Takes of Marine Mammals Incidental to Specified Activities: Taking Marine Mammals Incidental to U.S. Navy Surveillance Towed Array Sensor System Low Frequency Active Sonar Training and Testing in the Central and Western North Pacific Ocean and Eastern Indian Ocean, 40132-40213 [2019-16695]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 84, Number 156 (Tuesday, August 13, 2019)]
[Rules and Regulations]
[Pages 40132-40213]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-16695]



[[Page 40131]]

Vol. 84

Tuesday,

No. 156

August 13, 2019

Part II





Department of Commerce





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National Oceanic and Atmospheric Administration





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50 CFR Part 218





Takes of Marine Mammals Incidental to Specified Activities: Taking 
Marine Mammals Incidental to U.S. Navy Surveillance Towed Array Sensor 
System Low Frequency Active Sonar Training and Testing in the Central 
and Western North Pacific Ocean and Eastern Indian Ocean; Rules

Federal Register / Vol. 84 , No. 156 / Tuesday, August 13, 2019 / 
Rules and Regulations

[[Page 40132]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[190731-0008]
RIN 0648-BI42


Takes of Marine Mammals Incidental to Specified Activities: 
Taking Marine Mammals Incidental to U.S. Navy Surveillance Towed Array 
Sensor System Low Frequency Active Sonar Training and Testing in the 
Central and Western North Pacific Ocean and Eastern Indian Ocean

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

ACTION: Final rule; notification of issuance of Letter of 
Authorization.

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SUMMARY: NMFS, upon request from the U.S. Navy (Navy) issues these 
regulations pursuant to the Marine Mammal Protection Act (MMPA) to 
govern the taking of marine mammals incidental to the use of 
Surveillance Towed Array Sensor System Low Frequency Active (SURTASS 
LFA) sonar systems onboard U.S. Navy surveillance ships for training 
and testing activities conducted under the authority of the Secretary 
of the Navy in the western and central North Pacific Ocean and eastern 
Indian Ocean (SURTASS LFA sonar activities) beginning August 2019. 
These regulations, which allow for the issuance of a Letter of 
Authorization (LOA) for the incidental take of marine mammals during 
the described activities and timeframes, prescribe the permissible 
methods of taking and other means of effecting the least practicable 
adverse impact on marine mammal species or stocks and their habitat, 
and establish requirements pertaining to the monitoring and reporting 
of such taking.

DATES: Effective on August 12, 2019, through August 11, 2026.

ADDRESSES: A copy of the Navy's application and supporting documents, 
as well as a list of the references cited in this document, 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 call 
the contact listed below (see FOR FURTHER INFORMATION CONTACT).

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

SUPPLEMENTARY INFORMATION:

Purpose for Regulatory Action

    These regulations, issued under the authority of the MMPA (16 
U.S.C. 1361 et seq.), establish a framework for authorizing the take of 
marine mammals incidental to the Navy's use of SURTASS LFA sonar 
systems onboard U.S. Navy surveillance ships for training and testing 
activities (categorized as military readiness activities) conducted 
under the authority of the Secretary of the Navy in the western and 
central North Pacific Ocean and eastern Indian Ocean.
    NMFS received an application from the Navy requesting regulations 
and an associated letter of authorization (LOA) to take individuals of 
multiple species and stocks of marine mammals (``Navy's rulemaking/LOA 
application'' or ``Navy's application'') by Level B harassment 
incidental to SURTASS LFA sonar activities. Please see ``Background'' 
below for definitions of harassment. This final rule establishes a 
framework under the authority of the MMPA (16 U.S.C. 1361 et seq.) to 
allow for the authorization of take of marine mammals incidental to the 
Navy's specified activities.

Legal Authority for the Final Action

    Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) 
generally directs the Secretary of Commerce 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 for up to 
five years if, after notice and public comment, the agency makes 
certain findings and issues regulations that set forth permissible 
methods of taking and other means of effecting the least practicable 
adverse impact (LPAI) on the affected species or stocks and their 
habitat, as well as monitoring and reporting requirements. Section 
101(a)(5)(A) of the MMPA and the implementing regulations at 50 CFR 
part 216, subpart I provide the legal basis for issuing this final rule 
and any associated LOAs. As described in the Background section, the 
MMPA has been amended in a number of ways when the specified activity 
is a military readiness activity, including most recently in 2018 to 
extend the maximum authorization period under section 101(a)(5)(A) from 
five to seven years for Department of Defense military readiness 
activities. As directed by this legal authority, this final rule 
contains mitigation, monitoring, and reporting requirements.

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, an incidental 
harassment authorization may be issued following notice and opportunity 
for public comment.
    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 similar 
significance, and on the availability of such species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''), and requirements pertaining to the monitoring and 
reporting of such takings.
    The 2004 NDAA (Pub. L. 108-136) removed the ``small numbers'' and 
``specified geographical region'' limitations indicated above and 
amended the definition of ``harassment'' as it applies to a ``military 
readiness activity'' to read as follows (Section 3(18)(B) of the MMPA): 
(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 FY 2004 NDAA amended the MMPA as it 
relates to military readiness activities and the incidental take 
authorization (ITA) process such that ``least practicable adverse 
impact'' shall include consideration of personnel safety, practicality 
of implementation,

[[Page 40133]]

and impact on the effectiveness of the military readiness activity. As 
mentioned above, the NDAA for FY 2019 amended the MMPA to extend the 
period of permitted incidental takings of marine mammals covered by 
section 101(a)(5)(A) in the course of specified military readiness 
activities from five to seven years.
    The authorization of incidental taking under section 101(a)(5)(A) 
requires promulgation of activity-specific regulations following notice 
and opportunity for public comment. Under NMFS' implementing 
regulations for section 101(a)(5)(A), a Letter of Authorization (LOA) 
also is required to conduct activities pursuant to any activity-
specific regulations (50 CFR 216.106).

Summary of Request

    On June 4, 2018, NMFS received a request from the Navy for 
authorization to take, by Level B harassment, 46 species of marine 
mammals incidental to the use of SURTASS LFA sonar onboard U.S. Navy 
surveillance ships for training and testing activities (categorized as 
military readiness activities) conducted under the authority of the 
Secretary of the Navy in the western and central North Pacific Ocean 
and eastern Indian Ocean beginning in August 2019 and extending to 
August 2026. On July 13, 2018, NMFS published a notice of receipt (NOR) 
of the Navy's application in the Federal Register (83 FR 32615), and 
requested comments and information related to the Navy's request. The 
review and comment period for the NOR ended on August 13, 2018. The 
Navy submitted a revised application on November 13, 2018, that 
included a minor change to the mitigation measures provided in the June 
2018 application. On March 1, 2019, NMFS published a notice of proposed 
rulemaking in the Federal Register (84 FR 7186), and requested comments 
and information related to the Navy's request. The review and comment 
period for the proposed rule ended on April 1, 2019. One comment 
received during the NOR comment period was addressed in the Proposed 
Rule, and comments received during the proposed rulemaking comment 
period are addressed in this final rule. See further details addressing 
comments received in the Comments and Responses section.
    The Navy states, and NMFS concurs, that these SURTASS LFA sonar 
activities, classified as military readiness activities, may 
incidentally take marine mammals by exposing them to SURTASS LFA sonar 
at levels that constitute Level B harassment as defined above. The Navy 
requests authorization to take, by Level B Harassment, individuals from 
139 stocks of 46 species of marine mammals (10 species of mysticete 
(baleen) whales, 31 species of odontocete (toothed) whales, and 5 
species of pinnipeds (seals and sea lions)). This rule also covers the 
authorization of take of animals from additional associated stocks of 
marine mammals not listed here, should one or more of the stocks 
identified in this rule be formally separated into multiple stocks, 
provided NMFS is able to confirm the necessary findings for the newly 
identified stocks. As discussed later in this document, incidental 
takes due to SURTASS LFA sonar will be limited to Level B harassment. 
No takes by Level A harassment are authorized, as Level A harassment is 
considered unlikely and will be avoided through the implementation of 
the Navy's mitigation measures, as discussed below.
    In previous SURTASS LFA sonar rulemakings, NMFS authorized some 
Level A harassment takes in an abundance of caution even though Level A 
harassment takes were not anticipated. However, to the knowledge of the 
Navy and NMFS, no Level A harassment takes have resulted over the 17-
year history of SURTASS LFA sonar activities. Additionally, the 
exposure criteria and thresholds for assessing Level A harassment have 
been modified since prior rules based on the best available science. 
Under these new metrics, the zone for potential injury is substantially 
reduced. Therefore, due to the small injury zones and the fact that 
mitigation measures would ensure that marine mammals would not be 
exposed to received levels associated with injury, the Navy has not 
requested authorization for Level A harassment takes, and NMFS is not 
authorizing any takes by Level A harassment.
    NMFS published the first incidental take rule for SURTASS LFA 
sonar, effective from August 2002 through August 2007, on July 16, 2002 
(67 FR 46712); the second rule, effective from August 2007 through 
August 2012, on August 21, 2007 (72 FR 46846); and the third rule, 
effective from August 2012 through August 2017, on August 20, 2012 (77 
FR 50290).
    In 2016, the Navy submitted an application for a fourth incidental 
take regulation under the MMPA (DoN, 2016) for the taking of marine 
mammals by harassment incidental to the deployment of up to four 
SURTASS LFA sonar systems from August 15, 2017, through August 14, 
2022. NMFS published a proposed rule on April 27, 2017 (82 FR 19460). 
On August 10, 2017, the Deputy Secretary of Defense, after conferring 
with the Secretary of Commerce, determined that it was necessary for 
the national defense to exempt all military readiness activities that 
use SURTASS LFA sonar from compliance with the requirements of the MMPA 
for a period of up to two years beginning August 13, 2017, through 
August 12, 2019, or until such time when NMFS issues regulations and an 
LOA under MMPA section 101(a)(5)(A) for military readiness activities 
associated with the use of SURTASS LFA sonar, whichever is earlier. 
During the period of the National Defense Exemption (NDE) (available at 
https://www.surtass-lfa-eis.com/wp-content/uploads/2018/01/SURTASS_LFA_NDE_10Aug17.pdf), all military readiness activities that 
involve the use of SURTASS LFA sonar were required to comply with all 
mitigation, monitoring, and reporting measures set forth in the NDE for 
SURTASS LFA sonar, which were based on the measures included in NMFS' 
prior (2012) final rule (77 FR 50290; August 20, 2012) and 2017 
proposed rule (82 FR 19460; April 27, 2017). As a result of the NDE, 
NMFS did not finalize its April 2017 proposed rule.
    The NDE expires August 12, 2019. For this rulemaking, the Navy will 
continue to use SURTASS LFA sonar systems onboard United States Naval 
Ship (USNS) surveillance ships for training and testing activities 
conducted under the authority of the Secretary of the Navy within the 
western and central North Pacific Ocean and eastern Indian Ocean. The 
operating features of the LFA sonar will remain, and have remained the 
same since the 2001 SURTASS LFA FOEIS/EIS. The typical duty cycle of 
LFA sonar, based on historical SURTASS LFA sonar use, is 7.5 to 10 
percent (DoN, 2007). The maximum duty cycle remains the same at 20 
percent.
    For this rulemaking, the Navy scoped the geographic extent of the 
area where the specified activity will occur (Study Area) to better 
reflect the areas where the Navy anticipates conducting SURTASS LFA 
sonar training and testing activities. Whereas the previous 
authorizations included certain routine military operations among the 
scope of actions analyzed, the Navy also has narrowed the scope of 
activities in the current request for authorization to training and 
testing activities only, due to various statutory and practical 
considerations, as described in Chapter 1 of the 2019 SURTASS LFA 
FSEIS/SOEIS, and discussed further below.
    The Navy will transmit a total of up to 496 LFA sonar transmission 
hours

[[Page 40134]]

per year for its specified activity, as described below (see 
Description of the Specified Activities section), pooled across all 
SURTASS LFA sonar-equipped vessels in the first four years of the 
authorization, with an increase in usage to a total of up to 592 LFA 
transmission hours in years five through seven.

Changes From the Proposed to the Final Rule

    Since the proposed rule, based on public comment and additional 
analysis, NMFS and the Navy have agreed to additional mitigation and 
monitoring measures that are expected to reduce the likelihood and/or 
severity of adverse impacts on marine mammal species/stocks and their 
habitat and are practicable for implementation.
     In the proposed rule we presented 25 marine areas for 
further consideration as marine mammal Offshore Biologically Important 
Areas (OBIAs) for SURTASS LFA sonar. After considering public comments 
and conducting additional analyses, 33 marine areas were assessed as 
potential OBIAs. Of these 33 marine areas, 17 were determined to 
qualify as OBIAs. All 17 of the areas were found to be practicable and 
were designated as 14 OBIAs (some OBIAs encompass several marine 
areas). All four of the OBIAs previously designated in the SURTASS LFA 
sonar Study Area have been expanded spatially.
     The Navy will use no more than 25 percent of the 
authorized amount (transmission hours) of SURTASS LFA sonar for 
training and testing within 10 nautical miles (nmi) (18.5 kilometers 
(km)) of any single OBIA during any year (no more than 124 hours in 
years 1-4 and 148 hours in years 5-7) unless the following conditions 
are met: Should national security present a requirement to conduct more 
than 25 percent of authorized hours of SURTASS LFA sonar within 10 nmi 
(18.5 km) of any single OBIA during any year, naval units will obtain 
permission from the appropriate designated Command authority prior to 
commencement of the activity. The Navy will provide NMFS with 
notification as soon as is practicable and include the information 
(e.g., sonar hours) in its annual activity reports submitted to NMFS.
     The Navy has agreed to evaluate the feasibility and 
appropriate methods to collect new data to supplement the data 
available on behavioral responses of marine mammals to SURTASS LFA 
sonar using newer methods and technologies. These types of scientific 
inquiries fit within the scope the Navy's Living Marine Resources (LMR) 
program. The LMR program weighs the various Navy research needs against 
each other through a needs and solicitation process. The Navy has 
submitted a needs statement to the LMR advisory committee to research 
future data collection that would supplement understanding of how 
SURTASS LFA sonar may affect marine resources, including mysticetes and 
beaked whales.

Description of the Specified Activities

Overview

    The Navy's primary mission is to organize, train, and equip combat-
ready naval forces capable of accomplishing American strategic 
objectives, deterring maritime aggression, and assuring freedom of 
navigation in ocean areas. This mission is mandated by Federal law in 
Section 8062 of Title 10 of the United States Code, which directs the 
Secretary of the Navy to ensure the readiness of the U.S. naval forces.
    The Secretary of the Navy and the Chief of Navy Operations (CNO) 
have established that anti-submarine warfare (ASW) is a critical 
capability for achieving the Navy's mission, and it requires unfettered 
access to both the high seas and littoral environments to be prepared 
for all potential threats by maintaining ASW core competency. The Navy 
is challenged by the increased difficulty in locating undersea threats 
solely by using passive acoustic technologies due to the advancement 
and use of quieting technologies in diesel-electric and nuclear 
submarines. At the same time, as the distance at which submarine 
threats can be detected decreases due to quieting technologies, 
improvements in torpedo and missile design have extended the effective 
range of these weapons.
    One of the ways the Navy has addressed the changing requirements 
for ASW readiness was to develop SURTASS LFA sonar, which is able to 
reliably detect quieter and harder-to-find submarines at long range 
before these vessels can get within their effective weapons range to 
launch against their targets. SURTASS LFA sonar systems have a passive 
component (SURTASS), which is a towed line array of hydrophones used to 
detect sound emitted or reflected from submerged targets, and an active 
component (LFA), which is comprised of a set of acoustic transmitting 
elements. The active component detects objects by creating a sound 
pulse, or ``ping'' that is transmitted through the water and reflects 
off the target, returning in the form of an echo similar to 
echolocation used by some marine mammals to locate prey and navigate. 
SURTASS LFA sonar systems are long-range sensors that operate in the 
low-frequency (LF) band (i.e., 100-500 Hertz (Hz)). Because LF sound 
travels in seawater for greater distances than higher frequency sound, 
the SURTASS LFA sonar system meets the need for improved detection and 
tracking of new-generation submarines at a longer range and maximizes 
the opportunity for U.S. armed forces to safely react to, and defend 
against, potential submarine threats while remaining a safe distance 
beyond a submarine's effective weapons range. Thus, the active acoustic 
component in the SURTASS LFA sonar is an important augmentation to the 
Navy's passive and tactical systems, as its long-range detection 
capabilities can effectively counter the threat to the Navy and 
national security interests posed by quiet, diesel submarines.
    The Navy's specified activities for MMPA incidental take coverage 
is to continue employment of SURTASS LFA sonar systems onboard USNS 
surveillance ships for training and testing activities conducted under 
the authority of the Secretary of the Navy in the western and central 
Pacific Ocean and eastern Indian Ocean, which is classified as a 
military readiness activity, beginning August 13, 2019. The use of the 
SURTASS LFA sonar system will result in acoustic stimuli from the 
generation of sound or pressure waves in the water at or above levels 
that NMFS has determined would result in take of marine mammals under 
the MMPA. This is the principal means of marine mammal taking 
associated with these military readiness activities. In addition to the 
use of active acoustic sources, the Navy's activities include the 
movement of vessels. This final rule also analyzes the potential 
effects of this aspect of the activities. NMFS does not anticipate 
takes of marine mammals to result from ship strikes from any SURTASS 
LFA vessels because each vessel moves at a relatively slow speed (10 to 
12 knots (kt) while transiting), especially when towing the SURTASS and 
LFA sonar systems (moving at 3 to 4 kt), and for a relatively short 
period of time. Combined with the use of mitigation measures as noted 
below, it is likely that surveillance vessels will be able to avoid any 
marine mammals.
    The Navy will restrict SURTASS LFA sonar training and testing 
activities to the central and western North Pacific Ocean and eastern 
Indian Ocean. The Navy will not conduct training or testing utilizing 
SURTASS LFA sonar within the foreign territorial seas of other nations 
and will maintain

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SURTASS LFA sonar received levels below 180 decibels (dB) re: 1 [mu]Pa 
(root-mean-square (rms)) within 12 nmi (22 km) of any emerged land 
features or within 1 km of the seaward boundaries of designated 
Offshore Biologically Important Areas (OBIAs) during their effective 
periods (see Mitigation section below for OBIA details). In addition to 
these geographic mitigation measures, the Navy will implement 
procedural mitigation measures, including monitoring for the presence 
of marine mammals (including visual as well as active and passive 
acoustic monitoring) and implementing shutdown procedures for marine 
mammals within a mitigation zone around the LFA sonar source (see 
Mitigation and Monitoring sections below for further details).

Dates and Duration

    The specified activities may occur at any time during the seven-
year period of validity of the regulations (August 13, 2019, through 
August 12, 2026). The Navy currently conducts SURTASS LFA sonar 
activities from four vessels. The Navy is planning to add new vessels 
to its ocean surveillance fleet. As new vessels are developed, the 
onboard LFA and High Frequency Marine Mammal Monitoring sonar (HF/M3 
sonar) systems (discussed below) may need to be updated, modified, or 
even re-designed. Current indications are that future LFA sonar systems 
will have the same operational characteristics and that updates and 
modifications are focused toward miniaturizing the system components to 
reduce the weight and handling of the systems. If system parameters are 
modified as a result of these updates the Navy will determine if 
supplementary analysis would be required to cover the deployment of 
these new systems. As the new vessels and sonar system components are 
developed and constructed, at-sea testing would eventually be 
necessary. The Navy anticipates that new vessels, or new/updated sonar 
system components, would be ready for at-sea testing beginning in the 
fifth year of the time period covered by this final rule.
    Thus, the Navy's activity analysis included consideration of the 
sonar hours associated with future testing of new or updated LFA sonar 
system components and new ocean surveillance vessels. This 
consideration resulted in two scenarios of annual sonar transmit hours: 
Years 1 to 4 will entail up to 496 hours total per year across all 
SURTASS LFA sonar vessels, while years 5 to 7 will include an increase 
in LFA sonar transmit hours up to 592 hours across all vessels.
    The SURTASS LFA sonar transmission hours represent a distribution 
across six activities that include (with an approximate allocation of 
hours indicated):
     Contractor crew proficiency training (80 hours per year);
     Military crew (MILCREW) proficiency training (96 hours per 
year);
     Participation in or support of naval exercises (96 hours 
per year);
     Vessel and equipment maintenance (64 hours per year);
     Acoustic research testing (160 hours per year); and
     New SURTASS LFA sonar system testing (96 hours per year; 
will occur in years 5 to 7).
    Each of these activities utilizes the SURTASS LFA sonar system 
within the operating profile described above; therefore, the number of 
hours designated for each activity represents an estimate for planning 
purposes.
    As noted above, this rulemaking would result in the fourth such 
regulation for the Navy's SURTASS LFA sonar activities. The Navy is 
currently conducting the specified activities under an NDE that will 
expire on August 12, 2019. Therefore, the Navy requested MMPA 
rulemaking and an LOA for SURTASS LFA sonar training and testing 
activities effective beginning August 13, 2019, to take marine mammals 
incidental to the SURTASS LFA sonar activities for a seven year period.

SURTASS LFA Sonar Training and Testing Areas

    The geographic area of the SURTASS LFA sonar activities covered by 
these regulations includes the western and central North Pacific Ocean 
and eastern Indian Ocean outside of the territorial seas of foreign 
nations (generally 12 nmi (22 km) from most foreign nations). Figure 1 
depicts the areas of SURTASS LFA sonar activities. In areas within 12 
nmi from any emergent land (coastal exclusion areas) and in areas 
identified as OBIAs, SURTASS LFA sonar training and testing would be 
conducted such that received levels of LFA sonar are below 180 dB re: 1 
[mu]Pa rms sound pressure level (SPL). This restriction will be 
observed year-round for coastal standoff zones and during known periods 
of biological importance for OBIAs.
BILLING CODE 3510-22-P

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[GRAPHIC] [TIFF OMITTED] TR13AU19.000

BILLING CODE 3510-22-C
    For this rulemaking, the Navy scoped the geographic extent of its 
specified activities to better reflect the areas where the Navy 
anticipates conducting SURTASS LFA sonar training and testing 
activities now through 2026. Fifteen representative model areas (shown 
in Figure 1 and listed in Table 1), with nominal modeling sites in each 
region, provide geographic context for the SURTASS LFA sonar 
activities.

 Table 1--Representative SURTASS LFA Sonar Modeling Areas That the Navy
    Modeled for the 2019 SURTASS LFA FSEIS/SOEIS and the Navy's MMPA
                       Rulemaking/LOA Application
------------------------------------------------------------------------
                                     Location
                                    (latitude/
         Modeled site              longitude of            Notes
                                    center of
                                  modeling area)
------------------------------------------------------------------------
East of Japan.................  38[deg] N,
                                 148[deg] E.
North Philippine Sea..........  29[deg] N,
                                 136[deg] E.
West Philippine Sea...........  22[deg] N,
                                 124[deg] E.
Offshore Guam.................  11[deg] N,         Navy Mariana Islands
                                 145[deg] E.        Testing and Training
                                                    Area.
Sea of Japan..................  39[deg] N,
                                 132[deg] E.
East China Sea................  26[deg] N,
                                 125[deg] E.
South China Sea...............  14[deg] N,
                                 114[deg] E.
Offshore Japan 25[deg] to       30[deg] N,
 40[deg] N.                      165[deg] E.
Offshore Japan 10[deg] to       15[deg] N,
 25[deg] N.                      165[deg] E.
Hawaii North..................  25[deg] N,         Navy Hawaii-Southern
                                 158[deg] W.        California Training
                                                    and Testing Area.
Hawaii South..................  19.5[deg] N,       Navy Hawaii-Southern
                                 158.5[deg] W.      California Training
                                                    and Testing Area.
Offshore Sri Lanka............  5[deg] N, 85[deg]
                                 E.
Andaman Sea...................  7.5[deg] N,
                                 96[deg] E.
Northwest of Australia........  18[deg] S,
                                 110[deg] E.
Northeast of Japan............  52[deg] N,
                                 163[deg] E.
------------------------------------------------------------------------


[[Page 40137]]

Detailed Description of the Specified Activities

    SURTASS LFA Sonar--SONAR is an acronym for Sound Navigation and 
Ranging, and its definition includes any system (biological or 
mechanical) that uses underwater sound, or acoustics, for detection, 
monitoring, and/or communications. Active sonar is the transmission of 
sound energy for the purpose of sensing the environment by interpreting 
features of received signals. Active sonar detects objects by creating 
a sound pulse, or ``ping'' that is transmitted through the water and 
reflects off the target, returning in the form of an echo. Passive 
sonar detects the transmission of sound waves created by an object.
    As mentioned previously, the SURTASS LFA sonar system is a long-
range, all-weather LF sonar (operating between 100 and 500 Hertz (Hz)) 
system that has both active and passive components. LFA, the active 
system component (which allows for the detection of an object that is 
not generating noise), is comprised of source elements (called 
projectors) suspended vertically on a cable beneath the surveillance 
vessel. The projectors produce an active sound pulse by converting 
electrical energy to mechanical energy by setting up vibrations or 
pressure disturbances within the water to produce a ping. The Navy uses 
LFA as an augmentation to the passive SURTASS operations when passive 
system performance is inadequate. SURTASS, the passive part of the 
system, uses hydrophones (i.e., underwater microphones) to detect sound 
emitted or reflected from submerged targets, such as submarines. The 
SURTASS hydrophones are mounted on a horizontal line array that is 
towed behind the surveillance vessel. The Navy processes and evaluates 
the returning signals or echoes, which are usually below background or 
ambient sound level, to identify and classify potential underwater 
targets.
    LFA Active Component--The active component of the SURTASS LFA sonar 
system consists of up to 18 projectors suspended beneath the 
surveillance vessel in a vertical line array. The SURTASS LFA sonar 
projectors transmit in the low-frequency band (between 100 and 500 Hz). 
The source level of an individual projector in the SURTASS LFA sonar 
array is approximately 215 dB re: 1 [mu]Pa at 1 m or less. Sound 
pressure is the sound force per unit area and is usually measured in 
micropascals ([mu]Pa), where one Pascal (Pa) is the pressure resulting 
from a force of one newton exerted over an area of one square meter 
(m\2\). The commonly used reference pressure level in underwater 
acoustics is 1 [mu]Pa at 1 m, and the units for source level are 
decibels (dB) re: 1 [mu]Pa at 1 m). Because of the physics involved in 
acoustic beamforming (i.e., a method of mapping noise sources by 
differentiating sound levels based upon the direction from which they 
originate) and sound transmission loss processes, the SURTASS LFA sonar 
array cannot have a sound pressure level (SPL) higher than the SPL of 
an individual projector.
    The SURTASS LFA sonar acoustic transmission is an omnidirectional 
beam (a full 360 degrees ([deg])) in the horizontal plane. The LFA 
sonar system also has a narrow vertical beam that the vessel's crew can 
steer above or below the horizontal plane. The typical SURTASS LFA 
sonar signal is not a constant tone, but rather is a transmission of 
various signal types that vary in frequency and duration (including 
continuous wave (CW) and frequency-modulated (FM) signals). A complete 
sequence of sound transmissions, also referred to by the Navy as a 
``ping'' or a wavetrain, can be as short as six seconds (sec) or last 
as long as 100 sec, with an average length of 60 sec. Within each ping, 
the duration of any continuous frequency sound transmission is no 
longer than 10 seconds and the time between pings is typically from six 
to 15 minutes (min). Based on the Navy's historical operating 
parameters, the average duty cycle (i.e., the ratio of sound ``on'' 
time to total time) for LFA sonar is normally 7.5 to 10 percent and 
will not exceed a maximum duty cycle of 20 percent.
    Compact LFA Active Component--In addition to the LFA sonar system 
currently deployed on the USNS IMPECCABLE, the Navy developed a compact 
LFA (CLFA) sonar system, which is now deployed on its three smaller 
surveillance vessels (i.e., the USNS ABLE, EFFECTIVE, and VICTORIOUS). 
The operational characteristics of the active component for the CLFA 
sonar system are comparable to the LFA sonar system and the potential 
impacts from the CLFA sonar system will be similar to the effects from 
the LFA sonar system. The CLFA sonar system consists of smaller 
projectors that weigh 142,000 lbs (64,410 kilograms (kg)), which is 
182,000 lbs (82,554 kg) less than the weight of the LFA projectors on 
the USNS IMPECCABLE. The CLFA sonar system also consists of up to 18 
projectors suspended beneath the surveillance vessel in a vertical line 
array, and the CLFA sonar system projectors transmit in the low-
frequency band (also between 100 and 500 Hz) with the same duty cycle 
as described for LFA sonar. Similar to the active component of the LFA 
sonar system, the source level of an individual projector in the CLFA 
sonar array is approximately 215 dB re: 1 [mu]Pa or less.
    For the analysis in this rulemaking, NMFS will use the term LFA to 
refer to both the LFA sonar system and/or the CLFA sonar system, unless 
otherwise specified.
    SURTASS Passive Component--The passive component of the SURTASS LFA 
sonar system consists of a SURTASS Twin-line (TL-29A) horizontal line 
array mounted with hydrophones. The Y-shaped array is 1,000 ft (305 m) 
in length and has an operational depth of 500 to 1,500 ft (152.4 to 
457.2 m).
    High-Frequency Marine Mammal Monitoring Active Sonar (HF/M3)--
Although technically not part of the SURTASS LFA sonar system, the Navy 
will also use a high-frequency sonar system, called the HF/M3 sonar, to 
detect and locate marine mammals within the SURTASS LFA sonar 
mitigation zone, as described in the Mitigation and Monitoring 
sections. This enhanced commercial fish-finding sonar, mounted at the 
top of the SURTASS LFA sonar vertical line array, has a source level of 
220 dB re: 1 [mu]Pa at 1 m with a frequency range of 30 to 40 kilohertz 
(kHz). The duty cycle is variable, but is normally below three to four 
percent and the maximum pulse duration is 40 milliseconds (ms). The HF/
M3 sonar has four transducers with 8 degrees horizontal and 10 degrees 
vertical beamwidths, which sweep a full 360 degrees in the horizontal 
plane every 45 to 60 sec with a maximum range of approximately 1.2 mi 
(2 km).
    Vessel Specifications--The Navy currently deploys SURTASS LFA sonar 
on four twin-hulled ocean surveillance vessels that are 235 to 282 feet 
(ft) (72 to 86 m) in length, with twin-shafted diesel electric engines 
capable of providing 3,200 to 5,000 horsepower. Each vessel has an 
observation area on the bridge that is more than 30 ft above sea level 
from where lookouts will monitor for marine mammals whenever SURTASS 
LFA sonar is transmitting. As stated previously, the Navy may develop 
and field additional SURTASS LFA equipped vessels, either to replace or 
complement the Navy's current SURTASS LFA capable fleet, and these 
vessels may be in use beginning in the fifth year of the time period 
covered by this rulemaking.
    The operational speed of each vessel during sonar activities will 
be approximately 3.4 miles per hour (mph)

[[Page 40138]]

(5.6 km per hour (km/hr); 3 kt) and each vessel's cruising speed 
outside of sonar activities would be a maximum of approximately 11.5 to 
14.9 mph (18.5 to 24.1 km/hr; 10 to 13 kt). During sonar activities, 
the SURTASS LFA sonar vessels will generally travel in straight lines 
or in oval-shaped (i.e., racetrack) patterns depending on the training 
or testing scenario.

Comments and Responses

    We published a notice of proposed rule in the Federal Register on 
March 1, 2019 (84 FR 7186), with a 30-day comment period. During the 
30-day comment period, we received eight total comment letters. Of this 
total, one submission was from another Federal agency, one letter was 
from organizations or individuals acting in an official capacity (e.g., 
non-governmental organizations (NGOs)), and six submissions were from 
private citizens. NMFS has reviewed all public comments received on the 
proposed rule and issuance of the LOA. All relevant comments and our 
responses are described below organized by major category. We provide 
no response to specific comments that addressed species or statutes not 
relevant to our proposed rule under section 101(a)(5)(A) of the MMPA 
(e.g., comments related to sea turtles).

General Comments

    The majority of the comments from six private citizens expressed 
general opposition toward the Navy's proposed training and testing 
activities, cited concern for marine mammals and the oceans, and 
requested that NMFS not issue the LOAs, but without providing 
information relevant to NMFS' decisions. NMFS appreciates the concerns 
expressed for marine life and resources. We reiterate that no mortality 
of marine mammals is anticipated, nor is any injury (Level A 
harassment) of marine mammals anticipated; therefore, neither injuries 
nor mortality of marine mammals is authorized for the SURTASS LFA sonar 
activities. Moreover, the MMPA directs the Secretary of Commerce (whose 
authority has been delegated to NMFS) to allow, upon request, the 
incidental taking for a specified activity, provided that we are able 
to make the required findings under section 101(a)(5)(A) and set forth 
regulations containing the required prescriptions for mitigation, 
monitoring, and reporting after notice and comment. Therefore, these 
comments were not considered further. The remaining comments are 
addressed below.

Impact Analysis

Density Estimates
    Comment 1: The Marine Mammal Commission (hereafter ``Commission'') 
expressed concerns regarding the density estimates used in Navy's 
Global Marine Species Density Database (Global NMSDD). The Commission 
and The Commission and Natural Resources Defense Council (NRDC), The 
Humane Society of the United States, and Humane Society Legislative 
Fund (hereafter ``NRDC et al.'') recommended that NMFS require the Navy 
to make available to the public the resulting products of the current 
version of the Global NMSDD, similar to the information provided in 
Department of the Navy (2017c), as soon as possible. The Commission 
noted that they have requested for several years that this information 
be made available to the public and are puzzled why neither the Navy 
nor NMFS has provided it. The Commission asserted that without public 
access to such data, the process is not transparent and there is no 
basis to assert that either NMFS' or the Navy's analyses are based on 
best available data.
    Response: Currently, the NMSDD is not publically available since 
proprietary geospatial modeling data are included in the database, for 
which the Navy has established proprietary data sharing agreements. 
However, products of the Navy's database have been made available to 
the public, such as the U.S. Navy Marine Species Density Database Phase 
III for the Hawaii-Southern California Training and Testing Study Area 
(DoN, 2017c). The citations for the sighting surveys or other data upon 
which the densities were derived in the NMSDD have been provided when 
appropriate, and information similar to that presented in the U.S. Navy 
Marine Species Density Database Phase III for the Hawaii-Southern 
California Training and Testing Study Area (DoN, 2017c) is provided in 
the 2019 SURTASS LFA FSEIS/SOEIS (Chapter 3 and Appendix D) for the 15 
Representative Modeling Areas in the SURTASS LFA sonar Study Area. 
Chapter 3, Section 3.4.3.3.3 describes the process and methods used to 
derive marine mammal occurrence and population estimates (abundance and 
density) in the model areas. Appendix D includes detailed information 
on the available data and abundance and density estimates by model area 
and species/stock and these references are also included in the marine 
mammal species, stocks (DPSs), abundance, and density estimates by 
season summary table (Chapter 3, Table 3-8). When the NMSDD is 
referenced in the Offshore Sri Lanka, Andaman Sea, Northwestern 
Australia, and Northeast of Japan (humpback whales only) modeling areas 
the specific data source (e.g., Kaschner et al., 2006 or SMRU Ltd., 
2012) is also referenced. NMFS coordinated closely with the Navy in the 
development of its incidental take application, and agrees that the 
methods the Navy has put forth described herein to estimate densities 
are appropriate and based on the best available science.
    Comment 2: The Commission and NRDC et al. recommended that NMFS 
specify whether and how uncertainty was incorporated in abundance and 
density estimates in the preamble to the final rule and, if it was not, 
that NMFS require the Navy to incorporate measures of uncertainty 
inherent in the underlying data (e.g., CV, standard deviations, 
standard errors) in those estimates and re-estimate the numbers of 
takes accordingly in the final rule. The Commission noted that for all 
of the Navy's Phase III activities since 2016, including for Hawaii-
Southern California Training and Testing (HSTT), the Navy has 
incorporated uncertainty in the densities and the group size estimates 
that ultimately seed its animat modeling. It is unclear why the same 
approach was not taken for SURTASS LFA sonar, particularly since the 
action areas for HSTT and SURTASS LFA sonar overlap.
    Response: Information on uncertainty (e.g., CV, standard 
deviations, standard errors, etc.) in species/stock population 
estimates for each modeling area is included when available in the 2019 
SURTASS LFA FSEIS/SOEIS (Chapter 3 and Appendix D). The population 
estimates provided in the 2019 SURTASS LFA FSEIS/SOEIS (Chapter 3 and 
Appendix D) were used to model estimated takes using the Acoustic 
Integration Model (AIM) (described in the Estimated Take of Marine 
Mammals section). The AIM is a Monte Carlo based statistical model in 
which multiple iterations of realistic predictions of acoustic source 
use as well as animal distribution and movement patterns (``animats'') 
are conducted to provide statistical predictions of estimated impacts 
from exposure to acoustic source transmissions. AIM does not include 
uncertainty in population estimates to predict estimated takes, however 
uncertainty in the horizontal and vertical movement patterns of marine 
mammals is incorporated through the Monte Carlo components of the AIM. 
At each 30-sec timestep, the diving pattern, swim speed, and heading of 
each animat are re-sampled, resulting in movement of each animat 
through the acoustic

[[Page 40139]]

field. In the AIM, the modeled marine mammal animats were set to 
populate the simulation area with densities of 0.086, 0.17, or 0.34 
animats/nmi\2\ (0.025, 0.05, or 0.1 animats/km\2\). These densities are 
often higher than those estimated in the marine environment (as many 
species/stocks are rare in modelled areas). This ``over population'' of 
the modeling environment ensures that the result of the simulation is 
not unduly influenced by the chance placement of a few simulated marine 
mammals. To obtain final harassment estimates, the modeled results are 
normalized by the ratio of the modeled animat density to the real-world 
marine mammal density estimate. This allows for greater statistical 
power without overestimating risk. Additional details on the methods 
used to calculate take estimates are included in the Estimated Take of 
Marine Mammals section. NMFS considers these estimates conservative as 
take estimates are based on the maximum potential impact to a species 
or stock across all model areas in which a SURTASS LFA sonar activity 
may occur. Therefore, if an activity occurs in a different model area 
than the area where the maximum potential impact was predicted, the 
actual potential impact may be less than estimated. Here, the densities 
and modeling used reflect the best available science and, further, 
monitoring of SURTASS activities from the past 17 years of activities 
do not suggest that these models have underestimated marine mammal 
exposure.
    Comment 3: NRDC et al. recommended that NMFS consider alternative 
and potentially more powerful modeling approaches that are emerging to 
extrapolate cetacean densities beyond surveyed regions (Corkeron et 
al., 2011; Lambert et al., 2014; Mannocci et al., 2015) which are 
likely to be superior to the Kaschner et al. (2006) model (and more 
consistent with the prior recommendations of NMFS biologists) that the 
Navy has relied on in the past. They recommended that the Navy should 
consult with NMFS experts on the utility of these models for estimating 
densities within the LFA Study Area. They also recommended that NMFS 
examine the data collected during the International Whaling 
Commission's Pacific Ocean Whale and Ecosystem Research Programme (IWC-
POWER) 2010, 2013, 2014, 2015, and 2016 surveys with the view to 
developing improved marine mammal density models for regions of the 
western and central Pacific.
    Response: NMFS is aware of the active area of research in 
developing density models for data poor areas that extrapolate cetacean 
densities beyond surveyed regions. For example, the Navy and NMFS were 
reviewers of, and used, the results of Mannocci et al. (2017) in the 
U.S. Navy's Atlantic Fleet Training and Testing (AFTT) Study Area NEPA 
analysis and MMPA rulemaking. NMFS and the Navy will continue to 
discuss and examine the utility of these emerging models for estimating 
densities of marine mammals in the SURTASS LFA sonar Study Area. It is 
possible that the sighting results from the IWC-POWER cruises could be 
used to extrapolate density and abundance estimates throughout the 
North Pacific in the future, using the methods developed by Mannocci et 
al. (2015) that were applied to extrapolate density estimates in the 
North Atlantic (Mannocci et al., 2017). Cruise reports through 2017 are 
available online, with cruises continuing for another few years. When 
additional results are available, NMFS and the Navy will consider use 
of these methods to extrapolate density and abundance estimates that 
could inform mitigation through Adaptive Management process, or to 
inform analyses for future actions. Lambert et al. (2014) used the 
simulated distribution of micronekton from the Spatial Ecosystem And 
Population Dynamics Model (SEAPODYM) to predict the habitat of three 
cetacean guilds in tropical waters. While their results provide some 
interesting insights into the use of predicted prey maps in cetacean 
distribution models, they are best used to prioritize future research 
areas. Corkeron et al. (2011) developed statistical methods for using 
spatially autocorrelated sighting results to identify the Dhofar coast 
of Oman as an important region for the Arabian Sea DPS of humpback 
whales. However, the Dhofar coast of Oman is outside of the SURTASS LFA 
sonar Study Area and Corkeren et al. state ``Although it is 
theoretically possible for us to project model predictions into other 
areas, we consider this inadvisable, as our basic design was not to 
make inference about the distribution of humpback whales along the 
entire Oman coast.'' Therefore, though its statistical models could be 
applied to sightings data within the SURTASS LFA Study Area, these 
humpback whale results are not applicable. When considering how to 
predict marine mammal densities across large spatial scales using many 
varied datasets, there are often multiple appropriate and effective 
ways that data can be modeled and extrapolated, and NMFS does not 
prescribe any particular model in these cases, as long as our review 
indicates that the proposed method is supportable. Here, the densities 
and modeling used reflect the best available science and, further, 
monitoring of SURTASS activities from the past 17 years of activities 
do not suggest that these models have underestimated marine mammal 
exposure.
    Comment 4: The Commission recommended that, in the preamble to the 
final rule, NMFS specify how density estimates were derived and what 
statistic (e.g., mean, median, maximum) was used when multiple sources 
are referenced in Tables 2-16 of the Federal Register notice and Table 
3-2 of the revised LOA application.
    Response: We have included the density estimate and associated 
reference or references for each species/stock in each of the 15 
Representative Modeling Areas in the SURTASS LFA sonar Study Area in 
Tables 2 through 16 of this rule. Additional details on the densities 
used for each species/stock in each modeling area are provided in the 
2019 SURTASS LFA FSEIS/SOEIS (Chapter 3, Table 3-8 and Appendix D). In 
Chapter 3, Table 3-8 2019 SURTASS LFA FSEIS/SOEIS, multiple references 
are provided to reflect references used to support the population 
density estimate and seasonality of occurrence. In Tables 2-16 of this 
rule we have included only the reference to the density estimate. 
Appendix D of the 2019 SURTASS LFA FSEIS/SOEIS includes detailed 
descriptions and references for each species/stock in each of the model 
areas that include how each density estimate was derived. In response 
to this comment the Navy has also reviewed and revised the descriptions 
in Appendix D of the 2019 SURTASS LFA FSEIS/SOEIS to increase clarity.
    Comment 5: With respect to estimated densities of cetaceans in 
Offshore Guam, the Commission recommended that NMFS use the densities 
stipulated in Department of the Navy (2018b) for blue whales, Bryde's 
whales, fin whales, ginkgo-toothed beaked whales, and Deraniyagala's 
beaked whales rather than the densities in Table 5 of the Federal 
Register notice and re-estimate the numbers of takes accordingly in the 
final rule.
    Response: As recommended, we have revised the densities for blue 
whales, Bryde's whales, fin whales, ginkgo-toothed beaked whales, and 
Deraniyagala's beaked whales to those presented in the U.S. Navy marine 
species density database Phase III for the Mariana Islands Training and 
Testing Study Area (DoN, 2018b) and have revised our estimated takes of

[[Page 40140]]

these species/stocks in the Offshore Guam modeling area accordingly.
    Comment 6: NRDC et al. recommended that NMFS require the Navy to 
conduct baseline research in unsurveyed areas that it repeatedly 
employs in LFA sonar operations, prioritizing areas on the basis of 
exposure frequency, environmental vulnerability, and research 
feasibility.
    Response: Per the Council on Environmental Quality (CEQ) regulation 
40 CFR 1502.22, the Navy has indicated plainly in the 2019 SURTASS LFA 
FSEIS/SOEIS where data or information are lacking to support Navy 
analyses and how the Navy has resolved the issue of scarcity of data/
information (i.e., surrogate data/information). The Navy is not 
required to conduct costly baseline research, such as that suggested, 
to obtain incomplete or unavailable data and information for areas in 
which the Navy operates LFA sonar (CEQ Regulation 1502.22). Further, 
the ESA and MMPA only require that a Federal agency consider the best 
available data, and do not require the agency generate the data itself. 
However, as noted in this rule, the Navy does fund ongoing research and 
conservation related to marine mammals. The Navy sponsors a significant 
portion of the U.S. research on the effects of human-generated sound on 
marine mammals (between approximately 25 to 30 million dollars per year 
on marine mammal research from the Navy's three main programs: Office 
of Naval Research, Living Marine Resources Program, and the Fleet/
SYSCOM monitoring programs), which is crucial to the overall knowledge 
base on the potential for effects from underwater anthropogenic noise 
on marine mammals (82 FR 19460, 19516; April 27, 2017). See Office of 
Naval Research (https://www.onr.navy.mil/) and Navy Living Marine 
Resources program (https://navysustainability.dodlive.mil/environment/lmr/) for examples of Navy support research. The Navy also sponsors 
research to determine marine mammal abundances and densities for all 
Navy ranges and other operational areas (see Marine Species Monitoring 
Program: https://www.navymarinespeciesmonitoring.us/). As described in 
the Description of Marine Mammals in the Area of the Specified 
Activities section of the rule and Chapter 3 and Appendix D of the 
SURTASS LFA FSEIS/SOEIS, the Navy used a combination of density 
estimates from a region with similar oceanographic characteristics to 
that model area, estimates derived from the Navy's Marine Species 
Density Database (DoN, 2018), and pooled density estimates for species 
of the same genus if sufficient data were not available to compute a 
density for individual species or the species are difficult to 
distinguish at sea (e.g., Mesoplodon spp. and Kogia spp.) to inform 
their analyses in unsurveyed areas, which NMFS concurred represented 
the best available science.
Permanent Threshold Shift (PTS)/Temporary Threshold Shift (TTS) 
Thresholds and Take Estimates
    Comment 7: The Commission recommended that NMFS (1) specify the 
numbers of model-estimated Level A harassment (PTS) takes of marine 
mammals in the absence of implementing mitigation measures and any and 
all assumptions (including within the animat modeling scenarios) that 
were made to reduce those takes to zero in the preamble to the final 
rule and (2) authorize the model-estimated Level A harassment (PTS) 
takes rather than reducing them to zero in the final rule. The 
Commission stated that specifics regarding the situations in which 
those takes were estimated to occur (i.e., distances to the source and 
timeframe over which the exposure occurred) should be delineated in the 
preamble to the final rule as well.
    Response: The Navy quantitatively assessed the potential for PTS 
and TTS resulting from exposure to SURTASS LFA sonar transmissions 
using NMFS' 2018 Acoustic Technical Guidance for estimating impacts of 
PTS and TTS using AIM. In AIM the potential for PTS is considered 
within the context of the mitigation and monitoring efforts that would 
occur whenever SURTASS LFA sonar is transmitting. Mitigation monitoring 
is designed to detect marine mammals before they are exposed to a 
received level of 180 dB re: 1 [mu]Pa SPL. The probability of detection 
of a marine mammal by the HF/M3 system alone within the LFA sonar 
mitigation zone approaches 100 percent over the course of multiple 
pings (see the 2001 SURTASS LFA FOEIS/EIS, Subchapters 2.3.2.2 and 
4.2.7.1 for the HF/M3 sonar testing results as well as section 5.4.3 of 
the 2019 SURTASS LFA FSEIS/SOEIS for a summary of the effectiveness of 
the HF/M3 system). As described in the Estimated Take of Marine Mammals 
section, with the implementation of the three-part monitoring programs 
(visual, passive acoustic, and HF/M3 monitoring, as discussed below), 
NMFS and the Navy do not expect that marine mammals would be injured by 
SURTASS LFA sonar because a marine mammal is likely to be detected and 
active transmissions suspended or delayed to avoid injurious exposure. 
Therefore, in incorporating mitigation, AIM assumes no animats will be 
exposed to SURTASS LFA sonar in the LFA sonar mitigation zone. AIM 
records the exposure history for each individual animat and the 
potential impact is determined on an individual animal basis. The sound 
energy received by each individual animat over the 24-hr modeled period 
was calculated as sound exposure level (SEL) and the potential for that 
animal to experience PTS and then TTS was considered using the NMFS 
(2018) acoustic guidance thresholds. When mitigation is applied in the 
modeling-analysis environment, estimations of PTS impacts were 0 for 
all marine mammal species in all model areas.
    Therefore, the Navy did not request and NMFS is not authorizing 
Level A harassment take. As presented in the Estimated Take of Marine 
Mammals section, based on simple spherical spreading (i.e., 
transmission loss based on 20 x log10 [range {m{time} ]), all hearing 
groups except LF cetaceans would need to remain within 22 ft (7 m) for 
the entire duration (60 sec) of an LFA sonar ping to potentially 
experience PTS. LF cetaceans would need to remain at the greatest 
distance from the transmitting LFA sonar, 135 ft (41 m) before 
experiencing the onset of PTS. This distance is well within the LFA 
sonar mitigation zone and a distance where visual, passive, and 
acoustic monitoring can reliably detect small and large marine mammals 
100 percent of the time and transmission can shut down before any 
injury can occur. NMFS has determined that the suite of mitigation 
monitoring efforts is highly effective at detecting marine mammals and 
avoiding Level A take and notes that there have been no reported or 
known incidents of Level A harassment of any marine mammal in 17 years 
of SURTASS LFA sonar activities. Therefore, NMFS has determined that 
authorizing Level A harassment take is not warranted.
    Comment 8: The Commission recommended that NMFS explain why TTS 
takes are greater than behavior takes for some species of mysticetes, 
or stocks of mysticetes within the same species, in the preamble to the 
final rule.
    Response: The estimated Level B harassment takes presented in 
Chapter 4 of the 2019 SURTASS LFA FSEIS/SOEIS are correct. Table 18 in 
this final rule presents total Level B Harassment takes (including both 
behavioral disruption and TTS). In the vast majority of mysticete 
species/stocks, estimated takes by behavioral disruption

[[Page 40141]]

are greater than estimated incidents of TTS; however, in a few cases 
the predicted numbers of TTS are higher than the estimated takes by 
behavioral disruption. This is due to the way these two impacts are 
assessed. The TTS acoustic threshold level is based on cumulative SEL 
metric and a take occurs when a marine mammal exposed to sounds above 
the threshold level (a step function where 0 is no take and 1 is a take 
for each individual). Behavioral response is calculated for each 
individual on a continuum from 0 to 1 based on the marine mammals 
single ping equivalent (SPE) value. Therefore, many more marine mammals 
may be (and typically are) exposed at sound (SPE) levels with a very 
low risk for a behavior response (less than 1). When these risk values 
are summed to calculate the estimated take due to behavioral response, 
the result may be an estimate that is lower than the estimate for TTS. 
In their response to comments in the SURTASS LFA FSEIS/SOEIS, the Navy 
provides the following example to illustrate: If the blue whale has a 
hypothetical population estimate of 10 individuals, one animal may 
experience TTS, five may have some percent risk of a behavioral 
response, and four may not be impacted. Estimating take, one animal is 
predicted to experience TTS. The five animals in the population have 
potential behavioral response (risk values) of 0.5, 0.2, 0.05, 0.04, 
and 0.01. When summed, this is 0.8 for the entire population. 
Therefore, the risk of TTS (1 animal) is greater than the risk of 
behavioral response (0.8 animal), but the number of animals 
experiencing TTS (one) is less than the number that have the potential 
to experience a behavioral response (five).
Behavioral Harassment Thresholds and Take Estimates
    Comment 9: With respect to SPE as the metric to estimate behavioral 
response, the Commission recommended that NMFS use either (1) a metric 
(i.e., SPL or sound exposure level (SEL)) and associated thresholds 
that are based on physics rather than SPE or (2) the behavioral 
response metrics and thresholds that the Navy currently uses for all 
other LF sonar sources based on Department of the Navy (2017b) to 
estimate behavior takes for the final rule. NRDC et al. also stated 
that given the lack of any tenable justification for maintaining an SPE 
approach, NMFS, and the Navy, should use the more widely accepted, more 
conservative SEL in determining the effect of multiple exposures on 
marine mammals.
    Response: The behavioral risk function is based on field 
measurements of behavioral responses of mysticetes during the SURTASS 
LFA Sonar Low Frequency Sound Scientific Research Program (LFS SRP). 
SPE was developed by researchers in the LFS SRP to account for received 
energy from all LFA sonar transmissions that a modeled animal 
(``animat'') receives during a 24-hr period of a SURTASS LFA sonar 
mission. SPE was also designed to approximate the manner in which the 
effect of repeated exposures accumulate, as known from studies on 
humans (Kryter, 1985; Richardson et al., 1995; Ward, 1968). SPE 
accounts for the increased potential effect of repeated exposures on 
animals by adding 5 x log10 (number of pings) to each 1-dB received 
level (RL) increment (Kryter, 1985; Richardson et al., 1995; Ward, 
1968). If an individual's exposure within a 24-hour period is dominated 
by a single loud pulse, the SPE will not be greater than the SPL (rms) 
of that single loud pulse. However, if there are two or more pulses of 
the same amplitude, the calculated SPE will be greater than the SPL 
(rms) of a single pulse because the SPE metric accounts for 
accumulation, and SPL does not. Therefore, the calculated SPE is never 
lower than the SPL rms of the loudest pulse.
    The SEL metric is used to determine physiological effects (PTS and 
TTS) and the Navy's rulemaking and LOA application, as well as this 
final rule, use the SEL metric to estimate these impacts as described 
in the NMFS' 2018 Acoustic Technical Guidance. Research indicates that 
behavioral responses are context specific and due to both received 
level and a suite of other factors including behavioral context. All 
other applicants use SPL thresholds for assessing Level B harassment by 
behavioral disruption, and the Navy uses SPL based risk functions for 
all of its other training and testing activities, which utilize sound 
sources of shorter pulse lengths. Since SPE allows for a consideration 
of the duration of a signal and is always more conservative than SPL 
rms values, it is equal to or more conservative than an SPL based risk 
function and NMFS concurs with its use with SURTASS LFA sonar.
    Although the LFS SRP study is from the late 1990s, the source used 
was the most similar in source characteristics and operating parameters 
to the SURTASS LFA sonar source, and most closely matches the nature 
and context of the Navy's current activity. Specifically, the multiple 
LF sources that may be used in the Navy's major training exercises 
(such as AFTT and HSTT) include sources that are operated differently, 
are operated at different frequencies, and are only one component of 
any training activity -- and for these reasons, the Navy and NMFS found 
it appropriate to apply the thresholds and modeling utilized for the 
other active Navy sources. However, for SURTASS, the results of the LFS 
SRP remain the best available data for the purpose of predicting 
potential impacts from exposure to SURTASS LFA sonar as they evaluated 
the behavioral responses of LF hearing specialists conducting 
biologically important behaviors to exposures of SURTASS LFA sonar. 
NMFS and the Navy have evaluated the science conducted with other sound 
sources (e.g., mid-frequency sonar, the European ``low-frequency active 
sonar'' that operates at 1-2 and 6-7 kHz) and no newer data change the 
prediction of expected behavioral responses.
    Comment 10: The Commission recommended that NMFS and the Navy 
prioritize conducting a behavioral response study (BRS) using updated 
BRS methods involving SURTASS LFA sonar and mysticetes, other 
odontocetes including sperm whales, and/or phocids under the monitoring 
requirements for the final rule and ensure that the behavior thresholds 
are able to be updated accordingly before the next rulemaking.
    Response: The Navy has agreed to evaluate the feasibility and 
appropriate methods to collect new data to supplement the data 
available on behavioral responses of marine mammals to SURTASS LFA 
sonar using newer methods and technologies. These types of scientific 
inquiries fit within the scope the Navy's Living Marine Resources (LMR) 
program. The LMR program weighs the various Navy research needs against 
each other through a needs and solicitation process. The Navy has 
submitted a needs statement to the LMR advisory committee to research 
future data collection that would supplement understanding of how 
SURTASS LFA sonar may affect marine resources, including mysticetes and 
beaked whales.
    Comment 11: NRDC et al. noted that the proposed rule analysis 
relies entirely on the LFA Scientific Research Program (SRP) in 
establishing behavioral risk parameters for the SURTASS LFA system. 
They noted that study took place twenty years ago and is inconsistent 
with more recent science on the behavioral response of marine mammals 
to low-frequency underwater noise. They stated that reliance on the SRP 
to the exclusion of all other scientific literature on the impacts of

[[Page 40142]]

low-frequency sound would be arbitrary and capricious. NRDC et al. 
noted that marine mammal science, including the technology used to 
study behavioral response to underwater noise, has advanced 
significantly over the two decades since the SRP concluded. They stated 
that the tags used in the SRP were Time-Depth Recorders, which, in 
rendering only depth profile, are primitive by comparison with 
contemporary marine mammal tags, which include accelerometers, 
magnetometers, and hydrophones. The newer tags provide far greater 
capacity to track alterations in animal orientation, velocity, and 
noise production, and therefore to detect disruptions in marine mammal 
feeding and other behaviors. Additionally, they noted that the SRP's 
sample sizes were small, focal species were limited, and the LFA system 
was generally operated at less than full power. They noted that new 
technologies and methods indicate limitations of the Navy's research. 
They cited studies that observed reductions in buzz rates in sperm 
whales and harbor porpoises that could not have been observed without 
newly available technology (Miller et al., 2009; Pirotta et al., 2014).
    Response: As noted in the response to Comment 9, the data collected 
during the SURTASS LFA sonar LFS SRP studies remain the best available 
data for predicting behavioral responses to SURTASS LFA sonar. However, 
NMFS and Navy also considered other relevant studies on the potential 
effects of LF sound transmissions on marine mammals. None of these 
other studies contradict the conclusions of the LFS SRP (see the 
Potential Effects of the Specified Activity on Marine Mammals and their 
Habitat section in the proposed rule and Chapter 4 of the 2019 SURTASS 
LFA FSEIS/SOEIS for descriptions of studies). While we acknowledge the 
age of the SURTASS sonar LFS SRP data, the age of these data does not 
invalidate them, their contributions to science, nor the conclusions 
based upon those data. It is true that the technology and techniques 
available to gather marine animal data have become increasingly diverse 
and sophisticated over time and that LFS SRP sample sizes were small. 
The commenter points out the sorts of data that may be gathered 
utilizing new technologies and cites to the ``limitations'' of the SRP. 
NMFS acknowledges that newer methods may allow for additional data 
collection, however, in the meanwhile, NMFS and the Navy have 
considered all of the data, LFS SRP and otherwise, that are applicable 
to the SURTASS LFA sonar assessment and are aware of no basis to 
invalidate the overall results of the SRP. As noted in the response to 
Comment 10, the Navy will evaluate the feasibility and appropriate 
methods to collect new data to supplement the data available on 
behavioral responses of marine mammals to SURTASS LFA sonar.
    Comment 12: NRDC et al. noted that the Navy claims that the SRP 
remains more relevant than the host of more recent investigations 
because it is the only study of a tonal source operating at frequencies 
below 500 Hz. The commenters noted that researchers in the Stellwagen 
Bank National Marine Sanctuary documented suppression in humpback whale 
vocalization during operations of an Ocean Acoustic Waveguard Remote 
Sensing (OAWRS) system, a powerful low-frequency fish sensor operating 
at similar frequencies, at distances of 200 km from the source (Risch 
et al. 2012). The Heard Island Feasibility Test, which likewise 
involved a tonal sound source operating below 500 Hz, reported complete 
cessations in vocalizations of long-finned pilot whales and sperm 
whales over a 4900 km\2\ area following exposure (Bowles et al. 1994). 
They stated that these papers join a spate of other studies documenting 
large-scale changes in baleen whale vocalizations and those of other 
species in response to predominantly low-frequency anthropogenic noise 
(Nowacek et al., 2015) and that the best available science indicates 
that the Navy's behavioral response function for LFA, promulgated by 
NMFS in the Proposed Rule, is non-conservative.
    Response: We disagree that the LFA sonar behavioral response 
function is non-conservative. Discussion of additional studies on the 
behavioral responses of marine mammals to a variety of sound sources 
are provided in the Potential Effects of the Specified Activity on 
Marine Mammals and their Habitat section in the proposed rule and 
Chapter 4 of the 2019 SURTASS LFA FSEIS/SOEIS. As discussed in the 
proposed rule, the potential for behavioral response to an 
anthropogenic source is highly variable and context-specific. Also, as 
discussed in the proposed rule, the recorded OAWRS produced a series of 
frequency-modulated pulses and signal received levels. Risch et al. 
(2012) documented reduction in humpback whale vocalization concurrent 
with transmissions of the low-frequency OAWRS system at distances of 
200 km (108 nmi) from the source. The OAWRS source appears to have 
affected more whales than Phase III of the LFS SRP, even though 
exposure was at a lower RL (88 to 110 dB re: 1 [mu]Pa), which the 
authors noted was a novel sound source that provided a compelling 
contextual probability for the observed effects. Gong et al. (2014) 
assessed the effects of the OAWRS transmissions on calling rates on 
Georges Bank and determined constant vocalization rates of humpback 
whales, with a reduction occurring before the OAWRS system began 
transmitting. Risch et al. (2014) pointed out that the results of Risch 
et al. (2012) and Gong et al. (2014) are not contradictory, but rather 
highlight the principal point of their original paper that behavioral 
responses depend on many contextual factors, including range to source, 
RL above background noise level, novelty of signal, and differences in 
behavioral state. Further, the authors did not state or imply that the 
observed behaviors had long-term effects on individual animals or 
populations. The responses of whales to the OAWRS system are consistent 
with the LFA behavioral response function, as it estimates that 
behavioral changes can occur at received levels lower than 180 dB. 
Results from the Heard Island Feasibility Test (Bowles et al., 1994) 
show that during the pre-experiment baseline period, sperm whales were 
detected 24 percent of the time and short-finned pilot whales were 
detected eight percent of the time. During night-time recordings during 
the baseline period, sperm whales were detected eight percent of the 
time and pilot whales were detected zero percent of the time. Neither 
species was detected during the low-frequency transmissions, but both 
species were detected 36 h after transmissions ended. It is not known 
whether sperm and pilot whales were masked during the transmissions or 
whether they ceased vocalizing. Since sperm whales frequently become 
silent in the presence of anthropogenic noise (Watkins and Schevill, 
1975; Watkins et al., 1985), it is possible they exhibited a behavioral 
response.
    NMFS concurs with the use of the Navy's behavioral response 
function and that it conservatively estimates Level B harassment takes. 
There is no indication that this method underestimates take. While the 
entire ensonified area cannot be monitored (using visual or passive and 
active acoustic monitoring), marine mammal observations during SURTASS 
LFA sonar activity and those predicted using annual activity level and 
location indicate the Navy has never exceeded authorized take for 
SURTASS LFA sonar activities (with the first LOA for SURTASS LFA sonar 
activities

[[Page 40143]]

beginning in August 2002). The potential for behavioral response to an 
anthropogenic source is highly dependent on context, including 
characteristics of the sound signals and their pattern of transmission, 
the environmental factors affecting sound movement, and the behavioral 
state of the animal during exposure. Further, not every response of a 
marine mammal rises to the level of a take, and some of the responses 
cited by the commenter would not necessarily do so (e.g., minor 
modifications in vocalizations of a duration shorter than exposure to 
the signal). As previously noted, the SURTASS LFS SRP exposed LF 
specialist cetaceans engaged in biologically important behaviors to 
real-world SURTASS LFA sonar transmissions; the SRP results remain the 
best available science for assessing potential impacts associated with 
exposure to SURTASS LFA sonar. The SURTASS LFS SRP experiments exposed 
baleen whales to RLs ranging from 120 to about 155 dB re: 1 [micro]Pa 
rms SPL and detected only minor, short-term behavioral responses. 
Short-term behavioral responses do not necessarily constitute 
significant changes in biologically important behaviors. The behavioral 
response function is also conservative for non-LF specialists, as it 
was developed for species believed to be most sensitive to SURTASS LFA 
sonar. Therefore, although the results of the risk function modeling 
are interpreted such that they would constitute ``significant 
disruptions to biologically important behaviors,'' (i.e., causing 
disruption of natural behavioral patterns, including, but not limited 
to, migration, surfacing, nursing, breeding, feeding, or sheltering, to 
a point where such patterns are abandoned or significantly altered) not 
all predicted exposures would in fact rise to such a level, and the 
resulting risk function modeling is conservative for all marine 
mammals.

