Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Auke Bay Ferry Terminal Modifications and Improvements Project in Juneau, Alaska, 22453-22473 [2019-10326]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 84, Number 96 (Friday, May 17, 2019)]
[Notices]
[Pages 22453-22473]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-10326]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XG947


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Auke Bay Ferry Terminal 
Modifications and Improvements Project in Juneau, 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 the Alaska Department of 
Transportation and Public Facilities (ADOT&PF) for authorization to 
take marine mammals incidental to the Auke Bay Ferry Terminal 
Modifications and Improvements Project in Juneau, 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 June 17, 
2019.

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

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

SUPPLEMENTARY INFORMATION:

Background

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

[[Page 22454]]

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 January 17, 2019, NMFS received a request from ADOT&PF for an 
IHA to take marine mammals incidental to pile driving activities at the 
Auke Bay Ferry Terminal in Juneau, Alaska. The application was deemed 
adequate and complete on April 1, 2019. ADOT&PF's request is for take 
of a small number of seven species of marine mammals by Level B 
harassment and Level A harassment. Neither ADOT&PF nor NMFS expects 
serious injury or mortality to result from this activity and, 
therefore, an IHA is appropriate.

Description of Proposed Activity

Overview

    ADOT&PF is proposing to modify and improve the existing dolphin 
structures at the Auke Bay Ferry Terminal. There are currently three 
Alaska Marine Highway System ferry berths in Auke Bay. The proposed 
project will involve the East Stern Berth facility, which was 
originally constructed in 2003 to accommodate new fast vehicle ferries. 
The East Stern Berth must be renovated to accommodate two new Alaska-
class ferries, which will enter service in spring 2020. Four existing 
dolphins at the ferry terminal will be removed using a vibratory 
driver, and three breasting dolphins and two mooring dolphins will be 
installed using both vibratory and impact hammers. Vibratory pile 
removal and installation and impact pile installation would introduce 
underwater sounds at levels that may result in take, by Level A and 
Level B harassment, of marine mammals in Auke Bay.

Dates and Duration

    Construction is scheduled to begin in November 2019 and continue 
through April 2020. Pile driving will be intermittent during this 
period, depending on weather, construction and mechanical delays, and 
logistical constraints. Pile installation and removal can occur at 
variable rates, from a few minutes to several hours per day. Vibratory 
pile installation and removal will occur over 27 non-consecutive days 
within the 6-month construction window. Impact installation will occur 
intermittently on 12 of those 27 days.

Specific Geographic Region

    Auke Bay is an estuary at the southern end of Lynn Canal, located 
approximately 18 kilometers (km) (11 miles (mi)) north-northwest of 
downtown Juneau. The bay is one of many that lead to a larger system of 
glacial fjords connecting various channels with the open ocean. Auke 
Bay is approximately 130 km (80.7 mi) inland from the Gulf of Alaska 
(Figure 1). Auke Bay contains several small islands and reefs within 
the 11 square kilometer (km\2\) (4.25 square mile (mi\2\)) embayment. 
While most of the bay is relatively shallow, reaching depths of 40 to 
60 meters (m) (131 to 197 feet (ft)), depths of more than 100 m (328 
ft) are found near Coghland Island (see Figure 1-2 in the IHA 
application). Pile installation and removal at the ferry terminal will 
occur in waters ranging in depth from less than 1 m (3.3 ft) near shore 
to approximately 11 m (35 ft).
BILLING CODE 3510-22-P

[[Page 22455]]

[GRAPHIC] [TIFF OMITTED] TN17MY19.001

BILLING CODE 3510-22-C

Detailed Description of Specific Activity

    The project will involve the removal and replacement of four 
existing 5-pile dolphins and a single 1-pile dolphin with three 4-pile 
dolphins and two 3-pile dolphins. A total of 21 steel pipe piles will 
be removed and 18 steel pipe piles will be installed (Table 1). Piles 
range in size from 20 to 30-inch diameter. Eight piles will be 
installed vertically (plumb) and 10 will be installed at an angle 
(battered). Piles will be advanced to refusal using a vibratory hammer 
and the final approximately 10 ft will be driven using an impact hammer 
so that the structural capacity of the pile embedment can be verified. 
The pile installation methods used will depend on sediment depth and 
conditions at each pile location. ADOT&PF estimates that one to three 
piles could be installed per day. To account for inefficiencies and 
delays, ADOT&PF estimated a mean installation and removal rate of 1.5 
piles per day.

[[Page 22456]]



                         Table 1--Numbers and Types of Piles To Be Installed and Removed
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                                                                   Duration per
Steel pipe pile size and driving     Number of      Strikes per   pile (minutes)   Piles per day      Days of
             method                    piles       pile (impact     (vibratory        (range)        activity
                                                     driving)        driving)
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                                                Pile installation
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30-inch vibratory...............              12             N/A              45       1.5 (1-3)               8
24-inch vibratory...............               6             N/A              45       1.5 (1-3)               4
30-inch impact..................              12             400             N/A       1.5 (1-3)               8
24-inch impact..................               6             400             N/A       1.5 (1-3)               4
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                                                  Pile removal
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30-inch vibratory...............               1             N/A              30             1.5               1
24-inch vibratory...............              12             N/A              30             1.5               8
20-inch vibratory...............               8             N/A              30             1.5               6
                                 -------------------------------------------------------------------------------
    Total piles.................              39  ..............  ..............      Total days              27
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    Above-water work associated with the project will consist of the 
installation of two shore anchor struts above the high tide line. 
Additionally, there will be some improvement and retrofitting to the 
dock-attached stern fenders. New catwalks will be installed for 
pedestrian access to four dolphins while existing catwalks and gangways 
will be re-used for pedestrian access to another dolphin. Existing 
utilities, including electrical and sewer, will be replaced and 
improved. No in-water noise is anticipated in association with above-
water and upland construction activities. Airborne sound is only 
expected to impact pinnipeds that are hauled out in the area where 
sound levels exceed in-air harassment thresholds. No pinniped haulouts 
exist in the project area and no harassment from airborne sound is 
expected to result from project activities. Therefore, above-water 
construction will not be discussed further in this document.
    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's Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS's 
website (https://www.fisheries.noaa.gov/find-species).
    Table 2 lists all species with expected potential for occurrence in 
Auke Bay 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 (2016). PBR is defined by the MMPA as the maximum 
number of animals, not including natural mortalities, that may be 
removed from a marine mammal stock while allowing that stock to reach 
or maintain its optimum sustainable population (as described in NMFS's 
SARs). While no mortality is anticipated or authorized here, PBR and 
annual serious injury and mortality from anthropogenic sources are 
included here as gross indicators of the status of the species and 
other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS's U.S. Alaska and U.S. Pacific SARs. 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; Caretta 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 That Could Occur in the Project Area
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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 Balaenopteridae (rorquals):
    Humpback whale..................  Megaptera novaeangliae.  Central North Pacific..  -/-; Y              10,103 (0.3, 7,890,            83         25
                                                                                                             2006).
    Minke whale.....................  Balaenoptera             Alaska.................  -/-; N              N/A (see SAR, N/A, see        UND          0
                                       acutorostrada.                                                        SAR).

