[Federal Register Volume 83, Number 241 (Monday, December 17, 2018)]
[Notices]
[Pages 64541-64563]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-27258]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XG628


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Railroad Dock Dolphin 
Installation Project, Skagway, Alaska

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 White Pass & Yukon Route 
(WP&YR) for authorization to take marine mammals incidental to the 
Railroad Dock dolphin installation project in Skagway, 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 January 
16, 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/national/marine-mammal-protection/incidental-take-authorizations-construction-activities 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: Wendy Piniak, 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/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. 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

[[Page 64542]]

geographical region if certain findings are made and either regulations 
are issued or, if the taking is limited to harassment, a notice of a 
proposed incidental take authorization may be provided to the public 
for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other means of effecting the least practicable adverse 
impact on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of 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 NDAA (Pub. L. 108-136) removed the ``small numbers'' and 
``specified geographical region'' limitations indicated above and 
amended the definition of ``harassment'' as it applies to a ``military 
readiness activity.'' 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 August 21, 2018, NMFS received a request from WP&YR for an IHA 
to take marine mammals incidental to the Railroad Dock dolphin 
installation project in Skagway, Alaska. WP&YR submitted a revised 
version of the application on November 9, 2018 which was deemed 
adequate and complete on November 15, 2018. WP&YR's request is for take 
of seven species of marine mammals by Level B harassment and Level A 
harassment incidental to impact pile driving, vibratory pile driving 
and removal, and down-the-hole drilling activities. Neither WP&YR nor 
NMFS expects serious injury or mortality to result from this activity 
and, therefore, an IHA is appropriate. In-water activities (pile 
installation and extraction) associated with the project are scheduled 
to begin February 1, 2019, and be completed April 30, 2019.

Description of Proposed Activity

Overview

    WP&YR requested the authorization of take of small numbers of 
marine mammals incidental to pile driving/removal and down-the-hole 
drilling associated with the installation of two new 200-ton pile 
supported mooring dolphins in Skagway Harbor, Alaska. The purpose of 
the project is to provide ample safe moorage when both Norwegian 
Breakaway and Royal Caribbean Quantum class cruise ship vessels are in 
port. The existing dolphin infrastructure does not allow for both 
cruise ships to be moored at the dock at the same time. The additional 
dolphins would allow for both ships to be docked simultaneously. To 
facilitate dual mooring, the proposed project includes the installation 
of two 200-ton dolphins, each comprised of six 42-inch steel permanent 
piles 300 feet in length. WP&YR would also install and subsequently 
remove 14 36-inch template (temporary) piles (200 feet in length) at 
the two dolphin locations which are approximately 100 feet and 200 
feet, respectively, south of the existing southernmost mooring dolphin 
at the WP&YR Railroad Dock. The template and permanent piles are 
comprised of two to three 100-feet long segments which would be spliced 
(i.e., welded) together as they are installed. All temporary and 
permanent piles would require a combination of three pile installation 
methods: Vibratory driving, impact driving, and down-the-hole drilling. 
Sounds produced by these activities may result in take, by Level A and 
Level B harassment, of marine mammals located in Taiya Inlet, Alaska.

Dates and Duration

    In-water activities (pile installation and extraction) associated 
with the project are scheduled to begin February 1, 2019, and be 
completed April 30, 2019. Pile installation and removal would occur for 
89 days over the course of the three months. WP&YR anticipates up to 10 
hours of activity (vibratory driving, impact driving, and down-the-hole 
drilling) during daylight hours would occur per day.

Specific Geographic Region

    The activities would occur at the south end of WP&YR's Railroad 
Dock located in Skagway Harbor, Alaska. Skagway Harbor is located at 
the southwestern end of the 2.5-mile (mi)-long Skagway River valley. 
Three anadromous rivers are located near the project site including 
Skagway River, Taiya River, and Pullen Creek. The Skagway and Taiya 
Rivers empty into Taiya Inlet at the head of Lynn Canal west and 
northwest of the project site respectively. Pullen Creek empties into 
the Taiya Inlet on the southeast side of the valley northeast of the 
project site. Taiya Inlet/Lynn Canal is the northernmost fjord on the 
Inside Passage of the south coast of Alaska. The project site is 
located south of ADL 108521 and seaward of upland Lot 8, U.S. Survey 
5110; Latitude 59.44[deg] North (N), Longitude 135.33[deg] West (W) 
(see Figures 1-3 of WP&YR's application). Limited information is 
available on the benthic habitat beneath the Railroad Dock, however the 
basin is composed of glacial till sediments, consisting of mud, silty 
gravel, cobbles and boulders. The shoreline along Railroad dock is 
armored with riprap and contains little to no riparian vegetation. This 
armoring extends to below the mean higher high water (MHHW) mark to an 
unknown depth. At the project site, the Taiya Inlet is approximately 2 
kilometers (km) wide and water depth ranges from approximately 100-200 
feet (ft) (30-60 meters (m)); however water depth in Taiya Inlet 
reaches over 500 ft (152 m), within and south of the project area.
    Skagway Harbor is frequently visited by cruise ship vessels during 
the summer and is a site of recreational and commercial activity. 
Vessels must travel up Taiya Inlet to enter the Skagway Harbor.

Detailed Description of Specific Activity

    To facilitate dual mooring of large cruise ship vessels, the 
proposed Railroad Dock dolphin installation

[[Page 64543]]

project includes installation of two 200-ton dolphins. Two crane 
barges, one material barge, and three work boats (each under 25 feet) 
would be used to complete the project. Barges would be moored on-site 
for the duration of construction. Each dolphin would require the 
installation and removal of seven 36-inch steel pipe template piles (14 
total) and the installation six 42-inch steel pipe permanent piles (12 
total). The temporary template piles would be installed to aid in 
construction and would be removed after the permanent dolphin piles are 
installed. Each temporary template pile would be approximately 200 ft 
in length and would consist of up to two sections that would be spliced 
(e.g. welded) together as they are installed (for a total of up to 28 
segments). Each permanent pile would be approximately 300 ft in length 
and would consist of up to three sections that would be spliced 
together as they installed (for a total of 36 segments).
    Template and permanent piles would be installed in water depths up 
to 140-feet deep and into loose substrate that is intermixed with 
cobbles and boulder-sized rocks. Due to the nature of deep-water pile 
installation in loose sediment, each pile (consisting of two to three 
segments) would be installed using a combination of installation 
methods: Vibratory hammer, impact hammer, and drilling (Table 1). 
Removal of template piles would only require the use of a vibratory 
hammer. It may be necessary to switch between installation methods 
multiple times per day depending on encountered conditions. However, no 
activities would occur simultaneously (e.g., only one installation 
method would occur on one pile at any time). Throughout the project, 
one crane would be dedicated to drilling only and the second crane 
would alternate between the vibratory and impact hammers (as noted, 
only one crane would be active at any given time). In addition to 
alternating between installation methods, the project would require the 
piles segments to be spliced together to make the piles longer before 
continuing installation. That is, the first segment of pile would be 
installed using one or more methods; the second segment would then be 
welded to the first segment and the process would be repeated until the 
entire pile is installed.

            Table 1--Pile Installation and Removal Equipment
------------------------------------------------------------------------
 Pile installation equipment       Model/size        Description/purpose
------------------------------------------------------------------------
Crane.......................  200-250-ton barge     Install piles, set
                               with a 200-250-ft     dolphin caps, set
                               boom (up to 2         catwalks, move
                               cranes).              material, etc.
Vibratory Hammer............  APE 200 or            Advance pile through
                               equivalent.           overburden to
                                                     vibratory refusal.
Impact Hammer...............  Delmag D100 Diesel    Advance pile through
                               hammer or             overburden once
                               equivalent.           vibratory refusal
                                                     has been reached.
Drill.......................  Rock Anchor (8-inch   A drill is inserted
                               hole): ICE-HS-27      through the pile
                               Top drive down-hole   all the way down to
                               hammer PDQL-80 or     bedrock. The drill
                               equivalent.           breaks up rock into
                              Socket (42-inch        small flakes
                               hole): PPV ring bit   (tailings) which
                               MF34 down hole        are removed from
                               hammer or             the drilled hole as
                               equivalent.           the pile or casing
                                                     advances.
------------------------------------------------------------------------

