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[Federal Register Volume 90, Number 136 (Friday, July 18, 2025)]
[Notices]
[Pages 33982-34005]
From the Federal Register Online via the Government Publishing Office []
[FR Doc No: 2025-13488]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

[Docket No. FWS-R7-ES-2025-0021; FXES111607MRG01-256-FF07CAMM00]


Marine Mammals; Proposed Incidental Harassment Authorization for 
the Southern Beaufort Sea Stock of Polar Bears and Pacific Walruses in 
West Harrison Bay, AK; Draft Environmental Assessment

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of receipt of application; notice of availability of 
proposed authorization and 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, as amended, 
from Narwhal LLC, propose to authorize nonlethal, incidental take by 
harassment of small numbers of Pacific walruses (Odobenus rosmarus 
divergens) and Southern Beaufort Sea (SBS) polar bears (Ursus 
maritimus) between August 1, 2025, and July 31, 2026. The applicant 
requested this authorization for take by harassment that may result 
from activities associated with shallow hazard surveys, preliminary 
field surveys, exploratory drilling operations, and summer cleanup 
activities in West Harrison Bay, Alaska. This proposed authorization, 
if finalized, will be for up to 15 takes of walruses and 13 takes of 
polar bears by Level B harassment only. No take by injury or mortality 
is requested, expected, or proposed to be authorized. We invite 
comments on the proposed incidental harassment authorization and the 
accompanying draft environmental assessment from the public and local, 
State, Tribal, and Federal agencies.

DATES: Comments must be received by August 18, 2025.

ADDRESSES: 
    Document availability: You may view supplemental information at 
 under Docket No. FWS-R7-ES-2025-0021. 
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:
     Electronic submission: Go to the Federal eRulemaking 
Portal: . In the Search box, enter FWS-R7-
ES-2025-0021, 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  before 11:59 p.m. (Eastern Time) on the date 
specified in DATES.
     U.S. mail: Public Comments Processing, Attn: Docket No. 
FWS-R7-ES-2025-0021, 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 . 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 
[email protected], 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, 
as amended (MMPA; 16 U.S.C. 1361, et seq.), authorizes the Secretary of 
the Interior (Secretary) to allow, upon request, the incidental, but 
not intentional, taking by harassment of small numbers of marine 
mammals in response to requests by U.S. citizens (as defined in title 
50 of the Code of Federal Regulations (CFR) in part 18, at 50 CFR 
18.27(c)) engaged in a specified activity (other than commercial 
fishing) in a specified geographic region 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). 
According to the MMPA, the FWS shall allow this incidental taking by 
harassment if we make findings that the total of such taking for the 1-
year period:
    (1) is of small numbers of marine mammals of a species or stock;
    (2) will have a negligible impact on such species or stocks; and
    (3) 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,

[[Page 33983]]

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 activities other than military readiness activities 
or scientific research conducted by or on behalf of the Federal 
Government means any act of pursuit, torment, or annoyance which (i) 
has the potential to injure a marine mammal or marine mammal stock in 
the wild (the MMPA defines this as ``Level A harassment''), or (ii) has 
the potential to disturb a marine mammal or marine mammal stock in the 
wild by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering (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 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 ``small numbers'' is also defined in 50 CFR 18.27. 
However, we do not rely on that definition here as it conflates ``small 
numbers'' with ``negligible impacts.'' We recognize ``small numbers'' 
and ``negligible impacts'' as two separate and distinct requirements 
when reviewing requests for incidental harassment authorizations (IHA) 
under the MMPA (see Natural Res. Def. Council, Inc. v. Evans, 232 F. 
Supp. 2d 1003, 1025 (N.D. Cal. 2003)). Instead, for our small numbers 
determination, we estimate the likely number of marine mammals to be 
taken and evaluate if that number is small relative to the size of the 
species or stock.
    The term ``least practicable adverse impact'' is not defined in the 
MMPA or its enacting regulations. For this IHA, 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.
    If the requisite findings are made, we shall issue an IHA, which 
may set forth the following, where applicable: (i) permissible methods 
of taking; (ii) other means of effecting the least practicable impact 
on the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for subsistence 
uses by coastal-dwelling Alaska Natives (if applicable); and (iii) 
requirements for monitoring and reporting take by harassment.

Summary of Request

    On November 4, 2024, the FWS received a request on behalf of 
Narwhal LLC (ECO49 Consulting LLC 2024) for authorization to take by 
nonlethal incidental harassment Pacific walruses (Odobenus rosmarus 
divergens) and Southern Beaufort Sea (SBS) polar bears (Ursus 
maritimus) during shallow hazard surveys (SHS), preliminary field 
surveys, exploratory drilling operations, and summer cleanup activities 
in West Harrison Bay, Alaska, for a period between August 1, 2025, and 
July 31, 2026. Their request also included a proposed Polar Bear and 
Pacific Walrus Safety, Awareness, and Interaction Plan. The FWS 
requested further information on March 10, 2025. We discussed with the 
applicant operational timelines, project area modifications, and 
mitigation measures. Narwhal submitted a revised application on April 
3, 2025. The FWS deemed the revised request dated April 2025 (received 
by the FWS April 3, 2025; hereafter referred to as the ``Request''), 
adequate and complete on April 10, 2025.

Description of Specified Activities and Specified Geographic Region

    The specified activities described in the request consist of SHS, 
preliminary field surveys, exploratory drilling operations, and summer 
cleanup activities in West Harrison Bay, Alaska (figures 1 and 2, 
below; ECO49 Consulting LLC 2024).
BILLING CODE 4333-15-P

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[GRAPHIC] [TIFF OMITTED] TN18JY25.000


[[Page 33985]]


[GRAPHIC] [TIFF OMITTED] TN18JY25.001

BILLING CODE 4333-15-C

Archeological

    Narwhal will conduct airborne archeological surveys of areas with 
potential soil disturbance, including shallow offshore areas. Surveys 
will be conducted via helicopter maintaining a minimum flight altitude 
of 457 m (except for landing/take-off or when forced lower by unsafe 
weather conditions), with aerial transect widths of approximately 1.3 
kilometers (km) (0.8 miles [mi]). If necessary, the archeological 
survey crew will land to investigate landforms that may contain 
cultural or historical resources. During these surveys, helicopters 
will be based out of Deadhorse, Alaska. Surveys are expected to last 
approximately three days, with one flight per day. These surveys must 
occur during the snow-free season, which is typically mid- to late-July 
through early-September.

Lake Surveys and Thermistor Installation

    To support ice road and ice pad construction, Narwhal will extract 
freshwater from lakes inland from West Harrison Bay. These lakes have 
been preliminarily identified in the request as the large lakes found 
along Narwhal's proposed water access roads (see figures 1 and 2). 
However, to confirm that the lakes are sufficient water sources, 
Narwhal will conduct lake surveys beginning on August 1, 2025, and 
lasting 15 days. To conduct the surveys, crews of up to four personnel 
will transit via helicopter maintaining a minimum flight altitude of 
457 m (except for landing/take-off or when forced lower by unsafe 
weather conditions), originating from Deadhorse, and then on foot along 
proposed tundra access routes, where they will collect fish, 
bathymetric, and water quality data from each proposed freshwater 
supply lake. During lake surveys, thermistors (temperature sensors) may 
be installed in the tundra to depths of 30 centimeters (cm) (11.8 
inches [in]) along tundra access routes to confirm that soil 
temperature is acceptable to support tundra travel during lake access 
in the winter.

Shallow Hazard Surveys

    Narwhal will evaluate the subsea strata in the areas of proposed 
offshore exploration wells. Beginning in August 2025, Narwhal will use 
an echosounder/fathometer, side scan sonar, sub-bottom profiler, 
sparker, mini vibracore sampler, and a 1,721-cubic-centimeter (cm\3\) 
(105-cubic-inch [in\3\]) generator and injector airgun to perform SHS 
at each of the six proposed offshore exploratory well locations within 
West Harrison Bay (see figures 1 and 2). These investigations will 
enable site selection for exploratory drilling based on the most 
suitable seafloor and subsurface characteristics. The surveys will 
collect data on the bathymetry of the area, and also include side-scan 
sonar, sub-bottom profiling, high-resolution three-dimensional (3D) 
seismic imaging, and possibly vibracore sediment sampling. These 
instruments will also be used to evaluate the potential for offshore 
archeological resources in the proposed well locations. Two additional 
sites are in 0.6 meters (m) (2 feet [ft]) of water depth or less and 
will be evaluated using alternative techniques approved by the AOGCC 
rather than techniques used for deeper water. Of the eight potential 
drilling locations, Narwhal anticipates drilling no more than five 
wells during January to April 2026. The sixth, seventh and eighth sites 
will serve as alternate drilling locations.
    The SHS program will be mobilized by vessel out of West Dock in 
Prudhoe

[[Page 33986]]

Bay or from Oliktok Point. Periodic resupply, logistics support, and 
personnel transfers for the SHS program are planned to originate from 
Oliktok Point. Narwhal estimates daily vessel trips between Oliktok 
Point and the West Harrison Bay work area will be required over a 
period of 45 days during SHS operations. The 3D seismic survey will 
require one vessel equipped with a single airgun, one vessel 
responsible for deploying and retrieving geophones on the seafloor, and 
one to two support vessels for berthing crew and expediting. The non-3D 
seismic SHS work (bathymetry, sub-bottom profiler, side scan sonar, and 
sparker) will be conducted from a single vessel, with the possible 
inclusion of one additional vessel for additional berth capacity, if 
necessary. The berthing vessel may transit to Oliktok Point during the 
day, if necessary, to pick up supplies or transport personnel.
    The sound-producing instruments for SHS include an echosounder/
fathometer, a side-scan sonar, a sub-bottom profiler, and a sparker. 
The echosounder and side-scan sonar will be operated at a frequency at 
or above 200 kilohertz (kHz). The sub-bottom profiler and sparker will 
produce sounds within a frequency range of 2 kHz to 16 kHz and 300 
hertz (Hz) to 1.5 kHz, respectively, and at an estimated sound source 
level of 202 decibels referenced to a pressure of 1 microPascal (dB re 
1[mu]Pa). This sound production, however, will be highly directional 
and focused within a beam width of 20 degrees.
    Vibracore sampling may be required at the exploratory drilling 
locations. Narwhal intends to use a mini vibracore sampler that is 
designed for shallow water. Sampling would entail a core barrel 
oscillated by an electric motor into the sediment for 1 to 2 minutes at 
a time, with the entire coring process lasting up to 1 hour. Similar 
vibracoring equipment has been shown to create a sound pressure level 
(SPL) of 187.4 dB re 1[mu]Pa in the Chukchi Sea at a frequency range of 
10 kHz to 20 kHz (Chorney et al. 2011).
    The SHS program will also include high-resolution 3D seismic 
surveys at the proposed exploratory well locations. Surveys will be 
completed using a 1,721-cm\3\ (105- in\3\) generator and injector 
airgun that is towed behind a survey vessel perpendicularly over a 
series of geophone sound receivers that have been anchored to the 
seafloor. Geophones will be embedded at a maximum depth of 2 m (6.6 ft) 
in a grid pattern. The airgun will fire every 12.5 m (41 ft) along the 
track lines, resulting in firing once every 6-7 seconds while traveling 
at a speed of approximately 2 m (6.6 ft) per second.
    Narwhal submitted with their request a sound transmission loss 
model for the anticipated noise produced by the airgun. Using the 
Gundalf Designer software package, Narwhal's contracted acousticians 
modeled the peak sound pressure level (SPL) anticipated from a single 
airgun shot to be 231.0 dB re 1[mu]Pa at 1 m (3.3 ft) from the sound 
source (ECO49 Consulting LLC 2024). The cumulative (unweighted) sound 
exposure level (SELCUM) was also assessed using 192 airgun 
shots (which represented one transect line) and was 193.0 dB re 
1[mu]Pa\2\ at 1 m (3.3ft) from the sound source. Approximately 480 
geophones will be deployed per potential drilling location, and they 
will be spaced every 50 m (164 ft). Geophones will be anchored into the 
seafloor using a wood or metal pole to a maximum depth of 2 m (6.6 ft). 
The survey will occur in a sequence of geophone placement for 2 days, 
followed by airgun deployment for 1 or 2 days (for up to 12 hours per 
day). While airgun deployment occurs, the next grid of geophones will 
be laid in a second location, and during airgun deployment at the 
second location, geophones will be retrieved from the first location. 
This sequence of events will continue for approximately 30 days.

