[Federal Register Volume 86, Number 33 (Monday, February 22, 2021)]
[Notices]
[Pages 10658-10701]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-03472]



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Vol. 86

Monday,

No. 33

February 22, 2021

Part III





 Department of Commerce





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National Oceanic and Atmospheric Administration





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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; Notice

Federal Register / Vol. 86 , No. 33 / Monday, February 22, 2021 / 
Notices

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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.

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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

[[Page 10659]]

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 Utqia[gdot]vik. The commenter 
described the 2019 and 2020 Utqia[gdot]vik hunts. Please refer to the 
AEWC's comment letter, submitted during the comment extension, for 
additional detail on the 2019 and 2020 Utqia[gdot]vik 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

[[Page 10660]]

impact on our critical fall bowhead whale subsistence harvest at 
Utqia[gdot]vik.
    In its initial letter, the commenter stated that suspension of pile 
driving activities until Utqia[gdot]vik 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 Utqia[gdot]vik 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: Utqia[gdot]vik 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 Utqia[gdot]vik. 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 Utqia[gdot]vik 
hunting area and, therefore, significant impacts to the Utqia[gdot]vik 
hunt would not be expected. Further, as noted by the commenter, it is 
impracticable for AGDC to cease pile driving during the Utqia[gdot]vik 
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 Utqia[gdot]vik whaling season. However, 
AGDC is required to continue coordinating with subsistence groups, 
including the Whaling Captains Associations (Utqia[gdot]vik, 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.

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    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 Utqia[gdot]vik, 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 Utqia[gdot]vik, 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 Utqia[gdot]vik 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 (Utqia[gdot]vik, Nuiqsut, and Kaktovik), and 
continue to meet with the AEWC. AGDC will continue to work with NMFS, 
AEWC, and the Whaling Captains Associations from Utqia[gdot]vik, 
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

[[Page 10662]]

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

[[Page 10663]]

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

[[Page 10664]]

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

[[Page 10665]]

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

[[Page 10666]]

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

[[Page 10667]]

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

[[Page 10668]]

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

[[Page 10669]]

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.,

[[Page 10670]]

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

[[Page 10671]]

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

[[Page 10672]]

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

[[Page 10673]]

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 ([mu]Pa\2\)-sec single-strike (s-s) at 11 m, 198.6 dB re 1 
[mu]Pa root-mean-square (rms) at 10 m, and 212.5 dB re 1 [mu]Pa 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 
[mu]Pa\2\-secs-s at 11 m, 198.6 dB re 1 [mu]Pa rms at 10 m, and 212.5 
dB re 1 [mu]Pa 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<INF>rms</INF>) 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
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                               Normalized    Normalized
                                                       Measured    Measured                    to 10-m SL     to 10m SL     Normalized
  Processed data (# of datasets used to     Source    SPLpk  (dB    SPLrms     Measured SEL    SPLpk  (dB    SPLrms  (dB    to 10m SL
         calculate the median):            dist. (m)     re 1      (dB re 1      (dB re 1         re 1          re 1      SEL  (dB re 1            Location                     Report
                                                      [micro]Pa)  [micro]Pa)  [micro]Pa\2\s)    [micro]Pa     [micro]Pa   [micro]Pa\2\s
                                                                                                 @10 m)        @10 m)         @10 m)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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.

[[Page 10674]]

 
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.
rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
    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 most construction is 
expected to occur during the open water period when daylight is 
continuous (July and August), or the majority of the time (>70 percent 
of the time in September), the majority of construction will occur 
during daylight hours, even with work occurring 24-hours per day. 
(Although, NMFS recognizes that other conditions, such as fog, could 
limit visibility.)
    NMFS updated the Level A harassment take calculations for phocids 
and beluga whale by correcting the zone sizes used in the calculation. 
The updated calculation did not result in a change to the authorized 
Level A harassment take of beluga whale, but the authorized Level A 
harassment take of ringed seal, spotted seal, and bearded seal 
decreased. Please see the Estimated Take section for additional 
information on changes to the take estimate.
    Comment 38: The Commission recommended that NMFS (1) have its 
experts in underwater acoustics and bioacoustics review and finalize as 
soon as possible, its recommended proxy source levels for impact pile 
driving of the various pile types and sizes, (2) compile and analyze 
the source level data for vibratory pile driving of the various pile 
types and sizes in the near term, and (3) ensure action proponents use 
consistent and appropriate proxy source levels in all future 
rulemakings and proposed IHAs. If a subset of source level data is 
currently available (i.e., vibratory pile driving of 24-in steel 
piles), those data should be reviewed immediately and used--the data 
should not be retained until the other vibratory source levels are 
finalized.
    Response: NMFS concurs with the Commission's recommendation and has 
prioritized these efforts.
    Comment 39: A commenter stated that NMFS' finding that there would 
be no impacts on subsistence harvest is arbitrary.
    Response: NMFS did not find that there would be no impacts to 
subsistence harvests. Rather, NMFS found that, based on the description 
of the specified activity, the mitigation measures described to 
minimize adverse effects on the availability of marine mammals for 
subsistence purposes, and

[[Page 10675]]

the planned mitigation and monitoring measures, there will not be an 
unmitigable adverse impact on subsistence uses from AGDC's planned 
activities. NMFS has described the potential impacts to subsistence 
harvests in the Effects of Specified Activities on Subsistence Uses of 
Marine Mammals section of this notice, and the notice of the proposed 
IHA, and described the mitigation for subsistence harvests in the 
Mitigation for Subsistence Uses of Marine Mammals or Plan of 
Cooperation section of both notices.
    Comment 40: A commenter stated that the AK LNG activities will 
likely adversely impact the subsistence uses of the Native Village of 
Nuiqsut, which enacted Resolution 16-04 resolving ``that the United 
States should not schedule or hold any new oil and gas leases in the 
Beaufort or Chukchi Seas'' because the threat of oil and gas activities 
to subsistence uses, among other reasons. Even if pile driving 
activities are ceased during the bowhead whale hunt, vessel activities 
will adversely impact Nuiqsut's fall bowhead whale hunt and possibly 
other marine mammal harvest activities in the Beaufort Sea. However, 
NMFS failed to consider the impacts of vessels.
    The commenter further stated that the decision that there will be 
no impacts on Kaktovik subsistence use because the hunting grounds are 
farther off is arbitrary because the take authorization affects the 
same stocks of marine mammals that are used by Kaktovik hunters.
    Response: The commenter's mention of Resolution 16-04 is 
inapplicable to NMFS' action as it relates to issues outside of NMFS' 
authority. NMFS is responsible for authorizing the take of marine 
mammals incidental to certain specified activities, but does not allow 
or disallow the activities themselves. Also, the AK LNG project is not 
the same as an oil and gas lease in the Beaufort or Chukchi Sea.
    As the commenter noted, the proposed and final IHAs include a 
measure requiring AGDC to cease pile driving during the Nuiqsut whaling 
season (approximately August 25-September 15). Additionally, the final 
IHA includes a measure that requires AGDC to limit barges to waters 
landward of Cross Island during the Nuiqsut whaling season in an effort 
to avoid any potential impacts on subsistence uses.
    Regarding impacts on Kaktovik subsistence hunts, while the 
commenter is correct that the IHA does authorize the take of stocks of 
marine mammals which are harvested by Kaktovik hunters, the subsistence 
activities that Kaktovik engages in are unlikely to be affected in any 
of the ways described in the first paragraph of the Unmitigable Adverse 
Impact Analysis and Determination section of this notice. It is 
unlikely that the planned activities would have any effects on the use 
of marine mammals for subsistence by residents of Kaktovik given the 
distance from Kaktovik and Kaktovik's very limited use of waters 
offshore of Prudhoe Bay, and considering that the planned activities 
would occur in an already developed area. The best available 
information supports NMFS' finding that AGDC's activities will not 
result in an unmitigable adverse impact on subsistence uses as defined 
in 50 CFR 216.103.
    Please see NMFS' response to Comments 13 and 14 for a discussion of 
potential impacts of vessel transit.
    Comment 41: The Commission stated that given the lack of 
stakeholder meetings and the limited number of entities contacted to 
date, it recommends that, before further action is taken on issuance of 
an IHA, NMFS require AGDC to (1) revise its POC to include a summary of 
all meetings held to date with communities, subsistence groups, and co-
management organizations, (2) make available to the public and North 
Slope communities on a publicly accessible website its Communication 
Plan detailing how it will communicate its project plans and seek input 
on proposed mitigation and monitoring measures from all potentially 
affected communities, subsistence groups, and co-management 
organizations well in advance of the commencement of construction 
activities, and most importantly, (3) include in the Communication Plan 
measures for conducting timely and effective two-way communications 
with affected subsistence users immediately prior to, during, and after 
construction activities.
    Response: The POC has been updated with more information, including 
meeting summaries (Appendix A) and plans for continued communication 
with communities and marine mammal co-management organizations. AGDC 
travelled to Nuiqsut in 2018 and 2019, and has had individual outreach 
to Nuiqsut community leaders. There has also been substantial 
engagement with the AEWC over the past three years, which will continue 
as the Project progresses. The POC has been updated to reflect this 
communication. The projected start date is two years from the date of 
submission, so AGDC has ample time to coordinate directly with the 
Village of Nuiqsut, Whaling Captains Associations for Nuiqsut, Kaktovik 
and Utqia[gdot]vik and other marine mammal co-management organizations 
and has committed to do so. Further, AGDC has committed to ongoing work 
sessions with a working group of the AEWC. AGDC is committed to 
conducting timely and effective two-way communication with subsistence 
users before, during and after construction activities, and will work 
with subsistence groups and co-management organizations to create a 
Communications Plan, which it will post to the AK LNG project website. 
Please see the POC for additional information.
    Comment 42: A commenter stated that for the reasons stated in its 
comments, supplemental comments and petition for rehearing on FERC's 
Order granting authorization for the AK LNG project, NMFS cannot rely 
on the project's flawed EIS or inadequate Biological Opinion. The 
commenter stated that additionally for the IHA proposed here, NMFS must 
define a different purpose and need that is consistent with its duties 
to protect marine mammals, and it must evaluate different alternatives 
that would mitigate adverse effects on Arctic marine mammals.
    Response: Consistent with the regulations published by the Council 
on Environmental Quality (CEQ), it is common and sound NEPA practice 
for NMFS to participate as a cooperating agency and adopt a lead 
agency's (in this case FERC) NEPA analysis when, after independent 
review, NMFS determines the document to be sufficient in accordance 
with 40 CFR 1506.3. Specifically here, NMFS is satisfied that the 
Alaska LNG Project Final EIS adequately addresses the impacts of 
issuing the MMPA IHA and that NMFS' comments and concerns have been 
adequately addressed. NMFS' early participation in the NEPA process and 
role in shaping and informing analyses using its special expertise 
ensured that the analysis in the Alaska LNG Project Final EIS is 
sufficient for purposes of NMFS' own NEPA obligations related to its 
issuance of incidental take authorizations under the MMPA.
    Regarding the purpose and need, NMFS' purpose and need is 
consistent with its duties to protect marine mammals. It is clearly 
stated in Footnote 8 (p. 1-11) of Volume 1 of the Alaska LNG Project 
Final EIS, stating ``The purpose of NMFS's action, which is a direct 
outcome of AGDC's request for authorization to take marine mammals 
incidental to construction activities in Cook Inlet and Prudhoe Bay, is 
to evaluate AGDC's applications pursuant

[[Page 10676]]

to the MMPA and 50 CFR 216 and to issue incidental take authorizations 
(ITAs), if appropriate. The need for NMFS' action is to consider the 
impacts of AGDC's activities on marine mammals and ultimately allow 
AGDC to conduct its activities in compliance with the MMPA if the 
requirements of section 101(a)(5)(A) and (D) are satisfied.'' NMFS' 
purpose and need are supported by the analysis in FERC's Alaska LNG 
Final EIS for AGDC's proposed activities associated with the AK LNG 
Project.
    Regarding the alternatives, NMFS' involvement in development of the 
Alaska LNG Project Final EIS and role in evaluating the effects of 
incidental take under the MMPA ensured that the Alaska LNG Project 
Final EIS includes adequate analysis of a reasonable range of 
alternatives. For NMFS, declining to issue the requested ITA to AGDC 
constitutes the NMFS No Action Alternative, which is consistent with 
our statutory obligation under the MMPA to grant or deny ITA requests. 
Since the underlying activities would not be carried out, as indicated 
in the Alaska LNG Final EIS (Executive Summary, page ES-6), the 
requested take of marine mammals would not occur. NMFS considers the No 
Action Alternative to be the environmentally preferable alternative as 
negative impacts to marine mammals would be avoided. If no construction 
activities occur, no disturbance to marine mammals would occur from 
pile driving associated with construction of the LNG facilities and 
pipelines/transmission lines.
    The other alternative NMFS considers is its Proposed Action, which 
called for issuance of an ITA to the applicant, AGDC, to authorize the 
requested take subject to specified requirements, including mitigation, 
monitoring and reporting requirements. As part of this alternative, and 
through the public and agency review processes under NEPA and MMPA, 
NMFS considers a range of mitigation measures to carry out its duty to 
identify other means of effecting the least practicable adverse impact 
on the species or stocks that are the subject of the ITA request. For 
AGDC's construction activities in Prudhoe Bay, these measures were 
initially identified in the proposed IHA (85 FR 43382; July 16, 2020) 
and modified for this final IHA in response to public comment and 
agency review. The Proposed Action alternative considered by NMFS is 
consistent with the Proposed Action (Preferred Alternative) evaluated 
by FERC, as it would provide the ITAs necessary to achieve the 
activities identified in that alternative and analyzed in the Alaska 
LNG Project Final EIS.
    Finally, NMFS' Proposed Action to issue ITAs to AGDC for 
construction activities associated with the AK LNG Project and FERC's 
Proposed Action (also the Preferred Alternative) effectively meet NMFS' 
stated purpose and need for acting. NMFS has an obligation to issue a 
requested ITA if certain statutory and regulatory determinations are 
made after providing for adequate public review and comment concerning 
the ITA request. Denying the application, as would be required under 
the No Action Alternative, would be contrary to NMFS' responsibilities, 
given the results of the analysis conducted under the MMPA, and would 
thus not support NMFS' ability to meet its purpose and need for acting.
    This approach to evaluating a reasonable range of alternatives is 
consistent with NMFS policy and practice for issuing MMPA incidental 
take authorizations. NMFS has independently reviewed and evaluated the 
Alaska LNG Project Final EIS, including the range of alternatives, and 
determined that the EIS fully satisfies NMFS' NEPA obligations related 
to its decision to issue this IHA, and we have adopted it.
    Regarding the Biological Opinion, NMFS consulted internally with 
NMFS' Alaska Regional Office (AKRO). AKRO conducted a thorough analysis 
and we refer any questions or comments on that document to the AKRO.
    Please see the mitigation-related comments for a response to the 
commenter's recommendations for inclusion of measures that would 
mitigate adverse effects on Arctic marine mammals.
    Comment 43: The Commission stated that although operators are 
generally able to complete the installation of a pile if visibility 
becomes limited due to nightfall or deteriorating weather conditions, 
NMFS does not typically allow pile driving to occur 24-hours a day in 
its authorizations. It is not clear whether AGDC has discussed its 
plans to conduct pile driving at night with local communities, as no 
reference was made to nighttime pile driving in the outreach materials 
provided in the POC. Concerns have been raised by Native Alaskan 
communities about activities occurring ``all night long'' for other 
projects. Restricting pile driving to daylight hours would help to 
ensure that AGDC is effecting the least practicable adverse impact on 
affected species. The Commission recommended that NMFS include in the 
final authorization the requirement that AGDC conduct pile driving 
activities during daylight hours only.
    Response: NMFS analyzes the action that an applicant has proposed. 
While many applicants propose to conduct pile driving during daylight 
hours only, in which case NMFS discusses that in the Federal Register 
notice, and sometimes elects to include it in the IHA itself, AGDC 
proposed to conduct pile driving up to 24-hours per day.
    Work is expected to start in July, when there are 24 hours of 
available sunlight for visibility, so the crews will do their best to 
get as much done in the early months of the project as possible. As the 
available daylight wanes and fall approaches, AGDC will test NVDs to 
detect marine mammals in low visibility. If these devices do not prove 
to be effective in detecting marine mammals, lighting will be used to 
monitor the immediate area around the pile driving work.
    The open water season is extremely short, and therefore, the 
ability to work 24-hours per day is a key component to AGDC's ability 
to complete construction on time, particularly given the requirement 
for AGDC to shut down work during Nuiqsut whaling. Shorter workdays 
would likely extend the number of days required for the work (extending 
the overall duration of impacts on marine mammals), and could require a 
second work season and involve significant equipment and manpower 
expense, which is impracticable.
    In AGDC's most recent project update to AEWC in the Third Triannual 
Meeting (10/28/2020), AGDC discussed pile driving plans, including the 
24 hour work day.
    Comment 44: To ensure that seal lairs in the construction area are 
identified and avoided as proposed, the Commission recommended that 
NMFS include in the final authorization the requirement that AGDC (1) 
use an experienced subsistence advisor, and consider the use of trained 
dogs, to detect seal lairs before construction activities begin and (2) 
require construction crews to avoid seal lairs by at least 150 m.
    Response: As stated in the notice of the proposed IHA, AGDC plans 
to consult an experienced subsistence advisor for detection of seal 
lairs during construction activities that occur in winter. The advisor 
would survey areas within a buffer zone of Dock Head 4 (DH4) where 
water depth is greater than 3 m (10 ft) to identify potential ringed 
seal structures before activities begin. AGDC will avoid identified 
ringed seal structures by a minimum of 150 m (500 ft). The subsistence 
advisor and 150 m

