[Federal Register Volume 86, Number 148 (Thursday, August 5, 2021)]
[Rules and Regulations]
[Pages 42982-43074]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-16452]



[[Page 42981]]

Vol. 86

Thursday,

No. 148

August 5, 2021

Part II





Department of the Interior





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Fish and Wildlife Service





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50 CFR Part 18





Marine Mammals; Incidental Take During Specified Activities; North 
Slope, Alaska; Final Rule

  Federal Register / Vol. 86 , No. 148 / Thursday, August 5, 2021 / 
Rules and Regulations  

[[Page 42982]]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 18

Docket No. FWS-R7-ES-2021-0037; FXES111607MRG01-212-FF07CAMM00]
RIN 1018-BF13


Marine Mammals; Incidental Take During Specified Activities; 
North Slope, Alaska

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service, in response to a 
request from the Alaska Oil and Gas Association, finalize regulations 
authorizing the nonlethal, incidental, unintentional take by harassment 
of small numbers of polar bears and Pacific walruses during year-round 
oil and gas industry activities in the Beaufort Sea (Alaska and the 
Outer Continental Shelf) and adjacent northern coast of Alaska. Take 
may result from oil and gas exploration, development, production, and 
transportation activities occurring for a period of 5 years. These 
activities are similar to those covered by the previous 5-year Beaufort 
Sea incidental take regulations effective from August 5, 2016, through 
August 5, 2021. This rule authorizes take by harassment only. No lethal 
take is authorized. We will issue Letters of Authorization, upon 
request, for specific activities in accordance with these regulations.

DATES: This rule is effective August 5, 2021, and remains effective 
through August 5, 2026.

ADDRESSES: You may view this rule, the associated final environmental 
assessment and U.S. Fish and Wildlife Service finding of no significant 
impact (FONSI), and other supporting material at http://www.regulations.gov under Docket No. FWS-R7-ES-2021-0037, or these 
documents may be requested as described under FOR FURTHER INFORMATION 
CONTACT.

FOR FURTHER INFORMATION CONTACT: Marine Mammals Management, U.S. Fish 
and Wildlife Service, 1011 East Tudor Road, MS-341, Anchorage, AK 
99503, Telephone 907-786-3844, or Email: [email protected]. 
Persons who use a telecommunications device for the deaf (TDD) may call 
the Federal Relay Service (FRS) at 1-800-877-8339, 24 hours a day, 7 
days a week.

SUPPLEMENTARY INFORMATION: 

Immediate Promulgation

    In accordance with the Administrative Procedure Act (APA; 5 U.S.C. 
553(d)(3)), we find that we have good cause to make this rule effective 
less than 30 days after publication. Immediate promulgation of the rule 
will ensure that the applicant will implement mitigation measures and 
monitoring programs in the geographic region that reduce the risk of 
harassment of polar bears (Ursus maritimus) and Pacific walruses 
(Odobenus rosmarus divergens) by their activities.

Executive Summary

    In accordance with the Marine Mammal Protection Act (MMPA) of 1972, 
as amended, and its implementing regulations, we, the U.S. Fish and 
Wildlife Service (Service or we), finalize incidental take regulations 
(ITRs) that authorize the nonlethal, incidental, unintentional take of 
small numbers of Pacific walruses and polar bears during oil and gas 
industry (hereafter referred to as ``Industry'') activities in the 
Beaufort Sea and adjacent northern coast of Alaska, not including lands 
within the Arctic National Wildlife Refuge, for a 5-year period. 
Industry operations include similar types of activities covered by the 
previous 5-year Beaufort Sea ITRs effective from August 5, 2016, 
through August 5, 2021 (81 FR 52276).
    This rule is based on our findings that the total takings of 
Pacific walruses (walruses) and polar bears during Industry activities 
will impact no more than small numbers of animals, will have a 
negligible impact on these species or stocks, and will not have an 
unmitigable adverse impact on the availability of these species or 
stocks for taking for subsistence uses by Alaska Natives. We base our 
findings on past and proposed future monitoring of the encounters and 
interactions between these species and Industry; species research; oil 
spill risk assessments; potential and documented Industry effects on 
these species; natural history and conservation status information of 
these species; and data reported from Alaska Native subsistence 
hunters. We have prepared a National Environmental Policy Act (NEPA) 
environmental assessment (EA) in conjunction with this rulemaking and 
determined that this final action will result in a finding of no 
significant impact (FONSI).
    These regulations include permissible methods of nonlethal taking; 
mitigation measures to ensure that Industry activities will have the 
least practicable adverse impact on the species or stock, their 
habitat, and their availability for subsistence uses; and requirements 
for monitoring and reporting. Compliance with this rule is not expected 
to result in significant additional costs to Industry, and any costs 
are minimal in comparison to those related to actual oil and gas 
exploration, development, and production operations.

Background

    Section 101(a)(5)(A) of the Marine Mammal Protection Act (MMPA; 16 
U.S.C. 1371(a)(5)(A)) gives the Secretary of the Interior (Secretary) 
the authority to allow the incidental, but not intentional, taking of 
small numbers of marine mammals, in response to requests by U.S. 
citizens (as defined in 50 CFR 18.27(c)) engaged in a specified 
activity (other than commercial fishing) within a specified geographic 
region. The Secretary has delegated authority for implementation of the 
MMPA to the U.S. Fish and Wildlife Service. According to the MMPA, the 
Service shall allow this incidental taking if we find the total of such 
taking for a 5-year period or less:
    (1) Will affect only small numbers of marine mammals of a species 
or population stock;
    (2) will have no more than a negligible impact on such species or 
stocks;
    (3) will not have an unmitigable adverse impact on the availability 
of such species or stocks for taking for subsistence use by Alaska 
Natives; and
    (4) we issue regulations that set forth:
    (a) Permissible methods of taking;
    (b) other means of effecting the least practicable adverse impact 
on the species or stock and its habitat, and on the availability of 
such species or stock for subsistence uses; and
    (c) requirements for monitoring and reporting of such taking.
    If final regulations allowing such incidental taking are issued, we 
may then subsequently issue Letters of Authorization (LOAs), upon 
request, to authorize incidental take during the specified activities.
    The term ``take'' as defined by the MMPA, means to harass, hunt, 
capture, or kill, or attempt to harass, hunt, capture, or kill any 
marine mammal (16 U.S.C. 1362(13)). Harassment, as defined by the MMPA, 
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

[[Page 42983]]

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) (16 U.S.C. 1362(18)).
    The terms ``negligible impact'' and ``unmitigable adverse impact'' 
are defined in title 50 of the CFR at 50 CFR 18.27 (the Service's 
regulations governing small takes of marine mammals incidental to 
specified activities). ``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 
for promulgating incidental take regulations (ITRs) 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 takes of marine mammals and evaluate if 
that take 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 ITR, we ensure the least 
practicable adverse impact by requiring mitigation measures that are 
effective in reducing the impact of Industry activities but are not so 
restrictive as to make Industry activities unduly burdensome or 
impossible to undertake and complete.
    In this ITR, the term ``Industry'' includes individuals, companies, 
and organizations involved in exploration, development, production, 
extraction, processing, transportation, research, monitoring, and 
support services of the petroleum industry that were named in the 
request for this regulation. Industry activities may result in the 
incidental taking of Pacific walruses and polar bears.
    The MMPA does not require Industry to obtain an incidental take 
authorization; however, any taking that occurs without authorization is 
a violation of the MMPA. Since 1993, the oil and gas industry operating 
in the Beaufort Sea and the adjacent northern coast of Alaska has 
requested and we have issued ITRs for the incidental take of Pacific 
walruses and polar bears within a specified geographic region during 
specified activities. For a detailed history of our current and past 
Beaufort Sea ITRs, refer to the Federal Register at 81 FR 52276, August 
5, 2016; 76 FR 47010, August 3, 2011; 71 FR 43926, August 2, 2006; and 
68 FR 66744, November 28, 2003. The current regulations are codified at 
50 CFR part 18, subpart J (Sec. Sec.  18.121 to 18.129).

Summary of Request

    On June 15, 2020, the Service received a request from the Alaska 
Oil and Gas Association (AOGA) on behalf of its members and other 
participating companies to promulgate regulations for nonlethal 
incidental take of small numbers of walruses and polar bears in the 
Beaufort Sea and adjacent northern coast of Alaska for a period of 5 
years (2021-2026) (hereafter referred to as ``the Request''). We 
received an amendment to the Request on March 9, 2021, which was deemed 
adequate and complete. The amended Request is available at 
www.regulations.gov at Docket No. FWS-R7-ES-2021-0037.
    The AOGA Request requested regulations that will be applicable to 
the oil and gas exploration, development, and production, extraction, 
processing, transportation, research, monitoring, and support 
activities of multiple companies specified in the Request. This 
includes AOGA member and other non-member companies that have applied 
for these regulations and their subcontractors and subsidiaries that 
plan to conduct oil and gas operations in the specified geographic 
region. Members of AOGA represented in the Request are: Alyeska 
Pipeline Service Company, BlueCrest Energy, Inc., Chevron Corporation, 
ConocoPhillips Alaska, Inc. (CPAI), Eni U.S. Operating Co. Inc. (Eni 
Petroleum), ExxonMobil Alaska Production Inc. (ExxonMobil), Furie 
Operating Alaska, LLC, Glacier Oil and Gas Corporation (Glacier), 
Hilcorp Alaska, LLC (Hilcorp), Marathon Petroleum, Petro Star Inc., 
Repsol, and Shell Exploration and Production Company (Shell).
    Non-AOGA companies represented in the Request are: Alaska Gasline 
Development Corporation (AGDC), Arctic Slope Regional Corporation 
(ASRC) Energy Services, Oil Search (Alaska), LLC, and Qilak LNG, Inc. 
This rule applies only to AOGA members, the non-members noted above, 
their subsidiaries and subcontractors, and companies that have been or 
will be acquired by any of the above. The activities and geographic 
region specified in AOGA's Request and considered in this rule are 
described below in the sections titled Description of Specified 
Activities and Description of Specified Geographic Region.

Summary of Changes From the Proposed ITR

    In preparing this final rule for the incidental take of polar bears 
and Pacific walruses, we reviewed and considered comments and 
information from the public on our proposed rule published in the 
Federal Register on June 1, 2021 (86 FR 29364). We also reviewed and 
considered comments and information from the public for our draft 
environmental assessment (EA). Based on those considerations, we are 
finalizing these regulations with the following changes from our 
proposed rule:
     The Service revised language to state: ``Aircraft 
operations within the ITR area should maintain an altitude of 1,500 ft 
above ground level when safe and operationally possible.'' The 
inclusion of ``safe and'' is essential to clarify that this altitude 
recommendation applies only when it is safe to do so (in addition to 
when it is ``operationally possible'').
     The Service added language to state that, where 
information is insufficient to evaluate the potential effects of 
activities on walruses, polar bears, and the subsistence use of these 
species, holders of an LOA may be required to participate in joint 
monitoring and/or research efforts to address these information needs 
and ensure the least practicable impact to these resources.
     The Service added language specifying that a group be 
defined for both walruses and polar bears as being two or more 
individuals.
     The Service added language that clarifies that the correct 
geographic region to which the ITRs will apply is 50 miles offshore, 
not 200 miles offshore.
     The Service has revised Table 1 in the preamble to include 
details regarding the sound measurement units and included peak SPL for 
impulsive sound sources. The Service has also

[[Page 42984]]

revised references to past ITR Level B harassment and TTS thresholds.
     The Service has added clarifying language to reflect the 
numbers of leases and land area in the NPR-A to reflect 307 leases 
covering 2.6 million acres.
     The Service added a recent peer-reviewed article, ``Polar 
bear behavioral response to vessel surveys in northeastern Chukchi Sea, 
2008-2014'' by Lomac-MacNair et al. (2021), which assisted with the 
analysis of behavioral responses of polar bears to vessel activity.
     The Service has clarified our discussion regarding the 
conclusions we drew from the peer-reviewed article ``Aquatic behaviour 
of polar bears (Ursus maritimus) in an increasingly ice-free Arctic.'' 
Lone, et al. 2018.
     The Service added language to clarify information 
requirements from applicants for LOAs and have clarified our discussion 
regarding monthly human occupancy.
     The Service added clarifying language to Sec.  
18.126(b)(4) to limit disturbance around dens, including putative and 
verified dens.
     The Service has removed the term ``other substantially 
similar'' when describing what proposed activities are covered under 
these ITRs.

Description of the Regulations

    This rule does not authorize or ``permit'' the specified activities 
to be conducted by the applicant. Rather, it authorizes the nonlethal, 
incidental, unintentional take of small numbers of Pacific walruses and 
polar bears that may result from Industry activities based on standards 
set forth in the MMPA. The Bureau of Ocean Energy Management (BOEM), 
the Bureau of Safety and Environmental Enforcement, the U.S. Army Corps 
of Engineers, and the Bureau of Land Management (BLM) are responsible 
for permitting activities associated with Industry activities in 
Federal waters and on Federal lands. The State of Alaska is responsible 
for permitting Industry activities on State lands and in State waters. 
The regulations include:
     Permissible methods of nonlethal taking;
     Measures designed to ensure the least practicable adverse 
impact on Pacific walruses and polar bears and their habitat, and on 
the availability of these species or stocks for subsistence uses; and
     Requirements for monitoring and reporting.

Description of Letters of Authorization (LOAs)

    An LOA is required to conduct activities pursuant to an ITR. Under 
this ITR, entities intending to conduct the specific activities 
described in these regulations may request an LOA for the authorized 
nonlethal, incidental Level B harassment of walruses and polar bears. 
Per AOGA's Request, such entities would be limited to the companies, 
groups, individuals specified in AOGA's Request, their subsidiaries or 
subcontractors, and their successors-in-interest. Requests for LOAs 
must be consistent with the activity descriptions and mitigation and 
monitoring requirements of the ITR and be received in writing at least 
90 days before the activity is to begin. Requests must include (1) an 
operational plan for the activity; (2) a digital geospatial file of the 
project footprint, (3) estimates of monthly human occupancy (i.e., a 
percentage that represents the amount of the month that at least one 
human is occupying a given location) of project area; (4) a walrus and/
or polar bear interaction plan, (5) a site-specific marine mammal 
monitoring and mitigation plan that specifies the procedures to monitor 
and mitigate the effects of the activities on walruses and/or polar 
bears, including frequency and dates of aerial infrared (AIR) surveys 
if such surveys are required, and (6) Plans of Cooperation (described 
below). Once this information has been received, we will evaluate each 
request and issue the LOA if we find that the level of taking will be 
consistent with the findings made for the total taking allowable under 
the ITR and all other requirements of these regulations are met. We 
must receive an after-action report on the monitoring and mitigation 
activities within 90 days after the LOA expires. For more information 
on requesting and receiving an LOA, refer to 50 CFR 18.27.

Description of Plans of Cooperation (POCs)

    A POC is a documented plan describing measures to mitigate 
potential conflicts between Industry activities and Alaska Native 
subsistence hunting. The circumstances under which a POC must be 
developed and submitted with a request for an LOA are described below.
    To help ensure that Industry activities do not have an unmitigable 
adverse impact on the availability of the species for subsistence 
hunting opportunities, all applicants requesting an LOA under this ITR 
must provide the Service documentation of communication and 
coordination with Alaska Native communities potentially affected by the 
Industry activity and, as appropriate, with representative subsistence 
hunting and co-management organizations, such as the North Slope 
Borough, the Alaska Nannut Co-Management Council (ANCC), and Eskimo 
Walrus Commission (EWC), among others. If Alaska Native communities or 
representative subsistence hunting organizations express concerns about 
the potential impacts of project activities on subsistence activities, 
and such concerns are not resolved during this initial communication 
and coordination process, then a POC must be developed and submitted 
with the applicant's request for an LOA. In developing the POC, 
Industry representatives will further engage with Alaska Native 
communities and/or representative subsistence hunting organizations to 
provide information and respond to questions and concerns. The POC must 
provide adequate measures to ensure that Industry activities will not 
have an unmitigable adverse impact on the availability of walruses and 
polar bears for Alaska Native subsistence uses.

Description of Specified Geographic Region

    The specified geographic region covered by the requested ITR 
(Beaufort Sea ITR region (Figure 1)) encompasses all Beaufort Sea 
waters (including State waters and Outer Continental Shelf waters as 
defined by BOEM) east of a north-south line extending from Point Barrow 
(N71.39139, W156.475, BGN 1944) to the Canadian border, except for 
marine waters located within the Arctic National Wildlife Refuge 
(ANWR). The offshore boundary extends 80.5 km (50 mi) offshore. The 
onshore boundary includes land on the North Slope of Alaska from Point 
Barrow to the western boundary of ANWR. The onshore boundary is 40 km 
(25 mi) inland. No lands or waters within the exterior boundaries of 
ANWR are included in the Beaufort Sea ITR region. The geographical 
extent of the Beaufort Sea ITR region (approximately 7.9 million 
hectares (ha) (~19.8 million acres (ac))) is smaller than the region 
covered in previous regulations (approximately 29.8 million ha (~73.6 
million ac) were included in the ITR set forth via the final rule that 
published at 81 FR 52276, August 5, 2016).
BILLING CODE 4333-15-P

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[GRAPHIC] [TIFF OMITTED] TR05AU21.000

BILLING CODE 4333-15-C

Description of Specified Activities

    This section first summarizes the type and scale of Industry 
activities anticipated to occur in the Beaufort Sea ITR region from 
2021 to 2026 and then provides more detailed specific information on 
these activities. Year-round onshore and offshore Industry activities 
are anticipated. During the 5 years that the ITR will be in place, 
Industry activities are expected to be generally similar in type, 
timing, and effect to activities evaluated under the prior ITRs. Due to 
the large number of variables affecting Industry activities, prediction 
of exact dates and locations of activities is not possible in a request 
for a 5-year ITR. However, operators must provide specific dates and 
locations of activities in their requests for LOAs. Requests for LOAs 
for activities and impacts that exceed the scope of analysis and 
determinations for this ITR will not be issued. Additional information 
is available in the AOGA Request for an ITR at: www.regulations.gov in 
Docket No. FWS-R7-ES-2021-0037.

Exploration Activities

    AOGA's exploration activities specified in the Request are for the 
purpose of exploring subsurface geology, water depths, and seafloor 
conditions to help inform development and production projects that may 
occur in those areas. Exploration survey activities include 
geotechnical site investigations, reflection seismic exploration, 
vibroseis, vertical seismic profiles, seafloor imagery collection, and 
offshore bathymetry collection. Exploratory drilling and development 
activities include onshore ice pad and road development, onshore gravel 
pad and road development, offshore ice road development, and artificial 
island development.
    The location of new exploration activities within the specified 
geographic region of this rule will be influenced by the location of 
current leases as well as any new leases acquired via potential future 
Federal and State of Alaska oil and gas lease sales.
BOEM Outer Continental Shelf Lease Sales
    BOEM manages oil and gas leases in the Alaska Outer Continental 
Shelf (OCS) region, which encompasses 242 million ha (600 million ac). 
Of that acreage, approximately 26 million ha (~65 million ac) are 
within the Beaufort Sea Planning Area. Ten lease sales have been held 
in this area since 1979, resulting in 147 active leases, where 32 
exploratory wells were drilled. Production has occurred on one joint

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Federal/State unit, with Federal oil production accounting for more 
than 28.7 million barrels (bbl) (1 bbl = 42 U.S. gallons or 159 liters) 
of oil since 2001 (BOEM 2016). Details regarding availability of future 
leases, locations, and acreages are not yet available, but exploration 
of the OCS may continue during the 2021-2026 timeframe of the ITR. 
Lease Sale 242, previously planned in the Beaufort Sea during 2017 
(BOEM 2012), was cancelled in 2015. BOEM issued a notice of intent to 
prepare an environmental impact statement (EIS) for the 2019 Beaufort 
Sea lease sale in 2018 (83 FR 57749, November 16, 2018). The 2019-2024 
Draft Proposed Program included three OCS lease sales, with one each in 
2019, 2021, and 2023, but has not been approved. Information on the 
Alaska OCS Leasing Program can be found at: https://www.boem.gov/about-boem/alaska-leasing-office.
National Petroleum Reserve--Alaska
    The BLM manages the 9.2 million-ha (22.8 million-ac) Natural 
Petroleum Reserve--Alaska (NPR-A), of which 1.3 million ha (3.2 million 
ac) occur within the Beaufort Sea ITR region. Lease sales have occurred 
regularly in the NPR-A; 15 oil and gas lease sales have been held in 
the NPR-A since 1999. There are currently 307 leases covering more than 
1,052,182 ha (2.6 million ac) in the NPR-A. Current operator/ownership 
information is available on the BLM NPR-A website at https://www.blm.gov/programs/energy-and-minerals/oil-and-gas/leasing/regional-lease-sales/alaska.
State of Alaska Lease Sales
    The State of Alaska Department of Natural Resources (ADNR), Oil and 
Gas Division, holds annual lease sales of State lands available for oil 
and gas development. Lease sales are organized by planning area. Under 
areawide leasing, the State offers all available State acreage not 
currently under lease within each area annually. AOGA's Request 
includes activities in the State's North Slope and Beaufort Sea 
planning areas. Lease sale data are available on the ADNR website at: 
https://dog.dnr.alaska.gov/Services/BIFAndLeaseSale. Projected 
activities may include exploration, facility maintenance and 
construction, and operation activities.
    The North Slope planning area has 1,225 tracts that lie between the 
NPR-A and the ANWR. The southern boundary of the North Slope sale area 
is the Umiat baseline. Several lease sales have been held to date in 
this leasing area. As of May 2020, there are 1,505 active leases on the 
North Slope, encompassing 1.13 ha (2.8 million ac), and 220 active 
leases in the State waters of the Beaufort Sea, encompassing 244,760 ha 
(604,816 ac). The Beaufort Sea Planning Area encompasses a gross area 
of approximately 687,966 ha (1.7 million ac) divided into 572 tracts 
ranging in size from 210 to 2,330 ha (520 to 5,760 ac).

Development Activities

    Industry operations during oil and gas development may include 
construction of roads, pipelines, waterlines, gravel pads, work camps 
(personnel, dining, lodging, and maintenance facilities), water 
production and wastewater treatment facilities, runways, and other 
support infrastructure. Activities associated with the development 
phase include transportation activities (automobile, airplane, and 
helicopter); installation of electronic equipment; well drilling; drill 
rig transport; personnel support; and demobilization, restoration, and 
remediation work. Industry development activities are often planned or 
coordinated by unit. A unit is composed of a group of leases covering 
all or part of an accumulation of oil and/or gas. Alaska's North Slope 
oil and gas field primary units include: Duck Island Unit (Endicott), 
Kuparuk River Unit, Milne Point Unit, Nikaitchuq Unit, Northstar Unit, 
Point Thomson Unit, Prudhoe Bay Unit, Badami Unit, Oooguruk Unit, Bear 
Tooth Unit, Pikka Unit, and the Colville River and Greater Mooses Tooth 
Units, which for the purposes of this ITR are combined into the Western 
North Slope.

Production Activities

    North Slope production facilities occur between the oilfields of 
the Alpine Unit in the west to Badami and Point Thomson in the east. 
Production activities include building operations, oil production, oil 
transport, facilities, maintenance and upgrades, restoration, and 
remediation. Production activities are long-term and year-round 
activities whereas exploration and development activities are usually 
temporary and seasonal. Alpine and Badami are not connected to the road 
system and must be accessed by airstrips, barges, and seasonal ice 
roads. Transportation on the North Slope is by automobile, airplanes, 
helicopters, boats, vehicles with large, low-pressure tires called 
Rolligons, tracked vehicles, and snowmobiles. Aircraft, both fixed wing 
and helicopters, are used for movement of personnel, mail, rush-cargo, 
and perishable items. Most equipment and materials are transported to 
the North Slope by truck or barge. Much of the barge traffic during the 
open-water season unloads from West Dock.
    Oil pipelines extend from each developed oilfield to the Trans-
Alaska Pipeline System (TAPS). The 122-cm (48-in)-diameter TAPS 
pipeline extends 1,287 km (800 mi) from the Prudhoe Bay oilfield to the 
Valdez Marine Terminal. Alyeska Pipeline Service Company conducts 
pipeline operations and maintenance. Access to the pipeline is 
primarily from established roads, such as the Spine Road and the Dalton 
Highway, or along the pipeline right-of-way.

Oil and Gas Support Activities

    In addition to oil and gas production and development activities, 
support activities are often performed on an occasional, seasonal, or 
daily basis. Support activities streamline and provide direct 
assistance to other activities and are necessary for Industry working 
across the North Slope and related areas. Several support activities 
are defined in AOGA's Request and include: Placement and maintenance of 
gravel pads, roads, and pipelines; supply operations that use trucks or 
buses, aircraft (fixed-wing or rotor-wing), hovercrafts, and barges/
tugs to transport people, personal incidentals (food, mail, cargo, 
perishables, and personal items) between Units and facilities; pipeline 
inspections, maintenance dredging and screeding operations; and 
training for emergency response and oil spill response. Some of these 
activities are seasonal and performed in the winter using tundra-
appropriate vehicles, such as road, pad, and pipeline development and 
inspections. Field and camp-specific support activities include: 
Construction of snow fences; corrosion and subsidence control and 
management; field maintenance campaigns; drilling; well work/work-
overs; plugging and abandonment of existing wells; waste handling (oil 
field wastes or camp wastes); camp operations (housekeeping, billeting, 
dining, medical services); support infrastructure (warehousing and 
supplies, shipping and receiving, road and pad maintenance, surveying, 
inspection, mechanical shops, aircraft support and maintenance); 
emergency response services and trainings; construction within existing 
fields to support oil field infrastructure and crude oil extraction; 
and transportation services by a variety of vehicles. Additional 
details on each of these support activities can be found in AOGA's 
Request.

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Specific Ongoing and Planned Activities at Existing Oil and Gas 
Facilities for 2021-2026

    During the regulatory period, exploration and development 
activities are anticipated to occur in the offshore and continue in the 
current oil field units, including those projects identified by 
Industry, below.
Badami Unit
    The Badami oilfield resides between the Point Thomson Unit and the 
Prudhoe Bay Unit, approximately 56 km (35 mi) east of Prudhoe Bay. No 
permanent road connections exist from Badami to other Units, such as 
Prudhoe Bay or the Dalton Highway. The Badami Unit consists of 
approximately 34 ha (85 ac) of tundra, including approximately 9.7 km 
(6 mi) of established industrial duty roads connecting all 
infrastructure, 56 km (35 mi) of pipeline, one gravel mine site, and 
two gravel pads with a total of 10 wells. The oilfield consists of the 
following infrastructure and facilities: A central processing facility 
(CPF) pad, a storage pad, the Badami airstrip pad, the Badami barge 
landing, and a 40.2-km (25-mi) pipeline that connects to Endicott.
    During the summer, equipment and supplies are transported to Badami 
by contract aircraft from Merrill Field in Anchorage or by barge from 
the West Dock in Prudhoe Bay. During winter drilling activities, a 
tundra ice road is constructed near the Badami/Endicott Pipeline to 
tie-in to the Badami CPF pad. This winter tundra ice road is the only 
land connection to the Dalton Highway and the Badami Unit. Light 
passenger trucks, dump trucks, vacuum trucks, tractor trailers, fuel 
trucks, and heavy equipment (e.g., large drill rigs, well simulation 
equipment) travel on this road during the winter season. This road also 
opens as an ADNR-permitted trail during off-years where Tuckers (a 
brand of tracked vehicle) or tracked Steigers (a brand of tractor) use 
it with sleds and snow machines. Activities related to this opening 
would be limited to necessary resupply and routine valve station 
maintenance along the oil sales pipeline corridor.
    Flights from Anchorage land at Badami Airfield (N70.13747, 
W147.0304) for a total of 32 flight legs monthly. Additionally, Badami 
transports personnel and equipment from Deadhorse to Badami Airfield. 
Approximately 24 cargo flights land at Badami Airfield annually 
depending on Unit activities and urgency. Badami also conducts aerial 
pipeline inspections. These flights are typically flown by smaller, 
charter aircrafts at a minimum altitude of 305 m (1,000 ft) at ground 
level.
    Tundra travel at Badami takes place during both the summer and 
winter season. Rolligons and Tuckers (off-road vehicles) are used 
during the summer for cargo and resupply activities but may also be 
used to access any pipelines and valve pads that are not located 
adjacent to the gravel roads. During periods of 24-hour sunlight, these 
vehicles may operate at any hour. Similar off-road vehicles are used 
during the winter season for maintenance and inspections. Temporary ice 
roads and ice pads may be built for the movement of heavy equipment to 
areas that are otherwise inaccessible for crucial maintenance and 
drilling. Ice road construction typically occurs in December or 
January; however, aside from the previously mentioned road connecting 
Badami to the Dalton Highway, ice roads are not routinely built for 
Badami. Roads are only built on an as-needed basis based on specific 
projects. Other activities performed during the winter season include 
pipeline inspections, culvert work, pigging, ground surveillance, 
geotechnical investigations, vertical support member (VSM) leveling, 
reconnaissance routes (along snow machine trails), and potentially 
spill response exercises. Road vehicles used include pickup trucks, 
vacuum trucks, loaders, box vans, excavators, and hot water trucks. 
Standard off-road vehicles include, but are not limited to, Tuckers, 
Rolligons, and snow machines.
    On occasion, crew boats, landing craft, and barges may transport 
personnel and equipment from West Dock to Badami from July through 
September, pending the open-water window. Tugs and barges may also be 
used depending on operational needs. These trips typically go from 
Badami to other coastal Units, including Endicott and Point Thomson.
    Badami performs emergency response and oil spill trainings during 
both open-water and ice-covered seasons. Smaller vessels (i.e., 
zodiacs, aluminum work boats, air boats, and bay-class boats) typically 
participate in these exercises. Future classes may utilize other 
additional equipment or vessels as needed.
    Currently, 10 wells have been drilled across the lifespan of the 
Badami Unit. Repair and maintenance activities on pipelines, culverts, 
ice roads, and pads are routine within the Badami Unit and occur year-
round. Badami's current operator has received a permit from the U.S. 
Army Corps of Engineers to permit a new gravel pad (4.04 ha [10 ac]) 
located east of the Badami Barge Landing and a new gravel pit. This new 
pad would allow the drilling of seven more deployment wells at Badami. 
All new wells would be tied back to the CPF.
Duck Island Unit (Endicott)
    Historically called the Endicott Oilfield, the Duck Island Unit is 
located approximately 16 km (10 mi) northeast of Prudhoe Bay. 
Currently, Hilcorp Alaska, LLC operates the oilfield. Endicott is the 
first offshore oilfield to continuously produce oil in the Arctic area 
of the United States and includes a variety of facilities, 
infrastructure, and islands. Endicott consists of 210 ha (522 ac) of 
land, 24 km (15 mi) of roads, 43 km (24 mi) of pipelines, two pads, and 
no gravel mine sites. The operations center and the processing center 
are situated on the 24-ha (58-ac) Main Production Island (MPI). To 
date, 113 wells have been drilled in efforts to develop the field, of 
which 73 still operate. Additionally, two satellite fields (Eider and 
Sag Delta North) are drilled from the Endicott MPI. Regular activities 
at Endicott consist of production and routine repair on the Endicott 
Sales Oil Pipeline, culverts, bridges, and bench bags. A significant 
repair on a bridge called the ``Big Skookum'' is expected to occur 
during the duration of this ITR.
    Endicott's facilities are connected by gravel roads and are 
accessible through the Dalton Highway year-round via a variety of 
vehicles (pickup trucks, vacuum trucks, loaders, box vans, excavators, 
hot water trucks). Required equipment and supplies are brought in first 
from Anchorage and Fairbanks, through Deadhorse, and then into 
Endicott. Traffic is substantial, with heavy traffic on routes between 
processing facilities and camps. Conversely, drill site access routes 
experience much less traffic with standard visits occurring twice daily 
(within a 24-hour period). Traffic at drill sites increases during 
active drilling, maintenance, or other related projects and tends to 
subside during normal operations. Hilcorp uses a variety of vehicles on 
these roads, including light passenger trucks, heavy tractor-trailer 
trucks, heavy equipment, and very large drill rigs. Ice roads are only 
built on an as-needed basis for specific projects.
    Air travel via helicopter from an established pad on Endicott to 
Deadhorse Airport is necessary only if the access bridges are washed 
out (typically mid to late May to the start of June). During such 
instances, approximately 20-30 crew flights would occur along with 
cargo flights about once a week. Hilcorp also performs

[[Page 42988]]

maternal polar bear den surveys via aircraft.
    Hilcorp performs tundra travel work during the winter season 
(December-May; based on the tundra opening dates). Activities involving 
summer tundra travel are not routine, and pipeline inspections can be 
performed using established roads. During the winter season, off-road 
vehicles (e.g., Tuckers, snow machines, or tracked utility vehicles 
called Argo centaurs) perform maintenance, pipeline inspections, 
culvert work, pigging, ground surveillance, VSM leveling, 
reconnaissance routes (snow machine trails), spill response exercises, 
and geotechnical investigations across Endicott.
    Tugs and barges are used to transport fuel and cargo between 
Endicott, West Dock, Milne, and Northstar during the July to September 
period (pending the open-water period). Trips have been as many as over 
80 or as few as 3 annually depending on the needs in the Unit, and 
since 2012, the number of trips between these fields has ranged from 6 
to 30. However, a tug and barge have been historically used once a year 
to transport workover rigs between West Dock, Endicott, and Northstar. 
Endicott performs emergency response and oil spill trainings during 
both the open-water and ice-covered seasons. Smaller vessels (i.e., 
zodiacs, Kiwi Noreens, bay-class boats) participate in these exercises; 
however, future classes may utilize other additional equipment or 
vessels (e.g., the ARKTOS amphibious emergency escape vehicle) as 
needed. ARKTOS training will not be conducted during the summer.
Kuparuk River Unit
    ConocoPhillips Alaska, Inc., operates facilities in the Kuparuk 
River Unit. This Unit is composed of several additional satellite 
oilfields (Tarn, Palm, Tabasco, West Sak, and Meltwater) containing 49 
producing drill sites. Collectively, the Greater Kuparuk Area consists 
of approximately 1,013 ha (2,504 ac) made up of 209 km (130 mi) of 
gravel roads, 206 km (128 mi) of pipelines, 4 gravel mine sites, and 
over 73 gravel pads. A maximum of 1,200 personnel can be accommodated 
at the Kuparuk Operations Center and the Kuparuk Construction Camp. The 
camps at the Kuparuk Industrial Center are used to accommodate overflow 
personnel.
    Kuparuk's facilities are all connected by gravel road and are 
accessible from the Dalton Highway year-round. ConocoPhillips utilizes 
a variety of vehicles on these roads, including light passenger trucks, 
heavy tractor-trailer trucks, heavy equipment, and very large drill 
rigs. Required equipment and supplies are flown in through Deadhorse 
and then transported via vehicle into the Kuparuk River Unit. Traffic 
has been noted to be substantial, with specific arterial routes between 
processing facilities and camps experiencing the heaviest use. 
Conversely, drill site access routes experience much less traffic with 
standard visits to drill sites occurring at least twice daily (within a 
24-hour period). Traffic at drill sites increases during drilling 
activities, maintenance, or other related projects and tends to subside 
during normal operations.
    The Kuparuk River Unit uses its own private runway (Kuparuk 
Airstrip; N70.330708, W149.597688). Crew and personnel are transported 
to Kuparuk on an average of two flights per day. Flights arrive into 
Kuparuk only on the weekdays (Monday through Friday). Year round, 
approximately 34 flights per week transport crew and personnel between 
Kuparuk and Alpine Airport. ConocoPhillips plans to replace the 
passenger flights from Alpine to Kuparuk in 2021 with direct flights to 
both Alpine and Kuparuk from Anchorage. These flights are expected to 
occur five times weekly and will replace the weekly flights from Alpine 
to Kuparuk. Cargo is also flown into Kuparuk on personnel flights. The 
single exception would be for special and specific flights when the 
Spine road is blocked. Occasionally, a helicopter will be used to 
transport personnel and equipment within the Kuparuk River Unit. These 
flights generally occur between mid-May and mid-September and account 
for an estimated 50 landings annually in Kuparuk. The location and 
duration of these flights are variable, and helicopters could land at 
the Kuparuk Airstrip or remote locations on the tundra. However, only 4 
of the estimated 50 landings are within 3.2 km (5 mi) of the coast.
    ConocoPhillips flies surveys of remote sections of the Kuparuk 
crude pipeline one to two times weekly during summer months as well as 
during winter months when there is reduced visibility from snow cover. 
During winter months, maternal den surveys are also performed using 
aircraft with mounted AIR cameras. Off-road vehicles (such as Rolligons 
and Tuckers) are used for maintenance and inspection of pipelines and 
power poles that are not located adjacent to the gravel roads. These 
vehicles operate near the road (152 m [500 ft]) and may operate for 24 
hours a day during summer months. During winter months, temporary ice 
roads and pads are built to move heavy equipment to areas that may be 
inaccessible. Winter tundra travel distances average approximately 
1,931 km (1,200 mi) with ice roads averaging approximately 17.7 km (11 
mi) and may occur at any hour of the day. Dredging and screeding occur 
annually to the extent necessary for safety, continuation of seawater 
flow, and dock stability at the Kuparuk saltwater treatment plant 
intake and at Oliktok dock. Dredging occurs within a 1.5-ha (3.7-ac) 
area, and screeding occurs within a 1-ha (2.5-ac) area. Operations are 
conducted during the open-water season (May to October annually). 
Removed material from screeding and dredging is deposited in upland 
areas above the high tide, such as along the Oliktok causeway and 
saltwater treatment plant (STP) pad. ConocoPhillips removes 
approximately 0.6 to 1.1 m (2 to 3.5 ft) of sediment per year. Dredging 
activities typically last for 21 days, and screeding activities 
typically last 12 days annually. Boats are also used to perform routine 
maintenance as needed on the STP outfalls and inlets. ConocoPhillips 
infrequently has marine vessel traffic at the Oliktok Dock.
    ConocoPhillips performs emergency response and oil spill trainings 
during both open-water and ice-covered seasons. Smaller vessels (i.e., 
zodiacs, aluminum work boats, air boats, and bay-class boats) typically 
participate in these exercises. Future classes may utilize other 
additional equipment or vessels as needed.
    The Willow Development Project, which is described in full in 
Planned Activities at New Oil and Gas Facilities for 2021-2026, would 
lead to increased activity through the Kuparuk River Unit. 
Prefabricated modules would be transported through the Unit. Module 
transportation involves an increase in road, aircraft, and vessel 
traffic resulting in the need for gravel road and gravel pad 
modifications, ice road and ice pad construction, and sea floor 
screeding. During the 2023 summer season, gravel hauling and placement 
to modify existing roads and pads used in support of the Willow 
Development would take place. An existing 12-acre gravel pad located 
13.2 km (2 mi) south of the Oliktok Dock would require the addition of 
33,411 cubic m (43,700 cubic yd) of gravel, increasing pad thickness to 
support the weight of the modules during staging. However, this 
addition of gravel would not impact the current footprint of the pad. 
Additionally, ConocoPhillips plans to widen six road curves and add 
four 0.2-ha (0.5-ac) pullouts between the Oliktok Dock and Drill Site 
2P as well as increase the thickness of the 3.2-km (2-

[[Page 42989]]

mi) gravel road from the Oliktok Dock to the staging pad--requiring 
approximately 30,811 cubic m (40,300 yd) of gravel and resulting in an 
increase in footprint of the gravel road by <0.4 ha (<0.1 ac). Twelve 
culverts are estimated to be extended within this part of the gravel 
road to accommodate the additional thickness (approximately five 
culverts per mile). This would yield a new gravel footprint with an 
additional 2 ha (5.0 ac) and 90,752 cubic m (118,700 cubic yd). In 
2025, a 6.1-ha (15-ac) ice pad, for camp placement, and an ice road for 
module transportation, would be constructed in association with the 
Willow Project. The planned location is near Drill Site 2P, over 32.2 
km (20 mi) away from the coastline.
    An increase in road traffic to Kuparuk is expected to begin in 2023 
and continue into the summer of 2026. Activities would mostly consist 
of the transportation of freight, equipment, and support crews between 
Oliktok Point, the Kuparuk Airport, and the NPR-A. The number of weekly 
flights will also increase with an average of 6 additional weekly 
flights in 2023, 4 additional flights per week in 2024, 14 additional 
flights per week in 2025, and 4 additional flights per week in 2026. 
Eight barges would deliver the prefabricated modules and bulk material 
to Oliktok Dock using existing and regularly used marine transportation 
routes in the summer of 2024 and 2026.
    Due to the current depths of water at the Oliktok Dock (2.4 m [8 
ft]), lightering barges (barges that transfer cargo between vessels to 
reduce a vessel's draft) would be used to support the delivery of large 
modules to the Dock. The location of the lightering transfer would be 
approximately 3.7 km (2.3 mi) north of Oliktok Dock in 3.05 m (10 ft) 
of water. Screeding operations would occur during the summer open-water 
season 2022-2024 and 2026 starting mid-July and take approximately one 
week to complete. The activities would impact an area of 3.9 ha (9.6 
ac) and an additional hectare (2.5 ac) in front of the Oliktok Dock to 
facilitate the unloading of the lightering barges. Bathymetry 
measurements would be taken after to confirm the appropriate conditions 
of the screeded seafloor surface.
Milne Point Unit
    The Milne Point Unit is located 56 km (35 mi) northwest of Prudhoe 
Bay, producing from three main pools, including Kuparuk, Schrader 
Bluff, and Sag River. The total development area of Milne Point is 182 
ha (450 ac), including 80 ha (198 ac) of 14 gravel pads, 54 km (33 mi) 
of gravel roads and mines, 161 km (100 mi) of pipelines, and over 330 
wells.
    Milne Point's facilities are connected by gravel roads and are 
accessible by the Dalton Highway year-round via a variety of vehicles 
(pickup trucks, vacuum trucks, loaders, box vans, excavators, hot water 
trucks). Required equipment and supplies are brought in first from 
Anchorage and Fairbanks, through Deadhorse, and then into the Milne 
Point Unit. Arterial roads between processing facilities and camps 
experience heavy traffic use. Conversely, drill site access routes 
experience much less traffic, with standard visits to drill sites 
occurring twice daily (within a 24-hour period). Traffic at drill sites 
increases during drilling activities, maintenance, or other related 
projects and tends to subside during normal operations. Industry uses a 
variety of vehicles on these roads, including light passenger trucks, 
heavy tractor-trailer trucks, heavy equipment, and very large drill 
rigs.
    Air travel via helicopter from an established pad (N70.453268, 
W149.447530) to Deadhorse Airport is necessary only if the access 
bridges are washed out (typically mid to late May to the start of 
June). During such instances, approximately 20-30 crew flights would 
occur, along with cargo flights, about once a week. Hilcorp also 
performs maternal polar bear den surveys via aircraft.
    Hilcorp uses off-road vehicles (Rolligons and Tuckers) for tundra 
travel during summer months to access any pipelines and power poles not 
found adjacent to the gravel roads. During the winter seasons, 
temporary ice roads and ice pads are built as needed across the Unit to 
move heavy equipment to areas otherwise inaccessible. Hilcorp also uses 
their off-road vehicles (Tuckers, snow machines, and Argo centaurs) 
during the winter to perform maintenance and inspections. Additionally, 
road vehicles (pickup trucks, vacuum trucks, loaders, box vans, 
excavators, and hot water trucks) are used to perform pipeline 
inspections, culvert work, pigging, ground surveillance, VSM leveling, 
reconnaissance routes (snow machine trails), potential spill response 
exercises, and geotechnical investigations.
    There are 14 pads and 2 gravel mine sites within the Milne Point 
Unit. Twenty-eight new wells are expected to be drilled over the next 7 
years. Repair activities are routine at Milne Point and occur on 
pipelines, culverts, ice roads, and pads. Hilcorp also has plans to 
continue development on Milne Point and will be running two to three 
more drilling rigs over the next 5 years--requiring several pad 
expansions to support them. Hilcorp plans to expand six pads, 
including: S Pad (4.5 ha [11 ac]), I Pad (0.81 ha [2 ac]), L Pad (0.81 
ha [2 ac]), Moose Pad (0.81 ha [2 ac]), B Pad (2.1 ha [5.3 ac]), and E 
Pad (0.4 ha [1 ac]). Additionally, Hillcorp's proposed Raven Pad is 
projected to be built in 2021 between the L and F Pads. This pad will 
be 12.1 ha (30 ac) and contain various facilities, pipelines, tie-ins, 
a new pipeline/VSM along existing routes connecting F Pad to CFP and 45 
wells.
    Hilcorp is also planning to drill at least 28 new wells with a 
potential for more over the period of the ITR. New facilities will be 
installed for polymer injections, flowlines for new wells, pipelines, 
camps, tanks, and main facility improvements. This will require the 
development of new gravel pits for mining. Some of the new facilities 
planned to be built include: Upgrades to Moose pad; F Pad Polymer 
facility installation and startup; 2020 shutdown for A-Train process 
vessel inspections and upgrades; LM2500 turbine overhaul completion; 
Raven Pad design and civil work; S Pad facility future expansion; S Pad 
polymer engineering and procurement; diesel to slop oil tank 
conversion; and I Pad redevelopment. Repair activities will be 
routinely performed on pipelines, culverts, ice roads, and pads. Power 
generation and infrastructure at L Pad and polymer injection facilities 
are also planned on Moose Pad, F Pad, J Pad, and L Pad.
    Hilcorp plans to expand the size of the Milne mine site up to 9 ha 
(22.37 ac). Approximately 6.3 ha (15.15 ac) will be mined for gravel. 
Overburden store will require about 1 ha (2.5 ac) and will be 
surrounded by a 1.3-ha (3.4-ac) buffer. Around 0.5 ha (1.32 ac) will be 
used to expand the Dalton Highway. The Ugnu Mine Site E, located 
approximately 8 km (5 mi) southeast of Oliktok Point and 3.2 km (2 mi) 
south of Simpson Lagoon, will also be expanded during the 2021-2026 
ITR. Hilcorp's planned expansion for the new cell is approximately 259 
m long by 274 m wide (850 ft long by 900 ft wide) or 7.1 ha (17.56 ac). 
This would produce an estimated 434,267 cubic m (568,000 cubic yd) of 
overburden including a 20 percent swell factor, and approximately 
764,554 cubic m (1,000,000 cubic yd) of gravel. The footprint of the 
Phase I Material Site is expected to be 6.5 ha (16 ac). Overburden 
storage, a thermal barrier, and access road would require approximately 
4.2 ha (10.3 ac). The final site layout will be dependent on gravel 
needs.

[[Page 42990]]

    Marine vessels (specifically crew boats) are used to transport 
workers from West Dock to Milne Point if bridges are washed out. 
Additionally, vessels (tugs/barges) are used to transport fuel and 
cargo between Endicott, West Dock, Milne Point, and Northstar from July 
to September. While the frequency of these trips is dependent on 
operational needs in a given year, they are typically sparse. Hilcorp 
performs several emergency response and oil spill trainings throughout 
the year during both the open-water and ice-covered season. Smaller 
vessels (i.e., zodiacs, Kiwi Noreens, bay-class boats) typically 
participate in these exercises; however, future classes may utilize 
other additional equipment or vessels (e.g., the ARKTOS amphibious 
emergency escape vehicle) as needed. ARKTOS training will not be 
conducted during the summer, though Hilcorp notes that some variation 
in activities and equipment can be expected.
Nikaitchuq Unit
    Eni U.S. Operating Co., Inc., is the 100 percent working interest 
owner and operator of the Nikaitchuq Unit. The Nikaitchuq Unit includes 
the following infrastructure: Oliktok Production Pad (OPP), Spy Island 
Drill site (SID), Nikaitchuq Operations Center (NOC), a subsea pipeline 
bundle, an onshore crude oil transmission pipeline (COTP), and an 
onshore pad that ties into the Kuparuk Pipeline (known as KPP). 
Currently, the SID includes 19 production wells, one exploration well 
on a Federal offshore lease, 14 injection wells, one Class-1 disposal 
well, and two shallow water wells. The OPP includes 12 production 
wells, 8 injection wells, 3 source water wells, 1 Class-1 disposal 
well, and 2 shallow water wells.
    Road access in the Nikaichuq Unit for the OPP, NOC, and KPP are 
through connected gravel roads from the Dalton Highway year-round and 
maintained by Kuparuk. Equipment and cargo are brought in from 
Anchorage and Fairbanks after a stopover in Deadhorse. Traffic levels 
vary depending on ongoing activities but do not change significantly 
with time of year.
    Crew and cargo are primarily transported using commercial flights 
to Deadhorse and then by vehicle. A helicopter may be used for 
transportation of personnel, the delivery and movement of supplies and 
equipment from Deadhorse when the Kuparuk Bridge is unavailable, or in 
the event of a medical emergency; however, these flights are 
infrequent. Eni utilizes off-road vehicles (Rolligons and other track 
vehicles) for both the summer and winter seasons for tundra travel; 
however, tundra travel is infrequent. Primarily, these activities would 
occur when access to the COTP between OPP and KPP is being inspected or 
under maintenance. Eni utilizes off-road vehicles during winter to 
conduct maintenance and inspections on COTP and to transport personnel, 
equipment, and supplies between the OPP and SID during periods where a 
sea ice road between the two locations is being constructed. Until the 
sea ice road is completed, vehicles travel by a single snow trail 
(approximately 6.8 km [4.25 mi]).
    Two to three ice roads are constructed within the Nikaichuq Unit 
annually. These ice roads are typically around 6.8 km (4.25 mi) long 
and 18.3 m (60 ft) wide. Traffic occurs at all hours, consisting of a 
variety of light vehicles, such as pickup trucks and sport-utility 
vehicles (SUVs), high-capacity personnel transport vehicles (busses), 
ice road construction equipment (road graders, water tankers, snow 
blowers, front end loaders, and dump trucks), vacuum trucks, and 
tractor trailers. To build the sea ice road, Eni harvests ice chips 
from Lake K-304 after constructing a 0.3-km (0.2-mi) long, 9.1-m (30-
ft) wide tundra ice road. In the past, a short tundra ice road was also 
constructed and used to access a lake to obtain water for maintenance 
of a sea ice road, and such an ice road may be used in the future.
    Maintenance activities, such as gravel and gravel bag placement 
along the subsea pipeline, may occur as needed. Routine screeding is 
generally performed near barge landings at OPP and SID. Dredging is 
also possible in this area, although not likely. Hovercrafts are used 
to transport both cargo and personnel year round but generally occur 
daily between Oliktok Point and SID during October through January and 
May through July. Crew boats with passengers, tugs, and barges are used 
to transport cargo from Oliktok Point to the SID daily during open-
water months (July through September) as needed. Eni also performs 
emergency response and oil spill trainings during both open-water and 
ice seasons.
Northstar Unit
    The Northstar Unit is made up of a 15,360-ha (38,400-ac) reservoir, 
and Hilcorp Alaska, Inc., currently operates it. Northstar is an 
artificial island located approximately 6 km (4 mi) northwest of Point 
McIntyer and 10 km (6 mi) from Prudhoe Bay. The water depth surrounding 
the island is approximately 11.9 m (39 ft) deep. Thirty wells have been 
drilled to develop Northstar, of which 23 are still operable. A buried 
subsea pipeline (58 km [36 mi] long) connects the facilities from 
Northstar to the Prudhoe Bay oilfield. Access to the island is through 
helicopter, hovercraft, boat, Tucker, and vehicle (only during the 
winter ice road season). Routine activities include maintenance and 
bench/block repairs on culvert, road, and pipelines.
    There are no established roads on Northstar Island. Loaders, 
cranes, and a telescopic material handler are used to move cargo and 
equipment. Hilcorp exclusively uses helicopters for all aircraft 
operations around the Northstar Unit, with an estimated 800 landings 
per year. Crew and cargo flights travel daily from May to January to 
Northstar Island from Deadhorse Airport. Sling-loading equipment and 
supplies may also occur from May through December. Pipeline inspections 
via aircraft are performed once weekly--generally with no landings. 
However, once per quarter, the helicopter lands to inspect the end of 
the pipeline where it enters the water (N70.404220, W148.692130).
    Only winter tundra travel occurs at Northstar. Hilcorp typically 
builds several unimproved ice trails to Northstar, including a trail 
along the pipeline corridor from the valve pad near the Dew Line site 
to Northstar (9.5 km [5.93 mi]); a trail from West Dock to the pipeline 
shore crossing, grounded ice along the coastline (7.8 km [4.82 mi]); 
two unimproved ice road paths from the hovercraft tent at the dockhead; 
one trail under the West Dock Causeway (WDC) bridge to well pad DH3 
(1.4 km [0.86 mi]); and a trail around West Dock to intersect the main 
ice road north of the STP (4.6 km [2.85 mi]). Hilcorp may also 
construct any number of shorter trails into undisturbed areas to avoid 
unstable/unsafe areas throughout the ice season. These detours may be 
constructed after March 1st due to safety considerations and may 
deviate approximately 23-46 m (75-150 ft) from the original road or 
trail.
    Hilcorp typically constructs an approximately 11.7-km (7.3-mi) long 
ice road each year between Northstar and Prudhoe Bay (specifically West 
Dock) to allow for the transportation of personnel, equipment, 
materials, and supplies. This ice road generally allows standard 
vehicles (SUVs, pickup trucks, buses, other trucks) to transport crew 
and equipment to and from the island; however, Hilcorp may elect to 
construct an ice trail that supports only light-weight vehicles 
depending on operational needs and weather conditions.

[[Page 42991]]

    During December or January before ice roads are built, Tucker 
tracked vehicles transport cargo and crew daily. During ice road 
construction, work will occur for 24 hours a day, 7 days a week, and is 
stopped only when unsafe conditions are presented (e.g., high winds, 
extremely low temperatures). Ice road construction typically begins 
around January 1st when the ice is considered thick enough (minimum of 
61 cm [24 in]) and is typically completed within 45 days of the start 
date.
    Once the ice road is built, tractor-trailer trucks transport 
freight, chemicals for resupplies (occurs every 2 weeks using 10 
truckloads), diesel, and other equipment. Additional personnel and 
smaller freight travel multiple times a day in light passenger traffic 
buses and pickup trucks. A grader and snow blower maintain the ice road 
daily, and in the event of cracks in the ice road, a loader may be 
used. Tucker tracked vehicles and hovercraft are used beginning mid-May 
as ice becomes unstable, then, as weather warms, boats and helicopters 
are used. Hilcorp uses hovercraft daily between West Dock and Northstar 
Island to transport crew and cargo (October through January and May 
through July) when broken-ice conditions are present. Crew boats have 
also been used to carry crew and cargo daily from West Dock to 
Northstar Island during open-water months (July to September) when 
hovercraft are not in use. Tugs and barges transport fuel and cargo 
from West Dock and Endicott to Northstar Island during the open-water 
season (July through September) and may be used once a year to 
transport workover rigs. There are typically 6-30 trips per year.
    Northstar performs emergency response and oil spill trainings 
during both open-water and ice-covered seasons. Smaller vessels (i.e., 
zodiacs, aluminum work boats, air boats, and bay-class boats) typically 
participate in these exercises. Future classes may utilize other 
additional equipment or vessels (e.g., the ARKTOS amphibious emergency 
escape vehicle) as needed. However, the ARKTOS training will not be 
conducted during the summer.
Oooguruk Unit
    The Oooguruk Unit was originally developed in 2008 and is operated 
by Eni, consisting of several developments and facilities including the 
Oooguruk Drill site (ODS), a 13-km (8.1-mi) long pipeline bundle, and 
the Oooguruk Tie-in Pad (OTP). The OTP is an onshore production 
facility that consists of tanks, flowlines, support infrastructure, and 
power generation facilities. The pipeline bundle consists of two oil 
pipelines, a 30.5-cm (12-in) inner diameter production flowline, and a 
5.1-cm (2-in) inner diameter diesel/base oil flowline. The bundle sits 
about 61 m (200 ft) from the shoreline when onshore and runs about 3.8 
km (2.4 mi) on vertical supports to the OTP. A 30.5-cm (12-in) product 
sales line enters a metering skid on the southeast side of the OTP. 
This metering skid represents the point where the custody of the oil is 
transferred to ConocoPhillips Alaska, Inc. Diesel fuels and base oil 
are stored at the OTP to resupply the ODS as needed.
    The ODS is a manmade island located approximately 9.2 km (5.7 mi) 
offshore and measuring approximately 5.7 ha (14 ac) and is found 
approximately 12.9 km (8 mi) northwest of the OTP. The site includes 
living quarters with 150 beds, a helicopter landing site, various 
production and injection wells, and a grind and inject facility. A 
Nabors rig is also located on the pad and the rig is currently not in 
use. The ocean surrounding the island is about 3.05 m (10 ft) in depth 
and considered relatively shallow.
    Oooguruk relies on interconnected gravel roads maintained by 
Kuparuk to gain access to the Dalton Highway throughout the year. 
Equipment and supplies travel from Anchorage and Fairbanks to the OTP 
through Deadhorse. The ODS is connected to the road system only when an 
ice road is developed and available from February to May.
    Eni uses helicopters from May to January for cargo transport, which 
is limited to flights between the OTP and the ODS. Work personnel 
depart from the Nikaitchuq Unit's NOC pad; Eni estimates about 700 
flights occur during the helicopter season for both crew and field 
personnel.
    Eni occasionally utilizes off-road vehicles (e.g., Rolligons and 
track vehicles) during the summer tundra months with activities limited 
to cleanup on ice roads or required maintenance of the pipeline bundle. 
During winter months, track vehicles transport personnel, equipment, 
and supplies between the OTP and ODS during the ice road construction 
period. The ice road is approximately 9.8-m (32-ft) wide, and traffic 
and activity are constant--most notably from light vehicles (pickup 
trucks, SUVs), high-capacity personnel transport (buses), ice road 
construction equipment (road graders, water tankers, snow blowers, 
front-end loaders, dump trucks), and well maintenance equipment (coil 
tubing units, wire-line units, hot oil trucks). Eni estimates over 
3,500 roundtrips occur annually.
    Eni will add 2,294 cubic m (3,000 cubic yd) of gravel to facilitate 
a hovercraft landing zone on island east and will also conduct 
additional gravel maintenance at the ``shoreline crossing'' of the 
pipeline or the area where the pipeline transitions from the above-
ground section to the subsea pipeline. Maintenance in these areas is 
necessary to replace gravel lost to erosion from ocean wave action. 
Additionally, Eni performs gravel placement on the subsea pipeline to 
offset strudel scour--pending the results of annual surveys. Island 
``armor'' (i.e., gravel bags) requires maintenance throughout the year 
as well.
    Eni utilizes some in-water vessel traffic to transport crew and 
cargo from Oliktok Point to the ODS during the open-water season 
(typically July to September). These trips occur daily (or less if 
hovercraft are used). Additionally, Eni uses tugs and barges to 
transport cargo from Oliktok Point to the ODS from July to September. 
These vessels make varying amounts of trips, from a few trips annually 
up to 50 trips depending on operational needs at the time.
    Like the trainings performed at the Nikaitchuq Unit, Eni would also 
conduct emergency and oil spill response trainings throughout the ITR 
period at various times. Trainings will be conducted during both open-
water and ice-covered seasons with training exercises occurring on both 
the land and the water depending on current ice conditions. Further 
information on these trainings can be found on the submitted AOGA 
Request for 2021-2026.
Point Thomson Unit
    The Point Thomson Unit (PTU) is located approximately 32 km (20 mi) 
east of the Badami field and 96 km (60 mi) east of Deadhorse and is 
operated by ExxonMobil. The Unit includes the Point Thomson initial 
production system (IPS), Sourdough Wells, and legacy exploration sites 
(i.e., PTU 1-4, Alaska C-1, West Staines State 2 and 18-9-23). The 
total Point Thomson IPS area is approximately 91 ha (225 ac), including 
12.4 km (7.7 mi) of gravel roads, 35 km (22 mi) of pipelines, one 
gravel mine site, and three gravel pads (Central, West, and C-1).
    The Point Thomson IPS facilities are interconnected by gravel roads 
but are not connected to other oilfields or developments. Equipment and 
supplies are brought in via air, barge, ice road, or tundra travel 
primarily from Deadhorse. Traffic on gravel roads within the PTU

[[Page 42992]]

occurs daily with roads from Central Pad to the airstrip experiencing 
the heaviest use. This consistent heavy use is not influenced by time 
of year. Vehicle types include light passenger trucks/vans, heavy 
tractor-trailer trucks, and heavy equipment usage on pads, particularly 
for snow removal and dust control.
    Personnel and most cargo are transported to Point Thomson using 
aircraft departing from Deadhorse. During normal operations, an average 
of two to four passenger flights per week land at the Point Thomson 
Airport. Typically, there are 12 cargo flights per year (or one per 
month) that may land at Point Thomson, but frequency is reduced January 
to April when tundra is open. Aerial pipeline inspection surveys are 
conducted weekly, and environmental surveys and operations typically 
occur for one to two weeks each summer. The environmental surveys are 
generally performed at remediation sites such as West Staines State 2 
and 18-9-23, areas of pipeline maintenance, and tundra travel routes.
    Off-road vehicles (e.g., Rolligons and track vehicles) are only 
used during the summer tundra months for emergency purposes such as 
accessing the pipeline. During winter months, off-road vehicles provide 
access to spill response conexes, deliver cargo supplies from 
Deadhorse, and maintain and inspect the PTU. Tundra travel includes a 
route south of the pipeline from Deadhorse to Point Thomson, a route 
along the pipeline right-of-way (ROW), spur roads as needed between the 
southern route and the pipeline ROW, and a route to spill conexes 
totaling approximately 146.5 km (91 mi). Travel along these routes can 
occur at any time of day.
    Temporary ice roads and pads near the Point Thomson Facility are 
built to move heavy equipment to areas otherwise inaccessible for 
maintenance and construction activities. Ice road and ice pad 
construction typically begins in December or January. An ice road to 
Point Thomson is typically needed in the event that a drilling rig 
needs to be mobilized and extends east from the Endicott Road, connects 
to the Badami facilities, and continues east along the coast to Point 
Thomson.
    Barging usually occurs from mid-July through September. In the 
event additional barging operations are needed, dredging and screeding 
activities may occur to allow barges to dock at Point Thomson. If 
dredging and screeding activities are necessary, the work would take 
place during the open-water season and would last less than a week. 
ExxonMobil also performs emergency response and oil spill trainings 
during the summer season. On occasion, spill response boats are used to 
transport operations and maintenance personnel to Badami for pipeline 
maintenance.
    Expansion activities are expected to occur over 4 years and would 
consist of new facilities and new wells on the Central Pad to increase 
gas and condensate production. The Central Pad would require a minor 
expansion of only 2.8 ha (7 ac) to the southwest. Minor size increases 
on infield pipelines will also occur, but the facility footprint would 
not otherwise increase. To support this project, an annual ice road 
would be constructed, and summer barging activities would occur to 
transport a drilling rig, additional construction camps, field 
personnel, fuel, equipment, and other supplies or materials. Gravel 
would be sourced from an existing stockpile, supplemented by additional 
gravel volume that would be sourced offsite as necessary. Drilling of 
wells is expected to occur during the later years of construction, and 
new modular production facilities would be fabricated offsite and then 
delivered via sealift.
    A small number of barge trips (<10 annually) are expected to 
deliver equipment, fuel, and supplies during the open-water season 
(mid-July through September) from Deadhorse and may occur at any time 
of day. Additional development activities are planned within PTU and 
are described in the section Alaska Liquefied Natural Gas Project 
(Alaska LNG).
Prudhoe Bay Unit
    The Prudhoe Bay Unit (PBU) is the largest producing oilfield in 
North America and is operated by Hilcorp. The PBU includes satellite 
oilfields Aurora, Borealis, Midnight Sun, Polaris, and Orion. The total 
development area is approximately 1,778 ha (4,392 ac), including 450 km 
(280 mi) of gravel roads, 2,543 km (1,580 mi) of pipelines, 4 gravel 
mines, and over 113 gravel pads. Camp facilities such as the Prudhoe 
Bay Operations Center, Main Construction Camp, Base Operations Center, 
and Tarmac camp are also within the PBU.
    PBU facilities are connected by gravel roads and can be accessed 
from the Dalton Highway year-round. Equipment and supplies are flown or 
transported over land from Anchorage and Fairbanks to Deadhorse before 
they are taken to the PBU over land. Traffic is constant across the PBU 
with arterial routes between processing facilities and camps 
experiencing the heaviest use while drill site access roads are 
traveled far less except during active drilling, maintenance, or other 
projects. Traffic is not influenced by the time of year. Vehicle types 
include light passenger trucks, heavy tractor-trailer trucks, heavy 
equipment, and very large drill rigs.
    Personnel and cargo are transported to the PBU on regularly 
scheduled, commercial passenger flights through Deadhorse and then 
transported to camp assignments via bus. Pipeline surveys are flown 
every 7 days departing from CPAI's Alpine airstrip beginning the flight 
route at Pump Station 1 and covering a variety of routes in and around 
the Gathering Center 2, Flow Station 2, Central Compressor Pad, West 
Gas Injection, and East Sag facilities. Pipelines are also surveyed 
once per day from the road system using a truck-mounted forward-looking 
infrared camera system. Various environmental studies are also 
conducted using aircraft. Surveys include polar bear den detection and 
tundra rehabilitation and revegetation studies. Tundra environmental 
studies occur annually each summer in July and August with field 
personnel being transported to sites over an average of 4 days. Flights 
take off and return to Deadhorse airport, and field landings include 
seven tundra sites an average of 25.7 km (16 mi) from Deadhorse 
airport. Only four of the seven tundra landing sites are within 8 km (5 
mi) of the Beaufort coast. Unmanned aerial systems (UAS) are used for 
subsidence, flare, stack, and facility inspections from June to 
September as well as annual flood surveillance in the spring. UAS 
depart and arrive at the same location and only fly over roads, 
pipeline ROWs, and/or within 1.6 km (1 mi) or line of sight of the pad.
    Off-road vehicles (such as Rolligons and Tuckers) are used for 
maintenance and inspection activities during the summer to access 
pipelines and/or power poles that are not located adjacent to the 
gravel roads. These vehicles typically operate near the road (152 m 
[500 ft]) and may operate for 24 hours a day during summer months. 
During winter months, temporary ice roads and pads are built to move 
heavy equipment to areas that may be inaccessible. Winter tundra travel 
distances and cumulative ice road lengths average about 120.7 and 12.1 
km (75 and 7.5 mi), respectively, and may occur at any hour of the day. 
An additional 0.8 ha (2 ac) of ice pads are constructed each winter.
    West Dock is the primary marine gateway to the greater Prudhoe Bay 
area with users including Industry vessels, cargo ships, oil spill 
responders, subsistence users, and to a lesser degree,