Advance Equipment Staging

    Equipment may be staged in advance of winter activities, to reduce 
the total number of all-terrain vehicle (ATV) trips and time required 
for mobilizing project equipment to West Harrison Bay. If equipment is 
staged in advance, approximately 120 fewer trips will be needed from 
Oliktok Point to West Harrison Bay. This would allow Narwhal to begin 
ice road and ice pad construction operations in early December 2025 
before the sea ice road from Oliktok Point to West Harrison Bay is 
complete.
    Equipment will potentially be staged in one of two locations. The 
first location uses an existing gravel airstrip on the Kogru River, 
which would be covered with a series of interlocking tundra mats as 
early as August 2025. Barges would then offload materials from the 
Kogru River onto the tundra mats and airstrip. This option is dependent 
upon sufficient water depths in the Kogru River near the airstrip. 
Bathymetry surveys will be conducted as described above to determine 
the option's suitability. The second option would involve the placement 
of six to eight empty barges, a camp barge, and fuel barge in a 
protected location in West Harrison Bay. These barges would be frozen 
in place in the fall of 2025. The barges would be anchored to the beach 
and tied together to provide a continuous staging platform for 
equipment. Barges may also be anchored into the seafloor, which 
consists of fine-grained clay and silt, at a depth of 0.5-2 m (1.6-6.6 
ft).
    Approximately 378,541 liters (100,000 gallons) of fuel would be 
staged during the advanced staging process. A two-person caretaker crew 
would remain onsite from September 15 until November 15 to monitor fuel 
and cargo. This crew would have a small skid camp equipped with a 
generator, kitchen, bunks, shower, waterless toilet, and heat. All food 
waste and trash would be kept inside and stored in secure containers. 
The personnel would be resupplied by a helicopter on a weekly basis, 
and would also be equipped with bear deterrence equipment, emergency 
response equipment, and communications. The barges would be monitored 
after December 1, 2025, by the startup crew onsite to conduct early 
development tasks for the project and prepare the equipment and 
materials for deployment to the first construction location if advanced 
staging is used.

Maternal Den Surveys and Den Exclusion Zones

    Narwhal will conduct two aerial infrared (AIR) maternal den surveys 
to identify active polar bear dens in the area. The surveyors will use 
AIR cameras on fixed-wing aircraft with flights flown between 244-457 m 
(800-1,500 ft) above ground level at a speed of <185 km per hour (km/h) 
(<115 miles per hour [mph]). These surveys will be concentrated on 
areas within 1.6 km (1 mi) of project activities that would be suitable 
for polar bear denning activity such as drainages, banks, bluffs, or 
other areas of topographic relief. The first survey will be conducted 
between December 1 and December 25, 2025, and the second survey will be 
conducted between December 15, 2025, and January 10, 2026, with a 
minimum of 24 hours between surveys.
    Narwhal will avoid an 805 m operational exclusion zone around known 
polar bear dens during the denning season (November to April, or until 
the female and cubs leave the area). Should previously unknown occupied 
dens be discovered within 805 m of activities, local work will 
immediately cease. All personnel and vehicles will be moved beyond the 
den exclusion zone, to the extent practical. Narwhal will contact the 
FWS for guidance and to evaluate these instances

[[Page 33987]]

on a case-by-case basis to determine the appropriate action. Potential 
actions may include rerouting of access trails or roads, cessation, or 
modification of work, conducting additional monitoring or other 
avoidance practices. Narwhal will coordinate with the FWS and implement 
additional measures specified by the FWS.

Coastal Sea Ice Trail

    As soon as there is stable, grounded sea ice, construction will 
begin on a coastal sea ice road from Oliktok Point to West Harrison Bay 
to assist in equipment mobilization. Construction is estimated to begin 
in early December 2025. A small, 15- to 20-person camp will be created 
on a 0.008-square-kilometer (km\2\) (0.003-square-mile [mi\2\]) ice pad 
adjacent to Oliktok Point on grounded sea ice. The crew will then 
continue constructing a sea ice road over the Colville River Delta, 
which will require thickening to support heavy equipment in three to 
four channels of the Colville River. Thickening will take approximately 
25 days. Approximately six seawater pumping units will travel in six 
trips to the Colville River Delta from Oliktok Point and remain in the 
general location during the thickening phase of construction. Crews 
will take approximately six trips per day between Oliktok Point and the 
western edge of the delta for resupply. After the Colville River 
crossings are thickened, the remainder of the sea ice road will be 
completed in approximately 5 days. The second segment of road 
construction will require a smaller, two-person crew and two ATVs to 
scout the road and create spatial reference points. Total construction 
of the coastal sea ice trail is expected to take 30 days.

Equipment Mobilization

    All equipment, including Rolligons, Steiger tractors, PistenBullys, 
Tucker Sno-Cats, ATVs, and a drilling rig, will be moved to West 
Harrison Bay over the coastal sea ice road. Camp and ice construction 
equipment will be transported first, followed by exploratory drilling 
equipment. The coastal sea ice road is anticipated to have vehicle 
traffic from the time of its construction to the approximate end of 
demobilization on May 5, 2026.

Local Sea Ice Road/Trail and Sea Ice Pad Construction

    Narwhal will construct local sea ice roads or trails in West 
Harrison Bay to support drilling operations. Sea ice roads are created 
by clearing and grading snow, then pumping seawater through drilled 
holes in the ice to achieve the desired ice thickness. Freshwater is 
often used to strengthen the top layer of ice on the road. Nearby 
freshwater lakes will be used as the source of freshwater, which will 
be accessed by constructing onshore ice roads and trails (see figures 1 
and 2). Alternatively, sea ice trails may be created and used by 
tracked vehicles, which do not require capping with fresh water. The 
final decision to construct sea ice trails versus sea ice roads will be 
determined by several factors including freshwater availability, the 
availability of ATV-compatible equipment (e.g., skid mounted vac unit 
versus vac truck on wheels), and project schedule. Regardless of 
whether roads or trails are constructed, freshwater access is required 
for ice pad construction, exploratory drilling operations, and use in 
camp.
    Onshore ice trails/roads will be constructed on land to access 
freshwater lakes. Initial ground disturbance activities including 
staking and packing snow, flooding, grading, and other construction 
activities may begin as soon as the first week of December 2025 if 
advance staging occurs. If advanced staging does not occur, 
construction will begin in early January 2026. Narwhal may choose to 
construct a northward spur trail originating from the North Slope 
Borough Community Winter Access Trail (CWAT; figure 1). The 
construction of this spur would provide Narwhal an additional route of 
mobilization and demobilization if environmental conditions prevent 
construction of the sea ice trail. The FWS considered the spur in our 
analyses, however, Narwhal is not requesting authorization for take 
incidental to activities on the CWAT. All ice road and/or trail 
construction will be initiated by March 1, 2026.
    Ice pad construction will be concurrent with the construction of 
ice trails or roads and will take approximately 2 to 3 weeks depending 
on water depth and ambient temperatures. After ice thickening, ice pads 
will consist of a circular area of raised, grounded ice with a diameter 
of approximately 220 m (722 ft). In-depth construction methodology is 
available in Narwhal's associated IHA request (ECO49 Consulting LLC 
2024).

Temporary Airstrip and Camp Facilities

    Narwhal will construct temporary airstrips on grounded sea ice 
adjacent to each ice pad for the four easternmost well sites (figures 1 
and 2). An additional airstrip will be constructed adjacent to one of 
the two potential base camp sites (figure 2). Only one base camp sea 
ice airstrip will be constructed, however we analyzed the impacts of 
both options in our take estimates to avoid underestimating impacts 
from potential activities. Construction of each temporary airstrip will 
entail plowing snow off the sea ice to provide a smooth surface for 
aircraft and installing perimeter lighting for visual flight 
operations. Initially, aircraft equipped with skis will likely be 
utilized until a freshwater cap can be placed on the airstrip to allow 
for landings by wheeled aircraft. The airstrip will be 23 m (75.5 ft) 
wide and 915 m (3,002 ft) long and, if necessary, may be extended to 
1,525 m (5,003 ft) in length prior to exploratory drilling operations. 
Aircraft will use temporary airstrips as early as December 6, 2025, 
through demobilization by May 5, 2026. Camp facilities will be 
comprised of modules approximately 3.7 m (12 ft) wide by 18 m (59 ft) 
long set side by side with an estimated camp footprint size of 100 m 
(328 ft) by 50 m (164 ft). Sufficient space will be allotted to this 
area to maintain clear site lines for early detection of polar bears in 
the vicinity.

General Aircraft Activity Considerations

    Narwhal will utilize both fixed-wing and rotary aircraft during 
their operations. Except for take-off and landing, aircraft will not 
operate at altitudes lower than 457 m within 805 m of polar bears or 
walruses observed on ice, land, or in water. Helicopters will not 
hover, circle, or land within this distance. When weather conditions do 
not allow a 457-m flying altitude, aircraft may be operated below this 
altitude for the minimum duration necessary to maintain aircraft 
safety. Aircraft will not fly over any identified Pacific walrus 
haulouts. Aircraft will not fly directly over or within 805 m of areas 
of known polar bear or walrus concentrations unless aircraft departure 
to avoid freeze up, medical supply delivery, fuel resupply, or other 
unforeseen critical health or safety concerns require. Aircraft routes 
will be planned to minimize potential conflicts with active or 
projected polar bear or walrus subsistence hunting activity as 
determined through community consultations. Aircraft will not land 
within 805 m of observed polar bears or walrus. If a polar bear or 
group of bears is observed while the aircraft is grounded, personnel 
will board the aircraft and leave the area. Aircraft will not be 
operated in such a way as to separate members of a group of polar bears 
or walruses from other members of the group.

Exploratory Drilling

    Drilling operations will begin following successful sea ice road 
and ice

[[Page 33988]]

pad construction. The exploratory drilling rig will be assembled on 
site over a period of 7 to 10 days. Following assembly, drilling is 
estimated to take 21 to 30 days per well, including moving to a new 
site. Operations will occur 24 hours a day. Rig moves between sites are 
anticipated to take 5 days or fewer and require 60 truck trips. 
Drilling is expected to take approximately 86 days in total. All 
exploratory wells will be plugged and abandoned during the 2025-2026 
winter season.

Demobilization and Summer Cleanup

    All project equipment and materials will be removed from the West 
Harrison Bay area following completion of exploratory drilling. 
Demobilization will require up to 200 ATV trips from the drilling 
locations to Oliktok Point. Once the tundra is snow-free in July 2025, 
Narwhal will clean up debris associated with the project using a small 
helicopter crew. One helicopter, originating in Deadhorse, will fly for 
approximately 6 hours per day, to complete six trips with an estimated 
total of 60 landing events and 60 take-off events. Helicopter will 
maintain a minimum flight altitude of 457 m except for landing or take-
off events or if forced lower by unsafe weather conditions.

Description of Marine Mammals in the Specified Geographic Region

    The SBS polar bears and Pacific walruses are the only marine mammal 
species under the FWS's jurisdiction likely to be found within the 
specified geographic region. Information on range, stocks, biology, and 
climate impacts on Pacific walruses and SBS polar bears can be found in 
the supplemental information (available as described above in ADDRESSES 
section).

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 helicopter overflights, tundra travel, vessel activity, seismic 
data acquisition, mobilization and operation of camp facilities, and 
cleanup 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 Guti[eacute]rrez 2003). 
However, individual response to noise disturbance can be based on 
previous interactions, sex, age, and maternal status (Andersen 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 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

    A larger percentage of polar bears are spending more time on land 
during the open water season, which may increase the risk for human-
polar bear interactions (Atwood et al. 2015; Rode et al. 2022). 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 polar bears and 
humans 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). Polar bear interaction plans 
detail the policies and procedures that will be implemented by Narwhal 
to avoid attracting and interacting with polar bears as well as 
minimizing impacts to the polar bears. Interaction plans also detail 
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 industrial infrastructure and 
activities can be useful for better understanding polar bear 
distribution, behavior, and interactions with humans. Technology that 
may be used to facilitate detection and monitoring of polar bears 
includes bear monitors and thermal cameras. It is possible that human-
polar bear interactions may occur during the specified activities, and 
mitigation measures will be implemented by Narwhal to minimize the risk 
of human-polar bear interactions during the specified activities.
    From mid-July to mid-November, SBS polar bears can be found in 
large numbers and high densities on barrier islands, along the 
coastline, and in the nearshore waters of the Beaufort Sea, 
particularly on and around Barter and Cross Islands (Wilson et al. 
2017). This distribution leads to a significantly higher number of 
human-polar bear interactions on land and at offshore structures during 
the open-water season than other times of the year. Polar bears that 
remain on the multi-year pack ice are not typically present in the ice-
free areas where vessel traffic occurs, as barges and vessels 
associated with industry activities travel in open water and avoid 
large ice floes.
    On land, most polar bear observations occur within 2 km (1.2 mi) of 
the coastline based on polar bear monitoring reports. Facilities within 
the offshore and coastal areas are more likely to be approached by 
polar bears, and they may act as physical barriers to polar bear 
movements. As polar bears encounter these facilities, the chances for 
human-polar bear interactions increase. However, polar bears have 
frequently been observed crossing existing roads and causeways and they 
appear to traverse the human-developed areas as easily as the 
undeveloped areas based on monitoring reports.

Effects of Aircraft Overflights on Polar Bears

    Polar bears experience increased noise and visual stimuli when 
fixed-wing aircraft or helicopters 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 kHz (tests were 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 (PTS). 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. A TTS is a noise-
induced threshold shift in hearing sensitivity that fully recovers over 
time (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

[[Page 33989]]

of systematic modeling procedures and extrapolations, Southall et al. 
(2019) generated modified noise exposure thresholds for both in-air and 
underwater sound (table 1, table 2).