[[Page 22457]]

 
    Fin whale.......................  Balaenoptera physalus..  Northeast Pacific......  E/D; Y              see SAR (see SAR, see         5.1        0.6
                                                                                                             SAR, 2013).
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                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
    Killer whale....................  Orcinus orca...........  Alaska Resident........  -/-; N              2,347 (N/A, 2347,              24          1
                                                                                                             2012).
    Killer whale....................  Orcinus orca...........  Northern Resident......  -/-; N              261 (N/A, 261, 2011)..       1.96          0
    Killer whale....................  Orcinus orca...........  West Coast Transient...  -/-; N              243 (N/A, 243, 2009)..        2.4          0
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena......  Southeast Alaska.......  -/-; Y              975 (0.10; 896; 2012).        8.9         34
    Dall's porpoise.................  Phocoenoides dalli.....  Alaska.................  -/-; N              83,400 (0.097, N/A,           UND         38
                                                                                                             1991).
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                                                         Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
 sea lions):
    Steller sea lion................  Eumetopias jubatus.....  Eastern DPS............  E/D; Y              54,267 (see SAR,              326        252
                                                                                                             54,267, 2017).
    Steller sea lion................  Eumetopias jubatus.....  Western DPS............  -/-; N              41,638 (see SAR,            2,498        108
                                                                                                             41,638, 2015).
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina.........  Lynn Canal/Stephens      -/-; N              9,478 (see SAR, 8,605,        155         50
                                                                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: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
  stock abundance. In some cases, CV is not applicable.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.
Note--Italicized species are not expected to be taken or proposed for authorization.

    All species that could potentially occur in the proposed survey 
areas are included in Table 2. However, the spatial and temporal 
occurrence of gray whales and fin whales in the area is such that take 
is not expected to occur, and they are not discussed further beyond the 
explanation provided here. Sightings of gray whales and fin whales are 
uncommon in the inland waters of southeast Alaska. These species are 
typically seen closer to the open waters of the Gulf of Alaska. 
Additionally, the timing of the project (November through April) 
coincides with the period when these species are expected to be further 
south in their respective breeding areas. Take of gray whales and fin 
whales has not been requested nor is proposed to be authorized and 
these species are not considered further in this document.

Steller Sea Lion

    Steller sea lions are found throughout the northern Pacific Ocean, 
including coastal and inland waters from Russia (Kuril Islands and the 
Sea of Okhotsk), east to Alaska, and south to California. Steller sea 
lions were listed as threatened range-wide under the ESA on November 
26, 1990 (55 FR 49204) but were subsequently partitioned into the 
eastern and western Distinct Population Segments (eDPS and wDPS, 
respectively). The eDPS remained classified as threatened (62 FR 24345; 
May 5, 1997) until it was delisted in 2013 (78 FR 66139; November 4, 
2013). The wDPS (those individuals west of 144[deg] W longitude, or 
Cape Suckling, AK) was upgraded to endangered status following 
separation of the stocks, and it remains listed as endangered.
    Steller sea lions in southeast Alaska are overwhelmingly part of 
the eDPS; however, NMFS (2013) reports that an average of 917 
individuals from the wDPS move into southeast Alaska annually. Within 
southeast Alaska, abundance of wDPS individuals is higher to the north 
and west, and lower toward the south and east. Cape Ommaney and 
Frederick Sound are considered the southern limit of the range for wDPS 
animals. While it is not currently possible to estimate the number of 
wDPS animals that are present east of the 144[deg] W longitude boundary 
at any time, it is assumed that approximately 3.5 percent of Steller 
sea lions present in southeast Alaska are from the wDPS (NMFS 2013), 
though their estimated abundance and distribution throughout southeast 
Alaska vary greatly by location. No wDPS Steller sea lions have been 
documented in Auke Bay. Only three branded wDPS individuals have been 
observed at Benjamin Island, a haulout located approximately 23 km 
(14.3 mi) north-northwest of Auke Bay, and these observations occurred 
more than ten years ago. Surveys conducted by the Alaska Department of 
Fish and Game did not record any branded wDPS individuals at Benjamin 
Island. Although it is unlikely that individuals from the wDPS will be 
harassed by project activities, it is possible. Using branded animal 
ratios, a conservative estimate of 1.6 percent eDPS individuals may 
occur at the Gran Point haulout near Haines, AK based on personal 
communication the applicant had with the Alaska Regional Office. Recent 
IHAs for construction at the Haines Ferry Terminal (83 FR 5063; 
February 5, 2018) and the Statter Harbor Improvement Project (83 FR 
52394; October 17, 2018) conservatively assumed that two percent of 
Steller sea lions observed in these locations are members of the wDPS.
    Steller sea lions are opportunistic predators, feeding primarily on 
a wide variety of fishes and cephalopods,

[[Page 22458]]

including Pacific herring (Clupea pallasi), walleye pollock (Gadus 
chalogramma), capelin (Mallotus villosus), Pacific sand lance 
(Ammodytes hexapterus), Pacific cod (Gadus machrocephalus), salmon 
(Oncorhynchus spp.), and squid (Teuthida spp.) (Jefferson et al., 2008; 
Wynne et al., 2011). Steller sea lions do not generally eat every day, 
but tend to forage every one to two days and return to haulouts to rest 
between foraging trips (Merrick and Loughlin 1997; Rehberg et al., 
2009). Most individuals that frequent Auke Bay haul out at Benjamin 
Island in Lynn Canal, but several other haulouts are located within 20 
to 30 km (12 to 19 mi) of the project area.
    The action area is not located in or near designated critical 
habitat for the wDPS of Steller sea lions. In southeast Alaska, 
critical habitat for the wDPS includes a terrestrial zone, an aquatic 
zone, and an in-air zone that extends 3,000 ft (0.9 km) landward, 
seaward, and above, respectively, any designated major rookery and 
major haulout. The nearest designated major haulout is located at 
Benjamin Island.

Harbor Seal

    Harbor seals range from Baja California north along the west coasts 
of California, Oregon, Washington, 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. Harbor seals occur year-round in the inside passages 
of southeast Alaska and are regularly sighted in Auke Bay, including 
Statter Harbor. Groups ranging from 10 to 52 seals may be present in 
Auke Bay, hauled out on the western side of Coghlan Island and on 
Battleship Island.
    Harbor seals forage on fish and invertebrates, including capelin, 
eulachon (Thaleichthys pacificus), cod, Pollock, flatfish, shrimp, 
octopus, and squid (Wynne 2012). They are opportunistic feeders that 
forage in marine, estuarine, freshwater habitats, adjusting their 
foraging behavior to take advantage of prey that are seasonally and 
locally abundant (Payne and Selzer 1989). Depending on prey 
availability, harbor seals conduct both shallow and deep dives while 
foraging (Tollit et al., 1997). Harbor seals usually give birth to a 
single pup between May and mid-July. Birthing locations are dispersed 
over several haulout sites and are not confined to major rookeries 
(Klinkhart et al., 2008).

Harbor Porpoise

    The Southeast Alaska stock of harbor porpoises ranges from Cape 
Suckling to the Canada border (Muto et al., 2018). Harbor porpoises 
frequent primarily coastal waters in southeast Alaska (Dalheim et al., 
2009) and occur most frequently in waters less than 100 m (328 ft) deep 
(Hobbs and Waite 2010). Harbor porpoises forage in waters less than 200 
m (656 ft) deep on small pelagic schooling fish such as herring, cod, 
pollock, octopus, smelt, and bottom-dwelling fish, occasionally feeding 
on squid and crustaceans (Bj[oslash]rge and Tolley 2009; Wynne et al., 
2011). Calving generally occurs from May to August, but can vary by 
region.