[[Page 42993]]

public and commercial vessels. Routine annual maintenance dredging of 
the seafloor around the WDC occurs to maintain navigational access to 
DH2 and DH3 and to insure continued intake of seawater to the existing 
STP. Approximately 15,291 cubic m (20,000 cubic yd) of material is 
anticipated to be dredged over 56.6 ha (140 ac); however, up to 172,024 
cubic m (225,000 cubic yd) of material is authorized to be removed in a 
single year. All dredged material is placed as fill on the WDC for 
beach replenishment and erosion protection. Some sediments are moved 
but remain on the seafloor as part of the screeding process. Much of 
the dredging work takes place during the open-water season between May 
and October and will be completed in less than 30 working days. Annual 
installation and floats, moorings, and buoys are installed at the 
beginning of the open-water season and are removed at the end of the 
open-water season. Up to three buoys may be installed to each side of 
the breach (up to six buoys total).
    During the 2021-2022 winter tundra travel period, an additional 8-
km (5-mi) ice road, 0.8-ha (2-ac) ice pad, up to 8-km (5-mi) pipeline, 
and pad space are expected to be constructed to support I-Pad expansion 
totaling 12.1 ha (30 ac) for the ice road and ice pad and 8.5 ha (21 
ac) for the pad space, pipeline, and VSM footprints. Other pad 
expansions include approximately 0.8 ha (2 ac) per year 2021-2026 at 
DS3-DS0 and P-Pad.
    Additionally, the construction of up to a 56.7-ha (140-ac) mine 
site is expected. Construction will occur on a need-based, phased 
approach over 40 years with no more than 24.3 ha (60 ac) of gravel 
developed by 2026. A 4.3-km (2.7-mi) long and 24.4-m (80-ft) wide 
gravel access road will also be built for a total impacted area of 10.5 
ha (26 ac) over 1 year.
Trans-Alaska Pipeline System (TAPS)
    TAPS is a 122-cm (48-in) diameter crude oil transportation pipeline 
system that extends 1,287 km (800 mi) from Pump Station 1 in Prudhoe 
Bay Oilfield to the Valdez Marine Terminal. The lands occupied by TAPS 
are State-owned, and the ROWs are leased through April 2034. Alyeska 
Pipeline Service Company operates the pipeline ROW. Approximately 37 km 
(23 mi) of pipeline are located within 40 km (25 mi) of the Beaufort 
Sea coastline. A 238-km (148-mi) natural gas line that extends from 
Pump Station 1 provides support for pipeline operations and facilities. 
The TAPS mainline pipe ROW includes a gravel work pad and drive lane 
that crosses the Dalton Highway approximately 29 km (18 mi) south of 
Pump Station 1.
    Travel primarily occurs along established rounds, four pipeline 
access roads, or along the pipeline ROW work pad. Ground-based 
surveillance on the TAPS ROW occurs once per week throughout the year. 
Equipment and supplies are transported via commercial carriers on the 
Dalton Highway. In the summer, travel is primarily restricted to the 
gravel work pad and access roads. There are occasional crossings of 
unvegetated gravel bars to repair remote flood control structures on 
the Sagavanirktok River. Transport of small-volume gravel material from 
the active river floodplain to the TAPS work pad may occur. Vehicles 
used during the summer include typical highway vehicles, maintenance 
equipment, and off-road trucks for gravel material transport. In the 
winter, travel occurs in similar areas compared to summer in addition 
to maintenance activities, such as subsurface pipeline excavations. 
Short (<0.4 km, <0.25 mi) temporary ice roads and ice pads are built to 
move heavy equipment when necessary. Vehicles used during the winter 
include off-road tracked vehicles so that snow plowing on the ROW is 
not required. The amount of traffic is generally not influenced by the 
time of year.
    The Deadhorse Airport is the primary hub used for personnel 
transport and airfreight to TAPS facilities in the northern pipeline 
area. Commercial and charter flights are used for personnel transport, 
and crew change-outs generally occur every 2 weeks. Other aviation 
activities include pipeline surveillance, oil spill exercise/training/
response, and seasonal hydrology observations. Aerial surveillance of 
the pipeline occurs once each week during daylight hours throughout the 
year. Approximately 50 hours per year are flown within 40 km (25 mi) of 
the Beaufort Sea coastline.
    No TAPS-related in-water activities occur in the Beaufort Sea. 
Instead, these activities will be limited to the Sagavanirktok River 
and its tributaries. In-water construction and dredging may take place 
occasionally, and they are generally associated with flood control 
structures and repairs to culverts, low water crossings, and eroded 
work pads. Gravel mining may also occur on dry unvegetated bars of the 
active floodplain or in established gravel pits. On river bars, up to a 
0.9-m (3-ft) deep layer of alluvial gravel is removed when the river is 
low, and this layer is allowed to naturally replenish. Additional 
construction of flood structures may be needed to address changes in 
the hydrology of the Sagavanirktok River and its tributaries during the 
2021-2026 period.
Western North Slope--Colville River and Greater Mooses Tooth Units
    The Western North Slope (WNS) consists of the CPAI's Alpine and 
Alpine satellite operations in the Colville River Unit (CRU) and the 
Greater Mooses Tooth Unit (GMTU). The Alpine reservoir covers 50,264 ha 
(124,204 ac), but the total developed area is approximately 153 ha (378 
ac), which contains 45 km (28 mi) of gravel roads, 51.5 km (32 mi) of 
pipelines, and 14 gravel pads. The CRU has a combined production pad/
drill site and four additional drill sites. The GMTU contains one 
producing drill site and a second drill site undergoing construction. 
Roads and pads are generally constructed during winter.
    There are no permanent roads connecting WNS to industrial hubs or 
other oilfields. Gravel roads connect four of the five CRU drill sites. 
An ice road is constructed each winter to connect to the fifth CRU 
drill site. Gravel roads also connect the GMTU drill sites to the CRU, 
and gravel roads connect the two GMTU drill sites to each other. Each 
drill site with gravel road access is visited at least twice during a 
24-hour period, depending on the weather. Drill site traffic levels 
increase during active drilling, maintenance, or other projects. 
Vehicles that use the gravel roads include light passenger trucks, 
heavy tractor-trailer trucks, heavy equipment, and very large drill 
rigs. The amount of traffic is generally not influenced by the time of 
year, but there may be increased amounts of traffic during the 
exploration season.
    In the winter, off-road vehicles are used to access equipment for 
maintenance and inspections. Temporary ice roads and ice pads are built 
to move heavy equipment for maintenance and construction activities. An 
ice road is constructed to connect WNS to the Kuparuk oilfield (KRU) to 
move supplies for the rest of the year. More than 1,500 truckloads of 
modules, pipeline, and equipment are moved to WNS over this ice road, 
which is approximately 105 km (65 mi) in length. As mentioned 
previously, an ice road is constructed each winter to connect one of 
the CRU drill sites to the other CRU facilities in order to facilitate 
maintenance, drilling, and operations at this drill site. WNS ice roads 
typically operate from mid-January until late-April.
    The Alpine Airstrip is a private runway that is used to transport 
personnel and cargo. An average of 60

[[Page 42994]]

to 80 personnel flights to/from the Alpine Airstrip occur each week. 
Within the CRU, the Alpine Airport transports personnel and supplies to 
and from the CRU drill site that is only connected by an ice road 
during the winter. There are approximately 700 cargo flights into 
Alpine each year. Cargo flight activity varies throughout the year with 
October through December being the busiest months. Aerial visual 
surveillance of the Alpine crude pipeline is conducted weekly for 
sections of the pipeline that are not accessible either by road or 
during winter months. These aerial surveillance inspections generally 
occur one to two times each week, and they average between two and four 
total flight hours each week. CPAI also uses aircraft to conduct 
environmental studies, including polar den detection surveys in the 
winter and caribou and bird surveys in the summer. These environmental 
surveys cover approximately 1,287 linear km (800 linear mi) over the 
CRU each year. In the summer from mid-May to mid-September, CPAI uses 
helicopters to transport personnel and equipment within the CRU 
(approximately 2,000 flights) and GMTU (approximately 650 flights).
    There are no offshore or coastal facilities in the CRU. However, 
there are multiple bridges in the CRU and GMTU that required pilings 
which were driven into stream/riverbeds during construction. In-water 
activities may occur during emergency and oil spill response training 
exercises. During the ice-covered periods, training exercises may 
involve using equipment to detect, contain, and recover oil on and 
under ice. During the open-water season, air boats, shallow-draft jet 
boats and possibly other vessels may be used in the Nigliq Channel, the 
Colville River Main Channel, and other channels and tributaries 
connected to the Colville River. Vessels may occasionally enter the 
nearshore Beaufort Sea to transit between channels and/or tributaries 
of the Colville River Delta.
    In the 2021-2026 period, two 4-ha (10-ac) multiseason ice pads 
would be located in the WNS in order to support the Willow Development 
construction in the NPR-A. Possible expansion activities for this 
period may include small pad expansions or new pads (<6.1 ha (15 ac)) 
to accommodate additional drilling and development of small pads and 
gravel roads to accommodate additional facilities and operational 
needs. Two gravel mine sources in the Ti[eng]miaqsiu[gdot]vik area have 
been permitted to supply gravel for the Willow Development. The new 
gravel source would be accessed seasonally by an ice road. Increases in 
the amount of traffic within WNS are expected from 2023 to 2026. The 
increase in traffic is due to the transport of freight, equipment, and 
support crew between the Willow Development, the Oliktok Dock, and the 
Kuparuk Airport. The planned Willow Development is projected to add 
several flights to/from the Alpine Airstrip from 2021 to 2026. It is 
estimated that the number of annual flights may increase by a range of 
49 to 122 flights. There are plans to replace passenger flights 
connecting Alpine and Kuparuk oilfields in 2021 with direct flights to 
these oilfields. This change would reduce the number of connector 
flights between these oilfields from 18 flights to 5 flights each week.

Planned Activities at New Oil and Gas Facilities for 2021-2026

    AOGA's Request includes several new oil and gas facilities being 
planned for leases obtained by Industry (see the section about Lease 
Sales) in which development and exploration activities would occur. The 
information discussed below was provided by AOGA and is the best 
available information at the time AOGA's Request was finalized.
Bear Tooth Unit (Willow)
    Located 45.1 km (28 mi) from Alpine, the Willow Development is 
currently owned and operated by ConocoPhillips Alaska, Inc. Willow is 
found in the Bear Tooth Unit (BTU) located within the northeastern area 
of the NPR-A. Discovered in 2016 after the drilling of the Ti[eng]miaq 
2 and 6 wells, Willow is estimated to contain 400-750 million barrels 
of oil and has the potential to produce over 100,000 barrels of oil per 
day. The Willow Project would require the development of several 
different types of infrastructure, including gravel roads, airstrips, 
ice roads, and ice pads, that would benefit seismic surveys, drilling, 
operations, production, pile-driving, dredging, and construction.
    ConocoPhillips plans to develop the hydrocarbon resources within 
the BTU during the 2021-2026 timeline under this ITR. The proposed 
development at Willow would consist of five drill sites along with 
associated infrastructure, including flowlines, a CPF, a personnel 
camp, an airstrip, a sales oil pipeline, and various roads across the 
area. Additionally, Willow would require the development of a new 
gravel mine site and would use sea lifts for large modules at Oliktok 
Dock requiring transportation over gravel and ice roads in the winter.
    Access to the Willow Development project area to Alpine, Kuparuk, 
or Deadhorse would be available by ground transportation along ice 
roads. Additionally, access to the Alpine Unit would occur by gravel 
road. The Development Plan requires 61.5 km (38.2 mi) of gravel road 
and seven bridges to connect the five drill sites to the Greater Mooses 
Tooth 2 (GMT2). The Willow Development would also require approximately 
59.7 km (37.1 mi) or 104 ha (257.2 ac) of gravel roads to the Willow 
Central Processing Facility (WCF), the WCF to the Greater Mooses Tooth 
2 (GMT2), to water sources, and to airstrip access roads. The gravel 
needed for any gravel-based development would be mined from a newly 
developed gravel mine site and then placed for the appropriate 
infrastructure during winter for the first 3 to 4 years of the 
construction.
    Gravel mining and placement would occur almost exclusively in the 
winter season. Prepacked snow and ice road construction will be 
developed to access the gravel mine site, the gravel road, and pad 
locations in December and January yearly from 2021 to 2024, and again 
in 2026. Ice roads would be available for use by February 1 annually. 
The Willow plan would require gravel for several facilities, including 
Bear Tooth 1 (BT1), Bear Tooth 2 (BT2), Bear Tooth 3 (BT3), Bear Tooth 
4 (BT4), roads, WCF, Willow Operations Center (WOC), and the airstrip. 
Additionally, an all-season gravel road would be present from the GMT2 
development and extend southwest towards the Willow Development area. 
This access road would end at BT3, located west from the WCF, WOC, and 
the airstrip. More gravel roads are planned to extend to the north, 
connecting BT1, BT2, and BT4. An infield road at BT3 would provide a 
water-source access road that would extend to the east to a freshwater 
reservoir access pad and water intake system developed by 
ConocoPhillips. Further east from the planned airstrip, an infield road 
is planned to extend north to BT1, continue north to BT2, and end at 
BT4. This road would intersect Judy (Iqalliqpik) Creek and Fish 
(Uvlutuuq) Creek at several points. Culvert locations would be 
identified and installed during the first construction season prior to 
breakup. Gravel pads would be developed before on-pad facilities are 
constructed. Gravel conditions and re-compaction would occur later in 
the year.
    The Willow area is expected to have year-round aircraft operations 
and access from the Alpine Unit, Kuparuk Unit, Deadhorse, Anchorage, 
Fairbanks, and several other locations. Aircraft would primarily be 
used for support activities and transporting workers,

[[Page 42995]]

materials, equipment, and waste from the Willow Development to 
Fairbanks, Anchorage, Kuparuk, and Deadhorse. To support these 
operations, a 1,890-m (6,200-ft)-long gravel airstrip would be 
developed and is expected to be located near the WOC. Aircraft flight 
paths would be directed to the north of Nuiqsut. The construction for 
the airstrip is expected to begin during the 2021 winter season and 
completed by the summer of 2022. Before its completion, ConocoPhillips 
would utilize the airstrip at the Colville Delta 1 at the Alpine CPF. 
After completion of the airstrip, helicopters would be used to support 
various projects within the Willow Development starting in 2023. An 
estimated 82 helicopter flights would occur annually during 2023-2026 
between April and August. After the development of planned gravel roads 
and during activities such as drilling and related operations, 
helicopters would be limited to support environmental monitoring and 
spill response support. ConocoPhillips estimates that 50 helicopter 
trips to and from Alpine would occur in 2021, and 25 helicopter trips 
would occur from Alpine in 2022.
    ConocoPhillips plans to develop and utilize ice roads to support 
gravel infrastructure and pipeline construction to access lakes and 
gravel sources and use separate ice roads for construction and general 
traffic due to safety considerations regarding traffic frequency and 
equipment size. The ice road used to travel to the Willow Development 
is estimated to be shorter in length than previously built ice roads at 
Kuparuk and Alpine, and ConocoPhillips expects the ice road use season 
at Willow to be approximately 90 days, from January 25 to April 25. In 
the winter ice road season (February through April), material resupply 
and waste would be transported to Kuparuk and to the rest of the North 
Slope gravel road system via the annual Alpine Resupply Ice Road. 
Additionally, during drilling and operations, there would be seasonal 
ground access from Willow to Deadhorse and Kuparuk from the annually 
constructed Alpine Resupply Ice Road and then to the Alpine and GMT 
gravel roads.
    Seasonal ice roads would be developed and used during construction 
at Willow's gravel mine, bridge crossings, horizontal directional 
drilling crossing, and other locations as needed. A 4-ha (10-ac) 
multiseason ice pad would be developed and used throughout 
construction. This ice pad would be constructed near the WOC from 2021 
to 2022 and rotated on an annual basis.
    Pipelines for the Willow Development would be installed during the 
winter season from ice roads. Following VSMs and horizontal support 
members (HSMs) assembly and installation; pipelines would be placed, 
welded, tested, and installed on pipe saddles on top of the HSMs. 
ConocoPhillips expects that the Colville River horizontal directional 
drilling pipeline crossing would be completed during the 2022 winter 
season. Pipeline installation would take approximately 1 to 3 years per 
pipeline, depending on several parameters such as pipeline length and 
location.
    In 2024 at BT1, a drill rig would be mobilized, and drilling would 
begin prior to the WCF and drill site facilities being completed. 
ConocoPhillips estimates about 18 to 24 months of ``pre-drilling'' 
activities to occur, allowing the WCF to be commissioned immediately 
after its construction. Wells would be drilled consecutively from BT1, 
BT3, and BT2; however, the timing and order is based upon drill rig 
availability and economic decisionmaking. A second drilling rig may be 
utilized during the drilling phase of the Willow Development as well. 
ConocoPhillips estimates that drilling would occur year-round through 
2030, with approximately 20 to 30 days of drilling per well.
    Post-drilling phase and WCF startup, standard production and 
operation activities would take place. ConocoPhillips estimates that 
production would begin in the fourth quarter of 2025 with well 
maintenance operations occurring intermittently throughout the 
oilfield's lifespan.
    ConocoPhillips plans to develop several bridges, installed via in-
water pile-driving at Judy Creek, Fish Creek, Judy Creek Kayyaaq, 
Willow Creek 2, and Willow Creek 4. Pilings would be located above the 
ordinary high-water level and consist of sheet pile abutments done in 
sets of four, positioned approximately 12.2 to 21.3 m (40 to 70 ft) 
apart. Crossings over Willow Creek 4a and Willow Creek 8 would be 
constructed as single-span bridges, approximately 15.2 to 18.3 m (50 to 
60 ft) apart using sheet pile abutments. Additionally, bridges would be 
constructed during the winter season from ice roads and pads. Screeding 
activities and marine traffic for the Willow project may also take 
place at the Oliktok Dock in the KRU.
Liberty Drilling and Production Island
    The Liberty reservoir is located in Federal waters in Foggy Island 
Bay about 13 km (8 mi) east of the Endicott Satellite Drilling Island 
(SDI). Hilcorp plans to build a gravel island situated over the 
reservoir with a full on-island processing facility (similar to 
Northstar). The Liberty pipeline includes an offshore segment that 
would be buried in the seafloor for approximately 9.7 km (6 mi), and an 
onshore, VSM-mounted segment extending from the shoreline approximately 
3.2 km (2 mi) to the Badami tie-in. Onshore infrastructure would 
include a gravel mine site, a 0.29-ha (0.71-ac) gravel pad at the 
Badami pipeline tie-in and a 6.1-ha (0.15-ac) gravel pad to allow for 
winter season ice road crossing. Environmental, archeological, and 
geotechnical work activities would take place to support the 
development and help inform decisionmaking. Development of the Liberty 
Island would include impact driving for conductor pipes/foundation 
pipes, vibratory drilling for conductor pipes, and vibratory and impact 
driving for sheet pile.
    Road vehicles would use the Alaska Highway System to transport 
material and equipment from supply points in Fairbanks, Anchorage, or 
outside of Alaska to the supply hub of Deadhorse. Additionally, North 
Slope gravel roads would be used for transport from Deadhorse to the 
Endicott SDI. Existing gravel roads within the Endicott field between 
the MPI and the SDI would also be used to support the project.
    During the winter seasons, workers would access the Liberty Island 
area from existing facilities via gravel roads and the ice road system. 
Construction vehicles would be staged at the construction sites, 
including the gravel mine. Access to the Liberty Drilling and 
Production Island (LDPI) by surface transportation is limited by 
periods when ice roads can be constructed and used. Additionally, 
surface transportation to the onshore pipeline can take place in winter 
on ice roads and can also occur in summer by approved tundra travel 
vehicles (e.g., Rolligons). The highest volume of traffic would occur 
during gravel hauls to create the LDPI. Gravel hauling to the island 
would require approximately 14 trucks working for 76 days (BOEM 2018). 
An estimated 21,400 surface vehicle trips would occur per season during 
island construction.
    In general, ice roads would be used in the winter seasons, marine 
vessels would be used in the summer seasons, helicopters would be used 
across both seasons, and hovercraft (if necessary) would be used during 
the shoulder season when ice roads and open water are not available. By 
spring breakup, all materials needed to support the ongoing 
construction would have been transported over the ice road system.

[[Page 42996]]

Additionally, personnel would access the island by helicopter (likely a 
Bell 212) or if necessary, via hovercraft. During the open-water 
season, continued use of helicopter and hovercraft would be utilized to 
transport personnel--however, crew boats may also be used.
    Construction materials and supplies would be mobilized to the site 
by barge from West Dock or Endicott. Larger barges and tugs can over-
winter in the Prudhoe Bay area and travel to the LDPI in the open-water 
season, generally being chartered on a seasonal basis or long-term 
contract. Vessels would include coastal and ocean-going barges and tugs 
to move large modules and equipment and smaller vessels to move 
personnel, supplies, tools, and smaller equipment. Barge traffic 
consisting of large ocean-going barges originating from Dutch Harbor is 
likely to consist of one-to-two vessels, approximately two-to-five 
times per year during construction, and only one trip every 5 years 
during operations. During the first 2 years following LDPI 
construction, hovercraft may make up to three trips per day from 
Endicott SDI to LDPI. After those 2 years, hovercraft may make up to 
two trips per day from Endicott SDI to LDPI (approximately 11.3 km [7 
mi]).
    Air operations are often limited by weather conditions and 
visibility. In general, air access would be used for movement of 
personnel and foodstuffs and for movement of supplies or equipment when 
necessary. Fixed-wing aircraft may be used on an as-needed basis for 
purposes of spill response (spill delineation) and aerial 
reconnaissance of anomalous conditions or unless otherwise required by 
regulatory authority. Helicopter use is planned for re-supply during 
the broken-ice seasons and access for maintenance and inspection of the 
onshore pipeline system. In the period between completion of hydro-
testing and facilities startup, an estimated one-to-two helicopter 
flights per week are also expected for several weeks for personnel 
access and to transport equipment to the tie-in area. Typically, air 
traffic routing is as direct as possible from departure locations such 
as the SDI, West Dock, or Deadhorse to the LDPI, with routes and 
altitude adjusted to accommodate weather, other air traffic, and 
subsistence activities. Hilcorp would minimize potential disturbance to 
mammals from helicopter flights to support LDPI construction by 
limiting the flights to an established corridor from the LPDI to the 
mainland and except during landing and takeoff, and these flights would 
maintain a minimum altitude of 457 m (1,500 ft) above ground level 
(AGL) unless inclement weather requires deviation. Equipment located at 
the pipeline tie-in location and the pipeline shore landing would be 
accessed by helicopter or approved tundra travel vehicles to minimize 
impacts to the tundra.
    Additionally, Hilcorp may use unmanned aerial surveys (UASs) during 
pile driving, pipe driving, and slope shaping and armament activities 
during the open-water season in Year 2 of construction and subsequently 
during decommissioning to monitor for whales or seals that may occur in 
incidental Level B harassment zones as described in the 2019 LOA issued 
by the National Marine Fisheries Service (NMFS 2020). Recent 
developments in the technical capacity and civilian use of UASs 
(defined as vehicles flying without a human pilot on board) have led to 
some investigations into potential use of these systems for monitoring 
and conducting aerial surveys of marine mammals (Koski et al. 2009; 
Hodgson et al. 2013). UASs, operating under autopilot and mounted with 
Global Positioning System (GPS) and imaging systems, have been used and 
evaluated in the Arctic (Koski et al. 2009) and have potential to 
replace traditional manned aerial surveys and provide an improved 
method for monitoring marine mammal populations. Hilcorp plans to seek 
a waiver, if necessary, from the Federal Aviation Administration (FAA) 
to operate the UAS above 122 m (400 ft) and beyond the line of sight of 
the pilot. Ground control for the UAS would be located at Liberty 
Island, Endicott, or another shore-based facility close to Liberty 
(NMFS 2020).
    After construction, aircraft, land vehicle, and marine traffic may 
be at similar levels as those described for Northstar Island, although 
specific details beyond those presented here are not presently known.
    Ice roads would be used for onshore and offshore access, installing 
the pipeline, hauling gravel used to construct the island, moving 
equipment on/off the island, and personnel and supply transit. Ice road 
construction can typically be initiated in mid- to late-December and 
can be maintained until mid-May, weather depending. Ice road #1 would 
extend approximately 11.3 km (7 mi) over shorefast sea ice from the 
Endicott SDI to the LDPI (the SDI to LDPI ice road). It would be 
approximately 37 m wide (120 ft) with a driving lane of approximately 
12 m (40 ft) and cover approximately 64.8 ha (160 ac) of sea ice. Ice 
road #2 (approximately 11.3 km [7 mi]) would connect the LDPI to the 
proposed Kadleroshilik River gravel mine site and then would continue 
to the juncture with the Badami ice road (which is ice road #4). It 
would be approximately 15 m (50 ft) wide. Ice road #3 (approximately 
9.6 km [6 mi], termed the ``Midpoint Access Road'') would intersect the 
SDI to LDPI ice road and the ice road between the LDPI and the mine 
site. It would be approximately 12 m (40 ft) wide. Ice road #4 
(approximately 19.3 km [12 mi]), located completely onshore, would 
parallel the Badami pipeline and connect the mine site with the 
Endicott road.
    All four ice roads would be constructed for the first 3 years to 
support pipeline installation and transportation from existing North 
Slope roads to the proposed gravel mine site, and from the mine site to 
the proposed LDPI location in the Beaufort Sea. After Year 3, only ice 
road #1 would be constructed to allow additional materials and 
equipment to be mobilized to support LDPI, pipeline, and facility 
construction activities as all island construction and pipeline 
installation should be complete by Year 3. In addition to the ice 
roads, three ice pads are proposed to support construction activities 
(Year 2 and Year 3). These would be used to support LDPI, pipeline 
(including pipe stringing and two stockpile/disposal areas), and 
facilities construction. A fourth staging area ice pad (approximately 
107 by 213 m (350 by 700 ft) would be built on the sea ice on the west 
side of the LDPI during production well drilling operations.
    Other on-ice activities occurring prior to March 1 may include 
spill training exercises, pipeline surveys, snow clearing, and work 
conducted by other snow vehicles such as a Pisten Bully, snow machine, 
or Rolligon. Prior to March 1, these activities would occur outside of 
the delineated ice road/trail and shoulder areas.
    The LDPI would include a self-contained offshore drilling and 
production facility located on an artificial gravel island with a 
subsea pipeline to shore. The LDPI would be located approximately 8 km 
(5 mi) offshore in Foggy Island Bay and 11.7 km (7.3 mi) southeast of 
the existing SDI on the Endicott causeway. The LDPI would be 
constructed of reinforced gravel in 5.8 m (19 ft) of water and have a 
working surface of approximately 3.8 ha (9.3 ac). A steel sheet pile 
wall would surround the island to stabilize the placed gravel, and the 
island would include a slope protection bench, dock and ice road 
access, and a seawater intake area.

[[Page 42997]]

    Hilcorp would begin constructing the LDPI during the winter 
immediately following construction of the ice road from the mine site 
to the island location. Sections of sea ice at the island's location 
would be cut using a ditchwitch and removed. A backhoe and support 
trucks using the ice road would move ice away. Once the ice is removed, 
gravel would be poured through the water column to the sea floor, 
building the island structure from the bottom up. A conical pile of 
gravel (hauled in from trucks from the mine site using the ice road) 
would form on the sea floor until it reaches the surface of the ice. 
Gravel hauling over the ice road to the LDPI construction site is 
estimated to continue for 50 to 70 days and conclude mid-April or 
earlier depending on road conditions. The construction would continue 
with a sequence of removing additional ice and pouring gravel until the 
surface size is achieved.
    Following gravel placement, slope armoring and protection 
installation would occur. Using island-based equipment (e.g., backhoe, 
bucket-dredge) and divers, Hilcorp would create a slope protection 
profile consisting of an 18.3-m (60-ft)-wide bench covered with a 
linked concrete mat that extends from a sheet pile wall surrounding the 
island to slightly above medium lower low water. The linked concrete 
mat requires a high-strength, yet highly permeable, woven polyester 
fabric under layer to contain the gravel island fill. The filter fabric 
panels would be overlapped and tied together side-by-side (requiring 
diving operations) to prevent the panels from separating and exposing 
the underlying gravel fill. Because the fabric is overlapped and tied 
together, no slope protection debris would enter the water column 
should it be damaged. Above the fabric under layer, a robust geo-grid 
would be placed as an abrasion guard to prevent damage to the fabric by 
the linked mat armor. The concrete mat system would continue at a 3:1 
slope another 26.4 m (86.5 ft) into the water, terminating at a depth 
of 5.8 m (19 ft). In total, from the sheet pile wall, the bench and 
concrete mat would extend 44.7 m (146.5 ft). Island slope protection is 
required to ensure the integrity of the gravel island by protecting it 
from the erosive forces of waves, ice ride-up, and currents. A detailed 
inspection of the island slope protection system would be conducted 
annually during the open-water season to document changes in the 
condition of this system that have occurred since the previous year's 
inspection. Any damaged material would be removed. Above-water 
activities would consist of a visual inspection of the dock and sheet 
pile enclosure that would document the condition of the island bench 
and ramps. The below-water slopes would be inspected by divers or, if 
water clarity allows, remotely by underwater cameras contracted 
separately by Hilcorp. The results of the below-water inspection would 
be recorded for repair if needed. No vessels would be required. Multi-
beam bathymetry and side-scan sonar imagery of the below-water slopes 
and adjacent sea bottom would be acquired using a bathymetry vessel. 
The sidescan sonar would operate at a frequency between 200 and 400 
kHz. The single-beam echosounder would operate at a frequency of about 
210 kHz.
    Once the slope protection is in place, Hilcorp would install the 
sheet pile wall around the perimeter of the island using vibratory and, 
if necessary, impact hammers. Sheet pile driving is anticipated to be 
conducted between March and August, during approximately 4 months of 
the ice-covered season and, if necessary, approximately 15 days during 
the open-water season. Sheet pile driving methods and techniques are 
expected to be similar to the installation of sheet piles at Northstar 
during which all pile driving was completed during the ice-covered 
season. Therefore, Hilcorp anticipates most or all sheet pile would be 
installed during ice-covered conditions. Hilcorp anticipates driving up 
to 20 piles per day to a depth of 7.62 m (25 ft). A vibratory hammer 
would be used first, followed by an impact hammer to ``proof'' the 
pile. Hilcorp anticipates each pile needing 100 hammer strikes over 
approximately 2 minutes (100 strikes) of impact driving to obtain the 
final desired depth for each sheet pile. To finish installing up to 20 
piles per day, the impact hammer would be used a maximum of 40 minutes 
per day with an anticipated duration of 20 minutes per day.
    For vibratory driving, pile penetration speed can vary depending on 
ground conditions, but a minimum sheet pile penetration speed is 0.5 m 
(20 in) per minute to avoid damage to the pile or hammer (NASSPA 2005). 
For this project, the anticipated duration is based on a preferred 
penetration speed greater than 1 m (40 in) per minute, resulting in 7.5 
minutes to drive each pile. Given the high storm surge and larger waves 
that are expected to arrive at the LDPI site from the west and 
northwest, the wall would be higher on the west side than on the east 
side. At the top of the sheet-pile wall, overhanging steel ``parapet'' 
would be installed to prevent wave passage over the wall.
    Within the interior of the island, 16 steel conductor pipes would 
be driven to a depth of 49 m (160 ft) to provide the initial stable 
structural foundation for each oil well. They would be set in a well 
row in the middle of the island. Depending on the substrate, the 
conductor pipes would be driven by impact or vibratory methods or both. 
During the construction of the nearby Northstar Island (located in 
deeper water), it took 5 to 8.5 hours to drive one conductor pipe 
(Blackwell et al. 2004). For the Liberty LDPI, based on the 20 percent 
impact hammer usage factor (USDOT 2006.), it is expected that two 
cumulative hours of impact pipe driving (4,400 to 3,600 strikes) would 
occur over a 10.5 non-consecutive hour day. Conductor pipe driving is 
anticipated to be conducted between March and August and take 16 days 
total, installing one pipe per day. In addition, approximately 700 to 
1,000 foundation piles may also be installed within the interior of the 
island should engineering determine they are necessary for island 
support.
    The LDPI layout includes areas for staging, drilling, production, 
utilities, a camp, a relief well, a helicopter landing pad, and two 
docks to accommodate barges, a hovercraft, and small crew boats. It 
would also have ramps for ice road and amphibious vehicle access. An 
STP would also be located at the facility to treat seawater and then 
commingle it with produced water to be injected into the Liberty 
Reservoir to maintain reservoir pressure. Treated seawater would be 
used to create potable water and utility water for the facility. A 
membrane bioreactor would treat sanitary wastewater, and remaining 
sewage solids would be incinerated on the island or stored in enclosed 
tanks prior to shipment to Deadhorse for treatment.
    All modules, buildings, and material for onsite construction would 
be trucked to the North Slope via the Dalton Highway and staged at West 
Dock, Endicott SDI, or in Deadhorse. Another option is to use ocean-
going barges from Dutch Harbor to transport materials or modules to the 
island during the open-water season.
    Depending on the season, equipment and material would be 
transported via coastal barges in open water, or ice roads from SDI in 
the winter. The first modules would be delivered in the third quarter 
of Year 2 to support the installation of living, drilling, and 
production facilities. Remaining process modules would be delivered to

[[Page 42998]]

correspond with first oil and the ramp-up in drilling capacity.
    Onsite facility installation would commence in August of Year 2 and 
be completed by the end of Year 4 (May) to accommodate the overall 
construction and production ramp-up schedule. Some facilities that are 
required early would be barged in the third quarter of Year 2 and would 
be installed and operational by the end of the fourth quarter of Year 
2. Other modules would be delivered as soon as the ice road from SDI is 
in place. The drilling unit and associated equipment would be 
transferred by barge through Dutch Harbor or from West Dock to the LDPI 
during the open-water season in Year 2 using a seagoing barge and ocean 
class tug. The seagoing barge is ~30.5 m (100 ft) wide and ~122 m (400 
ft) long, and the tug is ~30.5 m (100 ft) long. Although the exact 
vessels to be used are unknown, Crowley lists Ocean class tugs at 
<1,600 gross registered tonnage. The weight of the seagoing barge is 
not known at this time.
    Hilcorp would install a pipe-in-pipe subsea pipeline consisting of 
a 30.5-cm (12-in)-diameter inner pipe and a 40.6-cm (16-in)-diameter 
outer pipe to transport oil from the LDPI to the existing Badami 
pipeline. Pipeline construction is planned for the winter after the 
island is constructed. A schematic of the pipeline can be found in 
Figure 2-3 of BOEM's Final EIS available at https://www.boem.gov/Hilcorp-Liberty/. The pipeline would extend from the LDPI, across Foggy 
Island Bay, and terminate onshore at the existing Badami Pipeline tie-
in location. For the marine segment, construction would progress from 
shallower water to deeper water with multiple construction spreads.
    To install the pipeline, a trench would be excavated using ice-
road-based long-reach excavators with pontoon tracks. The pipeline 
bundle would be lowered into the trench using side booms to control its 
vertical and horizontal position, and the trench would be backfilled by 
excavators using excavated trench spoils and select backfill. Hilcorp 
intends to place all material back in the trench slot. All work would 
be done from ice roads using conventional excavation and dirt-moving 
construction equipment. The target trench depth is 2.7 to 3.4 m (9 to 
11 ft) with a proposed maximum depth of cover of approximately 2.1 m (7 
ft). The pipeline would be approximately 9 km (5.6 mi) long.
    At the pipeline landfall (where the pipeline transitions from 
onshore to offshore), Hilcorp would construct an approximately 0.6-ha 
(1.4-ac) trench to protect against coastal erosion and ice ride-up 
associated with onshore sea ice movement and to accommodate the 
installation of thermosiphons (heat pipes that circulate fluid based on 
natural convection to maintain or cool ambient ground temperature) 
along the pipeline. The onshore pipeline would cross the tundra for 
almost 2.4 km (1.5 mi) until it intersects the existing Badami pipeline 
system. The single wall 30.5-cm (12-in) pipeline would rest on 150 to 
170 VSMs, spaced approximately 15 m (50 ft) apart to provide the 
pipeline a minimum 2.1-m (7-ft) clearance above the tundra. Hydro-
testing (pressure testing using sea water) of the entire pipeline would 
be required to complete pipeline commissioning.
    The final drill rig has yet to be chosen but has been narrowed to 2 
options and would accommodate drilling of 16 wells. The first option is 
the use of an existing platform-style drilling unit that Hilcorp owns 
and operates in the Cook Inlet. Designated as Rig 428, the rig has been 
used recently and is well suited in terms of depth and horsepower 
rating to drill the wells at Liberty. A second option that is being 
investigated is a new build drilling unit that would be built not only 
to drill Liberty development wells but would be more portable and more 
adaptable to other applications on the North Slope. Regardless of drill 
rig type, the well row arrangement on the island is designed to 
accommodate up to 16 wells. While Hilcorp is proposing a 16-well 
design, only 10 wells would be drilled. The six additional well slots 
would be available as backups or for potential in-fill drilling if 
needed during the project life.
    Drilling would be done using a conventional rotary drilling rig, 
initially powered by diesel, and eventually converted to fuel gas 
produced from the third well. Gas from the third well would also 
replace diesel fuel for the grind-and-inject facility and production 
facilities. A location on the LDPI is designated for drilling a relief 
well, if needed.
    Process facilities on the island would separate crude oil from 
produced water and gas. Gas and water would be injected into the 
reservoir to provide pressure support and increase recovery from the 
field. A single-phase subsea pipe-in-pipe pipeline would transport 
sales-quality crude from the LDPI to shore, where an aboveground 
pipeline would transport crude to the existing Badami pipeline. From 
there, crude would be transported to the Endicott Sales Oil Pipeline, 
which ties into Pump Station 1 of the TAPS for eventual delivery to a 
refinery.
North Slope Gas Development
    The AOGA Request discusses two projects currently submitted for 
approval and permitting that would transport natural gas from the North 
Slope via pipeline. Only a small fraction of this project would fall 
within the 40-km (25-mi) inland jurisdiction area of this ITR. The two 
projects are the Alaska Liquified Natural Gas Project (Alaska LNG) and 
the Alaska Stand Alone Pipeline (ASAP). Both of these projects are 
discussed below and their effects analyzed in this ITR, but only one 
project could be constructed during the 2021-2026 period.
Alaska Liquefied Natural Gas Project (Alaska LNG)
    The Alaska LNG project has been proposed by the Alaska Gasline 
Development Corporation (AGDC) to serve as a single integrated project 
with several facilities designed to liquefy natural gas. The fields of 
interest are the Point Thomson Unit (PTU) and PBU production fields. 
The Alaska LNG project would consist of a Gas Treatment Plant (GTP); a 
Point Thomson Transmission Line (PTTL) to connect the GTP to the PTU 
gas production facility; a Prudhoe Bay Transmission Line (PBTL) to 
connect the GTP to the PBU gas production facility; a liquefaction 
facility in southcentral Alaska; and a 1,297-km (807-mi)-long, 107-cm 
(42-in)-diameter pipeline (called the Mainline) that would connect the 
GTP to the liquefaction facility. Only the GTP, PTTL, PBTL, a portion 
of the Mainline, and related ancillary facilities would be located 
within the geographic scope of AOGA's Request. Related components would 
require the construction of ice roads, ice pads, gravel roads, gravel 
pads, camps, laydown areas, and infrastructure to support barge and 
module offloading.
    Barges would be used to transport GTP modules at West Dock at 
Prudhoe Bay several times annually, with GTP modules being offloaded 
and transported by land to the proposed GTP facility in the PBU. 
However, deliveries would require deep draft tug and barges to a newly 
constructed berthing site at the northeast end of West Dock. 
Additionally, some barges would continue to deliver small modules and 
supplies to Point Thomson. Related activities include screeding, 
shallow draft tug use, sea ice cutting, gravel placement, sea ice road 
and sea ice pad development, vibratory and impact pile driving, and the 
use of an offshore barge staging area.

[[Page 42999]]

    A temporary bridge (developed from ballasted barges) would be 
developed to assist in module transportation. Barges would be ballasted 
when the area is ice-free and then removed and overwintered at West 
Dock before the sea freezes over. A staging area would then be used to 
prepare modules for transportation, maintenance, and gravel road 
development. Installation of ramps and fortification would utilize 
vibratory and impact pile driving. Seabed preparations and level 
surface preparations (i.e., ice cutting, ice road development, gravel 
placement, screeding) would take place as needed. Breasting/mooring 
dolphins would be installed at the breach point via pile driving to 
anchor and stabilize the ballasted barges.
    A gravel pad would be developed to assist construction of the GTP, 
adjacent camps, and other relevant facilities where work crews utilize 
heavy equipment and machinery to assemble, install, and connect the GTP 
modules. To assist, gravel mining would use digging and blasting, and 
gravel would be placed to create pads and develop or improve ice and 
gravel roads.
    Several types of development and construction would be required at 
different stages of the project. The construction of the Mainline would 
require the use of ice pads, ice roads, gravel roads, chain trenchers, 
crane booms, backhoes, and other heavy equipment. The installation of 
the PTTL and PBTL would require ice roads, ice pads, gravel roads, 
crane booms, mobile drills or augers, lifts, and other heavy equipment. 
After installation, crews would work on land and streambank 
restoration, revegetation, hydrostatic testing, pipeline security, and 
monitoring efforts. The development of the ancillary facility would 
require the construction of ice roads, ice pads, as well as minimal 
transportation and gravel placement.
Alaska Stand Alone Pipeline (ASAP)
    The ASAP is the alternative project option that AGDC could utilize, 
allowing North Slope natural gas to be supplied to Alaskan communities. 
ASAP would require several components, including a Gas Conditioning 
Facility (GCF) at Prudhoe Bay; a 1,180-km (733-mi)-long, 0.9-m (36-in)-
diameter pipeline that would connect the GCF to a tie-in found in 
southcentral Alaska (called the Mainline); and a 48-km (30-m), 0.3-m 
(12-in)-diameter lateral pipeline connecting the Mainline pipeline to 
Fairbanks (referred to as the Fairbanks Lateral). Similar to the Alaska 
LNG pipeline, only parts of this project would fall within the 
geographic scope of this ITR. These relevant project components are the 
GCF, a portion of the ASAP Mainline, and related ancillary facilities. 
Construction would include the installation of supporting facilities 
and infrastructure, ice road and pad development, gravel road and pad 
development, camp establishment, laydown area establishment, and 
additional infrastructure to support barge and module offloading.
    Barges would be used to transport the GCF modules to West Dock in 
Prudhoe Bay and would be offloaded and transported by ground to the 
proposed facility site within the PBU. Module and supply deliveries 
would utilize deep draft tugs and barges to access an existing berthing 
location on the northeast side of West Dock called DH3. Maintenance on 
DH3 would be required to accommodate the delivery of larger loads and 
would consist of infrastructure reinforcement and elevation increases 
on one of the berths. In the winter, a navigational channel and turn 
basin would be dredged to a depth of 2.7 m (9 ft). Dredged material 
would be disposed of on ground-fast ice found in 0.6-1.2 m (2-4 ft) 
deep water in Prudhoe Bay. An offshore staging area would be developed 
approximately 4.8-8 km (3-5 mi) from West Dock to allow deep draft tugs 
and barges to stage before further transportation to DH3 and subsequent 
offload by shallow draft tugs. Other activities include seabed 
screeding, gravel placement, development of a sea ice road and pads, 
and pile driving (vibratory and impact) to install infrastructure at 
West Dock.
    A temporary bridge (composed of ballasted barges and associated 
infrastructure) paralleling an existing weight-limited bridge would be 
developed to assist in transporting large modules off West Dock. Barges 
would be ballasted when the area is ice-free and then removed and 
overwintered at West Dock before the sea freezes over. A staging area 
would be used to prepare modules for transportation, maintenance, and 
gravel road development. The bridge construction would require ramp 
installation, fortification through impact, and vibratory pile driving. 
Support activities (development of ice roads and pads, gravel roads and 
pads, ice cutting, seabed screeding) would also take place. Breasting/
mooring dolphins would be installed at the breach point via pile 
driving to anchor and stabilize the ballasted barges.
    A gravel facility pad would be formed to assist in the construction 
of the GCF. Access roads would then be developed to allow crews and 
heavy equipment to install and connect various GCF modules. Gravel 
would be obtained through digging, blasting, transportation, gravel pad 
placement, and improvements to other ice and gravel roads.
    The construction of the Mainline pipeline would require the 
construction of ice pads, ice roads, and gravel roads along with the 
use of chain trenchers, crane booms, backhoes, and other heavy 
equipment. Block valves would be installed above ground along the 
length of the Mainline. After installation, crews would work on land 
and streambank restoration, revegetation, hydrostatic testing, pipeline 
security, and monitoring efforts.
Pikka Unit
    The Pikka Development (formally known as the Nanshuk Project) is 
located approximately 83.7 km (52 mi) west of Deadhorse and 11.3 km (7 
mi) northeast of Nuiqsut. Oil Search Alaska operates leases held 
jointly between the State of Alaska and ASRC located southeast of the 
East Channel of the Colville River. Pikka is located further southwest 
from the existing Oooguruk Development Project, west of the existing 
KRU, and east of Alpine and Alpine's Satellite Development Projects. 
Most of the infrastructure is located over 8 km (5 mi) from the coast 
within the Pikka Unit; however, Oil Search Alaska expects some smaller 
projects and activities to occur outside the unit to the south, east, 
and at Oliktok Point.
    The Pikka Project would include a total of 3 drill-sites for 
approximately 150 (production, injectors, underground injection) wells, 
as well as the Nanshuk Processing Facility (NPF), the Nanushuk 
Operations Pad, a tie-in pad (TIP), various camps, warehouses, 
facilities on pads, infield pipelines, pipelines for import and export 
activities, various roads (ice, infield, access), a boat ramp, and a 
portable water system. Additionally, there are plans to expand the 
Oliktok Dock and to install an STP adjacent to the already existing 
infrastructure. A make-up water pipeline would also be installed from 
the STP to the TIP. Oil Search Alaska also plans to perform minor 
upgrades and maintenance, as necessary, to the existing road systems to 
facilitate transportation of sealift modules from Oliktok Point to the 
Pikka Unit.
    Oil Search Alaska plans to develop a pad to station the NPF and all 
relevant equipment and operations (i.e., phase separation, heating and 
cooling, pumping, gas treatment and compression for gas injections, 
water treatment for injection). All oil procured, processed, and 
designated for

[[Page 43000]]

sale would travel from the NPF to the TIP near Kuparuk's CPF 2 via the 
Pikka Project pipeline that would tie in to the Kuparuk Sales Pipeline 
and would then be transported to TAPS. Construction of the pad would 
allow for additional space that could be repurposed for drilling or for 
operational use during the development of the Pikka Project. This pad 
would contain other facilities required for project operation and 
development, including: Metering and pigging facilities; power 
generation facilities; a truck fill station; construction material 
staging areas; equipment staging areas; a tank farm (contains diesel, 
refined fuel, crude oil, injection water, production chemicals, glycol, 
and methanol storage tanks); and a central control room. All major 
components required for the development of the NPF would be constructed 
off-site and brought in via truck or barge during the summer season. 
Barges would deliver and offload necessary modules at Oliktok Dock, 
which would travel to the NPF site during summer months. Seabed 
screeding would occur at Oliktok Point to maintain water depth for 
necessary barges.
    Pikka would use gravel roads to the Unit, which would allow year-
round access from the Dalton Highway. All gravel needed for project 
activities (approximately 112 ha [276 ac]) would be sourced from 
several existing gravel mine sites. A majority of gravel acquisition 
and laying would occur during the winter season and then be compacted 
in the summer. All equipment and supplies necessary would be brought in 
on existing roads from Anchorage or Fairbanks to Deadhorse. Supplies 
and equipment would then be forwarded to the Pikka Unit; no aerial 
transportation for supplies is expected. Regular traffic is expected 
once construction of the roads is completed; Oil Search Alaska expects 
arterial routes between the processing facilities and camps to 
experience the heaviest use of traffic. Drill-site access roads are 
expected to experience the least amount of traffic; however, drill-site 
traffic is expected to increase temporarily during periods of active 
drilling, maintenance, or other relevant aspects of the project. 
Standard vehicles would include light passenger trucks, heavy tractor-
trailer trucks, heavy equipment, and oil rigs.
    Several types of aircraft operations are expected at the Pikka Unit 
throughout the 2021-2026 period. Personnel would be transported to 
Pikka via commercial flights from Deadhorse Airport and by ground-based 
vehicle transport. Currently, there is no plan to develop an airstrip 
at Pikka. Personnel flights are expected to be infrequent to and from 
the Pikka Unit; however, Oil Search Alaska expects that some transport 
directly to the Unit may be required. Several environmental studies 
performed via aircraft are expected during the ITR period. Some of 
these include AIR surveys, cultural resources, stick-picking, and 
hydrology studies. AIR surveys in support of the Pikka Unit would occur 
annually to locate polar bear dens.
    Summer travel would utilize vehicles such as Rolligons and Tuckers 
to assess pipelines not found adjacent to the gravel roads. During 24-
hour sunlight periods, these vehicles would operate across all hours. 
Stick-picking and thermistor retrieval would also occur in the summer. 
In the winter, ice roads would be constructed across the Unit. These 
ice roads would be developed to haul gravel from existing mine sites to 
haul gravel for road and pad construction. Ice roads would also be 
constructed to support the installation of VSM and pipelines. Off-road 
winter vehicles would be used when the tundra is frozen and covered 
with snow to provide maintenance and access for inspection. Temporary 
ice roads and ice pads would be built to allow for the movement and 
staging of heavy equipment, maintenance, and construction. Oil Search 
Alaska would perform regular winter travel to support operations across 
the Pikka Unit.
    Oil Search Alaska plans to install a bridge over the Kachemach 
River (more than 8 km [5 mi] from the coast) and install the STP at 
Oliktok Point. Both projects would require in-water pile driving, which 
is expected to take place during the winter seasons. In-water pile 
driving (in the winter), placement of gravel fill (open-water period), 
and installation of the STP barge outfall structure (open-water period) 
would take place at Oliktok Point. Dredging and screeding activities 
would prepare the site for STP and module delivery via barge. Annual 
maintenance screeding and dredging (expected twice during the Request 
period) may be needed to maintain the site. Dredging spoils would be 
transported away, and all work would occur during the open-water season 
between May and October. Screeding activities are expected to take 
place annually over the course of a 2-week period, depending on 
stability and safety needs.
Gas Hydrate Exploration and Research
    The U.S. Geological Survey (USGS) estimates that the North Slope 
contains over 54 trillion cubic feet of recoverable gas assets 
(Collette et al. 2019). Over the last 5 years, Industry has 
demonstrated a growing interest in the potential to explore and extract 
these reserves. Federal funds from the Department of Energy have been 
provided in the past to support programs on domestic gas hydrate 
exploration, research, and development. Furthermore, the State of 
Alaska provides support for gas hydrate research and development 
through the development of the Eileen hydrate trend deferred area near 
Milne Point, with specific leases being offered for gas hydrate 
research and exploration.
    As of 2021, a few gas hydrate exploration and test wells have been 
drilled within the Beaufort Sea region. Due to the support the gas 
hydrate industry has received, AOGA expects continued interest to grow 
over the years. As such, AOGA expects that a relatively low but 
increasing amount of gas hydrate exploration and research is expected 
throughout the 2021-2026 period.
Environmental Studies
    Per AOGA's Request, Industry would continue to engage in various 
environmental studies throughout the life of the ITR. Such activities 
include: Geological and geotechnical surveys (i.e., seismic surveys); 
surveys on geomorphology (soils, ice content, permafrost), archeology 
and cultural resources; vegetation mapping; analysis of fish, avian, 
and mammal species and their habitats; acoustic monitoring; hydrology 
studies; and various other freshwater, marine, and terrestrial studies 
of the coastal and offshore regions within the Arctic. These studies 
typically include various stakeholders, including consultants and 
consulting companies; other industries; government; academia 
(university-level); nonprofits and nongovernmental organizations; and 
local community parties. However, AOGA's 2021-2026 ITR Request seeks 
coverage only for environmental studies directly related to Industry 
activities (e.g., monitoring studies in response to regulatory 
requirements). No third-party studies will be covered except by those 
mentioned in this ITR and the AOGA Request.
    During the 2021-2026 lifespan of the ITR, Industry would continue 
studies that are conducted for general monitoring purposes for 
regulatory and/or permit requirements and for expected or planned 
exploration and development activities within the Beaufort Sea region. 
Environmental studies are anticipated to occur during the summer season 
as to avoid overlap with any denning polar bears. Activities

[[Page 43001]]

may utilize vessels, fixed-wing aircrafts, or helicopters to access 
research sites.
Mitigation Measures
    AOGA has included in their Request a number of measures to mitigate 
the effects of the proposed activities on Pacific walruses and polar 
bears. Many of these measures have been historically used by oil and 
gas entities throughout the North Slope of Alaska and have been 
developed as a part of past coordination with the Service. Measures 
include: Development and adherence to polar bear and Pacific walrus 
interaction plans; design of facilities to reduce the possibility of 
polar bears reaching attractants; avoidance of operating equipment near 
potential den locations; flying aircraft at a minimum altitude and 
distance from polar bears and hauled out Pacific walruses; employing 
trained protected species observers; and reporting all polar bear or 
Pacific walrus encounters to the Service. Additional descriptions of 
these measures can be found in the AOGA Request for an ITR at: 
www.regulations.gov in Docket No. FWS-R7-ES-2021-0037.
Maternal Polar Bear Den Survey Flights
    Per AOGA's Request, Industry will also conduct aerial infrared 
(AIR) surveys to locate maternal polar bear dens in order to mitigate 
potential impacts to mothers and cubs during the lifetime of this ITR. 
AIR surveys are used to detect body heat emitted by polar bears, which, 
in turn, is used to determine potential denning polar bears. AIR 
surveys are performed in winter months (December or January) before 
winter activities commence. AIR imagery is analyzed in real-time during 
the flight and then reviewed post-flight with the Service to identify 
any suspected maternal den locations, ensure appropriate coverage, and 
check the quality of the images and recordings. Some sites may need to 
be resurveyed if a suspected hotspot (heat signature detectable in a 
snowdrift) is observed. These followup surveys of hotspots are 
conducted in varying weather conditions or using an electro-optical 
camera during daylight hours. On-the-ground reconnaissance or the use 
of scent-training dogs may also be used to recheck the suspected den.
    Surveys utilize AIR cameras on fixed-wing aircrafts with flights 
typically flown between 245-457 meters (800-1,500 feet) above ground 
level at a speed of <185 km/h (<115 mph). Surveys typically occur twice 
a day (weather permitting) during periods of darkness (civil twilight) 
across the North Slope for less than 4.5 hours per survey. Surveys are 
highly dependent on the weather as it can affect the image quality of 
the AIR video and the safety of the participants. These surveys do not 
follow a typical transect configuration; instead they are concentrated 
on areas that would be suitable for polar bear denning activity such as 
drainages, banks, bluffs, or other areas of topographic relief around 
sites where Industry has winter activities, tundra travel, or ice road 
construction planned or anticipated. As part of AOGA's Request and as 
described in the mitigation measures included in this ITR, all denning 
habitat within 1 mile of the ice-season industrial footprint will be 
surveyed twice each year. In years where seismic surveys are proposed, 
all denning habitat within the boundaries of the seismic surveys will 
be surveyed three times, and a third survey will be conducted on 
denning habitat along the pipeline between Badami and the road to 
Endicott Island. Greater detail on the timing of these surveys can be 
found in Methods for Modeling the Effects of Den Disturbance.
    A suspected heat signature observed in a potential den found via 
AIR is classified into three categories: A hotspot, a revisit, or a 
putative den. The following designations are discussed below.
    A ``hotspot'' is a warm spot found on the AIR camera indicative of 
a polar bear den through the examination of the size and shape near the 
middle of the snow drift. Signs of wildlife presence (e.g., digging, 
tracks) may be present and visible. Suspected dens that are open (i.e., 
not drifted closed by the snow) are considered hotspots because polar 
bears may dig multiple test evacuation sites when searching for an 
appropriate place to den and unused dens will cool down and be excluded 
from consideration. Hotspots are reexamined and either eliminated or 
upgraded to a ``putative den'' designation. Industry representatives, 
in coordination and compliance with the Service, may utilize other 
methods outside of AIR to gather additional information on a suspected 
hotspot.
    A ``revisit'' is a designation for a warm spot in a snowdrift but 
lacking signs of a polar bear den (e.g., tailings pile, signs of animal 
activity, appropriate shape or size). These categorizations are often 
revisited during a subsequent survey, upgraded to a ``hotspot'' 
designation, or eliminated from further consideration pending the 
evidence presented.
    A ``putative den'' is a hotspot that has maintained a distinct heat 
signature longer than a day and is found within the appropriate 
habitat. The area may show evidence of an animal's presence that may 
not definitively be attributed to a non-polar bear species or cause 
(e.g., a fox or other animal digging). The final determination is often 
unknown as these sites are not investigated further, monitored, or 
revisited in the spring.
    When and if a putative den is found near planned or existing 
infrastructure or activities, the Industry representatives will 
immediately cease operations within 1 mile of the location and 
coordinate with the Service to mitigate any potential disturbances 
while further information is obtained.

Evaluation of the Nature and Level of Activities

    The annual level of activity at existing production facilities in 
the Request will be similar to that which occurred under the previous 
regulations. The increase in the area of the industrial footprint with 
the addition of new facilities, such as drill pads, pipelines, and 
support facilities, is at a rate consistent with prior 5-year 
regulatory periods. Additional onshore and offshore facilities are 
projected within the timeframe of these regulations and will add to the 
total permanent activities in the area. This rate of expansion is 
similar to prior production schedules.

