Takes of Marine Mammals Incidental To Specified Activities; Taking Marine Mammals Incidental to Washington State Department of Transportation Purdy Bridge Rehabilitation Project, Pierce County, WA, 81886-81904 [2020-27787]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 85, Number 243 (Thursday, December 17, 2020)]
[Notices]
[Pages 81886-81904]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-27787]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XA694]


Takes of Marine Mammals Incidental To Specified Activities; 
Taking Marine Mammals Incidental to Washington State Department of 
Transportation Purdy Bridge Rehabilitation Project, Pierce County, WA

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 Washington State 
Department of Transportation (WADOT) for authorization to take marine 
mammals incidental to the Purdy Bridge

[[Page 81887]]

Rehabilitation Project in Pierce County, WA. Pursuant to the Marine 
Mammal Protection Act (MMPA), NMFS is requesting comments on its 
proposal to issue an incidental harassment authorization (IHA) to 
incidentally take marine mammals during the specified activities. NMFS 
is also requesting comments on a possible one-year renewal that could 
be issued under certain circumstances and if all requirements are met, 
as described in Request for Public Comments at the end of this notice. 
NMFS will consider public comments prior to making any final decision 
on the issuance of the requested MMPA authorizations and agency 
responses will be summarized in the final notice of our decision.

DATES: Comments and information must be received no later than January 
19, 2021.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. 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:  Dwayne Meadows, Ph.D., 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 availability of the species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of the takings are set forth.
    The definitions of all applicable MMPA statutory terms cited above 
are included in the relevant sections below.

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 IHA) 
with respect to potential impacts on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs 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 July 27, 2020, NMFS received an application from WADOT 
requesting an IHA to take small numbers of six species of marine 
mammals incidental to pile driving and removal associated with the 
Purdy Bridge Rehabilitation Project. The application was deemed 
adequate and complete on December 1, 2020. WADOT's request is for take 
of a small number of each species by Level B harassment. Neither WADOT 
nor NMFS expects serious injury or mortality to result from this 
activity and, therefore, an IHA is appropriate.

Description of Proposed Activity

Overview

    The purpose of the project is to rehabilitate the two in-water 
support piers of the State Route 302 Purdy Bridge by removing the top 3 
inches (7.5 centimeter (cm)) of decaying concrete on each support pier 
and replacing with fiberglass reinforced concrete. Twenty steel H piles 
and 44 sheetpiles will be driven to create a caisson-like dewatered 
structures around the bridge piers to allow the work to be completed. 
Once the work on the piers is completed the piles will be removed. A 
needle gun will be used to remove 3 inches (7.5 cm) of decayed concrete 
from the two in-water bridge piers. Pile driving/removal and concrete 
removal is expected to take no more than 20 days. Pile driving/removal 
would be by vibratory pile driving.
    The pile driving/removal can result in take of marine mammals from 
sound in the water which results in behavioral harassment or auditory 
injury. Needle gun scraping from sound in the air may result in 
behavioral harassment of pinnipeds.

Dates and Duration

    The work described here is scheduled for July 16, 2021 through 
February 15, 2022 as it is limited to this work window because of 
restrictions to protect ESA-listed salmonids. In-water activities will 
occur during daylight hours only.

Specific Geographic Region

    The activities would occur in Henderson Bay, a small isolated bat 
of south Puget Sound near the unincorporated community of Purdy, WA, 
north of the city of Gig Harbor, WA

[[Page 81888]]

(Figure 1). The Bay is oriented basically north-south with the Purdy 
Bridge spanning the bay where a sand spit narrows the width of the bay 
near its northern limit. North of the bridge is the Burley Lagoon, a 
1.45 square kilometer (km\2\) (0.56 square miles (mi\2\)) shallow water 
lagoon with significant acreage used for commercial shellfishing. The 
width of Henderson Bay ranges from 0.3 to 5.8 kilometer (km) (0.2 to 
3.6 miles (mi)), and depths range from 23 meter (m) (74 feet (ft)) Mean 
Lower Low Water (MLLW) to intertidal. Water depths near the bridge vary 
from exposed substrate at low tides to 5 m (15 ft) at high tide. The 
substrate in the area is gravels in a sand matrix which do not require 
impact pile driving.

Detailed Description of Specific Activity

    Purdy Bridge is a continuous hollow-box girder bridge that is 170 m 
(550 ft) long and was built in 1937. It is two lanes wide and supported 
by four piers, two of which are in the water and will be repaired as 
part of this project. These two piers are 190 feet apart and seriously 
decayed. The purpose of the project is to rehabilitate the two in-water 
support piers by removing the top 3 inches (7.5 cm) of decaying 
concrete on each support pier and replacing with fiberglass reinforced 
concrete. Twenty steel H piles and 44 sheetpiles will be driven with a 
vibratory hammer to create a caisson-like dewatered structures around 
the bridge piers to allow the work to be completed.
BILLING CODE 3510-22-P
[GRAPHIC] [TIFF OMITTED] TN17DE20.068


[[Page 81889]]


BILLING CODE 3510-22-C
    Areas immediately surrounding the pier footings will be excavated 
to expose the footings and provide a stable base for any cofferdam 
system that may be required. The excavated area will be approximately 
40 square m (430 square ft) for each pier column, based on a 1.5 m (5 
ft) pad around the pier footing. Around each pier, 10 12-inch steel H 
piles will be installed with a vibratory hammer. Additional H piles 
will then be tacked horizontally (not hammered) onto the vertical H 
piles above the water level to create a flat supportive surface 
template to align the sheet piles. Using this template as a guide, 22 
48-inch sheet piles will be driven with a vibratory hammer into the 
substrate immediately adjacent to each pier to form a temporary 
interlocked sheet pile wall to isolate the work area from the 
surrounding water.
    Once these structures are in place, the rest of the containment 
system will be installed prior to removing marine growth and preparing 
the piers for repair. The pier columns will then be pressure washed to 
remove all existing marine growth. Next, the exposed concrete surface 
of each pier will be prepared by removing approximately 3 inches (7.5 
cm) of the concrete on all four sides of the columns with a needle gun. 
Any potentially contaminated water from these procedures will be 
removed from the containment system and treated. Finally, the columns 
will be repaired with the placement of corrosion resistant fiberglass 
reinforcement. Forms will be installed and approximately 6 inches (15 
cm) of concrete or grout will be placed to encapsulate the fiberglass 
reinforcement. A pigmented sealer will then be applied to all surfaces 
of the pier columns. Once the pier columns are repaired, the 
containment system will be removed, including vibratory pile removal to 
remove the H piles and sheetpiles. The earth removed around each column 
will be allowed to fill back naturally as part of the tidal process.
    Pile driving/removal is expected to take no more than 14 days 
total; 9 days to install the containment system at the beginning of the 
project and 5 days for pile removal at the end (Table 1). Needle gun 
use will be for no more than 4 hours per day over a maximum of 6 days.
    The pile driving equipment will be deployed and operated from 
barges, on water. Materials will be delivered on barges.

                                   Table 1--Summary of Pile Driving Activities
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                                                    Number  of     Minutes  per                      Duration
            Method                  Pile type          piles           pile       Piles  per day      (days)
----------------------------------------------------------------------------------------------------------------
Vibratory Driving.............  Sheet...........              44              30               8               6
Vibratory Driving.............  H pile..........              20              30               8               3
Vibratory Removal.............  Sheet...........              44              15              16               3
Vibratory Removal.............  H pile..........              20              15              16               2
----------------------------------------------------------------------------------------------------------------

    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 
the project area and summarizes information related to the population 
or stock, including regulatory status under the MMPA and Endangered 
Species Act (ESA) and potential biological removal (PBR), where known. 
For taxonomy, we follow Committee on Taxonomy (2020). 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. Pacific or Alaska SARs (e.g., Caretta et al., 2020; Muto et 
al., 2020).