[[Page 10677]]

buffer requirements have been added to the final IHA.
    Although trained dogs may be effective in identifying seals, there 
are a limited number of trained dogs available. Further, Alaska Native 
subsistence hunters have previously indicated that polar bears often 
follow the scent of the dogs to hunt those lairs (pers. comm., Sheyna 
Wisdom). Therefore, NMFS has not required the use of dogs for detection 
of seal lairs as suggested by the commenter.
    Comment 45: The Commission recommended that NMFS (1) reinforce that 
AGDC keep a running tally of the total takes, based on observed and 
extrapolated takes, for Level A and B harassment consistent with 
condition 4(h) of the final authorization, (2) include condition 
6(b)(xix) in the final authorization, and, if necessary, (3) provide 
AGDC a simple example of how to extrapolate takes to estimate the 
number of total takes.
    Response: The IHA indicates the number of takes authorized for each 
species. We agree that AGDC must ensure they do not exceed authorized 
takes, but do not concur with the recommendation to keep a running 
tally of extrapolated takes, as that is not necessary to ensure 
compliance with the IHA. CFR 216.108(c) requires a monitoring program 
to ``document or estimate the actual level of take.'' The final 
authorization includes measure 6(b)(xix) from the proposed IHA, though 
it is now measure 6(b)(xviii) and NMFS slightly modified it to clarify 
that rather than precisely extrapolating the observed take, AGDC will 
estimate potential exposures within the entire harassment zones based 
upon the number of observed exposures and the percentage of the Level A 
or Level B harassment zone that was not visible. NMFS is not 
prescribing an exact method for how AGDC should calculate the estimate 
of total potential takes.
    Comment 46: The Commission stated that it has raised ongoing 
concerns regarding NMFS's renewal process in the past few years, and 
notes that although NMFS responded generally to those concerns just 
recently, the Commission has not yet had time to consider fully whether 
and how it plans to respond. For purposes of its comment letter 
regarding this IHA, the Commission recommended that NMFS refrain from 
issuing a renewal for any authorization unless it is consistent with 
the procedural requirements specified in section 101(a)(5)(D)(iii) of 
the MMPA.
    Response: In prior responses to comments about IHA Renewals (e.g., 
84 FR 52464; October 02, 2019 and 85 FR 53342, August 28, 2020), NMFS 
has explained how the Renewal process, as implemented, is consistent 
with the statutory requirements contained in section 101(a)(5)(D) of 
the MMPA, provides additional efficiencies beyond the use of 
abbreviated notices, and further, promotes NMFS' goals of improving 
conservation of marine mammals and increasing efficiency in the MMPA 
compliance process. Therefore, we intend to continue implementing the 
Renewal process as a general matter.
    Comment 47: A commenter stated that NMFS should avoid a one-year 
renewal. It further stated that the potential extension and overlap of 
activities should be avoided.
    Response: The commenter does not state what it is referring to 
regarding ``overlap of activities'' that it suggests should be avoided 
by not issuing a renewal. 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.
    Comment 48: The Commission stated that NMFS' review processes 
(including its early review team meetings) are not adequately 
identifying and evaluating whether appropriate source levels, Level A 
harassment inputs, modeling methodologies, Level A and B harassment 
zones, densities, group size estimates, take estimates, shutdown zones, 
etc. have been proposed. The Commission recommended that NMFS make a 
concerted effort to review applications, Federal Register notices, and 
draft and final authorizations more thoroughly to minimize inaccuracies 
and ensure transparency for the public. In this instance, the 
information provided to the PRP was not accurate and the panel's review 
of AGDC's monitoring plan as required under section 
101(a)(5)(D)(ii)(III) may have been compromised. NMFS should provide 
the PRP with the revised Level A and B harassment zones and shutdown 
zones and allow for additional review and comments before issuing any 
IHA to AGDC. NMFS also should consider whether the inaccuracies are 
sufficient to warrant revision and re-publication of the proposed IHA.
    Response: While we acknowledge that errors are sometimes made, we 
disagree with the Commission's assertion that NMFS' review of the 
issues raised is broadly inadequate. Nonetheless, we continue to look 
for ways to improve our methods, analyses, and review process. 
Regarding the specific example raised, as explained in response to 
Comment 36, NMFS disagrees with the Commission regarding their 
recommended source level revision, and has not incorporated that 
recommendation into this final IHA. Therefore, the Level A and Level B 
harassment zones and the shutdown zones did not change, and the 
recommendation to provide the PRP with updated Level A and Level B 
harassment zones and shutdown zones is not necessary, nor is re-
publication of the proposed IHA.

Changes From the Proposed IHA to Final IHA

    The proposed IHA indicated that the authorization would be 
effective from July 1, 2022 to June 30, 2023. However, AGDC has since 
indicated that it does not expect to begin construction prior to July 
1, 2023; therefore, this final IHA is effective from July 1, 2023 to 
July 1, 2024.
    NMFS also added several mitigation and monitoring requirements to 
the final IHA in consideration of public comments received. NMFS added 
an explicit requirement for AGDC to abide by its POC. Additionally, 
NMFS added a measure that requires AGDC to consult an experienced 
subsistence advisor for detection of ringed seal lairs during winter 
construction activities, should they occur, and a measure requiring 
AGDC to implement a 150 m buffer between identified ringed seal lairs 
and construction activities. Both measures related to ringed seal lairs 
were discussed in the notice of the proposed IHA as measures that AGDC 
intended to implement, but had not been included in the proposed IHA. 
The final IHA also includes a requirement for aircraft to transit at a 
minimum altitude of 457 m (1,500 ft) or higher to the extent 
practicable, as well as a shutdown zone for screeding activities. Both 
the aircraft and screeding measures were included in the biological 
opinion, which AGDC is required to follow, as stated in both the 
proposed and final IHAs. The final IHA also includes a measure that 
requires vessels to transit landward of Cross Island during the 
entirety of the Nuiqsut whaling season (approximately August 25-
September 15, though the exact dates may change). This measure was 
already included in the POC.
    Since publication of the proposed IHA, through discussions with the 
AEWC and NMFS, AGDC has determined that it is practicable to increase 
the acoustic monitoring it will conduct. The final IHA requires AGDC to 
conduct SSV for pile driving, and includes additional requirements for 
an acoustic monitoring plan and acoustic monitoring report, including 
some reporting metrics recommended by the

[[Page 10678]]

PRP. The IHA allows NMFS to update the Level A and Level B harassment 
zones and shutdown zones, as appropriate, pending review and approval 
of the results of the acoustic monitoring. Additionally, the final IHA 
requires AGDC to deploy three hydrophones during construction in the 
open-water season, rather than just one, as stated in the proposed IHA. 
AGDC will deploy the hydrophones three days prior to the start of 
construction, and they will remain deployed through construction and 
for three days after the completion of construction. AGDC will still 
deploy just one hydrophone during the ice-cover season, should AGDC 
need conduct construction activities during that time. As stated in the 
proposed IHA, these hydrophones will be used for PAM of marine mammals, 
but will not be monitored in real time or used for mitigation. The 
final IHA also includes an additional reporting measure related to PAM 
for marine mammals which was suggested by the PRP, requiring AGDC to 
report marine mammal detection rates from PAM, summarized into daily or 
weekly periods. AGDC will include this information in its acoustic 
monitoring report, but is not required to submit this information to 
NMFS on a daily or weekly basis throughout the project duration.
    The final IHA includes several slight modifications to the take 
estimate. NMFS updated the Level A harassment take calculations for 
phocids and beluga whale by correcting the zone sizes used in the 
calculation. The updated calculation did not result in a change to the 
authorized Level A harassment take of beluga whale, but the authorized 
Level A harassment take of ringed seal, spotted seal, and bearded seal 
decreased. Additionally, NMFS updated the Level B harassment take 
estimate for beluga whales to account for an increased density due to 
the incorporation of recently-available 2019 ASAMM survey data (Clarke 
et al., 2020). The resulting Level B harassment take estimate for 
beluga whales increased to 55 Level B harassment takes in the final IHA 
from the 31 Level B harassment takes estimated in the proposed IHA. 
Please see the Estimated Take section for additional information on 
changes to the take estimate.
    Finally, since publication of the proposed IHA, NMFS published a 
proposed rule for the Designation of Critical Habitat for the Beringia 
Distinct Population Segment (DPS) of the Bearded Seal (86 FR 1433; 
January 8, 2021), and a revised proposed rule for the Designation of 
Critical Habitat for the Arctic Subspecies of the Ringed Seal (86 FR 
1452; January 8, 2021). Please see the Description of Marine Mammals in 
the Area of Specified Activities section for additional information.

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS' Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS' 
website (https://www.fisheries.noaa.gov/find-species). Additional 
information may be found in the Aerial Survey of Arctic Marine Mammals 
(ASAMM) reports, which are available online at https://www.fisheries.noaa.gov/alaska/marine-mammal-protection/aerial-surveys-arctic-marine-mammals.
    Table 2 lists all species or stocks for which take is expected and 
authorized for this action, and summarizes information related to the 
population or stock, including regulatory status under the MMPA and ESA 
and potential biological removal (PBR), where known. For taxonomy, we 
follow Committee on Taxonomy (2019). PBR is defined by the MMPA as the 
maximum number of animals, not including natural mortalities, that may 
be removed from a marine mammal stock while allowing that stock to 
reach or maintain its optimum sustainable population (as described in 
NMFS's SARs). While no mortality is anticipated or authorized here, PBR 
and annual serious injury and mortality from anthropogenic sources are 
included here as gross indicators of the status of the species and 
other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS' U.S. Pacific and Alaska SARs (e.g., Muto et al., 2019). All 
values presented in Table 2 are the most recent available at the time 
of publication and are available in the 2019 Pacific and Alaska SARs 
(Carretta et al., 2019; Muto et al., 2019) and draft 2020 Alaska SARs 
(published since publication of the proposed IHA and available online 
at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).

                                              Table 2--Species for Which Take Is Reasonably Likely to Occur
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    ESA/MMPA        Stock abundance
                                                                                    status;         (CV, Nmin, most                           Annual  M/
            Common name                Scientific name            Stock          strategic  (Y/    recent  abundance            PBR             SI \3\
                                                                                     N) \1\           survey) \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
Gray whale........................  Eschrichtius          Eastern North         -/-; N           26,960 (0.05,         801.................          131
                                     robustus.             Pacific.                               25,849, 2016).
Family Balaenidae:
    Bowhead whale.................  Balaena mysticetus..  Western Arctic......  E/D; Y           16,820 (0.052,        161.................           56
                                                                                                  16,100, 2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Beluga whale..................  Delphinapterus        Beaufort Sea........  -/-; N           39,258 (0.229, NA,    UND.................          102
                                     leucas.              Eastern Chukchi Sea.  -/-; N            1992).               178.................           55
                                                                                                 13,305 (0.51, 8,875,
                                                                                                  2017).
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 10679]]

 
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
    Ringed seal...................  Phoca (pusa) hispida  Arctic..............  T/D; Y           see SAR (see SAR,     6,459...............          863
                                                                                                  see SAR, 2012-2013.
    Spotted seal..................  Phoca largha........  Bering..............  -/-; N           461,625 (see SAR,     25,394..............        5,254
                                                                                                  423,237, 2013).
    Bearded seal..................  Erignathus barbatus.  Beringia............  T/D; Y           see SAR (see SAR,     See SAR.............        6,709
                                                                                                  see SAR, 2012-2013.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike).

    As indicated above, all six species (with seven managed stocks) in 
Table 2 temporally and spatially co-occur with the activity to the 
degree that take is reasonably likely to occur, and we have authorized 
take. While a harbor porpoise was sighted in the 2017 ASAMM survey 
(Clarke et al., 2018), the spatial occurrence of harbor porpoise is 
such that take is not expected to occur, and they are not discussed 
further beyond the explanation provided here. Harbor porpoise (Phocoena 
phocoena) are considered to be extremely rare in the Beaufort Sea, 
particularly in the project area (Megan Ferguson, pers. comm., November 
2019).
    In addition, the polar bear may be found in Prudhoe Bay. However, 
polar bears are managed by the U.S. Fish and Wildlife Service and are 
not considered further in this document.
    A detailed description of the of the species likely to be affected 
by AGDC's project, including brief introductions to the species and 
relevant stocks as well as available information regarding population 
trends and threats, and information regarding local occurrence, were 
provided in the Federal Register notice for the proposed IHA (85 FR 
43382; July 16, 2020); since that time, we are not aware of any changes 
in the status of these species and stocks, other than the proposed 
critical habitat designations under the ESA for the Beringia DPS of the 
Bearded Seal and the Arctic Subspecies of the Ringed Seal, discussed 
below; therefore, other than the critical habitat discussion, detailed 
descriptions are not provided here. Please refer to that Federal 
Register notice for these descriptions. Please also refer to NMFS' 
website (https://www.fisheries.noaa.gov/find-species) for generalized 
species accounts.

Critical Habitat

    On January 8, 2021, NMFS published a proposed rule for the 
Designation of Critical Habitat for the Beringia DPS of the Bearded 
Seal (86 FR 1433). NMFS identified the physical and biological features 
essential to the conservation of the species: (1) Sea ice habitat 
suitable for whelping and nursing, which is defined as areas with 
waters 200 m or less in depth containing pack ice of at least 25 
percent concentration and providing bearded seals access to those 
waters from the ice; (2) sea ice habitat suitable as a platform for 
molting, which is defined as areas with waters 200 m or less in depth 
containing pack ice of at least 15 percent concentration and providing 
bearded seals access to those waters from the ice; (3) primary prey 
resources to support bearded seals in waters 200 m or less in depth: 
benthic organisms, including epifaunal and infaunal invertebrates, and 
demersal and schooling pelagic fishes; and (4) acoustic conditions that 
allow for effective communication by bearded seals for breeding 
purposes within waters used by breeding bearded seals. The proposed 
designation under the ESA comprises a specific area of marine habitat 
in the Bering, Chukchi, and Beaufort seas, extending from mean lower 
low water (MLLW) to a depth of 200 m within the U.S. Exclusive Economic 
Zone (EEZ), including this construction project's Level A and Level B 
harassment zones (see 86 FR 1433, January 8, 2021 for additional detail 
and a map of the proposed area).
    On January 8, 2021, NMFS also published a revised proposed rule for 
the Designation of Critical Habitat for the Arctic Subspecies of the 
Ringed Seal (86 FR 1452). This proposed rule revises NMFS' December 9, 
2014, proposed designation of critical habitat for the Arctic 
subspecies of the ringed seal under the ESA. NMFS identified the 
physical and biological features essential to the conservation of the 
species: (1) Snow-covered sea ice habitat suitable for the formation 
and maintenance of subnivean birth lairs used for sheltering pups 
during whelping and nursing, which is defined as areas of seasonal 
landfast (shorefast) ice and dense, stable pack ice, excluding any 
bottom-fast ice extending seaward from the coastline (typically in 
waters less than 2 m deep), that have undergone deformation and contain 
snowdrifts of sufficient depth, typically at least 54 cm deep; (2) Sea 
ice habitat suitable as a platform for basking and molting, which is 
defined as areas containing sea ice of 15 percent or more 
concentration, excluding any bottom-fast ice extending seaward from the 
coastline (typically in waters less than 2 m deep); and (3) Primary 
prey resources to support Arctic ringed seals, which are defined to be 
Arctic cod, saffron cod, shrimps, and amphipods. The revised proposed 
designation comprises a specific area of marine habitat in the Bering, 
Chukchi, and Beaufort seas, extending from MLLW to an offshore limit 
within the U.S. EEZ, including this construction project's Level A and 
Level B harassment zones (see 86 FR 1452; January 8, 2021 for 
additional detail and a map of the proposed area).

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from AGDC's construction activities 
have the

[[Page 10680]]

potential to result in behavioral harassment of marine mammals in the 
vicinity of the survey area. The notice of proposed IHA (85 FR 43382; 
July 16, 2020) included a discussion of the effects of anthropogenic 
noise on marine mammals and the potential effects of underwater noise 
from AGDC's construction activities on marine mammals and their 
habitat. That information and analysis is incorporated by reference 
into this final IHA determination and is not repeated here; please 
refer to the notice of proposed IHA (85 FR 43382; July 16, 2020).

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized through this IHA, which will inform both NMFS' consideration 
of ``small numbers'' and the negligible impact determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment). Authorized takes would 
primarily be by Level B harassment, as use of the acoustic source 
(i.e., vibratory and impact pile driving) has the potential to result 
in disruption of behavioral patterns for individual marine mammals. 
There is also some potential for auditory injury (Level A harassment) 
to result, primarily for phocids, due to their lack of visibility and 
the size of the Level A harassment zones. Auditory injury is unlikely 
to occur to cetaceans for the reasons described in the Take Calculation 
and Estimation section, below. The mitigation and monitoring measures 
are expected to minimize the severity of the taking to the extent 
practicable.
    As described previously, no mortality is anticipated or authorized 
for this activity. Below we describe how the take is estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
and the number of days of activities. We note that while these basic 
factors can contribute to a basic calculation to provide an initial 
prediction of takes, additional information that can qualitatively 
inform take estimates is also sometimes available (e.g., previous 
monitoring results or average group size). Below, we describe the 
factors considered here in more detail and present the take estimate.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2012). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 [mu]Pa (rms) for continuous (e.g., 
vibratory pile-driving, drilling) and above 160 dB re 1 [mu]Pa (rms) 
for non-explosive impulsive (e.g., seismic airguns) or intermittent 
(e.g., scientific sonar) sources.
    AGDC's construction activity includes the use of continuous 
(vibratory pile driving) and impulsive (impact pile driving) sources, 
and therefore the 120 and 160 dB re 1 [mu]Pa (rms) are applicable.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Version 2.0) (Technical Guidance, 2018) identifies dual 
criteria to assess auditory injury (Level A harassment) to five 
different marine mammal groups (based on hearing sensitivity) as a 
result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). AGDC's construction activity includes the 
use of impulsive (impact pile driving) and non-impulsive (vibratory 
pile driving) sources.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                    PTS onset acoustic thresholds *  (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.

