[Federal Register Volume 86, Number 212 (Friday, November 5, 2021)]
[Notices]
[Pages 61141-61160]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-24274]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XB439]


Takes of Marine Mammals Incidental To Specified Activities; 
Taking Marine Mammals Incidental to the Palmer Station Pier Replacement 
Project, Antarctica

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 
National Science Foundation (NSF) to incidentally harass, by Level B 
harassment and Level A harassment, marine mammals during pile driving 
activities associated with the construction of the Palmer Station Pier 
Replacement Project in Anvers Island, Antarctica.

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

FOR FURTHER INFORMATION CONTACT: Robert Pauline, 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.

[[Page 61142]]


SUPPLEMENTARY INFORMATION:

Background

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

Summary of Request

    On December 29, 2020, NMFS received a request from the National 
Science Foundation (NSF) for an IHA to take marine mammals incidental 
to pile driving activities associated with the construction of the 
Palmer Station Pier Replacement Project on Anvers Island, Antarctica. 
Hereafter (unless otherwise specified) the term ``pile driving'' is 
used to refer to both pile installation (including DTH pile 
installation) and pile removal. NSF submitted several revisions of the 
application until it was deemed adequate and complete on July 15, 2021. 
NSF had requested, and NMFS has authorized, take of a small number of 
17 species of marine mammals by Level B harassment and/or Level A 
harassment. Neither NSF nor NMFS expects serious injury or mortality to 
result from this activity, nor did NMFS authorize any. Therefore, an 
IHA is appropriate.

Description of Specified Activity

Overview

    The purpose of the project is to construct a replacement pier at 
Palmer Station on Anvers Island, Antarctica for the United States 
Antarctic Program. It is severely deteriorated, and needs to be 
replaced as soon as possible. This project will include construction of 
a new steel pipe pile supported concrete deck pier, new modern energy 
absorbing fender system and on-site power and lighting. Construction of 
the replacement pier and removal of the existing pier will require 
down-the-hole (DTH) pile installation, vibratory hammer pile removal, 
vibratory hammer pile installation, limited impact driving to seat 
piles, rock chipping, and the use of a hydrogrinder. The planned 
project is expected to take up to 89 days of in-water work and will 
include the installation of 52 piles and removal of 36 piles. Due to a 
delay in schedule, in-water construction will now not begin until 
February 2, 2022 and will be completed no later than July 31, 2022. The 
Federal Register notification of the proposed IHA (86 FR 46199: August 
18, 2021) stated that in-water construction would begin in October or 
November 2021, and would be completed by mid-April 2022. A detailed 
description of NSF's activities is provided in the Federal Register 
notification of the proposed IHA (86 FR 46199: August 18, 2021). The 
number of active construction days has not changed and no changes have 
been made to the planned construction activities. Therefore, a detailed 
description is not provided here. Please refer to that Federal Register 
notice for the description of the specific activity.

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to NSF was published in 
the Federal Register on August 18, 2021 (86 FR 46199). That notice 
described, in detail, NSF'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 Ari Friedlaender Ph.D., Institute of Marine Sciences, 
University of California, Santa Cruz. A summary of the commenter's 
recommendations as well as NMFS' responses is below. Please see Dr. 
Friedlaender'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. Dr. Friedlaender commented that several of the proposed 
take requests for marine mammals were based on inaccuracies and did not 
align with basic information on the distribution and abundance of 
animals around Palmer Station. He did not believe that the best 
available information was utilized. Dr. Friedlaender cited several 
research articles which were not contained in the Federal Register 
notification of the proposed IHA, which he felt could be useful in 
determining take of marine mammals.
    Response: NMFS strives to identify and utilize the best available 
scientific information when evaluating potential impacts to marine 
mammals associated with actions described in submitted IHA 
applications. Dr. Friedlaender specifically identified papers by Felix 
et al. (2021), Johnston et al. (2012), and Jackson et al. (2006), as 
being relevant but were not included in the Federal Register 
notification of the proposed IHA.
    Dr. Friedlaender commented that Felix et al. (2021) provided 
population estimates of 11,784 and 11,786 (up from 9,484 in the 
proposed IHA) for the breeding stock of humpback whales (breeding stock 
G) found in the vicinity of Palmer Station which constitutes about 90 
percent of the humpback whale around the Antarctic Peninsula. Other 
stocks make up the remaining and are represented by approximately 10 
percent of the Antarctic Peninsula abundance as presented by Reilly et 
al. (2004). This is considered to be the best available science and, 
therefore, NMFS has updated Table 1 and Table 17 in this notification 
of issuance to reflect the change.
    NSF inadvertently omitted the paper by Johnston et al. (2012) from 
the application. Specifically, due to a word-processing formatting 
error the reference was not included in Table 6-3 of the application, 
although data from that source was used for the humpback whale group 
size estimate in the proposed IHA. The reference has been included in 
this notice. The density for humpback whales referenced in the Johnston 
et al. (2012) paper for Gerlach Strait in the area where Hero Inlet is 
located, is 0.09 whales/square kilometer (km\2\) while the density used 
in the proposed IHA was 0.03 whales/km\2\ (Santora et al., 2009). 
Employing the density of 0.09 whales/km\2\ to estimate takes provides a 
new Level A harassment take estimate for humpback whales of 14.74 
(previously 5.91) and a new Level B harassment take estimate of 302.18 
(previously 121.21) for a total estimate of 317 takes.

[[Page 61143]]

    After the public comment period ended on September 17, Dr. 
Friedlaender provided additional data to NMFS that was collected over a 
5-year period at Palmer Station from January 4, 2015 through March 18, 
2020 (Friedlaender, Personal Communication). Unless otherwise noted, 
personal communications from Friedlaender were either with NSF (which 
NSF then shared with NMFS) or with NMFS. The data was collected between 
January and March/April of each year from small boats, unmanned aerial 
systems (UASs) and land-based surveys. Ninety percent of the surveys 
(424 of 471) took place within the Palmer Station small boating limits 
which covers waters out to 2.5 mi (4 km) from the Station. A small 
number of surveys took place within the extended small boating limits 
which extend out to 25 mi (40 km) from the Station. Up to 3 surveys 
were conducted per day. A total of 671 humpback whales were sighted 
between January and March or April over 5 years, which is an average of 
33.4 animals per month. If it were assumed that the months of December 
and November also had the same average per month, then the total 
estimated take for the planned November-April work period would suggest 
200 animals per year might be encountered in the area. However, to be 
precautionary, NMFS has used the Johnston et al. (2012) data to 
authorize 15 takes by Level A harassment and 302 takes by Level B 
harassment for a total of 317 authorized takes.
    The paper by Jackson et al. (2006) does not provide abundance 
information on breeding stock G. Only breeding stocks E and F are 
included in this analysis. Therefore, it was not included as a 
reference for estimating humpback whale abundance near the Project 
Area.
    NMFS will continue to use the best available scientific 
information, and we welcome future input from interested parties on 
data sources that may be of use in analyzing the potential presence and 
movement patterns of marine mammals potentially impacted by incidental 
take authorizations.
    Comment 2: Dr. Friedlaender questioned the source of the marine 
mammal observation data supplied by NSF from Hero Inlet and nearby 
areas. He indicated that the data does not represent the known 
dedicated marine mammal surveys that have been conducted as part of 
NSF's Long Term Ecological Research (LTER) program since 2015 in this 
exact area. He feels that such information could have provided for a 
more accurate assessment of species abundance and occurrence patterns. 
He noted that these data would demonstrate that the densities of both 
Antarctic minke whales and fin whales are not significantly larger than 
those of humpback whales near Palmer Station as was described in the 
notification of proposed IHA. Therefore, proposed take for minke and 
fin whales should not be higher than for humpback whales.
    Response: The LTER data provided by Friedlaender over five years 
and 369 days worth of effort showed sightings of 671 humpback whales, 
54 Antarctic minke whales, 5 killer whales, 1 southern right whale, 
zero blue whales, zero fin whales, 437 Antarctic fur seals, 22 leopard 
seals, 6 crabeater seals, 4 Weddell seals, and 2 southern elephant 
seals. Given this new information, NMFS agrees that estimates of takes 
for Antarctic minke whales (327) and fin whales (296) are likely 
overestimates of what may actually occur. The difference between is 
likely due to how available density estimates were appropriated. As 
part of the analysis in the proposed IHA if two density estimates 
(nearshore vs. offshore) for a marine mammal population are available, 
NMFS used the higher of two densities to be precautionary when 
estimating potential takes. As described in the notification of the 
proposed IHA, the nearshore density estimates for fin whales are 
significantly overestimated for Palmer Station as the density estimates 
come from surveys (Santora et al., 2009) that occurred in depths that 
favored the nearshore distribution of fin whales in that specific area. 
It was also noted in the notification of the proposed IHA that fin 
whales have not been visually observed from Palmer Station during 
recent years. While approximately 5 Antarctic minke whale observations 
were recorded each year by Friedlaendar, the higher offshore density 
was also used to estimate take for Antarctic minke whales. Friedlaendar 
asserted that the proposed total takes of minke whales (327) and fin 
whales (296) should not be significantly higher than those of humpback 
whales (127). As noted in the previous comment, takes of humpback 
whales have been revised based on Johnston et al. (2021) data and are 
now (317) and authorized take of Antarctica minke whales (327) and fin 
whales (296) are no longer significantly higher. The takes that were 
proposed and are now authorized represent a precautionary approach to 
balance the estimated takes based solely on density and the observation 
data which recorded lower sightings.
    In the absence of any additional data, NMFS has authorized take of 
minke whales and fin whales at the same levels that were determined in 
our preliminary findings in the Federal Register notification of the 
proposed IHA.
    A student from Dr. Friedlaendar's lab provided raw data regarding 
pinniped observations near Palmer station. The data was being used as 
part of the graduate student's thesis. However, the data only covered a 
January to March time period and observations were taken over an area 
larger area than the Level A or Level B harassment zones. Therefore, 
the data was not used.
    Comment 3: Dr. Friedlaender commented that it was difficult to 
comprehend how the Level A and Level B harassment zones were 
calculated. He provided an example of how the area of a circle 
demarcated by the radius of the harassment zone isopleth should be 
split in half since the coast of Anvers Island precludes 180-degrees of 
land leaving 180-degrees of water ensonified.
    Response: The estimated areas (km\2\) that would be ensonified 
above Level A and Level B harassment thresholds for each activity were 
calculated using the distances from Palmer Pier to the harassment 
thresholds for each species. The ensonified areas were determined by 
plotting these isopleths and using GIS to calculate the area within the 
polygons that would be above each threshold level. However, Palmer Pier 
is located in a narrow portion of Hero Inlet and the area potentially 
ensonified above Level A and Level B harassment thresholds is truncated 
by the proximity to land masses in the inlet (i.e., shadow effect). In 
other words, acoustic propagation from the source would be impeded by 
natural features in the water, resulting in acoustic shadows behind 
such features. The areas of truncated land forms were subtracted from 
the combined circular land and water areas to calculate the in-water 
areas (i.e., harassment zones) that are ensonified to Level A and Level 
B harassment thresholds. Therefore, no changes are necessary.
    Comment 4: Dr. Friedlaender expressed concern that the required 
real-time monitoring methods seem inadequate and that animals occurring 
in a specified shutdown zone would not be detected. From personal 
experience in the region, he indicated that surveying the harassment 
zones from a single platform at Palmer Station, while likely to allow 
for seeing large marine mammals, would result in pinnipeds and small 
cetaceans (e.g., minke whales) being missed by protected species 
observers (PSOs). He also suggested using unmanned aerial systems (UAS) 
and placing (PSOs) on nearby islands, in small boats.
    Response: As part of the proposed IHA, NMFS considered some of Dr.

