Marine Mammals; Incidental Take of Polar Bears and Pacific Walruses in the Beaufort Sea and North Slope of Alaska

In accordance with the MMPA and its implementing regulations, we, the U.S. Fish and Wildlife Service (hereafter “FWS” or we), finalize incidental take regulations (ITRs) that facilitate the authorization of the incidental, unintentional take of small numbers of polar bears and Pacific walruses during oil and gas exploration, development, production, and transportation activities in the Beaufort Sea (Alaska and the OCS) and adjacent northern coast of Alaska, not including lands within the Arctic National Wildlife Refuge (ANWR), for a 5-year period. Oil and gas activities include similar types of activities covered by the previous 5-year Beaufort Sea ITRs effective from August 5, 2021, through August 5, 2026 (86 FR 42982, August 5, 2021; revised 90 FR 27398, June 26, 2025).

This final rule is based on our findings that the total takings of polar bears and Pacific walruses during specified activities will impact small numbers of animals, will have a negligible impact on the species or stocks, and will not have an unmitigable adverse impact on the availability of these species or stocks for subsistence use by Alaska Natives. We base our findings on data from monitoring the encounters and interactions between these species and the oil and gas industry; research on these species; oil spill risk assessments; potential and documented effects on these species from similar activities; information regarding the natural history and conservation status of polar bears and Pacific walruses; data reported from Alaska Native subsistence hunters; and predictive modeling. In conjunction with this rulemaking, the FWS has prepared an EA and associated FONSI.

These regulations include permissible methods of taking; mitigation measures to ensure that AOGA activities will have the least practicable adverse impact on these species or stocks, their habitat, and the availability of these species for subsistence uses; and requirements for monitoring and reporting.

Section 101(a)(5)(A) of the MMPA 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 title 50 of the Code of Federal Regulations (CFR) in part 18 (at 50 CFR 18.27(c)) engaged in a specified activity, other than commercial fishing, within a specified geographic region. The Secretary has delegated authority for implementation of the MMPA to the FWS. According to the MMPA, the FWS shall allow this incidental taking for a period of up to 5 consecutive years if we find that the total of such taking:

(1) Will affect only small numbers of individuals of the species or stock;

(2) Will have no more than a negligible impact on the species or stock;

(3) Will not have an unmitigable adverse impact on the availability of the species or stock for taking for subsistence use by Alaska Natives; and

(4) We issue regulations that set forth:

(a) Permissible methods of taking,

(b) Means of effecting the least practicable adverse impact on the species or stock and its habitat and the availability of the species or stock for subsistence uses, and

(c) Requirements for monitoring and reporting of such taking.

If final regulations allowing such incidental take are issued, we may then subsequently issue letters of authorization (LOAs), upon request, to authorize incidental take during the specified activities.

The term “take” means to harass, hunt, capture, or kill, or attempt to harass, hunt, capture, or kill any marine mammal. Harassment for activities other than military readiness activities or scientific research conducted by or on behalf of the Federal Government means “any act of pursuit, torment, or annoyance which (i) has the potential to injure a marine mammal or marine mammal stock in the wild” (the MMPA defines this as “Level A harassment”),

or “(ii) has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering” (the MMPA defines this as “Level B harassment”).

The terms “negligible impact” and “unmitigable adverse impact” are defined in 50 CFR 18.27 (i.e., regulations governing small takes of marine mammals incidental to specified activities) as follows: “Negligible impact” is an impact resulting from the specified activity that cannot be reasonably expected to, and is not reasonably likely to, adversely affect the species or stock through effects on annual rates of recruitment or survival. “Unmitigable adverse impact” means an impact resulting from the specified activity: (1) that is likely to reduce the availability of the species to a level insufficient for a harvest to meet subsistence needs by (i) causing the marine mammals to abandon or avoid hunting areas, (ii) directly displacing subsistence users, or (iii) placing physical barriers between the marine mammals and the subsistence hunters; and (2) that cannot be sufficiently mitigated by other measures to increase the availability of marine mammals to allow subsistence needs to be met.

The term “small numbers” is also defined in 50 CFR 18.27. However, we do not rely on that definition here as it conflates “small numbers” with “negligible impact.” We recognize “small numbers” and “negligible impact” as two separate and distinct requirements for promulgating ITRs under the MMPA (see Ctr. for Biological Diversity v. Salazar, 695 F.3d 893, 904 (9th Cir. 2012)). Instead, for our small numbers determination, we evaluate if the number of marine mammals estimated to be incidentally taken 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 implementing regulations. In promulgating ITRs, we ensure the least practicable adverse impact by requiring mitigation measures that are effective in reducing the impact of specified activities, but not so restrictive as to make specified activities unduly burdensome or impossible to undertake and complete.

In this rule, the term “Industry” includes individuals, companies, and organizations involved in exploration, development, production, and transportation activities of the petroleum industry. Industry activities may result in the incidental taking of Southern Beaufort Sea (SBS) polar bears and Pacific walruses (hereafter “walruses”). The MMPA does not require any party to obtain an incidental take authorization; however, any incidental 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 polar bears and walruses 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 90 FR 27398, June 26, 2025; 86 FR 42982, August 5, 2021; 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.

On September 30, 2025, the FWS received a request from AOGA on behalf of its members and 8 Star Alaska, LLC to promulgate regulations for incidental take of small numbers of polar bears and walruses during oil and gas exploration, development, production, and transportation activities in the Beaufort Sea and adjacent northern coast of Alaska for a period of 5 years (2026-2031) (hereafter referred to as the “Request”). The FWS deemed AOGA's Request as adequate and complete on January 12, 2026.

The AOGA requested regulations that will be applicable to the oil and gas exploration, development, production, and transportation activities of multiple companies specified in the Request. This includes AOGA member companies and 8 Star Alaska, LLC that have applied for these regulations. The companies represented in the Request (as modified via subsequent communication from AOGA concerning membership changes) include: Alyeska Pipeline Service Company; APA Corporation; BlueCrest Energy, Inc.; Chevron Corporation; ConocoPhillips Alaska, Inc. (CPAI); ExxonMobil Alaska Production, Inc. (ExxonMobil); Hex Operating, LLC; Glacier Oil and Gas Corporation (Glacier); Hilcorp Alaska, LLC and Hilcorp North Slope, LLC (Hilcorp); Marathon Petroleum Corporation; Petro Star, Inc.; Repsol; Santos; Shell Exploration and Production Company (Shell); and 8 Star Alaska, LLC (a non-member company).

The activities within the scope of the Request are consistent with the nature of oil and gas activities that have occurred on the Alaska North Slope for decades. Those activities have occurred in parallel with monitoring and reporting that has provided a record of polar bear interactions in connection with such activities. To date, we have not made any determination of an effect on more than small numbers, a more than negligible impact, or an unmitigatable adverse impact on the availability for taking for subsistence use by Alaska Natives for polar bears or Pacific walruses in the Alaska North Slope from oil and gas activities. AOGA has indicated that not all activities described in the Request will actually occur during the ITR period, noting the broad scope of activities in the Request was included to support a comprehensive analysis and account for variability.

In preparing the final rule for the incidental take of polar bears and walruses, we reviewed and considered comments and information from the public on our proposed ITR published in the Federal Register on March 9, 2026 (91 FR 11240). We also reviewed and considered comments and information from the public on our draft EA. Based on public comment on these and other issues in the proposed ITR and draft EA, the final rule reflects the following changes:

The requester asked FWS to clarify the LOA process; specifically requesting FWS issue LOAs for activities within the scope and type of activities described in the Petition without detailed data requirements or new model runs. We have clarified the LOA process in the regulatory text at 50 CFR 18.123.

The requester asked FWS to revisit our predictive estimates for vessel impacts, as they felt some routes were being double counted. Some routes were found to be counted in both the vessel analysis and the surface analysis. We have accordingly updated these estimates.

The requester noted several small editorial errors. These errors did not substantially affect the content of the preamble. They have been corrected.

The requester asked for several small points of clarification in the description of their specified activities. These included clarifying the following: helicopters will not knowingly hover over polar bear dens, ice roads may be used to access wells for plugging and abandonment, unmanned aerial vehicles (UAVs) may be used for environmental studies, geophones may not necessarily be placed in the ground, airborne gravity and airborne magnetic surveys may use rotary or fixed-wing aircraft, and aerial pipeline surveys may be

conducted with fixed-wing aircraft in addition to rotary aircraft. None of these impact any take estimates.

The requester stated the mitigation measure requiring vessels to maintain the “maximum distance possible” from polar bears and walruses was too vague. In response, FWS has changed the language to “maximum distance practicable (805 m (0.5 mi) or greater).” This change does not affect any take estimates. FWS take estimates were calculated under the assumption that polar bears may be harassed within a 1.6 kilometer (km) (1 mile (mi)) impact area surrounding vessels.

The requester stated skirting around facilities is not current practice, is not necessary, and is not operationally possible. We have removed discussion of this mitigation measure. This change does not affect any take estimates.

The requester stated that conducting a required third aerial infrared (AIR) survey of polar bear included in the proposed ITR as an additional mitigation measure is not practicable due to logistical, human safety, and economic factors. As explained below, the FWS concluded that a third AIR survey is not practicable and has removed this additional mitigation measure.

