# Takes of Marine Mammals Incidental To Specified Activities; Taking Marine Mammals Incidental to West Dock Facility Construction Activities Associated With the Alaska LNG Project in Prudhoe Bay, Alaska > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2021-03472 ## Record - **Collection:** Federal Register - **Document type:** Notice - **Published:** February 22, 2021 - **Citation:** 86 FR 10658 ## Text DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration [RTID 0648-XA418] Takes of Marine Mammals Incidental To Specified Activities; Taking Marine Mammals Incidental to West Dock Facility Construction Activities Associated With the Alaska LNG Project in Prudhoe Bay, Alaska AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION: Notice; issuance of an incidental harassment authorization. SUMMARY: In accordance with the regulations implementing the Marine Mammal Protection Act (MMPA) as amended, notification is hereby given that NMFS has issued an incidental harassment authorization (IHA) to the Alaska Gasline Development Corporation (AGDC) to incidentally harass, by Level A and Level B harassment, marine mammals during a particular activity (West Dock facility construction) associated with construction of the Alaska Liquefied Natural Gas (AK LNG) Project in Prudhoe Bay, Alaska. DATES: This Authorization is applicable from July 1, 2023 through June 30, 2024. FOR FURTHER INFORMATION CONTACT: Leah Davis, Office of Protected Resources, NMFS, (301) 427-8401. Electronic copies of the application and supporting documents, as well as a list of the references cited in this document, may be obtained online at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. In case of problems accessing these documents, please call the contact listed above. 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 issued or, if the taking is limited to harassment, a notice of a proposed incidental take authorization may be 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. Summary of Request On March 28, 2019, NMFS received a request from AGDC for an IHA to take marine mammals incidental to construction activities in Prudhoe Bay, Alaska. AGDC submitted revised applications on May 29, 2019; September 16, 2019; October 31, 2019, February 7, 2020; and February 25, 2020. The application was deemed adequate and complete on May 21, 2020. AGDC's request is for take of a small number of six species of marine mammals by harassment. Neither AGDC nor NMFS expects serious injury or mortality to result from this activity and, therefore, an IHA is appropriate. This IHA authorizes incidental take, for one year, for one discrete project (West Dock facility construction). This project is part of the larger AK LNG project for which AGDC has also requested a five-year Letter of Authorization (LOA) (84 FR 30991, June 28, 2019) for incidental take associated with project activities in Cook Inlet, Alaska. The larger project involves a pipeline that will span approximately 807 miles (mi) (1,290 kilometers (km)) from a gas treatment facility on Alaska's North Slope, which holds 35 trillion cubic feet (ft 3 ) of proven gas reserves, to a liquefaction and export facility in southcentral Alaska. Description of the Specified Activity AGDC plans to construct an integrated liquefied natural gas (LNG) project with interdependent facilities to liquefy supplies of natural gas from Alaska, in particular from the Point Thomson Unit (PTU) and Prudhoe Bay Unit (PBU) production fields on the Alaska North Slope (North Slope), for export in foreign commerce and for in-state deliveries of natural gas. AGDC plans to construct an AK LNG Gas Treatment Plant (GTP), which they would construct with large, pre-fabricated modules that that can only be transported to the North Slope with barges (sealifts). AGDC is proposing to modify the existing West Dock causeway and associated dock heads in Prudhoe Bay, Alaska in order to facilitate offloading modular construction components and transporting them to the GTP construction site. Vibratory and impact pile driving associated with the work at West Dock would introduce underwater sound that may result in take by Level A and Level B harassment of marine mammals in Prudhoe Bay, Alaska. AGDC proposes to conduct pile driving up to 24 hours per day. Construction is expected to occur on approximately 123 days from July through October during the open water ( i.e., ice-free) season. A detailed description of the planned construction project is provided in the Federal Register notice for the proposed IHA (85 FR 43382; July 16, 2020). Since that time, no changes have been made to the planned construction activities other than AGDC's planned construction timeframe, which has been shifted to July 1, 2023 to June 30, 2024. 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's proposal to issue an IHA to AGDC was published in the Federal Register on July 16, 2020 (85 FR 43382). That notice described, in detail, AGDC's activity, the marine mammal species that may be affected by the activity, and the anticipated effects on marine mammals. During the 30-day public comment period, NMFS received substantive comments from the Marine Mammal Commission, the Alaska Eskimo Whaling Commission (AEWC), the Center for Biological Diversity (CBD), the Pipeliners Union 798 United Association and its members, and a member of the general public. NMFS reopened the public comment period, at the request of the AEWC, from September 16, 2020 to November 16, 2020 (85 FR 57836; September 16, 2020). During the reopened comment period, NMFS received letters from the AEWC and the North Slope Borough (NSB), an additional reference from the CBD, and another comment from a member of the public. Two commenters stated that they believe that NMFS should not authorize marine mammal take for the AK LNG project in Prudhoe Bay, and another commenter and its organization's members expressed general support for the project. Our responses to the substantive comments received are provided here, and the comments have been posted online at: https://www.fisheries.noaa.gov/action/incidental-take-authorization-alaska-gasline-development-corporation-liquefied-natural-gas-0. Please see the commenters' letters for full detail regarding justification for their recommendations. Comment 1: During the initial public comment period on the proposed IHA, NMFS received a request from the Alaska Eskimo Whaling Commission (AEWC) requesting a 60-day extension of the comment period. The request indicated that the AEWC required more time to conduct their review and provide comments. The AEWC reiterated that (1) the Whaling Captains, community members, and the thousands of Alaska Natives who depend on the success of their harvests for their food security will be directly affected by any adverse effects from this project, and that (2) they have a direct stake in ensuring that this project is properly and thoroughly reviewed. Specifically, they noted that in addition to other challenges to reviewing the proposed IHA within the 30 days initially provided, the summer months are a time when many community members engage in a wide range of subsistence activities. Response: Given the factors listed by AEWC in its request, and the fact that the specified activity the IHA addresses was not scheduled to start until 2022 (now 2023), NMFS elected to provide additional time for public comment. Due to the timing of the request, it was not feasible to publish a notice in the Federal Register announcing a comment period extension prior to the close of the initial public comment period. Therefore, NMFS reopened the public comment period from September 16, 2020 until November 16, 2020 to receive additional information and comments (85 FR 57836; September 16, 2020). NMFS fully considered comments and information submitted during both comment periods in the preparation of this final IHA, and responses are included in this section. Comment 2: A commenter stated that NMFS should address in a substantive manner the apparent rejection of the Peer Review Panel's (PRP) recommendations and comments. Response: NMFS fully considered the PRP's comments, as described in the Monitoring Plan Peer Review section of this notice and the notice of the proposed IHA, and NMFS adopted some of the panel's recommendations. The final IHA includes additional recommendations by the PRP that were not included in the proposed IHA: the requirement for AGDC to conduct sound source verification (SSV) and to use three hydrophones in its passive acoustic monitoring (PAM) setup during the open water period, rather than one hydrophone required by the proposed IHA. For a full discussion of the panel's comments, and rationale for which recommendations were and were not adopted, please see the Monitoring Plan Peer Review section of this notice. Comment 3: Commenters expressed concern regarding the proposed take by Level A harassment of ringed and bearded seals, and take by Level A harassment of bowhead whales, which AGDC requested in its application. The commenters stated that an IHA should not authorize take by Level A harassment, and rather take by Level A harassment should only be authorized through a rulemaking process and subsequent LOA(s). One commenter stated that NMFS must do a better job to explain how it reached its conclusions that there will be no Level A harassment take and how AGDC will be able to ensure that no Level A harassment take occurs if the mitigation and monitoring is insufficient. Response: Section 101(a)(5)(D) of the MMPA and the associated implementing regulations allow for the authorization of incidental take by harassment (including both Level A and Level B harassment) through an IHA. However, for all incidental take authorizations, NMFS aims to avoid or minimize take by Level A harassment for all species, and, in this case, particularly bowhead whale given its importance to subsistence communities. As described in the Take Calculation and Estimation section of this notice, NMFS does not expect take by Level A harassment of bowhead whale to occur due to the shallow water depth in the project area. Additionally, no bowhead whales have been observed during Aerial Surveys of Arctic Marine Mammals (ASAMM) surveys in Block 1a (which encompasses the Level A harassment zone) since Block 1a surveys in began in 2016. Further, shutdown requirements within designated shutdown zones for low-frequency (LF) cetaceans (which include bowhead whales) are expected to prevent take by Level A harassment given the large size and visibility of bowhead whales. Additionally, Level A harassment zones are calculated with an associated duration component based on the amount of pile driving expected to occur within one day. Therefore, a marine mammal is not taken by Level A harassment instantaneously when it enters the Level A harassment zone, and given the shallow depths, even if a bowhead did enter the Level A harassment zone, we would not expect it to remain within the zone for a long enough period to incur permanent threshold shift (PTS). Take by Level A harassment of ice seals is authorized through this IHA. NMFS recognizes the importance of these animals to subsistence communities also and has worked with AGDC to minimize expected take of ice seals by Level A harassment to the extent practicable. As noted in the Negligible Impact Analysis and Determination section, we expect that the relatively small number of Level A harassment exposures, for seals only, will result only in slight PTS within the lower frequencies associated with pile driving. Comment 4: A commenter stated that there is no information in the record demonstrating that pile driving in the mid-Beaufort Sea, even in shallow water, will not disturb the fall bowhead whale migration as it travels west past the project area toward Utqiaġvik. The commenter described the 2019 and 2020 Utqiaġvik hunts. Please refer to the AEWC's comment letter, submitted during the comment extension, for additional detail on the 2019 and 2020 Utqiaġvik hunts, beyond what is provided below. The commenter stated that the early fall harvest in 2020 and the variation in harvest outcomes between 2019 and 2020 are only two examples of the unprecedented changes we are seeing in our marine ecosystem, including in the behavior of our resources. Given the unpredictability of our times, we are being forced to adapt our hunting practices and to become more flexible in our planning. As a result, harvesting periods and established time-area closures may vary in coming years. The commenter stated that as the changes we are experiencing continue to unfold, it is essential that everyone—hunters, developers, and regulators—increase our vigilance in monitoring changes to the whales' migratory behavior. The commenter stated that we do not know whether, given the whales' sensitivity to anthropogenic sounds and vibrations in the ocean, there is potential for deflection of the migration and other behavioral changes as the migration passes the proposed project. Unfortunately, based on the current record, the AEWC and NMFS cannot reasonably conclude that the construction activity will not have an impact on our critical fall bowhead whale subsistence harvest at Utqiaġvik. In its initial letter, the commenter stated that suspension of pile driving activities until Utqiaġvik completes its fall harvest would help to ensure adequate mitigation of impacts from that sound source, and the commenter initially recommended such a shutdown. However, in a second letter, the commenter stated that it recognizes that because the timing of the migration and completion of the harvest are difficult to predict, a shutdown throughout this period could be prohibitive from the perspective of the operator. Therefore, because the risk of interference will be borne by the Utqiaġvik Whaling Captains should the project go forward, the AEWC requests that NMFS direct AGDC to meet directly with the Whaling Captains Associations and to continue meeting with the AEWC. The AEWC also requests that NMFS reiterate the requirement for signing the Conflict Avoidance Agreement (CAA) as the Federal Energy Regulatory Commission (FERC) has done in its Order Granting Authorization of the Project. Response: Utqiaġvik is approximately 320 km (200 mi) from West Dock, and farther north and disruption of bowhead whale behavioral patterns as a result of AGDC's pile driving is not expected to impact individuals in the vicinity of Utqiaġvik. As described in the Estimated Take section, only a small number of bowhead whales (a maximum of 110, less than 0.65% of the stock) are expected to be disturbed by