Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Construction Activities for the Statter Harbor Improvement Project, 55920-55939 [2019-22730]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 84, Number 202 (Friday, October 18, 2019)]
[Notices]
[Pages 55920-55939]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-22730]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XR049


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Construction Activities for the 
Statter Harbor Improvement Project

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

ACTION: Notice; proposed incidental harassment authorization; request 
for comments on proposed authorization and possible renewal.

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SUMMARY: NMFS has received a request from the City of Juneau for 
authorization to take marine mammals incidental to vibratory and impact 
pile driving, vibratory pile removal, and down the hole drilling in 
Auke Bay, Alaska. Pursuant to the Marine Mammal Protection Act (MMPA), 
NMFS is requesting comments on its proposal to issue an incidental 
harassment authorization (IHA) to incidentally take marine mammals 
during the specified activities. NMFS is also requesting comments on a 
possible one-year renewal that could be issued under certain 
circumstances and if all requirements are met, as described in Request 
for Public Comments at the end of this notice. NMFS will consider 
public comments prior to making any final decision on the issuance of 
the requested MMPA authorizations and agency responses will be 
summarized in the final notice of our decision.

DATES: Comments and information must be received no later than November 
18, 2019.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. Physical comments should be sent to 
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments 
should be sent to [email protected].
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted online at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act without change. All personal identifying 
information (e.g., name, address) voluntarily submitted by the 
commenter may be publicly accessible. Do not submit confidential 
business information or otherwise sensitive or protected information.

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

SUPPLEMENTARY INFORMATION: 

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are issued or, if the taking is limited to harassment, a notice of a 
proposed incidental take authorization may be provided to the public 
for review.

[[Page 55921]]

    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of such species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of such takings are set forth.
    The definitions of all applicable MMPA statutory terms cited above 
are included in the relevant sections below.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) with respect to potential impacts 
on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (incidental harassment authorizations with 
no anticipated serious injury or mortality) of the Companion Manual for 
NOAA Administrative Order 216-6A, which do not individually or 
cumulatively have the potential for significant impacts on the quality 
of the human environment and for which we have not identified any 
extraordinary circumstances that would preclude this categorical 
exclusion. Accordingly, NMFS has preliminarily determined that the 
issuance of the proposed IHA qualifies to be categorically excluded 
from further NEPA review.
    We will review all comments submitted in response to this notice 
prior to concluding our NEPA process or making a final decision on the 
IHA request.

Summary of Request

    On April 15, 2019, NMFS received a request from the City of Juneau 
for an IHA to take marine mammals incidental to construction activities 
at Statter Harbor in Auke Bay, Alaska. The application was deemed 
adequate and complete on September 26, 2019. The City of Juneau's 
request is for take of a small number of eight species of marine 
mammals, by Level B harassment and Level A harassment. Neither the City 
of Juneau nor NMFS expects serious injury or mortality to result from 
this activity and, therefore, an IHA is appropriate.
    NMFS previously issued an IHA to the City of Juneau for related 
work (84 FR 11066; March 25, 2019), which covers the first phase of 
activities (dredging, blasting, pile removal) and is effective from 
October 1, 2019 to September 30, 2020. The City of Juneau has not yet 
conducted any work under the previous IHA and therefore no monitoring 
results are available at the time of writing.
    This proposed IHA would cover one year of a larger project for 
which the City of Juneau obtained one prior IHA. The larger multi-year 
project involves several harbor improvement projects including 
dismantling and demolition of existing docks, construction of a 
mechanically stabilized earth wall, and installation of concrete 
floats.

Description of Proposed Activity

Overview

    The harbor improvements described in the application include 
installation of timber floats supported by 20 16-inch steel pipe piles, 
installation of a gangway, replacement of piles supporting a transient 
float, and removal of temporary fill that will be placed under the 
first IHA and construction of the permanent mechanically stabilized 
earth (MSE) wall.

Dates and Duration

    The proposed activities are expected to occur between October 1, 
2020 and May 1, 2021 but the IHA would be valid for one year to account 
for any delays in the construction timeline. In winter months, shorter 
8-hour to 10-hour workdays in available daylight are anticipated. To be 
conservative, 12-hour work days were assumed for the purposes of 
analysis in this notice.

Specific Geographic Region

    The proposed activities would occur at Statter Harbor in Auke Bay, 
Alaska which is in the southeast portion of the state. See Figure 3 in 
the application for detailed maps of the project area. Statter Harbor 
is located at the most northeasterly point of Auke Bay.

Detailed Description of Specific Activity

    New infrastructure to be installed includes 9,136 square feet 
(848.8 square meters) of timber floats supported by twenty (20) 16-inch 
(4.1-decimeter) diameter steel pipe piles, an 10-foot by 100-foot 
gangway (3-meters by 30.5-meters), removal of the temporary surcharge 
fill and construction of the permanent MSE wall.
    In addition to the new infrastructure, three existing piles will be 
repaired. A transient float was installed in Statter Harbor in 2018 as 
part of a different project and it is not operating as intended due to 
wave action and excessive movement of the float. Three temporary piles 
were installed without rock anchors as a temporary fix. During the 
proposed work, these piles will be removed with a crane or vibratory 
hammer and reinstalled with rock anchors to provide sufficient moorage 
capacity for the float.
    Pile driving/removal will be conducted from a floating barge, 
utilizing a drill to install rock sockets and a vibratory hammer to 
install piles. Use of impact hammers is not anticipated, and will only 
be used for piles that encounter soils too dense to penetrate with the 
vibratory equipment. The floats will be unloaded from a barge and 
placed in the water. Piles will be driven as each float section is 
installed to hold the floats in place. Due to the substrate in the 
harbor, it is anticipated all of the piles will require drilling for 
rock anchors, referred to in this notice as down the hole drilling. The 
drilling would likely occur midway through vibratory installation of a 
pile and would occur on the same day the pile is being driven. A 
summary of the number and type of piles proposed to be driven is 
included in Table 1 below.

                                                        Table 1--Pile Driving and Removal Summary
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                                                                                     Average
                                  Number                                            piles/day    Driving    Strike/pile       Estimated total  daily
            Activity               piles     Pile size/type          Method            \1\        days      or minutes/              duration
                                                                                     (Range)                   pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pile Removal...................         3  16-inch (4.1-       Vibratory.........            3         1              30  12 hours/500 strikes.
Pile Installation..............        23   decimeter) Steel   Vibratory.........    1.5 (1-3)      8-23             120
                                            Pipe.

[[Page 55922]]

 
                                                               Impact............      1 (0-2)                       250
                                                               Drilling..........    1.5 (1-3)                       240
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    The temporary surcharge fill, placed during the previous IHA, would 
be excavated to elevation of the wall toe, approximately +3 feet (0.9 
meters) MLLW or higher dependent on the location along the wall. The 
applicant will require the contractor to conduct all excavation work 
for temporary surcharge fill removal when the tide is below the work 
elevation, such that it will be completed in the dry. The wall would be 
constructed and then backfilled, reusing the temporary surcharge fill 
consisting of clean Class A shot rock originally used for the temporary 
blast pad in the previous IHA. Excavation and fill placement will be 
conducted such that work is done in the dry and not in the presence of 
marine mammals, thus excavation and fill placement are not discussed 
further in this notice.
    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

    Eight species of marine mammal have been documented in southeast 
Alaska waters in the vicinity of Statter Harbor. These species are: 
Harbor seal, harbor porpoise, Dall's porpoise, killer whale, humpback 
whale, minke whale, California sea lion, and Steller sea lion. Of these 
species, only three are known to occur in Statter Harbor regularly: 
Harbor seal, Steller sea lion, and humpback whale.
    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS's Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS's 
website (https://www.fisheries.noaa.gov/find-species).
    Table 2 lists all species with expected potential for occurrence in 
Statter Harbor and summarizes information related to the population or 
stock, including regulatory status under the MMPA and ESA and potential 
biological removal (PBR), where known. For taxonomy, we follow 
Committee on Taxonomy (2018). PBR is defined by the MMPA as the maximum 
number of animals, not including natural mortalities, that may be 
removed from a marine mammal stock while allowing that stock to reach 
or maintain its optimum sustainable population (as described in NMFS's 
SARs). While no mortality is anticipated or authorized here, PBR and 
annual serious injury and mortality from anthropogenic sources are 
included here as gross indicators of the status of the species and 
other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS's U.S. Alaska Region and Pacific Region SARs (Carretta et al., 
2019; Muto et al., 2019). All values presented in Table 2 are the most 
recent available at the time of publication and are available in the 
2018 SARs (Carretta et al., 2019; Muto et al., 2019).

                                             Table 2--Species With the Potential To Occur in Statter Harbor
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                                                                                        ESA/ MMPA  status;   Stock abundance  (CV,
             Common name                  Scientific name               Stock             strategic  (Y/N)     Nmin, most recent       PBR     Annual M/
                                                                                                \1\          abundance survey) \2\               SI \3\
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                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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Family Balaenopteridae (rorquals):
Humpback whale......................  Megaptera noveangliae..  Central North Pacific..  E, D,Y              10,103 (0.3, 7,891,            83         26
                                                                                                             2006).
Minke whale.........................  Balaenoptera             Alaska.................  -;N                 N/A...................        Und          0
                                       acutorostrata.
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                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
Killer whale........................  Orcinus orca...........  Northern Resident......  -;N                 261 (N/A, 261, 2011)..       1.96          0
Killer whale........................  Orcinus orca...........  Gulf of Alaska           -;N                 587 (N/A, 587, 2012)..       5.87          1
                                                                transient.
Killer whale........................  Orcinus orca...........  West Coast Transient...  -;N                 243 (N/A, 243, 2009)..        2.4          0
Family Phocoenidae (porpoises):
Harbor porpoise.....................  Phocoena phocoena......  Southeast Alaska.......  -;Y                 975 (0.14, 872, 2012).        8.7         34
Dall's porpoise.....................  Phocoenoides dalli.....  Alaska.................  -;N                 83,400 (0.097, N/A,           Und         38
                                                                                                             1991).
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                                                         Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
 sea lions):

[[Page 55923]]

 
California sea lion.................  Zalophus califonrianus.  U.S....................  -;N                 257,606 (N/A, 233,515,     14,011        197
                                                                                                             2014).
Steller sea lion....................  Eumetopias jubatus.....  Western DPS............  E/D; Y              54,267 (N/A; 54,267,          326        252
                                                                                                             2017).
Steller sea lion....................  Eumetopias jubatus.....  Eastern DPS............  T/D; Y              41,638 (N/A, 41,638,        2,498        108
                                                                                                             2015).
Family Phocidae (earless seals):
Harbor seal.........................  Phoca vitulina.........  Lynn Canal.............  -;N                 9,478 (N/A, 8,605,            155         50
                                                                                                             2011).
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\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range.

    All species that could potentially occur in the proposed survey 
areas are included in Table 2. As described below, all eight species 
(with eleven managed stocks) temporally and spatially co-occur with the 
activity to the degree that take is reasonably likely to occur, and we 
have proposed authorizing it.
    In addition, the sea otter (Enhydra lutris) may be found in 
southeast Alaska. However, sea otters are managed by the U.S. Fish and 
Wildlife Service and are not considered further in this document.

