Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Hilcorp Alaska, LLC Production Drilling Support in Cook Inlet, Alaska

SUPPLEMENTARY INFORMATION:

Background

The MMPA prohibits the “take” of marine mammals, with certain exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) direct the Secretary of Commerce (as delegated to NMFS) to allow, upon request, the incidental, but not intentional, taking of small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and either regulations are proposed or, if the taking is limited to harassment, a notice of a proposed IHA is provided to the public for review.

Authorization for incidental takings shall be granted if NMFS finds that the taking will have a negligible impact on the species or stock(s) and will not have an unmitigable adverse impact on the availability of the species or stock(s) for taking for subsistence uses (where relevant). Further, NMFS must prescribe the permissible methods of taking and other “means of effecting the least practicable adverse impact” on the affected species or stocks and their habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance, and on the availability of the species or stocks for taking for certain subsistence uses (referred to in shorthand as “mitigation”); and requirements pertaining to the monitoring and reporting of the takings. The definitions of all applicable MMPA statutory terms cited above are included in the relevant sections below.

Summary of Request

On August 2, 2023, NMFS received a request from Hilcorp for an IHA to take marine mammals incidental to production drilling support activities in Cook Inlet, Alaska. Following NMFS' review of the application, Hilcorp submitted revised versions on September 29, 2023, December 27, 2023, February 29, 2024, and April 8, 2024. The application was deemed adequate and complete on April 12, 2024, and the notice for the proposed IHA was published in the Federal Register on July 24, 2024 (89 FR 60164). Hilcorp's request is for take of 12 species of marine mammals, by Level B harassment. Neither Hilcorp nor NMFS expect serious injury or mortality to result from this activity and, therefore, an IHA is appropriate.

NMFS previously issued two consecutive IHAs to Hilcorp for similar work (87 FR 62364, October 1, 2022). Hilcorp complied with all the requirements ( e.g., mitigation, monitoring, and reporting) of the previous IHAs, and information regarding their monitoring results may be found in the Potential Effects of Specified Activities on Marine Mammals and their Habitat section of this notice.

There are no changes from the proposed IHA to the final IHA other than the addition of some clarifying language and some minor typographical corrections.

Description of Specified Activity

Hilcorp plans to use three tug boats to tow and hold, and up to four tug boats to position, a jack-up rig to support production drilling at existing platforms on 6 non-consecutive days during a 1-year period, in middle Cook Inlet and Trading Bay Alaska. Tug activities will include one demobilization effort of a jack-up rig (Spartan 151 or equivalent rig) from an existing platform to Rig Tenders Dock in Nikiski, one jack-up rig relocation between existing platforms, and one remobilization effort of the jack-up rig from Rig Tenders Dock in Nikiski to middle Cook Inlet. Noise produced by tugs under load with a jack-up rig may result in take, by Level B harassment, of 12 marine mammal species. References to tugging activities herein refer to activities where tugs are under load with the rig ( i.e., tugs towing, holding, and or positioning a jack-up rig).

A detailed description of the planned tugging activities is provided in the Federal Register notice for the proposed IHA (89 FR 60164, July 24, 2024). Since that time, no changes have been made to the planned activities. Therefore, a detailed description is not provided here. Please refer to that Federal Register notice for the description of the specific activity.

Comments and Responses

A notice of NMFS' proposal to issue an IHA to Hilcorp was published in the Federal Register on July 24, 2024 (89 FR 60164). That notice described, in detail, Hilcorp's activity, the marine mammal species that may be affected by the activity, and the anticipated effects on marine mammals. In that notice, we requested public input on the request for authorization described therein, our analyses, the proposed authorization, and any other aspect of the notice of proposed IHA, and requested that interested persons submit relevant information, suggestions, and comments.

During the 30-day public comment period, NMFS received comments from Hilcorp, the Center for Biological Diversity (CBD), and Cook Inletkeeper. All relevant, substantive comments, and NMFS' responses, are provided below and are organized by topic. The comments and recommendations are available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. Please see the comment submissions for full details regarding the recommendations and supporting rationale.

Comment 1: Hilcorp requests that NMFS provide context for the term “serious” as used in the description of effects that temporary threshold shifts (TTS) can have on marine mammals included in the Federal Register notice for the proposed IHA (89 FR 60164, July 24, 2024) and/or edit for better accuracy.

Response: NMFS reviewed the referenced text provided in the Potential Effects of Specified Activities on Marine Mammals and Their Habitat of the notice of proposed IHA, which is referenced in this notice. We determined the discussion was sufficiently clear as originally written.

Comment 2: Hilcorp requests that NMFS clarify that NMFS has found permanent threshold shifts (PTS) to not be likely based on the modeling results provided in the Federal Register notice for the proposed IHA (89 FR 60164, July 24, 2024).

Response: NMFS concurs that PTS resulting from Hilcorp's tugging activities is unlikely. As described in the Federal Register notice for the proposed IHA (89 FR 60164, July 24, 2024), Hilcorp contracted SLR Consulting to model the extent of the harassment isopleths for tugs under load with a jack-up rig during their planned activities. The modeling efforts used detailed propagation calculations that accounted for local bathymetry and specific sound source locations and frequency-dependent propagation effects in an attempt to improve the representation of the influence of relevant environmental variables on the propagation of sound from Hilcorp's planned activities. The results of these modeling efforts estimated distances to PTS thresholds under the mobile tug scenarios that are smaller than the overall size of the tug and rig configuration ( i.e., less than or equal to 8 meters (m)), making it unlikely an animal would remain close enough to the tug engines to incur PTS. For stationary positioning of the jack up rig, the PTS isopleths for both the 3-tug and 4-tug scenarios were estimated to be up to 749 m for high frequency (HF) cetaceans and up to 102 m for all other species, but calculated on the assumption that an animal would remain within several hundred meters of the jack-up rig for the full 5 hours of noise-producing activity. Given the location of the activity is not in an area known to be essential habitat for any marine mammal species with extreme site fidelity, in addition to the mobile nature of marine mammals and the likelihood of avoidance, NMFS concurs that the occurrence of PTS is unlikely and thus, Level A harassment was not proposed or authorized for any species.

Comment 3: Hilcorp requests that NMFS clarify that the required mitigation measures will reduce Level B harassment as well as the already insignificant potential for Level A harassment as a result of the specified activity.