                    Table 2--Species That Spatially Co-Occur With the Activity to the Degree That Take Is Reasonably Likely To Occur
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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).
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[[Page 81890]]

 
                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
    Short-beaked Common Dolphin.....  Delphinus delphis......  California/Oregon/       -, -, N             969,861 (0.17,              8,393        >40
                                                                Washington.                                  839,325, 2014).
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena......  Washington Inland        -, -, N             11,233 (0.37, 8,308,           66      >=7.2
                                                                Waters.                                      2015).
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                                                         Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
 sea lions):
    California Sea Lion.............  Zalophus californianus.  United States..........  -, -, N             257,606 (N/A, 233,515,     14,011       >321
                                                                                                             2014).
    Steller Sea Lion................  Eumetopias jubatus.....  Eastern DPS............  -, -, N             43,201a (see SAR,           2,592        112
                                                                                                             43,201, 2017).
Family Phocidae (earless seals):
    Harbor Seal.....................  Phoca vitulina.........  Southern Puget Sound...  -, -, N             UNK (UNK, UNK, 1999)..        UND        3.4
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\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. UNK--Unknown, UND--Undetermined.
\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.

    Harbor seal, California sea lion, and Harbor porpoise spatially co-
occur with the activity to the degree that take is reasonably likely to 
occur, and we have proposed authorizing take of these species. For gray 
whale, Steller sea lion, and short-beaked common dolphin, occurrence is 
such that take is possible, and we have proposed authorizing take of 
these species also. All species that could potentially occur in the 
proposed survey areas are included in WADOT's IHA application (see 
application, Table 3-1).
    Transient killer whales (Orcinus orca) spatially co-occur with the 
activity to the degree that take is possible, while Southern Resident 
killer whales and humpback whales (Megaptera novaeangliae) are very 
rare visitors to the area. Work will be shutdown if any of these 
species approach the Level B harassment zone, so take is not requested 
for these species and they are not further discussed. Northern elephant 
seals (Mirounga angustirostris) have been observed in Puget Sound but 
are not anticipated to occur in the project area and no take of this 
species is anticipated or requested.

Gray Whale

    In the fall, gray whales migrate from their summer feeding grounds 
in the North Pacific and Arctic, heading south along the coast of North 
America to spend the winter in their breeding and calving areas off the 
coast of Baja California, Mexico. From mid-February to May, the Eastern 
North Pacific stock of gray whales can be seen migrating northward with 
newborn calves along the west coast of the U.S. During these 
migrations, gray whales will occasionally enter rivers and bays 
(including Puget Sound) along the coast but not in high numbers.
    An exception to this is a few hundred whales that summer and feed 
along the Pacific coast between Kodiak Island, Alaska and northern 
California, referred to as the ``Pacific Coast Feeding Group''. A 
subset of this group can often be found throughout Puget Sound 
(Calambokidis et al., 2017). One individual was observed near the Purdy 
Bridge in June 2013 (TWM, 2020).

Short-Beaked Common Dolphin

    Common dolphins occur in temperate and tropical waters globally. 
They are abundant off California but the distribution of short-beaked 
common dolphins throughout the project region is highly variable and 
generally rare, apparently in response to oceanographic changes on both 
seasonal and interannual time scales (Heyning and Perrin 1994; Forney 
1997; Forney and Barlow 1998). The Whale Museum database has some 
sightings of common dolphins in the area near the project, mostly in 
2016 and 2017 (TWM, 2020).
    Short-beaked common dolphins travel in large social pods and are 
generally associated with oceanic and offshore waters, prey-rich ocean 
upwellings, and underwater landscape features such as seamounts, 
continental shelves, and oceanic ridges. They largely forage on 
schooling fish and squid. Calving takes place in winter months. 
Abundance of the CA/OR/WA stock short-beaked common dolphins has 
increased since large-scale surveys began in 1991.

Harbor Porpoise

    Harbor porpoise occur along the US west coast from southern 
California to the Bering Sea (Carretta et al., 2020). They rarely occur 
in waters warmer than 62.6 degrees Fahrenheit (17 degrees Celsius; 
Read, 1990). The Washington Inland Waters stock is found from Cape 
Flattery throughout Puget Sound and the Salish Sea region. In southern 
Puget Sound, harbor porpoise were common in the 1940s, but marine 
mammal surveys, stranding records since the early 1970s, and harbor 
porpoise surveys in the early 1990's indicated that harbor porpoise 
abundance had declined in southern Puget Sound (Carretta et al., 2020). 
Annual winter aerial surveys conducted by the Washington Department of 
Fish and Wildlife from 1995 to 2015 revealed

[[Page 81891]]

an increasing trend in harbor porpoise in Washington inland waters, 
including the return of harbor porpoise to Puget Sound (Carretta et 
al., 2020). Seasonal surveys conducted in spring, summer, and fall 
2013-2015 in Puget Sound and Hood Canal documented substantial numbers 
of harbor porpoise in Puget Sound. Observed porpoise numbers were twice 
as high in spring as in fall or summer, indicating a seasonal shift in 
distribution.
    In most areas, harbor porpoise occur in small groups of just a few 
individuals. Harbor porpoise must forage nearly continuously to meet 
their high metabolic needs (Wisniewska et al., 2016). They consume up 
to 550 small fish (1.2-3.9 inches [3-10 cm]; e.g., anchovies) per hour 
at a nearly 90 percent capture success rate (Wisniewska et al., 2016).

California Sea Lion

    California sea lions occur from Vancouver Island, British Columbia, 
to the southern tip of Baja California. They breed on the offshore 
islands of southern and central California from May through July (Heath 
and Perrin, 2008). During the non-breeding season, adult and subadult 
males and juveniles migrate northward along the coast to central and 
northern California, Oregon, Washington, and Vancouver Island 
(Jefferson et al., 1993). They return south the following spring (Heath 
and Perrin 2008, Lowry and Forney, 2005). Females and some juveniles 
tend to remain closer to rookeries (Antonelis et al., 1990; Melin et 
al., 2008).
    Pupping occurs primarily on the California Channel Islands from 
late May until the end of June (Peterson and Bartholomew 1967). Weaning 
and mating occur in late spring and summer during the peak upwelling 
period (Bograd et al., 2009). After the mating season, adult males 
migrate northward to feeding areas as far away as the Gulf of Alaska 
(Lowry et al., 1992), and they remain away until spring (March-May), 
when they migrate back. Adult females generally remain south of 
Monterey Bay, California throughout the year, feeding in coastal waters 
in the summer and offshore waters in the winter, alternating between 
foraging and nursing their pups on shore until the next pupping/
breeding season (Melin and DeLong, 2000; Melin et al., 2008).
    California sea lions regularly occur on rocks, buoys and other 
structures. Occurrence in the project area is expected to be common. 
Some 3,000 to 5,000 animals are estimated to move into Pacific 
Northwest waters of Washington and British Columbia during the fall 
(September) and remain until the late spring (May) when most return to 
breeding rookeries in California and Mexico (Jeffries et al., 2000). 
Peak counts of over 1,000 animals have been made in Puget Sound 
(Jeffries et al., 2000). The nearest documented California sea lion 
haul out site to the project site are on the Toliva Shoals Buoys, 
approximately 26 km (16 water miles) to the south (Jeffries et al., 
2000). This haul out typically is used by less than 10 individuals at 
any one time.

Steller Sea Lion

    Steller sea lions range along the North Pacific Rim from northern 
Japan to California, with centers of abundance and distribution in the 
Gulf of Alaska and Aleutian Islands. Large numbers of individuals 
widely disperse when not breeding (late May to early July) to access 
seasonally important prey resources (Muto et al., 2019). They were 
listed as threatened range-wide under the ESA on November 26, 1990 (55 
FR 49204). Steller sea lions were subsequently partitioned into the 
western and eastern Distinct Population Segments (DPSs; western and 
eastern stocks) in 1997 (62 FR 24345, May 5, 1997). The western DPS 
breeds on rookeries located west of 144[deg] W in Alaska and Russia, 
whereas the eastern DPS breeds on rookeries in southeast Alaska through 
California. The eastern DPS was delisted in 2013.
    The eastern DPS is the only population of Steller's sea lions 
thought to occur in the project area. In Washington waters, numbers 
decline during the summer months, which correspond to the breeding 
season at Oregon and British Columbia rookeries (approximately late May 
to early June) and peak during the fall and winter months. Steller sea 
lion abundances vary seasonally with a minimum estimate of 1,000 to 
2,000 individuals present or passing through the Strait of Juan de Fuca 
in fall and winter months (Jeffries, et al. 2000). The nearest 
documented haul out site is also on the Toliva Shoals Buoys.