Commenters noted a discrepancy in the title of Subpart J which has been corrected.

The requester and other commentors also noted the substantial differences between the historical data and the results from the predictive model and questioned whether the use of the model accurately estimates “take” of the species under the MMPA. We recognize the limitations of the predictive model and take estimates that significantly exceed historical data and AOGA take estimates. For that reason, the Service affirmatively considers other information and does not give its predictive models more weight than those other sources of information. FWS is clarifying that it considered all information before it, namely: monitoring encounters and interactions between the at-issue species and the oil and gas industry; research on these species; oil spill risk assessments; potential and documented effects on these species from similar activities; information regarding the natural history and conservation status of polar bears and Pacific walruses; and data reported from Alaska Native subsistence hunters; the FWS model; and AOGA's take estimates. FWS considers all these inputs in line with Executive Order (E.O.) 14303, “Restoring Gold Standard Science.” We recognize that, if it considered the model absent considering qualitative factors and AOGA's take estimates, it would not be considering the “best available science.” In other words, considering all these inputs ensures the “best available scientific evidence” is used to support the determinations in this ITR.

We also present in the preamble of this final ITR revised estimates from the FWS predictive modeling efforts, specifically the estimates of impacts to denning bears. Through the process of further streamlining the code for the predictive denning model, we discovered two errors causing inaccurate model outputs. In the first error, dens that had zero cubs naturally (a roughly 7 percent chance in the model) but were simulated to receive lethal or level A harassment were being counted when we summarized the number of dens impacted in those categories. While the simulated den was impacted in terms of the sow, there could not be any harassment of cubs because they did not exist. In the second error, a line of code was identified that was causing an error in the counting of a single category of disturbance events.

The model relies on a simulation of polar bear dens across the landscape, followed by simulated exposure to project activities, and finally simulated disturbance (for some of the dens). We iterate this 10,000 times so that we can account for variation in different aspects of polar bear denning biology (e.g., date of entry, birthdate, number of cubs, emergence date) as well as the random element of whether disturbance occurred based on empirical probabilities. We then calculate summary statistics for each kind of take, such as the probability of occurrence, mean, median, and upper and lower confidence intervals.

One line of code led to a single unaccounted category of dens. These dens were previously undisturbed in early and late denning but disturbed in the post-emergence period. That line of code has been fixed, the remaining code has been reviewed to ensure it does not have similar issues, and a series of auto-check functions have been written to ensure a similar issue doesn't present during future code updates.

To describe the change plainly, instead of coding to “count all the dens specifically marked undisturbed” we changed the code to “count all dens except for those that were marked disturbed.” This change is necessary because the latter statement also selects those dens with a “missing” value where the former does not. Missing values in the code were present because the den was not labeled “disturbed” at the previous denning stages.

As a result of the code repairs, some FWS take estimates have changed. The estimated probability of lethal take has decreased slightly because we were using a den count to calculate the probability, and a small number of zero-cub dens were included in the calculation. Level A and Level B harassment estimates have increased as they now account for impacts to previously undisturbed dens that are simulated to exhibit a disturbance response in the post emergence period. The probabilities of such dens experiencing Level B (applicable to the sow) and Level A harassment (applicable to any cubs) is 28 percent and 72 percent respectively. This is a change from the faulty output, which did not count any take for these dens (i.e., 0 percent take).

These regulations facilitate the authorization of the incidental, unintentional take of small numbers of polar bears and walruses that may result from the specified activities. They do not authorize or “permit” the specified activities themselves. The regulations include:

(1) Permissible methods of taking;

(2) Measures designed to ensure the least practicable adverse impact on polar bears and walruses, their habitat, and on the availability of these species or stocks for subsistence uses; and

(3) Requirements for monitoring and reporting.

Description of Letters of Authorization (LOAs)

An LOA is required to conduct activities pursuant to ITRs. Under these ITRs, eligible parties may request LOAs that would authorize incidental take of polar bears and walruses resulting from the specified activities described in these ITRs. Eligible parties are the member companies and 8 Star Alaska, LLC as specified in AOGA's Request, and their corporate affiliates, respective contractors, subcontractors, partners, owners, co-lessees, designees, or successors-in-interest. Requests for LOAs must be consistent with the activity descriptions and mitigation and monitoring requirements of the ITRs 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, including the timing of work and the nature of work to be conducted; (2) an interaction plan for polar bears and walruses; (3) a site-specific marine mammal monitoring and mitigation plan that specifies the procedures to monitor and mitigate the effects of the

activities on polar bears and walruses; and (4) plans of cooperation (if required as described in Mitigation Measures, below). Once this information has been received, we will evaluate whether the level of activity identified in the LOA request exceeds that analyzed by us in considering the findings made for the total taking allowable under these ITRs. If the level of activity exceeds that analyzed, the FWS may request additional information. For more information on requesting and receiving an LOA, refer to 50 CFR 18.27(f).

The specified geographic region covered by the requested ITRs (Beaufort Sea ITR region, see figure 1, below) encompasses all Beaufort Sea waters (including State waters and OCS waters as defined by the Bureau of Ocean Energy Management) east of a north-south line extending from Point Barrow (latitude 71.39139[deg] N, longitude 156.475[deg] W; Board on Geographic Names (BGN) 1944) to the Canadian border, except for marine waters located within the 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 proposed Beaufort Sea ITR region (approximately 7.9 million hectares (ha) (approximately 19.8 million acres (ac))) is the same region covered in previous regulations set forth in the final rule that published at 86 FR 42982, August 5, 2021 and revised at 90 FR 27398, June 26, 2025. The specified geographic region includes but is not limited to the following oil and gas development areas on the North Slope of Alaska: Nikaitchuq, Oooguruk, Badami, Northstar, Endicott (Duck Island), Liberty, Milne Point, Point Thomson, Prudhoe Bay, Pikka, Quokka, Southern Miluveach, Kuparuk River, Greater Mooses Tooth, Colville River, Horseshoe, and Bear Tooth. [GRAPHIC] [TIFF OMITTED] TR19OC26.000

The specified activities include oil and gas exploration, development, production, and transportation activities within the specified geographic region. This section summarizes the type and scale of Industry activities anticipated to

occur in the Beaufort Sea ITR region from 2026 to 2031. Year-round onshore and offshore Industry activities are anticipated. During the 5- year ITR period, Industry activities are expected to be generally similar in type, timing, and effect to activities evaluated under the prior ITRs. Additional information is available in the Request at https://www.regulations.gov in Docket No. FWS-R7-ES-2026-0694.

Transportation activities will include aircraft operations; vehicle and equipment operations on gravel roads, gravel pads, ice roads, and ice pads; vehicle operations on tundra; and vessel transit and barging operations.

Aircraft operations will consist of personnel and cargo transport flights to support operations, aerial pipeline inspections, and environmental monitoring surveys. Personnel and cargo flights will be conducted routinely throughout the Beaufort Sea ITR region to support operations, and the frequency of these flights may vary depending on the location and type of operation. Fixed-wing aircraft will generally be used to transport personnel and cargo across development areas. Helicopters will be used to transport personnel and cargo to coastal or offshore facilities and to access remote areas. Flight altitude for personnel and cargo transport flights will generally be above 305 meters (m) (1,000 feet (ft)) above ground level unless inclement weather requires a lower flight altitude for personnel safety. Aerial pipeline inspections will be conducted frequently year-round using helicopters, UAVs, or fixed-wing aircraft. Environmental monitoring surveys will be conducted using helicopters, UAVs, or fixed-wing aircraft depending on the type of survey and the frequency of these environmental monitoring surveys will vary across location and time of year during the ITR period.

Vehicle and equipment operations will occur on the existing gravel road system and gravel pads within the ITR region to support operations. Expansion of existing gravel roads and gravel pads as well as construction of new gravel roads and gravel pads will be conducted to support operations as needed throughout the ITR period. Gravel roads and pads typically will be constructed or expanded during the winter, although new gravel placement on the tundra may occur during any season. Equipment that will be used to construct or expand gravel roads and pads includes all-terrain vehicles (ATVs), graders, loaders, excavators, rollers, dump trucks, tractors, bulldozers, vehicles, and other heavy equipment. Gravel road and pad maintenance will occur as needed to support transportation and operations throughout the ITR period. Gravel will be obtained from existing gravel mine sites and new gravel mine sites that may be developed within the ITR region.

During the winter, ice roads and ice pads will be constructed both onshore and offshore to support vehicle and equipment transportation and operations. The number, size, and personnel occupancy of ice roads and pads will vary each winter depending on the operations. Some ice roads will be constructed annually in the same location and other ice roads will be constructed in different locations based on operation requirements that vary during the ITR period. Offshore ice roads, trails, and pads will be constructed on floating sea ice or grounded ice in shallow water (less than 2 m (7 ft)). Offshore ice roads, trails, and pads may be constructed as early as December and be used until May during each winter. Equipment that will be used to construct ice roads, trails, and pads includes tracked vehicles, tractors, snowplows, pump trucks, ATVs, graders, and loaders.