Response: As described in NMFS' response to Comment 2, there is a discountable potential for marine mammals to incur PTS from the project. Source levels from Hicorp's tugging activities are anticipated to be relatively low, non-impulsive, and animals would have to remain at very close distances for multiple hours to accumulate acoustic energy at levels that could damage hearing. We agree that mitigation measures required by NMFS are expected to be effective in further reducing the potential for Level A and Level B harassment and minimizing impacts of the specified activity. These measures include the employment of multiple protected species observers (PSOs), vessel maneuvering restrictions, pre-clearance monitoring prior to commencing activities (which includes a measure that Hilcorp must delay any tugging activities should Cook Inlet beluga whales (CIBWs) be observed at any distance or if other marine mammals are observed within a 1.5 kilometer (km) clearance zone) as well as a requirement that Hilcorp must conduct tugging activities with a favorable tide to reduce noise output. These required measures should reduce any effects of the specified activity on marine mammals by minimizing the numbers of marine mammals exposed to sound and by minimizing the intensity of any exposures. Please see the Mitigation section of this notice for a full description of the required mitigation measures.

Comment 4: Hilcorp notes that some of the densities reported in the Federal Register notice for the proposed IHA (89 FR 60164, July 24, 2024) did not match those included in the Hilcorp application.

Response: Hilcorp correctly identified a typo in table 10 of the notice of proposed IHA (89 FR 60164, July 24, 2024) regarding the density of minke whales. The table included a density of 0.0004 individuals per kilometers squared (km² ), whereas Hilcorp's application included a density of 0.00003 individuals per km² . That table (table 9 in this notice) has been corrected to include the correct density estimate of 0.00003 individuals per km² for this species.

Hilcorp also commented that the density value for CIBWs based on MML annual surveys for the entire Cook Inlet reported in table 10 in the notice for the proposed IHA (89 FR 60164, July 24, 2024) ( i.e., 0.07166 individuals per km² ) does not align with other numbers provided in that table for CIBWs. This value was calculated as the average density of CIBWs in the entire Cook Inlet from 2000 through 2022 as indicated by table 16 in Hilcorp's application and is included in table 9 of this notice.

Comment 5: Hilcorp requests that NMFS specify that Hilcorp's activity will not cause repeated, sequential exposure or repetitious sounds. They also state that the best available information shows no potential for any population level impacts.

Response: As described in the Negligible Impact Analysis and Determination section of the notice for the proposed IHA (89 FR 60164, July 24, 2024) and this notice, we describe how repeated, sequential exposure to elevated noise or repetitious sounds from tugs under load with a jack-up rig over a long duration could result in more significant impacts to individuals that could affect a population (via sustained or repeated disruption of important behaviors such as feeding, resting, traveling, and socializing; Southall et al., 2007). It is unlikely that any individual would be exposed to repeated, sequential exposures or repetitious sounds from Hilcop's activities given the short duration of Hilcorp's tugging activities ( i.e., 6 non-consecutive days over a 1-year period), and the low densities of marine mammals in the planned action area (see tables 10 in the notice for the proposed IHA (89 FR 60164, July 24, 2024) and table 9 in this notice). However, the potential for some repeat, sequential exposure or repetitious sounds from Hilcorp's tugging activities, though limited, does exist given that NMFS does not know with certainty that any individuals would not be exposed to Hilcorp's activity more than once.

Despite the small potential for limited repeated, sequential exposure or repetitive sounds from Hilcorp's tugging activities, NMFS concurs with Hilcorp that the best available science supports the notion that exposure to tugging activities would not have impacts on the fitness or reproductive success of any individual marine mammals, much less population level impacts. Marine mammals, including CIBWs, frequent and use Cook Inlet despite being exposed to anthropogenic sounds such as those produced by tug boats and other vessels across many years. The absence of any pinniped haul outs or other known home-ranges in the planned action area further decreases the likelihood of any population level impacts. As described in the Description of Sound Sources for the Specified Activities section of the notice for the proposed IHA (89 FR 60164, July 24, 2024), while marine mammals may be present in low numbers during Hilcorp's tugging activities, most individuals, including CIBWs, are anticipated to be transiting through the area, limiting exposure duration. CIBWs in the area are expected to be headed to or from the concentrated foraging areas farther north near the Beluga River, Susitna Delta, and Knik and Turnigan Arms. Similarly, humpback whales ( Megaptera novaeangliae), fin whales ( Balaenoptera physalus), minke whales ( Balaenoptera acutorostrata), gray whales ( Eschrichtius robustus), killer whales ( Orcinus orca), California sea lion ( Zalophus californianus), and Steller sea lions ( Eumetopias jubatus) are not expected to remain in the area of the tugs. Dall's porpoise ( Phocoenoides dalli), harbor porpoise ( Phocoena phocoena), and harbor seal ( Phoca vitulina) have been sighted with more regularity than many other species during oil and gas activities in Cook Inlet, but due to the transitory nature of these species, they are unlikely to remain close to a tug under load for the full duration of the noise-producing activity. Further, previous observations of marine mammals sighted near Hilcorp's planned activities have shown little to no observable reactions to tugs under load with a jack-up rig ( e.g., Horsley and Larson, 2023).

Lastly, no serious injury or mortality is anticipated to result from this activity. Take by Level A harassment (injury) is considered unlikely and is not authorized because of the small estimated Level A harassment zones resulting from tugs under load with a jack-up rig ( i.e., ≤8 m during mobile tugging activities and ≤749 m for stationary tugging activities), the mobile nature of both the activity itself and marine mammals in the project area, and the required mitigation and monitoring program. Any take that may potentially occur would be in the form of Level B harassment, likely in the form of avoidance of the vessels and the noise they produce. Please see the Negligible Impact Analysis and Determination section of the notice for the proposed IHA (89 FR 60164, July 24, 2024) and this notice for more detailed information regarding why population level impacts resulting from the additional noise produced by tugs under load with a jack-up rig are not anticipated.

Comment 6: Hilcorp suggests that because the MMPA requires NMFS to use the “best scientific information available”, NMFS should use the CIBW abundance estimate of 331 from Goetz et al. (2003) as described in the footnote of table 12 of the Federal Register notice for the proposed IHA (89 FR 60164, July 24, 2024) rather than 271 from the most recent Stock Assessment Report (Young et al., 2023) when considering the percentage of the stock proposed to be authorized for taking.

Response: As noted by Hilcorp, the abundance estimate provided by Goetz et al. (2023) is the most recent CIBW abundance estimate available. Footnotes 8 and 4 in tables 2 and 12, respectively, of the notice of the proposed IHA (and table 1 and table 11 in this notice) also state that “in accordance with the MMPA, this population estimate will be incorporated into the CIBW SAR, which will be reviewed by an independent panel of experts, the Alaska Scientific Review Group. After this review, the SAR will be made available as a draft for public review before being finalized.” Even when more recent abundance estimates are available, NMFS typically considers abundance estimates from the SARs to be the best available given the rigorous SAR review process. However, in this case, regardless of whether the number of instances of takes is compared to the abundance estimate in the current CIBW SAR or the Goetz et al. (2023) abundance estimate, the number of instances of take as a percent of the stock abundance is less than 6 percent and is considered to be small numbers even if each instance of take represents a different CIBW.