Humpback Whale

    Prior to 2016, humpback whales were listed under the ESA as an 
endangered species worldwide. Following a 2015 global status review 
(Bettridge et al., 2015), NMFS established 14 distinct population 
segments (DPS) with different listing statuses (81 FR 62259; September 
8, 2016) pursuant to the ESA. The DPSs that occur in U.S. waters do not 
necessarily equate to the existing stocks designated under the MMPA and 
shown in Table 2. Because MMPA stocks cannot be portioned, i.e., parts 
managed as ESA-listed while other parts managed as not ESA-listed, 
until such time as the MMPA stock delineations are reviewed in light of 
the DPS designations, NMFS considers the existing humpback whale stocks 
under the MMPA to be endangered and depleted for MMPA management 
purposes (e.g., selection of a recovery factor, stock status).
    Humpbacks that breed around the main Hawaiian Islands have been 
observed in summer feeding grounds throughout the North Pacific. The 
majority of the humpbacks found in Southeast Alaska and northern 
British Columbia have migrated from Hawaii for foraging opportunities 
and belong to the Hawaii Distinct Population Segment (DPS) (Bettridge 
et al., 2015). Wade et al. (2016) estimated that 93.9 percent of the 
humpbacks encountered in Southeast Alaska and Northern British Columbia 
are from the Hawaii DPS, with the remaining percentage of humpbacks 
coming from the Mexico DPS.
    While in their Alaskan feeding grounds, humpback whales prey on a 
variety of euphausiids and small schooling fishes including herring, 
smelt, capelin, sandlance, juvenile pollock, and salmon smolts 
(Kawamura 1980; Krieger and Wing 1986; Witteveen et al., 2008; Straley 
et al., 2017; Chenoweth et al., 2017). Herring targeted by Southeast 
Alaska whales in Lynn Canal during 2007-2009 winters were lipid-rich, 
with energy content ranging from 7.3-10.0 kJ/gram (Vollenweider et al., 
2011). The local distribution of humpbacks in Southeast Alaska appears 
to be correlated with the density and seasonal availability of prey, 
particularly herring and euphausiids (Moran et al., 2017). Important 
feeding areas include Glacier Bay and adjacent portions of Icy Strait, 
Stephens Passage/Frederick Sound, Seymour Canal, Lynn Canal, and Sitka 
Sound and these areas have been included in the designation of a 
Biologically Important Area for humpbacks in the Gulf of Alaska. During 
autumn and winter, the non-breeding season, humpbacks remaining in 
Southeast Alaska target areas where herring and eulachon are abundant, 
such as Seymour Canal, Berners Bay, Auke Bay, Lynn Canal, and Stephens 
Passage (Krieger and Wing 1986; Moran et al., 2017). Over 2,940 and 
2,019 humpback whale foraging-days were documented in Lynn Canal alone 
in 2007-2008 and 2008-2009 winter seasons, respectively (Moran et al., 
2017).
    Fidelity to feeding grounds by individual humpbacks is well 
documented; interchange between Alaskan feeding grounds is rare 
(Witteveen and Wynne 2017). Long-term research and photo-identification 
efforts have documented individual humpbacks that have returned to the 
same feeding grounds for as many 45 years (Straley 2017; Witteveen and 
Wynne 2017; Gabriele et al., 2017). Based on fluke pattern 
identification, Krieger, Baker and Wing identified 189 unique whales in 
the Juneau to Glacier Bay and Seymour Canal area (Krieger et al., 
1986). In recent years, 179 individual humpback whales were identified 
from the Juneau area, based upon fluke photographs taken between 2006 
and 2014 (Teerlink 2017). Humpback whales occur in the project area 
intermittently year-round. Auke Bay and Statter Harbor are thought to 
have certain habitat features that attract humpback whales in recent 
years. The aggregation of herring in inner Auke Bay provide a habitat 
where whales may make energetic decisions to exploit small volumes of 
fish and rest to conserve energy between foraging opportunities.
    Humpback whales utilize habitats in the project area 
intermittently. The breakwater and other dock structures appear to 
serve as fish-attracting devices, where forage fish (herring, capelin, 
sandlance, pollock, and juvenile salmon) aggregate and are targeted by 
diving humpback whales. Two humpback whales in recent years have also 
targeted a shallow trough off the east end of the Statter Harbor 
breakwater for deeper diving foraging excursions targeting herring and 
possibly juvenile pollock (Ridgway pers. observ.). Some individual 
whales enter

[[Page 55924]]

Auke Bay through the north Coghlan Island entrance and conduct a 
pattern of exploitation or ``browsing'' in the bay and inner harbor. In 
this area some whales lunge feed and gulp massive volumes of feed in 
seawater immediately adjacent to or rubbing against boats, docks and 
other structures in deep to shallow waters throughout the action area. 
These whales have been observed continuing a pattern search alongshore 
to Auke Creek and up Fritz Cove, where they have been seen lunge 
feeding in small coves and gullies in shallow water to aggregate 
schooling fish.
    Because humpback whale individuals of different DPS origin are 
indistinguishable from one another in Alaska (unless fluke patterns are 
linked to the individual in both feeding and breeding ground), the 
frequency of occurrence of animals by DPS is only estimated using the 
DPS ratio, based upon the assumption that the ratio is consistent 
throughout the Southeast Alaska region (Wade et al., 2016).

Minke Whale

    Minke whales are widely distributed throughout the northern 
hemisphere and are found in both the Pacific and Atlantic oceans. Minke 
whales in Alaska are considered migratory and during summer months are 
typically found in the Arctic and during winter months are found near 
the equator (NMFS 2019a).
    Little is known about minke whale breeding areas, although it is 
believed they calve in the winter months. Minke whales feed by side-
lunging through schools of prey and are opportunistic predators feeding 
on a variety of crustaceans, plankton, and small school fish (NMFS 
2019a).
    There is no quantifiable information on abundance or seasonality in 
Auke Bay or the surrounding area.

Killer Whale

    NMFS considers three stocks of killer whales to occur in southeast 
Alaskan waters, which may occur separately or concurrently within the 
project area. These stocks are the Eastern North Pacific/Alaska 
Resident stock (2,347 individuals), Eastern North Pacific/Northern 
Resident stock (261 individuals), the West Coast Transient stock (243 
individuals) (Muto et al., 2018). These stocks represent two of the 
three ecotypes of killer whales occurring within the North Pacific 
Ocean--resident (forages on fish) and transient (forages primarily on 
marine mammals). However, NMFS is evaluating new genetic information 
that will likely result in a revision of the above stock structure 
(Muto et al., 2018).
    The species has the most varied diet of all cetaceans; however, the 
transient populations typically hunt marine mammals while the resident 
populations feed on fish, particularly salmon and Atka mackerel 
(Barrett-Lennard et al., 2011; Parsons et al., 2013). Residents often 
travel in much larger and closer groups than transients and have been 
observed sharing fish they catch. Transient killer whales feed on other 
marine mammals including Steller sea lions, harbor seals, and various 
species of cetaceans. They are also more likely to rely on stealth, 
making less frequent and less conspicuous calls and skirting ``along 
shorelines and around headlands'' in order to hunt their prey in highly 
coordinated attacks (Barrett-Lennard et al., 2011).
    The best available data for Auke Bay comes from a compilation of 
public sightings recorded by Oceanus Alaska. This compilation is 
believed to be comprehensive as Juneau residents often report killer 
whale sightings. Killer whales are have been observed during all 
months, however less frequently in winter months. From 2010-2017 an 
average of 25 killer whale sightings were recorded in the project area 
per year (Ridgeway unpubl. data 2017). Data did not make distinctions 
between the stocks and thus the ratio between stocks is unknown. 
However, the AG resident pod is one pod known to frequent the Juneau 
area (Dahlheim et al., 2009; personal observation) and has 41 members 
recorded in the North Gulf Oceanic Society's Identification Guide (NGOS 
2019). This pod is seen in the area intermittently in groups of up to 
approximately 25 individuals (personal observation), consistent with 
the data for the area. Transient killer whales have been observed in 
nearby waterways as well and one group of 14 individuals were observed 
during surveys (Dahlheim et al., 2009).

Harbor Porpoise

    In Alaska, harbor porpoises are currently divided into three 
stocks, based primarily on geography: (1) The Southeast Alaska stock--
occurring from the northern border of British Columbia to Cape 
Suckling, Alaska, (2) the Gulf of Alaska stock--occurring from Cape 
Suckling to Unimak Pass, and (3) the Bering Sea stock--occurring 
throughout the Aleutian Islands and all waters north of Unimak Pass. 
Only the Southeast Alaska stock is considered in this proposed IHA 
because the other stocks are not found in the geographic area under 
consideration.
    There are no subsistence uses of this species; however, as noted 
above, entanglement in fishing gear contributes to human-caused 
mortality and serious injury. Muto et al. (2018) also reports harbor 
porpoise are vulnerable to physical modifications of nearshore habitats 
resulting from urban and industrial development (including waste 
management and nonpoint source runoff) and activities such as 
construction of docks and other over-water structures, filling of 
shallow areas, dredging, and noise (Linnenschmidt et al., 2013).
    Information on harbor porpoise abundance and distribution in Auke 
Bay has not been systematically collected. While sightings of harbor 
porpoise in Statter Harbor are rare, they are an inconspicuous species, 
often traveling alone or in pairs, difficult for marine mammal 
observers to sight, making any approach to a monitoring zone 
potentially difficult to detect. The applicant did not request 
authorization of take of harbor porpoise because they are not known to 
regularly occur in the vicinity of the project site. However, because 
the species has been rarely observed in the area and due to the 
difficulty of implementing mitigation sufficient to avoid incidental 
take of animals that do occur in the area, we have determined it 
appropriate to propose authorization of take of harbor porpoise.

Dall's Porpoise

    Only one stock of Dall's porpoise is currently recognized in 
Alaskan waters--the Alaska stock--with an estimated abundance of 
83,400, although this estimate is outdated (Muto et al., 2019). While 
the Dall's porpoise is generally considered abundant, there is 
insufficient data on population trends to determine whether the 
population is stable, increasing or decreasing (NMFS 2019b).
    Dall's porpoises are widely distributed in the North Pacific Ocean, 
usually in deep oceanic waters (>600 ft/183 m), over the continental 
shelf or along slopes (NMFS 2019b, Muto et al., 2019). They can be 
found along the west coast of the United States ranging from California 
to the Bering Sea in Alaska (NMFS 2019b). There is little data 
regarding Dall's porpoise presence in the project area. Dall's porpoise 
are sighted frequently in southeast Alaska during the summer months but 
Dall's porpoise occurrence is thought to be low compared to summer 
occurrence in the Lynn Canal or Stephens Passage area (Jefferson et 
al., 2019). Systematic surveys of Dall's porpoise abundance and 
distribution have not been

[[Page 55925]]

conducted in Auke Bay specifically, however from 2001-2007 surveys of 
cetaceans in Southeast Alaska were conducted during the spring, summer 
and fall. In-water work will occur from fall into late spring. Dall's 
porpoise were observed in nearby waterways including Stephen's Passage 
and Lynn Canal (Dalheim et al., 2009) and while the species is 
generally in water depths of 600 feet (113 meters) or greater they may 
also occur in shallower waters, (Moran et al., 2018). Dall's porpoises 
have been observed to have strong seasonal patterns with the highest 
number being observed in the spring and the fewest in the fall 
(Dahlheim et al., 2009). Should Dall's porpoise be present within the 
project area it is most likely to be during the spring months based on 
the strong seasonal patterns observed.

