Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Office of Naval Research's Arctic Research Activities in the Beaufort and Chukchi Seas (Year 7), 77089-77102 [2024-21561]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 89, Number 183 (Friday, September 20, 2024)]
[Notices]
[Pages 77089-77102]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-21561]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XE202]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Office of Naval Research's 
Arctic Research Activities in the Beaufort and Chukchi Seas (Year 7)

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

ACTION: Notice; issuance of an incidental harassment authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued an incidental harassment authorization (IHA) to 
the Office of Naval Research (ONR) to incidentally harass marine 
mammals during Arctic Research Activities (ARA) in the Beaufort Sea and 
eastern Chukchi Sea. The ONR's activities are considered military 
readiness activities pursuant to the MMPA, as amended by the National 
Defense Authorization Act for Fiscal Year 2004 (2004 NDAA).

DATES: This authorization is effective from September 14, 2024, through 
September 13, 2025.

ADDRESSES: Electronic copies of the application and supporting 
documents, as well as a list of the references cited in this document, 
may be obtained online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities. In case of problems accessing

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these documents, please call the contact listed below.

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

SUPPLEMENTARY INFORMATION:

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 proposed or, if the taking is limited to harassment, a notice of a 
proposed IHA is provided to the public for review.
    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 the species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the monitoring and 
reporting of the takings. The definitions of all applicable MMPA 
statutory terms cited above are included in the relevant sections 
below.
    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 applied to a ``military 
readiness activity.'' The activity for which incidental take of marine 
mammals is being requested qualifies as a military readiness activity.

Summary of Request

    On March 29, 2024, NMFS received a request from the ONR for an IHA 
to take marine mammals incidental to ARA in the Beaufort and Chukchi 
Seas. Following NMFS' review of the application, the ONR submitted a 
revised version on July 23, 2024. The application was deemed adequate 
and complete on August 5, 2024. The ONR's request is for take of beluga 
whales and ringed seals by Level B harassment only. Neither the ONR nor 
NMFS expect serious injury or mortality to result from this activity 
and, therefore, an IHA is appropriate.
    This IHA will cover the seventh year of a larger project for which 
ONR obtained prior IHAs and renewal IHAs (83 FR 48799, September 27, 
2018; 84 FR 50007, September 24, 2019; 85 FR 53333, August 28, 2020; 86 
FR 54931, October 5, 2021; 87 FR 57458, September 20, 2022; 88 FR 
65657, September 18, 2023). ONR has complied with all the requirements 
(e.g., mitigation, monitoring, and reporting) of the previous IHAs. 
There are no changes from the proposed IHA to the final IHA.

Description of the Specified Activity

Overview

    The ONR plans to conduct scientific experiments in support of ARA 
using active acoustic sources within the Beaufort and Chukchi Seas. 
Project activities involve acoustic testing and a multi-frequency 
navigation system concept test using left-behind active acoustic 
sources. The planned experiments involve the deployment of moored, 
drifting, and ice-tethered active acoustic sources from the Research 
Vessel (R/V) Sikuliaq. Recovery of equipment may be from R/V Sikuliaq, 
U.S. Coast Guard Cutter (CGC) HEALY, or another vessel, and icebreaking 
may be required. Underwater sound from the active acoustic sources and 
noise from icebreaking may result in Level B harassment of marine 
mammals.

Dates and Duration

    The planned action will occur from September 2024 through September 
2025 and include up to two research cruises. Acoustic testing will take 
place during the cruises, with the first cruise beginning September 
2024, and a potential second cruise occurring in summer or fall 2025, 
which may include up to 8 days of icebreaking activities.

Geographic Region

    The planned action will occur across the U.S. Exclusive Economic 
Zone (EEZ) in the Beaufort and Chukchi Seas, partially in the high seas 
north of Alaska, the Global Commons, and within a part of the Canadian 
EEZ (in which the appropriate permits will be obtained by the Navy) 
(figure 1). The planned action will primarily occur in the Beaufort Sea 
but the analysis considers the drifting of active sources on buoys into 
the eastern portion of the Chukchi Sea. The closest point of the study 
area to the Alaska coast is 204 kilometers (km; 110 nautical miles 
(nmi)). The study area is approximately 639,267 square kilometers 
(km\2\).
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[GRAPHIC] [TIFF OMITTED] TN20SE24.006

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Detailed Description of the Specified Activity

    A detailed description of the planned ARA is provided in the 
Federal Register notice for the proposed IHA (89 FR 66068, August 14, 
2024). Since that time, no changes have been made to the planned 
activities. Therefore, a detailed description is not provided here. 
Please refer to that Federal Register notice for the description of the 
specific activity.
    Planned mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Mitigation and 
Monitoring and Reporting).

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to ONR was published in 
the Federal Register on August 14, 2024 (89 FR 66068). That notice 
described, in

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detail, ONR's activity, the marine mammal species that may be affected 
by the activity, and the anticipated effects on marine mammals. In that 
notice, we requested public input on the request for authorization 
described therein, our analyses, the proposed authorization, and any 
other aspect of the notice of proposed IHA, and requested that 
interested persons submit relevant information, suggestions, and 
comments. This proposed notice was available for a 30-day public 
comment period.
    In total, NMFS received two comments from one private citizen and 
from a state government department (Alaska Department of Fish and 
Game). One comment was out-of-scope or not applicable to the project 
and is not described herein or discussed further. We do not 
specifically address comments expressing general opposition to military 
readiness activities or respond to comments that are out of scope of 
the proposed IHA (89 FR 66068, August 14, 2024).
    All comments received during the public comment period which 
contained relevant points were considered by NMFS and are described and 
responded to below. All relevant comment letters are available on NMFS' 
website (https://www.fisheries.noaa.gov/action/incidental-take-authorization-office-naval-researchs-arctic-research-activities-year-7).
    Comment: A commenter expressed concern that bowhead whales were not 
included as a potential species in the area and provided a publication 
by George and Thewissen (2020), specifically referencing a satellite 
telemetry study where multiple bowhead whales were detected north of 75 
degrees N during the months of July, September, and October. The 
commenter indicated that the mitigation measures in the proposed IHA 
(89 FR 66068, August 14, 2024) would minimize disturbance to bowhead 
whales, but that the proposal should have discussed bowhead whales in 
more detail.
    Response: NMFS refers the commenter to the Description of Marine 
Mammals in the Area of Specified Activities section of the proposed IHA 
(89 FR 66068, August 14, 2024), which indicates bowhead whales are 
expected in the ARA Study Area during the planned action and were 
considered in the applicant's quantitative modeling of potential 
effects of acoustic sources on marine mammals expected within the study 
area. The modeling resulted in no calculated exposures for the bowhead 
whale due to either active acoustic sources or icebreaking and, as no 
harassment of the bowhead whale is expected, the species was not 
discussed further.
    In addition to the references used by the applicant in their 
request for an IHA, the Overseas Environmental Assessment for Office of 
Naval Research Arctic Research Activities in the Beaufort and Chukchi 
Seas 2022-2025, provided on the project website (https://www.fisheries.noaa.gov/action/incidental-take-authorization-office-naval-researchs-arctic-research-activities-year-7), includes 
information on the distribution of bowhead whales, specifically that 
their range can expand and contract beyond 75 degrees N depending on 
ice cover and access to Arctic straits (Rugh et al., 2003),'' which is 
in agreement with the information provided by the commenter. 
Importantly, the commenter does not suggest that incidental take of 
bowhead whales is likely, and following review of the comments and 
cited information NMFS has determined that no new information is 
presented and that the commenter's evaluation is consistent with NMFS'. 
No changes have been made as a result of this comment.

