verification is nearly always used to confirm automated detector
outputs prior to near-real-time conservation measures due to
limitations in automatic detector capabilities.
Aircraft Noise
Kuehne et al. (2020) measured in-air and underwater sound from low-
altitude EA-18G Growler flights in the immediate vicinity of Ault Field
at Naval Air Station Whidbey Island (NASWI). Data were collected by two
in-air recorders and one hydrophone placed just off the runway at a
depth of 30 meters. The underwater 10-flight average sound measurement
was 134 3 dB re 1 [mu]Pa rms in the highest 1-second
window. The results showed that the peak frequency range of the Growler
overflight noise both in air and underwater was between 50 and 1,000
Hz, which is typically a frequency range with high background noise
underwater, particularly in areas with large amounts of vessel traffic
(Erbe et al. 2012). The study did not include behavioral observations
of wildlife, and the authors' conclusions about potential impacts to
wildlife were unsupported by data from the study. In a separate effort,
Kuehne and Olden (2020) relied on volunteers to identify military
aircraft noise in recordings taken on land on the Olympic Peninsula.
This study also did not examine impacts to or responses by wildlife to
aircraft.
We reiterate that NMFS reviewed the Navy's analysis and conclusions
that aircraft noise will not result in incidental take of marine
mammals, and finds the analysis and conclusions complete and
supportable, as stated in the 2018 HSTT final rule. Please see section
3.7 (Marine Mammals) of the 2018 HSTT FEIS/OEIS for additional
information.
Conclusion for New Pertinent Science Since Publication of the 2020 HSTT
Final Rule
Having considered the best scientific information available,
specifically new relevant information published since the 2020 HSTT
final rule, we have preliminarily determined that there is no new
information that substantively affects our analysis of impacts on
marine mammals and their habitat that appeared in the 2020 HSTT final
rule, all of which remains applicable and valid for our assessment of
the effects of the Navy's activities during the 7-year period of this
rulemaking.

Estimated Take of Marine Mammals

This section indicates the number of takes that NMFS is proposing
for authorization, which are based on the amount of take that NMFS
anticipates could occur or is likely to occur, depending on the type of
take and the methods used to estimate it, as described below. NMFS
coordinated closely with the Navy in the development of their
incidental take application and preliminarily agrees that the methods
the Navy has put forth described herein, in the 2019 HSTT proposed
rule, 2020 HSTT final rule, and in the 2018 HSTT proposed and final
rules to estimate take (including the model, thresholds, and density
estimates), and the resulting numbers are based on the best available
science and appropriate for authorization, with the exception of that
of humpback whales, discussed further below. The number and type of
incidental takes that could occur or are likely to occur annually
remain identical to those authorized in the 2018 HSTT regulations and
2020 HSTT regulations, with the exception of proposed takes by serious
injury or mortality by vessel strike and harassment takes of humpback
whale stocks in Southern California (due to the new stock structure).
Takes are predominantly in the form of harassment, but a small
number of serious injuries or mortalities could

[[Page 68311]]

occur. For military readiness activities, the MMPA defines
``harassment'' as (i) any act that injures or has the significant
potential to injure a marine mammal or marine mammal stock in the wild
(Level A harassment); or (ii) any act that disturbs or is likely to
disturb a marine mammal or marine mammal stock in the wild by causing
disruption of natural behavioral patterns, including, but not limited
to, migration, surfacing, nursing, breeding, feeding, or sheltering, to
a point where such behavioral patterns are abandoned or significantly
altered (Level B harassment).
Proposed authorized takes would primarily be in the form of Level B
harassment, as use of the acoustic and explosive sources (i.e., sonar,
air guns, pile driving, explosives) and is more likely to result in the
disruption of natural behavior patterns to a point where they are
abandoned or significantly altered (as defined specifically at the
beginning of this section but referred to generally as behavioral
disturbance) or TTS for marine mammals. There is also the potential for
Level A harassment in the form of auditory injury and/or tissue damage
(the latter from explosives only) to result from exposure to the sound
sources utilized in training and testing activities. Additionally,
serious injuries or mortalities of mysticetes (except for sei whales,
minke whales, Bryde's whales, Central North Pacific stock of blue
whales, Hawaii stock of fin whales, Western North Pacific stock of gray
whales, and sperm whales) could occur through vessel strike. Proposed
mitigation and monitoring measures are expected to minimize the
severity of the taking to the extent practicable.
Generally speaking, for acoustic impacts, NMFS estimates the amount
and type of harassment by considering: (1) acoustic thresholds above
which NMFS believes the best available science indicates marine mammals
would experience behavioral disturbance or incur some degree of
temporary or permanent hearing impairment; (2) the area or volume of
water that will be ensonified above these levels in a day or event; (3)
the density or occurrence of marine mammals within these ensonified
areas; and (4) and the number of days of activities or events.
Acoustic Thresholds
Using the best available science, NMFS, in coordination with the
Navy, has established acoustic thresholds that identify the most
appropriate received level of underwater sound above which marine
mammals exposed to these sound sources could be reasonably expected to
experience a disruption in behavior patterns to a point where they are
abandoned or significantly altered or to incur TTS (equated to Level B
harassment) or permanent threshold shift (PTS) of some degree (equated
to Level A harassment). Thresholds have also been developed to identify
the pressure levels above which animals may incur non-auditory injury
from exposure to pressure waves from explosive detonation.
We described the acoustic thresholds and the methods used to
determine thresholds, none of which have changed, in detail in the
Acoustic Thresholds section of the 2018 HSTT final rule; please see the
2018 HSTT final rule for detailed information. Further, in the 2020
HSTT final rule, we described new relevant information from the
scientific literature since publication of the 2018 HSTT final rule.
Since publication of the 2020 HSTT final rule, a number of additional
studies have published, including several associated with TTS in harbor
porpoises and seals (e.g., Kastelein et al. 2020d; Kastelein et al.
2021a and 2021b; Sills et al. 2020). NMFS is aware of these recent
papers, summarized above in the New Pertinent Science Since Publication
of the 2020 HSTT Final Rule section. NMFS is currently working with the
Navy to update NMFS' Technical Guidance for Assessing the Effects of
Anthropogenic Sound on Marine Mammal Hearing Version 2.0 (Acoustic
Technical Guidance; NMFS 2018) to reflect relevant papers that have
been published since the 2018 update on our 3-5 year update schedule in
the Acoustic Technical Guidance. First, we note that the recent peer-
reviewed updated marine mammal noise exposure criteria by Southall et
al. (2019) provide identical PTS and TTS thresholds and weighting
functions to those provided in NMFS' Acoustic Technical Guidance.
NMFS will continue to review and evaluate new relevant data as it
becomes available and consider the impacts of those studies on the
Acoustic Technical Guidance to determine what revisions or updates may
be appropriate. However, any such revisions must undergo peer and
public review before being adopted, as described in the Acoustic
Technical Guidance methodology. While some of the relevant data may
potentially suggest changes to TTS/PTS thresholds for some species, any
such changes would not be expected to change the predicted take
estimates in a manner that would change the necessary determinations
supporting the issuance of these regulations, and the data and values
used in this proposed rule reflect the best available science.

Navy's Acoustic Effects Model

The Navy proposes no changes to the Acoustic Effects Model as
described in the 2018 HSTT final rule (and incorporated by reference in
the 2020 HSTT final rule), and there is no new information that would
affect the applicability or validity of the model. Please see the 2018
HSTT final and proposed rules and Appendix E of the 2018 HSTT FEIS/OEIS
for detailed information.

Range to Effects

The Navy proposes no changes from the 2018 HSTT final rule (and
subsequent 2020 HSTT final rule) to the type and nature of the
specified activities to be conducted during the 7-year period analyzed
in this proposed rule, including equipment and sources used and
exercises conducted. NMFS has reviewed and will continue to review and
evaluate new relevant data as it becomes available and consider the
impacts of those studies on the Acoustic Technical Guidance to
determine what revisions/updates may be appropriate. However, any such
revisions must undergo peer and public review before being adopted, as
described in the Acoustic Guidance methodology. While some of the
relevant data may potentially suggest changes to TTS/PTS thresholds for
some species (e.g., Kastelein et al. (2020a) shows onset of TTS
incurred by a harbor porpoise at higher received levels than would have
been anticipated based on the existing criteria, while Kastelein et al.
(2022a) shows onset of TTS in otariids in water at lower received
levels than the existing criteria), our assessment suggests that any
such changes would not be expected to change the predicted take
estimates in a manner that would change the necessary determinations
supporting the issuance of these regulations, and the data and values
used in the 2018 HSTT final rule, 2020 HSTT final rule, and this
proposed rule reflect the best available science. Therefore, the ranges
to effects in this proposed rule are identical to those described and
analyzed in the 2018 HSTT final rule and 2020 HSTT final rule,
including received sound levels that may cause onset of significant
behavioral response and TTS and PTS in hearing for each source type or
explosives that may cause non-auditory injury. Please see the Range to
Effects section and tables 24 through 40 of the 2018 HSTT final rule
for detailed information.

[[Page 68312]]

Marine Mammal Density

The Navy proposes no changes to the methods used to estimate marine
mammal density described in the 2018 HSTT final rule, and there is no
new information that would affect the applicability or validity of
these methods or change the results in a manner that would change the
necessary determinations supporting the issuance of these regulations.
The Navy's estimate of marine mammal density as described in the 2018
HSTT final rule remains valid, though, as described herein, NMFS has
incorporated new information regarding humpback whale stock structure
into its analysis. Please see the 2018 HSTT final rule, and below, for
detailed information.
As noted above, NMFS regularly updates SARs, and in this rulemaking
considers the 2022 final SARs (Carretta et al. 2023, Young et al.
2023). While these SARs contain updated information, the Navy's
estimate of marine mammal density as described in the 2018 HSTT final
rule remains valid for the following reasons. The Navy uses its Marine
Species Density Database (NMSDD) for its analysis, which is derived
from multiple sources, including but not limited to SARs. In contrast,
for most cetacean species, the SAR is estimated using line-transect
surveys or mark-recapture studies (e.g., Barlow, 2010; Barlow and
Forney, 2007; Calambokidis et al. 2008). The result provides one single
abundance value for each species across broad geographic areas, but it
does not provide information on the species density or concentrations
within that area, and it does not estimate density for other timeframes
or seasons that were not surveyed. A change in a stock's abundance
indicated in a SAR does not necessarily indicate a change in that
stock's density in any given area. Therefore, stocks in the HSTT Study
Area with higher abundance estimates in the most recent SARs in
comparison to the abundance estimates at the time that marine mammal
densities were derived for the HSTT Study Area do not necessarily now
occur in higher densities in the HSTT Study Area. For humpback whale,
while the stock structure in the Pacific Ocean was revised in the 2022
final SARs, the discussion above remains true regarding density of
humpback whales in the HSTT Study Area across all stocks.

Take Requests

As in the 2018 HSTT final rule and 2020 HSTT final rule, the Navy
determined that the three stressors below could result in the
incidental taking of marine mammals. NMFS has reviewed the Navy's data
and analysis and determined that it is complete and accurate, and NMFS
agrees that the following stressors have the potential to result in
takes of marine mammals from the Navy's planned activities:
Acoustics (sonar and other transducers; air guns; pile
driving/extraction);
Explosives (explosive shock wave and sound, assumed to
encompass the risk due to fragmentation); and
Physical Disturbance and Strike (vessel strike).
NMFS reviewed and agrees with the Navy's conclusion that acoustic
and explosive sources have the potential to result in incidental takes
of marine mammals by harassment, serious injury, or mortality. NMFS
carefully reviewed the Navy's analysis and conducted its own analysis
of vessel strikes, determining that the likelihood of any particular
species of large whale being struck is quite low. However, as noted
previously, in 2021, two separate U.S. Navy vessels struck unidentified
large whales on two separate occasions, one whale in June 2021 and one
whale in July 2021. In May 2023, the U.S. Navy struck a large whale,
which based on available photos and video, NMFS and the Navy have
determined was either a fin whale or sei whale. NMFS agrees that vessel
strikes have the potential to result in incidental take from serious
injury or mortality for certain species of large whales, and the Navy
has specifically requested coverage for these species. Therefore, the
likelihood of vessel strikes, and later the effects of the incidental
take that is being proposed to be authorized, has been fully analyzed
and is described below.
Regarding the quantification of expected takes from acoustic and
explosive sources (by Level A and Level B harassment, as well as
mortality resulting from exposure to explosives), the number of takes
are based directly on the level of activities (days, hours, counts,
etc., of different activities and events) in a given year. In the 2020
HSTT final rule, take estimates across the 7 years were based on the
Navy conducting 4 years of a representative level of activity and 3
years of maximum level of activity. As in the 2020 HSTT final rule, the
Navy proposes to use the maximum annual level to calculate annual takes
(which would remain identical to what was determined in the 2020 HSTT
final rule, with the exception of attribution of takes to humpback
whale stocks), and the sum of all years (4 representative and 3
maximum) to calculate the 7-year totals for this rulemaking.
The quantitative analysis process used for the 2018 HSTT FEIS/OEIS
and the 2017 and 2019 Navy applications to estimate potential exposures
to marine mammals resulting from acoustic and explosive stressors is
detailed in the technical report titled Quantifying Acoustic Impacts on
Marine Mammals and Sea Turtles: Methods and Analytical Approach for
Phase III Training and Testing (U.S. Department of the Navy, 2018). The
Navy Acoustic Effects Model estimates acoustic and explosive effects
without taking mitigation into account; therefore, the model
overestimates predicted impacts on marine mammals within mitigation
zones. To account for mitigation for marine species in the take
estimates, the Navy conducts a quantitative assessment of mitigation.
The Navy conservatively quantifies the manner in which procedural
mitigation is expected to reduce the risk for model-estimated PTS for
exposures to sonars and for model-estimated mortality for exposures to
explosives, based on species sightability, observation area,
visibility, and the ability to exercise positive control over the sound
source. Where the analysis indicates mitigation would effectively
reduce risk, the model-estimated PTS are considered reduced to TTS and
the model-estimated mortalities are considered reduced to injury. For a
complete explanation of the process for assessing the effects of
mitigation, see the 2017 Navy application and the Take Requests section
of the 2018 HSTT final rule. The extent to which the mitigation areas
reduce impacts on the affected species and stocks is addressed
separately in the Preliminary Analysis and Negligible Impact
Determination section.
No changes have been made to the quantitative analysis process to
estimate potential exposures to marine mammals resulting from acoustic
and explosive stressors and calculate take estimates, with the
exception of take of humpback whales to account for the change in stock
structure. Please see the documents described in the paragraph above,
the 2018 HSTT proposed rule, the 2018 HSTT final rule, and below for
detailed descriptions of these analyses. While Oedekoven and Thomas
(2022) suggest that detection of marine mammals is less certain than
previously assumed at certain distances, NMFS has independently
evaluated the Navy's method for application of mitigation effectiveness
in estimating take and agrees that it is appropriately applied to
augment the model in the prediction and authorization of injury and

[[Page 68313]]

mortality as described in the rule, including after consideration of
Oedekoven and Thomas (2022). In summary, we believe the Navy's methods,
including the method for incorporating mitigation and avoidance, are
the most appropriate methods for predicting PTS, TTS, and behavioral
disturbance. But even with the consideration of mitigation and
avoidance, given some of the more conservative components of the
methodology (e.g., the thresholds do not consider ear recovery between
pulses), we would describe the application of these methods as
identifying the maximum number of instances in which marine mammals
would be reasonably expected to be taken through PTS, TTS, or
behavioral disturbance.

Summary of Requested Take From Training and Testing Activities

Based on the methods discussed in the previous sections and the
Navy's model and quantitative assessment of mitigation, the Navy
provided its take estimate and request for authorization of takes
incidental to the use of acoustic and explosive sources for training
and testing activities both annually (based on the maximum number of
activities that could occur per 12-month period) and over the 7-year
period in its 2019 rulemaking/LOA application. With the exception of
changes to humpback whale take, described below, annual takes (based on
the maximum number of activities that could occur per 12-month period)
from the use of acoustic and explosive sources are identical to those
presented in tables 41 and 42 and in the Explosives subsection of the
Take Requests section of the 2018 HSTT final rule. The 2022 Navy
application includes the Navy's updated take estimate and request for
take by vessel strike due to vessel movement in the HSTT Study Area.
NMFS reviewed the Navy's data, methodology, and analysis and determined
that it was complete, but NMFS has reanalyzed the potential for vessel
strike following the May 2023 strike, as described in the Estimated
Take from Vessel Strikes and Explosives by Serious Injury or Mortality
section. NMFS agrees that the estimates for incidental takes by
harassment from all sources as well as the incidental takes by serious
injury or mortality from explosives requested for authorization are the
maximum number of instances in which marine mammals are reasonably
expected to be taken at the time of Navy's request, and continues to be
for all stocks other than humpback whales, for which changes are
described below. NMFS also agrees that the takes by serious injury or
mortality as a result of vessel strikes could occur. Note that,
consistent with the 2020 HSTT final rule, the total amount of estimated
incidental take from acoustic and explosive sources over the total 7-
year period covered by the 2019 Navy application is less than the
annual total multiplied by seven. Although the annual estimates are
based on the maximum number of activities per year and therefore, the
maximum possible estimated takes, the 7-year total take estimates are
based on the sum of 3 maximum years and 4 representative years, with
the exception of humpback whale stocks that occur in SOCAL for which 7-
year total take is conservatively estimated as the annual total
multiplied by seven. Not all activities occur every year. Some
activities would occur multiple times within a year, and some
activities would occur only a few times over the course of the 7-year
period. Using 7 years of the maximum number of activities each year
would vastly overestimate the amount of incidental take that would
occur over the 7-year period where the Navy knows that it will not
conduct the maximum number of activities each and every year for the 7
years.
As described above in the Description of Marine Mammals and Their
Habitat in the Area of the Specified Activities section, the 2022 final
SARs include a revision to the humpback whale stock structure in the
Pacific Ocean. In the 2020 HSTT final rule, NMFS authorized take of the
CA/OR/WA stock and Central North Pacific stock of humpback whale. Given
the revised stock structure, in this proposed rule, NMFS has reanalyzed
the potential for take of each stock of humpback whale and determined
that the Central America/Southern Mexico-CA/OR/WA, Mainland Mexico--CA/
OR/WA stock, and Hawaii stocks are likely to be taken by the Navy's
activities.
Under the new stock structure, the Hawaii stock (Hawaii DPS) is the
only stock that would occur in Hawaii. Therefore, the Hawaii stock of
humpback whale is the only humpback whale stock anticipated to be taken
by the Navy's activities in the HRC, and all takes of the Central North
Pacific stock of humpback whale that were authorized in the 2020 HSTT
final rule are anticipated to be of individuals from the new Hawaii
stock. In SOCAL, the takes of individuals from the former CA/OR/WA
stock that were authorized in the 2020 HSTT final rule are anticipated
to be of individuals from the new Central America/Southern Mexico-CA/
OR/WA and Mainland Mexico-CA/OR/WA stock.
Please see the Estimated Harassment Take from Testing Activities
and Estimated Harassment Take from Training Activities sections below
for the estimated annual and 7-year total number and type of Level A
harassment and Level B harassment for each humpback whale stock.
Estimated Harassment Take From Training Activities
For training activities, table 11 of the 2020 HSTT final rule
summarizes the Navy's take estimate and request in the 2019 Navy
application and the maximum amount and type of Level A harassment and
Level B harassment that NMFS concurred is reasonably expected to occur
by species or stock and authorized in the 2020 HSTT LOA. In the 2022
Navy application, the Navy requested no change to this authorized take,
though as described above, NMFS has since published the 2022 final
SARs, which include a revision to humpback whale stock structure. For
the estimated 7-year total amount and type of Level A harassment and
Level B harassment, see table 11 of the 2020 HSTT final rule for all
species other than humpback whale. For the estimated amount and type of
Level A harassment and Level B harassment annually, see table 41 in the
2018 HSTT final rule for all species other than humpback whale. Note
that take by Level B harassment includes both behavioral disturbance
and TTS. Navy Figures 6-12 through 6-50 in Section 6 of the 2017 Navy
application illustrate the comparative amounts of TTS and behavioral
disturbance for each species annually, noting that if a modeled marine
mammal was ``taken'' through exposure to both TTS and behavioral
disturbance in the model, it was recorded as a TTS.

[[Page 68314]]

Table 2--Humpback Whale Take From Acoustic and Explosive Effects for All Training Activities in the HSTT Study
Area
----------------------------------------------------------------------------------------------------------------
Annual 7-Year total
---------------------------------------------------------------
Species Stock Level B Level A Level B Level A
harassment harassment harassment harassment
----------------------------------------------------------------------------------------------------------------
Humpback whale \a\............ Hawaii.......... 5,604 1 34,437 12
Central America/ 585 0 \b\ 4,095 0
Southern Mexico-
CA/OR/WA
(Central
America DPS).
Mainland Mexico-- 669 1 \b\ 4,683 7
CA/OR/WA
(Mexico DPS).
----------------------------------------------------------------------------------------------------------------
\a\ Combined, takes from the Central America/Southern Mexico- CA/OR/WA stock and the Mainland Mexico CA/OR/WA
stock are equal to takes of the CA/OR/WA stock authorized in the 2020 HSTT final rule.
\b\ Unlike other species and stocks, for the Central America/Southern Mexico-CA/OR/WA stock and Mainland Mexico-
CA/OR/WA stock, NMFS estimated the 7-year take by Level B harassment by multiplying the annual estimated take
by seven. However, between the two stocks, NMFS does not anticipate that the total number of takes by Level B
harassment across all 7 years would exceed the 7,962 takes by Level B harassment from training activities that
were authorized for the CA/OR/WA stock of humpback whales in the 2020 HSTT final rule.

Estimated Harassment Take From Testing Activities
For testing activities, table 12 of the 2020 HSTT final rule
summarizes the Navy's take estimate and request in the 2019 Navy
application and the maximum amount and type of Level A harassment and
Level B harassment that NMFS concurred is reasonably expected to occur
by species or stock and authorized in the 2020 HSTT LOA. In the 2022
Navy application, the Navy requested no change to this authorized take.
For the estimated 7-year total amount and type of Level A harassment
and Level B harassment, see table 12 of the 2020 HSTT final rule. For
the estimated amount and type of Level A harassment and Level B
harassment annually, see table 42 in the 2018 HSTT final rule. Note
that take by Level B harassment includes both behavioral disturbance
and TTS. Navy Figures 6-12 through 6-50 in section 6 of the 2017 Navy
application illustrate the comparative amounts of TTS and behavioral
disturbance for each species annually, noting that if a modeled marine
mammal was ``taken'' through exposure to both TTS and behavioral
disturbance in the model, it was recorded as a TTS.

Table 3--Humpback Whale Take From Acoustic and Explosive Effects for All Testing Activities in the HSTT Study
Area
----------------------------------------------------------------------------------------------------------------
Annual 7-Year total
---------------------------------------------------------------
Species Stock Level B Level A Level B Level A
harassment harassment harassment harassment
----------------------------------------------------------------------------------------------------------------
Humpback whale \a\............ Hawaii.......... 3,522 2 23,750 19
Central America/ 291 0 \b\ 2,037 0
Southern
Mexico--CA/OR/
WA.
Mainland Mexico-- 449 0 \b\ 3,143 0
CA/OR/WA.
----------------------------------------------------------------------------------------------------------------
\a\ Combined, takes from the Central America/Southern Mexico-CA/OR/WA stock and the Mainland Mexico CA/OR/WA
stock are equal to takes of the CA/OR/WA stock authorized in the 2020 HSTT final rule.
\b\ Unlike other species and stocks, for the Central America/Southern Mexico-CA/OR/WA stock and Mainland Mexico-
CA/OR/WA stock, NMFS estimated the 7-year take by Level B harassment by multiplying the annual estimated take
by seven. However, between the two stocks, NMFS does not anticipate that the total number of takes by Level B
harassment across all 7 years would exceed the 4,961 takes by Level B harassment from testing activities that
were authorized for the CA/OR/WA stock of humpback whales in the 2020 HSTT final rule.

Estimated Take From Vessel Strikes and Explosives by Serious Injury or
Mortality Vessel Strike

Vessel strikes from commercial, recreational, and military vessels
are known to affect large whales and have resulted in serious injury
and fatalities to cetaceans (Abramson et al. 2011; Berman-Kowalewski et
al. 2010; Calambokidis, 2012; Douglas et al. 2008; Laggner, 2009;
Lammers et al. 2003; Van der Hoop et al. 2012; Van der Hoop et al.
2013; Crum et al. 2019). Records of collisions date back to the early
17th century, and the worldwide number of collisions appears to have
increased steadily during recent decades (Laist et al. 2001; Ritter
2012) due to increases in the number and speed of large vessels,
increased reporting of strikes, and increased abundance of some large
whales (Ransome et al. 2021), among other factors.
Numerous studies of interactions between surface vessels and marine
mammals have demonstrated that free-ranging marine mammals often, but
not always (e.g., McKenna et al. 2015; Smultea et al. 2022; Szesciorka
et al. 2019), engage in avoidance behavior when surface vessels move
toward them. It is not clear whether these responses are caused by the
physical presence of a surface vessel, the underwater noise generated
by the vessel, or an interaction between the two (Amaral and Carlson,
2005; Au and Green, 2000; Bain et al. 2006; Bauer 1986; Bejder et al.
1999; Bejder and Lusseau, 2008; Bejder et al. 2009; Bryant et al. 1984;
Corkeron, 1995; Erbe, 2002; F[eacute]lix, 2001; Goodwin and Cotton,
2004; Lemon et al. 2006; Lusseau, 2003; Lusseau, 2006; Magalhaes et al.
2002; Nowacek et al. 2001; Richter et al. 2003; Scheidat et al. 2004;
Simmonds, 2005; Watkins, 1986; Williams et al. 2002; Wursig et al.
1998). Several authors suggest that the noise generated during vessel
movement is probably an important factor (Blane and Jaakson, 1994;
Evans et al. 1992; Evans et al. 1994). Water disturbance may also be a
factor. These studies suggest that the behavioral responses of marine
mammals to surface vessels are similar to their behavioral responses to

[[Page 68315]]

predators. Avoidance behavior is expected to be even stronger in the
subset of instances during which the Navy is conducting training or
testing activities using active sonar or explosives.
The marine mammals most vulnerable to vessel strikes are those that
spend extended periods of time at the surface to restore oxygen levels
within their tissues after deep dives (e.g., sperm whales). In
addition, some baleen whales seem generally unresponsive to vessel
sound, making them more susceptible to vessel collisions (Nowacek et
al. 2004). These species are primarily large, slow-moving whales.
Some researchers have suggested the relative risk of a vessel
strike can be assessed as a function of animal density and the
magnitude of vessel traffic (e.g., Fonnesbeck et al. 2008; Vanderlaan
et al. 2008). Differences among vessel types also influence the
probability of a vessel strike. The ability of any ship to detect a
marine mammal and avoid a collision depends on a variety of factors,
including environmental conditions, ship design, size, speed, and
ability and number of personnel observing, as well as the behavior of
the animal. Vessel speed, size, and mass are all important factors in
determining if injury or death of a marine mammal is likely due to a
vessel strike. For large vessels, speed and angle of approach can
influence the severity of a strike. For example, Vanderlaan and Taggart
(2007) found that between vessel speeds of 8.6 and 15 kn (15.9 and 27.8
km per hour), the probability that a vessel strike is lethal increases
from 0.21 to 0.79. Large whales also do not have to be at the water's
surface to be struck. Silber et al. (2010) found when a whale is below
the surface (about one to two times the vessel draft), there is likely
to be a pronounced propeller suction effect. This suction effect may
draw the whale into the hull of the ship, increasing the probability of
propeller strikes.
There are some key differences between the operation of military
and non-military vessels, which make the likelihood of a military
vessel striking a whale lower than some other vessels (e.g., commercial
merchant vessels). Key differences include:
Many military ships have their bridges positioned closer
to the bow, offering better visibility ahead of the ship (compared to a
commercial merchant vessel);
There are often aircraft associated with the training or
testing activity (which can serve as Lookouts), which can more readily
detect cetaceans in the vicinity of a vessel or ahead of a vessel's
present course before crew on the vessel would be able to detect them;
Military ships are generally more maneuverable than
commercial merchant vessels, and if cetaceans are spotted in the path
of the ship, could be capable of changing course more quickly;
The crew size on military vessels is generally larger than
merchant ships, allowing for stationing more trained Lookouts on the
bridge. At all times when vessels are underway, trained Lookouts and
bridge navigation teams are used to detect objects on the surface of
the water ahead of the ship, including cetaceans. Additional Lookouts,
beyond those already stationed on the bridge and on navigation teams,
are positioned as Lookouts during some training events; and
When submerged, submarines are generally slow moving (to
avoid detection), and therefore, marine mammals at depth with a
submarine are likely able to avoid collision with the submarine. When a
submarine is transiting on the surface, there are Lookouts serving the
same function as they do on surface ships.
Vessel strike to marine mammals is not associated with any specific
training or testing activity but is rather a limited and sporadic, but
possible, accidental result of Navy vessel movement within the HSTT
Study Area or while in transit.
In 2009, the Navy began implementing additional mitigation measures
to further reduce the likelihood of vessel strikes. Prior to the recent
strikes in 2021 and 2023, there were two recorded U.S. Navy vessel
strikes of large whales in the HSTT Study Area between 2009 and April
2021, a period of approximately 12 years.
Since 2021 there have been five documented strikes of large whales
in SOCAL by naval vessels, three by the U.S. Navy and two by the Royal
Australian Navy. As stated previously, the U.S. Navy struck a large
whale in waters off Southern California in May 2023. Based on available
photos and video, NMFS and the Navy have determined this whale was
either a fin whale or sei whale. The U.S. Navy struck two unidentified
large whales during the months of June and July 2021, and prior to
that, on May 7, 2021, the Royal Australian Navy HMAS Sydney, a 147.5 m
(161.3 yd) Hobart Class Destroyer, struck and killed two fin whales (a
mother and her calf) while operating within SOCAL. In the case of the
Royal Australian Navy strike, the carcasses were first sighted under
the bow of the vessel while it was approaching the Naval Base in San
Diego. The whales had been pinned to a sonar dome in the front of the
vessel due to the force of water as the ship was underway. Based on
interviews with HMAS Sydney personnel, the most likely time of impact
with the two whales would have been around 6:25 a.m. when the vessel
was located near Cortes Bank, and visibility was poor. The reported
vessel speed at the estimated time of strike was 9 kn (16.7 km per
hour). One minute before the estimated strike time a lookout reported
whales off the starboard bow. The officer on-watch verbally
acknowledged the report, slowed speed, and visually tracked the whales
passing clear down the starboard side until they were clear of the
ship. The morning of the strike, the HMAS Sydney was getting into
position to participate in a U.S. Navy-led exercise later that day. Of
note, throughout the remainder of the day visibility was poor and the
vessel had implemented mitigation measures in multiple instances due to
whale occurrence. In addition to being the only documented occurrence
of a foreign military vessel strike of a large whale within the HSTT
Study Area, the HMAS Sydney vessel strike was also somewhat unique, as
compared to other reported military vessel strikes, in that two whales
were apparently struck at one time, and both remained pinned to the
front of the vessel until the vessel approached the port.
On June 29, 2021, a U.S. Navy cruiser struck an unknown whale
species approximately 95 nmi west of San Diego. The ship was returning
from Hawaii, heading to a rendezvous with a fuel replenishment vessel
(oiler) for an Underway Replenishment. Off-duty sailors noticed a group
of whales approaching the ship from the port quarter (i.e., left rear
of the ship), an area unique to cruisers with some equipment structures
blocking close aboard sight. The first indication of a whale within the
500-yd mitigation zone immediately prior to the strike was when an off-
duty sailor on the flight deck witnessed the whale briefly surface on
the aft port quarter before diving. Shortly after this occurred blood
was noticed in the wake, and a floating whale body was eventually
observed behind the ship. The ship's speed was 25 kn (46.3 km per hour)
at the estimated time the strike occurred. The Navy also noted that, on
the morning before the strike occurred, the ship had maneuvered several
times to avoid whale blows beyond the 500-yd (457.2 m) mitigation zone,
closer to 1,000 yd (914.4 m).
On July 11, 2021, a U.S. Navy cruiser struck an unknown whale
species

[[Page 68316]]

approximately 90 nmi (166.7 km) south-southwest of San Diego. The
vessel was a participant in a MTE (Large Integrated Anti-Submarine
Warfare--Composite Unit Training Exercise) within the SOCAL portion of
the action area. The vessel was maneuvering for pending flight
operations to receive an inbound helicopter. At 2:27 p.m., the
starboard lookout sighted what they believed to be a whale crossing
immediately under the vessel's bow. The conning officer attempted to
maneuver the vessel by turning to port but internal watchstanders
subsequently felt the ship shudder aft. The vessel's combat center
observed a red slick 600 yd (548.6 m) astern on a flight deck camera
and a brief surfacing of the whale itself, but no carcass was observed.
There had not been any sightings of large whales off the bow leading up
to the incident. Although the ship was traveling at 25-30 kn (46.3-55.6
km per hour) one hour before the estimated strike time, at ten minutes
before, the vessel changed course and reduced its speed to 17 kn (31.5
km per hour). These 2021 incidents were the first known U.S. Navy
vessel strikes in the HSTT Study Area since 2009.
On May 20, 2023, a U.S. Navy aircraft carrier was at sea conducting
independent, unit-level flight training for the embarked airwing
approximately 70 nmi west of San Diego. Training exercises concluded
for the day at approximately 7:44 p.m. local time. Navy personnel
discovered a whale impinged on the bow of the vessel at approximately
8:00 p.m. local time. The vessel was traveling at approximately 5 kn
and had recently made a turn to reset position for the evening when the
Navy personnel discovered the whale. Navy personnel captured video and
photos of the carcass, and based on those images, NMFS and the Navy
have determined this whale was either a fin whale or sei whale; the two
species are very similar morphologically and are difficult to
distinguish from one another at sea. Navy personnel stopped the vessel
to allow lack of momentum to dislodge the carcass from the bow, and
based on lack of further observations after the carcass dislodged, it
is believed to have sunk around 9:30 p.m. local time. Navy personnel on
board the vessel reported that they did not feel an impact from
striking the whale. Prior to the strike, between 6:45 p.m. and 7:45
p.m., the forward Lookouts on the vessel observed two whales crossing
the vessel's bow but did not provide a distance between the vessel and
the whales. One Lookout reported seeing the blow and the other reported
seeing `humps' (presumably the dorsal of the animal). Both whales were
sighted past the ship's course to the northwest. Within the same time
window, one of the aft Lookouts observed a single whale swimming
parallel to the ship and soon passed astern of the ship. During the
same time, independent of the sightings and for general movement
reasons, the ship changed speed from 17 knots to 10 knots at 7:22 p.m.
For the same reasons listed above describing why the likelihood of
a military vessel striking a whale is lower than that of some other
vessels striking whales, it is also highly unlikely that a Navy vessel
would strike a whale, dolphin, porpoise, or pinniped without detecting
it. Specifically, Navy ships have Lookouts, including on the forward
part of the ship that can visually detect a hit animal in the event
ship personnel do not feel the strike (which has occurred).
Accordingly, NMFS is confident that the Navy's reported strikes are
accurate and appropriate for use in the analysis. Navy's strict
internal procedures and mitigation requirements include reporting of
any vessel strikes of marine mammals, and the Navy's discipline,
extensive training (not only for detecting marine mammals, but for
detecting and reporting any potential navigational obstruction), and
strict chain of command give NMFS a high level of confidence that all
strikes actually get reported.
As noted above, the 2021 Royal Australian Navy vessel strikes were
first observed when the vessel came to port at Naval Base San Diego.
However, such a scenario is unlikely on a U.S. Navy vessel. While U.S.
Navy cannot speculate on the configurations of other ships bows and
even sonar dome specifications (that may be at the bow), the Navy
believes it would be implausible for a marine mammal to become lodged
on the sonar dome of a U.S. Navy ship and remain undetected due to a
technological standard operating procedure. Sonar domes on U.S. Navy
ships have a pressurized rubber window that maintains 150 pound-force
per square inch (PSI) through the ship's fire main. If anything affects
the pressure, an alarm sounds in the sonar control room. In the event
of a whale strike in that location, this alarm would alert personnel
that something hit the sonar dome. Further, the shape, hydrodynamic
design, construction using a non-abrasive material, and regular hull
cleaning procedures to remove barnacles and other growth on U.S. Navy
ships also make it unlikely that a whale would become lodged and remain
undetected on a U.S. Navy ship's bow or even sonar dome. While in the
case of the May 2023 strike, described above, a whale also became
lodged on the ship's bow, the aircraft carrier that struck the whale
does not have active or passive sonar capabilities (i.e., no sonar
dome), nor does it have a bulbous bow, and the whale was more quickly
discovered by Navy personnel.
In order to better account for the accidental nature of vessel
strikes to large whales in general and the potential risk from U.S.
Navy vessel movement within the HSTT Study Area during the remaining
period of the HSTT rule in particular, the Navy requested the HSTT rule
be modified to authorize additional incidental takes by vessel strike
based on probabilities derived from a Poisson distribution using vessel
strike data between 2009-2021 in the HSTT Study Area (the time period
from when current mitigations were instituted until the Navy conducted
the analysis for the 2022 Navy application), as well as historical at-
sea days in the HSTT Study Area from 2009-2015 and estimated at-sea
days for the period from 2016 to 2025 covered by the current
regulations. This distribution predicted the probabilities of a
specific number of strikes (n=0, 1, 2, etc.) over the remaining period
of the regulations at the time of the Navy's analysis (2022-2025).
The Navy used the two fin whale strikes (2009) and two unidentified
large whale strikes (2021) in their calculations to determine the
number of strikes likely to result from its activities over the
remaining 3 years of the rule (2023-2025, although worldwide strike
information from all Navy activities and other sources was used to
inform the species that may be struck). The Navy evaluated data
beginning in 2009 as that was the start of the Navy's Marine Species
Awareness Training and adoption of additional mitigation measures to
address vessel strike, which will remain in place along with additional
and modified mitigation measures during the 7 years of this rulemaking.
From this analysis, the Navy concluded that there was a 27 percent
chance that zero whales would be struck by Navy vessels over the
remaining period of the rule (which, at the time that the application
was submitted, was 4 years), and a 35, 23, and 10 percent chance that
one, two, or three whales, respectively, would be struck over the
remaining 4 years of the rule. Therefore, the Navy estimated that there
was some probability that the Navy could strike, and take by serious
injury or mortality, up to three large whales incidental to training
and testing

[[Page 68317]]

activities within the HSTT Study Area over what would have been the
remaining 4 years of the current authorization, and the Navy requested
authorization of two additional takes of large whales by serious injury
or mortality by vessel strike, beyond the three takes authorized by the
2020 HSTT final rule (85 FR 41780, July 10, 2020).
NMFS has since updated this analysis to reflect that an additional
strike of an unidentified large whale occurred in May 2023 (either a
fin whale or sei whale, as stated above) and that additional time has
passed since the Navy submitted the 2022 Navy application. Based on
further discussions with the Navy, NMFS has also updated the way it
calculated at-sea days. This is a different manner of calculating at-
sea days for the purposes of the strike analysis rather than a change
in Navy's activity levels. For 2010-2015, the at-sea days used in NMFS'
calculation reflected historic at-sea days in the HSTT action area
based on positional vessel data records (Mintz, 2016). While the actual
annual at-sea days from 2016-present are currently classified, NMFS'
updated calculation reflects an extrapolation of the 2010-2015 at-sea
days (using the formula y = -64x + 131555) to estimate the number of
at-sea days in 2016 (Navy, 2022). The number of at-sea days derived for
2016 was 2,056 at-sea days, which reflects the downward trend in HSTT
vessel activity from 2010-2015. Since we do not have sufficient
information to say whether or not this downward trend continued for the
years 2017-2022, we conservatively estimate the average over these
years was the same as the 2016 extrapolated value of 2,056 at-sea days.
This analysis only included at-sea days for Navy warships greater than
65 feet (i.e., destroyers are the smallest ship class included). Navy
vessels smaller than 65 feet have never reported a whale strike in the
Pacific, and therefore, we consider it unlikely that this would occur
in the remaining 2.5 years of the regulations.

