Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Construction of the Port of Alaska's Petroleum and Cement Terminal, Anchorage, Alaska, 19294-19324 [2020-07106]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 85, Number 66 (Monday, April 6, 2020)]
[Notices]
[Pages 19294-19324]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-07106]



[[Page 19293]]

Vol. 85

Monday,

No. 66

April 6, 2020

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 Construction of the Port of Alaska's 
Petroleum and Cement Terminal, Anchorage, Alaska; Notice

Federal Register / Vol. 85 , No. 66 / Monday, April 6, 2020 / 
Notices

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XR027]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Construction of the Port of 
Alaska's Petroleum and Cement Terminal, Anchorage, Alaska

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; issuance of incidental harassment authorizations.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that we have issued two successive incidental harassment authorizations 
(IHA) to the Port of Alaska (POA), authorizing the take of small 
numbers of marine mammals incidental to construction of the Petroleum 
and Cement Terminal (PCT), Anchorage, Alaska.

DATES: The Phase 1 IHA is effective April 1, 2020 through March 31, 
2021. The Phase 2 IHA is effective April 1, 2021 through March 31, 
2022.

FOR FURTHER INFORMATION CONTACT: Jaclyn Daly, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION: 

Availability

    Electronic copies of the POA's application, issued IHAs, 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.

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. Under the MMPA, ``take'' is defined as meaning to harass, 
hunt, capture, or kill, or attempt to harass, hunt, capture, or kill 
any marine mammal.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of such species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of such 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 November 28, 2018, NMFS received a request from the POA for an 
IHA to take marine mammals incidental to pile driving associated with 
the construction of the PCT. The POA submitted a new application on 
July 19, 2019 due to a modified construction schedule (two phases 
instead of one) and a revised application on August 9, 2019. We deemed 
the application adequate and complete on August 28, 2019. The POA 
submitted a subsequent revised application on October 15, 2019, which 
is available at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. The POA's request is 
for take of small numbers of six species of marine mammals, by Level B 
harassment. Four of the species could also be taken by Level A 
harassment. Neither the POA nor NMFS expects serious injury or 
mortality to result from this activity; therefore, an IHA is 
appropriate.
    NMFS previously issued IHAs and Letters of Authorization (LOAs) to 
the POA for pile driving (73 FR 41318, July 18, 2008; 74 FR 35136, July 
20, 2009; and 81 FR 15048; March 21, 2016). The POA complied with all 
the requirements (e.g., mitigation, monitoring, and reporting) of all 
previous incidental take authorizations and did not exceed authorized 
take. Summaries of previous monitoring reports may be found in the 
Effects of the Specified Activity on Marine Mammals and their Habitat 
and Estimated Take sections.

Description of Proposed Activity

    We provided a detailed description of the POA's PCT activities in 
the notice of proposed IHAs (84 FR 72154, December 30, 2019). Since 
that time, the POA has modified the design. While the overall plan for 
the terminal layout and construction methods are the same, the POA has 
considered NMFS's recommendations during the proposed IHAs phase and 
made the following adjustments. In February, 2020, the POA indicated to 
NMFS they have removed the use of battered piles in Phase 1. As 
indicated in the notice of proposed IHAs, a bubble curtain could not be 
used on battered piles due to the angle of their installation. With the 
removal of battered piles from Phase 1, all piles in Phase 1 will now 
be plumb and be installed and removed using a bubble curtain. The POA 
retains installing six 24-inch (in) battered piles in Phase 2 but will 
continue to investigate if these can be replaced with plumb piles. 
Although our analysis related to the Phase 2 IHA assumes that these six 
piles will be battered piles and therefore installed without use of the 
bubble curtain, it is possible that this will change and the effects 
associated with installation of those piles will be less than what is 
analyzed herein. The POA has also indicated to NMFS it is likely going 
to reduce the number of temporary piles in Phase 1 by approximately 11 
piles; however, in the case of unforeseen circumstances, those 
additional piles may be necessary. Therefore, despite the POA likely 
driving and removing 11 fewer piles in Phase 1, we have continued to 
evaluate the project based on the original total number of piles.
    A significant change in POA's project is the use of a confined 
bubble curtain in Phase 1. This confined bubble curtain is expected to 
result in less noise propagating into the marine environment than an 
unconfined system. Despite the expected reduction of noise, we maintain 
the estimated source levels used in the notice of proposed IHAs, 
meaning that our analysis likely represents an overestimate of 
potential effects. We have updated the pile details (Table 1) and 
included a detailed description of the confined bubble curtain below.

[[Page 19295]]



                         Table 1--PCT Construction Pile Details and Estimated Effort Required for Pile Installation and Removal
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                                                                                                                         Production
                                                       Total      Average    Vibratory                        Estimated      rate          Days of
     Pipe pile       Structural  feature    Number     number    embedded     duration   Impact strikes  per     total   piles  per   installation  and
     diameter                              of piles   of piles     depth      per pile           pile           number       day           removal
                                                                  (feet)     (minutes)                         of hours    (range)
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                                                                         Phase 1
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48-in.............  Loading Platform....         45         71         100           30  2,300 (50 restrikes         73         1.5  30.
                                                                                    10%   each for 4 piles).                  (1-3)
                                                                             (7 piles):
                    Access Trestle......         26                    130               3,000 (50 restrikes         56              17.
                                                                                          each for 3 piles).
36-in.............  Temporary                    26         30         115           75  50 restrikes for 10         33           3  9 installation.
                     Construction Work                                                    piles.                              (2-4)  9 removal.
                     Trestle.
                    Temporary Derrick             4                     40           75  NA.................          5           4  1 installation.
                     Barge/Vessel                                                                                                    1 removal.
                     Mooring.
24-in.............  Temporary                    34         81         140           75  50 restrikes for 10         90           3  15 installation.
                     Construction Work                                                    piles.                              (2-4)  15 removal.
                     Trestle.
                    Temporary                    38                    105           75  NA.................         90           3  12 installation.
                     Construction Access                                                                                      (2-4)  12 removal.
                     Trestle and Loading
                     Platform Templates.
                    Temporary mooring             9                     50           30  NA.................         12           3  3 installation.
                     for construction                                                                                                3 removal.
                     vessels.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Phase 1 Construction Totals........................  182 piles  ..........  ...........  ...................        359  ..........  127.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         Phase 2
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24-in.............  Temporary Dolphins            3          9          50           30  NA.................          3           3  1 installation.
                     for mooring                                                                                                     1 removal.
                     construction
                     vessels.
                    Temporary Dolphins            6                     50           30  NA.................          9           3  2 installation.
                     for mooring                                                                                                     2 removal.
                     construction
                     vessels, Battered.
36-in.............  Temporary                    72         76         115           75  NA.................        180           3  24 installation.
                     Construction                                                                                             (2-4)  24 removal.
                     Dolphin Template.
                    Temporary Derrick             4                     40           75  NA.................          5           4  1 installation.
                     Barge.                                                                                                          1 removal.
144-in............  Mooring Dolphin.....          6          9         140           45  5,000 (1,500 first          21         0.5  13.
                                                                                    10%   day, 3,500 second
                                                                               (1 pile)   day).
                    Breasting Dolphin...          3                    135                                           11     (0.3 or  6.
                                                                                                                               0.7)
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Phase 2 Construction Totals........................   94 piles  ..........  ...........  ...................        229  ..........  75.
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    PCT Construction Totals \e\....................  276 piles  ..........  ...........  ...................        588  ..........  202 days of
                                                                                                                                      installation and
                                                                                                                                      removal.
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    The estimated source levels for each pile type and installation 
method are provided in Table 2. These source levels are from the 
acoustic monitoring during the POA's 2016 Test Pile Program (TPP) (for 
48-in piles) and investigation of existing literature related to 
studies at other locations for non-48-in piles. We note the source 
level measured during installation of the 48-in piles was actually less 
than that used here (approximately 190 dB) and the POA is now confining 
the bubble curtain with a solid pile. However, as a conservative 
approach to our analysis, we are assuming higher source levels here. We 
note that the hydroacoustic monitoring plan will commence as soon as 
pile driving begins; therefore, any necessary modifications to 
harassment isopleths will be made within the first weeks of pile 
driving, when marine mammal presence in the project area is low.

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                                         Table 2--Estimated Pile Source Levels With and Without Bubble Curtains
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              Method and pile size                                        Sound level at 10 m
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                                                            Unattenuated                    Bubble curtain \1\                    Data source
                   Vibratory                    ----------------------------------------------------------------------
                                                               db rms                     7 dB reduction, dB rms
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144-in.........................................                               178                                171   Caltrans 2015.
48-in..........................................                               168                                161   Austin et al. 2016.
36-in..........................................                               166                                159   Navy 2015.
24-in..........................................                               161                                154   Navy 2015.
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                                         Unattenuated                    Bubble curtain
            Impact            ------------------------------------------------------------------
                                 dB rms     dB SEL    dB peak     dB rms     dB SEL    dB peak
----------------------------------------------------------------------------------------------------------------
144-in.......................        209        198        220        202        191        213  Caltrans 2015.
48-in........................        200        187        215        193        180        208  Austin et al.
                                                                                                  2016.
36-in........................        194        184        211        187        177        204  Navy 2015.
24-in........................        193        181        210        186        174        203  Navy 2015.
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\1\ In Phase 1, POA will drive all piles with a confined bubble curtain.

Bubble Curtain

    In Phase 1, the POA, at the request of NMFS, has further improved 
their bubble curtain design to include a confined bubble curtain. If 
this system is proven successful through hydroacoustic monitoring, the 
POA and NMFS will consult to determine if its use in Phase 2 is 
appropriate. The POA has indicated this system may be used in Phase 2; 
however, at this time, NMFS is limiting its required use to Phase 1. 
For Phase 1 PCT construction, the construction contractor has provided 
a detailed confined bubble curtain system, as discussed below. For 
Phase 2 PCT construction, the construction contractor is not scheduled 
to be selected until approximately the third quarter of 2020; 
therefore, a similar level of detail and specificity is not currently 
available. NMFS will continue to work with POA during 2020 and final 
bubble curtain requirements will be made prior to work commencing in 
April 2021 pending review of success in Phase 1. However, at minimum, 
an unconfined bubble curtain is required on installation and removal of 
all plumb piles (i.e., all piles except for the six battered piles) 
during Phase 2.
    During the PCT Project, an air bubble curtain noise attenuation 
system (bubble curtain) will be used during installation and removal of 
all plumb piles when water depth is great enough (approximately 3 m) to 
deploy the bubble curtain. If the six battered piles (piles installed 
at an angle) are used in Phase 2, a bubble curtain will not be used due 
to the angle of installation. It may not be possible to use a bubble 
curtain on piles installed or removed in shallow water and piles 
installed or removed ``in the dry,'' (e.g., when piles are installed 
above the water line). The tides at the POA have a mean range of about 
8.0 meters (26 feet)(NOAA 2019), and low water levels will prevent 
proper deployment and function of the bubble curtain system. When the 
water is too shallow for deployment of a bubble curtain, the harassment 
zones for unattenuated impact pile installation will be monitored.
    For Phase 1, the POA will use a confined bubble curtain on all 
piles. We note a confined system was briefly tested during the 2016 TPP 
project; however, the sleeve (or pile casing) used during that test 
contained gaps that likely contributed to less sound absorption. Here, 
the sleeve is a solid steel pile; therefore, no gaps are present.
    The bubble curtain air flows and annular space will conform to the 
guidance outlined in the National Marine Fisheries Service and U.S. 
Fish and Wildlife Service, Washington Fish and Wildlife Office document 
dated October 31, 2006 titled ``Impact Pile Driving Sound Attenuation 
Specification'' (USFWS 2006).
    In Phase 1, all 24-in diameter temporary piles will have a 48-in 
diameter confinement casing, and all 36-in diameter temporary piling 
will have a 60-in diameter confinement casing. Multiple confinement 
casings with bubble curtain hardware will be employed to the extent 
required if multiple pile driving is occurring concurrently. Temporary 
piles and the confinement casing, with installed bubble curtain 
hardware, will be lofted together with the piles in a concentric 
arrangement, and allowed to drop onto the seafloor. The weight of the 
configuration will embed the arrangement into the seafloor at an 
estimated shallow depth. The specific depth of penetration from self-
weight varies depending on water depth, substrate, weight of pile, 
tidal stage resistance, and other physical factors present, but the 
contractor has estimated a minimum of a couple or few feet.
    There will be an arrangement of spacers that center the piling 
within the confinement casing. These spacers will likely be resilient 
materials such as rubber spacers or air filled cushions, as called out 
in the USFWS/NMFS Bubble Curtain Specifications, to prevent metal-to-
metal contact between the confinement casing and the pile. The amount 
of self-weight penetration into sediment is somewhat variable but is 
expected to be several feet. The lowest bubble ring will be within one 
to two feet of the seafloor. Figure 1 illustrates this concentric 
arrangement.
    Once the bubble curtain is operational, the temporary pile will be 
driven with a combination of vibratory and impact methods within the 
confinement casing; after pile driving, the confinement casing will be 
lifted off of the temporary pile. For removal of the temporary piling, 
the confinement casing, with installed bubble curtain, will be re-
deployed over the pile. The temporary piles will be removed with a 
vibratory hammer while the bubble curtain is operational. Once the 
temporary pile is extracted, both the temporary pile and bubble curtain 
sleeve will be removed at the same time. A vibratory hammer will not be 
required to remove the bubble curtain sleeve--it will be directly 
pulled.

[[Page 19297]]

[GRAPHIC] [TIFF OMITTED] TN06AP20.001

    The 48-in piles are much heavier and longer than the 24- and 36-in 
piles; therefore, the method of lofting the 48-in piles and concentric 
confinement casing together is not feasible. The 48-in piles in Phase 1 
will be fitted with a 72-in diameter confinement casing. The 
confinement casing with installed bubble curtain hardware will be 
lofted through a template to the sea floor and then will be driven to a 
nominal depth of 10 feet using vibratory methods.
    To install the casing piles when driving the 48-in piles, a 
vibratory hammer may be used. However, this would occur for a very 
limited amount of time (one to three minutes per confinement casing) 
with a total maximum time of less than four hours during Phase 1 (April 
through November). This is a very short duration of unattenuated 
vibratory sound in contrast to the estimated 129 hours of impact 
driving using this noise attenuation system, which is expected to be 
highly effective. Use of a vibratory hammer is necessary in order to 
stabilize the pile using the sea floor embedment and the template, so 
that the confinement casing can be released from the crane without 
endangering personnel or property. Once the confinement casing is in 
place, the permanent pile will be lofted through the casing and allowed 
to self-weight into the sea floor. The bubble curtain will be activated 
and then the permanent pile will be driven using impact methods (or 
vibratory methods in cases of pile driving difficulties or obstructions 
as discussed elsewhere in the work description). After driving to 
depth, the confinement casing will be lifted off of the pile. This will 
not require vibratory energy to remove because of the shallow 
embedment. Figure 2 illustrates the arrangement for installation of the 
permanent piles and confinement system.

[[Page 19298]]

[GRAPHIC] [TIFF OMITTED] TN06AP20.002

    A certain number of the 48-in piles will require a short duration 
re-strike pile driving event to prove pile axial capacity (or the 
maximum load which the pile can carry without failure or excessive 
settlement of the ground). This is planned for up to seven events. For 
these events the confinement casing will be lowered over the permanent 
pile and allowed to self-weight into the sea floor sediments; the 
bubble curtain will be activated and then the pile re-struck with the 
impact hammer. Once the axial capacity is determined, the confinement 
casing will be lifted off of the pile. During restrikes, the 
confinement casing doesn't need to be vibratory hammered in because the 
permanent pile will provide a safe condition since the bubble curtain 
sleeve can be set onto the rigidity of the permanently installed 48-in 
pile. The sleeve will not need to be free standing as in the case of 
initial installation.
    Mitigation, monitoring, and reporting measures are described in 
detail later in this document (please see Mitigation and Monitoring and 
Reporting sections below).

Changes From Proposed to Final

    As described above, the POA has made some modifications to the work 
plan (e.g., confined bubble curtain and all plumb piles for Phase 1); 
however, we have determined that our original acoustic assessment, as 
described in the notice of proposed IHAs remains an accurate approach 
to estimate potential impacts to marine mammals and their habitat, with 
the exception of impact driving 48-in piles, for which we have adjusted 
the Level B harassment zone from 629 m to 824 m based on data contained 
within Austin et al. (2016).

[[Page 19299]]

This is a conservative approach as the confined bubble curtain will 
likely further reduce noise propagation beyond that measured with the 
bubble curtains used during the TPP (Austin et al., 2016). We also note 
that this change does not affect our take numbers because our estimate 
does not rely on the size of the Level B harassment zones for any 
species (see Estimated Take section). Finally, as described in the 
notice of proposed IHAs, hydroacoustic monitoring will commence at the 
onset of pile driving; therefore, any shutdown and monitoring zones may 
be adjusted promptly after the initial interim report.
    NMFS also corrected an error in the take table for humpback whales. 
The text in the notice of proposed IHAs indicated we were authorizing 5 
humpback whale takes in Phase 2 (75 days x 1 whale every 16 days), but 
we mistakenly indicated a total of six humpback whales in the take 
table. The take tables have been adjusted in both this final notice and 
the Phase 2 IHA.
    Finally, NMFS has clarified some of the mitigation measures in the 
final IHAs, and the POA will now employ a fourth monitoring station at 
Ship Creek to further ensure marine mammal detections. In addition, if 
POA is conducting non-PCT-related in-water work that includes PSOs, the 
PCT PSOs must be in real-time contact with those PSOs, and both sets of 
PSOs must share all information regarding marine mammal sightings with 
each other. The POA has also updated its hydroacoustic monitoring plan 
to include more specific goals relevant to the project (e.g., removed 
bubble curtain effectiveness tests and refined locations of hydrophones 
and sampling methods), and NMFS is requiring all in-water work 
occurring in the area during PCT hydroacoustic monitoring (e.g., 
dredging, other in-water work at the POA, vessel transit) to be 
documented (e.g., type of activity, location relative to recordings, 
date/time) and reported in the acoustic monitoring report.