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions, instead of reprinting the information. Additional 
information regarding population trends and threats may be found in 
NMFS' Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and 
more general information about these species (e.g., physical and 
behavioral descriptions) may be found on NMFS' website (https://www.fisheries.noaa.gov/find-species).
    Table 1 lists all species or stocks for which take is expected and 
authorized for this activity and summarizes information related to the 
population or stock, including regulatory status under the MMPA and 
Endangered Species Act (ESA) and potential biological removal (PBR), 
where known. PBR is defined by the MMPA as the maximum number of 
animals, not including natural mortalities, that may be removed from a 
marine mammal stock while allowing that stock to reach or maintain its 
optimum sustainable population (as described in NMFS' SARs). While no 
serious injury or mortality is anticipated or authorized here, PBR and 
annual serious injury and mortality (M/SI) from anthropogenic sources 
are included here as gross indicators of the status of the species or 
stocks and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS' U.S. Alaska SARs (Young et al., 2023). All values presented in 
table 1 are the most recent available at the time of publication and 
are available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

                                            Table 1--Species Likely Impacted by the Specified Activities \1\
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                                                                                         ESA/ MMPA status;   Stock abundance (CV,
             Common name                  Scientific name               Stock             strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \2\          abundance survey) \3\               SI \4\
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Beluga Whale........................  Delphinapterus leucas..  Beaufort Sea...........  -, -, N             39,258 (0.229, N/A,           UND        104
                                                                                                             1992).
Beluga Whale........................  Delphinapterus leucas..  Eastern Chukchi........  -, -, N             13,305 (0.51, 8,875,          178         56
                                                                                                             2017).
Ringed Seal.........................  Pusa hispida...........  Arctic.................  T, D, Y             UND \5\ (UND, UND,            UND      6,459
                                                                                                             2013).
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\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
  (https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/).

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\2\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
  designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or
  which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
  automatically designated under the MMPA as depleted and as a strategic stock.
\3\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, vessel strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A
  CV associated with estimated mortality due to commercial fisheries is presented in some cases.
\5\ A reliable population estimate for the entire stock is not available. Using a sub-sample of data collected from the U.S. portion of the Bering Sea,
  an abundance estimate of 171,418 ringed seals has been calculated, but this estimate does not account for availability bias due to seals in the water
  or in the shore-fast ice zone at the time of the survey. The actual number of ringed seals in the U.S. portion of the Bering Sea is likely much
  higher. Using the Nmin based upon this negatively biased population estimate, the PBR is calculated to be 4,755 seals, although this is also a
  negatively biased estimate.

    As indicated above, both species (with three managed stocks) in 
table 1 temporally and spatially co-occur with the activity to the 
degree that take is reasonably likely to occur. While bowhead whales 
(Balaena mysticetus), gray whales (Eschrichtius robustus), bearded 
seals (Erignathus barbatus), spotted seals (Phoca largha), and ribbon 
seals (Histriophoca fasciata) have been documented in the area, the 
temporal and/or spatial occurrence of these species is such that take 
is not expected to occur, and they are not discussed further.
    A detailed description of the species likely to be affected by the 
ARA, including brief introductions to the species and relevant stocks 
as well as available information regarding population trends and 
threats, and information regarding local occurrence, were provided in 
the Federal Register notice for the proposed IHA (89 FR 66068, August 
14, 2024); since that time, we are not aware of any changes in the 
status of these species and stocks; therefore, detailed descriptions 
are not provided here. Please refer to that Federal Register notice for 
these descriptions. Please also refer to NMFS' website (https://www.fisheries.noaa.gov/find-species) for generalized species accounts.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Not all marine mammal species have equal 
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and 
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al. 
(2007) and Southall et al. (2019) recommended that marine mammals be 
divided into hearing groups based on directly measured (behavioral or 
auditory evoked potential techniques) or estimated hearing ranges 
(behavioral response data, anatomical modeling, etc.). Subsequently, 
NMFS (2018) described generalized hearing ranges for these marine 
mammal hearing groups. Generalized hearing ranges were chosen based on 
the approximately 65 decibel (dB) threshold from the normalized 
composite audiograms, with the exception for lower limits for low-
frequency cetaceans where the lower bound was deemed to be biologically 
implausible and the lower bound from Southall et al. (2007) retained. 
Marine mammal hearing groups and their associated hearing ranges are 
provided in table 2.

                  Table 2--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
               Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen         7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans (dolphins,      150 Hz to 160 kHz.
 toothed whales, beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans (true          275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 Cephalorhynchid, Lagenorhynchus cruciger &
 L. australis).
Phocid pinnipeds (PW) (underwater) (true     50 Hz to 86 kHz.
 seals).
Otariid pinnipeds (OW) (underwater) (sea     60 Hz to 39 kHz.
 lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on approximately 65 dB threshold from
  normalized composite audiogram, with the exception for lower limits
  for LF cetaceans (Southall et al., 2007) and PW pinniped
  (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth et al., 
2013). This division between phocid and otariid pinnipeds is now 
reflected in the updated hearing groups proposed in Southall et al. 
(2019).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from ONR's ARA have the potential 
to result in behavioral harassment of marine mammals in the vicinity of 
the study area. The notice of proposed IHA (89 FR 66068, August 14, 
2024) included a discussion of the effects of anthropogenic noise on 
marine mammals and the potential effects of underwater noise from ONR's 
ARA on marine mammals and their habitat. That information and analysis 
is referenced in this final IHA determination and is not repeated here; 
please refer to the notice of proposed IHA (89 FR 66068, August 14, 
2024).

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
authorized through the IHA, which will inform NMFS' consideration of 
the negligible impact determinations and impacts on subsistence uses.
    Harassment is the only type of take expected to result from these 
activities. For this military readiness activity, 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