[[Page 10681]]

 
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has
  a reference value of 1[mu]Pa\2\s. In this Table, thresholds are abbreviated to reflect American National
  Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
  frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
  being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
  hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
  designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
  that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
  exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
  is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the planned project. 
Marine mammals are expected to be affected via sound generated by the 
primary components of the project (i.e., vibratory pile driving and 
removal). The maximum (underwater) area ensonified above the thresholds 
for behavioral harassment referenced above is 67.7 km\2\ (26.1 mi\2\), 
and the calculated distance to the farthest behavioral isopleth is 
approximately 4.6 km (2.9 mi).
    The project includes vibratory pile installation and removal and 
impact pile installation. Source levels for these activities are based 
on reviews of measurements of the same or similar types and dimensions 
of piles available in the literature. Source levels for each pile size 
and activity are presented in Table 4. Source levels for vibratory 
installation and removal of piles of the same diameter are assumed to 
be the same.

                                                      Table 4--Sound Source Levels for Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                        Source level  (at 10m)
        Pile size and type               Hammer type       ------------------------------------------------               Literature source
                                                                SPLrms           Peak             SEL
--------------------------------------------------------------------------------------------------------------------------------------------------------
11.5-inch H-Pile.................  Impact.................             183             200             170  Caltrans 2015 (12-in H-Pile).
14-inch H-Pile...................  Impact.................             187             208             177  Caltrans 2015 (14-in H-Pile).
                                   Vibratory..............             150             160             150  Caltrans 2015 (12-in H-Pile).
48-inch Pipe Pile................  Impact.................             195             210             185  Caltrans 2015 (60-in CISS Pile).
Sheet Piles (19.69-inch and 25-    Vibratory..............             160             175             160  Caltrans 2015 (AZ Sheet Pile).
 inch).
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Transmission loss (TL) is the decrease in acoustic intensity as an 
acoustic pressure wave propagates out from a source. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. The general formula for underwater TL is:

TL = B * Log10 (R1/R2),

where
TL = transmission loss in dB
B = transmission loss coefficient
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement

    Absent site-specific acoustical monitoring with differing measured 
transmission loss, a practical spreading value of 15 is used as the 
transmission loss coefficient in the above formula. Project and site-
specific transmission loss data for the Prudhoe Bay portion of AGDC's 
AK LNG project are not available; therefore, the default coefficient of 
15 is used to determine the distances to the Level A and Level B 
harassment thresholds. However, as discussed in the Monitoring and 
Reporting section, AGDC will conduct SSV for pile driving. NMFS may 
adjust the shutdown zones and revise the Level A and Level B harassment 
zones, as appropriate, pending review and approval of the results of 
acoustic monitoring.
    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that ensonified area/volume could be more 
technically challenging to predict because of the duration component in 
the new thresholds, we developed a User Spreadsheet that includes tools 
to help predict a simple isopleth that can be used in conjunction with 
marine mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which may result in some degree of 
overestimate of Level A harassment take. However, these tools offer the 
best way to predict appropriate isopleths when more sophisticated 3D 
modeling methods are not available, and NMFS continues to develop ways 
to quantitatively refine these tools, and will qualitatively address 
the output where appropriate. For stationary sources such as pile 
driving, NMFS User Spreadsheet predicts the distance at which, if a 
marine mammal remained at that distance the whole duration of the 
activity, it would incur PTS. Inputs used in the User Spreadsheet, and 
the resulting isopleths are reported below.

                              Table 5--User Spreadsheet Input Parameters Used for Calculating Level A Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                   19.69-inch sheet      25-inch sheet
                                   11.5-inch H-pile     14-inch H-pile      14-inch H-pile     48-inch pipe pile         piles               piles
--------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used............  E.1) Impact pile    E.1) Impact pile    A.1) Vibratory      E.1) Impact pile    A.1) Vibratory      A.1) Vibratory
                                   driving.            driving.            pile driving.       driving.            pile driving.       pile driving.
Weighting Factor Adjustment       2.................  2.................  2.5...............  2.................  2.5...............  2.5.
 (kHz).
Source Level....................  170 dB SEL........  177 dB SEL........  150 SPLrms........  185 dB SEL........  160 SPLrms........  160 SPLrms.
Number of piles within 24-h       26.09 \b\.........  4.................  8.................  1.25..............  15.24 \b\.........  12.
 period \a\.
Duration to drive a single pile   ..................  ..................  15................  ..................  18.9..............  24.
 (minutes).

[[Page 10682]]

 
Number of strikes per pile......  1,000.............  1,000.............  ..................  1,000.............  ..................  ..................
Propagation (xLogR).............  15................  15................  15................  15................  15................  15.
Distance from source level        10................  10................  10................  10................  10................  10.
 measurement (meters).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ These estimates include contingencies for weather, equipment, work flow, and other factors that affect the number of piles per day, and are assumed
  to be a maximum anticipated per day. Given that AGDC plans to pile drive up to 24 hours per day, it is appropriate to assume that the number of piles
  installed within the 24-hour period may not be a whole number.
\b\ These averages assume that AGDC will drive 11.5-inch H-piles and sheet piles at a rate of 25 feet per day.


                    Table 6--Calculated Distances to Level A and Level B Harassment Isopleths
----------------------------------------------------------------------------------------------------------------
                                                           Level A harassment zone  (m)               Level B
           Activity               Hammer type    ------------------------------------------------   harassment
                                                   LF cetaceans    MF cetaceans       Phocids        zone  (m)
----------------------------------------------------------------------------------------------------------------
11.5-inch H-Pile.............  Impact...........           1,194              43             639             341
14-inch H-Pile...............  Impact...........           1,002              36             536             631
                               Vibratory........               2              <1               1           1,000
48-inch Pipe Pile............  Impact...........           1,575              56             843           2,154
19.69-inch Sheet Piles.......  Vibratory........              17               2              10           4,642
25-inch Sheet Piles..........  Vibratory........              17               2              10           4,642
----------------------------------------------------------------------------------------------------------------

    Level A harassment zones are typically smaller than Level B 
harassment zones. However, in rare cases such as the impact pile 
driving of the 11.5-inch and 14-inch H-piles in AGDC's project, the 
calculated Level A harassment isopleth is greater than the calculated 
Level B harassment isopleth. Calculation of Level A harassment 
isopleths include a duration component, which in the case of impact 
pile driving, is estimated through the total number of daily strikes 
and the associated pulse duration. For a stationary sound source such 
as impact pile driving, we assume here that an animal is exposed to all 
of the strikes expected within a 24-hour period. Calculation of a Level 
B harassment zone does not include a duration component. Depending on 
the duration included in the calculation, the calculated Level A 
harassment isopleths can be larger than the calculated Level B 
harassment isopleth for the same activity.

Marine Mammal Occurrence

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations.
    Each fall and summer, NMFS and BOEM conduct an aerial survey in the 
Arctic, the ASAMM surveys (Clarke et al., 2012, 2013a, 2014, 2015, 
2017a, 2017b, 2018, 2019, 2020). The goal of these surveys is to 
document the distribution and relative abundance of bowhead, gray, 
right, fin and beluga whales and other marine mammals in areas of 
potential oil and natural gas exploration, development, and production 
activities in the Alaskan Beaufort and northeastern Chukchi Seas. 
Traditionally, only fall surveys were conducted but, in 2011, the first 
dedicated summer survey effort began in the ASAMM Beaufort Sea study 
area. AGDC used these ASAMM surveys as the data source to estimate 
seasonal densities of cetaceans (bowhead, gray and beluga whales) in 
the project area. The ASAMM surveys are conducted within blocks that 
overlay the Beaufort and Chukchi Seas oil and gas lease sale areas 
offshore of Alaska (Figure 16 in AGDC's application), and provide 
sighting data for bowhead, gray, and beluga whales during summer and 
fall months. During the summer and fall, NMFS observed for marine 
mammals on effort for 13,484 km and 12,846 km, respectively, from 2011 
through 2018, and an additional 1643 km during summer 2019 and 2055 km 
during fall 2019. Data from those surveys are used for this analysis. 
We note that the Prudhoe Bay portion of the AK LNG project is in ASAMM 
survey Block 1a. The inshore boundary of Block 1 terminates at the 
McClure Island group, and it was not until 2016 that on-effort surveys 
began inside the McClure Island group (Block 1a; including Prudhoe Bay) 
since bowhead whales, the focus of the surveys, are not likely to enter 
this area given its shallow depth. However, no bowhead whales and only 
one beluga whale have been observed in Block 1a (including Prudhoe 
Bay). Therefore, the density estimates provided here, calculated using 
data from block 1, are likely an overestimate because they rely on 
offshore surveys where marine mammals are more likely to be present.
Bowhead Whale
    AGDC calculated density estimates for bowhead whale by dividing the 
average number of whales observed per km of transect effort from 2011 
to 2018 in ASAMM Block 1 (whales/km in Table 7) by two times the 
effective strip width (ESW) to encompass both sides of the transect 
line (whales per km/(2 x ESW). The ESW for bowhead whales from the Aero 
Commander aircraft is 1.15 km (0.71 mi) (Ferguson and Clarke 2013). 
Therefore, the summer density estimate is 0.005 bowhead whales/km\2\, 
and the fall density estimate is 0.017 bowhead whales/km\2\. The 
resulting densities are expected to be overestimates for the AK LNG 
analysis because the data is based on sighting effort outside of the 
barrier islands, and bowhead whales rarely occur within the barrier 
islands. However, AGDC conservatively used the higher fall density to 
estimate potential Level B harassment takes, and NMFS concurs. (Note 
that inclusion of the 2019 ASAMM surveys reduces the fall bowhead 
density to 0.016 bowhead whales/km\2\. However, NMFS has conservatively 
used the higher density included in the proposed IHA to calculate Level 
B harassment take of bowhead whale, as described in the Take 
Calculation and Estimation section, below.)
    As noted in the Description of Marine Mammals in the Area of 
Specified Activities section of the proposed IHA (85 FR 43382; July 16, 
2020), we do not expect bowhead whales to be present

[[Page 10683]]

during AGDC's winter/spring contingency pile driving period.

                                   Table 7--Bowhead Whale Sighting Data From 2011 Through 2019 and Resulting Densities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Summer                                                  Fall
                                           -------------------------------------------------------------------------------------------------------------
                   Year                      Number  of    Transect                                 Number  of    Transect
                                               whales       effort     Whales/km    Whales/km 2 a     whales       effort     Whales/km    Whales/km 2 a
                                              sighted        (km)                                    sighted        (km)
--------------------------------------------------------------------------------------------------------------------------------------------------------
2011......................................            1          346        0.003           0.001           24        1,130        0.021           0.009
2012......................................            5        1,493        0.003           0.001           17        1,696        0.010           0.004
2013......................................           21        1,582        0.013           0.006           21        1,121        0.019           0.008
2014......................................           17        1,393        0.012           0.005           79        1,538        0.051           0.022
2015......................................           15        1,262        0.012           0.005           17        1,663        0.010           0.004
2016......................................           97        1,914        0.051           0.022           23        2,360        0.010           0.004
2017......................................            8        3,003        0.003           0.001          255        1,803        0.141           0.061
2018......................................            2        2,491        0.001          0.0004           69        1,535        0.045           0.020
2019 \c\..................................            6        1,643        0.004           0.002           45        2,055        0.022           0.010
                                           -------------------------------------------------------------------------------------------------------------
    Total.................................          166       13,484    \b\ 0.012       \b\ 0.005          505       12,846    \b\ 0.039       \b\ 0.017
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Calculated using an effective strip width of 1.15 km.
\b\ Value represents average, not total, across all years.
\c\ Note that inclusion of the new 2019 data results in a lower fall bowhead whale density (0.016). NMFS has conservatively used the higher fall density
  included in the proposed IHA (85 FR 43382; July 16, 2020) to calculate Level B harassment take of bowhead whale. Therefore, the 2019 data is not
  included in calculations in the ``TOTAL'' row.

Gray Whale
    Gray whale sightings in the Beaufort Sea have increased in recent 
years; however, encounters are still infrequent. AGDC calculated 
density estimates for gray whale by dividing the average number of 
whales observed per km of transect effort (whales/km in Table 8) by two 
times the ESW to encompass both sides of the transect line (whales per 
km/(2 x ESW). The ESW for gray whales from the Aero Commander aircraft 
is 1.20 km (0.75 mi) (Ferguson and Clarke 2013). Therefore, the summer 
and fall density estimates are both 0.00003 gray whales/km\2\. The 
resulting densities are expected to be overestimates for the AK LNG 
analysis because the data is based on sighting effort outside of the 
barrier islands, and gray whales rarely occur within the barrier 
islands as evidenced by Block 1a ASAMM surveys.
    Similar to bowhead whale described above, gray whale densities were 
calculated using ASAMM survey data from 2011 to 2018. Inclusion of the 
2019 ASAMM surveys reduces the summer gray whale density to 0.000028 
gray whales/km\2\. However, NMFS has conservatively used the slightly 
higher density included in the proposed IHA to calculate Level B 
harassment take of gray whale, as described in the Take Calculation and 
Estimation section, below.
    As noted in the Description of Marine Mammals in the Area of 
Specified Activities section of the proposed IHA (85 FR 43382; July 16, 
2020), we do not expect gray whales to be present during AGDC's winter/
spring contingency pile driving period.

                                    Table 8--Gray Whale Sighting Data From 2011 Through 2019 and Resulting Densities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Summer                                                  Fall
                                           -------------------------------------------------------------------------------------------------------------
                   Year                      Number  of    Transect                                 Number  of    Transect
                                               whales       effort     Whales/km    Whales/km 2 a     whales       effort     Whales/km    Whales/km 2 a
                                              sighted        (km)                                    sighted        (km)
--------------------------------------------------------------------------------------------------------------------------------------------------------
2011......................................            0          346            0               0            0        1,130            0               0
2012......................................            0        1,493            0               0            0        1,696            0               0
2013......................................            0        1,582            0               0            0        1,121            0               0
2014......................................            0        1,393            0               0            1        1,538       0.0007          0.0003
2015......................................            0        1,262            0               0            0        1,663            0               0
2016......................................            1        1,914        0.003           0.001            0        2,360            0               0
2017......................................            0        3,003            0               0            0        1,803            0               0
2018......................................            0        2,491            0               0            0        1,535            0               0
2019......................................            0        1,643            0               0            0        2,055            0               0
                                           -------------------------------------------------------------------------------------------------------------
    Total.................................            1       13,484  \b\ 0.00007     \b\ 0.00003            1       12,846  \b\ 0.00008     \b\ 0.00003
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Calculated using an effective strip width of 1.20 km.
\b\ Value represents average, not total, across all years.
\c\ Note that inclusion of the new 2019 data results in a lower fall bowhead whale density (0.016). NMFS has conservatively used the higher fall density
  included in the proposed IHA to calculate Level B harassment take of bowhead whale. Therefore, the 2019 data is not included in calculations in the
  ``TOTAL'' row.

Beluga Whale
    AGDC calculated beluga densities for survey block 1 (the area 
offshore from the McClure Island group) using ASAMM data collected from 
2014-2018. Beluga sighting data was included in surveys from 2011 to 
2013; however, this data is only summarized by depth zone, rather than 
by survey block. Therefore, the National Marine Mammal Laboratory 
(Megan Ferguson, pers.

[[Page 10684]]

comm., November 18, 2019), advised NMFS and AGDC to calculate beluga 
whale density using the 2014-2018 ASAMM data, as it is more recent and 
incorporates more years. Density estimates for beluga whale were 
calculated by dividing the average number of whales observed per km of 
transect effort (whales/km in Table 9) by two times the effective strip 
width to encompass both sides of the transect line (whales per km/(2 x 
ESW). The ESW for beluga whales from the Aero Commander aircraft is 
0.614 km (0.38 mi) (Ferguson and Clarke 2013). Using the 2014 to 2018 
data, the resulting summer density estimate included in the proposed 
IHA was 0.005 beluga whales/km\2\, and the fall density estimate 
included in the proposed IHA was 0.001 beluga whales/km\2\. AGDC 
conservatively used the higher summer density to estimate potential 
Level B harassment takes, and NMFS concurred for the proposed IHA (85 
FR 43382; July 16, 2020).
    Inclusion of the recently-available 2019 ASAMM survey results for 
beluga whale in block 1 increased the summer beluga whale density to 
0.009 whales/km\2\ since publication of the proposed IHA. Therefore, as 
described further in the Take Calculation and Estimation section, 
below, NMFS used the updated summer density to calculate beluga whale 
Level A and Level B harassment take.
    The resulting densities are expected to be overestimates for the AK 
LNG analysis 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.
    As noted in the Description of Marine Mammals in the Area of 
Specified Activities section of the proposed IHA (85 FR 43382; July 16, 
2020), we do not expect beluga whales to be present during AGDC's 
winter/spring contingency pile driving period.