Comment 7: Hilcorp requests that NMFS delete the requirement of the proposed IHA that they must monitor the project area to the maximum extent possible based on the required number of PSOs, required monitoring locations, and environmental conditions. They state that Hilcorp is not required to “monitor the project area to the maximum extent possible,” but rather is required to monitor certain zones, according to the terms of the IHA.

Response: NMFS has revised the IHA to make clear that the requirement to “monitor the project area to the maximum extent possible” does not refer to mitigation clearance zones but is rather a monitoring requirement that applies once operations commence. Specifically, we moved that requirement, which Hilcorp included in its application, to item 5(a) of the IHA, which addresses monitoring requirements during tug operations (in acknowledgement of the fact that Hilcorp will not be able to shut down activities once the tugs are under-load with the jack-up rig). We have also clarified in the final IHA that the maximum extent possible is the maximum distance possible.

The monitoring requirement during operations is distinguished from the mitigation-related pre-clearance zones identified in item 4 of the IHA, which identifies the clearance zones that must be monitored as part of a pre-operational mitigation requirement. See the Mitigation section of this final notice for additional details.

Comment 8: Hilcorp requests that NMFS delete and/or modify language that describes NMFS' purpose and alternatives considered in the agency's Environmental Assessment (EA). Specifically they state that language included in the draft EA incorrectly states NMFS' purpose, and that NMFS does not have the authority to require Hilcorp to use alternative technologies.

Response: NMFS believes the referenced paragraph regarding NMFS' purpose in the EA appropriately describes our intent (which includes evaluating the information in Hilcorp's application). Therefore, NMFS has not deleted the referenced text as requested by Hilcorp. NMFS has revised the language referring to alternatives considered but eliminated from further consideration to clarify that NMFS does not have authority under the MMPA to prescribe that an applicant use alternative technologies to accomplish their objectives ( i.e., an IHA does not authorize an activity, rather take of marine mammals incidental to an activity).

Comment 9: CBD states that NMFS failed to seriously evaluate the assertion that noise from tugboats is the highest noise threat to CIBWs according to NMFS' Recovery Plan for CIBWs (NMFS, 2016).

Response: NMFS' Recovery Plan (NMFS, 2016) ranks noise from tugboats as the most important source that could potentially interfere with CIBW recovery based on signal characteristics and spatio-temporal acoustic footprint. Specifically, NMFS (2016) identified propeller cavitation (the formation of bubbles in a liquid) and engine noise including azimuth/bow thruster noise from tug boats as concerning. However, notably, the Recovery Plan is referencing tugboat noise as a whole across all vessels and the entirety of Cook Inlet, not Hilcorp's specified activity in the specified location and geographic region, which is likely a small portion of overall tugboat use in Cook Inlet throughout the year. The NMFS Alaska Regional Office (AKRO) issued a Biological Opinion on September 4, 2024, under section 7 of the Endangered Species Act (ESA), on the issuance of an IHA to Hilcorp under section 101(a)(5)(D) of the MMPA by the NMFS Office of Protected Resources, which addressed the impacts of the CIBW take NMFS is authorizing in the context of both the environmental baseline and the cumulative effects (including tugboats) and found that it is not likely to jeopardize the continued existence of CIBWs or to destroy or adversely modify their designated Critical Habitat.

NMFS acknowledges that the sounds produced by Hilcorp's tugging activities may potentially result in take, by Level B harassment (behavioral disturbance), of some marine mammals, most likely in the form of avoidance of the vessels and the noise they produce. As described in the Estimated Take section of the notice for the proposed IHA (89 FR 60164, July 24, 2024) and this notice, the sound source levels of tugging activities range widely according to the level of operational effort, with full power output and higher speeds generating more propeller cavitation and hence greater sound source levels than lower power output and lower speeds. As such, Hilcorp will implement mitigation measures intended to reduce the sound source levels from the tugs under load. First, the IHA requires that Hilcorp must conduct tug towing rig operations with a favorable tide unless human safety or equipment integrity are at risk. This is in an effort to reduce the operational effort of the tugs under load and to minimize source levels from Hilcorp's activities. Further, Hilcorp will only use bow thrusters occasionally for a short duration (20 to 30 seconds) to either push or pull a vessel in or away from a dock or platform, and the total tugging activities will be limited to (at most) 6 days of operations out to an estimated maximum distance of 4,453 m around the noise source. Last, the IHA prohibits Hilcorp from initiating tugging activities if a CIBW is observed at any distance within the pre-clearance monitoring period. If a CIBW(s) is observed during those 30 minutes, operations may not commence until the CIBW(s) is no longer detected at any range or 30 minutes have elapsed without any observations of CIBWs. Therefore, NMFS anticipates that Hilcorp would not initiate a tow (which would include the use of bow thrusters) if a CIBW is within the portion of the Level B harassment zone that is closer to the activity, and thus more likely to disturb a CIBW. Lastly, it is important to note that there are multiple contextual factors (including the signal characteristics and the spatio-temporal (space and time) acoustic footprint of Hilcorp's activity as well as bearing and distance, predictability of source movement, and likelihood of habituation to routine vessel traffic) that minimize this potential and the likelihood of behavioral disturbance even if a marine mammal is exposed above the Level B harassment threshold. Based on this analysis, NMFS has made the determinations required by the MMPA and authorized take accordingly.

Comment 10: CBD asserts that NMFS should defer issuance of incidental take of CIBWs unless and until NMFS has a better understanding of the reasons the species is failing to recover. They state that until it does so, NMFS has no rational basis for concluding that any amount of take constitutes a “negligible impact” to the species. Cook Inletkeeper also comments that NMFS should not authorize any take of CIBWs due to uncertainty regarding trends in their population and the impacts that anthropogenic noise may have on this species.

Response: NMFS shares the commenter's concern regarding the impacts of human activities on CIBWs and is committed to supporting the conservation and recovery of the species. Under section 101(a)(5)(D) of the MMPA, NMFS considers the at-risk status of CIBWs (and other species) in both the negligible impact analysis and through our consideration of impact minimization measures that support the least practicable adverse impact on those species. For example, the IHA includes a requirement for Hilcorp to delay the commencement of tugging activities should CIBWs be observed at any distance during the pre-clearance monitoring period and requires that tug operations occur with favorable tides. However, section 101(a)(5)(D) also mandates that NMFS “shall issue” an IHA, provided the necessary findings are made for the specified activity for which incidental take is requested.