[[Page 61144]]

Friedlaender's concerns about the efficacy of monitoring the large 
Level A and Level B harassment zones from a location at the lab behind 
the pier construction site and we specifically sought additional public 
input on this topic. Regarding the suggestion to employ UASs, NMFS 
asked NSF if this was possible. NSF indicated that operations in 
Antarctica are currently highly restricted due to COVID [protocols]. As 
Palmer Station will be staffed (at maximum capacity [in accordance to 
COVID protocols]) for construction only, rather than science 
operations, it will not have the usual services and staff available to 
support scientific operations (e.g., UAS operations, etc.). UAS 
operations in Antarctica are governed by the Antarctic Treaty and 
Protocol on Environmental Protection to the Antarctic Treaty, including 
domestic laws and regulations implementing its requirements, such as 
the Antarctic Conservation Act (ACA, 16 U.S.C. 2401 et seq.). 
Accordingly, the use of UAS requires experienced operators as well as 
an ACA waste permit (45 CFR part 671). Due to the limited staff 
capacity and thus lack of experienced operators, NSF did not obtain the 
necessary ACA waste permit. Given these circumstances, NMFS concurred 
with NSF's determination that this measure is not practicable. 
Regarding the placement of PSOs on islands in the vicinity of Palmer 
Station, due to life-safety and logistics issues, NSF has determined, 
and NMFS agrees, that it would not be practicable. Such an arrangement 
would require frequent small boat excursions each day, placing the boat 
operators and PSOs at risk. Given the extreme environment in 
Antarctica, weather can change drastically in minutes to an hour, 
potentially leaving PSOs stranded on an island for extended periods and 
putting them at risk.
    Furthermore, this will not be a typical year at Palmer Station due 
to the construction of the new pier and will not be staffed as during a 
normal year. Palmer Station will be staffed to support construction 
activities, not small boating operations. The current pier will be 
demolished in order to build the new one. The normal launch area for 
small boating operations will be in the construction zone and any 
launching of small boats would be extremely difficult and dangerous. 
NSF will also not have the staff capacity or expertise that would be 
necessary to transport PSOs to islands or run frequent small boat 
operations.
    Due to the size of some of the larger harassment zones, NMFS 
acknowledges that the entirety of the shutdown zones in the proposed 
IHA may not be fully visible to PSOs, especially for smaller marine 
mammals. However, NMFS concurs with NSF that the suggested monitoring 
and mitigation measures suggested by Dr. Friedlaender to extend the 
detection range are not practicable at this time. Accordingly, NMFS has 
reduced the shutdown zones (as described in Tables 18 and 19) in all 
instances where the shutdown zones specified in the notification of 
proposed IHA were greater than 1,000 m. This will allow PSO's to 
monitor the shutdown zones with greater efficacy. Animals that are 
observed beyond 1,000-m zones during authorized activities will be 
recorded as having been potentially taken by Level A harassment if they 
are located within the specified Level A harassment zone for that 
species. NMFS will also require NSF to document any marine mammals 
observed within these Level A harassment zones, to the extent 
practicable (noting that some distances to these zones are too large to 
fully observe). Note that the take estimates provided in both the 
notification of proposed IHA and the final IHA were derived assuming 
that there was no monitoring or mitigation. Given the logistical and 
safety challenges present at Palmer Station, NSF believes that the 
required monitoring measures will allow PSOs to adequately observe 
specified shutdown and harassment zones. NMFS agrees with this 
assessment.

Changes From the Proposed IHA to Final IHA

    Table 4 in the notification of proposed IHA incorrectly listed the 
humpback whale as being Endangered under the Endangered Species Act and 
Depleted under the Marine Mammal Protection Act. Those attributes have 
been removed as shown in Table 1 in this notice. The reference for the 
Johnston et al. (2012) paper on humpback whales was inadvertently 
omitted from Table 6-3 in the application, although data on humpback 
whale group size was actually included in that table. Based on the 
recommendation from Dr. Friedlaender to use density findings from 
Johnston et al., (2012), NMFS has utilized the revised humpback whale 
density (0.09 animals/km\2\) resulting in increases of authorized take 
by both Level A and Level B harassment. These changes are described in 
more detail in the response to Comment 1. Recent humpback whale 
abundance data from Felix et al. (2021) was incorporated into this 
notice of issuance and is also described in detail in the response to 
Comment 1. Several of the species abundance estimates contained in 
Table 3 in the proposed IHA were incorrect. As such, abundance 
estimates for Antarctic minke whale, fin whale, and Southern elephant 
seal have been revised. Revisions to Antarctic minke whale and fin 
whale abundances were necessary since the estimates reported Reilly et 
al. (2004) in the proposed IHA (18,125 Antarctic minke whales and 4,672 
fin whales) were based on a survey area that included both the 
Antarctic Peninsula and the Scotia Sea. The changes included in this 
notice (7,395 Antarctic minke whales and 1,492 fin whales) include data 
from only the Antarctic Peninsula survey area which is more 
representative of animal abundance near the Project Area. The abundance 
estimate published in the proposed IHA for Southern elephant seals 
(401,572) was incorrect. The actual abundance estimate is 413,671 
according to Hindell et al. (2016).
    NMFS had incorrectly listed only one proposed take of leopard seal 
by Level B harassment in Table 20 of the Federal Register notification 
of proposed IHA. The text clearly indicates that NMFS was proposing 
five takes by Level B harassment, in addition to the five authorized 
takes by Level A harassment. However, as described below authorized 
take of leopard seals has been increased above those presented in the 
notification of proposed IHA. These updates are based on the new in-
water project schedule starting on February 2, 2022 and extending to 
July 31, 2022. The original schedule contained in the notification of 
proposed IHA had the project running from October/November through 
April. Also, the observational data submitted to NMFS that was used to 
develop pinniped take estimates was found to contain errors. NMFS 
requested that NSF submit the correct data and reassessed the pinniped 
take estimates for this notice. Revisions are described in the detail 
in the section Marine Mammal Occurrence and Take Estimation.
    In cases where species' abundance estimates have changed the 
corresponding percentage of stock potentially affected has also been 
revised. Species where the percentages changed include humpback whale 
(from 1.34 to 2.69), Antarctic minke whale (from 1.80 to 4.42), and fin 
whale (from 6.33 to 19.84). Take revisions based on a reassessment of 
the corrected pinniped observational data resulted in increases in 
percentage of stock potentially taken for Southern elephant seals (from 
<0.01 to 0.23), Antarctic fur seals (0.02 to 0.05), Weddell seals (from 
0.04 to 0.05), and Leopard seals (from <0.01 to 0.06). These revisions 
are

[[Page 61145]]

included in Table 17 of this notice. Finally, NMFS will now require the 
implementation and monitoring of a 1,000-m shutdown zone in every 
instance where the specified shutdown zone for a hearing group for a 
given activity was originally proposed to be greater than 1,000 m.

Description of Marine Mammals in the Area of Specified Activities

    There are 17 species in the Project Area for which NMFS has 
authorized take. Sections 3 and 4 of NSF'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).
    Table 1 lists all species or stocks for which take has been 
authorized, and summarizes best available information on the population 
or stock, including regulatory status under the MMPA and Endangered 
Species Act. For taxonomy, we follow Committee on Taxonomy (2020). 
Marine mammals in the Project Area do not constitute stocks under U.S. 
jurisdiction; therefore, there are no stock assessment reports. 
Additional information on these species may be found in Section 3 of 
NSF's application.
    For species occurring near the Antarctic Peninsula the 
International Union for the Conservation of Nature (IUCN) status is 
provided. The IUCN systematically assesses the relative risk of 
extinction for terrestrial and aquatic plant and animal species via a 
classification scheme using five designations, including three 
threatened categories (Critically Endangered, Endangered, and 
Vulnerable) and two non-threatened categories (Near Threatened and 
Least Concern) (www.iucnredlist.org/; accessed June 10, 2021). These 
assessments are generally made relative to the species' global status, 
and therefore may have limited applicability when marine mammal stocks 
are defined because we analyze the potential population-level effects 
of the specified activity to the relevant stock. However, where stocks 
are not defined, IUCN status can provide a useful reference.

