[Federal Register Volume 87, Number 28 (Thursday, February 10, 2022)]
[Notices]
[Pages 7803-7820]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-02800]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XB657]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to U.S. Navy 2022 Ice Exercise 
Activities in the Arctic Ocean

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 U.S. Navy (Navy) to incidentally harass, by Level B harassment 
only, marine mammals during submarine training and testing activities 
including establishment of a tracking range on an ice floe in the 
Arctic Ocean, north of Prudhoe Bay, Alaska. The Navy'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 February 4, 2022 through 
April 30, 2022.

FOR FURTHER INFORMATION CONTACT: Leah Davis, Office of Protected 
Resources, NMFS, (301) 427-8401. 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 these documents, please call the contact listed above.

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 incidental harassment authorization 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 mitigation, 
monitoring, and reporting of the takings are set forth.
    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 here qualifies as a military readiness 
activity. The definitions of all applicable MMPA statutory terms cited 
above are included in the relevant sections below.

Summary of Request

    On August 26, 2021, NMFS received a request from the Navy for an 
IHA to take marine mammals incidental to submarine training and testing 
activities including establishment of a tracking range on an ice floe 
in the Arctic Ocean, north of Prudhoe Bay, Alaska. The application was 
deemed adequate and complete on November 4, 2021. The Navy's request is 
for take of ringed seals (Pusa hispida) by Level B harassment only. 
Neither the Navy nor NMFS expects serious injury or mortality to result 
from this activity and, therefore, an IHA is appropriate.
    NMFS previously issued IHAs to the Navy for similar activities (83 
FR 6522; February 14, 2018, 85 FR 6518; February 5, 2020). The Navy 
complied with all the requirements (e.g., mitigation,

[[Page 7804]]

monitoring, and reporting) of the previous IHAs and information 
regarding their monitoring results may be found below, in the Estimated 
Take section.

Description of the Specified Activity

    The Navy proposes to conduct submarine training and testing 
activities, which includes the establishment of a tracking range and 
temporary ice camp, and research in the Arctic Ocean for six weeks 
beginning in February 2022. Submarine active acoustic transmissions may 
result in occurrence of Level B harassment, including temporary hearing 
impairment (temporary threshold shift (TTS)) and behavioral harassment, 
of ringed seals. A detailed description of the planned 2022 Ice 
Exercise (ICEX22) activities is provided in the Federal Register notice 
for the proposed IHA (86 FR 70451; December 10, 2021). Since that time, 
no changes have been made to the planned ICEX22 activities. Therefore, 
a detailed description is not provided here. Please refer to that 
Federal Register notice for the description of the specific activity.

Comments and Responses

    A notice of NMFS's proposal to issue an IHA to the Navy was 
published in the Federal Register on December 10, 2021 (86 FR 70451). 
That notice described, in detail, the Navy's activity, the marine 
mammal species that may be affected by the activity, and the 
anticipated effects on marine mammals. During the 30-day public comment 
period, NMFS received comments from the Center for Biological Diversity 
(CBD) and a member of the general public. Please see the CBD's letter 
for full details regarding their recommendations and rationale. The 
letter is available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities. A summary of all substantive comments as well as 
NMFS' responses is below.
    Comment 1: CBD asserted that annual mortality and serious injury 
[for ringed seals] already exceeds Potential Biological Removal (PBR) 
and therefore additional take is not negligible and thus should not be 
authorized. CBD stated that the rationale that the stock's population 
estimate is an underestimate because it is only a partial stock 
abundance is insufficient, and NMFS must therefore determine what the 
appropriate stock abundance and PBR are.
    Response: PBR is defined in section 3 of 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'' and, although not 
controlling, can be one measure considered among other factors when 
evaluating the effects of morality and serious injury (M/SI) on a 
marine mammal species or stock during the section 101(a)(5)(A) process. 
As stated in Muto et al. (2021), PBR ``is defined as the product of the 
minimum population estimate, one-half the maximum theoretical net 
productivity rate, and a recovery factor: PBR = NMIN x 0.5RMAX x FR.''
    No serious injury or mortality is expected or authorized in this 
IHA and neither is the take by harassment expected to accrue in a 
manner that will impact the reproduction or survival of any individual 
marine mammals. Therefore, it is neither required nor appropriate to 
directly and/or quantitatively consider PBR in the negligible impact 
analysis of the take, by harassment only, authorized in this IHA. 
Rather, PBR, and the number of known mortalities per year are 
qualitatively considered as a gross indicator of stock status in the 
baseline of this analysis. Below, we reemphasize the basis for the 
negligible impact determination and, as a secondary matter, we further 
explain that the PBR values for this stock are likely significantly 
underestimated.
    Given that the calculation is based upon the minimum population 
estimate, if a minimum population estimate is negatively biased, the 
resulting PBR would be negatively biased as well. The PBR for the 
Alaska stock of ringed seals is based upon a minimum population 
estimate which is expected to be an underestimate for multiple reasons. 
First, the minimum and best population estimates for the stock reflect 
the Bering Sea population only, as reliable abundance estimates for the 
Chukchi Sea and Beaufort Sea, which are also included in the stock's 
range, are not available. Further, the available abundance estimate for 
the Bering Sea population was not adjusted for seals in the water at 
the time of the surveys, nor does it include ringed seals in the 
shorefast ice zone; therefore, the partial abundance that is available, 
for the Bering Sea only, is an underestimate even for the Bering Sea 
portion of the stock alone. Therefore, the minimum population estimate 
(and best population estimate) and PBR for the Alaska stock of ringed 
seals are negatively biased (i.e., underestimates).
    PBR and information on annual serious injury and mortality from 
anthropogenic sources was presented in the notice of proposed IHA and 
is presented again in this notice of final IHA as gross indicators of 
the status of the Alaska stock of ringed seals, even though for the 
reasons discussed above and below, respectively, these numbers do not 
accurately reflect certain aspects of the status of the stock.
    As noted by the commenter, the abundance estimate and PBR 
considered by NMFS and included in the notice of proposed IHA (86 FR 
70451, December 10, 2021) and this final IHA, is a partial abundance, 
as reported in the 2020 Alaska Stock Assessment Report (SAR; Muto et 
al. 2021). As stated above, the partial abundance estimate reflects the 
Bering Sea population only, as reliable abundance estimates for the 
Chukchi Sea and Beaufort Sea, which are also included in the stock's 
range, are not available. Further, the available abundance estimate for 
the Bering Sea population was not adjusted for seals in the water at 
the time of the surveys, nor does it include ringed seals in the 
shorefast ice zone; therefore, the partial abundance that is available, 
for the Bering Sea only, is an underestimate even for the Bering Sea 
portion of the stock alone. And so, if a more accurate PBR were 
available, it would be higher, as it would be based on a higher, more-
accurate minimum abundance estimate. Muto et al. (2021) state that 
``researchers expect to provide a population estimate, corrected for 
availability bias, for the entire U.S. portion of the ringed seal stock 
once the final Bering Sea results are combined with the results from 
spring surveys of the Chukchi Sea (conducted in 2016) and Beaufort Sea 
(planned for 2020).'' In the meantime, given the limited available 
information at this time, NMFS is not able to produce a stock abundance 
estimate and PBR that are more accurate than what NMFS included in the 
proposed IHA.
    No serious injury or mortality is anticipated or authorized in this 
IHA. Even if serious injury and mortality from other sources (in this 
case, nearly all from Alaska Native subsistence harvest) exceeded what 
was accepted as a more accurate PBR, that would not inherently indicate 
that take by Level B harassment at the numbers and level authorized in 
this IHA would have more than a negligible impact on the stock, as 
implied by the commenter. (See further discussion below.) However, in 
this case, given that the abundance estimate and PBR are negatively 
biased for the reasons discussed above, it is unlikely that mortality 
and serious injury actually exceed the maximum number of animals, not 
including natural mortalities, that may be removed from

[[Page 7805]]

the Alaska ringed seal stock while allowing the stock to reach or 
maintain its optimum sustainable population.
    Regarding the number of takes authorized in this IHA in comparison 
to the population status, while we do typically assess the number, 
intensity, and context of estimated takes by evaluating this 
information relative to population status, as stated in the Negligible 
Impact Analysis and Determination section, NMFS also considers other 
factors, such as the likely nature of any responses (e.g., intensity, 
duration), the context of any responses (e.g., critical reproductive 
time or location, migration), as well as effects on habitat, and the 
likely effectiveness of the mitigation. Further, consistent with the 
1989 preamble for NMFS's 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 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). PBR is one consideration included in this baseline as a gross 
indicator of stock status. Explicit quantitative consideration of PBR 
in the analysis was neither required nor appropriate, given that no 
serious injury or mortality was included in the proposed IHA, and none 
is authorized in this final IHA. NMFS' preliminary and final negligible 
impact determinations do not depend solely on the stock abundance 
provided in the 2020 Alaska SAR (and the accuracy of that abundance 
estimate). An accurate abundance estimate (and minimum population 
estimate) for the entire stock, which would include the unknown number 
of animals in the Beaufort and Chukchi Seas, in addition to the Bering 
Sea population which is reported in the 2020 Alaska SAR, as well as 
adjust for uncounted animals in the water and animals in the shorefast 
ice zone at the time of the Bering Sea survey, is not necessary to make 
the negligible impact determination. (Though if a complete stock 
abundance were available, the number of takes authorized in this IHA in 
comparison to that abundance would be even lower than described in 
NMFS' Negligible Impact Analysis and Determination herein, given that 
the stock abundance would be larger.)
    As described in the Negligible Impact Analysis and Determination 
section of the notice of the proposed IHA (86 FR 70451; December 10, 
2021) and this notice, the following factors primarily support our 
negligible impact determination:
    <bullet> No Level A harassment (injury), serious injury, or 
mortality is anticipated or authorized;
    <bullet> Impacts will be limited to Level B harassment, primarily 
in the form of behavioral disturbance that results in minor changes in 
behavior;
    <bullet> TTS is expected to affect only a limited number of animals 
(approximately 0.5 percent of the partial stock abundance described in 
Table 1) and TTS is expected to be minor and short term;
    <bullet> The number of authorized takes is low relative to the 
estimated abundances of the affected stock, even given the extent to 
which abundance is significantly underestimated;
    <bullet> Submarine training and testing activities will occur over 
only 4 weeks of the total 6-week activity period;
    <bullet> There will be no loss or modification of ringed seal 
habitat and minimal, temporary impacts on prey;
    <bullet> Physical impacts to ringed seal subnivean lairs will be 
avoided; and
    <bullet> Mitigation requirements for ice camp activities will 
prevent impacts to ringed seals during the pupping season.
    Comment 2: CBD stated that the take estimates from modeling likely 
underestimate or incorrectly estimate take. NMFS relies on Navy's 
modeling and a density of 0.3957 ringed seals per km\2\. It is unclear 
if this assumes an even distribution of seals throughout the Study 
Area, which would fail to account for concentrated activities near the 
Ice Camp Study Area. NMFS stated that ``[w]hile the total ICEX22 Study 
Area is large, the Navy expects that most activities would occur within 
the Ice Camp Study Area in relatively close proximity to the ice 
camp.'' The density of ringed seals for this area has not been 
determined, and thus the modeling does not accurately estimate take. 
CBD asserted that there are likely more ringed seals near the Ice Camp 
Study Area than across the entire Study Area because they are in their 
home ranges near their subnivean lairs.
    Response: The Navy estimated take using the density of 0.3957 
ringed seals per km\2\ as noted by the commenter, and NMFS concurs that 
this is currently the best available information. Information regarding 
the density of ice seals (which include ringed seals) in the Arctic 
Ocean is sparse. While the commenter suggests that NMFS and the Navy 
should use density data that is specific to the Ice Camp Study Area and 
the area in close proximity to the ice camp, given that most of the 
activities will occur there, NMFS and the Navy are not aware of any 
such data, and the commenter did not provide or reference any data 
which it thinks would be more appropriate than that used by the Navy 
and NMFS. Further, the statement that animals occur in their home 
ranges near their subnivean lairs does not support an assertion that 
there are likely more ringed seals near the Ice Camp Study Area than in 
other areas across the entire Study Area, as an animal's home range is 
a separate concept from the density of animals in any given area.
    Comment 3: CBD stated that the assumption that having activities 
ongoing at the ice camp will dissuade ringed seals from pupping near 
the area should not be considered to mitigate harassment, and instead 
should be counted as additional take. Ringed seals build their 
subnivean lairs in habitat like that where the ice camp will be 
constructed. The proposed activities are planned during the season that 
the ringed seals give birth and raise their pups. Further, CBD stated 
that the assumption that a ringed seal may be able to relocate its pup 
or find another breathing hole due to human disturbance is na[iuml]ve 
and fails to consider the energetic cost as well as predation risk that 
these seals may face.
    Response: Regarding the potential displacement of ringed seals to 
other pupping sites, NMFS would not consider it as mitigating 
harassment, rather, in the case of ICEX, we consider it unlikely to 
occur. As a general matter, on-ice activities could cause a seal that 
would have otherwise built a lair in the area of an activity to be 
displaced and therefore, construct a lair in a different area outside 
of an activity area, or a seal could choose to relocate to a different 
existing lair outside of an activity area. However, in the case of the 
ice camp associated with ICEX22, displacement of seal lair construction 
or relocation to existing lairs outside of the ice camp area is 
unlikely, given the low average density of lairs (the average ringed 
seal lair density in the vicinity of Prudhoe Bay, Alaska is 1.58 lairs 
per km\2\ (Table 3 of the notice of the proposed IHA; 86 FR 70451, 
December 10, 2021)), the relative footprint of the Navy's planned ice 
camp (2 km\2\), the lack of previous ringed seal observations on the 
ice during ICEX activities, and mitigation requirements that require 
the Navy to construct the ice camp and runway on first-year or multi-
year ice without pressure ridges and require personnel to avoid areas 
of deep snow drift or pressure ridges. We have clarified this 
explanation in the Negligible Impact Analysis and Determination section 
of this final notice. While the commenter is correct that ringed seals 
build their subnivean lairs in habitat similar to that