Mitigation and Monitoring

Least Practicable Adverse Impact Determination
    Comment 13: The Commission noted that NMFS' interpretation of the 
least practicable impact standard in various proposed rules has been an 
evolving one, and it is unclear that any of those discussions, targeted 
to specific instances, should be considered to constitute a formal 
interpretation. Rather, it is a shifting target that requires the 
Commission and other stakeholders to comment repeatedly on the various 
permutations. The Commission stated that such generally applicable 
policies and interpretations should be developed through a separate 
rulemaking (e.g., in amendments to 50 CFR 216.103 or 216.105) or policy 
statement rather than in individual incidental take authorizations and 
recommended that NMFS pursue such a rulemaking or publish a proposed 
policy for public review and comment. The Commission expressed concerns 
that some stakeholders may not be aware of or choose not to comment on 
the proposed interpretation in this context, because the particular 
authorization may not otherwise be of interest to them (e.g., because 
the activity is in a geographical location or concerns a type of 
activity not of particular interest).
    Response: We appreciate the Commission's recommendation and may 
consider the recommended approaches in the future. We note, however, 
that providing relevant explanations in a proposed incidental take rule 
is an effective and efficient way to provide information to the reader 
and solicit focused input from the public, and ultimately affords the 
same opportunities for public comment as a stand-alone rulemaking 
would. NMFS has provided similar explanations of the least practicable 
adverse impact standard in other recent section 101(a)(5)(A) rules, 
including: the final rules for U.S. Navy Training and Testing 
Activities in the Atlantic Fleet Study Area (83 FR 57076; November 14, 
2018) and the Hawaii-Southern California Study Area (83 FR 66846; 
December 21, 2018), as well as the proposed rule for Geophysical 
Surveys Related to Oil and Gas Activities in the Gulf of Mexico (83 FR 
29212; June 22, 2018).
    Comment 14: The Commission stated that in its previous letters it 
recommended that NMFS adopt a two-step approach when applying the least 
practicable adverse impact standard. First, it should identify the 
criteria it will use to determine whether adverse impacts on marine 
mammal species/stocks or their habitat are anticipated. If potential 
adverse impacts are identified, the second step should be to determine 
whether measures designed to reduce those impacts are available and 
practicable. The Commission expressed concern that, because NMFS' 
criteria for applying the least practicable adverse impact standard 
commingle elements related to whether impacts are adverse and whether 
potential mitigation measures are likely to be effective, NMFS' 
analysis is not as clear as it should be. The Commission therefore 
recommended that NMFS rework its evaluation criteria for applying the 
least practicable adverse impact standard to separate the factors used 
to determine whether a potential impact on marine mammals or their 
habitat is adverse and whether possible mitigation measures would be 
effective.
    Response: The Commission recommends NMFS consider applicable 
factors in its least practicable adverse impact analysis in a specific 
manner. However, it did not provide any suggested criteria for 
determining its recommended first step.
    NMFS has clearly articulated the agency's interpretation of the 
LPAI standard and our evaluation framework in the Mitigation section of 
this notice. Specifically, NMFS identified the adverse impacts that it 
is considering in the LPAI analysis and comprehensively evaluated an 
extensive suite of measures that might be available to reduce those 
impacts (some of which are adopted and some that are not) both in the 
context of their expected ability to reduce impacts to marine mammal 
species or stocks and their habitat, as well as their practicability 
(see Mitigation and Negligible Impact Analysis and Determination 
sections). In the Mitigation section, NMFS has explained in detail our 
interpretation of the least practicable adverse impact standard, the 
rationale for our interpretation, and our approach for implementing our 
interpretation. The ability of a measure to reduce effects on marine 
mammals is entirely related to its ``effectiveness'' as a measure, 
whereas the effectiveness of a measure is not connected to its 
practicability. NMFS' interpretation of the LPAI standard is a 
reasonable interpretation that gives effect to the language in the 
statute and the underlying legislative intent. Congress intended the 
agencies administering section 101(a)(5)(A) to consider practicability 
when determining appropriate mitigation, but we do not believe the 
analysis must be conducted in such a rigid sequential fashion. There is 
a tension inherent in the phrase ``least practicable adverse impact'' 
in that ``least [. . .] adverse impact'' pulls in favor of one 
direction (i.e., expanding mitigation) while ``practicable'' pulls in 
favor of the other direction (i.e., limiting mitigation), and weighing 
the relative costs and benefits is, in our view, a more meaningful way 
to address and resolve this tension. Contrary to the Commission's 
suggestion, there is no formulaic way to do this. As we explained in 
the discussion of the LPAI standard above using a simple hypothetical 
example to illustrate the point, means of minimizing adverse impacts at 
the species or stock level is not a black and white proposition. 
Further, the standard is accomplished

[[Page 40144]]

through mitigation imposed for individuals--yet the standard does not 
require that we minimize individual takes or impacts to the maximum 
extent practicable.
    NMFS' approach laid out in this rulemaking acknowledges that, even 
when the negligible impact standard is met, NMFS must still consider 
mitigation under the LPAI standard. NMFS' approach recognizes that 
impacts to species or stocks of marine mammals accrue through 
individuals and, as such, allows for reducing impacts on individuals, 
but with a focus on measures designed to avoid or minimize impacts on 
marine mammals that are likely to increase the probability or severity 
of population level effects. The greater the likelihood that a measure 
will contribute to reducing the probability or severity of adverse 
impacts to a species or stock, the greater the weight that measure is 
given when considered in combination with practicability to determine 
the appropriateness of a mitigation measure. While the analysis we 
describe can be conducted for each measure, we read the ``means of 
effecting the LPAI'' standard as ultimately applying to the totality of 
all required measures taken together. Accordingly, NMFS can take into 
account other measures that will be implemented when considering the 
benefit of additional measures. NMFS has weighed the relevant 
considerations as explained in its fuller discussion of LPAI.
    While the Ninth Circuit's opinion in Pritzker (83 F.3d 1125 (9th 
Cir. 2016)) did not directly address this question, the Court appeared 
to view NMFS' conceptual approach of weighing various considerations as 
an acceptable one. In response to our 2012 rule, where we described our 
approach as including ``a careful balancing of the likely degree to 
which the measure is expected to minimize adverse impacts to marine 
mammals with the likely effect of that measure on personnel safety, 
practicality of implementation, and impact on the effectiveness of 
military readiness activity,'' the Court said ``this formulation makes 
sense so far as it is stated,'' Pritzker, 828 F.3d at 1135 (emphasis 
added), though faulted NMFS for not meaningfully discussing how the 
measures it imposed would meet that standard. The legislative history 
on the 2004 MMPA amendments for military readiness activities provides 
further support, in that it shows Congress intended additional weighing 
for military readiness impacts and placed equal import on the 
military's need to conduct training activities. 2004 U.S.C.C.A.N. at 
1447 (stating that the changes with the MMPA ``properly balance the 
equities associated with military readiness and maritime species 
protection'').
    Comment 15: The Commission stated that section 
101(a)(5)(A)(i)(II)(aa) of the MMPA specifies that incidental take 
regulations are to set forth permissible methods of taking pursuant to 
such activity, and other means of effecting the least practicable 
adverse impact on such species or stock and its habitat, paying 
particular attention to rookeries, mating grounds, and other areas of 
similar significance. The Commission stated that in this case, NMFS has 
only identified in the most general sense the means it will use to 
effect the least practicable adverse impact--it will identify and 
impose heightened protections in as yet unidentified OBIAs--and has 
provided no information to assess when and where NMFS believes it would 
be practicable for the Navy to abide by those exclusions. Only at the 
final rule stage would NMFS generate a list of the areas that meet the 
OBIA criteria, provide its rationale for determining which areas 
satisfy those criteria, and discuss whether requiring the Navy to 
employ mitigation measures in and near those areas would be 
practicable. The Commission stated that this approach is inconsistent 
with how NMFS has handled every previous rulemaking involving the 
Navy's activities, and more importantly, is inconsistent with the 
requirements of the Administrative Procedure Act (APA), which requires 
that NMFS give the public a meaningful opportunity to comment on what 
the agency is proposing. In this instance, the public is not being 
given a meaningful opportunity to comment on which OBIAs are 
appropriate to include in the final rule. Rather, commenters are left 
to speculate on which OBIAs NMFS might select and to comment in a 
vacuum as to whether those would be practicable for the Navy to meet 
its operational goals if some or all of the OBIAs that meet the 
criteria are included in the final rule. The Commission recommended 
that, in this and other proposed rules, NMFS inform the public what 
measures it is proposing to include in the final rule to satisfy the 
requirements of section 101(a)(5)(A)(i)(II)(aa) of the MMPA rather than 
leaving the public to speculate on all of the possibilities and the 
practicability of implementing them.
    Response: NMFS disagrees with both the Commission's description of 
the lack of information that NMFS provided the public in the proposed 
rule and the assertion that it was inconsistent with the requirements 
of the APA. NMFS described a clear proposed process and detailed set of 
factors that would be used to identify OBIAs, both prior to the 
finalization of the rule, as well as adaptively throughout the course 
of the rule. Further, NMFS provided the public with a carefully 
evaluated and honed list (reduced from hundreds considered, down to 25 
presented) of potential OBIAs that preliminarily met the biological 
criteria (in addition to the four that were already established for the 
geographic areas included in the Study Area) to provide input on. NMFS 
systematically described these OBIA candidates in the context of the 
OBIA process and factors and indicated all of the references from which 
the supporting information was obtained. The public was given adequate 
information upon which to base input on this mitigation, as required by 
the APA. The fact that the practicability of these areas for the Navy 
was not discussed in the proposed rule did not prevent the public from 
providing meaningful input on the information and potential OBIAs 
presented.
    Comment 16: The Commission noted that the analysis provided in the 
Federal Register notice seems to conflate the species and habitat 
portions of the least practicable adverse impact standard. NMFS 
discussed the distinction between impacts on individual marine mammals 
versus impacts on species and stocks in some detail. However, that 
distinction is irrelevant when considering adverse impacts to important 
marine mammal habitat such as rookeries, mating grounds, and areas of 
similar significance. All of these types of areas are important at the 
species or stock level. Further, the Commission stated that it believes 
all of the areas that meet the OBIA designation criteria constitute 
important habitat for purposes of implementing section 
101(a)(5)(A)(i)(II)(aa) of the MMPA and that mitigation measures to 
avoid or reduce adverse impacts to all of those areas should be 
included in the final rule unless such measures are not practicable. 
The Commission therefore recommended that, in the final rule, NMFS 
again require that the Navy ensure that none of the areas designated as 
OBIAs (or the 1 km buffer zones around them) are subjected to SURTASS 
LFA sonar received levels of 180 dB re 1 [mu]Pa or greater. Further, 
because the proposed rule did not include any information that 
indicates it would be impracticable for the Navy to adhere to such a 
limitation for any of the OBIAs under consideration, the Commission 
recommended that this mitigation

[[Page 40145]]

measure apply to all areas the Commission recommended be designated as 
OBIAs herein. If NMFS or the Navy believes it would be impracticable to 
implement the identified measures in any of those areas, then NMFS 
should make that case in a subsequent Federal Register notice and 
provide the public with an opportunity to comment on any proposed 
exceptions before adopting them.
    Response: NMFS disagrees with the Commission's assertion that NMFS 
conflates the species and habitat portions of the LPAI standard. NMFS 
recognizes the LPAI standard includes a requirement to prescribe 
measures that will effect the least practicable adverse impact on both 
the affected species or stocks and their habitat. In our description of 
implementation of the standard, we state that reduction of habitat 
impacts is relevant, particularly as it relates to rookeries, mating 
grounds, and areas of similar significance, and can include measures to 
reduce impacts of an activity on known prey utilized in the area or 
reducing impacts on physical habitat. Our discussion of least 
practicable adverse impact points out that because habitat value is 
informed by marine mammal presence and use, in some cases there may be 
overlap in measures for the species or stock and for use of habitat. 
Here we have identified time-area restrictions based on a combination 
of factors that include higher densities and observations of specific 
important behaviors of the animals themselves, but these also clearly 
reflect preferred habitat. In addition to being delineated based on 
physical features that drive habitat function (e.g., bathymetric 
features, among others), the high densities and concentration of 
certain important behaviors (e.g., feeding) in these particular areas 
clearly indicates the presence of preferred habitat. Just because the 
OBIAs address both marine mammals and their habitat does not mean that 
NMFS has conflated the two pieces of the standard. The MMPA does not 
specify that effects to habitat must be mitigated in separate measures, 
and NMFS has clearly identified measures that provide for mitigation of 
impacts to both marine mammal ``species or stocks and their habitat,'' 
as required by the statute.
    Further, this rulemaking evaluated the effects of SURTASS LFA sonar 
activities on marine mammal habitat, specifically including prey, and 
concluded that marine mammal prey will not be exposed to sustained 
duration and intensity of sound levels that would result in significant 
adverse effects to marine mammal food resources. Accordingly, no 
additional mitigation for habitat beyond the geographic based measures 
identified to minimize impacts on the affected species or stocks while 
using/occurring in certain preferred habitat (such as OBIAs), or the 
coastal standoff range was warranted.
    To the Commission's last point, in consideration of input from the 
public and our final evaluation, NMFS identified 17 areas (in the form 
of 14 OBIAs) as satisfying the necessary biological and geographic 
qualifications for OBIA designation and the Navy found that the 
implementation of all of these areas as OBIAs would be practicable. 
Accordingly, all 14 OBIAs are included in the final regulations.
    Comment 17: NRDC et al. expressed concern that NMFS, in its 
discussion of the LPAI standard, has set forth an interpretation that 
remains inconsistent with the plain language of the MMPA and with the 
Court's ruling in Pritzker (83 F.3d 1125 (9th Cir. 2016)). NRDC et al. 
stated that the agency reserves its consideration of mitigation 
measures to those that ultimately ``are likely to increase the 
probability or severity of population-level effects'' (84 FR 7228), and 
that it appears to base this understanding on an imputation of 
population-level harm into the ``least practicable adverse impact'' 
standard, and particularly into the standard's reference to ``such 
species or stock.'' NRDC et al. stated that the Court in NRDC v. 
Pritzker specifically rejected this assumption when the agency 
attempted to import it into the statute via its existing regulations 
concerning ``negligible impact.'' NRDC agreed with NMFS that the 
reduction of impacts to affected species or stocks ``accrues through 
the application of mitigation measures that limit impacts to individual 
animals'' and, consistent with this, ``focuses on measures that are 
designed to avoid or minimize impacts on individual marine mammals'' 
that, in turn, ``are likely to increase the risk of population-level 
effects'' (citing to 84 FR 7228). They cite as an example that the 
agency recognizes measures ``limiting interruption of known feeding, 
breeding, mother/young, or resting behaviors'' as having ``greater 
value'' for mitigation. However, NRDC stated that NMFS' formulation 
remains problematic in practice. NRDC stated that in detaching itself 
from the MMPA's ``take provision,'' it creates ``vagueness that leaves 
the provision open to inconsistent, arbitrary application'' and that 
the proposed rule appears to wander beyond the interpretation that NMFS 
sets down when it rejects the White Paper (Identifying Areas of 
Biological Importance to Cetaceans in Data-Poor Regions) guidelines to 
establish OBIAs in data-poor regions. NRDC et al. state that the 
proposed rule: ``does so on the grounds [. . .] that establishing OBIAs 
would not further reduce fitness consequences (i.e., `the potential for 
impacts on reproduction or survival') in individual marine mammals and 
thus would not reduce the probability of population-level harm. Id. at 
7247. Yet this is an ostensibly higher bar than is articulated by the 
agency in its section interpreting the least practicable adverse impact 
standard, requiring actual reduction of fitness impacts rather than 
reduced disruption of behavioral responses associated with fitness. 
Compare id. at 7229 (listing factors having `greater value' for 
mitigation to include `limiting interruption of known feeding, 
breeding, mother/young, or resting behaviors'). Putting aside the 
inconsistency with the statute, discussed above, our practical concern 
is that NMFS' interpretation will be used as a convenient legal 
defense--just as it was in Pritzker--to prop up an insufficient 
analysis. NMFS should ensure that it applies the ``least practicable 
adverse impact'' standard in a manner that reduces the impacts (e.g., 
Level A and Level B harassment take) that Congress intended to prohibit 
in adopting the MMPA.''
    Response: NMFS' interpretation and implementation of the LPAI 
standard is not inconsistent with the statute or the Pritzker decision, 
as described in the Mitigation section of this rule (and not re-
included here). We interpret the LPAI standard as having a species or 
stock-level focus but believe 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. NMFS acknowledges that it is 
not a mathematical formula; in evaluating a measure, consideration of 
its value and its practicability will necessarily involve exercise of 
the agency's professional judgment taking into account the specified 
activity and other contextual factors. NMFS' rule fully discusses its 
evaluation applying the standard it sets forth. Moreover, there is no 
inconsistency in the standard and the application in view of the full 
discussion in this rule. The language quoted in the comment cannot be 
isolated from the context of the full

[[Page 40146]]

discussion in the rule and then cited as proof of inconsistency. 
Specifically, to support its assertion, NRDC points to our rationale 
for not adopting the recommendations in the White Paper (discussed in 
detail in the Mitigation section). The comment mischaracterizes our 
conclusions by suggesting our reasoning is based solely on the fact 
that the recommendations in the White Paper will not further reduce 
fitness consequences of individuals and thus would not reduce 
population level harm. This ignores the fuller discussion, in which our 
assessment shows that the proposed mitigation would add little, if any, 
value for lowering the probability or severity of impacts to individual 
marine mammal fitness, but also that it is highly impracticable for the 
Navy. Thus, the White Paper recommendations were not adopted based on a 
straightforward application of the LPAI standard.

Procedural Mitigation Effectiveness and Recommendations

    Comment 18: The Commission recommended that, in the final rule, 
NMFS require the Navy to (1) use a 30-minute clearance time when a 
marine mammal has not been observed to have left the mitigation zone, 
consistent with other Navy activities and (2) conduct post-activity 
monitoring including visual, passive acoustic, and active acoustic 
monitoring for 30 rather than 15 minutes.
    Response: A 30-minute post monitoring timeframe is more widely used 
in other authorizations mainly due to the fact that marine mammal 
detections are largely reliant on visual surveys and this time accounts 
for marine mammals with longer-duration dives. In addition to visual 
and passive acoustic monitoring, the HF/M3 (active acoustic monitoring 
system) is used with SURTASS LFA sonar activities. Detection through 
active acoustics is typically not used with authorizations for other 
activities. However, given the near 100 percent effectiveness of the 
HF/M3 system with multiple pings (see response to Comment 7), in 
combination with the two other mitigation monitoring efforts (visual 
and passive acoustic monitoring), NMFS feels confident that any marine 
mammals present in the mitigation zone would be detected within the 15-
minute timeframe.
    Comment 19: The Commission noted that it does not appear that the 
Navy has conducted a study to investigate the effectiveness of the 
suite of mitigation measures currently being employed or proposed for 
SURTASS LFA sonar activities and that such a study would be prudent. 
The Commission noted that determination of effectiveness has been based 
solely on what has been ``observed'' via the three monitoring methods 
and some theoretical assumptions. True ``effectiveness'' studies 
evaluate not only the animals that are detected, but also those that 
are missed. The Navy is conducting a lookout effectiveness study to 
assess the effectiveness of visual monitoring. A similar study, 
including the assessment of both passive and active acoustic 
monitoring, would provide a more appropriate means than the Navy's 
current approach for concluding that the measures are 100 percent 
effective.
    Response: The effectiveness of the HF/M3 sonar system to monitor 
and detect marine mammals has been assessed. Details on this assessment 
and the effectiveness of the HF/M3 system are provided in a technical 
report by Ellison and Stein (2001), the 2001 SURTASS LFA FOEIS/EIS (see 
subchapters 2.3.2.2 and 4.2.7.1 for the HF/M3 sonar testing results), 
as well as Chapter 4, Section 5.4.3 of the 2019 SURTASS LFA FSEIS/
SOEIS. The study qualitatively and quantitatively assessed the HF/M3 
system's ability to detect marine mammals of various sizes with 170 
hours of at-sea testing, including trials off the coast of San Diego 
with trained bottlenose dolphins, as well as several developmental 
tests with artificial targets (which allowed for examination of whether 
these methods potentially miss animals). The results indicate a near 
100 percent probability of detecting marine mammals before they enter 
the LFA mitigation zone. As noted by the commenter, the Navy continues 
to assess the effectiveness of its mitigation measures. The results of 
any new studies will be assessed through the Adaptive Management 
process. NMFS acknowledges the limitations associated with visual and 
passive acoustic monitoring, but together with the near 100 percent 
effectiveness of active acoustic monitoring with the HF/M3 sonar 
system, NMFS has determined that these mitigation monitoring measures 
are highly effective.
    Comment 20: NRDC et al. noted that the proposed mitigation distance 
resulting in sound pressure levels within OBIAs and coastal exclusion 
zones not to exceed 180 dB re 1 [mu]Pa (rms) bears no relation to the 
Navy's behavioral response function, even though the agencies have 
repeatedly identified behavioral disruption as the primary marine 
mammal impact of concern from LFA sonar, or to any qualitative 
assessment of stress response or masking effects. NRDC et al. noted 
that it roughly reflects the Navy's threshold for the onset of auditory 
injury per NMFS guidance. NRDC et al. stated that the 180 dB threshold 
fails to meaningfully protect marine mammals from the behavioral 
impacts that the agencies have repeatedly characterized as the impacts 
of primary concern. They noted that according to prior Navy analysis, 
the 175-180 dB (rms) annulus has an average ``take'' risk of 91.5 
percent, the 170-175 dB (rms) annulus a take risk of 80.5 percent, the 
165-170 dB (rms) annulus a risk of 61.5 percent, the 160-165 dB annulus 
a risk of 38.5 percent (rms), the 155-160 dB annulus a risk of 18 
percent, and the 150-155 dB annulus a risk on the order of 8-9 percent 
(see 2007 SEIS at 4-74). They stated that given the greater area 
subsumed within the lower-decibel annuluses, the number of takes 
occurring within even the 150 dB annulus can be high, despite the lower 
relative risk. NRDC et al. stated that the geographic sound field 
operational constraints designed to eliminate LFA exposures out to at 
least 150 dB (rms) are likely to be practicable for most, if not all, 
OBIAs, as the Navy already avoids dive sites out to 145 dB (rms) (DSEIS 
at 5-5), nominally requiring a greater mitigation distance than a 150 
dB (rms) standoff would entail. They stated that the Navy's broad claim 
of impracticability for any mitigation threshold lower than 180 dB 
exemplifies the non-rigorous rationalizing that the court in 
Conservation Council found unconvincing and unsupportable under the 
MMPA (See 97 F.Supp.3d at 1229-31). NRDC et al. stated that NMFS' 
``practicability criterion'' requires a site-specific discussion, with 
the Navy, of any OBIA that the Navy initially determines to be 
impracticable, to see if a modification of the OBIA can address the 
issue. They recommended that the Navy and NMFS presumptively adopt a 
150 dB (rms) mitigation distance from each OBIA, except where 
geographically specific, clearly stated operational needs make such a 
distance impracticable, in which case it should adopt the largest 
practicable distance, to be determined on a case-by-case basis 
according to the procedure set forth in the ``practicability 
criterion.''
    Response: After the development of NMFS' 2018 Acoustic Technical 
Guidance, NMFS and the Navy reevaluated the use of 180 dB re: 1 [mu]Pa 
rms as the basis for the LFA mitigation zone and concluded that 180 dB 
would be retained as the mitigation basis (see the Mitigation section 
of this final rule and Chapter 5, Section 5.2 of the 2019

[[Page 40147]]

SURTASS LFA FSEIS/SOEIS for details on this reevaluation). However, in 
consideration of updated PTS and TTS thresholds, the 180 dB threshold 
for the OBIA and the coastal exclusion zone boundaries is expected to 
preclude not only PTS at the outer perimeter of these areas, but also 
likely some instances of TTS and more severe forms of Level B 
harassment by behavioral disruption. Moreover, the 180 dB threshold 
applies at a distance 1 km from OBIA boundaries, further reducing 
exposure levels at the OBIA perimeters to approximately 174 dB. In 
addition, the likelihood and severity of behavioral harassment is 
further reduced within these important areas as maximum received levels 
in these areas are even lower the farther an animal is from the 
perimeter and the farther the vessel is from the edge. In other words, 
while an individual in the coastal exclusion zone might be exposed to 
levels as high as 180 dB (174 dB if in an OBIA, given the 1 km buffer) 
briefly if animal is at the edge and a SURTASS LFA vessel has 
approached at the closest allowable distance from the edge--the 
majority of individuals within the area will always be exposed to 
levels increasingly lower than that (the farther they are from the 
edge), plus the vast majority of the time SURTASS LFA vessels will not 
be right at the edge. Therefore, while this mitigation measure based on 
180 dB will not totally avoid all takes within OBIAs, it will 
meaningfully reduce both the number and severity of takes within these 
important areas significantly by ensuring that the majority of 
individual marine mammals within these areas are exposed to lower 
levels with lower probabilities of being taken, and less severe 
responses if the take occurs.
    Regarding the comments about practicability, NMFS and the Navy have 
thoroughly evaluated the practicability of all of the mitigation 
measures, including the OBIAs and their associated 180-dB zones, and in 
consideration of public comments have added an additional measure to 
further minimize behavioral harassment within OBIAs. Specifically, no 
more than 25 percent of the authorized amount of SURTASS LFA sonar will 
be used for training and testing within 10 nmi (18.5 km) of any single 
OBIA during any year unless it is required for national security, 
permission is obtained from the appropriate designated Command 
authority prior to commencement of the activity, NMFS is notified as 
soon as is practicable, and these sonar hours are reported in annual 
activity reports. This measure ensures that exposures (and thereby 
probability and severity of Level B harassment) to LFA sonar of 
individuals within OBIAs will be even further limited, both in received 
level and time. Specifically, the already protective circumstances 
described for OBIAs above will be in place up until an OBIA has been 
exposed to LFA sonar for 124-148 hours per year; beyond that number of 
hours, the maximum received level an individual may be exposed to (when 
both the animal is at the edge and the vessel at its closest approach) 
would be substantially reduced and, as described above, any marine 
mammals further within the OBIA would be exposed to even lower levels, 
and even lower when the vessel is not right at the edge.
    Further, it is inappropriate to compare the 145-dB zone around dive 
sites to the 180-dB zone around OBIAs, as they have different purposes 
and are subject to different requirements. Whereas the goal of the 145-
dB zone around dive sites is generally to avoid any impacts to human 
divers and is in no way associated with the requirements of the MMPA, 
take of marine mammals is expected and authorized to occur, but as 
required by the MMPA, NMFS and the Navy have ensured that the extensive 
suite of measures required will effect the least practicable adverse 
impact.
    Comment 21: NRDC et al. stated that the criteria NMFS adopted 
[NMFS' Acoustic Technical Guidance], following the Navy, to estimate 
temporary and permanent threshold shift in marine mammals are erroneous 
and non-conservative. They stated that Wright (2015) identified several 
statistical and numerical faults in the Navy's approach, such as 
pseudo-replication and inconsistent treatment of data that tend to bias 
the proposed criteria towards an underestimation of effects. NRDC et 
al. stated that similar and additional issues were raised by a dozen 
scientists during the public comment period on the draft Acoustic 
Technical Guidance held by NMFS and noted that at the root of the 
problem is the agencies' broad extrapolation from a small number of 
individual animals, mostly bottlenose dolphins, without taking account 
of what Racca et al. (2015) have succinctly characterized as a ``non-
linear accumulation of uncertainty.''
    Response: NMFS disagrees with this characterization of the Acoustic 
Technical Guidance and the associated recommendation. The Acoustic 
Technical Guidance is a compilation, interpretation, and synthesis of 
the scientific literature that provides the best scientific information 
regarding the effects of anthropogenic sound on marine mammals' 
hearing. The Technical Guidance was classified as a Highly Influential 
Scientific Assessment and, as such, underwent three independent peer 
reviews, at three different stages in its development, including a 
follow-up to one of the peer reviews, prior to its dissemination by 
NMFS. In addition, there were three separate public comment periods, 
during which time we received and responded to similar comments on the 
guidance (81 FR 51694; August 4, 2016), which we cross-reference here, 
and more recent public and interagency review under Executive Order 
13795. This review process was scientifically rigorous and ensured that 
the Guidance represents the best scientific data available. 
Furthermore, the recent peer-reviewed updated marine mammal noise 
exposure criteria by Southall et al. (2019) provide identical PTS and 
TTS thresholds to those provided in NMFS' Acoustic Technical Guidance.
    NMFS disagrees with any suggestion that the use of the Acoustic 
Technical Guidance provides erroneous results. The use of the 180-dB 
rms threshold to identify where PTS would occur is plainly outdated, as 
the best available science indicates that rms SPL is not an appropriate 
metric by which to gauge potential auditory injury (whereas the 
scientific debate regarding thresholds for Level B harassment by 
behavioral disruption is not about the proper metric but rather the 
proper level or levels and how these may vary in different contexts).
    Regarding the suggestion that the thresholds are non-conservative, 
multiple studies from humans, terrestrial mammals, and marine mammals 
have demonstrated less TTS from intermittent exposures compared to 
continuous exposures with the same total energy because hearing is 
known to experience some recovery in between noise exposures, which 
means that the effects of intermittent noise sources such as tactical 
sonars are likely overestimated. Marine mammal TTS data have also shown 
that, for two exposures with equal energy, the longer duration exposure 
tends to produce a larger amount of TTS. Most marine mammal TTS data 
have been obtained using exposure durations of tens of seconds up to an 
hour, much longer than the durations of many tactical sources (much 
less the continuous time that a marine mammal in the field would be 
exposed consecutively to those levels), further suggesting that the use 
of these TTS data are likely to overestimate the effects of sonars with 
shorter duration signals.
    Regarding the suggestion of pseudo-replication and erroneous 
models, since

[[Page 40148]]

marine mammal hearing and noise-induced hearing loss data are limited, 
both in the number of species and in the number of individuals 
available, attempts to minimize pseudo-replication would further reduce 
these already limited data sets. Specifically, with marine mammal 
behavioral temporary threshold shift studies, behaviorally derived data 
are only available for two mid-frequency cetacean species (bottlenose 
dolphin, beluga) and two phocids (in-water) pinniped species (harbor 
seal and northern elephant seal), with otariid (in-water) pinnipeds and 
high-frequency cetaceans only having behaviorally-derived data from one 
species. Arguments from Wright (2015) regarding pseudo-replication 
within the TTS data are therefore largely irrelevant in a practical 
sense because there are so few data points. Multiple data points were 
not included for the same individual at a single frequency. If multiple 
data points existed at one frequency, the lowest TTS onset was always 
used. There is only a single frequency where TTS onset data exist for 
two individuals of the same species: 3 kHz for dolphins. Their TTS 
(unweighted) onset values were 193 and 194 dB re 1 [mu]Pa\2\s. Thus, 
NMFS believes that the current approach makes the best use of the given 
data. Appropriate means of reducing pseudo-replication may be 
considered in the future, if more data become available. Many other 
comments from Wright (2015) and the comments from Racca et al. (2015b) 
appear to be erroneously based on the idea that the shapes of the 
auditory weighting functions and TTS/PTS exposure thresholds are 
directly related to the audiograms; i.e., that changes to the composite 
audiograms would directly influence the TTS/PTS exposure functions 
(e.g., Wright (2015) describes weighting functions as ``effectively the 
mirror image of an audiogram'' (p. 2) and states, ``The underlying goal 
was to estimate how much a sound level needs to be above hearing 
threshold to induce TTS.'' (p. 3)). Both statements are incorrect and 
suggest a fundamental misunderstanding of the criteria/threshold 
derivation. This would require a constant (frequency-independent) 
relationship between hearing threshold and TTS onset that is not 
reflected in the actual marine mammal TTS data. Attempts to create a 
``cautionary'' outcome by artificially lowering the composite audiogram 
thresholds would not necessarily result in lower TTS/PTS exposure 
levels, since the exposure functions are to a large extent based on 
applying mathematical functions to fit the existing TTS data.
    Comment 22: NRDC et al. stated the proposed rule gives little 
consideration to expanding the LFA coastal exclusion zone, assuming, 
based on its analysis in prior environmental reviews, that its standoff 
distance should remain 12 nmi from shore. The commenters stated that 
this reliance on prior analyses is not supportable.
    Response: As described in the Mitigation section, the Navy's 2007 
SURTASS LFA FSEIS/SOEIS evaluated increasing the coastal standoff 
distance up to 46 km (25 nmi). Based on a six-step analysis process, 
its analysis showed that increasing the coastal standoff range would 
decrease exposure to higher received levels for concentrations of 
marine animals closest to shore, but would do so at the expense of 
increasing exposure levels for shelf break and pelagic species. This 
result is due to the reduced overlap of the exposure area with land 
leading to an increase in exposure area as the sound source moves 
farther offshore. There have been no changes to the best available 
scientific information or other indications that the coastal standoff 
distance should be increased since this analysis; therefore, there is 
no change in this mitigation measure from previous rulemakings. 
Nonetheless, it is also erroneous to say that the new rule gives no 
consideration to further extending the coastal exclusion, given the 
extensive analysis of the White Paper (see Mitigation section and 
response to Comment 23 immediately below), which included a 
recommendation for a larger coastal exclusion. As noted in the 2012 
final rule (77 FR 50290; August 20, 2012), over 80 percent of the 
existing and potential marine protected areas reviewed were within 12 
nmi from a coastline, indicating the effectiveness of the coastal 
standoff as one of the primary mitigation measures for reducing 
potential impacts to marine mammals. OBIAs expand upon this protection 
by avoiding or minimizing impacts in areas beyond the coastal standoff 
distance where marine mammals are known to engage in specific behaviors 
that may lead to more severe impacts if interrupted; known to 
congregate in higher densities; and/or known to have a limited range 
and small abundance that creates more vulnerability for the stock as a 
whole. These criteria are important when determining whether mitigation 
would be likely to reduce the probability of effects to individuals 
that would translate to minimization of impacts at the population level 
under the LPAI standard.
    Comment 23: NRDC et al. noted that they have called on the Navy and 
NMFS to adopt a more expansive, more biologically meaningful coastal 
exclusion, particularly one that protects the continental shelf and 
slope with a standoff from the shelf break. They noted that NMFS' own 
subject-matter experts, in the White Paper, recommend that, absent 
specific data to the contrary, ``all continental shelf waters and 
waters 100 km of the continental slope should be designated as 
biologically important habitat for marine mammals.'' They recommended 
that NMFS, in consultation with the Navy, should consider alternative 
coastal exclusion areas.
    Response: NMFS carefully considered the White Paper's 
recommendations and we present an evaluation of the White Paper's 
recommendation to restrict LFA sonar transmissions from all continental 
shelf waters and waters 100 km seaward of continental slope in the 
White Paper Specific Recommendations subsection of the Mitigation 
section. As discussed in this section, given the other mitigation 
measures we are requiring, takes of marine mammals would be limited to 
Level B harassment in the less severe range of behavioral reactions and 
some TTS, as described above. Consequently, the only additional 
anticipated value to restricting SURTASS LFA sonar activities in 
continental shelf waters and waters 100 km seaward of continental slope 
would be some potential, though not certain or significant, reduction 
in the number of less severe behavioral reactions in those areas. In 
general, not all behavioral responses rise to the level of a take and 
not all harassment takes result in fitness consequences to individuals 
that have the potential to translate to population consequences to the 
species or stock. Given the anticipated impacts of SURTASS LFA sonar, 
there is little to no likelihood that the impacts of the anticipated 
takes would accrue in a manner that would impact a species or stock 
even in the absence of any additional mitigation. Considered with the 
uncertain potential of this proposed recommendation to provide 
meaningful incremental reduction of risk or severity of impacts to 
individual marine mammals, NMFS concludes that this recommendation 
would not reasonably be expected to provide a reduction in the 
probability or degree of effects on any marine mammal species or 
stocks. Moreover, NMFS discusses why the measure would not be 
practicable for the Navy to implement. NMFS acknowledges that while 
these measures could potentially reduce the numbers of

[[Page 40149]]

takes of some individual marine mammals within a limited number of 
species, or could add some small degree of protection to preferred 
habitat or feeding behaviors in certain circumstances, this limited and 
uncertain benefit did not justify adopting the White Paper's 
recommendations considering the existing mitigation measures already 
implemented by the Navy and the high degree of impracticality for Navy 
implementation.

Offshore Biologically Important Areas (OBIAs)

OBIA Criteria/Evaluation Process

    Comment 24: The Commission noted that a lack of data or 
insufficient data regarding marine mammal presence and abundance is not 
an adequate basis for failing to adopt precautionary measures, 
especially when such data are not available for most of the world's 
oceans. The Commission noted it made this point in its 2011 letter on a 
previous DSEIS and the U.S. Court of Appeals for the Ninth Circuit 
remanded the SURTASS LFA sonar case on that basis. The Commission 
stated that the Ninth Circuit indicated that NMFS and the Navy should 
have considered whether a precautionary approach would give more 
protection to marine mammals, and then whether that protection would 
impede military training to a degree that makes such mitigation 
impracticable. The Commission stated that it appears that NMFS is 
failing to take a sufficiently precautionary approach, particularly 
with respect to the Pacific Remote Island MNM.
    Response: We acknowledge that the Ninth Circuit opinion stated that 
NMFS ``should have considered whether `the precautionary approach' 
would give more protection to marine mammals, and then whether that 
protection would impede military training to a degree making that 
mitigation not practicable.'' Pritzker, 828 F.3d at 1138. The Court 
went on to fault NMFS for not considering the White Paper's 
recommendations. Taken in the context of the Court's full discussion, 
however, we read the Ninth Circuit's use of the term ``the 
precautionary approach'' as specifically referring to the 
recommendations in the White Paper for designating OBIAs in ``data-
poor'' regions of the ocean (described therein as a precautionary 
approach for designating OBIAs), rather than a broader mandate to adopt 
a ``precautionary approach'' in carrying out the requirements of the 
statute.
    In response to the Ninth Circuit's opinion and in the context of 
the LPAI standard, for this rulemaking NMFS directly considered the 
White Paper recommendations (see discussion of the White Paper 
recommendation in the Mitigation section). We considered the factors as 
instructed by the Court, although we ultimately did not adopt the White 
Paper's recommendations.
    NMFS' interpretation of the Ninth Circuit's opinion is based on the 
fact that neither the MMPA nor NMFS' implementing regulations include 
references to, or requirements for, the precautionary approach, nor is 
there a clear, agreed-upon description of what the precautionary 
approach is or would entail in the context of the MMPA or any specific 
activity. Nevertheless, the MMPA by nature is inherently protective, 
including the requirement to mitigate to the lowest level practicable 
(``least'' practicable adverse impacts, or ``LPAI,'' on species or 
stocks and their habitat).\1\ This requires that NMFS assess measures 
in light of the LPAI standard. To fulfill that requirement, NMFS 
considers all measures that we are reasonably aware of (e.g., from 
recommendations or review of data) that have the potential to reduce 
impacts on marine mammal species or stocks, their habitat, or 
subsistence uses of those stocks, regardless of whether those measures 
are characterized as ``precautionary'' or address ``data-poor'' areas. 
Through the LPAI standard, NMFS considers ``precautionary'' 
recommendations such as those contained in the White Paper. As 
discussed below, the OBIA process specifically allows for consideration 
of areas that could be characterized as relatively ``data-poor'' and we 
also considered measures that provide for mitigation in data-poor areas 
under the LPAI standard (independent of the OBIA process, i.e., the 
White Paper). In short, we believe the requirements of section 
101(a)(5)(A), including the LPAI standard, have been satisfied.
---------------------------------------------------------------------------

    \1\ We are aware of statements we made in the preamble for our 
2001 incidental take regulations for the Navy's ship shock tests (66 
FR 22450, 22453 (May 4, 2001)), in which we evaluated the impact of 
underwater detonations that propagate shock waves through a ship's 
hull under deliberate and controlled conditions to simulate near 
misses from underwater explosions similar to those encountered in 
combat. In that case, NMFS was authorizing up to four mortalities 
and six non-serious injuries of various species. During that 
rulemaking we received a public comment stating that in the absence 
of adequate data, NMFS and the Navy should apply the precautionary 
principle, ``the fundamental elements of the principle being: the 
existence of some indication of threat of harm; the harm is serious 
or irreversible; scientific uncertainty as to the nature or severity 
of the outcome; and an obligation on decision-makers.'' Our response 
said:
    The MMPA prohibits the taking of marine mammals unless exempted 
or permitted. Taking means to harass, hunt, capture, or kill, or 
attempt to harass, hunt, capture, or kill any marine mammal. 
Therefore, NMFS believes that the precautionary principle is already 
at the core of the MMPA. However, because the MMPA authorizes the 
taking of marine mammals under section 101(a)(5), provided certain 
conditions and requirements are met, NMFS must prudently apply the 
Precautionary Principle through careful analysis of impacts and 
implementation of measures that will reduce impacts to marine 
mammals to the lowest level practicable. As described in this 
document, NMFS believes that it and the Navy have applied the 
Precautionary Principle to the greatest extent possible for this 
action through an extensive aerial monitoring and mitigation program 
that will protect marine mammals to the greatest extent practicable. 
The mitigation and monitoring program are discussed later in this 
document. In addition, NMFS and the Navy have applied the 
precautionary principle by having the decision-making process in the 
public forum through NEPA and notice and comment rulemaking.
    Taken as a whole, we do not view that response as inconsistent 
with our current position. We agree here that the MMPA is inherently 
protective. As for the mitigation imposed for the ship shock trials, 
we said we conducted a careful analysis of impacts and 
implementation of measures that will reduce impacts to marine 
mammals to the lowest level practicable. This consisted of an 
extensive aerial monitoring program, delaying detonations, and 
requirements for good visibility and daylight. Those specific 
measures would be appropriate under the LPAI approach we set forth 
in this rule assuming similar circumstances. The risks to individual 
marine mammals from the ship shock tests were potentially 
irreversible in terms of acute impacts to fitness in light of the 
nature of the specified activity, and the mitigation and monitoring 
measures were deemed appropriate to achieve the LPAI standard.
---------------------------------------------------------------------------

    The Ninth Circuit's Pritzker decision faulted NMFS for not 
considering the White Paper mitigation recommendations for ``data-poor 
areas'' against the OBIA standards NMFS had set for the 2012 rule. We 
do not read the opinion as holding that the MMPA compelled a change in 
the criteria and process for evaluating OBIAs. Again, NMFS addressed 
the Court's decision by separately and independently evaluating the 
White Paper's recommendations for benefits to the affected species or 
stocks and practicability, without regard to the OBIA criteria. Using 
the best available information, NMFS considered the recommendations in 
the White Paper under our interpretation of the LPAI standard and 
determined the measures (as well as smaller buffer distances) were not 
warranted, as described in those sections of this rule.
    In reaching the conclusion that NMFS' record for the 2012 rule did 
not establish the agency had satisfied the LPAI standard, the Court 
determined that NMFS failed to consider an important aspect of the 
problem, ``namely the underprotection that accompanies making 
conclusive data an indispensable component of OBIA designation,'' and 
that this ``systematic underprotection of marine mammals''

[[Page 40150]]

cannot be consistent with the requirement that mitigation measures 
result in the ``least practicable adverse impact'' on marine mammals.'' 
Pritzker, 828 F.3d 1125 at 1140. While we have corrected the identified 
deficiency by evaluating the White Paper measures independent of the 
OBIA criteria, we disagree with the suggestion that the prescribed 
mitigation is systematically underprotective.
    We emphasize that NMFS' (and the Navy's) informational standards 
for OBIAs and other mitigation measures, while data-driven, do not 
require scientific certainty or conclusive data. This is illustrated by 
the fact that the OBIA criteria and factors allow for consideration of 
a variety of information sources, including historic whaling data, 
stranding data, sightings information, and regional expertise, to name 
a few examples of the data considered. As more detailed in Appendix C 
of the 2019 SURTASS LFA FSEIS/SOEIS, supporting documents that are 
considered include peer-reviewed articles; scientific committee 
reports; cruise reports or transects; personal communications or 
unpublished reports; dissertations or theses; books, government 
reports, or NGO reports; and notes, abstracts, and conference 
proceedings. In fact, NMFS has designated OBIAs for areas based on 
these types of information sources (whaling data, stranding data, 
unpublished reports, etc.). For example, the evidence supporting the 
designation of the Southern Bali OBIA (designated in this rule) is 
largely from an unpublished report of line-transect surveys and the 
National Marine Mammal Stranding Network of Indonesia.
    Thus, we disagree that we are failing to take a sufficiently 
precautionary approach. The Pacific Remote Islands Marine National 
Monument (Wake/Johnson/Palmyra atolls and Kingman Reef Units, which are 
located in the SURTASS LFA Study Area) was on the OBIA Watchlist and 
was considered as a candidate OBIA. NMFS and the Navy reviewed all 
available data and no specific important biological behaviors of marine 
mammals have been characterized in these waters. As such, this marine 
area did not meet the biological criteria required for designation of 
an OBIA and was not further considered currently as an OBIA.
    Comment 25: The Commission stated its concern that although NMFS 
has identified potential OBIAs it might include in the final rule, it 
has neither specified which ones it actually is proposing to include 
nor provided any assessment of whether it believes including specific 
areas that meet the designation criteria would be practicable. Rather, 
NMFS has only requested public comment on whether any of the potential 
areas satisfy the OBIA criteria, after which time the Navy and NMFS 
would, apparently without any additional public input, evaluate the 
practicability of those measures to avoid or reduce impacts in those 
areas. The Commission stated that NMFS' approach effectively undermines 
the ability of the Commission and others to provide informed comments 
on that portion of the proposed rule.
    Response: In the Federal Register notice of the proposed rule, we 
described the process NMFS and the Navy used to identify and evaluate 
potential OBIAs and presented 25 areas considered for potential 
designation as new OBIAs for this rulemaking. We presented the draft 
analysis for these potential OBIAs using the identified OBIA criteria 
and factors in a document entitled Potential Marine Mammal OBIAs for 
SURTASS LFA Sonar; Marine Areas Under Consideration. Through the 
proposed rule, the public had the opportunity to comment on the OBIA 
analysis and designation process (including practicability) and 
potential OBIAs (including recommending additional OBIAs). As noted in 
response to Comment 15, we disagree that the ability to provide 
informed comments was undermined, given the public was provided a 
discrete, manageable list of potential OBIAs supported by our 
preliminary analysis, and that NMFS was accepting and addressing input 
regarding biological qualifications and practicability. Further, as 
always, NMFS will also consider entirely new recommendations for OBIAs 
through the adaptive management process, and will do so utilizing the 
process and types of information described in the proposed rule.
    Comment 26: NRDC et al. recommended that NMFS reconsider the 
guidelines for capturing biologically important marine mammal habitat 
in data-poor areas that its subject-matter experts provided during the 
last LFA authorization cycle (in the White Paper) and that were 
addressed by the Ninth Circuit. NRDC et al. stated that information on 
cetacean distribution and habitat use demonstrate that the White Paper 
guidelines (as described in their additional comments on OBIAs) hold 
true in almost every case, with important marine mammal habitat areas 
occurring along continental shelf and shelf edge waters (e.g., the 
multi-species migratory route off western Australia), around seamounts 
and island systems (e.g., the humpback whale feeding area supported by 
the bathymetric and oceanographic complexity of the Commander Islands), 
and in other areas of high productivity (e.g., the multi-species 
feeding area supported by the North Pacific Transition Zone). NRDC et 
al. recommend that NMFS reconsider the White Paper guidelines.
    Response: See response to Comment 23. NMFS carefully considered the 
White Paper's recommendations and we present an evaluation of the White 
Paper's recommendations in the White Paper Specific Recommendations 
subsection of the Mitigation section.
    Comment 27: NRDC et al. recommended that NMFS consider alternative 
habitat models and (particularly in the Northwest Pacific) additional 
line-transect data for identifying areas of biological importance. NRDC 
et al. stated that it is prudent for NMFS to consider alternative 
modeling approaches capable of accounting for non-standardized 
collection of survey data and opportunistic sightings such as those 
presented in Corkeron et al. (2011), Lambert et al. (2014), and 
Mannocci et al. (2015). NRDC et al. noted that the IWC-POWER large-area 
transect surveys conducted by Japan over the last decade provide a 
basis for empirically grounded modeling and identification of high-
density habitat for most of the Navy's Northwest Pacific operations 
area. NRDC et al. note that NMFS now has the data needed to conduct a 
data-based analysis in this region at least, satisfying its own 
criteria for OBIA identification. NRDC et al. recommended that NMFS 
should consult the same subject-matter experts it drew upon during the 
last authorization cycle, who are the agency's experts in marine mammal 
habitat modeling in the North Pacific.
    Response: NMFS and the Navy are aware of the active area of 
research in developing habitat-based models that extrapolate cetacean 
densities beyond surveyed regions. For example, the Navy and NMFS were 
reviewers of and used the results of Mannocci et al. (2017) for the 
U.S. Navy's Atlantic Fleet Training and Testing area NEPA analyses and 
MMPA rulemaking. As previously noted in the response to Comment 3, it 
is possible that the sighting results from the IWC-POWER cruises could 
be used to extrapolate density and abundance estimates throughout the 
North Pacific in the future, using the methods developed by Mannocci et 
al. (2015) that were applied to extrapolate density estimates in the 
North Atlantic (Mannocci et al., 2017). Cruise reports through 2017 are

[[Page 40151]]

available online, with cruises continuing for another few years. When 
additional results are available, NMFS and the Navy will consider use 
of these methods to extrapolate density and abundance estimates that 
could inform identification of biologically important areas through the 
Adaptive Management process. Lambert et al. (2014) used the simulated 
distribution of micronekton from the Spatial Ecosystem And Population 
Dynamics Model (SEAPODYM) to predict the habitat of three cetacean 
guilds in tropical waters. While their results provide some interesting 
insights into the use of predicted prey maps in cetacean distribution 
models, they are best used to prioritize future research areas. 
Corkeron et al. (2011) developed statistical methods for using 
spatially autocorrelated sighting results to identify the Dhofar coast 
of Oman as an important region for the Arabian Sea DPS of humpback 
whales. However, the Dhofar coast of Oman is outside of the SURTASS LFA 
sonar Study Area and Corkeren et al. (2011) state ``Although it is 
theoretically possible for us to project model predictions into other 
areas, we consider this inadvisable, as our basic design was not to 
make inference about the distribution of humpback whales along the 
entire Oman coast.'' Therefore, though its statistical models could be 
applied to sightings data within the SURTASS LFA Study Area, the 
humpback whale results are not applicable. NMFS and the Navy will 
continue to consider, discuss and examine the utility of these models 
for identifying important areas for marine mammals in the SURTASS LFA 
sonar Study Area.
    Comment 28: NRDC et al. recommended that NMFS and the Navy 
communicate directly with researchers in the Indian Ocean and Asia to 
identify potential areas of biological importance, including areas with 
high cetacean abundance. NRDC et al. included a list of contacts in 
their comment letter (Appendix).
    Response: NMFS and the Navy acknowledge the importance of regional 
input to identify and gather data for areas of biological importance to 
marine mammals for which information may not be available in published 
literature. To obtain the best available data for each potential OBIA, 
NMFS and the Navy conducted a deep and comprehensive literature review. 
As described in the response to Comment 24 the Navy and NMFS considered 
a variety of information sources when evaluating the potential of an 
area as an OBIA (detailed in Appendix C of the 2019 SURTASS LFA FSEIS/
SOEIS), including information gathered from regional experts. NMFS and 
the Navy contacted regional experts when available information was not 
sufficient to determine whether an area met the OBIA criteria and 
factors. In these cases NMFS and the Navy contacted regional 
researchers known to be conducting research or surveys in the area. The 
Navy and NMFS contacted marine mammal researchers in the Marianas and 
Guam region to request copies of their marine mammal sighting data to 
gain an understanding about the areas already identified via survey 
effort where marine mammals may be aggregating and conducting 
biologically important behaviors. We also provided the opportunity for 
regional researchers to comment on the potential OBIAs and the OBIA 
analysis, and to suggest additional OBIAs for consideration through the 
public comment process on the proposed rule and the 2018 SURTASS LFA 
DSEIS/SOEIS. In addition to using information gathered from regional 
experts and presented in reports with regional authors (for example, 
through the IMMA and EBSA designation process), as noted in response to 
Comment 24 and detailed in Appendix C of the 2019 SURTASS LFA FSEIS/
SOEIS, we also used a variety of supporting documents including peer-
reviewed articles; scientific committee reports; cruise reports or 
transects; personal communications or unpublished reports; 
dissertations or theses; books, government reports, or NGO reports; and 
notes, abstracts, and conference proceedings. At any rate, NMFS and the 
Navy have considered the best available science in the development of 
this SURTASS LFA sonar final rule. Given limited agency resources, the 
limited likely value added beyond our already extensive research, and 
the fact that there is no requirement that the agency communicate 
directly with all experts in a particular topic, we have not contacted 
all of the individuals recommended by NRDC.
    In a related effort, NMFS and the Navy have obligated funding to 
convene a Working Group/Expert Elicitation effort (beginning in 2020) 
to update existing Biologically Important Areas and identify new areas 
outside of the U.S. Exclusive Economic Zone (EEZ). As applicable, the 
results of this effort would be considered through the adaptive 
management provision of the rule.
    Comment 29: NRDC et al. expressed concern that NMFS' selection 
criteria for OBIAs maintain an evidentiary requirement that exceeds the 
information available for most of the LFA operations area. See, e.g., 
84 FR at 7234 (noting that ``best source'' of data demonstrating high 
marine mammal densities ``is publicly-available, direct measurements 
from survey data''). NRDC et al. stated that while NMFS' criteria do 
allow for use of ``other available data or information,'' they do so 
only if ``those data and information, either alone or in combination 
with limited direct data, are sufficient to establish that at least one 
of the biological criteria are present,'' and that it remains unclear 
from this description what evidentiary standard will apply to the 
consideration of OBIAs where direct data are not available.
    Response: NMFS does not require ``conclusive data'' \2\ for 
imposing conservation and management measures for SURTASS LFA sonar, 
including--though not only--in the case of OBIAs (see response to 
Comment 24). As another example of the incorporation of data poor areas 
in mitigation measures, the coastal standoff zone uniformly applies not 
only in areas with supporting data about marine mammals (80 percent of 
the areas initially identified for OBIA consideration in 2012 were 
within the 12 nmi (22 km) coastal standoff) but also in areas that 
could be fairly characterized as data poor. In addition, shutdown 
protocols will be in effect wherever SURTASS LFA sonar activities 
occur, including in areas where data are limited.
---------------------------------------------------------------------------

    \2\ NRDC v. Pritzker, 828 F.3d 1125, 1140 (9th Cir. 2016).
---------------------------------------------------------------------------

    Comment 30: NRDC et al. stated that as it did during the most 
recent authorization cycle, NMFS proposes to exclude from OBIA 
consideration all marine mammals that do not exhibit low-frequency 
specialization, excepting sperm whales and elephant seals, and that 
this position remains non-precautionary and inappropriate. They state 
that the Navy did not include odontocetes in the LFA SRP which it 
continues to take as the exclusive data source for estimating impacts 
from the LFA system, notwithstanding that study's age and limitations. 
NRDC et al. noted that recent meta analyses of the ocean noise 
literature indicates that, taken as a whole, the odontocetes are 
behaviorally reactive to predominantly low-frequency sources of noise, 
in ways that are consistent with a higher potential for effects on 
vital rates, at exposure levels that would put them well outside the 
LFA shutdown zone (Gomez et al., 2016; Bowles et al., 1994).
    NRDC et al. goes on to state that literature has also demonstrated 
that some species, such as harbor porpoises and beaked whales, are 
particularly

[[Page 40152]]

sensitive to a diversity of anthropogenic sounds, including sounds of 
predominantly low frequency; and physiological research on finless 
porpoise indicates that a heightened sensitivity to lower-frequency 
sound may be conserved across porpoise species (Liu, 1985; Li et al., 
2008). They indicated that several studies have reported harbor 
porpoise behavioral responses to pile driving sounds (Tougaard et al., 
2009; Bailey et al., 2010; Brandt et al., 2011; Dahne et al., 2013; 
Parsons, 2017) and beaked whale behavioral responses to commercial 
shipping sounds and European LFAS systems (between 1 and 2 kHz) 
(Aguilar de Soto et al., 2006; Pirotta et al., 2012; Miller et al., 
2015; Sivle et al., 2015) and that some of these responses occurred at 
distances beyond 20 km (e.g., beyond the 1 km safety zone in proposed 
mitigation). NRDC et al. stated that according to a recent paper on the 
vulnerability of range-limited populations to acoustic impacts, failure 
to consider the effects of both noise exposure and displacement of 
Cuvier's beaked whales from their habitat in this region ``could lead 
to more severe biological consequences than `Level B Harassment''' 
(Forney et al., 2017). NRDC et al. state it is ``improper to exclude 
these acoustically sensitive species from OBIA mitigation,'' and that 
the Navy and NMFS must take a precautionary approach to harbor 
porpoises and beaked whales, both in analyzing impacts and in 
considering habitat-based mitigation measures.
    Response: One of the factors that the Navy and NMFS consider in the 
designation of OBIAs, established in the 2012 FSEIS/SOEIS (DoN, 2012) 
and carried forward in the current OBIA assessment process, is that the 
OBIA protective measures pertain to those species most likely to be 
affected by exposure to LFA sonar transmissions, namely LF sensitive 
species such as baleen whales. Thus, the primary focus of the OBIA 
mitigation measure is on LF hearing specialist species. However, as 
noted in the proposed rule, OBIAs have been designated for non-LF 
hearing specialists, such as elephant seals and sperm whales, since the 
available hearing data for these species indicate an increased 
sensitivity to LF sound (compared to most odontocetes and pinnipeds). 
Therefore, contrary to the comment's assertion, NMFS did not propose to 
exclude from OBIA consideration all marine mammals that do not exhibit 
low-frequency specialization. The very fact that we acknowledged that 
OBIAs could be appropriate for sperm whales and elephant seals negates 
that assertion, and nothing in the proposed rule suggested that NMFS 
would not consider other species with increased sensitivity to LF 
sound, if data indicate that it is appropriate. As described in this 
rule, the hearing sensitivity of other taxa (MF and HF cetaceans) is 
such that their sensitivity to the LFA signal is reduced by 40 to 50 
dB, meaning that source has to be much louder for the animal to hear 
it, and therefore to potentially be behaviorally harassed by it. The 
Navy will implement a near-100 percent-effective mitigation measure for 
minimizing impacts when marine mammals are in close proximity to the 
LFA sonar source (passive and active acoustic and visual detection and 
shutdown), and it also restricts transmissions within the coastal 
standoff range, which encompasses the majority of biologically 
important habitats.
    NMFS and the Navy are aware of the publications discussed by NRDC 
et al. NMFS and the Navy have considered all available data on 
potential impacts to marine mammal species and stocks in their 
analyses, not just the SURTASS LFA sonar SRP. Very few studies (many 
are described by the commenters) have examined odontocete behavioral 
responses to LF sounds. Those that have been conducted largely focus on 
sounds that include both the frequencies produced by LFA sonar (100-500 
Hz) and also higher frequencies (greater than 500 Hz), or LFA sonar 
sounds at higher frequencies than proposed by the Navy (e.g., European 
LFA sonar between 1 and 2 kHz). For example, the sounds produced by 
pile driving, seismic surveys, and vessel movement are broadband, low-
frequency sounds (i.e., containing frequencies greater than 500 Hz), 
and pile driving and seismic survey sounds are more impulsive in nature 
than LFA sonar. Further, some of the responses documented in the 
studies cited are lower level behavioral responses that would not 
necessarily rise to the level of MMPA harassment. It is true that the 
quantitative estimates of takes for all marine mammals are derived from 
the LFA risk continuum, which is based on the behavioral responses of 
LF hearing specialists (baleen whales) collected with an actual SURTASS 
LFA sonar source. As such, these data are realistic contextually and 
remain the best available for quantifying the response of LF-sensitive 
marine mammals to the SURTASS LFA sonar source (see also response to 
Comment 9). Because the LFA risk continuum was developed based on the 
responses of marine mammal species with the most sensitive LF hearing, 
the LFA risk continuum is conservative in that it is anticipated to 
overestimate the responses of other species that are less sensitive to 
LF sounds.
    Comment 31: NRDC et al. stated that NMFS' 2012 rule required the 
Navy to advance research on the impacts of LFA sonar on beaked whales 
and harbor porpoises, first, by convening an independent Scientific 
Advisory Group to make research and monitoring recommendations and, 
second, by either promulgating a plan of action to implement the 
Advisory Group's recommendations or submitting a written response to 
NMFS explaining why they are infeasible. NRDC et al. requested a copy 
of any Scientific Advisory Group and Executive Oversight Group reports 
and recommendations and asked that they be made available to the 
public.
    Response: The Navy completed an assessment of the validity, need, 
and recommendations for field research and/or laboratory research on 
the potential effects of SURTASS LFA sonar on beaked whales and harbor 
porpoises in a final report submitted to NMFS in July 2017, prior to 
the expiration of the 2012 MMPA rule. One research project was funded 
to study the spatial overlap of SURTASS LFA sonar activities with 
harbor porpoise habitat to bound the potential for impacts. Given the 
larger overlap of SURTASS activities with beaked whale populations (as 
compared to harbor porpoises, which have very little overlap with 
SURTASS activities) and the relative lack of data regarding beaked 
whale responses to LFA sonar, the Navy has agreed to initiate a formal 
feasibility study through the Living Marine Resources program to assess 
the value, practicality, and cost of designing and conducting a 
controlled exposure experiment to measure the effects of LFA sonar on 
beaked whales (as well as other marine mammals--see response to Comment 
10).
    The 2013 Scientific Advisory Group report on beaked whales and 
harbor porpoises can be found at: https://www.surtass-lfa-eis.com/downloads/. While there is no Executive Oversight Group report, the 
Executive Oversight Group recommendations are summarized in the 2017 
report Beaked Whale and Harbor Porpoise Monitoring and Reporting 
Requirements which can also be found at: https://www.surtass-lfa-eis.com/downloads/.
    Comment 32: NRDC et al. recommended that in line with NMFS' intent 
in previous authorizations, that frequency specialization be considered 
as one factor among several in determining the relative importance of a

[[Page 40153]]

potential OBIA. NRDC et al. noted that the agency can then focus their 
practicability analysis for odontocete species on the most biologically 
important habitat. NRDC et al. noted that NMFS should give careful 
analysis to areas of high marine mammal biodiversity, which are also 
likely to be areas of high marine biodiversity--appropriate given the 
increasing evidence of impacts of low-frequency sound on non-marine 
mammal biota, some of which is described in the Proposed Rule, and that 
NMFS should carefully analyze the practicability of protecting areas, 
such as those off the main Hawaiian Islands and around certain Hawaiian 
seamounts (which are important to beaked whales, among other species), 
that are known to contain small, resident odontocete populations.
    Response: As described in response to Comment 30, frequency 
specialization is one factor NMFS and the Navy considered when 
evaluating potential OBIAs. The intent of OBIAs is to protect those 
marine mammal species, such as baleen whales, most likely to hear and 
be affected by LFA sonar transmissions and to provide these marine 
mammals additional protections during periods when they are conducting 
biologically significant activities. However, OBIAs have been evaluated 
and designated to provide additional mitigation protection for non-LF 
hearing specialists, such as elephant seals and sperm whales, since the 
available hearing data for these species indicate an increased 
sensitivity to LF sound (compared to most odontocetes and pinnipeds). 
Regarding the comment about areas of high marine mammal diversity, NMFS 
has evaluated all of the areas recommended by commenters in the context 
of the LPAI standard, including several areas of high marine mammal 
diversity (e.g., Southeast Kamchatka OBIA) and our analysis and 
findings are presented in this rule and the SURTASS LFA FSEIS/SOEIS. 
Specifically, NMFS designated the Main Hawaiian Islands OBIA which, 
although designated for the purposes of further protecting humpback 
whales, will also reduce the exposure of several small resident 
populations of odontocetes to SURTASS LFA sonar. NMFS and the Navy will 
continue to evaluate any new science as part of the Adaptive Management 
process.
    Comment 33: NRDC et al. noted that several marine mammal species 
occurring within the proposed SURTASS LFA study area are considered 
``data deficient'' by the International Union for Conservation of 
Nature (IUCN), due to the eastern Indian Ocean and, to a lesser extent, 
the Northwestern Pacific regions being understudied. They stated that 
Parsons (2016) recently suggested that such species should be assumed 
``threatened,'' as it is likely certain data-deficient species are, in 
fact, ``vulnerable'' or ``endangered,'' given their low sightings rates 
and restricted ranges. NRDC et al. recommended NMFS and the Navy work 
with researchers embedded within these regions to help build our state 
of knowledge on these species and identify potential OBIAs. They stated 
that three species of data-deficient cetaceans are worth particular 
note: Omura's whale (Balaenoptera omurai) and Deraniyagala's beaked 
whale (Mespolodon hotula) and Berardius beaked whale, which have been 
recently described in the northern Pacific Ocean.
    Response: NMFS and the Navy are aware of the active area of 
genetics research used to identify new species. Omura's whales and 
Deraniyagala's beaked whales are considered in the rule and SURTASS LFA 
FSEIS/SOEIS impact analyses using the best available data for those 
taxa. The new Berardius beaked whale splits the black form of Baird's 
beaked whale into a new species distinct from the gray form of the 
Baird's beaked whale, which will retain the scientific name Berardius 
bairdii (Morin et al., 2017). Therefore, although this split into two 
species is not part of the LFA impact analysis, the data on Baird's 
beaked whale encompasses both forms, as has traditionally been 
reported.
    While no hearing data on these new species are available, hearing 
in the Omura's whale is presumed, like other baleen whales, to be 
within the range of 7 Hz to 22 kHz and they have been recorded 
producing sounds from 15 to 50 Hz (Cerchio et al., 2015; Southall et 
al., 2007). Very little is known about the Deraniyagala's beaked whale 
and nothing specifically is known about their hearing sensitivity. They 
are, however, similar to other beaked whales presumed to hear in the 
mid-frequency range from 150 Hz to 160 kHz (NMFS, 2018). While their 
hearing range overlaps partially with the frequency bandwidth of 
SURTASS LFA sonar, it is presumed that their bandwidth of best hearing, 
like other beaked whales, is well above the frequency range of SURTASS 
LFA sonar. The intent of OBIAs is to protect those marine mammal 
species, such as baleen whales, most likely to hear and be affected by 
LFA sonar transmissions and to provide them additional protections 
during periods when they are conducting biologically significant 
activities. Thus, the primary focus of the OBIA mitigation measure is 
on LF hearing specialist species. Based on current information, beaked 
whales are not known to have increased sensitivity to LF sounds; 
therefore, we do not believe added protection afforded by an OBIA 
(i.e., beyond that provided by the LFA sonar mitigation zone, described 
in the Mitigation section) is warranted. As with other marine mammals, 
Navy will re-evaluate if additional data become available that 
demonstrate that these animals are more sensitive to LF sounds.
    The proposal described in the Parsons (2016) opinion paper has not 
been adopted by the IUCN. As stated in the IUCN Red List categories and 
criteria (IUCN, 2012) definition: ``A taxon is Data Deficient when 
there is inadequate information to make a direct, or indirect, 
assessment of its risk of extinction based on its distribution and/or 
population status.'' They go to say a data deficient species may be 
well studied, but appropriate data on abundance and/or distribution are 
lacking, and that ``listing of taxa in this category indicates that 
more information is required and acknowledges the possibility that 
future research will show that threatened classification is 
appropriate.'' To be precautionary they suggest, ``it is important to 
make positive use of whatever data are available.'' As described in 
response to Comment 24, NMFS has compiled and assessed the best 
available science, as required, to support the findings made here and 
does not plan to reach out to additional regional experts.