                 Table 1--Marine Mammals Potentially Present in the Vicinity of the Project Area
----------------------------------------------------------------------------------------------------------------
                                                                         ESA/MMPA/IUCN
         Common name            Scientific name        Stock \2\          status \3\        Abundance (CV) \4\
----------------------------------------------------------------------------------------------------------------
                      Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
----------------------------------------------------------------------------------------------------------------
Family Balaenidae (right
 whales):
    Southern right whale.....  Eubalaena         ....................  E/D/LC                   \5\ 1,755 (0.62)
                                australis.
Family Balaenopteridae
 (rorquals):
    Humpback whale...........  Megaptera         ....................  -/LC                          \15\ 12,486
                                novaeangliae
                                australis.
    Antarctic minke whale....  Balaenoptera      ....................  -/NT                    \ 5\ 7,395 (0.36)
                                bonaerensis.
    Fin whale................  B. physalus       ....................  E/D/VU                   \5\ 1,492 (0.57)
                                quoyi.
    Blue whale...............  B. musculus       ....................  E/D/EN                         \13\ 1,700
                                musculus.
    Sei whale................  Balaenoptera      ....................  E/D/EN                           \14\ 626
                                borealis.
----------------------------------------------------------------------------------------------------------------
                        Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
----------------------------------------------------------------------------------------------------------------
Family Physeteridae:
    Sperm whale..............  Physeter          ....................  E/D/VU                  \7\ 12,069 (0.17)
                                macrocephalus.
Family Ziphiidae (beaked
 whales):
    Arnoux's beaked whale....  Berardius         ....................  /DD                               unknown
                                arnuxii.
    Southern bottlenose whale  Hyperoodon        ....................  -/LC                    \8\ 53,743 (0.12)
                                planifrons.
Family Delphinidae:
    Hourglass dolphin........  Lagenorhynchus    ....................  -/LC                   \9\ 144,300 (0.17)
                                cruciger.
    Killer whale.............  Orcinus orca\1\.  ....................  -/DD                    \8\ 24,790 (0.23)
    Long-finned pilot whale..  Globicephala      ....................  -/LC                   \9\ 200,000 (0.35)
                                melas edwardii.
----------------------------------------------------------------------------------------------------------------
                                     Order Carnivora--Superfamily Pinnipedia
----------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and sea lions):
    Antarctic fur seal.......  Arctocephalus     South Georgia.......  -/LC                       \10\ 2,700,000
                                gazella.
Family Phocidae(earless
 seals):-
    Southern elephant seal...  Mirounga leonina  South Georgia.......  -/LC                         \11\ 413,671
    Weddell seal.............  Leptonychotes     ....................  -/LC               \12\ 500,000-1,000,000
                                weddellii.
    Crabeater seal...........  Lobodon           ....................  -/LC                      \12\ 5,000,000-
                                carcinophaga.                                                         10,000,000
    Leopard seal.............  Hydrurga          ....................  -/LC                 \12\ 222,000-440,000
                                leptonyx.
----------------------------------------------------------------------------------------------------------------
\1\ Three distinct forms of killer whale have been described from Antarctic waters; referred to as types A, B,
  and C, they are purported prey specialists on Antarctic minke whales, seals, and fish, respectively (Pitman
  and Ensor, 2003; Pitman et al., 2010).
\2\ For most species in the AMLR, stocks are not delineated and entries refer generally to individuals of the
  species occurring in the research area.
\3\ 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. Any species
  listed under the ESA is automatically designated under the MMPA as depleted. IUCN status: Endangered (EN),
  Vulnerable (VU), Near Threatened (NT), Least Concern (LC), Data Deficient (DD).
\4\ CV is coefficient of variation. All abundance estimates, except for those from Reilly et al.,(2004) (right,
  humpback, minke, and fin whales), are for entire Southern Ocean (i.e., waters south of 60[deg]S) and not the
  smaller area comprising the Southwest Fisheries Science Center (SWFSC) research area.
\5\ Abundance estimates reported in Reilly et al.,(2004) for the Commission for the Conservation of Antarctic
  Marine Living Resources (CCAMLR) survey area from 2000. This value has been revised to include abundance in
  only the Antarctic Peninsula and excluded the Scotia Sea as part of the Survey Area which was shown in the
  proposed IHA.

[[Page 61146]]

 
\6\ Southern Ocean abundance estimate (Branch et al., 2007).
\7\ Southern Ocean abundance estimate (IWC, 2001 in Whitehead, 2002).
\8\ Southern Ocean abundance estimate from circumpolar surveys covering 68 percent of waters south of 60[deg]S
  from 1991-98 (Branch and Butterworth, 2001).
\9\ Southern Ocean abundance estimate derived from surveys conducted from 1976-88 (Kasamatsu and Joyce, 1995).
\10\ South Georgia abundance estimate; likely >95 percent of range-wide abundance (Forcada and Staniland, 2009).
  Genetic evidence shows two distinct population regions, likely descended from surviving post-sealing
  populations at South Georgia, Bouvet[oslash]ya, and Kerguelen Islands (Wynen et al., 2000; Forcada and
  Staniland, 2009). Individuals from the South Georgia population (including breeding populations at the South
  Orkney and South Shetland Islands, which are within the ARA) are likely to occur in the ARA.
\11\ The abundance figure provided in the proposed IHA was incorrect. The correct abundance is included in this
  Table (Hindell et al., 2016).
\12\ Range-wide abundance estimates (Thomas and Terhune, 2009; Bengtson, 2009; Rogers, 2009).
\13\ Southern Ocean abundance estimate (Branch et al., 2007).
\14\ South of 60[deg]S from NOAA (2015).
\15\ Felix et al., 2021. Population estimate for the humpback whale Breeding Stock G (BSG), defined by feeding
  grounds around the Antarctic Peninsula. Approximately 90% of humpback whales in Antarctic Peninsula are from
  BSG (Friedlaender, Personal Communication). Approximately 10% of Antarctic Peninsula abundance from Reilly et
  al.)2004) represents remaining.

    A detailed description 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 notice for the proposed IHA. Since 
that time, we are not aware of any changes in the status of these 
species and stocks. As noted previously, the term ``pile driving'' 
(unless otherwise specified) is used to refer to both pile installation 
(including DTH pile installation) and pile removal.
    Therefore, detailed descriptions are not provided here. Please 
refer to that Federal Register notice for these descriptions.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The Federal Register notification of the proposed IHA (86 FR 46199; 
August 18, 2021) included a discussion of the effects of anthropogenic 
noise on marine mammals and the potential effects of underwater noise 
from NSF'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 
proposed IHA. No new data is available that suggests the potential 
responses and impacts to marine mammals would differ from those 
discussed in the notification 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. As noted 
above, some take estimates have changed since the proposed IHA, and 
those changes are described in the Marine Mammal Occurrence and Take 
Estimation section below.
    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 use of 
the acoustic sources (i.e., pile installation and removal equipment) 
has the potential to result in disruption of behavioral patterns for 
individual marine mammals. There is also some potential for auditory 
injury (Level A harassment) to result, primarily for mysticetes due to 
large PTS zones as well as for phocids and otariids due to haulouts in 
the vicinity of the Project Area. Auditory injury is unlikely to occur 
for high frequency or mid-frequency species. The required mitigation 
and monitoring measures are expected to minimize the severity of the 
taking to the extent practicable.
    As described previously, no mortality or serious injury is 
anticipated or authorized for this activity. Below we describe how the 
take is estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and (4) and 
the number of days of activities. We note that while these 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 [mu]Pa (rms) for continuous (e.g., 
vibratory pile-driving, DTH) and above 160 dB re 1 [mu]Pa (rms) for 
non-explosive impulsive (e.g., seismic airguns, impact pile driving) or 
intermittent (e.g., scientific sonar) sources.
    DTH pile installation includes drilling (non-impulsive sound) and 
hammering (impulsive sound) to penetrate rocky substrates (Denes et 
al., 2016; Denes et al., 2019; Reyff and Heyvaert 2019). DTH pile 
installation was initially thought to be a primarily non-impulsive 
noise source. However, Denes et al.,

[[Page 61147]]

(2019) concluded from a study conducted in Virginia, that DTH pile 
installation should also be characterized as impulsive based on 
Southall et al., (2007), who stated that signals with a >3 dB 
difference in sound pressure level in a 0.035-second window compared to 
a 1-second window can be considered impulsive. Therefore, DTH pile 
installation is treated as both an impulsive and non-impulsive noise 
source. In order to evaluate Level A harassment, DTH pile installation 
activities are evaluated according to the impulsive criteria and using 
160 dB rms. Level B harassment isopleths for DTH are determined by 
applying non-impulsive criteria and using the 120 dB rms threshold 
which is also used for vibratory driving. This approach ensures that 
the largest ranges to effect for both Level A and Level B harassment 
are accounted for in the take estimation process for DTH.
    NSF's planned activity includes the use of continuous (vibratory 
hammer, DTH pile installation, hydrogrinder) and impulsive (impact pile 
driving, DTH pile installation) sources, and therefore the 120 and 160 
dB re 1 [mu]Pa (rms) is/are applicable.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Version 2.0) (Technical Guidance, 2018) identifies dual 
criteria to assess auditory injury (Level A harassment) to five 
different marine mammal groups (based on hearing sensitivity) as a 
result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). NSF's planned activity includes the use 
of impulsive (i.e. impact hammer, DTH pile installation) and non-
impulsive (i.e., vibratory hammer, DTH pile installation, rock 
chipping, hydrogrinder) sources.
    These thresholds are provided in Table 2. 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 2--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.
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 sound field in the Project Area is the existing background 
noise plus additional in-water construction noise from the planned 
project. Marine mammals are expected to be affected via sound generated 
by the primary components of the project (i.e., DTH pile installation, 
vibratory pile removal, limited impact for proofing purpose, rock 
chipping and use of hydrogrinders).
    The estimated sound source levels (SSL) proposed by NSF and 
utilized by NMFS in this assessment are described below and are shown 
in Table 3. Appendix A in the application discusses in detail the sound 
source levels for all planned equipment. Sound levels from pile 
installation used in NSF's application came from the Caltrans 
Compendium (2015) or are based on empirical data collected from other 
sites with similar conditions (e.g., rock substrate where DTH driving 
would be used to install piles). NSF referenced two studies to arrive 
at SSLs for 24-in DTH pile installation. Noise studies from Kodiak 
ferry terminal (Denes et al., 2016) and Skagway cruise ship terminal 
(Reyff and Heyvart, 2019; Reyff, 2020). Results are shown in Table 3. 
NMFS has developed DTH pile installation guidelines which contain 
recommendations for appropriate SSLs. NSF applied these recommendations 
for 36-in DTH pile installation. However, NSF proposed to use the DTH 
pile installation SSLs shown in Table 3, which, for 24-in DTH pile 
installation and 24-in sockets, are more conservative than those 
recommended by NMFS, and NMFS deemed this approach acceptable.
    NSF determined the SSLs for rock chipping based on underwater 
sounds measured for concrete demolition. NSF examined two sets of data 
available during the demolition of the Tappan Zee Bridge (state of New 
York) pier structures. NSF also considered the results from another 
study conducted by the Washington State Department of Transportation 
(WSDOT). Results from that analysis are shown in Table 3.
    The U.S. Navy has assessed sound levels of the use of a 
hydrogrinder through underwater measurements (U.S. Navy 2018). The Navy 
measurements were reported in 1/1-octave frequency bands from 125 to 
8,000 Hz for the helmet position that was assumed to be 0.5 to 1 meter 
(m) from the hydraulic grinder operation. The overall unweighted sound 
level was computed to be 167.5 dB at 0.5 to 1 m. Source sound levels in 
this report are provided for 10-m distances. Since this is a point 
source of sound, spherical spreading 20 Log TL coefficient results in a 
source

[[Page 61148]]

sound level of 142 to 148 dB at 10 m (see Appendix A in the 
application). A value of 146 dB at 10 m has been used to estimate 
marine mammal take associated with these tools.
    NSF assumed that installation of approximately one to two piles 
would occur over a 12-hour work day. To be precautionary in calculating 
isopleths, this application assumes two installation activities would 
occur simultaneously. For example, two 36-in piles installed 
simultaneously or one 36-in pile and one 24-in pile. Brief impact pile 
driving of about 10 strikes may be used to seat the piles. A likely 
approach to installing 36-in piles would be to use DTH to install two 
36-in piles simultaneously; one 36-in pile would be installed to 20-ft 
socket depth while a second 36-in abutment pile would be installed to a 
30-ft socket depth. The abutment piles require additional depth to 
support lateral loads and to provide side friction against ice uplift 
that could occur at the shoreline. It is also possible that both 36-in 
piles may be installed simultaneously to 20-ft socket.
    Rock chipping may be required to level pile areas and would 
normally occur on the same day as DTH pile installation, if possible. 
If rock chipping is conducted separately from DTH pile installation, 
takes are accounted for by using the area ensonified during DTH pile 
installation to calculate takes. This precautionary approach 
overestimates takes that could occur if only rock chipping is conducted 
by itself. Rock chipping is considered to be an impulsive source.
    Existing sheetpile will be removed through vibratory extraction. In 
some instances it may be necessary to remove piles by cutting them off 
at the mudline using underwater hand cutting tools. Such activity would 
occur on the same days as vibratory extraction. Cutting piles off at 
the mudline would result in less underwater noise than vibratory 
removal. To be precautionary, estimated marine mammal takes were 
calculated by assuming all piles were removed by vibratory extraction.