Comments and Responses

    A notice of NMFS' proposal to issue two successive IHAs to POA was 
published in the Federal Register on December 30, 2019 (84 FR 72154). 
That notice described, in detail, POA's proposed activity, the marine 
mammal species that may be affected by the activity, the anticipated 
effects on marine mammals and their habitat, proposed amount and manner 
of take, and proposed mitigation, monitoring and reporting measures. 
During the 30-day public comment period, NMFS received comment letters 
from the Marine Mammal Commission (Commission) and the Center for 
Biological Diversity (CBD). A summary of each comment and our full 
response is provided here. Full comments have been posted online at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. Please see the 
comment letters for full detail of the comments and underlying 
justification.
    We note that the Defenders of Wildlife (Defenders) submitted 
comments to NMFS on February 21, 2020, approximately 3 weeks after the 
close of the comment period. Although NMFS is not obligated to consider 
comments submitted following the close of the comment period, we 
reviewed the letter for pertinent information. Defenders questioned our 
negligible impact and small numbers findings; however, we have 
addressed similar concerns in our response to comments from the 
Commission and CBD. We have also updated the EA so that it accurately 
reflects our impact and take estimate analysis described in the IHAs 
(e.g., consideration of group size in beluga whale take estimates) and 
provides a more comprehensive cumulative impact section. Overall, the 
Defenders letter does not provide information that leads us to change 
our analysis or findings and we do not address the comments 
individually here.
    Comment 1: The Commission recommends that, in the Federal Register 
notice for POA's authorization, if issued, and all future Federal 
Register notices involving the taking of species that also are hunted 
for subsistence purposes, NMFS (1) include the standard verbiage 
regarding the definitions of unmitigable adverse impact under NMFS's 
implementing regulations; (2) specify whether the proposed activities 
overlap in time and space with known hunting activities, whether the 
local Native Alaskan communities that hunt marine mammals were 
contacted, whether any concerns were conveyed, whether additional 
mitigation measures are necessary, and whether a Plan of Cooperation 
(POC) is being or was developed; and (3) if a POC is necessary, ensure 
that it contains all of the relevant information.
    Response: NMFS has included the standard definition of unmitigable 
adverse impact, as suggested by the Commission. The information 
regarding subsistence use for each affected species was contained 
within the notice of proposed IHAs, specifically noting which species 
are not hunted (i.e., Cook Inlet beluga whale (CIBW), humpback whales, 
killer whales, and harbor porpoise) and which are taken by subsistence 
hunters (i.e., harbor seals, Steller sea lions)--see Description of 
Marine Mammals and Their Habitat section in that notice. In addition to 
the information in the Proposed Mitigation section of the proposed 
notice (including background on how mitigation for subsistence use is a 
consideration), we included an evaluation of how we reached our 
determination in the Unmitigable Adverse Impact Analysis and 
Determination section. We have included additional information to more 
clearly relate the information in the Description of Marine Mammals and 
Their Habitat section with our determinations in this final notice of 
issuance; however, our findings remain the same. Regarding time and 
space overlap of subsistence hunts with the activity, Cook Inlet 
subsistence activities that may overlap with the POA activities were 
described in the Description of Marine Mammals in the Area of Specified 
Activities section of the Federal Register notice of proposed IHAs (84 
FR 72161, December 30, 2019) and we refer the reader to that 
information.
    The Commission also recommended we include information about 
whether local Native Alaskan communities that hunt marine mammals were 
contacted, any concerns were conveyed, whether a Plan of Cooperation 
(POC) was being developed and whether additional mitigation measures 
are necessary. For this project, on January 9, 2020, the POA informed 
NMFS that they sent a letter to 14 tribes informing them of the public 
comment period on the proposed IHAs. No tribal comments were received. 
No POC was necessary or developed for this action.
    Comment 2: The Commission provided the following comments related 
to the issuance of incidental take authorizations in Cook Inlet where 
take of beluga whales is proposed for authorization. These are (1) NMFS 
defer issuance of the final incidental harassment authorizations to POA 
or any other applicant proposing to conduct sound-producing activities 
in Cook Inlet until NMFS has a reasonable basis for determining that 
authorizing any additional incidental harassment takes of Cook Inlet 
beluga whales would not contribute to or exacerbate the stock's 
decline; (2) NMFS defer issuance of POA's final incidental harassment 
authorizations until all activities for which incidental take 
authorizations or regulations have been or are expected to be issued 
are considered with respect to their anticipated, cumulative take of 
Cook Inlet beluga whales, as part of a

[[Page 19300]]

PEIS; and (3) Given the number of sound-producing activities expected 
to occur in Cook Inlet and the potential impact of such activities on 
beluga whales, the Commission also reiterates its recommendation that 
NMFS establish annual limits on the total number and types of takes 
that are authorized for all sound-producing activities in Cook Inlet 
before issuing the final authorizations.
    Response: In accordance with our implementing regulations at 50 CFR 
216.104(c), we use the best available scientific evidence to determine 
whether the taking by the specified activity within the specified 
geographic region will have a negligible impact on the species or stock 
and will not have an unmitigable adverse impact on the availability of 
such species or stock for subsistence uses. Based on the scientific 
evidence available, NMFS determined that the impacts of the authorized 
take incidental to pile driving would result in a negligible impact and 
no unmitigable adverse impact on availability of marine mammals for 
subsistence uses. Moreover, NMFS has required rigorous mitigation and 
monitoring measures in the IHAs to reduce impacts to CIBWs, including 
use of a bubble curtain, shutdown at the Level B harassment zone if 
pile driving is occurring, and establishing a pre-pile driving 
clearance zone (i.e., the area must be clear before pile driving 
commences) that essentially encompasses all of lower Knik Arm and 
beyond into upper Cook Inlet. These noise attenuation devices and CIBW 
shutdown measures are more restrictive than the standard shutdown 
measures typically applied. These measures are expected to reduce both 
the scope and severity of potential harassment takes by transmitting 
less noise into the marine environment and reducing the potential for 
exposure above harassment thresholds. In addition to the mitigation 
measures, the POA will monitor from elevated platforms at four 
locations dispersed throughout lower Knik Arm. All stations will have 
at least two NMFS-approved observers on-watch at any given time. 
Therefore, marine mammal detection effectiveness is expected to be 
high.
    Further, as described in the Federal Register notice of proposed 
IHAs (84 FR 72154, December 30, 2019), data from several years of 
scientific monitoring at the POA during previous work involving pile 
driving (occurring April through November) demonstrate there is no 
significant difference in beluga whale sightings during and in absence 
of pile driving (Kendell and Cornick, 2016). While we do anticipate 
some behavioral modifications to occur, these will likely be limited to 
increased travel speeds, reduced vocalizations, and potentially 
traveling in more cohesive groups (Kendell and Cornick, 2016). However, 
we anticipate behavior will return to normal after the whales move past 
the POA (e.g., when they reach productive foraging grounds north of the 
POA) as these areas would not be ensonified by pile driving noise. 
There is no evidence beluga whales have abandoned foraging in Knik Arm 
due to pile driving noise or exposure to pile driving noise has 
resulted in more than a negligible impact to the CIBW population. In 
light of the mitigation and monitoring measures and scientific data to 
date, we anticipate the impacts of any harassment to CIBWs will be 
limited to short-term, mild to moderate behavioral changes and will not 
affect the fitness of any individuals. Therefore, NMFS has a reasonable 
basis for determining that authorizing take incidental to the PCT 
project will not contribute to or exacerbate the stock's decline. 
Additionally, the ESA Biological Opinion determined that the issuance 
of the IHAs is not likely to jeopardize the continued existence of the 
CIBWs or destroy or adversely modify CIBW critical habitat.
    The cumulative effects of the incremental impact of the proposed 
action when added to other past, present, and reasonably foreseeable 
future actions (as well as the effects of climate change) were 
evaluated against the appropriate resources and regulatory baselines in 
our final Environmental Assessment (EA) for the issuance of the IHAs to 
the POA (available at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities). The best available science and a comprehensive review of 
past, present, and reasonably foreseeable actions (including other 
noise-generating activities such as other construction projects and oil 
and gas exploration in Cook Inlet) was used to develop the Cumulative 
Impacts analysis. This analysis is contained in Chapter 4 of the 
aforementioned EA. As required under NEPA, the level and scope of the 
analysis is commensurate with the scope of potential impacts of the 
action and the extent and character of the potentially impacted 
resources, as reflected in the resource-specific discussions in Chapter 
3 (Affected Environment) of the EA. Past and present actions are also 
included in the analytical process as part of the affected 
environmental baseline conditions presented in Chapter 3 of the EA, in 
accordance with 1997 Council on Environmental Quality (CEQ) guidance. 
Per the guidance, a qualitative approach and best professional judgment 
are appropriate where precise measurements are not available. Where 
precise measurements and/or methodologies were available they were 
used. Therefore, NMFS has analyzed the cumulative effects of the action 
on CIBWs (as recommended by the Commission) which supports a Finding of 
No Significant Impact (FONSI). Therefore, an EIS is not required.
    We do recognize, however, that NMFS previously declared its intent 
to prepare an EIS to address MMPA Incidental Take Authorizations (ITAs) 
for oil and gas activities in Cook Inlet, Alaska (79 FR 61616; October 
14, 2014). However, in a 2017 Federal Register notice (82 FR 41939; 
September 5, 2017), NMFS indicated that due to a reduced number of ITA 
requests in the region, combined with funding constraints at that time, 
we were postponing any potential preparation of an EIS for oil and gas 
activities in Cook Inlet. As stated in the 2017 Federal Register 
notice, should the number of ITA requests (for any type of activities), 
or anticipated requests, notably increase, NMFS will re-evaluate 
whether preparation of an EIS is necessary. Currently, the number of 
ITA requests for activities that may affect marine mammals in Cook 
Inlet is at such a level that preparation of an EIS is not necessary. 
Nonetheless, as described above, under NEPA, NMFS is required to 
consider cumulative effects of other potential activities in the same 
geographic area, and these are discussed in greater detail in the Final 
EA prepared for this issuance of two successive IHAs to POA for the PCT 
project, which supports our finding that NMFS' issuance of the POA IHAs 
will not have a significant impact on the human environment.
    With respect to capping the number of takes authorized across all 
activities, the MMPA states that, upon request, NMFS shall authorize, 
for periods of not more than one year, the incidental taking by 
harassment of small numbers of marine mammals if NMFS finds that such 
harassment during each period concerned will have a negligible impact 
on such species or stocks and will not have an unmitigable adverse 
impact on the availability of such species or stocks for taking for 
subsistence uses. Section 101(a)(5)(A) of the MMPA addresses the 
analysis and authorization of take from a ``specified activity'' and, 
therefore, setting limits on the number and types of CIBW takes across 
all activities in Cook Inlet would not be an appropriate requirement of 
an MMPA incidental

[[Page 19301]]

take authorization. Further, NMFS here 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 relevant stressors (such as incidental mortality in 
commercial fisheries, UMEs, and subsistence hunting)). See the 
Negligible Impact Analyses and Determinations section of this notice of 
issuance.
    Separately, setting blanket take limits may not be meaningful, as 
the nature and intensity of impacts from a given activity can vary 
widely. For example, an animal exposed to noise levels just above our 
harassment threshold in a non-critical area may experience a small 
behavioral change with no biological consequence while an animal 
exposed to very loud noise levels (but lower than levels that would 
result in PTS) in an area where active critical foraging occurs could 
result in behavioral changes that may be more likely to impact fitness. 
While both of these examples would be characterized as Level B 
harassment, the resulting impact on the population could be different. 
Context differences such as these are analyzed in our negligible impact 
analysis for each application under the MMPA.
    As described above, this does not mean the cumulative impacts of 
other actions are not considered, as we have captured past and current 
actions in our baseline under the MMPA and all past, present and 
reasonably foreseeable future actions under NEPA. Finally, the 
reasonably foreseeable cumulative effects to ESA-listed species, 
including CIBWs, from other activities are considered in the analyses 
conducted in the biological opinion per the ESA. The biological 
opinion, issued March 23, 2020 found NMFS' issuance of the IHAs to POA 
would not jeopardize the continued existence of CIBWs or destroy or 
adversely modify their critical habitat. For these reasons, we have not 
implemented the Commission's recommendation to cap the number of 
authorized takes of CIBWs across all activities for which take is 
requested.
    Comment 3: The Commission recommends that, until such time that POA 
conducts hydroacoustic monitoring to confirm the extents of the Level A 
and B harassment zones, NMFS (1) use 1,174 m rather than 629 m for the 
Level B harassment zone during attenuated impact pile driving of 48-in 
piles and 3,502 rather than 2,247 m during attenuated vibratory pile 
driving of 48-in piles based on the extents of the Level B harassment 
zones presented in Tables 12 and 13, respectively, of Austin et al. 
(2016), (2) re-estimate the Level A harassment zones during attenuated 
impact installation of 48-in piles based on the attenuated source level 
of 190 dB re 1 [mu]Pa at 10 m and 15 log R and during attenuated 
vibratory installation of 48-in piles based on the attenuated source 
level of 159.5 dB re 1 [mu]Pa at 10 m and 14.67 log R, and (3) re-
estimate the Level A and B harassment zones during attenuated impact 
and vibratory impact installation of 24-, 36-, and 144-in piles based 
on the unattenuated source levels in Table 2 and 6 of the Federal 
Register notice, if it intends to use the unattenuated propagation loss 
factors presented in the notice.
    Response: Austin et al. (2016, Table 12) provided estimated median 
ranges to the 160 dB rms isopleth during installation of 48-in piles 
using a bubble curtain by applying best-fit transmission loss (TL) 
coefficients. It is important to note these distances were modeled from 
data collected at 10 m and 1,000 m and were not measured at exactly 
those locations. The estimated median distances to the 160 dB isopleth 
(which NMFS uses as a Level B harassment threshold for impact pile 
driving) for four piles ranged from 578 m to 1100 m for an average 
median distance of 824 m. The notice of proposed IHAs used an approach 
that estimated the distance to the 160 dB isopleth at 629 m as a result 
of applying unattenuated source levels with an assumed effective 
attenuation of 7 dB due to use of an unconfined bubble curtain. Since 
issuance of the notice of proposed IHAs, the POA is now going to deploy 
a confined bubble curtain (as described above) on all piles in water 
depths suitable for a bubble curtain in Phase 1 which is expected to 
further increase sound attenuation. The casing sleeve pile is a solid 
steel pile with interior cushions or air pockets. This sleeve surrounds 
the bubble curtain and will be embedded in sediment several feet. This 
design is anticipated to further reduce both water and sediment-born 
sound propagation into the marine environment. Despite use of this 
system, we agree with the Commission that using the bubble curtain pile 
data is more appropriate to estimate the initial distances to 
harassment isopleths (which will then be verified in situ). However, in 
lieu of the Commission's recommended approach of using a practical 
spreading loss model to a lower source level, we have relied on the 
data directly presented in Austin et al. (2016) and have therefore 
adjusted the Level B harassment zone for 48-in piles to 824 m during 
impact pile driving.
    For vibratory driving and removal, we have determined that 
adjustments at this stage are not necessary. Blackwell (2005) reported 
a drop-off rate of 22 dB to 29 dB per doubling of distance for 
vibratory pile driving. URS (2007) applied a 25 dB drop-off to 
vibratory sheet pile driving at the POA for a distance to the 120dB 
isopleth of 800 m. The source levels for driving 24-in and 36-in piles 
are estimated to be similar as those measured during sheet pile driving 
(154-171 dB for the PCT vs 168 dB during sheet pile driving). While we 
have applied a 122.2 dB Level B harassment threshold, our estimated 
distances using the approach in the notice of proposed IHAs exceeds 
those estimated during sheet pile installation. The Level B harassment 
isopleths estimated for vibratory driving 24 to 48-in piles with 
similar source levels as the sheet pile project far exceed 800 m (846-
2,247m). The distance to Level B harassment isopleth for vibratory 
driving 144-in piles is over 9 kms. No changes are necessary for 144-in 
piles since not only will there be minimal use of the vibratory hammer 
(one pile), in situ acoustic data from Phase 1 will be used to estimate 
transmission loss rates, assisting in the verification of analysis for 
Phase 2. Therefore, we find no adjustments the Level B harassment zone 
during vibratory driving are necessary at this time.
    For similar reasons, it is also not necessary to recalculate Level 
A harassment zones. The Commission is correct that the median source 
level for impact hammer is 190 dB; however, this is a sound pressure 
level (SPL) of 190 dB rms (Table 16 in Austin et al. 2016). For Level A 
harassment calculations we apply sound exposure levels (SEL) values. In 
our analysis, the estimated sound pressure level (SPL) is 193 dB rms 
and 180 dB SEL. To be conservative, we maintain the higher source level 
than that recommended by the Commission. Again, during Phase 1, the 
bubble curtain will be encased by a casing pile, further attenuating 
noise. The acoustic monitoring plan is designed to measure both source 
levels (near-field) and far field received levels; therefore, zones can 
be adjusted accordingly. Finally, the Level A zones represent the 
distance at which an animal would have to remain during the duration of 
driving or removing the number of piles considered in the analysis. 
This is already a conservative approach and for the reasons listed 
above, there is no need to adjust Level A harassment zones.

[[Page 19302]]