 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
--------------------------------------------------------------------------------------------------------------------------------------------------------
         SELCUM                    SELCUM                   Peak SPL                   SELCUM                    SELCUM                  Peak SPL
--------------------------------------------------------------------------------------------------------------------------------------------------------
                 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[mu]Pa) for
  impulsive and nonimpulsive sounds, and unweighted peak sound pressure level in air (dB re 20[mu]Pa) for impulsive sounds only.

    Federal Aviation Administration test aircraft produced sound at all 
frequencies measured (50 Hz 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, impacts from 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 walking running, or ceasing to rest 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 bear's location (e.g., coastline, barrier island), and 
the 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 of 150 m 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 
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 conducted 
when safe to perform these operations during aircraft activities.

Underwater Sounds

    Noise exposure criteria for identifying underwater noise levels 
capable of causing Level A harassment (injury) to marine mammal 
species, including polar bears and walruses, 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 permanent shift 
in hearing sensitivity (i.e., a permanent threshold shift (PTS) (NMFS 
2018)). 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 (SELcum) 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 
temporary threshold shifts (TTS) detected in lab settings during sound 
exposure trials (Finneran 2015). A TTS is a noise-induced threshold 
shift in hearing sensitivity that fully recovers over time (Finneran 
2015). Southall et al. (2019) developed TTS thresholds for polar bears 
and walruses, both of which are included in the ``other marine 
carnivores'' category, of 188 dB SELCUM for impulsive 
underwater sounds and 199 dB SELCUM for nonimpulsive 
(continuous) underwater sounds. Based on these analyses, Southall et 
al. (2019) predict that PTS for polar bears and walruses will occur at 
232 dB peak or 203 dB SELCUM for impulsive underwater sound 
and 219 dB SELCUM for nonimpulsive underwater sound (table 
2).

[[Page 33990]]



    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 and Walruses
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                     TTS                                                                          PTS
--------------------------------------------------------------------------------------------------------------------------------------------------------
      Non-impulsive                            Impulsive                            Non-impulsive                           Impulsive
--------------------------------------------------------------------------------------------------------------------------------------------------------
         SELCUM                    SELCUM                   Peak SPL                   SELCUM                    SELCUM                  Peak SPL
--------------------------------------------------------------------------------------------------------------------------------------------------------
                 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 20[mu]Pa) for
  impulsive and nonimpulsive sounds, and unweighted peak sound pressure level in water (dB 1[mu]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 continuous noise (HESS 1999; NOAA 
2005). 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) and from 
equating Level B harassment with noise levels capable of causing TTS in 
lab settings.
    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 or walruses. 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, polar bears, 
and walruses in the same marine mammal hearing group of ``other marine 
carnivores,'' so a potential polar bear or walrus response to 120-dB 
underwater sound is likely more similar to that of sea otters than gray 
whales. Thus, given the different range of frequencies to which ``other 
marine carnivores'' and ``low frequency cetaceans'' are sensitive 
(Southall et al. 2019), the NMFS 120-dB threshold based on gray whale 
behavior is not appropriate for predicting behavioral responses for 
polar bears or walruses, particularly for low-frequency sound. Based on 
the best available scientific information about other marine 
carnivores, which include polar bears and walruses, 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 estimates of potential harassment 
via underwater sound.

Effects of In-Water Activities on Polar Bears

    In-water sources of sound, such as bathymetric surveys, side-scan 
sonar, vibracore sampling, high-resolution 3D seismic surveys, or 
vessel noises are unlikely to disturb polar bears. 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 marine portion of the specified activities will only 
occur during the open-water season in relatively ice-free, open water, 
or during the winter months on sea ice. Though polar bears have been 
observed in open water miles from the ice edge or ice floes, the 
encounters are relatively rare (although the frequency of such 
observations may increase due to sea ice change). If bears encounter 
Narwhal's operations in open water, the effects of such encounters 
would likely include no more than short-term behavioral disturbance.
    While polar bears swim in and hunt from open water, they spend less 
time in the water than most marine mammals. Stirling (1974) reported 
that polar bears observed near Devon Island 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, application 
of tags equipped with time-depth recorders indicate that aquatic 
activity of polar bears is greater than was previously thought. In a 
study published by Lone et al. (2018), 75 percent of polar bears swam 
daily during open-water months, with animals spending 9.4 percent of 
their time in July in the water. Both coastal and pack-ice-dwelling 
animals were tagged, and there were no significant differences in the 
time spent in the water by animals in the two different habitat types. 
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 specified activities may introduce substantial levels of noise 
into the marine environment at sound levels capable of causing a 
behavioral change or temporary or permanent damage to polar bear 
hearing (table 2). However, the majority of the sound-producing 
instruments that will be used for SHS do not produce in-water sound 
above the threshold designated for Level B harassment or they do not 
produce sound within the hearing range of polar bears. The echosounder 
and side-scan sonar will be operated at a frequency at or above 200 
kilohertz (kHz), which is outside the hearing range for polar bears 
(Southall et al. 2019). The sub-bottom profiler and sparker will 
produce sounds within the hearing range of polar bears (2 kHz to 16 kHz 
and 300 hertz (Hz) to 1.5 kHz, respectively), and at an estimated sound 
source level above the Level B harassment threshold (202 decibels 
referenced to a pressure of 1 microPascal (dB re 1[micro]Pa)); however, 
this sound production will be highly directional and focused within a 
beam width of 20 degrees. The areas of increased sound (>160 dB re 1 
[micro]Pa, or the Level B harassment threshold) due to airgun sound 
transmission will be up

[[Page 33991]]

to 3,188 m (10,459 ft) away from seismic source vessels, but the area 
in which sound would exceed PTS (or Level A harassment) thresholds 
would be no more than 10 m (33 ft) from the sound source.
    Polar bear behavior is expected to be impacted by the presence of 
humans and equipment. In 2012 during the open-water season, Shell USA, 
Inc (Shell) vessels encountered a few polar bears swimming in ice-free 
water more than 112.6 km (70 mi) offshore in the Chukchi Sea. In those 
instances, the bears were observed to either 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 vessels during the 
specified activities may have an evasive or curious response, similar 
to these reports. However, neither curious investigation nor swimming 
away are likely to result in the polar bear diving, which is typically 
seen during hunting. Further, we do not anticipate bears diving from 
ice floes into the water, as West Harrison Bay is anticipated to be ice 
free during high-resolution 3D seismic surveys.

Effects to Denning Polar Bears

    Known polar bear dens around the oil fields and other areas of the 
North Slope are monitored by the FWS. These dens may be discovered 
opportunistically or through tracking of tagged individuals. However, 
these sites are only a small percentage of the total active polar bear 
dens for the SBS stock in any given year. Potential maternal polar bear 
dens may also be identified using AIR surveys. These surveys are 
conducted annually by North Slope operators in coordination with the 
FWS. If potential den locations are identified, operators 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 these areas. However, an unknown polar 
bear den may be encountered during Narwhal's activities. In instances 
when a previously unknown den is discovered near North Slope 
activities, the FWS has provided guidance to operators to implement 
mitigation measures such as an activity exclusion zone around the den 
and 24-hour monitoring of the den site.
    The responses of denning polar bears to disturbance and the 
consequences of these responses can vary throughout the denning 
process. 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. (2022a) and are also located in the 2021-2026 Beaufort 
Sea Incidental Take Regulations (ITR) (86 FR 42982, August 5, 2021). 
The stage at which harassment occurs defines the level of disturbance 
response (Level B harassment, Level A harassment, or Lethal) attributed 
to either the sow or cub(s), along with the probability of the specific 
response occurring (see Denning Analysis).

Impacts of the Specified Activities on Polar Bear Prey Species

    Information on the potential impacts of the specified activities on 
polar bear prey species can be found in Supplemental Information to 
this document (available as described above in ADDRESSES).

Walrus: Human-Walrus Encounters

    Pacific walruses (also referred to hereafter as ``walruses'') do 
not inhabit the Beaufort Sea frequently. The likelihood of encountering 
walruses during industry operations is low and limited to the open-
water season. During the time period of this IHA, industry operations 
may occasionally encounter small groups of walruses swimming in open 
water or hauled out onto ice floes or along the coast. Industry 
monitoring data have reported 49 walruses between 1995 and 2023, with 
only a few instances of disturbance to those walruses (AES Alaska 2015; 
USFWS unpublished data). If walruses are encountered during the 
activities proposed in this IHA, the interaction could potentially 
result in disturbance.
    Anecdotal observations by walrus hunters and researchers suggest 
that males tend to be more tolerant of disturbances than females, and 
individuals tend to be more tolerant than groups. Females with 
dependent calves are considered least tolerant of disturbances. In the 
Chukchi Sea, disturbance events are known to cause walrus groups to 
abandon land or ice haulouts and occasionally result in trampling 
injuries or cow-calf separations, both of which are potentially fatal. 
Calves and young animals at terrestrial haulouts are particularly 
vulnerable to trampling injuries. However, due to the lack of previous 
walrus haulouts in West Harrison Bay, the most likely potential impacts 
of the specified activities include displacement from preferred 
foraging areas, increased stress, energy expenditure, interference with 
feeding, and masking of communications. Any impact of human presence on 
walruses is likely to be limited to a few individuals due to their 
geographic range and seasonal distribution.
    The reaction of walruses to vessel traffic is dependent upon vessel 
type, distance, speed, and previous exposure to disturbances. Walruses 
in the water appear to be less readily disturbed by vessels than 
walruses hauled out on land or ice. Furthermore, barges and vessels 
associated with industry activities travel in open water and avoid 
large ice floes or land where walruses are likely to be found. In 
addition, walruses can use a vessel as a haulout platform. In 2009, 
during industry activities in the Chukchi Sea, an adult walrus was 
observed hauled out on the stern of a vessel.

Walrus: Effects of In-Water Activities

    Walruses hear sounds both in in-air and in-water. They have been 
shown to hear from 60 Hz to 23 kHz in air (Reichmuth et al. 2020). 
Tests of underwater hearing have shown their range to be between 1 kHz 
and 12 kHz with greatest sensitivity at 12 kHz (Kastelein et al. 2002). 
The underwater hearing abilities of the Pacific walrus have not been 
studied sufficiently to develop species-specific criteria for 
preventing harmful exposure. However, sound level thresholds have been 
developed for members of the ``other marine carnivore'' group of marine 
mammals (tables 1 and 2).
    The specified activities may introduce substantial levels of noise 
into the marine environment at sound levels capable of causing a 
behavioral change or temporary or permanent damage to walrus hearing 
(table 2). However, the majority of the sound-producing instruments 
that will be used for SHS do not produce in-water sound above the 
threshold designated for Level B harassment or they do not produce 
sound within the hearing range of walruses. The echosounder and side-
scan sonar will be operated at a frequency at or above 200 kilohertz 
(kHz), which is outside the hearing range for walruses (Southall et al. 
2019). The sub-bottom profiler and sparker will produce sounds within 
the hearing range of walruses (2 kHz to 16 kHz and 300 hertz (Hz) to 
1.5 kHz, respectively), and at an estimated sound source level above 
the Level B harassment threshold (202 dB re 1[micro]Pa); however, this 
sound production will be highly directional and focused within a beam 
width of 20 degrees. The areas of increased sound (>160 dB re 1 
[micro]Pa, or the Level B harassment threshold) due to airgun sound 
transmission will be up to 3,188

[[Page 33992]]

m (10,459 ft) away from seismic source vessels, but the area in which 
sound would exceed PTS (or Level A harassment) thresholds would be no 
more than 10 m (33 ft) from the sound source.
    If walruses are present within the Level B harassment threshold up 
to 3,188 m (10,459 ft) away from seismic source vessels, noise may 
prevent ordinary communication between individuals and prevent them 
from locating one another. The noise may also prevent walruses from 
using potential habitats in West Harrison Bay and may have the 
potential to alter the frequency or duration of biologically 
significant behaviors such as feeding, foraging, or nursing. The most 
likely response of walruses to acoustic disturbances in open water 
would be for animals to move away from the source of the disturbance. 
Displacement from a preferred feeding area may reduce foraging success, 
increase stress levels, and increase energy expenditures.

Walrus: Effects of Aircraft Overflights

    Aircraft overflights may disturb walruses. Reactions to aircraft 
vary with range, aircraft type, and flight pattern, as well as walrus 
age, sex, and group size. Adult females, calves, and immature walruses 
tend to be more sensitive to aircraft disturbance. Walruses are 
particularly sensitive to changes in engine noise and are more likely 
to stampede when planes turn or fly low overhead. Researchers 
conducting aerial surveys for walruses in sea ice habitats have 
observed little reaction to fixed-winged aircraft above 457 m (1,500 
ft) (USFWS unpublished data). Although the intensity of the reaction to 
noise is variable, walruses are probably most susceptible to 
disturbance by fast-moving and low-flying aircraft (100 m (328 ft) 
above ground level) or aircraft that change or alter speed or 
direction. In the Chukchi Sea, there are recent examples of walruses 
being disturbed by aircraft flying in the vicinity of haulouts. It 
appears that walruses are more sensitive to disturbance when hauled out 
on land versus sea ice. However, as Pacific walrus only occur in low 
numbers in the South Beaufort Sea, with no known mass haulout sites, 
the impacts of aircraft are expected to be negligible.

