SUPPLEMENTARY INFORMATION:

MMPA Background and Determinations

The MMPA prohibits the “take” of marine mammals, with certain exceptions. Among the exceptions is section 101(a)(5)(D) of the MMPA (16 U.S.C. 1361 et seq.) which directs the Secretary of Commerce (as delegated to NMFS) to allow, upon request, the incidental, but not intentional, taking by harassment of small numbers of marine mammals by U.S. citizens who engage ( printed page 57548) in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and the public has an opportunity to comment on the proposed IHA.

Specifically, NMFS shall issue an IHA if it 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”). NMFS must also prescribe requirements pertaining to the monitoring and reporting of such takings. The definitions of key terms, such as “take,” “harassment,” and “negligible impact,” can be found in the MMPA and NMFS' implementing regulations (see 16 U.S.C. 1362; 50 CFR 216.103).

On July 22, 2026, a notice of NMFS' proposal to issue an IHA to ONR for take of marine mammals incidental to ARA in the Beaufort and Chukchi Seas was published in the Federal Register (91 FR 46055). In that notice, NMFS provided estimates of the numbers, types, and methods of incidental take proposed for each species or stock, as well as the mitigation, monitoring, and reporting measures that would be required should the IHA be issued. The Federal Register notice also included analysis to support NMFS' preliminary conclusions and determinations that the IHA, if issued, would satisfy the requirements of section 101(a)(5)(D) of the MMPA for issuance of the IHA. The Federal Register notice included web links to a draft IHA for review, as well as other supporting documents.

During the 30-day public comment period, NMFS received three comment letters from private citizens. NMFS' consideration of public comments, which we respond to below, did not result in changes to the analysis or findings in the Federal Register notice of proposed IHA or the required mitigation, monitoring, or reporting measures set forth in the proposed IHA. There are no changes to the specified activity, the species taken, the proposed numbers, type, or methods of take, or the mitigation, monitoring, or reporting measures in the proposed IHA notice. No new information that would change any of the preliminary analyses, conclusions, or determinations in the proposed IHA notice has become available since that notice was published, and therefore, the preliminary analyses, conclusions, and determinations included in the proposed IHA are considered final.

Comment 1: A commenter asserted NMFS' preliminary negligible impact determination relied on flawed assumptions regarding cumulative multi-year acoustic exposure and recommended a programmatic Environmental Impact Statement (EIS) be prepared.

Response: NMFS disagrees with the commenter that its preliminary negligible impact determination relied on flawed assumptions, and the commenter does not provide persuasive evidence to the contrary. Neither the MMPA nor NMFS' 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). The 1989 final rule for NMFS' 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, the IHA issued to ONR is appropriately considered an unrelated activity relative to other ITAs currently in effect or proposed within the geographic region. The ITAs are unrelated in the sense that they are discrete actions under section 101(a)(5)(A) or (D) issued to discrete applicants.

Section 101(a)(5)(D) of the MMPA requires NMFS to make a determination that the take incidental to a “specified activity” will have a negligible impact on the affected species or stocks of marine mammals and will not have an unmitigable adverse impact on the availability of such species or stocks for taking for subsistence uses. NMFS' implementing regulations 50 CFR 216.104(a)(1) require applicants to include in their request a detailed description of the specified activity or class of activities that can be expected to result in incidental taking of marine mammals. Thus, the “specified activity” for which incidental take coverage is being sought under section 101(a)(5)(D) is generally defined and described by the applicant. Here, ONR was the applicant for the IHA, and we are responding to the specified activity as described in that application and making the necessary findings on that basis.

Regarding preparation of an EIS, an EIS is to be prepared when there may be potentially significant impacts to the human environment. There is no such evidence here and the commenter provides none.

Comment 2: A commenter asserted NMFS' negligible impact determination relied on what they describe as an arbitrary and unsupportable finding of zero takes by Level A harassment based on what it deemed flawed acoustic modeling and ineffective monitoring requirements. Specifically, the commenter asserted that the proposed visual mitigation requirements are unrealistic and ineffective, asserting that a watchstander cannot reliably detect a ringed seal at a distance of 180 meters (m) under low-visibility conditions. The commenter recommended that NMFS require passive acoustic monitoring (PAM) on all vessels and deployment platforms and expand the mitigation zones for all active acoustic source deployments and icebreaking activities to a minimum of 500 m.

Response: Take by Level A harassment is neither anticipated nor authorized based on the nature of ONR's planned activities, even absent mitigation, and NMFS has appropriately considered this in its negligible impact analysis and determination.

