Notice2026-01945
Marine Mammals; Proposed Incidental Harassment Authorization for Polar Bears in the Beaufort Sea and Arctic Ocean; Ice Exercise Activities by the U.S. Navy
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Published
February 2, 2026
Issuing agencies
Interior DepartmentFish and Wildlife Service
Abstract
We, the U.S. Fish and Wildlife Service, in response to a request under the Marine Mammal Protection Act of 1972 (MMPA), as amended, from the U.S. Department of the Navy (Navy), propose to authorize nonlethal, incidental take by harassment of Southern Beaufort Sea polar bears (Ursus maritimus) from February 18, 2026, to April 18, 2026. The applicant requested this authorization for take by harassment that may result from activities associated with the mobilization, operation, and demobilization of a temporary ice camp, aircraft transportation, submarine training and testing, and research in the Beaufort Sea and Arctic Ocean. This proposed authorization, if finalized, would be for up to six takes of polar bears by Level B harassment only. No take by injury or mortality is requested, expected, or proposed to be authorized. The Navy's activities are considered military readiness activities pursuant to the MMPA. We invite comments on the proposed incidental harassment authorization and the accompanying draft environmental assessment from the public, Tribes, and local, State, and Federal agencies.
Full Text
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<title>Federal Register, Volume 91 Issue 21 (Monday, February 2, 2026)</title>
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[Federal Register Volume 91, Number 21 (Monday, February 2, 2026)]
[Notices]
[Pages 4576-4593]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-01945]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
[Docket No. FWS-R7-ES-2025-1100; FXES111607MRG01-256-FF07CAMM00]
Marine Mammals; Proposed Incidental Harassment Authorization for
Polar Bears in the Beaufort Sea and Arctic Ocean; Ice Exercise
Activities by the U.S. Navy
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of receipt of application; proposed incidental
harassment authorization; draft environmental assessment; request for
comments.
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SUMMARY: We, the U.S. Fish and Wildlife Service, in response to a
request under the Marine Mammal Protection Act of 1972 (MMPA), as
amended, from the U.S. Department of the Navy (Navy), propose to
authorize nonlethal, incidental take by harassment of Southern Beaufort
Sea polar bears (Ursus maritimus) from February 18, 2026, to April 18,
2026. The applicant requested this authorization for take by harassment
that may result from activities associated with the mobilization,
operation, and demobilization of a temporary ice camp, aircraft
transportation, submarine training and testing, and research in the
Beaufort Sea and Arctic Ocean. This proposed authorization, if
finalized, would be for up to six takes of polar bears by Level B
harassment only. No take by injury or mortality is requested, expected,
or proposed to be authorized. The Navy's activities are considered
military readiness activities pursuant to the MMPA. We invite comments
on the proposed incidental harassment authorization and the
accompanying draft environmental assessment from the public, Tribes,
and local, State, and Federal agencies.
DATES: Comments must be received by March 4, 2026.
ADDRESSES:
Document Availability: You may view this proposed incidental
harassment authorization, the application package, supplemental
information, draft environmental assessment, and the list of references
cited herein at <a href="https://www.regulations.gov">https://www.regulations.gov</a> under Docket No. FWS-R7-ES-
2025-1100. Alternatively, you may request these documents from the
person listed under FOR FURTHER INFORMATION CONTACT.
Comment Submission: You may submit comments on the proposed
authorization by one of the following methods:
<bullet> Electronic submission: Go to the Federal eRulemaking
Portal: <a href="https://www.regulations.gov">https://www.regulations.gov</a>. In the Search box, enter FWS-R7-
ES-2025-1100, which is the docket number for this rulemaking action.
Then, click on the ``Search'' button. On the resulting page, in the
panel on the left side of the screen under the ``Document Type''
heading, check the Notice box to locate this document. You may submit a
comment by clicking on ``Comment.'' Comments must be submitted to
<a href="https://www.regulations.gov">https://www.regulations.gov</a> before 11:59 p.m. (Eastern Time) on the
date specified in DATES.
<bullet> U.S. mail: Public Comments Processing, Attn: Docket No.
FWS-R7-ES-2025-1100, U.S. Fish and Wildlife Service, MS: PRB (JAO/3W),
5275 Leesburg Pike, Falls Church, VA 22041-3803.
We request that you send comments only by the methods described
above. We will post all comments at <a href="https://www.regulations.gov">https://www.regulations.gov</a>. You
may request that we withhold personal identifying information from
public review; however, we cannot guarantee that we will be able to do
so. See Request for Public Comments for more information.
FOR FURTHER INFORMATION CONTACT: Stephanie Burgess, by email at
<a href="/cdn-cgi/l/email-protection#ee9cd98383839c8b899b828f9a819c97ae88999dc0898198"><span class="__cf_email__" data-cfemail="5c2e6b3131312e393b29303d28332e251c3a2b2f723b332a">[email protected]</span></a>, by telephone at 907-786-3800, or by U.S. mail
at U.S. Fish and Wildlife Service, MS 341, 1011 East Tudor Road,
Anchorage, AK 99503. Individuals in the United States who are deaf,
deafblind, hard of hearing, or have a speech disability may dial 711
(TTY, TDD, or TeleBraille) to access telecommunications relay services.
Individuals outside the United States should use the relay services
offered within their country to make international calls to the point-
of-contact in the United States.
SUPPLEMENTARY INFORMATION:
Background
Section 101(a)(5)(D) of the Marine Mammal Protection Act of 1972
(MMPA; 16 U.S.C. 1361 et seq.), as amended by the National Defense
Authorization Act for Fiscal Year 2004 (Pub. L. 108-136), authorizes
the Secretary of the Interior (Secretary) to allow, upon request for
military readiness activities, the incidental, but not intentional,
taking by harassment of marine mammals during a period of not more than
1 year. The Secretary has delegated authority for implementation of the
MMPA to the U.S. Fish and Wildlife Service (FWS or we). The FWS shall
allow this incidental taking by harassment if we make findings that the
total of such taking for the period of up to 1 year:
(1) will have a negligible impact on the species or stock; and
(2) will not have an unmitigable adverse impact on the availability
of the species or stock for taking for subsistence use by Alaska
Natives.
If the requisite findings are made, we issue an authorization that
sets forth the following, where applicable:
(a) permissible methods of taking;
(b) means of effecting the least practicable adverse impact on the
species or stock and its habitat and the availability of the species or
stock for subsistence uses; and
(c) requirements for monitoring and reporting of such taking by
harassment, including, in certain circumstances, requirements for the
independent peer review of proposed monitoring plans or other research
proposals.
The term ``take'' means to harass, hunt, capture, or kill, or
attempt to harass, hunt, capture, or kill, any marine mammal.
``Harassment'' for military readiness activities means any act that
injures or has the significant potential to injure a marine mammal or
marine mammal stock in the wild (the MMPA defines this as ``Level A
harassment''), or (ii) any act that disturbs or is likely to disturb a
marine mammal or marine mammal stock in the wild by causing disruption
of natural behavioral patterns, including, but not limited to,
migration, surfacing, nursing, breeding, feeding, or sheltering, to a
point where such behavioral patterns are abandoned or significantly
altered (the MMPA defines this as ``Level B harassment'').
The terms ``negligible impact'' and ``unmitigable adverse impact''
are defined in 50 CFR 18.27 (i.e., regulations governing small takes of
marine mammals incidental to specified activities) as follows:
``Negligible impact'' is 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. ``Unmitigable adverse impact''
means 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
[[Page 4577]]
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.
The term ``least practicable adverse impact'' is not defined in the
MMPA or its enacting regulations. In processing requests for IHAs, we
ensure the least practicable adverse impact by requiring mitigation
measures that are effective in reducing the impact of specified
activities, but not so restrictive as to make specified activities
unduly burdensome or impossible to undertake and complete. For IHAs
concerning military readiness activities, the MMPA requires
consideration of personnel safety, practicality of implementation, and
impact on the effectiveness of the military readiness activity. Before
making the required determination, the FWS consults with the Department
of Defense regarding personnel safety, practicality of implementation,
and impact on the effectiveness of the military readiness activity.
If the requisite findings are made, we shall issue an IHA, which
shall set forth the following, where applicable: (i) permissible
methods of taking; (ii) other means of effecting the least practicable
adverse 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 subsistence uses by coastal-dwelling Alaska Natives (if
applicable); and (iii) requirements for monitoring and reporting take
by harassment.
Summary of Request
On April 7, 2025, the FWS received a request from the U.S.
Department of the Navy (Navy) for authorization to take by nonlethal,
incidental harassment of Southern Beaufort Sea (SBS) stock polar bears
(Ursus maritimus) during a military readiness activity. The Navy's
request identified mobilization, operation, and demobilization of a
temporary ice camp, aircraft transportation, submarine training and
testing, and research activities in the Beaufort Sea and Arctic Ocean
for the period February 9, 2026 through April 9, 2026, as activities
that could incidentally take polar bears. Through a consultative
process, the FWS requested and the Navy provided additional information
on their proposed activities. The Navy submitted a revised request on
August 21, 2025. The FWS deemed the Navy's revised request adequate and
complete on August 21, 2025 (hereafter referred to as the ``Request'').
Description of Geographic Region and Specified Activities
The Navy's specified activities will occur in a geographic region
that extends north from Deadhorse, Alaska (70.19[deg] N), to the Arctic
Ocean basin near the North Pole (90.00[deg] N). A temporary ice camp
will be established approximately 185 kilometers (km) (100 nautical
miles [nm]) to 370 km (200 nm) north of Prudhoe Bay in the Beaufort
Sea. The exact location of the ice camp cannot be identified in advance
due to sea ice conditions required to establish the ice camp. Most
submarine training and testing activities will occur near the ice camp;
however, some submarine training and testing activities may occur
throughout the deep Arctic Ocean basin near the North Pole (figure 1
below).
[[Page 4578]]
[GRAPHIC] [TIFF OMITTED] TN02FE26.013
Figure 1--Geographic region of the U.S. Navy request for incidental
harassment authorization for polar bears in 2026 under the Marine
Mammal Protection Act.
The specified activities consist of mobilization, operation, and
demobilization of a temporary ice camp, aircraft transportation,
submarine training and testing, and research activities.
Reconnaissance Flights and Mobilization
In mid-February, reconnaissance flights originating from Deadhorse
will be conducted for a maximum of five days over an area approximately
70,374 square kilometers (km\2\) (27,172 square miles [mi\2\]) in the
Beaufort Sea to determine the location of the ice camp. Reconnaissance
flights using a single or twin otter fixed-wing aircraft will be flown
at altitudes between 305 meters (m) (1,000 feet [ft]) and 610 m (2,000
ft) for initial visual observations of the sea ice and descend to a
minimum altitude of 30 m (100 ft) during closer inspections of sea ice
conditions. Reconnaissance aircraft may also land on the sea ice to
allow personnel to further inspect the sea ice conditions on foot. A
maximum of 12 landings may occur during reconnaissance flights. After
the ice camp location is determined, the Navy will mobilize equipment,
supplies, and personnel from Deadhorse to the ice camp location. A
maximum of nine round trip flights are anticipated each day for
approximately six days during mobilization. Transportation flights will
be flown at a minimum altitude of 457 m (1,500 ft).
On-Ice Activities
Ice camp operations will occur for approximately four weeks between
mid-February and early-April, 2026. The ice camp will cover an area
approximately 2.0 km\2\ (0.8 mi\2\) and consist of 15 to 20 tents/
structures, a primary aircraft runway, a backup aircraft runway for
emergency use, and a helipad. A hydrophone array will be installed
around the ice camp. Hydrophones will be deployed on the ice and extend
to approximately 30 m (98 ft) below the ice. Recovery of the
hydrophones is planned; however, hydrophones may not be recovered if an
emergency demobilization of the ice camp occurs or if the hydrophones
are frozen in place and cannot be recovered.