In accordance with our implementing regulations at 50 CFR 216.104(c), we use the best available scientific evidence to determine whether the taking by the specified activity within the specified geographic region will have a negligible impact on the species or stock and will not have an unmitigable adverse impact on the availability of such species or stock for subsistence uses. Based on the scientific evidence available, NMFS determined that the take, by Level B harassment only, incidental to Hilcorp's tugging of the jack-up rig, which is primarily acoustic in nature, transient, and of a low level, would have a negligible impact on CIBWs. Moreover, Hilcorp proposed and NMFS has required in the IHA a rigorous mitigation plan to further reduce potential impacts to CIBWs (and other marine mammal species/stocks) to the lowest level practicable. Additionally, the ESA Biological Opinion determined that the issuance of the IHA is not likely to jeopardize the continued existence of CIBWs, the Mexico Distinct Population Segment (DPS) of humpback whales, the Western DPS of Steller sea lions, and the Northeast Pacific stock of fin whales, or to destroy or adversely modify CIBW critical habitat. The Biological Opinion also outlined Terms and Conditions and Reasonable and Prudent Measures to reduce impacts, which have been incorporated into the IHA. Therefore, based on the analysis of potential effects, the parameters of the activity, and the rigorous mitigation and monitoring program, NMFS determined that the taking from the specified activity would have a negligible impact on the CIBW stock.

Cook Inletkeeper stated that recent changes in survey methods calls into question the reliability of using the most recent aerial survey data to identify trends in population status, and that based upon this potential uncertainty and the impact that anthropogenic noise may have on this species, NMFS should not authorize any take of CIBWs. Cook Inletkeeper is incorrect in that survey methods for detecting trends in CIBW population have changed; the survey field methods are essentially unchanged since 2004 (Paul Wade, personal communication, December 11, 2023). The analysis methods used to detect trends in the CIBW population have been updated and implemented in recent studies examining the CIBW population, notably Sheldon and Wade (2019) and Goetz et al. (2023).

Results of recent studies provide evidence that the CIBW population increased between 2004 and 2010, declined after 2010, and increased again from 2016 to 2022 (Jacobsen et al., 2020; Shelden and Wade, 2019; Warlick et al., 2023; Goetz et al., 2023). While there is some uncertainty around CIBW population trend analyses, the results of these four studies are consistent in showing general trends. Thus, while Cook Inletkeeper is correct that some studies confirm a declining trend in CIBW abundance, recent studies, which NMFS considers the best scientific information available, suggest the population may now be increasing (see Goetz et al., 2023). Additional data in the coming years will help to inform whether the recent positive trend in the CIBW population will continue.

Beyond the requirements in this IHA to minimize the impact of any taking from Hilcorp's activity, NMFS is taking several proactive steps to help protect and better understand the species. For example, NMFS is supporting the development of a population consequences of disturbance (PCoD) model, currently being developed by NMFS researchers, to quantitatively assess the degree to which anthropogenic disturbance, and in particular noise, may impact survival and reproduction of CIBWs. Results of Phase 1 of the model were published in 2023 (McHuron et al., 2023) and the Phase 2 analysis is underway. NMFS also continues to conduct outreach and education to various stakeholders to minimize the potential for unauthorized take of CIBWs. NMFS also issued Cook Inlet and Kodiak Marine Mammal Disaster Response Guidelines in 2019 (NMFS, 2019b) and a stranding response plan specific to CIBWs in 2009 (NMFS, 2009), which could inform responses and further reduce impacts to CIBWs. NMFS initiated efforts to update the 2009 stranding response plan in 2021, and those efforts are ongoing. For more information, see NMFS' 5-year Priority Action Plan (2021-2025) for CIBWs as part of its Species in the Spotlight initiative to provide immediate, targeted efforts to halt declines and stabilize populations of the species most at-risk of extinction in the near future (see https://www.fisheries.noaa.gov/resource/document/species-spotlight-priority-actions-2021-2025-cook-inlet-beluga-whale ).

Comment 11: CBD and Cook Inletkeeper comment that NMFS cannot issue “Renewed” IHAs under the MMPA. CBD further comments that NMFS cannot issue “successive” IHAs without a comprehensive analysis and must analyze and mitigate the total take it is proposing to authorize across all two years. CBD states that the 15-day comment period proposed for renewals is also unlawful and places a burden on interested members of the public to review not only the original authorization and supporting documents but also the draft monitoring reports, the renewal request, and the proposed renewed authorization and then to formulate comments, all within 15 calendar days. They assert that NMFS should set forth, via proposed regulation or policy document, its rationale for the Renewal process and to allow public comment.

Response: The process of issuing a renewal IHA does not bypass the public notice and comment requirements of the MMPA. The notice of the proposed IHA initiated a 30-day public comment period and expressly notifies the public that under certain, limited conditions an applicant could seek a renewal IHA for an additional year. The notice describes the conditions under which such a renewal request could be considered and expressly seeks public comment in the event such a renewal is sought. Importantly, any such renewals (if issued) would be limited to where the activities are identical or nearly identical to those analyzed in the proposed IHA, monitoring does not indicate impacts that were not previously analyzed and authorized, and the mitigation and monitoring requirements remain the same, all of which allow the public to comment on the appropriateness and effects of a renewal at the same time the public provides comments on the initial IHA.

Importantly, renewal IHAs are evaluated by NMFS on a case-by-case basis and are not an automatic matter of right. Each 1-year IHA must independently satisfy the negligible impact standard for the authorized taking and include the means of effecting the least practicable adverse impact on the species or stock and its habitat and, where relevant, on the availability of such species or stock for taking for subsistence uses ( i.e., mitigation). Moreover, NMFS is not proposing to issue a “successive” IHA for a second year. For these reasons a comprehensive analysis of the impacts of potential take across two years is not appropriate under the MMPA. Any renewal request would be evaluated under the appropriate statutes ( e.g., MMPA, National Environmental Policy Act (EPA), and ESA) for compliance with relevant standards. These analyses would consider the environmental baseline at that time, including any impacts of the IHA we have issued.

Should a renewal request be made, additional documentation would be required from Hilcorp that NMFS would make publicly available and would use to verify that the activities are identical to those in the initial IHA, are nearly identical such that the changes would have either no effect on impacts to marine mammals or decrease those impacts, or are a subset of activities already analyzed and authorized but not completed under the initial IHA. NMFS would also confirm, among other things, that the activities would occur in the same location; involve the same species and stocks; provide for continuation of the same mitigation, monitoring, and reporting requirements; and that no new information had been received that would alter the prior analysis. If new information has been received that would alter the prior analysis, that information would be analyzed in the notice of the proposed renewal IHA. A renewal request would also contain a preliminary monitoring report, specifically to verify that effects from the activities do not indicate impacts of a scale or nature not previously analyzed. Any renewal request is subject to an additional 15-day public comment period that provides the public an opportunity to review these few documents, provide any additional pertinent information and comment on whether they think the criteria for a renewal have been met. Between the initial 30-day comment period on these same activities and the additional 15 days, the total comment period for a Renewal is 45 days.