    More important than estimating harassment zones is the fact that 
these zones (which, for CIBWs, equate to shutdown zones) may very well 
be adjusted at the onset of pile driving once the initial interim 
acoustic monitoring report is reviewed by NMFS. Again, harassment zones 
do not influence take numbers for any marine mammal species; therefore, 
the number of takes estimated or authorized would not change. There are 
multiple ways to model noise levels (as demonstrated by the various 
approaches from the POA, the Commission, and NMFS' approach) with no 
single method necessarily being more accurate than others, especially 
given the complex acoustic environment in Knik Arm. While data to date 
demonstrate our acoustic analysis provides an adequate and realistic 
estimate, a major goal in the hydroacoustic monitoring plan is to 
refine these zones as soon as possible with real data. The Commission 
agrees with us on this when they state elsewhere in their letter that 
the extents of the larger Level A harassment zones and the Level B 
harassment zones are best measured in-situ. As was described in the 
notice of proposed IHAs, POA will begin conducting acoustic monitoring 
at the onset of pile driving (in April when beluga whale presence is 
scarce) and will provide an interim report to NMFS within 10 days for 
24 to 48-in piles and 72 hours for 144-in piles. The hydroacoustic 
monitoring plan made available for public comment in association with 
the notice of proposed IHAs indicated that measurements would be taken 
at various distances representing both near-field source levels and 
far-field received levels. These far-field distances ranged from 300m-1 
km (where the majority of impact pile driving harassment isopleths have 
been estimated) and 3km+. Therefore, distances to the Level B 
harassment isopleth will indeed be identified. Therefore, while we 
appreciate the Commission's recommendations, at this time we find our 
acoustic analysis is appropriate with the exception of slight 
adjustments to the 48-in pile Level B harassment zone. NMFS will adjust 
all Level A harassment and Level B harassment isopleths, if 
appropriate, based on the new, more relevant hydroacoustic data 
collected as POA installs piles with a confined bubble curtain. For 
Phase 2, it is still currently unknown if a confined or unconfined 
bubble curtain will be used. Because our analysis reflects previously 
collected data, we do not find any adjustments to Phase 2 zones are 
necessary at this time. Again, the POA will conduct hydroacoustic 
monitoring at the onset of pile driving during both Phase 1 and Phase 2 
and Level A harassment and Level B harassment isopleths will be refined 
with in situ data. Finally, any adjustments to the harassment zones do 
not change any take numbers for any marine mammal species as take 
estimates are not based on the size of the harassment zones (e.g., CIBW 
takes are based on sighting rates (whale per hour) throughout Knik Arm 
and other species take estimates are based on presence/absence 
regardless of zone size).
    Comment 4: The Commission recommends that NMFS refrain from using 
the 7-dB source level reduction in these authorizations and all future 
proposed incidental take authorizations, and recommends that NMFS 
consult with the relevant experts regarding the appropriate source 
level reduction factor to use to minimize far-field effects on marine 
mammals for all relevant incidental take authorizations and, until the 
experts have been consulted, refrain from using a source level 
reduction factor when bubble curtains are to be implemented.
    Response: The use of a confined bubble curtain provides further 
justification for use of the 7dB reduction to source levels as proposed 
in the notice of proposed IHAs. Not only will the bubbles be confined 
but the pile will be set several feet into the substrate. In its 
comments, the Commission asserted that the bubble curtain deployed 
during the 2016 TPP project was not effective. However, the bubble 
curtain resulted in reduced source levels during testing of the TPP 
(see Table 12 in Austin et al. 2016). For example, the POA measured 
source levels during installation of 48-in piles that were unattenuated 
and were installed with bubble curtains; source levels were 
consistently equal to or greater than 7-dB less when bubble curtains 
were applied with the exception of one pile where the bubble curtain 
was turned on and off (versus comparing piles with and without bubble 
curtains).
    Overall, the Commission has made this comment on previous IHAs and 
NMFS has responded accordingly. For example, we refer the reader to our 
previous, more general response in our notice of issuance of a previous 
IHA (84 FR 64483, November 29, 2019). Finally, as described above, in 
situ measurements will be taken upon the onset of pile driving and 
harassment zones will be adjusted accordingly. At this time, the 
existing data support the accuracy of our analysis.
    Comment 5: The Commission recommends that in the Federal Register 
notice for POA's authorizations, if issued, and the final 
authorizations, NMFS: (1) (a) Fix select issues regarding 
inconsistencies and errors in Tables 1-2, 2, 6, 7, and 8 of the Federal 
Register notice for unattenuated and attenuated vibratory installation 
of 24-in piles, unattenuated impact installation of 24-in piles, and 
attenuated vibratory installation of 48-in piles, and (b) ensure that 
all of the Level A and B harassment zones, along with the shut-down and 
monitoring zones, are correct based on all the various assumptions; and 
(2) use 209.5 rather than 202 dB re 1 [mu]Pa at 10 m as the assumed 
source level for attenuated impact installation of 144-in piles and 
increase the Level B harassment zone from 1,945 to 4,984 m.
    Response: NMFS has clarified Table 7 to reflect Table 1-2. Despite 
multiple hammers working at once, no more than the number of piles 
represented in Table 7 would be installed on any given day. The maximum 
amount of piles installed on any given day is four. We have also 
updated the amount of time of vibratory driving per pile to reflect the 
maximum amount of time estimated by the POA (i.e., 75 minutes instead 
of the 100 minutes in the notice of proposed IHAs). We note that these 
minor changes are insignificant in that all vibratory driving results 
in very small harassment zones for all hearing groups and all are less 
than the 100 m shutdown requirement.
    NMFS notes the other items that the Commission asserts to be errors 
or inconsistencies are actually correct and no adjustments are 
necessary. The Commission noted differences between Tables 1-2 and 7 
for the amount of 48-in piles driven by a vibratory hammer in one day 
(one pile versus the 1-3 piles for impact hammering) and claims we have 
thus underestimated noise levels. However, the Commission mistakenly 
assumed equal distribution between impact and vibratory pile driving 
48-in piles. As noted in the POA's application and NMFS' notice of 
proposed IHAs, the POA anticipates using the vibratory hammer sparingly 
during installation of permanent piles. That is, the one to three 48-in 
piles per day installed with an impact hammer reflected in Table 1-2 
and one pile per day for vibratory installation in Table 7 are both 
correct. Hence, the resulting Level A harassment isopleths (Table 8) 
are also correct. In addition, all 24-in piles except six in Phase 2 
will be driven using the bubble curtain.
    As for the assumed source level and estimated Level B harassment 
distance

[[Page 19303]]

for impact driving 144-in piles, NMFS' original analysis is accurate. 
The Commission suggests we should use an unattenuated source level to 
estimate distance to the Level B harassment zone. However, the 144-in 
piles would be installed using a bubble curtain and, therefore, we 
disagree with the Commission that the unattenuated source level is 
appropriate. Regarding what the starting source level should be, we 
find the Commission's concern regarding a 0.5 dB difference in source 
level is non-substantive when considering source variability and model 
regressions. Further, the first installation of a 144-in pile will be 
accompanied by acoustic monitoring in both the near and far-field. An 
interim report will be sent to NMFS within 72 hours and zones will be 
adjusted accordingly, if warranted. Again, we note the amount of take 
and pre-pile driving clearance zones are unaffected by any changes 
recommended by the Commission.
    NMFS acknowledges a typographical error in Table 7 that indicates 
the source levels for 48-in piles is 171 dB rms when it should reflect 
161 dB rms, as correctly indicated elsewhere in the notice of proposed 
IHAs (and as provided in the POA's application and Austin et al. 2016). 
We have also corrected Table 6 and 7 to reflect that only up to 4 24-in 
piles could be driven on any given day. We note these differences 
result in minor differences in Level A harassment zones and the 100 m 
shutdown zone remains appropriate.
    Comment 6: The Commission recommends that NMFS continue to make the 
24-hour Level A harassment approach a priority to resolve in the near 
future and consider incorporating animat modeling into its user 
spreadsheet.
    Response: NMFS has previously informed the Commission of its 
efforts to develop a method for more accurately assessing the potential 
for Level A harassment from acoustic sources such as pile driving. NMFS 
is continuing that effort.
    Comment 7: The Commission agrees that NMFS's assumption to reduce 
the number of takes based on the maximum percentage of beluga whales 
previously taken at the POA is justifiable, but questions the 
underlying take estimates. The Commission recommends that NMFS revise 
its take estimates based on the maximum density estimate in the project 
area of 0.236 whales/km\2\ from Goetz et al. (2012), the revised 
ensonified areas based on the Commission's recommendations herein, the 
numbers of days of the various activities from Table 6-2 in POA's 
application, and an assumed maximum take rate of 59 percent based on 
Table 10 of the notice of proposed IHAs. If the number of revised 
beluga whale takes during either Phase 1 or 2 exceeds NMFS's assumed 
one third of the population estimate (83 FR 63376), the Commission 
recommends that NMFS deny the authorization(s) outright.
    Response: NMFS provided its rationale in the notice of proposed 
IHAs for why the Goetz et al. (2012) data was not applied to estimate 
CIBW take, and that rationale remains appropriate. We do not agree our 
method underestimates take and are confident it more accurately 
reflects expected take than the Commission's approach. The Commission 
asserts NMFS used sightings rates that have no spatial dimension and 
are not applicable for species that routinely occur in the project area 
and for activities with larger ensonified areas than were observed 
during POA's 2016 monitoring efforts. We strongly disagree. The 
sighting rate of CIBWs is derived from scientific monitoring spanning 
several years (Kendell and Cornick 2015). The data set covers all 
months the POA would be conducting pile driving over several years and 
is based on all animals observed during scientific monitoring 
regardless of distance (the authors did not report sighting distances 
but were equipped with 7 x 50 binoculars and theodolites). Therefore, 
the take calculation inherently assumes any CIBW within lower Knik Arm 
could be taken during pile driving. This will not be the case, given 
the impact pile driving harassment zones are much smaller than the 
width of Knik Arm. As described previously and in our notice of 
proposed IHAs, harassment areas are not used to estimate take for any 
marine mammal species for this project. More importantly, the 
Commission fails to recognize the mitigation measures prescribed by 
NMFS are more stringent than those in any previous incidental take 
authorization issued to the POA and are designed to avoid all take of 
CIBWs. However, we have authorized some take as a precaution. The 
amount of take authorized in each IHA is no more than 20 percent of the 
population. In summary, the Commission does not provide sufficient 
reason why using a single density estimate from June aerial surveys is 
more accurate than using several years of scientific monitoring data, 
spanning all months in which the POA would be working, and which 
considers all whales observed. We have maintained both our CIBW take 
method and take amount in the final IHAs.
    Comment 8: The Commission recommends that NMFS increase the numbers 
of total harbor seal takes from 1,016 to at least 1,566 takes during 
Phase 1 and from 600 to at least 999 takes during Phase 2, if NMFS does 
not revise the extent of the Level B harassment zone for vibratory 
installation of 144-in piles based on the Commission's recommendation, 
or to at least 1,863 seals if it does. They then recommended NMFS 
reduce the total Level B harassment takes in Phase 1 and 2 by 30 
percent to account for Level A harassment takes.
    Response: First, we note the POA allows for the installation of 
only one of the nine 144-in piles by vibratory pile driving; therefore, 
this activity is extremely limited in time. NMFS agrees with the 
Commission that the maximum number of harbor seals on any given day 
observed during the TPP was 9 seals. The Commission assumes equal 
abundance at greater distances and suggests we double that number when 
vibratory pile driving Level B harassment zones extend beyond 2km 
(since all harbor seal sightings were within 2kms, likely due to 
sightability). We believe the Commission's approach is overly 
conservative as it uses maximum abundance throughout the construction 
season despite data indicating no harbor seals were observed from 
August through November 2005-2007. More importantly, it does not 
consider that over 8 years of data spanning April through November, a 
maximum of 57 total harbor seals (range 0-57) were observed in any 
given year and that both scientific and construction monitoring 
typically covered the entire construction season. For example, in 2009, 
construction monitoring efforts spanned 209 days from March through 
December and over 3,322 hours. During that time, only 34 harbor seals 
were observed. Therefore, the Commission's suggestion that 1,016 harbor 
seal takes in Phase 1 and 600 harbor seal takes in Phase 2 is not 
adequate is not justified by the years of previous monitoring data. For 
these reasons, we maintain our original harbor seal take estimates and 
have authorized those takes.
    Comment 9: The Commission recommends that NMFS re-estimate the 
numbers of Level A and B harassment takes for harbor porpoises and 
humpback whales based on 50 percent of the takes being Level A 
harassment, which would result in 32 Level A harassment and 32 Level B 
harassment takes of harbor porpoises and 4 Level A harassment and 4 
Level B harassment takes of humpback whales.

[[Page 19304]]

    Response: Similar to the harbor seal take recommendation, the 
Commission fails to consider observation data and also does not 
consider context around the outputs of the user spreadsheet. Humpback 
whales and harbor porpoise are rarely observed in upper Cook Inlet and 
are not expected to remain for any meaningful duration. Therefore, we 
maintain that the estimates of Level A harassment and Level B 
harassment takes in our notice of the proposed IHAs are accurate 
representations of the likely potential occurrences of Level A 
harassment and Level B harassment.
    Comment 10: The Commission recommends that in the Federal Register 
notice for POA's authorizations, if issued, and the final 
authorizations, NMFS: (1) Specify a clearance time of 30 rather than 15 
minutes for beluga whales; (2) specify that delay procedures must be 
implemented if a beluga whale is observed (a)(i) within 1 km of the 
mouth of Knik Arm to the south and Green Lake Creek to the north during 
all activities except vibratory installation and removal of 144-in 
piles and (ii) within 2 km of the mouth of Knik Arm to the south and 
Mule Creek to the north during vibratory installation and removal of 
144-in piles and (b) activities cannot commence until the whale has 
moved at least 100 m beyond the Level B harassment zone and is 
transiting away from the zone; (3) include the measures for bubble 
curtain performance standards; (4) include the requirement that pile 
driving and removal can occur only during daylight hours; (5) specify 
the number of each pile size and installation method that would be 
monitored acoustically; (6) include the requirement that POA must 
include in the draft and final hydroacoustic monitoring reports the (a) 
substrate type(s), (b) number of strikes per pile or strikes per day 
and pulse durations associated with impact pile driving, (c) spectra 
for all pile sizes, installation methods, and with and without the 
bubble curtain, and (d) amount of time the bubble curtain was turned on 
and off; (7) include the requirements for POA to extrapolate Level A 
and B harassment takes to the unobserved portions of the Level A and B 
harassment zones and to include the raw PSO sightings datasheets in the 
draft and final marine mammal monitoring reports; and (8) require POA 
to alert NMFS when the total number of takes, including observed and 
extrapolated takes, for any species reaches 80 percent of those 
authorized per year.
    Response: NMFS has reviewed the Commission's specific suggestions. 
First, we note, as described above, the bubble curtain will not be 
turned on and off; therefore, those comments do not apply. We address 
the other recommendations in order: (1) The clearance time is 30 
minutes; (2) NMFS has delineated both inbound and outbound clearance 
zones (see Figure 1 in the IHAs) and included the Commission's 
recommended language that activities cannot commence until the whale 
has moved at least 100 m beyond the Level B harassment zone and is 
moving away from the zone; (3) the confined and unconfined bubble 
curtain measures, which are included in in the IHAs, reflect those 
previously established by the USFWS and NMFS; (4) as described in POA's 
application and notice of proposed IHAs, the IHAs now specifically 
include the measure that pile driving may only be conducted during 
daylight hours; (5 and 6) the hydroacoustic monitoring plan identifies 
the number of piles to be monitored while the IHAs contain specific 
reporting requirements including strikes per pile, pulse duration, and 
spectra; (7) the requirements to report extrapolated takes was 
contained within the proposed IHAs and NMFS has added the requirement 
that POA must submit data sheets; and (8) because pile driving cannot 
be conducted if the Level B harassment zone is not visible, then the 
need to extrapolate takes is not applicable to Phase 1. In Phase 2, 
vibratory driving of 144-in piles would only occur if impact driving is 
not successful (which is conservatively estimated for one of the nine 
piles). In such case, the POA would extrapolate takes of marine mammals 
for the portion of Level B harassment zone that is not able to be 
observed. The requirement for reporting to NMFS when 80 percent of CIBW 
take was reached was contained within the notice of proposed IHAs and 
the draft IHAs and we maintain that measure for the final IHAs. The 
Commission suggested this should be applied to all marine mammals, 
without providing justification. The only other marine mammal species 
with some reasonable level of occurrence is the harbor seal. NMFS has 
conservatively authorized take for this species that is 10 to 17 times 
the amount of take expected based on previous monitoring data. NMFS 
does not adopt the recommendation to require the POA report to NMFS 
when takes are 80 percent of all marine mammals.
    Comment 11: The Commission recommends that NMFS remove measure 4(g) 
from the 2020 final authorization and include the Level A harassment 
zones in both final authorizations.
    Response: NMFS concurs and has adopted the recommendations.
    Comment 12: The Commission recommends that NMFS include in the 
final authorizations a requirement that POA provide the Level A and B 
harassment zones measured in-situ for each pile size rather than just 
the source levels and if the Level A or B harassment zones exceed those 
included in the final authorization, either (1) increase the Level A 
and B harassment zones accordingly or (2) require POA to implement an 
additional sound attenuation device and verify that the resulting Level 
A and B harassment zones are equal to or less than those included in 
the final authorization.
    Response: The hydroacoustic monitoring plan is designed to more 
accurately verify harassment zones. We have included a requirement in 
the IHAs to report estimated harassment zones based on acoustic 
measurements. Condition 4(f) of the draft IHAs indicated NMFS may 
adjust the zones accordingly. While the Commission's comment only 
addressed whether the zones are larger than expected, it is also 
possible that the zones will in fact be smaller, especially in light of 
the application of a confined bubble curtain. In the unlikely case the 
zones are larger than estimated, NMFS will not require additional noise 
attenuation, but instead will adjust shutdown and monitoring zones 
accordingly.
    Comment 13: The Commission recommends that NMFS ensure that POA (1) 
is aware that the number of piles of each pile size that are to be 
monitored must actually be driven to depth and sound levels associated 
with piles installed at a level of refusal are not appropriate and do 
not count toward the numbers of piles to be monitored and (2) conducts 
measurements during the installation of the entire pile rather than 
just a portion of the installation (e.g., 5 of 60 minutes).
    Response: The POA has submitted an updated hydroacoustic monitoring 
plan based on both comments from the public and NMFS' acoustic experts. 
Nowhere in the POA's original plan did it indicate noise levels only 
associated with the level of refusal would be used or that measurements 
would only be made for 5 of 60 minutes. Regardless, the POA has 
clarified in its updated plan that measurements will be made during the 
entirety of pile driving any given pile.
    Comment 14: The Commission commented that if POA intends to 
determine the effectiveness of the bubble curtain (or other sound

[[Page 19305]]