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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 the behavioral patterns are 
abandoned or significantly altered (Level B harassment).
    Authorized takes will be by Level B harassment only, in the form of 
direct behavioral disturbances and/or temporary threshold shift (TTS) 
for individual marine mammals resulting from exposure to active 
acoustic transmissions and icebreaking. Based on the nature of the 
activity, Level A harassment is neither anticipated nor authorized.
    As described previously, no serious injury or mortality is 
anticipated or authorized for this activity. Below we describe how the 
authorized take numbers are estimated.
    For acoustic impacts, generally speaking, we estimate take by 
considering: (1) acoustic thresholds above which NMFS believes the best 
available science indicates marine mammals will be behaviorally 
harassed or incur some degree of permanent hearing impairment; (2) the 
area or volume of water that will be ensonified above these levels in a 
day; (3) the density or occurrence of marine mammals within these 
ensonified areas; and, (4) the number of days of activities. We note 
that while these factors can contribute to a basic calculation to 
provide an initial prediction of potential takes, additional 
information that can qualitatively inform take estimates is also 
sometimes available (e.g., previous monitoring results or average group 
size). Below, we describe the factors considered here in more detail 
and present the authorized take estimates.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur permanent threshold shift (PTS) of some 
degree (equated to Level A harassment). Thresholds have also been 
developed identifying the received level of in-air sound above which 
exposed pinnipeds would likely be behaviorally harassed.
Level B Harassment
    Though significantly driven by received level, the onset of 
behavioral disturbance from anthropogenic noise exposure is also 
informed to varying degrees by other factors related to the source or 
exposure context (e.g., frequency, predictability, duty cycle, duration 
of the exposure, signal-to-noise ratio, distance to the source), the 
environment (e.g., bathymetry, other noises in the area, predators in 
the area), and the receiving animals (hearing, motivation, experience, 
demography, life stage, depth) and can be difficult to predict (e.g., 
Southall et al., 2007; Southall et al., 2021; Ellison et al., 2012). 
Based on what the available science indicates and the practical need to 
use a threshold based on a metric that is both predictable and 
measurable for most activities, NMFS typically uses a generalized 
acoustic threshold based on received level to estimate the onset of 
behavioral harassment. NMFS generally predicts that marine mammals are 
likely to be behaviorally harassed in a manner considered to be Level B 
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced 
to 1 microPascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile 
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g., 
scientific sonar) sources. Generally speaking, Level B harassment 
estimates based on these behavioral harassment thresholds are expected 
to include any likely takes by TTS as, in most cases, the likelihood of 
TTS occurs at distances from the source less than those at which 
behavioral harassment is likely. TTS of a sufficient degree can 
manifest as behavioral harassment, as reduced hearing sensitivity and 
the potential reduced opportunities to detect important signals 
(conspecific communication, predators, prey) may result in changes in 
behavior patterns that would not otherwise occur.
    In this case, NMFS is proposing to adopt the ONR's approach to 
estimating incidental take by Level B harassment from the active 
acoustic sources for this action, which includes use of dose response 
functions. The ONR's dose response functions were developed to estimate 
take from sonar and similar transducers, but are not applicable to 
icebreaking. Multi-year research efforts have conducted sonar exposure 
studies for odontocetes and mysticetes (Miller et al., 2012; Sivle et 
al., 2012). Several studies with captive animals have provided data 
under controlled circumstances for odontocetes and pinnipeds (Houser et 
al., 2013b; Houser et al., 2013a). Moretti et al. (2014) published a 
beaked whale dose-response curve based on passive acoustic monitoring 
of beaked whales during U.S. Navy training activity at Atlantic 
Underwater Test and Evaluation Center during actual anti-submarine 
warfare exercises.
    Southall et al. (2007), and more recently (Southall et al., 2019), 
synthesized data from many past behavioral studies and observations to 
determine the likelihood of behavioral reactions at specific sound 
levels. While in general, the louder the sound source the more intense 
the behavioral response, it was clear that the proximity of a sound 
source and the animal's experience, motivation, and conditioning were 
also critical factors influencing the response (Southall et al., 2007; 
Southall et al., 2019). After examining all of the available data, the 
authors felt that the derivation of thresholds for behavioral response 
based solely on exposure level was not supported because context of the 
animal at the time of sound exposure was an important factor in 
estimating response. Nonetheless, in some conditions, consistent 
avoidance reactions were noted at higher sound levels depending on the 
marine mammal species or group allowing conclusions to be drawn. Phocid 
seals showed avoidance reactions at or below 190 dB re 1 [mu]Pa at 1 m; 
thus, seals may actually receive levels adequate to produce TTS before 
avoiding the source.
    Odontocete behavioral criteria for non-impulsive sources are based 
on controlled exposure studies for dolphins and sea mammals, sonar, and 
safety (3S) studies where odontocete behavioral responses were reported 
after exposure to sonar (Miller et al., 2011; Miller et al., 2012; 
Antunes et al., 2014; Miller et al., 2014; Houser et al., 2013b). For 
the 3S study, the sonar outputs included 1-2 kilohertz (kHz) up- and 
down-sweeps and 6-7 kHz up-sweeps; source levels were ramped up from 
152-158 dB re 1 [mu]Pa to a maximum of 198-214 re 1 [mu]Pa at 1 m. 
Sonar signals were ramped up over several pings while the vessel 
approached the mammals. The study did include some control passes of 
vessels with the sonar off to discern the behavioral responses of the 
mammals to vessel presence alone versus active sonar.
    The controlled exposure studies included exposing the Navy's 
trained bottlenose dolphins to mid-frequency sonar while they were in a 
pen. Mid-frequency sonar was played at six different exposure levels 
from 125-185 dB re 1 [mu]Pa (RMS). The behavioral response function for 
odontocetes resulting from the studies described above has a 50 percent 
probability of response at 157 dB re 1 [mu]Pa. Additionally, distance 
cutoffs (20 km for

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MF cetaceans) were applied to exclude exposures beyond which the 
potential of significant behavioral responses is considered to be 
unlikely.
    The pinniped behavioral threshold are based on controlled exposure 
experiments on the following captive animals: hooded seal (Cystophora 
cristata), gray seal (Halichoerus grypus), and California sea lion 
(G[ouml]tz et al., 2010; Houser et al., 2013a; Kvadsheim et al., 2010). 
Hooded seals were exposed to increasing levels of sonar until an 
avoidance response was observed, while the grey seals were exposed 
first to a single received level multiple times, then an increasing 
received level. Each individual California sea lion was exposed to the 
same received level ten times. These exposure sessions were combined 
into a single response value, with an overall response assumed if an 
animal responded in any single session. The resulting behavioral 
response function for pinnipeds has a 50 percent probability of 
response at 166 dB re 1 [mu]Pa. Additionally, distance cutoffs (10 km 
for pinnipeds) were applied to exclude exposures beyond which the 
potential of significant behavioral responses is considered unlikely. 
For additional information regarding marine mammal thresholds for PTS 
and TTS onset, please see NMFS (2018) and table 4.
    Empirical evidence has not shown responses to non-impulsive 
acoustic sources that will constitute take beyond a few km from a non-
impulsive acoustic source, which is why NMFS and the Navy 
conservatively set distance cutoffs for pinnipeds and mid-frequency 
cetaceans (U.S. Department of the Navy, 2017a). The cutoff distances 
for fixed sources are different from those for moving sources, as they 
are treated as individual sources in ONR's modeling given that the 
distance between them is significantly greater than the range to which 
environmental effects can occur. Fixed source cutoff distances used 
were 5 km (2.7 nmi) for pinnipeds and 10 km (5.4 nmi) for beluga whales 
(table 3). As some of the on-site drifting sources could come closer 
together, the drifting source cutoffs applied were 10 km (5.4 nmi) for 
pinnipeds and 20 km (10.8 nmi) for beluga whales (table 3). Regardless 
of the received level at that distance, take is not estimated to occur 
beyond these cutoff distances. Range to thresholds were calculated for 
the noise associated with icebreaking in the study area. These all fall 
within the same cutoff distances as non-impulsive active acoustic 
sources; range to behavioral threshold for both beluga whales and 
ringed seal were under 5 km (2.7 nmi), and range to TTS threshold for 
both under 15 m (49.2 ft) (table 3).

                         Table 3--Cutoff Distances and Acoustic Thresholds Identifying the Onset of Behavioral Disturbance, TTS, and PTS for Non-Impulsive Sound Sources
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Fixed source       Drifting source       Behavioral      Icebreaking source      Behavioral
                                                          behavioral          behavioral        criteria: non-        behavioral           criteria:         Physiological       Physiological
          Hearing group                 Species        threshold cutoff    threshold cutoff   impulsive acoustic   threshold cutoff       icebreaking       criteria: onset     criteria: onset
                                                         distance \a\        distance \a\           sources        distance \a\ \b\         sources               TTS                 PTS
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Mid-frequency cetaceans.........  Beluga whale......  10 km (5.4 nmi)...  20 km (10.8 nmi)..  Mid-frequency BRF   5 km (2.7 nmi)....  120 dB re 1         178 dB SELcum.....  198 dB SELcum.
                                                                                               dose-response                           [micro]Pa step
                                                                                               function *.                             function.
Phocidae (in water).............  Ringed seal.......  5 km (2.7 nmi)....  10 km (5.4 nmi)...  Pinniped dose-      5 km (2.7 nmi)....  120 dB re 1         181 dB SELcum.....  201 dB SELcum.
                                                                                               response function                       [micro]Pa step
                                                                                               *.                                      function.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: The threshold values provided are assumed for when the source is within the animal's best hearing sensitivity. The exact threshold varies based on the overlap of the source and the
  frequency weighting (see figure 6-1 in IHA application).
\a\ Take is not estimated to occur beyond these cutoff distances, regardless of the received level.
\b\ Range to TTS threshold for both hearing groups for the noise associated with icebreaking in the study area is under 15 m (49.2 ft).