In addition to the IHA renewal process being consistent with all requirements under section 101(a)(5)(D), it is also consistent with Congress' intent for issuance of IHAs to the extent reflected in statements in the legislative history of the MMPA. Through the provision for renewals in the implementing regulations, description of the process and express invitation to comment on specific potential renewals in the Request for Public Comments section of each proposed IHA, the description of the process on NMFS' website, further elaboration on the process through responses to comments such as these, posting of substantive documents on the agency's website, and provision of 30 or 45 days for public review and comment on all proposed initial IHAs and renewals respectively, NMFS has ensured that the public has full opportunity to meaningfully participate in the agency's decision-making process.

Comment 12: CBD states that NMFS' small numbers determination is arbitrary, unlawful, unreasonable, and improper. They comment that NMFS' determination is based on a patently unlawful interpretation of what constitutes a small number and fails to consider that even a relatively small number of takes of critical endangered CIBWs can be more than small considering the species' highly imperiled status.

In support of NMFS' small numbers determination, Hilcorp recommends that NMFS expressly reference the Federal Register notice where the standard for small numbers is identified and fully explained, include that reference in the record, and summarize that explanation in this final notice of IHA issuance. They also request that NMFS clearly express its finding that the proposed incidental harassment levels constitutes a “small number” for each marine mammal stock, independent of NMFS's “one-third” standard.

Response: Our notice of the proposed IHA referenced an earlier rulemaking in which we provided a full explanation of the agency's interpretation of “small numbers.” (86 FR 5322, 5438, January 19, 2021). NMFS makes its small numbers findings based on an analysis of whether the number of individuals authorized to be taken annually from a specified activity is small relative to the stock or population size. This relative approach is consistent with the statement from the legislative history that “[small numbers] is not capable of being expressed in absolute numerical limits” (H.R. Rep. No. 97-228, at 19 (September 16, 1981)), and relevant case law ( Center for Biological Diversity v. Salazar, 695 F.3d 893, 907 (9th Cir. 2012) (holding that the U.S. Fish and Wildlife Service reasonably interpreted “small numbers” by analyzing take in relative or proportional terms)). Using such a simple approach that establishes equal bins corresponding to small, medium, and large proportions of the population abundance, when the predicted number of individuals to be taken is fewer than one-third of the species or stock abundance, the take is considered to be of small numbers. (86 FR 5322, 5438, January 19, 2021).

As described in the Small Numbers section of the Federal Register notice of the proposed IHA (89 FR 60164, July 24, 2024) and this notice of issuance, NMFS is authorizing take of less than 2 percent for all stocks, except for CIBWs whose authorized take is 5.38 percent of the stock; see tables 12 and 11 in the notice for the proposed IHA (89 FR 60164, July 24, 2024) and this notice, respectively). Here, NMFS finds the taking of 5.38 percent of CIBWs, and 2 percent of other 14 other stocks of marine mammals constitutes small numbers of marine mammals taken relative to the population size of the affected species or stocks. As Hilcorp's comment letter points out, these percentages also fall under the amount upheld as small numbers by the U.S. District Court for the District of Alaska in Native Village of Chickaloon v. NMFS, 947 F. Supp. 2d 1031 (D. Alaska 2013) (concluding that NMFS' authorization of 10 percent of CIBWs constituted small numbers relative to the affected population size). This is well below NMFS' upper limit of one-third as described above. Further, using the take numbers (which actually represent instances of take) to compare to the population abundance conservatively assumes (for small numbers purposes) that each take represents a different individual (rather than a few individuals experiencing multiple instances of take). Therefore, NMFS has deemed the taking to be of small numbers of marine mammals (relative to the relevant species or stock abundances).

Finally, we disagree with CBD's assertion that NMFS' small number determination for CIBWs should consider the highly imperiled status of the species. The argument to establish a small numbers threshold on the basis of stock-specific context is unnecessarily duplicative of the required negligible impact finding, in which relevant biological and contextual factors are considered in conjunction with the amount of take, and would risk conflating the two standards. See Ctr. for Biological Diversity v. Salazar, 695 F.3d at 907 (cautioning the U.S. Fish and Wildlife Service to “keep[] the standards distinct”).

Comment 13: CBD comments that NMFS' negligible impact determination is improper and arbitrary. They state that it overlooks that CIBWs are among the most highly endangered animals under the agency's jurisdiction to protect. They state that NMFS has no rational basis for concluding that additional harassment by noise has a negligible impact on the species.

Response: NMFS disagrees with the comment. In the Negligible Impact Analysis and Determination section of the notice of the proposed IHA (89 FR 60164, July 24, 2024) and again in this notice, we describe how the take estimated and authorized for Hilcorp's tugging activity will have a negligible impact on all of the affected species or stocks, including CIBWs. We discuss how this determination is based upon, among other things, the low number of takes of each stock that might be exposed briefly during 6 days of activity over the course of the 1-year IHA, the comparatively low level of behavioral harassment that might result from an instance of take that could occur within that year, and the likelihood that the mitigation measures required further lessen the likelihood, magnitude, or severity of exposures. NMFS also considered the status of each stock in its analysis.

NMFS' negligible impact finding considers a number of parameters including, but not limited to, the nature of the activities ( e.g., duration, sound source), effects/intensity of the taking, the context of takes, and mitigation. For CIBWs, NMFS considered data from previous similar tugging activities. Hilcorp's most recent annual marine mammal monitoring report indicates that it did not record any sightings of CIBWs from their rig-based monitoring efforts (Horsley and Larson, 2023), and the most recent monthly monitoring report that describes monitoring results from the May 2024 rig transiting also indicates no recorded sightings of CIBWs during transit (Weston Solutions, 2024). Any disturbance that may occur is anticipated to be limited to behavioral changes such as increased swim speeds, changes in diving and surfacing behaviors, and alterations to communication signals, not the loss of foraging capabilities or the abandonment of critical habitat. Given these anticipated impacts, none of which would be expected to impact the fitness or reproduction of any individual marine mammals, much less adversely impact annual rates of recruitment or survival of CIBWs, NMFS' independent evaluation of the best scientific evidence in this case supports our negligible impact determination. Further, the ESA Biological Opinion concluded that the proposed action is not likely to jeopardize the continued existence of CIBWs or to destroy or adversely modify designated CIBW critical habitat.

Comment 14: CBD asserts that NMFS discounts the best available science for CIBWs. CBD claims that NMFS incorrectly stated that CIBWs are not known to engage in critical behaviors in the area where Hilcorp's project is planned.

Response: NMFS acknowledges observation of two potential but unconfirmed incidences of mating behavior in the Trading Bay area in 2014, but the extent to which critical behaviors occur in Hilcorp's project area is still unknown (Lomac-Macnair et al., 2016). Such behaviors have not been reported since. Surveys by NMFS or McGuire et al. (2020) with concentrated effort on the western coast of Cook Inlet have not yielded a comparable sighting. Other key behaviors, such as calving and feeding, are described in more detail below but are thought to occur primarily in other concentrated areas outside of Hilcorp's action area.