Dall's Porpoise

    Dall's porpoises are found throughout the north Pacific, from 
southern Japan to southern California and north to the Bering Sea. 
Dall's porpoises can be found in offshore, inshore, and nearshore 
habitat, but prefers waters more than 183 m (600 ft) deep (Dahlheim et 
al., 2009; Jefferson 2009). Waters over 183 m (600 ft) do not occur in 
Auke Bay but Dall's porpoises have been consistently observed in Lynn 
Canal, Stephens Passage, upper Chatham Strait, Frederick Sound, and 
Clarence Strait (Dahlheim et al., 2000). Dall's porpoises may migrate 
between inshore and offshore areas and make latitudinal movements or 
short seasonal migrations, but these movements are generally not 
consistent (Jefferson 2009). If Dall's porpoises were to occur in Auke 
Bay, they would likely be present in March or April, given seasonal 
patterns observed in nearby areas of southeast Alaska (Dahlheim et al., 
2009). Dall's porpoises often bow-ride with vessels and may occur in 
Auke Bay incidentally a few times per year.
    Dall's porpoises generally occur in groups of 2 to 20 individuals, 
but have also been recorded in groups numbering in the hundreds. Common 
prey include a variety of small, schooling fishes (such as herring and 
mackerels) and cephalopods.

Killer Whale

    Killer whales have been observed in all oceans, but the highest 
densities occur in colder and more productive waters found at high 
latitudes (NMFS 2016a). Killer whales occur along the entire Alaska 
coast, in British Columbia and Washington inland waterways, and along 
the outer coasts of Washington, Oregon, and California (NMFS 2016a). 
There are three distinct ecotypes, or forms, of killer whales 
recognized in the north Pacific: Resident, transient, and offshore. The 
three ecotypes differ morphologically, ecologically, behaviorally, and 
genetically. Eight stocks of killer whales are recognized within the 
Pacific U.S. Exclusive Economic Zone. Of those, the Alaska Resident 
stock, Northern Resident stock, and West Coast Transient stock may 
occur in the project area (Muto et al., 2018).
    The Alaska Resident stock occurs from southeast Alaska to the 
Aleutian Islands and Bering Sea. Photo-identification studies between 
2005 and 2009 identified 2,347 individuals in this stock, including 
approximately 121 in southeast Alaska (Muto et al., 2018). The Northern 
Resident stock occurs from Washington north through part of southeast 
Alaska and consists of 261 individuals (Muto et al., 2018). The West 
Coast Transient stock occurs from California north through southeast 
Alaska. Between 1975 and 2012, surveys identified 521 individual West 
Coast Transient killer whales but the minimum population estimate for 
the stock is 243 individuals (Muto et al., 2018). Dahlheim et al., 
(2009) noted a 5.2 percent annual decline in transient killer whales 
observed in southeast Alaska between 1991 and 2007.
    No systematic studies of killer whales have been conducted in or 
around Auke Bay. Killer whales were observed infrequently (on 11 of 135 
days) during monitoring in Hoonah, and most were recorded in deeper, 
offshore waters (Berger ABAM 2016). Both resident and transient killer 
whales were observed in southeast Alaska during all seasons during 
surveys between 1991 and 2007, in a variety of habitats and in all 
major waterways, including Lynn Canal, Icy Strait, Stephens Passage, 
Frederick Sound, and upper Chatham Strait (Dahlheim et al., 2009). 
There does not appear to be strong seasonal variation in abundance or 
distribution of killer whales, but Dahlheim et al., (2009) observed 
substantial variability between years during the study.
    Transient killer whales hunt and feed primarily on marine mammals, 
including harbor seals, Dall's porpoises, harbor porpoises, and sea 
lions. Resident killer whale populations in the eastern north Pacific 
feed mainly on salmonids, showing a strong preference for Chinook 
salmon (NMFS 2016a). Transient killer whales are often found in long-
term stable social units (pods) of 1 to 16 whales. Pod sizes in 
southeast Alaska vary by season, averaging 6 animals in spring, 5 in 
summer, and 4 in fall. Group sizes of transient whales are generally 
smaller than those of resident killer whales. Resident killer whales 
occur in pods ranging from

[[Page 22459]]

seven to 70 whales that are seen in association with one another more 
than 50 percent of the time (Dahlheim et al., 2009; NMFS 2016b).

Humpback Whale

    Humpback whales in the project area are from the Central North 
Pacific stock but may be of the Hawaii or Mexico DPS. The population of 
the Hawaii DPS is currently estimated at 11,398 individuals (95% 
confidence interval (CI) = 10,503-12,370) and the Mexico DPS is 
estimated at 3,264 individuals (95% CI = 2,912-3,659). The population 
of humpback whales from both the Hawaii and Mexico DPSs that are found 
in the summer feeding grounds of southeast Alaska is approximately 
6,137 individuals (95% CI = 5,352-7,038) (Wade et al., 2016). Humpback 
whales found in the project area are predominantly members of the 
Hawaii DPS, which is not listed under the ESA. However, based on a 
comprehensive photo-identification study, members of the Mexico DPS, 
which is listed as threatened, are known to occur in southeast Alaska. 
Approximately 6.1 percent (fewer than one in every 16) of all humpback 
whales in southeast Alaska and northern British Columbia are members of 
the Mexico DPS, while all others are assumed to be members of the 
Hawaii DPS (Wade et al., 2016).
    Humpback whales migrate to southeast Alaska in spring to feed after 
months of fasting in equatorial breeding grounds in Hawaii and Mexico. 
Peak abundance of humpback whales in southeast Alaska typically occurs 
during late summer to early fall. Most humpback whales begin returning 
to southern breeding grounds in fall or winter. However, due to 
temporal overlap between whales departing and returning, humpbacks can 
be found in Alaskan feeding grounds in every month of the year (Baker 
et al., 1985; Straley 1990; Wynne and Witteveen 2009). It is also 
common for some humpback whales to overwinter in areas of southeast 
Alaska. It is thought that those humpbacks that remain in southeast 
Alaska do so in response to the availability of winter schools of fish, 
such as herring (Straley 1990).
    The waters of southeast Alaska (including Auke Bay) are considered 
a biologically important area for feeding humpback whales between March 
and November (Ferguson et al., 2015). In Alaska, humpback whales filter 
feed on small crustaceans, plankton, and small fish such as walleye 
pollock, Pacific sand lance, herring, eulachon, and capelin (Witteveen 
et al., 2012). It is common to observe groups of humpback whales 
cooperatively bubble feeding.
    Humpback whales' utilization of Auke Bay is intermittent and 
irregular year-round. Recent anecdotal accounts by the Juneau Deputy 
Harbormaster indicate that humpback whale abundance in Auke Bay has 
been lower over the last 18 months than in past years (Creswell, M., 
pers. comm.). Specific micro-habitat features of Auke Bay attract 
forage fish, specifically herring, and are frequented by humpback 
whales. Although abundance is generally higher in the summer months, 
the presence of prey fish is a greater determinant of the presence of 
humpback whales than season. Teerlink (2017) identified 179 individual 
humpback whales in the Juneau area based on fluke identification.

Minke Whale

    Minke whales are found throughout the northern hemisphere in polar, 
temperate, and tropical waters (Jefferson et al., 2008). The 
International Whaling Commission has identified three minke whale 
stocks in the North Pacific: One near the Sea of Japan, a second in the 
rest of the western Pacific (west of 180[deg] W), and a third, less 
concentrated stock throughout the eastern Pacific. NMFS further splits 
this third stock between Alaska whales and resident whales of 
California, Oregon, and Washington (Muto et al., 2018). Minke whales 
are found in all Alaska waters though there are no population estimates 
for minke whales in southeast Alaska.
    In Alaska, minke whales feed primarily on euphausiids and walleye 
pollock. Minke whales are generally found in shallow, coastal waters 
within 200 m (656 ft) of shore (Zerbini et al., 2006). No information 
appears to be available on the winter occurrence of minke whales in 
southeast Alaska. Anecdotal observations suggest that minke whales do 
not enter Auke Bay, and so are expected to rarely occur in the project 
area.