California Sea Lion

    The U.S. stock of California sea lions have a wide range, typically 
from the border of the United States and Mexico (NMFS 2019c). During 
the winter males commonly migrate to feeding grounds off California, 
Oregon, Washington, British Columbia and recently Southeast Alaska. 
There is an active unusual mortality event declared for the U.S. stock 
of California sea lions but this is mostly limited to southern 
California. Females and pups on the other hand stay close to breeding 
colonies until the pups have weened. The furthest north females have 
been observed is off the coast of Washington and Oregon during warm 
water years (NMFS 2019c). While California sea lions aren't common in 
Alaska, one was present on the docks in Statter Harbor in 2017 (NOAA 
2017).
    California sea lions feed primarily offshore in coastal waters. 
They are opportunistic predators and eat a variety of prey including 
squid, anchovies, mackerel, rockfish and sardines (NMFS 2019c). 
California sea lion breeding areas are mostly in southern California 
and are not expected to spatially overlap with the project area.

Steller Sea Lion

    The Steller sea lion was listed as a threatened species under the 
ESA in 1990 following declines of 63 percent on certain rookeries since 
1985 and declines of 82 percent since 1960 (55 FR 12645; April 5, 
1990). In 1997, two DPSs of Steller sea lion were identified based on 
differences in genetics, distribution, phenotypic traits, and 
population trends: The Western DPS and Eastern DPS (Fritz et al., 
2013).
    The Eastern DPS (eDPS) is commonly found in the project area waters 
and were most recently surveyed in Southeast Alaska in June-July of 
2015. The current population estimate for the eDPS is 71,562 
individuals of which 52,139 are non-pups and 19,423 are pups. In 
Southeast Alaska the estimated total abundance is 28,594 individuals of 
which 20,756 are non-pups and 7,838 are pups. The eDPS has been 
increasing between 1990 to 2015 with an estimated annual increase of 
4.76 percent for pups and 2.84 percent for non-pups. (Muto et al., 
2018) The Western DPS (wDPS) is found infrequently in the project area 
waters, but have been sighted previously. The current abundance 
estimate for the US portion of the wDPS is 50,983 of which 12,492 were 
pups and 38,491 were non-pups. This is the minimum estimate for only 
the US portion of the wDPS. It is the minimum count because the counts 
were not corrected for animals at sea during the survey. The overall 
trend for the wDPS in Alaska is an annual increase of 1.94 percent for 
non-pups and 1.87 percent for pups. (Muto et al., 2018)
    There is no critical habitat designated for Steller sea lions 
within the action area. The action area is located approximately 12 
nautical miles (22.22 kilometers) from around Benjamin Island, well 
outside of the 3,000-ft (914.4-m) designated critical habitat boundary 
designation.
    Steller sea lions occur in Auke Bay in winter on an intermittent 
basis, but their genetic and stock-designation identities are rarely 
known: Individuals are indistinguishable unless sea lions are branded 
(and the brand is observed). Satellite-tagged individual animals from 
the Benjamin Island haulout and Auke Bay were observed multiple times 
between November 2010 and January 2011 (Fadely 2011), and the Auke Bay 
boating community frequently observes Steller sea lions moving to and 
from the haulout complex into Auke Bay.
    From 2013-2017, Steller sea lions have been documented in Auke Bay 
travelling as individuals or in herds of 50 to an estimated 120+ 
animals, during every month of the winter season. During winter 2015-
2016, Steller sea lions foraged aggressively on young herring and 1-2-
year-old Walleye pollock for over 20 days, continuously. Some sea lions 
were also observed consuming small flatfish, likely yellowfin sole, 
harvested from the seafloor (depth 25-45 m), during this period. While 
no sea lions were observed hauled out on beaches or structures in the 
harbor, large rafts of 20-50 animals formed and rested in the outer 
harbor area between foraging bouts. Simultaneous surface counts of 121 
individual sea lions suggests that likely upwards of 200 animals or 
more were targeting prey in Statter Harbor during herring aggregation 
events. These 121 to 200 animals comprise roughly 20 to 30 percent of 
the animals typically found at the Benjamin Island and Little Island 
haulout complexes during winter months. (Ridgway pers. observ.)
    Only three individual, branded wDPS Steller sea lions have been 
observed at Benjamin Island, the closest haulout, from 2003-2006 with a 
maximum of 3 sightings per individual. No branded wDPS individuals have 
been observed in the ADF&G surveys from 2007-2016. The 2007 ADF&G 
surveys offer the most abundant data for Steller sea lion counts at 
Benjamin Island. A total of 11 surveys were conducted between January 
and July 2017, ranging from 0-768 Steller sea lions, with an average 
count of 404 individuals. In 2007 no wDPS animals were observed. While 
it is possible an individual from the wDPS may be at the Benjamin 
Island haulout, it is rare, and none have been documented at this 
haulout for the last decade (Jemison pers. comm. 2017).
    Although recent data in the northern part of the eastern DPS 
indicate movement of western sea lions east of the 144[deg] line, the 
mixed part of the range remains small (Jemison et al., 2013). Based on 
observations by ADF&G over the last decade this project is unlikely to 
impact wDPS individuals. An updated paper by Hastings et al. (in press) 
estimates that in the area surrounding Auke Bay, it is appropriate to 
assume a maximum of 18 percent of the sighted animals would be from the 
listed Western DPS.

Harbor Seal

    The Lynn Canal/Stephens Passage stock is found in the project area 
waters. The current population estimate for the Lynn Canal/Stephens 
Passage stock is 9,478 individuals, and the 5-year trend estimate is -
176. The probability of decrease of this stock is 0.71, indicating that 
evidence suggests that the stock is declining, however 9 of the 12 
Alaska harbor seal stocks are showing a trend of increasing populations 
(Muto et al., 2018). Typically harbor seals will stay within 16 miles 
(25 km) of shore, but they have been found up to 62 miles (100 km) from 
the shore (Klinkhart et al., 2008). Harbor seal movement is highly 
variable, with no seasonal patterns identified.
    Harbor seals use a variety of terrestrial sites to haul out for 
resting (year-round), pupping (May-July), and molting (August-
September) including tidal and intertidal reefs, beaches, sand bars, 
and glacial/sea ice (Sease 1992; Klinkhart et al., 2008). Some sites 
have traditional/historic value for pupping and molting while others 
are used as temporary

[[Page 55926]]

resting sites during seasonal foraging trips.
    Harbor seals are residents of the project area and observed within 
the harbor on a regular basis and can be found within the immediate 
project vicinity on a daily basis. Over the last three winters, a group 
of up to 12 harbor seals has been observed in inner Statter Harbor near 
the harbormaster building along with 1-2 dispersed seals near the Auke 
Creek shoreline (Kate Wynne pers. observ.). Additionally, other counts 
from 2014-2016 recorded 2-16 animals within Statter Harbor. Up to 52 
individual seals have been photographed simultaneously hauled out on 
the nearby dock at Fishermen's Bend, located in the northwest corner of 
Statter harbor (Ridgway unpubl. Data). It is assumed that the majority 
of animals that haul out on the nearby floats at Fishermen's Bend are 
likely to go under water and resurface throughout the duration of the 
project. However, further clarification on the number of individual 
seals likely to occur in the project area is difficult as harbor seals 
are not easily identifiable at an individual level.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans).
    Subsequently, NMFS (2018) described generalized hearing ranges for 
these marine mammal hearing groups. Generalized hearing ranges were 
chosen based on the approximately 65 decibel (dB) threshold from the 
normalized composite audiograms, with the exception for lower limits 
for low-frequency cetaceans where the lower bound was deemed to be 
biologically implausible and the lower bound from Southall et al. 
(2007) retained. Marine mammal hearing groups and their associated 
hearing ranges are provided in Table 3.

                                      Table 3--Marine Mammal Hearing Groups
                                                  [NMFS, 2018]
----------------------------------------------------------------------------------------------------------------
                     Hearing group                                     Generalized hearing range *
----------------------------------------------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen whales)...........  7 Hz to 35 kHz.
Mid-frequency (MF) cetaceans (dolphins, toothed whales,  150 Hz to 160 kHz.
 beaked whales, bottlenose whales).
High-frequency (HF) cetaceans (true porpoises, Kogia,    275 Hz to 160 kHz.
 river dolphins, cephalorhynchid, Lagenorhynchus
 cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) (true seals)........  50 Hz to 86 kHz.
Otariid pinnipeds (OW) (underwater) (sea lions and fur   60 Hz to 39 kHz.
 seals).
----------------------------------------------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a composite (i.e., all species within the
  group), where individual species' hearing ranges are typically not as broad. Generalized hearing range chosen
  based on ~65 dB threshold from normalized composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
eight marine mammal species (five cetacean and three pinniped (two 
otariid and one phocid) species) have the reasonable potential to co-
occur with the proposed survey activities. Please refer to Table 2. Of 
the cetacean species that may be present, two are classified as low-
frequency cetaceans (i.e., all mysticete species), one is classified as 
mid-frequency cetaceans (killer whale), and two are classified as high-
frequency cetaceans (harbor and Dall's porpoise).

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity may impact marine mammals and 
their habitat. The Estimated Take by Incidental Harassment section 
later in this document includes a quantitative analysis of the number 
of individuals that are expected to be taken by this activity. The 
Negligible Impact Analysis and Determination section considers the 
content of this section, the Estimated Take by Incidental Harassment 
section, and the Proposed Mitigation section, to draw conclusions 
regarding the likely impacts of these activities on the reproductive 
success or survivorship of individuals and how those impacts on 
individuals are likely to impact marine mammal species or stocks.

Description of Sound Sources

    The marine soundscape is comprised of both ambient and 
anthropogenic sounds. Ambient sound is defined as the all-encompassing 
sound in a given place and is usually a composite of sound from many 
sources both near and far (ANSI 1994). The sound level of an area is 
defined by the total acoustical energy being generated by known and 
unknown sources. These sources may include physical (e.g., waves, wind, 
precipitation, earthquakes, ice, atmospheric sound), biological (e.g., 
sounds produced by marine mammals, fish, and invertebrates), and 
anthropogenic sound (e.g., vessels, dredging, aircraft, construction).
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea

[[Page 55927]]

floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals.
    In-water construction activities associated with the project would 
include vibratory pile driving and removal, coupled with down the hole 
drilling, and potential impact pile driving. The sounds produced by 
these activities fall into one of two general sound types: Impulsive 
and non-impulsive. Impulsive sounds (e.g., explosions, gunshots, sonic 
booms, impact pile driving) are typically transient, brief (less than 1 
second), broadband, and consist of high peak sound pressure with rapid 
rise time and rapid decay (ANSI 1986; NIOSH 1998; ANSI 2005; NMFS 
2018). Non-impulsive sounds (e.g. aircraft, machinery operations such 
as drilling or dredging, vibratory pile driving, and active sonar 
systems) can be broadband, narrowband or tonal, brief or prolonged 
(continuous or intermittent), and typically do not have the high peak 
sound pressure with raid rise/decay time that impulsive sounds do (ANSI 
1995; NIOSH 1998; NMFS 2018). The distinction between these two sound 
types is important because they have differing potential to cause 
physical effects, particularly with regard to hearing (e.g., Ward 1997 
in Southall et al., 2007).
    Two types of pile hammers would be used on this project: Impact and 
vibratory. Impact hammers operate by repeatedly dropping a heavy piston 
onto a pile to drive the pile into the substrate. Sound generated by 
impact hammers is characterized by rapid rise times and high peak 
levels, a potentially injurious combination (Hastings and Popper 2005). 
Vibratory hammers install piles by vibrating them and allowing the 
weight of the hammer to push them into the sediment. Vibratory hammers 
produce significantly less sound than impact hammers. Peak SPLs may be 
180 dB or greater, but are generally 10 to 20 dB lower than SPLs 
generated during impact pile driving of the same-sized pile (Oestman et 
al., 2009). Rise time is slower, reducing the probability and severity 
of injury, and sound energy is distributed over a greater amount of 
time (Nedwell and Edwards 2002; Carlson et al., 2005).
    Drilling would be conducted using a down-the-hole drill inserted 
through the hollow steel piles. A down-the-hole drill is a drill bit 
that drills through the bedrock using a pulse mechanism that functions 
at the bottom of the hole. This pulsing bit breaks up rock to allow 
removal of debris and insertion of the pile. The head extends so that 
the drilling takes place below the pile. The pulsing sounds produced by 
the down-the-hole drilling method are continuous, however this method 
likely increases sound attenuation because the noise is primarily 
contained within the steel pile and below ground rather than impact 
hammer driving methods which occur at the top of the pile (R&M 2016).
    The likely or possible impacts of the City of Juneau's proposed 
activity on marine mammals could involve both non-acoustic and acoustic 
stressors. Potential non-acoustic stressors could result from the 
physical presence of the equipment and personnel; however, any impacts 
to marine mammals are expected to primarily be acoustic in nature. 
Acoustic stressors include effects of heavy equipment operation during 
pile installation and removal and drilling.

