[Federal Register Volume 86, Number 170 (Tuesday, September 7, 2021)]
[Notices]
[Pages 50057-50079]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-19187]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XB329]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Relocation of the Port of 
Alaska's South Floating Dock, Anchorage, Alaska

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

ACTION: Notice; issuance of an incidental harassment authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is given that 
NMFS has issued an incidental harassment authorization (IHA) to the 
Port of Alaska (POA) to incidentally harass, by Level B harassment and 
Level A harassment, marine mammals during pile driving associated with 
the relocation of the POA's South Floating Dock (SFD) within Knik Arm, 
in upper Cook Inlet, Alaska.

DATES: This Authorization is effective from August 27, 2021 through 
August 26, 2022.

FOR FURTHER INFORMATION CONTACT: Reny Tyson Moore, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. In case of problems accessing these 
documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are issued or, if the taking is limited to harassment, a notice of an 
incidental take authorization may be provided to the public for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of the species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of the takings are set forth. The definitions 
of all applicable MMPA statutory terms cited above are included in the 
relevant sections below.

Summary of Request

    On October 2, 2020, NMFS received a request from the POA for an IHA 
to take marine mammals incidental to pile driving associated with the 
relocation of the SFD within Knik Arm in upper Cook Inlet, Alaska. 
Revised applications were submitted by the POA on December 15, 2020, 
January 29, 2021, February 5, 2021, and March 5, 2021 that addressed 
comments provided by NMFS. The application was deemed adequate and 
complete on March 17, 2021. Additional revised applications were 
submitted on March 26, 2021, which addressed typos, and May 14 2021, 
which adjusted transmission loss rates based on the final Petroleum 
Cement Terminal (PCT) Hydroacoustic Monitoring Report for activities 
completed in 2020 (Reyff et al., 2021). The POA requested, and NMFS has 
authorized, take of a small number of six species of marine mammals by 
Level B harassment and Level A harassment. Neither the POA nor NMFS 
expects serious injury or mortality to result from this activity, nor 
did NMFS authorize any. Therefore, an IHA is appropriate.
    NMFS previously issued IHAs to the POA for pile driving (73 FR 
41318, July 18, 2008; 74 FR 35136, July 20, 2009; 81 FR 15048, March 
21, 2016; and 85 FR 19294, April 06, 2020). The POA has complied with 
the requirements (e.g., mitigation, monitoring, and reporting) of all 
previous IHAs and information regarding their monitoring results may be 
found in the Effects of the Specified Activity on Marine Mammals and 
their Habitat and Estimated Take sections.

Description of Specified Activity

    The POA is modernizing its marine terminals through the Port of 
Alaska Modernization Program (PAMP). One of

[[Page 50058]]

the first priorities of the PAMP is to replace the existing Petroleum 
Oil Lubricants Terminal with a new PCT. For the PCT project to advance, 
the existing SFD, a small multipurpose floating dock important for 
staging, mooring, and docking of small vessels, such as first responder 
(e.g., Anchorage Fire Department, U.S. Coast Guard) rescue craft, small 
work skiffs, and occasionally tug boats, must be relocated south of the 
PCT. The existing location of SFD will not allow docking operations at 
SFD once the PCT is constructed due to the close proximity of one of 
the PCT mooring dolphins (a structure for berthing and mooring of 
vessels). Relocation of the SFD will include the removal of the 
existing access trestle and gangway, and vibratory or impact 
installation of twelve permanent 36-inch steel pipe piles: Ten vertical 
and two battered (an impact hammer may be required if a pile encounters 
refusal and cannot be advanced to the necessary tip elevation with the 
vibratory hammer; Table 1). Construction of the SFD will also require 
the installation and vibratory removal of up to six 24- or 36-inch 
temporary template piles (Table 1). In-water pile installation and 
removal associated with SFD removal and construction is anticipated to 
take place on up to 24 nonconsecutive days between the date of issuance 
and November 2021. A detailed description of the POA's SFD activities 
is provided in the Federal Register notice of the proposed IHA (86 FR 
31870, June 15, 2021). Since that time, no changes have been made to 
the planned relocation and construction activities, other than project 
timing due to delays in construction scheduling and the timing of the 
issuance of the IHA (The project was originally scheduled to occur on 
up to 24 nonconsecutive days between April and November 2021 but is now 
scheduled to occur between the date of issuance and November 2021). 
Therefore, a detailed description is not provided here. Please refer to 
that Federal Register notice for the description of the specific 
activity.

                                                      Table 1--Pile Details and Estimated Effort Required for Pile Installation and Removal
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                                                                                                                              Potential    Production rate (piles/
                                                                                                                                impact               day)
                                                                                       Vibratory                             strikes per ---------------------------
                                                        Number of    Number of       installation        Vibratory removal     pile, if                                  Days of       Days of
       Pipe pile diameter               Feature        plumb piles    battered     duration per pile     duration per pile    needed (up                              installation     removal
                                                                       piles           (minutes)             (minutes)       to 5 piles;  Installation    Removal
                                                                                                                               one pile
                                                                                                                               per day)
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36-inch.........................  Floating Dock......            6            2  45..................  n/a.................        1,000           1-3          n/a            4-12          n/a
                                  Gangway............            4            0                        n/a.................        1,000           1-3          n/a                          n/a
24- or 36-inch..................  Temporary Template             6            0  45..................  75..................        1,000           1-2          1-3             3-6          2-6
                                   Piles.
                                                      ------------------------------------------------------------------------------------------------------------------------------------------
    Project Totals..............  ...................           16            2  13.5 hours..........  7.5 hours...........  ...........  ............  ...........            7-18          2-6
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    Mitigation, monitoring, and reporting measures are described in 
detail later in this document (please see Mitigation and Monitoring and 
Reporting).

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to the POA was published 
in the Federal Register on June 15, 2021 (86 FR 31870). That notice 
described, in detail, POA's activity, the marine mammal species that 
may be affected by the activity, and the anticipated effects on marine 
mammals. During the 30-day public comment period, NMFS received 
comments from one private citizen and from the Defenders of Wildlife. A 
summary of the commenters' recommendations as well as NMFS' responses 
is below. Please see the Defender of Wildlife's letter for full details 
regarding their recommendations and rationale. The letter is available 
online at: https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.
    Comment 1: The Defenders of Wildlife raised concerns about the 
noise levels in Cook Inlet and the status of the Cook Inlet beluga 
whales (CIBWs). They commended our proposed measure to not allow 
battered piles to be driven during August and September but asserted 
that no pile driving activities associated with the project should be 
authorized in August or September in order for NMFS to justify our 
negligible impact and least practicable adverse impact findings.
    Response: The MMPA requires that an IHA include measures that will 
affect the least practicable adverse impact on the affected species and 
stock and, which may include conditions for the construction activities 
that avoid and/or minimize adverse effects on CIBWs in and around the 
project area, where practicable. Mitigation and monitoring requirements 
have been included in the IHA to ensure the least practicable adverse 
impact on CIBWs and other marine mammal species in the project area. 
These requirements include the use of a bubble curtain system for the 
installation and removal of all plumb piles, the implementation of a 
robust marine mammal monitoring program, which will consist of eleven 
Protected Species Observers (PSOs) working from four unique locations 
spread over a 9 km-long stretch of surrounding coastline, and shutdown 
measures when CIBWs are observed approaching or entering the mouth of 
Knit Arm or the Level B harassment zone. These measures are designed to 
ensure CIBWs will not abandon critical habitat and that exposure to 
pile driving noise will not result in adverse impacts on the 
reproduction or survival of any individuals. These mitigation and 
monitoring measures are modeled after the measures included in the 
final IHAs for Phase 1 and Phase 2 PCT construction (85 FR 19294, April 
6, 2020), which appeared to be effective at avoiding and minimizing 
impacts to marine mammals in the project area, as evidenced by 
observations made during PCT Phase 1 construction monitoring

[[Page 50059]]

(61 North Environmental, 2021) as described below.
    The commenters expressed concern that permitting the project as 
proposed will create and/or exacerbate a condition where it is not 
possible for any beluga whale to transit past the project area to or 
from critical foraging and nursing habitat in Knik Arm. This concern is 
not supported by observations made of CIBWs during pile driving 
activities at the POA (e.g., Kendall and Cornick, 2015, 61 North 
Environmental, 2021). As described in the Negligible Impact Analyses 
and Determinations sections of the Federal Notices of the proposed IHA 
(86 FR 31870, June 15, 2021) and this final IHA, monitoring data from 
the POA suggest pile driving does not discourage CIBWs from entering 
and transiting through Knik Arm. For example, CIBWs continued to use 
Knit Arm during the duration of the PCT Phase 1 construction project in 
2020 and frequently transited past the project area to or from critical 
foraging grounds and possible nursing habitat such as those around 
Eagle Bay (61 North Environmental, 2021). Sighting rates have also not 
been different in the presence or absence of pile driving (Kendall and 
Cornick, 2015). While some individuals have demonstrated responses to 
pile driving activities, CIBWs were more likely to display no reaction 
or to continue to move towards the POA during pile installation and 
removal during PCT Phase 1 construction monitoring (61 North 
Environmental, 2021). In situations during which CIBWs have shown a 
possible reaction to pile driving, observed behavioral responses have 
been limited to increased travel speeds and tighter group formations 
(e.g., Kendall and Cornick, 2015, 61 North Environmental, 2021); CIBWs 
did not abandon critical habitat and actively transited past the 
project area. This traveling behavior past the POA has also been 
verified by acoustic monitoring (e.g., Castellote et al., 2020). We 
anticipate that disturbance to CIBWs would manifest in the same manner 
when they are exposed to noise during the SFD project: Whales will not 
demonstrate a response or they will move quickly and silently through 
the area in more cohesive groups. We further do not believe exposure to 
elevated noise levels during transit past the POA will have adverse 
effects on reproduction or survival as the whales continue to access 
critical foraging grounds north of the POA, and that tight associations 
may help to mitigate the potential for any contraction of communication 
space for a group.
    The Defenders of Wildlife were also concerned that low levels of 
noise may have biological impacts by ``masking'' important 
communication signals, influencing communication behaviors and 
disrupting foraging for Cook Inlet beluga whales and that masking may 
not be detected by visible observations. While both masking of 
communication signals and temporary threshold shifts (TTS) could 
potentially occur, noise impacts will occur over a short time (i.e., up 
to 21 total hours spread over nine to 24 non-consecutive days), and 
would be limited to the short duration a marine mammal would likely be 
present within a Level B harassment zone during pile driving. This 
short timeframe minimizes the probability of multiple exposures on 
individuals, and any repeated exposures that do occur are not expected 
to occur on sequential days, decreasing the likelihood of physiological 
impacts caused by chronic stress or sustained energetic impacts that 
might affect survival or reproductive success. We agree that masking of 
important communication signals may not be detected by visible 
observations, and we discuss the implications of masking and TTS in the 
Federal Notice of the proposed IHA (86 FR 31870, June 15, 2021). NMFS 
has determined that the temporary masking of signals that could result 
from the short-term, intermittent pile driving activities would not 
affect the annual rates of recruitment or survival for any marine 
mammal species present in the project area and, therefore, do not 
affect our negligible impact determination. Further, the required 
mitigation and monitoring measures included in this IHA are designed to 
minimize to the least practicable extent the impacts that noise from 
the POA's pile driving activities will have on the health and behavior 
of marine mammals in the project area, including masking of their 
signals.
    The commenters also argued that the size of the (additive) 
ensonified area is less important than the amount of (additive) noise 
in the areas that belugas will likely use. While we acknowledge that 
the POA's activities will add noise into the marine environment that 
CIBWs use, this small, short-term project is not expected to impact the 
reproduction or survival of any individual CIBWs or other marine mammal 
species in the project area.
    The commenters recommended that we assess alternatives for pile 
driving in August or September. Restricting all pile installation and 
removal in August and September as recommended is not practicable for 
the POA to implement. It is necessary for construction of the SFD to 
proceed in August and/or September for installation of at least the 
plumb (vertical) piles in order to allow for completion of the SFD 
project during the 2021 construction season. Pile installation for the 
new SFD must begin before the onset of poor fall weather, when snow, 
ice, and limited daylight hours can slow the pace of construction or 
prevent timely completion of required tasks. A delay in timing of 
construction, such as a prohibition on all pile installation in August 
and September, could extend construction into the spring of 2022 when 
no in-water construction work is currently scheduled. This delay 
results in the need for remobilization of pile installation 
construction equipment, and costly consequences for the POA. In 
addition, it would delay operation of the SFD to 2022. The SFD is a key 
facility for the Municipality of Anchorage and provides staging, 
mooring, and docking of small vessels, such as first responder (e.g., 
Anchorage Fire Department, U.S. Coast Guard) rescue craft; small work 
skiffs; and occasionally tug boats, in an area close to the daily 
operations at the Port. The SFD also supports dredging and bathymetric 
survey vessels and other municipal and port operations. Upper Cook 
Inlet near Anchorage exhibits the largest tide range in the U.S. and 
one of the largest tide ranges in the world, with an average daily 
difference between high and low tide of 8 meters (26.2 feet) and an 
extreme difference of up to 12.5 meters (41 feet) (NOAA 2015). The 
ability of first responders to conduct response operations during low 
tide stages requires access to the SFD, as the waterline is 
inaccessible for vessels at the nearby Anchorage public boat launch at 
Ship Creek during low waters. Thus, it is imperative that construction 
of the SFD proceed as proposed given it is required to provide 
continuous, timely, and safe access for rescue personnel and vessels in 
the northern portion of Cook Inlet. Finally, a delay leading to 
construction in 2022 could result in additional harassment exposure to 
marine mammals next year. The POA has indicated that it is practicable 
that they not install the two permanent battered piles, which have 
Level B harassment distances that are approximately two or more times 
greater than all other plumb piles, in August and September. This 
requirement will both minimize the size of the ensonified area during 
the peak CIWB season in the project area and maximize the probability 
of CIBW detections by PSOs

