Marine Mammals; Proposed Incidental Harassment Authorization for the Southern Beaufort Sea Stock of Polar Bears During Well Remediation Activities, North Slope of Alaska; Draft Environmental Assessment, 2718-2735 [2025-00450]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 90, Number 7 (Monday, January 13, 2025)]
[Notices]
[Pages 2718-2735]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-00450]


-----------------------------------------------------------------------

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

[Docket No. FWS-R7-ES-2024-0147; FXES111607MRG01-256-FF07CAMM00]


Marine Mammals; Proposed Incidental Harassment Authorization for 
the Southern Beaufort Sea Stock of Polar Bears During Well Remediation 
Activities, North Slope of Alaska; Draft Environmental Assessment

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of receipt of application; proposed incidental 
harassment authorization; notice of availability of draft environmental 
assessment; request for comments.

-----------------------------------------------------------------------

SUMMARY: We, the U.S. Fish and Wildlife Service, in response to a 
request under the Marine Mammal Protection Act from the Bureau of Land 
Management, propose to authorize nonlethal incidental take by 
harassment of small numbers of Southern Beaufort Sea (SBS) polar bears 
(Ursus maritimus) for 1 year from the date of issuance of the 
incidental harassment authorization (IHA). The applicant requested this 
authorization for take by harassment that may result from activities 
associated with oil well plugging and reclamation, soil sampling, snow 
trail, pad, and airstrip construction, and summer cleanup activities in 
the North Slope Borough of Alaska between Wainwright and Oliktok. This 
proposed authorization, if finalized, will be for up to 12 takes of 
polar bears by Level B harassment. No Level A harassment or lethal take 
is requested, expected, or proposed to be authorized. We invite 
comments on the proposed IHA, the application package, draft 
environmental assessment, and related documents from the public and 
local, State, Tribal, and Federal agencies.

DATES: Comments must be received by February 12, 2025.

ADDRESSES: 
    Document availability: You may view documents at https://www.regulations.gov under Docket No. FWS-R7-ES-2024-0147. 
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: https://www.regulations.gov. Follow 
the instructions for submitting comments to Docket No. FWS-R7-ES-2024-
0147.
     U.S. mail: Public Comments Processing, Attn: Docket No. 
FWS-R7-ES-2024-0147, U.S. Fish and Wildlife Service, MS: PRB (JAO/3W), 
5275 Leesburg Pike, Falls Church, VA 22041-3803.
    We will post all comments at https://www.regulations.gov. 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: Charles Hamilton, 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

[[Page 2719]]

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, 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 June 17, 2024, the FWS received a request from the Department of 
the Interior's Bureau of Land Management (BLM) for authorization to 
take by nonlethal incidental harassment small numbers of Southern 
Beaufort Sea (SBS) polar bears (Ursus maritimus) during oil well 
plugging and reclamation; soil sampling; snow trail, pad, and airstrip 
construction; and summer cleanup activities in the North Slope Borough 
of Alaska between Wainwright and Oliktok for a period of 1 year from 
the date of issuance, and beginning during the winter of 2024-2025. 
Their request also included a proposed Polar Bear Awareness and 
Interaction Plan.
    The FWS requested further information on June 20, 2024, and July 
10, 2024. The BLM submitted clarifying information on July 10, 17, and 
23, 2024. The FWS received a revised application on August 26, 2024. 
The FWS deemed the revised request dated August 2024 (received August 
26, 2024; hereafter referred to as the ``Request'') adequate and 
complete on August 27, 2024.

Description of Specified Activities and Specified Geographic Region

    The specified activities described in the Request consist of oil 
well plugging and reclamation; soil sampling; snow trail, pad, and 
airstrip construction; and summer cleanup activities associated with 
two legacy well sites in the North Slope Borough of Alaska between 
Wainwright and Oliktok (figure 1; BLM 2024).
BILLING CODE 4333-15-P

[[Page 2720]]

[GRAPHIC] [TIFF OMITTED] TN13JA25.039

BILLING CODE 4333-15-C
    The BLM subsequently clarified that activities (e.g., resupply, 
backhaul of waste, demobilization of equipment) that could occur on 
pre-existing gravel roads to the east of the specified geographic 
region (i.e., between Oliktok and Prudhoe Bay) are not specified 
activities for which BLM requests incidental take authorization.

Fish Creek #1 Legacy Well Reclamation

    The Fish Creek #1 Legacy Well (Fish Creek well), located in wetland 
tundra approximately 14.5 kilometers (km) (9 miles [mi]) inland from 
the coast and approximately 39 km (24 mi) northwest of Nuiqsut, was 
drilled in 1949 by the U.S. Navy (figure 1). A concrete pad was built 
on pilings for drilling operations, and the cellar was concrete 
reinforced with steel matting. No reserve or flare pits are associated 
with this well. The well was drilled to a total depth of 2,139 meters 
(m) (7,020 feet [ft]), then plugged back to 777 m (2,550 ft) and 
sidetracked to a new total depth of 920 m (3,018 ft) (BLM 2024).
    In 2020 and 2021, the BLM began and completed soil sampling and 
debris removal at Fish Creek well. Sampling work showed areas around 
the wellhead with impacted soil and concrete, resulting in 3.1 cubic 
meters (m\3\) (4 cubic yards [yd\3\]) of material that were removed for 
disposal. The BLM's 2020-2021 cleanup efforts also generated 
approximately 29 m\3\ (38 yd\3\) of materials including recyclable 
scrap metal 8.4 m\3\ (11 yd\3\) and inert debris 21 m\3\ (27 yd\3\) for 
proper disposal. However, due to time constraints encountered during 
winter 2021 activities, the petroleum-contaminated soil identified 
during the sample efforts was not removed (estimated 3.8 m\3\ [5 
yd\3\]). Further in-depth descriptions of previous remediation actions 
at the Fish Creek well are provided within the BLM's application (BLM 
2024). The proposed project would permanently plug and close the Fish 
Creek well and remove all chemicals, fluids, drilling wastes, 
contaminated soil, and any remaining scattered surface debris found at 
the site. Specific methodology for well plugging and waste collection 
are described in the BLM's application (BLM 2024).

