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 promulgated or, if the taking is limited to harassment, an incidental harassment authorization is issued. ( printed page 16925)

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 such species or stocks for taking for certain subsistence uses (referred to here as “mitigation measures”). NMFS must also prescribe requirements pertaining to monitoring and reporting of such takings. The definition of key terms such as “take,” “harassment,” and “negligible impact” can be found in the MMPA and NMFS's implementing regulations (see 16 U.S.C. 1362; 50 CFR 216.103).

NMFS' regulations implementing the MMPA at 50 CFR 216.107(e) indicate that IHAs may be renewed for additional periods of time not to exceed 1 year for each reauthorization. In the notice of proposed IHA for the initial IHA, NMFS described the circumstances under which we would consider issuing a renewal for this activity, and requested public comment on a potential renewal under those circumstances. Specifically, on a case-by-case basis, NMFS may issue a one-time 1-year renewal IHA following notice to the public providing an additional 15 days for public comments when (1) up to another year of identical, or nearly identical, activities as described in the Detailed Description of Specified Activities section of the initial IHA issuance notice is planned or (2) the activities as described in the Description of the Specified Activities and Anticipated Impacts section of the initial IHA issuance notice would not be completed by the time the initial IHA expires and a renewal would allow for completion of the activities beyond that described in the DATES section of the notice of issuance of the initial IHA, provided all of the following conditions are met:

1. A request for renewal is received no later than 60 days prior to the needed renewal IHA effective date (recognizing that the renewal IHA expiration date cannot extend beyond 1 year from expiration of the initial IHA).

2. The request for renewal must include the following:

• An explanation that the activities to be conducted under the requested renewal IHA are identical to the activities analyzed under the initial IHA, are a subset of the activities, or include changes so minor (e.g., reduction in pile size) that the changes do not affect the previous analyses, mitigation and monitoring requirements, or take estimates (with the exception of reducing the type or amount of take).
• A preliminary monitoring report showing the results of the required monitoring to date and an explanation showing that the monitoring results do not indicate impacts of a scale or nature not previously analyzed or authorized.

3. Upon review of the request for renewal, the status of the affected species or stocks, and any other pertinent information, NMFS determines that there are no more than minor changes in the activities, the mitigation and monitoring measures will remain the same and appropriate, and the findings in the initial IHA remain valid.

An additional public comment period of 15 days (for a total of 45 days), with direct notice by email, phone, or postal service to commenters on the initial IHA, is provided to allow for any additional comments on the proposed renewal. A description of the renewal process may be found on our website at: https://www.fisheries.noaa.gov/​national/​marine-mammal-protection/​incidental-harassment-authorization-renewals.

History of Request

On April 21, 2025, NMFS issued an IHA to USAF to take marine mammals incidental to the Eareckson Fuel Pier Repair project in Alcan Harbor on Shemya Island, Alaska (90 FR 17410, April 25, 2025), effective from April 21, 2026 through April 20, 2027. On January 30, 2026, NMFS received an application for the renewal of that initial IHA. As described in the application for renewal, the activities for which incidental take is requested are nearly identical to those covered in the initial authorization, consisting of activities that are covered by the initial authorization but will not be completed prior to its expiration. USAF submitted a revised version on February 9, 2026, which was deemed adequate and complete. As required, the applicant also provided a preliminary monitoring report (available at https://www.fisheries.noaa.gov/​action/​incidental-take-authorization-pacific-air-forces-regional-support-centers-construction-0) which confirms that the applicant has implemented the required mitigation and monitoring, and which also shows that no impacts of a scale or nature not previously analyzed or authorized have occurred as a result of the activities conducted. The notice of the proposed renewal incidental harassment authorization was published on March 11, 2026 (91 FR 11956).

Description of the Specified Activities and Anticipated Impacts

The purpose of this construction project is to conduct long-term repairs on the only existing fuel pier at Eareckson Air Station on Shemya Island, Alaska. As described in detail in the notice for the initial 2025 IHA (90 FR 11952, March 13, 2025; 90 FR 17410, April 25, 2025) and the original 2024 notices (88 FR 74451, October 31, 2023; 89 FR 17423, March 11, 2024), the in-water construction activity includes installation and removal of temporary 30-inch (in) (0.8 meter (m)) steel pipe piles and installation of permanent 42-in (1 m) steel interlocking pipe piles with vibratory and impact hammers and down-the-hole (DTH) drilling. During the 2025 construction season, 11 out of 60 30-in temporary steel pipe piles and 32 out of 208 42-in permanent interlocking steel pipe piles were installed, and 10 out of 64 30-in temporary steel pipe piles were removed. This work was completed over 42 construction days. The remaining necessary activities include installation of 49 30-in temporary steel pipe piles and 176 42-in permanent steel interlocking pipe piles, and the removal of 54 30-in temporary steel piles.