attenuation device), the Commission recommends that NMFS advise POA to 
(1) conduct measurements during vibratory installation of two 24- and 
two 36-in piles and impact installation of two 48-in piles and two 144-
in piles with and without the bubble curtain, (2) alternate whether the 
bubble curtain is on or off when pile driving begins for each pile 
size, if POA still plans to turn the bubble curtain on and off for the 
same pile, and (3) ensure that the bubbles are dissipated fully before 
making measurements with the bubble curtain turned off.
    Response: The purpose of testing effectiveness of a bubble curtain 
would be to determine how much noise reduction the bubble curtain is 
achieving. Data such as these can help inform future management 
actions. However, NMFS believes that testing the effectiveness of the 
bubble curtain by either turning it on or off or installing piles 
without a bubble curtain is not warranted and would result in 
unnecessarily high noise levels, further disturbing marine mammals. We 
note that during Phase 1, the bubble curtain would be confined and NMFS 
is also not requiring the POA to test the effectiveness of this design. 
The POA will; however, conduct both sound source verification 
measurements (approximately 10 m from the pile) and far-field acoustic 
measurements to determine what the actual noise levels generated from 
the activity will be. The acoustic monitoring data will verify if the 
actual source levels and received levels are within the bounds 
estimated in our analysis. Therefore, we find the Commission's 
experimental design of installing piles with and without bubble 
curtains is not warranted and could result in greater impacts to marine 
mammals.
    Comment 15: The Commission recommends that NMFS refrain from 
issuing renewals for any authorization and instead use its abbreviated 
Federal Register notice process. The Commission recommends that NMFS 
ensure that the current renewal terms and conditions are included in 
section 8(a) of the final authorization, if issued and notwithstanding 
the Commission's recommendation to refrain from issuing renewals. The 
Commission further suggested that if NMFS chooses to continue proposing 
to issue renewals, the Commission recommends that it (1) stipulate that 
a renewal is a one-time opportunity (a) in all Federal Register notices 
requesting comments on the possibility of a renewal, (b) on its web 
page detailing the renewal process, and (c) in all draft and final 
authorizations that include a term and condition for a renewal and, (2) 
if NMFS refuses to stipulate a renewal being a one-time opportunity, 
justify why it will not do so in its Federal Register notices, on its 
web page, and in all draft and final authorizations.
    Response: NMFS does not agree with the Commission and, therefore, 
does not adopt the Commission's recommendation. NMFS will provide a 
detailed explanation to the Commission of its decision within 120 days, 
as required by section 202(d) of the MMPA.
    Comment 16: The Commission recommends that NMFS either make its 
determinations regarding negligible impact, small numbers, and 
unmitigable adverse impact on subsistence use based on the total number 
and type of taking for each species or stock for both authorizations 
combined or delay the Phase 2 activities until 2022 if a renewal 
authorization is issued for the Phase 1 activities.
    Response: The MMPA is clear that NMFS shall authorize, for periods 
of not more than 1 year, the incidental taking, by harassment, of small 
numbers of marine mammals if we find that such harassment during that 
period concerned will have a negligible impact on such species or stock 
and will not have an unmitigable adverse impact on the availability of 
such species or stock, and the authorization for such activity shall 
prescribe certain methods and measures.
    The POA has indicated to NMFS it is confident that all Phase 1 work 
will be completed in 2020. If the POA requests a renewal, NMFS will 
consider all relevant criteria and data collected during 2020 to assess 
if the renewal is appropriate. We may also modify, suspend, or withdraw 
any IHA if the holder fails to abide by the conditions prescribed in 
the IHA, or if NMFS determines the authorized taking is having more 
than a negligible impact on the species or stock of affected marine 
mammals (see condition 7 of the IHAs). In any case, should the POA 
request a renewal of the Phase 1 IHA (again, they have indicated this 
is unlikely), we will consider our established criteria for issuing a 
renewal, all data collected, and the potential impacts (both beneficial 
and adverse) to determine if a renewal is appropriate. Further, we note 
the Biological Opinion associated with this action limits the amount of 
take, as defined under the ESA, of CIBWs in any given year to 55 take 
incidents; therefore, the POA is constrained by this evaluation.
    Finally, the Commission asserts that neither a negligible impact 
nor a small number determination may be able to be made on the 
authorizations separately, let alone combined. We disagree with the 
former as we have fully explained our rationale for making both the 
negligible impact and small numbers findings for each IHA. We have 
prescribed mitigation and monitoring measures that are the most 
restrictive of any pile driving IHA issued, as required in this case to 
meet the MMPA's least practicable adverse impact standard. We have both 
reduced the amount of noise entering the marine environment (i.e., 
requiring the POA to use a confined bubble curtain) and reduced the 
risk of CIBWs being exposed to any noise that may cause harassment 
(again, the takes authorized are provided for circumstances where a 
whale enters the harassment zone before pile driving can be shut down). 
With respect to implementation of the MMPA, the Commission makes an 
accusation that our process of issuing two successive IHAs is a ``a way 
to subvert the authorization process under 101(a)(5)(D) of the MMPA and 
authorize the taking under two separate authorizations that could not 
be issued under a single authorization.'' This is an incorrect 
assessment of NMFS' motives for using this approach.
    The MMPA clearly states an IHA may not exceed one year. The 
issuance of successive IHAs allows us to evaluate the project in its 
entirety and ensure approaches to marine mammal conservation (e.g., 
mitigation and monitoring measures) are consistent across years, while 
also allowing for some administrative streamlining, which provides 
efficient processing of IHAs, allowing resources to be focused on 
marine mammal conservation and protection. Should any information be 
identified in Phase 1 that suggests our analysis should be updated, we 
have both the authority and responsibility to ensure the required 
findings continue to be met or, as described in condition 7 of the 
IHAs, we may modify, revoke, or suspend the IHAs. We do note; however, 
that even if we did consider the total amount of CIBW take over 2 years 
(n = 90), this is 32.2 percent of the population (279 whales) (if 
assumed that each incident occurs to a unique individual). Earlier in 
its letter (see Comment 7), the Commission stated ``If the number of 
revised beluga whale takes during either Phase I or II exceeds NMFS's 
assumed one third [33%] of the population estimate (83 FR 63376) of 
327, the Commission recommends that NMFS deny the authorization(s) 
outright.'' In summary, NMFS has made our findings relative to each 
IHA; however, our issuance of two successive

[[Page 19306]]

IHAs is both more efficient, effective, and provides consistent 
conservation value to the species than if we would have received an 
application for an IHA from the POA in late 2020 for work in 2021.
    Comment 17. The Commission recommends that NMFS (1) consult with 
POA regarding the numerous issues raised in the Commission's letter and 
direct the applicant to revise the application accordingly and (2) 
publish revised proposed authorizations prior to issuance of any final 
authorization or authorizations.
    Response: What the Commission claims are ``numerous omissions, 
inconsistencies, ambiguities, and incorrect information and assumptions 
identified'' are, for the most part, differences of opinion on how 
available data should be applied to our analysis and, in each case, we 
have presented reasons why we disagree with specific recommendations. 
If we did agree that there actually was an error (e.g., listing 171 dB 
in Table 7 instead of 161 dB) or the Commission's logic is more 
appropriate to implement (e.g., use 48-in bubble curtain data to 
establish initial Level B harassment zones), we have made the 
recommended changes. We note many of the recommendations by the 
Commission are detail-oriented and, in NMFS' view, do not provide 
additional conservation value. NMFS disagrees that the information 
presented in association with the proposed IHAs was insufficient to 
facilitate public review and comment, as the Commission implies. 
Further, in the notice of proposed IHAs, NMFS clearly identified where 
we did not agree with the POA's analysis in their application and 
presented alternative approaches which better reflect the best 
available science. Following receipt of an adequate and complete 
application, it would be inappropriate for NMFS to demand further 
revised versions of the application to reflect NMFS' own analysis or 
additional mitigation prescriptions beyond those that the applicant 
proposes.
    Finally, NMFS has been in constant coordination with the POA to 
improve upon both the noise attenuation devices and marine mammal and 
acoustic monitoring plans throughout the IHA process in an effort to 
minimize impacts of the project on CIBWs to meet MMPA mandates. This 
notice of issuance describes the benefits realized from those 
communications and clearly identifies any changes from the proposed 
IHAs phase. Overall, there are no substantial changes or new 
information that would lead us to reach any other conclusions regarding 
the impact to marine mammals. In fact, the addition of a confined 
bubble curtain and implementation of a fourth monitoring station only 
strengthens our findings regarding negligible impact and unmitigable 
adverse impact on subsistence use. For these reasons, NMFS is not 
republishing a notice of proposed IHAs.
    Comment 18: The CBD asserts that NMFS's negligible impact 
determination is arbitrary and capricious and that the specified 
activities would have greater than a negligble impact on CIBWs. The CBD 
suggest (1) NMFS underestimated the impacts of pile driving on CIBWs, 
(2) there were flaws in take estimate methodology, (3) NMFS should 
apply the 120dB threshold to all noise sources, (3) the proposed 
project does not avoid or impose any specific mitigation, (4) NMFS only 
counts one take exposure per day, but the animals may be exposed as 
they travel in and out of Knik Arm, (5) in-air noise impacts to seals 
and sea lions were not addressed and (6) the conclusion that there is 
no harassment or ship strike potential from vessels is wrong.
    Response: For clarity, NMFS' authorization does not ``approve 
activities''; that permitting responsibility lies with the U.S. Army 
Corps of Engineers. As described above in response to comments from the 
Commission, NMFS has not underestimated the impacts of pile driving on 
marine mammals, there are no flaws in the take estimate methodology, 
and the IHAs indeed provide extensive mitigation (and is actually some 
of the most stringent mitigation in any pile driving-related IHA). We 
do not repeat our reasons why we disagree with CBD here but refer the 
reader to the relevant responses to the Commission.
    We do note CBD appears to have misunderstood the monitoring data 
when suggesting that 59 percent of takes only occurred in July. In 
fact, this amount was derived from monitoring occurring from March 
through December 2009 (20 takes total out of the 34 allocated); the 
same time over which the POA would be conducting the POA project. It is 
unclear why CBD suggests monitoring only occurred in July- this is 
inaccurate and all the monitoring reports were made available on our 
website during the public comment period. In addition, group size 
(n=11) was not actually a factor in our final take estimates but a 
means by which to determine if the total take authorized would allow 
for the take of larger group sizes. This was fully described in the 
notice of proposed IHAs but we recognize the draft EA was not updated 
to reflect this approach. We have since updated the EA to clarify group 
size was not ultimately used as a correction factor or in take 
calculations. The CBD also claims we entirely discounted the estimated 
take but this is also not accurate. We applied a 59 percent correction 
factor to the calculated take to account for the extensive mitigation 
measures we prescribe in the IHAs and to reflect the monitoring data.
    CBD believes we should apply a 120 dB threshold for Level B 
harassment based on beluga hearing sensitivity. We disagree. First, any 
dB-based threshold itself is a step-function approach (i.e., animals 
exposed to received levels above the threshold are considered to be 
``taken'' and those exposed to levels below the threshold are not); 
but, in reality, it is in fact intended as a sort of mid-point of 
likely behavioral responses (which are extremely complex depending on 
many factors including species, noise source, individual experience, 
and behavioral context). What this means is that, conceptually, the 
function recognizes that some animals exposed to levels below the 
threshold will in fact react in ways that are appropriately considered 
take, while others that are exposed to levels above the threshold will 
not. Use of a specific dB threshold allows for a simplistic 
quantitative estimate of take, while we can qualitatively address the 
variation in responses across different received levels in our 
discussion and analysis.
    To establish the appropriate Level B harassment threshold in a 
noisy environment such as upper Cook Inlet, NMFS reviewed data recently 
collected at the POA. During the 2016 TPP project, the POA conducted 
``ambient'' acoustic monitoring, in accordance with accepted 
methodology for characterizing ambient noise levels. Ambient noise 
levels (in the absence of pile driving) were 122.2 dB. We described 
this analysis in our notice of proposed IHAs. Therefore, it is 
reasonable to establish a 122.2 dB Level B harassment threshold at the 
POA.
    With respect to exposures, nowhere does NMFS indicate that an 
individual whale could not be exposed upon entering and exiting Knik 
Arm on a given day. Our take estimates are based on sighting rates 
regardless of direction or if the whales observed were previously 
observed that day. Further, the POA would document take for any whale 
entering the Level B harassment zone as it is nearly impossible to 
distinguish individuals in the field. Finally, our small numbers 
determination is based on an assumption that the take estimate 
represents number of individuals, rather

[[Page 19307]]

than instances, which is a conservative assumption. Further, we re-
iterate information on page 72182 of our notice of proposed IHAs 
wherein we described that acoustic data indicate beluga whales move 
through lower Knik Arm relatively quickly, when entering or exiting the 
arm, and remain in the upper arm for several days, or weeks, before 
moving back out into Cook Inlet (Castellote et al., 2020). Satellite 
telemetry data indicate such a movement pattern may be common. 
Specifically, a beluga instrumented with a satellite link time/depth 
recorder entered Knik Arm on August 18th and remained in Eagle Bay 
until September 12th (Ferrero et al. 2000). Therefore, movement by any 
given whale in and out of Knik Arm on a single day is not a likely 
scenario.
    Comment 19: CBD postulates that NMFS' small numbers determination 
is invalid because the amount of take proposed to be authorized is 
greater than 10 percent of the CIBW population and that NMFS' 
definition of small numbers conflates this criterion with the 
negligible impact requirement. CBD claims the incidental harassment 
authorizations here violate the MMPA because it does not guarantee that 
only small numbers of CIBWs and the other marine mammals impacted by 
the Port of Alaska's activities will be taken.
    Response: CBD suggests that by defining small numbers to be 
relative to the overall population the criterion ends up being similar 
to the negligible impact finding and that Congress's intent was that 
the MMPA protect not only populations, but individual marine mammals. 
We disagree that small numbers is conflated with our negligible impact 
finding. While ``small numbers'' is simply a percent of the population, 
our negligible impact finding considers a number of parameters 
including, but not limited to, the nature of the activities (e.g., 
duration, sound source), effects/intensity of the taking, the context 
of takes, and mitigation.
    The reference to a ``court concluded'' take limit of 12 percent for 
small numbers likely comes from a 2003 district court opinion (Natural 
Resources Defense Council v. Evans, 279 F.Supp.2d 1129 (N.D. Cal. 
2003)). However, given the particular administrative record and 
circumstances in that case, including the fact that our small numbers 
finding for the challenged incidental take rule was based on an invalid 
regulatory definition of small numbers, we view the district court's 
opinion regarding 12 percent as dicta. Moreover, since that time the 
Ninth Circuit Court of Appeals has upheld a small numbers finding that 
was not based on a quantitative calculation (Center for Biological 
Diversity v. Salazar, 695 F.3d 893 (9th Cir. 1012)), and NMFS has more 
recently authorized take of up to one-third of a population abundance 
and considers this small.
    Comment 20: CBD suggests NMFS has failed to implement ``means of 
effecting the least practicable adverse impact'' on marine mammals. CBD 
asserts that NMFS relies on visual monitoring that is known to be 
ineffective and inadequate to protect marine mammals. CBD suggests 
lookouts are not as effective in mitigating acoustic impacts as time-
area restrictions. They also suggest NMFS failed to consider many other 
mitigation measures to reduce the proposed activities' impacts to the 
least practicable level.
    Response: NMFS disagrees for several reasons. The POA has added a 
fourth monitoring station (at Ship Creek) since the notice of proposed 
IHAs were disseminated for review. At each station, there will be two 
PSOs on watch at any given time. Further, the PSO stations range from 
Point Woronzof to the most northern end of the port's property (just 
south of Cairn Point) allowing for broad coverage of the entirety of 
lower Knik Arm. This is the most extensive monitoring coverage at the 
POA to date and NMFS is confident that whales, if present, will be 
detected. Most of the Level B harassment zones are less than 1 km and 
the greatest, with the exception of the single 144-in pile that may be 
driven with a vibratory hammer, the Level B harassment zone is 
estimated to be approximately 2.2 kms. During the Hilcorp Cook Inlet 
Pipeline Project, marine mammal observers we able to easily observe 
CIBWs at this distance and had detections at greater than 8 kms 
(Sitkiewicz et al., 2018). Further, there are mitigation measures 
preventing pile driving from occurring if visibility in any portion of 
the Level B harassment area is obscured by weather or sea state. 
Therefore, we find the visual monitoring plan is an effective tool at 
detecting marine mammals, ensuring the mitigation measures are adhered 
to. These measures effect the least practicable adverse impact on 
marine mammals.
    CDB also suggests we failed to consider other mitigation measures. 
In the POA's application, they proposed a 100 m shutdown for all marine 
mammals, including CIBWs, and use of an unconfined bubble curtain. 
However, our IHAs require much more extensive mitigation. These 
measures include not starting pile driving if CIBWs are entering Knik 
Arm, shutting down pile driving if whales approach the Level B 
harassment zone (which is much greater than 100 m), not vibratory 
driving 144-in piles in August (a time-area restriction that the CBD 
claims we did not consider), and employing a confined bubble curtain/
casing pile noise attenuation system during Phase 1.
    Comment 21: CBD asserts that the proposed activities will have an 
unmitigable adverse impact on subsistence uses. CBD believes the 
proposed activities are stressors on beluga whales, which will 
contribute to their imperilment; therefore, any take of beluga whales 
has an adverse impact on their availability for subsistence use and 
must be fully mitigated. They also indicate the IHA should require 
consultation with Native Alaskan communities to ensure adequate 
mitigation for subsistence harvest for harbor seals and Steller sea 
lions and that NMFS must not allow unmitigable adverse impacts on 
subsistence use of marine mammal stocks.
    Response: NMFS agrees with CBD that the authorized taking of marine 
mammals may not have an unmitigable adverse impact on subsistence uses 
and we have ensured this is the case. In this case, NMFS has imposed a 
number of mitigation measures designed to limit the introduction of 
noise in the aquatic environment through use of noise attenuation 
devices (e.g., confined bubble curtain) and temporal restrictions 
(i.e., no vibratory pile driving 144-in piles during August) and, if 
marine mammals are present, reducing exposure to noise through pile 
driving shutdown and delay procedures.
    Further, the POA notified 14 tribes to the availability of the 
notice of proposed IHAs for public comment. No subsistence users 
submitted public comments to NMFS on the proposed IHAs. No tribes have 
indicated to NMFS concern about the proposed IHAs adversely impacting 
their subsistence use. NMFS is prescribing much more stringent 
mitigation and monitoring measures than proposed by the POA, which will 
reduce the potential impacts to marine mammals. We have found this 
taking would have a negligible impact on the population, meaning we do 
not anticipate there to be adverse impacts on the annual rates of 
recruitment or survival. Therefore, the taking would not impede 
recovery of CIBW for potential future subsistence use.
    Overall, there is little subsistence use of marine mammals near the 
project area and no tribes have alerted NMFS to any concern over the 
proposed IHAs. The explanation and support for our findings is 
described further in the Unmitigable Adverse Impact Determination 
section of this notice.

[[Page 19308]]