[[Page 7806]]

where the ice camp will be constructed, given that mitigation measures 
require that the ice camp and runway be established on first-year or 
multi-year ice without pressure ridges, where ringed seals tend to 
build their lairs, it is extremely unlikely that a ringed seal would 
build a lair in the vicinity of the ice camp. This measure, in 
combination with the other mitigation measures required for operation 
of the ice camp are expected to avoid impacts to the construction and 
use of ringed seal subnivean lairs, particularly given the already low 
average density of lairs, as described above.
    Regarding the commenter's assertion that the assumption that a 
ringed seal may be able to relocate its pup or find another breathing 
hole due to human disturbance fails to consider the associated 
energetic cost and predation risk, NMFS has clarified in this response 
that for the reasons stated above, ringed seal lairs are not expected 
to occur in the ice camp study area, and therefore, NMFS does not 
expect ringed seals to relocate pups due to human disturbance from ice 
camp activities. Use of a breathing hole farther from the sound source, 
rather than one closer to the sound source, would be within the normal 
range of behavior (Kelly et al. 1988), and would not necessarily have 
an increased energetic cost. While relocating to a different breathing 
hole could change predation risk, such a risk is scenario-specific and 
speculative, and it is not possible to determine such risk.
    Comment 4: CBD states that NMFS failed to provide an adequate 
explanation for discounting the impacts of the unusual mortality event 
(UME) on the cumulative effects of the proposed activities. New 
research about the event (that focused on spotted and ribbon seals) 
found that the body condition of the seals had declined, likely due to 
climate-related impacts on prey (Boveng et al., 2020). This long-
lasting unusual mortality event cannot simply be ignored in the 
authorization of additional take of ice seals.
    Response: NMFS disagrees with the commenter that we ``discounted'' 
the impacts of the ice seal UME (which includes ringed seals, bearded 
seals, and spotted seals), and we have not ignored it. Rather, NMFS 
stated that the take proposed for authorization (and now authorized 
here) does not provide a concern for ringed seals when considered in 
the context of these UMEs, especially given that the anticipated low-
level and short-term take by Level B harassment is unlikely to affect 
the reproduction or survival of any individuals. That continues to be 
our conclusion. In addition, the ICEX22 Study Area is in the Arctic 
Ocean, well north and east of the primary area where seals have 
stranded along the western coast of Alaska (see map of strandings at: 
https://www.fisheries.noaa.gov/alaska/marine-life-distress/2018-2022-ice-seal-unusual-mortality-event-alaska). No Level A harassment, 
serious injury, or mortality is expected or authorized, and take by 
Level B harassment of ringed seals will be reduced to the level of 
least practicable adverse impact through the incorporation of 
mitigation measures. As such, the authorized takes by Level B 
harassment of ringed seals are not expected to exacerbate or compound 
the ongoing UME.
    NOAA is investigating the UME, and has assembled an independent 
team of scientists to coordinate with the Working Group on Marine 
Mammal Unusual Mortality Events to review the data collected, sample 
stranded seals, and determine the next steps for the investigation. 
However, the study referenced by the commenter took place in the Bering 
Sea and Aleutian Islands, far from the Navy's proposed activity, and 
was conducted on spotted seals, ribbon seals, and harbor seals, none of 
which are authorized for taking through this IHA. (The current UME does 
not include harbor seals or ribbon seals, though as noted above, it 
does include spotted seals).
    Comment 5: CBD asserted that NMFS should consider new and 
additional information on marine mammal exposure criteria (Southall et 
al. 2019; 2021). Additionally, CBD stated that NMFS relies on an 
``unsubstantiated'' cut-off distance of 10 km that according to the 
Marine Mammal Commission ``contradicts the data underlying the Bayesian 
Behavioral Response Functions (BRFs), negates the intent of the 
functions themselves, and underestimates the numbers of takes'' 
(Thomas, 2020). CBD states that NMFS should consider that at received 
levels of less than or equal to 140 dB (decibel) re 1 [mu]Pa 
(microPascal) some pinnipeds had strong reactions (Thomas, 2020).
    Response: As discussed further below, neither is the 10-km cut-off 
distance unsubstantiated nor does it contradict the BRFs. Received 
level and distance have been shown to independently affect how marine 
mammals respond to sound--the BRFs and the cut-off distances work 
together to consider how these two factors, respectively, can predict 
marine mammal responses. Separately, given the extensive development 
process, it is unreasonable to revise and update the criteria and risk 
functions every time a new paper is published, though both NMFS and the 
Navy review and consider the implications of any new papers as they 
arise. Further, we note that NMFS and the Navy are currently 
considering new information in development of the next version (Phase 
IV) of the Navy's Criteria and Thresholds for U.S. Navy Acoustic and 
Explosive Effects Analysis.
    We disagree with the commenter's assertion that the 10 km cutoff 
distance is unsubstantiated, as we disagreed with the Marine Mammal 
Commission's initial comment, cited by CBD in its letter. The 
derivation of the behavioral response functions and associated cutoff 
distances is provided in the Navy's Criteria and Thresholds for U.S. 
Navy Acoustic and Explosive Effects Analysis (Phase III) technical 
report (Navy 2017a). The consideration of proximity (distance cutoff) 
was part of criteria developed in consultation with NMFS and was 
applied within the Navy's BRF. Cutoffs representing the distances 
beyond which the potential of significant behavioral responses were 
considered to be unlikely were used in conducting analysis for ICEX22. 
The Navy's BRF applied within these distances is an appropriate method 
for providing a realistic (but still conservative where some 
uncertainties exist) estimate of impact and potential take for these 
activities.
    Regarding consideration of pinniped reactions at received levels of 
less than or equal to 140 dB re 1 [mu]Pa, the current criteria (Phase 
III) use a slightly modified version of the Southall et al. (2007) 
severity scaling when considering pinniped reactions, including to 
exposures less than 140 dB SPL (sound pressure level), given that 
Southall et al. (2007) did not meet the criteria for inclusion (i.e., 
received level paired with observation of response). Pinniped data 
included in the Phase III BRFs did include reactions in grey seals 
slightly below 140 dB SPL, but these were captive studies conducted in 
a pool where the sound sources were within a few meters of the animal 
(G[ouml]tz and Janik 2011). Therefore, the context (i.e., proximity to 
the source) was likely an important factor mediating the seals 
reactions. Significant behavioral reactions in pinnipeds have not been 
observed beyond a few kilometers. The Navy's Criteria and Thresholds 
for U.S. Navy Acoustic and Explosive Effects Analysis (Phase III), 
summarizes grey seal reactions on pg. 61, and individual experimental 
trials from G[ouml]tz and Janik (2011) are summarized in Appendix B, 
starting on pg. 157, including several significant behavioral 
reactions. G[ouml]tz (2008) and Gotz and Janik (2010) were not included 
in development of the criteria because they did not include