    The tips of all template piles would be embedded approximately 60 
ft beneath the mudline using impact or vibratory hammering and 
drilling. The structural design of the dolphins requires the tips of 
all permanent piles to bear on and be socketed in bedrock located 100-
200 ft beneath the mudline. During installation, some or all piles will 
encounter obstructions prior to reaching final tip depth and will 
require drilling through obstructions to meet project specifications. 
The first segment of each pile would be impact or vibratory driven to 
first refusal. First refusal occurs when the pile tip cannot be 
advanced any further with a vibratory or impact hammer. This will most 
likely occur when the pile tip is located on an obstruction (prior to 
reaching bedrock) or at bedrock. To determine whether the pile tip has 
reached bedrock, the contractor would then drill past the segment tip. 
If the drill advances up to 20 ft past the segment tip through rock, 
bedrock is encountered. If the drill ``punches through'' the 
obstruction and encounters soft overburden material, the pile would 
continue to be advanced using drilling, impact, or vibratory methods. 
Once second refusal is reached, bedrock would again need to be verified 
by drilling up to 20-ft past the pile tip into bedrock. This process is 
repeated until bedrock is confirmed (permanent piles) or the required 
depth has been achieved (template piles), however it is possible that 
template piles may be fully installed without encountering bedrock.
    As each pile segment is installed, WP&YR would splice segments to 
increase the length of the pile and continue with the pile 
installation. Splicing pipe pile involves welding pipe pile end to end 
with a complete joint penetration weld. On average, splicing is 
anticipated to require three to five days to complete per pile. For 
permanent piles, once bedrock is confirmed and all segments are welded 
together, a smaller 8-inch drill would be used to drill a rock anchor 
hole into bedrock 50 ft past the pile tip. The 8-inch hole for the rock 
anchor is drilled beneath the pile tip from within the hollow pipe 
pile. A steel bar would be grouted into this hole. Once the grout sets, 
a jack would be applied to the top of the bar and the rock anchor would 
be locked off to plates at the top of the pile. After the permanent 
piles are installed, temporary piles would be removed.
    WP&YR estimates drilling and vibratory hammering would occur for a 
maximum of 10 hours per day (although the amount of time within that 10 
hour window dedicated to each method cannot be determined at this time 
as it is dependent upon substrate conditions) and total number of 
impact pile driving strikes would not exceed 2,000 per day. WP&YR 
estimates that it would take 8 hours to install and remove one template 
pile and 28.1 hours (over the course of multiple days) to install one 
permanent pile (additional details can be found in section 2 of WP&YR's 
application).
    After all dolphin piles are installed, a prefabricated steel 
dolphin cap would be set on top of the piles and welded to the cap. The 
project also involves modifications to an existing dolphin cap and 
installation of two catwalks; however, this work does not include in-
water work and is not anticipated to take marine mammals. All barges, 
cranes, equipment, personnel, temporary structures, unused materials, 
etc. would be removed from the site upon project completion.

[[Page 64544]]

    WP&YR anticipates all in-water construction would occur between 
February 1, 2019 and April 30, 2019 (89 days) with mobilization 
occurring December through January, 2019 and above water work and 
demobilization occurring April through May, 2019. Multiple or all 
installation methods of template and permanent piles may occur on the 
same day, but would not occur at the same time. Work may occur seven 
days per week.
    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

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS' Stock Assessment Reports (SAR; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS' 
website (https://www.fisheries.noaa.gov/find-species).
    Table 2 lists all species with expected potential for occurrence in 
the Taiya Inlet and larger Lynn Canal 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 (2017). 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' SARs). While no mortality is 
anticipated or authorized here, PBR and annual serious injury and 
mortality from anthropogenic sources are included here as gross 
indicators of the status of the species and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS' U.S. Alaska SARs (e.g., Muto et al. 2018). All values presented 
in Table 2 are the most recent available at the time of publication and 
are available in the 2017 SARs (Muto et al. 2018) and draft 2018 SARs 
(available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).

                              Table 2--Marine Mammals Potentially Present Within Taiya Inlet During the Specified Activity
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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 Eschrichtiidae:
    Gray whale......................  Eschrichtius robustus..  Eastern North Pacific..  -, -, N             26,960 (0.05, 25,849,         801        138
                                                                                                             2016).
Family Balaenidae:
    Humpback whale..................  Megaptera novaeangliae.  Central North Pacific..  -, -, Y             10,103 (0.3, 7,890,            83         25
                                                                                                             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 Physeteridae:
Sperm whale.........................  Physeter macrocephalus.  North Pacific..........  E, D, Y             N/A (N/A, N/A, 2015)..        UND        4.4
Family Delphinidae:
    Killer whale....................  Orcinus orca...........  Alaska Resident........  -, -, N             2,347 (N/A, 2,347,             24          1
                                                                                                             2012) \4\.
                                                               Northern Resident        -, -, N             261 (N/A, 261, 2011)         1.96          0
                                                                                                             \4\.
                                                               Gulf of Alaska,          -, -, N             587 (N/A, 587, 2012)         5.87          1
                                                                Aleutian Islands,                            \4\.
                                                                Bering Sea Transient
                                                               West Coast Transient     -, -, N             243 (N/A, 243, 2009)          2.4          0
                                                                                                             \4\.
    Pacific White-Sided Dolphin.....  Lagenorhynchus           North Pacific..........  -, -, N             26,880 (N/A, N/A,             UND          0
                                       obliquidens.                                                          1990).
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena......  Southeast Alaska.......  -, -, Y             975 (0.12-0.14, 897,          8.9         34
                                                                                                             2012) \5\.
    Dall's porpoise.................  Phocoenoides dalli.....  Alaska.................  -, -, N             83,400 (0.097, N/A,           UND         38
                                                                                                             1991).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
    Steller sea lion................  Eumetopias jubatus.....  Western U.S............  E, D, Y             54,267 (N/A, 54,267,          326        252
                                                                                                             2017).
                                      Eastern U.S              T, D, Y................  41,638 (N/A,        2498..................        108
                                                                                         41,638, 2015)
Family Phocidae (earless seals):

[[Page 64545]]

 
    Harbor seal.....................  Phoca vitulina           Lynn Canal/Stephens      -, -, N             9,478 (N/A, 8,605,            155         50
                                       richardii.               Passage.                                     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 (N/A).
\3\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
  fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated
  with estimated mortality due to commercial fisheries is presented in some cases.
\4\ N is based on counts of individual animals identified from photo-identification catalogs.
\5\ In the SAR for harbor porpoise, NMFS identified population estimates and PBR for porpoises within inland southeast Alaska waters (these abundance
  estimates have not been corrected for g(0); therefore, they are likely conservative).

    All species that could potentially occur in the proposed survey 
areas are included in Table 2. However, the temporal and/or spatial 
occurrence of the Pacific white-sided dolphin (Lagenorhynchus 
obliquidens), gray whale (Eschrichtius robustus), and sperm whale 
(Physeter macrocephalus) are such that take is not expected to occur, 
and they are not discussed further beyond the explanation provided 
here. The range of Pacific white-sided dolphin is suggested to overlap 
with Lynn Canal (Muto et al. 2018), but no sightings have been 
documented in the project area (Dahlheim et al. 2009; K. Gross, Never 
Monday Charters, personal communication; R. Ford, Taiya Inlet Watershed 
Council, personal communication reported in MOS 2016). Gray whale 
sightings in this northern portion of Southeast Alaska are very rare; 
there have only been eight sightings since 1997 (J. Neilson, National 
Park Service, personal communication reported in MOS 2016). None of 
these observations occurred in the Taiya Inlet/Lynn Canal. Tagged sperm 
whales have been tracked within the Gulf of Alaska, with one whale 
tracked up Lynn Canal during October 2014 (SEASWAP 2017). Tagging 
studies primarily show that sperm whales use the deep water slope 
habitat extensively for foraging (Mathias et al. 2012). This species 
prefers deeper waters, and are unlikely to occur in Taiya Inlet.
    WP&YR requested take for seven marine mammal species documented in 
the waters of the Taiya Inlet/Lynn Canal (Dahlheim et al. 2009; Muto et 
al. 2018). One of the species, the harbor seal, is known to regularly 
occur near the project site year round; however the closest seasonal 
haulout site is three miles (4.8 km) from the project area and not 
within the Level B harassment ensonified area (see Estimated Take). 
Moderate to high abundances of Steller sea lions are also known to 
seasonally occupy the inlet, with the closest seasonal haulout located 
11 miles (18 km) from the project site. Several humpback whales have 
been observed within Taiya Inlet, sometimes close to Skagway, during 
non-winter months. The remaining four species (harbor porpoise, Dall's 
porpoise, killer whale, and minke whale) may occur in Taiya Inlet/Lynn 
Canal, but less frequently and farther from Skagway Harbor and the 
project site. Information on presence and distribution in the WP&YR 
project area can be found in the

Habitat

    No Biologically Important Areas (BIAs) or ESA-designated critical 
habitat overlap with the project area, however there is seasonally 
important foraging habitat for some species of marine mammal which 
overlap spatially and temporally with proposed project activities. The 
annual eulachon run (which occurs for approximately three to four weeks 
during April through May) in Lynn Canal is important to all marine 
mammals (particularly Steller sea lions, and harbor seals, and humpback 
whales) for seasonal foraging and many species travel into Taiya Inlet 
to forage on this prey.

Cetaceans

Humpback Whale
    The humpback whale is distributed worldwide in all ocean basins. In 
winter, most humpback whales are found in the subtropical and tropical 
waters of the Northern and Southern Hemispheres, and then migrate to 
high latitudes in the summer to feed. The historic summer feeding range 
of humpback whales in the North Pacific encompassed coastal and inland 
waters around the Pacific Rim from Point Conception, California, north 
to the Gulf of Alaska and the Bering Sea, and west along the Aleutian 
Islands to the Kamchatka Peninsula and into the Sea of Okhotsk and 
north of the Bering Strait (Johnson and Wolman 1984).
    There are currently three MMPA-designated stocks of humpback whales 
in the North Pacific: (1) The California/Oregon/Washington stock, 
consisting of winter/spring populations in coastal Central America and 
coastal Mexico which migrate to the coast of California to southern 
British Columbia in summer/fall (Calambokidis et al. 1989; Steiger et 
al. 1991; Calambokidis et al. 1993); (2) the Central North Pacific 
stock, consisting of winter/spring populations of the Hawaiian Islands 
which migrate primarily to northern British Columbia/Southeast Alaska, 
the Gulf of Alaska, and the Bering Sea/Aleutian Islands (Perry et al. 
1990; Calambokidis et al. 1997); and (3) the Western North Pacific 
stock, consisting of winter/spring populations off Asia which migrate 
primarily to Russia and the Bering Sea/Aleutian Islands. The Central 
North Pacific stock is the only stock that is found near the project 
area.
    On September 8, 2016, NMFS published a final decision changing the 
status of humpback whales under the Endangered Species Act (ESA) (81 FR 
62259), effective October 11, 2016. Previously, humpback whales were 
listed under the ESA as an endangered species worldwide. In the 2016 
decision, NMFS recognized the existence of 14 distinct population 
segments (DPSs), classified four of those as endangered and one as 
threatened, and determined that the remaining nine DPSs do not warrant 
protection under the ESA. Whales occurring in the project area would 
primarily include individuals from the delisted Hawaii DPS (93.9 
percent probability), but could also include individuals from the 
threatened Mexico DPS (6.1 percent probability) (Wade et al. 2016).
    Humpback whales are found throughout southeast Alaska in a variety 
of marine environments, including