Snowmobiles will be used to transport personnel and equipment to
support research activities around the ice camp. Snowmobiles will
travel a maximum of 3.2 km (2 mi) from the ice camp and cover an area
approximately 32.5 km\2\ (12.5 mi\2\). One snowmobile trip will occur
each day for the
[[Page 4579]]
approximate 4-week ice camp operation period. Four to six snowmobiles
will be used during the trips. Additionally, all-terrain tracked
vehicles may be used to support runway construction and expeditionary
forces within the ice camp area. The all-terrain tracked vehicles will
cover an area approximately 2.0 km\2\ (0.8 mi\2\). All-terrain tracked
vehicle trips may occur each day for the approximate 4-week ice camp
operation period. Unmanned on-ice vehicles (i.e., electric snowmobile)
may be tested around the ice camp and will always be within sight of
personnel during testing operations.
Aircraft Activities
Aircraft will transport equipment, supplies, and personnel from
Deadhorse to the ice camp and support research activities. One to three
round trip flights will occur each day during the approximate 4-week
ice camp operation period. A maximum of 6 flight hours is anticipated
for large military transport aircraft. These large military transport
aircraft may drop equipment and supplies by parachute at the ice camp.
A maximum of 648 flight hours is anticipated for small fixed-wing
aircraft. A maximum of 192 flight hours is anticipated for small
rotary-wing aircraft. Unmanned aerial systems (UAS) may be used for
testing and supporting research activities near the ice camp. Rotary-
wing UAS activities may cover an area approximately 203.4 km\2\ (78.5
mi\2\) around the ice camp and will always be within sight of personnel
during operations. A maximum of 36 flight hours is anticipated for UAS
activities.
In-Water Activities
In-water activities consist of submarine training and testing,
unmanned underwater vehicle use, water sample collection, deployment of
buoys, and use of underwater acoustic communication sources (e.g.,
echosounders, transducers). Submarine training and testing activities
generally consist of safety maneuvers and active sonar use to test the
performance of the equipment in an Arctic environment. Submarine-
launched torpedo exercises may be conducted, and the torpedoes used for
these exercises are non-explosive. Submarine training and testing
activities will not occur on or near the Continental Shelf. Submarines
may surface in first-year ice or near polynyas. The submarines are
anticipated to surface approximately five times near the ice camp
during the project period. Other in-water activities will be conducted
within the ice camp. These in-water activities will involve underwater
active acoustic transmissions. Information on the parameters for
scientific devices with active acoustics used during the Navy's
activities are provided in the Navy's Request.
Demobilization
Demobilization of the ice camp will likely occur in late March or
early April. All equipment, supplies, waste, and personnel will be
transported back to Deadhorse by aircraft. A maximum of nine round trip
flights are anticipated each day for approximately 7 days during
demobilization. Transportation flights will be flown at a minimum
altitude of 457 m (1,500 ft).
Description of Marine Mammals in the Geographic Region
Polar bears are the only marine mammal species under the FWS's
jurisdiction likely to be found within the geographic region. The vast
majority of the Navy's project activities will occur within the range
of the SBS polar bear stock. It is possible that the Navy's submarine
activities may occur within the range of the Chukchi/Bering Seas (CBS)
polar bear stock; however, these activities will occur under the sea
ice at depths greater than a polar bear can dive, and, therefore, we do
not anticipate any type of take to occur. Therefore, this proposed IHA
focuses on potential impacts to the SBS polar bear stock. Information
on the range, stocks, biology, and climate change impacts on polar
bears is included in supplemental information, which can be found as
described above in ADDRESSES.
Potential Impacts of the Specified Activities on Marine Mammals
Surface-Level Impacts on Polar Bears
Disturbance impacts on polar bears are influenced by the type,
duration, intensity, timing, and location of the source of disturbance.
Disturbance from the specified activities would originate primarily
from mobilization, operation, and demobilization of a temporary ice
camp, aircraft transportation, submarine training and testing, and
research activities. The noises, sights, and smells produced by these
activities could elicit variable responses from polar bears, ranging
from avoidance to attraction. When disturbed by noise, animals may
respond behaviorally by walking, running, or swimming away from a noise
source, or physiologically via increased heart rates or hormonal stress
responses (Harms et al. 1997; Tempel and Gutierrez 2003). However,
individual response to noise disturbance can be based on previous
interactions, sex, age, and maternal status (Anderson and Aars 2008;
Dyck and Baydack 2004). Noise and odors could also attract polar bears
to work areas. Attracting polar bears to these locations could result
in human--polar bear interactions, unintentional harassment,
intentional hazing, or possible lethal take in defense of human life.
This proposed IHA, if finalized, would authorize only the nonlethal,
incidental, unintentional take of polar bears that may result from the
specified activities and would require mitigation measures to manage
attractants in work areas and reduce the risk of human-polar bear
interactions.
Human-Polar Bear Interactions
Polar bear interaction plans, personnel training, attractants
management, and polar bear monitoring are mitigation measures used to
reduce human-polar bear interactions and minimize the risks to humans
and polar bears when interactions occur. Efficient management of
attractants (e.g., human food, garbage) can prevent polar bears from
associating humans with food, which lowers the risk of human-polar bear
interactions (Atwood and Wilder 2021). The Navy's polar bear
interaction plan details the policies and procedures that they will
implement to avoid attracting and interacting with polar bears and to
minimize potential impacts to polar bears. The interaction plan also
details how to respond to the presence of polar bears, the chain of
command and communication, and required training for personnel.
Information gained from monitoring polar bears near human activities
can be useful for better understanding polar bear distribution,
behavior, and interactions with humans. The Navy may use observers and
thermal cameras to monitor for polar bears. The mitigation measures
that will be implemented by the Navy will minimize the risk of possible
human-polar bear interactions during the specified activities.
Effects of Aircraft Overflights on Polar Bears
Polar bears experience increased noise and visual stimuli when
fixed-wing aircraft or rotary-wing aircraft fly above them, which may
elicit a biologically significant behavioral response. Sound
frequencies produced by aircraft will likely fall within the hearing
range of polar bears (Nachtigall et al. 2007) and will be audible to
polar bears during flyovers or when operating in proximity to polar
bears. Polar bears likely have acute hearing, with previous
sensitivities demonstrated between 1.4 and 22.5 kilohertz (kHz) (tests
were
[[Page 4580]]
limited to 22.5 kHz, Nachtigall et al. 2007). When exposed to high-
energy sound, this hearing range may become impaired temporarily
(called temporary threshold shift, or TTS) or permanently (called
permanent threshold shift, or PTS). A TTS is a noise-induced threshold
shift in hearing sensitivity that fully recovers over time (Finneran
2015). A PTS occurs when noise exposure causes damage to hair cells
within the inner ear system (Ketten 2012). Although the effects of PTS
are, by definition, permanent, PTS does not equate to total hearing
loss.
Sound exposure thresholds incorporate two metrics of exposure: the
peak level of instantaneous exposure likely to cause PTS, and the
cumulative sound exposure level (SEL<INF>CUM</INF>) during a 24-hour
period. They also include weighting adjustments for the sensitivity of
different species to varying frequencies. PTS-based injury criteria
were developed from theoretical extrapolation of observations of TTS
detected in lab settings during sound exposure trials (Finneran 2015).
Species-specific TTS and PTS thresholds have not been established for
polar bears at this time, but TTS and PTS thresholds have been
established for the general group ``other marine carnivores'', which
includes polar bears (Southall et al. 2019). Through a series of
systematic modeling procedures and extrapolations, Southall et al.
(2019) generated TTS and PTS thresholds for both in-air and underwater
sound (table 1, table 2 below).
Table 1--Temporary Threshold Shift (TTS) and Permanent Threshold Shift (PTS) Thresholds for In-Air Sounds
Established by Southall et al. (2019) Through Modeling and Extrapolation for ``Other Marine Carnivores'', Which
Includes Polar Bears
----------------------------------------------------------------------------------------------------------------
TTS PTS
-----------------------------------------------------------------------------------
Non-impulsive Impulsive Non-impulsive Impulsive
-----------------------------------------------------------------------------------
Peak
SELCUM SELCUM SPL SELCUM SELCUM Peak SPL
----------------------------------------------------------------------------------------------------------------
Air......................... 157 146 170 177 161 176
----------------------------------------------------------------------------------------------------------------
Note: Values are weighted for other marine carnivores' hearing thresholds and given in cumulative sound exposure
level (SELCUM dB re 20[micro]Pa in air) for impulsive and non-impulsive sounds, and unweighted peak sound
pressure level (SPL) in air (dB re 20[micro]Pa) for impulsive sounds only.
Federal Aviation Administration test aircraft produced sound at all
frequencies measured (50 hertz to 10 kHz) (Healy 1974). At frequencies
centered at 5 kHz, jets flying at 300 m (984 ft) produced \1/3\ octave
band noise levels of 84 to 124 dB, propeller-driven aircraft produced
75 to 90 dB, and helicopters produced 60 to 70 dB (Richardson et al.
1995). Thus, the frequency and level of airborne sounds typically
produced by aircraft are unlikely to cause TTS or PTS unless polar
bears are very close to the sound source.
Although neither TTS nor PTS is anticipated during the specified
activities, aircraft overflights have the potential to elicit
biologically significant behavioral responses from polar bears.
Exposure to aircraft overflights is expected to result in short-term
behavior changes, such as ceasing to rest, walking, or running, and,
therefore, has the potential to be energetically costly. Polar bears
observed during intentional aircraft overflights conducted to study
impacts of aircraft on polar bear responses, with an average flight
altitude of 143 m (469 ft), exhibited biologically meaningful
behavioral responses during 66.6 percent of aircraft overflights. These
behavioral responses were significantly correlated with the aircraft's
altitude, the polar bear's location (e.g., coastline, barrier island),
and the polar bear's activity (Quigley 2022; Quigley et al. 2024).
Polar bears associated with dens exhibited various responses that
ranged from increased head movement and observation of the disturbance
to the initiation of rapid movement and/or den abandonment when exposed
to aircraft flying at altitudes 150 m (492 ft) or less (Larson et al.
2020). Aircraft activities can impact polar bears across all seasons;
however, aircraft have a greater potential to disturb both individuals
and groups of polar bears on land during the summer and fall. These
onshore polar bears are primarily fasting or seeking alternative
terrestrial foods (Cherry et al. 2009; Griffen et al. 2022), and polar
bear responses to aircraft overflights may result in metabolic costs to
their limited energy reserves. To reduce potential disturbance of polar
bears during aircraft activities, mitigation measures, such as minimum
flight altitudes over polar bears and their frequently used areas and
flight restrictions around known polar bear aggregations, will be
implemented when it is safe to do so during aircraft activities.
Effects of In-Water Activities on Polar Bears
Underwater Sound
Noise exposure criteria for identifying underwater noise levels
capable of causing Level A harassment (injury) to marine mammal
species, including polar bears, have been established using the same
methods as those used by the National Marine Fisheries Service (NMFS)
(Southall et al. 2019). These criteria are based on estimated levels of
sound exposure capable of causing a PTS (NMFS 2018). Southall et al.
(2019) developed TTS thresholds for polar bears, which are included in
the ``other marine carnivores'' category, of 188 dB SEL<INF>CUM</INF>
for impulsive underwater sounds and 199 dB SEL<INF>CUM</INF> for
nonimpulsive underwater sounds. Based on these analyses, Southall et
al. (2019) predict that PTS for polar bears will occur at 232 dB peak
sound pressure level or 203 dB SEL<INF>CUM</INF> for impulsive
underwater sound and 219 dB SEL<INF>CUM</INF> for nonimpulsive
underwater sound (table 2).