Vehicle operations will occur on the tundra to support surveys, scout transportation routes, conduct environmental monitoring studies, and support infrastructure inspections and maintenance activities. Tundra travel will occur year-round throughout the ITR period. Equipment that will be used for tundra travel includes tracked vehicles, ATVs, snowmachines, Tucker Sno-Cat vehicles, and Rolligons.

Vessel transit and barging operations will support transportation of personnel, equipment, and supplies for operations. There are several marine dock facilities that will be used to support vessel transit and barging operations in the ITR region including West Dock, Oliktok Dock, and other private dock facilities in development areas. West Dock is located on the northwestern shore of Prudhoe Bay east of Point McIntyre. Oliktok Dock is located on the eastern side of West Harrison Bay at Oliktok Point. Maintenance dredging or screeding will be conducted as needed at the marine dock facilities. The majority of the vessel transit and barging operations will occur during the open-water season (July through October). Vessels of various sizes will be used to support transportation activities and may include crew boats, hovercrafts, zodiac vessels, and catamarans. Hovercrafts will also be used to transport personnel and cargo during both the ice-covered season and open-water season. Barges, sealifts, and tugboats will be used to transport facility modules, construction materials, cargo, fuel, and other heavy equipment during the open-water season. Sealifts are anticipated to occur over multiple years of the ITR period to transport facility modules to Oliktok Dock or West Dock, and offloading of sealifts may occur in and around offshore, subtidal, or intertidal areas of the Beaufort Sea. Barge lightering may be used to transfer cargo between vessels to allow vessels to enter shallow water. Barges may be transferred to shallow draft tugs for nearshore transportation. During offloading, barges may be staged offshore if dock space is limited.

A variety of surveys and studies will be conducted such as geophysical surveys, airborne gravity/magnetic surveys, geotechnical surveys, seismic exploration surveys, vibroseis seismic surveys, vertical seismic profiles (VSPs), seafloor imaging, offshore bathymetry surveys, shallow hazard surveys, open-water marine vibroseis surveys, environmental monitoring studies, and AIR surveys to detect polar bear dens. These surveys and studies may occur with routine frequency or be conducted as needed for specific projects. The specific locations and numbers of surveys and studies will vary depending on location-specific and operation-specific needs throughout the ITR period.

Geophysical surveys will be conducted to collect information about subsurface geology. Geophysical survey personnel will survey the surface of the land or seafloor to collect information on near-surface hazards that can be avoided during drilling operations or map deep strata beneath the surface of the ground to search for gas and oil- bearing rock formations. Geophysical surveys will occur routinely at existing development areas.

Airborne gravity and airborne magnetic surveys will record passive measurements of the Earth's gravitational and magnetic fields to collect information on potential geologic structures that may contain oil and gas. Surveys will use rotary-wing or fixed-wing aircraft. Survey flight altitudes for rotary-wing aircraft will range from 91.5 m (300 ft) to 152.4 m (500 ft) above ground level. Survey flight altitude for fixed-wing aircraft will be a minimum of 152.4 m (500 ft) above sea level.

Geotechnical surveys will consist of collecting shallow core samples to provide information about soil conditions where onshore and offshore

roads, pipelines, structures, or other facilities are planned to be constructed or to locate gravel sources. Geotechnical surveys will often occur simultaneously with other operations such as ice or gravel road construction or seismic exploration surveys. Geotechnical survey personnel will generally use winter tundra travel routes to access their survey areas and use a geotechnical drill unit to collect the core samples. A small mobile camp to support the survey personnel and other machinery will often be used during these geotechnical surveys. Geotechnical surveys will occur routinely at existing development areas.

Seismic exploration surveys will collect information on the subsurface structure of rock formations. Sound energy waves will be sent into the ground using an energy source such as an airgun or vibroseis, where different layers within the Earth's crust reflect this energy. These reflected energy waves will be recorded by geophones to identify hydrocarbon-containing structures. Vibroseis seismic operations will use truck-mounted vibrators that emit frequency energy into the ground, and these operations may occur both onshore and on sea ice. Vibroseis seismic operations may consist of 40 to 200 personnel, small and heavy equipment, and a mobile sled-mounted camp to support personnel. Vibroseis seismic operations may occur during the winter from January through May.

The VSP surveys will consist of lowering geophones into a well bore on land and repeatedly activating the energy source to gather seismic data from the well. These surveys will be conducted both on and off a drill pad, extending up to 5 km (3 mi) from the drilling rig, and up to eight personnel will conduct these surveys.

Seafloor imagery surveys will collect information about the seafloor by emitting sound energy towards the seafloor and interpreting the reflected sound energy to create a two-dimensional image of the seafloor and any features or objects on it. Equipment that will be used during these seafloor imagery surveys includes side-scan sonar that is towed behind a vessel. Side-scan sonar will generally emit high- frequency sound greater than 200 kilohertz (kHz).

Offshore bathymetry studies will collect information about the water depth, seafloor contours, hazards, and other environmental conditions. Equipment that will be used during these bathymetry surveys includes echosounders, such as a single-beam or multi-beam sonar device, that is mounted on the vessel's hull or on a side-mounted pole. Single-beam sonar devices emit a high-frequency single pulse of sound to record water depth, and these devices may operate at a frequency of either 100 kHz or 200 kHz. Multi-beam sonar devices will be composed of a transducer array that emits a swath of sound, motion sensor on the vessel, gyrocompass on the vessel, and a sound velocity probe in order to create a three-dimensional view of the seafloor. Multi-beam sonar devices may generally operate at a frequency of 240 kHz.

Shallow hazard surveys will collect information about the seafloor and immediate subsurface. Equipment that will be used during these shallow hazard surveys includes a high-frequency sub-bottom profiler, intermediate-frequency profiler, and a multi-channel system, which is an array of hydrophones towed by a vessel to receive reflected sound energy emitted by the sparker. Different types of sub-bottom profilers may be used depending on the type of seafloor imagery required for the shallow hazard surveys and the general frequency of this equipment may range from 0.3 to 20 kHz.

Open-water marine vibroseis may be conducted as a potential alternative to using traditional airguns for offshore oil and gas surveys. Equipment that will be used during these marine vibroseis surveys includes a vibrating plate or shell to displace water to produce acoustic signals.

Environmental monitoring studies to support oil and gas activities will include but are not limited to those that examine geomorphology (soils, ice content, permafrost); archaeology and cultural resources; vegetation mapping; analysis of fish, bird, and mammal species and their habitat; acoustic monitoring; hydrology; and other freshwater, marine, and terrestrial studies of the Arctic coastal and offshore regions. Environmental monitoring studies may be conducted by individual operators or in cooperation with other entities such as government agencies, academic institutions, or local communities. These environmental monitoring studies will often be conducted in response to regulatory requirements and may occur across multiple years. Equipment that will be used during environmental monitoring studies may include vehicles, vessels, snow machines or tuckers, helicopters, UAVs, or fixed-wing aircraft depending on the type of study. Flight altitudes for fixed-wing aircraft may range from 30 m (98 ft) to 450 m (1,476 ft) depending on the type of study. Environmental monitoring surveys will be conducted to fulfill regulatory and permit requirements and support natural resource exploration and development in the ITR region throughout the ITR period.

AIR surveys will be conducted to detect maternal polar bear dens near Industry each winter. Infrared cameras mounted on a fixed-wing aircraft will be used to detect body heat from denning female polar bears that permeates through the snow.

Drilling, production, and maintenance of operating wells for oil and gas exploration, development, and production at existing facilities will occur throughout the ITR period. Industry also plans to drill new exploration, appraisal, and production wells within the ITR region depending on resources and other factors. The number and location of these well drilling and maintenance activities will vary throughout the ITR period, but the level of these activities is anticipated to be similar to previous years. New wells may require construction of new gravel pads or new gravel roads or ice roads to access well locations. New wells may also require installation of stream crossings, vertical support members (VSMs), pipelines, power cables, and fiber optic cables to support well drilling and production activities. Temporary camps may be established to accommodate personnel during well drilling and production activities as needed. Equipment that will be used to support well drilling, production, and maintenance activities includes drill rigs, pumps, processing facilities, and support infrastructure. Industry plans to conduct plugging and abandonment of wells that are currently suspended or will be suspended during the ITR period. The number of wells that may be plugged and abandoned will vary each year throughout the ITR period, but the level of these activities is anticipated to be similar to previous years. These activities may be supported by aircraft or vehicles using ice roads or the existing road network depending on the location of the well that will be plugged and abandoned.

Artificial and natural islands along the Beaufort Sea coastline may serve as well drilling platforms for offshore production. Artificial islands may be constructed at various times of the year using a combination of gravel, boulders, artificial structures, or ice. Vibratory and impact pile driving will be conducted to install conductor pipes, foundation pipes, and sheet piles to support development of the islands for production. Monitoring and maintenance of the islands used for

production will be conducted as needed throughout the ITR period. Monitoring inspections may use sonar and divers, and these inspections may occur multiple times throughout each year of the ITR period depending on weather and wave conditions.