Acoustic Effects

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving and removal and down the hole drilling is 
the primary means by which marine mammals may be harassed from the City 
of Juneau's specified activity. In general, animals exposed to natural 
or anthropogenic sound may experience physical and psychological 
effects, ranging in magnitude from none to severe (Southall et al., 
2007). In general, exposure to pile driving and drilling noise has the 
potential to result in auditory threshold shifts and behavioral 
reactions (e.g., avoidance, temporary cessation of foraging and 
vocalizing, changes in dive behavior). Exposure to anthropogenic noise 
can also lead to non-observable physiological responses such an 
increase in stress hormones. Additional noise in a marine mammal's 
habitat can mask acoustic cues used by marine mammals to carry out 
daily functions such as communication and predator and prey detection. 
The effects of pile driving and drilling noise on marine mammals are 
dependent on several factors, including, but not limited to, sound type 
(e.g., impulsive vs. non-impulsive), the species, age and sex class 
(e.g., adult male vs. mom with calf), duration of exposure, the 
distance between the pile and the animal, received levels, behavior at 
time of exposure, and previous history with exposure (Wartzok et al., 
2004; Southall et al., 2007). Here we discuss physical auditory effects 
(threshold shifts) followed by behavioral effects and potential impacts 
on habitat.
    NMFS defines a noise-induced threshold shift (TS) as a change, 
usually an increase, in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). The amount of 
threshold shift is customarily expressed in dB. A TS can be permanent 
or temporary. As described in NMFS (2018), there are numerous factors 
to consider when examining the consequence of TS, including, but not 
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), likelihood an individual would be exposed for a long enough 
duration or to a high enough level to induce a TS, the magnitude of the 
TS, time to recovery (seconds to minutes or hours to days), the 
frequency range of the exposure (i.e., spectral content), the hearing 
and vocalization frequency range of the exposed species relative to the 
signal's frequency spectrum (i.e., how animal uses sound within the 
frequency band of the signal; e.g., Kastelein et al. 2014), and the 
overlap between the animal and the source (e.g., spatial, temporal, and 
spectral).
    Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). Available data from 
humans and other terrestrial mammals indicate that a 40 dB threshold 
shift approximates PTS onset (see Ward et al., 1958, 1959; Ward 1960; 
Kryter et al., 1966; Miller 1974; Ahroon et al., 1996; Henderson et 
al., 2008). PTS levels for marine mammals are estimates, as with the 
exception of a single study unintentionally inducing PTS in a harbor 
seal (Kastak et al., 2008), there are no empirical data measuring PTS 
in marine mammals largely due to the fact that, for various ethical 
reasons, experiments involving anthropogenic noise exposure at levels 
inducing PTS are not typically pursued or authorized (NMFS 2018).
    Temporary Threshold Shift (TTS)--A temporary, reversible increase 
in the threshold of audibility at a specified frequency or portion of 
an individual's hearing range above a previously established reference 
level (NMFS 2018). Based on data from cetacean TTS measurements (see 
Southall et al.,

[[Page 55928]]

2007), a TTS of 6 dB is considered the minimum threshold shift clearly 
larger than any day-to-day or session-to-session variation in a 
subject's normal hearing ability (Schlundt et al., 2000; Finneran et 
al., 2000, 2002). As described in Finneran (2016), marine mammal 
studies have shown the amount of TTS increases with cumulative sound 
exposure level (SELcum) in an accelerating fashion: At low exposures 
with lower SELcum, the amount of TTS is typically small and the growth 
curves have shallow slopes. At exposures with higher SELcum, the growth 
curves become steeper and approach linear relationships with the noise 
SEL.
    Depending on the degree (elevation of threshold in dB), duration 
(i.e., recovery time), and frequency range of TTS, and the context in 
which it is experienced, TTS can have effects on marine mammals ranging 
from discountable to serious (similar to those discussed in auditory 
masking, below). For example, a marine mammal may be able to readily 
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal 
is traveling through the open ocean, where ambient noise is lower and 
there are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during time when 
communication is critical for successful mother/calf interactions could 
have more serious impacts. We note that reduced hearing sensitivity as 
a simple function of aging has been observed in marine mammals, as well 
as humans and other taxa (Southall et al., 2007), so we can infer that 
strategies exist for coping with this condition to some degree, though 
likely not without cost.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus 
leucas), harbor porpoise, and Yangtze finless porpoise (Neophocoena 
asiaeorientalis)) and five species of pinnipeds exposed to a limited 
number of sound sources (i.e., mostly tones and octave-band noise) in 
laboratory settings (Finneran 2015). TTS was not observed in trained 
spotted (Phoca largha) and ringed (Pusa hispida) seals exposed to 
impulsive noise at levels matching previous predictions of TTS onset 
(Reichmuth et al., 2016). In general, harbor seals and harbor porpoises 
have a lower TTS onset than other measured pinniped or cetacean species 
(Finneran 2015). Additionally, the existing marine mammal TTS data come 
from a limited number of individuals within these species. No data are 
available on noise-induced hearing loss for mysticetes. For summaries 
of data on TTS in marine mammals or for further discussion of TTS onset 
thresholds, please see Southall et al. (2007), Finneran and Jenkins 
(2012), Finneran (2015), and Table 5 in NMFS (2018). Installing piles 
requires a combination of vibratory pile driving and down the hole 
drilling, as well as potential impact pile driving. For the project, 
these activities would not occur at the same time and there would 
likely be pauses in activities producing the sound during each day. 
Given these pauses and that many marine mammals are likely moving 
through the action area and not remaining for extended periods of time, 
the potential for TS declines.
    Behavioral Harassment--Exposure to noise from pile driving and 
removal and drilling also has the potential to behaviorally disturb 
marine mammals. Available studies show wide variation in response to 
underwater sound; therefore, it is difficult to predict specifically 
how any given sound in a particular instance might affect marine 
mammals perceiving the signal. If a marine mammal does react briefly to 
an underwater sound by changing its behavior or moving a small 
distance, the impacts of the change are unlikely to be significant to 
the individual, let alone the stock or population. However, if a sound 
source displaces marine mammals from an important feeding or breeding 
area for a prolonged period, impacts on individuals and populations 
could be significant (e.g., Lusseau and Bejder 2007; Weilgart 2007; NRC 
2005).
    Disturbance may result in changing durations of surfacing and 
dives, number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities; changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping); avoidance of areas where sound sources are located. 
Pinnipeds may increase their haulout time, possibly to avoid in-water 
disturbance (Thorson and Reyff 2006). Behavioral responses to sound are 
highly variable and context-specific and any reactions depend on 
numerous intrinsic and extrinsic factors (e.g., species, state of 
maturity, experience, current activity, reproductive state, auditory 
sensitivity, time of day), as well as the interplay between factors 
(e.g., Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 
2007; Weilgart 2007; Archer et al., 2010). Behavioral reactions can 
vary not only among individuals but also within an individual, 
depending on previous experience with a sound source, context, and 
numerous other factors (Ellison et al., 2012), and can vary depending 
on characteristics associated with the sound source (e.g., whether it 
is moving or stationary, number of sources, distance from the source). 
In general, pinnipeds seem more tolerant of, or at least habituate more 
quickly to, potentially disturbing underwater sound than do cetaceans, 
and generally seem to be less responsive to exposure to industrial 
sound than most cetaceans. Please see Appendices B-C of Southall et al. 
(2007) for a review of studies involving marine mammal behavioral 
responses to sound.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the appearance of secondary 
indicators (e.g., bubble nets or sediment plumes), or changes in dive 
behavior. As for other types of behavioral response, the frequency, 
duration, and temporal pattern of signal presentation, as well as 
differences in species sensitivity, are likely contributing factors to 
differences in response in any given circumstance (e.g., Croll et al., 
2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko et al., 
2007). A determination of whether foraging disruptions incur fitness 
consequences would require information on or estimates of the energetic 
requirements of the affected individuals and the relationship between 
prey availability, foraging effort and success, and the life history 
stage of the animal.
    In 2016, the Alaska Department of Transportation and Public 
Facilities (ADOT&PF) documented observations of marine mammals during 
construction activities (i.e., pile driving and down-hole drilling) at 
the Kodiak Ferry Dock (80 FR 60636; October 7, 2015). In the marine 
mammal monitoring report for that project (ABR 2016), 1,281 Steller sea 
lions were observed within the Level B disturbance zone during pile 
driving or drilling (i.e., documented as Level B harassment take). Of 
these, 19 individuals demonstrated an alert behavior, 7 were fleeing, 
and 19 swam away from the project site. All other animals (98 percent) 
were engaged in activities such as milling, foraging, or fighting and 
did not change their behavior. In addition, two sea lions approached 
within 20 meters of active vibratory pile driving activities. Three 
harbor seals were observed within the disturbance zone during pile 
driving activities; none of them displayed disturbance behaviors. 
Fifteen killer