Estimated Take

Definitions of Incidental Take Under the Marine Mammal Protection Act

    Below we provide the circumstances under which the three types of 
take of polar bears or walruses may occur. The FWS does not anticipate 
and is not authorizing either Level A harassment or lethal take as a 
part of this proposed IHA; however, an explanation of these take types 
is 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, 
running over an unknown den causing its collapse), human actions can 
result in the mortality of polar bears. We also note that, while not 
considered incidental, in situations where there is an imminent threat 
to human life, polar bears may be killed. Additionally, though not 
considered incidental, 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). Unintentional 
disturbance of a female polar bear by human activity during the denning 
season may cause the female to abandon her cubs in the den before the 
cubs can survive on their own. Either scenario may result in the 
incidental lethal take of the cubs. Incidental lethal take of Pacific 
walruses could occur if the animal were directly struck by a vessel or 
trampled by other walruses in a human-caused stampede at a walrus 
haulout site.

Level A Harassment

    Human activity may result in the injury of walruses or polar bears. 
Level A harassment, for nonmilitary readiness activities, is defined as 
any act of pursuit, torment, or annoyance that has the 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. As with lethal take, walruses are 
most vulnerable to Level A harassment when congregated in haulouts. The 
risk of stampede-related injuries increases with the number of animals 
hauled out and with the duration spent on coastal haulouts. Calves and 
young are the most vulnerable to suffer injuries and/or mortality (88 
FR 53510, August 8, 2023).

Level B Harassment

    Level B harassment for nonmilitary readiness activities is defined 
as any act of pursuit, torment, or annoyance that has the potential to 
disturb a marine mammal or marine mammal stock in the wild by causing 
disruption of behavioral patterns, including, but not limited to, 
migration, breathing, nursing, feeding, or sheltering. 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:
     Fleeing (running or swimming away from a human or a human 
activity);
     Displaying a stress-related behavior such as jaw or lip-
popping, front leg stomping, vocalizations, circling, intense staring, 
or salivating for polar bears;
     Abandoning or avoiding preferred movement corridors such 
as ice floes, leads, polynyas, a segment of coastline, barrier islands, 
or other resting sites;
     Abandoning prey or feeding areas;
     Using a longer or more difficult route of travel instead 
of the intended path;
     Interrupting breeding, sheltering, or feeding;
     Moving away at a fast pace (adult) and polar bear cubs or 
walrus calves struggling to keep up;
     Temporary, short-term cessation of nursing or resting 
(cubs or calves);
     Ceasing to rest repeatedly or for a prolonged period 
(adults);
     Loss of hunting opportunity due to disturbance of prey; or
     Any interruption in normal polar bear denning behavior 
that does not cause injury, den abandonment, or early departure of the 
female polar bears 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 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.

Pacific Walrus: All Interactions

    With the low occurrence of walruses in the Beaufort Sea and the 
adoption of the mitigation measures required by this

[[Page 33993]]

IHA, the FWS concludes that the only anticipated effects from the 
specified activities in the Beaufort Sea would be short-term behavioral 
alterations of small numbers of walruses. All walrus encounters within 
the geographic area in the past 10 years have been of solitary walruses 
or groups of two. The closest sighting of a grouping larger than two 
was outside the specified geographical area in 2013, when a vessel 
encountered a group of 15 walruses. Thus, while highly unlikely that a 
group of walruses will be encountered during the proposed activities, 
we estimate that no more than 15 Pacific walruses will be taken by 
Level B harassment during the specified activities. Harassment of no 
more than 15 Pacific walruses may occur from behavioral responses to 
vessels, or from behavioral changes in response to noise greater than 
160 dB re 1 [micro]Pa created by high-resolution 3D seismic imaging.

Polar Bear: Surface-Based Interactions

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 a zone or area of influence. 
Behavioral response rates of polar bears to disturbances are highly 
variable, and data to support the relationship between distance to 
polar bears and disturbance is limited. Dyck and Baydack (2004) found 
sex-based differences in the frequencies of vigilance bouts of 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 or began to run when detected 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 a different zone of potential 
impact is appropriate, the current literature suggests that the 
application of a 1.6-km (1.0-mi) disturbance zone will encompass the 
vast majority of polar bear harassment events.
Estimated Harassment
    We estimated Level B harassment using the spatio-temporally 
specific encounter rates and temporally specific harassment rates 
derived in the 2021-2026 Beaufort Sea ITR (86 FR 42982, August 5, 2021) 
in conjunction with Narwhal's project operations footprint. Table 3 
provides the definition for each variable used in the take formulas. 
Using the approaches described above, we estimated the total number of 
polar bears expected to be harassed by surface-based interactions 
during the proposed IHA period as a total of three bears (table 10).

 Table 3--Definitions of Variables Used in Take Estimates of Non-Denning
                Polar Bears in West Harrison Bay, Alaska
------------------------------------------------------------------------
             Variable                            Definition
------------------------------------------------------------------------
Bes...............................  Bears encountered in zone of
                                     potential impact for the entire
                                     season.
ac................................  Coastal exposure area.
ai................................  Inland exposure area.
ro................................  Occupancy rate.
eco...............................  Coastal open water season bear-
                                     encounter rate in bears/season.
eio...............................  Inland open water season bear-
                                     encounter rate in bears/season.
eci...............................  Coastal ice season bear-encounter
                                     rate in bears/season.
eii...............................  Inland ice season bear-encounter
                                     rate in bears/season.
ti................................  Ice season harassment rate.
Bt................................  Number of estimated Level B
                                     harassment events.
------------------------------------------------------------------------

    The variables defined above were used in a series of formulas to 
ultimately estimate the total harassment from surface-level 
interactions. Encounter rates were originally calculated as polar bears 
encountered per square kilometer per season. As a part of their 
request, Narwhal provided the FWS with geospatial files indicating the 
location of all proposed ice roads, ice pads, tundra travel, vessel 
routes, staging areas, and SHS. The request also included the percent 
of time each component of the specified activities would be occupied by 
humans. These files were buffered by 1.6 km (1 mi) to calculate the 
area of disturbance.
    Impact areas were multiplied by the appropriate encounter rate to 
obtain the number of polar bears expected to be encountered in an area 
of interest per season (Bes). The equation below (equation 1) provides 
an example of the calculation of polar bears encountered in the ice 
season for an area of interest in the coastal zone.
Equation 1
Bes = ac * eci

    To generate the number of estimated Level B harassments for each 
area of interest, we multiplied the number of polar bears in the area 
of interest per season by the proportion of the season the area is 
occupied, the rate of occupancy, and the harassment rate (equation 2).
Equation 2
Bt = Bes * Sp * ro * ti

Aircraft Impacts on Polar Bears

    Polar bears in the project area will likely be exposed to the 
visual and auditory stimulation associated with the applicant's fixed-
wing and helicopter activities; however, these impacts are likely to be 
minimal and short-term. Aircraft activities may cause disruptions in 
the normal behavioral patterns of polar bears as either an auditory or 
visual stimulus, thereby resulting in incidental Level B harassment. To 
reduce the likelihood that polar bears are disturbed by aircraft, 
Narwhal has committed to multiple mitigation measures, such as minimum 
flight altitudes over polar bears, avoiding known areas of polar bear 
congregations, and restrictions on sudden changes to aircraft movements 
and direction. Once mitigated, such disturbances 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 30 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

[[Page 33994]]

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 following five categories of 
flights: take-offs, landings, low-altitude flights (defined as those 
between 122 m [400 ft] and 305 m [1,000 ft] altitude), mid-altitude 
flights (defined as those between 305 m [1,000 ft] and 457 m [1,500 ft] 
altitude), and high-altitude flights (defined as those between 457 m 
[1,500 ft] and 610 m [2,000 ft] altitude). Harassment rates were 
assigned to each of these flight categories using the harassment rate 
for the lowest altitude in the category (e.g., for low-altitude 
flights, the harassment rate estimated for 122 m [400 ft] was used). 
This binning method of using the lowest altitude harassment rate in the 
bin allowed our estimates to be inclusive of possible changes in 
altitude due to variable flight conditions (table 4).

 Table 4--Harassment Rates for the Five Categories of Flights for Fixed-
                Wing Aircraft and Helicopter Overflights
------------------------------------------------------------------------
                Flight category                  Fixed-wing   Helicopter
------------------------------------------------------------------------
Take-offs.....................................         0.99        >0.99
Landings......................................         0.99        >0.99
Low-Altitude Flights (122-305 m)..............         0.86        >0.99
Mid-Altitude Flights (305-457 m)..............         0.03         0.82
High-Altitude Flights (457-610 m).............        <0.01         0.05
------------------------------------------------------------------------
Note: The rates in this table are based on Quigley et al. (2024). We
  used the harassment rate associated with 30 m (100 ft) for take-offs
  and landings.

Estimating Area of Impact for Aircraft Activities

    For each category of the flight path (i.e., take-off, low-altitude 
travel, mid-altitude travel, high-altitude travel, and landing), we 
calculated an impact area and duration of impact using flight hours or 
flight path information provided in the Request. We used flights logs 
available through FlightAware (), 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) that would be impacted for 10 minutes. 
We estimated a landing distance of 4.83 km (3 mi) per 305 m (1,000 ft) 
of altitude that would be impacted for 10 minutes per landing. To 
estimate the impact area of traveling segments, we subtracted the take-
off and landing areas from the total area of the flight path. The 
duration of impact for traveling flights was either provided in the 
Request or calculated using the length of the flight and a conservative 
flight speed of 129 km/h (80 mph), which was approximately 1.5 minutes 
per 3.22 km (2 mi) of the flight path.
    All take-offs, landings, and traveling segments were then spatially 
referenced to determine whether they were within the coastal or inland 
zones. The coastal zone is defined as the offshore and onshore areas 
within 2 km (1.2 mi) of the coastline, and the inland zone is defined 
as the onshore area greater than 2 km (1.2 mi) from the coastline. If 
no location or flight hour information was provided, flight paths were 
approximated based on the information provided in the Request. Of the 
flight paths that were described or addressed through assumptions, we 
marked the approximate flight path take-off and landing locations using 
ArcGIS Pro, and the flight paths were drawn. Once spatially referenced, 
all flight paths were buffered by 1.6 km (1 mi), which is consistent 
with aircraft surveys conducted by the FWS and U.S. Geological Survey 
(USGS) between August and October during most years from 2000 to 2014 
(Schliebe et al. 2008; Atwood et al. 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, low-altitude 
travel, mid-altitude travel, high-altitude travel, and landings) for 
each zone and season combination. These values were then used to 
calculate the proportion of the season that aircraft occupied their 
impact areas (i.e., take-off area, landing area, or traveling segment 
impact areas). This proportion-of-season metric is equivalent to the 
occupancy rate (ro) generated for surface-level interaction harassment 
estimates. The total impact area for each of the flight categories was 
multiplied by the zone and season-specific polar bear encounter rate 
(table 5) to determine the number of polar bears expected in that area 
for the season (i.e., Bes, as seen in equation 1). This number was then 
multiplied by the proportion of the season to determine the number of 
polar bears expected in that area when flights are occurring, and the 
appropriate harassment rate based on flight altitude to estimate the 
number of polar bears that may be harassed as a result of the flights 
(as seen in equation 2). Table 6 shows a summary of aircraft operations 
during the specified activities and the values used to estimate Level B 
harassment of polar bears during aircraft operations.

          Table 5--Seasonal Polar Bear Encounter Rates by Zone
------------------------------------------------------------------------
 
------------------------------------------------------------------------
                  Coastal Zone Seasonal Encounter Rate
------------------------------------------------------------------------
Ice Season (November 12-July 18)................  0.05 bears/km\2\

[[Page 33995]]

 
Open-water Season (July 19-November 11).........  1.48 bears/km\2\
------------------------------------------------------------------------
                   Inland Zone Seasonal Encounter Rate
------------------------------------------------------------------------
Ice Season (November 12-July 18)................  0.004 bears/km\2\
Open-water Season (July 19-November 11).........  0.005 bears/km\2\
------------------------------------------------------------------------
Note: This table is adapted from the 2021-2026 Beaufort Sea ITR (86 FR
  42982, August 5, 2021).

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 two bear (table 6).