[[Page 7807]]

observations specific enough to pair received levels with behavioral 
reactions.
    Comment 6: CBD stated that NMFS discounts impacts from aircraft or 
incorrectly assumes complete mitigation. CBD asserted that some 
pinnipeds are equally susceptible to noise in air as in water (Kastak 
et al. 2007). Southall (2019) provides in-air PTS (154 dB SEL) and TTS 
(134 dB SEL) thresholds for pinnipeds. Ice seals are sensitive to out-
of-water noise, including hauling out in response to aircraft noise 
(Bradford et al. 1999).
    Response: While NMFS agrees with the commenter that in some 
situations in-air noise can result in take of marine mammals, NMFS 
assessed the impacts of aircraft for the Navy's ICEX22 activities and 
does not expect aircraft noise from this project to take marine mammals 
given the required mitigation included in the IHA. Born et al. (1999) 
analyzed ``escape responses'' (i.e., hauled out ringed seals entering 
the water) from an aircraft and a helicopter flying at an altitude of 
150 m (164 yd). The results of the study indicated that if the aircraft 
do not approach the seals closer than 500 m (547 yd) at that altitude, 
the risk of flushing the seals into the water can be greatly reduced. 
In a separate paper, Bradford and Weller (2005) noted that helicopter 
presence resulted in flushing of most of the hauled out seals during 
observations, though they did not note specific distances of the 
helicopter at which flushing occurred.
    The final IHA requires that fixed wing aircraft must operate at the 
highest altitudes practicable taking into account safety of personnel, 
meteorological conditions, and need to support safe operations of a 
drifting ice camp. Aircraft must not reduce altitude if a seal is 
observed on the ice. In general, cruising elevation must be 305 m 
(1,000 ft) or higher. This altitude is significantly higher than the 
150 m (164 yd) aircraft and helicopter altitudes analyzed in Born et 
al. (1999). Unmanned Aircraft Systems (UASs) must maintain a minimum 
altitude of at least 15.2 m (50 ft) above the ice. They must not be 
used to track or follow marine mammals. Further, helicopter flights 
must use prescribed transit corridors when traveling to or from Prudhoe 
Bay and the ice camp. Helicopters must not hover or circle above marine 
mammals or within 457 m (1,500 ft) of marine mammals, and aircraft must 
maintain a minimum separation distance of 1.6 km (1 mi) from groups of 
5 or more seals and must not land on ice within 800 m (0.5 mi) of 
hauled-out seals. These measures are expected to prevent the take of 
marine mammals from aircraft and UASs, and the commenter has not 
offered data that suggests otherwise.
    Comment 7: CBD asserted that the proposed mitigation fails to 
ensure the least practicable adverse impact. First, the proposed IHA 
does not include any mitigation for the sonar. There are several 
additional mitigation measures that would reduce the potential for 
harassment of marine mammals including:
    <bullet> Placing a cap on the overall use of sonar to ensure the 
lowest level of marine mammal disturbance;
    <bullet> Requiring that activities conclude before April when 
bowhead whales migrate into the area;
    <bullet> Requiring passive acoustic and/or thermal monitoring and 
restricting sonar in the presence of marine mammals or aggregations of 
marine mammals; and
    <bullet> Limiting the number of aircraft transits and prohibiting 
dipping sonar.
    Response: The commenter appears to have overlooked required 
mitigation measures for sonar that were included in the proposed IHA 
and are included in the final IHA. The mitigation measures ``for 
activities involving acoustic transmissions'' described in the proposed 
and final IHAs apply to sonar. These measures include the following: 
(1) Personnel must begin passive acoustic monitoring (PAM) for 
vocalizing marine mammals 15 minutes prior to the start of activities 
involving active acoustic transmissions from submarines and exercise 
weapons. (2) Personnel must delay active acoustic transmissions and 
exercise weapon launches if a marine mammal is detected during pre-
activity PAM and must shutdown active acoustic transmissions if a 
marine mammal is detected during acoustic transmissions. (3) Personnel 
must not restart acoustic transmissions or exercise weapon launches 
until 15 minutes have passed with no marine mammal detections.
    Regarding the commenter's recommendation that NMFS place a ``cap'' 
on the overall use of sonar to ensure the lowest level of marine mammal 
disturbance, the Navy must use the amount of sonar required to 
successfully conduct the activity, and such a limit set by NMFS is, 
therefore, not practicable. Unlike incidental take authorizations in 
other Navy training and testing areas that include limits on sonar use 
in certain areas during certain times, such as in the Navy's Northwest 
Training and Testing Area, ICEX22 is limited in duration and scope, and 
there are no known Biologically Important Areas or other factors that 
warrant a time/area restriction in the ICEX22 Navy Activity Study Area.
    Regarding the commenter's recommendation that NMFS require that 
activities conclude before April when bowhead whales migrate into the 
area, NMFS has, by default, required that the Navy's activities that 
have the potential to harass marine mammals conclude by the end of 
April, as that is when the IHA expires. Please see Comment 11 for 
additional information regarding NMFS' conclusion that bowhead whales 
are not likely to be in the Navy Activity Study Area before the end of 
April, and therefore will not be taken during ICEX22.
    Regarding the commenter's recommendation that NMFS require PAM and/
or thermal monitoring and restrict sonar use in the presence of marine 
mammals or aggregations of marine mammals, NMFS had already included 
such measures in the proposed IHA, and has included them in this final 
IHA, as described in the first paragraph of this comment response.
    Regarding the commenter's recommendation that NMFS limit the number 
of aircraft transits and prohibit dipping sonar, the Navy is already 
minimizing the number of aircraft transits to only those that are 
necessary for successful completion of the ICEX22 activity, and 
therefore, an additional limit set by NMFS is not practicable. (See 
Sections 2.1.3 (Prudhoe Bay) and 2.2.2 (Aircraft) of the 2022 ICEX EA/
OEA for additional information regarding planned aircraft use in 
ICEX22.) Dipping sonar is not a part of the Navy's planned ICEX22 
activities (see the Navy's ICEX22 IHA application), nor has the Navy 
utilized dipping sonar in 2018 or 2020 ICEX activities. Therefore, a 
prohibition on dipping sonar is not warranted.
    Comment 8: CBD stated that the mitigation for ice camps, while 
good, could be more robust to ensure that ringed seals are not 
disturbed. For example, there are not any mitigation measures designed 
for ringed seals that may be present in the ice camp area or for 
pupping ice seals.
    Response: The mitigation measures included in the proposed IHA, and 
this final IHA, include measures to avoid impacts to ringed seal 
subnivean lairs, which is where ringed seals would be expected to occur 
in the area if they were out of the water during the February to April 
timeframe.
    It is unclear what the commenter means by its suggested inclusion 
of ``mitigation measures designed for ringed seals that may be present 
in the ice camp area or for pupping ice seals'' and the commenter has 
not suggested

[[Page 7808]]

any additional measures that would satisfy this vague recommendation, 
beyond what NMFS has already included in the proposed and final IHA. As 
discussed in the response to Comment 3, given the expected density of 
ringed seal lairs in the Ice Camp Study Area, the relative footprint of 
the Navy's planned ice camp (2 km\2\), the lack of previous ringed seal 
observations on the ice during ICEX activities, and mitigation 
requirements that require the Navy to construct the ice camp and runway 
on first-year or multi-year ice without pressure ridges and require 
personnel to avoid areas of deep snow drift or pressure ridges, ringed 
seal pups are not anticipated to occur in the vicinity of the ice camp 
at the commencement of and during ICEX22 activities.
    Comment 9: CBD stated that the monitoring provisions are woefully 
insufficient by only requiring reporting of dead and injured seals, and 
stated that there should, at minimum, also be monitoring and reporting 
of harassment of any marine mammals.
    Response: The Navy is required to conduct far more monitoring and 
reporting than just reporting observations of injured and dead marine 
mammals. As stated in the proposed IHA, and in this final IHA, in 
addition to reporting observations of injured or dead marine mammals, 
the Navy is required to submit an exercise monitoring report which will 
include the number of marine mammals sighted, by species, and any other 
available information about the sighting(s) such as date, time, and 
approximate location (latitude and longitude). The Navy must also 
report data regarding sonar use and the number of shutdowns during 
ICEX22 activities in the Atlantic Fleet Training and Testing (AFTT) 
Letter of Authorization 2023 annual classified report. The Navy is also 
required to analyze any declassified underwater recordings collected 
during ICEX22 for marine mammal vocalizations and report that 
information to NMFS, including the types and natures of sounds heard 
(e.g., clicks, whistles, creaks, burst pulses, continuous, sporadic, 
strength of signal) and the species or taxonomic group (if 
determinable). This information will also be submitted to NMFS with the 
2023 annual AFTT declassified monitoring report. Further, as stated in 
the Monitoring and Reporting section of this notice, the Navy is also 
now exploring the potential of implementing an environmental DNA (eDNA) 
study on ice seals.
    Comment 10: CBD stated that there cannot be a renewal of this 
authorization because the renewal process violates section 101(a)(5)(D) 
of the MMPA. Also, this authorization should not be eligible for a 
renewal because the activities are supposed to finish in April, and 
thus are far less than would need to be continued next year. The 
activities must be concluded on time to avoid additional take of 
bowhead whales and other protected species. Additionally, CBD stated 
that the Navy only conducts ICEX every 2 or 3 years; and therefore, 
even if the activity is similar next time, it is not eligible for a 
one-year renewal.
    Response: In prior responses to comments about IHA renewals (e.g., 
84 FR 52464; October 02, 2019 and 85 FR 53342, August 28, 2020), NMFS 
has explained how the renewal process, as implemented, is consistent 
with the statutory requirements contained in section 101(a)(5)(D) of 
the MMPA, provides additional efficiencies beyond the use of 
abbreviated notices and, further, promotes NMFS' goals of improving 
conservation of marine mammals and increasing efficiency in the MMPA 
compliance process. Therefore, we intend to continue implementing the 
renewal process.
    Regarding the commenters assertion that this particular activity 
does not qualify for a renewal IHA, NMFS considers renewals on a case-
by-case basis, and would consider the eligibility of a request for a 
renewal if and when such a request is received from the Navy.
    Regarding the commenter's statement that the activities must be 
concluded on time to avoid take of bowhead whales and other protected 
species, the Navy's authorization, which authorizes take of ringed 
seals only, expires April 30, 2022. Therefore, activities which may 
result in the take of marine mammals must be completed by that date. 
The final IHA explicitly prohibits the take of any other species of 
marine mammal, other than ringed seals as authorized. Please also refer 
to the response to Comment 11, which describes why bowhead whales are 
not expected to occur in the Study Area during the Navy's ICEX22 
activities.
    Comment 11: CBD stated that the determination that there will be no 
take of other marine mammals within NMFS' jurisdiction seems 
insufficiently supported. NMFS acknowledges that bearded seals are 
present in the area during the project timeframe; however, it discounts 
the potential impact on bearded seals because they are unlikely to be 
near the ice camp or where submarine activities would be conducted. 
This fails to consider that noise from sonar can travel great 
distances, and that even if a bearded seal does not dive to 800 m or 
would prefer other habitat with benthic organisms, this does not 
preclude harassment impacts from more distant submarine activities.
    CBD also stated that endangered bowhead whales migrate through the 
area and may be present during the end of the ICEX activities.
    Response: Regarding bearded seals, although acoustic data indicate 
that some bearded seals remain in the Beaufort Sea year round 
(MacIntyre et al. 2013, 2015; Jones et al. 2014), satellite tagging 
data (Boveng and Cameron 2013; ADF&G 2017) show that large numbers of 
bearded seals move south in fall/winter with the advancing ice edge to 
spend the winter in the Bering Sea, confirming previous visual 
observations (Burns and Frost 1979; Frost et al. 2008; Cameron and 
Boveng 2009). The southward movement of bearded seals in the fall means 
that very few individuals are expected to occur along the Beaufort Sea 
continental shelf in February through April, the timeframe ICEX22 
activities. The northward spring migration through the Bering Strait, 
begins in mid-April (Burns and Frost 1979).
    In the event some bearded seals were to remain in the Beaufort Sea 
during the season when ICEX22 activities will occur, the most probable 
area in which bearded seals might occur during winter months is along 
the continental shelf. Bearded seals feed extensively on benthic 
invertebrates (e.g., clams, gastropods, crabs, shrimp, bottom-dwelling 
fish; Quakenbush et al. 2011; Cameron et al. 2010) and are typically 
found in water depths of 200 m (656 ft) or less (Burns 1970). The 
Bureau of Ocean Energy Management (BOEM) conducted an aerial survey 
from June through October that covered the shallow Beaufort and Chukchi 
Sea shelf waters, and observed bearded seals from Point Barrow to the 
border of Canada (Clarke et al. 2015). The farthest from shore that 
bearded seals were observed was the waters of the continental slope 
(though this study was conducted outside of the ICEX22 time frame). The 
Navy anticipates that the ice camp will be established 185-370 km (100-
200 nmi) north of Prudhoe Bay in water depths of 800 m (2,625 ft) or 
more. The continental shelf near Prudhoe Bay is approximately 55 nmi 
(100 km) wide. Therefore, even if the ice camp were established at the 
closest estimated distance (100 nmi from Prudhoe Bay), it would still 
be approximately 45 nmi (83 km) distant from habitat potentially 
occupied by bearded seals. Empirical evidence has not shown responses 
to

