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

SUPPLEMENTARY INFORMATION:

Background

In accordance with the Marine Mammal Protection Act of 1972, as amended (MMPA; 16 U.S.C. 1371 et seq.), and its implementing regulations, the U.S. Fish and Wildlife Service (Service) finalized incidental take regulations in 2021 (2021-ITRs) in response to a request from the Alaska Oil and Gas Association (AOGA). The request was for regulations to provide for the issuance of letters of authorization (LOA) for incidental take of small numbers of Pacific walruses and Southern Beaufort Sea (SBS) polar bears during specified oil and gas industry (“Industry”) activities in the Beaufort Sea and adjacent northern coast of Alaska over a 5-year period (86 FR 42982, August 5, 2021). The regulations were added to title 50 of the Code of Federal Regulations (CFR) in part 18 at subpart J and expire August 5, 2026. The 2021-ITRs authorize, via Service-issued LOAs, the incidental Level B harassment of up to 15 Pacific walruses and 92 SBS polar bears each year. The 2021-ITRs do not authorize (or facilitate the authorization of) any incidental Level A harassment or lethal take of any marine mammals during specified Industry activities, and any such take remains prohibited by the MMPA.

The term “take” as defined by the MMPA, means to harass, hunt, capture, or kill, or attempt to harass, hunt, capture, or kill any marine mammal (16 U.S.C. 1362(13)). Harassment, as defined by the MMPA, for activities other than military readiness activities or scientific research conducted by or on behalf of the Federal Government, means “any act of pursuit, torment, or annoyance which (i) has the potential to injure a marine mammal or marine mammal stock in the wild” (the MMPA defines this as Level A harassment); or “(ii) has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering” (the MMPA defines this as Level B harassment) (16 U.S.C. 1362(18)).

The 2021-ITRs, along with the accompanying National Environmental Policy Act (NEPA) environmental assessment and Endangered Species Act (ESA) biological opinion, were challenged in litigation that commenced in the United States District Court for the District of Alaska (District Court). On March 30, 2023, the District Court issued summary judgment in favor of the Service upholding the 2021-ITRs. Portions of this ruling were appealed to the United States Court of Appeals for the Ninth Circuit (Appellate Court). On March 19, 2024, a three-judge panel of the Appellate Court issued an order that affirmed in part, and reversed in part, the District Court ruling. The Appellate Court panel declined to vacate the 2021-ITRs but issued a remand that requires the Service to conduct additional analysis and, depending on the results, potentially take regulatory action. In their remand order, specific only to polar bears, the Court directed (omitting internal references): “We . . . remand to the Service to offer a fuller explanation for its determination that no Level A incidents are expected during the period covered by the 2021 ITR. . . . In assessing the `negligible impact' prong on remand, the Service may, consistent with its expertise, emphasize certain outputs over others. However, given the MMPA's two-part conception of take, it must determine whether aggregating serious and non-serious Level A take yields a `reasonably likely' result. . . . If so (as the 75 percent figure proffered by Plaintiffs suggests), the Service will then need to determine (i) whether any Level A take predicted will affect only `small numbers' of bears and have a `negligible impact' on the subpopulation and, if so, (ii) whether to issue an updated ITR covering Level A take or no ITR at all.”

The Court further stated, “Hence, we . . . remand to the Service so that it may (i) aggregate serious and non-serious Level A take together . . . and (ii) determine whether the five-year risk of such take of a denning cub is `reasonably likely'. . . . To the extent that it is, the Service must then evaluate whether the five-year impacts of Level A take is `negligible' and whether such take will be of `small numbers' of bears and possibly amend or reverse the 2021 ITR.”

Accordingly, the Service has conducted additional analysis consistent with the Appellate Court's direction. As discussed below, this new analysis has resulted in preliminary determinations that, while no lethal take is predicted to occur, it is likely that Level A harassments of polar bears will occur, and that authorizing such take is consistent with MMPA standards. Therefore, this proposed rule, if finalized, would amend the 2021-ITRs to allow the issuance of LOAs authorizing take by Level A harassment of polar bears that may result from Industry activities.