  Table 6--Estimated Level B Harassment of Polar Bears in Project Area by Year as a Result of Aircraft Operations During the Proposed Regulatory Period
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                              Ice season                                                Open-water season
                              --------------------------------------------------------------------------------------------------------------------------
           Activity                Startup crew                            Barge caretaker                                              Summer clean-up
                                     support        Operational support        resupply           Lake survey     Archaeology survey   and stick picking
--------------------------------------------------------------------------------------------------------------------------------------------------------
Aircraft type................  Helicopter.........  Fixed wing.........  Helicopter.........  Helicopter........  Helicopter........  Helicopter.
Altitude *...................  Low................  High...............  Low................  Low...............  Low...............  Low.
Total Flights................  4..................  137................  22.................  10................  3.................  6.
Proportion of Season.........  0.0007.............  0.0326.............  0.0040.............  0.0109............  0.0032............  0.0130.
Proportion of Flight in        0.33...............  0.38...............  0.33...............  0.26..............  0.38..............  0.35.
 Coastal Zone.
Proportion of Flight in        0.67...............  0.62...............  0.67...............  0.74..............  0.62..............  0.65.
 Inland Zone.
Total Encounter Rate (bears/   0.019..............  0.021..............  0.492..............  0.389.............  0.566.............  0.521.
 km\2\/season) **.
Harassment Rate..............  0.99...............  0.05...............  0.99...............  0.99..............  0.99..............  0.99.
Flight Time Harassment.......  1.14 x 10-\04\.....  2.85 x 10-\04\.....  1.60 x 10-\02\.....  3.42 x 10-\02\....  1.49 x 10-\02\....  5.48 x 10-\02\.
Total Takeoffs and Landings    8..................  274................  44.................  136...............  24................  120.
 combined.
Landing Time/Season..........  0.00011............  0.00381............  0.00133............  0.00412...........  0.00073...........  0.0036.
Landing Time Harassment......  0.00013............  0.00446............  0.04627............  0.03754...........  0.02515...........  0.1257.
Takeoff Time/Season..........  0.00011............  0.00381............  00.00133...........  0.00412...........  0.00073...........  0.0036.
Takeoff Time Harassment......  8.75 x 10-\05\.....  0.00300............  0.03108............  0.02521...........  0.01689...........  0.0844.
Number Level B Harassment of   0.00033............  0.00774............  0.09340............  0.09691...........  0.05690...........  0.2650.
 Activity.
                              --------------------------------------------------------------------------------------------------------------------------
    Total number of Level B                        1
     harassments during Ice
     Season.
                                  Total number of Level B harassments
                                           during Open Season
                                                   1
                              --------------------------------------------------------------------------------------------------------------------------
    Total number of level B harassments across all aircraft a2tivities......................
--------------------------------------------------------------------------------------------------------------------------------------------------------
* High-altitude flight is defined as between 457 m [1,500 ft] and 610 m [2,000 ft] altitude. Low altitude is defined as between 122 m [400 ft] and 305 m
  [1,000 ft] altitude. There are no mid-altitude flights considered for this project.
** Accounts for unequal encounter rates over coastal and inland zones.

Denning Analysis

    Below we provide a complete description, and results of the polar 
bear den simulation model used to assess impacts to denning polar bears 
from disturbance associated with all phases of the specified 
activities. In our denning analysis, we used the analytical method 
described in the 2024-2025 Bureau of Land Management Incidental 
Harassment Authorization (BLM IHA) (90 FR 2718, January 13, 2025).

Den Simulation

    We simulated dens across the entire North Slope of Alaska, ranging 
from the areas identified as denning habitat (Durner et al. 2006, 2013; 
Durner and Atwood 2018) contained within the National Petroleum 
Reserve-Alaska (NPR-A) in the west to the Canadian border in the east. 
To simulate dens on the landscape, we relied on the estimated number of 
dens in three different regions of northern Alaska provided by Atwood 
et al. (2020). These included the NPR-A, the area between the Colville 
and Canning Rivers (CC), and Arctic National Wildlife Refuge (NWR). Den 
simulations for this proposed IHA were conducted following the exact 
methodology described previously in the 2024-2025 BLM IHA (90 FR 2718, 
January 13, 2025).

Impact Area of Specified Activities

    The model developed by Wilson and Durner (2020) provides a template 
for estimating the level of potential impact on denning polar bears 
during the specified activities while also considering the natural 
denning ecology of polar bears in the region. Previous iterations of 
the denning analysis model, including those utilized in the 2021-2026 
Beaufort Sea ITR (86 FR 42982, August 5, 2021) and 2023-2024 BLM IHA 
(88 FR 88943, December 26, 2023), assumed that during all denning 
periods, any polar bears within dens within 1.6 km (1 mi) from project 
activities could exhibit a disturbance response if exposed to 
industrial stimuli. However, for this IHA, as in the 2024-2025 BLM IHA 
(90 FR 2718, January 13, 2025), we refined that broad assumption to 
account for denning data that have been collected subsequent to the 
promulgation of the 2021-2026 Beaufort Sea ITR. Since 2021, four known 
dens (monitored in 2022 and 2023) have occurred near human activity. Of 
the four newly observed dens, three were extremely close to human 
activity (<50 m [<164 ft]), yet the sows remained in their dens until 
the late denning period. We updated polar bear disturbance 
probabilities and litter size distributions with the information from 
these dens, then re-examined the historic dens that were used to create 
disturbance probabilities. We found that the distances between human 
activity and polar bear dens during the early

[[Page 33996]]

denning period were considerably closer than those observed during 
other denning periods. Specifically, of the 17 dens within the case 
studies that were exposed to human activity during the early denning 
period, only one was potentially disturbed at a distance greater than 
800 m (2,625 ft). This single den record also had imprecise information 
on the distance to human activity, so activity was assumed to occur 
within 1,610 m (5,282 ft) of the den and was likely closer. The 
historic dens analyzed during the den establishment, late denning, and 
post-emergence periods did not follow this pattern. For those dens, 
disturbance distances commonly exceeded 805 m (2,641 ft). Evidence 
derived from dens exposed to human activity during the early denning 
period, including both new den records and historic dens, illustrates 
the reluctance of sows to abandon their maternal den/cubs in response 
to exposure to stimuli from nearby activity, and supports the concept 
that sows may be more risk tolerant during the early denning period. 
Additionally, sows may be less affected by sound from outside 
activities during the early denning period because dens are typically 
closed during that time, which can affect propagation of noise into the 
den (Owen et al. 2020). Given this evidence, we modified the denning 
analysis model to adjust the impact area for the early denning period 
to range from 0 to 805 m (0 to 2,641 ft). As a result, dens that were 
simulated to be within 805 m (2,641 ft) of human activity could be 
disturbed during all denning periods, while dens between 806 and 1610 m 
(2,644 and 5,282 ft) away from human activity could only be disturbed 
during the den establishment, late denning, and post-emergence periods.

AIR Surveys

    We assumed that all operational and transit areas that will be 
utilized during denning season would have two AIR surveys flown prior 
to beginning any operations (figures 1 and 2). The first survey would 
occur between December 1 and December 25, 2025, and the second survey 
between December 15, 2025, and January 10, 2026, with a minimum of 24 
hours between surveys. During each iteration of the model, each AIR 
survey was randomly assigned a probability of detecting dens using 
detection probabilities previously described in the 2024-2025 BLM IHA 
(90 FR 2718, January 13, 2025).

Model Implementation

    For each iteration of the model, we first determined which dens 
were exposed to the specified activities. Dens that were simulated to 
be within 805 m (2,641 ft) of human activity could be disturbed during 
all denning periods, while dens within 806-1610 m (2,644-5,282 ft) of 
human activity could only be disturbed during the den establishment, 
late denning, and post-emergence periods. Dens detected during AIR 
survey were excluded if activity did not occur prior to AIR survey. We 
identified the stage in the denning period when the exposure occurred 
based on the date range of the activities the den was exposed to: den 
establishment (i.e., initial entrance into den until cubs are born), 
early denning (i.e., birth of cubs until they are 60 days old), late 
denning (i.e., date cubs are 60 days old until den emergence) and post-
emergence (i.e., the date of den emergence until permanent departure 
from the den site). We then determined whether the exposure elicited a 
response by the denning polar bear based on probabilities derived from 
the reviewed case studies (Woodruff et al. 2022b), which were updated 
with data from the dens monitored in 2022 and 2023 using the methods 
described in Woodruff et al. (2022a).
    Specifically, we divided the number of cases that documented 
responses associated with either a Level B harassment (i.e., potential 
to cause a disruption of behavioral patterns), Level A harassment 
(i.e., potential to injure an animal), or lethal take (e.g., cub 
abandonment) of polar bears by the total number of cases with that 
combination of period and exposure type (table 7). Level B harassment 
was applicable to both adults and cubs, if present, whereas Level A 
harassment and lethal take were applicable to only cubs. AIR surveys 
were not considered to be a source of potential impact. In thousands of 
hours of AIR surveys conducted in northern Alaska over the last decade, 
we are not aware of a single instance of a polar bear abandoning its 
den during the early denning period due to an AIR survey overflight. 
These responses would be readily observable on the thermal cameras, and 
the fact that none have been observed indicates that den abandonment 
very likely does not occur given the brief duration of the aircraft 
overflight as well as the distance and altitude of the aircraft from 
the den site. Recent peer-reviewed research further supports the model 
assumption that AIR surveys are not a source of harassment (Quigley et 
al. 2024).
    For dens exposed to activity, we used a multinomial distribution 
with the probabilities of different levels of take for that period 
(table 7) to determine whether a den was disturbed or not. If a lethal 
take was simulated to occur, a den was not allowed to be disturbed 
again during the subsequent denning periods because the outcome of that 
denning event was already determined.
    The level of impact associated with a disturbance varied according 
to the severity and timing of the exposure (table 7). Exposures that 
resulted in emergence from dens prior to cubs reaching 60 days of age 
were considered lethal takes of cubs. If an exposure resulted in a 
Level A harassment during the late denning period, we first assigned 
that den a new random emergence date from a uniform distribution that 
ranged between the first date of exposure during the late denning 
period and the original den emergence date. We then determined whether 
that den was disturbed during the post-emergence period, but the 
probability of disturbance was dependent on whether or not a den was 
disturbed (i.e., Level A harassment) during the late denning period 
(table 7). If an exposure resulted in a Level A harassment during the 
post-emergence period, we assigned the den a new time spent at the den 
site post-emergence from a uniform distribution that ranged from 0 to 
the original simulated time at the den post-emergence.
    Recent research suggests that litter survival is related to the 
date of den emergence and time spent at the den post-emergence 
(Andersen et al. 2024), with litters having higher survival rates the 
later they emerge in the spring, and the longer they spend at the den 
site after emergence. To determine if whether dens that were disturbed 
during the late denning and/or post-emergence period(s) experienced 
Level A harassment, we relied on estimates of litter survival in the 
spring following den emergence, derived from the analysis of empirical 
data on the dates of emergence from the den and departure from the den 
site (Andersen et al. 2024). These estimates are dependent on the date 
of emergence and time spent at the den site post-emergence. For each 
den disturbed during the late denning and/or post-emergence periods, we 
obtained a random sample of regression coefficients from the posterior 
distribution and calculated the probability of a litter surviving 
approximately 100 days post-emergence with the following equation:
Equation 3
logit(s) = [beta]0 + [beta]1emerge + 
[beta]2depart

where s is the probability of at least one cub being alive 
approximately 100 days post-emergence, [beta]0 is the 
intercept coefficient, [beta]1 is the coefficient associated 
with the Julian date of

[[Page 33997]]

emergence (emerge), and [beta]2 is the coefficient 
associated with the number of days the family group stayed at the den 
site post-emergence before departing (depart). These probabilities are 
based on estimates of litter survival derived from the analysis of 
empirical data on the dates of emergence from the den and departure 
from the den site (Andersen et al. 2024).

    We developed the code to run this model in program R (R Core 
Development Team 2020) and ran 10,000 iterations of the model (i.e., 
Monte Carlo simulation) to derive the estimated number of dens 
disturbed and associated levels of harassment. We then determined the 
number of cubs that would have lethal take, Level A harassment, and 
Level B harassment, and the number of females that would experience 
Level B harassment. Table 7 shows the probability of an exposure 
resulting in the types of harassment of denning polar bears.

  Table 7--Probability That an Exposure Elicited a Response by Denning Polar Bears That Would Result in Level B
                             Harassment, Level A Harassment, Lethal Take, or No Take
----------------------------------------------------------------------------------------------------------------
                                  None (sow or                        Level B         Level A         Lethal
        Denning period               cub(s))       Level B (sow)     (cub(s))        (cub(s))        (cub(s))
----------------------------------------------------------------------------------------------------------------
Den Establishment.............             0.750           0.250           0.000           0.000           0.000
Early Denning.................             0.923           0.077           0.000           0.000           0.077
Late Denning..................             0.684           0.316           0.000           0.316           0.000
Post Emergence--Previously                 0.000           1.000           0.316           0.684           0.000
 Undisturbed Den..............
Post Emergence--Previously                 0.000           1.000           0.667           0.333           0.000
 Disturbed Den................
----------------------------------------------------------------------------------------------------------------
Note: Level B harassment was applicable to both adults 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 the cubs. During the early denning period, there was no Level A harassment for cubs, only lethal
  take. We provide two sets of take probabilities for the post-emergence period. The first (Post-emergence--
  Undisturbed) is the set of probabilities when a den has not been disturbed during the late denning period. The
  second (Post-emergence-Disturbed) is the set of probabilities for a den that was disturbed during the late
  denning period (Rode et al. 2018; Andersen et al. 2024).