[[Page 7809]]

sonar that would constitute take beyond a few km from an acoustic 
source, and therefore, NMFS and the Navy conservatively set a distance 
cutoff of 10 km. Regardless of the source level at that distance, take 
is not estimated to occur beyond 10 km from the source. Although 
bearded seals are found 20 to 100 nmi (37 to 185 km) offshore during 
spring (Simpkins et al. 2003, Bengtson et al. 2005), during the winter 
we expect bearded seals to select habitats where food is abundant and 
easily accessible to minimize the energy required to forage and 
maximize energy reserves in preparation for whelping, lactation, 
mating, and molting. Bearded seals are not known to dive to 800 m to 
forage and it is highly unlikely that they would occur near the ice 
camp or where the research activities will be conducted. This 
conclusion is supported by the fact that the Navy did not visually 
observe or acoustically detect bearded seals during required PAM during 
the 2020 ice exercises.
    Regarding bowhead whales, NMFS provided a detailed description of 
their migratory route and the typical timing of their northward 
migration in the notice of the proposed IHA (86 FR 70451; December 10, 
2021). As explained in that notice, bowhead whales are unlikely to 
occur in the Navy Activity Study Area between February and April, as 
they spend winter (December to March) in the northern Bering Sea and 
southern Chukchi Sea, and migrate north through the Chukchi Sea and 
Beaufort Sea during April and May (Muto et al. 2021). On their spring 
migration, the earliest that bowhead whales reach Point Hope in the 
Chukchi Sea, well south of Point Barrow, is late March to mid-April 
(Braham et al. 1980). Although the ice camp location is not known with 
certainty, the distance between Point Barrow and the closest edge of 
the Ice Camp Study Area is over 200 km. The distance between Point 
Barrow and the closest edge of the Navy Activity Study Area is over 50 
km, and the distance between Point Barrow and Point Hope is an 
additional 525 km (straight line distance); accordingly, bowhead whales 
are unlikely to occur in the ICEX22 Study Area before ICEX22 activities 
conclude. NMFS is not aware of, nor has the commenter provided, 
information that suggests that bowhead whales would be present in the 
Navy Activity Study Area during the planned ICEX22 activities.
    Comment 12: CBD stated that NMFS should better analyze the 
potential impacts on subsistence harvest. CBD asserted that because 
serious injury and mortality are already over PBR, authorization of 
additional take from sources other than subsistence harvest may reduce 
availability of ice seals. NMFS must either provide more data and 
support its assumption that the population estimate for the stock is 
wrong or provide a more robust analysis of the potential impacts on 
subsistence harvest.
    Response: See the response to Comment 1 for discussion of PBR. 
Further, NMFS' unmitigable adverse impact determination is not based 
upon the abundance estimate for the Alaska stock of ringed seals.
    Impacts to marine mammals from the specified activity will mostly 
include limited, temporary behavioral disturbances of ringed seals; 
however, some TTS is also anticipated. No Level A harassment (injury), 
serious injury, or mortality of marine mammals is expected or 
authorized, and the activities are not expected to have any impacts on 
the reproduction or survival of any animals. NMFS' determination is 
based on the anticipated effects to marine mammals (take by Level B 
harassment only), the short-term, temporary nature of the ICEX22 
activities which will occur outside of the primary subsistence hunting 
seas, and the distance offshore from known subsistence hunting areas. 
(The Study Area boundary is seaward of subsistence hunting areas, 
approximately 50 km from shore at the closest point, though exercises 
will occur farther offshore.) Further, the Navy plans to provide 
advance public notice to local residents and other users of the Prudhoe 
Bay region of Navy activities and measures used to reduce impacts on 
resources. This includes notification to local Alaska Natives who hunt 
marine mammals for subsistence. If any Alaska Natives express concerns 
regarding project impacts to subsistence hunting of marine mammals, the 
Navy will further communicate with the concerned individuals or 
community. The Navy will provide project information and clarification 
of any mitigation measures that may reduce impacts to marine mammals. 
While it seems clear that ringed seals generally are an important 
subsistence species for Alaska Natives, no concerns specific to this 
activity have been expressed so far. Apart from clarifying that the 
unmitigable adverse impact determination is not based upon the 
abundance estimate for the Alaska stock of ringed seals, it is unclear 
what the commenter would consider a ``better'' analysis of the 
potential impacts on subsistence harvest.
    Comment 13: CBD asserted that because of the impacts on threatened 
and endangered species and their critical habitat, the Finding of No 
Significant Impact is arbitrary, and the Navy should have prepared an 
Environmental Impact Statement.
    Response: The Navy has drafted the EA to analyze the full scope of 
ICEX22 activities, given that conducting the ICEX22 activities is their 
proposed action. NMFS' authority is limited to the issuance, if 
appropriate, of an IHA for the take of marine mammals that it manages. 
However, NMFS concurs with the analysis presented in the 2022 ICEX EA. 
Regarding issuance of an IHA to the Navy, given the scope of the 
impacts of the Navy's activity on marine mammals that NMFS manages, 
NMFS finds that the 2022 ICEX EA fully supports NMFS' Finding of No 
Significant Impact, which was made following finalization of the EA. 
Given that the comment is directed at the Navy and NMFS' role in 
managing the resources analyzed in the EA is limited, NMFS provided 
this comment to the Navy to consider for the final EA.
    In response, the Navy has explained that in accordance with 
requirements of the National Environmental Policy Act (NEPA) and 
Executive Order 12114, the Navy analyzed all potential impacts 
resulting from the proposed action and found that the short-term 
effects, the absence of injury or mortality, and the planned mitigation 
implementation resulted in no significant impact or significant harm to 
the resources. The Navy's consultations with NMFS and U.S. Fish and 
Wildlife Service also support these findings and therefore, an EIS is 
not required.
    Separately, of note, as stated in the Endangered Species Act 
section of this notice, NMFS' Alaska Regional Office Protected 
Resources Division issued a Biological Opinion on January 31, 2022, 
which concluded that the Navy's activities and NMFS' issuance of an IHA 
are not likely to jeopardize the continued existence of the Arctic 
stock of ringed seals. As described in the notice of the proposed IHA, 
NMFS has proposed Designation of Critical Habitat for the Arctic 
Subspecies of the Ringed Seal (86 FR 1452; January 8, 2021). However, 
this proposed critical habitat has not been finalized.
    Comment 14: CBD stated that the 2022 ICEX EA fails to analyze any 
alternatives beyond the no-action alternative. CBD stated that NMFS 
should consider an alternative that incorporates additional mitigation 
measures such as limits on sonar, time restrictions, passive acoustic 
and/or thermal monitoring, and limits on aircraft.
    Response: As discussed in the response to Comment 13, NMFS

[[Page 7810]]

considers the analysis in the 2022 ICEX EA, including its discussion of 
alternatives, sufficient to support a Finding of No Significant Impact 
with respect to the issuance of an IHA. As discussed in NMFS' response 
to Comment 7, the proposed and final IHAs require that the Navy conduct 
PAM for marine mammals, and that the Navy delay or shut down active 
acoustic transmissions if a marine mammal is detected during pre-
activity PAM or during acoustic transmissions, respectively. These 
measures are considered as part of the proposed action in the EA. 
However, an alternative that incorporated the additional mitigation 
measures identified by the commenter would not be viable. The limits on 
aircraft and sonar recommended by the commenter for inclusion in a new 
alternative in the 2022 ICEX EA cannot be implemented by the Navy for 
the reasons described in the response to Comment 7. It is unclear what 
the commenter means by its suggested time restrictions, however, the 
Navy has selected the February to April time period due to the 
environmental conditions required to successfully complete the 
exercises.
    Comment 15: CBD stated that NMFS, which is charged with protecting 
marine mammals, cannot adopt the Navy's purpose and need for military 
activities such as evaluating the employment and tactics of submarine 
operability in Arctic conditions.
    Response: Section 1.2 of the 2022 ICEX Draft EA and the Final EA 
state NMFS' purpose and need, which are separate from that of the Navy. 
As stated in Section 1.2, NMFS' purpose is to evaluate the Navy's 
Proposed Action pursuant to NMFS' authority under the MMPA, and to make 
a determination whether to issue an IHA, including any conditions or 
mitigation measures along with monitoring and reporting requirements 
needed to meet the statutory requirements of the MMPA. As also stated 
in Section 1.2, the need for NMFS' proposed action is to consider the 
impacts of the Navy's activities on marine mammals and meet NMFS' 
obligations under the MMPA.
    Comment 16: CBD states that the EA fails to adequately examine 
important environmental effects, and that it suffers from some of the 
same flaws as the negligible impact determination. For example, it 
underestimates the potential impact of the activities on ringed seals, 
the impacts of sonar, and discounts all impacts on wildlife other than 
ice seals. The EA assumes that avoidance and displacement of ringed 
seals will mitigate impacts, but instead they displace ringed seals 
from preferred habitat and constitute a taking.
    Response: Please see Comment 1 for NMFS' response to the alleged 
``flaws'' identified by the commenter in the negligible impact 
determination, and see Comment 3 for NMFS' response to the commenter's 
concerns regarding potential avoidance and displacement of ringed 
seals. Those responses also address analysis of the impacts of the 
Navy's activity on ringed seals, including impacts of sonar and the 
potential for avoidance and displacement of ringed seals in the EA. 
Otherwise, NMFS has provided this comment to the Navy to consider as it 
relates to the impacts of sonar and impacts on wildlife other than ice 
seals for which NMFS does not have management authority.
    In response, the Navy has explained that the 2022 ICEX EA analyzed 
all resources and all potential affects as a result of its Proposed 
Action. The Navy consulted with NMFS regarding impacts to bearded seals 
and ringed seals, and the U.S. Fish and Wildlife Service regarding 
polar bears. The effects of sonar were analyzed using the best 
available science and the Navy conducted extensive modeling to 
determine potential effects, which resulted in the Navy requesting an 
IHA from NMFS.
    Comment 17: CBD stated that it finds the assumption that polar 
bears will not be harassed, displaced, or disturbed by the proposed 
activities particularly troubling. CBD referenced instances of 
disturbance of polar bears by snow machine noise, and raised concerns 
about impacts of noise on denning polar bears.
    Response: Polar bears are managed by the U.S. Fish and Wildlife 
Service rather than NMFS. Therefore, NMFS has provided this comment to 
the Navy to consider for the final EA.
    Comment 18: CBD states that the EA fails to adequately consider the 
impacts of climate change both on the proposed activities as well as 
the additional pressure that the activities exert on arctic wildlife 
that is already threatened by climate change. The commenter stated that 
the primary threat facing ringed seals is habitat alteration flowing 
from climate change due to its effects on sea ice and snow cover, which 
ringed seals depend on for pupping, nursing, molting, and resting 
(Andersen, Kovacs and Lydersen, N.D.; Boucher 2018; Boucher 2019; Crain 
et al. 2021; Crawford et al. 2019; Fauchald et al. 2017; Ferguson et 
al. 2017, 2020; Hezel et al. 2012; Hamilton et al. 2015, 2018, 2019; 
Hamilton, Kovacs and Lydersen 2019; Harwood et al. 2020; Karpovich, 
Horstmann and Polasek 2020; Lone et al. 2019; Lydersen et al. 2017; 
Martinez-Bakker et al. 2013; Reimer et al. 2019; Ritchie 2018; Von 
Duyke et al. 2020; Yurkowski, David J., et al. 2019). The commenter 
states that ocean warming and acidification resulting from increased 
CO<INF>2</INF> emissions also alter prey populations and other 
ecosystem dynamics important to the listed ringed seals (77 FR 76708, 
December 28, 2012; Andersen, Kovacs and Lydersen, N.D.; Beltran et al. 
2016; Boucher 2018; Hamilton et al. 2016; Lowther et al. 2017; Matley, 
Fisk and Dick 2015; Wang et al. 2016a, 2016b; Young and Ferguson 2013, 
2014).CBD further stated that the proposed activities deepen the 
imperilment of climate-threatened ice seals, polar bears, and other 
wildlife, and that the cursory cumulative impacts analysis lacks any 
substance or discussion of other actions in the area such as oil and 
gas, shipping, and fishing activities (77 FR 76712, December 28, 2012; 
Andersen, Kovacs and Lydersen, N.D.; Lomac-Macnair, Andrade and Esteves 
2019; Muto 2021; Siddon, Zador and Hunt Jr. 2020; Von Duyke et al. 
2020; Yurkowski et al. 2019).
    Response: NMFS has considered CBD's comments regarding the impacts 
of climate change on ringed seals, and additional analysis has been 
added to the final 2022 ICEX EA/OEA. As stated in the final 2022 ICEX 
EA/OEA, the habitat of Arctic species has been altered by the warming 
climate, and scientific consensus projects continued and accelerated 
warming in the foreseeable future. This continued warming will decrease 
sea ice and snow cover that seals and polar bears rely on throughout 
their lifecycle. Ringed seals use sea ice for resting, whelping, and 
molting, while polar bears primarily use it for hunting, mating, and 
maternity denning. Climate change has caused a reduction in the 
distribution, abundance, and body condition of Arctic species. 
Additionally, ocean warming and acidification alter prey populations 
that marine mammal species rely on, and increase competition with 
subarctic species (Laidre et al. 2008). Although climate change is a 
continuing threat to Arctic species, activities conducted during ICEX 
will have an inconsequential additional impact since they are 
temporary, and planned mitigation measures are expected to reduce 
impacts to protected species during the activities.