Description of Marine Mammals in the Specified Geographic Region

Polar Bear

    Polar bears are distributed throughout the ice-covered seas and 
adjacent coasts of the Arctic region. The current total polar bear 
population is estimated at approximately 26,000 individuals (95 percent 
Confidence Interval (CI) = 22,000-31,000, Wiig et al. 2015; Regehr et 
al. 2016) and comprises 19 stocks ranging across 5 countries and 4 
ecoregions that reflect the polar bear dependency on sea-ice dynamics 
and seasonality (Amstrup et al. 2008). Two stocks occur in the United 
States (Alaska) with ranges that extend to adjacent countries: Canada 
(the Southern Beaufort Sea (SBS) stock) and the Russia Federation (the 
Chukchi/Bering Seas stock). The discussion below is focused on the 
Southern Beaufort Sea stock of polar bears, as the proposed activities 
in this ITR would overlap only their distribution.
    Polar bears typically occur at low, uneven densities throughout 
their circumpolar range (DeMaster and Stirling 1981, Amstrup et al. 
2011, Hamilton and Derocher 2019) in areas where the sea is ice-covered 
for all or part of the year. They are typically most abundant on sea-
ice, near polynyas (i.e., areas of persistent open water) and

[[Page 43002]]

fractures in the ice, and over relatively shallow continental shelf 
waters with high marine productivity (Durner et al. 2004). This sea-ice 
habitat favors foraging for their primary prey, ringed seals (Pusa 
hispida), and other species such as bearded seals (Erignathus barbatus) 
(Thiemann et al. 2008, Cherry et al. 2011, Stirling and Derocher 2012). 
Although over most of their range polar bears prefer to remain on the 
sea-ice year-round, an increasing proportion of stocks are spending 
prolonged periods of time onshore (Rode et al. 2015, Atwood et al. 
2016b). While time spent on land occurs primarily in late summer and 
autumn (Rode et al. 2015, Atwood et al. 2016b), they may be found 
throughout the year in the onshore and nearshore environments. Polar 
bear distribution in coastal habitats is often influenced by the 
movement of seasonal sea ice (Atwood et al. 2016b, Wilson et al. 2017) 
and its direct and indirect effects on foraging success and, in the 
case of pregnant females, also dependent on availability of suitable 
denning habitat (Durner et al. 2006, Rode et al. 2015, Atwood et al. 
2016b).
    In Alaska during the late summer/fall period (July through 
November), polar bears from the Southern Beaufort Sea stock often occur 
along the coast and barrier islands, which serve as travel corridors, 
resting areas, and to some degree, foraging areas. Based on Industry 
observations and coastal survey data acquired by the Service (Wilson et 
al. 2017), encounter rates between humans and polar bears are higher 
during the fall (July to November) than in any other season, and an 
average of 140 polar bears may occur on shore during any week during 
the period July through November between Utqiagvik and the Alaska--
Canada border (Wilson et al. 2017). The length of time bears spend in 
these coastal habitats has been linked to sea ice dynamics (Rode et al. 
2015, Atwood et al. 2016b). The remains of subsistence-harvested 
bowhead whales at Cross and Barter islands provide a readily available 
food attractant in these areas (Schliebe et al. 2006). However, the 
contribution of bowhead carcasses to the diet of SBS polar bears varies 
annually (e.g., estimated as 11-26 percent and 0-14 percent in 2003 and 
2004, respectively) and by sex, likely depending on carcass and seal 
availability as well as ice conditions (Bentzen et al. 2007).
    Polar bears have no natural predators (though cannibalism is known 
to occur; Stirling et al. 1993, Amstrup et al. 2006b). However, their 
life-history (e.g., late maturity, small litter size, prolonged 
breeding interval) is conducive to low intrinsic population growth 
(i.e., growth in the absence of human-caused mortality), which was 
estimated at 6 percent to 7.5 percent for the SBS stock during 2004-
2006 (Regehr et al. 2010; Hunter et al. 2010). The lifespan of wild 
polar bears is approximately 25 years (Rode et al. 2020). Females reach 
sexual maturity at 3-6 years old giving birth 1 year later (Ramsay and 
Stirling 1988). In the SBS region, females typically give birth at 5 
years old (Lentfer & Hensel 1980). On average, females in the SBS 
produce litter sizes of 1.9 cubs (SD=0.5; Smith et al. 2007, 2010, 
2013; Robinson 2014) at intervals that vary from 1 to 3 or more years 
depending on cub survival (Ramsay and Stirling 1988) and foraging 
conditions. For example, when foraging conditions are unfavorable, 
polar bears may delay reproduction in favor of survival (Derocher and 
Stirling 1992; Eberhardt 2002). The determining factor for growth of 
polar bear stocks is adult female survival (Eberhardt 1990). In 
general, rates above 90 percent are essential to sustain polar bear 
stocks (Amstrup and Durner 1995) given low cub litter survival, which 
was estimated at 50 percent (90 percent CI: 33-67 percent) for the SBS 
stock during 2001-2006 (Regehr et al. 2010). In the SBS, the 
probability that adult females will survive and produce cubs-of-the-
year is negatively correlated with ice-free periods over the 
continental shelf (Regehr et al. 2007a). In general, survival of cubs-
of-the-year is positively related to the weight of the mother and their 
own weight (Derocher and Stirling 1996; Stirling et al. 1999).
    Females without dependent cubs typically breed in the spring 
(Amstrup 2003, Stirling et al. 2016). Pregnant females enter maternity 
dens between October and December (Durner et al. 2001; Amstrup 2003), 
and young are usually born between early December and early January 
(Van de Velde et al. 2003). Only pregnant females den for an extended 
period during the winter (Rode et al. 2018). Other polar bears may 
excavate temporary dens to escape harsh winter conditions; however, 
shelter denning is rare for Alaskan polar bear stocks (Olson et al. 
2017).
    Typically, SBS females denning on land emerge from the den with 
their cubs around mid-March (median emergence: March 11, Rode et al. 
2018, USGS 2018), and commonly begin weaning when cubs are 
approximately 2.3-2.5 years old (Ramsay and Stirling 1986, Arnould and 
Ramsay 1994, Amstrup 2003, Rode 2020). Cubs are born blind, with 
limited fat reserves, and are able to walk only after 60-70 days (Blix 
and Lentfer 1979; Kenny and Bickel 2005). If a female leaves a den 
during early denning, cub mortality is likely to occur due to a variety 
of factors including susceptibility to cold temperatures (Blix and 
Lentfer 1979, Hansson and Thomassen 1983, Van de Velde 2003), predation 
(Derocher and Wiig 1999, Amstrup et al. 2006b), and mobility 
limitations (Lentfer 1975). Therefore, it is thought that successful 
denning, birthing, and rearing activities require a relatively 
undisturbed environment. A more detailed description of the potential 
consequences of disturbance to denning females can be found below in 
Potential Effects of Oil and Gas Industry Activities on Pacific Walrus, 
Polar Bear, and Prey Species: Polar Bear: Effects to Denning Bears. 
Radio and satellite telemetry studies indicate that denning can occur 
in multiyear pack ice and on land (Durner et al. 2020). The proportion 
of dens on land has been increasing along the Alaska region (34.4 
percent in 1985-1995 to 55.2 percent in 2007-2013; Olson et al. 2017) 
likely in response to reductions in stable old ice, which is defined as 
sea ice that has survived at least one summer's melt (Bowditch 2002), 
increases in unconsolidated ice, and lengthening of the melt season 
(Fischbach et al. 2007, Olson et al. 2017). If sea-ice extent in the 
Arctic continues to decrease and the amount of unstable ice increases, 
a greater proportion of polar bears may seek to den on land (Durner et 
al. 2006, Fischbach et al. 2007, Olson et al. 2017).
    In Alaska, maternal polar bear dens occur on barrier islands 
(linear features of low-elevation land adjacent to the main coastline 
that are separated from the mainland by bodies of water), river bank 
drainages, and deltas (e.g., those associated with the Colville and 
Canning Rivers), much of the North Slope coastal plain (in particular 
within the 1002 Area, i.e., the land designated in section 1002 of the 
Alaska National Interest Lands Conservation Act--part of ANWR in 
northeastern Alaska; Amstrup 1993, Durner et al. 2006), and coastal 
bluffs that occur at the interface of mainland and marine habitat 
(Durner et al. 2006, 2013, 2020; Blank 2013; Wilson and Durner 2020). 
These types of terrestrial habitat are also designated as critical 
habitat for the polar bear under the Endangered Species Act (75 FR 
76086, December 7, 2010). Management and conservation concerns for the 
SBS and Chukchi/Bering Seas (CS) polar bear stocks include sea-ice loss 
due to climate change, human-bear conflict, oil and gas industry 
activity, oil spills and contaminants, marine shipping, disease, and 
the potential for

[[Page 43003]]

overharvest (Regehr et al. 2017; U.S. Fish and Wildlife Service 2016). 
Notably, reductions in physical condition, growth, and survival of 
polar bears have been associated with declines in sea-ice (Rode et al. 
2014, Bromaghin et al. 2015, Regehr et al. 2007, Lunn et al. 2016). The 
attrition of summer Arctic sea-ice is expected to remain a primary 
threat to polar bear populations (Amstrup et al. 2008, Stirling and 
Derocher 2012), since projections indicate continued climate warming at 
least through the end of this century (Atwood et al. 2016a, IPCC 2014) 
(see section on Climate Change for further details).
    In 2008, the Service listed polar bears as threatened under the 
Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.; 
ESA) due to the loss of sea-ice habitat caused by climate change (73 FR 
28212, May 15, 2008). The Service later published a final rule under 
section 4(d) of the ESA for the polar bear, which was vacated and then 
reinstated when procedural requirements were satisfied (78 FR 11766, 
February 20, 2013). This section 4(d) rule provides for measures that 
are necessary and advisable for the conservation of polar bears. 
Specifically, the 4(d) rule: (a) Adopts the conservation regulatory 
requirements of the MMPA and the Convention on International Trade in 
Endangered Species of Wild Fauna and Flora (CITES) for the polar bear 
as the appropriate regulatory provisions, in most instances; (b) 
provides that incidental, nonlethal take of polar bears resulting from 
activities outside the bear's current range is not prohibited under the 
ESA; (c) clarifies that the 4(d) rule does not alter the section 7 
consultation requirements of the ESA; and (d) applies the standard ESA 
protections for threatened species when an activity is not covered by 
an MMPA or CITES authorization or exemption.
    The Service designated critical habitat for polar bear populations 
in the United States effective January 6, 2011 (75 FR 76086, December 
7, 2010). The designation of critical habitat identifies geographic 
areas that contain features that are essential for the conservation of 
a threatened or endangered species and that may require special 
management or protection. Under section 7 of the ESA, if there is a 
Federal action, the Service will analyze the potential impacts of the 
action upon polar bears and any designated critical habitat. Polar bear 
critical habitat units include barrier island habitat, sea-ice habitat 
(both described in geographic terms), and terrestrial denning habitat 
(a functional determination). Barrier island habitat includes coastal 
barrier islands and spits along Alaska's coast; it is used for denning, 
refuge from human disturbance, access to maternal dens and feeding 
habitat, and travel along the coast. Sea-ice habitat is located over 
the continental shelf and includes water 300 m (~984 ft) or less in 
depth. Terrestrial denning habitat includes lands within 32 km (~20 mi) 
of the northern coast of Alaska between the Canadian border and the 
Kavik River and within 8 km (~5 mi) between the Kavik River and 
Utqia[gdot]vik. The total area designated under the ESA as critical 
habitat covers approximately 484,734 km\2\ (~187,157 mi\2\) and is 
entirely within the lands and waters of the United States. Polar bear 
critical habitat is described in detail in the final rule that 
designated polar bear critical habitat (75 FR 76086, December 7, 2010). 
A digital copy of the final critical habitat rule is available at: 
http://www.fws.gov/r7/fisheries/mmm/polarbear/pdf/federal_register_notice.pdf.
Stock Size and Range
    In Alaska, polar bears have historically been observed as far south 
in the Bering Sea as St. Matthew Island and the Pribilof Islands (Ray 
1971). A detailed description of the SBS polar bear stock can be found 
in the Service's revised Polar Bear (Ursus maritimus) Stock Assessment 
Report (86 FR 33337, June 24, 2021). Digital copies of these Stock 
Assessment Report is are available at: https://www.fws.gov/alaska/sites/default/files/2021-06/Southern%20Beaufort%20Sea%20SAR%20Final_May%2019rev.pdf. and https://www.fws.gov/alaska/sites/default/files/2021-06/Chukchi_Bering%20Sea%20SAR%20Final%20May%2019%20rev.pdf.
Southern Beaufort Sea Stock
    The SBS polar bear stock is shared between Canada and Alaska. 
Radio-telemetry data, combined with ear tag returns from harvested 
bears, suggest that the SBS stock occupies a region with a western 
boundary near Icy Cape, Alaska (Scharf et al. 2019), and an eastern 
boundary near Tuktoyaktuk, Northwest Territories, Canada (Durner et al. 
2018).
    The most recent population estimates for the Alaska SBS stock were 
produced by the U.S. Geological Survey (USGS) in 2020 (Atwood et al. 
2020) and are based on mark-recapture and collared bear data collected 
from the SBS stock from 2001 to 2016. The SBS stock declined from 2003 
to 2006 (this was also reported by Bromaghin et al. 2015) but 
stabilized from 2006 through 2015. The stock may have increased in size 
from 2009 to 2012; however, low survival in 2013 appears to have offset 
those gains. Atwood et al. (2020) provide estimates for the portion of 
the SBS stock only within the State of Alaska; however, their updated 
abundance estimate from 2015 is consistent with the estimate from 
Bromaghin et al. (2015) for 2010. Thus, the number of bears in the SBS 
stock is thought to have remained constant since the Bromaghin et al. 
(2015) estimate of 907 bears. This number is also supported by survival 
rate estimates provided by Atwood et al. (2020) that were relatively 
high in 2001-2003, decreased during 2004-2008, then improved in 2009, 
and remained high until 2015, except for much lower rates in 2012.

Pacific Walrus

    Pacific walruses constitute a single panmictic population (Beatty 
et al. 2020) primarily inhabiting the shallow continental shelf waters 
of the Bering and Chukchi Seas where their distribution is largely 
influenced by the extent of the seasonal pack ice and prey densities 
(Lingqvist et al. 2009; Berta and Churchill 2012; USFWS 2017). From 
April to June, most of the population migrates from the Bering Sea 
through the Bering Strait and into the Chukchi Sea along lead systems 
that develop in the sea-ice and that are closely associated with the 
edge of the seasonal pack ice during the open-water season (Truhkin and 
Simokon 2018). By July, tens of thousands of animals can be found along 
the edge of the pack ice from Russian waters to areas west of Point 
Barrow, Alaska (Fay 1982; Gilbert et al. 1992; Belikov et al. 1996; 
USFWS 2017). The pack ice has historically advanced rapidly southward 
in late fall, and most walruses return to the Bering Sea by mid- to 
late-November. During the winter breeding season, walruses are found in 
three concentration areas in the Bering Sea where open leads, polynyas, 
or thin ice occur (Fay 1982; Fay et al. 1984, Garlich-Miller et al. 
2011a; Duffy-Anderson et al. 2019). While the specific location of 
these groups varies annually and seasonally depending upon the extent 
of the sea-ice, generally one group occurs near the Gulf of Anadyr, 
another south of St. Lawrence Island, and a third in the southeastern 
Bering Sea south of Nunivak Island into northwestern Bristol Bay (Fay 
1982; Mymrin et al. 1990; Garlich-Miller et al. 2011 USFWS 2017).
    Although most walruses remain either in the Chukchi (for adult 
females and dependent young) or Bering (for adult males) Seas 
throughout the summer

[[Page 43004]]

months, a few occasionally range into the Beaufort Sea in late summer 
(Mymrin et al. 1990; Garlich-Miller and Jay 2000; USFWS 2017). Industry 
monitoring reports have observed no more than 38 walruses in the 
Beaufort Sea ITR geographic region between 1995 and 2015, with only a 
few instances of disturbance to those walruses (AES Alaska 2015, 
Kalxdorff and Bridges 2003, USFWS unpubl. data). The USGS and the 
Alaska Department of Fish and Game (ADF&G) have fitted between 30-60 
walruses with satellite transmitters each year during spring and summer 
since 2008 and 2013 respectively. In 2014, a female tagged by ADF&G 
spent about 3 weeks in Harrison Bay, Beaufort Sea (ADF&G 2014). The 
USGS tracking data indicates that at least one tagged walrus ventured 
into the Beaufort Sea for brief periods in all years except 2011. Most 
of these movements extend northeast of Utqiagvik to the continental 
shelf edge north of Smith Bay (USGS 2015). All available information 
indicates that few walruses currently enter the Beaufort Sea and those 
that do, spend little time there. The Service and USGS are conducting 
multiyear studies on the walrus population to investigate movements and 
habitat use patterns, as it is possible that as sea-ice diminishes in 
the Chukchi Sea beyond the 5-year period of this rule, walrus 
distribution and habitat use may change.
    Walruses are generally found in waters of 100 m (328 ft) or less 
where they utilize sea-ice for passive transportation and rest over 
feeding areas, avoid predators, and birth and nurse their young (Fay 
1982; Ray et al. 2006; Rosen 2020). The diet of walruses consists 
primarily of benthic invertebrates, most notably mollusks (Class 
Bivalvia) and marine worms (Class Polychaeta) (Fay 1982; Fay 1985; 
Bowen and Siniff 1999; Born et al. 2003; Dehn et al. 2007; Sheffield 
and Grebmeier 2009; Maniscalco et al. 2020). When foraging, walruses 
are capable of diving to great depths with most dives lasting between 5 
and 10 minutes with a 1-2-minute surface interval (Fay 1982; Bowen and 
Siniff 1999; Born et al. 2003; Dehn et al. 2007; Sheffield and 
Grebmeier 2009). The foraging activity of walruses is thought to have a 
significant influence on the ecology of the Bering and Chukchi Seas by 
disturbing the sea floor, thereby releasing nutrients into the water 
column that provide food for scavenger organisms and contributing to 
the diversity of the benthic community (Oliver et al. 1983; Klaus et 
al. 1990; Ray et al. 2006). In addition to feeding on benthic 
invertebrates, native hunters have also reported incidences of walruses 
preying on seals, fish, and other vertebrates (Fay 1982; Sheffield and 
Grebmeier 2009; Seymour et al. 2014).
    Walruses are social and gregarious animals that often travel and 
haul-out onto ice or land in groups where they spend approximately 20-
30 percent of their time out of the water (Gilbert 1999; Kastelien 
2002; Jefferson et al. 2008; Monson et al. 2013; USFWS 2017). Hauled-
out walruses tend to be in close physical contact, with groups ranging 
from a few animals up to tens of thousands of individuals--the largest 
aggregations occurring at land haul-outs (Gilbert 1999; Monson et al. 
2013; MacCracken 2017). In recent years, the barrier islands north of 
Point Lay, Alaska, have held large aggregations of walruses (20,000-
40,000) in late summer and fall (Monson et al. 2013; USFWS 2017).
    The size of the walrus population has never been known with 
certainty. Based on large sustained harvests in the 18th and 19th 
centuries, Fay (1957) speculated that the pre-exploitation population 
was represented by a minimum of 200,000 animals. Since that time, 
population size following European contact fluctuated markedly in 
response to varying levels of human exploitation. Large-scale 
commercial harvests are thought to have reduced the population to 
50,000-100,000 animals in the mid-1950s (Fay et al. 1989). Following 
the implementation of harvest regulations in the 1960s and 1970s, which 
limited the take of females, the population increased rapidly and 
likely reached or exceeded the food-based carrying capacity of the 
region by 1980 (Fay et al. 1989, Fay et al. 1997, Garlich-Miller et al. 
2006, MacCracken et al. 2014).
    Between 1975 and 1990, aerial surveys conducted jointly by the 
United States and Russia at 5-year intervals produced population 
estimates ranging from about 200,000 to 255,000 individuals with large 
confidence intervals (Fay 1957; Fay 1982; Speckman et al. 2011). 
Efforts to survey the walrus population were suspended by both 
countries after 1990 following problems with survey methods that 
severely limited their utility. In 2006, the United States and Russia 
conducted another joint aerial survey in the pack ice of the Bering Sea 
using thermal imaging systems to more accurately count walruses hauled 
out on sea-ice and applied satellite transmitters to account for 
walruses in the water (Speckman et al. 2011). In 2013, the Service 
began a genetic mark-recapture study to estimate population size. An 
initial analysis of data in the period 2013-2015 led to the most recent 
estimate of 283,213 Pacific walruses with a 95% confidence interval of 
93,000 to 478,975 individuals (Beatty 2017). Although this is the most 
recent estimate of Pacific walrus population size, it should be used 
with caution as it is preliminary.
    Taylor and Udevitz (2015) used data from five aerial surveys and 
with ship-based age and sex composition counts that occurred in 1981-
1984, 1998, and 1999 (Citta et al. 2014) in a Bayesian integrated 
population model to estimate population trends and vital rates in the 
period 1975-2006. They recalculated the 1975-1990 aerial survey 
estimates based on a lognormal distribution for inclusion in their 
model. Their results generally agreed with the large-scale population 
trends identified by Citta et al. (2014) but with slightly different 
population estimates in some years along with more precise confidence 
intervals. Ultimately, Taylor and Udevitz (2015) concluded (i) that 
though their model provides improved clarity on past walrus population 
trends and vital rates, it cannot overcome the large uncertainties in 
the available population size data, and (ii) that the absolute size of 
the Pacific walrus population will continue to be speculative until 
accurate empirical estimation of the population size becomes feasible.
    A detailed description of the Pacific walrus stock can be found in 
the Pacific Walrus (Odobenus rosmarus divergens) Species Status 
Assessment (USFWS 2017). A digital copy of the Species Status 
Assessment is available at: https://ecos.fws.gov/ServCat/DownloadFile/132114?Reference=86869.
    Polar bears are known to prey on walruses, particularly calves, and 
killer whales (Orcinus orca) have been known to take all age classes of 
walruses (Frost et al. 1992, Melnikov and Zagrebin 2005; Rode et al. 
2014; Truhkin and Simokon 2018). Predation rates are unknown but are 
thought to be highest near terrestrial haulout sites where large 
aggregations of walruses can be found; however, few observations exist 
of predation upon walruses further offshore.
    Walruses have been hunted by coastal Alaska Natives and native 
people of the Chukotka, Russian Federation, for thousands of years (Fay 
et al. 1989). Exploitation of the walrus population by Europeans has 
also occurred in varying degrees since the arrival of exploratory 
expeditions (Fay et al. 1989). Commercial harvest of walruses ceased in 
the United States in 1941, and sport

[[Page 43005]]

hunting ceased in 1972 with the passage of the MMPA and ceased in 1990 
in Russia. Presently, walrus hunting in Alaska is restricted to 
subsistence use by Alaska Natives. Harvest mortality during 2000-2018 
for both the United States and Russian Federation averaged 3,207 (SE = 
194) walruses per year. This mortality estimate includes corrections 
for under-reported harvest and struck and lost animals. Harvests have 
been declining by about 3 percent per year since 2000 and were 
exceptionally low in the United States in 2012-2014. Resource managers 
in Russia have concluded that the population has declined and have 
reduced harvest quotas in recent years accordingly (Kochnev 2004; 
Kochnev 2005; Kochnev 2010; pers. comm.; Litovka 2015, pers. comm.) 
based in part on the lower abundance estimate generated from the 2006 
survey. Total harvest quotas in Russia were further decreased in 2020 
to 1,088 walruses (Ministry of Agriculture of the Russian Federation 
Order of March 23, 2020). Intra-specific trauma at coastal haulouts is 
also a known source of injury and mortality (Garlich-Miller et al. 
2011). The risk of stampede-related injuries increases with the number 
of animals hauled out and with the duration spent on coastal haulouts, 
with calves and young being the most vulnerable to suffer injuries and/
or mortality (USFWS 2017). However, management and protection programs 
in both the United States and the Russian Federation have been somewhat 
successful in reducing disturbances and large mortality events at 
coastal haulouts (USFWS 2015).

Climate Change

    Global climate change will impact the future of both Pacific walrus 
and polar bear populations. As atmospheric greenhouse gas 
concentrations increase so will global temperatures (Pierrehumbert 
2011; IPCC 2014) with substantial implications for the Arctic 
environment and its inhabitants (Bellard et al. 2012, Scheffers et al. 
2016, Harwood et al. 2001, Nunez et al. 2019). The Arctic has warmed at 
twice the global rate (IPCC 2014), and long-term data sets show that 
substantial reductions in both the extent and thickness of Arctic sea-
ice cover have occurred over the past 40 years (Meier et al. 2014, Frey 
et al. 2015). Stroeve et al. (2012) estimated that, since 1979, the 
minimum area of fall Arctic sea-ice declined by over 12 percent per 
decade through 2010. Record low minimum areas of fall Arctic sea-ice 
extent were recorded in 2002, 2005, 2007, and 2012. Further, 
observations of sea-ice in the Beaufort Sea have shown a trend since 
2004 of sea-ice break-up earlier in the year, re-formation of sea-ice 
later in the year, and a greater proportion of first-year ice in the 
ice cover (Galley et al. 2016). The overall trend of decline of Arctic 
sea-ice is expected to continue for the foreseeable future (Stroeve et 
al. 2007; Amstrup et al. 2008; Hunter et al. 2010; Overland and Wang 
2013; 73 FR 28212, May 15, 2008; IPCC 2014). Decline in Arctic sea ice 
affects Arctic species through habitat loss and altered trophic 
interactions. These factors may contribute to population distribution 
changes, population mixing, and pathogen transmission (Post et al. 
2013), which further impact population health.
    For polar bears, sea-ice habitat loss due to climate change has 
been identified as the primary cause of conservation concern (e.g., 
Stirling and Derocher 2012, Atwood et al. 2016b, USFWS 2016). A 42 
percent loss of optimal summer polar bear habitat throughout the Arctic 
is projected for the decade of 2045-2054 (Durner et al. 2009). A recent 
global assessment of the vulnerability of the 19 polar bear stocks to 
future climate warming ranked the SBS as one of the three most 
vulnerable stocks (Hamilton and Derocher 2019). The study, which 
examined factors such as the size of the stock, continental shelf area, 
ice conditions, and prey diversity, attributed the high vulnerability 
of the SBS stock primarily to deterioration of ice conditions. The SBS 
polar bear stock occurs within the Polar Basin Divergent Ecoregion 
(PBDE), which is characterized by extensive sea-ice formation during 
the winters and the sea ice melting and pulling away from the coast 
during the summers (Amstrup et al. 2008). Projections show that polar 
bear stocks within the PBDE may be extirpated within the next 45-75 
years at current rates of sea-ice declines (Amstrup et al. 2007, 
Amstrup et al. 2008). Atwood et al. (2016) also predicted that polar 
bear stocks within the PBDE will be more likely to greatly decrease in 
abundance and distribution as early as the 2020-2030 decade primarily 
as a result of sea-ice habitat loss.
    Sea-ice habitat loss affects the distribution and habitat use 
patterns of the SBS polar bear stock. When sea ice melts during the 
summer, polar bears in the PBDE may either stay on land throughout the 
summer or move with the sea ice as it recedes northward (Durner et al. 
2009). The SBS stock, and to a lesser extent the Chukchi Sea stock, are 
increasingly utilizing marginal habitat (i.e., land and ice over less 
productive waters) (Ware et al. 2017). Polar bear use of Beaufort Sea 
coastal areas has increased during the fall open-water period (June 
through October). Specifically, the percentage of radio-collared adult 
females from the SBS stock utilizing terrestrial habitats has tripled 
over 15 years, and SBS polar bears arrive onshore earlier, stay longer, 
and leave to the sea ice later (Atwood et al. 2016b). This change in 
polar bear distribution and habitat use has been correlated with 
diminished sea ice and the increased distance of the pack ice from the 
coast during the open-water period (i.e., the less sea ice and the 
farther from shore the leading edge of the pack ice is, the more bears 
are observed onshore) (Schliebe et al. 2006; Atwood et al. 2016b).
    The current trend for sea-ice in the SBS region will result in 
increased distances between the ice edge and land, likely resulting in 
more bears coming ashore during the open-water period (Schliebe et al. 
2008). More polar bears on land for a longer period of time may 
increase both the frequency and the magnitude of polar bear exposure to 
human activities, including an increase in human-bear interactions 
(Towns et al. 2009, Schliebe et al. 2008, Atwood et al. 2016b). Polar 
bears spending more time in terrestrial habitats also increases their 
risk of exposure to novel pathogens that are expanding north as a 
result of a warmer Arctic (Atwood et al. 2016b, 2017). Heightened 
immune system activity and more infections (indicated by elevated 
number of white blood cells) have been reported for the SBS polar bears 
that summer on land when compared to those on sea ice (Atwood et al. 
2017; Whiteman et al. 2019). The elevation in immune system activity 
represents additional energetic costs that could ultimately impact 
stock and individual fitness (Atwood et al. 2017; Whiteman et al. 
2019). Prevalence of parasites such as the nematode Trichinella nativa 
in many Arctic species, including polar bears, pre-dates the recent 
global warming. However, parasite prevalence could increase as a result 
of changes in diet (e.g., increased reliance on conspecific scavenging) 
and feeding habits (e.g., increased consumption of seal muscle) 
associated with climate-induced reduction of hunting opportunities for 
polar bears (Penk et al. 2020, Wilson et al. 2017).
    The continued decline in sea-ice is also projected to reduce 
connectivity among polar bear stocks and potentially lead to the 
impoverishment of genetic diversity that is key to maintaining viable, 
resilient wildlife populations (Derocher et al. 2004, Cherry et al. 
2013, Kutchera et al. 2016). The circumpolar polar bear population has 
been divided into six genetic clusters: The Western Polar Basin (which 
includes the SBS

[[Page 43006]]

and CS stocks), the Eastern Polar Basin, the Western and Eastern 
Canadian Archipelago, and Norwegian Bay (Malenfant et al. 2016). There 
is moderate genetic structure among these clusters, suggesting polar 
bears broadly remain in the same cluster when breeding. While there is 
currently no evidence for strong directional gene flow among the 
clusters (Malenfant et al. 2016), migrants are not uncommon and can 
contribute to gene flow across clusters (Kutschera et al. 2016). 
Changing sea-ice conditions will make these cross-cluster migrations 
(and the resulting gene flow) more difficult in the future (Kutschera 
et al. 2016).
    Additionally, habitat loss from decreased sea-ice extent may impact 
polar bear reproductive success by reducing or altering suitable 
denning habitat and extending the polar bear fasting season (Rode et 
al. 2018, Stirling and Derocher 2012, Moln[aacute]r et al. 2020). In 
the early 1990s, approximately 50 percent of the annual maternal dens 
of the SBS polar bear stock occurred on land (Amstrup and Gardner 
1994). Along the Alaskan region the proportion of terrestrial dens 
increased from 34.4 percent in 1985-1995 to 55.2 percent in 2007-2013 
(Olson et al. 2017). Polar bears require a stable substrate for 
denning. As sea-ice conditions deteriorate and become less stable, sea-
ice dens can become vulnerable to erosion from storm surges (Fischbach 
et al. 2007). Under favorable autumn snowfall conditions, SBS females 
denning on land had higher reproductive success than SBS females 
denning on sea-ice. Factors that may influence the higher reproductive 
success of females with land-based dens include longer denning periods 
that allow cubs more time to develop, higher snowfall conditions that 
strengthen den integrity throughout the denning period (Rode et al. 
2018), and increased foraging opportunities on land (e.g., scavenging 
on Bowhead whale carcasses) (Atwood et al. 2016b). While SBS polar bear 
females denning on land may experience increased reproductive success, 
at least under favorable snowfall conditions, it is possible that 
competition for suitable denning habitat on land may increase due to 
sea-ice decline (Fischbach et al. 2007) and land-based dens may be more 
vulnerable to disturbance from human activities (Linnell et al. 2000).
    Polar bear reproductive success may also be impacted by declines in 
sea ice through an extended fasting season (Moln[aacute]r et al. 2020). 
By 2100, recruitment is predicted to become jeopardized in nearly all 
polar bear stocks if greenhouse gas emissions remain uncurbed (RCP8.5 
[Representative Concentration Pathway 8.5] scenario) as fasting 
thresholds are increasingly exceeded due to declines in sea-ice across 
the Arctic circumpolar range (Moln[aacute]r et al. 2020). As the 
fasting season increases, most of these 12 stocks, including in the 
SBS, are expected to first experience significant adverse effects on 
cub recruitment followed by effects on adult male survival and lastly 
on adult female survival (Moln[aacute]r et al. 2020). Without 
mitigation of greenhouse gas emissions and assuming optimistic polar 
bear responses (e.g., reduced movement to conserve energy), cub 
recruitment in the SBS stock has possibly been already adversely 
impacted since the late 1980s, while detrimental impacts on male and 
female survival are forecasted to possibly occur in the late 2030s and 
2040s, respectively.
    Extended fasting seasons are associated with poor body condition 
(Stirling and Derocher 2012), and a female's body condition at den 
entry is a critical factor that determines whether the female will 
produce cubs and the cubs' chance of survival during their first year 
(Rode et al. 2018). Additionally, extended fasting seasons will cause 
polar bears to depend more heavily on their lipid reserves for energy, 
which can release lipid-soluble contaminants, such as persistent 
organic pollutants and mercury, into the bloodstream and organ tissues. 
The increased levels of contaminants in the blood and tissues can 
affect polar bear health and body condition, which has implications for 
reproductive success and survival (Jenssen et al. 2015).
    Changes in sea-ice can impact polar bears by altering trophic 
interactions. Differences in sea-ice dynamics, such as the timing of 
ice formation and breakup, as well as changes in sea-ice type and 
concentration, may impact the distribution of polar bears and/or their 
prey's occurrence and reduce polar bears' access to prey. A climate-
induced reduction in overlap between female polar bears and ringed 
seals was detected after a sudden sea-ice decline in Norway that 
limited the ability of females to hunt on sea-ice (Hamilton et al. 
2017). While polar bears are opportunistic and hunt other species, 
their reliance on ringed seals is prevalent across their range 
(Thiemann et al. 2007, 2008; Florko et al. 2020; Rode et al. 2021). 
Male and female polar bears exhibit differences in prey consumption. 
Females typically consume more ringed seals compared to males, which is 
likely related to more limited hunting opportunities for females (e.g., 
prey size constraints) (McKinney et al. 2017, Bourque et al. 2020). 
Female body condition has been positively correlated with consumption 
of ringed seals, but negatively correlated with the consumption of 
bearded seals (Florko et al. 2020). Consequently, females are more 
prone to decreased foraging and reproductive success than males during 
years in which unfavorable sea-ice conditions limit polar bears' access 
to ringed seals (Florko et al. 2020).
    In the SBS stock, adult female and juvenile polar bear consumption 
of ringed seals was negatively correlated with winter Arctic 
oscillation, which affects sea-ice conditions. This trend was not 
observed for male polar bears. Instead, male polar bears consumed more 
bowhead whale as a result of scavenging the carcasses of subsistence-
harvested bowhead whales during years with a longer ice-free period 
over the continental shelf. It is possible that these alterations in 
sea-ice conditions may limit female polar bears' access to ringed 
seals, and male polar bears may rely more heavily on alternative 
onshore food resources in the southern Beaufort Sea region (McKinney et 
al. 2017). Changes in the availability and distribution of seals may 
influence polar bear foraging efficiency. Reduction in sea ice is 
expected to render polar bear foraging energetically more demanding, as 
moving through fragmented sea ice and open-water swimming require more 
energy than walking across consolidated sea ice (Cherry et al. 2009, 
Pagano et al. 2012, Rode et al. 2014, Durner et al. 2017). Inefficient 
foraging can contribute to nutritional stress and poor body condition, 
which can have implications for reproductive success and survival 
(Regehr et al. 2010).
    The decline in Arctic sea ice is associated with the SBS polar bear 
stock spending more time in terrestrial habitats (Schliebe et al. 
2008). Recent changes in female denning habitat and extended fasting 
seasons as a result of sea-ice decline may affect the reproductive 
success of the SBS polar bear stock (Rode et al. 2018; Stirling and 
Derocher 2012; Moln[aacute]r et al. 2020). Other relevant factors that 
could negatively affect the SBS polar bear stock include changes in 
prey availability, reduced genetic diversity through limited population 
connectivity and/or hybridization with other bear species, increased 
exposure to disease and parasite prevalence and/or dissemination, 
impacts of human activities (oil and gas exploration/extraction, 
shipping, harvesting, etc.) and pollution (Post et al. 2013; Hamilton 
and Derocher 2019). Based on the projections of sea-ice decline in the

[[Page 43007]]

Beaufort Sea region and demonstrated impacts on SBS polar bear 
utilization of sea-ice and terrestrial habitats, the Service 
anticipates that polar bear use of the Beaufort Sea coast will continue 
to increase during the open-water season.
    For walruses, climate change may affect habitat and prey 
availability. The loss of Arctic sea ice has affected walrus 
distribution and habitat use in the Bering and Chukchi Seas (Jay et al. 
2012). Walruses use sea ice as a breeding site, a location to birth and 
nurse young, and a protective cover from storms and predation; however, 
if the sea ice retreats north of the continental shelf break in the 
Chukchi Sea, walruses can no longer use it for these purposes. Thus, 
loss of sea ice is associated with increased use of coastal haul-outs 
during the summer, fall, and early winter (Jay et al. 2012). Coastal 
haulouts are potentially dangerous for walruses, as they can stampede 
toward the water when disturbed, resulting in injuries and mortalities 
(Garlich-Miller et al. 2011). Use of land haulouts is also more 
energetically costly, with walruses hauled out on land spending more 
time in water but not foraging than those hauled out on sea ice. This 
difference has been attributed to an increase in travel time in the 
water from land haulouts to foraging areas (Jay et al. 2017). Higher 
walrus abundance at these coastal haulouts may also increase exposure 
to environmentally and density-dependent pathogens (Post et al. 2013). 
Climate change impacts through habitat loss and changes in prey 
availability could affect walrus population stability. It is unknown if 
walruses will utilize the Beaufort Sea more heavily in the future due 
to climate change effects; however, considering the low number of 
walruses observed in the Beaufort Sea (see Take Estimates for Pacific 
Walruses and Polar Bears), it appears that walruses will remain 
uncommon in the Beaufort Sea for the next 5 years.

Potential Effects of the Specified Activities on Subsistence Uses

Polar Bear

    Based on subsistence harvest reports, polar bear hunting is less 
prevalent in communities on the north coast of Alaska than it is in 
west coast communities. There are no quotas under the MMPA for Alaska 
Native polar bear harvest in the Southern Beaufort Sea; however, there 
is a Native-to-Native agreement between the Inuvialuit in Canada and 
the Inupiat in Alaska. This agreement, the Inuvialuit-Inupiat Polar 
Bear Management Agreement, established quotas and recommendations 
concerning protection of denning females, family groups, and methods of 
take. Although this Agreement is voluntary in the United States and 
does not have the force of law, legally enforceable quotas are 
administered in Canada. In Canada, users are subject to provincial 
regulations consistent with the Agreement. Commissioners for the 
Agreement set the original quota at 76 bears in 1988, split evenly 
between the Inuvialuit in Canada and the Inupiat in the United States. 
In July 2010, the quota was reduced to 70 bears per year. Subsequently, 
in Canada, the boundary of the SBS stock with the neighboring Northern 
Beaufort Sea stock was adjusted through polar bear management bylaws in 
the Inuvialuit Settlement Region in 2013, affecting Canadian quotas and 
harvest levels from the SBS stock. The current subsistence harvest 
established under the Agreement of 56 bears total (35 in the United 
States and 21 in Canada) reflect this change.
    The Alaska Native subsistence harvest of polar bears from the SBS 
population has declined. From 1990 to 1999, an average of 42 bears were 
taken annually. The average subsistence harvest decreased to 21 bears 
annually in the period 2000-2010 and 11 bears annually during 2015-
2020. The reason for the decline of harvested polar bears from the SBS 
population is unknown. Alaska Native subsistence hunters and harvest 
reports have not indicated a lack of opportunity to hunt polar bears or 
disruption by Industry activity.

Pacific Walrus

    Few walruses are harvested in the Beaufort Sea along the northern 
coast of Alaska since their primary range is in the Bering and Chukchi 
Seas. Walruses constitute a small portion of the total marine mammal 
harvest for the village of Utqiagvik. Hunters from Utqiagvik have 
harvested 407 walruses since the year 2000 with 65 harvested since 
2015. Walrus harvest from Nuiqsut and Kaktovik is opportunistic. They 
have reported taking four walruses since 1993. None of the walrus 
harvests for Utqiagvik, Nuiqsut, or Kaktovik from 2014 to 2020 occurred 
within the Beaufort Sea ITR region.

Evaluation of Effects of the Specified Activities on Subsistence Uses

    There are three primary Alaska Native communities on the Beaufort 
Sea whose residents rely on Pacific walruses and polar bears for 
subsistence use: Utqiagvik, Nuiqsut, and Kaktovik. Utqiagvik and 
Kaktovik are expected to be less affected by the Industry's proposed 
activities than Nuiqsut. Nuiqsut is located within 5 mi of 
ConocoPhillips' Alpine production field to the north and 
ConocoPhillips' Alpine Satellite development field to the west. 
However, Nuiqsut hunters typically harvest polar bears from Cross 
Island during the annual fall bowhead whaling. Cross Island is 
approximately 16 km (~10 mi) offshore from the coast of Prudhoe Bay. We 
have received no evidence or reports that bears are altering their 
habitat use patterns, avoiding certain areas, or being affected in 
other ways by the existing level of oil and gas activity near 
communities or traditional hunting areas that would diminish their 
availability for subsistence use. However, as is discussed in 
Evaluation of Effects of Specified Activities on Pacific Walruses, 
Polar Bears, and Prey Species below, the Service has found some 
evidence of fewer maternal polar bear dens near industrial 
infrastructure than expected.
    Changes in Industry activity locations may trigger community 
concerns regarding the effect on subsistence uses. Industry must remain 
proactive to address potential impacts on the subsistence uses by 
affected communities through consultations and, where warranted, POCs. 
Evidence of communication with the public about activities will be 
required as part of an LOA. Current methods of communication are 
variable and include venues such as public forums, which allow 
communities to express feedback prior to the initiation of operations, 
the employ of subsistence liaisons, and presentations to regional 
commissions. If community subsistence use concerns arise from new 
activities, appropriate mitigation measures, such as cessation of 
activities in key locations during hunting seasons, are available and 
will be applied as a part of the POC.
    No unmitigable concerns from the potentially affected communities 
regarding the availability of walruses or polar bears for subsistence 
uses have been identified through Industry consultations with the 
potentially affected communities of Utqiagvik, Kaktovik, or Nuiqsut. 
During the 2016-2021 ITR period, Industry groups have communicated with 
Native communities and subsistence hunters through subsistence 
representatives, community liaisons, and village outreach teams as well 
as participation in community and commission meetings. Based on 
information gathered from these sources, it appears that subsistence 
hunting opportunities for walruses and polar bears have not been 
affected by past Industry activities conducted pursuant to the 2016-
2021

[[Page 43008]]

Beaufort ITR and are not likely to be affected by the activities 
described in this ITR. Given the similarity between the nature and 
extent of Industry activities covered by the prior Beaufort Sea ITR and 
those specified in AOGA's pending Request, and the continued 
requirement for Industry to consult and coordinate with Alaska Native 
communities and representative subsistence hunting and co-management 
organizations (and develop a POC if necessary), we do not anticipate 
that the activities specified in AOGA's pending Request will have any 
unmitigable effects on the availability of Pacific walruses or polar 
bears for subsistence uses.

Potential Effects of the Specified Activities on Pacific Walruses, 
Polar Bears, and Prey Species

    Industry activities can affect individual walruses and polar bears 
in numerous ways. Below, we provide a summary of the documented and 
potential effects of oil and gas industrial activities on both polar 
bears and walruses. The effects analyzed included harassment, lethal 
take, and exposure to oil spills.

Polar Bear: Human-Polar Bear Encounters

    Oil and gas industry activities may affect individual polar bears 
in numerous ways during the open-water and ice-covered seasons. Polar 
bears are typically distributed in offshore areas associated with 
multiyear pack ice from mid-November to mid-July. From mid-July to mid-
November, 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. 
This distribution leads to a significantly higher number of human-polar 
bear encounters on land and at offshore structures during the open-
water period than other times of the year. Bears that remain on the 
multiyear pack ice are not typically present in the ice-free areas 
where vessel traffic occurs, as barges and vessels associated with 
Industry activities travel in open water and avoid large ice floes.
    On land, the majority of Industry's bear observations occur within 
2 km (1.2 mi) of the coastline. Industry facilities within the offshore 
and coastal areas are more likely to be approached by polar bears and 
may act as physical barriers to movements of polar bears. As bears 
encounter these facilities, the chances for human-bear interactions 
increase. The Endicott and West Dock causeways, as well as the 
facilities supporting them, have the potential to act as barriers to 
movements of polar bears because they extend continuously from the 
coastline to the offshore facility. However, polar bears have 
frequently been observed crossing existing roads and causeways. 
Offshore production facilities, such as Northstar, Spy Island, and 
Oooguruk, have frequently been approached by polar bears but appear to 
present only an inconsequential small-scale, local obstruction to the 
bears' movement. Of greater concern is the increased potential for 
human-polar bear interaction at these facilities. Encounters are more 
likely to occur during the fall at facilities on or near the coast. 
Polar bear interaction plans, training, and monitoring required by past 
ITRs have proven effective at reducing human-polar bear encounters and 
the risks to bears and humans when encounters occur. Polar bear 
interaction plans detail the policies and procedures that Industry 
facilities and personnel will implement to avoid attracting and 
interacting with polar bears as well as minimizing impacts to the 
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. Industry uses technology to aid in detecting 
polar bears including bear monitors, closed-circuit television, video 
cameras, thermal cameras, radar devices, and motion-detection systems. 
In addition, some companies take steps to actively prevent bears from 
accessing facilities by using safety gates and fences.
    The noises, sights, and smells produced by the proposed project 
activities could disturb and elicit variable responses from polar 
bears. Noise disturbance can originate from either stationary or mobile 
sources. Stationary sources include construction, maintenance, repair 
and remediation activities, operations at production facilities, gas 
flaring, and drilling operations. Mobile sources include aircraft 
traffic, geotechnical surveys, ice road construction, vehicle traffic, 
tracked vehicles, and snowmobiles.
    The potential behavioral reaction of polar bears to the proposed 
activities can vary by activity type. Camp odors may attract polar 
bears, potentially resulting in human-bear encounters, intentional 
hazing, or possible lethal take in defense of human life (see 50 CFR 
18.34 for further guidance on passive polar bear deterrence measures). 
Noise generated on the ground by industrial activity may cause a 
behavioral (e.g., escape response) or physiologic (e.g., increased 
heart rate, hormonal response) (Harms et al. 1997; Tempel and Gutierrez 
2003) response. The available studies of polar bear behavior indicate 
that the intensity of polar bear reaction to noise disturbance may be 
based on previous interactions, sex, age, and maternal status (Anderson 
and Aars 2008; Dyck and Baydack 2004).

Polar Bear: Effects of Aircraft Overflights

    Bears on the surface experience increased noise and visual stimuli 
when planes or helicopters fly above them, both of which may elicit a 
biologically significant behavioral response. Sound frequencies 
produced by aircraft will likely fall within the hearing range of polar 
bears (see Nachtigall et al. 2007) and will thus be audible to animals 
during flyovers or when operating in proximity to polar bears. Polar 
bears likely have acute hearing with previous sensitivities 
demonstrated between 1.4-22.5 kHz (tests were limited to 22.5 kHz; 
Nachtigall et al. 2007). This range, which is wider than that seen in 
humans, supports the idea that polar bears may experience temporary 
(called temporary threshold shift, or TTS) or permanent (called 
permanent threshold shift, or PTS) hearing impairment if they are 
exposed to high-energy sound. While species-specific TTS and PTS 
thresholds have not been established for polar bears, thresholds have 
been established for the general group ``other marine carnivores'' 
which includes both polar bears and walruses (Southall et al. 2019). 
Through a series of systematic modeling procedures and extrapolations, 
Southall et al. (2019) have generated modified noise exposure 
thresholds for both in-air and underwater sound (Table 1).

[[Page 43009]]



   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 Both Polar Bears and Walruses
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                TTS                                             PTS
                                                         -----------------------------------------------------------------------------------------------
                                                           Non-impulsive             Impulsive             Non-impulsive             Impulsive
                                                         -----------------------------------------------------------------------------------------------
                                                              SELCUM          SELCUM         Peak SPL         SELCUM          SELCUM         Peak SPL
--------------------------------------------------------------------------------------------------------------------------------------------------------
Air.....................................................             157             146             161             177             161             167
Water...................................................             199             188             226             219             203             232
--------------------------------------------------------------------------------------------------------------------------------------------------------
Values are weighted for other marine carnivores' hearing thresholds and given in cumulative sound exposure level (SELCUM dB re (20[mu]Pa)2s in air and
  SELCUM dB re (1 [mu]Pa)\2\s in water) for impulsive and non-impulsive sounds, and unweighted peak sound pressure level in air (dB re 20[mu]Pa) and
  water (dB 1[mu]Pa) (impulsive sounds only).

    During an FAA test, test aircraft produced sound at all frequencies 
measured (50 Hz to 10 kHz) (Healy 1974; Newman 1979). 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 Industry is unlikely to cause temporary or permanent 
hearing damage unless marine mammals are very close to the sound 
source. Although temporary or permanent hearing damage is not 
anticipated, impacts from aircraft overflights have the potential to 
elicit biologically significant behavioral responses from polar bears. 
Observations of polar bears during fall coastal surveys, which flew at 
much lower altitudes than typical Industry flights (see Estimating Take 
Rates of Aircraft Activities), indicate that the reactions of non-
denning polar bears is typically varied but limited to short-term 
changes in behavior ranging from no reaction to running away. Bears 
associated with dens have been shown to increase vigilance, initiate 
rapid movement, and even abandon dens when exposed to low-flying 
aircraft (see Effects to Denning Bears for further discussion). 
Aircraft activities can impact bears over all seasons; however, during 
the summer and fall seasons, aircraft have the potential to disturb 
both individuals and congregations of polar bears. These onshore bears 
spend most of their time resting and limiting their movements on land. 
Exposure to aircraft traffic is expected to result in changes in 
behavior, such as going from resting to walking or running and, 
therefore, has the potential to be energetically costly. Mitigation 
measures, such as minimum flight elevations over polar bears and 
habitat areas of concern as well as flight restrictions around known 
polar bear aggregations when safe, are included in this ITR to achieve 
least practicable adverse impact to polar bears by aircraft.

Polar Bear: Effects of In-Water Activities

    In-water sources of sound, such as pile driving, screeding, 
dredging, or vessel movement, may disturb polar bears. In the open-
water season, Industry activities are generally limited to relatively 
ice-free, open water. During this time in the Beaufort Sea, polar bears 
are typically found either on land or on the pack ice, which limits the 
chances of the interaction of polar bears with offshore Industry 
activities. Though polar bears have been observed in open water miles 
from the ice edge or ice floes, the encounters are relatively rare 
(although the frequency of such observations may increase due to sea 
ice change). However, if bears come in contact with Industry operations 
in open water, the effects of such encounters likely include no more 
than short-term behavioral disturbance.
    While polar bears swim in and hunt from open water, they spend less 
time in the water than most marine mammals. Stirling (1974) reported 
that polar bears observed near Devon Island during late July and early 
August spent 4.1 percent of their time swimming and an additional 0.7 
percent engaged in aquatic stalking of prey. More recently, application 
of tags equipped with time-depth recorders indicate that aquatic 
activity of polar bears is greater than was previously thought. In a 
study published by Lone et al. (2018), 75 percent of polar bears swam 
daily during open-water months, with animals spending 9.4 percent of 
their time in July in the water. Both coastal- and pack-ice-dwelling 
animals were tagged, and there were no significant differences in the 
time spent in the water by animals in the two different habitat types. 
While polar bears typically swim with their ears above water, Lone et 
al. (2018) found polar bears in this study that were fitted with depth 
recorders (n=6) spent approximately 24 percent of their time in the 
water with their head underwater. Thus, for the individuals followed as 
a part of the study, an average of 2.2 percent of the day, or 31 
minutes, were spent with their heads underwater.
    The pile driving, screeding, dredging, and other in-water 
activities proposed by Industry introduce substantial levels of noise 
into the marine environment. Underwater sound levels from construction 
along the North Slope have been shown to range from 103 decibels (dB) 
at 100 m (328 ft) for auguring to 143 dB at 100 m (328 ft) for pile 
driving (Greene et al. 2008) with most of the energy below 100 Hz. 
Airborne sound levels from these activities range from 65 dB at 100 m 
(328 ft) for a bulldozer and 81 dB at 100 m (328 ft) for pile driving, 
with most of the energy for in-air levels also below 100 Hz (Greene et 
al. 2008). Therefore, in-water activities are not anticipated to result 
in temporary or permanent damage to polar bear hearing.
    In 2012, during the open-water season, Shell vessels encountered a 
few polar bears swimming in ice-free water more than 70 mi (112.6 km) 
offshore in the Chukchi Sea. In those instances, the bears were 
observed to either swim away from or approach the Shell vessels. 
Sometimes a polar bear would swim around a stationary vessel before 
leaving. In at least one instance a polar bear approached, touched, and 
investigated a stationary vessel from the water before swimming away.
    Polar bears are more likely to be affected by on-ice or in-ice 
Industry activities versus open-water activities. From 2009 through 
2014, there were a few Industry observation reports of polar bears 
during on-ice activities. Those observations were primarily of bears 
moving through an area during winter seismic surveys on near-shore ice. 
The disturbance to bears moving across the surface is frequently 
minimal, short-term, and temporary due to the mobility of such projects 
and limited to

[[Page 43010]]

small-scale alterations to bear movements.

Polar Bear: Effects to Denning Bears

    Known polar bear dens in the Beaufort Sea ITR region, whether 
discovered opportunistically or as a result of planned surveys such as 
tracking marked bears or den detection surveys, are monitored by the 
Service. However, these known denning sites are only a small percentage 
of the total active polar bear dens for the SBS stock in any given 
year. Each year, Industry coordinates with the Service to conduct 
surveys to determine the location of Industry's activities relative to 
known dens and denning habitat. Under past ITRs Industry activities 
have been required to avoid known polar bear dens by 1.6 km (1 mi). 
However, occasionally an unknown den may be encountered during Industry 
activities. When a previously unknown den is discovered in proximity to 
Industry activity, the Service implements mitigation measures such as 
the 1.6-km (1-mi) activity exclusion zone around the den and 24-hour 
monitoring of the site.
    The responses of denning bears to disturbance and the consequences 
of these responses can vary throughout the denning process. 
Consequently, we divide the denning period into four stages when 
considering impacts of disturbance: Den establishment, early denning, 
late denning, and post-emergence.
Den Establishment
    The den establishment period begins in autumn near the time of 
implantation when pregnant females begin scouting for, excavating, and 
occupying a den. The timing of den establishment is likely governed by 
a variety of environmental factors, including snowfall events 
(Zedrosser et al. 2006; Evans et al. 2016; Pigeon et al. 2016), 
accumulation of snowpack (Amstrup and Gardner 1994; Durner et al. 2003, 
2006), temperature (Rode et al. 2018), and timing of sea ice freeze-up 
(Webster et al. 2014). Spatial and temporal variation in these factors 
may explain variability in the timing of den establishment, which 
occurs between October and December in the SBS stock (Durner et al. 
2001; Amstrup 2003). Rode et al. (2018) estimated November 15 as the 
mean date of den entry for bears in the SBS stock.
    The den establishment period ends with the birth of cubs in early 
to mid-winter (Ramsay and Stirling 1988) after a gestation period that 
is likely similar to the ~60-day period documented for brown bears 
(Tsubota et al. 1987). Curry et al. (2015) found the mean and median 
birth dates for captive polar bears in the Northern Hemisphere were 
both November 29. Similarly, Messier et al. (1994) estimated that most 
births had occurred by December 15 in the Canadian Arctic Archipelago 
based on activity levels recorded by sensors on females in maternity 
dens.
    Much of what is known of the effects of disturbance during the den 
establishment period comes from studies of polar bears captured by 
researchers in autumn. Although capture is a severe form of disturbance 
atypical of events likely to occur during oil and gas activities, 
responses to capture can inform our understanding of how polar bears 
respond to substantial levels of disturbance. Ramsay and Stirling 
(1986) reported that 10 of 13 pregnant females that were captured and 
collared at dens in October or November abandoned their existing dens. 
Within 1-2 days after their release, these bears moved a median 
distance of 24.5 km and excavated new maternal dens. The remaining 
three polar bears reentered their initial dens or different dens <2 km 
from their initial den soon after being released. Amstrup (1993, 2003) 
documented a similar response in Alaska and reported 5 of 12 polar 
bears abandoned den sites and subsequently denned elsewhere following 
disturbance during autumn, with the remaining 7 bears remaining at 
their original den site.
    The observed high rate of den abandonment during autumn capture 
events suggests that polar bears have a low tolerance threshold for 
intense disturbance during den initiation and are willing to expend 
energy to avoid further disturbance. Energy expenditures during den 
establishment are not replenished because female ursids do not eat or 
drink during denning and instead rely solely on stored body fat (Nelson 
et al.1983; Spady et al. 2007). Consequently, because female body 
condition during denning affects the size and subsequent survival of 
cubs at emergence from the den (Derocher and Stirling 1996; Robbins et 
al. 2012), disturbances that cause additional energy expenditures in 
fall could have latent effects on cubs in the spring.
    The available published research does not conclusively demonstrate 
the extent to which capture or den abandonment during den initiation is 
consequential for survival and reproduction. Ramsay and Stirling (1986) 
reported that captures (also known as handling) of females did not 
significantly affect numbers and mean weights of cubs, but the overall 
mean litter size and weights of cubs born to previously handled mothers 
consistently tended to be slightly lower than those of mothers not 
previously handled. Amstrup (1993) found no significant effect of 
handling on cub weight, litter size, or survival. Similarly, Seal et 
al. (1970) reported no loss of pregnancy among captive ursids following 
repeated chemical immobilization and handling. However, Lunn et al. 
(2004) concluded that handling and observations of pregnant female 
polar bears in the autumn resulted in significantly lighter female, but 
not male, cubs in spring. Swenson et al. (1997) found that pregnant 
female grizzly bears (U. arctos horribilis) that abandoned excavated 
dens pre-birth lost cubs at a rate 10 times higher (60%) than bears 
that did not abandon dens (6%).
    Although disturbances during the den establishment period can 
result in pregnant females abandoning a den site and/or incurring 
energetic or reproductive costs, fitness consequences are relatively 
small during this period compared to after the birth of cubs because 
females are often able to identify and excavate new sites within the 
temporal period that den establishment occurs under undisturbed 
conditions (Amstrup 1993; Lunn et al. 2004). Consequently, prior to 
giving birth, disturbances are unlikely to result in injury or a 
reduction in the probability of survival of a pregnant female or her 
cubs. However, responses by polar bears to anthropogenic activities can 
lead to the disruption of biologically important behaviors associated 
with denning.
Early Denning
    The second denning period we identified, early denning, begins with 
the birth of cubs and ends 60 days after birth. Polar bear cubs are 
altricial and are among the most undeveloped placental mammals at birth 
(Ramsay and Dunbrack 1986). Newborn polar bears weigh ~0.6 kg, are 
blind, and have limited fat reserves and fur, which provides little 
thermoregulatory value (Blix and Lentfer 1979; Kenny and Bickel 2005). 
Roughly 2 weeks after birth, their ability to thermoregulate begins to 
improve as they grow longer guard hairs and an undercoat (Kenny and 
Bickel 2005). Cubs first open their eyes at approximately 35 days after 
birth (Kenny and Bickel 2005) and achieve sufficient musculoskeletal 
development to walk at 60-70 days (Kenny and Bickel 2005), but 
movements may still be clumsy at this time (Harington 1968). At 
approximately 2 months of age, their capacity for thermoregulation may 
facilitate survival outside of the den and is the minimum time required 
for cubs

[[Page 43011]]

to be able to survive outside of the den. However, further development 
inside the den greatly enhances the probability of survival (Amstrup 
1993, Amstrup and Gardner 1994, Smith et al. 2007, Rode et al. 2018). 
Cubs typically weigh 10-12 kg upon emergence from the den in the spring 
at approximately 3.5 months old (Harington 1968, L[oslash]n[oslash] 
1970).
    Based on these developmental milestones, we consider 60 days after 
birth to mark the end of the early denning period. Currently, we are 
not aware of any studies directly documenting birth dates of polar bear 
cubs in the wild; however, several studies have estimated parturition 
based on indirect metrics. Van de Velde et al. (2003) evaluated 
historic records of bears legally harvested in dens. Their findings 
suggest that cubs were born between early December and early January. 
Additionally, Messier et al. (1994) found that the activity levels of 
radio-collared females dropped significantly in mid-December, leading 
the authors to conclude that a majority of births occurred before or 
around 15 December. Because cub age is not empirically known, we 
consider early denning to end on 13 February, which is 60 days after 
the estimated average birth date of 15 December.
    Although disturbance to denning bears can be costly at any stage in 
the denning process, consequences in early denning can be especially 
high because of the vulnerability of cubs early in their development 
(Elowe and Dodge 1989, Amstrup and Gardner 1994, Rode et al. 2018). If 
a female leaves a den during early denning, cub mortality is likely to 
occur due to a variety of factors including susceptibility to cold 
temperatures (Blix and Lentfer 1979, Hansson and Thomassen 1983, Van de 
Velde 2003), predation (Derocher and Wiig 1999, Amstrup et al. 2006b), 
and mobility limitations (Lentfer 1975). Thus, we can expect a high 
probability that cubs will suffer lethal take if they emerge early 
during this stage. Further, adult females that depart the den site 
during early denning are likely to experience physiological stresses 
such as increased heart rate (Craighead et al. 1976, Laske et al. 2011) 
or increased body temperature (Reynolds et al. 1986) that can result in 
significant energy expenditures (Karprovich et al. 2009, Geiser 2013, 
Evans et al. 2016) thus likely resulting in Level B harassment.
Late Denning
    The third denning period, late denning, begins when cubs are >=60 
days old and ends at den emergence in the spring, which coincides with 
increases in prey availability (Rode et al. 2018b). In the SBS, March 
15th is the median estimated emergence date for land-denning bears 
(Rode et al. 2018b). During late denning, cubs develop the ability to 
travel more efficiently and become less susceptible to heat loss, which 
enhances their ability to survive after leaving the den (Rode et al. 
2018b). For example, date of den emergence was identified as the most 
important variable influencing cub survival in a study of marked polar 
bears in the CS and SBS stocks (Rode et al. 2018b). The authors 
reported that all females that denned through the end of March had >= 
one cub when re-sighted <=100 days after den emergence. Conversely, 
roughly half of the females that emerged from dens before the end of 
February did not have cubs when resighted <=100 days after emergence, 
suggesting that later den emergence likely results in a greater 
likelihood of cub survival (Rode et al. 2018b). Rode et al. (2018b) do 
note several factors that could affect their findings; for example, it 
was not always known whether a female emerged from a den with cubs 
(i.e., cubs died before re-sighting during the spring surveys).
    Although the potential responses of bears to disturbance events 
(e.g., emerging from dens early, abandoning dens, physiological 
changes) during early and late denning are the same, consequences to 
cubs differ based on their developmental progress. In contrast to 
emergences during early denning, which are likely to result in cub 
mortality, emergences during late denning do not necessarily result in 
cub mortality because cubs potentially can survive outside the den 
after reaching approximately 60 days of age. However, because survival 
increases with time spent in the den during late denning, disturbances 
that contribute to an early emergence during late denning are likely to 
increase the probability of cub mortality, thus leading to a serious 
injury Level A harassment. Similar to the early denning period, this 
form of disturbance would also likely lead to Level B harassment for 
adult females.
Post-Emergence
    The post-emergence period begins at den emergence and ends when 
bears leave the den site and depart for the sea ice, which can occur up 
to 30 days after emergence (Harington 1968, Jonkel et al. 1972, 
Kolenoski and Prevett 1980, Hansson and Thomassen 1983, Ovsyanikov 
1998, Robinson 2014). During the post-emergence period, bears spend 
time in and out of the den where they acclimate to surface conditions 
and engage in a variety of activities, including grooming, nursing, 
walking, playing, resting, standing, digging, and foraging on 
vegetation (Harington 1968; Jonkel et al. 1972; Hansson and Thomassen 
1983; Ovsyanikov 1998; Smith et al. 2007, 2013). While mothers outside 
the den spend most of their time resting, cubs tend to be more active, 
which likely increases strength and locomotion (Harington 1968, Lentfer 
and Hensel 1980, Hansson and Thomassen 1983, Robinson 2014). 
Disturbances that elicit an early departure from the den site may 
hinder the ability of cubs to travel (Ovsyanikov 1998), thereby 
increasing the chances for cub abandonment (Haroldson et al. 2002) or 
susceptibility to predation (Derocher and Wiig 1999, Amstrup et al. 
2006b).
    Considerable variation exists in the duration of time that bears 
spend at dens post-emergence, and the relationship between the duration 
and cub survival has not been formally evaluated. However, a maternal 
female should be highly motivated to return to the sea ice to begin 
hunting and replenish her energy stores to support lactation, thus, 
time spent at the den site post emergence likely confers some fitness 
benefit to cubs. A disturbance that leads the family group to depart 
the den site early during this period therefore is likely to lead to a 
non-serious Level A harassment for the cubs and a Level B harassment 
for the adult female.

Walrus: Human-Walrus Encounters

    Walruses do not inhabit the Beaufort Sea frequently and the 
likelihood of encountering walruses during Industry operations is low 
and limited to the open-water season. During the time period of this 
ITR, Industry operations may occasionally encounter small groups of 
walruses swimming in open water or hauled out onto ice floes or along 
the coast. Industry monitoring data have reported 38 walruses between 
1995 and 2015, with only a few instances of disturbance to those 
walruses (AES Alaska 2015, USFWS unpublished data). From 2009 through 
2014, no interactions between walrus and Industry were reported in the 
Beaufort Sea ITR region. We have no evidence of any physical effects or 
impacts to individual walruses due to Industry activity in the Beaufort 
Sea. However, in the Chukchi Sea, where walruses are more prevalent, 
Level B harassment is known to sometimes occur during encounters with 
Industry. Thus, if walruses are encountered during the activities 
proposed in this ITR, the interaction it could potentially result in 
disturbance.
    Human encounters with walruses could occur during Industry 
activities,

[[Page 43012]]

although such encounters would be rare due to the limited distribution 
of walruses in the Beaufort Sea. These encounters may occur within 
certain cohorts of the population, such as calves or animals under 
stress. In 2004, a suspected orphaned calf hauled-out on the armor of 
Northstar Island numerous times over a 48-hour period, causing Industry 
to cease certain activities and alter work patterns before the walrus 
disappeared in stormy seas. Additionally, a walrus calf was observed 
for 15 minutes during an exploration program 60 ft from the dock at 
Cape Simpson in 2006. From 2009 through 2020, Industry reported no 
similar interactions with walruses.
    In the nearshore areas of the Beaufort Sea, stationary offshore 
facilities could produce high levels of noise that have the potential 
to disturb walruses. These include Endicott, Hilcorp's Saltwater 
Treatment Plant (located on the West Dock Causeway), Oooguruk, and 
Northstar facilities. The Liberty project will also have this potential 
when it commences operations. From 2009 through 2020, there were no 
reports of walruses hauling out at Industry facilities in the Beaufort 
Sea ITR region. Previous observations have been reported of walruses 
hauled out on Northstar Island and swimming near the Saltwater 
Treatment Plant. In 2007, a female and a subadult walrus were observed 
hauled-out on the Endicott Causeway. The response of walruses to 
disturbance stimuli is highly variable. Anecdotal observations by 
walrus hunters and researchers suggest that males tend to be more 
tolerant of disturbances than females and individuals tend to be more 
tolerant than groups. Females with dependent calves are considered 
least tolerant of disturbances. In the Chukchi Sea, disturbance events 
are known to cause walrus groups to abandon land or ice haulouts and 
occasionally result in trampling injuries or cow-calf separations, both 
of which are potentially fatal. Calves and young animals at terrestrial 
haulouts are particularly vulnerable to trampling injuries. However, 
due to the scarcity of walrus haulouts in the ITR area, the most likely 
potential impacts of Industry activities include displacement from 
preferred foraging areas, increased stress, energy expenditure, 
interference with feeding, and masking of communications. Any impact of 
Industry presence on walruses is likely to be limited to a few 
individuals due to their geographic range and seasonal distribution.
    The reaction of walruses to vessel traffic is dependent upon vessel 
type, distance, speed, and previous exposure to disturbances. Walruses 
in the water appear to be less readily disturbed by vessels than 
walruses hauled out on land or ice. Furthermore, barges and vessels 
associated with Industry activities travel in open water and avoid 
large ice floes or land where walruses are likely to be found. In 
addition, walruses can use a vessel as a haulout platform. In 2009, 
during Industry activities in the Chukchi Sea, an adult walrus was 
observed hauled out on the stern of a vessel.