[[Page 4581]]
Table 2--Temporary Threshold Shift (TTS) and Permanent Threshold Shift (PTS) Thresholds for In-Water Sounds
Established by Southall et al. (2019) Through Modeling and Extrapolation for ``Other Marine Carnivores'', Which
Includes Polar Bears
----------------------------------------------------------------------------------------------------------------
TTS PTS
-----------------------------------------------------------------------------------
Non-impulsive Impulsive Non-impulsive Impulsive
-----------------------------------------------------------------------------------
Peak
SELCUM SELCUM SPL SELCUM SELCUM Peak SPL
----------------------------------------------------------------------------------------------------------------
Water....................... 199 188 226 219 203 232
----------------------------------------------------------------------------------------------------------------
Note: Values are weighted for other marine carnivores' hearing thresholds and given in cumulative sound exposure
level (SELCUM dB re 1[micro]Pa) for impulsive and non-impulsive sounds, and unweighted peak sound pressure
level (SPL) in water (dB 1[micro]Pa) for impulsive sounds only.
The NMFS (2018) Technical Guidance for Assessing the Effects of
Anthropogenic Sound on Marine Mammal Hearing does not identify
thresholds for avoidance of Level B harassment, but NMFS has adopted a
160-dB threshold for Level B harassment from exposure to impulsive
noise and a 120-dB threshold for nonimpulsive noise (High Energy
Seismic Survey Team 1999; NMFS 2018). These thresholds were developed
from observations of mysticete (baleen) whales responding to airgun
operations (e.g., Malme et al. 1983; Malme and Miles 1983; Richardson
et al. 1986, 1995).
We have evaluated the NMFS-recommended Level B harassment
thresholds and determined that the threshold of 120 dB for nonimpulsive
noise is not applicable to polar bears. The 120-dB threshold is based
on studies in which gray whales (Eschrichtius robustus) were exposed to
experimental playbacks of industrial noise (Malme et al. 1983; Malme
and Miles 1983). During these playback studies, southern sea otter
(Enhydra lutris nereis) responses to industrial noise were also
monitored (Riedman 1983, 1984). While gray whales exhibited avoidance
to industrial noise at the 120-dB threshold, there was no evidence of
disturbance reactions or avoidance in southern sea otters. Southall et
al. (2019) includes sea otters and polar bears in the same marine
mammal hearing group of ``other marine carnivores'', so a potential
polar bear response to 120-dB underwater sound is likely more similar
to that of sea otters than gray whales. Thus, given the differences in
hearing and behavior between ``other marine carnivores'' and ``low
frequency cetaceans'', the NMFS 120-dB threshold based on gray whale
behavior is not appropriate for predicting behavioral responses for
polar bears. Based on the best available scientific information about
other marine carnivores, which include polar bears, the FWS has set 160
dB of received underwater sound--for both impulsive and nonimpulsive
sound sources--as a threshold for take by Level B harassment.
The NMFS (2024) has recently updated their Technical Guidance for
Assessing the Effects of Anthropogenic Sound on Marine Mammal Hearing
utilizing the work of Southall et al. (2019). The FWS is evaluating the
new auditory injury criteria from NMFS to determine whether they are
appropriate for FWS trust species. Pending the outcome of those
evaluations, the FWS will continue to use the previous version of the
technical guidance (NMFS 2018) in our assessments of potential Level A
harassment via underwater sound.
In-Water Activity Impacts on Polar Bears
During the specified activities, in-water sources of sound, such as
submarine active sonar use and in-water device data collection
activities, are unlikely to disturb polar bears. Submarine training and
testing activities will occur under the sea ice at depths greater than
a polar bear can dive and during a timeframe when sea ice extent and
concentration are at a maximum during the year. Arctic sea ice extent,
which is the area of ocean with at least 15 percent sea ice
concentration, generally increases throughout February, reaches its
maximum extent in March, and begins decreasing in April (National Snow
and Ice Data Center 2025). The maximum extent and concentration of sea
ice over the project area will limit polar bears' access to open water
and reduce the likelihood of polar bears being exposed to the Navy's
submarine training and testing activities. Other in-water activities
will occur within the ice camp and under the sea ice. If a polar bear
were to enter the ice camp, these in-water activities will cease until
the polar bear left the ice camp. This measure would prevent polar
bears from being exposed to in-water noise from these activities.
If polar bears are exposed to in-water noise from the Navy's
activities, we anticipate that the polar bears' exposure time to in-
water noise would be limited. While polar bears swim and hunt in water,
they spend less time in the water than most marine mammals. Stirling
(1974) reported that polar bears observed near Devon Island, Canada
during late July and early August spent 4.1 percent of their time
swimming and an additional 0.7 percent engaged in aquatic stalking of
prey. More recently, results from the application of tags equipped with
time-depth recorders indicate that aquatic activity of polar bears is
greater than was previously reported. Lone et al. (2018) reported 75
percent of polar bears swam daily during open-water months, with
individuals spending an average of 9.4 percent of their time in the
water throughout July. There was no significant difference in the
amount of time spent in the water between polar bears that used coastal
habitat and polar bears that used offshore pack-ice habitat; however,
the sample size for comparison was small, and polar bears exhibited
large individual variation in their aquatic behavior. While polar bears
typically swim with their ears above water, there are occasions when a
polar bear may dive and therefore have its ears below the surface (Lone
et al. 2018).
The behavior of both polar bears in water or on ice may be impacted
by the presence of humans and equipment used during the specified in-
water activities. During the open-water season in 2012, Shell USA, Inc.
(Shell) vessels encountered a few polar bears swimming in ice-free
water more than 113 km (70 mi) offshore in the Chukchi Sea. In those
instances, the polar bears were observed either to swim away from or
approach the Shell vessels, sometimes swimming around a stationary
vessel before leaving. In at least one encounter, a polar bear
approached, touched, and investigated a stationary vessel from the
water before swimming away. We anticipate that polar bears that
encounter the Navy's submarines at the water's surface during
[[Page 4582]]
deployment, surfacing, and recovery may have an evasive or curious
response similar to the polar bears in these reports. However, neither
curious investigation nor swimming away are likely to result in the
polar bear diving, which is typically seen during hunting.
While exposure to high levels of underwater sound may cause changes
in behavior, temporary or permanent changes in hearing sensitivity, or
discomfort, polar bears do not typically swim with their heads under
water. Additionally, the submarine training and testing activities will
occur under the sea ice at depths greater than a polar bear can dive
and during a timeframe when sea ice extent and concentration are at a
yearly maximum. Though polar bears have been observed in open water
miles from the ice edge or ice floes, these encounters are relatively
rare (although the frequency of such observations may increase due to
sea ice change). If polar bears encounter the Navy's in-water
operations, the effects of such encounters would likely include no more
than short-term behavioral disturbance.
Effects to Denning Polar Bears
Known polar bear dens around industrial infrastructure, discovered
opportunistically and/or during planned surveys for tracking marked
polar bears and detecting polar bear dens, are monitored by the FWS.
However, these sites are only a small percentage of the total active
polar bear dens for the SBS stock in any given year. If potential den
locations are identified during project activities, personnel who are
operating under an incidental take authorization are required to
coordinate with the FWS to avoid activity or potential disturbance
within a designated distance of potential polar bear dens. However, an
unknown polar bear den may be encountered during the Navy's activities.
In instances when a previously unknown den is discovered near human
activity, the FWS has provided guidance to personnel to implement
mitigation measures such as establishing an activity exclusion zone
around the den and 24-hour monitoring of the den site. The Navy will
avoid establishing their ice camp in areas with pressure ridges and
snow drifts greater than 1.5 m (5 ft) deep that may support polar bear
dens as practicable and implement mitigation measures to minimize
disturbance to a den.
The responses of denning polar bears to disturbance and the
consequences of these responses can vary throughout the denning
process, leading to different levels of potential take. We divide the
denning period into four stages when considering impacts of
disturbance: den establishment, early denning, late denning, and post-
emergence; definitions and descriptions are provided by Woodruff et al.
(2022) and are also located in the 2021-2026 Beaufort Sea incidental
take regulations (ITR) (90 FR 27398, June 26, 2025). The stage at which
disturbance occurs defines the level of associated take (Level B
harassment, Level A harassment, or lethal take) that either the female
or cub(s) may experience, along with the probability of such take
occurring (see Denning Analysis below).
Impacts of the Specified Activities on Polar Bear Prey Species
Information on the potential impacts of the specified activities on
polar bear prey species is included in supplemental information, which
can be found as described above in ADDRESSES.
Estimated Take
Definitions of Incidental Take Under the MMPA
Below we provide definitions of three types of take of polar bears.
The FWS does not anticipate and is not authorizing either lethal take
or Level A harassment as a part of this proposed IHA; however, the
definitions of these take types are provided for context and
background.
Lethal Take
Human activity may result in biologically significant impacts to
polar bears. In the most serious interactions (e.g., vehicle collision
or running over an unknown den causing its collapse), human actions can
result in polar bear mortality. Polar bears may be killed in situations
where there is an imminent threat to human life, and polar bears have
been accidentally killed during efforts to deter polar bears from a
work area for safety and from direct chemical exposure (81 FR 52276,
August 5, 2016), though the lethal take in these scenarios is not
considered incidental. Unintentional disturbance of a female polar bear
by human activity during the denning season may cause the female to
abandon her den prematurely before the cubs are able to survive outside
the den, which would result in incidental lethal take of the cubs.
Level A Harassment
Human activity may result in the injury of polar bears. Level A
harassment for military readiness activities is defined as any act that
injures or has the significant potential to injure a marine mammal or
marine mammal stock in the wild. Numerous actions can cause take by
Level A harassment of polar bear cubs during the denning period, such
as creating a disturbance that separates mothers from dependent cubs
(Amstrup 2003), inducing early den emergence during the late denning
period (Amstrup and Gardner 1994; Rode et al. 2018), instigating early
departure from the den site during the post-emergence period (Andersen
et al. 2024), or repeatedly interrupting the nursing or resting of cubs
to the extent that it impacts the cubs' body condition. In these
scenarios, a cub's likelihood of survival may be reduced as a result of
the disturbance (i.e., the cub experiences a negative survival
likelihood consequence).
Level B Harassment
Level B harassment for military readiness activities means any act
that disturbs or is likely to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of natural behavioral patterns,
including, but not limited to, migration, surfacing, nursing, breeding,
feeding, or sheltering, to a point where such behavioral patterns are
abandoned or significantly altered. Changes in behavior that disrupt
biologically significant behaviors or activities for the affected
animal are indicative of take by Level B harassment under the MMPA.
Such reactions include, but are not limited to, the following:
<bullet> Fleeing (running or swimming away from a human or a human
activity);
<bullet> Displaying a stress-related behavior such as jaw- or lip-
popping, front leg stomping, vocalizations, circling, intense staring,
or salivating;
<bullet> Abandoning or avoiding preferred movement corridors such
as ice floes, leads, polynyas, a segment of coastline, or barrier
islands;
<bullet> Using a longer or more difficult route of travel instead
of the intended path;
<bullet> Interrupting breeding, sheltering, or feeding;
<bullet> Moving away at a fast pace (adult) and cubs struggling to
keep up;
<bullet> Temporary, short-term cessation of nursing or resting
(cubs);
<bullet> Ceasing to rest repeatedly or for a prolonged period
(adults);
<bullet> Loss of hunting opportunity due to disturbance of prey; or
<bullet> Any interruption in normal denning behavior that does not
cause injury, den abandonment, or early departure of the female with
cubs from the den site.
This list is not meant to encompass all possible behaviors; other
behavioral responses may be indicative of take by Level B harassment.