                                          Table 3--Sound Source Levels
----------------------------------------------------------------------------------------------------------------
                                   Measured sound levels \1\
-----------------------------------------------------------------------------------------------      Source
           Activity                  Peak             RMS           SEL \2\           TL
----------------------------------------------------------------------------------------------------------------
                                                   24-in Piles
----------------------------------------------------------------------------------------------------------------
DTH pile installation.........             190             166             154              15  Denes et al.,
                                                                                                 (2016).
Vibratory Driving \4\.........             170             165             165              15  Caltrans (2015).
Impact Driving................             195             181             168              15  Caltrans (2015).
----------------------------------------------------------------------------------------------------------------
                                                   36-in Piles
----------------------------------------------------------------------------------------------------------------
DTH pile installation.........             194             166             164              15  The DTH sound
                                                                                                 source proxy of
                                                                                                 164 dB SEL is
                                                                                                 from 42-in
                                                                                                 piles, Reyff
                                                                                                 (2020) and
                                                                                                 Denes et al.,
                                                                                                 (2019).
Vibratory Driving.............             180             170             170              15  Caltrans (2015).
Impact Driving................             210             193             183              15  Caltrans (2015).
----------------------------------------------------------------------------------------------------------------
                                       H Piles inserted in 24-in. Sockets
----------------------------------------------------------------------------------------------------------------
DTH pile installation.........             190             166             154              15  Denes et al.,
                                                                                                 (2016).
Vibratory Driving.............             170             165             165              15  Caltrans (2015).
Impact Driving................             195             180             170              15  Caltrans (2015).
----------------------------------------------------------------------------------------------------------------
                                         Removal of 24-in Template Piles
----------------------------------------------------------------------------------------------------------------
Vibratory Driving.............             170             165             165              15  Caltrans (2015).
----------------------------------------------------------------------------------------------------------------
                                             Removal of Sheet Piles
----------------------------------------------------------------------------------------------------------------
Vibratory Driving.............             175             160             160              15  Caltrans (2015).
----------------------------------------------------------------------------------------------------------------
                                                  Rock Chipping
----------------------------------------------------------------------------------------------------------------
Hydraulic Breaker.............             197             184             175              22  Tappan Zee
                                                                                                 Bridge.\6\ \7\
----------------------------------------------------------------------------------------------------------------
                                               Anode Installation
----------------------------------------------------------------------------------------------------------------
Hydro-grinder.................  ..............             146  ..............              20  U.S. Navy
                                                                                                 (2008).
----------------------------------------------------------------------------------------------------------------
\1\ See Appendix A in application for references and discussion of all sound sources.
\2\ SEL is single strike for impact driving and DTH pile installation. SEL for vibratory installation is per
  second.
\4\ Includes removal of 24-in. piles.
\5\ While it is possible the socket depth would be only 20 ft, this application assumes the greater depth to be
  precautionary.
\6\ Reyff, J. 2018. Demolition of Existing Tappan Zee Bridge. Summary of Underwater Sound Measurements for
  Mechanical Demolition of Concrete Pile Caps at Piers 114 and 115, Circular Caisson at Pier 166, and
  Rectangular Caisson at Pier 170. To David Capobianco, New York State Thruway Authority. December 18, 2020.
\7\ Reyff, J. 2018. Demolition of Existing Tappan Zee Bridge Subject: Summary of Underwater Sound Measurements
  for Mechanical Demolition of Ice Breakers at Piers 173 and 169. To Kristine Edwards, New York State Thruway
  Authority. January 10, 2018.

    When the sound fields from two or more concurrent pile installation 
activities overlap, the decibel addition of continuous noise sources 
results in much larger zone sizes than a single source. Decibel 
addition is not a

[[Page 61149]]

consideration when sound fields do not overlap. The increased SLs 
potentially associated with two concurrent sources with overlapping 
sound fields are shown in Table 4 (WSDOT 2015). Decibel addition is 
only applicable to continuous sources. According to NMFS guidance the 
SL for continuous sounds from DTH pile installation is 166 dB 
regardless of the size of the pile. Under decibel addition, 
simultaneous DTH pile installation activities would use a SL of 169 
(166 + 3) to derive the isopleth for the Level B harassment zone.

                                  Table 4--Simultaneous Source Decibel Addition
----------------------------------------------------------------------------------------------------------------
                                                                    Level A harassment      Level B harassment
            Hammer types                  Difference in SSL                zones                   zones
----------------------------------------------------------------------------------------------------------------
Vibratory, Impact..................  Any........................  Use impact zones......  Use largest zone.
Impact, Impact.....................  Any........................  Use zones for each      Use zone for each pile
                                                                   pile size and number    size.
                                                                   of strikes.
Vibratory, Vibratory...............  0 or 1 dB..................  Add 3 dB to the higher  Add 3 dB to the higher
                                                                   source level.           source level.
                                     2 or 3 dB..................  Add 2 dB to the higher  Add 2 dB to the higher
                                                                   source level.           source level.
                                     4 to 9 dB..................  Add 1 dB to the higher  Add 1 dB to the higher
                                                                   source level.           source level.
                                     10 dB or more..............  Add 0 dB to the higher  Add 0 dB to the higher
                                                                   source level.           source level.
----------------------------------------------------------------------------------------------------------------

Level B Harassment Zones

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

TL = B * Log10 (R1/R2),

where:

TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement

    The recommended TL coefficient for most nearshore environments is 
the practical spreading value of 15. This value results in an expected 
propagation environment that would lie between spherical and 
cylindrical spreading loss conditions, which is the most appropriate 
assumption for NSF's planned activity in the absence of specific 
modelling. Level B harassment isopleths are shown in Table 11 and Table 
12.

Level A Harassment Zones

    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 those 
planned for this project, 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. Tables 7, 
8 and 9 show User inputs for single sound sources while Tables 10, 11, 
and 12 contain User inputs for simultaneous sources. The resulting 
Level A harassment isopleths for non-simultaneous activities and 
simultaneous activities are shown in Table 11 and Table 12 
respectively. Level B harassment isopleths for simultaneous DTH pile 
installation utilize a 169 dB SL and corresponding isopleths are shown 
in Table 12. Note that strike numbers for DTH pile installation were 
derived by applying the duration required to drive a single pile 
(minutes), the number of piles driven per day, and the strike rate 
(average strikes per second) rates to arrive at the total number of 
strikes in a 24-hour period. A rate of 10 strikes per second was 
assumed.

 Table 5--NMFS Technical Guidance (2020) User Spreadsheet Inputs To Calculate PTS Isopleths for Non-Simultaneous Vibratory Pile Installation Activities
                                                                    and Hydrogrinding
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                              Anode
                               36-in (dock dock     RHIB fender     24-in template      24-in wave      24-in template     Sheet pile      installation
                                 abutment)-in       piles 24-in       10' socket     attenuator piles-   pile removal       removal          (hydro-
                                                                                            in                                              grinding)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used.........  (A.1) Non-Impul,  (A.1) Non-Impul,  (A.1) Non-Impul,  (A.1) Non-Impul,  (A.1) Non-       (A.1) Non-       (A.1) Non-
                                Stat, Cont.       Stat, Cont.       Stat, Cont.       Stat, Cont.       Impul, Stat,     Impul, Stat,     Impul, Stat,
                                                                                                        Cont.            Cont.            Cont.
Source Level (SPL RMS).......  170.............  165.............  165.............  165.............  165............  160............  146.
15Transmission Loss            15..............  15..............  15..............  15..............  15.............  15.............  20.
 Coefficient.
Weighting Factor Adjustment    2.5.............  2.5.............  2.5.............  2.5.............  2.5............  2.5............  2.5.
 (kHz).
Time to install/remove single  30..............  30..............  30..............  30..............  30.............  30.............  120.
 pile (minutes).
Piles to install/remove per    1...............  1...............  2...............  1...............  16.............  16.............  1.
 day.
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 61150]]


 Table 6--NMFS Technical Guidance (2020) User Spreadsheet Input To Calculate PTS Isopleths for Non-Simultaneous
                                       Impact Pile Installation Activities
----------------------------------------------------------------------------------------------------------------
                                          36-in (dock, dock      24-in RHIB (template,
                                              abutment)             wave attenuator)          Rock chipping
----------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used.................  (E.1) Impact pile        (E.1) Impact pile        (E) Stationary Source:
                                        driving.                 driving.                 Impulsive,
                                                                                          Intermittent.
Source Level (Single Strike/shot SEL)  183....................  168....................  197.
Transmission Loss Coefficient........  15.....................  15.....................  22.
Weighting Factor Adjustment (kHz)....  2......................  2......................  0.
Number of pulses in 1-hr period......  10.....................  10.....................  2,700.
Piles per day........................  1......................  1......................
----------------------------------------------------------------------------------------------------------------


 Table 7--NMFS Technical Guidance (2020) User Spreadsheet Input To Calculate PTS Isopleths for Non-Simultaneous
                                        DTH Pile Installation Activities
----------------------------------------------------------------------------------------------------------------
                                                                Dock abutment-36-in 30'   24-in RHIB, template,
                                        36-in dock 20' socket            socket              wave attenuator
----------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used.................  (E.2) DTH Pile Driving.  (E.2) DTH Pile Driving.  (E.2) DTH Pile Driving.
Source Level (Single Strike/Shot SEL)  164....................  164....................  154.
Transmission Loss Coefficient........  15.....................  15.....................  15.
Strike rate (Strikes/sec)............  10.....................  10.....................  10.
Duration (min).......................  345....................  518....................  345.
Weighting Factor Adjustment (kHz)....  2......................  2......................  2.
Strikes/pile.........................  207,000................  310,500................  207,000.
Piles to install/remove per day......  1......................  1......................  1.
----------------------------------------------------------------------------------------------------------------


    Table 8--NMFS Technical Guidance (2020) User Spreadsheet Input To Calculate PTS Isopleths for Simultaneous Vibratory Pile Installation Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                      36-in dock 20' socket   RHIB fender piles 24-    24-in template 10'   24-in wave attenuator  24-in wave attenuator
                                        x 2 dock abutment            in x 2                socket x 4        piles-10' socket x 2   piles-20' socket x 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used...............  (A.1) Non-Impul, Stat,  (A.1) Non-Impul, Stat,  (A.1) Non-Impul,       (A.1) Non-Impul,       (A.1) Non-Impul,
                                      Cont..                  Cont..                  Stat, Cont..           Stat, Cont..           Stat, Cont.
Source Level (SPL RMS).............  173...................  168...................  168..................  168..................  168.
Transmission Loss Coefficient......  15....................  15....................  15...................  15...................  15.
Weighting Factor Adjustment (kHz)..  2.5...................  2.5...................  2.5..................  2.5..................  2.5.
Time to install/remove single pile   30....................  30....................  15...................  30...................  30.
 (minutes).
Piles to install/remove per day....  2.....................  2.....................  4....................  2....................  2.
--------------------------------------------------------------------------------------------------------------------------------------------------------