OBIA Areas

    Comment 34: NRDC et al. noted in their comment regarding the 
designation of OBIAs that as ESA Critical Habitat, Important Marine 
Mammal Areas (IMMAs), and Ecologically or Biologically Significant 
Areas (EBSAs), have all previously been identified through a rigorous 
scientific process, including opportunity for public comment and peer 
review; as such, these areas should be immediately carried forward by 
the Navy for geographic mitigation purposes.
    Response: As noted in the Mitigation section of this final rule, 
the 2019 SURTASS LFA FSEIS/SOEIS, and previous documentation for 
SURTASS LFA sonar, criteria for the designation of OBIAs are specific 
to the purpose of designating OBIAs for SURTASS LFA sonar, which is 
geographic mitigation. The purpose and criteria for designation of ESA 
critical habitat, EBSAs, and IMMAs may inform our consideration of 
areas as potential OBIAs but are not per se coincident with the 
criteria or purpose of OBIAs for SURTASS LFA

[[Page 40154]]

sonar. As such, all marine areas considered as potential OBIAs must be 
evaluated per the criteria developed for SURTASS LFA sonar, including 
the Navy's practicability assessment, regardless of the rigorous 
scientific processes other agencies or organizations may have 
undertaken for their marine area designations.
    Comment 35: NRDC et al. noted that 30 IMMAs were recently 
identified in the Northeast Indian Ocean and South East Asian Seas 
Region (IUCN Marine Mammal Protected Areas Task Force 2019) and should 
be incorporated into NMFS' analysis for its Final Rule. They also noted 
that 55 candidate IMMAs were recently been identified in the Western 
Indian Ocean and Arabian Seas by regional experts and submitted for 
additional independent peer review (IMMA sub-regions ``ii'' and ``vii'' 
fall within the LFA Study Area). They recommended that these new IMMAs 
be immediately taken into consideration by NMFS and the Navy as 
potential OBIAs upon their release.
    Response: As recommended, NMFS and the Navy assessed the 30 IMMAs 
designated in the Northeast Indian Ocean and South East Asian Seas 
Regions. Details of this analysis and which IMMAs met the OBIA 
designation criteria are included in Appendix C of the 2019 SURTASS LFA 
FSEIS/SOEIS. As part of the Adaptive Management process for SURTASS LFA 
sonar, NMFS and the Navy will periodically assess any newly designated 
IMMAs for their suitability as OBIAs for SURTASS LFA sonar.
    Comment 36: NRDC et al. recommended the following for blue whales:
    A. Chagos Archipelago--NMFS should ensure that the waters 
encompassed by the no-take marine protected area are included in a 
year-round OBIA to protect important habitat for blue whales as well as 
other cetacean species including sperm whales.
    Response: The BIOT-Chagos Islands Marine Protected Area (MPA) was 
an area on the OBIA Watchlist because when last assessed by NMFS and 
the Navy, sufficient data were not available to determine if marine 
mammals were present and conducting biologically important behaviors in 
the area. The BIOT-Chagos Islands MPA was re-evaluated to determine if 
more data have become available; however, there continues to be limited 
data describing the presence of marine mammals in the MPA, and even 
less data on whether marine mammals are conducting biologically 
important behaviors. Accordingly, the BIOT-Chagos Islands MPA will 
remain on the OBIA Watchlist and NMFS and the Navy will evaluate the 
area as a potential OBIA through the Adaptive Management Process if new 
information becomes available.
    B. Waters around Sri Lanka--NMFS should advance the following areas 
for year-round blue-whale mitigation areas: (i) ``Southern Coastal/
Offshore Waters between Galle and Yala National Park,'' an area largely 
overlapping with OBIA Offshore Sri Lanka but which affords year-round 
protection to the submarine canyons that support high numbers of blue 
whales, and other marine megafauna, throughout the year; (ii) 
``Trincomalee Canyon and Associated Ecosystems'' and (iii) ``Coastal 
and Offshore Area of the Gulf of Mannar (OBIA Watchlist),'' which also 
encompasses the currently not considered ``Sri Lankan Side of Gulf of 
Mannar'' EBSA. NRDC et al. also recommended that any waters not yet 
included within the boundaries of the new ``South West to Eastern Sri 
Lanka IMMA'' also be advanced for year-round protection.
    Response: The Navy and NMFS assessed areas (i) and (ii) mentioned 
in this comment as potential OBIAs for the blue (pygmy) whale. NMFS and 
the Navy's final assessment of these areas' potential as OBIAs is 
described in Chapter 5 and Appendix C of the 2019 SURTASS LFA FSEIS/
SOEIS. We have also noted in our assessment that although most 
available data for these two areas are for blue whales, data on sperm 
whales have been reported and, where applicable, we note the seasonal 
period during which sperm whale as well as blue whale important 
biological activity occurs.
    Although both the Gulf of Mannar EBSA and IMMA ((iii) of this 
comment) were defined principally for the dugong and coastal dolphins, 
which occur in nearshore or inshore coastal waters too shallow for use 
of SURTASS LFA sonar, because baleen and sperm whale records from MPAs 
located within the Gulf of Mannar EBSA and IMMA are available, the NMFS 
and the Navy further evaluated the Gulf of Mannar region as a potential 
OBIA. The available information and data do not support the area's 
biological importance to blue whales, as only rare blue whale records, 
from strandings, are available for the Gulf of Mannar. Although not 
designated as an OBIA for SURTASS LFA sonar, the Gulf of Mannar has 
been added to the OBIA Watchlist so that data and information about the 
area will continue to be monitored.
    However, most available information and data support the waters off 
southern and eastern Sri Lanka as important migrational and foraging 
areas for both pygmy blue and sperm whales, and both these regions 
include physiographic features and annual monsoonal transport that 
support higher productivity. NMFS and the Navy have designated the 
waters off the entire southern and eastern shore of Sri Lanka to the 
Trincomalee Canyon region as an OBIA for both blue (pygmy) and sperm 
whales.
    C. Southwest India and Western Sri Lanka--NMFS should establish an 
OBIA southwest of India and west of Sri Lanka that reflects the 
boundaries of the new ``Gulf of Mannar and Palk Bay IMMA'' that 
includes the buffer recommended for protection purposes.
    Response: The available data and information are not sufficient for 
the area southwest and west of Sri Lanka to warrant designation as an 
OBIA, as the blue whale data for this area are very sparse and do not 
support designation of this area as biologically important to blue 
whales. Anderson et al. (2012) used ocean color data to develop a 
hypothesis of blue (likely pygmy) whale migration in the northern 
Indian Ocean. Based on their hypothesis, Anderson et al. (2012) 
predicted that blue whales may occur in this area as they migrate from 
the Arabian Sea to eastern Sri Lanka/Bay of Bengal, but the authors 
also note that ``with only a single offshore sighting from April (Table 
1 and Fig. 4), this is one area where additional survey work and/or 
satellite tracking will be required to test our predictions.''
    We conclude that the existing data are insufficient to support 
designating the proposed area as an OBIA for migration or foraging of 
North Indian Ocean blue whales. The proposed area southwest of Sri 
Lanka in the Indian Ocean (3[deg] to 12[deg] N, 74[deg] to 80[deg] E) 
has been added to the OBIA Watchlist, and NMFS and the Navy will 
evaluate the area as a potential OBIA through the Adaptive Management 
Process if new information becomes available.
    D. West of the Maldives (November and April)--NMFS should establish 
an OBIA west of the Maldives that reflects the boundaries described in 
Anderson et al (2012): 1[deg]-6[deg] N, 70.5[deg]-72.5[deg] E.
    Response: Blue whales occur in the area around the Maldives. 
However, the purpose of OBIAs is to protect areas with some 
demonstrated biological importance to a marine mammal species. 
According to Anderson et al. (2012), the highest concentrations of blue 
whales in this area occurred in April, November, and December, with 
strandings having been recorded from December through February. These 
data describe the average seasonal occurrence of blue whales in these

[[Page 40155]]

waters, but are not indicative of high densities nor that biologically 
important activity is occurring in these waters. Occurrence in a marine 
area is not sufficient to establish an area's importance to a species. 
The Navy and NMFS examined all available data and research on blue 
whale occurrence in the waters adjacent to the Maldives to determine if 
biologically important activity of blue whales occurred in these 
waters. As described in the final assessment of the Maldives area as a 
potential OBIA in Chapter 5 and Appendix C of the 2019 SURTASS LFA 
FSEIS/SOEIS, there were no data to support that blue whales conducted 
biologically important activities in this area. The area was not 
designated as an OBIA but has been added to the OBIA Watchlist, and 
NMFS and the Navy will evaluate the area as a potential OBIA through 
the Adaptive Management Process if new information becomes available.
    E. Indonesia--Western Australia migration route--
    1. Citing satellite data from Double et al. (2014), the commenter 
recommended that NMFS/Navy should establish an OBIA encompassing the 
continental shelf along western Australia between March through June 
and September through December. Importantly, the North West Cape/
Ningaloo Reef region, out to the continental shelf edge, needs to be 
protected from at least April through June. The Navy should also take 
measures to avoid the continental shelf edge off northwestern Australia 
between May through July and September through November, to protect 
whales traveling along the migration route.
    Response: The Navy and NMFS have reviewed the Double et al. (2014) 
paper cited herein. We agree that the information cited on the 
migrational area for blue whales was compelling enough to warrant the 
Navy and NMFS researching the area to obtain additional information and 
data on the Western Australia shelf and slope, since the information 
pertains to a LF specialist marine mammal and relates to one of the key 
biological behaviors that define the criteria for OBIAs. The Navy and 
NMFS assessed the entire Western Australia shelf and slope, including 
Browse Basin and the nearby Savu Sea area, as a potential OBIA for blue 
(pygmy) and humpback whales. An OBIA was designated for each species in 
this region. The OBIA for the humpback whale greatly expands the 
geographic extent of OBIA 27, Camden Sound/Kimberly Region in place 
during the NDE.
    2. An OBIA should be established to protect Browse Basin (~14[deg] 
S between 121[deg] E and 124[deg] E) year-round, in light of its 
persistent upwelling and high levels of cetacean diversity, including 
foraging pygmy blue whales.
    Response: The Navy and NMFS designated an OBIA for migrating blue 
(pygmy) whales and vastly expanded the areal extent of the OBIA in 
place during the NDE for humpback whales in the waters off Western 
Australia (Camden Sound/Kimberly Region, OBIA 27 during the NDE). The 
OBIA for the blue whale encompasses Browse Basin and the Savu Sea.
    3. For similar reasons, an OBIA should also be established bounding 
the upwelling system along the southern coasts of Java and the Sumbawa 
Islands, Indonesia. A similar approach to that employed by Anderson et 
al. (2012) could be used to map the boundaries of this region. The 
waters of the newly designated ``Savu Sea and Surrounding Areas IMMA'' 
and the associated buffer recommended for protection should also be 
included.
    Response: Branch et al. (2007) suggest the environmental factors 
``driving biological enrichment and enhanced blue whale foraging'' and 
the regional location of such factors, which have been cited in this 
comment. The upwelling information in Branch et al. (2007) is based on 
Hendiarti et al. (2004). Hendiarti et al. (2004) note that the majority 
of the upwelling in the southern Indonesian region occurs seasonally 
off southeastern Java. It is also difficult to discern from the data 
presented in Hendiarti et al. (2004) how much of the coastal upwelling 
would occur within the coastal standoff range of SURTASS LFA sonar, as 
much of the higher productivity appears to take place nearshore.
    However, more importantly, while an upwelling area has potential, 
at least seasonally, as an important foraging area for cetaceans, a 
species' seasonal occurrence as denoted by higher relative abundance in 
that area would indicate increased foraging during the period of 
increased productivity. However, NMFS and the Navy conducted a thorough 
review of the best available data and no data are available to support 
the association of blue whales foraging in this area in Indonesia. 
Therefore, this area does not meet the criteria for establishing an 
OBIA. The area has been added to the OBIA Watchlist, and NMFS and the 
Navy will evaluate the area as a potential OBIA through the Adaptive 
Management Process if new information becomes available.
    Comment 37: NRDC et al. recommended that for humpback whales:
    A. Northern Arabian Sea--The Arabian Sea DPS is a small, highly 
isolated, resident population that requires an OBIA encompassing all 
waters north of 21[deg]50' N from the western coast of India westward 
to the boundary of the proposed SURTASS LFA study area.
    Response: The endangered Arabian Sea DPS of humpback whales is 
geographically, genetically, and demographically isolated from all 
other populations of humpback whales. Research surveys over the past 30 
years have confirmed the continuous presence of humpback whales in the 
shallow, nearshore waters of the Arabian Sea off Oman, which is not in 
the SURTASS LFA sonar Study Area. Only a limited and incidental number 
of humpback whale sightings (13 recorded humpbacks by the Marine Mammal 
Conservation Network of India, with records beginning in 1943), passive 
acoustic detections, strandings, and one tagging record have been 
reported from the eastern Arabian Sea off Pakistan and western India, 
with only the waters off western India being located within the SURTASS 
LFA sonar Study Area. Given the small population size and the well-
documented concentration of this DPS in the western Arabian Sea, the 
Navy concluded, and NMFs agreed, that the likelihood of humpback whales 
from the Arabian Sea DPS being located in the waters of the 
northwestern most part of the Study Area was vanishingly small.
    However, as part of the OBIA process and upon the recommendation of 
public comments on the 2018 SURTASS LFA Draft SEIS/SOEIS and MMPA 
proposed rule, NMFS and the Navy assessed all available data and 
information on humpback whales in the waters off western India and the 
nearby Lakshadweep Archipelago. See Area 32 of Appendix C of the 2019 
SURTASS LFA FSEIS/SOEIS for review of the scientific literature 
available for this region, which includes assessment of three 
recommended OBIAs encompassing the west and south coast of India: One 
in the Northern Arabian Sea (north of 21[deg]50' N from the western 
coast of India westward to the boundary of the SURTASS LFA study area); 
one along the coast of west coast of India from Konkan and Malabar out 
to 60 km (32.4 nmi) from shore; and one along the south coast of India 
from Muttom to Kanyakumari out to include Wadge Bank. Although several 
records indicate that rare occurrences of humpback whales from the 
Arabian Sea DPS have been reported from the waters off central and 
southern Western India, these records are far too sparse to suggest a 
regular occurrence of part of

[[Page 40156]]

the Arabian Sea population of humpbacks off western India. For this 
reason, the Navy made the decision not to include the Arabian Sea DPS 
of humpback whales in the 2019 SURTASS LFA FSEIS/SOEIS nor in 
associated documentation, including the ESA Biological Evaluation for 
SURTASS LFA sonar. However, due the potential for important migrational 
activity of humpbacks in these waters, the waters of western and 
southern India were added to the OBIA Watchlist and NMFS and the Navy 
will evaluate the area as a potential OBIA through the Adaptive 
Management Process if new information becomes available.
    B. Maldives Archipelago--Given the importance of this area for 
multiple species, including Arabian Sea and Southern Ocean humpback 
whales, and Bryde's whales, NMFS should establish an OBIA encompassing 
the waters within 30 nmi of the archipelago baseline.
    Response: Humpback whales and Bryde's whales occur in the area 
around the Maldives. Again, however, occurrence in a marine area is not 
sufficient to establish its importance to a species. The Navy and NMFS 
examined all available data and research on whale occurrence in the 
waters adjacent to the Maldives to determine if whales conduct 
biologically important activities in these waters. As described in the 
final assessment of the Maldives area as a potential OBIA in Chapter 5 
and Appendix C of the 2019 SURTASS LFA FSEIS/SOEIS, there were no data 
to support that whales conduct biologically important activities in 
this area. The area was not designated as an OBIA; however, it has been 
added to the OBIA Watchlist and NMFS and the Navy will evaluate the 
area as a potential OBIA through the Adaptive Management Process if new 
information becomes available.
    C. Konkan and Malabar Coast--NMFS should establish an OBIA to 
protect this important habitat area for Arabian Sea humpback whales, 
blue whales, and Bryde's whales (See Figure 2 for proposed approximate 
boundaries).
    Response: See response to Comment 37A above. NMFS and the Navy 
assessed all available data and information on humpback, blue, and 
Bryde's whales for the West and South Coasts of India area (see Area 32 
in Appendix C of the 2019 SURTASS LFA FSEIS/SOEIS for review of the 
scientific literature available for this region, which includes 
assessment of three recommended OBIAs encompassing the west and south 
coast of India: One in the Northern Arabian Sea (north of north of 
21[deg]50' N from the western coast of India westward to the boundary 
of the SURTASS LFA study area); one along the coast of west coast of 
India from Konkan and Malabar out to 60 km (32.4 nmi) from shore; and 
one along the south coast of India from Muttom to Kanyakumari out to 
include Wadge Bank). There was no evidence that biologically important 
activities are conducted in this area. The area was not designated as 
an OBIA, however it has been added to the OBIA Watchlist and NMFS and 
the Navy will evaluate the area as a potential OBIA through the 
Adaptive Management Process if new information becomes available.
    D. Muttom-Kanyakumari and Wadge Bank, southern India--NMFS should 
establish an OBIA to protect this important foraging habitat area for 
Arabian Sea humpback whales and potentially other baleen whale species 
(See Figure 3 for proposed approximate boundaries).
    Response: See response to Comment 37A above.
    E. Northwestern Pacific Breeding Areas--NMFS should afford 
protection to: (i) The Okinawa/Philippines humpback whale DPS by 
establishing an OBIA encompassing waters less than 200 m deep--typical 
of humpback whale wintering habitat--surrounding the islands of Okinawa 
from January to April and the islands of Ogasawara from December to 
June. The commenters note that Ogasawara is included on NMFS' list of 
potential OBIAs (84 FR at Table 21, 7) and strongly recommend that this 
area be carried forward for inclusion and expanded to the 200 m depth 
contour; and (ii) The newly designated ``Babuyan Marine Corridor IMMA'' 
and buffer recommended for protection, primarily identified as the only 
breeding area for humpback whales in the Philippines.
    Response: The area around the islands of Ogasawara was designated 
as an OBIA for humpback whales from December to May (this area was also 
designated for sperm whales from June to September). Although humpback 
whales are observed in relatively shallow waters of the Ogasawara and 
Kazin Islands, humpbacks move between the islands. Male humpback whales 
are also observed in deeper more offshore waters than are female 
humpbacks with calves. Last, the specific location where breeding and 
calving occur in this area is unknown. Given that lack of knowledge and 
to accommodate the deeper water movements of male humpbacks, the OBIA 
boundary around the Ogasawara and Kazin Islands was offset from the 
coastal standoff zone by less than 4 nmi (7.4 km). A straight-line 
corridor to accommodate migrating humpbacks that are traveling between 
the Ogasawara and Kazin Islands was also included.
    The area surrounding the islands of Okinawa was designated as part 
of the Ryukyu-Philippines OBIA. As recommended all areas of the Babuyan 
Marine Corridor IMMA outside of the coastal standoff zone were 
designated as part of the Ryukyu-Philippines OBIA. The Ryukyu-
Philippines OBIA is designated seasonally from January to April 
(Okinawa) and late February to April (Philippines). Based on the best 
available information, the boundary for the Ryukyu-Philippines OBIA was 
derived by creating a buffer that was offset from the coastal standoff 
range by less than 2 nmi (3.7 km) around the majority of the Ryukyu 
Islands and Babuyan Islands, with straight lines creating transit 
corridors between the Ryukyu Islands, the eastern Taiwan coast, and the 
Babuyan Islands off the northern Philippines. The boundary off eastern 
Taiwan was created as a straight line less than 3 nmi (5.6 km) from the 
Taiwanese coastal standoff range. Although the Ryukyu Islands extend 
all the way to Kyushu Island of the main Japanese islands, since no 
records indicate humpback whales are sighted in these waters of the 
northern Ryukyu Islands, the OBIA boundary extends only as far north as 
Amami Island.
    F. Northwestern Pacific Feeding Areas--NMFS should establish: (i) 
An OBIA extending from the east Kamchatka coastline offshore to the 
continental shelf break (encompassing the ``Watchlist'' OBIA 
``Southeast Kamchatka Coastal waters''), from June through September; 
and (ii) an OBIA reflecting the boundaries of the ``Commander Islands 
Shelf and Slope EBSA,'' which has not yet been considered.
    Response: The Commander Islands Shelf and Slope EBSA was not 
included for consideration as an OBIA, because the area lies outside 
the SURTASS LFA sonar Study Area, and as such, is not eligible for 
consideration as an OBIA.
    NMFS and the Navy considered the Southeast Kamchatka Coastal Waters 
(although it was not on the OBIA Watchlist) and designated an OBIA off 
southeastern Kamchatka. Further details on the seasonal restrictions 
and areal extent may be found in Appendix C of the 2019 SURTASS LFA 
FSEIS/SOEIS.
    Comment 38: NRDC et al. recommended that for Bryde's whales NMFS 
designate a year-round OBIA reflecting the boundaries of both the 
``Coastal Northern Bay of Bengal IMMA'' and the ``Swatch-of-No-Ground 
IMMA,'' and their associated buffers

[[Page 40157]]

designed to inform place-based conservation measures.
    Response: The Coastal Northern Bay of Bengal IMMA was assessed but 
not carried forward as a potential OBIA because it is relevant to 
marine mammal species known to only frequent inshore waters (Irrawaddy, 
Indo-Pacific finless, and Indo-Pacific humpback dolphins). These 
species are not anticipated to be impacted by SURTASS LFA sonar 
training and testing activities. NMFS and the Navy have designated the 
Swatch-of-No-Ground (SoNG) OBIA. The SoNG IMMA encompasses the waters 
of the Head of the SoNG canyon (MMPATF, 2019), which were not fully 
encompassed in the existing OBIA 20. The SoNG IMMA boundary fully 
captures the foraging habitat where Bryde's whales have been identified 
(Smith et al., 2008; WCS Bangladesh, 2014). The SoNG OBIA for this 
final rule combines OBIA 20, Northern Bay of Bengal and Head of SoNG 
OBIA (in place during the NDE) and the SoNG IMMA.
    Comment 39: NRDC et al. recommended that for gray whales, NMFS 
establish an OBIA off eastern Japan extending from the coast out to the 
continental shelf edge from March through May.
    Response: In consideration of the Convection Zone East of Honshu 
EBSA for baleen whales, the Navy and NMFS evaluated a migrational 
corridor just off the coastal standoff range along eastern Honshu 
island for the western gray whale DPS. NMFS with Navy input designated 
an OBIA in this area off eastern Honshu for gray whale migration. 
Additional details on the areal extent and seasonal restrictions are 
provided in Appendix C of the 2019 SURTASS LFA FSEIS/SOEIS.
    Comment 40: NRDC et al. recommended that for sei whales, NMFS 
establish an OBIA that extends from the Polar Front boundary southwards 
towards the Kuroshio Extension Front (i.e., approximately 45[deg] N to 
35[deg] N, 152[deg] E to 170[deg] E) to protect foraging sei whales 
(i.e., the ``Polar/Kuroshio Extension Front'' area that NMFS identified 
in the proposed rule as a potential OBIA). They stated that protecting 
this highly productive foraging area would have broad benefit for a 
number of marine mammal species, including sperm whales, other 
odontocetes, and elephant seals.
    Response: The Navy and NMFS evaluated the Polar/Kuroshio Extension 
Fronts region as recommended by the commenter. Additionally, the Navy 
and NMFS assessed the North Pacific Transition Zone EBSA (which 
encompasses these fronts) for its importance to the northern elephant 
seal. Although it is true that the North Pacific Transition Zone 
(NPTZ), Polar Front, and Kuroshio Extension Front are defined as 
oceanographic frontal zones that are large spatially persistent 
features, the physical, chemical, and even biological features by which 
each frontal zone is defined, including the species associated with 
them, are unique and not consistent across frontal zones. It would, 
therefore, be scientifically inappropriate to combine the frontal areas 
into one large combined area as suggested and disregard the defining 
features of the respective frontal zones and the data associated with 
each. The Navy and NMFS are aware of the suggested correlation of 
oceanographic frontal features with sei whale foraging and reviewed the 
available information on foraging areas for the North Pacific sei whale 
population. However, data and information are currently insufficient to 
correlate specific oceanographic frontal features or their boundaries 
in the northwestern Pacific with biologically important behavior of sei 
whales. Although neither the Polar/Kuroshio Extension Fronts nor NPTZ 
have been designated as OBIAs, both marine areas have been added to the 
OBIA Watchlist. The Navy and NMFS will continue to compile and evaluate 
data and information on both areas and will reassess them in the future 
through the Adaptive Management process.
    Comment 41: NRDC et al. recommended that for sperm whales:
    A. Waters off Sri Lanka--Similar to blue whales, NMFS should 
advance the following three areas currently being considered by NMFS as 
year-round mitigation areas for both blue and sperm whales (and, in 
some cases, Bryde's whales): (i) ``Southern Coastal/Offshore Waters 
between Galle and Yala National Park'', (ii) ``Trincomalee Canyon and 
Associated Ecosystems'', and (iii) ``Coastal and Offshore Area of the 
Gulf of Mannar'' (OBIA Watchlist), which also encompasses the currently 
not considered ``Sri Lankan Side of Gulf of Mannar'' EBSA.
    Response: See response to Comment 36.
    B. Lakshadweep Archipelago--NMFS should consider designating an 
OBIA to encompass the entirety of the Lakshadweep Archipelago and the 
waters therein.
    Response: In assessing this area as a potential OBIA, NMFS and the 
Navy conducted a thorough review of the available information on marine 
mammal occurrence in the Lakshadweep Archipelago. Very little 
information is available on marine mammal occurrence in the Lakshadweep 
Archipelago, with very few survey sightings of cetaceans or stranding 
data. Because of this lack of data there is no indication that this 
area supports important biological activities for marine mammals and, 
therefore, it does not meet the biological criteria for designation as 
an OBIA or otherwise warrant inclusion as a mitigation area pursuant to 
the LPAI standard. However the Lakshadweep Archipelago has been added 
to the OBIA Watchlist and NMFS and the Navy will evaluate the area as a 
potential OBIA through the Adaptive Management Process if new 
information becomes available.
    C. Northwestern Pacific--To protect foraging areas for sperm 
whales, NMFS should utilize the boundaries of three historic whaling 
grounds (i.e., Japan Ground, Coast of Japan Ground, and Japan-Bonin 
Island Ground) to delineate OBIAs for sperm whales in the Northwestern 
Pacific Ocean (following the areas described in Ivashchenko et al. 
(2014); Fig. 9). They noted that the Japan Ground area is generally 
consistent with that of the ``Polar/Kurioshio Extension Fronts'' area 
that NMFS is currently considering.
    Response: NMFS and the Navy did not consider the major areas of 
sperm whale concentration outlined in Ivashchenko et al. (2014) when 
assessing the North Pacific Transition Zone EBSA as we did not consider 
these areas either singly or in combination to be coincident with the 
boundary of the North Pacific Transition Zone EBSA. While the whaling 
data compiled by Ivaschenko et al. (2014) provide valuable information 
on the historical extent of the North Pacific sperm whale distribution, 
those locations cannot be used without other supporting data to create 
OBIAs reflective of areas where sperm whales conduct important 
biological activities. These areas of historical concentrations provide 
no insights into what important biological activities are occurring in 
the areas. Many cetacean species became extirpated and never 
repopulated heavily exploited commercial whaling grounds, so basing 
current occurrences for a species solely on whaling ground data is not 
appropriate; those data provide a historical perspective on occurrence 
and distribution but cannot be used as a current template of a species' 
occurrence. Accordingly, these areas were not considered as potential 
OBIAs.
    Comment 42: NRDC et al. recommended a year-round OBIA in the waters 
of the Avacha Gulf to protect important foraging habitat and transitory 
corridor for killer whales.

[[Page 40158]]

NRDC et al. noted that the small population size and cumulative impacts 
upon mammal-eating killer whales in this area should be carefully 
considered by NMFS and that neglecting to include the best available 
science on the population structure, ecotypes, and abundance estimates 
of killer whales in this region is a major oversight of the proposed 
rule.
    Response: NMFS and Navy are aware of the importance of southeastern 
Kamchatka and Avacha Gulf to resident killer whales and have assessed 
the wealth of survey data and information on this population of 
odontocetes and the importance of the area, particularly Avacha Gulf, 
to this population. However, the majority of Avacha Gulf, including the 
core area where most sightings of resident killer whales have been 
recorded, lies within the coastal standoff zone for SURTASS LFA sonar. 
To be eligible as an OBIA, a marine area must meet geographic criteria, 
one of which is that the area must lie outside the coastal standoff 
range for LFA sonar (i.e., be more than 12 nmi (22 km) from shore). 
Furthermore, OBIA designation is designed to provide protection to 
those marine mammal species most likely to be impacted by LFA sonar, 
which are the LF-sensitive species. There is no evidence that killer 
whales have increased sensitivity to LF sounds. Therefore, we do not 
believe an OBIA will add meaningful protection beyond that provided by 
the LFA sonar mitigation zone (described in the Mitigation section). 
These factors render this marine area ineligible for consideration as 
an OBIA for SURTASS LFA sonar. However, an OBIA in southeastern 
Kamchatka waters outside the coastal standoff range has been designated 
for gray and right whales that migrate and forage seasonally in these 
waters. Thus, albeit not designated specifically for resident killer 
whales in this area, the OBIA will reduce the exposure of some resident 
killer whales to LFA sonar.
    Comment 43: NRDC et al. stated a more comprehensive evaluation of 
important habitat for harbor porpoises and beaked whales is needed, 
however they recommended that NMFS establish OBIAs in waters outside 
the coastal exclusion zone that are contained within the Biologically 
Important Areas for Blainville's and Cuvier's beaked whales, as well as 
for other small, resident odontocete populations, around the Main 
Hawaiian Islands, as defined in Baird et al. (2015).
    Response: One of the factors considered for designation of OBIAs, 
established in the 2012 rulemaking and SURTASS LFA FSEIS/SOEIS and 
carried forward in the current OBIA assessment process, is sensitivity 
to LF sounds. The intent of OBIAs is to protect those marine mammal 
species most likely to hear and be affected by LFA sonar transmissions 
and to provide them with additional protections during periods when 
they are conducting biologically significant activities. Based on 
current information, neither Blainville's nor Cuvier's beaked whales 
are known to have increased sensitivity to LF sounds, therefore we do 
not believe added protection afforded by an OBIA (i.e., beyond that by 
the LFA sonar mitigation zone described in the Mitigation section) is 
warranted. However, a large portion of the BIAs are included in the 
Main Hawaiian Islands OBIA designated for other species.
    Comment 44: NRDC et al. recommended that NMFS include critical 
habitat that NMFS recently designated, under the Endangered Species 
Act, for the Main Hawaiian Islands insular false killer whale.
    Response: NMFS and the Navy assessed the ESA-designated critical 
habitat for the Main Hawaiian Insular DPS of false killer whales as a 
potential OBIA. However, there is no evidence that false killer whales 
have increased sensitivity to LF sounds. Therefore, we do not believe 
an OBIA will afford more protection than what is provided by the LFA 
sonar mitigation zone (described in the Mitigation section). False 
killer whales hear underwater sounds in the range of 1 to 115 kHz, with 
best hearing at 17 kHz (Au, 1993; Johnson, 1967). Nevertheless, a large 
portion of the ESA critical habitat for the Main Hawaiian Insular DPS 
of false killer whales is included in the newly designated Main 
Hawaiian Islands OBIA (November to April), and per the CZMA 
consultation with the State of Hawaii for SURTASS LFA sonar, the Navy 
agreed not to ensonify Hawaii state waters (out to 3 nmi) at levels 
above 145 dB re: 1 [mu]Pa rms.
    Comment 45: NRDC et al. recommended that NMFS establish a year-
round OBIA at Cross Seamount, which represents important foraging 
habitat for a potentially rare or evolutionarily distinct species of 
beaked whale. They noted that such a designation would have secondary 
benefits for a variety of other odontocete species foraging at Cross 
Seamount seasonally between November and May.
    Response: The Cross Seamount is within the SURTASS LFA sonar Study 
Area and is known for prey aggregations that support beaked whale 
foraging, as inferred by the detection of beaked whale echolocation 
signals at night. However, there is no supporting information or data 
to suggest that the waters surrounding this seamount support higher 
than average densities of beaked whales and no small-resident 
populations have been confirmed, which would qualify as a biological 
criterion for delineation of an OBIA in the region. Additionally, based 
on current information, beaked whales are not known to have increased 
sensitivity to LF sounds, therefore we do not believe added protection 
afforded by an OBIA (i.e., beyond that provided by the LFA buffer zone, 
described in the Mitigation section) is warranted to protect beaked 
whales foraging in the waters of Cross Seamount. However through the 
adaptive management process, NMFS and the Navy will evaluate new 
information as it becomes available.
    Comment 46: The Commission noted that 14 of the 25 potential OBIAs 
(as described in Table 21 of the proposed rule) meet the various low 
frequency-sensitivity and biological importance criteria and occur 
within the SURTASS LFA sonar mission areas and, at least partially, 
outside the coastal stand-off range where SURTASS LFA sonar activities 
already are restricted. The Commission suggests these areas should be 
designated as OBIAs. Additionally, the Commission noted that Raja Ampat 
and Northern Bird's Head serve as important habitat for migrating and/
or foraging Bryde's and sperm whales and the Main Hawaiian Archipelago 
serves as important habitat for breeding and calving humpback whales. 
In addition, Peter the Great Bay serves as important breeding habitat 
for spotted seals. All of those species are sensitive to LF sound, and 
portions of those potential OBIAs meet the geographic criteria as well. 
The Commission also notes that the Pacific Remote Islands Marine 
National Monument (MNM), including areas around Wake and Johnston 
Atolls and a small part of the northern end of Kingman Reef/Palmyra 
Atoll, meet the geographic criteria. Although marine mammal data are 
limited, sperm whales have been observed in the MNM and the Navy noted 
that the MNM could serve as potential critical habitat for some 
threatened and endangered species (e.g., humpback whales). Baleen and 
sperm whales are considered sensitive to low-frequency sound. For these 
reasons, the Commission recommended that NMFS include these areas as 
OBIAs in the final rule.
    Response: Fourteen OBIAs were designated. Of the 14 OBIAs presented 
in Table 21 of the proposed rule, all but the West of Maldives was 
designated as an OBIA. The West of Maldives area was not designated 
because there were

[[Page 40159]]

no data to support that whales conducted biologically important 
activities in this area. The West of Maldives area has been added to 
the OBIA Watchlist (see response to Comment 36). As recommended, an 
OBIA has also been designated for the Main Hawaiian Islands.
    Raja Ampat and Northern Bird's Head was considered as a candidate 
OBIA. However, none of the areas surveyed in any of the best available 
data occur within the SURTASS LFA sonar Study Area. Since no data exist 
to support important biological activities by marine mammals being 
carried out in the part of this marine area that lies within the 
SURTASS LFA Study Area, this area did not meet the biological criteria 
for OBIA designation and was not considered further as an OBIA. The 
area has been added to the OBIA Watchlist, and NMFS and the Navy will 
evaluate the area as a potential OBIA through the Adaptive Management 
Process if new information becomes available.
    Peter the Great Bay was considered as a candidate OBIA. Only a 
small portion of Peter the Great Bay lies outside the coastal standoff 
zone and thus meets the geographic criteria. While Peter the Great Bay 
is an important seasonal reproductive area for the spotted seal, 
pupping activities are conducted in the northern reaches of the bay, 
well within the coastal standoff zone, and no pupping or reproductive 
activity is known to occur in the portion of the bay outside the 
coastal standoff zone. Further, based on currently available 
information and data, the spotted seal is not known to have increased 
sensitivity to LF sound; the best hearing sensitivity in-water of the 
spotted seal is between 2 and 72 kHz (Reichmuth et al., 2013; Sills et 
al., 2014). Reichmuth et al. (2016) found no TTS in trained spotted 
seals exposed to LF impulsive sounds that represented single seismic 
air gun transmissions (which are different from LFA sonar signals). As 
such, an OBIA is not warranted. For these reasons, the IMMA for Peter 
the Great Bay was not further considered as an OBIA for SURTASS LFA 
sonar.
    The Pacific Remote Islands Marine National Monument (Wake/Johnson/
Palmyra atolls and Kingman Reef Units which are located in the SURTASS 
LFA Study Area) was on the OBIA Watchlist and was considered as a 
candidate OBIA. NMFS and the Navy reviewed all available data and no 
specific important biological behaviors of marine mammals have been 
characterized in these waters. As such, this marine area did not meet 
the biological criteria required for designation of an OBIA and was not 
further considered currently as an OBIA.
Practicability Analysis
    Comment 47: NRDC et al. noted that the Navy's application 
distinguishes among types of LFA activities, ranging from ``military 
crew (MILCREW) proficiency training'' to ``vessel and equipment 
maintenance.'' NRDC et al. stated that these categories suggest that 
geographic mitigation could potentially be implemented for a subset of 
activities in the case that blanket geographic mitigation is deemed 
impracticable--a development that could, if rigorously applied, 
substantially improve mitigation and help NMFS and the Navy meet their 
MMPA responsibilities. In its practicability analysis for OBIAs, NRDC 
et al. recommended that NMFS analyze the practicability of mitigating 
each individual category of activity and implement mitigation measures 
to the greatest extent practicable for each category. NRDC et al. 
stated that such an approach will serve to reduce potential impact to 
marine mammals in an OBIA even if not all Navy activities can 
practicably be mitigated.
    Response: The Navy and NMFS' OBIA assessment resulted in 14 
candidate OBIAs. These 14 candidate OBIAs underwent Navy Fleet 
practicability review and the Navy Fleet determined that the 
designation of the 14 OBIAs in the SURTASS LFA sonar Study Area for the 
relevant effective periods would not impede the effectiveness of 
SURTASS LFA active sonar testing and training activities, would be 
practical to implement as a geographic mitigation measure, and would 
not impact personnel safety. As a result, all 14 candidate OBIAs were 
deemed practicable and 14 new, marine mammal OBIAs for SURTASS LFA 
sonar have been designated (see the Mitigation section and Table 21) 
and apply to all SURTASS LFA sonar training and testing activities. 
Therefore, analysis of practicability for different types of activities 
is not necessary.
    Additionally, all of the activities utilize the SURTASS LFA sonar 
system within the same operating profile, such that any single hour of 
SURTASS LFA sonar transmissions is the same as all others. The 
differentiation of activities was merely for planning purposes, to aid 
in determining the overall number of transmission hours per year for 
SURTASS LFA sonar training and testing. It is not practicable to 
develop geographic mitigation measures for each activity.
    Comment 48: NRDC et al. recommended that NMFS, in consultation with 
the Navy, establish geographic alternatives for OBIAs that raise 
practicability concerns for certain categories of LFA activity. Given 
the importance of site-selection in minimizing environmental impacts, 
it is conventional for agencies to analyze the environmental effects of 
alternative sites that meet the activity's purpose and need. They 
stated that doing so is essential where, as here, protected habitat is 
of ``paramount importance''.
    Response: As previously noted in the response to Comment 47, all 14 
candidate OBIAs were deemed practicable and 14 new marine mammal OBIAs 
for SURTASS LFA sonar have been designated (see the Mitigation section 
and Table 21), therefore geographic alternatives for OBIAs are not 
necessary.
    Comment 49: NRDC et al. recommended where reasonable alternative 
sites are not available, NMFS, in consultation with the Navy, consider 
other mitigation measures, including procedural requirements (e.g., 
requiring Fleet-level approval for use), substantive standards (e.g., 
allowing use only when certain criteria are met), and activity limits 
(e.g., limiting the number of activities per annum or avoiding 
biologically important periods such as the blue whale foraging season), 
that would protect vital habitat while allowing continued use for 
training purposes. They stated that the Navy, in the ``practicability 
criterion'' it sets forth in the DSEIS, commits to identifying for NMFS 
the concerns that lead to its determination that a particular OBIA is 
not practicable, and discussing ``whether modifications could be made 
to the proposed OBIA to alleviate the Navy's practicability concerns.'' 
(DSEIS at 5-8). NRDC et al. recommended that both agencies work to 
ensure that the resulting analysis is rigorous and searching, rather 
than a parroting of Navy conclusions (citing Conservation Council for 
Hawaii v. NMFS, 97 F.Supp.3d 1210, 1230 (D. Haw. 2015)).
    Response: As previously noted in the response to Comment 48, all 14 
candidate OBIAs were deemed practicable and 14 new marine mammal OBIAs 
for SURTASS LFA sonar have been designated (see the Mitigation section 
and Table 21), so there is no need to identify geographic alternative 
sites for OBIAs. As described in the Mitigation section, these OBIAs, 
in combination with the existing procedural mitigation effect the least 
practicable adverse impact.
    Comment 50: NRDC et al. recommended to the extent that additional 
operational mitigation is impracticable, NMFS consider compensatory 
mitigation to achieve the

[[Page 40160]]

``least practicable adverse impact'' required under the MMPA. NRDC et 
al. stated that compensatory mitigation is a concept that is routinely 
employed in implementation of the Endangered Species Act, Clean Water 
Act, and other environmental laws. The MMPA itself is broad in its 
characterization of mitigation, requiring the agency to prescribe not 
only ``permissible methods of taking pursuant to [a specified 
activity],'' but also ``other means of effecting the least practicable 
adverse impact'' on affected marine mammal species and populations and 
on their habitat. 16 U.S.C. 1371(a)(5)(A)(II)(aa) (emphasis added). 
NRDC et al. stated that the Ninth Circuit opinion in Pritzker makes 
clear, this requirement should be construed by the agency as a 
``stringent standard.'' 828 F.3d at 1129, 1133, 1135. NRDC et al. 
recommended that NMFS consider compensatory mitigation for the adverse 
impacts of the permitted activity on marine mammals and their habitat 
that cannot be prevented or mitigated by modifying SURTASS LFA 
operations.
    Response: As previously noted in the response to Comment 47, all 14 
candidate OBIAs were deemed practicable and 14 new, marine mammal OBIAs 
for SURTASS LFA sonar have been designated (see the Mitigation section 
and Table 21), therefore other mitigation measures for these areas are 
not necessary. NMFS has prescribed a robust comprehensive suite of 
measures that are expected to reduce the amount of Level A and Level B 
harassment takes, as well as the severity of any incurred impacts on 
the species or stock and their habitat. Compensatory mitigation is not 
required to be imposed upon Federal agencies under the MMPA. 
Importantly, the commenter did not recommend any specific measure(s), 
rendering it impossible to conduct any meaningful evaluation of its 
recommendation. Finally, many of the methods of compensatory mitigation 
that have proven successful in terrestrial settings (purchasing or 
preserving land with important habitat, improving habitat through 
plantings, etc.) are not applicable in a marine setting with such far-
ranging species. Thus, any presumed conservation value from such an 
idea would be purely speculative at this time.

National Environmental Policy Act (NEPA)

    Comment 51: NRDC et al. stated that NMFS cannot rely on the Navy's 
EIS to fulfill its obligations under NEPA because it is unlawful. They 
stated that the Navy's DEIS serves only the Navy's interests, 
considering only the purpose and need of military readiness, thus 
limiting the range of alternatives and mitigation. They noted that the 
Navy's purpose and need is unrelated to NMFS' statutory obligations 
under the MMPA. Those obligations in this instance involve prescribing 
regulations for the incidental take of marine mammals that effect the 
least practicable adverse impact on such species or stock and its 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance, and on the availability of such species 
or stock for subsistence uses (16 U.S.C. 1371(a)(5)(A)(i)). While 
military readiness effectiveness must be considered, id. Sec.  
1371(a)(5)(ii), the ultimate purpose of the MMPA is to protect marine 
mammals, and NMFS is charged with that duty. Thus, they stated that 
NMFS has a distinct purpose and need for its proposed regulations that 
may dictate consideration of a broader set of alternatives.
    Response: The proposed action at issue is the Navy's proposal to 
conduct SURTASS LFA sonar testing and training activities in the 
SURTASS LFA Study Area. NOAA's NMFS is a cooperating agency for that 
proposed action, as it has jurisdiction by law and special expertise 
over marine resources impacted by the proposed action, including marine 
mammals and federally-listed threatened and endangered species. 
Consistent with the regulations published by the Council on 
Environmental Quality (CEQ), it is common and sound NEPA practice for 
NOAA to adopt a lead agency's NEPA analysis when, after independent 
review, NOAA determines the document to be sufficient in accordance 
with 40 CFR 1506.3. Specifically here, NOAA must be satisfied that the 
Navy's EIS adequately addresses the impacts of issuing the MMPA 
incidental take authorization and that NOAA's comments and concerns 
have been adequately addressed. There is no requirement in CEQ 
regulations that NMFS, as a cooperating agency, issue a separate 
purpose and need statement in order to ensure adequacy and sufficiency 
for adoption. Nevertheless, the Navy, in coordination with NMFS, has 
clarified the statement of purpose and need in the 2019 SURTASS LFA 
FSEIS/SOEIS to more explicitly acknowledge NMFS' action of issuing an 
MMPA incidental take authorization. NMFS also clarified how its 
regulatory role under the MMPA related to Navy's activities. NMFS' 
early participation in the NEPA process and role in shaping and 
informing analyses using its special expertise ensured that the 
analysis in the 2019 SURTASS LFA FSEIS/SOEIS is sufficient for purposes 
of NMFS' own NEPA obligations related to its issuance of incidental 
take authorization under the MMPA.
    Regarding the alternatives, NMFS' early involvement in the 
development of the 2019 SURTASS LFA FSEIS/SOEIS and role in evaluating 
the effects of incidental take under the MMPA ensured that the 2018 
SURTASS LFA DSEIS/SOEIS would include adequate analysis of a reasonable 
range of alternatives. The 2019 SURTASS LFA FSEIS/SOEIS includes a No 
Action Alternative specifically to address what could happen if NMFS 
did not issue an MMPA authorization. The other two Alternatives address 
two action options that the Navy could potentially pursue while also 
meeting their mandated Title 10 training and testing responsibilities. 
More importantly, these alternatives fully analyze a comprehensive 
variety of mitigation measures. This mitigation analysis supported 
NMFS' evaluation of our options in potentially issuing an MMPA 
authorization, which primarily revolves around the appropriate 
mitigation to prescribe. This approach to evaluating a reasonable range 
of alternatives is consistent with NMFS policy and practice for issuing 
MMPA incidental take authorizations. NOAA has independently reviewed 
and evaluated the SEIS, including the purpose and need statement and 
range of alternatives, and determined that the 2019 SURTASS LFA FSEIS/
SOEIS fully satisfies NMFS' NEPA obligations related to its decision to 
issue the MMPA final rule and associated LOA, and we have adopted it.

Description of Marine Mammals in the Area of the Specified Activities

    Forty-six species of marine mammals, including 10 baleen whale 
(mysticete); 31 toothed whale (odontocete); and 5 seal/sea lion 
(pinniped) species that represent 139 stocks (as currently classified) 
have confirmed or possible occurrence within potential SURTASS LFA 
sonar activity areas in the central and western North Pacific Ocean and 
eastern Indian Ocean. Multiple stocks of some species are affected, and 
independent assessments are conducted to make the necessary findings 
and determinations for each of these.
    There are 11 marine mammal species under NMFS' jurisdiction listed 
as endangered or threatened under the Endangered Species Act (ESA; 16 
U.S.C. 1531 et seq.) with confirmed or possible occurrence in the study 
area for SURTASS LFA sonar training and testing activities. Marine 
mammal species under NMFS' jurisdiction in the

[[Page 40161]]

study area listed as endangered are: North Pacific right whale 
(Eubalaena japonica); gray whale (Eschrichtius robustus); blue whale 
(Balaenoptera musculus); fin whale (Balaenoptera physalus); Western 
North Pacific distinct population segment (DPS) of humpback whale 
(Megaptera novaeangliae); sei whale (Balaenoptera borealis); sperm 
whale (Physeter macrocephalus); Main Hawaiian Islands Insular DPS of 
false killer whale (Pseudorca crassidens); Western DPS of the Steller 
sea lion (Eumetopias jubatus); and Hawaiian monk seal (Neomonachus 
schauinslandi). The southern DPS of the spotted seal (Phoca largha) is 
listed as threatened under the ESA and is within the study area for 
SURTASS LFA sonar activities. The aforementioned threatened and 
endangered marine mammal species also are depleted under the MMPA.
    Chinese river dolphins (Lipotes vexillifer) do not have stocks 
designated within the SURTASS LFA sonar study area (see Potential 
SURTASS LFA Study Area section). The distribution of the Chinese river 
dolphin is limited to the main channel of a river section between the 
cities of Jingzhou and Jiangyin. Based on the extremely rare occurrence 
of these species in the Navy's Study Area and due to the coastal 
standoff range (i.e., distance of 22 km (13 mi; 12 nmi) from land), 
take of Chinese river dolphins is not considered a reasonable 
likelihood; therefore, this species is not addressed further in this 
document. Similarly, the Taiwanese humpback dolphin, a subspecies of 
the Indo-Pacific humpback dolphin, is found only in a small, narrow 
stretch of estuarine waters off the western coast of Taiwan. Take of 
this species is also not considered a reasonable likelihood and this 
species is not addressed further in this document. Finally, the small 
population (<100 individuals) of Arabian Sea DPS of humpback whales 
includes those whales breeding and foraging in tropical waters year-
round along the coast of Oman (Bettridge et al., 2015). Historical 
records, sparse sightings and acoustic recordings, and one satellite 
tagged whale, along the coasts of Pakistan and India indicate that the 
Arabian Sea DPS range may also include these areas. Based on the small 
population size and the extremely rare occurrence of humpback whales 
along the coasts of Pakistan and India, take of the Arabian Sea DPS of 
humpback whales is not considered a reasonable likelihood; therefore, 
this species is not addressed further in this document.
    None of the marine mammal species which the U.S. Fish and Wildlife 
Service (USFWS) is responsible for managing occur in geographic areas 
that would overlap with the SURTASS LFA sonar Study Area. Therefore, 
the Navy has determined that SURTASS LFA sonar activities would have no 
effect on the endangered or threatened species or the critical habitat 
of the ESA-listed species under the jurisdiction of the USFWS. These 
species are not considered further in this notice.
    To accurately assess the potential effects of SURTASS LFA sonar 
activities, the Navy modeled 15 representative sites in the SURTASS LFA 
sonar activity area. Tables 2 through 16 (below) summarize the 
abundance, status under the ESA, and density estimates of the marine 
mammal species and stocks that have confirmed or possible occurrence 
within the 15 SURTASS LFA sonar modeling areas in the central and 
western North Pacific Ocean and eastern Indian Ocean. Information on 
how the density and abundance stock estimates were derived for the 
selected mission sites is described in Appendix D of the 2019 SURTASS 
FSEIS/SOEIS and references for the abundances and densities described 
are provided in Tables 2 through 16.

     Table 2--Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated With Model Area 1, East of Japan
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Density (animals/Km \2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale....................  WNP.............        9,250  Tillman, 1977...    0.00001    0.00001  .........    0.00001  Tillman, 1997;          EN
                                                                                                                              Ferguson and
                                                                                                                              Barlow 2001;
                                                                                                                              2003; LGL, 2008.
Bryde's whale.................  WNP.............       20,501  IWC, 2009.......     0.0006     0.0006     0.0006     0.0006  Ohsumi, 1977....        NL
Common minke whale............  WNP OE..........       25,049  Buckland et al.,     0.0022     0.0022     0.0022     0.0022  Buckland et al.,        NL
                                                                1992.                                                         1992.
Fin whale.....................  WNP.............        9,250  Tillman, 1977;    .........  .........     0.0002     0.0002  Tillman, 1977...        EN
                                                                Mizroch et al.,
                                                                2009.
Humpback whale................  WNP stock and           1,328  Bettridge et      .........  .........    0.00036    0.00036  Calambokidis et         EN
                                 DPS.                           al., 2015.                                                    al., 2008; LGL,
                                                                                                                              2008.
North Pacific right whale.....  WNP.............          922  Best et al.,        0.00001    0.00001  .........  .........  Unavail.........        EN
                                                                2001.
Sei whale.....................  NP..............        7,000  Mizroch et al.,     0.00029    0.00029    0.00029    0.00029  Fulling et al.,         EN
                                                                2015.                                                         2011.
Baird's beaked whale..........  WNP.............        5,688  Miyashita 1986    .........  .........     0.0029     0.0029  Kasuya, 1986....        NL
                                                                and 1990;
                                                                Kasuya and
                                                                Perrin, 2017.
Common dolphin................  WNP.............    3,286,163  Ferguson and         0.0761     0.0761     0.0761     0.0761  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Common bottlenose dolphin.....  WNP Northern          100,281  Miyashita, 1993;     0.0171     0.0171     0.0171     0.0171  Miyashita, 1993.        NL
                                 Offshore.                      Kasuya and
                                                                Perrin, 2017.
Cuvier's beaked whale.........  WNP.............       90,725  Ferguson and         0.0031     0.0031     0.0031     0.0031  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Dall's porpoise (truei).......  WNP truei.......      178,157  Miyashita, 2007;     0.0390     0.0520  .........     0.0520  Ferguson and            NL
                                                                Kasuya and                                                    Barlow, 2001;
                                                                Perrin, 2017.                                                 2003.
False killer whale............  WNP.............       16,668  Miyashita, 1993.     0.0036     0.0036     0.0036     0.0036  Miyashita, 1993.        NL
Ginkgo-toothed beaked whale...  NP..............       22,799  Ferguson and         0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Harbor porpoise...............  WNP.............       31,046  Hobbs and Waite,     0.0190     0.0190     0.0190     0.0190  Hobbs and Waite,        NL
                                                                2010; Allen and                                               2010.
                                                                Angliss, 2014.
Hubbs beaked whale............  NP..............       22,799  Ferguson and         0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Killer whale..................  WNP.............       12,256  Ferguson and         0.0001     0.0001     0.0001     0.0001  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Kogia spp. \4\................  WNP.............      350,553  Ferguson and         0.0031     0.0031     0.0031     0.0031  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Pacific white-sided dolphin...  NP..............      931,000  Buckland et al.,     0.0082     0.0082     0.0082     0.0082  Ferguson and            NL
                                                                1993.                                                         Barlow, 2001;
                                                                                                                              2003.
Pantropical spotted dolphin...  WNP.............      130,002  Kanaji et al.,    .........  .........     0.0259     0.0259  Miyashita, 1993.        NL
                                                                2018.
Pygmy killer whale............  WNP.............       30,214  Ferguson and         0.0021     0.0021     0.0021     0.0021  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Risso's dolphin...............  WNP.............      143,374  Kanaji et al.,       0.0097     0.0097     0.0097     0.0097  Miyashita, 1993.        NL
                                                                2018.
Rough-toothed dolphin.........  WNP.............        5,002  Kanaji et al.,      0.00224    0.00224    0.00224    0.00224  Forney et al.,          NL
                                                                2018.                                                         2015.
Short-finned pilot whale......  WNP Northern....       20,884  Miyashita, 1993.     0.0128     0.0128     0.0128     0.0128  Miyashita, 1993.        NL

[[Page 40162]]

 
Sperm whale...................  NP..............      102,112  Kato and            0.00123    0.00123    0.00123    0.00123  Fulling et al.,         EN
                                                                Miyashita, 1998.                                              2011.
Spinner dolphin...............  WNP.............    1,015,059  Ferguson and      .........  .........    0.00083    0.00083  Barlow, 2006....        NL
                                                                Barlow, 2001;
                                                                2003.
Stejneger's beaked whale......  WNP.............        8,000  Kasuya, 1986....     0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                                                                              Barlow, 2001;
                                                                                                                              2003.
Striped dolphin...............  WNP Northern          497,725  Miyashita, 1993;     0.0111     0.0111     0.0111     0.0111  Miyashita, 1993.        NL
                                 Offshore.                      Kasuya and
                                                                Perrin, 2017.
Northern fur seal.............  WP..............      503,609  Kuzin 2015;           0.368      0.158  .........  .........  Horimoto et al.,        NL
                                                                Gelatt et al.,                                                2016.
                                                                2015.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ NP = north Pacific; OE = Offshore Japan; WP = western Pacific; WNP = western north Pacific.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.
\4\ Pygmy and dwarf sperm whales are difficult to distinguish at sea, and abundance estimates are pooled for Kogia spp as reported in Ferguson and
  Barlow, 2001 and 2003.