[[Page 55929]]

whales and three harbor porpoise were also observed within the Level B 
harassment zone during pile driving. The killer whales were travelling 
or milling while all harbor porpoises were travelling. No signs of 
disturbance were noted for either of these species. Given the 
similarities in activities and habitat and the fact the same species 
are involved, we expect similar behavioral responses of marine mammals 
to the specified activity. That is, disturbance, if any, is likely to 
be temporary and localized (e.g., small area movements). Monitoring 
reports from other recent pile driving and down-the-hole drilling 
projects in Alaska have observed similar behaviors (for example, the 
Biorka Island Dock Replacement Project).
    Masking--Sound can disrupt behavior through masking, or interfering 
with, an animal's ability to detect, recognize, or discriminate between 
acoustic signals of interest (e.g., those used for intraspecific 
communication and social interactions, prey detection, predator 
avoidance, navigation) (Richardson et al., 1995). Masking occurs when 
the receipt of a sound is interfered with by another coincident sound 
at similar frequencies and at similar or higher intensity, and may 
occur whether the sound is natural (e.g., snapping shrimp, wind, waves, 
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar, 
seismic exploration) in origin. The ability of a noise source to mask 
biologically important sounds depends on the characteristics of both 
the noise source and the signal of interest (e.g., signal-to-noise 
ratio, temporal variability, direction), in relation to each other and 
to an animal's hearing abilities (e.g., sensitivity, frequency range, 
critical ratios, frequency discrimination, directional discrimination, 
age or TTS hearing loss), and existing ambient noise and propagation 
conditions. Masking of natural sounds can result when human activities 
produce high levels of background sound at frequencies important to 
marine mammals. Conversely, if the background level of underwater sound 
is high (e.g., on a day with strong wind and high waves), an 
anthropogenic sound source would not be detectable as far away as would 
be possible under quieter conditions and would itself be masked. 
Statter Harbor hosts numerous recreational and commercial vessels; 
therefore, background sound levels in the harbor are already elevated.
    Airborne Acoustic Effects--Pinnipeds that occur near the project 
site could be exposed to airborne sounds associated with pile driving 
and removal and down-the-hole drilling that have the potential to cause 
behavioral harassment, depending on their distance from pile driving 
activities. Cetaceans are not expected to be exposed to airborne sounds 
that would result in harassment as defined under the MMPA.
    Airborne noise would primarily be an issue for pinnipeds that are 
swimming or hauled out near the project site within the range of noise 
levels elevated above the acoustic criteria. We recognize that 
pinnipeds in the water could be exposed to airborne sound that may 
result in behavioral harassment when looking with their heads above 
water. Most likely, airborne sound would cause behavioral responses 
similar to those discussed above in relation to underwater sound. For 
instance, anthropogenic sound could cause hauled-out pinnipeds to 
exhibit changes in their normal behavior, such as reduction in 
vocalizations, or cause them to temporarily abandon the area and move 
further from the source. However, these animals would previously have 
been `taken' because of exposure to underwater sound above the 
behavioral harassment thresholds, which are in all cases larger than 
those associated with airborne sound. Thus, the behavioral harassment 
of these animals is already accounted for in these estimates of 
potential take. Therefore, we do not believe that authorization of 
incidental take resulting from airborne sound for pinnipeds is 
warranted, and airborne sound is not discussed further here.

Marine Mammal Habitat Effects

    The City of Juneau's construction activities in Statter Harbor 
could have localized, temporary impacts on marine mammal habitat and 
their prey by increasing in-water sound pressure levels and slightly 
decreasing water quality. Increased noise levels may affect acoustic 
habitat (see masking discussion above) and adversely affect marine 
mammal prey in the vicinity of the project area (see discussion below).
    Construction activities are of short duration and would likely have 
temporary impacts on marine mammal habitat through increases in 
underwater and airborne sound. These sounds would not be detectable at 
the nearest known Steller sea lion haulouts, and all known harbor seal 
haulouts are well beyond the maximum distance of predicted in-air 
acoustical disturbance.
    In-water pile driving, pile removal, and drilling activities would 
also cause short-term effects on water quality due to increased 
turbidity. Dispersal of suspended sediments produced by project 
activities could vary from moderate to rapid rates depending on tidal 
stage at the time of the activities. The City of Juneau would employ 
standard construction best management practices (see section 10 in 
application), thereby reducing any impacts. Therefore, the impact from 
increased turbidity levels is expected to be discountable.

In-Water Construction Effects on Potential Foraging Habitat

    The area likely impacted by the project is relatively small 
compared to the available habitat in neighboring Fritz Cove or Favorite 
Channel (e.g., most of the impacted area is limited to the northern and 
eastern portions of Auke Bay) and does not include any BIAs, ESA-
designated critical habitat, or any other areas of known significance. 
Pile installation/removal and drilling may temporarily increase 
turbidity resulting from suspended sediments. Any increases would be 
temporary, localized, and minimal. The City of Juneau must comply with 
state water quality standards during these operations by limiting the 
extent of turbidity to the immediate project area. In general, 
turbidity associated with pile installation is localized to about a 25-
foot radius around the pile (Everitt et al., 1980). Cetaceans are not 
expected to be close enough to the project pile driving areas to 
experience effects of turbidity, and any pinnipeds would be transiting 
the area and could avoid localized areas of turbidity. Therefore, the 
impact from increased turbidity levels is expected to be discountable 
to marine mammals. Furthermore, pile driving and removal at the project 
site would not obstruct movements or migration of marine mammals.
    Avoidance by potential prey (i.e., fish) of the immediate area due 
to the temporary loss of this foraging habitat is also possible. The 
duration of fish avoidance of this area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated. Any behavioral avoidance by fish of the 
disturbed area would still leave significantly large areas of fish and 
marine mammal foraging habitat in the nearby vicinity of the other 
channels and bays immediately adjacent to Auke Bay.
    The duration of the construction activities is relatively short. 
The construction window is for a maximum of 23 days and during each 
day, construction activities would occur for a maximum of 12 hours. 
Impacts to habitat and prey are expected to be minimal based on the 
short duration of activities.

[[Page 55930]]

In-Water Construction Effects on Potential Prey

    Construction activities would produce continuous (i.e., vibratory 
pile driving and down-the-hole drilling) and pulsed (i.e., impact 
driving) sounds. Fish react to sounds that are especially strong and/or 
intermittent low-frequency sounds. Short duration, sharp sounds can 
cause overt or subtle changes in fish behavior and local distribution. 
Hastings and Popper (2005) identified several studies that suggest fish 
may relocate to avoid certain areas of sound energy. Additional studies 
have documented effects of pile driving on fish, although several are 
based on studies in support of large, multiyear bridge construction 
projects (e.g., Scholik and Yan 2001, 2002; Popper and Hastings 2009). 
Sound pulses at received levels of 160 dB may cause subtle changes in 
fish behavior. SPLs of 180 dB may cause noticeable changes in behavior 
(Pearson et al., 1992; Skalski et al., 1992). SPLs of sufficient 
strength have been known to cause injury to fish and fish mortality.
    The most likely impact to fish from pile driving and drilling 
activities at the project area would be temporary behavioral avoidance 
of the area. The duration of fish avoidance of this area after pile 
driving stops is unknown, but a rapid return to normal recruitment, 
distribution and behavior is anticipated. In general, impacts to marine 
mammal prey species are expected to be minor and temporary due to the 
short timeframe for the project.
    Construction activities, in the form of increased turbidity, have 
the potential to adversely affect forage fish and juvenile salmonid 
outmigratory routes in the project area. Both herring and salmon form a 
significant prey base for Steller sea lions, herring is a primary prey 
species of humpback whales, and both herring and salmon are components 
of the diet of many other marine mammal species that occur in the 
project area. Increased turbidity is expected to occur in the immediate 
vicinity of construction activities. However, suspended sediments and 
particulates are expected to dissipate quickly within a single tidal 
cycle. Given the limited area affected and high tidal dilution rates 
any effects on forage fish and salmon are expected to be minor or 
negligible. In addition, best management practices would be in effect, 
which would limit the extent of turbidity to the immediate project 
area. Finally, exposure to turbid waters from construction activities 
is not expected to be different from the current exposure; fish and 
marine mammals in Auke Bay are routinely exposed to substantial levels 
of suspended sediment from ongoing construction in the harbor.
    In summary, given the short daily duration of sound associated with 
individual pile driving and drilling events and the relatively small 
areas being affected, pile driving and drilling activities associated 
with the proposed action are not likely to have a permanent, adverse 
effect on any fish habitat, or populations of fish species. Thus, we 
conclude that impacts of the specified activity are not likely to have 
more than short-term adverse effects on any prey habitat or populations 
of prey species. Further, any impacts to marine mammal habitat are not 
expected to result in significant or long-term consequences for 
individual marine mammals, or to contribute to adverse impacts on their 
populations.

Estimated Take

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

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2012). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 [mu]Pa (rms) for continuous (e.g., 
vibratory pile-driving, drilling) and above 160 dB re 1 [mu]Pa (rms) 
for non-explosive impulsive (e.g., seismic airguns) or intermittent 
(e.g., scientific sonar) sources.
    The City of Juneau's proposed activity includes the use of 
continuous

[[Page 55931]]

(vibratory pile driving/removal and down the hole drilling) and 
impulsive (impact pile driving) sources, and therefore the 120 and 160 
dB re 1 [mu]Pa (rms) thresholds 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) (NMFS 2018) identifies dual criteria to 
assess auditory injury (Level A harassment) to five different marine 
mammal groups (based on hearing sensitivity) as a result of exposure to 
noise from two different types of sources (impulsive or non-impulsive). 
The City of Juneau's proposed activity includes the use of impulsive 
(impact pile driving) and non-impulsive (vibratory pile driving/removal 
and down the hole drilling) sources.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 4--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 [mu]Pa, and cumulative sound exposure level (LE) has
  a reference value of 1[mu]Pa\2\s. In this Table, thresholds are abbreviated to reflect American National
  Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
  frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
  being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
  hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
  designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
  that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
  exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
  is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the proposed project. 
Marine mammals are expected to be affected via sound generated by the 
primary components of the project (i.e., impact pile driving, vibratory 
pile driving and removal and down-the-hole drilling).
    In order to calculate distances to the Level A and Level B 
harassment thresholds for piles of various sizes being used in this 
project, NMFS used acoustic monitoring data from other locations. Note 
that piles of differing sizes have different sound source levels. It is 
anticipated all of the piles will require drilling for rock anchors and 
will be installed at the rate of a single pile per day.
    Vibratory removal--The closest known measurements of vibratory pile 
removal similar to this project are from the Kake Ferry Terminal 
project for vibratory extraction of an 18-inch steel pile. The 
extraction of 18-inch steel pipe piles using a vibratory hammer 
resulted in underwater noise levels reaching 152.4 dBRMS at 55.8 feet 
(17 meters) (Denes et al., 2016). The pile diameters for the proposed 
project are smaller, thus the use of noise levels associated with the 
pile extraction at Kake are conservative.
    Down the hole drilling--Little source level data are available for 
down-the-hole drilling. Denes et al. (2016) measured sound emanating 
from the drilling of 24-in (61-cm) piles at Kodiak and calculated a 
median SPL of 166.3 dB (at 10 m) which was used to calculate the PTS 
onset isopleths. Denes et al. (2016) also noted a transmission loss 
coefficient of 18.9 for drilling suggesting high attenuation when 
drilling below the seafloor. As the activity proposed will not occur in 
the same location as the Denes et al. measurements, NMFS is using a 
transmission loss coefficient of 15 in this proposed notice.
    Vibratory driving--The closest known measurements of sound levels 
for vibratory pile installation of 16-inch (41-cm) steel piles are from 
the U.S. Navy Proxy Sound Source Study for projects in Puget Sound. 
Based on the projects analyzed it was determined that 16- to 24-inch 
(41- to 61-cm) piles exhibited similar sound source levels for projects 
in Puget Sound resulting in a recommended source level of 161 dB RMS at 
33 feet (10 m) for piles diameters ranging from 16- to 24-inches (41- 
to 61-cm) (U.S. Navy 2015). However, as each pile that will be driven 
through vibratory driving will also utilize down the hole drilling, 
within the same day, the ensonified area for the down the hole 
drilling, which is larger and potentially a more conservative estimate, 
was used.
    Impact driving--For impact pile driving of 16-inch (41-cm) piles, 
sound measurements were used from the literature review in Appendix H 
of the AKDOT&PF study (Yurk et al., 2015) for 24-inch (61-cm) piles 
driven in the Columbia River with a diesel impact hammer. To estimate 
the sound source levels of 16-inch (41-cm) piles data for the 24-inch 
(61-cm) piles were used as the available data for 16-inch piles did not 
report a peak level, thus these noise levels used in this notice are 
likely overestimating the acoustic isopleths.
    When the NMFS Technical Guidance (2018) 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

[[Page 55932]]

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 the pile driving/removal 
and down the hole drilling proposed for this project, the NMFS User 
Spreadsheet predicts the distance at which, if a marine mammal remained 
at that distance the whole duration of the activity, it would incur 
PTS. Inputs used in the User Spreadsheet, and the resulting isopleths 
are reported below.