Model Results

    In the denning model both sows and cubs may experience Level B 
harassment, however, only cubs can experience either Level A harassment 
or lethal take (see Model Implementation and table 7 for further 
detail). The distributions of model results for Level B harassments, 
Level A harassments, and Lethal takes, were non-normal and heavily 
skewed. The heavily skewed nature of these distributions suggests that 
the mean value is not representative of the most common model result. 
Therefore, mean is not an appropriate measure of potential denning 
related harassments. However, the median value, which is the midpoint 
value of a frequency distribution of all model results, is a more 
precise estimator of common model results when the distribution 
displays a non-normal and heavily skewed pattern. In all three take 
scenarios, Level B harassment, Level A harassment, and Lethal take, the 
median value was zero (0), with 95 percent confidence intervals ranging 
between 0-2 for both Level B and Level A harassment, and from 0-1 for 
Lethal take (table 8). Table 8 also shows the probability of Level B 
harassment was the highest (0.220), followed by Level A harassment 
(0.123), lowest for lethal take (0.018). As a result of these model 
outputs, we anticipate zero (0), and therefore do not authorize any, 
Level B harassment, Level A harassment, or Lethal take associated with 
denning polar bears during the 1-year period of this proposed IHA.

             Table 8--Results of the Den Disturbance Model for Any Given Winter of Proposed Activity
----------------------------------------------------------------------------------------------------------------
                                                                            Estimates *
            Level of harassment/take             ---------------------------------------------------------------
                                                    Probability        Mean           Median          95% CI
----------------------------------------------------------------------------------------------------------------
Level B Harassment..............................            0.22            0.28               0             0-2
Level A Harassment..............................            0.12            0.23               0             0-2
Lethal Take.....................................            0.02            0.03               0             0-1
----------------------------------------------------------------------------------------------------------------
Note: * Estimates are provided for the probability, mean, median, and 95 percent Confidence Intervals (CI) for
  Level B harassment, Level A harassment, and Lethal take. The probabilities represent the probability of >=1
  take of a bear occurring during a given winter.

Maritime Activities

    Narwhal's specified activities include maritime transport of 
personnel and equipment (i.e., barging and resupply) and activities to 
actively survey the project area (i.e., bathymetric and -high-
resolution 3D seismic surveys). The bathymetric and seismic surveys 
will introduce sound into the water as described in this Proposed IHA 
under ``Description of Specified Activities and Specified Geographic 
Region''. Except for the 1,721-cm\3\ (105-in\3\) airgun that will be 
used in the high-resolution 3D seismic surveys, the equipment will 
either produce sound at a frequency outside of the hearing range of 
polar bears, or in an extremely directed and narrow area. Narwhal has 
indicated the airgun will create impulsive noise at approximately 231.0 
dB re 1[micro]Pa peak SPL, and its use will result in >=160 dB re 
1[micro]Pa noise in an area up to 3,188 m (10,459 ft) surrounding the 
sound source. As described in ``Potential Impacts of the Specified 
Activities on Marine Mammals,'' polar bears experiencing underwater 
noise >= 160 dB re 1[micro]Pa may exhibit behavioral responses that are 
indicative of Level B harassment. However, polar bears rarely swim with 
their heads under water unless diving or actively hunting. We do not 
anticipate polar bears to be actively diving or hunting within 3,188 m 
(10,459 ft) of survey vessels in the water. Thus, we do not estimate 
that harassment due to ensonification will occur as a result of the 
specified activities. However, the applicant has included in their 
request the estimated harassment of polar bears through behavioral 
change in response to in-water sound.

[[Page 33998]]

    We estimated the number of polar bears that may exhibit Level B 
harassment resulting from interactions with vessel traffic in a manner 
similar to that used to generate aircraft disturbance estimates. 
Narwhal has supplied the highest expected number of trips that may be 
taken during specified activities, including placement of staging 
barges and resupply of summer surveys in West Harrison Bay. While 
resupply trips may originate from West Dock in Prudhoe Bay or from 
Oliktok Point, we conservatively used the longer trip originating from 
West Dock in harassment estimates. The impact area of the barge/tug 
combination moves in its route from one location to the next. We 
estimated a 16.5-km\2\ (6.37-mi\2\) take area for vessels, which 
accounts for the greatest footprint anticipated, that of a barge, tow, 
and tug with a length of 200 m (656 ft) and a width of 100 m (328 ft), 
and a 1.6-km (1-mi) buffer surrounding the vessels. When a finite 
number of trips was supplied, we calculated the total hours of impact 
using an average vessel speed of two knots (3.7 km/hr). Polar bears are 
known to spend a biologically consequential portion of their time in 
coastal waters (Stirling 1974; Lone et al. 2018) and no polar bear-
specific study has been conducted to establish an in-water only 
encounter rate. Furthermore, bear densities likely vary spatially from 
near shore to deeper waters. Therefore, we used the same coastal zone 
seasonal encounter rates for the open water season as described in 
``Estimating Area of Impact for Aircraft Activities'' to conduct our 
vessel analysis. The hours of impact were then used to calculate the 
proportion of the open-water season that would be impacted (table 9). 
We acknowledge that the coastal zone seasonal encounter rate is a 
conservative estimate for an in-water encounter rate, especially for 
deeper offshore waters. However, without data developed specifically 
for an estimation of polar bears in-water densities it presents the 
best available data.

Table 9--Calculation of the Total Number of Barge and Tug Vessel Trip Hours and the Proportion of the Season Polar Bears May Be Impacted in a 16.5-km\2\
                                                            Impact Area by Barge/Tug Presence
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                     Hours per  Number of
                          Vessel activity                              day or    days or    Area of    Proportion   Encounter   Harassment    Number of
                                                                       event      events     impact    of season      rate         rate      harassments
--------------------------------------------------------------------------------------------------------------------------------------------------------
Barge Deployment...................................................        119     1 trip  132 km\2\         0.04        1.48         0.19           1.6
Resupply Vessels from West Dock....................................         39   45 trips       16.5         0.62        1.48         0.19           2.9
                                                                                               km\2\
Bathymetry Vessels.................................................         12    18 days   33 km\2\         0.07        1.48         0.19           0.7
High Resolution Seismic Support Vessel.............................         12    30 days       49.5         0.13        1.48         0.19           1.8
                                                                                               km\2\
High Resolution Seismic Source Vessels.............................         12    30 days       24.4         0.13        1.48         0.19           0.9
                                                                                               km\2\
                                                                    ------------------------------------------------------------------------------------
    Total Estimated Level B Harassments............................  .........  .........  .........  ...........  ..........  ...........           7.9
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The number of estimated takes was then calculated using equation 2, 
in which the impact area is multiplied by encounter rate, proportion of 
season, and harassment rate for the open-water season. The final number 
of estimated Level B harassment events from barge/tug trips and 
potential interactions between seismic vessels and polar bears was 7.9, 
rounded to eight polar bears for the duration of activities.

Sum of Take From All Sources

    The applicant proposes to conduct SHS, preliminary field surveys, 
exploratory drilling operations, and summer cleanup activities in West 
Harrison Bay, Alaska, from August 1, 2025, through July 31, 2026. A 
summary of total estimated take for both walruses and polar bears via 
Level B harassment during the project by source is provided in table 
10. Neither lethal take nor Level A harassment would occur outside of 
denning polar bears because the level of sound and visual stimuli 
experienced by polar bears on the surface or in the water would not be 
significant enough to result in injury or death. Denning polar bears, 
however, may be subject to repeated exposures, significant energy 
expenditure from den abandonment or departure, or potential impacts to 
a cub if the den is abandoned or departed prematurely. The probability 
of greater than or equal to one Level A harassment or lethal take is 
0.171 and 0.032, respectively. As a result of these model outputs, we 
do not anticipate nor authorize any Level B harassment, Level A 
harassment, or Lethal take associated with denning polar bears during 
the 1-year period of this proposed IHA.

Table 10--Total Estimated Takes by Level B Harassment of Polar Bears and
                       Pacific Walruses by Source
------------------------------------------------------------------------
                                                              Number of
                                                              estimated
                          Source                               Level B
                                                             harassments
------------------------------------------------------------------------
                               Polar bears
------------------------------------------------------------------------
Bears on the surface......................................             3
Vessel activities.........................................             8
Winter activities--Denning bears..........................             0
Aircraft activities.......................................             2
                                                           -------------
    Polar bear total......................................            13
------------------------------------------------------------------------
                            Pacific walruses
------------------------------------------------------------------------
Vessel activities.........................................            15
    Pacific walrus total..................................            15
------------------------------------------------------------------------

Critical Assumptions

    In order to conduct this analysis and estimate the potential amount 
of Level B harassment, several critical assumptions were made.
    Level B harassment is equated herein with behavioral responses that 
indicate harassment or disturbance. There is likely a portion of 
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 specified 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

[[Page 33999]]

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.
    The SBS polar bears do create maternal dens on the sea ice, and the 
specified activities may occur on sea ice close to the shoreline. The 
den simulation used in our analysis does not simulate dens on the sea 
ice. However, the portions of the sea ice that may be impacted by the 
specified activities are shore-fast ice, which does not typically move 
in a way that creates pressure ridges needed to create sufficient 
denning habitat.

Determinations and Findings

    In making these findings, we considered the best available 
scientific information, including: the biological and behavioral 
characteristics of the species; the most recent information on species 
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 
marine mammals to this disturbance. In addition, we reviewed applicant-
provided materials; information in our files and datasets, published 
reference materials, and information provided by species experts.

Small Numbers

    For our small numbers determination, we consider whether the 
estimated number of polar bears and Pacific walruses to be subjected to 
incidental take are respectively small relative to the population size 
of the species or stock.
    1. As stated previously, walruses are extralimital in the Beaufort 
Sea, with nearly the entire walrus population found in the Chukchi and 
Bering Seas. Industry monitoring reports have observed no more than 49 
walruses between 1995 and 2023, with only a few observed instances of 
disturbance to those walruses (AES Alaska 2015; USFWS unpublished 
data). Between those years, observations were typically of a single or 
two animals, often separated by several years. At most, only a tiny 
fraction of the Pacific walrus population--which is comprised of 
hundreds of thousands of animals (Beatty et al. 2022)--may be found in 
areas potentially affected by Narwhal's specified activities. We do not 
anticipate that seasonal movements of a few walruses into the Beaufort 
Sea will significantly increase over the 1-year period of this IHA. The 
estimated take of 15 Pacific walruses per year from a population 
numbering approximately 257,193 animals represents 0.005 percent of 
that population ((15 / 257,193) x 100 [ap] 0.005 percent). We therefore 
find that the industry activities specified in Narwhal's request would 
result in only a small number of incidental harassments of walruses.
    We estimate that Narwhal's proposed specified activities in the 
specified geographic region will cause no more than harassment (Level 
B) to 13 polar bears during the 1-year period of this proposed IHA (see 
Sum of Take from All Sources). Take of 13 animals is 1.4 percent of the 
best available estimate of the current SBS stock size of 907 animals 
(Bromaghin et al. 2015; Atwood et al. 2020; ((13 / 907) x 100 [ap] 1.4 
percent) and represents a ``small number'' of polar bears of that 
stock.
    2. The footprint of the specified activities within the specified 
geographic region is small relative to the range of the Pacific walrus 
and the SBS stock of polar bear. Walruses and SBS polar bears range 
well beyond the boundaries of the proposed IHA region. As such, the IHA 
region itself represents only a subset of the potential area in which 
these species may occur. Thus, the FWS concludes that a small portion 
of the Pacific walrus and SBS polar bear populations may be present in 
the specified geographic region during the time of the specified 
activities.

Small Number Conclusion

    We propose a finding that take of up to 15 Pacific walrus and 13 
SBS polar bears represents a small number of each stock.