  Table 3--Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated With Model Area 2, North Philippine Sea
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Density (animals/Km \2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale....................  WNP.............        9,250  Tillman, 1977...    0.00001    0.00001  .........    0.00001  Tillman, 1997;          EN
                                                                                                                              Ferguson and
                                                                                                                              Barlow 2001;
                                                                                                                              2003; LGL, 2008.
Bryde's whale.................  WNP.............       20,501  IWC, 2009.......     0.0006     0.0006     0.0006     0.0006  Ohsumi, 1977....        NL
Common minke whale............  WNP OE..........       25,049  Buckland et al.,     0.0044     0.0044     0.0044     0.0044  Buckland et al.,        NL
                                                                1992.                                                         1992.
Fin whale.....................  WNP.............        9,250  Tillman, 1977;       0.0002     0.0002  .........  .........  Tillman, 1977...        EN
                                                                Mizroch et al.,
                                                                2009.
Humpback whale................  WNP and DPS.....        1,328  Bettridge et        0.00089    0.00089  .........    0.00089  Acebes et al.,          EN
                                                                al., 2015.                                                    2007; LGL, 2008.
North Pacific right whale.....  WNP.............          922  Best et al.,        0.00001    0.00001  .........  .........  Unavail.........        EN
                                                                2001.
Omura's whale.................  WNP.............        1,800  Oshsumi, 1980...    0.00004    0.00004    0.00004    0.00004  LGL, 2008; DoN,         NL
                                                                                                                              2018.
Blainville's beaked whale.....  WNP.............        8,032  Ferguson and         0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Common dolphin................  WNP.............    3,286,163  Ferguson and         0.0562     0.0562     0.0562     0.0562  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Common bottlenose dolphin.....  Japanese Coastal        3,516  Kanaji et al.,       0.0146     0.0146     0.0146     0.0146  Miyashita, 1993.        NL
                                                                2018.
Cuvier's beaked whale.........  WNP.............       90,725  Ferguson and         0.0054     0.0054     0.0054     0.0054  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
False killer whale............  WNP.............       16,668  Miyashita, 1993.     0.0029     0.0029     0.0029     0.0029  Miyashita, 1993.        NL
Fraser's dolphin..............  WNP.............      220,789  Ferguson and         0.0069     0.0069     0.0069     0.0069  Bradford et al.,        NL
                                                                Barlow, 2001;                                                 2013.
                                                                2003.
Ginkgo-toothed beaked whale...  NP..............       22,799  Ferguson and         0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Killer whale..................  WNP.............       12,256  Ferguson and        0.00009    0.00009    0.00009    0.00009  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Kogia spp.\4\.................  WNP.............      350,553  Ferguson and         0.0031     0.0031     0.0031     0.0031  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Longman's beaked whale........  WNP.............        7,619  Bradford et al.,    0.00025    0.00025    0.00025    0.00025  LGL, 2011.......        NL
                                                                2017.
Melon-headed whale............  WNP.............       56,213  Kanaji et al.,      0.00428    0.00428    0.00428    0.00428  Fulling et al.,         NL
                                                                2018.                                                         2011.
Pacific white-sided dolphin...  NP..............      931,000  Buckland et al.,     0.0119     0.0119  .........  .........  Ferguson and            NL
                                                                1993.                                                         Barlow, 2001;
                                                                                                                              2003.
Pantropical spotted dolphin...  WNP.............      130,002  Kanaji et al.,       0.0137     0.0137     0.0137     0.0137  Miyashita, 1993.        NL
                                                                2018.
Pygmy killer whale............  WNP.............       30,214  Ferguson and         0.0021     0.0021     0.0021     0.0021  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Risso's dolphin...............  WNP.............      143,374  Kanaji et al.,       0.0106     0.0106     0.0106     0.0106  Miyashita, 1993.        NL
                                                                2018.
Rough-toothed dolphin.........  WNP.............        5,002  Kanaji et al.,      0.00224    0.00224    0.00224    0.00224  Forney et al.,          NL
                                                                2018.                                                         2015.
Short-finned pilot whale......  WNP Southern....       31,396  Kanaji et al.,       0.0153     0.0153     0.0153     0.0153  Miyashita, 1993.        NL
                                                                2018.
Sperm whale...................  NP..............      102,112  Kato and            0.00123    0.00123    0.00123    0.00123  Fulling et al.,         EN
                                                                Miyashita, 1998.                                              2011.
Spinner dolphin...............  WNP.............    1,015,059  Ferguson and        0.00083    0.00083    0.00083    0.00083  Barlow, 2006....        NL
                                                                Barlow, 2001;
                                                                2003.
Striped dolphin...............  Japanese Coastal       19,631  Miyashita, 1993;     0.0329     0.0329     0.0329     0.0329  Miyashita, 1993.        NL
                                                                Kasuya and
                                                                Perrin, 2017.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ NP = north Pacific; OE = Offshore Japan; WNP = western north Pacific.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.
\4\ Pygmy and dwarf sperm whales are difficult to distinguish at sea, and abundance estimates are pooled for Kogia spp as reported in Ferguson and
  Barlow, 2001 and 2003.


  Table 4-- Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated with Model Area 3, West Philippine Sea
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Density (animals/Km \2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale....................  WNP.............        9,250  Tillman, 1997...    0.00001    0.00001  .........    0.00001  Tillman, 1997;          EN
                                                                                                                              Ferguson and
                                                                                                                              Barlow 2001;
                                                                                                                              2003; LGL, 2008.
Bryde's whale.................  WNP.............       20,501  IWC, 2009.......     0.0006     0.0006     0.0006     0.0006  Ohsumi, 1977....        NL
Common minke whale............  WNP OE..........       25,049  Buckland et al.,     0.0033     0.0033     0.0033     0.0033  Buckland et al.,        NL
                                                                1992.                                                         1992.
Fin whale.....................  WNP.............        9,250  Tillman, 1977;       0.0002     0.0002  .........  .........  Tillman, 1977...        EN
                                                                Mizroch et al.,
                                                                2009.
Humpback whale................  WNP and DPS.....        1,328  Bettridge et        0.00089    0.00089  .........    0.00089  Acebes et al.,          EN
                                                                al., 2015.                                                    2007; LGL, 2008.

[[Page 40163]]

 
Omura's whale.................  WNP.............        1,800  Oshsumi, 1980...    0.00004    0.00004    0.00004    0.00004  LGL, 2008; DoN,         NL
                                                                                                                              2018.
Blainville`s beaked whale.....  WNP.............        8,032  Ferguson and         0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Common dolphin................  WNP.............    3,286,163  Ferguson and         0.1158     0.1158     0.1158     0.1158  Carretta et al.,        NL
                                                                Barlow, 2001;                                                 2011.
                                                                2003.
Common bottlenose dolphin.....  WNP Southern           40,769  Kanaji et al.,       0.0146     0.0146     0.0146     0.0146  Miyashita, 1993.        NL
                                 Offshore.                      2018.
Cuvier's beaked whale.........  WNP.............       90,725  Ferguson and         0.0003     0.0003     0.0003     0.0003  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Deraniyagala's beaked whale...  NP..............       22,799  Ferguson and         0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
False killer whale............  WNP.............       16,668  Miyashita, 1993.     0.0029     0.0029     0.0029     0.0029  Miyashita, 1993.        NL
Fraser's dolphin..............  WNP.............      220,789  Ferguson and         0.0069     0.0069     0.0069     0.0069  Bradford et al.,        NL
                                                                Barlow, 2001;                                                 2013.
                                                                2003.
Ginkgo-toothed beaked whale...  NP..............       22,799  Ferguson and         0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Killer whale..................  WNP.............       12,256  Ferguson and        0.00009    0.00009    0.00009    0.00009  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Kogia spp.\4\.................  WNP.............      350,553  Ferguson and         0.0017     0.0017     0.0017     0.0017  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Longman's beaked whale........  WNP.............        7,619  Bradford et al.,    0.00025    0.00025    0.00025    0.00025  LGL, 2011.......        NL
                                                                2017.
Melon-headed whale............  WNP.............       56,213  Kanaji et al.,      0.00428    0.00428    0.00428    0.00428  Fulling et al.,         NL
                                                                2018.                                                         2011.
Pantropical spotted dolphin...  WNP.............      130,002  Kanaji et al.,       0.0137     0.0137     0.0137     0.0137  Miyashita, 1993.        NL
                                                                2018.
Pygmy killer whale............  WNP.............       30,214  Ferguson and         0.0021     0.0021     0.0021     0.0021  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Risso's dolphin...............  WNP.............      143,374  Kanaji et al.,       0.0106     0.0106     0.0106     0.0106  Miyashita, 1993.        NL
                                                                2018.
Rough-toothed dolphin.........  WNP.............        5,002  Kanaji et al.,      0.00224    0.00224    0.00224    0.00224  Forney et al.,          NL
                                                                2018.                                                         2015.
Short-finned pilot whale......  WNP Southern....       31,396  Kanaji et al.,       0.0076     0.0076     0.0076     0.0076  Miyashita, 1993.        NL
                                                                2018.
Sperm whale...................  NP..............      102,112  Kato and            0.00123    0.00123    0.00123    0.00123  Fulling et al.,         EN
                                                                Miyashita, 1998.                                              2011.
Spinner dolphin...............  WNP.............    1,015,059  Ferguson and        0.00083    0.00083    0.00083    0.00083  Barlow, 2006....        NL
                                                                Barlow, 2001;
                                                                2003.
Striped dolphin...............  WNP Southern           52,682  Miyashita, 1993;     0.0164     0.0164     0.0164     0.0164  Miyashita, 1993.        NL
                                 Offshore.                      Kasuya and
                                                                Perrin, 2017.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ NP = north Pacific; OE = Offshore Japan; WNP = western north Pacific.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.
\4\ Pygmy and dwarf sperm whales are difficult to distinguish at sea, and abundance estimates are pooled for Kogia spp as reported in Ferguson and
  Barlow, 2001 and 2003.


     Table 5--Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated With Model Area 4, Offshore Guam
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Density  (animals/Km\2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale....................  WNP.............        9,250  Tillman, 1977...    0.00005    0.00005  .........    0.00005  Bradford et al.,        EN
                                                                                                                              2017.
Bryde's whale.................  WNP.............       20,501  IWC, 2009.......     0.0004     0.0004     0.0004     0.0004  Fulling et al.,         NL
                                                                                                                              2011.
Common minke whale............  WNP ``OE''......       25,049  Buckland et al.,     0.0003     0.0003     0.0003     0.0003  Ferguson and            NL
                                                                1992.                                                         Barlow, 2001;
                                                                                                                              2003.
Fin whale.....................  WNP.............        9,250  Tillman, 1977;      0.00006    0.00006  .........    0.00006  Bradford et al.,        EN
                                                                Mizroch et al.,                                               2017.
                                                                2009.
Humpback whale................  WNP and DPS.....        1,328  Bettridge et        0.00089    0.00089  .........    0.00089  Acebes et al.,          EN
                                                                al., 2015.                                                    2007; LGL, 2008.
Omura's whale.................  WNP.............        1,800  Oshsumi, 1980...    0.00004    0.00004    0.00004    0.00004  LGL, 2008; DoN,         NL
                                                                                                                              2018.
Sei whale.....................  NP..............        7,000  Mizroch et al.,     0.00029    0.00029  .........    0.00029  Fulling et al.,         EN
                                                                2015.                                                         2011.
Blainville's beaked whale.....  WNP.............        8,032  Ferguson and        0.00086    0.00086    0.00086    0.00086  Bradford et al.,        NL
                                                                Barlow, 2001;                                                 2017.
                                                                2003.
Common bottlenose dolphin.....  WNP Southern           40,769  Kanaji et al.,      0.00899    0.00899    0.00899    0.00899  Bradford et al.,        NL
                                 Offshore.                      2018.                                                         2017.
Cuvier's beaked whale.........  WNP.............       90,725  Ferguson and         0.0003     0.0003     0.0003     0.0003  Bradford et al.,        NL
                                                                Barlow, 2001;                                                 2017.
                                                                2003.
Deraniyagala's beaked whale...  NP..............       22,799  Ferguson and        0.00189    0.00189    0.00189    0.00189  Bradford et al.,        NL
                                                                Barlow, 2001;                                                 2017.
                                                                2003.
Dwarf sperm whale.............  WNP.............      350,553  Ferguson and        0.00714    0.00714    0.00714    0.00714  Barlow, 2006....        NL
                                                                Barlow, 2001;
                                                                2003.
False killer whale............  WNP.............       16,668  Miyashita, 1993.    0.00111    0.00111    0.00111    0.00111  Fulling et al.,         NL
                                                                                                                              2011.
Fraser's dolphin..............  CNP.............       16,992  Bradford et al.,    0.02104    0.02104    0.02104    0.02104  Bradford et al.,        NL
                                                                2013.                                                         2017.
Ginkgo-toothed beaked whale...  NP..............       22,799  Ferguson and        0.00189    0.00189    0.00189    0.00189  Bradford et al.,        NL
                                                                Barlow, 2001;                                                 2017.
                                                                2003.
Killer whale..................  WNP.............       12,256  Ferguson and        0.00006    0.00006    0.00006    0.00006  Bradford et al.,        NL
                                                                Barlow, 2001;                                                 2017.
                                                                2003.
Longman's beaked whale........  WNP.............        7,619  Bradford et al.,    0.00311    0.00311    0.00311    0.00311  Bradford et al.,        NL
                                                                2017.                                                         2017.
Melon-headed whale............  WNP.............       56,213  Kanaji et al.,      0.00428    0.00428    0.00428    0.00428  Fulling et al.,         NL
                                                                2018.                                                         2011.
Pantropical spotted dolphin...  WNP.............      130,002  Kanaji et al.,       0.0226     0.0226     0.0226     0.0226  Fulling et al.,         NL
                                                                2018.                                                         2011.
Pygmy killer whale............  WNP.............       30,214  Ferguson and        0.00014    0.00014    0.00014    0.00014  Fulling et al.,         NL
                                                                Barlow, 2001;                                                 2011.
                                                                2003.
Pygmy sperm whale.............  WNP.............      350,553  Ferguson and        0.00291    0.00291    0.00291    0.00291  Barlow, 2006....        NL
                                                                Barlow, 2001;
                                                                2003.
Risso's dolphin...............  WNP.............      143,374  Kanaji et al.,      0.00474    0.00474    0.00474    0.00474  Bradford et al.,        NL
                                                                2018.                                                         2017.
Rough-toothed dolphin.........  WNP.............        5,002  Kanaji et al.,      0.00185    0.00185    0.00185    0.00185  LGL, 2011.......        NL
                                                                2018.
Short-finned pilot whale......  WNP Southern....       31,396  Kanaji et al.,      0.00797    0.00797    0.00797    0.00797  Bradford et al.,        NL
                                                                2018.                                                         2017.
Sperm whale...................  NP..............      102,112  Kato and            0.00123    0.00123    0.00123    0.00123  Fulling et al.,         EN
                                                                Miyashita, 1998.                                              2011.
Spinner dolphin...............  WNP.............    1,015,059  Ferguson and        0.00083    0.00083    0.00083    0.00083  Barlow, 2006....        NL
                                                                Barlow, 2001;
                                                                2003.

[[Page 40164]]

 
Striped dolphin...............  WNP Southern           52,682  Mayashita, 1993;    0.00616    0.00616    0.00616    0.00616  Fulling et al.,         NL
                                 Offshore.                      Kasuya and                                                    2011.
                                                                Perrin, 2017.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ CNP = central north Pacific; NP = north Pacific; OE = Offshore Japan; WNP = western north Pacific.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.


      Table 6--Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated With Model Area 5, Sea of Japan
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Density  (animals/Km\2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bryde's whale.................  WNP.............       20,501  IWC, 2009.......     0.0001     0.0001     0.0001     0.0001  Ferguson and            NL
                                                                                                                              Barlow, 2001;
                                                                                                                              2003.
Common minke whale............  WNP JW Stock....        2,611  Miyashita and       0.00016    0.00016    0.00016    0.00016  Ferguson and            NL
                                                                Okamura, 2011.                                                Barlow, 2001;
                                                                                                                              2003.
Fin whale.....................  WNP.............        9,250  Tillman, 1977;       0.0009     0.0009  .........     0.0009  Ferguson and            EN
                                                                Mizroch et al.,                                               Barlow, 2001;
                                                                2009.                                                         2003.
North Pacific right whale.....  WNP.............          922  Best et al.,        0.00001    0.00001  .........  .........  Unavail.........        EN
                                                                2001.
Omura's whale.................  WNP.............        1,800  Oshsumi, 1980...    0.00004    0.00004    0.00004    0.00004  LGL, 2008; DoN,         NL
                                                                                                                              2018.
Western North Pacific gray      WNP Western DPS.          290  Caretta et al.,     0.00001    0.00001    0.00001    0.00001  Unavail.........    EN \4\
 whale.                                                         2019.
Baird's beaked whale..........  WNP.............        5,688  Miyashita 1986       0.0003     0.0003  .........     0.0003  Kasuya, 1986....        NL
                                                                and 1990;
                                                                Kasuya and
                                                                Perrin, 2017.
Common dolphin................  WNP.............      279,182  Carretta et al.,     0.1158     0.1158     0.1158     0.1158  Carretta et al.,        NL
                                                                2011.                                                         2011.
Common bottlenose dolphin.....  IA..............      105,138  Miyashita, 1986;    0.00077    0.00077    0.00077    0.00077  LGL, 2011.......        NL
                                                                Kishiro and
                                                                Kasuya 1993.
Cuvier's beaked whale.........  WNP.............       90,725  Ferguson and         0.0031     0.0031     0.0031     0.0031  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Dall's porpoise...............  SOJ dalli.......      173,638  IWC, 2008.......     0.0520     0.0520  .........     0.0520  Ferguson and            NL
                                                                                                                              Barlow, 2001;
                                                                                                                              2003.
False killer whale............  IA..............        9,777  Miyashita, 1986;     0.0027     0.0027     0.0027     0.0027  Ferguson and            NL
                                                                Kishiro and                                                   Barlow, 2001;
                                                                Kasuya 1993.                                                  2003.
Harbor porpoise...............  WNP.............       31,046  Hobbs and Waite,     0.0190     0.0190  .........     0.0190  Hobbs and Waite,        NL
                                                                2010; Angliss                                                 2010.
                                                                and Allen, 2014.
Killer whale..................  WNP.............       12,256  Ferguson and        0.00009    0.00009    0.00009    0.00009  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Kogia spp.\5\.................  WNP.............      350,553  Ferguson and         0.0017     0.0017     0.0017     0.0017  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Pacific white-sided dolphin...  NP..............      931,000  Buckland et al.,     0.0030     0.0030  .........  .........  Ferguson and            NL
                                                                1993.                                                         Barlow, 2001;
                                                                                                                              2003.
Risso's dolphin...............  IA..............      143,374  Kanaji et al.,       0.0073     0.0073     0.0073     0.0073  Miyashita, 1993.        NL
                                                                2018.
Rough-toothed dolphin.........  WNP.............        5,002  Kanaji et al.,      0.00224    0.00224    0.00224    0.00224  Forney et al.,          NL
                                                                2018.                                                         2015.
Sperm whale...................  NP..............      102,112  Kato and            0.00123    0.00123    0.00123    0.00123  Fulling et al.,         EN
                                                                Miyashita, 1998.                                              2011.
Spinner dolphin...............  WNP.............    1,015,059  Ferguson and      .........  .........    0.00083    0.00083  Barlow, 2006....        NL
                                                                Barlow, 2001;
                                                                2003.
Stejneger's beaked whale......  WNP.............        8,000  Kasuya, 1986....     0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                                                                              Barlow, 2001;
                                                                                                                              2003.
Northern fur seal.............  WP..............      503,609  Kuzin 2015;           0.368      0.158  .........  .........  Horimoto et al.,        NL
                                                                Gelatt et al.,                                                2016.
                                                                2015.
Spotted seal..................  Southern and DPS        6,284  Trukhin 2019,       0.00001    0.00001    0.00001    0.00001  Unavail.........         T
                                                                Han et al.,
                                                                2010; Han et
                                                                al., 2005, Yan
                                                                et al., 2018,
                                                                Shibuya and
                                                                Kobayashi 2016.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ IA = Inshore Archipelago; JW = Sea of Japan (minke); NP = north Pacific; SOJ = Sea of Japan; WNP = western north Pacific.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.
\4\ Only the western Pacific population of gray whale is endangered under the ESA.
\5\ Pygmy and dwarf sperm whales are difficult to distinguish at sea, and abundance estimates are pooled for Kogia spp as reported in Ferguson and
  Barlow, 2001 and 2003.


     Table 7--Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated With Model Area 6, East China Sea
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Density  (animals/km\2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bryde's whale.................  ECS.............          137  IWC, 1996.......     0.0003     0.0003     0.0003     0.0003  Bradford et al.,        NL
                                                                                                                              2013.
Common minke whale............  YS..............        4,492  Miyashita and        0.0018     0.0018     0.0018     0.0018  Buckland et al.,        NL
                                                                Okamura, 2011;                                                1992.
                                                                Hakamada and
                                                                Hatanaka, 2010.
Fin whale.....................  ECS.............          500  Tillman, 1977;       0.0002     0.0002     0.0002     0.0002  Tillman, 1977...        EN
                                                                Mizroch et al.,
                                                                2009.
North Pacific right whale.....  WNP.............          922  Best et al.,        0.00001    0.00001  .........  .........  Unavail.........        EN
                                                                2001.
Omura's whale.................  WNP.............        1,800  Oshsumi, 1980...    0.00004    0.00004    0.00004    0.00004  LGL, 2008.......        NL
Western North Pacific gray      WNP and Western           290  Carretta et al.,    0.00001    0.00001  .........    0.00001  Unavail.........    EN \4\
 whale.                          DPS.                           2019.
Blainville's beaked whale.....  WNP.............        8,032  Ferguson and         0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Common dolphin................  WNP.............      279,182  Carretta et al.,     0.1158     0.1158     0.1158     0.1158  Carretta et al.,        NL
                                                                2011.                                                         2011.
Common bottlenose dolphin.....  IA..............      105,138  Miyashita, 1986;    0.00077    0.00077    0.00077    0.00077  LGL, 2011.......        NL
                                                                Kishiro and
                                                                Kasuya 1993.

[[Page 40165]]

 
Cuvier's beaked whale.........  WNP.............       90,725  Ferguson and         0.0003     0.0003     0.0003     0.0003  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
False killer whale............  IA..............        9,777  Miyashita, 1986;    0.00111    0.00111    0.00111    0.00111  Fulling et al.,         NL
                                                                Kishiro and                                                   2011.
                                                                Kasuya 1993.
Fraser's dolphin..............  WNP.............      220,789  Ferguson and        0.00694    0.00694    0.00694    0.00694  Bradford et al.,        NL
                                                                Barlow, 2001;                                                 2013.
                                                                2003.
Ginkgo-toothed beaked whale...  NP..............       22,799  Ferguson and         0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Killer whale..................  WNP.............       12,256  Ferguson and        0.00009    0.00009    0.00009    0.00009  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Kogia spp.\5\.................  WNP.............      350,553  Ferguson and         0.0017     0.0017     0.0017     0.0017  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Longman's beaked whale........  WNP.............        7,619  Bradford et al.,    0.00025    0.00025    0.00025    0.00025  LGL, 2011.......        NL
                                                                2017.
Melon-headed whale............  WNP.............       56,213  Kanaji et al.,      0.00428    0.00428    0.00428    0.00428  Fulling et al.,         NL
                                                                2018.                                                         2011.
Pacific white-sided dolphin...  NP..............      931,000  Buckland et al.,     0.0028     0.0028  .........  .........  Ferguson and            NL
                                                                1993.                                                         Barlow, 2001;
                                                                                                                              2003.
Pantropical spotted dolphin...  WNP.............      130,002  Kanaji et al.,      0.01374    0.01374    0.01374    0.01374  Miyashita, 1993.        NL
                                                                2018.
Pygmy killer whale............  WNP.............       30,214  Ferguson and        0.00014    0.00014    0.00014    0.00014  Fulling et al.,         NL
                                                                Barlow, 2001;                                                 2011.
                                                                2003.
Risso's dolphin...............  IA..............      143,374  Kanaji et al.,       0.0106     0.0106     0.0106     0.0106  Miyashita, 1993.        NL
                                                                2018.
Rough-toothed dolphin.........  WNP.............        5,002  Kanaji et al.,      0.00224    0.00224    0.00224    0.00224  Forney et al.,          NL
                                                                2018.                                                         2015.
Sperm whale...................  NP..............      102,112  Kato and            0.00123    0.00123    0.00123    0.00123  Fulling et al.,         EN
                                                                Miyashita, 1998.                                              2011.
Spinner dolphin...............  WNP.............    1,015,059  Ferguson and        0.00083    0.00083    0.00083    0.00083  Barlow, 2006....        NL
                                                                Barlow, 2001;
                                                                2003.
Spotted seal..................  Southern and DPS        1,500  Han et al., 2005    0.00001    0.00001    0.00001    0.00001  Unavail.........         T
                                                                in Yan et al.,
                                                                2018; Han et
                                                                al., 2010.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ECS = East China Sea; IA = Inshore Archipelago; NP = north Pacific; WNP = western north Pacific; YS = Yellow Sea.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.
\4\ Only the western Pacific population of gray whale is endangered under the ESA.
\5\ Pygmy and dwarf sperm whales are difficult to distinguish at sea, and abundance estimates are pooled for Kogia spp as reported in Ferguson and
  Barlow, 2001 and 2003.


    Table 8--Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated With Model Area 7, South China Sea
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Density  (animals/km\2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bryde's whale.................  WNP.............       20,501  IWC, 2009.......     0.0006     0.0006     0.0006     0.0006  Ohsumi, 1977....        NL
Common minke whale............  YS..............        4,492  Miyashita and        0.0018     0.0018     0.0018     0.0018  Buckland et al.,        NL
                                                                Okamura, 2011;                                                1992.
                                                                Kakamada ad
                                                                Hatanaka 2010.
Fin whale.....................  WNP.............        9,250  Tillman, 1977...     0.0002     0.0002  .........     0.0002  Tillman, 1977...        EN
Humpback whale................  WNP and DPS.....        1,328  Bettridge et        0.00036    0.00036  .........    0.00036  Calambokidis et         EN
                                                                al., 2015.                                                    al., 2008; LGL,
                                                                                                                              2008.
North Pacific right whale.....  WNP.............          922  Best et al.,        0.00001    0.00001  .........  .........  Unavail.........        EN
                                                                2001.
Omura's whale.................  WNP.............        1,800  Oshsumi, 1980...    0.00004    0.00004    0.00004    0.00004  LGL, 2008; DoN,         NL
                                                                                                                              2018.
Western North Pacific gray      WNP and Western           290  Carretta et al.,    0.00001    0.00001  .........    0.00001  Unavail.........    EN \4\
 whale.                          DPS.                           2019.
Blainville's beaked whale.....  WNP.............        8,032  Ferguson and         0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Common dolphin................  WNP.............      279,182  Carretta et al.,     0.1158     0.1158     0.1158     0.1158  Carretta et al.,        NL
                                                                2011.                                                         2011.
Common bottlenose dolphin.....  IA..............      105,138  Miyashita, 1986;    0.00077    0.00077    0.00077    0.00077  LGL, 2011.......        NL
                                                                Kishiro and
                                                                Kasuya 1993.
Cuvier's beaked whale.........  WNP.............       90,725  Ferguson and         0.0003     0.0003     0.0003     0.0003  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Deraniyagala's beaked whale...  NP..............       22,799  Ferguson and         0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
False killer whale............  IA..............        9,777  Miyashita, 1986;    0.00111    0.00111    0.00111    0.00111  Fulling et al.,         NL
                                                                Kishiro and                                                   2011.
                                                                Kasuya 1993.
Fraser's dolphin..............  WNP.............      220,789  Ferguson and        0.00694    0.00694    0.00694    0.00694  Bradford et al.,        NL
                                                                Barlow, 2001;                                                 2013.
                                                                2003.
Ginkgo-toothed beaked whale...  NP..............       22,799  Ferguson and         0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Killer whale..................  WNP.............       12,256  Ferguson and        0.00009    0.00009    0.00009    0.00009  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Kogia spp.\5\.................  WNP.............      350,553  Ferguson and         0.0017     0.0017     0.0017     0.0017  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Longman's beaked whale........  WNP.............        7,619  Bradford et al.,    0.00025    0.00025    0.00025    0.00025  LGL, 2011.......        NL
                                                                2017.
Melon-headed whale............  WNP.............       56,213  Kanaji et al.,      0.00428    0.00428    0.00428    0.00428  Fulling et al.,         NL
                                                                2018.                                                         2011.
Pantropical spotted dolphin...  WNP.............      130,002  Kanaji et al.,      0.01374    0.01374    0.01374    0.01374  Miyashita, 1993.        NL
                                                                2018.
Pygmy killer whale............  WNP.............       30,214  Ferguson and        0.00014    0.00014    0.00014    0.00014  Fulling et al.,         NL
                                                                Barlow, 2001;                                                 2011.
                                                                2003.
Risso's dolphin...............  IA..............      143,374  Kanaji et al.,       0.0106     0.0106     0.0106     0.0106  Miyashita, 1993.        NL
                                                                2018.
Rough-toothed dolphin.........  WNP.............        5,002  Kanaji et al.,      0.00224    0.00224    0.00224    0.00224  Forney et al.,          NL
                                                                2018.                                                         2015.
Short-finned pilot whale......  WNP Southern....       31,396  Kanaji et al.,      0.00159    0.00159    0.00159    0.00159  Fulling et al.,         NL
                                                                2018.                                                         2011.
Sperm whale...................  NP..............      102,112  Kato and            0.00123    0.00123    0.00123    0.00123  Fulling et al.,         EN
                                                                Miyashita, 1998.                                              2011.
Spinner dolphin...............  WNP.............    1,015,059  Ferguson and        0.00083    0.00083    0.00083    0.00083  Barlow, 2006....        NL
                                                                Barlow, 2001;
                                                                2003.
Striped dolphin...............  WNP Southern           52,682  Miyashita, 1993;    0.00584    0.00584    0.00584    0.00584  LGL, 2011.......        NL
                                 Offshore.                      Kasuya and
                                                                Perrin, 2017.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ IA = Inshore Archipelago; NP = north Pacific; WNP = western north Pacific; YS = Yellow Sea.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.

[[Page 40166]]

 
\4\ Only the western Pacific population of gray whale is endangered under the ESA.
\5\ Pygmy and dwarf sperm whales are difficult to distinguish at sea, and abundance estimates are pooled for Kogia spp as reported in Ferguson and
  Barlow, 2001 and 2003.


 Table 9--Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated With Model Area 8, Offshore Japan 25[deg]
                                                                      to 40[deg] N
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Density  (animals/km\2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale....................  WNP.............        9,250  Tillman, 1977...    0.00001    0.00001  .........    0.00001  Tillman, 1997;          EN
                                                                                                                              Ferguson and
                                                                                                                              Barlow 2001;
                                                                                                                              2003; LGL, 2008.
Bryde's whale.................  WNP.............       20,501  IWC, 2009.......     0.0003     0.0003     0.0003     0.0003  LGL, 2011.......        NL
Common minke whale............  WNP ``OE''......       25,049  Buckland et al.,     0.0003     0.0003     0.0003     0.0003  Buckland et al.,        NL
                                                                1992.                                                         1992.
Fin whale.....................  WNP.............        9,250  Tillman, 1977;    .........  .........     0.0001     0.0001  Tillman, 1977...        EN
                                                                Mizroch et al.,
                                                                2009.
Humpback whale................  WNP and DPS.....        1,328  Bettridge et      .........  .........    0.00036    0.00036  Calambokidis et         EN
                                                                al., 2015.                                                    al., 2008; LGL,
                                                                                                                              2008.
Sei whale.....................  NP..............        7,000  Mizroch et al.,   .........    0.00029    0.00029    0.00029  Fulling et al.,         EN
                                                                2015.                                                         2011.
Baird's beaked whale..........  WNP.............        5,688  Miyashita, 1986;     0.0001     0.0001     0.0001     0.0001  Kasuya, 1986....        NL
                                                                Kasuya and
                                                                Perrin, 2017.
Blainville's beaked whale.....  WNP.............        8,032  Ferguson and         0.0007     0.0007     0.0007     0.0007  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Common dolphin................  WNP.............    3,286,163  Ferguson and         0.0863     0.0863     0.0863     0.0863  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Common bottlenose dolphin.....  WNP Northern          100,281  Miyashita, 1993;    0.00077    0.00077    0.00077    0.00077  LGL, 2011.......        NL
                                 Offshore.                      Kasuya and
                                                                Perrin, 2017.
Cuvier's beaked whale.........  WNP.............       90,725  Ferguson and        0.00374    0.00374    0.00374    0.00374  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Dall's porpoise...............  WNP dalli.......      162,000  Miyashita, 1991;     0.0390     0.0520  .........     0.0520  Ferguson and            NL
                                                                Kasuya and                                                    Barlow, 2001;
                                                                Perrin, 2017.                                                 2003.
Dwarf sperm whale.............  WNP.............      350,553  Ferguson and         0.0043     0.0043     0.0043     0.0043  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
False killer whale............  WNP.............       16,668  Miyashita, 1993.     0.0036     0.0036     0.0036     0.0036  Miyashita, 1993.        NL
Hubb's beaked whale...........  NP..............       22,799  Ferguson and         0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Killer whale..................  WNP.............       12,256  Ferguson and        0.00009    0.00009    0.00009    0.00009  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Longman's beaked whale........  WNP.............        7,619  Bradford et al.,    0.00025    0.00025    0.00025    0.00025  LGL, 2011.......        NL
                                                                2017.
Melon-headed whale............  WNP.............       56,213  Kanaji et al.,       0.0027     0.0027     0.0027     0.0027  LGL, 2011.......        NL
                                                                2018.
Mesoplodon spp.\4\............  WNP.............       22,799  Ferguson and         0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Northern right whale dolphin..  NP..............       68,000  Buckland et al.,    0.00001    0.00001  .........    0.00001  Unavail.........        NL
                                                                1993.
Pacific white-sided dolphin...  NP..............      931,000  Buckland et al.,     0.0048     0.0048     0.0048     0.0048  Ferguson and            NL
                                                                1993.                                                         Barlow, 2001;
                                                                                                                              2003.
Pantropical spotted dolphin...  WNP.............      130,002  Kanaji et al.,       0.0113     0.0113     0.0113     0.0113  LGL, 2011.......        NL
                                                                2018.
Pygmy killer whale............  WNP.............       30,214  Ferguson and         0.0001     0.0001     0.0001     0.0001  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Pygmy sperm whale.............  WNP.............      350,553  Ferguson and         0.0018     0.0018     0.0018     0.0018  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Risso's dolphin...............  WNP.............      143,374  Kanaji et al.,       0.0005     0.0005     0.0005     0.0005  LGL, 2011.......        NL
                                                                2018.
Rough-toothed dolphin.........  WNP.............        5,002  Kanaji et al.,       0.0019     0.0019     0.0019     0.0019  LGL, 2011.......        NL
                                                                2018.
Short-finned pilot whale......  WNP Northern....       20,884  Miyashita, 1993.     0.0021     0.0021     0.0021     0.0021  LGL, 2011.......        NL
Sperm whale...................  NP..............      102,112  Kato and             0.0022     0.0022     0.0022     0.0022  LGL, 2011.......        EN
                                                                Miyashita, 1998.
Spinner dolphin...............  WNP.............    1,015,059  Ferguson and         0.0019     0.0019     0.0019     0.0019  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Stejneger's beaked whale......  WNP.............        8,000  Kasuya, 1986....     0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                                                                              Barlow, 2001;
                                                                                                                              2003.
Striped dolphin...............  WNP Northern          497,725  Miyashita, 1993;     0.0058     0.0058     0.0058     0.0058  LGL, 2011.......        NL
                                 Offshore.                      Kasuya and
                                                                Perrin, 2017.
Hawaiian monk seal............  Hawaii..........        1,427  NMFS, 2018......    0.00001    0.00001    0.00001    0.00001  Unavail.........        EN
Northern fur seal.............  WP..............      503,609  Kuzin 2015;          0.0123  .........  .........  .........  Buckland et al.,        NL
                                                                Gelatt et al.,                                                1993.
                                                                2015.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ NP = north Pacific; OE = Offshore Japan; WNP = western north Pacific; WP = Western Pacific.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.
\4\ No methods are available to distinguish between the species of Mesoplodon beaked whales in the WNP 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., 2018). As reported in
  Ferguson and Barlow, 2001 and 2003, data on these species were pooled. These six species are managed as one unit.


Table 10--Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated With Model Area 9, Offshore Japan 10[deg]
                                                                      to 25[deg] N
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Density  (animals/Km\2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale....................  WNP.............        9,250  Tillman, 1977;      0.00001    0.00001  .........    0.00001  Tillman, 1997;          EN
                                                                Caretta et al.,                                               Ferguson and
                                                                2019.                                                         Barlow 2001;
                                                                                                                              2003; LGL, 2008.
Bryde's whale.................  WNP.............       20,501  IWC, 2009.......     0.0003     0.0003     0.0003     0.0003  LGL, 2011.......        NL
Fin whale.....................  WNP.............        9,250  Tillman, 1977...    0.00001    0.00001  .........  .........  Unavail.........        EN
Humpback whale................  WNP and DPS.....        1,328  Bettridge et        0.00036    0.00036  .........    0.00036  Calambokidis et         EN
                                                                al., 2015.                                                    al., 2008; LGL,
                                                                                                                              2008.
Omura's whale.................  WNP.............        1,800  Oshsumi, 1980...    0.00004    0.00004    0.00004    0.00004  LGL, 2008; DoN,         NL
                                                                                                                              2018.
Sei whale.....................  NP..............        7,000  Mizroch et al.,     0.00029  .........  .........    0.00029  Fulling et al.,         EN
                                                                2015.                                                         2011.
Blainville's beaked whale.....  WNP.............        8,032  Ferguson and         0.0007     0.0007     0.0007     0.0007  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Common bottlenose dolphin.....  WNP Southern           40,769  Kanaji et al.,      0.00077    0.00077    0.00077    0.00077  LGL, 2011.......        NL
                                 Offshore.                      2018.
Cuvier's beaked whale.........  WNP.............       90,725  Ferguson and        0.00374    0.00374    0.00374    0.00374  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.

[[Page 40167]]

 
Deraniyagala's beaked whale...  NP..............       22,799  Ferguson and        0.00093    0.00093    0.00093    0.00093  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Dwarf sperm whale.............  WNP.............      350,553  Ferguson and         0.0043     0.0043     0.0043     0.0043  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
False killer whale............  WNP.............       16,668  Miyashita, 1993.    0.00057    0.00057    0.00057    0.00057  LGL, 2011.......        NL
Fraser's dolphin..............  CNP.............       16,992  Bradford et al.,    0.00251    0.00251    0.00251    0.00251  LGL, 2011.......        NL
                                                                2013.
Ginkgo-toothed beaked whale...  NP..............       22,799  Ferguson and        0.00093    0.00093    0.00093    0.00093  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Killer whale..................  WNP.............       12,256  Ferguson and        0.00009    0.00009    0.00009    0.00009  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Longman's beaked whale........  WNP.............        7,619  Bradford et al.,    0.00025    0.00025    0.00025    0.00025  LGL, 2011.......        NL
                                                                2017.
Melon-headed whale............  WNP.............       56,213  Kanaji et al.,      0.00267    0.00267    0.00267    0.00267  LGL, 2011.......        NL
                                                                2018.
Pantropical spotted dolphin...  WNP.............      130,002  Kanaji et al.,      0.01132    0.01132    0.01132    0.01132  LGL, 2011.......        NL
                                                                2018.
Pygmy killer whale............  WNP.............       30,214  Ferguson and        0.00006    0.00006    0.00006    0.00006  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Pygmy sperm whale.............  WNP.............      350,553  Ferguson and        0.00176    0.00176    0.00176    0.00176  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Risso's dolphin...............  WNP.............      143,374  Kanaji et al.,      0.00046    0.00046    0.00046    0.00046  LGL, 2011.......        NL
                                                                2018.
Rough-toothed dolphin.........  WNP.............        5,002  Kanaji et al.,      0.00185    0.00185    0.00185    0.00185  LGL, 2011.......        NL
                                                                2018.
Short-finned pilot whale......  WNP Southern....       31,396  Kanaji et al.,      0.00211    0.00211    0.00211    0.00211  LGL, 2011.......        NL
                                                                2018.
Sperm whale...................  NP..............      102,112  Kato and            0.00222    0.00222    0.00222    0.00222  LGL, 2011.......        EN
                                                                Miyashita, 1998.
Spinner dolphin...............  WNP.............    1,015,059  Ferguson and        0.00187    0.00187    0.00187    0.00187  LGL, 2011.......        NL
                                                                Barlow, 2001;
                                                                2003.
Striped dolphin...............  WNP Southern           52,682  Miyashita, 1993;    0.00584    0.00584    0.00584    0.00584  LGL, 2011.......        NL
                                 Offshore.                      Kasuya and
                                                                Perrin, 2017.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ NP = north Pacific; CNP = central north Pacific; WNP = western north Pacific.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.


   Table 11--Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated With Model Area 10, Northern Hawaii
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Density  (animals/Km\2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale....................  CNP.............          133  Bradford et al.,    0.00005    0.00005  .........    0.00005  Bradford et al.,        EN
                                                                2017.                                                         2017.
Bryde's whale.................  Hawaii..........        1,751  Bradford et al.,   0.000085   0.000085   0.000085   0.000085  Forney et al.,          NL
                                                                2017.                                                         2015.
Common minke whale............  Hawaii..........       25,049  Buckland et al.,    0.00423    0.00423  .........    0.00423  Martin et al.,          NL
                                                                1992.                                                         2015.
Fin whale.....................  Hawaii..........          154  Bradford et al.,    0.00006    0.00006  .........    0.00006  Bradford et al.,        EN
                                                                2017.                                                         2017.
Humpback whale................  CNP and Hawaii         10,103  Calambokidis et     0.00529    0.00529  .........    0.00529  Mobley et al.,          NL
                                 DPS.                           al., 2008; Muto                                               2001;
                                                                et al., 2019.                                                 Calambokidis et
                                                                                                                              al., 2008.
Sei whale.....................  Hawaii..........          391  Bradford et al.,    0.00016    0.00016  .........    0.00016  Bradford et al.,        EN
                                                                2017.                                                         2017.
Blainville's beaked whale.....  Hawaii..........        2,105  Bradford et al.,    0.00086    0.00086    0.00086    0.00086  Bradford et al.,        NL
                                                                2017.                                                         2017.
Common bottlenose dolphin.....  Hawaii pelagic..       21,815  Bradford et al.,    0.00118    0.00118    0.00118    0.00118  Forney et al.,          NL
                                                                2017.                                                         2015.
                                Kauai/Niihau....          184  Baird et al.,         0.065      0.065      0.065      0.065  Baird et al.,           NL
                                                                2009; Caretta                                                 2009.
                                                                et al., 2014.
                                4 Islands.......          191  Baird et al.,         0.017      0.017      0.017      0.017  Baird et al.,           NL
                                                                2009; Caretta                                                 2009.
                                                                et al., 2014.
                                Oahu............          743  Baird et al.,         0.187      0.187      0.187      0.187  Baird et al.,           NL
                                                                2009; Caretta                                                 2009.
                                                                et al., 2014.
                                Hawaii Island...          128  Baird et al.,         0.028      0.028      0.028      0.028  Baird et al.,           NL
                                                                2009; Caretta                                                 2009.
                                                                et al., 2014.
Cuvier's beaked whale.........  Hawaii..........          723  Bradford et al.,     0.0003     0.0003     0.0003     0.0003  Bradford et al.,        NL
                                                                2017.                                                         2017.
Dwarf sperm whale.............  Hawaii..........       17,519  Barlow, 2006....    0.00714    0.00714    0.00714    0.00714  Barlow, 2006....        NL
False killer whale............  Hawaii-Pelagic..        1,540  Bradford et al.,     0.0006     0.0006     0.0006     0.0006  Forney et al.,          NL
                                                                2014; 2015;                                                   2015; Bradford
                                                                Caretta et al.,                                               et al., 2015.
                                                                2019.
                                Main Hawaiian             167  Bradford et al.,     0.0008     0.0008     0.0008     0.0008  Bradford et al.,        EN
                                 Islands Insular                2018; Caretta                                                 2015.
                                 and DPS.                       et al., 2019.
                                Northwest                 617  Bradford et al.,     0.0006     0.0006     0.0006     0.0006  Forney et al.,          NL
                                 Hawaiian                       2014; 2015;                                                   2015; Bradford
                                 Islands.                       Caretta et al.,                                               et al., 2015.
                                                                2019.
Fraser's dolphin..............  Hawaii..........       51,491  Bradford et al.,    0.02104    0.02104    0.02104    0.02104  Bradford et al.,        NL
                                                                2017.                                                         2017.
Killer whale..................  Hawaii..........          146  Bradford et al.,    0.00006    0.00006    0.00006    0.00006  Bradford et al.,        NL
                                                                2017.                                                         2017.
Longman's beaked whale........  Hawaii..........        7,619  Bradford et al.,    0.00311    0.00311    0.00311    0.00311  Bradford et al.,        NL
                                                                2017.                                                         2017.
Melon-headed whale............  Hawaiian Islands        8,666  Bradford et al.,      0.002     0.0020     0.0020     0.0020  Aschettino, 2010        NL
                                                                2017.
                                Kohala Resident.          447  Aschettino, 2010     0.1000     0.1000     0.1000     0.1000  Aschettino, 2010        NL
Pantropical spotted dolphin...  Hawaii Pelagic..       55,795  Bradford et al.,    0.00369    0.00369    0.00369    0.00369  Forney et al.,          NL
                                                                2017.                                                         2015.
                                Hawaii Island...          220  Courbis et al.,       0.061      0.061      0.061      0.061  Oleson et al.,          NL
                                                                2014.                                                         2013.
                                Oahu............          220  Courbis et al.,       0.072      0.072      0.072      0.072  Oleson et al.,          NL
                                                                2014.                                                         2013.
                                4 Islands.......          220  Courbis et al.,       0.061      0.061      0.061      0.061  Oleson et al.,          NL
                                                                2014.                                                         2013.
Pygmy killer whale............  Hawaii..........       10,640  Bradford et al.,    0.00435    0.00435    0.00435    0.00435  Bradford et al.,        NL
                                                                2017.                                                         2017.
Pygmy sperm...................  Hawaii..........        7,138  Barlow, 2006....     0.0029     0.0029     0.0029     0.0029  Barlow, 2006....        NL
Risso's dolphin...............  Hawaii..........       11,613  Bradford et al.,    0.00474    0.00474    0.00474    0.00474  Bradford et al.,        NL
                                                                2017.                                                         2017.
Rough-toothed dolphin.........  Hawaii..........       72,528  Bradford et al.,    0.00224    0.00224    0.00224    0.00224  Forney et al.,          NL
                                                                2017.                                                         2015.
Short-finned pilot whale......  Hawaii..........       19,503  Bradford et al.,    0.00459    0.00459    0.00459    0.00459  Forney et al.,          NL
                                                                2017.                                                         2015.
Sperm whale...................  Hawaii..........        4,559  Bradford et al.,    0.00158    0.00158    0.00158    0.00158  Forney et al.,          EN
                                                                2017.                                                         2015.
Spinner dolphin...............  Hawaii Pelagic..        3,351  Barlow, 2006....    0.00159    0.00159    0.00159    0.00159  Forney et al.,          NL
                                                                                                                              2015.
                                Kauai/Niihau....          601  Carretta et al.,      0.097      0.097      0.097      0.097  Hill et al.,            NL
                                                                2014.                                                         2011.
                                Hawaii Island...          665  Carretta et al.,      0.066      0.066      0.066      0.066  Tyne et al.,            NL
                                                                2019.                                                         2014.
                                Oahu/4 Islands..          355  Carretta et al.,      0.023      0.023      0.023      0.023  Hill et al.,            NL
                                                                2014.                                                         2011.
                                Kure/Midway               260  Carretta et al.,     0.0070     0.0070     0.0070     0.0070  Barlow, 2006....        NL
                                 Atoll.                         2014.
                                Pearl and Hermes          300  Karczmarski et       0.0070     0.0070     0.0070     0.0070  Barlow, 2006....        NL
                                 Reef.                          al., 2005.
Striped dolphin...............  Hawaii..........       61,201  Bradford et al.,    0.00385    0.00385    0.00385    0.00385  Forney et al.,          NL
                                                                2017.                                                         2015.

[[Page 40168]]

 
Hawaiian monk seal............  Hawaii..........        1,427  NMFS, 2018......    0.00004    0.00004    0.00004    0.00004  NMFS, 2018; DoN,        EN
                                                                                                                              2018.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ CNP = central north Pacific.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.


   Table 12--Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated With Model Area 11, Southern Hawaii
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Density  (animals/Km\2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale....................  CNP.............          133  Bradford et al.,    0.00005    0.00005  .........    0.00005  Bradford et al.,        EN
                                                                2017.                                                         2017.
Bryde's whale.................  Hawaii..........          798  Bradford et al.,    0.00012    0.00012    0.00012    0.00012  Forney et al.,          NL
                                                                2013.                                                         2015.
Common minke whale............  Hawaii..........       25,049  Buckland et al.,    0.00423    0.00423  .........    0.00423  Martin et al.,          NL
                                                                1992.                                                         2015.
Fin whale.....................  Hawaii..........          154  Bradford et al.,    0.00006    0.00006  .........    0.00006  Bradford et al.,        EN
                                                                2017.                                                         2017.
Humpback whale................  CNP/Hawaii DPS..       10,103  Calambokidis et     0.00631    0.00631  .........    0.00631  Mobley et al.,          NL
                                                                al., 2008.                                                    2001;
                                                                                                                              Calambokidis et
                                                                                                                              al., 2008.
Sei whale.....................  Hawaii..........          391  Bradford et al.,    0.00016    0.00016  .........    0.00016  Bradford et al.,        EN
                                                                2017.                                                         2017.
Blainville's beaked whale.....  Hawaii..........        2,105  Bradford et al.,    0.00086    0.00086    0.00086    0.00086  Bradford et al.,        NL
                                                                2017.                                                         2017.
Common bottlenose dolphin.....  Hawaii Pelagic..       21,815  Bradford et al.,    0.00126    0.00126    0.00126    0.00126  Forney et al.,          NL
                                                                2017.                                                         2015.
                                Oahu............          743  Baird et al.,         0.187      0.187      0.187      0.187  Baird et al.,           NL
                                                                2009; Carretta                                                2009.
                                                                et al., 2014.
                                4 Islands.......          191  Baird et al.,         0.017      0.017      0.017      0.017  Baird et al.,           NL
                                                                2009; Carretta                                                2009.
                                                                et al., 2014.
                                Hawaii Island...          128  Baird et al.,         0.028      0.028      0.028      0.028  Baird et al.,           NL
                                                                2009; Carretta                                                2009.
                                                                et al., 2014.
                                Kauai/Niihau....          184  Baird et al.,         0.065      0.065      0.065      0.065  Baird et al.,           NL
                                                                2009; Carretta                                                2009.
                                                                et al., 2014.
Cuvier's beaked whale.........  Hawaii..........          723  Bradford et al.,     0.0003     0.0003     0.0003     0.0003  Bradford et al.,        NL
                                                                2017.                                                         2017.
Deraniyagala's beaked whale...  NP..............       22,799  Ferguson and        0.00093    0.00093    0.00093    0.00093  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Dwarf sperm whale.............  Hawaii..........       17,519  Barlow, 2006....    0.00714    0.00714    0.00714    0.00714  Barlow, 2006....        NL
False killer whale............  Hawaii-Pelagic..        1,540  Bradford et al.,    0.00086    0.00086    0.00086    0.00086  Forney et al.,          NL
                                                                2014; 2015.                                                   2015; Bradford
                                                                                                                              et al., 2015.
                                Main Hawaiian             167  Bradford et al.,     0.0008     0.0008     0.0008     0.0008  Bradford et al.,        EN
                                 Island Insular                 2018; Carretta                                                2015.
                                 and DPS.                       et al., 2019.
Fraser's dolphin..............  Hawaii..........       51,491  Bradford et al.,    0.02104    0.02104    0.02104    0.02104  Bradford et al.,        NL
                                                                2017.                                                         2017.
Killer whale..................  Hawaii..........          146  Bradford et al.,    0.00006    0.00006    0.00006    0.00006  Bradford et al.,        NL
                                                                2017.                                                         2017.
Longman's beaked whale........  Hawaii..........        7,619  Bradford et al.,    0.00311    0.00311    0.00311    0.00311  Bradford et al.,        NL
                                                                2017.                                                         2017.
Melon-headed whale............  Hawaiian Islands        8,666  Bradford et al.,     0.0020     0.0020     0.0020     0.0020  Aschettino, 2010        NL
                                                                2017.
                                Kohala Resident.          447  Aschettino, 2010     0.1000     0.1000     0.1000     0.1000  Aschettino, 2010        NL
Pantropical spotted dolphin...  Hawaii Pelagic..       55,795  Bradford et al.,    0.00541    0.00541    0.00541    0.00541  Forney et al.,          NL
                                                                2017.                                                         2015.
                                Hawaii Island...          220  Courbis et al.,       0.061      0.061      0.061      0.061  Oleson et al.,          NL
                                                                2014.                                                         2013.
                                Oahu............          220  Courbis et al.,       0.072      0.072      0.072      0.072  Oleson et al.,          NL
                                                                2014.                                                         2013.
                                4 Islands.......          220  Courbis et al.,       0.061      0.061      0.061      0.061  Oleson et al.,          NL
                                                                2014.                                                         2013.
Pygmy killer whale............  Hawaii..........       10,640  Bradford et al.,    0.00435    0.00435    0.00435    0.00435  Bradford et al.,        NL
                                                                2017.                                                         2017.
Pygmy sperm whale.............  Hawaii..........        7,138  Barlow, 2006....     0.0029     0.0029     0.0029     0.0029  Barlow, 2006....        NL
Risso's dolphin...............  Hawaii..........       11,613  Bradford et al.,    0.00474    0.00474    0.00474    0.00474  Bradford et al.,        NL
                                                                2017.                                                         2017.
Rough toothed dolphin.........  Hawaii..........       75,528  Bradford et al.,    0.00257    0.00257    0.00257    0.00257  Forney et al.,          NL
                                                                2017.                                                         2015.
Short-finned pilot whale......  Hawaii..........       19,503  Bradford et al.,    0.00549    0.00549    0.00549    0.00549  Forney et al.,          NL
                                                                2017.                                                         2015.
Sperm whale...................  Hawaii..........        4,559  Bradford et al.,    0.00131    0.00131    0.00131    0.00131  Forney et al.,          EN
                                                                2017.                                                         2015.
Spinner dolphin...............  Hawaii Pelagic..        3,351  Barlow, 2006....    0.00348    0.00348    0.00348    0.00348  Forney et al.,          NL
                                                                                                                              2015.
                                Oahu/4-Islands..          601  Carretta et al.,      0.023      0.023      0.023      0.023  Hill et al.,            NL
                                                                2014.                                                         2011.
                                Hawaii Island...          665  Carretta et al.,      0.066      0.066      0.066      0.066  Tyne et al.,            NL
                                                                2019.                                                         2014.
                                Kauai/Niihau....          355  Carretta et al.,      0.097      0.097      0.097      0.097  Hill et al.,            NL
                                                                2014.                                                         2011.
Striped dolphin...............  Hawaii..........       61,201  Bradford et al.,    0.00475    0.00475    0.00475    0.00475  Forney et al.,          NL
                                                                2017.                                                         2015.
Hawaiian monk seal............  Hawaii..........        1,427  NMFS, 2018......    0.00004    0.00004    0.00004    0.00004  NMFS, 2018, DoN,        EN
                                                                                                                              2018.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ CNP = central north Pacific; NP = north Pacific.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.


  Table 13--Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated With Model Area 12, Offshore Sri Lanka
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                           Density (animals/km\2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale....................  NIND............        3,691  IWC, 2016.......    0.00004    0.00004    0.00004    0.00004  Kaschner et al.,        EN
                                                                                                                              2006; DoN, 2018.
Bryde's whale.................  NIND............        9,176  Wade and            0.00041    0.00041    0.00041    0.00041  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Common minke whale............  IND.............      257,000  IWC, 2016.......    0.00001    0.00001    0.00001    0.00001  SMRU Ltd., 2012;        NL
                                                                                                                              DoN, 2018.
Fin whale.....................  IND.............        1,846  IWC, 2016.......    0.00001    0.00001    0.00001    0.00001  DoN, 2018.......        EN
Omura's whale.................  NIND............        9,176  Wade and            0.00041    0.00041    0.00041    0.00041  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Sei whale.....................  NIND............        9,176  Wade and            0.00041    0.00041    0.00041    0.00041  SMRU Ltd., 2012;        EN
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Blainville's beaked whale.....  IND.............       16,867  Wade and            0.00105    0.00105    0.00105    0.00105  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Common dolphin................  IND.............    1,819,982  Wade and            0.00513    0.00516    0.00541    0.00538  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Common bottlenose dolphin.....  NIND............      785,585  Wade and            0.04839    0.04829    0.04725    0.04740  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.

[[Page 40169]]

 
Cuvier's beaked whale.........  NIND............       27,272  Wade and            0.00506    0.00508    0.00505    0.00505  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Deraniyagala's beaked whale...  IND.............       16,867  Wade and            0.00513    0.00516    0.00541    0.00538  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Dwarf sperm whale.............  IND.............       10,541  Wade and            0.00005    0.00005    0.00005    0.00005  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
False killer whale............  IND.............      144,188  Wade and            0.00024    0.00024    0.00024    0.00024  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Fraser's dolphin..............  IND.............      151,554  Wade and            0.00207    0.00207    0.00207    0.00207  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Indo-Pacific bottlenose         IND.............        7,850  Wade and            0.00048    0.00048    0.00047    0.00047  SMRU Ltd., 2012;        NL
 dolphin.                                                       Gerrodette,                                                   DoN, 2018.
                                                                1993.
Killer whale..................  IND.............       12,593  Wade and            0.00697    0.00155    0.00693    0.00694  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Longman's beaked whale........  IND.............       16,867  Wade and            0.00513    0.00516    0.00541    0.00538  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Melon-headed whale............  IND.............       64,600  Wade and            0.00921    0.00920    0.00937    0.00936  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Pantropical spotted dolphin...  IND.............      736,575  Wade and            0.00904    0.00904    0.00904    0.00904  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Pygmy killer whale............  IND.............       22,029  Wade and            0.00138    0.00137    0.00152    0.00153  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Pygmy sperm whale.............  IND.............       10,541  Wade and            0.00001    0.00001    0.00001    0.00001  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Risso's dolphin...............  IND.............      452,125  Wade and            0.08641    0.08651    0.08435    0.08466  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Rough-toothed dolphin.........  IND.............      156,690  Wade and            0.00071    0.00071    0.00071    0.00071  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Short-finned pilot whale......  IND.............      268,751  Wade and            0.03219    0.03228    0.03273    0.03279  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Sperm whale...................  NIND............       24,446  Wade and            0.00129    0.00118    0.00126    0.00121  SMRU Ltd., 2012;        EN
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Spinner dolphin...............  IND.............      634,108  Wade and            0.00678    0.00678    0.00678    0.00678  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Striped dolphin...............  IND.............      674,578  Wade and            0.14601    0.14629    0.14780    0.14788  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ IND = Indian Ocean; NIND = northern Indian Ocean.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.