    Comment 22: CBD believes the draft Environmental Assessment fails 
to comply with the requirements of the National Environmental Policy 
Act. They stipulate the Draft EA fails to consider a reasonable range 
of alternatives, lacks a meaningful environmental and cumulative 
impacts analysis and that NMFS must prepare an EIS.
    Response: In accordance with the National Environmental Policy Act 
(NEPA) and the Council on Environmental Quality (CEQ) Regulations, NMFS 
is required to consider a reasonable range of alternatives to a 
Proposed Action, as well as a No Action Alternative. Reasonable 
alternatives are viable options for meeting the purpose and need for 
the proposed action. The evaluation of alternatives under NEPA assists 
NMFS with understanding, and as appropriate, minimizing impacts through 
an assessment of alternative ways to achieve the purpose and need for 
our Proposed Action. Reasonable alternatives are carried forward for 
detailed evaluation under NEPA while alternatives considered but 
determined not to meet the purpose and need are not carried forward. 
For the purposes of this EA, an alternative will only meet the purpose 
and need if it satisfies the requirements of Section 101(a)(5)(D) of 
the MMPA.
    In accordance with NOAA's implementing procedures, the Companion 
Manual (CM) for NAO 216-6A, Section 6.B.i, NMFS is defining the No 
Action alternative as not authorizing the requested incidental take of 
marine mammals under Section 101(a)(5)(D) of the MMPA. This is 
consistent with our statutory obligation under the MMPA to either: (1) 
Deny the requested authorization or (2) grant the requested 
authorization and prescribe mitigation, monitoring, and reporting 
requirements. The Preferred Alternative (i.e., issuance of the IHAs) 
includes mandatory mitigation, monitoring, and reporting requirements 
for POA to achieve the MMPA standard of effecting the least practicable 
adverse impact on each species or stock of marine mammal and their 
habitat, paying particular attention to rookeries, mating grounds, and 
other areas of similar significance. Since NMFS is required to 
prescribe mitigation to effect the least practicable adverse impact on 
marine mammals, mitigation that reduces noise impacts on marine mammals 
is inherently included in Alternative 2 (the proposed action) and is 
included as part of the analysis of alternative(s) in the Environmental 
Consequences chapter in the EA. NMFS described both the No Action 
Alternative and Preferred Alternative in the EA. We have also included 
an ``Alternatives Considered but Eliminated from Further 
Consideration'' section in the final EA that considered whether other 
alternatives could meet the purpose and need while supporting this 
applicant's proposal to construct a new PCT. There is no requirement 
under NEPA to consider more than two alternatives, or to consider 
alternatives that are substantially similar to other alternatives or 
which have substantially similar consequences. NMFS' range of 
alternatives is based on the proposed action and the purpose and need, 
which are linked to NMFS' authorities under the MMPA. For the purposes 
of analysis under NEPA in the EA, an alternative will only meet the 
purpose and need if it satisfies the requirements under section 
101(a)(5)(D) of the MMPA. Therefore, NMFS determined that, based on our 
authorities and criteria under the MMPA, which included criteria 
regarding mitigation measures, appropriate considerations were applied 
to identify which alternatives to carry forward for analysis.
    NMFS disagrees with CBD that our environmental impacts section is 
not sufficient. We described both the general effects to marine mammals 
from exposure to noise (e.g., pile driving) and scientific literature 
identifying responses of CIBWs to pile driving at the POA. We have 
updated both our analysis in this notice and the final EA with the best 
available science regarding the newly released technical report 
describing the status of the CIBW stock (Sheldon and Wade, 2019). In 
the final EA, we also reviewed potential direct, indirect, and 
cumulative impacts to protected species and their environment, 
associated with NMFS' proposed action and alternatives. While the draft 
EA did not identify specific human activities, such as the Hilcorp 
seismic survey that CBD noted, we did include a section on the effects 
of oil and gas development in Cook Inlet that includes seismic work; 
therefore, this survey was not discounted. In the final EA, we included 
specifics regarding the work in Cook Inlet for which we currently have 
ITA requests. Since the Draft EA was released, we have also learned of 
other activity the POA is planning on implementing as well as proposed 
plans by Alaska DOT in upper Cook Inlet. We have included those 
activities in the Cumulative Effects section of the final EA.
    CBD is correct that Federal agencies generally prepare an EIS for a 
major Federal action significantly affecting the quality of the human 
environment. While CBD acknowledges that significance is determined by 
considering the context and intensity of the action, and that intensity 
is evaluated by considering the ten factors listed in 40 CFR 
1508.27(b), CBD argues, that if any one of these factors is met, then 
the agency must prepare an EIS. CBD further argues that, ``the impacts 
on an endangered species like the environmentally and culturally 
significant Cook Inlet beluga and its designated critical habitat alone 
is enough to trigger the need to prepare an EIS.'' NMFS disagrees. The 
mere presence of one or more factors listed in 40 CFR 1508.27(b) does 
not necessarily trigger the requirement to prepare an EIS. These 
factors are specific to evaluating the intensity of potential impacts 
of an action. NMFS can prepare an EA so long as the record supports the 
conclusion that potential impacts are not ``significant'' for the 
purposes of NEPA. Based on the information presented in the application 
and NMFS' Policy and Procedures for Compliance with the National 
Environmental Policy Act and Related Authorities (Companion Manual (CM) 
for NAO 216-6A) (NOAA 2017), Sections 3 and 7, NMFS' determination to 
prepare an EA is appropriate and in compliance with NEPA and 40 CFR 
1501.3 and 40 CFR 1508.9.
    Comment 23: CBD states that NMFS must comply with the ESA but 
asserts that NMFS should not issue take authorization under the ESA 
because such taking would jeopardize the continued existence of CIBWs 
and adversely modify their critical habitat.
    Response: In our notice of proposed IHAs, NMFS indicated that we 
have requested section 7 consultation under the ESA. CBD indicates they 
believe the proposed taking would jeopardize the recovery and survival 
of CIBWs but did not further explain how they reached this conclusion. 
NMFS has fully complied with the ESA. NMFS Alaska Region issued a BiOp 
concluding that issuance of take, by harassment, of CIBW, humpback 
whales (Mexico Distinct Population Segment (DPS)) and Western DPS 
(wDPS) of Steller sea lions would not jeopardize the continued 
existence of those stocks and the takings would not adversely modify 
critical habitat. The full analysis supporting these conclusions can be 
found in the Biological Opinion.
    Comment 24: In their letter, CBD stated they did not believe NMFS 
should authorize take of CIBWs and other marine mammals but, if NMFS 
did take action to do so, we must impose stringent mitigation measures 
to ensure the least practicable adverse impact on protected species.

[[Page 19309]]

    Response: NMFS has made the required findings to issue the IHAs, 
pursuant to the MMPA, and has issued the IHAs. We have also prescribed 
mitigation measures that effect the least practicable adverse impact on 
marine mammals, in accordance with the MMPA (see Mitigation section).

Description of Marine Mammals in the Area of Specified Activities

    A detailed description of the species likely to be affected by 
POA'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 (84 FR 
72154; December 30, 2019). Please refer to the proposed IHA Federal 
Register notice for these descriptions. Since that notice, there are 
updates to the abundance and trends on one species: CIBWs. We provide a 
summary table of marine mammals that may potentially be present in the 
project area here (Table 3) and a summary of the changes to CIBWs. 
Additional information regarding population trends and threats may be 
found in NMFS's 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's 
website (https://www.fisheries.noaa.gov/find-species). Additional 
information on beluga whales may be found in NMFS' 2016 Recovery Plan 
for the Cook Inlet Beluga Whale (Delphinapterus leucas), available 
online at https://www.fisheries.noaa.gov/resource/document/recovery-plan-cook-inlet-beluga-whale-delphinapterus-leucas.
    Table 3 lists all species with expected potential for occurrence in 
upper Cook Inlet 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.

                                    Table 3--Marine Mammal Species Potentially Occurring in Upper Cook Inlet, Alaska
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                  Stock abundance
                                                                                                  (CV, Nmin, most
          Common name              Scientific name          Stock          ESA/MMPA  status;     recent abundance            PBR            Annual M/SI
                                                                          strategic (Y/N) \1\       survey) \2\                                 \3\
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
     Family Balaenopteridae
           (rorquals)
    Humpback whale.............  Megaptera           Western North       E/D; Y...............  1,107 (0.3, 865,    3...................             2.6
                                  novaeangliae.       Pacific.                                   2006).
                                                     Central North       E/D; Y...............  10,103 (0.3, 7890,  83..................              24
                                                      Pacific.                                   2006).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Beluga whale...............  Delphinapterus      Cook Inlet........  E/D; Y...............  279 (-, 250, 2018)  0.54................               0
                                  leucas.                                                        \4\.
    Killer whale...............  Orcinus orca......  Alaska Resident...  -/-; N...............  2,347 (N/A, 2,347,  24..................               1
                                                                                                 2012).
                                                     Alaska Transient..  -/-; N...............  587 (N/A, 587,      5.9.................               1
                                                                                                 2012).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocoenidae (porpoises):
Harbor porpoise................  Phocoena..........  Gulf of Alaska....  -/-; Y...............  31,046 (0.214, N/   Undet...............              72
                                                                                                 A, 1998).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals
 and sea lions):
    Steller sea lion...........  Eumetopias jubatus  Western...........  E/D; Y...............  54,267 (N/A,        326.................             247
                                                                                                 54,267, 2017).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless
 seals):
    Harbor seal................  Phoca vitulina....  Cook Inlet/         -/-; N...............  28,411 (26,907, N/  807.................             807
                                                      Shelikof.                                  A, 2018).
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
  stock abundance. In some cases, CV is not applicable because it has not been calculated.
\3\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
  fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated
  with estimated mortality due to commercial fisheries is presented in some cases.
\4\ Sheldon and Wade (2019). 95 percent probability range is 250-317 whales.

Update to CIBW Population Estimate

    Until 2020, the best estimate of the CIBW stock was 327 with a 
minimum estimate of 311 whales (Muto et al., 2019). In 2020, NMFS 
released an updated population estimate using a new method to estimate 
group size from the aerial surveys in the analysis of abundance and 
trends for CIBWs (Boyd et al., 2019). This new method replaced the 
method developed by Hobbs et al. (2000, 2015) and has several important 
differences, as these differences contribute to the disparity between 
the

[[Page 19310]]

Hobbs method and the Boyd method. These differences are fully explained 
in Sheldon and Wade (2019). In summary, the new method leads to some 
smaller and some larger group size estimates compared to the older 
Hobbs et al. (2000, 2015) method, when applied to all groups recorded 
during the period 2004-2016. Using the older method, the rate of 
population decline is not as great primarily because the 2016 estimate 
is higher, and there is no 2018 estimate using this older method. 
Annual abundance was calculated as the median of all the daily 
abundance estimates, using all days with an acceptable survey. Using 
the old method, from 2006 to 2016, the rate of decline was estimated to 
be -0.5 percent per year, (with a 70 percent probability the population 
is declining) (Shelden et al. 2017). Using the new method, NMFS found 
from 2008-2018, the estimated trend in the CIBW population is a decline 
of -2.3 percent per year. The abundance estimates indicate there is a 
99.7 percent probability of a decline, and a 93.0 percent probability 
of a decline that is more than 1 percent per year.
    The best estimate of 2018 abundance for the CIBW population from 
the aerial survey data is 279 (95 percent probability interval 250 to 
317). This is based on the estimate of smoothed abundance for 2018, as 
described in Sheldon and Wade (2019). A comparison of the population 
estimates over time is presented in Figure 3. While Sheldon and Wade 
(2019) provides explanations for the differences between model results, 
including inadequacies and biases, the authors do not postulate on the 
reason for population decline in general (which was evident using both 
models); however, recent literature suggests prey reductions may be a 
critical contributing factor (Norman et al., 2019). This is not 
unexpected as reduced prey availability has been directly linked to 
increased mortality and reduced health and survival of other marine 
mammals populations such as the Southern Resident killer whale (e.g., 
Ward et al., 2009, Trites and Rosen, 2017) and California sea lion 
(e.g., McClatchie et al., 2016).
[GRAPHIC] [TIFF OMITTED] TN06AP20.003

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The Federal Register notice for the proposed IHAs (84 FR 72154; 
December 30, 2019) included a discussion of the potential effects of 
the specified activities on marine mammals and their habitat, therefore 
that information is not repeated in detail here; please refer to that 
Federal Register notice for that information. No new data is available 
that suggests the potential responses and impacts to marine mammals 
would differ from those discussed in the notice of proposed IHAs.

[[Page 19311]]

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized through each of the IHAs, which will inform both NMFS' 
consideration of ``small numbers'' and the negligible impact 
determination for the two separate IHAs.
    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 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 
mysticetes, high frequency species, and phocids because predicted 
auditory injury zones are larger than for mid-frequency species and 
otariids. Auditory injury is unlikely to occur for mid-frequency 
species and otariids. The mitigation and monitoring measures are 
expected to minimize the severity of such taking to the extent 
practicable.
    As described previously, no serious injury or 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

    Using the best available science, NMFS has developed 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. In general, 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. However, ambient noise levels within 
Knik Arm are above the 120-dB threshold, and therefore, for purposes of 
this analysis, NMFS considers received levels above those of the 
measured ambient noise (122.2 dB) to constitute Level B harassment of 
marine mammals incidental to continuous noise, including vibratory pile 
driving.
    Results from the most recent acoustic monitoring conducted at the 
port are presented in Austin et al (2016) and Denes et al (2016) 
wherein noise levels were measured in absence of pile driving from May 
27 through May 30, 2016 at two locations: Ambient-Dock and Ambient- 
Offshore. NMFS considers the median sound levels to be most appropriate 
when considering background noise levels for purposes of evaluating the 
potential impacts of the POA's PCT Project on marine mammals. By using 
median value, which is the 50th percentile of the measurements, for 
ambient noise level, one will be able to eliminate the few transient 
loud identifiable events that do not represent the true ambient 
condition of the area. This is relevant because during two of the four 
days (50 percent) when background measurement data were being 
collected, the U.S. Army Corps of Engineers was dredging Terminal 3 
(located just north of the Ambient-Offshore hydrophone) for 24 hours 
per day with two 1-hour breaks for crew change. On the last two days of 
data collection, no dredging was occurring. Therefore, the median 
provides a better representation of background noise levels when the 
PCT project would be occurring. With regard to spatial considerations 
of the measurements, the Ambient-Offshore location is most applicable 
to this discussion as it is consistent with accepted methodology for 
measuring background noise levels. The median ambient noise level 
collected over four days at the end of May at the Ambient-Offshore 
hydrophone was 122.2 dB. We note the Ambient-Dock location was quieter, 
with a median of 117 dB; however, that hydrophone was placed very close 
to the dock and not where we would expect Level B harassment to occur 
given mitigation measures (e.g., shut downs). If additional data 
collected in the future warrant revisiting this issue, NMFS may adjust 
the 122.2 dB rms Level B harassment threshold.
    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). The POA's proposed activity includes the 
use of impulsive (impact pile driving) and non-impulsive (vibratory 
pile driving) sources.
    These thresholds are provided in Table 4 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.

[[Page 19312]]



                     Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                     PTS onset acoustic thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Lpk,flat: 219 dB;           LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Lpk,flat: 230 dB;           LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Lpk,flat: 202 dB;           LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Lpk,flat: 218 dB;           LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Lpk,flat: 232 dB;           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.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]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 
activities that will feed into identifying the areas ensonified above 
the acoustic thresholds, which include source levels and transmission 
loss coefficient.
    The estimated sound source levels and transmission loss coefficient 
used in our analysis are based on direct measurements during 
installation of unattenuated 48-in piles during the POA's 2016 TPP and 
measurements collected during marine construction projects conducted by 
the U.S. Navy. All source levels used in our analysis are presented in 
Table 5. We note that both sound source verification tests (in situ 
measurements at 10 m to refine source levels) as well as measurements 
taken at the estimated Level B harassment isopleths and in the far 
field (+1 km) will be collected at the onset of pile driving to verify 
these estimates.

                                        Table 5--Estimated Sound Source Levels With and Without a Bubble Curtain
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Method and pile size                                        Sound level at 10 m
----------------------------------------------------------------------------------------------------------------------
                                                          Unattenuated \1\                    Bubble curtain                      Data source
                   Vibratory                    ----------------------------------------------------------------------
                                                               db rms                     7 dB reduction, dB rms
--------------------------------------------------------------------------------------------------------------------------------------------------------
144-in.........................................                               178                                171   Caltrans 2015.
48-in..........................................                               168                                161   Austin et al 2016.
36-in..........................................                               166                                159   Navy 2015.
24-in..........................................                               161                                154   Navy 2015.
--------------------------------------------------------------------------------------------------------------------------------------------------------


 
                                       Unattenuated \1\                  Bubble curtain
            Impact            ------------------------------------------------------------------
                                 dB rms     dB SEL    dB peak     dB rms     dB SEL    dB peak
----------------------------------------------------------------------------------------------------------------
144-in.......................        209        198        220        202        191       213.  Caltrans 2015
48-in........................        200        187        215        193        180        208  Austin et al
                                                                                                  2016.
36-in........................        194        184        211        187        177        204  Navy 2015.
24-in........................        193        181        210        186        174        203  Navy 2015.
----------------------------------------------------------------------------------------------------------------
\1\ We note the only piles that may be driven or removed without a bubble curtain are 24-in battered piles. We
  included unattenuated SLs here for 36-in, 48-in, and 144-in piles to demonstrate how the 7dB reduction for
  bubble curtains was applied.

    During the TPP, JASCO computed transmission loss (TL) coefficients, 
derived from fits of the received sound level data versus range. TL 
coefficients varied between piles with values ranging from 13 to 19.2 
for impact pile driving and from 12.6 to 17.9 for vibratory pile 
driving when using sound attenuation devices. Results for the 
unattenuated hydraulic impact hammer yielded the highest TL 
coefficient, 19.2, indicating that sounds from the hydraulic impact 
hammer decayed most rapidly with range compared to the other hammers. 
The TL coefficient for the unattenuated diesel impact hammer averaged 
17.5. Sounds from the unattenuated vibratory hammer had the lowest TL 
coefficient, with values of 16.1 and 16.9.
    Based on these data, the POA proposed different transmission loss 
rates depending on if SEL (used for Level A harassment) or rms (used 
for Level B harassment) values were being evaluated. SPLrms is a 
pressure metric and SEL an energy metric. The difference in TL 
coefficient is a reflection of how SPLrms or SEL is dissipated in the 
marine environment. During underwater sound propagation, pressure 
amplitude tends to suffer more loss due to multipath propagation and 
reverberation, while acoustic energy does not dissipate as rapidly. 
Accordingly, the POA proposed using TL rate of 16.85 for assessing 
potential for Level A harassment from impact pile driving but a TL rate 
of 18.35, based on Austin et al. (2016), when assessing potential for 
Level B harassment from impact pile driving. For vibratory pile

[[Page 19313]]

driving, SPLrms is used for both Level A harassment and Level B 
harassment analysis and, based on Austin et al. (2016) the POA applied 
a TL rate of 16.5. NMFS found these transmission loss rates acceptable 
and carried them forward in our analysis. Again, on site acoustic 
monitoring in both the near and far field (to capture any sediment-
borne noise) at the onset of pile driving will verify estimates made in 
our analysis.
    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 closest distance at which, 
if a marine mammal remained at that distance the whole duration of the 
activity, it would not incur PTS.
    The User Spreadsheet also includes a default, single frequency 
weighting factor adjustment (WFA) to account for frequency hearing 
groups. During the 2016 TPP, the POA collected direct measurements of 
sound generated during installation of 48-in piles. The spectra 
associated with impact and vibratory driving 48-in unattenuated piles 
was also derived. Therefore, we accepted POA's applied spectra approach 
for 48-in piles but relied on the User Spreadsheet default WFA for all 
other pile sizes.
    Inputs used in the User Spreadsheet for 24-in, 36-in and 144-in 
pilesare reported in Table 6.

                                                          Table 6--NMFS User Spreadsheet Inputs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 24-in  (bubble          36-in  (bubble         48-in  (bubble        144-in  (bubble
                                      24-in  (unattenuated)         curtain)                curtain)               curtain)               curtain)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                User Spreadsheet Input: Impact Pile Driving (TL = 16.85)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used...............  (E.1) Impact pile       (E.1) Impact pile       (E.1) Impact pile      (E.1) Impact pile      (E.1) Impact pile
                                      driving.                driving.                driving.               driving.               driving.
Source Level (Single Strike/shot     181...................  174...................  177..................  180..................  191
 SEL).
Weighting Factor Adjustment (kHz)..  2.....................  2.....................  2....................  measured spectra.....  2
Number of strikes pile.............  50 (re-strikes).......  50 (re-strikes).......  3,000................  2,300 or 3,000.......  5,000
Piles per day......................  1-4...................  1-4...................  1-3..................  1-3..................  0.3 or 0.7
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                               User Spreadsheet Input: Vibratory Pile Driving (TL = 16.5)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                              24-in                   24-in                  36-in                  48-in                  144-in
                                     (unattenuated)........  (bubble curtain)......  (bubble curtain).....  (bubble curtain).....  (bubble curtain)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used...............  (A) Non-Impul, Stat,    (A) Non-Impul, Stat,    (A) Non-Impul, Stat,   (A) Non-Impul, Stat,   (A) Non-Impul, Stat,
                                      Cont..                  Cont..                  Cont..                 Cont..                 Cont.
Source Level (SPL RMS).............  161...................  154...................  159..................  161..................  171
Weighting Factor Adjustment (kHz)..  2.5...................  2.5...................  2.5..................  measured spectra.....  2.5
Time to drive single pile (minutes)  75....................  75....................  75...................  30...................  45
 \1\.
Piles per day......................  1-4...................  1-4...................  1-4..................  1 \2\................  1
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ In some cases, only 30 minutes may be required to drive a pile using a vibratory hammer; however, here we default to the greatest amount of time
  indicated per pile.
\2\ The POA indicated a vibratory hammer would only be used if an obstruction is encountered; therefore, the most probable scenario is, at most, only
  one 48-in pile per day would require use of a vibratory hammer.