Marine Mammal Hearing

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

                  Table 3--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
                                               Generalized hearing range
                Hearing group                              *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen whales)  7 Hz to 35 kHz.
Mid-frequency (MF) cetaceans (dolphins,       150 Hz to 160 kHz.
 toothed whales, beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans (true           275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 cephalorhynchid, Lagenorhynchus cruciger &
 L. australis).
Phocid pinnipeds (PW) (underwater) (true      50 Hz to 86 kHz.
 seals).

[[Page 22460]]

 
Otariid pinnipeds (OW) (underwater) (sea      60 Hz to 39 kHz.
 lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
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 survey activities. Please refer to Table 2. Of 
the cetacean species that may be present, two are classified as low-
frequency cetaceans (i.e., all mysticete species), one is classified as 
mid-frequency 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 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. 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 vibratory pile 
removal. 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 sound 
pressure levels (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).
    The likely or possible impacts of ADOT&PF'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.

Acoustic Impacts

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving and removal is the primary means by which 
marine mammals may be harassed from ADOT&PF's specified activity. In 
general, animals exposed to

[[Page 22461]]

natural or anthropogenic sound may experience physical and 
psychological effects, ranging in magnitude from none to severe 
(Southall et al. 2007). In general, exposure to pile driving and 
drilling noise has the potential to result in auditory threshold shifts 
and behavioral reactions (e.g., avoidance, temporary cessation of 
foraging and vocalizing, changes in dive behavior). Exposure to 
anthropogenic noise can also lead to non-observable physiological 
responses such an increase in stress hormones. Additional noise in a 
marine mammal's habitat can mask acoustic cues used by marine mammals 
to carry out daily functions such as communication and predator and 
prey detection. The effects of pile driving and drilling noise on 
marine mammals are dependent on several factors, including, but not 
limited to, sound type (e.g., impulsive vs. non-impulsive), the 
species, age and sex class (e.g., adult male vs. mom with calf), 
duration of exposure, the distance between the pile and the animal, 
received levels, behavior at time of exposure, and previous history 
with exposure (Wartzok et al. 2004; Southall et al. 2007). Here we 
discuss physical auditory effects (threshold shifts) followed by 
behavioral effects and potential impacts on habitat.
    NMFS defines a noise-induced threshold shift (TS) as a change, 
usually an increase, in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). The amount of 
threshold shift is customarily expressed in dB. A TS can be permanent 
or temporary. As described in NMFS (2018), there are numerous factors 
to consider when examining the consequence of TS, including, but not 
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), likelihood an individual would be exposed for a long enough 
duration or to a high enough level to induce a TS, the magnitude of the 
TS, time to recovery (seconds to minutes or hours to days), the 
frequency range of the exposure (i.e., spectral content), the hearing 
and vocalization frequency range of the exposed species relative to the 
signal's frequency spectrum (i.e., how animal uses sound within the 
frequency band of the signal; e.g., Kastelein et al. 2014), and the 
overlap between the animal and the source (e.g., spatial, temporal, and 
spectral).
    Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). Available data from 
humans and other terrestrial mammals indicate that a 40 dB threshold 
shift approximates PTS onset (see Ward et al. 1958, 1959; Ward 1960; 
Kryter et al. 1966; Miller 1974; Ahroon et al. 1996; Henderson et al. 
2008). PTS levels for marine mammals are estimates, as with the 
exception of a single study unintentionally inducing PTS in a harbor 
seal (Kastak et al. 2008), there are no empirical data measuring PTS in 
marine mammals largely due to the fact that, for various ethical 
reasons, experiments involving anthropogenic noise exposure at levels 
inducing PTS are not typically pursued or authorized (NMFS 2018).
    Temporary Threshold Shift (TTS)--A temporary, reversible increase 
in the threshold of audibility at a specified frequency or portion of 
an individual's hearing range above a previously established reference 
level (NMFS 2018). Based on data from cetacean TTS measurements (see 
Southall et al. 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 (2015), 
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 and vibratory pile 
driving. For the project, these activities would not occur at the same 
time and there would likely be pauses in activities producing the sound 
during each day. Given these pauses and that many marine mammals are 
likely moving through the action area and not remaining for extended 
periods of time, the potential for TS declines.
    Behavioral Harassment--Exposure to noise from pile driving and 
removal 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).

[[Page 22462]]

    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, 
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, 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 behavioral 
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 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 projects 
have observed similar behaviors.
    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. Auke 
Bay is home to a busy ferry terminal as well as moorage for small 
private vessels that transit the area on a regular basis; 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 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 exceeding the acoustic thresholds. 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

    ADOT&PF's construction activities could have localized, temporary 
impacts on marine mammal habitat by

[[Page 22463]]

increasing in-water sound pressure levels and slightly decreasing water 
quality. Construction activities are of short duration and would likely 
have temporary impacts on marine mammal habitat through increases in 
underwater sound. 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 
the bay where both fish and mammals may occur and could affect foraging 
success.
    In-water pile driving and pile removal would also cause short-term 
effects on water quality due to increased turbidity. Local currents are 
anticipated to disburse suspended sediments produced by project 
activities at moderate to rapid rates depending on tidal stage. ADOT&PF 
would employ standard construction best management practices, thereby 
reducing any impacts. Considering the nature and duration of the 
effects, combined with the measures to reduce turbidity, 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 the surrounding waters of Lynn 
Canal. Although Auke Bay is included in the designated Biologically 
Important Area for feeding humpback whales (Ferguson et al., 2015), the 
timing of the BIA (March through November) only overlaps with the 
timing of the in-water construction (November through April) for two 
months. Additionally, humpback foraging efforts within Auke Bay itself 
are intermittent and irregular across seasons. Pile installation and 
removal may temporarily increase turbidity resulting from suspended 
sediments. Any increases would be temporary, localized, and minimal. 
ADOT&PF 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 enter the harbor and be close 
enough to the project pile driving areas to experience effects of 
turbidity, and any pinnipeds would likely 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.
    The duration of the construction activities is relatively short, 
with pile driving and removal activities expected to take only 27 days. 
Each day, construction would occur for only a few hours during the day. 
Impacts to habitat and prey are expected to be temporary and 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 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 fish 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 fish 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.
    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 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 vibratory and impact pile hammers has the potential to result in 
disruption of behavioral patterns for individual marine mammals. There 
is also some potential for auditory injury (Level A harassment) to 
result, primarily for high frequency species and phocids because 
predicted auditory injury zones are larger than for other hearing 
groups. Auditory injury is unlikely to occur for other groups. The 
proposed mitigation