[[Page 7811]]

Changes From the Proposed IHA to Final IHA

    NMFS slightly modified the IHA start date. The proposed IHA 
reflected a start date of February 1, 2022, while the final IHA becomes 
effective February 4, 2022.

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. 
Additional information regarding population trends and threats may be 
found in NMFS' 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, and summarizes information related to the population or 
stock, including regulatory status under the MMPA and the Endangered 
Species Act (ESA; 16 U.S.C. 1531 et seq.) and potential biological 
removal (PBR), where known. For taxonomy, we follow Committee on 
Taxonomy (2021). 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 from anthropogenic sources are 
included in Table 1 as gross indicators of the status of the species 
and other threats. That said, in this case for the Arctic stock of 
ringed seals and as explained in footnotes 6 and 7 of Table 1, the lack 
of complete population information significantly impacts the usefulness 
of PBR in considering the status of the stock, as explained below.
    Marine mammal abundance estimates 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's U.S. Alaska SARs 
(Muto et al. 2021). All values presented in Table 1 are the most recent 
available at the time of publication and are available in the 2020 
Alaska SAR (Muto et al. 2021) and draft 2021 Alaska SAR (available 
online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports). However, for 
the same reason noted above and as described in footnotes 4 and 5 of 
Table 1, the lack of complete population information for the Arctic 
stock of ringed seals impacts the usefulness of these numbers in 
considering the impacts of the anticipated take on the stock.

                    Table 1--Species That Spatially Co-Occur With the Activity to the Degree That Take Is Reasonably Likely To Occur
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         ESA/MMPA status;    Stock abundance (CV;
             Common name                  Scientific name               Stock             Strategic (Y/N)      Nmin; most recent       PBR     Annual M/
                                                                                                \1\          abundance survey) \2\               SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
    Ringed seal.....................  Pusa hispida...........  Arctic.................  T/D;Y               171,418 4 5, (N/A,      \6\ 4,755  \7\ 6,459
                                                                                                             158,507 4 5; 2013).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). 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.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\3\ This value, found in NMFS' SARs, represents annual levels of human-caused mortality (M) plus serious injury (SI) from all sources combined (e.g.,
  commercial fisheries, ship strike).
\4\ These estimates reflect the Bering Sea population only, as reliable abundance estimates for the Chukchi Sea and Beaufort Sea are not available.
\5\ This is expected to be an underestimate of ringed seals in the Bering Sea, as the estimate was not adjusted for seals in the water at the time of
  the surveys, nor does it include ringed seals in the shorefast ice zone.
\6\ The PBR value for this stock is based on a partial stock abundance estimate, and is therefore an underestimate for the full stock.
\7\ The majority of the M/SI for this stock (6,454 of 6,459 animals) is a result of the Alaska Native subsistence harvest. While M/SI appears to exceed
  PBR, given that the reported PBR is based on a partial stock abundance estimate, and is therefore an underestimate for the full stock, M/SI likely
  does not exceed PBR.

    As indicated in Table 1, ringed seals (with one managed stock) 
temporally and spatially co-occur with the activity to the degree that 
take is reasonably likely to occur, and we have authorized such take. A 
detailed description of the Arctic stock of ringed seals, including 
brief introductions to the species and stock, available information 
regarding population trends and threats, information regarding local 
occurrence, proposed ESA-designated Critical Habitat, and information 
regarding a current UME were provided in the Federal Register notice 
for the proposed IHA (86 FR 70451; December 10, 2021). Since that time, 
we are not aware of any changes in the status of the Arctic stock of 
ringed seals, and 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.
    As described in footnotes 4, 5, 6, and 7 of Table 1, the lack of 
complete population information significantly impacts the usefulness of 
abundance estimates and PBR for this stock. The PBR for the Alaska 
stock of ringed seals is based upon a minimum population estimate that 
is expected to be an underestimate, as it is an estimate for just a 
portion of the stock's range, and that estimate was also not corrected 
for seals in the water or shorefast ice zone during the survey. 
Therefore, the minimum population estimate (and best population 
estimate) and PBR for the Alaska stock of ringed seals are negatively 
biased (i.e., underestimates). These metrics are considered as gross 
indicators of the stock status; however, an accurate abundance estimate 
and PBR for the entire stock is not necessary to make the negligible 
impact determination. For the full discussion on this issue, see our 
response to Comment 1.

[[Page 7812]]

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. Current data indicate that 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) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). 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           150 Hz to 160 kHz.
 (dolphins, toothed whales, beaked
 whales, bottlenose whales).
High-frequency (HF) cetaceans (true    275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 cephalorhynchid, Lagenorhynchus
 cruciger and L. australis).
Phocid pinnipeds (PW) (underwater)     50 Hz to 86 kHz.
 (true seals).
Otariid pinnipeds (OW) (underwater)    60 Hz to 39 kHz.
 (sea 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 ~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 and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
Only ringed seals (a phocid pinniped species) have the reasonable 
potential to co-occur with the planned ICEX22 activities.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The underwater noise from the Navy's submarine training and testing 
activities has the potential to result in behavioral harassment of 
marine mammals in the vicinity of the ICEX22 Study Area. The notice of 
the proposed IHA (86 FR 70451; December 10, 2021) included a discussion 
of the effects of anthropogenic noise on marine mammals and the 
potential effects of underwater noise from the Navy's activities on 
marine mammals and their habitat. That information and analysis is 
incorporated by reference into this final IHA determination and is not 
repeated here; please refer to the notice of proposed IHA (86 FR 70451; 
December 10, 2021).

Estimated Take

    This section provides the number of incidental takes estimated to 
occur, which will inform NMFS' analysis for the negligible impact 
determination.
    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 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 for the Navy's ICEX22 activities are by Level B 
harassment only, in the form of disruption of behavioral patterns and/
or TTS for individual marine mammals resulting from exposure to 
acoustic transmissions. Based on the nature of the activity, Level A 
harassment is neither anticipated nor authorized. As described 
previously, no mortality or serious injury is anticipated or authorized 
for this activity. Below we describe how the incidental take is 
estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which the best available science indicates marine 
mammals will be behaviorally disturbed 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. For this IHA, the Navy employed a 
sophisticated model known as the Navy Acoustic Effects Model (NAEMO) to 
assess the estimated impacts of underwater sound.