[[Page 64546]]

open-ocean, near-shore waters, and areas with strong tidal currents 
(Dahlheim et al. 2009). Humpback whales generally arrive in southeast 
Alaska in March and return to their wintering grounds in November. Some 
humpback whales depart late or arrive early to feeding grounds, and 
therefore the species occurs in southeast Alaska year-round (Straley 
1990). Dahlheim et al. (2009) observed humpback whales throughout all 
major waterways in southeast Alaska with concentrations of whales 
consistently observed in Icy Strait, Lynn Canal, Stephens Passage, 
Chatham Strait, and Frederick Sound. Mean group size varied among 
season with group sizes of 1.38, 1.65, and 1.95 in spring, summer, and 
fall respectively.
    Subsistence hunters in Alaska are not authorized to take Central 
North Pacific stock humpback whales and no takes were reported from 
2012-2016 (Muto et al. 2018). Threats to the Central North Pacific 
stock include changes in prey distribution due to climate change, 
entanglement in fishing gear, ship strike, and anthropogenic sound, 
however the Central North Pacific stock is increasing (Muto et al. 
2018).
Minke Whale
    Minke whales are found throughout the northern hemisphere in polar, 
temperate, and tropical waters. In the North Pacific, minke whales 
occur from the Bering and Chukchi seas south to near the Equator 
(Leatherwood et al. 1982). Minke whales are generally found in coastal 
waters shallower than 200 m and are usually observed solitary or in 
small groups of two to three whales (Zerbini et al. 2006; Zerbini et 
al. 2006). In Alaska, there is only one stock of minke whales and 
seasonal movements are associated with feeding areas that are generally 
located at the edge of the pack ice (NMFS 2014).
    Although no comprehensive abundance estimate is available for the 
Alaska stock of minke whales, recent surveys provide estimates for 
portions of the stock's range. A 2010 survey conducted on the eastern 
Bering Sea shelf produced a provisional abundance estimate of 2,020 (CV 
= 0.73) whales (Friday et al. 2013). This estimate is considered 
provisional because it has not been corrected for animals missed on the 
trackline, animals submerged when the ship passed, or responsive 
movement. Additionally, line-transect surveys were conducted in shelf 
and nearshore waters (within 30-45 nautical miles of land) in 2001-2003 
between the Kenai Peninsula (150[deg] W) and Amchitka Pass (178[deg] 
W). Minke whale abundance was estimated to be 1,233 (CV = 0.34) for 
this area (also not corrected for animals missed on the trackline) 
(Zerbini et al. 2006). The majority of the sightings were in the 
Aleutian Islands, rather than in the Gulf of Alaska, and in water 
shallower than 200 m. These estimates cannot be used as an estimate of 
the entire Alaska stock of minke whales because only a portion of the 
stock's range was surveyed.
    Surveys in southeast Alaska have consistently identified 
individuals throughout inland waters in low numbers, however none were 
observed in Taiya Inlet or Lynn Canal (Dahlheim et al. 2009). As few 
minke whales were observed during recent offshore Gulf of Alaska 
surveys for cetaceans in 2009, 2013, and 2015, a population estimate 
for minke whales in this area cannot be determined (Rone et al. 2017). 
There are no data available to determine trends in minke whale 
abundance in Alaska waters. Subsistence takes of minke whales in Alaska 
is rare, with the last known catch occurring in 1989. Although no 
incidents of human-related serious injury and mortality were recorded 
for Alaska stock minke whales between 2012 and 2016, threats to the 
population include entanglement in fishing gear, ship strikes, and 
anthropogenic sound, as well as changes in prey distribution due to 
climate change (Muto et al. 2018).
Killer Whale
    Killer whales have been observed in all oceans and seas of the 
world, but the highest densities occur in colder and more productive 
waters found at high latitudes. Killer whales are found throughout the 
North Pacific, and occur along the entire Alaska coast, in British 
Columbia and Washington inland waterways, and along the outer coasts of 
Washington, Oregon, and California (Muto et al. 2018). Based on data 
regarding association patterns, acoustics, movements, and genetic 
differences, eight killer whale stocks are now recognized in the 
Pacific Ocean: (1) The Alaska Resident stock; (2) the Northern Resident 
stock; (3) the Southern Resident stock; (4) the Gulf of Alaska, 
Aleutian Islands, and Bering Sea Transient stock; (5) the AT1 Transient 
stock; (6) the West Coast Transient stock; and (7) the Offshore stock, 
and (8) the Hawaii stock. Only the Alaska Resident, Northern Resident, 
Gulf of Alaska, Aleutian Islands, and Bering Sea Transient, and West 
Coast Transient stocks are considered in this analysis because other 
stocks occur outside the geographic area under consideration. Any of 
these four stocks could be seen in the action area; however, the Alaska 
and Northern Resident stocks are most likely to overlap with the 
project area (Muto et al. 2018).
    The Alaska Resident stock is found from southeastern Alaska to the 
Aleutian Islands and Bering Sea. Intermixing of Alaska Residents have 
been documented among the three areas, at least as far west as the 
eastern Aleutian Islands. The Northern Resident stock occurs from 
Washington State through part of southeastern Alaska. The Northern 
Resident stock is a transboundary stock, and includes killer whales 
that frequent British Columbia, Canada and southeastern Alaska 
(Dahlheim et al. 1997; Ford et al. 2000). The Gulf of Alaska, Aleutian 
Islands, and Bering Sea Transient stock occurs mainly from Prince 
William Sound through the Aleutian Islands and Bering Sea. The West 
Coast Transient stock includes animals that occur in California, 
Oregon, Washington, British Columbia and southeastern Alaska.
    Transient killer whales occur in smaller, less matrilineal 
groupings than resident killer whales. They are also more likely to 
rely on stealth tactics when foraging, making fewer and less 
conspicuous calls, and edging along shorelines and around headlands in 
order to hunt their prey, including, Steller sea lions, harbor seals, 
and smaller cetaceans, in highly coordinated attacks (Barrett-Lennard 
et al. 2011). Residents often travel in much larger and closer knit 
groups within which they share any fish they catch.
    Resident and transient killer whales have been documented in the 
middle to lower reaches of Lynn Canal, but not within the upper reaches 
or in Taiya Inlet (Dahlheim et al. 2009). Dahlheim et al. (2009) 
frequently observed two resident pods identified as AF and AG pods 
(Alaska Resident stock) throughout Icy Strait, Lynn Canal, Stephens 
Passage, Frederick Sound and upper Chatham Strait. The seasonality of 
resident killer whales could not be investigated statistically due to 
low encounter rates and mean group size of resident whales did not vary 
significantly among seasons and ranged from 19 to 33 individuals 
(Dahlheim et al. 2009).
    Dahlheim et al. (2009) observed transient killer whales in all 
major waterways, including Lynn Canal, in open-strait environments, 
near-shore waters, protected bays and inlets, and in ice-laden waters 
near tidewater glaciers. The transient killer whale mean group size 
also did not vary with season and ranged from four to six individuals 
in Southeast Alaska (Dahlheim et al. 2009). Transient killer whale 
numbers were highest in summer, with lower numbers observed in spring 
and fall.

[[Page 64547]]