the construction activities, and even if some subset of these individuals deflected farther offshore near the project site, it is reasonable to predict that most individuals would likely resume a more typical migration path by the time they reach the Utqiaġvik hunting area and, therefore, significant impacts to the Utqiaġvik hunt would not be expected. Further, as noted by the commenter, it is impracticable for AGDC to cease pile driving during the Utqiaġvik whaling season, given the relatively short open water work window, the potential long duration of the whaling season, and the requirement to cease pile driving during the Nuiqsut whaling season, which occurs closer to the project site. As such, NMFS is not requiring AGDC to cease pile driving during the Utqiaġvik whaling season. However, AGDC is required to continue coordinating with subsistence groups, including the Whaling Captains Associations (Utqiaġvik, Nuiqsut, and Kaktovik), as described in the Plan of Cooperation (POC). This additional coordination may result in additional mitigation measures, if agreed upon by the communities and AGDC. AGDC will also conduct an SSV to determine sound source levels and propagation for the construction noise, which will further inform and refine our understanding of the distance to which the construction noise is expected to propagate and the likely impact on marine mammals (including bowhead whales). Regarding the CAA, AGDC is required by FERC to enter the CAA for the construction season. NMFS supports and encourages participation of applicants in the CAA process. Where measures likely to be identified through the CAA process are necessary to ensure an unmitigable adverse impact on subsistence uses or that the activities have the least practicable adverse impact on the affected species or stocks and their habitat (paying particular attention to the availability of the species or stock for taking for certain subsistence uses), similar or identical measures would be appropriately included in the IHA; however, NMFS does not require applicants to sign the CAA. Comment 5: Commenters suggested that NMFS require AGDC to use sound attenuation such as a bubble curtain. In a related comment, a commenter stated that NMFS thoughtlessly adopted the applicant's justification that “bubble curtains would be very difficult to deploy, and may not result in significant sound reduction.” The commenter stated that while NMFS could and should require bubble curtains to reduce pile driving noise, there are also other technologies available to reduce the noise from pile driving. For example, the commenter stated that NMFS should consider the effectiveness of pile caps, dewatered cofferdams, and other physical barrier mitigation. The PRP recommended consideration of bubble curtains, noise mitigation screens, and hydro sound dampers (nets with air-filled or foam-filled elastic balloons) (Bellmann 2014; Elmer and Savery 2014) to decrease the size of the Level A and Level B harassment zones. In a related comment, the Commission suggested consideration of other noise attenuation devices, but did not suggest specific devices. Rather, it recommended that NMFS determine whether any type of sound attenuation device could be effective in the shallow-water conditions of the proposed project site. In another related comment, a commenter stated that the benefit of sound attenuation is reducing risk of injury to seals and whales, diminishing the amount of sound that would propagate to the area of the main bowhead migration, and decreasing the size of Level A and Level B harassment zones. Reduction in the size of these zones would achieve more realistically observable zones (see PRP comments). Therefore, observers can do a better job of implementing mitigation measures to avoid Level A harassment takes more efficiently and realistically observe the entire Level B harassment zone to estimate actual takes. The commenter stated that if NMFS does not require sound attenuation devices, it should require AGDC to strengthen their proposed monitoring plan by requiring that observers be able to see most of the Level A and B monitoring zones during the open water period. Response: NMFS fully considered whether requiring the use of bubble curtains or other sound attenuation methods was appropriate for this IHA, and included additional explanation of these considerations below. Where conditions are appropriate, bubble curtains, cofferdams, and pile caps are generally the most common noise attenuation methods used in construction projects. The West Dock area is an industrial location with existing piles and dock structures. Conditions in the project area mean that the common practice of using bubble curtains for attenuation is not appropriate, as the water is shallow and therefore sound source level reductions are likely to be minimal (Caltrans, 2020), effective deployment of a bubble curtain system is logistically challenging in shallow water, and there is potential for sea ice. Sound attenuation devices have not been used for pile driving in this area during past projects. NMFS notes that in some instances during the project, such as during the gravel pouring at the barge bridge abutments, sheet piles will act as a cofferdam. NMFS considered this noise isolation in its effects analysis, but did not refer to the sheet piles as a cofferdam or mitigation measure, as they are a planned construction component, rather than an additional mitigation measure. Regarding the noise mitigation screens and hydro sound dampeners suggested by the PRP, as stated previously, the window for working in this area is extremely short, and construction will occur on a tight schedule in an effort to complete construction during one season. Given the short construction schedule, experimentation with less-common sound attenuation methods, such as mitigation screens and hydro sound dampeners, is not practicable. AGDC does not have a confirmed contractor and therefore cannot guarantee that a less common sound attenuation device will be available for use, as well as the tight construction schedule, it is impracticable to require AGDC to implement any other less-common sound attenuation methods. Regarding the recommended use of pile caps, AGDC has not yet selected a contractor, and therefore is unable to guarantee that a contractor will be able to implement certain methods, such as pile caps. Further, available data does not show that pile caps are effective for noise reduction (Caltrans, 2020). As stated in the Ensonified Area section of this notice, AGDC and NMFS modeled the Level A and Level B harassment zones using practical spreading. Given the shallow water in the project area, we expect that the Level A and Level B harassment zones included in the IHA are conservative. Additionally, AGDC intends to conduct SSV to verify sound source levels, propagation, and the Level A and Level B harassment zone sizes. NMFS intends to update the Level A and Level B harassment zone sizes with the verified zone sizes and potentially the associated shutdown zones, as appropriate. It is likely that the SSV will reflect smaller zone sizes, which would therefore be easier for protected species observers (PSOs) to observe a larger portion of the zones. Please see Comment 23 for a response to the recommendation to require AGDC to strengthen their proposed monitoring plan by requiring that observers be able to see most of the Level A and Level B harassment zones during the open water season. Comment 6: Commenters, and the Commission, noted that the PRP recommended that AGDC incorporate sound attenuation, such as bubble curtains, during pile driving. The commenters stated that NMFS did not address this recommendation by the PRP in the notice of the proposed IHA, and recommended that NMFS address it in the notice of the final IHA. One commenter further stated that NMFS has not adequately responded to the PRP's findings that many of the applicant's objectives cannot be reasonably obtained. Response: NMFS did not respond to the sound attenuation recommendation in the Monitoring Plan Peer Review section of the proposed or final IHA, as mitigation measures are beyond the scope of the PRP's charge, and NMFS did not find a response in that section to be appropriate. Rather, NMFS has responded to the PRP's recommendation, and that of public commenters, in its responses to Comment 5 in this section. NMFS provided an explanation of why it adopted certain recommendations from the PRP, and why it did not recommend others in the Monitoring Plan Peer Review section of the notice of the proposed IHA, and this notice. However, NMFS has updated that discussion given that AGDC has since determined that SSV and the use of additional hydrophones in its PAM setup are practicable. Please see the Monitoring Plan Peer Review section for additional detail. Comment 7: A commenter stated that the latest POC at the time of publication of the proposed IHA primarily focuses on past activities and outlines sporadic meetings over five years, during which time the project has gone through multiple changes in leadership. Often it is missing important details or includes a PowerPoint presentation but no indication of the discussion. Contrary to its express purpose, this POC does not: allow for evaluation of the quality of information provided to our hunters and residents; offer an account of any concerns that might have been raised by our communities in the public meetings; or provide for a path forward to address local concerns. For example, these preliminary meetings would have been the place to raise the issue of Level A harassment takes, to discuss any concerns related to potential impacts to Utqiaġvik, and to discuss the contingency plans in the ice-covered season. In short, this POC does not demonstrate that the applicant has engaged in consultation with local communities that is meaningful or honorable. Further, the POC is lacking details in Section 2 on ongoing communications. It states “Alaska LNG will develop a Communication Plan and will implement this plan before initiating construction or present.” Yet it does not outline or delineate a plan on moving forward. Response: AGDC's initial meetings with subsistence groups were part of the National Environmental Policy Act (NEPA) Environmental Impact Statement (EIS) public scoping process, so AGDC provided high-level information on the overall project and sought input, as detailed information regarding marine mammal impacts was not available at the time. AGDC has continued to meet with subsistence groups and has discussed more detailed project information in these more recent meetings. AGDC has updated the POC to include the information that the commenter stated was initially lacking. Regarding a path forward to address local concerns, AGDC will, in conjunction with NMFS, AEWC, and the Whaling Captains Associations from Utqiaġvik, Nuiqsut, and Kaktovik, develop and agree with these groups to a Communications Plan. The plan will identify the most effective way to communicate with local subsistence users and the Whaling Captains' Associations. It will be posted on the project website and sent to the organizations for feedback before being finalized. The goals along with the timeline, tools, and process for developing a robust Communications Plan are provided in Appendix C of the revised POC, available at https://www.fisheries.noaa.gov/action/incidental-take-authorization-alaska-gasline-development-corporation-liquefied-natural-gas-0. Comment 8: A commenter recommended that NMFS direct AGDC to meet directly with the Whaling Captains Associations to collaboratively develop appropriate means of mitigating potential impacts from the pile driving activity on the fall harvest at Utqiaġvik and to continue meeting with the AEWC. Response: The final IHA includes a requirement that AGDC must conduct the coordination with subsistence communities as described in the POC. The POC indicates that AGDC will meet with the Whaling Captains Associations (Utqiaġvik, Nuiqsut, and Kaktovik), and continue to meet with the AEWC. AGDC will continue to work with NMFS, AEWC, and the Whaling Captains Associations from Utqiaġvik, Nuiqsut, and Kaktovik, develop and agree to a Communications Plan. The goals along with the timeline, tools, and process for developing a robust Communications Plan are provided in Appendix C of the revised POC, available at https://www.fisheries.noaa.gov/action/incidental-take-authorization-alaska-gasline-development-corporation-liquefied-natural-gas-0. Comment 9: The Commission recommended that NMFS require AGDC to (1) meet with ice seal subsistence hunters in Nuiqsut and other North Slope communities and with members of the Ice Seal Committee to discuss its proposed construction activities in the winter of 2023 and the use of a subsistence advisor (as well as the possible use of trained dogs) and (2) revise its mitigation and monitoring measures as necessary to minimize disturbance of seals and subsistence hunting activities, based on input received. Response: The final IHA includes a requirement that AGDC must conduct the coordination with subsistence communities as described in the POC, which includes coordination with the ice seal committee. AGDC will only work during the winter/spring contingency period in the event that unforeseen circumstances or delays prevent them from completing construction during the open water season, and intends to clearly describe its potential winter construction to the ice seal committee and other subsistence groups. Additionally, the final IHA includes a requirement that AGDC must consult with an experienced subsistence advisor for detection of seal lairs for activities that occur in winter, and must implement a 150-m avoidance buffer in the event lairs are identified during construction. NMFS is not requiring AGDC to utilize trained dogs to detect ringed seal lairs, as there are a very limited number of trained dogs available for detecting seal lairs, and further Alaska Native subsistence hunters have raised concerns about polar bears following the scent of the dogs to hunt those lairs (pers. comm., Sheyna Wisdom). AGDC will continue to work closely with subsistence hunters from North Slope communities, including the ice seal committee to minimize disturbance of seals and subsistence hunting. If additional measures are agreed upon, they will be added to the POC, which as described previously, AGDC is required by the IHA to follow. Comment 10: A commenter stated that each year it devotes substantial resources toward negotiating a CAA with oil and gas companies to mitigate the