Negligible Impact

    For our negligible impacts determination, we consider the 
following:
    1. The documented impacts of previous activities similar to the 
specified activities on Pacific walruses and polar bears, and, taking 
into consideration the baseline of existing impacts from factors such 
as oil and gas activities in the area and other ongoing or proposed 
incidental take authorizations, suggests that the types of specified 
activities will have minimal effects on Pacific walruses and polar 
bears. Additionally, the effects will be limited to short-term, 
temporary behavioral changes, or minor injury. Furthermore, our 
analyses do not indicate, nor do we anticipate, any take by Level A 
harassment or lethal take of either Pacific walruses or polar bears 
during the 1-year period of this proposed IHA. Therefore, we anticipate 
that the specified activities will not have lasting impacts that could 
significantly affect an individual Pacific walrus or polar bear's 
health, reproduction, or survival. The limited extent of anticipated 
impacts on Pacific walruses and polar bears--i.e., temporary and minor 
behavioral disturbances associated with Level B harassment--is unlikely 
to adversely affect annual rates of Pacific walrus or polar bear 
survival or recruitment.
    2. The distribution and habitat use patterns of Pacific walruses 
and polar bears indicate that relatively few Pacific walrus and polar 
bears will occur in the specified areas of activity at any time and, 
therefore, few Pacific walruses and polar bears are likely to be 
affected.
    3. Narwhal has committed to the implementation of monitoring 
requirements and mitigation measures designed to reduce the potential 
impacts of their operations on Pacific walruses and polar bears. Den 
detection surveys for polar bears, along with, adaptive mitigation and 
management responses based on real-time monitoring information 
(described in this proposed authorization) will be used to avoid or 
minimize interactions with either Pacific walruses or polar bears and, 
therefore, limit potential disturbance of these species.
    We also consider the conjectural or speculative impacts associated 
with these specified activities. The specific congressional direction 
described below justifies balancing the probability of such impacts 
with their severity: If potential effects of a specified activity are 
conjectural or speculative, a finding of negligible impact may be 
appropriate. A finding of negligible impact may also be appropriate if 
the probability of occurrence is low, but the potential effects may be 
significant. In this case, the probability of occurrence of impacts 
must be balanced with the potential severity of harm to the species or 
stock when determining negligible impact. In applying this balancing 
test, the FWS will thoroughly evaluate the risks involved and the 
potential impacts on marine mammal populations. Such determination will 
be made based on the best available scientific information (54 FR 
40338, September 29, 1989, quoting 53 FR 8473, March 15, 1988, and 132 
Cong. Rec. S 16305 (October 15, 1986)).
    The potential effects of most concern here, specific to polar 
bears, is the mortality of polar bear cubs that could result from 
disturbances during certain periods of the denning season. The FWS 
estimated that the probability of greater

[[Page 34000]]

than or equal to one lethal take that is likely to result in the 
mortality of a denning polar bear is zero within the 1-year period of 
this proposed IHA. Therefore, the FWS does not anticipate any lethal 
take will occur during the IHA period. If a den is disturbed and lethal 
take were to occur, this take would be limited to only cubs during the 
denning period. Denning females, the demographic group most important 
to annual recruitment, are limited to take by Level B harassment. 
Therefore, the number of potentially available reproductive females 
that would contribute to recruitment for the SBS stock would remain 
unaffected if a den disturbance were to result in the mortality of the 
cubs.
    The SBS stock of polar bears is currently estimated as 907 polar 
bears (Bromaghin et al. 2015, 2021; Atwood et al. 2020). The loss of 
one litter ranges from 0 percent (0 cubs) to approximately 0.33 percent 
(3 cubs) of the annual SBS stock size of polar bears (((0 cubs to 3 
cubs) / 907) x 100 [ap] 0 to 0.33). Cub litter survival was estimated 
at 50 percent (90 percent CI: 33-67 percent) for the SBS stock during 
2001-2006 (Regehr et al. 2010). A female may lose her litter for 
several reasons separate from den disturbance. The determining factor 
for polar bear stock growth is adult female survival (Eberhardt 1990). 
Consequently, the loss of female cubs has a greater impact on annual 
recruitment rates for the SBS stock of polar bears compared to male 
cubs. If a den disturbance were to result in the mortality of the 
entire litter, the female would be available to breed during the next 
mating season and could produce another litter during the next denning 
season.
    Based on our projected zero cub mortality associated with these 
specified activities, and the recognition that even if a den is 
disturbed, the number of potentially affected cubs would be minimal and 
the number of reproductive females in the stock would remain the same, 
the FWS does not anticipate that the conjectural or speculative impacts 
associated with these specified activities warrant a finding of non-
negligible impact or otherwise preclude issuance of this proposed IHA. 
The potential effects of greatest concern to walrus are associated with 
human-induced stampedes at walrus coastal haulout sites. Hauled out 
walruses tend to be in close physical contact, with groups ranging from 
a few animals up to tens of thousands of individuals--the largest 
aggregations occurring at land haulouts (Gilbert 1999, Monson et al. 
2013, USFWS 2017). Intra-specific trauma at coastal haulouts is a known 
source of injury and mortality (Garlich-Miller et al. 2011). The risk 
of stampede-related injuries increases with the number of animals 
hauled out and with the duration spent on coastal haulouts. Calves and 
young are the most vulnerable to suffer injuries and/or mortality 
(USFWS 2017). There has never been a reported large coastal haulout 
site located in the South Beaufort Sea, nor is there any reason to 
suspect a large coastal haulout may occur in the near future given the 
extremely low density and transient nature of walrus in the region. 
Therefore, the FWS does not anticipate that the conjectural or 
speculative impacts associated with these specified activities warrant 
a finding of non-negligible impact or otherwise preclude issuance of 
this proposed IHA.
    We reviewed the effects of the specified activities on polar bears, 
including impacts from surface interactions, aircraft overflights, and 
den disturbance. We also reviewed the effects of the specified 
activities on Pacific walruses including vessel activity, which is the 
primary source of potential exposure during the specified activities. 
Based on our review of these potential impacts, past monitoring 
reports, and the biology and natural history of polar bears, we 
anticipate that such effects will be limited to short-term behavioral 
disturbances.
    We have evaluated climate change regarding Pacific walruses and 
polar bears as part of the environmental baseline. Climate change is a 
global phenomenon and was considered as the overall driver of effects 
that could alter Pacific walrus and polar bear habitat and behavior. 
The FWS is currently involved in research to understand how climate 
change may affect Pacific walruses and polar bears. As we gain a better 
understanding of climate change effects, we will incorporate the 
information in future authorizations.
    We find that the impacts of these specified activities cannot be 
reasonably expected to, and are not reasonably likely to, adversely 
affect either Pacific walruses or SBS polar bears through effects on 
annual rates of recruitment or survival. We therefore find that the 
total of the taking estimated above and proposed for authorization will 
have a negligible impact on Pacific walruses and SBS polar bears.

Impact on Subsistence Use

    Based on past community consultations, locations of hunting areas, 
no anticipated overlap of hunting areas and industry projects, and the 
best scientific information available, including monitoring data from 
similar activities, we propose a finding that take caused by the 
specified activities will not have an unmitigable adverse impact on the 
availability of walruses or polar bears for taking for subsistence uses 
during the proposed timeframe.
    While walruses and polar bears represent a small portion, in terms 
of the number of animals, of the total subsistence harvest for the 
Utqiagvik, Nuiqsut, and Kaktovik communities, their harvest is 
important to Alaska Natives. The project activities are in close 
proximity to an established industrial area, with the closest known 
common polar bear harvest locations greater than 70 km (43.5 mi) away. 
Walrus harvest from Nuiqsut and Kaktovik is opportunistic, and none of 
the walrus harvests for Utqiagvik, Nuiqsut, or Kaktovik from 2014 
through 2022 have occurred within the area of specified activities. 
Narwhal has committed to notify the Village of Kaktovik and Village of 
Nuiqsut of the planned activities and document any discussions of 
potential conflict. Narwhal will make reasonable efforts to ensure that 
activities do not interfere with subsistence hunting and that adverse 
effects on the availability of walruses or polar bears are minimized. 
Should such a concern be voiced, Narwhal will develop a plan of 
cooperation (POC) that identifies measures to minimize any adverse 
effects. The POC will ensure that project 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 Narwhal will work with the affected Alaska Native communities and 
what actions will be taken to avoid interference with subsistence 
hunting of walruses or polar bears, as warranted.
    The FWS is not aware of information that indicates that walruses or 
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.

Least Practicable Adverse Impact

    We evaluated the practicability and effectiveness of mitigation 
measures based on the nature, scope, and timing of the specified 
activities; the best available scientific information; and monitoring 
data during industry activities in the specified geographic region. We 
propose a finding that the mitigation measures included within 
Narwhal's request will ensure least practicable adverse impacts on 
walruses and polar bears and also ensure no unmitigable adverse impacts 
to the

[[Page 34001]]

availability of polar bears or walruses for subsistence use.
    Polar bear den surveys at the beginning of the winter season; the 
resulting 805 m (0.5-mi) operational exclusion zone around all known 
polar bear dens, 24-hour monitoring of any den site located within the 
805 m buffer of activity; and restrictions on the timing and types of 
activities in the vicinity of dens will minimize impacts to denning 
female polar bears 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, Narwhal will 
implement mitigation measures to prevent the presence and impact of 
attractants in camps, such as the use of wildlife-resistant waste 
receptacles, daily food waste incineration, and storage of hazardous 
materials in drums or other secure containers. These measures are 
outlined in a polar bear interaction plan that was developed in 
coordination with the FWS and is part of Narwhal's application for this 
IHA. Based on the information we currently have regarding den and 
aircraft disturbance and polar bear attractants, we concluded that the 
mitigation measures outlined in Narwhal's request (ECO49 Consulting LLC 
2024) and incorporated into this authorization will minimize impacts 
from the specified SHS, preliminary field surveys, exploratory drilling 
operations, and summer cleanup activities to the extent practicable.
    Several additional potential mitigation measures were considered 
but determined to be not practicable. These measures are listed below:
     Required use of helicopters for AIR surveys--Use of 
helicopters to survey active dens might lead to greater levels of 
disturbance and take compared to fixed-wing aircraft. Additionally, 
there is no published data to indicate increased den detection efficacy 
of helicopter AIR.
     Grounding 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 possible, as some operations may require flying 
below 457 m (1,500 ft) to perform necessary inspections or maintain 
safety of flight crew. 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.
     Spatial and temporal restrictions on surface activity--
Some spatial and temporal restrictions of operations were included in 
Narwhal's request; however, imposing further restrictions would risk 
preventing the accomplishment of project objectives.
     One-mile buffer around all known polar bear denning 
habitat--Creating one-mile (1.6-km) buffers around all known polar bear 
denning habitat is not practicable, as much of Narwhal's proposed 
survey area occurs within 1.6 km (1 mi) of denning habitat; thus, to 
exclude all areas within 1.6 km (1 mi) of denning habitat would 
preclude surveys from occurring.
     One-mile exclusionary buffer around dens detected within 
project area--establishing a 1.6 km (1-mi) exclusionary buffer around 
located den sites was deemed impracticable due to: (1) potential 
conflict with ringed seal mitigation measures as required by the 
National Marine Fisheries Service (NMFS); (2) risks to human health and 
safety imposed by moving the sea ice road away from grounded sea ice; 
and (3) logistical impracticalities. However, Narwhal will establish an 
805 m (0.5 mi) exclusionary buffer around any dens located within the 
project area and provide 24-hour monitoring of a den site located 
within an exclusionary buffer. Narwhal's project activities utilize 
coastal areas that may overlap with both polar bear and ringed seal 
habitat. Travel routes will be conducted on grounded sea ice whenever 
possible. Should a den be discovered in the coastal area, a 1.6 km (1-
mi) buffer could force the travel route off of the grounded sea ice, 
which has the potential to disturb ringed seal layers and is in 
conflict with NMFS mitigation measures. Additionally, a road not on 
grounded sea ice may not be able to support the transit load, resulting 
in risks to human health and safety.
     Prohibition of driving over high-relief areas, 
embankments, or stream and river crossings--While the denning habitat 
must be considered during tundra travel, complete prohibition is not 
practicable for operational and safety reasons (e.g., not being able to 
access project areas or evacuating personnel via the fastest route 
possible in an emergency).
     Use of a broader definition of ``denning habitat'' for 
operational offsets--There is no available data to support broadening 
the defining features of denning habitat beyond that established by the 
USGS. Such a redefinition would cause an increase in the area surveyed 
for maternal dens, and the associated increase in potential harassment 
of polar bears on the surface would outweigh the mitigative benefits.
     Establishment of corridors for sow and cub transit to the 
sea ice--As there is no data to support the existence of natural 
transit corridors to the sea ice, establishment of corridors in the IHA 
area would be highly speculative. Therefore, there would be no 
mitigative benefit realized by their establishment.
     Requirement of third-party neutral marine mammal 
observers--The applicant has committed to the use of a dedicated lead 
marine mammal observer and other project personnel serving as 
designated marine mammal observers during high-resolution seismic 
surveys. However, operational constraints prevent the applicant from 
hiring third-party marine mammal observers for all operations due to 
space considerations. Additional crew may also require additional 
transit vehicles or larger vessels, which could increase disturbance.
     Require a mandatory shutdown or power-down if a polar bear 
or walrus enters the 160-dB ensonification zone--Vessels will avoid 
polar bears and walruses in the water to the extent practicable; 
however, the size of the Level B ensonification zone (3,188 m (10,459 
ft) from the sound source) created by the airgun is too big to 
effectively observe and a walrus or polar bear may enter the Level B 
zone without being seen. The Level A ensonification zones are so small 
(10 m (33 ft) or less from the sound source) that the sound pressure 
levels associated with Level A harassment are inside the vessel's 
footprint and would not be exceeded at any measurable distance from the 
source vessel.
     Require all activities to cease if a walrus or polar bear 
is injured or killed until an investigation is completed--The FWS has 
incorporated into this proposed authorization reporting requirements 
for all polar bear interactions. While it may aid in any subsequent 
investigation, ceasing all activities may not be possible or safe in 
certain circumstances, and thus will not be mandated.
     Require use of den detection dogs--It is not feasible or 
safe to require scent-trained dogs to detect dens due to the large 
spatial extent that would need to be surveyed within activity areas.
     Require the use of handheld or vehicle-mounted Forward 
Looking Infrared (FLIR)--The efficacy rates for AIR have been found to 
be four times more likely to detect dens than ground-based FLIR 
(handheld or vehicle-mounted FLIR) due to impacts of blowing snow on 
detection. Narwhal has incorporated into their mitigation measures the 
use of handheld or vehicle-mounted FLIR when transiting

[[Page 34002]]

rivers occurring in suitable denning habitat, but it is not practicable 
to use the equipment during all transit.