Cape Halkett #1 Legacy Well Reclamation

    The Cape Halkett #1 well (Cape Halkett well), located about 6.4 km 
(4 mi) from the coast and approximately 82 km (51 mi) northwest of 
Nuiqsut, was drilled by the U.S. Navy in 1975 (figure 1). The well site 
contains extensive wooden pilings that supported an elevated platform 
above the water to conduct drilling operations. An open casing extends 
0.6 m (2 ft) above ground level. It is located inside a steel framed 
and sheeted cellar that has been sheared on the east side and 
completely rusted at the base. The cellar contains minor amounts of 
metal debris inside and broken cement blocks outside. There is no 
reserve pit present. However, two low gravel-bermed areas were 
constructed, one around the fuel area and the other for discharge of 
drilling waste. The well was originally plugged in 1975 with four 
cement plugs set at 2,682 m (8,800 ft), 2,499 m (8,200 ft), and 2,387m 
(7,830 ft). The final plug was set with a mix of ArcticSet and Class G 
cement from 434 m (1,425 ft) to the surface of the well. Minor 
remediation efforts were undertaken in the late 1970s and early 1980; 
however, more is required. Sampling activities at the Cape Halkett well 
were performed by the U.S. Geological Survey (USGS) in 1989. Results of 
the sampling efforts showed elevated levels of total petroleum 
hydrocarbons (TPH), oil and grease concentrations, benzene, toluene, 
ethylbenzene, xylenes, barium, and chromium. Observations from the USGS 
and BLM site visits note a pile of drilling mud and a pile of cuttings 
near the well. The total volume of soil removal is not fully known; 
however, it

[[Page 2721]]

is not anticipated to be a substantial volume (BLM 2024).
    This project would verify and ensure permanent closure of the Cape 
Halkett well and remove all chemicals, fluids, drilling wastes, 
contaminated soil, and any remaining scattered surface debris found at 
the site. Any pilings still exposed above ground would be cut at or 
slightly below the ground surface of the excavated areas. Any excavated 
areas would be backfilled. Specific methodology for well plugging and 
waste collection are described in the BLM's application (BLM 2024).

Snow Trail, Pad, and Airstrip Construction

    There are no permanent roads available to directly access either of 
the two legacy wells included in this project; therefore, construction 
of temporary snow trails is required. Snow trail construction will 
begin in January or February 2025, starting with ``prepacking'' a 
minimum of 15 centimeters (6 inches) of base snow via all-terrain 
smooth-tracked vehicles approved for off-road tundra travel. Prepacking 
promotes lower tundra soil temperatures and accelerates freezing of 
soils prior to use, thereby helping to protect the tundra during snow 
trail and pad grooming, maintenance, and use. Snow will also be packed 
around stream crossings to protect stream banks and vegetation. Exact 
locations may vary up to 1.6 km (1 mi) on either side of the center 
lines of the snow trail routes depicted in figure 1 based on field 
conditions. This project will require the use of up to approximately 
790 km (491 mi) of 9-m (30-ft) wide snow trails; however, some of the 
trails utilized will include annually constructed public-use trail 
systems such as the North Slope Borough Community Winter Access Trail 
(CWAT) (BLM 2024). The majority of public snow trail usage, including 
all trails west of approximately 153[deg]W longitude, will occur only 
during demobilization after April 15 when polar bear denning season has 
ended. Only snow trails that have been surveyed for maternal dens via 
aerial infrared (AIR) (see Maternal Den Surveys) will be used during 
the denning season (November to April 15; figure 1). All snow trail 
usage will cease with the spring thaw.
    A 610-m (2,000-ft) long by 30-m (100-ft) wide snow airstrip will be 
constructed at both well sites to allow winter resupply via fixed-wing 
aircraft. No fuel will be stored at the airstrips. A 2.4-hectare (6-
acre, 152-m-by-152 m, 500-ft-by-500-ft) snow pad will be constructed at 
both well sites to support testing, cleanup, plugging, and other 
associated activities. No water will be used for snow trail, pad, or 
airstrip construction.

Mobilization, Resupply, and Demobilization

    Large equipment, including mobile camp trailers, drill rigs, and 
other support equipment and supplies, will be moved west to the Fish 
Creek and Cape Halkett well sites from routes originating at either the 
2P gravel pad and/or existing pads at Oliktok (figure 1). The specific 
route will be determined, in part, by environmental conditions. 
However, to be conservative, our analyses assume all routes are used. 
Equipment will be hauled along snow trails by appropriate sized 
tractors or other similar equipment. In January or February 2025, four 
to six trips will be required to haul camp trailers, vehicles, and 
drill rig equipment to the well sites, followed by four to six trips to 
return equipment during demobilization in April 2025. During 
operations, up to 30 additional round trips will be required for 
resupply and/or backhaul waste at both well sites. Furthermore, up to 
25 winter resupply flights via fixed-wing aircraft will be required at 
both well sites (up to 50 total flights).
    Following final well plugging, cleanup, inspections, and soil 
sampling, all equipment would be demobilized Wainwright, Utqiagvik, or 
Atqasuk along routes shown in figure 1. The drill rig and wastes 
generated from the well plugging and closure would be transported along 
routes to 2P or Oliktok before final transportation for appropriate 
disposal. The majority of snow trail and camp cleanup, such as trash 
removal and stick-picking, will occur during demobilization, but final 
inspections will occur during the summer via helicopter (see Summer 
Cleanup and Inspections). Full scope of waste material disposal 
procedures is available in the BLM's application (BLM 2024).

Camp Setup

    Mobile camps will be required to provide crew lodging during well 
site activities. The camp set up at Fish Creek will consist of 20-25 
trailers to provide housing, restrooms, kitchen, office space, shop 
spaces, and other required facilities for approximately 25 personnel. 
At Cape Halkett, 7-10 trailers will be required to provide the same 
amenities to 15 personnel. Camps will be established within 1 mile of 
the well site based on initial field scouting and environmental 
conditions. Generation of potable water from snow and disposal of grey 
water will follow Alaska Department of Environmental Conservation 
guidance and regulation. Project-generated waste such as household 
trash, rags, and other used disposable materials will be stored on 
location in approved containers to prevent wildlife access until being 
incinerated using appropriate equipment or disposed of at a permitted 
landfill.

Summer Cleanup and Inspections

    The majority of snow trail and camp cleanup, such as trash removal 
and stick-picking, will occur during demobilization in spring 2025 
(April-May). However, a helicopter will be used for approximately 8-10 
days in July and/or August 2025 to inspect and remove any debris left 
on the snow trails, pads, airstrip, and well sites. The helicopter will 
fly at low elevation (under 50 ft) to conduct inspections. In addition, 
the helicopter will land at the well sites for soil sampling (with hand 
tools) and final inspections, and to remove surface debris that may 
have been missed during winter operations. Approximately 50 helicopter 
landings would be expected during summer cleanup, inspections, and 
sampling activities.

Maternal Den Surveys

    The BLM will conduct two AIR maternal polar bear den surveys prior 
to beginning operations to identify any active dens in project areas 
that will be utilized during the denning period. This compromises the 
north-south snow trail located approximately along 153[deg]W longitude 
and all project components to the east of this trail, including the 
well sites, lakes, and other snow trails (figure 1). The surveyors will 
use AIR cameras on fixed-wing aircraft, with flights flown between 245-
457 m (800-1,500 ft) above ground level at a speed of <185 kilometers 
per hour (<115 miles per hour). 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, 2024, and the second survey will be 
conducted between December 15, 2024, and January 10, 2025, with a 
minimum of 24 hours between surveys. Sections of the project impact 
area that will not be used until after denning season (after April 15) 
will not be surveyed.

Description of Marine Mammals in the Specified Geographic Region

    Polar bears are the only species of marine mammal managed by the 
FWS likely to be found within the specified

[[Page 2722]]

geographic region. Information on range, stocks, biology, and climate 
change impacts on polar bears can be found in appendix A of the 
supplemental information (available as described above in ADDRESSES).