impacts of oil and gas exploration on our subsistence lifestyle and our way of life. Thus, the analysis in the Federal Register of potential impacts to subsistence uses should begin with a discussion of whether the operator has signed the CAA and, if so, what the CAA includes as mitigation measures for our subsistence activities. By setting forth that discussion—and by incorporating those mitigation measures into the IHA, along with the measures already discussed by NMFS—the agency provides itself a firm, rational basis to issue a “no unmitigable adverse impact” finding, as required by the MMPA. The commenter noted that such steps are necessary even though a recent Order from FERC for this project requires a signed CAA before construction can begin. Another commenter stated that the proposed authorization depends on a CAA with Alaska Native villages, although it is unclear what the agreement will entail, and therefore, it is arbitrary for NMFS to rely on such agreements to determine that there will not be adverse impacts to subsistence use. Response: NMFS did not use the potential CAA to justify its preliminary unmitigable adverse impact determination in the proposed IHA. Rather, NMFS described what a CAA is, and mentioned that AGDC was considering whether it would enter a CAA or similar agreement with the AEWC, and that it would discuss and evaluate a CAA in the meetings discussed in the notice. As described in this final notice, AGDC has determined that it will enter the CAA for the construction season, as it is required by a FERC order (noted by commenters). NMFS' unmitigable adverse impact analysis and determination is based upon our analysis of the impacts of the action on subsistence uses and the mitigation measures included in the IHA and described in this notice. As stated above, NMFS supports and encourages participation of applicants in the CAA process. Where measures likely to be identified through the CAA process are necessary to ensure an unmitigable adverse impact on subsistence uses or that the activities have the least practicable adverse impact on the affected species or stocks and their habitat (paying particular attention to the availability of the species or stock for taking for certain subsistence uses), similar or identical measures would be appropriately included in the IHA, however, NMFS does not require applicants to sign the CAA. Substantial mitigation measures have been agreed upon to minimize potential impacts to subsistence activities as described in the Mitigation Measures section of this notice. The final IHA requires project aircraft to transit at an altitude of 457 m (1,500 ft) (except in specific circumstances, such as landing or takeoff), as included in the 2020 CAA. We note, though, that AGDC will sign the CAA in the year in which work is conducted rather than this year, so the exact mitigation measures included in the CAA are not known. However, in addition to the specific mitigation measures outlined in the IHA, the IHA requires AGDC to conduct coordination with subsistence communities to resolve conflicts and to notify the communities of any changes in the operation, as described in its POC, in addition to FERC's requirement that it sign the CAA prior to the start of construction. This additional coordination may result in additional mitigation measures, if agreed upon by the communities and AGDC. Comment 11: Commenters stated that the IHA focuses only on pile driving and does not address other activities associated with AGDC's project, such as screeding, gravel deposition, multi-beam hydrographic surveys, barge bridge tail wall pile driving, drilling/augering noise, construction of the seabed pad. A commenter further stated that gravel deposition for the causeway widening and 31-acre (0.13 km 2 ) dockhead and annual screeding of 13.7 acres (0.06 km 2 ) of seabed will destroy habitat for marine mammals and their prey. It will also cause sedimentation and turbidity in the project area and nearby vicinity. The filling and screeding activities will suspend contaminants in the water column, which can be taken up by marine mammals or their prey. The activities will also harm benthic organisms, and the sedimentation and turbidity will adversely affect benthic organisms, plankton, and fish that are prey for marine mammals (Bluhm and Gradenger, 2008). NMFS' rationale that screeding impacts are discountable because of naturally high sedimentation and turbidity is inadequate to address the additive impacts of the construction activities. Commenters stated that more consideration should be given to potential impacts from the sources listed above and to NMFS' decision to exclude these items from further analysis. One commenter asked NMFS to encourage organizations to deal with all aspects of a proposed project in future IHAs. A commenter also stated that NMFS provides an unsupported claim that because annual installation of a barge bridge and construction of a seabed pad sound like ordinary construction they do not expect take from these activities. If the AK LNG project, however, were not being built these construction noises would not occur. There is no evidence that normal construction noise and activities do not take marine mammals. A commenter stated that it is unclear if there has been discussion of the cumulative impacts from these sources (in reference to screeding, gravel deposit, and vessel traffic). Response: AGDC did not request take for the activities listed by the commenters. NMFS considers all aspects of a project in its analysis, and concurs that take is unlikely to occur for activities other than pile driving, and therefore, has not included take for those activities in the final IHA. As described in the proposed IHA, we do not expect take from screeding to occur as a result of AGDC's activities, however, the proposed and final IHAs include a requirement for AGDC to follow all mitigation measures described in the biological opinion, including a shutdown zone of 215 m for screeding. NMFS has added this specific requirement to the final IHA as well. Gravel deposition will produce a continuous sound of a relatively short duration, does not require seafloor penetration, and will affect a very small portion of habitat for marine mammals and their prey. Therefore, NMFS does not expect gravel deposition to result in marine mammal harassment. Further, a portion of the gravel deposition will occur behind sheet piles, which will act as an acoustic barrier which further supports the conclusion that take from gravel deposition is unlikely to occur. Regarding the planned multi-beam hydrographic surveys, which AGDC will perform to identify high and low spots in the seabed prior to each season, the survey would be conducted with equipment emitting sound above 200 kiloHertz (kHz), which (as described in the Marine Mammal Hearing section of the notice of the proposed IHA (85 FR 43382; July 16, 2020)), is above the highest frequency in the generalized hearing ranges of marine mammals (35 kHz for LF cetaceans, 160 kHz for MF and HF cetaceans, 86 kHz for phocids, and 39 kHz for otariids). We do not expect these surveys to take marine mammals, as marine mammals are unlikely to hear the surveys, much less respond to them. The stranding events in Madagascar and the Gulf of California (described in Comment 12, below) involved different sources from that which AGDC plans to use, and in those events, the sources were within marine mammal hearing ranges. NMFS included the barge bridge tail wall piles to be installed in-water in its analysis. A large portion of the barge bridge tail wall piles will be driven into dry ground, and therefore installation is unlikely to result in take of marine mammals. Please see Comment 16 for information about why NMFS does not expect take from in-air noise (such as pile driving on land). Construction of the seabed pad includes drilling or augering holes through the sea ice, an initial through-ice bathymetric survey, and smoothing of the seabed (including potential gravel fill and installation of rock-filled marine mattresses) is not predicted to result in the take of marine mammals for the reasons described below. Drilling/augering and the through-ice bathymetric survey are the first steps of the seabed pad preparation, which is expected to begin in February. Cetaceans are not predicted to be present in the area during this time (Quakenbush et al., 2018, Citta et al., 2016) and while ringed seals likely will be present, few, if any, spotted or bearded seals are likely to be present during that time (Bengston et al., 2005; Lowry et al., 1998; Simpkins et al., 2003). Therefore, take of cetaceans from drilling/augering is not expected, and take of spotted or bearded seals is so low as to be discountable. Given that drilling/augering is expected to occur in February, prior to ringed seals establishing lairs, we would not expect ringed seals to build their lairs close enough to the project so as to be disturbed by the drilling/augering activity. The potential that a seal might be disturbed by the activity and build its lair in an alternate location due to drilling/augering is accounted for in the Level B harassment takes, which have considered all likely take by behavioral disturbance, including that which could influence lair location. Smoothing of seabed (screeding) is unlikely to result in take, and NMFS has included a shutdown zone for screeding, as described above. Gravel deposition is not expected to take marine mammals for the reasons described above. While placement of rock-filled mattresses could result in take due to the physical presence of the equipment and mattresses, the likelihood of marine mammals being close enough to this activity to be taken is discountable, as the activity will occur in very shallow water (surface of the pad will be −6 ft (1.8 m) MLLW). As NMFS stated in the in the In-water Construction Effects on Potential Foraging Habitat section, a small amount of seafloor habitat will be disturbed or covered as a result of pile driving, gravel deposition, screeding, and other seabed preparation; however, for the reasons described in that section, NMFS does not expect those activities to meaningfully impact the amount of habitat available to marine mammals, and it will not result in the take of marine mammals. Further, while the project will likely increase turbidity in the immediate project area, this increased turbidity will be very localized and of a short duration, and it is not expected to have a significant impact on marine mammal habitat for the reasons described in the In-water Construction Effects on Potential Foraging Habitat section of the proposed IHA. The filling and screeding activities could also result in the suspension, and potentially consumption, of contaminants by marine mammal prey, and subsequently marine mammals, as suggested by the commenter; however, given the limited duration of filling and screeding activates, we expect suspension and consumption of contaminants by marine mammals and their prey would be minimal, and would not impact the fitness of any individual marine mammal. Installation of the barge bridge involves moving two barges into place against the mooring dolphins with tugs, where they will be ballasted and fastened to the causeway abutments and to each other. Moving the barges into place is expected to occur in a relatively slow, predictable manner, and while marine mammals do respond to vessel noise, NMFS does not expect that any behavioral responses to movement of the barges are likely to qualify as take of marine mammals. Ballasting the barges is unlikely to take a marine mammal, given the nature of the activity. Regarding discussion of the cumulative impacts from screeding, gravel deposition, and vessel traffic, NMFS has described immediately above (and in responses to Comments 13 and 14 for vessel noise and vessel strike) why these activities are unlikely to result in the take of marine mammals and the discussion is applicable to the unlikelihood of aggregate impacts of these activities as well. Comment 12: A commenter stated that geophysical surveys with echosounders and sonar have been linked to marine mammal harm and harassment. The proposed project will include geophysical surveys conducted prior to pipeline construction, including single-beam echosounder, multi-beam echosounder, and side-scan sonar. In 2008, an Independent Scientific Review Panel identified a multi-beam echosounder as the “most plausible and likely behavioral trigger” for a massive stranding event of hundreds of whales in Madagascar. In 2002, in the Gulf of California a beaked whale stranding event also correlated with a scientific research survey using multi-beam sonar. While these echosounders and sonar may have used lower frequencies than the one proposed here, it is concerning that high-power echosounders have the potential to negatively impact marine mammals across far distances from the source. NMFS failed to adequately consider the potential impacts from these surveys, and it should mitigate them with restrictions on low-frequency systems, larger safety zones, and time area closures. Response: As stated in response to Comment 11, AGDC will perform multi-beam echosounder hydrographic surveys to identify high and low spots in the seabed prior to each season; however, the survey would be conducted with equipment emitting sound above 200 kHz, which is outside of marine mammals' hearing ranges. AGDC did not propose and does not plan to conduct the other activities (single-beam echosounder and side-scan sonar) suggested in this comment; therefore, NMFS did not discuss these activities in the proposed or final authorization, and did not propose or require associated mitigation. Comment 13: Commenters stated NMFS must consider impacts from vessel noise (Erbe et al., 2019). The Chukchi and Beaufort Seas have very little vessel traffic, and the Arctic's seals and whales are at risk from vessel collisions and disturbance (McFarland, 2017). The determination that vessels do not need to be considered in this rulemaking because it is ordinary vessel traffic is in error. The proposed project will include numerous vessel trips for the construction of the AK LNG facilities in a sensitive remote area. The commenter further states that NMFS calculated that there will be 184 vessel trips per year associated with the Prudhoe Bay construction. Specifically, there is a significant risk that endangered bowhead and other whales will be harassed or harmed by vessels traveling from Asia to Dutch Harbor to Port Clarence to Prudhoe Bay Offshore Staging Area (south of