    No reliable data on trends in population abundance for the entire 
Alaska Resident, Gulf of Alaska, Aleutian Islands, and Bering Sea 
Transient, and West Coast Transient stocks of killer whales are 
unavailable (Muto et al. 2018). The Northern Resident stock is 
increasing with an average 2.1 percent increase over a 36 year time 
period (Ellis et al. 2011). There are no reports of subsistence harvest 
of killer whales in Alaska, however other threats to the stocks include 
interactions with fisheries, vessel collisions, and decreases in prey 
abundance (Muto et al. 2018).
Harbor Porpoise
    The harbor porpoise inhabits temporal, subarctic, and arctic 
waters. In the eastern North Pacific, harbor porpoises range from Point 
Barrow, Alaska, to Point Conception, California. While harbor porpoise 
primarily frequent coastal waters and occur most frequently in waters 
less than 100 m deep (Hobbs and Waite 2010), they may occasionally be 
found in deeper offshore waters. Within the inland waters of Southeast 
Alaska, harbor porpoise distribution is clumped, with greatest 
densities observed in the Glacier Bay/Icy Strait region, and near 
Zarembo and Wrangell Islands and the adjacent waters of Sumner Strait 
(Allen and Angliss 2014). Group sizes were on average between 1.37-1.59 
animals (less than 2) (Dahlheim et al. 2009; 2015).
    In Alaska, harbor porpoises are currently divided into three 
stocks, based primarily on geography. These are (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 
(Allen and Angliss 2014). Only the Southeast Alaska stock is considered 
in this analysis because it is the only stock found in the project 
area.
    No reports of subsistence harvest of harbor porpoises from the 
Southeast Alaska stock have been reported since the early 1900s 
(Shelden et al. 2014).The total estimated annual level of human-caused 
mortality and serious injury for Southeast Alaska stock (n = 34) 
exceeds the calculated PBR of 8.9 porpoises. However because the 
calculated PBR is based on surveys from 2010-2012 in only a portion of 
the stock's range (the inside water of southeast Alaska), PBR is likely 
biased low for the entire stock (Muto et al. 2018). Population trends 
and status of this stock relative to its Optimum Sustainable Population 
are currently unknown.
Dall's Porpoise
    Dall's porpoise are widely distributed across the entire North 
Pacific Ocean. They are found over the continental shelf adjacent to 
the slope and over deep (greater than 2,500 m) oceanic waters and have 
been sighted throughout the North Pacific as far north as 65[deg] N 
(Hall 1979; Buckland et al. 1993). The only apparent distribution gaps 
in Alaska waters are upper Cook Inlet and the shallow eastern flats of 
the Bering Sea. They are present during all months of the year in much 
of the eastern North Pacific, although they may make seasonal onshore-
offshore movements along the west coast of the continental United 
States and winter movements out of areas with ice (Hall 1979; 
Leatherwood and Fielding 1974; Loeb 1972).
    Currently one stock of Dall's porpoise is recognized in Alaskan 
waters (Muto et al. 2018). Dahlheim et al. (2009) observed Dall's 
porpoise throughout Southeast Alaska, but only observed Dall's porpoise 
in Lynn Canal as far north as Haines, Alaska, about 15 miles south of 
Skagway. Infrequent observations (three to six) of Dall's porpoise have 
been observed in Taiya Inlet during the early spring and late fall, 
however they have not been observed near the project site near the 
Skagway waterfront (K. Gross, Never Monday Charters, personal 
communication reported in MOS 2016). At present, there is no reliable 
information on trends in abundance for the Alaska stock of Dall's 
porpoise (Muto et al. 2018). There are no subsistence uses of this 
species (Muto et al. 2018), however Dall's porpoise are vulnerable to 
fisheries-related entanglement and injury and to physical modifications 
of nearshore habitats resulting from urban and industrial development 
(including waste management and nonpoint source runoff), and noise 
(Linnenschmidt et al. 2013).

Pinnipeds

Steller Sea Lion

    The Steller sea lion is the largest of the eared seals (otariids), 
ranging along the North Pacific Rim from northern Japan to California, 
with centers of abundance and distribution in the Gulf of Alaska and 
Aleutian Islands. Steller sea lions use terrestrial haulout sites to 
rest and take refuge. They also gather on well-defined, traditionally 
used rookeries to pup and breed. These habitats are typically gravel, 
rocky, or sand beaches; ledges; or rocky reefs (Muto et al. 2018). 
Steller sea lion populations that primarily occur west of 144[deg] W 
(Cape Suckling, Alaska) comprise the western Distinct Population 
Segment (wDPS) or Western U.S. stock, while all others comprise the 
eastern DPS (eDPS) or Eastern U.S. stock; however, there is regular 
movement of both DPSs across this boundary (Muto et al. 2018). Both of 
these populations may occur in the action area, however in Lynn Canal/
Taiya Inlet Steller sea lions are most likely part of the eDPS/Eastern 
U.S. stock. Based on the percent of branded animals at Gran Point it is 
estimated that 2 percent of the sea lions in the project area are 
potentially from the wDPS/Eastern U.S. stock (personal communication, 
L. Jemison Alaska Department of Fish and Game, 2017). Steller sea lions 
were listed as threatened range-wide under the ESA on 26 November 1990 
(55 FR 49204). Steller sea lions were subsequently partitioned into the 
western and eastern DPSs in 1997, with the wDPS being listed as 
endangered under the ESA and the eDPS remaining classified as 
threatened (62 FR 24345) until it was delisted in November 2013. In 
August 1993, NMFS published a final rule designating critical habitat 
for the Steller sea lion as a 20-nautical mile buffer around all major 
haul-outs and rookeries, as well as associated terrestrial, air and 
aquatic zones, and three large offshore foraging areas (50 CFR 
226.202). There is no Steller sea lion critical habitat located in the 
action area.
    Gran Point, which is located 24 mi (38 km) south of the project 
area, is the closest year-round Steller sea lion haulout. However, 
during the spring eulachon run, a seasonal haulout site is located on 
Taiya Point at the southern tip of Taiya Inlet, approximately 11 mi (18 
km) from the project site. Twenty-five to 40 sea lions are estimated to 
use this haulout for about three weeks during spring run, during which 
they frequently are observed in the inlet. The eulachon run (which 
occurs for approximately three to four weeks during mid-March through 
May) in Lynn Canal is important to Steller sea lions for seasonal 
foraging. These spawning aggregations of forage fish provide densely 
aggregated, high-energy prey for Steller sea lions (and harbor seals) 
for brief time periods and influence haulout use (Sigler et al. 2004; 
Womble et al. 2005; Womble and Sigler 2006). The pre-spawning 
aggregations and spawning season for many forage fish species occur 
between March and

[[Page 64548]]

May in Southeast Alaska just prior to the breeding season of sea lions 
(Pitcher et al. 2001; Womble and Sigler 2006). After May, Steller sea 
lion presence in the project action area declines. During surveys 
conducted in 2002 and 2003, Womble et al. (2005) observed a maximum of 
approximately 400 Steller sea lions in the water at the mouth of the 
Taiya River feeding on eulachon in 2003, but observed very few in the 
same area in 2002. Steller sea lions have also been observed in Lutak 
Inlet, a foraging site closer to both Taiya Point and Gran Point 
haulouts.
    Steller sea lions are included in Alaska subsistence harvests. The 
mean annual subsistence take of Western U.S. Steller sea lions was 203 
from 2004-2016, and the mean annual take of Eastern U.S. Steller sea 
lions was 11 from 2005-2008 and 2012 (Muto et al. 2018). Entanglements 
in fishing gear and marine debris, and interactions with fishing gear 
are sources of mortality and serious injury for Steller sea lions. The 
Eastern U.S. stock is increasing with models indicating the rate of 
increase as 4.76 percent per year based on pup counts and 2.84 percent 
per year based on non-pup counts (Muto et al. 2018). Pup and non-pup 
counts of Western U.S. stock Steller sea lions in Alaska have increased 
1.78 percent per year and 2.14 per year respectively between 2002 and 
2017.

Harbor Seal

    Harbor seals range from Baja California north along the west coasts 
of Washington, Oregon, California, British Columbia, and Southeast 
Alaska; west through the Gulf of Alaska, Prince William Sound, and the 
Aleutian Islands; and north in the Bering Sea to Cape Newenham and the 
Pribilof Islands (Muto et al. 2018). They haul out on rocks, reefs, 
beaches, and drifting glacial ice, and feed in marine, estuarine, and 
occasionally fresh waters. Harbor seals generally are nonmigratory, 
with local movements associated with such factors as tides, weather, 
season, food availability, and reproduction (Scheffer and Slipp 1944; 
Fisher 1952; Bigg 1969, 1981; Hastings et al. 2004).
    Harbor seals in Alaska are partitioned into 12 separate stocks 
based largely on genetic structure: (1) The Aleutian Islands stock, (2) 
the Pribilof Islands stock, (3) the Bristol Bay stock, (4) the North 
Kodiak stock, (5) the South Kodiak stock, (6) the Prince William Sound 
stock, (7) the Cook Inlet/Shelikof stock, (8) the Glacier Bay/Icy 
Strait stock, (9) the Lynn Canal/Stephens Passage stock, (10) the 
Sitka/Chatham stock, (11) the Dixon/Cape Decision stock, and (12) the 
Clarence Strait stock. Only the Lynn Canal/Stephens Passage stock is 
considered in this analysis. The stock range includes north along the 
east and north coast of Admiralty Island from the north end of 
Kupreanof Island through Lynn Canal, including Taku Inlet, Tracy Arm, 
and Endicott Arm (Muto et al. 2018). The most current (2007-2011) 
estimate of the population trend for the stock is -176 seals per year, 
with a probability that the stock is decreasing of 0.71 (Muto et al. 
2018).
    Harbor seals are included in subsistence harvests. Annual harvests 
from the Lynn Canal/Stephens Passage in 2011 and 2012 were 50 animals 
each year, which is higher than previous estimates of 30 animals, on 
average, per year from 2004-2008 (Muto et al. 2018). Entanglement in 
fishing gear is also a large contributor to their annual human-caused 
serious injury/mortality.
    Additional information on the biology and local distribution of 
these species can be found in the NMFS Marine Mammal Stock Assessment 
Reports, which may be found at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

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 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. The functional groups and the associated 
frequencies are indicated below (note that these frequency ranges 
correspond to the range for the composite group, with the entire range 
not necessarily reflecting the capabilities of every species within 
that group):
     Low-frequency cetaceans (mysticetes): Generalized hearing 
is estimated to occur between approximately 7 Hz and 35 kHz;
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Generalized hearing is estimated to occur 
between approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; including two members 
of the genus Lagenorhynchus, on the basis of recent echolocation data 
and genetic data): Generalized hearing is estimated to occur between 
approximately 275 Hz and 160 kHz.
     Pinnipeds in water; Phocidae (true seals): Generalized 
hearing is estimated to occur between approximately 50 Hz to 86 kHz;
     Pinnipeds in water; Otariidae (eared seals): Generalized 
hearing is estimated to occur between 60 Hz and 39 kHz.
    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. 
Seven marine mammal species (five cetacean and two pinniped (one 
otariid and one phocid) species) have the reasonable potential to co-
occur with the proposed 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 
a mid-frequency cetacean (i.e., all delphinid and ziphiid species and 
the sperm whale), and two are classified as high-frequency cetaceans 
(i.e., harbor porpoise and Kogia spp.).