Harbor Seal

    Harbor seals are found from Baja California to the eastern Aleutian 
Islands of Alaska (Harvey and Goley, 2011). The animals in the project 
area are part of the Southern Puget Sound stock. Harbor seals are the 
most common marine mammal species observed in the project area and are 
the only one that breeds and remains in the inland marine waters of 
Washington year-round (Calambokidis and Baird, 1994).
    Harbor seals are central-place foragers (Orians and Pearson, 1979) 
and tend to exhibit strong site fidelity within season and across 
years, generally forage close to haulout sites, and repeatedly visit 
specific foraging areas (Grigg et al., 2012; Suryan and Harvey, 1998; 
Thompson et al., 1998). Harbor seals in San Francisco Bay forage mainly 
within 7 mi (10 km) of their primary haulout site (Grigg et al., 2012), 
and often within just 1-3 mi (1-5 km; Torok, 1994). Depth, bottom 
relief, and prey abundance also influence foraging location (Grigg et 
al., 2012).
    Harbor seals molt from May through June. Peak numbers of harbor 
seals haul out during late May to early June, which coincides with the 
peak molt. During both pupping and molting seasons, the number of seals 
and the length of time hauled out per day increase, from an average of 
7 hours per day to 10-12 hours (Harvey and Goley, 2011; Huber et al., 
2001; Stewart and Yochem, 1994).
    Harbor seals tend to forage at night and haul out during the day 
with a peak in the afternoon between 1 p.m. and 4 p.m. (Grigg et al., 
2012; London et al., 2001; Stewart and Yochem, 1994; Yochem et al., 
1987). Tide levels affect the maximum number of seals hauled out, with 
the largest number of seals hauled out at low tide, but time of day and 
season have the greatest influence on haul out behavior (Manugian et 
al., 2017; Patterson and Acevedo-Guti[eacute]rrez, 2008; Stewart and 
Yochem, 1994).
    The closest haulout to the project area is the Rosedale Beach 
floats located 5.8 km (3.6 miles) to the southwest, but not in direct 
line-of-sight contact with the project location (see application Figure 
3-1).

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

[[Page 81892]]

cetaceans). Subsequently, NMFS (2018) described generalized hearing 
ranges for these marine mammal hearing groups. Generalized hearing 
ranges were chosen based on the approximately 65 decibel (dB) threshold 
from the normalized composite audiograms, with the exception for lower 
limits for low-frequency cetaceans where the lower bound was deemed to 
be biologically implausible and the lower bound from Southall et al. 
(2007) retained. Marine mammal hearing groups and their associated 
hearing ranges are provided in Table 3.

                  Table 3--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
        Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans   7 Hz to 35 kHz.
 (baleen whales).
Mid-frequency (MF) cetaceans   150 Hz to 160 kHz.
 (dolphins, toothed whales,
 beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans  275 Hz to 160 kHz.
 (true porpoises, Kogia,
 river dolphins,
 cephalorhynchid,
 Lagenorhynchus cruciger & L.
 australis).
Phocid pinnipeds (PW)          50 Hz to 86 kHz.
 (underwater) (true seals).
Otariid pinnipeds (OW)         60 Hz to 39 kHz.
 (underwater) (sea 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. 
Gray whales are low frequency cetaceans, short-beaked common dolphins 
are mid-frequency cetaceans, harbor porpoises are classified as high-
frequency cetaceans, Harbor seals are in the phocid group, and Steller 
sea lions and California sea lions are otariids.

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 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 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.
    Acoustic effects on marine mammals during the specified activity 
can occur from vibratory pile driving and potentially from needle gun 
use. The effects of underwater noise from WADOT's proposed activities 
have the potential to result in Level A or Level B harassment of marine 
mammals in the action area. The effects of in-air noise from WADOT's 
proposed needle gun use have the potential to result in Level B 
harassment of pinnipeds in the action area.

Description of Sound Sources

    The marine soundscape is comprised of both ambient and 
anthropogenic sounds. Ambient sound is defined as the all-encompassing 
sound in a given place and is usually a composite of sound from many 
sources both near and far (ANSI 1995). 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.
    Construction activities associated with the project would include 
vibratory pile driving, vibratory pile removal and needle guns. 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., machinery 
operations such as drilling or dredging, vibratory pile driving, needle 
guns, 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).
    Vibratory pile hammers would be used on this project. 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

[[Page 81893]]

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).
    Needle guns are a drill like tool that use a series of strong 
elongate metal chisels or ``bristles'' to scrape away material using 
high speed rotation up to 5000 revolution per minute. Sounds are 
produced by the tool motor as well as the scraping action of the tool 
on concrete. Peak SPLs are up to 112 dBA (OSHA, 2020).
    The likely or possible impacts of WADOT'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 also 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 WADOT's specified activity. In 
general, animals exposed to natural or anthropogenic sound may 
experience physical and psychological effects, ranging in magnitude 
from none to severe (Southall et al., 2007). Generally, exposure to 
pile driving and removal 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 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., 2003; 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, with the 
exception of a single study unintentionally inducing PTS in a harbor 
seal (Kastak et al., 2008), there are no empirical data measuring PTS 
in marine mammals, largely due to the fact that, for various ethical 
reasons, experiments involving anthropogenic noise exposure at levels 
inducing PTS are not typically pursued or authorized (NMFS, 2018).
    Temporary Threshold Shift (TTS)--A temporary, reversible increase 
in the threshold of audibility at a specified frequency or portion of 
an individual's hearing range above a previously established reference 
level (NMFS, 2018). Based on data from cetacean TTS measurements (see 
Southall et al., 2007), a TTS of 6 dB is considered the minimum 
threshold shift clearly larger than any day-to-day or session-to-
session variation in a subject's normal hearing ability (Schlundt et 
al., 2000; Finneran et al., 2000, 2002). As described in Finneran 
(2016), marine mammal studies have shown the amount of TTS increases 
with cumulative sound exposure level (SELcum) in an 
accelerating fashion: At low exposures with lower SELcum, 
the amount of TTS is typically small and the growth curves have shallow 
slopes. At exposures with higher 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, 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). The potential for TTS from impact pile driving 
exists. After exposure to playbacks of impact pile driving sounds (rate 
2760 strikes/hour) in captivity, mean TTS increased from 0 dB after 15 
minute exposure to 5 dB after 360 minute exposure; recovery occurred 
within 60 minutes (Kastelein et al., 2016). Additionally, the existing

[[Page 81894]]