Reindeer Island) to the West Dock. Notably, the route could endanger North Pacific right whales. NMFS must analyze the impacts of the proposed action on North Pacific right whales whose population hovers around 26-31 individuals. The commenter stated that NMFS must account for take by vessel traffic. First, low frequency noise from vessels tends to overlap with the communication sounds that marine mammals use, and therefore vessels can mask important communications (Southall et al., 2018; Putland et al., 2018; Clark et al., 2009). Ship noise has been associated with decreased foraging activity for humpback whales (Blair et al., 2016). Response: AGDC requested authorization of take associated with construction activities at West Dock in Prudhoe Bay. AGDC did not predict, and did not request authorization for take from vessel noise or vessel strike associated with vessel transit, or for any other activities other than West Dock project construction activities addressed in this notice, or activities in the related AK LNG Cook Inlet rule (85 FR 50720; August 17, 2020). NMFS concurs that such take is not likely to occur. Therefore, vessel transit noted by the commenter is not within the scope of this IHA. Because vessels will be in transit, exposure to ship noise will be temporary and relatively brief and will occur in a predictable manner, and also the sounds are of relatively lower levels. Regarding masking, elevated background noise from multiple vessels and other sources can interfere with the detection or interpretation of acoustic cues, but the brief exposures to one or two AGDC vessels at a time would be unlikely to disrupt behavioral patterns in a manner that would qualify as take. Please see Section 6.4.7 of the Biological Opinion for additional information about vessel noise, and Section 2.1.2 of the Biological Opinion for required mitigation measures associated with vessel transit. Regarding North Pacific right whales, the species does not occur in the project area, and therefore, no take of North Pacific right whales associated with the construction activities at West Dock is expected to occur. While North Pacific right whales and bowhead whales may occur in areas where project vessels will transit, take associated with vessel noise or vessel strike is not likely to occur for the reasons stated above (vessel noise) and in NMFS' response to Comment 14 (vessel strike). Comment 14: A commenter expressed concern about potential vessel strike associated with the AK LNG project, stating that collisions with vessels is one of the biggest threats to the world's endangered whales. In a related comment, a commenter recommended that NMFS require AGDC to implement vessel speed restrictions of 10 knots or less to reduce the risk of marine mammal ship strikes, reduce air pollution and reduce ocean noise that can mask marine mammal communications and displace marine mammals. Response: The potential for vessel strikes is so low as to be discountable during the construction phase of the project, given the lack of known previous ship strikes in the area (as discussed in section 6.3.2 of the Biological opinion) and the required mitigation measures for vessel transit included in Section 2.1.2 of the Biological Opinion, which are expected to further reduce the potential for vessel strikes. The mitigation measures in the Biological Opinion pertaining to vessel transit (which AGDC is required to adhere to), include a requirement for vessels traveling between West Dock/Endicott and Foggy Island Bay not to exceed speeds of 10 knots in order to reduce the risk of vessel strikes. AGDC only requested, and this IHA only authorizes, take associated with the construction at West Dock. Therefore, mitigation associated with other components of AGDC's broader AK LNG project is not included in the IHA. Potential impacts on marine mammals from vessels involved in the construction at West Dock were also discussed in Section 4.6.3.2 of the Alaska LNG Project Final EIS. NMFS served as a cooperating agency and participated in the development of the Alaska LNG Project EIS, and adopted the Final EIS on February 16, 2021. Comment 15: A commenter stated that ballast water and invasive species from ships can have harmful ecological impacts that may affect the Arctic habitat. Response: The impacts of AGDC's activity on the human environment (including invasive species and ballast water management) are addressed in the Alaska LNG Project Final EIS. Please see Section 4.3.3.3 of that document for additional information regarding planned ballast water management. AGDC did not request take of marine mammals associated with the introduction of invasive species. NMFS concurs that the introduction of invasive species from the exchange of ballast water is unlikely to result in the take of marine mammals and did not authorize associated take. Comment 16: A commenter stated that NMFS ignores out-of-water noise impacts on marine mammals. However, the marine mammals that are impacted by the proposed activities also inhabit sea ice and land above water. Some pinnipeds are equally susceptible to noise in air as in water (Kastak et al., 2007). Southall et al. (2019) provides in-air PTS and TTS thresholds for pinnipeds. In a related comment, a commenter stated that while NMFS admits that there are non-acoustic stressors, it nonetheless completely writes them off without any support. The commenter cited the following from the notice of the proposed IHA: “Potential non-acoustic stressors could result from the physical presence of the equipment and personnel; however, any impacts to marine mammals are expected to primarily be acoustic in nature.” Response: In-air stressors and non-acoustic stressors, such as the physical presence of land-based equipment and personnel, are not expected to affect cetaceans, given that cetaceans are present only in the water at some distance from shore and the activity and remain under water the majority of the time, and therefore are not expected to be exposed to these stressors. While AGDC may use barges to stage land-based equipment during some activities, these barges would be stationary, and at the project site where the water is extremely shallow (less than 14.2 ft. (4.3 m) at West Dock); therefore, we do not expect bowhead whales to occur close enough to the barge or equipment to be disturbed by its presence. Given the rare occurrence of beluga whales within the barrier islands, as evidenced by Block 1a ASAMM survey data, we expect the potential for beluga whales to be disturbed by barges to be so low as to be discountable. (Block 1a encompasses the area between the shoreline and the barrier islands, including Prudhoe Bay. ASAMM reports include just one beluga whale was observed in survey Block 1a in 2018.) We also do not expect gray whales to occur close enough to the barge or equipment to be disturbed by its presence, as gray whales rarely occur within the barrier islands, as also evidenced by Block 1A ASAMM surveys. As stated in the Acoustic Impacts section of the notice of the proposed IHA, there are no known pinniped haulouts near the project location. Therefore, it is unlikely that pinnipeds would be taken by exposure to in-air noise during the open water season. While there is a chance that a pinniped could swim by the construction site with its head out of the water during on-land construction such as pile driving, and be taken by Level B harassment, the likelihood of that occurring is so low as to be discountable. Additionally, there is a small chance that an individual animal could haul out in an area that is not a normal haulout site, but the chance of that occurring is also discountable. Further, if AGDC must work during their contingency period, they will begin pile driving prior to March 1 (see Mitigation Measures), so we would not expect ringed seals to build their lairs close enough to the project site to be taken by in-air sound during the contingency period, other than potentially by building their lair in an alternate location due to construction noise, as discussed in NMFS' response to Comment 27. While the presence of non-acoustic stressors could affect pinnipeds, a pinniped in the water that is close enough to be disturbed by a non-acoustic stressor is likely to have already been counted as taken due to in-water noise from activities occurring in the water. As noted above, while there is a chance that a pinniped could swim by the construction site with its head out of the water, or haul out in an area that is not a normal haulout site, and be taken by Level B harassment due to non-acoustic stressors, it is so unlikely as to be considered discountable. Therefore, while a pinniped could be taken due to disturbance from in-air or non-acoustic stressors during construction, we would expect very few of these takes, if any. Further, any such takes would be within the margin of error in the take estimate and their potential effects fully considered in the analysis. Accordingly, additional takes from non-acoustic stressors have not been added into this final IHA. Comment 17: A commenter stated that aircraft transportation is also part of the project; however, NMFS has completely ignored the impacts of aircraft noise and disturbance. Ice seals are sensitive to out-of-water noise, including hauling out in response to aircraft noise (Bradford and Weller, 2005; Born et al., 1999). Response: NMFS assessed the impacts of aircraft and does not expect aircraft noise from this project to result in the take of marine mammals. Born et al. (1999) analyzed “escape responses” ( i.e., hauled out animals entering the water) from an aircraft and a helicopter flying at an altitude of 150 m. The results of the study indicated that if the aircraft do not approach the seals closer than 500 m at that altitude, the risk of flushing the seals into the water can be greatly reduced. While Bradford and Weller (2005) note that helicopter presence resulted in flushing of most of the hauled out seals during observations, they did not note specific distances of the helicopter at which flushing occurred. The final IHA includes a requirement that all aircraft must transit at an altitude of 457 meters (m) (1,500 feet (ft)) or higher, to the extent practicable, while maintaining Federal Aviation Administration flight rules ( e.g., avoidance of cloud ceiling, etc.), excluding takeoffs and landing. This altitude is significantly higher than the 150 m aircraft and helicopter altitudes analyzed in Born et al. (1999). If flights must occur at altitudes less than 457 m (1,500 ft) due to environmental conditions, aircraft will make course adjustments, as needed, to maintain at least a 457 m (1,500 ft) separation from all observed marine mammals. Helicopters (if used) will not hover or circle above marine mammals. Comment 18: A commenter stated that NMFS' improperly narrowed analysis to only consider pile driving and removal activities is arbitrary because so many of the activities that are part of the project will also cause take of marine mammals. This resulted in an underestimate of take and improperly segmented the negligible impact determination. Additionally, many of these activities will take place over the multiple years and are therefore inappropriate for approval under an IHA. Response: First, activities other than pile driving and removal are not expected to result in the take of marine mammals for the reasons described in NMFS' responses to Comments 11 through 17 and the associated sections of this notice and the notice of the proposed IHA. The take estimate reflects the best available science, and a negligible impact determination is supported by the analysis in the Negligible Impact Analysis and Determination section of this notice and the notice of the proposed IHA. An IHA is appropriate, as AGDC expects the construction at West Dock, for which it requested authorization for the take of marine mammals, to occur over one year, and no serious injury or mortality is expected or authorized. While other project components associated with the AK LNG project may occur over a longer timeframe than just one year, we do not expect these activities to result in take for the reasons described in NMFS' Comment responses indicated above, and the associated sections of this notice and the notice of the proposed IHA. Second, the MMPA specifically provides for issuance of IHAs for periods of not more than one year, provided the appropriate findings are made, even when the activities associated with a larger project are expected to span multiple years. Comment 19: A commenter stated that additional potential impacts from activities which NMFS does not expect take (see Comments 11 through 17), as well as the proposed Level A harassment, should have been outlined in analysis and in the POC, as well as and in the meetings with the potentially affected communities. Response: Regulations at 50 CFR 216.104(a)(12) require IHA applicants conducting activities in or near a traditional Arctic subsistence hunting area and/or that may affect the availability of a species or stock of marine mammals for Arctic subsistence uses to provide a POC or information that identifies what measures have been taken and/or will be taken to minimize adverse effects on the availability of marine mammals for subsistence purposes. A plan must include a statement that the applicant has notified and provided the affected subsistence community with a draft POC, a schedule for meeting with the affected subsistence communities to discuss planned activities and to resolve potential conflicts regarding any aspects of either the operation or the POC, a description of what measures the applicant has taken and/or will take to ensure that planned activities will not interfere with subsistence whaling or sealing; and what plans the applicant has to continue to meet with the affected communities, both prior to and while conducting the activity, to resolve conflicts and to notify the communities of any changes in the operation. The POC includes these required components. It is not necessary for the POC to include a full discussion of the project and its impacts, as the relevant activities are addressed in an applicant's IHA application and NMFS' Federal Register notice of the proposed authorization (85 FR 43382; July 16, 2020). Comment 20: A commenter stated that AGDC needs to consult with NMFS, the NSB, and the AEWC to ensure that there are enough acoustic monitoring devices deployed and placed in the most appropriate locations and distances from West Dock. Additionally, multiple commenters recommended that NMFS require AGDC