Walrus: Effects of In-Water Activities

    Walruses hear sounds both in air and in water. They have been shown 
to hear from 60 hertz (Hz) to 23 kilohertz (kHz) in air (Reichmuth et 
al. 2020). Tests of underwater hearing have shown their range to be 
between 1 kHz and 12 kHz with greatest sensitivity at 12 kHz (Kastelein 
et al. 2002). The underwater hearing abilities of the Pacific walrus 
have not been studied sufficiently to develop species-specific criteria 
for preventing harmful exposure. However, sound pressure level 
thresholds have been developed for members of the ``other carnivore'' 
group of marine mammals (Table 1).
    When walruses are present, underwater noise from vessel traffic in 
the Beaufort Sea may prevent ordinary communication between individuals 
by preventing them from locating one another. It may also prevent 
walruses from using potential habitats in the Beaufort Sea and may have 
the potential to impede movement. Vessel traffic will likely increase 
if offshore Industry expands and may increase if warming waters and 
seasonally reduced sea-ice cover alter northern shipping lanes.
    The most likely response of walruses to acoustic disturbances in 
open water will be for animals to move away from the source of the 
disturbance. Displacement from a preferred feeding area may reduce 
foraging success, increase stress levels, and increase energy 
expenditures.

Walrus: Effects of Aircraft Overflights

    Aircraft overflights may disturb walruses. Reactions to aircraft 
vary with range, aircraft type, and flight pattern as well as walrus 
age, sex, and group size. Adult females, calves, and immature walruses 
tend to be more sensitive to aircraft disturbance. Walruses are 
particularly sensitive to changes in engine noise and are more likely 
to stampede when planes turn or fly low overhead. Researchers 
conducting aerial surveys for walruses in sea-ice habitats have 
observed little reaction to fixed-winged aircraft above 457 m (1,500 
ft) (USFWS unpubl. data). Although the intensity of the reaction to 
noise is variable, walruses are probably most susceptible to 
disturbance by fast-moving and low-flying aircraft (100 m (328 ft) 
above ground level) or aircraft that change or alter speed or 
direction. In the Chukchi Sea, there are recent examples of walruses 
being disturbed by aircraft flying in the vicinity of haulouts. It 
appears that walruses are more sensitive to disturbance when hauled out 
on land versus sea-ice.

Effects to Prey Species

    Industry activity has the potential to impact walrus prey, which 
are primarily benthic invertebrates including bivalves, snails, worms, 
and crustaceans (Sheffield and Grebmeier 2009). The effects of Industry 
activities on benthic invertebrates would most likely result from 
disturbance of seafloor substrate from activities such as dredging or 
screeding, and if oil was illegally discharged into the environment. 
Substrate-borne vibrations associated with vessel noise and Industry 
activities, such as pile driving and drilling, can trigger behavioral 
and physiological responses in bivalves and crustaceans (Roberts et al. 
2016, Tidau and Briffa 2016). In the case of an oil spill, oil has the 
potential to impact benthic invertebrate species in a variety of ways 
including, but not limited to, mortality due to smothering or toxicity, 
perturbations in the composition of the benthic community, as well as 
altered metabolic and growth rates. Additionally, bivalves and 
crustaceans can bioaccumulate hydrocarbons, which could increase walrus 
exposure to these compounds (Engelhardt 1983). Disturbance from 
Industry activity and effects from oil exposure may alter the 
availability and distribution of benthic invertebrate species. An 
increasing number of studies are examining benthic invertebrate 
communities and food web structure within the Beaufort Sea (Rand and 
Logerwell 2011, Divine et al. 2015). The low likelihood of an oil spill 
large enough to affect walrus prey populations (see the section titled 
Risk Assessment of Potential Effects Upon Polar Bears from a Large Oil 
Spill in the Beaufort Sea) combined with the low density of walruses 
that feed on benthic invertebrates in this region during open-water 
season indicates that Industry activities will likely have limited 
effects on walruses through impacted prey species.
    The effects of Industry activity upon polar bear prey, primarily 
ringed seals and bearded seals, will be similar to that of effects upon 
walruses and primarily through noise disturbance or exposure

[[Page 43013]]

to an oil spill. Seals respond to vessel noise and potentially other 
Industry activities. Some seals exhibited a flush response, entering 
water when previously hauled out on ice, when noticing an icebreaker 
vessel that ranged from 100 m to 800 m away from the seal (Lomac-
MacNair et al. 2019). This disturbance response in addition to other 
behavioral responses could extend to other Industry vessels and 
activities, such as dredging (Todd et al. 2015). Sounds from Industry 
activity are probably audible to ringed seals and harbor seals at 
distances up to approximately 1.5 km in the water and approximately 5 
km in the air (Blackwell et al. 2004). Disturbance from Industry 
activity may cause seals to avoid important habitat areas, such as 
pupping lairs or haulouts, and to abandon breathing holes near Industry 
activity. However, these disturbances appear to have minor, short-term, 
and temporary effects (NMFS 2013).
    Consumption of oiled seals may impact polar bears through their 
exposure to oil spills during Industry activity (see Evaluation of 
Effects on Oil Spills on Pacific Walruses and Polar Bears). Ingestion 
of oiled seals would cause polar bears to ingest oil and inhale oil 
fumes, which can cause tissue and organ damage for polar bears 
(Engelhardt 1983). If polar bear fur were to become oiled during 
ingestion of oiled seals, this may lead to thermoregulation issues, 
increased metabolic activity, and further ingestion of oil during 
grooming (Engelhardt 1983). Ringed seals that have been exposed to oil 
or ingested oiled prey can accumulate hydrocarbons in their blubber and 
liver (Engelhardt 1983). These increased levels of hydrocarbons may 
affect polar bears even if seals are not oiled during ingestion. Polar 
bears could be impacted by reduced seal availability, displacement of 
seals in response to Industry activity, increased energy demands to 
hunt for displaced seals, and increased dependency on limited 
alternative prey sources, such as scavenging on bowhead whale carcasses 
harvested during subsistence hunts. If seal availability were to 
decrease, then the survival of polar bears may be drastically affected 
(Fahd et al. 2021). However, apart from a large-scale illegal oil 
spill, impacts from Industry activity on seals are anticipated to be 
minor and short-term, and these impacts are unlikely to substantially 
reduce the availability of seals as a prey source for polar bears. The 
risk of large-scale oil spills is discussed in Risk Assessment of 
Potential Effects upon Polar Bears from a Large Oil Spill in the 
Beaufort Sea.

Evaluation of Effects of Specified Activities on Pacific Walruses, 
Polar Bears, and Prey Species

Definitions of Incidental Take Under the Marine Mammal Protection Act

    Below we provide definitions of three potential types of take of 
Pacific walruses or polar bears. The Service does not anticipate and is 
not authorizing lethal take or Level A harassment as a part of the 
rule; 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 or Pacific walruses. In the most serious interactions, 
human actions can result in mortality of polar bears or Pacific 
walruses. 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). Incidental lethal take could result from human 
activity such as a vehicle collision or collapse of a den if it were 
run over by a vehicle. Unintentional disturbance of a female 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 own. Either scenario may result in 
the incidental lethal take of the cubs. Incidental lethal take of 
Pacific walrus could occur if the animal were directly struck by a 
vessel, or trampled by other walruses in a human-caused stampede.
Level A Harassment
    Human activity may result in the injury of polar bears or Pacific 
walruses. 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. 
Take by Level A harassment can be caused by numerous actions such as 
creating an annoyance that separates mothers from dependent cub(s)/
calves (Amstrup 2003), results in polar bear mothers leaving the den 
early (Amstrup and Gardner 1994, Rode et al. 2018b), or interrupts the 
nursing or resting of cubs/calves. For this ITR, we have also 
distinguished between non-serious and serious Level A harassment. 
Serious Level A harassment is defined here as an injury that is likely 
to result in mortality.
    Level A harassment to bears on the surface is extremely rare within 
the ITR region. From 2012 through 2018, one instance of Level A 
harassment occurred within the ITR region associated with defense of 
human life while engaged in non-Industry activity. No Level A 
harassment to Pacific walruses has been reported in the Beaufort Sea 
ITR region. Given this information, the Service does not estimate Level 
A harassment to polar bears or Pacific walruses will result from the 
activities specified in AOGA's Request. Nor has Industry anticipated or 
requested authorization for such take in their Request for ITRs.
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 behaviors or activities, 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 meet the criteria for take by Level B 
harassment under the MMPA. Reactions that indicate take by Level B 
harassment of polar bears in response to human activity 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;
     Ceasing to nurse or rest (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 family group 
from the den site.
    This list is not meant to encompass all possible behaviors; other 
behavioral responses may equate to take by Level B harassment. 
Relatively minor changes in behavior such as increased vigilance or a 
short-term change in direction of

[[Page 43014]]

travel are not likely to disrupt biologically important behavioral 
patterns, and the Service does not view such minor changes in behavior 
as resulting in a take by Level B harassment. It is also important to 
note that depending on the duration, frequency, or severity of the 
above-described behaviors, such responses could constitute take by 
Level A harassment (e.g., repeatedly disrupting a polar bear versus a 
single interruption).

Evaluation of Take

    The general approach for quantifying take in this ITR was as 
follows: (1) Determine the number of animals in the project area; (2) 
assess the likelihood, nature, and degree of exposure of these animals 
to project-relative activities; (3) evaluate these animals' probable 
responses; and (4) calculate how many of these responses constitute 
take. Our evaluation of take included quantifying the probability of 
either lethal take or Level A harassment (potential injury) and 
quantifying the number of responses that met the criteria for Level B 
harassment (potential disruption of a biologically significant 
behavioral pattern), factoring in the degree to which effective 
mitigation measures that may be applied will reduce the amount or 
consequences of take. To better account for differences in how various 
aspects of the project could impact polar bears, we performed separate 
take estimates for Surface-Level Impacts, Aircraft Activities, Impacts 
to Denning Bears, and Maritime Activities. These analyses are described 
in more detail in the subsections below. Once each of these categories 
of take were quantified, the next steps were to: (5) Determine whether 
the total take will be of a small number relative to the size of the 
species or stock; and (6) determine whether the total take will have a 
negligible impact on the species or stock, both of which are 
determinations required under the MMPA.

Pacific Walrus: All Interactions

    With the low occurrence of walruses in the Beaufort Sea and the 
adoption of the mitigation measures required by this ITR, the Service 
concludes that the only anticipated effects from Industry noise in the 
Beaufort Sea would be short-term behavioral alterations of small 
numbers of walruses. All walrus encounters within the ITR geographic 
area in the past 10 years have been of solitary walruses or groups of 
two. The closest sighting of a grouping larger than two was outside the 
ITR area in 2013. The vessel encountered a group of 15 walrus. Thus, 
while it is highly unlikely that a group of walrus will be encountered 
during the proposed activities, we estimate that no more than one group 
of 15 Pacific walruses will be taken as a result of Level B harassment 
each year during the ITR period.

Polar Bear: Surface Interactions

Encounter Rate
    The most comprehensive dataset of human-polar bear encounters along 
the coast of Alaska consists of records of Industry encounters during 
activities on the North Slope submitted to the Service under existing 
and previous ITRs. This database is referred to as the ``LOA database'' 
because it aggregates data reported by the oil and gas industry to the 
Service pursuant to the terms and conditions of LOAs issued under 
current and previous incidental take regulations (50 CFR part 18, 
subpart J). We have used records in the LOA database in the period 
2014-2018, in conjunction with bear density projections for the entire 
coastline, to generate quantitative encounter rates in the project 
area. This 5-year period was used to provide metrics that reflected the 
most recent patterns of polar bear habitat use within the Beaufort Sea 
ITR region. Each encounter record includes the date and time of the 
encounter, a general description of the encounter, number of bears 
encountered, latitude and longitude, weather variables, and a take 
determination made by the Service. If latitude and longitude were not 
supplied in the initial report, we georeferenced the encounter using 
the location description and a map of North Slope infrastructure.
Spatially Partitioning the North Slope Into ``Coastal'' and ``Inland'' 
Zones
    The vast majority of SBS polar bear encounters along the Alaskan 
coast occur along the shore or immediately offshore (Atwood et al. 
2015, Wilson et al. 2017). Thus, encounter rates for inland operations 
should be significantly lower than those for offshore or coastal 
operations. To partition the North Slope into ``coastal'' and 
``inland'' zones, we calculated the distance to shore for all encounter 
records in the period 2014-2018 in the Service's LOA database using a 
shapefile of the coastline and the dist2Line function found in the R 
geosphere package (Hijmans 2019). Linked sightings of the same bear(s) 
were removed from the analysis, and individual records were created for 
each bear encountered. However, because we were able to identify and 
remove only repeated sightings that were designated as linked within 
the database, it is likely that some repeated encounters of the same 
bear remained in our analysis. From 2014 through 2018, of the 1,713 
bears encountered, 1,140 (66.5 percent) were offshore. While these 
bears were encountered offshore, the encounters were reported by 
onshore or island operations (i.e., docks, drilling and production 
islands, or causeways). We examined the distribution of bears that were 
onshore and up to 10 km (6.2 mi) inland to determine the distance at 
which encounters sharply decreased (Figure 2).
BILLING CODE 4333-15-P

[[Page 43015]]

[GRAPHIC] [TIFF OMITTED] TR05AU21.001

    The histogram illustrates a steep decline in human-polar bear 
encounters at 2 km (1.2 mi) from shore. Using this data, we divided the 
North Slope into the ``coastal zone,'' which includes offshore 
operations and up to 2 km (1.2 mi) inland, and the ``inland zone,'' 
which includes operations more than 2 km (1.2 mi) inland.
Dividing the Year Into Seasons
    As we described in our review of polar bear biology above, the 
majority of polar bears spend the winter months on the sea ice, leading 
to few polar bear encounters on the shore during this season. Many of 
the proposed activities are also seasonal, and only occur either in the 
winter or summer months. In order to develop an accurate estimate of 
the number of polar bear encounters that may result from the proposed 
activities, we divided the year into seasons of high bear activity and 
low bear activity using the Service's LOA database. Below is a 
histogram of all bear encounters from 2014 through 2018 by day of the 
year (Julian date). Two clear seasons of polar bear encounters can be 
seen: an ``open-water season'' that begins in mid-July and ends in mid-
November, and an ``ice season'' that begins in mid-November and ends in 
mid-July. The 200th and 315th days of the year were used to delineate 
these seasons when calculating encounter rates (Figure 3).

[[Page 43016]]

[GRAPHIC] [TIFF OMITTED] TR05AU21.002

North Slope Encounter Rates
    Encounter rates in bears/season/km\2\ were calculated using a 
subset of the Industry encounter records maintained in the Service's 
LOA database. The following formula was used to calculate encounter 
rate (Equation 1):
[GRAPHIC] [TIFF OMITTED] TR05AU21.003

    The subset consisted of encounters in areas that were constantly 
occupied year-round to prevent artificially inflating the denominator 
of the equation and negatively biasing the encounter rate. To identify 
constantly occupied North Slope locations, we gathered data from a 
number of sources. We used past LOA requests to find descriptions of 
projects that occurred anywhere within 2014-2018 and the final LOA 
reports to determine the projects that proceeded as planned and those 
that were never completed. Finally, we relied upon the institutional 
knowledge of our staff, who have worked with operators and inspected 
facilities on the North Slope. To determine the area around industrial 
facilities in which a polar bear can be seen and reported, we queried 
the Service LOA database for records that included the distance to an 
encountered polar bear. It is important to note that these values may 
represent the closest distance a bear came to the observer or the 
distance at initial contact. Therefore, in some cases, the bear may 
have been initially encountered farther than the distance recorded. The 
histogram of these values shows a drop in the distance at which a polar 
bear is encountered at roughly 1.6 km (1 mi) (Figure 4).

[[Page 43017]]

[GRAPHIC] [TIFF OMITTED] TR05AU21.004

BILLING CODE 4333-15-C
    Using this information, we buffered the 24-hour occupancy locations 
listed above by 1.6 km (1 mi) and calculated an overall search area for 
both the coastal and inland zones. The coastal and inland occupancy 
buffer shapefiles were then used to select encounter records that were 
associated with 24-hour occupancy locations, resulting in the number of 
bears encountered per zone. These numbers were then separated into 
open-water and ice seasons (Table 2).

   Table 2--Summary of Encounters of Polar Bears on the North Slope of
   Alaska in the Period 2014-2018 Within 1.6 km (1 mi) of the 24-hour
 Occupancy Locations and Subsequent Encounter Rates for Coastal (a) and
                            Inland (b) Zones
------------------------------------------------------------------------
                                        Ice season     Open-water season
               Year                     encounters         encounters
------------------------------------------------------------------------
                   (A) Coastal Zone (Area = 133 km\2\)
------------------------------------------------------------------------
2014..............................                  2                193
2015..............................                  8                 49
2016..............................                  4                227
2017..............................                  7                313
2018..............................                 13                205
Average...........................                6.8              197.4
                                   -------------------------------------
Seasonal Encounter Rate...........   0.05 bears/km\2\   1.48 bears/km\2\
------------------------------------------------------------------------
                   (B) Inland Zone (Area = 267 km\2\)
------------------------------------------------------------------------
2014..............................                  3                  3
2015..............................                  0                  0
2016..............................                  0                  2
2017..............................                  3                  0
2018..............................                  0                  2
Average...........................                1.2                1.4
                                   -------------------------------------
Seasonal Encounter Rate...........  0.004 bears/km\2\  0.005 bears/km\2\
------------------------------------------------------------------------


[[Page 43018]]

Harassment Rate
    The Level B harassment rate or the probability that an encountered 
bear will experience either incidental or intentional Level B 
harassment, was calculated using the 2014-2018 dataset from the LOA 
database. A binary logistic regression of harassment regressed upon 
distance to shore was not significant (p = 0.65), supporting the use of 
a single harassment rate for both the coastal and inland zones. 
However, a binary logistic regression of harassment regressed upon day 
of the year was significant. This significance held when encounters 
were binned into either ice or open-water seasons (p<0.0015).
    We subsequently estimated the harassment rate for each season with 
a Bayesian probit regression with season as a fixed effect (Hooten and 
Hefley 2019). Model parameters were estimated using 10,000 iterations 
of a Markov chain Monte Carlo algorithm composed of Gibbs updates 
implemented in R (R core team 2021, Hooten and Hefley 2019). We used 
Normal (0,1) priors, which are uninformative on the prior predictive 
scale (Hobbs and Hooten 2015), to generate the distribution of open-
water and ice-season marginal posterior predictive probabilities of 
harassment. The upper 99 percent quantile of each probability 
distribution can be interpreted as the upper limit of the potential 
harassment rate supported by our dataset (i.e., there is a 99 percent 
chance that given the data the harassment rate is lower than this 
value). We chose to use 99 percent quantiles of the probability 
distributions to account for any negative bias that has been introduced 
into the dataset through unobserved harassment or variability in the 
interpretation of polar bear behavioral reactions by multiple 
observers. The final harassment rates were 0.19 during the open-water 
season and 0.37 during the ice season (Figure 5).
[GRAPHIC] [TIFF OMITTED] TR05AU21.005

Impact Area
    As noted above, we have calculated encounter rates depending on the 
distance from shore and season and take rates depending on season. To 
properly assess the area of potential impact from the project 
activities, we must calculate the area affected by project activities 
to such a degree that harassment is possible. This is sometimes 
referred to as a zone or area of influence. Behavioral response rates 
of polar bears to disturbances are highly variable, and data to support 
the relationship between distance to bears and disturbance is limited. 
Dyck and Baydack (2004) found sex-based differences in the frequencies 
of vigilant bouts of polar bears in the presence of vehicles on the 
tundra. However, in their summary of polar bear behavioral response to 
ice-breaking vessels in the Chukchi Sea, Smultea et al. (2016) found no 
difference between reactions of males, females with cubs, or females 
without cubs. During the Service'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 supports the use of a 1.6 km (1.0 mi) impact area, as it 
will encompass the vast majority of polar bear harassment events.
Correction Factor
    While the locations that were used to calculate encounter rates are 
thought to have constant human occupancy, it is possible that bears may 
be in the

[[Page 43019]]

vicinity of industrial infrastructure and not be noticed by humans. 
These unnoticed bears may also experience Level B harassment. To 
determine whether our calculated encounter rate should be corrected for 
unnoticed bears, we compared our encounter rates to Wilson et al.'s 
(2017) weekly average polar bear estimates along the northern coast of 
Alaska and the South Beaufort Sea.
    Wilson et al.'s weekly average estimate of polar bears across the 
coast was informed by aerial surveys conducted by the Service in the 
period 2000-2014 and supplemented by daily counts of polar bears in 
three high-density barrier islands (Cross, Barter, and Cooper Islands). 
Using a Bayesian hierarchical model, the authors estimated 140 polar 
bears would be along the coastline each week between the months of 
August and October. These estimates were further partitioned into 10 
equally sized grids along the coast. Grids 4-7 overlap the SBS ITR 
area, and all three encompass several industrial facilities. Grid 6 was 
estimated to account for 25 percent of the weekly bear estimate (35 
bears); however, 25 percent of the bears in grid 6 were located on 
Cross Island. Grids 5 and 7 were estimated to contain seven bears each, 
weekly. Using raw aerial survey data, we calculated the number of bears 
per km of surveyed mainland and number of bears per km of surveyed 
barrier islands for each Service aerial survey from 2010 through 2014 
to determine the proportion of bears on barrier islands versus the 
mainland. On average, 1.7 percent, 7.2 percent, and 14 percent of bears 
were sighted on the mainland in grids 5, 6, and 7, respectively.
    While linked encounter records in the LOA database were removed in 
earlier formatting, it is possible that a single bear may be the focus 
of multiple encounter records, particularly if the bear moves between 
facilities operated by different entities. To minimize repeated 
sightings, we designated a single industrial infrastructure location in 
each grid: Oliktok Point in grid 5, West Beach in grid 6, and Point 
Thomson's CP in grid 7. These locations were determined in earlier 
analyses to have constant 24-occupancy; thus, if a polar bear were 
within the viewing area of these facilities, it must be reported as a 
condition of each entity's LOA.
    Polygons of each facility were buffered by 1.6 km (1 mi) to account 
for the industrial viewing area (see above), and then clipped by a 400-
m (0.25-mi) buffer around the shoreline to account for the area in 
which observers were able to reliably detect polar bears in the 
Service's aerial surveys (i.e., the specific area to which the Wilson 
et al.'s model predictions applied). Industrial encounters within this 
area were used to generate the average weekly number of polar bears 
from August through October. Finally, we divided these numbers by area 
to generate average weekly bears/km\2\ and multiplied this number by 
the total coastal Service aerial survey area. The results are 
summarized in the table below (Table 3).

    Table 3--Comparison of Polar Bear Encounters to Number of Polar Bears Projected by Wilson et al. 2017 at
                      Designated Point Locations on the Coast of the North Slope of Alaska
----------------------------------------------------------------------------------------------------------------
                                                                      Grid 5          Grid 6          Grid 7
----------------------------------------------------------------------------------------------------------------
Total coastline viewing area (km\2\)............................              34              45            33.4
Industry viewing area (km\2\)...................................            0.31            0.49             1.0
Proportion of coastline area viewed by point location...........           0.009           0.011           0.030
Average number of bears encountered August-October at point                  3.2             4.6            28.8
 location.......................................................
Number of weeks in analysis.....................................              13              13              13
Average weekly number of bears reported at point location.......           0.246           0.354           2.215
Average weekly number of bears projected in grid*...............               7              26               7
Average weekly number of bears projected for point location.....           0.064           0.283           0.210
----------------------------------------------------------------------------------------------------------------

    These comparisons show a greater number of industrial sightings 
than would be estimated by the Wilson et al. 2017 model. There are 
several potential explanations for higher industrial encounters than 
projected by model results. Polar bears may be attracted to industrial 
infrastructure, the encounters documented may be multiple sightings of 
the same bear, or specifically for the Point Thomson location, higher 
numbers of polar bears may be travelling past the pad to the Kaktovik 
whale carcass piles. However, because the number of polar bears 
estimated within the point locations is lower than the average number 
of industrial sightings, these findings cannot be used to create a 
correction factor for industrial encounter rate. To date, the data 
needed to create such a correction factor (i.e., spatially explicit 
polar bear densities across the North Slope) have not been generated.
Estimated Harassment
    We estimated Level B harassment using the spatio-temporally 
specific encounter rates and temporally specific take rates derived 
above in conjunction with AOGA supplied spatially and temporally 
specific data. Table 4 provides the definition for each variable used 
in the take formulas.

[[Page 43020]]

[GRAPHIC] [TIFF OMITTED] TR05AU21.006

    The variables defined above were used in a series of formulas to 
ultimately estimate the total harassment from surface-level 
interactions. Encounter rates were originally calculated as bears 
encountered per square kilometer per season (see North Slope Encounter 
Rates above). As a part of their Request, AOGA provided the Service 
with digital geospatial files that included the maximum expected human 
occupancy (i.e., rate of occupancy (ro)) for each individual 
structure (e.g., each road, pipeline, well pad, etc.) of their proposed 
activities for each month of the ITR period. Months were averaged to 
create open-water and ice-season occupancy rates. For example, 
occupancy rates for July 2022, August 2022, September 2022, October 
2022, and November 2022 were averaged to calculate the occupancy rate 
for a given structure during the open-water 2022 season. Using the 
buffer tool in ArcGIS, we created a spatial file of a 1.6-km (1-mi) 
buffer around all industrial structures. 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 spatial footprint of 
the 100 percent occupancy buffers from the dataset 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 shapefiles to 
determine the coastal areas of impact (ac) and inland areas 
of impact (ai) for each activity category. We then used 
spatial files of the coastal and inland zones to determine the area in 
coastal verse inland zones for each occupancy percentage. This process 
was repeated for each season from open-water 2021 to open-water 2026.
    Impact areas were multiplied by the appropriate encounter rate to 
obtain the number of bears expected to be encountered in an area of 
interest per season (Bes). The equation below (Equation 3) 
provides an example of the calculation of bears encountered in the ice 
season for an area of interest in the coastal zone.
[GRAPHIC] [TIFF OMITTED] TR05AU21.007

    To generate the number of estimated Level B harassments for each 
area of interest, we multiplied the number of 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 4).
[GRAPHIC] [TIFF OMITTED] TR05AU21.008


[[Page 43021]]


    The estimated harassment values for the open-water 2021 and open-
water 2026 seasons were adjusted to account for incomplete seasons as 
the regulations will be effective for only 85 and 15 percent of the 
open-water 2021 and 2026 seasons, respectively.

Aircraft Impact to Surface Bears

    Polar bears in the project area will likely be exposed to the 
visual and auditory stimulation associated with AOGA's fixed-wing and 
helicopter flight plans; however, these impacts are likely to be 
minimal and not long-lasting to surface bears. Flyovers may cause 
disruptions in the polar bear's normal behavioral patterns, thereby 
resulting in incidental Level B harassment. Sudden changes in 
direction, elevation, and movement may also increase the level of noise 
produced from the helicopter, especially at lower altitudes. This 
increased level of noise could disturb polar bears in the area to an 
extent that their behavioral patterns are disrupted and Level B 
harassment occurs. Mitigation measures, such as minimum flight 
altitudes over polar bears and restrictions on sudden changes to 
helicopter movements and direction, will be required to reduce the 
likelihood that polar bears are disturbed by aircraft. Once mitigated, 
such disturbances are expected to have no more than short-term, 
temporary, and minor impacts on individual bears.
Estimating Harassment Rates of Aircraft Activities
    To predict how polar bears will respond to fixed-wing and 
helicopter overflights during North Slope oil and gas activities, we 
first examined existing data on the behavioral responses of polar bears 
during aircraft surveys conducted by the Service and U.S. Geological 
Survey (USGS) between August and October during most years from 2000 to 
2014 (Wilson et al. 2017, Atwood et al. 2015, and Schliebe et al. 
2008). Behavioral responses due to sight and sound of the aircraft have 
both been incorporated into this analysis as there was no ability to 
differentiate between the two response sources during aircraft survey 
observations. Aircraft types used for surveys during the study included 
a fixed-wing Aero-Commander from 2000 to 2004, a R-44 helicopter from 
2012 to 2014, and an A-Star helicopter for a portion of the 2013 
surveys. During surveys, all aircraft flew at an altitude of 
approximately 90 m (295 ft) and at a speed of 150 to 205 km per hour 
(km/h) or 93 to 127 mi per hour (mi/h). Reactions indicating possible 
incidental Level B harassment were recorded when a polar bear was 
observed running from the aircraft or began to run or swim in response 
to the aircraft. Of 951 polar bears observed during coastal aerial 
surveys, 162 showed these reactions, indicating that the percentage of 
Level B harassments during these low-altitude coastal survey flights 
was as high as 17 percent.
    Detailed data on the behavioral responses of polar bears to the 
aircraft and the distance from the aircraft each polar bear was 
observed were available for only the flights conducted between 2000 to 
2004 (n = 581 bears). The Aero-Commander 690 was used during this 
period. The horizontal detection distance from the flight line was 
recorded for all groups of bears detected. To determine if there was an 
effect of distance on the probability of a response indicative of 
potential Level B harassment, we modeled the binary behavioral response 
by groups of bears to the aircraft with Bayesian probit regression 
(Hooten and Hefley 2019). We restricted the data to those groups 
observed less than 10 km from the aircraft, which is the maximum 
distance at which behavioral responses were likely to be reliably 
recorded.
    In nearly all cases when more than one bear was encountered, every 
member of the group exhibited the same response, so we treated the 
group as the sampling unit, yielding a sample size of 346 groups. Of 
those, 63 exhibited behavioral responses. Model parameters were 
estimated using 10,000 iterations of a Markov chain Monte Carlo 
algorithm composed of Gibbs updates implemented in R (R core team 2021, 
Hooten and Hefley 2019). Normal (0,1) priors, which are uninformative 
on the prior predictive scale (Hobbs and Hooten 2015), were placed on 
model parameters. Distance to bear as well as squared distance (to 
account for possible non-linear decay of probability with distance) 
were included as covariates. However, the 95 percent confidence 
intervals for the estimated coefficients overlapped zero suggesting no 
significant effect of distance on polar bears' behavioral responses. 
While it is likely that bears do respond differently to aircraft at 
different distances, the data available is heavily biased towards very 
short distances because the coastal surveys are designed to observe 
bears immediately along the coast. We were thus unable to detect any 
effect of distance. Therefore, to estimate a single rate of harassment, 
we fit an intercept-only model and used the distribution of the 
marginal posterior predictive probability to compute a point estimate.
    Because the data from the coastal surveys were not systematically 
collected to study polar bear behavioral responses to aircraft, the 
data likely bias the probability of behavioral response low. We, 
therefore, chose the upper 99th percentile of the distribution as our 
point estimate of the probability of potential harassment. This equated 
to a harassment rate of 0.23. Because we were not able to detect an 
effect of distance, we could not correlate behavioral responses with 
profiles of sound pressure levels for the Aero-Commander (the aircraft 
used to collect the survey data). Therefore, we could also not use that 
relationship to extrapolate behavioral responses to sound profiles for 
takeoffs and landings nor sound profiles of other aircraft. 
Accordingly, we applied the single harassment rate to all portions of 
all aircraft flight paths.
General Approach to Estimating Harassment for Aircraft Activities
    Aircraft information was determined using details provided in 
AOGA's Request, including flight paths, flight take-offs and landings, 
altitudes, and aircraft type. More information on the altitudes of 
future flights can be found in the Request. If no location or frequency 
information was provided, flight paths were approximated based on the 
information provided. Of the flight paths that were described clearly 
or were addressed through assumptions, we marked the approximate flight 
path start and stop points using ArcGIS Pro (version 2.4.3), and the 
paths were drawn. For flights traveling between two airstrips, the 
paths were reviewed and duplicated as closely as possible to the flight 
logs obtained from www.FlightAware.com (FlightAware), a website that 
maintains flight logs in the public domain. For flight paths where 
airstrip information was not available, a direct route was assumed. 
Activities such as pipeline inspections followed a route along the 
pipeline with the assumption the flight returned along the same route 
unless a more direct path was available.
    Flight paths were broken up into segments for landing, take-off, 
and traveling to account for the length of time the aircraft may be 
impacting an area based on flight speed. The distance considered the 
``landing'' area is based on approximately 4.83 km (3 mi) per 305 m 
(1,000 ft) of altitude descent speed. For all flight paths at or 
exceeding an altitude of 152.4 m (500 ft), the ``take-off'' area was 
marked as 2.41 km (1.5 mi) derived from flight logs found through 
FlightAware, which suggested that ascent to maximum flight altitude 
took approximately half the time of the average descent. The remainder 
of the flight path that

[[Page 43022]]

stretches between two air strips was considered the ``traveling'' area. 
We then applied the exposure area of 1,610 m (1 mi) along the flight 
paths. The data used to estimate the probability of Level B harassments 
due to aircraft (see section Estimating Harassment Rates of Aircraft 
Activities) suggested 99% of groups of bears were observed within 1.6 
km of the aircraft.
    We then differentiated the coastal and inland zones. The coastal 
zone was the area offshore and within 2 km (1.2 mi) of the coastline 
(see section Spatially Partitioning the North Slope into ``coastal'' 
and ``inland'' zones), and the inland zone was anything greater than 2 
km (1.2 mi) from the coastline. We calculated the areas in square 
kilometers for the exposure area within the coastal zone and the inland 
zone for all take-offs, landings, and traveling areas. For flights that 
involve an inland and a coastal airstrip, we considered landings to 
occur at airstrips within the coastal zone. Seasonal encounter rates 
developed for both the coastal and inland zones (see section Search 
Effort Buffer) were applied to the appropriate segments of each flight 
path.
    Surface encounter rates were calculated based on the number of 
bears per season (see section Search Effort Buffer). To apply these 
rates to aircraft activities, we needed to calculate a proportion of 
the season in which aircraft were flown. However, the assumption 
involved in using a seasonal proportion is that the area is impacted 
for an entire day (i.e., for 24 hours). Therefore, to prevent 
estimating impacts along the flight path over periods of time where 
aircraft are not present, we calculated a proportion of the day the 
area will be impacted by aircraft activities for each season (Table 5).
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[GRAPHIC] [TIFF OMITTED] TR05AU21.009


[[Page 43023]]


    The number of times each flight path was flown (i.e., flight 
frequency) was determined from the Request. We used the description 
combined with the approximate number of weeks and months within the 
open-water season and the ice season to determine the total number of 
flights per season for each year (f). We then used flight frequency and 
number of days per season (ds) to calculate the seasonal 
proportion of flights (Sp; Equation 6).
[GRAPHIC] [TIFF OMITTED] TR05AU21.010

    After we determined the seasonal proportion of flights, we 
estimated the amount of time an aircraft would be impacting the 
landing/take-off areas within a day (tLT). Assuming an aircraft is not 
landing at the same time another is taking off from the same airstrip, 
we estimated the amount of time an aircraft would be present within the 
landing or take-off zone would be tLT = 10 minutes. We then calculated 
how many minutes within a day an aircraft would be impacting an area 
and divided by the number of minutes within a 24-hour period (1,440 
minutes). This determined the proportion of the day in which a landing/
take-off area is impacted by an aircraft for each season 
(Dp(LT); Equation 7).
[GRAPHIC] [TIFF OMITTED] TR05AU21.011

    To estimate the amount of time an aircraft would be impacting the 
travel areas (tTR, we calculated the minimum amount of time it would 
take for an aircraft to travel the maximum exposure area at any given 
time, 3.22 km (2.00 mi). We made this estimate using average aircraft 
speeds at altitudes less than 305 m (1,000 ft) to account for slower 
flights at lower altitudes, such as summer cleanup activities and 
determined it would take approximately 1.5 minutes. We then determined 
how many 3.22-km (2-mi) segments are present along each traveling path 
(x). We determined the total number of minutes an aircraft would be 
impacting any 3.22-km (2-mi) segment along the travel area in a day and 
divided by the number of minutes in a 24-hour period. This calculation 
determined the proportion of the day in which an aircraft would impact 
an area while traveling during each season 
(Dp(TR); Equation 8).
[GRAPHIC] [TIFF OMITTED] TR05AU21.012

    We then used observations of behavioral reactions from aerial 
surveys (see section Estimating Harassment Rates of Aircraft 
Activities) to determine the appropriate harassment rate in the 
exposure area (1,610 m (1 mi) from the center of the flight line; see 
above in this section). The harassment rate areas were then calculated 
separately for the landing and take-off areas along each flight path as 
well as the traveling area for all flights with altitudes at or below 
457.2 m (1,500 ft).
    To estimate number of polar bears harassed due to aircraft 
activities, we first calculated the number of bears encountered (Bes) 
for the landing/take-off and traveling sections using both coastal (eci 
or co) and inland (eii or io) encounter rates 
within the coastal (ac) and inland (ai) exposure areas (Equation 9).
[GRAPHIC] [TIFF OMITTED] TR05AU21.013


[[Page 43024]]


    Using the calculated number of coastal and inland bears encountered 
for each season, we applied the daily seasonal proportion for both 
landings/take-offs and traveling areas to determine the daily number of 
bears impacted due to aircraft activities (Bi). We then applied the 
aircraft harassment rate (ta) associated with the exposure area (see 
section Estimating Harassment Rates of Aircraft Activities), resulting 
in a number of bears harassed during each season (Bt; Equation 10). 
Harassment associated with AIR surveys was analyzed separately.
[GRAPHIC] [TIFF OMITTED] TR05AU21.014

BILLING CODE 4333-15-C

Analysis Approach for Estimating Harassment During Aerial Infrared 
Surveys

    Typically, during every ice season Industry conducts polar bear den 
surveys using AIR. Although the target for these surveys is polar bear 
dens, bears on the surface can be impacted by the overflights. These 
surveys are not conducted along specific flight paths and generally 
overlap previously flown areas within the same trip. Therefore, the 
harassment estimates for surface bears during AIR surveys were 
estimated using a different methodology.
    Rather than estimate potential flight paths, we used the maximum 
amount of flight time that is likely to occur for AIR surveys during 
each year. The period of AIR surveys lasts November 25th to January 
15th (52 days), and we estimated a maximum of 6 hours of flight time 
per day, resulting in a total of 312 flight hours per year. To 
determine the amount of time AIR flights are likely to survey coastal 
and inland zones, we found the area where industry activities and 
denning habitat overlap and buffered by 1.6 km (1 mi). We then split 
the buffered denning habitat by zone and determined the proportion of 
coastal and inland denning habitat. Using this proportion, we estimated 
the number of flight hours spent within each zone and determined the 
proportion of the ice season in which AIR surveys were impacting the 
survey areas (see General Approach to Estimating Harassment for 
Aircraft Activities). We then estimated the aircraft footprint to 
determine the area that would be impacted at any given time as well as 
the area accounting for two take-offs and two landings. Using the 
seasonal bear encounter rates for the appropriate zones multiplied by 
the area impacted and the proportion of the season AIR flights were 
flown, we determined the number of bears encountered. We then applied 
the aircraft harassment rate to the number of bears encountered per 
zone to determine number of bears harassed.
Estimated Harassment From Aircraft Activities
    Using the approach described in General Approach to Estimating 
Harassment for Aircraft Activities and Analysis Approach for Estimating 
Harassment during Aerial Infrared Surveys, we estimated the total 
number of bears expected to be harassed by the aircraft activities 
included in the analyses during the Beaufort Sea ITR period of 2021-
2026 (Table 6).

  Table 6--Estimated Level B Harassment of Polar Bears on the North Slope of Alaska by Year as a Result of Aircraft Operations During the 2021-2026 ITR
                                                                         Period
                                            [Average estimated polar bear harassments per year = 1.09 bears]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                        21-22            22-23            23-24            24-25            25-26              26             Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
Est. Harassment..................            0.89             0.95             0.95             1.09             1.09             0.15             5.45
--------------------------------------------------------------------------------------------------------------------------------------------------------

Methods for Modeling the Effects of Den Disturbance

Case Studies Analysis
    To assess the likelihood and degree of exposure and predict 
probable responses of denning polar bears to activities proposed in the 
AOGA Request, we characterized, evaluated, and prioritized a series of 
rules and definitions towards a predictive model based on knowledge of 
published and unpublished information on denning ecology, behavior, and 
cub survival. Contributing information came from literature searches in 
several major research databases and data compiled from polar bear 
observations submitted by the oil and gas Industry. We considered all 
available scientific and observational data we could find on polar bear 
denning behavior and effects of disturbance.
    From these sources, we identified 57 case studies representing 
instances where polar bears at a maternal den may have been exposed to 
human activities. For each den, we considered the four denning periods 
separately, and for each period, determined whether adequate 
information existed to document whether (1) the human activity met our 
definition of an exposure and (2) the response of the bear(s) could be 
classified according to our rules and definitions. From these 57 dens, 
80 denning period-specific events met these criteria. For each event, 
we classified the type and frequency (i.e., discrete or repeated) of 
the exposure, the response of the bear(s), and the level of take 
associated with that response. From this information, we calculated the 
probability that a discrete or repeated exposure would result in each 
possible level of take during each denning period, which informed the 
probabilities for outcomes in the simulation model (Table 7).

[[Page 43025]]



  Table 7--Probability That a Discrete or Repeated Exposure Elicited a Response by Denning Polar Bears That Would Result in Level B Harassment, Level A
                                          Harassment (Including Serious and Non-Serious Injury), or Lethal Take
 [Level B harassment was applicable to both adults and cubs, if present; Level A harassment and lethal take were applicable to cubs only. Probabilities
  were calculated from the analysis of 57 case studies of polar bear responses to human activity. Cells with NAs indicate these types of take were not
                                                       possible during the given denning period.]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                            Non-serious    Serious Level
             Exposure type                            Period                   None           Level B         Level A            A            Lethal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Discrete...............................  Den Establishment..............           0.400           0.600              NA              NA              NA
                                         Early Denning..................           1.000           0.000              NA              NA           0.000
                                         Late Denning...................           0.091           0.000              NA           0.909           0.000
                                         Post-emergence.................           0.000           0.000           0.750              NA           0.250
Repeated...............................  Den Establishment..............           1.000           0.000              NA              NA              NA
                                         Early Denning..................           0.800           0.000              NA              NA           0.200
                                         Late Denning...................           0.708           0.000              NA           0.292           0.000
                                         Post-emergence.................           0.000           0.267           0.733              NA           0.000
--------------------------------------------------------------------------------------------------------------------------------------------------------

Case Study Analysis Definitions
    Below, we provide definitions for terms used in this analysis, a 
general overview of denning chronology and periods (details are 
provided in the Potential Effects to Pacific Walrus, Polar Bears and 
Prey Species: Effects on denning bears), and the rules established for 
using the case studies to inform the model.

Exposure and Response Definitions

    Exposure: Any human activity within 1.6 km (1 mi) of a polar bear 
den site. In the case of aircraft, an overflight within 457 m (0.3 mi) 
above ground level.
    Discrete exposure: An exposure that occurs only once and of short 
duration (<30 minutes). It can also be a short-duration exposure that 
happens repeatedly but that is separated by sufficient time that 
exposures can be treated as independent (e.g., aerial pipeline surveys 
that occur weekly).
    Repeated exposure: An exposure that occurs more than once within a 
time period where exposures cannot be considered independent or an 
exposure that occurs due to continuous activity during a period of time 
(e.g., traffic along a road, or daily visits to a well pad).
    Response probability: The probability that an exposure resulted in 
a response by denning polar bears.
    We categorized each exposure into categories based on polar bear 
response:
     No response: No observed or presumed behavioral or 
physiological response to an exposure.
     Likely physiological response: An alteration in the normal 
physiological function of a polar bear (e.g., elevated heart rate or 
stress hormone levels) that is typically unobservable but is likely to 
occur in response to an exposure.
     Behavioral response: A change in behavior in response to 
an exposure. Behavioral responses can range from biologically 
insignificant (e.g., a resting bear raising its head in response to a 
vehicle driving along a road) to substantial (e.g., cub abandonment) 
and concomitant levels of take vary accordingly.

Timing Definitions

    Entrance date: The date a female first enters a maternal den after 
excavation is complete.
    Emergence date: The date a maternal den is first opened and a bear 
is exposed directly to external conditions. Although a bear may exit 
the den completely at emergence, we considered even partial-body exits 
(e.g., only a bear's head protruding above the surface of the snow) to 
represent emergence in order to maintain consistency with dates derived 
from temperature sensors on collared bears (e.g., Rode et al. 2018b). 
For dens located near regularly occurring human activity, we considered 
the first day a bear was observed near a den to be the emergence date 
unless other data were available to inform emergence dates (e.g., GPS 
collar data).
    Departure date: The date when bears leave the den site to return to 
the sea ice. If a bear leaves the den site after a disturbance but 
later returns, we considered the initial movement to be the departure 
date.

Definition of Various Denning Periods

    Den establishment period: Period of time between the start of 
maternal den excavation and the birth of cubs. Unless evidence 
indicates otherwise, all dens that are excavated by adult females in 
the fall or winter are presumed to be maternal dens. In the absence of 
other information, this period is defined as denning activity prior to 
December 1 (i.e., estimated earliest date cubs are likely present in 
dens (Derocher et al. 1992, Van de Velde et al. 2003)).
    Early denning period: Period of time from the birth of cubs until 
they reach 60 days of age and are capable of surviving outside the den. 
In the absence of other information, this period is defined as any 
denning activity occurring between December 1 and February 13 (i.e., 60 
days after 15 December, the estimated average date of cub birth; Van de 
Velde et al. 2003, Messier et al. 1994).
    Late denning period: Period of time between when cubs reach 60 days 
of age and den emergence. In the absence of other information, this 
period is defined as any denning activity occurring between 14 February 
and den emergence.
    Post-emergence period: Period of time between den emergence and den 
site departure. We considered a ``normal'' duration at the den site 
between emergence and departure to be greater than or equal to 8 days 
and classified departures that occurred post emergence ``early'' if 
they occurred less than 8 days after emergence.

Descriptions of Potential Outcomes

    Cub abandonment: Occurs when a female leaves all or part of her 
litter, either in the den or on the surface, at any stage of the 
denning process. We classified events where a female left her cubs but 
later returned (or was returned by humans) as cub abandonment.
    Early emergence: Den emergence that occurs as the result of an 
exposure (see `Rules' below).
    Early departure: Departure from the den site post-emergence that 
occurs as the result of an exposure (see `Rules' below).
Predictive Model Rules for Determining Den Outcomes and Assigning Take
     We considered any exposure in a 24-hour period that did 
not result in a Level A harassment or lethal take to potentially be a 
Level B harassment take

[[Page 43026]]

if a behavioral response was observed. However, multiple exposures do 
not result in multiple Level B harassment takes unless the exposures 
occurred in two different denning periods.
     If comprehensive dates of specific exposures are not 
available and daily exposures were possible (e.g., the den was located 
within 1.6 km [1 mi] of an ice road), we assumed exposures occurred 
daily.
     In the event of an exposure that resulted in a disturbance 
to denning bears, take was assigned for each bear (i.e., female and 
each cub) associated with that den. Whereas assigned take for cubs 
could range from Level B harassment to lethal take, for adult females 
only Level B harassment was possible.
     In the absence of additional information, we assumed dens 
did not contain cubs prior to December 1 but did contain cubs on or 
after December 1.
     If an exposure occurred and the adult female subsequently 
abandoned her cubs, we assigned a lethal take for each cub.
     If an exposure occurred during the early denning period 
and bears emerged from the den before cubs reached 60 days of age, we 
assigned a lethal take for each cub. In the absence of information 
about cub age, a den emergence that occurred between December 1 and 
February 13 was considered to be an early emergence and resulted in a 
lethal take of each cub.
     If an exposure occurred during the late denning period 
(i.e., after cubs reached 60 days of age) and bears emerged from the 
den before their intended (i.e., undisturbed) emergence date, we 
assigned a serious injury Level A harassment take for each cub. In the 
absence of information about cub age and intended emergence date (which 
was known only for simulated dens), den emergences that occurred 
between (and including) February 14 and March 14 were considered to be 
early emergences and resulted in a serious injury Level A harassment 
take of each cub. If a den emergence occurred after March 14 but was 
clearly linked to an exposure (e.g., bear observed emerging from the 
den when activity initiated near the den), we considered the emergence 
to be early and resulted in a serious injury Level A harassment take of 
each cub.
     For dens where emergence was not classified as early, if 
an exposure occurred during the post-emergence period and bears 
departed the den site prior to their intended (i.e., undisturbed) 
departure date, we assigned a non-serious injury Level A harassment 
take for each cub. In the absence of information about the intended 
departure date (which was known only for simulated dens), den site 
departures that occurred less than 8 days after the emergence date were 
considered to be early departures and resulted in a non-serious injury 
Level A harassment take of each cub.
Den Simulation
    We simulated dens across the entire north slope of Alaska, ranging 
from the areas identified as denning habitat (Blank 2013, Durner et al. 
2006, 2013) contained within the National Petroleum Reserve--Alaska 
(NPRA) in the west to the Canadian border in the east. While AOGA's 
Request does not include activity inside ANWR, we still simulated dens 
in that area to ensure that any activities directly adjacent to the 
refuge that might impact denning bears inside the refuge would be 
captured. 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 NPRA, the area between the 
Colville and Canning Rivers (CC), and ANWR. The mean estimated number 
of dens in each region during a given winter were as follows: 12 dens 
(95% CI: 3-26) in the NPRA, 26 dens (95% CI: 11-48) in the CC region, 
and 14 dens (95% CI: 5-30) in ANWR (Atwood et al. 2020). For each 
iteration of the model (described below), we drew a random sample from 
a gamma distribution for each of the regions based on the above 
parameter estimates, which allowed uncertainty in the number of dens in 
each area to be propagated through the modeling process. Specifically, 
we used the method of moments (Hobbs and Hooten 2015) to develop the 
shape and rate parameters for the gamma distributions as follows: NPRA 
(12\2\/5.8\2\,12/5.8\2\), CC (26\2\/9.5\2\,26/9.5\2\), and ANWR (14\2\/
6.3\2\,14/6.3\2\).
    Because not all areas in northern Alaska are equally used for 
denning and some areas do not contain the requisite topographic 
attributes required for sufficient snow accumulation for den 
excavation, we did not randomly place dens on the landscape. Instead, 
we followed a similar approach to that used by Wilson and Durner (2020) 
with some additional modifications to account for differences in 
denning ecology in the CC region related to a preference to den on 
barrier islands and a general (but not complete) avoidance of actively 
used industrial infrastructure. Using the USGS polar bear den catalogue 
(Durner et al. 2020), we identified polar bear dens that occurred on 
land in the CC region and that were identified either by GPS-collared 
bears or through systematic surveys for denning bears (Durner et al. 
2020). This resulted in a sample of 37 dens of which 22 (i.e., 60 
percent) occurred on barrier islands. For each iteration of the model, 
we then determined how many of the estimated dens in the CC region 
occurred on barrier islands versus the mainland.
    To accomplish this, we first took a random sample from a binomial 
distribution to determine the expected number of dens from the den 
catalog (Durner et al. 2020) that should occur on barrier islands in 
the CC region during that given model iteration; nbarrier = 
Binomial(37,22/37), where 37 represents the total number of dens in the 
den catalogue (Durner et al. 2020) in the CC region suitable for use 
(as described above) and 22/37 represents the observed proportion of 
dens in the CC region that occurred on barrier islands. We then divided 
nbarrier by the total number of dens in the CC region suitable for use 
(i.e., 37) to determine the proportion of dens in the CC region that 
should occur on barrier islands (i.e., pbarrier). We then multiplied 
pbarrier with the simulated number of dens in the CC region (rounded to 
the nearest whole number) to determine how many dens were simulated to 
occur on barriers islands in the region.
    In the NPRA, the den catalogue (Durner et al. 2020) data indicated 
that two dens occurred outside of defined denning habitat (Durner et 
al. 2013), so we took a similar approach as with the barrier islands to 
estimate how many dens occur in areas of the NPRA with the den habitat 
layer during each iteration of the model; nhabitat ~ Binomial(15, 13/
15), where 15 represents the total number of dens in NPRA from the den 
catalogue (Durner et al. 2020) suitable for use (as described above), 
and 13/15 represents the observed proportion of dens in NPRA that 
occurred in the region with den habitat coverage (Durner et al. 2013). 
We then divided nhabitat by the total number of dens in NPRA from the 
den catalogue (i.e., 15) to determine proportion of dens in the NPRA 
region that occurred in the region of the den habitat layer (phabitat). 
We then multiplied phabitat with the simulated number of dens in NPRA 
(rounded to the nearest whole number) to determine the number of dens 
in NPRA that occurred in the region with the den habitat layer. Because 
no infrastructure exists and no activities are proposed to occur in the 
area of NPRA without the den habitat layer, we only considered the 
potential impacts of activity to those dens simulated to occur

[[Page 43027]]

in the region with denning habitat identified (Durner et al. 2013).
    To account for the potential influence of industrial activities and 
infrastructure on the distribution of polar bear selection of den 
sites, we again relied on the subset of dens from the den catalogue 
(Durner et al. 2020) discussed above. We further restricted the dens to 
only those occurring on the mainland because no permanent 
infrastructure occurred on barrier islands with identified denning 
habitat (Durner et al. 2006). We then determined the minimum distance 
to permanent infrastructure that was present when the den was 
identified. This led to an estimate of a mean minimum distance of dens 
to infrastructure being 21.59 km (SD = 16.82). From these values, we 
then parameterized a gamma distribution: Gamma(21.59\2\/16.82\2\, 
21.59/16.82\2\). We then obtained 100,000 samples from this 
distribution and created a discretized distribution of distances 
between dens and infrastructure. We created 2.5-km intervals between 0 
and 45 km, and one bin for areas >45 km from infrastructure and 
determined the number of samples that occurred within each distance 
bin. We then divided the number of samples in each bin by the total 
number of samples to determine the probability of a simulated den 
occurring in a given distance bin. The choice of 2.5 km for distance 
bins was based on a need to ensure that kernel density grid cells 
occurred in each distance bin.
    To inform where dens are most likely to occur on the landscape, we 
developed a kernel density map by using known den locations in northern 
Alaska identified either by GPS-collared bears or through systematic 
surveys for denning bears (Durner et al. 2020). To approximate the 
distribution of dens, we used an adaptive kernel density estimator 
(Terrell and Scott 1992) applied to n observed den location, which took 
the form
[GRAPHIC] [TIFF OMITTED] TR05AU21.019

where the adaptive bandwidth h(s) = ([beta]0 + 
[beta]1I(si [isin] M)I(s [isin] M))[beta]2 for 
the location of the ith den and each location s in the study area. The 
indicator functions allowed the bandwidth to vary abruptly between the 
mainland M and barrier islands. The kernel k was the Gaussian kernel, 
and the parameters [theta], [beta]0, [beta]1, 
[beta]2 were chosen based on visual assessment so that the 
density estimate approximated the observed density of dens and our 
understanding of likely den locations in areas with low sampling 
effort.
    The kernel density map we used for this analysis differs slightly 
from the version used in previous analyses, specifically our 
differentiation of barrier islands from mainland habitat. We used this 
modified version because previous analyses did not require us to 
consider denning habitat in the CC region, which has a significant 
amount of denning that occurs on barrier islands compared to the other 
two regions. If barrier islands were not differentiated for the kernel 
density estimate, density from the barrier island dens would spill over 
onto the mainland, which was deemed to be biologically unrealistic 
given the clear differences in den density between the barrier islands 
and the mainland in the region. For each grid cell in the kernel 
density map within the CC region, we then determined the minimum 
distance to roads and pads that had occupancy >=0.50 identified by AOGA 
during October through December (i.e., the core period when bears were 
establishing their dens). We restricted the distance to infrastructure 
component to only the CC region because it is the region that contains 
the vast majority of oil and gas infrastructure and has had some form 
of permanent industrial infrastructure present for more than 50 years. 
Thus, denning polar bears have had a substantial amount of time to 
modify their selection of where to den related to the presence of human 
activity.
    To simulate dens on the landscape, we first sampled in which kernel 
grid cell a den would occur based on the underlying relative 
probability (Figure 6) within a given region using a multinomial 
distribution. Once a cell was selected, the simulated den was randomly 
placed on the denning habitat (Blank 2013, Durner et al. 2006, 2013) 
located within that grid cell. For dens being simulated on mainland in 
the CC region, an additional step was required. We first assigned a 
simulated den a distance bin using a multinomial distribution of 
probabilities of being located in a given distance bin based on the 
discretized distribution of distances described above. Based on the 
distance to infrastructure bin assigned to a simulated den, we subset 
the kernel density grid cells that occurred in the same distance bin 
and then selected a grid cell from that subset based on their 
underlying probabilities using a multinomial distribution. Then, 
similar to other locations, a den was randomly placed on denning 
habitat within that grid cell.

[[Page 43028]]

[GRAPHIC] [TIFF OMITTED] TR05AU21.015

    For each simulated den, we assigned dates of key denning events; 
den entrance, birth of cubs, when cubs reached 60 days of age, den 
emergence, and departure from the den site after emergence. These 
represent the chronology of each den under undisturbed conditions. We 
selected the entrance date for each den from a normal distribution 
parameterized by entrance dates of radio-collared bears in the Southern 
Beaufort subpopulation that denned on land included in Rode et al. 
(2018) and published in USGS (2018; n = 52, mean = 11 November, SD = 18 
days). These data were restricted to those dens with both an entrance 
and emergence data identified and where a bear was in the den for 
greater than or equal to 60 days to reduce the chances of including 
non-maternal bears using shelter dens. Sixty days represents the 
minimum age of cubs before they have a chance of survival outside of 
the den. Thus, periods less than 60 days in the den have a higher 
chance of being shelter dens.
    We truncated this distribution to ensure that all simulated dates 
occurred within the range of observed values (i.e., 12 September to 22 
December) identified in USGS (2018) to ensure that entrance dates were 
not simulated during biologically unreasonable periods given that the 
normal distribution allows some probability (albeit small) of dates 
being substantially outside a biologically reasonable range. We 
selected a date of birth for each litter from a normal distribution 
with the mean set to ordinal date 348 (i.e., 15 December) and standard 
deviation of 10, which allowed the 95 percent CI to approximate the 
range of birth dates (i.e., December 1 to January 15) identified in the 
peer-reviewed literature (Messier et al. 1994, Van de Velde et al. 
2003). We ensured that simulated birth dates occurred after simulated 
den entrance dates. We selected the emergence date as a random draw 
from an asymmetric Laplace distribution with parameters [mu] = 81.0, 
[sigma] = 4.79, and p = 0.79 estimated from the empirical emergence 
dates in Rode et al. (2018) and published in USGS (2018, n = 52) of 
radio-collared bears in the Southern Beaufort Sea stock that denned on 
land using the mleALD function from package `ald' (Galarzar and Lachos 
2018) in program R (R Core Development Team 2021). We constrained 
simulated emergence dates to occur within the range of observed 
emergence dates (January 9 to April 9, again to constrain dates to be 
biologically realistic) and to not occur until after cubs were 60 days 
old. Finally, we assigned the number of days each family group spent at 
the den site post-emergence based on values reported in four behavioral 
studies, Smith et al. (2007, 2010, 2013) and Robinson (2014), which 
monitored dens near immediately after emergence (n = 25 dens). 
Specifically, we used the mean (8.0) and SD (5.5) of the dens monitored 
in these studies to parameterize a gamma distribution using the method 
of moments (Hobbs and Hooten 2015) with a shape parameter equal to 
8.0\2\/5.5\2\ and a rate parameter equal to 8.0/5.5\2\; we selected a 
post-emergence, pre-departure time for each den from this distribution. 
We restricted time at the den post emergence to occur within the range 
of times observed in Smith et al. (2007, 2010, 2013) and Robinson 
(2014) (i.e., 2-23 days, again to ensure biologically realistic times 
spent at the den site were simulated). Additionally, we assigned each 
den a litter size by drawing the number of cubs from a multinomial 
distribution with probabilities derived from litter sizes (n = 25 
litters) reported in Smith et al. (2007, 2010, 2013) and Robinson 
(2014).
    Because there is some probability that a female naturally emerges 
with 0 cubs, we also wanted to ensure this scenario was captured. It is 
difficult to parameterize the probability of litter size equal to 0 
because it is rarely observed. We, therefore, assumed that dens in the 
USGS (2018) dataset that had denning durations less than the shortest 
den duration where a female

[[Page 43029]]

was later observed with cubs (i.e., 79 days) had a litter size of 0. 
There were only 3 bears in the USGS (2018) data that met this criteria, 
leading to an assumed probability of a litter size of 0 at emergence 
being 0.07. We, therefore, assigned the probability of 0, 1, 2, or 3 
cubs as 0.07, 0.15, 0.71, and 0.07, respectively.
Infrastructure and Human Activities
    The model developed by Wilson and Durner (2020) provides a template 
for estimating the level of potential impact to denning polar bears of 
proposed activities while also considering the natural denning ecology 
of polar bears in the region. The approach developed by Wilson and 
Durner (2020) also allows for the incorporation of uncertainty in both 
the metric associated with denning bears and in the timing and spatial 
patterns of proposed activities when precise information on those 
activities is unavailable. Below we describe the different sources of 
potential disturbance we considered within the model. We considered 
infrastructure and human activities only within the area of proposed 
activity in the ITR Request. However, given that activity on the border 
of this region could still affect dens falling outside of the area 
defined in the ITR Request, we also considered the impacts to denning 
bears within a 1-mile buffer outside of the proposed activity area.
Roads and Pads
    We obtained shapefiles of existing and proposed road and pad 
infrastructure associated with industrial activities from AOGA. Each 
attribute in the shapefiles included a monthly occupancy rate that 
ranged from 0 to 1. For this analysis, we assumed that any road or pad 
with occupancy greater than 0 for a given month had the potential for 
human activity during the entire month unless otherwise noted.
Ice Roads and Tundra Travel
    We obtained shapefiles of proposed ice road and tundra travel 
routes from AOGA. We also received information on the proposed start 
and end dates for ice roads and tundra routes each winter from AOGA 
with activity anticipated to occur at least daily along each.
Seismic Surveys
    Seismic surveys are planned to occur in the central region of the 
project area proposed by AOGA (Figure 7). The region where seismic 
surveys would occur were split into two different portions representing 
relatively high and relatively low probabilities of polar bear dens 
being present (Figure 7). During any given winter, no more than 766 
km\2\ and 1183 km\2\ will be surveyed in the high- and low-density 
areas, respectively. Therefore, for this analysis, we estimated take 
rates by assuming that seismic surveys would occur in the portions of 
those areas with the highest underlying probabilities of denning 
occurring and covering the largest area proposed in each (i.e., 766 
km\2\ and 1183 km\2\). All seismic surveys could start as early as 
January 1 and operate until April 15.
[GRAPHIC] [TIFF OMITTED] TR05AU21.016


[[Page 43030]]


Pipelines
    We obtained shapefiles of existing and proposed pipelines, as well 
as which months and years each pipeline would be operational, from 
AOGA. Based on the description in the Request, we assumed that all 
pipelines would have aerial surveys conducted weekly with aircraft 
flying at altitudes <457.2 m (<1,500 ft) and potentially exposing polar 
bears to disturbance.
Other Aircraft Activities
    Aside from flights to survey pipelines, the majority of aircraft 
flights are expected to occur at altitudes >457.2 m (>1,500 ft). After 
reviewing current and proposed flight patterns for flights likely to 
occur at altitudes <457.2 m (<1,500 ft), we found one flight path that 
we included in the model. The flight path is between the Oooguruk drill 
site and the onshore tie-in pad with at least daily flights between 
September 1 and January 31. We, therefore, also considered these 
flights as a continuous source of potential exposure to denning bears.
Aerial Infrared Surveys
    Based on AOGA's Request, we assumed that all permanent 
infrastructure (i.e., roads, pipelines, and pads), tundra travel 
routes, and ice roads would receive two aerial infrared (AIR) surveys 
of polar bear den habitat within 1 mile of those features each winter. 
The first survey could occur between December 1 and 25 and the second 
between December 15 through January 10 with at least 24 hours between 
the completion of the first survey and the beginning of the second. 
During winters when seismic surveys occur, additional AIR surveys would 
be required. A total of three AIR surveys of any den habitat within 1 
mile of the seismic survey area would be required prior to any seismic-
related activities occurring (e.g., advance crews checking ice 
conditions). The first AIR survey would need to occur between November 
25 and December 15, the second between December 5 and 31, and the third 
between December 15 and January 15 with the same minimum of 24 hours 
between subsequent surveys. Similarly, during winters when seismic 
surveys occur, an additional AIR survey would be required of denning 
habitat within 1 mile of the pipeline between Badami and the road to 
Endicott Island. The additional survey of the pipeline (to create a 
total of three) would need to occur between December 5 and January 10.
    During each iteration of the model, each AIR survey was randomly 
assigned a probability of detecting dens. Whereas previous analyses 
have used the results of Wilson and Durner (2020) to inform this 
detection probability, two additional studies (Smith et al. 2020, 
Woodruff et al. in prep.) have been conducted since Wilson and Durner 
(2020) was published that require an updated approach. The study by 
Woodruff et al. (in prep.) considered the probability of detecting heat 
signatures from artificial polar bear dens. They did not find a 
relationship between den snow depth and detection and estimated a mean 
detection rate of 0.24. A recent study by Smith et al. (2020) estimated 
that the detection rate for actual polar bear dens in northern Alaska 
was 0.45 and also did not report any relationship between detection and 
den snow depth. Because the study by Wilson and Durner (2020) reported 
detection probability only for dens with less than 100 cm snow depth, 
we needed to correct it to also include those dens with greater than 
100 cm snow depth. Based on the distribution of snow depths used by 
Wilson and Durner (2020) derived from data in Durner et al. (2003), we 
determined that 24 percent of dens have snow depths greater than 100 
cm. After taking these into account, the overall detection probability 
from Wilson and Durner (2020) including dens with snow depths greater 
than 100 cm was estimated to be 0.54. This led to a mean detection of 
0.41 and standard deviation of 0.15 across the three studies. We used 
these values, and the method of moments (Hobbs and Hooten 2015), to 
inform a Beta distribution (i.e.,
[GRAPHIC] [TIFF OMITTED] TR05AU21.017

from which we drew a detection probability for each of the simulated 
AIR surveys during each iteration of the model.
Model Implementation
    For each iteration of the model, we first determined which dens 
were exposed to each of the simulated activities and infrastructure. We 
assumed that any den within 1.6 km (1 mi) of infrastructure or human 
activities was exposed and had the potential to be disturbed as 
numerous studies have suggested a 1.6-km buffer is sufficient to reduce 
disturbance to denning polar bears (MacGillivray et al. 2003, Larson et 
al. 2020, Owen et al. 2021). If, however, a den was detected by an AIR 
survey prior to activity occurring within 1.6 km of it, we assumed a 
1.6-km buffer would be established to restrict activity adjacent to the 
den and there would be no potential for future disturbance. If a den 
was detected by an AIR survey after activity occurred within 1.6 km of 
it, as long as the activity did not result in a Level A harassment or 
lethal take, we assumed a 1.6-km buffer would be applied to prevent 
disturbance during future denning periods. For dens exposed to human 
activity (i.e., not detected by an AIR survey), we then identified the 
stage in the denning cycle when the exposure occurred based on the date 
range of the activities the den was exposed to. We then determined 
whether the exposure elicited a response by the denning bear based on 
probabilities derived from the reviewed case studies (Table 7). Level B 
harassment was applicable to both adults and cubs, if present, whereas 
Level A harassment (i.e., serious injury and non-serious injury) and 
lethal take were applicable only to cubs because the proposed 
activities had a discountable risk of running over dens and thus 
killing a female or impacting her future reproductive potential. The 
majority of proposed activities occur on established, permanent 
infrastructure that would not be suitable for denning and therefore, 
pose no risk of being run over (i.e., an existing road). For those 
activities off permanent infrastructure (i.e., ice roads and tundra 
travel routes), crews will constantly be on the lookout for signs of 
denning, use vehicle-based forward looking infrared cameras to scan for 
dens, and will largely avoid crossing topographic features suitable for 
denning given operational constraints. Thus, the risk of running over a 
den was deemed to have a probability so low that it was discountable.
    Based on AOGA's description of their proposed activities, we only 
considered AIR surveys and pipeline inspection surveys as discrete 
exposures given that surveys occur quickly (i.e., the time for an 
airplane to fly over) and infrequently. For all other activities, we 
applied probabilities associated with repeated exposure (Table 7). For 
the pipeline surveys, we made one modification to the probabilities 
applied compared to

[[Page 43031]]

those listed in Table 7. The case studies used to inform the post-
emergence period include one where an individual fell into a den and 
caused the female to abandon her cubs. Given that pipeline surveys 
would either occur with a plane or a vehicle driving along an 
established path adjacent to a pipeline, there would be no chance of 
falling into a den. Therefore, we excluded this case study from the 
calculation of disturbance probabilities applied to our analysis, which 
led to a 0 percent probability of lethal take and a 100 percent 
probability of non-serious injury Level A harassment.
    For dens exposed to human activity, we used a multinomial 
distribution with the probabilities of different levels of take for 
that period (Table 7). If a Level A harassment or 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. As noted above, Level A harassments and 
lethal takes only applied to cubs because proposed activities would not 
result in those levels of take for adult females. Adult females, 
however, could still receive Level B harassment during the den 
establishment period or any time cubs received Level B harassment, 
Level A harassment (i.e., serious injury and non-serious injury), or 
lethal take.
    We developed the code to run this model in program R (R Core 
Development Team 2021) and ran 10,000 iterations of the model (i.e., 
Monte Carlo simulation) to derive the estimated number of animals 
disturbed and associated levels of take. We ran the model for each of 
the five winters covered by the ITR (i.e., 2021/2022, 2022/2023, 2023/
2024, 2024/2025, 2025/2026). For each winter's analysis, we analyzed 
the most impactful scenario that was possible. For example, seismic 
surveys may not occur every winter, but it is unclear which winters 
would have seismic surveys and which would not. Therefore, each of the 
scenarios were run with the inclusion of seismic surveys (and their 
additional AIR surveys) knowing that take rates will be less for a 
given winter if seismic surveys did not occur. Similarly, in some 
winters, winter travel between Deadhorse and Point Thomson will occur 
along an ice road running roughly parallel to the pipeline connecting 
the two locations. However, in other winters, the two locations will be 
connected via a tundra travel route farther south. Through preliminary 
analyses, we found that the tundra travel route led to higher annual 
take estimates. Therefore, for each of the scenarios, we only 
considered the tundra travel route knowing that take rates will be less 
when the more northern ice road is used.
Model Results
    On average, we estimated 52 (median = 51; 95% CI: 30-80) land-based 
dens in the area of proposed activity in AOGA's Request within a 1.6-km 
(1-mi) buffer. Annual estimates for different levels of take are 
presented in Table 8. We also estimated that Level B harassment take 
from AIR surveys was never greater than a mean of 1.53 (median = 1; 95% 
CI: 0-5) during any winter. The distributions of both non-serious Level 
A and serious Level A/Lethal possible takes were non-normal and heavily 
skewed, as indicated by markedly different mean and median values. The 
heavily skewed nature of these distributions has led to a mean value 
that is not representative of the most common model result (i.e., the 
median value), which for both non-serious Level A and serious Level A/
Lethal takes is 0.0 takes. Due to the low (<0.29 for non-serious Level 
A and <=0.462 for serious Level A/Lethal takes) probability of greater 
than or equal to 1 non-serious or serious injury Level A harassment/
Lethal take each year of the proposed ITR period, combined with the 
median of 0.0 for each, we do not estimate the proposed activities will 
result in non-serious or serious injury Level A harassment or lethal 
take of polar bears.