[[Page 22464]]

and monitoring measures are expected to minimize the severity of such 
taking to the extent practicable.
    As described previously, no mortality is anticipated or proposed to 
be authorized for this activity. Below we describe how the take is 
estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
and the number of days of activities. We note that while these basic 
factors can contribute to a basic calculation to provide an initial 
prediction of takes, additional information that can qualitatively 
inform take estimates is also sometimes available (e.g., previous 
monitoring results or average group size). Below, we describe the 
factors considered here in more detail and present the proposed take 
estimate.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2012). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 microPascal ([mu]Pa) (root mean square 
(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.
    ADOT&PF's proposed activity includes the use of continuous 
(vibratory pile driving and removal) 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) (Technical Guidance, 2018) identifies dual 
criteria to assess auditory injury (Level A harassment) to five 
different marine mammal groups (based on hearing sensitivity) as a 
result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). ADOT&PF's proposed activity includes the 
use of impulsive (impact pile driving) and non-impulsive (vibratory 
pile driving and removal) sources.
    These thresholds are provided in the Table 4. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                                         Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                        PTS onset acoustic thresholds \*\ (received level)
              Hearing group              ---------------------------------------------------------------------------------------------------------------
                                                                      Impulsive                                             Non-impulsive
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans............  Cell 1: Lpk,flat: 219 dB; LE,LF,24h: 183 dB.....................  Cell 2: LE,LF,24h: 199 dB.
Mid-Frequency (MF) Cetaceans............  Cell 3: Lpk,flat: 230 dB; LE,MF,24h: 185 dB.....................  Cell 4: LE,MF,24h: 198 dB.
High-Frequency (HF) Cetaceans...........  Cell 5: Lpk,flat: 202 dB; LE,HF,24h: 155 dB.....................  Cell 6: LE,HF,24h: 173 dB.
Phocid Pinnipeds (PW) (Underwater)......  Cell 7: Lpk,flat: 218 dB; LE,PW,24h: 185 dB.....................  Cell 8: LE,PW,24h: 201 dB.
Otariid Pinnipeds (OW) (Underwater).....  Cell 9: Lpk,flat: 232 dB; LE,OW,24h: 203 dB.....................  Cell 10: LE,OW,24h: 219 dB.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for calculating PTS onset. If a non-impulsive
  sound has the potential of exceeding the peak sound pressure level thresholds associated with impulsive sounds, these thresholds should also be
  considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE) has a reference value of 1[micro]Pa\2\s.
  In this Table, thresholds are abbreviated to reflect American National Standards Institute standards (ANSI 2013). However, peak sound pressure is
  defined by ANSI as incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is being
  included to indicate peak sound pressure should be flat weighted or unweighted within the generalized hearing range. The subscript associated with
  cumulative sound exposure level thresholds indicates the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW
  pinnipeds) and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be exceeded in a multitude
  of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it is valuable for action proponents to indicate the conditions
  under which these acoustic thresholds will be exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional 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). The maximum (underwater) area ensonified 
above the thresholds for behavioral harassment referenced above is 22.5 
km\2\ (8.69 mi\2\), and is governed by the topography of Auke Bay and 
the various islands located within and around the bay. The eastern part 
of Auke Bay is acoustically shadowed by Auke Cape, while Portland 
Island, Coghlan Island, Suedla Island, and Spuhn Island would inhibit 
sound transmission from reaching the more open waters toward Mansfield 
Peninsula (see Figure 6-2 in the IHA application). Additionally,

[[Page 22465]]

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.
    The project includes vibratory and impact pile installation of 
steel pipe piles and vibratory removal of steel pipe piles. Source 
levels of pile installation and removal activities are based on reviews 
of measurements of the same or similar types and dimensions of piles 
available in the literature, including past pile driving activities in 
Auke Bay. Source levels for each pile size and driving method are 
presented in Table 5. The source level for vibratory installation of 
24-inch piles and vibratory removal of 24-inch and 20-inch piles are 
from measurements of 24-inch steel piles driven at Navy installations 
in Puget Sound, Washington (United States Navy 2015). As there are no 
measurements of source levels for these pile types in Alaska, we use 
the Navy's source levels as a proxy. The vibratory and impact source 
levels for 30-inch pile installation is from pile driving activities at 
the Auke Bay ferry terminal in November 2015 (Denes et al., 2016). The 
source level for impact installation of 24-inch piles is based on the 
averaged source level of the same type of pile reported by California 
Department of Transportation (Caltrans) in a pile driving source level 
compendium document (Caltrans 2015). Source levels for vibratory 
installation and removal of piles of the same diameter are assumed to 
be the same.

                                             Table 5--Sound Source Levels for Pile Sizes and Driving Methods
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Source level
               Pile size                           Method          ------------------------------------------------           Literature source
                                                                        dB RMS        dB SEL \a\        dB peak
--------------------------------------------------------------------------------------------------------------------------------------------------------
20-inch................................  vibratory................         \b\ 161             N/A             N/A  Navy 2015.
24-inch................................  vibratory................             161             N/A             N/A  Navy 2015.
24-inch................................  impact...................             190             177             203  Caltrans 2015.
30-inch................................  vibratory................             168             N/A             N/A  Denes et al. 2016.
30-inch................................  impact...................             191             177             206  Denes et al. 2016.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Sound exposure level (dB re 1 [mu]Pa\2\-sec).
\b\ Source level data for 20-inch piles are not available. Source levels for 20-inch piles are conservatively assumed to be the same as 24-inch piles.

    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/R 2),

where
TL = transmission loss in dB
B = transmission loss coefficient
R1 = the distance of the modeled SPL from the driven 
pile, and
R2 = the distance from the driven pile of the initial 
measurement

    Absent site-specific acoustical monitoring with differing measured 
transmission loss, a practical spreading value of 15 is used as the 
transmission loss coefficient in the above formula. For vibratory and 
impact pile driving of 30-inch piles at the Auke Bay ferry terminal, 
Denes et al., (2016) measured transmission loss that differed slightly 
from the standard practical value of 15. The transmission loss 
coefficient for vibratory driving of 30-inch piles was determined to be 
16.4 while the coefficient for impact driving of 30-inch piles was 
determined to be 14.6. These transmission loss coefficients were used 
to calculate the Level A and Level B harassment zones for 30-inch 
piles. Site-specific transmission loss data for 20- and 24-inch piles 
are not available, therefore the default coefficient of 15 is used for 
these pile sizes to determine the distances to the Level A and Level B 
harassment thresholds.

                                   Table 6--Pile Driving Source Levels and Distances to Level B Harassment Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                              Level B
                                                                     Source level at   Level B threshold    Propagation     Distance to     harassment
                       Pile size and method                           10 m (dB re 1         (dB re 1          (xLogR)         Level B       ensonified
                                                                      [micro]Pa rms)     [micro]Pa rms)                    threshold (m)   area (km\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
20-inch vibratory.................................................                161                120              15           5,412            15.3
24-inch vibratory.................................................                161                120              15           5,412            15.3
24-inch impact....................................................                190                160              15           1,000             1.5
30-inch vibratory.................................................                168                120            16.4           8,449            22.5
30-inch impact....................................................                191                160            14.6           1,328             2.3
--------------------------------------------------------------------------------------------------------------------------------------------------------

    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 
drivers), NMFS User Spreadsheet predicts the closest distance at which, 
if a marine mammal remained at that distance the whole

[[Page 22466]]

duration of the activity, it would not incur PTS. Inputs used in the 
User Spreadsheet (Table 7), and the resulting isopleths are reported 
below (Table 8).