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).
    For this project, there would likely be pauses in activities 
producing the sound during each day. Given these pauses and that many 
marine mammals are likely moving through the action area and not 
remaining for extended periods of time, the potential for TS declines.
    Behavioral Harassment--Exposure to noise from pile driving and 
removal and needle gun use also has the potential to behaviorally 
disturb marine mammals. Available studies show wide variation in 
response to underwater sound; therefore, it is difficult to predict 
specifically how any given sound in a particular instance might affect 
marine mammals perceiving the signal. If a marine mammal does react 
briefly to an underwater sound by changing its behavior or moving a 
small distance, the impacts of the change are unlikely to be 
significant to the individual, let alone the stock or population. 
However, if a sound source displaces marine mammals from an important 
feeding or breeding area for a prolonged period, impacts on individuals 
and populations could be significant (e.g., Lusseau and Bejder, 2007; 
Weilgart, 2007; NRC, 2005).
    Disturbance may result in changing durations of surfacing and 
dives, number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities; changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping); avoidance of areas where sound sources are located. 
Pinnipeds may increase their haul out time, possibly to avoid in-water 
disturbance (Thorson and Reyff, 2006). Behavioral responses to sound 
are highly variable and context-specific and any reactions depend on 
numerous intrinsic and extrinsic factors (e.g., species, state of 
maturity, experience, current activity, reproductive state, auditory 
sensitivity, time of day), as well as the interplay between factors 
(e.g., Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 
2007; Weilgart, 2007; Archer et al., 2010). Behavioral reactions can 
vary not only among individuals but also within an individual, 
depending on previous experience with a sound source, context, and 
numerous other factors (Ellison et al., 2012), and can vary depending 
on characteristics associated with the sound source (e.g., whether it 
is moving or stationary, number of sources, distance from the source). 
In general, pinnipeds seem more tolerant of, or at least habituate more 
quickly to, potentially disturbing underwater sound than do cetaceans, 
and generally seem to be less responsive to exposure to industrial 
sound than most cetaceans. Please see Appendices B and 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). Whether or not foraging disruptions have the potential to incur 
fitness consequences is dependent upon the intensity and duration of 
the disturbance, the energetic requirements of the affected 
individuals, and the relationship between prey availability, foraging 
effort and success, and the life history stage of the animal.
    In 2016, the Alaska Department of Transportation and Public 
Facilities (ADOT&PF) documented observations of marine mammals during 
construction activities (i.e., pile driving) at the Kodiak Ferry Dock 
(80 FR 60636, October 7, 2015). In the marine mammal monitoring report 
for that project (ABR 2016), 1,281 Steller sea lions were observed 
within the Level B harassment zone during pile driving or drilling 
(i.e., documented as Level B harassment take). Of these, 19 individuals 
demonstrated an alert behavior, 7 fled, and 19 swam away from the 
project site. All other animals (98 percent) were engaged in activities 
such as milling, foraging, or fighting and did not change their 
behavior. In addition, two sea lions approached within 20 meters of 
active vibratory pile driving activities. Three harbor seals were 
observed within the disturbance zone during pile driving activities; 
none of them displayed disturbance behaviors. Fifteen killer whales and 
three harbor porpoise were also observed within the Level B harassment 
zone during pile driving. The killer whales were travelling or milling 
while all harbor porpoises were travelling. No signs of disturbance 
were noted for either of these species. Given the similarities in 
activities and habitat, we expect similar behavioral responses of 
marine mammals to WADOT's specified activity. That is, disturbance, if 
any, is likely to be temporary and localized (e.g., small area 
movements).
    Stress responses--An animal's perception of a threat may be 
sufficient to trigger stress responses consisting of some combination 
of behavioral responses, autonomic nervous system responses, 
neuroendocrine responses, or immune responses (e.g., Selye 1950; Moberg 
2000). In many cases, an animal's first and sometimes most economical 
(in terms of energetic costs) response is behavioral avoidance of the 
potential stressor. Autonomic nervous system responses to stress 
typically involve changes in heart rate, blood pressure, and 
gastrointestinal activity. These responses have a relatively short 
duration and may or may not have a significant long-term effect on an 
animal's fitness.
    Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction, altered metabolism, reduced immune 
competence, and behavioral disturbance (e.g., Moberg 1987; Blecha 
2000). Increases in the circulation of glucocorticoids are also equated 
with stress (Romano et al., 2004).
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and ``distress'' is the cost of 
the response. During a stress response, an animal uses glycogen stores 
that can be quickly replenished once the stress is alleviated. In such 
circumstances, the cost of the stress response would not pose serious 
fitness consequences. However, when an animal does not have sufficient 
energy reserves to satisfy the energetic costs of a stress response, 
energy resources must be diverted from other functions. This state of 
distress will last until the animal replenishes its energetic reserves 
sufficient to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well-studied through 
controlled experiments and for both laboratory and free-ranging animals

[[Page 81895]]

(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003; 
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to 
exposure to anthropogenic sounds or other stressors and their effects 
on marine mammals have also been reviewed (Fair and Becker 2000; Romano 
et al., 2002b) and, more rarely, studied in wild populations (e.g., 
Romano et al., 2002a). For example, Rolland et al. (2012) found that 
noise reduction from reduced ship traffic in the Bay of Fundy was 
associated with decreased stress in North Atlantic right whales. These 
and other studies lead to a reasonable expectation that some marine 
mammals will experience physiological stress responses upon exposure to 
acoustic stressors and that it is possible that some of these would be 
classified as ``distress.'' In addition, any animal experiencing TTS 
would likely also experience stress responses (NRC, 2003), however 
distress is an unlikely result of this project based on observations of 
marine mammals during previous, similar projects in the area.
    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. The 
Henderson Bay area contains mostly small recreational and commercial 
vessel traffic and background sound levels in the area are not 
excessively elevated.
    Airborne Acoustic Effects--Pinnipeds that occur near the project 
site could be exposed to airborne sounds associated with pile driving 
and removal and needle gun use that have the potential to cause 
behavioral harassment, depending on their distance from pile driving 
activities. Cetaceans are not expected to be exposed to airborne sounds 
that would result in harassment as defined under the MMPA.
    Airborne noise would primarily be an issue for pinnipeds that are 
swimming or hauled out near the project site within the range of noise 
levels elevated above the acoustic criteria. We recognize that 
pinnipeds in the water could be exposed to airborne sound that may 
result in behavioral harassment when looking with their heads above 
water. Most likely, airborne sound would cause behavioral responses 
similar to those discussed above in relation to underwater sound. For 
instance, anthropogenic sound could cause hauled-out pinnipeds to 
exhibit changes in their normal behavior, such as reduction in 
vocalizations, or cause them to temporarily abandon the area and move 
further from the source. However, for pile-driving/removal 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 
the in-water estimates of potential take. Therefore, we do not believe 
that authorization of incidental take resulting from airborne sound 
from pile driving for pinnipeds is warranted. Since the needle gun will 
be used on days when there is no pile driving, behavioral harassment 
from its use could occur and is discussed below.

Marine Mammal Habitat Effects

    WADOT's construction activities could have localized, temporary 
impacts on marine mammal habitat and their prey by increasing in-water 
sound pressure levels and slightly decreasing water quality. Increased 
noise levels may affect acoustic habitat (see Masking above) and 
adversely affect marine mammal prey in the vicinity of the project area 
(see discussion below). During vibratory pile driving or removal, 
elevated levels of underwater noise would ensonify the project area 
where both fishes and mammals occur and could affect foraging success. 
Additionally, marine mammals may avoid the area during construction, 
however, displacement due to noise is expected to be temporary and is 
not expected to result in long-term effects to the individuals or 
populations. Construction activities are of short duration and would 
likely have temporary impacts on marine mammal habitat through 
increases in underwater and airborne sound.
    A temporary and localized increase in turbidity near the seafloor 
would occur in the immediate area surrounding the area where piles are 
installed or removed. In general, turbidity associated with pile 
installation is localized to about a 25-foot (7.6-meter) radius around 
the pile (Everitt et al. 1980). The sediments of the project site will 
settle out rapidly when disturbed. Cetaceans are not expected to be 
close enough to the pile driving areas to experience effects of 
turbidity, and any pinnipeds could avoid localized areas of turbidity. 
Local strong currents are anticipated to disburse any additional 
suspended sediments produced by project activities at moderate to rapid 
rates depending on tidal stage. Therefore, we expect the impact from 
increased turbidity levels to be discountable to marine mammals and do 
not discuss it further.

In-Water Construction Effects on Potential Foraging Habitat

    The area likely impacted by the project is relatively small 
compared to the available habitat (e.g., the impacted area is in the 
north of the bay only) of Henderson Bay and does not include any 
Biologically Important Areas or other habitat of known importance. The 
area is highly influenced by anthropogenic activities. The total 
seafloor area affected by pile installation and removal is a very small 
area compared to the vast foraging area available to marine mammals in 
the Henderson Bay and Puget Sound. At best, the impact area provides 
marginal foraging habitat for marine mammals and fishes. 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.