                                                       Table 8--Results of the Den Disturbance Model for Each Winter of Proposed Activity
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                          Level B harassment                          Non-serious Level A                       Serious Level A/lethal
                        Winter (20XX)                        -----------------------------------------------------------------------------------------------------------------------------------
                                                                 Prob       Mean       Med       95% CI      Prob       Mean       Med       95% CI      Prob       Mean       Med       95% CI
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
21-22.......................................................       0.89        3.1        3.0        0-9       0.28        0.7        0.0        0-4       0.45        1.2        0.0        0-5
22-23.......................................................       0.90        3.2        3.0        0-9       0.29        0.7        0.0        0-4       0.46        1.2        0.0        0-6
23-24.......................................................       0.90        3.1        3.0        0-9       0.28        0.6        0.0        0-4       0.46        1.2        0.0        0-5
24-25.......................................................       0.90        3.1        3.0        0-9       0.28        0.6        0.0        0-4       0.46        1.2        0.0        0-6
25-26.......................................................       0.90        3.2        3.0        0-9       0.28        0.7        0.0        0-4       0.46        1.2        0.0        0-5
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Estimates are provided for the probability (Prob), mean, median (Med), and 95% Confidence Intervals (CI) for Level B, Non-Serious Level A, and Serious Level A/Lethal take. The probabilities
  represent the probability of >=1 take of a bear occurring during a given winter.

Maritime Activities

Vessel Traffic
    Maritime activities were divided into two categories of potential 
impact: vessel traffic and in-water construction. Vessel traffic was 
further divided into two categories: Repeated, frequent trips by small 
boats and hovercraft for crew movement and less frequent trips to move 
fuel and equipment by tugs and barges. We estimated the potential Level 
B harassment take from the repeated, frequent trips by crew boats and 
hovercraft in Polar Bear: Surface Interactions as marine roads using an 
occupancy rate of 0.2. This occupancy rate accounts for 20 percent of 
the impact area (i.e., the length of the route buffered by 1.6 km (1 
mi)) being impacted at any given point throughout the year, which is 
consistent with the daily trips described by AOGA.
    For less frequent trips for fuel and equipment resupply by tugs and 
barges, AOGA has supplied the highest expected number of trips that may 
be taken each year. Because we have been supplied with a finite number 
of potential trips, we used the impact area of the barge/tug 
combination as it moves in its route from one location to the next. We 
estimated a 16.5-km\2\ (6.37-mi\2\) take area for the barge, tug, and 
associated tow line, which accounts for a barge, tow, and tug length of 
200 m (656 ft), width of 100 m (328 ft), and a 1.6-km (1-mi) buffer 
surrounding the vessels. We calculated the total hours of impact using 
an average vessel speed of two knots (3.7 km/hr), and then calculated 
the proportion of the open-water season that would be impacted (Table 
9).

[[Page 43032]]



  Table 9--Calculation of the Total Number of Barge and Tug Vessel Trip Hours and the Proportion of the Season
                  Polar Bears May be Impacted in a 16.5-km\2\ Impact Area by Barge/Tug Presence
----------------------------------------------------------------------------------------------------------------
                                                                    Est. length                     Total time
            Origin                 Destination       Frequency         (km)       Time/trip (hr)       (hr)
----------------------------------------------------------------------------------------------------------------
West Dock.....................  Milne Point.....               1              38              10              10
Milne Point...................  West Dock.......               1              38              10              10
West Dock.....................  Endicott........              30              22               6             178
Endicott......................  Badami..........              10              42              11             114
Badami........................  Pt. Thomson.....              10              32               9              86
Pt. Thomson...................  West Dock.......              10              96              26             259
                                                 ---------------------------------------------------------------
    Total Hours...............  ................  ..............  ..............  ..............             658
----------------------------------------------------------------------------------------------------------------
Proportion of Season Impacted by Barge/Tug Use                                                              0.24
----------------------------------------------------------------------------------------------------------------

    The number of estimated takes was then calculated using Equation 4, 
in which the impact area is multiplied by encounter rate, proportion of 
season, and harassment rate for the open-water season. The final number 
of estimated Level B harassment events from barge/tug trips was 1.12 
bears per year.
In-Water Construction
    Polar bears are neither known to vocalize underwater nor to rely 
substantially upon underwater sounds to locate prey. However, for any 
predator, loss of hearing is likely to be an impediment to successful 
foraging. The Service has applied a 190 dB re 1 [micro]Pa threshold for 
TTS and a 180 dB re1[micro]Pa threshold for Level B harassment arising 
from exposure of polar bears to underwater sounds for previous 
authorizations in the Beaufort and Chukchi Seas; seas. However, given 
the projection of polar bear TTS at 188 dB by Southall et al. (2019) 
referenced in Figure 1, we used a threshold of Level B harassment at 
180 dB re 1 [micro]Pa in our analysis for these regulations.
    The proposal for the 2021-2026 ITR period includes several 
activities that will create underwater sound, including dredging, 
screeding, pile driving, gravel placement, and geohazard surveys. 
Underwater sounds and the spatial extent to which they propagate are 
variable and dependent upon the sound source (e.g., size and 
composition of a pile for pile driving, equipment type for geophysical 
surveys, etc.), the installation method, substrate type, presence of 
sea ice, and water depth. Source levels range from less than 160 dB re 
1 [micro]Pa to greater than 200 dB re 1 [micro]Pa (Rodkin and 
Pommerenck, 2014), meaning some sounds reach the level of TTS, however 
they do not reach the level of PTS (Table 1). Although these activities 
result in underwater areas that are above the 180 dB Level B harassment 
threshold for polar bears, the areas above the threshold will be small 
and fall within the current impact area (1.6 km) used to estimate polar 
bear harassment due to surface interactions. Thus, additional 
harassment calculations based on in-water noise are not necessary. 
Similarly, any in-air sounds generated by underwater sources are not 
expected to propagate above the Level B harassment thresholds listed in 
Table 1 beyond the 1.6-km (1.0-mi) impact area established in Polar 
Bear: Surface Interactions.

Sum of Harassment From All Sources

    A summary of total numbers of estimated take by Level B harassments 
during the duration of the project by season and take category is 
provided in Table 10. The potential for lethal or Level A harassment 
was explored. The highest probability of greater than or equal to 1 
lethal or serious Level A harassment take of polar bears over the 5-
year ITR period was 0.462.

                                 Table 10--Total Estimated Level B Harassment Events of Polar Bears per Year and Source
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Level B harassment of polar bears on the surface or in water
                                                         --------------------------------------------------------------------------------
                          Year                                Surface         Seismic         Vessel         Aircraft                          Total
                                                             activity       exploration      activity       overflights    Denning bears
--------------------------------------------------------------------------------------------------------------------------------------------------------
Open water 2021-Ice 2021/2022...........................           56.54            1.94            1.12            0.82             3.1              65
Open water 2022-Ice 2022/2023...........................           83.77            1.94            1.12            0.95             3.2              91
Open water 2023-Ice 2023/2024...........................           84.28            1.94            1.12            0.95             3.1              92
Open water 2024-Ice 2024/2025...........................           84.23            1.94            1.12            1.09             3.1              92
Open water 2025-Ice 2025/2026...........................           84.48            1.94            1.12            1.09             3.2              92
Open water 2026.........................................              12            0.00            1.12            0.15               0              14
--------------------------------------------------------------------------------------------------------------------------------------------------------

Critical Assumptions

    To conduct this analysis and estimate the potential amount of Level 
B harassment, several critical assumptions were made.
    Level B harassment is equated herein with behavioral responses that 
indicate harassment or disturbance. There is likely a portion of 
animals that respond in ways that indicate some level of disturbance 
but do not experience significant biological consequences. Our 
estimates do not account for variable responses by polar bear age and 
sex; however, sensitivity of denning bears was incorporated into the 
analysis. The available information suggests that polar bears are 
generally resilient to low levels of disturbance. Females with 
dependent young and juvenile polar bears are physiologically the most 
sensitive (Andersen and Aars 2008) and most likely to experience 
harassment from disturbance. There is not enough information on 
composition of the SBS polar bear stock in the ITR area to incorporate 
individual variability based on age and sex or to predict its influence 
on harassment estimates. Our estimates are derived from a variety of 
sample populations with various age and sex structures, and we assume 
the exposed population will have a similar

[[Page 43033]]

composition and therefore, the response rates are applicable.
    The estimates of behavioral response presented here do not account 
for the individual movements of animals away from the ITR area or 
habituation of animals to noise or human presence. Our assessment 
assumes animals remain stationary, (i.e., density does not change). 
There is not enough information about the movement of polar bears in 
response to specific disturbances to refine this assumption. This 
situation could result in overestimation of harassment; however, we 
cannot account for harassment resulting from a polar bear moving into 
less preferred habitat due to disturbance.

Potential Effects of Oil Spills on Pacific Walruses and Polar Bears

    Walrus and polar bear ranges overlap with many active and planned 
Industry activities--resulting in associated risks of oil spills from 
facilities, ships, and pipelines in both offshore and onshore habitat. 
To date, no major offshore oil spills have occurred in the Alaska 
Beaufort Sea. Although numerous small onshore spills have occurred on 
the North Slope. To date, there have been no documented effects to 
polar bears.
    Oil spills are unintentional releases of oil or petroleum products. 
In accordance with the National Pollutant Discharge Elimination System 
Permit Program, all North Slope oil companies must submit an oil spill 
contingency plan. It is illegal to discharge oil into the environment, 
and a reporting system requires operators to report spills. Between 
1977 and 1999, an average of 70 oil and 234 waste product spills 
occurred annually on the North Slope oilfields. Although most spills 
have been small by Industry standards (less than 50 bbl), larger spills 
(more than 500 bbl) accounted for much of the annual volume. In the 
North Slope, a total of seven large spills occurred between 1985 and 
2009. The largest of these spills occurred in the spring of 2006 when 
approximately 6,190 bbl leaked from flow lines near an oil gathering 
center. More recently, several large spills have occurred. In 2012, 
1,000 bbl of drilling mud and 100 bbl of crude were spilled in separate 
incidents; in 2013, approximately 166 bbl of crude oil was spilled; and 
in 2014, 177 bbl of drilling mud was spilled. In 2016, 160 bbl of mixed 
crude oil and produced water was spilled. These spills occurred 
primarily in the terrestrial environment in heavily industrialized 
areas not utilized by walruses or polar bears and therefore, posed 
little risk to the animals.
    The two largest onshore oil spills were in the terrestrial 
environment and occurred because of pipeline failures. In the spring of 
2006, approximately 6,190 bbl of crude oil spilled from a corroded 
pipeline operated by BP Exploration (Alaska). The spill impacted 
approximately 0.8 ha (~2 ac). In November 2009, a spill of 
approximately 1,150 bbl from a ``common line'' carrying oil, water, and 
natural gas operated by BP occurred as well, impacting approximately 
780 m\2\ (~8,400 ft\2\). None of these spills were known to impact 
polar bears, in part due to the locations and timing. Both sites were 
within or near Industry facilities not frequented by polar bears, and 
polar bears are not typically observed in the affected areas during the 
time of the spills and subsequent cleanup.
    Nonetheless, walruses and polar bears could encounter spilled oil 
from exploratory operations, existing offshore facilities, pipelines, 
or from marine vessels. The shipping of crude oil, oil products, or 
other toxic substances, as well as the fuel for the shipping vessels, 
increases the risk of a spill.
    As additional offshore Industry projects are planned, the potential 
for large spills in the marine environment increases. Oil spills in the 
sea-ice environment, at the ice edge, in leads, polynyas, and similar 
areas of importance to walruses and polar bears present an even greater 
challenge because of both the difficulties associated with cleaning oil 
in sea-ice along with the presence of wildlife in those areas.
    Oiling of food sources, such as ringed seals, may result in 
indirect effects on polar bears, such as a local reduction in ringed 
seal numbers, or a change to the local distribution of seals and bears. 
More direct effects on polar bears could occur from: (1) Ingestion of 
oiled prey, potentially resulting in reduced survival of individual 
bears; (2) oiling of fur and subsequent ingestion of oil from grooming; 
(3) oiling and fouling of fur with subsequent loss of insulation, 
leading to hypothermia; and (4) disturbance, injury, or death from 
interactions with humans during oil spill response activities. Polar 
bears may be particularly vulnerable to disturbance when nutritionally 
stressed and during denning. Cleanup operations that disturb a den 
could result in death of cubs through abandonment, and perhaps, death 
of the female as well. In spring, females with cubs of the year that 
denned near or on land and migrate to contaminated offshore areas may 
encounter oil following a spill (Stirling in Geraci and St. Aubin 
1990).
    In the event of an oil spill, the Service follows oil spill 
response plans, coordinates with partners, and reduces the impact of a 
spill on wildlife. Several factors will be considered when responding 
to an oil spill--including spill location, magnitude, oil viscosity and 
thickness, accessibility to spill site, spill trajectory, time of year, 
weather conditions (i.e., wind, temperature, precipitation), 
environmental conditions (i.e., presence and thickness of ice), number, 
age, and sex of walruses and polar bears that are (or are likely to be) 
affected, degree of contact, importance of affected habitat, cleanup 
proposal, and likelihood of human-bear interactions. Response efforts 
will be conducted under a three-tier approach characterized as: (1) 
Primary response, involving containment, dispersion, burning, or 
cleanup of oil; (2) secondary response, involving hazing, herding, 
preventative capture/relocation, or additional methods to remove or 
deter wildlife from affected or potentially affected areas; and (3) 
tertiary response, involving capture, cleaning, treatment, and release 
of wildlife. If the decision is made to conduct response activities, 
primary and secondary response options will be vigorously applied. 
Tertiary response capability has been developed by the Service and 
partners, though such response efforts would most likely be able to 
handle only a few animals at a time. More information is available in 
the Service's oil spill response plans for walruses and polar bears in 
Alaska, which is located at: https://www.fws.gov/r7/fisheries/contaminants/pdf/Polar%20Bear%20WRP%20final%20v8_Public%20website.pdf.
    BOEM has acknowledged that there are difficulties in effective oil-
spill response in broken-ice conditions, and the National Academy of 
Sciences has determined that ``no current cleanup methods remove more 
than a small fraction of oil spilled in marine waters, especially in 
the presence of broken ice.'' BOEM advocates the use of non-mechanical 
methods of spill response, such as in-situ burning during periods when 
broken ice would hamper an effective mechanical response (MMS 2008). An 
in-situ burn has the potential to rapidly remove large quantities of 
oil and can be employed when broken-ice conditions may preclude 
mechanical response. However, the resulting smoke plume may contain 
toxic chemicals and high levels of particulates that can pose health 
risks to marine mammals, birds, and other wildlife as well as to 
humans. As a result, smoke trajectories must be considered before 
making the decision to burn spilled oil. Another potential

[[Page 43034]]

non-mechanical response strategy is the use of chemical dispersants to 
speed dissipation of oil from the water surface and disperse it within 
the water column in small droplets. However, dispersant use presents 
environmental trade-offs. While walruses and polar bears would likely 
benefit from reduced surface or shoreline oiling, dispersant use could 
have negative impacts on the aquatic food chain. Oil spill cleanup in 
the broken-ice and open-water conditions that characterize Arctic 
waters is problematic.

Evaluation of Effects of Oil Spills on Pacific Walruses and Polar Bears

    The MMPA does not authorize the incidental take of marine mammals 
as the result of illegal actions, such as oil spills. Nor do the 
specified activities in AOGA's request include oil spills. Any event 
that results in an injurious or lethal outcome to a marine mammal is 
not authorized under this ITR. However, for the purpose of developing a 
more complete context for evaluating potential effects on walruses and 
polar bears, the Service evaluated the potential impacts of oil spills 
within the Beaufort Sea ITR region.

Pacific Walrus

    As stated earlier, the Beaufort Sea is not within the primary range 
for walruses. Therefore, the probability of walruses encountering oil 
or waste products as a result of a spill from Industry activities is 
low. Onshore oil spills would not impact walruses unless they occurred 
on or near beaches or oil moved into the offshore environment. However, 
in the event of a spill that occurs during the open-water season, oil 
in the water column could drift offshore and possibly encounter a small 
number of walruses. Oil spills from offshore platforms could also 
contact walruses under certain conditions. For example, spilled oil 
during the ice-covered season that isn't cleaned up could become part 
of the ice substrate and could eventually be released back into the 
environment during the following open-water season. Additionally, 
during spring melt, oil would be collected by spill response 
activities, but it could eventually contact a limited number of 
walruses.
    Little is known about the effects of oil, specifically on walruses, 
as no studies have been conducted to date. Hypothetically, walruses may 
react to oil much like other pinnipeds. Walruses are not likely to 
ingest oil while grooming since walruses have very little hair and 
exhibit no grooming behavior. Adult walruses may not be severely 
affected by the oil spill through direct contact, but they will be 
extremely sensitive to any habitat disturbance by human noise and 
response activities. In addition, due to the gregarious nature of 
walruses, an oil spill would most likely affect multiple individuals in 
the area. Walruses may also expose themselves more often to the oil 
that has accumulated at the edge of a contaminated shore or ice lead if 
they repeatedly enter and exit the water.
    Walrus calves are most likely to suffer the ill-effects of oil 
contamination. Female walruses with calves are very attentive, and the 
calf will always stay close to its mother--including when the female is 
foraging for food. Walrus calves can swim almost immediately after 
birth and will often join their mother in the water. It is possible 
that an oiled calf will be unrecognizable to its mother either by sight 
or by smell and be abandoned. However, the greater threat may come from 
an oiled calf that is unable to swim away from the contamination and a 
devoted mother that would not leave without the calf, resulting in the 
potential mortality of both animals. Further, a nursing calf might 
ingest oil if the mother was oiled, also increasing the risk of injury 
or mortality.
    Walruses have thick skin and blubber layers for insulation. Heat 
loss is regulated by control of peripheral blood flow through the 
animal's skin and blubber. The peripheral blood flow is decreased in 
cold water and increased at warmer temperatures. Direct exposure of 
walruses to oil is not believed to have any effect on the insulating 
capacity of their skin and blubber, although it is unknown if oil could 
affect their peripheral blood flow.
    Damage to the skin of pinnipeds can occur from contact with oil 
because some of the oil penetrates the skin, causing inflammation and 
death of some tissue. The dead tissue is discarded, leaving behind an 
ulcer. While these skin lesions have only rarely been found on oiled 
seals, the effects on walruses may be greater because of a lack of hair 
to protect the skin. Direct exposure to oil can also result in 
conjunctivitis. Like other pinnipeds, walruses are susceptible to oil 
contamination in their eyes. Continuous exposure to oil will quickly 
cause permanent eye damage.
    Inhalation of hydrocarbon fumes presents another threat to marine 
mammals. In studies conducted on pinnipeds, pulmonary hemorrhage, 
inflammation, congestion, and nerve damage resulted after exposure to 
concentrated hydrocarbon fumes for a period of 24 hours. If the 
walruses were also under stress from molting, pregnancy, etc., the 
increased heart rate associated with the stress would circulate the 
hydrocarbons more quickly, lowering the tolerance threshold for 
ingestion or inhalation.
    Walruses are benthic feeders, and much of the benthic prey 
contaminated by an oil spill would be killed immediately. Others that 
survived would become contaminated from oil in bottom sediments, 
possibly resulting in slower growth and a decrease in reproduction. 
Bivalve mollusks, a favorite prey species of the walrus, are not 
effective at processing hydrocarbon compounds, resulting in highly 
concentrated accumulations and long-term retention of the contamination 
within the organism. Specifically, bivalve mollusks bioconcentrate 
polycyclic aromatic hydrocarbons (PAHs). These compounds are a 
particularly toxic fraction of oil that may cause a variety of chronic 
toxic effects in exposed organisms, including enzyme induction, immune 
impairment, or cancer, among others. In addition, because walruses feed 
primarily on mollusks, they may be more vulnerable to a loss of this 
prey species than other pinnipeds that feed on a larger variety of 
prey. Furthermore, complete recovery of a bivalve mollusk population 
may take 10 years or more, forcing walruses to find other food 
resources or move to nontraditional areas.
    The relatively few walruses in the Beaufort Sea and the low 
potential for a large oil spill (1,000 bbl or more), which is discussed 
in the following Risk Assessment Analysis, limit potential impacts to 
walruses to only certain events (i.e., a large oil spill), which is 
further limited to only a handful of individuals. Fueling crews have 
personnel that are trained to handle operational spills and contain 
them. If a small offshore spill occurs, spill response vessels are 
stationed in close proximity and respond immediately.

Polar Bear

    To date, large oil spills from Industry activities in the Beaufort 
Sea and coastal regions that would impact polar bears have not 
occurred, although the interest in and the development of offshore 
hydrocarbon reservoirs has increased the potential for large offshore 
oil spills. With limited background information available regarding oil 
spills in the Arctic environment, the outcome of such a spill is 
uncertain. For example, in the event of a large spill equal to a 
rupture in the Northstar pipeline and a complete drain of the subsea 
portion of the pipeline (approximately 5,900 bbl), oil would be 
influenced by seasonal weather and sea conditions including 
temperature, winds, wave action, and currents. Weather and sea 
conditions

[[Page 43035]]

also affect the type of equipment needed for spill response and the 
effectiveness of spill cleanup. Based on the experiences of cleanup 
efforts following the Exxon Valdez oil spill, where logistical support 
was readily available, spill response may be largely unsuccessful in 
open-water conditions. Indeed, spill response drills have been 
unsuccessful in the cleanup of oil in broken-ice conditions.
    Small spills of oil or waste products throughout the year have the 
potential to impact some bears. The effects of fouling fur or ingesting 
oil or wastes, depending on the amount of oil or wastes involved, could 
be short term or result in death. For example, in April 1988, a dead 
polar bear was found on Leavitt Island, northeast of Oliktok Point. The 
cause of death was determined to be a mixture that included ethylene 
glycol and Rhodamine B dye (Amstrup et al. 1989). Again, in 2012, two 
dead polar bears that had been exposed to Rhodamine B were found on 
Narwhal Island, northwest of Endicott. While those bears' deaths were 
clearly human-caused, investigations were unable to identify a source 
for the chemicals. Rhodamine B is commonly used on the North Slope of 
Alaska by many people for many uses, including Industry. Without 
identified sources of contamination, those bear deaths cannot be 
attributed to Industry activity.
    During the ice-covered season, mobile, non-denning bears would have 
a higher probability of encountering oil or other production wastes 
than non-mobile, denning females. Current management practices by 
Industry, such as requiring the proper use, storage, and disposal of 
hazardous materials, minimize the potential occurrence of such 
incidents. In the event of an oil spill, it is also likely that polar 
bears would be intentionally hazed to keep them away from the area, 
further reducing the likelihood of impacting the population.
    In 1980, Oritsland et al. (1981) performed experiments in Canada 
that studied the effects of oil exposure on polar bears. Effects on 
experimentally oiled bears (where bears were forced to remain in oil 
for prolonged periods of time) included acute inflammation of the nasal 
passages, marked epidermal responses, anemia, anorexia, and biochemical 
changes indicative of stress, renal impairment, and death. Many effects 
did not become evident until several weeks after the experiment.
    Oiling of the pelt causes significant thermoregulatory problems by 
reducing insulation value. Irritation or damage to the skin by oil may 
further contribute to impaired thermoregulation. Experiments on live 
polar bears and pelts showed that the thermal value of the fur 
decreased significantly after oiling, and oiled bears showed increased 
metabolic rates and elevated skin temperature. Oiled bears are also 
likely to ingest oil as they groom to restore the insulation value of 
the oiled fur.
    Oil ingestion by polar bears through consumption of contaminated 
prey, and by grooming or nursing, could have pathological effects 
depending on the amount of oil ingested and the individual's 
physiological state. Death could occur if a large amount of oil was 
ingested or if volatile components of oil were aspirated into the 
lungs. In the Canadian experiment (Ortisland et al. 1981), two of three 
bears died. A suspected contributing factor to their deaths was 
ingestion of oil. Experimentally oiled bears ingested large amounts of 
oil through grooming. Much of the oil was eliminated by vomiting and 
defecating; some was absorbed and later found in body fluids and 
tissues.
    Ingestion of sublethal amounts of oil can have various 
physiological effects on polar bears, depending on whether the animal 
is able to excrete or detoxify the hydrocarbons. Petroleum hydrocarbons 
irritate or destroy epithelial cells lining the stomach and intestine, 
thereby affecting motility, digestion, and absorption.
    Polar bears swimming in or walking adjacent to an oil spill could 
inhale toxic, volatile organic compounds from petroleum vapors. Vapor 
inhalation by polar bears could result in damage to the respiratory and 
central nervous systems depending on the amount of exposure.
    Oil may also affect food sources of polar bears. Seals that die as 
a result of an oil spill could be scavenged by polar bears. This food 
source would increase exposure of the bears to hydrocarbons and could 
result in lethal impacts or reduced survival to individual bears. A 
local reduction in ringed seal numbers as a result of direct or 
indirect effects of oil could temporarily affect the local distribution 
of polar bears. A reduction in density of seals as a direct result of 
mortality from contact with spilled oil could result in polar bears not 
using a particular area for hunting. Further, possible impacts from the 
loss of a food source could reduce recruitment and/or survival.
    Spilled oil can concentrate and accumulate in leads and openings 
that occur during spring break-up and autumn freeze-up periods. Such a 
concentration of spilled oil would increase the likelihood that polar 
bears and their principal prey would be oiled. To access ringed and 
bearded seals, polar bears in the SBS concentrate in shallow waters 
less than 300 m (984 ft) deep over the continental shelf and in areas 
with greater than 50 percent ice cover (Durner et al. 2004).
    Due to their seasonal use of nearshore habitat, the times of 
greatest impact from an oil spill to polar bears are likely the open-
water and broken-ice periods (summer and fall), extending into the ice-
covered season (Wilson et al. 2018). This scenario is important because 
distributions of polar bears are not uniform through time. Nearshore 
and offshore polar bear densities are greatest in fall, and polar bear 
use of coastal areas during the fall open-water period has increased in 
recent years in the Beaufort Sea. An analysis of data collected from 
the period 2001-2005 during the fall open-water period concluded: (1) 
On average approximately 4 percent of the estimated polar bears in the 
Southern Beaufort Sea stock were observed onshore in the fall; (2) 80 
percent of bears onshore occurred within 15 km (9 mi) of subsistence-
harvested bowhead whale carcasses, where large congregations of polar 
bears have been observed feeding; and (3) sea-ice conditions affected 
the number of bears on land and the duration of time they spent there 
(Schliebe et al. 2006). Hence, bears concentrated in areas where beach-
cast marine mammal carcasses occur during the fall would likely be more 
susceptible to oiling.
    Wilson et al. (2018) analyzed the potential effects of a ``worst 
case discharge'' (WCD) on polar bears in the Chukchi Sea. Their WCD 
scenario was based on an Industry oil spill response plan for offshore 
development in the region and represented underwater blowouts releasing 
25,000 bbls of crude oil per day for 30 days beginning in October. The 
results of this analysis suggested that between 5 and 40 percent of a 
stock of 2,000 polar bears in the Chukchi Sea could be exposed to oil 
if a WCD occurred. A similar analysis has not been conducted for the 
Beaufort Sea; however, given the extremely low probability (i.e., 
0.0001) that an unmitigated WCD event would occur (BOEM 2016, Wilson et 
al. 2017), the likelihood of such effects on polar bears in the 
Beaufort Sea is extremely low.
    The persistence of toxic subsurface oil and chronic exposures, even 
at sublethal levels, can have long-term effects on wildlife (Peterson 
et al. 2003). Exposure to PAHs can have chronic effects because some 
effects are sublethal (e.g., enzyme induction or

[[Page 43036]]

immune impairment) or delayed (e.g., cancer). Although it is true that 
some bears may be directly affected by spilled oil initially, the long-
term impact could be much greater. Long-term effects could be 
substantial through complex environmental interactions--compromising 
the health of exposed animals. For example, PAHs can impact the food 
web by concentrating in filter-feeding organisms, thus affecting fish 
that feed on those organisms, and the predators of those fish, such as 
the ringed seals that polar bears prey upon. How these complex 
interactions would affect polar bears is not well understood, but 
sublethal, chronic effects of an oil spill may affect the polar bear 
population due to reduced fitness of surviving animals.
    Polar bears are biological sinks for some pollutants, such as 
polychlorinated biphenyls or organochlorine pesticides, because polar 
bears are an apex predator of the Arctic ecosystem and are also 
opportunistic scavengers of other marine mammals. Additionally, their 
diet is composed mostly of high-fat sealskin and blubber (Norstrom et 
al. 1988). The highest concentrations of persistent organic pollutants 
in Arctic marine mammals have been found in seal-eating walruses and 
polar bears near Svalbard (Norstrom et al. 1988, Andersen et al. 2001, 
Muir et al. 1999). As such, polar bears would be susceptible to the 
effects of bioaccumulation of contaminants, which could affect their 
reproduction, survival, and immune systems.
    In addition, subadult polar bears are more vulnerable than adults 
to environmental effects (Taylor et al. 1987). Therefore, subadults 
would be most prone to the lethal and sublethal effects of an oil spill 
due to their proclivity for scavenging (thus increasing their exposure 
to oiled marine mammals) and their inexperience in hunting. Due to the 
greater maternal investment a weaned subadult represents, reduced 
survival rates of subadult polar bears have a greater impact on 
population growth rate and sustainable harvest than reduced litter 
production rates (Taylor et al. 1987).
    Evaluation of the potential impacts of spilled Industry waste 
products and oil suggest that individual bears could be adversely 
impacted by exposure to these substances (Oritsland et al. 1981). The 
major concern regarding a large oil spill is the impact such a spill 
would have on the rates of recruitment and survival of the SBS polar 
bear stock. Polar bear deaths from an oil spill could be caused by 
direct exposure to the oil. However, indirect effects, such as a 
reduction of prey or scavenging contaminated carcasses, could also 
cause health effects, death, or otherwise affect rates of recruitment 
and survival. Depending on the type and amount of oil or wastes 
involved and the timing and location of a spill, impacts could be 
acute, chronic, temporary, or lethal. For the rates of polar bear 
reproduction, recruitment, or survival to be impacted, a large-volume 
oil spill would have to take place. The following section analyzes the 
likelihood and potential effects of such a large-volume oil spill.

Risk Assessment of Potential Effects Upon Polar Bears From a Large Oil 
Spill in the Beaufort Sea

    In this section, we qualitatively assess the likelihood that polar 
bear populations on the North Slope may be affected by large oil 
spills. We considered: (1) The probability of a large oil spill 
occurring in the Beaufort Sea; (2) the probability of that oil spill 
impacting coastal polar bear habitat; (3) the probability of polar 
bears being in the area and coming into contact with that large oil 
spill; and (4) the number of polar bears that could potentially be 
impacted by the spill. Although most of the information in this 
evaluation is qualitative, the probability of all factors occurring 
sequentially in a manner that impacts polar bears in the Beaufort Sea 
is low. Since walruses are not often found in the Beaufort Sea, and 
there is little information available regarding the potential effects 
of an oil spill upon walruses, this analysis emphasizes polar bears.
    The analysis was based on polar bear distribution and habitat use 
using four sources of information that, when combined, allowed the 
Service to make conclusions on the risk of oil spills to polar bears. 
This information included: (1) The description of existing offshore oil 
and gas production facilities previously discussed in the Description 
of Activities section; (2) polar bear distribution information 
previously discussed in the Biological Information section; (3) BOEM 
Oil-Spill Risk Analysis (OSRA) for the OCS (Li and Smith 2020), 
including polar bear environmental resource areas (ERAs) and land 
segments (LSs); and (4) the most recent polar bear risk assessment from 
the previous ITRs.
    Development of offshore production facilities with supporting 
pipelines increases the potential for large offshore spills. The 
probability of a large oil spill from offshore oil and gas facilities 
and the risk to polar bears is a scenario that has been considered in 
previous regulations (71 FR 43926, August 2, 2006; 76 FR 47010, August 
3, 2011; 81 FR 52275, August 5, 2016). Although there is a slowly 
growing body of scientific literature (e.g., Amstrup et al. 2006, 
Wilson et al. 2017), the background information available regarding the 
effects of large oil spills on polar bears in the marine arctic 
environment is still limited, and thus the impact of a large oil spill 
is uncertain. As far as is known, polar bears have not been affected by 
oil spilled as a result of North Slope Industry activities.
    The oil-spill scenarios for this analysis include the potential 
impacts of a large oil spill (i.e., 1,000 bbl or more) from one of the 
offshore Industry facilities: Northstar, Spy Island, Oooguruk, 
Endicott, or the future Liberty. Estimating a large oil-spill 
occurrence is accomplished by examining a variety of factors and 
associated uncertainty, including location, number, and size of a large 
oil spill and the wind, ice, and current conditions at the time of a 
spill.

BOEM Oil Spill Risk Analysis

    Because the BOEM OSRA provides the most current and rigorous 
treatment of potential oil spills in the Beaufort Sea Planning Area, 
our analysis of potential oil spill impacts applied the results of 
BOEM's OSRA (Li and Smith 2020) to help analyze potential impacts of a 
large oil spill originating in the Beaufort Sea ITR region to polar 
bears. The OSRA quantitatively assesses how and where large offshore 
spills will likely move by modeling effects of the physical 
environment, including wind, sea-ice, and currents, on spilled oil. 
(Smith et al. 1982, Amstrup et al. 2006a).
    A previous OSRA estimated that the mean number of large spills is 
less than one over the 20-year life of past, present, and reasonably 
foreseeable developments in the Beaufort Sea Planning Area (Johnson et 
al. 2002). In addition, large spills are more likely to occur during 
development and production than during exploration in the Arctic (MMS 
2008). Our oil spill assessment during a 5-year regulatory period is 
predicated on the same assumptions.
Trajectory Estimates of Large Offshore Oil Spills
    Although it is reasonable to conclude that the chance of one or 
more large spills occurring during the period of these regulations on 
the Alaskan OCS from production activities is low, for analysis 
purposes, we assume that a large spill does occur in order to evaluate 
potential impacts to polar bears. The BOEM OSRA modeled the 
trajectories of 3,240 oil spills from 581

[[Page 43037]]

possible launch points in relation to the shoreline and biological, 
physical, and sociocultural resource areas specific to the Beaufort 
Sea. The chance that a large oil spill will contact a specific ERA of 
concern within a given time of travel from a certain location (launch 
area or pipeline segment) is termed a ``conditional probability.'' 
Conditional probabilities assume that no cleanup activities take place 
and there are no efforts to contain the spill.
    We used two BOEM launch areas (LAs), LA 2 and LA 3, and one 
pipeline segment (PL), PL 2, from Appendix A of the OSRA (Figure A-2; 
Li and Smith 2020) to represent the oil spills moving from hypothetical 
offshore areas. These LAs and PLs were selected because of their 
proximity to current and proposed offshore facilities.
Oil-Spill-Trajectory Model Assumptions
    For purposes of its oil spill trajectory simulation, BOEM made the 
following assumptions: All spills occur instantaneously; large oil 
spills occur in the hypothetical origin areas or along the hypothetical 
PLs noted above; large spills do not weather (i.e., become degraded by 
weather conditions) for purposes of trajectory analysis; weathering is 
calculated separately; the model does not simulate cleanup scenarios; 
the oil spill trajectories move as though no oil spill response action 
is taken; and large oil spills stop when they contact the mainland 
coastline.
Analysis of the Conditional Probability Results
    As noted above, the chance that a large oil spill will contact a 
specific ERA of concern within a given time of travel from a certain 
location (LA or PL), assuming a large spill occurs and that no cleanup 
takes place, is termed a ``conditional probability.'' From the OSRA, 
Appendix B, we chose ERAs and land segments (LSs) to represent areas of 
concern pertinent to polar bears (MMS 2008a). Those ERAs and LSs and 
the conditional probabilities that a large oil spill originating from 
the selected LAs or PLs could affect those ERAs and LSs are presented 
in a supplementary table titled ``Conditional Oil Spill Probabilities'' 
that can be found on http://www.regulations.gov under Docket No. FWS-
R7-ES-2021-0037. From the information in this table, we note the 
highest chance of contact and the range of chances of contact that 
could occur should a large spill occur from LAs or PLs.
    Polar bears are vulnerable to a large oil spill during the open-
water period when bears form aggregations onshore. In the Beaufort Sea, 
these aggregations often form in the fall near subsistence-harvested 
bowhead whale carcasses. Specific aggregation areas include Point 
Utqigvik, Cross Island, and Kaktovik. In recent years, more than 60 
polar bears have been observed feeding on whale carcasses just outside 
of Kaktovik, and in the autumn of 2002, North Slope Borough and Service 
biologists documented more than 100 polar bears in and around Utqigvik. 
In order for significant impacts to polar bears to occur, (1) a large 
oil spill would have to occur, (2) oil would have to contact an area 
where polar bears aggregate, and (3) the aggregation of polar bears 
would have to occur at the same time as the spill. The risk of all 
three of these events occurring simultaneously is low.
    We identified polar bear aggregations in environmental resource 
areas and non-grouped land segments (ERA 55, 93, 95, 96, 100; LS 85, 
102, 107). The OSRA estimates the chance of contacting these 
aggregations is 18 percent or less (see Table 1, ``Conditional Oil 
Spill Probabilities,'' in the Supporting and Related Material in Docket 
No. FWS-R7-ES-2021-0037). The OSRA estimates for LA 2 and LA 3 have the 
highest chance of a large spill contacting ERA 96 in summer (Midway, 
Cross, and Bartlett islands). Some polar bears will aggregate at these 
islands during August-October (3-month period). If a large oil spill 
occurred and contacted those aggregation sites outside of the timeframe 
of use by polar bears, potential impacts to polar bears would be 
reduced.
    Coastal areas provide important denning habitat for polar bears, 
such as the ANWR and nearshore barrier islands (containing tundra 
habitat) (Amstrup 1993, Amstrup and Gardner 1994, Durner et al. 2006, 
USFWS unpubl. data). Considering that 65 percent of confirmed 
terrestrial dens found in Alaska in the period 1981-2005 were on 
coastal or island bluffs (Durner et al. 2006), oiling of such habitats 
could have negative effects on polar bears, although the specific 
nature and ramifications of such effects are unknown.
    Assuming a large oil spill occurs, tundra relief barrier islands 
(ERA 92, 93, and 94, LS 97 and 102) have up to an 18 percent chance of 
a large spill contacting them from PL 2. The OSRA estimates suggest 
that there is a 12 percent chance that oil would contact the coastline 
of the ANWR (GLS 166). The Kaktovik area (ERA 95 and 100, LS 107) has 
up to a one percent chance of a spill contacting the coastline. The 
chance of a spill contacting the coast near Utqiagvik (ERA 55, LS 85) 
would be as high as 15 percent (see Table 1, ``Conditional Oil Spill 
Probabilities,'' in the Supporting and Related Material in Docket No. 
FWS-R7-ES-2021-0037).
    All barrier islands are important resting and travel corridors for 
polar bears, and larger barrier islands that contain tundra relief are 
also important denning habitat. Tundra-bearing barrier islands within 
the geographic region and near oilfield development are the Jones 
Island group of Pingok, Bertoncini, Bodfish, Cottle, Howe, Foggy, 
Tigvariak, and Flaxman Islands. In addition, Cross Island has gravel 
relief where polar bears have denned. The Jones Island group is located 
in ERA 92 and LS 97. If a spill were to originate from an LA 2 pipeline 
segment during the summer months, the probability that this spill would 
contact these land segments could be as great as 15 percent. The 
probability that a spill from LA 3 would contact the Jones Island group 
would range from 1 percent to as high as 12 percent. Likewise, for PL 
2, the range would be from 3 percent to as high as 12 percent.

Risk Assessment From Prior ITRs

    In previous ITRs, we used a risk assessment method that considered 
oil spill probability estimates for two sites (Northstar and Liberty), 
oil spill trajectory models, and a polar bear distribution model based 
on location of satellite-collared females during September and October 
(68 FR 66744, November 28, 2003; 71 FR 43926, August 2, 2006; 76 FR 
47010, August 3, 2011; and 81 FR 52275, August 5, 2016). To support the 
analysis for this action, we reviewed the previous analysis and used 
the data to compare the potential effects of a large oil spill in a 
nearshore production facility (less than 5 mi), such as Liberty, and a 
facility located further offshore, such as Northstar. Even though the 
risk assessment of 2006 did not specifically model spills from the 
Oooguruk or Nikaitchuq sites, we believe it was reasonable to assume 
that the analysis for Liberty and indirectly, Northstar, adequately 
reflected the potential impacts likely to occur from an oil spill at 
either of these additional locations due to the similarity in the 
nearshore locations.
Methodology of Prior Risk Assessment
    The first step of the risk assessment analysis was to examine oil 
spill probabilities at offshore production sites for the summer (July-
October) and winter (November-June) seasons based on information 
developed for the original Northstar and Liberty EISs. We assumed that 
one large spill occurred during the 5-year period covered by the 
regulations. A detailed description of the methodology can be found at 
71 FR

[[Page 43038]]

43926 (August 2, 2006). The second step in the risk assessment was to 
estimate the number of polar bears that could be impacted by a large 
spill. All modeled polar bear grid cell locations that were intersected 
by one or more cells of a rasterized spill path (a modeled group of 
hundreds of oil particles forming a trajectory and pushed by winds and 
currents and impeded by ice) were considered ``oiled'' by a spill. For 
purposes of the analysis, if a bear contacted oil, the contact was 
assumed to be lethal. This analysis involved estimating the 
distribution of bears that could be in the area and overlapping polar 
bear distributions and seasonal aggregations with oil spill 
trajectories. The trajectories previously calculated for Northstar and 
Liberty sites were used. The trajectories for Northstar and Liberty 
were provided by the BOEM and were reported in Amstrup et al. (2006a). 
BOEM estimated probable sizes of oil spills from a pinhole leak to a 
rupture in the transportation pipeline. These spill sizes ranged from a 
minimum of 125 to a catastrophic release event of 5,912 bbl. 
Researchers set the size of the modeled spill at the scenario of 5,912 
bbl caused by a pinhole or small leak for 60 days under ice without 
detection.
    The second step of the risk assessment analysis incorporated polar 
bear densities overlapped with the oil spill trajectories. To 
accomplish this, in 2004, USGS completed an analysis investigating the 
potential effects of hypothetical oil spills on polar bears. Movement 
and distribution information were derived from radio and satellite 
locations of collared adult females. Density estimates were used to 
determine the distribution of polar bears in the Beaufort Sea. 
Researchers then created a grid system centered over the Northstar 
production island and the Liberty site to estimate the number of bears 
expected to occur within each 1-km\2\ grid cell. Each of the simulated 
oil spills were overlaid with the polar bear distribution grid. 
Finally, the likelihood of occurrence of bears oiled during the 
duration of the 5-year ITRs was estimated. This likelihood was 
calculated by multiplying the number of polar bears oiled by the spill 
by the percentage of time bears were at risk for each period of the 
year.
    In summary, the maximum numbers of bears potentially oiled by a 
5,912-bbl spill during the September open-water season from Northstar 
was 27, and the maximum from Liberty was 23, assuming a large oil spill 
occurred and no cleanup or mitigation measures took place. Potentially 
oiled polar bears ranged up to 74 bears with up to 55 bears during 
October in mixed-ice conditions for Northstar and Liberty, 
respectively. Median number of bears oiled by the 5,912-bbl spill from 
the Northstar simulation site in September and October were 3 and 11 
bears, respectively. Median numbers of bears oiled from the Liberty 
simulation site for September and October were 1 and 3 bears, 
respectively. Variation occurred among oil spill scenarios, resulting 
from differences in oil spill trajectories among those scenarios and 
not the result of variation in the estimated bear densities. For 
example, in October, 75 percent of trajectories from the 5,912-bbl 
spill affected 20 or fewer polar bears from spills originating at the 
Northstar simulation site and 9 or fewer bears from spills originating 
at the Liberty simulation site.
    When calculating the probability that a 5,912-bbl spill would oil 
five or more bears during the annual fall period, we found that oil 
spills and trajectories were more likely to affect fewer than five 
bears versus more than five bears. Thus, for Northstar, the chance that 
a 5,912-bbl oil spill affected (resulting in mortality) 5 or more bears 
was 1.0-3.4 percent; 10 or more bears was 0.7-2.3 percent; and 20 or 
more bears was 0.2-0.8 percent. For Liberty, the probability of a spill 
that would affect 5 or more bears was 0.3-7.4 percent; 10 or more 
bears, 0.1-0.4 percent; and 20 or more bears, 0.1-0.2 percent.
Discussion of Prior Risk Assessment
    Based on the simulations, a nearshore island production site (less 
than 5 mi from shore) would potentially involve less risk of polar 
bears being oiled than a facility located farther offshore (greater 
than 5 mi). For any spill event, seasonality of habitat use by bears 
will be an important variable in assessing risk to polar bears. During 
the fall season when a portion of the SBS bear stock aggregate on 
terrestrial sites and use barrier islands for travel corridors, spill 
events from nearshore industrial facilities may pose more chance of 
exposing bears to oil due to its persistence in the nearshore 
environment. Conversely, during the ice-covered and summer seasons, 
Industry facilities located farther offshore (greater than 5 mi) may 
increase the chance of bears being exposed to oil as bears will be 
associated with the ice habitat.

Conclusion of Risk Assessment

    To date, documented oil spill-related impacts in the marine 
environment to polar bears in the Beaufort Sea by the oil and gas 
Industry are minimal. No large spills by Industry in the marine 
environment have occurred in Arctic Alaska. Nevertheless, the 
possibility of oil spills from Industry activities and the subsequent 
impacts on polar bears that contact oil remain a major concern.
    There has been much discussion about effective techniques for 
containing, recovering, and cleaning up oil spills in Arctic marine 
environments, particularly the concern that effective oil spill cleanup 
during poor weather and broken-ice conditions has not been proven. 
Given this uncertainty, limiting the likelihood of a large oil spill 
becomes an even more important consideration. Industry oil spill 
contingency plans describe methodologies put in place to prevent a 
spill from occurring. For example, all current offshore production 
facilities have spill containment systems in place at the well heads. 
In the event an oil discharge should occur, containment systems are 
designed to collect the oil before it makes contact with the 
environment.
    With the limited background information available regarding oil 
spills in the Arctic environment, it is unknown what the outcome of 
such a spill event would be if one were to occur. For example, polar 
bears could encounter oil spills during the open-water and ice-covered 
seasons in offshore or onshore habitat. Although most polar bears in 
the SBS stock spend a large amount of their time offshore on the pack 
ice, it is likely that some bears would encounter oil from a large 
spill that persisted for 30 days or more.
    An analysis of the potential effects of a ``worst case discharge'' 
(WCD) on polar bears in the Chukchi Sea suggested that between 5 and 40 
percent of a stock of 2,000 polar bears could be exposed to oil if a 
WCD occurred (Wilson et al. 2017). A similar analysis has not been 
conducted for the Beaufort Sea; however, given the extremely low 
probability (i.e., 0.0001) that an unmitigated WCD event would occur 
(BOEM 2015, Wilson et al. 2017), the likelihood of such effects on 
polar bears in the Beaufort Sea is extremely low.
    Although the extent of impacts from a large oil spill would depend 
on the size, location, and timing of spills relative to polar bear 
distributions along with the effectiveness of spill response and 
cleanup efforts, under some scenarios, stock-level impacts could be 
expected. A large spill originating from a marine oil platform could 
have significant impacts on polar bears if an oil spill contacted an 
aggregation of polar bears. Likewise, a spill occurring during the 
broken-ice period could significantly impact the SBS polar bear stock 
in part because polar bears may be more active during this season.

[[Page 43039]]

    If an offshore oil spill contaminated numerous bears, a potentially 
significant impact to the SBS stock could result. This effect would be 
magnified in and around areas of polar bear aggregations. Bears could 
also be affected indirectly either by food contamination or by chronic 
lasting effects caused by exposure to oil. During the 5-year period of 
these regulations, however, the chance of a large spill occurring is 
low.
    While there is uncertainty in the analysis, certain factors must 
align for polar bears to be impacted by a large oil spill occurring in 
the marine environment. First, a large spill must occur. Second, the 
large spill must contaminate areas where bears may be located. Third, 
polar bears must be seasonally distributed within the affected region 
when the oil is present. Assuming a large spill occurs, BOEM's OSRA 
estimated that there is up to a 6 percent chance that a large spill 
from the analyzed sites would contact Cross Island (ERA 96) within 360 
days, as much as a 12 percent chance that it would contact Barter 
Island and/or the coast of the ANWR (ERA 95 and 100, LS 107, and GLS 
166), and up to a 15 percent chance that an oil spill would contact the 
coast near Utqigvik (ERA 55, LS 85) during the summer time period. Data 
from polar bear coastal surveys indicate that polar bears are unevenly 
and seasonally distributed along the coastal areas of the Beaufort Sea 
ITR region. Seasonally, only a portion of the SBS stock utilizes the 
coastline between the Alaska-Canada border and Utqiagvik and only a 
portion of those bears could be in the oil-spill-affected region.
    As a result of the information considered here, the Service 
concludes that the likelihood of an offshore spill from an offshore 
production facility in the next 5 years is low. Moreover, in the 
unlikely event of a large spill, the likelihood that spills would 
contaminate areas occupied by large numbers of bears is low. While 
individual bears could be negatively affected by a spill, the potential 
for a stock-level effect is low unless the spill contacted an area 
where large numbers of polar bears were gathered. Known polar bear 
aggregations tend to be seasonal during the fall, further minimizing 
the potential of a spill to impact the stock. Therefore, we conclude 
that the likelihood of a large spill occurring is low, but if a large 
spill does occur, the likelihood that it would contaminate areas 
occupied by large numbers of polar bears is also low. If a large spill 
does occur, we conclude that only small numbers of polar bears are 
likely to be affected, though some bears may be killed, and there would 
be only a negligible impact to the SBS stock.

Take Estimates for Pacific Walruses and Polar Bears

Small Numbers Determinations and Findings

    The following analysis concludes that only small numbers of 
walruses and polar bears are likely to be subjected to take incidental 
to the described Industry activities relative to their respective 
stocks. For our small numbers determination, we consider whether the 
estimated number of marine mammals to be subjected to incidental take 
is small relative to the population size of the species or stock.
    1. The estimated number of walruses and polar bears that will be 
harassed by Industry activity is small relative to the number of 
animals in their stocks.
    As stated previously, walruses are extralimital in the Beaufort Sea 
with nearly the entire walrus population found in the Chukchi and 
Bering Seas. Industry monitoring reports have observed no more than 38 
walruses between 1995 and 2015, with only a few observed instances of 
disturbance to those walruses (AES Alaska 2015, USFWS unpublished 
data). Between those years, Industry walrus observations in the 
Beaufort Sea ITR region averaged approximately two walruses per year, 
although the actual observations were of a single or two animals, often 
separated by several years. At most, only a tiny fraction of the 
Pacific walrus population--which is comprised of hundreds of thousands 
of animals--may be found in areas potentially affected by AOGA's 
specified activities. We do not anticipate that seasonal movements of a 
few walruses into the Beaufort Sea will significantly increase over the 
5-year period of this ITR. The estimated take of 15 Pacific walruses 
per year from a population numbering approximately 283,213 animals 
represents 0.005 percent of that population. We therefore find that the 
Industry activities specified in AOGA's Request would result in only a 
small number of incidental harassments of walruses.
    The Beaufort Sea ITR region is completely within the range of the 
SBS stock of polar bears, and during some portions of the year polar 
bears can be frequently encountered by Industry. From 2014 through 
2018, Industry made 1,166 reports of polar bears comprising 1,698 
bears. However, when we evaluated the effects upon the 1,698 bears 
observed, we found that 84 percent (1,434) did not result in take. Over 
those 5 years, Level B harassments of polar bears totaled 264, 
approximately 15.5 percent of the observed bears. No other forms of 
take or harassment were observed. Annually an average of 340 polar 
bears were observed during Industry activities. The number of Level B 
harassment events has averaged 53 per year from 2014 to 2018. We 
conclude that over the 5-year period of this ITR, Industry activities 
will result in a similarly small number of incidental harassments of 
polar bears, and that those events will be similarly limited to Level B 
harassment.
    Based on this information derived from Industry observations, along 
with the results of the Service's own predictive modeling analysis 
described above, we estimate that there will be no more than 443 Level 
B harassment takes of polar bears during the 5-year period of this ITR, 
with no more than 92 occurring within a single year. Conservatively 
assuming that each estimates take will accrue to a different individual 
polar bear, we note that take of 92 animals is 10.14 percent of the 
best available estimate of the current stock size of 907 animals in the 
Southern Beaufort Sea stock (Bromaghin et al. 2015, Atwood et al. 2020) 
((92 / 907) x 100 [ap] 10.14), and find that this proportion represents 
a ``small number'' of polar bears of that stock. The incidental Level B 
harassment of no more than 92 polar bears each year is unlikely to lead 
to significant consequences for the health, reproduction, or survival 
of affected animals. All takes are anticipated to be incidental Level B 
harassment involving short-term and temporary changes in bear behavior. 
The required mitigation and monitoring measures described in the 
regulations are expected to prevent any lethal or injurious takes.
    2. Within the specified geographical region, the area of Industry 
activity is expected to be small relative to the range of walruses and 
polar bears.
    Walruses and polar bears range well beyond the boundaries of the 
Beaufort Sea ITR region. As such, the ITR region itself represents only 
a subset of the potential area in which these species may occur. 
Further, only seven percent of the ITR area (518,800 ha of 7.9 million 
ha) is estimated to be impacted by the proposed Industry activities, 
even accounting for a disturbance zone surrounding industrial facility 
and transit routes. Thus, the Service concludes that the area of 
Industry activity will be relatively small compared to the range of 
walruses and polar bears.

[[Page 43040]]

Conclusion
    We expect that only small numbers of Pacific walruses and SBS polar 
bears stocks would be taken by the Industry activities specified in 
AOGA's Request because: (1) Walruses are extralimital in the Beaufort 
Sea and SBS polar bears are widely distributed throughout their 
expansive range, which encompasses areas beyond the Beaufort Sea ITR 
region, meaning only a small proportion of the walrus or polar bear 
stocks will occur in the areas where Industry activities will occur; 
and (2) the estimated number of walruses and polar bears that could be 
impacted by the specified activities is small relative the size of the 
species (walruses) or stock (polar bears).

Negligible Impacts Determination and Finding

    Based on the best scientific information available, the results of 
Industry monitoring data from the previous ITRs, the review of the 
information generated by the listing of the polar bear as a threatened 
species and the designation of polar bear critical habitat, the results 
of our modeling assessments, and the status of the species and stocks, 
we find that the incidental take we have estimated to occur and 
authorize through this ITR will have no more than a negligible impact 
on walruses and polar bears. We do not expect that the total of these 
disturbances will individually or collectively affect rates of 
recruitment or survival for walruses or polar bears. Factors considered 
in our negligible impacts determination include:
    1. The behavior and distribution of walruses and polar bears in 
areas that overlap with Industry activities are expected to limit 
interactions of walruses and polar bears with those activities.
    The distribution and habitat use patterns of walruses and polar 
bears indicate that relatively few animals will occur in the proposed 
areas of Industry activity at any particular time, and therefore, few 
animals are likely to be affected. As discussed previously, only small 
numbers of walruses are likely to be found in the Beaufort Sea where 
and when offshore Industry activities are proposed. Likewise, SBS polar 
bears are widely distributed across a range that is much greater than 
the geographic scope of the ITR, are most often closely associated with 
pack ice, and are unlikely to interact with the open water industrial 
activities specified in AOGA's Request, much less the majority of 
activities that would occur onshore.
    2. The predicted effects of Industry activities on walruses and 
polar bears will be incidental nonlethal, temporary takes of animals.
    The documented impacts of previous Industry activities on walruses 
and polar bears, taking into consideration cumulative effects, suggests 
that the types of activities analyzed for this ITR will have minimal 
effects and will be short-term, temporary behavioral changes. The vast 
majority of reported polar bear observations have been of polar bears 
moving through the Beaufort Sea ITR region, undisturbed by the Industry 
activity.
    3. The footprint of the proposed Industry activities is expected to 
be small relative to the range of the walrus and polar bear stocks.
    The relatively small area of Industry activity compared to the 
ranges of walruses and polar bears will reduce the potential of their 
exposure to and disturbance from Industry activities.
    4. The type of harassment that is estimated is not expected to have 
effects on annual rates of recruitment of survival.
    The Service does not anticipate any lethal or injurious take that 
would remove individual polar bears or Pacific walruses from the 
population or prevent their successful reproduction. In fact, the 
majority of the Service's model runs result in no serious injury Level 
A harassment or lethal takes and the median of the model runs is 0.0. 
Level B harassment events lead only to short-term, non-injurious 
behavioral disturbances that do not reduce the affected animals' 
probability of surviving or reproducing. These disturbances would not, 
therefore, affect the rates of recruitment or survival for the walrus 
and polar bear stocks. These regulations do not authorize lethal take, 
and we do not anticipate any lethal take will occur.
    5. Mitigation measures will limit potential effects of Industry 
activities.
    Under this regulation, holders of an LOA will be required to adopt 
monitoring requirements and mitigation measures designed to reduce the 
potential impacts of their operations on walruses and polar bears. 
Seasonal restrictions, early detection monitoring programs, den 
detection surveys for polar bears, and adaptive mitigation and 
management responses based on real-time monitoring information 
(described in these regulations) will be used to avoid or minimize 
interactions with walruses and polar bears and, therefore, limit 
potential Industry disturbance of these animals.
    In making this finding, we considered the following: The 
distribution of the species; the biological characteristics of the 
species; the nature of Industry activities; the potential effects of 
Industry activities and potential oil spills on the species; the 
probability of oil spills occurring; the documented impacts of Industry 
activities on the species, taking into consideration cumulative 
effects; the potential impacts of climate change, where both walruses 
and polar bears can potentially be displaced from preferred habitat; 
mitigation measures designed to minimize Industry impacts through 
adaptive management; and other data provided by Industry monitoring 
programs in the Beaufort and Chukchi Seas.
    We also considered the specific Congressional direction in 
balancing the potential for a significant impact with the likelihood of 
that event occurring. The Service has previously explained that 
Congressional direction that justifies balancing probabilities with 
impacts follows:

    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 Service 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 (53 FR 8474, March 15, 1988; accord 132 Cong. 
Rec. S 16305 (October. 15, 1986)).