                              Table 7--User Spreadsheet Input Parameters Used for Calculating Level A Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Weighting
                                                             factor                                                 Number of    Number of     Activity
 Pile size and installation method  Spreadsheet tab used   adjustment  Source level at 10 m   Propagation (xLogR)  strikes per   piles per     duration
                                                             (kHz)                                                     pile         day       (seconds)
--------------------------------------------------------------------------------------------------------------------------------------------------------
20-inch and 24-inch Vibratory       (A.1) Vibratory pile          2.5  161 dB rms..........  15LogR..............  ...........            3        5,400
 Removal.                            driving.
30-inch Vibratory Removal.........  (A.1) Vibratory pile          2.5  168 dB rms..........  16.4LogR............  ...........            3        5,400
                                     driving.
24-inch Vibratory Installation....  (A.1) Vibratory pile          2.5  161 dB rms..........  15LogR..............  ...........            3        8,100
                                     driving.
30-inch Vibratory Installation....  (A.1) Vibratory pile          2.5  168 dB rms..........  16.4LogR............  ...........            3        8,100
                                     driving.
24-inch Impact Installation.......  (E.1) Impact pile               2  177 dB SEL..........  15LogR..............          400      \a\ 1-3
                                     driving.
30-inch Impact Installation.......  (E.1) Impact pile               2  177 dB SEL..........  14.6LogR............          400      \a\ 1-3
                                     driving.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ To account for potential variations in daily productivity during impact installation, isopleths were calculated for different numbers of piles that
  could be installed per day (Table 1).


                          Table 8--Calculated Distances to Level A Harassment Isopleths
----------------------------------------------------------------------------------------------------------------
                                                            Level A harassment zone (m)
            Activity             -------------------------------------------------------------------------------
                                   LF-cetaceans    MF-cetaceans    HF-cetaceans       Phocids        Otariids
----------------------------------------------------------------------------------------------------------------
20-inch and 24-inch Vibratory                  9               1              14               6               1
 Removal........................
30-inch Vibratory Removal.......              25               3              25              16               2
24-inch Vibratory Installation..              12               1              18               8               1
30-inch Vibratory Installation..              31               4              45              20               2
24-inch Impact Installation (3               449              16             535             241              18
 piles per day).................
24-inch Impact Installation (2               343              13             409             184              14
 piles per day).................
24-inch Impact Installation (1               216               8             258             116               9
 pile per day)..................
30-inch Impact Installation (3               499              17             597             263              18
 piles per day).................
30-inch Impact Installation (2               378              13             452             199              14
 piles per day).................
30-inch Impact Installation (1               235               8             281             124               9
 pile per day)..................
----------------------------------------------------------------------------------------------------------------

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 and describe how it is 
brought together with the information above to produce a quantitative 
take estimate. When available, peer-reviewed scientific publications 
were used to estimate marine mammal abundance in the project area. 
However, scientific surveys and resulting data such as population 
estimates, densities, and other quantitative information are lacking 
for most marine mammal populations and most areas of southeast Alaska, 
including Auke Bay. Therefore, AKDOT&PF gathered qualitative 
information from discussions with knowledgeable local people in the 
Auke Bay area, including biologists, the harbormaster, a tour operator, 
and other individuals familiar with marine mammals in the Auke Bay 
area.
    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate. Because reliable 
densities are not available, the applicant requests take based on the 
maximum number of animals that may occur in the harbor per day 
multiplied by the number of days of the activity.

Steller Sea Lion

    Steller sea lions are common within Auke Bay but generally only 
occur in the area during winter. Most individuals that frequent Auke 
Bay haul out at Benjamin Island in Lynn Canal. The Auke Bay boating 
community observes Steller sea lions transiting between Auke Bay and 
Benjamin Island regularly during winter. Steller sea lions are not 
known to haul out on any beaches or structures within Auke Bay, but 
animals have been observed foraging within Auke Bay, and may rest in 
large raft groups in the water. Groups as large as 121 individuals have 
been observed in Auke Bay (Ridgway pers. observ.).
    ADOT&PF estimates that one large group (121 individuals) may be 
exposed to project-related underwater noise daily on 27 days of pile 
installation and removal activities, for a total of 3,267 exposures. As 
stated above, only two percent of Steller sea lions present in Auke Bay 
are expected to belong to the wDPS, for a total of 66 exposures of wDPS 
Steller sea lions and 3,201 exposures of eDPS Steller sea lions.
    The largest Level A harassment zone for otariid pinnipeds extends 
18 m from the source (Table 7). ADOT&PF is planning to implement a 
minimum 20 m shutdown zone during all pile installation and removal 
activities (see Proposed Mitigation section), which is expected to 
eliminate the potential for Level A take of Steller sea lions. 
Therefore, no takes of Steller sea lions by Level A harassment were 
requested or are proposed to be authorized.

Harbor Seal

    Harbor seals are commonly sighted in the waters of the inside 
passages throughout southeast Alaska. Seals occur year-round within the 
project area and are regularly sighted in Auke Bay, including Statter 
Harbor. NOAA aerial survey data indicate that groups ranging from 10 to 
52 seals could be present within the project area during summer at 
haulouts on the western side of Coghlan Island, as well as on 
Battleship Island (Ridgway unpubl. data).
    Harbor seals are known to haul out within the Level B harassment 
zones and may be exposed to noise levels in excess of the Level B 
harassment thresholds upon entering the water. ADOT&PF estimates up to 
52 harbor seals could be exposed to elevated sound levels on each day 
of pile driving, for a total of 1,404 exposures.
    The largest Level A harassment zone for phocid pinnipeds results 
from impact pile driving of 30-inch piles and extends 263 m from the 
source (Table 7). There are no haulouts located within

[[Page 22467]]

the Level A harassment zone and although it is unlikely that harbor 
seals will enter this area without detection while pile driving 
activities are underway, it is possible that harbor seals may approach 
and enter the Level A harassment zone undetected. ADOT&PF estimated 
that up to 11 harbor seals may approach the site within 263 m of the 
source each day. Impact pile driving may occur on up to 12 days (Table 
1). For this reason, ADOT&PF has requested Level A take of 11 harbor 
seals daily on the 12 days of impact pile driving for a total of 132 
takes by Level A harassment. The largest Level A harassment zone for 
phocid pinnipeds from vibratory pile driving extends 20 m from the 
source (Table 7). ADOT&PF is planning to implement a minimum 20 m 
shutdown zone during all pile installation and removal activities (see 
Proposed Mitigation section), which is expected to eliminate the 
potential for Level A harassment of harbor seals from vibratory pile 
driving.

Harbor Porpoise

    Although there have been no systematic studies or observations of 
harbor porpoises specific to Auke Bay, there is the potential for them 
to occur within the project area. Abundance data for harbor porpoises 
in southeast Alaska were collected during 18 seasonal surveys spanning 
22 years, from 1991 to 2012. During that study, a total of 398 harbor 
porpoises were observed in the northern inland waters of southeast 
Alaska, including Lynn Canal (Dahlheim et al., 2015). Mean group size 
of harbor porpoises in southeast Alaska varies by season. In the fall, 
mean group size was determined to be 1.88 harbor porpoises (Dahlheim et 
al., 2009). ADOT&PF has conservatively assumed that one pair of harbor 
porpoises may be present in Auke Bay per day.
    One pair of harbor porpoises per day could enter the Level B 
harassment zone for a total of 54 exposures. The largest Level A 
harassment zone results from impact driving of 30-inch piles, and 
extends 597 m from the source (Table 7). Impact pile driving may occur 
on up to 12 days (Table 1). ADOT&PF will implement a shutdown zone for 
harbor porpoises that encompasses the largest Level A harassment zone 
(see Proposed Mitigation section). However, harbor porpoises are known 
to be an inconspicuous species and are challenging for protected 
species observers (PSOs) to sight, making any approach to a specific 
area potentially difficult to detect. Because harbor porpoises move 
quickly and elusively, it is possible that they may enter the Level A 
harassment zone without detection. ADOT&PF has estimated that one pair 
of harbor porpoises may enter the Level A harassment zone every other 
day over the 12 days of impact pile driving, which is used to 
conservatively predict a total of 12 exposures to Level A harassment. 
The largest Level A harassment zone for high-frequency cetaceans from 
vibratory pile driving is 45 m. ADOT&PF is planning to implement a 
minimum 50 m shutdown zone for all cetacean species during vibratory 
pile installation and removal activities (see Proposed Mitigation 
section), which is expected to eliminate the potential for Level A 
harassment of harbor porpoises from vibratory pile driving.