A minor change to the activities conducted by USAF was described in the renewal letter. The initial 2025 IHA noted that the vibratory pile driving and removal of 30-in steel pipe piles would be limited to 60 minutes per day (4 piles at 15 minutes each), and vibratory pile driving of 42-in steel interlocking pipe piles would be limited to 120 minutes per day (4 piles at 30 minutes each). Under this renewal, USAF plans to increase the daily amount of vibratory pile driving or removal of 30-in steel pipe piles to 120 minutes (8 piles at 15 minutes each) and increase the daily amount of vibratory pile installation of 42-in interlocking steel pipe piles to 210 minutes (7 piles at 30 minutes each). Additionally, USAF plans to conduct vibratory pile driving activities during low-light conditions, where Protected Species Observers (PSOs) will use equipment such as infrared light bars, night vision devices, and thermal imaging to ensure sufficient visibility. USAF proposed these changes to help address slower production rates than originally estimated, given challenging environmental conditions and mechanical delays. ( printed page 16926)

These changes increase the size of the estimated Level A harassment zones and the shutdown zones associated with vibratory pile driving and removal (see Description of Mitigation, Monitoring, and Reporting Measures). The increase to shutdown zones for vibratory pile driving and removal activities follows the same goals for mitigation articulated in the notice of the initial proposed 2025 IHA, i.e., the shutdown zones are equal to the estimated Level A harassment zones, and there is no increase to the estimated take numbers. Therefore, NMFS has determined that these changes are minor and that the requested renewal IHA is appropriate. Given delays from mechanical failures and inclement weather, USAF estimates that construction will be completed in 173 construction days under this renewal rather than 160 days as estimated in the initial 2025 IHA. Sounds produced by these activities may result in take, by Level A harassment and Level B harassment, of marine mammals located in Alcan Harbor, Alaska.

NMFS has authorized incidental take at the same levels as authorized in the initial 2025 IHA, except for Steller sea lion (authorized take has been reduced by the amount of potential take reported during completion of activities under the 2025 IHA, to maintain consistency with the associated Biological Opinion). A total of 12 marine mammal species (15 stocks) are expected to experience Level B harassment and 8 species (10 stocks) have the potential for Level A harassment (see Estimated Take).

All documents related to the initial 2025 IHA and the original 2024 IHA are available on our website: https://www.fisheries.noaa.gov/​action/​incidental-take-authorization-pacific-air-forces-regional-support-centers-construction-0.

Detailed Description of the Activity

A detailed description of the construction activities for which take is authorized may be found in the Notices of the Proposed (90 FR 11952, March 13, 2025) and Final 2025 IHA (90 FR 17410, April 25, 2025), and/or the Notices of the Proposed (88 FR 74451, October 31, 2023) and Final 2024 IHA (89 FR 17423, March 11, 2024). The location, timing, and nature of the activities, including the types of equipment planned for use, are a subset of and nearly identical to those described in the previous notices. The only minor change is the increase of vibratory installation and removal of 30-in steel pipe piles from 60 minutes per day to 120 minutes per day and the increase of vibratory installation of 42-in steel interlocking pipe piles from 160 minutes per day to 210 minutes per day (table 1). The longer duration of vibratory hammer use would create larger harassment and, therefore, larger shutdown zones than those analyzed in the initial 2025 IHA. USAF's plans include vibratory pile driving and removal at night, and anticipates that work will occur over 173 construction days rather than 160 days. NMFS has determined that the amount of take authorized through the initial 2025 IHA remains sufficient to cover the likely effects of the planned activity, and has made no changes to the authorized take, other than to account for reported potential takes of Steller sea lion.

USAF's revisions are summarized in table 1 below.

The renewal IHA is effective for a period not exceeding 1 year from the date of expiration of the initial 2025 IHA.

Description of Marine Mammals

A description of the marine mammals in the area of the activities for which take is authorized, including information on abundance, status, distribution, and hearing, may be found in the Notices of the Proposed (90 FR 11952, March 13, 2025) and Final 2025 IHA (90 FR 17410, April 25, 2025) for the initial 2025 authorization, and the Notices of the Proposed (88 FR 74451, October 31, 2023) and Final 2024 IHA (89 FR 17423, March 11, 2024). NMFS has reviewed the monitoring data from the initial 2025 IHA, current Stock Assessment Reports, information on relevant Unusual Mortality Events, and other scientific literature, and determined there is no new information that affects which species or stocks have the potential to be affected or the pertinent information in the Description of the Marine Mammals in the Area of Specified Activities contained in the supporting documents for the initial IHA.