   Table 9--NMFS Technical Guidance (2020) User Spreadsheet Input To Calculate PTS Isopleths for Simultaneous
                                       Impact Pile Installation Activities
----------------------------------------------------------------------------------------------------------------
                                    36-in (dock 20'
                                    socket x 2) or                                                24-in wave
                                   dock abutment-36-   RHIB fender piles  24-in template 10'  attenuator piles x
                                    in 30' and 20'         24-in x 2          socket x 4               2
                                        socket
----------------------------------------------------------------------------------------------------------------
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  183...............  168...............  168...............  168.
 SEL).
Transmission Loss Coefficient...  15................  15................  15................  15.
Weighting Factor Adjustment       2.................  2.................  2.................  2.
 (kHz).
Strikes/pile....................  10................  10................  10................  10.
Piles per day...................  2.................  2.................  4.................  2.
----------------------------------------------------------------------------------------------------------------


 Table 10--NMFS Technical Guidance (2020) User Spreadsheet Input To Calculate PTS Isopleths for Simultaneous DTH
                                          Pile Installation Activities
----------------------------------------------------------------------------------------------------------------
                                                                                                  24-in wave
                                                       Dock abutment-36-                       attenuator piles-
                                    36-in dock 20'      in 30' and 20'    24-in template 10'    10' socket x 2/
                                      socket x 2            socket            socket x 4       RHIB fender piles
                                                                                                   24-in x 2
----------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used............  (E.2) DTH Pile      (E.2) DTH Pile      (E.2) DTH Pile      (E.2) DTH Pile
                                   Driving.            Driving.            Driving.            Driving.
Source Level (Single Strike/Shot  164...............  164...............  154...............  154.
 SEL).
Transmission Loss Coefficient...  15................  15................  15................  15.
Strike rate (Strikes/sec).......  10................  10................  10................  10.

[[Page 61151]]

 
Duration (min)..................  345...............  430...............  172.5.............  345.
Weighting Factor Adjustment       2.................  2.................  2.................  2.
 (kHz).
Strikes/pile....................  414,000...........  517,500...........  103,500...........  207,000.
Piles to install per day........  2.................  2.................  4.................  2.
----------------------------------------------------------------------------------------------------------------


                          Table 11--Level A and Level B Harassment Isopleths for Non-Simultaneous Pile Installation Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                        Level A harassment zones (m) based on SELcum
                                                                                  -------------------------------------------------------     Level B
                                                                                              Cetaceans                   Pinnipeds         harassment
                                                                                  -------------------------------------------------------    zone (m)
                                                                                       LF         MF         HF         PW         OW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dock, 36-in Dia. Pile Installation, 20'     DTH Pile Drilling....................      1,891         67      2,253      1,012         74          11,659
 Socket Depth--1 pile/day.
Dock Abutment, 36-in Dia. Pile              DTH Pile Drilling....................      2,478         88      2,951      1,326         97          11,659
 Installation, 30' Socket Depth--1 pile/
 day.
RHIB Fender Piles, 24-in Dia. Pile          DTH Pile Drilling....................        407         15        485        218         16          11,659
 Installation, 20' Socket--1 pile/day.
24-in Dia. Template Piles, 10' Socket       DTH Pile Drilling....................        407         15        485        218         16          11,659
 Depth--2 piles/day.
24-in Dia. Wave Attenuator Piles, 20'       DTH Pile Drilling....................        407         15        485        218         16          11,659
 Socket Depth--1 pile/day.
Retaining Wall HP Pile inserted in Drilled  DTH Pile Drilling....................        407         15        485        218         16          11,659
 24-in Dia. Sockets, 20' Socket Depth--1
 pile/day.
Removal of 24-in Dia. Template Piles--16    Vibratory............................         51          5         75         31          2          10,000
 piles.
Removal of Sheet Piles....................  Vibratory............................         23          2         35         14          1           4,642
Rock Chipping/Floor Preparation...........  Hydraulic Breaker....................        403         50        716        204         29             123
Anode Installation........................  Hydrogrinder.........................        1.9        0.3        2.5        1.3        0.2             200
--------------------------------------------------------------------------------------------------------------------------------------------------------


                            Table 12 --Level A and Level B Harassment Isopleths for Simultaneous Pile Installation Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                        Level A harassment zones (m) based on SELcum
                                                                                  -------------------------------------------------------     Level B
        Daily activity scenario                     Installation method                       Cetaceans                   Pinnipeds         harassment
                                                                                  -------------------------------------------------------    zone (m)
                                                                                       LF         MF         HF         PW         OW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dock, 36-in Dia. Pile Installation, 20'  DTH Pile Installation...................      3,002        107      3,576      1,607        117          18,478
 Socket Depth--2 pile/day.
Dock Abutment, 36-in Dia. Pile                                                         3,484        124      4,149      1,864        136          18,478
 Installation, 30' Socket Depth and 36-
 in Dia. Pile 20' Socket Depth.
RHIB Fender Piles, 24-in Dia. Pile                                                       647         23        770        346         25          18,478
 Installation, 20' Socket--2 pile/day.
24-in Dia. Template Piles, 10' Socket
 Depth--4 piles/day..
24-in Dia. Wave Attenuator Piles, 20'
 Socket Depth--2 pile/day..
Retaining Wall--HP Pile inserted in
 Drilled 24-in Dia. Sockets, 20' Socket
 Depth--2 piles/day..
Dock, 36-in Dia. Pile Installation, 20'                                                2,011         72      2,395      1,076         78          18,478
 Socket Depth--1 pile/day and Wave
 Attenuator, 24-in Dia. Pile
 Installation, 20' Socket--1 pile/day.
Dock 36-in Dia. Pile Installation 30'                                                  2,885        103      3,436      1,544        133          18,478
 Socket Depth and 24-in Dia. Pile
 Installation 20' Socket Depth.
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in Dock 20' socket x 2 Dock Abutment  Vibratory Installation..................         43          4         64         26          2          34,146
RHIB Fender Piles 24-in x 2............                                                   20          2         30         12          1          15,849
24-in template 10' socket 4............
24-in wave attenuator piles-10' socket                                                  31.8          3         47         19        1.4
 x 2.
24-in wave attenuator piles-20' socket
 x 2..
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The calculated area ensonified by single or multiple pile 
installation and removal sound sources is calculated based on the 
distance from the Palmer Station Pier installation location to the edge 
of the isopleth for Level B harassment and for each hearing group for 
Level A harassment. The scenario with the largest zone is used to 
estimate potential marine mammal exposures and those areas are shown in 
Table 13. The Palmer Station Pier is located in a narrow portion of 
Hero Inlet and the areas potentially ensonified above Level A and Level 
B harassment thresholds is truncated by the location of land masses 
including assorted islands (i.e., shadow effect).
    Table 12 shows the construction scenario (installation of two 36-in 
piles, one at 30- ft and a second at 20-ft socket depth) that results 
in the largest PTS zone isopleths while Table 13 shows the areas of the 
corresponding zones ensonified areas. The maximum Level A harassment 
distance would be 1,864 m (1.4 km\2\) for phocids in water (PW), 3,484 
m (3.38 km\2\) for LF cetaceans, and 4,149 m (4.4 km\2\) for HF 
cetaceans (although HF cetaceans are considered

[[Page 61152]]

rare in the Project Area and Level A harassment takes are not 
authorized). The largest Level B harassment isopleth is associated with 
simultaneous DTH pile installation and would be at a distance of 18,478 
m from the source covering an area of 54.99 m.

                          Table 13--Harassment Zone Areas Used for Take Estimation \1\
----------------------------------------------------------------------------------------------------------------
                                                                                                   Level B area
             Pile type                Total piles      Level A max area       Level A max area      all species
                                                    cetaceans \3\ (km\2\)  pinnipeds \3\ (km\2\)      (km\2\)
----------------------------------------------------------------------------------------------------------------
36-in piles (one @30-ft socket                  18  3.38 (LF), 4.4 (HF),   1.4 (PW), 0.03 (OW)..           54.99
 depth and one @20-ft socket                         0.03 (MF).
 depth).
32-in piles (Bent 1)..............               4
Pile Removal (24-in)..............              16  0.006 (LF), 0.012      0.002 (PW)...........           20.78
                                                     (MF), ~0 (MF).
Sheetpile Removal.................              20  0.001 (LF), 0.003      0.0006 (PW)..........            5.27
                                                     (HF), ~0 (MF).
Anode Installation................             n/a  n/a..................  n/a..................            0.07
Rock Chipping.....................             unk
                                   -----------------------------------------------------------------------------
    Total.........................              88
----------------------------------------------------------------------------------------------------------------
\1\ Assumes simultaneous installation (i.e., two pile installations occurring at the same time).

Marine Mammal Occurrence and Take Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that have informed the 
take calculations.
    The approach by which the information provided above is brought 
together to produce a quantitative take estimate is described here. For 
marine mammals with known density information estimated harassment take 
numbers are calculated using the following equation (summed across each 
type of activity):

Estimated take = animal density x ensonified area x operating days

    For some species observational data is also available and is used 
to estimate take. When both density and observational data are 
available for a given species, NMFS used the higher of the two values. 
NMFS used the most conservative option for estimating ensonified area 
for each activity as well as the most conservative estimates of the 
number of days of work for each activity. Note that the take estimates 
described below do not take mitigation and monitoring measures into 
account.
    Takes were estimated by considering the density of marine mammals 
per km\2\ multiplied by the potential area ensonified (km\2\) and the 
number of days the noise could occur during in-water construction. The 
Project Area is located in the nearshore environment relative to the 
Antarctic Peninsula as defined by data reported in Santora et al. 
(2009). Sources for density data and average group sizes are found in 
Table 6-3 in the application.
    Note that a reference for Johnston et al. (2012) regarding humpback 
whales was inadvertently omitted from Table 6-3 in the application. The 
reference was used to determine average humpback whale group size. Dr. 
Friedlaender recommended that the humpback whale density (0.09 animals/
km\2\) provided in that paper be used to estimate take of humpback 
whales. NMFS agrees with this revision and authorized take of humpback 
whales by both Level A and Level B harassment has been increased 
accordingly in this notification of issuance.
    Regarding the application of the density data for the 17 species 
authorized for take, for some species only offshore data were 
available, for some only nearshore data, and for others data existed 
for both areas in which case we used the higher of the two values. 
Offshore densities were used to estimate take for eight species, 
nearshore data was used for five species and local observational data 
was used for four species. Data from these offshore sources results in 
averaging across large portions of the region. NSF notes that these 
data are from areas where cetaceans may occur in significantly greater 
densities than the Palmer Pier Project Area due to expected increased 
faunal density along the sea ice edge and shelf-frontal features in the 
southern oceans. These oceanographic features are not present within 
the Project Area, so lower densities of cetaceans are expected within 
close proximity to Palmer Station. Therefore, the offshore densities 
may represent an overestimate of anticipated densities within the 
Palmer Station Project Area.
    NSF estimated Level A harassment takes by multiplying the Level A 
harassment areas by the species density (nearshore or offshore as 
described above) which was then multiplied by the expected number of 
pile driving days for each activity type. The exposures for each 
activity were added to arrive at calculated Level A harassment take 
number as shown in Table 14. In cases where both nearshore and offshore 
densities were available, the higher of the two densities is used to 
estimate take. A similar approach was employed to derive estimated take 
by Level B harassment. The Level B harassment zones are determined by 
taking the total area of the Level B harassment zones (54.99 km\2\; 
20.78 km\2\; 5.27 km\2\; 0.07 km\2\) and subtracting the Level A 
harassment areas as defined by activity type and hearing group.
    The Level B harassment zone area was multiplied by the highest 
density for a species (nearshore or offshore as described above) which 
was multiplied by the expected number of pile driving days for each 
activity type. The exposures for each activity were summed to arrive at 
the calculated Level B harassment take numbers as shown in Table 14. 
Additional detailed information may be found in Appendix B of the 
application.