Table 4--HSTT 2009 Through Mid-2023 At-Sea Days Used for the Vessel Strike Probability Calculation
----------------------------------------------------------------------------------------------------------------
Year At-sea days Derivation
----------------------------------------------------------------------------------------------------------------
2009.......................................... 4,233 Estimated average based on 2010-2015 data.
2010.......................................... 5,207 Based on positional vessel data.
2011.......................................... 4,483 Based on positional vessel data.
2012.......................................... 4,081 Based on positional vessel data.
2013.......................................... 4,041 Based on positional vessel data.
2014.......................................... 4,272 Based on positional vessel data.
2015.......................................... 3,311 Based on positional vessel data.
2016.......................................... 2,056 Extrapolated from 2010-2015 regression.
2017.......................................... 2,056 Extrapolated from 2010-2015 regression.
2018.......................................... 2,056 Extrapolated from 2010-2015 regression.
2019.......................................... 2,056 Extrapolated from 2010-2015 regression.
2020.......................................... 2,056 Extrapolated from 2010-2015 regression.
2021.......................................... 2,056 Extrapolated from 2010-2015 regression.
2022.......................................... 2,056 Extrapolated from 2010-2015 regression.
2023 (first half of year)..................... 1,028 Extrapolated from 2010-2015 regression, then
reduced by half.
----------------
2009-Mid-2023 total....................... 45,048
----------------------------------------------------------------------------------------------------------------

NMFS then used the number of past Navy vessel strikes and the at-
sea days to calculate a vessel strike rate for 2009 through mid-2023.
The estimated total number of Navy at-sea days (for vessels greater
than 65 feet) for 2009 through mid-2023 was 45,048 days. Dividing the
five known strikes during that period by the at-sea days (i.e., 5
strikes/45,048 at-sea days) results in a strike rate of 0.000111
strikes per day.
As described above, NMFS conservatively assumed that the average
number of at-sea days from mid-2023 through 2025 (the remaining period
of the regulations) will be the same as the 2016 extrapolated value of
2,056. Therefore, the estimated at-sea days within the action area for
the period from mid-2023 through 2025 is 5,140 days. NMFS multiplied
the historic daily strike rate by the estimated at-sea days from mid-
2023 through 2025 (0.000111 strikes per day x 5,140 days) to estimate
the number of whale strikes anticipated during that period. This
calculation predicts an estimated 0.57 strikes over the remaining 2.5
years of the regulations (mid-2023 through 2025).
As explained above, according to the U.S. Navy, the May 2021 vessel
strike of two fin whales by a Royal Australian Navy vessel did not
occur while that vessel was participating in a U.S. Navy-led training
exercise, and the strike of those two fin whales is not included in the
estimated take by vessel strike calculation. Instead, as noted below,
NMFS considered the 2021 vessel strike by the Royal Australian Navy
along with other strike information when determining which species
could be among the estimated large whales struck.
NMFS used a Poisson distribution to derive the probabilities of a
specific number of strikes (n=0, 1, 2, etc.) from mid-2023 through
2025, given the estimated 0.57 strikes during that period. NMFS'
probability analysis concluded that there is a 57 percent chance that
zero whales would be struck by U.S. Navy vessels over the remaining
period of the rule (mid-2023 through 2025), and a 32, 9, and 2 percent
chance that one, two, or three whales, respectively, would be struck
over the remaining 2.5 years of the regulations. Further, there is an
estimated 11 percent chance that the Navy would strike more than one
large whale over the remaining period of the rule (mid-2023 through
2025). We have assessed these probabilities and determined that the
strike up to two large whales could occur over the remaining duration
of the regulations, for a total of five takes by serious injury or
mortality of large whales by vessel strike total over the 7-year
duration of the regulations (three takes authorized in the 2020 HSTT
final rule (85 FR 41780, July 10, 2020) which have occurred, plus two
additional takes).
In addition to the reasons listed above that make it unlikely that
the Navy will hit a large whale (more maneuverable ships, larger crew,
etc.), vessel strike of dolphins, small whales, porpoises, and
pinnipeds is considered very unlikely. Dating back more than 20 years
and for as long as it has kept records, the Navy has no records of any
small whales or

[[Page 68318]]

pinnipeds being struck by a vessel as a result of Navy activities. Over
the same time period, NMFS and the Navy have only one record of a
dolphin being struck by a vessel as a result of Navy activities. The
dolphin was accidentally struck by a Navy small boat in fall 2021 in
Saint Andrew's Pass, Florida. The smaller size and maneuverability of
dolphins, small whales, and pinnipeds generally make such strikes very
unlikely. Other than this one reported strike of a dolphin in 2021,
NMFS has never received any reports from other LOA or Incidental
Harassment Authorization holders indicating that these species have
been struck by vessels. In addition, worldwide vessel strike records
show little evidence of strikes of these groups from the shipping
sector and larger vessels, and the majority of the Navy's activities
involving faster-moving vessels (that could be considered more likely
to hit a marine mammal) are located in offshore areas where smaller
delphinid, porpoise, and pinniped densities are lower. Based on this
information, NMFS concurs with the Navy's assessment and recognizes the
potential for (and is proposing for authorization) incidental take by
vessel strike of large whales only (i.e., no dolphins, small whales,
porpoises, or pinnipeds) over the course of the 7-year regulations from
training and testing activities as discussed below.
Next, after determining that take of up to five large whales could
occur, NMFS considered which species could be among the five large
whales struck. As noted in the 2018 HSTT proposed and final rules, the
2019 HSTT proposed rule, and 2020 HSTT final rule, in the 2017 Navy
rulemaking/LOA application, the Navy initially considered a weight of
evidence approach that considered relative abundance, historical strike
data over many years, and the overlap of Navy activities with the stock
distribution in their request. NMFS updated this analysis to consider
several factors, in addition to the overlap of Navy activities with
stock distribution: (1) The relative likelihood of striking one stock
versus another based on available strike data from all vessel types as
denoted in the Carretta et al. (2021; referenced in the Pacific SARs),
the Pacific and Alaska SARs (Carretta et al. 2023 and Young et al.
2023), and unpublished NMFS vessel strike data for 2019-2021; and (2)
whether the Navy has ever struck an individual from a particular
species or stock in the HSTT Study Area, and if so, how many times.
NMFS did not consider relative abundance, as was considered in previous
analyses, given that the relative abundance of a stock does not
necessarily inform its occurrence in a specific area. Further, NMFS did
not consider the historical strike data from older years (prior to
2015), given that more recent data is more relevant to determining
occurrence of, and strike risk to, various stocks. NMFS updated the
analysis with NMFS' vessel strike probability analysis for the
remaining 2.5 years of the rule and included new/updated vessel strike
data from the SARs and NMFS records for California and Hawaii.
To address number (1) above, for SOCAL, NMFS compiled information
from Carretta et al. (2021) and unpublished NMFS vessel strike data for
2020-2021 for California on known annual rates of large whale serious
injury or mortality from vessel collisions (this data includes the
strike of 2 fin whales by the Royal Australian Navy in 2021, but does
not include Navy strikes in 2021 and 2023 because the species struck is
not known). Use of Carretta et al. (2021) rather than the Pacific SAR
allows NMFS to separate strikes that occurred in California from
strikes to the same stocks that occurred in other locations. For the
HRC, NMFS compiled information from the Pacific and Alaska SARs and
unpublished NMFS vessel strike data for 2019-2021 for Hawaii on known
annual rates of large whale serious injury or mortality from vessel
collisions. The annual rates of large whale serious injury or mortality
from vessel collisions from those sources help inform the relative
susceptibility of large whale species to vessel strike in SOCAL and the
HRC; therefore, we considered only reported strikes where the species
struck was identified with sufficient certainty (i.e., ``known
strikes''). Additionally, the M/SI in the 2022 SAR considers modeled
takes for some, but not most species and stocks (i.e., M/SI for
humpback whale includes modeled takes from Rockwood et al. (2017)).
Using known strike data for all species and stocks allows us to
consider-like metrics for this comparative analysis. (Note we rely on
the M/SI estimates from the 2022 SAR in our Negligible Impact Analysis.
We also consider modeled takes of species from Rockwood et al. (2017)
in table 7). We summed the annual rates of serious injury or mortality
from vessel collisions in California and Hawaii as calculated above and
then divided each species' annual rate by this sum to get the
proportion of strikes for each species/stock (table 5).

Table 5--Annual Rates of Serious Injury and Mortality From Vessel Strike and Percentage of Total Strikes by
Species in SOCAL and the HRC
----------------------------------------------------------------------------------------------------------------
SOCAL annual HRC annual Percentage of
ESA status Species Stock known strikes known strikes total annual
(2015-2021) (2015-2021) strikes
----------------------------------------------------------------------------------------------------------------
Listed................ Blue whale........ Central North .............. 0 0.0
Pacific.
Eastern North 0.57 .............. 6.5
Pacific.
Fin whale \a\..... California, 1.57 .............. 17.8
Oregon, &
Washington.
Hawaiian.......... .............. 0 0.0
Humpback whale.... Central America/ \b\ 1 .............. 11.3
Southern Mexico-
CA/OR/WA (Central
America DPS).
Mainland Mexico-CA/
OR/WA (Mexico
DPS).
Sei whale......... Eastern North 0.14 .............. 1.6
Pacific.
Hawaiian.......... .............. 0 0.0
Gray whale........ Western North 0 .............. 0.0
Pacific.
Sperm whale....... California, 0 .............. 0.0
Oregon, &
Washington.
Hawaiian.......... .............. 0 0.0
Not listed............ Gray whale........ Eastern North 2.14 .............. 24.3
Pacific.
Bryde's whale..... ETP stock......... 0 .............. 0.0
Hawaiian.......... .............. 0 0.0
Minke whale....... CA/OR/WA.......... 0 .............. 0.0

[[Page 68319]]

Hawaiian.......... .............. 0 0.0
Humpback whale.... Hawaii (Hawaii .............. 3.4 38.5
DPS).
-------------------------------------------------
Total............. .................. .................. 8.82 ................
----------------------------------------------------------------------------------------------------------------
\a\ This includes the two fin whales struck by the Royal Australian Navy in May 2021.
\b\ This strike occurred to an individual of the CA/OR/WA stock under the previous stock structure. As such, in
its analysis, NMFS assumed that this strike could have been of either stock.

To inform the likelihood of striking a particular species of large
whale, we multiplied the percent of total annual strikes for a given
species in table 5, by the total percent likelihood of striking at
least one whale during the remaining period of the rule (2023-2025;
i.e., 43 percent, as described by the probability analysis above). We
also calculated the percent likelihood of striking a particular species
of large whale twice during the remaining period of the rule by
squaring the value estimated for the probability of striking a
particular species of whale once (i.e., to calculate the probability of
an event occurring twice, multiply the probability of the first event
by the second). The results of these calculations are reflected in the
last two columns of table 6. We note that these probabilities vary from
year to year as the average annual mortality changes depending on the
specific range of time considered; however, over the years and through
updated data in the SARs and unpublished NMFS records, stocks tend to
consistently maintain a relatively higher or relatively lower
likelihood of being struck.

Table 6--Percent Likelihood of Striking Each Stock One or Two Times Over 2.5 Years and Total Known U.S. Navy
Strikes in the HSTT Study Area
----------------------------------------------------------------------------------------------------------------
Percent Percent
Total known U.S. Navy likelihood of likelihood of
Species Stock strikes in HSTT study 1 strike over 2 strikes over
area 2.5 years 2.5 years
----------------------------------------------------------------------------------------------------------------
Blue whale........................ Central North Pacific 0.................... 0.00 0.00
Eastern North Pacific 1 in SOCAL (2004).... 2.81 0.08
Fin whale......................... CA/OR/WA............. 3 in SOCAL (2009, \b\ 7.74 \b\ 0.60
2023 \a\).
Hawaiian............. 0.................... 0.00 0.00
Humpback whale.................... Central America/ 0.................... 4.93 0.24
Southern Mexico-CA/
OR/WA (Central
America DPS).
Mainland Mexico-CA/OR/
WA (Mexico DPS).
Sei whale......................... Eastern North Pacific 1 in SOCAL (2023 \a\) 0.69 0.00
Hawaiian............. 0.................... 0.00 0.00
Gray whale........................ Western North Pacific 0.................... 0.00 0.00
Sperm whale....................... CA/OR/WA............. 0.00................. 0.00
Hawaiian............. 1 in HRC (2007)...... 0.00 0.00
Gray whale........................ Eastern North Pacific 3 in SOCAL (1993, 10.55 1.11
1998).
Bryde's whale..................... ETP stock............ 0.................... 0.00 0.00
Hawaiian............. 0.................... 0.00 0.00
Minke whale....................... CA/OR/WA............. 0.................... 0.00 0.00
Hawaii............... 0.................... 0.00 0.00
Humpback whale.................... Hawaii (Hawaii DPS).. 2 in HRC (2003)...... 16.76 2.81
----------------------------------------------------------------------------------------------------------------
\a\ Based on available photos and video, NMFS and the Navy have determined the May 2023 strike was of either a
fin whale or sei whale. In the analysis herein, NMFS has assumed that this strike could have been of either
species, and has therefore, accounted for it in both the fin whale and sei whale strike totals. Given that we
are unable to identify the species of the whales struck by the U.S. Navy in 2021, NMFS did not include the two
2021 strikes in this part of the analysis.
\b\ This includes the two fin whales struck by the Royal Australian Navy in May 2021.

The percent likelihood calculated as described above are then
considered in combination with the information indicating the known
species that the Navy has hit in the HSTT Study Area since 1991 (since
they started tracking consistently; table 6). We note that for the
lethal take of species specifically denoted in table 7 below, 47
percent of those struck by the Navy (8 of 17 in the Pacific) remained
unidentified (including the May 2023 strike, which as stated above,
NMFS and the Navy have determined was of either a fin whale or sei
whale). However, given the information on known stocks struck, the
analysis below remains appropriate. We also note that Rockwood et al.
(2017) modeled the likelihood of vessel strike of blue whales, fin
whales, and humpback whales on the U.S. West Coast (discussed in more
detail in the Serious Injury or Mortality subsection of the Preliminary
Analysis and Negligible Impact Determination section), and those
numbers help inform the relative likelihood that the Navy could hit
those stocks.
For each indicated stock, table 7 includes the percent likelihood
of

[[Page 68320]]

striking an individual whale from a particular stock during the
remaining 2.5 years of the rule once based on SAR data, Carretta et al.
(2021), and unpublished NMFS vessel strike data from 2019-2021 for
Hawaii; total strikes from Navy vessels in the HSTT Study Area, and
modeled vessel strikes from Rockwood et al. (2017). The last column
indicates the annual mortality proposed to be authorized.

Table 7--Summary of Factors Considered in Determining the Number of Individuals in Each Stock Potentially Struck by a Vessel
--------------------------------------------------------------------------------------------------------------------------------------------------------
Percent Rockwood et Annual
likelihood Total known U.S. Navy al. 2017 authorized Proposed
ESA status Species Stock of one strikes in HSTT study modeled take from annual
strike over area (1993-2009) vessel 2020 HSTT authorized
2.5 years strikes \1\ final rule take
--------------------------------------------------------------------------------------------------------------------------------------------------------
Listed.................. Blue whale.............. Central North Pacific.. 0.00 0...................... ........... ........... 0
Eastern North Pacific.. 2.81 1 in SOCAL (2004)...... 18 0.14 0.14
Fin whale............... CA/OR/WA............... \2\ 7.74 3 in SOCAL (2009, 2023 43 0.29 0.57
\3\).
Hawaii................. 0.00 0...................... ........... ........... 0
Humpback whale \4\...... Central America/ 4.93 0...................... 22 0.14 0
Southern Mexico-CA/OR/
WA (Central America
DPS).
Mainland Mexico-CA/OR/ 0.14
WA (Mexico DPS).
Sei whale............... Eastern North Pacific.. 0.69 1 in SOCAL(2023) \3\... ........... ........... 0.14
Hawaii................. 0.00 0...................... ........... ........... 0
Gray whale.............. Western North Pacific.. 0.00 0...................... ........... ........... 0
Sperm whale............. CA/OR/WA............... 0.00 0...................... ........... ........... 0
Hawaii................. 0.00 1 in HRC (2007)........ ........... 0.14 0
Not listed.............. Gray whale.............. Eastern North Pacific.. 10.55 3 in SOCAL (1993, 1998) ........... 0.29 0.57
Bryde's whale........... Eastern Tropical 0.00 0...................... ........... ........... 0
Pacific.
Hawaii................. 0.00 0...................... ........... ........... 0
Minke whale............. CA/OR/WA............... 0.00 0...................... ........... ........... 0
Hawaii................. 0.00 0...................... ........... ........... 0
Humpback whale.......... Hawaii (Hawaii DPS) \5\ 16.76 2 in HRC (2003)........ ........... 0.29 0.29
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Rockwood et al. modeled likely annual vessel strikes off the West Coast for these three species only.
\2\ This includes the two fin whales struck by the Royal Australian Navy in May 2021.
\3\ Based on available photos and video, NMFS and the Navy have determined the May 2023 strike was of either a fin whale or sei whale. In the analysis
herein, NMFS has assumed that this strike could have been of either species, and has therefore, accounted for it in both the fin whale and sei whale
strike totals.
\4\ In the 2020 HSTT final rule, take of humpback whale by serious injury and mortality by vessel strike in Southern California was attributed to the
former CA/OR/WA stock and the Mexico DPS. Text explains why takes in SOCAL come from the Mexico DPS, and therefore the Mainland Mexico-CA/OR/WA stock.
\5\ The 2022 final SAR reports vessel strike data for the Hawaii stock of humpback whales in Alaska, Washington, and Hawaii. Only vessel strike data
from Hawaii was incorporated into our analysis as Alaska and Washington are outside of the HSTT Study Area.

Accordingly, stocks that have no record of ever having been struck
by any vessel are considered to have a zero percent likelihood of being
struck by the Navy in the 7-year period of the rule. Stocks that have
never been struck by the Navy, have rarely been struck by other
vessels, and have a low percent likelihood based on the historical
vessel strike calculation are also considered to have a zero percent
likelihood to be struck by the Navy during the 7-year rule. We note
that while vessel strike records have not differentiated between
Eastern North Pacific and Western North Pacific gray whales, given
their small population size and the comparative rarity with which
individuals from the Western North Pacific stock are detected off the
U.S. West Coast, it is highly unlikely that they would be encountered,
much less struck. This rules out all but seven stocks. Further, it is
unlikely that the Hawaii stock of sperm whale would be struck given the
zero percent likelihood of striking a sperm whale as indicated by the
quantitative analysis above, the fact that the last U.S. Navy strike of
a Hawaii stock sperm whale was in 2007, before the mitigation updates
discussed above, and that, with the exception of humpback whales,
vessel strikes (both military and non-military) of other large whale
species in the HRC are extremely rare events (Carretta 2021b; Carretta
2022). (The 2020 HSTT final rule authorized 1 take (0.14 annual take)
by mortality of the Hawaii stock of sperm whale.)
As stated previously, based on available photos and video of the
whale struck by the U.S. Navy in Southern California in 2023, NMFS and
the Navy have determined this whale was either a fin whale or sei
whale. While the species of the two whales struck by the U.S. Navy in
2021 are unknown, given the following factors, NMFS expects these
strikes may have been CA/OR/WA fin whales or Eastern North Pacific
(ENP) gray whales, or some combination of these two stocks. These
species have the highest annual rates of mortality/serious injury (M/
SI) from vessel collision in California (1.57, 2.14, respectively, as
noted above; which is approximately one and a half to two times higher
than the species with the next highest strike rate, humpback whale, and
approximately two to four times higher than the strike rate of blue
whale). Additionally, gray whale and fin whale have the most recorded
vessel strike incidents by military vessels in SOCAL and are the only
stocks known to have been hit more than one time by naval vessels in
the SOCAL portion of the HSTT Study Area (3 gray whale strikes by the
U.S. Navy (1993, 1998), 2 or 3 fin whale strikes by the U.S. Navy
(2009, potentially 2023), and 2 fin whale strikes by the Royal
Australian Navy (2021)). Further, accounting for undocumented vessel
strikes, Rockwood et al. (2021) estimated that in their study area off
Southern California from 2012-2018, on average 8.9 blue, 4.6 humpback,
and 9.7 fin whales were killed by civilian vessel strikes from June to
November each year. In addition, they estimated that, on average, 5.7
humpback whales were killed by civilian vessel strike from January-
April per year (Rockwood et al. 2021). For fin whales in particular,
model-predicted densities of large whales in the Southern California
Bight from May to July 2021 (the time period during which the 2021
strikes of two unidentified whales by the U.S. Navy occurred) estimated
fin whale abundance as being nearly an order of magnitude higher than
either blue or humpback whale abundance during this time period (Becker
et al. 2020; Zickel

[[Page 68321]]

et al. 2021). Ship-whale encounter models for the U.S. West Coast
Exclusive Economic Zone also indicated that vessel strike mortality
estimates for fin whales were significantly higher than for blue whales
and humpback whales (Rockwood et al. 2017). The comparatively higher
modeled vessel strike rates for fin whales result from both the larger
population as well as the more offshore distribution that overlaps
significantly with several major shipping routes for a much greater
spatial extent (Rockwood et al. 2017). Based on 1,243 visual boat-based
sightings of 2,638 fin whales from 1991-2011, Calambokidis et al.
(2015) found fin whale concentration areas included the San Clemente
Basin where the 2021 Navy vessel strikes occurred (Tanner and Cortez
Banks area and the shelf edge west of San Nicolas Island were also
reported as fin whale concentration areas). There are two different
populations of fin whales that occur in the Southern California Bight:
a seasonal population, and a population that occurs year-round with
offshore/inshore movements (Campbell et al. 2015; Falcone et al. 2022).
This would likely make fin whales more susceptible to vessel strike
year-round, as compared to other large whale species that may occur
seasonally within SOCAL. Based on all of these factors, there is a
reasonable likelihood that the CA/OR/WA stock of fin whales or ENP
stock of gray whales could be struck twice during the remaining 2.5
years of the rule. Therefore, we propose that, of the five total takes
by serious injury or mortality by vessel strike of large whales
proposed to be authorized, up to four of those takes could be of the
CA/OR/WA stock of fin whale or the ENP stock of gray whale given that
the two strikes of unidentified large whales in 2021 could have been of
either stock. Further, consistent with the 2020 HSTT final rule, we
propose that, of the five total takes by serious injury or mortality by
vessel strike of large whales proposed to be authorized, up to two of
those takes could occur in Hawaii, and therefore be of individuals of
the Hawaii stock of humpback whale.
Based on the information summarized in table 7 and the fact that
there is the potential for up to two large whales to be struck over the
remaining 2.5 years of the rule (five strikes over the full 7-year rule
period), one individual from the Eastern North Pacific stock of blue
whale, Mainland Mexico-CA/OR/WA stock of humpback whale, or Eastern
North Pacific stock of sei whale could be among the two whales struck
during the remaining effective period of the regulations (2023-2025).
The total strikes of Eastern North Pacific blue whales and the percent
likelihood of striking one based on the historic strike calculation
above can both be considered moderate compared to other stocks, and the
Navy struck a blue whale in 2004 (based on the historic strike
calculation, the likelihood of striking two blue whales is well below
one percent (table 6)). Therefore, we consider it reasonably likely
that the Navy could strike one individual over the course of the 7-year
rule, and given that we do not expect that the 2023 strike nor either
of the 2021 U.S. Navy strikes of unidentified large whales were blue
whales, we expect that this strike could occur during the remaining 2.5
years of the rule. The total strikes of Eastern North Pacific sei
whales are low compared to other stocks, but NMFS and the Navy think it
is possible that the Navy may have struck a sei whale in SOCAL in 2023.
Therefore, we consider it reasonably likely that the Navy could strike
a sei whale over the remaining 2.5 years of the rule. The Navy has not
hit a humpback whale in the SOCAL portion of the HSTT Study Area.
However, in 2016 a U.S. Coast Guard vessel participating in a Navy
event struck a humpback whale in Hood Canal, and as a species,
humpbacks have a moderate to high number of total strikes and percent
likelihood of being struck. Although the likelihood of Central America/
Southern Mexico-CA/OR/WA (Central America DPS) or Mainland Mexico-CA/
OR/WA (Mexico DPS) humpback whales being struck by any vessel type is
moderate to high relative to other stocks, the distribution of the
Mexico DPS versus the Central America DPS, as well as the distribution
of overall vessel strikes inside versus outside of the SOCAL area (the
majority are outside), supports the reasonable likelihood that the Navy
could strike one individual humpback whale from the Mainland Mexico-CA/
OR/WA stock (Mexico DPS) over the 7-year duration of the rule, as
described below.
Regarding the likelihood of striking a humpback whale from a
particular DPS, we evaluated the relative abundance of each of these
DPS in California waters. Curtis et al. (2022) estimated the abundance
of the Central America DPS to be 1,496 whales. From Wade et al. (2017),
about 93 percent (or 1,391 whales) of these humpbacks that winter in
Central America will move to Oregon/California in the summer months.
While there is currently no abundance estimate for the Mexico DPS, an
estimated 3,477 whales from the Mexico DPS feed off the U.S. West Coast
(Calambokidis and Barlow 2020; Curtis 2022). Based on this information,
we estimate that approximately 30 percent of the humpback whales off
the coast of California may be from the Central America DPS with the
remaining 70 percent are expected to be from the Mexico DPS. Therefore,
we anticipate that if a Navy vessel strike of a humpback whale were to
occur within SOCAL, it would likely be from the Mexico DPS. Last,
Rockwood et al. (2017) supports a relative likelihood of 1:1:2 for
striking blue whales, humpback whales, and fin whales off the U.S West
Coast (though as noted above, more recent data suggests that the
relative likelihood of striking a fin whale is higher and suggests that
the two 2021 U.S. Navy vessel strikes of unidentified large whales may
have been fin whales), which, in consideration of more recent data also
supports the proposed authorized take included in this rule, which is
1, 1, and 4, respectively over the 7-year period. For these reasons,
one lethal take of a Mainland Mexico-CA/OR/WA humpback whale (Mexico
DPS) could occur and is proposed for authorization.
For Hawaii stocks, given that all known vessel strikes between 2015
and 2021 were of humpback whales, we anticipate that any vessel strike
of a large whale in Hawaii would be of the Hawaii stock of humpback
whale. Given that this stock has the highest percentage of total annual
strikes (38.5 percent) and a 2.81 percent chance of being struck twice
over the remaining 2.5 years (more than twice that of the species with
the next highest percentage, gray whale), NMFS proposes to authorize
two lethal takes of Hawaii humpback whales.
As described above, the Navy's analysis suggests and NMFS' analysis
concurs that the likelihood of vessel strikes to the stocks below is
discountable due to the stocks' relatively low occurrence in the HSTT
Study Area, particularly in core HSTT training and testing subareas,
and the fact that the stocks have not been struck by the Navy and are
rarely, if ever, recorded struck by other vessels. Therefore, NMFS is
not proposing to authorize lethal take for the following stocks: Blue
whale (Central North Pacific stock), Bryde's whale (Eastern Tropical
Pacific stock and Hawaii stock), fin whale (Hawaii stock), gray whale
(Western North Pacific stock), humpback whale (Central America/Southern
Mexico-CA/OR/WA stock, Central America DPS), minke whale (CA/OR/WA
stock and Hawaii stock), sei whale (Hawaii stock), and sperm

[[Page 68322]]

whale (CA/OR/WA stock and Hawaii stock).
Also of note, while information on past Navy vessel strikes can
serve as a reasonable indicator of future vessel strike risk, future
conditions may differ from the past in ways that could influence the
likelihood of a large whale vessel strike occurring. In general, the
magnitude of vessel strike risk may be increasing over time as many
whale populations are gradually recovering from centuries of commercial
whaling (Redfern et al. 2020). Increased vessel strike risk off
California in recent decades has been associated with increases in the
abundance of fin and humpback whale populations in the North Pacific
(Redfern et al. 2020). It has also been suggested that the blue whale
population in the Eastern North Pacific, inclusive of the SOCAL portion
of the action area, is at carrying capacity and recovered to pre-
whaling levels (Monnahan et al. 2014). In addition, the magnitude of
risk may also be affected by shifts in whale distributions over time in
response to environmental factors including climate change, marine
heatwaves, and associated changes in prey distribution.
Historically, military vessel strikes of large whales within the
HSTT Study Area have been rare events with only seven such strikes
occurring over the past 14 years, five U.S. Navy strikes, and two Royal
Australian Navy strikes. However, the fact that four of these strikes
occurred within a 3-month period (May-July) in 2021, and two occurred
within a 4-month period (February-May) in 2009, suggests that military
vessel strikes in SOCAL can be both highly episodic and clustered. The
four large whale strikes in 2021 (two strikes of unidentified large
whales by the U.S. Navy and two fin whale strikes by the Royal
Australian Navy) appear to be outliers in the time series of military
vessel strikes in SOCAL for that period. However, particularly in
consideration of the 2023 U.S. Navy strike, these strikes could also
represent an early indicator of an increased military vessel strike
risk within SOCAL based on the factors discussed above. Results from a
survey of whale watching vessel operators and crew in Southern
California, combined with remote sensing data in the area, suggest that
the number of large whales may have been greater in May through July of
2021 compared with previous years in certain high military vessel
traffic and ``core'' use HSTT areas off southern California,
particularly farther offshore as well as closer to shore off San Diego
Bay (Zickel MJ et al. 2021).
In conclusion, while take by vessel strike across any given year is
sporadic, based on the information and analysis above, including
consideration of the 2021 and 2023 strikes by the U.S. Navy, NMFS
anticipates no more than five takes of large whales by M/SI could occur
over the 7-year period of the rule. Of those five whales over the 7-
years, no more than four may come from the following stocks: gray whale
(Eastern North Pacific stock) and fin whale (CA/OR/WA stock). No more
than two may come from the Hawaii stock of humpback whales. No more
than one may come from the following stocks: blue whale (Eastern North
Pacific stock), sei whale (Eastern North Pacific), and humpback whale
(Mexico-North Pacific stock or Mainland Mexico-CA/OR/WA, Mexico DPS).
Accordingly, NMFS has evaluated under the negligible impact standard
the M/SI of 0.14, 0.29, or 0.57 whales annually from each of these
species or stocks (i.e., 1, 2, or 4 takes, respectively, divided by 7
years to get the annual number), along with the expected incidental
takes by harassment.

Explosives

The Navy's model and quantitative analysis process used for the
2018 HSTT FEIS/OEIS and in the Navy's 2017 and 2019 applications to
estimate potential exposures of marine mammals to explosive stressors
is detailed in the technical report titled Quantifying Acoustic Impacts
on Marine Mammals and Sea Turtles: Methods and Analytical Approach for
Phase III Training and Testing report (U.S. Department of the Navy,
2018). Specifically, over the course of a modeled maximum year of
training and testing, the Navy's model and quantitative analysis
process estimates M/SI of two short-beaked common dolphin and one
California sea lion as a result of exposure to explosive training and
testing activities (please see section 6 of the 2017 Navy application
where it is explained how maximum annual estimates are calculated).
Over the 7[hyphen]year period of the 2020 HSTT regulations, M/SI of 8
short-beaked common dolphins and 5 California sea lions (13 marine
mammals in total) is estimated as a result of exposure to explosive
training and testing activities. NMFS proposes no changes to the
authorization of take by M/SI as a result of explosive use as the Navy
proposes no changes to its activities from that described in the 2018
HSTT final rule, and after reviewing all new information, we find that
our previous analyses remain applicable. Please refer to the 2018 HSTT
final rule and 2020 HSTT final rule for additional information.

Proposed Mitigation Measures

Under section 101(a)(5)(A) of the MMPA, NMFS must set forth the
permissible methods of taking pursuant to the activity, and other means
of effecting the least practicable adverse impact on the species or
stock(s) and its habitat, paying particular attention to rookeries,
mating grounds, and areas of similar significance, and on the
availability of the species or stock(s) for subsistence uses (``least
practicable adverse impact''). NMFS does not have a regulatory
definition for least practicable adverse impact. The 2004 NDAA amended
the MMPA as it relates to military readiness activities and the
incidental take authorization process such that a determination of
``least practicable adverse impact'' shall include consideration of
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity. For the full
discussion of how NMFS interprets least practicable adverse impact,
including how it relates to the negligible-impact standard, see the
Mitigation Measures section in the 2018 HSTT final rule.
Section 101(a)(5)(A)(i)(II) requires NMFS to issue, in conjunction
with its authorization, binding--and enforceable--restrictions (in the
form of regulations) setting forth how the activity must be conducted,
thus ensuring the activity has the ``least practicable adverse impact''
on the affected species or stocks. In situations where mitigation is
specifically needed to reach a negligible impact determination, section
101(a)(5)(A)(i)(II) also provides a mechanism for ensuring compliance
with the ``negligible impact'' requirement. Finally, the least
practicable adverse impact standard also requires consideration of
measures for marine mammal habitat, with particular attention to
rookeries, mating grounds, and other areas of similar significance, and
for subsistence impacts, whereas the negligible impact standard is
concerned solely with conclusions about the impact of an activity on
annual rates of recruitment and survival.\1\ In evaluating what
mitigation measures are appropriate, NMFS considers the potential
impacts of the Specified Activities, the availability of measures to
minimize those potential impacts, and the practicability of
implementing those measures, as we

[[Page 68323]]

describe below. This proposed rule includes all mitigation measures
required by the 2020 HSTT final rule (though two have been modified in
this proposed rule), and our discussion in that rule remains complete
and accurate (including reference to the 2018 HSTT final rule), except
as described below.
---------------------------------------------------------------------------

\1\ Outside of the military readiness context, mitigation may
also be appropriate to ensure compliance with the ``small numbers''
language in MMPA sections 101(a)(5)(A) and (D).
---------------------------------------------------------------------------

Implementation of Least Practicable Adverse Impact Standard

Our evaluation of potential mitigation measures includes
consideration of two primary factors:
(1) The manner in which, and the degree to which, implementation of
the potential measure(s) is expected to reduce adverse impacts to
marine mammal species or stocks, their habitat, and their availability
for subsistence uses (where relevant). This analysis considers such
things as the nature of the potential adverse impact (such as
likelihood, scope, and range), the likelihood that the measure will be
effective if implemented, and the likelihood of successful
implementation; and
(2) The practicability of the measure(s) for applicant
implementation. Practicability of implementation may consider such
things as cost, impact on activities, and, in the case of a military
readiness activity, specifically considers personnel safety,
practicality of implementation, and impact on the effectiveness of the
military readiness activity.
While the language of the least practicable adverse impact standard
calls for minimizing impacts to affected species or stocks, we
recognize that the reduction of impacts to those species or stocks
accrues through the application of mitigation measures that limit
impacts to individual animals. Accordingly, NMFS' analysis focuses on
measures that are designed to avoid or minimize impacts on individual
marine mammals that are likely to increase the probability or severity
of population-level effects.
While direct evidence of impacts to species or stocks from a
specified activity is rarely available, and additional study is still
needed to understand how specific disturbance events affect the fitness
of individuals of certain species, there have been improvements in
understanding the process by which disturbance effects are translated
to the population. With recent scientific advancements (both marine
mammal energetic research and the development of energetic frameworks),
the relative likelihood or degree of impacts on species or stocks may
often be inferred given a detailed understanding of the activity, the
environment, and the affected species or stocks--and the best available
science has been used here. This same information is used in the
development of mitigation measures and helps us understand how
mitigation measures contribute to lessening effects (or the risk
thereof) to species or stocks. We also acknowledge that there is always
the potential that new information, or a new recommendation could
become available in the future and necessitate reevaluation of
mitigation measures (which may be addressed through adaptive
management) to see if further reductions of population impacts are
possible and practicable.
In the evaluation of specific measures, the details of the
specified activity will necessarily inform each of the two primary
factors discussed above (expected reduction of impacts and
practicability), and are carefully considered to determine the types of
mitigation that are appropriate under the least practicable adverse
impact standard. Analysis of how a potential mitigation measure may
reduce adverse impacts on a marine mammal stock or species,
consideration of personnel safety, practicality of implementation, and
consideration of the impact on effectiveness of military readiness
activities are not issues that can be meaningfully evaluated through a
yes/no lens. The manner in which, and the degree to which,
implementation of a measure is expected to reduce impacts, as well as
its practicability in terms of these considerations, can vary widely.
For example, a time/area restriction could be of very high value for
decreasing population-level impacts (e.g., avoiding disturbance of
feeding females in an area of established biological importance) or it
could be of lower value (e.g., decreased disturbance in an area of high
productivity but of less firmly established biological importance).
Regarding practicability, a measure might involve restrictions in an
area or time that impede the Navy's ability to certify a strike group
(higher impact on mission effectiveness), or it could mean delaying a
small in-port training event by 30 minutes to avoid exposure of a
marine mammal to injurious levels of sound (lower impact). A
responsible evaluation of ``least practicable adverse impact'' will
consider the factors along these realistic scales. Accordingly, the
greater the likelihood that a measure will contribute to reducing the
probability or severity of adverse impacts to the species or stock or
its habitat, the greater the weight that measure is given when
considered in combination with practicability to determine the
appropriateness of the mitigation measure, and vice versa. In the
evaluation of specific measures, the details of the specified activity
will necessarily inform each of the two primary factors discussed above
(expected reduction of impacts and practicability), and will be
carefully considered to determine the types of mitigation that are
appropriate under the least practicable adverse impact standard. For
more detail on how we apply these factors, see the discussion in the
Mitigation Measures section of the 2018 HSTT final rule.
Assessment of Mitigation Measures for HSTT Rule
NMFS fully reviewed the Navy's specified activities and the
mitigation measures for the 2020 HSTT final rule and determined, with
the addition of the new and modified measures discussed herein, and
after consideration of the new information and studies described above,
that the proposed mitigation measures would result in the least
practicable adverse impact on marine mammals (see the 2019 Navy
application and the 2018 HSTT final rule for detailed information on
the Navy's mitigation measures, with the exception of the new and
modified measures described herein). NMFS worked with the Navy in the
development of the Navy's mitigation measures, which were informed by
years of implementation and monitoring. A complete discussion of the
Navy's evaluation process used to develop, assess, and select
mitigation measures, which was informed by input from NMFS, can be
found in Chapter 5 (Mitigation) of the 2018 HSTT FEIS/OEIS. The process
described in Chapter 5 (Mitigation) of the 2018 HSTT FEIS/OEIS robustly
supports NMFS' independent evaluation of whether the mitigation
measures would meet the least practicable adverse impact standard. The
Navy has implemented the mitigation measures under the 2020 HSTT
regulations and would be required to continue implementation of the
mitigation measures identified in this rulemaking for the full 7 years
it covers to avoid or reduce potential impacts from acoustic,
explosive, and physical disturbance and vessel strike stressors.
The Navy also evaluated numerous measures in the 2018 HSTT FEIS/
OEIS that were not included in the 2017 Navy application, and NMFS
independently reviewed and considered all new information, and
continues to concur with Navy's analysis that their inclusion