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 disturbed (equated to 
Level B harassment) or to incur permanent threshold shift (PTS) of some 
degree (equated to Level A harassment).
    Level B Harassment by behavioral disturbance for non-explosive 
sources--In coordination with NMFS, the Navy developed behavioral 
thresholds to support environmental analyses for the Navy's testing and 
training military readiness activities utilizing active sonar sources; 
these behavioral harassment thresholds are used here to evaluate the 
potential effects of the active sonar components of the

[[Page 7813]]

specified activities. The behavioral response of a marine mammal to an 
anthropogenic sound will depend on the frequency, duration, temporal 
pattern, and amplitude of the sound as well as the animal's prior 
experience with the sound and the context in which the sound is 
encountered (i.e., what the animal is doing at the time of the 
exposure). The distance from the sound source and whether it is 
perceived as approaching or moving away can also affect the way an 
animal responds to a sound (Wartzok et al. 2003). For marine mammals, a 
review of responses to anthropogenic sound was first conducted by 
Richardson et al. (1995). Reviews by Nowacek et al. (2007) and Southall 
et al. (2007) address studies conducted since 1995 and focus on 
observations where the received sound level of the exposed marine 
mammal(s) was known or could be estimated.
    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. 
2013a; Houser et al. 2013b). Moretti et al. (2014) published a beaked 
whale dose-response curve based on PAM of beaked whales during Navy 
training activity at Atlantic Underwater Test and Evaluation Center 
during actual Anti-Submarine Warfare exercises. This new information 
necessitated the update of the behavioral response criteria for the 
Navy's environmental analyses.
    Southall et al. (2007) 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). 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.
    The Navy's Phase III pinniped behavioral threshold was updated 
based on controlled exposure experiments on the following captive 
animals: Hooded seal, gray seal, and California sea lion (G[ouml]tz et 
al. 2010; Houser et al. 2013a; Kvadsheim et al. 2010). Overall exposure 
levels were 110-170 dB re 1 [mu]Pa for hooded seals, 140-180 dB re 1 
[mu]Pa for gray seals, and 125-185 dB re 1 [mu]Pa for California sea 
lions; responses occurred at received levels ranging from 125 to 185 dB 
re 1 [mu]Pa. However, the means of the response data were between 159 
and 170 dB re 1 [mu]Pa. 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. Because these 
data represent a dose-response type relationship between received level 
and a response, and because the means were all tightly clustered, the 
Bayesian biphasic Behavioral Response Function for pinnipeds most 
closely resembles a traditional sigmoidal dose-response function at the 
upper received levels and has a 50 percent probability of response at 
166 dB re 1 [mu]Pa. Additionally, to account for proximity to the 
source discussed above and based on the best scientific information, a 
conservative distance of 10 km is used beyond which exposures would not 
constitute a take under the military readiness definition of Level B 
harassment. The Navy proposed, and NMFS concurs with, the use of this 
dose response function to predict behavioral harassment of pinnipeds 
for this activity.
    Level A harassment and Level B harassment by threshold shift for 
non-explosive sources--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).
    These thresholds were developed by compiling the best available 
science and soliciting input multiple times from both the public and 
peer reviewers to inform the final product. 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.
    The Navy's PTS/TTS analysis begins with mathematical modeling to 
predict the sound transmission patterns from Navy sources, including 
sonar. These data are then coupled with marine species distribution and 
abundance data to determine the sound levels likely to be received by 
various marine species. These criteria and thresholds are applied to 
estimate specific effects that animals exposed to Navy-generated sound 
may experience. For weighting function derivation, the most critical 
data required are TTS onset exposure levels as a function of exposure 
frequency. These values can be estimated from published literature by 
examining TTS as a function of sound exposure level (SEL) for various 
frequencies.
    To estimate TTS onset values, only TTS data from behavioral hearing 
tests were used. To determine TTS onset for each subject, the amount of 
TTS observed after exposures with different SPLs and durations were 
combined to create a single TTS growth curve as a function of SEL. The 
use of (cumulative) SEL is a simplifying assumption to accommodate 
sounds of various SPLs, durations, and duty cycles. This is referred to 
as an ``equal energy'' approach, since SEL is related to the energy of 
the sound and this approach assumes exposures with equal SEL result in 
equal effects, regardless of the duration or duty cycle of the sound. 
It is well known that the equal energy rule will over-estimate the 
effects of intermittent noise, since the quiet periods between noise 
exposures will allow some recovery of hearing compared to noise that is 
continuously present with the same total SEL (Ward 1997). For 
continuous exposures with the same SEL but different durations, the 
exposure with the longer duration will also tend to produce more TTS 
(Finneran et al. 2010; Kastak et al. 2007; Mooney et al. 2009a).
    As in previous acoustic effects analysis (Finneran and Jenkins 
2012; Southall et al. 2007), the shape of the PTS exposure function for 
each species group is assumed to be identical to the TTS exposure 
function for each group. A difference of 20 dB between TTS onset and 
PTS onset is used for all marine mammals including pinnipeds. This is 
based on estimates of exposure levels actually required for PTS (i.e., 
40

[[Page 7814]]

dB of TTS) from the marine mammal TTS growth curves, which show 
differences of 13 to 37 dB between TTS and PTS onset in marine mammals. 
Details regarding these criteria and thresholds can be found in NMFS' 
Technical Guidance (NMFS 2018).
    Table 3 below provides the weighted criteria and thresholds used in 
this analysis for estimating quantitative acoustic exposures of marine 
mammals from the specified activities.

  Table 3--Acoustic Thresholds Identifying the Onset of Behavioral Disturbance, TTS, and PTS for Non-Impulsive
                                                Sound Sources \1\
----------------------------------------------------------------------------------------------------------------
                                                                                  Physiological criteria
                                                          Behavioral     ---------------------------------------
    Functional hearing group            Species            criteria        TTS threshold SEL   PTS threshold SEL
                                                                              (weighted)          (weighted)
----------------------------------------------------------------------------------------------------------------
Phocid Pinnipeds (Underwater)...  Ringed seal.......  Pinniped Dose       181 dB SEL          201 dB SEL
                                                       Response Function   cumulative.         cumulative.
                                                       \2\.
----------------------------------------------------------------------------------------------------------------
\1\ 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.
\2\ See Figure 6-1 in the Navy's IHA application.
Note: SEL thresholds in dB re: 1 [mu]Pa\2\s

Quantitative Modeling

    The Navy performed a quantitative analysis to estimate the number 
of marine mammals that could be harassed by the underwater acoustic 
transmissions during the specified activities. Inputs to the 
quantitative analysis included marine mammal density estimates, marine 
mammal depth occurrence distributions (U.S Department of the Navy, 
2017), oceanographic and environmental data, marine mammal hearing 
data, and criteria and thresholds for levels of potential effects.
    The density estimate used to estimate take is derived from habitat-
based modeling by Kaschner et al. (2006) and Kaschner (2004). The area 
of the Arctic where the specified activities will occur (185-370 km 
(100-200 nmi) north of Prudhoe Bay, Alaska) has not been surveyed in a 
manner that supports quantifiable density estimation of marine mammals. 
In the absence of empirical survey data, information on known or 
inferred associations between marine habitat features and (the 
likelihood of) the presence of specific species have been used to 
predict densities using model-based approaches. These habitat 
suitability models include relative environmental suitability (RES) 
models. Habitat suitability models can be used to understand the 
possible extent and relative expected concentration of a marine species 
distribution. These models are derived from an assessment of the 
species occurrence in association with evaluated environmental 
explanatory variables that results in defining the RES suitability of a 
given environment. A fitted model that quantitatively describes the 
relationship of occurrence with the environmental variables can be used 
to estimate unknown occurrence in conjunction with known habitat 
suitability. Abundance can thus be estimated for each RES value based 
on the values of the environmental variables, providing a means to 
estimate density for areas that have not been surveyed. Use of the 
Kaschner's RES model resulted in a value of 0.3957 ringed seals per 
km\2\ in the cold season (defined as December through May).
    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 
planned sonars, 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 a marine mammal 
exceeds the thresholds for effects.
    The Navy developed a set of software tools and compiled data for 
estimating acoustic effects on marine mammals without consideration of 
behavioral avoidance or Navy's standard mitigations (Lookouts, safety 
zones, avoidance zones, etc.). These tools and data sets are integral 
components of 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 
or testing 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 animat could be impacted during each independent 
scenario or 24-hour period. In a few instances for the modeling of the 
specified activities here, although the activities themselves all occur 
within the ICEX22 Study Area, sound may propagate beyond the boundary 
of the ICEX22 Study Area. Any exposures occurring outside the boundary 
of the study area are counted as if they occurred within the ICEX22 
Study Area boundary. NAEMO provides the initial estimated impacts on 
marine species with a static horizontal distribution.
    There are limitations to the data used in the acoustic effects 
model, and the results must be interpreted within this context. While 
the most accurate data and input assumptions have been used in the 
modeling, when there is a lack of definitive data to support an aspect 
of the modeling, modeling assumptions believed to overestimate the 
number of exposures have been chosen:
    <bullet> Animats are modeled as being underwater, stationary, and 
facing the source and therefore always predicted to receive the maximum 
sound level (i.e., no porpoising or pinnipeds' heads above water);
    <bullet> Animats do not move horizontally (but do change their 
position vertically within the water column), which may

[[Page 7815]]

overestimate physiological effects such as hearing loss, especially for 
slow moving or stationary sound sources in the model;
    <bullet> Animats are stationary horizontally and therefore do not 
avoid the sound source, unlike in the wild where animals will most 
often avoid exposures at higher sound levels, especially those 
exposures that may result in PTS;
    <bullet> Multiple exposures within any 24-hour period are 
considered one continuous exposure for the purposes of calculating the 
temporary or permanent hearing loss, because there are not sufficient 
data to estimate a hearing recovery function for the time between 
exposures; and
    <bullet> Mitigation measures that will be implemented are not 
considered in the model. In reality, sound-producing activities will be 
reduced, stopped, or delayed if marine mammals are detected by 
submarines via PAM.
    Because of these inherent model limitations and simplifications, 
model-estimated results must be further analyzed, considering such 
factors as the range to specific effects, avoidance, and typically the 
likelihood of successfully implementing mitigation measures. This 
analysis uses a number of factors in addition to the acoustic model 
results to predict effects on marine mammals.
    For non-impulsive sources, NAEMO calculates the sound pressure 
level (SPL) and sound exposure level (SEL) for each active emission 
during an event. This is done by taking the following factors into 
account over the propagation paths: Bathymetric relief and bottom 
types, sound speed, and attenuation contributors such as absorption, 
bottom loss, and surface loss. Platforms such as a ship using one or 
more sound sources are modeled in accordance with relevant vehicle 
dynamics and time durations by moving them across an area whose size is 
representative of the training event's operational area. Table 4 
provides range to effects for active acoustic sources planned for 
ICEX22 to phocid pinniped-specific criteria. Phocids within these 
ranges will be predicted to receive the associated effect. Range to 
effects is important information in not only predicting acoustic 
impacts, but also in verifying the accuracy of model results against 
real-world situations and determining adequate mitigation ranges to 
avoid higher level effects, especially physiological effects, to marine 
mammals.

                 Table 4--Range to Behavioral Disturbance, TTS, and PTS in the ICEX22 Study Area
----------------------------------------------------------------------------------------------------------------
                                                                             Range to effects  (m)
                                                              --------------------------------------------------
                       Source/exercise                            Behavioral
                                                                 disturbance          TTS              PTS
----------------------------------------------------------------------------------------------------------------
Submarine Exercise...........................................      \a\ 10,000            3,025              130
----------------------------------------------------------------------------------------------------------------
\a\ Empirical evidence has not shown responses to sonar that would constitute take beyond a few km from an
  acoustic source, which is why NMFS and the Navy conservatively set a distance cutoff of 10 km. Regardless of
  the source level at that distance, take is not estimated to occur beyond 10 km from the source.

    As discussed above, within NAEMO, animats do not move horizontally 
or react in any way to avoid sound. Furthermore, mitigation measures 
that are implemented during training or testing activities that reduce 
the likelihood of physiological impacts are not considered in 
quantitative analysis. Therefore, the current model overestimates 
acoustic impacts, especially physiological impacts near the sound 
source. The behavioral criteria used as a part of this analysis 
acknowledges that a behavioral reaction is likely to occur at levels 
below those required to cause hearing loss (TTS or PTS). At close 
ranges and high sound levels approaching those that could cause PTS, 
avoidance of the area immediately around the sound source is the 
assumed behavioral response for most cases.
    In previous environmental analyses, the Navy has implemented 
analytical factors to account for avoidance behavior and the 
implementation of mitigation measures. The application of avoidance and 
mitigation factors has only been applied to model-estimated PTS 
exposures given the short distance over which PTS is estimated. Given 
that no PTS exposures were estimated during the modeling process for 
these specified activities, the implementation of avoidance and 
mitigation factors were not included in this analysis.
    Table 5 shows the exposures expected for ringed seals based on 
NAEMO modeled results.