References Cited

    A list of the references cited in this notice may be found at 
 under Docket No. FWS-R7-ES-2025-0021.

Required Determinations

National Environmental Policy Act (NEPA)

    We have prepared a draft environmental assessment in accordance 
with the NEPA (42 U.S.C. 4321 et seq.). We have preliminarily concluded 
that authorizing the nonlethal, incidental, unintentional take by Level 
B harassment of up to 15 individuals from the Pacific walrus population 
and 13 individuals from the SBS stock of polar bears in the specified 
geographic region during the specified activities during the regulatory 
period would not significantly affect the quality of the human 
environment and, thus, preparation of an environmental impact statement 
for this incidental harassment authorization 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 Endangered Species Act (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 will 
complete intra-Service consultation under section 7 of the ESA on our 
proposed issuance of an IHA. These evaluations and findings will be 
made available on the FWS's website at: .

Government-to-Government Consultation

    It is our responsibility to communicate and work directly on a 
Government-to-Government basis with federally recognized 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 Natives. 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 Secretary's Orders 3206 (June 5, 
1997), 3225 (January 19, 2001), 3317 (December 1, 2011), 3342 (October 
21, 2016), and 3403 (November 15, 2021), as well as Director's Order 
227 (September 8, 2022);
    (5) Alaska Government-to-Government Policy (a departmental 
memorandum issued January 18, 2001); and
    (6) 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 15 walruses 
and 13 polar bears from Narwhal'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 rule 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.). OMB has 
previously approved the information collection requirements associated 
with IHAs and assigned OMB Control Number 1018-0194 (expires 8/31/
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 15 individuals from the Pacific walrus population and 13 
individuals from the SBS stock of polar bears. Authorized take will be 
limited to disruption of behavioral patterns that may be caused by the 
shallow hazard surveys, preliminary field surveys, exploratory drilling 
operations, and summer cleanup activities by Narwhal, LLC in West 
Harrison Bay, Alaska, from August 1, 2025, through July 31, 2026. We do 
not anticipate or authorize any take by Level A harassment, injury, or 
death to polar bears resulting from these activities.

A. General Conditions for the IHA for Narwhal

    1. Activities must be conducted in the manner described in the 
Revised Request dated April 2025 (received by the FWS April 3, 2025) 
for an IHA and in accordance with all applicable conditions and 
mitigation measures. The taking of walruses or 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 15 walruses or 13 polar bears from the SBS stock, a form of 
take other than Level B harassment, or take of one or more polar bears 
through methods not described in the IHA), Narwhal must take the 
following actions:
    i. Cease its activities immediately (or reduce activities to the 
minimum level necessary to maintain safety);
    ii. Report the details of the incident to the FWS within 48 hours; 
and
    iii. Suspend further activities until the FWS has reviewed the 
circumstances and determined whether additional mitigation measures are 
necessary to avoid further unauthorized taking.
    3. All operations managers, vehicle operators, and vessel operators 
must receive a copy of this IHA and maintain 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 proposed 
project as described in this document and in Narwhal's revised request. 
Changes to the proposed project without prior authorization may 
invalidate the IHA.
    5. Narwhal's revised request is approved and fully incorporated 
into this IHA unless exceptions are specifically noted herein. The 
revised request includes:
    i. Narwhal's Request for Incidental Harassment Authorization Under 
the

[[Page 34003]]

Marine Mammal Protection Act for Exploration Activities in West 
Harrison Bay, Alaska, dated November 2024 and revised April 2025 
(revised application received by the FWS April 3, 2025), which includes 
Narwhal's Polar Bear and Pacific Walrus Safety, Awareness, and 
Interaction Plan, and geospatial files.
    6. Operators will allow FWS personnel or the FWS's designated 
representative to visit project work sites to monitor for impacts to 
walruses or polar bears and subsistence uses of walruses or polar bears 
at any time throughout project activities so long as it is safe to do 
so. ``Operators'' are all personnel operating under Narwhal's 
authority, including all contractors and subcontractors.
    Narwhal must implement the following policies and procedures to 
avoid interactions and minimize to the greatest extent practicable any 
adverse impacts on walruses or polar bears, their habitat, and the 
availability of these marine mammals for subsistence uses.

B. General Avoidance Measures

    7. Narwhal must cooperate with the FWS and other designated 
Federal, State, and local agencies to monitor and mitigate the impacts 
of activities on walruses and polar bears.
    8. Trained and qualified personnel must be designated to monitor at 
all times for the presence of walruses and polar bears, initiate 
mitigation measures, and monitor, record, and report the effects of the 
activities on walruses and polar bears. Narwhal must provide all 
operators with polar bear awareness training prior to their 
participation in project activities.
    9. An FWS-approved polar bear and Pacific walrus safety, awareness, 
and interaction plan must be on file with the FWS's Marine Mammal 
Management office and available on site. The interaction plan must 
include:
    i. A description of the proposed activity (i.e., a summary of the 
plan of operations during the proposed activity);
    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 and walrus avoidance and encounter procedures; and
    vi. Polar bear and walrus observation and reporting procedures.
    Narwhal 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.
    10. Mitigation measures for aircraft. Narwhal must undertake the 
following activities to limit disturbance from aircraft activities:
    i. Operators of support aircraft shall, at all times, conduct their 
activities at the maximum distance practicable from concentrations of 
walruses or polar bears.
    ii. Fixed-wing aircraft operations within the IHA area must 
maintain a minimum altitude of 457 m (1,500 ft) above ground level when 
safe and operationally possible. Helicopter operations within the IHA 
area will maintain a minimum altitude of 457 m (1,500 ft) above ground 
level when safe and operationally possible to scan the work area before 
making landings.
    iii. 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 or walrus observed on ice or land measured in a 
straight line between the polar bear and the ground directly underneath 
the aircraft. Helicopters may not hover or circle above such areas or 
within 805 m (0.5 mi) of such areas. Unless 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 or walrus concentrations and should take precautions to avoid 
flying directly over or within 805 m (0.5 mi) of these areas.
    iv. Aircraft may not be operated in such a way as to separate 
individual polar bears or walruses from a group (i.e., two or more 
individuals).
    11. Mitigation measures for winter activities. Narwhal must 
undertake the following activities to limit disturbance around known 
polar bear dens:
    i. Narwhal must conduct two aerial infrared (AIR) surveys of all 
denning habitat located within 1.6 km (1 mi) of specified activities in 
an attempt to identify maternal polar bear dens. The first survey 
obtained must occur between December 1 and December 25, 2025, and the 
second survey obtained must occur between December 15, 2025, and 
January 10, 2026, with at least 24 hours occurring between the 
completion of the first survey and the beginning of the second survey. 
Surveys must not be conducted during daytime or times when weather 
conditions significantly hinder visibility (e.g., blowing snow, 
precipitation, or airborne moisture). A scientist with experience in 
real-time aerial infrared interpretation must be onboard during all 
flights. All AIR survey videos must be made available to the FWS within 
48 hours of survey completion.
    ii. All observed or suspected polar bear dens must be reported to 
the FWS prior to the initiation of activities.
    iii. If a suspected den site is located, Narwhal 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.
    iv. Operators must observe an 805 m (0.5 mi) operational exclusion 
zone around all putative polar bear dens during the denning season 
(November through April, or until the female and cubs leave the areas). 
Should a suspected den be discovered within 805 m (0.5 mi) of 
activities, work must cease, and the FWS contacted for guidance. The 
FWS will evaluate these instances on a case-by-case basis to determine 
the appropriate action. Potential actions may range from cessation or 
modification of work to conducting additional monitoring, and the 
holder of the authorization must comply with any additional measures 
specified.
    v. In determining the denning habitat that requires surveys, use 
the den habitat map developed by the USGS. A map of potential coastal 
polar bear denning habitat can be found at .
    vi. During the emergence season, February 15 to April 15, ATV 
travel along the coastal sea ice road must include a lead ATV equipped 
with a vehicle-mounted or hand-held thermal imaging device to scan for 
sows with cubs that are moving to the sea ice. Should sows and cubs of 
the year be seen, traffic must be halted to allow their unimpeded 
travel to the sea ice.
    12. Mitigation measures for in-water activities.
    i. Prior to and during airboat use, Narwhal must assess the access 
route for polar bears. While workers are transiting in the airboat, a 
designated occupant must be assigned to scan the surrounding area for 
marine mammals.
    ii. Vessels must always maintain the maximum distance possible from 
polar bears and walruses. Vessels should never approach within an 805-m 
(0.5-mi) radius of polar bears or walruses unless it is an emergency.
    iii. Vessels must take all practical measures (i.e., reduce speed, 
change course heading) to avoid approaching polar bears or walruses in 
the water,

[[Page 34004]]

avoid separating individual polar bears or walruses from a group, 
encircling polar bears or walruses, and impeding movement of polar 
bears or walruses.
    iv. When operationally feasible, vessels should engage in methods 
to limit vessel noise, such as reducing speed, performing regular 
vessel maintenance, using fewer vessels, and/or implementing vessel-
quieting technologies (e.g., propeller design, wake improvement 
devices, propulsion enhancement measures, hull treatment solutions).
    v. During seismic operations, Narwhal must designate a marine 
mammal observer aboard the source vessel that will monitor the area 
surrounding the seismic sound source. In the event that a walrus or 
polar bear is seen, Narwhal must report the encounter to the FWS 
following the requirements in C. Monitoring.

C. Monitoring

    13. Operators must provide on-site observers and implement the FWS-
approved polar bear and Pacific walrus safety, awareness, 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.
    14. All on-site observers shall complete an FWS-provided training 
course designed to familiarize individuals with monitoring and 
mitigation activities identified in the polar bear and Pacific walrus 
safety, awareness, and interaction plan.
    15. On-site observers must be present during all operations and 
must record all Pacific walrus and polar bear observations, identify 
and document potential harassment, and work with personnel to implement 
appropriate mitigation measures.
    16. Operators shall cooperate with the FWS and other designated 
Federal, State, and local agencies to monitor the impacts of project 
activities on walruses and polar bears. Where information is 
insufficient to evaluate the potential effects of activities on 
walruses and polar bears and the subsistence use of this species, 
Narwhal may be required to participate in joint monitoring efforts to 
address these information needs and ensure the least practicable impact 
to this resource.

D. Measures To Reduce Impacts to Subsistence Users

    Narwhal must conduct its activities in a manner that, to the 
greatest extent practicable, minimizes adverse impacts on the 
availability of walruses and polar bears for subsistence uses.
    18. Narwhal 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.
    19. If required, Narwhal will implement the FWS-approved POC.
    20. Prior to conducting the work, Narwhal will take the following 
steps to reduce potential effects on subsistence harvest of walruses 
and 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 
Nuiqsit of the proposed 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 walruses and 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

    Narwhal must report the results of monitoring to the FWS Marine 
Mammals Management office via email at [email protected].
    21. Activity progress reports. Narwhal must notify the FWS at least 
48 hours prior to the onset of activities;
    22. Walrus observation reports. Narwhal must report, within 48 
hours, all observations of walruses during any activity. Upon request, 
monitoring report data must be provided in a common electronic format 
(to be approved by the FWS). Information in the observation report must 
include, but is not limited to:
    i. Date, time, and location of each walrus sighting;
    ii. Number of walruses;
    iii. Sex and age (if known);
    iv. Observer name and contact information;
    v. Weather, visibility, sea state, and sea ice conditions at the 
time of observation;
    vi. Estimated range at closest approach;
    vii. Industry activity at time of sighting;
    viii. Behavior of animals sighted;
    ix. Description of the encounter;
    x. Duration of the encounter; and
    xi. Mitigation actions taken.
    23. Polar bear observation reports. Narwhal 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). Information in the observation report must include, but need not 
be limited to:
    i. Date and time of each observation;
    ii. Locations of the observer and polar bears (GPS coordinates if 
possible);
    iii. Number of polar bears;
    iv. Sex and age class--adult, subadult, cub (if known);
    v. Observer name and contact information;
    vi. Weather, visibility, and, if at sea, sea state and sea ice 
conditions at the time of observation;
    vii. Estimated closest distance of polar bears from personnel and 
facilities;
    viii. Type of work being conducted at time of sighting;
    ix. Possible attractants present;
    x. Polar bear behavior--initial behavior when first observed (e.g., 
walking, swimming, resting, etc.);
    xi. Potential reaction--behavior of polar bear potentially in 
response to presence or activity of personnel and equipment;
    xii. Description of the encounter;
    xiii. Duration of the encounter; and
    xiv. Mitigation actions taken.
    24. Human-polar bear interaction reports. Narwhal must report all 
human-polar bear interaction incidents immediately, and not later than 
48 hours after the incident. Human-polar bear interactions include:
    i. Any situation in which there is a possibility for unauthorized 
take. For instance, 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 all 
information specified for an observation report in condition 23 above, 
a complete detailed description of the incident, and any other actions 
taken.
    ii. 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.
    25. Final report. The results of monitoring and mitigation efforts

[[Page 34005]]

identified in the marine mammal 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 (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 walruses and 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 walruses and 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 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). 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. 2025-13488 Filed 7-17-25; 8:45 am]
BILLING CODE 4333-15-P