                                   Table 9--Beluga Whale Sighting Data From 2011 Through 2019 and Resulting Densities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Summer                                                  Fall
                                           -------------------------------------------------------------------------------------------------------------
                   Year                      Number  of    Transect                                 Number  of    Transect
                                               whales       effort     Whales/km    Whales/km 2 a     whales       effort     Whales/km    Whales/km 2 a
                                              sighted        (km)                                    sighted        (km)
--------------------------------------------------------------------------------------------------------------------------------------------------------
2014......................................           13        1,393        0.009           0.008            9        1,538        0.006           0.005
2015......................................           37        1,262        0.029           0.024            3        1,663        0.002           0.001
2016......................................            0        1,914            0               0            1        2,360       0.0004          0.0003
2017......................................            4        3,003        0.001           0.001            0        1,803            0               0
2018......................................            6        2,491        0.002           0.002            0        1,535            0               0
2019 \c\..................................           63        1,643        0.038           0.031            1        2,055       0.0005          0.0004
                                           -------------------------------------------------------------------------------------------------------------
    Total.................................           60       11,706    \b\ 0.012       \b\ 0.009           13       10,954    \b\ 0.001       \b\ 0.001
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Calculated using an effective strip width of 0.614 km.
\b\ Value represents average, not total, across all years.
\c\ Values included in the updated ``TOTAL'' row.

Ringed Seal
    Ringed seals are the most abundant species in the project area. 
They haul out on the ice to molt between late May and early June, and 
spring aerial surveys provide the most comprehensive density estimates 
available. Industry monitoring programs for the construction of the 
Northstar production facility conducted spring aerial surveys in the 
area surrounding West Dock from 1997 to 2002 (Frost et al., 2002; 
Moulten et al., 2002b; Moulton et al., 2005; Richardson and Williams, 
2003). Spring surveys are expected to provide the best ringed seal 
density information, as the greatest percentage of seals have abandoned 
their lairs and are hauled out on the ice (Kelly et al., 2010). 
Densities were consistently very low in areas where the water depth was 
less than 10 ft. (3 m), and only sightings observed in water depths 
greater than 10 ft. (3 m) have been included in the density 
calculations (Moulton et al., 2002a, Moulton et al., 2002b, Richardson 
and Williams, 2003). The average observed spring ringed seal density 
from this monitoring effort was 0.548 seals/km\2\ (Table 10). These 
densities are not corrected for unobserved animals, and therefore may 
result in an underestimated density. However, NMFS and AGDC do not 
expect this to be a concern, given that the density calculations 
conservatively only included 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 10 ft at the project site), and therefore 
densities are likely to be lower.

  Table 10--Ringed Seal Densities Estimated From Spring Aerial Surveys
                       Conducted From 1997 to 2002
------------------------------------------------------------------------
                                                               Density
                            Year                               (seals/
                                                                km\2\)
------------------------------------------------------------------------
1997.......................................................         0.43
1998.......................................................         0.39
1999.......................................................         0.63
2000.......................................................         0.47
2001.......................................................         0.54
2002.......................................................         0.83
Average....................................................        0.548
------------------------------------------------------------------------


[[Page 10685]]

    In order to generate a summer density, as AGDC expects that the 
majority of their work will occur during the summer, we first began 
with the spring density. Summer densities in the project area are 
expected to significantly decrease as ringed seals range considerable 
distances during the open water season. Summer density was estimated to 
be 50 percent of the spring density (0.548 seals/km\2\), resulting in a 
summer density estimate of 0.274 ringed seals/km\2\. Like summer 
density estimates, fall density data are limited. Ringed seals remain 
in the water through the fall and into the winter. Given the lack of 
data, fall density is assumed the same as the summer density of 0.274 
ringed seals/km\2\.
    During the winter months, ringed seals create subnivean lairs and 
maintain breathing holes in the landfast ice. Tagging data suggest that 
ringed seals utilize multiple lairs and Kelly et al. (1986) determined 
that, on average, one seal used 2.85 lairs, although the authors 
suggested that this is likely an underestimate. Density estimates for 
the number of ringed seal ice structures have been calculated (Frost 
and Burns 1989; Kelly et al. 1986; Williams et al. 2001), and the 
average density of ice structures from these reports is 1.58/km\2\.
    To estimate ringed seal density in the winter, the average ice 
structure density (1.58/km\2\) was divided by the average number of 
structures used by the seals (2.85 structures). The estimated density 
is 0.509 ringed seals/km\2\ in the winter; however, this is likely an 
overestimate as the average number of ice structures utilized is 
thought to be an underestimate (Kelly et al., 1986).
    While more recent ASAMM surveys have been conducted in the project 
area (2016-2019), these surveys did not identify observed pinnipeds to 
species, and therefore were not used to calculate take of pinnipeds.

   Table 11--Ringed Seal Ice Structure Density in the Vicinity of the
                              Project Area
------------------------------------------------------------------------
                                  Ice structure
                                     density
              Year                 (structures            Source
                                   per km\2\)
------------------------------------------------------------------------
1982...........................             3.6  Frost and Burns 1989.
1983...........................            0.81  Kelly et al., 1986.
1999...........................            0.71  Williams et al., 2001.
2000...........................             1.2  Williams et al., 2001.
Average Density................           1.58.  .......................
------------------------------------------------------------------------

    Given that AGDC will only pile drive during the winter if they are 
unable to complete the work during the summer and fall open water 
season, AGDC estimated ringed seal takes using summer densities, rather 
than winter. NMFS concurs with this approach.
Spotted Seal
    The spotted seal occurs in the Beaufort Sea in small numbers during 
the summer open water period. At the onset of freeze-up in the fall, 
spotted seals return to the Chukchi and then Bering Sea to spend the 
winter and spring. As such, we do not expect spotted seals to occur in 
the project area during AGDC's winter/spring contingency period.
    Only a few of the studies referenced in calculating the ringed seal 
densities also include data for spotted seals. Given the limited 
spotted seal data, NMFS expects that relying on this data may result in 
an underestimate, and that it is more conservative to calculate the 
spotted seal density as a proportion of the ringed seal density. 
Therefore, summer spotted seal density was estimated as a proportion of 
the ringed seal summer density based on the percentage of pinniped 
sightings observed during monitoring projects in the region (Harris et 
al., 2001; Aerts et al., 2008; Hauser et al., 2008; HDR 2012). Spotted 
seals comprised 20 percent of the pinniped sightings during these 
monitoring efforts. Therefore, summer spotted seal density was 
calculated as 20 percent of the ringed seal density of 0.274 seals/
km\2\. This results in an estimated spotted seal summer density of 
0.055 seals/km\2\.
Bearded Seal
    The majority of bearded seals spend the winter and spring in the 
Chukchi and Bering seas; however, some remain in the Beaufort Sea year-
round. A reliable population estimate for the bearded seal stock is not 
available, and occurrence in the Beaufort Sea is less known than that 
in the Bering Sea. Spring aerial surveys conducted as part of industry 
monitoring for the Northstar production facility provide limited 
sighting numbers from 1999-2002 (Moulton et al., 2000, Moulton et al., 
2001, Moulton et al., 2002a, Moulton et al., 2003). During the 4 years 
of survey, an average of 11.75 bearded seals were observed during 
3,997.5 km\2\ of effort. Using this data, winter and spring density are 
estimated to be 0.003 bearded seals/km\2\.
    Bearded seals occur in the Beaufort Sea more frequently during the 
open water season, rather than other parts of the year. Only a few of 
the studies referenced in calculating the ringed seal densities also 
include data for bearded seals. Given the limited bearded seal data, 
NMFS expects that relying on this data may result in an underestimate, 
and that it is more conservative to calculate the bearded seal density 
as a proportion of the ringed seal density. Therefore, summer density 
was estimated as a proportion of the ringed seal summer density based 
on the percentage of pinniped sightings observed during monitoring 
projects in the region (Harris et al., 2001; Aerts et al., 2008; Hauser 
et al., 2008; HDR 2012). Bearded seals comprised 17 percent of the 
pinniped sightings during these monitoring efforts. Therefore, summer 
bearded seal density was calculated as 17 percent of the ringed seal 
density of 0.274 seals/km\2\. This results in an estimated bearded seal 
summer density of 0.047 seals/km\2\. The same estimate is assumed for 
bearded seal fall density.
    As noted in the Description of Marine Mammals in the Area of 
Specified Activities section and in Table 12, bearded seals could 
potentially occur in the project area during AGDC's winter/spring 
contingency period. However, we would expect very few, if any, bearded 
seals to be present during this time. In consideration of this species 
presence information, and AGDC's plan to conduct most construction 
during the open-water season, NMFS used the summer density in the take 
calculation described below.

[[Page 10686]]



                      Table 12--Marine Mammal Densities in the Geographic Region by Season
----------------------------------------------------------------------------------------------------------------
                                                   Winter  (Nov-   Spring  (Apr-   Summer  (Jul-   Fall  (Sept-
                     Species                           Mar)          Jun) \a\          Aug)            Oct)
----------------------------------------------------------------------------------------------------------------
Bowhead Whale...................................               0               0           0.005           0.017
Gray Whale......................................               0               0         0.00003         0.00003
Beluga Whale\b\.................................               0               0           0.009           0.001
Ringed Seal.....................................           0.507           0.548           0.274           0.274
Spotted Seal....................................               0               0           0.055               0
Bearded Seal....................................           0.003           0.003           0.047           0.047
----------------------------------------------------------------------------------------------------------------
\a\ AGDC's pile driving contingency period extends from late February to April 2024, however, very little if any
  pile driving is likely to occur in April.
\b\ As noted above, the beluga whale densities were updated to include 2019 ASAMM survey data. (Clarke et al.,
  2020).

Take Calculation and Estimation

    In this section, we describe how the information provided above is 
brought together to produce a quantitative take estimate.
    To estimate Level A and Level B harassment takes, AGDC first 
multiplied the area (km\2\) estimated to be ensonified above the Level 
A or Level B harassment thresholds for each species, respectively, for 
pile driving (and removal) of each pile size and hammer type by the 
duration (days) of that activity in that season by the seasonal density 
for each species (number of animals/km\2\). NMFS generally concurs 
with, and has adopted this method, with the exception of the estimated 
duration of the activity, as described below.
    AGDC expects that construction will likely be completed during the 
open-water construction season. AGDC calculated that the construction 
will require approximately 164 days of in-water work; however, this 
estimate does not take into account that different pile types would be 
installed on the same day, therefore reducing the total number of pile 
driving days. Therefore, NMFS expects that the take calculation using 
AGDC's method described above overestimates take. Taking into 
consideration the number of calendar days, construction occurring 6 
days per week, and no work occurring on days during the whaling season, 
there are 123 days in the months of July through October on which the 
work is expected to occur (75 percent of the 164 days used to inform 
the take estimate in AGDC's application). As such, NMFS is authorizing 
75 percent of the take estimate calculated by AGDC for each species 
(except for Level A harassment take of bowhead whales and beluga 
whales, and Level B harassment of gray whales as noted below).
    NMFS recognizes that AGDC may work for a short time 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. Additionally, we 
recognize that ringed seals may be present in ice lairs during the 
contingency period. However, AGDC must initiate pile driving prior to 
March 1, as described in the Mitigation Measures section. Initiating 
pile driving before March 1 is expected to discourage seals from 
establishing birthing lairs near pile driving. As such, we expect that 
this measure will eliminate the potential for physical injury to ringed 
seals during this period. Therefore, NMFS expects that the take 
estimate described herein is reasonable even if AGDC must pile drive 
during their contingency period.
    NMFS calculated take using summer densities for all species except 
for bowhead whale. For bowhead whales, NMFS conservatively calculated 
take using the fall density.
    For bowhead whale, including the 2019 ASAMM surveys decreases the 
fall bowhead density to 0.016 bowhead whales/km\2\. However, NMFS has 
conservatively used the higher density included in the proposed IHA to 
calculate Level B harassment take of bowhead whale. Using the lower 
density results in an estimate of 103 Level B harassment takes of 
bowhead, which NMFS considers to be a negligible difference, though 
less conservative.
    For gray whale, including the 2019 ASAMM survey data decreases the 
summer density to 0.000028 gray whales/km\2\. Using this lower density 
results in a calculated take estimate of 0.18 takes by Level B 
harassment of gray whale, but in consideration of group size, the take 
estimate remains 2 takes by Level B harassment, as included in the 
proposed IHA.
    For beluga whale, including the 2019 ASAMM survey data increases 
the summer density to 0.0009 beluga whales/km\2\, which significantly 
increases the estimated Level A and Level B harassment takes. 
Therefore, NMFS recalculated the Level A and Level B harassment take 
estimates using this new density. The updated estimates are included in 
Table 14 and Table 15.
    As noted in Table 15, in the proposed IHA (85 FR 43382; July 16, 
2020), Level A harassment takes for beluga whale and phocids were 
erroneously calculated using the LF cetacean Level A harassment zone 
sizes. The calculations in Table 15 and in the final IHA reflect the 
corrected estimated Level A harassment take for phocids and beluga 
whale, calculated using the correct Level A harassment zone sizes. The 
Final IHA does not authorize Level A harassment take of beluga whale 
(nor was it included in the proposed IHA) despite the change to the 
calculation, given the small size of the Level A harassment zones, the 
low likelihood that a beluga will occur in this area, the lack of 
modeled Level A harassment takes, and the required mitigation, as 
described below.

                             Table 13--Area of Level A and Level B Harassment Zones
----------------------------------------------------------------------------------------------------------------
                                                     Area of level A harassment zone  (km\2\)      Area of level
                                                 ------------------------------------------------  B harassment
                                                   LF cetaceans    MF cetaceans       Phocids      zone  (km\2\)
----------------------------------------------------------------------------------------------------------------
11.5-in H-pile (impact).........................            4.48            0.01            1.28            0.37
14-in H-pile (impact)...........................            3.15            0.00            0.90            1.25

[[Page 10687]]

 
14-in H-pile (vibratory)........................            0.00            0.00            0.00            3.14
48-in pipe pile (impact)........................            7.80            0.01            2.23           14.58
19.69-in sheet pile (vibratory).................            0.00            0.00            0.00           67.68
25-in sheet pile (vibratory)....................            0.00            0.00            0.00           67.68
----------------------------------------------------------------------------------------------------------------


                      Table 14--Estimated Level B Harassment Takes by Species, Pile Size and Type, and Installation/Removal Method
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                       Calculated level B harassment takes
                                             Estimated  ------------------------------------------------------------------------------------------------
                 Activity                     duration                                    Beluga whale b
                                               (days)     Bowhead whale     Gray whale                      Ringed seal    Spotted seal    Bearded seal
--------------------------------------------------------------------------------------------------------------------------------------------------------
DH4
Sheet Pile................................           36            41.65            0.08           20.85          668.04          133.61          113.57
Anchor Pile (11.5-inch H-pile)............            9             0.06               0            0.03            0.90            0.18            0.15
Mooring Dolphins (48-inch Pipe Pile)......           10             2.49               0            1.25           39.98            8.00            6.80
Spud Piles (14-inch H-pile)...............           12             0.64               0            0.32           10.34            2.07            1.76
South Bridge Abutment
Dock Face (Sheet Pile)....................           23            26.61            0.05           13.32          426.80           85.36           72.56
Tailwall (Sheet Pile).....................           23            26.61            0.05           13.32          426.80           85.36           72.56
Anchor Pile (14-inch H-pile)..............            1             0.02               0            0.01            0.34            0.07            0.06
North Bridge Abutment
Dock Face (Sheet Pile)....................           24            27.76            0.05           13.90          445.36           89.07           75.71
Tailwall (Sheet Pile).....................           17            19.67            0.04            9.85          315.46           63.09           53.63
Anchor Pile (14-inch H-pile)..............            1             0.02               0            0.01            0.34            0.07            0.06
Barge Bridge
Mooring Dolphins (48-inch Pipe Piles).....            4             1.00               0            0.50           15.99            3.20            2.72
Spud Piles (14-inch H-piles)..............            4             0.21               0            0.11            3.45            0.69            0.59
                                           -------------------------------------------------------------------------------------------------------------
    Total.................................          164           146.74            0.27           73.46          2353.8          470.76          400.15
Level B Harassment Take Authorized (75% of          123              110           \a\ 2              55           1,765             353             300
 Total)...................................
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ 75 percent of the calculated total is 0.2 takes, however, to account for group size (Clarke et al., 2017), NMFS is authorizing two Level B
  harassment takes of gray whale.
\b\ Includes updated density data from 2019 ASAMM surveys (Clarke et al., 2020).


                      Table 15--Calculated Level A Harassment Takes by Species, Pile Size and Type, and Installation/Removal Method
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                       Calculated level A harassment takes
                                            Estimated  -------------------------------------------------------------------------------------------------
                 Activity                    duration                                     Beluga whale c   Ringed seal c  Spotted seal c  Bearded seal c
                                              (days)     Bowhead whale     Gray whale           d
--------------------------------------------------------------------------------------------------------------------------------------------------------
DH4
Sheet Pile...............................           36                0               0                0               0               0               0
Anchor Pile (11.5-inch H-pile)...........            9             0.69               0                0            3.16            0.63            0.54
Mooring Dolphins (48-inch Pipe Pile).....           10             1.33               0                0            6.11            1.23            1.05
Spud Piles (14-inch H-pile)..............           12                0               0                0               0               0               0
South Bridge Abutment
Dock Face (Sheet Pile)...................           23                0               0                0               0               0               0
Tailwall (Sheet Pile)....................           23                0               0                0               0               0               0
Anchor Pile (14-inch H-pile).............            1             0.05               0                0            0.25            0.05            0.04
North Bridge Abutment
Dock Face (Sheet Pile)...................           24                0               0                0               0               0               0
Tailwall (Sheet Pile)....................           17                0               0                0               0               0               0

[[Page 10688]]

 
Anchor Pile (14-inch H-pile).............            1         \a\ 0.05               0                0          0.2466          0.0495          0.0423
Barge Bridge
Mooring Dolphins (48-inch Pipe Piles)....            4             0.53               0                0            2.44            0.49            0.42
Spud Piles (14-inch H-piles).............            4                0               0                0               0               0               0
                                          --------------------------------------------------------------------------------------------------------------
    Total................................          164             2.65               0                0           12.20            2.45            2.09
Level A Harassment Take Authorized (75%            123            \b\ 0               0                0               9               2               2
 of Total)...............................
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Note that the notice of proposed IHA mistakenly stated 0.5, rather than 0.05. However, the ``Total'' cell was calculated correctly.
\b\ 75 percent of the calculated total is 1.99 takes, however, we do not expect bowheads to occur within the Level A harassment zone, and we do not
  propose to authorize Level A harassment take of bowhead whale.
\c\ In the proposed IHA, Level A harassment takes for beluga whale and phocids were erroneously calculated using the LF cetacean Level A harassment zone
  sizes. The calculations in this table and in the final IHA reflect the corrected estimated Level A harassment take, calculated using the Level A
  harassment zone for belugas and phocids, respectively.
\d\ Beluga whale take estimates were updated to reflect inclusion of the 2019 ASAMM data in the density calculation. (However, the ``Level A harassment
  Take Authorized'' did not change.)