Support facilities and infrastructure include the Deadhorse Airport, Dalton Highway, and Spine Road to transport personnel, equipment, and supplies across the North Slope of Alaska. Permanent camps will be used to house personnel at operation centers, processing facilities, drill sites, and other similar facilities. Temporary camps may be installed for specific projects or travel with personnel to complete projects as needed. Other support functions will include waste management, emergency response training for personnel, in-water dredging and screeding to remove or deposit sediment materials and smooth the seafloor for in-water operations, and pile driving to construct docks and land structures.

Waste management protocols will be implemented in an effort to minimize interactions with wildlife. Solid waste from camps will be disposed of at the Oxbow Landfill in the Prudhoe Bay Development or other permitted facilities. Food and burnable waste will be incinerated when feasible. Food waste will be carefully managed to avoid attracting wildlife such as placing food waste in wildlife-proof receptacles. Drilling and production waste will be injected into underground injection control disposal wells where it will be inaccessible to wildlife and will not have the potential to contact any sources of groundwater or surface soils. Hazardous waste will be kept inside closed containers and disposed of in accordance with applicable regulations.

Emergency and oil spill response training activities for personnel will occur at various times throughout the year during the ITR period. Oil spill equipment deployment exercises conducted during the ice- covered period will use snowmachines, ATVs, portable generators, skid steer loaders, snow blowers, and various types of equipment to cut ice slots or drill holes through floating sea ice. Other equipment and supplies that will be used during emergency response training activities include vessels, trucks, booms, and sorbents. The location and frequency of emergency and oil spill response training activities will vary depending on the sea ice or winter tundra conditions and training requirements.

In-water dredging and screeding will be conducted to remove and deposit seafloor sediment and smooth the seafloor to support in-water operations. These activities will be conducted during the open-water season of each year at various dock locations including but not limited to Oliktok Dock and West Dock. Dredging may also be conducted during the winter depending on conditions. Equipment that will be used for dredging includes a barge-mounted suction dredge, excavator, or a crane with a dredging bucket on a barge platform. Equipment that will be used for screeding includes a device such as a plow or rake-like structure that is attached to a barge or backhoe.

Pile driving or drilling activities will be conducted to support construction or repair of docks, bridges, and offshore or riverine structures as needed throughout the ITR period. Pile driving activities may include vibratory pile driving, impact pile driving, drilling, and down-the-hole drilling, and the pile driving methods, depending on the project requirements.

The applicant has proposed a decision framework and a number of mitigation measures in section 9 of their Request to minimize the potential effects of proposed activities on polar bears and walruses and effect the least practicable adverse impacts on those stocks. AOGA's proposed measures include mitigation for general avoidance and minimization that apply to a variety of their planned activities as well as measures specific to aircraft and vessels; they have also included in their Request plans for conducting maternal polar bear den surveys and methods for minimizing the impacts of their activities on the subsistence harvest of polar bears and walruses.

The general avoidance and minimization measures proposed in AOGA's Request include maintaining a current polar bear and walrus interaction plan in coordination with the FWS that details their protocols for food and waste management, training, snow removal, polar bear and walrus avoidance and encounters, and polar bear and walrus reporting procedures. The applicant also intends to continue to design facilities and plan projects in such a way that polar bears' access to attractants is reduced. Further, they will maintain designated personnel for specific activities to observe and record observations of polar bears and walruses. Finally, they highlight how they will continue to avoid operating equipment in potential den locations.

Proposed mitigation measures for aircraft use include not flying below an altitude of 457 m (1,500 ft) or within 805 m (0.5 mi) of polar bears or walruses observed on ice or land except in emergency situations. Helicopters will not be allowed to hover or circle over polar bears, known polar bear dens, or walruses. Additionally, the applicant has proposed that if weather conditions prevent flying at an altitude of 457 m (1,500 ft) or higher, that the pilot will avoid areas of known polar bear and walrus concentration.

The proposed measures for vessel use include having observers to monitor for polar bears and walruses during marine operations and maintaining the maximum distance practicable (805 m

(0.5 mi) or greater) from concentrations of polar bears or walruses. Polar bears or walruses observed on land or sea will not be approached within an 805-m (0.5-mi) radius except in the case of an emergency. Furthermore, vessels will not separate groups of two or more walruses and will reduce speed and maintain a minimum 805-m (0.5-mi) exclusion zone around groups of 12 or more walruses in the water or polar bears on ice. Vessels that are over 15 m (50 ft) long will maintain a distance of 805 m (0.5 mi) from any walrus haulout. When visibility is reduced, vessels will adjust speed accordingly to decrease the likelihood of injury to walruses.

LOA holders will survey for maternal polar bear dens via AIR during the early polar bear denning season, in November through January. LOA holders will conduct one AIR survey of all denning habitat within 1.6 km (1 mi) of winter activity. This survey would occur in November or December. LOA holders will also conduct a second survey of denning habitat within 1.6 km (1 mi) of winter activities in the high and moderate denning density zones established by FWS (for more information about the creation of denning density zones and a map, a summary of this information is available in supplemental information on https://www.regulations.gov in Docket No. FWS-R7-ES-2026-0694). The second survey would occur in December or January. Additionally, surveyed locations that yield heat signatures indicating the possible presence of a maternal polar bear den will be re-surveyed. Protocols for conducting the maternal polar bear den surveys are documented in section 9.2 of the Request. If AIR surveys yield any putative polar bear dens within 1.6 km (1 mi) of planned activities, AOGA will consult with the FWS to create a mitigation zone around the suspected den site such that it will not be disturbed by any project activities for the remainder of the denning season (November to April). The applicant has also proposed follow-up surveys via AIR, handheld or vehicle-mounted infrared cameras or binoculars, or the use of unmanned aerial systems (UAS) to confirm den presence or identify when the den is no longer in use. Known active den sites will be monitored by personnel in trucks or off-road vehicles, or by remote cameras that can record or stream data. This monitoring of polar bears' activity can assist with avoiding disturbance, especially during the den emergence period when polar bear sows and cubs make repeated short trips outside before returning to the den. Monitoring will be conducted from an appropriate distance established in consultation with the FWS to avoid disturbance from the monitoring activities. Finally, personnel working during the den emergence period will be trained to look for signs of polar bear dens in their work areas and dedicated personnel may be assigned to monitor work areas for polar bears to protect workers and allow polar bears to pass through undisturbed.

Trained and qualified personnel will continue to monitor for, record, and report polar bear and walrus observations, and initiate mitigation measures (Request, sections 9 and 10). LOA holders will report the efficacy of mitigation measures and any observed effects of Industry activities on these species. Monitoring personnel will complete a training program approved by FWS. Details of the monitoring procedures will be provided in an FWS-approved, site- and project- specific marine mammal monitoring and mitigation plan.

To help ensure that incidental taking of polar bears and walruses does not have an unmitigable adverse impact on the availability of the species for Alaska Native subsistence hunting opportunities, the Request states all LOA applicants will provide the FWS documentation of communication and coordination with Alaska Native communities potentially affected by the specified activity and, as appropriate, with representative subsistence hunting and co-management organizations. If Alaska Native communities or representative subsistence hunting organizations express concerns about the potential impacts of specified activities on subsistence activities, and such concerns are not resolved during this initial communication and coordination process, then a plan of cooperation (POC) must be developed and submitted with the applicant's request for an LOA. In developing the POC, the LOA applicant 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 specified activities will not have an unmitigable adverse impact on the availability of polar bears and walruses for Alaska Native subsistence uses.

Should community outreach result in concerns about adverse impacts to subsistence harvest from the planned activities, the Request states that LOA holders will develop a POC to address those concerns and prevent interference with the subsistence harvest. Regardless of the need for a POC, the applicant will limit the timing of activities (including aircraft- and vessel-based activities) and avoid known locations of importance for the subsistence harvest of polar bears and walruses.

From mid-July to mid-November, SBS polar bears can be found in large numbers and high densities on barrier islands, along the coastline, and in the nearshore waters of the Beaufort Sea, particularly on and around Barter and Cross Islands (Wilson et al. 2017). This distribution leads to a significantly higher number of human-polar bear interactions on land and at offshore structures during the open-water season

than other times of the year. Polar bears that remain on the multi-year pack ice are not typically present in the ice-free areas where vessel traffic occurs, as barges and vessels associated with Industry activities travel in open water and avoid large ice floes.

On land, most polar bear observations occur within 2 km (1.2 mi) of the coastline based on polar bear monitoring reports. Facilities within the offshore and coastal areas are more likely to be approached by polar bears, and they may act as physical barriers to polar bear movements. As polar bears encounter these facilities, the chances for human-polar bear interactions increase. However, polar bears have frequently been observed crossing existing roads and causeways, and they appear to traverse the human-developed areas as easily as the undeveloped areas based on monitoring reports.