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

[[Page 64549]]

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 
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 impact pile driving, vibratory pile driving and removal, and 
drilling. 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 WP&YR'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 Impacts

    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 WP&YR'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

[[Page 64550]]

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. 2014b), 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. 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 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 impact pile driving, vibratory pile driving, 
and down-the-hole drilling. 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 haul-out 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,

[[Page 64551]]

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 (see 80 FR 60636 for Final IHA Federal Register 
notice). 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 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. 
Skagway Harbor contains an active port of call for cruise ships and 
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

    WP&YR construction activities at the Railroad Dock 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). During impact 
pile driving, elevated levels of underwater noise would ensonify Taiya 
Inlet where both fish and mammals occur and could affect foraging 
success.
    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. Local strong currents are anticipated to disburse suspended 
sediments produced by project activities at moderate to rapid rates 
depending on tidal stage. WP&YR would employ standard construction best 
management practices (BMPs; see section 11 and Appendix B 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 Lynn Canal/Taiya Inlet (e.g., most 
of the impacted area is limited to the northern and western portions of 
Taiya Inlet) and does not include any BIAs or ESA-designated critical 
habitat. Pile installation/removal and drilling may

[[Page 64552]]

temporarily increase turbidity resulting from suspended sediments. Any 
increases would be temporary, localized, and minimal. WP&YR 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 in Lynn Canal/
Taiya Inlet.
    The duration of the construction activities is relatively short. 
The construction window is for a maximum of 89 days and during each 
day, construction activities would only occur during daylight hours. 
Impacts to habitat and prey are expected to be minimal based on the 
short duration of activities.
    In-Water Construction Effects on Potential Prey (Fish)--
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 (on the order of 10 feet or less) 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 the Lynn Canal/Taiya Inlet 
region are routinely exposed to substantial levels of suspended 
sediment from glacial sources.
    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 impact and vibratory hammers and 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 low-frequency cetaceans, high-
frequency cetaceans, and/or phocids because predicted auditory injury 
zones are larger than for mid-frequency cetaceans and otariids. 
Auditory injury is unlikely to occur for mid-frequency cetaceans and 
otariids. 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

[[Page 64553]]

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. WP&YR's proposed activity includes the use of 
continuous (vibratory pile driving/removal and 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). 
WP&YR's proposed activity includes the use of impulsive (impact pile 
driving) and non-impulsive (vibratory pile driving/removal and 
drilling) sources.
    These thresholds are provided in Table 3. The references, analysis, 
and methodology used in the development of the thresholds are described 
in NMFS 2018 Technical Guidance, which may be accessed at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                         PTS onset thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  L,0-pk,flat: 219 dB; LE,,   LE,, LF,24h: 199 dB.
                                          LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  L,0-pk,flat: 230 dB; LE,,   LE,, MF,24h: 198 dB.
                                          MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  L,0-pk,flat: 202 dB;        LE,, HF,24h: 173 dB.
                                          LE,,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  L,0-pk.flat: 218 dB;        LE,,PW,24h: 201 dB.
                                          LE,,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  L,0-pk,flat: 232 dB;        LE,,OW,24h: 219 dB.
                                          LE,,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric 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 are recommended for consideration.
Note: Peak sound pressure level (L,0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
  exposure level (LE,) has a reference value of 1[micro]Pa\2\s. In this table, thresholds are abbreviated to be
  more reflective of International Organization for Standardization standards (ISO 2017). The subscript ``flat''
  is being included to indicate peak sound pressure are flat weighted or unweighted within the generalized
  hearing range of marine mammals (i.e., 7 Hz to 160 kHz). 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 weighted
  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 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). The maximum 
(underwater) ensonification area of 17.9 km \2\ due to project 
activities is governed by the topography of Taiya Inlet (see Figure 6 
in the application). The eastern shoreline of the inlet is acoustically 
shadowed due to land located just south of the proposed project site. 
Similarly, Yakutania Point and Dyea Point would inhibit transmission of 
project sounds from reaching Nahku Bay and the upper inlet at the mouth 
of the Taiya River. Additionally, vessel traffic and other commercial 
and industrial activities in the project area may contribute to 
elevated background noise levels which may mask sounds produced by the 
project.
    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.
    Empirical data from recent sound source verification (SSV) studies 
in Anchorage and Kodiak, Alaska were used to estimate sound source 
levels (SSLs) for impact pile driving, vibratory pile driving/removal, 
and down-the-hole drilling installations of the 42-inch steel pipe 
permanent piles and the 36-inch steel pipe template piles (Austin et 
al. 2016; Denes et al. 2016). These Alaskan construction sites were 
generally assumed to best represent the environmental conditions found 
in Skagway and represent the nearest available source level data for 
42-inch steel piles.
    Tables 4 provides the sound source values used in calculating 
harassment isopleths for each source type. No data are currently 
available for 42-inch steel

[[Page 64554]]

pipe piles. For impact and vibratory hammer source levels WP&YR used 
the median levels measured by Austin et al. (2016) during installation 
of 48-inch piles at Port of Anchorage (197.9 and 166.8 dB re 1 [mu]Pa 
(rms at 11 m)). These 48-inch pile impact and vibratory levels are 
conservatively used for both the 42-inch permanent piles and the 36-
inch template piles. Little SSL data are available for down-the-hole 
drilling. WP&YR used the 90th percentile source levels measured by 
Denes et al. (2016) during drilling down the center of 30-inch piles in 
Kodiak (171 dB re 1 [mu]Pa (rms at 10 m)).

                                Table 4--Source Levels and Anticipated Daily Durations for Underwater Sound Calculations
                                    [Hours or strikes per day represents the maximum duration of any single activity]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                Source                            Source type             SPLPK (dB)      SPLRMS (dB)     SELS	S (dB)       Hours or strikes per day
--------------------------------------------------------------------------------------------------------------------------------------------------------
Template Piles
    Vibratory Installation/Removal....  Non-impulsive, continuous.....             n/a           166.8             n/a  3 hours.
    Impact Installation...............  Impulsive, intermittent.......           212.5           197.9           186.7  2,000 strikes.
    Drilling Installation.............  Non-impulsive, continuous.....             n/a           171.0             n/a  6 hours.
Permanent Piles
    Vibratory Installation............  Non-impulsive, continuous.....             n/a           166.8             n/a  8 hours.
    Impact Installation...............  Impulsive, intermittent.......           212.5           197.9           186.7  2,000 strikes.
    Drilling Installation.............  Non-impulsive, continuous.....             n/a           171.0             n/a  8 hours.
--------------------------------------------------------------------------------------------------------------------------------------------------------

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


TL = B * Log10 (R1/R2),

Where:

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

A practical spreading value of fifteen is often used under conditions, 
such as at the WP&YR Railroad Dock, where water increases with depth as 
the receiver moves away from the shoreline, resulting in an expected 
propagation environment that would lie between spherical and 
cylindrical spreading loss conditions. Practical spreading loss is 
assumed here.
    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that ensonified area/volume could be more 
technically challenging to predict because of the duration component in 
the new thresholds, we developed a User Spreadsheet that includes tools 
to help predict a simple isopleth that can be used in conjunction with 
marine mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which may result in some degree of 
overestimate of Level A harassment take. However, these tools offer the 
best way to predict appropriate isopleths when more sophisticated 3D 
modeling methods are not available, and NMFS continues to develop ways 
to quantitatively refine these tools, and will qualitatively address 
the output where appropriate. For stationary sources such as pile 
driving and drilling, NMFS User Spreadsheet predicts the closest 
distance at which, if a marine mammal remained at that distance (or 
greater) the whole duration of the activity, it would not incur PTS. 
Inputs used in the User Spreadsheet and the resulting isopleths are 
reported in Tables 5 and 6. As WP&YR plans to employ two continuous 
sound sources (vibratory pile driving and drilling) it is necessary to 
account for accumulation of sound caused by both activities during the 
full 10 hour work day when calculating Level A harassment isopleths. As 
drilling has the higher sound pressure level we propose to use drilling 
to calculate the Level A harassment isopleths for both drilling and 
vibratory pile driving activities (Table 5). For impact pile driving, 
isopleths calculated using the SELCUM metric will be used as 
it produces larger isopleths than SPLPK. Isopleths for Level 
B harassment associated with impact pile driving (160 dB) and vibratory 
pile driving/removal and drilling (120 dB) were also calculated and are 
can be found in Table 6.

     Table 5--User Spreadsheet Input Parameters Used for Calculating
                          Harassment Isopleths
------------------------------------------------------------------------
                                                       Vibratory pile
          Parameter            Impact pile driving  driving and drilling
------------------------------------------------------------------------
Spreadsheet Tab Used........  E.1) Impact pile      A.1) Drilling/
                               driving.              Vibratory pile
                                                     driving.
Source Level................  186.7 dB SEL........  171 dB rms.
Weighting Factor Adjustment   2...................  2.
 (kHz).
Number of strikes per day...  2,000...............  N/A.
Activity Duration (h) within  N/A.................  10 hours.
 24-hour period.
Propagation (xLogR).........  15LogR..............  15LogR.
Distance of source level      11..................  10.
 measurement (meters).
------------------------------------------------------------------------


[[Page 64555]]


         Table 6--Calculated Distances to Level A Harassment and Level B Harassment Isopleths During Pile Installation and Removal and Drilling
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                               Level A harassment zone (meters)                              Level B
                                                       --------------------------------------------------------------------------------  harassment zone
                                                                                                                                            (meters)
                        Source                          Low- frequency  Mid- frequency       High-          Phocid          Otariid    -----------------
                                                           cetacean        cetacean        frequency       pinniped        pinniped       Cetaceans and
                                                                                           cetacean                                         pinnipeds
--------------------------------------------------------------------------------------------------------------------------------------------------------
Drilling and Vibratory Installation...................             148             8.3           129.7            79.2             5.8        \1\ 13,000
Impact Installation...................................         3,077.2           109.4         3,665.4         1,646.8           119.9           3,698.8
rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
Source................................................                                  PTS Onset Isopleth--Peak (meters)
rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
Impact Installation...................................             4.1             n/a            55.1             4.7             n/a  ................
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Based on maximum distance before landfall. Calculated distance was 25.1 km.