Potential Impacts of the Specified Activities on Marine Mammals

Surface-Level Impacts on Polar Bears

    Disturbance impacts on polar bears will be influenced by the type, 
duration, intensity, timing, and location of the source of disturbance. 
Disturbance from the specified activities would originate primarily 
from aircraft overflights (helicopter and fixed wing), tundra travel, 
well site plugging and reclamation, well site soil sampling, 
mobilization and demobilization, 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 Gutierrez 2003). However, individual response to noise 
disturbance can be influenced by previous interactions, sex, age, and 
maternal status (Anderson and Aars 2008; Dyck and Baydack 2004). Noise 
and odors could also attract polar bears to work areas. Attracting 
polar bears to these locations could result in human-polar bear 
interactions, unintentional harassment, intentional hazing, or possible 
lethal take in defense of human life. This proposed IHA, if finalized, 
would authorize only the nonlethal, incidental, unintentional take of 
polar bears that may result from the specified activities and would 
require mitigation measures to manage attractants in work areas and 
reduce the risk of human-polar bear interactions.

Human-Polar Bear Interactions

    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. 2016; 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 humans and polar 
bears when interactions occur. Polar bear interaction plans detail the 
policies and procedures that will be implemented by the BLM 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. Efficient 
management of attractants (e.g., human food, garbage) can prevent polar 
bears from associating humans with food, which mitigates the risk of 
human-polar bear interactions (Atwood and Wilder 2021). Information 
gained from monitoring polar bears near industrial infrastructure 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, closed-
circuit television, video cameras, thermal cameras, radar devices, and 
motion-detection systems. It is possible that human-polar bear 
interactions may occur during the specified activities, and mitigation 
measures, as described in the applicant's Polar Bear Awareness and 
Interaction Plan, will be implemented by the BLM to minimize the risk 
of human-polar bear interactions during the specified activities.
    From mid-July to mid-November, SBS stock 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 industrial 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 kilohertz (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 (called permanent 
threshold shift, or PTS). Species-specific TTS and PTS thresholds have 
not been established for polar bears at this time, but TTS and PTS 
thresholds have been established for the general group ``other marine 
carnivores,'' which includes polar bears (Southall et al. 2019). 
Through a series of systematic modeling procedures and extrapolations, 
Southall et al. (2019) generated modified noise exposure thresholds for 
both in-air and underwater sound (table 1).

 Table 1--Temporary Threshold Shift (TTS) and Permanent Threshold Shift (PTS) Thresholds 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
----------------------------------------------------------------------------------------------------------------
Air.........................             157          146          170             177          161          176

[[Page 2723]]

 
Water.......................             199          188          226             219          203          232
----------------------------------------------------------------------------------------------------------------
Note: Values are weighted for other marine carnivores' hearing thresholds and given in cumulative sound exposure
  level (SELCUM dB re 20[micro]Pa in air and SELCUM dB re 1 [micro]Pa in water) for impulsive and nonimpulsive
  sounds, and unweighted peak sound pressure level in air (dB re 20[micro]Pa) and water (dB 1[micro]Pa)
  (impulsive sounds only).

    During a Federal Aviation Administration test, 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 ceasing to rest, walking, or running, and, 
therefore, has the potential to be energetically costly. Polar bears 
observed during intentional aircraft overflights conducted to study 
impacts of aircraft on polar bear responses, with an average flight 
altitude of 143 m (469 ft), exhibited biologically meaningful 
behavioral responses during 66.6 percent of aircraft overflights. These 
behavioral responses were significantly correlated with the aircraft's 
altitude, the 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 when exposed to low-
flying aircraft, ranging from increased head movement and observation 
of the disturbance to the initiation of rapid movement and/or den 
abandonment (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.

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 during planned surveys for tracking marked polar 
bears and detecting polar bear dens. However, these sites are only a 
small percentage of the total active polar bear dens for the SBS stock 
in any given year. Each year, many entities conducting operations on 
the North Slope coordinate with the FWS to conduct surveys to determine 
the location of any polar bear dens that may be located in close 
proximity to any of the operator's planned activities for that denning 
season. Under past IHAs and ITRs (Incidental Take Regulations), 
operators have been required to avoid known polar bear dens by 1.6 km 
(1 mi). However, an unknown polar bear den may be encountered during 
the BLM's activities. In instances when a previously unknown den was 
discovered near human activity, the FWS has implemented mitigation 
measures such as a 1.6-km (1-mi) 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. (2022) and are also located in the 2021-2026 Beaufort 
Sea 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 the supplemental information to 
this document (available as described in ADDRESSES).

Estimated Take

Definitions of Incidental Take Under the Marine Mammal Protection Act

    Below we provide definitions of three types of take of polar bears. 
The FWS does not anticipate and is not authorizing either Level A 
harassment or lethal take as a part of this proposed IHA; however, the 
definitions of these take types are provided for context and 
background.

Lethal Take

    Human activity may result in biologically significant impacts to 
polar bears. In the most serious interactions (e.g., vehicle collision, 
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 either to abandon her den prematurely with 
cubs or abandon her cubs in the den before the cubs can survive on 
their

[[Page 2724]]

own. Either scenario may result in the incidental lethal take of the 
cubs.

Level A Harassment

    Human activity may result in the injury of 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.

Level B Harassment

    Level B harassment for nonmilitary readiness activities means 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;
     Abandoning or avoiding preferred movement corridors such 
as ice floes, leads, polynyas, a segment of coastline, or barrier 
islands;
     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 cubs struggling to 
keep up;
     Temporary, short-term cessation of nursing or resting 
(cubs);
     Ceasing to rest repeatedly or for a prolonged period 
(adults);
     Loss of hunting opportunity due to disturbance of prey; or
     Any interruption in normal denning behavior that does not 
cause injury, den abandonment, or early departure of the female with 
cubs from the den site.
    This list is not meant to encompass all possible behaviors; other 
behavioral responses may be indicative of take by Level B harassment. 
Relatively minor changes in behavior such as the animal raising its 
head or temporarily changing its direction of travel are not likely to 
disrupt biologically important behavioral patterns, and the FWS does 
not view such minor changes in behavior as indicative of a take by 
Level B harassment. It is also important to note that eliciting 
behavioral responses that equate to take by Level B harassment 
repeatedly may result in Level A harassment.

Surface Interactions

    We analyzed take by Level B harassment for polar bears that may 
potentially be encountered and impacted during the BLM's oil well 
plugging and reclamation, soil sampling, snow trail, pad, and airstrip 
construction, and summer cleanup activities within the specified 
geographic region.