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 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 Service. According to the MMPA, the Service shall allow this incidental taking if we find the total of such taking for a 5-year period or less:

(1) will affect only small numbers of marine mammals of a species or population stock;

(2) will have no more than a negligible impact on such species or stocks;

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

(4) we issue regulations that set forth:

(a) permissible methods of taking;

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

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

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

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

The term “small numbers” is also defined in § 18.27. However, we do not rely on that definition here as it conflates “small numbers” with “negligible impacts.” We recognize “small numbers” and “negligible impacts” as two separate and distinct requirements for promulgating incidental take regulations (ITRs) under the MMPA (see Natural Res. Def. Council, Inc. v. Evans, 232 F. Supp. 2d 1003, 1025 (N.D. Cal. 2003)). Instead, for our small numbers determination, we estimate the likely number of takes of marine mammals and evaluate if that take is small relative to the size of the species or stock.

The term “least practicable adverse impact” is not defined in the MMPA or its enacting regulations. The Service ensures the least practicable adverse impact by requiring mitigation measures that are effective in reducing the impact of Industry activities but are not so restrictive as to make Industry activities unduly burdensome or impossible to undertake and complete.

The MMPA does not require Industry to obtain an incidental take authorization; however, any taking that occurs without authorization is a violation of the MMPA. Since 1993, the oil and gas industry operating in the Beaufort Sea and the adjacent northern coast of Alaska has requested, and we have issued, ITRs for the incidental take of Pacific walruses and polar bears within a specified geographic region during specified activities. For a detailed history of our current and past Beaufort Sea ITRs, refer to the Federal Register at 81 FR 52276, August 5, 2016; 76 FR 47010, August 3, 2011; 71 FR 43926, August 2, 2006; and 68 FR 66744, November 28, 2003. The current regulations are codified at 50 CFR part 18, subpart J (§§ 18.121 through 18.129), and were published in the Federal Register on August 5, 2021 (86 FR 42982).

Proposed Changes to 50 CFR Part 18, Subpart J

Our reanalysis, as discussed in detail below, indicates that Level A harassment of polar bears is reasonably likely to occur during the 5-year effective period of the 2021-ITRs. Therefore, we are proposing revisions to our regulations that, if finalized, would allow the Service to authorize take by both Level A and Level B harassment of polar bears. The lethal incidental take of polar bears would continue to be prohibited under this proposed revision, as would any Level A harassment or lethal take of Pacific walrus.

New Information and Analysis

Aggregated Level A Harassment Across 5-Year Period

In conducting the additional analysis required by the Court's remand, the Service utilized best available scientific evidence. New information has been acquired and several advancements in the Service's analytical methods have been made subsequent to the promulgation of the 2021-ITRs. Many of these advancements were recently described and considered in an incidental harassment authorization that was issued by the Service to the Bureau of Land Management (88 FR 88943, December 26, 2023).

Specifically, the denning analysis described in the 2021-ITRs was conducted using the simulation of annual land-based maternal polar bear dens, spatially and temporally explicit descriptions of Industry activity, and predictions of polar bear response rooted in distributions established from den disturbance case studies ( see86 FR 42982, August 5, 2021). For each of the five winter seasons analyzed in the 2021-ITRs, a series of dens were simulated by assigning each a location on the landscape, the sow's entrance date, the number of cubs she bore, the cub(s)' birthdate, den emergence date, and den departure date. We then overlaid the season's Industry activity across the same landscape and simulated whether polar bears within maternal dens that fell within a mile of activity responded to Industry-caused disturbances, and if so, how. Potential responses include disturbance of the sow inside the den, den abandonment, early emergence from the den, and early departure from the den site. Polar bear disturbance responses that occurred during the den establishment period were estimated to result in Level B harassment of the sow (no cubs are present during this period). Responses that occurred during the early denning period were estimated to result in Level B harassment of the sow and lethal take of the cub(s). Responses that occurred during the late denning period were estimated to result in Level B harassment of the sow and “serious Level A harassment” ( i.e., likely to result in cub mortality) of the cub(s). Responses during the post-emergence period were estimated to result in Level B harassment of the sow and “non-serious Level A harassment” ( i.e., not likely to result in cub mortality) of the cub(s).