Level A Harassment
    NMFS' Technical Guidance for Assessing the Effects of Anthropogenic 
Sound on Marine Mammal Hearing (Version 2.0) (Technical Guidance, 2018) 
identifies dual criteria to assess auditory injury (Level A harassment) 
to five different marine mammal groups (based on hearing sensitivity) 
as a result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). The ONR's action includes the use of non-
impulsive (active sonar and icebreaking) sources; however, Level A 
harassment is not expected as a result of the activities based on 
modeling, as described below, nor is it authorized by NMFS.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS' 2018 Technical Guidance, which may be accessed at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                     PTS onset acoustic thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.

[[Page 77096]]

 
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]Pa\2\s. In this table, thresholds are abbreviated to reflect American
  National Standards Institute (ANSI) standards. However, peak sound pressure is defined by ANSI as
  incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
  ``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
  generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
  the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
  and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
  be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
  it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Quantitative Modeling

    The Navy performed a quantitative analysis to estimate the number 
of marine mammals likely to be exposed to underwater acoustic 
transmissions above the previously described threshold criteria during 
the planned action. Inputs to the quantitative analysis included marine 
mammal density estimates obtained from the Kaschner et al. (2006) 
habitat suitability model and (Ca[ntilde]adas et al., 2020), marine 
mammal depth occurrence (U.S. Department of the Navy, 2017b), 
oceanographic and mammal hearing data, and criteria and thresholds for 
levels of potential effects. The quantitative analysis consists of 
computer modeled estimates and a post-model analysis to determine the 
number of potential animal exposures. The model calculates sound energy 
propagation from the non-impulsive acoustic sources, the sound received 
by animat (virtual animal) dosimeters representing marine mammals 
distributed in the area around the modeled activity, and whether the 
sound received by animats exceeds the thresholds for effects.
    The Navy developed a set of software tools and compiled data for 
estimating acoustic effects on marine mammals and we note that these 
tools do not include any quantitative adjustments to account for the 
fact that marine mammals are likely to avoid loud sources to some 
degree, or that the successful implementation of mitigation would be 
expected to reduce the probability or severity of some impacts. These 
tools and data sets serve as integral components of the Navy Acoustic 
Effects Model (NAEMO). In NAEMO, animats are distributed non-uniformly 
based on species-specific density, depth distribution, and group size 
information and animats record energy received at their location in the 
water column. A fully three-dimensional environment is used for 
calculating sound propagation and animat exposure in NAEMO. Site-
specific bathymetry, sound speed profiles, wind speed, and bottom 
properties are incorporated into the propagation modeling process. 
NAEMO calculates the likely propagation for various levels of energy 
(sound or pressure) resulting from each source used during the training 
event.
    NAEMO then records the energy received by each animat within the 
energy footprint of the event and calculates the number of animats 
having received levels of energy exposures that fall within defined 
impact thresholds. Predicted effects on the animats within a scenario 
are then tallied and the highest order effect (based on severity of 
criteria; e.g., PTS over TTS) predicted for a given animat is assumed. 
Each scenario, or each 24-hour period for scenarios lasting greater 
than 24 hours is independent of all others, and therefore, the same 
individual marine mammal (as represented by an animat in the model 
environment) could be impacted during each independent scenario or 24-
hour period. In few instances, although the activities themselves all 
occur within the study location, sound may propagate beyond the 
boundary of the study area. Any exposures occurring outside the 
boundary of the study area are counted as if they occurred within the 
study area boundary. NAEMO provides the initial estimated impacts on 
marine species with a static horizontal distribution (i.e., animats in 
the model environment do not move horizontally).
    There are limitations to the data used in the acoustic effects 
model, and the results must be interpreted within this context. While 
the best available data and appropriate input assumptions have been 
used in the modeling, when there is a lack of definitive data to 
support an aspect of the modeling, conservative modeling assumptions 
have been chosen (i.e., assumptions that may result in an overestimate 
of acoustic exposures):
     Animats are modeled as being underwater, stationary, and 
facing the source and therefore always predicted to receive the maximum 
potential sound level at a given location (i.e., no porpoising or 
pinnipeds' heads above water);
     Animats do not move horizontally (but change their 
position vertically within the water column), which may overestimate 
physiological effects such as hearing loss, especially for slow moving 
or stationary sound sources in the model;
     Animats are stationary horizontally and therefore do not 
avoid the sound source, unlike in the wild where animals would most 
often avoid exposures at higher sound levels, especially those 
exposures that may result in PTS;
     Multiple exposures within any 24-hour period are 
considered one continuous exposure for the purposes of calculating 
potential threshold shift, because there are not sufficient data to 
estimate a hearing recovery function for the time between exposures; 
and
     Mitigation measures were not considered in the model. In 
reality, sound-producing activities will be reduced, stopped, or 
delayed if marine mammals are detected by visual monitoring.
    Due to these inherent model limitations and simplifications, model-
estimated results should be further analyzed, considering such factors 
as the range to specific effects, avoidance, and the likelihood of 
successfully implementing mitigation measures. This analysis uses a 
number of factors in addition to the acoustic model results to predict 
acoustic effects on marine mammals, as described below in the Marine 
Mammal Occurrence and Take Estimation section.
    The underwater radiated noise signature for icebreaking in the 
central Arctic Ocean by CGC HEALY during different types of ice-cover 
was characterized in Roth et al. (2013). The radiated noise signatures 
were characterized for various fractions of ice cover. For modeling, 
the 8/10 and 3/10 ice cover were used. Each modeled day of icebreaking 
consisted of 16 hours of 8/10 ice cover and 8 hours of 3/10 ice cover. 
Icebreaking was modeled for 8 days total. Since ice forecasting cannot 
be predicted more than a few weeks in advance, it is unknown if 
icebreaking will be needed to deploy or retrieve the sources after 1 
year of transmitting. Therefore, the potential for an icebreaking 
cruise on CGC HEALY was conservatively analyzed within the ONR's 
request for an IHA. As the R/V Sikuliaq is not capable of icebreaking, 
acoustic noise created by icebreaking is only modeled for the CGC 
HEALY. Figures 5a and 5b in Roth et al. (2013) depict the source 
spectrum level versus frequency for 8/10 and 3/10 ice cover, 
respectively. The sound signature of each of the ice coverage levels 
was broken into 1-octave bins (table 5). In

[[Page 77097]]

the model, each bin was included as a separate source on the modeled 
vessel. When these independent sources go active concurrently, they 
simulate the sound signature of CGC HEALY. The modeled source level 
summed across these bins was 196.2 dB for the 8/10 signature and 189.3 
dB for the 3/10 ice signature. These source levels are a good 
approximation of the icebreaker's observed source level (provided in 
figure 4b of Roth et al. (2013). Each frequency and source level was 
modeled as an independent source, and applied simultaneously to all of 
the animats within NAEMO. Each second was summed across frequency to 
estimate SPLRMS. Any animat exposed to sound levels greater 
than 120 dB was considered a take by Level B harassment. For PTS and 
TTS, determinations, sound exposure levels were summed over the 
duration of the test and the transit to the deep water deployment area. 
The method of quantitative modeling for icebreaking is considered to be 
a conservative approach; therefore, the number of takes estimated for 
icebreaking are likely an overestimate and are not expected to reach 
that level.