Marine Mammal Occurrence and Take Calculation and Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations, and how this information is brought together to produce a 
quantitative take estimate.
    Density information is not available for marine mammals in the 
project area in Taiya Inlet. Potential exposures to impact and 
vibratory pile driving noise for each threshold for all other marine 
mammals were estimated using published reports of group sizes and 
population estimates, and anecdotal observational reports from local 
commercial entities. For several species, it is not currently possible 
to identify all observed individuals to stock.

Level B Harassment Calculations

    The estimation of takes by Level B harassment uses the following 
calculation:
    Level B harassment estimate = N (number of animals in the 
ensonified area) * Number of days of noise generating activities.

Humpback Whale

    Humpback whales are the most commonly observed baleen whale in 
Southeast Alaska, particularly during spring and summer months. 
Humpback whales in Alaska, although not limited to these areas, return 
to specific feeding locations such as Frederick Sound, Chatham Strait, 
North Pass, Sitka Sound, Glacier Bay, Point Adolphus, and Prince 
William Sound, as well as other similar coastal areas (Wing and Krieger 
1983). In Lynn Canal they have been observed in the spring and fall 
from Haines to Juneau, however scientific surveys have not documented 
the species within Taiya Inlet (Dahlheim et al. 2009).
    Local observations indicate that humpback whales are not common in 
the project action area but, if they are sighted, are generally present 
during mid to late spring and vacate the area by July to follow large 
aggregations of forage fish in lower Lynn Canal. Local observers have 
reported humpback whales in Taiya Inlet, sometimes fairly close to the 
Skagway waterfront. Due to seasonal migration patterns, the low 
frequency of humpbacks in the area, and that no humpback whales have 
been reported during winter months it is anticipated that no humpback 
whales will be present in the project area in February. On average, 
four to five individuals may occur near Skagway during the spring 
eulachon run in April and May, after which, only a few individuals are 
observed throughout the summer. In 2015, only one whale was observed 
(for several) weeks close to Skagway (K. Gross, personal communication 
reported in MOS 2016). Based on humpback whale occurrence in the 
project area and local observations, it is estimated that four 
individuals may be present in the action area each day during April, 
coinciding with 30 days of project activity (120 exposures). As it is 
unclear whether humpback whales occur in the inlet in March (for 
example, should the eulachon run begin early), it is conservatively 
estimated that one whale might be found in the inlet during that month 
for five days (0.16 whales per day, 5 exposures), for an overall total 
of 125 exposures (Table 7).

                              Table 7--Estimated Takes of Humpback Whales per Month
----------------------------------------------------------------------------------------------------------------
                                                                    Animals in
                              Month                                inlet per day   Days in month     Exposures
----------------------------------------------------------------------------------------------------------------
February........................................................               0              28               0
March...........................................................            0.16              31               5
April...........................................................               4              30             120
                                                                 -----------------------------------------------
    Total.......................................................  ..............  ..............             125
----------------------------------------------------------------------------------------------------------------

Minke Whale

    Minke whales are rarely observed in the project area, and 
scientific surveys have not documented the species within Taiya Inlet 
(Dahlheim et al. 2009). A single minke whale was observed in the inlet 
in 2015 (K. Gross, Never Monday Charters, personal communication; R. 
Ford, Taiya Inlet Watershed Council, both personal communications 
reported in MOS 2016), and is the only known record of a minke whale in 
Taiya Inlet. However one minke whale was reported by local observers in 
the action area in 2015. Based on the available information it is very 
unlikely minke whales will be present in the inlet, however, minke 
whale presence is possible based on a single sighting and presence of 
potential prey (eulachon) in the spring. Thus, we estimate a total of

[[Page 64556]]

two potential exposures of minke whales.

Killer Whale

    Although killer whale stocks' ranges include southeast Alaska, they 
have only been documented as far north as Lynn Canal; therefore, while 
possible, occurrence north of Lynn Canal into Taiya Inlet is rare. 
According to local observations, pods of resident killer whales are 
occasionally seen in Taiya Inlet. Local observations indicate killer 
whales are observed four or five times a year (between spring and fall) 
usually in a group of 15 to 20 whales. In 2015 a resident pod was only 
observed in Taiya Inlet twice, remaining for one to four days per visit 
(K. Gross, personal communication reported in MOS 2016). There is no 
evidence of transient whales occurring within Taiya Inlet. While the 
resident pods remain in Alaska year-round there are no reports of 
sightings during winter months (January-February) in Taiya Inlet so it 
is assumed no killer whales will be present in the project area in 
February. Based on local observations in the project area in the 
spring, it is assumed that a group of 20 whales may enter the project 
area once in each of March and April and remain within the inlet for 
two days each time, for a total of 80 potential exposures.

Harbor Porpoise

    Harbor porpoises are primarily found in coastal waters, and in the 
Gulf of Alaska and Southeast Alaska, they occur most frequently in 
waters less than 100 meters (Dahlheim et al. 2009). Dedicated research 
studies of harbor porpoise in the project area only occur as far north 
in Lynn Canal as Haines during the summer (Dahlheim et al. 2009; 2015), 
approximately 16 miles south of Skagway. Group sizes were, on average, 
between 1.37-1.59 animals (less than 2) (Dahlheim et al. 2009; 2015). 
In Lynn Canal, observations were less frequent, primarily in lower Lynn 
Canal from Chatham Strait to Juneau, though harbor porpoises have been 
observed as far north as Haines during the summer (Dahlheim et al. 
2009; 2015).
    Despite lack of observations during dedicated surveys, local 
charter captains indicate that harbor porpoises commonly occur in small 
groups of two or three in Taiya Inlet, although they are not 
encountered on a daily basis and are rarely seen in areas close to the 
waterfront (K. Gross, personal communication reported in MOS 2016). 
Therefore, it is conservatively estimated that one group of three 
individuals may be present in the inlet 75 percent of the days during 
each month (or 2.25 porpoises per day on average) for a total of 201 
potential exposures (Table 8).

                             Table 8--Estimated Takes of Harbor Porpoises per Month
----------------------------------------------------------------------------------------------------------------
                                                                    Animals in
                              Month                                inlet per day   Days in month     Exposures
----------------------------------------------------------------------------------------------------------------
February........................................................            2.25              28              63
March...........................................................            2.25              31              70
April...........................................................            2.25              30              68
                                                                 -----------------------------------------------
    Total.......................................................  ..............  ..............             201
----------------------------------------------------------------------------------------------------------------

Dall's Porpoise

    Dall's porpoises are widely distributed across the entire North 
Pacific Ocean. Throughout most of the eastern North Pacific they are 
present during all months of the year, although there may be seasonal 
onshore-offshore movements along the west coast of the continental 
United States and winter movements of populations out of Prince William 
Sound and areas in the Gulf of Alaska and Bering Sea (Muto et al. 
2018). Dahlheim et al. (2009) observed Dall's porpoise throughout 
Southeast Alaska, with concentrations of animals consistently found in 
Lynn Canal, Stephens Passage, Icy Strait, upper Chatham Strait, 
Frederick Sound, and Clarence Strait. Dahlheim et al. (2009), 
documented Dall's porpoise in Lynn Canal as far north as Haines, 
Alaska, about 15 miles south of Skagway.
    Local observation indicate that three to six Dall's porpoises may 
be present in Taiya Inlet during the early spring and late fall. 
Observations have been occasional to sporadic and do not occur on a 
daily basis. The species has not been observed during winter months and 
has not been observed near the waterfront (K. Gross, personal 
communication reported in MOS 2016). The mean group size of Dall's 
porpoise in Southeast Alaska is estimated to be 3.7 individuals 
(Dahlheim et al. 2009). Therefore, it is estimated that a group of four 
Dall's porpoises will be present in the project area every other day in 
March and April (2 per day), for a total of 122 potential exposures 
(Table 9).

                             Table 9--Estimated Takes of Dall's Porpoises per Month
----------------------------------------------------------------------------------------------------------------
                                                                    Animals in
                              Month                                inlet per day   Days in month     Exposures
----------------------------------------------------------------------------------------------------------------
February........................................................               0              28               0
March...........................................................               2              31              62
April...........................................................               2              30              60
                                                                 -----------------------------------------------
    Total.......................................................  ..............  ..............             122
----------------------------------------------------------------------------------------------------------------

Steller Sea Lion

    Several long-term Steller sea lion haulouts are located in Lynn 
Canal, however none occur in Taiya Inlet. The nearest long-term Steller 
sea lion haulout is located at Gran Point, south of Haines and 24 mi 
(38 km) south of the project area. Other year-round haulouts in Lynn 
Canal are present at Met Point, Benjamin Island, and Little Island, 
closer to Juneau (Fritz et al. 2015). Observations from local charter 
boat captains and watershed stewards indicate Steller sea lions can be 
abundant in the action area, particularly in April and May during the 
eulachon run, but are rarely observed in the project area during the 
winter (K. Gross,

[[Page 64557]]

Never Monday Charters, personal communication; R. Ford, Taiya Inlet 
Watershed Council, personal communication reported in MOS 2016). This 
is consistent with the National Marine Mammal Laboratory database 
(Fritz et al. 2015), which has identified the largest number of Lynn 
Canal sea lions during the fall and winter months at Benjamin Island in 
the lower reaches of the canal. During surveys conducted in 2002 and 
2003, Womble et al. (2005) observed a maximum of approximately 400 
Steller sea lions in the water at the mouth of the Taiya River feeding 
on eulachon in 2003, but observed very few in the same area in 2002. 
Steller sea lions have also been observed in Lutak Inlet, a foraging 
site closer to both Taiya Point and Gran Point haulouts.
    During the spring eulachon run, a seasonal haulout site is located 
on Taiya Point at the southern tip of Taiya Inlet, approximately 11 mi 
(18 km) from the project site. Twenty-five to 40 sea lions are 
estimated to use this haulout for about three weeks during spring run, 
during which they frequently are observed in the inlet (K. Gross, 
personal communication reported in MOS 2016). However, most animals 
leave the inlet shortly after the eulachon run and are rarely observed 
in the summer. Based on survey data and local observations in the 
project area, it is estimated that two animals may be present each day 
in February, 16 animals may be present on each day in March (half of 
the mean found on Taiya Rocks during the eulachon run), and 40 animals 
may be present each day in April for a total of 1,032 potential 
exposures (Table 10).