    To calculate the Level B harassment isopleths, NMFS considered 
SPLrms source levels and the corresponding TL coefficients of 18.35 and 
16.5 for impact and vibratory pile driving, respectively. The resulting 
Level A harassment and Level B harassment isopleths are presented in 
Table 7.

           Table 7--Distances to Level A Harassment, by Hearing Group, and Level B Harassment Thresholds per Pile Type and Installation Method
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                          Piles                    Level A harassment (m)
           Pile size                Hammer type        Attenuation     installed/ -------------------------------------------------------     Level B
                                                                           day         LF         MF         HF         PW         OW     harassment (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
48-in (2,300 strikes per pile).  Impact...........  Bubble Curtain...           1        655         34        766        376         36         \1\ 824
                                                                                2        989         51      1,156        567         55
                                                                                3      1,258         65      1,470        721         70

[[Page 19314]]

 
48-in (3,000 strikes per pile).  Impact...........  Bubble Curtain...           1        767         39        897        440         43             824
                                                                                2      1,158         59      1,353        664         64
                                                                                3      1,473         76      1,721        844         82
48-in..........................  Vibratory........  Bubble Curtain...           1          5          1          7          3          0           2,247
36-in..........................  Vibratory........  Bubble Curtain...           3         12          1         17          8          1           1,699
                                                                                4         14          2         20          9          1
                                 Impact...........  Bubble Curtain...           1        509         26        595        292         28             296
                                                                                2        768         39        898        440         43
                                                                                3        978         50      1,142        560         54
24-in..........................  Vibratory........  Bubble Curtain...           3          3          0          5          2          0             846
                                                                                4          7          1         10          4          0
                                 .................  Unattenuated (6             3         16          2         22         10          1           2,247
                                                     battered piles
                                                     in Phase 2).
                                                                                4         19          2         27         12          1
                                 Impact (50 re-     Bubble Curtain...           1         30          2         35         17          2             261
                                  strikes per
                                  pile) \2\.
                                                                                4         68          4         79         39          4
                                 .................  Unattenuated (6             1         78          4         91         44          4             629
                                                     battered piles
                                                     in Phase 2).
                                                                                4        176          9        206        101         10
144-in.........................  Impact...........  Bubble Curtain...         0.3      2,286        117      2,672      1,311        127           1,945
                                                                              0.7      3,781        194      4,418      2,167        210           1,945
                                 Vibratory........                              1         24          3         34         15          1           9,069
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The Level B harassment isopleth of 824 m is an average of modeled distances based on in situ data presented in Austin et al. (2016; Table 12).
\2\ For impact hammering of 24-in temporary piles, we include information only for one or four piles, to provide the general range of very small zones.
  The number of piles may vary from one to four piles per day.

Marine Mammal Occurrence and Take Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals and present take 
calculations.
    For all species of cetaceans other than beluga whales, density data 
is not available for upper Cook Inlet. Therefore, the POA relied on 
marine mammal monitoring data collected during past POA projects. These 
data cover the construction season (April through November) across 
multiple years. Estimated exposure from pile installation for all 
marine mammals except beluga whales is calculated by the following 
equation: Exposure estimate = N * # days of pile installation, where: N 
= highest daily abundance estimate for each species in project area 
across all years of data.

Harbor Seals

    Marine mammal monitoring data collected during previous POA 
projects were used to estimate daily sighting rates for harbor seals in 
the project area (see Table 4-1 in POA's application). The highest 
individual sighting rate recorded for a previous year was used to 
quantify take of harbor seals for pile installation associated with the 
PCT. The number of sightings of harbor seals during 2016 TPP 
construction monitoring was 28 sightings recorded over 83.5 hours of 
monitoring from May 3 through June 21, 2016. Based on these 
observations, the sighting rate during the 2016 TPP construction 
monitoring period was one harbor seal every 3 hours, or approximately 
four harbor seals per 12-hour work day. Given the likely increase in 
harbor seal abundance over the years, the POA and NMFS doubled this 
number to estimate take (i.e., up to 8 seals per day could be taken by 
harassment). However, the Commission commented that because previous 
monitoring data indicated a maximum of nine seals were observed on a 
particular day during previous monitoring, we should use 9 seals (not 
8) for days when Level B harassment zones are within 2 km and double 
this number (18 seals per day) when Level B harassment zones extend to 
4 kms since all seals were observed within 2 kms, as they are difficult 
to observe beyond this distance. While this is conceptually a 
reasonable alternative, the take numbers resulting from use of 8 seals 
per day far exceed what the years of monitoring data indicate as 
reasonable estimates of potential harassment. Over the course of 8 
years of data (no monitoring was conducted in 2012, 2013, and 2014 as 
no pile driving was conducted at the POA during these years), the 
maximum number of seals observed in a year (2009) was 57 seals (while 
other years ranged from 0-34 seals total). The monitoring conducted 
during 2009 was extensive (3,222 hours over 214 days from March through 
December). The average number of seals observed per year across all 
years of monitoring was 17 seals. Therefore, it is reasonable to assume 
our originally proposed take estimates are more than sufficient to 
account for potential harassment from the PCT project, as the take 
estimates for Phase 1 and Phase 2 are more than 17 and 10 times the 
maximum number of seals observed in any given prior year, respectively. 
This 10 to 17 fold increase adequately accounts for seals present at 
greater than 2 kms. Therefore, we maintain our original take estimate 
approach.
    Pile installation and removal is anticipated to take approximately 
127 days for Phase 1 and 75 days for Phase 2. Therefore, we estimate no 
more than 1,016 instances of harbor seal take during Phase 1 (8 harbor 
seals per day * 127 days) and 600 instances of harbor seal take (8 
harbor seals per day * 75 days) during Phase 2.
    The mouth of Ship Creek, where harbor seals tend to concentrate is 
located approximately 700 m from the southern end of the PCT, and is 
therefore located outside the harbor seal Level A harassment zone for 
the majority of pile sizes for both impact and vibratory pile 
installation. However, there is potential for Level A harassment near 
Ship Creek during installation of three 48-in piles per day and 
installation of 144-in piles. We estimate

[[Page 19315]]

30 percent of the estimated take could be in the form of Level A 
harassment, as approximately 30 percent of the work may result in Level 
A harassment isopleths extending to Ship Creek. Therefore, the POA has 
requested, and NMFS has authorized 305 Level A harassment and 711 Level 
B harassment takes in Phase 1 and 180 Level A harassment and 420 Level 
B harassment takes in Phase 2.

Steller Sea Lions

    Steller sea lions are anticipated to be encountered in low numbers, 
if at all, within the project area. Three sightings of what was likely 
a single individual occurred in the project area in 2009 and two 
sightings occurred in 2016. Based on observations in 2016, we 
anticipate an exposure rate of 2 individuals every 19 days during PCT 
pile installation and removal. Based on this rate, we are authorizing 
13 sea lion takes during Phase 1 (127 days * [2 sea lions every 19 
days]) and 8 Steller sea lion takes during Phase 2 (75 days for Phase 2 
* [2 sea lions every 19 days]). During installation of 144-in piles 
(Phase 2), the Level A harassment isopleth extends beyond 100 m. 
Although Steller sea lions are readily detectable at these distances, 
we are not requiring the POA to shut down if a Steller sea lion is 
observed. Steller sea lions are rarely present in Knik Arm; however, 
they can linger in the area for multiple days. During Phase 1, the 
Level A harassment isopleth is less than the 100 m shutdown zone for 
all scenarios; therefore, the potential for Level A harassment take is 
discountable. During installation of the 144-in piles in Phase 2, there 
is a low potential for Level A harassment and an animal may remain for 
a couple of days; therefore, we allocate two takes in Phase 2 to Level 
A harassment.

Harbor Porpoise

    Previous monitoring data at the POA were used to evaluate daily 
sighting rates for harbor porpoises in the project area. During most 
years of monitoring, no harbor porpoises were observed. The highest 
individual sighting rate for any recorded year during pile installation 
and removal associated with the PCT was an average of 0.09 harbor 
porpoises per day during 2009 construction monitoring, but this value 
may not account for increased sightings in Upper Cook Inlet (Shelden et 
al. 2014). Therefore, the POA assumed that one harbor porpoise could be 
observed every 2 days of pile driving. Based on this assumption, the 
POA has requested, and NMFS has authorized, 64 takes during Phase 1 
(127 days * [1 harbor porpoise every 2 days]) and 38 takes during Phase 
2 (75 days for Phase 2 * [1 harbor porpoise every 2 days]). This 
estimate also covers the possibility that larger groups (2-3 
individuals) of harbor porpoise could occur occasionally.
    Harbor porpoises are relatively small cetaceans that move at high 
velocities, which can make their detection and identification at great 
distances difficult. Using the NMFS User Spreadsheet, impact driving 
36-in, 48-in and 144-in piles results in Level A harassment isopleths 
larger than the Level B harassment isopleth. Vibratory driving and 
removal result in much smaller Level A harassment zones than Level B 
harassment zones and many temporary piles (the bulk of the work) would 
be installed and removed with a vibratory hammer. Further, the Level A 
harassment isopleths consider long durations and harbor porpoise are 
likely moving through the area, if present, not lingering. Therefore, 
we authorized approximately one-third of the total expected take in the 
form of Level A harassment. For Phase 1, we authorized 21 takes by 
Level A harassment and 43 takes by Level B harassment. For Phase 2, we 
authorized 13 Level A harassment and 25 Level B harassment takes.

Killer Whales

    Few, if any, killer whales are expected to approach the project 
area. No killer whales were sighted during previous monitoring programs 
for the Knik Arm Crossing and POA construction projects, including the 
2016 TPP. The infrequent sightings of killer whales that are reported 
in upper Cook Inlet tend to occur when their primary prey (anadromous 
fish for resident killer whales and beluga whales for transient killer 
whales) are also in the area (Shelden et al. 2003). Previous sightings 
of transient killer whales have documented pod sizes in upper Cook 
Inlet between one and six individuals (Shelden et al. 2003). The 
potential for exposure of killer whales within the Level B harassment 
isopleths is anticipated to be extremely low. Level B harassment take 
is conservatively estimated at no more than 12 individuals during Phase 
1 and Phase 2 to account for two large (n=12) groups or several smaller 
groups. No Level A harassment take for killer whales is anticipated or 
authorized due to the small Level A harassment zones and implementation 
of a 100 m shutdown which is larger than Level A harassment isopleths.

Humpback Whales

    Sightings of humpback whales in the project area are rare, and the 
potential risk of exposure of a humpback whale to sounds exceeding the 
Level B harassment threshold is low. Few, if any, humpback whales are 
expected to approach the project area. However, there were two 
sightings in 2017 of what was likely a single individual at the Ship 
Creek Boat Launch (ABR 2017) which is located south of the project 
area. Based on these data, the POA conservatively estimates one 
humpback whale could be harassed every 16 days of pile driving. 
Therefore, the POA requested 8 humpback whale takes during Phase 1 (127 
days for Phase 1 * [1 humpback whale every 16 days]) and 5 takes (75 
days for Phase 2 * [1 humpback whale every 16 days]) for Phase 2. This 
could include sighting a cow-calf pair on multiple days or multiple 
sightings of single humpback whales. The POA did not request Level A 
harassment take of humpback whales; however, based on the large 
distances to the Level A harassment thresholds relative to Level B 
harassment isopleths and the fact humpback whale sightings in Upper 
Cook Inlet are rare, NMFS authorized two Level A harassment takes per 
year to account for a single individual or a cow/calf pair. Therefore, 
NMFS has authorized two Level A harassment takes and six Level B 
harassment takes during Phase 1 and two Level A harassment takes and 
three Level B harassment takes for Phase 2.

Beluga Whales

    For beluga whales, we looked at several sources of information on 
marine mammal occurrence in upper Cook Inlet to determine how best to 
estimate the potential for exposure to pile driving noise from the PCT 
Project. In their application, the POA took a two-step approach to 
estimating Level B harassment take. The POA first estimated the numbers 
of beluga whales potentially exposed to noise levels above the Level B 
harassment threshold for pile installation and removal using the 
following formula: Beluga Exposure Estimate = N * Area * number of days 
of pile installation/removal, where: N = maximum predicted # of beluga 
whales/km\2\ in Knik Arm (0.291 whales/km\2\) based on data from Goetz 
et al. (2012a) and Area = Area ensonified above Level B harassment 
threshold (km\2\). We note the actual beluga whale densities within the 
Level B harassment isopleths predicted for the PCT project ranged from 
0.042 to 0.236 beluga whales/km\2\. However, the POA applied the 
highest beluga whale density in upper Knik Arm. The higher densities 
north of the POA are expected as beluga whales tend to concentrate in 
Eagle Bay to forage whereas in the lower Arm, where the

[[Page 19316]]

POA is located, habitat use is more commonly associated with traveling. 
The POA's simple calculation results in 103 takes in Phase 1 and 125 
takes in Phase 2. The second step in POA's take estimate approach was 
to apply a 50 percent correction factor to their density-based 
calculation. The POA provided several reasons why this reduction factor 
was appropriate, including, but not limited to: The POA's commitment to 
using a bubble curtain means that noise levels along the western side 
of Knik Arm will remain below the regulatory thresholds; providing a 
travel corridor for beluga whales to access upper Knik Arm; for the 
majority of PCT construction and pile installation and removal, only 
approximately half of the width of Knik Arm, along the eastern shore, 
would be ensonified; beluga whales observed in Knik Arm during the 
autumn were most frequently sighted on the western side of the arm 
(Funk et al. 2005); and beluga whales are present in Knik Arm year-
round, but sightings are much lower in winter through early summer.
    We reviewed the POA's density-based take calculation approach and 
their reasons for applying a 50 percent correction factor. We 
determined use of the Goetz density data for this specific project does 
not represent the best available scientific information in this 
circumstance because the density data is based on June aerial surveys 
while the PCT project is occurring from April through November, the 
data is over seven years old, and the multiple years of monitoring data 
collected by the POA is not incorporated into this approach. Regarding 
the rationale for applying a 50 percent correction factor, we found the 
use of a bubble curtain and the fact the majority of pile driving would 
ensonify half or less than half of the width of Knik Arm is already 
captured by the ensonsified area which is embedded into the take 
calculation. The POA is not pile driving during winter when beluga 
whale abundance is lowest and although early summer tends to see lower 
beluga abundance, the density used in the take calculation is from June 
surveys.
    To better capture beluga whale distribution and abundance, we 
undertook a multi-step analysis consisting of an evaluation of long-
term, seasonal sighting data, mitigation and monitoring measures, the 
amount of documented exposure from previous POA projects compared to 
authorized take, and considered group size. First, in lieu of density 
data, NMFS applied sighting rate data presented in Kendell and Cornick 
(2015) to estimate hourly sighting rates per month (April through 
November). We then identified hours of pile driving per month. The POA 
indicated there will be extended durations when no pile driving is 
happening (e.g., later in the season when decking and other out-of-
water work is occurring); however, the schedule could not be more 
refined than assuming an equal work distribution across the 
construction season. The POA did indicate the first two weeks of April 
and the last two weeks in November would be most likely utilized for 
equipment mobilization and demobilization; therefore, pile driving 
effort during those months were limited to two weeks. The data and 
calculated exposure estimates are presented below in Table 8. These 
calculations assume no mitigation (i.e., uncorrected take estimates) 
and that all animals observed would enter a given Level B harassment 
zone during pile driving. In total, we would expect approximately 94 
exposures in Phase 1 and 60 exposures in Phase 2.

                                      Table 8--Uncorrected Beluga Whale Exposure Estimates for Phase 1 and Phase 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                        Monitoring data \1\                                 Estimated instances of take
                                         ---------------------------------------------------------------------------------------------------------------
                  Month                                      Number of                     Pile driving        CIBW        Pile driving        CIBW
                                           Effort hours       whales      Average whale/  hours  phase 1     exposures    hours  phase 2     exposures
                                                             observed           hr              \2\           phase 1           \2\           phase 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
April...................................              12               2            0.17           25.64            4.27           16.37            2.73
May.....................................             156              40            0.26           51.29           13.15           32.71            8.39
June....................................             280               8            0.03           51.29            1.47           32.71            0.94
July....................................             360               2            0.01           51.29            0.28           32.71            0.18
August..................................             426             269            0.63           51.29           32.38           32.71           20.65
Sept....................................             447             169            0.38           51.29           19.37           32.71           12.35
October.................................             433              22            0.05           51.29            2.61           32.71            1.66
Nov.....................................             215             175            0.82           25.64           20.91           16.37           13.35
                                         ---------------------------------------------------------------------------------------------------------------
    Total...............................           2,317             685            0.30          359.02           94.44          229.00           60.25
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ From Kendell and Cornick 2015.
\2\ Assumes equal work distribution/month except in April and November when the POA has indicated they would be conducting only 2 weeks of pile driving
  due to time needed for mobilization and demobilization.

    NMFS then considered the prescribed mitigation as well as 
distribution of beluga whales in Knik Arm. In the POA's application, 
they proposed a 100-m shutdown zone for all marine mammals. However, as 
described in more detail below, NMFS has prescribed additional 
mitigation designed to reduce Level B harassment take as well as avoid 
Level A harassment take. We recognize that in certain situations, pile 
driving may not be able to be shut down prior to whales entering the 
Level B harassment zone due to safety concerns. During previous 
monitoring, sometimes beluga whales were initially observed when they 
surfaced within the harassment zone. For example, on November 4, 2009, 
15 whales were initially sighted approximately 950 meters north of the 
project site near the shore, and then they surfaced in the Level B 
harassment zone during vibratory pile driving (ICRC 2009b). 
Construction activities were immediately shut down, but the 15 whales 
were nevertheless exposed within the Level B harassment zone. On other 
occasions, beluga whales were initially sighted outside of the 
harassment zone and shutdown was called, but the beluga whales swam 
into the harassment zone before activities could be halted, and 
exposure within the harassment zone occurred. For example, on September 
14, 2009, a construction observer sighted a beluga whale just outside 
the harassment zone, moving quickly towards the 1,300 m Level B 
harassment zone during vibratory pile driving. The animal entered the 
harassment zone before construction activity could be shut down (ICRC 
2009c). However, we note that for the PCT, there will be four PSO

[[Page 19317]]

stations, with the southern-most station near Point Woronzof and the 
northern-most station at the north end of POA property (immediately 
south of Cairn Point). No less than 11 PSOs will be on watch at any 
given time during days pile driving is occurring. In addition, we 
expect the Level B harassment zones for a majority of work to be 
smaller than previous zones given the use of the confined bubble 
curtain system with the casing pile. For these reasons, we believe the 
ability to detect whales and shut down prior to them entering the Level 
B harassment zones will be enhanced from previous years.
    To more accurately estimate potential exposures than simply using 
the uncorrected numbers, which does not account for any mitigation, we 
looked at previous monitoring results at the POA in relation to 
authorized take numbers. Between 2008 and 2012, NMFS authorized 34 
beluga whale takes per year to POA, with the same Level B harassment 
shutdown mitigation measure that are included in the IHAs (we note that 
in these IHAs, we have also included additional mitigation designed to 
reduce the potential for take). The percent of the authorized takes 
that may have occurred as a result of documented exposures within 
harassment zones during this time period ranged from 12 to 59 percent 
with an average of 36 percent (Table 9). The previous method of 
estimating take was based on density; however, the results between 
using densities versus sighting rate are somewhat comparable (e.g., 94 
exposures in Phase 1 using sighting rates versus 103 exposures using 
the highest density in Knik Arm). Further, there was extensive 
scientific monitoring and POA construction monitoring occurring during 
these time periods; therefore, we believe there is little potential 
that animals were taken but not observed. Therefore we believe this 
first step in our analysis is reasonable.