We are unaware of any information regarding areas where CIBWs are more likely to engage in mating behavior, however, what is known about calving suggests that it is most concentrated in the upper Inlet, north of Hilcorp's project area. McGuire et al. (2020) characterizes habitat use by age class in northern Cook Inlet and documented the majority of calves in the northernmost parts of Cook Inlet ( e.g., Susitna Delta) despite concentrated survey effort in areas along the west part of the Inlet heading south toward the Forelands. NMFS acknowledges that CIBWs use the area, especially in spring and fall months, but their habitat range at those times is not nearly as constricted as their summer habitat, which is concentrated in a small area with high anthropogenic activity.

CIBWs may well occur in the project area, which is why a small amount of take by Level B harassment is authorized for this species incidental to Hilcorp's jack-up rig towing. Tagging data, acoustic studies, and opportunistic sightings indicate that CIBWs continue to occur in the upper inlet throughout the winter months, in particular the coastal areas from Trading Bay to Little Susitna River, with foraging behavior detected in lower Knik Arm and Chickaloon Bay, and also detected in several areas of the lower inlet such as the Kenai River, Tuxedni Bay, Big River, and NW Kalgin Island ( e.g., Castellote et al., 2020, 2021; C. Garner, pers. comm.; Shelden et al., 2015a, 2018). CIBWs were historically seen in and around the Kenai and Kasilof rivers during June aerial surveys conducted by ADFG in the late 1970s and early 1980s and by NMFS starting in 1993 (Shelden et al., 2015b), and throughout the summer by other researchers and local observers. In recent years, sightings in and near these rivers have been more typical in the spring and fall (Ovitz, 2019). It is unknown if this is due to increased monitoring efforts in the area or an increase in CIBWs using this area. While visual sightings indicate peaks in spring and fall, acoustic detections indicate that CIBWs can be present in the Kenai River throughout the winter (Castellote et al., 2016). Despite the historic sightings (1970s-1990s) of CIBWs throughout the summer (June-August) in the area, recent acoustic detections and visual sightings indicate that there appears to be a steep decline in CIBWs presence in the Kenai River during the summer, despite an annual return in recent years of 1-1.8 million sockeye salmon, which are important CIBW prey. Further, while feeding behaviors may occur in Hilcorp's project area, there are no known foraging hot spots near the project area. CIBWs are expected to be transiting through the area, headed to or from the concentrated foraging areas farther north near the Beluga River, Susitna Delta, and Knik and Turnigan Arms. Therefore, any exposures are likely to be limited in duration during the 6 days of tugging activity and would take place in a small portion of available foraging habitat. Any impacts on feeding are expected to be minimal.

As described above, we have no reason to expect CIBWs to be concentrated in the path of Hilcorp's tug boats for the purposes of reproductive or feeding behaviors, but even if one or more of the 15 instances in which noise from tugboat operations briefly intersects with an individual CIBW engaged in these behaviors, the anticipated short duration and low level disturbance of any such encounter would not be likely to impact reproductive or foraging success of any individuals.

The commenter further asserts that NMFS' negligible impact conclusion is particularly arbitrary considering the project will occur within a year-round Biologically Important Area (BIA) for CIBWs and also in CIWB critical habitat. While exposure to elevated noise levels associated with Hilcorp's activities may result in low-level behavioral changes in marine mammals, NMFS' review of the best available scientific evidence, as summarized and cited herein, demonstrates that these responses do not rise to the level of having adverse effects on the reproduction or survival of any marine mammals, much less on rates of recruitment or survival of any species or stock, and the commenter has provided no evidence to the contrary. Further, while Hilcorp's project area does overlap ESA-designated critical habitat for CIBWs and the CIBW small and resident BIA (Wild et al., 2023), the impacts from the project are not expected to occur in areas that are specifically important for feeding or reproduction for any species, including CIBWs, nor are they anticipated to result in a loss of prey or habitat. Monitoring data from Hilcorp's past activities suggest that tugging activities do not discourage CIBWs from transiting throughout Cook Inlet and between critical habitat areas and that the whales do not abandon critical habitat areas (Horsley and Larson, 2023). In addition, large numbers of CIBWs have continued to use Cook Inlet and pass through the area, likely traveling to critical foraging grounds found in upper Cook Inlet ( i.e., outside of the project area), while noise-producing anthropogenic activities, including vessel use, have taken place during the past two decades ( e.g., Shelden et al., 2013, 2015b, 2017, 2022; Shelden and Wade, 2019; Geotz et al., 2023).

Comment 15: CBD asserts that NMFS negligible impact determination for all species relies on mitigation measures that rely nearly exclusively on visual monitoring measures that it claims are “known to be ineffective and inadequate” to protect marine mammals.

Response: NMFS disagrees with the comment. Our discussion in the Negligible Impact Analysis and Determination section below contains the factors NMFS considered in reaching its negligible impact determinations. Although NMFS' implementing regulations at 50 CFR 216.104(c) state that NMFS may incorporate successful implementation of mitigation measures to arrive at a negligible impact determination, for issuance of the IHA for Hilcorp's tug towing activities, NMFS did not rely upon an assumption of set level of effectiveness in mitigation to make our negligible impact determinations. While NMFS acknowledges that visual observations can be difficult in Cook Inlet due to the extreme tidal range, harsh weather, turbid waters, and seasonal ice presence ( e.g., Castellote et al., 2020; Lammers et al., 2013), prior monitoring efforts by Hilcorp have shown that it is clearly possible to detect and identify marine mammals to the species several km away from the source, including CIBWs, acknowledging that visibility depends on several factors such as visual acuity, sea state, glare, light, animal behavior/body type, speed of travel for vessel and animal, etc. (Horsley and Larson, 2023). NMFS does not assume total effectiveness of monitoring, but the demonstrated record of PSO sightings for activities in Cook Inlet illustrate that visual monitoring is appropriate for implementing mitigation in this case.

Comment 16: CBD and Cook Inletkeeper comment that NMFS fails to ensure the least practicable adverse impact on CIBWs, the other species or stocks to be taken, and their habitats because NMFS failed to consider requiring several practicable mitigation measures, such as the use of passive acoustic monitors (PAM) and drones to help detect the presence of marine mammals, time-area restrictions, and requiring the use of noise-quieting engines. Cook Inletkeeper recommended that NMFS should require improved look-outs for marine mammals and additional monitoring.

Response: We disagree with the commenter's claims. NMFS has included measures designed to effect the least practicable adverse impact on marine mammals species and their habitat, and has also included appropriate monitoring and reporting requirements. For example, during tugging activities, Hilcorp must conduct pre-clearance monitoring prior to commencing activities and must delay the start of activities if marine mammals are within designated pre-clearance zones (1,500 m for non-CIBW species and at any distance for CIBWs). Hilcorp must also conduct tugging activities with a favorable tide to reduce noise output. Please see the Mitigation section of this notice for a full description of the required mitigation measures.