                            Table 10--Estimated Takes of Steller Sea Lions per Month
----------------------------------------------------------------------------------------------------------------
                                                                    Animals in
                              Month                                inlet per day  Days in  month     Exposures
----------------------------------------------------------------------------------------------------------------
February........................................................               2              28              56
March...........................................................              16              31             496
April...........................................................              40              30           1,200
                                                                 -----------------------------------------------
    Total.......................................................  ..............  ..............           1,752
----------------------------------------------------------------------------------------------------------------

Harbor Seal

    No long-term haulout sites have been documented for harbor seals in 
Taiya Inlet; however, seasonal haulouts are present within six miles of 
the project area at Seal Cove and at the mouth of the Taiya River. 
Based on reports from local observers, a few resident harbor seals are 
expected to occur within Taiya Inlet during the winter months, but 
during the April and May eulachon run numbers can range from 20 to over 
100 (K. Gross and R. Ford, personal communication reported in MOS 
2016). Before and after the spawning run, much lower numbers of harbor 
seals are present.
    Based on survey data and local observations in the project area it 
is assumed that 20 seals (the lower estimate in the range) occur within 
the project area each day in February through March (560 takes in 
February and 620 takes in March) and 100 seals (the higher estimate in 
the range) during April (3,000 takes) for a total of 4,180 potential 
exposures (Table 11).

                               Table 11--Estimated Takes of Harbor Seals per Month
----------------------------------------------------------------------------------------------------------------
                                                                    Animals in
                              Month                                inlet per day  Days in  month       Takes
----------------------------------------------------------------------------------------------------------------
February........................................................              20              28             560
March...........................................................              20              31             620
April...........................................................             100              30           3,000
                                                                 -----------------------------------------------
    Total.......................................................  ..............  ..............           4,180
----------------------------------------------------------------------------------------------------------------

Level A Harassment Calculations

    WP&YR intends to avoid Level A harassment take by shutting down 
installation activities at approach of any marine mammal to the 
representative Level A harassment (PTS onset) ensonification zone up to 
a practical shutdown monitoring distance. As small/cryptic marine 
mammal species may enter the Level A harassment zone before shutdown 
mitigation procedures can be implemented, and some animals may occur 
between the maximum Level A harassment ensonification zone and the 
maximum shutdown safety zone, we conservatively estimate that 20 
percent of the Level B harassment takes calculated above for humpback 
whales, harbor porpoises, Dall's porpoises, and harbor seals, have the 
potential to be takes by Level A harassment (Table 12). Minke whale 
occurrence in Taiya Inlet is rare. Because vessel-based PSO are able to 
monitoring the entire Level A harassment zone (whales entering the 
inlet), WP&YR did not request, and NMFS is not proposing, to authorize 
Level A harassment take of minke whales.

           Table 12--Estimated Take by Level A and Level B Harassment, by Species and Stock, Resulting From Proposed WP&YR Project Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                          Proposed  take
                Common name                             Stock                  Stock          Level A         Level B          Total      as  percentage
                                                                           abundance \1\                                   proposed take      of stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale............................  Central North Pacific.......       \2\10,103              25             100             125            1.23
Minke Whale...............................  Alaska......................             N/A               0               2               2             N/A

[[Page 64558]]

 
Killer whale..............................  Alaska Resident.............           2,347               0              80              80             3.4
                                            Northern Resident...........             261                                                            30.6
                                            Gulf of Alaska, Aleutian                 587                                                            13.6
                                             Islands, Bering Sea
                                             Transient.
                                            West Coast Transient........             243                                                            32.9
Harbor porpoise...........................  Southeast Alaska............             975              40             161             201            20.6
Dall's porpoise...........................  Alaska......................          83,400              24              98             122            0.01
Steller sea lion..........................  Western U.S.................          54,267               0           \3\35              35            0.06
                                            Eastern U.S.................          41,638               0           1,717           1,717             4.1
Harbor seal...............................  Lynn Canal/Stephens Passage.           9,478             836           3,344           4,180            44.1
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Stock or DPS size is Nbest according to NMFS 2018 Draft Stock Assessment Reports.
\2\ For ESA section 7 consultation purposes, 6.1 percent are designated to the Mexico DPS and the remaining are designated to the Hawaii DPS; therefore,
  we assigned 2 Level B takes to the Mexico DPS.
\3\ Based on the percent of branded animals at Gran Point and in consultation with the Alaska Regional Office, we used a 2 percent distinction factor to
  determine the number of animals potentially from the western DPS.

    There are a number of reasons why the estimates of potential 
incidents of take are likely to be conservative. Given the lack of 
density information, we use conservative estimates of marine mammal 
presence to calculate takes for each species. Additionally, in the 
context of stationary activities such as pile driving, and in areas 
where resident animals may be present, this number represents the 
number of instances of take that may occur to a small number of 
individuals, with a notably smaller number of animals being exposed 
more than once per individual. While pile driving or drilling can occur 
any day throughout the in-water work window, and the analysis is 
conducted on a per day basis, only a fraction of that time is actually 
spent pile driving. The potential effectiveness of mitigation measures 
in reducing the number of takes is also not quantified in the take 
estimation process. For these reasons, these take estimates may be 
conservative, especially if each take is considered a separate 
individual animal, and especially for pinnipeds.

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 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.

Mitigation for Marine Mammals and Their Habitat

    In addition to the measures described later in this section, WP&YR 
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. This 
type of work could include the following activities: (1) Movement of 
the barge to the pile location; or (2) positioning of the pile on the 
substrate via a crane (i.e., stabbing the pile);
     Work may only occur during daylight hours, when visual 
monitoring of marine mammals can be conducted;
     For those marine mammals for which Level B harassment take 
has not been requested, 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 would apply to WP&YR's mitigation 
requirements:
    Establishment of Shutdown Zone for Level A Harassment--For all pile

[[Page 64559]]

driving/removal and drilling activities, WP&YR would establish a 
shutdown zone. The purpose of a shutdown zone is generally to define an 
area within which shutdown of activity would occur upon sighting of a 
marine mammal (or in anticipation of an animal entering the defined 
area). Conservative shutdown zones of 150 m for low- and high- 
frequency cetaceans, 80 m for phocid pinnipeds, and 10 m for mid-
frequency cetaceans and otariid pinnipeds would be used during all 
drilling and vibratory pile driving/removal activities to prevent 
incidental Level A harassment exposure for these activities (Table 13). 
During impact pile driving a 150 m zone would be used for all species 
except for low-frequency cetacean for which a 2,000 m zone will be 
used. These shutdown zones would be used to prevent incidental Level A 
exposures from impact pile driving for mid-frequency cetaceans and 
otariid pinnipeds, and to reduce the potential for such take for other 
species (Table 13). The placement of Protected Species Observers (PSOs) 
during all pile driving and drilling activities (described in detail in 
the Monitoring and Reporting Section) will ensure shutdown zones are 
visible. The 150 m zone is the practical distance WP&YR anticipates 
phocid pinnipeds and high-frequency cetaceans can be effectively 
observed in the project area. The 2,000 m zone for low-frequency 
cetaceans is determined by the width of Taiya Inlet at Skagway Harbor. 
Observers will be present on vessels in the Taiya Inlet and able to 
observe large whales traveling north into the inlet and project area.

    Table 13--Monitoring and Shutdown Zones for Each Project Activity
------------------------------------------------------------------------
                                   Monitoring
             Source                 zone  (m)       Shutdown zone  (m)
------------------------------------------------------------------------
Drilling and Vibratory                   13,000  Low- and high-
 Installation/Removal.                            frequency cetaceans:
                                                  150.
                                                 Phocid pinnipeds: 80.
                                                 Mid-frequency cetaceans
                                                  and otariid pinnipeds:
                                                  10.
Impact Installation............           3,400  Low-frequency
                                                  cetaceans: 2,000.
                                                 All other species: 150.
------------------------------------------------------------------------

    Establishment of Monitoring Zones for Level B Harassment--WP&YR 
would establish monitoring zones to correlate with Level B disturbance 
zones or zones of influence 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 
proposed monitoring zones are described in Table 13. The monitoring 
zone for drilling and vibratory pile driving/removal activities is 
13,000 m, corresponding to the maximum distance before landfall. 
Placement of PSOs on vessels in the Taiya Inlet allow PSOs to observe 
marine mammals traveling north into the inlet and Skagway Harbor. 
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 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 
would 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 would be conducted a total of three times before 
impact pile driving begins. Soft start would 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 Level B 
harassment 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 Level B monitoring zone. When a marine mammal permitted for 
Level B take is present in the Level B harassment zone, activities may 
begin and Level B take will be recorded. As stated above, if the entire 
Level B zone is not visible at the start of construction, piling or 
drilling activities can begin. If work ceases for more than 30 minutes, 
the pre-activity monitoring of both the Level B and shutdown zone will 
commence.
    Due to the depth of the water column and strong currents present at 
the project site, bubble curtains would 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 to ensuring that the most value is obtained from 
the required monitoring.