[[Page 50060]]

and necessary shutdowns during pile driving activities.
    For these reasons stated above, we disagree that our current 
analysis undermines both the negligible impact conclusion and the least 
practicable impact. In consideration of the likely effects of the 
activity on marine mammals absent mitigation, potential unintended 
consequences of the measures as proposed by the commenters, and 
practicability of the recommended measures for the applicant, NMFS has 
determined that restricting construction as recommended is not 
warranted or practicable in this case and that the authorized takes 
will have a negligible impact on CIBWs and the other affected marine 
mammal species or stocks.
    Comment 2: The Defenders of Wildlife assert that our negligible 
impact determination is flawed because we incorrectly indicated that 
area of exposure would be limited to travel corridors and that no 
critical foraging grounds would be impacted by pile driving.
    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 on 
CIBWs and other marine mammals in the project area. We acknowledged 
that CIBWs have been occasionally documented to forage around Ship 
Creek in the Federal Notice of the proposed IHA (86 FR 31870, June, 15, 
2021) but that they may choose to move past the POA to other, 
potentially richer, feeding areas further into Knik Arm (e.g., Six Mile 
Creek, Eagle River, Eklutna River) which contain predictable salmon 
runs (ADF&G, 2010) during pile driving activities.
    During PCT Phase 1 construction monitoring (61 North Environmental, 
2021) observations of CIBWs near Ship Creek involved animals transiting 
past or milling near or in front of the creek. While CIBWs may forage 
in or near Ship Creek, there are other known foraging grounds in the 
project area that CIBWs can transit to during pile driving activities. 
In addition, prey for CIBWs are mobile and broadly distributed 
throughout the project area; therefore, CIBWs are expected to be able 
to resume foraging once they have moved away from any areas with 
disturbing levels of underwater noise. There is ample foraging habitat 
adjacent to the project area that will not be ensonified by pile 
driving. Further, impacts on primary prey species will be short-term 
and localized, and the project is not anticipated to substantially 
impede migration of adult or juvenile Pacific salmon or adversely 
affect the health and survival of the affected species at the 
population level. Affected fish would represent only a portion of food 
available to marine mammals in the area. While we agree with the 
commenters that noise pollution at the POA could impact both beluga and 
prey behavior near the POA, our initial negligible impact determination 
does not change due to possible CIBW foraging activities near Ship 
Creek. We have however, updated our negligible impact analysis to state 
that the area of exposure will be limited to habitat primarily used as 
a travel corridor to account for possible foraging activities within 
the area of exposure.
    Comment 3: The Defenders of Wildlife assert that NMFS must employ 
the precautionary principle and avoid sanctioning further impediments 
to the recovery of CIBWs even while striving to better understand those 
impediments.
    Response: 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 (where relevant). In making our determinations we 
consider factors such as those recommended by the commenters including 
the level of existing background noise, the additive noise, and the 
timing and importance of belugas' use of the impacted areas when 
deciding whether or not an activity will have a negligible impact on 
affected marine mammal species or stocks. 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). We discuss our analysis and 
findings in the Negligible Impact Analyses and Determinations sections 
of the Federal Notices of the proposed IHA (86 FR 31870, June, 15, 
2021) and this IHA. The extensive monitoring and mitigation required in 
the IHA and described in the Mitigation and Monitoring and Reporting of 
this notice supports these determinations. Neither the MMPA nor NMFS' 
implementing regulations include discussion or requirements related to 
a ``precautionary principle,'' and it would be inappropriate to deny 
the issuance of an IHA based on the precautionary principle if the MMPA 
issuance criteria have been satisfied.
    Comment 4: The Defenders of Wildlife expressed concern that NMFS 
set the Level B harassment threshold at 122.2 decibel (dB) (root mean 
square; rms) despite our understanding that responses including 
avoidance and altered group behaviors can be triggered at 120 dB. They 
also expressed concern that the entire width of Knik Arm may be 
ensonified by levels exceeding the Level B threshold preventing safe 
passage for belugas.
    Response: NMFS typically uses 120 dB (rms) as the exposure for 
estimating Level B harassment takes for continuous (e.g., vibratory 
pile driving) sources, but will adjust this threshold when background 
levels exceed this threshold such as in noisy environments like upper 
Cook Inlet. We acknowledge however that the use of a single threshold 
is a simplistic approach. This dB-based threshold 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 it is 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. Further, as is the case here, when the 
measured ambient noise is higher than the typical 120-dB continuous 
noise Level B harassment threshold (suggesting that marine mammals are 
regularly exposed to the higher level in the area), it is appropriate 
to raise the behavioral harassment threshold such that take by 
behavioral harassment is predicted only when marine mammals are 
predicted to receive sounds above the regularly occurring ambient noise 
in the area.

[[Page 50061]]

    NMFS reviewed data recently collected at the POA to establish an 
appropriate Level B harassment threshold for the SFD project. During 
the 2016 Test Pile Program (TPP), the POA conducted ``ambient'' 
acoustic monitoring, in accordance with accepted methodology for 
characterizing ambient noise levels (NMFS, 2012). 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 SFD project on marine mammals (NMFS, 2012). By using the 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. The median value thus provides a better representation of 
background noise levels that are applicable to when the SFD project 
would be occurring. During the 2016 TPP, median ambient noise levels 
(in the absence of pile driving) were 122.2 dB. More information of 
this analysis can be found in our notice of the proposed IHA. While 
background noise levels absent pile driving were collected by Reyff et 
al. (2021), these measurements were not collected in accordance to NMFS 
(2012) guidance for measuring ambient noise and thus cannot be used 
here for determining the Level B harassment threshold at the POA.
    The Defenders of Wildlife claim that noise from one component of 
the PCT project ensonified much, and at times all, of the mouth of Knik 
Arm to a level greater than the 122.5 dB Level B harassment standard 
used for that project making it difficult and at times impossible for 
belugas to transit the area without being harassed. We acknowledged in 
the Federal Register notice of the final IHAs for the PCT project (85 
FR 19294, April 06, 2020) that Level B harassment isopleths would 
extend across the mouth of Knit Arm. However, strict mitigation and 
monitoring measures were required that minimized any harassment to 
marine mammals in the project area and will be subsequently required 
for the SFD project. For example, the POA was required to shut down all 
pile driving activities should a CIBW approach or enter the mouth of 
Knit Arm or a Level B harassment zone. In addition, the MMPA gives NMFS 
the authority to authorize, upon request, the incidental, but not 
intentional, taking of small numbers of marine mammals if NMFS finds 
that 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). These findings were met in the Federal Register 
notice of the final IHAs for the PCT project and are similarly met for 
the relocation and construction of the POA's SFD, even though noise 
from some of the POA's activities may ensonify much or all of the mouth 
of Knik Arm.
    Comment 5: The Defenders of Wildlife concur that the available 
evidence indicates behavioral reactions to noise do not result in 
habitat abandonment, but they argue that the absence of evidence of 
habitat abandonments does not prove that noise impact around the Port 
are negligible.
    Response: 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). As described in the Negligible Impact Analysis and 
Determination sections of the Federal Notices of the proposed IHA (86 
FR 31870, June, 15, 2021) and this final IHA, 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). In our 
analysis, we discuss many factors, including the absence of habitat 
abandonments, to support our determination that the noise impacts from 
the POAs relocation and construction of the SFD are negligible. Our 
analysis also includes observations of large numbers of CIBWs entering 
and transiting through Knik Arm during pile driving activities (e.g., 
Kendall and Cornick, 2015, 61 North Environmental, 2021), many of whom 
were more likely to display no reaction or to continue to move towards 
the POA during PCT Phase 1 construction monitoring (61 North 
Environmental, 2021). Based on this analysis, and the required 
mitigation and monitoring, we have determined that the total marine 
mammal take from the POA's relocation and construction of the SFD will 
not affect annual rates of recruitment or survival, and thus will have 
a negligible impact on all affected marine mammal species or stocks.
    Comment 6: The Defenders of Wildlife commented that dredging at the 
Port would likely expose any beluga that enters or exits Knik Arm to 
levels of noise exceeding the current behavioral harassment threshold 
and cited Castellote et al. (2019) in support of this concern.
    Response: Dredging is not a component of the Port's specified 
activities; thus, this comment is not relevant to this IHA and is not 
discussed further.
    Comment 7: The Defenders of Wildlife support Castellote et al. 
(2019) who indicated that revision of the spatial extent of the current 
critical habitat exclusion zone (around the Port) is warranted as it 
coincides with the most acoustically disturbed area of Cook Inlet. 
Within their critical habitat discussion, they also support the 
recommendation by Castellote et al. (2019) that management implications 
for anthropogenic noise around the POA should include avoiding 
concurrent emission of noise at both the POA and Point McKenzie; 
evaluating the acoustic footprint of different modes and types of 
seasonal dredge operations; defining shut down protocols, if necessary, 
based on observed beluga behavioral reactions; and seasonal scheduling 
of activities to reduce overlap with beluga peak use of the port basin.
    Response: NMFS published the final rule designating critical 
habitat for CIBWs on April 11, 2011 (76 FR 20180). Designation or 
revision of critical habitat NMFS responsibility under the ESA and 
therefore is outside the scope of management actions taken under the 
MMPA and described in this notice and is not discussed further. More 
information on CIBW critical habitat can be found at https://www.fisheries.noaa.gov/action/critical-habitat-cook-inlet-beluga-whale.
    Comment 8: The Defenders of Wildlife support the recommendation 
cited by Castellote et al. (2019) that a cumulative impact analysis 
approach should be implemented as part of the permitting process.
    Response: Neither the MMPA nor NMFS' implementing regulations call 
for consideration of other unrelated activities and their impacts on 
populations. The preamble for NMFS' implementing regulations (54 FR 
40338; September 29, 1989) states in response to comments that the 
impacts from other past and ongoing anthropogenic activities are to be 
incorporated into the negligible impact analysis via their impacts on 
the baseline. Consistent with that direction, NMFS has factored into 
its negligible impact analysis the impacts of other past and ongoing 
anthropogenic activities via their impacts on the baseline, e.g., as 
reflected in the density/distribution and status of the species, 
population size and growth rate, and other relevant stressors. The 1989 
implementing regulations also addressed public comments regarding 
cumulative effects