    We reviewed the effects of the oil and gas Industry activities on 
walruses and polar bears, including impacts from surface interactions, 
aircraft overflights, maritime activities, and oil spills. Based on our 
review of these potential impacts, past LOA monitoring reports, and the 
biology and natural history of walrus and polar bear, we conclude that 
any incidental take reasonably likely to occur as a result of projected 
activities will be limited to short term behavioral disturbances that 
would not affect the rates of recruitment or survival for the walrus 
and polar bear stocks. This regulation does not authorize lethal take, 
and we do not anticipate any lethal take will occur.
    The probability of an oil spill that will cause significant impacts 
to walruses and polar bears appears extremely low. We have included 
information from both offshore and onshore projects in our oil spill 
analysis. We have analyzed the likelihood of a marine oil spill of the 
magnitude necessary to lethally take a

[[Page 43041]]

significant number of polar bears for offshore projects and, through a 
risk assessment analysis, found that it is unlikely that there will be 
any lethal take associated with a release of oil. In the unlikely event 
of a catastrophic spill, we will take immediate action to minimize the 
impacts to these species and reconsider the appropriateness of 
authorizations for incidental taking through section 101(a)(5)(A) of 
the MMPA.
    We have evaluated climate change regarding walruses and polar 
bears. Climate change is a global phenomenon and was considered as the 
overall driver of effects that could alter walrus and polar bear 
habitat and behavior. Although climate change is a pressing 
conservation issue for walruses and polar bears, we have concluded that 
the authorized taking of walruses and polar bears during the activities 
proposed by Industry during this 5-year rule will not adversely impact 
the survival of these species and will have no more than negligible 
effects.
Conclusion
    We find that the impacts of these specified activities cannot be 
reasonably expected to, and are not reasonably likely to, adversely 
affect Pacific walrus or SBS polar bears through effects on annual 
rates of recruitment or survival. We therefore find that the total of 
the taking estimated above and authorized by this ITR will have a 
negligible impact on Pacific walrus and SBS polar bears. These 
regulations do not authorize lethal take, and we do not anticipate that 
any lethal take will occur.

Least Practicable Adverse Impacts

    We evaluated the practicability and effectiveness of mitigation 
measures based on the nature, scope, and timing of Industry activities; 
the best available scientific information; and monitoring data during 
Industry activities in the specified geographic region. We have 
determined that the mitigation measures included within AOGA's 
Request--plus one additional mitigation measure noted below--will 
ensure the least practicable adverse impacts on polar bears and Pacific 
walruses (AOGA 2021).
    AOGA's initial request reflected the mitigation measures identified 
in prior Beaufort Sea ITRs as necessary to effect the least practicable 
adverse impact on Pacific walrus and SBS polar bears. The Service also 
collaborated extensively with AOGA concerning prior iterations of its 
Request in order to identify additional effective and practicable 
mitigation measures, which AOGA then incorporated into its final 
Request. Polar bear den surveys before activities begin during the 
denning season, and the resulting 1.6-km (1-mi) operational exclusion 
zone around all 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 time. In addition to conducting den detection 
surveys, during seismic operations, AOGA will use advance crews that 
use denning habitat maps and trained observers to scout for potential 
denning habitat including deep snow and steep bluffs in order to 
increase avoidance of these areas. Minimum flight elevations over polar 
bear areas and flight restrictions around known polar bear dens would 
reduce the potential for bears to be disturbed by aircraft. 
Additionally, during certain vessel based operations, or while 
conducting significant activities along to the coast that could 
introduce sound into the marine environment, AOGA will use trained 
protected species observers to alert crews when Pacific walruses or 
polar bears are in the vicinity. If they observe Pacific walruses or 
polar bears, they will shut down, reduce, or modify activities as 
needed to mitigate potential impacts. Protected species observers may 
also be required by the Service for use during other activities 
including aircraft operations or surface operations to also reduce 
potential impacts. Finally, AOGA will implement mitigation measures to 
prevent the presence and impact of attractants such as the use of 
wildlife-resistant waste receptacles and enclosing access doors and 
stairs. These measures will be outlined in polar bear and walrus 
interaction plans that are developed in coordination with the Service 
prior to starting activities. Based on the information we currently 
have regarding den and aircraft disturbance and polar bear attractants, 
we concluded that the mitigation measures outlined in AOGA's Request 
(AOGA 2021) and incorporated into this final rule will practically and 
effectively minimize disturbance from the specified oil and gas 
activities.
    The only additional mitigation measure not already included in 
AOGA's request but warranted to effect the least practicable adverse 
impact on polar bears and walruses is the requirement that aircraft 
operations within the ITR area will maintain an altitude of 1,500 ft 
above ground level when safe and operationally possible. Whereas AOGA's 
request committed to fly at such levels under ideal conditions, and the 
Proposed ITR stated that aircraft ``should'' fly at such levels when 
safe and operationally possible, this Final Rule replaces the Proposed 
Rule's use of ``should'' with ``will''. The Service determined that 
this revision could further reduce the extent to which aircraft are 
permitted to fly below 1,500 ft above ground level and thus further 
minimizes potential disturbances to polar bears and walruses while 
preserving safety and continuity of operations at minimal to no extra 
cost.
    A number of additional mitigation measures were considered but 
determined not to be practicable means of reducing impacts. These 
measures are listed below:
     Required use of helicopters for AIR surveys--Use of 
helicopters to survey active dens might actually lead to greater levels 
of disturbance and take compared to fixed-wing aircraft. Additionally, 
there have been no published data to indicate increased den detection 
efficacy of helicopter AIR.
     Grounding all flights if they must fly below 1,500 feet--
Requiring all aircraft to maintain an altitude of 1,500 ft is not 
practicable as some necessary operations may require flying below 1,500 
ft in order to perform inspections or maintain safety of flight crew.
     Spatial and temporal restrictions on surface activity--
Some spatial and temporal restrictions of operations were included in 
the ITR as a result of the Service's collaboration with the applicant, 
but it was made clear during that process additional restrictions would 
not be practicable for oil and gas operations based on other regulatory 
and safety requirements.
     One mile buffer around all known polar bear denning 
habitat--One mile buffer around all known polar bear denning habitat is 
not practicable as many existing operations occur within denning 
habitat and it would not be able to shut down all operations based on 
other regulatory and safety requirements.
     Restriction of vessel speed to 10 knots or less--
Restricting the speed of all industry vessels to 10 knots or less is 
not practicable for safe and efficient operations. The Service analyzed 
take of walruses and polar bears for in-water activities within a 1-
mile radius around a vessel at operational vessel speeds. Restricting 
vessel speeds unnecessarily will result in vessels spending more time 
in the water and it will increase the likelihood that marine mammals 
will be exposed to vessel disturbance for a longer period of time.
     Requirements for pile driving sound mitigation--Additional 
mitigation measures to reduce in-water sound were not required as the 
area of sound propagation would not extend beyond

[[Page 43042]]

the impact area for visual disturbance that is already included in the 
analysis. Therefore, there is no additional mitigative benefit to 
requiring this measure.
     Prohibition of driving over high relief areas, 
embankments, or stream and river crossings--While the denning habitat 
must be considered in tundra travel activities, complete prohibition of 
travel across such areas is not practicable because it would preclude 
necessary access to various operational areas and pose potential safety 
concerns. Moreover, not all high relief areas, embankments, and stream 
and river crossing constitute suitable polar bear denning habitat.
     Use of a broader definition of ``denning habitat'' for 
operational offsets--There is no available data to support broadening 
the defining features of denning habitat beyond that established by 
USGS. Such a redefinition would cause an increase in the area surveyed 
for maternal dens and increase potential harassment of bears on the 
surface.
     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 ITR 
area would be highly speculative. Therefore, there would be no 
mitigative benefit realized by their establishment.
     Requirement of third-party neutral marine mammal 
observers--It is often not practicable to hire third-party marine 
mammal observers due to operational constraints. Additional crew may 
require additional transit vehicles, which could increase disturbance.
     Require all activities to cease if a polar bear or walrus 
is injured or killed until an investigation is completed--The Service 
has incorporated into this rule reporting requirements for all polar 
bear and Pacific walrus interactions. While it may aid in any 
subsequent investigation, ceasing activities in an active oil field may 
not be practicable or safe in certain circumstances, and thus will not 
be mandated.
     Require use of den detection dogs-- It is not practicable 
to require scent trained dogs to detect dens due to the large spatial 
extent that would need to be surveyed each year.
     Require the use of handheld or vehicle-mounted FLIR--The 
efficacy rates for AIR has 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. While use of handheld or 
vehicle-mounted FLIR could increase the potential of detecting active 
dens in some circumstances, in other circumstances these potential 
benefits could be outweighed by the additional disturbances created by 
increasing vehicle use or human presence in the vicinity of dens. The 
safety of personnel tasked to prolong their presence in such areas is 
also an important consideration. The Service therefore finds that use 
of such techniques should remain at the discretion of operators on a 
case-by-case basis.

Impacts on Subsistence Uses

    We based our findings on past experience, requirements concerning 
community consultations through the Plan of Cooperation (POC) process, 
the limited anticipated overlap of hunting areas and Industry projects, 
the best scientific information available, anticipated 5-year effects 
of Industry activities on subsistence hunting, and the results of 
monitoring data and the Service's Marking, Tagging, and Reporting 
Program. Through these data, we find that any incidental harassment 
that may result from oil and gas exploration, development, and 
production activities in the specified geographic region will not have 
an unmitigable adverse impact on the availability of walruses and polar 
bears for taking for subsistence uses during the regulatory timeframe.
    While walruses and polar bears represent a small portion, in terms 
of the number of animals, of the total subsistence harvest for the 
communities of Utqiagvik, Nuiqsut, and Kaktovik, the harvest of these 
species is important to Alaska Natives. Prior to receipt of an LOA, 
Industry must provide evidence to us that community consultations have 
occurred or that an adequate POC has been presented to the subsistence 
communities. Industry will be required to contact subsistence 
communities that may be affected by its activities to discuss potential 
conflicts caused by location, timing, and methods of proposed 
operations. Industry must make reasonable efforts to ensure that 
activities do not interfere with subsistence hunting and that adverse 
effects on the availability of walruses and polar bear are minimized. 
Although multiple meetings for multiple projects from numerous 
operators have already taken place, no official concerns have been 
voiced by the Alaska Native communities regarding Industry activities 
limiting availability of walruses or polar bears for subsistence uses. 
However, should such a concern be voiced as Industry continues to reach 
out to the Alaska Native communities, development of POCs, which must 
identify measures to minimize any adverse effects, will be required. 
The POC will ensure that oil and gas 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 Industry will work with the affected Alaska Native communities and 
what actions will be taken to avoid interference with subsistence 
hunting of walruses and polar bears, as warranted.
    The Service has not received any reports and is aware of no 
information that indicates that walruses or polar bears are being or 
will be deflected from hunting areas or impacted in any way that 
diminishes their availability for subsistence use by the expected level 
of oil and gas activity. If there is evidence during the 5-year period 
of the regulations that oil and gas activities are affecting the 
availability of walruses or 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.

Monitoring and Reporting

    The purpose of monitoring requirements is to assess the effects of 
industrial activities on walruses and polar bears, ensure that the 
number of takes and the effects of taking are consistent with that 
anticipated in the ITR, and detect any unanticipated effects on the 
species or stocks. Monitoring plans document when and how bears and 
walruses are encountered, the number of bears and walruses, and their 
behavior during the encounter. This information allows the Service to 
measure encounter rates and trends of walrus and polar bear activity in 
the industrial areas (such as numbers and gender, activity, seasonal 
use) and to estimate numbers of animals potentially affected by 
Industry. Monitoring plans are site-specific, dependent on the 
proximity of the activity to important habitat areas, such as den 
sites, travel corridors, and food sources; however, Industry is 
required to report all sightings of walruses and polar bears. To the 
extent possible, monitors will record group size, age, sex, reaction, 
duration of interaction, and closest approach to Industry onshore. 
Activities within the specified geographic region may incorporate daily 
watch logs as well, which record 24-hour animal observations throughout 
the duration of the project. Polar bear monitors will be incorporated 
into the monitoring plan if bears are known to frequent the area or 
known polar bear dens are present in the area. At offshore Industry 
sites, systematic monitoring

[[Page 43043]]

protocols will be implemented to statistically monitor observation 
trends of walruses or polar bears in the nearshore areas where they 
usually occur.
    Monitoring activities will be summarized and reported in a formal 
report each year. The applicant must submit an annual monitoring and 
reporting plan at least 90 days prior to the initiation of a proposed 
activity, and the applicant must submit a final monitoring report to us 
no later than 90 days after the expiration of the LOA. We base each 
year's monitoring objective on the previous year's monitoring results.
    We require an approved plan for monitoring and reporting the 
effects of oil and gas Industry exploration, development, and 
production activities on polar bears and walruses prior to issuance of 
an LOA. Since production activities are continuous and long term, upon 
approval, LOAs and their required monitoring and reporting plans will 
be issued for the life of the activity or until the expiration of the 
regulations, whichever occurs first. Each year, prior to January 15, we 
will require that the operator submit development and production 
activity monitoring results of the previous year's activity. We require 
approval of the monitoring results for continued operation under the 
LOA.
    We find that this regulation will establish monitoring and 
reporting requirements to evaluate the potential impacts of planned 
activities and to ensure that the effects of the activities remain 
consistent with the rest of the findings.

Summary of and Response to Comments and Recommendations

Response to Comments

    The Service published a proposed rule in the Federal Register (FR) 
on June 1, 2021, with a 30-day period seeking comments on both the 
proposed ITR and the draft EA (86 FR 79082). The comment period closed 
on July 1, 2021. The Service received 30,271 comments. Comments were 
received from two Federal agencies, the Marine Mammal Commission, the 
State of Alaska, the North Slope Borough, various trade and 
environmental organizations, and interested members of the public.
    We reviewed all comments, which are part of the docket for this 
ITR, for substantive issues, new information, and recommendations 
regarding this ITR and EA. The Service used ``DiscoverText'' \1\ to 
aggregate the comments submitted by the public. The Service determined 
that of the comments received, 30,251, aggregated and submitted by the 
Center for Biological Diversity, consisted of comments all of which 
expressed opposition to the promulgation of the regulation. All 30,251 
of these comments either repeated, summarized, or provided edits to a 
standardized message. The Service notes that these modified form 
letters provided no new information or specific comments but rather 
brief to lengthy statements expressing the writer's general opposition 
to the ITR.
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    \1\ The use of DiscoverText does not convey or imply that the 
Service directly or indirectly endorses any product or service 
provided.
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    The comments are aggregated by subject matter, summarized and 
addressed below, and changes have been incorporated into the final rule 
and final EA as appropriate. A summary of the changes to this final ITR 
from the proposed ITR is found in the preamble section entitled, 
Summary of Changes from the Proposed Rule.

Response to Comments

MMPA Requirements
    Comment 1: One commenter suggested that the Service's definition of 
harassment does not consider the ``potential'' to disrupt biologically 
important behaviors, which results in an underestimation of the amount 
of take from activities.
    Response: The Service acknowledges that the definitions of 
harassment relevant to AOGA's specified activities are those found at 
16 U.S.C. 1362(18)(A)(i)-(ii). These definitions are cited in the ITR 
and were employed in the Service's analysis. The Service disagrees with 
the commenter's assertion that the Service misapplied these definitions 
in the ITR. The ITR language quoted by the comment is a partial quote 
that is not portrayed in appropriate context. The Service stands by its 
assumption that not all minor changes in behavior (i.e., 
``disturbances'') are of a type that can result in harassment, even 
Level B harassment, because they simply would not disrupt natural 
behavioral patterns. By way of a simple example, where a polar bear 
perceived noise from an industrial source located several miles away, 
the bear could potentially manifest a ``disturbance'' by briefly 
pausing travel and/or looking toward the noise source, but it would 
quickly resume what it was doing a moment prior, without any disruption 
to its pattern of natural behavior. That said, where the noise source 
is sufficiently loud or close to the polar bear such that the polar 
bear may flee, express stress-related behavior, abandon a hunt, find 
itself unable to rest for long periods, or react in one of the numerous 
other manners cited by the ITR as indicative of a disruption of natural 
behavioral patterns, the Service assumes that a take by Level B 
harassment occurs.
    Meanwhile, the Service disagrees with the commenter's apparent 
suggestion to use the most sensitive individual (an ``outlier'' in 
statistical terms) in the SBS population as the basis for all of its 
modeling assumptions. Doing so would ignore the best available 
scientific evidence about how the vast majority of polar bears react to 
industrial stimuli, effectively replace the implementing regulations' 
use of the terms ``likely'' and ``anticipated'' with the term 
``possible'' (See 50 CFR 18.27(d)), result in vast overestimations of 
take, and fail to reflect what the Service or any other objective party 
could reasonably anticipate occurring. When conducting complex acoustic 
modeling of potential marine mammal responses to industrial stimuli, 
one must necessarily make a series of reasonable assumptions (including 
development and application of acoustic thresholds) in order to 
evaluate and quantify the potential for harassment. The Service's 
general approach and assumptions here are analogous to those typically 
utilized by the National Marine Fisheries Service (NMFS) when assessing 
the potential for anthropogenic noise to harass marine mammals.
    While it is possible that some animals do in fact experience 
disruption of behavioral patterns upon exposure to intermittent sounds 
at received levels less than [the 160dB acoustic threshold used by 
NMFS], this is not in and of itself adequate justification for using a 
lower threshold. Implicit in the use of a step function for quantifying 
Level B harassment is the realistic assumption, due to behavioral 
context and other factors, that some animals exposed to received levels 
below the threshold will in fact experience harassment, while others 
exposed to levels above the threshold will not. The Service reiterates 
two key concepts underpinning NMFS's modeling approach and comment 
response--that modeling assumptions must be realistic as opposed to 
based on outliers, and that not all disturbances lead to disruption of 
behavioral patterns and Level B harassment.
    Comment 2: One commenter suggested that the Service acknowledges a 
marine mammal's movement away from an area as take by Level B 
harassment, but they do not account for this movement in their take 
estimates.

[[Page 43044]]

    Response: We disagree. As a nomadic species, any assumptions of an 
individual polar bear's intent to inhabit a specific location would be 
arbitrary. Included in our estimates of takes by level B harassment are 
instances when a polar bear changes course and moves in a different 
direction due to human interaction. However, the Service does not 
consider only ``increased vigilance'' to be a form of Level B 
harassment, because increased awareness of potential hazards in an 
animal's environment does not constitute a disruption of biologically 
significant behaviors as defined in the MMPA. Further, the Service does 
not classify a lower probability of denning near industrial 
infrastructure as a form of Level B harassment. We explain in the 
proposed rule that denning habitat adjacent to industrial activity has 
not been removed as a potential denning location. This is evidenced by 
our use of a probability distribution to determine potential offsets 
from active industrial sites when placing simulated dens, as opposed to 
a strict rule of simulating dens a fixed distance away from industry. 
We include the potential impact from new oil and gas infrastructure 
when simulating dens during our denning analysis as well.
    Comment 3: One commenter suggested that the Service should 
reevaluate their determinations and either deny the Request to issue an 
authorization or issue a revised proposed ITR after addressing public 
comments before promulgating the ITR.
    Response: The Service disagrees. The ITR includes a thorough and 
robust analysis based on detailed descriptions from the applicant of 
specified activities and the best available science. The Service has 
reasonably determined that the taking associated with AOGA's specified 
activities meets all applicable MMPA standards and will therefore issue 
the requested ITR, subject to appropriate conditions, pursuant to its 
statutory directive. There are no significant changes to AOGA's Request 
or the Service's assumptions, or analysis that would require publishing 
a revised proposed ITR.
    Comment 4: Commenters suggested that the Service is applying new 
and unreasonable interpretation of ``small numbers'' and should define 
their small numbers determination as well as explain why the Service 
anticipates an increase in harassment during this 5-year regulation 
period compared to the previous 5-year regulation period.
    Response: The Service's ``small numbers'' determination is 
consistent with applicable law, policy, and longstanding practice. 
There are several considerations relevant to the Service's ``small 
numbers'' standard, but the number of takes estimated in prior 
regulatory processes is not one of them. The SBS population estimate, 
calculated by USGS in 2020, is calculated using a number of annual 
metrics, including annual survival probabilities, annual number of 
dens, and annual denning success. The resulting value is an estimate of 
the number of individuals in the population in any given contemporary 
year. Appropriately, the Service has divided annual take estimates by 
the annual population estimate, to calculate a percentage of the 
population potentially taken for its small numbers determination.
    The Service has explained at length the quantitative methods that 
have been used to estimate the number of Level B harassment events 
projected in the proposed ITR.
    Comment 5: One commenter suggested that the Service combined the 
small numbers determination with the negligible impact determination, 
and these determinations should be addressed separately.
    Response: The Service rendered separate determinations for ``small 
numbers'' and ``negligible impact'' based on the distinct 
considerations relevant to each standard. It did not ``conflate'' these 
findings. This was explained in the proposed rule and remains true in 
the Final ITR.
    Comment 6: One commenter suggested that the Service's small number 
determination is inconsistent with the number of takes by Level B 
harassment anticipated for SBS polar bears and that polar bears 
repeatedly harassed should be considered in the Service's 
determination.
    Response: The potential that individual polar bears could 
experience multiple incidents of Level B harassment was acknowledged 
and accounted for in this analysis. The effects of each incident of 
Level B harassment (as opposed to more severe forms of take) are 
inherently limited and short term, and the Service does not anticipate 
that the effects of multiple Level B harassments of the same polar bear 
would aggregate or combine with each other in a manner that causes 
anything greater than Level B harassment. Per the MMPA, ``small 
numbers'' refers to the number of animals incidentally taken, not the 
number of incidental takes as the comment here suggests. That said, 
because the Service could not reliably calculate how many of the 
anticipated Level B harassments would accrue to the same animals, it 
conservatively assumed for the purposes of its ``small numbers'' 
determination that each of the anticipated takes would accrue to a 
different animal.
    Comment 7: Commenters suggested that the Service ignores the 
potential negligible impact implications for a skew within the model 
used to analyze denning impacts and the potential for take by Level A 
harassment.
    Response: The ITR does not authorize any Level A harassment or 
lethal take of polar bears (nor did AOGA request authorization for such 
take). The Service did employ a complex model to analyze the 
probability that harassing a denning or post-emergent bear could result 
in lethal take of her cubs. We provided all of the output data from the 
simulations as part of the proposed rule to be transparent and allow 
commenters to see for themselves where take comes from and why there is 
such a significant skew in the data on the number of estimated lethal 
take or serious take by Level A harassment. The reason for the skew is 
because the majority (i.e., 54%) of model iterations estimated 0 
serious takes by Level A harassment or lethal takes occurring annually. 
We disagree with the commenter that the skew is caused by a combination 
of the number of dens and the number of bears in dens that are 
disturbed. In reality, the skew is the result of the high number of 
iterations where 0 take is estimated. It is true that the tail of the 
distribution is a function of the number of dens disturbed and the 
number of cubs in those dens. We disagree that the Service is ignoring 
the potential for take by Level A harassment. We presented all of the 
output of the model to be as transparent as possible, and to fully 
assess the potential that estimated and authorized Level B harassment 
of a denning or post-emergent sow could result in abandonment of her 
cubs. We also disagree that the mean is the appropriate metric to 
consider when estimating the expected level of take associated with the 
proposed activities. Means are the appropriate measure of central 
tendency when data are normally distributed or some other symmetric 
distribution. In these cases, the mean and median are nearly the same. 
However, when the data are significantly skewed, as our results are, 
the median is a more appropriate informative measure of the central 
tendency in the data.
    Comment 8: Commenters suggested that the Service should consider 
the effects of potential take by Level A harassment and potential 
lethal take of polar bear cubs for the negligible impact.
    Response: The Service has conducted a thorough analysis using 
detailed

[[Page 43045]]

project descriptions from the applicant and quantitative estimates of 
take developed using the best available science. As is explained in the 
proposed rule, due to the low (<0.29 for non-serious Level A and 
<=0.462 for serious take by Level A harassment/lethal takes) 
probability of greater than or equal to 1 non-serious or serious injury 
Level A harassment/lethal take each year of the proposed ITR period, 
combined with the median of 0.0 for each, we do not estimate the 
proposed activities will result in non-serious or serious injury Level 
A harassment or lethal take of polar bears.
    The Service is not authorizing any lethal take (or any forms of 
take other than by Level B harassment). The Service fully considers the 
probability that the authorized take will adversely affect the species 
or stock through effects on annual rates of recruitment or survival. 50 
CFR 18.27(c).
    Comment 9: One commenter suggested that the Service used outdated 
polar bear survey data for the Service's small number and negligible 
impact determinations and the Service should use more recent data on 
the SBS polar bear stock in order to make the small numbers and 
negligible impact determinations.
    Response: The Service is obligated to render its MMPA 
determinations based on the best available scientific evidence. The 
most recent population estimate available for the SBS stock of polar 
bears is contained within a 2020 report from USGS, and this estimate 
was utilized in the Service's analysis.
    Comment 10: One commenter suggested that the Service should conduct 
further research on the availability of polar bears for subsistence 
uses.
    Response: The Service acknowledges that more studies on the current 
availability of polar bears for subsistence hunting on the Coastal 
Plain of Alaska could improve our analysis. However, as discussed in 
the proposed rule, and reaffirmed in this final rule, the Service has 
based our determinations on the best information currently available.
    Comment 11: One commenter suggested the Service should conduct 
further research on human-polar bear interactions during oil and gas 
activities in order to reduce polar bear take during these interactions 
and to better inform the Service's small numbers and negligible impact 
determinations.
    Response: The Service acknowledges that additional information to 
better understand human-polar bear interactions and how to avoid, 
reduce, and mitigate the number of bears taken as a result of conflicts 
with oil and gas activities would be beneficial. However, as discussed 
in the proposed rule, and reaffirmed in this final rule, the Service 
has based our determinations on the best information currently 
available.
    Comment 12: One commenter suggested that the Service should analyze 
the impacts of incidental takes during previous regulation periods in 
order to assess cumulative impacts of those previous takes on the SBS 
polar bear stock and the Service should use this information to inform 
the Service's small numbers and negligible impact determinations for 
the current regulation period.
    Response: The Service appreciates the concerns raised in this 
comment. As discussed in the proposed rule, and affirmed in this final 
rule, the Service requires holders of an LOA to report, as soon as 
possible, but within 48 hours, all LOA incidents during any Industry 
activity. The Service, in turn, monitors these reports to ensure the 
type of take, if any, are consistent with the terms of the LOA. The 
Service also monitors the cumulative takes reported by all LOA holders 
to ensure the total number of takes, authorized under an ITR, do not 
exceed those authorized/estimated. The Service used this information 
when it considered the environmental baseline and status of the species 
and when it evaluated the impacts of AOGA's specified activities.
    Comment 13: One commenter suggested that the Service should 
consider including take from other sources not related to oil and gas 
activities, such as subsistence take and unknown mortality events, as 
part of the Service's environmental baseline, which is used to estimate 
take and determine negligible impact.
    Response: The Service adequately considered the potential for all 
forms of take--including take for subsistence uses--as well as natural 
mortality when conducting its analysis and making its negligible impact 
finding.
    Comment 14: One commenter suggested that the Service should include 
climate change impacts as part of the Service's analysis to estimate 
take for the regulation period.
    Response: The Service presented a thorough discussion on the 
baseline conditions for the population, including the potential effects 
of climate change on polar bears, Pacific walruses, and prey species. 
The ITR authorizes only Level B harassment of small numbers of the 
population. Such take would result in only temporary behavioral changes 
even considering the current baseline stressors experienced by the 
population due to climate change. No Level A harassment or lethal take 
is estimated as a result of the proposed activities, and none is 
authorized by this ITR.
    Comment 15: Commenters suggested that the Service should base the 
Service's small numbers determination on the total estimated take 
number for the 5-year regulation period instead of the annual take 
estimates across the 5-year regulation period.
    Response: The SBS population estimate, calculated by USGS in 2020, 
is calculated using a number of annual metrics, including annual 
survival probabilities, annual number of dens, and annual denning 
success. The resulting value is an estimate of the number of 
individuals in the population in any given contemporary year. 
Appropriately, the Service has divided annual take estimates by the 
annual population estimate, to calculate a percentage of the population 
potentially taken for its small numbers determination. This approach 
best enables the Service to assess whether the number of animals taken 
is small relative to the species or stock. Consideration of annual 
estimates tracks with the use of ``each'' in 16 U.S.C. 1371(a)(5)(A)(i) 
and the use of annual LOAs to authorize the incidental take. Comparing 
the aggregate number of takes over 5 years with a population estimate 
specific to 1 year, as commenter suggest doing, is a less suitable 
comparison. In previous Beaufort Sea ITRs, the Service has always 
relied on annual estimates based on encounters during previous years 
and the proportion of those individuals that experienced take by Level 
B harassment. This ITR differs in that it uses the best available 
science and additional details associated with each project to more 
accurately estimate encounters and takes anticipated by the specified 
activities. The Service's ``small numbers'' determination here is 
consistent with applicable law, policy, and longstanding practice.
    Comment 16: One commenter suggested that the Service should clarify 
that the scope of the proposed rule is the issuance of the proposed ITR 
and that the proposed ITR does not authorize proposed activities.
    Response: The Service agrees that the proposed action analyzed in 
the EA is the issuance of an ITR and authorization of incidental take 
associated with AOGA's specified activities, and not approval of the 
oil and gas activities themselves. The Service also agrees that the ITR 
does not authorize intentional take and agrees that oil spills are not 
a consequence of ITR or the Proposed Action analyzed in the Service's 
EA.

[[Page 43046]]

    Comment 17: One commenter suggested that the Service should clarify 
the activities that exceed the scope of the Service's analysis and 
determinations and will not be issued an LOA.
    Response: The Service has provided language to this final rule that 
clarifies the activities addressed in this ITR and the incidental take 
that may be authorized via LOAs.
    Comment 18: One commenter suggested that the Service should broaden 
the list of entities associated with the Request that are able to apply 
for LOAs.
    Response: We agree. This final rule has been revised to clarify 
what entities may request LOAs under these regulations.
    Comment 19: One commenter suggested that the Service's larger take 
estimate for polar bears compared to the previous ITR's polar bear take 
estimate and the reduced polar bear population size is inconsistent 
with the Service's negligible impact determination.
    Response: ``Negligible impact'' determinations are based on several 
considerations, but the number of takes estimated in prior regulatory 
processes is not one of them. The Service rendered its negligible 
impact determination here based on the effects of the taking from the 
activities specified in the pending Request.
    Comment 20: Commenters suggested that the Service did not ensure 
that the proposed activities will have the least adverse impact 
practicable.
    Response: We disagree. As explained in the proposed rule, and 
affirmed in this final rule, the Service conducted a robust analysis, 
on the proposed activities and, based on that analysis, prescribed the 
means that will effect the least practicable adverse impact on Pacific 
walrus and SBS polar bears, their habitat, and their availability for 
taking for subsistence use by Alaska Natives.
    Comment 21: One commenter suggested that the Service arbitrarily 
and capriciously underestimated the likelihood of take other than that 
by Level B harassment to occur during the regulation period.
    Response: We disagree. As explained in the proposed rule, and 
affirmed in this final rule, the Service conducted a robust analysis of 
the potential effects of AOGA's specified activities. Further, we 
sought public comment on our analysis, affording interested parties the 
opportunity to provide new information on our analysis and considered 
all information provided to the Service prior to finalizing these 
regulations. The Service's actions are therefore lawful and, in no way, 
arbitrary and capricious.
    Comment 22: One commenter suggested that the Service's analysis of 
activity impacts was too specific, which exceeds the scope of the ITR, 
and this approach inappropriately merges the LOA process, which 
requests authorization for incidental take during specific activities, 
into the ITR analysis.
    Response: The Service acknowledges that it requested and analyzed 
more detailed information concerning the requestor's specified 
activities than is typically provided, but maintains that doing so was 
necessary to rigorously analyze these activities and confirm that 
applicable MMPA standards are met. The Service's enhanced analytical 
approach utilized newly-available information and predictive modeling 
techniques that better account for potential effects to polar bears 
that may occur but remain beyond observers' capacity to perceive. A 
comparatively greater degree of specificity concerning the requestors' 
specified activities was required to (1) ensure that the Service 
accounted for both observable and unobservable take, and (2) reduce 
uncertainties about the level, location, and duration of the specified 
activities and thus limit the use of overly-conservative assumptions 
that result in inappropriate overestimation of take. The Service 
conducted this more in-depth analysis at the ITR stage so the results 
could inform its MMPA-required determinations (e.g., small numbers, 
negligible impact, no unmitigable adverse impact on availability for 
subsistence uses, least practicable adverse impact).
    Comment 23: One commenter suggested that the Service should remove 
language that potentially limits which U.S. citizens can apply for LOAs 
under the ITR.
    Response: We disagree. Section 101(5)(A)(i) of the MMPA and the 
Service's implementing regulations afford requestors with broad 
discretion in delineating scope of the activities specified in their 
request. U.S. citizens intending to engage in activities not 
encompassed by a particular request can submit their own request, which 
the Service will review accordingly.
    The Service acknowledges that under past ITRs we have issued LOAs 
to entities not specifically named in the request for regulations. This 
practice was permissible under the applicable ITR.
    Comment 24: One commenter suggested that the Service did not 
provide oil and gas operators not specified in the ITR with a 
sufficiently advance notice to apply for a separate incidental take 
authorization without a gap in coverage.
    Response: We disagree with the notion that the Service is obligated 
to inform operators that they will not be covered by an ITR they did 
not request. The Service does acknowledge that under past ITRs we have 
issued LOAs to entities not specifically named in the request for 
regulations. However, the narrower scope of the current request and the 
Service's ensuing analysis does not allow for that practice. We note 
that the MMPA and our regulations allow other qualifying companies to 
request ITRs or IHAs for their activities.
    Comment 25: One commenter suggested that the Service should 
reconsider its small numbers determination based on the estimated 
number of takes by Level B harassment.
    Response: As was stated in the proposed rule, take of 92 animals is 
10.14 percent of the best available estimate of the current stock size 
of 907 animals in the Southern Beaufort Sea stock (Bromaghin et al. 
2015, Atwood et al. 2020) ((92 / 907) x 100 [ap] 10.14), and represents 
a ``small number'' of polar bears of that stock.
    Comment 26: One commenter suggested that the Service makes 
inadequate assumptions and underestimated the number of polar bears 
that may be taken by Level A and Level B harassment during activities 
and that the Service should reconsider its small numbers and negligible 
impact determinations.
    Response: The Service's assumptions were reasonable and consistent 
with the MMPA.
    Comment 27: One commenter suggested that the percentage (40%) of 
SBS polar bear maternal land dens estimated to be exposed to potential 
take by Level B harassment was inconsistent with the Service's small 
numbers determination.
    Response: As is described under Evaluation of Effects of Specified 
Activities on Pacific Walruses, Polar Bears, and Prey Species, the 
Service has estimated less than 3.2 Level B harassment events to 
denning bears each year as a result of the proposed activities. This 
does not represent ``40% of all the maternal land dens'' for the SBS 
stock.
    Comment 28: One commenter suggested that the Service should account 
for harassment of undetected polar bear maternal dens in their take 
estimates in order to avoid underestimating the number of takes for the 
regulation period and affecting the Service's small numbers 
determination.
    Response: The Service's analysis properly accounts for the 
anticipated

[[Page 43047]]

number and potential locations of maternal dens and applies reasonable 
assumptions concerning their rate of detection. The Service disagrees 
with the notion that it grossly underestimated the number of polar 
bears that will be taken under the ITR.
    Comment 29: A commenter suggested that the Service should consider 
whether the estimated number of takes exceeds the potential biological 
removal for the SBS polar bear stock in order to make its negligible 
impact determination and the Service should also consider other sources 
of anthropogenic take as part of the Service's baseline to evaluate 
negligible impacts on the SBS polar bear stock from oil and gas 
activities.
    Response: The only take anticipated and authorized by the Service 
from AOGA's specified activities is Level B harassment. The Service 
does not anticipate or authorize any taking that will impair the 
survival of any polar bears. The Service did not identify any mechanism 
through which impacts associated with authorized Level B harassment 
(which are inherently short-term and limited) could interact with 
impacts from other sources of anthropogenic take such that serious 
injury or death could result (nor does the commenter establish such 
possibility).
    Comment 30: Commenters suggested that the Service should account 
for take by Level A harassment for the duration of the 5-year 
regulation period in order to determine whether there would be more 
than a negligible impact.
    Response: The Service evaluated the probability of take by Level A 
harassment for each of the 5 years covered by this ITR. In determining 
whether the authorized take will have a negligible impact on the SBS 
stock of polar bears, the Service applies the definition in its 
implementing regulations, which define a negligible impact as an impact 
resulting from the specific activities that cannot be reasonably 
expected to, and is not reasonably likely to, adversely affect the 
stock through effects on annual rates of recruitment or survival. 50 
CFR 18.27(c). Not all Level A harassment events affect annual rates of 
recruitment or survival. Hence the distinction between serious and non-
serious take by Level A harassment. The Service estimates a 46% 
probability of take that is pertinent to the negligible impact standard 
(i.e., take that results in serious injury of mortality). The 
probability of harassing denning bears such that lethal take of one or 
more cubs occurs is appropriately assessed on an annual basis in order 
to give effect to the term ``annual'' as it appears in these 
regulations. While the Service is always concerned with any potential 
for mortality to cubs, it has worked with the applicant to integrate 
numerous mitigation measures to further reduce the potential for such 
events, and it does not reasonably expect such events to affect annual 
rates of recruitment or survival. The Service further notes that its 
approach to applying the ``negligible impact'' standard here is 
consistent with the 1-year duration of any LOAs (which actually 
authorize the incidental take pursuant to the framework established in 
the ITR) as well as the manner in which the Service applies the 
``negligible impact'' standard in the context of IHAs, which would 
remain available as an alternative approach for requesting and 
authorizing take were the Service unable to make the requisite 
determination for this ITR.
    Comment 31: One commenter suggested that the Service should clarify 
the explanations for their small numbers and negligible impact 
determinations and the consistency of these determinations with their 
regulations.
    Response: The Service reasonably applied the relevant statutory and 
regulatory standards and not impermissibly relied on any limitations 
not included in the regulations. Further clarification of these issues 
is provided in various comment responses.
    Comment 32: One commenter suggested that the Service should clarify 
whether take during activities under the previous ITR (2016-2021) was 
included in the Service's baseline to evaluate Industry impacts on 
marine mammals.
    Response: Consistent with the MMPA and its implementing 
regulations, the Service makes its ``negligible impact'' on a request-
by-request basis. In other words, it does not aggregate take associated 
with the current request with take associated with prior 
authorizations. That said, the Service's ITR and NEPA analyses do 
consider the current status of the relevant stock or species (here, SBS 
polar bears), to include any residual impacts caused by prior taking, 
when rendering its MMPA determinations and NEPA conclusions.
    Comment 33: One commenter suggested that the Service should clarify 
why they do not anticipate take by Level A harassment to occur during 
Industry activities given the 0.46 probability of take by Level A 
harassment of a polar bear cub and how the potential for take by Level 
A harassment will impact the SBS polar bear stock.
    Response: The Service applied the relevant statutory and regulatory 
terms in a reasonable manner and determined for the purpose of applying 
the ``negligible impact'' standard that the authorized take ``cannot be 
reasonably expected to, and is not reasonably likely to'' adversely 
affect the SBS stock of polar bears through effects on annual rates of 
recruitment or survival. Considering annual probability rates is the 
most appropriate way to address the applicable regulatory standard, 
which is expressed in annual terms. And the fact the zero Level A 
harassment or lethal takes is the most likely result in any given year 
precludes a reasonable expectation that such take will, in fact, occur. 
Level A harassment (either non-serious or serious) to bears on the 
surface is extremely rare within the ITR region. The Service further 
notes that the mitigative effect of certain measures described in 
AOGA's request--i.e., avoidance of steep slopes and use of trained 
observers to clear potential denning areas prior to road construction--
could not be reliably quantified and thus integrated into the Service's 
modelling analysis, but may further reduce the probability of den 
disturbance.
    Comment 34: One commenter suggested that the Service should clarify 
how the probability of take of polar bears by Level A harassment during 
industry activities will impact the SBS polar bear stock from reaching 
or maintaining its optimum sustainable population and whether this 
impact is consistent with the Service's negligible impact 
determination.
    Response: The Service has conducted a thorough analysis using 
detailed project descriptions from the applicant and quantitative 
estimates of take developed using the best available science. As is 
explained in the proposed rule, due to the low (<0.29 for non-serious 
Level A and <=0.462 for serious take by Level A harassment/lethal 
takes) probability of greater than or equal to 1 non-serious or serious 
injury take by Level A harassment/lethal take each year of the ITR 
period, combined with the median of 0.0 for each, we do not estimate 
the proposed activities will result in non-serious or serious injury 
take by Level A harassment or lethal take of polar bears.
    Comment 35: One commenter suggested that the Service should 
reevaluate its determinations and either deny the Request to issue an 
authorization or issue a revised proposed ITR after addressing public 
comments before promulgating the ITR.
    Response: The Service disagrees. The ITR includes a thorough and 
robust analysis based on detailed descriptions from the applicant of 
specified activities and the best available science. The Service has 
found no basis to deny the

[[Page 43048]]

Request and statutorily ``shall'' authorize incidental take of marine 
mammals for specified activities where the requisite MMPA 
determinations are made. There are no significant changes to AOGA's 
Request, the Service's assumptions, or analysis that would require 
publishing a revised proposed ITR.
    Comment 36: Commenters suggested that in the EA the Service should 
account for climate change impacts in order to assess impacts on polar 
bears and walruses potentially affected by Industry activities, and one 
commenter suggested the Service clarify impacts from other Industry 
activities and associated risks and cumulative impacts beyond the 5-
year regulation period.
    Response: The EA appropriately focuses on the reasonably 
foreseeable impacts of the Proposed Action, i.e., issuing the ITR. The 
ITR authorizes the Level B harassment associated with certain oil and 
gas activities, and does not authorize the oil and gas activities 
themselves. That said, the EA analyzes reasonably foreseeable impacts 
in the context of an environmental baseline that includes climate 
change-related impacts to polar bears and walruses. Climate change-
related effects were also considered in the EA's analysis of cumulative 
impacts. As is explained in the ITR and the EA, the effects of the 
authorized level B harassment are inherently limited and temporary and 
are not expected to persist beyond the 5-year period addressed in the 
ITR.
    Comment 37: One commenter suggested that the Service should 
consider additional factors, such as population trends, increased land 
use, and increased potential for human-polar bear conflicts, as part of 
the baseline to determine negligible impacts on polar bears.
    Response: We agree with the commenter that changing sea ice 
conditions have affected and will continue to affect polar bears in the 
SBS subpopulation in various ways. We disagree, however, that we failed 
to consider these factors or that all of them are relevant to 
estimating potential impacts from AOGA's Request. For example, we 
account for changes in the subpopulation's demographics by using the 
best available science (e.g., Atwood et al. 2020) to inform the denning 
impact analysis and for setting the potential biological removal level 
(PBR). We also account for changes in the spatial distribution of bears 
(i.e., more bears on land) in both our denning analysis (i.e., Olson et 
al. 2017) and surface analysis (i.e., Wilson et al. 2017). Many of the 
other factors listed do not have published or verified relationships 
with industrial activity, so it's unclear how exactly to incorporate 
those factors into estimating the effects of industrial activities on 
polar bear disturbance levels. Even so, this does not mean that the 
effects are not implicitly accounted for as most of the studies we rely 
on to parameterize our analysis are based on data collected during the 
period when population-level effects of sea ice loss have been observed 
for the SBS (i.e., 2000 onwards). For example, our case study analysis 
contains a significant number of observations from this period and 
should thus reflect any changes on how bears respond or are affected by 
disturbance. Similarly, for our analysis of surface-level interactions, 
observations come from our LOA database in the period 2014-2018, a 
period that reflects the potential for increases in encounters between 
bears and humans and modified polar bear behavior as a result of 
potential nutritional stress.
    Comment 38: One commenter suggested that the Service used an 
outdated and highly criticized population estimate for SBS polar bears 
and that the levels of take determined for this population likely 
reflect an overestimated percentage of the population being impacted by 
Industry activities.
    Response: We do not rely on the results of Bromaghin et al. (2015) 
for analysis but rather on Atwood et al. (2020). Bromaghin et al. 
(2015) does not apply just to the U.S. portion of the SBS, and while 
Atwood et al. (2020) does, it provides evidence that the abundance in 
that area is similar to that found in Bromaghin et al. (2015), thus 
providing support for stability in the overall sub-population estimate 
and, therefore, being no different from that published in Bromaghin et 
al. Without additional details on how those estimates are biased low, 
we do not address them, and instead rely on the best available 
scientific evidence. Currently, Bromaghin et al. (2015) and Atwood et 
al. (2020) represent the best available science on the status of the 
SBS subpopulation.
    The Service does not calculate ``maximum allowable'' levels of 
lethal take or take by Level A or Level B harassment. Instead, the 
Service bases its determinations on the effects of the estimated 
incidental take from the activities specified in the Request. Here, no 
lethal take or Level A harassment is anticipated to occur or 
authorized, and the Level B harassment that is anticipated and 
authorized meets applicable MMPA standards. The Service is unaware of 
any information that supports a low bias in the Atwood et al. (2020) 
estimates.
    Comment 39: Commenters suggested that the Service's cautious 
approach to determine take estimations resulted in overestimating take 
of polar bears and this overestimation may impact the availability of 
polar bears for subsistence harvest, which may lead to conflicts 
between Industry entities and subsistence communities.
    Response: The Service disagrees with the commenter's suggestion 
that the ITR inappropriately overestimated take, may lead to conflict 
between industry and subsistence communities, and may impact the 
availability of polar bears for subsistence harvest.
    Comment 40: One commenter suggested that the Service should explain 
how their quantitative evaluation of Industry impacts on polar bears is 
valid and address the inconsistency with their statement in NPR-A that 
states that quantitative evaluation of the potential effects of 
disturbance of polar bears is constrained by various factors.
    Response: The Service has worked with AOGA to gather the necessary 
information on the nature, location, and timing of activities for the 
quantitative analyses presented in the ITR. The Service's polar bear 
sighting database was incorporated into the analyses to provide 
information on abundance, distribution, and response of polar bears 
within the ITR area. While no projection of effects of future 
activities is perfect, the Service utilized best available scientific 
evidence, to include robust and peer-reviewed predictive modeling 
techniques, to perform a comprehensive analysis of estimated impacts, 
and to render reasoned determinations.
    Comment 41: Commenters suggested that the Service overestimated the 
number of incidental polar bear takes and that actual instances of 
polar bear take will be much less over the 5-year regulation period, 
and requested the Service clarify whether this overestimation of take 
will affect additional Industry entities seeking take authorizations.
    Response: We disagree that the methodology we use leads to an 
inappropriate overestimate of take. The Service has used best available 
science to generate quantitative take estimates that represent the 
total potential take that may occur as a result of the activities 
included in the applicant's Request. Under the existing and previous 
ITRs, AOGA was required to survey for dens only along ice road and 
tundra travel routes. Therefore, the majority of their project area was 
not surveyed for dens, and, consequently,

[[Page 43049]]

their status was not monitored. While additional dens have been 
observed upon emergence, it is clear that without dedicated observers 
across the entire project area, it would be impossible to observe the 
vast majority of denning bears and their response to potential 
disturbance. This is especially true given the limited light conditions 
present during the majority of the denning period. Additionally, a 
large portion of the estimated take would not be observable to 
Industry. Rode et al. (2018) showed that when bears emerge early from 
dens, there is a survival consequence to cubs when subsequent 
observations are made ~100 days post emergence. Thus, the ultimate 
effects of the disturbance would likely not manifest themselves until 
after the bears had left the area and are no longer observable by 
industry. With respect to the Larson et al. (2020) study, we did 
consider it in our analysis, but the study did not consider the well-
documented differences in responses across different denning periods, 
which we accounted for, and it was unclear what periods their 
observations were from. Thus, it was unclear what level of bias was 
present in their response data.
    Analyzing the extent--if any--to which this ITR may affect the 
activities not described in AOGA's Request is beyond the scope of this 
analysis.
    Comment 42: One commenter suggested that the Service should 
reconsider including intentional takes as part of their data to 
estimate the number of incidental takes because their inclusion will 
lead to an overestimation of the number of takes by Level B harassment 
anticipated for the regulations and ITRs may authorize only incidental, 
but not intentional, take by harassment.
    Response: The Service does not authorize intentional take under 
this ITR. But as the quoted language indicates, the Service did 
consider data concerning expected intentional take (i.e., hazing) rates 
in its analysis of incidental take. It did so because intentional take 
events are usually preceded by events that qualify as Level B 
harassment, and it is necessary to account for such instances of 
incidental take in the larger estimate of incidental take rates. In 
other words, the Service used intentional take rates as a proxy for the 
incidental take that generally proceeds intentional take (i.e., hazing) 
events. The Service recognizes that not all instances of intentional 
take are preceded by incidental take, but does not have data sufficient 
to support application of a reliable correction factor, and therefore 
made this conservative assumption to help ensure that its analysis 
accounts for all incidental take.
    Comment 43: One commenter suggested that the Service overestimated 
the probability of take of polar bears by Level A harassment during 
Industry activities because the Service does not account for 
habituation of polar bears to Industry activities, adaptive mitigation 
measures, and the variability of received stimuli within a polar bear 
den.
    Response: We disagree with the suggestion that bears choosing to 
den near industrial infrastructure and activities can be assumed to be 
indifferent to human activity. In fact, in our review of case studies, 
we found numerous instances of bears denning adjacent to industrial 
activities that exhibited disturbance indicative of harassment. We 
agree that stimuli received by bears in dens is highly variable, as 
shown in Owen et al. (2020). However, just because a bear detects a 
signal (as was the scope of Owen et al. 2020) doesn't indicate whether 
it is likely to respond to that stimuli. Thus, it is not possible to 
use the data from Owen et al. (2020) to estimate more refined distances 
at which bears react to different types of activities while denning. 
Even Owen et al. (2020) acknowledges that a 1-mile no disturbance 
buffer is still supported by their research. There is currently no 
study that establishes a curve establishing a relationship between the 
distance to a potential source of disturbance and the probability that 
it leads to disturbance. Therefore, we used the best available 
information to develop response rates of bears within 1-mile of 
potential exposures. Those response rates incorporate bears that never 
perceived the activity and therefore never responded, those that 
perceived the activity but never responded, and those that perceived 
the activity and responded. We then applied these responses to dens 
within 1 mile of an activity to determine potential disturbances.
    Comment 44: One commenter suggested that the Service should clarify 
how the estimated number of takes will be evaluated to determine LOA 
issuance under these regulations.
    Response: The Service will issue LOAs in the manner described in 
its implementing regulations at 50 CFR 18.27(f). The Service does not 
intend to conduct predictive modeling of the potential effects of the 
activities described in each request for an LOA. Nor does the Service 
intend to prosecute recipients of LOAs for unauthorized take that is 
suggested by modeling but not supported by observations or any other 
evidence.
    Comment 45: One commenter suggested that the Service should 
consider that the SBS polar bear abundance estimate upon which the 
Service based its small numbers and negligible impact determinations is 
biased low.
    Response: Bromaghin et al. (2015) does not apply just to the U.S. 
portion of the SBS and while Atwood et al. (2020) does, it provides 
evidence that the abundance in that area is similar to that found in 
Bromaghin et al. (2015), thus providing support for stability in the 
overall sub-population estimate and, therefore, being no different from 
that published in Bromaghin et al. Currently Bromaghin et al. (2015) 
and Atwood et al. (2020) represent the best available science on the 
status of the SBS subpopulation.
    Comment 46: One commenter suggested that the Service should clarify 
why they used the cited SBS polar bear population estimate for their EA 
and ITR and discuss whether more recent polar bear population abundance 
data exist.
    Response: The Service used the most current reliable population 
estimates of SBS polar bears in both its ITR and NEPA analyses. This 
was not Bromaghin et al. (2015) but rather Atwood et al. (2020). In 
their assessment, Atwood et al. (2020) did not find any significant 
differences in the size of the subpopulation between the two studies. 
The Atwood et al. (2020) study updated Bromaghin et al. (2015) but 
included additional years of data (through 2016) to provide a 
population estimate for the year 2015. Based on its ongoing monitoring 
of studies, observation reports, and related information, the Service 
believes these estimates continue to reflect a reliable estimate of the 
current population. In other words, the Service is not aware of any 
reliable information suggesting that the SBS population of polar bears 
has significantly declined over the last 6 years such that the 2015 
estimate is unreliable, nor has such information been submitted through 
the public comment process. The population estimate published in Atwood 
et al. (2020) is currently the best available information for the 
status of the SBS subpopulation. The Service disagrees with the 
commenter's unsupported assertion that there is a ``dearth'' of 
abundance data and a ``great deal of uncertainty in estimating 
population numbers.''
    Comment 47: One commenter suggested that the Service should address 
how polar bears are impacted by reduced access to their prey as a 
result of Industry activities and how this

[[Page 43050]]

factor was evaluated during take estimations.
    Response: The availability of prey was considered in the 
environmental baseline that informed the Service's analysis of 
potential effects of AOGA's specified activities and issuing the ITR. 
The Service does not foresee Level B harassment appreciably reducing 
polar bears' access to prey.
    Comment 48: One commenter suggested that the Service should clarify 
how serious take by Level A harassment and lethal take were determined 
in their take estimates.
    Response: While the probabilities of serious take by Level A 
harassment and Lethal takes were separated in Table 7, when summarizing 
model results in Table 8 these values were reported as a combined 
result. All necessary MMPA determinations were made using take 
estimates that combined serious take by Level A harassment and lethal 
take into the same general category.
    Comment 49: One commenter suggested that the Service should clarify 
the explanation for take by Level A harassment and lethal take 
probabilities.
    Response: As is stated in the ITR, the Service does not estimate 
the proposed activities will result in non-serious or serious injury 
take by Level A harassment or lethal take due to the low (<0.29 for 
non-serious take by Level A harassment and <=0.462 for serious take by 
Level A harassment/lethal takes) probability of greater than or equal 
to 1 non-serious or serious injury Level A harassment/lethal take each 
year of the ITR period, and a median of 0.0 for each.
    Comment 50: Paragraph 1 under the heading ``Level A Harassment'' 
states: Level A harassment to bears on the surface is extremely rare 
within the ITR region. From 2012 through 2018, one instance of Level A 
harassment occurred within the ITR region associated with defense of 
human life while engaged in non-Industry activity. This statement and 
its context are unclear, and we suggest clarifying in the final rule.
    Response: The referenced instance of Level A harassment represented 
an intentional take. This ITR process authorizes only incidental Level 
B harassment. We do not find that further clarification is warranted.
Analysis
    Comment 51: One commenter suggested that the Service should 
systematically collect data on polar bear dens rather than using 
opportunistic data to assess impacts.
    Response: Consistent with is regulations implementing the MMPA, the 
Service reviewed AOGA's Request using the ``best available scientific 
evidence.'' See 50 CFR 18.27(d)(3). The Service finds that the 
monitoring and reporting requirements specified in the ITR are 
sufficient. The Service will continue to evaluate opportunities for 
enhanced data collection but the extent to which the Service itself 
should engage in more systematic data collection is beyond the scope of 
this analysis.
    Comment 52: One commenter suggested that the Service should 
reevaluate the assumption to estimate take by Level A harassment for 
denning polar bears.
    Response: As was explained in the proposed ITR, the Service 
employed a set of reasonable assumptions derived from the best 
available scientific evidence to analyze what would happen if denning 
bears were disturbed by AOGA's specified activities.
    Comment 53: One commenter suggested that the Service should account 
for the increased risk of predation on polar bear cubs after den 
emergence as part of the Service's impact assessment for polar bears.
    Response: We disagree. We know of no instance or circumstance where 
a cub, recently leaving the den regardless of circumstances, would be 
able to successfully resist a predation attack. The only likely 
predators of young cubs in this environment at this time are other 
polar bears, wolves, or other large carnivores. Cubs at this age rely 
on their mothers for protection from predation.
    Comment 54: One commenter suggested that the Service should account 
for the potential lethal take of a polar bear as a result of a defense 
of human life during a human-polar bear encounter in the Service's 
negligible impact determination.
    Response: Under Section 101(a)(5)(A) of the MMPA, negligible impact 
determinations consider the effect of the specified activities and the 
incidental take to be authorized, and not the effects of intentional 
take described by the commenter. Defense of human life takes are 
authorized under a separate provision of the Act.
    Comment 55: One commenter suggested that the Service should 
reevaluate Industry impacts on denning polar bears.
    Response: The Service has conducted a thorough and robust analysis 
based on detailed descriptions from the applicant of activities 
occurring within the specified geographical region and the best 
available science. All activities within the ITR region that have the 
potential to impact denning polar bears have been included in this 
analysis.
    Comment 56: One commenter suggested that the Service should 
consider that estimating the number of polar bear dens for this ITR 
using historic observations may lead to underestimation due to the 
increased land use reported for the SBS polar bear stock.
    Response: The analysis does take into account the potential for >52 
dens to occur in the region. As stated in the text of the document 
detailing the den simulations (pp. 86 FR 29407-29408, June 1, 2021), we 
use statistical distributions for each region in the ITR (i.e., NPR-A, 
Colville to Canning, the 1002 area) to simulate a number of dens in 
each region during each iteration of the model. Based on how these 
distributions were parameterized, it is possible to have up to ~102 
dens simulated during any given iteration of the model. That is the sum 
of the upper 95% CI for each of the three regions where dens were 
simulated. Additionally, the data used in the den simulation portion of 
the model uses the best available information derived from the most up-
to-date den catalogue published by Durner et al. (2020). Olson et al. 
(2017) shows that in the period 2007-2013 55% of dens occurred on land, 
and this did not differ from the period of 1996-2006 (i.e., 54.5%). So, 
our results are consistent with these studies, based on the most recent 
data, and reflective of what we expect to occur during the five-year 
period of this ITR.
    Comment 57: One commenter suggested that the Service should 
consider the energetic costs of denning female polar bears relocating 
to alternative den sites and the associated impacts of these energetic 
costs on the survival for both mother polar bears and their cubs.
    Response: While we agree with the commenter that these types of 
relationships are conceivable, we are unaware of any research to 
support or document these claims. Further, these statements are just 
conjectures, and it's equally feasible that females have sufficient 
energetic reserves to find a new den site given that they already spend 
energy scouting for ideal den sites. We are therefore required to use 
the currently best-available information, which indicates minimal 
impacts to denning females if forced to find a new den site after being 
disturbed.
    Comment 58: One commenter suggested that the Service should 
consider whether the number of cubs affected by premature den departure 
is underestimated.
    Response: We disagree with the notion that we have underestimated

[[Page 43051]]

such impacts. We use the best available science to address this 
question. While we agree that there are likely local factors at a den 
site that could play a role in triggering when bears decide to depart 
the den site, those relationships have not been established, nor would 
there be any way to project those conditions to all future denning 
bears. We use real-world data on den emergence dates and time spent at 
the den site post-emergence but prior to permanently departing the 
area. These observations already contain natural variation in the 
timing of these events, possibly based on the local conditions or the 
specific attributes of denning females (e.g., nutritional condition). 
Thus, drawing from these distributions should allow for the level of 
natural variation to be accounted for in the analysis. While it's true 
a larger sample size would always be better, polar bears are difficult 
to study and we must therefore use what we have available. It is also 
worth mentioning that the sample sizes are not so small as to be 
unreliable. In fact they were deemed sufficient for inclusion into 
multiple peer-reviewed studies (e.g., Rode et al. 2014, Smith et al. 
2007).
    Comment 59: One commenter suggested that the Service should 
consider the potential impacts of take by Level A harassment that may 
result from a mother abandoning her cubs in response to disturbance.
    Response: The dataset that was used to analyze potential take from 
surface interactions encompassed all recorded human-polar bear 
interactions throughout the year, including the months when sows are 
moving toward the sea ice with cubs of the year. There are no recorded 
interactions in the 2014-2018 dataset between Industry and these bears 
that resulted in Level A harassment. The Service has also accounted for 
these potential interactions when establishing mitigation measures. 
Under the mitigation measures established in the proposed rule, 
Industry must survey for maternal polar bear dens, create exclusion 
zones around known dens, and report all polar bear interactions 
(including those with sows and cubs) to the Service within 48 hours of 
the event.
    Comment 60: One commenter suggested that the Service should 
consider the most recent evidence of cub survival and recruitment in 
the SBS polar bear population as part of their baseline to assess 
impacts to SBS polar bears.
    Response: We agree with the commenter that over the past ~20 years, 
cub-of-the-year survival in the SBS has been low relative to other 
subpopulations and is the primary driver of concomitant decreases in 
abundance. Survival was especially low in the period 2004-2008 (mean = 
~0.24), a period of marked population decline, but was relatively 
higher in the period 2009-2014 (mean = 0.50), the last year for which 
estimates are available (Atwood et al. 2020).
    Comment 61: One commenter suggested that the Service should clarify 
the explanation for distinguishing lethal take of polar bear cubs if 
cubs are abandoned before 60 days of age and serious take by Level A 
harassment of cubs if cubs are abandoned after 60 of age.
    Response: We disagree with the commenter that our different 
treatment of cubs emerging early during the early vs. late denning 
periods is inappropriate. We used 60 days based on published literature 
indicating that cubs have developed the basic functions to survive 
outside of the den by the time they reach ~2 months (60 days) of age. 
Prior to 60 days, the literature indicates that survival of cubs 
outside of the den is not possible. Serious Level A harassment is 
harassment that is likely to result in mortality. Based on the results 
of Rode et al. (2018), we know that early emergence from the den can 
lead to survival consequences for cubs. However, it is clear from the 
results of Rode et al. (2018) that not all cubs die as a result of 
early emergence (assuming they are >60 days old), thus, there is a 
different outcome to cubs emerging early during the early denning vs. 
the late denning periods. Hence, we treated early emergence during the 
late denning period as a serious Level A harassment because of the 
potential for a lethal outcome and lethal take for early emergence 
during the early denning period because of nearly 100% probability of 
cubs dying then.
    Comment 62: One commenter suggested that the Service should use 
systematically collected survey data that has been peer-reviewed in 
order to evaluate disturbance impacts to denning polar bears during 
Industry activities rather than use opportunistic observations of polar 
bear disturbance during Industry activities.
    Response: The case studies include published literature and reports 
of observations made by Industry and research and provided to USFWS. 
The published literature includes peer-reviewed literature, including 
literature by Amstrup (1993), which states that ``10 of 12 polar bears 
tolerated exposure to exceptional levels of activity'' and ``most bears 
in this study showed substantial tolerance to activity.'' They also 
state ``. . . live capture and marking were probably more disruptive to 
bears than other possible perturbations. Yet recruitment of cubs 
through the time of emergence from the den and sizes of cubs were not 
affected.'' In our analysis, we utilized the best available 
information, which included internal reports and observations, as well 
as peer-reviewed literature (e.g., Amstrup 1993). Thus, we used past 
reports to inform our findings, but the reports alone did not provide 
the basis for our findings as noted in the ``Info Source'' column of 
the AOGA ITR--Case Studies Summary Table--061621, document ID FWS-R7-
ES-2021-0037-0011.
    Comment 63: One commenter suggested that the Service should clarify 
the explanation for not classifying disturbance during early denning 
that did not result in den abandonment as take by Level A harassment.
    Response: The early denning period begins with the birth of cubs 
and ends 60 days after birth. Because cubs cannot survive outside the 
den prior to reaching 60 days of age, any exposure during early denning 
that resulted in an emergence was classified as lethal take. Of the 10 
cases in the repeated-exposure category that occurred during the late 
denning period, 2 resulted in cub mortality; in the other 8 cases, 
exposures did not result in emergences--the bears remained in their 
dens until after 13 February, the date that marked the end of the early 
denning period in cases where cub age was not known. Although possible, 
no studies have clearly demonstrated latent effects of disturbance on 
denning bears that did not respond to the disturbance in observable 
manners. In these eight cases, negative response (e.g., early 
emergence) were not observed during early denning. The purpose of 
evaluating these case studies was to inform the probabilities of 
responses to exposures during different periods. In this case, 
simulated dens that were exposed to repeated exposures before cubs 
reached 60 days of age had a 20% probability, on average, of resulting 
in cub mortality and an 80% probability of remaining in the den until 
the beginning of the late denning period.
    Comment 64: One commenter suggested that the Service should clarify 
their explanation for the dates assigned to the early denning period.
    Response: We used the best available information to inform average 
parturition date of 15 December. Messier et al. (1994) concluded that a 
majority of births occurred before or around 15 December as indicated 
by the drop in activity levels of instrumented females.