As stated in the notice of the proposed IHA, for beluga whale, modeling did not predict take by Level A harassment given that the acoustic sources are continuous with a low duty cycle and relatively short ping duration (4-30 seconds). For ringed seals, as stated in the notice of the proposed IHA, and NMFS does not anticipate, take by Level A harassment, nor does NMFS anticipate TTS from active acoustic sources. Since potentially impactful source levels from acoustic sources would not exceed 185 dB by system design limits, sound exposure levels would remain relatively low. Accounting for source level, spherical spreading, and a 30-second pulse length (table 1), a ringed seal would need to be in very close range of a single ping of an acoustic source to risk exposure at or ( printed page 57549) above the TTS threshold, an unlikely scenario given the low density of ringed seals in the Study Area. Given the exceedingly low potential for TTS, AUD INJ is not anticipated either.

In concluding that the Level A harassment estimates are flawed, the commenter incorrectly asserted that Navy's Acoustic Effects Model (NAEMO) assumes animals will exhibit active avoidance behavior before reaching injury thresholds. As stated in the Marine Mammal Occurrence and Take Estimation section of the notice of proposed IHA (91 FR 46055, July 22, 2026), NAEMO estimates acoustic effects on marine mammals without consideration of behavioral avoidance or mitigation. Further, the virtual animals (animat dosimeters) within NAEMO do not move horizontally or react in any way to avoid sound, which may overestimate impacts. Of note, NAEMO was only used to model take of beluga whales, and ONR has only reported sightings of beluga whales during transit, not during research activities or icebreaking when acoustic impacts are likely to occur; therefore, NMFS did not propose to authorize take of beluga whale by Level A harassment from active acoustic sources.

For icebreaking, a continuous noise source, modeling for all previous years of ARA icebreaking activities did not result in any estimated take by Level A harassment of marine mammals. Further, the estimated range to TTS is <15 m (see table 5 of the notice of proposed IHA (91 FR 46055, July 22, 2026)), and the range to AUD INJ would be even smaller. Given the proposed icebreaking activities have not changed, neither ONR nor NMFS expect these activities would result in Level A harassment of beluga whales or ringed seals and, therefore, NMFS did not authorize take by Level A harassment from icebreaking.

As described above, NMFS' analysis does not rely on implementation of mitigation measures or animal avoidance to support its conclusion that Level A harassment is not anticipated. Regarding the recommendation that NMFS require PAM on vessels and deployment platforms to supplement visual observers, the commenter does not explain why they expect PAM would be effective in detecting marine mammals nor does NMFS agree that this measure is warranted. The use of PAM on vessels (Research Vessel (R/V) Sikuliaq, U.S. Coast Guard Cutter HEALY, or another vessel) would require significant investment by ONR and the vessel operators for a research cruise that is planned for only 22 days in September-October 2026, and mitigation and monitoring data from past ARA include a limited number of animal detections during transit, acoustic source deployment and recovery, and icebreaking. Further, integrating PAM into all active source operations ( e.g., autonomous underwater vehicles, ice gateway buoys, moorings) would not mitigate the potential acoustic impacts for those sources but would only be a source of monitoring data and would only be available upon recovery of the sources (approximately 1 year after deployment). While NMFS agrees that PAM can be an important tool for augmenting detection capabilities in certain circumstances, its utility in reducing impacts to marine mammals during ARA is limited. PAM is only capable of detecting animals that are actively vocalizing, yet many marine mammal species vocalize infrequently or during certain activities, which means that only a subset of the animals within the range of the PAM would be detected (and potentially experience reduced impacts via shutdown of acoustic sources). Further, localization and range detection can be challenging under certain scenarios. For example, odontocetes ( e.g., beluga whales) are fast moving and often travel in large or dispersed groups which makes localization difficult. Given the effects to marine mammals from the sound sources analyzed are expected to be limited to Level B harassment; the limited timeframe of the planned research cruise (22 days); the limited number of animals that have been detected during transit, acoustic source deployment and recovery, and icebreaking during past ARA; the limited additional benefit anticipated by adding PAM as a detection method; and the cost and impracticability of implementing a full-time PAM program, we have determined the current requirements for visual monitoring are sufficient to ensure the least practicable adverse impact on the affected species or stocks and their habitat. Finally, we note the Navy supports research efforts on acoustic monitoring and will continue to investigate the feasibility of passive acoustics as a potential monitoring tool for ARA, as described in ONR's IHA application.

The IHA requires that during moored and drifting acoustic source deployment and recovery, ONR must implement a mitigation zone of 55 m around the deployed source. Deployment and recovery must cease if a marine mammal is visually detected within the mitigation zone. The IHA also includes a condition that vessels must avoid approaching marine mammals head-on and must maneuver to maintain a mitigation zone of 457 m around all observed cetaceans and 183 m around all other observed marine mammals, provided it is safe to do so. These zones appropriately mitigate the potential for acoustic impacts and vessel strike, and the commenter provides no supporting information as to why 500 m would be more appropriate.