A larger percentage of SBS polar bears are spending more time on land during the open-water season, which may increase the risk for human-polar bear interactions (Atwood et al. 2016; Kelner et al. 2022; Rode et al. 2022). It is likely that human-polar bear interactions will occur at some point during the specified activities. Per the Request, operators would maintain human--polar bear interaction plans and attractant management plans, design facilities and plan projects to reduce the possibility of polar bears reaching attractants and humans, and monitor for polar bears. These plans and requirements are designed to reduce human-polar bear interactions and minimize the risks to polar bears and humans when interactions occur. Interaction plans detail how to respond to the presence of polar bears, the chain of command and communication, and required training for personnel. Attractant (e.g., human food, garbage) management plans can prevent polar bears from associating humans with food, which mitigates the risk of human-polar bear interactions (Atwood and Wilder 2021). Information gained from monitoring polar bears near industrial infrastructure can be useful for better understanding polar bear distribution, behavior, and interactions with humans. Tools that may be used to facilitate detection and monitoring of polar bears include bear monitors, thermal cameras, and remotely operated cameras.

The Federal Aviation Administration tests aircraft-produced sound at all measured frequencies (50 hertz (Hz) to 10 kHz) (Healy 1974). At frequencies centered at 5 kHz, jets flying at 300 m (984 ft) produced \1/3\ octave band noise levels of 84 to 124 decibels (dB), propeller- driven aircraft produced 75 to 90 dB, and helicopters produced 60 to 70 dB (Richardson et al. 1995). Thus, the frequency and level of airborne sounds typically produced by aircraft are unlikely to cause either temporary or permanent impairment to polar bear hearing unless polar bears are very close to the sound source (Southall et al. 2019).

Although neither temporary nor permanent hearing impairment is anticipated during the specified activities, aircraft overflights have the potential to elicit behavioral responses from polar bears. Exposure to aircraft overflights is expected to result in short-term behavior changes, such as walking, running, or ceasing to rest and, therefore, has the potential to increase energetic costs. Quigley et al. (2022 and 2024) conducted intentional aircraft overflights above polar bears to determine their responses to overflights. Researchers approached polar bears repeatedly at decreasing altitudes with an average flight altitude of 143 m (469 ft). Polar bears exhibited biologically meaningful behavioral responses during 66.6 percent of experimental overflights. These behavioral responses were significantly correlated with the aircraft's altitude, the polar bear's location (e.g., coastline, barrier island), and the polar bear's activity at the time of the encounter. In a separate study, polar bears associated with dens were exposed to aircraft flying at altitudes of 150 m (492 ft) or less and exhibited various responses that ranged from increased head movement and observation of the disturbance to the initiation of rapid movement and/or den abandonment (Larson et al. 2020). Aircraft activities can impact polar bears across all seasons; however, aircraft have a greater potential to disturb both individuals and groups of polar bears on land during the summer and fall. These onshore polar bears are primarily fasting or seeking alternative terrestrial foods (Cherry et al. 2009; Griffen et al. 2022), and polar bear responses to aircraft overflights may result in metabolic costs to limited energy reserves. To reduce potential disturbance of polar bears during aircraft activities, the Request incorporates mitigation measures, such as minimum flight altitudes (457 m/1,500 ft) over polar bears and their frequently used areas and flight restrictions around known polar bear aggregations, to be conducted when safe to perform these operations during aircraft activities.

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, Lone et al. (2018) found 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. While polar bears typically swim with their ears above water, there are occasions when a polar bear may dive and therefore have its ears below the surface.

Polar bear behavior is expected to be impacted by the presence of humans and equipment in the water. In 2012, during the open-water season, Shell USA, Inc (Shell) vessels encountered a few polar bears swimming in ice-free water more than 112.6 km (70 mi) offshore in the Chukchi Sea. In those instances, the polar bears were observed to either swim away from or approach the Shell vessels, sometimes swimming around a stationary vessel before leaving. In at least one encounter, a polar bear approached, touched, and investigated a stationary vessel from the water before swimming away. We anticipate that polar bears that encounter vessels during the specified activities may have an evasive or curious response, similar to these reports.

Some of the specified activities may introduce noise into the marine environment at sound levels capable of causing a behavioral change or temporary or permanent damage to polar bear hearing. However, the majority of the sound-producing instruments that will be used do not produce in-water sound above the threshold designated for Level B harassment or they do not produce sound within the hearing range of polar bears (for a discussion of this threshold and polar bear hearing see supplemental information on https://www.regulations.gov in Docket No. FWS-R7-ES-2026-0694). Echosounders and side-scan sonar are typically operated at a frequency at or above 200 kHz, which is outside the hearing range for polar bears (Southall et al. 2019). Other equipment types, such as sub-bottom profilers and sparkers may produce sounds within the hearing range of polar bears (2 kHz to 16 kHz and 300 Hz to 1.5 kHz, respectively), and at an estimated sound source level

above the Level B harassment threshold (202 decibels referenced to a pressure of 1 microPascal (dB re 1[micro]Pa)); however, their sound production is typically highly directional and focused within a narrow beam. While exposure to other underwater sounds such as those created by screeding, dredging, pile driving, or anchor handling and thrusting may cause changes in behavior, temporary or permanent changes in hearing sensitivity, or discomfort, polar bears are not expected to be frequently exposed because they do not typically swim with their heads under water unless diving (Lone et al. 2018).

Known or suspected polar bear dens around the oilfield, discovered opportunistically and/or during planned surveys for tracking marked polar bears and detecting polar bear dens, are monitored by the FWS. However, these sites are only a small percentage of the total active polar bear dens for the SBS stock in any given year. Each year LOA and incidental harassment authorization (IHA) holders coordinate with the FWS to conduct surveys to attempt to determine the location of known or suspected polar bear dens and denning habitat within 1.6 km (1 mi) of human activity. Per typical LOA requirements, if a known or suspected den site is located, LOA holders immediately consult with the FWS to determine if additional surveys or mitigation measures are required. The exact prescription of mitigation measures may vary based on the specifics of an individual den site but in the past, after locating a known or suspected den site, FWS has worked with operators to implement various mitigation measures such as activity exclusion zones and 24- hour monitoring of the den site. In their Request, AOGA has committed to “maintain a minimum avoidance distance of 805 m from all polar bears at a den site when operating vehicles, vessels, and aircraft, except in the event of an emergency or a den-specific plan when safe and practicable to do so.” The responses of denning polar bears to disturbance and the consequences of these responses can vary throughout the denning process, which entails four stages: den establishment, early denning, late denning, and post-emergence; definitions and descriptions are provided by Woodruff et al. (2022a) and are also located in the 2021-2026 Beaufort Sea ITRs (86 FR 42982, August 5, 2021; revised 90 FR 27398, June 26, 2025). The probability that denning polar bears will be disturbed by nearby Industry activities and the polar bears' resulting responses to disturbance (den abandonment, early emergence from the den, or early departure from the den site) varies by denning stage (A summary of this information is available in supplemental information on https://www.regulations.gov in Docket No. FWS-R7-ES-2026-0694).

Walruses do not frequently inhabit the Beaufort Sea. The likelihood of encountering walruses during Industry operations is low and limited to the open-water season. During the ITR period, Industry operations may occasionally encounter small groups of walruses swimming in open water or hauled out onto ice floes or along the coast. Industry monitoring data have reported 49 walruses between 1995 and 2023, with only a few instances of disturbance to those walruses (AES Alaska 2015; FWS unpublished data). If walruses are encountered during the specified activities, the interaction could potentially result in disturbance.

Anecdotal observations by walrus hunters and researchers suggest that males tend to be more tolerant of disturbances than females, and individuals tend to be more tolerant than groups. Females with dependent calves are considered least tolerant of disturbances. In the Chukchi Sea, disturbance events are known to cause walrus groups to abandon land or ice haulouts and occasionally result in trampling injuries or cow-calf separations, both of which are potentially fatal. Calves and young animals at terrestrial haulouts are particularly vulnerable to trampling injuries. However, due to the lack of previous walrus haulouts in the ITR region, the most likely potential impacts of the specified activities include displacement from preferred foraging areas, increased stress, energy expenditure, interference with feeding, and masking of communications. Any impact of human presence on walruses is likely to be limited to a few individuals due to their geographic range and seasonal distribution.

The reaction of walruses to vessel traffic is dependent upon vessel type, distance, speed, and previous exposure to disturbances. Walruses in the water appear to be less readily disturbed by vessels than walruses hauled out on land or ice. Furthermore, barges and vessels associated with Industry activities travel in open water and avoid large ice floes or land where walruses are likely to be found. In addition, walruses can use a vessel as a haulout platform. In 2009, during Industry activities in the Chukchi Sea, an adult walrus was observed hauled out on the stern of a vessel.

Walruses hear sounds both in air and in water. They have been shown to hear from 60 Hz to 23 kHz in air (Reichmuth et al. 2020). Tests of underwater hearing have shown their range to be between 1 kHz and 12 kHz with greatest sensitivity at 12 kHz (Kastelein et al. 2002). The underwater hearing abilities of the walrus have not been studied sufficiently to develop species-specific criteria for preventing harmful exposure. However, sound level thresholds have been developed for members of the “other marine carnivore” group of marine mammals. For a discussion of these thresholds information is available in supplemental information on https://www.regulations.gov in Docket No. FWS-R7-ES-2026-0694. As we discussed in Effects of In-Water Activities on Polar Bears, the majority of the sound-producing instruments that will be used during the specified activities will not produce in-water sound above the threshold designated for Level B harassment or they do not produce sound within the hearing range of walruses.