Impact Area

    To assess the area of potential impact from the project activities, 
we calculate the area affected by project activities where harassment 
is possible. We refer to this area as an impact area. Behavioral 
response rates of polar bears to disturbances are highly variable, and 
data to support the relationship between distance to polar bears and 
disturbance are limited. Dyck and Baydack (2004) found sex-based 
differences in the frequencies of vigilance bouts, which involves an 
animal raising its head to visually scan its surroundings, by polar 
bears in the presence of vehicles on the tundra. However, in their 
summary of polar bear behavioral response to ice-breaking vessels in 
the Chukchi Sea, Smultea et al. (2016) found no difference between 
reactions of males, females with cubs, or females without cubs. During 
the FWS's coastal aerial surveys, 99 percent of polar bears that 
responded in a way that indicated possible Level B harassment (polar 
bears that were running when detected or began to run or swim in 
response to the aircraft) did so within 1.6 km (1 mi), as measured from 
the ninetieth percentile horizontal detection distance from the flight 
line. Similarly, Andersen and Aars (2008) found that female polar bears 
with cubs (the most conservative group observed) began to walk or run 
away from approaching snowmobiles at a mean distance of 1,534 m (0.95 
mi). Thus, while future research into the reaction of polar bears to 
anthropogenic disturbance may indicate a different zone of potential 
impact is appropriate, the current literature suggests that the 1.6-km 
(1.0-mi) impact area will encompass most surface 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 the specified project activity information. Some 
portion of SBS bears may occur within the Chukchi Sea at a given time. 
However, the ITR rates do not explicitly account for this possibility, 
and the project area for this proposed IHA occurs only within the 
geographical boundary of the SBS subpopulation. Therefore, our analyses 
account only for SBS bears located within the SBS subpopulation 
boundary. Distribution patterns of polar bears along the coast of the 
SBS were estimated in Wilson et al. (2017) by dividing the North Slope 
Coastline into 10 equally sized grids and applying a Bayesian 
hierarchical model based on 14 years of aerial surveys in late summer 
and early fall. Wilson et al. (2017) estimated 140 polar bears per week 
along the coastline (a measurement that included barrier islands); 
however, not with uniform distributions. The study found that 
disproportionately high densities of bears occur in grids 6 and 9, 
which contain known large congregating areas such as Kaktovik and Cross 
Island; thus, the study has required polar bear density correction of 
factors in previously issued incidental take authorizations (ITAs). The 
vast majority of the coastline within the project area in this proposed 
IHA falls within grids 1-4 (although a small portion of the project 
area is located outside of Wilson et al.'s (2017) study area near the 
City of Wainwright). The Wilson et al. (2017) values for grids 1-4 are 
similar to those in the North Slope area where the 2021-2026 Beaufort 
Sea ITR (86 FR 42982, August 5, 2021) encounter rates were developed; 
therefore, we believe those values are applicable to the project area 
in this proposed IHA and do not require any correction factor for polar 
bear densities in our analyses.

 Table 2--Definitions of Variables Used in Harassment Estimates of Polar
             Bears on the Coast of the North Slope of Alaska
------------------------------------------------------------------------
                Variable                            Definition
------------------------------------------------------------------------
B......................................  Bears encountered in an impact
                                          area for the entire season.
a......................................  Coastal exposure area.

[[Page 2725]]

 
ai.....................................  Inland exposure area.
r......................................  Occupancy rate.
e......................................  Coastal open-water season bear-
                                          encounter rate in bears/
                                          season.
e......................................  Coastal ice season bear-
                                          encounter rate in bears/
                                          season.
e......................................  Inland open-water season bear-
                                          encounter rate in bears/
                                          season.
e......................................  Inland ice season bear-
                                          encounter rate in bears/
                                          season.
t......................................  Ice season harassment rate.
t......................................  Open-water season harassment
                                          rate.
B......................................  Number of estimated Level B
                                          harassment events.
------------------------------------------------------------------------

    Table 2 provides the definition for each variable used in the 
formulas to calculate the number of potential harassment events. The 
variables defined in table 2 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 km per season. As a part of their Request, the 
BLM provided the FWS with digital geospatial files that included the 
maximum expected human occupancy (i.e., rate of occupancy 
[ro] for each individual structure (e.g., snow trails, snow 
pads) of their specified activities for each season of the IHA period. 
Using the buffer tool in ArcGIS, we created a spatial file of a 3.2-km 
(2-mi) buffer around all snow trails (3.2 km on either side of the 
proposed snow trail center line, i.e., 6.4 km [4 mi] total diameter) to 
account for up to 1.6-km (1-mi) deviations from the proposed center 
line of the routes, and around both well sites to account for the 
presently undetermined camp locations (within 1.6 km [1 mi] of well 
head). Additionally, we placed a 1.6-km (1-mi) buffer around all lakes 
that may be potentially utilized during operations. We binned the 
structures according to their seasonal occupancy rates by rounding them 
up into tenths (10 percent, 20 percent, etc.). We determined the impact 
area of each bin by first calculating the area within the buffers of 
100-percent occupancy locations. We then removed the area of the 100-
percent occupancy buffers from the project impact area and calculated 
the area within the 90-percent occupancy buffers. This iterative 
process continued until we calculated the area within all buffers. The 
areas of impact were then clipped by coastal and inland zone geospatial 
files to determine the coastal areas of impact (ac) and 
inland areas of impact (ai) for each occupancy bin. This 
process was repeated for both seasons (ice season and open-water [ice-
free] season).
    Impact areas were multiplied by the appropriate encounter rate to 
obtain the number of polar bears expected to be encountered in the 
impact area per season (Bes). Equation 1 provides an example 
of the calculation of polar bears encountered in the ice season for an 
impact area 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, 
mitigation measures, such as minimum flight altitudes over polar bears 
and restrictions on sudden changes to aircraft movements and direction, 
will be required if this authorization is finalized. 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 38 m (100 ft). Researchers recorded 
behavioral changes during these approaches and evaluated if and when 
Level B harassment occurred. Covariates examined were polar bear 
location (``barrier island'' or ``mainland''), initial behavior 
(``active'' or ``inactive''), group size, whether the polar bear 
belonged to a family group, and the number of previous overflights 
(i.e., how many times the group was re-approached to elicit a 
behavioral change). A Bayesian imputation approach accounted for polar 
bears that exhibited a behavioral change consistent with harassment on 
their first approach, thus lacking an identified altitude at which no 
harassment occurred due to a lack of a ``non-harassment'' observation. 
Their final model included location, activity level, and the number of 
previous overflights as predictors of the altitude at which a polar 
bear was harassed. For our aircraft impacts analysis, we used 
harassment rates estimated for active polar bears observed on barrier 
islands, as they had the highest rates of harassment. We further 
assumed that no previous overflights were conducted.
    We provide harassment rates for the 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 3).

[[Page 2726]]



 Table 3--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 rate 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 (https://www.flightaware.com/), 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 per hour (80 mi per hour), 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 clearly or were 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 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.

          Table 4--Seasonal Polar Bear Encounter Rates by Zone
------------------------------------------------------------------------
 
------------------------------------------------------------------------
                  Coastal Zone Seasonal Encounter Rate
------------------------------------------------------------------------
Ice Season (July 19-November 11)................  0.05 bears/km\2\.
Open-water Season (November 12-July 18).........  1.48 bears/km\2\.
------------------------------------------------------------------------
                   Inland Zone Seasonal Encounter Rate
------------------------------------------------------------------------
Ice Season (July 19-November 11)................  0.004 bears/km\2\.
Open-water Season (November 12-July 18).........  0.005 bears/km\2\.
------------------------------------------------------------------------
Note: This table is adapted from the 2021-2026 Beaufort Sea ITR (86 FR
  42982, August 5, 2021).

    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 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 5 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.