                                                          Table 5--NMFS User Spreadsheet Inputs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         Down the hole
                                        Vibratory driving       Vibratory removal           drilling                                   Impact driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used...............  A. (1) Non-impulsive,   A. (1) Non-impulsive,   A. (1) Non-impulsive,  Spreadsheet Tab Used.  E. (1) Impulsive,
                                      continuous.             continuous.             continuous.                                   intermittent.
Source Level (RMS SPL).............  161...................  152.4.................  166.3................  Source level (Single   175.
                                                                                                             shot SEL).
Weighting Factor Adjustment (kHz)..  2.5...................  2.5...................  2.5..................  Weighting Factor       2.
                                                                                                             Adjustment (kHz).
Number of piles in 24 hours........  2.....................  2.....................  1....................  Number of strikes per  500.
                                                                                                             pile.
Activity Duration (min) to drive 1   360...................  360...................  720..................  Number of piles per    1.
 pile.                                                                                                       day.
Propagation (xLogR)................  15....................  15....................  15...................  Propagation (xLogR)..  15.
Distance of source level             10....................  17....................  10...................  Distance of source     10.
 measurement (meters).                                                                                       level measurement
                                                                                                             (meters).
Other factors if using different     ......................  ......................  .....................  Source level (PK SPL)  205.
 tab for other source.
                                                                                                            Distance of source     10.
                                                                                                             level measurement
                                                                                                             (meters).
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                                         Table 6--NMFS User Spreadsheet Outputs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 PTS isopleth  (meters)
---------------------------------------------------------------------------------------------------------------------------------------------------------
                                         Low- frequency          Mid- frequency         High- frequency
            Source type                     cetaceans               cetaceans              cetaceans          Phocid  pinnipeds      Otariid  pinnipeds
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory driving..................  35.8..................  3.2...................  52.9.................  21.8.................  1.5
Vibratory removal..................  16.3..................  1.4...................  24.0.................  9.9..................  0.7
Down the hole drilling.............  79.5..................  7.0...................  117.6................  48.3.................  3.4
Impact driving (SEL/PK)............  184.2/1.2.............  6.6/NA................  219.5/15.8...........  98.6/1.4.............  7.2/NA
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                          Level B behavioral harassment isopleth (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory driving..................                                                        5,411.7
Vibratory removal..................                                                        2,457.2
Down the hole drilling.............                                                       12,022.64
Impact driving.....................                                                         1,000
--------------------------------------------------------------------------------------------------------------------------------------------------------

Marine Mammal Occurrence

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations.
    Reliable densities are not available for Statter Harbor or the Auke 
Bay area. Generalized densities for the North Pacific are not 
applicable given the high variability in occurrence and density at 
specific inlets and harbors. Therefore, the applicant consulted 
opportunistic sightings data from oceanographic surveys in Auke Bay and 
sightings from Auke Bay Marine Station observation pier for Statter 
Harbor to arrive at a number of animals expected to occur within the 
harbor per day. For humpback whales, it is assumed that a maximum of 
four animals per day are likely to occur in the harbor. For Steller sea 
lions, the potential maximum daily occurrence of animals is 121 
individuals within the harbor. For harbor seals, the maximum daily 
occurrence of animals is 52 individuals. For Dall's porpoises, it was 
assumed a large pod (20 individuals) might occur in the project area 
once per month in the spring months of March, April, and May. For 
harbor porpoises, it was assumed that up to one pair may enter the 
project area daily. For killer whales, it was conservatively assumed 
that up to one pod of resident killer whales (41 individuals) and one 
pod of transient killer whales (14 killer whales) might enter Auke Bay 
over the course of the project. It was assumed that one minke

[[Page 55933]]

whale might enter the bay per month across the eight months when work 
could potentially be conducted. Take of California sea lions have been 
requested on a precautionary basis and it is assumed no more than one 
sea lion per day of in-water work would enter Auke Bay.

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate. Because reliable 
densities are not available, the applicant requests take based on the 
above mentioned maximum number of animals that may occur in the harbor 
per day multiplied by the number of days of the activity. For species 
occurring less frequently in the area, some take estimates were 
calculated based on potential monthly occurrence. The applicant varied 
these calculations based on certain factors.
    Humpback whales--Because humpback whale individuals of different 
DPS (natal) origin are indistinguishable from one another (unless fluke 
patterns are linked to the individual in both feeding and breeding 
ground), the frequency of occurrence of animals by DPS is only 
estimated using the DPS ratio, based upon the assumption that the ratio 
is consistent throughout the Southeast Alaska region (Wade et al., 
2016). Work is expected to occur over 23 days and will involve a 
mixture of vibratory pile driving and drilling each day. Based on the 
available information and the extent of the Level B harassment zone it 
is estimated up to 4 humpback whales could be exposed to elevated noise 
during each day of pile driving and drilling. Using a daily potential 
maximum rate of four humpback whales per day, the project could take up 
to 92 humpback whales. Based on the allocation by DPS expected in the 
project area, it is assumed 6.1 percent of the humpbacks sighted would 
be from the ESA-listed Mexico DPS, or a potential 6 takes. No Level A 
harassment takes are requested for humpback whales as the Level A 
harassment zones are small and shutdown measures can be implemented 
prior to any humpback whales enter Level A harassment zones.
    Steller sea lions--Using a potential daily maximum rate, the 
project could take up to 121 Steller sea lions each day of pile driving 
activities due to the large Level B harassment zones. The maximum daily 
count of 121 was used to make this determination as Steller sea lions 
have been observed in large herds within vicinity of the harbor in 
excess of seven days when prey is abundant and the Level B harassment 
zones are large and in relatively close proximity to Benjamin Island 
(~22 km from project site). Thus, during these times it is likely that 
the rate of taking would be higher as the animals will be counted more 
than once if they dive and/or leave and re-enter the monitoring zone. 
On other days when dense groups are not present, fewer takes will be 
encountered, and it is assumed the overall take levels will even out. 
While there are a small number of resident harbor seals, it is 
anticipated there will be larger numbers of Steller sea lion takes, due 
to the large herds they have been observed in, the large size of the 
Level B harassment zones (up to 12.1 km) and the relative proximity to 
an established haulout at Benjamin Island. While the Level B harassment 
zones for the first phase of construction were generally smaller, much 
of the larger zones in this second phase are truncated due to land 
masses. Further, take numbers are estimated based on the largest group 
observed rafting in the Auke Bay vicinity and thus is considered an 
appropriate estimate for this phase as well.
    Assuming 121 Steller sea lion takes per day, the total requested 
number of Steller sea lion takes for 23 days of work is 2,783 Steller 
sea lions. Based on the recently published literature ascribing sighted 
Steller sea lions in the zone of mixing to an allocated DPS, it is 
assumed 18 percent of the total takes, or 501 individuals, would be 
from the ESA-listed Western DPS. No Level A harassment takes are 
requested for Steller sea lions as the Level A harassment zones are 
small and shutdown measures can be implemented prior to Steller sea 
lions entering any Level A harassment zone.
    Harbor seals--Up to 52 individual seals have been photographed 
simultaneously hauled out on the nearby dock at Fishermen's Bend 
(Ridgway unpubl. data). Direct effects of construction noise in this 
area will be partially blocked by the recently constructed Phase II 
boat launch and parking area. We assume that the majority of animals 
that haul out on the nearby floats at Fishermen's Bend are likely to go 
under water and resurface throughout the duration of the project. The 
action area also extends into Stephens Passage near the location of a 
known harbor seal haulout near Horse Island. Abundance estimates within 
this area are 276.5 harbor seals (NOAA 2018). However, only a small 
portion of this survey unit is located within the project area and thus 
it is estimated that 25 percent (70 harbor seals) may also be located 
within the action area each day. With both areas combined it is 
estimated up to 121 harbor seals (52 + 70) may be exposed to elevated 
sound levels during each day of drilling, resulting in a total of 2,806 
harbor seal takes by Level B harassment during the activity.
    Due to the number of harbor seals commonly within the Level A 
harassment zones for impact pile driving and drilling, there is a 
chance the injury zone will not be free of harbor seals for sufficient 
time to allow for impact driving as harbor seals frequently use the 
nearby habitat. It is assumed that no more than 11 seals are likely to 
be found within the inner harbor, which will be used as the maximum of 
harbor seals that may be taken by Level A harassment for each day of 
the project. This results in a total estimate of 253 Level A harassment 
takes of harbor seals.
    Dall's porpoise--Dall's porpoises have been observed to have strong 
seasonal patterns with the highest number being observed in the spring 
and the fewest in the fall (Dahlheim et al., 2009). Group size in 
Alaska typically ranging from 10 to 20 individuals (Wells 2008). Should 
Dall's porpoise be present within the project area it is most likely to 
be during the spring months based on the strong seasonal patterns 
observed. The project is located in habitat that is not typical for 
Dall's porpoise, however they may still be present during the spring 
months of March, April and May. It is assumed that a large pod of 20 
Dall's porpoises (Wells 2008) may enter the harassment zones once each 
of these months, resulting in a take estimate of 60 Level B harassment 
takes of Dall's porpoise.
    Dall's porpoises can generally be observed by monitors due to the 
``rooster tail'' splash often made when surfacing (Wells 2008). 
However, due to the size of the Level A harassment zone associated with 
drilling (120 meters) and impact driving (220 meters), and due to the 
possibility for night work, it is possible Dall's porpoises may enter 
and remain in the Level A harassment zone undetected. It is 
conservatively assumed that one pair of Dall's porpoises may enter the 
Level A harassment zone and remain undetected every fourth day of pile 
driving, resulting in a take estimate of 12 Level A takes of Dall's 
porpoise across during the activity.
    Harbor porpoise--There is little data regarding harbor porpoise 
presence in the project area, however they have been observed in the 
project vicinity during several surveys of nearby waterways including 
Lynn Canal and Stephens Passage (Dahlheim et al., 2009; Dahlheim et 
al., 2015). The