[[Page 50062]]

from future, unrelated activities. There NMFS stated that such effects 
are not considered in making findings under section 101(a)(5) 
concerning negligible impact. In this case, both this IHA, as well as 
other IHAs currently in effect or proposed within the specified 
geographic region, are appropriately considered an unrelated activity 
relative to the others. The IHAs are unrelated in the sense that they 
are discrete actions under section 101(a)(5)(D), issued to discrete 
applicants.
    Section 101(a)(5)(D) of the MMPA requires NMFS to make a 
determination that the take incidental to a ``specified activity'' will 
have a negligible impact on the affected species or stocks of marine 
mammals. NMFS' implementing regulations require applicants to include 
in their request a detailed description of the specified activity or 
class of activities that can be expected to result in incidental taking 
of marine mammals. 50 CFR 216.104(a)(1). Thus, the ``specified 
activity'' for which incidental take coverage is being sought under 
section 101(a)(5)(D) is generally defined and described by the 
applicant. Here, the POA was the applicant for the IHA, and we are 
responding to the specified activity as described in that application 
(and making the necessary findings on that basis). Through the response 
to public comments in the 1989 implementing regulations, we also 
indicated (1) that NMFS would consider cumulative effects that are 
reasonably foreseeable when preparing a National Environmental Policy 
Act (NEPA) analysis, and (2) that reasonably foreseeable cumulative 
effects would also be considered under section 7 of the ESA for ESA-
listed species.
    In this case, cumulative impacts have been adequately addressed 
under NEPA in the final environmental assessment (EA) supporting NMFS' 
determination. In the final EA, we reviewed potential direct, indirect, 
and cumulative impacts to protected species and their environment, 
associated with NMFS' proposed action and alternatives. Separately, 
cumulative effects were analyzed as required through NMFS' required 
intra-agency consultation under section 7 of the ESA. The Biological 
Opinion (BiOp) that NMFS Alaska Region issued on August 9, 2021 
determined that NMFS' action of issuing the IHA is not likely to 
adversely affect listed marine mammals or their critical habitat.
    Comment 9: The Defenders of Wildlife raise a concern that while the 
Marine Mammal Commission has long advised NMFS to track all 
anthropogenic activities that may result in the taking of a beluga, and 
to place annual limits on the total number and types of take authorized 
based on the most recent population estimate, these suggestions, which 
are reflected in the Recovery Plan, have not yet been implemented. They 
recommend that in the absence of any limit on the total number of 
beluga takes authorized over a given time period, temporal restrictions 
that avoid additive noise impacts in already-ensonified areas where 
belugas are known to occur in significant numbers is a clear means of 
effecting the least practicable impact.
    Response: As stated in our response to Comment 3, 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 take authorization. 
It is worth noting that while the Defenders of Wildlife's provide 
estimates regarding the percentages of CIBWs authorized for take each 
year in IHAs to support their concern and reasoning for placing annual 
limits on take, they did not describe how they calculated these annual 
take estimates. We believe that the estimates they provide may be 
overestimated. The take estimates we authorize represent the upper 
limits for individuals, and some instances of take may represent 
multiple exposures to a single individual. 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, Unusual Mortality 
Events (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 a permanent threshold shift (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 BiOp per the ESA. The BiOp, issued August 9, 2021 
found NMFS' issuance of the IHA 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 
Defender or Wildlife's recommendation to cap the number of authorized 
takes of CIBWs across all activities for which take is requested.
    Comment 10: A private citizen submitted a comment via email 
expressing concern for NMFS' regulatory process, our issuance of IHAs' 
in general, and our definition of small numbers.
    Response: We appreciate the commenter's concern regarding the 
impacts from a wide variety of activities on species of marine mammals 
throughout U.S. regions. As discussed in the Background section of this 
final notice and our Response to Comment 3, while the MMPA prohibits 
the ``take'' of marine mammals, there are certain exceptions. For 
example, upon request, NMFS shall authorize the incidental, but not 
intentional, taking by harassment of small numbers of marine mammals 
for periods of not more than one year to applicants for a specified 
activity 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 (where relevant). As 
described in the Negligible Impact Analyses and Determinations section, 
NMFS' analysis supports the conclusion that the take anticipated to 
result from POA's activity, which

[[Page 50063]]

consists of 21 hours or pile driving, will have a negligible impact on 
the affected species or stocks. As described in the Small Numbers 
section, NMFS considers take of up to one-third the number of a 
species' or stock's abundance to be small (for additional explanation 
see the Small Numbers section in the Incidental Take Regulations for 
Geophysical Activities in the Gulf of Mexico: 86 FR 5322, 5438; January 
19, 2021), and authorized take is less than that for all affected 
species or stocks in this authorization. Accordingly, NMFS has issued 
the final authorization to POA.

Changes From the Proposed IHA to Final IHA

    No substantive changes have been made from the proposed IHA to 
final IHA; however, some small typos and clarifications were addressed 
including a clarification regarding shutdown zones. In the Federal 
Register notice for the proposed IHA (86 FR 31870, June 15, 2021) and 
this final notice we stated that if a marine mammal is entering or is 
observed within an established Level A harassment zone or shutdown 
zone, pile installation and removal will be halted or delayed. However, 
the table describing shutdown zones in the IHA (Table 2) only 
referenced a single 100-m shutdown zone. We have updated this table and 
language in this final notice to clarify that the shutdown zone is 100-
m unless the respective Level A harassment zone is larger; in these 
instances, the distance to the Level A harassment shutdown zone is the 
respective shutdown zone. We have also clarified language to better 
express that the IHA requirements pertain to construction activities 
directly associated with pile driving installation and removal rather 
than associated construction activities that occur away from the 
project site. Lastly, we noticed some repetitive measures so 
consolidated these to help clarify the requirements of the IHA.
    In addition, per the Defenders of Wildlife's concerns in Comment 2, 
we have updated the language in the Negligible Impact Analysis and 
Determination section to indicate that the area of exposure from the 
SFD activities will be limited to habitat primarily used as a travel 
corridor.

Description of Marine Mammals in the Area of Specified Activities

    There are six species of marine mammals that may be found in upper 
Cook Inlet during the pile driving activities. Sections 3 and 4 of the 
POA's application summarize available information regarding status and 
trends, distribution and habitat preferences, and behavior and life 
history, of the potentially affected species. Additional information 
regarding population trends and threats may be found in NMFS' Stock 
Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments), and more 
general information about these species (e.g., physical and behavioral 
descriptions) may be found on NMFS's website (https://www.fisheries.noaa.gov/find-species). Additional information on CIBWs 
may be found in NMFS' 2016 Recovery Plan for the CIBW (Delphinapterus 
leucas), available online at https://www.fisheries.noaa.gov/resource/document/recovery-plan-cook-inlet-beluga-whale-delphinapterus-leucas.
    Table 2 lists all species or stocks with expected potential for 
occurrence in the project area and summarizes information related to 
the population or stock, including regulatory status under the MMPA and 
Endangered Species Act (ESA) and potential biological removal (PBR), 
where known. For taxonomy, we follow Committee on Taxonomy (2019). PBR 
is defined by the MMPA as the maximum number of animals, not including 
natural mortalities, that may be removed from a marine mammal stock 
while allowing that stock to reach or maintain its optimum sustainable 
population (as described in NMFS's SARs). While no mortality is 
anticipated or authorized here, PBR and annual serious injury and 
mortality from anthropogenic sources are included here as gross 
indicators of the status of the species and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS' U.S. 2019 SARs (e.g., Muto et al., 2020) and 2020 draft SARs 
(Muto et al., 2021). All values presented in Table 2 are the most 
recent available at the time of publication and are available in the 
2019 and 2020 SARs (Muto et al., 2020; Muto et al., 2021) (available 
online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).

                                    Table 2--Marine Mammal Species Potentially Occurring in Upper Cook Inlet, Alaska
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         ESA/MMPA status;    Stock abundance (CV,
             Common name                  Scientific name               Stock             strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \1\          abundance survey) \2\               SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (rorquals):
    Humpback whale..................  Megaptera novaeangliae.  Western North Pacific..  E/D; Y              1,107 (0.3, 865, 2006)          3        2.8
                                                               Central North Pacific..  -/-; Y              10,103 (0.3, 7,890,            83         26
                                                                                                             2006).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Beluga whale....................  Delphinapterus leucas..  Cook Inlet.............  E/D; Y              279 (0.06, 267, 2018).       0.53          0
    Killer whale....................  Orcinus orca...........  Alaska Resident........  -/-; N              2,347 (N/A, 2,347,             24          1
                                                                                                             2012).
                                                               Alaska Transient.......  -/-; N              587 (N/A, 587, 2012)..       5.87        0.8
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena...............  Gulf of Alaska.........  -/-; Y              31,046 (0.21 N/A,           Undet         72
                                                                                                             1998).
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 50064]]

 
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
    Steller sea lion................  Eumetopias jubatus.....  Western................  E/D; Y              52,932 (N/A, 52,932           318        254
                                                                                                             2019).
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina.........  Cook Inlet/Shelikof....  -/-; N              28,411 (N/A, 26,907,          807        107
                                                                                                             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 mortality and serious injury (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.

    As indicated above, all six species (with six managed stocks) in 
Table 2 temporally and spatially co-occur with the activity to the 
degree that take is reasonably likely to occur, and we have authorized 
it. Marine mammals occurring in Cook Inlet that are not expected to be 
observed in the project area and for which take is not authorized 
include gray whales (Eschrichtius robustus), minke whales (Balaenoptera 
acutorostrata), and Dall's porpoise (Phocoenoides dalli).
    In addition, sea otters (Enhydra lutris) may be found in Cook 
Inlet. However, sea otters are managed by the U.S. Fish and Wildlife 
Service (USFWS) and are not considered further in this document.
    A detailed description of the of the species likely to be affected 
by the pile driving activities, 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 (86 FR 31870, June 15, 2021); since that time, we are not 
aware of any changes in the status of these species and stocks other 
than a change in the total annual mortality and serious injury for 
Steller sea lions which reflects corrections of errors found when 
finalizing Young et al. (2020) and the final SARs (Muto et al., 2021) 
(Note we also found typos in the minimum population estimate 
(N<INF>min</INF>) estimate for Alaska resident Killer whales and stock 
abundance for Steller sea lions in the Federal Register notice for the 
proposed IHA (86 FR 31870, June 15, 2021) that have been corrected 
here). Therefore, detailed descriptions are not provided here. Please 
refer to that Federal Register notice for these descriptions. Please 
also refer to NMFS' website (https://www.fisheries.noaa.gov/find-species) for generalized species accounts.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The Federal Register notice of the proposed IHA (86 FR 31870, June 
15, 2021) included a discussion of the effects of anthropogenic noise 
on marine mammals and the potential effects of underwater noise from 
the POA's specified activities on marine mammals and their habitat. 
That information and analysis is incorporated by reference into this 
final IHA determination and is not repeated here; please refer to the 
Federal Notice of the proposed IHA (86 FR 31870, June 15, 2021). No new 
data is available that suggests the potential responses and impacts to 
marine mammals would differ from those discussed in the notice of the 
proposed IHA.