[[Page 2727]]



                              Table 5--Summary of Aircraft Operations by Season and Activity During the Proposed IHA Period
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                 Ice season (fixed-wing aircraft only)                         Open-water season (helicopter only)
                              --------------------------------------------------------------------------------------------------------------------------
                                                                                                                     Site Inspection--
           Activity              Winter support--     Winter support--   Site inspection--     Site inspection--      Cape Halkett to      Snow trail
                                   Cape Halkett          Fish Creek      Deadhorse to Cape     Deadhorse to Fish        Fish Creek       inspection and
                                                                              Halkett                Creek                                   cleanup
--------------------------------------------------------------------------------------------------------------------------------------------------------
Altitude *...................  High...............  High...............  High.............  High..................  High..............  Low
Total Flights................  25.................  25.................  6................  5.....................  2.................  12
Proportion of Season.........  0.0026.............  0.0021.............  0.0020...........  0.0012................  0.00017...........  0.01887
Proportion of Flight in        0.60...............  0..................  .60..............  0.....................  0.51..............  0.26
 Coastal Zone.
Proportion of Flight in        0.40...............  1..................  .40..............  1.....................  0.49..............  0.74
 Inland Zone.
Total Encounter Rate (bears/   0.0316.............  0.004..............  0.89.............  0.005.................  0.7573............  0.3885
 km\2\/season) **.
Harassment Rate..............  0.001..............  0.001..............  0.05.............  0.05..................  0.05..............  0.99
Flight Time Harassment.......  6.570 x 10-\07\....  6.744 x 10-\08\....  0.000643.........  2.440 x 10-\06\.......  5.295 x 10-\05\...  0.05909
Total Takeoffs and Landings..  50.................  50.................  12...............  10....................  4.................  24
Landing Time/Season..........  0.001389...........  0.001389...........  0.000725.........  0.000604..............  0.000242..........  0.001449
Landing Time Harassment......  0.0016283..........  0.0016283..........  0.025146.........  0.020955..............  0.008382..........  0.0502921
Takeoff Time/Season..........  0.001389...........  0.001389...........  0.000725.........  0.000604..............  0.000241..........  0.001449
Takeoff Time Harassment......  0.001094...........  0.001094...........  0.016893.........  0.014078..............  0.00563...........  0.03379
Number Level B Harassment of   0.002723...........  0.002723...........  0.042683.........  0.035035..............  0.014066..........  0.143164
 Activity.
--------------------------------------------------------------------------------------------------------------------------------------------------------
    Total number of level B harassment events across all aircraft activities..............  0.240.................
--------------------------------------------------------------------------------------------------------------------------------------------------------
* 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.

Estimated Harassment From Aircraft Activities

    Using the approaches described above, we estimated the total number 
of polar bears expected to be harassed by the aircraft activities 
during the proposed IHA period as a total of one bear (table 5).

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 2023-2024 BLM IHA (88 FR 88943, December 26, 2023).
    Additionally, on March 19, 2024, regulations promulgated in the 
2021-2026 Beaufort Sea ITR (86 FR 42982, August 5, 2021) were 
challenged in Federal Court and the Ninth Circuit Court of Appeal 
issued a remand to FWS to conduct certain additional analysis. As a 
result of the Court's remand and ongoing scientific advancements, the 
FWS reexamined the denning analysis and incorporated newly available 
data since 2021 into the denning analysis model, allowing the continued 
inclusion of best available scientific information. Updates 
incorporated into the model adjust the impact area that can result in 
den disturbance, the probabilities of disturbance, and how FWS reports 
probabilities of different levels of take, i.e., Level B harassment, 
Level A harassment, and lethal take. Alterations to the denning model 
are described in greater detail below.

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 2023-2024 BLM IHA (88 FR 88943, 
December 26, 2023).

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, 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), 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 denning period were 
considerably closer than those observed during other denning periods. 
Specifically, of the 15 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 meters. This 
single den record also had imprecise information on the distance to 
human activity, so activity was assumed to occur within 1,610 m 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. 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

[[Page 2728]]

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. As a result, dens that were simulated to be 
within 805 m of human activity could be disturbed during all denning 
periods, while dens between 806 and 1610 m way from human activity 
could only be disturbed during the den establishment, late denning, and 
post-emergence periods.

AIR Surveys

    We assumed that all remediation and transit areas that will be 
utilized during denning season would have two AIR surveys flown prior 
to beginning any operations (figure 1). The first survey would occur 
between December 1 and December 25, 2024, and the second survey between 
December 15, 2024, and January 10, 2025, 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 2023-2024 BLM IHA (88 FR 
88943, December 26, 2023).

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. 2022a), 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 6). 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 and 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 6) 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 6). 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 6). 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 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 until 
approximately 100 days post emergence, derived from the analysis of 
empirical data on the dates of emergence from the den and departure 
from the den site (Anderson 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:

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 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 
(Anderson 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 6 shows the probability of an exposure 
resulting in the types of harassment of denning polar bears.

[[Page 2729]]



  Table 6--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     Level B      Level B      Level A       Lethal
                 Denning period                   or cub(s))     (sow)       (cub(s))     (cub(s))     (cub(s))
----------------------------------------------------------------------------------------------------------------
Den Establishment..............................        0.750        0.250        0.000        0.000        0.000
Early Denning..................................        0.860        0.140        0.000        0.000        0.130
Late Denning...................................        0.510        0.490        0.000        0.490        0.000
Post Emergence--Previously Undisturbed Den.....        0.000        1.000        0.200        0.800        0.000
Post Emergence--Previously Disturbed Den.......        0.000        1.000        0.474        0.526        0.000
----------------------------------------------------------------------------------------------------------------
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. Probabilities were calculated from the analysis of 60 case studies of polar bear responses
  to human activity. 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

    Our analysis estimates a mean of 1.36 (median = 1; 95 percent CI: 
0-4) land-based dens in the project area will potentially be exposed to 
disturbance from the specified activities during the 1-year period of 
the proposed IHA. Our den simulation analysis predicts this degree of 
potential exposure will have a zero (0) percent chance of incurring 
Level B harassment. Furthermore, our analysis predicts a zero (0) 
percent probability of the BLM's specified activities resulting in 
either Level A harassment or lethal take during the 1-year period of 
the proposed IHA.

Critical Assumptions

    To conduct this analysis and estimate the potential amount of Level 
B harassment, Level A harassment, and lethal take, we made several 
critical assumptions.
    Level B harassment is equated herein with behavioral responses that 
indicate harassment or disturbance, but not to the extent that cause 
the animal to 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. Not enough information on composition of 
the SBS polar bear stock in the specified project area is available 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 in response to the specified 
activities. Our assessment assumes animals remain stationary (i.e., 
density does not change). Not enough information is available about the 
movement of polar bears in response to specific disturbances to refine 
this assumption.
    The SBS polar bears create maternal dens on the sea ice as well as 
on land. The den simulation used in our analysis does not simulate dens 
on the sea ice. However, the specified activities will be conducted 
entirely on land and only a small percentage of the activities will 
occur within 1.6 km (1 mi) of the coastline. Therefore, the impact of 
the activities will be primarily limited to land-based dens within 1.6 
km (1 mi) of the project impact areas used during denning season. 
Additionally, this impact area will be surveyed during AIR surveys to 
mitigate impacts on denning polar bears.
    The specific combination of snow trail segments depicted in figure 
1 that will be used for mobilization, resupply, and backhauling is not 
currently known. For the purposes of the above analyses and estimates 
of take by Level B and Level A harassment, and the risks of lethal 
take, we assumed that all routes within the AIR surveyed section 
(figure 1) of the project might potentially be used at some point 
during the denning season. This assumption results in a very 
conservative estimate of take for the 1-year IHA period that accounts 
for all possible operational scenarios.