Relatively minor changes in behavior such as the animal raising its
head or temporarily changing
[[Page 4583]]
its direction of travel are not likely to disrupt biologically
important behavioral patterns, and the FWS does not view such minor
changes in behavior as indicative of a take by Level B harassment. It
is also important to note that eliciting behavioral responses that
equate to take by Level B harassment repeatedly may result in Level A
harassment.
Surface Interactions
We analyzed take by Level B harassment for polar bears that may
potentially be encountered and impacted during the Navy's mobilization,
operation, and demobilization of a temporary ice camp, aircraft
transportation, submarine training and testing, and research activities
within the geographic region.
Impact Area
To assess the area of potential impact from the project activities,
we calculate the area affected by project activities where harassment
is possible. We refer to this area as an impact area. Behavioral
response rates of polar bears to disturbances are highly variable, and
data to support the relationship between distance to polar bears and
disturbance are limited. Dyck and Baydack (2004) found sex-based
differences in the frequencies of vigilance bouts, which involve an
animal raising its head to visually scan its surroundings, by polar
bears in the presence of vehicles on the tundra. However, in their
summary of polar bear behavioral response to ice-breaking vessels in
the Chukchi Sea, Smultea et al. (2016) found no difference between
reactions of males, females with cubs, or females without cubs. During
the FWS's coastal aerial surveys, 99 percent of polar bears that
responded in a way that indicated possible Level B harassment (polar
bears that were running when detected or began to run or swim in
response to the aircraft) did so within 1.6 km (1 mi), as measured from
the ninetieth percentile horizontal detection distance from the flight
line. Similarly, Andersen and Aars (2008) found that female polar bears
with cubs (the most conservative group observed) began to walk or run
away from approaching snowmobiles at a mean distance of 1,534 m (0.95
mi). Thus, while future research into the reaction of polar bears to
anthropogenic disturbance may indicate that a different zone of
potential impact is appropriate, the current literature suggests that
the 1.6-km (1.0-mi) impact area will encompass the vast majority of
surface polar bear harassment events.
Estimated Harassment From Surface Interactions
We estimated Level B harassment using spatio-temporally specific
encounter rates derived from the U.S. Geological Survey (USGS) polar
bear satellite location data in the Southern Beaufort Sea (Pagano et
al. 2021) and temporally specific harassment rates derived in the 2021-
2026 Beaufort Sea ITR (90 FR 27398, June 26, 2025) in conjunction with
the specified project activity information.
Polar bear encounter rates were determined by selecting SBS adult
female polar bear locations that occurred within the project period
(February-April) across years from 1986 to 2016 in the USGS polar bear
satellite location dataset (Pagano et al. 2021). Based on these
locations, we determined the number and proportion of SBS adult females
that were located within the ice camp study area during the project
period across years. We assumed that SBS adult female step selection
patterns during the spring were similar to step selection patterns of
SBS adult males and SBS subadults based on step selection comparisons
across adult females, adult males, and subadults in the Chukchi Sea
region (Wilson et al. 2022). Given this assumption, we estimated the
number of SBS polar bears across sex and age classes that may occur
within the ice camp study area during the project period. The
proportion of SBS adult females from the USGS dataset that were located
within the ice camp study area during the project period was multiplied
by the SBS polar bear stock abundance estimate to obtain the estimated
number of SBS polar bears within the ice camp study area during the
project period. Encounter rates were calculated as the number of SBS
polar bears encountered per square kilometer within the ice camp study
area.
There is a limited number of polar bear observations from
industrial monitoring reports within the ice camp study area.
Consequently, we could not estimate polar bear harassment rates
specifically within the ice camp study area. Harassment rates derived
in the 2021-2026 Beaufort Sea ITR (86 FR 42982, August 5, 2021) were
used to calculate the number of polar bears potentially harassed during
the project activities. We used the median of the posterior probability
distribution for our harassment rate instead of the upper 99 percent
quantile that was used in the 2021-2026 Beaufort Sea ITR (86 FR 42982,
August 5, 2021) to account for acts that disturb or are likely to
disturb a marine mammal as stipulated in the definition of Level B
harassment for military readiness activities. We used the harassment
rate calculated for the ice season (0.29) to best match the time period
of the specified project activities.
Table 3 provides the definition for each variable used in the
formulas to calculate the number of potential harassment events.
Table 3--Definitions of Variables Used in Harassment Estimates of Non-Denning Polar Bears During Specified
Project Activities
----------------------------------------------------------------------------------------------------------------
Variable Definition
----------------------------------------------------------------------------------------------------------------
B................................................... Polar bears encountered in an impact area for the entire
project period.
a................................................... Project activity impact area.
r................................................... Occupancy rate.
e................................................... Project ice season polar bear-encounter rate in polar
bears/season.
S................................................... Proportion of the project period the area is occupied.
t................................................... Ice season harassment rate.
B................................................... Number of estimated Level B harassment events.
----------------------------------------------------------------------------------------------------------------
As a part of their Request, the Navy provided the FWS with the
estimated project activity areas that included the maximum expected
human occupancy (i.e., rate of occupancy (r<INF>o</INF>)) for the area
of their specified activities (e.g., ice camp site, snowmobile trips)
for the project period. Using the buffer tool in ArcGIS, we created a
spatial file of a 1.6-km (1-mi) buffer around all activity areas. We
binned the activity areas according to their occupancy rates by
rounding them up into tenths (10 percent, 20 percent, etc.). We
determined the impact area of each bin
[[Page 4584]]
by first calculating the area within the buffers of 100 percent
occupancy locations. We then removed the area of the 100 percent
occupancy buffers from the project impact area and calculated the area
within the 90 percent occupancy buffers. This iterative process
continued until we calculated the area within all buffers.
Impact areas were multiplied by the encounter rate to obtain the
number of polar bears expected to be encountered in the impact area for
the project period (B<INF>es</INF>). Equation 1 provides an example of
the calculation of polar bears encountered in the project ice season
for an impact area in the project area.
Bes = ac * eci
Equation 1
To generate the number of estimated Level B harassments for each
impact area, we multiplied the number of polar bears in the impact area
during the project period by the proportion of the project period the
area is occupied, the rate of occupancy, and the harassment rate
(equation 2).
Bt = Bes * Sp * ro * ti
Equation 2
The estimated total impact area for the Navy's on-ice activities is
approximately 533.44 km\2\ (205.96 mi\2\). The estimated polar bear
encounter rate within the Navy's ice camp study area is approximately
0.0033 polar bears/km\2\. Using the above equations, we estimated that
one polar bear would be taken by Level B harassment during the Navy's
on-ice activities. While we estimated that only one polar bear may be
harassed during the Navy's on-ice activities using the above equations,
it is possible that personnel may encounter and harass a female with
cubs (i.e., family group). When a female exhibits a disturbance
response, the cubs will typically respond in a similar manner.
Therefore, we conservatively rounded up our one polar bear estimate to
three polar bears in order to account for the potential harassment of a
family group with an average group size of three polar bears.
Aircraft Impacts on Polar Bears
Polar bears in the project area would likely be exposed to the
visual and auditory stimulation associated with the applicant's fixed-
wing and rotary-wing aircraft activities; however, impacts of these
exposures are likely to be minimal and short term. Aircraft activities
may cause disruptions in the normal behavioral patterns of polar bears
that see or hear the aircraft, thus resulting in incidental Level B
harassment. To reduce the likelihood that polar bears are disturbed by
aircraft, the Navy has committed to multiple mitigation measures, such
as minimum flight altitudes over polar bears and restrictions on sudden
changes to aircraft movements and direction. With these measures in
place, any disturbances to polar bears are expected to have no more
than short-term, temporary, and minor impacts on individual polar
bears.
Estimating Harassment Rates of Aircraft Activities
Harassment rates during aircraft activities were estimated using
results from studies of fixed-wing aircraft and helicopter overflights
(Quigley 2022; Quigley et al. 2024). In these studies, aerial searches
along the northern coast of Alaska between Point Barrow and the western
Canadian border were flown and polar bears were approached at different
altitudes. Polar bears that did not exhibit behavioral changes
consistent with harassment were then re-approached at progressively
lower altitudes, reaching as low as 38 m (100 ft). Researchers recorded
behavioral changes during these approaches and evaluated if and when
Level B harassment occurred. Covariates examined were polar bear
location (``barrier island'' or ``mainland''), initial behavior
(``active'' or ``inactive''), group size, whether the polar bear
belonged to a family group, and the number of previous overflights
(i.e., how many times the group was re-approached to elicit a
behavioral change). A Bayesian imputation approach accounted for polar
bears that exhibited a behavioral change consistent with harassment on
their first approach, thus lacking an identified altitude at which no
harassment occurred due to a lack of a ``non-harassment'' observation.
Their final model included location, activity level, and the number of
previous overflights as predictors of the altitude at which a polar
bear was harassed. For our aircraft impacts analysis, we used
harassment rates estimated for active polar bears observed on barrier
islands as they had the highest rates of harassment. We further assumed
that no previous overflights were conducted. We provide harassment
rates for the minimum flight altitudes submitted by the Navy for their
aircraft activities and harassment rates for take-offs and landings at
table 4.
Table 4--Harassment Rates for Fixed-Wing Aircraft and Rotary-Wing
Aircraft Overflights
------------------------------------------------------------------------
Minimum flight altitude Fixed-wing Rotary-wing
------------------------------------------------------------------------
Take-offs............................... >0.99 >0.99
Landings................................ >0.99 >0.99
15 m (50 ft)............................ 0.99 >0.99
30 m (100 ft)........................... 0.99 >0.99
152 m (500 ft).......................... 0.71 >0.99
457 m (1,500 ft)........................ <0.01 0.05
------------------------------------------------------------------------
Note: The harassment rates in this table are based on Quigley et al.
2024.
Estimating Area of Impact for Aircraft Activities
For each category of the flight path (i.e., take-off, traveling
segments, and landing), we calculated an impact area and duration of
impact using flight hours provided in the Navy's Request. We used
flight logs available through FlightAware (<a href="https://www.flightaware.com">https://www.flightaware.com</a>), a website that maintains flight logs in the
public domain, to estimate impact areas and flight hours for take-offs
and landings. We estimated a take-off distance of 2.41 km (1.5 mi) will
be impacted for 10 minutes per take-off. We estimated a landing
distance of 4.83 km (3 mi) per 305 m (1,000 ft) of altitude will be
impacted for 10 minutes per landing. For traveling segments, the
aircraft was treated as a traveling impact area. We used a hypothetical
flight from the Deadhorse Airport to the northeastern corner of the ice
camp study area, which would have the greatest potential impact of any
flights in the ice camp study area. All flight segments were buffered
by 1.6 km (1 mi), which is consistent with aircraft surveys conducted
by the FWS and the USGS between August and October during most years
from 2000 through 2014 (Schliebe et al. 2008; Atwood et al.
[[Page 4585]]
2015; Wilson et al. 2017). In these surveys, 99 percent of groups of
polar bears that exhibited behavioral responses consistent with Level B
harassment were observed within 1.6 km (1 mi) of the aircraft.
To calculate the total number of Level B harassment events
estimated due to the specified activities, we calculated the number of
flight hours for each flight category (i.e., take-offs, traveling
segments, and landings). The Navy submitted the maximum number of
flight hours for aircraft activities. These flight hours were then used
to calculate the proportion of the project period that aircraft
occupied their impact areas (i.e., take-off area, traveling segment
area, and landing area). This proportion-of-project-period metric is
equivalent to the occupancy rate (r<INF>o</INF>) generated for surface-
level interaction harassment estimates. The total impact area for each
of the flight categories was multiplied by the polar bear encounter
rate to determine the number of polar bears expected in that area for
the project period (i.e., B<INF>es</INF>, as seen in equation 1). This
number was then multiplied by the proportion of the project period to
determine the number of polar bears expected in that area when flights
are occurring, and by the harassment rate based on the minimum flight
altitude to estimate the number of polar bears that may be harassed as
a result of the flights (as seen in equation 2). We did not estimate
any Level B harassment for flight hours at a minimum flight altitude in
which the harassment rate was below 0.50 (e.g., traveling segments at
457 m flight altitude) to only account for acts that disturb or are
likely to disturb a marine mammal as stipulated in the definition of
Level B harassment for military readiness activities.