[[Page 61153]]



               Table 14--Calculated Level A and Level B Harassment Exposures Based on Density Data
----------------------------------------------------------------------------------------------------------------
                                                                   Level A harassment       Level B harassment
                            Species                                 total exposures          total exposures
----------------------------------------------------------------------------------------------------------------
Antarctic Minke Whale (LF)....................................                    15.23                   312.25
Arnoux's Beaked Whale (MF)....................................                   0.0001                     0.14
Blue Whale (LF)...............................................                   0.0081                     0.17
Fin Whale (LF)................................................                    13.74                   281.70
Hourglass Dolphin (HF)........................................                     0.32                     4.94
Humpback Whale (LF)...........................................                    14.72                   302.18
Killer Whale (MF).............................................                     0.04                   111.70
Long-finned Pilot Whale (MF)..................................                     0.01                    28.19
Southern Bottlenose Whale (MF)................................                    0.009                    23.55
Sei Whale (LF)................................................                     0.04                     0.84
Southern Right Whale (LF).....................................                     0.07                     1.34
Sperm Whale (MF)..............................................                     0.02                    16.73
Antarctic Fur Seal (OW).......................................                     0.15                   356.50
Crabeater Seal (PW)...........................................                   119.07                  6128.78
Southern Elephant Seal (PW)...................................                     0.02                     1.04
Leopard Seal (PW).............................................                     0.02                     1.04
Weddell Seal (PW).............................................                     3.65                   187.97
----------------------------------------------------------------------------------------------------------------

    In addition to considering density data presented in the 
literature, recent marine mammal observation data taken by bird 
researchers from Hero Inlet and nearby areas was considered. Palmer 
Station's research support staff conducted wildlife observations over 
the course of 15 months, on an average of 23 days a month. Observations 
were made for six minutes, three times per day, at 8 a.m., 1 p.m. and 5 
p.m. local time. The observer stood on the current pier to collect the 
observations. When weather conditions would not permit observations 
from the pier, observations were conducted from BioLab Building's 
second story located close behind the pier. The notification of 
proposed IHA contained an error that was included in NSF's IHA 
application. Table 19 in the notification of proposed IHA described how 
many pinnipeds had been observed at Palmer Station between the periods 
of January 21-March 28, 2019 and October 12, 2019-March 31, 2020. The 
column with the header October 12, 2019 through March 31, 2020 actually 
included data that was collected from March 30 to October 10, 2019. 
This time period was not included in Table 19 in the notification of 
proposed IHA. NMFS requested that NSF submit the corrected data for 
each of the three survey periods. The corrected table is included below 
as Table 15.
    Table 15 shows a comparison between observational data from the 
Project Area (NSF, personal communication) and the calculated takes by 
Level A harassment based on density data.

  Table 15--Comparison of Observation Data From Hero Inlet, Gamage Point and Bonaparte Point 2019-2020 to Total
                     Level A Harassment Exposure Estimates Calculated Based on Density Data
----------------------------------------------------------------------------------------------------------------
                                         January 21-March 28,     March 30-October 10,    October 12, 2019-March
               Species                    2019 observations        2019 observations        2020 observations
----------------------------------------------------------------------------------------------------------------
Humpback Whale (LF)..................                        0                        0                        2
Antarctic Fur Seal (OW)..............                       73                       70                      241
Crabeater Seal (PW)..................                       20                       24                       24
Southern Elephant Seal (PW)..........                        1                        0                      278
Leopard Seal (PW)....................                        3                        2                        2
Weddell Seal (PW)....................                        8                        6                       39
----------------------------------------------------------------------------------------------------------------

    As noted above, in relation to the observational data, NMFS has re-
analyzed estimated take of pinniped species in consideration of NSF's 
modification of the project dates (the project schedule now runs from 
February, 2020 to July, 2020 instead of October/November, 2002 to April 
2020) and the error in the pinniped observation data considered in the 
proposed IHA.
    In consideration of all of the raw data across 20 months, given the 
short daily observation periods and the large variation in numbers 
(even within the same month of a different year), we elected to use the 
highest number of animals of a given pinniped species observed on a 
single day during any month of the year, and then to multiply this 
value by the number of planned in-water work days (89). Further, 
although pinniped density would typically be expected to be focused 
closer to shore, given potential limitations of NSF's observation 
methods, we elected to precautionarily increase these estimated take 
numbers by 50 percent. We compared the takes based on observational 
data to the take numbers derived from published density values (Table 
14) and then authorized the larger of these two values. Density-derived 
takes were only greater for crabeater seals, so that is what we used in 
the final IHA and remains unchanged from the proposed IHA.
    Regarding the estimation of take by Level A harassment, for species 
in which the observational data is used rather than density, we 
consider what proportion of the total take would appropriately, or 
conservatively, be expected be in the form of Level A harassment. The 
area ensonified above the Level A take threshold is very small compared 
to the area ensonified above the Level B harassment zone (Table 13)--
specifically, less than 3% for the largest source and most sensitive 
taxa (phocids) and far smaller for other groups. Further, the 
implementation of shutdown zones is expected to avoid

[[Page 61154]]

some of the higher level or longer duration exposures that might 
potentially result in PTS. However, given that pinnipeds would be 
likely to spend a larger portion of their time in closer proximity to 
land (and potentially the pile driving source), we deemed it 
appropriate to conservatively estimate that 10 percent of the total 
calculated takes could potentially be by Level A harassment with the 
rest taken by Level B harassment.
    Table 16 shows the maximum number of animals observed on a single 
day during any month as well as authorized takes by Level A harassment, 
Level B harassment and combined takes for each pinniped species. Total 
combined Level A harassment and Level B harassment takes have increased 
from 1 to 936 for southern elephant seals; from 437 to 1,335 for 
Antarctic fur seals; from 198 to 267 Weddell seals; and from 10 to 134 
leopard seals. The density-based authorized take of crabeater seals 
remains unchanged at 6,249 from the notification of proposed IHA.

           Table 16--Final Authorized Takes Based on Observational or Density Data (Whichever Highest)
----------------------------------------------------------------------------------------------------------------
                                         Max # observed                                  Total  (Level A + Level
                Species                      per day         Level A         Level B                B)
----------------------------------------------------------------------------------------------------------------
Southern elephant seal.................               7              94             841                      935
Antarctic fur seal.....................              10             134           1,201                    1,335
Weddell seal...........................               2              27             240                      267
Crabeater seal *.......................               4             120           6,129                    6,249
Leopard seal...........................               1              14             120                      134
----------------------------------------------------------------------------------------------------------------
* Based on Density Data.

    Additional marine mammal observation data collected over a 5-year 
period at Palmer Station from January 4, 2015 through March 18, 2020 
was also considered (Friedlaender, Personal Communication). The data 
was collected using small boats, unmanned aerial systems (UASs) and 
land-based surveys. The assessment of this data is described as part of 
the responses to Comment 1 and Comment 2.
    Table 17 compares the number of calculated and authorized Level A 
and B harassment takes for each species. Level B harassment takes for 
Arnoux's beaked whale, blue whale, hourglass dolphin, sei whale, and 
Southern right whale have been adjusted based on group size such that a 
higher level of Level B harassment take has been authorized than was 
projected solely based on densities. Arnoux's beaked whales often occur 
in groups of 6-10 and occasionally up to 50 or more (Balcomb 1989). As 
a precautionary measure NSF requested and NMFS has authorized 12 takes 
of this species by Level B harassment. Classified as HF cetaceans, 
these beaked whales have a relatively large Level A harassment zone 
that extends to as much as 4,149 m. However, calculated take by Level A 
harassment is fractional and furthermore, this is a deep diving and 
deep foraging species and it would be unlikely that animals would 
congregate in a Level A harassment zone long enough to accrue enough 
energy to experience PTS. Therefore, no take by Level A harassment was 
requested, nor has been authorized by NMFS. Blue whales are unlikely to 
be found in the Project Area. However, NSF requested and NMFS has 
conservatively authorized two Level B harassment takes based on one 
average group size (NMFS, 2020). Hourglass dolphins group size is 
generally 2-6 individuals with groups of up to 25 observed (Santora 
2012). Classified as HF cetaceans, these dolphins have a relatively 
large Level A harassment zone that extends to 4,149 m. However, local 
observational data sets have not recorded a single animal and the 
species tends to be found in waters close to the Antarctic Convergence. 
Given this information NMFS has authorized 25 takes by Level B 
harassment which is a reduction from 60 takes requested by NSF. Level A 
harassment takes are not expected or authorized since the dolphin 
species is highly mobile and is unlikely to remain in the zone long 
enough to experience PTS. Sei whales have an average group size of 6 
(NMFS 2020) and generally inhabit continental shelf and slope waters 
far from coastlines. They are unlikely to occur, but as a precautionary 
measure, NSF had requested and NMFS has authorized 6 takes by Level B 
harassment. Takes by Level A harassment are not expected or authorized. 
Southern right whales live in groups of up to 20 individuals, but are 
more commonly found in groups of two or three, unless at feeding 
grounds. Observational surveys near Palmer Station did not record the 
presence of these whales. Therefore, NSF requested and NMFS has 
subsequently authorized 20 takes of Southern right whale by Level B 
harassment. No take by Level A harassment is anticipated or authorized.