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized through this IHA, which will inform both NMFS' consideration 
of ``small numbers'' and the negligible impact determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes will primarily be by Level B harassment, as pile 
driving has the potential to result in disruption of behavioral 
patterns for individual marine mammals, either directly or as a result 
of TTS. 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 required 
mitigation and monitoring measures are expected to minimize the 
severity of the taking to the extent practicable.
    As described previously, no mortality is anticipated or authorized 
for this activity. Below we describe how the take is estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
and the number of days of

[[Page 50065]]

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 authorized take estimate.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2012). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 micropascal ([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. This take estimation 
includes disruption of behavioral patterns resulting directly in 
response to noise exposure (e.g., avoidance), as well as that resulting 
indirectly from associated impacts such as TTS or masking. 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 recent acoustic monitoring conducted at the port are 
presented in Austin 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 
SFD Project on marine mammals (NMFS, 2012). By using the 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 2 days of data collection, 
no dredging was occurring. Therefore, the median provides a better 
representation of background noise levels when the SFD project will be 
occurring. With regard to spatial considerations of the measurements, 
the Ambient-Offshore location is most applicable to this discussion 
(NMFS, 2012). 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 expect Level B harassment to occur given mitigation measures 
(e.g., shut downs). We also recognize that during Phase 1 PCT acoustic 
monitoring, noise levels in Knik Arm absent pile driving were collected 
(Reyff et al., 2021); however, the Phase 1 PCT IHA did not require 
ambient noise measurements to be collected. These measurements were not 
collected in accordance to NMFS (2012) guidance for measuring ambient 
noise and thus cannot be used here for that purpose. 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) (NMFS, 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 activity includes the use of non-impulsive (vibratory pile 
driving) and impulsive (impact pile driving) sources.
    These thresholds are provided in Table 3 below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

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

[[Page 50066]]

 
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 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficient.
    The estimated sound source levels (SSL) proposed by the POA and 
used in this assessment for vibratory installation of attenuated piles 
are based on sound levels of 24-inch and 36-inch piles measured during 
a sound source verification (SSV) study conducted during Phase 1 of the 
POA's 2020 PCT project (Reyff et al., 2021). For the 24-inch template 
piles, SSLs measured for 24-inch PCT template piles by Reyff et al. 
(2021) were selected for use as a proxy for 24-inch SFD template piles 
based on anticipated pile function (Table 4). These piles were driven 
for 19.2 to 25.6 minutes, using an APE 200-6 vibratory hammer and a 
confined bubble curtain (Reyff et al., 2021). For the 36-inch template 
piles, SSLs are assumed to be similar to the SSLs measured for 36-inch 
trestle piles installed during PCT construction (note no 36-inch 
template piles were measured in Reyff et al., 2021) (Table 4). These 
piles were installed with a confined bubble curtain using an APE 300-6 
vibratory hammer; driving times ranged from 22.1 to 36.4 minutes. It is 
assumed that SLLs during pile installation and removal for both pile 
sizes will be similar.
    No unattenuated 24-inch or 36-inch piles were installed during 
either the TPP (Austin et al., 2016) or PCT SSV projects (Reyff et al., 
2021). Instead, SSL measurements collected during marine construction 
projects conducted by the U.S. Navy for the Naval Base Kitsap at Bangor 
EHW-2 Project (U.S. Navy, 2015), which were installed at similar depths 
and in a similar marine environment, were used as proxies for vibratory 
and impact installation of unattenuated piles for the SFD project 
(Table 4). It is assumed that SSLs during vibratory pile installation 
and removal will be similar.
    SSLs measurements for attenuated 24-inch and 36-inch piles driven 
with an impact hammer also were not measured during either the TPP 
(Austin et al., 2016) or PCT SSV projects (Reyff et al., 2021). SSL 
measurements for impact installation made by Ryeff et al. (2021) were 
on piles using a confined bubble curtain system with 48-inch piles; 
whereas, an unconfined system will be used with smaller piles for the 
SFD. In a confined bubble curtain system, the bubbles are confined to 
the area around the pile with a flexible material or rigid pipe; 
however, in an unconfined bubble curtain system, there is no such 
system for restraining the bubbles (NAVFAC SW, 2020). Unconfined bubble 
curtain performance is highly variable and effectiveness depends on the 
system design and on-site conditions such as water depth, water current 
velocity, substrate and underlying geology. The unconfined systems 
typically consist of vertically stacked bubble rings, while the 
confined systems are a single ring at the bottom placed inside a casing 
that encompasses the pile. The U.S. Navy (2015) summarized several 
studies which demonstrated that unconfined bubble curtains performance 
can be effective in attenuating underwater noise from impact pile 
installation. They found bubble curtain performance to be highly 
variable, but based on information from the Bangor Naval Base Test Pile 
Program, found an average peak SPL reduction of 8 dB to 10 dB at 10 m 
would be an achievable level of attenuation for steel pipe piles of 36- 
and 48-inches in diameter. The efficiency of bubble curtains with 24-
inch piles was not examined by the U.S. Navy (2015). Based on these 
analyses, and the effect that local currents may have on the 
distribution of bubbles and thus effectiveness of an unconfined bubble 
curtain, NMFS conservatively applies a 7 dB reduction to the U.S. Navy 
(2015) unattenuated SSLs (Table 4) for attenuated 24-inch and 36-inch 
piles during impact pile driving (Table 4). These SSLs are consistent 
with SSLs previously proposed and authorized by NMFS for POA impact 
pile driving of 24-inch and 36-inch piles (e.g., PCT final IHA [85 FR 
19294; April 6, 2020]). This reduction is more conservative than the 
confined bubble curtain efficacy reported by Reyff et al. (2021), which 
ranged from 9 to 11 dB for peak, rms, and sound exposure level (SEL) 
single strike measurements.
    The transmission loss (TL) coefficients reported in the PCT SSV are 
highly variable and are generally lower than values previously reported 
and used in the region. For example, Reyff et al. (2021) reported 
unweighted transmission loss coefficients ranging from 8.9 to 16.3 dB 
SEL and 7.0 to 16.7 dB rms for impact driving 48-inch attenuated piles. 
In the PCT final IHA (85 FR 19294; April 6, 2020), the POA proposed, 
and NMFS applied, a TL rate of 16.85 dB SEL for assessing potential for 
Level A harassment from impact pile driving and a TL rate of 18.35 dB 
rms when assessing potential for Level B harassment from impact pile 
driving for based on Austin et al. (2016) measurements recorded during 
the TPP on 48-in piles. Higher TL rates in Knik Arm are supported by 
additional studies, such as by [Scaron]irovi[cacute] and Kendall 
(2009), who reported a TL of 16.4 dB during impact hammer driving 
during passive acoustic monitoring of the POA Marine Terminal 
Redevelopment Project, and by Blackwell (2005) who reported TLs ranging 
from 16-18 dB SEL and 21.8 dB rms for impact and vibratory installation 
of 36-inch piles, respectively, during modifications made to the Port 
MacKenzie dock. After careful inspection of the data presented in the 
Reyff et al. (2021) study (including relevant spectrograms), NMFS is 
concerned that flow noise in the far field measurements is negatively 
biasing the regressions derived to infer TL rates. While Reyff et al. 
(2021) discuss attempts they made to remove flow noise from their 
calculations, NMFS could not conclude that these attempts adequately 
removed flow noise from their measurements. Relevant to the SFD, the TL 
calculations of individual vibratory installation of 24-inch template 
piles and 36-inch trestle piles reported by Reyff et al. (2021) were 
also highly variable ranging from 12.5 to 16.6 dB rms and 14.4 to 17.2 
dB rms, respectively. Given this variability and previous data 
suggesting higher TL rates, NMFS has determined that applying a 
practical spreading loss model (15logR) to ensonified area calculations 
is most likely the representative scenario in Knik Arm (Table 4). The 
15 TL coefficient also falls within the range of TL coefficients 
reported in Reyff et al. (2021).

[[Page 50067]]



                       Table 4--Estimated Sound Source Levels and Transmission Loss Coefficients With and Without a Bubble Curtain
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
     Method and pile size                               Unattenuated
                                                       Bubble curtain
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory....................       Sound level at 10 m (dB rms)
                                    TL coefficient
                                    Sound level at 10 m (dB rms)
                                TL coefficient (dB rms)
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-inch......................                 a 166.0
                                        c 15.0
                                              b 161.4
                                        c 15.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-inch......................                 a 161.0
                                        c 15.0
                                              b 158.5
                                        c 15.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
            Impact                                      Unattenuated
                                                       Bubble curtain
                              --------------------------------------------------------------------------------------------------------------------------
                                        Sound level at 10 m
                                    TL coefficient
                                        Sound level at 10 m
                                    TL coefficient
                              --------------------------------------------------------------------------------------------------------------------------
                                  dB rms       dB SEL      dB Peak      dB rms      dB SEL      dB rms      dB SEL      dB peak     dB rms      dB SEL
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-inch......................  a 194.0....  a 184.0....  a 211.0....  c 15.0....  c 15.0....  a 187.0...  a 177.0...  a 204.0...  c 15.0....  c 15.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-inch......................  a 193.0....  a 181.0....  a 210.0....  c 15.0....  c 15.0....  a 186.0...  a 174.0...  a 203.0...  c 15.0....  c 15.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
a U.S. Navy 2015.
b Reyff et al., 2021.
c Practical spreading loss model.

    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that ensonified area/volume could be more 
technically challenging to predict because of the duration component in 
the new thresholds, we developed a User Spreadsheet that includes tools 
to help predict a simple isopleth that can be used in conjunction with 
marine mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which may result in some degree of 
overestimate of Level A harassment take. However, these tools offer the 
best way to predict appropriate isopleths when more sophisticated 3D 
modeling methods are not available, and NMFS continues to develop ways 
to quantitatively refine these tools, and will qualitatively address 
the output where appropriate. For stationary sources (such as pile 
driving), NMFS User Spreadsheet predicts the distance at which, if a 
marine mammal remained at that distance the whole duration of the 
activity, it would incur PTS. Inputs used in the User Spreadsheet, and 
the resulting isopleths are reported below in Table 5.