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    In-water Construction Effects on Potential Prey--Sound may affect 
marine mammals through impacts on the abundance, behavior, or 
distribution of prey species (e.g., crustaceans, cephalopods, fish, 
zooplankton). Marine mammal prey varies by species, season, and 
location. Here, we describe studies regarding the effects of noise on 
known marine mammal prey.
    Fish utilize the soundscape and components of sound in their 
environment to perform important functions such as foraging, predator 
avoidance, mating, and spawning (e.g., Zelick and Mann, 1999; Fay, 
2009). Depending on their hearing anatomy and peripheral sensory 
structures, which vary among species, fishes hear sounds using pressure 
and particle motion sensitivity capabilities and detect the motion of 
surrounding water (Fay et al., 2008). The potential effects of noise on 
fishes depends on the overlapping frequency range, distance from the 
sound source, water depth of exposure, and species-specific hearing 
sensitivity, anatomy, and physiology. Key impacts to fishes may include 
behavioral responses, hearing damage, barotrauma (pressure-related 
injuries), and mortality.
    Fish react to sounds which are especially strong and/or 
intermittent low-frequency sounds, and behavioral responses such as 
flight or avoidance are the most likely effects. Short duration, sharp 
sounds can cause overt or subtle changes in fish behavior and local 
distribution. The reaction of fish to noise depends on the 
physiological state of the fish, past exposures, motivation (e.g., 
feeding, spawning, migration), and other environmental factors. 
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). Several studies have demonstrated that impulse sounds might 
affect the distribution and behavior of some fishes, potentially 
impacting foraging opportunities or increasing energetic costs (e.g., 
Fewtrell and McCauley, 2012; Pearson et al., 1992; Skalski et al., 
1992; Santulli et al., 1999; Paxton et al., 2017). However, some 
studies have shown no or slight reaction to impulse sounds (e.g., Pena 
et al., 2013; Wardle et al., 2001; Jorgenson and Gyselman, 2009; Cott 
et al., 2012).
    SPLs of sufficient strength have been known to cause injury to fish 
and fish mortality. However, in most fish species, hair cells in the 
ear continuously regenerate and loss of auditory function likely is 
restored when damaged cells are replaced with new cells. Halvorsen et 
al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours 
for one species. Impacts would be most severe when the individual fish 
is close to the source and when the duration of exposure is long. 
Injury caused by barotrauma can range from slight to severe and can 
cause death, and is most likely for fish with swim bladders. Barotrauma 
injuries have been documented during controlled exposure to impact pile 
driving (Halvorsen et al., 2012b; Casper et al., 2013).
    The most likely impact to fish from pile driving and removal 
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 (Hastings and Popper, 2005, 
Popper and Hastings, 2009).
    Construction activities, in the form of increased turbidity, have 
the potential to adversely affect forage fish in the project area. 
Forage fish form a significant prey base for many marine mammal species 
that occur in the project area. Increased turbidity is expected to 
occur in the immediate vicinity (on the order of 10 ft (3 m) or less) 
of construction activities. However, suspended sediments and 
particulates are expected to dissipate quickly within a single tidal 
cycle. Given the limited area affected and high tidal dilution rates 
any effects on forage fish are expected to be minor or negligible. 
Finally, exposure to turbid waters from construction activities is not 
expected to be different from the current exposure; fish and marine 
mammals in Henderson Bay are routinely exposed to substantial levels of 
suspended sediment from natural and anthropogenic sources.
    In summary, given the short daily duration of sound associated with 
individual pile driving 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. 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. 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 be by Level B harassment, as use of the 
acoustic source (i.e., vibratory pile driving/removal and needle gun) 
has the potential to result in disruption of behavioral patterns for 
individual marine mammals. Based on the nature of the activity and the 
anticipated effectiveness of the mitigation measures (i.e., shutdown)--
discussed in detail below in Proposed Mitigation section, Level A 
harassment is neither anticipated nor proposed to be authorized.
    As described previously, no mortality is anticipated or proposed to 
be authorized for this activity. Below we describe how the take is 
estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
and the number of days of activities. We note that while these basic 
factors can contribute to a basic calculation to provide an initial 
prediction of takes, additional information that can qualitatively 
inform take estimates is also sometimes available (e.g., previous 
monitoring results or average group size). Below, we describe the 
factors considered here in

[[Page 81897]]

more detail and present the proposed take estimate.
    The effect of needle guns is unclear as we have not recently 
authorized take by this method in these circumstances. Given the 
relatively low source level for needle guns and small ensonified areas 
discussed below, there is some uncertainty about whether take will 
occur from this activity. However, in consideration of the applicant's 
request and the predicted source levels, we conservatively propose the 
authorization of some take for this project.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment). Thresholds have also been developed identifying the 
received level of in-air sound above which exposed pinnipeds would 
likely be behaviorally harassed.
    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) and above 160 dB 
re 1 [mu]Pa (rms) for non-explosive impulsive (e.g., impact pile 
driving) or intermittent (e.g., scientific sonar) sources. For in-air 
sounds, NMFS predicts that harbor seals exposed above received levels 
of 90 dB re 20 [mu]Pa (rms) will be behaviorally harassed, and other 
pinnipeds will be harassed when exposed above 100 dB re 20 [mu]Pa 
(rms).
    WADOT's proposed activity includes the use of continuous (vibratory 
pile-driving and removal in water and needle guns) in air sources, and 
therefore the 120 dB re 1 [mu]Pa (rms) threshold is applicable in water 
and the pinniped thresholds are applicable in air.
    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). WADOT's activity includes the use of non-
impulsive (vibratory pile driving/removal) sources.
    These thresholds are provided in 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                       ------------------------------------------------------
                                                                               Non-Impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans.............................  Cell 2: LE,LF,24h: 199 dB.
Mid-Frequency (MF) Cetaceans.............................  Cell 4: LE,MF,24h: 198 dB.
High-Frequency (HF) Cetaceans............................  Cell 6: LE,HF,24h: 173 dB.
Phocid Pinnipeds (PW) (Underwater).......................  Cell 8: LE,PW,24h: 201 dB.
Otariid Pinnipeds (OW) (Underwater)......................  Cell 10: LE,OW,24h: 219 dB.
----------------------------------------------------------------------------------------------------------------
Note: 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). 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., vibratory pile driving and 
removal and needle guns).
    Vibratory hammers produce constant sound when operating, and 
produce vibrations that liquefy the sediment surrounding the pile, 
allowing it to penetrate to the required seating depth. The actual 
durations of each installation method vary depending on the type and 
size of the pile.
    In order to calculate distances to the Level A harassment and Level 
B harassment sound thresholds for piles of various sizes being used in 
this project, NMFS used acoustic monitoring data from other locations 
to develop source levels or the various pile types, sizes and methods 
(see Table 5). Source levels for the 48-inch sheetpiles come from the 
Caltrans compendium (2015) measurements of 24-inch steel sheetpiles 
supported by acoustic data from another project in Seattle, Washington 
that used 48-inch steel sheetpiles (Greenbusch Group, 2015), while the 
source data for H piles comes from the Caltrans (2015) compendium. 
Needle guns can produce sounds up to 112 dbA (OSHA, 2020) and we use 
that as the source level for that activity.

[[Page 81898]]



                                      Table 5--Project Sound Source Levels
----------------------------------------------------------------------------------------------------------------
                Method                        Pile type          Estimated noise level            Source
----------------------------------------------------------------------------------------------------------------
Vibratory Driving/Removal............  48-inch sheet..........  165 dBRMS..............  CALTRANS 2015,
                                                                                          Greenbusch Group 2015.
Vibratory Driving/Removal............  12-inch H pile.........  150 dBRMS..............  CALTRANS 2015.
----------------------------------------------------------------------------------------------------------------
Note: SEL = single strike sound exposure level; dB peak = peak sound level; rms = root mean square.

Level B Harassment Zones

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

TL = B * Log10 (R1/R2)

where

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

    The recommended TL coefficient for most nearshore environments is 
the practical spreading value of 15. This value results in an expected 
propagation environment that would lie between spherical and 
cylindrical spreading loss conditions, which is the most appropriate 
assumption for WADOT's proposed activity in the absence of specific 
modelling.
    Using the equation above, underwater noise is predicted to fall 
below the behavioral effects threshold of 120 dB rms for marine mammals 
at distances of 1,000 or 10,000 m depending on the pile type(s) and 
methods (Table 6). It should be noted that based on the geography of 
Henderson Bay, sound will not reach the full distance of the Level B 
harassment isopleths in most directions. In-air needle gun noise is 
predicted to reach the phocid (harbor seal) threshold (90 dB) at 192 
meters (629 feet), and the otariid threshold (100 dB) at 60 meters (200 
feet).