[[Page 55934]]

average group size ranged from 1.24 to 1.57 throughout the study years, 
consistent with our estimate that one pair per day may be present in 
the Auke Bay Area. Based on the available information is estimated that 
up to one pair of harbor porpoises may be taken by Level B harassment 
during each of the 23 days of pile driving, resulting in a total 
estimated 46 takes by Level B harassment.
    Harbor porpoises are stealthy, having no visible blow and a low 
profile in the water making the species difficult for monitors to 
detect (Dahlheim et al., 2015). The Level A harassment zones extend up 
to 220 meters, because of this distance it is possible harbor porpoises 
may enter the Level A harassment zone undetected. It is conservatively 
assumed that one pair of harbor porpoises may enter the Level A 
harassment zone every other day of pile driving, resulting in a total 
estimated take of 24 harbor porpoises by Level A harassment.
    Killer whale--From 2010-2017 an average of 25 killer whale 
sightings were recorded in the project area per year (Ridgeway unpubl. 
data 2017). Data did not make distinctions between the stocks and thus 
the ratio between stocks is unknown. However, a resident pod identified 
as the AG pod is known to frequent the Juneau area (Dahlheim et al., 
2009; personal observation) and has 41 members recorded in the North 
Gulf Oceanic Society's Identification Guide (NGOS 2019). This pod is 
seen in the area intermittently in groups of up to approximately 25 
individuals (personal observation), consistent with the data for the 
area. Transient killer whales have been observed in nearby waterways as 
well and one group of 14 individuals were observed during surveys 
(Dahlheim et al., 2009). Killer whales move fast and have large ranges, 
and while they may occasionally enter the Level B harassment zones they 
are unlikely to linger in the area. Based on the information available 
it is conservatively estimated that one pod of residents (41 
individuals) and one pod of transients (14 individuals) may be taken 
during the duration of the project. As killer whales may not be able to 
be readily distinguished between resident and transients, or the 
applicable stock populations, a total of 55 takes of killer whales are 
requested. Based on the intermittent occurrence of killer whales from 
various stocks, if killer whales appear in Auke Bay during construction 
activities, it would be difficult to estimate what proportion of 
observed killer whales would be from each potential stock. Therefore, 
for the purposes of this analysis, we assume the total amount of 
estimated take of killer whales could be entirely from each of the 
three stocks in the area and have made our findings assuming the total 
amount of authorized take could be entirely from each of the three 
stocks. No Level A takes are requested for killer whales due to the 
small size of the Level A harassment zones and the conspicuous nature 
of killer whales that should allow for effective implementation of 
shutdowns before killer whales could incur PTS.
    Minke whale--There are no known occurrences of minke whales within 
the action area, however since their ranges extend into the project 
area and they have been observed in southeast Alaska (Dahlheim et al., 
2009) it is possible the species could occur near the project area 
given the large harassment zones associated with drilling. Therefore, 
one take is being requested per month of the potential project window 
(October 2020 through May 2021) for a total of 8 estimated takes of 
minke whale by Level B harassment. Due to the unlikely occurrence of 
minke whales in the general area and the additional unlikely of a minke 
whale occurring within 200 meters of the construction activity, no 
Level A takes of minke whales is proposed.
    California sea lion--California sea lions are not typically found 
in the project area, however one hauled out on Statter Harbor boat 
launch ramp float in September of 2017. For take purposes it is 
estimated that one California sea lion may be present each day of in-
water work, resulting in a total of 23 estimated takes by Level B 
harassment. Due to the rarity of California sea lions in the area, no 
Level A harassment take is proposed.
    The total number of takes proposed to be authorized are summarized 
in Table 7 below.

                   Table 7--Takes Proposed to be Authorized by Level A and Level B Harassment
----------------------------------------------------------------------------------------------------------------
                                                             Total proposed    Total proposed
                                                                 Level B           Level A         Total takes
                                                               harassment        harassment      proposed to  be
                                                                  takes             takes          authorized
----------------------------------------------------------------------------------------------------------------
Humpback whale............................................                92                 0                92
Steller sea lion eDPS.....................................             2,282                 0             2,282
Steller sea lion wDPS.....................................               501                 0               501
Harbor seal...............................................             2,806               253             3,059
Dall's porpoise...........................................                60                12                72
Harbor porpoise...........................................                46                24                70
Killer whale, Northern Resident, Gulf of Alaska Transient,                55                 0                55
 West Coast Transient.....................................
Minke whale...............................................                 8                 0                 8
California sea lion.......................................                23                 0                23
----------------------------------------------------------------------------------------------------------------

Proposed Mitigation

    In order to issue an IHA under Section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity, and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of such species or stock for taking for certain 
subsistence uses (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 such 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or

[[Page 55935]]

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.
    In addition to the measures described later in this section, the 
City of Juneau will employ the following standard mitigation measures:
     Conduct briefings between construction supervisors and 
crews and the marine mammal monitoring team prior to the start of all 
pile driving activity, and when new personnel join the work, to explain 
responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures;
     For in-water heavy machinery work other than pile driving 
(e.g., standard barges, etc.), if a marine mammal comes within 10 m, 
operations shall cease and vessels shall reduce speed to the minimum 
level required to maintain steerage and safe working conditions;
     Work may not begin during nighttime hours, or during 
periods of low visibility when visual monitoring of marine mammals can 
be conducted. However, work can continue into the nighttime hours if 
necessary;
     For those marine mammals for which Level B harassment has 
not been authorized, in-water pile installation/removal and drilling 
will shut down immediately if such species are observed within or on a 
path towards the monitoring zone (i.e., Level B harassment zone); and
     If take reaches the authorized limit for an authorized 
species, pile installation will be stopped as these species approach 
the Level B harassment zone to avoid additional take.
    The following measures will apply to the City of Juneau's 
mitigation requirements:
    Establishment of Shutdown Zone for Level A Harassment--For all pile 
driving/removal and drilling activities, the City of Juneau will 
establish a shutdown zone, as described in Table 8 below. The purpose 
of a shutdown zone is generally to define an area within which shutdown 
of activity will occur upon sighting of a marine mammal (or in 
anticipation of an animal entering the defined area). The placement of 
Protected Species Observers (PSOs) during all pile driving and drilling 
activities (described in detail in the Proposed Monitoring and 
Reporting Section) will ensure marine mammals in the shutdown zones are 
visible.

                                            Table 8--Monitoring and Shutdown Zones for Each Project Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                        Shutdown zones  (m)                                 Monitoring
                                                         --------------------------------------------------------------------------------   zones  (m)
                         Source                                                                High                                      ---------------
                                                          Low  frequency  Mid- frequency     frequency        Phocid          Otariid
                                                              cetacean        cetacean       ceteacean                                      All species
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Removal.......................................              20              10              25              10              10           2,500
Vibratory Installation/Drilling.........................              80              10             120              50              10           2,500
Impact Driving..........................................             185              10             220             100              10           1,000
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Establishment of Monitoring Zones for Level B Harassment--The City 
of Juneau will establish monitoring zones to correlate when possible 
with Level B harassment zones which are areas where SPLs are equal to 
or exceed the 160 dB rms threshold for impact driving and the 120 dB 
rms threshold during vibratory driving and drilling. Monitoring zones 
provide utility for observing by establishing monitoring protocols for 
areas adjacent to the shutdown zones. Monitoring zones enable observers 
to be aware of and communicate the presence of marine mammals in the 
project area outside the shutdown zone and thus prepare for a potential 
cease of activity should the animal enter the shutdown zone. The 
monitoring zones are described in Table 8 above. If visibility is such 
that observers are able to make observations beyond the monitoring zone 
distance, these observations will be recorded and reported. The Level B 
harassment zone for vibratory pile installation and down the hole 
drilling is so large that a smaller and more feasible zone will be 
implemented as monitoring zones. Should PSOs determine the monitoring 
zone cannot be effectively observed in its entirety, Level B harassment 
exposures will be recorded and extrapolated based upon the number of 
observed take and the percentage of the Level B harassment zone that 
was not visible.
    Soft Start--The use of soft-start procedures are believed to 
provide additional protection to marine mammals by providing warning 
and/or giving marine mammals a chance to leave the area prior to the 
hammer operating at full capacity. For impact pile driving, contractors 
will be required to provide an initial set of strikes from the hammer 
at reduced energy, with each strike followed by a 30-second waiting 
period. This procedure will be conducted a total of three times before 
impact pile driving begins. Soft start will be implemented at the start 
of each day's impact pile driving and at any time following cessation 
of impact pile driving for a period of thirty minutes or longer. Soft 
start is not required during vibratory pile driving and removal 
activities.
    Pre-Activity Monitoring--Prior to the start of daily in-water 
construction activity, or whenever a break in pile driving/removal or 
drilling of 30 minutes or longer occurs, PSOs will observe the shutdown 
and monitoring zones for a period of 30 minutes. The shutdown zone will 
be cleared when a marine mammal has not been observed within the zone 
for that 30-minute period. If a marine mammal is observed within the 
shutdown zone, a soft-start cannot proceed until the animal has left 
the zone or has not been observed for 15 minutes. If the monitoring 
zone has been observed for 30 minutes and non-permitted species are not 
present within the zone, soft start procedures can commence and work 
can continue even if visibility becomes impaired within the monitoring 
zone. When a marine mammal permitted for Level B harassment take is 
present in the monitoring zone, activities may begin and Level B 
harassment take will be recorded. If work ceases for more than

[[Page 55936]]

30 minutes, the pre-activity monitoring of both the monitoring zone and 
shutdown zone will commence.
    Due to the depth of the water column and strong currents present at 
the project site, bubble curtains will not be implemented as they would 
not be effective in this environment.
    Based on our evaluation of the applicant's proposed measures, NMFS 
has preliminarily determined that the proposed mitigation measures 
provide the means effecting the least practicable impact on the 
affected species or stocks and their habitat, paying particular 
attention to rookeries, mating grounds, and areas of similar 
significance.

Proposed 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 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density).
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas).
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors.
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks.
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat).
     Mitigation and monitoring effectiveness.
Marine Mammal Visual Monitoring
    Monitoring shall be conducted by NMFS-approved PSOs per the Marine 
Mammal Monitoring Plan provided in Appendix B of the City of Juneau's 
application. Trained observers shall be placed from the best vantage 
points practicable to monitor for marine mammals and implement shutdown 
or delay procedures when applicable through communication with the 
equipment operator. Observer training must be provided prior to project 
start, and shall include instruction on species identification 
(sufficient to distinguish the species in the project area), 
description and categorization of observed behaviors and interpretation 
of behaviors that may be construed as being reactions to the specified 
activity, proper completion of data forms, and other basic components 
of biological monitoring, including tracking of observed animals or 
groups of animals such that repeat sound exposures may be attributed to 
individuals (to the extent possible).
    Monitoring will be conducted 30 minutes before, during, and 30 
minutes after pile driving/removal and drilling activities. In 
addition, observers shall record all incidents of marine mammal 
occurrence, regardless of distance from activity, and shall document 
any behavioral reactions in concert with distance from piles being 
driven or removed. Pile driving/removal and drilling activities include 
the time to install or remove a single pile or series of piles, as long 
as the time elapsed between uses of the pile driving equipment is no 
more than 30 minutes.
    A minimum of two PSOs will be based strategically with one PSO on 
land at the Statter Harbor project site and the other on land or 
potentially on a vessel partway into Auke Bay. These stations will 
allow full monitoring of the impact hammer monitoring zone and the 
Level A shutdown zones. Potential locations for the second observer are 
described on pages 5 and 6 in Appendix B of the City of Juneau's 
application.
    PSOs will scan the waters using binoculars, and/or spotting scopes, 
and will use a handheld GPS or range-finder device to verify the 
distance to each sighting from the project site. All PSOs will be 
trained in marine mammal identification and behaviors and are required 
to have no other project-related tasks while conducting monitoring. In 
addition, monitoring will be conducted by qualified observers, who will 
be placed at the best vantage point(s) practicable to monitor for 
marine mammals and implement shutdown/delay procedures when applicable 
by calling for the shutdown to the hammer operator. The City of Juneau 
will adhere to the following observer qualifications:
    (i) Independent observers (i.e., not construction personnel) are 
required;
    (ii) At least one observer must have prior experience working as an 
observer;
    (iii) Other observers may substitute education (degree in 
biological science or related field) or training for experience; and
    (iv) The City of Juneau shall submit observer CVs for approval by 
NMFS.
    Additional standard observer qualifications include:
     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 and times when in-water construction 
activities were suspended to avoid potential incidental injury from 
construction sound of marine mammals observed within a defined shutdown 
zone; 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.
    The City of Juneau will submit a marine mammal monitoring report. A 
draft marine mammal monitoring report will be submitted to NMFS within 
90 days after the completion of pile driving and removal and drilling 
activities. It will include an overall description of work completed, a 
narrative regarding marine mammal sightings, and associated PSO data 
sheets. Specifically, the report must include:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;