If walruses are present within an ensonified area that reaches Level B harassment thresholds, noise may prevent ordinary communication between individuals and prevent them

from locating one another. The noise may also prevent walruses from using potential habitats in the Beaufort Sea and may have the potential to alter the frequency or duration of behaviors such as feeding, foraging, or nursing. The most likely response of walruses to acoustic disturbances in open water would be for animals to move away from the source of the disturbance. Displacement from a preferred feeding area may reduce foraging success, increase stress levels, and increase energy expenditures.

The FWS reviewed the potential impacts of oil spills on the SBS stock of polar bears and walruses, as well as records of oil spills in the specified geographic region and evaluated oil spill response methods in the specified geographic region. Information from this review can be found in SUPPLEMENTAL INFORMATION at https://www.regulations.gov in Docket No. FWS-R7-ES-2026-0694. Based on this review, the likelihood of a large oil spill in the next 5 years is low. In the unlikely event of a large spill, the likelihood that spills would contaminate areas occupied by large numbers of polar bears or walruses is low. While individual polar 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. Onshore oil spills would not impact walruses unless they occurred on or near beaches or oil moved into the offshore environment. In the event of a spill that occurs during the open-water season, oil could be released into the water column, or it could drift from onshore water sources to offshore areas, possibly encountering a small number of walruses. However, as was 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. 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 or walruses is also low. If a large spill does occur, we conclude that only small numbers of polar bears or walruses are likely to be affected, though some animals may be killed, and there would be only a negligible impact on the SBS polar bear stock or walrus population.

Level B harassment, for nonmilitary readiness activities, is defined as “any act of pursuit, torment, or annoyance which... has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, feeding, or sheltering” (16 U.S.C. 1362(18)). Changes in behavior that disrupt certain behaviors or activities for the affected animal are indicative of take by Level B harassment under the MMPA. Such reactions include, but are not limited to, the following:

Fleeing (running or swimming away from a human or a human activity);

Displaying a stress-related behavior such as jaw or lip- popping, front leg stomping, vocalizations, circling, intense staring, or salivating for polar bears;

Abandoning or avoiding preferred movement corridors such as ice floes, leads, polynyas, a segment of coastline, barrier islands, or other resting sites;

Abandoning prey or feeding areas;

Using a longer or more difficult route of travel instead of the intended path;

Interrupting breeding, sheltering, or feeding;

Moving away at a fast pace (adult) and polar bear cubs or walrus calves struggling to keep up;

Temporary, short-term cessation of nursing or resting (cubs or calves);

Ceasing to rest repeatedly or for a prolonged period (adults); or

Loss of hunting opportunity due to disturbance of prey.

This list is not meant to encompass all possible behaviors; other behavioral responses may be indicative of take by Level B harassment. Relatively minor changes in behavior such as the animal

raising its head or temporarily changing its direction of travel are not likely to disrupt biologically important behavioral patterns, and the FWS does not view such minor changes in behavior as indicative of a take by Level B harassment. It is also important to note that eliciting behavioral responses that equate to take by Level B harassment repeatedly may result in Level A harassment.

To evaluate incidental take of polar bears from the specified activities and inform our MMPA-required findings, we start by considering the estimates of likely incidental take and the analysis of associated impacts provided by the Request. We then identify some inherent uncertainties associated with forecasting impacts in this context, discuss legislative intent concerning how such uncertainties are to be considered in the ITR process, and effectuate that intent via further analysis that considers predictive model results. We then make findings that account for qualitative and quantitative considerations and data, the Request's estimates of likely incidental take, and FWS predictive model results. In light of the inherent uncertainties and challenges with quantifying take and the disparate results produced through different methodologies, the FWS considers its predictive model estimates alongside the requester's predictive estimates, which it derived from a distinct methodology (as described below in The Request's Take Estimation Methods), and various qualitative and quantitative factors. The FWS predictive model results for incidental take of polar bears were not a component of determining the MMPA- required findings in the Beaufort Sea ITRs issued between 1993 and 2016 because the model did not exist. As a part of a change introduced around that time for MMPA-required findings, the first Beaufort Sea ITRs using the FWS predictive model was the most recent 2021-2026 Beaufort Sea ITRs. The FWS is now further refining its approach to evaluate MMPA-required findings with additional information, including recent research, on-the-ground data, and the estimates provided by AOGA. The FWS also recognizes that this approach to rendering MMPA- required findings differs from the approaches used in ITRs and IHAs concerning polar bears since 2021, in which we relied on qualitative and qualitative considerations and predictive model results but not a separate set of incidental take estimates provided by the Requester. The reason for this change relates to the fact that the present Request, in providing the estimates and analysis required by 50 CFR 18.27(d), uses methodologies and assumptions that differ from those employed by FWS's predictive modeling, resulting in different quantitative estimates. In this context, considering the additional types of analysis provided by the Request, while continuing to consider qualitative and quantitative considerations and data, and the FWS predictive modeling results, facilitates a more comprehensive analysis to inform FWS's MMPA-required findings. The approach here also preserves the utility of the regulatory requirement that requests for ITRs provide estimates of likely incidental take. This approach is robust, well-tailored to the present circumstances, and permissible under 16 U.S.C. 1371(a)(5)(A), which does not require quantification at all, let alone prescribe any particular methodology for rendering required findings.

The Request summarized its incidental take methodology as follows:

To estimate incidental take of polar bears and walruses that may occur during the activities described in this petition, AOGA used a weight of evidence (WOE) approach consistent with the guidelines published by the EPA [Environmental Protection Agency] in 2016 (EPA 2016) and Executive Order 14303 (The White House 2025), which states that “[w]hen scientific or technological information is used to inform agency evaluations and subsequent decision-making, employees shall apply a weight of scientific evidence approach.” The WOE framework offers a structured approach to combine multiple sources of evidence and draws on field-verified data to support estimates of incidental harassment of polar bears and Pacific walruses that may occur during the class of oil and gas activities described in [the Petition]. (Request, p. 3-1).

The Request lists “[t]he lines of evidence used to estimate incidental Level B takes by harassment of polar bears and Pacific walruses during the class of oil and gas activities described in [the Petition] and “also used to evaluate and assess the likely anticipated impacts on marine mammals . . . .” The Request's lines of evidence are (Request, pp. 3-2, 3):

2,646 records of 2,830 polar bear sightings within the petition area reported by the oil and gas industry (2014-2024);

Incidental Level B takes by harassment reported during oil and gas activities within the petition area (2014-2024);

Aerial Surveys of Arctic Marine Mammals (ASAMM) program data for the period (2013-2019);

Denning bear case studies (1974-2024) (appendix C.3);

Documented polar bear dens detected within the petition area using AIR (2013-2024);

Documented polar bear dens detected within the petition area by personnel on the ground (2006-2024);

Documented bear responses when mitigation measures were applied by Industry (i.e., avoidance and minimization measures applied for dens located near Industry; section 3.7);

The type, nature, and extent of monitoring protocols carried out by Industry to observe polar bears and dens in the vicinity of oil and gas activities;

Literature review--over 620 data sources (i.e., scientific literature, monitoring reports, field data, etc.) were reviewed and over 240 sources are cited in this petition;

LOA monitoring reports of Pacific walrus sightings (2023- 2024);

Sensitivity Analyses of the USFWS Surface Bear Model (USFWS 2021b) and USFWS Denning Bear Model (USFWS 2025a) (appendix C); and

Comparison of USFWS Denning and Surface Model results using USFWS parameters and AOGA Parameters (USFWS 2021b) (USFWS 2025a) (appendix C).

The Request further notes that:

To estimate take of polar bears and Pacific walruses, the weighted body of evidence listed in table 3-1 was evaluated in terms of quantity (i.e., more lines of evidence enhances reliability), coherence (i.e., logical alignment among different types of evidence improves reliability), lack of bias (i.e., evidence is more reliable when consistent results are observed across studies or time periods), and comprehensiveness (i.e., evidence that covers a broad spectrum of relevant information).

Among the lines of evidence, direct field observations (such as the LOA database (in the Request at appendix C.2), historical bear denning case studies, and walrus sightings) and scientific literature received the highest weighted scores for overall relevance, strength, and reliability.

Higher-weighted evidence is given proportionally more influence in estimating

take in this petition. This does not mean weaker evidence is ignored, but rather that take estimates are guided more by the strongest, most reliable, and most relevant data. AOGA considered all the evidence and determined that the best evidence on which to base a take estimate is the highest 5 years of takes over the last ten years.