           Table 6--Level A and Level B Harassment Isopleths (m) for Each Pile Type and Hearing Group
----------------------------------------------------------------------------------------------------------------
                                                          Level A harassment
                                  -----------------------------------------------------------------    Level B
            Pile type                  Low          Mid          High                                harassment
                                    frequency    frequency    frequency     Otariid       Phocid
----------------------------------------------------------------------------------------------------------------
Sheet............................         31.8          2.8           47         19.3          1.4        10,000
H pile...........................          3.2          0.3          4.7          1.9          0.1         1,000
----------------------------------------------------------------------------------------------------------------

Level A Harassment Zones

    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that ensonified area/volume could be more 
technically challenging to predict because of the duration component in 
the new thresholds, we developed a User Spreadsheet that includes tools 
to help predict a simple isopleth that can be used in conjunction with 
marine mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which may result in some degree of 
overestimate of take by Level A harassment. 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 
vibratory pile driving or removal using any of the methods discussed 
above, NMFS User Spreadsheet predicts the closest distance at which, if 
a marine mammal remained at that distance the whole duration of the 
activity, it would not incur PTS. Inputs used in the User Spreadsheet 
are reported in Table 7 and the resulting isopleths are reported in 
Table 6 for each of the work scenarios. Note that while the inputs for 
driving and removal of each type of pile are different, the resulting 
isopleths are the same because the total time per day (number of piles 
per day times minutes per pile) of pile driving is identical. Therefore 
Table 6 includes only a single row for each pile type. The above input 
scenarios lead to PTS isopleth distances (Level A thresholds) of less 
than 1 m to 47 m.
    The Level A harassment zones identified in Table 6 are based upon 
an animal exposed to pile driving multiple piles per day. Considering 
duration of driving or removing each pile (up to 30 minutes) and breaks 
between pile installations (to reset equipment and move pile into 
place), this means an animal would have to remain within the small area 
estimated to be ensonified above the Level A harassment threshold for 
multiple hours. This is highly unlikely given marine mammal movement 
throughout the area.

Table 7--NMFS Technical Guidance User Spreadsheet Input To Calculate Level A Isopleths for a Combination of Pile
                                                     Driving
----------------------------------------------------------------------------------------------------------------
                                                                                    Minutes per
              Method                      Pile type             Source level           pile        Piles per day
----------------------------------------------------------------------------------------------------------------
Vibratory Driving.................  Sheet................  165 db RMS...........              30               8
Vibratory Driving.................  H pile...............  150 db RMS...........              30               8
Vibratory Removal.................  Sheet................  165 db RMS...........              15              16

[[Page 81899]]

 
Vibratory Removal.................  H pile...............  150 db RMS...........              15              16
----------------------------------------------------------------------------------------------------------------
Note: Transmission Loss for all methods is 15 LogR and the weighting factor adjustment is 2.5.

Marine Mammal Occurrence and Take Calculation and Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations. The main source of density information for the area is 
the U.S. Navy's database used to establish baseline density estimates 
for their construction and testing and training activities in Puget 
Sound (U.S. Navy, 2019). The Navy database includes seasonal estimates 
of abundance where available and appropriate. Where such estimates 
existed, we used the larger density estimate for the fall or summer 
seasons, when this project is scheduled to occur. These density 
estimates are shown in Table 8. No density estimates exist for the 
rarer short-beaked common dolphin so we used more qualitative data on 
observations from The Whale Museum's sightings database and project 
specific report to WADOT (TWM, 2020).

   Table 8--Density of Marine Mammals Used To Calculate Expected Take
------------------------------------------------------------------------
                        Species                          Density #/km\2\
------------------------------------------------------------------------
Harbor seal............................................             3.91
California sea lion....................................           0.2211
Steller sea lion.......................................           0.0478
Gray whale.............................................         0.000086
Short-beaked common dolphin............................  ([hairsp]*[hair
                                                                    sp])
Harbor porpoise........................................             0.86
------------------------------------------------------------------------
* See text, no density estimate exists for short-beaked common dolphins.

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate. Given the geography 
of the project area, the area ensonified when driving or removing H 
piles is 1.36 km\2\ (0.53 mi\2\), the area ensonified when driving or 
removing sheetpiles is 17.9 km\2\ (6.9 mi\2\), and the area ensonified 
when using the needle gun is 0.06 km\2\ (0.023 mi\2\) for phocids and 
0.01 km\2\ (0.004 mi\2\) for otariids. As noted above, there will be a 
total of 5 days driving or removing H piles, 9 days driving or removing 
sheetpiles, and 6 days of using the needle gun. For species with 
density estimates, the estimated take is calculated as the sum of the 
density times the area and days for each pile type/activity with the 
results for each activity added to give a total estimated take. 
Additional qualitative factors may be considered for species with small 
estimated take calculations (see below). Take by Level B harassment is 
proposed for authorization and summarized in Table 9.

Gray Whale

    The Navy Marine Species Density Database (U.S. Navy 2019) estimates 
the density of gray whales in the Henderson Bay area as 0.000086/km\2\. 
Based on this density estimate, the following number of gray whales may 
be present in the Level B harassment zones:

H piles: 0.000086/km\2\ * 1.36 km\2\ * 5 days = 0.0005848
Sheetpiles: 0.000086/km\2\ * 17.9 km\2\ * 9 days = 0.0138546
Total Estimated Take = 0.014 animals

    The total represents less than one gray whale. In the event an 
individual enters the area and remains for some time and is harassed on 
multiple days, we are proposing authorization for Level B harassment of 
10 gray whales. Because the Level A harassment zones are relatively 
small and we believe the PSO will be able to effectively monitor the 
Level A harassment zones, we do not anticipate or propose take by Level 
A harassment of gray whales.

Short-Beaked Common Dolphin

    As mentioned above, the Navy Marine Species Density Database (U.S. 
Navy 2019) does not provide an estimate of density of short-beaked 
common dolphins in the Henderson Bay area. The Whale Museum data 
indicate that common dolphins have been documented in waters adjacent 
to the project (TWM, 2020). Nearly all sightings were in 2016 and 2017 
pointing out the variability and uncertainty of their presence. Short-
beaked common dolphins often occur in groups; for the Puget Sound data 
groups consisted of no more than five individuals (Orca Network. 2020). 
Due to the low likelihood of occurrence an expectation of one group of 
five animals in the large level B harassment zone for sheetpiles per 
day is a reasonable representation of occurrence. With 9 days of 
sheetpiling maximum this equates to 45 level B takes. Because of the 
smaller size of the Level B harassment zones for the H-piles, we expect 
that one group of five animals over the course of the 5 work days with 
H piles is a reasonable representation of occurrence. We are thus 
proposing authorization for Level B harassment of 50 short-beaked 
common dolphins. Because the Level A harassment zones are relatively 
small and we believe the PSO will be able to effectively monitor the 
Level A harassment zones, we do not anticipate or propose take by Level 
A harassment of short-beaked common dolphins.

Harbor Porpoise

    The Navy Marine Species Density Database (U.S. Navy 2019) estimates 
the density of harbor porpoise in the Henderson Bay area as 0.86/km\2\. 
Based on this density estimate, the following number of harbor 
porpoises may be present in the Level B harassment zones:

H piles: 0.86/km\2\ * 1.36 km\2\ * 5 days = 5.848
Sheetpiles: 0.86/km\2\ * 17.9 km\2\ * 9 days = 138.546
Total Estimated Take = 144.4 animals


[[Page 81900]]


    We are proposing authorization for Level B harassment of 145 harbor 
porpoises. Because the Level A harassment zones are relatively small 
and we believe the PSO will be able to effectively monitor the Level A 
harassment zones, we do not anticipate or propose take by Level A 
harassment of harbor porpoises.