to implement the acoustic monitoring suggestions provided by the PRP, including real-time PAM. In a related comment, a commenter stated that while requiring one passive acoustic monitoring device, NMFS did not require any real-time monitoring of it. The device will be used only to collect sound source level and general presence of marine mammals after the fact. The commenter stated that despite the potential usefulness of PAM given that this is a stationary activity, NMFS failed to use it for avoiding impacts to marine mammals. Another commenter also invited AGDC and NMFS to investigate other methods to mitigate these impacts. Response: NMFS and AGDC have had extensive discussions about potential mitigation for marine mammals, including measures recommended by the PRP and by commenters. AGDC has consulted further with NSB and AEWC and intends to continue to do so, as stated in the POC. The required mitigation included in this final IHA ensures that AGDC's activities will have the least practicable adverse impact on the affected species and stocks, as well as subsistence uses of those species and stocks. Since publication of the proposed IHA, NMFS and AGDC have determined that it is practicable for AGDC to deploy three hydrophones in its PAM setup during the open-water season, as suggested by the PRP, rather than just one as stated in the proposed IHA. Please see AGDC's monitoring plan for additional information on the planned location for each device. If work is required during the ice-covered contingency period, AGDC will deploy one hydrophone during that construction. Additional hydrophones during this period are not expected to provide meaningful additional data, as stated in NMFS' response to Comment 24. Further, NMFS does not expect the use of PAM to conduct real-time mitigation to be notably more effective in minimizing impacts than the included requirements due to the limited expected marine mammal vocalizations expected during the project period. Moreover, the significant additional cost and effort associated with real-time PAM implementation are impracticable. Therefore, in consideration of these limitations, further described in the Monitoring Plan Peer Review section of this notice, NMFS did not require AGDC to use PAM to conduct real-time mitigation. Comment 21: A commenter stated that this IHA is for activities that are not set to begin for almost 2 years from the date of publication—July 1, 2022 to June 30, 2023—and will require a renewal. While the bulk of the noise will occur in the first year, the associated activity is likely to span six years. Section 101(a)(5)(D) is intended for projects limited to one year—beginning to end. The current project is much greater in time and in its scope of potential impacts than Congress intended. Response: As noted in the Changes from the Proposed IHA to Final IHA section, AGDC now expects to begin construction in 2023, and therefore, the effective date of the final authorization is one year later than proposed. While AGDC's inland construction is expected to occur over six years, AGDC plans to conduct the activities that are expected to result in the harassment of marine mammals within one year. Furthermore, while 101(a)(5)(D) may only authorize take of marine mammals for a duration of one year, the statute does not limit use of this section to activities that last one year or less. AGDC has requested authorization for activities that are expected to occur within one year, the activities are not expected to result in serious injury or mortality, and an IHA is appropriate. Regarding the start date, while the start date is not until July 2023, the IHA includes a provision stating that the authorization may be modified, suspended or revoked if NMFS determines: (1) The authorized taking is likely to have or is having more than a negligible impact on the species or stocks of affected marine mammals, (2) the authorized taking is likely to have or is having an unmitigable adverse impact on the availability of the affected species or stocks for subsistence uses, or (3) the prescribed measures are likely not or are not effecting the least practicable adverse impact on the affected species or stocks and their habitat. Regarding renewals, NMFS issued a one-year IHA with the understanding that AGDC can complete the planned work for which the IHA authorizes take within the one-year period. As necessary, NMFS makes the decision of whether or not to issue a Renewal after one is requested based on current information and the best available science, and in adherence with the renewal criteria described in the notice of the proposed IHA (85 FR 43382; July 16, 2020). NMFS may issue a one-time, one-year Renewal IHA if 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. Comment 22: A commenter stated that it is supportive of industrial activities that balance the development of resources and protection of subsistence resources to ensure our people meet their nutritional and cultural needs. The NSB and its residents not only benefit from the financial revenue generated by industry but also continue to rely upon subsistence resources. Balanced development helps fund State and NSB programs that provide many services for our residents while also ensuring the continued access to subsistence resources that our people have used for millennia. The AGDC's proposed project is likely such an example, but some of the mitigation and monitoring aspects need to be strengthened. In order for this balanced development to occur adequately, we need to have (1) quality baseline information about resources, (2) effective mitigation measures, and (3) appropriate monitoring. Response: This final IHA reflects the best available scientific information. NMFS has responded in separate comment responses to the commenter's specific recommendations regarding mitigation and monitoring measures. Comment 23: A commenter stated that the potential impact on ringed and bearded seals is a concern as is the inability of AGDC to effectively monitor the ensonified area. Monitoring the entire area is needed in order to mitigate possible takes and to estimate the actual number of takes relative to those that are permitted. The commenter further stated that it is important that industrial activities are mitigated as much as possible to reduce possible impacts to their hunters' ability to land whales, given challenges during the 2019 whaling season. A commenter stated that because Level A harassment takes could result in injury or mortality, observers play an important mitigation role. If a marine mammal is about to enter or is within the Level A harassment zone, the observer must halt operations to prevent injury. NMFS should require AGDC to have a monitoring plan that allows observers to see the entire Level A monitoring zone. In a related comment, a commenter stated that NMFS failed to meet the least practicable adverse impact standard because the proposed shutdown zones are smaller than the Level A harassment zones. The commenter asserts that NMFS failed to ensure that ice seals are adequately protected from take, and that rather than adopting more effective monitoring methods for the shutdown zone such as passive acoustic or thermal monitoring in response to the PRP's comment that PSOs would be unable to adequately monitor the shutdown zone, NMFS decreased the shutdown zone to 500 m for seals. Commenters stated that previous monitoring for oil and gas projects show that sightability curves begin to drop off at ~1 km for whales and ~200 m for seals even when conditions are suitable for seeing marine mammals (LGL et al., 2011, Figures 3.28 and 3.44). This means that whales and seals beyond those distances would be very difficult, if not impossible at times, to see. The result of this difficulty could be misinterpretations of data, such as a downward bias in estimated takes. The situation is even worse during inclement and windy weather or in low light conditions and at night. Observers stationed near the pile driving activities would not be able to adequately monitor the entirety of Level A zones. Regarding Level B harassment, a commenter stated that monitoring the Level B harassment zone is required by NMFS so that IHA applicants can estimate how many marine mammals they disturbed during the construction activities. This is important to ensure that Level B harassment takes are kept small and do not exceed those allowed by NMFS. Monitoring and mitigating impacts are especially important for marine mammals that are important for subsistence. In order to estimate the number of Level B harassment takes, there needs to be adequate monitoring of the Level B harassment zones. Currently, AGDC is planning to have observers at West Dock and use some passive acoustic monitoring. We expect that AGDC is planning to use observations within the viewable zone of observers and somehow expand those observations to the entire Level B zone to estimate takes. The Open Water PRP did a good job of explaining the weaknesses and difficulties of using this approach. NMFS should take advantage of the expertise of that panel and implement their recommendations on how to improve visual monitoring. Response: NMFS is required to include measures that ensure the least practicable adverse impact, as we have done here, but the MMPA does not require applicants to mitigate to avoid all takes. In this case, shutdown zones that encompass the vast majority of the Level A harassment zones (all but the outer portion of the phocid zone for impact pile driving, and an extremely small (6 m) portion of the mid-frequency (MF) cetacean zone during impact driving of 48-inch piles) have been required, resulting in avoidance of Level A harassment for all but minimal numbers for three pinniped stocks, and minimization of more severe Level B harassment. Monitoring of these shutdown zones is expected to be effectively accomplished with the monitoring protocols outlined below. The least practicable adverse impact standard includes a practicability component, and it is not practicable for AGDC to observe the entire Level A harassment zone for all species during all activities, given that the largest Level A harassment zone for phocids is estimated to be 843 m. The potential impacts of the activity were appropriately considered in the analysis, and given that the shutdown zones do not include the entire estimated Level A harassment zones for all activities, the IHA authorizes Level A harassment take of ringed, spotted and bearded seal, in case an animal enters the Level A harassment zone and remains in the zone for a long enough period to incur PTS. (Given the duration component associated with calculation of Level A harassment zones, a marine mammal that enters A Level A harassment zone does not always incur PTS.) There is no evidence suggesting that PTS (especially of the small degree that could potentially result from exposure to the pile driving in this activity) has the potential to cause mortality. As described in the Negligible Impact Analysis and Determination section, animals that experience PTS will likely only receive slight PTS, i.e., minor degradation of hearing capabilities within regions of hearing that align most completely with the frequency range of the energy produced by pile driving, i.e., the low-frequency region below 2 kilohertz (kHz), not severe hearing impairment or impairment in the regions of greatest hearing sensitivity. If hearing impairment occurs, it is most likely that the affected animal will lose a few decibels in its hearing sensitivity, which in most cases is not likely to meaningfully affect its ability to forage and communicate with conspecifics. The visibility distances cited by the commenter were also cited by the PRP, and originate from ship-based PSO observations in the Chukchi Sea (LGL et al., 2011). As NMFS described in the Monitoring Plan Peer Review section of this notice and the notice of the proposed IHA, while the 500 m shutdown distance for phocids is greater than the 200 m estimated by the PRP, AK LNG project PSOs will observe from elevated platforms on shore. Shore-based PSOs typically have greater visibility than vessel-based PSOs, and the elevation is expected to increase the distance that PSOs can effectively observe. NMFS consulted with AGDC and its contractor, who has extensive experience conducting monitoring for marine mammals on the North Slope of Alaska, and given the elevated PSO sites and equipment, AGDC expects that PSOs will be able to effectively observe phocids at distances up to 500 m, large cetaceans at 2-4 km, and belugas at 2-3 km, and NMFS concurs. Therefore, the shutdown zones included in the proposed and final IHA are the largest practicable for AGDC to implement, and that PSOs will be able to effectively observe marine mammals within. However, we note that the biological opinion includes a requirement for proportionate monitoring at all distances within the Level A harassment zone, such as a wedge of a circle, where that wedge contains at least 10 percent of the total zone ( i.e., a 36 degree wedge), in the event that PSOs cannot fully observe the Level A harassment zone. As noted above, the shutdown zones are expected to minimize the potential for more severe Level B harassment take of marine mammals. However, monitoring requiring that PSOs observe the entire Level B harassment zone is not included, as it is not practicable, given the zone sizes. Monitoring the full zones would require multiple vessels, which is a great expense, potential safety risk to PSOs, and would result in additional vessel traffic in the project area. Given that AGDC is attempting to complete construction during the open-water period and the extended daylight on the North Slope during that time, the majority of the work will be completed during daylight hours, despite AGDC's plans to work 24 hours per day. Additionally, as stated in the Mitigation for Marine Mammals and Their Habitat section, PSOs will test and use night vision devices (NVDs) and infrared (IR) for nighttime and low visibility monitoring. The IHA also requires AGDC to record visibility conditions every 30 minutes throughout construction, which will inform the portion of the Level A and Level B harassment zones PSOs were able to observe. The monitoring required by the final IHA, as well as the biological opinion, will allow NMFS to have an estimate of the actual number of takes that result from the activities relative to the number authorized. PSO observations in the area visible to them will provide a good sample of the actual takes of marine mammals. Additionally, the final