  Table 5--Modeled Bins for 8/10 Ice Coverage (Full Power) and 3/10 Ice
            Coverage (Quarter Power) Icebreaking on CGC HEALY
------------------------------------------------------------------------
                                8/10 source level     3/10 source level
       Frequency (Hz)                 (dB)                  (dB)
------------------------------------------------------------------------
25..........................                   189                   187
50..........................                   188                   182
100.........................                   189                   179
200.........................                   190                   177
400.........................                   188                   175
800.........................                   183                   170
1,600.......................                   177                   166
3,200.......................                   176                   171
6,400.......................                   172                   168
12,800......................                   167                   164
------------------------------------------------------------------------

Marine Mammal Occurrence and Take Estimation

    In this section we provide information about the occurrence of 
marine mammals, including density or other relevant information which 
will inform the take calculations. We also describe how the marine 
mammal occurrence information is synthesized to produce a quantitative 
estimate of the take that is reasonably likely to occur and is 
authorized.
    The beluga whale density numbers utilized for quantitative acoustic 
modeling are from the Navy Marine Species Density Database (U.S. 
Department of the Navy, 2014). Where available (i.e., June through 15 
October over the continental shelf primarily), density estimates used 
were from Duke density modeling based upon line-transect surveys 
(Ca[ntilde]adas et al., 2020). The remaining seasons and geographic 
area were based on the habitat-based modeling by Kaschner (2004) and 
Kaschner et al. (2006). Density for beluga whales was not distinguished 
by stock and varied throughout the project area geographically and 
monthly; the range of densities in the study area is shown in table 6. 
The density estimates for ringed seals are based on the habitat 
suitability modeling by Kaschner (2004) and Kaschner et al. (2006) and 
shown in table 6.

                                 Table 6--Density Estimates of Impacted Species
----------------------------------------------------------------------------------------------------------------
              Common name                            Stock                       Density (animals/km\2\)
----------------------------------------------------------------------------------------------------------------
Beluga whale..........................  Beaufort Sea..................  0.000506 to 0.5176.
Beluga whale..........................  Eastern Chukchi Sea...........  0.000506 to 0.5176.
Ringed seal...........................  Arctic........................  0.1108 to 0.3562.
----------------------------------------------------------------------------------------------------------------

    Take of all species will occur by Level B harassment only. NAEMO 
was previously used to produce a qualitative estimate of PTS, TTS, and 
behavioral exposures for ringed seals. For this action, a new approach 
that utilizes sighting data from previous surveys conducted within the 
study area was used to estimate Level B harassment associated with non-
impulsive active acoustic sources for ringed seals (see section 6.4.3 
of the IHA application).
    Of historical sightings registered in the Ocean Biodiversity 
Information System Spatial Ecological Analysis of Megavertebrate 
Populations (OBIS-SEAMAP database) (Halpin et al., 2009) in the ARA 
study area, nearly all (99 percent) occurred in summer and fall 
seasons. However, there is no documentation to prove that this is 
because ringed seals will all move out of the study area during the 
cold season, or if the lack of sightings is due to the harsh 
environment and ringed seal behavior being prohibitive factors for cold 
season surveying. OBIS-SEAMAP reports 542 animals sighted over 150 
records in the ARA study area across all years and seasons. Taking the 
average of 542 animals in 150 records aligns with survey data from 
previous ARA cruises that show up to 3 ringed seals (or small, 
unidentified pinnipeds assumed to be ringed seals) per day sighted in 
the study area. To account for any unsighted animals, that number was 
rounded up to 4. Assuming that four animals will be present in the 
study area, a rough estimate of density can be calculated using the 
overall study area size:

4 ringed seals / 48,725 km\2\ = 0.00008209 ringed seals/km\2\

    The Level B harassment zone surrounding each moored source will be 
78.5 km\2\, and the Level B harassment zone surrounding each drifting 
source will be 314 km\2\. The total Level B harassment zone on any 
given day from

[[Page 77098]]

non-impulsive acoustic sources will be 942 km\2\. The number of ringed 
seals that could be taken daily can be calculated:

0.00008209 ringed seals/km\2\ x 942 km\2\ = 0.077 ringed seals/day

    To be conservative, the ONR assumed 1 ringed seal will be exposed 
to acoustic transmissions above the threshold for Level B harassment, 
and that each will be exposed each day of the planned action (365 days 
total). Unlike the NAEMO modeling approach used to estimate ringed seal 
takes in previous ARA IHAs, the occurrence method used in this ARA IHA 
request does not support the differentiation between behavioral or TTS 
exposures. Therefore, all takes are classified as Level B harassment 
and not further distinguished. Modeling for all previous years of ARA 
activities did not result in any estimated Level A harassment. NMFS has 
no reason to expect that the ARA activities during the effective dates 
of this IHA will be more likely to result in Level A harassment. 
Therefore, no Level A harassment is anticipated due to the planned 
action.
    NAEMO modeling is still used to provide estimated takes of beluga 
whales associated with non-impulsive acoustic sources, as well as 
provide take estimations associated with icebreaking for both species. 
Table 7 shows the total number of requested takes by Level B harassment 
that NMFS has authorized for both beluga whale stocks and the Arctic 
ringed seal stock.
    Density estimates for beluga whales are equal as estimates were not 
distinguished by stock (Kaschner, 2004; Kaschner et al., 2006). The 
ranges of the Beaufort Sea and Eastern Chukchi Sea beluga whales vary 
within the study area throughout the year (Hauser et al., 2014). Based 
upon the limited information available regarding the expected spatial 
distributions of each stock within the study area, take has been 
apportioned equally to each stock (table 7). In addition, in NAEMO, 
animats do not move horizontally or react in any way to avoid sound, 
therefore, the current model may overestimate non-impulsive acoustic 
impacts.

                                                Table 7--Estimated Take Numbers and Total Take Authorized
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Active      Icebreaking     Icebreaking    Total take                         Percentage of
              Species                       Stock          acoustics    (behavioral)        (TTS)       authorized      SAR abundance       population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Beluga whale......................  Beaufort Sea........      \a\ 177          \a\ 21               0           99  39,258..............              <1
Beluga whale......................  Chukchi Sea.........      \a\ 177          \a\ 21               0           99  13,305..............              <1
Ringed seal.......................  Arctic..............          365             538               1          904  UND (171, 418) \b\..              <1
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Acoustic and icebreaking exposures to beluga whales were not modeled at the stock level as the density value is not distinguished by stock in the
  Arctic for beluga whales (U.S. Department of the Navy, 2014). Estimated take of beluga whales due to active acoustics is 177 and 21 due to icebreaking
  activities, totaling 198 takes of beluga whales. The total take was evenly distributed among the two stocks.
\b\ A reliable population estimate for the entire Arctic stock of ringed seals is not available and NMFS SAR lists it as Undetermined (UND). Using a sub-
  sample of data collected from the U.S. portion of the Bering Sea (Conn et al., 2014), an abundance estimate of 171,418 ringed seals has been
  calculated but this estimate does not account for availability bias due to seals in the water or in the shore-fast ice zone at the time of the survey.
  The actual number of ringed seals in the U.S. portion of the Bering Sea is likely much higher. Using the minimum population size (Nmin = 158,507)
  based upon this negatively biased population estimate, the PBR is calculated to be 4,755 seals, although this is also a negatively biased estimate.

Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses. NMFS regulations require applicants for incidental 
take authorizations to include information about the availability and 
feasibility (economic and technological) of equipment, methods, and 
manner of conducting the activity or other means of effecting the least 
practicable adverse impact upon the affected species or stocks, and 
their habitat (50 CFR 216.104(a)(11)). The 2004 NDAA amended the MMPA 
as it relates to military readiness activities and the incidental take 
authorization process such that ``least practicable impact'' shall 
include consideration of personnel safety, practicality of 
implementation, and impact on the effectiveness of the military 
readiness activity.
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, NMFS 
considers two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat, as 
well as subsistence uses. This considers the nature of the potential 
adverse impact being mitigated (likelihood, scope, range). It further 
considers the likelihood that the measure will be effective if 
implemented (probability of accomplishing the mitigating result if 
implemented as planned), the likelihood of effective implementation 
(probability implemented as planned), and;
    (2) The practicability of the measures for applicant 
implementation, which may consider 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.
    The following measures are required in this IHA:
     All vessels operated by or for the Navy must have 
personnel assigned to stand watch at all times while underway. Watch 
personnel must employ visual search techniques using binoculars. While 
underway and while using active acoustic sources/towed in-water 
devices, at least one person with access to binoculars is required to 
be on watch at all times.
     Vessel captains and vessel personnel must remain alert at 
all times, proceed with extreme caution, and operate at a safe speed so 
that the vessel can take proper and effective action to avoid any 
collisions with marine mammals.
     During moored and drifting acoustic source deployment and 
recovery, ONR must implement a mitigation zone of 55 m (180 ft) around 
the deployed source. Deployment and recovery must cease if a marine 
mammal is visually deterred within the mitigation zone. Deployment and 
recovery may recommence if any one of the following conditions are met:
    [cir] The animal is observed exiting the mitigation zone;
    [cir] The animal is thought to have exited the mitigation zone 
based on a determination of its course, speed, and movement relative to 
the sound source;

[[Page 77099]]

    [cir] The mitigation zone has been clear from any additional 
sightings for a period of 15 minutes for pinnipeds and 30 minutes for 
cetaceans.
     Vessels must avoid approaching marine mammals head-on and 
must maneuver to maintain a mitigation zone of 457 m (500 yards) around 
all observed cetaceans and 183 m (200 yards) around all other observed 
marine mammals, provided it is safe to do so.
     Activities must cease if a marine mammal species for which 
take was not authorized, or a species for which authorization was 
granted but the authorized number of takes have been met, is observed 
approaching or within the mitigation zone (table 8). Activities must 
not resume until the animal is confirmed to have left the area.
     Vessel captains must maintain at-sea communication with 
subsistence hunters to avoid conflict of vessel transit with hunting 
activity.

                                            Table 8--Mitigation Zones
----------------------------------------------------------------------------------------------------------------
       Activity and/or effort type                  Species                         Mitigation zone
----------------------------------------------------------------------------------------------------------------
Acoustic source deployment and recovery,  Beluga whale...............  55 m (180 ft).
 stationary.
Acoustic source deployment and recovery,  Ringed seal................  55 m (180 ft).
 stationary.
Transit.................................  Beluga whale...............  457 m (500 yards).
Transit.................................  Ringed seal................  183 m (200 yards).
----------------------------------------------------------------------------------------------------------------

    Based on our evaluation of the applicant's planned measures, NMFS 
has determined that the mitigation measures provide the means of 
effecting the least practicable impact on the affected species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, areas of similar significance, and on the availability 
of such species or stock for subsistence uses.

Monitoring and Reporting

    In order to issue an IHA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present while 
conducting the activities. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the activity; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and,
     Mitigation and monitoring effectiveness.
    The Navy has coordinated with NMFS to develop an overarching 
program plan in which specific monitoring will occur. This plan is 
called the Integrated Comprehensive Monitoring Program (ICMP) (U.S. 
Department of the Navy, 2011). The ICMP has been developed in direct 
response to Navy permitting requirements established through various 
environmental compliance efforts. As a framework document, the ICMP 
applies by regulation to those activities on ranges and operating areas 
for which the Navy is seeking or has sought incidental take 
authorizations. The ICMP is intended to coordinate monitoring efforts 
across all regions and to allocate the most appropriate level and type 
of effort based on a set of standardized research goals, and in 
acknowledgement of regional scientific value and resource availability.
    The ICMP is focused on Navy training and testing ranges where the 
majority of Navy activities occur regularly as those areas have the 
greatest potential for being impacted. ONR's ARA in comparison is a 
less intensive test with little human activity present in the Arctic. 
Human presence is limited to the deployment of sources that will take 
place over several weeks. Additionally, due to the location and nature 
of the testing, vessels and personnel will not be within the study area 
for an extended period of time. As such, more extensive monitoring 
requirements beyond the basic information being collected will not be 
feasible as it would require additional personnel and equipment to 
locate seals and a presence in the Arctic during a period of time other 
then what is planned for source deployment. However, ONR will record 
all observations of marine mammals, including the marine mammal's 
species identification, location (latitude/longitude), behavior, and 
distance from project activities. ONR will also record date and time of 
sighting. This information is valuable in an area with few recorded 
observations.
    Marine mammal monitoring must be conducted in accordance with the 
Navy's ICMP and the IHA:
     While underway, all vessels must have at least one person 
trained through the U.S. Navy Marine Species Awareness Training Program 
on watch during all activities;
     Watch personnel must use standardized data collection 
forms, whether hard copy or electronic. Watch personnel must 
distinguish between sightings that occur during transit or during 
deployment or recovery of acoustic sources. Data must be recorded on 
all days of activities, even if marine mammals are not sighted;
     At minimum, the following information must be recorded:
    [cir] Vessel name;
    [cir] Watch personnel names and affiliation;
    [cir] Effort type (i.e., transit, deployment, recovery); and
    [cir] Environmental conditions (at the beginning of watch stander 
shift and

[[Page 77100]]

