Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Narwhal, LLC Oil and Gas Exploration Activities in West Harrison Bay, Alaska

<NOTICE> DEPARTMENT OF COMMERCE <SUBAGY>National Oceanic and Atmospheric Administration</SUBAGY> <DEPDOC>[RTID 0648-XE957]</DEPDOC> <SUBJECT>Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Narwhal, LLC Oil and Gas Exploration Activities in West Harrison Bay, Alaska</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce. <HD SOURCE="HED">ACTION:</HD> Notice; issuance of an incidental harassment authorization. <SUM> <HD SOURCE="HED">SUMMARY:</HD> Notification is hereby given that NMFS has issued an incidental harassment authorization (IHA) to Narwhal, LLC (Narwhal) to incidentally take by harassment marine mammals during oil and gas exploration activities in west Harrison Bay, Alaska. </SUM> <DATES> <HD SOURCE="HED">DATES:</HD> This authorization is effective for one year from the date of notification by the IHA-holder, not to exceed one year from the date of issuance (August 12, 2025). </DATES> <HD SOURCE="HED">ADDRESSES:</HD> Electronic copies of the application, IHA, and supporting documents, as well as a list of the references cited in this document, may be obtained online at: <E T="03">https://www.fisheries.noaa.gov/action/incidental-take-authorization-narwhal-llcs-oil-and-gas-exploration-activities-west-harrison.</E> In case of problems accessing these documents, please contact the contact listed below. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Craig Cockrell, Office of Protected Resources, NMFS, (301) 427-8401. </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Background</HD> The MMPA prohibits the “take” of marine mammals, with certain exceptions. Section 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 <E T="03">et seq.</E> ) directs 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 mitigation, monitoring and reporting of the takings are set forth. The definitions of all applicable MMPA statutory terms cited above are included in the relevant sections below. <HD SOURCE="HD1">Summary of Request</HD> On October 25, 2022, NMFS received a request from Narwhal for an IHA to take marine mammals incidental to oil and gas exploration activities in and around west Harrison Bay, Alaska. Narwhal withdrew the original request and then resubmitted an application on November 1, 2024. The application was deemed adequate and complete on January 27, 2025. Narwhal's request is for take of four marine mammal species, by Level B harassment only. Neither Narwhal nor NMFS expect serious injury or mortality to result from the specified activity, and therefore, an IHA is appropriate. <HD SOURCE="HD1">Description of Activity</HD> <HD SOURCE="HD2">Overview</HD> Narwhal proposes to conduct oil and gas exploration activities, including shallow hazard geophysical surveys, exploratory drilling operations, and associated construction and operation of ice trails, roads, and pads, in west Harrison Bay, Alaska. The activities are planned to occur between August 2025 and July 2026 and will occur primarily in west Harrison Bay and the area between west Harrison Bay and Prudhoe Bay, Alaska. Narwhal will also conduct mobilization and barge transport activities out of Prudhoe Bay, Alaska. Shallow hazard geophysical surveys (hereinafter, “shallow water hazard surveys”) will use airguns and sparkers as acoustic sources and would introduce underwater sound that may result in take by Level B harassment of marine mammals. Construction and operation of sea ice trails around the Colville River Delta may result in take by Level B harassment of ringed seals due visual disturbance. Shallow hazard surveys at all six sites will take place over approximately 12 days and will occur over a 12-hour period each day. Offshore ice road and trail construction will occur over approximately 167 days and will occur as needed throughout a 24-hour period. A number of other activities will occur during the course of the specified activities, but, they are not expected to result in take of marine mammals. Since publication of the <E T="04">Federal Register</E> notice of the proposed IHA, Narwhal estimates that eight barges may need to be used for option staging activities ( <E T="03">see</E> 90 FR 21182, 21185, May 16, 2025). This minor change to this activity does not change NMFS' determination that this activity is unlikely to result in take of marine mammals. A detailed description of the specified activities is provided in the <E T="04">Federal Register</E> notice for the proposed IHA (90 FR 21182, May 16, 2025). No other changes have been made to the planned activities. Therefore, a detailed description is not provided here. Please refer to that <E T="04">Federal Register</E> notice for the description of the specified activity. <HD SOURCE="HD1">Comments and Responses</HD> A notice of NMFS' proposal to issue an IHA to Narwhal was published in the <E T="04">Federal Register</E> on May 16, 2025 (90 FR 21182). That notice described, in detail, Narwhal's specified activities, 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. NMFS received one substantive comment letter from the Center for Biological Diversity (CBD). Please see CBD's comment letter, available online at <E T="03">https://www.fisheries.noaa.gov/action/incidental-take-authorization-narwhal-llcs-oil-and-gas-exploration-activities-west-harrison,</E> for full detail regarding the comments and associated rationale. The Arctic Peer Review Panel (PRP), convened by NMFS as required under 50 CFR 216.108(d), reviewed the Monitoring Plan (please see the Monitoring Plan Peer Review section, below). We have not responded to comments that failed to raise a significant point for us to consider ( <E T="03">e.g.,</E> comments that are out of scope of the proposed IHA; mitigation, monitoring, or reporting measures already included in the proposed IHA). Furthermore, if a comment received was unclear, NMFS does not include it here as it could not determine whether it raised a significant point for NMFS to consider. <E T="03">Comment 1:</E> The PRP stated that NMFS should require aircraft used by Narwhal to follow flight paths either five miles inland or five miles offshore to minimize impacts to subsistence hunting for marine mammals. <E T="03">Response 1:</E> NMFS disagrees with this recommended mitigation measure. The IHA contains a minimum altitude limit for aircraft to avoid potential disturbance to marine mammals or effects to the availability of marine mammals for subsistence uses. All aircraft must maintain an altitude of 457 meters (m) (1,500 feet (ft)) during flight and if flights must occur below 457 m the flight course must be altered to maintain 457 m of horizontal separation from any marine mammals. The recommended measure is impracticable given the unpredictability of weather conditions and the remote nature of the project area; pilots will fly the most direct path to the aerial survey areas to minimize time in the air but maintain the minimum altitude requirements. Given the low potential for take from this activity and the mitigation measure of 457 m minimum altitude for aircraft, based on the best available scientific information, the likelihood of take by Level B harassment from this activity is discountable. <E T="03">Comment 2:</E> CBD asserted that NMFS did not provide adequate justification to assume that aircraft flights flown at a minimum of 457 m by Narwhal would not result in take of marine mammals and NMFS' determination that no take would result from this activity is inaccurate. <E T="03">Response 2:</E> NMFS disagrees that flights operated at a minimum altitude of 457 m would result in takes of marine mammals. In Narwhal's application, they note that received levels of in-air noise from fixed-wing propeller aircraft sounds ranged from 75 to 90 dB and airborne noise levels from helicopters were 60 to 70 dB at 460 m (1509 ft.) (Richardson <E T="03">et al.</E> 1995). This is below the 100 dB disturbance threshold for in-air sounds for pinnipeds (NMFS 2024). To affect the least practicable adverse impact on and marine mammals and based on Born <E T="03">et al.</E> (1999), which indicated that if the aircraft does not approach the seals closer than an altitude of 500 m (1,640 ft), the risk of flushing the seals into the wa ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 166k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━