Sum of Harassment From All Sources

    Our analyses quantified the total number of Level B harassment, 
Level A harassment, and lethal take likely to result from the BLM's 
specified activities. We evaluated three potential sources of 
harassment/take, including surface interactions, aircraft overflights, 
and den disturbance of sows and/or cubs in our analyses. A summary of 
total estimated take via Level B harassment during the project by 
source is provided in table 7. We do not anticipate take by Level A 
harassment or lethal take to occur.

 Table 7--Total Estimated Takes by Harassment of Polar Bears, by Source
------------------------------------------------------------------------
                                                           Number of
            Source and type of harassment                  estimated
                                                          harassments
------------------------------------------------------------------------
Bears on the surface--summer--Level B harassment.....                  1
Bears on the surface--winter--Level B harassment.....                 10
Aircraft activities--summer and winter--Level B                        1
 harassment..........................................
                                                      ------------------
    Total............................................                 12
------------------------------------------------------------------------


[[Page 2730]]

Determinations and Findings

    In making these draft findings, we considered the best available 
scientific information, including: the biological and behavioral 
characteristics of polar bears, the most recent information on polar 
bear distribution and abundance within the area of the specified 
activities, the current and expected future status of the stock 
(including existing and foreseeable human and natural stressors), the 
potential sources of disturbance caused by the project, and the 
potential responses of polar bears to this disturbance. In addition, we 
reviewed applicant-provided materials, information in our files and 
datasets, and published reference materials, and consulted with species 
experts.

Small Numbers

    For our small numbers determination, we consider whether the 
estimated number of polar bears to be subjected to incidental take is 
small relative to the population size of the species or stock.
    1. We estimate that BLM's proposed specified activities in the 
specified geographic region will cause the take of no more than 12 
polar bears by Level B harassment during the 1-year period of this 
proposed IHA (table 7). Take of 12 animals is 1.32 percent of the best 
available estimate of the current SBS stock size of 907 animals 
(Bromaghin et al. 2015; Atwood et al. 2020) ((12/907) x 100 [ap] 1.32 
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 extremely small relative to the range of the SBS 
stock of polar bears. Polar bears from the SBS stock occur well beyond 
the boundaries of the proposed IHA region. As such, the IHA boundaries 
represent only a minute subset of the potential area in which the polar 
bear may occur. Thus, the FWS concludes that a small portion of the SBS 
polar bear populations may be present in the specified geographic 
region during the time of the specified activities.

Small Numbers Conclusion

    We propose a finding that take of up to 12 SBS polar bears 
represents a small number of the SBS stock of polar bears.

Negligible Impact

    For our negligible impacts determination, we consider the 
following:
    1. The distribution and habitat use patterns of polar bears 
indicate that relatively few polar bears will occur in the specified 
areas of activity at any time and, therefore, few polar bears are 
likely to be affected.
    2. The documented impacts of previous activities, including the 
2023-2024 BLM IHA (88 FR 88943), similar to the specified activities on 
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 ITAs, suggests that the types of activities 
analyzed for this proposed IHA will have minimal effects on 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 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 polar bear's health, reproduction, or survival. 
The limited extent of anticipated impacts on polar bears is unlikely to 
adversely affect annual rates of polar bear survival or recruitment. 
Thus, we do not expect any long-term negative consequences to either 
individual- or population-level fitness.
    3. The IHA, if finalized, would require implementation of 
monitoring requirements and mitigation measures designed to reduce the 
potential impacts of their operations on polar bears. Den detection 
surveys for polar bears and 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 polar bears and, therefore, limit potential disturbance of these 
animals.
    4. The FWS does not anticipate any lethal take that would remove 
individual polar bears from the population or prevent their successful 
reproduction. This proposed IHA does not authorize any take by Level A 
harassment or injury that will likely result in the death of a polar 
bear.
    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 are the mortality of 
cubs that could result from disturbances during certain periods of the 
denning season. The FWS estimated that the probability of greater 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 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

[[Page 2731]]

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 well-plugging and reclamation activities on 
polar bears, including impacts from surface interactions, aircraft 
overflights, and den disturbance. 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 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 polar 
bear habitat and behavior. The FWS is currently involved in research to 
understand how climate change may affect 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 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 
SBS polar bears. We do not propose to authorize lethal take or any take 
by Level A harassment that we believe could result in long-term 
individual or population level fitness consequences.

Impact on Subsistence Use

    Based on past community consultations, locations of hunting areas, 
no anticipated overlap of hunting areas and project activities, and the 
best scientific information available, including monitoring data from 
similar activities, we propose a finding that take caused by the oil 
well plugging and reclamation; soil sampling; snow trail, pad, and 
airstrip construction; and summer cleanup activities in the project 
area will not have an unmitigable adverse impact on the availability of 
polar bears for taking for subsistence uses during the proposed 
timeframe.
    While polar bears represent a small portion, in terms of the number 
of animals, of the total subsistence harvest for the Utqiagvik, 
Nuiqsut, Wainwright and Atqasuk communities, their harvest is important 
to Alaska Natives. The BLM will be required to notify the cities of 
Wainwright and Utqiagvik and the Native villages of Atqasuk and Nuiqsut 
of the planned activities and document any discussions of potential 
conflict. The BLM must make reasonable efforts to ensure that 
activities do not interfere with subsistence hunting and that adverse 
effects on the availability of polar bears are minimized. Should such a 
concern be voiced, development of plans of cooperation (POC), which 
must identify measures to minimize any adverse effects, will be 
required. 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 the BLM will work with the affected Alaska Native communities and 
what actions will be taken to avoid interference with subsistence 
hunting of polar bears, as warranted.
    The FWS has not received any reports and is not aware of 
information that indicates that polar bears are being or will be 
deterred from hunting areas or impacted in any way that diminishes 
their availability for subsistence use by oil well plugging and 
reclamation; soil sampling; snow trail, pad, and airstrip construction; 
and summer cleanup. If there is evidence that these activities are 
affecting the availability of polar bears for take for subsistence 
uses, we will reevaluate our findings regarding permissible limits of 
take and the measures required to ensure continued subsistence hunting 
opportunities.