                                      Table 5--NMFS User Spreadsheet Inputs
----------------------------------------------------------------------------------------------------------------
                                        24-Inch         24-Inch (bubble         36-Inch         36-Inch (bubble
                                    (unattenuated)         curtain)         (unattenuated)         curtain)
----------------------------------------------------------------------------------------------------------------
                                 User Spreadsheet Input: Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used............  A.1) Non-Impul,     A.1) Non-Impul,     A.1) Non-Impul,     A.1) Non-Impul,
                                   Stat, Cont.         Stat, Cont.         Stat, Cont.         Stat, Cont
Source Level (SPL RMS)..........  161...............  158.5.............  166...............  161.4.
Transmission Loss Coefficient...  15................  15................  15................  15.
Weighting Factor Adjustment       2.5...............  2.5...............  2.5...............  2.5.
 (kHz).
Time to install/remove single     45/75.............  45/75.............  45/75.............  45/75.
 pile (minutes).
Piles to install/remove per day.  1/1...............  1-2/1-3...........  1/1...............  1-3/1-3
----------------------------------------------------------------------------------------------------------------
                                   User Spreadsheet Input: Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used............  E.1) Impact pile    E.1) Impact pile    E.1) Impact pile    E.1) Impact pile
                                   driving.            driving.            driving.            driving.
Source Level (Single Strike/shot  181...............  174...............  184...............  177.
 SEL).
Transmission Loss Coefficient...  15................  15................  15................  15.
Weighting Factor Adjustment       2.................  2.................  2.................  2.
 (kHz).
Number of strikes pile..........  1,000.............  1,000.............  1,000.............  1,000.
Piles per day...................  1.................  1.................  1.................  1.
----------------------------------------------------------------------------------------------------------------

    To calculate the Level B harassment isopleths, NMFS considered 
SPLrms source levels and the corresponding TL coefficients (dB rms; 
Table 4) for impact and vibratory pile driving, respectively. The 
resulting Level A harassment and Level B harassment isopleths are 
presented in Table 6.

[[Page 50068]]



           Table 6--Distances to Level A Harassment, by Hearing Group, and Level B Harassment Thresholds per Pile Type and Installation Method
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                             Level A  harassment (m)              Level A
                                                                                  ---------------------------------------------  harassment
                                                          Hammer type      Piles                                                   areas       Level B
            Pile size                 Attenuation       (installation/    per day                                               (km\2\) all   harassment
                                                           removal)                   LF       MF       HF       PW       OW      hearing        (m)
                                                                                                                                   groups
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-inch.........................  Bubble Curtain....  Vibratory                 1        4        1        6        3        1        <0.01        2,631
                                                       (Installation).          2        7        1        9        4        1
                                                      Vibratory                 1        6        1        8        4        1
                                                       (Removal).               3       12        1       17        7        1
                                                      Impact                    1      251        9      299      135       10        <0.19          542
                                                       (Installation).
                                  Unattenuated......  Vibratory                 1        6        1        9        4        1        <0.01        3,861
                                                       (Installation).
                                                      Vibratory                 1        8        1       12        5        1
                                                       (Removal).
                                                      Impact                    1      735       27      876      394       29        <1.34        1,585
                                                       (Installation).
36-inch.........................  Bubble Curtain....  Vibratory                 1        6        1        9        4        1        <0.01        4,106
                                                       (Installation).
                                                      ..................        2       10        1       15        6        1
                                                      ..................        3       13        2       19        8        1
                                                      Vibratory                 1        9        1       13        6        1
                                                       (Removal).
                                                                                3       18        2       26       11        1
                                                      Impact                    1      398       15      474      213       16        <0.76          631
                                                       (Installation).
                                  Unattenuated......  Vibratory                 1       13        2       18        8        1        <0.01        8,318
                                                       (Installation).
                                                      Vibratory                 1       18        2       26       11        1
                                                       (Removal).
                                                      Impact                    1    1,165       42    1,387      624       46        <3.14        1,848
                                                       (Installation).
--------------------------------------------------------------------------------------------------------------------------------------------------------

Marine Mammal Occurrence and Take Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations.
    For all species of cetaceans other than CIBWs, 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 POA's construction season (April through November) across 
multiple years. Calculations used to estimate exposure from pile 
installation for all marine mammals is described below.

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 Inc., 2017) which is located south of the 
project area. Based on these data, the POA conservatively estimates 
that up to two individuals could be behaviorally harassed during the 24 
days of pile driving for the SFD. This could include sighting a cow-
calf pair on multiple days or multiple sightings of single humpback 
whales. No Level A harassment take of humpback whales is anticipated or 
authorized because the likelihood that a humpback whale would be both 
present in the project area and within the relatively small Level A 
harassment zones before a shutdown could be called is low.

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 or during Phase 1 of the PCT project in 2020. 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 CIBWs 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 one small pod (6 individuals). No Level A harassment 
take for killer whales is anticipated or authorized due to the small 
Level A harassment zones (Table 6) and implementation of a 100 m 
shutdown which is larger than Level A harassment isopleths, and 
described below in the Mitigation section.

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; however, during 
Phase 1 of the PCT project (2020), 18 individuals (15 groups) were 
observed near the POA, with group sizes ranging from 1-2 individuals. 
The highest daily sighting rate for any recorded year during pile 
installation and removal associated with the PCT was an average of 0.09 
harbor porpoise per day during 2009 construction monitoring, but this 
value may not account for increased sightings in Upper Cook Inlet or 
range extensions (Shelden et al., 2014). Therefore, the POA estimates 
that one harbor porpoise could be observed every 2 days of pile 
driving. Based on this assumption, the POA has requested, and NMFS is 
authorizing, twelve Level B harassment exposures during the 24 days of 
pile driving.
    Harbor porpoises are relatively small cetaceans that move at high 
velocities, which can make their detection and identification at great 
distances difficult. Despite this, PSOs during Phase 1 PCT construction 
monitoring (61 North Environmental, 2021) were able to detect harbor 
porpoises as far as 6,486 m from the PCT, indicating that the 
monitoring methods detailed in the final IHAs for Phase 1 and Phase 2 
PCT construction (85 FR 19294; April 6, 2020), (and described below in 
the Mitigation section for the SFD) allowed for harbor porpoises to be 
detected at great distances. Therefore, no Level A harassment take for 
harbor porpoises is anticipated or authorized for the SFD. The POA 
anticipates that the majority of piles will be driven using vibratory 
methods. Using the NMFS User Spreadsheet, vibratory driving 24-inch and 
36-inch piles results in Level A harassment isopleths that are smaller 
than the 100-m shutdown zone, described below in the Mitigation section 
(<=26 m; Table 6). The Level A harassment isopleths calculated using 
the NMFS User Spreadsheet for impact driving 24-inch and 36-inch piles 
are larger (<=1,387 m; Table 6); however, the

[[Page 50069]]

POA is required to shut down pile driving activities should a harbor 
porpoise be observed entering or within an established Level A 
harassment zone. In addition, Level A harassment isopleths consider 
long durations and harbor porpoise are likely moving through the area, 
if present, not lingering. Further few harbor porpoises are expected to 
approach the project area and are likely to be sighted prior to 
entering the Level A harassment zone. During Phase 1 PCT construction 
monitoring (61 North Environmental, 2021) only five harbor porpoises 
were observed near the PCT and within the largest Level A harassment 
zone for SFD (1,387 m; Table 7). Given that the POA anticipates that 
only a small number of piles (up to five), may be driven with an impact 
hammer (requiring up to 20 minutes of impact installation each at 1 
pile per day), the likelihood that harbor porpoises will be in these 
larger zones is minimized. Accounting for measures described below in 
the Mitigation section below and the low likelihood that individual 
harbor porpoises will appear undetected within the Level A harassment 
zones, we agree with the POA and do not authorize any Level A 
harassment takes of harbor porpoises during the construction of the 
SFD.

Steller Sea Lion

    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, two sightings 
occurred in 2016, one occurred in 2019, and up to six individuals were 
observed in 2020 (4 in May and 2 in June). Based on observations in 
2016, the POA anticipates an exposure rate of two individuals every 19 
days during SFD pile installation and removal. Based on this rate, The 
POA anticipates that there could be up to four harassment exposures of 
Steller sea lions during the 24 days of SFD pile installation and 
removal.
    Sea lions are known to travel at high speeds, in rapidly changing 
directions, and have the potential to be counted multiple times. 
Because of this the POA anticipates that, despite all precautions, sea 
lions could enter the Level A harassment zone before a shutdown could 
be fully implemented. For example, in 2016 during the POA TPP, a 
Steller sea lion was first sighted next to a work boat and within the 
Level A harassment zone. Nine PSOs had been monitoring for the presence 
of marine mammals near the construction activities at this time, but 
they did not observe the approaching sea lion. Sea lions are known to 
be curious and willing to approach human activity closely, and they can 
swim with a low profile. The incident was recorded as a Level A 
harassment take and raises concern for the POA that a sighting of a 
Steller sea lion within the Level A harassment zones, while unlikely, 
could occur. While Level A harassment takes are unlikely given the low 
likelihood of sea lions in the project area, the small Level A 
harassment isopleths (<46 m; Table 6), and the required mitigation 
measures, including the implementation of shutdown zones and the use of 
PSOs, we authorize the POA's request that a small number of Steller sea 
lions could be exposed to Level A harassment levels. Therefore, we 
authorize that two Steller sea lions could be exposed to Level A 
harassment levels and 2 Steller sea lions could be exposed to Level B 
harassment levels.

Harbor Seals

    No known harbor seal haulout or pupping sites occur in the vicinity 
of the POA; therefore, exposure of harbor seals to in-air noise is not 
considered in this application, and no take for in-air exposure is 
requested. Harbor seals are not known to reside in the project area, 
but they are seen regularly near the mouth of Ship Creek when salmon 
are running, from July through September. With the exception of newborn 
pups, all ages and sexes of harbor seals could occur in the project 
area during construction of the SFD. Any harassment of harbor seals 
during pile installation will involve a limited number of individuals 
that may potentially swim through the project area or linger near Ship 
Creek.
    Marine mammal monitoring data were used to examine hourly sighting 
rates for harbor seals in the project area. Sighting rates of harbor 
seals were highly variable and appeared to have increased during 
monitoring between 2005 and 2020 (See Table 4-1 in POA's application). 
It is unknown whether any potential increase was due to local 
population increases or habituation to ongoing construction activities. 
The highest monthly hourly sighting rate (rounded) observed during 
previous monitoring at the POA was used to quantify take of harbor 
seals for pile installation associated with the SFD. This occurred in 
2020 during Phase 1 PCT construction monitoring, when harbor seals were 
observed from May through September. A total of 340 harbor seals were 
observed over 1,237.7 hours of monitoring, at a rate of 0.3 harbor 
seals per hour. The maximum monthly hourly sighting rate occurred in 
September and was 0.51 harbor seals per hour. Based on these data, the 
POA estimates that approximately 1 harbor seal may be observed near the 
project per hour of hammer use. During the 21 hours of anticipated pile 
installation and removal, the POA estimates that up 21 harbor seals 
will be exposed to in-water noise levels exceeding harassment 
thresholds for pile installation and removal during SFD construction.
    All efforts will be taken to shut down prior to a harbor seal 
entering the appropriate shutdown zone and prior to a harbor seal 
entering the Level A harassment zones. However, harbor seals often are 
curious of onshore activities, and previous monitoring suggests that 
this species may mill at the mouth of Ship Creek. It is important to 
note that the mouth of Ship Creek is about 700 m from the southern end 
of the SFD and is outside the Level A harassment zones for harbor seals 
during both unattenuated and attenuated vibratory and impact pile 
installation and removal (Table 6). While exposure is anticipated to be 
minimized because pile installation and removal will occur 
intermittently over the short construction period, the POA is 
requesting Level A harassment take for a small number of harbor seals, 
given the potential difficulty of detecting harbor seals and their 
consistent use of the area. Given that 30 harbor seals (8.6 percent) of 
all harbor seals and unidentified pinnipeds were detected within 624 m, 
the largest Level A harassment zone for SFD, during PCT Phase 1 
construction monitoring (61 North Environmental, 2021), POA requests 
and NMFS authorizes that two harbor seals (8.6 percent of 21 exposures 
rounded up) could be exposed to Level A harassment levels and 19 harbor 
seals could be exposed to Level B harassment levels.