California Sea Lion

    The Navy Marine Species Density Database (U.S. Navy 2019) estimates 
the density of California sea lions in the Henderson Bay area as 
0.2211/km\2\. Based on this density estimate, the following number of 
California sea lions may be present in the Level B harassment zones:

H piles: 0.2211/km\2\ * 1.36 km\2\ * 5 days = 1.503
Sheetpiles: 0.2211/km\2\ * 17.9 km\2\ * 9 days = 35.619
Needle gun: 0.2211/km\2\ * 0.01 km\2\ * 6 days = 0.013
Total Estimated Take = 37.14 animals

    We are proposing authorization for Level B harassment of 38 
California sea lions. Because the Level A harassment zones are 
relatively small and we believe the PSO will be able to effectively 
monitor the Level A harassment zones, we do not anticipate or propose 
take by Level A harassment of California sea lions.

Steller Sea Lion

    The Navy Marine Species Density Database (U.S. Navy 2019) estimates 
the density of Steller sea lions in the Henderson Bay area as 0.0478/
km\2\. Based on this density estimate, the following number of Steller 
sea lions may be present in the Level B harassment zones:

H piles: 0.0478/km\2\ * 1.36 km\2\ * 5 days = 0.325
Sheetpiles: 0.0478/km\2\ * 17.9 km\2\ * 9 days = 7.70
Needle gun: 0.0478/km\2\ * 0.01 km\2\ * 6 days = 0.007
Total Estimated Take = 8.03 animals

    We are proposing authorization for Level B harassment of nine 
Steller sea lions. Because the Level A harassment zones are relatively 
small and we believe the PSO will be able to effectively monitor the 
Level A harassment zones, we do not anticipate or propose take by Level 
A harassment of Steller sea lions.

Harbor Seal

    The Navy Marine Species Density Database (U.S. Navy 2019) estimates 
the density of harbor seal in the Henderson Bay area as 3.91/km\2\. 
Based on this density estimate, the following number of harbor seals 
may be present in the Level B harassment zones:

H piles: 3.91/km\2\ * 1.36 km\2\ * 5 days = 26.588
Sheetpiles: 3.91/km\2\ * 17.9 km\2\ * 9 days = 629.901
Needle gun: 3.91/km\2\ * 0.06 km\2\ * 6 days = 1.408
Total Estimated Take = 657.9 animals

    We are proposing authorization for Level B harassment of 658 harbor 
seals.

Table 9--Proposed Authorized Amount of Taking, by Level A Harassment and
  Level B Harassment, by Species and Stock and Percent of Take by Stock
------------------------------------------------------------------------
                                                            Percent of
                 Species                   Take request        stock
------------------------------------------------------------------------
Harbor seal.............................             658             (*)
California sea lion.....................              38            <0.1
Steller sea lion........................               9            <0.1
Gray whale..............................              10             0.4
Short-beaked common dolphin.............              50            <0.1
Harbor porpoise.........................             145             1.3
------------------------------------------------------------------------
* There is no official estimate of stock size for this stock.

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 the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned); and
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    The following mitigation measures are proposed in the IHA:
     For in-water heavy machinery work other than pile driving/
removal (e.g., standard barges, etc.), and for needle gun work, 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 or around the pile 
location; or (2) positioning of the pile on the substrate via a crane 
(i.e., stabbing the pile);
     Conduct briefings between construction supervisors and 
crews and the marine mammal monitoring team prior to the start of all 
pile driving/removal activity and when new personnel join the work, to 
explain

[[Page 81901]]

responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures;
     For those marine mammals for which Level B harassment take 
has not been requested, in-water pile installation/removal will shut 
down immediately if such species are observed within or entering the 
Level B harassment zone; and
     If take reaches the authorized limit for an authorized 
species, pile installation/removal will be stopped as these species 
approach the Level B harassment zone to avoid additional take.
    The following mitigation measures would apply to WADOT's in-water 
construction activities.
     Establishment of Shutdown Zones--WADOT will establish 
shutdown zones for all pile driving and removal activities (Table 10). 
The purpose of a shutdown zone is generally to define an area within 
which shutdown of the activity would occur upon sighting of a marine 
mammal (or in anticipation of an animal entering the defined area). 
Shutdown zones typically vary based on the activity type and marine 
mammal hearing group (Table 4). Because the zones are small in this 
project, and WADOT seeks to simplify their monitoring, they have 
requested to establish shutdown zones of the same size that apply 
separately to cetaceans and pinnipeds, rather than having multiple size 
zones within each of these marine mammal groups corresponding to each 
hearing group. Therefore the shutdown zones are based on the largest 
Level A harassment zone within the cetacean and pinniped groups, 
respecitively, with an absolute minimum shutdown zone size of 10 m (33 
ft).
     Pile wake-up--When removing piles WADOT will shake the 
pile slightly prior to removal to break the bond with surrounding 
sediment to avoid pulling out large blocks of sediment. Piles they will 
also be removed slowly to minimize turbidity.
     The placement of Protected Species Observers (PSOs) during 
all pile driving and removal activities (described in detail in the 
Proposed Monitoring and Reporting section) will ensure that the entire 
shutdown zone is visible during pile installation. Should environmental 
conditions deteriorate such that marine mammals within the entire 
shutdown zone would not be visible (e.g., fog, heavy rain), pile 
driving and removal must be delayed until the PSO is confident marine 
mammals within the shutdown zone could be detected.
     Monitoring for Level B Harassment--WADOT will monitor the 
Level A and B harassment and shutdown zones. 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 halt of 
activity should the animal enter the shutdown zone. Placement of PSOs 
will allow PSOs to observe marine mammals within the Level B harassment 
zones that serve as monitoring zones.
     Pre-activity Monitoring--Prior to the start of daily in-
water construction activity, or whenever a break in pile driving/
removal 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 considered 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. When a 
marine mammal for which Level B harassment take is authorized is 
present in the Level B harassment zone, activities may begin and Level 
B harassment take will be recorded. If the entire Level B harassment 
zone is not visible at the start of construction, pile driving 
activities can begin. If work ceases for more than 30 minutes, the pre-
activity monitoring of the shutdown zones will commence.
     Pile driving or removal must occur during daylight hours.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, 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.

              Table 10--Shutdown Zones (Radius in Meters) by Pile Type, Activity and Hearing Group
----------------------------------------------------------------------------------------------------------------
            Pile type              Low frequency   Mid frequency  High frequency      Otariid         Phocid
----------------------------------------------------------------------------------------------------------------
Sheet...........................              50              50              50              20              20
H pile..........................              10              10              10              10              10
----------------------------------------------------------------------------------------------------------------

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;

[[Page 81902]]

     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.

Visual Monitoring

    Marine mammal monitoring must be conducted in accordance with the 
Monitoring Plan and section 5 of the IHA. Marine mammal monitoring 
during pile driving and removal must be conducted by NMFS-approved PSOs 
in a manner consistent with the following:
     Independent PSOs (i.e., not construction personnel) who 
have no other assigned tasks during monitoring periods must be used;
     Other PSOs may substitute education (degree in biological 
science or related field) or training for experience; and
     WADOT must submit PSO Curriculum Vitae for approval by 
NMFS prior to the onset of pile driving.
    PSOs must have the following additional qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    Up to four PSOs will be employed. PSO locations will provide an 
unobstructed view of all water within the shutdown zone, and as much of 
the Level A and Level B harassment zones as possible. PSO locations are 
as follows:
    (1) At the pile driving/removal site or best vantage point 
practicable to monitor the shutdown zones and the small area north into 
Burley Lagoon;
    (2) At Purdy Spit Park to monitor the Level B harassment zone near 
the project site in Henderson Bay; and
    (3) For the smaller Level B harassment zone associated with H pile 
driving/removal, an additional PSOs will be located on the southeast 
end of the level B harassment zone (see Monitoring Plan Figure 4);
    (4) For the larger Level B harassment zone associated with 
sheetpile driving/removal PSOs will be at the pile/driving removal site 
and Purdy Spit park as described above. Two additional PSOs will be 
located further south in Henderson Bay (see Monitoring Plan Figure 2): 
One at Kopachuck State Park to monitor the southern end of the Level B 
harassment zone and one further south at Penrose Point State Park to 
monitor the approaches into Henderson Bay, especially for killer and 
humpback whales and other large whales not authorized for take.
    Monitoring will be conducted 30 minutes before, during, and 30 
minutes after pile driving/removal 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 
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 or drilling equipment is no more than 30 minutes.