[[Page 68324]]

was not appropriate under the least practicable adverse impact
standard. The Navy considered these additional potential mitigation
measures in two groups. First, Chapter 5 (Mitigation) of the 2018 HSTT
FEIS/OEIS, in the Measures Considered but Eliminated section, includes
an analysis of an array of different types of mitigation that have been
recommended over the years by NGOs or the public, through scoping or
public comment on environmental compliance documents. Appendix K
(Geographic Mitigation Assessment) of the 2018 HSTT FEIS/OEIS includes
an in-depth analysis of time/area restrictions that have been
recommended over time or previously implemented as a result of
litigation.
Below, we summarize the mitigation measures (organized into
procedural measures and mitigation areas) that NMFS has determined will
ensure the least practicable adverse impact on all affected species and
stocks and their habitat, including the specific considerations for
military readiness activities, and including several measures that are
new or modified since publication of the 2020 HSTT final rule.
In its 2022 application, the Navy proposed no changes to the
procedural or geographic mitigation measures in the 2020 HSTT final
rule. NMFS reviewed new information potentially pertinent to mitigation
of the Navy's training and testing activities. While Lookouts are
essential to detecting the potential for and potentially avoiding a
vessel strike of a marine mammal, NMFS and the Navy have always
acknowledged that Lookouts cannot prevent all vessel strikes. The
recent U.S. Navy and Royal Australian Navy vessel strikes appear to
confirm this, as these strikes occurred when Lookouts were posted. As
acknowledged above, these recent incidents may represent an early
indicator of an increased military vessel strike risk within SOCAL.
Recent reports appear to reflect the sporadic, episodic, or clustered
nature of vessel strike or may reflect a trend of increased large whale
presence in this area in the early summer months. NMFS and Navy have
discussed the circumstances of each of the recent strikes, including
the Royal Australian Navy strike, and discussed ways of improving
strike mitigation. In these further conversations, NMFS and the Navy
developed several new and modified mitigation measures in comparison to
those included in the 2020 HSTT final rule.
For vessel movement, the 2020 HSTT final rule required that ``When
underway Navy personnel must observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel must maneuver
to maintain distance.'' This measure has been updated to state that
reducing speed may be an appropriate way to maneuver. The revised
measure states that ``When underway, Navy personnel must observe the
mitigation zone for marine mammals; if marine mammals are observed,
Navy personnel must maneuver (which may include reducing speed as the
mission or circumstances allow) to maintain distance.'' Of note,
between 2009 and 2021 (the most recent year for which data is
available), U.S. Navy vessels in the SOCAL portion of the HSTT Study
Area maneuvered 316 times to avoid large whales during MTEs. The years
2017 and 2021 had the highest number of maneuvers (n=64 and n=82,
respectively). In all years for which data is available (2009 to 2021),
Navy cruisers and destroyers account for 51 to 100 percent of maneuvers
during MTEs. With this modified measure, NMFS is emphasizing that Navy
personnel should consider reducing speed (as mission or circumstances
allow) when maneuvering to avoid marine mammals, though this modified
measure does not require reduction of vessel speed for reasons
explained in Chapter 5 (Mitigation) of the 2018 HSTT FEIS/OEIS, in the
Measures Considered but Eliminated section (i.e., requirements to
reduce vessel speeds would have significant direct negative effects on
mission effectiveness).
This proposed rule also requires that Navy personnel must send
alerts to Navy vessels of increased risk of strike following any
reported Navy vessel strike in the HSTT Study Area.
Further, the 2020 HSTT final rule included a requirement for Navy
personnel to issue seasonal awareness notification messages to alert
ships and aircraft to the possible presence of blue whales (June-
October), humpback whales (November-April), gray whales (November-
March), or fin whales (November-May). These messages assist in
maintaining safety of navigation and in avoiding interactions with
large whales during transits. Platforms must use the information from
the awareness notification messages to assist their visual observation
of applicable mitigation zones during training and testing activities
and to aid in the implementation of procedural mitigation. This
proposed rule requires the Navy to re-title the spring blue whale
message (released in June) to a large whale awareness message inclusive
of typical spring-summer large whales in southern California (mainly
blue, fin, and humpback whales). Furthermore, rather than tying the
message release to a specific month, the message would be for a period
based on predicted oceanographic conditions for a given year (e.g.,
May-November, April-November, etc.). The Navy will also evaluate
information obtained from NMFS' Southwest Fisheries Science Center
scientists, soon to be promulgated revised West Coast BIAs, and other
oceanographic or predictive models for guiding message text
descriptions of whale occurrence in Southern California. The
improvement will emphasize that when a marine mammal is spotted, this
may be an indicator that additional marine mammals are present and
nearby, and increased vigilance and awareness of Navy personnel is
warranted.
The proposed rule also contains a new mitigation measure in which
Navy personnel would issue real-time notifications to Navy vessels of
large whale aggregations (four or more whales) within 1 nmi (1.9 km) of
a Navy vessel in a select area of SOCAL (Of note, the four whales do
not have to be the same species and do not have to be part of the same
group (e.g., two whales of one species sighted at a distance off the
port side at 500 yd (457.2 m) and two more whales of another species
sighted off the starboard side at 500 yd (457.2 m) would be considered
an aggregation under this measure)). This measure would apply to the
area between 32-33 degrees North and 117.2-119.5 degrees West, which
includes the locations where recent (2009, 2021, 2023) strikes
occurred, and historic locations where strikes occurred when precise
latitude and longitude were known.
Of note, in order to improve mitigation effectiveness, in fall 2022
the Navy made several changes to its Lookout training. The Navy revised
its basic Lookout training materials to improve marine mammal awareness
and spotting techniques through updates to the Marine Mammal chapter of
the Navy's September 2022 Lookout Training Handbook. Further, the Navy
integrated improved Lookout training into a new generation of a
shipboard simulator at its recruit training center in the Great Lakes.
This simulator enhances new sailor knowledge and skill under realistic
training scenarios. Last, the Navy will evaluate future revisions to
online or DVD Marine Species Awareness Training video training to
emphasize that when a protected species is spotted, this may be an
indicator that additional marine mammals are present and nearby, and
the vessel should take this into consideration when transiting.

[[Page 68325]]

In addition to Lookouts required under this proposed rule, the Navy
mandates the number of Lookouts on underway vessels per internal policy
documents, including the Surface Ship NAVDORM. As described in the
Standard Operating Procedures section, in 2021, NAVDORM policy changed
to require three Lookouts on most classes of surface ship, including
destroyers and cruisers. However, the Navy asserts that always
including three Lookouts on these vessels in the future as a required
mitigation measure is not practicable because lookout numbers are
subject to change based on national security needs, including manning
and staffing requirements. As such, although the Navy describes these
additional Lookouts in its application under the mitigation section,
NMFS has not considered the potential presence of two additional
lookouts when considering Navy's mitigation effectiveness. Please see
the Proposed Reporting section for additional detail on this proposed
requirement.
With the exception of Oedekoven and Thomas (2022) described above,
there is no new information that affects NMFS' assessment of the
applicability or effectiveness of the measures included in the 2018
HSTT final rule over the remainder of the 7-year period. As stated
above in the Potential Effects of Specified Activities on Marine
Mammals and Their Habitat section, while (Oedekoven and Thomas, 2022)
suggests that detection of marine mammals is less certain than
previously assumed at certain distances, model assumptions may still
underestimate Lookout effectiveness in some cases. Additionally,
maneuvering data summarized above demonstrates that Navy vessels are
successfully maneuvering to avoid striking sighted marine mammals in
most cases, despite the Oedekoven and Thomas (2022) results. Further,
as described above, Navy and NMFS have developed modified or new
mitigation in this proposed rule which are anticipated to further
reduce the risk of vessel strike of large whales.
In summary, and as described in more detail above regarding vessel
strike, the Navy has agreed to procedural mitigation measures that will
reduce the probability and/or severity of impacts expected to result
from acute exposure to acoustic sources or explosives, vessel strike,
and impacts to marine mammal habitat. Specifically, the Navy will use a
combination of delayed starts, powerdowns, and shutdowns to minimize or
avoid M/SI and minimize the likelihood or severity of PTS or other
injury, and reduce instances of TTS or more severe behavioral
disturbance caused by acoustic sources or explosives. The Navy will
also implement multiple time/area restrictions (several of which were
added in the 2018 HSTT final rule since the previous HSTT MMPA
incidental take rule) that would reduce take of marine mammals in areas
or at times where they are known to engage in important behaviors, such
as feeding or calving, where the disruption of those behaviors would
have a higher probability of resulting in impacts on reproduction or
survival of individuals that could lead to population-level impacts.
Table 8 provides the Navy's required procedural mitigation measures for
environmental awareness and education and vessel movement as well as
summaries of the Navy's procedural mitigation measures for other
activities. Table 9 provides summaries of mitigation areas for the HSTT
Study Area.
NMFS and the Navy considered mitigation areas to protect marine
mammals, including odontocetes with small or resident populations in
the HSTT Study Area. This included consideration of new mitigation
areas based on newly identified BIAs in Hawaii (Kratofil et al. 2023).
Including additional mitigation areas beyond that included in the 2020
HSTT final rule is impracticable given overlap with critical Navy
training areas in the HRC. However, many of the BIAs identified in
Kratofil et al. 2023 partially or fully overlap the mitigation areas
included in the 2020 HSTT final rule and proposed herein.

Table 8--Summary of Procedural Mitigation
------------------------------------------------------------------------
Mitigation zone sizes and other
Stressor or activity requirements
------------------------------------------------------------------------
Environmental Awareness and Education.. This mitigation
applies to all training and
testing activities, as
applicable.
Mitigation
Requirements:
[cir] Appropriate Navy
personnel (including
civilian personnel)
involved in mitigation and
training or testing
activity reporting under
the specific activities
must complete one or more
modules of the U.S. Navy
Afloat Environmental
Compliance Training Series,
as identified in their
career path training plan.
Modules include:
[ssquf] Introduction to
the U.S. Navy Afloat
Environmental Compliance
Training Series. The
introductory module
provides information on
environmental laws (e.g.,
ESA, MMPA) and the
corresponding
responsibilities that are
relevant to Navy training
and testing activities.
The material explains why
environmental compliance
is important in
supporting the Navy's
commitment to
environmental
stewardship.
[ssquf] Marine Species
Awareness Training. All
bridge watch personnel,
Commanding Officers,
Executive Officers,
maritime patrol aircraft
aircrews,
anti[hyphen]submarine
warfare and mine warfare
rotary-wing aircrews,
Lookouts, and equivalent
civilian personnel must
successfully complete the
Marine Species Awareness
Training prior to
standing watch or serving
as a Lookout. The Marine
Species Awareness
Training provides
information on sighting
cues, visual observation
tools and techniques, and
sighting notification
procedures. Navy
biologists developed
Marine Species Awareness
Training to improve the
effectiveness of visual
observations for
biological resources,
focusing on marine
mammals and sea turtles,
and including floating
vegetation, jellyfish
aggregations, and flocks
of seabirds.
[ssquf] U.S. Navy
Protective Measures
Assessment Protocol. This
module provides the
necessary instruction for
accessing mitigation
requirements during the
event planning phase
using the Protective
Measures Assessment
Protocol software tool.
[ssquf] U.S. Navy Sonar
Positional Reporting
System and Marine Mammal
Incident Reporting. This
module provides
instruction on the
procedures and activity
reporting requirements
for the Sonar Positional
Reporting System and
marine mammal incident
reporting.
Active Sonar........................... Depending on sonar source:

[[Page 68326]]

1,000 yd (914.4 m)
power down, 500 yd (457.2
m) power down, and 200 yd
(182.9 m) shut down
200 yd (182.9 m)
shut down.
Air Guns............................... 150 yd (137.2 m).
Pile Driving........................... 100 yd (91.4 m).
Weapons Firing Noise................... 30 degrees on either
side of the firing line out to
70 yd (64 m).
Explosive Sonobuoys.................... 600 yd (548.6 m).
Explosive Torpedoes.................... 2,100 yd (1,920.2 m).
Explosive Medium-Caliber and Large- 1,000 yd (914.4 m;
Caliber Projectiles. large-caliber projectiles).
600 yd (548.6 m;
medium-caliber projectiles
during surface-to-surface
activities).
200 yd (182.9 m;
medium-caliber projectiles
during air-to-surface
activities).
Explosive Missiles and Rockets......... 2,000 yd (1,828.8 m;
21-500 lb. net explosive
weight).
900 yd (823 m; 0.6-20
lb. net explosive weight).
Explosive Bombs........................ 2,500 yd (2,286 m).
Sinking Exercises...................... 2.5 nmi (4.6 km).
Explosive Mine Countermeasure and 2,100 yd (1,929.2 m; 6-
Neutralization Activities. 650 lb net explosive weight).
600 yd (548.6 m; 0.1-5
lb net explosive weight).
Explosive Mine Neutralization 1,000 yd (914.4 m; 21-
Activities Involving Navy Divers. 60 lb net explosive weight for
positive control charges and
charges using time-delay
fuses).
500 yd (457.2 m; 0.1-
20 lb net explosive weight for
positive control charges).
Underwater Demolition Multiple Charge-- 700 yd (640.1 m).
Mat Weave and Obstacle Loading.
Maritime Security Operations--Anti- 200 yd (182.9 m).
Swimmer Grenades.
Vessel Movement........................ The mitigation must
not be applied if: (1) The
vessel's safety is threatened,
(2) the vessel is restricted
in its ability to maneuver
(e.g., during launching and
recovery of aircraft or
landing craft, during towing
activities, when mooring), (3)
the vessel is operated
autonomously, or (4) when
impractical based on mission
requirements (e.g., during
Amphibious Assault--Battalion
Landing exercises).
Number of Lookouts and
Observation Platform:
[cir] 1 Lookout must be on
the vessel that is
underway.\1\
Mitigation
Requirements:
[cir] Mitigation zones:--500
yd (457.2 m) around
whales.--200 yd (182.9 m)
around other marine mammals
(except bow-riding dolphins
and pinnipeds hauled out on
man-made navigational
structures, port
structures, and vessels).
[cir] During the activity:--
When underway, Navy
personnel must observe the
mitigation zone for marine
mammals; if marine mammals
are observed, Navy
personnel must maneuver
(which may include reducing
speed as the mission or
circumstances allow) to
maintain distance.
Additional
requirements:
[cir] If a marine mammal
vessel strike occurs, Navy
personnel must follow the
established incident
reporting procedures. Navy
personnel must also send
alerts to Navy vessels of
increased risk of strike
following any reported Navy
vessel strike in the HSTT
Study Area.
[cir] Navy personnel must
issue real-time
notifications to Navy
vessels of large whale
aggregations (four or more
whales) within 1 nmi (1.9
km) of a Navy vessel in the
area between 32-33 degrees
North and 117.2-119.5
degrees West.
Towed In-Water Devices................. 250 yd (228.6 m;
marine mammals).
Small-, Medium-, and Large-Caliber Non- 200 yd (182.9 m).
Explosive Practice Munitions.
Non-Explosive Missiles and Rockets..... 900 yd (823 m).
Non-Explosive Bombs and Mine Shapes.... 1,000 yd (914.4 m).
------------------------------------------------------------------------
Note: lb: pounds; nmi: nautical miles; yd: yards; m: meters.
\1\ Underway vessels will maintain at least one Lookout. For ship
classes required to maintain more than one Lookout, the specific
requirement is subject to change over time in accordance with Navy
navigation instruction (e.g., the Surface Ship NAVDORM). Navy
personnel will notify NMFS as soon as practicable should its Lookout
policies change, including in the NAVDORM.

Table 9--Summary of Mitigation Areas for Marine Mammals
------------------------------------------------------------------------
Summary of mitigation area requirements
-------------------------------------------------------------------------
Hawaii Island Mitigation Area (year-round):
Navy personnel must not conduct more than 300 hours of MF1
surface ship hull-mounted mid-frequency active sonar or 20 hours of
MF4 dipping sonar, or use explosives that could potentially result
in takes of marine mammals during training and testing.\1\
4-Islands Region Mitigation Area (November 15-April 15 for active sonar;
year-round for explosives):
Navy personnel must not use MF1 surface ship hull-mounted
mid-frequency active sonar or explosives that could potentially
result in takes of marine mammals during training and testing.\1\
Humpback Whale Special Reporting Areas (December 15-April 15):
Navy personnel must report the total hours of surface ship
hull-mounted mid-frequency active sonar used in the special
reporting areas in its annual training and testing activity reports
submitted to NMFS.
San Diego Arc, San Nicolas Island, and Santa Monica/Long Beach
Mitigation Areas (June 1-October 31):
Navy personnel must not conduct more than a total of 200
hours of MF1 surface ship hull-mounted mid-frequency active sonar
in the combined areas, excluding normal maintenance and systems
checks, during training and testing.\1\
Within the San Diego Arc Mitigation Area, Navy personnel
must not use explosives that could potentially result in the take
of marine mammals during large-caliber gunnery, torpedo, bombing,
and missile (including 2.75'' rockets) activities during training
and testing.\1\
Within the San Nicolas Island Mitigation Area, Navy
personnel must not use explosives that could potentially result in
the take of marine mammals during mine warfare, large-caliber
gunnery, torpedo, bombing, and missile (including 2.75'' rockets)
activities during training.\1\
Within the Santa Monica/Long Beach Mitigation Area, Navy
personnel must not use explosives that could potentially result in
the take of marine mammals during mine warfare, large-caliber
gunnery, torpedo, bombing, and missile (including 2.75'' rockets)
activities during training and testing.\1\
Santa Barbara Island Mitigation Area (year-round):

[[Page 68327]]

Navy personnel must not use MF1 surface ship hull-mounted
mid-frequency active sonar during training and testing, or
explosives that could potentially result in the take of marine
mammals during medium-caliber or large-caliber gunnery, torpedo,
bombing, and missile (including 2.75'' rockets) activities during
training.\1\
Awareness Notification Message Areas (seasonal according to species):
Navy personnel must issue awareness notification messages
to alert ships and aircraft to the possible presence of large
whales during a period based on predicted oceanographic conditions
for a given year. The message must emphasize that when a marine
mammal is spotted, this may be an indicator that additional marine
mammals are present and nearby, and increased vigilance and
awareness of Navy personnel is warranted. Navy personnel must also
issue awareness notification messages to alert ships and aircraft
to the possible presence of gray whales (November-March) and fin
whales (November-May).
------------------------------------------------------------------------
\1\ If Naval units need to conduct more than the specified amount of
training or testing, they will obtain permission from the appropriate
designated Command authority prior to commencement of the activity.
The Navy will provide NMFS with advance notification and include the
information in its annual activity reports submitted to NMFS.

Mitigation Conclusions

NMFS has carefully evaluated the Navy's mitigation measures from
the 2020 rule--many of which were developed with NMFS' input during the
previous phases of Navy training and testing authorizations and none of
which have changed since our evaluation during the 2018 HSTT
rulemaking, with the exception of the changes described herein--and
considered a broad range of other measures (i.e., the measures
considered but eliminated in the 2018 HSTT FEIS/OEIS, which reflect
many of the comments that have arisen via NMFS or public input in past
years) in the context of ensuring that NMFS prescribes the means of
effecting the least practicable adverse impact on the affected marine
mammal species and stocks and their habitat. Our evaluation of
potential measures included consideration of the following factors in
relation to one another: the manner in which, and the degree to which,
the successful implementation of the mitigation measures is expected to
reduce the likelihood and/or magnitude of adverse impacts to marine
mammal species and stocks and their habitat; the proven or likely
efficacy of the measures; and the practicability of the measures for
applicant implementation, including consideration of personnel safety,
practicality of implementation, and impact on the effectiveness of the
military readiness activity. After considering all new information,
including consideration of new information regarding vessel strike,
NMFS proposes two additional mitigation measures and revision of two
existing mitigation measures as described above.
Based on our evaluation of the Navy's current mitigation measures
(which are being implemented under the 2020 HSTT regulations), as well
as modified and new measures described above, NMFS has preliminarily
determined that the proposed mitigation measures are appropriate means
of effecting the least practicable adverse impact on marine mammal
species or stocks and their habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and
considering specifically personnel safety, practicality of
implementation, and impact on the effectiveness of the military
readiness activity. Additionally, as described in more detail below,
the 2020 HSTT final rule includes an adaptive management provision,
which the Navy proposes to extend, which ensures that mitigation is
regularly assessed and provides a mechanism to improve the mitigation,
based on the factors above, through modification as appropriate.
The proposed rule comment period provides the public an opportunity
to submit recommendations, views, and/or concerns regarding the Navy's
activities and the proposed mitigation measures. While NMFS has
preliminarily determined that the proposed mitigation measures would
effect the least practicable adverse impact on the affected species or
stocks and their habitat, NMFS will consider all public comments to
help inform our final decision. Consequently, the proposed mitigation
measures may be refined, modified, removed, or added to prior to the
issuance of the final rule based on public comments received, and where
appropriate, further analysis of any additional mitigation measures.

Proposed Monitoring

Section 101(a)(5)(A) of the MMPA states that in order to authorize
incidental take for an activity, NMFS must set forth requirements
pertaining to the monitoring and reporting of such taking. The MMPA
implementing regulations at 50 CFR 216.104(a)(13) indicate that
requests for incidental take authorizations must include the suggested
means of accomplishing the necessary monitoring and reporting that will
result in increased knowledge of the species and of the level of taking
or impacts on populations of marine mammals that are expected to be
present.
In its 2022 application, the Navy proposes no changes to the
monitoring described in the 2018 HSTT final rule and 2020 HSTT final
rule. They would continue implementation of the robust Integrated
Comprehensive Monitoring Program and Strategic Planning Process
described in the 2018 HSTT final rule. The Navy's monitoring strategy,
currently required by the 2018 HSTT regulations, is well-designed to
work across Navy ranges to help better understand the impacts of the
Navy's activities on marine mammals and their habitat by focusing on
learning more about marine mammal occurrence in different areas and
exposure to Navy stressors, marine mammal responses to different sound
sources, and the consequences of those exposures and responses on
marine mammal populations. Similarly, these proposed modified
regulations would include identical adaptive management provisions and
reporting requirements as the 2018 HSTT regulations. There is no new
information that would indicate that the monitoring measures put in
place under the 2018 HSTT final rule would not remain applicable and
appropriate for the 7-year period of this proposed rule. See the
Monitoring section of the 2018 HSTT final rule for more details on the
monitoring program that would be required under this rule. In addition,
please see the 2019 Navy application, which references Chapter 13 of
the 2017 Navy application for full details on the monitoring and
reporting proposed by the Navy.
Within the SOCAL portion of HSTT, the Navy has been primarily
focused on beaked whale monitoring since 2018 through two separate
ongoing projects that are expected to continue until 2025. These
projects use passive acoustic devices, visual surveys, satellite
tagging, genetic analysis, photoID, and response to anthropogenic
sounds to refine population status of beaked whales in SOCAL. There is
also one concurrent project with fin whales using visual surveys,
satellite tagging, and photoID to gather additional data on fin whale

[[Page 68328]]

populations in Southern California. Finally, the Navy continues to fund
marine mammal sighting data collected during California Cooperative
Oceanic Fisheries Investigations (CALCOFI) https://calcofi.org/. These
data are collected on a much more frequent basis than NMFS' West Coast
visual survey which typically occur once every 5 years in the summer.
CALCOFI surveys occur quarterly every year to include winter and spring
seasons NMFS does not survey. Sufficient marine mammal sightings have
been accumulated since the Navy started funding in 2004 for the data to
be incorporated into ongoing NMFS spatial habitat models, including new
models for select species. The Navy also annually funds continued NMFS
spatial habitat model improvements as new data and techniques become
available. These models benefit the Navy and other Federal partners
such as the Bureau of Ocean Energy Management and NMFS, for use in
future regional marine mammal density derivation. For additional
information, please see the Navy's Marine Species Monitoring program
website, https://www.navymarinespeciesmonitoring.us/regions/pacific/current-projects/.

Adaptive Management

The 2020 HSTT regulations governing the take of marine mammals
incidental to Navy training and testing activities in the HSTT Study
Area contain an adaptive management component. Our understanding of the
effects of Navy training and testing activities (e.g., acoustic and
explosive stressors) on marine mammals continues to evolve, which makes
the inclusion of an adaptive management component both valuable and
necessary within the context of 7-year regulations. The 2022 Navy
application proposes no changes to the adaptive management component
included in the 2020 HSTT final rule.
The reporting requirements associated with this rule are designed
to provide NMFS with monitoring data from the previous year to allow
NMFS to consider whether any changes to existing mitigation and
monitoring requirements are appropriate. The use of adaptive management
allows NMFS to consider new information from different sources to
determine (with input from the Navy regarding practicability) on an
annual or biennial basis if mitigation or monitoring measures should be
modified (including additions or deletions). Mitigation measures could
be modified if new data suggests that such modifications would have a
reasonable likelihood of more effectively accomplishing the goals of
the mitigation and monitoring and if the measures are practicable. If
the modifications to the mitigation, monitoring, or reporting measures
are substantial, NMFS will publish a notice of the planned LOA in the
Federal Register and solicit public comment.
The following are some of the possible sources of applicable data
to be considered through the adaptive management process: (1) results
from monitoring and exercises reports, as required by MMPA
authorizations; (2) compiled results of Navy funded R&D studies; (3)
results from specific stranding investigations; (4) results from
general marine mammal and sound research; and (5) any information which
reveals that marine mammals may have been taken in a manner, extent, or
number not authorized by these regulations or subsequent LOAs. The
results from monitoring reports and other studies may be viewed at
https://www.navymarinespeciesmonitoring.us.

Proposed Reporting

In order to issue incidental take authorization for an activity,
section 101(a)(5)(A) of the MMPA states that NMFS must set forth
requirements pertaining to the monitoring and reporting of such taking.
Effective reporting is critical both to compliance as well as ensuring
that the most value is obtained from the required monitoring. Reports
from individual monitoring events, results of analyses, publications,
and periodic progress reports for specific monitoring projects will be
posted to the Navy's Marine Species Monitoring web portal: https://www.navymarinespeciesmonitoring.us. The 2019 Navy application and 2022
Navy application proposed no changes to the reporting requirements,
though as noted above, the Navy has since proposed to report changes to
Lookout SOPs to NMFS. Except as discussed below, reporting requirements
would remain identical to those described in the 2018 HSTT final rule
and 2020 HSTT final rule, and there is no new information that would
indicate that the reporting requirements put in place under the 2020
HSTT final rule would not remain applicable and appropriate for the
remaining duration of the 7-year period of this proposed rule. See the
Reporting section of the 2018 HSTT final rule for more details on the
reporting that would be required under this rulemaking. In addition,
the 2018 HSTT proposed and final rules unintentionally failed to
include the requirement for the Navy to submit a final activity ``close
out'' report at the end of the regulatory period. That oversight was
corrected through the 2020 HSTT final rule. Please see the 2020 HSTT
final rule for the detailed requirements for that report.
In addition to the reporting requirements included in the 2020 HSTT
final rule, the Navy must report changes in its Lookout policies to
NMFS as soon as practicable after a change is made.

Preliminary Analysis and Negligible Impact Determination

NMFS has defined negligible impact as an impact resulting from the
specified activity that cannot be reasonably expected to, and is not
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). While this proposed rule consists of a modification of
take by M/SI by vessel strike, NMFS considers the impacts of the entire
specified activity and the total taking in the negligible impact
determination. An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
taken through mortality, serious injury, and Level A or Level B
harassment (as presented in tables 11 and 12 of the 2020 HSTT final
rule), NMFS considers other factors, such as the likely nature of any
responses (e.g., intensity, duration), the context of any responses
(e.g., critical reproductive time or location, migration), as well as
effects on habitat, and the likely effectiveness of the mitigation. We
also assess the number, intensity, and context of estimated takes by
evaluating this information relative to population status. Consistent
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338;
September 29, 1989), the impacts from other past and ongoing
anthropogenic activities (including foreign military activities) are
incorporated into this analysis via their impacts on the environmental
baseline (e.g., as reflected in the regulatory status of the species,
population size and growth rate where known, other ongoing sources of
human-caused mortality, ambient noise levels, and specific
consideration of take by Level A harassment or M/SI previously
authorized for other NMFS activities).
In the Estimated Take of Marine Mammals sections of this proposed
rule and the 2020 HSTT final rule (where the activities, species and
stocks, potential effects, and mitigation measures are the same as for
this rulemaking), we

[[Page 68329]]

identified the subset of potential effects that would be expected to
rise to the level of takes both annually and over the 7-year period
covered by this rulemaking and then identified the number of each of
those mortality takes that we believe could occur or the maximum number
of harassment takes that are reasonably expected to occur based on the
methods described. The impact that any given take will have is
dependent on many case-specific factors that need to be considered in
the negligible impact analysis (e.g., the context of behavioral
exposures such as duration or intensity of a disturbance, the health of
impacted animals, the status of a species that incurs fitness-level
impacts to individuals, etc.). For this proposed rule, we evaluated the
likely impacts of the enumerated maximum number of harassment takes
that are reasonably expected to occur and proposed for authorization,
in the context of the specific circumstances surrounding these
predicted takes. We also assessed M/SI takes that could occur, as well
as considering the traits and statuses of the affected species and
stocks. Last, we collectively evaluated this information, as well as
other more taxa-specific information and mitigation measure
effectiveness, in group-specific assessments that support our
negligible impact conclusions for each stock or species. Because all of
the Navy's specified activities would occur within the ranges of the
marine mammal stocks identified in the rule, all negligible impact
analyses and determinations are at the stock level (i.e., additional
species-level determinations are not needed).
The Navy proposes no changes to the nature or level of the
specified activities or the boundaries of the HSTT Study Area, and
therefore, the training and testing activities (e.g., equipment and
sources used, exercises conducted) are the same as those analyzed in
the 2020 HSTT final rule. In addition, the mitigation, monitoring, and
nearly all reporting measures are identical to those described and
analyzed in the 2018 HSTT final rule with the exception of changes to
mitigation measures described previously and the additional reporting
requirement for Navy to report changes in its Lookout policies to NMFS
as soon as practicable after a change is made. There is no new
information since the publication of the 2020 HSTT final rule regarding
the impacts of the specified activities on marine mammals, the status
and distribution of any of the affected marine mammal species or
stocks, or the effectiveness of the mitigation and monitoring measures
that would change the content of our analyses, with the exception of
that described below. First, naval vessel strikes have occurred in the
HSTT and Atlantic Fleet Training and Testing (AFTT) Study Areas since
publication of the 2020 HSTT final rule (one fin or sei whale struck by
the U.S. Navy in the HSTT Study Area (2023), two unidentified large
whales struck by the U.S. Navy in the HSTT Study Area (2021), two fin
whales struck by a foreign navy in the HSTT Study Area (2021), and one
dolphin struck by the U.S. Navy in the AFTT Study Area (2021)). Second,
for gray whales, we have considered the latest effects of the UME on
the west coast of North America along with the effects of the Navy's
activities in the negligible impact analysis. Third, a new study
suggests that Lookout detection of marine mammals is less certain than
previously assumed (Oedekoven and Thomas, 2022). Fourth, stock
assessments have been updated for multiple stocks in the 2022 Pacific
and Alaska SARs (Carretta et al. 2023; Young et al. 2023).
As described above and in the 2022 Navy application, a number of
additional studies have been published, including several studies
associated with TTS in harbor porpoises and seals (e.g., Kastelein et
al. 2020d; Kastelein et al. 2021a and 2021b; Sills et al. 2020). NMFS
is aware of these recent papers and is currently working with the Navy
to update NMFS' Technical Guidance for Assessing the Effects of
Anthropogenic Sound on Marine Mammal Hearing Version 2.0 (Acoustic
Technical Guidance; NMFS 2018) to reflect relevant papers that have
been published since the 2018 update on our 3-5 year update schedule in
the Acoustic Technical Guidance. We note that the recent peer-reviewed,
updated marine mammal noise exposure criteria by Southall et al. (2019)
provide identical PTS and TTS thresholds and weighting functions to
those provided in NMFS' Acoustic Technical Guidance. NMFS will continue
to review and evaluate new relevant data as it becomes available and
consider the impacts of those studies on the Acoustic Technical
Guidance to determine what revisions/updates may be appropriate.
However, any such revisions must undergo peer and public review before
being adopted, as described in the Acoustic Guidance methodology. While
some of the relevant data may potentially suggest changes to TTS/PTS
thresholds for some species, any such changes would not be expected to
change the predicted take estimates in a manner that would change the
necessary determinations supporting the issuance of these regulations,
and the data and values used in this rulemaking reflect the best
available science.

Harassment

As described in the Estimated Takes of Marine Mammals section, the
annual number of takes proposed for authorization and reasonably
expected to occur by Level A harassment and Level B harassment (based
on the maximum number of activities per 12-month period) are identical
to those presented in tables 41 and 42 in the Take Requests section of
the 2018 HSTT final rule, with the exception of humpback whale, which
are presented in tables 2 and 3 herein. As such, the negligible impact
analyses and determinations of the effects of the estimated Level A
harassment and Level B harassment takes on annual rates of recruitment
or survival for each species and stock are nearly identical to and
substantively unchanged from those presented in the 2020 HSTT final
rule. The differences in the analysis is our removal of consideration
of California Sea Lion UME, which has been closed since publication of
the 2020 HSTT final rule, and incorporation of the revised stock
structure for humpback whales. This does not affect the results of the
analyses or our determinations. For detailed discussion of the impacts
that affected individuals may experience given the specific
characteristics of the specified activities and required mitigation
(e.g., from behavioral disruption, masking, and temporary or permanent
threshold shift), along with the effects of the expected Level A
harassment and Level B harassment take on reproduction and survival,
see the applicable subsections in the Analysis and Negligible Impact
Determination section of the 2018 HSTT final rule (83 FR 66977-67018;
also incorporated by reference in the 2020 HSTT final rule).

Serious Injury or Mortality

Based on the information and methods discussed in the Estimated
Take of Marine Mammals section (which are identical to those used in
the 2018 HSTT final rule for explosives and revised for vessel strike),
NMFS is proposing to authorize five mortalities of large whales due to
vessel strike over the 7-year period of this rulemaking, two more
strikes than what was authorized in the 2018 HSTT final rule and 2020
HSTT final rule. Across the 7-year duration of the rule, take of an
annual average of 0.57 gray whales (Eastern North Pacific stock) and
fin

[[Page 68330]]

whales (CA/OR/WA stock), an annual average of 0.29 humpback whales
(Hawaii stock) and an annual average of 0.14 blue whales (Eastern North
Pacific stock), sei whales (Eastern North Pacific stock) and humpback
whales (Mainland Mexico-CA/OR/WA stock, Mexico DPS), as described in
table 8 (i.e., one, two, or four take(s) over 7 years divided by seven
to get the annual number) could occur and are proposed for
authorization.

Table 10--Summary Information Related to Mortalities Requested for Vessel Strike
[2018-2025]
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Annual
authorized Residual
Stock take by Total Fisheries interactions Annual rate of M/SI Potential PBR (PBR Recent UME (Y/N);
Species (stock) abundance serious annual M/ (Y/N); annual rate of M/ from vessel collision biological minus Stock trend * \4\ number and year (since
(Nbest) * injury or SI * \2\ SI from fisheries * removal annual M/ 2007)
mortality interactions * (PBR) * SI) \3\
\1\
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Fin whale (CA/OR/WA stock)......... 11,065 0.57 >=43.6 Y; >=0.64............... Y, 43................. 80 36.4 [uarr]................ N.
Gray whale (Eastern North Pacific 26,960 0.57 131 Y, 9.3.................. Y, 1.8................ 801 670 \5\ [uarr]............ Y; 674; 2019 (as of
stock). June 25, 2023).
Humpback whale (Mainland Mexico-CA/ 3,477 0.14 22 Y; 11.4................. Y, 10.15.............. 65 \6\ 43 Unknown............... N.
OR/WA stock, Mexico DPS).
Humpback whale (Hawaii stock)...... 11,278 0.29 27.09 Y; 8.39................. \7\ Y, 10.59.......... 127 99.91 Unknown............... Y; 2015; 52.]
Blue whale (Eastern North Pacific 1,898 0.14 >=19.5 Y; >=1.54............... Y, 0.8................ 4.1 -15.4 Unknown............... Y; 3, 2007.
Stock).
Sei whale (Eastern North Pacific 519 0.14 >=0.2 N; 0.................... Y, 0.2................ 0.75 0.55 Unknown............... N.
Stock).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Presented in the 2022 final SARs.
\1\ This column represents the annual take by serious injury or mortality (M/SI) by vessel collision and was calculated by the number of mortalities proposed for authorization divided by 7
years (the length of the rule and LOAs).
\2\ This column represents the total number of incidents of M/SI that could potentially accrue to the specified species or stock. This number comes from the SAR, but deducts the takes accrued
from either Navy strikes or NMFS' Southwest Fisheries Science Center (SWFSC) takes in the SARs to ensure not double-counted against PBR. However, for these species, there were no takes from
either other Navy activities or SWFSC in the SARs to deduct that would be considered double-counting.
\3\ This value represents the calculated PBR less the average annual estimate of ongoing anthropogenic mortalities (i.e., total annual human-caused M/SI, which is presented in the SARs).
\4\ See relevant SARs for more information regarding stock status and trends.
\5\ The Pacific 2022 SAR indicates that the stock trend is increasing. However, recent (2021-2022) surveys conducted by NMFS' Southwest Fisheries Science Center estimated that the population
has declined to 16,650 whales, though the authors note that this stock has historically shown a pattern of population growth and decline that has not impacted the population in the long term
(Eguchi et al. 2022).
\6\ Vessel strike of the Mainland Mexico-CA/OR/WA stock was calculated by applying a prorated portion of humpback whale strikes modeled by Rockwood et al. (2017) to this stock.
\7\ For this stock, PBR is currently set at 43 for U.S. waters and 65 for the stock's entire range. As the HSTT Study Area extends beyond U.S. waters and activities have the potential to
impact the entire stock, we present the analysis using the PBR for the stock's entire range.
\8\ Annual vessel strike for this stock reported in the 2022 final SAR was calculated by summing vessel strike data from Hawaii, Alaska, and Washington. All observed strikes in Hawaii were
assigned to the Hawaii stock, and a portion of observed strikes in Alaska were assigned to the Hawaii stock. Vessel strike of the Hawaii stock in Washington waters was calculated by applying
a prorated portion of humpback whale strikes modeled by Rockwood et al. (2017) to the Hawaii stock.