    We do not expect bowhead whales to occur within the Level A 
harassment zones due to the shallow waters (approximately 19 ft in 
depth at the isopleth), lack of historic sightings, and required 
mitigation. As previously noted, waters less than 15 ft (4.5 m) deep 
are considered too shallow to support these whales, and in three 
decades of aerial surveys by BOEM (ASAMM), no bowhead whale has been 
recorded in waters less than 16.4 ft (5 m) deep (Clarke and Ferguson 
2010). Further, no bowhead whales have been observed during ASAMM 
surveys in Block 1a (which encompasses the Level A harassment zone) 
since Block 1a surveys in began in 2016. Additionally, shutdown 
requirements within designated shutdown zones for 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 PTS. Therefore, we do 
not expect Level A harassment of bowhead whales to occur, and are not 
authorizing Level A harassment take of bowheads.
    The likelihood of gray whales occurring in the Level A harassment 
zone is extremely low, as evidenced by the very low densities included 
in the Marine Mammal Occurrence section and the lack of modeled takes 
in Table 15. Further, shutdown requirements within designated shutdown 
zones for LF cetaceans (which include gray whales) are expected to 
prevent take by Level A harassment given the large size and visibility 
of gray whales, and the duration component associated with the Level A 
harassment zones. Even if a gray whale did enter the Level A harassment 
zone, we would not expect it to remain within the zone for a long 
enough period to incur PTS, given the mitigation and visibility. 
Therefore, we do not expect Level A harassment of gray whales to occur, 
and are not authorizing Level A harassment take of gray whale.
    The largest Level A harassment zone for mid-frequency cetaceans 
(including the beluga whale) extends 56 m from the source during impact 
driving of the 48-inch pipe piles (Table 6). Considering the small size 
of the Level A harassment zones, and the low likelihood that a beluga 
will occur in this area, Level A harassment take is unlikely to occur. 
Further, no Level A harassment takes are modeled given the corrected 
zone size used in the calculation in this final IHA. Additionally, AGDC 
is planning to implement a 50 m shutdown zone during this activity, 
which includes the <1 m peak PTS isopleth. We expect shutdown zones 
will eliminate the potential for Level A harassment take of beluga 
whale. Therefore, we are not authorizing takes of beluga whale by Level 
A harassment.

                              Table 16--Authorized Incidental Take by Level A and Level B Harassment, by Species and Stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                              Level A         Level B          Total
                Common name                             Stock               harassment      harassment     instances of        Stock        Percent of
                                                                              take e          take e           take          abundance         stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bowhead Whale.............................  Western Arctic..............               0             110             110          16,820            0.65
Gray Whale................................  Eastern North Pacific.......               0               2               2          26,960           0.007
Beluga Whale \a\..........................  Beaufort Sea................               0              55              55          39,258            0.14
                                            Chukchi Sea.................  ..............  ..............  ..............      \c\ 13,305             0.4
Ringed Seal...............................  Arctic \d\..................           9 \b\           1,765           1,774             N/A             N/A
Spotted Seal..............................  Bering \d\..................           2 \b\             353             355         461,625            0.08

[[Page 10689]]

 
Bearded Seal..............................  Beringia \d\................           2 \b\             300             302             N/A             N/A
--------------------------------------------------------------------------------------------------------------------------------------------------------
 \a\ As noted in the Description of Marine Mammals in the Area of Specified Activities section, beluga whales in the project area are likely to be from
  the Beaufort Sea stock. However, we have conservatively attributed all takes to each stock in our analysis.
 \b\ Updated to reflect the correct Level A harassment zone size for phocids.
 \c\ Updated to reflect the 2020 Draft SAR estimate. The former stock abundance estimate was 20,752.
 \d\ These stock names were updated in the 2020 Draft SARs. The stock names were all formerly ``Alaska.''
 \e\ The estimated number of takes by Level A harassment and Level B harassment does not necessarily equate to the number of individual animals NMFS
  expects will be harassed (which may be lower), but rather to the instances of take (i.e., exposures above the Level A harassment and Level B
  harassment threshold) that are anticipated to occur. These instances may represent either brief exposures (minutes) or, in some cases, longer
  durations of exposure within a day. Some individuals may experience multiple instances of take (i.e., on multiple days) over the course of the year,
  which means that the number of individuals taken is smaller than the total estimated takes. Repeat takes of the same individual are more likely for
  pinnipeds given the likelihood of an individual to remain in the project area for a longer period of time in comparison to a cetacean, and the greater
  anticipated instances of pinniped takes.

Effects of Specified Activities on Subsistence Uses of Marine Mammals

    The availability of the affected marine mammal stocks or species 
for subsistence uses may be impacted by this activity. The subsistence 
uses that may be affected and the potential impacts of the activity on 
those uses are described below. Measures included in this IHA to reduce 
the impacts of the activity on subsistence uses are described in the 
Mitigation Measures section. Last, the information from this section 
and the Mitigation Measures section is analyzed to determine whether 
the necessary findings may be made in the Unmitigable Adverse Impact 
Analysis and Determination section.
    The communities of Nuiqsut, Utqia[gdot]vik and Kaktovik engage in 
subsistence harvests off the North Slope of Alaska. Alaska Native 
communities have harvested bowhead whales for subsistence and cultural 
purposes with oversight and quotas regulated by the International 
Whaling Commission (IWC). The NSB Department of Wildlife Management has 
been conducting bowhead whale subsistence harvest research since the 
early 1980's to collect the data needed by the IWC to set harvest 
quotas. Bowhead whale harvest (percent of total marine mammal harvest), 
harvest weight, and percent of households using bowhead whale are 
presented in Table 25 of AGDC's application.
    Most of the Beaufort Sea population of beluga whales migrate from 
the Bering Sea into the Beaufort Sea in April or May. The spring 
migration routes through ice leads are similar to those of the bowhead 
whale. Fall migration through the western Beaufort Sea occurs in 
September or October. Surveys of the fall distribution strongly 
indicate that most belugas migrate offshore along the pack ice front 
beyond the reach of subsistence harvesters. Beluga whales are harvested 
opportunistically during the bowhead harvest and throughout ice-free 
months. No beluga whale harvests were reported in 2006 survey 
interviews conducted by Stephen R. Braund & Associates (SRBA) in any 
community (SRBA 2010). Beluga harvests were also not reported in 
Nuiqsut and Kaktovik, although households did report using beluga 
whale, likely through sharing from other communities (Brown et al., 
2016). We do not expect the planned activities at the AK LNG project 
site to affect beluga whale subsistence harvests, as none are expected.
    Gray whale harvests were not reported by any of the communities 
surveyed by Alaska Department of Fish and Game (ADF&G) in any of the 
survey years, and therefore are not included as an important 
subsistence species and are not further discussed.
    The community of Utqia[gdot]vik's subsistence activities occur 
outside of the area impacted by activities considered in this 
authorization. As described below, we do not expect impacts to 
Utqia[gdot]vik's subsistence activities, and therefore they are not 
discussed further beyond the explanation provided here.
    Impacts to marine mammals from the planned construction would 
mostly include limited, temporary behavioral disturbances of seals, 
however, some slight PTS within the lower frequencies associated with 
pile driving is possible. Additionally, a small number of takes of 
bowhead whales, by Level B harassment only, are predicted to occur in 
the vicinity of AGDC's activity. Even if some subset of taken 
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 Utqia[gdot]vik 
hunting area, and therefore, significant impacts to the Utqia[gdot]vik 
hunt would be unlikely. Please refer to AGDC's application for 
additional information.
    The planned activities and associated harassment of marine mammals 
are not expected to impact marine mammals in numbers or locations 
sufficient to render them unavailable for Utqia[gdot]vik subsistence 
harvest given the short-term, temporary, and localized nature of 
construction activities, and the planned mitigation measures. 
Additionally, no serious injury or mortality of marine mammals is 
expected or authorized, and the activities are not expected to have any 
impacts on reproductive or survival rates of any marine mammal species. 
Altogether, the authorized take by harassment will not have an 
unmitigable adverse impact on the availability of any species or stock 
for subsistence uses.
Kaktovik
    Kaktovik is the easternmost village in the NSB. Kaktovik is located 
on the north shore of Barter Island, situated between the Okpilak and 
Jago rivers on the Beaufort Sea coast. Kaktovik's subsistence-harvest 
areas are to the east of the project area and target marine mammal 
species migrating eastward during spring and summer occur seaward of 
the project area and westward in the fall.
    Kaktovik bowhead whale hunters reported traveling between Camden 
Bay to the west and Nuvagapak Lagoon to the east (SRBA 2010). This 
range does not include the project area impacted by the activities 
analyzed for this IHA. The small number of takes of bowhead whales, by 
Level B harassment only, predicted to occur in the vicinity of AGDC's 
activity are not expected to have any impacts on the fitness of any 
bowhead whales. Further, we do not expect construction activities to 
deflect the bowhead whale migration offshore in the Kaktovik hunting 
area, given the distance from the western extent of the

[[Page 10690]]

hunting area (Camden Bay) to the predicted Level B harassment 
isopleths. Even if some subset of taken 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 Kaktovik hunting area during the eastbound 
migration, and during the westbound migration, a bowhead exposed to 
construction noise would have already passed the hunting area prior to 
exposure. Significant impacts to the Kaktovik hunt would be unlikely, 
and Kaktovik bowhead whale hunting is not discussed further. Please 
refer to AGDC's application for additional information.
    Ringed, spotted and bearded seals are harvested by the community of 
Kaktovik. Residents hunt seals in rivers during ice-free months, 
primarily July-August. Ringed seals are an important subsistence 
resource for Native Alaskans living in communities along the Beaufort 
Sea coast. Kaktovik hunters travel by boat to look for ringed seals on 
floating ice (often while also hunting for bearded seal) or sometimes 
along the ice edge by snow machine before break-up, during the spring 
(SRBA 2010). In 2006, 7 people (18 percent of survey respondents) 
indicated that they had recently hunted for ringed seals in Kaktovik 
(SRBA 2010). Residents reported looking for ringed seal, usually while 
also searching for bearded seal, offshore between Prudhoe Bay to the 
west and Demarcation Bay to the east (SRBA 2010). Ringed seal hunting 
typically peaks between March and August but continues into September, 
as well (SRBA 2010). Although residents reported hunting ringed seals 
up to approximately 30 mi (48 km) from shore, the highest numbers of 
overlapping use areas generally occur within a few miles from shore 
(SRBA 2010). The total use area for ringed seal from 1995-2006 
encompassed approximately 2,139 mi\2\ (5540 km\2\). Harvest of ringed 
seals by Kaktovik hunters does not typically occur to the west of 
Camden Bay. Additionally, impacts to ringed seals are expected to 
include temporary behavioral disturbances and some slight PTS within 
the lower frequencies associated with pile driving. Serious injury or 
mortality of ringed seals is not anticipated from the planned 
activities, and the activities are not expected to have any impacts on 
ringed seal reproductive or survival rates, or to impact availability 
of ringed seals. Therefore, AK LNG project activities are not expected 
to impact Kaktovik ringed seal harvests.
    Kaktovik hunters harvested 126 pounds of spotted seals in 1992 
(ADF&G CSIS; retrieved and analyzed August 15, 2018). Spotted seals 
were not reported harvested in 2006 survey interviews conducted in 
Nuiqsut (SRBA 2010).
    Kaktovik bearded seal hunting occurs along the coast as far west as 
Prudhoe Bay and as far east as the United States/Canada border (SRBA 
2010). Residents reported looking for bearded seal as far as 
approximately 30 mi (48 km) from shore, but generally hunt them closer 
to shore, up to 5 mi (8 km; SRBA 2010). Between 1994 -2003, 29 bearded 
seals were taken in Kaktovik. In 2006, 7 people (18 percent of survey 
respondents) indicated that they had recently hunted for bearded seals 
in Kaktovik (SRBA 2010). Bearded seal hunting activities, like ringed 
seal, begin in March, peaking in July and August, and then conclude in 
September (SRBA 2010).
    The community of Kaktovik is approximately 100 (direct) mi (160 km) 
from the planned project at Prudhoe Bay; subsistence activities for 
these communities primarily occur outside of the project construction 
area and the associated Level A and Level B harassment zones. The 
planned construction and use of improvements to West Dock would occur 
in Prudhoe Bay, adjacent to existing oil and gas infrastructures, and 
in an area that is not typically used for subsistence other than 
extremely limited bearded seal hunting by residents of Kaktovik.
    Because of the distance from Kaktovik and Kaktovik's very limited 
use of waters offshore of Prudhoe Bay, and because the planned 
activities would occur in an already-developed area, it is unlikely 
that the planned activities would have any effects on the use of marine 
mammals for subsistence by residents of Kaktovik. Further, the planned 
activities are not expected to impact marine mammals in numbers or 
locations sufficient to render them unavailable for subsistence harvest 
given the short-term, temporary, and localized nature of construction 
activities, and the planned mitigation measures. Impacts to marine 
mammals would mostly include limited, temporary behavioral disturbances 
of seals, with some potential slight PTS within the lower frequencies 
associated with pile driving. Serious injury or mortality of marine 
mammals is not anticipated from the planned activities, and the 
activities are not expected to have any impacts on reproductive or 
survival rates of any marine mammal species. Therefore, we do not 
discuss Kaktovik's subsistence activities further.
Nuiqsut
    The planned construction activities would occur closest to the 
marine subsistence use area used by the Native Village of Nuiqsut. 
Nuiqsut is located on the west bank of the Nechelik Channel on the 
lower Colville River, about 25 mi (40 km) from the Arctic Ocean and 
approximately 150 mi (242 km) southeast of Utqia[gdot]vik. Nuiqsut 
subsistence hunters utilize an extensive search area, spanning 16,322 
mi\2\ (km\2\) across the central Arctic Slope (see Figure 19 of AGDC's 
application, Brown et al., 2016). Marine mammal hunting is primarily 
concentrated in two areas: 1) Harrison Bay, between Atigaru Point and 
Oliktok Point, including a northward extent of approximately 50 mi (80 
km) beyond the Colville River Delta (Brown et al., 2016); and 2) east 
of the Colville River Delta between Prudhoe and Foggy Island bays, 
which includes an area of approximately 100 square mi surrounding the 
Midway Islands, McClure Island and Cross Island (Brown et al., 2016). 
The community of Nuiqsut uses subsistence harvest areas adjacent to the 
planned construction area; however, West Dock is not a common hunting 
area, nor is it visited regularly by Nuiqsut subsistence hunters 
primarily because of its industrial history.
    The community of Nuiqsut also harvests ringed, spotted and bearded 
seals. Seal hunting typically begins in April and May with the onset of 
warmer temperatures. Many residents continue to hunt seals after spring 
breakup as well (Brown et al., 2016).
    The most important seal hunting area for Nuiqsut hunters is off the 
Colville Delta, an area extending as far west as Fish Creek and as far 
east as Pingok Island. Seal hunting search areas by Nuiqsut hunters 
also included Harrison Bay, and a 30-mi (48-km) stretch northeast of 
Nuiqsut between the Colville and Kuparuk rivers, near Simpson Lagoon 
and Jones Islands (Brown et al., 2016). Cross Island is a productive 
area for seals, but is too far from Nuiqsut to be used on a regular 
basis. Seal subsistence use areas of Nuiqsut from 1995 through 2006 are 
depicted in Figure 21 of AGDC's application.
    Ringed seals are an important subsistence resource for Native 
Alaskans living in communities along the Beaufort Sea coast. Nuiqsut 
residents commonly harvest ringed seal in the Beaufort Sea during the 
summer months (SRBA 2010). There are a higher number of use areas 
extending east and