Comment 3: Commenters disagreed with the renewal process, and one commenter stated the renewal process violates the statutory notice-and-comment requirements of MMPA section 101(a)(5)(D), which mandates a full 30-day public review period for IHAs.

Response: NMFS' IHA renewal process meets all statutory requirements. In prior responses to comments about IHA renewals ( e.g.,84 FR 52464, October 2, 2019; 85 FR 53342, August 28, 2020), NMFS explained the IHA renewal process is consistent with the statutory requirements contained in section 101(a)(5)(D) of the MMPA and, further, promotes NMFS' goals of improving conservation of marine mammals and increasing efficiency in the MMPA compliance process. Therefore, we intend to continue to implement the existing renewal process.

All IHAs issued, whether an initial IHA or a renewal, are valid for a period of not more than 1 year. The public has 30 days to comment on proposed IHAs, with a cumulative total of 45 days for IHA renewals. The notice of proposed IHA published in the Federal Register on July 22, 2026 (91 FR 46055) provided a 30-day public comment period and made clear that NMFS was seeking comment on the proposed IHA and the potential issuance of a renewal for the planned activities. As detailed in the Federal Register notice of proposed IHA and on the agency's website, eligibility for renewal is determined on a case-by-case basis and renewals are subject to an additional 15-day public comment period. The renewal is limited to (1) up to another year of identical or nearly identical activities as described in the Description of Proposed Activities section of the notice of proposed IHA or (2) the activities described in the Description of Proposed Activities section of the notice of proposed IHA would not be completed by the time the IHA expires, and a renewal would allow for completion of the activities beyond that described in the Dates and Duration section of the notice of proposed IHA (91 FR 46055, July 22, 2026). NMFS' analysis of the anticipated impacts on marine mammals caused by ONR's activities covers both the initial IHA ( printed page 57550) period and the possibility of a 1-year renewal. Therefore, a member of the public considering commenting on a proposed initial IHA also knows exactly what activities (or subset of activities) would be included in a proposed renewal IHA, the potential impacts of those activities, the maximum amount and type of take that could be caused by those activities, the mitigation and monitoring measures that would be required, and the basis for the agency's negligible impact determinations, least practicable adverse impact findings, and if applicable, small numbers and no unmitigable adverse impact on subsistence use findings (neither of which are applicable to this action)—all the information needed to provide complete and meaningful comments on a possible renewal at the time of considering the proposed initial IHA. Reviewers have the information needed to meaningfully comment on both the immediate proposed IHA and a possible 1-year renewal, should the IHA holder choose to request one.

While there would be additional documents submitted with a renewal request, for a qualifying renewal these would be limited to documentation that NMFS would make available and 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 need to 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 has been received that would alter the prior analysis. The renewal request would also contain a preliminary monitoring report, in order to verify that effects from the activities do not indicate impacts of a scale or nature not previously analyzed. The additional 15-day public comment period, which includes NMFS' direct notice to anyone who commented on the proposed initial IHA, 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. Combined together, the 30-day public comment period on the initial IHA and the additional 15-day public comment period on the renewal of the same or nearly identical activities, provides the public with a total of 45 days to comment on the potential for renewal of the IHA.

In addition to the IHA renewal process being consistent with all requirements under section 101(a)(5)(D) of the MMPA, 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 description of the process and express invitation to comment on specific potential renewals in the Request for Public Comments section of each notice of 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 IHAs and renewals respectively, NMFS has ensured that the public is “invited and encouraged to participate fully in the agency's decision-making process,” as Congress intended.

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 an IHA) with respect to potential impacts on the human environment.

This action is consistent with categories of activities identified in Categorical Exclusion B4 (IHAs with no anticipated serious injury or mortality) of the Companion Manual for NAO 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 has determined the issuance of this IHA qualifies to be categorically excluded from further NEPA review.

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 ensures 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 of endangered or threatened species, in this case with the NMFS Alaska Regional Office (AKR).

There is one marine mammal species (Arctic subspecies of ringed seal) with confirmed occurrence in the Study Area that is listed as threatened under the ESA. NMFS AKR issued a Biological Opinion on September 13, 2022, under section 7 of the ESA, on the issuance of an IHA to ONR under section 101(a)(5)(D) of the MMPA by the NMFS OPR. The Biological Opinion concluded that the action is not likely to jeopardize the continued existence of Arctic ringed seals and is not likely to destroy or adversely modify Arctic ringed seal critical habitat. This conclusion remains applicable to this IHA.

Authorization

Accordingly, consistent with the requirements of section 101(a)(5)(D) of the MMPA, NMFS has issued an IHA to ONR for authorization to take marine mammals incidental to ARA in the Beaufort and Chukchi Seas.

91 FR 57547