Dall's Porpoise

    Dall's porpoises are not expected to occur within Auke Bay because 
the shallow water habitat of the bay is atypical of areas where Dall's 
porpoises usually occur. However, Dall's porpoises may 
opportunistically inhabit nearshore habitat, especially in spring. 
Therefore, ADOT&PF estimated that one large pod of Dall's porpoise (15 
individuals) may occur within the Level B harassment zone once per 
month in the months of March and April, for a total of 30 takes by 
Level B harassment.
    ADOT&PF will implement shutdown zones for porpoises that encompass 
the largest Level A harassment zones for each pile driving activity 
(see Proposed Mitigation section). The largest Level A harassment zone 
for Dall's porpoise extends 597 m from the source during impact 
installation of 30-inch piles (Table 7). Given the larger group size 
and more conspicuous rooster-tail generated by swimming Dall's 
porpoises, which makes them more noticeable than harbor porpoises, PSOs 
are expected to detect Dall's porpoises prior to them entering the 
Level A harassment zone. Therefore, takes of Dall's porpoises by Level 
A harassment have not been requested and are not proposed to be 
authorized.

Killer Whale

    Killer whales are observed occasionally during summer throughout 
Lynn Canal but their presence in Auke Bay is unlikely. As a precaution, 
because Level B harassment zones extend beyond the more enclosed waters 
of Auke Bay, AKDOT&PF has estimated that one pod of killer whales (15 
individuals) may enter the Level B harassment zone once over the course 
of the project for a total of 15 takes by Level B harassment.
    ADOT&PF will implement shutdown zones that encompass the largest 
Level A harassment zones for killer whales during all pile driving 
activities. Killer whales are generally conspicuous and PSOs are 
expected to detect killer whales and implement a shutdown before the 
animals enter the Level A harassment zone. Therefore, takes by Level A 
harassment have not been requested and are not proposed to be 
authorized.

Humpback Whale

    Use of Auke Bay by humpback whales is intermittent and irregular 
year-round. During winter, researchers have documented 1 to 19 
individual humpback whales per month in waters close to the project 
area, including Lynn Canal (Moran et al., 2018a; Straley et al., 2018). 
Group sizes in southeast Alaska generally range from one to four 
individuals (Dahlheim et al., 2009). Based on observations of humpback 
whales within Auke Bay during winter, ADOT&PF estimates that one group 
of up to four individuals may be exposed to project-related underwater 
sound each day during the 27 days of pile driving activities, for a 
total of 108 takes by Level B harassment.
    The largest Level A harassment zone for humpback whales extends 499 
m from the source during impact installation of 30-inch piles (Table 
7). Given the irregular and small presence of humpback whales in Auke 
Bay, along with the fact that PSOs are expected to detect humpback 
whales before they enter the Level A harassment zone and implement 
shutdowns to prevent take by Level A harassment, no Level A takes have 
been requested nor proposed to be authorized.

Minke Whale

    Dedicated surveys for cetaceans in southeast Alaska found that 
minke whales were scattered throughout inland waters from Glacier Bay 
and Icy Strait to Clarence Strait, with small concentrations near the 
entrance of Glacier Bay. All sightings were of single minke whales, 
except for a single sighting of multiple minke whales. Surveys took 
place in spring, summer, and fall, and minke whales were present in low 
numbers in all seasons and years (Dahlheim et al., 2009). Anecdotal 
reports have not included minke whales near Auke Bay. However, minke 
whales are distributed throughout a wide variety of habitats and have 
been observed in nearby Glacier Bay, indicating they may potentially 
occur within the Level B harassment zone. Therefore, ADOT&PF estimates 
that one minke whale per month may enter the Level B harassment zone 
over the course of pile driving activities, for a total of six takes by 
Level B harassment.

[[Page 22468]]

    The Level A harassment zones for minke whales are the same as for 
humpback whales, and the shutdown protocols will be the same as well. 
Therefore, given the low occurrence of minke whales combined with the 
mitigation, takes by Level A harassment have not been requested and are 
not proposed to be authorized.

                                     Table 9--Estimated Take by Level A and Level B Harassment, by Species and Stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                           Proposed take
                Common name                             Stock                  Stock          Level A         Level B     Total proposed   as percentage
                                                                           abundance \a\                                       take          of stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale............................  Central North Pacific.......          10,103               0         108 \b\             108            1.06
Minke Whale...............................  Alaska......................             N/A               0               6               6             N/A
Killer whale..............................  Alaska Resident.............           2,347               0              15              15        0.64 \d\
                                            Northern Resident...........             261                                                        5.75 \d\
                                            West Coast Transient........             243                                                        6.17 \d\
Harbor porpoise...........................  Southeast Alaska............             975              12              42              54            5.54
Dall's porpoise...........................  Alaska......................          83,400               0              30              30            <0.1
Steller sea lion..........................  Western U.S.................          54,267               0              66          66 \c\            0.12
                                            Eastern U.S.................          41,638               0           3,201           3,201            7.69
Harbor seal...............................  Lynn Canal/Stephens Passage.           9,478             132           1,272           1,404            14.8
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Stock or DPS size is Nbest according to NMFS 2018 Draft Stock Assessment Reports.
\b\ 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 7 Level B takes to the Mexico DPS.
\c\ 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.
\d\ These percentages assume all 15 takes may occur to each individual stock, thus the percentage of one or more stocks are likely inflated as the takes
  would be divided among multiple stocks.

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, 
ADOT&PF 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 ADOT&PF's mitigation 
requirements:
    Establishment of Shutdown Zone for Level A Harassment--For all pile 
driving/removal and drilling activities, ADOT&PF 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). These shutdown zones would be used to prevent incidental Level A 
exposures from impact pile driving for Steller sea lions, Dall's 
porpoises, killer whales, humpback whales, and minke whales, and to 
reduce the potential for such take for harbor seals and harbor 
porpoises. During all pile driving and removal activities, a minimum 
shutdown zone of 20 m would be enforced (Table 10).

[[Page 22469]]

During vibratory pile driving and removal activities, ADOT&PF would 
enforce a 50 m shutdown zone for all cetacean species (Table 10). 
Shutdown zones for impact pile driving activities are based on the 
Level A harassment zones and therefore vary by pile size, number of 
piles installed per day, and marine mammal hearing group (Table 10). 
Shutdown zones for impact pile driving will be established each day for 
the greatest number of piles that are expected to be installed that 
day. If no marine mammals enter their respective Level A harassment 
zones during impact installation of the first pile of the day, the 
shutdown zone for the next pile that same day will be smaller (e.g., 
the shutdown zone for a three-pile day will be reduced in size to the 
shutdown zone for a two-pile day for the second pile). Shutdown zones 
will be further reduced to those for a one-pile day for the third pile 
of the day, as long as no marine mammals have been exposed to noise 
levels exceeding the Level A harassment thresholds that day. 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.