The Navy also requested a small number of takes by M/SI from
explosives in the 2017 Navy application. To calculate the annual
average of mortalities for explosives in table 11, we used the same
method as described for vessel strikes. The annual average is the total
number of takes over 7 years divided by seven. Specifically, NMFS is
proposing to authorize the following M/SI takes from explosives: five
California sea lions and eight short-beaked common dolphins over the 7-
year period (therefore 0.71 mortalities annually for California sea
lions and 1.14 mortalities annually for short-beaked common dolphin),
as described in table 11. As this annual number is the same as that
analyzed and authorized in the 2020 HSTT final rule, and no other
relevant information about the status, abundance, or effects of
mortality on each species or stock has changed, the analysis of the
effects of explosives is identical to that presented in the 2020 HSTT
final rule.

Table 11--Summary Information Related to Mortalities From Explosives
[2018-2025]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Annual
authorized Fisheries SWFSC Residual
Stock take by Total interactions (Y/N); authorized PBR--PBR UME (Y/N);
Species (stock) abundance serious annual M/ annual rate of M/SI PBR * take minus Stock number and
(Nbest) * injury or SI* \2\ from fisheries (annual) annual M/SI trend* \5\ year
mortality interactions * \3\ and SWFSC
\1\ \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion (U.S. 257,606 0.71 >=321 Y; >=197............ 14,011 6 13,684 [uarr] N
stock).
Short-beaked common dolphin (CA/ 1,056,308 1.14 >=30.5 Y; >=30.5........... 8,889 2.8 8,855.7 ? N
OR/WA stock).
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Presented in the 2022 draft SARs or most recent SAR.
\1\ This column represents the annual take by serious injury or mortality (M/SI) during explosive detonations and was calculated by the number of
mortalities planned for authorization divided by 7 years (the length of the rule and LOAs).
\2\ This column represents the total number of incidents of M/SI that could potentially accrue to the specified species or stock. This number comes from
the SAR.
\3\ This column represents annual take authorized through NMFS' SWFSC rulemaking/LOAs (86 FR 3840; January 15, 2021).
\4\ This value represents the calculated PBR less the average annual estimate of ongoing anthropogenic mortalities (i.e., total annual human-caused M/SI
column and the annual authorized take from the SWFSC column. In the case of California sea lion the M/SI column (321) and the annual authorized take
from the SWFSC (6) were subtracted from the calculated PBR of 14,011. In the case of short-beaked common dolphin the M/SI column (30.5) and the annual
authorized take from the SWFSC (2.8) were subtracted from the calculated PBR of 8,889.
\5\ See relevant SARs for more information regarding stock status and trends.

[[Page 68331]]

See the Serious Injury or Mortality subsection in the Analysis and
Negligible Impact Determination section of the 2018 HSTT final rule (83
FR 66985-66993) for detailed discussions of the impacts of M/SI,
including a description of how the agency uses the PBR metric and other
factors to inform our analysis and an analysis of the impacts on each
species and stock for which M/SI is proposed for authorization,
including the relationship of potential mortality for each species to
the insignificance threshold and residual PBR, except as updated below.

Stocks With M/SI Below the Insignificance Threshold

As noted in the Serious Injury or Mortality subsection of the
Negligible Impact Analysis and Determination section in the 2018 HSTT
final rule and 2020 HSTT final rule, for a species or stock with
incidental M/SI less than 10 percent of residual PBR, we consider M/SI
from the specified activities to represent an insignificant incremental
increase in ongoing anthropogenic M/SI that alone (i.e., in the absence
of any other take and barring any other unusual circumstances) will
clearly not adversely affect annual rates of recruitment and survival.
In this case, as shown in table 10 and table 11, the following species
or stocks have potential or estimated M/SI from vessel strike and
explosive takes, respectively, and proposed for authorization below
their insignificance threshold: fin whale (CA/OR/WA stock), gray whale
(Eastern North Pacific stock), humpback whale (Hawaii stock and
Mainland Mexico-CA/OR/WA stock), California sea lion (U.S stock), and
short-beaked common dolphin (CA/OR/WA stock). While the proposed
authorized M/SI of gray whales (Eastern North Pacific stock) is below
the insignificance threshold, because of the recent UME, we further
address how the proposed authorized M/SI and the UME inform the
negligible impact determination immediately below. For the other four
stocks with proposed authorized M/SI below the insignificance
threshold, there are no other known factors, information, or unusual
circumstances that indicate anticipated M/SI below the insignificance
threshold could have adverse effects on annual rates of recruitment or
survival and they are not discussed further. For the remaining stocks
with anticipated potential M/SI above the insignificance threshold, how
that M/SI compares to residual PBR, as well as additional factors, as
appropriate, are discussed below as well.

Gray Whales (Eastern North Pacific Stock)

Since January 2019, gray whale strandings along the west coast of
North America have been significantly higher than the previous 18-year
averages. Preliminary findings from necropsies have shown evidence of
emaciation. These findings are not consistent across all of the whales
examined, so more research is needed. The seasonal pattern of elevated
strandings in the spring and summer months is similar to that of the
previous gray whale UME in 1999-2000. If strandings continue to follow
a similar pattern, we would anticipate a decrease in strandings in late
summer and fall. However, combined with other annual human-caused
mortalities and viewed through the PBR lens (for human-caused
mortalities), total human-caused mortality would still fall below
residual PBR. Given the small number of takes by serious injury or
mortality proposed for authorization, the proposed takes are not
anticipated to exacerbate the ongoing UME.

Stocks With M/SI Above the Insignificance Threshold

Blue Whale (Eastern North Pacific Stock)

For blue whales (Eastern North Pacific stock), PBR is currently set
at 4.1 and the total annual M/SI is estimated at greater than or equal
to 19.5, yielding a residual PBR of -15.4. This is slightly higher than
the 2020 HSTT final rule (was -16.7). NMFS proposes to authorize one M/
SI for the Navy over the 7-year duration of the rule (indicated as 0.14
annually for the purposes of comparing to PBR and evaluating overall
effects on annual rates of recruitment and survival), which means that
residual PBR is exceeded by 15.54. However, as described in the 2018
and 2020 rules, given that the negligible impact determination is based
on the assessment of take of the activity being analyzed, when total
annual mortality from human activities is higher, but the impacts from
the specific activity being analyzed are very small, NMFS may still
find the impact of the proposed authorized take from a specified
activity to be negligible even if total human-caused mortality exceeds
PBR if the proposed authorized mortality is less than 10 percent of PBR
and management measures are being taken to address serious injuries and
mortalities from the other activities causing mortality (i.e., other
than the specified activities covered by the incidental take
authorization in consideration). When those considerations are applied
here, the authorized lethal take (0.14 annually) of blue whales from
the Eastern North Pacific stock is less than 10 percent of PBR (which
is 4.1), and there are management measures in place to address M/SI
from activities other than those the Navy is conducting (as discussed
below). Perhaps more importantly, the available data suggests that the
current number of vessel strikes is not likely to have an adverse
impact on the population, despite the fact that it exceeds PBR, with
the Navy's minimal additional mortality of one whale in the 7 years not
creating the likelihood of adverse impact. Immediately below, we
explain the information that supports our finding that the Navy's
proposed authorized M/SI is not expected to result in more than a
negligible impact on this stock. As described previously, NMFS must
also ensure that impacts by the applicant on the species or stock from
other types of take (i.e., harassment) do not combine with the impacts
from mortality to adversely affect the species or stock via impacts on
annual rates of recruitment or survival, which occurs further below in
the stock-specific conclusion sections.
As discussed in the 2018 HSTT final rule and the 2020 HSTT final
rule, the 2018 draft SAR and the more recent SARs rely on a new method
to estimate annual deaths by vessel strike utilizing an encounter
theory model that combined species distribution models of whale
density, vessel traffic characteristics, and whale movement patterns
obtained from satellite-tagged animals in the region to estimate
encounters that would result in mortality (Rockwood et al. 2017). The
model predicts 18 annual mortalities of blue whales from vessel
strikes, which, with the additional M/SI of 1.54 from fisheries
interactions, results in the current estimate of residual PBR being -
15.4. Although NMFS' Permits and Conservation Division in the Office of
Protected Resources has independently reviewed the vessel strike model
and its results and agrees that it is appropriate for estimating blue
whale mortality by vessel strike on the U.S. West Coast, for analytical
purposes we also note that if the historical method were used to
predict vessel strike (i.e., using observed mortality by vessel strike,
or 0.8, instead of 18), then total human-caused mortality including the
Navy's potential take would not exceed PBR. We further note that the
authors (Rockwood et al. 2017) do not suggest that vessel strike
suddenly increased to 18 recently. In fact, the model is not specific
to a year, but rather offers a generalized

[[Page 68332]]

prediction of vessel strike off the U.S. West Coast. Therefore, if the
Rockwood et al. (2017) model is an accurate representation of vessel
strike, then similar levels of vessel strike have been occurring in
past years as well. Put another way, if the model is correct, for some
number of years total-human-caused mortality has been significantly
underestimated and PBR has been similarly exceeded by a notable amount,
and yet, the Eastern North Pacific stock of blue whales remains stable
nevertheless.
NMFS' 2022 final SAR states that the current population trend is
unknown, though there may be evidence of a population size increase
since the 1990s. The SAR further cites to Monnahan et al. (2015), which
used a population dynamics model to estimate that the Eastern North
Pacific blue whale population was at 97 percent of carrying capacity in
2013 and to suggest that the observed lack of a population increase
since the early 1990s was explained by density dependence, not impacts
from vessel strike. This would mean that this stock of blue whales
shows signs of stability and is not increasing in population size
because the population size is at or nearing carrying capacity for its
available habitat. In fact, we note that this population has maintained
this status throughout the years that the Navy has consistently tested
and trained at similar levels (with similar vessel traffic) in areas
that overlap with blue whale occurrence, which would be another
indicator of population stability.
Monnahan et al. (2015) modeled vessel numbers, vessel strikes, and
the population of the Eastern North Pacific blue whale population from
1905 out to 2050 using a Bayesian framework to incorporate informative
biological information and assign probability distributions to
parameters and derived quantities of interest. The authors tested
multiple scenarios with differing assumptions, incorporated
uncertainty, and further tested the sensitivity of multiple variables.
Their results indicated that there is no immediate threat (i.e.,
through 2050) to the population from any of the scenarios tested, which
included models with 10 and 35 strike mortalities per year. Broadly,
the authors concluded that, unlike other blue whale stocks, the Eastern
North Pacific blue whales have recovered from 70 years of whaling and
are in no immediate threat from vessel strikes. They further noted that
their conclusion conflicts with the depleted and strategic designation
under the MMPA as well as PBR specifically.
As discussed, we also take into consideration management measures
in place to address M/SI caused by other activities. The Channel
Islands NMS staff coordinates, collects, and monitors whale sightings
in and around the Vessel Speed Reduction (VSR) zones and the Channel
Islands NMS region. Redfern et al. (2013) note that the most risky area
for blue whales is the Santa Barbara Channel, where shipping lanes
intersect with common feeding areas. The seasonally established
Southern California VSR zone spans from Point Arguello to Dana Point,
including the Traffic Separation Schemes in the Santa Barbara Channel
and San Pedro Channel. Vessels transiting the area from May 1 through
December 15, 2023 are recommended to exercise caution and voluntarily
reduce speed to 10 kn (18.5 km per hour) or less for blue, humpback,
and fin whales. (Note this is an expanded timeframe from the Whale
Advisory Zone discussed in the 2020 HSTT final rule, which spanned June
through November, though the effective period could change in future
years.) Channel Island NMS observers collect information from aerial
surveys conducted by NOAA, the U.S. Coast Guard, California Department
of Fish and Game, and U.S. Navy chartered aircraft. Information on
seasonal presence, movement, and general distribution patterns of large
whales is shared with mariners, NMFS Office of Protected Resources,
U.S. Coast Guard, California Department of Fish and Game, the Santa
Barbara Museum of Natural History, the Marine Exchange of Southern
California, and whale scientists. Real time and historical whale
observation data collected from multiple sources can be viewed on the
Point Blue Whale Database.
In this case, 0.14 M/SI means one mortality in 1 of the 7 years and
zero mortalities in 6 of those 7 years. Therefore, the Navy would not
be contributing to the total human-caused mortality at all in 6 of the
7, or 85.7 percent, of the years covered by this rulemaking. That means
that even if a blue whale were to be struck, in 6 of the 7 years there
could be no effect on annual rates of recruitment or survival from
Navy-caused M/SI. Additionally, the loss of a male would have far less,
if any, effect on population rates and absent any information
suggesting that one sex is more likely to be struck than another, we
can reasonably assume that there is a 50 percent chance that the single
strike authorized by this rulemaking would be a male, thereby further
decreasing the likelihood of impacts on the population rate. In
situations like this where potential M/SI is fractional, consideration
must be given to the lessened impacts anticipated due to the absence of
M/SI in 6 of the 7 years and the fact that the single strike could be a
male. Lastly, we reiterate that PBR is a conservative metric and also
not sufficiently precise to serve as an absolute predictor of
population effects upon which mortality caps would appropriately be
based. This is especially important given the minor difference between
zero and one across the 7-year period covered by this rulemaking, which
is the smallest distinction possible when considering mortality. As
noted above, Wade et al. (1998), authors of the paper from which the
current PBR equation is derived, note that ``Estimating incidental
mortality in 1 year to be greater than the PBR calculated from a single
abundance survey does not prove the mortality will lead to depletion;
it identifies a population worthy of careful future monitoring and
possibly indicates that mortality-mitigation efforts should be
initiated.'' The information included here indicates that the current
population trend of this blue whale stock is unknown but likely
approaching carrying capacity and has leveled off because of density-
dependence, not human-caused mortality, in spite of what might be
otherwise indicated from the calculated PBR. Further, potential (and
proposed for authorization) M/SI is below 10 percent of PBR and
management actions are in place to minimize vessel strike from other
vessel activity in one of the highest-risk areas for strikes. Based on
the presence of the factors described above, we do not expect lethal
take from Navy activities, alone, to adversely affect Eastern North
Pacific blue whales through effects on annual rates of recruitment or
survival. Nonetheless, the fact that total human-caused mortality
exceeds PBR necessitates close attention to the remainder of the
impacts (i.e., harassment) on the Eastern North Pacific stock of blue
whales from the Navy's activities to ensure that the total authorized
takes have a negligible impact on the species or stock. Therefore, this
information will be considered in combination with our assessment of
the impacts of proposed harassment takes in the Group and Species-
Specific Analyses section that follows.

Sei Whale (Eastern North Pacific Stock)

For sei whales (Eastern North Pacific stock), PBR is currently set
at 0.75. The total annual M/SI is estimated at greater than or equal to
0.2 in the 2022 final SAR, which reflects one strike over 5

[[Page 68333]]

years, yielding a residual PBR of 0.55. However, more recent
information suggests that the total annual M/SI reflected in the SAR
may be overestimated because the one mortality considered in the
calculation may not have been caused by a vessel strike. Carretta et
al. (2021) elected to omit this strike from its report summarizing
sources of human-related injury and mortality for U.S. Pacific west
coast marine mammal stock assessments after reviewing the stranding
narrative. The narrative indicated that the strike likely occurred
post-mortem, evidenced by a lack of hemorrhaging in the whale's
tissues. NMFS proposes to authorize one M/SI for the Navy over the 7-
year duration of the rule (indicated as 0.14 annually for the purposes
of comparing to PBR and evaluating overall effects on annual rates of
recruitment and survival), which means that residual PBR is 0.41 with
the conservative inclusion of the likely post-mortem strike discussed
above.
We acknowledge that the 2023 vessel strike by the U.S. Navy could
have been of a sei whale or a CA/OR/WA fin whale, and this strike is
not quantitatively included in this PBR analysis (nor is it
quantitatively included in the PBR analysis for CA/OR/WA fin whale if
both of the 2021 U.S. Navy strikes were fin whales) which rely on the
2022 final SARs. However, consideration of the 2023 strike would not
change the total M/SI which NMFS compares to PBR, as the single strike
from 2012-2016 used to calculate the vessel strike rate in the 2022
final SAR occurred in 2015 (which, as noted above, likely occurred
post-mortem, and therefore, inclusion of this strike in the annual
total M/SI is inherently conservative), and the 2023 U.S. Navy strike
occurred outside of the 2012-2016 time period. Therefore, while we
acknowledge the 2023 U.S. Navy strike, in the quantitative analysis it
is treated the same as other non-U.S. Navy strikes that occurred
outside of the timeframe reflected in the total M/SI (2012-2016).
Immediately below, we explain the information that supports our
finding that the Navy's proposed authorized M/SI is not expected to
result in more than a negligible impact on this stock. As described
previously, NMFS must also ensure that impacts by the applicant on the
species or stock from other types of take (i.e., harassment) do not
combine with the impacts from mortality to adversely affect the species
or stock via impacts on annual rates of recruitment or survival, which
occurs further below in the stock-specific conclusion sections.
Of note, management measures are in place to address M/SI caused by
other activities. The Channel Islands NMS staff coordinates, collects,
and monitors whale sightings in and around the Vessel Speed Reduction
(VSR) zones and the Channel Islands NMS region. The seasonally
established Southern California VSR zone spans from Point Arguello to
Dana Point, including the Traffic Separation Schemes in the Santa
Barbara Channel and San Pedro Channel. Vessels transiting the area from
May 1 through December 15, 2023 are recommended to exercise caution and
voluntarily reduce speed to 10 kn (18.5 km per hour) or less. While the
VSR zone is aimed at reducing risk of fatal vessel strike of blue,
humpback, and fin whales, this measure is also anticipated to reduce
risk to sei whales (note, this is an expanded timeframe from the Whale
Advisory Zone discussed in the 2020 HSTT final rule, which spanned June
through November, though the effective period could change in future
years). Channel Island NMS observers collect information from aerial
surveys conducted by NOAA, the U.S. Coast Guard, California Department
of Fish and Game, and U.S. Navy chartered aircraft. Information on
seasonal presence, movement, and general distribution patterns of large
whales is shared with mariners, NMFS Office of Protected Resources,
U.S. Coast Guard, California Department of Fish and Game, the Santa
Barbara Museum of Natural History, the Marine Exchange of Southern
California, and whale scientists. Real time and historical whale
observation data collected from multiple sources can be viewed on the
Point Blue Whale Database.
Further, as stated in the 2022 final SAR, the California swordfish
drift gillnet fishery is the most likely U.S. fishery to interact with
Eastern North Pacific sei whales, though there are zero estimated
annual takes from this fishery given no observed entanglements from
1990-2016 across 8,845 monitored fishing sets (Carretta et al.
(2018b)). NMFS established the Pacific Offshore Cetacean Take Reduction
Team in 1996 and prepared an associated Plan (PCTRP) to reduce the risk
of M/SI via fisheries interactions. In 1997, NMFS published final
regulations formalizing the requirements of the PCTRP, including the
use of pingers following several specific provisions and the employment
of Skipper education workshops.
In this case, 0.14 M/SI means one authorized mortality in 1 of the
7 years and zero authorized mortalities in 6 of those 7 years.
Therefore, the Navy's authorized take would not be contributing to the
total human-caused mortality at all in 6 of the 7, or 85.7 percent, of
the years covered by this rulemaking. That means that even if a sei
whale were to be struck, in 6 of the 7 years there could be no effect
on annual rates of recruitment or survival from Navy-caused M/SI.
Additionally, the loss of a male would have far less, if any, effect on
population rates and absent any information suggesting that one sex is
more likely to be struck than another, we can reasonably assume that
there is a 50 percent chance that the single strike authorized by this
rulemaking would be a male, thereby further decreasing the likelihood
of impacts on the population rate. In situations like this where
potential M/SI is fractional, consideration must be given to the
lessened impacts anticipated due to the absence of M/SI in 6 of the 7
years and the fact that the single strike could be a male.
Lastly, we reiterate that PBR is a conservative metric and also not
sufficiently precise to serve as an absolute predictor of population
effects upon which mortality caps would appropriately be based. This is
especially important given the minor difference between zero and one
across the 7-year period covered by this rulemaking, which is the
smallest distinction possible when considering mortality. As noted
above, Wade et al. (1998), authors of the paper from which the current
PBR equation is derived, note that ``Estimating incidental mortality in
1 year to be greater than the PBR calculated from a single abundance
survey does not prove the mortality will lead to depletion; it
identifies a population worthy of careful future monitoring and
possibly indicates that mortality-mitigation efforts should be
initiated.'' Even after qualitatively considering the possibility that
the whale struck by Navy in 2023 was a sei whale, and based on the
presence of the factors described above, we do not expect one
authorized lethal take from Navy activities, alone, to adversely affect
Eastern North Pacific sei whales through effects on annual rates of
recruitment or survival. This information will be considered in
combination with our assessment of the impacts of proposed harassment
takes in the Group and Species-Specific Analyses section that follows.

Group and Species-Specific Analyses

In addition to broader analyses of the impacts of the Navy's
activities on mysticetes, odontocetes, and pinnipeds, the 2018 HSTT
final rule contained detailed analyses of the effects of the

[[Page 68334]]

Navy's activities in the HSTT Study Area on each affected species and
stock and was updated, as appropriate, in the 2020 HSTT final rule. All
of that information and analyses remain applicable and valid for our
analyses of the effects of the same Navy activities on the same species
and stocks, with the exception of humpback whale, for which the stock
structure has been revised, and NMFS has updated its analyses
accordingly for this proposed rule. See the Group and Species-Specific
Analyses subsection in the Analysis and Negligible Impact Determination
section of the 2018 HSTT final rule (83 FR 66993-67018). In addition,
apart from the additional proposed incidental take by vessel strike of
two large whales, the resulting changes to the average annual mortality
estimates discussed above, and the revised humpback whale stock
structure, no new information has been received since the publication
of the 2020 HSTT final rule that significantly changes the analyses of
the effects of the Navy's activities on each species and stock
presented in the 2020 HSTT final rule (new information regarding vessel
strike, the potential impact of the new gray whale UME, and the revised
humpback whale stock structure were discussed earlier in the rule).
In the discussions below, the estimated Level B harassment takes
represent instances of take, not the number of individuals taken (the
much lower and less frequent Level A harassment takes are far more
likely to be associated with separate individuals), and in many cases,
some individuals are expected to be taken more than one time while in
other cases, a portion of individuals will not be taken at all. Below,
we compare the total take numbers (including PTS, TTS, and behavioral
disturbance) for species or stocks to their associated abundance
estimates to evaluate the magnitude of impacts across the species or
stock and to individuals. Specifically, when an abundance percentage
comparison is below 100, it means that percentage or less of the
individuals in the stock will be affected (i.e., some individuals will
not be taken at all), that the average for those taken is 1 day per
year, and that we would not expect any individuals to be taken more
than a few times in a year. When it is more than 100 percent, it means
there will definitely be some number of repeated takes of individuals.
For example, if the percentage is 300, the average would be each
individual is taken on 3 days in a year if all were taken, but it is
more likely that some number of individuals will be taken more than
three times and some number of individuals fewer times or not at all.
While it is not possible to know the maximum number of days across
which individuals of a stock might be taken, in acknowledgement of the
fact that it is more than the average, for the purposes of this
analysis, we assume a number approaching twice the average. For
example, if the percentage of take compared to the abundance is 800, we
estimate that some individuals might be taken as many as 16 times.
Those comparisons are included in the sections below. For some stocks,
these numbers have been adjusted slightly (with these adjustments being
in the single digits) so as to more consistently apply this approach,
but these minor changes did not change the analysis or findings.
To assist in understanding what this analysis means, we clarify a
few issues related to estimated takes and the analysis here. An
individual that incurs a PTS or TTS take may sometimes, for example,
also be subject to behavioral disturbance at the same time. As
described in the Harassment subsection of the Analysis and Negligible
Impact Determination section of the 2018 HSTT final rule, the degree of
PTS, and the degree and duration of TTS, expected to be incurred from
the Navy's activities are not expected to impact marine mammals such
that their reproduction or survival could be affected. Similarly, data
do not suggest that a single instance in which an animal accrues PTS or
TTS and is also subjected to behavioral disturbance would result in
impacts to reproduction or survival. Alternately, we recognize that if
an individual is subjected to behavioral disturbance repeatedly for a
longer duration and on consecutive days, effects could accrue to the
point that reproductive success is jeopardized (as discussed below in
the stock-specific summaries). Accordingly, in analyzing the number of
takes and the likelihood of repeated and sequential takes (which could
result in reproductive impacts), we consider the total takes, not just
the Level B harassment takes by behavioral disturbance, so that
individuals potentially exposed to both threshold shift and behavioral
disturbance are appropriately considered. We note that the same
reasoning applies with the potential addition of behavioral disturbance
to tissue damage from explosives, the difference being that we do
already consider the likelihood of reproductive impacts whenever tissue
damage occurs. Further, the number of Level A harassment takes by
either PTS or tissue damage are so low compared to abundance numbers
that it is considered highly unlikely that any individual would be
taken at those levels more than once.
Having considered all of the information and analyses previously
presented in the 2018 HSTT final rule, including the Group and Species-
Specific Analyses discussions organized by the different groups and
species, below we present tables showing instances of total take as a
percentage of stock abundance for each group, updated with the new
vessel strike calculations and humpback stock structure. We then
summarize the information for each species or stock, considering the
analysis from the 2018 HSTT final rule, 2020 HSTT final rule, and any
new analysis. The analyses below in some cases address species
collectively if they occupy the same functional hearing group (i.e.,
low, mid, and high-frequency cetaceans and pinnipeds in water), share
similar life history strategies, and/or are known to behaviorally
respond similarly to acoustic stressors. Because some of these groups
or species share characteristics that inform the impact analysis
similarly, it would be duplicative to repeat the same analysis for each
species or stock. In addition, animals belonging to each stock within a
species typically have the same hearing capabilities and behaviorally
respond in the same manner as animals in other stocks within the
species.
Mysticetes
In table 12 and table 13 below for mysticetes, we indicate the
total annual mortality, Level A harassment, and Level B harassment, and
a number indicating the instances of total take as a percentage of
abundance. Table 12 and table 13 have been updated from tables 18 and
19 in the 2020 HSTT final rule, as appropriate, with the 2022 final
SARs and updated information on mortality, as discussed above. For
additional information and analysis supporting the negligible-impact
analysis, see the Mysticetes discussion in the Group and Species-
Specific Analyses section of the 2018 HSTT final rule, all of which
remains applicable to this proposed rule unless specifically noted.

[[Page 68335]]

Table 12--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Mysticetes in the HRC Portion of the HSTT Study Area and Number Indicating the Instances of Total
Take as a Percentage of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental take (not all Total takes \a\ Abundance Instance of total take
takes represent separate individuals, especially for -------------------------------------------- as percent of
disturbance) abundance
---------------------------------------------------------- -----------------------
Level B harassment Level A Total Total Navy Total EEZ take
Species Stock --------------------------- harassment takes Takes abundance Within EEZ take as as
------------------ (entire (within inside Navy percentage percentage
TTS (may Mortality study Navy and abundance of total of Navy
Behavioral also include Tissue \b\ area) EEZ) outside of (HRC) Navy EEZ
disturbance disturbance) PTS damage EEZ (HRC) abundance abundance
(HRC) (HRC)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale............................. Central North Pacific.... 15 33 0 0 0 48 40 43 33 112 121
Bryde's whale.......................... Hawaii................... 40 106 0 0 0 146 123 108 89 135 138
Fin whale.............................. Hawaii................... 21 27 0 0 0 48 41 52 40 92 103
Humpback whale......................... Hawaii................... 2,837 6,289 3 0 0.29 9,129 7,389 5,078 4,595 180 161
Minke whale............................ Hawaii................... 1,233 3,697 2 0 0 4,932 4,030 3,652 2,835 135 142
Sei whale.............................. Hawaii................... 46 121 0 0 0 167 135 138 107 121 126
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the Hawaii take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine
Mammals section of the 2018 HSTT final rule), both in and outside of the U.S. EEZ. Because the portion of the Navy's study area inside the U.S. EEZ is generally concomitant with the area
used to generate the abundance estimates in the SARs, and the abundance predicted by the same underlying density estimates is the preferred abundance to use, there is no need to separately
compare the take to the SARs abundance estimate.
\a\ Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.
\b\ The annual mortality of 0.29 is the result of no more than two mortalities over the course of 7 years from vessel strikes as described above in the Estimated Take of Marine Mammals
section.

Table 13--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Mysticetes in the SOCAL Portion of the HSTT Study Area and Number Indicating the Instances of
Total Take as a Percentage of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental take (not Total Abundance Instance of total take
all takes represent separate individuals, especially takes ------------------------ as percent of
for disturbance) \a\ abundance
------------------------------------------------------------------- -----------------------
Level B harassment Level A Total
--------------------------- harassment Navy take as Total
Species Stock ----------------- Total abundance NMFS SARS percentage take as
TTS (may Mortality takes in action abundance of total percentage
Behavioral also \b\ (entire area Navy of total
disturbance include PTS Tissue study (SOCAL) abundance SAR
disturbance) damage Area) in action abundance
area
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale.................................. Eastern North Pacific.......... 792 1,196 1 0 0.14 1,989 785 1,898 253 105
Bryde's whale............................... Eastern Tropical Pacific....... 14 27 0 0 0 41 1.3 unknown 3,154 unknown
Fin whale................................... CA/OR/WA....................... 835 1,390 1 0 0.57 2,227 363 11,065 613 20
Humpback whale.............................. Central America/Southern Mexico- 282 594 0 0 0 876 \c\ 74 1,496 1,184 59
CA/OR/WA.
Mainland Mexico- CA/OR/WA...... 198 920 1 0 0.14 1,119 \c\ 173 3,477 647 32
Minke whale................................. CA/OR/WA....................... 259 666 1 0 0 926 163 915 568 101
Sei whale................................... Eastern North Pacific.......... 27 52 0 0 0.14 79 3 519 2,633 15
Gray whale.................................. Eastern North Pacific.......... 1,316 3,355 7 0 0.57 4,679 193 26,960 2,424 17
Gray whale.................................. Western North Pacific.......... 2 4 0 0 0 6 0 290 0 2
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond
and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare
predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule).
\a\ Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.
\b\ The annual mortality of 0.14 is the result of no more than one mortality over the course of 7 years from vessel strikes as described above in the Estimated Take of Marine Mammals section.
The annual mortality of 0.57 is the result of no more than four mortalities over the course of 7 years from vessel strikes.
\c\ In the 2020 HSTT final rule, NMFS reported a Navy abundance in Action Area (SOCAL) of 247 CA/OR/WA humpback whales. As explained in more detail in the Estimated Take from Vessel Strikes
and Explosives by Serious Injury or Mortality, NMFS estimates that approximately 30 percent of the humpback whales off the coast of California may be from the Central America DPS with the
remaining 70 percent are expected to be from the Mexico DPS. Therefore, of the estimated 247 humpback whales in SOCAL, NMFS anticipates that 74 would be of the Central America/Southern
Mexico-CA/OR/WA stock (Central America DPS), and 173 would be of the Mainland Mexico-CA/OR/WA stock (Mexico DPS).

[[Page 68336]]

Blue Whale (Eastern North Pacific Stock)

Blue whales are listed as endangered under the ESA, and the current
population trend for the Eastern North Pacific stock is unknown. We
further note that this stock was originally listed under the ESA as a
result of the impacts from commercial whaling, which is no longer
affecting the species. NMFS proposes to authorize one mortality over
the 7 years covered by this rulemaking or 0.14 mortality annually. With
the addition of this 0.14 annual mortality, residual PBR is exceeded,
resulting in the total human-caused mortality exceeding PBR by 15.54.
However, as described in more detail in the Serious Injury or Mortality
section above, when total human-caused mortality exceeds PBR, we
consider whether the incremental addition of a small amount of
authorized mortality from the specified activity may still result in a
negligible impact, in part by identifying whether it is less than 10
percent of PBR. In this case, the authorized mortality is well below 10
percent of PBR, management measures are in place to reduce mortality
from other sources, and the incremental addition of a single mortality
over the course of the 7-year Navy rule is not expected to, alone, lead
to adverse impacts on the stock through effects on annual rates of
recruitment or survival.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated total instances of
take compared to the abundance (measured against both the Navy-
estimated abundance and the SAR) is 253 and 105 percent, respectively
(table 13). Given the range of blue whales, this information suggests
that only some portion of individuals in the stock are likely impacted,
but that there will likely be some repeat exposure (maybe 5 or 6 days
within a year) of some subset of individuals that spend extended time
within SOCAL. Regarding the severity of those individual Level B
harassment takes by behavioral disturbance, the duration of any
exposure is expected to be between minutes and hours (i.e., relatively
short) and the received sound levels largely below 172 dB with a
portion up to 178 dB (i.e., of a moderate or lower level, less likely
to evoke a severe response). Additionally, the Navy implements time/
area mitigation in SOCAL in the majority of the BIAs, which will reduce
the severity of impacts to blue whales by reducing interference in
feeding that could result in lost feeding opportunities or necessitate
additional energy expenditure to find other good opportunities.
Regarding the severity of TTS takes, we have explained in the 2018 HSTT
final rule that they are expected to be low-level, of short duration,
and mostly not in a frequency band that would be expected to interfere
with blue whale communication or other important low-frequency cues--
and that the associated lost opportunities and capabilities are not at
a level that would impact reproduction or survival. For similar reasons
(as described in the 2018 HSTT final rule) the single estimated Level A
harassment take by PTS for this stock is unlikely to have any effect on
the reproduction or survival of that one individual, even if it were to
be experienced by an animal that also experiences one or more Level B
harassment takes by behavioral disturbance.
Altogether, only a small portion of the stock is anticipated to be
impacted and any individual blue whale is likely to be disturbed at a
low-moderate level, with likely many animals exposed only once or twice
and a subset potentially disturbed across 5 or 6 days but minimized in
biologically important areas. This low magnitude and severity of
harassment effects is not expected to result in impacts on the
reproduction or survival of any individuals and, therefore, when
combined with the proposed authorized mortality (which our earlier
analysis indicated would not, alone, have more than a negligible impact
on this stock of blue whales), the total take is not expected to
adversely affect this stock through impacts on annual rates of
recruitment or survival. For these reasons, we have preliminarily
determined, in consideration of all of the effects of the Navy's
activities combined, that the authorized take proposed would have a
negligible impact on the Eastern North Pacific stock of blue whales.

Bryde's Whale (Eastern Tropical Pacific Stock)

Little is known about this stock or its status, and it is not
listed under the ESA. No mortality or Level A harassment is anticipated
or proposed to be authorized. Regarding the magnitude of Level B
harassment takes (TTS and behavioral disturbance), the number of
estimated total instances of take compared to the abundance is 3,154
percent; however, the abundance upon which this percentage is based
(1.3 whales from the Navy estimate, which is extrapolated from density
estimates based on very few sightings) is clearly erroneous and the SAR
does not include an abundance estimate because all of the survey data
is outdated (table 13). However, the abundance in the early 1980s was
estimated as 22,000 to 24,000, a portion of the stock was estimated at
13,000 in 1993, and the minimum number in the Gulf of California was
estimated at 160 in 1990. Given this information and the fact that 41
total takes of Bryde's whales were estimated, this information suggests
that only a small portion of the individuals in the stock are likely
impacted, and few, if any, are likely taken over more than 1 day.
Regarding the severity of those individual Level B harassment takes by
behavioral disturbance, the duration of any exposure is expected to be
between minutes and hours (i.e., relatively short) and the received
sound levels largely below 172 dB with a portion up to 178 dB (i.e., of
a moderate or lower level, less likely to evoke a severe response).
Regarding the severity of TTS takes, they are expected to be low-level,
of short duration, and mostly not in a frequency band that would be
expected to interfere with Bryde's whale communication or other
important low-frequency cues. Any associated lost opportunities and
capabilities are not at a level that would impact reproduction or
survival.
Altogether, only a small portion of the stock is anticipated to be
impacted and any individual Bryde's whale is likely to be disturbed at
a low-moderate level, with few, if any, individuals exposed over more
than 1 day in the year. This low magnitude and severity of harassment
effects is not expected to result in impacts on individual reproduction
or survival, much less annual rates of recruitment or survival. For
these reasons, we have preliminarily determined, in consideration of
all of the effects of the Navy's activities combined, that the
authorized take proposed would have a negligible impact on the Eastern
Tropical Pacific stock of Bryde's whales.

Fin Whale (CA/OR/WA Stock)

The SAR identifies this stock as ``increasing,'' even though the
larger species is listed as endangered under the ESA. NMFS proposes to
authorize four mortalities over the 7 years covered by this rulemaking,
or 0.57 mortality annually. The addition of this 0.57 annual mortality
still leaves the total human-caused mortality well under residual PBR.

[[Page 68337]]

We acknowledge the 2021 vessel strike of two fin whales by the
Royal Australian Navy, and that the 2021 and 2023 vessel strikes by the
U.S. Navy could have been CA/OR/WA fin whales. While the Royal
Australian Navy strikes are not quantitatively included in the
estimated take by vessel strike, even if they were, and if we presumed
that the 2021 and 2023 U.S. Navy strikes were all fin whales, M/SI of
this stock would still fall well below PBR (80).
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated total instances of
take compared to the abundance (measured against both the Navy-
estimated abundance and the SAR) is 613 and 20 percent, respectively
(table 13). This information suggests that only some portion (less than
25 percent) of individuals in the stock are likely impacted but that
there is likely some repeat exposure (perhaps up to 12 days within a
year) of some subset of individuals that spend extended time within the
SOCAL complex. Some of these takes could occur on a few sequential days
for some small number of individuals, for example, if they resulted
from a multi-day exercise on a range while individuals were in the area
for multiple days feeding. Regarding the severity of those individual
Level B harassment takes by behavioral disturbance, the duration of any
exposure is expected to be between minutes and hours (i.e., relatively
short) and the received sound levels largely below 172 dB with a
portion up to 178 dB (i.e., of a moderate or lower level, less likely
to evoke a severe response). Additionally, while there are no known
BIAs for fin whales in the SOCAL range, the Navy implements time/area
mitigation in SOCAL in blue whale BIAs, and fin whales are known to
sometimes feed in some of the same areas, which means they could
potentially accrue some benefits from the mitigation. Regarding the
severity of TTS takes, they are expected to be low-level, of short
duration, and mostly not in a frequency band that would be expected to
interfere with fin whale communication or other important low-frequency
cues--and that the associated lost opportunities and capabilities are
not at a level that would impact reproduction or survival. For similar
reasons (as described in the 2018 HSTT final rule) the single estimated
Level A harassment take by PTS for this stock is unlikely to have any
effects on the reproduction or survival of that one individual.
Altogether, this population is increasing, only a small portion of
the stock is anticipated to be impacted, and any individual fin whale
is likely to be disturbed at a low-moderate level, with the taken
individuals likely exposed between 1 and 12 days, with a few
individuals potentially taken on a few sequential days. This low
magnitude and severity of harassment effects is not expected to result
in impacts on individual reproduction or survival, and therefore, when
combined with the proposed authorized mortality (which our earlier
analysis indicated would not, alone, have more than a negligible impact
on this stock of fin whales), the total take is not expected to
adversely affect this stock through impacts on annual rates of
recruitment or survival. For these reasons, we have preliminarily
determined, in consideration of all of the effects of the Navy's
activities combined, that the authorized take proposed would have a
negligible impact on the CA/OR/WA stock of fin whales.