[[Page 10691]]

west of the Colville River delta. Residents reported traveling as far 
as Cape Halkett to the west and Camden Bay to the east in search of 
ringed seal. Survey respondents reported traveling offshore up to 30 mi 
(48 km; SRBA 2010). Residents reported hunting ringed seals throughout 
the late spring, summer, and early fall with a higher number of use 
areas reported in June, July, and August (SRBA 2010). In 2006, 12 
people (36 percent of survey respondents) indicated that they had 
recently hunted for ringed seals in Nuiqsut (SRBA 2010).
    Nuiqsut bearded seal use areas extend as far west as Cape Halkett, 
as far east as Camden Bay, and offshore up to 40 mi (64 km). In 2006, 
12 people (69 percent of survey respondents) indicated that they had 
recently hunted for bearded seals in Nuiqsut (SRBA 2010). Nuiqsut 
hunters reported hunting bearded seal during the summer season in open 
water as the seals are following the ice pack. Residents reported 
hunting bearded seal between June and September, although a small 
number of use areas were reportedly used in May and October (SRBA 
2010). The number of reported bearded seal use areas peak in July and 
August, when the majority of seals are available along the ice pack 
(SRBA 2010).
    Nuiqsut's bowhead whale hunt occurs in the fall at Cross Island, a 
barrier island located approximately 12 mi (19 km) northwest of West 
Dock. Nuiqsut whalers base their activities from Cross Island 
(Galginaitis 2014), and the whaling search and the harvest areas 
typically are concentrated north of the island. Hunting activities 
between 1997 and 2006 occurred almost as far west as Thetis Island, as 
far east as Barter Island (Kaktovik), and up to approximately 50 mi (80 
km) offshore (SRBA 2010). Harvest locations in 1973-2011 and GPS tracks 
of 2001-2011 whaling efforts are shown in Figure 19 of AGDC's 
application.
    Bowhead whales are harvested by Nuiqsut whalers during the fall 
whaling season. Nuiqsut residents typically hunt bowhead whales in 
September, although a small number of use areas were reported in August 
and extending into October (SRBA 2010). Pile driving will not occur 
during Nuiqsut whaling, as stated in the Mitigation Measures section.
    Nuiqsut subsistence hunting crews operating from Cross Island have 
harvested three to four bowhead whales per year (Bacon et al., 2009; 
Galginaitis 2014). In 2014, the AEWC allocated Nuiqsut a quota of four 
bowhead whales each year; however, through transfers of quota from 
other communities, in 2015 Nuiqsut was able to harvest five whales 
(Brown et al., 2016). In 2006, 10 people (30 percent of survey 
respondents) in Nuiqsut indicated that they had recently hunted for 
bowhead whales (SRBA 2010). In 2016, Nuiqsut whaling crews harvested 
four bowhead whales (Suydam et al., 2017).
    Nuiqsut is 70 mi (112 km) away from the planned project, and is 
likely to be the community that has the greatest potential to 
experience any impacts to subsistence practices. AGDC asserts that the 
primary potential for AK LNG project impacts to Nuiqsut's subsistence 
use of marine mammals is associated with barge activity, which it 
states could interfere with summer seal and fall bowhead whale hunting 
(Alaska LNG 2016). As described previously, barging activity is 
unlikely to incidentally take marine mammals; however, the noise or 
presence of barges could affect the behavior of whales in a manner that 
makes successful harvests more difficult. Although barge activities 
would not cease during Nuiqsut's fall bowhead whale hunting activities, 
the final IHA requires vessels to transit landward of Cross Island 
during the entirety of the Nuiqsut whaling season (approximately August 
25-September 15, though the exact dates may change).
    Pile driving associated with construction at West Dock could affect 
subsistence hunting of bowhead whales, as the Level B harassment zones 
extend up to 4.6 km from the pile driving site for some pile and hammer 
type combinations. As such, AGDC will not pile drive during the Nuiqsut 
whaling season (see Mitigation Measures). AGDC has consulted with AEWC 
and NSB on mitigation measures to limit impacts (Alaska LNG 2016), and 
has continued to provide formal and informal project updates to these 
groups, and is committed to continuing coordination as described in 
AGDC's POC.
    The planned activities are not expected to impact marine mammals in 
numbers or locations sufficient to render them unavailable for 
subsistence harvest given the short-term, temporary, and localized 
nature of construction activities, and the planned mitigation measures. 
Impacts to marine mammals would mostly include limited, temporary 
behavioral disturbances of seals, however, some slight PTS within the 
lower frequencies associated with pile driving is possible. Serious 
injury or mortality of marine mammals is not anticipated from the 
planned activities, and the activities are not expected to have any 
impacts on reproductive or survival rates of any marine mammal species.
    In summary, impacts to subsistence hunting are not expected due to 
the distance between West Dock construction and primary seal hunting 
areas, the limited extent of impacts to marine mammals (Level B 
harassment, and slight Level A harassment for a small number of seals) 
and planned mitigation during the Nuiqsut bowhead whale hunt.

Mitigation Measures

    In order to issue an IHA under Section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses. NMFS regulations require applicants for incidental 
take authorizations to include information about the availability and 
feasibility (economic and technological) of equipment, methods, and 
manner of conducting the activity or other means of effecting the least 
practicable adverse impact upon the affected species or stocks and 
their habitat (50 CFR 216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat, as 
well as subsistence uses. This considers the nature of the potential 
adverse impact being mitigated (likelihood, scope, range). It further 
considers the likelihood that the measure will be effective if 
implemented (probability of accomplishing the mitigating result if 
implemented as planned), the likelihood of effective implementation 
(probability implemented as planned), and;
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.

[[Page 10692]]

Mitigation for Marine Mammals and Their Habitat

    In addition to the measures described later in this section, AGDC 
will employ the following mitigation measures:
    <bullet> Conduct briefings between construction supervisors and 
crews and the marine mammal monitoring team prior to the start of all 
pile driving activity and when new personnel join the work, to explain 
responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures;
    <bullet> For in-water construction, heavy machinery activities 
other than pile driving, if a marine mammal comes within 10 m (33 ft), 
operations shall cease and vessels shall reduce speed to the minimum 
level required to maintain steerage and safe working conditions;
    <bullet> For those marine mammals for which Level B harassment take 
has not been requested, in-water pile installation/removal will shut 
down immediately when it is safe to do so if such species are observed 
within or entering the Level B harassment zone; and
    <bullet> If take reaches the authorized limit for an authorized 
species, pile installation will be stopped as these species approach 
the Level B harassment zone to avoid additional take.

                          Table 17--Shutdown Zones During Pile Installation and Removal
----------------------------------------------------------------------------------------------------------------
                                                                                Shutdown Zone  (m)
              Activity                        Hammer Type        -----------------------------------------------
                                                                   LF cetaceans    MF cetaceans       Phocids
----------------------------------------------------------------------------------------------------------------
11.5-inch H-Pile....................  Impact....................           1,200              50             500
14-inch H-Pile......................  Impact....................           1,200              50             500
                                      Vibratory.................              10              10              10
48-inch Pipe Pile...................  Impact....................           1,600              50             500
Sheet Piles.........................  Vibratory.................              20              10              10
Screeding...........................  ..........................             215  ..............  ..............
----------------------------------------------------------------------------------------------------------------

    Aircraft must transit at an altitude of 457 m (1,500 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. If flights must occur at altitudes less 
than 457 m (1,500 ft) due to environmental conditions, aircraft must 
make course adjustments, as needed, to maintain at least a 457 m (1,500 
ft) separation from all observed marine mammals. Helicopters (if used) 
must not hover or circle above marine mammals. A minimum transit 
altitude is expected to reduce the potential for disturbance to marine 
mammals from transiting aircraft.
    AGDC is required to implement all mitigation measures described in 
the biological opinion (issued on June 3, 2020).
    The following mitigation measures would apply to AGDC's in-water 
construction activities.
    Establishment of Shutdown Zones--AGDC will establish shutdown zones 
for all pile driving and removal activities. The purpose of a shutdown 
zone is generally to define an area within which shutdown of the 
activity would occur upon sighting of a marine mammal (or in 
anticipation of an animal entering the defined area). Shutdown zones 
will vary based on the activity type and marine mammal hearing group 
(see Table 17). The largest shutdown zones are generally for low 
frequency cetaceans as shown in Table 17. In this instance, the largest 
shutdown zone for low frequency cetaceans is 1,600 m. AGDC expects that 
they 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.
    The placement of PSOs during all pile driving and removal 
activities (described in detail in the Monitoring and Reporting 
section) will ensure that the entire shutdown zone is visible during 
pile installation. If visibility degrades to where the PSO determines 
that they cannot effectively monitor the entire shutdown zone during 
pile driving, the applicant may continue to drive the pile section that 
was being driven to its target depth when visibility degraded to 
unobservable conditions, but will not drive additional sections of 
pile. Pile driving may continue during low light conditions to allow 
for the evaluation of NVDs and IR sensing devices.
    Monitoring for Level A and Level B Harassment--AGDC will monitor 
the Level B harassment zones (areas where SPLs are equal to or exceed 
the 160 dB rms threshold for impact driving and the 120 dB rms 
threshold during vibratory driving) and Level A harassment zones, to 
the extent practicable. Monitoring the Level A and Level B harassment 
zones enables observers to be aware of and communicate the presence of 
marine mammals in the project area outside the shutdown zone and thus 
prepare for a potential shutdown of activity should the animal enter 
the shutdown zone. Placement of PSOs on elevated structures on West 
Dock will allow PSOs to observe phocids within the Level A and Level B 
harassment zones, to an estimated distance of 500 m. However, due to 
the large Level A and Level B harassment zones (Table 6), PSOs will not 
be able to effectively observe the entire zones during all activities 
for all species. Therefore, marine mammal exposures within the visible 
portion of the harassment zones will be recorded, and potential 
exposures within the entire harassment zones will be estimated based 
upon the number of observed exposures and the percentage of the Level A 
or Level B harassment zone that was not visible. AGDC will also conduct 
acoustic monitoring as described in the Monitoring and Reporting 
section, below.
    Pre-activity Monitoring--Prior to the start of daily in-water 
construction activity, or whenever a break in pile driving or removal 
of 30 minutes or longer occurs, PSOs will observe the shutdown zone and 
the visible portions of the Level A and Level B harassment zones for a 
period of 30 minutes. If a marine mammal is observed within the 
shutdown zone, a soft-start cannot proceed until the animal has left 
the zone or has not been observed for 15 minutes (pinnipeds) or 30 
minutes (cetaceans). When a marine mammal for which Level B harassment 
take is authorized is present in the Level B harassment zone, 
activities may begin and Level B harassment take will be recorded. If 
the entire Level B harassment zone is not visible at the start of 
construction pile driving or removal activities can begin. If work 
ceases for more than 30 minutes, the pre-activity monitoring of both 
the Level

[[Page 10693]]

B harassment zone and shutdown zones will commence.
    Nighttime Monitoring--PSOs will use NVDs and IR for nighttime and 
low visibility monitoring. AGDC will select devices for monitoring, and 
will test the devices to determine the efficacy of the monitoring 
equipment and technique. For a detailed explanation of AGDC's plan to 
test the NVDs and IR equipment, please see AGDC's 4MP, available online 
at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable. 
(Please note that AGDC will not assess object detection at distance 
intervals using buoys as stated in the 4MP. Rather, they will test 
object detection on land using existing landmarks at known distances 
from PSOs, such as road signs.)
    Soft Start--Soft-start procedures are believed to provide 
additional protection to marine mammals by providing warning and/or 
giving marine mammals a chance to leave the area prior to the hammer 
operating at full capacity. For impact pile driving, contractors will 
be required to provide an initial set of three strikes from the hammer 
at reduced energy, followed by a 30-second waiting period. This 
procedure will be conducted three times before impact pile driving 
begins. Soft start will be implemented at the start of each day's 
impact pile driving and at any time following cessation of impact pile 
driving for a period of thirty minutes or longer.
    Pile Driving During Contingency Period--In the event that AGDC must 
continue pile driving or removal during their contingency period 
(February- April 2024), AGDC must begin pile driving before March 1, 
the known onset of ice seal lairing season. Initiating pile driving 
before March 1 is expected to discourage seals from establishing 
birthing lairs near pile driving. Discouraging seals from establishing 
birthing lairs near pile driving will likely reduce potential instances 
of take by Level B harassment by reducing the likelihood of an 
individual seal occurring within the Level B harassment zone on 
multiple occasions, which would be far more likely if seals established 
lairs within the zone. Additionally, a subsistence advisor would survey 
areas within a buffer zone of DH4 where water depth is greater than 10 
ft (3 m) to identify potential ringed seal structures before activity 
begins. Construction crews must avoid identified ice seal structures by 
a minimum of 500 ft. (150 m). NMFS expects these measures to prevent 
physical interaction between seals and construction equipment.
    AGDC does not plan to use a bubble curtain or other sound 
attenuation device, and NMFS concurs that sound attenuation is not 
appropriate for this project for the reasons described in NMFS' 
response to Comment 5 in the Comments and Responses section.

Mitigation for Subsistence Uses of Marine Mammals or Plan of 
Cooperation

    Regulations at 50 CFR 216.104(a)(12) further 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 the following:
    <bullet> A statement that the applicant has notified and provided 
the affected subsistence community with a draft POC;
    <bullet> 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;
    <bullet> 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
    <bullet> 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.
    AGDC provided a draft POC to NMFS on March 27, 2019 and submitted 
revised versions on February 7, 2020, November 16, 2020, December 21, 
2020, and most recently, January 4, 2021. The POC outlines AGDC's 
extensive coordination with subsistence communities that may be 
affected by the AK LNG project. It includes a brief description of the 
project, community outreach that has already been conducted, as well as 
the concerns raised in those discussions and how they were addressed, 
and project mitigation measures. AGDC will continue coordination with 
subsistence communities throughout the project duration, and will 
develop a Communications Plan in coordination with subsistence groups, 
as described below and in the POC. The POC is a living document and has 
been updated throughout the project review and permitting process. The 
final IHA includes a requirement stating that AGDC must conduct the 
communication and coordination as described in the POC, which is 
available on our website at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.
    AGDC continues to document its communications with the North Slope 
subsistence communities, as well as the substance of its communications 
with subsistence stakeholder groups, and has developed mitigation 
measures that include measures suggested by community members as well 
as industry standard measures. AGDC will continue to routinely engage 
with local communities and subsistence groups. Multiple user groups are 
often consulted simultaneously as part of larger coalition meetings 
such as the Arctic Safety Waterways Committee meetings. Local 
communities and subsistence groups identified by AGDC are listed in the 
POC. AGDC will develop a Communication Plan and will implement this 
plan before initiating construction operations to coordinate activities 
with local subsistence users, as well as Village Whaling Captains' 
Associations, to minimize the risk of interfering with subsistence 
hunting activities, and keep current as to the timing and status of the 
bowhead whale hunt and other subsistence hunts. A project informational 
mailer with a request for community feedback (traditional mail, email, 
phone) will be sent to community members prior to construction. 
Following the construction season, AGDC intends to have a post-season 
co-management meeting with the commissioners and committee heads to 
discuss results of mitigation measures and outcomes of the preceding 
season. The goal of the post-season meeting is to build upon the 
knowledge base, discuss successful or unsuccessful outcomes of 
mitigation measures, and possibly refine plans or mitigation measures 
if necessary.
    The AEWC works annually with industry partners to develop a CAA. 
This agreement implements mitigation measures that allow industry to 
conduct their work in or transiting the vicinity of active subsistence 
hunters, in areas where subsistence hunters anticipate hunting, or in 
areas that are in sufficient proximity to areas expected to be used for 
subsistence hunting where the planned activities could potentially 
adversely affect the subsistence bowhead whale hunt through effects on 
bowhead whales, while maintaining the availability of bowheads for 
subsistence hunters. AGDC is required to enter the

[[Page 10694]]

CAA for the construction year by an order from the FERC.
    AGDC will not conduct pile driving during the Nuiqsut whaling 
season in an effort to eliminate effects on the availability of bowhead 
whales for subsistence hunting that could occur as a result of project 
noise. Nuiqsut whaling is approximately August 25-September 15, though 
the exact dates may change.
    Barging activities could potentially impact Nuiqsut's fall bowhead 
whale hunt and possibly other marine mammal harvest activities in the 
Beaufort Sea. As mentioned previously, barging activities are beyond 
the scope of this IHA, and no take is expected to occur as a result of 
barging activities. However, the final IHA requires AGDC to limit 
barges to waters landward of Cross Island during the Nuiqsut whaling 
season (approximately August 25-September 15, though the exact dates 
may change) in an effort to avoid any potential impacts on subsistence 
uses. AGDC has consulted with AEWC and NSB on mitigation measures to 
limit impacts (Alaska LNG 2016), and has continued to provide formal 
and informal project updates to these groups, as recently as October 
2020. As described above in the Effects of Specified Activities on 
Subsistence Uses of Marine Mammals section, AGDC's construction 
activities at West Dock do not overlap with the areas where subsistence 
hunters typically harvest ice seals, and given the extent of impacts to 
seals described in that section, these activities are not expected to 
impact subsistence hunts of ice seals. Therefore, the final IHA does 
not include mitigation measures for subsistence harvest of ice seals; 
however, AGDC will continue to meet with subsistence groups, including 
the Ice Seal Committee, as described in the POC.
    Based on our evaluation of the applicant's planned measures, as 
well as other measures considered by NMFS, NMFS has determined that the 
planned mitigation measures provide the means effecting the least 
practicable impact on the affected species or stocks and their habitat, 
paying particular attention to rookeries, mating grounds, and areas of 
similar significance, and on the availability of such species or stock 
for subsistence uses.

Monitoring and Reporting

    In order to issue an IHA for an activity, Section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
planned action area. Effective reporting is critical both to compliance 
as well as ensuring that the most value is obtained from the required 
monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
    <bullet> Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
    <bullet> Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
    <bullet> Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
    <bullet> How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
    <bullet> Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
    <bullet> Mitigation and monitoring effectiveness.