IHA also includes a requirement for AGDC to deploy three hydrophones during the open-water season, and one during the contingency period (should construction be required during that time) to conduct PAM. While these devices will not be monitored in real-time or used for the purposes of implementing mitigation, PAM detections of marine mammals will further inform the actual number of takes that result from the activities relative to the number authorized. Please see the Monitoring and Reporting section for additional information. For the reasons described in the Monitoring Plan Peer Review section of this notice, NMFS is not requiring AGDC to use the distance sampling methods recommended by the PRP. Comment 24: Commenters expressed concerned that NMFS may allow pile driving to occur during the ice-covered season. When ice covers the Beaufort Sea, seals continue to use the area for feeding and pupping. Monitoring seals under ice, especially to prevent Level A takes and avoid serious injury or mortality, is next to impossible. Additionally, because the ocean and lagoons are ice covered, it is more risky to seals because they cannot simply stick their heads out of the water to avoid loud sounds. The commenter stated that if NMFS is going to allow AGDC to conduct pile driving during ice-covered period, adequate monitoring, that must include acoustic monitoring, should be required by NMFS. A commenter also said that disturbing or injuring seals could impact subsistence hunting and resources. In a related comment, a commenter questioned whether options to pile drive have been considered during the winter months. Response: AGDC has considered the potential to conduct pile driving during its winter/spring contingency period. However, AGDC intends to complete construction during the open-water season when the additional ice-related concerns raised by the commenter are not a concern, and seals are not building or using lairs. If AGDC does conduct construction during the ice-covered season, it will implement mitigation and monitoring measures for seals that are expected to avoid injury of seals, and minimize potential disturbance of seals, as described in the Mitigation Measures section of this notice, in NMFS' response to Comments 9 and 44, and in the Monitoring Plan Peer Review section of this notice. AGDC is highly motivated to complete work during the open-water season, as work during the ice-covered winter/spring contingency period would require additional equipment and include other constraints. Regarding monitoring, if construction during the contingency period is required, AGDC will deploy one hydrophone for PAM of marine mammals. Additional hydrophones during the contingency period are not warranted, as we do not expect cetaceans to be present in the area during this time (Quakenbush et al., 2018, Citta et al., 2016) and while ringed seals likely will be present, few, if any, spotted or bearded seals are likely to be present during that time (Bengston et al., 2005; Lowry et al., 1998; Simpkins et al., 2003). NMFS is not requiring AGDC to place the hydrophone in a certain location, as the location will depend on conditions in the construction year. As requested by the NSB and AEWC, if construction is required during the contingency period, AGDC will submit an acoustic monitoring plan to NMFS and AEWC for review once contractor is selected, but prior to the construction season. While the device will not be monitored in real-time or used for the purposes of implementing mitigation, PAM detections of marine mammals will further inform the actual number of takes that result from the activities relative to the number authorized. Regarding whether alternatives to pile driving have been considered, the Alaska LNG Project Final EIS identifies the alternatives that FERC and AGDC considered and assesses their impact on the human environment. The MMPA requires that NMFS analyze the specified activity that the applicant proposes (in this case, pile driving) in the context of the standards described in section 101(a)(5)(D), and issue an authorization provided the necessary findings are made. As described in this notice, NMFS has made the necessary determinations and issued the authorization. Comment 25: A commenter urged NMFS to withdraw its proposed IHA to allow the incidental take of marine mammals for the AK LNG Project in Prudhoe Bay. The commenter states that the project threatens the survival of threatened and endangered bowhead whales, ice seals, and other Arctic wildlife. Response: As described in this notice, NMFS has made the necessary findings, as required by Section 101(a)(5)(D) of the MMPA and NMFS' implementing regulations, and therefore, withdrawing the proposed IHA was not warranted. The best available information does not indicate that this authorization threatens the survival of threatened and endangered bowhead whales, ice seals, and other Arctic wildlife as suggested by the commenter. Comment 26: A commenter stated that NMFS underestimated take from acoustic stressors. The commenter asserted that there are several concerns with the estimates of take from pile driving and removal. Some marine mammals are more sensitive to noise, behavioral harassment was inadequately considered, and NMFS' density estimates are problematic. The commenter references specific examples of effects of noise on bottlenose dolphins, beluga whales, harbor porpoises, harbor seals, and bowhead whales. The commenter further stated that NMFS also does not take into account that bowhead whales travel in groups of two to five whales (Clarke et al., 2018; 2019). Fall activities will also result in higher takes of bowhead whales that occur in greater densities in September and October. NMFS also assumes that bowhead whales do not occur nearshore in waters less than 15 ft (4.5 m); however, a recent tagging study found that immature whales aggregate in shallow waters and that habitat degradation or displacement from shallow aggregation areas could have energetic costs for these young whales (Harwood et al., 2017). The commenter suggests that a recent study shows that beluga whales have sensitive hearing (Mooney et al., 2018). Beluga whales in the Beaufort Sea have site fidelity (Clarke 2018) and animals with site fidelity can be more vulnerable to noise impacts (Forney et al., 2017). Beluga whales also move into estuaries in the summer to rub on the substrate to molt (Anderson et al., 2017), which could mean that they are present in Prudhoe Bay in higher densities in the summer. Response: NMFS is aware that some species of marine mammals are more sensitive to noise than others and considers such sensitivity in development of mitigation measures. Of note, bottlenose dolphin and harbor seal do not occur in the project area, and specific examples of effects to these species are not relevant to this action. Harbor porpoises are considered to be extremely rare in the Beaufort Sea, particularly in the project area (Megan Ferguson, pers. comm., November 2019), and therefore no harbor porpoise take was proposed or authorized, and sensitivity of harbor porpoise to noise is also not relevant to this action. Regarding sensitivity of bowhead whales, the commenter references multiple papers regarding bowhead whale behavioral reactions to seismic airguns (please see CBD's letter for additional details), which are not part of this action. However, NMFS does recognize bowhead sensitivity to noise, and is requiring that during the Nuiqsut whaling season, AGDC must cease pile driving and vessels must transit landward of Cross Island to prevent potential impacts to bowheads during that important subsistence hunting period. Regarding the comment that NMFS did not consider bowhead whale group size, the densities calculated from the ASAMM surveys inherently consider group size, as they are calculated in consideration of many animals over a large area. (NMFS notes that for gray whale, it considered group size in addition to the density-based take calculation, as the calculation resulted in a number of takes that was smaller than the typical group size.) Regarding the presence of bowhead whales in shallow water, the paper referenced by the commenter (Harwood et al., 2017) references Koski et al. (1988) and Koski and Miller (2009), which found that immature bowhead whales that summer on the Beaufort shelf occur in shallow water, considered to be <20 m (65.6 ft). This is far deeper than the Level A harassment zone (approximately 5.8 m (19 ft) deep at the isopleth) where NMFS has determined bowhead whales are not likely to occur, as no bowhead whale has been recorded in waters less than 16.4 ft (5 m) deep (Clarke and Ferguson 2010). Further, there have been no bowhead whales observed in Block 1a during ASAMM surveys since they began in 2016, further supporting NMFS' conclusion bowhead whales are not expected to occur within the Level A harassment zone during construction. Block 1a encompasses the area between the shoreline and the barrier islands, including Prudhoe Bay. The beluga whale density estimates included in this notice reflect that beluga whales are more likely to be present in higher densities in the summer; however, NMFS conservatively used the summer density to estimate potential Level B harassment takes during all work, not just the portion likely to occur in the summer months. Additionally, the summer density is expected to be an overestimate for the AK LNG analysis, even for the summer months, because the data is based on sighting effort outside of the barrier islands, and beluga whales rarely occur within the barrier islands, as evidenced by Block 1a ASAMM survey data. One beluga whale was observed in survey Block 1a in 2018. However, this sighting was a “sighting on search,” meaning that the sighting occurred off of the survey transect, and therefore was not included in the density calculation. There have been no other Block 1a beluga sightings reported from ASAMM surveys to date. Therefore, the authorized number of takes by Level B harassment of beluga whale are likely an overestimate. Even if a beluga whale did respond to the construction noise to a degree that is considered a take by Level B harassment outside of the Level B harassment zone, such a take is likely within the margin of error of the take estimate. Comment 27: A commenter stated that NMFS irrationally discounted behavioral harassment that amounts to take. NMFS admits that behavioral harassment that displaces marine mammals from important feeding or breeding area for a prolonged period could be significant; however, it failed to ever consider whether the behavioral harassment resulting from the proposed activities amounts to take. For example, NMFS mistakes displacement of seals for mitigation when it relies on construction activities to discourage seals from building lairs near the project. Response: Winter and spring construction activities could result in the disruption of a ringed seal's behavioral patterns ( i.e., if a seal would have otherwise built a lair in the project area, it could be displaced). However, a seal which is taken by Level B harassment by behavioral disturbance (causing it to build its lair in a different location) would still be counted as one take by Level B harassment, though it is important to consider how the impacts of different types of take may impact an individual. Given that the average ringed seal ice structure density in the vicinity of the project area is 1.58 structures per km 2 (Table 11), and the in-air impact area of the project extends approximately 16.8 m from the project location, it is unreasonable to expect that more than a few takes from the displacement of seal lair construction, an above water behavior, would occur. These few specific potential takes are covered by the take estimate and authorization and their impacts have been appropriately considered in the analysis. There are many other available locations for the seals to construct their lairs away from the project area, so potentially preventing a few individual seals from constructing lairs in the project area is not expected to negatively affect pupping success. NMFS also notes that construction is only expected to occur during this contingency period if AGDC is unable to complete construction during the open-water season, and NMFS expects that if AGDC works during the contingency period, it would be because of construction delays (and therefore, days on which they did not work) during their planned open water work season. Comment 28: A commenter stated that NMFS assumed that prey would not be affected by the proposed activities, which is especially problematic because in only looking at the narrow one-year period, NMFS ignored the multiyear impacts of the proposed activities that will continue for at least six years. The commenter further states that NMFS acknowledges prey fish will avoid area during pile driving, but without support anticipates a “rapid return to normal recruitment, distribution and behavior.” Pile driving causes fish mortality and behavioral responses, including dispersing schools of fish (Casper et al., 2017; Hawkins et al., 2014; Herbert-Read et al., 2017). Response: As stated previously, AGDC requested take for pile driving associated with construction at West Dock, and NMFS concurs with AGDC's assessment that other activities raised by the commenter are not expected to cause the take of marine mammals, as described in response to Comments 11 through 17. Impacts to prey species resulting from the specified activity described in AGDC's application ( i.e., the construction activities at West Dock and associated pile driving) are, as appropriate, addressed in NMFS' analysis; however, it is not appropriate to consider impacts on prey from activities that are not part of the specified activity ( i.e., those that do not occur during the year that this IHA covers). NMFS acknowledged in the notice of proposed IHA that “potential prey ( i.e., fish) may avoid the immediate area due to the temporary loss of this foraging habitat during pile driving activities. The duration of fish avoidance of this area after pile driving stops is unknown, but we anticipate a rapid return to normal recruitment, distribution and behavior” (Hastings and Popper, 2005, Popper and Hastings, 2009). Further, in the In-water Construction Effects on Potential Prey section of the notice of proposed IHA and this notice, NMFS acknowledges that “[sound pressure levels (SPLs)] of sufficient strength have been known to cause injury to fish and fish mortality,” however, the West Dock area already has limited prey