Estimated Harassment From Aircraft Activities
Using the approaches described above, we estimated the total number
of polar bears expected to be harassed by the aircraft activities
during the proposed IHA period as a total of one polar bear (rounded up
from a fraction). We conservatively increased our one polar bear
estimate to three polar bears in order to account for the average group
size of a family group in case a family group is encountered during
aircraft activities (table 5).
Table 5--Estimated Takes by Level B Harassment of Polar Bears in the Project Area as a Result of Aircraft
Activities During the Proposed Regulatory Period.
----------------------------------------------------------------------------------------------------------------
Large
Reconnaissance military Fixed-wing Rotary-wing UAS Total
flights aircraft aircraft aircraft flights
----------------------------------------------------------------------------------------------------------------
Number of Level B harassments.. <0.01 <0.01 <0.01 <0.01 <0.01 3*
----------------------------------------------------------------------------------------------------------------
* We conservatively increased our one polar bear estimate (rounded up from a fraction) to three polar bears in
order to account for the average group size of a family group in case a family group is encountered.
Estimated Harassment From In-Water Activities
Some of the Navy's in-water activities will involve underwater
active acoustic transmissions, which have the potential to harass
marine mammals underwater. We analyzed potential impacts to polar bears
during the Navy's in-water activities based on polar bear aquatic
behavior information and the description of the Navy's in-water
activities. Polar bears exhibit seasonal variation in their aquatic
behavior, with swimming occurring less often during winter and spring
when ice cover is greater (Lone et al. 2018). Lone et al. (2018)
reported that March was the month with the lowest mean time (2 percent)
that polar bears spent in the water. Polar bears stay at the water's
surface most of the time when they are swimming (Lone et al. 2018) and
typically swim with their ears above water. While polar bears can dive
up to 13.9 m (45.6 ft), most polar bears seldom dive beyond 3 to 4 m
(9.8 to 13.1 ft). Polar bear diving behavior is likely associated with
aquatic stalking of seals and accessing underwater resources such as
carcasses and seaweed (Stirling 1974, Lone et al. 2018). Based on this
information and the low polar bear encounter rate (0.0033 polar bear/
km\2\) in the ice camp study area, we anticipate very few polar bears
to be in the project area with their heads underwater during the
February-April project period, when polar bears are reported to spend
less time swimming (Lone et al. 2018).
The Navy estimated that the areas of increased sound (>160 dB re 1
[micro]Pa) within the hearing range of polar bears will be up to 1 km
(0.6 mi) away from sound sources used during submarine-launched torpedo
exercises and up to 0.5 km (0.3 mi) away from sound sources used during
in-water activities within the ice camp. Considering the small
ensonified area, the low polar bear encounter rate (0.0033 polar bear/
km\2\) on the ice in the ice camp study area, and the low likelihood
that a polar bear will be swimming with its head under water within
hearing range of the Navy's in-water activities, we do not anticipate
hearing threshold shifts for polar bears or behavioral responses
resulting from underwater noise produced during the Navy's in-water
activities. Additionally, submarine activities will occur at depths
greater than a polar bear can dive. Unmanned underwater vehicle
activities, in-water device data collection activities, and underwater
acoustic communication activities will occur under the ice within the
ice camp, and these activities will be halted if a polar bear is
observed near the ice camp. Therefore, the FWS does not anticipate any
harassment of polar bears from the Navy's in-water activities during
the project period.
Denning Analysis
The Navy's on-ice activities are the only potential source of
impacts to denning polar bears. We determined the estimated number of
polar bear dens in the ice camp study area based on the estimated
number of dens that occur on sea ice (Patil et al. 2022) and the
proportion of sea ice dens that may occur in the ice camp study area
based on a USGS empirical dataset of locations of satellite-tagged
female polar bears (Pagano et al. 2021). The SBS stock is estimated to
have a median of 123 dens per year (95 percent posterior credible
interval = 69-199 dens), of which 44 percent are estimated to occur on
sea ice (Patil et al. 2022). Based on this information, we estimated
the number of dens that occur on sea ice annually for the SBS stock by
multiplying the number of dens per year by the proportion of dens on
sea ice (equation 3):
123<INF>dens</INF> * 0.440<INF>prop. sea ice dens</INF> = 54.120 sea
ice dens
Equation 3
We estimated the number of sea ice dens expected to occur within
the ice camp study area by multiplying the
[[Page 4586]]
number of sea ice dens by the proportion of satellite-tagged females
from the USGS dataset (Pagano et al. 2021) that were within the ice
camp study area during the project period from 1986 through 2016
(equation 4).
54.120<INF>sea ice dens</INF> * 0.409<INF>prop. ice camp females</INF>
= 22.140 dens within ice camp study area
Equation 4
The estimated number of dens in the ice camp study area was then
divided by the area (km\2\) of the ice camp study area to obtain a den
encounter rate for the project period (equation 5).
22.140<INF>ice camp study area dens</INF>/
113,927<INF>ice camp study area km</INF>\2\ = 0.000194 dens/km\2\
within ice camp study area
Equation 5
The den encounter rate was then multiplied by the Navy's on-ice
activity impact area to determine the number of dens expected in that
impact area for the project period (i.e., B<INF>es,</INF> as seen in
equation 1). Based on the FWS's analysis of 42 case studies of denning
polar bear responses to human activity, the impact area in which
denning polar bears could exhibit a disturbance response if exposed to
human activity was estimated as 805 m (0.5 mi) around the den site
during the early denning period and 1.6 km (1 mi) around the den site
during the den establishment, late denning, and post-emergence periods
(90 FR 2718, January 13, 2025). We estimated that 0.070 den may be
encountered in the Navy's on-ice activity impact area during the early
denning period and 0.104 den may be encountered in the impact area
during the den establishment, late denning, and post-emergence periods.
Based on our den encounter estimates, we determined the number of
cubs that may experience lethal take, Level A harassment, and Level B
harassment, and the number of females that may experience Level B
harassment as a result of the Navy's on-ice activities. We calculated
probabilities of a den exposure resulting in the types of harassment of
denning polar bears from our analysis of 42 case studies of denning
polar bear responses to human activity (table 6 below). We provide two
sets of harassment probabilities for the post-emergence period. The
first (Post-emergence case 1) is the set of probabilities when a den
has not been disturbed (i.e., experienced harassment) during the late
denning period. The second (Post-emergence case 2) is the set of
probabilities for a den that was disturbed during the late denning
period (Rode et al. 2018, Andersen et al. 2024).
Table 6--Probability That an Exposure Elicited a Response by Denning Polar Bears That Would Result in No Take,
Level B Harassment, Level A Harassment, or Lethal Take
----------------------------------------------------------------------------------------------------------------
No take (female and Level B Level B Level A Den
Denning period cub(s)) (female) (cub(s)) (cub(s)) abandonment
----------------------------------------------------------------------------------------------------------------
Den establishment.................... 0.818 0.182 NA NA NA
Early denning........................ 0.941 0.059 NA NA 0.059
Late denning......................... 0.711 0.289 0 0.289 NA
Post-emergence case 1 \1\............ 0 1.000 0.280 0.720 NA
Post-emergence case 2 \2\............ 0 1.000 0.700 0.300 NA
----------------------------------------------------------------------------------------------------------------
\1\The den was not disturbed (i.e., did not experience harassment) during the late denning period.
\2\The den was disturbed during the late denning period.
Note: Level B harassment was applicable to both females and cubs, if present. Level A harassment and lethal take
were applicable to cubs only and were not possible during the den establishment period, which ended with the
birth of cubs. During the early denning period, there was no Level A harassment for cubs, only den
abandonment, which would result in mortality of any cubs in the den. Probabilities were calculated from the
analysis of 42 case studies of denning polar bear responses to human activity.
To estimate the number of cubs that may experience each type of
harassment, we used the average cub litter size estimated for the SBS
polar bear stock. On average, SBS stock females produce litter sizes of
1.9 cubs (standard deviation=0.5; Smith et al. 2007, 2013; Robinson
2014) at intervals that vary from 1 to 3 or more years depending on cub
survival (Ramsay and Stirling 1988) and foraging conditions.
Polar bear dens would either be in the early denning period (i.e.,
cubs <60 days old) or the late denning period (i.e., cubs >60 days old)
at the start of the Navy's activities. Based on den simulations
obtained from the FWS's polar bear den model (e.g., Wilson and Durner
2020; 90 FR 27398, June 26, 2025), we estimated 29.0 percent of
maternal dens would still have cubs <60 days old at the onset of the
Navy's activities (i.e., February 19). Cubs <60 days old are not viable
outside the den and would suffer a lethal outcome if the female emerged
from the den early (Woodruff et al. 2022). However, this behavioral
response is relatively rare. A review of case studies found that there
is a probability of 0.059 (5.9 percent chance) that a den disturbed
when cubs are <60 days would lead to an early emergence, resulting in
cub mortality (table 6 above). Using this information, we estimated the
number of cubs that may experience a lethal take if a den was disturbed
during the early denning period by multiplying the proportion of dens
in the early denning period by the probability of disturbance resulting
in lethal take of cubs by the number of dens encountered in the early
denning period and by the average cub litter size (equation 6).
0.290<INF>prop. dens in early denning period</INF> *
0.059<INF>prob. of lethal take</INF> *
0.070<INF>den encountered in early denning period</INF> *
1.9<INF>average cub litter size</INF> = 0.002 cubs experiencing lethal
take during the early denning period
Equation 6
This should be considered the maximum potential for harassment
because the probability of the den still being in the early denning
period declines over time and, therefore, the estimated number of cubs
that may experience lethal take arising from den disturbance is highest
at the start of the Navy's on-ice activities. Additionally, a
disturbance causing early emergence during the early denning period
would result in Level B harassment of the female (Woodruff et al.
2022). The estimated number of females that may experience Level B
harassment if a den was disturbed during the early denning period is
0.001, the same as the estimated average number of dens in the early
denning period potentially exposed to disturbance during the Navy's on-
ice activities.
Alternatively, if a den is disturbed during the late denning
period, it could lead to early emergence and potentially have a
negative survival likelihood
[[Page 4587]]
consequence (i.e., Level A harassment) for cubs (Rode et al. 2018,
Woodruff et al. 2022). The FWS's review of case studies found that a
den that is disturbed during the late denning period has a 0.289
probability (28.9 percent chance) of early emergence (table 6 above).
We, therefore, estimated the number of cubs that may experience Level A
harassment from den disturbance during the late denning period by
multiplying the probability of disturbance resulting in Level A
harassment of cubs by the number of dens encountered in the late
denning period and by the average cub litter size (equation 7).
0.289<INF>prob. of Level A harassment</INF> *
0.104<INF>den encountered in late denning period</INF> *
1.9<INF>average cub litter size</INF> = 0.057 cubs experiencing Level A
harassment during the late denning period
Equation 7
Recent research has shown that the negative impacts to cubs'
survival rates associated with early emergence can be offset if the
female and cubs remain at the den site for a longer period of time
(Andersen et al. 2024). We did not account for the female and cubs
remaining at the den site after den emergence in our calculations,
therefore, it is possible that the estimated number of cubs that may
experience Level A harassment during the late denning period is lower
than 0.057 if the female and cubs remain at the den site after early
emergence. The estimated number of females that may experience Level B
harassment if a den was disturbed during the late denning period is
0.030.