[[Page 43052]]

    Comment 65: One commenter suggested that the Service should collect 
more extensive followup information on polar bear den disturbance case 
studies in order to determine whether cubs survived a den disturbance 
event.
    Response: For most of the case studies, we had documentation of 
only the immediate outcome of the exposure to a disturbance, which was 
sufficient for determining the immediate outcome. For most cases, there 
is no documentation of the outcome of the cubs beyond the immediate 
timeframe of the disturbance. We used the best available information, 
and it would not be appropriate to assume an outcome in the absence of 
information.
    Comment 66: Several commenters suggested that the Service did not 
adequately consider the possibility of lethal take or serious injury 
take by Level A harassment arising from direct contact of a vehicle 
with a den and varying reactions of denning animals to vehicles in 
close proximity.
    Response: We do not use only Smith et al. (2020) for estimates of 
AIR efficacy, but rather we include the results from Smith et al. 
(2020) and Amstrup et al. (2004) in our analysis, as well as a new 
study on artificial dens (Woodruff and Wilson 2021). We do take into 
account potential disturbance from ground noise and vibrations from 
drill and exploration in the form of our disturbance probabilities 
derived from our review of relevant case studies. While it is true that 
Amstrup et al. (2004) suggest helicopters may have higher detection 
rates than fixed-wing aircraft, the average detection rates from 
Amstrup et al. (2004) do not differ significantly from results obtained 
with a fixed-wing aircraft (Smith et al. 2020) when accounting for the 
proportion of dens that are unlikely to be available for detection 
given snow depth. Additionally, AOGA proposed using only fixed-wing 
aircraft, so that is what we considered in our analysis. The EA serves 
to assess the impacts of the Federal action of issuing the ITR. The ITR 
does not authorize the specified activities; therefore, the EA focuses 
its discussion on the effects of takes to be authorized pursuant to the 
ITR. The impacts from the activities themselves could proceed without 
MMPA coverage at the discretion of the applicant and are not effects of 
the Proposed Action, but were nevertheless considered as part of the 
environmental baseline and in the cumulative impacts analysis.
    Based on the output of the den disturbance analysis, we estimated 
the number of dens and probability of >=1 den being run over by 
equipment used while driving off established roads in the project area. 
Because it is possible to run over dens only when driving off 
established roads, we restricted our analysis to only those simulated 
dens that occurred adjacent to proposed ice roads, tundra travel 
routes, and seismic grids. Because the applicant did not specify how 
seismic grids would be laid out, we followed a similar approach as 
Wilson and Durner (2020) and simulated seismic grids across the high- 
and low-density seismic areas (Fig. 7). We simulated E-W and N-S 
seismic track lines, each separated by 201.2 m (660 ft). We assumed 
vehicles traveling seismic grids, ice roads, and tundra travel routes 
would have a width of 3.4 m (11.2 ft; Wilson and Durner 2020).
    For each iteration of the model, we determined which dens occurred 
within the footprint (i.e., 3.4 m) of the different movement paths. We 
then determined if dens had been identified by AIR surveys. If a den 
was identified on an AIR survey, we excluded it from further analysis. 
Lastly, we restricted the set of dens available to be run over to those 
that did not previously have a take by Level A harassment or lethal 
take assigned to it during the early or late denning periods. That is, 
those dens that did not previously respond to disturbance and, 
therefore, would be vulnerable to being run over by equipment. We did 
not consider the potential for running over dens during the den 
establishment period or post-emergence period because during both of 
these periods bears are known to be on the surface and would likely be 
visible to operators and the bears would be able to readily detect the 
potential risk of the vehicles and respond appropriately.
    Our approach for estimating the number of dens potentially run over 
by equipment can be considered conservative because it does not account 
for the fact that operators have stated they will avoid crossing 
denning habitat whenever possible, which would further reduce the 
probability of running over a den. Similarly, the seismic grids we 
simulated likely cover a greater area than a normal seismic layout, but 
because information was not provided by the applicant, we used the more 
liberal layout.
    We found that the probability of running over a den is exceedingly 
low each year of the ITR. The probability of running over >=1 den each 
winter ranged from 0.0041 to 0.0059. This makes sense given the 
existing mitigation measures analyzed take some dens off the table 
because they are found prior to the commencement of activities that 
could run over them. Additionally, the actual footprint of vehicles is 
very small compared to the scale of the project area, thus, there is a 
very low risk to begin with that a den would even overlap a vehicle's 
footprint on the landscape.
    When additional mitigation measures proposed by the applicant are 
considered, including the avoidance of steep terrain and the training 
of personnel for identifying den site characteristics, which cannot be 
quantified, the Service determined that the probability of running over 
a den was sufficiently small so that it could be dismissed and 
therefore was not included in this ITR.
    Comment 67: One commenter suggested that the Service should use 
randomized case studies for their polar bear denning analysis.
    Response: It is not clear exactly what the commenter means by the 
``case studies used for the case studies are not randomized.'' There 
was no way to use ``randomized'' data in this case. The use of 
randomized data in this case would require conducting a study by radio-
collaring denning females and then observing their response to any den 
disturbance. This runs the risk of substantial disturbance in both the 
capture and collaring (see Amstrup 1993, Lunn et al. 2004) and the 
observation (see Smith et al. 2007, 2010, 2013; Robinson 2014). Instead 
we relied on the case studies, the best available information, to 
inform our model and take probabilities.
    Comment 68: One commenter suggested that the Service should 
reevaluate the most recent scientific evidence on the number of land-
based dens for the SBS polar bear stock to avoid underestimating the 
number of dens used for the denning analysis.
    Response: We are not sure what leads the commenter to believe that 
the results of Atwood et al. (2020) are an underestimate of the number 
of dens on shore. Atwood et al. (2020) represents the best available 
science and updates the approach developed by Wilson and Durner (2020) 
to incorporate newer data that was not available for Wilson and Durner 
(2020) and which does a better job incorporating uncertainty into the 
parameters used in the approach. The reason Atwood et al. (2020) is 
used over Wilson and Durner (2020) is two-fold. First, an updated den 
catalogue (i.e., Durner et al. 2020) wasn't available when Wilson and 
Durner (2020) conducted their analysis. This new set of dens is the 
primary reason that the estimate from Atwood et al. differs from Wilson 
and Durner. Second, multiple public comments on the analysis of Wilson 
and Durner noted that uncertainty in underlying parameters

[[Page 43053]]

were not adequately accounted for. Atwood et al. (2020) overcame this 
problem to present a more robust estimate. We agree with the commenter 
that, in the long term, land-based denning is likely to increase due to 
loss of sea ice. However, the most recent study of land-based denning 
in the SBS, Olson et al. (2017) found that rates of land-based denning 
have been constant (i.e., not statistically different) between the 
periods 1996-2006 and 2007-2013. Given that the lowest sea ice minimum 
extent was observed in 2012, it's unlikely that there has been a 
significant increase in land-based denning since the data used in Olson 
et al. (2017).
    Comment 69: One commenter suggested the Service should consider 
including more recent years of denning data in their denning analysis 
in order to account for the increased number of land-based dens.
    Response: Atwood et al. (2020) are clear about their methods and 
what data they used to calculate the 54% of dens occurring on land. 
This estimate conforms to those found in Olson et al. (2017), which is 
the most recently published study on the percent of SBS bears denning 
on land. Olson et al. (2017) found that on average, in the period 1996-
2006, 54% of bears in the SBS denned on land, and in the period 2007-
2013, 55% denned on land. Thus, these data nearly perfectly conform to 
the values used by Atwood et al. (2020; which also included uncertainty 
around those estimates). The reason Atwood only used data through 2015 
is because that is the last year when bears received GPS collars, which 
are required to obtain an unbiased estimate of the distribution of 
denning. The graph the commenters present in their letter is not an 
accurate way to represent the data in the den catalogue. While it's 
true that there are additional years of dens in the den catalogue, 
beyond 2015 they are based on firsthand observations, which are going 
to show a positive bias towards land-based dens given that limited 
search effort is conducted offshore. Thus, the best available data are 
used by Atwood et al. 2020, and the approach used by the commenters is 
likely biased high and not a proper way to summarize the data.
    Comment 70: One commenter suggested that the Service should clarify 
their methods for accounting for the variation and uncertainty in their 
polar bear population estimate and the interannual variation in the 
number of denning female polar bears that was used in the denning 
analysis.
    Response: We agree that Wilson and Durner (2020) failed to account 
for uncertainty associated with many of the underlying parameters used 
to estimate the number of dens on shore. That is why we relied on the 
estimate provided by Atwood et al. (2020) that does account for that 
uncertainty. The uncertainty accounted for by Atwood et al. (2020) 
incorporates annual variability in environmental conditions, which 
could lead to differences in the use of land. So, the Atwood et al. 
(2020) methods and results are robust to the issues presented by the 
commenter.
    Comment 71: One commenter suggested that the Service should 
consider accounting for the number of dens containing females without 
cubs and reevaluating the den emergence date to include only successful 
dens in order to not underestimate the number of takes for denning 
polar bears.
    Response: We disagree that the model does not account for dens with 
only a female bear. In fact we provide some probability (~7%) for a den 
to have 0 cubs. So, we do account for the probability of a female 
emerging without cubs. As for the incorrect skew of emergence dates, we 
again disagree with the commenter. We use den emergence data from Rode 
et al. 2018 and restrict the data to only those that were in the den 
for a sufficient amount of time to indicate the den was more than a 
shelter den. Additionally, even though Rode et al. identify some of the 
dens as not being observed with cubs ~100 days after emergence, it does 
not indicate that the dens were unsuccessful, only that they were later 
observed without cubs. Cubs could easily have been lost between 
emergence and subsequent re-observation. There is currently no way to 
know if a bear emerged without a cub. If those data were available, we 
would include them, but they don't exist.
    Comment 72: One commenter suggested that the Service's denning 
analysis using the Wilson and Durner (2020) model framework does not 
accurately predict impacts to denning polar bears throughout the 
geographic scope for project activities and the model does not account 
for uncertainty in the timing and location of Industry activities that 
may impact denning polar bears.
    Response: We disagree with the commenter that the general framework 
provided by Wilson and Durner (2020) is not suitable for use in this 
ITR. The approach developed by Wilson and Durner (2020) provides a 
general framework for how to incorporate different sources of 
information (as well as associated uncertainty) to analyze how 
different types of activity and infrastructure might affect denning 
polar bears. The specific model discussed in Wilson and Durner (2020) 
has been significantly modified to account for the proposed activities 
in this Request as well as additional sources of information (e.g., 
different denning periods) to increase the realism of the model. While 
it is true that Wilson and Durner (2020) only used the model to analyze 
impacts to polar bears over a smaller activity area, with one type of 
industrial activity, the model we published as part of this ITR clearly 
shows that it is capable of being applied to a larger area and suite of 
activities.
    We also disagree that the ITR does not provide reliable information 
on where and when activities will occur. Both the code and objects 
associated with the den disturbance model and the associated shapefiles 
published with the proposed ITR provide both spatial and temporal 
information on when/where activities will occur. In instances where 
specific dates or areas were unknown (e.g., seismic surveys), we 
accounted for that uncertainty by analyzing the seismic to occur in the 
``worst'' place possible for polar bears (within the range provided by 
AOGA in their Request) as well as accounting for variability in the 
timing of activity within prescribed bounds. We also disagree with the 
commenter that the Service did not account for the possibility of a 
larger seismic survey. This is not true. We clearly state on page 29410 
of the Federal Register publication of the Proposed ITR that during any 
given winter, the areas surveyed would be <766 km\2\ and <1,183 km\2\ 
in the areas identified as ``relatively high'' and ``relatively low'' 
den probabilities, respectively.
    Comment 73: Commenters suggested that the Service should reevaluate 
their take determination for early den departures as potentially lethal 
take for polar bear cubs.
    Response: We do allow for potential survival consequence from early 
emergence. In fact, if a den is disturbed that leads to early 
emergence, cubs are always given a serious take by Level A harassment. 
There are currently no data to support that an early departure from the 
den itself leads to reduced survival. That would take a similar-type 
analysis that Rode et al. (2018) conducted. While we agree cubs have 
been observed being killed by conspecifics and other predators after 
leaving the den site, there is currently no linkage with time spent at 
the den post-emergence and pre-departure.
    Comment 74: One commenter suggested that the Service should clarify 
their explanation for how non-serious take by Level A harassment was

[[Page 43054]]

accounted for in the Service's take determinations.
    Response: Table 8 shows the breakdown of estimated take by the 
level of take. We provided this table so readers could see the relative 
differences. As is discussed in the description of take by Level A 
harassment within the proposed rule, Level A harassment (either non-
serious or serious) to bears on the surface is extremely rare within 
the ITR region, and no Level A harassment to Pacific walruses has been 
reported in the Beaufort Sea ITR region. Thus, the best available 
information does not support Level A harassment to occur due to surface 
interactions for polar bears, or in general for walrus given the 
proposed activities.
    Comment 75: One commenter suggested that the Service should 
consider the probability of take by Level A harassment for polar bear 
adult females during a den disturbance event.
    Response: We disagree that there is a significant probability of an 
adult female experiencing Level A harassment due to disturbance at the 
den site. During our review of case studies, we observed no examples 
where an adult female experienced any sort of harassment that had the 
potential to injure her. There are also no examples that we are aware 
of in the literature. Whereas disruptions to the normal timing of den 
phenology have clearly published negative relationships to cub 
survival, no such relationships exist for adult females.
    Comment 76: One commenter suggested that the Service should clarify 
their explanation for the impact sources assessed in the denning 
analysis and whether take by Level A harassment and lethal take are 
underestimated.
    Response: We disagree that our use of disturbance probabilities 
from the ``repeated'' set of probabilities is inappropriate. During our 
review of case studies used to estimate these probabilities, the types 
of activity classified as ``repeated'' are analogous to those expected 
from seismic surveys. The commenter's assessment that any activity 
``will experience the disturbance first as a discrete event'' is 
inaccurate. For the case studies we reviewed, the same (inaccurate) 
argument could be made, but as a result the probabilities in the 
repeated category inherently incorporate that first exposure and its 
potential to cause disturbance. Based on our definition of what 
constituted repeated exposure, and therefore whether a case study was 
classified as repeated/discrete, it would be inappropriate to apply the 
discrete probabilities to seismic given the unquestionable repeated 
nature of those activities. We should also note that depending on a 
simulated den's phenology and the proposed dates of seismic activity, 
dens could have disturbance applied multiple times (if previous 
exposures did not result in lethal take or take by Level A harassment 
response).
    We also disagree with the commenter that our decisions on how case 
studies were classified was arbitrary. We developed clear rules based 
on a large body of scientific literature to help classify whether a 
response to an exposure was larger than expected under unexposed 
conditions. Similarly, we did not ``arbitrarily'' decide when to 
exclude case studies from consideration. A significant amount of 
deliberation went into the assessment of each case study, and only two 
factors would disqualify a case study from being included in the final 
probability calculations: (1) There was insufficient information to 
identify when disturbance occurred or what the outcome was to the den 
under consideration, or (2) the type of activity was deemed to be 
outside of the activities proposed by AOGA (e.g., physical capture of 
polar bears in dens). We disagree with the commenter's assessment that 
the Service was overly arbitrary in how the different case studies were 
summarized. They cite our assessment of case study 47 as an example of 
there being sufficient information but the Service classifying it as 
'insufficient information'. The reality is, this case study did not 
provide information on how far the crews were from the den, nor the 
date that the bears emerged from the den. Given our published criteria, 
we couldn't reliably assign take to this case. We agree that take was 
certainly possible, but insufficient information precluded us from 
coming to that conclusion.
    The commenter highlights case study 7 as another example. Yet, 
there were clear reasons we didn't include this case study. First, it 
was unclear whether the ``hunter'' identified in the case study 
actually observed the same bear as Amstrup did given the time lapse 
between observations. That would be another explanation for why there 
were no cubs observed. Thus, there was incomplete information to fully 
assess this case study. We disagree with the commenter that it is 
inappropriate to assume that once a Level A harassment or lethal take 
occurs that subsequent harassment/take is not considered. This really 
applies to only one period, the late denning period, because lethal 
take/take by Level A harassment is not possible in the den 
establishment period; the only disturbance outcome during the early 
denning period is ``lethal'' thus future take/harassment is not 
possible, and during the post-emergence period, any additional take is 
accounted for in the surface analysis (i.e., not the denning analysis). 
During the late denning period, we believe it is appropriate to not 
consider additional harassment/take if Level A harassment is simulated 
to occur. In the late denning period, Level A harassment is considered 
serious take by Level A harassment, thus it already assumes a likely 
lethal outcome. Thus, applying additional lethal take when it has 
already been accounted for is not appropriate.
    Comment 77: One commenter suggested that the Service should 
consider the size of cubs, which may indicate poor body condition and 
lower survival likelihood, as factors to determine take for den 
disturbance events.
    Response: The commenter outlines some well-established ecological 
relationships (e.g., cub size and survival, sea ice and body 
condition), but fails to understand the purpose of the case study 
analysis, the underlying assumptions, and how the results are utilized 
in the simulation model. The case study analysis was used to estimate 
the probability of a disturbance eliciting a specific response during 
each denning period; we then used those probabilities in the model to 
determine how simulated dens would respond to disturbances at specific 
times. For example, from the case study analysis, we found that dens 
exposed to a discrete exposure during the late denning period resulted 
in early emergences 90.9% of the time. Consequently, in the simulation 
model, dens exposed to a discrete exposure between the time cubs were 
60 day old and their intended emergence date had a 90.9% chance, on 
average, of emerging early. Because the best available science 
indicates that early emergences are associated with decreased cub 
survival (e.g., Rode et al. 2018), we classified those dens as 
incurring serious take by Level A harassment. The commenter argues that 
cubs today are smaller than in the past because of environmental 
changes and are therefore more likely to be impacted negatively by 
early emergences and departures. Although that assertion may be 
correct, no studies have demonstrated that cub size influences when a 
disturbance elicits an early emergence, and no studies have evaluated 
the relationship between cub size at emergence and survival probability 
in a manner that would

[[Page 43055]]

allow us to refine our treatment of early emergences (e.g., separating 
those that ultimately resulted in mortality from those that did not). 
See below for our response to the ``known outcomes'' statement.
    Comment 78: One commenter suggested that the Service should 
consider followup information from den case studies and reevaluate take 
determinations based on latent effects of den disturbance to polar bear 
cubs.
    Response: The commenter does not indicate which cases they consider 
to have ``known outcomes'' or ``followup,'' so we cannot address those 
directly. We are also unclear about which cases correspond to claims 
about observer opinion on cub size and survival. For example, the 
commenter states that ``observers thought the cub of another female was 
too small to survive,'' and the outcome for this case was an observed 
behavioral response. This statement seems to correspond with a case 
where the final outcome was `insufficient information' and was not used 
in calculating the response probabilities. It is possible that the 
cases the commenter is referring to elicited no observable response in 
a particular period but were subjected to disturbances in later periods 
that did elicit negative responses (the commenter's claim that a bear 
that departed a den without cubs was classified as a non-serious 
response supports this possibility because that classification would 
not be possible during a period when the bear left the den).
    The general argument the commenter is expressing seems to be that 
latent effects from disturbance could manifest later, and, therefore, 
our harassment classifications for early departure in the post-
emergence period should be higher (presumably serious take by Level A 
harassment as opposed to non-serious take by Level A harassment). 
Survival of cubs-of-the-year is often low, and this is especially true 
in the Southern Beaufort Sea subpopulation, even for those cubs from 
undisturbed dens. It should be expected, therefore, that some cubs that 
departed den sites early during the post-emergence period would die 
before reaching independence and others would not. Although an early 
departure from a den due to disturbance may incur a fitness cost (hence 
the non-serious take by Level A harassment classification), the 
probability or degree of that cost has not been evaluated. 
Consequently, assigning a higher level of take (i.e., serious take by 
Level A harassment) is inappropriate because that would signify an 
injury that is likely to result in mortality.
    Comment 79: One commenter suggested that the Service should clarify 
their explanation for the dates to distinguish the early denning period 
from the late denning period because this date may be later.
    Response: The specific data range cited by the commenter is only 
related to the review of case studies because individual birth dates 
couldn't be known. We therefore had to rely on means obtained from the 
scientific literature to represent the natural range of den phenology 
data. The actual analysis to estimate disturbance and take to denning 
bears allowed for variability in denning phenology dates that match the 
published range of values. The actual start/end dates for the given 
denning periods in the analysis are based on the simulated dates for 
specific life history events. For example, bears are given a simulated 
birth date ranging from 1 December to 15 January (i.e., the start of 
the early denning period). The late denning period then begins on the 
date those simulated cubs turn 60 days old.
    Comment 80: One commenter suggested that the Service should 
consider whether climate change may cause a greater impact on polar 
bears that relocate their dens in response to disturbance.
    Response: While we agree with the commenter that these types of 
relationships are conceivable, we are unaware of any information to 
support or document these claims. Further, these statements are just 
conjectures, and it's equally feasible that females have sufficient 
energetic reserves to find a new den site given that they already spend 
energy scouting for ideal den sites. We are therefore required to use 
the currently best-available information, which indicates minimal 
impacts to denning females if forced to find a new den site after being 
disturbed.
    Comment 81: One commenter suggested that the Service should 
consider whether the opportunistically collected data on polar bear 
dens is an accurate representation of polar bear responses to den 
disturbance and whether the Service developed accurate model 
assumptions based on polar bear responses to den disturbance.
    Response: We use the best available information to calculate the 
probabilities of different levels of response to industrial activities. 
It is important to consider the variability across individuals and how 
they respond. The Service does not assume only minor behavioral 
responses, but provides estimates varying from lethal take of cubs to 
minor behavioral responses because that is the range of responses 
observed in real-world examples.
    Comment 82: One commenter suggested that the Service should 
classify all cases in which denning polar bears are disturbed by 
industry activities as take by Level A harassment.
    Response: We agree that there are sufficient data to show 
variability in responses to human activity. That is what we show with 
our case study assessment (i.e., see table 7 with disturbance 
probabilities). There's always some probability of no response and 
others of varying levels of disturbance. We also agree that the case 
study review didn't allow for accounting for bears that chose not to 
den near existing infrastructure/activity nor every single den that may 
have been adjacent to activities but going undetected. There is no way 
to ever detect all dens. However, we do account for bears that avoid 
denning near infrastructure. We detail this on pages 86 FR 29407-29408 
of the proposed rule (June 1, 2021). Using historical den data, we 
found that dens occurred less frequently than expected adjacent to 
existing infrastructure, so that is accounted for in the model. It is 
simply an assumption (with no published information to back it up) that 
bears choosing to den away from Industry would be more sensitive to 
disturbance. Again, it may be the case, but it's also possible that it 
is not. So, without any data to support this claim, it would be 
inappropriate to incorporate it into the analysis. We disagree that we 
should treat all bears that are exposed to disturbance as having the 
potential for injury or death. The case study data and other published 
studies (e.g., Amstrup 1993, Larson et al. 2020) clearly show this is 
not the case. And, as the commenter suggests, we know that there is a 
great deal of variability in responses to human activity. So, it would 
be inappropriate, and not based on the best-available science, to 
assume all bears are subject to potential injury or death.
    Comment 83: One commenter suggested that the Service should 
consider that specific Industry activities may have different levels of 
impact on denning polar bears.
    Response: The probabilities in Table 7 are drawn from a wide range 
of activities ranging from very minimal human activity, to very 
invasive. In our model framework, the varied and multiple sources of 
activity are accounted for. Briefly, a den is allowed to be exposed to 
disturbance until it is either disturbed and assigned a take by Level A 
harassment or greater, or bears emerge and depart their den by the

[[Page 43056]]

expected (i.e., undisturbed) dates. Thus, we do account for the suite 
of activities that can disturb a den. We agree with the commenter that 
no studies exist looking at how denning bears respond to specific 
activities. We agree that it would be ideal to know the probability of 
different levels of response to different types of activity. 
Unfortunately, those data do not currently exist. While Owen et al. 
(2020) shows varied distances that denning bears can detect different 
types of activities, there are no associated data with the distances at 
which bears will display a disturbance response once a stimulus is 
detected. So, we had to take the average approach across activity 
types. This likely leads to overestimate of take for more limited 
activities and underestimate of take for more significant activities. 
But on average, the results would be accurate.
    Comment 84: One commenter suggested that the Service should 
consider individual variability and local weather conditions when 
determining the time period in which polar bears emerge and depart from 
their dens.
    Response: We agree that local conditions may influence when bears 
choose to depart their den sites. Unfortunately those relationships 
have not been established so are currently just conjecture. We use the 
best available data to establish the range of emergence and departure 
dates so they capture the natural range of variability in when bears 
decide to emerge from and depart their dens. We simulate each 
individual den with specific dates when key activities occur (e.g., 
emergence, departure), so we incorporate the individual decision on 
what constitutes ``early'' and do not base it on an overall population-
level mean.
    Comment 85: One commenter suggested that the Service should 
consider Industry impacts on mother polar bears and cubs as they are 
traveling from den sites to the sea ice.
    Response: The encounter rates used by the Service were generated 
using records of polar bear encounters that encompass the dates when 
sows and cubs are likely moving from den sites to the sea ice (i.e., 
the best available information). Thus, these individuals are currently 
incorporated in the take estimates presented in the ITR. While we agree 
that the type of encounter described by the commenter is possible, we 
found no evidence in the encounter data used that shows instances of 
females abandoning cubs while after departing the den site as a result 
of disturbance from industrial activities. This indicates these types 
of impacts are likely very rare. The research operation flights 
referenced by the commenter are typically at a much lower elevation 
than industrial flights, and the potential take of these flights has 
been discussed in Aircraft Impact to Surface Bears.
    Comment 86: Two commenters suggested that the Service should 
clarify the operational constraints of Industry vehicles in polar bear 
denning habitat and whether vehicle activity was evaluated as an impact 
factor in the denning analysis.
    Response: We disagree with the commenter that an attempt would be 
made to identify denning habitat in the winter once snow fell. Instead, 
we rely on studies that have already occurred to identify areas with 
suitable conditions for capturing snow. The commenter cites the 
comments from Steve Amstrup, yet he is a co-author on most of the 
studies that have identified these areas in advance of activities. The 
overall probability of running over a den is exceptionally small. 
First, two to three AIR surveys must occur before activity commences in 
an area. Given the detection probability of AIR, this leads to 65-80% 
(on average) of dens being detected. Then, given the overall avoidance 
by Industry of crossing areas suitable for denning and the relatively 
small footprint of off-road travel in the project area, and the 
likelihood of bears abandoning a den before vehicles physically run 
over it leads to a very low risk of this occurring. Operators will be 
required to have and use the USGS denning habitat layer to avoid 
denning habitat whenever possible. See also Analysis and Assumptions 
Regarding Den Collapse, above.
    Comment 87: One commenter suggested that there is insufficient 
information regarding the vulnerability of denning habitat to vehicle 
travel, and that the Service should restrict Industry vehicle 
activities in all potential polar bear denning habitat defined by USGS 
in order to reduce impacts to denning polar bears.
    Response: We disagree that there is insufficient information in the 
ITR to ascertain how much denning habitat will be vulnerable to vehicle 
travel. We provided all of the tundra travel, ice road, and seismic 
survey region spatial data that are part of this ITR. One could easily 
use those files and calculate how much denning habitat might be exposed 
to activities. We note, however, that just because there is sufficient 
topographic relief to capture snow doesn't mean that bears will use it 
for denning. Thus, it's inappropriate to consider any area with 
sufficient slope to be off limits. That requires some additional 
assessment of the probability of a bear using that area. We also 
provided the layer on relative probability of denning. We account for 
the number of dens that go undetected and are likely to be disturbed by 
activities. See also comments and responses above.
    Comment 88: Two commenters suggested that the Service should 
evaluate the limitations of ground-based den detection, such as 
difficulty visibly distinguishing dens and suitable denning habitat in 
winter and low efficacy of hand-held infrared detectors, as part of the 
Service's risk assessment for industry vehicles causing den 
disturbance.
    Response: We disagree. The applicant stated that they would avoid 
steep banks so we also considered this in our analysis, which, along 
with the other mitigation measures in place (i.e., aerial infrared 
surveys, trained observers, etc.) reduced the probability of running 
over a den to such a small level that it could be dismissed and not 
considered in the analysis. See also the comments and responses above.
    Comment 89: One commenter suggested that the Service should clarify 
how the multiple disturbance events during seismic surveys are 
evaluated in order to determine impacts to denning polar bears and 
whether the Service's assumption for seismic survey impacts accurately 
represents realistic impacts.
    Response: The proposed ITR does account for the activity associated 
with advance crews during seismic surveys. The start date for seismic 
activities is when the advance crews first enter the seismic areas, so 
those are the first dates that dens are exposed to disturbance and a 
determination is made (in the model framework) whether a den is 
disturbed or not. The response probabilities we used for seismic were 
derived from case studies where the activities occurred repeatedly, 
similar to activities related to seismic surveys. Thus, the repeated 
activities associated with seismic were accounted for based on the set 
of response probabilities we used.
    Comment 90: One commenter suggests that the Service should account 
for take of polar bears during AIR calibration flights, in which 
aircraft calibrate their infrared instruments over known polar bear 
dens.
    Response: The AOGA did not include flights over known dens on 
barrier islands in their Request for an ITR. Thus, potential take from 
this practice was not analyzed, and any potential take that may occur 
as a result of these calibration flights would not be covered by the 
ITR.
    Comment 91: One commenter suggested that the Service should more 
thoroughly evaluate the distance at

[[Page 43057]]

which take is estimated as well as fully evaluate whether additional 
take could result from activities requisite to tundra travel.
    Response: As stated in the discussion of ``Impact Area'' within the 
ITR, behavioral response rates of polar bears to disturbances are 
highly variable, and data that support the relationship between 
distance to bears and disturbance is limited. The Service has relied 
upon a number of studies, representing the best available science, to 
arrive at the potential impact area of 1.6 km, including the study 
cited by the commenter. The authors found that female polar bears with 
cubs (the most conservative group observed) began to walk or run away 
at a mean distance of 1,534 m. Importantly, these bears were reacting 
to researchers directly approaching them with snowmobiles, which is an 
intentional (as opposed to incidental) act, and simply walking away 
from an area may not rise to the threshold of Level B harassment under 
the MMPA. The rates of harassment used to quantitatively estimate 
potential take were developed using a dataset that includes 
observations of human-polar bear encounters on the North Slope of 
Alaska. These encounters include observations of polar bear responses 
to snowmachines, trucks, Tuckers, bulldozers, and other industrial 
equipment. As such, the effects of these noise sources are incorporated 
into the Service's take estimates.
    Comment 92: One commenter suggested that the Service should clarify 
their take evaluation of repeated disturbances to the same polar bear.
    Response: As the Service described in their description of critical 
assumptions in the ITR, the available studies of polar bear behavior 
indicate that the intensity of polar bear reaction to noise disturbance 
may be based on previous interactions, sex, age, and maternal status. 
However, as it is impossible (without unique identifiers such as 
collars or ear tags) to record repeated observations of the same bear, 
the Service has estimated the number of Level B harassment events from 
the proposed activities using the assumption that each event involves a 
different bear. The Service acknowledges bears may be harassed 
repeatedly. Each harassment event is classified as a separate take and 
is included in small numbers determinations.
    Comment 93: Commenters suggested that the Service did not have 
information on the specific Industry activities planned during this 
regulation period, which is needed to make the Service's 
determinations.
    Response: The Service has provided detailed descriptions of the 
proposed activities within the ITR. We have also provided the public 
with geospatial files of these proposed activities during the public 
comment period in additional to monthly human occupancy rates. Further, 
under Description of Letters of Authorization (LOAs) in the ITR, the 
Service explains that requests for LOAs must be consistent with the 
activity descriptions and mitigation and monitoring requirements of the 
ITR. Thus, the Service used detailed descriptions of what, where, and 
when activities will occur to calculate quantitative take estimates.
    Comment 94: One commenter suggested that the Service should address 
how uncertainty and natural environmental variation are accounted for 
in the surface interaction model.
    Response: The Service used best available science to estimate ice 
season encounter rates. As the commenter has noted, observation in the 
Arctic during polar night or severe weather conditions is difficult, 
and as such there are no known studies that have conducted site-
specific surveys in the winter months within the project area. The 
Service used the most comprehensive database available, its LOA 
database, to develop encounter rates and quantitative take estimates. 
Statistical uncertainty was accounted for when developing level B 
harassment rates. Furthermore, by averaging the number of encounters 
over the past 5 years, the Service has encompassed year-to-year 
differences in bear density.
    Comment 95: One commenter suggested that the Service should 
consider whether take by Level A harassment will occur if Industry-
related noise disturbs walruses hauled out on land causing them to 
stampede towards the water and potentially trampling walruses during 
the stampede and the basis for the take estimate.
    Response: The Service does not dispute that walruses may stampede 
if disturbed while hauled out on land. This behavior was discussed in 
the proposed ITR under Description of Marine Mammals in the Specified 
Geographic Region: Pacific Walruses. However, as is also noted in that 
section, Pacific walruses are extralimital in the Southern Beaufort Sea 
and are rarely encountered. There are no records of haulouts within the 
area of proposed activities. Thus, using the best available records of 
Pacific walrus abundance in the South Beaufort Sea, the Service 
estimated that the potential existed for a group of up to 15 walrus to 
be encountered by humans in the project area during the open-water 
season.
    Comment 96: Commenters suggested that the Service should clarify 
how the polar bears' increased use of land in recent years is accounted 
for in the surface interaction model.
    Response: The Service used the best available data to calculate 
encounter and take rates. In ``Description of Marine Mammals in the 
Specified Geographic Region,'' the Service describes an increase in the 
percentage of the Southern Beaufort Sea stock that comes ashore in the 
summer and fall (Atwood et al. 2016). By using an average of 5 years of 
reports, the Service captured variability in the number of encounters 
that may occur year to year. By using encounters in the period 2014-
2018, the Service has generated encounter rates that represent 
contemporary terrestrial habitat use.
    Comment 97: One commenter suggests that the Service underestimated 
potential take and suggests clarification on the explanation for 
determining take from surface interactions.
    Response: We disagree. The Service conducted a robust analysis of 
surface-level interactions related to human-bear encounters. The 
Service discussed that analysis in our Evaluation of Effects of 
Specified Activities on Polar Bears, Pacific Walruses, and Prey 
Species: Polar Bear: Surface Interactions, and we reaffirm that 
analysis in this final rule.
    Comment 98: One commenter suggested that the Service should clarify 
how Industry activity impacts on non-denning polar bears, specifically 
mother bears with cubs traveling to the sea ice after den departure, 
are evaluated as take in the surface interaction analysis.
    Response: The dataset that was used to analyze potential take from 
surface interactions encompassed all recorded human-polar bear 
interactions throughout the year, including the months when sows are 
moving toward the sea ice with cubs of the year. There are no recorded 
interactions in the 2014-2018 dataset between Industry and these bears 
that resulted in Level A harassment. The Service has also accounted for 
these potential interactions when establishing mitigation measures. 
Under the mitigation measures established in the proposed rule, 
Industry must survey for maternal polar bear dens, create exclusion 
zones around known dens, and report all polar bear interactions 
(including those with sows and cubs) to the Service within 48 hours of 
the event.
    Comment 99: One commenter suggested that the Service should clarify 
that infrared methods include both aerial and ground-based technology 
methods in order to provide Industry entities the flexibility to use 
the most

[[Page 43058]]

practicable means for required infrared surveys.
    Response: Ground-based infrared surveys are not directly comparable 
to AIR surveys and should not be considered to have equivalent 
detection rates. We are not aware of any studies that have directly 
estimated infrared detection from ground-based surveys. But studies 
have documented that ground-based infrared is likely to lower detection 
probability given the greater impacts of blowing snow on detection than 
when doing aerial surveys (Robinson et al. 2014). Pedersen et al. 
(2020) found that infrared from a vertical position (i.e., aerial) was 
four times more likely to detect a den than infrared from a horizontal 
position (i.e., from the ground). Given that our analysis was based on 
AOGA's proposal to conduct AIR surveys, we did not estimate what the 
expected level of take would be if ground-based infrared was used 
instead on a case-by-case basis. Based on what has been published on 
the topic, it would not be appropriate to treat ground-based infrared 
detection as equivalent to aerial-based efforts.
    Comment 100: One commenter suggested that the Service should revise 
their language for the time period in which AIR surveys are to be 
conducted in order to allow for flexibility due to poor weather and 
operational complications.
    Response: The results of Wilson and Durner (2020) show that 
specificity in dates when activities occur can significantly affect the 
level of disturbance expected from industrial activities. The Service 
worked with AOGA to find date ranges for AIR that met their constraints 
but that also provided sufficient protection for denning polar bears in 
light of their proposed activities. AOGA stated they were amenable to 
these dates. Unfortunately, the Service's analysis is contingent on AIR 
surveys being conducted within the date ranges in the draft ITR and any 
deviation from those dates could lead to increased levels of take and 
harassment of denning bears. Thus, the Service will not be able to 
accommodate this request.
    Comment 101: One commenter suggested that the Service should 
clarify whether a third AIR survey is required for seismic survey 
activities.
    Response: The Service is requiring three AIR surveys to occur prior 
to all seismic activities. The Service has worked together with the 
applicant to develop mitigation measures that ensure the least 
practicable adverse impact on polar bears. The applicant agreed that 
three surveys are practicable and will be conducted prior to all 
seismic activities as a condition of the LOA.
    Comment 102: One commenter suggested that the Service should 
address whether the reported efficacy of AIR is sufficient to detect 
polar bear dens prior to the commencement of Industry activities.
    Response: We incorporate these different studies cited in the 
comment that rely on aerial surveys to establish our AIR efficacy used 
in the model. We don't assume complete detection of dens, but rather a 
value of 41% (with associated uncertainty). So, we account for the 
inability of an AIR survey to detect all dens in our modeling 
framework, and the value we use is actually lower than that published 
in Smith et al. (2020). Robinson et al. (2014) is inappropriate to 
include because it was based on hand-held ground-based infrared, which 
is not as effective as aerial surveys, and they do not provide an 
estimate of detection probability. But we do include the results from 
Smith et al. (2020) and Amstrup et al. (2004) in our analysis, as well 
as a new study on artificial dens (Woodruff and Wilson 2021).
    Comment 103: One commenter suggested that the Service should 
consider how the variation in weather conditions will affect the 
efficacy of AIR to detect polar bear dens.
    Response: The AIR efficacy values we use are from a suite of 
weather conditions and not just optimal conditions, so they cover the 
range of possible conditions that surveys are flown. For example, 
Amstrup et al. 2004 found that AIR efficacy was >80% for optimal 
weather conditions, but we don't use that value. We use the average AIR 
efficacy, which is closer to 55% for Amstrup. Because a range of 
weather conditions is used, our estimates are able to provide inference 
across those conditions. Additionally, while we agree that weather 
conditions in northern Alaska are likely to change with climate change, 
surveys are still required to be flown under conditions that have been 
found to be suitable.
    Comment 104: One commenter suggested that the Service should 
address that polar bear dens can remain undetected despite multiple AIR 
surveys in the area and whether the requirement for multiple AIR 
surveys will effectively increase the den detection rate.
    Response: We agree that more AIR surveys do not make them more 
effective. Dens in the model can continue to go undetected even after 
multiple surveys. But, the laws of probability indicate that if you do 
the surveys multiple times over a den that is available to be detected, 
the probability that it will be detected (at least once) increases. 
Similar to Amstrup et al. (2004), when you apply two AIR surveys to our 
simulated dens, the overall probability of detection is only ~65%. So, 
it is incorrect that more surveys do not equal more dens detected.
    Comment 105: One commenter suggested that the Service should 
address how the efficacy of AIR for detecting dens with various depths 
of snow cover was accounted for in their den detection model.
    Response: We don't assume that dens with snow depth >100 cm can't 
be detected for the current analysis. AIR efficacy rates are for all 
dens (i.e., independent of snow depth), so by default includes those 
dens that are unable to be detected for whatever reason. Smith et al. 
(2020) did not account for snow depth in their detection probability, 
and Woodruff and Wilson (2021) did not find a relationship between 
detection and snow depth. That is why we don't take into account snow 
depth for the approach we took in this model.
    Comment 106: One commenter suggested that the Service should 
clarify their explanation for the sources used to inform their 
estimation of den detection probability and how uncertainty was 
accounted for during their estimation of den detection probability.
    Response: Our approach is not arbitrary. We are aware of only three 
studies that utilize AIR detection estimates. Although Scheidler and 
Perham published a report on aerial survey detections, they had 
significant issues (published in their report) that precluded our use 
of their results. Other studies use drones (Pedersen et al. 2020) or 
handheld infrared (Robinson et al. 2014), which are likely not 
comparable and don't actually provide detection probabilities. With 
respect to the Woodruff and Wilson (2021) study, the Service published 
the white paper to give readers details on how the probabilities were 
derived, but the greater context of the study was not provided because 
it is currently under peer-review. Many limitations to the study make 
the use of the lower estimate questionable (e.g., onboard navigation 
equipment was not allowed for observers compared to real surveys). 
Thus, we used the detection estimate from that study as the most 
reliable (i.e., dens that were determined to have been covered by the 
AIR camera). So, the decision was not arbitrary, but based on our in-
depth knowledge of the study and its limitations. Lastly, the Service 
doesn't ignore the uncertainty in den

[[Page 43059]]

detection depending on people on the survey crew. Those differences are 
already incorporated into the estimates in Woodruff and Wilson (2021). 
All three surveyors had significant experience using AIR to detect 
polar bear dens. Thus, our estimate represents the average detection 
rates for people with training in the use of AIR to detect polar bear 
dens.
    Comment 107: One commenter suggested that the Service 
underestimated the number of polar bear dens that would remain 
undetected, which may affect their take estimations.
    Response: First, the den model does not assume only 52 dens are on 
the land in any given year. That is the mean value we used, but we 
accounted for the uncertainty in this estimate, so the number of dens 
simulated during each iteration is highly variable. We agree with the 
assessment by the commenter that the results of Woodruff and Wilson 
(2021) show that only 50% of dens were detected at least once during 
the study. While that is not the correct metric to use in the analysis, 
our approach to estimating infrared efficacy took into account the 
lower detection rates for this study in combination with the two other 
studies that provide an aerial detection rate of dens with AIR.
    Comment 108: Two commenters suggested that the Service should 
clarify the optimal weather conditions for AIR surveys to be conducted 
in order to avoid AIR surveys being conducted in suboptimal conditions 
and affecting polar bear den detection rates.
    Response: The estimates of AIR detection used in the analysis were 
not obtained under optimal weather conditions, but under a range of 
weather conditions that AIR surveys are possible. Thus, optimal weather 
conditions are not required based on the estimates of detection we 
used. That said, it has been standard practice for Industry operators 
to conduct their AIR surveys within parameters outlined by Amstrup et 
al., 2004 and York et al., 2004. This has been added to the Mitigation 
and Monitoring requirements in the ITR.
    Comment 109: The regulatory text in the proposed rule at Sec.  
18.120(a) describes the offshore boundary of the ITR as matching the 
boundary of the BOEM Beaufort Sea Planning area. However, the preamble 
text and the maps in both the preamble and the proposed rule describe 
the geographic region as extending 80.5 km (50 mi) offshore rather than 
matching the BOEM Planning Area boundary. This discrepancy should be 
corrected.
    Response: We agree and have clarified this final rule so that the 
preamble text reflects the boundaries of the geographic area in the 
regulatory language.
    Comment 110: One commenter suggested that the Service should 
request that helicopters be used for AIR surveys because it has been 
reported that polar bear den detection rates are higher when 
helicopters are used compared to fixed-wing aircraft.
    Response: Use of helicopters to survey active dens might actually 
lead to greater levels of disturbance and take than with fixed-wing 
aircraft. While it's true that helicopters are more maneuverable than 
airplanes, we have not seen any published data (only conjecture) that 
detection rates for dens are higher when a helicopter is used vs. a 
fixed-wing aircraft. Interestingly, Amstrup et al. (2004) used a 
helicopter and Smith et al. (2020) used a fixed-wing, yet when 
accounting for likely undetectable dens, Amstrup et al. (2004) has a 
mean detection of ~55% compared to Smith et al. (2020)'s ~45%. These 
are likely statistically insignificant as the 95% CI for the Amstrup et 
al. (2004) estimate largely overlaps the Smith et al. (2004) point 
estimate, which does not provide an estimate of the associated 
uncertainty. Lastly, it is incorrect that fixed-wings create contrails 
and helicopters do not. We have run into issues with helicopters 
causing contrails, which impede visibility while circling bears during 
capture operations in the Arctic when temperatures are <0 [deg]F.
    Comment 111: One commenter suggested that the Service overestimated 
their polar bear den detection rate for AIR surveys, which may 
underestimate take estimates resulting from den disturbance.
    Response: We rely on the best available information to obtain 
estimates of AIR efficacy to detect established dens. The mean value 
used is in line with those studies, and the associated variability 
allows detection to be as low as 1.5% in some iterations of the model.
    Comment 112: One commenter suggested that the Service overestimated 
their polar bear den detection rate for AIR surveys, which 
underestimates the number of undetected polar bear dens that may be 
potentially disturbed by Industry activities.
    Response: We disagree with this characterization of the Wilson and 
Durner (2020) estimate derived from Amstrup et al. (2004). As noted in 
the ITR, the estimate derived by Wilson and Durner (2020), i.e., ~74%, 
is only for dens available to be detected (i.e., those with snow 
shallow enough to allow AIR detection). For the current analysis, given 
that Woodruff and Wilson (2021) didn't find a relationship between 
detection and snow depth, and Smith et al. (2020) did not account for 
dens unavailable to be detected (e.g., due to snow depth), we corrected 
the Wilson and Durner (2020) estimate to be an average detection rate 
regardless of whether a den was available to be detected or not. That 
led to an estimate ~55%, with confidence intervals that overlap the 
Smith et al. (2020) estimate. Smith et al. (2020) did not provide an 
estimate of uncertainty for their mean den detection rate. But overall 
the estimates are very similar and not statistically different. The 
Wilson and Durner (2020) approach has been peer-reviewed and published 
in the peer-reviewed literature, so it constitutes the best available 
information and warrants inclusion in our analysis along with the two 
other studies that exist to estimate detection of dens using AIR.
    Comment 113: One commenter suggested that the Service clarify their 
requirements for AIR survey flight paths in order to ensure all polar 
bear denning habitat is adequately surveyed.
    Response: Our analysis is predicated on the fact that AOGA will 
survey all polar bear denning habitat that has been identified in the 
areas with proposed/current infrastructure and industrial activities. 
We make this requirement clear in our description of our analytical 
approach. Thus, AOGA will be required to ensure that all denning 
habitat is surveyed the requisite number of times to be covered under 
the ITR.
    Comment 114: One commenter suggested that the Service overestimated 
their polar bear den detection rate because they did not account for 
the depth of the dens in snow and deterioration of weather conditions 
during AIR surveys.
    Response: As occurs during Industry surveys, AIR surveys were 
paused when conditions such as wind and fog affected visibility and/or 
safety of flying. Because of the requirement for the surveys to be 
``blind,'' Woodruff and Wilson (2021) did not measure snow depth at the 
time of den surveys. This would have made tracks in the snow alerting 
AIR observers to the den location. They did not find a relationship 
between snow depth and detection and highlight that the deepest den 
(145-cm snow ceiling thickness) was detected whereas a nearby den with 
snow ceiling thickness of 66 cm was not. The authors acknowledge there 
may be other factors not accounted for in the study that are affecting 
den detection besides snow depth.

[[Page 43060]]

    Additionally, in the Woodruff and Wilson study, an attempt was made 
to reduce the influence of subsequent snowfall on their ability to 
estimate the relationship. Thus, they restricted their assessment of 
snow depth to data from the first two surveys, to minimize the effects 
of additional snowfall accumulation on the relationship with detection. 
We disagree that the study by Woodruff and Wilson suggests ``AIR 
surveys are unlikely to detect dens.'' Instead, the study shows that 
dens can be detected, but that the efficacy may not be as high as 
previously thought. Hence, they actually state ``unlikely to detect all 
dens.'' However, we take this into account in our analysis and consider 
the range of studies that have addressed AIR efficacy to derive AIR 
efficacy used in this analysis. Also see Optimal Weather Conditions for 
AIR.
    Comment 115: One commenter suggested that the Service should 
consider requesting additional AIR surveys to increase their polar bear 
den detection rate.
    Response: We rely on the best available science regarding the 
efficacy of aerial IR surveys to detect established polar bear dens. 
The Service considered multiple options for the number of AIR flights 
that would be required and found the number published in the ITR 
adequate for reducing take sufficiently while still feasible for 
Industry to conduct during the short period of the winter when AIR 
flights can be reliably done.
    Comment 116: One commenter suggested that the Service overestimated 
their polar bear den detection rate for AIR surveys based on 
comparisons to other studies.
    Response: The 74% detection estimate was only for dens with snow 
depth <100 cm. The actual probability when ignoring snow depth is 
closer to 55%. Wilson and Durner are clear how they derived these 
estimates, and they rely on standard probability methods. The commenter 
states that the appropriate metric to use from Amstrup et al. (2004) is 
the overall number of dens detected at least once, divided by the total 
number of dens surveyed. This is inappropriate, however, because it 
doesn't take into account how many times each den was surveyed. With 
increasing search effort, the probability of detecting the den 
increases. Wilson and Durner (2020) obtained an estimate for the 
probability of detecting a den on a single survey. We disagree that our 
mathematic approach ``defies logic,'' or that the approach is 
sophisticated (it's a simple binomial model) because some dens were 
detected on multiple occasions. Thus, it is inappropriate to ignore 
those detections by simply looking at the overall number of dens 
detected at least once. Wilson and Durner (2020) provide a thorough 
explanation of their approach, and it went through numerous rounds of 
peer-review during which the method was deemed appropriate and 
published in a well-respected peer-reviewed journal.
    Comment 117: Two commenters suggested that the Service should 
clarify their explanation for averaging the polar bear den detection 
rates across multiple studies considering that each study was conducted 
in a different situation that may not be applicable to the AIR surveys 
required for these regulations.
    Response: We disagree. Our approach actually tries to accommodate 
the different limitations of each of the studies. Amstrup was based on 
real dens; Woodruff was based on artificial dens. Amstrup used all of 
the tools an aircraft had to offer, but Woodruff didn't to try and 
control observer learning where dens were. Smith didn't include any 
estimate of uncertainty in their estimate of detection, nor did they 
provide much information on methods or underlying data and search 
effort. So, each study has their own set of limitations, but to our 
knowledge, these are the only data from AIR surveys. So, it represents 
the best available information. And the overall probability used wasn't 
significantly different from the results of Smith et al. (2020).
    Comment 118: One commenter suggested that the Service should 
clarify their explanation for their polar bear den detection rate and 
recommended that this detection rate is unlikely to exceed 50%.
    Response: Unfortunately, 50% is not an appropriate metric from the 
Woodruff and Wilson study because it doesn't account for search effort 
nor multiple detections of a den across surveys. Both of those factors 
need to be considered when estimating a detection probability. 
Additionally, the public was given only a brief overview of the study 
and methods because the actual study is still under journal peer 
review. Thus, the commenter doesn't have all of the caveats associated 
with that study and why it is likely inappropriate to consider only the 
results from the Woodruff and Wilson study and ignore the previously 
published works that have different study designs and pros/cons. The 
detection probability we derived and used from Amstrup et al. is also 
very similar to Smith et al. We agree with the commenter that it is 
unlikely that real-world AIR will have a detection >50%. As we showed 
in our analysis, our mean detection was 41% and could go as low as 1.5% 
during any given iteration of the model.
    Comment 119: One commenter suggested that the Service should 
specify flight paths for AIR surveys to ensure complete coverage of all 
polar bear denning habitat and require that AIR surveys conduct 
multiple passes across denning habitat as well as use helicopters for 
AIR surveys to increase den detection rates.
    Response: Because the estimates used for AIR efficacy are based on 
the range of suitable weather conditions under which AIR surveys are 
acceptable, and the analytical approach requires that all den habitat 
(as identified in the studies cited) is adequately surveyed, the ITR 
already implicitly requires these to occur.
    Comment 120: One commenter suggested that the Service should 
address how the efficacy of AIR for detecting polar bear dens with more 
than 90 cm of snow cover was accounted for in their den detection 
model.
    Response: While one study (Robinson et al. 2014) showed lower 
detectability for dens in snow deeper than 90 cm, it was based on 
handheld infrared, not aerial. And in the Woodruff and Wilson study, a 
den with snow ~145 cm deep was detected, so a simple cutoff based on 
ground-based infrared is likely not appropriate.
    Comment 121: One commenter suggested that the Service should 
consider the practicality of requesting Industry entities to complete 
three AIR surveys prior to commencing activities in polar bear denning 
habitat.
    Response: The ITR does not indicate that industry will conduct 
three AIR surveys of all habitat. Three surveys are required only for 
areas receiving seismic surveys, and in years when seismic occurs, 
along the pipeline corridor between Deadhorse and Pt. Thomson. 
Regardless, our analysis requires that all den habitat within 1 mile of 
industrial activity/infrastructure will receive at least two AIR 
surveys under conditions suitable for detecting dens. Only if industry 
flies all of the AIR surveys required per the analysis will they have 
coverage under the ITR.
    The Service notes that the extent of AIR surveys required by this 
ITR significantly exceeds what has been required under prior iterations 
of the ITR and is sufficient to ensure that all applicable MMPA 
standards are met, including the requirement to prescribe means to 
effect the least practicable adverse impact on the species or stock and 
its habitat.
    Comment 122: One commenter suggested that the Service should

[[Page 43061]]

consider whether AIR efficacy and den detection rates will be lower in 
areas adjacent to the Arctic National Wildlife Refuge because snow 
cover in these areas are greater than other areas and polar bear 
denning density is anticipated to be greater and more complex in these 
areas.
    Response: We take into account in the model the fact that some dens 
inside ANWR will go undetected because AIR surveys are not planned 
there and the area is outside of the activity area proposed by AOGA. We 
clearly stated this in the Proposed ITR document (see page 29407 of the 
FR publication). We allow dens to be simulated in the refuge, even 
though activity does not occur there as part of this Request. But they 
were put there because they could be disturbed by activities in the 
petition area and go undetected by AIR. Any den within a mile of 
activity proposed in the ITR, but that occurred inside the refuge, was 
accounted for in our estimates of take. Because we account for these 
dens but assume that no AIR surveys will take place, differences in 
habitat conditions that could affect AIR detection rates are not 
relevant.
    Comment 123: One commenter suggested that the Service continue to 
evaluate and refine their polar bear denning model assumptions used to 
determine take estimates for their regulations as more data become 
available.
    Response: The Service has used a comprehensive dataset of polar 
bear observations to develop estimates of Level B harassment, and will 
continue to refine these methods and our database for future ITRs. 
Comparing denning model results to historic Industry-polar bear 
encounter records is not possible because a systematic effort has never 
been undertaken by Industry to find all dens adjacent to existing 
infrastructure, not just ice roads and tundra travel routes as is the 
current requirement under the existing ITR. Additionally, even when a 
den is found, monitoring has not occurred systematically (or 
frequently) to look at dates of den emergence and departure. Further, 
given that the effects of early emergence can lead to lower cub 
survival, there is no way for Industry to document all cub mortality 
events that are associated with den disturbance as this would require 
constantly monitoring a family group until at least 100 days post 
emergence (as Rode et al. 2018 did).
    Comment 124: One commenter suggested that the polar bear den case 
studies used to determine responses to den disturbance do not 
accurately represent the polar bear responses expected during Industry 
activities because these case studies were collected during scientific 
studies in which polar bears were captured and collared.
    Response: The goal of the case study analysis was to inform the 
consequences of den disturbance due to industrial activities. Including 
incidents spanning a range of activities (i.e., Industry and research-
related) was reasonable as there are correlations between disturbance 
caused by research and that caused by Industry, such as inadvertently 
approaching a den at close distance. Additionally, the premise of some 
research was to evaluate the response of denning bears to remediation 
activities. Capture events likely are more intrusive than any 
disturbance related to industrial or other human activities and were 
not used in the calculation of take probabilities. Bear responses to 
capture events can, however, help inform our understanding of how polar 
bears respond to any type of disturbance. Other activities, such as 
disturbance caused by people approaching dens or accidental intrusion, 
are also possible when a den's location is unknown. Consequently, 
exposures by researchers are useful in understanding how bears respond 
to disturbance and allowed us to better estimate the response 
probabilities that informed the simulation model.
    Comment 125: One commenter suggested that the Service's use of the 
upper 99 percent quantile of each probability distribution is too 
conservative to determine polar bear responses to disturbance and does 
not accurately reflect observer bias and the number of unobserved takes 
and this approach results in overestimation of polar bear incidental 
take.
    Response: We disagree. The Service did not use the 99-percent 
quantiles to account for perceived directional bias by observers (which 
can neither be confirmed nor denied due to lack of neutral third party 
observational data), instead, the Service used the 99-percent quantiles 
to encompass the number of potential Level B harassment events as 
directed by the MMPA.
    Comment 126: One commenter suggested that the Service overestimated 
the take of polar bears during aircraft activities by assuming a lower 
flight altitude than is typically flown by Industry aircraft as part of 
their take determination analyses.
    Response: When reviewing the dataset from coastal polar bear 
surveys, the Service found there was not enough data to identify a 
significant relationship between polar bear response and distance to 
the aircraft. The Service applied a constant harassment rate to all 
flights listed as being flown at 1,500 ft AGL or lower. Many flights 
were listed with a minimum altitude of 1,500 ft AGL, which would be 
within the scope of the analysis. Flights that are expected to be above 
1,500 ft (generally originating from outside of the ITR region) were 
described as remaining at this altitude until descent. Without more 
information on each individual flight's altitude, point of descent, and 
the present weather conditions, we made the assumption that an aircraft 
could descend to 1,500 ft AGL or less anywhere within the ITR region.
    Comment 127: One commenter suggested that the Service overestimated 
the number of polar bears observed by vessels during in-water 
activities and this approach resulted in an overestimation of polar 
bear encounter rates and take estimates during offshore activities.
    Response: There is no data to indicate the number of bears present 
in the water at any given time; however, we do have data for the number 
of bears located along the coast, which was used in the analyses. These 
bears frequently swim between barrier islands and may be impacted by 
these offshore activities.
    Comment 128: One commenter suggested that the Service should 
reconsider whether the addition of new Industry facilities and 
infrastructure will correlate with an increase in incidental harassment 
of polar bears.
    Response: We disagree. While AOGA has drawn this conclusion in 
their Request, the relationship described by the Service between 
distance to shore and polar bear encounters indicates that an increase 
in coastal infrastructure will increase the number of encounters and 
subsequent harassment events. This issue was described at length within 
the proposed rule.
    Comment 129: One commenter suggested that the Service should 
clarify how they accounted for the uncertainty of non-responses of 
polar bears to disturbance and whether the likely underrepresentation 
of non-responses may lead to overestimation of take by Level A 
harassment.
    Response: The case study analysis included all well-documented 
records of human activity that occurred within 1.6 km of active polar 
bear dens. We do not believe that exposures that elicited detrimental 
responses were more likely to be documented than those that seemingly 
did not. Consequently, the probabilities of exposures resulting in 
lethal take or Level A harassment are unlikely to be biased. Further, 
cases that

[[Page 43062]]

did not result in an observed detrimental response (i.e., `non-
responses' in the comment) do not necessarily indicate that the animals 
were unaffected (Frid and Dill 2002, Bejder et al. 2006, Laske et al. 
2011); hence, our classification of `likely physiological response.' 
Arousals during denning can lead to some increases in body temperature 
(Craighead et al. 1976, Laske et al. 2011, Evans et al. 2016b) and 
heart rate (Reynolds et al. 1986, Evans et al. 2016b), both of which 
require use of valuable energy reserves. Across taxa, unobserved 
effects, including higher levels of stress hormones (Moberg 2000, Keay 
et al. 2006) and others have been shown to have the potential to be 
equally as consequential for reproduction (Carney and Sydeman 1999, 
Ellenberg et al. 2006, Rode et al. 2018b). Decreased reproductive 
success or reproductive failure in bears is documented as a consequence 
of denning disturbance (Ramsay and Dunbrack 1986, Amstrup and Gardner 
1994, Linnell et al. 2000, Swenson et al. 1997).
    Comment 130: One commenter suggested that the Service should 
consider additional factors that may cause a polar bear to emerge early 
from her den without necessarily resulting in reduced cub production 
and survival, which are referenced in the Rode et al. (2018) study.
    Response: We agree with the commenter that there are other 
hypotheses that may explain the results of Rode et al. (2018), as we 
acknowledge in the proposed ITR (p. 29393). However, Rode et al. (2018) 
does indicate that the most likely explanation for their results is the 
earlier emergence leading to survival consequences for cubs. This makes 
sense given the altricial nature of cubs when born and the time bears 
spend at the den site after emergence to allow cubs time to grow more 
and become acclimated to the outside environment. We do attempt to take 
into account some of the other causes of emerging from a den without 
cubs. We allow an average of 7% of simulated dens to emerge without any 
cubs, so we do account for some females naturally emerging without any 
offspring, which are not attributed to any form of disturbance from 
industrial activity. We disagree, however, that because there are other 
potential hypotheses for the relationship presented in Rode et al. 
(2018) that we have to ignore the relationship she published. As it 
currently stands, we don't have any additional data to suggest that the 
relationship documented in Rode et al. (2018) isn't accurate as 
portrayed. However, if additional information is published in the 
future, that would be considered the best scientific information 
available and we would use it accordingly.
    Comment 131: One commenter suggested that the Service should 
consider whether the variability of mobile activities will affect 
occupancy rates used to determine take estimates and whether take 
estimates are overestimated from a conservative occupancy rate.
    Response: Occupancy rates for all of the different infrastructure 
was provided by AOGA as part of their Request.
    Comment 132: One commenter suggested that the Service should 
estimate take for Level A and Level B harassment zones for in-water 
activities.
    Response: The Service has revised Table 1 to include details 
regarding the sound measurement units and included peak SPL for 
impulsive sound sources. The Service has also revised references to 
past ITR Level B harassment and TTS thresholds. With regards to the 
need for Level A harassment zones, the Service did not calculate this 
area as no sound sources identified in the proposed activities would 
produce Level A threshold noise. As was stated in the proposed rule, 
the Level B harassment zone was smaller than the impact area of surface 
activities, so we estimated take using the more conservative impact 
area.
    Comment 133: One commenter suggested that the Service should 
consider whether the number of takes during aircraft overflights is 
underestimated considering the increased use of helicopters compared to 
previous years and the higher polar bear response rate to helicopters.
    Response: Any flight paths associated with major construction 
activities have been incorporated into the aircraft analysis. AOGA 
provided the Service with a list of aircraft that would likely be used 
for each activity--an increase in helicopter use is speculative. While 
the harassment rates were calculated using data from AeroCommander 
flights, the Service discusses results from observational flights using 
helicopters. The harassment rates associated with these helicopter 
flights were found to be lower than the rates used in the AOGA Request. 
No significant relationship between polar bear response and distance to 
aircraft was concluded from the dataset. We are working to further 
refine our take rates associated with these analyses; however, more 
data is needed before we can differentiate take rates based on the type 
of aircraft. More detailed information on behavioral responses from 
these overflights can be found in the ITR section Aircraft Impacts to 
Surface Bears.
    Comment 134: A recent peer-reviewed article, ``Polar bear 
behavioral response to vessel surveys in northeastern Chukchi Sea, 
2008-2014'' by Lomac-MacNair et al. (2021), should be incorporated into 
the Service's analysis of behavioral responses of polar bears to vessel 
activity as information in the publication could be used to improve the 
in-water analysis and could also supplement and support established 
mitigation measures, such as set-back distances for polar bears, as 
well.
    Response: We agree Lomac-MacNair et al. 2021 is a valuable addition 
to the body of polar bear disturbance literature. However, the paper 
published after the proposed rule was published for public comment. We 
have reviewed the publication, and the authors' findings are consistent 
with the current impact areas used in the proposed and final rules.
    Comment 135: The Service's discussion of the peer-reviewed article 
``Aquatic behaviour of polar bears (Ursus maritimus) in an increasingly 
ice-free Arctic.'' Lone, et al. 2018, appears to misstate or overstate 
conclusions contained in that article.
    Response: The Service has clarified our discussion regarding the 
conclusions we draw from this article as needed.
    Comment 136: The Service should supplant the Southall et al. (2019) 
modeled and extrapolated approach by gathering hearing data (i.e., TTS 
and PTS) specific to polar bears, rather than relying solely on 
information attributed to ``other marine carnivores,'' and use polar 
bear-specific acoustic information for future analyses.
    Response: We agree that our analysis could be improved with 
species-specific information for polar bear responses to sound. We also 
recognize that such efforts may be challenging to obtain on polar bears 
in the wild or held in captivity. However, we will continue to improve 
our understanding of polar bear hearing acuity as feasible.
    Comment 137: The Service should supplant the Southall et al. (2019) 
modeled and extrapolated approach by gathering hearing data (i.e., TTS 
and PTS) specific to walruses, rather than relying solely on 
information attributed to ``other marine carnivores,'' and use walrus-
specific acoustic information for future analyses.
    Response: As noted above, we agree that our analysis could be 
improved with species-specific information for Pacific walrus responses 
to sound. We also recognize that such efforts may be