whenever conditions change significantly), including Beaufort Sea State 
(BSS) and any other relevant weather conditions, including cloud cover, 
fog, sun glare, and overall visibility to the horizon.
     Upon visual observation of any marine mammal, the 
following information must be recorded:
    [cir] Date/time of sighting;
    [cir] Identification of animal (e.g., genus/species, lowest 
possible taxonomic level, or unidentified) and the composition of the 
group if there is a mix of species;
    [cir] Location (latitude/longitude) of sighting;
    [cir] Estimated number of animals (high/low/best);
    [cir] Description (as many distinguishing features as possible of 
each individual seen, including length, shape, color, pattern, scars or 
markings, shape and size of dorsal fin, shape of head, and blow 
characteristics);
    [cir] Detailed behavior observations (e.g., number of blows/
breaths, number of surfaces, breaching, spyhopping, diving, feeding, 
traveling; as explicit and detailed as possible; length of time 
observed in the mitigation zone, note any observed changes in 
behavior);
    [cir] Distance from vessel to animal;
    [cir] Direction of animal's travel relative to the vessel;
    [cir] Platform activity at time of sighting (i.e., transit, 
deployment, recovery); and
    [cir] Weather conditions (i.e., BSS, cloud cover).
    [cir] During icebreaking, the following information must be 
recorded:
    [cir] Start and end time of icebreaking; and
    [cir] Ice cover conditions.
     During deployment and recovery of acoustic sources or 
unmanned undersea vehicles, visual observation must begin 30 minutes 
prior to deployment or recovery and continue through 30 minutes 
following the source deployment or recovery.
     The ONR must submit its draft report(s) on all monitoring 
conducted under the IHA within 90 calendar days of the completion of 
monitoring or 60 calendar days prior to the requested issuance of any 
subsequent IHA for research activities at the same location, whichever 
comes first. A final report must be prepared and submitted within 30 
calendar days following receipt of any NMFS comments on the draft 
report. If no comments are received from NMFS within 30 calendar days 
of receipt of the draft report, the report shall be considered final.
     All draft and final monitoring reports must be submitted 
to [email protected] and [email protected].
     The marine mammal report, at minimum, must include:
    [cir] Dates and times (begin and end) of all marine mammal 
monitoring;
    [cir] Acoustic source use or icebreaking;
    [cir] Watch stander location(s) during marine mammal monitoring;
    [cir] Environmental conditions during monitoring periods (at 
beginning and end of watch standing shift and whenever conditions 
change significantly), including BSS and any other relevant weather 
conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance;
    [cir] Upon observation of a marine mammal, the following 
information:
    [ssquf] Name of watch stander who sighted the animal(s), the watch 
stander location, and activity at time of sighting;
    [ssquf] Time of sighting;
    [ssquf] Identification of the animal(s) (e.g., genus/species, 
lowest possible taxonomic level, or unidentified), watch stander 
confidence in identification, and the composition of the group if there 
is a mix of species;
    [ssquf] Distance and location of each observed marine mammal 
relative to the acoustic source or icebreaking for each sighting;
    [ssquf] Estimated number of animals (min/max/best estimate);
    [ssquf] Estimated number of animals by cohort (adults, juveniles, 
neonates, group composition, etc.);
    [ssquf] Animal's closest point of approach and estimated time spent 
within the harassment zone; and
    [ssquf] Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as feeding or traveling), including an 
assessment of behavioral responses thought to have resulted from the 
activity (e.g., no response or changes in behavioral state such as 
ceasing feeding, changing direction, flushing, or breaching.
    [cir] Number of shutdowns during monitoring, if any;
    [cir] Marine mammal sightings (including the marine mammal's 
location (latitude/longitude));
    [cir] Number of individuals of each species observed during source 
deployment, operation, and recovery; and
    [cir] Detailed information about implementation of any mitigation 
(e.g., shutdowns, delays), a description of specific actions that 
ensued, and resulting changes in behavior of the animal(s), if any.
     The ONR must submit all watch stander data electronically 
in a format that can be queried, such as a spreadsheet or database 
(i.e., digital images of data sheets are not sufficient).
     Reporting injured or dead marine mammals:
    [cir] In the event that personnel involved in the specified 
activities discover an injured or dead marine mammal, the ONR must 
report the incident to the Office of Protected Resources (OPR), NMFS 
([email protected] and [email protected]) and to 
the Alaska regional stranding network (877-925-7773) as soon as 
feasible. If the death or injury was clearly caused by the specified 
activity, the ONR must immediately cease the activities until NMFS OPR 
is able to review the circumstances of the incident and determine what, 
if any, additional measures are appropriate to ensure compliance with 
the terms of this IHA. The ONR must not resume their activities until 
notified by NMFS.
    [cir] The report must include the following information:
    [ssquf] Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    [ssquf] Species identification (if known) or description of the 
animal(s) involved;
    [ssquf] Condition of the animal(s) (including carcass condition if 
the animal is dead);
    [ssquf] Observed behaviors of the animal(s), if alive;
    [ssquf] If available, photographs or video footage of the 
animal(s); and
    [ssquf] General circumstances under which the animal was 
discovered.
     Vessel Strike: In the event of a vessel strike of a marine 
mammal by any vessel involved in the activities covered by the 
authorization, the ONR shall report the incident to OPR, NMFS and to 
the Alaska regional stranding coordinator (877-925-7773) as soon as 
feasible. The report must include the following information:
    [cir] Time, date, and location (latitude/longitude) of the 
incident;
    [cir] Species identification (if known) or description of the 
animal(s) involved;
    [cir] Vessel's speed during and leading up to the incident;
    [cir] Vessel's course/heading and what operations were being 
conducted (if applicable);
    [cir] Status of all sound sources in use;
    [cir] 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 strike;
    [cir] Environmental conditions (e.g., wind speed and direction, 
BSS, cloud cover, visibility) immediately preceding the strike;
    [cir] Estimated size and length of animal that was struck;

[[Page 77101]]

    [cir] Description of the behavior of the marine mammal immediately 
preceding and following the strike;
    [cir] If available, description of the presence and behavior of any 
other marine mammals immediately preceding the strike;
    [cir] Estimated fate of the animal (e.g., dead, injured but alive, 
injured and moving, blood or tissue observed in the water, status 
unknown, disappeared); and
    [cir] To the extent practicable, photographs or video footage of 
the animal(s).

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 estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any impacts or responses (e.g., intensity, duration), 
the context of any impacts or responses (e.g., critical reproductive 
time or location, foraging impacts affecting energetics), as well as 
effects on habitat, and the likely effectiveness of the mitigation. We 
also assess the number, intensity, and context of estimated takes by 
evaluating this information relative to population status. Consistent 
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338, 
September 29, 1989), the impacts from other past and ongoing 
anthropogenic activities are incorporated into this analysis via their 
impacts on the 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 analysis applies to 
beluga whales and ringed seals, given that the anticipated effects of 
this activity on these different marine mammal stocks are expected to 
be similar. Where there are meaningful differences between species or 
stocks, or groups of species, in anticipated individual responses to 
activities, impact of expected take on the population due to 
differences in population status, or impacts on habitat, they are 
described independently in the analysis below.
    Underwater acoustic transmissions associated with the ARA, as 
outlined previously, have the potential to result in Level B harassment 
of beluga seals and ringed seals in the form of behavioral 
disturbances. No serious injury, mortality, or Level A harassment are 
anticipated to result from these described activities. Effects on 
individual belugas or ringed seals taken by Level B harassment could 
include alteration of dive behavior and/or foraging behavior, effects 
to breathing rates, interference with or alteration of vocalization, 
avoidance, and flight. More severe behavioral responses are not 
anticipated due to the localized, intermittent use of active acoustic 
sources. Exposure duration is likely to be short-term and individuals 
will, most likely, simply be temporarily displaced by moving away from 
the acoustic source. Exposures are, therefore, unlikely to result in 
any significant realized decrease in fitness for affected individuals 
or adverse impacts to stocks as a whole.
    Arctic ringed seals are listed as threatened under the ESA. The 
primary concern for Arctic ringed seals is the ongoing and anticipated 
loss of sea ice and snow cover resulting from climate change, which is 
expected to pose a significant threat to ringed seals in the future 
(Muto et al., 2021). In addition, Arctic ringed seals have also been 
experiencing an Unusual Mortality Event (UME) since 2019 although the 
cause of the UME is currently undetermined. As mentioned earlier, no 
mortality or serious injury to ringed seals is authorized. Due to the 
short-term duration of expected exposures and required mitigation 
measures to reduce adverse impacts, we do not expect the ARA to 
compound or exacerbate the impacts of the ongoing UME.
    A small portion of the study area overlaps with ringed seal 
critical habitat. Although this habitat contains features necessary for 
ringed seal formation and maintenance of subnivean birth lairs, basking 
and molting, and foraging, these features are also available throughout 
the rest of the designated critical habitat area. Any potential limited 
displacement of ringed seals from the ARA study area is not expected to 
interfere with their ability to access necessary habitat features, 
given the availability of similar necessary habitat features nearby.
    The study area also overlaps with beluga whale migratory and 
feeding biologically important areas (BIAs). Due to the small amount of 
overlap between the BIAs and the ARA study area as well as the low 
intensity and short-term duration of acoustic sources and required 
mitigation measures, we expect minimal impacts to migrating or feeding 
belugas. Shutdown zones are expected to avoid the potential for Level A 
harassment of belugas and ringed seals, and to minimize the severity of 
any Level B harassment. The requirements of trained dedicated watch 
personnel and speed restrictions will also reduce the likelihood of any 
vessel strikes to migrating belugas.
    In all, the planned activities are expected to have minimal adverse 
effects on marine mammal habitat. While the activities may cause some 
fish to leave the area of disturbance, temporarily impacting marine 
mammals' foraging opportunities, this will encompass a relatively small 
area of habitat leaving large areas of existing fish and marine mammal 
foraging habitat unaffected. As such, the impacts to marine mammal 
habitat are not expected to impact the health or fitness of any marine 
mammals.
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect any of the species or stocks 
through effects on annual rates of recruitment or survival:
     No serious injury or mortality is anticipated or 
authorized;
     Impacts will be limited to Level B harassment only;
     Only temporary and relatively low-level behavioral 
disturbances are expected to result from these activities; and
     Impacts to marine mammal prey or habitat will be minimal 
and short term.
    The authorized take is not expected to impact the reproduction or 
survival of any individual marine mammals, much less rates of 
recruitment or survival. 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 
planned monitoring and mitigation measures, NMFS finds that the total 
marine mammal take from the planned activity will have a negligible 
impact on all affected marine mammal species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    In order to issue an IHA, NMFS must find that the specified 
activity will not have an ``unmitigable adverse impact'' on the 
subsistence uses of the affected