It is possible that cubs may experience either Level A harassment
or Level B harassment if a disturbance occurs during the post-emergence
period when the female and cubs are still at the den site. The FWS's
review of case studies found that there is a 0.720 probability (72.0
percent chance) that disturbance of the den will lead to early
departure during the post-emergence period if the den was undisturbed
during the late denning period and a 0.300 probability (30.0 percent
chance) that disturbance of the den will lead to early departure during
the post-emergence period if the den was disturbed during the late
denning period (table 6 above). We used these probabilities to estimate
the probability of cubs that may experience Level A harassment during
the post-emergence period accounting for all cases of disturbances in
the late denning period (equation 8).
0.711<INF>prob. of no take in late denning period</INF> *
0.720<INF>prob. of Level A harassment in post-emergence period case 1</INF>
+ 0.289<INF>prob. of Level A harassment in late denning period</INF> *
0.300<INF>prob. of Level A harassment in post-emergence period case 2</INF>
= 0.599 probability of cubs experiencing Level A harassment during the
post-emergence period
Equation 8
Based on this probability, we calculated the number of cubs that
may experience Level A harassment from den disturbance during the post-
emergence period by multiplying the probability of disturbance
resulting in Level A harassment of cubs during the post-emergence
period, which accounts for all cases of disturbances in the late
denning period, by the number of dens encountered in the post-emergence
period and by the average cub litter size (equation 9).
0.599<INF>prob. of Level A harassment in post-emergence period</INF>
* 0.104<INF>den encountered in post-emergence period</INF> *
1.9<INF>average cub litter size</INF> = 0.118 cubs experiencing Level A
harassment during the post-emergence period
Equation 9
Finally, we estimated the number of cubs that may experience Level
B harassment occurring as a result of the Navy's on-ice activities.
This implies that the polar bears had a behavioral response to
disturbance that was consistent with Level B harassment, but they did
not depart the den site early. As with our calculation for Level A
harassment, we considered the probabilities of cubs that may experience
Level B harassment if a den was disturbed during the post-emergence
period accounting for all cases of disturbances in the late denning
period (table 6 above). We used these probabilities to estimate the
probability of cubs that may experience Level B harassment if a den was
disturbed during the post-emergence period (equation 10).
0.711<INF>prob. of no take in late denning period</INF> *
0.280<INF>prob. of Level B harassment in post-emergence period case 1</INF>
+ 0.289<INF>prob. of Level A harassment in late denning period</INF> *
0.700<INF>prob. of Level B harassment in post-emergence period case 2</INF>
= 0.401 probability of cubs experiencing Level B harassment during the
post-emergence period
Equation 10
Based on this probability, we calculated the number of cubs that
may experience Level B harassment if a den was disturbed during the
post-emergence period by multiplying the probability of disturbance
resulting in Level B harassment of cubs during the post-emergence
period, which accounts for all cases of disturbances in the late
denning period, by the number of dens encountered in the post-emergence
period and by the average cub litter size (equation 11).
0.401<INF>prob. of Level B harassment in post-emergence period</INF> *
0.104<INF>den encountered in post-emergence period</INF> *
1.9<INF>average cub litter size</INF> = 0.079 cubs experiencing Level B
harassment during the post-emergence period
Equation 11
The estimated number of females that may experience Level B
harassment if a den was disturbed during the post-emergence period is
0.104.
In summary, we estimated that between 0.070 and 0.104 dens are
potentially available to be disturbed during the Navy's on-ice
activities if there is suitable denning habitat within the impact area.
Considering that dens and polar bears are not fractional units, we note
that our 0.070 and 0.104 den estimates should be interpreted as there
being a 7.0 percent and 10.4 percent chance that a single den is
potentially exposed to disturbance from the Navy's on-ice activities.
Therefore, the most probable outcome of the Navy's on-ice activities is
that no den is within the impact area, resulting in no impacts to
denning polar bears. However, we further estimated the number of cubs
that may experience each type of harassment during each denning period
and the number of females that may experience Level B harassment during
each denning period for the <1 den that we predicted could be exposed
to the Navy's on-ice activities and potentially disturbed. The
estimated number of cubs that may experience harassment from den
disturbance ranges from 0.002 to 0.118 across the denning periods.
Considering the low probability that one den is potentially exposed to
disturbance during the Navy's on-ice activities, we do not anticipate
any harassment to denning polar bears during the Navy's on-ice
activities.
Critical Assumptions
To conduct this analysis and estimate the potential amount of Level
B harassment, Level A harassment, and lethal take, we made several
critical assumptions.
Polar bear encounter rates are based on SBS adult female satellite
locations within the ice camp study area during the project period from
1986 to 2016 in the USGS dataset (Pagano et al. 2021). There is limited
information comparing the distribution and movements of adult
[[Page 4588]]
females, adult males, and subadults from the SBS stock in the ice camp
study area. We assumed that adult female step selection patterns during
the project period were similar to adult males and subadults from the
SBS stock based on similar step selection patterns between adult
females, adult males, and subadults from the CBS stock (Wilson et al.
2022). This assumption was used to estimate the number of SBS polar
bears across sex and age classes that may occur within the ice camp
study area during the project period.
Level B harassment is equated herein with a disturbance that causes
disruption of natural behavioral patterns to a point where they are
abandoned or significantly altered. There are likely some animals that
respond in ways that indicate some level of disturbance but do not
experience significant biological consequences. Our estimates do not
account for variable responses by polar bear age and sex; however,
sensitivity of denning polar bears was incorporated into the analysis.
The available information suggests that polar bears are generally
resilient to low levels of disturbance. Females with dependent young
and juvenile polar bears are physiologically the most sensitive
(Andersen and Aars 2008) and most likely to experience harassment from
disturbance. There is not enough information on composition of the SBS
polar bear stock in the project area to incorporate individual
variability based on age and sex or to predict its influence on
harassment estimates. Our estimates are derived from a variety of
sample populations with various age and sex structures, and we assume
the exposed population will have a similar composition and that,
therefore, the response rates are applicable.
The estimates of behavioral response presented here do not account
for the individual movements of animals away from the project area or
differential response of animals to noise or human presence due to past
experiences. Our assessment assumes animals remain stationary (i.e.,
density does not change). There is not enough information about the
movement of polar bears in response to specific disturbances to refine
this assumption. Additionally, estimates of behavioral response are
based on polar bear monitoring reports primarily recorded on land.
There is limited information on polar bear responses to human
activities on the sea ice; therefore, we assume polar bear responses to
human activities on the sea ice are similar to polar bear responses to
human activities on land.
When we estimated that take by harassment of only one polar bear
may occur in our analyses, we considered the potential for take by
harassment of family groups. When a female exhibits a disturbance
response, the cubs will typically respond in a similar manner.
Therefore, we assumed that if a family group were to be encountered and
harassed in response to the Navy's activities, then the female and all
cubs would be harassed. On average, SBS stock females produce litter
sizes of 1.9 cubs (standard deviation=0.5; Smith et al. 2007, 2013;
Robinson 2014). We estimate an average group size of three polar bears
for family groups. We conservatively rounded up our one polar bear
estimate to three polar bears in order to account for the potential
harassment of a family group.
The probabilities of den exposure to human activities resulting in
the types of harassment of denning polar bears are based on our
analysis of 42 case studies from land-based dens. Polar bear dens on
the sea ice have been reported to emerge earlier and exhibit shorter
denning durations compared to land-based dens (Rode et al. 2018). An
earlier den emergence date associated with sea ice dens would reduce
the potential for den exposure to human activities resulting in
harassment of denning polar bears. Our estimates for the harassment of
denning polar bears do not account for the earlier den emergence date
and shorter den duration reported for sea ice dens and, therefore,
result in a more conservative estimate of harassment to denning polar
bears during the project.
Sum of Harassment From All Sources
Our analyses quantified the total number of Level B harassment,
Level A harassment, and lethal take likely to result from the Navy's
specified activities. We evaluated four potential sources of
harassment/take, including surface interactions, aircraft overflights,
in-water activities, and den disturbance of females and/or cubs in our
analyses. A summary of total estimated take via Level B harassment
during the project by source is provided in table 7. We do not
anticipate nor authorize take by Level A harassment or lethal take
during the project.
Table 7--Total estimated takes by Level B Harassment of Polar Bears by Source.
----------------------------------------------------------------------------------------------------------------
Surface Aircraft In-water Den
interactions overflights activities disturbance Total
----------------------------------------------------------------------------------------------------------------
Number of estimated Level B harassments 3 * 3 * 0 0 6
----------------------------------------------------------------------------------------------------------------
*We conservatively rounded up our one polar bear estimate to three polar bears in order to account for the
average group size of a family group in case a family group is encountered.
Determinations and Findings
In making these findings, we considered the best available
scientific information, including the biological and behavioral
characteristics of polar bears, the most recent information on polar
bear distribution and abundance within the area of the specified
activities, the current and expected future status of the stock
(including existing and foreseeable human and natural stressors), the
potential sources of disturbance caused by the project, and the
potential responses of polar bears to this disturbance. In addition, we
reviewed applicant-provided materials, information in our files and
datasets, and published reference materials, and consulted with species
experts.
Negligible Impact
We propose a finding that incidental take by Level B harassment of
six polar bears resulting from the specified activities cannot be
reasonably expected to, and is not reasonably likely to, adversely
affect the SBS stock of polar bears through effects on annual rates of
recruitment or survival and would, therefore, have no more than a
negligible impact on the SBS stock of polar bears.
Polar bears are likely to respond to the specified activities with
short-term behavioral reactions or displacement from the project area
during the project period. These reactions are unlikely to have
consequences for the long-term health, reproduction, or survival of
affected polar bears. Most polar bears will respond to disturbance by
moving away from the source, which may cause temporary interruption of
foraging, resting, or other natural behaviors. Affected polar bears are
expected to resume normal behaviors soon after
[[Page 4589]]
exposure with no lasting consequences to their survival or
reproduction. We do not anticipate or propose to authorize any lethal
take or take by Level A harassment of polar bears during the specified
activities. We anticipate up to six polar bears are likely to respond
to disturbance with a biologically significant behavioral change during
the specified activities and these responses to disturbance are
temporary and would not result in measurable changes in survival or
reproduction of affected polar bears.
Our proposed finding of negligible impact applies to incidental
take associated with the specified activities as mitigated by the
avoidance and minimization measures identified in the Navy's mitigation
and monitoring plan. These mitigation measures are designed to minimize
interactions with and impacts to polar bears. These measures and the
monitoring and reporting procedures are required for the validity of
our finding and are a necessary component of the proposed IHA. For
these reasons, we propose a finding that the specified project would
have no more than a negligible impact on the SBS stock of polar bears.
Least Practicable Adverse Impact
We evaluated the practicability and effectiveness of mitigation
measures based on the nature, scope, and timing of the specified
activities and the best available scientific information. The National
Defense Authorization Act for Fiscal Year 2004 amended the MMPA as it
relates to military readiness activities such that least practicable
adverse impact shall include consideration of personnel safety,
practicality of implementation, and impact on the effectiveness of the
military readiness activity. After reviewing the original Request
(submitted April 7, 2025), the FWS discussed additional mitigation
measures with the Navy to reduce the potential impacts of the specified
activities. These additional mitigation measures included: increasing
the avoidance distance to a minimum of 805 m (0.5 mi) away from polar
bears; implementing a maximum avoidance distance (805 m (0.5 mi) or
greater whenever possible) from steep terrain and areas with pressure
ridges or snow drifts greater than 1.5 m (5 ft) to reduce potential
impacts to denning polar bears; requiring personnel to use vehicle-
mounted or handheld forward-looking infrared units and thermal scopes
to the maximum extent practicable when transiting or entering new
terrain within the project area to enhance detection of dens and/or
traveling family groups following den emergence; and requiring
personnel on the ice to observe the surrounding area for polar bears
prior to deploying, recovering, or surfacing of unmanned underwater
vehicles and submarines to the maximum extent practicable. The Navy
incorporated these additional mitigation measures in their revised
Request and supporting documentation (submitted August 21, 2025). We
propose a finding that the mitigation measures included within the
revised Request would ensure least practicable adverse impact on polar
bears.