Beluga Whales

    For CIBWs, 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 SFD Project. 
In their application, the POA estimated Level B harassment take 
following methods outlined in the PCT final IHA (85 FR 19294; April 6, 
2020), which relies on monitoring data of CIBWs published in Kendall 
and Cornick (2015). For the SFD application, POA also considered 
monitoring data of CIBWs collected during Phase 1 of the PCT project 
(61 North Environmental, 2021). These data sets (Kendall and Cornick, 
2015, and 61 North Environmental, 2021) cover all months the POA could 
conduct pile driving for the SFD and they are based

[[Page 50070]]

on all animals observed during scientific monitoring within the 
proximity of the SFD regardless of distance. Hourly sighting rates for 
CIBWs for each calendar month were calculated using documented hours of 
observation and CIBW sightings from April through November for 2005, 
2006, 2008 and 2009 (Kendall and Cornick, 2015) and 2020 (61 North 
Environmental, 2021) (Table 7). The highest calculated monthly hourly 
sighting rate of 0.94 whales per hour was used to calculate potential 
CIBW exposures (21 hours of pile installation and removal multiplied by 
0.94 whales/hour). Using this method, the POA estimated that 20 CIBWs 
(rounded from 19.75) could be exposed to the Level B harassment level 
during pile installation and removal associated with the construction 
of the SFD. These calculations assume no mitigation and that all 
animals observed will enter a given Level B harassment zone during pile 
driving.

          Table 7--Summary of CIBWs Sighting Data From April-November 2005-2009 and April-November 2020
----------------------------------------------------------------------------------------------------------------
                      Month                         Total hours    Total groups    Total whales     Whales/hour
----------------------------------------------------------------------------------------------------------------
April...........................................           52.50              13              35            0.67
May.............................................          457.40              53             208            0.45
June............................................          597.77              37             122            0.20
July............................................          552.67              14              27            0.05
August..........................................          577.30             120             543            0.94
September.......................................          533.03             124             445            0.83
October.........................................          450.70               9              22            0.05
November........................................          346.63              52             272            0.78
----------------------------------------------------------------------------------------------------------------
Data compiled from Kendall and Cornick (2015) and (61 North Environmental, 2021).

    To more accurately estimate potential exposures than simply using 
the monthly sighting rate data, which does not account for any 
mitigation, POA followed methods described by NMFS for the PCT final 
IHA (85 FR 19294; April 6, 2020), which looked at previous monitoring 
results at the POA in relation to authorized take numbers. Between 2008 
and 2012, NMFS authorized 34 CIBW takes per year to POA, with 
mitigation measures similar to the measures required here. The percent 
of the authorized takes documented during this time period ranged from 
12 to 59 percent with an average of 36 percent (Table 8). In 2020, NMFS 
authorized 55 CIBW takes in Phase 1 of the PCT project, with mitigation 
and monitoring measures that are consistent with those required for the 
SFD and described below in the Mitigation section. The percent of the 
authorized takes that were documented was 47 percent (26 out of 55 
exposures; 61 North Environmental, 2021; Table 8). Given that there was 
extensive monitoring occurring across all IHAs (with effort intensified 
in 2020), we believe there is little potential that animals were taken 
but not observed.

            Table 8--Authorized and Reported CIBW Takes During POA Activities From 2009-2012 and 2020
----------------------------------------------------------------------------------------------------------------
                                                                                                    Percent of
                       ITA effective dates                        Reported takes    Authorized      authorized
                                                                                       takes           takes
----------------------------------------------------------------------------------------------------------------
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
1 April 2020-31 March 2021......................................              26              55              47
----------------------------------------------------------------------------------------------------------------

    As described in the POA's application and in more detail in the 
Mitigation section, mitigation measures have been designed to reduce 
Level B harassment take as well 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 CIBWs were 
initially sighted outside of the harassment zone and shutdown was 
called, but the CIBWs 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 CIBW 
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, 2010). On other occasions, CIBWs were initially observed 
when they surfaced within the harassment zone. For example, on November 
4, 2009, 15 CIBWs were initially sighted approximately 950 m north of 
the project site near the shore, and then they surfaced in the Level B 
harassment zone during vibratory pile driving (ICRC, 2010). 
Construction activities were immediately shut down, but the 15 CIBWs 
were nevertheless exposed within the Level B harassment zone. During 
Phase 1 of the PCT project all 26 of the recorded takes were instances 
where the whales were first sighted within the Level B harassment zone, 
prompting shutdown procedures. Most of these exposures (21 of 26) 
occurred when the CIBWs first appeared near the northern station, just 
south of Cairn Point (61 North Environmental, 2021). For example, on 
November 21, 2020 one CIBW was sighted in front of the north PSO 
station, located just south of Cairn Point, traveling south during 
vibratory removal of an attenuated 36-inch pile and a shutdown was 
called immediately (61 North Environmental, 2021). In 2020, the 
northern station did not have visibility of the near shoreline north of 
Cairn Point. As a result, CIBWs traveling south during ebb tides around 
Cairn Point were often inside of the Level B harassment zone upon first 
sighting (61 North Environmental,

[[Page 50071]]

2021). As described below in the Monitoring and Reporting section, 
mitigation and monitoring approaches for the SFD project are modeled 
after the stipulations outlined in the final IHAs for Phase 1 and Phase 
2 PCT construction (85 FR 19294; April 6, 2020), but one of the PSO 
stations will be moved to enhance visibility to the north, especially 
near Cairn point. Therefore, we believe the ability to detect whales 
and shut down prior to them entering the Level B harassment zones will 
be better or consistent with previous years.
    To account for these mitigation measures, the POA then applied the 
highest percentage of previous takes (59 percent) to ensure potential 
impacts to CIBWs are adequately evaluated. After applying this 
adjustment to account for potential exposures of CIBWs that will be 
avoided by shutting down, the POA estimated that 12 CIBWs (20 whales * 
0.59 = 11.80 whales; 12 rounded up) may be exposed to Level B 
harassment during pile installation and removal. The POA and NMFS are 
concerned, however, that this approach does not accurately reflect the 
reality that CIBWs can travel in large groups. Large groups of CIBWs 
have been seen swimming through the POA vicinity during POA monitoring 
efforts. For example, during Phase 1 of the PCT, the mean group size 
was 4.34 whales; however, 52 percent of observations were of groups 
greater than the mean group size, with 5 percent of those 119 groups 
being larger than 12 individuals, the number of exposures proposed by 
POA (61 North Environmental, 2021).
    To ensure that a large group of CIBWs will not result in the POA 
using the majority or all of their take in one or two sightings, POA 
buffered the exposure estimate detailed in the preceding paragraph by 
adding the estimated size of a notional large group of CIBWs. The 95th 
percentile is commonly used in statistics to evaluate risk. Therefore, 
to determine the most appropriate size of a large group, the POA 
calculated the 95 percentile group size of CIBWs observed during 
Kendall and Cornick (2015) and 2020 Phase 1 PCT construction monitoring 
(61 North Environmental, 2021); the same data used above to derive 
hourly sighting rates (Table 7 and Figure 3). In this case, the 95th 
percentile provides a conservative value that reduces the risk to the 
POA of taking a large group of CIBWs and exceeding authorized take 
levels. The 95th percentile of group size for the Kendall and Cornick 
(2015) and the PCT Phase 1 monitoring data (61 North Environmental, 
2021) is 12.0. This means that, of the 422 documented CIBW groups in 
these data sets, 95 percent consisted of fewer than 12.0 whales; 5 
percent of the groups consisted of more than 12.0. Considering large 
group size, the POA requests and we authorize 24 takes (accounting for 
the 12 takes calculated following the methods outlined for the PCT 
project that accounts for mitigation plus a group size of 12) of CIBWs 
incidental to pile driving for the SFD. Incorporation of large groups 
into the CIBW exposure estimate is intended to reduce risk to the POA 
of the unintentional take of a larger number of belugas than would be 
authorized by using the required methods alone and thus improve our 
estimate of exposure. No Level A harassment is expected or authorized 
given the small Level A harassment zones for CIBWs (Table 6) and the 
additional mitigation measures described in the Mitigation section 
below specific to CIBWs, including the measure that pile driving 
activities must shut down when any CIBW enters the relevant Level B 
harassment zone.
[GRAPHIC] [TIFF OMITTED] TN07SE21.002

    In summary, the total amount of Level A harassment and Level B 
harassment authorized for each marine mammal stock is presented in 
Table 9.

[[Page 50072]]



                        Table 9--Authorized Amount of Take, by Stock and Harassment Type
----------------------------------------------------------------------------------------------------------------
                                                                          Authorized take
                Species                           Stock          --------------------------------   Percent of
                                                                      Level A         Level B          stock
----------------------------------------------------------------------------------------------------------------
Humpback whale........................  Western N. Pacific......               0               2            0.19
Beluga whale..........................  Cook Inlet..............               0              24            8.60
Killer whale..........................  Transient/Alaska                       0               6       1.02/0.26
                                         Resident.
Harbor porpoise.......................  Gulf of Alaska..........               0              12            0.04
Steller sea lion......................  Western.................               2               2           <0.01
Harbor seal...........................  Cook Inlet/Shelikof.....               2              19            0.07
----------------------------------------------------------------------------------------------------------------

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 the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
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 were modeled after the stipulations outlined in the 
final IHAs for Phase 1 and Phase 2 PCT construction (85 FR 19294; April 
6, 2020), which were successful in minimizing the total number and 
duration of Level B harassment exposures for endangered CIBWs during 
Phase 1 PCT Construction (61 North Environmental, 2021). These measures 
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 
deploy an unconfined bubble curtain system during installation and 
removal of plumb (vertical) 24- and 36-inch piles with a vibratory or 
impact hammer. An unconfined bubble curtain is composed of an air 
compressor(s), supply lines to deliver the air, distribution manifolds 
or headers, perforated aeration pipe, and a frame. The frame 
facilitates transport and placement of the system, keeps the aeration 
pipes stable, and provides ballast to counteract the buoyancy of the 
aeration pipes in operation. The air is released through a series of 
vertically distributed bubble rings that create a cloud of bubbles that 
act to impede and scatter sound, lowering the sound velocity. A 
compressor provides a continuous supply of compressed air, which is 
distributed among the layered bubble rings. Air is released from small 
holes in the bubble rings to create a curtain of air bubbles 
surrounding the pile. The curtain of air bubbles floating to the 
surface inhibits the transmission of pile installation sounds into the 
surrounding water column. The final design of the bubble curtain will 
be determined by the Construction Contractor based on factors such as 
water depth, current velocities, and pile sizes. However, the IHA 
requires the bubble curtain be operated in a manner consistent with the 
following performance standards:
    <bullet> The aeration pipe system will consist of multiple layers 
of perforated pipe rings, stacked vertically in accordance with the 
following depths: Two layers for water depths <5 m; four layers for 
water depths 5 m to <10 m; seven layers for water depths 10 m to <15 m; 
ten layers for water depths 15 m to <20 m; and thirteen layers for 
water depths 20 m to <25 m;
    <bullet> The pipes in all layers will be arranged in a geometric 
pattern that will allow for the pile being driven to be completely 
enclosed by bubbles for the full depth of the water column and with a 
radial dimension such that the rings are no more than 0.5 m from the 
outside surface of the pile;
    <bullet> The lowest layer of perforated aeration pipe will be 
designed to ensure contact with the substrate without burial and will 
accommodate sloped conditions;
    <bullet> Air holes will be 1.6 millimeters (1/16 inch) in diameter 
and will be spaced approximately 20 millimeters (\3/4\ inch) apart. Air 
holes with this size and spacing will be placed in four adjacent rows 
along the pipe to provide uniform bubble flux;
    <bullet> The system will provide a bubble flux of 3 cubic meters 
(m\3\) per minute per linear meter of pipe in each layer (32.91 cubic 
feet (ft\3\) per minute per linear foot of pipe in each layer). The 
total volume (Vt) of air per layer is the product of the bubble flux 
and the circumference of the ring using the formula: Vt = 3.0 m\3\/min/
m * Circumference of the aeration ring in meters or Vt = 32.91 ft\3\/
min/ft * Circumference of the aeration ring in feet; and
    <bullet> Meters must be provided as follows:
    [cir] Pressure meters must be installed at all inlets to aeration 
pipelines and at points of lowest pressure in each branch of the 
aeration pipeline;
    [cir] Flow meters must be installed in the main line at each 
compressor and at each branch of the aeration pipelines at each inlet. 
In applications where the feed line from the compressor is continuous 
from the compressor to the aeration pipe inlet, the flow meter at the 
compressor can be eliminated; and