Potential Effects on Marine Mammals and Their Habitat

A description of the potential effects of the specified activity on marine mammals and their habitat for the activities for which take is authorized here may be found in the Federal Register notices of the Proposed (88 FR 74451, October 31, 2023) and Final 2024 IHA (89 FR 17423, March 11, 2024). NMFS has reviewed the monitoring data from the initial IHA, recent draft Stock Assessment Reports, information on relevant Unusual Mortality Events, other scientific literature, and the public comments, and determined that there is no new information affects our initial analysis of impacts on marine mammals and their habitat.

Estimated Take

A detailed description of the methods used to estimate take for the specified activity are found in the notices of the Notices of the Proposed (90 FR 11952, March 13, 2025) and Final 2025 IHAs (90 FR 17410, April 25, 2025), and the Notices of the Proposed (88 FR 74451, October 31, 2023) and Final 2024 IHA (89 FR 17423, March 11, 2024). The source levels and marine mammal occurrence data applicable to this authorization remain unchanged from the previously issued IHAs.

USAF and NMFS reanalyzed the Level A harassment zones for vibratory pile installation and removal activities to reflect USAF's planned revisions (table 1), using the optional User Spreadsheet tool described in the initial ( printed page 16927) 2025 IHA (90 FR 17410, April 25, 2025). Table 2 provides the calculated Level A harassment isopleths from the initial 2025 IHA, and table 3 provides the calculated Level A harassment isopleths given the revised minutes of vibratory pile driving planned by USAF.

USAF will continue to implement shutdown zones that are equivalent to the Level A harassment zones during all vibratory pile driving and removal activities for all hearing groups, as described in the initial 2025 IHA (90 FR 17410, April 25, 2025). While USAF estimates a small increase in the number of construction days needed to complete the project under this renewal, data reported by PSOs monitoring during the 2025 construction period do not suggest that authorization of additional take is warranted. Similarly, the stocks taken, methods of take, and types of take remain unchanged from the previously issued IHA, as do the number of takes, which are indicated in table 4.

Description of Mitigation, Monitoring and Reporting Measures

The mitigation, monitoring, and reporting measures included as requirements in this authorization are identical to those included in the Federal Register notice announcing the issuance of the initial 2025 IHA (90 FR 17410, April 25, 2025). The discussion of the least practicable adverse impact included in that document and the notice of the proposed IHA remains accurate. The following measures are required for this renewal:

• USAF must employ NMFS-approved PSOs and establish monitoring locations to the maximum extent possible based on the required number of PSOs, required monitoring locations, and environmental conditions.
• Monitoring must take place from 30 minutes prior to initiation of pile driving activity (i.e., pre-start clearance monitoring) through 30 minutes post completion of pile driving activity.
• Pre-start clearance monitoring must be conducted during periods of visibility sufficient for the lead PSO to determine that the shutdown zones are clear of marine mammals.
• If a marine mammal is observed entering or within the shutdown zones pile driving activity must be delayed or halted.
• If pile driving is delayed or halted due to the presence of a marine mammal, the activity may not commence or resume until either the animal has voluntarily exited and been visually confirmed beyond the required shutdown zones or 15 minutes have passed (delphinids and pinnipeds) or 30 minutes for all other species without re-detected of the animal.
• Soft start techniques must be used when impact pile driving.
• Pile driving activity must be halted upon observation of either a species for which incidental take is not authorized or a species for which incidental take has been authorized but the authorized number of takes has been met, entering or within the harassment zone.
• USAF must shut down construction operations if a marine mammal comes within 10 m of construction activity to avoid direct physical interaction with marine mammals.
• USAF must submit a draft marine mammal monitoring report to NMFS within 90 days after the completion of pile driving activities or 60 calendar days prior to the requested issuance of any subsequent IHA for construction activity at the same location, whichever comes first. A final report must be prepared and submitted within 30 calendar days following receipt of any NMFS comments on the draft report.
• All injured or dead marine mammals must be reported to the Office of Protected Resources and to the Alaska Regional stranding network.

As noted above, the increase in vibratory pile installation or removal time from 60 minutes per day to 120 minutes per day (30-in steel pipe piles) and from 120 minutes per day to 210 minutes per day (42-in steel interlocking pipe piles) has increased the size of the associated Level A harassment zones. As such, the shutdown zones for these same activities have been revised.