Humpback Whale (Central America/Southern Mexico-CA/OR/WA Stock)

The SAR identifies this stock as increasing, though the growth rate
is uncertain. Animals in this stock are of the Central America DPS
which is designated as endangered under the ESA.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated total instances of
take compared to the abundance (measured against both the Navy-
estimated abundance and the SAR) is 1,184 and 59 percent, respectively
(table 11). Given the range of humpback whales, this information
suggests that only some portion of individuals in the stock are likely
impacted but that there is likely some repeat exposure (perhaps up to
23 days within a year) of some subset of individuals that spend
extended time within the SOCAL complex. Regarding the severity of those
individual Level B harassment takes by behavioral disturbance, the
duration of any exposure is expected to be between minutes and hours
(i.e., relatively short) and the received sound levels largely below
172 dB with a portion up to 178 dB (i.e., of a moderate or lower level,
less likely to evoke a severe response). Some of these takes could
occur on several sequential days for some small number of individuals,
for example, if they resulted from a multi-day exercise on a range
while individuals were in the area for multiple days feeding. However,
in these amounts, it would still not be expected to adversely impact
reproduction or survival of any individuals.
Regarding the severity of TTS takes, they are expected to be low-
level, of short duration, and mostly not in a frequency band that would
be expected to interfere with humpback whale communication or other
important low-frequency cues--and that the associated lost
opportunities and capabilities are not at a level that would impact
reproduction or survival. Altogether, only a small portion of the stock
is anticipated to be impacted and any individual humpback whale is
likely to be disturbed at a low-moderate level, with likely many
animals exposed only once or twice and a subset potentially disturbed
up to 23 days, but with no reason to think that more than a few of
those days would be sequential. This low magnitude and severity of
harassment effects is not expected to result in impacts on the
reproduction or survival of any individuals and, therefore, the total
take is not expected to adversely affect this stock through impacts on
annual rates of recruitment or survival. For these reasons, we have
preliminarily determined, in consideration of all of the effects of the
Navy's activities combined, that the authorized take proposed would
have a negligible impact on the Central America/Southern Mexico-CA/OR/
WA stock of humpback whales.
Humpback Whale (Mainland Mexico-CA/OR/WA Stock)
The status of this stock is unknown. Animals in this stock are of
the Mexico DPS which is designated as threatened under the ESA. NMFS
proposes to authorize one mortality over the 7 years covered by this
rulemaking, or 0.14 mortality annually. The addition of this 0.14
annual mortality still leaves the total human-caused mortality well
under residual PBR.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated total instances of
take compared to the abundance (measured against both the Navy-
estimated abundance and the SAR) is 647 and 32 percent, respectively
(table 13). Given the range of humpback whales, this information
suggests that only some portion of individuals in the stock are likely
impacted but that there is likely some repeat exposure (perhaps up to
13 days within a year) of some subset of individuals that spend
extended time within the SOCAL complex. Regarding the severity of those
individual Level B harassment takes by behavioral disturbance, the
duration of any exposure is expected to be between minutes and hours
(i.e., relatively short) and the received sound levels largely below
172 dB with a portion up to 178

[[Page 68338]]

dB (i.e., of a moderate or lower level, less likely to evoke a severe
response). Some of these takes could occur on several sequential days
for some small number of individuals, for example, if they resulted
from a multi-day exercise on a range while individuals were in the area
for multiple days feeding. However, in these amounts, it would still
not be expected to adversely impact reproduction or survival of any
individuals.
Regarding the severity of TTS takes, they are expected to be low-
level, of short duration, and mostly not in a frequency band that would
be expected to interfere with humpback whale communication or other
important low-frequency cues--and that the associated lost
opportunities and capabilities are not at a level that would impact
reproduction or survival. For similar reasons (as described in the 2018
HSTT final rule) the single estimated Level A harassment take by PTS
for this stock is unlikely to have any effects on the reproduction or
survival of that one individual.
Altogether, only a small portion of the stock is anticipated to be
impacted and any individual humpback whale is likely to be disturbed at
a low-moderate level, with likely many animals exposed only once or
twice and a subset potentially disturbed up to 13 days, but with no
reason to think that more than a few of those days would be sequential.
This low magnitude and severity of harassment effects is not expected
to result in impacts on the reproduction or survival of any individuals
and, therefore, when combined with the proposed authorized mortality
(which our earlier analysis indicated would not, alone, have more than
a negligible impact on this stock of humpback whales), the total take
is not expected to adversely affect this stock through impacts on
annual rates of recruitment or survival. For these reasons, we have
preliminarily determined, in consideration of all of the effects of the
Navy's activities combined, that the authorized take proposed would
have a negligible impact on the CA/OR/WA stock of humpback whales.

Minke Whale (CA/OR/WA Stock)

The status of this stock is unknown and it is not listed under the
ESA. No mortality from vessel strike or tissue damage from explosive
exposure is anticipated or proposed for authorization for this species.
Regarding the magnitude of Level B harassment takes (TTS and behavioral
disturbance), the number of estimated total instances of take compared
to the abundance (measured against both the Navy-estimated abundance
and the SAR) is 568 and 101 percent, respectively (table 11). Based on
the behaviors of minke whales, which often occur along continental
shelves and sometimes establish home ranges along the West Coast, this
information suggests that only a portion of individuals in the stock
are likely impacted but that there is likely some repeat exposure
(perhaps up to 11 days within a year) of some subset of individuals
that spend extended time within the SOCAL complex. Some of these takes
could occur on a few sequential days for some small number of
individuals, for example, if they resulted from a multi-day exercise on
a range while individuals were in the area for multiple days feeding.
Regarding the severity of those individual Level B harassment takes by
behavioral disturbance, the duration of any exposure is expected to be
between minutes and hours (i.e., relatively short) and the received
sound levels largely below 172 dB with a portion up to 178 dB (i.e., of
a moderate or lower level, less likely to evoke a severe response).
Regarding the severity of TTS takes, they are expected to be low-level,
of short duration, and mostly not in a frequency band that would be
expected to interfere with minke whale communication or other important
low-frequency cues--and that the associated lost opportunities and
capabilities are not at a level that would impact reproduction or
survival. For similar reasons (as described in the 2018 HSTT final
rule) the single estimated Level A harassment take by PTS for this
stock is unlikely to have any effects on the reproduction or survival
of that individual.
Altogether, only a portion of the stock is anticipated to be
impacted and any individual minke whale is likely to be disturbed at a
low-moderate level, with the taken individuals likely exposed between 1
and 11 days, with a few individuals potentially taken on a few
sequential days. This low magnitude and severity of harassment effects
is not expected to result in impacts on individual reproduction or
survival, much less annual rates of recruitment or survival. For these
reasons, we have preliminarily determined, in consideration of all of
the effects of the Navy's activities combined, that the authorized take
proposed would have a negligible impact on the CA/OR/WA stock of minke
whales.

Sei Whale (Eastern North Pacific Stock)

The status of this stock is unknown, and sei whales are listed
under the ESA. NMFS proposes to authorize one mortality over the 7
years covered by this rulemaking or 0.14 mortality annually. The
addition of this 0.14 annual mortality still leaves the total human-
caused mortality under residual PBR. After additionally considering
several qualitative factors described above, including that the 2023
strike could have been a sei whale (or fin whale), we do not expect one
authorized lethal take from Navy activities, alone, to adversely affect
Eastern North Pacific sei whales through effects on annual rates of
recruitment or survival. No Level A harassment is anticipated or
proposed for authorization.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated total instances of
take compared to the abundance (measured against both the Navy-
estimated abundance and the SAR) is 2,633 and 15 percent, respectively
(table 13), however, the abundance upon which the Navy percentage is
based (3 from the Navy estimate, which is extrapolated from density
estimates based on very few sightings) is likely an underestimate of
the number of individuals in the HSTT study Area, resulting in an
overestimated percentage. Given this information and the large range of
sei whales, and the fact that only 79 total Level B harassment takes of
sei whales were estimated, it is likely that some very small number of
sei whales would be taken repeatedly, potentially up to 15 days in a
year (typically 2,633 percent would lead to the estimate of 52 days/
year, however, given that there are only 79 sei whale total takes, we
used the conservative assumption that five individuals might be taken
up to 15 times, with the few remaining takes distributed among other
individuals). Regarding the severity of those individual Level B
harassment takes by behavioral disturbance, the duration of any
exposure is expected to be between minutes and hours (i.e., relatively
short) and the received sound levels largely below 172 dB with a
portion up to 178 dB (i.e., of a moderate or lower level, less likely
to evoke a severe response). Some of these takes could occur on a few
sequential days for some small number of individuals, for example, if
they resulted from a multi-day exercise on a range while individuals
were in the area for multiple days feeding, however, in these amounts
it would still not be expected to adversely impact reproduction or
survival of any individuals. Regarding the severity of TTS takes, they
are expected to be low-level, of short duration, and mostly not in a
frequency band that would be expected to interfere with sei whale

[[Page 68339]]

communication or other important low-frequency cues--and that the
associated lost opportunities and capabilities are not at a level that
would impact reproduction or survival.
Altogether, only a small portion of the stock is anticipated to be
impacted and any individual sei whale is likely to be disturbed at a
low-moderate level, with only a few individuals exposed over one to 15
days in a year, with no more than a few sequential days. This low
magnitude and severity of harassment effects is not expected to result
in impacts on individual reproduction or survival, and therefore, when
combined with the proposed authorized mortality (which our earlier
analysis indicated would not, alone, have more than a negligible impact
on this stock of sei whales), the total take is not expected to
adversely affect this stock through impacts on annual rates of
recruitment or survival. For these reasons, we have preliminarily
determined, in consideration of all of the effects of the Navy's
activities combined, that the authorized take proposed would have a
negligible impact on the Eastern North Pacific stock of sei whales.

Gray Whale (Eastern North Pacific Stock)

The Eastern North Pacific stock of gray whale is not ESA-listed and
the SAR indicates that the stock is increasing. However, recent (2021-
2022) surveys conducted by NMFS' Southwest Fisheries Science Center
estimated that the population has declined to 16,650 whales, though the
authors note that this stock has historically shown a pattern of
population growth and decline that has not impacted the population in
the long term (Eguchi et al. 2022). NMFS is proposing to authorize four
mortalities over the 7 years covered by this rulemaking, or 0.57
mortality annually. The addition of this 0.57 annual mortality still
leaves the total human-caused mortality well under the insignificance
threshold of residual PBR (670). On May 31, 2019, NMFS declared the
unusual spike in strandings of gray whales along the west coast of
North America since January 1, 2019 an UME. As of June 25, 2023, 674
gray whales have stranded along the west coast of North America (in the
U.S., Canada, and Mexico) under this UME. Given the small number of
takes by serious injury or mortality proposed for authorization, the
proposed takes are not anticipated to exacerbate the ongoing UME.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated total instances of
take compared to the abundance (measured against both the Navy-
estimated abundance and the SAR) is 2,424 and 16 percent, respectively
(table 13). (Note that in comparison to the recent Eguchi et al. 2022
abundance estimate, the number of estimated total instances of take
compared to the abundance would be 28 percent.) This information
suggests that only some small portion of individuals in the stock are
likely impacted (less than 17 percent) but that there is likely some
level of repeat exposure of some subset of individuals that spend
extended time within the SOCAL complex. Typically 2,424 percent would
lead to the estimate of 48 days/year, however, given that a large
number of gray whales are known to migrate through the SOCAL complex
and the fact that there are 4,679 total takes, we believe that it is
more likely that a larger number of individuals would be taken one to a
few times, while a small number staying in an area to feed for several
days may be taken on 5-10 days. Regarding the severity of those
individual Level B harassment takes by behavioral disturbance, the
duration of any exposure is expected to be between minutes and hours
(i.e., relatively short) and the received sound levels largely below
172 dB with a portion up to 178 dB (i.e., of a moderate or lower level,
less likely to evoke a severe response). Some of these takes could
occur on a couple of sequential days for some small number of
individuals; however, in these amounts it would still not be expected
to adversely impact reproduction or survival of any individuals.
Regarding the severity of TTS takes, they are expected to be low-
level, of short duration, and mostly not in a frequency band that would
be expected to interfere with gray whale communication or other
important low-frequency cues and that the associated lost opportunities
and capabilities are not at a level that would impact reproduction or
survival. For these same reasons (low level and frequency band), while
a small permanent loss of hearing sensitivity may include some degree
of energetic costs for compensating or may mean some small loss of
opportunities or detection capabilities, at the expected scale the
seven estimated Level A harassment takes by PTS for gray whales would
be unlikely to impact behaviors, opportunities, or detection
capabilities to a degree that would interfere with reproductive success
or survival of any individuals.
Altogether, we have considered the impacts of the gray whale UME,
the Eastern North Pacific stock of gray whales is not endangered or
threatened under the ESA. The SAR indicates that the stock is
increasing. However, recent (2021-2022) surveys conducted by NMFS'
Southwest Fisheries Science Center estimated that the population has
declined (Eguchi et al. 2022). Only a small portion of the stock is
anticipated to be impacted and any individual gray whale is likely to
be disturbed at a low-moderate level, with likely many animals exposed
only once or twice and a subset potentially disturbed across 5 to 10
days. This low magnitude and severity of harassment effects is not
expected to result in impacts to reproduction or survival for any
individuals and, therefore, when combined with the proposed authorized
mortality of four whales over the 7 year period (which our earlier
analysis indicated would not, alone, have more than a negligible impact
on this stock of gray whales), the total take is not expected to
adversely affect this stock through impacts on annual rates of
recruitment or survival. For these reasons, we have preliminarily
determined, in consideration of all of the effects of the Navy's
activities combined, that the authorized take proposed would have a
negligible impact on the Eastern North Pacific stock of gray whales.

Gray Whale (Western North Pacific stock)

The Western North Pacific stock of gray whales is reported as
increasing in the 2022 final SAR but is listed as endangered under the
ESA. No mortality or Level A harassment is anticipated or proposed for
authorization. This stock is expected to incur the very small number of
6 Level B harassment takes (2 behavioral disruption and 4 TTS) to a
stock with a SAR-estimated abundance of 290 (table 11). These takes
will likely accrue to different individuals, the behavioral
disturbances will be of a low-moderate level, and the TTS instances
will be at a low level and short duration. This low magnitude and
severity of harassment effects is not expected to result in impacts on
individual reproduction or survival, much less to adversely affect this
stock through impacts on annual rates of recruitment or survival. For
these reasons, we have preliminarily determined, in consideration of
all of the effects of the Navy's activities combined, that the
authorized take proposed would have a negligible impact on the Western
North Pacific stock of gray whales.

Humpback Whale (Hawaii Stock)

The status of this stock is unknown. Animals in this stock are of
the Hawaii

[[Page 68340]]

DPS which is not listed under the ESA. No Level A harassment by tissue
damage is proposed for authorization. NMFS proposes to authorize two
mortalities over the 7 years covered by this rulemaking, or 0.29
mortalities annually. The addition of this 0.29 annual mortality still
leaves the total human-caused mortality well under the insignificance
threshold for residual PBR.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated instances of take
compared to the abundance, both throughout the HSTT Study Area and
within the U.S. EEZ, respectively, is 180 and 161 percent (table 12).
This information and the complicated far-ranging nature of the stock
structure suggests that some portion of the stock (but not all) are
likely impacted, over 1 to several days per year, with little
likelihood of take across sequential days. Regarding the severity of
those individual Level B harassment takes by behavioral disturbance,
the duration of any exposure is expected to be between minutes and
hours (i.e., relatively short) and the received sound levels largely
below 172 dB with a portion up to 178 dB (i.e., of a moderate or lower
level, less likely to evoke a severe response). Additionally, as noted
above, there are two mitigation areas implemented by the Navy that span
a large area of the important humpback reproductive area (BIA) and
minimize impacts by limiting the use of MF1 active sonar and
explosives, thereby reducing both the number and severity of takes of
humpback whales. Regarding the severity of TTS takes, they are expected
to be low-level, of short duration, and mostly not in a frequency band
that would be expected to interfere with humpback whale communication
or other important low-frequency cues, and that the associated lost
opportunities and capabilities are not at a level that would impact
reproduction or survival. For these same reasons (low level and
frequency band), while a small permanent loss of hearing sensitivity
may include some degree of energetic costs for compensating or may mean
some small loss of opportunities or detection capabilities, at the
expected scale the 3 estimated Level A harassment takes by PTS for
humpback whales would be unlikely to impact behaviors, opportunities,
or detection capabilities to a degree that would interfere with
reproductive success or survival of any individuals.
Altogether, this stock's status is unknown and the DPS is not
listed as endangered or threatened under the ESA. Only a small portion
of the stock is anticipated to be impacted and any individual humpback
whale is likely to be disturbed at a low-moderate level, with the taken
individuals likely exposed between 1 to several days per year, with
little likelihood of take across sequential days. This low magnitude
and severity of harassment effects is not expected to result in impacts
on individual reproduction or survival, and therefore, when combined
with the proposed authorized mortality (which our earlier analysis
indicated would not, alone, have more than a negligible impact on this
stock of humpback whales), the total take is not expected to adversely
affect this stock through effects on annual rates of recruitment or
survival. For these reasons, we have preliminarily determined, in
consideration of all of the effects of the Navy's activities combined,
that the authorized take proposed would have a negligible impact on the
Hawaii stock of humpback whales.

Blue Whale (Central North Pacific Stock) and the Hawaii Stocks of
Bryde's Whale, Fin Whale, Minke Whale, and Sei Whale

The status of these stocks are not identified in the SARs. Blue
whale (Central North Pacific stock) and the Hawaii stocks of fin whale
and sei whale are listed as endangered under the ESA; the Hawaii stocks
of minke whales and Bryde's whales are not listed under the ESA. No
mortality or Level A harassment by tissue damage is anticipated or
proposed for authorization for any of these stocks.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated instances of take
compared to the abundance, both throughout the HSTT Study Area and
within the U.S. EEZ, respectively, is 92-135 and 103-142 percent (table
12). This information suggests that some portion of the stocks (but not
all) are likely impacted, over 1 to several days per year, with little
likelihood of take across sequential days. Regarding the severity of
those individual Level B harassment takes by behavioral disturbance,
the duration of any exposure is expected to be between minutes and
hours (i.e., relatively short) and the received sound levels largely
below 172 dB with a portion up to 178 dB (i.e., of a moderate or lower
level, less likely to evoke a severe response). Regarding the severity
of TTS takes, they are expected to be low-level, of short duration, and
mostly not in a frequency band that would be expected to interfere with
mysticete communication or other important low-frequency cues--and that
the associated lost opportunities and capabilities are not at a level
that would impact reproduction or survival. For similar reasons (as
described in the 2018 HSTT final rule) the two estimated Level A
harassment takes by PTS for the Hawaii stock of minke whales are
unlikely to have any effects on the reproduction or survival of any
individuals.
Altogether, only a portion of these stocks are anticipated to be
impacted and any individuals of these stocks are likely to be disturbed
at a low-moderate level, with the taken individuals likely exposed
between 1 and several days, with little chance that any are taken
across sequential days. This low magnitude and severity of harassment
effects is not expected to result in impacts on individual reproduction
or survival, much less have impacts on annual rates of recruitment or
survival. For these reasons, we have preliminarily determined, in
consideration of all of the effects of the Navy's activities combined,
that the authorized take proposed would have a negligible impact on
these stocks.
Odontocetes

Sperm Whale, Dwarf Sperm Whale, and Pygmy Sperm Whale

In table 14 and table 15 below for sperm whale, dwarf sperm whale,
and pygmy sperm whale, we indicate the total annual mortality (0 for
all stocks; the 2020 HSTT final rule included 0.14 annual takes by
mortality of the Hawaii stock of sperm whale), Level A and Level B
harassment, and a number indicating the instances of total take as a
percentage of abundance. Table 14 and table 15 are unchanged from
tables 20 and 21 in the 2020 HSTT final rule, except for updated
information on mortality for the Hawaii stock of sperm whales, as
discussed above. For additional information and analysis supporting the
negligible-impact analysis, see the Odontocetes discussion as well as
the Sperm Whales, Dwarf Sperm Whales, and Pygmy Sperm Whales discussion
in the Group and Species-Specific Analyses section of the 2018 HSTT
final rule, all of which remains applicable to this proposed rule
unless specifically noted.

[[Page 68341]]

Table 14--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Sperm Whales, Dwarf Sperm Whales, and Pygmy Sperm Whales in the HRC Portion of the HSTT Study Area
and Number Indicating the Instances of Total Take as a Percentage of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental Total takes Abundance Instances of total
take (not all takes represent separate --------------------------------------------------------- take as percent of
individuals, especially for disturbance) abundance
---------------------------------------------- -----------------------
Level B harassment Level A Total Total Navy Total take
Species Stock --------------------------- harassment takes Takes abundance Within EEZ as EEZ take
------------------- Mortality (entire (within inside and Navy percentage as
TTS (may study NAVY outside abundance of total percentage
Behavioral also include Tissue area) EEZ) EEZ (HRC) (HRC) Navy of EEZ
disturbance disturbance) PTS damage abundance abundance
(HRC) (HRC)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Dwarf sperm whale..................... Hawaii................... 5,870 14,550 64 0 0 20,484 15,310 8,218 6,379 249 240
Pygmy sperm whale..................... Hawaii................... 2,329 5,822 29 0 0 8,180 6,098 3,349 2,600 244 235
Sperm whale........................... Hawaii................... 2,466 30 0 0 0 2,496 1,317 1,656 1,317 151 147
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the Hawaii take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine
Mammals section of the 2018 HSTT final rule), both in and outside of the U.S. EEZ. Because the portion of the Navy's study area inside the U.S. EEZ is generally concomitant with the area
used to generate the abundance estimates in the SARs, and the abundance predicted by the same underlying density estimates is the preferred abundance to use, there is no need to separately
compare the take to the SARs abundance estimate.
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.

Table 15--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Sperm Whales, Dwarf Sperm Whales, and Pygmy Sperm Whales in the SOCAL Portion of the HSTT Study
Area and Number Indicating the Instances of Total Take as a Percentage of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental Total takes Abundance Instances of total
take (not all takes represent separate ----------------------------------------------- take as percent of
individuals, especially for disturbance) abundance
---------------------------------------------- -----------------------
Level B harassment Level A Total take
--------------------------- harassment Total Navy as Total take
Species Stock ------------------- takes abundance NMFS SARS percentage as
Mortality (entire in action abundance of total percentage
Behavioral TTS (may study area Navy of total
disturbance also include PTS Tissue area) abundance SAR
disturbance) damage in Action abundance
Area
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Kogia whales............................... CA/OR/WA...................... 2,779 6,353 38 0 0 9,170 757 4,111 1,211 223
Sperm whale................................ CA/OR/WA...................... 2,437 56 0 0 0 2,493 273 1,997 913 125
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond
and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare
predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule).
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.

Below we compile and summarize the information that supports our
preliminary determination that the Navy's activities would not
adversely affect any species or stocks through effects on annual rates
of recruitment or survival for any of the affected species and stocks
addressed in this section.
Sperm Whale, Dwarf Sperm Whale, and Pygmy Sperm Whale (CA/OR/WA Stocks)
The SAR identifies the CA/OR/WA stock of sperm whales as
``stable'', and the species is listed as endangered under the ESA. The
status of the CA/OR/WA stocks of pygmy and dwarf sperm whales is
unknown and neither are listed under the ESA. Neither mortality nor
Level A harassment by tissue damage from exposure to explosives is
expected or proposed for authorization for any of these three stocks.
Due to their pelagic distribution, small size, and cryptic
behavior, pygmy sperm whales and dwarf sperm whales are rarely sighted
during at-sea surveys and are difficult to distinguish between when
visually observed in the field. Many of the relatively few observations
of Kogia spp. off the U.S. West Coast were not identified to species.
All at-sea sightings of Kogia spp. have been identified as pygmy sperm
whales or Kogia spp. Stranded dwarf sperm and pygmy sperm whales have
been found on the U.S. West Coast, however dwarf sperm whale strandings
are rare. NMFS SARs suggest that the majority of Kogia sighted off the
U.S. West Coast were likely pygmy sperm whales. As such, the stock
estimate in the NMFS SAR for pygmy sperm whales is the estimate derived
for all Kogia spp. in the region (Barlow, 2016), and no separate
abundance estimate can be determined for dwarf sperm whales, though
some low number likely reside in the U.S. EEZ. Due to the lack of
abundance estimate, it is not possible to predict the take of dwarf
sperm whales and take estimates are identified as Kogia spp. (including
both pygmy and dwarf sperm whales). We assume only a small portion of
those takes are likely to be dwarf sperm whales as the density and
abundance in the U.S. EEZ is thought to be low.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated total instances of
take compared to the abundance (measured against both the Navy-
estimated abundance and the SAR) is, respectively, 913 and 125 for
sperm whales and 1,211 and 223 for Kogia spp., with a large proportion
of

[[Page 68342]]

these anticipated to be pygmy sperm whales due to the low abundance and
density of dwarf sperm whales in the HSTT Study Area. (Table 15). Given
the range of these stocks (which extends the entire length of the West
Coast, as well as beyond the U.S. EEZ boundary), this information
suggests that some portion of the individuals in these stocks will not
be impacted but that there is likely some repeat exposure (perhaps up
to 24 days within a year for Kogia spp. and 18 days a year for sperm
whales) of some small subset of individuals that spend extended time
within the SOCAL Range. Additionally, while interrupted feeding bouts
are a known response and concern for odontocetes, we also know that
there are often viable alternative habitat options in the relative
vicinity. Regarding the severity of those individual Level B harassment
takes by behavioral disturbance, the duration of any exposure is
expected to be between minutes and hours (i.e., relatively short) and
the received sound levels largely below 172 dB (i.e., of a lower, to
occasionally moderate, level and less likely to evoke a severe
response). However, some of these takes could occur on a fair number of
sequential days for some number of individuals.
Regarding the severity of TTS takes, they are expected to be low-
level, of short duration, and mostly not in a frequency band that would
be expected to interfere with sperm whale communication or other
important low-frequency cues, and that the associated lost
opportunities and capabilities are not at a level that would impact
reproduction or survival. For these same reasons (low level and
frequency band), while a small permanent loss of hearing sensitivity
(PTS) may include some degree of energetic costs for compensating or
may mean some small loss of opportunities or detection capabilities, at
the expected scale the estimated Level A harassment takes by PTS for
the dwarf and pygmy sperm whale stocks would be unlikely to impact
behaviors, opportunities, or detection capabilities to a degree that
would interfere with reproductive success or survival of any
individuals. Thus, the 38 total Level A harassment takes by PTS for
these two stocks would be unlikely to affect rates of recruitment and
survival for the stocks.
Altogether, most members of the stocks will likely be taken by
Level B harassment (at a low to occasionally moderate level) over
several days a year, and some smaller portion of the stocks are
expected to be taken on a relatively moderate to high number of days
(up to 18 or 24) across the year, some of which could be sequential
days. Though the majority of impacts are expected to be of a lower to
sometimes moderate severity, the larger number of takes for a subset of
individuals makes it more likely that a small number of individuals
could be interrupted during foraging in a manner and amount such that
impacts to the energy budgets of females (from either losing feeding
opportunities or expending considerable energy to find alternative
feeding options) could cause them to forego reproduction for a year.
Energetic impacts to males are generally meaningless to population
rates unless they cause death, and it takes extreme energy deficits
beyond what would ever be likely to result from these activities to
cause the death of an adult marine mammal. As discussed in the 2020
HSTT final rule, however, foregone reproduction (especially for 1 year,
which is the maximum predicted because the small number anticipated in
any 1 year makes the probability that any individual would be impacted
in this way twice in 7 years very low) has far less of an impact on
population rates than mortality and a small number of instances of
foregone reproduction would not be expected to adversely affect these
stocks through effects on annual rates of recruitment or survival. We
also note that residual PBR is 19 for pygmy sperm whales and 1.9 for
sperm whales. Both the abundance and PBR are unknown for dwarf sperm
whales, however, we know that take of this stock is likely
significantly lower in magnitude and severity (i.e., lower number of
total takes and repeated takes any individual) than pygmy sperm whales.
For these reasons, in consideration of all of the effects of the Navy's
activities combined, we have preliminarily determined that the
authorized take proposed would have a negligible impact on the CA/OR/WA
stocks of sperm whales and pygmy and dwarf sperm whales.
Sperm Whale (Hawaii Stock)
The SAR does not identify a trend for this stock and the species is
listed as endangered under the ESA. No mortality or Level A harassment
by PTS or tissue damage is expected or proposed for authorization.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated instances of take
compared to the abundance, both throughout the HSTT Study Area and
within the U.S. EEZ, respectively, is 151 and 147 percent (table 14).
This information and the sperm whale stock range suggest that likely
only a smaller portion of the stock would be impacted, over 1 to
several days per year, with little likelihood of take across sequential
days. Regarding the severity of those individual Level B harassment
takes by behavioral disturbance, the duration of any exposure is
expected to be between minutes and hours (i.e., relatively short) and
the received sound levels largely below 172 dB (i.e., of a lower, to
occasionally moderate, level and less likely to evoke a severe
response). Regarding the severity of TTS takes, they are expected to be
low-level, of short duration, and mostly not in a frequency band that
would be expected to interfere with sperm whale communication or other
important low-frequency cues, and that the associated lost
opportunities and capabilities are not at a level that would impact
reproduction or survival.
Altogether, a relatively small portion of this stock is anticipated
to be impacted and any individuals are likely to be disturbed at a low-
moderate level, with the taken individuals likely exposed between 1 and
several days, with little chance that any are taken across sequential
days. This low magnitude and severity of harassment effects is not
expected to result in impacts on individual reproduction or survival,
much less annual rates of recruitment or survival. For these reasons,
we have preliminarily determined, in consideration of all of the
effects of the Navy's activities combined, that the authorized take
proposed would have a negligible impact on the Hawaii stock of sperm
whales.
Pygmy and Dwarf Sperm Whales (Hawaii Stocks)
The SAR does not identify a trend for these stocks and the species
are not listed under the ESA. No Level A harassment by tissue damage is
anticipated or proposed for authorization. Regarding the magnitude of
Level B harassment takes (TTS and behavioral disturbance), the number
of estimated instances of take compared to the abundance, both
throughout the HSTT Study Area and within the U.S. EEZ, respectively,
is 244-249 and 235-240 percent (table 12). This information and the
pygmy and dwarf sperm whale stock ranges (at least throughout the U.S.
EEZ around the entire Hawaiian Islands) suggest that likely a fair
portion of each stock is not impacted, but that a subset of individuals
may be taken over one to perhaps 5 days per year, with little
likelihood of take across sequential days. Regarding the severity of
those individual Level B harassment takes by behavioral disturbance,
the duration of any exposure is expected to

[[Page 68343]]

be between minutes and hours (i.e., relatively short) and the received
sound levels largely below 172 dB (i.e., of a lower, to occasionally
moderate, level and less likely to evoke a severe response).
Additionally, as discussed earlier, within the Hawaii Island Mitigation
Area, explosives are not used and the use of MF1 and MF4 active sonar
is limited, greatly reducing the severity of impacts within the small
and resident population BIA for dwarf sperm whales (Kratofil et al.,
2023), which is entirely contained within this mitigation area.
Regarding the severity of TTS takes, they are expected to be low-
level, of short duration, and mostly not in a frequency band that would
be expected to interfere with sperm whale communication or other
important low-frequency cues--and that the associated lost
opportunities and capabilities are not at a level that would impact
reproduction or survival. For these same reasons (low level and
frequency band), while a small permanent loss of hearing sensitivity
may include some degree of energetic costs for compensating or may mean
some small loss of opportunities or detection capabilities, at the
expected scale, estimated Level A harassment takes by PTS for dwarf and
pygmy sperm whales would be unlikely to impact behaviors,
opportunities, or detection capabilities to a degree that would
interfere with reproductive success or survival of any individuals,
even if it were to be experienced by an animal that also experiences
one or more instances of Level B harassment by behavioral disturbance.
Thus the 29 and 64 total Level A harassment takes by PTS for dwarf and
pygmy sperm whales, respectively, would be unlikely to affect rates of
recruitment and survival for these stocks.
Altogether, a portion of these stocks are likely to be impacted and
any individuals are likely to be disturbed at a low-moderate level,
with the taken individuals likely exposed between 1 and 5 days, with
little chance that any are taken across sequential days. This low
magnitude and severity of Level A and Level B harassment effects is not
expected to result in impacts on individual reproduction or survival,
much less impacts on annual rates of recruitment or survival. For these
reasons, we have preliminarily determined, in consideration of all of
the effects of the Navy's activities combined, that the expected and
authorized take proposed would have a negligible impact on the Hawaii
stocks of pygmy and dwarf sperm whales.

Beaked Whales

In table 16 and table 17 below for beaked whales, we indicate the
total annual mortality, Level A and Level B harassment, and a number
indicating the instances of total take as a percentage of abundance.
Table 16 and table 17 are unchanged from table 22 and table 23 in the
2020 HSTT final rule, with the exception of a correction to a rounding
error as noted. For additional information and analysis supporting the
negligible-impact analysis, see the Odontocetes discussion as well as
the Beaked Whales discussion in the Group and Species-Specific Analyses
section of the 2018 HSTT final rule, all of which remains applicable to
this proposed rule unless specifically noted.

Table 16--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Beaked Whales in the HRC Portion of the HSTT Study Area and Number Indicating the Instances of
Total Take as a Percentage of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental take (not all Total takes Abundance Instances of total
takes represent separate individuals, especially for -------------------------------------------- take as percent of
disturbance) abundance
----------------------------------------------------------- -----------------------
Level B harassment Level A harassment Total Total Navy Total take
Species Stock ----------------------------------------------------------- Takes Takes abundance Within EEZ as EEZ take
(entire (within inside and Navy percentage as
TTS (may Study Navy outside abundance of total percentage
Behavioral also include PTS Tissue Mortality Area) EEZ) EEZ (HRC) (HRC) Navy of EEZ
disturbance disturbance) damage abundance abundance
(HRC) (HRC)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Blainville's beaked whale............. Hawaii................... 5,369 16 0 0 0 5,385 4,140 989 768 \a\ 544 539
Cuvier's beaked whale................. Hawaii................... 1,792 4 0 0 0 1,796 1,377 345 268 521 514
Longman's beaked whale................ Hawaii................... 19,152 81 0 0 0 19,233 14,585 3,568 2,770 539 527
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the Hawaii take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine
Mammals section of the 2018 HSTT final rule), both in and outside of the U.S. EEZ. Because the portion of the Navy's study area inside the U.S. EEZ is generally concomitant with the area
used to generate the abundance estimates in the SARs, and the abundance predicted by the same underlying density estimates is the preferred abundance to use, there is no need to separately
compare the take to the SARs abundance estimate.
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.
\a\ The 2020 final rule unintentionally presented this percentage as 545. The correct value is provided here. This error does not affect the conclusions in the 2020 HSTT final rule.

[[Page 68344]]

Table 17--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Beaked Whales in the SOCAL Portion of the HSTT Study Area and Number Indicating the Instances of
Total Take as a Percentage of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental Total takes Abundance Instances of total
take (not all takes represent separate ----------------------------------------------- take as percent of
individuals, especially for disturbance) abundance
---------------------------------------------- -----------------------
Level B harassment Level A Total take
--------------------------- harassment Total Navy as Total take
Species Stock ------------------- Takes abundance NMFS SARS percentage as
Mortality (entire in action abundance of total percentage
Behavioral TTS (may study area Navy of total
disturbance also include PTS Tissue area) abundance SAR
disturbance) damage in action abundance
area
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Baird's beaked whale....................... CA/OR/WA...................... 2,030 14 0 0 0 2,044 74 1,363 2,762 150
Cuvier's beaked whale...................... CA/OR/WA...................... 11,373 127 1 0 0 11,501 520 5,454 2,212 211
Mesoplodon species......................... CA/OR/WA...................... 6,125 68 1 0 0 6,194 89 3,044 6,960 203
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond
and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare
predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule).
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.