          Table 17--Authorized Takes by Level A and Level B Harassment and as a Percentage of Abundance
----------------------------------------------------------------------------------------------------------------
                                          Authorized level A       Authorized level B     Total takes as percent
               Species                     harassment take          harassment take            of abundance
----------------------------------------------------------------------------------------------------------------
Antarctic Minke Whale (LF)...........                       15                      312                     4.42
Arnoux's Beaked Whale (MF) \a\.......                        0                       12                  Unknown
Blue Whale (LF) \a\..................                        0                        2                     0.12
Fin Whale (LF).......................                       14                      282                    19.84
Hourglass Dolphin (HF) \a\...........                        0                       25                     0.02
Humpback Whale (LF)..................                       15                      302                     2.54
Killer Whale (MF)....................                        0                      112                     0.45
Long-finned Pilot Whale (MF).........                        0                       28                     0.01
Southern Bottlenose Whale (MF).......                        0                       24                     0.04
Sei Whale (LF) \a\...................                        0                        6                     0.96
Southern Right Whale (LF) \a\........                        0                       20                     1.13
Sperm Whale (MF).....................                        0                       17                     0.14

[[Page 61155]]

 
Antarctic Fur Seal (OW) \b\..........                      134                    1,201                     0.05
Crabeater Seal (PW)..................                      120                    6,129                     0.12
Southern Elephant Seal (PW) \b\......                       94                      841                     0.23
Leopard Seal (PW) \b\................                       14                      120                     0.06
Weddell Seal (PW) \b\................                       27                      240                     0.05
----------------------------------------------------------------------------------------------------------------
\a\ Level B harassment takes increased to account for group size assuming one group is encountered during the
  project
\b\ Increased from calculated exposures due to local observational data.

    Table 17 also shows authorized takes by harassment for all species 
as a percentage of stock abundance.

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 following mitigation measures are required in the IHA:
     NSF must avoid direct physical interaction with marine 
mammals during construction activities. If a marine mammal comes within 
10 m of such activity, operations must cease and vessels must reduce 
speed to the minimum level required to maintain steerage and safe 
working conditions;
     Training must occur between construction supervisors and 
crews and the PSO team and relevant NSF staff prior to the start of all 
pile driving and construction activities, and when new personnel join 
the work, in order to explain responsibilities, communication 
procedures, marine mammal monitoring protocol, and operational 
procedures are clearly understood;
     Pile driving activities must be halted upon observation of 
either a species for which incidental take is not authorized or a 
species for which incidental take has been authorized but the 
authorized number of takes has been met, entering or within the Level A 
or Level B harassment zones as shown in Table 18 and Table 19;
     NSF will establish and implement a shutdown zone of 50 m 
for fur seals under all pile driving scenarios. The purpose of a 
shutdown zone is generally to define an area within which shutdown of 
the activity would occur upon sighting of a marine mammal (or in 
anticipation of an animal entering the defined area). Shutdown zones 
typically vary based on the activity type and marine mammal hearing 
group. Shutdown zones for cetaceans and other pinnipeds are based on 
Level A harassment isopleths shown in Table 12. Based on observation 
data, fur seals are known to swim up Hero Inlet (approximately 135 m 
wide) to haul out. The required 50-m shutdown zone for fur seals can 
safely be observed, will prevent injury to seals while still allowing 
seals to move up the inlet where they may haul out on land, and will 
allow construction to continue safely and efficiently;
     Shutdown zones have been established for all hearing 
groups under all driving scenarios as shown in Tables 18 and 19. If a 
marine mammal is observed entering or within the shutdown zones 
indicated in Tables 18 and 19, pile driving activity must be delayed or 
halted;
     Monitoring must take place from 30 minutes prior to 
initiation of pile driving activity through 30 minutes post-completion 
of pile driving activity. Pre-start clearance monitoring must be 
conducted during periods of visibility sufficient for the lead PSO to 
determine the shutdown zones shown in Table 18 and Table 19 are clear 
of marine mammals. Pile driving may commence following 30 minutes of 
observation when the determination is made;
     If the shutdown zones shown in Table 18 and Table 19 are 
not visible due to poor environmental conditions (e.g., excessive wind 
or fog, high Beaufort state), pile installation would cease until the 
entirety of the harassment shutdown zones is observable;
     If pile driving is delayed or halted due to the presence 
of a marine mammal, the activity may not commence or resume until 
either the animal has voluntarily exited and been visually confirmed 
beyond the shutdown zone or 15 minutes have passed without re-detection 
of the animal;
     If impact driving should be needed (i.e., for proofing) 
NSF 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 30-second waiting period, then two 
subsequent reduced-energy strike sets. A soft start must be implemented 
at the start of each day that begins with impact pile driving and at 
any time impact driving would occur after cessation of

[[Page 61156]]

impact pile driving for a period of 30 minutes or longer;
     In-water construction would occur during daylight over a 
12-hour workday to minimize the potential for PTS for species that may 
occur within the Level A harassment zones; and
     When transiting to the site, marine mammal watches must be 
conducted by crew or those navigating the vessel. When in the Project 
Area, if a whale is sighted in the path of a support vessel or within 
92 m (300 ft) from the vessel, NSF must reduce speed and must not 
engage the engines until the animals are clear of the area. If a whale 
is sighted farther than 92 m (300 ft) from the vessel, NSF must 
maintain a distance of 92 m (300 ft) or greater between the whale and 
the vessel and reduce speed to 10 knots or less. Vessels must not be 
operated in such a way as to separate members of a group of whales from 
other members of the group. A group is defined as being three or more 
whales observed within a 500 m area and displaying behaviors of 
directed or coordinated activity (e.g., group feeding).

                           Table 18--Shutdown and Harassment Zones (Meters) for Non-Simultaneous Pile Installation Activities
                                  [Level A harassment zone indicated in parentheses where different from shutdown zone]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                             Cetaceans                               Pinnipeds                Level B
               Pile size, type, and method               --------------------------------------------------------------------------------   harassment
                                                                LF              MF              HF              PW              OW             zone
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dock, 36-in Dia. Pile Installation, 20' Socket Depth--1    1,000 (1,981)              70   1,000 (2,253)   1,000 (1,012)         50 (74)          11,659
 pile/day (DTH).........................................
Dock Abutment, 36-in Dia. Pile Installation, 30' Socket    1,000 (2,475)              90   1,000 (2,951)   1,000 (1,326)         50 (97)
 Depth--1 pile/day (DTH)................................
RHIB Fender Piles, 24-in Dia. Pile Installation, 20'                 410              15             485             220              50
 Socket--1 pile/day.....................................
24-in Dia. Template Piles, 10' Socket Depth--2 piles/day
24-in Dia Wave Attenuator Piles, 20' Socket Depth--1
 pile/day...............................................
Retaining Wall HP Pile inserted in Drilled 24-in Dia
 Sockets, 20' Socket Depth--1 pile/day..................
Removal of 24-in Dia. Template Piles--16 piles..........              55              10              75              35              50          10,000
Removal of Sheet Piles..................................              25              10              35              15              50           4,642
Rock Chipping/Floor Preparation.........................             405              50             720             205              50             123
Anode Installation......................................              10              10              10              10              50             200
--------------------------------------------------------------------------------------------------------------------------------------------------------


                     Table 19--Shutdown and Harassment Zones (Meters) for Simultaneous Pile Installation Activities (Shutdown Zone)
                                  [Level A harassment zone indicated in parentheses where different from shutdown zone]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                             Cetaceans                               Pinnipeds                Level B
                 Daily scenario activity                 --------------------------------------------------------------------------------   harassment
                                                                LF              MF              HF              PW              OW             zone
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dock, 36-in Dia. Pile Installation, 20' Socket Depth--2    1,000 (3,002)             110   1,000 (3,576)   1,000 (1,607)        50 (117)          18,478
 pile/day...............................................
Dock Abutment, 36-in Dia. Pile Installation, 30' Socket    1,000 (3,484)             125   1,000 (4,149)   1,000 (1,864)        50 (136)
 Depth and 36-in Dia. Pile 20' Socket Depth.............
RHIB Fender Piles, 24-in Dia. Pile Installation, 20'                 650              25             770             350              50
 Socket--2 pile/day.....................................
24-in Dia. Template Piles, 10' Socket Depth--4 piles/day
24-in Dia Wave Attenuator Piles, 20' Socket Depth--2
 pile/day...............................................
Retaining Wall--HP Pile inserted in Drilled 24-in Dia
 Sockets, 20' Socket Depth--2 piles/day.................
Dock, 36-in Dia. Pile Installation, 20' Socket Depth--1    1,000 (2,011)              75   1,000 (2,395)   1,000 (1,076)         50 (78)
 pile/day and Wave Attenuator, 24-in Dia. Pile
 Installation, 20' Socket--1 pile/day...................
Dock, 36-in Dia. Pile Installation, 20' Socket Depth--1    1,000 (2,885)             105   1,000 (3,436)   1,000 (1,644)        50 (133)
 pile/day and Wave Attenuator, 24-in Dia. Pile
 Installation, 20' Socket--1 pile/day...................
36-in Dock 20' socket x 2 Dock Abutment.................              45              10              65              30              50          34,146
RHIB Fender Piles 24-in x 2.............................              20              10              30              15              50          15,849
24-in template 10' socket x 4...........................
24-in wave attenuator piles--10'socket x 2..............              35              10              50              20              50
24-in wave attenuator piles--20'socket x 2..............
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, we have determined that the 
required mitigation measures provide the means of 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 
planned Project 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

[[Page 61157]]

should contribute to improved understanding of one or more of the 
following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stock;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.

Visual Monitoring

    One NMFS-approved, formally trained PSO with prior experience 
performing the duties of a PSO during construction activities would 
serve as team leader, supported by three PSOs trained on site or 
through available online training programs compliant with NMFS 
standards. PSOs must be independent (i.e., not construction personnel) 
and have no other assigned tasks during monitoring periods. Prior to 
initiation of construction, PSOs would complete a training/refresher 
session on marine mammal monitoring, to be conducted shortly before the 
anticipated start of the open water season construction activities.
    Primary objectives of the training session include:
     Review of the mitigation, monitoring, and reporting 
requirements provided in the application and IHA, including any 
modifications specified by NMFS in the authorization;
     Review of marine mammal sighting, identification, and 
distance estimation methods;
     Review of operation of specialized equipment (bigeye 
binoculars, GPS); and
     Review of, and classroom practice with, data recording and 
data entry systems, including procedures for recording data on marine 
mammal sightings, monitoring operations, environmental conditions, and 
entry error control.
    PSOs must have the following additional qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    Two PSOs must be on duty during all in-water construction 
activities and must record all observations of marine mammals 
regardless of distance from the pile being driven or covered activity. 
PSOs shall document any behavioral reactions in concert with distance 
from piles being driven or removed. PSOs are limited to monitoring no 
more than 4 hours per shift with sufficient breaks and no more than 12 
hours per day to minimize fatigue.
    The placement of PSOs during all pile driving activities will 
ensure that the entire shutdown zones are visible during pile 
installation. Should environmental conditions deteriorate such that 
marine mammals within the entire shutdown zone will not be visible 
(e.g., fog, heavy rain), pile driving activities must be delayed until 
the PSO is confident marine mammals within the shutdown zone could be 
detected. The primary monitoring location currently utilized by NSF 
will be on the roof platform of the Garage Warehouse Recreation (GWR) 
building (approximately 20 m above sea level) to provide visual 
coverage of the shutdown zones, as well as the Level A harassment zones 
to the extent practicable. NMFS agrees that the GWR building is an 
appropriate monitoring location. The primary PSO can monitor the 
Project Area generally south-southeast while the second PSO can monitor 
the area generally west-southwest that may be ensonified. With reticle 
binoculars the distance potentially visible by a 1.8-m tall PSO from 
this point would be about 4,360 m. Mounted big eye binoculars would be 
provided to PSOs for better coverage of the shutdown zones and the 
Level A harassment zones. NSF believes this location is adequate to 
monitor the 1,000-m shutdown zone and some of the Level A harassment 
zone to the extent practicable beyond 1,000 m.