Visual Monitoring

    Marine mammal monitoring must be conducted in accordance with the 
Marine Mammal Monitoring Plan, available online at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable. Marine mammal 
monitoring during pile driving and removal must be conducted by NMFS-
approved PSOs in a manner consistent with the following:
    <bullet> Independent PSOs (i.e., not construction personnel) who 
have no other assigned tasks during monitoring periods must be used;
    <bullet> At least one PSO must have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization.
    <bullet> Where a team of three or more PSOs are required, a lead 
observer or monitoring coordinator must be designated. The lead 
observer must have prior experience working as a marine mammal observer 
during construction;
    <bullet> Other PSOs may substitute education (degree in biological 
science or related field) or training for experience.
    <bullet> PSOs may also substitute Alaska native traditional 
knowledge for experience. (NMFS recognizes that PSOs with traditional 
knowledge may also have prior experience, and therefore be eligible to 
serve as the lead PSO.); and
    <bullet> AGDC must submit PSO curriculum vitae for approval by NMFS 
prior to the onset of pile driving.
    PSOs should have the following additional qualifications:
    <bullet> Ability to conduct field observations and collect data 
according to assigned protocols;
    <bullet> Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
    <bullet> Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    <bullet> Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and
    <bullet> Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    At least two PSOs will be present during all pile driving/removal 
activities. PSOs will have an unobstructed view of all water within the 
shutdown zone. PSOs will observe as much of the Level A and Level B 
harassment zone as possible. PSO locations are as follows:
    i. Dock Head 4--During impact pile driving at DH4, two PSOs must be 
stationed to view toward the east, north, and west of the seawater 
treatment plant. During vibratory pile driving at

[[Page 10695]]

DH4, two PSOs must monitor from each PSO location (four PSOs); and
    ii. Barge Bridge--During work at the barge bridge, two PSOs must be 
stationed at the north end of the bridge.
    PSOs will be stationed on elevated platforms at DH4, and on the 
elevated bridge during work at the barge bridge. They will possess the 
equipment described in the 4MP, including NVDs during nighttime 
monitoring. However, during the primary construction season, nighttime 
on the North Slope will be brief. Given the elevated PSO sites and 
equipment, AGDC expects that they will be able to effectively observe 
phocids at distances up to 500 m, large cetaceans at 2-4km, and belugas 
at 2-3km, however, PSOs will not be able to effectively observe the 
entire area of the Level A (seals only) or Level B harassment zones 
during all pile driving activities.
    PSOs will begin monitoring three days prior to the onset of pile 
driving and removal activities and continue through three days after 
completion of the pile driving and removal activities. PSOs will 
monitor 24 hours per day, even during periods when construction is not 
occurring. In addition, observers shall record all incidents of marine 
mammal occurrence, regardless of distance from activity, and shall 
document any behavioral reactions in concert with distance from piles 
being driven or removed. Pile driving activities include the time to 
install or remove a single pile or series of piles, as long as the time 
elapsed between uses of the pile driving equipment is no more than 30 
minutes.

Acoustic Monitoring

    Acoustic monitoring, to be conducted for purposes of measuring 
sound source levels and sound propagation, must be conducted in 
accordance with accepted methodology as described in an Acoustic 
Monitoring Plan, which AGDC must develop after its contractor is 
selected. The plan must be reviewed by NMFS, the NSB, and the AEWC, and 
approved by NMFS. AGDC must conduct acoustic monitoring for the number 
of each pile type and size indicated in the approved plan. NMFS may 
adjust the shutdown zones and revise the Level A and Level B harassment 
zones, as appropriate, pending review and approval of the results of 
acoustic monitoring.
    AGDC will also conduct PAM for marine mammals. AGDC will deploy 
three hydrophones during the open-water season to monitor for marine 
mammals, in accordance with the Marine Mammal Monitoring and Mitigation 
Plan, dated December 21, 2020 and the Acoustic Monitoring Plan 
referenced above. This PAM is intended to inform the estimate of marine 
mammals in the Level B harassment zone, given that PSOs are not able to 
observe the entire zone for all species and activities.
    AGDC will deploy the hydrophones in the locations recommended by 
the PRP, as shown in Figure 4 of its Marine Mammal Monitoring and 
Mitigation Plan (dated December 21, 2020), and will adjust the 
locations as appropriate if the Level B harassment zones are adjusted 
following SSV results. AGDC will deploy the PAM recorders three days 
prior to the start of pile driving, and will retrieve them three days 
after completion of pile driving during the open-water season.
    Should construction be required during the contingency period when 
there will be ice-cover, AGDC will deploy one hydrophone at the end of 
the open-water season, located in between the 2,200 m and 4,700 m 
zones, perpendicular to the pile driving site. The location must be 
reviewed by NMFS, the NSB, and the AEWC, and approved by NMFS prior to 
deployment. Additional hydrophones during the contingency period are 
not warranted, as, 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).

Reporting

    A draft marine mammal monitoring report will be submitted to NMFS 
within 90 days after the completion of marine mammal and acoustic 
monitoring or 60 days prior to the issuance of any subsequent IHA for 
this project, whichever comes first. The report will include an overall 
description of work completed, a narrative regarding marine mammal 
sightings, and associated PSO data sheets. Specifically, the report 
must include:
    <bullet> Dates and times (begin and end) of all marine mammal 
monitoring;
    <bullet> Construction activities occurring during each daily 
observation period, including precise start and stop time of each type 
of construction operation mode, how many and what type of piles were 
driven or removed and by what method (i.e., impact or vibratory);
    <bullet> Total number of hours during which each construction 
activity type occurred;
    <bullet> Total number of hours that PSOs were on duty during each 
construction activity, and total number of hours that PSOs were on duty 
during periods of no construction activity;
    <bullet> Weather parameters and water conditions during each 
monitoring period (e.g., wind speed, percent cover, visibility, sea 
state), and number of hours of observation that occurred during various 
visibility and sea state conditions;
    <bullet> The number of marine mammals observed, by species and 
operation mode, relative to the pile location, and if pile driving or 
removal was occurring at time of sighting;
    <bullet> The number of marine mammals observed (including periods 
with no construction);
    <bullet> Age and sex class, if possible, of all marine mammals 
observed;
    <bullet> PSO locations during marine mammal monitoring, including 
elevation above sea level;
    <bullet> Distances and bearings of each marine mammal observed to 
the pile being driven or removed for each sighting (if pile driving or 
removal was occurring at time of sighting);
    <bullet> Description of any marine mammal behavior patterns during 
observation, including direction of travel and estimated time spent 
within the Level A and Level B harassment zones while the source was 
active;
    <bullet> Number of individuals of each species (differentiated by 
month as appropriate) detected within the Level A and Level B 
harassment zones;
    <bullet> Histograms of perpendicular distances to PSO sightings, by 
species (or species group if sample sizes are small);
    <bullet> Sighting rates summarized into daily or weekly periods for 
the before, during, and after construction periods;
    <bullet> Maps showing visual detections by species and construction 
activity type.
    <bullet> Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensued, and resulting behavior of the animal, if 
any;
    <bullet> Description of attempts to distinguish between the number 
of individual animals taken and the number of incidences of take, such 
as ability to track groups or individuals;
    <bullet> An estimation of potential takes, by species, by Level A 
and Level B harassment based on the number of observed exposures within 
the Level A and Level B harassment zones and the percentages of the 
Level A and Level B harassment zones that were not visible; and

[[Page 10696]]

    <bullet> Submit all PSO datasheets and/or raw sighting data (in a 
separate file from the Final Report referenced immediately above).
    If no comments are received from NMFS within 30 days, the draft 
report will constitute the final report. If comments are received, a 
final report addressing NMFS comments must be submitted within 30 days 
after receipt of comments.
    For the SSV, AGDC's acoustic monitoring report must, at minimum, 
include the following:
    <bullet> Hydrophone equipment and methods: Recording device, 
sampling rate, distance (m) from the pile where recordings were made; 
depth of recording device(s).
    <bullet> Type and size of pile being driven, substrate type, method 
of driving during recordings.
    <bullet> For impact pile driving: Pulse duration and mean, median, 
and maximum sound levels (dB re: 1[mu]Pa): Cumulative sound exposure 
level (SELcum), peak sound pressure level (SPLpeak), root-mean-square 
sound pressure level (SPL<INF>rms</INF>), and single-strike sound 
exposure level (SELs-s).
    <bullet> For vibratory driving/removal: Mean, median, and maximum 
sound levels (dB re: 1[mu]Pa): SPL<INF>rms</INF>, SELcum, and timeframe 
over which the sound is averaged.
    <bullet> Number of strikes (impact) or duration (vibratory) per 
pile measured, one-third octave band spectrum, power spectral density 
plot.
    <bullet> Estimated source levels referenced to 10 m, transmission 
loss coefficients, and estimated Level A and Level B harassment zones.
    For the PAM for marine mammals, AGDC's acoustic monitoring report 
must, at minimum, include the following:
    <bullet> Number of marine mammal detections (including species, 
date and time of detections, and type of pile driving underway during 
each detection, if applicable).
    <bullet> Detection rates summarized into daily or weekly periods 
for the before, during, and after construction periods.
    <bullet> Received sound levels from pile driving activity.
    <bullet> The following hydrophone equipment and method information: 
Recording devices, sampling rate, sensitivity of the PAM equipment, 
locations of the hydrophones, duty cycle, distance (m) from the pile 
where recordings were made, depth of recording devices, depth of water 
in area of recording devices.
    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the IHA-holder shall report 
the incident to the Office of Protected Resources (OPR) (301-427-8401), 
NMFS and to the Alaska regional stranding coordinator (907-586-7209) as 
soon as feasible. If the death or injury was clearly caused by the 
specified activity, the IHA-holder must immediately cease the specified 
activities until NMFS is able to review the circumstances of the 
incident and determine what, if any, additional measures are 
appropriate to ensure compliance with the terms of the IHA. The IHA-
holder must not resume their activities until notified by NMFS.
    The report must include the following information:
    <bullet> Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    <bullet> Species identification (if known) or description of the 
animal(s) involved;
    <bullet> Condition of the animal(s) (including carcass condition if 
the animal is dead);
    <bullet> Observed behaviors of the animal(s), if alive;
    <bullet> If available, photographs or video footage of the 
animal(s); and
    <bullet> General circumstances under which the animal was 
discovered.

Monitoring Plan Peer Review

    The MMPA requires that monitoring plans be independently peer 
reviewed where the proposed activity may affect the availability of a 
species or stock for taking for subsistence uses (16 U.S.C. 
1371(a)(5)(D)(ii)(III)). Regarding this requirement, NMFS' implementing 
regulations state that upon receipt of a complete monitoring plan, and 
at its discretion, NMFS will either submit the plan to members of a PRP 
for review or within 60 days of receipt of the proposed monitoring 
plan, schedule a workshop to review the plan (50 CFR 216.108(d)).
    NMFS established an independent PRP to review AGDC's Monitoring 
Plan for the planned project in Prudhoe Bay. NMFS provided AGDC's 
monitoring plan to the PRP and asked them to answer the following 
questions:
    1. Will the applicant's stated objectives effectively further the 
understanding of the impacts of their activities on marine mammals and 
otherwise accomplish the goals stated below? If not, how should the 
objectives be modified to better accomplish the goals below?
    2. Can the applicant achieve the stated objectives based on the 
methods described in the plan?
    3. Are there technical modifications to the proposed monitoring 
techniques and methodologies proposed by the applicant that should be 
considered to better accomplish the objectives?
    4. Are there techniques not proposed by the applicant (i.e., 
additional monitoring techniques or methodologies) that should be 
considered for inclusion in the applicant's monitoring program to 
better accomplish the objectives?
    5. What is the best way for an applicant to present their data and 
results (formatting, metrics, graphics, etc.) in the required reports 
that are to be submitted to NMFS (i.e., 90-day report)?
    The PRP met in March 2020 and subsequently provided a final report 
to NMFS containing recommendations that the panel members felt were 
applicable to AGDC's monitoring plan. The panel concluded that the 
objectives are appropriate; however, they provided some recommendations 
to improve AGDC's ability to achieve their stated objectives. The PRP's 
primary recommendations and comments are summarized and addressed 
below. The PRP's full report is available on our website at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.
    The PRP recommended that AGDC station PSOs on elevated platforms to 
increase sighting distance. NMFS agrees, and the final IHA requires 
AGDC to provide elevated monitoring locations for PSOs. The structures 
would vary depending on the construction location.
    The PRP recommended that PSOs focus on scanning the shoreline and 
water, alternately with visual scans and using binoculars, to detect as 
many animals as possible rather than following individual animals for 
any length of time to collect detailed behavioral information. NMFS 
requires PSOs to document and report the behavior of marine mammals 
observed within the Level A and Level B harassment zones. While NMFS 
agrees that PSOs should not document behavior at the expense of 
detecting other marine mammals, particularly within the shutdown zone, 
we are asking PSOs to record an estimate of the amount of time that an 
animal spends in the harassment zone, which is important to help 
understand the likelihood of incurring PTS (given the duration 
component of the thresholds) and the severity of behavioral 
disturbance.
    The PRP recommended that the PSOs record visibility conditions at 
regular intervals (e.g., every five minutes) and as they change 
throughout the day. The panel recommended using either laser range 
finders or a series of ``landmarks''

[[Page 10697]]

at varying distances from each observer. The PRP notes that if AGDC 
uses landmarks, AGDC could measure the distance to the landmarks on the 
ground before pile driving or removal begins, and reference these 
landmarks throughout the season to record visibility. The landmarks 
could be buildings, signs, or other stationary objects on land that are 
located at increasing distances from each observation platform. PSOs 
should record visibility according to the farthest landmark the laser 
range finder can detect or that the PSO can clearly see. In the final 
IHA, NMFS has required AGDC to record visibility conditions throughout 
construction; however, NMFS has required PSOs to record visibility 
every 30 minutes, rather than every five minutes, in an effort to 
minimize distraction from observing marine mammals. PSOs will be 
equipped with range finders, and will establish reference landmarks on 
land.
    The PRP recommended that AGDC have a designated person on site 
keeping an activity log that includes the precise start and stop dates 
and times of each type of construction operation mode. AGDC's field 
lead PSO will record this information during construction.
    The PRP commended AGDC's proposed use and experimentation with NVD 
and IR technology. The panel noted that there are many devices with a 
broad range of capabilities that should be thoroughly understood before 
the experiment is conducted. AGDC will select the most effective 
devices based on surveys of experienced PSOs and literature provided by 
the panel.
    The PRP expressed concern about the limited effective visual 
detection range of the PSOs in comparison with the estimated size of 
the Level A and Level B harassment zones, including AGDC's ability to 
shut down at the proposed distances, and AGDC's ability to estimate 
actual Level A and Level B harassment takes. The panel noted that 
effective sighting distances are likely 200 m for seals, and 1 km for 
mysticetes, based on ship-based PSO observations in the Chukchi Sea 
(LGL et al. 2011). They noted that the effective sighting distance for 
beluga whales may be greater than 200 m, although visibility would 
likely decrease in windy conditions with white caps (DeMaster et al., 
2001). The panel recommended that AGDC implement real-time PAM to 
verify the harassment zone sizes, and to improve detection of marine 
mammals at distances where visual detection probability is limited or 
not possible. The panel recommended that AGDC begin PAM two to three 
weeks prior to the start of construction and continue through two to 
three weeks after construction activities conclude for the season. They 
recommended archival bottom mounted recorders as an alternative to 
real-time PAM, but noted that these setups are not as easy to relocate 
and that data can only be accessed after recovery.
    In a related comment, the panel recommended that AGDC report total 
estimated Level A and Level B harassment takes using two methods. 
First, the panel recommended that AGDC assume that animal density is 
uniform throughout the Level B harassment zone and use distance 
sampling methods, such as Burt et al., 2014, based only on the shore-
based PSO observations to estimate actual takes by Level B harassment. 
Second, the PRP recommended that AGDC also use real-time PAM to 
estimate takes by Level B harassment only in the far field, assuming 
that each acoustic detection that occurs during pile driving or removal 
is a Level B harassment take.
    In consideration of the effective sighting distances included in 
the PRP report, and estimated effective sighting distances from the 
applicant, NMFS has acknowledged the shorter likely sighting distances 
(via the potential takes by Level A harassment considered in the 
analysis) and has included a shutdown zone for phocids during impact 
pile driving of 500 m, as stated herein (and included in the proposed 
IHA), which is expected to be visible to PSOs. While this distance is 
greater than the 200 m estimated by the PRP, shore-based PSOs typically 
have greater visibility. Additionally, AGDC's PSOs will observe from 
elevated locations.
    NMFS did not require AGDC to report Level A and Level B harassment 
takes using distance sampling methods, as NMFS does not believe that it 
is appropriate to apply precise distance sampling methods intended for 
systematic surveys to estimating take numbers in this situation. As 
noted by the panel, the assumption of uniform density throughout the 
Level A and Level B harassment zones is not likely appropriate for this 
project, given varying habitat attributes throughout the zones such as 
distance from the shore and water depth. The pile driving and removal 
activities are likely to further affect the distribution within the 
zones. However, as a simpler alternative to help understand the 
potential exposures within the unseen area, NMFS has required AGDC to 
include an estimation of potential takes by Level A and Level B 
harassment based on the number of observed exposures within the Level A 
or Level B harassment zone and the percentage of the Level A or Level B 
harassment zone that was not visible in their final report.
    The final IHA does not require AGDC to implement real-time PAM (see 
below). However, the final IHA does require AGDC to conduct a SSV at 
the start of construction, and as appropriate, NMFS may update the 
Level A and Level B harassment zones and shutdown zones based on the 
SSV results. Additionally, the final IHA does require AGDC to deploy 
three archival PAM receivers during the open water season (rather than 
a single, archival PAM receiver as stated in the notice of the proposed 
IHA) to collect data that indicates the presence of marine mammals. As 
stated previously, the PRP recommended archival bottom mounted 
recorders as an alternative to real-time PAM, although AGDC will deploy 
these in stationary locations, rather than relocating the receivers for 
various construction activities as recommended by the PRP. If NMFS 
updates the Level B harassment zones following review of the SSV 
results, the hydrophones may be relocated, as described in AGDC's 
monitoring plan. AGDC will implement the majority, if not all, of the 
proposed pile driving and removal during the open water season. Since 
AGDC would need to deploy the PAM system after ice melt, deploying it 
two to three weeks before and after the construction period would 
narrow AGDC's open water work window by at least one month. 
Additionally, while AGDC's construction is occurring within a limited 
timeframe, other companies have operations in the area also, which may 
interfere with the ability to gather baseline data regarding marine 
mammal presence without interference from other industrial activities. 
Marine mammals in the project area are migratory, so presence within 
the work area would change throughout the suggested monitoring period, 
even if AGDC was not conducting the activity. As such, the Final IHA 
requires AGDC to deploy the three archival PAM receivers for three days 
prior to the start of construction, through construction, and for three 
days after completion of construction activities, rather than only 
during the active construction period only as stated in the proposed 
IHA. AGDC will deploy the hydrophones in the locations suggested by the 
PRP as recommended by the PRP and indicated in Figure 4 of AGDC's 
December 2020 4MP. If the Level A and Level B harassment zones are 
updated based on SSV results, the hydrophones may be relocated, as 
appropriate.