[[Page 64560]]

    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); and
     Mitigation and monitoring effectiveness.

Marine Mammal Visual Monitoring

    Monitoring shall be conducted by NMFS-approved observers. Trained 
observers shall be placed from the best vantage point(s) 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 would 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 total of five PSOs would be based on land and vessels. During all 
pile driving/removal and drilling activities observers will be 
stationed at the Railroad Dock, Yakutania Point, and Dyea Point. These 
stations will allow full monitoring of the impact hammer monitoring 
zone and the Level A shutdown zones. The vibratory and drilling 
monitoring zone will be additionally monitored using two PSOs stationed 
on boats anchored near the shoreline, with each team (vessel operator 
and observer) stationed approximately 2 km apart in the inlet south of 
the project site (Figure 2 in the WP&YR Marine Mammal Mitigation and 
Monitoring Plan).
    PSOs would scan the waters using binoculars, and/or spotting 
scopes, and would use a handheld GPS or range-finder device to verify 
the distance to each sighting from the project site. All PSOs would 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. WP&YR would 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.
    (iv) Where a team of three or more observers are required, one 
observer shall be designated as lead observer or monitoring 
coordinator. The lead observer must have prior experience working as an 
observer.
    (v) WP&YR 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.
    A draft marine mammal monitoring report would 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;
     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, WP&YR 
would immediately cease the

[[Page 64561]]

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 would 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 would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with WP&YR to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. WP&YR would not be able to 
resume their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that WP&YR 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), 
WP&YR would 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 would include the same information 
identified in the paragraph above. Activities would be able to continue 
while NMFS reviews the circumstances of the incident. NMFS would work 
with WP&YR to determine whether modifications in the activities are 
appropriate.
    In the event that WP&YR 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), WP&YR would 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. WP&YR would provide photographs, video footage (if 
available), or other documentation of the stranded animal sighting to 
NMFS and the Marine Mammal Stranding Network.

Acoustic Monitoring

    WP&YR will conduct acoustic monitoring for the purposes of SSV. 
WP&YR will collect acoustic data for at least one 42-inch permanent 
pile, using all three installation methods (impact pile driving, 
vibratory pile driving, and down-the-hole drilling) from at least two 
distances from the pile (one approximately 10 meters from the pile and 
at least one additional measurement in the far field). The following 
data, at minimum, shall be collected during acoustic monitoring and 
reported:
     Hydrophone equipment and methods: recording device, 
sampling rate, distance from the pile where recordings were made; depth 
of recording device(s);
     Type of pile (42-inch), and segment of pile (1, 2, or 3), 
being driven and method of driving/removal or drilling during 
recordings; and
     Mean, median, maximum (or 90th percentile), and range 
sound levels (dB re 1[micro]Pa): cumulative sound exposure level 
(SELCUM), peak sound pressure level (SPLPK), root 
mean square sound pressure level (SPLRMS), and single-strike 
sound exposure level (SELS-S) as appropriate for the sound 
source.
    For more details please see WP&YR's acoustic monitoring plan, 
available at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS' implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    Pile driving/removal and drilling activities associated with the 
Railroad Dock installation project as outlined previously, have the 
potential to disturb or displace marine mammals. 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 would be due to 
potential behavioral disturbance, TTS, and PTS. 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 humpback whales, 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 Proposed Mitigation section).
    As described previously, minke whales are considered rare in the 
proposed project area and we have proposed to authorize only nominal 
and precautionary take of two individuals. Therefore, we do not expect 
meaningful impacts to minke whales and preliminarily find that the 
total minke whale 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; HDR, Inc. 2012; Lerma 2014; ABR 2016). 
Most likely, individuals will simply move away from the sound source 
and be temporarily displaced

[[Page 64562]]

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 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 simply avoid the area while the activity is 
occurring. While vibratory driving and drilling associated with the 
proposed 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 simply 
avoid the area and use more-preferred habitats.
    In addition to the expected effects resulting from authorized Level 
B harassment, we anticipate that humpback whales, 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, i.e. the low-frequency region below 2 kHz, not severe hearing 
impairment or impairment in the regions of greatest hearing 
sensitivity. If hearing impairment occurs, it is most likely that the 
affected animal would lose a few decibels in its hearing sensitivity, 
which in most cases is not likely to meaningfully affect its ability to 
forage and communicate with conspecifics. 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 
would 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;
     Conduct the majority of pile driving/removal and drilling 
work outside of the eulachon run, minimizing harassment of marine 
mammals during important foraging times;
     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 consist 
of, at worst, temporary modifications in behavior that would not 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 does 
not include habitat areas of special significance (BIAs or ESA-
designated critical habitat); and
     The presumed efficacy of the proposed mitigation measures 
in reducing the effects of the specified activity to the level of least 
practicable adverse impact.
    In addition, although affected humpback whales and Steller sea 
lions may be from a DPS that is listed under the ESA, it is unlikely 
that minor noise effects in a small, localized area of habitat would 
have any effect on the stocks' ability to recover. In combination, we 
believe that these factors, as well as the available body of evidence 
from other similar activities, demonstrate that the potential effects 
of the specified activities will have only minor, short-term effects on 
individuals. The specified activities are not expected to impact rates 
of recruitment or survival and will therefore not result in population-
level impacts.
    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 12 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 proposed work in the WP&YR project area. With the 
exception of the Northern Resident and West Coast Transient killer 
whale stocks and harbor seals, our analysis shows that less than 25 
percent of each affected stock could be taken by harassment. The 
numbers of animals proposed 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.
    The total proposed authorized take for killer whales as compared to 
each potentially affected stock ranges from 3.4 percent to 32.9 percent 
of each stock abundance. In reality, it is highly unlikely that 80 
individuals of any one killer whale stock will be temporarily harassed. 
Instead, it is assumed that there will be a relatively brief period of 
takes of a smaller number of the same individuals from any stock (20, 
which is representative of the estimated group size, or 40, if 
individuals from the same stock are taken), which would result in 
smaller percentages of stocks (ranging from 0.9 percent to 8.2 percent 
if 20 whales from the same stock, or 1.7 percent to 16.5 percent if 40 
whales from the same stock). We make this assumption because the Alaska 
and Northern resident stocks are known to occasionally occur in Taiya 
Inlet, but other stocks' (e.g., transients) range extends into the 
project area, and therefore they may occur in the upper reaches of Lynn 
Canal into Taiya Inlet towards Skagway, albeit infrequently. Takes are 
not assumed to include multiple harassments of the same individual(s), 
resulting in estimates of

[[Page 64563]]

proposed take as a percentage of stock abundance that are high compared 
to actual take that will occur. This is the case with the resident 
stocks of killer whale and harbor seal (Lynn Canal/Stephens Passage 
stock).
    As reported, a small number of harbor seals, most of which reside 
in Taiya Inlet year-round, will be exposed to construction activities 
for three months. 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, which results in an estimated density of 
36 animals within Taiya Inlet. The largest Level B harassment zone 
within the inlet occupies 17.9 km\2\, which represents less than 0.4 
percent of the total geographical area occupied by the stock. The great 
majority of these exposures will be to the same animals given their 
residency patterns.
    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

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. The proposed 
project will occur near but not overlap with the subsistence area used 
by the villages of Hoonah and Angoon (Wolfe et al. 2013; N. Kovaces, 
Skagway Traditional Council, personal communication). Harbor seals and 
Steller sea lions are available for subsistence harvest in this area 
(Wolfe et al. 2013). 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

    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 Regional Office, 
whenever we propose to authorize take for endangered or threatened 
species.
    NMFS is proposing to authorize take of the Steller sea lion western 
DPS and humpback whale Mexico DPS, which are listed under the ESA. On 
November 29, 2018, the NMFS Office of Protected Resources has requested 
initiation of section 7 consultation with the Alaska Regional Office 
for the issuance of this IHA. NMFS will conclude the ESA consultation 
prior to reaching a determination regarding the proposed issuance of 
the authorization.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to WP&YR for conducting the Railroad Dock dolphin 
installation project in Skagway, Alaska from February 1, 2019 through 
April 30, 2019, provided the previously mentioned mitigation, 
monitoring, and reporting requirements are incorporated. A draft of the 
IHA itself is available for review in conjunction with this notice at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities

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 
action. We also request comment on the potential for 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 our final decision on the request for MMPA authorization.
    On a case-by-case basis, NMFS may issue a second one-year IHA 
without additional notice when (1) another year of identical or nearly 
identical activities as described in the Specified Activities section 
is planned or (2) the activities would not be completed by the time the 
IHA expires and a second IHA would allow for completion of the 
activities beyond that described in the Dates and Duration section, 
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 beyond the 
initial dates either are identical to the previously analyzed 
activities or include changes so minor (e.g., reduction in pile size) 
that the changes do not affect the previous analyses, take estimates, 
or mitigation and monitoring requirements.
    (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 remain the same and appropriate, 
and the original findings remain valid.

     Dated: December 12, 2018.
Donna S. Weiting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2018-27258 Filed 12-14-18; 8:45 am]
 BILLING CODE 3510-22-P