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 the BLM's activities in the specified geographic region. We 
propose a finding that the mitigation measures included within the 
BLM's Request will ensure least practicable adverse impacts on polar 
bears (BLM 2024).
    Polar bear den surveys at the beginning of the winter season, the 
resulting 1.6-km (1-mi) operational exclusion zone around any known 
polar bear dens, and restrictions on the timing and types of activities 
in the vicinity of dens will ensure that impacts to denning female 
polar bears and their cubs are minimized during this critical period. 
Minimum flight elevations over polar bear areas and flight restrictions 
around observed polar bears and known polar bear dens will reduce the 
potential for aircraft disturbing polar bears. Finally, the BLM 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 storing 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 the BLM'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 the BLM's Request (BLM 2024) and 
incorporated into this authorization will minimize impacts from the 
specified oil well plugging and reclamation, soil sampling, snow trail, 
pad, and airstrip construction, and summer cleanup activities to the 
extent practicable.
    Several mitigation measures were considered but determined to be 
not practicable. These measures are listed below:
     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 practicable 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;
     One-mile buffer around all known polar bear denning 
habitat--One-mile (1.6-km) buffer around all known polar bear denning 
habitat is not practicable as much of the BLM's proposed project area 
occurs within 1.6 km (1 mi) of denning habitat; thus, to exclude all 
areas within 1.6 km of denning habitat would preclude the planned 
activities from occurring;
     Prohibition of driving over high relief areas, 
embankments, or stream and river crossings--While the denning habitat, 
such as high relief areas, embankments, and streams or river banks, 
must be considered during tundra travel, complete prohibition is not 
practicable. High relief areas, embankments, streams, and rivers occur 
throughout the project area. To completely avoid these types of areas 
would likely cause personnel to drive further away from established 
operational areas and unnecessarily create additional safety concerns. 
Furthermore, other mitigation measures to minimize impact to denning 
habitats are included and will minimize the risk imposed by driving 
over high relief areas, embankments, or stream and river crossings;
     Use of a broader definition of ``denning habitat'' for 
operational offsets--There is no available data to

[[Page 2732]]

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;
     Require all activities to cease if a polar bear is injured 
or killed until an investigation is completed--The FWS has incorporated 
reporting requirements into this proposed authorization for all polar 
bear interactions. While it may aid in any subsequent investigation, 
ceasing all activities may not be practicable or safe and, thus, will 
not be mandated;
     Require use of den detection dogs--It is not practicable 
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 versus ground-based FLIR 
(handheld or vehicle-mounted FLIR) due to impacts of blowing snow on 
detection. The BLM has incorporated into their mitigation measures the 
use of handheld or vehicle-mounted FLIR when transiting rivers 
occurring in suitable denning habitat, but it is not practicable to use 
the equipment during all transit;
     Construct safety gates, fences, and enclosures to prevent 
polar bears from accessing facilities--This project will require no 
permanent facility/structures and encompasses a large area. 
Construction and deconstruction of barriers for a moving camp would 
increase potential human--polar bear interactions and impacts to polar 
bear habitat;
     Employ protected species observers (PSOs) for monitoring, 
recording, reporting, and implementing mitigation measures--All 
personnel will be trained in wildlife observation, employment of PSOs 
would not be anticipated to reduce impacts to polar bears. Monitoring, 
recording, reporting are described in the IHA application;
     Avoid areas of high-density polar bear use (e.g., barrier 
islands and coastline) including the establishment of camps and pads--
This measure is not practicable because the legacy wells that this 
project is focused on are all located along the coastline, and snow 
trail must also cross through these areas to reach the well sites;
     Avoid predominantly coastal routes for flight pathways--
This measure is not practicable because the remediation sites are 
located along the coast, and aviation access routes to project sites 
must occur over the coast; and
     Restrict activity and travel over polar bear denning 
habitat to eliminate or lessen risk of den collapse--This project has 
activities that will travel over potential polar bear denning habitat. 
The BLM has committed to multiple effective mitigation measures to 
minimize their potential impacts to polar bear denning habitat and 
reduce to chance of den collapse. Therefore, we believe that the 
probability of this project's activities causing a den collapse is near 
zero and additional mitigation measures would not further reduce the 
probability.

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 of 12 
SBS polar bears by Level B harassment during the proposed harassment 
authorization 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

    Under the Endangered Species Act (ESA) (16 U.S.C. 1536(a)(2)), all 
Federal agencies are required to ensure the actions they authorize are 
not likely to jeopardize the continued existence of any threatened or 
endangered species or result in destruction or adverse modification of 
critical habitat. Prior to issuance of a final IHA, the FWS 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 https://ecos.fws.gov/ecp/report/biological-opinion.

Government-to-Government Consultation

    It is our responsibility to communicate and work directly on a 
Government-to-Government basis with federally recognized Alaska Native 
Tribes in developing programs for healthy ecosystems. We 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 Tribal organizations and communities. Our efforts are guided 
by the following policies and directives:
    (1) The Native American Policy of the FWS (January 20, 2016);
    (2) The Alaska Native Relations Policy (currently in draft form; 
see 87 FR 66255, November 3, 2022);
    (3) Executive Order 13175 (January 9, 2000);
    (4) Department of the Interior Secretarial Orders 3206 (June 5, 
1997), 3225 (January 19, 2001), 3317 (December 1, 2011), 3342 (October 
21, 2016), and 3403 (November 15, 2021) as well as Director's Order 227 
(September 8, 2022);
    (5) The Alaska Government-to-Government Policy (a departmental 
memorandum issued January 18, 2001); and
    (6) the Department of the Interior's policies on consultation with 
Alaska Native Tribes and organizations.
    We have evaluated possible effects of the proposed IHA on federally 
recognized Alaska Native Tribes and ANCSA (Alaska Native Claims 
Settlement Act) Corporations. The FWS has determined that authorizing 
the Level B harassment of up to 12 polar bears from the BLM's specified 
activities would not have any Tribal implications or ANCSA Corporation 
implications and, therefore, Government-to-Government consultation or 
Government-to-ANCSA Corporation consultation is not necessary. However, 
we invite continued discussion, either about the project and its 
impacts or about our coordination and information exchange throughout 
the IHA/POC public comment process.

Paperwork Reduction Act

    This proposed IHA does not contain any new collection of 
information that requires approval by the Office of Management and 
Budget (OMB) under the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 
et seq.). The OMB has previously approved the information collection 
requirements associated with IHAs and assigned OMB Control Number 1018-
0194 (expires 08/31/

[[Page 2733]]

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, for 1 year from date of issuance, the 
nonlethal, incidental take by Level B harassment of up to 12 polar 
bears from the SBS stock of polar bears for activities associated with 
the BLM's oil well plugging and reclamation, soil sampling, snow trail, 
pad, and airstrip construction, and summer cleanup activities in the 
North Slope Borough of Alaska between Wainwright and Oliktok. 
Authorized take will be limited to Level B harassment only, i.e., 
disruption of behavioral patterns, and not anticipated to incur any 
significant impacts to either individual- or population-level fitness. 
We do not anticipate or authorize any take by Level A harassment, 
lethal take, or any other injury.