[[Page 50073]]

    [cir] Flow meters must be installed according to the manufacturer's 
recommendation based on either laminar flow or non-laminar flow.
    The bubble curtain will be used during installation and removal of 
all plumb piles when water depth is great enough (approximately 3 m or 
9.8 ft) to deploy the bubble curtain. A bubble curtain will not be used 
with the two battered piles due to the angle of installation. It is 
important to note that a small number of piles could be installed or 
removed when the pile location is de-watered (no water present) or when 
the water is too shallow (<=3 m or 9.8 ft) to deploy the bubble 
curtain. The tides at the POA have a mean range of about 8.0 m (26 ft) 
(NOAA, 2015), and low water levels will prevent proper deployment and 
function of the bubble curtain system. Piles that are driven at a 
location that is de-watered will not use a bubble curtain, and marine 
mammal harassment zones will not be monitored. When piles are installed 
or removed in water without a bubble curtain because the pile 
orientation is battered, or if water is too shallow (<=3 m or 9.8 ft) 
to deploy the bubble curtain, the unattenuated Level A and Level B 
harassment zones for that hammer type and pile size will be 
implemented.
    In addition to noise attenuation devices, POA and NMFS considered 
practicable work restrictions. Given the extensive Level B harassment 
zone generated from the installation of the two unattenuated battered 
piles, vibratory driving these large piles during peak CIBW season 
poses an amount of risk and uncertainty to the degree that it should be 
minimized. This August and September peak is confirmed through acoustic 
monitoring (Castellote et al., 2020) and Phase 1 PCT construction 
monitoring (61 North Environmental, 2021). Castellote et al. (2020) for 
example indicate CIBWs 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. Further, hourly sighting rates calculated 
from monitoring data from Kendall and Cornick (2015) and Phase 1 of the 
PCT (61 North Environmental, 2021) were highest in August and September 
(0.94 and 0.83, respectively; Table 8). Therefore, vibratory driving 
unattenuated battered piles (which have, by far, the largest Level B 
harassment zones) will not occur during August or September. 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 CIBW 
abundance periods, NMFS is not proposing to restrict the operation of 
two impact hammers at the same time. Given the small size of the 
project and the plan to primarily drive hammers with a vibratory 
hammer, the POA has indicated that it is highly unlikely that an impact 
hammer and vibratory hammer or two impact hammers will operate 
simultaneously during the SFD project.
    Additional mitigation measures include the following, modeled after 
the stipulations outlined in the final IHAs for Phase 1 and Phase 2 PCT 
construction (85 FR 19294; April 6, 2020):
    For in-water construction involving heavy machinery activities 
other than pile driving (e.g., use of barge-mounted excavators), the 
POA will cease operations and 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 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. Soft starts will not be used for vibratory pile 
installation and removal. PSOs shall begin observing for marine mammals 
30 minutes before ``soft start'' or in-water pile installation or 
removal begins.
    The POA will conduct briefings for construction supervisors and 
crews, the monitoring team, and POA staff prior to the start of all 
pile installation and removal, and when new personnel join the work in 
order to explain responsibilities, communication procedures, the marine 
mammal monitoring protocol, and operational procedures.
    The POA will employ PSOs per the Marine Mammal Monitoring Plan (see 
Appendix A in the POA's application).
    Marine mammal monitoring will take place from 30 minutes prior to 
initiation of pile installation and removal through 30 minutes post-
completion of pile installation and removal. The Level B harassment 
zone must be fully visible for 30 minutes before the zone can be 
considered clear. Pile driving will commence when observers have 
declared the shutdown zone clear of marine mammals or the mitigation 
measures developed specifically for CIBWs (below) are satisfied. In the 
event of a delay or shutdown of activity, marine mammal behavior will 
be monitored and documented until the marine mammals leave the shutdown 
zone of their own volition, at which point pile installation or removal 
will begin. Further, NMFS requires that if pile driving has ceased for 
more than 30 minutes within a day and monitoring is not occurring 
during this break, 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 
Level A harassment zone or shutdown zone, pile installation and removal 
will be halted or delayed. Pile driving will not commence or resume 
until either the animal has voluntarily left and been visually 
confirmed 100 m beyond the shutdown zone and on a path away from such 
zone, or 15 minutes (non-CIBWs) or 30 minutes (CIBWs) have passed 
without subsequent detections.
    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 Level B harassment 
zone, pile installation and removal will shut down immediately. Pile 
driving will not resume until the animal has been confirmed to have 
left the area or the 30 minute observation period has elapsed.
    In addition to these measures which greatly reduce the potential 
for harassment of all marine mammals and establish shutdown zones that 
realistically reflect non-CIBW whale detectability, the following 
additional mitigation measures will ensure valuable protection and 
conservation of CIBWs:
    Prior to the onset of pile driving, should a CIBW be observed 
approaching the mouth of Knik Arm, pile driving will be delayed. An in-
bound pre-clearance line extends from Point Woronzof to approximately 
2.5 km west of Point McKenzie. Pile driving may commence once the 
whale(s) moves at least 100 m past the Level B harassment zone or pre-
clearance zone (whichever is larger) and on a path away from the zone. 
A similar pre-pile driving clearance zone will be established to the

[[Page 50074]]

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 or pre-clearance zone 
(whichever is larger) and on a path away from the zone. If non-CIBW 
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 relevant shutdown 
zone and Level B harassment takes have not been exceeded.
    If pile installation or removal has commenced, and a CIBW(s) is 
observed within or likely to enter the Level B harassment zone, pile 
installation or removal will shut down and not re-commence until the 
whale has traveled at least 100 m beyond the Level B harassment zone 
and is on a path away from such zone or until no CIBW has been observed 
in the Level B harassment zone for 30 minutes
    There may be situations where it is not possible to monitor the 
entire Level B harassment zone (e.g., during vibratory hammering of two 
unattenuated battered piles). In these cases, the pre-clearance zone 
remains applicable.
    If during installation and removal of piles, PSOs can no longer 
effectively monitor the entirety of the CIBW Level B harassment zone 
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 
will be cleared again for 30 minutes prior to pile driving.
    Based on our evaluation of the applicant's proposed measures, NMFS 
has determined that the required mitigation measures provide the means 
effecting the least practicable impact on the affected species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

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:
    <bullet> Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
    <bullet> Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
    <bullet> Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
    <bullet> How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
    <bullet> Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
    <bullet> Mitigation and monitoring effectiveness.
    The POA will implement a marine mammal monitoring and mitigation 
strategy intended to avoid and minimize impacts to marine mammals (see 
Appendix A in the POA's application). The marine mammal monitoring and 
mitigation program that is planned for SFD construction will be modeled 
after the stipulations outlined in the final IHAs for Phase 1 and Phase 
2 PCT construction (85 FR 19294; April 6, 2020). The POA will collect 
electronic data on marine mammal sightings and any behavioral responses 
to in-water pile installation or removal for species observed during 
pile installation and removal associated with the SFD Project. Four PSO 
teams will work concurrently to provide full coverage for marine mammal 
monitoring in rotating shifts during in-water pile installation and 
removal. All PSOs will be trained in marine mammal identification and 
behaviors. NMFS will review submitted PSO resumes and indicate approval 
as warranted.
    All PSOs will also undergo project-specific training, which will 
include training in monitoring, data collection, theodolite operation, 
and mitigation procedures specific to the SFD Project. This training 
will also include site-specific health and safety procedures, 
communication protocols, and supplemental training in marine mammal 
identification and data collection specific to the SFD Project. 
Training will include hands-on use of required field equipment to 
ensure that all equipment is working and PSOs know how to use the 
equipment.
    Eleven PSOs will be distributed at four stations: Anchorage 
Downtown Viewpoint near Point Woronzof, the Anchorage Public Boat Dock 
at Ship Creek, the SFD Project site, and the north end of POA property. 
These locations were chosen to maximize CIBW detection outside of Knik 
Arm and the mouth of Knik Arm. Specifically, PSOs at Port Woronzof will 
have unencumbered views of the entrance to Knik Arm and can provide 
information on CIBW group dynamics (e.g., group size, demographics, 
etc.) and behavior of animals approaching Knik Arm in the absence of 
and during pile driving. During the time since the POA submitted their 
final application, observers for the 2020 PCT Phase 1 project have 
recommended, and NMFS has included in the IHA, that the Ship Creek 
station be moved about 40 m to the end of the promontory to enhance 
visibility to the north, especially near Cairn point. The POA also 
considered moving a station from the POA property to Port MacKenzie for 
an improved view of CIBWs 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 remain located on POA 
property.
    Each of the PSO stations will be outfitted with a cargo container 
with an observation platform constructed on top. This additional 
elevation provides better viewing conditions for seeing distant marine 
mammals than from ground level and provides the PSOs with protection 
from weather. At least two PSOs will be on watch at any given time at 
each station; one PSO will be observing, one PSO will be recording data 
(and observing when there are no