The CBD states that NMFS should require PAM for marine mammals. The use of PAM for real-time mitigation purposes has been used in Cook Inlet for some studies. These efforts have generally not resulted in successful deployment of PAM or useful detections of marine mammals to inform mitigation and monitoring during the activities due to the environmental conditions of the region (Austin and Zeddies, 2012; Kendall et al., 2015). For example, background acoustic conditions, including flow noise from strong currents, large tidal changes, and weather along with additional noise from the project ( e.g., vessel noise, noise from project equipment) made it difficult to detect marine mammals from a real-time PAM system implemented as part of the 2012 Apache 3D seismic survey program in lower- and mid-Cook Inlet (Austin and Zeddies, 2012; Lomac-MacNair et al., 2013) and during the 2015 SAExploration Cook Inlet 3D seismic survey program (Kendall et al., 2015). Further, environmental conditions restricted the type of PAM systems that could be deployed during these programs to a single omni-directional hydrophone lowered from the side of a vessel, which restricted the possible range of detections. These factors suggest that effective PAM monitoring in Cook Inlet can be challenging (Austin and Zeddies, 2012).

As CBD notes, academic researchers have begun to implement more effective passive acoustic monitors for research purposes at several places in Cook Inlet ( e.g., Lammers et al., 2013 and Castellote et al., 2020 as cited by CBD). However, the framework used by those researchers is not practicable for Hilcorp's planned activity. An article on NOAA's website ( https://www.fisheries.noaa.gov/science-blog/beluga-whale-acoustic-monitoring-survey-post-3 ) illustrates the level of customization, expertise, and difficulty required to assemble a passive acoustic mooring to then deploy in the Inlet. Additionally, these instruments are stationary, which means to effectively use these monitors as a means of avoiding harassment of marine mammals during Hilcorp's tugging activities, Hilcorp would need to build and successfully deploy dozens (or more) stationary monitors along a route of travel that is subject to change depending upon weather or other environmental and shipping restrictions. Additionally, the data stored on these types of moorings is not accessible until they are retrieved by the researcher who deployed them. In the future, if an established network of passive acoustic monitors with shared access to the data is available, this could be a useful tool for implementing mitigation measures, but is currently not practicable.

Contrary to CBD's assertion, NMFS did consider a time-area restriction; both the IHA and resulting ESA Biological Opinion require that Hilcorp maintain a distance of at least 2.4 km from the mean lower-low water line of the Susitna River Delta (Beluga River to the Little Susitna River) between April 15 and November 15, as this is an area where CIBWs can aggregate for feeding. CBD suggested further restrictions could include, for example, a prohibition on activities in April and May at Trading Bay where and when CIBWs have been observed engaged in probable mating behavior (Lomac-MacNair et al., 2016); or a prohibition on activities from July through September when CIBWs have been observed feeding in the area. Hilcorp's activity in Trading Bay would be either a single day of transit or several hours of positioning the jack-up rig at an existing well site. As discussed in our above comment response, there has been one published observation of potential (not confirmed) mating behavior of CIBWs in Trading Bay in 2014. Surveys by NMFS or McGuire et al. (2020) with concentrated effort on the western coast of Cook Inlet have not yielded a comparable sighting. Closure of the entire area for two months is not practicable as Hilcorp would not be able to access the well sites that are part of the intended activity. As discussed above and in the species-specific section of the proposed IHA, CIBWs are highly concentrated in the upper Cook Inlet especially in the summer months (Goetz et al., 2012; McGuire et al., 2020). In the past, CIBWs used the Kenai area in summer months but that trend has shifted in recent decades to occasional spring and fall sightings (Ovitz, 2019). Throughout the Inlet, mean group sizes during the summer and fall were largest in July and smallest in October, with the largest groups seen during mid-July and early August in the Susitna River Delta, while the smallest group sizes were in the Kenai River Delta. These patterns of high seasonal concentrations have continued to be documented since 2012 ( e.g., McGuire et al., 2020). In reflection of this information, NMFS, as described above, has imposed time area restrictions in the Susitna River Delta from April to November to reduce effects of Hilcorp's activity to the greatest extent practicable. A closure in the middle Inlet during the summer months, in the season with longest daylight hours and best conditions for visual observations to implement mitigation and monitoring, is not warranted under the least practicable adverse impact standard.

CBD states that NMFS failed to consider requiring noise-quieting engines, such as electric tugboats, which would have the added benefit of reducing air pollution and greenhouse gas emissions from tugs. NMFS is not aware of any commercially available seaworthy tug vessels that are used in tandem ( e.g., three tug configuration) with effective quieting technologies or of any company or entity with electric tug fleets able to use them in tandem as required for Hilcorp's activities. The eWolf, and electronic tug boat, was christened in San Francisco Bay in June 2024 and was the first of its kind in U.S. waters. NMFS is also not aware of alternative technologies available that would allow Hilcorp to move the jack-up rig to various well sites without generating noise, which is the primary activity that has the potential to take marine mammals by harassment. Further, as described in our response to Comment 8, NMFS does not have the authority under the MMPA or ESA to prescribe that an applicant use alternative technologies to accomplish their objectives.

CBD also commented that NMFS failed to consider an alternative that would require the use of drones, in addition to PSOs, to detect the presence of marine mammals. Cook Inletkeeper similarly suggested that NMFS should require a combination of drone and visual monitoring at all times. While unmanned aerial vehicles (UAVs; i.e., drones) have been used in some instances to observe marine mammals, there are logistical reasons (including limited berthing availability) that this measure is not practicable for Hilcorp to implement for this project. For these reasons, NMFS has not required that Hilcorp use drones or other UASs to assist in detecting marine mammals during their planned tugging activities.

CBD correctly notes that the 1,500 m pre-clearance zone for non-CIBWs is smaller than the Level B harassment zone (≤4,453 m). However, as mentioned in the response to Comment 7 above, NMFS has prescribed a requirement for this IHA (not included in previous IHAs issued to Hilcorp for take of marine mammals incidental to tugging activities; 87 FR 62364, October 14, 2022) that Hilcorp establish a pre-clearance zone whereby they delay new operational activities should CIBWs be observed at any distance. This measure provides additional protection for CIBWs by further limiting the potential that tugging activities will commence while CIBWs are nearby. Further, using the Level B harassment zone as the clearance zone would not be practicable for some non-CIBW species ( e.g., pinnipeds, harbor species) whose smaller size and often cryptic behavior may make accurate identification difficult at greater distances in Cook Inlet's environmental conditions. While underway, PSOs will observe for marine mammals to the greatest distance possible (they are not limited to observing within 1,500 m of the vessel). Any marine mammal sighted by PSOs at any distance is noted and reported to NMFS, per the reporting requirements of the IHAs.