                Table 5--Quantitative Modeling Results of Potential Exposures for ICEX Activities
----------------------------------------------------------------------------------------------------------------
                                                     Level B harassment
                                             ----------------------------------     Level A
                   Species                       Behavioral                        harassment         Total
                                                disturbance          TTS
----------------------------------------------------------------------------------------------------------------
Ringed seal.................................           3,976              910                0            4,886
----------------------------------------------------------------------------------------------------------------

    During monitoring for the 2018 IHA covering similar military 
readiness activities in the ICEX22 Study Area, the Navy did not 
visually observe or acoustically detect any marine mammals (U.S. Navy, 
2018). During monitoring for the 2020 IHA covering similar military 
readiness activities in the ICEX22 Study Area, the Navy also did not 
visually observe any marine mammals (U.S. Navy, 2020). Acoustic 
monitoring associated with the 2020 IHA did not detect any discernible 
marine mammal vocalizations (Henderson et al. 2021). The monitoring 
report states that ``there were a few very faint sounds that could have 
been [ringed seal] barks or yelps.'' However, these were likely not 
from ringed seals, given that ringed seal vocalizations are generally 
produced in series (Jones et al. 2014). Henderson et al. (2021) expect 
that these sounds were likely ice-associated or perhaps anthropogenic.

Mitigation Measures

    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

[[Page 7816]]

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, we 
carefully consider 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) and 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.

Mitigation for Marine Mammals and Their Habitat

    Appropriate personnel (including civilian personnel) involved in 
mitigation and training or testing activity reporting under the 
specified activities must complete Arctic Environmental and Safety 
Awareness Training. Modules include: Arctic Species Awareness and 
Mitigations, Environmental Considerations, Hazardous Materials 
Management, and General Safety.
    Further, the following general mitigation measures are required to 
prevent incidental take of ringed seals on the ice floe associated with 
the ice camp (further explanation of certain mitigation measures is 
provided in parentheses following the measure):
    <bullet> The ice camp and runway must be established on first-year 
and multi-year ice without pressure ridges. (This will minimize 
physical impacts to subnivean lairs and impacts to sea ice habitat 
suitable for lairs.);
    <bullet> Ice camp deployment must begin no later than mid-February 
2022, and be gradual, with activity increasing over the first 5 days. 
Camp deployment must be completed by March 15, 2022. (Given that 
mitigation measures require that the ice camp and runway be established 
on first-year or multi-year ice without pressure ridges where ringed 
seals tend to build their lairs, as well as the average ringed seal 
lair density in the area, and the relative footprint of the Navy's 
planned ice camp (2 km\2\), it is extremely unlikely that a ringed seal 
would build a lair in the vicinity of the ice camp. Additionally, based 
on the best available science, Arctic ringed seal whelping is not 
expected to occur prior to mid-March, and therefore, construction of 
the ice camp will be completed prior to whelping in the area of ICEX22. 
Further, as noted above, ringed seal lairs are not expected to occur in 
the ice camp study area, and therefore, NMFS does not expect ringed 
seals to relocate pups due to human disturbance from ice camp 
activities, including construction.);
    <bullet> Personnel on all on-ice vehicles must observe for marine 
and terrestrial animals;
    <bullet> Snowmobiles must follow established routes, when 
available. On-ice vehicles must not be used to follow any animal, with 
the exception of actively deterring polar bears if the situation 
requires;
    <bullet> Personnel on foot and operating on-ice vehicles must avoid 
areas of deep snowdrifts near pressure ridges. (These areas are 
preferred areas for subnivean lair development.);
    <bullet> Personnel must maintain a 100 m (328 ft) avoidance 
distance from all observed marine mammals; and
    <bullet> All material (e.g., tents, unused food, excess fuel) and 
wastes (e.g., solid waste, hazardous waste) must be removed from the 
ice floe upon completion of ICEX22 activities.
    The following mitigation measures are required for activities 
involving acoustic transmissions (further explanation of certain 
mitigation measures is provided in parentheses following the measure):
    <bullet> Personnel must begin passive acoustic monitoring (PAM) for 
vocalizing marine mammals 15 minutes prior to the start of activities 
involving active acoustic transmissions from submarines and exercise 
weapons.
    <bullet> Personnel must delay active acoustic transmissions and 
exercise weapon launches if a marine mammal is detected during pre-
activity PAM and must shutdown active acoustic transmissions if a 
marine mammal is detected during acoustic transmissions.
    <bullet> Personnel must not restart acoustic transmissions or 
exercise weapon launches until 15 minutes have passed with no marine 
mammal detections.
    Ramp up procedures for acoustic transmissions are not required as 
the Navy determined, and NMFS concurs, that they would result in 
impacts on military readiness and on the realism of training that would 
be impracticable.
    The following mitigation measures are required for aircraft 
activities to prevent incidental take of marine mammals due to the 
presence of aircraft and associated noise.
    <bullet> Fixed wing aircraft must operate at the highest altitudes 
practicable taking into account safety of personnel, meteorological 
conditions, and need to support safe operations of a drifting ice camp. 
Aircraft must not reduce altitude if a seal is observed on the ice. In 
general, cruising elevation must be 305 m (1,000 ft) or higher.
    <bullet> Unmanned Aircraft Systems (UASs) must maintain a minimum 
altitude of at least 15.2 m (50 ft) above the ice. They must not be 
used to track or follow marine mammals.
    <bullet> Helicopter flights must use prescribed transit corridors 
when traveling to or from Prudhoe Bay and the ice camp. Helicopters 
must not hover or circle above marine mammals or within 457 m (1,500 
ft) of marine mammals.
    <bullet> Aircraft must maintain a minimum separation distance of 
1.6 km (1 mi) from groups of 5 or more seals.
    <bullet> Aircraft must not land on ice within 800 m (0.5 mi) of 
hauled-out seals.
    Based on our evaluation of the Navy's proposed mitigation measures, 
as well as other measures considered by NMFS, NMFS has determined that 
the required 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, and 
areas of similar significance.

[[Page 7817]]

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) require requests for 
authorizations to include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
area of the specified activity. 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:
    <bullet> Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density).
    <bullet> 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 action; or (4) biological or 
behavioral context of exposure (e.g., age, calving, or feeding areas).
    <bullet> Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors.
    <bullet> How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks.
    <bullet> Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat).
    <bullet> Mitigation and monitoring effectiveness.
    The Navy has coordinated with NMFS to develop an overarching 
program, the Integrated Comprehensive Monitoring Program (ICMP), 
intended to coordinate marine species monitoring efforts across all 
regions and to allocate the most appropriate level and type of effort 
for each range complex based on a set of standardized objectives, and 
in acknowledgement of regional expertise and resource availability. The 
ICMP was created in direct response to Navy requirements established in 
various MMPA regulations and ESA consultations. 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 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 by the Navy's activities. In 
comparison, ICEX is a short duration exercise that occurs approximately 
every other year. Due to the location and expeditionary nature of the 
ice camp, the number of personnel onsite is extremely limited and is 
constrained by the requirement to be able to evacuate all personnel in 
a single day with small planes. As such, the Navy asserts that a 
dedicated ICMP monitoring project is not feasible as it would require 
additional personnel and equipment, and NMFS concurs. However, the Navy 
is exploring the potential of implementing an environmental DNA (eDNA) 
study on ice seals.
    Nonetheless, the Navy must conduct the following monitoring and 
reporting under the IHA. Ice camp personnel must generally monitor for 
marine mammals in the vicinity of the ice camp and record all 
observations of marine mammals, regardless of distance from the ice 
camp, as well as the additional data indicated below. Additionally, 
Navy personnel must conduct PAM during all active sonar use. Ice camp 
personnel must also maintain an awareness of the surrounding 
environment and document any observed marine mammals.
    In addition, the Navy is required to provide NMFS with a draft 
exercise monitoring report within 90 days of the conclusion of the 
specified activity. 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. The report, at minimum, must include:
    <bullet> Marine mammal monitoring effort (dedicated hours);
    <bullet> Ice camp activities occurring during each monitoring 
period (e.g., construction, demobilization, safety watch, field 
parties);
    <bullet> Number of marine mammals detected;
    <bullet> Upon observation of a marine mammal, record the following 
information:
    [cir] Environmental conditions when animal was observed, including 
relevant weather conditions such as cloud cover, snow, sun glare, and 
overall visibility, and estimated observable distance;
    [cir] Lookout location and ice camp activity at time of sighting 
(or location and activity of personnel who made observation, if 
observed outside of designated monitoring periods);
    [cir] Time and approximate location of sighting;
    [cir] Identification of the animal(s) (e.g., seal, or 
unidentified), also noting any identifying features;
    [cir] Distance and location of each observed marine mammal relative 
to the ice camp location for each sighting;
    [cir] Estimated number of animals (min/max/best estimate);
    [cir] Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as 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).
    Also, all sonar usage will be collected via the Navy's Sonar 
Positional Reporting System database. The Navy is required to provide 
data regarding sonar use and the number of shutdowns during ICEX22 
activities in the Atlantic Fleet Training and Testing (AFTT) Letter of 
Authorization 2023 annual classified report. The Navy is also required 
to analyze any declassified underwater recordings collected during 
ICEX22 for marine mammal vocalizations and report that information to 
NMFS, including the types and nature of sounds heard (e.g., clicks, 
whistles, creaks, burst pulses, continuous, sporadic, strength of 
signal) and the species or taxonomic group (if determinable). This 
information will also be submitted to NMFS with the 2023 annual AFTT 
declassified monitoring report.
    Finally, in the event that personnel discover an injured or dead 
marine mammal, personnel must report the incident to the Office of 
Protected Resources (OPR), NMFS and to the Alaska regional stranding 
network as soon as feasible. The report must include the following 
information:
    <bullet> Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    <bullet> Species identification (if known) or description of the 
animal(s) involved;

[[Page 7818]]

    <bullet> Condition of the animal(s) (including carcass condition if 
the animal is dead);
    <bullet> Observed behaviors of the animal(s), if alive;
    <bullet> If available, photographs or video footage of the 
animal(s); and
    <bullet> General circumstances under which the animal(s) was 
discovered (e.g., during submarine activities, observed on ice floe, or 
by transiting aircraft).