Below we compile and summarize the information that supports our
determination that the Navy's activities would not adversely affect any
species or stocks through effects on annual rates of recruitment or
survival for any of the affected species or stocks addressed in this
section.
Blainville's, Cuvier's, and Longman's Beaked Whales (Hawaii Stocks)
The SAR does not identify a trend for these stocks and the species
are not listed under the ESA. No mortality or Level A harassment are
expected or proposed for authorization for any of these three stocks.
Regarding the magnitude of Level B harassment takes (TTS and behavioral
disturbance), the number of estimated instances of take compared to the
abundance, both throughout the HSTT Study Area and within the U.S. EEZ,
respectively, is 521-544 and 514-539 percent (table 16). This
information and the stock ranges (at least of the small, resident
island associated stocks around Hawaii) suggest that likely a fair
portion of the stocks (but not all) will be impacted, over 1 to perhaps
11 days per year, with little likelihood of much take across sequential
days. Regarding the severity of those individual Level B harassment
takes by behavioral disturbance, the duration of any exposure is
expected to be between minutes and hours (i.e., relatively short) and
the received sound levels largely below 160 dB, though with beaked
whales, which are considered somewhat more sensitive, this could mean
that some individuals will leave preferred habitat for a day or 2
(i.e., moderate level takes). However, while interrupted feeding bouts
are a known response and concern for odontocetes, we also know that
there are often viable alternative habitat options nearby.
Additionally, as noted earlier, within the Hawaii Island mitigation
area (which overlaps a large portion of the BIAs for Cuvier's and
Blainville's beaked whales), explosives are not used and the use of MF1
and MF4 active sonar is limited, greatly reducing the severity of
impacts within these two small resident populations.
Regarding the severity of TTS takes, they are expected to be low-
level, of short duration, and mostly not in a frequency band that would
be expected to interfere with beaked whale communication or other
important low-frequency cues, and that the associated lost
opportunities and capabilities are not at a level that would impact
reproduction or survival.
Altogether, a fair portion of these stocks are anticipated to be
impacted and any individuals are likely to be disturbed at a moderate
level, with the taken individuals likely exposed between 1 and 11 days,
with little chance that individuals are taken across more than a few
sequential days. This low, to occasionally moderate, magnitude and
severity of harassment effects is not expected to result in impacts on
individual reproduction or survival, much less have impacts on annual
rates of recruitment or survival. For these reasons, we have
preliminarily determined, in consideration of all of the effects of the
Navy's activities combined, that the authorized take proposed would
have a negligible impact on the Hawaii stocks of beaked whales.
Baird's and Cuvier's Beaked Whales and Mesoplodon Species (All CA/OR/WA
Stocks)
The species are not listed under the ESA and their populations have
been identified as ``increasing,'' ``decreasing,'' and ``increasing,''
respectively. No mortality is expected or proposed for authorization
for any of these three stocks and only two takes by Level A harassment
(PTS) are proposed for authorization.
No methods are available to distinguish between the six species of
Mesoplodon beaked whale CA/OR/WA stocks (Blainville's beaked whale (M.
densirostris), Perrin's beaked whale (M. perrini), Lesser beaked whale
(M. peruvianus), Stejneger's beaked whale (M. stejnegeri), Gingko-
toothed beaked whale (M. gingkodens), and Hubbs' beaked whale (M.
carlhubbsi)) when observed during at-sea surveys (Carretta et al.
2018a). Bycatch and stranding records from the region indicate that the
Hubbs' beaked whale is most commonly encountered (Carretta et al. 2008,
Moore and Barlow, 2013). As indicated in the SAR, no species-specific
abundance estimates are available, the abundance estimate includes all
CA/OR/WA Mesoplodon spp, and the six species are managed as one unit.
Due to the lack of species-specific abundance estimates, it is not
possible to predict the take of individual species and take estimates
are identified as Mesoplodon spp.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated total instances of
take compared to the abundance for these stocks is 2,762, 2,212, and
6,960 percent (measured against Navy-estimated abundance) and

[[Page 68345]]

150, 211, and 203 percent (measured against the SAR) for Baird's beaked
whales, Cuvier's beaked whales, and Mesoplodon spp., respectively
(table 15). Given the ranges of these stocks, this information suggests
that some smaller portion of the individuals of these stocks will be
taken, and that some subset of individuals within the stock will be
taken repeatedly within the year (perhaps up to 20-25 days, and
potentially more for Cuvier's)--potentially over a fair number of
sequential days, especially where individuals spend extensive time in
the SOCAL Range. Note that we predict lower days of repeated exposure
for these stocks than their percentages might have suggested because of
the number of overall takes--i.e., using the higher percentage would
suggest that an unlikely portion of the takes are taken up by a small
portion of the stock incurring a very large number of repeat takes,
with little room for take resulting from few or moderate numbers of
repeats, which is unlikely. While interrupted feeding bouts are a known
response and concern for odontocetes, we also know that there are often
viable alternative habitat options in the relative vicinity. Regarding
the severity of those individual Level B harassment takes by behavioral
disturbance, we have explained that the duration of any exposure is
expected to be between minutes and hours (i.e., relatively short) and
the received sound levels largely below 160 dB, though with beaked
whales, which are considered somewhat more sensitive, this could mean
that some individuals will leave preferred habitat for a day or 2
(i.e., of a moderate level). In addition, as noted, some of these takes
could occur on a fair number of sequential days for these stocks.
The severity of TTS takes is expected to be low-level, of short
duration, and mostly not in a frequency band that would be expected to
interfere significantly with conspecific communication, echolocation,
or other important low-frequency cues. Therefore, the associated lost
opportunities and capabilities would not be expected to impact
reproduction or survival. For similar reasons (as described in the 2020
HSTT final rule) the single estimated Level A harassment take by PTS
for this stock is unlikely to have any effects on the reproduction or
survival of any individuals.
Altogether, a portion of these stocks will likely be taken (at a
moderate or sometimes low level) over several days a year, and some
smaller portion of the stock is expected to be taken on a relatively
moderate to high number of days across the year, some of which could be
sequential days. Though the majority of impacts are expected to be of a
moderate severity, the repeated takes over a potentially fair number of
sequential days for some individuals makes it more likely that a small
number of individuals could be interrupted during foraging in a manner
and amount such that impacts to the energy budgets of females (from
either losing feeding opportunities or expending considerable energy to
find alternative feeding options) could cause them to forego
reproduction for a year. Energetic impacts to males are generally
meaningless to population rates unless they cause death, and it takes
extreme energy deficits beyond what would ever be likely to result from
these activities to cause the death of an adult marine mammal. As noted
previously, however, foregone reproduction (especially for 1 year,
which is the maximum predicted because the small number anticipated in
any 1 year makes the probability that any individual would be impacted
in this way twice in 7 years very low) has far less of an impact on
population rates than mortality and a small number of instances of
foregone reproduction would not be expected to adversely affect these
stocks through effects on annual rates of recruitment or survival,
especially given the residual PBR of these three beaked whale stocks
(8.7, 41.9, and 19.9, respectively).
Further, Navy activities have been conducted in SOCAL for many
years at similar levels and the SAR considers Mesoplodon spp. and
Baird's beaked whales as increasing. While NMFS' SAR indicates that
Cuvier's beaked whales on the U.S. West Coast are declining based on a
Bayesian trend analysis of NMFS' survey data collected from 1991
through 2014, results from passive acoustic monitoring and other
research have estimated regional Cuvier's beaked whale densities that
were higher than indicated by NMFS' broad-scale visual surveys for the
U.S. West Coast (Debich et al. 2015a; Debich et al. 2015b; Falcone and
Schorr, 2012, 2014; Hildebrand et al. 2009; Moretti, 2016;
[Scaron]irovi[cacute] et al. 2016; Smultea and Jefferson, 2014).
Research also indicates higher than expected residency in the Navy's
instrumented Southern California Anti-Submarine Warfare Range in
particular (Falcone and Schorr, 2012) and photo identification studies
in the SOCAL have identified approximately 100 individual Cuvier's
beaked whale individuals with 40 percent having been seen in one or
more prior years, with re-sightings up to 7 years apart (Falcone and
Schorr, 2014). The documented residency by many Cuvier's beaked whales
over multiple years suggests that a stable population may exist in that
small portion of the stock's overall range (Falcone et al. 2009;
Falcone and Schorr, 2014; Schorr et al. 2017).
For these reasons, in consideration of all of the effects of the
Navy's activities combined, we have preliminarily determined that the
authorized take proposed would have a negligible impact on the CA/OR/WA
stocks of Baird's and Cuvier's beaked whales, as well as all six
species included within the Mesoplodon spp.

Small Whales and Dolphins

In table 18 and table 19 below for dolphins and small whales, we
indicate the total annual mortality, Level A and Level B harassment,
and a number indicating the instances of total take as a percentage of
abundance. Table 18 and table 19 are updated from tables 24 and 25 in
the 2020 HSTT final rule as appropriate with the 2022 final SARs. For
additional information and analysis supporting the negligible-impact
analysis, see the Odontocetes discussion as well as the Small Whales
and Dolphins discussion in the Group and Species-Specific Analyses
section of the 2018 HSTT final rule, all of which remains applicable to
this proposed rule unless specifically noted.

[[Page 68346]]

Table 18--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Dolphins and Small Whales in the HRC Portion of the HSTT Study Area and Number Indicating the
Instances of Total Take as a Percentage of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental take (not all Total takes Abundance Instance of total take
takes represent separate individuals, especially for -------------------------------------------- as percent of
disturbance) abundance
----------------------------------------------------------- Total -----------------------
Level B harassment Level A Total Navy Total EEZ take
Species Stock --------------------------- harassment takes Takes abundance Within take as as
------------------- (entire (within inside and EEZ Navy percentage percentage
TTS (may Mortality study Navy outside abundance of total of Navy
Behavioral also Tissue area) EEZ) of EEZ (HRC) Navy EEZ
disturbance include PTS damage (HRC) abundance abundance
disturbance) (HRC) (HRC)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Bottlenose dolphin.................... Hawaii Pelagic........... 3,196 132 0 0 0 3,328 2,481 1,528 1,442 218 172
Bottlenose dolphin.................... Kauai & Niihau........... 534 31 0 0 0 565 264 184 184 307 143
Bottlenose dolphin.................... Oahu..................... 8,600 61 1 0 0 8,662 8,376 743 743 \a\ 1,166 \a\ 1,127
Bottlenose dolphin.................... 4-Island................. 349 10 0 0 0 359 316 189 189 190 167
Bottlenose dolphin.................... Hawaii................... 74 6 0 0 0 80 42 131 131 61 32
False killer whale.................... Hawaii Pelagic........... 999 42 0 0 0 1,041 766 645 507 161 151
False killer whale.................... Main Hawaiian Islands 572 17 0 0 0 589 476 147 147 \b\ 401 324
Insular.
False killer whale.................... Northwestern Hawaiian 365 16 0 0 0 381 280 215 169 177 166
Islands.
Fraser's dolphin...................... Hawaii................... 39,784 1,289 2 0 0 41,075 31,120 5,408 18,763 760 166
Killer whale.......................... Hawaii................... 118 6 0 0 0 124 93 69 54 180 172
Melon-headed whale.................... Hawaii Islands........... 3,261 231 0 0 0 3,492 2,557 1,782 1,782 196 143
Melon-headed whale.................... Kohala Resident.......... 341 9 0 0 0 350 182 447 447 78 41
Pantropical spotted dolphin........... Hawaii Island............ 3,767 227 0 0 0 3,994 2,576 2,405 2,405 166 107
Pantropical spotted dolphin........... Hawaii Pelagic........... 9,973 476 0 0 0 10,449 7,600 5,462 4,637 191 164
Pantropical spotted dolphin........... Oahu..................... 4,284 45 0 0 0 4,329 4,194 372 372 1,164 1,127
Pantropical spotted dolphin........... 4-Island................. 701 17 0 0 0 718 634 657 657 109 96
Pygmy killer whale.................... Hawaii................... 8,122 402 0 0 0 8,524 6,538 4,928 3,931 173 166
Pygmy killer whale.................... Tropical................. 710 50 0 0 0 760 490 159 23 478 2,130
Risso's dolphin....................... Hawaii................... 8,950 448 0 0 0 9,398 7,318 1,210 4,199 777 174
Rough-toothed dolphin................. Hawaii................... 6,112 373 0 0 0 6,485 4,859 3,054 2,808 212 173
Short-finned pilot whale.............. Hawaii................... 12,499 433 0 0 0 12,932 9,946 6,433 5,784 201 172
Spinner dolphin....................... Hawaii Island............ 279 12 0 0 0 291 89 629 629 46 14
Spinner dolphin....................... Hawaii Pelagic........... 4,332 202 0 0 0 4,534 3,491 2,885 2,229 157 157
Spinner dolphin....................... Kauai & Niihau........... 1,683 63 0 0 0 1,746 812 604 604 289 134

[[Page 68347]]

Spinner dolphin....................... Oahu & 4-Island.......... 1,790 34 1 0 0 1,825 1,708 354 354 516 482
Striped dolphin....................... Hawaii................... 7,379 405 0 0 0 7,784 6,034 4,779 3,646 163 165
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the Hawaii take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine
Mammals section of the 2018 HSTT final rule), both in and outside of the U.S. EEZ. Because the portion of the Navy's study area inside the U.S. EEZ is generally concomitant with the area
used to generate the abundance estimates in the SARs, and the abundance predicted by the same underlying density estimates is the preferred abundance to use, there is no need to separately
compare the take to the SARs abundance estimate.
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.
\a\ The 2020 final rule unintentionally presented these percentages as 1,169 and 1,130. The correct values are provided here. These errors do not affect the conclusions in the 2020 HSTT final
rule.
\b\ The 2020 final rule unintentionally presented this percentage as 400. The correct value is provided here. This rounding error does not affect the conclusions in the 2020 HSTT final rule.

Table 19--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Dolphins and Small Whales in the SOCAL Portion of the HSTT Study Area and Number Indicating the
Instances of Total Take as a Percentage of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental take (not all Total Abundance Instance of total take
takes represent separate individuals, especially for takes ------------------------ as percent of
disturbance) ------------ abundance
----------------------------------------------------------- -----------------------
Level B harassment Level A Total
--------------------------- harassment Total Navy take as Total
Species Stock ------------------- takes abundance NMFS SARS percentage take as
TTS (may (entire in action abundance of total percentage
Behavioral also Mortality study area Navy of total
disturbance include PTS Tissue area) (SOCAL) abundance SAR
disturbance) damage in action abundance
area
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Bottlenose dolphin........................ California Coastal........... 1,771 38 0 0 0 1,809 238 453 760 399
Bottlenose dolphin........................ CA/OR/WA Offshore............ 51,727 3,695 3 0 0 55,425 5,946 3,477 932 1,594
Killer whale.............................. ENP Offshore................. 96 11 0 0 0 107 4 300 2,675 36
Killer whale.............................. ENP Transient/West Coast 179 20 0 0 0 199 30 349 663 57
Transient.
Long-beaked common dolphin................ California................... 233,485 13,787 18 2 0 247,292 10,258 83,379 2,411 297
Northern right whale dolphin.............. CA/OR/WA..................... 90,052 8,047 10 1 0 98,110 7,705 29,285 1,273 335
Pacific white-sided dolphin............... CA/OR/WA..................... 69,245 6,093 5 0 0 75,343 6,626 34,999 1,137 215
Risso's dolphin........................... CA/OR/WA..................... 116,143 10,118 9 0 0 126,270 7,784 6,336 1,622 1,993
Short-beaked common dolphin............... CA/OR/WA..................... 1,374,048 118,525 79 10 1.14 1,492,664 261,438 1,056,308 571 141
Short-finned pilot whale.................. CA/OR/WA..................... 1,789 124 1 0 0 1,914 208 836 920 229
Striped dolphin........................... CA/OR/WA..................... 163,640 11,614 3 0 0 175,257 39,862 29,988 440 584
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond
and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare
predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule).
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.
For mortality takes there is an annual average of 1.14 short-beaked common dolphins (i.e., where eight takes could potentially occur divided by 7 years to get the annual number of mortalities/
serious injuries).

[[Page 68348]]

Long-Beaked Common Dolphin (California Stock), Northern Right Whale
Dolphin (CA/OR/WA Stock), and Short-Beaked Common Dolphin (CA/OR/WA
Stock)
None of these stocks are listed under the ESA and their stock
statuses are considered ``increasing,'' ``unknown,'' and
``increasing,'' respectively. Eight mortalities or serious injuries of
short-beaked common dolphins are proposed for authorization over the 7-
year rule, or 1.14 M/SI annually. The addition of this 1.14 annual
mortality still leaves the total human-caused mortality well under the
insignificance threshold for residual PBR. The three stocks are
expected to accrue 2, 1, and 10 Level A harassment takes from tissue
damage resulting from exposure to explosives, respectively. As
described in detail in the 2018 HSTT final rule, the impacts of a Level
A harassment take by tissue damage could range in impact from minor to
something just less than M/SI that could seriously impact fitness.
However, given the Navy's procedural mitigation, exposure closer to the
source and more severe end of the spectrum is less likely and we
cautiously assume some moderate impact for these takes that could lower
the affected individual's fitness within the year such that a female
(assuming a 50 percent chance of it being a female) might forego
reproduction for 1 year. As noted previously, foregone reproduction has
less of an impact on population rates than death (especially for only 1
year in 7, which is the maximum predicted because the small number
anticipated in any 1 year makes the probability that any individual
would be impacted in this way twice in 7 years very low), and 1 to 10
instances would not be expected to impact annual rates of recruitment
or survival for these stocks.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated total instances of
take compared to the abundance (measured against both the Navy-
estimated abundance and the SAR) is 2,411, 1,273, and 571 percent
(respective to the stocks listed in the heading) and 297, 335, and 141
percent (respective to the stocks listed in the heading) (table 19).
Given the range of these stocks, this information suggests that likely
some portion (but not all or even the majority) of the individuals in
the northern right whale dolphin and short-beaked common dolphin stocks
are likely impacted while it is entirely possible that most or all of
the range-limited long-beaked common dolphin is taken. All three stocks
likely will experience some repeat Level B harassment exposure (perhaps
up to 48, 25, or 11 days within a year, respective to the stocks listed
in the heading) of some subset of individuals that spend extended time
within the SOCAL range complex. While interrupted feeding bouts are a
known response and concern for odontocetes, we also know that there are
often viable alternative habitat options in the relative vicinity.
Regarding the severity of those individual Level B harassment takes by
behavioral disturbance, the duration of any exposure is expected to be
between minutes and hours (i.e., relatively short) and the received
sound levels largely below 172 dB with a portion up to 178 dB (i.e., of
a moderate or lower level, less likely to evoke a severe response).
However, some of these takes could occur on a fair number of sequential
days for long-beaked common dolphins or northern right whale dolphins,
or even some number of short-beaked common dolphins, given the high
number of total takes (i.e., the probability that some number of
individuals get taken on a higher number of sequential days is higher,
because the total take number is relatively high, even though the
percentage is not that high).
The severity of TTS takes is expected to be low-level, of short
duration, and mostly not in a frequency band that would be expected to
interfere significantly with conspecific communication, echolocation,
or other important low-frequency cues, and the associated lost
opportunities and capabilities would not be expected to impact
reproduction or survival. For these same reasons (low level and
frequency band), while a small permanent loss of hearing sensitivity
may include some degree of energetic costs for compensating or may mean
some small loss of opportunities or detection capabilities, as
discussed in the 2020 HSTT final rule, it would be unlikely to impact
behaviors, opportunities, or detection capabilities to a degree that
would interfere with reproductive success or survival of any
individuals.
Altogether and as described in more detail above, 1.14 annual
lethal takes of short-beaked common dolphins are proposed for
authorization, all three stocks may experience a very small number of
takes by tissue damage or PTS (relative to the stock abundance and
PBR), and a moderate to large portion of all three stocks will likely
be taken (at a low to occasionally moderate level) over several days a
year, and some smaller portion of these stocks is expected to be taken
on a relatively moderate to high number of days across the year, some
of which could be sequential days. Though the majority of impacts are
expected to be of a lower to sometimes moderate severity, the larger
number of takes (in total and for certain individuals) makes it more
likely (probabilistically) that a small number of individuals could be
interrupted during foraging in a manner and amount such that impacts to
the energy budgets of females (from either losing feeding opportunities
or expending considerable energy to find alternative feeding options)
could cause them to forego reproduction for a year. Energetic impacts
to males are generally meaningless to population rates unless they
cause death, and it takes extreme energy deficits beyond what would
ever be likely to result from these activities to cause the death of an
adult marine mammal. As noted previously, however, foregone
reproduction (especially for only 1 year out of 7, which is the maximum
predicted because the small number anticipated in any 1 year makes the
probability that any individual would be impacted in this way twice in
7 years very low) has far less of an impact on population rates than
mortality and a small number of instances of foregone reproduction
(including in combination with that which might result from the small
number of tissue damage takes) would not be expected to adversely
affect the stocks through effects on annual rates of recruitment or
survival, especially given the very high residual PBRs of these stocks
(638.3, 156.4, and 8,858.5, respectively). For these reasons, in
consideration of all of the effects of the Navy's activities combined
(mortality, Level A harassment, and Level B harassment), we have
preliminarily determined that the authorized take proposed would have a
negligible impact on these three stocks of dolphins.
All Other SOCAL Dolphin Stocks (Except Long-Beaked Common Dolphin,
Northern Right Whale Dolphin, and Short-Beaked Common Dolphin)
None of these stocks are listed under the ESA and their stock
statuses are considered ``unknown,'' except for the bottlenose dolphin
(California coastal stock) and killer whale (Eastern North Pacific
stock), which are considered ``stable.'' No M/SI or Level A harassment
via tissue damage from exposure to explosives is expected or proposed
for authorization for these stocks.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated total instances of
take compared to the

[[Page 68349]]

abundance (measured against both the Navy-estimated abundance and the
SAR) is from 440 to 2,675 percent and 36 to 1,993 percent, respectively
(table 19). Given the range of these stocks (along the entire U.S. West
Coast, or even beyond, with some also extending seaward of the HSTT
Study Area boundaries), this information suggests that some portion
(but not all or even the majority) of the individuals of any of these
stocks will be taken, with the exception that most or all of the
individuals of the more range-limited California coastal stock of
bottlenose dolphin may be taken. It is also likely that some subset of
individuals within most of these stocks will be taken repeatedly within
the year (perhaps up to 10-15 days within a year) but with no more than
several potentially sequential days, although the CA/OR/WA stocks of
bottlenose dolphins, Pacific white-sided dolphins, and Risso's dolphins
may include individuals that are taken repeatedly within the year over
a higher number of days (up to 57, 22, and 40 days, respectively) and
potentially over a fair number of sequential days, especially where
individuals spend extensive time in the SOCAL range complex. Note that
though percentages are high for the Eastern North Pacific stock of
killer whales and short-finned pilot whales, given the low overall
number of takes, it is highly unlikely that any individuals would be
taken across the number of days their percentages would suggest. While
interrupted feeding bouts are a known response and concern for
odontocetes, we also know that there are often viable alternative
habitat options in the relative vicinity. Regarding the severity of
those individual Level B harassment takes by behavioral disturbance, we
have explained that the duration of any exposure is expected to be
between minutes and hours (i.e., relatively short) and the received
sound levels largely below 172 dB (i.e., of a lower, or sometimes
moderate level, less likely to evoke a severe response). However, as
noted, some of these takes could occur on a fair number of sequential
days for the three stocks listed earlier.
The severity of TTS takes is expected to be low-level, of short
duration, and mostly not in a frequency band that would be expected to
interfere significantly with conspecific communication, echolocation,
or other important low-frequency cues. For these same reasons (low
level and frequency band), while a small permanent loss of hearing
sensitivity may include some degree of energetic costs for compensating
or may mean some small loss of opportunities or detection capabilities,
it would be unlikely to impact behaviors, opportunities, or detection
capabilities to a degree that would interfere with reproductive success
or survival of any individuals.
Altogether, a portion of all of these stocks will likely be taken
(at a low to occasionally moderate level) over several days a year, and
some smaller portion of CA/OR/WA stocks of bottlenose dolphins, Pacific
white-sided dolphins, and Risso's dolphins, specifically, are expected
to be taken on a relatively moderate to high number of days across the
year, some of which could be sequential days. Though the majority of
impacts are expected to be of a lower to sometimes moderate severity,
the larger number of takes (in total and for certain individuals) for
the CA/OR/WA stocks of bottlenose dolphins, Pacific white-sided
dolphins, and Risso's dolphins makes it more likely (probabilistically)
that a small number of individuals could be interrupted during foraging
in a manner and amount such that impacts to the energy budgets of
females (from either losing feeding opportunities or expending
considerable energy to find alternative feeding options) could cause
them to forego reproduction for a year. Energetic impacts to males are
generally meaningless to population rates unless they cause death, and
it takes extreme energy deficits beyond what would ever be likely to
result from these activities to cause the death of an adult marine
mammal. As noted previously, however, foregone reproduction (especially
for only 1 year in 7, which is the maximum predicted because the small
number anticipated in any 1 year makes the probability that any
individual would be impacted in this way twice in 7 years very low) has
far less of an impact on population rates than mortality and a small
number of instances of foregone reproduction would not be expected to
adversely affect the stocks through effects on annual rates of
recruitment or survival, especially given the residual PBRs of the CA/
OR/WA stocks of bottlenose dolphins, Pacific white-sided dolphins, and
Risso's dolphins (18.9, 272, and 42.3, respectively). For these
reasons, in consideration of all of the effects of the Navy's
activities combined, we have preliminarily determined that the
authorized take proposed would have a negligible impact on these stocks
of dolphins.
All HRC Dolphin Stocks
With the exception of the Main Hawaiian Island stock of false
killer whales (listed as endangered under the ESA, with the MMPA stock
identified as ``decreasing''), none of these stocks are listed under
the ESA and their stock statuses are considered ``unknown.'' No M/SI or
Level A harassment via tissue damage from exposure to explosives is
expected or proposed for authorization for these stocks.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated total instances of
take compared to the abundance (measured against both the Navy-
estimated abundance and the SAR) is from 46 to 1,166 percent and 14 to
2,130 percent, respectively (table 16). Given the ranges of these
stocks (many of them are small, resident, island-associated stocks),
this information suggests that a fairly large portion of the
individuals of many of these stocks will be taken but that most
individuals will only be impacted across a smaller to moderate number
of days within the year (1-15), and with no more than several
potentially sequential days, although two stocks (the Oahu stocks of
bottlenose dolphin and pantropical spotted dolphin) have a slightly
higher percentage, suggesting they could be taken up to 23 days within
a year, with perhaps a few more of those days being sequential. We note
that although the percentage is higher for the tropical stock of pygmy
killer whale within the U.S. EEZ (2,130), given (1) the low overall
number of takes (760) and (2) the fact that the small within-U.S. EEZ
abundance is not a static set of individuals, but rather individuals
moving in and out of the U.S. EEZ making it more appropriate to use the
percentage comparison for the total takes versus total abundance--it is
highly unlikely that any individuals would be taken across the number
of days the within-U.S. EEZ percentage suggests (42). While interrupted
feeding bouts are a known response and concern for odontocetes, we also
know that there are often viable alternative habitat options in the
relative vicinity. Regarding the severity of those individual Level B
harassment takes by behavioral disturbance, the duration of any
exposure is expected to be between minutes and hours (i.e., relatively
short) and the received sound levels largely below 172 dB (i.e., of a
lower, or sometimes moderate level, less likely to evoke a severe
response). However, as noted, some of these takes could occur on a fair
number of sequential days for the Oahu stocks of bottlenose dolphin and
pantropical spotted dolphins.
Regarding the severity of TTS takes, they are expected to be low-
level, of short duration, and mostly not in a frequency band that would
be expected

[[Page 68350]]

to interfere significantly with conspecific communication,
echolocation, or other important low-frequency cues. For these same
reasons (low level and frequency band), while a small permanent loss of
hearing sensitivity may include some degree of energetic costs for
compensating or may mean some small loss of opportunities or detection
capabilities, they would be unlikely to impact behaviors,
opportunities, or detection capabilities to a degree that would
interfere with reproductive success or survival of any individuals,
even if accrued to individuals that are also taken by behavioral
harassment at the same time.
Altogether, most of these stocks (all but the Oahu stocks of
bottlenose dolphin and pantropical spotted dolphins) will likely be
taken (at a low to occasionally moderate level) over several days a
year, with some smaller portion of the stock potentially taken on a
more moderate number of days across the year (perhaps up to 15 days for
Fraser's dolphin, though others notably less), some of which could be
across a few sequential days, which is not expected to affect the
reproductive success or survival of individuals. For the Oahu stocks of
bottlenose dolphin and pantropical spotted dolphins, some subset of
individuals could be taken up to 23 days in a year, with some small
number being taken across several sequential days, such that a small
number of individuals could be interrupted during foraging in a manner
and amount such that impacts to the energy budgets of females (from
either losing feeding opportunities or expending considerable energy to
find alternative feeding options) could cause them to forego
reproduction for a year. Energetic impacts to males are generally
meaningless to population rates unless they cause death, and it takes
extreme energy deficits beyond what would ever be likely to result from
these activities to cause the death of an adult marine mammal. As noted
previously, however, foregone reproduction (especially for 1 year,
which is the maximum predicted because the small number anticipated in
any 1 year makes the probability that any individual would be impacted
in this way twice in 7 years very low) has far less of an impact on
population rates than mortality and a small number of instances of
foregone reproduction would not be expected to adversely affect these
two stocks through effects on annual rates of recruitment or survival.
For these reasons, in consideration of all of the effects of the Navy's
activities combined, we have preliminarily determined that the
authorized take proposed would have a negligible impact on all of the
stocks of dolphins found in the vicinity of the HRC.

Dall's Porpoise

In table 20 below for porpoises, we indicate the total annual
mortality, Level A harassment and Level B harassment, and a number
indicating the instances of total take as a percentage of abundance.
Table 20 is updated from table 26 in the 2020 HSTT final rule with the
2022 final SARs. For additional information and analysis supporting the
negligible-impact analysis, see the Odontocetes discussion as well as
the Dall's Porpoise discussion in the Group and Species-Specific
Analyses section of the 2018 HTT final rule, all of which remains
applicable to this proposed rule unless specifically noted.

Table 20--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Porpoises in the HSTT Study Area and Number Indicating the Instances of Total Take as a Percentage
of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental take (not all Total Abundance Instances of total take
takes represent separate individuals, especially for takes -------------------------- as percent of abundance
disturbance) ----------- -------------------------
--------------------------------------------------------------- Total take
Level B harassment Level A harassment as Total take
Species Stock ------------------------------------------------- Total Navy percentage as
takes abundance NMFS SARS of total percentage
TTS (may Mortality (entire in action abundance Navy of total
Behavioral also PTS Tissue study area abundance SAR
disturbance include damage area) in action abundance
disturbance) area
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Dall's porpoise........................ CA/OR/WA................. 14,482 29,891 209 0 0 44,582 2,054 16,498 2,170 270
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the SOCAL take estimates, because of the manner in which the Navy study area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and beyond
and abundance may only be predicted within the U.S. EEZ, while the Navy study area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare
predicted takes to both the abundance estimates for the study area, as well as the SARs (as described in the Estimated Take of Marine Mammals section of the 2018 HSTT final rule).
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.

Below we compile and summarize the information that supports our
determination that the Navy's activities would not adversely affect
Dall's porpoises through effects on annual rates of recruitment or
survival.
Dall's porpoise is not listed under the ESA and the stock status is
considered ``unknown.'' No M/SI or Level A harassment via tissue damage
from exposure to explosives is expected or proposed for authorization
for this stock.
Most Level B harassments to Dall's porpoise from hull-mounted sonar
(MF1) in the HSTT Study Area would result from received levels between
154 and 166 dB SPL (85 percent). While harbor porpoises have been
observed to be especially sensitive to human activity, the same types
of responses have not been observed in Dall's porpoises. Dall's
porpoises are typically notably longer than and weigh more than twice
as much as harbor porpoises making them generally less likely to be
preyed upon and likely differentiating their behavioral repertoire
somewhat from harbor porpoises. Further, they are typically seen in
large groups and feeding aggregations or exhibiting bow-riding
behaviors, which is very different from the group dynamics observed in
the more typically solitary, cryptic harbor porpoises, which are not
often seen bow-riding. For these reasons, Dall's porpoises are not
treated as especially sensitive species (as compared to harbor
porpoises, which have a lower threshold for Level B harassment by
behavioral disturbance and more distant cutoff) but, rather, are
analyzed similarly to other odontocetes. Therefore, the majority of
Level B harassment takes are expected to be in the form of milder
responses compared to higher level exposures. As discussed more fully
in the 2018 HSTT final rule, we anticipate more severe effects from
takes when animals are exposed to higher received levels.

[[Page 68351]]

Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), the number of estimated total instances of
take compared to the abundance (measured against both the Navy-
estimated abundance and the SAR) is 2,170 and 270 percent, respectively
(table 20). Given the range of this stock (up the U.S. West Coast
through Washington and sometimes beyond the U.S. EEZ), this information
suggests that some smaller portion of the individuals of this stock
will be taken, and that some subset of individuals within the stock
will be taken repeatedly within the year (perhaps up to 42 days)--
potentially over a fair number of sequential days, especially where
individuals spend extensive time in the SOCAL range complex. While
interrupted feeding bouts are a known response and concern for
odontocetes, we also know that there are often viable alternative
habitat options in the relative vicinity. Regarding the severity of
those individual Level B harassment takes by behavioral disturbance,
the duration of any exposure is expected to be between minutes and
hours (i.e., relatively short) and the received sound levels largely
below 172 dB (i.e., of a lower, or sometimes moderate level, less
likely to evoke a severe response). However, as noted, some of these
takes could occur on a fair number of sequential days for this stock.
The severity of TTS takes is expected to be low-level, of short
duration, and mostly not in a frequency band that would be expected to
interfere significantly with conspecific communication, echolocation,
or other important low-frequency cues. Therefore, the associated lost
opportunities and capabilities would not be expected to impact
reproduction or survival. For these same reasons (low level and the
likely frequency band), while a small permanent loss of hearing
sensitivity may include some degree of energetic costs for compensating
or may mean some small loss of opportunities or detection capabilities,
the estimated 209 takes by Level A harassment by PTS for Dall's
porpoise would be unlikely to impact behaviors, opportunities, or
detection capabilities to a degree that would interfere with
reproductive success or survival for most individuals. Because of the
high number of PTS takes, however, we acknowledge that a few animals
could potentially incur permanent hearing loss of a higher degree that
could potentially interfere with their successful reproduction and
growth. Given the status of the stock, even if this occurred, it would
not adversely impact rates of recruitment or survival.
Altogether, a portion of this stock will likely be taken (at a low
to occasionally moderate level) over several days a year, and some
smaller portion of the stock is expected to be taken on a relatively
moderate to high number of days across the year, some of which could be
sequential days. Though the majority of impacts are expected to be of a
lower to sometimes moderate severity, the larger number of takes (in
total and for certain individuals) for the Dall's porpoise makes it
more likely (probabilistically) that a small number of individuals
could be interrupted during foraging in a manner and amount such that
impacts to the energy budgets of females (from either losing feeding
opportunities or expending considerable energy to find alternative
feeding options) could cause them to forego reproduction for a year.
Energetic impacts to males are generally meaningless to population
rates unless they cause death, and it takes extreme energy deficits
beyond what would ever be likely to result from these activities to
cause the death of an adult marine mammal. Similarly, we acknowledge
the potential for this to occur to a few individuals out of the 209
total that might incur a higher degree of PTS. As noted previously,
however, foregone reproduction (especially for only 1 year in 7, which
is the maximum predicted because the small number anticipated in any 1
year makes the probability that any individual would be impacted in
this way twice in 7 years very low) has far less of an impact on
population rates than mortality. Further, the small number of instances
of foregone reproduction that could potentially result from PTS and/or
the few repeated, more severe Level B harassment takes by behavioral
disturbance would not be expected to adversely affect the stock through
effects on annual rates of recruitment or survival, especially given
the status of the species (not endangered or threatened; minimum
population of 10,286 just within the U.S. EEZ) and residual PBR of
Dall's porpoise (98.3). For these reasons, in consideration of all of
the effects of the Navy's activities combined, we have preliminarily
determined that the authorized take proposed would have a negligible
impact on Dall's porpoise.

Pinnipeds

In table 21 and table 22 below for pinnipeds, we indicate the total
annual mortality, Level A harassment and Level B harassment, and a
number indicating the instances of total take as a percentage of
abundance. Table 21 and table 22 have been updated from tables 27 and
28 in the 2020 HSTT final rule with the 2022 final SARs, as
appropriate. For additional information and analysis supporting the
negligible-impact analysis, see the Pinnipeds discussion in the Group
and Species-Specific Analyses section of the 2018 HSTT final rule, all
of which remains applicable to this proposed rule unless specifically
noted.

Table 21--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Pinnipeds in the HRC Portion of the HSTT Study Area and Number Indicating the Instances of Total
Take as a Percentage of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental take (not all Total takes Abundance Instance of total take
takes represent separate individuals, especially for ------------------------------------------------ as percent of abundance
disturbance) -------------------------
--------------------------------------------------------------- Total take EEZ take
Level B harassment Level A harassment Total Takes Total Navy Within EEZ as as
Species ------------------------------------------------- takes (within abundance Navy percentage percentage
(entire Navy inside and abundance of total of Navy
Behavioral TTS (may Tissue Mortality study EEZ) outside of (HRC) Navy EEZ
disturbance also include PTS damage area) EEZ (HRC) abundance abundance
disturbance) (HRC) (HRC)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Hawaiian monk seal..................................... 143 62 1 0 0 206 195 169 169 122 115
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the Hawaii take estimates, we compare predicted takes to abundance estimates generated from the same underlying density estimates (as described in the Estimated Take of Marine
Mammals section of the 2018 HSTT final rule), both in and outside of the U.S. EEZ. Because the portion of the Navy's study area inside the U.S. EEZ is generally concomitant with the area
used to generate the abundance estimates in the SARs, and the abundance predicted by the same underlying density estimates is the preferred abundance to use, there is no need to separately
compare the take to the SARs abundance estimate.
Total takes inside and outside U.S. EEZ represent the sum of annual Level A and Level B harassment from training and testing activities.

[[Page 68352]]

Table 22--Annual Estimated Takes by Level B Harassment, Level A Harassment, and Mortality for Pinnipeds in the SOCAL Portion of the HSTT Study Area and Number Indicating the Instances of Total
Take as a Percentage of Stock Abundance
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Instances of indicated types of incidental take (not all Total Abundance Instance of total take
takes represent separate individuals, especially for takes ------------------------ as percent of
disturbance) ---------- abundance
----------------------------------------------------------- -----------------------
Level B harassment Level A Total
--------------------------- harassment Total Navy take as Total
Species Stock ------------------- takes abundance NMFS SARS percentage take as
TTS (may (entire in action abundance of total percentage
Behavioral also Mortality study area Navy of total
disturbance include PTS Tissue area) (SOCAL) abundance SAR
disturbance) damage in action abundance
area
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion........................ U.S........................... 113,419 4,789 87 9 0.71 118,305 4,085 257,606 2,896 46
Guadalupe fur seal......................... Mexico........................ 1,442 15 0 0 0 1,457 1,171 34,187 124 4
Northern fur seal.......................... California.................... 15,167 124 1 0 0 15,292 886 14,050 1,726 109
Harbor seal................................ California.................... 2,450 2,994 8 0 0 5,452 321 30,968 1,698 18
Northern elephant seal..................... California.................... 42,916 17,955 97 2 0 60,970 4,108 187,386 1,484 33
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: For the SOCAL take estimates, because of the manner in which the Navy action area overlaps the ranges of many MMPA stocks (i.e., a stock may range far north to Washington state and
beyond and abundance may only be predicted within the U.S. EEZ, while the Navy action area is limited to Southern California and northern Mexico, but extends beyond the U.S. EEZ), we compare
predicted takes to both the abundance estimates for the action area, as well as the SARs.
For mortality takes there is an annual average of 0.71 California sea lions (i.e., where five takes could potentially occur divided by 7 years to get the annual number of mortalities/serious
injuries).