[[Page 77102]]

marine mammal species or stocks by Alaskan Natives. NMFS has defined 
``unmitigable adverse impact'' in 50 CFR 216.103 as an impact resulting 
from the specified activity: (1) That is likely to reduce the 
availability of the species to a level insufficient for a harvest to 
meet subsistence needs by: (i) Causing the marine mammals to abandon or 
avoid hunting areas; (ii) Directly displacing subsistence users; or 
(iii) Placing physical barriers between the marine mammals and the 
subsistence hunters; and (2) That cannot be sufficiently mitigated by 
other measures to increase the availability of marine mammals to allow 
subsistence needs to be met.
    Subsistence hunting is important for many Alaska Native 
communities. A study of the North Slope villages of Nuiqsut, Kaktovik, 
and Utqia[gdot]vik identified the primary resources used for 
subsistence and the locations for harvest (Stephen R. Braund & 
Associates, 2010), including terrestrial mammals, birds, fish, and 
marine mammals (bowhead whale, ringed seal, bearded seal, and walrus). 
Ringed seals and beluga whales are likely located within the project 
area during this action, yet the action will not remove individuals 
from the population nor behaviorally disturb them in a manner that will 
affect their behavior more than 100 km farther inshore where 
subsistence hunting occurs. The acoustic sources will be placed far 
outside of the range for subsistence hunting. The closest active 
acoustic source (fixed or drifting) within the study area that is 
likely to cause Level B harassment is approximately 204 km (110 nmi) 
from land. This ensures a significant standoff distance from any 
subsistence hunting area. The closest distance to subsistence hunting 
(130 km (70 nmi)) is well beyond the largest distance from the sound 
sources in use at which behavioral harassment will be expected to occur 
(20 km (10.8 nmi)) described above. Furthermore, there is no reason to 
believe that any behavioral disturbance of beluga whales or ringed 
seals that occurs far offshore (we do not anticipate any Level A 
harassment) will affect their subsequent behavior in a manner that will 
interfere with subsistence uses should those animals later interact 
with hunters.
    In addition, ONR has been communicating with the Native communities 
about the planned action. The ONR-sponsored chief scientist for AMOS 
gave a briefing on ONR research planned for 2024-2025 Alaska Eskimo 
Whaling Commission (AEWC) meeting on December 15, 2023 in Anchorage, 
Alaska. No questions were asked from the commissioners during the brief 
or in subsequent weeks afterwards. The AEWC consists of representatives 
from 11 whaling villages (Wainwright, Utqia[gdot]vik, Savoonga, Point 
Lay, Nuiqut, Kivalina, Kaktovik, Wales, Point Hope, Little Diomede, and 
Gambell). These briefings have communicated the lack of any effect on 
subsistence hunting due to the distance of the sources from hunting 
areas. ONR-supported scientists also attend Arctic Waterways Safety 
Committee (AWSC) and AEWC meetings on a regular basis to discuss past, 
present, and future research activities. While no take is anticipated 
to result during transit, points of contact for at-sea communication 
will also be established between vessel captains and subsistence 
hunters to avoid any conflict of vessel transit with hunting activity.
    Based on the description of the specified activity, distance of the 
study area from subsistence hunting grounds, the measures described to 
minimize adverse effects on the availability of marine mammals for 
subsistence purposes, and the planned mitigation and monitoring 
measures, NMFS has determined that there will not be an unmitigable 
adverse impact on subsistence uses from ONR's ARA.

Peer Review of the Monitoring Plan

    The MMPA requires that monitoring plans be independently peer 
reviewed where the activity may affect the availability of a species or 
stock for taking for subsistence uses (16 U.S.C. 
1371(a)(5)(D)(ii)(III)). Given the factors discussed above, NMFS has 
also determined that the activity is not likely to affect the 
availability of any marine mammal species or stock for taking for 
subsistence uses, and therefore, peer review of the monitoring plan is 
not warranted for this project.

Endangered Species Act

    Section 7(a)(2) of the ESA of 1973 (16 U.S.C. 1531 et seq.) 
requires that each Federal agency insure that any action it authorizes, 
funds, or carries out is not likely to jeopardize the continued 
existence of any endangered or threatened species or result in the 
destruction or adverse modification of designated critical habitat. To 
ensure ESA compliance for the issuance of IHAs, NMFS consults 
internally whenever we propose to authorize take for endangered or 
threatened species, in this case with the Alaska Regional Office (AKR).
    There is one marine mammal species (Arctic ringed seal) with 
confirmed occurrence in the study area that is listed as threatened 
under the ESA. The NMFS AKR Protected Resources Division issued a 
Biological Opinion on September 13, 2022, under section 7 of the ESA, 
on the issuance of an IHA to ONR under section 101(a)(5)(D) of the MMPA 
by the NMFS Permits and Conservation Division. The 2022 Biological 
Opinion is based on a Biological Evaluation that covers ONR's ARA from 
2022-2025. Therefore, NMFS has determined that issuance of this IHA is 
covered by the 2022 Biological Opinion and that further consultation is 
unnecessary. The Biological Opinion concluded that the action is not 
likely to jeopardize the continued existence of Arctic ringed seals, 
and is not likely to destroy or adversely modify Arctic ringed seal 
critical habitat.

National Environmental Policy Act

    In compliance with the National Environmental Policy Act of 1969 
(NEPA; 42 U.S.C. 4321 et seq.) as implemented by the regulations 
published by the Council on Environmental Quality (CEQ; 40 CFR parts 
1500-1508), the ONR prepared an Overseas Environmental Assessment (OEA) 
to consider the direct, indirect, and cumulative effects to the human 
environment resulting from the ARA project. NMFS made the ONR's OEA 
available to the public for review and comment, concurrently with the 
publication of the proposed IHA, on the NMFS website (at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities), in relation to its 
suitability for adoption by NMFS in order to assess the impacts to the 
human environment of issuance of an IHA to ONR. Also in compliance with 
NEPA and the CEQ regulations, as well as NOAA Administrative Order 216-
6A, NMFS has reviewed ONR's OEA, determined it to be sufficient, and 
adopted that OEA and signed a Finding of No Significant Impact (FONSI) 
on September 14, 2024.

Authorization

    NMFS has issued an IHA to ONR for the potential harassment of two 
marine mammal species incidental to conducting a seventh year of ARA in 
the Beaufort and Chukchi Seas that includes the previously explained 
mitigation, monitoring, and reporting requirements.

    Dated: September 17, 2024.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2024-21561 Filed 9-19-24; 8:45 am]
BILLING CODE 3510-22-P