A. General Conditions for the IHA for the BLM

    1. Activities must be conducted in the manner described in the 
revised Request dated August 2024 (received August 26, 2024) for an IHA 
and in accordance with all applicable conditions and mitigation 
measures. The taking of polar bears whenever the required conditions, 
mitigation, monitoring, and reporting measures are not fully 
implemented as required by the IHA is prohibited. Failure to follow the 
measures specified both in the revised Request and within this proposed 
authorization may result in the modification, suspension, or revocation 
of the IHA.
    2. If project activities cause unauthorized take (i.e., take of 
more than 12 polar bears from the SBS stock by Level B harassment or a 
form of take other than Level B harassment, or take of 1 or more polar 
bears through methods not described in the IHA), then BLM 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, aircraft pilots, and vehicle 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 the BLM's revised Request. 
Changes to the proposed project without prior authorization may 
invalidate the IHA.
    5. The BLM's revised Request is approved and fully incorporated 
into this IHA unless exceptions are specifically noted herein. The 
revised Request includes:
    i. The BLM's original Request for an IHA, dated June 2024, 
(received by the FWS June 17, 2024) which includes the BLM's Polar Bear 
Safety, Awareness, and Interaction Plan and geospatial files; and
    ii. The BLM's revised Request for an IHA, dated August 2024 
(received by the FWS August 26, 2024).
    6. Operators will allow the FWS personnel or the FWS's designated 
representative to visit project work sites to monitor for impacts to 
polar bears and subsistence uses of polar bears at any time throughout 
project activities so long as it is safe to do so. ``Operators'' are 
all personnel operating under the BLM's authority, including all 
contractors and subcontractors.
    The BLM must implement the following policies and procedures to 
avoid interactions and minimize to the greatest extent practicable any 
adverse impacts on polar bears, their habitat, and the availability of 
these marine mammals for subsistence uses.

B. General Avoidance Measures

    1. The BLM must cooperate with the FWS and other designated 
Federal, State, and local agencies to monitor and mitigate the impacts 
of activities on polar bears.
    2. Trained and qualified personnel must be designated to monitor 
for the presence of polar bears, initiate mitigation measures, and 
monitor, record, and report the effects of the activities on polar 
bears. The BLM must provide all operators with polar bear awareness 
training prior to their participation in project activities.
    3. An FWS-approved polar bear safety, awareness, and interaction 
plan must be on file with the FWS Marine Mammal Management office and 
available onsite. 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 avoidance and encounter procedures; and
    vi. Polar bear observation and reporting procedures.
    4. The BLM must contact potentially affected subsistence 
communities and hunter organizations to discuss potential conflicts 
caused by the activities and provide the FWS documentation of 
communications as described in D. Measures To Reduce Impacts to 
Subsistence Users.
    5. Mitigation measures for aircraft. The BLM 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 
polar bears.
    ii. Fixed-wing aircraft and helicopter operations within the IHA 
area must maintain a minimum altitude of 457 m (1,500 ft) above ground 
level when safe and operationally possible.
    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 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. If weather conditions or operational 
constraints necessitate operation of aircraft at altitudes below 457 m 
(1,500 ft), the operator must avoid areas of known polar bear 
concentrations and should take 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 from a group (i.e., two or more polar bears).
    6. Mitigation measures for winter activities. The BLM must 
undertake the following activities to limit disturbance around known 
polar bear dens:
    i. The BLM 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, 2024, and the 
second survey obtained must occur between December 15, 2024, and 
January 10, 2025, with at least 24 hours occurring between the 
completion of the first survey and the beginning of the second survey.
    ii. All observed or suspected polar bear dens must be reported to 
the FWS prior to the initiation of activities.

[[Page 2734]]

    iii. If a suspected den site is located, the BLM 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 a 1.6-km (1-mi) operational exclusion 
zone around all putative polar bear dens during the denning season 
(November-April, or until the female and cubs leave the areas). Should 
a suspected den be discovered within 1 mile of activities, work must 
cease, and the FWS must be 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 BLM 
must comply with any additional measures specified.
    v. In determining the denning habitat that requires surveys, the 
den habitat map developed by the USGS should be used. A map of 
potential coastal polar bear denning habitat can be found at: https://www.usgs.gov/centers/asc/science/polar-bear-maternal-denning?qt-science_center_objects=4#qt-science_center_objects.

C. Monitoring

    1. Operators must provide onsite observers and implement the FWS-
approved polar bear 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.
    2. Onsite observers must be present during all operations and must 
record all polar bear observations, identify and document potential 
harassment, and work with personnel to implement appropriate mitigation 
measures.
    3. Operators shall cooperate with the FWS and other designated 
Federal, State, and local agencies to monitor the impacts of project 
activities on polar bears. Where information is insufficient to 
evaluate the potential effects of activities on polar bears and the 
subsistence use of this species, the BLM 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

    The BLM must conduct its activities in a manner that, to the 
greatest extent practicable, minimizes adverse impacts on the 
availability of polar bears for subsistence uses.
    1. The BLM will be required to develop a FWS-approved POC if, 
through community consultation, concerns are raised regarding impacts 
to subsistence harvest or Alaska Native Tribes and organizations.
    2. If an FWS-approved POC is required, the BLM will implement that 
POC
    3. Prior to conducting the work, the BLM will take the following 
steps to reduce potential effects on subsistence harvest of polar 
bears:
    i. Avoid work in areas of known polar bear subsistence harvest;
    ii. Notify the cities Wainwright and Utqiagvik and the Native 
Villages of Atqasuk and 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 polar bears;
    iv. If any unresolved or ongoing concerns of potentially affected 
Alaska Native Tribal organizations and corporations remain, modify the 
POC in consultation with the FWS and subsistence stakeholders to 
address these concerns; and
    v. Implement FWS-required mitigation measures that will reduce 
impacts to subsistence users and their resources.

E. Reporting Requirements

    The BLM must report the results of monitoring to the FWS Marine 
Mammals Management office via email at: [email protected].
    1. In-season monitoring reports.
    2. Activity progress reports. The BLM must:
    (i) Notify the FWS at least 48 hours prior to the onset of 
activities;
    (ii) Provide the FWS weekly progress reports of any significant 
changes in activities and/or locations; and
    (iii) Notify the FWS within 48 hours after ending of activities.
    3. Polar bear observation reports. The BLM 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.
    4. Human-polar bear interaction reports. The BLM 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 
the injury or death of a polar bear occurs. Reports must include all 
information specified for an observation report in paragraphs (3)(i)-
(xiv) of this section E, 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.
    6. Final report. The results of monitoring and mitigation efforts 
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;

[[Page 2735]]

    iv. Analysis of factors affecting the visibility and detectability 
of polar bears during monitoring;
    v. Analysis of the effectiveness of mitigation measures;
    vi. A summary and analysis of the distribution, abundance, and 
behavior of all polar bears observed; and
    vii. Estimates of take in relation to the specified activities.

Request for Public Comments

    If you wish to comment on this proposed authorization, the 
associated draft environmental assessment, or both documents, you may 
submit your comments by either of the methods described in ADDRESSES. 
Please identify whether 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 proposed authorization, 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 from public review your personal identifying 
information, we cannot guarantee that we will be able to do so.

Peter Fasbender,
Assistant Regional Director--Fisheries and Ecological Services, Alaska 
Region.
[FR Doc. 2025-00450 Filed 1-10-25; 8:45 am]
BILLING CODE 4333-15-P