[[Page 50075]]

data to record). The station at the SFD site will have at least two 
PSOs. The northern and southern observations stations will have PSOs 
who will work in three- to four-person teams. Teams of three will 
include one PSO who will be observing, one PSO who will be recording 
data (and observing when there are no data to record), and one PSO who 
will be resting. When available, a fourth PSO will assist with 
scanning, increasing scan intensity and the likelihood of detecting 
marine mammals. PSOs will work on a 30 to 60 minute rotation cycle and 
may observe for no more than 4 hours at time and no more than 12 hours 
per day. 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.
    Trained PSOs will have no other construction-related tasks or 
responsibilities while conducting monitoring for marine mammals. 
Observations will be carried out using combinations of equipment that 
include 7 by 50 binoculars, 20x/40x tripod mounted binoculars, 25 by 
150 ``big eye'' tripod mounted binoculars (North End, Ship Creek, and 
Woronzof), and theodolites. PSOs will be responsible for monitoring the 
shutdown zones, the Level A harassment zones, the Level B harassment 
zones, and the pre-clearance zones, as well as effectively documenting 
Level A and Level B harassment take. They will also (1) report on the 
frequency at which marine mammals are present in the project area, (2) 
report on behavior and group composition near the POA, (3) record all 
construction activities, and (4) report on observed reactions (changes 
in behavior or movement) of marine mammals during each sighting. 
Observers will monitor for marine mammals during all in-water pile 
installation and removal associated with the SFD Project. Once pile 
installation and removal are completed for the day, marine mammal 
observations will continue for 30 minutes. Observers will work in 
collaboration with the POA to immediately communicate the presence of 
marine mammals prior to or during pile installation or removal.
    A draft report, including all electronic data collected and 
summarized from all monitoring locations, must be submitted to NMFS' 
MMPA program within 90 days of the completion of monitoring efforts. 
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 Level A 
harassment zones, the Level B harassment zones, and the shutdown zones, 
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. A final marine mammal monitoring report will be prepared and 
submitted to NMFS within 30 days following receipt of comments on the 
draft report from NMFS.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS' implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    To avoid repetition, the discussion of our analyses applies to all 
the species listed in Table 9 for which we authorized take, other than 
CIBWs, as the anticipated effects the POAs 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. The potential effects of the 
specified actions on these species are discussed above. Some of these 
factors also apply to CIBWs; however, a more detailed analysis for 
CIBWs is provided below.
    <bullet> No takes by mortality or serious injury are anticipated or 
authorized;
    <bullet> The number of total takes (by Level A and Level B 
harassment) are less than 2 percent of the best available abundance 
estimates for all stocks;
    <bullet> Take will 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);
    <bullet> Take will occur over a short timeframe (i.e., up to 21 
total hours spread over nine to 24 non-consecutive days), and will be 
limited to the short duration a marine mammal would likely be present 
within a Level B harassment zone during pile driving. This short 
timeframe minimizes the probability of multiple exposures on 
individuals, and any repeated exposures that do occur are not expected 
to occur on sequential days, decreasing the likelihood of physiological 
impacts caused by chronic stress or sustained energetic impacts that 
might affect survival or reproductive success;
    <bullet> Any impacts to marine mammal habitat from pile driving 
(including to prey sources as well as acoustic habitat,

[[Page 50076]]

e.g., from masking) are expected to be temporary and minimal; and
    <bullet> Take will 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 CIBW (NMFS, 2016a), 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 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 CIBWs, (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 CIBWs. The SFD will not impact 
essential features 1-3 listed above. All construction will be done in a 
manner implementing best management practices to preserve water 
quality, and no work will occur around creek mouths or river systems 
leading to prey abundance reductions. In addition, no physical 
structures will restrict passage; however, impacts to the acoustic 
habitat are of concern. Previous marine mammal monitoring data at the 
POA demonstrate CIBWs indeed pass by the POA during pile driving (e.g., 
61 North Environmental, 2021). As described above, there was no 
significant difference in CIBW sighting rate with and in the absence of 
pile driving (Kendall and Cornick, 2015). However, CIBWs do swim faster 
and in tighter formation in the presence of pile driving (Kendall and 
Cornick, 2015).
    Previously there has been concern that exposure to pile driving at 
the POA could result in CIBWs avoiding Knik Arm and thereby not 
accessing the productive foraging grounds north of POA such as Eagle 
River flats based on the specified project and mitigation measures--
thus, impacting essential feature number five above (85 FR 19294; April 
6, 2020). 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), 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, helped 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 CIBWs 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 http://www.smruconsulting.com/publications/ with 
a summary of the expert elicitation portion of the workshop below.
    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 percent of its energy intake on 
that day). The day of disturbance considered in the context of the 
report is notably more severe than the Level B harassment expected to 
result from these activities, which as described is expected be 
comprised predominantly of temporary modifications in the behavior of 
individual CIBWs (e.g., faster swim speeds, more cohesive group 
structure, avoidance, and increased foraging). Also, NMFS anticipates 
and has authorized 24 instances of takes, with the instances 
representing disturbance events within a day--this means that either 24 
different individual beluga whales are disturbed on no more than one 
day each, or some lesser number of individuals may be disturbed on more 
than one day, but with the product of individuals and days not 
exceeding 24. Given the overall anticipated take, it is very unlikely 
that any one beluga will be disturbed on more than a few days. Further, 
the mitigation measures NMFS has prescribed for the SFD project are 
designed to avoid the potential that any animal will lose the ability 
to forage for one or more tidal cycles. While Level B harassment 
(behavioral disturbance) is authorized, our mitigation measures will 
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 CIBWs 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 CIBWs 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 (Kendall and Cornick, 2015). In addition, large numbers 
of CIBWs continued to use Knik Arm in 2020 during the duration of the 
PCT Phase 1 construction project (61 North Environmental, 2021). These 
findings are 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

[[Page 50077]]

in historical foraging areas despite negative impacts (e.g., Rolland et 
al., 2012). Previous monitoring data indicates CIBWs 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). During PCT 
Phase 1 construction monitoring, no definitive behavioral reactions to 
the in-water activity or avoidance behaviors were documented in CIBW. 
Little variability was evident in CIBW behaviors recorded by PSOs from 
month to month, or between sightings that coincided with in-water pile 
installation or removal and those that did not (61 North Environmental, 
2021). Of the 245 CIBWs groups sighted during PCT Phase 1 construction 
monitoring, seven groups were observed during or within minutes of in-
water impact pile installation and 37 groups were observed during or 
within minutes of vibratory pile installation or removal (61 North 
Environmental, 2021). During impact installation, three of these groups 
of CIBWs showed no reaction, three showed a potential reaction, and one 
group continued moving towards impact pile installation. Of the 37 
vibratory events monitored, nine groups of CIBWs displayed a potential 
reaction, 16 displayed no reaction, and 12 continued a trajectory 
towards the PCT (61 North Environmental, 2021). In general, CIBWs were 
more likely to display no reaction or to continue to move towards the 
PCT during pile installation and removal. In the situations during 
which CIBWs showed a possible reaction (three groups during impact 
driving and nine groups during vibratory driving), CIBWs were observed 
either moving away immediately after the pile driving activities 
started or observed increasing their rate of travel. 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 CIBWs moved through that area relatively 
quickly when entering or exiting the Arm. We anticipate that 
disturbance to CIBWs will manifest in the same manner when they are 
exposed to noise during the SFD project: Whales move quickly and 
silently through the area in more cohesive groups. We 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. We also do not anticipate that CIBWs 
will abandon entering or exiting Knik Arm, as this is not evident based 
on previous years of monitoring data (e.g., Kendall and Cornick, 2015; 
61 North Environmental, 2021), and the pre-pile driving clearance 
mitigation measure is designed to further avoid any potential 
abandonment. Finally, as described previously, both telemetry (tagging) 
and acoustic data suggest CIBWs likely stay in upper Knik Arm for 
several days or weeks before exiting Knik Arm. Specifically, a CIBW 
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 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 will avoid repetitive 
exposures from pile driving noise.
    POA proposed and NMFS has prescribed mitigation measures to 
minimize exposure to CIBWs, specifically, shutting down pile driving if 
CIBWs are observed approaching the mouth of Knik Arm, shutting down 
pile driving should a CIBW approach or enter the Level B harassment 
zone, stationing PSOs at Point Woronzof and Ship Creek, and not 
vibratory pile driving unattenuated battered piles during August or 
September (peak CIBW season). These measures are designed to ensure 
CIBWs 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 CIBWs and behavioral observations prior to 
CIBWs entering Knik Arm. Although NMFS does not anticipate CIBWs will 
abandon entering Knik Arm in the presence of pile driving with the 
required mitigation measures, these PSOs will be integral to 
identifying if CIBWs are potentially altering pathways they would 
otherwise take in the absence of pile driving. 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 this activity 
are not expected to adversely affect the CIBWs through effects on 
annual rates of recruitment or survival:
    <bullet> No mortality is anticipated or authorized;
    <bullet> Area of exposure will be limited to habitat primarily used 
as a travel corridor. Data demonstrates Level B harassment manifests as 
increased swim speeds past the POA and tight group formations and not 
through habitat abandonment;
    <bullet> No critical foraging grounds (e.g., Eagle Bay, Eagle 
River, Susitna Delta) will be impacted by pile driving; and
    <bullet> 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 (Shelden 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 the cases where shutdowns cannot occur in time to avoid Level B 
harassment take) will not impact the reproduction or survival of any 
individuals, much less the stock, and will thereby 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 will undetected. The mitigation measures 
reduce noise entering the water column (a benefit for all marine 
mammals) through the use of an unconfined bubble curtain. 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 will 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 individual fitness or 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.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals

[[Page 50078]]

and their habitat, and taking into consideration the implementation of 
the required monitoring and mitigation measures, NMFS finds that the 
total marine mammal take from the specified activity will have a 
negligible impact on all affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. When the predicted number of 
individuals to be taken is fewer than one third of the species or stock 
abundance, the take is considered to be of small numbers. Additionally, 
other qualitative factors may be considered in the analysis, such as 
the temporal or spatial scale of the activities. For all stocks, the 
amount of taking is less than one-third of the best available 
population abundance estimate (in fact it is less than 9 percent for 
all stocks considered here; Table 9).
    Based on the analysis contained herein of the specified activity 
(including the required mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS finds that small numbers of 
marine mammals will be taken relative to the population size of the 
affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    In order to issue an IHA, NMFS must find that the specified 
activity will not have an ``unmitigable adverse impact'' on the 
subsistence uses of the affected marine mammal species or stocks by 
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50 
CFR 216.103 as an impact resulting from a specified activity that is 
likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by either causing 
the marine mammals to abandon or avoid hunting areas, directly 
displacing subsistence users, or placing physical barriers between the 
marine mammals and the subsistence hunters. An ``unmitigable adverse 
impact'' can also result from a specified activity 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 Alaska 
Department of Fish and Game 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 will 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 will 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 will 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 
will 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 
the proposed IHA. No tribes commented on or expressed concern over 
subsistence use during the public comment period for the proposed IHA.
    Based on the description of the specified activity, the measures 
described to minimize adverse effects on the availability of marine 
mammals for subsistence purposes, and the required mitigation and 
monitoring measures, NMFS has determined that there will not be an 
unmitigable adverse impact on subsistence uses from the POA's specified 
activities.

Endangered Species Act

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency 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 whenever we propose to authorize take for 
endangered or threatened species, in this case with the Alaska Region 
Protected Resources Division Office.
    There are two marine mammal species (CIBWs and western DPS Steller 
sea lions) with confirmed occurrence in the project area that are 
listed as endangered under the ESA. The NMFS Alaska Regional Office 
Protected Resources Division issued a BiOp on August 9, 2021, under 
section 7 of the ESA, on the issuance of an IHA to the POA under 
section 101(a)(5)(D) of the MMPA by the NMFS Permits and Conservation 
Division. The BiOp concluded that the specified action is not likely to 
jeopardize the continued existence of CIBWs or western DPS Steller sea 
lions, and is not likely to destroy or adversely modify CIBW critical 
habitat. There is no critical habitat designated for humpback whales or 
Steller sea lions in the action area.

National Environmental Policy Act

    NMFS prepared an EA and analyzed the potential impacts to marine 
mammals that will result from the POA SFD construction project. This EA 
was made available to the public for review during the public comment 
period of the proposed IHA; we did not receive any comments from the 
public relevant to the EA. A Finding of No Significant Impact (FONSI) 
was signed on August 10, 2021. A copy of the EA and FONSI is available 
upon online at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.

Authorization

    NMFS has issued an IHA to the POA or the potential harassment of 
small numbers of six marine mammal species incidental to the SFD 
project in Knit Arm, Alaska, provided the previously mentioned 
mitigation, monitoring and reporting requirements are followed.


[[Page 50079]]


    Dated: August 31, 2021.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2021-19187 Filed 9-3-21; 8:45 am]
BILLING CODE 3510-22-P