            Table 9--Authorized and Reported Beluga Whale Takes during POA activities from 2009-2012
----------------------------------------------------------------------------------------------------------------
                                                                                                    Percent of
                       ITA effective dates                        Reported takes    Authorized      authorized
                                                                                       take       takes occurred
----------------------------------------------------------------------------------------------------------------
15 July 2008-14 July 2009.......................................              12              34              35
15 July 2009-14 July 2010.......................................              20              34              59
15 July 2010-14 July 2011.......................................              13              34              38
15 July 2011-14 July 2012.......................................               4              34              12
----------------------------------------------------------------------------------------------------------------

    Second, we applied the highest percentage of previous takes (59 
percent) to ensure potential impacts to beluga whales are adequately 
evaluated. Therefore, we assume that approximately 59 percent of the 
takes calculated for Phase 1 (n=94) and Phase 2 (n=64) will actually be 
realized. This approach is further supported by the mitigation 
measures, which are strict shutdown requirements for CIBWs, with a goal 
of avoiding Level B harassment take altogether.
    Finally, we then considered group size from the long-term 
scientific monitoring effort and POA opportunistic data to determine if 
these numbers represented realistic scenarios. Figure 4 presents data 
from the scientific monitoring program. The scientific monitoring data 
set documented 390 beluga whale sightings.
[GRAPHIC] [TIFF OMITTED] TN06AP20.004

    Group size exhibits a mode of 1 and a median of 2, indicating that 
over half of the beluga groups observed over the 5-year span of the 
monitoring program were of individual beluga whales or groups of 2. The 
95th percentile of group size from the APU scientific monitoring data 
set is 11.1 beluga whales. This means that, of the 390 documented 
beluga whale groups in this data set, 95 percent consisted of fewer 
than 11.1 whales; 5 percent of the groups consisted of more than 11.1 
whales. We conclude the amount of take authorized following the 
approach above allows for the potential for both several small and some 
large groups to be exposed to noise above NMFS

[[Page 19318]]

harassment thresholds. When considering the extensive monitoring (four 
PSO locations) and mitigation never before required (e.g., pre-
clearance of greater than the Level B harassment zone), the amount of 
take authorized is justified.
    For reasons described above, NMFS believes this approach adequately 
analyzes the risk of beluga whale exposure to Level B harassment from 
the PCT Project. We conclude there is the potential for 55 exposures in 
Phase 1 and 35 exposures in Phase 2 (Table 10).

           Table 10--Beluga Whale Level B Harassment Exposures
------------------------------------------------------------------------
                                            Calculated      Authorized
         PCT construction phase              exposure        take \1\
------------------------------------------------------------------------
Phase 1--2020...........................              94              55
Phase 2--2021...........................              60              35
------------------------------------------------------------------------
\1\ Authorized take is identified as 59 percent of the calculated
  exposures using sighting rates.

    In summary, the total amount of Level A harassment and Level B 
harassment authorized for each marine mammal stock is presented in 
Table 11.

                        Table 11--Authorized Amount of Take, by Stock and Harassment Type
----------------------------------------------------------------------------------------------------------------
                                                         Phase 1 (2020)                   Phase 2 (2021)
                                               -----------------------------------------------------------------
           Species                  Stock                              Percent                          Percent
                                                 Level A    Level B    of stock   Level A    Level B    of stock
----------------------------------------------------------------------------------------------------------------
Humpback whale...............  Central or               2          6        0.7          2          3        0.7
                                Western N
                                Pacific.
Beluga whale.................  Cook Inlet.....          0         55       19.7          0         35       12.5
Killer whale.................  Transient/               0         12          2          0         12          2
                                Alaska
                                Resident.
Harbor porpoise..............  Gulf of Alaska.         21         43        0.2         13         25        0.2
Steller sea lion.............  Western........          0         13       <0.1          2          6       <0.1
Harbor seal..................  Cook Inlet/            305        711        3.6        180        420        2.1
                                Shelikof.
----------------------------------------------------------------------------------------------------------------

Mitigation

    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 such 
activity, and other means of effecting the least practicable adverse 
impact on such species or stock and its habitat, paying particular 
attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of such 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 such 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. 
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.
    The POA presented mitigation measures in section 11 of their 
application that NMFS found did not effect the least practicable 
adverse impact on marine mammals, namely CIBWs. Therefore, NMFS worked 
with the POA to greatly improve on mitigation measures that both reduce 
noise into the aquatic environment and reduce the potential for CIBWs 
to be adversely impacted from any unavoidable noise exposure.
    A key mitigation measure NMFS considered for this project is 
reducing noise levels propagating into the environment. The POA will 
use a confined bubble curtain on all piles in Phase 1 when water depth 
is deep enough to deploy the bubble curtain. At this time, NMFS is not 
requiring an confined bubble curtain for Phase 2 because the contractor 
has not been chosen by POA at this time, the effectiveness of the 
confined bubble curtain will be proven during Phase 1 and currently, 
there is no casing pile large enough to encapsulate 144-in piles. 
However, at minimum, an unconfined bubble curtain will be required for 
all plumb piles in Phase 2.
    In addition to noise attenuation devices, NMFS considered 
practicable work restrictions. For installation of 144-in piles 
included in Phase 2 (2021), NMFS has determined that given the 
extensive Level B harassment zone generated from this activity, 
vibratory driving these large piles during peak beluga whale season 
poses an amount of risk and uncertainty to the degree that it should be 
minimized. This August peak is confirmed through acoustic monitoring 
(Castellote et al. 2020) where the authors indicate beluga whales 
appeared concentrated in the upper inlet year-round, but particularly 
feeding in river mouths from April-December, shifting their 
geographical foraging preferences from the Susitna River region towards 
Knik Arm in mid-August, and dispersing towards the mid inlet throughout 
the winter. Therefore, vibratory driving 144-in piles will not

[[Page 19319]]

occur during August. Further, to minimize the potential for overlapping 
sound fields from multiple stressors, the POA will not simultaneously 
operate two vibratory hammers for either pile installation or removal. 
This measure is designed to reduce simultaneous in-water noise 
exposure. Because impact hammers will not likely be dropping at the 
same time, and to expedite construction of the project to minimize pile 
driving during peak beluga whale abundance periods, NMFS is not 
proposing to restrict the operation of two impact hammers at the same 
time.
    NMFS also considered other means by which to remove piles since the 
majority of piles installed for this project are temporary. NMFS 
inquired about the potential to direct pull piles or cut them off at 
the mudline; thereby, reducing in-water noise levels. The POA responded 
that the depth at which temporary piles would be installed and 
substrate type precludes directly pulling the piles. Cutting piles at 
the mudline also presents navigational (e.g., anchoring) and safety 
concerns. Therefore, temporary piles will be removed with a vibratory 
hammer; however, all will be done so in the confines of a bubble 
curtain.
    In their IHA application, the POA proposed a 100-m shutdown zone 
for all marine mammals or, where the Level A harassment zone was deemed 
to be greater than 100 m, a shutdown zone equivalent to the Level A 
harassment zone. NMFS found this measure did not effect the least 
practicable adverse impact on all marine mammals for several reasons.
    First, except for 48-in piles, the Level A harassment zones in the 
application were based on estimated spectra, a methodology that NMFS 
does not believe appropriate. Therefore, NMFS calculated Level A 
harassment zones for all piles (except 48-in piles) using the single 
frequency, default weighting factor adjustment provided in the NMFS 
User Spreadsheet. As shown in Table 7, Level A harassment zones for 
low-frequency and high frequency cetaceans and pinnipeds are relatively 
large when considering multiple piles installed per day and 
installation of the 144-in piles. Sighting rates at these distances, 
specifically for harbor seals and porpoise, are likely ineffective to 
avoid take. Therefore, the POA's proposal to shutdown at the Level A 
harassment zone is unlikely to be effective for smaller species (i.e., 
harbor seal and harbor porpoise). Therefore, while the POA has the 
liberty to shutdown at greater than 100 m; this is likely a more 
reasonable distance to observe these small, erratic species, making the 
mitigation measure more effective. For these reasons, the IHAs include 
a 100-m shutdown zone for all marine mammals (except CIBWs) and has 
issued Level A take, where appropriate.
    For beluga whales, NMFS determined the proposed shutdown zone of 
100 m or the Level A harassment zone (if greater than 100 m) was not 
consistent with the conservation intentions of the POA nor what NMFS 
would consider as effecting the least practicable adverse impact based 
on the proposed project description and acoustic analysis. NMFS and the 
POA entered into discussions to address these issues and have 
determined that measures from previous IHAs should be carried over 
(e.g., shutdown at the Level B harassment zone) but additional measures 
would ensure valuable protection and conservation of CIBWs. Therefore, 
NMFS has included mitigation measures exceeding those proposed by the 
POA in their application:
     Prior to the onset of pile driving, should a CIBW be 
observed approaching the mouth of Knik Arm, pile driving will be 
delayed. This in-bound pre-clearance line extends from Point Woronzof 
to approximately 2.5 kms west of Point McKenzie. Pile driving may 
commence once the whale(s) moves at least 100 m past the Level B 
harassment zone and on a path away from the zone. A similar pre-pile 
driving clearance zone will be established to the north of the POA 
(from Cairn Point to the opposite bank), allowing whales to leave Knik 
Arm undisturbed. Similar to the in-bound whale clearance zone, pile 
driving may not commence until a whale(s) moves at least 100 m past the 
Level B harassment zone and on a path away from the zone. If non-beluga 
whale species are observed within or likely to enter the Level B 
harassment zone prior to pile driving, the POA may commence pile 
driving but only if those animals are outside the 100 m shutdown zone.
     If pile driving has commenced and a CIBW is observed 
within or likely to enter the Level B harassment zone, pile driving 
will shut down and not re-commence until the whale is out of and on a 
path away from the Level B harassment zone or until no beluga whale has 
been observed in the Level B harassment zone for 30 minutes.
     If vibratory hammering is required on a 144-in pile, it 
may not be possible to monitor the entire Level B harassment zone, as 
this zone may extend beyond the pre-clearance zone. In this case, the 
pre-clearance zone remains applicable.
     If, during pile driving 24-, 36-, and 48-in piles, PSOs 
can no longer effectively monitor all waters within the CIBW Level B 
harassment due to environmental conditions (e.g., fog, rain, wind), 
pile driving may continue only until the current segment of pile is 
driven; no additional sections of pile or additional piles may be 
driven until conditions improve such that the Level B harassment zone 
can be effectively monitored. If the Level B harassment zone cannot be 
monitored for more than 15 minutes, the entire Level B harassment zone 
must be cleared again for 30 minutes prior to pile driving.
    In addition to these measures which greatly reduce the potential 
for harassment to CIBWs and establish shutdown zones that realistically 
reflect non-beluga whale detectability, NMFS is including the following 
additional mitigation measures:
     PSOs shall begin observing for marine mammals 30 minutes 
before pile driving begins for the day and must continue for 30 minutes 
when pile driving ceases at any time. If pile driving has ceased for 
more than 30 minutes within a day, another 30-minute pre-pile driving 
observation period is required before pile driving may commence.
     If a marine mammal is entering or is observed within an 
established shutdown zone, pile driving must be halted or delayed. Pile 
driving may not commence or resume until either the animal has 
voluntarily left and been visually confirmed beyond the shutdown zone 
or 15 minutes (non-CIBW) or 30 minutes (CIBW) have passed without 
subsequent detections. NMFS may adjust the shutdown zones pending 
review and approval of an acoustic monitoring report.
     POA must use soft start techniques when impact pile 
driving. Soft start requires contractors to provide an initial set of 
three strikes at reduced energy, followed by a thirty-second waiting 
period, then two subsequent reduced energy strike sets. A soft start 
must 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.
     For in-water construction other than pile driving, the POA 
must cease operations or reduce vessel speed to the minimum level 
required to maintain steerage and safe working conditions if a marine 
mammal approaches within 10 m of the equipment or vessel.
     POA is required to conduct briefings for construction 
supervisors and crews, the monitoring team, and POA staff prior to the 
start of all pile driving activity, and when new personnel join the 
work, in order to

[[Page 19320]]

explain responsibilities, communication procedures, the marine mammal 
monitoring protocol, and operational procedures.
     If a species for which authorization has not been granted, 
or a species for which authorization has been granted but the 
authorized takes are met, is observed approaching or within the 
monitoring zone (Table 7), pile driving and removal activities must 
shut down immediately using delay and shut-down procedures. Activities 
must not resume until the animal has been confirmed to have left the 
area or the 15 (non-CIBW) or 30 (CIBW) minute observation period has 
elapsed.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has determined that the 
mitigation measures provide the means of effecting the least 
practicable adverse impact on the affected species or stocks and their 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance and on the availability of such species 
or 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 
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:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density).
     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).
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors.
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks.
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat).
     Mitigation and monitoring effectiveness.
    During the 2016 TPP, observers for that project provided a number 
of recommendations to improve marine mammal monitoring for POA 
projects. These recommendations included:
     A minimum of three PSOs at an observation station is 
necessary to prevent fatigue and increase accuracy of detecting marine 
mammals, especially for large-radius zones. When using three PSOs, one 
PSO is observing, one PSO is recording data (and observing when there 
are no data to record), and the third PSO is resting. A fourth PSO 
allows the scanning of a 90-degree arc, instead of a 180-degree arc, 
increasing scan intensity and the likelihood of detecting marine 
mammals. Thirty to 60 minute rotations work well with this schedule.
     Communications between the pile driving/construction 
contractor and the PSOs should take place between one dedicated point 
of contact, or Lead PSO, for each shift.
     Each observation station should employ a pair of 25-power 
binoculars as they were superior to the 7- and 10- power binoculars at 
detecting and identifying marine mammals at greater distances.
     Electronic data collection methods should be considered. 
Tablet applications and other technological advances make it possible 
to collect data quickly and accurately. A theodolite can be plugged 
into the device and marine mammal locations can be calculated on the 
spot, minimizing uncertainty. Data can be downloaded throughout the day 
to a database, eliminating the need for data entry by hand, and 
allowing quicker data assessment.
     Hard copy maps with pre-established grid-cells and 
harassment zones specific to the pile location being driven were 
invaluable. These maps allowed for immediate, accurate and consistent 
identification of marine mammal locations relative to the harassment 
zones, regardless of observation station.
    The POA's IHA application addresses the majority of these 
recommendations in its Marine Mammal Monitoring Plan (Appendix A in 
POA's application) and NMFS has included additional measures here. NMFS 
is requiring four monitoring stations, and requiring at least three 
PSOs (two on-watch and one to record data) to be positioned at the 
northern and southern stations while two PSOs will be on-watch at the 
PCT (i.e., pile driving) station. Each station will be equipped with 
several pieces of equipment (see section 2.4 in Appendix A of POA's 
application), including 25x binoculars and a range finders, as 
recommended above. One station will have a theodolite. PSOs may observe 
for no more than 4 hours at time and no more than 12 hours per day. The 
POA will submit all PSO CVs to NMFS prior to a PSO working on this 
project. In addition, if POA is conducting non-PCT-related in-water 
work that includes PSOs, the PCT PSOs must be in real-time contact with 
those PSOs, and both sets of PSOs must share all information regarding 
marine mammal sightings with each other.
    To improve beluga whale detection, NMFS has worked with the POA to 
include PSO stations in different locations than the three stations 
originally proposed by the POA, which were all on POA property. In 
addition, since publication of the notice of proposed IHAs, the POA has 
included a fourth monitoring station. One PSO station will be located 
at the PCT pile driving site. One station will be at Port Woronzof or a 
similar location, rather than on the POA property, to maximize beluga 
whale detection outside of Knik Arm and the mouth of Knik Arm. PSOs at 
this location will have unencumbered views of the entrance to Knik Arm 
and can provide information on beluga whale group dynamics (e.g., group 
size, demographics, etc) and behavior of animals approaching Knik Arm 
in the absence of and during pile driving. We also considered moving a 
station from the POA property to Port MacKenzie for an improved view of 
beluga whales moving from north to south within Knik Arm. However, Port 
MacKenzie is not an available option due to logistical reasons; 
therefore, the northern station will be located on POA property. A 
fourth PSO station will be located at Ship Creek.
    For both Phase 1 and Phase 2, NMFS is requiring the POA to submit 
interim weekly and monthly monitoring reports (that include data 
sheets) during the

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PCT construction season. These reports must include a summary of marine 
mammal species and behavioral observations, pile driving shutdowns or 
delays, and pile driving work completed. A final end-of season report 
will be submitted to NMFS within 90 days following pile driving. The 
report must include: Dates and times (begin and end) of all marine 
mammal monitoring; a description of daily construction activities, 
weather parameters and water conditions during each monitoring period; 
number of marine mammals observed, by species, distances and bearings 
of each marine mammal observed to the pile being driven or removed, age 
and sex class, if possible; number of individuals of each species 
(differentiated by month as appropriate) detected within the monitoring 
zone, and estimates of number of marine mammals taken, by species (a 
correction factor may be applied); description of mitigation 
implemented, and description of attempts to distinguish between the 
number of individual animals taken and the number of incidences of 
take. In addition, any acoustic data and analysis collected throughout 
the year will also be made available to NMFS in the form of an interim 
report within 10 days of data collection for 24 to 48-in piles and 72 
hours for 144-in piles. The POA will also submit draft and final 
reports within 60 days of the conclusion of acoustic monitoring each 
season. Reported metrics will include, but are not limited to, 
monitoring methods, mean, median, and peak sound source levels (dB re: 
1[micro]Pa): cumulative sound exposure level (SELcum), peak sound 
pressure level (SPLpeak), root mean square sound pressure level 
(SPLrms), and single-strike sound exposure level (SELs-s), spectra, and 
amount of pile strikes or vibratory hammer duration. In addition, 
during PCT hydroacoustic monitoring, allin-water work occurring in the 
area (e.g., dredging, other in-water work at the POA, vessel transit) 
must be documented (e.g., type of activity, location relative to 
recordings, date/time) and reported in the acoustic monitoring report.
    NMFS has also included reporting requirements for unanticipated 
situations. In the unanticipated event that the specified activity 
clearly causes the take of a marine mammal in a manner prohibited by 
this IHA, such as serious injury, or mortality, POA must immediately 
cease the specified activities and report the incident to NMFS. In the 
event POA discovers an injured or dead marine mammal, and the lead 
observer determines that the cause of the injury or death is unknown 
and the death is relatively recent (e.g., in less than a moderate state 
of decomposition), POA must immediately report the incident to the 
Office of Protected Resources, NMFS, and the Alaska Region Stranding 
Coordinator, NMFS. In addition, in the event that POA discovers an 
injured or dead marine mammal, and the lead observer determines that 
the injury or death is not associated with or related to the specified 
activities (e.g., previously wounded animal, carcass with moderate to 
advanced decomposition, or scavenger damage), POA must report the 
incident to the Office of Protected Resources, NMFS, and the Alaska 
Region Stranding Coordinator, NMFS, within 24 hours of the discovery.