Reporting

    A draft marine mammal monitoring report will be submitted to NMFS 
within 90 days after the completion of pile driving and removal 
activities, or 60 days prior to a requested date of issuance of any 
future IHAs for projects at the same location, whichever comes first. 
The report will include an overall description of work completed, a 
narrative regarding marine mammal sightings, and associated PSO data 
sheets. Specifically, the report must include:
     Dates and times (begin and end) of all marine mammal 
monitoring.
     Construction activities occurring during each daily 
observation period, including how many and what type of piles were 
driven or removed and by what method (i.e., impact or vibratory and if 
other removal methods were used).
     Weather parameters and water conditions during each 
monitoring period (e.g., wind speed, percent cover, visibility, sea 
state).
     The number of marine mammals observed, by species, 
relative to the pile location and if pile driving or removal was 
occurring at time of sighting.
     Age and sex class, if possible, of all marine mammals 
observed.
     PSO locations during marine mammal monitoring.
     Distances and bearings of each marine mammal observed to 
the pile being driven or removed for each sighting (if pile driving or 
removal was occurring at time of sighting).
     Description of any marine mammal behavior patterns during 
observation, including direction of travel and estimated time spent 
within the Level A and Level B harassment zones while the source was 
active.
     Number of individuals of each species (differentiated by 
month as appropriate) detected within the monitoring zone, and 
estimates of number of marine mammals taken, by species (a correction 
factor may be applied to total take numbers, as appropriate).
     Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensued, and resulting behavior of the animal, if 
any.
     Description of attempts to distinguish between the number 
of individual animals taken and the number of incidences of take, such 
as ability to track groups or individuals.
    If no comments are received from NMFS within 30 days, the draft 
final report will constitute the final report. If comments are 
received, a final report addressing NMFS comments must be submitted 
within 30 days after receipt of comments.

Reporting Injured or Dead Marine Mammals

    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, WADOT shall report the 
incident to the Office of Protected Resources (OPR), NMFS and to the 
regional stranding coordinator as soon as feasible. If the death or 
injury was clearly caused by the specified activity, WADOT must 
immediately cease the specified activities until NMFS is able to review 
the circumstances of the incident and determine what, if any, 
additional measures are appropriate to ensure compliance with the terms 
of the IHA. The IHA-holder must not resume their activities until 
notified by NMFS. The report must include the following information:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;

[[Page 81903]]

     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and
     General circumstances under which the animal was 
discovered.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    To avoid repetition, the discussion of our analyses applies to all 
the species listed in Table 9, given that the anticipated effects of 
this activity on these different marine mammal stocks are expected to 
be similar. There is little information about the nature or severity of 
the impacts, or the size, status, or structure of any of these species 
or stocks that would lead to a different analysis for this activity. 
Pile driving activities have the potential to disturb or displace 
marine mammals. Specifically, the project activities may result in 
take, in the form of Level B harassment from underwater sounds 
generated from pile driving and removal and needle gun use. Potential 
takes could occur if individuals are present in the ensonified zone 
when these activities are underway.
    Takes by Level B harassment would be in the form of behavioral 
disturbance and/or TTS. No mortality or PTS (Level A harassment) is 
anticipated given the nature of the activity and measures designed to 
minimize the possibility of injury to marine mammals. The potential for 
harassment is minimized through the construction method and the 
implementation of the planned mitigation measures (see Proposed 
Mitigation section).
    The nature of the pile driving project precludes the likelihood of 
serious injury or mortality. Take would occur within a limited, 
confined area (north-central Henderson Bay) of the stock's range. Level 
A and Level B harassment will be reduced to the level of least 
practicable adverse impact through use of mitigation measures described 
herein, and as a result, as discussed above, Level A harassment is not 
anticipated to occur. Further the amount of take proposed to be 
authorized is extremely small when compared to stock abundance.
    Behavioral responses of marine mammals to pile driving and needle 
gun use at the project site, if any, are expected to be mild and 
temporary. Marine mammals within the Level B harassment zone may not 
show any visual cues they are disturbed by activities (as noted during 
modification to the Kodiak Ferry Dock) or could become alert, avoid the 
area, leave the area, or display other mild responses that are not 
observable such as changes in vocalization patterns. Given the short 
duration of noise-generating activities per day and that pile driving 
and removal would occur across three months, any harassment would be 
temporary. There are no other areas or times of known biological 
importance for any of the affected species.
    In addition, it is unlikely that minor noise effects in a small, 
localized area of habitat would have any effect on the fitness of any 
individual or 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.
    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 or Level A harassment is anticipated or 
authorized.
     No biologically important areas have been identified 
within the project area.
     For all species, Henderson Bay is a very small and 
peripheral part of their range.
     WADOT would implement mitigation measures such as shut 
downs and slow removal of piles to minimize turbidity and shaking the 
pile slightly prior to removal (wake up) to break the bond with 
surrounding sediment to avoid pulling out large blocks of sediment.
     Monitoring reports from similar work in Puget Sound have 
documented little to no effect on individuals of the same species 
impacted by the specified activities.
    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 section 101(a)(5)(D) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers and so, in practice, where estimated numbers are 
available, NMFS compares the number of individuals taken to the most 
appropriate estimation of abundance of the relevant species or stock in 
our determination of whether an authorization is limited to small 
numbers of marine mammals. When the predicted number of individuals to 
be taken is fewer than one third of the species or stock abundance, the 
take is considered to be of small numbers. Additionally, other 
qualitative factors may be considered in the analysis, such as the 
temporal or spatial scale of the activities.
    The amount of take NMFS proposes to authorize is below one third of 
the estimated stock abundance for all stocks. For harbor seals there 
are no official estimates of the stock size. We do know the populations 
of harbor seals in Puget Sound are increasing and number at least 
32,000 (Jeffries, 2013). We also know that harbor seals do not

[[Page 81904]]

generally range over large areas (see above). Therefore, it is most 
likely that the number of harbor seal takes is a small number. For all 
stocks, these are all likely conservative estimates of percent of stock 
taken because they assume all takes are of different individual animals 
which is likely not the case. Some individuals may return multiple 
times in a day, but PSOs would count them as separate takes if they 
cannot be individually identified.
    Based on the analysis contained herein of the 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 
determined that the total taking of affected species or stocks would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

Endangered Species Act

    Section 7(a)(2) of the 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 West Coast Region Protected Resources Division Office, 
whenever we propose to authorize take for endangered or threatened 
species.
    No incidental take of ESA-listed species is proposed for 
authorization or expected to result from this activity. Therefore, NMFS 
has determined that formal consultation under section 7 of the ESA is 
not required for this action.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to the WADOT to conduct the Purdy Bridge Rehabilitation 
project in Pierce, WA from July 16, 2021 through September 30, 2021, 
provided the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated. A draft of the proposed IHA can be found 
at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this notice of proposed IHA for the proposed Purdy 
Bridge Rehabilitation project. We also request at this time comment on 
the potential renewal of this proposed IHA as described in the 
paragraph below. Please include with your comments any supporting data 
or literature citations to help inform decisions on the request for 
this IHA or a subsequent Renewal IHA.
    On a case-by-case basis, NMFS may issue a one-time 1-year Renewal 
IHA following notice to the public providing an additional 15 days for 
public comments when (1) up to another year of identical, or nearly 
identical, activities as described in the Description of Proposed 
Activity section of this notice is planned or (2) the activities as 
described in the Description of Proposed Activity section of this 
notice would not be completed by the time the IHA expires and a Renewal 
would allow for completion of the activities beyond that described in 
the Dates and Duration section of this notice, provided all of the 
following conditions are met:
     A request for renewal is received no later than 60 days 
prior to the needed Renewal IHA effective date (recognizing that 
Renewal IHA expiration date cannot extend beyond one year from 
expiration of the initial IHA);
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
requested Renewal IHA 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); 
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; and
     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: December 14, 2020.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2020-27787 Filed 12-16-20; 8:45 am]
BILLING CODE 3510-22-P