     Table 14--Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated With Model Area 13, Andaman Sea
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                           Density (animals/km\2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale....................  NIND............        3,691  IWC, 2016.......    0.00003    0.00003    0.00003    0.00003  Kaschner et al.,        EN
                                                                                                                              2006; DoN, 2018.
Bryde's whale.................  NIND............        9,176  Wade and            0.00038   0.000036    0.00037    0.00037  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Common minke whale............  IND.............      257,000  IWC, 2016.......  .........    0.00001    0.00968    0.00001  SMRU Ltd., 2012;        NL
                                                                                                                              DoN, 2018.
Fin whale.....................  IND.............        1,846  IWC, 2016.......    0.00001    0.00001  .........    0.00001  SMRU Ltd., 2012;        EN
                                                                                                                              DoN, 2018.
Omura's whale.................  NIND............        9,176  IWC, 2016.......    0.00038    0.00036    0.00037    0.00037  Kaschner et al.,        NL
                                                                                                                              2006; DoN, 2018.
Blainville's beaked whale.....  IND.............       16,867  Wade and            0.00094    0.00089    0.00094    0.00099  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Common bottlenose dolphin.....  NIND............      785,585  Wade and            0.07578    0.07781    0.07261    0.07212  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Cuvier's beaked whale.........  NIND............       27,272  Wade and            0.00466    0.00482    0.00480    0.00473  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Deraniyagala's beaked whale...  IND.............       16,867  Wade and            0.00094    0.00092    0.00097    0.00099  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Dwarf sperm whale.............  IND.............       10,541  Wade and            0.00005    0.00006    0.00006    0.00005  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
False killer whale............  IND.............      144,188  Wade and            0.00023    0.00023    0.00024    0.00023  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Fraser's dolphin..............  IND.............      151,554  Wade and            0.00176    0.00179    0.00180    0.00180  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Ginkgo-toothed beaked whale...  IND.............       16,867  Wade and            0.00094    0.00092    0.00097    0.00099  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Indo-Pacific bottlenose         IND.............        7,850  Wade and            0.00076    0.00078    0.00073    0.00072  SMRU Ltd., 2012;        NL
 dolphin.                                                       Gerrodette,                                                   DoN, 2018.
                                                                1993.
Killer whale..................  IND.............       12,593  Wade and            0.00744    0.00178    0.00730    0.00734  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Longman's beaked whale........  IND.............       16,867  Wade and            0.00444    0.00429    0.00459    0.00440  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Melon-headed whale............  IND.............       64,600  Wade and            0.00884    0.00884    0.00878    0.00846  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Pantropical spotted dolphin...  IND.............      736,575  Wade and            0.00868    0.00841    0.00829    0.00873  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Pygmy killer whale............  IND.............       22,029  Wade and            0.00121    0.00113    0.00125    0.00131  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Pygmy sperm whale.............  IND.............       10,541  Wade and            0.00001    0.00001    0.00001    0.00001  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Risso's dolphin...............  IND.............      452,125  Wade and            0.09197    0.09215    0.09173    0.09366  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Rough-toothed dolphin.........  IND.............      156,690  Wade and            0.00077    0.00078    0.00077    0.00074  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Short-finned pilot whale......  IND.............      268,751  Wade and            0.03354    0.03364    0.03543    0.03504  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Sperm whale...................  NIND............       24,446  Wade and            0.00109    0.00099    0.00107    0.00105  SMRU Ltd., 2012;        EN
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Spinner dolphin...............  IND.............      634,108  Wade and            0.00736    0.00711    0.00701    0.00726  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Striped dolphin...............  IND.............      674,578  Wade and            0.14413    0.14174    0.14123    0.14402  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ IND = Indian Ocean; NIND = northern Indian Ocean.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.


[[Page 40170]]


     Table 15--Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated With Model Area 14, Northwestern
                                                                        Australia
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                           Density (animals/km\2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Antarctic minke whale.........  ANT.............       90,000  Bannister et      .........    0.00001    0.00001    0.00001  Unavail.........        NL
                                                                al., 1996.
Blue whale/Pygmy blue whale...  SIND............        1,657  Jenner et al.,    .........    0.00003    0.00003    0.00003  Kaschner et al.,        EN
                                                                2008; McCauley                                                2006; DoN, 2018.
                                                                and Jenner,
                                                                2010.
Bryde's whale.................  SIND............       13,854  IWC, 1981.......    0.00032    0.00032    0.00032    0.00032  Kaschner et al.,        NL
                                                                                                                              2006; DoN, 2018.
Common minke whale............  IND.............      257,500  IWC, 2016.......  .........    0.01227    0.01929    0.01947  SMRU Ltd., 2012;        NL
                                                                                                                              DoN, 2018.
Fin whale.....................  SIND............       38,185  Branch and          0.00001    0.00099    0.00128    0.00121  SMRU Ltd., 2012;        EN
                                                                Butterworth,                                                  DoN, 2018.
                                                                2001; Mori and
                                                                Butterworth,
                                                                2006.
Humpback whale................  Western                13,640  Bannister and     .........    0.00007    0.00007    0.00007  Kaschner et al.,        NL
                                 Australia stock                Hedley, 2001.                                                 2006; DoN, 2018.
                                 and DPS.
Omura's whale.................  SIND............       13,854  IWC, 1981.......    0.00032    0.00032    0.00032    0.00032  Kaschner et al.,        NL
                                                                                                                              2006; DoN, 2018.
Sei whale.....................  SIND............       13,854  IWC, 1981.......    0.00001    0.00001    0.00001    0.00001  Unavail.........        EN
Blainville's beaked whale.....  IND.............       16,867  Wade and            0.00083    0.00083    0.00082    0.00083  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Common bottlenose dolphin.....  WAU.............        3,000  Preen et al.,       0.03630    0.03652    0.03459    0.03725  SMRU Ltd., 2012;        NL
                                                                1997.                                                         DoN, 2018.
Cuvier's beaked whale.........  SH..............       76,500  Dalebout et al.,    0.00399    0.00406    0.00402    0.00405  SMRU Ltd., 2012;        NL
                                                                2005.                                                         DoN, 2018.
Dwarf sperm whale.............  IND.............       10,541  Wade and            0.00004    0.00004    0.00004    0.00004  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
False killer whale............  IND.............      144,188  Wade and            0.00020    0.00020    0.00019    0.00020  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Fraser's dolphin..............  IND.............      151,554  Wade and            0.00145    0.00148    0.00149    0.00147  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Killer whale..................  IND.............       12,593  Wade and            0.00585    0.00435    0.00588    0.00580  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Longman's beaked whale........  IND.............       16,867  Wade and            0.00393    0.00393    0.00403    0.00412  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Melon-headed whale............  IND.............       64,600  Wade and            0.00717    0.00717    0.00635    0.00637  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Pantropical spotted dolphin...  IND.............      736,575  Wade and            0.00727    0.00727    0.00715    0.00746  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Pygmy killer whale............  IND.............       22,029  Wade and            0.00100    0.00104    0.00101    0.00097  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Risso's dolphin...............  IND.............      452,125  Wade and            0.07152    0.07214    0.06944    0.07173  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Rough-toothed dolphin.........  IND.............      156,690  Wade and            0.00059    0.00060    0.00059    0.00059  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Short-finned pilot whale......  IND.............      268,751  Wade and            0.02698    0.02759    0.02689    0.02716  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Southern bottlenose whale.....  IND.............      599,300  Wade and            0.00083    0.00083    0.00082    0.00083  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Spade-toothed beaked whale....  IND.............       16,867  Wade and            0.00083    0.00083    0.00082    0.00083  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Sperm whale...................  SIND............       24,446  Wade and            0.00096    0.00087    0.00097    0.00092  SMRU Ltd., 2012;        EN
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
Spinner dolphin...............  IND.............      634,108  Wade and            0.00561    0.00549    0.00568    0.00563  Kaschner et al.,        NL
                                                                Gerrodette,                                                   2006; DoN, 2018.
                                                                1993.
Striped dolphin...............  IND.............      674,578  Wade and            0.12018    0.12041    0.11680    0.11727  SMRU Ltd., 2012;        NL
                                                                Gerrodette,                                                   DoN, 2018.
                                                                1993.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ANT = Antarctic; SIND = southern Indian Ocean; IND = Indian Ocean; SH = Southern Hemisphere; WAU = Western Australia.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.


  Table 16--Abundance and Density Estimates for the Marine Mammal Species, Species Groups, and Stocks Associated With Model Area 15, Northeast of Japan
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                           Density (animals/km\2\)                                ESA
            Species              Stock name \1\    Abundance   Abundance source --------------------------------------------  Density source     status
                                                                   reference       Winter     Spring     Summer      Fall      reference \2\      \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale....................  WNP.............        9,250  Tillman, 1977...    0.00001    0.00001  .........    0.00001  Tillman, 1997;          EN
                                                                                                                              Ferguson and
                                                                                                                              Barlow 2001;
                                                                                                                              2003; LGL, 2008.
Common minke whale............  WNP ``OE''......       25,049  Buckland et al.,     0.0022     0.0022     0.0022     0.0022  Buckland et al.,        NL
                                                                1992.                                                         1992.
Fin whale.....................  WNP.............        9,250  Tillman, 1977...  .........     0.0002     0.0002     0.0002  Tillman, 1977...        EN
Humpback whale................  WNP and DPS.....        1,328  Bettridge et      .........   0.000498   0.000498   0.000498  Kaschner et al.,        EN
                                                                al., 2015.                                                    2006 in DoN,
                                                                                                                              2018.
North Pacific right whale.....  WNP.............          922  Best et al.,      .........  .........    0.00001    0.00001  Unavail.........        EN
                                                                2001.
Sei whale.....................  NP..............        7,000  Mizroch et al.,   .........    0.00029    0.00029  .........  Fulling et al.,         EN
                                                                2015.                                                         2011.
Western North Pacific gray      Western and DPS.          290  Caretta et al.,   .........  .........    0.00001    0.00001  Unavail.........        EN
 whale.                                                         2019.
Baird's beaked whale..........  WNP.............        5,688  Miyashita 1986    .........     0.0015     0.0029     0.0029  Kasuya, 1986....        NL
                                                                and 1990,
                                                                Kasuya and
                                                                Perrin, 2017.
Common dolphin................  WNP.............    3,286,163  Ferguson and         0.0863     0.0863     0.0863     0.0863  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Cuvier's beaked whale.........  WNP.............       90,725  Ferguson and         0.0054     0.0054     0.0054     0.0054  Ferguson and            NL
                                                                Barlow, 2001;                                                 Barlow, 2001;
                                                                2003.                                                         2003.
Dall's porpoise...............  WNP dalli.......      162,000  Miyashita, 1991;     0.0390     0.0520     0.0650     0.0520  Ferguson and            NL
                                                                Kasuya and                                                    Barlow, 2001;
                                                                Perrin, 2017.                                                 2003.
Killer whale..................  WNP.............       12,256  Ferguson and         0.0036     0.0036     0.0036     0.0036  Springer et al.,        NL
                                                                Barlow, 2001;                                                 2003.
                                                                2003.
Pacific white-sided dolphin...  NP..............      931,000  Buckland et al.,     0.0048     0.0048     0.0048     0.0048  Ferguson and            NL
                                                                1993.                                                         Barlow, 2001;
                                                                                                                              2003.
Sperm whale...................  NP..............      102,112  Kato and             0.0017     0.0022     0.0022     0.0022  LGL, 2011.......        EN
                                                                Miyashita, 1998.
Stejneger's beaked whale......  WNP.............        8,000  Kasuya, 1986....     0.0005     0.0005     0.0005     0.0005  Ferguson and            NL
                                                                                                                              Barlow, 2001;
                                                                                                                              2003.
Northern fur seal.............  Western Pacific.      503,609  Kuzin 2015;         0.00689    0.01378    0.01378    0.01378  Buckland et al.,        NL
                                                                Gelatt et al.,                                                1993.
                                                                2015.
Ribbon seal...................  NP..............      365,000  Lowry, 2016.....     0.0904     0.0904     0.0452     0.0452  Moreland et al.,        NL
                                                                                                                              2012.
Spotted seal..................  Alaska/Bering         461,625  Conn et al.,      .........     0.2770     0.1385  .........  Moreland et al.,        NL
                                 Sea DPS.                       2014; Muto et                                                 2012.
                                                                al., 2019.
Steller sea lion..............  West-Asian and         77,767  Muto et al.,        0.00001    0.00001    0.00001    0.00001  Unavail.........        EN
                                 Western DPS.                   2019.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ IND = Indian Ocean; NP = northern Pacific; WNP = western north Pacific; OE = Offshore Japan.
\2\ Unavail = No density estimates are available for this rare species/stock, therefore, the minimum density estimate of 0.00001 animals/km\2\ was used
  in the take analysis to reflect the low probability of occurrence.

[[Page 40171]]

 
\3\ ESA Status: EN = Endangered; T = Threatened; NL = Not Listed.

    Stock abundance and density estimates are derived from the best 
available source documentation and species or stock-specific 
information on the marine mammals that could occur in that area. The 
Navy developed the abundance and density estimates by first using 
estimates from line-transect surveys that occurred in or near each of 
the 15 model sites (e.g., Bradford et al., 2017) and NMFS' SARs. When 
density estimates were not available from a survey in the model area, 
the Navy extrapolated density estimates from a region with similar 
oceanographic characteristics to that model area. For example, the 
eastern tropical Pacific has been extensively surveyed and provides a 
comprehensive understanding of marine mammals in temperate oceanic 
waters (Ferguson and Barlow, 2001, 2003). Density estimates for some 
model areas were also derived from the Navy's Marine Species Density 
Database (DoN, 2018). In addition, density estimates are usually not 
available for rare marine mammal species or for those that have been 
newly defined (e.g., the Deraniyagala's beaked whale). For these 
species, the lowest density estimate of 0.0001 animals/square kilometer 
(0.0001 animals/km\2\) was used in the take analysis to reflect the low 
probability of occurrence in a specific SURTASS LFA sonar model area. 
Further, the Navy pooled density estimates for species of the same 
genus if sufficient data were not available to compute a density for 
individual species or the species are difficult to distinguish at sea, 
which is often the case for beaked whales (e.g., Mesoplodon spp.), as 
well as the pygmy and dwarf sperm whales (Kogia spp.). Density 
estimates are available for species groups rather than the individual 
species for Kogia spp. in model areas 1, 2, 3, 5, 6, and 7 and for 
Mesoplodon spp. in model area 8, and the best available data (Ferguson 
and Barlow, 2001 and 2003) are reported as pooled data.
    The Navy provides detailed descriptions of the distribution, 
abundance, diving behavior, life history, and hearing vocalization 
information for each affected marine mammal species with confirmed or 
possible occurrence within SURTASS LFA sonar study areas in section 4 
(pages 4-1 through 4-44) of the application (available online at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities) and 
Chapter 3 of the 2019 SURTASS LFA FSEIS/SOEIS.
    Although not repeated in this document, NMFS has reviewed these 
data, determined them to be the best available scientific information 
for this rulemaking, and considers this information part of the 
administrative record for this action. Additional information is 
available in NMFS' Marine Mammal Stock Assessment Reports, which may be 
viewed at https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments. There are no active Unusual 
Mortality Events in the SURTASS LFA sonar Study Area.

Potential Effects of the Specified Activity on Marine Mammals and Their 
Habitat

    NMFS provided a brief primer on the subjects of underwater sound, 
the metrics used in the analysis of the effects of underwater sound on 
marine mammals, and marine mammal hearing sensitivities and 
vocalizations in the Brief Background on Sound, Marine Mammal Hearing, 
and Vocalization section of the proposed rule (84 FR 7186; March 1, 
2019). Additionally, NMFS provided a summary and discussion of the 
potential effects of the specified activities (e.g., use of acoustic 
sources) on marine mammals and their habitat in the proposed rule (84 
FR 7186; March 1, 2019). In the Potential Effects of Specified 
Activities on Marine Mammals and Their Habitat section of the proposed 
rule, NMFS provided a description of the potential effects of SURTASS 
LFA sonar training and testing activities on marine mammals, including 
a discussion of serious injury or mortality, physical trauma, sensory 
impairment (permanent and temporary threshold shift and acoustic 
masking), physiological responses (particular stress responses), 
behavioral disturbance, or habitat effects, as well as the results from 
previous SURTASS LFA sonar activities monitoring. Therefore, we do not 
reprint this information here but refer the reader to that document, 
however, we provide an overview of relevant new scientific studies 
below. None of the newer information highlighted here affects our 
analysis in a manner that changes our determinations under the MMPA 
from the proposed rule.

New Pertinent Science Since Publication of the Proposed Rule

    Southall et al. (2019a) evaluated Southall et al. (2007) and used 
updated scientific information to propose revised noise exposure 
criteria to predict onset of auditory effects in marine mammals (i.e., 
PTS and TTS onset). Southall et al. (2019a) note that the quantitative 
processes described and the resulting exposure criteria (i.e., 
thresholds and auditory weighting functions) are largely identical to 
those in Finneran (2016) and NMFS (2016 and 2018). However, they differ 
in that the Southall et al. (2019a) exposure criteria are more broadly 
applicable as they include all marine mammal species (rather than those 
only under NMFS jurisdiction) for all noise exposures (both in air and 
underwater for amphibious species), and while the hearing group 
compositions are identical, Southall et al. (2019a) renamed the hearing 
groups.
    Recent studies on the behavioral responses of cetaceans to mid-
frequency sonar examine and continue to demonstrate the importance of 
not only sound source parameters, but exposure context (e.g., 
behavioral state, presence of other animals and social relationships, 
prey abundance, distance to source, presence of vessels, environmental 
parameters, etc.) in determining or predicting a behavioral response. 
Wensveen et al. (2019) examined the role of sound source (simulated 
sonar pulses) distance and received level in northern bottlenose whales 
in an environment without frequent sonar activity using multi-scaled 
controlled exposure experiments. They observed behavioral avoidance of 
the sound source over a wide range of distances (0.8-28 km) and 
estimated avoidance thresholds ranging from received SPLs of 117-126 dB 
re: 1 [micro]Pa. The behavioral response characteristics and avoidance 
thresholds were comparable to those previously observed in beaked whale 
studies; however, Wensveen et al. (2019) did not observe an effect of 
distance on behavioral response and found that onset and intensity of 
behavioral response were better predicted by received SPL. When 
conducting controlled exposure experiments on blue whales, Southall et 
al. (2019b) observed that after exposure to simulated and operational 
mid-frequency active sonar, more than 50 percent of blue whales in 
deep-diving states responded to the sonar, while no behavioral response 
was observed in shallow-feeding blue whales. The behavioral responses 
they observed were generally brief, of low to moderate severity, and 
highly dependent on exposure context (behavioral state, source-to-whale 
horizontal range, and

[[Page 40172]]

prey availability). Blue whale response did not follow a simple 
exposure-response model based on received sound exposure level. In a 
review of the potential impacts of sonar on beaked whales, Bernaldo de 
Quir[oacute]s et al. (2019) suggested that the effect of mid-frequency 
active sonar on beaked whales varies among individuals or populations, 
and that predisposing conditions such as previous exposure to sonar and 
individual health risk factors may contribute to individual outcomes 
(such as decompression sickness).

Estimated Take of Marine Mammals

    This section indicates the numbers of takes that NMFS is 
authorizing in its LOA, which are based on the maximum number of 
instances in which marine mammals could be reasonably expected to be 
taken, as described in detail below. NMFS coordinated closely with the 
Navy in the development of its incidental take application, and agrees 
that the methods the Navy has put forth described herein to estimate 
take (including the model, thresholds, and density estimates), and the 
resulting numbers estimated for authorization, are appropriate and 
based on the best available science.
    Level B harassment is the only means of take expected to result 
from these activities. 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 behavior 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). As described in the 
Potential Effects of the Specified Activity on Marine Mammals and their 
Habitat section of the proposed rule (84 FR 7186, March 1, 2019), based 
on the specified activities operational parameters and mitigation, only 
Level B Harassment is expected to occur and therefore authorized. Based 
on the nature of the activities and the anticipated effectiveness of 
the mitigation measures, take by Level A Harassment, serious injury, or 
mortality is neither anticipated nor authorized.
    Generally speaking, for acoustic impacts we estimate the amount and 
type of harassment by considering: (1) Acoustic thresholds above which 
NMFS believes the best available science indicates marine mammals will 
be taken by behavioral disruption 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) the 
number of days of activities or events. Below, we describe these 
components in more detail, as well as the model the Navy used to 
incorporate these components to predict impacts, and present the take 
estimates.

Density Estimates

    To derive density estimates, direct estimates from line-transect 
surveys that occurred in or near each of the 15 modeled areas 
(described in the Description of Marine Mammals in the Area of the 
Specified Activities section above) were utilized first (e.g., Bradford 
et al., 2017). When density estimates were not available from a survey 
in the Study Area, density estimates from a region with similar 
oceanographic characteristics were extrapolated to the operational 
area. Densities for some model areas were also derived from the Navy's 
Marine Species Density Database (DoN, 2018a). Last, density estimates 
are usually not available for rare marine mammal species or for those 
that have been newly defined (e.g., Deraniyagala's beaked whale). For 
such species, a low density estimate of 0.0001 animals per square 
kilometer (animals/km\2\) was used in the risk analysis to reflect the 
low probability of occurrence in a specific model area. Further, 
density estimates are sometimes pooled for species of the same genus if 
sufficient data are not available to compute a density for individual 
species or the species are difficult to distinguish at sea. This is 
often the case for beaked whales (Mesoplodon spp) as well as the pygmy 
and dwarf sperm whales (Kogia spp), which is why densities were pooled 
for these species in certain model areas. Density estimates are 
available for these species groups rather than the individual species 
in model areas 1, 2, 3, 5, 6, and 7 for Kogia spp, and in model area 8 
for Mesoplodon spp. Density information is provided in Tables 2 through 
16 above, and is also available in the Navy's application (Table 3-2, 
Pages 3-6 through 3-25) and Chapter 3 and Appendix D of the 2019 
SURTASS LFA FSEIS/SOEIS.

SURTASS LFA Sonar Behavioral Response Function

    To model potential behavioral impacts to marine animals from 
exposure to SURTASS LFA sonar sound, the Navy has developed a 
methodology to estimate the total exposure of modeled animals exposed 
to multiple pings over an extended period of time. NMFS concurs that 
this model is appropriate and utilizes the best available science, and 
adopted the model for use in the analysis to support these regulations. 
The Navy's acoustic model analyzes the following components: (1) The 
LFA sonar source modeled as a point source, with an effective source 
level (SL) of approximately 235 dB re: 1 [mu]Pa at 1 m (SPL) (note: 
This was incorrectly stated as 240 dB in the proposed rule); (2) a 60 
second duration signal; and (3) a beam pattern that is correct for the 
number and spacing of the individual projectors (source elements). This 
source model, when combined with the three-dimensional transmission 
loss (TL) field generated by the Parabolic Equation (PE) acoustic 
propagation model, defines the received level (RL) (in SPL) sound field 
surrounding the source for a 60-second LFA sonar signal (i.e., the SPE 
metric accounts for received level and exposure from multiple pings). 
To estimate the total exposure of animals exposed to multiple pings, 
the Navy models the RLs for each modeled location and any computer-
simulated marine mammals (animats) within the location, records the 
exposure history of each animat, and generates a SPE value. Thus, the 
Navy can model the SURTASS LFA sound field, providing a four-
dimensional (position and time) representation of a sound pressure 
field within the marine environment and estimates of an animal's 
exposure to sound over a period of 24 hours (hrs).
    The Navy uses a behavioral response function to estimate the number 
of behavioral responses that would qualify as behavioral Level B 
harassment under the MMPA. NMFS determined that this threshold is 
appropriate for SURTASS LFA sonar and utilizes the best available 
science and adopted this function for use in the analysis for these 
regulations. The behavioral response function is described fully in 
Chapter 4 and Appendix B of the 2019 SURTASS LFA FSEIS/SOEIS.
    A wide range of behavioral reactions may qualify as Level B 
harassment under the MMPA, including but not limited to avoidance of 
the sound source, temporary changes in vocalizations or dive patterns, 
temporary avoidance of an area, or temporary disruption of feeding, 
migrating, or reproductive behaviors. The estimates calculated using 
the behavioral response function do not differentiate between the 
different types of potential behavioral reactions, nor do the estimates 
provide information regarding the potential fitness or other

[[Page 40173]]

biological consequences of the reactions on the affected individuals.
    The definition of Level B harassment for military readiness 
activities contemplates the disruption of behavioral patterns to the 
point where they are abandoned or significantly altered. It is 
difficult to predict with certainty, given existing data, when 
exposures that are generally expected are likely to result in 
significantly altered or abandoned behavioral patterns. Therefore, the 
Navy's take estimates capture a wider range of impacts, including less 
significant responses. Moreover, NMFS does not assume that each 
instance of Level B harassment modeled by the Navy will have, or is 
likely to have, an adverse impact on an individual's fitness. Rather, 
NMFS considers the available scientific evidence to determine the 
likely nature of the modeled behavioral responses and the potential 
fitness consequences for affected individuals in its negligible impact 
evaluation. Accordingly, we consider application of this Level B 
harassment threshold as identifying the maximum number of instances in 
which marine mammals could be reasonably expected to experience a 
disruption in behavior patterns to a point where they are abandoned or 
significantly altered (i.e., Level B harassment). Because this is the 
most appropriate method for estimating Level B harassment given the 
best available science and uncertainty on the topic, it is these 
numbers of Level B harassment by behavioral disturbance that are 
analyzed in the Negligible Impact Analysis and Determination section 
and authorized.

Estimates of Potential Marine Mammal Exposure

    The Navy's acoustic impact analysis for marine mammals, which NMFS 
has adopted for the purposes of these regulations, represents an 
evolution that builds upon the analysis and methodology documented in 
previous SURTASS LFA sonar NEPA efforts (DoN, 2001; 2007; 2012; and 
2017), and includes updates of the most current acoustic thresholds and 
methodology to assess auditory impacts (NMFS, 2018). A detailed 
discussion of the acoustic impact analysis is provided in Appendix B of 
the 2019 SURTASS LFA FSEIS/SOEIS, but is summarized here.
    Using the Acoustic Integration Model (AIM), the Navy modeled 15 
representative model areas in the central and western North Pacific and 
eastern Indian Oceans, representing the acoustic regimes and marine 
mammal species that may be encountered during SURTASS LFA sonar 
training and testing activities. Modeling was conducted for one 24-hour 
period in each of the four seasons in each model area. To predict 
acoustic exposure, the LFA sonar ship was simulated traveling in a 
triangular pattern at a speed of 4 kt (7.4 kilometers per hour (kph), 
for eight hours in each leg of the triangle. The duration of the LFA 
sonar transmission was modeled as 24 hrs, with a signal duration of 60 
seconds and a duty cycle of 10 percent (i.e., the source transmitted 
for 60 seconds every 10 minutes (min) for 24 hrs, which equates to 2.4 
active transmission hours and is representative of average actual 
transmission times based on the past 17 years of SURTASS LFA sonar 
activities).
    The acoustic field around the LFA sonar source was predicted by the 
Navy standard parabolic equation propagation model using the defined 
LFA sonar operating parameters. Each marine mammal species potentially 
occurring in a model area in each season was simulated by creating 
animats (simulated animals) programmed with behavioral values 
describing their dive and movement patterns. AIM then integrates the 
acoustic field created from the underwater transmission of LFA sonar 
with the three-dimensional (3D) movement of marine mammals to estimate 
their potential for sonar exposure at each 30-second timestep within 
the 24-hr modeling period. Thus, the output of AIM is the time history 
of exposure for each animat.
    The Navy assesses the potential impacts on marine mammals by 
predicting the sound field that a given marine mammal species/stock 
could be exposed to over time in a potential model area. This is a 
multi-part process involving: (1) The ability to measure or estimate an 
animal's location in space and time; (2) the ability to measure or 
estimate the three-dimensional sound field at these times and 
locations; (3) the integration of these two data sets into the acoustic 
impact model to estimate the total acoustic exposure for each animal in 
the modeled population; and (4) the conversion of the resultant 
cumulative exposures for a modeled population into an estimate of the 
risk of a potential injury (i.e., Level A harassment (permanent 
threshold shift (PTS)), temporary threshold shift (TTS), or disruption 
of natural behavioral patterns (i.e., a take estimate for Level B 
harassment).
    To estimate the potential impacts for each marine mammal stock on 
an annual basis, several calculation steps are required. First, the 
potential impact for one LFA sonar transmission hour is calculated. 
Second, the number of LFA sonar transmission hours that may occur in 
each model area for each activity is determined. The third step is to 
determine the number of model areas in which each stock may occur for 
each activity, and the fourth step is to select the maximum per-hour 
impact for each stock that may occur in the model areas for that 
activity. The final step is to multiply the results of steps two, 
three, and four to calculate the potential annual impacts per activity, 
which are then summed across the stocks for a total potential impact 
for all individual activities. The number of individual marine mammals 
that may be taken over the seven-year period of the proposed SURTASS 
LFA sonar training and testing activities was estimated by multiplying 
the maximum number of instances of exposure for each species/stock 
calculated annually for each of the two transmission scenarios (496 
transmission hours in years 1-4 and 592 transmission hours in years 5-
7), and then adding these to calculate a total estimate. For example, 
for the WNP blue whale, four years of 496 transmission hours (for years 
1-4) resulted in 90 Level B harassment takes/year and three years of 
592 transmission hours (for years 5-7) resulted in 123 Level B 
harassment takes/year. Multiplying 90 takes/year by 4 years equals 360 
Level B harassment takes for the 496 transmission hour scenario, and 
multiplying 123 takes/year by 3 years equals 369 Level B harassment 
takes for the 592 transmission hour scenario. The final step is adding 
the totals for the two transmission scenarios to arrive at a total (360 
+ 369 = 729 Level B harassment takes over the 7-year period for WNP 
blue whales). For additional detail on modeling and take estimation, 
please refer to Chapter 6.6 (Quantitative Impact Analysis for Marine 
Mammals) of the Navy's application and Appendix B of the 2019 SURTASS 
LFA FSEIS/SOEIS.
    With the implementation of the three-part monitoring programs 
(visual, passive acoustic, and HF/M3 monitoring, as discussed below), 
NMFS and the Navy do not expect that marine mammals would be injured by 
SURTASS LFA sonar because a marine mammal is likely to be detected and 
active transmissions suspended or delayed to avoid injurious exposure. 
The probability of detection of a marine mammal of any size by the HF/
M3 system within the LFA sonar mitigation zone approaches 100 percent 
over the course of multiple pings (see the 2001 SURTASS LFA FOEIS/EIS, 
Subchapters 2.3.2.2 and 4.2.7.1 for the HF/M3 sonar testing results as 
well as section 5.4.3 of the 2019 SURTASS LFA FSEIS/SOEIS

[[Page 40174]]

for a summary of the effectiveness of the HF/M3 system). 
Quantitatively, modeling output shows zero takes by Level A harassment 
for all marine mammal stocks in all representative mission areas with 
mitigation applied. All hearing groups of marine mammals except LF 
cetaceans would need to be within 22 ft (7 m) of the LFA sonar source 
for an entire LFA transmission (60 seconds), and a LF cetacean would 
need to be within 135 ft (41 m) for an entire LFA transmission to 
potentially experience PTS. This is unlikely to occur, especially given 
the mitigation measures in place and the Navy's proven effectiveness at 
detecting marine mammals well outside of this range so that shut down 
measures would be implemented well before marine mammals would be 
within these ranges. Again, NMFS notes that over the course of the 
previous three rulemakings from 2002 to 2017, and during the Navy's 
training and testing activities during the NDE from 2017 to the 
present, there have been no reported or known incidents of Level A 
harassment of any marine mammal. This is because it would be highly 
unlikely that a marine mammal would remain close enough to the vessel 
to experience Level A harassment (see discussion in Threshold Shift 
subsection of the Potential Effects of the Specified Activity on Marine 
Mammals and their Habitat section of the proposed rulemaking 84 FR 
7186, 7205-7206; March 1, 2019), in combination with the Navy's highly 
effective detection of marine mammals and shutting down SURTASS LFA 
sonar prior to the animals entering the Level A harassment zone. 
Therefore, NMFS does not anticipate and does not authorize any Level A 
harassment takes for any marine mammal species or stocks over the 
course of the seven-year regulations.
    The distances to the TTS thresholds are less than 50 ft (15 m) for 
mid-frequency (MF) and high-frequency (HF) cetaceans and otariids; 216 
ft (66 m) for phocids; and 1,354 ft (413 m) for low-frequency (LF) 
cetaceans if an animal were to remain at those distances for an entire 
LFA sonar signal (60 sec). While it is likely that mitigation measures 
would also avoid TTS, some small subset of the animals may also 
experience TTS if exposed for longer periods of time at greater 
distances; however, any of the TTS impacts would be expected to be 
captured within the estimate of Level B harassment takes by behavioral 
disruption and separate enumeration is not necessary or appropriate. 
Any TTS incurred would likely be of a low level and of short duration 
because we do not expect animals to be exposed for long durations close 
to the source.
    Of note, the estimated number of Level B harassment takes does not 
necessarily equate to the number of individual animals the Navy expects 
to harass (which is lower), but rather to the instances of take (i.e., 
exposures above the Level B harassment threshold) that are anticipated 
to occur over the seven-year period. Some individuals may experience 
multiple instances of take (meaning over multiple days) over the course 
of the year, while some members of a species or stock may not 
experience take at all, which means that the number of individuals 
taken is likely somewhat smaller than the total estimated takes. 
Generally speaking, the higher the number of takes as compared to the 
population abundance, the more repeated takes of individuals are 
likely, and the higher the actual percentage of individuals in the 
population that are likely taken at least once in a year. However, 
because of the nature of the SURTASS LFA activities (small number of 
continuously moving vessels spread over a very large area), there are 
likely fewer repeated takes of the same individuals than would be 
expected from other more localized or stationary activities.
    More detailed information for each of the steps to quantify take 
estimates, as well as an illustrative example, are provided in section 
6.6 of the Navy's application (Quantitative Impact Analysis for Marine 
Mammals). A more thorough description of the impact analysis is also 
provided in the 2019 SURTASS LFA FEIS/SOEIS, specifically section 
4.5.2.1.3, Marine Mammals (Quantitative Impact Analysis for Marine 
Mammals subsection) and Appendix B (Marine Mammal Impact Analysis). 
NMFS has reviewed this information and has accepted the Navy modeling 
procedure and results. The total maximum potential impact on an annual 
basis for years 1-4 and years 5-7 as well as the total overall takes 
for the seven-year period covered by this rulemaking are presented in 
Table 17 below. These are considered conservative estimates because 
they are based on the maximum potential impact to a species or stock 
across all model areas in which an activity may occur. Therefore, if an 
activity occurs in a different model area than the area where the 
maximum potential impact was predicted, the actual potential impact may 
be less than estimated. However, since the Navy cannot forecast where a 
specific activity may be conducted this far in advance, this maximum 
estimate provides the Navy with the flexibility to conduct its training 
and testing activities across all modeled areas identified for each 
activity.

   Table 17--Maximum Total Annual MMPA Level B Harassment Proposed for Authorization for Years 1-4 and 5-7, and Total for the Seven-Year Period of the
                                                             Final Rule by SURTASS LFA Sonar
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                              Maximum annual Level B          Maximum annual Level B
                                                                               harassment, years 1-4           harassment, years 5-7       Total overall
                                                                         ----------------------------------------------------------------     Level B
                  Species                             Stock \1\                                                               Percent     harassment for
                                                                             Instances    Percen species     Instances      species or     7-year period
                                                                                             or stock                          stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Antarctic minke whale.....................  ANT.........................               0            0.00               0            0.00               0
Blue whale................................  CNP.........................               3            2.39               4            2.85              24
                                            NIND........................               0            0.00               1            0.00               3
                                            WNP.........................              90            0.90             123            1.14             729
                                            SIND........................               1           0 .07               1            0.07               7
Bryde's whale.............................  ECS.........................              14           10.28              19           14.13             113
                                            Hawaii......................               5            0.62               6            0.74              38
                                            WNP.........................             378            1.94             437            2.26           2,823
                                            NIND........................               8            0.07              10            0.10              62
                                            SIND........................               7            0.05               9            0.07              55
Common minke whale........................  Hawaii......................             572            2.30             682            2.74           4,334
                                            IND.........................           1,271            0.43           1,748            0.59          10,328
                                            WNP JW......................               3            0.12               5            0.17              27

[[Page 40175]]

 
                                            WNP OE......................           2,127            8.59           2,404            9.71          15,720
                                            YS..........................             189            4.20             250            5.57           1,506
Fin whale.................................  ECS.........................               9            1.80              12            2.47              72
                                            Hawaii......................               3            2.30               4            2.74              24
                                            IND.........................               0            0.00               0            0.00               0
                                            SIND........................              22            0.05              30            0.07             178
                                            WNP.........................           2,558           27.55           3,455           37.23          20,597
Humpback whale............................  CNP stock and Hawaii DPS....             487            4.85             611            6.10           3,781
                                            WAU stock and DPS...........               1            0.00               1            0.00               7
                                            WNP stock and DPS...........           3,103          233.84           4,266          321.49          25,210
North Pacific right whale.................  WNP.........................              89            9.57             122           13.15             722
Omura's whale.............................  NIND........................               8            0.07              10            0.10              62
                                            SIND........................               5            0.04               7            0.05              41
                                            WNP.........................              14            0.81              16            0.95             104
Sei whale.................................  Hawaii......................              19            4.78              22            5.70             142
                                            SIND........................               0            0.00               0            0.00               0
                                            NP..........................           3,172           45.37           4,361           62.37          25,771
                                            NIND........................               4            0.04               5            0.05              31
Western North Pacific gray whale..........  WNP stock and Western DPS...               0            0.00               1            0.20               3
Baird's beaked whale......................  WNP.........................           2,747           48.26           3,777           66.36          22,319
Blainville's beaked whale.................  Hawaii......................              35            1.83              47            2.40             281
                                            WNP.........................             269            3.30             311            3.82           2,009
                                            IND.........................              47            0.27              65            0.37             383
Common bottlenose dolphin.................  4-Islands...................               5            2.48               6            2.96              38
                                            Hawaii Island...............               0            0.00               0            0.00               0
                                            Hawaii Pelagic..............              95            0.41             114            0.49             722
                                            IA..........................             104            0.11             140            0.15             836
                                            IND.........................           1,128            0.14           1,551            0.20           9,165
                                            Japanese Coastal............           1,686           47.94           1,789           50.86          12,111
                                            Kauai/Niihau................              13            7.16              16            8.55             100
                                            Oahu........................              38            5.17              46            6.17             290
                                            WNP Northern Offshore.......             581            0.57             799            0.78           4,721
                                            WNP Southern Offshore.......           2,726            6.63           3,063            7.45          20,093
                                            WAU.........................             635           21.16             873           29.09           5,159
Common dolphin............................  IND.........................              52            0.00              72            0.00             424
                                            WNP.........................         203,871           12.24         275,079           16.08       1,640,721
Cuvier's beaked whale.....................  Hawaii......................              22            3.03              26            3.62             166
                                            IND.........................             231            0.85             317            1.17           1,875
                                            SH..........................              77            0.11             106            0.15             626
                                            WNP.........................           6,946            7.78           8,980           10.04          54,724
Dall's porpoise...........................  SOJ dalli type..............             614            0.36             845            0.49           4,991
                                            WNP dalli ecotype...........          22,056           13.62          30,327           18.72         179,205
                                            WNP truei ecotype...........             487            0.28             670            0.39           3,958
Deraniyagala's beaked whale...............  IND.........................             158            0.92             217            1.27           1,283
                                            NP..........................             342            1.41             412            1.69           2,620
Dwarf sperm whale.........................  Hawaii......................             655            3.72             782            4.44           4,966
                                            IND.........................               3            0.05               4            0.07              24
                                            WNP.........................             486            0.14             635            0.18           3,849
False killer whale........................  Hawaii Pelagic..............              58            3.72              69            4.44             439
                                            IA..........................             252            2.59             341            3.51           2,031
                                            IND.........................              12            0.01              16            0.00              96
                                            Main Hawaiian Islands                      1            0.41               1            0.49               7
                                             Insular stock and DPS.
                                            Northwestern Hawaiian                      0            0.00               0            0.00               0
                                             Islands.
                                            WNP.........................           1,350            8.15           1,596            9.63          10,188
Fraser's dolphin..........................  CNP.........................             546            3.24             686            4.06           4,242
                                            Hawaii......................           1,944            3.79           2,320            4.52          14,736
                                            IND.........................              93            0.05             128            0.07             756
                                            WNP.........................           2,287            1.16           2,559            1.29          16,825
Ginkgo-toothed beaked whale...............  IND.........................              12            0.07              16            0.10              96
                                            NP..........................             476            2.00             568            2.38           3,608
Harbor porpoise...........................  WNP.........................             366            1.17             503            1.61           2,973

[[Page 40176]]

 
Hubbs' beaked whale.......................  NP..........................              26            0.11              36            0.15             212
Indo-Pacific bottlenose dolphin...........  IND.........................              11            0.14              16            0.20              92
Killer whale..............................  Hawaii......................               6            4.41               8            5.26              48
                                            IND.........................             397            3.15             546            4.33           3,226
                                            WNP.........................          10,470           85.37          14,387          117.31          85,041
Kogia spp.\2\.............................  WNP.........................           1,317            0.31           1,494            0.35           9,750
Longman's beaked whale....................  Hawaii......................             739            5.01             882           11.59           5,602
                                            IND.........................             325            1.92             447            2.64           2,641
                                            WNP.........................             471            6.14             574            7.50           3,606
Melon-headed whale........................  Hawaiian Islands............             181            2.07             216            2.47           1,372
                                            IND.........................             402            0.64             552            0.88           3,264
                                            Kohala Resident.............               9            0.41              11            0.49              69
                                            WNP.........................           1,605            2.87           1,823            3.27          11,889
Mesoplodon spp.\2\........................  WNP.........................              10            0.05              14            0.07              82
Northern right whale dolphin..............  NP..........................               0            0.00               0            0.00               0
Pacific white-sided dolphin...............  NP..........................           9,530            1.05          12,890            1.41          76,790
Pantropical spotted dolphin...............  4-Islands...................              32           14.40              38           17.18             242
                                            Hawaii Island...............              23           10.26              27           12.25             173
                                            Hawaiian Pelagic............             297            0.55             355            0.66           2,253
                                            IND.........................             311            0.05             428            0.07           2,528
                                            Oahu........................              23           10.54              28           12.58             176
                                            WNP.........................           5,105            3.95           5,883            4.53          38,069
Pygmy killer whale........................  Hawaii......................             393            3.72             469            4.44           2,979
                                            IND.........................              60            0.27              82            0.37             486
                                            WNP.........................             901            2.87           1,035            3.30           6,709
Pygmy sperm whale.........................  Hawaii......................             266            3.72             318            4.44           2,018
                                            IND.........................               0            0.00               0            0.00               0
                                            WNP.........................             203            0.07             265            0.09           1,607
Risso's dolphin...........................  Hawaii......................             414            3.58             494            4.28           3,138
                                            IA..........................           1,045            0.70           1,374            0.92           8,302
                                            WNP.........................           4,347            3.07           4,914            3.47          32,130
                                            IND.........................           4,621            1.01           6,354            1.39          37,546
Rough-toothed dolphin.....................  Hawaii......................             213            0.28             254            0.33           1,614
                                            IND.........................              41            0.00              57            0.00             335
                                            WNP.........................           1,439           28.74           1,732           34.56          10,952
Short-finned pilot whale..................  Hawaii......................             396            2.00             473            2.38           3,003
                                            IND.........................           1,526            0.59           2,098            0.81          12,398
                                            WNP Northern Ecotype........             525            2.52             721            3.47           4,263
                                            WNP Southern Ecotype........           5,683           18.03           6,303           19.99          41,641
Southern bottlenose whale.................  IND.........................              22            0.00              31            0.00             181
Spade-toothed beaked whale................  IND.........................              16            0.09              22            0.12             130
Sperm whale...............................  Hawaii......................             106            2.34             126            2.80             802
                                            NIND........................              33            0.14              46            0.20             270
                                            NP..........................           1,429            1.28           1,855            1.68          11,281
                                            SIND........................              16            0.07              22            0.10             130
Spinner dolphin...........................  Hawaii Island...............               1            0.19               1            0.22               7
                                            Hawaii Pelagic..............             192            5.72             229            6.82           1,455
                                            IND.........................             240            0.05             330            0.07           1,950
                                            Kauai/Niihau................              83           13.85              99           16.53             629
                                            Kure/Midway Atoll...........               0            0.00               0            0.00               0
                                            Oahu/4-Islands..............              20            2.88              24            6.66             152
                                            Pearl and Hermes Reef.......               0            0.00               0            0.00               0
                                            WNP.........................             574            0.00             721            0.00           4,459
Stejneger's beaked whale..................  WNP.........................             201            2.49             276            3.42           1,632
Striped dolphin...........................  Hawaii......................             269            0.41             321            0.49           2,039
                                            IND.........................           5,059            0.75           6,957            1.03          41,107
                                            Japanese Coastal............           3,366           17.18           3,571           18.23          24,177
                                            WNP Northern Offshore.......             267            0.07             367            0.10           2,169
                                            WNP Southern Offshore.......           3,282            6.28           3,729            7.13          24,315
Hawaiian monk seal........................  Hawaii......................              10            0.69              13            0.91              79
Northern fur seal.........................  Western Pacific.............           8,475            1.71          11,653            2.35          68,859
Ribbon seal...............................  NP..........................          15,705            4.30          21,595            5.92         127,605
Spotted seal..............................  Alaska stock/Bering Sea DPS.          80,722           17.53         110,993           24.10         655,867

[[Page 40177]]

 
                                            Southern stock and DPS......               0            0.00               1            0.04               3
Steller sea lion..........................  Western/Asian stock, Western               2            0.00               3            0.00              17
                                             DPS.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ANT = Antarctic; CNP = Central North Pacific; NP = North Pacific; NIND = Northern Indian; SIND = Southern Indian; IND = Indian; WNP = Western North
  Pacific; ECS = East China Sea; WP = Western Pacific; SOJ = Sea of Japan; IA = Inshore Archipelago; WAU = Western Australia; YS = Yellow Sea; OE =
  Offshore Japan; OW = Nearshore Japan; JW = Sea of Japan/Minke; JE = Pacific coast of Japan; SH = Southern Hemisphere; DPS = distinct population
  segment.
\2\ Kogia spp: Pygmy and dwarf sperm whales are difficult to distinguish at sea, and abundance estimates are pooled for Kogia spp in Modeled Areas 1, 2,
  3, 5, 6, and 7 (reported as pooled in Ferguson and Barlow, 2001 and 2003, and pooled). Mesoplodon spp: No methods are available to distinguish between
  the species of Mesoplodon beaked whales in the WNP 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., 2018). As reported in Ferguson and Barlow, 2001 and 2003, data on these species
  were pooled. These six species are managed as one unit.

Mitigation

    Under section 101(a)(5)(A) of the MMPA, NMFS must set forth the 
``permissible methods of taking pursuant to such activity, and other 
means of effecting the least practicable adverse impact on such species 
or stock and its habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance, and on the 
availability of such species or stock for subsistence uses'' 
(hereinafter referred to as ``LPAI'' or ``least practicable adverse 
impact''). NMFS does not have a regulatory definition for least 
practicable adverse impact. The NDAA for FY 2004 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.

Least Practicable Adverse Impact Standard

    In Conservation Council for Hawaii v. National Marine Fisheries 
Service, 97 F. Supp.3d 1210, 1229 (D. Haw. 2015), the Court stated that 
NMFS ``[appear[s] to think [it] satisfies] the statutory `least 
practicable adverse impact' requirement with a `negligible impact' 
finding.'' More recently, expressing similar concerns in a challenge to 
the 2012 SURTASS LFA sonar incidental take rule (77 FR 50290; August 
12, 2012), the Ninth Circuit Court of Appeals in Natural Resources 
Defense Council (NRDC) v. Pritzker, 828 F.3d 1125, 1134 (9th Cir. 
2016), stated, ``[c]ompliance with the `negligible impact' requirement 
does not mean there [is] compliance with the `least practicable adverse 
impact' standard.'' As the Ninth Circuit noted in its opinion, however, 
the Court was interpreting the statute without the benefit of NMFS' 
formal interpretation. We state here explicitly that NMFS is in full 
agreement that the ``negligible impact'' and ``least practicable 
adverse impact'' requirements are distinct, even though both statutory 
standards refer to species and stocks. With that in mind, we provide 
further explanation of our interpretation of least practicable adverse 
impact, and explain what distinguishes it from the negligible impact 
standard. This discussion is consistent with, and expands upon, 
previous rules we have issued, such as the Navy Gulf of Alaska rule (82 
FR 19530; April 27, 2017); the Navy Atlantic Fleet Testing and Training 
rule (83 FR 57076; November 14, 2018); and the Navy Hawaii-Southern 
California Training and Testing rule (83 FR 66846; December 27, 2018).
    Before NMFS can issue incidental take regulations under section 
101(a)(5)(A) of the MMPA, it must make a finding that the total taking 
will have a ``negligible impact'' on the affected ``species or stocks'' 
of marine mammals. NMFS' and USFWS' implementing regulations for 
section 101(a)(5) both define ``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 and 50 CFR 18.27(c)). Recruitment (i.e., 
reproduction) and survival rates are used to determine population 
growth rates \3\ and, therefore are considered in evaluating population 
level impacts.
---------------------------------------------------------------------------

    \3\ A growth rate can be positive, negative, or flat.
---------------------------------------------------------------------------

    As we stated in the preamble to the final rule for the incidental 
take implementing regulations, not every population-level impact 
violates the negligible impact requirement. The negligible impact 
standard does not require a finding that the anticipated take will have 
``no effect'' on population numbers or growth rates: ``The statutory 
standard does not require that the same recovery rate be maintained, 
rather that no significant effect on annual rates of recruitment or 
survival occurs. [T]he key factor is the significance of the level of 
impact on rates of recruitment or survival.'' (54 FR 40338, 40341-42; 
September 29, 1989).
    While some level of impact on population numbers or growth rates of 
a species or stock may occur and still satisfy the negligible impact 
requirement--even without consideration of mitigation--the least 
practicable adverse impact provision separately requires NMFS to 
prescribe means of ``effecting the least practicable adverse impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance,'' 50 CFR 
216.102(b), which are typically identified as mitigation measures.\4\
---------------------------------------------------------------------------

    \4\ For purposes of this discussion, we omit reference to the 
language in the standard for least practicable adverse impact that 
says we also must mitigate for subsistence impacts because they are 
not at issue in this regulation.
---------------------------------------------------------------------------

    The negligible impact and LPAI standards in the MMPA both call for 
evaluation at the level of the ``species or stock.'' The MMPA does not 
define the term ``species.'' However, Merriam-Webster Dictionary 
defines ``species'' to include ``related organisms or

[[Page 40178]]

populations potentially capable of interbreeding.'' See www.merriam-webster.com/dictionary/species (emphasis added). The MMPA defines 
``stock'' as a group of marine mammals of the same species or smaller 
taxa in a common spatial arrangement that interbreed when mature (16 
U.S.C. 1362(11)). The definition of ``population'' is a group of 
interbreeding organisms that represents the level of organization at 
which speciation begins. www.merriam-webster.com/dictionary/population. 
The definition of ``population'' is strikingly similar to the MMPA's 
definition of ``stock,'' with both involving groups of individuals that 
belong to the same species and located in a manner that allows for 
interbreeding. In fact, the term ``stock'' in the MMPA is 
interchangeable with the statutory term ``population stock'' (16 U.S.C. 
1362(11)). Both the negligible impact standard and the least 
practicable adverse impact standard call for evaluation at the level of 
the species or stock, and the terms ``species'' and ``stock'' both 
relate to populations; therefore, it is appropriate to view both the 
negligible impact standard and the least practicable adverse impact 
standard as having a population-level focus.
    This interpretation is consistent with Congress's statutory 
findings for enacting the MMPA, nearly all of which are most applicable 
at the species or stock (i.e., population) level. See 16 U.S.C. 1361 
(finding that it is species and population stocks that are or may be in 
danger of extinction or depletion; that it is species and population 
stocks that should not diminish beyond being significant functioning 
elements of their ecosystems; and that it is species and population 
stocks that should not be permitted to diminish below their optimum 
sustainable population level). Annual rates of recruitment (i.e., 
reproduction) and survival are the key biological metrics used in the 
evaluation of population-level impacts, and accordingly these same 
metrics are also used in the evaluation of population level impacts for 
the least practicable adverse impact standard.
    Recognizing this common focus of the least practicable adverse 
impact and negligible impact provisions on the ``species or stock'' 
does not mean we conflate the two standards. Despite some common 
statutory language, we recognize the two provisions are different and 
have different functions. First, a negligible impact finding is 
required before NMFS can issue an incidental take authorization. 
Although it is acceptable to use the mitigation measures to reach a 
negligible impact finding (see 50 CFR 216.104(c)), no amount of 
mitigation can enable NMFS to issue an incidental take authorization 
for an activity that still would not meet the negligible impact 
standard. Moreover, even where NMFS can reach a negligible impact 
finding--which we emphasize does allow for the possibility of some 
``negligible'' population-level impact--the agency must still prescribe 
measures that will affect the least practicable amount of adverse 
impact upon the affected species or stock.
    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 and their habitat. 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, we reiterate that the LPAI 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.\5\
---------------------------------------------------------------------------

    \5\ 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).\\
---------------------------------------------------------------------------

    In NRDC v. Pritzker, the Court stated, ``[t]he statute is properly 
read to mean that even if population levels are not threatened 
significantly, still the agency must adopt mitigation measures aimed at 
protecting marine mammals to the greatest extent practicable in light 
of military readiness needs.'' Id. at 1134 (emphases added). This 
statement is consistent with our understanding stated above that even 
when the effects of an action satisfy the negligible impact standard 
(i.e., in the Court's words, ``population levels are not threatened 
significantly''), still the agency must prescribe mitigation under the 
least practicable adverse impact standard. However, as the statute 
indicates, the focus of both standards is ultimately the impact on the 
affected ``species or stock,'' and not solely focused on or directed at 
the impact on individual marine mammals.
    We have carefully reviewed and considered the Ninth Circuit's 
opinion in NRDC v. Pritzker in its entirety. While the Court's 
reference to ``marine mammals'' rather than ``marine mammal species or 
stocks'' in the italicized language above might be construed as a 
holding that the least practicable adverse impact standard applies at 
the individual ``marine mammal'' level, i.e., that NMFS must require 
mitigation to minimize impacts to each individual marine mammal unless 
impracticable, we believe such an interpretation reflects an incomplete 
appreciation of the Court's holding. In our view, the opinion as a 
whole turned on the Court's determination that NMFS had not given 
separate and independent meaning to the least practicable adverse 
impact standard apart from the negligible impact standard, and further, 
that the Court's use of the term ``marine mammals'' was not addressing 
the question of whether the standard applies to individual animals as 
opposed to the species or stock as a whole. We recognize that while 
consideration of mitigation can play a role in a negligible impact 
determination, consideration of mitigation measures extends beyond that 
analysis. 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 describe below.
Implementation of Least Practicable Adverse Impact Standard
    Given the NRDC v. Pritzker decision, we discuss here how we 
determine whether a measure or set of measures meets the ``least 
practicable adverse impact'' standard. Our separate analysis of whether 
the take anticipated to result from Navy's activities meets the 
``negligible impact'' standard appears in the Negligible Impact 
Analysis and Determination section below.
    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

[[Page 40179]]

likelihood of successful implementation; and
    (2) The practicability of the measures 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. 16 U.S.C. 1371(a)(5)(A)(iii).
    While the language of the least practicable adverse impact standard 
calls for minimizing impacts to affected species or stocks and their 
habitats, 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 mitigation measures that are designed to avoid or minimize 
impacts on individual marine mammals that have the potential 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. 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 
that we had not previously considered, becomes available and 
necessitates 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 
reducing the potential for, or severity of, 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 their 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. We discuss consideration of these factors in 
greater detail below.
    1. Reduction of adverse impacts to marine mammal species or stocks 
and their habitat.\6\
---------------------------------------------------------------------------

    \6\ We recognize the least practicable adverse impact standard 
requires consideration of measures that will address minimizing 
impacts on the availability of the species or stocks for subsistence 
uses where relevant. Because subsistence uses are not implicated for 
this action, we do not discuss them. However, a similar framework 
would apply for evaluating those measures, taking into account the 
MMPA's directive that we make a finding of no unmitigable adverse 
impact on the availability of the species or stocks for taking for 
subsistence, and the relevant implementing regulations.
---------------------------------------------------------------------------

    The emphasis given to a measure's ability to reduce the impacts on 
a species or stock considers the degree, likelihood, and context of the 
anticipated reduction of impacts to individuals (and how many 
individuals) as well as the status of the species or stock.
    The ultimate impact on any individual from a disturbance event 
(which informs the likelihood of adverse species- or stock-level 
effects) is dependent on the circumstances and associated contextual 
factors, such as duration of exposure to stressors. Though any proposed 
mitigation needs to be evaluated in the context of the specific 
activity and the species or stocks affected, measures with the 
following types of effects have greater value in reducing the 
likelihood or severity of adverse species- or stock-level impacts: 
Avoiding or minimizing injury or mortality; limiting interruption of 
known feeding, breeding, mother/young, or resting behaviors; minimizing 
the abandonment of important habitat (temporally and spatially); 
minimizing the number of individuals subjected to these types of 
disruptions; and limiting degradation of habitat. Mitigating these 
types of effects is intended to reduce the likelihood that the activity 
will result in energetic or other types of impacts that are more likely 
to result in reduced reproductive success or survivorship. It is also 
important to consider the degree of impacts that are expected in the 
absence of mitigation in order to assess the added value of any 
potential measures. Finally, because the least practicable adverse 
impact standard gives NMFS discretion to weigh a variety of factors 
when determining appropriate mitigation measures and because the focus 
of the standard is on reducing impacts at the species or stock level, 
the least practicable adverse impact standard does not compel 
mitigation for every kind of take, or every individual taken, if that 
mitigation is unlikely to contribute meaningfully to the reduction of 
adverse impacts on the species or stock and its habitat, even when 
practicable for implementation by the applicant.
    The status of the species or stock is also relevant in evaluating 
the appropriateness of potential mitigation measures in the context of 
least practicable adverse impact. The following are examples of factors 
that may (either alone, or in combination) result in greater emphasis 
on the importance of a mitigation measure in

[[Page 40180]]

reducing impacts on a species or stock: The stock is known to be 
decreasing or status is unknown, but believed to be declining; the 
known annual mortality (from any source) is approaching or exceeding 
the potential biological removal (PBR) level (as defined in 16 U.S.C. 
1362(20)); the affected species or stock is a small, resident 
population; or the stock is involved in a UME or has other known 
vulnerabilities, such as recovering from an oil spill.
    Habitat mitigation, particularly as it relates to rookeries, mating 
grounds, and areas of similar significance, is also relevant to 
achieving the standard and can include measures such as reducing 
impacts of the activity on known prey utilized in the activity area or 
reducing impacts on physical habitat. As with species- or stock-related 
mitigation, the emphasis given to a measure's ability to reduce impacts 
on a species or stock's habitat considers the degree, likelihood, and 
context of the anticipated reduction of impacts to habitat. Because 
habitat value is informed by marine mammal presence and use, in some 
cases there may be overlap in measures for the species or stock and for 
use of habitat.
    We consider available information indicating the likelihood of any 
measure to accomplish its objective. If evidence shows that a measure 
has not typically been effective nor successful, then either that 
measure should be modified or the potential value of the measure to 
reduce effects should be lowered.
    2. Practicability. Factors considered may include cost, impact on 
activities, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity (16 U.S.C. 
1371(a)(5)(A)(iii)).