The LOA database (appendix C.2) is the most extensive empirical dataset collected regarding industry polar bear monitoring in the world and is well-suited to inform this petition as the data were collected during the same classes of activities, in the same environment and for the same animal populations for which this petition is submitted as described in section 1.2. These data, along with evidence from peer reviewed literature are the best evidence from which to assess potential incidental harassment of polar bears on the surface (i.e., non-denning polar bears). In addition, a total of 64 denning bear case studies, of which 23 are representative of industry activities, were reviewed to assess potential incidental harassment of denning bears for this petition. These written accounts of human discovered dens describe the class of nearby human activities (if any), den location and phenology (i.e., timing), and observed polar bear behaviors, as well as records of dens documented by extensive industry surveys and on-the-ground field operations within the petition area provide the basis for the assessment of potential disturbance to dens during industry activities. Historical data on denning bears dating back to 1974 were used to develop proportional outcomes of potential harassment (rates) and correlative distances for denning bears exposed to human activities, and demonstrate patterns of preferential denning regions in the petition area. Direct field evidence gathered each year using AIR surveys and personnel on the ground offers the most accurate information on potential dens in the petition area. Real data on probable den locations are mapped and distributed to operations every denning season so that dens may be avoided by industry.

The USFWS models for surface and denning bears were considered as relevant evidence, but they received less weight than other evidence such as field observations because sensitivity analyses show the models have weaknesses with respect to reliability and strength.

To estimate the incidental take of Pacific walruses, walrus sighting data reported by vessel-based and aerial surveys (Clarke et al. 2017a, 2018a, 2019, Clarke et al. 2015, Clarke et al. 2017b, Ireland et al. 2016), as well as recent industry observation data were the basis for assessing potential interaction with Pacific walruses during oil and gas industry activities. Notably, the sighting data used in this petition are records of the presence of walruses, not take by incidental harassment. Industry monitoring reports (LOA 24-INC-07, LOA 24-INC-08, and LOA 24-INC-09) reported either no takes of Pacific walruses by incidental harassment or it was unknown whether take occurred. For this reason, this petition uses the Pacific walrus sighting data from these collective sources to estimate Level B take by incidental harassment. These data sources summarize real-world observations, providing direct evidence of interactions between oil and gas activities and polar bears and Pacific walruses, and the result of those exposures. Assessments grounded in these lines of evidence offer the most accurate reflection of what occurs during the oil and gas activities outlined in this petition, instead of relying exclusively on assumptions and modeling. The evidentiary value of this approach, supported by the scientific literature cited throughout this petition, clearly presents patterns of species' presence and interaction with oil and gas operations within the petition area to pragmatically evaluate future interactions. These real-world datasets from which this petition tiers, represent documented proof of complex animal behaviors at the interface with industry activity. (Request, p. 3- 10-11).

The Request details a number of reasons for having a high level of confidence in operators' ability to detect polar bears near Industry activities, including “scientific methods used to detect surface bears and bear dens,” required and effective “[t]raining specific to polar bear identification, reporting and mitigation,” and “emphasis on vigilance and reporting” based on polar bears being a “threat to human safety.” (Request, p. 3-53; see also Request, p. 3-54 stating “[w]hile it is theoretically possible that a bear or bear den in proximity to Industry could go undetected, it is highly unlikely given the necessary vigilance and extensive and continuous monitoring that occurs during oil and gas activities.”). The effectiveness of mitigation measures is also addressed (see, e.g., Request, section 3.7). Provided below is a summary of the Request's estimates of incidental take concerning surface (i.e., non-denning) polar bears and denning polar bears.

In estimating the likely incidental take of surface polar bears, the Request states that “the most recent 10-year period of observational data. . . provides the most reliable estimation of future incidental take of surface bears resulting from the [specified activities]” because “[t]he 2014-2024 period of observational data best reflects recent patterns in polar bear distribution and habitat use in the [Request] area, as well as industry activity, monitoring methods, and reporting practices that are consistent with today's regulatory and operational environment” (Request, p. 3-42). The Request states that the average number of incidental Level B harassments observed “for the recent 10-year period (2014-2024) was 16, with a standard deviation of (SD) of 9.95 and an annual range of 4- 35” (Request, p. 3-42). Also noted is “a trend of increased presence of polar bears in coastal areas and their duration on land, particularly during the ice-free season.” For the purposes of estimating incidental Level B harassment of surface polar bears from the specified activities, the Request “assumes these trends will continue and therefore uses the five highest incidental take years from the most recent 10-year period of observational data as the most reasonable representation of incidental take levels of non-denning bears for the 2026-2031 period” (Request, p. 3-42). This approach resulted in an estimated “annual average of 24” incidental Level B harassments of surface polar bears, “with a SD of 7.62 and an annual range of 15-35” (Request, p. 3-42). The number was derived using a dataset that includes Level B harassment events that occurred during vessel-based and aircraft-based activities, therefore the FWS has assumed AOGA intends the estimate to encompass these activities as well. The Request does not anticipate any forms of incidental take of surface polar bears other than Level B harassment.

Disparities in projections of future impacts can result not only from different interpretations of existing data, but also from use of different assumptions and methods to account for uncertainties. In the present context, several inherent uncertainties increase the difficulty of accurately estimating the future impacts of the specified activities on polar bears. Most notably, based on general observational data and reports along with various scientific studies:

There is variability in how polar bears use the ITR region each year and in how individual polar bears respond (if at all) to Industry activities. This is demonstrated by the 43 Level B takes observed and reported by two operators in the ITR region for calendar year 2025, which is more than a standard deviation above the average annual numbers of the Level B harassment requested.

The detailed observation reports submitted by operators pursuant to MMPA take authorization requirements provide valuable data concerning, among other things, polar bear distribution in the ITR region and how polar bears react (if at all) to industrial stimuli. However, ambient conditions common to the ITR region (e.g., darkness, snow, fog, and wind) can reduce the ability to observe all polar bears (and impacts, if any) in the vicinity of Industry activities.

During the denning timeframe, when a sow's abandonment of her maternal den prior to her cub(s) developing sufficient strength and/or ability to thermoregulate would be presumed to result in mortality of the cub(s), denning sows are thought to exhibit a relatively higher tolerance to disturbance. The existing dataset contains no definitive evidence that an Industry activity caused a maternal den abandonment that resulted in cub mortality. That said, given environmental conditions, the existence of scavengers, and difficulty of observation, it remains possible that this scenario has occurred but was not fully observed. It is also possible that if maternal den abandonment occurred, it was from factors outside Industry activity or that there were no cubs when a den was abandoned. Scenarios outside Industry activity should not be considered take by Industry.

Several scientific studies have found a correlation between premature maternal den emergence and/or premature maternal den site departure and cub survival, suggesting these behavioral responses may result in a decline in cub fitness and associated reduction in cub survival probability. Observations indicating that denning polar bears prematurely emerged from their den and/or prematurely departed from their den site in response to Industry disturbance are rare. Assessment of this potential behavioral response is complicated by natural variability in the times that undisturbed polar bears establish their dens, remain in their dens, and remain at their den sites post- emergence. Any disturbance-caused decline in cub fitness would be difficult to observe, and any associated cub mortality would likely manifest after the family unit has departed from the observable area and onto the sea ice.

The exact numbers and precise locations of maternal polar bear dens that will be established in the ITR region during each winter of the 2026-2031 period is unknown. The exact percentage of those dens that will be successfully detected and avoided by operators is also unknown. Therefore, a proportion of known/avoided to unknown/not avoided cannot be calculated.

The FWS addressed how to consider uncertainties regarding the probability and extent of potential impacts in the ITR context when it developed its implementing regulations at 50 CFR 18.27. Responding to a variety of public comments in its 1989 final rule (54 FR 40338, September 29, 1989), the FWS confirmed that the approach described in its proposed rule accurately interpreted the legislative intent behind the 1986 Amendments to the MMPA:

“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 determinations will be made based on the best available scientific information.” (54 FR 40338 at 40343, September 29, 1989, citing 53 FR 8473 at 8474, March 15, 1988; accord, 132 Cong. Rec. S16305 (Oct. 15, 1986)).

The 1989 final rule continues:

“The Service recognizes the tension that exists between development interests and wildlife resource interests when restrictions on development are predicated upon the existence of adverse impacts that are speculative in nature. To resolve these difficult situations, the legislative history of the 1986 Amendments endorsed the use of a balancing approach to weigh the likelihood of occurrence against the severity of the potential impact: The degree of certainty of occurrence required in these judgments should be inversely proportional to the resultant harm to the overall population. 132 Cong. Rec. S16305 (Oct. 15, 1986). In applying this balancing test, the Service must, of necessity, evaluate each request for specific regulations on a case-by-case basis” (54 FR 40338 at 40343, September 29, 1989).

In the present context, where there exists substantial uncertainty as to the potential impacts of the specified activities, and where high rates of human-caused cub mortality (which has not been observed in the ITR region) could represent a significant effect to the SBS stock of polar bears, the FWS considered the results of its predictive modeling and AOGA's take estimates and other qualitative factors to further inform its balancing. While the legislative history on this point concerns “negligible impact” analyses, the FWS will utilize a similar, comprehensive approach for all MMPA-required findings.

The FWS conducts predictive modeling that entails four main components: processes for estimating incidental take of non-denning polar bears during surface activities, aircraft

activities, and vessel activities, and a process for estimating incidental take of denning polar bears during all operations. A detailed description of these processes, along with the model code and most recent data inputs, is provided at FWS-R7-ES-2025-1628 on https://www.regulations.gov. The FWS's predictive model results provide, among other things, a basis for assessing the probability and severity of potential impacts that the scientific literature suggests are possible but have not been observed or are rarely observed in the ITR region.