                                              Table 10--Shutdown Zones During Pile Installation and Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                         Shutdown zone (m)
                        Activity                           Piles per day -------------------------------------------------------------------------------
                                                                           LF cetaceans    MF cetaceans    HF cetaceans       Phocids        Otariids
--------------------------------------------------------------------------------------------------------------------------------------------------------
All vibratory installation and removal..................               3                        50
                                                                        20
--------------------------------------------------------------------------------------------------------------------------------------------------------
30-inch pile impact installation........................               3             500        20                   600             270        20
                                                                       2             380                             460             200
                                                                       1             250                             290             130
24-inch pile impact installation........................               3             450                             550             250
                                                                       2             350                             410             200
                                                                       1             220                             260             120
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Establishment of Monitoring Zones for Level B Harassment--ADOT&PF 
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 11. Placement of PSOs 
on the shorelines around Auke Bay allow PSOs to observe marine mammals 
within and near Auke Bay. 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.

                Table 11--Marine Mammal Monitoring Zones
------------------------------------------------------------------------
                                                            Monitoring
                        Activity                             zone (m)
------------------------------------------------------------------------
20-inch vibratory removal...............................           5,415
24-inch vibratory removal and installation.
24-inch impact installation.............................           1,000
30-inch vibratory installation..........................           8,450
30-inch impact installation.............................           1,330
------------------------------------------------------------------------

    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.
    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

[[Page 22470]]

the necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); 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.
    At least two land-based PSOs will be on duty during all pile 
installation and removal activities. One PSO will be positioned at the 
ferry terminal to allow full monitoring of the waters within the 
shutdown zones and the closest waters of the Level B harassment 
monitoring zones. An additional PSO will be positioned on the shoreline 
around Auke Bay to observe the larger monitoring zones. Potential PSO 
locations are shown in Figure 2-2 of ADOT&PF's 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. ADOT&PF 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; and
    (iv) ADOT&PF must 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,

[[Page 22471]]

ADOT&PF would immediately cease the specified activities and report the 
incident to the Chief of the Permits and Conservation Division, Office 
of Protected Resources, NMFS, and the Alaska Regional Stranding 
Coordinator. The report 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 ADOT&PF to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. ADOT&PF would not be able 
to resume their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that ADOT&PF 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), 
ADOT&PF 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 ADOT&PF to determine whether modifications in the 
activities are appropriate.
    In the event that ADOT&PF 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), ADOT&PF 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. ADOT&PF would provide photographs, video footage (if 
available), or other documentation of the stranded animal sighting to 
NMFS and the Marine Mammal Stranding Network.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    Pile driving/removal and drilling activities associated with the 
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. Potential takes could occur if individuals of these species 
are present in zones ensonified above the thresholds for Leval A or 
Level B harassment identified above 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 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).
    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 for pile 
driving, individuals will simply move away from the sound source and be 
temporarily displaced from the areas of pile driving and drilling, 
although even this reaction has been observed primarily only in 
association with impact pile driving. The pile driving activities 
analyzed here are similar to, or less impactful than, numerous other 
construction activities conducted in southeast Alaska, which 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 harbor 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

[[Page 22472]]

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.
    Nearly all inland waters of southeast Alaska, including Auke Bay, 
are included in the southeast Alaska humpback whale feeding BIA 
(Ferguson et al., 2015), though humpback whale distribution in 
southeast Alaska varies by season and waterway (Dahlheim et al. 2009). 
Humpback whales are present within Auke Bay intermittently and in low 
numbers. The area of the BIA that may be affected by the proposed 
project is small relative to the overall area of the BIA, and the area 
of suitable humpback whale habitat that is not included in the BIA. The 
southeast Alaska humpback whale feeding BIA is active between March and 
November while the proposed project is scheduled to occur between 
November and March, resulting in only two months of overlap. 
Additionally, pile driving associated with the project is expected to 
take only 27 days, further reducing the temporal overlap with the BIA. 
Therefore, the proposed project is not expected to have significant 
adverse effects on the southeast Alaska humpback whale feeding BIA.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect the species or stock 
through effects on annual rates of recruitment or survival:
    No mortality is anticipated or authorized;
     The Level A harassment exposures are anticipated to result 
only in slight PTS, within the lower frequencies associated with pile 
driving;
     The anticipated incidents of Level B harassment would 
consist of, at worst, temporary modifications in behavior that would 
not result in fitness impacts to individuals;
     The area impacted by the specified activity is very small 
relative to the overall habitat ranges of all species, does not include 
ESA-designated critical habitat, and only temporally overlaps with the 
southeast Alaska humpback whale feeding BIA for two months of the 
planned six months of activity; and
     The proposed mitigation measures are expected to reduce 
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 8 demonstrates the number of animals that could be exposed to 
received noise levels that could cause Level A and Level B harassment 
for the proposed work in Auke Bay. Our analysis shows that less than 15 
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.
    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. 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. The 
proposed project is not known to occur in an important subsistence 
hunting area. It is a developed area with regular marine vessel 
traffic. However, ADOT&PF plans to provide advanced public notice of 
construction activities to reduce construction impacts on local 
residents, ferry travelers, adjacent businesses, and other users of the 
Auke Bay ferry terminal and nearby areas. This will include 
notification to local Alaska Native tribes that may have members who 
hunt marine mammals for subsistence. Of the marine mammals considered 
in this IHA application, only harbor seals are known to be used for 
subsistence in the project area. If any tribes express concerns 
regarding project impacts to subsistence hunting of marine mammals, 
further communication between will take place, including provision of 
any project information, and clarification of any mitigation and 
minimization measures that may reduce potential impacts to marine 
mammals.
    Based on the description of the specified activity, the measures 
described to minimize adverse effects on the availability of marine 
mammals for subsistence purposes, and the proposed mitigation and 
monitoring measures, NMFS has preliminarily determined that there will 
not be an unmitigable adverse impact on subsistence uses from ADOT&PF's 
proposed activities.

[[Page 22473]]

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally, in this case with the Alaska Regional Office, 
whenever we propose to authorize take for endangered or threatened 
species.
    NMFS is proposing to authorize take of wDPS Steller sea lions and 
Mexico DPS humpback whales, which are listed under the ESA. The Permit 
and Conservation Division has requested initiation of section 7 
consultation with NMFS' 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 ADOT&PF for conducting pile installation and removal 
activities at the Auke Bay ferry terminal between November 2019 and 
April 2020, provided the previously mentioned mitigation, monitoring, 
and reporting requirements are incorporated. A draft of the proposed 
IHA can be found at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this Notice of Proposed IHA for the proposed 
[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 one-year IHA renewal with 
an expedited public comment period (15 days) 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 under the 
proposed Renewal are identical to the activities analyzed under the 
initial IHA, are a subset of the activities, or include changes so 
minor (e.g., reduction in pile size) that the changes do not affect the 
previous analyses, mitigation and monitoring requirements, or take 
estimates (with the exception of reducing the type or amount of take 
because only a subset of the initially analyzed activities remain to be 
completed under the Renewal); and
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized.
     Upon review of the request for renewal, the status of the 
affected species or stocks, and any other pertinent information, NMFS 
determines that there are no more than minor changes in the activities, 
the mitigation and monitoring measures will remain the same and 
appropriate, and the findings in the initial IHA remain valid.

    Dated: May 13, 2019.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2019-10326 Filed 5-16-19; 8:45 am]
 BILLING CODE 3510-22-P