Mitigation Measures

    As with other rulemakings for SURTASS LFA sonar, our consideration 
of mitigation under the LPAI standard was conducted at scales that take 
into account the entire rulemaking period and geographic scope of 
potential areas of SURTASS LFA sonar activities and the types of 
impacts that could occur under the rule. NMFS reviewed the proposed 
activities and the proposed mitigation measures as described in the 
Navy's application, and the measures added by NMFS, to determine if 
they would satisfy the standard of LPAI on marine mammal species or 
stock(s) and their habitat. Since the proposed rule 14 OBIAs have been 
designated and additional mitigation has been added that limits the 
number of hours of SURTASS LFA sonar transmission occurring around any 
single OBIA (see below). As described below, and in the 2019 SURTASS 
LFA FSEIS/SOEIS, NMFS has determined that the following mitigation 
measures would satisfy the LPAI standard:
    (1) 2,000-yd LFA sonar mitigation zone--LFA sonar training and 
testing transmissions will be suspended if the Navy detects marine 
mammals within a distance of 2,000 yds (1.8 km; 1.1 mi; 1.0 nmi) of the 
LFA sonar source, which encompasses both the approximately 1-km radial 
distance of the 180 dB re: 1 [mu]Pa rms received level mitigation zone 
and an additional buffer, by any of the following detection methods:
    (a) Visual monitoring;
    (b) Passive acoustic monitoring; and
    (c) Active acoustic monitoring.
    (2) Geographic restrictions--LFA sonar training and testing will be 
conducted such that:
    (a) The received level of SURTASS LFA sonar transmissions during 
training and testing events will not exceed 180 dB re: 1 [mu]Pa rms 
within 1 km seaward of any OBIA boundary, during the indicated periods 
of biological importance;
    (b) no more than 25 percent of the authorized amount (transmission 
hours) of SURTASS LFA sonar for training and testing will be used 
within 10 nmi (18.5 km) of any single OBIA during any year (no more 
than 124 hours in years 1-4 and 148 hours in years 5-7) unless the 
following conditions are met: Should national security present a 
requirement to conduct more than 25 percent of authorized hours of 
SURTASS LFA sonar within 10 nmi (18.5 km) of any single OBIA during any 
year, naval units will obtain permission from the appropriate 
designated Command authority prior to commencement of the activity. The 
Navy will provide NMFS with notification as soon as is practicable and 
include the information (e.g., sonar hours) in its annual activity 
reports submitted to NMFS.
    (c) the received level of SURTASS LFA sonar transmissions will not 
exceed 180 dB re: 1 [mu]Pa rms within the Coastal Standoff Zone (22 km 
(12 nmi) from any land);
    (d) no activities with the SURTASS LFA sonar system will occur 
within territorial seas of foreign nations, which are areas up to 12 
nmi from shore, depending on the distance that individual nations 
claim; and
    (e) no activities with the SURTASS LFA sonar system will occur 
within the waters of Penguin Bank, Hawaii (defined as water depth of 
600 ft (183 m)), and ensonification of Hawaii state waters (out to 3 
nmi) will not exceed 145 dB re: 1 [mu]Pa rms. This measure, which is a 
result of an agreement between the Navy and the State of Hawaii through 
its CZMA Program, was correctly described in the 2018 Draft SURTASS LFA 
SEIS/SOEIS and 2019 SURTASS LFA FSEIS/SOEIS. The proposed rule 
incorrectly suggested that Navy would not operate the SURTASS LFA sonar 
system within Hawaii state waters. The description of this measure is 
corrected in this final rule.
    Below, we discuss the mitigation measures as agreed upon by the 
Navy and NMFS. For additional details regarding the Navy's mitigation 
measures, please also see Chapter 5 in the 2019 SURTASS LFA FSEIS/
SOEIS.
2,000-yard Mitigation Zone (Re-Evaluation of the 180 dB re: 1 [micro]Pa 
rms Zone)
    The Navy requested, and NMFS includes in this rule, a single, fixed 
2,000-yard (yd) (0.99 nmi/1,829 m/1.83 km) mitigation zone rather than 
a combined mitigation and buffer zone (based on real-time propagation 
modeling) of nominally 1.08 nmi (2 km), which has been required in past 
rules. This modification will standardize and simplify Navy mitigation 
and monitoring implementation and includes consideration of updated 
information on marine mammal injury thresholds. The 180 dB re: 1 
[micro]Pa rms threshold for the onset of potential injury has been used 
in the impact assessment for SURTASS LFA sonar since 2001, and the 
isopleth associated with that threshold has also previously informed 
the development of mitigation. However, NMFS' 2018 Revision to: 
Technical Guidance for Assessing the Effect of Anthropogenic Sound on 
Marine Mammal Hearing (NMFS, 2018, hereafter referred to as ``NMFS' 
2018 Acoustic Technical Guidance'') reflects the current state of 
scientific knowledge regarding the potential impacts of sound on marine 
mammal hearing. It specifies auditory weighted (SELcum) 
values for the onset of PTS (onset of injury) based on marine mammal 
hearing groups. The NMFS 2018 Acoustic Technical Guidance categorizes 
marine mammals into five generalized hearing groups with defined 
hearing ranges and presents the auditory weighting functions developed 
for each of these hearing groups, reflecting the best available data on 
hearing, impacts of sound on hearing, and data on equal latency.
    When estimating the onset of injury for non-impulsive sound sources 
(PTS), NMFS' 2018 Acoustic Technical Guidance defines weighted 
thresholds as cumulative sound exposure levels (SELcum). The 
new thresholds and their associated metric incorporate a duration 
component, which means that they are

[[Page 40181]]

not directly comparable to the previous 180 dB re: 1 [micro]Pa rms SPL 
threshold. To determine what the SELcum for each hearing 
group would be when exposed to a 60-second (the nominal time of an LFA 
sonar transmission, or one ping), 300 Hz (the center frequency in the 
possible sonar transmission range of 100-500 Hz, single element source 
level of 215 dB re: 1 [micro]Pa at 1 m) SURTASS LFA sonar transmission, 
the appropriate auditory weighting function must be applied to account 
for each hearing group's sensitivity. Again, although direct 
comparisons are difficult, when a 300 Hz, 60-second exposure is 
considered, applying the auditory weighting functions results in the 
thresholds increasing by approximately 1.5; 46; 56; 15; and 20 dB for 
the LF, MF, HF, phocid pinnipeds (underwater) (PW), and otariid 
pinnipeds (underwater) (OW) hearing groups, respectively, above the 
baseline threshold level (Table 18). Based on simple spherical 
spreading (i.e., transmission loss based on 20 x log10 [range 
{m{time} ]), all hearing groups except LF cetaceans would need to 
remain within 22 ft (7 m) for the duration of an entire LFA sonar ping 
(60 seconds) to potentially experience PTS. LF cetaceans would need to 
remain at the greatest distance from the transmitting LFA sonar before 
experiencing the onset of injury, 135 ft (41 m) for this example. 
Consequently, if mitigation is tied to preventing the same type of 
impact (PTS), the distance at which SURTASS LFA sonar transmissions 
should be mitigated for marine mammals would be the distance associated 
with LF cetaceans, as the mitigation range would be the greatest for 
this hearing group. Any mitigation measure developed for LF cetaceans 
based on PTS onset would be highly conservative for any other marine 
mammals potentially exposed to SURTASS LFA sonar transmissions.

                         Table 18--TTS and PTS Onset Thresholds for Non-Impulsive Sounds
----------------------------------------------------------------------------------------------------------------
                                                                                                Cumulative sound
                                                                                                 exposure level
                                                          Cumulative sound   Cumulative sound  threshold for PTS
                     Hearing group                         exposure level     exposure level        \1\ with
                                                         threshold for TTS  threshold for PTS      weighting
                                                              \1\ (dB)           \1\ (dB)       function applied
                                                                                                 at 300 Hz (dB)
----------------------------------------------------------------------------------------------------------------
Low-frequency cetaceans................................                179                199              200.5
Mid-frequency cetaceans................................                178                198                244
High-frequency cetaceans...............................                153                173                229
Phocid pinnipeds (PW) (Underwater).....................                181                201                216
Otariid pinnipeds (OW) (Underwater)....................                199                219               239
----------------------------------------------------------------------------------------------------------------
\1\ Referenced to 1 [mu]Pa\2\s; weighted according to appropriate auditory weighting function.

    To calculate the SPL of these SELcum thresholds it is 
necessary to account for the weighting function, as previously 
explained, and the duration of exposure (10 x log (duration in 
sections)). Applying the duration of a single ping of SURTASS LFA sonar 
(60 sec) results in 17.8 dB (i.e., (10 log (60)), which is subtracted 
from the weighted SELcum value of 200.5 dB for LF cetaceans 
(199 dB PTS onset threshold plus 1.5 dB associated with LF cetacean 
weighting function at 300 Hz), for an SPL of 182.7 dB re: 1 [micro]Pa 
rms. The distance to the 182.7 dB re: 1 [micro]Pa rms isopleth would be 
slightly smaller than that associated with the previously used 180 dB 
re: 1 [micro]Pa rms isopleth. To convert the SELcum 
threshold to SPL for two pings of SURTASS LFA sonar, one would need to 
account for this increased duration of exposure (10 x log (120 
seconds)), which results in 20.8 dB being subtracted from the weighted 
SELcum value of 200.5 dB for LF cetaceans, for an SPL of 
179.7 dB re: 1 [micro]Pa rms. The resulting SPL for exposure of an LF 
cetacean to two pings of SURTASS LFA sonar (179.7 dB re: 1 [micro]Pa 
rms) is very close to the 180 dB re: 1 [micro]Pa rms received level, on 
which previous mitigation measures were based. This exposure scenario 
is unlikely, as a marine mammal would have to remain close, <200 ft (61 
m), to the transmitting LFA sonar array for an extended period, 
approximately 20 minutes, to experience two full pings (one ping every 
10 min). Although this is an unlikely scenario, the Navy will retain 
and NMFS will require a mitigation zone that is basically equivalent to 
the previous zone based on 180 re: 1 [micro]Pa rms received level as 
the current mitigation zone for SURTASS LFA sonar training and testing 
activities in this rule, as described below.
    In previous rules, prior to commencing and during SURTASS LFA sonar 
training and testing transmissions, the Navy determined (in real time) 
the propagation of LFA sonar signals in the ocean and the distance from 
the SURTASS LFA sonar source to the 180 dB re: 1 [mu]Pa rms isopleth 
(See Description of Real-Time SURTASS LFA Sonar Sound Field Modeling 
section of the application). The 180 dB re: 1 [mu]Pa rms isopleth 
defined the extent of the LFA sonar mitigation zone for marine mammals 
around the surveillance vessel. If a marine mammal entered the LFA 
sonar mitigation zone (or the 1-km buffer previously required by NMFS, 
as described below), the Navy implemented a suspension of SURTASS LFA 
sonar transmissions. This measure was included in prior rules to reduce 
or alleviate the likelihood that marine mammals would be exposed to 
levels of sound that may result in injury (PTS). However, due to the 
updated criteria in NMFS' 2018 Acoustic Technical Guidance, this 180 dB 
mitigation zone would not only preclude PTS, but almost all TTS and 
more severe behavioral reactions as well. While not an expansion of the 
mitigation, the best available science indicates the mitigation zone is 
more effective at reducing PTS and TTS than previously considered in 
prior authorizations for SURTASS LFA sonar.
    The Navy modeling of the sound field in near-real time conditions 
provided the information necessary to calculate the mitigation zone for 
which delay or suspension of LFA sonar transmissions would occur. 
Acoustic model updates were nominally made every 12 hrs, or as 
meteorological or oceanographic conditions changed. If a marine mammal 
entered the calculated threshold distance (plus its associated buffer 
distance), the sonar operator notified the senior military member in 
charge, who would order the delay or suspension of transmissions. If it 
were

[[Page 40182]]

predicted that the SPL threshold distances would change within the next 
12-hr period, the senior military member in charge would also be 
notified in order to take the necessary action to ensure that the sound 
field criteria would not be exceeded.
    As an added protective measure, NMFS previously required the Navy 
to include a ``buffer zone'' that extended an additional 1 km (0.62 mi; 
0.54 nm) beyond the Navy's proposed 180 dB re: 1 [mu]Pa rms isopleth 
LFA sonar mitigation zone. This buffer typically coincides with the 
full detection range of the HF/M3 active sonar for mitigation 
monitoring (approximately 2 to 2.5 km; 1.2 to 1.5 mi; 1.1 to 1.3 nmi). 
Thus, implementation of this additional 1 km buffer zone increases the 
shutdown zone around the LFA sonar array and vessel and, given the 
highly effective monitoring capabilities (described below), ensures 
that no marine mammals will be exposed to an SPL greater than 
approximately 174 dB re: 1 [mu]Pa rms. In past applications, the Navy 
has noted that this additional mitigation is practicable and the Navy 
has implemented this measure in previous authorizations. In addition, 
as noted above for the 180 dB mitigation zone, based on new scientific 
information and updated criteria in NMFS' 2018 Acoustic Technical 
Guidance, this buffer mitigation is likely even more effective at 
avoiding the likelihood of PTS and reducing the degree of TTS than 
previously known when analyzed and employed in previous authorizations. 
The proposed 2,000 yd (1.83 km) single fixed mitigation zone would 
cover virtually all of the previous combined mitigation/buffer zone of 
nominally 1.08 nmi (2 km), since the difference between 2,000 yd and 2 
km is only about 187 yd (or 0.09 nmi (167 m)). Likewise, the difference 
in the sound field of the combined mitigation/buffer zone of 2,000 yd 
(1.83 km) versus 1.08 nmi (2,187 yd; 2 km) would also be negligible. At 
2,000 yd (1.83 km), modeling shows that the received level would be 
174.75 dB while at 1.08 nmi (2 km), the received level would be 173.98 
dB, which is a difference of only 0.77 dB. This very small difference 
in received level would not be perceptible to a marine mammal.
    In summary, Navy proposed, and NMFS will require, a single, fixed, 
combined mitigation/buffer zone for SURTASS LFA sonar training and 
testing activities to standardize and simplify implementation of this 
monitoring requirement using standard Navy metrics (yards not meters). 
This measure will be effective mitigation in all acoustic environments, 
even in the rare event of a strong acoustic duct in which the volume of 
water ensonified to 180 dB re: 1 [mu]Pa rms could exist at a horizontal 
distance somewhat greater than 0.54 nmi (1 km) (DoN, 2001). With the 
mitigation zone of 2,000 yd (1.83 km), there is no potential for 
animals to be exposed to received levels greater than 180 dB re: 1 
[mu]Pa rms, or levels above the new injury (PTS) thresholds identified 
in NMFS' 2018 Acoustic Technical Guidance, and, therefore, marine 
mammals are protected from both acoustic injury and more severe 
occurrences of Level B harassment.
Visual Mitigation Monitoring
    Visual monitoring will consist of daytime observations for marine 
mammals from the bridge of SURTASS LFA sonar vessels by lookouts 
(personnel trained in detecting and identifying marine mammals). Navy 
shipboard lookouts are highly qualified and experienced observers of 
the marine environment. Their operational duties require that they 
report all objects sighted on the water surface to the senior military 
member in charge (e.g., trash, a periscope, marine mammals, sea 
turtles) and all disturbances (e.g., surface disturbance, 
discoloration) that may be indicative of a threat to the vessel and its 
crew. The objective of visual mitigation monitoring is to maintain 
location, distance, and movement information about marine mammals 
observed to ensure that none approach close enough to enter the 2,000-
yd LFA mitigation/buffer zone.
    Daylight is defined as 30 min before sunrise until 30 min after 
sunset. Visual monitoring will begin 30 min before sunrise or 30 min 
before the Navy deploys the SURTASS LFA sonar array. Lookouts will 
continue to monitor the area until 30 min after sunset or continue to 
monitor for at least 15 min after completion of the SURTASS LFA sonar 
training and testing transmission.
    The lookouts will maintain a topside watch and marine mammal 
observation log during daytime activities that employ SURTASS LFA sonar 
in the active mode. These trained monitoring personnel maintain a 
topside watch and scan the water's surface around the vessel 
systematically with standard binoculars (7x) and with the naked eye. If 
the lookout sights a possible marine mammal, the lookout will use big-
eye binoculars (25x) to confirm the sighting and potentially identify 
the marine mammal species. Lookouts will enter numbers and 
identification of marine mammals sighted into the log, as well as any 
unusual behavior. A designated ship's officer will monitor the conduct 
of the visual watches and periodically review the log entries.
    If a lookout observes a marine mammal outside of the 2,000-yd LFA 
sonar mitigation zone, the lookout will notify the senior military 
member in charge of the watch. The senior military member in charge 
shall then notify the HF/M3 active sonar operator to determine the 
range and projected track of the marine mammal. If the HF/M3 sonar 
operator or the lookout determines that the marine mammal will pass 
within the 2,000-yd LFA sonar mitigation zone, the senior military 
member in charge shall order the delay or suspension of SURTASS LFA 
sonar training and testing transmissions when the animal enters the 
2,000-yd LFA sonar mitigation zone to prevent Level A harassment as 
well as reduce the potential for TTS and more severe behavioral 
responses.
    If a lookout observes a marine mammal anywhere within the 2,000-yd 
LFA mitigation/buffer zone (required by NMFS), the senior military 
member in charge will be notified so that the LFA sonar training and 
testing transmissions will be immediately shut down or suspended. The 
lookout will enter his/her observations about sighted marine mammals 
into the log: date/time; vessel name; geographic coordinates/position; 
type and number of marine mammals observed; assessment basis (i.e., 
observed injury or behavioral response); bearing from vessel; whether 
activities were delayed, suspended, or terminated; and relevant 
narrative information.
    Marine mammal biologists who are qualified in conducting at-sea 
marine mammal visual monitoring from surface vessels will train and 
qualify designated ship personnel to conduct at-sea visual monitoring. 
This training may be accomplished either in-person or via video 
training.
Passive Acoustic Mitigation Monitoring
    For the second of the three-part mitigation monitoring measures, 
the Navy will conduct passive acoustic monitoring using the SURTASS 
towed horizontal line array to detect vocalizing marine mammals as an 
indicator of their presence. This system serves to augment the visual 
and active sonar detection systems, and is deployed and operated at all 
times in which the LFA sonar system could be utilized. If a passive 
acoustic technician detects a vocalizing marine mammal that may be 
potentially affected by LFA sonar prior to or during transmissions, the 
technician will notify the senior military member in charge who will 
immediately alert the HF/M3 active sonar operators and the lookouts. 
The senior military member in charge

[[Page 40183]]

shall order the delay or suspension of LFA sonar transmissions when the 
animal enters the 2,000-yd LFA mitigation/buffer zone as detected by 
either the HF/M3 sonar operator or the lookouts. The passive acoustic 
technician will record all contacts of marine mammals in a log.
Active Acoustic Mitigation Monitoring
    Active acoustic monitoring uses the high-frequency marine mammal 
monitoring (HF/M3) sonar to detect, locate, and track marine mammals 
that could pass close enough to the SURTASS LFA sonar array to enter 
the 2,000-yd LFA sonar mitigation zone. HF/M3 acoustic monitoring may 
be used at all times of the day or night and begins 30 min before the 
first LFA sonar transmission of a given training or testing activity is 
scheduled to commence and continues until the Navy terminates LFA sonar 
transmissions.
    If the HF/M3 sonar operator detects a marine mammal contact outside 
the 2,000-yd LFA sonar mitigation zone, the HF/M3 sonar operator will 
determine the range and projected track of the marine mammal. If the 
operator determines that the marine mammal will pass within the 2,000-
yd LFA sonar mitigation zone, he/she will notify the senior military 
member in charge. The senior military member in charge will then 
immediately order the delay or suspension of LFA sonar training and 
testing transmissions when the animal is predicted to enter the 2,000-
yd LFA sonar mitigation zone.
    If the HF/M3 sonar operator detects a marine mammal within the 
2,000-yd LFA mitigation zone, he/she will notify the senior military 
member in charge who will immediately order the delay or suspension of 
training and testing transmissions. The HF/M3 sonar operator will 
record all contacts of marine mammals into the log.
    Prior to full-power operations of the HF/M3 active sonar during 
SURTASS LFA sonar training and testing activities, the Navy will ramp 
up the HF/M3 sonar power level over a period of 5 min from the source 
level of 180 dB re 1 [mu]Pa at 1 m in 10-dB increments until the HF/M3 
system attains full power (if required) to ensure that there are no 
inadvertent exposures of marine mammals to received levels greater than 
180 dB re 1 [mu]Pa rms from the HF/M3 sonar. The Navy will not increase 
the HF/M3 sonar source level if any of the three monitoring methods 
detects a marine mammal during ramp-up. Ramp-up of the HF/M3 active 
sonar may continue once marine mammals are no longer detected within 
the 2,000-yd LFA mitigation zone by any of the three monitoring 
methods.
    In situations where the HF/M3 sonar system has been powered down 
for more than 2 min during a training and testing event, the Navy will 
ramp up the HF/M3 sonar power level over a period of 5 min from the 
source level of 180 dB re: 1 [mu]Pa at 1 m in 10-dB increments until 
the system attains full power.
NMFS' Additional 1-km Buffer Zone Around OBIAs
    Similar to the previously-required 1-km buffer around the LFA Sonar 
Mitigation Zone, NMFS is requiring the Navy to include a ``buffer 
zone'' that extends an additional 1 km (0.62 mi; 0.54 nm) beyond the 
seaward boundary of any OBIA (discussed in ``Geographic Restrictions'' 
section immediately below). The Navy has noted that this additional 
mitigation is practicable and has implemented this measure in previous 
authorizations. In addition, as noted above for the 180-dB mitigation 
zone, based on new scientific information and updated criteria in NMFS' 
2018 Acoustic Technical Guidance, this 1-km buffer mitigation is more 
effective at avoiding PTS and reducing TTS than previously known when 
analyzed and employed in previous authorizations.
Geographic Restrictions
    As noted above, the Navy will implement geographic restrictions for 
SURTASS LFA sonar training and testing activities that entail 
restricting SURTASS LFA sonar activities within these designated areas 
such that:
    (a) The received level of SURTASS LFA sonar transmissions during 
training and testing events will not exceed 180 dB re: 1 [mu]Pa rms 
within 1 km seaward of any OBIA boundary, during the indicated periods 
of biological importance.
    (b) No more than 25 percent of the authorized amount (transmission 
hours) of SURTASS LFA sonar for training and testing will be used 
within 10 nmi (18.5 km) of any single OBIA during any year (no more 
than 124 hours in years 1-4 and 148 hours in years 5-7) unless the 
following conditions are met: Should national security present a 
requirement to conduct more than 25 percent of authorized hours of 
SURTASS LFA sonar within 10 nmi (18.5 km) of any single OBIA during any 
year, naval units will obtain permission from the appropriate 
designated Command authority prior to commencement of the activity. The 
Navy will provide NMFS with notification as soon as is practicable and 
include the information (e.g., sonar hours) in its annual activity 
reports submitted to NMFS.
    (c) The received level of SURTASS LFA sonar transmissions will not 
exceed 180 dB re: 1 [mu]Pa rms within the Coastal Standoff Zone (22 km 
(12 nmi) from any land).
    (d) No activities with the SURTASS LFA sonar system will occur 
within territorial seas of foreign nations, which are areas up to 12 
nmi from shore, depending on the distance that individual nations 
claim.
    (e) No activities with the SURTASS LFA sonar system will occur 
within the waters of Penguin Bank, Hawaii (defined as water depth of 
600 ft (183 m)), and ensonification of Hawaii state waters (out to 3 
nmi) will not exceed 145 dB re: 1 [mu]Pa rms.
    As with previous rulemakings for SURTASS LFA sonar, this rulemaking 
contains a consideration of geographic restrictions, including OBIAs. 
However, whereas the Navy previously considered SURTASS LFA sonar 
activities worldwide, it has narrowed the geographic scope of its 
current application to reflect only those areas of the world's oceans 
where the Navy anticipates conducting covered SURTASS LFA sonar 
activities (i.e., training and testing in the SURTASS LFA Study Area in 
the central and western North Pacific and eastern Indian Oceans). 
Therefore, consideration of geographical restrictions is also limited 
to the SURTASS LFA Study Area in the central and western North Pacific 
and eastern Indian Oceans.

Offshore Biologically Important Areas--Background

    Given the unique operational characteristics of SURTASS LFA sonar, 
Navy and NMFS developed the concept of geographical restrictions for 
SURTASS LFA sonar in the SURTASS LFA Sonar FOEIS/EIS (DoN, 2001) to 
include: Delineating a 12 nmi coastal standoff zone where received 
levels from SURTASS LFA sonar will not exceed 180 dB re: 1 [mu]Pa rms, 
and designating OBIAs, where warranted, for areas beyond this coastal 
standoff zone, wherein received levels will not exceed 180 dB re: 1 
[mu]Pa rms. The coastal standoff zone and OBIAs are intended to reduce 
the likelihood and/or degree of impacts on affected marine mammal 
species or stocks. As noted in the 2012 final rule (77 FR 50290; August 
20, 2012), over 80 percent of the existing and potential marine 
protected areas reviewed were within 12 nmi from a coastline, 
indicating the effectiveness of the coastal standoff as one of the 
primary mitigation measures for

[[Page 40184]]

reducing potential impacts to marine mammals. OBIAs expand upon this 
protection by avoiding or minimizing impacts in areas beyond the 
coastal standoff zone where marine mammals are known to engage in 
specific behaviors that may lead to more severe impacts if interrupted; 
known to congregate in higher densities; and/or known to have a limited 
range and small abundance that creates more vulnerability for the stock 
as a whole. These criteria are important when determining whether 
mitigation would be likely to reduce the probability or severity of 
effects to individuals that would translate to minimization of impacts 
at the population level under the LPAI standard. Limiting LFA sonar 
activities in these important areas is expected to limit the likelihood 
and/or degree of species or stock effects by minimizing the chances 
that the activity will result in detrimental energetic effects to 
individuals (such as those that could occur in known feeding areas) or 
direct interference in breeding or mother/young interactions (such as 
those that could occur in reproductive or nursing areas) that could 
result in reductions in reproductive success or survivorship.
    Three OBIAs were identified in the 2001 SURTASS LFA FOEIS/EIS: 200 
m isobaths of the east coast of North America; Costa Rica Dome; and 
Antarctic Convergence Zone. In 2007, the Navy published a supplemental 
FEIS/FOEIS that designated six new OBIAs in addition to the three OBIAs 
that were designated in the 2001 SURTASS LFA FOEIS/FEIS. The criteria 
for identifying OBIAs in the 2001 and 2007 rules were originally 
defined in the 2001 SURTASS LFA Sonar FOEIS/EIS (Subchapter 2.3.2.1) as 
areas of the world's oceans outside of the geographic stand-off 
distance (greater than 22 km (12 nmi)) from a coastline (including 
islands) where marine animals of concern (those animals listed under 
the ESA and/or marine mammals) carry out biologically important 
activities, including migration, foraging, breeding, and calving.
    For the 2012 rule, the Deputy Assistant Secretary of the Navy for 
Environment (DASN(E)) determined that the purpose of NEPA and Executive 
Order 12114 would be furthered by the preparation of an additional 
supplemental analysis related to the employment of SURTASS LFA sonar. 
Accordingly, the DASN(E) directed that an SEIS/SOEIS (among other 
things) provide further analysis of potential additional OBIAs in 
regions of the world where the Navy intended to use the SURTASS LFA 
sonar systems.
    In parallel, for the 2012 rule, NMFS, with Navy input, developed a 
new process and screening criteria for determining an area's 
eligibility to be considered as an OBIA nominee for marine mammals. 
Those screening criteria were: (1) Areas with: (a) High densities of 
marine mammals; or (b) Known/defined critical habitat, breeding/calving 
grounds, foraging grounds, migration routes; or (c) Small, distinct 
populations of marine mammals with limited distributions; and (2) Areas 
that are outside of the coastal standoff distance and within potential 
operational areas for SURTASS LFA (i.e., greater than 22 km (13.6 mi; 
12 nmi) from any shoreline and not in polar regions).
    For the 2012 SURTASS LFA FSEIS/SOEIS and 2012 rule, NMFS also 
developed and implemented a robust, systematic screening process for 
reviewing existing and potential marine protected areas against the 
OBIA criteria, based on the World Database on Protected Areas (WDPA, 
2009), Hoyt (2005), and prior SURTASS LFA sonar OBIAs. This process 
produced a preliminary list of 403 OBIA nominees. As noted above, and 
stated in the 2012 Final Rule (77 FR 50290; August 20, 2012), the vast 
majority of the areas reviewed as potential OBIAs were within 12 nmi 
from a coastline and therefore already afforded protection due to the 
coastal standoff zone, indicating the effectiveness of the coastal 
standoff zone as one of the primary mitigation measures for reducing 
potential impacts. The remaining areas were broadly evaluated under the 
OBIA criteria and, after review, 73 potential OBIAs were considered by 
the Navy and NMFS.
    After the list of potential OBIAs was developed based on 
information at a broad scale, each of these areas was evaluated at a 
finer scale to determine whether they qualified for designation as an 
OBIA. Further analysis of the biological evidence and robustness of the 
data for each of these recommendations included ranking them in 
categories using a numbering system ranging from 0 to 4. Any of the 
nominees that received a ranking of 2 or higher were eligible for 
continued consideration as an OBIA nominee. A rank score of 2 for 
designation criteria or for OBIA boundary considerations indicated that 
the designation was inferred from habitat suitability models (non-peer 
reviewed), expert opinion, regional expertise, or ``gray literature'' 
(inferred from analyses conducted for purposes other than quantifying 
OBIA criteria or boundary; see DoN (2012), Section 4.5.2.1). Thus, even 
areas with somewhat limited data were eligible for further 
consideration as an OBIA.
    The systematic process described here was developed in order to 
support an orderly and manageable expert review and to ensure some 
definable information quality in the identification of OBIAs. As a 
result of this process, 45 areas ranked a 2 or higher.
    Although not part of the initial screening criteria for the 2012 
rulemaking, consideration of marine mammal hearing frequency 
sensitivity led NMFS to screen out areas that qualified solely on the 
basis of their importance for mid- or high-frequency hearing 
specialists in past rulemakings. This was due to the fact that the LFA 
sound source is below the range of best hearing sensitivity for MF and 
HF odontocete hearing specialists. Using the example of harbor 
porpoises, this means that a sound with a frequency less than 1 kHz 
would need to be significantly louder (more than 50 dB louder) than a 
sound in their area of best sensitivity (around 100 kHz) in order for 
them to hear it. Additionally, during the 1997 to 1998 SURTASS LFA 
Sonar Low Frequency Sound Scientific Research Program (LFS SRP), 
numerous odontocete and pinniped species (i.e., MF and HF hearing 
specialists) were sighted in the vicinity of the sound exposure tests 
and showed no immediately obvious responses or changes in sighting 
rates as a function of source conditions, which likely produced 
received levels similar to those that produced minor short-term 
behavioral responses in the baleen whales (i.e., LF hearing 
specialists). NMFS reasoned that MF and HF odontocete hearing 
specialists have such reduced sensitivity to the LFA sonar source that 
limiting ensonification in OBIAs for those animals would not afford 
protection beyond that which is already achieved by implementing a 
shutdown when any marine mammal enters the LFA mitigation zone. 
Therefore, consideration of marine mammal frequency sensitivity led 
NMFS to screen out areas that qualified solely on the basis of their 
importance for MF or HF specialists.
    In addition to the considerations above, NMFS reviewed Hoyt (2011), 
which was an update and revision of Hoyt's 2005 earlier work, along 
with areas recommended in public comments received on the 2012 SURTASS 
LFA DSEIS/SOEIS. As a result of this further analysis, NMFS developed a 
list of OBIAs, which were then further considered in the context of 
practicability.
    In response to public comments on the 2012 proposed rule, NMFS also

[[Page 40185]]

reevaluated its preliminary decision not to include areas that met the 
criteria for sperm whales and pinnipeds (because they were not 
considered LF specialists), and ultimately determined such areas would 
be appropriate for OBIA designation where information established by 
the criteria were met, and in fact noted that one OBIA (Patagonia 
Shelf) had already been identified for elephant seals. While no OBIAs 
had been identified for sperm whales, NMFS committed to considering 
sperm whales in future analyses should supporting information become 
available.
    As part of the 2017 SURTASS LFA DSEIS/SOEIS, and as part of the 
2017 rulemaking process, NMFS and Navy continued their evaluation of 
OBIAs. As a result of that work, NMFS and the Navy revised boundaries 
and designated seven more OBIAs, for a total of 29 OBIAs that were 
identified and made part of the NDE, under which the Navy is currently 
conducting SURTASS LFA sonar activities. Two of these OBIAs include 
protection for sperm whales (OBIA #28, Perth Canyon; and OBIA #29, 
Southwest Australia Canyons).
    Since 2012, the Navy and NMFS have maintained an ``OBIA Watchlist'' 
of potential marine areas in the Study Area for which information or 
data have not been sufficient to designate as OBIAs, and reviewed new 
literature to determine if additional areas should be added to the list 
of potential areas. As part of the Adaptive Management process (see 
Adaptive Management section), the OBIA Watchlist is periodically 
evaluated as additional information becomes available to determine if 
the new information provides adequate support under one of the OBIA 
biological criteria. NMFS refers the reader to the 2019 SURTASS LFA 
FSEIS/SOEIS, Chapter 5 and Appendix C, for more detail on the analysis 
of potential OBIAs. As part of the ongoing Adaptive Management process 
and in preparation for the 2019 SURTASS LFA FSEIS/SOEIS, NMFS and Navy 
reviewed the OBIA Watchlist and other new information to determine the 
potential for additional OBIAs or expansion of existing OBIAs within 
the SURTASS LFA Study Area.

Offshore Biologically Important Areas--Current Rulemaking

    For the 2019 SURTASS LFA FSEIS/SOEIS and this final rule, the 
following biological criteria, geographic criteria, and LF hearing 
sensitivity factors were considered in the identification of OBIAs:
    Biological Criteria--As with other biological criteria, critical 
habitat is considered as one of the possible factors in the OBIA 
process, but designation as critical habitat does not necessarily 
comport with designation as an OBIA due to differences in the intent of 
these designations. Critical habitat is defined and used in the ESA and 
includes specific geographic areas that contain features essential to 
the conservation of an endangered or threatened species, including 
areas that are not currently occupied by the relevant species. However, 
as stated above, the intent of OBIA designation is to expand upon the 
coastal standoff zone, and provide protection from potential SURTASS 
LFA sonar impacts by avoiding or minimizing impacts in areas beyond the 
coastal standoff zone where marine mammals are known to engage in 
specific behaviors that may lead to more severe impacts if interrupted; 
known to congregate in higher densities; and/or known to have a limited 
range and small abundance that creates more vulnerability for the stock 
as a whole. Therefore, at least one of the following biological 
criteria must be met for a marine area to be considered as a marine 
mammal OBIA for SURTASS LFA sonar. When direct data relevant to one of 
the following are limited, other available data and information may be 
used if those data and information, either alone or in combination with 
limited direct data, are sufficient to establish that at least one of 
the biological criteria are present:
     Known Breeding/Calving or Foraging Ground, or Mitigation 
Route--an area representing a location of known biologically important 
activities, including defined breeding or calving areas, foraging 
grounds, or migration routes. Potential designation under this 
criterion is indicative that these areas are concentrated areas for at 
least one biologically important activity. ``Concentrated'' means that 
more of the animals are engaged in the particular behavior at the 
location (and perhaps time) than are typically engaged in that behavior 
elsewhere.
     Small, Distinct Populations of Marine Mammals with Limited 
Distributions--geographic areas in which small, distinct populations of 
marine mammals occur and whose distributional ranges are limited.
     High Densities--an area of high density for one or more 
species of marine mammal. High density areas are those marine waters 
where the density, within a definable area (and potentially time), 
measurably and meaningfully exceeds the average density of the species 
or stock within the region. The exact basis for the identification of 
high density areas may differ across species/stocks and regions/scales, 
depending on the available information and should be evaluated on a 
stock-by-stock basis, although combining species or stocks may be 
appropriate in some situations. The best source for this type of 
determination are publically-available, direct measurements from survey 
data.
    Geographic Criteria--For a marine area to be eligible for 
consideration as an OBIA for marine mammals, the area must be located 
where training and testing activities of SURTASS LFA sonar would occur 
(i.e. in the Study Area) and cannot be located within 12 nm (22 km) of 
any emergent land including islands or island systems (i.e., must be 
outside of the coastal standoff zone, which already receives the same 
protection as OBIAs).
    LF Hearing Sensitivity--The frequencies produced by SURTASS LFA 
sonar transmissions are well below the frequency range of best hearing 
sensitivity for most odontocetes and pinnipeds based on the measured 
hearing thresholds (Au and Hastings, 2008; Houser et al., 2008; 
Kastelein et al., 2009; Mulsow and Reichmuth, 2010; NMFS, 2018; Nedwell 
et al., 2004; Richardson et al., 1995; Southall et al., 2007; Southall 
et al., 2019). The intent of OBIAs is to protect those marine mammal 
species, such as baleen whales, most likely to hear and be affected by 
LFA sonar transmissions and to provide them with additional protections 
during periods when they are conducting biologically significant 
activities. Thus, the primary focus of the OBIA mitigation measure is 
on LF hearing specialist species. However, OBIAs have been designated 
for non-LF hearing specialists, such as elephant seals and sperm 
whales, since the available hearing data for these species indicate an 
increased sensitivity to LF sound (compared to most odontocetes and 
pinnipeds).
    The biological criteria considered in the identification of OBIAs 
have changed since the 2001 SURTASS LFA FOEIS/EIS (and as continued in 
the 2007 SURTASS LFA SEIS) in two respects. First, under the 2001 
SURTASS LFA FOEIS/EIS, 2007 SURTASS LFA SEIS, and the 2007 final rule, 
an area could be designated as an OBIA only if it met a conjunctive 
test of being an area where marine mammals congregate (1) in high 
densities, and (2) for a biologically important purpose. The current 
scheme is more protective because any one of the biological criteria 
alone could be a sufficient basis for designation as an OBIA if it also 
meets the geographic criterion of falling outside of 12 nmi (22 km) 
from any coastline. Second, the current biological criteria now include 
``small, distinct

[[Page 40186]]

populations with limited distribution,'' which also could, standing 
alone, be a basis for designation.
    The 2017 NDE for SURTASS LFA sonar lists the 29 marine mammal OBIAs 
and their effective periods as geographic mitigation with which the 
Navy must comply for SURTASS LFA sonar activities. These OBIAs resulted 
from analyses conducted as part of the 2017 SURTASS LFA SEIS/SOEIS and 
application for rulemaking, and retained existing OBIAs; revised/
expanded existing OBIAs; and added new OBIAs to those defined as part 
of the 2012 SURTASS LFA sonar rule (also see the 2019 SURTASS LFA 
FSEIS/SOEIS, Chapter 5, Section 5.3.6.2 and Appendix C for more detail 
on OBIAs). Of these 29 OBIAs, four are located within the current 
SURTASS LFA sonar Study Area (OBIA 16, Penguin Bank, Hawaiian Islands 
Humpback Whale NMS; OBIA 20, Northern Bay of Bengal and Head of Swatch-
of-No-Ground; OBIA 26, Offshore Sri Lanka; and OBIA 27, Camden Sound/
Kimberly Region), as indicated in Table 19, below.

                   Table 19--Marine Mammal OBIAs Observed for SURTASS LFA Sonar During the NDE
----------------------------------------------------------------------------------------------------------------
                                                                          Relevant  low-
         OBIA No.              Name of OBIA      Location/water  body    frequency  marine      Effectiveness
                                                                          mammal  species      seasonal period
----------------------------------------------------------------------------------------------------------------
16.......................  Penguin Bank,         North-Central         Humpback whale......  November through
                            Hawaiian Islands      Pacific Ocean.                              April, annually.
                            Humpback Whale NMS.
20.......................  Northern Bay of       Bay of Bengal/        Bryde's whale.......  Year-round.
                            Bengal and Head of    Northern Indian
                            Swatch-of-No-         Ocean.
                            Ground (SoNG).
26.......................  Offshore Sri Lanka..  North-Central Indian  Blue whale..........  December through
                                                  Ocean.                                      April, annually.
27.......................  Camden Sound/         Southeast Indian      Humpback whale......  June through
                            Kimberly Region.      Ocean; northwestern                         September,
                                                  Australia.                                  annually.
----------------------------------------------------------------------------------------------------------------

    Since the 2017 SURTASS LFA SEIS/SOEIS and NDE for SURTASS LFA 
sonar, analysis and assessment of marine areas as potential OBIAs has 
continued. The Navy and NMFS have conducted a comprehensive assessment 
of the available scientific literature, data, and information on 
potential marine areas in the SURTASS LFA Study Area to determine their 
potential as OBIAs. Because this rulemaking and the 2019 SURTASS LFA 
FSEIS/SOEIS have a narrowed geographic scope for SURTASS LFA sonar 
training and testing activities, review of OBIAs was similarly scoped 
to reflect only the current Study Area. Navy and NMFS' comprehensive 
assessment of marine areas as potential OBIAs included review of the 
OBIA Watchlist for areas located within the Study Area as well as a 
thorough review of the Important Marine Mammal Areas (IMMAs), 
Ecologically or Biologically Significant Marine Areas (EBSAs), IUCN 
Green List of Protected and Conserved Areas, as well as marine areas 
recommended in public comments on the 2019 SURTASS LFA DSEIS/SOEIS (see 
Chapter 7 of the 2019 SURTASS LFA FSEIS/SOEIS) and on our MMPA proposed 
rule (84 FR 7186; March 1, 2019). For this final rule, we have applied 
the OBIA biological criteria, geographic criteria, and hearing 
sensitivity factor, as well as the practicability criterion to the 
potential OBIAs. A summary of the number and types of marine areas 
assessed as potential OBIAs for SURTASS LFA sonar and their location 
relative to the Study Area and coastal standoff range (12 nmi) and 
relevancy for marine mammals is provided in Table 20. While we provide 
a summary of the OBIA analysis here, we direct the reader to Chapter 5 
and Appendix C of the 2019 SURTASS LFA FSEIS/SOEIS for the complete 
analysis of all considered OBIA areas.

 Table 20--Number and Types of Marine Areas Assessed as Potential Offshore Biologically Important Areas (OBIAs)
  for SURTASS LFA Sonar, and Their Location Relative to the Study Area and Coastal Standoff Range (12 nmi) and
                                           Relevancy to Marine Mammals
----------------------------------------------------------------------------------------------------------------
                                                                                     Number of
                                                                                  marine  mammal
                                                     Number of       Number of         areas
                                                   marine areas    marine areas     located in       Number of
                                   Total number       located      in LFA study     study area     marine areas
       Marine area region          marine areas    within study   area  relevant    and outside       further
                                                   area \1\ for     to  marine       \2\  the        assessed
                                                    SURTASS LFA       mammals         coastal
                                                       sonar                         standoff
                                                                                       range
----------------------------------------------------------------------------------------------------------------
                                              OBIA Watchlist Areas
----------------------------------------------------------------------------------------------------------------
Western North Pacific Ocean.....               3               3               3               3               3
Central Indian Ocean............               1               1               1               1               0
rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
    Total OBIA Watchlist........               4               4               4               4               3
----------------------------------------------------------------------------------------------------------------

[[Page 40187]]

 
                                            U.S. ESA Critical Habitat
----------------------------------------------------------------------------------------------------------------
Central North Pacific Ocean.....               2               2               2               2               2
----------------------------------------------------------------------------------------------------------------
                           UNEP Ecologically or Biologically Significant Areas (EBSAs)
----------------------------------------------------------------------------------------------------------------
Northeast Indian Ocean..........              10              10               5               3               3
South and Western Indian Ocean..              39               5               1               0               0
East Asian Seas.................              34              31               9               6           \3\ 7
North Pacific Ocean.............              20               6               4               4               4
Western South Pacific Ocean.....              26               2               0               0               0
                                 -------------------------------------------------------------------------------
    Total EBSAs.................             129              54              19              13              14
----------------------------------------------------------------------------------------------------------------
                               IUCN WCPA-SSC Important Marine Mammal Areas (IMMAs)
----------------------------------------------------------------------------------------------------------------
Pacific Islands.................              15               3               3               2               2
Southeast Asian Seas and                      30              20              20               9               8
 Northeast Indian Ocean.........
                                 -------------------------------------------------------------------------------
    Total IMMAs.................              45              23              23              11              10
----------------------------------------------------------------------------------------------------------------
                                IUCN Green List of Protected and Conserved Areas
----------------------------------------------------------------------------------------------------------------
Asian Pacific...................              11               0               0               0               0
----------------------------------------------------------------------------------------------------------------
                  Recommended in Public Comments on Draft SEIS/SOEIS and MMPA Proposed Rule \4\
----------------------------------------------------------------------------------------------------------------
Western North Pacific Ocean.....              41              40              40              21              21
Eastern Indian Ocean............              52              52              52              27              27
rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
    Total Comment                             93              92              92              48              48
     Recommendations............
----------------------------------------------------------------------------------------------------------------
\1\ At least part of marine area located within study area for SURTASS LFA sonar.
\2\ At least part of the marine area is located outside the LFA coastal standoff range.
\3\ Even though the Ogasawara Islands EBSA is located within the coastal standoff range, due to its importance
  to the endangered humpback whale DPS, this area was further considered.
\4\ The number of marine areas received in Public Comments includes the newly designated IMMAs (SE Asian Seas
  and NE Indian Ocean) as well as duplicate marine areas, since some of the same marine areas were noted in
  comments received both for the 2018 SURTASS LFA DSEIS/SOEIS and MMPA Proposed Rule. Additionally, some of the
  recommended marine areas were EBSAs for marine mammals. The duplicate marine areas have been removed from the
  total number of marine areas further assessed, but that total number includes marine areas that are designated
  as IMMAs and EBSA.

    Review of OBIA Watchlist Areas--The OBIA Watchlist areas located 
within the Study Area that were re-evaluated include the British Indian 
Ocean Territory-Chagos Islands Marine Protected Area (MPA), the Pacific 
Remote Islands (PRI) Marine National Monument (MNM), Marianas Trench 
MNM, and the Papah[amacr]naumoku[amacr]kea MNM. Only one unit of the 
Marianas Trench MNM and only two units and a very small strip of the 
northern part of a third unit (Kingman Reef/Palmyra Atoll) of the PRI 
MNM were within the boundary of the Study Area (for a detailed map see 
Appendix C of the 2019 SURTASS LFA FSEIS/SOEIS). Thus, only those areas 
of the MNMs within the Study Area were further assessed.
    The British Indian Ocean Territory-Chagos Islands Marine MPA is a 
large MPA, and includes areas outside of the LFA coastal standoff 
range. All available literature and information were researched and 
reviewed; however, as was the case when this area was originally 
evaluated, very little information is available on the presence of 
marine mammals in the MPA (Dunne et al., 2014) or whether marine 
mammals conduct biologically important activities in the MPA. Due to 
the lack of supporting information and data available to demonstrate 
that the waters of this MPA are important biologically to any marine 
mammal species, the Navy and NMFS did not further consider the British 
Indian Ocean Territory-Chagos MPA as a possible OBIA but will retain 
the area on the OBIA Watchlist.
    Scientific information and data indicate that marine mammals occur 
in the waters of all the MNMs on the OBIA Watchlist. Scientific data 
and information on important biological activities conducted by marine 
mammal species were most available for the 
Papah[amacr]naumoku[amacr]kea MNM, where the majority of the very small 
population of the ESA-listed endangered Hawaiian monk seal resides, 
reproduces, and forages, and where critical habitat for

[[Page 40188]]

this species has been designated out to the 656-ft (200-m) isobath. 
Although little information and data are readily available on marine 
mammals in the waters of the Marianas Trench MNM Islands Unit or in the 
waters of Wake, Johnson, Palmyra atolls or Kingman Reef units of the 
PRI MNM, the Navy and NMFS conducted a thorough review of the available 
data for these areas. Due to the lack of supporting information and 
data available to demonstrate that the waters of the PRI MNM in the 
Study Area are important biologically to any marine mammal species, the 
Navy and NMFS did not further consider the PRI MNM as a possible OBIA 
but will retain the area on the OBIA Watchlist. Sufficient information 
and data were available to support designation of OBIAs in the waters 
of the Papah[amacr]naumoku[amacr]kea MNM and the Marianas Trench MNM 
(for a detailed analysis of these areas see Appendix C of the 2019 
SURTASS LFA FSEIS/SOEIS).
    Review of Important Marine Mammal Areas (IMMAs) as OBIAs--IMMAs are 
defined by the Marine Mammal Protected Areas Task Force (MMPATF), which 
is comprised of partners from the International Union for Conservation 
of Nature (IUCN) World Commission on Protected Areas (WCPA); IUCN 
Species Survival Commission (SSC); International Committee on Marine 
Mammal Protected Areas (ICMMPA); Tethys Research Institute; Whale and 
Dolphin Conservation (WDC); Global Ocean Biodiversity Initiative 
(GOBI), and Water Evolution organizations. These areas are defined as 
discrete portions of habitat that are important to one or more marine 
mammal species; represent priority sites for marine mammal conservation 
worldwide without management implications; and merit protection and 
monitoring. IMMA selection criteria are designed to capture aspects of 
the biology, ecology, and population structure of marine mammals, and a 
candidate IMMA need only satisfy one of the following criteria and/or 
sub-criteria to successfully qualify for IMMA status: Criterion A--
Species or Population Vulnerability; Criterion B--Distribution and 
Abundance; Criterion C--Key Life Activities; or Criterion D--Special 
Attributes. To date, IMMAs have been identified in the western and 
central Pacific Ocean, Mediterranean Sea, and the North East Indian 
Ocean and South East Asian Seas (MMPATF, 2018; 2019). IMMAs are divided 
into three categories: IMMAs, candidate IMMAs, and areas of interest. 
Only areas designated as IMMAs were considered as possible OBIAs, as 
these areas have met the IMMA selection criteria and have complete 
supporting data and information.
    All areas designated as IMMAs located in the Study Area were 
assessed as potential OBIAs. Twenty-three IMMAs are located in the 
study area for SURTASS LFA sonar (see detailed maps and summary 
assessment tables in Appendix C of the 2019 SURTASS LFA FSEIS/SOEIS). 
Of the 15 Pacific Islands IMMAs, three are located within the SURTASS 
LFA sonar Study Area in the North Pacific Ocean: The Northwest Hawaiian 
Islands, Main Hawaiian Archipelago, and Southern Shelf Waters/Slope 
Edge of Palau. However, only the Northwest Hawaiian Islands and Main 
Hawaiian Archipelago IMMAs have some part of their area located outside 
the coastal standoff zone for SURTASS LFA sonar; the geographic extent 
of the Palau IMMA is entirely located within the coastal standoff range 
for SURTASS LFA sonar and therefore does not meet the geographic 
criteria for consideration as an OBIA. Sufficient information and data 
were available to support designation of OBIAs in the waters of the 
Northwestern Hawaiian Islands and the Main Hawaiian Archipelago IMMAs 
(for a detailed analysis of these areas see Appendix C of the 2019 
SURTASS LFA FSEIS/SOEIS).
    Thirty IMMAs were designated in the North East Indian Ocean and 
South East Asian Seas (MMPATF, 2019) (see detailed maps and summary 
assessment tables in Appendix C of the 2019 SURTASS LFA FSEIS/SOEIS). 
Of these 30 IMMAs, 20 are located at least partially within the SURTASS 
LFA Study Area, with nine of these located at least partially outside 
of the coastal standoff zone. Additionally, one was only relevant to 
inshore species. Eight of the North East Indian Ocean and South East 
Asian IMMAs were carried forward for additional assessment as potential 
OBIAs.
    Review of Ecologically or Biologically Significant Marine Areas 
(EBSAs) as OBIAs--EBSAs are an effort of the Convention on Biological 
Diversity (Convention), which was initiated by the United Nations 
Environment Programme (UNEP). The Convention is an international legal 
instrument for the conservation and sustainable use of biological 
diversity. EBSAs are defined as special marine areas that serve 
important purposes that ultimately support the healthy functioning of 
oceans and thus should have increased protection and sustainable 
management. Currently there are 278 EBSAs defined worldwide, 129 of 
which are within the central or western North Pacific or eastern Indian 
Oceans. Fifty-four of these EBSAs are located in the SURTASS LFA sonar 
Study Area (see detailed maps and summary assessment tables in Appendix 
C of the 2019 SURTASS LFA FSEIS/SOEIS). Nineteen of these 54 EBSAs were 
pertinent to marine mammals under NMFS' jurisdiction, and only 14 of 
these areas are located at least partially outside the coastal standoff 
zone. One of these areas was pertinent only to coastal/inshore species 
of marine mammals and was not carried forward. In addition, the 
Ogasawara Islands EBSA was also carried forward for additional review, 
even though the EBSA is located entirely within the coastal standoff 
zone for SURTASS LFA sonar. In recognition of the importance of the 
Ogasawara area as a migrational waypoint and breeding/calving area for 
the endangered WNP DPS and stock of humpback whales, the waters beyond 
the coastal standoff zone of the Ogasawara Islands were assessed to 
determine if an areal extent could be defined in which the important 
migrational or reproductive behavior of humpback whales occurs and if 
data were sufficient to support the determination. Therefore, 14 EBSAs 
were carried forward for additional assessment as potential OBIAs.
    Review of IUCN Green List of Protected and Conserved Areas as 
OBIAs--The IUCN Green List of Protected and Conserved Areas has been 
generated as part of an IUCN program that aims to encourage, achieve, 
and promote effective, equitable, and successful protected areas with a 
principal goal of increasing the number of protected and conserved 
areas that are effectively and equitably managed and deliver 
conservation outcomes. The basis of the IUCN Green List Programme is 
the Green List Standard, which is a set of components, criteria, and 
indicators for successful protected area conservation and international 
benchmarks for quality to provide improved performance and achievement 
of conservation objectives (IUCN, 2018). Eleven of the 25 Green List 
areas are located within the SURTASS LFA sonar Study Area, but all are 
terrestrial parks or reserves, and none of the IUCN Green List 
Protected or Conserved Areas encompass any marine waters. For this 
reason, no IUCN Green List areas were further considered as potential 
OBIAs.
    Review of Areas Recommended Through Public Comment as OBIAs--In 
addition to evaluation of OBIA Watchlist areas, EBSAs, IMMAs, IUCN 
Green List of Protected and Conserved Areas (discussed above), and 
Critical Habitat areas (discussed below), NMFS

[[Page 40189]]

and the Navy evaluated areas that were suggested as OBIAs in public 
comments received on the 2018 SURTASS LFA DSEIS/SOEIS and the proposed 
rule (84 FR 7186; March 1, 2019). Ninety-three marine areas were 
recommended for consideration as OBIAs during the public comment 
periods. These areas included 30 IMMAs for the Southeast Asian Seas and 
Northeast Indian Ocean designated in February 2019. Many of the 
comments on the 2018 SURTASS LFA DSEIS/SOEIS and the proposed rule 
recommended the same marine areas, so after duplicate areas were 
removed, 69 marine areas remained were assessed. Only one of the 
recommended marine areas was not located within the SURTASS LFA sonar 
Study Area (Commander Islands). The remaining 68 marine areas, 
including the 30 newly designated IMMAs, were assessed in the context 
of the criteria for OBIAs. Of these 68 recommended marine areas, 48 
were carried forward for assessment as potential OBIAs (Table 20).
    During the assessment, marine areas were combined if they were 
designated for the same geographic area (e.g., the Gulf of Mannar where 
an EBSA and IMMA have been designated) or if different species of 
marine mammals were designated in the same marine area (e.g., humpback 
and sperm whales in the Ogasawara region). This combination of areas 
resulted in 33 marine areas being considered as potential OBIAs (see 
Table 5-2 and Appendix C in the 2019 SURTASS LFA FSEIS/SOEIS). Of these 
33, the Navy's and NMFS' assessment resulted in 14 candidate OBIAs 
representing 17 of the marine areas. Some OBIAs, such as the blue and 
humpback whale OBIAs for Western Australia, encompassed several marine 
areas, which is why the number of candidate OBIAs is smaller than the 
number of marine areas represented. The 14 candidate OBIAs 
(representing 17 areas) underwent Navy practicability review. The Navy 
determined that these OBIAs in the SURTASS LFA sonar Study Area and the 
relevant seasonal effectiveness periods would be practicable to 
implement. As a result, 14 new marine mammal OBIAs for SURTASS LFA 
sonar have been designated (Table 21) (see detailed maps and supporting 
information for each designated OBIA in Appendix C of the 2019 SURTASS 
LFA FSEIS/SOEIS). All four of the OBIAs previously designated in the 
SURTASS LFA Study Area (see Table 19) have been expanded spatially. 
Former OBIA 16, Penguin Bank, is now part of the much larger Main 
Hawaiian Islands OBIA, while OBIA 20, Northern Bay of Bengal/Swatch-of-
No-Ground (SoNG) is now encompassed in the SoNG OBIA, and the Offshore 
Sri Lanka, OBIA #26, is now part of the more encompassing Sri Lanka 
OBIA. Last, OBIA #27, Kimberly-Camden Sound was greatly expanded to 
become the Western Australia (Humpback Whale) OBIA. A list of the areas 
added to the Watchlist can be found at https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navy-operations-surveillance-towed-array-sensor-system-0.

 Table 21--Designated Marine Mammal Offshore Biologically Important Areas (OBIAs) in the SURTASS LFA Study Area
----------------------------------------------------------------------------------------------------------------
                                                                Low-frequency
       OBIA No.             OBIA name          Ocean area       marine  mammal      Effective seasonal  period
                                                                   species
----------------------------------------------------------------------------------------------------------------
1.....................  Main Hawaiian      Central North      Humpback whale...  November to April.
                         Islands \1\.       Pacific.
2.....................  Northwestern       Central North      Humpback whale...  December to April.
                         Hawaiian Islands.  Pacific.
3.....................  Mariana Islands..  Western North      Humpback whale...  February to April.
                                            Pacific.
4.....................  Ryukyu-            Western North      Humpback whale...  January to April.
                         Philippines.       Pacific.
5.....................  Ogasawara Islands  Western North      Sperm whale......  June to September.
                         (Sperm Whale).     Pacific.
6.....................  Ogasawara-Kazin    Western North      Humpback whale...  December to May.
                         Islands            Pacific.
                         (Humpback Whale).
7.....................  Honshu...........  Western North      Gray whale.......  January to May.
                                            Pacific.
8.....................  Southeast          Western North      Humpback, fin,     June to September.
                         Kamchatka.         Pacific.           Western North
                                                               Pacific gray,
                                                               and North
                                                               Pacific right
                                                               whales.
9.....................  Gulf of Thailand.  Eastern Indian     Bryde's whale....  April to November.
                                            Ocean.
10....................  Western Australia  Eastern Indian     Blue (pygmy)       May to November.
                         (Blue Whale).      Ocean.             whale.
11....................  Western Australia  Eastern Indian     Humpback whale...  May to December.
                         (Humpback Whale)   Ocean.
                         \2\.
12....................  Southern Bali....  Eastern Indian     Bryde's, sei,      October to November.
                                            Ocean.             humpback,
                                                               Omura's, and
                                                               sperm whales.
13....................  Swatch-of-No-      Northern Bay of    Bryde's whale....  Year-round.
                         Ground (SoNG)      Bengal.
                         \3\.
14....................  Sri Lanka \4\....  Eastern Indian     Blue (pygmy) and   October to April.
                                            Ocean.             sperm whales.
----------------------------------------------------------------------------------------------------------------
\1\ Expansion of existing OBIA #16, Penguin Bank.
\2\ Expansion of existing OBIA #27, Kimberly-Camden Sound.
\3\ Expansion of existing OBIA #20, Northern Bay of Bengal/SoNG.
\4\ Expansion of existing OBIA #26, Offshore Sri Lanka

Other Geographic Mitigation Considerations

    Above, we describe a comprehensive process and set of criteria for 
identifying OBIAs, which, when used in conjunction with the limits on 
SURTASS LFA sonar transmission levels in and around them described 
above, we expect to decrease the likelihood and/or scale of impacts on 
marine mammal species or stocks. However, the inclusion of this focused 
and systematic process and criteria for designating OBIAs does not mean 
that other mitigation, including specific time/area restrictions, could 
not be considered in the context of the LPAI standard. Below we address 
some other factors that NMFS and the Navy considered in the development 
of the final rule.

[[Page 40190]]

ESA-Designated Critical Habitat
    Under section 7 of the ESA, all Federal agencies must ensure that 
any actions they authorize, fund, or carry out are not likely to 
jeopardize the continued existence of a listed species or destroy or 
adversely modify its designated critical habitat. ESA-designated 
critical habitat is not designated in foreign countries or any other 
areas outside of U.S. jurisdiction. Critical habitat within the U.S. 
EEZ implicated by SURTASS LFA sonar activities has been designated for 
two of the relevant ESA-listed marine mammal species, Hawaiian monk 
seals and the Main Hawaiian Island (MHI) Insular DPS of false killer 
whales. Effects to ESA-designated critical habitat are explicitly 
addressed through the section 7 consultation process under the ESA. 
Notably, the ESA biological opinion for the Navy's SURTASS LFA sonar 
activities and this MMPA rule concludes that they are not likely to 
adversely affect the relevant designated critical habitat for those 
species.
    Some of the characteristics of ESA-designated critical habitat are 
also germane to the identification of OBIAs or other mitigation under 
this rulemaking. However, critical habitat also considers physical as 
well as biological features and may also consider areas that are 
currently unoccupied by the species. Therefore, not all critical 
habitat necessarily qualifies as an OBIA or is appropriate as a basis 
for other time/area restrictions for SURTASS LFA sonar when considering 
mitigation under the MMPA. As it pertains to the potential inclusion of 
these areas as OBIAs, we note that neither of these two ESA-listed 
species is a LF hearing specialist or sensitive to SURTASS LFA sonar in 
a manner that would otherwise justify additional species-specific 
mitigation on their behalf, given the existing protections of the 
Navy's three-part detection and shutdown protocols and coastal standoff 
zone.
    Nearly all of the ESA-designated critical habitat for the Hawaiian 
monk seal lies within the coastal standoff distance for SURTASS LFA 
sonar. A small area of the monk seal's critical habitat at Penguin Bank 
extends beyond the 22-km (12-nmi) coastal standoff distance, which is 
part of the Main Hawaiian Islands OBIA (designated in this final rule). 
Per the CZMA consultation with the State of Hawaii for SURTASS LFA 
sonar, the Navy agreed not to operate SURTASS LFA sonar in the waters 
of Penguin Bank to the 600-ft (183-m) isobath. In addition, the Navy 
also agreed not to ensonify Hawaii state waters at levels above 145 dB 
re: 1 [mu]Pa rms. Main Hawaiian Islands and Northwestern Hawaiian 
Islands OBIAs (designated in this final rule), effective from November 
to April and December to April, respectively, encompass the critical 
habitat for Hawaiian monk seal. During this time, the received levels 
in waters within 1 km of these OBIAs will not exceed 180 dB re: 1 
[mu]Pa (rms).
    The ESA-designated critical habitat for the MHI insular false 
killer whale (MHI IFKW) DPS includes waters from the 148- to 10,499-ft 
(45-to 3,200-m) depth contours around the MHI from Niihau east to 
Hawaii. MHI IFKWs are island-associated whales that rely entirely on 
the productive submerged habitat of the main Hawaiian Islands to 
support all of their life-history stages, and their range is restricted 
to the shelf and slope habitat around the MHI, unlike pelagic false 
killer whales found more in open oceans. Because of the habitat 
characteristics that are important components to the ecology of these 
whales, NMFS identified a single feature, island-associated marine 
habitat, with four characteristics that support this feature as 
essential to their conservation. The four characteristics include: (1) 
Adequate space for movement and use within shelf and slope habitat; (2) 
prey species of sufficient quantity, quality, and availability to 
support individual growth, reproduction, and development, as well as 
overall population growth; (3) waters free of pollutants of a type and 
amount harmful to MHI IFKWs; and (4) sound levels that will not 
significantly impair the whales' use or occupancy.
    Some Navy and other Federal agency areas, such as the Pacific 
Missile Range Facility offshore ranges, are excluded from the critical 
habitat designation (NOAA, 2018). In most areas of the waters 
surrounding the MHI, the coastal standoff range for SURTASS LFA (12 nmi 
(22 km)) is located closer to shore than the seaward boundary of the 
critical habitat for the MHI Insular DPS of the false killer whale 
(i.e., some of the critical habitat is beyond the coastal standoff 
range). The Main Hawaiian Islands OBIA (designated in this final rule) 
encompasses some of the critical habitat, but a portion of the critical 
habitat lies beyond the OBIA. However, as discussed above, part of the 
CZMA stipulations for SURTASS LFA sonar use in Hawaiian waters required 
the Navy to agree not to use SURTASS LFA sonar in the waters over 
Penguin Bank to a water depth of 600 ft (183 m) and to limit 
ensonification within Hawaii state waters (out to 3 nmi) to 145 dB re: 
1 [mu]Pa rms.
    Regarding prey availability (large pelagic fish and squid) of 
sufficient quantity, quality, and availability to support individual 
growth, reproduction, and development, as well as overall population 
growth of false killer whales, no mortality of marine invertebrates is 
reasonably expected to occur from exposure to LFA sonar training and 
testing activities nor are population level effects likely. Thus, 
marine invertebrates such as squid would not reasonably be adversely 
affected by SURTASS LFA sonar training and testing activities such that 
their availability (or other prey availability) would be diminished 
(also refer to Chapter 3, section 3.4.2.1 of the 2019 SURTASS LFA 
FSEIS/SOEIS for a discussion of why marine invertebrates are not 
reasonably likely to be adversely impacted by SURTASS LFA sonar 
training and testing activities). Marine fishes, however, may be 
affected by exposure to LFA sonar transmissions, but only if they are 
located within close proximity (<0.54 nmi (<1 km)) to the transmitting 
sonar source. The Navy's analysis indicates a minimal to negligible 
potential for an individual fish to experience non-auditory or auditory 
effects or a stress response from exposure to SURTASS LFA sonar 
transmissions. A low potential exists for minor, temporary behavioral 
responses or masking effects to an individual fish when LFA sonar is 
transmitting, but no potential is estimated for fitness level 
consequences to fish stocks. Since it is highly unlikely that a 
significant percentage of any prey stock would be in sufficient 
proximity during LFA sonar transmissions to experience such effects, 
there is minimal potential for LFA sonar to affect prey fish stocks. 
Thus, no adverse effects are reasonably expected on the quantity, 
quality, and availability of prey fishes as the result of exposure to 
SURTASS LFA sonar training and testing activities. Accordingly, SURTASS 
LFA sonar training and testing activities would not significantly 
impact the biological characteristics of prey availability of the MHI 
IFKW DPS's designated critical habitat.
    Regarding the underwater sound produced by SURTASS LFA sonar, it 
would not be expected to ``significantly impair false killer whale's 
use or occupancy'' due both to the small scale of the activity (small 
number of vessels operating across two ocean basins, meaning that any 
individual marine mammal would be expected to be exposed for only a 
short amount of time) and the frequency of the SURTASS signal, which is 
not in the range of

[[Page 40191]]

higher sensitivity for this species and would not be expected to 
interfere with their communication. Further, required shutdowns are 
expected to minimize false killer whale exposure to high sound levels 
and the Navy's implementation of a coastal standoff zone means that 
SURTASS LFA training and testing is not occurring across much of the 
critical habitat. No aspect of SURTASS LFA sonar training and testing 
activities would reasonably be expected to impact the spatial use of 
false killer whales. As a result, the use of SURTASS LFA sonar for 
training and testing activities in Hawaiian waters would not reasonably 
be expected to have any impact on the physical characteristics of the 
false killer whale critical habitat since neither the spatial 
availability nor sound levels in the continental shelf and slope 
habitat would be significantly impacted. As noted, NMFS is not 
recommending additional geographic mitigation in this area.
    Both the Navy and NMFS Protected Resources Permits and Conservation 
Division consulted with NMFS Protected Resources Interagency 
Cooperation Division on effects on critical habitat pursuant to section 
7 of the ESA.
Coastal Standoff Zone
    The Navy will restrict training and testing activities utilizing 
SURTASS LFA sonar within 22 km (14 mi; 12 nmi) of any coastline, 
including islands, such that the SURTASS LFA sonar-generated sound 
field will not exceed a received level of 180 dB re: 1 [mu]Pa rms at 
that seaward distance. This measure is intended to minimize both the 
severity and scale of effects to marine mammals and, by extension, 
marine mammal species and stocks, by avoiding areas where many 
biologically important behaviors and higher densities of many species 
that may be found in coastal areas occur. In the past, some commenters 
have recommended the Navy implement a larger coastal standoff zone than 
what we proposed. We reiterate that as noted in 2012 final rule (77 FR 
50290; August 20, 2012), approximately 80 percent of known and 
potential marine protected areas are within the 22 km (12 nmi) coastal 
standoff zone, an indication of this measure's effectiveness, and it is 
practicable. Additionally, this restriction limits exposures of marine 
mammals to high-level sounds in the vicinity of geographical features 
that have been associated with some stranding events (i.e., enclosed 
bays, narrow channels, etc.) attributed to activities other than 
SURTASS LFA sonar.
    The Navy's 2007 SURTASS LFA SEIS/SOEIS evaluated increasing the 
coastal standoff distance up to 46 km (25 nmi) and, based on a six-step 
analysis process, determined that increasing the coastal standoff range 
would decrease exposure to higher received levels for concentrations of 
marine animals closest to shore, but would do so at the expense of 
increasing exposure levels for shelf break and pelagic species. There 
have been no changes to the best available information or other 
indications that the coastal standoff distance should be increased, so 
there is no change in this mitigation measure from previous 
rulemakings. In addition, any areas beyond the 12 nmi coastal standoff 
can still be considered for mitigation, such as through the OBIA 
process.