Negligible Impact Analyses and Determinations

    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). Below we present our analysis for each IHA.
    To avoid repetition, the discussion below applies to all the 
species listed in Table 11 for which we authorized take, other than 
CIBWs, for each IHA (i.e., the POA's planned activities for Phase 1 and 
Phase 2 activities), as the anticipated effects of both Phase 1 and 
Phase 2 activities on marine mammals are expected to be relatively 
similar in nature. For CIBWs, there are meaningful differences in 
anticipated individual responses to activities, impact of expected take 
on CIBWs, or impacts on habitat; therefore, we provide a supplemental 
analysis for CIBWs, independent of the other species for which we 
authorize take.
    NMFS has identified key factors which may be employed to assess the 
level of analysis necessary to conclude whether potential impacts 
associated with a specified activity should be considered negligible. 
These include (but are not limited to) the type and magnitude of 
taking, the amount and importance of the available habitat for the 
species or stock that is affected, the duration of the anticipated 
effect to the species or stock, and the status of the species or stock. 
The following factors support negligible impact determinations for the 
affected stocks of humpback whales, killer whales, harbor porpoise, 
harbor seals, and Steller sea lions. Some of these also apply to CIBWs; 
however, a more detailed analysis for CIBWs is provided below.
     No takes by mortality or serious injury are anticipated or 
authorized;
     The number of total takes (by Level A and Level B 
harassment) are less than 3 percent of the best available abundance 
estimates for all stocks;
     Take would not occur in places and/or times where take 
would be more likely to accrue to impacts on reproduction or survival, 
such as within ESA-designated or proposed critical habitat, 
biologically important areas (BIA), or other habitats critical to 
recruitment or survival (e.g., rookery);
     Take would occur over a short timeframe, being limited to 
the short duration a marine mammal would likely be present within a 
Level B harassment zone during pile driving;
     Any impacts to marine mammal habitat from pile driving are 
temporary and minimal; and
     Take would only occur within upper Cook Inlet--a limited, 
confined area of any given stock's home range.
    For CIBWs, we further discuss our negligible impact findings in the 
context of potential impacts to this endangered stock. As described in 
the Recovery Plan for the Cook Inlet Beluga Whale (NMFS, 2016), NMFS 
determined the following physical or biological features are essential 
to the conservation of this species: (1) Intertidal and subtidal waters 
of Cook Inlet with depths less than 30 feet mean lower low water (9.1 
m) and within 5 mi (8 km) of high and

[[Page 19322]]

medium flow anadromous fish streams; (2) Primary prey species 
consisting of four species of Pacific salmon (Chinook, sockeye, chum, 
and coho), Pacific eulachon, Pacific cod, walleye pollock, saffron cod, 
and yellowfin sole, (3) Waters free of toxins or other agents of a type 
and amount harmful to CI beluga whales, (4) Unrestricted passage within 
or between the critical habitat areas, and (5) Waters with in-water 
noise below levels resulting in the abandonment of critical habitat 
areas by CI beluga whales. The PCT would not impact essential features 
1-3 listed above. All construction would be done in a manner 
implementing best management practices to preserve water quality and no 
work would occur around creek mouths or river systems leading to prey 
abundance reductions. In addition, no physical structures would 
restrict passage; however, impacts to the acoustic habitat are of 
concern. Previous marine mammal monitoring data at the POA demonstrate 
beluga whales indeed pass by the POA during pile driving. As described 
above, there was no significant difference in beluga sighting rate with 
and in the absence of pile driving (Kendell and Cornick, 2015). 
However, beluga whales do swim faster and in tighter formation in the 
presence of pile driving (Kendell and Cornick, 2015).
    During review of the POA's application, NMFS was concerned that 
exposure to pile driving at the PCT could result in beluga whales 
avoiding Knik Arm and thereby not accessing the productive foraging 
grounds north of POA such as Eagle River flats based on the proposed 
project and mitigation measures--thus, impacting essential feature 
number 5 above. Although the data previously presented demonstrate 
whales are not abandoning the area (i.e., no significant difference in 
sighting rate with and without pile driving), we considered the results 
of a recent expert elicitation (EE) at a 2016 workshop, which predicted 
the impacts of noise on CIBW survival and reproduction given lost 
foraging opportunities, to inform our assessment of impacts on this 
stock. The 2016 EE workshop used conceptual models of an interim 
population consequences of disturbance (PCoD) for marine mammals (NRC 
2005; New et al. 2014, Tollit et al., 2016) to help in understanding 
how noise-related stressors might affect vital rates (survival, birth 
rate and growth) for CIBW (King et al. 2015). NMFS (2015, section 
IX.D--CI Beluga Hearing, Vocalization, and Noise Supplement) suggests 
that the main direct effects of noise on CIBW are likely to be through 
masking of vocalizations used for communication and prey location, and 
habitat degradation. The 2016 workshop on beluga whales was 
specifically designed to provide regulators with a tool to help 
understand whether chronic and acute anthropogenic noise from various 
sources and projects are likely to be limiting recovery of the CIBW 
population. The full report can be found at https://www.smruconsulting.com/publications/ and we provide a summary of the 
expert elicitation portion of the workshop here.
    For each of the noise effect mechanisms chosen for expert 
elicitation, the experts provided a set of parameters and values that 
determined the forms of a relationship between the number of days of 
disturbance a female CIBW experiences in a particular period and the 
effect of that disturbance on her energy reserves. Examples included 
the number of days of disturbance during the period April, May and June 
that would be predicted to reduce the energy reserves of a pregnant 
CIBW to such a level that she is certain to terminate the pregnancy or 
abandon the calf soon after birth, the number of days of disturbance in 
the period April-September required to reduce the energy reserves of a 
lactating CIBW to a level where she is certain to abandon her calf, and 
the number of days of disturbance where a female fails to gain 
sufficient energy by the end of summer to maintain themselves and their 
calves during the subsequent winter. Overall, median values ranged from 
16 to 69 days of disturbance depending on the question. However, for 
this elicitation, a ``day of disturbance'' was defined as any day on 
which an animal loses the ability to forage for at least one tidal 
cycle (i.e., it forgoes 50-100% of its energy intake on that day). 
Therefore, disturbance in this context is not equivalent to Level B 
harassment but would represent increased severity compared with Level B 
harassment as defined in the MMPA. The mitigation measures NMFS has 
prescribed for the PCT project are designed to avoid the potential that 
any animal would lose the ability to forage for one or more tidal 
cycles. While Level B harassment (behavioral disturbance) is 
authorized, our mitigation measures would limit the severity of the 
effects of that Level B harassment to behavioral changes such as 
increased swim speeds, tighter group formations, and cessation of 
vocalizations, not the loss of foraging capabilities. Regardless, this 
elicitation recognized that pregnant or lactating females and calves 
are inherently more at risk than other animals, such as males. NMFS 
first considered proposing the POA shutdown based on more vulnerable 
life stages (e.g., calf presence) but ultimately determined all beluga 
whales warranted pile driving shutdown to be protective of potential 
vulnerable life stages, such as pregnancy, that could not be determined 
from observations, and to avoid more severe behavioral reaction.
    Monitoring data from the POA suggest pile driving does not 
discourage beluga whales from entering Knik Arm and travelling to 
critical foraging grounds such as those around Eagle Bay. As previously 
described, sighting rates were not different in the presence or absence 
of pile driving. This is not surprising as food is a strong motivation 
for marine mammals. As described in Forney et al. (2017), animals 
typically favor particular areas because of their importance for 
survival (e.g. feeding or breeding), and leaving may have significant 
costs to fitness (reduced foraging success, increased predation risk, 
increased exposure to other anthropogenic threats). Consequently, 
animals may be highly motivated to maintain foraging behavior in 
historical foraging areas despite negative impacts (e.g., Rolland et 
al. 2012). Previous monitoring data indicates beluga whales are 
responding to pile driving noise but not through abandonment of 
critical habitat, including primary foraging areas north of the port. 
Instead, they travel faster past the POA, more quietly, and in tighter 
groups (which may be linked to the decreased communication patterns). 
This traveling behavior past the POA has also been verified by acoustic 
monitoring. Castellote et al. (2020) found low echolocation detection 
rates in lower Knik Arm indicating belugas moved through that area 
relatively quickly when entering or exiting the Arm. We anticipate 
these behaviors to continue, and do not believe exposure to elevated 
noise levels during transit past the POA has adverse effects on 
reproduction or survival as the whales continue to access critical 
foraging grounds north of the POA, and tight associations help to 
mitigate the potential for any contraction of communication space for a 
group. Finally, as described previously, both telemetry (tagging) and 
acoustic data suggest beluga whales likely stay in upper Knik Arm for 
several days or weeks before exiting Knik Arm. Specifically, a beluga 
instrumented with a satellite link time/depth recorder entered Knik Arm 
on August 18th and remained in Eagle Bay until September 12th (Ferrero 
et al. 2000). Further, a recent detailed re-analysis of the satellite 
telemetry data confirms how

[[Page 19323]]

several tagged whales exhibited this same movement pattern: whales 
entered Knik Arm and remained there for several days before exiting 
through lower Knik Arm (Shelden et al. 2018). This longer-term use of 
upper Knik Arm would avoid repetitive exposures from pile driving 
noise.
    NMFS has prescribed mitigation measures beyond those proposed by 
the POA in the IHA application, specifically, not commencing pile 
driving if beluga whales are observed within Knik Arm or within 1 km of 
the mouth of Knik Arm, shutting down pile driving should a beluga whale 
approach or enter the Level B harassment zone, stationing PSOs at Point 
Woronzof and Ship Creek, and not vibratory pile driving 144-in piles 
during August (peak beluga season). These measures are designed to 
ensure beluga whales will not abandon critical habitat and exposure to 
pile driving noise will not result in adverse impacts on the 
reproduction or survival of any individuals. The location of PSOs at 
Point Woronzof allows for detection of beluga whales at much farther 
distances than previous years and behavioral observations prior to 
whales entering Knik Arm. Although NMFS does not anticipate beluga 
whales would abandon entering Knik Arm in the presence of pile driving 
with the required mitigation measures, these PSOs will be integral to 
identifying if belugas are potentially altering pathways they would 
otherwise take in the absence of pile driving. Because the POA is 
submitting weekly and monthly reports, NMFS will be able to regularly 
evaluate if the impacts of the project are having a greater than 
anticipated impact on beluga whales. If we find the project is having a 
greater than negligible impact on marine mammals, the IHA may be 
modified or revoked. Finally, take by mortality, serious injury, or 
Level A harassment of CIBWs is not anticipated or authorized.
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from the 
activities analyzed under each of these two separate IHAs are not 
expected to adversely affect CIBWs through effects on annual rates of 
recruitment or survival:
     No mortality or serious injury is anticipated or 
authorized;
     Area of exposure would be limited to travel corridors. 
Data demonstrates Level B harassment manifests as increased swim speeds 
past the POA and tight group formations and not through habitat 
abandonment;
     No critical foraging grounds (e.g. Eagle Bay, Eagle River, 
Susitna Delta) would be impacted by pile driving; and
     While animals could be harassed more than once, exposures 
are not likely to exceed more than a few per year for any given 
individual and are not expected to occur on sequential days; thereby, 
decreasing the likelihood of physiological impacts caused by chronic 
stress or masking.
    We also considered our negligible impact analysis with respect to 
NMFS' technical report released in January 2020 regarding the abundance 
and status of CIBWs (Sheldon and Wade, 2019). As described in the 
marine mammal section, new analysis indicates the CIBW stock is smaller 
and declining faster than previously recognized. While this is 
concerning, NMFS continues to believe the taking authorized (allowed 
for in the cases where shutdowns cannot occur in time to avoid Level B 
harassment take) will have a negligible impact. The monitoring measures 
(four stations each equipped with two PSOs simultaneously on watch at 
each station) are extensive, such that we find it unlikely whales would 
go undetected. The mitigation measures reduce noise entering the water 
column (a benefit for all marine mammals) through the use of a confined 
bubble curtain and noise levels would be verified upon the onset of 
pile driving to verify estimated harassment zones. Further, the 
exposure risk to CIBWs is greatly minimized through the incorporation 
of in-bound and out-bound whale pre-pile driving clearance zones. 
Finally, should pile driving be occurring at the same time a whale is 
detected, pile driving would shut down prior to its entering the Level 
B harassment zone. All these measures, as well as other required 
measures such as soft-starts, greatly reduce the risk of animals not 
accessing important foraging areas north of the POA, which could result 
in impacts to annual rates of recruitment or survival. For these 
reasons, the new status of CIBWs does not ultimately change our 
findings with respect to the specified activities.
    Phase 1 IHA--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 required 
monitoring and mitigation measures, we find that the total marine 
mammal take from the POA's construction activities in Phase 1 will have 
a negligible impact on the affected marine mammal species or stocks.
    Phase 2 IHA--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 required 
monitoring and mitigation measures, we find that the total marine 
mammal take from the POA's construction activities in Phase 2 will have 
a negligible impact on the 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 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. Additionally, other qualitative 
factors may be considered in the analysis, such as the temporal or 
spatial scale of the activities.
    For all non-CIBW stocks, for both the Phase 1 and Phase 2 IHAs, the 
amount of taking is less than one-third of the best available 
population abundance estimate (in fact it is less than 4 percent for 
all stocks considered here). Further, the amount of take authorized 
likely represents smaller numbers of individual harbor seals and 
Steller sea lions. Harbor seals tend to concentrate near Ship Creek and 
have small home ranges; therefore, the amount of take authorized likely 
represents repeat exposures to the same animals. Previous Steller sea 
lion sightings identified that if a Steller sea lion is within Knik 
Arm, it is likely lingering to forage on salmon or eulachon runs and 
may be present for several days.
    We provide additional information with respect to CIBW. They are 
known to enter Knik Arm and then exit after several days of remaining 
within Knik Arm. There is potential an individual is taken on both 
ingress and egress; however, due to the mitigation measures 
(essentially takes are for animals where pile driving cannot be shut 
down before exposure), the circumstances would have to be such that 
pile driving is occurring while the whale is both entering and exiting 
Knik Arm and that the animal is missed or taken due to logistical 
constraints of shutting down pile driving immediately in both cases.
    Phase 1 IHA--Based on the analysis contained herein of the likely 
effects of the specified activity in Phase 1 on marine mammals and 
their habitat, and taking into consideration the

[[Page 19324]]

implementation of the mitigation and monitoring measures, we find that 
small numbers of marine mammals will be taken relative to the 
populations of the affected species or stocks.
    Phase 2 IHA--Based on the analysis contained herein of the likely 
effects of the specified activity in Phase 2 on marine mammals and 
their habitat, and taking into consideration the implementation of the 
mitigation and monitoring measures, we find that small numbers of 
marine mammals will be taken relative to the populations 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.
    No subsistence use of CIBWs occurs and subsistence harvest of other 
marine mammals in upper Cook Inlet is limited to harbor seals. Steller 
sea lions are rare in upper Cook Inlet; therefore, subsistence use of 
this species is not common. However, Steller sea lions are taken for 
subsistence use in lower Cook Inlet. In 2013 and 2014, the ADF&G 
conducted studies to document the harvest and use of wild resources by 
residents of four tribal communities in Cook Inlet: Tyonek, Nanwalek, 
Port Graham, and Seldovia (Jones and Kostick 2016). Tyonek is the 
community in closest proximity to Knik Arm while the other communities 
are located lower in Cook Inlet. The only marine mammal species taken 
by the Tyonek community was harbor seals (from the McArthur River Flats 
north to the Beluga River (Jones et al. 2015)- south of Knik Arm) while 
communities lower in the inlet relied on harbor seals, Steller sea 
lions and sea otters (we note the sea otter is under the jurisdiction 
of the USFWS; therefore, it is not a part of our analysis).
    The potential impacts from harassment on stocks that are harvested 
in Cook Inlet would be limited to minor behavioral changes (e.g., 
increased swim speeds, changes in dive time, temporary avoidance near 
the POA, etc.) within the vicinity of the POA. Some PTS may occur; 
however, the shift is likely to be slight due to the implementation of 
mitigation measures (e.g., shutdown zones) and the shift would be 
limited to lower pile driving frequencies which are on the lower end of 
phocid and otariid hearing ranges. In summary, any impacts to harbor 
seals would be limited to those seals within Knik Arm (outside of any 
hunting area) and the very few takes of Steller sea lions in Knik Arm 
would be far removed in time and space from any hunting in lower Cook 
Inlet.
    Finally, we have not received any communication from Alaska Natives 
that this project raises concern regarding their subsistence use. The 
POA alerted 14 tribal organizations and communities to the notice of 
proposed IHAs. No tribes commented on or expressed concern over 
subsistence use during the public comment period for the proposed IHAs.
    For all these reasons, relevant to both the Phase 1 and Phase 2 
IHAs, NMFS has determined that the total taking of affected species or 
stocks would not have an unmitigable adverse impact on the availability 
of such species or stocks for taking for subsistence purposes.

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 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 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, in this case with the Alaska Region Protected 
Resources Division (AKR), whenever we propose to authorize take for 
endangered or threatened species.
    On November 18, 2019, NMFS requested consultation on the issuance 
of two successive IHAs to the POA authorizing the take of humpback 
whales (Mexico DPS, Western North Pacific DPS), wDPS Steller sea lions, 
and CIBWs. On March 23, 2020, NMFS AKR released a Biological Opinion 
concluding the proposed action would not jeopardize the continued 
existence of the aforementioned species and would not destroy or 
adversely modify critical habitat.

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 
incidental harassment authorization) with respect to potential impacts 
on the human environment.
    NMFS prepared a draft EA to consider the environmental impacts 
associated with the issuance of two IHAs which was made available to 
the public during the public comment period on the proposed IHAs. NMFS' 
final EA considered comments submitted during the public comment period 
and found that authorizing take of marine mammals by issuing the IHAs 
would not result in significant direct, indirect, or cumulative impacts 
to the human environment. Accordingly, NMFS determined that issuance of 
the IHAs to the POA would not significantly impact the quality of the 
human environment and signed a Finding of No Significant Impact 
(FONSI). NMFS' Final EA and FONSI are available online at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.

Authorization

    As a result of these determinations, NMFS has issued the two 
requested IHAs to the POA for the PCT Project, provided the previously 
mentioned mitigation, monitoring, and reporting requirements are 
incorporated. A copy of the final IHAs can be found at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.

    Dated: April 1, 2020.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2020-07106 Filed 4-3-20; 8:45 am]
 BILLING CODE 3510-22-P