[[Page 43063]]

challenging to obtain on Pacific walrus in the wild or held in 
captivity. However, we will continue to improve our understanding of 
Pacific walrus hearing acuity as feasible.
    Comment 138: The Service should consider the report ``Simulation of 
Oil Spill Trajectories During the Broken Ice Period in the Chukchi and 
Beaufort Seas'' (French-McCay et al. 2016) to better inform our 
analysis of potential polar bear oil spill exposure and effects in the 
Beaufort Sea.
    Response: We have used BOEM's 2020 Oil Spill Risk Assessment 
because it provides the most current and rigorous treatment of 
potential oil spills in the Beaufort Sea Planning Area. We agree 
analysis similar to Wilson et al. 2018 would be a valuable addition to 
future regulations.
NEPA and ESA
    Comment 139: One commenter suggested that the Service's EA is 
inadequate because it does not present a reasoned explanation for the 
determinations of polar bear take and requests the Service to prepare 
an EIS.
    Response: We disagree. The Service's EA and FONSI reasonably 
reflect considerations important to SBS polar bears and Pacific walrus, 
and are scientifically and legally adequate. It is appropriate for the 
EA to reference and summarize the ITR's analysis and determinations 
rather than duplicate them in their entirety.
    Comment 140: One commenter suggested that the Service did not 
consider restricting the geographic scope and timing of activities as 
an alternative to reduce impacts in their EA.
    Response: We disagree. Temporal and geographic constraints were 
incorporated into AOGA's revised request in light of collaboration with 
the Service. The Service also considered the use of further time and 
space restrictions for oil and gas activities to limit the impact on 
denning bears. These restrictions were not determined to be practicable 
as they may interfere with human health and safety as well as the 
continuity of oil and gas operations. The Service found that no 
additional mitigation measures are required to be imposed through the 
ITR, other than those described, in order to effect the lease 
practicable adverse impact on polar bears and walruses.
    Comment 141: One commenter suggested that the Service should 
reevaluate the EA's no action alternative to account for baseline 
conditions in which the commenter suggests that this alternative will 
result in a curtailment of activities as opposed to activities 
proceeding without requested mitigation measures and potentially 
unauthorized take.
    Response: The EA's characterization of the No Action Alternative is 
appropriate and meets all NEPA requirements. Oil and gas exploration, 
development, and production activities have occurred at various 
locations on the North Slope and adjacent Beaufort Sea waters for 
several decades and will continue to occur in the future, with or 
without this ITR. Hence, they are necessarily recognized as part of the 
environmental baseline. The notion that denying AOGA's Request for this 
ITR would cause the specified oil and gas activities to cease or not 
occur has no basis in law or practical reality. Operators may proceed 
without an incidental take authorization (albeit at the risk of 
enforcement actions), modify their activities in a manner that avoids 
incidental take, and/or obtain other forms of incidental take 
authorization (i.e., IHAs or a different ITR).
    Comment 142: One commenter suggested that the Service does not 
adequately discuss the effectiveness of the requested mitigation 
measures in the EA.
    Response: The ``mitigation measures'' integrated into the ITR are 
already incorporated into the proposed action analyzed in the EA. The 
case cited by the commenter appears to address the manner in which an 
action agency must evaluate additional mitigation measures that are not 
already incorporated into the proposed action, and thus seems off-
point. The EA's references to ``spatial and temporal restrictions'' 
encompass limitations inherent to AOGA's specified activities, e.g., 
finite project footprints, the seasonal rather than year-round nature 
of certain activities, buffer zones, etc. These limitations are 
described in detail in AOGA's Request, the ITR, and Section 2.3.1 of 
the EA. The EA need not comprehensively re-list each limitation in the 
Summary sections quoted by the commenter.
    Comment 143: One commenter suggested that the Service should 
account for the potential of take by Level A harassment and discuss the 
associated impacts on SBS polar bears in the EA.
    Response: The Service does not ignore the potential for lethal 
injurious take to occur. Rather, it quantitatively estimated the 
probability of such impacts occurring. The commenter acknowledges as 
much when it references the Service's own estimate. The Service does 
not assume that no ``take by Level A harassment'' will occur; rather, 
it does not anticipate that any take beyond take by Level B harassment 
will occur. The Service disagrees with the commenter's broad and 
unsupported assertion that it greatly underestimated ``take by Level A 
harassment.'' The Service analyzed all potential impacts using a 
rigorous methodology and the best available scientific evidence.
    Comment 144: One commenter suggested that the Service should 
account for additional impacts, such as planned development and 
increased emissions from future activities, when determining what level 
of take is permitted in order to be considered a negligible impact.
    Response: The MMPA directs the authorization of incidental take 
where the requestor's specified activities meet specific MMPA standard 
(e.g., small numbers, negligible impact, no unmitigable adverse impact 
on the availability of the stock for subsistence purposes). Here, the 
Service has reasonably determined that the incidental take associated 
with the specific activities described in AOGA's Request adhere to 
applicable MMPA standards. The possibility that other activities (e.g., 
hypothetical activities at ANWR, Liberty, or greenhouse gas emission 
sources around the world) could independently impact the SBS stock of 
polar bears sometime in the future does not preclude the issuance of 
this ITR.
    Comment 145: One commenter suggested that the Service should 
conduct a more thorough site-specific analysis of impacts to polar 
bears and their ESA-designated critical habitat.
    Response: We disagree. As explained in the proposed rule, and 
affirmed in this final rule, the Service conducted a robust analysis of 
potential impacts to polar bears and their habitat under this 
rulemaking. Further, and as we acknowledged in the proposed rule, the 
Service recognized that the proposed regulation could impact polar 
bears and their ESA-designated critical habitat. Therefore, prior to 
finalizing this regulation, the Service conducted an intra-Service ESA 
section 7 consultation on our proposed regulation. The ESA section 7 
biological opinion and its determinations issued prior to finalizing 
these regulations is available as a supporting document in the 
www.regulations.gov docket as well as on the web at: https://ecos.fws.gov/ecp/report/biological-opinion.
    Comment 146: One commenter suggested that the Service should 
include an environmental impact statement as part of their 
authorization.
    Response: We disagree. As explained in the proposed rule, and 
affirmed in this final rule, the Service fully

[[Page 43064]]

complied with our NEPA responsibilities and determined that the 
preparation of an EIS was not required for these regulations. 
Additionally, the Service notes that the polar bear is considered 
threatened, not endangered, under the ESA. The Service likewise fully 
complied with the consultation requirements under section 7 of the ESA, 
finalizing this regulation only after receipt of required 
determinations under that consultation.
    Comment 147: One commenter suggested that the Service should 
broaden the purpose and need specified in the EA in order to consider 
additional alternatives for their environmental analysis.
    Response: The Service's statement of purpose and need is 
appropriate and not impermissibly narrow. Further explanation of the 
Service's efforts to identify other reasonable alternatives is provided 
in the final EA. The Service's summaries of (1) its early coordination 
with AOGA, which resulted in AOGA revising its Request in a manner that 
further limited the scope of its specified activities, and (2) its 
analysis conducted under the MMPA's least practicable adverse impacts 
standard further established that the Service complies with the letter 
and spirit of NEPA's requirement to analyze all reasonable 
alternatives.
    Comment 148: One commenter suggested that the Service should 
clarify the EA's purpose and need to ensure that these statements are 
consistent with the Service's requirements under the MMPA and these 
statements are separate from the applicant's interests.
    Response: The Service's EA reflects the fact that the agency's 
interest is distinct from the applicant's. The Service's interest is in 
fulfilling its obligations under the MMPA and taking a hard look at its 
proposed action under NEPA. The Service will render its decision based 
on the relevant statutory and regulatory authorities whether or not 
that decision is in the applicant's interest.
    Comment 149: One commenter suggested that the Service should revise 
the purpose and need statements in the EA to clarify that the 
environmental impact analysis was conducted to limit impacts of 
Industry activities on polar bears and walruses rather than supporting 
the ITR determinations for authorization.
    Response: The Service did not ``predetermine'' anything in this 
process. The Service's EA analyzes the potential impacts of a proposed 
action, i.e., issuing an ITR, and not a decision that was already made. 
Were the Service (on the basis of its own initial review or additional 
information submitted via public comment) to find itself unable to make 
the requisite determinations under the MMPA, it would not issue a final 
ITR. While this much is clear from the larger context of the proposed 
ITR and draft EA, the Service has revised the final EA so as to review 
any reasonable implication to the contrary.
    Comment 150: One commenter suggested that the Service should 
consider as alternatives in their EA additional mitigation measures 
that include restricting Industry activities during the polar bear 
denning season, implementing a buffer around denning habitat, and only 
authorizing Industry activities that are compliant with the Nation's 
climate goals to limit global warming.
    Response: The Service has worked with the applicant to identify 
areas of high denning density and incorporate later start dates for 
seismic activity in this region. We also worked with the applicant to 
develop ideal temporal windows for maternal denning surveys.
    While further restrictions of operations during winter and 
implementation of a buffer around all potential denning habitat are not 
practicable given the location of existing facilities and roads that 
must be utilized during winter to ensure the continuity of operations 
and protection of tundra and wetlands, the ITR contemplates a suite of 
mitigation measures to protect denning bears (i.e., avoidance measures, 
multiple AIR surveys, exclusion zones around known or putative dens). 
Since the Service does not have authority to approve or disapprove the 
oil and gas activities themselves, it cannot pick and choose which 
activities may continue in order to meet climate goals.
    Comment 151: One commenter suggested that the Service should 
clarify how the physical environment will be impacted by Industry 
activities in the EA.
    Response: The commenter appears to unduly conflate potential 
impacts from the proposed action--i.e., issuing an ITR--with potential 
impacts from the underlying oil and gas activities, which the Service 
does not authorize and which are not an effect of the action. In 
developing the EA, the Service considered whether issuing the ITR and 
authorizing the incidental take contemplated therein would cause any 
reasonably foreseeable impacts to the physical environment, and 
reasonably determined that it would not. None of the on-the-ground 
activities cited in the comment would be approved by the Service or 
caused by the ITR.
    Comment 152: One commenter suggested that the Service should 
address how additional oil and gas activities will impact the climate 
as part of the EA.
    Response: The scope of the EA is to describe impacts from the 
Federal action of issuing the ITR. Effects of the oil and gas 
activities themselves, to include upstream and downstream GHG 
emissions, are not effects of the Service's Proposed Action.
Mitigation Measures
    Comment 153: One commenter suggested that the Service should 
include mitigation measures that restrict Industry activities.
    Response: While reviewing prior iterations of AOGA's Request, the 
Service discussed the appropriateness of further limiting the scope of 
AOGA's specified activities so as to reduce the potential taking of 
polar bears. AOGA subsequently made several revisions to its Request, 
which the Service accounted for in its analyses under the MMPA and 
NEPA. The Service also attempted to identify further operational 
restrictions in satisfaction of the MMPA's least practicable adverse 
impacts standard and NEPA's requirement to analyze reasonable 
alternatives and mitigation measures. The results of those efforts are 
described in the various analyses supporting the ITR process.
    Comment 154: One commenter suggested that the Service should 
address the inconsistency in the number of required AIR surveys in the 
EA and ITR.
    Response: We will provide further clarification in the EA on the 
number of AIR flights required for each activity.
    Comment 155: One commenter suggested that the Service should revise 
the mitigation measure at proposed Sec.  18.126(d)(2) to include ``safe 
and operationally possible'' in regards to maintaining the minimum 
aircraft flight altitude.
    Response: We have made this revision.
    Comment 156: One commenter suggested that the Service should revise 
the mitigation measure at Sec.  18.126(4)(c)(1) to include that vessel 
crew members may also qualify as dedicated marine mammal observers in 
order to accommodate vessels with limited crew capacity.
    Response: The Service recognizes the limited crew member capacity 
aboard certain vessels and that it may not always be possible to take 
on an additional crew member to conduct watches for marine mammals. 
Requirements for marine mammal observers will be evaluated upon 
submission of applications for LOAs.

[[Page 43065]]

    Comment 157: One commenter suggested that the Service should 
consider additional infrared technology alternatives in addition to AIR 
in order to increase the detectability of polar bear dens.
    Response: AIR efficacy rates used in our estimates for take of 
denning bears were based upon surveys using both helicopters and fixed 
wing aircraft. AOGA proposed using only fixed wing aircraft for IR so 
that is what the Service analyzed. While visual observations and on-
the-ground surveys are commonly implemented mitigation measures in 
addition to AIR surveys, we currently lack the data needed to analyze 
the den detection efficacy rates of visual and handheld infrared 
methods.
    Comment 158: One commenter suggested that the Service should 
clarify the required mitigation measures regarding offshore seismic 
surveys.
    Response: No offshore seismic operations were included in the 
proposed activities, thus take will not be authorized for offshore 
seismic projects in this rule. As such the Service did not need to 
include mitigation measures such as ramp-up and shutdown procedures.
    Comment 159: One commenter suggested that the Service should 
clarify whether the requirement for Industry entities to cooperate with 
the Service and participate in joint research efforts to assess 
Industry impacts on marine mammals was removed.
    Response: This language was erroneously omitted. We have revised 
the final rule to include this language.
    Comment 160: One commenter suggested that the Service should 
clarify whether human--polar bear encounters that occur during this 
regulation period will be submitted to the Polar Bear--Human 
Information Management System (PBHIMS) in order to contribute to 
international efforts for polar bear conservation.
    Response: The Service represents the United States as a participant 
in the Polar Bear Range States. We will continue to submit applicable 
human--polar bear encounter records to PBHIMS as part of our 
participation in this effort.
    Comment 161: One commenter suggested that the Service should 
request stricter mitigation measures for minimum aircraft flight 
altitudes and maximum vessel speeds to reduce potential impacts on 
marine mammals.
    Response: The Service has worked with the applicant to develop 
mitigation measures that create the least practicable adverse impact on 
polar bears and Pacific walruses. The ITR requires aircraft to fly high 
enough, and vessels to travel slow enough, to greatly reduce the 
potential for impacts. Further restrictions were deemed unnecessary to 
achieve the least practicable adverse impact because they were 
precluded either by safety considerations or they would not discernably 
reduce the potential for effects to marine mammals.
    Comment 162: Commenters suggested that the Service should request 
more specific mitigation measures to reduce impacts on marine mammals 
during project activities.
    Response: The ITR already prescribed the means of effecting the 
least practicable adverse impact on Pacific walruses and SBS polar 
bears. Further, the Service retains discretion to impose additional 
mitigation measures on an activity-specific basis through the LOA 
process.
    Comment 163: One commenter suggested that the Service should 
address how the requested mitigation measures reduce Industry impacts 
on polar bear and walrus and their habitat.
    Response: The Service has worked with the applicant to identify 
areas of high denning density and incorporate later start dates for 
seismic activity in this region. We also worked with the applicant to 
develop ideal temporal windows for maternal denning surveys. These 
mitigation measures have been designed to impart the least practicable 
adverse impact from the proposed activities on polar bears.
    Comment 164: One commenter suggested that the Service should 
evaluate the effectiveness of monitoring by protected species observers 
(PSOs) to detect marine mammals during periods of restricted 
visibility.
    Response: While we acknowledge some weather conditions may hinder 
their ability to identify animals, the Service believes that PSOs 
contribute information important to the safety of humans, polar bears, 
and Pacific walruses.
    Comment 165: One commenter suggested that the Service should revise 
language in the mitigation measures to be more specific about Industry 
activity restrictions in order to reduce impacts on marine mammals.
    Response: There is an iterative process of communication between 
the Service and applicants when applying for individual LOAs and upon 
the receipt of results from maternal den surveys. The Service is 
unaware of the exact location dens may be occurring each year and is 
unable to make specific regulations based on these locations.
    Comment 166: One commenter suggested that the Service should 
consider all habitat characterized by a 1-meter elevation difference 
and a slope of eight degrees or greater as suitable polar bear denning 
habitat that should be avoided by Industry activities.
    Response: The applicant is required to consult the USGS map of 
potential denning habitat prior to activities. Mitigation measures 
outlined by the ITR must also be implemented to reduce disturbance to 
unknown dens.
    Comment 167: One commenter suggested that the Service should 
request that all Industry entities should hire PSOs to monitor Industry 
impacts on marine mammals.
    Response: Hiring of separate PSOs is not always practicable for the 
applicant's proposed activities. The Service has included training, 
monitoring, and reporting requirements in the rule.
    Comment 168: One commenter suggested that the Service should 
consider designating certain areas that are important to marine mammals 
as off-limits to Industry activities.
    Response: We appreciate the recommendation and will continue to 
research and incorporate innovative measures for achieving the least 
practicable impact in future ITRs.
    Comment 169: One commenter suggested that the Service should 
request a 1-mile buffer around all suitable polar bear denning habitat 
in order to prevent Industry activities disturbing undetected polar 
bear dens and reduce impacts to denning polar bears.
    Response: Proper denning habitat requires the creation of snow 
drifts, which can differ from year-to-year as it is based on terrain 
and weather conditions. The ability to identify areas in which these 
snow drifts may occur each year prior to operations is not practicable.
    Comment 170: One commenter suggested that the Service should 
analyze the results of polar bear den monitoring AIR surveys and human-
polar bear encounters reported during this regulation period in a 
timely manner in order to better evaluate the effectiveness of the 
requested mitigation measures.
    Response: We appreciate the recommendation.
    Comment 171: One commenter suggested that the Service should 
request that Industry activities be shut down if an injured or dead 
walrus or polar bear is reported and activities not resume until the 
Service investigates the circumstances that caused the injury or death 
of the walrus or polar bear.
    Response: The Service has included in the rule a reporting 
requirement upon the injury or death of a walrus of polar bear as soon 
as possible but within 48 hours. While it may aid in any

[[Page 43066]]

subsequent investigation, ceasing activities in an active oil field may 
not be practicable or safe in certain circumstances, and thus will not 
be mandated.
    Comment 172: One commenter suggested that the Service should 
clarify their definition for a concentration or group of walruses or 
polar bears, and the commenter recommended this definition be two or 
more individuals.
    Response: We have added this revision.
    Comment 173: Paragraph 4 under ``Mitigation measures for 
operational and support vessels'' notes the 1 July date to allow oil 
and gas vessels to enter the Beaufort Sea, which is based on past 
information that could become less relevant and accurate in the future. 
We recommend the Service consider other metrics to meet the intention 
of this measure. A more flexible approach, for example, would be to 
restrict entry into the Beaufort Sea until a sufficient percentage of 
shorefast ice has melted.
    Response: We have considered this request and recognize that in the 
future changing sea ice conditions, especially if the impacts of 
climate change are not ameliorated, may reflect a different metric. 
However, and because these regulations are issued for a period of 5 
years only, at this time we believe the July 1 date best reflects our 
current understanding of sea ice changes. We also have determined that 
providing this date will provide better certainty to the regulated 
public for planning purposes.
    Comment 174: One commenter suggested that the Service should 
account for polar bears becoming habituated to Industry activities to 
avoid overestimating take.
    Response: We are not aware of any studies that have shown that 
bears become habituated to humans after denning in industrial areas or 
that this type of habituation leads to reduced disturbance. If the 
information existed, we would have incorporated it into the model. 
Harassment rate calculations incorporated the Service's polar bear 
sighting database, which contains all reports of Industry sightings of 
walrus and polar bears (as directed by the Service of all LOA holders). 
Assuming the practices of training, monitoring, and adaptive measures 
have previously been implemented, the sightings data would have 
somewhat incorporated their implementation. However, at this time there 
is no way to explicitly incorporate this data into the analysis.
    Comment 175: One commenter suggested that the Service should 
account for the effectiveness of mitigation measures in their take 
estimations in order to avoid overestimating the number of incidental 
takes of polar bears during Industry activities.
    Response: We agree that mitigation measures are important for 
reducing disturbance to polar bears, and we currently require each 
applicant to have a polar bear interaction plan and to have taken 
approved polar bear deterrence training. However, it is unclear how to 
integrate the measures into our quantitative modeling approach. The 
implementation of these mitigation measures is key to ensuring the 
least practicable adverse impact on polar bears and Pacific walrus as 
directed by the MMPA.
Policy and Procedure
    Comment 176: This proposed ITR appears to include new information 
requirements from applicants seeking LOAs. New items include: (1) A 
digital geospatial file of the project footprint, (2) estimates of 
monthly human occupancy of the project area, and (3) dates of AIR 
surveys if such surveys are required. However, the text in the actual 
proposed rule, i.e., Sec. Sec.  18.122-18.123, does not clearly 
indicate a requirement for these items. We recommend that this 
requirement be clarified in the final rule. Similarly, the preamble of 
the proposed rule introduces a new concept of ``monthly human 
occupancy''; however, this new concept as written may be confusing, and 
we similarly recommend that it be better described in the final rule to 
ensure applicants can provide the requested information.
    Response: We have revised this final rule to clarify information 
requirements from applicants for LOAs and have clarified our discussion 
regarding monthly human occupancy.
    Comment 177: Section 18.126(b)(4) of the proposed regulation states 
that applicants will restrict timing of the activity to limit 
disturbance around dens. We recommend clarifying whether this will 
apply to an unoccupied den, putative dens, or verified occupied dens 
only and describing what types of timing restrictions can be expected.
    Response: We agree and have added clarifying language to Sec.  
18.126(b)(4) of this final rule.
    Comment 178: The term ``other substantially similar'' activities is 
used in the title of subpart J of the proposed rule as well as in 
Sec. Sec.  18.119, 18.121, 18.122, and 18.124. This term follows the 
description of the activities from which take may occur but is not 
found in the preamble text. We recommend the Service provide examples 
of these activities in the proposed rule or define this term in the 
preamble to add clarity.
    Response: We agree and have revised this final rule to provide 
clarity.
    Comment 179: The proposed ITR incorrectly reflects the numbers of 
leases and land area covered by those leases in the NPR-A.
    Response: We agree. This final rule has been revised to reflect 307 
leases covering 2.6 million acres.
    Comment 180: In regard to compliance with international 
conservation agreements, one commenter suggested that the Service 
should consider transboundary impacts on polar bears under 
international polar bear conservation agreements.
    Response: While we acknowledge polar bears in the Southern Beaufort 
Sea move between the United States and Canada, our analysis determined 
that authorizing the Level B harassment of a small number of polar 
bears in the Beaufort ITR region will not have any transboundary 
impacts, much less impacts that violate international obligations. The 
Service has also reasonably determined that these Level B harassments 
will not have any unmitigable adverse impacts on the availability of 
SBS polar bears for subsistence uses. Additionally, while we 
acknowledge the important management provisions accomplished under the 
1988 Inuvialuit-Inupiat Polar Bear Management Agreement, we note that 
this is a voluntary agreement and therefore not binding on the U.S. 
Government.
    Comment 181: One commenter suggested that the Service should 
evaluate activity impacts for a larger geographic region that extends 
beyond areas of Industry activity.
    Response: The Service has conducted a thorough and robust analysis 
using the best available science to calculate the number of incidental 
harassments of polar bears and walrus due to Industry activities within 
the specified geographical region. The ITR refers specifically to ``the 
area of Industry activity'' as it is the source of the impact, which is 
not uniformly distributed across the specified geographical region. The 
Service is unable to calculate take from Industry activities in areas 
where Industry activities do not occur within the specified 
geographical region. While the range of a species may be larger than 
the specified activity area, the distribution is rarely (if ever) 
uniform within that space, especially in migratory species. Small 
numbers determinations are based on the number of individual bears 
exhibiting a Level B response and the appropriate stock population 
estimate.
    Comment 182: One commenter suggested that the Service did not

[[Page 43067]]

provide the allotted time for the public comment period that is 
specified in the MMPA, APA, and NEPA regulations.
    Response: The Service provided the public with a sufficient 
opportunity to comment on the proposed ITR and draft EA. The numerous, 
in-depth public comments that the Service received on the proposed ITR 
modeling analysis appear to corroborate the Service's judgment on this 
issue. ITRs establish important mitigation measures and provide 
significant conservation benefits to polar bears, and it is important 
that the Service finish its process and render a decision in a timely 
manner.
    We also note that the commenter has in fact had access to the 
referenced 57 case studies--which were provided as part of the 
administrative record in the Willow litigation in which they are a 
plaintiff--for several months. These studies have also been in the 
Service's Freedom of Information Act reading room for the duration of 
the proposed ITR comment period. With respect to the Woodruff and 
Wilson study, the Service gained access to a draft manuscript and 
preliminary results during the later stages of development of the 
proposed ITR and thought it was important to include this information 
as part of the best available scientific evidence. Although we expected 
a final manuscript would be available for public release prior to 
publication of the proposed ITR, this did not occur. In the interest of 
providing information for public review, the Service then developed its 
own summary of relevant findings and uploaded that summary to the 
docket as soon as it could. The Service adjusted the assumed AIR 
efficacy rate utilized in the ITR process based on this new 
information. Because the results of this study suggest an efficacy rate 
lower than that previously assumed, the Service's integration of this 
information resulted in a slight downward refinement of the assumed AIR 
efficacy rate.
    Comment 183: One commenter suggested that the Service should 
include a list of entities conducting activities under this 
authorization and a description with the accompanying analysis of 
expected impacts from these Industry activities in the authorization.
    Response: No entities may conduct activities under coverage of this 
ITR until they receive an LOA from the Service. The ITR provides 
sufficient description of the specified activities and those entities 
that qualify for LOAs.
    Comment 184: One commenter suggested that the Service should 
include a list of specific oil and gas activities that the Service 
evaluated and that would be authorized under LOAs issued under these 
regulations.
    Response: The description of specified activities provided in the 
ITR is sufficiently detailed. Additional information is available in 
AOGA's request.
    Comment 185: One commenter suggested that the Service should revise 
their language to exclude listing specific subsistence communities or 
organizations that may be consulted during a Plan of Cooperation and 
add a general requirement in order to avoid potentially excluding other 
communities or organizations.
    Response: Comment noted.
    Comment 186: One commenter suggested that the Service should 
complete government-to-government consultations with Alaska Native 
communities to ensure that the Service mitigates the impacts on 
subsistence use of marine mammals prior to finalizing this ITR.
    Response: The Service has determined that issuing this ITR would 
not cause any potential effects that trigger the obligation to engage 
in government-to-government consultation or government-to-ANCSA (Alaska 
Native Claims Settlement Act) corporation consultation. The effects of 
the Service's action is limited; it only authorizes the Level B 
harassment of small numbers of polar bears. Any resulting effects to 
individual polar bears would be inherently limited and short-term and, 
as explained in more detail elsewhere, would not cause more than a 
negligible impact to the SBS stock of polar bears and or any 
unmitigable adverse impacts on the availability of SBS polar bears for 
subsistence uses. As such, the Service has determined that promulgating 
this ITR will not have any substantial direct effects on any federally 
recognized Tribes or ANCSA corporations.
    That said, in the interest of cooperation and ensuring that the 
views and concerns of Alaska Native communities are heard and 
considered in its decision-making process, the Service sent 
notification of its proposed action to promulgate the ITR to federally 
recognized tribes and ANCSA corporations with interests in the Beaufort 
ITR area and surrounding areas on May 27, 2021. The Service did not 
receive any replies indicating interest in government-to-government 
consultation or government-to-ANCSA corporation consultation. The 
Service remains open to consulting with these parties at any time, 
including prior to the issuance of LOAs and further notes the 
regulatory requirement that LOA applicants conduct their own outreach 
with potentially affected subsistence communities. While the commenter 
is correct that communications with Industry are not government-to-
government consultations or government-to-ANCSA corporation 
consultations, such communications have proven to be a productive means 
of resolving potential conflicts and identifying issues that may 
warrant formal consultation with the Service.
    Comment 187: One commenter suggested that the Service should 
reconsider whether Industry activities will have an unmitigable adverse 
impact on subsistence use of marine mammals considering the limit on 
the harvest of SBS polar bears due to their declining population 
abundance.
    Response: The Service disagrees. The ITR concludes that there will 
be no unmitigable adverse impacts on the availability of polar bears 
and has relied on the best scientific information available, monitoring 
data, locations of hunting areas relative to Industry activities, 
community consultation, Plans of Cooperation, and harvest records to 
reach this conclusion.
    Comment 188: One commenter suggested that the Service should 
reconsider whether the addition of new Industry facilities and 
infrastructure will correlate with an increase in incidental harassment 
of polar bears.
    Response: We disagree. While AOGA has drawn a contrary conclusion 
in their Request, the relationship described by the Service between 
distance to shore and polar bear encounters indicates an increase in 
coastal infrastructure will increase the number of encounters and 
subsequent harassment events. This was described at length within the 
ITR.
    Comment 189: Commenters suggested that the Service should clarify 
their explanation for the lack of an oil spill risk assessment.
    Response: Please note that the Service does not authorize the 
incidental take of marine mammals as the result of illegal actions, 
such as oil spills. A detailed, activity-specific analysis of potential 
take arising from a hypothetical oil spill is beyond the scope of this 
ITR. That said, the Service did consider available oil spill risk 
assessments to inform its ITR analysis. References to the various 
materials considered by the Service are provided in the ITR. While we 
used a timeframe ending in 1999 to present one summary statistic, we 
also considered data as recent as 2020. BOEM's OSRA represents the best 
available information on the risk of oil spills to polar bears in the 
Southern Beaufort Sea. We detailed a sample of cases of recent onshore 
oil spills and potential effects on polar bears. The commenter is 
correct that the

[[Page 43068]]

focus of our oil spill analysis was on large oil spills greater than 
1,000 barrels. Spills less than 1,000 barrels are unlikely to cause the 
widespread impacts discussed in the oil spill analysis. Industry is 
required to notify multiple agencies, including the Service, of all 
spills on the North Slope and coordinates spill response accordingly. 
Lastly, as explained in the ITR, ``no major offshore oil spills have 
occurred in the Alaska Beaufort Sea. Although numerous small onshore 
spills have occurred on the North Slope, to date, there have been no 
documented effects to polar bears''.
    Comment 190: One commenter suggested that the Service should 
clarify the requirement for Industry entities to submit a Plan of 
Cooperation.
    Response: We agree. The Service included this information in the 
Description of Letters of Authorization section of the proposed and 
this final rule.
    Comment 191: One commenter suggested that the Service should 
request Industry entities to engage in outreach with subsistence 
communities, including communities in the Bering Strait and Chukchi 
Sea, to ensure Industry vessel activity does not interfere with 
subsistence activities.
    Response: While the Service has included vessel traffic 
restrictions in the ITR as a precautionary measure, AOGA has not 
requested take authorizations for vessel activity through the Bering 
Strait and Chukchi Sea; therefore, no take has been estimated or 
authorized for these activities.
    Comment 192: One commenter suggested that the Service should 
suspend the proposed rulemaking and request AOGA to submit a revised 
request that addresses shortcomings before moving forward with this 
action.
    Response: Thank you for the recommendation, but the Service already 
determined AOGA's revised request to be adequate and complete and finds 
no basis for requiring further revisions.
    Comment 193: One commenter suggested that the Service should be 
more collaborative with NMFS in order to develop, review, and implement 
acoustic and behavior thresholds for marine mammal species.
    Response: Comment noted.

Required Determinations

Treaty Obligations

    This ITR is consistent with the 1973 Agreement on the Conservation 
of Polar Bears, a multilateral treaty executed in Oslo, Norway, among 
the Governments of Canada, Denmark, Norway, the Soviet Union, and the 
United States. Article II of this Polar Bear Agreement lists three 
obligations of the Parties in protecting polar bear habitat. Parties 
are obliged to: (1) Take appropriate action to protect the ecosystem of 
which polar bears are a part; (2) give special attention to habitat 
components such as denning and feeding sites and migration patterns; 
and (3) manage polar bear subpopulations in accordance with sound 
conservation practices based on the best available scientific data.
    This rule will further consistency with the Service's treaty 
obligations through incorporation of mitigation measures that ensure 
the protection of polar bear habitat. Any LOAs issued pursuant to this 
rule would adhere to the requirements of the rule and would be 
conditioned upon including area or seasonal timing limitations or 
prohibitions, such as placing 1.6-km (1-mi) avoidance buffers around 
known or observed dens (which halts or limits activity until the bear 
naturally leaves the den) and monitoring the effects of the activities 
on polar bears. Available denning habitat maps are provided by the 
USGS.

National Environmental Policy Act (NEPA)

    Per the National Environmental Policy Act (NEPA; 42 U.S.C. 4321, et 
seq.), the Service must evaluate the effects of the proposed action on 
the human environment. We have prepared an environmental assessment 
(EA) in conjunction with this rulemaking and have concluded that the 
issuance of an ITR for the nonlethal, incidental, unintentional take by 
harassment of small numbers of polar bears and Pacific walruses in 
Alaska during activities conducted by the applicant is not a major 
Federal action significantly affecting the quality of the human 
environment. A copy of the EA and the Service's FONSI can be obtained 
from the locations described in ADDRESSES.

Endangered Species Act

    Under the ESA, 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. In 2008, the 
Service listed the polar bear as a threatened species under the ESA (73 
FR 28212, May 15, 2008) and later designated critical habitat for polar 
bear subpopulations in the United States, effective January 6, 2011 (75 
FR 76086, December 7, 2010). Consistent with these statutory 
requirements, prior to issuance of this final ITR, we completed intra-
Service section 7 consultation regarding the effects of these 
regulations on polar bears with the Service's Fairbanks' Ecological 
Services Field Office. The Service has found the issuance of the ITR 
will not jeopardize the continued existence of polar bears or adversely 
modify their designated critical habitat, nor will it affect other 
listed species or designated critical habitat. The evaluations and 
findings that resulted from this consultation are available on the 
Service's website and at https://www.regulations.gov.

Regulatory Planning and Review

    Executive Order 12866 provides that the Office of Information and 
Regulatory Affairs (OIRA) in the Office of Management and Budget (OMB) 
will review all significant rules for a determination of significance. 
OMB has designated this rule as not significant.
    Executive Order 13563 reaffirms the principles of Executive Order 
12866 while calling for improvements in the nation's regulatory system 
to promote predictability, reduce uncertainty, and use the best, most 
innovative, and least burdensome tools for achieving regulatory ends. 
The Executive order directs agencies to consider regulatory approaches 
that reduce burdens and maintain flexibility and freedom of choice for 
the public where these approaches are relevant, feasible, and 
consistent with regulatory objectives. Executive Order 13563 emphasizes 
further that regulations must be based on the best available science 
and that the rulemaking process must allow for public participation and 
an open exchange of ideas. We have developed this rule in a manner 
consistent with these requirements.
    OIRA bases its determination of significance upon the following 
four criteria: (a) Whether the rule will have an annual effect of $100 
million or more on the economy or adversely affect an economic sector, 
productivity, jobs, the environment, or other units of the government; 
(b) whether the rule will create inconsistencies with other Federal 
agencies' actions; (c) whether the rule will materially affect 
entitlements, grants, user fees, loan programs, or the rights and 
obligations of their recipients; (d) whether the rule raises novel 
legal or policy issues.
    Expenses will be related to, but not necessarily limited to: The 
development of requests for LOAs; monitoring, recordkeeping, and 
reporting activities conducted during Industry oil and gas operations; 
development of polar bear interaction plans; and coordination with 
Alaska Natives to minimize effects of operations on subsistence 
hunting.

[[Page 43069]]

Compliance with the rule is not expected to result in additional costs 
to Industry that it has not already borne under all previous ITRs. 
Realistically, these costs are minimal in comparison to those related 
to actual oil and gas exploration, development, and production 
operations. The actual costs to Industry to develop the request for 
promulgation of regulations and LOA requests probably do not exceed 
$500,000 per year, short of the ``major rule'' threshold that would 
require preparation of a regulatory impact analysis. As is presently 
the case, profits will accrue to Industry; royalties and taxes will 
accrue to the Government; and the rule will have little or no impact on 
decisions by Industry to relinquish tracts and write off bonus 
payments.

Small Business Regulatory Enforcement Fairness Act

    We have determined that this rule is not a major rule under 5 
U.S.C. 804(2), the Small Business Regulatory Enforcement Fairness Act. 
The rule is also not likely to result in a major increase in costs or 
prices for consumers, individual industries, or government agencies or 
have significant adverse effects on competition, employment, 
productivity, innovation, or on the ability of United States-based 
enterprises to compete with foreign-based enterprises in domestic or 
export markets.

Regulatory Flexibility Act

    We have also determined that this rule will not have a significant 
economic effect on a substantial number of small entities under the 
Regulatory Flexibility Act (5 U.S.C. 601 et seq.). Oil companies and 
their contractors conducting exploration, development, and production 
activities in Alaska have been identified as the only likely applicants 
under the regulations, and these potential applicants have not been 
identified as small businesses. Therefore, neither a regulatory 
flexibility analysis nor a small entity compliance guide is required.

Takings Implications

    This rule does not have takings implications under Executive Order 
12630 because it authorizes the nonlethal, incidental, but not 
intentional, take of walruses and polar bears by Industry and thereby, 
exempts these companies from civil and criminal liability as long as 
they operate in compliance with the terms of their LOAs. Therefore, a 
takings implications assessment is not required.

Federalism Effects

    This rule does not contain policies with federalism implications 
sufficient to warrant preparation of a federalism assessment under 
Executive Order 13132. The MMPA gives the Service the authority and 
responsibility to protect walruses and polar bears.

Unfunded Mandates Reform Act

    In accordance with the Unfunded Mandates Reform Act (2 U.S.C. 1501 
et seq.), this rule will not ``significantly or uniquely'' affect small 
governments. A Small Government Agency Plan is not required. The 
Service has determined and certifies pursuant to the Unfunded Mandates 
Reform Act that this rulemaking will not impose a cost of $100 million 
or more in any given year on local or State governments or private 
entities. This rule will not produce a Federal mandate of $100 million 
or greater in any year, i.e., it is not a ``significant regulatory 
action'' under the Unfunded Mandates Reform Act.

Government-to-Government Coordination

    It is our responsibility to communicate and work directly on a 
Government-to-Government basis with federally recognized Tribes in 
developing programs for healthy ecosystems. We are also required to 
consult with Alaska Native Corporations. We seek their full and 
meaningful participation in evaluating and addressing conservation 
concerns for protected species. It is our goal to remain sensitive to 
Alaska Native culture and to make information available to Alaska 
Natives. Our efforts are guided by the following policies and 
directives:
    (1) The Native American Policy of the Service (January 20, 2016);
    (2) the Alaska Native Relations Policy (currently in draft form);
    (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), and 3342 
(October 21, 2016);
    (5) the Department of the Interior's policies on consultation with 
Tribes and with Alaska Native Corporations; and
    (6) the Presidential Memorandum on Tribal Consultation and 
Strengthening Nation-to-Nation Relationships (January 21, 2021).
    We have evaluated possible effects of the ITR on federally 
recognized Alaska Native Tribes and corporations and have concluded the 
issuance of the ITR does not require formal consultation with Alaska 
Native Tribes and corporations. Through the ITR process identified in 
the MMPA, the AOGA has presented a communication process, culminating 
in a POC if needed, with the Native organizations and communities most 
likely to be affected by their work. The applicant has engaged these 
groups in informational communications. We invite continued discussion 
about the ITR and sent an outreach letter regarding this ITR to Alaska 
Native Tribes and corporations on May 27, 2021.
    In addition, to facilitate co-management activities, the Service 
maintains cooperative agreements with the Eskimo Walrus Commission 
(EWC) and the Qayassiq Walrus Commission (QWC) and is working towards 
developing such an agreement with the newly formed Alaska Nannut Co-
Management Council (ANCC). The cooperative agreements fund a wide 
variety of management issues, including: Commission co-management 
operations; biological sampling programs; harvest monitoring; 
collection of Native knowledge in management; international 
coordination on management issues; cooperative enforcement of the MMPA; 
and development of local conservation plans. To help realize mutual 
management goals, the Service, EWC, ANCC, and QWC regularly hold 
meetings to discuss future expectations and outline a shared vision of 
co-management.
    The Service also has ongoing cooperative relationships with the 
North Slope Borough and the Inupiat-Inuvialuit Game Commission where we 
work cooperatively to ensure that data collected from harvest and 
research are used to ensure that polar bears are available for harvest 
in the future; provide information to co-management partners that 
allows them to evaluate harvest relative to their management agreements 
and objectives; and provide information that allows evaluation of the 
status, trends, and health of polar bear subpopulations.

Civil Justice Reform

    The Department's Office of the Solicitor has determined that these 
regulations do not unduly burden the judicial system and meet the 
applicable standards provided in sections 3(a) and 3(b)(2) of Executive 
Order 12988.

Paperwork Reduction Act

    This rule does not contain any new collections of information that 
require approval by the Office of Management and Budget (OMB) under the 
Paperwork Reduction Act of 1995 (44 U.S.C. 3501

[[Page 43070]]

et seq.). OMB has previously approved the information collection 
requirements associated with incidental take of marine mammals and 
assigned OMB control number 1018-0070 (expires January 31, 2022). 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.

Energy Effects

    Executive Order 13211 requires agencies to prepare statements of 
energy effects when undertaking certain actions. This rule provides 
exceptions from the MMPA's taking prohibitions for Industry engaged in 
specified oil and gas activities in the specified geographic region. By 
providing certainty regarding compliance with the MMPA, this rule will 
have a positive effect on Industry and its activities. Although the 
rule requires Industry to take a number of actions, these actions have 
been undertaken by Industry for many years as part of similar past 
regulations. Therefore, this rule is not expected to significantly 
affect energy supplies, distribution, or use and does not constitute a 
significant energy action. No statement of energy effects is required.

References

    For a list of the references cited in this rule, see Docket No. 
FWS-R7-ES-2021-0037, available at http://www.regulations.gov.

List of Subjects in 50 CFR Part 18

    Administrative practice and procedure, Alaska, Imports, Indians, 
Marine mammals, Oil and gas exploration, Reporting and recordkeeping 
requirements, Transportation.

Regulation Promulgation

    For the reasons set forth in the preamble, the Service amends part 
18, subchapter B of chapter I, title 50 of the Code of Federal 
Regulations as set forth below.

PART 18--MARINE MAMMALS

0
1. The authority citation of part 18 continues to read as follows:

    Authority:  16 U.S.C. 1361 et seq.

0
2. Revise subpart J of part 18 to read as follows:

Subpart J--Nonlethal Taking of Marine Mammals Incidental to Oil and 
Gas Exploration, Development, and Production Activities in the 
Beaufort Sea and Adjacent Northern Coast of Alaska

Sec.
18.119 Specified activities covered by this subpart.
18.120 Specified geographic region where this subpart applies.
18.121 Dates this subpart is in effect.
18.122 Procedure to obtain a Letter of Authorization (LOA).
18.123 How the Service will evaluate a request for a Letter of 
Authorization (LOA).
18.124 Authorized take allowed under a Letter of Authorization 
(LOA).
18.125 Prohibited take under a Letter of Authorization (LOA).
18.126 Mitigation.
18.127 Monitoring.
18.128 Reporting requirements.
18.129 Information collection requirements.


Sec.  18.119  Specified activities covered by this subpart.

    Regulations in this subpart apply to the nonlethal incidental, but 
not intentional, take of small numbers of polar bear and Pacific walrus 
by certain U.S. citizens while engaged in oil and gas exploration, 
development, and production activities in the Beaufort Sea and adjacent 
northern coast of Alaska.


Sec.  18.120  Specified geographic region where this subpart applies.

    This subpart applies to the specified geographic region that 
encompasses all Beaufort Sea waters east of a north-south line through 
Point Barrow, Alaska (N71.39139, W156.475, BGN 1944), and 80.5 km (50 
mi) north of Point Barrow, including Alaska State waters and Outer 
Continental Shelf waters, and east of that line to the Canadian border.
    (a) The offshore boundary of the Beaufort Sea incidental take 
regulations (ITR) region extends 80.5 km (50 mi) offshore. The onshore 
region is the same north/south line at Utqiagvik, 40.2 km (25 mi) 
inland and east to the Canning River.
    (b) The Arctic National Wildlife Refuge and the associated offshore 
waters within the refuge boundaries are not included in the Beaufort 
Sea ITR region. Figure 1 shows the area where this subpart applies.
BILLING CODE 4333-15-P

[[Page 43071]]

[GRAPHIC] [TIFF OMITTED] TR05AU21.018

BILLING CODE 4333-15-C


Sec.  18.121  Dates this subpart is in effect.

    Regulations in this subpart are effective from August 5, 2021, 
through August 5, 2026, for year-round oil and gas exploration, 
development, and production.


Sec.  18.122  Procedure to obtain a Letter of Authorization (LOA).

    (a) An applicant must be a U.S. citizen as defined in Sec.  
18.27(c) and among:
    (1) Those entities specified in the request for this rule as set 
forth in paragraph (b) of this section;
    (2) Any of their corporate affiliates; or
    (3) Any of their respective contractors, subcontractors, partners, 
owners, co-lessees, designees, or successors-in-interest.
    (b) The entities specified in the request are the Alaska Oil and 
Gas Association, which includes Alyeska Pipeline Service Company, 
BlueCrest Energy, Inc., Chevron Corporation, ConocoPhillips Alaska, 
Inc., Eni U.S. Operating Co. Inc., ExxonMobil Alaska Production Inc., 
Furie Operating Alaska, LLC, Glacier Oil and Gas Corporation, Hilcorp 
Alaska, LLC, Marathon Petroleum, Petro Star Inc., Repsol, and Shell 
Exploration and Production Company, Alaska Gasline Development 
Corporation, Arctic Slope Regional Corporation Energy Services, Oil 
Search (Alaska), LLC, and Qilak LNG, Inc.
    (c) If an applicant proposes to conduct oil and gas industry 
exploration, development, and production in the Beaufort Sea ITR region 
described in Sec.  18.120 that may cause the taking of Pacific walruses 
and/or polar bears and wants nonlethal incidental take authorization 
under the regulations in this subpart J, the applicant must request an 
LOA. The applicant must submit the request for authorization to the 
Service's Alaska Region Marine Mammals Management Office (see Sec.  2.2 
for address) at least 90 days prior to the start of the activity.
    (d) The request for an LOA must comply with the requirements set 
forth in Sec. Sec.  18.126 through 18.128 and must include the 
following information:
    (1) A plan of operations that describes in detail the activity 
(e.g., type of project, methods, and types and numbers of equipment and 
personnel, etc.), the dates and duration of the activity, and the 
specific locations of and areas affected by the activity.
    (2) A site-specific marine mammal monitoring and mitigation plan to 
monitor and mitigate the effects of the activity on Pacific walruses 
and polar bears.
    (3) A site-specific Pacific walrus and polar bear safety, 
awareness, and interaction plan. The plan for each activity and 
location will detail the

[[Page 43072]]

policies and procedures that will provide for the safety and awareness 
of personnel, avoid interactions with Pacific walruses and polar bears, 
and minimize impacts to these animals.
    (4) A plan of cooperation to mitigate potential conflicts between 
the activity and subsistence hunting, where relevant. Applicants must 
provide documentation of communication with potentially affected 
subsistence communities along the Beaufort Sea coast (i.e., Kaktovik, 
Nuiqsut, and Utqigvik) and appropriate subsistence user organizations 
(i.e., the Alaska Nannut Co-Management Council, the Eskimo Walrus 
Commission, or North Slope Borough) to discuss the location, timing, 
and methods of activities and identify and mitigate any potential 
conflicts with subsistence walrus and polar bear hunting activities. 
Applicants must specifically inquire of relevant communities and 
organizations if the activity will interfere with the availability of 
Pacific walruses and/or polar bears for the subsistence use of those 
groups. Requests for an LOA must include documentation of all 
consultations with potentially affected user groups. Documentation must 
include a summary of any concerns identified by community members and 
hunter organizations and the applicant's responses to identified 
concerns.


Sec.  18.123  How the Service will evaluate a request for a Letter of 
Authorization (LOA).

    (a) We will evaluate each request for an LOA based on the specific 
activity and the specific geographic location. We will determine 
whether the level of activity identified in the request exceeds that 
analyzed by us in considering the number of animals estimated to be 
taken and evaluating whether there will be a negligible impact on the 
species or stock and an unmitigable adverse impact on the availability 
of the species or stock for subsistence uses. If the level of activity 
is greater, we will reevaluate our findings to determine if those 
findings continue to be appropriate based on the combined estimated 
take of the greater level of activity that the applicant has requested 
and all other activities proposed during the time of the activities in 
the LOA request. Depending on the results of the evaluation, we may 
grant the authorization, add further conditions, or deny the 
authorization.
    (b) In accordance with Sec.  18.27(f)(5), we will make decisions 
concerning withdrawals of an LOA, either on an individual or class 
basis, only after notice and opportunity for public comment.
    (c) The requirement for notice and public comment in paragraph (b) 
of this section will not apply should we determine that an emergency 
exists that poses a significant risk to the well-being of the species 
or stocks of polar bears or Pacific walruses.


Sec.  18.124  Authorized take allowed under a Letter of Authorization 
(LOA).

    (a) An LOA allows for the nonlethal, non-injurious, incidental, but 
not intentional take by Level B harassment, as defined in Sec.  18.3 
and under section 3 of the Marine Mammal Protection Act (16 U.S.C. 
1362), of Pacific walruses and/or polar bears while conducting oil and 
gas industry exploration, development, and production within the 
Beaufort Sea ITR region described in Sec.  18.120.
    (b) Each LOA will identify terms and conditions for each activity 
and location.


Sec.  18.125  Prohibited take under a Letter of Authorization (LOA).

    Except as otherwise provided in this subpart, prohibited taking is 
described in Sec.  18.11 as well as:
    (a) Intentional take, Level A harassment, as defined in section 3 
of the Marine Mammal Protection Act (16 U.S.C. 1362), and lethal 
incidental take of polar bears or Pacific walruses; and
    (b) Any take that fails to comply with this subpart or with the 
terms and conditions of an LOA.


Sec.  18.126  Mitigation.

    (a) Mitigation measures for all Letters of Authorization (LOAs). 
Holders of an LOA must implement policies and procedures to conduct 
activities in a manner that affects the least practicable adverse 
impact on Pacific walruses and/or polar bears, their habitat, and the 
availability of these marine mammals for subsistence uses. Adaptive 
management practices, such as temporal or spatial activity restrictions 
in response to the presence of marine mammals in a particular place or 
time or the occurrence of Pacific walruses and/or polar bears engaged 
in a biologically significant activity (e.g., resting, feeding, 
denning, or nursing, among others), must be used to avoid interactions 
with and minimize impacts to these animals and their availability for 
subsistence uses.
    (1) All holders of an LOA must:
    (i) Cooperate with the Service's Marine Mammals Management Office 
and other designated Federal, State, and local agencies to monitor and 
mitigate the impacts of oil and gas industry activities on Pacific 
walruses and polar bears. Where information is insufficient to evaluate 
the potential effects of activities on walruses, polar bears, and the 
subsistence use of these species, holders of an LOA may be required to 
participate in joint monitoring and/or research efforts to address 
these information needs and ensure the least practicable impact to 
these resources.
    (ii) Designate trained and qualified personnel to monitor for the 
presence of Pacific walruses and polar bears, initiate mitigation 
measures, and monitor, record, and report the effects of oil and gas 
industry activities on Pacific walruses and/or polar bears.
    (iii) Have an approved Pacific walrus and polar bear safety, 
awareness, and interaction plan on file with the Service's Marine 
Mammals Management Office and onsite and provide polar bear awareness 
training to certain personnel. Interaction plans must include:
    (A) The type of activity and where and when the activity will occur 
(i.e., a summary of the plan of operation);
    (B) A food, waste, and other ``bear attractants'' management plan;
    (C) Personnel training policies, procedures, and materials;
    (D) Site-specific walrus and polar bear interaction risk evaluation 
and mitigation measures;
    (E) Walrus and polar bear avoidance and encounter procedures; and
    (F) Walrus and polar bear observation and reporting procedures.
    (2) All applicants for an LOA must contact affected subsistence 
communities and hunter organizations to discuss potential conflicts 
caused by the activities and provide the Service documentation of 
communications as described in Sec.  18.122.
    (b) Mitigation measures for onshore activities. Holders of an LOA 
must undertake the following activities to limit disturbance around 
known polar bear dens:
    (1) Attempt to locate polar bear dens. Holders of an LOA seeking to 
carry out onshore activities during the denning season (November-April) 
must conduct two separate surveys for occupied polar bear dens in all 
denning habitat within 1.6 km (1 mi) of proposed activities using 
aerial infrared (AIR) imagery. Further, all denning habitat within 1.6 
km (1 mi) of areas of proposed seismic surveys must be surveyed three 
separate times with AIR technology.
    (i) The first survey must occur between the dates of November 25 
and December 15, the second between the dates of December 5 and 
December 31, and the third (if required) between the dates of December 
15 and January 15.
    (ii) AIR surveys will be conducted during darkness or civil 
twilight and not during daylight hours. Ideal

[[Page 43073]]

environmental conditions during surveys would be clear, calm, and cold. 
If there is blowing snow, any form of precipitation, or other sources 
of airborne moisture, use of AIR detection is not advised. Flight crews 
will record and report environmental parameters including air 
temperature, dew point, wind speed and direction, cloud ceiling, and 
percent humidity, and a flight log will be provided to the Service 
within 48 hours of the flight.
    (iii) A scientist with experience in the in-air interpretation of 
AIR imagery will be on board the survey aircraft to analyze the AIR 
data in real-time. The data (infrared video) will be made available for 
viewing by the Service immediately upon return of the survey aircraft 
to the base of operations.
    (iv) All observed or suspected polar bear dens must be reported to 
the Service prior to the initiation of activities.
    (2) Observe the exclusion zone around known polar bear dens. 
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 
previously unknown occupied dens be discovered within 1 mile of 
activities, work must cease, and the Service contacted for guidance. 
The Service will evaluate these instances on a case-by-case basis to 
determine the appropriate action. Potential actions may range from 
cessation or modification of work to conducting additional monitoring, 
and the holder of the authorization must comply with any additional 
measures specified.
    (3) Use the den habitat map developed by the USGS. 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. This measure 
ensures that the location of potential polar bear dens is considered 
when conducting activities in the coastal areas of the Beaufort Sea.
    (4) Polar bear den restrictions. Restrict the timing of the 
activity to limit disturbance around dens, including putative and known 
dens.
    (c) Mitigation measures for operational and support vessels. (1) 
Operational and support vessels must be staffed with dedicated marine 
mammal observers to alert crew of the presence of walruses and polar 
bears and initiate adaptive mitigation responses.
    (2) At all times, vessels must maintain the maximum distance 
possible from concentrations of walruses or polar bears. Under no 
circumstances, other than an emergency, should any vessel approach 
within an 805-m (0.5-mi) radius of walruses or polar bears observed on 
land or ice.
    (3) Vessel operators must take every precaution to avoid harassment 
of concentrations of feeding walruses when a vessel is operating near 
these animals. Vessels should reduce speed and maintain a minimum 805-m 
(0.5-mi) operational exclusion zone around feeding walrus groups. 
Vessels may not be operated in such a way as to separate members of a 
group of walruses (i.e., greater than two) from other members of the 
group. When weather conditions require, such as when visibility drops, 
vessels should adjust speed accordingly to avoid the likelihood of 
injury to walruses.
    (4) Vessels bound for the Beaufort Sea ITR region may not transit 
through the Chukchi Sea prior to July 1. This operating condition is 
intended to allow walruses the opportunity to move through the Bering 
Strait and disperse from the confines of the spring lead system into 
the Chukchi Sea with minimal disturbance. It is also intended to 
minimize vessel impacts upon the availability of walruses for Alaska 
Native subsistence hunters. Exemption waivers to this operating 
condition may be issued by the Service on a case-by-case basis, based 
upon a review of seasonal ice conditions and available information on 
walrus and polar bear distributions in the area of interest.
    (5) All vessels must avoid areas of active or anticipated walrus or 
polar bear subsistence hunting activity as determined through community 
consultations.
    (6) In association with marine activities, we may require trained 
marine mammal monitors on the site of the activity or onboard ships, 
aircraft, icebreakers, or other support vessels or vehicles to monitor 
the impacts of oil and gas industry activity on polar bear and Pacific 
walruses.
    (d) Mitigation measures for aircraft. (1) Operators of support 
aircraft shall, at all times, conduct their activities at the maximum 
distance possible from concentrations of walruses or polar bears.
    (2) Aircraft operations within the ITR area will maintain an 
altitude of 1,500 ft above ground level when safe and operationally 
possible.
    (3) 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 walruses or polar bears observed on ice or land. Helicopters may 
not hover or circle above such areas or within 805 m (0.5 mi) of such 
areas. When weather conditions do not allow a 457-m (1,500-ft) flying 
altitude, such as during severe storms or when cloud cover is low, 
aircraft may be operated below this altitude. However, when weather 
conditions necessitate operation of aircraft at altitudes below 457 m 
(1,500 ft), the operator must avoid areas of known walrus and polar 
bear concentrations and will take precautions to avoid flying directly 
over or within 805 m (0.5 mile) of these areas.
    (4) Plan all aircraft routes to minimize any potential conflict 
with active or anticipated walrus or polar bear hunting activity as 
determined through community consultations.
    (e) Mitigation measures for the subsistence use of walruses and 
polar bears. Holders of an LOA must conduct their activities in a 
manner that, to the greatest extent practicable, minimizes adverse 
impacts on the availability of Pacific walruses and polar bears for 
subsistence uses.
    (1) Community consultation. Prior to receipt of an LOA, applicants 
must consult with potentially affected communities and appropriate 
subsistence user organizations to discuss potential conflicts with 
subsistence walrus and polar bear hunting caused by the location, 
timing, and methods of operations and support activities (see Sec.  
18.122 for details). If community concerns suggest that the activities 
may have an adverse impact on the subsistence uses of these species, 
the applicant must address conflict avoidance issues through a plan of 
cooperation as described in paragraph (e)(2) of this section.
    (2) Plan of cooperation (POC). When appropriate, a holder of an LOA 
will be required to develop and implement a Service-approved POC.
    (i) The POC must include a description of the procedures by which 
the holder of the LOA will work and consult with potentially affected 
subsistence hunters and a description of specific measures that have 
been or will be taken to avoid or minimize interference with 
subsistence hunting of walruses and polar bears and to ensure continued 
availability of the species for subsistence use.
    (ii) The Service will review the POC to ensure that any potential 
adverse effects on the availability of the animals are minimized. The 
Service will reject POCs if they do not provide adequate safeguards to 
ensure the least practicable adverse impact on the availability of 
walruses and polar bears for subsistence use.

[[Page 43074]]

Sec.  18.127  Monitoring.

    Holders of an LOA must develop and implement a site-specific, 
Service-approved marine mammal monitoring and mitigation plan to 
monitor and evaluate the effectiveness of mitigation measures and the 
effects of activities on walruses, polar bears, and the subsistence use 
of these species and provide trained, qualified, and Service-approved 
onsite observers to carry out monitoring and mitigation activities 
identified in the marine mammal monitoring and mitigation plan.


Sec.  18.128  Reporting requirements.

    Holders of a Letter of Authorization (LOA) must report the results 
of monitoring and mitigation activities to the Service's Marine Mammals 
Management Office via email at: [email protected].
    (a) In-season monitoring reports. (1) Activity progress reports. 
Holders of an LOA must:
    (i) Notify the Service at least 48 hours prior to the onset of 
activities;
    (ii) Provide the Service weekly progress reports of any significant 
changes in activities and/or locations; and
    (iii) Notify the Service within 48 hours after ending of 
activities.
    (2) Walrus observation reports. Holders of an LOA must report, on a 
weekly basis, all observations of walruses during any industry 
activity. Upon request, monitoring report data must be provided in a 
common electronic format (to be specified by the Service). Information 
in the observation report must include, but is not limited to:
    (i) Date, time, and location of each walrus sighting;
    (ii) Number of walruses;
    (iii) Sex and age (if known);
    (iv) Observer name and contact information;
    (v) Weather, visibility, sea state, and sea-ice conditions at the 
time of observation;
    (vi) Estimated range at closest approach;
    (vii) Industry activity at time of sighting;
    (viii) Behavior of animals sighted;
    (ix) Description of the encounter;
    (x) Duration of the encounter; and
    (xi) Mitigation actions taken.
    (3) Polar bear observation reports. Holders of an LOA must report, 
within 48 hours, all observations of polar bears and potential polar 
bear dens, during any industry activity. Upon request, monitoring 
report data must be provided in a common electronic format (to be 
specified by the Service). Information in the observation report must 
include, but is not limited to:
    (i) Date, time, and location of observation;
    (ii) Number of bears;
    (iii) Sex and age of bears (if known);
    (iv) Observer name and contact information;
    (v) Weather, visibility, sea state, and sea-ice conditions at the 
time of observation;
    (vi) Estimated closest distance of bears from personnel and 
facilities;
    (vii) Industry activity at time of sighting;
    (viii) Possible attractants present;
    (ix) Bear behavior;
    (x) Description of the encounter;
    (xi) Duration of the encounter; and
    (xii) Mitigation actions taken.
    (b) Notification of LOA incident report. Holders of an LOA must 
report, as soon as possible, but within 48 hours, all LOA incidents 
during any industry activity. An LOA incident is any situation when 
specified activities exceed the authority of an LOA, when a mitigation 
measure was required but not enacted, or when injury or death of a 
walrus or polar bear occurs. Reports must include:
    (1) All information specified for an observation report;
    (2) A complete detailed description of the incident; and
    (3) Any other actions taken.
    (c) Final report. The results of monitoring and mitigation efforts 
identified in the marine mammal monitoring and mitigation plan must be 
submitted to the Service for review within 90 days of the expiration of 
an LOA, or for production LOAs, an annual report by January 15th of 
each calendar year. Upon request, final report data must be provided in 
a common electronic format (to be specified by the Service). 
Information in the final (or annual) report must include, but is not 
limited to:
    (1) Copies of all observation reports submitted under the LOA;
    (2) A summary of the observation reports;
    (3) A summary of monitoring and mitigation efforts including areas, 
total hours, total distances, and distribution;
    (4) Analysis of factors affecting the visibility and detectability 
of walruses and polar bears during monitoring;
    (5) Analysis of the effectiveness of mitigation measures;
    (6) Analysis of the distribution, abundance, and behavior of 
walruses and/or polar bears observed; and
    (7) Estimates of take in relation to the specified activities.


Sec.  18.129  Information collection requirements.

    (a) We may not conduct or sponsor and a person is not required to 
respond to a collection of information unless it displays a currently 
valid Office of Management and Budget (OMB) control number. OMB has 
approved the collection of information contained in this subpart and 
assigned OMB control number 1018-0070. You must respond to this 
information collection request to obtain a benefit pursuant to section 
101(a)(5) of the Marine Mammal Protection Act. We will use the 
information to:
    (1) Evaluate the request and determine whether or not to issue 
specific Letters of Authorization; and
    (2) Monitor impacts of activities and effectiveness of mitigation 
measures conducted under the Letters of Authorization.
    (b) Comments regarding the burden estimate or any other aspect of 
this requirement must be submitted to the Information Collection 
Clearance Officer, U.S. Fish and Wildlife Service, at the address 
listed in 50 CFR 2.1.

Shannon A. Estenoz,
Assistant Secretary for Fish and Wildlife and Parks.
[FR Doc. 2021-16452 Filed 8-4-21; 8:45 am]
BILLING CODE 4333-15-P