White Paper on ``Identifying Areas of Biological Importance to 
Cetaceans in Data-Poor Regions''

    As described earlier, for the 2012 rulemaking, NMFS convened a 
panel of subject matter experts (SMEs) to help identify marine mammal 
OBIAs relevant to the Navy's use of SURTASS LFA sonar. Separately, we 
consulted a NMFS scientist, who was also on that same SME panel, to 
help address a recommendation in a public comment that NMFS consider a 
global habitat model (Kaschner et al., 2006) in the development of 
OBIAs. In addition to providing the requested input (which essentially 
concluded that using the Kaschner model was not advisable, for several 
reasons), the NMFS scientist, in conjunction with other NMFS 
scientists, went further and provided some guidance for alternate 
methods for considering ``data poor areas'' and drafted a paper 
entitled ``Identifying Areas of Biological Importance to Cetaceans in 
Data-Poor Regions'' (referred to in this notice as the ``White 
Paper''). NMFS' consideration of the White Paper was discussed in the 
9th Circuit's ruling on our 2012 final rule, and as a consequence we 
provide here some additional details and background regarding our 
consideration of the White Paper recommendations for this rulemaking.
Kaschner et al. (2006) Recommendation
    As requested, the White Paper authors reviewed the Kaschner et al. 
(2006) paper in the context of potential mitigation for SURTASS LFA 
sonar. The Kaschner et al. (2006) paper used models based on a 
synthesis of ``existing and often general qualitative observations 
about the spatial and temporal relationships between basic 
environmental conditions and a given species' presence'' to ``develop a 
generic quantitative approach to predict the average annual geographic 
ranges'' of marine mammal species on a global scale. Several 
environmental correlates including depth, sea surface temperature, 
distance to land, and mean annual distance to ice edge were used in the 
Kaschner effort. After evaluating four case studies from the Kaschner 
et al. (2006) study for predicting gray whale, northern right whale 
dolphin, North Atlantic right whale, and narwhal distribution, the 
authors of the White Paper concluded that ``(t)he predictions from the 
four case studies . . . included errors of omission (exclusion of areas 
of known habitat) and commission (inclusion of areas that are not known 
to be habitat) that could have important implications if the model 
predictions alone were used for decision making in a conservation or 
management context.''
    Specifically, the White Paper illustrated that the Kaschner et al. 
effort omitted a considerable portion of known gray whale habitat; 
overestimated the range of suitable habitat for northern right whale 
dolphins off the U.S. West Coast (noting that species-specific models 
based on dedicated shipboard surveys more correctly identified suitable 
habitat); predicted habitat for North Atlantic right whales in large 
areas where they have never been recorded; and predicted suitable 
habitat for narwhal that did not correspond with their known 
distribution. Noting that these significant inaccuracies in the model 
could result in either under-protection or over-restrictiveness, the 
authors of the White Paper did not recommend basing the identification 
of biologically important areas on this modeling. NMFS concurred with 
this recommendation and elected not to use the Kaschner paper, or other 
similar predictive envelope models as a basis for identifying 
additional protective areas in the 2012 SURTASS LFA sonar incidental 
take rule.
Clarification of Concepts Raised in White Paper
    In NRDC v. Pritzker, referring to the White Paper and its specific 
recommendations that NMFS did not adopt for identification of OBIAs, 
the 9th Circuit stated that NMFS, in its 2012 rule, ``did not give 
adequate protection to areas of the world's oceans flagged by its own 
experts as biologically important, based on the present lack of data 
sufficient to meet the Fisheries Service's (OBIA) designation criteria, 
even though NMFS' own experts

[[Page 40192]]

acknowledged that (f)or much of the world's oceans, data on cetacean 
distribution or density do not exist.'' NRDC v. Pritzker, 828 F.3d at 
1142. Although the White Paper authors utilized the term ``biological 
importance'' in the title of the paper, they clearly stated that ``it 
must be decided whether the list of OBIAs should be comprehensive 
(based on a `precautionary approach') or pure (based on the `minimalist 
approach'),'' and explicitly declined to provide an answer. 
Specifically, they indicated ``it must be decided whether to be 
precautionary and possibly nominate areas that are of marginal 
importance in an attempt to minimize the chances of overlooking 
biologically important areas'' or ``minimize the chances of nominating 
sites that are of marginal biological importance and, therefore, risk 
overlooking biologically important areas.'' Then, the authors suggested 
three general recommendations for decision making based upon a 
precautionary approach if that is the method selected by the decision 
maker, as discussed further below.
    However, the recommendations of the White Paper present a 
dichotomous ``precautionary versus non-precautionary'' choice, an 
interpretation that fails to consider the context of the requirements 
of the MMPA, the nature of the anticipated effects of the action at 
issue, and the other mitigation measures. More appropriately, NMFS has 
fully and independently considered each of the White Paper's three 
recommendations in the context of the MMPA's LPAI standard, as 
described below. In that analysis, we first note the small scale of the 
anticipated effects of the Navy's request for authorization (496-592 
hours/year of SURTASS LFA sonar spread across two ocean basins) and the 
low magnitude and severity of impacts expected to any individual marine 
mammals (relatively short-term exposures given the spatial scale of the 
vessels' movement), even in the absence of mitigation, given the nature 
of the activities. Then we note the robust shutdown measures that 
utilize the highly effective visual, passive acoustic, and active 
acoustic detection methods that are in place for all areas and times to 
avoid marine mammal injury as well as minimize TTS and more severe 
behavioral responses, belying claims that we treat data-poor areas as 
though they are equivalent to zero-density areas or areas of no 
biological importance. Next, we discuss the coastal standoff zone, 
which minimizes take of many species with coastal habitat preferences. 
We then examine the activity restrictions in OBIAs, which further limit 
potentially more significant impacts in areas that are known to be 
biologically important to the species that are more susceptible to the 
SURTASS LFA sonar signal. Finally, we discuss the limited and uncertain 
additional protective value that the White Paper recommendations would 
be expected to provide for marine mammal individuals, much less species 
or stocks. After considering all of this information, in addition to 
the information provided by the Navy indicating that further 
restricting SURTASS LFA sonar training and testing in the areas 
recommended in the White Paper would be impracticable, NMFS determined 
that the use of the White Paper recommendations was not appropriate.

White Paper Specific Recommendations

    While the White Paper authors essentially disqualified the specific 
extrapolative predictive results of the Kaschner model based on 
validating them against known data, they nevertheless recommended 
broader protections based on fewer environmental variables, to be used 
if NMFS determined that a ``precautionary approach'' was appropriate. 
Although the current White Paper recommendations are grounded in some 
sound broad ecological principles, basing mitigation on the 
``precautionary approach'' considered by the White Paper authors 
suffers from some of the same types of weaknesses as using the Kaschner 
model or other ``environmental envelope'' approaches. In the 2012 
SURTASS LFA sonar rule, NMFS evaluated the White Paper solely through 
the lens of the OBIA process, and determined that the recommendations 
presented were not appropriate for identification of OBIAs, which may 
have limited fuller consideration of the recommendation. For this 
rulemaking, NMFS independently examined the White Paper's specific 
recommendations in the context of the LPAI standard to determine 
whether following those recommendations is warranted to minimize the 
impacts from SURTASS LFA sonar training and testing activities on the 
affected marine mammal species or stocks. This consideration was done 
outside of the OBIA designation process, and is consistent with the 
consideration of the LPAI criteria described above when determining 
appropriateness of mitigation measures. The White Paper recommended the 
following general guidelines based on ecological principles to identify 
areas of biological importance for cetaceans:
    (1) Designation of all continental shelf waters and waters 100 km 
seaward of the continental slope as biologically important habitat for 
marine mammals;
    (2) Establishment of OBIAs within 100 km of all islands and 
seamounts that rise within 500 m of the surface; and
    (3) Nomination of high productivity regions that are not included 
in the continental shelf, continental slope, seamount, and island 
ecosystems above as biologically important areas.
    These recommendations were evaluated (see below) in the context of 
the proposed SURTASS LFA sonar training and testing activities and the 
mitigation measures proposed to be implemented to minimize impacts on 
the affected marine mammal species or stocks from these activities.
    To reiterate, NMFS has required several mitigation measures for 
SURTASS LFA training and testing sonar activities that: (1) Minimize or 
alleviate the likelihood of injury (PTS), TTS, and more severe 
behavioral responses (the 2,000-yd LFA mitigation/buffer zone); (2) 
additionally minimize or avoid behavioral impacts in known important 
areas (which includes important habitat) that would have a higher 
potential to have negative energetic effects or deleterious effects on 
reproduction that could reduce the likelihood of survival or 
reproductive success (OBIAs); and (3) generally lessen the total number 
of takes of many species with coastal or shelf habitat preferences 
(coastal standoff). The nature and context of how LFA sonar is used in 
training and testing activities (small number of vessels operating in 
open ocean areas and typically using active sonar only sporadically) is 
such that impacts to any individual are expected to be limited 
primarily because of the short duration of exposure to any individual 
mammal. In addition, as explained above, an animal would need to be 
fairly close to the source for the entire length of a transmission (60 
sec) to experience injury, and exposures occur in open water areas 
where animals can more readily avoid the source and find alternate 
habitat relatively easily. In addition, highly effective mitigation 
measures would be implemented that further ensure impacts are limited 
to lower-level responses with limited potential to significantly alter 
natural behavior patterns in ways that would affect the fitness of 
individuals and by extension the affected species or stocks.
    SURTASS LFA sonar operates from 100 to 500 Hz. These frequencies 
are far below the best hearing sensitivity for MF and HF species. HF 
species have

[[Page 40193]]

their best hearing between around 60 and 125 kHz, which means that a 
sound at 500 Hz (and below) has to be at least 50 dB louder for HF 
species to hear it as well as a sound in their best hearing range. MF 
cetaceans have their best hearing between around 40 and 80 kHz, which 
means that at 500 Hz and below, the sound has to be 40 dB louder, or 
more, for this group to hear the sound as well as a sound in their best 
hearing range. In other words, these species have to be much closer to 
a sound at the frequency of SURTASS LFA sonar to hear it, which means 
that generally they have to be much closer to the SURTASS sonar source 
for it to cause PTS, TTS, or a behavioral response. Additionally, 
during the 1997 to 1998 SURTASS LFA Sonar LFS SRP, numerous odontocete 
species (i.e., MF and HF hearing specialists) and pinniped species were 
sighted in the vicinity of the sound exposure tests and showed no 
immediately obvious responses or changes in sighting rates as a 
function of source conditions, which likely produced received levels 
similar to those that produced minor short-term behavioral responses in 
the baleen whales (i.e., LF hearing specialists).
    As described in the 2012 rule, NMFS believes that MF and HF 
odontocete hearing specialists have such reduced sensitivity to the LFA 
sonar source that limiting ensonification in OBIAs for those animals 
would not afford meaningful protection beyond that which is already 
incurred by implementing a shutdown when any marine mammal enters the 
2,000-yd LFA sonar mitigation zone. For the same reason, our discussion 
of the White Paper recommendations is limited to low frequency 
sensitive species. We note the White Paper's recommendations for 
mitigation in data-poor areas similarly were solely for cetaceans.
    As noted previously, in evaluating mitigation for species or stocks 
and their habitat, we consider the expected benefits of the mitigation 
measures for the species or stocks and their habitats against the 
practicability of implementation. This consideration includes assessing 
the manner in which, and the degree to which, the implementation of the 
measure(s) is expected to reduce impacts to marine mammal species or 
stocks (including through consideration of expected reduced impacts on 
individuals), their habitat, and their availability for subsistence 
uses (where relevant). This analysis will consider such things as the 
nature of the proposed activity's adverse impact (likelihood, scope, 
range); the likelihood that the measure will be effective if 
implemented; the likelihood of successful implementation. 
Practicability of implementing the measure is also assessed and may 
involve consideration of such things as cost, impact on operations, 
and, in the case of a military readiness activity, personnel safety, 
practicality of implementation, and impact on the effectiveness of the 
military readiness activity (16 U.S.C. 1371(a)(5)(A)(ii)).
    Taking into account the above considerations, NMFS' evaluation of 
the White Paper's recommendations is described below:
    Continental shelf waters and waters 100 km seaward of continental 
slope
    Consideration of potential for reduction of adverse impacts to 
marine mammal species and stocks and their habitat--The Navy already 
implements a coastal standoff zone of 22 km (14 mi; 12 nmi), which 
includes large parts of the continental shelf around the world, 
includes parts of the slope in some areas, and reduces potential takes 
of many marine mammal species and stocks with coastal habitat 
preferences. In addition, under this rulemaking, the Navy is not able 
to deploy and utilize SURTASS LFA sonar for training and testing within 
any foreign nations territorial seas, which encompasses an area up to 
12 nmi (depending on the distance each nation claims). The White Paper 
provided little basis for the 100 km buffer seaward of the continental 
slope and we have found no specific literature to support such a broad 
buffer in all areas. Therefore, in the context of this evaluation, NMFS 
first considered if there was evidence of the importance of the 
continental slope itself, without any consideration for a buffer.
    In support of understanding the additional value of expanding this 
standoff to 100 km beyond the continental slope margin, NMFS assessed 
known marine mammal density information for low frequency hearing 
specialists from the U.S. East (Roberts et al., 2016) and West coasts 
and compared these densities to bathymetry, specifically looking at 
areas of high density compared to the continental shelf and slopes on 
both coasts (NOAA, 2009). This assessment and comparison focused on the 
U.S. East and West coasts as an example because relatively more data is 
available for these waters. The comparison showed that mapped areas of 
highest densities are not always related to the slope or shelf. For 
example, while fin whales in the eastern U.S. waters show relatively 
higher densities on the continental shelf and slope, relatively higher 
densities of fin whales in western U.S. waters are much farther out to 
sea from the continental shelf or slope (well beyond 100 km of the 
slope), and the same was found for sperm whales. Some mysticetes do 
show higher densities on the continental shelf, and some have higher 
densities along the continental slope, which may also vary among 
seasons (e.g., fin whales on the east coast). Generally, density 
information from the Atlantic showed some enhanced densities along the 
slope, but only for certain species in certain seasons, and did not 
indicate universally high densities along the slope. There are many 
factors that influence the spatial and temporal distribution and 
abundance of cetaceans, including environmental variables such as 
physiochemical, climatological, and geomorphological variables 
operating on times scales ranging from less than a day to millennia; 
biotic variables, such as prey distribution, competition among other 
species, reproduction, and predation; and anthropogenic factors, such 
as historical hunting, pollution, ship activity, etc. (Davis et al., 
1998). Humpback whales (especially around Cape Hatteras) seem to show 
some higher densities around the slope, but also seaward of the slope, 
especially in winter. However, the slope is closer to the shore around 
Cape Hatteras than most places along the eastern seaboard, and while 
humpbacks may show higher densities along the slope in this area, the 
same cannot be said of humpbacks further south (i.e., in Florida) where 
the slope is much further offshore. Right whales show higher densities 
closer to shore along the Atlantic coast, while sperm whales are 
farther out past the slope on the Atlantic coast, as they are deep 
divers. Density data from the Pacific coast show higher densities of 
blue whales on the shelf and slope, while fin whales and sperm whales 
are observed in waters beyond the continental slope. Gray whales show 
higher densities closer to shore along the Pacific coast, while 
humpbacks seem to be along the slope and beyond in some places. Using 
the continental United States densities of these lower frequency 
sensitive species as examples showed that densities are sometimes 
higher within 100 km of the slope, but are often higher elsewhere (off 
the slope) and many of these high density areas are highly seasonal.
    As stated above, NMFS looked at these areas because relatively more 
data are available and, since comparisons in these areas do not 
consistently show strong correlation of high densities with the 
continental slope, it is reasonable to infer the same inconsistent 
relationship

[[Page 40194]]

for other slope/shelf areas where there are even fewer data. As 
discussed below, there is no scientific basis for NMFS to conclude that 
geographical restrictions for these data-poor areas would reduce 
adverse impacts to marine mammal species or stocks or their habitat. 
Therefore, restricting SURTASS LFA sonar training and testing 
activities within 100 km of the entire continental shelf and slope is 
of questionable value as a mitigation measure to avoid areas of higher 
densities of marine mammal species or stocks, and further, would 
restrict these activities in large areas of the open ocean that we know 
do not harbor high densities of marine mammals (especially when the 
100-km buffer is considered).
    We said in the OBIA context that although we are identifying 
``known'' biologically important areas, other biologically important 
areas have yet to be identified, due to limited data. However, it is 
important to realize that much more research is conducted close to 
shore, in the United States and internationally, and typically areas 
within 100 km of the slope are less likely to be data-poor compared to 
other areas. In areas where there is extensive data on marine mammal 
density and use (e.g., in the continental US EEZ), it may be 
inappropriate to use broader principles that could be helpful in 
identifying protected areas in data-poor areas. NOAA, Navy, other 
agencies, and many independent researchers have been conducting marine 
mammal research throughout the U.S. EEZ (200 mi from shore) for 
decades. The prevalence of research makes it less likely that important 
areas closer to shore have been overlooked.
    NMFS acknowledges that large ocean areas such as the continental 
shelf and slope and seamounts may include habitat features that could 
provide important habitat for marine mammals at certain times--as the 
White Paper states, the higher primary productivity in these areas 
could generally be associated with higher densities of marine mammals. 
However, exposures to any individual animal are expected to be short 
term and intermittent, since a small number of ships would conduct 
SURTASS LFA sonar training and testing activities for up to 496 hours 
(years 1-4) and 592 hours (years 5-7) total for all ships combined 
annually. In addition, shutdown measures would avoid injury (PTS), most 
TTS, and severe behavioral responses, and coastal standoff zones and 
OBIAs would avoid disturbances more likely to lead to fitness impacts 
by further restricting activities in these areas of known biological 
importance for marine mammals. Therefore, the other mitigation measures 
(which are currently in effect) would already limit most take of marine 
mammals to less severe Level B harassment (e.g., short periods of 
changes to swim speed or calling patterns; alterations of dive 
profiles, etc.). As a result, there is little to no indication that 
there is a risk to marine mammal species or stocks that would be 
avoided or lessened if waters 100 km seaward of the continental slope 
were subject to restrictions.
    Of note, in many areas the waters of the continental shelf/slope 
will be afforded significant protection due to the coastal standoff 
mitigation measure. In addition, review of designated OBIAs reveals 
that the majority include continental shelf/slope areas and similar 
coastal waters. The Navy will also transmit no more than 25 percent of 
the authorized amount (transmission hours) of SURTASS LFA sonar for 
training and testing activities within 10 nmi (18.5 km) of any single 
OBIA during any year (no more than 124 hours in years 1-4 and 148 hours 
in years 5-7). Therefore, to the extent that some portion of the shelf/
slope waters are important habitats, many are afforded protection due 
to the geographical restrictions already in place (coastal standoff and 
OBIAs), and NMFS has determined that the best available information 
justifies these measures under our evaluation framework set forth 
above.
    Given the proposed mitigation measures, many of which are already 
in place under the NDE and have been in effect for many years under 
prior rules, takes of marine mammals would be limited to Level B 
harassment in the less severe range of behavioral reactions and some 
TTS, as described above. Consequently, the only additional anticipated 
value to restricting activities in continental shelf waters and waters 
100 km seaward of continental slope would be some, though not a 
significant, reduction in the number of these less severe behavioral 
reactions in those areas. As discussed above, in general, not all 
behavioral responses rise to the level of a take and not all harassment 
takes result in fitness consequences to individuals that have the 
potential to translate to population consequences to the species or 
stock. For example, the energetic costs of short-term intermittent 
exposures to SURTASS LFA sonar (such as are expected here) would be 
unlikely to affect the reproductive success or survivorship of 
individuals. This means there is little to no likelihood that the 
impacts of the anticipated takes would accrue in a manner that would 
impact a species or stock even in the absence of any additional 
mitigation. Therefore, considered with the uncertain potential of this 
proposed recommendation to provide meaningful incremental reduction of 
risk or severity of impacts to individual marine mammals, NMFS 
concludes that this recommendation would not reasonably be expected to 
provide a reduction in the probability or degree of effects on any 
marine mammal species or stocks.
    In addition to the mitigation measures in place for SURTASS LFA 
sonar that would already provide protection for continental shelf/slope 
waters, it is important to note that there are currently a total of 
four SURTASS LFA sonar ships that would be training and testing with up 
to a maximum of 496 transmission hours total, pooled across all 
vessels, per year in years one through four. While the Navy plans to 
add additional vessels beginning in year 5, the total transmission 
hours would be capped at 592 hours total, regardless of the number of 
vessels. It is not known, nor does the Navy indicate in its plans, 
whether activities of these existing or proposed new vessels would be 
focused in any specific area. It is likely, based on past monitoring 
reports, that the activities of the multiple vessels are spatially 
separated and not concentrated in a single area, and that they would 
not necessarily overlap marine mammal high-density areas for an 
extended period of time. However, as noted, the Navy will transmit no 
more than 25 percent of the authorized amount (transmission hours) of 
SURTASS LFA sonar for training and testing activities within 10 nmi 
(18.5 km) of any single OBIA during any year, which means no more than 
124 hours in years 1-4 and 148 hours in years 5-7.
    Consideration of practicability for restrictions in continental 
shelf waters and waters 100 km seaward of continental slope--NMFS and 
the Navy evaluated the practicability of implementation of the White 
Paper's recommended continental shelf, slope, and 100-km seaward 
restriction. The Navy has indicated, and NMFS concurs, that additional 
continental shelf, slope, and 100 km seaward restrictions beyond the 
territorial waters of foreign nations and the existing coastal standoff 
and OBIAs would unacceptably impact the Navy's national security 
mission, as large areas of the ocean would be restricted where LFA 
sonar transmissions are required for training and testing proficiency 
in order for the ships' crews to understand how the system operates in 
these varied bathymetry conditions under future operational scenarios.

[[Page 40195]]

    The submarine forces of several key adversaries are rapidly growing 
in size, capability, and geographic reach. Due to advancements in 
quieting technologies in diesel-electric and nuclear submarines, 
undersea threats are becoming increasingly difficult to locate using 
traditional passive acoustic technologies. Submarines from many nations 
are now much more capable and able to stay submerged for a longer 
period of time than earlier vessels. For both conventional diesel-
electric and nuclear submarines, quieting technology has increased 
stealth and thus operational effectiveness. These technologies include 
air-independent propulsion (AIP), hull coatings that minimize echoes, 
sound isolation mounts for machinery, and improved propeller design. 
What once were unique U.S. design capabilities are now being employed 
in new submarine projects and as upgrades to older submarines 
throughout potential adversaries' navies. As this technology has 
improved, the predominant sources of ship noise (for example propeller 
noise or other machinery noise) have been reduced. Passive sonar 
involves listening for sounds emitted by a potentially hostile 
submarine in order to detect, localize, and track it. As submarines 
become quieter through improved sound dampening technology and 
innovative propeller design, the usefulness of passive sonar systems 
has greatly diminished. These submarines have the ability to carry many 
different weapons systems, including torpedoes, long-range anti-ship 
cruise missiles, anti-helicopter missiles, anti-ship mines, and 
ballistic nuclear missiles. These capabilities make submarines, both 
nuclear and diesel-electric powered, stealthy and flexible strategic 
threats.
    The destruction of U.S. Carrier Strike Groups (CSGs) and 
Expeditionary Strike Groups (ESGs) is a focal point in the naval 
warfare doctrine of many adversaries' navies. The main threat that a 
carrier strike group must defend against is the undersea threat from 
enemy submarines. A single diesel-electric submarine that is capable of 
penetrating U.S. or multinational task force defenses could cause 
catastrophic damage to those forces, and jeopardize the lives of 
thousands of sailors and Marines onboard Navy ships. Even the threat of 
the presence of a quiet diesel submarine could effectively deny or 
delay U.S. or coalition naval forces access to vital operational areas. 
Long-range detection of threat submarines in near-shore and open ocean 
environments is critical for this effort.
    Adequate and effective training and testing with SURTASS LFA sonar 
is necessary to ensure crews can operationally detect these quieter and 
harder to-find foreign submarines at greater distances. The Navy has 
indicated that if large areas of the continental shelf or slope were 
restricted beyond what is in the 12nmi/22km coastal standoff, the Navy 
would not have the benefit of being able to train and test in these 
challenging environments. Coastal, shallow environments are more 
acoustically complex and the SURTASS LFA system was designed to 
penetrate these environments to find quiet assets that may use these 
distinctive geographic features to their advantage. Year-round access 
to all of these areas of challenging topography and bathymetry is 
necessary so that crews learn how the SURTASS LFA system will operate 
amidst changing oceanographic conditions, including seasonal variations 
that occur in sound propagation.
    Because these assets are forward deployed and can rapidly switch 
between training and testing activities and operational missions, there 
is limited flexibility for these ships to maneuver any substantial 
distance from primary mission areas of responsibility. Therefore, 
avoiding continental shelf and slope waters plus a 100 km buffer for 
training and testing activities would constitute a significant 
deviation in their staging requirements for other missions. Thus, 
implementing this mitigation measure would be highly impracticable and 
would significantly adversely affect the availability of these assets 
to conduct their national security mission. Additionally, due to the 
slow speed at which these vessels transit (3 to 4 knots when towing 
SURTASS, 10-12 knots without) it does not allow for large scale 
movements on the orders of 100s of km proposed by the mitigation scheme 
of the White Paper to avoid a 100 km buffer around continental shelf 
and slope habitat.
    Conclusion regarding restrictions in continental shelf waters and 
waters 100 km seaward of continental slope--In summary, restricting 
SURTASS LFA sonar use in waters 100 km seaward from the continental 
slope could potentially reduce individual exposures or behavioral 
responses for certain species and potentially provide some additional 
protection to individual animals in preferred habitat in some cases. 
However, density data indicate that certain mysticetes and sperm whales 
have higher densities in areas other than the continental slope and 
potential impacts from moving and focusing activities farther offshore 
would shift from more coastal species or stocks to more pelagic species 
or stocks, making any reduction in impacts uncertain. Further, limiting 
activities in these large areas of uncertain value to marine mammals 
when activities are comparatively low (small number of ships operating 
up to a maximum of 496 transmission hours total across all vessels in 
years 1-4 and 592 total transmission hours in years 5 and beyond pooled 
across all vessels, spread across several mission areas and over the 
course of an entire year), given the existing risks to the affected 
species and stocks are already so low, would provide little, if any, 
value for lowering the probability or severity of impacts to individual 
marine mammal fitness, much less species or stocks, or their habitat. 
Given the limited potential for additional reduction of impacts to 
marine mammal species beyond what the existing mitigation measures 
described in this rule provide, and the high degree of impracticability 
(significant impacts on training and testing effectiveness and the 
availability of these assets to support other national security 
missions), NMFS has determined that adopting this recommendation is not 
warranted under the LPAI standard.
Restrictions Within 100 km of All Islands and Seamounts That Rise to 
Within 500 m of the Surface
    Consideration of potential reduction of adverse impacts to marine 
mammal species and stocks and their habitat--Currently, waters 
surrounding all islands are included in the coastal standoff zone. As 
discussed previously, this means that SURTASS LFA sonar received levels 
would not exceed 180 dB re: 1 [micro]Pa within 22 km (12 nmi) from the 
coastline. Also, SURTASS LFA sonar will not be operated within foreign 
territorial waters. Lastly, the Navy has agreed not to utilize SURTASS 
LFA sonar within the waters of Penguin Bank (to a depth of 600 ft (183 
m)), and to limit ensonification of Hawaii state waters (out to 3 nmi) 
to 145 dB re: 1 [mu]Pa rms.
    Regarding seamounts, Morato et al. (2010) state that seamounts were 
found to have higher species diversity within 30-40 km of the summit 
and tended to aggregate some visitor species (Morato et al., 2010). 
However, as stated by the authors, the paper did not demonstrate that 
this behavior can be generalized. Further, the authors note that 
associations with seamounts have been described for some species of 
marine mammals (Morato et al., 2008), mostly on an individual seamount 
scale.

[[Page 40196]]

Morato et al. (2008) examined seamounts for their effect on aggregating 
visitors and noted that seamounts may act as feeding stations for some 
visitors, but not all seamounts seem to be equally important for these 
associations. While Morato et al. (2008) only examined seamounts in the 
Azores, the authors noted that only seamounts shallower than 400 m 
depth showed significant aggregation effects. Their results indicated 
that some marine predators (common dolphin (Delphinus delphis) and 
other non-marine mammal species (such as fish and invertebrates) were 
significantly more abundant in the vicinity of some shallow-water 
seamount summits; there was no demonstrated seamount association for 
bottlenose dolphins (Tursiops truncatus), spotted dolphin (Stenella 
frontalis), or sperm whales (Physeter macrocephalus).
    Along the northeastern U.S. continental shelf, cetaceans tend to 
frequent regions based on food preferences (i.e., areas where preferred 
prey aggregate), with picscivores (fish-eating, e.g., humpback, fin, 
and minke whales as well as bottlenose, Atlantic white-sided, and 
common dolphins) being most abundant over shallow banks in the western 
Gulf of Maine and mid-shelf east of Chesapeake Bay; planktivores 
(plankton-eating, e.g., right, blue, and sei whales) being most 
abundant in the western Gulf of Maine and over the western and southern 
portions of Georges Bank; and teuthivores (squid eaters, e.g., sperm 
whales) most abundant at the shelf edge (Fiedler, 2002). While there 
have been observations of humpback whales lingering at seamounts in the 
middle of the North Pacific on the way to summer feeding grounds in the 
Gulf of Alaska (Mate et al., 2007), the purpose of these occurrences is 
not clear, and it may be that they are feeding, regrouping, or simply 
using them for navigation (Fiedler, 2002; Mate et al., 2007); 
therefore, the role of the seamount habitat is not clear. According to 
Pitcher et al. (2007), there have been very few observations of high 
phytoplankton biomass (i.e., high primary production, usually estimated 
from chlorophyll concentrations) over seamounts. Where such effects 
have been reported, all were from seamounts with summits shallower than 
300 m, and the effects were not persistent, lasting only a few days at 
most. Therefore, it may be that food sources for many baleen whales are 
not concentrated in great enough quantities for significant enough time 
periods to serve as important feeding areas. While some odontocete 
(toothed) whales have been suggested to utilize seamount features for 
prey capture (Pitcher et al., 2007), the authors conclude that the 
available evidence suggests that ``unlike many other members of 
seamount communities, the vast majority of marine mammal species are 
probably only loosely associated with particular seamounts.'' We note 
here that marine mammals being ``loosely associated'' with seamounts, 
or being observed lingering at certain seamounts, does not necessarily 
suggest a level of biological importance that would support 
geographical restrictions to avoid all seamounts, or even the specific 
seamounts where these loose aggregations occur. Further, as stated 
above, the short term, intermittent nature of the exposures to SURTASS 
LFA sonar would be unlikely to impact the fitness (via effects on 
reproduction or survival) of any individuals, especially given the 
existing/proposed mitigation. Therefore, considered with the uncertain 
potential of this proposed measure to provide meaningful additional 
reduction of impacts to individual marine mammals, this measure is not 
expected to provide a reduction in the probability or degree of effects 
on any marine mammal species or stocks.
    Consideration of practicability for restrictions within 100 km of 
all islands and seamounts that rise to within 500 m of the surface--
Please see the discussion of practicability for the White Paper 
recommendation above (protection of continental slope and a 100 km 
buffer), which is also applicable here. NMFS and the Navy evaluated the 
practicability of implementation of the White Paper's recommendation 
regarding island and seamounts that rise to within 500 m of the sea 
surface. The Navy has indicated, and NMFS concurs, that restrictions 
within 100 km of all islands and seamounts that rise to within 500 m of 
the surface beyond the existing coastal standoff and OBIAs would 
unacceptably impact their national security mission. Adequate and 
effective training and testing with SURTASS LFA is necessary to ensure 
crews can operationally detect quieter and harder to-find foreign 
submarines at greater distances. The Navy has indicated that if large 
areas of the continental shelf or slope were restricted beyond what is 
in the 12nmi/22km coastal standoff, the Navy would not have the benefit 
of being able to train and test in these challenging environments. 
Coastal, shallow environments are more acoustically complex and the 
SURTASS LFA system was designed to penetrate these environments to find 
quiet assets that may use these distinctive geographic features to 
their advantage. Year-round access to all of these areas of challenging 
topography and bathymetry is necessary so that crews learn how the 
SURTASS LFA system will operate amidst changing oceanographic 
conditions, including seasonal variations that occur in sound 
propagation.
    As discussed previously with respect to a 100 km buffer around 
continental shelf and slope habitat, similar practicability concerns 
exist with implementing a 100 km buffer around all islands and 
seamounts. Because these assets are forward deployed and can rapidly 
switch between training and testing activities and operational 
missions, there is limited flexibility for these ships to maneuver any 
substantial distance from their primary mission areas of 
responsibility. Since seamounts and other areas of complex bathymetry 
are important training/testing features avoiding these areas would have 
negative impacts on training and testing preparedness and realism. 
Additionally, avoiding island associated and sea mount habitats by 100 
km would constitute a significant deviation in the staging of these 
assets for other missions and would significantly impacting their 
potential for these vessels to conduct operational missions. Lastly, 
due to the slow speed at which these vessels transit (3 to 4 kt when 
towing SURTASS, 10-12 kt without) it does not allow for large scale 
movements on the orders of a 100 km proposed by the mitigation scheme 
of the White Paper without requiring extensive transmit time on and off 
station that would reduce training and testing opportunities and the 
ability of these assets to support other national security missions 
required of them.
    Conclusion regarding restrictions within 100 km of all islands and 
seamounts that rise to within 500 m of the surface--In summary, while 
restricting LFA sonar training and testing in areas 100 km seaward from 
islands and seamounts could potentially reduce incidences of take 
within a limited number of species in preferred habitat in some cases 
(potential feeding), available data indicate that marine mammal 
associations within these areas are limited and the benefits would be 
at best limited and/or ephemeral. Also, the habitat preferences for 
these areas seem to be more associated with mid and high frequency 
species, which are less sensitive to LFA sonar, thereby further 
lessening concern for the potential effects of LFA sonar. Limiting 
SURTASS LFA sonar training

[[Page 40197]]

and testing activities in these large areas when activities are already 
comparatively low (small number of ships operating up to a maximum of 
496 transmission hours total across all vessels in years 1-4 and 592 
total transmission hours in years 5 and beyond pooled across all 
vessels, spread across several mission areas and over the course of an 
entire year) and the existing risks to the affected species and stocks 
are already so low, would provide little, if any, value for lowering 
the probability or severity of impacts to individual marine mammal 
fitness, much less species or stocks, or their habitat. Given the 
limited potential for additional reduction of impacts to a small number 
of marine mammal species and the high degree of impracticability 
(serious impacts on mission effectiveness), NMFS has determined that 
adopting this recommendation is not warranted under the LPAI standard.
High Productivity Regions That Are Not Included in the Continental 
Shelf, Continental Slope, Seamount, and Island Ecosystems
    Consideration of potential for reduction of adverse impacts to 
marine mammal species and stocks and their habitat--Regions of high 
productivity have the potential to provide good foraging habitat for 
some species of marine mammals at certain times of the year and could 
potentially correlate with either higher densities and/or feeding 
behaviors through parts of their area. Productive areas of the ocean 
are difficult to consistently define due to interannual spatial and 
temporal variability. High productivity areas have ephemeral boundaries 
that are difficult to define and do not always persist interannually or 
within the same defined region. While there is not one definitive guide 
to the productive areas of the oceans, NMFS and the Navy examined these 
areas in the SURTASS LFA sonar study area. For instance, Huston and 
Wolverton (2009) show areas of high/highest productivity that are 
either (1) confined to high latitude (polar) areas that are not in the 
SURTASS LFA sonar Study Area, or (2) very coastally and typically 
seasonally associated with areas of high coastal runoff (i.e., by river 
mouths), which are already encompassed by the coastal standoff range.
    Areas of more moderate productivity are typically very large, which 
means that they are not concentrating high densities or feeding areas 
throughout their area. In fact, areas of moderate productivity scored 
within the mean and thus represent ``average'' habitat and would not 
necessarily be biologically important. These moderately productive 
habitats are likely to provide ample alternative opportunities for 
species to move into and take advantage of areas should they avoid the 
area around the SURTASS LFA sonar vessel. Additionally, as noted above, 
given the nature of SURTASS LFA sonar activities and the other 
mitigation for SURTASS LFA sonar, the existing risk to marine mammal 
species and stocks is low and is limited to less severe Level B 
harassment.
    Consideration of practicability for restrictions for high 
productivity regions that are not included in the continental shelf, 
continental slope, seamount, and island ecosystems--NMFS and the Navy 
evaluated the practicability of implementation of the White Paper's 
recommended restrictions on high productivity areas. Please see the 
discussion of practicability for the first White Paper recommendation 
above (continental slope plus buffer), which is also applicable here. 
The Navy has indicated, and NMFS concurs, that, additional restrictions 
in high productivity regions that are not included in the continental 
shelf, continental slope, seamount, and island ecosystems beyond the 
existing coastal standoff and OBIAs would unacceptably impact its 
national security mission. Because of the inconsistent and ephemeral 
boundaries associated with most high productivity regions, it would be 
difficult to define geographic restrictions that would not impinge upon 
the long-range detection abilities of the SURTASS LFA sonar system. The 
mission of SURTASS LFA sonar is to detect quieter and harder-to-find 
foreign submarines at greater distances. The Navy must train and test 
in open ocean regions to track relevant targets at long distances. If 
large areas of the ocean were excluded from potential usage, the Navy 
would not have the benefit of being able to train and test at the long 
ranges for which SURTASS LFA sonar has been designed to function most 
effectively. Further, because high productivity areas are highly 
variable and ephemeral, implementation would not be operationally 
practicable for the Navy.
    Conclusion regarding restrictions in high productivity regions that 
are not included in the continental shelf, continental slope, seamount, 
and island ecosystems-- Restricting use of SURTASS LFA sonar training 
and testing seasonally in high productivity areas could potentially 
reduce take numbers for certain species in preferred or feeding habitat 
in some cases. However, as noted above, the size of the primary 
productivity areas is such that animals could likely easily access 
adjacent high productivity areas should they be temporarily diverted 
away from a particular area due to a SURTASS LFA sonar source. In 
addition, marine mammals are not concentrated through all, or even 
most, of these large areas for all, or even most, of the time when 
productivity is highest. Therefore, a broad limitation of this nature 
would likely unnecessarily limit LFA sonar activities while providing 
only some slight benefit to a limited number of individuals, which 
would not rise to the level of value to marine mammal species or 
stocks. Limiting activities in these large areas when activities are 
already comparatively low (small number of ships operating up to a 
maximum of 496 transmission hours total across all vessels in years 1-4 
and 592 total transmission hours in years 5 and beyond pooled across 
all vessels, spread across several mission areas and over the course of 
an entire year), given the existing risks to the affected species and 
stocks are already so low, would provide little, if any, value for 
lowering the probability or severity of impacts to individual marine 
mammal fitness, much less species or stocks, or their habitat. While we 
note that subjecting entire ``high productivity regions'' to 
geographical restrictions would provide little value, we also reiterate 
that over half of the existing OBIAs previously identified are in areas 
categorized as Class I (high productivity, >300 gC/m2-yr) or Class II 
(moderate productivity, 150-300 gC/m2-yr) ecosystems, based on SeaWiFS 
global primary productivity (see response to NRDC comment 20, 77 FR 
50290, 50304 (August 20, 2012)). However, we also note that high 
productivity/foraging was not necessarily the qualifying criteria for 
all of these OBIAs, and being classified as a high productivity area 
does not necessarily mean the area serves as a biologically important 
area for marine mammal foraging. Given the limited potential for 
additional reduction of impacts to marine mammal species and the high 
degree of impracticability (serious impacts on mission effectiveness), 
NMFS has determined that adopting this recommendation is not warranted 
under the LPAI standard.
Overall Conclusion Regarding Consideration of the White Paper 
Recommendations
    NMFS has considered the White Paper recommendations and 
acknowledges that some of them have the potential to reduce the numbers 
of take for some individual marine mammals within a limited number of

[[Page 40198]]

species, while in other cases, adopting the White Paper's guidelines 
could potentially increase take of other species. NMFS also 
acknowledges that the White Paper's recommendations may add some small 
degree of protection in preferred habitat or during feeding behaviors 
in certain circumstances. However, the potential for impacts on 
reproduction or survival of any individuals, much less accrual to 
population level impacts, with the existing mitigation is already very 
low. As explained above, the minimal training and testing impacts and 
the anticipated, and demonstrated, success of the significant 
mitigation measures that the Navy is already implementing, provide a 
large degree of protection and limit takes to less severe Level B 
harassment. Therefore, the highly limited and uncertain likelihood that 
the White Paper recommendations will further reduce impacts on 
individual marine mammal fitness, much less the affected species or 
stocks, and their habitat does not justify adopting the 
recommendations, especially when considered in light of the high degree 
of impracticability for Navy implementation.

Least Practicable Adverse Impact--Conclusions

    Based on our evaluation of the Navy's proposed mitigation measures 
as well as other measures considered by NMFS or recommended by the 
public, NMFS has determined that the mitigation measures required by 
this final rule provide the means of effecting the least practicable 
adverse impact on the affected species or stock(s) of marine mammals 
and their habitat, paying particular attention to rookeries, mating 
grounds, and areas of similar significance, considering personnel 
safety, practicality of implementation, and impact on the effectiveness 
of the military readiness activity.
    The 2,000-yd LFA sonar mitigation (shutdown) zone, based on 
detection of marine mammals from the highly effective three-part 
mitigation monitoring efforts (visual, as well as active and passive 
acoustic monitoring), and geographic restrictions (coastal standoff 
zone and OBIAs plus the 1-km buffer as well as the limitation on 
transmission hours near OBIAs except when additional approval is 
obtained from the Navy Command authority if required for national 
security) will enable the Navy to: (1) Avoid Level A harassment of 
marine mammals; (2) minimize the incidences of marine mammals exposed 
to SURTASS LFA sonar sound levels associated with TTS and more severe 
behavioral effects under Level B harassment; and (3) minimize marine 
mammal takes in areas and during times of important behaviors such as 
feeding, migrating, calving, or breeding or in areas where small 
resident populations reside or there is high density, further 
minimizing the likelihood of adverse impacts to species or stocks.
    The SURTASS LFA sonar signal is not expected to cause mortality, 
serious injury, or PTS, due to implementation of the 2,000-yd LFA sonar 
mitigation zone, which will ensure that no marine mammals are exposed 
to an SPL greater than about 174 dB re: 1 [micro]Pa rms. As discussed 
above, a low-frequency cetacean would need to remain within 41 meters 
(135 ft) for an entire LFA sonar transmission (60 sec) to potentially 
experience PTS and within 413 m (1,345 ft) for an entire LFA sonar 
transmission (60 sec) to potentially experience TTS, which would be 
unlikely given typical avoidance behaviors even in the absence of 
mitigation. Therefore, in addition to alleviating the likelihood of 
PTS, the implementation of the 2,000-yd LFA sonar shutdown zone 
mitigation measure will minimize the number of LF cetaceans likely 
exposed to LFA sonar at levels associated with the onset of TTS. The 
best information available indicates that effects from SPLs less than 
180 dB re: 1 [micro]Pa rms will be limited to short-term, Level B 
harassment, and animals are expected to return to behaviors shortly 
after exposure.
    Further, the implementation of OBIA measures and the coastal 
standoff allows the Navy to minimize or avoid impacts in areas where 
behavioral disturbance and other impacts would be more likely to have 
negative energetic effects, or deleterious effects on reproduction, 
which could reduce the likelihood of survival or reproductive success 
(measures to avoid or lessen exposures of marine mammals within the 
coastal standoff zone and OBIAs); and generally lessen the total number 
of takes in areas of higher density for some species (coastal standoff 
measures and OBIAs). These measures, taken together, constitute the 
means of effecting the least practicable adverse impact on the affected 
species and stocks in the western and central North Pacific and eastern 
Indian Oceans in the upcoming seven-year LOA period. As described 
above, we evaluated the potential inclusion of additional measures 
(White Paper recommendations, critical habitat, etc.) before reaching 
this conclusion.
    The 2019 SURTASS LFA FSEIS/SOEIS evaluated the potential for 
impacts to marine habitats (marine mammals and otherwise) from SURTASS 
LFA sonar training and testing activities including critical habitat, 
essential fish habitat, marine protected areas, and national marine 
sanctuaries. SURTASS LFA sonar training and testing activities involve 
introduction of pressure and sound in the water column but will not 
alter physical habitat. Marine mammal prey will not be exposed to 
sustained duration and intensity of sound levels that would be expected 
to result in significant adverse effects to marine mammal food 
resources. Habitat impacts were considered within the context of the 
addition of sound energy to the marine environment while SURTASS LFA 
sonar is transmitting, which represents a vanishingly small percentage 
of the overall annual underwater acoustic energy budget that would not 
affect the ambient noise environment of marine habitats (refer to 
Chapter 4, Sections 4.4 and 4.5 of the 2019 SURTASS LFA FSEIS/SOEIS). 
Therefore, with regard to habitat, NMFS has not identified any impacts 
to habitat from SURTASS LFA sonar that persist beyond the time and 
space that the impacts to marine mammals themselves and the water 
column could occur. Our mitigation targeted to minimize impacts to 
species or stocks while in particular habitats (i.e., the coastal 
standoff and OBIAs) will protect preferred habitat during its use, and 
therefore is contributing to the means of effecting the LPAI on a 
species or stock and its habitat. Therefore, the mitigation measures 
that address areas that serve as important habitat for marine mammals 
in all or part of the year help effectuate the LPAI on marine mammal 
species and stocks and their habitat.
    The Ninth Circuit's Pritzker decision faulted NMFS for considering 
the White Paper mitigation recommendations for ``data-poor areas'' 
against the OBIA standards NMFS had set for the 2012 rule. We do not 
read the opinion as holding that the MMPA compelled a change in the 
criteria and process for evaluating OBIAs. NMFS addressed the Court's 
decision by separately and independently evaluating the White Paper's 
recommendations for benefits to the affected species or stocks and 
practicability, without regard to the OBIA criteria or process (see 
NMFS' evaluation of the White Paper in this rule). Using the best 
available information, NMFS considered the recommendations in the White 
Paper under our interpretation of the LPAI standard and determined the 
measures (as well as a smaller buffer distance)

[[Page 40199]]

were not warranted, as described in that section.
    In reaching the conclusion that NMFS' record for the 2012 rule did 
not establish the agency had satisfied the LPAI standard, the Court in 
Pritzker determined that NMFS failed to consider an important aspect of 
the problem, ``namely the underprotection that accompanies making 
conclusive data an indispensable component of OBIA designation,'' and 
that this ``systematic underprotection of marine mammals'' cannot be 
consistent with the requirement that mitigation measures result in the 
``least practicable adverse impact'' on marine mammals.'' Id. at 1140. 
While we have corrected the identified deficiency by evaluating the 
White Paper measures independent of the OBIA process, we disagree with 
the suggestion that our mitigation is systematically underprotective.
    We first emphasize that NMFS' OBIA informational standards (and 
other mitigation measures), while data-driven, do not require 
scientific certainty or conclusive data. This is illustrated by the 
fact that the OBIA screening criteria allow for consideration of a 
variety of information sources, including historic whaling data, 
stranding data, sightings information, and regional expertise, to name 
a few examples of the ``data'' considered--and, in fact, the only areas 
that were not considered were those considered to have entirely 
inconclusive data. As detailed further in Appendix D of the 2012 
SURTASS LFA SEIS/SOEIS, supporting documents that are considered 
include peer-reviewed articles; scientific committee reports; cruise 
reports and transects; personal communications and unpublished reports; 
dissertations and theses; books, government reports, and non-
governmental organization reports; and notes, abstracts, and conference 
proceedings. The process set up for the 2012 rule carried forward areas 
for consideration if they had sufficient scientific support for the 
relevant criterion based on a ranking of 2 or higher on a scale 
developed for that purpose, with zero being the lowest and four the 
highest. Even areas that were ranked ``2'' (``Supporting information 
derived from habitat suitability models (non-peer reviewed), expert 
opinion, regional expertise, or gray (non-peer reviewed) literature, 
but requires more justification'') were deemed ``eligible'' for further 
consideration (77 FR 50290, 50299 (August 20, 2012)).
    In fact, NMFS has previously designated OBIAs for areas based on 
these types of information sources. For example, the Olympic Coast OBIA 
(OBIA 21) had a ranking of 2 for foraging by humpback whales as 
documented in one peer-reviewed report (p.D-319, DoN 2012). Based on 
the results of that study, the Olympic Coast OBIA was reviewed and 
designated. Other examples include the Southwest Australia Canyons 
OBIA, which considers past whaling data but also more recent sighting 
and stranding information; and the boundary for the Eastern Gulf of 
Mexico OBIA, which was drawn to ``conservatively encompass'' waters 
where Bryde's whales may occur based on sightings information (as 
opposed to scientific validation of their occurrence). In addition, 
even though most available data are only available for inshore waters 
(within the coastal standoff zone), NMFS is designating OBIAs for the 
Ogasawara Island region as part of this rulemaking due to the 
importance of the nearshore area for humpback whales and sperm whales.
    Thus, NMFS does not insist on an ``unattainable'' evidentiary 
standard of ``conclusive data'' \7\ for imposing conservation and 
management measures for SURTASS LFA sonar, including OBIAs. As another 
example, the coastal standoff zone uniformly applies not only in areas 
with supporting data about marine mammals (80 percent of the areas 
initially identified for OBIA consideration were within the 12 nmi/22 
km coastal standoff) but also in areas that could be fairly 
characterized as ``data poor.''
---------------------------------------------------------------------------

    \7\ NRDC v. Pritzker, 828 F.3d 1125, 1140 (9th Cir. 2016).
---------------------------------------------------------------------------

    Finally, because the LPAI standard authorizes NMFS to weigh a 
variety of factors when evaluating appropriate mitigation measures, it 
does not compel mitigation for every kind of individual take, even when 
practicable for implementation by the applicant. Thus, we do not 
evaluate measures strictly on the basis of whether they will reduce 
taking. The focus is on the relevant contextual factors that more 
meaningfully assess a measure's value in contributing to the standard 
of minimizing impacts to the affected species or stock and its habitat. 
It is also relevant to consider a measure in the context of the nature 
and extent of the expected impacts of the specified activity and the 
value of other mitigation that will be implemented.
    NMFS has evaluated the likely effects of SURTASS LFA sonar training 
and testing activities and has required measures to minimize the 
impacts to the affected species or stocks and their habitat to achieve 
the LPAI. Consistent with our interpretation of LPAI, the LFA shutdown 
and coastal exclusion zone are practicable for the Navy and effective 
in minimizing impacts on marine mammals from activities that are likely 
to increase the probability or severity of population level effects--
wherever marine mammals occur, even in areas where data are limited. 
Therefore, as we have said, NMFS' mitigation requirements are not based 
on the premise that the ``no data'' scenario is equivalent to ``zero 
population density'' or ``no biological importance.'' \8\ The LFA 
shutdown zone will avoid or minimize auditory impacts and more severe 
forms of Level B harassment, wherever marine mammals occur. The coastal 
exclusion zone will reduce adverse impacts, specifically higher numbers 
of take or take in areas of preferred habitat for coastal species that 
are present in higher numbers, or through lessening the severity of 
impacts by minimizing take of individuals in shelf or slope areas 
encompassed by the standoff, when that habitat is preferred by some 
species (again, when NMFS assessed areas that met the OBIA biological 
criteria for the 2012 rule, 80 percent of the areas fell within the 12 
nmi coastal exclusion zone, but the protection applies anywhere in the 
coastal exclusion zone, even in parts that are ``data poor''). In 
addition, NMFS designated OBIAs, where supporting information 
sufficiently (and not necessarily conclusively) demonstrated the areas 
met the established criteria and they were determined to be 
practicable, which are expected to reduce the likelihood of impacts 
that would adversely affect reproduction or survival.
---------------------------------------------------------------------------

    \8\ White Paper at p. 1.
---------------------------------------------------------------------------

    We have assessed all recommendations and the best available science 
and are aware of no other practicable measures that would further 
reduce the probability of impacts to species or stocks and their 
habitats. In other words, the measures that NMFS includes in this rule 
will effect the least practicable adverse impact on the affected 
species or stocks and their habitats. As discussed in the Adaptive 
Management section, NMFS will systematically consider new information 
and re-evaluate as necessary if applicable new information becomes 
available.

Monitoring

    Section 101(a)(5)(A) of the MMPA states that in order to issue an 
ITA for an activity, NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking.'' The MMPA implementing

[[Page 40200]]

regulations at 50 CFR 216.104(a)(13) indicate that requests for LOAs 
must include the suggested means of accomplishing the necessary 
monitoring and reporting that will result in increased knowledge of the 
species, the level of taking, or impacts on populations of marine 
mammals that are expected to be present.
    Monitoring measures prescribed by NMFS should accomplish one or 
more of the following general goals:
     An increase in our understanding of how many marine 
mammals are likely to be exposed to levels of LFA sonar that we 
associate with specific adverse effects, such as disruption of 
behavioral patterns, TTS, or PTS;
     An increase in our understanding of how individual marine 
mammals respond (behaviorally or physiologically) to LFA sonar (at 
specific received levels or other stimuli expected to result in take);
     An increase in our understanding of how anticipated takes 
of individuals (in different ways and to varying degrees) may impact 
the population, species, or stock (specifically through effects on 
annual rates of recruitment or survival);
     An increase in knowledge of the affected species;
     An increase in our understanding of the effectiveness of 
certain mitigation and monitoring measures;
     A better understanding and record of the manner in which 
the authorized entity complies with the incidental take authorization; 
and
     An increase in the probability of detecting marine 
mammals, both within the mitigation zone (thus allowing for more 
effective implementation of the mitigation) and in general to better 
achieve the above goals.
    In addition to the real-time monitoring associated with mitigation, 
the Navy is engaging in exploring other monitoring efforts described 
here:

Marine Mammal Monitoring (M3) Program

    Beginning in 1993, the Marine Mammal Monitoring (M3) Program was 
designed to assess the feasibility of detecting and tracking marine 
mammals. The M3 program uses the Navy's fixed and mobile passive 
acoustic monitoring systems to monitor the movements of some large 
cetaceans (principally baleen whales), including their migration and 
feeding patterns, by tracking them through their vocalizations. This 
Program has evolved into a valuable tool by which the acoustic activity 
levels of vocalizing whales can be quantitatively documented and trends 
of oceanic ocean noise levels measured over ecologically meaningful 
ocean scales and time periods under varying noise conditions.
    As part of the research and monitoring component of the SURTASS LFA 
sonar program, M3 data are collected to:
     Document occurrence, distribution, and behaviors of 
acoustically active whale species over ocean basin and decadal scales;
     Assess changes in marine mammal activity levels under 
normal conditions (e.g., weather, wind, time of year, or time of day) 
relative to acoustic conditions with varying levels of anthropogenic 
noise (e.g., seismic activities, naval sonar, shipping, or fishing 
activities);
     Inform environmental assessments of current and future 
anti-submarine warfare systems; and
     Assemble a long-term database of ocean ambient noise data 
to enable scientifically-based evaluations of potential influences on 
cetaceans or other species.
    Acoustic data collected and archived by the M3 program allow 
program analysts to statistically quantify how cetacean acoustic 
behaviors are affected by various factors, such as ocean basin 
topographic features, hydrographic conditions, seasonality, time, 
weather conditions, and ambient noise conditions. The compiled acoustic 
data can be used to estimate the total number of vocalizing whales per 
unit area as well as document the seasonal or localized movements of 
individual animals. In addition, observations over time can also show 
the interaction and influence of noise sources on large whale behavior.
    At present, the M3 Program's data are classified, as are the data 
reports created by M3 Program analysts, due to the inclusion of 
sensitive national security information. The Navy continues to assess 
and analyze M3 Program data collected from Navy passive acoustic 
monitoring systems and is working toward making some portion of that 
data (after appropriate security reviews) available to scientists with 
appropriate clearances and ultimately to the public. Additionally, data 
summaries are shared with NMFS analysts with appropriate clearances. 
There has been some progress on addressing security concerns and 
declassifying a report of fin whale singing and swimming behaviors 
(DoN, 2015; Clark et al., 2019). In addition, the Navy has shared 
information on detections of western gray whale vocalizations with the 
IUCN on possible wintering areas for this species.