The FWS recognizes that all predictive analyses and models have limitations. The FWS further recognizes that its predictive models contribute to take estimates that have exceeded (and are expected to exceed) the number of events where biological consequences indicative of take are observed to result from Industry activities. This is partly because the predictive models are one way to estimate harassment consistent with the MMPA's harassment definitions, which encompass certain acts which have “the potential to” result in certain biological consequences, and to account for any unobserved take. When addressing uncertainties, the models incorporate assumptions that attempt to strike a balance between potential overestimates and potential underestimates, but, overall, are more likely to contribute to an overestimate, rather than an underestimate, of the incidental take of polar bears. Because of these limitations and the likely overestimates of incidental take by its predictive models, this ITR considers a range of qualitative factors, AOGA's take estimates, and its predictive models altogether as the “best available scientific evidence” to support its determinations. FWS acknowledges its awareness this rule represents a shift in approach from that taken in the 2021-2026 ITR and the proposed ITR regarding what constitutes the “best available scientific evidence.” For the reasons discussed here and throughout the preamble, the FWS concludes that the approach to the “best available scientific evidence” in this rule: (1) is permissible under the MMPA; (2) is a better approach than that reflected in the 2021-2026 ITR and the proposed ITR; and (3) is supported by good reasons.

Over the years, the FWS has continually incorporated new data as it becomes available and refined its modeling parameters to improve accuracy to the extent practicable. However, FWS recognizes that solely considering its predictive modelling estimates would not amount to considering the “best available scientific evidence” required to make its determinations.

Each refinement of modeling parameters has been described in the first ITRs or IHA review process in which they were employed (e.g., 90 FR 27398, June 26, 2025; and 90 FR 2718, January 13, 2025). More recent refinements, in addition to incorporating the latest available data, introduced in the present analysis are as follows:

Assessment of the rate of incidental take preceding intentional take: In past incidental take analyses, we explained that intentional take events are usually preceded by incidental Level B harassment, and that since sufficient data were not available to support application of a reliable correction factor, we included all intentional take events in our calculations of incidental take rates as a proxy for estimating incidental take in this context. We identified this assumption as “conservative” in the rulemaking process for the 2021-2026 Beaufort Sea ITRs (86 FR 42982 at 43049, August 5, 2021). To increase accuracy in future analyses, we used a structured review process with designated decision rules to revisit records of intentional take from 2014-2024 to determine whether incidental Level B harassment occurred or potentially occurred prior to the intentional Level B harassment. We found 29 percent of intentional encounters were not preceded by incidental harassment and we apply this correction factor in the present analysis.

Estimation of polar bear re-sighting rate: In past incidental take analyses, we estimated numbers of incidental take of polar bears but lacked sufficient data to further estimate how many individual polar bears would be subjected to those takes. We then provided “small numbers” determinations that identified and applied a conservative assumption that each estimated take would accrue to a different individual polar bear (e.g., 82 FR 42982 at 43039, August 5, 2021). We describe below in our efforts to refine this assumption.

Development of Offshore Polar Bear Encounter Rate: In past incidental take analyses, the FWS has used the coastal polar bear encounter rate to estimate take from offshore activities, while acknowledging the rate was conservative and greater than the actual rate of offshore encounters. At the recommendation of AOGA, we explored the use of data from the National Marine Fisheries Service Aerial Survey of Arctic Marine Mammals (ASAMM). We subset the ASAMM dataset to account for decreased visibility due to sea state and observation limitations. A summary of this information is available in supplemental information on https://www.regulations.gov in Docket No. FWS-R7-ES- 2026-0694. The effort enabled FWS to develop an offshore polar bear encounter rate that enables more accurate estimates of take from vessel activity beyond the barrier islands.

We used the analytical methods presented in previous take authorizations (e.g., 90 FR 27398, June 26, 2025) to estimate the effects of the specified activities on denning polar bears. The statistical model consists of 10,000 iterations of simulated dens that are exposed to the specified activities and potentially disturbed. We estimated 6.5 (median=6; 95 percent posterior credible interval (CI): 1-14) land-based dens in the area of specified activity in AOGA's Request and within a 1.6-km (1-mi) buffer of the activities, annually. Estimates for different levels of take are presented in supplemental information on https://www.regulations.gov in Docket No. FWS-R7-ES- 2026-0694. The distributions of simulated Level A harassments as well as lethal takes due to den abandonment 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.

Due to the low probability of one or more lethal takes occurring either annually (0.12) or in 5-year aggregate (0.43), along with a median value of 0 for either time period, we do not anticipate the specified activities will result in lethal take of polar bears. These estimates do not account for certain mitigation measures that were incorporated into AOGA's Request but have benefits that cannot be quantified in the FWS's modeling approach (e.g., personnel training). Implementation of these mitigation measures could further reduce the probability of take and minimize impacts on denning polar bears.

For our small numbers determination, we consider qualitative considerations, the Request's estimates of likely incidental take, and FWS predictive model results to determine whether the number of polar bears and walruses to be subjected to incidental take are respectively small relative to the population size of the species or stock. These considerations are listed below.

1. Within the specified geographical region, the area of Industry activity is expected to be small relative to the ranges of polar bears and walruses. Specifically, the area of specified activities overlap with 0 percent of the walrus range and 1.9 percent of the US portion of the SBS polar bear range. Walruses and SBS polar bears range well beyond the boundaries of the ITR region. As such, the ITR region itself represents only a subset of the potential

area in which these species may occur. Thus, the FWS concludes that a small portion of the walrus population and SBS polar bear stock may be present in the specified geographic region during the time of the specified activities.

2. The majority of human-polar bear interactions will result in no effect or short-term, temporary behavioral changes. When developing estimates for Level B harassment, the FWS has estimated that there is a 99 percent chance that at least 88 percent of encounters with polar bears on the surface in the open-water season and 80 percent of encounters with polar bears on the surface in the ice season are expected to result in no significant change in a biologically important behavior, and we do not consider those interactions to result in a take. The remainder of polar bear encounters on the surface are anticipated to result in short-term, temporary changes in behavior that are indicative of Level B harassment of the animal.

3. Monitoring requirements and adaptive mitigation measures are expected to significantly limit the number of incidental takes of animals. Holders of an LOA will be required to adopt monitoring requirements and mitigation measures designed to reduce potential impacts of their operations on walruses and polar bears. A full description of the mitigation, monitoring, and reporting requirements associated with an LOA can be found in 50 CFR 18.126-18.128. The Service recognizes that while the benefit of these monitoring and adaptive mitigation measures may not be expressly accounted for in the numerical estimates that follow, to the extent such measures were also used in the past, any mitigative benefit may already be reflected in the LOA database that inform the quantitative estimates.

4. The estimated number of polar bears and walruses that will be harassed by Industry activity is small relative to the number of animals in their stocks.

In their Request, AOGA estimates Level B harassment of 24 polar bears on average each year, plus the estimated 3 denning bears that may be harassed over the entire 5 years, which, assuming all 3 denning bears were harassed in the same year, would be 2.9 percent of a 907- individual SBS polar bear stock. The FWS released a draft stock assessment report (SAR) for the SBS polar bear population on January 2, 2025 (90 FR 114), in which the SBS polar bear stock has changed to 819 polar bears, largely due to a shift in the border between the SBS and North Beaufort Sea stock. Should this draft SAR be finalized, 27 polar bears constitutes 3.3 percent of the SBS polar bear stock.

The FWS predictive model estimates that AOGA's proposed specified activities in the specified geographic region will involve the incidental take of no more than 209 polar bears during the 5-year period of these ITRs (see FWS Predictive Model Estimates: Sum of Harassment from All Sources). The highest estimated number of annual Level A harassment events is 3. The highest total number of polar bears estimated to be incidentally taken by Level A or Level B harassment during any year would be 49, which is 5.4 percent of the best available estimate of the current SBS polar bear stock size of 907 animals (Bromaghin et al. 2015; Atwood et al. 2020; ((49 / 907) x 100[ap]5.4 percent)), and 6.0 percent of a 819-individual SBS polar bear stock ((49 / 819) x 100[ap]6.0 percent)). The FWS considered both sets of numerical estimates in its determination that the number of polar bears that would be incidentally taken is small relative to the size of the SBS polar bear stock.

As stated previously, walruses are extralimital in the Beaufort Sea, with nearly the entire walrus population found in the Chukchi and Bering Seas. Industry monitoring reports have observed no more than 49 walruses between 1995 and 2023, with only a few observed instances of disturbance to those walruses (AES Alaska 2015; FWS unpublished data). Between those years, observations were typically of a single or two animals, often separated by several years. At most, only a tiny fraction of the walrus population, which is composed of hundreds of thousands of animals (Beatty et al. 2022), 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 these ITRs. The estimated incidental take of 20 walruses per year from a population numbering approximately 257,193 animals represents 0.008 percent of that population ((20/257,193)x100[ap]0.008 percent). The FWS considered these numerical estimates in its determination that the number of walruses that would be incidentally taken is small relative to the size of the walrus population.