The denning model was created to assess individual denning seasons and has included several levels of assumptions that generate an estimate of the potential annual impacts to denning polar bears that is somewhat conservative in that it is more likely to overstate, rather than understate, potential impacts. Use of this methodology achieved the objective of ensuring that actual impacts would not exceed what was contemplated in the incidental take authorization and would remain consistent with applicable MMPA thresholds. However, when applied to activities spanning a 5-year period, conservative aspects of certain model assumptions are amplified in a manner that risks unduly overstating projected aggregate impacts, raising the possibility that incidental take resulting from specified activities with acceptable levels of impacts could not be authorized, a scenario that would be inconsistent with the intent of section 101(a)(5)(A) of the MMPA. Thus, in complying with the remand's direction to aggregate Level A harassment estimates over a 5-year period, we reexamined the denning model to incorporate newly available scientific evidence and further refine certain model assumptions where appropriate to achieve greater accuracy.

Since 2021, LOA applicants have annually provided the Service with revised project descriptions and geospatial files that more precisely reflected the scope of their planned activities to be conducted during the ensuing (1-year) LOA period, as compared with the descriptions of specified activities provided during development of the 5-year ITRs. We used the revised files in the present analysis as they constitute the best available information concerning the scope of Industry's specified activities. We also account for AOGA's clarification that no onshore terrestrial seismic surveys will occur during the winter of 2024-2025. Potential seismic surveys in the winter of 2025-2026 remain within the scope of AOGA's specified activities and were analyzed during our re-analysis.

As a condition of their authorizations, LOA holders also submit records of all polar bear encounters during their activities. Using this information, and records from separate activities that were not operating under the 2021-ITRs, we incorporated data from recently observed dens into our disturbance probabilities and litter size distributions, modified the model to incorporate newly published data that describes the relationship between den emergence date, den departure time, and litter survival (Andersen et al. 2024), and updated the simulation of dens across the landscape to now include several previously unidentified areas that may sustain polar bear dens.

Four known dens (monitored in 2022 and 2023) have occurred near human activity since the promulgation of the 2021-ITRs. Of the four newly observed dens, three were extremely close to human activity (<50 meters), yet the sows remained in their dens until the late denning period. We updated polar bear disturbance probabilities and litter size distributions with the information from these dens, then reexamined the historic dens that were used to create disturbance probabilities. We found that the distances between human activity and polar bear dens that experienced an observed disturbance response during the early denning period were considerably closer than those dens that experience an observed disturbance response during other denning periods. Specifically, of the 15 dens within the case studies that were exposed to human activity during the early denning period, only 1 was potentially disturbed at a distance greater than 800 meters. This single den record also had imprecise information on the distance to human activity, so activity was assumed to occur within 1,610 meters of the den and was likely closer.

The historic dens analyzed during the den establishment, late denning, and post-emergence periods did not follow this pattern. For those dens, disturbance distances commonly exceeded 805 meters. Evidence derived from dens exposed to human activity during the early denning period, including both new den records and historic dens, illustrates the reluctance of sows to abandon their maternal den/cubs in response to exposure to stimuli from nearby activity and support the concept that sows may be more risk tolerant during the early denning period. Additionally, sows may be less affected by sound from outside activities during the early denning period because dens are typically closed during that time, which can reduce propagation of noise into the den (Owen et al. 2021). Given this evidence, we modified the denning analysis model to adjust the impact area for the early denning period to range from 0 to 805 meters. As a result, dens that were simulated to be within 805 meters of human activity could be disturbed during all denning periods, while dens between 806-1,610 meters of human activity could be disturbed only during the den establishment, late denning, and post-emergence periods.

Finally, the method for categorizing certain disturbance responses was modified to comply with the Court's direction to provide aggregated estimates of Level A harassment and to better align the model results with the categories of “take” defined in the MMPA. In the preamble to the 2021-ITRs, we drew a distinction between “serious Level A” and “non-serious Level A” harassment and largely addressed these categories separately. If a sow and cub(s) emerged early ( i.e., during the late denning period), the litter was assigned serious Level A harassment(s). If the sow and cub(s) departed the den site early ( i.e., during the post-emergence period), the litter was assigned non-serious Level A harassment(s). These categories were based on the historic den disturbance case studies. Now we omit the “serious”/“non-serious” dichotomy and instead report results that aggregate all estimated Level A harassments. If an exposure resulted in disturbance during either of these periods, we assigned a Level A harassment to each cub in the litter (table 1).