availability, and therefore, even if fish mortality did occur, we would expect that marine mammals would forage elsewhere in the vast foraging area available to marine mammals outside of the immediate project area. Comment 29: A commenter stated that NMFS underestimated take because its density estimates were wrong. For example, the density estimates for ringed seals were not corrected for unobserved animals. Also, lacking data for the summer and fall, NMFS simply cut density estimates by 50 percent without any rational basis for choosing this percentage. Importantly, NMFS not only relied on old density data for winter, but it also incorrectly calculated the density. While NMFS said that the most recent [ASAMM] surveys did not specify species, it is worth noting that NMFS relied on proportionality measures for determining the density of other seal species and could have done the same to use newer survey data. For example, for spotted seals NMFS assumes that they are 20 percent of seals and bearded seals are 17 percent of sightings. This same approach could be used to determine seal densities with more recent surveys (Clarke et al., 2020). Response: NMFS worked directly with Dr. Megan Ferguson of the National Marine Mammal Laboratory (NMML), one of the authors of the ASAMM reports, to calculate the cetacean densities using the available ASAMM survey data at the time (through 2018). NMFS has discussed the more recent 2019 surveys in the Marine Mammal Occurrence and Estimated Take sections of this notice. Further, while we expect that new ASAMM data will likely become available between the time that this IHA is issued and when AGDC begins work, given that the new data would be averaged with previous observations (beginning in 2011 for bowhead and gray whale and 2014 for beluga whale), we do not expect that new survey data would have more than a minor effect on the densities or estimated take calculations for cetaceans. Regarding the phocids take estimates, NMFS noted the limited availability of recent data in the notice of proposed IHA. As stated by the commenter, and in the notice of the proposed IHA, the ringed seal densities used to estimate take are not corrected for unobserved animals, and therefore may result in an underestimated density. However, as also noted, the fact that density calculations were conservatively calculated only from sightings observed in water depths greater than 10 ft. (3 m) (Moulton et al., 2002a, Moulton et al., 2002b, Richardson and Williams, 2003), while the water surrounding the project site is shallow (less than 14.2 ft. (4.3 m) at West Dock), is likely to result in some degree of overestimation of density. Also for ringed seals, as stated by the commenter, NMFS estimated that the summer ringed seal density would be 50 percent of the spring density, as also calculated for the Liberty Drilling and Production Island Final Rule (84 FR 70274; December 20, 2019). The surveys were flown in the spring, when the greatest percentage of seals have abandoned their lairs and are hauled out on the ice (Kelly et al., 2010) and therefore provide the best available information on ringed seal densities. During the summer, ringed seals range considerable distances; ringed seals make trips farther offshore to find sea ice during the summer (Von Duyke et al., 2020), supporting the expected lower densities in the coastal project area during the summer months in comparison to the spring when ringed seals mostly haul out on the ice. Therefore, NMFS continued to estimate the summer ringed seal density as 50 percent of the spring ringed seal density in the final IHA. NMFS has appropriately considered the best available, though limited, data regarding the density of ringed seals in both the density and take estimates. The commenter recommended that NMFS use the 2019 ASAMM surveys (Clarke et al., 2020) which were conducted during summer and fall 2019, to apply a method of estimating proportionality of seal species with that data, similar to which NMFS did in the proposed IHA with the Northstar data. While the ASAMM data is more recent, most ASAMM pinniped observations are not identified to species, and pinniped observations in the ASAMM surveys include walrus observations. The reports used in the take calculation in this IHA to determine proportionality of seals in the project area do not all include walrus observations. Therefore, it is not appropriate to apply these same proportions to the ASAMM data. NMFS is unaware of, and the commenter has not offered, more recent alternative sources that are appropriate for calculating proportions of all pinnipeds in the Beaufort Sea, including walrus. Comment 30: A commenter stated that NMFS' decision that take would only occur on 123 days rather than the AGDC's estimated 164 days is arbitrary and underestimates take. NMFS says that AGDC will complete construction during the April to October season and therefore the take will overlap with some piles being installed on the same day and thus only occur on 123 days, and therefore, NMFS also cuts the estimated marine mammal take by 25 percent. But then it allows for a contingency period in case the construction takes longer. The commenter states that activities during the contingency period will have increased impacts that have not been adequately analyzed. Moreover, NMFS states that “AGDC will only operate one hammer at a time during all pile driving;” which may mean that not more than one pile is installed on the same day. This underestimates both the negligible impact and small numbers determination. Response: As stated in the notice of the proposed IHA, AGDC expects to conduct the planned construction between July and October. As described in that notice, NMFS recognizes that AGDC may work outside of this period in their February to April contingency period; however, we expect that if AGDC works during the contingency period, it would be because of construction delays (and therefore, days on which they did not work) during their planned open water work season, rather than additional construction activity or time, and we expect that construction during that period would be very limited. Therefore, work during the contingency period is already accounted for in the take estimate and is not expected to meaningfully change the number of takes of marine mammals. Additionally, as stated in the Description of Marine Mammals in the Area of Specified Activities section of the notice of the proposed IHA, ringed seals and bearded seals are the only species of marine mammals that may occur in the project area during the winter/spring contingency period. Therefore, for all other species, work during the contingency period rather than the open water season would likely reduce the number of takes from the project. Bearded seal densities are expected to be much lower in the winter/spring than in the summer/fall, as noted in Table 12 of this notice. Therefore, if work is required during the contingency period due to construction delays during the open water season, takes of bearded seals are also expected to be lower than we have estimated in this authorization. For ringed seals, as NMFS noted in its response to Comment 27, there is a chance that a few seals could choose not to construct lairs in the project area due to construction noise in the contingency period, should construction occur during that time. However, as noted previously, construction during the contingency period, if any, is expected to be very limited. Further, the majority of the project area in Prudhoe Bay is of 3 m depth or less, and is expected to be dominated by bottomfast ice in Feb-April. Far fewer animals will be exposed to spring-based work because shorefast ice will be stationary, and only those seals that have breathing holes or lairs near the project are expected to be exposed. As stated by the commenter, and in the notice of the proposed IHA, AGDC will only operate one hammer at a time during all pile driving. The expected pile installation rate and number of piles AGDC expects to install per day incorporates the planned use of just one hammer at a time. Therefore, these estimates directly informed the expected amount of time spent pile driving in one day and therefore, the resulting take estimates on each construction day. Additionally, the plan to operate only one hammer at a time does not mean that multiple hammers (of the same or different types) cannot be used on the same day. Rather, it only means that one hammer can actually be operating, and therefore producing sound, at any given time. Comment 31: A commenter stated that NMFS' definition of small numbers conflates this criterion with the negligible impact requirement. Although NMFS uses different headings for its small numbers and negligible impact findings, by defining small numbers to be relative to the overall population the criterion ends up being similar to the negligible impact finding. The commenter further stated that instead, the small numbers requirement is intended to protect individual marine mammals. As the Ninth Circuit stated in Center for Biological Diversity v. Salazar , “[l]egislative history confirms our reading of the statute if such confirmation is needed. The House Report accompanying Section 101(a)(4)-(5) of the MMPA indicates that Congress intended “ `small numbers' ” and “ `negligible impact' ” to serve as two separate standards” ( Center for Biological Diversity v. Salazar, 695 F.3d 893 (9th Cir. 2012)). The requirement that NMFS authorize the take of only “small numbers” of individual animals is no mere technicality. Congress's intent was that the MMPA protect not only populations, but individual marine mammals. While the “negligible impact” standard should serve to protect the species or population as a whole, the “small numbers” requirement guarantees that Congress's directive to protect individual marine mammals is carried out. The commenter asserts the IHA fails to ensure that only small numbers of bowhead whales, ice seals, and the other marine mammals impacted by the AK LNG activities will be taken. Response: NMFS did not conflate the small numbers determination with the separate, negligible impact determination. These analyses and determinations are not only discussed under separate headings, as noted by the commenter, but are also analyzed using separate criteria. As stated in the small numbers section, the MMPA does not define small numbers and so, in practice, where estimated numbers are available, NMFS compares the number of individuals taken to the most appropriate estimation of abundance of the relevant species or stock in our determination of whether an authorization is limited to small numbers of marine mammals. 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. Additionally, other qualitative factors may be considered in the analysis, such as the temporal or spatial scale of the activities. NMFS directly stated in the Small Numbers section of the proposed IHA, and this final IHA, that “Our analysis shows that less than one-third of the best available population abundance estimate of each stock could be taken by harassment (in fact, take of individuals is less than two percent of the abundance for all affected stocks). The number of animals proposed to be taken for each stock would be considered small relative to the relevant stock's abundances even if each estimated taking occurred to a new individual, which is an unlikely scenario.” This proportional approach relative to the affected population is supported by CBD v. Salazar, the same case cited by the commenter, which found that “The Service can analyze small numbers in relation to the size of the larger population, so long as the `negligible impact' finding remains a distinct, separate standard.” The negligible impact standard remains a distinct, separate standard, as evidenced in the Negligible Impact Analysis and Determination section, through which NMFS evaluates the type, context, and severity of any authorized take to assess the impacts of the take on the fitness and reproduction of any affected individual marine mammals, and then, where appropriate, analyzes how any impacts on individual fitness may or may not accrue to affect rates of recruitment and survival of the species or stock. This analysis is clearly and appropriately distinct from the small numbers evaluation. For a more detailed discussion of NMFS' interpretation and implementation of the small numbers standard, we refer the reader to the Small Numbers section of the Final Rule for the Taking Marine Mammals Incidental to Geophysical Surveys Related to Oil and Gas Activities in the Gulf of Mexico (86 FR 5438; January 19, 2021). The commenter did not explain what it meant by its assertion that the IHA fails to ensure that only small numbers of bowhead whales, ice seals, and the other marine mammals impacted by the AK LNG activities will be taken. Comment 32: A commenter stated that NMFS failed to implement “means of effecting the least practicable impact” on marine mammals by instead requiring mitigation measures that are known to be ineffective and by failing to adopt additional mitigation measures. PSOs are not as effective in mitigating acoustic impacts as time-area restrictions ( NRDC v. Pritzker 828 F.3d 1125, 1133 (9th Cir. 2016), Conserv. Council of Hawaii, et al. v. National Marine Fisheries Service, et al., 97 F. Supp. 3d 1210, 1230 (D. Haw. 2015); Dolman et al., 2009). For example, visual observation detection rates of marine mammals decline significantly as sea states rise above Beaufort 1 (Barlow 2015). Another commenter also noted that the IHA must prescribe “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').” The commenter stated that NMFS must ensure any proposed mitigation is sufficiently protective. Response: The proposed and final IHAs require AGDC to implement a number of mitigation measures that would minimize impacts to marine mammals. These include PSOs, establishment of shutdown zones, pre-activity monitoring, use of NVDs and IR (for nighttime and low visibility monitoring), soft start procedures for impact pile driving, and a requirement to begin construction prior to March 1 in the event that construction during the contingency period is necessary. Further, the authorization includes a requirement for AGDC to cease construction during the Nuiqsut whaling season. Please see the Mitigation Measures section for information about how these measures are expected to reduce impacts to marine mammals. AGDC is required to abide by marine mammal mitigation measures NMFS consistently requires in pile driving incidental take authorizations, as