Cook Inletkeeper recommended that NMFS require improved look-outs ( i.e., additional observers) and additional monitoring to better inform about the marine mammal populations and distributions as well as impacts from the proposed activities to better inform future activities. Hilcorp has informed NMFS that stationing additional PSOs on the tug boats or jack-up rig is not a practicable option for this project due to the limited berthing areas on the vessels. Cook Inletkeeper did not provide any recommendations for what additional monitoring would entail; however, the IHA does require that Hilcorp monitor and carefully record all observations of marine mammals, regardless of distance from the activity, as well as additional data such the group composition of any species observations, their distance and bearing from the source, their closest approach and time spent in estimated harassment zones, and any behavioral observations, including an assessment of behavioral responses thought to have resulted from the tugging activities. This information will be used to inform any future decisions regarding the issuance of IHAs for tugging activities, similarly as details documented by Hilcorp in their reports ( e.g., Horsley and Larson, 2023) informed the decisions made herein.

Lastly, Cook Inletkeeper recommended that NMFS not permit tug towing rig activities during periods of low visibility or at night, even to accommodate a favorable tide. Hilcorp's ability to move the jack-up rig is limited by several factors, including the presence of favorable environmental conditions for safe operations, crew availability, and the availability of the tug boats, which is limited by other scheduled work. Hilcorp must balance these factors with the timing of their planned actions. Despite this, Hilcorp will only begin operations in low light or night conditions if necessary for safety purposes ( e.g., incoming inclement weather or ice) or to accommodate a favorable tide. Tugs may work at up to 80 percent power for much longer durations of time when pulling against the strong tides in Cook Inlet. As sound is the primary potential stressor from the proposed activity, limiting the sound output is preferred and tugs moving with the tide will reduce engine load by as much as 60 percent. Additionally, limited daylight, particularly in the shoulder seasons, results in at least a portion of activity occurring in low light or night conditions. As the ice-free season is already limited to roughly half the year, in order to maximize the ice-free season, operations in low-light or night conditions may be necessary. To mitigate this and enhance PSO's visibility, PSOs are required to use NMFS-approved night vision devices (NVDs) ( e.g., PVS-7s, or equivalent) and have magnifying lenses available for use.

Comment 17: Cook Inletkeeper asserts that NMFS must consider whether the cumulative impacts from Hilcorp's proposed activities in Cook Inlet will have a negligible impact on the area's marine mammals. Specifically, NMFS must consider the cumulative impacts of noise in Cook Inlet, including noise impacts from vessels and nearby construction, and determine what activities or combinations of activities would exceed a cumulative negligible impact threshold. Cook Inletkeeper urges NMFS to perform such an analysis before authorizing any ITAs for take of CIBWs.

Response: Neither the MMPA nor NMFS' codified implementing regulations call for consideration of the take resulting from other activities in the negligible impact analysis. The preamble for NMFS' implementing regulations (54 FR 40338, September 29, 1989) states, in response to comments, that the impacts from other past and ongoing anthropogenic activities are to be incorporated into the negligible impact analysis via their impacts on the baseline. Consistent with that direction, NMFS has factored into its negligible impact analysis the impacts of other past and ongoing anthropogenic activities via their impacts on the baseline ( e.g., as reflected in the density/distribution and status of the species, population size and growth rate, and other relevant stressors (such as incidental mortality in commercial fisheries, Unusual Mortality Events (UMEs), and subsistence hunting); see the Negligible Impact Analyses and Determinations section of this notice of issuance). The 1989 final rule for the MMPA implementing regulations also addressed public comments regarding cumulative effects from future, unrelated activities. There, NMFS stated that such effects are not considered in making findings under section 101(a)(5) concerning negligible impact. In this case, this IHA as well as other incidental take authorizations (ITAs) currently in effect or proposed within the specified geographic region, are appropriately considered an unrelated activity relative to the others. The ITAs are unrelated in the sense that they are discrete actions under section 101(a)(5)(D) issued to discrete applicants.

Through the response to public comments in the 1989 implementing regulations, NMFS also indicated (1) that we would consider cumulative effects that are reasonably foreseeable when preparing a National Environmental Policy Act (NEPA) analysis, and (2) that reasonably foreseeable cumulative effects would also be considered under section 7 of the Endangered Species Act (ESA) for ESA-listed species, as appropriate. Accordingly, NMFS has prepared an EA that considers cumulative effects. Additionally, under the ESA, NMFS' Biological Opinion independently considered the reasonably foreseeable cumulative effects of activities on ESA-listed species.

Comment 18: Cook Inletkeeper raises concerns with Hilcorp's record of safety and environmental compliance. They state that according to the Alaska Oil and Gas Conservation Commission (AOGCC), Hilcorp has a documented pattern of accidents and safety violations and disregard for compliance with the law in Alaska. They assert that NMFS must consider Hilcorp's record and provide rigorous oversight.

Response: It is the responsibility of the applicants to comply with all applicable laws and regulations, and to work with the state to obtain approval of their Oil Discharge Prevention and Contingency Plans (ODPCP). Hilcorp complied with the mitigation, monitoring, and reporting requirements of previously issued LOAs and IHAs under the MMPA (Fairweather Science, LLC, 2020; Korsmo et al., 2022; Horsley and Larson, 2023; Weston Solutions, 2024), thus we have no reason to believe that the requirements of the current IHA will not be upheld.

Changes From the Proposed IHA to Final IHA

There are no changes from the proposed IHA to the final IHA other than the addition of some clarifying language and some minor typographical corrections.

Description of Marine Mammals in the Area of Specified Activities

Sections 3 and 4 of the application summarize available information regarding status and trends, distribution and habitat preferences, and behavior and life history of the potentially affected species. NMFS fully considered all of this information, and we refer the reader to these descriptions, instead of reprinting the information. Additional information regarding population trends and threats may be found in NMFS' Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments ) and more general information about these species ( e.g., physical and behavioral descriptions) may be found on NMFS' website ( https://www.fisheries.noaa.gov/find-species ).

Table 1 lists all species or stocks for which take is expected and authorized for this activity and summarizes information related to the population or stock, including regulatory status under the MMPA and ESA and potential biological removal (PBR), where known. PBR is defined by the MMPA as the maximum number of animals, not including natural mortalities, that may be removed from a marine mammal stock while allowing that stock to reach or maintain its optimum sustainable population (as described in NMFS' SARs). While no serious injury or mortality is anticipated or authorized here, PBR and annual serious injury and mortality from anthropogenic sources are included in table 1 as gross indicators of the status of the species or stocks and other threats.

Marine mammal abundance estimates presented in this document represent the total number of individuals that make up a given stock or the total number estimated within a particular study or survey area. NMFS' stock abundance estimates for most species represent the total estimate of individuals within the geographic area, if known, that comprises that stock. For some species, this geographic area may extend beyond U.S. waters. All managed stocks in this region are assessed in NMFS' U.S. 2022 SARs. All values presented in table 1 are the most recent available at the time of publication (including from the draft 2023 SARs) and are available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.