[[Page 10698]]

    If construction during the contingency period is necessary, AGDC 
will deploy one overwintering hydrophone at the end of the open-water 
season for monitoring during the contingency period. 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). A location for the contingency 
period hydrophone would be selected closer to construction, and must be 
reviewed by NMFS, the NSB, and the AEWC, and approved by NMFS prior to 
deployment.
    Real-time PAM might be helpful if there were a limited ability to 
detect animals using other methods as required to support the 
implementation of mitigation action, such as shutting down operations 
at the time that a detection occurs. However, in this instance, visual 
monitoring by PSOs can adequately detect marine mammals and minimize 
Level A harassment take, and the authorization includes Level A 
harassment take of ice seals. Further, the operation of real-time PAM 
is significantly more costly than collecting PAM data for later 
analyses, as someone would need to monitor the data in real-time, and 
the PAM buoys would need to be relocated for changes in Level A and 
Level B harassment zone sizes between various pile sizes and 
installation or removal methods. Given the limitations described above, 
and the limited additional detection value added by the addition of 
real-time PAM in these circumstances, implementation of real-time PAM 
is not warranted in light of the associated cost and effort.
    The PRP also recommended that PSOs observations begin 2-3 weeks 
prior to construction, continue through the construction season, and 
continue for 2-3 weeks after the construction season ends. Given that 
ice conditions in the weeks leading up to the construction period will 
differ from that during construction (as will ice seal presence), NMFS 
has required PSOs to observe from shore during the three days before 
construction begins, and for three additional days after the 
construction season ends, rather than 2-3 weeks. During the 
construction season, NMFS has required PSOs to monitor 24 hours per 
day, even during periods without construction.
    The PRP also made recommendations regarding how AGDC should present 
their monitoring data and results. Please refer to part V of the report 
for those suggestions. As stated in the notice of the proposed IHA, 
AGDC will implement the reporting recommendations that do not require 
PAM as stated in the recommendations. At the time of publication of the 
proposed IHA, NMFS was still considering whether reporting 
recommendations h-j were appropriate for inclusion in the IHA. The 
final IHA requires AGDC to conduct the reporting in recommendations i 
and j (report received sound levels, propagation loss, isopleth 
distances and sound source levels, as well as sighting and acoustic 
detection rates summarized into daily or weekly periods for the before, 
during and after construction periods). However, NMFS is not requiring 
AGDC to include maps showing acoustic detections by species and 
construction activity type (part of recommendation h), as AGDC does not 
intend to set the hydrophones up as a localization array, and 
therefore, the data will not be appropriate for reporting specific 
locations of marine mammal detections.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    To avoid repetition, the majority of our analyses apply to all of 
the species listed in Table 16, given that many of the anticipated 
effects of this project on different marine mammal stocks are expected 
to be relatively similar in nature. Where there are meaningful 
differences between species or stocks in anticipated individual 
responses to activities, impact of expected take on the population due 
to differences in population status or impacts on habitat, they are 
described independently in the analysis below.
    Pile driving and removal activities associated with the project, as 
outlined previously, have the potential to disturb or temporarily 
displace marine mammals. Specifically, the specified activities may 
result in take, in the form of Level A and Level B harassment, from 
underwater sounds generated from pile driving and removal. Potential 
takes could occur if individuals of these species are present in zones 
ensonified above the thresholds for Level A or Level B harassment, 
identified above, when these activities are underway. While AGDC may 
pile drive at any time of day (24 hours per day), we do not expect 
noise-producing pile driving will actually occur at all times during a 
24-hour period, given the general construction process, including time 
for setting up piles pile for installation.
    The takes from Level A and Level B harassment will be due to 
potential behavioral disturbance, TTS and PTS. No mortality or serious 
injury is anticipated given the nature of the activity. Level A 
harassment is only anticipated for ringed seal, spotted seal, and 
bearded seal. The potential for Level A harassment is minimized through 
the construction method and the implementation of the required 
mitigation measures (see Mitigation Measures).
    Effects on individuals that are taken by Level B harassment, on the 
basis of reports in the literature as well as monitoring from other 
similar activities, will likely be limited to reactions such as 
increased swimming speeds, increased surfacing time, or decreased 
foraging (if such activity were occurring) (e.g., Thorson and Reyff 
2006; HDR, Inc. 2012; Lerma 2014; ABR 2016). Most likely for pile 
driving, individuals will simply move away from the sound source and be 
temporarily displaced from the areas of pile driving, although even 
this reaction has been observed primarily only in association with 
impact pile driving, which is just a portion of AGDC's construction. 
Level B harassment will be reduced to the level

[[Page 10699]]

of least practicable adverse impact through use of mitigation measures 
described herein. If sound produced by project activities is 
sufficiently disturbing, animals are likely to simply avoid the area 
while the activity is occurring. While vibratory driving associated 
with the project may produce sound at distances of many km from the 
project site, the project site itself is located in an active 
industrial area, as previously described. Therefore, we expect that 
animals disturbed by project sound will simply avoid the area and use 
more-preferred habitats.
    In addition to the expected effects resulting from authorized Level 
B harassment, we anticipate that ringed seals, spotted seals, and 
bearded seals may sustain some limited Level A harassment in the form 
of auditory injury. However, 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 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 dB in its 
hearing sensitivity, which in most cases is not likely to meaningfully 
affect its ability to forage and communicate with conspecifics.
    Habitat disturbance and alteration resulting from project 
activities could have a few highly localized, short-term effects for a 
few marine mammals; however, the area of affected habitat would be 
small compared to that available to marine mammal species. The 
activities may cause some fish to leave the area of disturbance, thus 
temporarily impacting marine mammals' foraging opportunities in a 
limited portion of the foraging range. We do not expect pile driving 
activities to have significant, long-term consequences to marine 
invertebrate populations. Given the short duration of the activities 
and the relatively small area of the habitat that may be affected, the 
impacts to marine mammal habitat, including fish and invertebrates, are 
not expected to cause significant or long-term negative consequences to 
marine mammals or to populations of fish or invertebrate species.
    AGDC's February to April pile driving contingency period overlaps 
with the period when ringed seals are constructing subnivean lairs, 
giving birth, and nursing pups. As discussed in the Mitigation Measures 
section, AGDC will be required to begin construction prior to March 1 
when ringed seals are known to begin constructing lairs. As such, we 
expect that ringed seals will construct their lairs away from the pile 
driving operations, therefore minimizing disturbance and avoiding any 
potential for physical injury to seals in lairs. Additionally, we 
expect that AGDC will complete the majority, if not all of the pile 
driving during the open water season, so any pile driving that did 
remain could likely be completed in the earlier portion of the 
contingency period, further reducing the potential for impacts to 
ringed seals while lairing or pupping.
    As stated in the Description of Marine Mammals in the Area of 
Specified Activities section, since publication of the proposed IHA (85 
FR 43382; July 16, 2020), NMFS published a proposed rule for the 
Designation of Critical Habitat for the Beringia DPS of the Bearded 
Seal (86 FR 1433; January 8, 2021) and a revised proposed rule for the 
Designation of Critical Habitat for the Arctic Subspecies of the Ringed 
Seal (86 FR 1452; January 8, 2021). NMFS considered the information 
provided in each proposed rule, and determined that neither proposed 
rule presents new information that changes NMFS' analyses, the take 
estimates, or any of the findings, for either species.
    As described in the notice of the proposed IHA (85 FR 43382; July 
16, 2020), unusual mortality events (UMEs) have been declared for both 
gray whales and ice seals; however, the take authorized here does not 
provide a cause for concern for any of these populations when 
considered in the context of these UMEs. For gray whales, the estimated 
abundance of the Eastern North Pacific stock is 26,960 (Carretta et 
al., 2019) and the stock abundance has increased approximately 22 
percent in comparison with 2010/2011 population levels (Durban et al., 
2017). For bearded seals, the minimum estimated mean M/SI (6,709) is 
well below the calculated partial PBR (8,210). This PBR is only a 
portion of that of the entire stock, as it does not include bearded 
seals that overwinter and breed in the Beaufort or Chukchi Seas (Muto 
et al., 2019). For the Alaska stock of ringed seals and the Alaska 
stock of spotted seals, the M/SI (863 and 5,254, respectively) is well 
below the PBR for each stock (5,100 and 12,697, respectively) (Muto et 
al., 2019). No serious injury or mortality is expected or authorized 
here, and Level B harassment takes of gray whale and ice seal species, 
and Level A harassment takes of ice seals will be reduced to the level 
of least practicable adverse impact through the incorporation of the 
mitigation measures. As such, the authorized Level B harassment takes 
of gray whales and ice seals and Level A harassment takes of ice seals 
are not expected to exacerbate or compound upon the ongoing UMEs.
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect the species or stock through 
effects on annual rates of recruitment or survival:
    <bullet> No mortality or serious injury is anticipated or 
authorized;
    <bullet> The relatively small number of Level A harassment 
exposures, for seals only, are anticipated to result only in slight PTS 
within the lower frequencies associated with pile driving;
    <bullet> The intensity of anticipated takes by Level B harassment 
is minimized through implementation of the mitigation measures 
described above. While some instances of TTS could occur, the majority 
of Level B harassment takes will likely be in the form of avoidance of 
the project area, temporary cessation of foraging and vocalizing, or 
changes in dive behavior;
    <bullet> The area impacted by the specified activity is very small 
relative to the overall habitat ranges of all species;
    <bullet> The Level B harassment zones do not overlap with known 
important areas for bowhead, gray, or beluga whale, including, 
specifically, any of the BIAs identified in the region (Clarke et al., 
2015);
    <bullet> Impacts to critical behaviors such as lairing and pupping 
by ringed seals would be avoided and minimized through implementation 
of mitigation measures described above; and
    <bullet> AGDC would cease pile driving during the Nuiqsut whaling 
season, therefore minimizing the amount or severity of take of bowhead 
whale during a time where animals are expected to migrate by in 
relatively higher density.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the planned monitoring and 
mitigation measures, NMFS finds 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

    As noted above, only small numbers of incidental take may be 
authorized under Sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers

[[Page 10700]]

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.
    The number of instances of take for each species or stock 
authorized to be taken as a result of this project is included in Table 
16. 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 at most less than two 
percent of the abundance for all affected stocks). The number of 
animals authorized 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.
    For beluga whale, the percentages in Table 16 conservatively assume 
that all takes of beluga whale will be accrued to each stock; however, 
we expect that most, if not all, beluga whales taken by this project 
will be from the Beaufort Sea stock.
    For the Alaska stock of bearded seals, a complete stock abundance 
value is not available. As noted in the 2019 Draft Alaska SAR (Muto et 
al., 2019), an abundance estimate is currently only available for the 
portion of bearded seals in the Bering Sea (Conn et al., 2012). The 
current abundance estimate for the Bering Sea is 301,836 bearded seals. 
Given the authorized 300 Level B harassment takes and 2 Level A 
harassment takes for the stock, comparison to the Bering Sea estimate, 
which is only a portion of the Alaska Stock (which also includes 
animals in the Chukchi and Beaufort Seas), shows that, at most, less 
than one percent of the stock is expected to be impacted.
    A complete stock abundance value is also not available for the 
Alaska stock of ringed seals. As noted in the 2019 Draft Alaska SAR 
(Muto et al., 2019), the abundance estimate available, 171,418 animals, 
is only a partial estimate of the Bering Sea portion of the population 
(Conn et al., 2014). As noted in the SAR, this estimate does not 
include animals in the shore fast ice zone, and the authors did not 
account for availability bias. Muto et al. (2019) expect that the 
Bering Sea portion of the population is actually much higher. Given the 
authorized 1,765 Level B harassment takes and 9 Level A harassment 
takes for the stock, comparison to the Bering Sea partial estimate, 
which is only a portion of the Alaska Stock (also includes animals in 
the Chukchi and Beaufort Seas), shows that, at most, less than two 
percent of the stock is expected to be impacted.
    Based on the analysis contained herein of the planned activity 
(including the planned mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS finds that small numbers of 
marine mammals will be taken relative to the population size of the 
affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    In order to issue an IHA, NMFS must find that the specified 
activity will not have an ``unmitigable adverse impact'' on the 
subsistence uses of the affected marine mammal species or stocks by 
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50 
CFR 216.103 as an impact resulting from the specified activity: (1) 
That is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by: (i) Causing 
the marine mammals to abandon or avoid hunting areas; (ii) Directly 
displacing subsistence users; or (iii) Placing physical barriers 
between the marine mammals and the subsistence hunters; and (2) That 
cannot be sufficiently mitigated by other measures to increase the 
availability of marine mammals to allow subsistence needs to be met.
    Given the nature of the activity, and the required mitigation 
measures, serious injury and mortality of marine mammals is not 
expected to occur. Impacts to marine mammals would mostly include 
limited, temporary behavioral disturbances of seals, however, some 
slight PTS in seals within the lower frequencies associated with pile 
driving is possible. Additionally, a small number of takes of bowhead 
whales, by Level B harassment only, are predicted to occur in the 
vicinity of AGDC's activity. As described above, the required 
mitigation measures, such as implementation of shutdown zones, are 
expected to reduce the frequency and severity of takes of marine 
mammals.
    Project activities could deter target species from Prudhoe Bay and 
the area ensonified above the relevant harassment thresholds. However, 
as noted in the Effects of Specified Activities on Subsistence Uses of 
Marine Mammals section, subsistence use of seals is extremely limited 
in this area, as it is not within the preferred and frequented hunting 
areas. Bowhead whales typically remain outside of the area between the 
barrier islands and Prudhoe Bay, minimizing the likelihood of impacts 
from AGDC's project. The authorized takes are not expected to affect 
the fitness of any bowhead whales, or cause significant deflection 
outside of the typical migratory path in areas where subsistence hunts 
occur. Additionally, during the Nuiqsut whaling season, the final IHA 
requires AGDC to cease pile driving and project vessels must transit 
landward of Cross Island, therefore minimizing the potential impact to 
the Nuiqsut hunt. AGDC will continue to coordinate with local 
communities and subsistence groups to minimize impacts of the project, 
as described in the POC, which the IHA requires AGDC to abide by.
    Based on the description of the specified activity and the 
potential impacts described in the Effects of Specified Activities on 
Subsistence Uses of Marine Mammals section, the measures described to 
minimize adverse effects on the availability of marine mammals for 
subsistence purposes, as well as the mitigation measures required to 
directly reduce impacts to the affected species and stocks, NMFS has 
determined that there will not be an unmitigable adverse impact on 
subsistence uses from AGDC's planned activities.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an IHA) 
with respect to potential impacts on the human environment. 
Accordingly, NMFS adopted the FERC's EIS, as our independent evaluation 
of the document finds that it includes adequate information analyzing 
the effects on the human environment of issuing the IHA. NMFS is a 
cooperating agency on the FERC's EIS.
    The FERC's EIS was made available for public comment from June 28, 
2019 to October 3, 2019. The FERC's Final EIS is available at https://www.ferc.gov/industries/gas/enviro/eis/2020/03-06-20-FEIS.asp.

Endangered Species Act

    Section 7(a)(2) of the Endangered Species Act of 1973 (16 U.S.C. 
1531 et seq.) requires that each Federal agency insure that any action 
it authorizes, funds, or carries out is not likely to

[[Page 10701]]

jeopardize the continued existence of any endangered or threatened 
species or result in the destruction or adverse modification of 
designated critical habitat. To ensure ESA compliance for the issuance 
of IHAs, NMFS consults internally whenever we propose to authorize take 
for endangered or threatened species, in this case with the AKRO.
    NMFS authorized take of bowhead whale, bearded seal (Beringia 
distinct population segment) and ringed seal (Arctic subspecies), which 
are listed under the ESA. On January 8, 2021, NMFS published a proposed 
rule for the Designation of Critical Habitat for the Beringia DPS of 
the Bearded Seal (86 FR 1433; January 8, 2021) and a revised proposed 
rule for the Designation of Critical Habitat for the Arctic Subspecies 
of the Ringed Seal (86 FR 1452; January 8, 2021). Neither ESA critical 
habitat rule has been finalized.
    The NMFS AKRO issued a Biological Opinion under section 7 of the 
ESA, on the issuance of an IHA to AGDC under section 101(a)(5)(D) of 
the MMPA by the NMFS Office of Protected Resources. The Biological 
Opinion concluded that the action is not likely to jeopardize the 
continued existence of any of these species.

Authorization

    NMFS has issued an IHA to AGDC for the potential harassment of 
small numbers of six marine mammal species incidental to construction 
of the AK LNG project in Prudhoe Bay, Alaska, provided the previously 
mentioned mitigation, monitoring and reporting requirements are 
followed.

    Dated: February 16, 2021.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2021-03472 Filed 2-19-21; 8:45 am]
BILLING CODE 3510-22-P