Avoidance of potential polar bear denning habitat and maintaining
the maximum distance practicable from all known polar bear dens will
minimize impacts to denning females and their cubs during this critical
period. Minimum flight elevations over polar bear areas and flight
restrictions around observed polar bears and known polar bear dens will
reduce the potential for aircraft disturbing polar bears. Finally, the
Navy will implement mitigation measures to prevent the presence and
impact of attractants in the ice camp, such as storing solid waste and
hazardous materials in secure containers inside camp structures. These
measures are outlined in a polar bear interaction plan that was
developed in coordination with the FWS and is part of the Navy's
application for this IHA.
Several additional potential mitigation measures were considered
but determined to be not practicable. These measures are listed below:
<bullet> Require aerial infrared surveys to detect polar bear
dens--Aerial infrared is unable to detect polar bear dens on the sea
ice.
<bullet> Require use of den detection dogs--It is not practicable
or safe to require scent-trained dogs to detect dens due to the
isolated location of the temporary ice camp and large spatial extent
that would need to be surveyed within activity areas.
<bullet> Require all activities to cease if a suspected polar bear
den site is located--It is not practicable or safe to require all
activities to cease if a suspected den site is located due to the
isolated location of the temporary ice camp. If a suspected den site is
located, personnel will avoid the suspected den site and notify the FWS
as soon as possible. The FWS has incorporated reporting requirements
into this proposed IHA for all polar bear interactions.
<bullet> Ground all flights if they must fly below 457 m (1,500
ft)--Requiring all aircraft to maintain an altitude of 457 m (1,500 ft)
at all times is not practicable as some operations may require flying
below 457 m (1,500 ft) to perform necessary inspections or maintain
safety of the flight crew. For other operations, aircraft are required
to fly above 457 m (1,500 ft) at all times within 805 m (0.5 mi) of an
observed polar bear unless there is an emergency or critical logistical
need, such as medical supply delivery or fuel resupply.
<bullet> Spatial and temporal restrictions on surface activity--
Some spatial and temporal restrictions of operations were included in
the Request; however, additional restrictions, such as not operating
during polar bear denning season, would not be practicable for the
specified activities based on potential impacts on the effectiveness of
the military readiness activity.
<bullet> Construct safety gates, fences, and enclosures to prevent
polar bears from accessing facilities--This project will require no
permanent facility/structures and encompasses a large area in an
isolated location. Construction and deconstruction of barriers for a
temporary camp would require additional flights to move equipment and
extend the duration of the project, which could increase disturbance to
polar bears. Personnel will monitor for polar bears approaching the
temporary camp. The FWS has incorporated monitoring and reporting
requirements into this proposed IHA for all polar bear interactions.
<bullet> Require protected species observers for monitoring,
recording, reporting, and implementing mitigation measures--It is not
practicable or safe to hire third-party protected species observers due
to the isolated location of the ice camp, operational constraints, and
the short-term, temporary nature of the specified activities.
Additional personnel may require additional transit vehicles and
accommodations, which could increase disturbance to polar bears. The
Navy will provide polar bear avoidance training and polar bear
monitoring and reporting training to personnel. The FWS has
incorporated monitoring, data recording, and reporting requirements
into this proposed IHA.
Impact on Subsistence Use
Based on past community consultations, locations of hunting areas,
the anticipated lack of overlap of hunting areas and the specified
activities, and the best scientific information available, including
monitoring data from similar activities, we propose a finding that take
caused by the specified activities would not have an unmitigable
adverse impact on the availability of polar bears for taking for
subsistence uses during the specified timeframe.
[[Page 4590]]
While polar bears represent a small portion, in terms of the number
of animals, of the total subsistence harvest for the Kaktovik and
Nuiqsut communities, their harvest is important to Alaska Native
people. The Navy will be required to contact subsistence communities
that may be affected by its activities to discuss potential conflicts
caused by location, timing, and methods of the specified activities.
The Navy must make reasonable efforts to ensure that activities do not
interfere with subsistence hunting and that adverse effects on the
availability of polar bears are minimized. Should such a concern be
voiced, the Navy will develop a plan of cooperation (POC) that
identifies measures to minimize any adverse effects. The POC will
ensure that the specified activities will not have an unmitigable
adverse impact on the availability of the species or stock for
subsistence uses. This POC must provide the procedures addressing how
the Navy will work with the affected Alaska Native communities and what
actions will be taken to avoid interference with subsistence hunting of
polar bears, as warranted.
The FWS is not aware of information that indicates that polar bears
will be deterred from hunting areas or impacted by the specified
project activities in any way that diminishes their availability for
subsistence use.
References Cited
A list of the references cited in this notice may be found at
<a href="https://www.regulations.gov">https://www.regulations.gov</a> under Docket No. FWS-R7-ES-2025-1100.
Required Determinations
National Environmental Policy Act (NEPA)
We have prepared a draft environmental assessment in accordance
with NEPA (42 U.S.C. 4321 et seq.). We have preliminarily concluded
that the proposed action of issuing a final IHA would not significantly
affect the quality of the human environment and, thus, preparation of
an environmental impact statement for this IHA is not required by
section 102(2) of NEPA or its implementing regulations. We are
accepting comments on the draft environmental assessment as specified
above in DATES and ADDRESSES.
Endangered Species Act (ESA)
Under the ESA (16 U.S.C. 1536(a)(2)), all Federal agencies are
required to ensure the actions they authorize are not likely to
jeopardize the continued existence of any threatened or endangered
species or result in destruction or adverse modification of critical
habitat. Prior to issuance of a final IHA, the FWS would complete
intra-service consultation under section 7 of the ESA on our proposed
issuance of an IHA. These evaluations and findings would be made
available on the FWS's website at <a href="https://ecos.fws.gov/ecp/report/biological-opinion">https://ecos.fws.gov/ecp/report/biological-opinion</a>.
Government-to-Government Consultation
It is our responsibility to communicate and work directly on a
Government-to-Government basis with federally recognized Alaska Native
Tribes in developing programs for healthy ecosystems. We are also
required to consult with Alaska Native Claims Settlement Act (ANCSA)
Corporations in certain circumstances. We seek their full and
meaningful participation in evaluating and addressing conservation
concerns for protected species. It is our goal to remain sensitive to
Alaska Native culture, and to make information available to Alaska
Native people. Our efforts are guided by the following policies and
directives:
(1) The Native American Policy of the Service (January 20, 2016);
(2) the Alaska Native Relations Policy (currently in draft form;
see 87 FR 66255, November 3, 2022);
(3) Executive Order 13175 (January 9, 2000);
(4) Department of the Interior Secretarial Orders 3206 (June 5,
1997), 3225 (January 19, 2001), 3317 (December 1, 2011), 3342 (October
21, 2016), and 3403 (November 15, 2021) and Director's Order 227
(September 8, 2022);
(5) the Alaska Government-to-Government Policy (a Departmental
memorandum issued January 18, 2001); and
(6) the Department of the Interior's policies on consultation with
Alaska Native Tribes and organizations.
We have evaluated possible effects of the proposed IHA on federally
recognized Alaska Native Tribes and ANCSA Corporations. The FWS has
determined that authorizing the Level B harassment of up to six polar
bears from the Navy's specified activities would not have any Tribal
implications or ANCSA Corporation implications and, therefore,
Government-to-Government consultation or Government-to-ANCSA
Corporation consultation is not necessary. However, we invite continued
discussion, either about the project and its impacts or about our
coordination and information exchange throughout the IHA/POC public
comment process.
Paperwork Reduction Act
This proposed IHA does not contain any new collection of
information that requires approval by the Office of Management and
Budget (OMB) under the Paperwork Reduction Act of 1995 (44 U.S.C. 3501
et seq.). The OMB has previously approved the information collection
requirements associated with IHAs and assigned OMB Control Number 1018-
0194 (expires August 31, 2026). An agency may not conduct or sponsor,
and a person is not required to respond to, a collection of information
unless it displays a currently valid OMB control number.
Proposed Authorization
We propose to authorize the nonlethal, incidental take by Level B
harassment of up to six polar bears from the SBS stock of polar bears.
Authorized take would be limited to disruption of behavioral patterns
that may be caused by mobilization, operation, and demobilization of a
temporary ice camp, aircraft transportation, submarine training and
testing, and research activities conducted by the Navy in the Beaufort
Sea and Arctic Ocean, between February 9, 2026, and April 9, 2026. We
do not anticipate or propose to authorize any take by Level A
harassment, injury, or death to polar bears resulting from these
activities.
A. General Conditions for the IHA for the Navy
(1) Activities must be conducted in the manner described in the
Navy's revised Request dated August 21, 2025, for an IHA and in
accordance with all applicable conditions and mitigation measures. The
taking of polar bears whenever the required conditions, mitigation,
monitoring, and reporting measures are not fully implemented as
required by the IHA is prohibited. Failure to follow the measures
specified both in the revised Request and within this proposed
authorization may result in the modification, suspension, or revocation
of the IHA.
(2) If project activities cause unauthorized take (i.e., take of
more than six polar bears from the SBS stock by Level B harassment, a
form of take other than Level B harassment, or take of one or more
polar bears through methods not described in the IHA), the Navy must
report the details of the incident to the FWS as soon as practicable.
(3) All operations managers, vehicle operators, and aircraft pilots
must receive a copy of this IHA and maintain
[[Page 4591]]
access to it for reference at all times during project work. These
personnel must understand, be fully aware of, and be capable of
implementing the conditions of the IHA at all times during project
work.
(4) This IHA will apply to activities associated with the specified
project as described in this document and in the Navy's revised
Request. Changes to the specified project without prior authorization
may invalidate the IHA.
(5) The Navy's revised Request is approved and fully incorporated
into this IHA unless exceptions are specifically noted herein. The
revised Request includes:
<bullet> The Navy's original request for an IHA, dated April 7,
2025;
<bullet> The Navy's Polar Bear Interaction Management and Avoidance
Plan, dated April 7, 2025; and
<bullet> The Navy's revised request for an IHA, dated August 21,
2025.
(6) Operators will allow the FWS personnel or the FWS's designated
representative to visit project work sites to monitor for impacts to
polar bears and subsistence uses of polar bears at any time throughout
project activities if it is safe to do so. ``Operators'' are all
personnel operating under the Navy's authority, including all
contractors and subcontractors.
B. Avoidance and Minimization
The Navy must implement the following policies and procedures to
avoid interactions and minimize to the greatest extent practicable any
adverse impacts on polar bears, their habitat, and the availability of
these marine mammals for subsistence uses.
(1) General Avoidance Measures. The Navy must cooperate with the
FWS and other designated Federal, State, and local agencies as
appropriate to monitor and mitigate the impacts of activities on polar
bears.
(2) Trained and qualified personnel must be designated to monitor
for the presence of polar bears, initiate mitigation measures, and
monitor, record, and report the effects of the activities on polar
bears. The Navy must provide all operators with polar bear awareness
training prior to their participation in project activities.
(3) An FWS-approved polar bear safety, awareness, and interaction
plan must be on file with the FWS Marine Mammals Management office and
available onsite. The interaction plan must include:
(i) A description of the specified activity (i.e., a summary of the
plan of operations);
(ii) A food, waste, and other attractants management plan;
(iii) Personnel training, policies, procedures, and materials;
(iv) Site-specific polar bear interaction risk evaluation and
mitigation measures;
(v) Polar bear avoidance and encounter procedures; and
(vi) Polar bear observation and reporting procedures.