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 responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS' implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    Underwater acoustic transmissions associated with ICEX22, as 
outlined previously, have the potential to result in Level B harassment 
of ringed seals in the form of TTS and behavioral disturbance. No take 
by Level A harassment, serious injury, or mortality are anticipated to 
result from this activity. Further, at close ranges and high sound 
levels approaching those that could cause PTS, seals will likely avoid 
the area immediately around the sound source.
    NMFS estimates 910 takes of ringed seals by TTS from the submarine 
activities. TTS is a temporary impairment of hearing and can last from 
minutes or hours to days (in cases of strong TTS). In many cases, 
however, hearing sensitivity recovers rapidly after exposure to the 
sound ends. This activity has the potential to result in only minor 
levels of TTS, and hearing sensitivity of affected animals would be 
expected to recover quickly. Though TTS may occur as indicated, the 
overall fitness of the impacted individuals is unlikely to be affected 
given the temporary nature of TTS and the minor levels of TTS expected 
from these activities. Negative impacts on the reproduction or survival 
of affected ringed seals as well as impacts on the stock are not 
anticipated.
    Effects on individuals that are taken by Level B harassment by 
behavioral disturbance could include alteration of dive behavior, 
alteration of foraging behavior, effects to breathing, 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 and mitigation using PAM, 
which will limit exposure to active acoustic sources. Most likely, 
individuals will be temporarily displaced by moving away from the sound 
source. As described in the Acoustic Impacts section of the notice of 
proposed IHA (86 FR 70451; December 10, 2021), seals exposed to non-
impulsive sources with a received sound pressure level within the range 
of calculated exposures, (142-193 dB re 1 [mu]Pa), have been shown to 
change their behavior by modifying diving activity and avoidance of the 
sound source (G[ouml]tz et al. 2010; Kvadsheim et al. 2010). Although a 
minor change to a behavior may occur as a result of exposure to the 
sound sources associated with the specified activity, these changes 
will be within the normal range of behaviors for the animal (e.g., the 
use of a breathing hole further from the source, rather than one closer 
to the source). Thus, even repeated Level B harassment of some small 
subset of the overall stock is unlikely to result in any significant 
realized decrease in fitness for the affected individuals, and will not 
result in any adverse impact on reproduction or survival of affected 
individuals or to the stock as a whole.
    The Navy's planned activities are localized and of relatively short 
duration. While the total ICEX22 Study Area is large, the Navy expects 
that most activities will occur within the Ice Camp Study Area in 
relatively close proximity to the ice camp. The larger Navy Activity 
Study Area depicts the range where submarines may maneuver during the 
exercise. The ice camp will be in existence for up to six weeks with 
acoustic transmission occurring intermittently over approximately 4 
weeks.
    The project is not expected to have significant adverse effects on 
marine mammal habitat. The project activities are limited in time and 
will not modify physical marine mammal habitat. While the activities 
may cause some fish to leave a specific area ensonified by acoustic 
transmissions, temporarily impacting marine mammals' foraging 
opportunities, these fish will likely return to the affected area. As 
such, the impacts to marine mammal habitat are not expected to cause 
significant or long-term negative consequences.
    For on-ice activity, Level A harassment, Level B harassment, 
serious injury, and mortality are not anticipated, given the nature of 
the activities, the lack of previous ringed seal observations, and the 
mitigation measures NMFS has included in the IHA. The ringed seal 
pupping season on the ice lasts for five to nine weeks during late 
winter and spring. As discussed in the Potential Effects of Specified 
Activities on Marine Mammals and Their Habitat section, March 1 is 
generally expected to be the onset of ice seal lairing season. The ice 
camp and runway will be established on first-year or multi-year ice 
without pressure ridges, as ringed seals tend to build their lairs near 
pressure ridges. Ice camp deployment will begin no later than mid-
February, and be gradual, with activity increasing over the first 5 
days. Ice camp deployment will be completed by March 15, before the 
pupping season. Displacement of seal lair construction or relocation to 
existing lairs outside of the ice camp area is unlikely, given the low 
average density of lairs (the average ringed seal lair density in the 
vicinity of Prudhoe Bay, Alaska is 1.58 lairs per km\2\ (Table 3 of the 
notice of the proposed IHA; 86 FR 70451, December 10, 2021)), the 
relative footprint of the Navy's planned ice camp (2 km\2\), the lack 
of previous ringed seal observations on the ice during ICEX activities, 
and mitigation requirements that require the Navy to construct the ice 
camp and runway on first-year or multi-year ice without pressure ridges 
and require personnel to avoid areas of deep snow drift or pressure 
ridges. Given that mitigation measures require that the ice camp and 
runway be established on first-year or multi-year ice without pressure 
ridges, where ringed seals tend to build their lairs, it is extremely 
unlikely that a ringed seal would build a lair in the vicinity of the 
ice camp.

[[Page 7819]]

This measure, in combination with the other mitigation measures 
required for operation of the ice camp are expected to avoid impacts to 
the construction and use of ringed seal subnivean lairs, particularly 
given the already low average density of lairs, as described above. 
Given that ringed seal lairs are not expected to occur in the ice camp 
study area, NMFS does not expect ringed seals to relocate pups due to 
human disturbance from ice camp activities.
    Additional mitigation measures will also prevent damage to and 
disturbance of ringed seals and their lairs that could otherwise result 
from on-ice activities. Personnel on on-ice vehicles will observe for 
marine mammals, and will follow established routes when available, to 
avoid potential damage to or disturbance of lairs. Personnel on foot 
and operating on-ice vehicles will avoid deep snow drifts near pressure 
ridges, also to avoid potential damage to or disturbance of lairs. 
Further, personnel will maintain a 100 m (328 ft) distance from all 
observed marine mammals to avoid disturbing the animals due to the 
personnel's presence. Implementation of these measures will also 
prevent ringed seal lairs from being crushed or damaged during ICEX22 
activities.
    There is an ongoing UME for ice seals, including ringed seals. 
Elevated strandings have occurred in the Bering and Chukchi Seas since 
June 2018. As of November 17, 2021, 95 ringed seal strandings have 
occurred, which is well below the partial abundance estimate of 171,418 
ringed seals in the Arctic stock. The take authorized here does not 
provide a concern for any of these populations when considered in the 
context of these UMEs, especially given that the anticipated Level B 
harassment is unlikely to affect the reproduction or survival of any 
individuals. In addition, the ICEX22 Study Area is in the Arctic Ocean, 
well north and east of the primary area where seals have stranded along 
the western coast of Alaska (see map of strandings at: https://www.fisheries.noaa.gov/alaska/marine-life-distress/2018-2021-ice-seal-unusual-mortality-event-alaska). No Level A harassment, serious injury, 
or mortality is expected or authorized here, and take by Level B 
harassment of ringed seals will be reduced to the level of least 
practicable impact through the incorporation of mitigation measures. As 
such, the authorized takes by Level B harassment of ringed seals are 
not expected to exacerbate or compound the ongoing UME.
    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 the species or stock through 
effects on annual rates of recruitment or survival:
    <bullet> No Level A harassment (injury), serious injury, or 
mortality is anticipated or authorized;
    <bullet> Impacts will be limited to Level B harassment, primarily 
in the form of behavioral disturbance that results in minor changes in 
behavior;
    <bullet> TTS is expected to affect only a limited number of animals 
(approximately 0.5 percent of the partial stock abundance described in 
Table 1) and TTS is expected to be minor and short term;
    <bullet> The number of authorized takes is low relative to the 
estimated abundances of the affected stock, even given the extent to 
which abundance is significantly underestimated;
    <bullet> Submarine training and testing activities will occur over 
only 4 weeks of the total 6-week activity period;
    <bullet> There will be no loss or modification of ringed seal 
habitat and minimal, temporary impacts on prey;
    <bullet> Physical impacts to ringed seal subnivean lairs will be 
avoided; and
    <bullet> Mitigation requirements for ice camp activities will 
prevent impacts to ringed seals during the pupping season.
    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 required monitoring and 
mitigation measures, NMFS finds that the total marine mammal take from 
the specified activity will have a negligible impact on the Arctic 
stock of ringed seals.

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 marine mammal species or stocks by 
Alaska 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.
    Impacts to marine mammals from the specified activity will mostly 
include limited, temporary behavioral disturbances of ringed seals; 
however, some TTS is also anticipated. No Level A harassment (injury), 
serious injury, or mortality of marine mammals is expected or 
authorized, and the activities are not expected to have any impacts on 
reproductive or survival rates of any marine mammal species.
    The specified activity and associated harassment of ringed seals 
are not expected to impact marine mammals in numbers or locations 
sufficient to reduce their availability for subsistence harvest given 
the short-term, temporary nature of the activities, and the distance 
offshore from known subsistence hunting areas. The specified activity 
will occur for a brief period of time outside of the primary 
subsistence hunting season, and though seals are harvested for 
subsistence uses off the North Slope of Alaska, the ICEX22 Study Area 
is seaward of known subsistence hunting areas. (The Study Area boundary 
is approximately 50 km from shore at the closest point, though 
exercises will occur farther offshore.)
    The Navy plans to provide advance public notice to local residents 
and other users of the Prudhoe Bay region of Navy activities and 
measures used to reduce impacts on resources. This includes 
notification to local Alaska Natives who hunt marine mammals for 
subsistence. If any Alaska Natives express concerns regarding project 
impacts to subsistence hunting of marine mammals, the Navy will further 
communicate with the concerned individuals or community. The Navy will 
provide project information and clarification of the mitigation 
measures that will reduce impacts to marine mammals.
    Based on the description and location of the specified activity, 
and the required mitigation and monitoring measures, NMFS has 
determined that there will not be an unmitigable adverse impact on 
subsistence uses from the Navy's specified activities.

National Environmental Policy Act

    In compliance with the National Environmental Policy Act of 1969 
(42 U.S.C. 4321 et seq.), as implemented by the regulations published 
by the Council on Environmental Quality (40 CFR parts 1500-1508), the 
Navy prepared an Environmental Assessment (EA) to consider the direct, 
indirect, and cumulative effects to the human environment resulting 
from the ICEX22 project. The Navy's EA was made available for public 
comment at https://www.nepa.navy.mil/icex/ for 28 days beginning 
November 24, 2021. The public comment period was reopened

[[Page 7820]]

from January 5 to January 28 due to a delay in publication of a notice 
to the public in the Arctic Sounder newspaper. In the notice of 
proposed IHA (86 FR 70451; December 10, 2021), NMFS described its plan 
to adopt the Navy's EA, provided our independent evaluation of the 
document found that it includes adequate information analyzing the 
effects on the human environment of issuing the IHA. In compliance with 
NEPA and the CEQ regulations, as well as NOAA Administrative Order 216-
6, NMFS has reviewed the Navy's EA and determined it to be sufficient. 
NMFS adopted that EA and signed a Finding of No Significant Impact 
(FONSI) on February 4, 2022.

Endangered Species Act

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 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 NMFS' Alaska 
Regional Office (AKRO).
    The NMFS Office of Protected Resources (OPR) is authorizing take of 
ringed seals, which are listed under the ESA. The NMFS Alaska Regional 
Office Protected Resources Division issued a Biological Opinion on 
January 31, 2022, which concluded that the Navy's activities and NMFS' 
issuance of an IHA are not likely to jeopardize the continued existence 
of the Arctic stock of ringed seals. There is no ESA designated 
critical habitat for ringed seals.

Authorization

    NMFS has issued an IHA to the Navy for conducting submarine 
training and testing activities in the ICEX22 Study Area of the Arctic 
Ocean beginning in February 2022 that includes the previously explained 
mitigation, monitoring, and reporting requirements.

    Dated: February 4, 2022.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2022-02800 Filed 2-9-22; 8:45 am]
BILLING CODE 3510-22-P