Reporting

    A draft marine mammal monitoring report will be submitted to NMFS 
within 90 days after the completion of pile driving activities, or 60 
days prior to a requested date of issuance of any future IHAs for 
projects at the same location, whichever comes first. The report will 
include an overall description of work completed, a narrative regarding 
marine mammal sightings, and associated PSO data sheets. Specifically, 
the report must include:
     Dates and times (begin and end) of all marine mammal 
monitoring;
     Construction activities occurring during each daily 
observation period, including the number and type of piles driven or 
removed and by what method (i.e., impact or cutting) and the total 
equipment duration for cutting for each pile or total number of strikes 
for each pile (impact driving);
     PSO locations during marine mammal monitoring;
     Environmental conditions during monitoring periods (at 
beginning and end of PSO shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance;
     Upon observation of a marine mammal, the following 
information: Name of PSO who sighted the animal(s) and PSO location and 
activity at time of sighting; Time of sighting; Identification of the 
animal(s) (e.g., genus/species, lowest possible taxonomic level, or 
unidentified), PSO confidence in identification, and the composition of 
the group if there is a mix of species; Distance and bearing of each 
marine mammal observed relative to the pile being driven for each 
sighting (if pile driving was occurring at time of sighting); Estimated 
number of animals (min/max/best estimate); Estimated

[[Page 61158]]

number of animals by cohort (adults, juveniles, neonates, group 
composition, etc.); Animal's closest point of approach and estimated 
time spent within the harassment zone; Description of any marine mammal 
behavioral observations (e.g., observed behaviors such as feeding or 
traveling), including an assessment of behavioral responses thought to 
have resulted from the activity (e.g., no response or changes in 
behavioral state such as ceasing feeding, changing direction, flushing, 
or breaching);
     Number of marine mammals detected within each of the Level 
A harassment and Level B harassment zones, by species; and
     Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensued, and resulting changes in behavior of the 
animal(s), if any.
    If no comments are received from NMFS within 30 days, the draft 
final report will constitute the final report. If comments are 
received, a final report addressing NMFS comments must be submitted 
within 30 days after receipt of comments.

Reporting Injured or Dead Marine Mammals

    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the IHA-holder must 
immediately cease the specified activities and report the incident to 
the Office of Protected Resources ([email protected]), 
NMFS as soon as feasible. If the death or injury was clearly caused by 
the specified activity, NSF must immediately cease the specified 
activities until NMFS is able to review the circumstances of the 
incident and determine what, if any, additional measures are 
appropriate to ensure compliance with the terms of the IHA. The IHA-
holder must not resume their activities until notified by NMFS. The 
report must include the following information:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and
     General circumstances under which the animal was 
discovered.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    DTH pile installation, vibratory pile removal, limited impact pile 
driving for proofing, rock chipping and use of a hydrogrinder have the 
potential to disturb or displace marine mammals. Specifically, the 
project activities may result in take, in the form of Level A and Level 
B harassment from underwater sounds generated from pile driving 
activities, if individuals are present in the ensonified zone when 
these activities are underway.
    The takes from Level A and Level B harassment would be due to 
potential PTS, TTS and behavioral disturbance. Even absent mitigation, 
no mortality or serious injury is anticipated given the nature of the 
activity and construction method. The potential for harassment would be 
further minimized through the implementation of the planned mitigation 
measures (see Mitigation section).
    Effects on individual animals that are taken by Level B harassment, 
on the basis of reports in the literature as well as monitoring from 
other similar activities, will likely be limited to reactions such as 
increased swimming speeds, increased surfacing time, or decreased 
foraging (if such activity were occurring) (e.g., Thorson and Reyff 
2006; Lerma 2014; ABR 2016). Most likely, individuals will simply move 
away from the sound source and be temporarily displaced from the areas 
of pile installation, although even this reaction has been observed 
primarily only in association with impact pile driving. If sound 
produced by project activities is sufficiently disturbing, animals are 
likely to simply avoid the area while the activity is occurring. While 
DTH pile installation associated with the planned project may produce 
sound at distances of many kilometers from the project site, we expect 
that animals annoyed by project sound would simply avoid the area and 
use more-preferred habitats. Furthermore, during any impact driving, 
implementation of soft start procedures will be required and monitoring 
of established shutdown zones will be required for all pile 
installation and removal activities, significantly reducing the 
possibility of injury. Use of impact driving will be limited to 
proofing of piles after they have been set in place. Given sufficient 
notice through use of soft start (for impact driving), marine mammals 
are expected to move away from an irritating sound source prior to it 
becoming potentially injurious. This sort of low-level localized 
displacement, in the absence of any specific known biologically 
important areas around Palmer Station, would not be expected to impact 
the reproduction or survival of any individuals.
    In addition to the expected effects resulting from authorized Level 
B harassment, we anticipate that Antarctic minke whales, fin whales, 
and humpback whales may sustain some limited Level A harassment in the 
form of auditory injury, given the large PTS zones for LF cetaceans. We 
are also authorizing take by Level A harassment of Antarctic fur seals, 
crabeater seals, leopard seals, Weddell seals, and Southern elephant 
seals since the Level A harassment zones are large relative to the 
ability to detect these species and they are generally considered more 
likely than cetaceans to potentially remain within the nearshore Level 
A harassment zone for longer amounts of time. The Level A harassment 
zones identified in Table 11 and Table 12 are based upon an animal 
exposed to impact pile driving multiple piles per day. Considering the 
short duration to

[[Page 61159]]

impact drive or DTH each pile and breaks between pile installations (to 
reset equipment and move pile into place), this means an animal would 
have to remain within the area estimated to be ensonified above the 
Level A harassment threshold for extended periods. This is highly 
unlikely given typical movement of both cetaceans and pinnipeds 
throughout the area. However, animals that experience PTS would likely 
be subjected to slight PTS, i.e. minor degradation of hearing 
capabilities within regions of hearing that align most completely with 
the frequency range of the energy produced by pile driving, i.e., the 
low-frequency region below 2 kHz, not severe hearing impairment or 
impairment in the regions of greatest hearing sensitivity. If hearing 
impairment occurs, it is most likely that the affected animal would 
lose a few decibels in its hearing sensitivity, which in most cases is 
not likely to meaningfully affect its ability to forage and communicate 
with conspecifics.
    The project is also not expected to have significant adverse 
effects on affected marine mammals' habitats. The project activities 
would not modify existing marine mammal habitat for a significant 
amount of time. The activities may increase sedimentation and cause 
some fish to leave the area of disturbance, thus temporarily impacting 
marine mammals' foraging opportunities in a limited portion of the 
foraging range; but, because of the relatively small area of the 
habitat that may be affected, the impacts to marine mammal habitat are 
not expected to cause significant or long-term negative consequences 
for marine mammals.
    The nature of NSF's planned construction activities precludes the 
likelihood of serious injury or mortality, even absent mitigation. For 
all species and stocks, take would occur within a limited area (Hero 
Inlet and nearby waters) that constitutes a small portion of the ranges 
for authorized species. Level A and Level B harassment will be reduced 
to the level of least practicable adverse impact through use of 
mitigation measures described herein. Further, the amount of take 
authorized is extremely small when compared to stock abundance of 
authorized species.
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect the species or stock through 
effects on annual rates of recruitment or survival:
     No mortality or serious injury is anticipated or 
authorized;
     The relatively small number of Level A harassment 
exposures are anticipated to result only in slight PTS within the lower 
frequencies associated with pile driving;
     The anticipated incidents of Level B harassment would 
consist of, at worst, temporary modifications in behavior that would 
not result in fitness impacts to individuals;
     No adverse effects on affected marine mammals' habitat are 
anticipated;
     No areas that are known to be specifically important for 
marine mammal feeding or reproduction have been identified within the 
Project Area;
     For all species, Hero Inlet and nearby waters represent 
very small and peripheral part of their ranges; and
     The required mitigation measures (i.e., shutdown zones) 
are expected to be effective in reducing the effects of the specified 
activity.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the required monitoring and 
mitigation measures, 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.
    The amount of take authorized by NMFS is below one third of the 
estimated stock abundances for all 17 species. For fin whales, the 
authorized take of individuals is less than 20 percent of the abundance 
of the affected species or stock, and less than 5 percent for the 
remainder of the species, as shown in Table 17. This is likely a 
conservative estimate because it assumes all takes are of different 
individual animals, which is likely not the case. Some individuals may 
return multiple times in a day, but PSOs would count them as separate 
takes if they cannot be individually identified. 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

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
determined that the total taking of affected species or stocks would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

Endangered Species Act

    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 ESA Interagency 
Cooperation Division.
    There are five marine mammal species (blue whale, fin whale, sei 
whale, Southern right whale, and sperm whale) with confirmed occurrence 
in the project area that are listed as endangered under the ESA. The 
ESA Interagency Cooperation Division issued a Biological Opinion on 
October 25, 2021, under section 7 of the ESA, on the issuance of an IHA 
to NSF 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 endangered blue 
whale, fin whale, sei whale, Southern right whale, or sperm whale.

National Environmental Policy Act

    NMFS has adopted NSF's Final Initial Environmental Evaluation 
(IEE), which is generally the equivalent of an environmental assessment 
(EA) under the Antarctic Conservation Act (16 U.S.C. 2401 et seq.). 
NMFS determined

[[Page 61160]]

that the document includes adequate information analyzing the effects 
on the human environment of issuing the IHA. This IEE 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 IEE. A Finding of No Significant Impact (FONSI) was 
signed on October 27, 2021. A copy of the IEE and FONSI is available 
upon online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.

Authorization

    NMFS has issued an IHA to NSF for the potential harassment of small 
numbers of 17 marine mammal species incidental to pile driving 
activities associated with construction of the Palmer Station Pier 
Replacement project at Anvers Island, Antarctica, provided the 
previously mentioned mitigation, monitoring and reporting requirements 
are followed.

    Dated: November 2, 2021.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2021-24274 Filed 11-4-21; 8:45 am]
BILLING CODE 3510-22-P