Additional Ranked Monitoring Projects Under Consideration

    Due to research indicating that beaked whales and harbor porpoises 
may be particularly sensitive to a range of underwater sound (Southall 
et al., 2007; Tyack et al., 2011; Kastelein et al., 2012), in the 2012 
rule and LOAs for these activities, NMFS included conditions for 
increasing understanding of the potential effects of SURTASS LFA sonar 
on these taxa. The Navy convened an independent Scientific Advisory 
Group (SAG), composed of six scientists affiliated with two 
universities, one Federal agency (NMFS), and three private research and 
consultancy firms, to investigate and assess different types of 
research and monitoring methods that could increase the understanding 
of the potential effects to beaked whales and harbor porpoises from 
exposure to SURTASS LFA sonar transmissions. The SAG submitted a report 
(``Potential Effects of SURTASS LFA sonar on Beaked Whales and Harbor 
Porpoises'') describing their monitoring and research recommendations. 
This report was submitted to the Executive Oversight Group (EOG) for 
SURTASS LFA sonar, which is comprised of representatives from the U.S. 
Navy (Chair, OPNAV N2/N6F24), Office of the Deputy Assistant Secretary 
of the Navy for the Environment, Office of Naval Research, Navy Living 
Marine Resources Program, and the NMFS Office of Protected Resources 
(OPR) Permits and Conservation Division. The EOG met twice in 2014 to 
review and further discuss the research recommendations put forth by 
the SAG, the feasibility of implementing any of the research efforts, 
and existing budgetary constraints. Representatives from the Marine 
Mammal Commission also attended EOG meetings as observers. In addition 
to the SAG recommendations, promising suggestions for monitoring and 
research were recommended for consideration by the EOG. The EOG 
considered which efforts would be most effective, given existing 
budgetary constraints, and the Navy has submitted the outcome of this 
study to NMFS.
    In summary, after consideration of the SAG recommendations and the 
inputs provided by the EOG, the research monitoring studies were ranked 
as follows. In addition to the topic, the approximate cost of the 
research effort is also listed. Those study topics which the Navy has 
invested in since the EOG recommendations are also indicated below.
    The category of research recommendations that were ranked

[[Page 40201]]

highest included those estimated to cost less than $100,000.
    1. Desktop study of potential overlap of harbor porpoise habitat by 
SURTASS LFA sonar transmissions. The Navy funded this study and the 
report has been submitted to NMFS. In summary the report finds that, 
while harbor porpoises could potentially be exposed to SURTASS LFA 
sonar transmissions, exposure is likely to occur at reduced sound 
levels with limited potential for behavioral responses. The full report 
is available at https://www.surtass-lfa-eis.com.
    2. Review of existing high frequency acoustic recording package 
(HARP) data to determine spatiotemporal overlap with SURTASS LFA 
missions. NMFS consulted with scientists at NOAA's Pacific Islands 
Fisheries Science Center about deployments in the western and central 
North Pacific and Scripps Institution of Oceanography about deployments 
in the eastern North Pacific. Since the EOG, Baumann-Pickering et al. 
(2014) presented the results of over eleven cumulative years of HARP 
deployments in the North Pacific, which may overlap with SURTASS LFA 
missions. It would be fairly straightforward and require minimal cost 
to determine the spatiotemporal overlap of HARP deployments and LFA 
missions. If it was determined that overlap existed, the cost for data 
analysis would depend on the amount of overlap.
    The second-highest ranked group of recommendations consisted of 
studies that are estimated to cost in the $100,000-$500,000 range, but 
for which methodologies exist and implementation would extend existing 
studies.
    1. Targeted deployment of one HARP sensor in the western North 
Pacific for one year; approximate estimated cost of $250,000. The 
objective of this study would be to document beaked whale vocal 
behavior before, during, and after LFA sonar transmissions. Careful 
consideration of lessons learned from previous deployments would be 
needed to increase the probability of a successful project (i.e., 
Baumann-Pickering et al., 2014 and as described in the reports of 
previous studies using HARPs located at https://www.navy 
marinespeciesmonitoring.us/).
    2. Anatomical modeling of LF sound reception by beaked whales; 
approximate estimated cost of $150,000-$200,000. Since the EOG meetings 
in 2014, Cranford and Krysl (2015) presented a synthetic audiogram for 
a fin whale, predicted based predominantly on bone conduction of sound 
through the head to the ear. NMFS (2016) noted that the predicted 
audiogram does not match the typical U-shaped audiogram expected with 
normal hearing in mammals in that there is a ``hump'' at low 
frequencies and shallow roll-off of sensitivity at high frequencies. 
Given these difficulties, additional funding would be required to 
determine the source of the abnormal results. The Navy is continuing to 
invest in LF cetacean audiogram development and recently released a 
Broad Agency Announcement in coordination with the Subcommittee on 
Ocean Science and Technology--Ocean Noise and Marine Life Task force to 
make further investment in this area.
    The final group of recommendations are studies that require 
additional methodological developments and/or would cost greater than 
$500,000.
    1. Controlled exposure estimates (CEE) for beaked whales with an 
appropriate LF source. There are many complexities associated with this 
recommendation, even more so considering the results of the ongoing 
mid-frequency sonar behavioral response studies (BRS) demonstrating the 
importance of real-world exposures for characterizing behavioral 
responses. It is possible that existing LF sources already in use on 
Navy ranges could be surrogates for SURTASS LFA sonar, but such 
extrapolations would need to be considered carefully. SURTASS LFA sonar 
is currently authorized for use in the western and central North 
Pacific and Indian oceans, regions in which controlled exposure 
experiments (CEEs) have not been conducted, making experiments with the 
LFA sonar system itself particularly difficult. Given the cost and 
complexities associated with this recommendation, it was ranked as a 
lower priority. This recommendation should also be revisited with 
future development of tagging technologies for harbor porpoises.
    2. LF behavioral audiograms for harbor porpoise or LF auditory 
brainstem response/auditory evoked potential (ABR/AEP) audiograms for 
beaked whales. Since the EOG concluded, the Navy funded a study led by 
Dr. James Finneran (https://greenfleet.dodlive.mil/files/2017/05/LMRFactSheet_Project9.pdf) to correlate AEP measurements of hearing 
sensitivity with perceived loudness (Muslow et al., 2015). Part of this 
study included attempts to extend the LF range of AEP measurements, 
which may be transferable to studies of hearing sensitivity of harbor 
porpoise or beaked whales. There are difficulties with the transmission 
of LF sounds, in achieving the required power with manageable 
laboratory systems and creating a far-field sound field consistent 
across the measurement experiment. The final results of the study have 
not been published yet, but the study found that AEPs were only 
successful down to frequencies of 10 kHz for bottlenose dolphins (where 
10 kHz is the upper range of what is considered mid-frequency) and 1 
kHz for California sea lions (the upper range of what is considered 
low-frequency). In addition, the correlation of equal latency contours 
only applied over a limited frequency range, providing limited benefit 
beyond the frequency range of auditory thresholds. Therefore, it is 
currently not feasible to conduct ABR/AEPs at frequencies within the 
range of SURTASS LFA sonar (100 to 500 Hz). Finally, the Navy funded 
audiograms and TTS studies for harbor porpoise across its entire 
frequency range (Kastelein et al., 2017). This study reported the 
hearing sensitivity of a six-year-old female and a three-year-old male 
harbor porpoise as measured by using a standard psycho-acoustic 
technique under low ambient noise conditions. The porpoises' hearing 
thresholds for 13 narrow-band sweeps with center frequencies between 
0.125 and 150 kHz were established. The range of most sensitive hearing 
(defined as within 10 dB of maximum sensitivity) was from 16 to 140 
kHz. Sensitivity declined sharply above 125 kHz. Hearing sensitivity in 
the low frequencies 125 Hz to 1 kHz were 40-80 dB above their maximum 
sensitivity.
    The Navy has obtained a permit from the NMFS marine mammal health 
and stranding program to conduct an AEP audiogram on a stranded beaked 
whale, but to date none have stranded alive in an area with staff 
suitable to conduct the testing. The Navy will continue to seek 
opportunities to conduct such research should they arise.
    The ranking of research and monitoring recommendations has helped 
inform Navy and NMFS decision makers of the scientific priority, 
feasibility, and cost of possible experiments to increase understanding 
of potential effects of SURTASS LFA sonar on harbor porpoises and 
beaked whales. Discussions among Navy decision makers from OPNAV N2/
N974B/N45, Office of the Deputy Assistant Secretary of the Navy for the 
Environment, Office of Naval Research, and Navy Living Marine Resources 
Program will continue to leverage research among various programs. 
Ongoing discussions between Navy and NMFS will continue to evaluate the 
most efficient and cost-effective way forward for Navy research and 
environmental compliance monitoring

[[Page 40202]]

efforts once the amount of funding authorized is known.

Ambient Noise Data Monitoring

    Several efforts (Federal and academic) are underway to develop a 
comprehensive ocean noise budget (i.e., an accounting of the relative 
contributions of various underwater sources to the ocean noise field) 
for the world's oceans that includes both anthropogenic and natural 
sources of noise. Ocean noise distribution and noise budgets are used 
in marine mammal masking studies, habitat characterization, and marine 
animal impact analyses.
    The Navy will collect ambient noise data when the SURTASS passive 
towed horizontal line array is deployed. However, because the collected 
ambient noise data may also contain sensitive acoustic information, the 
Navy classifies the data, and thus does not make these data publicly 
available. The Navy is exploring the feasibility of declassifying and 
archiving portions of the ambient noise data for incorporation into 
appropriate ocean noise budget efforts after all related security 
concerns have been resolved.
    The Navy will evaluate the feasibility and appropriate methods to 
collect new data to supplement the data available on behavioral 
responses of marine mammals to SURTASS LFA sonar using newer methods 
and technologies. These types of scientific inquiries fit within the 
scope the Navy's Living Marine Resources (LMR) program. The LMR program 
weighs the various Navy research needs against each other through a 
needs and solicitation process. The Navy has submitted a needs 
statement to the LMR advisory committee to research future data 
collection that would supplement understanding of how SURTASS LFA sonar 
may affect marine resources, including mysticetes and beaked whales. 
The LMR program assesses Navy data needs through an iterative process 
in which each submitted need is evaluated and ranked by an advisory 
committee. Prior to implementing any potential behavioral response 
study, the feasibility must be evaluated and a research plan must be 
developed. The LMR process is the primary mechanism which the Navy uses 
to solicit expert assistance for marine resource investigations.

Research

    The Navy sponsors significant research for marine living resources 
to study the potential effects of its activities on marine mammals. 
OPNAV N974B provides a representative to the Navy's Living Marine 
Resources advisory board to provide input to future research projects 
that may address SURTASS LFA sonar needs. The most recently available 
data are for Fiscal Year 2015, in which the Navy reported that it spent 
$35.9 million that year on marine mammal research and conservation 
(Marine Mammal Commission, 2017). This ongoing marine mammal research 
relates to hearing and hearing sensitivity, auditory effects, marine 
mammal monitoring and detection, noise impacts, behavioral responses, 
diving physiology and physiological stress, and distribution. The Navy 
sponsors a significant portion of U.S. research on the effects of 
human-generated underwater sound on marine mammals and approximately 50 
percent of such research conducted worldwide. These research projects 
may not be specifically related to SURTASS LFA sonar activities; 
however, they are crucial to the overall knowledge base on marine 
mammals and the potential effects from underwater anthropogenic noise. 
The Navy also sponsors research to determine marine mammal abundances 
and densities for all Navy ranges and other operational areas. The Navy 
notes that research and evaluation is being carried out on various 
monitoring and mitigation methods, including passive acoustic 
monitoring, and the results from this research could be applicable to 
SURTASS LFA sonar passive acoustic monitoring. The Navy has also 
sponsored several workshops to evaluate the current state of knowledge 
and potential for future acoustic monitoring of marine mammals. The 
workshops bring together underwater acoustic subject matter experts and 
marine biologists from the Navy and other research organizations to 
present data and information on current acoustic monitoring research 
efforts, and to evaluate the potential for incorporating similar 
technology and methods on Navy instrumented ranges.

Reporting

    In order to issue an ITA 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 and to ensuring that the most value is 
obtained from the required monitoring. There are several different 
reporting requirements in these regulations:

Notification of the Discovery of a Stranded Marine Mammal \9\
---------------------------------------------------------------------------

    \9\ As defined in section 410 of the MMPA (16 U.S.C. 1421h), 
``stranding'' means ``an event in the wild in which (A) a marine 
mammal is dead and is (i) on a beach or shore of the United States, 
or (ii) in waters under the jurisdiction of the United States 
(including any navigable waters); or (B) a marine mammal is alive 
and is (i) on a beach or shore of the United States and unable to 
return to the water; (ii) on a beach or shore of the United States 
and, although able to return to the water, is in need of apparent 
medical attention; or (iii) in the waters under the jurisdiction of 
the United States (including any navigable waters), but is unable to 
return to its natural habitat under its own power or without 
assistance.''
---------------------------------------------------------------------------

    The Navy will systematically observe during SURTASS LFA sonar 
activities for injured or disabled marine mammals. In addition, the 
Navy will monitor the principal marine mammal stranding networks and 
other media to correlate analysis of any whale mass strandings that 
could potentially be associated with SURTASS LFA sonar activities.
Minimization of Harm to Live-Stranded (or Milling) Marine Mammals
    In the event of a live stranding (or near-shore atypical milling) 
event, NMFS will advise the Navy of the need to implement shutdown 
procedures for any use of SURTASS LFA sonar within 50 km (27 nmi) of 
the stranding. Following this initial shutdown, NMFS will communicate 
with the Navy to determine if circumstances support any modification of 
the shutdown zone. The Navy may decline to implement all or part of the 
shutdown if the holder of the LOA, or his/her designee, determines that 
it is necessary for national security. Shutdown procedures for live 
stranding or milling marine mammals include the following:
     If at any time, the marine mammal(s) die or are 
euthanized, or if herding/intervention efforts that were occurring are 
stopped, NMFS (individuals specifically identified in the Stranding 
Communication Protocol) will immediately advise the Navy that the 
shutdown around that animal(s)' location is no longer needed;
     Otherwise, shutdown procedures will remain in effect until 
NMFS (individuals specifically identified in the Stranding 
Communication Protocol) determines and advises the Navy that all live 
animals involved have left the area (either of their own volition or 
following an intervention); and
     If further observations of the marine mammals indicate the 
potential for re-stranding, additional coordination with the Navy may 
be required to determine what measures are necessary to minimize that 
likelihood (e.g.,

[[Page 40203]]

extending the shutdown or moving operations farther away) and to 
implement those measures as appropriate.
    Shutdown procedures are not related to the investigation of the 
cause of the stranding and their implementation is not intended to 
imply that Navy activity is the cause of the stranding. Rather, 
shutdown procedures are intended to protect marine mammals exhibiting 
indicators of distress by minimizing their exposure to possible 
additional stressors, regardless of the factors that contributed to the 
stranding.
Navy Discovery of Any Stranded Marine Mammal
    In the event that Navy personnel (uniformed military, civilian, or 
contractors conducting Navy work) associated with operating a T-AGOS 
class vessel discover a live or dead stranded marine mammal at sea, the 
Navy shall report the incident to NMFS (see communication protocols 
below) as soon as is feasible. The Navy will provide NMFS with:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
marine mammal(s) involved;
     Condition of the marine mammal(s) (including carcass 
condition if the marine mammal is dead);
     Observed behaviors of the marine mammal(s), if alive;
     If available, photographs or video footage of the marine 
mammal(s); and
     General circumstances under which the marine mammal was 
discovered (e.g., vessel transit).
Vessel Strike
    In the event of a ship strike of a marine mammal by any T-AGOS 
class vessel, the Navy shall immediately report, or as soon as security 
clearance procedures and safety conditions allow, the information above 
in Discovery of Any Stranded Marine Mammal subsection, to NMFS. As soon 
as feasible, but no later than seven (7) business days, the Navy shall 
additionally report to NMFS, the:
     Vessel's speed during and leading up to the incident;
     Vessel's course/heading and what training or testing 
activity was being conducted (if applicable);
     Status of all sound sources in use (e.g., active sonar);
     Description of avoidance measures/requirements that were 
in place at the time of the strike and what additional measures were 
taken, if any, to avoid marine mammal strike;
     Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, visibility) immediately preceding the 
marine mammal strike;
     Estimated size and length of marine mammal that was 
struck;
     Description of the behavior of the marine mammal 
immediately preceding and following the strike;
     If available, description of the presence and behavior of 
any other marine mammals immediately preceding the strike;
     Estimated fate of the marine mammal (e.g., dead, injured 
but alive, injured and moving, blood or tissue observed in the water, 
status unknown, disappeared, etc.);
     To the extent practicable, photographs or video footage of 
the struck marine mammal(s); and
     Any relevant information discovered during Navy's 
investigation of the ship strike.

Annual Report

    The classified and unclassified annual reports, which are due 
annually no later than 90 days after the anniversary of the effective 
date of the seven-year LOA, will provide NMFS with a summary of the 
prior year's training and testing transmission hours. Specifically, the 
classified reports will include dates/times of exercises, location of 
vessel, mission operational area, marine mammal observations, and 
records of any delays or suspensions of activities. Marine mammal 
observations will include animal type and/or species, number of animals 
sighted by species, date and time of observations, type of detection 
(visual, passive acoustic, HF/M3 sonar), the animal's bearing and range 
from vessel, behavior, and remarks/narrative (as necessary). The 
classified reports will also include the Navy's analysis of take by 
Level B harassment and estimates of the percentage of marine mammal 
stocks affected for the year by SURTASS LFA sonar training and testing 
activities. The Navy's estimates of the percentage of marine mammal 
stocks and number of individual marine mammals affected by exposure to 
SURTASS LFA sonar transmissions will be derived using acoustic impact 
modeling based on operating locations, season of missions, system 
characteristics, oceanographic environmental conditions, and marine 
mammal demographics.
    Additionally, the annual report will include: (1) Analysis of the 
effectiveness of the mitigation measures with recommendations for 
improvements where applicable; (2) assessment of any long-term effects 
from SURTASS LFA sonar activities; and (3) any discernible or estimated 
cumulative impacts from SURTASS LFA sonar training and testing 
activities.

Comprehensive Report

    The Navy will provide to NMFS and the public a final comprehensive 
report analyzing the impacts of SURTASS LFA sonar training and testing 
activities on marine mammal species and stocks. This report will 
include an in-depth analysis of all monitoring and Navy-funded research 
pertinent to SURTASS LFA sonar activities conducted during the seven-
year period of this rule, a scientific assessment of cumulative impacts 
on marine mammal stocks, and an analysis on the advancement of 
alternative (passive) technologies as a replacement for LFA sonar. This 
report will be a key document for NMFS' review and assessment of 
impacts for any future rulemaking.
    The Navy will respond to NMFS' comments and requests for additional 
information or clarification on the annual or comprehensive reports. 
These reports will be considered final after the Navy has adequately 
addressed NMFS' comments or provided the requested information, or 
three months after the submittal of the draft if NMFS does not comment 
within the three-month time period. NMFS will post the annual and 
comprehensive reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.

Adaptive Management

    Our understanding about marine mammals and the potential effects of 
SURTASS LFA sonar on marine mammals is continually evolving. Reflecting 
this, this final rule again includes an adaptive management framework. 
This allows the agencies to consider new/revised peer-reviewed and 
published scientific data and/or other information from qualified and 
recognized sources within academia, industry, and government/non-
government organizations to determine (with input regarding 
practicability) whether SURTASS LFA sonar mitigation, monitoring, or 
reporting measures should be modified (including additions or 
deletions), and to make such modification if new scientific data 
indicate that they would be appropriate. Under this final rule, 
substantial modifications will be made only after a 30-day period of 
public review and comment. Substantial modifications include a change 
in training and testing areas, or significant changes to mitigation.

[[Page 40204]]

    As discussed in the Mitigation section above, NMFS and Navy have 
refined the adaptive management process for this rule compared to 
previous rulemakings. In the 2012 rule, NMFS and the Navy annually 
considered how new information, from anywhere in the world, should be 
considered in an adaptive management context--including whether this 
new information would support the identification of new OBIAs or other 
mitigation measures. Moving forward, new information will still be 
considered annually, but only for the purposes of OBIA identification 
in the context of the areas covered by this rule (i.e., the Study Area 
in the western and central North Pacific and eastern Indian Oceans in 
which SURTASS LFA assets will train and test).

Negligible Impact Analysis and 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). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering the numbers of marine mammals that might be taken through 
mortality, serious injury, and Level A harassment or Level B harassment 
(although only Level B harassment is considered for authorization under 
this final rule), NMFS considers other factors, such as the likely 
nature of any responses (e.g., intensity and duration), the context of 
any response (e.g., critical reproductive time or location, migration, 
etc.), as well as effects on habitat, the status of the affected 
stocks, 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 are incorporated into these analyses 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, ongoing sources of human-caused mortality, or ambient 
noise levels).
    To avoid repetition, the discussion of our analyses applies to all 
the stocks listed in Table 17 (including those for which density and 
take estimates have been pooled), because the anticipated effects of 
the specified activities on these different marine mammal stocks are 
expected to be similar, given the operational parameters of the 
activities. While there are differences in the hearing sensitivity of 
different groups, these differences have been factored into the 
analysis for auditory impairment. However, the nature of their 
behavioral responses is expected to be similar for SURTASS LFA sonar, 
especially given the context of their short duration and open ocean 
exposures. Additionally, with the operational avoidance of areas (and 
additional transmission hour limitations year, no more than 124 hours 
in years 1-4 and 148 hours in years 5-7) that are designated for 
specific biologically important reasons and coastal standoff zones, and 
the anticipated low-level effects, there is no need to differentially 
evaluate species or stocks based on varying status. Where there is a 
notable difference in the proportion of authorized takes (as compared 
to abundance) for two species, we explicitly address it below.
    The Navy has described its specified activities based on best 
estimates of the number of hours that the Navy will conduct SURTASS LFA 
sonar training and testing activities. The exact number of transmission 
hours may vary from year to year, but will not exceed the annual total 
of 496 transmission hours for all vessels in years 1-4 (currently four 
vessels), or the annual total of 592 transmission hours for all vessels 
in years 5-7 regardless of the number of vessels in use (previous 
SURTASS LFA sonar rulemakings evaluated and authorized 432 transmission 
hours per vessel per year).
    As mentioned previously, NMFS estimates that 46 species of marine 
mammals representing 139 stocks could be taken by Level B harassment 
over the course of the seven-year period. For reasons stated 
previously, no mortalities or injuries are anticipated to occur as a 
result of the Navy's proposed SURTASS LFA sonar training and testing 
activities, and none are authorized by NMFS. The Navy has operated 
SURTASS LFA sonar under NMFS regulations for the last 17 years without 
any reports of serious injury or death. The evidence to date, including 
recent scientific reports, annual monitoring reports, and 17 years of 
Navy experience conducting SURTASS LFA sonar activities, further 
supports the conclusion that the potential for injury, and particularly 
serious injury, to occur is minimal.
    Regarding the potential for mortality, as described previously, 
neither acoustic impacts resulting in stranding nor ship strikes are 
expected to result from SURTASS LFA sonar training and testing 
activities. There is no empirical evidence of strandings or ship 
strikes of marine mammals associated spatially or temporally with the 
employment of SURTASS LFA sonar. Moreover, the sonar system acoustic 
characteristics differ between LFA sonar and MF sonars that have been 
associated with strandings: LFA sonars use frequencies from 100 to 500 
Hz, with relatively long signals (pulses, with average length of 60 
sec), while MF sonars use frequencies greater than 1,000 Hz, with 
relatively short signals on the order of 1 sec. NMFS also makes a 
distinction between the common features shared by the stranding events 
associated with MF sonar in Greece (1996), Bahamas (2000), Madeira 
(2000), Canary Islands (2002), Hanalei Bay (2004), and Spain (2006), 
referenced in the Potential Effects of Specified Activities on Marine 
Mammals and Their Habitat section of the proposed rule (84 FR 7186; 
March 1, 2019). These included operation of MF sonar, deep water close 
to land (such as offshore canyons), presence of an acoustic waveguide 
(surface duct conditions), and periodic sequences of transient pulses 
(i.e., rapid onset and decay times) generated at depths less than 32.8 
ft (10 m) by sound sources moving at speeds of 2.6 m/s (5.1 knots) or 
more during sonar operations (D'Spain et al., 2006). None of these 
factors are present in SURTASS LFA sonar training and testing 
activities. Regarding the potential for ship strike, given the small 
number of vessels, low densities of marine mammals in the area of 
operation, mitigation, and slow ship speeds, the potential of strike is 
so low as to be discountable.
    NMFS neither anticipates nor authorizes Level A harassment of 
marine mammals as a result of specified activities. The mitigation 
measures (including visual monitoring along with active and passive 
acoustic monitoring, which together have been shown to be over 98 
percent effective at detecting marine mammals, approaching 100 percent 
for multiple HF/M3 pings of any sized marine mammal), and implementing 
a shutdown zone of 2,000 yds around the LFA sonar array and vessel) 
would allow the Navy to avoid exposing marine mammals to received 
levels of SURTASS LFA sonar or HF/M3 sonar sound that would result in 
injury (Level A harassment). Additionally, as discussed in the 
Estimated Take of

[[Page 40205]]

Marine Mammals section, TTS and more severe behavioral reactions will 
also be minimized due to mitigation measures, so that the majority of 
takes will be expected to be in the form of less severe Level B 
harassment.
    As noted above, the context of exposures is important in evaluating 
the ultimate impacts of Level B harassment on individuals. In the case 
of SURTASS LFA sonar, the approaching sound source would be moving 
through the open ocean at low speeds, so concerns of noise exposure are 
somewhat lower in this context compared to situations where animals may 
not be as able to avoid strong or rapidly approaching sound sources. In 
addition, the duration of the take is important; in the case of SURTASS 
LFA sonar, the vessel continues to move and any interruption of 
behavior would be of relatively short duration. Further, NMFS and the 
Navy have imposed geographic restrictions that minimize behavioral 
disruption in times and areas where impacts would be more likely to 
lead to effects on individual fitness that could impact the species or 
stock.
    For SURTASS LFA sonar training and testing activities, the Navy 
provided information (Table 7-1 of the Navy's application) estimating 
incidental take numbers and percentages of marine mammal stocks that 
could potentially occur due to SURTASS LFA sonar training and testing 
activities based on the 15 model areas in the central and western North 
Pacific and eastern Indian Oceans. Based on our evaluation, incidental 
take from the specified activities associated with SURTASS LFA sonar 
training and testing activities will most likely fall within the realm 
of short-term and temporary, or ephemeral, disruption of behavioral 
patterns (Level B harassment), will not include Level A harassment, and 
is not expected to impact reproduction or survival of individuals. NMFS 
bases this assessment on a number of factors (discussed in more detail 
in previous sections) considered together:
    (1) Geographic Restrictions--The coastal standoff and OBIA 
geographic restrictions on SURTASS LFA sonar training and testing 
activities are expected to minimize the likelihood of disruption of 
marine mammals in areas where important behavior patterns such as 
migration, calving, breeding, feeding, or sheltering occur, or in areas 
with small resident populations or higher densities of marine mammals. 
As a result, the takes that occur are less likely to result in 
energetic effects or disturbances of other important behaviors that 
would reduce reproductive success or survivorship.
    (2) Low Frequency Sonar Scientific Research Program (LFS SRP)--The 
Navy designed the three-phase LFS SRP study to assess the potential 
impacts of SURTASS LFA sonar on the behavior of low-frequency hearing 
specialists, those species believed to be at (potentially) greatest 
risk due to the presumed overlap in hearing of these species and the 
frequencies at which SURTASS LFA sonar is operated. This field research 
addressed three important behavioral contexts for baleen whales: (1) 
Blue and fin whales feeding in the southern California Bight, (2) gray 
whales migrating past the central California coast, and (3) humpback 
whales breeding off Hawaii. These experiments, which exposed baleen 
whales to received levels ranging from 120 to approximately 155 dB re: 
1 [mu]Pa, confirmed that some portion of the total number of whales 
exposed to LFA sonar responded behaviorally by changing their vocal 
activity, moving away from the source vessel, or both, but the 
responses were short-lived and animals returned to their normal 
activities within tens of minutes after initial exposure. While some of 
the observed responses would likely be considered ``take'' under the 
MMPA, these short-term behavioral responses do not necessarily 
constitute significant changes in biologically important behaviors, 
such as those that might be expected to affect individual fitness. In 
addition, these experiments illustrated that the context of an exposure 
scenario is important for determining the probability, magnitude, and 
duration of a response. This was shown by the fact that migrating gray 
whales responded to a sound source in the middle of their migration 
route but showed no response to the same sound source when it was 
located father offshore, outside the migratory corridor, even when the 
source level was increased to maintain the same received levels within 
the migratory corridor.
    Although the LFS SRP study is two decades old, the collected 
behavioral response data remain valid and highly relevant because of 
the lack of additional studies utilizing this specific source, but also 
because the data show, as reflected in newer studies with other sound 
sources, that the context of an exposure (novelty of the sound source, 
distance from the sound source and activity of the animals experiencing 
exposure, and whether the source is perceived as approaching or moving 
away, etc.) is as important as, the source level and frequency in terms 
of assessing reactions (see the Behavioral Response/Disturbance section 
of the Potential Effects of Specified Activities on Marine Mammals and 
Their Habitat section in the proposed rule (84 FR 7186) for discussion 
of more recent studies regarding context). Therefore, take estimates 
for SURTASS LFA sonar are likely conservative (though we analyze them 
here nonetheless), and takes that do occur will primarily be in the 
form of lower levels of take by Level B harassment.
    (3) Efficacy of the Navy's Three-Part Mitigation Monitoring 
Program--Review of Final Comprehensive and Annual Reports, from August 
2002 through December 2018, indicates that the HF/M3 active sonar 
system has proven to be the most effective of the mitigation monitoring 
measures to detect possible marine mammals in proximity to the 
transmitting LFA sonar array, and use of this system substantially 
increases the probability of detecting marine mammals within the 
mitigation zone (and beyond), providing a superior monitoring 
capability. Because the HF/M3 active sonar is able to monitor marine 
mammals out to an effective range of 2 to 2.5 km (1.2 to 1.5 mi; 1.1 to 
1.3 nmi) from the vessel, it is unlikely that the SURTASS LFA sonar 
operations would expose marine mammals to an SPL greater than 
approximately 174 dB re: 1 [mu]Pa rms. The combination of visual, 
passive acoustic, and active acoustic (HF/M3) monitoring results in 
near 100 percent probability of detection for a medium-sized 
(approximately 33 ft (10 m)) marine mammal swimming towards the system 
before the animal enters the LFA sonar mitigation zone (see Ellison and 
Stein, 2001 and Chapter 5, section 5.4.3 of the 2019 SURTASS LFA FSEIS/
SOEIS for a summary of the effectiveness of the HF/M3 monitoring 
system). Lastly, as noted above, from the commencement of SURTASS LFA 
sonar use in 2002 through the present, neither operation of LFA sonar, 
nor operation of the T-AGOS vessels, has been associated with any mass 
or individual strandings of marine mammals. In addition, required 
monitoring reports indicate that there have been no apparent marine 
mammal avoidance reactions observed, and no observed marine mammal 
exposures to sound levels associated with Level A harassment takes due 
to SURTASS LFA sonar since its use began in 2002.
    In examining the results of the mitigation monitoring procedures 
over the previous 17 years of SURTASS LFA activities, NMFS has 
concluded that the mitigation and monitoring measures for triggering 
shutdowns of the LFA sonar system have been implemented properly and 
have successfully minimized the

[[Page 40206]]

potential adverse effects of SURTASS LFA sonar to marine mammals in the 
LFA sonar mitigation zone around the vessel. This conclusion is further 
supported by documentation that no known mortality or injury to marine 
mammals has occurred over this period.
    For reasons discussed in the Potential Effects of the Specified 
Activity on Marine Mammals and their Habitat section (see the proposed 
rule (84 FR 7186)), NMFS anticipates that the effect of masking will be 
limited and the chances of an LFA sonar sound overlapping whale calls 
at levels that would interfere with their detection and recognition 
will be extremely low. NMFS does not expect any short- or long-term 
effects to marine mammal food resources from SURTASS LFA sonar training 
and testing activities. It is unlikely that the activities of the 
SURTASS LFA sonar vessels transmitting LFA sonar at any place in the 
action area over the course of a year would implicate all of the areas 
for a given species or stock in any year. It is anticipated that ample 
similar nearby habitat areas are available for species/stocks in the 
event that portions of preferred areas are ensonified. Implementation 
of the 2,000-yd LFA sonar mitigation zone (shutdown zone) would ensure 
that most marine mammal takes are limited to lower-level Level B 
harassment. Further, potential impacts in areas of known or likely 
biological importance for functions such as feeding, reproduction, 
etc., effects are mitigated by the coastal standoff zone and OBIAs.
    As noted above, because of the nature, scale, and locations of 
SURTASS LFA sonar training and testing, there is no reason to expect 
meaningfully differential impacts on any particular species or stock 
that warrant additional discussion. However, we include the following 
to ensure understanding of the two cases where the percentages of 
stocks taken are notably higher compared to other stocks. As also noted 
previously, the modeling the Navy uses allows for the enumeration of 
instances of take--each representing an exposure above the Level B 
harassment threshold of a single marine mammal for some amount of time 
(likely relatively short) within a single day. The model does not 
predict how many of these instances for a given species or stock may 
occur as multiple, or repeated, takes to a single individual. Given the 
nature (small number of ships and relatively few hours across two ocean 
basins) and location of the activity (beyond coastal exclusion in open 
ocean, areas where species/stocks are not concentrated as much), as 
well as the relatively small percentages of take compared to abundance 
for most stocks (the vast majority below 10 percent, 12 stocks in the 
10-20 percent range, and a handful ranging from 20-67 percent) and the 
fact that takes of single stocks are expected across multiple regions, 
we expect that most individuals taken are taken only once in a year 
with some small subset taken perhaps a few times in the course of a 
year. However, two stocks have somewhat higher percentages that we note 
here. When estimated instances of take are compared to the estimated 
stock abundances, the percentages are 117 and 321 for the Western North 
Pacific stock of killer whales and the Western North Pacific stock of 
humpback whales, respectively. Acknowledging the uncertainty 
surrounding abundance estimates for the Navy's action area, it is still 
worth noting that these percentages are notably higher than others, and 
would suggest that some number of individuals are expected to be taken 
more than once. It indicates the possibility that some individuals are 
taken several times within a year, as the percentage exceeds 100 
percent. For example, for the Western North Pacific stock of humpback 
whales, the average number of takes would be three or more per 
individual. It is unlikely that takes would be exactly evenly 
distributed across all individuals, and it is therefore more reasonable 
to assume that some number of individuals would be taken fewer than 
three times, while others would be taken on more than three days, and 
we assume up to twice this (i.e., one individual could be taken on six 
days) for the sake of analysis. Even where one individual may be taken 
by Level B harassment (in the form of behavioral disturbance or a small 
degree of TTS) on up to six days within a year, given the nature of the 
activities, there is no reason to expect that these takes would be 
likely to occur on sequential days or that this magnitude of exposure 
within a year would be likely to result in impacts on reproduction or 
survival, especially given the implementation of mitigation to reduce 
the severity of impacts.
    For the following summarized reasons, pulling in the supporting 
information both in this section and previous sections, including 
material not repeated from the proposed rule because it was unchanged, 
NMFS finds that the total authorized taking from SURTASS LFA sonar 
training and testing activities will have a negligible impact on the 
affected species or stocks:
    (1) The small number of SURTASS LFA sonar systems that will be 
operating in the Study Area (likely not in close proximity to one 
another) and the low total number of hours of operation planned across 
all vessels;
    (2) The relatively low duty cycle, short duration of training and 
testing events, and offshore nature of the SURTASS LFA sonar use;
    (3) The fact that marine mammals in unspecified migration corridors 
and open ocean concentrations would be adequately protected from 
exposure to sound levels that would result in injury, most TTS (and any 
accrued would be expected to be of a small degree), and more severe 
levels of behavioral disruption by the historical demonstrated 
effectiveness of the Navy's three-part monitoring program in detecting 
marine mammals and triggering shutdowns;
    (4) Geographic restrictions requiring the SURTASS LFA sonar sound 
field not exceed 180 re: 1 [mu]Pa rms within 22 km of any shoreline, 
including islands, or at a distance of one km from the perimeter of an 
OBIA, as well as limitations on amount of activity near an OBIA absent 
additional approvals through the Navy chain of command, thereby further 
limiting the severity and number of behavioral disturbances in those 
areas; and
    (5) The proven effectiveness of the required three-part monitoring 
and mitigation protocols.
    In summary, based on the analysis contained herein of the likely 
effects of the specified activity on marine mammals and their habitat, 
and taking into consideration the implementation of the proposed 
monitoring and mitigation measures, the authorized takes are not 
expected to adversely affect any species or stock through impacts on 
recruitment or survival. Therefore, NMFS finds that the total 
authorized marine mammal take from the proposed activity will have a 
negligible impact on all affected marine mammal species or stocks.

Subsistence Harvest of Marine Mammals

    The Navy will not operate SURTASS LFA sonar in Arctic waters nor in 
the Gulf of Alaska, or off the Aleutian Island chain where subsistence 
uses of marine mammals protected under the MMPA occur. Therefore, there 
are no relevant subsistence uses of marine mammals implicated by this 
action and there will be no impact on subsistence hunting. SURTASS LFA 
sonar will not cause abandonment of any harvest/hunting locations, 
displace any subsistence users, or place physical barriers between 
marine mammals and hunters. NMFS has determined that the total taking 
affecting species or stocks will not have an unmitigable adverse impact 
on the

[[Page 40207]]

availability of such species or stocks for taking for subsistence 
purposes.

Endangered Species Act

    Eleven marine mammal species under NMFS' jurisdiction with 
confirmed or possible occurrence in the central and western North 
Pacific and eastern Indian Oceans are listed as endangered or 
threatened under the ESA: Blue whale; fin whale; humpback whale 
(Western North Pacific DPS); North Pacific right whale; sei whale; gray 
whale (Western North Pacific DPS); sperm whale; false killer whale 
(Main Hawaiian Islands Insular DPS); Steller sea lion (western DPS); 
spotted seal (Southern DPS); and Hawaiian monk seal. ESA-designated 
critical habitat for Hawaiian monk seals and Main Hawaiian Island 
insular false killer whales is also located in the Study Area. The Navy 
consulted with NMFS pursuant to section 7 of the ESA, and NMFS also 
consulted internally on the issuance of these regulations and LOA under 
section 101(a)(5)(A) of the MMPA for SURTASS LFA sonar training and 
testing activities. NMFS issued a Biological Opinion concluding that 
the issuance of the rule and subsequent LOA is not likely to jeopardize 
the continued existence of the threatened and endangered species under 
NMFS' jurisdiction and is not likely to result in the destruction or 
adverse modification of critical habitat in the SURTASS LFA Study Area. 
The Biological Opinion for this action is available at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.
    The USFWS is responsible for regulating the take of the several 
marine mammal species including the polar bear, walrus, and dugong. The 
Navy has determined that none of these species occur in geographic 
areas that overlap with SURTASS LFA sonar activities and, therefore, 
that SURTASS LFA sonar activities will have no effect on the endangered 
or threatened species or the critical habitat of ESA-listed species 
under the jurisdiction of the USFWS. Thus, no consultation with the 
USFWS pursuant to Section 7 of the ESA occurred.

National Marine Sanctuaries Act

    Under section 304(d) of the National Marine Sanctuaries Act (NMSA), 
federal agencies are required to consult with NOAA's Office of National 
Marine Sanctuaries (ONMS) on activities that are likely to destroy, 
cause the loss of, or injure any sanctuary resource, unless it is 
determined that consultation is not required. Based on NMFS' assessment 
of its action of authorizing incidental take through MMPA regulations 
and an LOA for these Navy activities, NMFS determined that consultation 
under the NMSA is not required.

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 action (i.e., the promulgation of 
regulations and issuance of the LOA) and alternatives with respect to 
potential impacts on the human environment. NMFS participated as a 
cooperating agency on the 2019 SURTASS LFA sonar Final Supplemental 
Environmental Impact Statement/Supplemental Overseas Environmental 
Impact Statement (SURTASS LFA FSEIS/SOEIS) which was published on July 
5, 2019 (84 FR 32168), and is available at https://www.surtass-lfa-eis.com. In accordance with 40 CFR 1506.3, NMFS independently reviewed 
and evaluated the 2019 SURTASS LFA FSEIS/SOEIS and determined that it 
is adequate and sufficient to meet our responsibilities under NEPA for 
the issuance of this rule and associated LOA, and adopted the Navy's 
SURTASS LFA FSEIS/SOEIS. NMFS has prepared a separate Record of 
Decision. NMFS' Record of Decision for adoption of the SURTASS LFA 
FSEIS/SOEIS and issuance of this final rule and subsequent LOAs can be 
found at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.

Classification

    This action does not contain any collection of information 
requirements for purposes of the Paperwork Reduction Act of 1980 (44 
U.S.C. 3501 et seq.).
    The Office of Management and Budget has determined that this final 
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 certified to the Chief 
Counsel for Advocacy of the Small Business Administration at the 
proposed rule stage that this action will not have a significant 
economic impact on a substantial number of small entities. The RFA 
requires a Federal agency 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 will be affected by this rulemaking and 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, will be applicable only to the Navy. NMFS 
does not expect the issuance of these regulations or the associated LOA 
to result in any impacts to small entities pursuant to the RFA. Because 
this action will directly affect the Navy and not a small entity, NMFS 
concludes the action will not result in a significant economic impact 
on a substantial number of small entities. No comments were received 
regarding this certification. As a result, a regulatory flexibility 
analysis is not required and none has been prepared.

Waiver of Delay in Effective Date

    NMFS has determined that there is good cause under the 
Administrative Procedure Act (5 U.S.C. 553(d)(3)) to waive the 30-day 
delay in the effective date of this final rule. No individual or entity 
other than the Navy is affected by the provisions of these regulations. 
The Navy has informed NMFS that it requests that this final rule take 
effect on or by August 13, 2019, so as to not cause a disruption in 
training and testing activities when the NDE expires on August 12, 
2019. The Navy has a compelling national security reason to continue 
military readiness activities without interruption to the SURTASS LFA 
sonar activities. Suspension or interruption of the Navy's ability to 
conduct those activities disrupts adequate and realistic military 
readiness, proper operations, and suitability for combat essential to 
national security. NMFS was unable to accommodate the 30-day delay of 
the effectiveness period due to the need for more time to consider 
additional mitigation measures and finalize NEPA obligations. The 
waiver of the 30-day delay of the effective date of the final rule will 
ensure that the MMPA final rule and LOA are in place by the time the 
NDE expires. Any delay in finalizing the rule would result in either: 
(1) A suspension of planned naval training and testing, which would 
disrupt vital training and testing essential to national security; or 
(2) absent another NDE, the potential for unauthorized takes of marine 
mammals by Navy (should the Navy conduct training and testing without 
an LOA). Moreover, the Navy is ready to implement the rule

[[Page 40208]]

immediately. For these reasons, NMFS finds good cause to waive the 30-
day delay in the effective date. In addition, the rule authorizes 
incidental take of marine mammals that would otherwise be prohibited 
under the statute. Therefore, the rule is granting an exception to the 
Navy and relieving restrictions under the MMPA, which is a separate 
basis for waiving the 30-day effective date for the rule.

List of Subjects in 50 CFR Part 218

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

    Dated: July 31, 2019.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.
    For reasons set forth in the preamble, 50 CFR part 218 is amended 
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:

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


0
2. Add subpart X to read as follows:
Subpart X--Taking and Importing of Marine Mammals; U.S. Navy 
Surveillance Towed Array Sensor System Low Frequency Active (SURTASS 
LFA) Sonar Training and Testing in the Central and Western North 
Pacific and Eastern Indian Oceans
Sec.
218.230 Specified activity, level of taking, and species/stocks.
218.231 Effective dates.
218.232 Permissible methods of taking.
218.233 Prohibitions.
218.234 Mitigation.
218.235 Requirements for monitoring.
218.236 Requirements for reporting.
218.237 Letter of Authorization.
218.238 Renewals and modifications of a Letter of Authorization.

Subpart X--Taking and Importing of Marine Mammals; U.S. Navy 
Surveillance Towed Array Sensor System Low Frequency Active 
(SURTASS LFA) Sonar Training and Testing in the Central and Western 
North Pacific and Eastern Indian Oceans


Sec.  218.230  Specified activity, level of taking, and species/stocks.

    Regulations in this subpart apply to the U.S. Navy (Navy) for the 
taking of marine mammals that occurs incidental to the Navy's SURTASS 
LFA sonar training and testing activities under authority of the 
Secretary of the Navy within the central and western North Pacific and 
eastern Indian Oceans (SURTASS LFA Sonar Study Area) (Table 1 to Sec.  
218.230).

 Table 1 to Sec.   218.230--Species/Stocks Proposed for Authorization by
Level B Harassment for the 7-Year Period of the Proposed Rule by SURTASS
                LFA Sonar Training and Testing Activities
------------------------------------------------------------------------
                Species                             Stock \1\
------------------------------------------------------------------------
Antarctic minke whale..................  ANT.
Blue whale.............................  CNP.
                                         NIND.
                                         WNP.
                                         SIND.
Bryde's whale..........................  ECS.
                                         Hawaii.
                                         WNP.
                                         NIND.
                                         SIND.
Common minke whale.....................  Hawaii.
                                         IND.
                                         WNP JW.
                                         WNP OE.
                                         YS.
Fin whale..............................  ECS.
                                         Hawaii.
                                         IND.
                                         SIND.
                                         WNP.
Humpback whale.........................  CNP stock and Hawaii DPS.
                                         WAU stock and DPS.
                                         WNP stock and DPS.
North Pacific right whale..............  WNP.
Omura's whale..........................  NIND.
                                         SIND.
                                         WNP.
Sei whale..............................  Hawaii.
                                         SIND.
                                         NP.
                                         NIND.
Western North Pacific gray whale.......  WNP stock and Western DPS.
Baird's beaked whale...................  WNP.
Blainville's beaked whale..............  Hawaii.
                                         WNP.
                                         IND.
Common bottlenose dolphin..............  4-Islands.
                                         Hawaii Island.
                                         Hawaii Pelagic.
                                         IA.
                                         IND.
                                         Japanese Coastal.
                                         Kauai/Niihau.

[[Page 40209]]

 
                                         Oahu.
                                         WNP Northern Offshore.
                                         WNP Southern Offshore.
                                         WAU.
Common dolphin.........................  IND.
                                         WNP.
Cuvier's beaked whale..................  Hawaii.
                                         IND.
                                         SH.
                                         WNP.
Dall's porpoise........................  SOJ dalli type.
                                         WNP dalli ecotype.
                                         WNP truei ecotype.
Deraniyagala's beaked whale............  IND.
                                         NP.
Dwarf sperm whale......................  Hawaii.
                                         IND.
                                         WNP.
False killer whale.....................  Hawaii Pelagic.
                                         IA.
                                         IND.
                                         Main Hawaiian Islands Insular
                                          stock and DPS.
                                         Northwestern Hawaiian Islands.
                                         WNP.
Fraser's dolphin.......................  CNP.
                                         Hawaii.
                                         IND.
                                         WNP.
Ginkgo-toothed beaked whale............  IND.
                                         NP.
Harbor porpoise........................  WNP.
Hubbs' beaked whale....................  NP.
Indo-Pacific bottlenose dolphin........  IND.
Killer whale...........................  Hawaii.
                                         IND.
                                         WNP.
Kogia spp..............................  WNP.
Longman's beaked whale.................  Hawaii.
                                         IND.
                                         WNP.
Melon-headed whale.....................  Hawaiian Islands.
                                         IND.
                                         Kohala Resident.
                                         WNP.
Mesoplodon spp.........................  WNP.
Northern right whale dolphin...........  NP.
Pacific white-sided dolphin............  NP.
Pantropical spotted dolphin............  4-Islands.
                                         Hawaii Island.
                                         Hawaiian Pelagic.
                                         IND.
                                         Oahu.
                                         WNP.
Pygmy killer whale.....................  Hawaii.
                                         IND.
                                         WNP.
Pygmy sperm whale......................  Hawaii.
                                         IND.
                                         WNP.
Risso's dolphin........................  Hawaii.
                                         IA.
                                         WNP.
                                         IND.
Rough-toothed dolphin..................  Hawaii.
                                         IND.
                                         WNP.
Short-finned pilot whale...............  Hawaii.
                                         IND.
                                         WNP Northern Ecotype.
                                         WNP Southern Ecotype.
Southern bottlenose whale..............  IND.

[[Page 40210]]

 
Spade-toothed beaked whale.............  IND.
Sperm whale............................  Hawaii.
                                         NIND.
                                         NP.
                                         SIND.
Spinner dolphin........................  Hawaii Island.
                                         Hawaii Pelagic.
                                         IND.
                                         Kauai/Niihau.
                                         Kure/Midway Atoll.
                                         Oahu/4-Islands.
                                         Pearl and Hermes Reef.
                                         WNP.
Stejneger's beaked whale...............  WNP.
Striped dolphin........................  Hawaii.
                                         IND.
                                         Japanese Coastal.
                                         WNP Northern Offshore.
                                         WNP Southern Offshore.
Hawaiian monk seal.....................  Hawaii.
Northern fur seal......................  Western Pacific.
Ribbon seal............................  NP.
Spotted seal...........................  Alaska stock/Bering Sea DPS.
                                         Southern stock and DPS.
Steller sea lion.......................  Western/Asian stock and Western
                                          DPS.
------------------------------------------------------------------------
\1\ ANT = Antarctic; CNP = Central North Pacific; NP = North Pacific;
  NIND = Northern Indian; SIND = Southern Indian; IND = Indian; WNP =
  Western North Pacific; ECS = East China Sea; WP = Western Pacific; SOJ
  = Sea of Japan; IA = Inshore Archipelago; WAU = Western Australia; YS
  = Yellow Sea; OE = Offshore Japan; OW = Nearshore Japan; JW = Sea of
  Japan/Minke; JE = Pacific coast of Japan; SH = Southern Hemisphere;
  DPS = distinct population segment.

Sec.  218.231  Effective dates.

    Regulations in this subpart are effective from August 13, 2019, 
through August 12, 2026.


Sec.  218.232  Permissible methods of taking.

    Under a Letter or Letters of Authorization (LOA) issued pursuant to 
Sec. Sec.  216.106 of this chapter and 218.237, the Holder of the LOA 
(hereinafter ``Navy'') may incidentally, but not intentionally, take 
marine mammals within the area described in Sec.  218.230 by Level B 
harassment associated with SURTASS LFA sonar training and testing 
provided the activity is in compliance with all terms, conditions, and 
requirements of the regulations in this subpart and the applicable LOA.


Sec.  218.233  Prohibitions.

    Notwithstanding takings contemplated in Sec.  218.230 and 
authorized by a LOA issued under Sec. Sec.  216.106 of this chapter and 
218.237, no person in connection with the activities described in Sec.  
218.230 may:
    (a) Violate, or fail to comply with, the terms, conditions, and 
requirements of this subpart or a LOA issued under Sec. Sec.  216.106 
of this chapter and 218.237;
    (b) Take any marine mammal not specified in such LOAs;
    (c) Take any marine mammal specified in such LOAs in any manner 
other than Level B harassment;
    (d) Take any marine mammal specified in the LOA if NMFS makes a 
determination that such taking is having, or may have, more than a 
negligible impact on the species or stocks concerned; or
    (e) Take a marine mammal specified in the LOA if NMFS determines 
such taking is having, or may have, an unmitigable adverse impact on 
availability of the species or stock for taking for subsistence uses.


Sec.  218.234  Mitigation.

    When conducting activities identified in Sec.  218.230, the 
mitigation measures described in this section and in any LOA issued 
under Sec. Sec.  216.106 of this chapter and 218.237 must be 
implemented.
    (a) Personnel training--lookouts. The Navy will utilize one or more 
trained marine biologists qualified in conducting at-sea marine mammal 
visual monitoring to conduct at-sea marine mammal visual monitoring 
training and qualify designated ship personnel to conduct at-sea visual 
monitoring. Training will ensure quick and effective communication 
within the command structure in order to facilitate implementation of 
protective measures if they detect marine mammals and may be 
accomplished either in-person, or via video training.
    (b) General operating procedures. (1) Prior to SURTASS LFA sonar 
activities, the Navy will promulgate executive guidance for the 
administration, execution, and compliance with the environmental 
regulations under these regulations and LOA.
    (2) The Navy must not transmit the SURTASS LFA sonar signal at a 
frequency greater than 500 Hz.
    (c) 2,000-yard LFA sonar mitigation zone; suspension and delay. If 
a marine mammal is detected, through monitoring required under Sec.  
218.235, within or about to enter within 2,000 yards of the SURTASS LFA 
source (i.e., the LFA mitigation zone), the Navy must immediately delay 
or suspend SURTASS LFA sonar transmissions.
    (d) Resumption of SURTASS LFA sonar transmissions. (1) The Holder 
of a LOA may not resume SURTASS LFA sonar transmissions earlier than 15 
minutes after:
    (i) All marine mammals have left the area of the 2,000-yard LFA 
sonar mitigation zone; and
    (ii) There is no further detection of any marine mammal within the 
2,000-yard LFA sonar mitigation zone as determined by the visual, 
passive acoustic, and active acoustic high frequency monitoring 
described in Sec.  218.235.
    (2) [Reserved]

[[Page 40211]]

    (e) Ramp-up procedures for the high-frequency marine mammal 
monitoring (HF/M3) sonar required under Sec.  218.235. (1) The Navy 
must ramp up the HF/M3 sonar power level beginning at a maximum source 
sound pressure level of 180 dB: re 1 [mu]Pa at 1 meter in 10-dB 
increments to operating levels over a period of no less than five 
minutes:
    (i) At least 30 minutes prior to any SURTASS LFA sonar 
transmissions; and
    (ii) Anytime after the HF/M3 source has been powered down for more 
than two minutes.
    (2) The Navy must not increase the HF/M3 sound pressure level once 
a marine mammal is detected; ramp-up may resume once marine mammals are 
no longer detected.
    (f) Geographic restrictions on the SURTASS LFA sonar sound field. 
(1) LFA sonar training and testing activities must be conducted such 
that:
    (i) The received level of SURTASS LFA sonar transmissions will not 
exceed 180 dB re: 1 [mu]Pa rms within 22 km (12 nmi) from any emergent 
land, including offshore islands;
    (ii) The received level of SURTASS LFA sonar transmissions will not 
exceed 180 dB re: 1 [mu]Pa rms at a distance of 1 km (0.5 nmi) seaward 
of the outer perimeter of any Offshore Biologically Important Area 
(OBIA) designated in the Study Area for SURTASS LFA sonar in paragraph 
(f)(2) of this section, or subsequently identified through the Adaptive 
Management process specified in Sec.  218.241, during the period 
specified. The boundaries and periods of such OBIAs will be kept on 
file in NMFS' Office of Protected Resources and on its website at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities.
    (iii) No more than 25 percent of the authorized amount 
(transmission hours) of SURTASS LFA sonar for training and testing will 
be conducted within 10 nmi (18.5 km) of any single OBIA during any year 
(no more than 124 hours in years 1-4 and 148 hours in years 5-7) unless 
the following conditions are met: Should national security present a 
requirement to conduct more than 25 percent of authorized hours of 
SURTASS LFA sonar within 10 nmi (18.5 km) of any single OBIA during any 
year, naval units will obtain permission from the appropriate 
designated Command authority prior to commencement of the activity. The 
Navy will provide NMFS with notification as soon as is practicable and 
include the information (e.g., sonar hours) in its annual activity 
reports submitted to NMFS.
    (iv) No activities with the SURTASS LFA system will occur within 
territorial seas of foreign nations, which are areas from 0 up to 12 
nmi from shore, depending on the distance that individual nations 
claim; and
    (v) No activities with the SURTASS LFA sonar system will occur in 
the waters of Penguin Bank, Hawaii (defined as water depth of 600 ft 
(183 m)), and ensonification of Hawaii state waters (out to 3 nmi) will 
not exceed 145 dB re: 1 [mu]Pa rms.
    (2) Offshore Biologically Important Areas (OBIAs) for marine 
mammals (with specified periods) for SURTASS LFA sonar training and 
testing activities include the following (Table 1 to paragraph (f)(2)):

                   Table 1 to Paragraph (f)(2)--Offshore Biologically Important Areas (OBIAs)
----------------------------------------------------------------------------------------------------------------
              OBIA name                          Ocean area                    Effective seasonal period
----------------------------------------------------------------------------------------------------------------
Main Hawaiian Islands................  Central North Pacific........  November to April.
Northwestern Hawaiian Islands........  Central North Pacific........  December to April.
Mariana Islands......................  Western North Pacific........  February to April.
Ryukyu[hyphen]Philippines............  Western North Pacific........  January to April.
Ogasawara Islands (Sperm Whale)......  Western North Pacific........  June to September.
Ogasawara[hyphen]Kazin Islands         Western North Pacific........  December to May.
 (Humpback Whale).
Honshu...............................  Western North Pacific........  January to May.
Southeast Kamchatka..................  Western North Pacific........  June to September.
Gulf of Thailand.....................  Eastern Indian Ocean.........  April to November.
Western Australia (Blue Whale).......  Eastern Indian Ocean.........  May to November.
Western Australia (Humpback Whale)...  Eastern Indian Ocean.........  May to December.
Southern Bali........................  Eastern Indian Ocean.........  October to November.
Swatch-of-No-Ground (SoNG)...........  Northern Bay of Bengal.......  Year-round.
Sri Lanka............................  Eastern Indian Ocean.........  October to April.
----------------------------------------------------------------------------------------------------------------

    (g) Minimization of additional harm to live-stranded (or milling) 
mammals. The Navy must consult the Notification and Reporting Plan, 
which sets out the requirements for when live stranded marine mammals 
are reported in the Study Area. The Stranding and Notification Plan is 
available at: https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navy-operations-surveillance-towed-array-sensor-system-0.


Sec.  218.235  Requirements for monitoring.

    (a) The Navy must:
    (1) Conduct visual monitoring from the ship's bridge during all 
daylight hours (30 minutes before sunrise until 30 minutes after 
sunset). During training and testing activities that employ SURTASS LFA 
sonar in the active mode, the SURTASS vessels must have Lookouts to 
maintain a topside watch with standard binoculars (7x) and with the 
naked eye. If the lookout sights a possible marine mammal, the lookout 
will use big-eye binoculars (25x) to confirm the sighting and 
potentially identify the marine mammal species.
    (2) Use the passive SURTASS sonar component to detect vocalizing 
marine mammals; and
    (3) Use the HF/M3 sonar to locate and track marine mammals in 
relation to the SURTASS LFA sonar vessel and the LFA mitigation zone, 
subject to the ramp-up requirements in Sec.  216.234(e) of this 
chapter.
    (b) Monitoring under paragraph (a) of this section must:
    (1) Commence at least 30 minutes before the first SURTASS LFA sonar 
training and testing transmission;
    (2) Continue between transmission pings; and
    (3) Continue either for at least 15 minutes after completion of the 
SURTASS LFA sonar training and testing transmission, or, if marine 
mammals are exhibiting unusual changes in behavioral patterns, until 
behavior patterns return to normal or conditions prevent continued 
observations.

[[Page 40212]]

    (c) The Navy must designate qualified on-site individuals to 
conduct the mitigation, monitoring, and reporting activities specified 
in these regulations and LOA issued under Sec. Sec.  216.106 of this 
chapter and 218.237.
    (d) The Navy must continue to assess data from the Marine Mammal 
Monitoring Program and work toward making some portion of that data, 
after appropriate security reviews, available to scientists with 
appropriate clearances. Any portions of the analyses conducted by these 
scientists based on these data that are determined to be unclassified 
after appropriate security reviews will be made publically available.
    (e) The Navy must collect ambient noise data and will explore the 
feasibility of declassifying and archiving the ambient noise data for 
incorporation into appropriate ocean noise budget efforts.
    (f) The Navy must conduct all monitoring required under LOAs.


Sec.  218.236  Requirements for reporting.

    (a) The Navy must submit classified and unclassified annual 
training and testing activity reports to the Director, Office of 
Protected Resources, NMFS, no later than 90 days after the end of each 
year covered by the LOA beginning on the date of effectiveness of a 
LOA. Each annual training and testing activity report will include a 
summary of all active-mode training and testing activities completed 
during that year. At a minimum, each classified training and testing 
activity report must contain the following information:
    (1) Dates, times, and location of each vessel during each training 
and testing activity;
    (2) Information on sonar transmissions during each training and 
testing activity;
    (3) Results of the marine mammal monitoring program specified in 
the LOA; and
    (4) Estimates of the percentages of marine mammal species and 
stocks affected (both for the year and cumulatively for each successive 
year) covered by the LOA.
    (b) The seventh annual report must be prepared as a final 
comprehensive report, which will include information for the final year 
as well as the prior six years of activities under the rule. This final 
comprehensive report must also contain an unclassified analysis of new 
passive sonar technologies and an assessment of whether such a system 
is feasible as an alternative to SURTASS LFA sonar, and be submitted to 
the Director, Office of Protected Resources, NMFS as described in this 
paragraph (b).
    (c) The Navy will continue to assess the data collected by its 
undersea arrays and work toward making some portion of that data, after 
appropriate security reviews, available to scientists with appropriate 
clearances. Any portions of the analyses conducted by these scientists 
based on these data that are determined to be unclassified after 
appropriate security reviews will be made publically available.
    (d) The Navy must consult the Notification and Reporting Plan, 
which sets out notification, reporting, and other requirements for when 
dead, injured, or live stranded marine mammals are reported in the 
Study Area. The Stranding and Notification Plan is available at: 
https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navy-operations-surveillance-towed-array-sensor-system-0.


Sec.  218.237  Letter of Authorization.

    (a) To incidentally take marine mammals pursuant to these 
regulations, Navy must apply for and obtain a Letter of Authorization 
(LOA).
    (b) An LOA, unless suspended or revoked, may be effective for a 
period of time not to exceed the expiration date of these regulations.
    (c) If an LOA expires prior to the expiration date of these 
regulations, Navy may apply for and obtain a renewal of the LOA.
    (d) In the event of projected changes to the activity or to 
mitigation and monitoring measures required by an LOA (excluding 
changes made pursuant to the adaptive management provision of Sec.  
218.239), the Navy must apply for and obtain a modification of the LOA 
as described in Sec.  218.238.
    (e) The LOA shall set forth:
    (1) Permissible methods of incidental taking;
    (2) Means of effecting the least practicable adverse impact on the 
species, its habitat, and on the availability of the species for 
subsistence uses (i.e., mitigation); and
    (3) Requirements for monitoring and reporting.
    (f) Issuance of the LOA will be based on a determination that the 
level of taking will be consistent with the findings made for the total 
taking allowable under these regulations.
    (g) Notice of issuance or denial of an LOA will be published in the 
Federal Register within thirty days of a determination.


Sec.  218.238  Renewals and modifications of a Letter of Authorization.

    (a) An LOA issued under Sec. Sec.  216.106 of this chapter and 
218.237 for the activity identified in Sec.  [thinsp]218.230 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 Navy 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 that do not result in 
more than a minor change in the total estimated number of takes (or 
distribution by species or stock or years), NMFS may publish 
notification of a 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.  [thinsp]216.106 of this chapter 
and 218.237 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

[[Page 40213]]

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.  
[thinsp]216.106 of this chapter and 218.237, an LOA may be modified 
without prior notice or opportunity for public comment. Notice would be 
published in the Federal Register within thirty days of the action.

[FR Doc. 2019-16695 Filed 8-12-19; 8:45 am]
 BILLING CODE 3510-22-P