Consistent with the mitigation required through the initial IHA, during all vibratory pile driving and removal activities for all hearing groups, and during all other activities for high frequency cetaceans, USAF will implement shutdown zones equivalent to the estimated Level A harassment isopleths. For all other hearing groups, during DTH and impact pile driving, shutdown zones are established at the distance that these species are assumed to be able to be reliably observed under typical conditions at the location.

Table 5 provides the shutdown zones from the initial 2025 IHA, and table 6 provides the provides the revised shutdown zones under this renewal given the revised minutes of vibratory pile driving and removal planned by USAF.

( printed page 16929)

Comments and Responses

A notice of NMFS' proposal to issue a renewal IHA to USAF was published in the Federal Register on March 11, 2026 (91 FR 11956). That notice either described, or referenced descriptions of, the USAF's activity, the marine mammal species that may be affected by the activity, the anticipated effects on marine mammals and their habitat, estimated amount and manner of take, and proposed mitigation, monitoring and reporting measures. NMFS received no substantive public comments.

Determinations

The construction activities are nearly identical to those analyzed for the initial IHA, as are the method of taking and the effects of the action. The higher minutes of vibratory pile driving and removal time each day does increase the size of the Level A harassment zones and shutdown zones slightly for these activities. This increase in zone sizes, however, does not change the anticipated take numbers analyzed in the initial IHA. In analyzing the effects of the activities for the initial IHA, NMFS determined that the USAF's activities would have a negligible impact on the affected species or stocks and that the authorized take numbers of each species or stock were small relative to the relevant stocks ( e.g., less than one-third of the abundance of all stocks). Aside from the revised shutdown zones associated with vibratory pile driving and removal activities, the mitigation measures and monitoring and reporting requirements as described above are identical to the initial 2025 IHA.

NMFS has concluded that there is no new information suggesting that our analysis or findings should change from those reached for the initial IHA. Based on the information and analysis contained here and in the referenced documents, NMFS has determined the following: (1) the required mitigation measures will effect the least practicable impact on marine mammal species or stocks and their habitat; (2) the authorized takes will have a negligible impact on the affected marine mammal species or stocks; (3) the authorized takes represent small numbers of marine mammals relative to the affected stock abundances; (4) USAF's activities will not have an unmitigable adverse impact on taking for subsistence purposes as no relevant subsistence uses of marine mammals are implicated by this action, and; (5) appropriate monitoring and reporting requirements are included.

National Environmental Policy Act

To comply with the National Environmental Policy Act of 1969 (NEPA, 42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, NMFS must review our proposed action ( i.e., the issuance of a renewal IHA) with respect to potential impacts on the human environment.

This action is consistent with categories of activities identified in Categorical Exclusion B4 (incidental take authorizations with no anticipated serious injury or mortality) of the Companion Manual for NOAA Administrative Order 216-6A, which do not individually or cumulatively have the potential for significant impacts on the quality of the human environment and for which we have not identified any extraordinary circumstances that would preclude this categorical exclusion. Accordingly, NMFS determined that the issuance of the initial IHA qualified to be categorically excluded from further NEPA review. NMFS has determined that the application of this categorical exclusion remains appropriate for this renewal IHA.

Endangered Species Act

Section 7(a)(2) of the Endangered Species Act of 1973 (ESA, 16 U.S.C. 1531 et seq.) requires that each Federal agency ensure that any action it authorizes, funds, or carries out is not likely to jeopardize the continued existence of any endangered or threatened species or result in the destruction or adverse modification of designated critical habitat. To ensure ESA compliance for the issuance of IHAs, NMFS consults internally whenever we propose to authorize take for endangered or threatened species.

The NMFS Alaska Regional Office issued a Biological Opinion under section 7 of the ESA (16 U.S.C. 1531 et seq.) on the issuance of an IHA and potential renewal IHA to USAF under section 101(a)(5)(D) of the MMPA by the NMFS Office of Protected Resources. The Biological Opinion concluded that the action is not likely to jeopardize the continued existence of ESA-listed fin whales (Northeast Pacific), humpback whales (Western North Pacific and Mexico North Pacific), sperm whales (North Pacific), and Steller sea lions (Western North Pacific).

Renewal

NMFS has issued a renewal IHA to USAF for the take of marine mammals incidental to conducting the Eareckson Fuel Pier Repair project in Alcan Harbor on Shemya Island, Alaska between April 21, 2026, and April 20, 2027.

91 FR 16924