Below we compile and summarize the information that supports our
determination that the Navy's activities would not adversely affect any
pinnipeds through effects on annual rates of recruitment or survival
for any of the affected species or stocks addressed in this section.
Five M/SI takes of California sea lions are proposed for
authorization and when this mortality is combined with the other human-
caused mortality from other sources, it still falls well below the
insignificance threshold for residual PBR (13,684). A small number of
Level A harassment takes by tissue damage are also proposed for
authorization (nine and two for California sea lions and northern
elephant seals, respectively), which, as discussed in the 2020 HSTT
final rule, could range in impact from minor to something just less
than M/SI that could seriously impact fitness. However, given the
Navy's mitigation, exposure at the closer to the source and more severe
end of the spectrum is less likely. Nevertheless, we cautiously assume
some moderate impact on the individuals that experience these small
numbers of take that could lower the individual's fitness within the
year such that a female (assuming a 50 percent chance of it being a
female) might forego reproduction for 1 year. As noted previously,
foregone reproduction has less of an impact on population rates than
death (especially for only one within 7 years, which is the maximum
predicted because the small number anticipated in any 1 year makes the
probability that any individual would be impacted in this way twice in
7 years very low) and these low numbers of instances (especially
assuming the likelihood that only 50 percent of the takes would affect
females) would not be expected to impact annual rates of recruitment or
survival, especially given the population sizes of these species.
Regarding the magnitude of Level B harassment takes (TTS and
behavioral disturbance), for Hawaiian monk seals and Guadalupe fur
seals, the two species listed under the ESA, the estimated instances of
takes as compared to the stock abundance does not exceed 124 percent,
which suggests that some portion of these two stocks would be taken on
1 to a few days per year. For the remaining stocks, the number of
estimated total instances of take compared to the abundance (measured
against both the Navy-estimated abundance and the SAR) for these stocks
is 1,484 to 2,896 percent and 18 to 46 percent, respectively (table
21). Given the ranges of these stocks (i.e., very large ranges, but
with individuals often staying in the vicinity of haulouts), this
information suggests that some very small portion of the individuals of
these stocks will be taken, but that some subset of individuals within
the stock will be taken repeatedly within the year (perhaps up to 58
days)--potentially over a fair number of sequential days. Regarding the
severity of those individual Level B harassment takes by behavioral
disturbance, the duration of any exposure is expected to be between
minutes and hours (i.e., relatively short) and the received sound
levels largely below 172 dB, which is considered a relatively low to
occasionally moderate level for pinnipeds. However, as noted, some of
these takes could occur on a fair number of sequential days for this
stock.
As described in the 2018 HSTT final rule and 2020 HSTT final rule,
the Hawaii and 4-Islands mitigation areas protect (by not using
explosives and limiting MFAS within) a significant portion of the
designated critical habitat for Hawaiian monk seals in the Main
Hawaiian Islands, including all of it around the islands of Hawaii and
Lanai, most around Maui, and good portions around Molokai and
Kaho'olawe. As discussed, this protection reduces the overall number of
takes and further reduces the severity of effects by minimizing impacts
near pupping beaches and in important foraging habitat.
The severity of TTS takes are expected to be low-level, of short
duration, and mostly not in a frequency band that would be expected to
interfere significantly with conspecific communication, echolocation,
or other important low-frequency cues that would affect the
individual's reproduction or survival. For these same reasons (low
level and frequency band), while a small permanent loss of hearing
sensitivity may include some degree of energetic costs for compensating
or may mean some small loss of opportunities or detection capabilities,
the one to eight estimated Level A harassment takes by PTS for monk
seals, northern fur seals, and harbor seals would be unlikely to impact
behaviors, opportunities, or detection capabilities to a degree that
would interfere with

[[Page 68353]]

reproductive success or survival of any individuals. Because of the
high number of PTS takes for California sea lions and northern elephant
seals (87 and 97, respectively), we acknowledge that a few animals
could potentially incur permanent hearing loss of a higher degree that
could potentially interfere with their successful reproduction and
growth. Given the status of the stocks, even if this occurred, it would
not adversely impact rates of recruitment or survival (residual PBR of
13,684 and 5,108, respectively).
Altogether, an individual Hawaiian monk seal and Guadalupe fur seal
would be taken no more than a few days in any year with none of the
expected take anticipated to affect individual reproduction or
survival, let alone annual rates of recruitment and survival. With all
other stocks, only a very small portion of the stock will be taken in
any manner. Of those taken, some individuals will be taken by Level B
harassment (at a moderate or sometimes low level) over several days a
year, and some smaller portion of those taken will be on a relatively
moderate to high number of days across the year (up to 58), a fair
number of which would likely be sequential days. Though the majority of
impacts are expected to be of a lower to sometimes moderate severity,
the repeated takes over a potentially fair number of sequential days
for some individuals makes it more likely that some number of
individuals could be interrupted during foraging in a manner and amount
such that impacts to the energy budgets of females (from either losing
feeding opportunities or expending considerable energy to find
alternative feeding options) could cause them to forego reproduction
for a year (energetic impacts to males are generally meaningless to
population rates unless they cause death, and it takes extreme energy
deficits beyond what would ever be likely to result from these
activities to cause the death of an adult marine mammal). As noted
previously, however, foregone reproduction (especially for only 1 year
within 7, which is the maximum predicted because the small number
anticipated in any 1 year makes the probability that any individual
would be impacted in this way twice in 7 years very low) has far less
of an impact on population rates than mortality and a relatively small
number of instances of foregone reproduction (as compared to the stock
abundance and residual PBR) would not be expected to adversely affect
the stock through effects on annual rates of recruitment or survival,
especially given the status of these stocks. Accordingly, we do not
anticipate the relatively small number of individual northern fur seals
or harbor seals that might be taken over repeated days within the year
in a manner that results in 1 year of foregone reproduction to
adversely affect the stocks through effects on rates of recruitment or
survival, given the status of the stocks, which are respectively
increasing and stable with abundances and residual PBRs of 14,050/
30,968 and 449/1,598.
For California sea lions, given the very high abundance and
residual PBR (257,606 and 13,684, respectively), as well as the
increasing status of the stock in the presence of similar levels of
Navy activities over past years--the impacts of 0.71 annual
mortalities, potential foregone reproduction for up to nine individuals
in a year taken by tissue damage, and some relatively small number of
individuals taken as a result of repeated behavioral harassment over a
fair number of sequential days are not expected to adversely affect the
stock through effects on annual rates of recruitment or survival.
Similarly, for northern elephant seals, given the very high abundance
and residual PBR (187,386 and 5,108, respectively), as well as the
increasing status of the stock in the presence of similar levels of
Navy activities over past years, the impacts of potential foregone
reproduction for up to two individuals in a year taken by tissue damage
and some relatively small number of individuals taken as a result of
repeated behavioral harassment over a fair number of sequential days
are not expected to adversely affect the stock through effects on
annual rates of recruitment or survival. For these reasons, in
consideration of all of the effects of the Navy's activities combined
(M/SI, Level A harassment, and Level B harassment), we have
preliminarily determined that the authorized take proposed would have a
negligible impact on all pinniped species and stocks.

Preliminary Determination

The 2018 HSTT final rule included a detailed discussion of all of
the anticipated impacts on the affected species and stocks from serious
injury or mortality, Level A harassment, and Level B harassment;
impacts on habitat; and how the Navy's mitigation and monitoring
measures reduce the number and/or severity of adverse effects. We have
evaluated how these impacts as well as an additional proposed take of
two large whales by serious injury or mortality by vessel strike, and
the proposed mitigation measures are expected to combine, annually, to
affect individuals of each species and stock. Those effects were then
evaluated in the context of whether they are reasonably likely to
impact reproductive success or survivorship of individuals and then, if
so, further analyzed to determine whether there would be effects on
annual rates of recruitment or survival that would adversely affect the
species or stock.
As described above, the basis for the negligible impact
determination is the assessment of effects on annual rates of
recruitment and survival. Accordingly, the analysis included in the
2018 HSTT final rule and 2020 HSTT final rule used annual activity
levels, the best available science, and approved methods to predict the
annual impacts to marine mammals, which were then analyzed in the
context of whether each species or stock would incur more than a
negligible impact based on anticipated adverse impacts to annual rates
of recruitment or survival. As we have described above, none of the
factors upon which the conclusions in the 2020 HSTT final rule were
based have changed, with the exception of estimated take by vessel
strike. Therefore, even though this proposed rule includes two
additional takes by vessel strike, little has changed that would change
our 2018 HSTT final rule and subsequent 2020 HSTT final rule analyses,
and it is appropriate to rely on those analyses, as well as the new
information and analysis discussed above, for this proposed rule.
Based on the applicable information and analysis from the 2018 HSTT
final rule and 2020 HSTT final rule, as updated with the information
and analysis contained herein on the potential and likely effects of
the specified activities on the affected marine mammals and their
habitat, and taking into consideration the implementation of the
monitoring and mitigation measures, NMFS preliminarily finds that the
incidental take from the specified activities will have a negligible
impact on all affected marine mammal species and stocks.

Subsistence Harvest of Marine Mammals

There are no subsistence uses or harvest of marine mammals in the
geographic area affected by the specified activities. Therefore, NMFS
has preliminarily determined that the total taking affecting species or
stocks would not have an unmitigable adverse impact on the availability
of such species or stocks for taking for subsistence purposes.

[[Page 68354]]

Classification

Endangered Species Act

There are nine marine mammal species under NMFS jurisdiction that
are listed as endangered or threatened under the ESA with confirmed or
possible occurrence in the HSTT Study Area: blue whale (Eastern and
Central North Pacific stocks), fin whale (CA/OR/WA and Hawaii stocks),
gray whale (Western North Pacific stock), humpback whale (Mexico and
Central America DPSs), sei whale (Eastern North Pacific and Hawaii
stocks), sperm whale (CA/OR/WA and Hawaii stocks), false killer whale
(Main Hawaiian Islands Insular), Hawaiian monk seal (Hawaii stock), and
Guadalupe fur seal (Mexico to California). There is also ESA-designated
critical habitat for Hawaiian monk seals and Main Hawaiian Islands
Insular false killer whales. The Navy consulted with NMFS pursuant to
section 7 of the ESA for HSTT activities. NMFS also consulted
internally on the issuance of the 2018 HSTT regulations and LOAs under
section 101(a)(5)(A) of the MMPA.
NMFS issued a Biological Opinion on December 10, 2018 concluding
that the issuance of the 2018 HSTT final rule and subsequent LOAs are
not likely to jeopardize the continued existence of the threatened and
endangered species under NMFS' jurisdiction and are not likely to
result in the destruction or adverse modification of critical habitat
in the HSTT Study Area. The 2018 Biological Opinion included specified
conditions under which NMFS would be required to reinitiate section 7
consultation. NMFS reviewed these specified conditions for the 2020
HSTT rulemaking and determined that reinitiation of consultation was
not warranted. The incidental take statement that accompanied the 2018
Biological Opinion was amended to cover the 7-year period of the 2020
HSTT rule. The 2018 Biological Opinion for this action is available at
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.
The 2018 Biological Opinion reinitiation clause (2), states that
formal consultation should be reinitiated if ``new information reveals
effects of the agency action that may affect ESA-listed species or
critical habitat in a manner or to an extent not previously
considered.'' Given the new information regarding the recent occurrence
of large whale strikes by naval vessels in the southern California
portion of the HSTT Study Area, as described herein, the Navy has
reinitiated consultation with NMFS pursuant to section 7 of the ESA for
HSTT Study Area activities, and NMFS has also reinitiated consultation
internally on the issuance of these proposed, revised regulations and
LOAs under section 101(a)(5)(A) of the MMPA.

National Marine Sanctuaries Act

Federal agency actions that are likely to injure national marine
sanctuary resources are subject to consultation with the Office of
National Marine Sanctuaries (ONMS) under section 304(d) of the National
Marine Sanctuaries Act (NMSA). There are two national marine
sanctuaries in the HSTT Study Area, the Hawaiian Islands Humpback Whale
National Marine Sanctuary and the Channel Islands National Marine
Sanctuary. NMFS will work with NOAA's ONMS to fulfill our
responsibilities under the NMSA as warranted and will complete any NMSA
requirements prior to a determination on the issuance of the final rule
and LOAs.

National Environmental Policy Act

To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must evaluate our proposed actions and alternatives with respect
to potential impacts on the human environment. NMFS participated as a
cooperating agency on the 2018 HSTT FEIS/OEIS (published on October 26,
2018, https://www.hstteis.com) which evaluated impacts from Navy
training and testing activities in the HSTT Study Area for the
reasonably foreseeable future (including through 2025). In accordance
with 40 CFR 1506.3, NMFS independently reviewed and evaluated the 2018
HSTT FEIS/OEIS and determined that it was adequate and sufficient to
meet our responsibilities under NEPA for the issuance of the 2018 HSTT
final rule and associated LOAs. NMFS therefore adopted the 2018 HSTT
FEIS/OEIS.
In accordance with 40 CFR 1502.9 and the information and analysis
contained in this proposed rule, the Navy and NMFS as a cooperating
agency have made a preliminary determination that this proposed rule
and any subsequent LOAs would not result in significant impacts that
were not fully considered in the 2018 HSTT FEIS/OEIS. As indicated in
this proposed rule, the Navy has made no substantial changes to the
activities nor are there significant new circumstances or information
relevant to environmental concerns or their impacts. NMFS will make a
final NEPA determination prior to a decision whether to issue a final
rule.

Regulatory Flexibility Act

The Office of Management and Budget has determined that this
proposed rule is not significant for purposes of Executive Order 12866.
Pursuant to the Regulatory Flexibility Act (RFA), the Chief Counsel
for Regulation of the Department of Commerce has certified to the Chief
Counsel for Advocacy of the Small Business Administration that this
proposed rule, if adopted, would not have a significant economic impact
on a substantial number of small entities. The RFA requires Federal
agencies to prepare an analysis of a rule's impact on small entities
whenever the agency is required to publish a notice of proposed
rulemaking. However, a Federal agency may certify, pursuant to 5 U.S.C.
605(b), that the action will not have a significant economic impact on
a substantial number of small entities. The Navy is the sole entity
that would be affected by this rulemaking, and the Navy is not a small
governmental jurisdiction, small organization, or small business, as
defined by the RFA. Any requirements imposed by an LOA issued pursuant
to these regulations, and any monitoring or reporting requirements
imposed by these regulations, would be applicable only to the Navy.
NMFS does not expect the issuance of these regulations or the
associated LOAs to result in any impacts to small entities pursuant to
the RFA. Because this action, if adopted, would directly affect the
Navy and not a small entity, NMFS concludes the action would not result
in a significant economic impact on a substantial number of small
entities.

List of Subjects in 50 CFR Part 218

Exports, Fish, Imports, Incidental take, Indians, Labeling, Marine
mammals, Navy, Penalties, Reporting and recordkeeping requirements,
Seafood, Sonar, Transportation.

Dated: September 26, 2023.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine
Fisheries Service.

For reasons set forth in the preamble, NMFS proposes to amend 50
CFR part 218 as follows:

PART 218--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE
MAMMALS

0
1. The authority citation for part 218 continues to read as follows:

[[Page 68355]]

Authority: 16 U.S.C. 1361 et seq.

0
2. Revise subpart H to read as follows:

Subpart H--Taking and Importing Marine Mammals; U.S. Navy's Hawaii-
Southern California Training and Testing (HSTT)

Sec.
218.70 Specified activity and geographical region.
218.71 Effective dates.
218.72 Permissible methods of taking.
218.73 Prohibitions.
218.74 Mitigation requirements.
218.75 Requirements for monitoring and reporting.
218.76 Letters of Authorization.
218.77 Renewals and modifications of Letters of Authorization.
218.78 and 218.79 [Reserved]

Subpart H--Taking and Importing Marine Mammals; U.S. Navy's Hawaii-
Southern California Training and Testing (HSTT)

Sec. 218.70 Specified activity and geographical region.

(a) Regulations in this subpart apply only to the U.S. Navy (Navy)
for the taking of marine mammals that occurs in the area described in
paragraph (b) of this section and that occurs incidental to the
activities listed in paragraph (c) of this section.
(b) The taking of marine mammals by the Navy under this subpart may
be authorized in Letters of Authorization (LOAs) only if it occurs
within the Hawaii-Southern California Training and Testing (HSTT) Study
Area, which includes established operating and warning areas across the
north-central Pacific Ocean, from the mean high tide line in Southern
California west to Hawaii and the International Date Line. The HSTT
Study Area includes the at-sea areas of three existing range complexes,
the Hawaii Range Complex (HRC), the Southern California Range Complex
(SOCAL), and the Silver Strand Training Complex, and overlaps a portion
of the Point Mugu Sea Range (PMSR). Also included in the HSTT Study
Area are Navy pierside locations in Hawaii and Southern California,
Pearl Harbor, San Diego Bay, and the transit corridor on the high seas
where sonar training and testing may occur.
(c) The taking of marine mammals by the Navy is only authorized if
it occurs incidental to the Navy conducting training and testing
activities, including:
(1) Training. (i) Amphibious warfare;
(ii) Anti-submarine warfare;
(iii) Electronic warfare;
(iv) Expeditionary warfare;
(v) Mine warfare;
(vi) Surface warfare; and
(vii) Pile driving.
(2) Testing. (i) Naval Air Systems Command Testing Activities;
(ii) Naval Sea System Command Testing Activities;
(iii) Office of Naval Research Testing Activities; and
(iv) Naval Information Warfare Systems Command.

Sec. 218.71 Effective dates.

Regulations in this subpart are effective from [date of publication
of a final rule in the Federal Register] through December 20, 2025.

Sec. 218.72 Permissible methods of taking.

(a) Under LOAs issued pursuant to Sec. Sec. 216.106 of this
chapter and 218.76, the Holder of the LOAs (hereinafter ``Navy'') may
incidentally, but not intentionally, take marine mammals within the
area described in Sec. 218.70(b) by Level A harassment and Level B
harassment associated with the use of active sonar and other acoustic
sources and explosives as well as serious injury or mortality
associated with vessel strikes and explosives, provided the activity is
in compliance with all terms, conditions, and requirements of these
regulations in this subpart and the applicable LOAs.
(b) The incidental take of marine mammals by the activities listed
in Sec. 218.70(c) is limited to the following species:

Table 1 to Paragraph (b)
------------------------------------------------------------------------
Species Stock
------------------------------------------------------------------------
Blue whale............................. Central North Pacific.
Blue whale............................. Eastern North Pacific.
Bryde's whale.......................... Eastern Tropical Pacific.
Bryde's whale.......................... Hawaii.
Fin whale.............................. CA/OR/WA.
Fin whale.............................. Hawaii.
Humpback whale......................... Central America/Southern
Mexico--CA/OR/WA.
Humpback whale......................... Mainland Mexico--CA/OR/WA.
Humpback whale......................... Hawaii.
Minke whale............................ CA/OR/WA.
Minke whale............................ Hawaii.
Sei whale.............................. Eastern North Pacific.
Sei whale.............................. Hawaii.
Gray whale............................. Eastern North Pacific.
Gray whale............................. Western North Pacific.
Sperm whale............................ CA/OR/WA.
Sperm whale............................ Hawaii.
Dwarf sperm whale...................... Hawaii.
Pygmy sperm whale...................... Hawaii.
Kogia whales........................... CA/OR/WA.
Baird's beaked whale................... CA/OR/WA.
Blainville's beaked whale.............. Hawaii.
Cuvier's beaked whale.................. CA/OR/WA.
Cuvier's beaked whale.................. Hawaii.
Longman's beaked whale................. Hawaii.
Mesoplodon spp......................... CA/OR/WA.
Bottlenose dolphin..................... California Coastal.
Bottlenose dolphin..................... CA/OR/WA Offshore.
Bottlenose dolphin..................... Hawaii Pelagic.
Bottlenose dolphin..................... Kauai & Niihau.
Bottlenose dolphin..................... Oahu.
Bottlenose dolphin..................... 4-Island.

[[Page 68356]]

Bottlenose dolphin..................... Hawaii.
False killer whale..................... Hawaii Pelagic.
False killer whale..................... Main Hawaiian Islands Insular.
False killer whale..................... Northwestern Hawaiian Islands.
Fraser's dolphin....................... Hawaii.
Killer whale........................... Eastern North Pacific (ENP)
Offshore.
Killer whale........................... ENP Transient/West Coast
Transient.
Killer whale........................... Hawaii.
Long-beaked common dolphin............. California.
Melon-headed whale..................... Hawaiian Islands.
Melon-headed whale..................... Kohala Resident.
Northern right whale dolphin........... CA/OR/WA.
Pacific white-sided dolphin............ CA/OR/WA.
Pantropical spotted dolphin............ Hawaii Island.
Pantropical spotted dolphin............ Hawaii Pelagic.
Pantropical spotted dolphin............ Oahu.
Pantropical spotted dolphin............ 4-Island.
Pygmy killer whale..................... Hawaii.
Pygmy killer whale..................... Tropical.
Risso's dolphin........................ CA/OR/WA.
Risso's dolphin........................ Hawaii.
Rough-toothed dolphin.................. Hawaii.
Short-beaked common dolphin............ CA/OR/WA.
Short-finned pilot whale............... CA/OR/WA.
Short-finned pilot whale............... Hawaii.
Spinner dolphin........................ Hawaii Island.
Spinner dolphin........................ Hawaii Pelagic.
Spinner dolphin........................ Kauai & Niihau.
Spinner dolphin........................ Oahu & 4-Island.
Striped dolphin........................ CA/OR/WA.
Striped dolphin........................ Hawaii.
Dall's porpoise........................ CA/OR/WA.
California sea lion.................... U.S.
Guadalupe fur seal..................... Mexico.
Northern fur seal...................... California.
Harbor seal............................ California.
Hawaiian monk seal..................... Hawaii.
Northern elephant seal................. California.
------------------------------------------------------------------------
Note to Table 1: CA/OR/WA = California/Oregon/Washington.

Sec. 218.73 Prohibitions.

Notwithstanding incidental takings contemplated in Sec. 218.72(a)
and authorized by LOAs issued under Sec. Sec. 216.106 of this chapter
and 218.76, no person in connection with the activities listed in Sec.
218.70(c) may:
(a) Violate, or fail to comply with, the terms, conditions, and
requirements of this subpart or an LOA issued under Sec. Sec. 216.106
of this chapter and 218.76;
(b) Take any marine mammal not specified in Sec. 218.72(b);
(c) Take any marine mammal specified in Sec. 218.72(b) in any
manner other than as specified in the LOAs; or
(d) Take a marine mammal specified in Sec. 218.72(b) if NMFS
determines such taking results in more than a negligible impact on the
species or stocks of such marine mammal.

Sec. 218.74 Mitigation requirements.

When conducting the activities identified in Sec. 218.70(c), the
mitigation measures contained in any LOAs issued under Sec. Sec.
216.106 of this chapter and 218.76 must be implemented. These
mitigation measures include, but are not limited to:
(a) Procedural mitigation. Procedural mitigation is mitigation that
the Navy must implement whenever and wherever an applicable training or
testing activity takes place within the HSTT Study Area for each
applicable activity category or stressor category and includes acoustic
stressors (i.e., active sonar, air guns, pile driving, weapons firing
noise), explosive stressors (i.e., sonobuoys, torpedoes, medium-caliber
and large-caliber projectiles, missiles and rockets, bombs, sinking
exercises, mines, anti-swimmer grenades, and mat weave and obstacle
loading), and physical disturbance and strike stressors (i.e., vessel
movement; towed in-water devices; small-, medium-, and large-caliber
non-explosive practice munitions; non-explosive missiles and rockets;
and non-explosive bombs and mine shapes).
(1) Environmental awareness and education. Appropriate Navy
personnel (including civilian personnel) involved in mitigation and
training or testing activity reporting under the specified activities
will complete one or more modules identified in their career path
training plan, as specified in the LOAs.
(2) Active sonar. Active sonar includes low-frequency active sonar,
mid-frequency active sonar, and high-frequency active sonar. For
vessel-based activities, mitigation applies only to sources that are
positively controlled and deployed from manned surface vessels (e.g.,
sonar sources towed from manned surface platforms). For aircraft-based
activities, mitigation applies only to sources that are positively
controlled and deployed from manned aircraft that do not operate at
high altitudes (e.g., rotary-wing aircraft). Mitigation does not apply
to active sonar sources deployed from unmanned aircraft or aircraft
operating at high altitudes (e.g., maritime patrol aircraft).
(i) Number of Lookouts and observation platform--(A) Hull-mounted
sources. One Lookout for

[[Page 68357]]

platforms with space or manning restrictions while underway (at the
forward part of a small boat or ship) and platforms using active sonar
while moored or at anchor (including pierside); and two Lookouts for
platforms without space or manning restrictions while underway (at the
forward part of the ship).
(B) Sources that are not hull-mounted sources. One Lookout on the
ship or aircraft conducting the activity.
(ii) Mitigation zone and requirements. During the activity, at
1,000 yards (yd) Navy personnel must power down 6 decibels (dB), at 500
yd (457.2 m) Navy personnel must power down an additional 4 dB (for a
total of 10 dB), and at 200 yd (182.9 m) Navy personnel must shut down
for low-frequency active sonar >=200 dB and hull-mounted mid-frequency
active sonar; or at 200 yd (182.9 m) Navy personnel must shut down for
low-frequency active sonar <200 dB, mid-frequency active sonar sources
that are not hull-mounted, and high-frequency active sonar.
(A) Prior to activity. Prior to the start of the activity (e.g.,
when maneuvering on station), Navy personnel must observe the
mitigation zone for floating vegetation; if floating vegetation is
observed, Navy personnel must relocate or delay the start of active
sonar transmission until the mitigation zone is clear. Navy personnel
must also observe the mitigation zone for marine mammals; if marine
mammals are observed, Navy personnel must relocate or delay the start
of active sonar transmission.
(B) During the activity for low-frequency active sonar at or above
200 dB and hull-mounted mid-frequency active sonar. During the activity
for low-frequency active sonar at or above 200 dB and hull-mounted mid-
frequency active sonar, Navy personnel must observe the mitigation zone
for marine mammals and power down active sonar transmission by 6 dB if
marine mammals are observed within 1,000 yd (914.4 m) of the sonar
source; power down by an additional 4 dB (for a total of 10 dB total)
if marine mammals are observed within 500 yd (457.2 m) of the sonar
source; and cease transmission if marine mammals are observed within
200 yd (182.9 m) of the sonar source.
(C) During the activity for low-frequency active sonar below 200
dB, mid-frequency active sonar sources that are not hull mounted, and
high-frequency active sonar. During the activity for low-frequency
active sonar below 200 dB, mid-frequency active sonar sources that are
not hull mounted, and high-frequency active sonar, Navy personnel must
observe the mitigation zone for marine mammals and cease active sonar
transmission if marine mammals are observed within 200 yd (182.9 m) of
the sonar source.
(D) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing or powering up active sonar transmission) until
one of the following conditions has been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the sonar source;
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 10 minutes (min) for aircraft-
deployed sonar sources or 30 min for vessel-deployed sonar sources;
(4) Sonar source transit. For mobile activities, the active sonar
source has transited a distance equal to double that of the mitigation
zone size beyond the location of the last sighting; or
(5) Bow-riding dolphins. For activities using hull-mounted sonar
where a dolphin(s) is observed in the mitigation zone, the Lookout
concludes that the dolphin(s) are deliberately closing in on the ship
to ride the ship's bow wave, and are therefore out of the main
transmission axis of the sonar (and there are no other marine mammal
sightings within the mitigation zone).
(3) Air guns--(i) Number of Lookouts and observation platform. One
Lookout positioned on a ship or pierside.
(ii) Mitigation zone and requirements. 150 yd (137.2 m) around the
air gun.
(A) Prior to activity. Prior to the initial start of the activity
(e.g., when maneuvering on station), Navy personnel must observe the
mitigation zone for floating vegetation; if floating vegetation is
observed, Navy personnel must relocate or delay the start until the
mitigation zone is clear. Navy personnel must also observe the
mitigation zone for marine mammals; if marine mammals are observed,
Navy personnel must relocate or delay the start of air gun use.
(B) During activity. During the activity, Navy personnel must
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must cease air gun use.
(C) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing air gun use) until one of the following conditions
has been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the air gun;
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 30 min; or
(4) Air gun transit. For mobile activities, the air gun has
transited a distance equal to double that of the mitigation zone size
beyond the location of the last sighting.
(4) Pile driving. Pile driving and pile extraction sound during
Elevated Causeway System training.
(i) Number of Lookouts and observation platform. One Lookout must
be positioned on the shore, the elevated causeway, or a small boat.
(ii) Mitigation zone and requirements. 100 yd (91.4 m) around the
pile driver.
(A) Prior to activity. Prior to the initial start of the activity
(for 30 min), Navy personnel must observe the mitigation zone for
floating vegetation; if floating vegetation is observed, Navy personnel
must delay the start until the mitigation zone is clear. Navy personnel
also must observe the mitigation zone for marine mammals; if marine
mammals are observed, Navy personnel must delay the start of pile
driving or vibratory pile extraction.
(B) During activity. During the activity, Navy personnel must
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must cease impact pile driving or vibratory
pile extraction.
(C) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing pile driving or pile extraction) until one of the
following conditions has been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the pile driving location; or

[[Page 68358]]

(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 30 minutes.
(5) Weapons firing noise. Weapons firing noise associated with
large-caliber gunnery activities.
(i) Number of Lookouts and observation platform. One Lookout must
be positioned on the ship conducting the firing. Depending on the
activity, the Lookout could be the same as the one provided for under
``Explosive medium-caliber and large-caliber projectiles'' or under
``Small-, medium-, and large-caliber non-explosive practice munitions''
in paragraphs (a)(8)(i) and (a)(18)(i) of this section.
(ii) Mitigation zone and requirements. Thirty degrees on either
side of the firing line out to 70 yd from the muzzle of the weapon
being fired.
(A) Prior to activity. Prior to the start of the activity, Navy
personnel must observe the mitigation zone for floating vegetation; if
floating vegetation is observed, Navy personnel must relocate or delay
the start of weapons firing until the mitigation zone is clear. Navy
personnel must also observe the mitigation zone for marine mammals; if
marine mammals are observed, Navy personnel must relocate or delay the
start of weapons firing.
(B) During activity. During the activity, Navy personnel must
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must cease weapons firing.
(C) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing weapons firing) until one of the following
conditions has been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the firing ship;
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 30 min; or
(4) Firing ship transit. For mobile activities, the firing ship has
transited a distance equal to double that of the mitigation zone size
beyond the location of the last sighting.
(6) Explosive sonobuoys--(i) Number of Lookouts and observation
platform. One Lookout must be positioned in an aircraft or on small
boat. If additional platforms are participating in the activity, Navy
personnel positioned in those assets (e.g., safety observers,
evaluators) must support observing the mitigation zone for applicable
biological resources while performing their regular duties.
(ii) Mitigation zone and requirements. 600 yd (548.6 m) around an
explosive sonobuoy.
(A) Prior to activity. Prior to the initial start of the activity
(e.g., during deployment of a sonobuoy field, which typically lasts 20-
30 min), Navy personnel must observe the mitigation zone for floating
vegetation; if floating vegetation is observed, Navy personnel must
relocate or delay the start of sonobuoy or source/receiver pair
detonations until the mitigation zone is clear. Navy personnel must
conduct passive acoustic monitoring for marine mammals and use
information from detections to assist visual observations. Navy
personnel also must visually observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel must relocate
or delay the start of sonobuoy or source/receiver pair detonations.
(B) During activity. During the activity, Navy personnel must
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must cease sonobuoy or source/receiver pair
detonations.
(C) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing detonations) until one of the following conditions
has been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the sonobuoy; or
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 10 min when the activity
involves aircraft that have fuel constraints (e.g., helicopter), or 30
min when the activity involves aircraft that are not typically fuel
constrained.
(D) After activity. After completion of the activity (e.g., prior
to maneuvering off station), when practical (e.g., when platforms are
not constrained by fuel restrictions or mission-essential follow-on
commitments), Navy personnel must observe for marine mammals in the
vicinity of where detonations occurred; if any injured or dead marine
mammals are observed, Navy personnel must follow established incident
reporting procedures. If additional platforms are supporting this
activity (e.g., providing range clearance), these Navy assets must
assist in the visual observation of the area where detonations
occurred.
(7) Explosive torpedoes--(i) Number of Lookouts and observation
platform. One Lookout positioned in an aircraft. If additional
platforms are participating in the activity, Navy personnel positioned
in those assets (e.g., safety observers, evaluators) must support
observing the mitigation zone for applicable biological resources while
performing their regular duties.
(ii) Mitigation zone and requirements. 2,100 yd around the intended
impact location.
(A) Prior to activity. Prior to the initial start of the activity
(e.g., during deployment of the target), Navy personnel must observe
the mitigation zone for floating vegetation and jellyfish aggregations;
if floating vegetation or jellyfish aggregations are observed, Navy
personnel must relocate or delay the start of firing until the
mitigation zone is clear. Navy personnel must conduct passive acoustic
monitoring for marine mammals and use the information from detections
to assist visual observations. Navy personnel also must visually
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must relocate or delay the start of firing.
(B) During activity. During the activity, Navy personnel must
observe for marine mammals and jellyfish aggregations; if marine
mammals or jellyfish aggregations are observed, Navy personnel must
cease firing.
(C) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing firing) until one of the following conditions has
been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the intended impact location; or
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 10 min when the activity
involves aircraft that have fuel constraints, or 30 min when

[[Page 68359]]

the activity involves aircraft that are not typically fuel constrained.
(D) After activity. After completion of the activity (e.g., prior
to maneuvering off station), Navy personnel must when practical (e.g.,
when platforms are not constrained by fuel restrictions or mission-
essential follow-on commitments), observe for marine mammals in the
vicinity of where detonations occurred; if any injured or dead marine
mammals are observed, Navy personnel must follow established incident
reporting procedures. If additional platforms are supporting this
activity (e.g., providing range clearance), these Navy assets must
assist in the visual observation of the area where detonations
occurred.
(8) Explosive medium-caliber and large-caliber projectiles. Gunnery
activities using explosive medium-caliber and large-caliber
projectiles. Mitigation applies to activities using a surface target.
(i) Number of Lookouts and observation platform. One Lookout must
be on the vessel or aircraft conducting the activity. For activities
using explosive large-caliber projectiles, depending on the activity,
the Lookout could be the same as the one described in ``Weapons firing
noise'' in paragraph (a)(5)(i) of this section. If additional platforms
are participating in the activity, Navy personnel positioned in those
assets (e.g., safety observers, evaluators) must support observing the
mitigation zone for applicable biological resources while performing
their regular duties.
(ii) Mitigation zone and requirements--(A) Air-to-surface
activities. 200 yd (182.9 m) around the intended impact location for
air-to-surface activities using explosive medium-caliber projectiles.
(B) Surface-to-surface activities, medium-caliber. 600 yd (548.6 m)
around the intended impact location for surface-to-surface activities
using explosive medium-caliber projectiles.
(C) Surface-to-surface activities, large-caliber. 1,000 yd (914.4
m) around the intended impact location for surface-to-surface
activities using explosive large-caliber projectiles.
(D) Prior to activity. Prior to the start of the activity (e.g.,
when maneuvering on station), Navy personnel must observe the
mitigation zone for floating vegetation; if floating vegetation is
observed, Navy personnel must relocate or delay the start of firing
until the mitigation zone is clear. Navy personnel also must observe
the mitigation zone for marine mammals; if marine mammals are observed,
Navy personnel must relocate or delay the start of firing.
(E) During activity. During the activity, Navy personnel must
observe for marine mammals; if marine mammals are observed, Navy
personnel must cease firing.
(F) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing firing) until one of the following conditions has
been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the intended impact location;
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 10 min for aircraft-based
firing or 30 min for vessel-based firing; or for activities using
mobile targets, the intended impact location has transited a distance
equal to double that of the mitigation zone size beyond the location of
the last sighting.
(G) After activity. After completion of the activity (e.g., prior
to maneuvering off station), Navy personnel must, when practical (e.g.,
when platforms are not constrained by fuel restrictions or mission-
essential follow-on commitments), observe for marine mammals in the
vicinity of where detonations occurred; if any injured or dead marine
mammals are observed, Navy personnel must follow established incident
reporting procedures. If additional platforms are supporting this
activity (e.g., providing range clearance), these Navy assets must
assist in the visual observation of the area where detonations
occurred.
(9) Explosive missiles and rockets. Aircraft-deployed explosive
missiles and rockets. Mitigation applies to activities using a surface
target.
(i) Number of Lookouts and observation platform. One Lookout must
be positioned in an aircraft. If additional platforms are participating
in the activity, Navy personnel positioned in those assets (e.g.,
safety observers, evaluators) must support observing the mitigation
zone for applicable biological resources while performing their regular
duties.
(ii) Mitigation zone and requirements--(A) Missiles or rockets with
0.6-20 lb net explosive weight. 900 yd (823 m) around the intended
impact location for missiles or rockets with 0.6-20 lb net explosive
weight.
(B) Missiles with 21-500 lb net explosive weight. 2,000 yd (1,828.8
m) around the intended impact location for missiles with 21-500 lb net
explosive weight.
(C) Prior to activity. Prior to the initial start of the activity
(e.g., during a fly-over of the mitigation zone), Navy personnel must
observe the mitigation zone for floating vegetation; if floating
vegetation is observed, Navy personnel must relocate or delay the start
of firing until the mitigation zone is clear. Navy personnel also must
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must relocate or delay the start of firing.
(D) During activity. During the activity, Navy personnel must
observe for marine mammals; if marine mammals are observed, Navy
personnel must cease firing.
(E) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing firing) until one of the following conditions has
been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the intended impact location; or
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 10 min when the activity
involves aircraft that have fuel constraints, or 30 min when the
activity involves aircraft that are not typically fuel constrained.
(F) After activity. After completion of the activity (e.g., prior
to maneuvering off station), Navy personnel must, when practical (e.g.,
when platforms are not constrained by fuel restrictions or mission-
essential follow-on commitments), observe for marine mammals in the
vicinity of where detonations occurred; if any injured or dead marine
mammals are observed, Navy personnel must follow established incident
reporting procedures. If additional platforms are supporting this
activity (e.g., providing range clearance), these Navy assets will
assist in the visual observation of the area where detonations
occurred.
(10) Explosive bombs--(i) Number of Lookouts and observation
platform. One

[[Page 68360]]