[[Page 55937]]

     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Locations of all marine mammal observations; and
     Other human activity in the area.
    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.
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA 
(if issued), such as an injury, serious injury or mortality, the City 
of Juneau will immediately cease the specified activities and report 
the incident to the Chief of the Permits and Conservation Division, 
Office of Protected Resources, NMFS, and the Alaska Regional Stranding 
Coordinator. The report will include the following information:
     Description of the incident;
     Environmental conditions (e.g., Beaufort sea state, 
visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities may not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with the City of 
Juneau to determine what is necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. The City of Juneau 
will not be able to resume their activities until notified by NMFS via 
letter, email, or telephone.
    In the event that the City of Juneau discovers an injured or dead 
marine mammal, and the lead PSO determines that the cause of the injury 
or death is unknown and the death is relatively recent (e.g., in less 
than a moderate state of decomposition as described in the next 
paragraph), City of Juneau will immediately report the incident to the 
Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, and the NMFS Alaska Stranding Hotline and/or by email 
to the Alaska Regional Stranding Coordinator. The report will include 
the same information identified in the paragraph above. Activities will 
be able to continue while NMFS reviews the circumstances of the 
incident. NMFS will work with City of Juneau to determine whether 
modifications in the activities are appropriate.
    In the event that City of Juneau discovers an injured or dead 
marine mammal and the lead PSO determines that the injury or death is 
not associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), City of Juneau will report the 
incident to the Chief of the Permits and Conservation Division, Office 
of Protected Resources, NMFS, and the NMFS Alaska Stranding Hotline 
and/or by email to the Alaska Regional Stranding Coordinator, within 24 
hours of the discovery. City of Juneau will provide photographs, video 
footage (if available), or other documentation of the stranded animal 
sighting to NMFS and the Marine Mammal Stranding Network.

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).
    Pile driving/removal and drilling activities associated with the 
Statter Harbor construction project as outlined previously, have the 
potential to disturb or displace marine mammals in Auke Bay. 
Specifically, the specified activities may result in take, in the form 
of Level A harassment and Level B harassment from underwater sounds 
generated from pile driving and removal and down-the-hole drilling. 
Potential takes could occur if individuals of these species are present 
in the ensonified zone when these activities are underway.
    The takes from Level A and Level B harassment will be due to 
potential behavioral disturbance, TTS, and PTS (for select species). No 
mortality is anticipated given the nature of the activity and measures 
designed to minimize the possibility of injury to marine mammals. Level 
A harassment is only anticipated for Dall's porpoise, harbor porpoise, 
and harbor seal. The potential for harassment is minimized through the 
construction method and the implementation of the planned mitigation 
measures (see Mitigation section).
    As described previously, killer whales, minke whales, and 
California sea lions are considered rare in the project area and we 
authorize only nominal and precautionary take of these species. 
Therefore, we do not expect meaningful impacts to these species and 
find that the total killer whale, minke whale, and California sea lion 
take from each of the specified activities will have a negligible 
impact on this species.
    For remaining species, we discuss the likely effects of the 
specified activities in greater detail. Effects on individuals that are 
taken by Level B harassment, on the basis of reports in the literature 
as well as monitoring from other similar activities, will likely be 
limited to reactions such as increased swimming speeds, increased 
surfacing time, or decreased foraging (if such activity were occurring) 
(e.g., Thorson and Reyff 2006; Lerma 2014; ABR 2016). Most likely, 
individuals will move away from the sound source and be temporarily 
displaced from the areas of pile driving and drilling, although even 
this reaction has been observed primarily only in association with 
impact pile driving. The pile driving activities analyzed here are 
similar to, or less impactful than, numerous other construction 
activities conducted in southeast Alaska, which

[[Page 55938]]

have taken place with no known long-term adverse consequences from 
behavioral harassment. Level B harassment will be reduced to the level 
of least practicable adverse impact through use of mitigation measures 
described herein and, if sound produced by project activities is 
sufficiently disturbing, animals are likely to avoid the area while the 
activity is occurring. While vibratory driving and drilling associated 
with the planned project may produce sound at distances of many 
kilometers from the project site, thus intruding on some habitat, the 
project site itself is located in a busy harbor and the majority of 
sound fields produced by the specified activities are close to the 
harbor. Therefore, we expect that animals annoyed by project sound 
would avoid the area and use more-preferred habitats.
    In addition to the expected effects resulting from authorized Level 
B harassment, we anticipate that harbor porpoises, Dall's porpoises, 
and harbor seals may sustain some limited Level A harassment in the 
form of auditory injury. However, animals in these locations that 
experience PTS would likely only receive slight PTS, i.e., minor 
degradation of hearing capabilities within regions of hearing that 
align most completely with the energy produced by pile driving. If 
hearing impairment occurs, it is most likely that the affected animal 
would lose only a small number of decibels in its hearing sensitivity, 
which in most cases is not likely to meaningfully affect its ability to 
forage and communicate with conspecifics. As described above, we expect 
that marine mammals would be likely to move away from a sound source 
that represents an aversive stimulus, especially at levels that would 
be expected to result in PTS, given sufficient notice through use of 
soft start.
    The project also is not expected to have significant adverse 
effects on affected marine mammals' habitat. The project activities 
will not modify existing marine mammal habitat for a significant amount 
of time. The activities may cause some fish to leave the area of 
disturbance, thus temporarily impacting marine mammals' foraging 
opportunities in a limited portion of the foraging range; but, because 
of the short duration of the activities and 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.
    In summary and as described above, the following factors primarily 
support our preliminary 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 is anticipated or authorized;
     The 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 are likely 
to consist of temporary modifications in behavior that are not 
anticipated to result in fitness impacts to individuals;
     The specified activity and ensonification area is very 
small relative to the overall habitat ranges of all species; and
     The presumed efficacy of the mitigation measures in 
reducing the effects of the specified activity to the level of least 
practicable adverse impact.
    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 proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from the proposed 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. Additionally, other qualitative 
factors may be considered in the analysis, such as the temporal or 
spatial scale of the activities.
    Table 7 demonstrates the number of animals that could be exposed to 
received noise levels that could cause Level A harassment and Level B 
harassment for the planned activities in the Statter Harbor project 
area. Our analysis shows that less than one third of the population 
abundance of each affected stock could be taken by harassment. The 
numbers of animals anticipated to be taken for these stocks would be 
considered small relative to the relevant stock's abundances even if 
each estimated taking occurred to a new individual--an extremely 
unlikely scenario.
    Calculated takes do not assume multiple harassments of the same 
individual(s), resulting in larger estimates of take as a percentage of 
stock abundance than are likely given resident individuals. This is the 
case with the resident harbor seals (Lynn Canal/Stephens Passage stock) 
as it is documented that the same small group of individuals frequent 
the Statter Harbor area.
    As reported, a small number of harbor seals, most of which reside 
in Statter Harbor year-round, will be exposed to construction 
activities for 23 days. The total population estimate in the Lynn 
Canal/Stephens Passage stock is 9,478 animals over 1.37 million acres 
(5,500 km\2\) of area in their range. The great majority of these 
exposures will be to the same animals given their residency patterns, 
however the number of repeat exposures is difficult to quantify due to 
the lack of visible markings on harbor seals in water. No more than 121 
harbor seals have ever been sighted in the project area and the harbor 
seals are known to be resident. Therefore, it is unlikely that the 
harbor seals entering the area on each of the 23 days of construction 
activity are unique individuals and are rather repeated takes of the 
same small number of individuals.
    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals will be taken relative to the population size 
of the affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    In order to issue an IHA, NMFS must find that the specified 
activity will not have an ``unmitigable adverse impact'' on the 
subsistence uses of the affected marine mammal species or stocks by 
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50 
CFR 216.103 as an impact resulting from the specified activity: (1) 
That is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by: (i) Causing 
the marine mammals to abandon or avoid hunting areas; (ii) Directly 
displacing subsistence users; or (iii) Placing physical barriers 
between the marine mammals and the subsistence hunters; and (2) That 
cannot be sufficiently mitigated by other measures to increase the 
availability of marine mammals to allow subsistence needs to be met.

[[Page 55939]]

    The proposed project is not known to occur in an important 
subsistence hunting area. Auke Bay is a developed area with regular 
marine vessel traffic. Of the marine mammals considered in this IHA 
application, only harbor seals are known to be used for subsistence in 
the project area. In a previous consultation with ADF&G, the Douglas 
Indian Association, Sealaska Heritage Institute, and the Central 
Council of the Tlingit and Haida Indian Tribes of Alaska on other 
construction activities in Statter Harbor, representatives indicated 
that the primary concern with construction activities in Statter Harbor 
was impacts to herring fisheries, not marine mammals. As stated above, 
impacts to fish from the proposed project are expected to be localized 
and temporary, so are not likely to impact herring fisheries. If any 
tribes express concerns regarding project impacts to subsistence 
hunting of marine mammals, further communication between will take 
place, including provision of any project information, and 
clarification of any mitigation and minimization measures that may 
reduce potential impacts to marine mammals. Therefore, NMFS has 
preliminarily determined that the total taking of affected species or 
stocks would not have an unmitigable adverse impact on the availability 
of such species or stocks for taking for subsistence purposes.

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally, in this case with the Alaska Region Office of 
Protected Resources, whenever we propose to authorize take for 
endangered or threatened species.
    The effects of this proposed Federal action were adequately 
analyzed in NMFS' 2019 Biological Opinion on the City and Borough of 
Juneau Docks and Harbors Department Statter Harbor Improvements 
Project, Juneau, Alaska, which concluded that the take NMFS proposes to 
authorize through this IHA would not jeopardize the continued existence 
of any endangered or threatened species or destroy or adversely modify 
any designated critical habitat.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to the City of Juneau for conducting pile driving and 
removal activities in Auke Bay between October 2020 and May 2021, 
provided the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated. A draft of the proposed IHA can be found 
at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this Notice of Proposed IHA for the proposed 
construction activity. We also request at this time comment on the 
potential renewal of this proposed IHA as described in the paragraph 
below. Please include with your comments any supporting data or 
literature citations to help inform decisions on the request for this 
IHA or a subsequent Renewal.
    On a case-by-case basis, NMFS may issue a one-year IHA renewal with 
an additional 15 days for public comments when (1) another year of 
identical or nearly identical activities as described in the Specified 
Activities section of this notice is planned or (2) the activities as 
described in the Specified Activities section of this notice would not 
be completed by the time the IHA expires and a Renewal would allow for 
completion of the activities beyond that described in the Dates and 
Duration section of this notice, provided all of the following 
conditions are met:
     A request for renewal is received no later than 60 days 
prior to expiration of the current IHA.
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
requested Renewal are identical to the activities analyzed under the 
initial IHA, are a subset of the activities, or include changes so 
minor (e.g., reduction in pile size) that the changes do not affect the 
previous analyses, mitigation and monitoring requirements, or take 
estimates (with the exception of reducing the type or amount of take 
because only a subset of the initially analyzed activities remain to be 
completed under the Renewal).
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized.
     Upon review of the request for Renewal, the status of the 
affected species or stocks, and any other pertinent information, NMFS 
determines that there are no more than minor changes in the activities, 
the mitigation and monitoring measures will remain the same and 
appropriate, and the findings in the initial IHA remain valid.

    Dated: October 11, 2019.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2019-22730 Filed 10-17-19; 8:45 am]
 BILLING CODE 3510-22-P