they are considered effective at minimizing the impact to marine mammals. After evaluating all of the applicable information, NMFS has concluded that the required mitigation measures will affect the least practicable adverse impact on the affected marine mammal species and stocks and their habitats. Comment 33: A commenter recommended that NMFS place an overall cap on all authorizations for marine mammal incidental take in the Arctic. The commenter stated that various construction, vessel traffic, oil and gas, and other activities are cumulatively threatening the conservation and recovery of Arctic species. Response: The MMPA requires that NMFS issue an incidental take authorization, provided the necessary findings are made for the specified activity put forth in the application and appropriate mitigation and monitoring measures are set forth, as described in the Background section of this notice. Both the statute and the agency's implementing regulations call for analysis of the effects of the applicant's activities on the affected species and stocks, not analysis of other unrelated activities and their impacts on the species and stocks. That does not mean, however, that effects on the species and stocks caused by other activities are ignored. The preamble for NMFS' implementing regulations under section 101(a)(5) (54 FR 40338; September 29, 1989) explains 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 environmental baseline. Consistent with that direction, NMFS has factored into its negligible impact analyses 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 UMEs)). See the Negligible Impact Analysis and Determination section of this notice. Our 1989 final rule for the MMPA implementing regulations also addressed public comments regarding cumulative effects from future, unrelated activities. There we stated that such effects are not considered in making findings under section 101(a)(5) concerning negligible impact. We indicated that NMFS would consider cumulative effects that are reasonably foreseeable when preparing a NEPA analysis and also that reasonably foreseeable cumulative effects would be considered under section 7 of the ESA for ESA-listed species. In this case, we have found that the total marine mammal take from the planned activity will have a negligible impact on all affected marine mammal species or stocks, small numbers of marine mammals will be taken relative to the population size of the affected species or stocks, and that there will not be an unmitigable adverse impact on subsistence uses from AGDC's planned activities. Further, the cumulative effects to listed species of the specified activity in combination with other activities are analyzed in the ESA biological opinion, and the cumulative impacts to the human environment are considered in the Alaska LNG Project Final EIS. Section 101(a)(5(D) of the MMPA does not allow for a set limit on cumulative takings of marine mammals in the Arctic or other regions. Comment 34: A commenter stated that NMFS should consider time restrictions during September and October when the region is a BIA for bowhead whales. (Please see the figures in the Center for Biological Diversity's comment letter for additional information.) The commenter stated that vessel traffic through the Bering Strait should be prohibited during bowhead and beluga whale migration through the narrow passage. The commenter further stated that no activities should be authorized when ringed seals are building their subnivean lairs starting in late February until they leave their lairs. Response: Regarding additional restrictions on construction activities during September and October for bowhead whales, the proposed and final IHAs include a requirement that AGDC must shut down pile driving operations during the Nuiqsut whaling season, approximately August 25-September 15, though the shutdown will be adaptively managed based on coordination with the Whaling Captain Associations, as the exact whaling dates may change. Further, the final IHA includes a requirement that project vessels must transit landward of Cross Island during the Nuiqsut whaling season. Given the short duration of the construction season, prohibiting work during additional periods during the open water season is not practicable, and may extend the duration of the project beyond the one-year duration expected, which would extend the timeframe of impacts to marine mammals and incur additional costs for AGDC. Therefore, this recommendation is impracticable to implement. Additionally, the BIAs referenced by the commenter (Clarke et al., 2015) are addressed in the Description of Marine Mammals in the Area of Specified Activities section of the proposed IHA, and do not spatially overlap with the Level A or Level B harassment zones. The recommendation to prohibit activities from the time when ringed seals are building their subnivean lairs until they leave their lairs is not practicable to implement for the same reasons stated above for the bowhead whale recommendation. NMFS included mitigation in the proposed and final IHAs requiring AGDC to begin work by March 1 in the event that work during the contingency period is necessary, which NMFS expects will deter ringed seals from building their subnivian lairs in the project area, and will prohibit further take of ringed seals during that period. Additionally, construction will only occur during the late winter and early spring in the event that AGDC is unable to complete construction during the planned open-water season. Comment 35: A commenter stated that NMFS should require in-situ SSV be used to ensure that the Level A and Level B zones are sufficient. Response: As described in the Ensonified Area section, the Level A and Level B harassment zones were calculated using practical spreading. NMFS expects that the calculated zone sizes are conservative given that the water in the project area is shallow, and sound does not propagate as well in shallow water. However, since publication of the proposed IHA, AGDC has determined that it is practicable to conduct SSV, and this final authorization requires AGDC to do so. Comment 36: The Commission stated that NMFS used source level data from Caltrans (2015) for impact installation of 60-in cast-in-steel-shell (CISS) piles as a proxy for 48-in piles. However, the source levels included in Table I.2.-1 of Caltrans (2015) for 60-in CISS piles are attenuated source levels, not unattenuated source levels. Those piles were driven within either a cofferdam (see section I.3.2 in Caltrans 2015) or a sound attenuation device (isolation casing with a bubble curtain, see sections I.11 and I.11.2). NMFS indicated in the Federal Register notice that AGDC would not be using a sound attenuation device (85 FR 43406; July 16, 2020). Therefore, NMFS' use of the source levels from Caltrans was not appropriate. Caltrans (2015) did not include unattenuated source levels for impact installation of 60-in piles, and the attenuated source levels are less than unattenuated source levels for impact installation of 48-in piles. For impact installation of 48-in piles, NMFS has consistently used and deemed as best available source levels from Austin et al. (2016; see 84 FR 31004; June 28, 2019, 85 FR 19312; April 6, 2020, 85 FR 21404; April 17, 2020, 85 FR 31151; May 22, 2020, 85 FR 40252; July 6, 2020). The source levels of 186.7 decibels (dB) re 1 micro Pascal squared (μPa 2 )-sec single-strike (s-s) at 11 m, 198.6 dB re 1 μPa root-mean-square (rms) at 10 m, and 212.5 dB re 1 μPa peak (pk) at 11 m should have been used for AGDC's proposed activities as well (see values for pile IP5 in Tables 9, 11, and 7, respectively, in Austin et al. 2016). Those source levels are unattenuated, originate from Alaska, and have been used consistently in other recent IHAs that involve impact installation of 48-in piles. As such, the Commission recommended that NMFS use unattenuated source levels of 186.7 dB re 1 μPa 2 -secs-s at 11 m, 198.6 dB re 1 μPa rms at 10 m, and 212.5 dB re 1 μPa peak at 11 m from Austin et al. (2016) for impact installation of 48-in piles rather than the attenuated source levels from Caltrans (2015). Response: The Commission is correct that the proxy source levels NMFS used for impact driving 48-in piles (60-in CISS piles) are attenuated source levels, and that AGDC is not using a sound attenuation device. However, NMFS disagrees that the Austin et al. (2016) source levels suggested by the commenter are more appropriate than the proxy used in the proposed IHA. NMFS reviewed numerous source levels for impact installation of 48-in piles normalized to 10 m (Table 1). The proxy source levels used for impact installation of 48-in piles in the proposed authorization (pk, root mean square sound pressure level (SPL rms ) and sound exposure level (SEL)) are higher, and therefore more conservative, than the median source level in NMFS' review of available source levels for impact installation of 48-in piles. Given the shallow water depth at the Prudhoe Bay site, we expect that source levels for the AK LNG project will be lower than average. (Note that AGDC will also conduct SSV to verify the zone sizes.) Table 1—Acoustic Data From Unattenuated Impact Installation of 48″ Steel Pipe Piles Processed data (# of datasets used to calculate the median): Source dist. (m) Measured SPL pk (dB re 1 µPa) Measured SPL rms (dB re 1 µPa) Measured SEL (dB re 1 µPa 2 s) Normalized to 10-m SL SPL pk (dB re 1 µPa @10 m) Normalized to 10m SL SPL rms (dB re 1 µPa @10 m) Normalized to 10m SL SEL (dB re 1 µPa 2 s @10 m) Location Report TP#11 (2) 10 207 192 179.5 207 192 179.5 Naval Base Kitsap Naval Base Kitsap at Bangor Test Pile Program Acoustic Monitoring Report (I&R 2012); p. 61, 64, 67. TP#5 (2) 10 207.5 192 180.5 207.5 192 180.5 Naval Base Kitsap Naval Base Kitsap at Bangor Test Pile Program Acoustic Monitoring Report (I&R 2012); p. 62, 64, 67. A3 (3) 10 212.3 198.6 183.1 212.3 198.6 183.1 Columbia River Crossing Columbia River Crossing Test Pile Report (David Evans & Associates, 2011); pdf: 97. A4 (2) 10 213.45 199.65 183.05 213.45 199.65 183.05 Columbia River Crossing Columbia River Crossing Test Pile Report (David Evans & Associates, 2011); pdf: 109. B2 (3) 10 207.1 196.7 182 207.1 196.7 182 Columbia River Crossing Columbia River Crossing Test Pile Report (David Evans & Associates, 2011); pdf: 130. 10 200 183 173 200 183 173 Philadelphia Naval Shipyard NAVFAC Pile-driving at Atlantic Fleet Naval Installations (2017); p. 31. 10 200 185 174 200 185 174 Philadelphia Naval Shipyard NAVFAC Pile-driving at Atlantic Fleet Naval Installations (2017); p. 31. 10 203 187 176 203 187 176 Philadelphia Naval Shipyard NAVFAC Pile-driving at Atlantic Fleet Naval Installations (2017); p. 31. TT-13.5R Mid (9) 10 205 186 174 205 186 174 Naval Base Kitsap Naval Base Kitsap at Bangor Trident Support Facilities EHW-2 (2013); p. 94, 101, 107. IP5 11 212.5 197.9 186.7 213.3278537 198.7278537 187.5278537 Port of Anchorage Austin et al. (2016); p. 70-73. IP6 (off) 12 208.7 193.2 184.5 210.2836249 194.7836249 186.0836249 Port of Anchorage Austin et al. (2016); p. 70-73. IP1 14 213.2 199 185.1 216.1225607 201.9225607 188.0225607 Port of Anchorage Austin et al. (2016); p. 70-73. Median 207.3 193.4 181.3 Therefore, given that source levels at the project site are likely lower given the water depth, and considering that the 60-in CISS pile attenuated proxy source level is higher than the median source level of other source levels for impact installation of 48-in piles, NMFS has continued to use the initially proposed source levels to calculate the Level A and Level B harassment zones for the final authorization. NMFS intends to update the Level A and Level B harassment zone sizes with the verified zone sizes, and potentially the associated shutdown zones, as appropriate. It is likely that the SSV will reflect smaller zone sizes, which would therefore be easier for protected species observers (PSOs) to observe a larger portion of the zones. Comment 37: The Commission recommended that NMFS (1) increase the (a) Level A harassment zones from 1,575 m to 2,249 m for LF cetaceans, from 56 m to 80 m for MF cetaceans, and from 843 m to 1,204 m for phocids, (b) shutdown zones from 1,600 m to at least 2,250 m for LF cetaceans and from 50 m to at least 80 m for MF cetaceans, and (c) Level B harassment zone from 2,154 m to 3,754 m during impact installation of 48-in piles; (2) revise the numbers of Level A and B harassment takes during impact installation of 48-in piles; (3) include Level A harassment takes of bowhead whales during impact installation of 48-in piles or prohibit AGDC from conducting such activities at night or in low-visibility conditions; and (4) ensure the Level A harassment takes were estimated correctly for MF cetaceans and phocids during all proposed activities. Response: As stated in NMFS' response to Comment 36, NMFS did not adopt the commenter's recommended source level change for impact installation of 48-in piles. Therefore, it is not appropriate to adopt the recommended changes to the Level A and Level B harassment zones and shutdown zones that were based upon those recommended source level changes, nor is it appropriate to revise the number of Level A and Level B harassment takes that are estimated to occur during impact installation of 48-in piles, as those recommendations are based upon a change to the Level A and Level B harassment zone sizes. Take by Level A harassment of bowhead whale during any activity, including impact installation of 48-in piles, is still not expected to occur given the water depth in the Level A harassment zone. Further, there have been no bowhead whales observed in Block 1a (which encompasses the area between the shoreline and the barrier islands, including Prudhoe Bay) during ASAMM surveys since they began in 2016, further supporting NMFS' conclusion bowhead whales are not expected to occur within the Level A harassment zone during construction. Additionally, in the rare event that a bowhead whale were to enter the Level A harassment zone, it is likely that PSOs would detect the animal and that a shutdown would be implemented, preventing a take by Level A harassment. Therefore, Level A harassment take of bowhead whale is not included in this authorization. The final authorization does not prohibit AGDC from conducting construction activities at night or in low-visibility conditions, but notes that AGDC will use NVD and IR during those conditions. Additionally, given that [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2021-03472. Public record. Not legal advice.