Lookout must be positioned in an aircraft conducting the activity. If
additional platforms are participating in the activity, Navy personnel
positioned in those assets (e.g., safety observers, evaluators) must
support observing the mitigation zone for applicable biological
resources while performing their regular duties.
(ii) Mitigation zone and requirements. 2,500 yd (2,286 m) around
the intended target.
(A) Prior to activity. Prior to the initial start of the activity
(e.g., when arriving on station), Navy personnel must observe the
mitigation zone for floating vegetation; if floating vegetation is
observed, Navy personnel must relocate or delay the start of bomb
deployment until the mitigation zone is clear. Navy personnel also must
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must relocate or delay the start of bomb
deployment.
(B) During activity. During the activity (e.g., during target
approach), Navy personnel must observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel must cease bomb
deployment.
(C) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing bomb deployment) until one of the following
conditions has been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the intended target;
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 10 min; or for activities using
mobile targets, the intended target has transited a distance equal to
double that of the mitigation zone size beyond the location of the last
sighting.
(D) After activity. After completion of the activity (e.g., prior
to maneuvering off station), Navy personnel must, when practical (e.g.,
when platforms are not constrained by fuel restrictions or mission-
essential follow-on commitments), observe for marine mammals in the
vicinity of where detonations occurred; if any injured or dead marine
mammals are observed, Navy personnel must follow established incident
reporting procedures. If additional platforms are supporting this
activity (e.g., providing range clearance), these Navy assets must
assist in the visual observation of the area where detonations
occurred.
(11) Sinking exercises--(i) Number of Lookouts and observation
platform. Two Lookouts (one must be positioned in an aircraft and one
must be positioned on a vessel). If additional platforms are
participating in the activity, Navy personnel positioned in those
assets (e.g., safety observers, evaluators) must support observing the
mitigation zone for applicable biological resources while performing
their regular duties.
(ii) Mitigation zone and requirements. 2.5 nautical miles (nmi)
around the target ship hulk.
(A) Prior to activity. Prior to the initial start of the activity
(90 min prior to the first firing), Navy personnel must conduct aerial
observations of the mitigation zone for floating vegetation and
jellyfish aggregations; if floating vegetation or jellyfish
aggregations are observed, Navy personnel must delay the start of
firing until the mitigation zone is clear. Navy personnel also must
conduct aerial observations of the mitigation zone for marine mammals;
if marine mammals are observed, Navy personnel must delay the start of
firing.
(B) During activity. During the activity, Navy personnel must
conduct passive acoustic monitoring for marine mammals and use the
information from detections to assist visual observations. Navy
personnel must visually observe the mitigation zone for marine mammals
from the vessel; if marine mammals are observed, Navy personnel must
cease firing. Immediately after any planned or unplanned breaks in
weapons firing of longer than 2 hours, Navy personnel must observe the
mitigation zone for marine mammals from the aircraft and vessel; if
marine mammals are observed, Navy personnel must delay recommencement
of firing.
(C) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing firing) until one of the following conditions has
been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the target ship hulk; or
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 30 minutes.
(D) After activity. After completion of the activity (for 2 hours
after sinking the vessel or until sunset, whichever comes first), Navy
personnel must observe for marine mammals in the vicinity of where
detonations occurred; if any injured or dead marine mammals are
observed, Navy personnel must follow established incident reporting
procedures. If additional platforms are supporting this activity (e.g.,
providing range clearance), these Navy assets will assist in the visual
observation of the area where detonations occurred.
(12) Explosive mine countermeasure and neutralization activities--
(i) Number of Lookouts and observation platform--(A) Smaller mitigation
zone. One Lookout must be positioned on a vessel or in an aircraft when
implementing the smaller mitigation zone.
(B) Larger mitigation zone. Two Lookouts (one must be positioned in
an aircraft and one must be on a small boat) when implementing the
larger mitigation zone.
(C) Additional platforms. If additional platforms are participating
in the activity, Navy personnel positioned in those assets (e.g.,
safety observers, evaluators) must support observing the mitigation
zone for applicable biological resources while performing their regular
duties.
(ii) Mitigation zone and requirements. (A) Activities using 0.1-5
lb net explosive weight. 600 yd (548.6 m) around the detonation site
for activities using 0.1-5 lb net explosive weight.
(B) Activities using 6-650 lb net explosive weight. 2,100 yd
(1,920.2 m) around the detonation site for activities using 6-650 lb
net explosive weight (including high explosive target mines).
(C) Prior to activity. Prior to the initial start of the activity
(e.g., when maneuvering on station; typically, 10 min when the activity
involves aircraft that have fuel constraints, or 30 min when the
activity involves aircraft that are not typically fuel constrained),
Navy personnel must observe the mitigation zone for floating
vegetation; if floating vegetation is observed, Navy personnel must
relocate or delay the start of detonations until the mitigation zone is
clear. Navy personnel also must observe the mitigation zone for marine
mammals; if marine mammals are observed, Navy personnel must relocate
or delay the start of detonations.
(D) During activity. During the activity, Navy personnel must
observe the mitigation zone for marine mammals, concentrations of
seabirds,

[[Page 68361]]

and individual foraging seabirds; if marine mammals, concentrations of
seabirds, or individual foraging seabirds are observed, Navy personnel
must cease detonations.
(E) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity or a sighting of seabird
concentrations or individual foraging seabirds during the activity.
Navy personnel must allow a sighted animal to leave the mitigation zone
prior to the initial start of the activity (by delaying the start) or
during the activity (by not recommencing detonations) until one of the
following conditions has been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to detonation site; or
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 10 min when the activity
involves aircraft that have fuel constraints, or 30 min when the
activity involves aircraft that are not typically fuel constrained.
(F) After activity. After completion of the activity (typically 10
min when the activity involves aircraft that have fuel constraints, or
30 min when the activity involves aircraft that are not typically fuel
constrained), Navy personnel must observe for marine mammals in the
vicinity of where detonations occurred; if any injured or dead marine
mammals are observed, Navy personnel must follow established incident
reporting procedures. If additional platforms are supporting this
activity (e.g., providing range clearance), these Navy assets must
assist in the visual observation of the area where detonations
occurred.
(13) Explosive mine neutralization activities involving Navy
divers--(i) Number of Lookouts and observation platform--(A) Smaller
mitigation zone. Two Lookouts (two small boats with one Lookout each,
or one Lookout must be on a small boat and one must be in a rotary-wing
aircraft) when implementing the smaller mitigation zone.
(B) Larger mitigation zone. Four Lookouts (two small boats with two
Lookouts each), and a pilot or member of an aircrew must serve as an
additional Lookout if aircraft are used during the activity, when
implementing the larger mitigation zone.
(C) Divers. All divers placing the charges on mines will support
the Lookouts while performing their regular duties and will report
applicable sightings to their supporting small boat or Range Safety
Officer.
(D) Additional platforms. If additional platforms are participating
in the activity, Navy personnel positioned in those assets (e.g.,
safety observers, evaluators) must support observing the mitigation
zone for applicable biological resources while performing their regular
duties.
(ii) Mitigation zone and requirements--(A) Activities under
positive control using 0.1-20 lb net explosive weight. 500 yd (457.2 m)
around the detonation site during activities under positive control
using 0.1-20 lb net explosive weight.
(B) Activities under positive control using 21-60 lb net explosive
weight charges. 1,000 yd (914.4 m) around the detonation site during
all activities using time-delay fuses (0.1-29 lb net explosive weight)
and during activities under positive control using 21-60 lb net
explosive weight charges.
(C) Prior to activity. Prior to the initial start of the activity
(e.g., when maneuvering on station for activities under positive
control; 30 min for activities using time-delay firing devices), Navy
personnel must observe the mitigation zone for floating vegetation; if
floating vegetation is observed, Navy personnel must relocate or delay
the start of detonations or fuse initiation until the mitigation zone
is clear. Navy personnel also must observe the mitigation zone for
marine mammals; if marine mammals are observed, Navy personnel must
relocate or delay the start of detonations or fuse initiation.
(D) During activity. During the activity, Navy personnel must
observe the mitigation zone for marine mammals, concentrations of
seabirds, and individual foraging seabirds (in the water and not on
shore); if marine mammals, concentrations of seabirds, or individual
foraging seabirds are observed, Navy personnel must cease detonations
or fuse initiation. To the maximum extent practicable depending on
mission requirements, safety, and environmental conditions, Navy
personnel must position boats near the mid-point of the mitigation zone
radius (but outside of the detonation plume and human safety zone),
must position themselves on opposite sides of the detonation location
(when two boats are used), and must travel in a circular pattern around
the detonation location with one Lookout observing inward toward the
detonation site and the other observing outward toward the perimeter of
the mitigation zone. If used, Navy aircraft must travel in a circular
pattern around the detonation location to the maximum extent
practicable. Navy personnel must not set time-delay firing devices
(0.1-29 lb net explosive weight) to exceed 10 minutes.
(E) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity or a sighting of seabird
concentrations or individual foraging seabirds during the activity.
Navy personnel must allow a sighted animal to leave the mitigation zone
prior to the initial start of the activity (by delaying the start) or
during the activity (by not recommencing detonations) until one of the
following conditions has been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the detonation site; or
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 10 min during activities under
positive control with aircraft that have fuel constraints, or 30 min
during activities under positive control with aircraft that are not
typically fuel constrained and during activities using time-delay
firing devices.
(F) After activity. After completion of an activity (for 30 min),
the Navy must observe for marine mammals for 30 minutes. Navy personnel
must observe for marine mammals in the vicinity of where detonations
occurred; if any injured or dead marine mammals are observed, Navy
personnel must follow established incident reporting procedures. If
additional platforms are supporting this activity (e.g., providing
range clearance), these Navy assets must assist in the visual
observation of the area where detonations occurred.
(14) Maritime security operations--anti-swimmer grenades--(i)
Number of Lookouts and observation platform. One Lookout must be
positioned on the small boat conducting the activity. If additional
platforms are participating in the activity, Navy personnel positioned
in those assets (e.g., safety observers, evaluators) must support
observing the mitigation zone for applicable biological resources while
performing their regular duties.
(ii) Mitigation zone and requirements. 200 yd (182.9 m) around the
intended detonation location.
(A) Prior to activity. Prior to the initial start of the activity
(e.g., when maneuvering on station), Navy personnel must observe the
mitigation zone for floating vegetation; if floating vegetation is
observed, Navy personnel

[[Page 68362]]

must relocate or delay the start of detonations until the mitigation
zone is clear. Navy personnel also must observe the mitigation zone for
marine mammals; if marine mammals are observed, Navy personnel must
relocate or delay the start of detonations.
(B) During activity. During the activity, Navy personnel must
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must cease detonations.
(C) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing detonations) until one of the following conditions
has been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the intended detonation location;
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 30 min; or
(4) Detonation location transit. The intended detonation location
has transited a distance equal to double that of the mitigation zone
size beyond the location of the last sighting.
(D) After activity. After completion of the activity (e.g., prior
to maneuvering off station), Navy personnel must, when practical (e.g.,
when platforms are not constrained by fuel restrictions or mission-
essential follow-on commitments), observe for marine mammals in the
vicinity of where detonations occurred; if any injured or dead marine
mammals are observed, Navy personnel must follow established incident
reporting procedures. If additional platforms are supporting this
activity (e.g., providing range clearance), these Navy assets will
assist in the visual observation of the area where detonations
occurred.
(15) Underwater demolition multiple charge--mat weave and obstacle
loading exercises--(i) Number of Lookouts and observation platform. Two
Lookouts (one must be positioned on a small boat and one must be
positioned on shore from an elevated platform). If additional platforms
are participating in the activity, Navy personnel positioned in those
assets (e.g., safety observers, evaluators) must support observing the
mitigation zone for applicable biological resources while performing
their regular duties.
(ii) Mitigation zone and requirements. 700 yd (640.1 m) around the
intended detonation location.
(A) Prior to activity. Prior to the initial start of the activity,
or 30 min prior to the first detonation, the Lookout positioned on a
small boat must observe the mitigation zone for floating vegetation and
marine mammals; if floating vegetation or marine mammals are observed,
Navy personnel must delay the start of detonations until the mitigation
zone is clear. For 10 min prior to the first detonation, the Lookout
positioned on shore must use binoculars to observe the mitigation zone
for marine mammals; if marine mammals are observed, Navy personnel must
delay the start of detonations.
(B) During activity. During the activity, Navy personnel must
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must cease detonations.
(C) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing detonations) until one of the following conditions
has been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the detonation location; or
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 10 min (as determined by the
Navy shore observer).
(D) After activity. After completion of the activity (for 30 min),
the Lookout positioned on a small boat must observe for marine mammals
in the vicinity of where detonations occurred; if any injured or dead
marine mammals are observed, Navy personnel must follow established
incident reporting procedures. If additional platforms are supporting
this activity (e.g., providing range clearance), these Navy assets must
assist in the visual observation of the area where detonations
occurred.
(16) Vessel movement. The mitigation will not be applied if: the
vessel's safety is threatened; the vessel is restricted in its ability
to maneuver (e.g., during launching and recovery of aircraft or landing
craft, during towing activities, when mooring); the vessel is operated
autonomously; or when impracticable based on mission requirements
(e.g., during Amphibious Assault--Battalion Landing exercise).
(i) Number of Lookouts and observation platform. One Lookout must
be on the vessel that is underway.
(ii) Mitigation zone and requirements--(A) Whales. 500 yd (457.2 m)
around whales.
(B) Marine mammals other than whales. 200 yd (182.9 m) around all
other marine mammals (except bow-riding dolphins and pinnipeds hauled
out on man-made navigational structures, port structures, and vessels).
(iii) During the activity. When underway, Navy personnel must
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must maneuver (which may include reducing
speed as the mission or circumstances allow) to maintain distance.
(iv) Incident reporting procedures. If a marine mammal vessel
strike occurs, Navy personnel must follow the established incident
reporting procedures.
(v) Post-strike alerts. Navy personnel must send alerts to Navy
vessels of increased risk of strike following any reported Navy vessel
strike in the HSTT Study Area.
(vi) Large whale aggregation alerts. Navy personnel must issue
real-time notifications to Navy vessels of large whale aggregations
(four or more whales) within 1 nmi (1.9 km) of a Navy vessel in the
area between 32-33 degrees North and 117.2-119.5 degrees West.
(17) Towed in-water devices. Mitigation applies to devices that are
towed from a manned surface platform or manned aircraft. The mitigation
will not be applied if the safety of the towing platform or in-water
device is threatened.
(i) Number of Lookouts and observation platform. One Lookout must
be positioned on a manned towing platform.
(ii) Mitigation zone and requirements. 250 yd (228.6 m) around
marine mammals.
(iii) During the activity. During the activity (i.e., when towing
an in-water device), Navy personnel must observe the mitigation zone
for marine mammals; if marine mammals are observed, Navy personnel must
maneuver to maintain distance.
(18) Small-, medium-, and large-caliber non-explosive practice
munitions. Mitigation applies to activities using a surface target.
(i) Number of Lookouts and observation platform. One Lookout must

[[Page 68363]]

be positioned on the platform conducting the activity. Depending on the
activity, the Lookout could be the same as the one described for
``Weapons firing noise'' in paragraph (a)(5)(i) of this section.
(ii) Mitigation zone and requirements. 200 yd (182.9 m) around the
intended impact location.
(A) Prior to activity. Prior to the start of the activity (e.g.,
when maneuvering on station), Navy personnel must observe the
mitigation zone for floating vegetation; if floating vegetation is
observed, Navy personnel must relocate or delay the start of firing
until the mitigation zone is clear. Navy personnel also must observe
the mitigation zone for marine mammals; if marine mammals are observed,
Navy personnel must relocate or delay the start of firing.
(B) During activity. During the activity, Navy personnel must
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must cease firing.
(C) Commencement/recommencement conditions after a marine mammal
sighting before or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing firing) until one of the following conditions has
been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the intended impact location;
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 10 min for aircraft-based
firing or 30 min for vessel-based firing; or
(4) Impact location transit. For activities using a mobile target,
the intended impact location has transited a distance equal to double
that of the mitigation zone size beyond the location of the last
sighting.
(19) Non-explosive missiles and rockets. Aircraft-deployed non-
explosive missiles and rockets. Mitigation applies to activities using
a surface target.
(i) Number of Lookouts and observation platform. One Lookout must
be positioned in an aircraft.
(ii) Mitigation zone and requirements. 900 yd around the intended
impact location.
(A) Prior to activity. Prior to the initial start of the activity
(e.g., during a fly-over of the mitigation zone), Navy personnel must
observe the mitigation zone for floating vegetation; if floating
vegetation is observed, Navy personnel must relocate or delay the start
of firing until the mitigation zone is clear. Navy personnel also must
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must relocate or delay the start of firing.
(B) During activity. During the activity, Navy personnel must
observe the mitigation zone for marine mammals; if marine mammals are
observed, Navy personnel must cease firing.
(C) Commencement/recommencement conditions after a marine mammal
sighting prior to or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing firing) until one of the following conditions has
been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the intended impact location; or
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 10 min when the activity
involves aircraft that have fuel constraints, or 30 min when the
activity involves aircraft that are not typically fuel constrained.
(20) Non-explosive bombs and mine shapes. Non-explosive bombs and
non-explosive mine shapes during mine laying activities.
(i) Number of Lookouts and observation platform. One Lookout must
be positioned in an aircraft.
(ii) Mitigation zone and requirements. 1,000 yd (914.4 m) around
the intended target.
(A) Prior to activity. Prior to the initial start of the activity
(e.g., when arriving on station), Navy personnel must observe the
mitigation zone for floating vegetation; if floating vegetation is
observed, Navy personnel must relocate or delay the start of bomb
deployment or mine laying until the mitigation zone is clear. Navy
personnel also must observe the mitigation zone for marine mammals; if
marine mammals are observed, Navy personnel must relocate or delay the
start of bomb deployment or mine laying.
(B) During activity. During the activity (e.g., during approach of
the target or intended minefield location), Navy personnel must observe
the mitigation zone for marine mammals and, if marine mammals are
observed, Navy personnel must cease bomb deployment or mine laying.
(C) Commencement/recommencement conditions after a marine mammal
sighting prior to or during the activity. Navy personnel must allow a
sighted marine mammal to leave the mitigation zone prior to the initial
start of the activity (by delaying the start) or during the activity
(by not recommencing bomb deployment or mine laying) until one of the
following conditions has been met:
(1) Observed exiting. The animal is observed exiting the mitigation
zone;
(2) Thought to have exited. The animal is thought to have exited
the mitigation zone based on a determination of its course, speed, and
movement relative to the intended target or minefield location;
(3) Clear from additional sightings. The mitigation zone has been
clear from any additional sightings for 10 min; or
(4) Target transit. For activities using mobile targets, the
intended target has transited a distance equal to double that of the
mitigation zone size beyond the location of the last sighting.
(b) Mitigation areas. In addition to procedural mitigation, Navy
personnel must implement mitigation measures within mitigation areas to
avoid or reduce potential impacts on marine mammals.
(1) Mitigation areas for marine mammals in the Hawaii Range Complex
for sonar, explosives, and vessel strikes--(i) Mitigation area
requirements--(A) Hawaii Island Mitigation Area (year-round)--(1) MF1
surface ship hull-mounted mid-frequency active sonar, MF4 dipping
sonar, or explosives. Except as provided in paragraph (b)(1)(i)(A)(2)
of this section, Navy personnel must not conduct more than 300 hours of
MF1 surface ship hull-mounted mid-frequency active sonar or 20 hours of
MF4 dipping sonar annually, or use explosives that could potentially
result in takes of marine mammals during training and testing.
(2) National security exception. Should national security require
conduct of more than 300 hours of MF1 surface ship hull-mounted mid-
frequency active sonar or 20 hours of MF4 dipping sonar, or use of
explosives that could potentially result in the take of marine mammals
during training or testing, Naval units must obtain permission from the
appropriate designated Command authority prior to commencement of the
activity. Navy personnel must provide NMFS with advance notification
and include the

[[Page 68364]]

information (e.g., sonar hours or explosives usage) in its annual
activity reports submitted to NMFS.
(B) 4-Islands Region Mitigation Area (November 15-April 15 for
active sonar; year-round for explosives)--(1) MF1 surface ship hull-
mounted mid-frequency active sonar or explosives. Except as provided in
paragraph (b)(1)(i)(B)(2) of this section, Navy personnel must not use
MF1 surface ship hull-mounted mid-frequency active sonar or explosives
that could potentially result in takes of marine mammals during
training and testing.
(2) National security exception. Should national security require
use of MF1 surface ship hull-mounted mid-frequency active sonar or
explosives that could potentially result in the take of marine mammals
during training or testing, Naval units must obtain permission from the
appropriate designated Command authority prior to commencement of the
activity. Navy personnel must provide NMFS with advance notification
and include the information (e.g., sonar hours or explosives usage) in
its annual activity reports submitted to NMFS.
(C) Humpback Whale Special Reporting Areas (December 15-April 15).
Navy personnel must report the total hours of surface ship hull-mounted
mid-frequency active sonar used in the special reporting areas in its
annual training and testing activity reports submitted to NMFS.
(D) Humpback Whale Awareness Notification Message Area (November-
April)--(1) Seasonal awareness notification message. Navy personnel
must issue a seasonal awareness notification message to alert ships and
aircraft operating in the area to the possible presence of
concentrations of large whales, including humpback whales.
(2) Vessel instruction. To maintain safety of navigation and to
avoid interactions with large whales during transits, Navy personnel
must instruct vessels to remain vigilant to the presence of large whale
species (including humpback whales).
(3) Awareness notification message use. Platforms must use the
information from the awareness notification message to assist their
visual observation of applicable mitigation zones during training and
testing activities and to aid in the implementation of procedural
mitigation.
(ii) [Reserved]
(2) Mitigation areas for marine mammals in the southern California
portion of the study area for sonar, explosives, and vessel strikes--
(i) Mitigation area requirements--(A) San Diego Arc, San Nicolas
Island, and Santa Monica/Long Beach Mitigation Areas (June 1-October
31)--(1) MF1 surface ship hull-mounted mid-frequency active sonar.
Except as provided in paragraph (b)(2)(i)(A)(2) of this section, Navy
personnel must not conduct more than a total of 200 hours of MF1
surface ship hull-mounted mid-frequency active sonar in the combined
areas, excluding normal maintenance and systems checks, during training
and testing.
(2) National security exception. Should national security require
conduct of more than 200 hours of MF1 surface ship hull-mounted mid-
frequency active sonar in the combined areas during training and
testing (excluding normal maintenance and systems checks), Naval units
must obtain permission from the appropriate designated Command
authority prior to commencement of the activity. Navy personnel must
provide NMFS with advance notification and include the information
(e.g., sonar hours) in its annual activity reports submitted to NMFS.
(3) Explosives in San Diego Arc Mitigation Area. Except as provided
in paragraph (b)(2)(i)(A)(4) of this section, within the San Diego Arc
Mitigation Area, Navy personnel must not use explosives that could
potentially result in the take of marine mammals during large-caliber
gunnery, torpedo, bombing, and missile (including 2.75-inch rockets)
activities during training and testing.
(4) National security exception. Should national security require
use of explosives that could potentially result in the take of marine
mammals during large-caliber gunnery, torpedo, bombing, and missile
(including 2.75-inch rockets) activities during training or testing
within the San Diego Arc Mitigation Area, Naval units must obtain
permission from the appropriate designated Command authority prior to
commencement of the activity. Navy personnel must provide NMFS with
advance notification and include the information (e.g., explosives
usage) in its annual activity reports submitted to NMFS.
(5) Explosives in San Nicolas Island Mitigation Area. Except as
provided in paragraph (b)(2)(i)(A)(6) of this section, within the San
Nicolas Island Mitigation Area, Navy personnel must not use explosives
that could potentially result in the take of marine mammals during mine
warfare, large-caliber gunnery, torpedo, bombing, and missile
(including 2.75-inch rockets) activities during training.
(6) National security exception. Should national security require
use of explosives that could potentially result in the take of marine
mammals during mine warfare, large-caliber gunnery, torpedo, bombing,
and missile (including 2.75-inch rockets) activities during training in
the San Nicolas Island Mitigation Area, Naval units must obtain
permission from the appropriate designated Command authority prior to
commencement of the activity. Navy personnel must provide NMFS with
advance notification and include the information (e.g., explosives
usage) in its annual activity reports submitted to NMFS.
(7) Explosives in the Santa Monica/Long Beach Mitigation Area.
Except as provided in paragraph (b)(2)(i)(A)(8) of this section, within
the Santa Monica/Long Beach Mitigation Area, Navy personnel must not
use explosives that could potentially result in the take of marine
mammals during mine warfare, large-caliber gunnery, torpedo, bombing,
and missile (including 2.75-inch rockets) activities during training
and testing.
(8) National security exception. Should national security require
use of explosives that could potentially result in the take of marine
mammals during mine warfare, large-caliber gunnery, torpedo, bombing,
and missile (including 2.75-inch rockets) activities during training or
testing in the Santa Monica/Long Beach Mitigation Area, Naval units
must obtain permission from the appropriate designated Command
authority prior to commencement of the activity. Navy personnel must
provide NMFS with advance notification and include the information
(e.g., explosives usage) in its annual activity reports submitted to
NMFS.
(B) Santa Barbara Island Mitigation Area (year-round)--(1) MF1
surface ship hull-mounted mid-frequency active sonar or explosives.
Except as provided in paragraph (b)(2)(i)(B)(2) of this section, Navy
personnel must not use MF1 surface ship hull-mounted mid-frequency
active sonar during training or testing, or explosives that could
potentially result in the take of marine mammals during medium-caliber
or large-caliber gunnery, torpedo, bombing, and missile (including
2.75-inch rockets) activities during training.
(2) National security exception. Should national security require
use of MF1 surface ship hull-mounted mid-frequency active sonar during
training or testing, or explosives that could potentially result in the
take of marine mammals during medium-caliber or large-caliber gunnery,
torpedo, bombing,

[[Page 68365]]

and missile (including 2.75-inch rockets) activities during training,
Naval units must obtain permission from the appropriate designated
Command authority prior to commencement of the activity. Navy personnel
must provide NMFS with advance notification and include the information
(e.g., sonar hours or explosives usage) in its annual activity reports
submitted to NMFS.
(C) Spring Large Whale Awareness Notification Message--(1)
Awareness notification message. Navy personnel must issue an awareness
notification message to alert ships and aircraft operating in the area
to the possible presence of concentrations of large whales, including
blue whales, fin whales, and humpback whales.
(2) Applicable period. This message must apply to a period that is
based on predicted oceanographic conditions for a given year.
(3) Marine mammals and vessel transit. To maintain safety of
navigation and to avoid interactions with large whales during transits,
Navy personnel must emphasize to vessels that when a marine mammal is
spotted, this may be an indicator that additional marine mammals are
present nearby, and increased vigilance and awareness of Navy personnel
is warranted.
(4) Platform use of message. Platforms must use the information
from the awareness notification messages to assist their visual
observation of applicable mitigation zones during training and testing
activities and to aid in the implementation of procedural mitigation.
(D) Gray Whale (November-March) and Fin Whale (November-May)
Awareness Notification Message Areas--(1) Seasonal awareness message.
Navy personnel must issue a seasonal awareness notification message to
alert ships and aircraft operating in the area to the possible presence
of concentrations of large whales, including gray whales, and fin
whales.
(2) Marine mammals and vessel transit. To maintain safety of
navigation and to avoid interactions with large whales during transits,
Navy personnel must instruct vessels to remain vigilant to the presence
of large whale species.
(3) Platform use of message. Platforms must use the information
from the awareness notification messages to assist their visual
observation of applicable mitigation zones during training and testing
activities and to aid in the implementation of procedural mitigation.
(ii) [Reserved]

Sec. 218.75 Requirements for monitoring and reporting.

(a) Unauthorized take. Navy personnel must notify NMFS immediately
(or as soon as operational security considerations allow) if the
specified activity identified in Sec. 218.70 is thought to have
resulted in the mortality or serious injury of any marine mammals, or
in any Level A harassment or Level B harassment take of marine mammals
not identified in this subpart.
(b) Monitoring and reporting under the LOAs. The Navy must conduct
all monitoring and reporting required under the LOAs, including abiding
by the HSTT Study Area monitoring program. Details on program goals,
objectives, project selection process, and current projects are
available at www.navymarinespeciesmonitoring.us.
(c) Notification of injured, live stranded, or dead marine mammals.
The Navy must consult the Notification and Reporting Plan, which sets
out notification, reporting, and other requirements when dead, injured,
or live stranded marine mammals are detected. The Notification and
Reporting Plan is available at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.
(d) Changes in Lookout Policies. The Navy must report changes in
its Lookout policies to NMFS as soon as practicable after a change is
made.
(e) Annual HSTT Study Area marine species monitoring report. The
Navy must submit an annual report of the HSTT Study Area monitoring
describing the implementation and results from the previous calendar
year. Data collection methods must be standardized across range
complexes and study areas to allow for comparison in different
geographic locations. The report must be submitted to the Director,
Office of Protected Resources, NMFS, either within 3 months after the
end of the calendar year, or within 3 months after the conclusion of
the monitoring year, to be determined by the Adaptive Management
process. This report will describe progress of knowledge made with
respect to intermediate scientific objectives within the HSTT Study
Area associated with the Integrated Comprehensive Monitoring Program
(ICMP). Similar study questions must be treated together so that
progress on each topic can be summarized across all Navy ranges. The
report need not include analyses and content that does not provide
direct assessment of cumulative progress on the monitoring plan study
questions. As an alternative, the Navy may submit a multi-Range Complex
annual Monitoring Plan report to fulfill this requirement. Such a
report will describe progress of knowledge made with respect to
monitoring study questions across multiple Navy ranges associated with
the ICMP. Similar study questions must be treated together so that
progress on each topic can be summarized across multiple Navy ranges.
The report need not include analyses and content that does not provide
direct assessment of cumulative progress on the monitoring study
question. This will continue to allow the Navy to provide a cohesive
monitoring report covering multiple ranges (as per ICMP goals), rather
than entirely separate reports for the HSTT, Gulf of Alaska, Mariana
Islands, and Northwest Study Areas.
(f) Annual HSTT Study Area training exercise report and testing
activity report. Each year, the Navy must submit two preliminary
reports (Quick Look Report) detailing the status of authorized sound
sources within 21 days after the anniversary of the date of issuance of
each LOA to the Director, Office of Protected Resources, NMFS. Each
year, the Navy must submit detailed reports to the Director, Office of
Protected Resources, NMFS, within 3 months after the 1-year anniversary
of the date of issuance of the LOA. The HSTT annual Training Exercise
Report and Testing Activity Report can be consolidated with other
exercise reports from other range complexes in the Pacific Ocean for a
single Pacific Exercise Report, if desired. The annual reports must
contain information on major training exercises (MTEs), Sinking
Exercise (SINKEX) events, and a summary of all sound sources used,
including within specific mitigation reporting areas, as described in
paragraph (e)(3) through (5) of this section. The analysis in the
detailed reports must be based on the accumulation of data from the
current year's report and data collected from previous reports. The
detailed reports must contain information identified in paragraphs
(e)(1) through (7) of this section.
(1) MTEs. This section of the report must contain the following
information for MTEs conducted in the HSTT Study Area.
(i) Exercise information (for each MTE).
(A) Exercise designator.
(B) Date that exercise began and ended.
(C) Location.
(D) Number and types of active sonar sources used in the exercise.
(E) Number and types of passive acoustic sources used in exercise.

[[Page 68366]]

(F) Number and types of vessels, aircraft, and other platforms
participating in exercise.
(G) Total hours of all active sonar source operation.
(H) Total hours of each active sonar source bin.
(I) Wave height (high, low, and average) during exercise.
(ii) Individual marine mammal sighting information for each
sighting in each exercise where mitigation was implemented:
(A) Date, time, and location of sighting.
(B) Species (if not possible, indication of whale/dolphin/
pinniped).
(C) Number of individuals.
(D) Initial Detection Sensor (e.g., sonar, Lookout).
(E) Indication of specific type of platform observation was made
from (including, for example, what type of surface vessel or testing
platform).
(F) Length of time observers maintained visual contact with marine
mammal.
(G) Sea state.
(H) Visibility.
(I) Sound source in use at the time of sighting.
(J) Indication of whether animal was less than 200 yd (182.9 m),
200 to 500 yd (182.9 to 457.2 m), 500 to 1,000 yd (457.2 m to 914.4 m),
1,000 to 2,000 yd (914.4 m to 1,828.8 m), or greater than 2,000 yd
(1,828.8 m) from sonar source.
(K) Whether operation of sonar sensor was delayed, or sonar was
powered or shut down, and how long the delay.
(L) If source in use was hull-mounted, true bearing of animal from
the vessel, true direction of vessel's travel, and estimation of
animal's motion relative to vessel (opening, closing, parallel).
(M) Lookouts must report, in plain language and without trying to
categorize in any way, the observed behavior of the animal(s) (such as
animal closing to bow ride, paralleling course/speed, floating on
surface and not swimming, etc.) and if any calves were present.
(iii) An evaluation (based on data gathered during all of the MTEs)
of the effectiveness of mitigation measures designed to minimize the
received level to which marine mammals may be exposed. This evaluation
must identify the specific observations that support any conclusions
the Navy reaches about the effectiveness of the mitigation.
(2) SINKEXs. This section of the report must include the following
information for each SINKEX completed that year.
(i) Exercise information (gathered for each SINKEX).
(A) Location.
(B) Date and time exercise began and ended.
(C) Total hours of observation by Lookouts before, during, and
after exercise.
(D) Total number and types of explosive source bins detonated.
(E) Number and types of passive acoustic sources used in exercise.
(F) Total hours of passive acoustic search time.
(G) Number and types of vessels, aircraft, and other platforms
participating in exercise.
(H) Wave height in feet (high, low, and average) during exercise.
(I) Narrative description of sensors and platforms utilized for
marine mammal detection and timeline illustrating how marine mammal
detection was conducted.
(ii) Individual marine mammal observation (by Navy Lookouts)
information for each sighting where mitigation was implemented.
(A) Date/Time/Location of sighting.
(B) Species (if not possible, indicate whale, dolphin, or
pinniped).
(C) Number of individuals.
(D) Initial detection sensor (e.g., sonar or Lookout).
(E) Length of time observers maintained visual contact with marine
mammal.
(F) Sea state.
(G) Visibility.
(H) Whether sighting was before, during, or after detonations/
exercise, and how many minutes before or after.
(I) Distance of marine mammal from actual detonations (or target
spot if not yet detonated): Less than 200 yd (182.9 m), 200 to 500 yd
(182.9 to 457.2 m), 500 to 1,000 yd (457.2 m to 914.4 m), 1,000 to
2,000 yd (914.4 m to 1,828.8 m), or greater than 2,000 yd (1,828.8 m).
(J) Lookouts must report, in plain language and without trying to
categorize in any way, the observed behavior of the animal(s) (such as
animal closing to bow ride, paralleling course/speed, floating on
surface and not swimming etc.), including speed and direction and if
any calves were present.
(K) The report must indicate whether explosive detonations were
delayed, ceased, modified, or not modified due to marine mammal
presence and for how long.
(L) If observation occurred while explosives were detonating in the
water, indicate munition type in use at time of marine mammal
detection.
(3) Summary of sources used. This section of the report must
include the following information summarized from the authorized sound
sources used in all training and testing events:
(i) Total annual hours or quantity (per the LOA) of each bin of
sonar or other acoustic sources (e.g., pile driving and air gun
activities); and
(ii) Total annual expended/detonated ordinance (missiles, bombs,
sonobuoys, etc.) for each explosive bin.
(4) Humpback Whale Special Reporting Area (December 15-April 15).
The Navy must report the total hours of operation of surface ship hull-
mounted mid-frequency active sonar used in the special reporting area.
(5) HSTT Study Area Mitigation Areas. The Navy must report any use
that occurred as specifically described in these areas. Information
included in the classified annual reports may be used to inform future
adaptive management of activities within the HSTT Study Area.
(6) Geographic information presentation. The reports must present
an annual (and seasonal, where practical) depiction of training and
testing bin usage (as well as pile driving activities) geographically
across the HSTT Study Area.
(7) Sonar exercise notification. The Navy must submit to NMFS
(contact as specified in the LOA) an electronic report within 15
calendar days after the completion of any MTE indicating:
(i) Location of the exercise;
(ii) Beginning and end dates of the exercise; and
(iii) Type of exercise.
(g) Seven-year close-out comprehensive training and testing
activity report. This report must be included as part of the 2025
annual training and testing report. This report must provide the annual
totals for each sound source bin with a comparison to the annual
allowance and the 7-year total for each sound source bin with a
comparison to the 7-year allowance. Additionally, if there were any
changes to the sound source allowance, this report must include a
discussion of why the change was made and include the analysis to
support how the change did or did not result in a change in the 2018
HSTT FEIS/OEIS and final rule determinations. The draft report must be
submitted within 3 months after the expiration of this subpart to the
Director, Office of Protected Resources, NMFS. NMFS must submit
comments on the draft close-out report, if any, within 3 months of
receipt. The report will be considered final after the Navy has
addressed NMFS' comments, or 3 months after the submittal of the draft
if NMFS does not provide comments.

Sec. 218.76 Letters of Authorization.

(a) To incidentally take marine mammals pursuant to the regulations
in

[[Page 68367]]

this subpart, the Navy must apply for and obtain LOAs in accordance
with Sec. 216.106 of this chapter.
(b) LOAs, unless suspended or revoked, may be effective for a
period of time not to exceed December 20, 2025.
(c) If an LOA expires prior to December 20, 2025, the Navy may
apply for and obtain a renewal of the LOA.
(d) In the event of projected changes to the activity or to
mitigation, monitoring, or reporting (excluding changes made pursuant
to the adaptive management provision of Sec. 218.77(c)(1)) required by
an LOA issued under this subpart, the Navy must apply for and obtain a
modification of the LOA as described in Sec. 218.77.
(e) Each LOA must set forth:
(1) Permissible methods of incidental taking;
(2) Geographic areas for incidental taking;
(3) Means of effecting the least practicable adverse impact (i.e.,
mitigation) on the species or stocks of marine mammals and their
habitat; and
(4) Requirements for monitoring and reporting.
(f) Issuance of the LOA(s) must be based on a determination that
the level of taking is consistent with the findings made for the total
taking allowable under the regulations in this subpart.
(g) Notice of issuance or denial of the LOA(s) must be published in
the Federal Register within 30 days of a determination.

Sec. 218.77 Renewals and modifications of Letters of Authorization.

(a) An LOA issued under Sec. Sec. 216.106 of this chapter and
218.76 for the activity identified in Sec. 218.70(c) may be renewed or
modified upon request by the applicant, provided that:
(1) The planned specified activity and mitigation, monitoring, and
reporting measures, as well as the anticipated impacts, are the same as
those described and analyzed for the regulations in this subpart
(excluding changes made pursuant to the adaptive management provision
in paragraph (c)(1) of this section); and
(2) NMFS determines that the mitigation, monitoring, and reporting
measures required by the previous LOA(s) were implemented.
(b) For LOA modification or renewal requests by the applicant that
include changes to the activity or to the mitigation, monitoring, or
reporting measures (excluding changes made pursuant to the adaptive
management provision in paragraph (c)(1) of this section) that do not
change the findings made for the regulations or result in no more than
a minor change in the total estimated number of takes (or distribution
by species or stock or years), NMFS may publish a notice of planned LOA
in the Federal Register, including the associated analysis of the
change, and solicit public comment before issuing the LOA.
(c) An LOA issued under Sec. Sec. 216.106 of this chapter and
218.76 may be modified by NMFS under the following circumstances:
(1) Adaptive management. After consulting with the Navy regarding
the practicability of the modifications, NMFS may modify (including
adding or removing measures) the existing mitigation, monitoring, or
reporting measures if doing so creates a reasonable likelihood of more
effectively accomplishing the goals of the mitigation and monitoring.
(i) Possible sources of data that could contribute to the decision
to modify the mitigation, monitoring, or reporting measures in an LOA
include:
(A) Results from the Navy's monitoring from the previous year(s);
(B) Results from other marine mammal and/or sound research or
studies; or
(C) Any information that reveals marine mammals may have been taken
in a manner, extent, or number not authorized by the regulations in
this subpart or subsequent LOAs.
(ii) If, through adaptive management, the modifications to the
mitigation, monitoring, or reporting measures are substantial, NMFS
will publish a notice of planned LOA in the Federal Register and
solicit public comment.
(2) Emergencies. If NMFS determines that an emergency exists that
poses a significant risk to the well-being of the species or stocks of
marine mammals specified in LOAs issued pursuant to Sec. Sec. 216.106
of this chapter and 218.76, an LOA may be modified without prior notice
or opportunity for public comment. Notice would be published in the
Federal Register within 30 days of the action.

Sec. Sec. 218.78-218.79 [Reserved]

[FR Doc. 2023-21499 Filed 10-2-23; 8:45 am]
BILLING CODE 3510-22-P

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