(4) The Navy must contact potentially affected subsistence
communities and hunter organizations to discuss potential conflicts
caused by the activities and provide the FWS documentation of
communications as described in D. Measures To Reduce Impacts to
Subsistence Users.
(5) Mitigation measures for on-ice activities. The Navy must
undertake the following activities to limit disturbance around polar
bears on the ice and known polar bear dens:
(i) Operators must observe for polar bears during travel activities
on the ice.
(ii) Operators must use vehicle-mounted or handheld forward-looking
infrared units and thermal scopes to the maximum extent practicable
when transiting or entering new terrain within the project area to
enhance detection of dens and/or traveling family groups (female with
cubs) following den emergence. Areas along any pressure ridges, snow
drifts greater than 1.5 m (5 ft) in height, snow piles, steep terrain,
and any other areas that may provide suitable snow buildup for denning
polar bears in the project area must be surveyed.
(iii) Operators must maintain a minimum avoidance distance of 805 m
(0.5 mi) from all polar bears, except in the event of an emergency.
(iv) Vehicle operators must travel in a predictable manner and
avoid sudden changes in speed and direction when in the vicinity of
polar bears.
(v) Vehicle operators must follow established routes when
available. Vehicle operators must not follow a polar bear, except in
the event of actively deterring the polar bear if the situation
requires.
(vi) Operators must implement infrastructure planning, design, and
management, as well as snow management on the ice camp site, to
eliminate potential polar bear bedding/denning areas and to reduce risk
of surprise encounters.
(vii) Operators must avoid or maintain the maximum distance
practicable (805 m (0.5 mi) or greater whenever possible) from steep
terrain and areas with pressure ridges or snow drifts greater than 1.5
m (5 ft) in height that may support polar bear dens and ringed seal
(primary polar bear prey species) subnivean lairs.
(viii) All observed or suspected polar bear dens must be reported
to the FWS prior to the initiation of activities.
(ix) If a suspected den site is located, the Navy will immediately
consult with the FWS to analyze the data and determine if additional
surveys or mitigation measures are required. The FWS will determine
whether the suspected den is to be treated as a putative den for the
purposes of this IHA.
(x) Operators must observe an operational exclusion zone at the
maximum distance practicable (1.6 km (1 mi) or greater whenever
possible) around all putative polar bear dens during the denning season
(November-April, or until the female and cubs leave the areas). Should
a suspected den be discovered within 1.6 km (1 mi) of activities, work
must be relocated or cease in the area of the den and the Navy must
consult with the FWS as soon as practicable for additional guidance.
(6) Mitigation measures for in-water activities. Operators on the
ice must observe the surrounding area for polar bears prior to
deploying, recovering, or surfacing of unmanned underwater vehicles and
submarines to the maximum extent practicable.
(i) Operators must avoid deploying, recovering, or surfacing
unmanned underwater vehicles and submarines if a polar bear is within
805 m (0.5 mi) of the underwater vehicle to the maximum extent
practicable.
(7) Mitigation measures for aircraft activities. Operators of
support aircraft shall, at all times, conduct their activities at the
maximum distance practicable from concentrations of polar bears.
(i) Aircraft operations within the project area will maintain a
minimum altitude of 457 m (1,500 ft) above ground level, except during
take-off and landing or when a lower flight altitude is necessary for
operational reasons, or for safety due to weather or restricted
visibility.
(ii) Under no circumstances, other than an emergency, will aircraft
operate at an altitude lower than 457 m (1,500 ft) within 805 m (0.5
mi) of a polar bear observed on ice, land, or in water measured in a
straight line between the polar bear and the ground/water directly
underneath the aircraft. Rotary-wing aircraft may not hover or circle
above such areas or within 805 m (0.5 mi) of such areas. If weather
conditions or operational constraints necessitate operation of aircraft
at altitudes below 457 m (1,500 ft), the operator must avoid areas of
known polar bear concentrations and should take
[[Page 4592]]
precautions to avoid flying directly over or within 805 m (0.5 mi) of
these areas.
(iii) Operators must plan all aircraft routes to minimize flight
hours over predominantly coastal areas and sea ice over the continental
shelf.
(iv) Operators must plan all aircraft routes to minimize any
potential conflict with active or anticipated polar bear hunting
activity as determined through community consultations.
(v) Aircraft will not land within 805 m (0.5 mi) of a polar bear.
If a polar bear is observed while the aircraft is grounded in remote
areas without shelter, personnel will board the aircraft and leave the
area. The aircraft operator will also avoid flying over the polar bear
if possible. Operators should avoid making any sudden maneuvers,
especially when traveling at lower altitudes, even if such maneuvers
are intended to avoid polar bears. If a polar bear is observed within
the landing zone or work area, operators should travel away from the
site and slowly increase altitude to 457 m (1,500 ft) or a level that
is safest and viable given current traveling conditions. Aircraft may
not be operated in such a way as to separate individual polar bears
from a group (i.e., two or more polar bears).
(vi) Operators must not track or follow polar bears with aircraft,
including unmanned aircraft systems (UAS).
C. Monitoring
(1) Operators must provide onsite observers and implement the FWS-
approved polar bear avoidance and interaction plan to apply mitigation
measures, monitor the project's effects on polar bears and subsistence
uses, and evaluate the effectiveness of mitigation measures.
(2) All onsite observers shall complete an FWS-provided training
course designed to familiarize individuals with monitoring and
mitigation activities identified in the polar bear avoidance and
interaction plan.
(3) Onsite observers must be present during all operations and must
record all polar bear observations, identify and document potential
harassment, and work with personnel to implement appropriate mitigation
measures.
(4) Operators shall cooperate with the FWS and other designated
Federal, State, and local agencies as appropriate to monitor impacts of
project activities on polar bears. Where information is insufficient to
evaluate the potential effects of activities on polar bears and the
subsistence use of this species, the Navy may be required to
participate in joint monitoring efforts to address these information
needs and ensure the least practicable adverse impact to this resource.
D. Measures To Reduce Impacts to Subsistence Users
The Navy must conduct its activities in a manner that, to the
greatest extent practicable, minimizes adverse impacts on the
availability of polar bears for subsistence uses.
(1) The Navy will be required to develop an FWS-approved POC if,
through community consultation, concerns are raised regarding impacts
to subsistence harvest or Alaska Native Tribes and Organizations.
(2) If an FWS-approved POC is required, the Navy will implement
that POC.
(3) Prior to conducting the project, the Navy will take the
following steps to reduce potential effects on subsistence harvest of
polar bears:
(i) Avoid work in areas of known polar bear subsistence harvest;
(ii) Notify the Native Village of Kaktovik and the Native Village
of Nuiqsut of the specified project activities;
(iii) Work to resolve any concerns of potentially affected Alaska
Native Tribal Organizations and Corporations regarding the project's
effects on subsistence hunting of polar bears;
(iv) If any unresolved or ongoing concerns of potentially affected
Alaska Native Tribal Organizations and Corporations remain, modify the
POC in consultation with the FWS and subsistence stakeholders to
address these concerns; and
(v) Implement FWS-required mitigation measures that will reduce
impacts to subsistence users and their resources.
E. Reporting Requirements
The Navy must report the results of monitoring to the FWS Marine
Mammals Management office via email at <a href="/cdn-cgi/l/email-protection#f29485c5ad9f9f9fad8097829d808681b2948581dc959d84"><span class="__cf_email__" data-cfemail="f39584c4ac9e9e9eac8196839c818780b3958480dd949c85">[email protected]</span></a>.
(1) In-season monitoring reports.
(i) Activity progress reports. The Navy must:
(A) Notify the FWS at least 48 hours prior to the onset of
activities;
(B) Notify the FWS within 48 hours of project completion or end of
the work period.
(ii) Polar bear observation reports. The Navy must report, within
48 hours, all observations of polar bears and potential polar bear dens
during any project activities. Upon request, monitoring report data
must be provided in a common electronic format (to be specified by the
FWS). Injured, dead, or distressed polar bears that are clearly not
associated with project activities (e.g., animals found outside the
project area, previously wounded animals, or carcasses with moderate to
advanced decomposition or scavenger damage) must also be reported to
the FWS immediately, and not later than 48 hours after discovery.
Photographs, video, location information, or any other available
documentation must be included. Information in the observation report
must include, but need not be limited to:
(A) Date and time of each observation;
(B) Locations of the observer and polar bears (GPS coordinates if
possible);
(C) Number of polar bears;
(D) Sex and age class--adult, subadult, cub (if known);
(E) Observer name and contact information;
(F) Weather, visibility, and if at sea, sea state, and sea ice
conditions at the time of observation;
(G) Estimated initial distance when first observed and closest
distance of polar bears from personnel and facilities;
(H) Type of work being conducted at time of observation;
(I) Possible attractants present;
(J) Polar bear behavior--initial behavior when first observed
(e.g., walking, swimming, resting, etc.);
(K) Potential reaction--behavior of polar bear potentially in
response to presence or activity of personnel and equipment;
(L) Description of the encounter;
(M) Duration of the encounter; and
(N) Mitigation actions taken.
(2) Human-polar bear interaction reports. The Navy must report all
human-polar bear interaction incidents immediately, and not later than
48 hours after the incident. A human-polar bear interaction incident
includes any situation in which there is a possibility for unauthorized
take. Example scenarios include when project activities exceed those
included in an IHA, when a mitigation measure was required but not
enacted, or when injury or death of a polar bear occurs. Reports must
include:
(i) All information specified for an observation report in
paragraphs (1)(ii)(A)-(N) of this section E;
(ii) A complete detailed description of the incident; and
(iii) Any other actions taken.
(3) Final report. The results of monitoring and mitigation efforts
identified in the polar bear avoidance and interaction plan must be
submitted to the FWS for review within 90 days of the expiration of
this IHA. Upon request, final report data must be provided in a common
electronic format
[[Page 4593]]
(to be specified by the FWS). Information in the final report must
include, but need not be limited to:
(i) Copies of all observation reports submitted under the IHA;
(ii) A summary of the observation reports;
(iii) A summary of monitoring and mitigation efforts including
areas, total hours, total distances, and distribution;
(iv) Analysis of factors affecting the visibility and detectability
of polar bears during monitoring;
(v) Analysis of the effectiveness of mitigation measures;
(vi) A summary and analysis of the distribution, abundance, and
behavior of all polar bears observed; and
(vii) Estimates of take in relation to the specified activities.
Request for Public Comments
If you wish to comment on this proposed authorization, the
associated draft environmental assessment, or both documents, you may
submit your comments by either of the methods described above in
ADDRESSES. Please identify if you are commenting on the proposed
authorization, draft environmental assessment, or both; make your
comments as specific as possible; confine them to issues pertinent to
the documents; and explain the reason for any changes you recommend.
Where possible, your comments should reference the specific section or
paragraph that you are addressing. The FWS will consider all comments
that are received before the close of the comment period (see DATES
above). The FWS does not anticipate extending the public comment period
beyond the 30 days required under section 101(a)(5)(D)(iii) of the
MMPA.
Comments, including names and street addresses of respondents, will
become part of the administrative record for this proposal. Before
including your address, telephone number, email address, or other
personal identifying information in your comment, be advised that your
entire comment, including your personal identifying information, may be
made publicly available at any time. While you can ask us in your
comments to withhold your personal identifying information from public
review, we cannot guarantee that we will be able to do so.
Peter Fasbender,
Assistant Regional Director for Fisheries and Ecological Services,
Alaska Region.
[FR Doc. 2026-01945 Filed 1-30-26; 8:45 am]
BILLING CODE 4333-15-P
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</html>Indexed from Federal Register on February 2, 2026.
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