Notice2024-07338
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Terminal 4 Expansion and Redevelopment Project at the Port of Grays Harbor, Washington
Primary source
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Published
April 8, 2024
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from Ag Processing Inc. (AGP) for authorization to take marine mammals incidental to the Terminal 4 (T4) Expansion and Redevelopment Project (Project) at the Port of Grays Harbor (Port) in both the City of Aberdeen and City of Hoquiam, Grays Harbor County, Washington. 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-time, 1-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 authorization and agency responses will be summarized in the final notice of our decision.
Full Text
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<title>Federal Register, Volume 89 Issue 68 (Monday, April 8, 2024)</title>
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[Federal Register Volume 89, Number 68 (Monday, April 8, 2024)]
[Notices]
[Pages 24436-24455]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-07338]
[[Page 24436]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XD824]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the Terminal 4 Expansion and
Redevelopment Project at the Port of Grays Harbor, Washington
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 Ag Processing Inc. (AGP) for
authorization to take marine mammals incidental to the Terminal 4 (T4)
Expansion and Redevelopment Project (Project) at the Port of Grays
Harbor (Port) in both the City of Aberdeen and City of Hoquiam, Grays
Harbor County, Washington. 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-time, 1-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 authorization and agency
responses will be summarized in the final notice of our decision.
DATES: Comments and information must be received no later than May 8,
2024.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources, NMFS
and should be submitted via email to <a href="/cdn-cgi/l/email-protection#92dbc6c2bcc2f3e7fefbfcf7d2fcfdf3f3bcf5fde4"><span class="__cf_email__" data-cfemail="4e071a1e601e2f3b2227202b0e20212f2f60292138">[email protected]</span></a>. 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:
<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</a>. In case of
problems accessing these documents, please call the contact listed
below.
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, including all attachments, must
not exceed a 25-megabyte file size. All comments received are a part of
the public record and will generally be posted online at <a href="https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act">https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</a> 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: Robert Pauline, Office of Protected
Resources, NMFS, (301) 427-8401.
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 proposed or, if the taking is limited to harassment, a notice of a
proposed IHA is 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 NAO 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 May 12, 2023, NMFS received a request from AGP for an IHA to
take marine mammals incidental to construction activities in the City
of Aberdeen and City of Hoquiam, Grays Harbor County, Washington.
Following NMFS' review of the application, AGP submitted a revised
version on August 4, 2023. The application was deemed adequate and
complete on February 20, 2024. AGP's request is for take of harbor
seal, California sea lion, Steller sea lion and harbor porpoise by
Level B harassment and, for harbor seal and harbor porpoise, by Level A
harassment. Neither AGP nor NMFS expect serious injury or mortality to
result from this activity and, therefore, an IHA is appropriate.
Description of Proposed Activity
Overview
AGP would work in partnership with the Port to construct a new
export terminal at T4. AGP and the Port would each undertake separate
stages of the construction; however, the IHA, if issued, would be held
by AGP as the responsible party, and would authorize take associated
with the combined specified activity, with AGP acting on behalf of the
Port for that portion. The activity includes removal of existing piles
and the installation of both temporary and permanent piles of various
sizes. The construction would occur for 105 days, which would occur
intermittently over the in-water work window (discussed below). Takes
of marine mammals by Level A and Level B harassment would occur due to
both
[[Page 24437]]
impact and vibratory pile driving and vibratory removal. The purpose of
the project is to expand T4 and redevelop adjacent parcels to increase
rail and shipping capacity at the Port in order to accommodate growth
of dry bulk, breakbulk, and roll-on/roll-off cargos.
Dates and Duration
This IHA would be valid for one year from July 16, 2024 through
July 15, 2025. Due to in-water work timing restrictions to protect
Endangered Species Act (ESA)-listed salmonids, all planned in-water
construction including pile removal and installation is limited to a
work window from July 16 through February 15. Pile driving would be
completed intermittently throughout the daylight hours. All pile
driving is expected to be completed during one season of construction.
Specific Geographic Region
The Project site is situated in both the City of Aberdeen and City
of Hoquiam, Grays Harbor County, Washington in Township 17 North, Range
9 West, section 17, near where the Chehalis River enters Grays Harbor
(figure 1). Land use in the Aberdeen area is a mix of residential,
commercial, industrial, and open space and/or undeveloped lands.
[GRAPHIC] [TIFF OMITTED] TN08AP24.018
Detailed Description of the Specified Activity
The T4 Project in-water work will include upgrades to the fender
system on the T4 dock and the installation of a ship loader facility.
The existing timber-piled fender system at the Terminal 4 Berth A (T4A)
will be replaced with a modern pile-supported panel system and a modern
suspended panel system at Berth B (T4B). Terminal 4's Berths A and B
have distinctly different structural systems, necessitating piles to
support the fender system at Berth A but not at Berth B. The new fender
system will consist of a series of steel fender panels, each supported
by one or more steel pipe piles at each fender location along T4A and
supported by the existing deck only along T4B.
The proposed Project consists of vibratory pile driving
installation and removal and impact pile installation. Existing piles
will be removed from the substrate using the direct pull method. If
direct pulling is unsuccessful, vibratory extraction will be used.
Vibratory extractors are commonly used to remove steel pile where
sediments allow. The vibratory hammer is mounted to the top of the
pile, and the pile is then vibrated between 1,200 and 2,400 vibrations
per minute. The vibrations liquefy and loosen the sediment surrounding
the pile, allowing it to be removed with an upward lift from the crane.
Broken or damaged piles that cannot be removed by either the vibratory
hammer or direct pull will be cut off at or below the mudline. Based on
the substrate conditions at the site, it is anticipated that most of
the existing timber piles will be removed by direct pull. However, for
the purposes of estimating take it is assumed they would all be subject
to vibratory removal. The Project will include the removal of up to:
<bullet> 50, 18-inch timber piles
<bullet> 6, 12-inch steel H-piles
<bullet> 27, 16.5-inch pre-stressed concrete octagonal sections
[[Page 24438]]
New and replacement piles will be installed with a vibratory hammer
or combination of a vibratory hammer and impact hammer. Impact pile
driving would be avoided to the extent feasible. Piles will be aligned
with steel templates to ensure the correct position of the piles
relative to each other. The proposed Project will also include
installation of up to:
<bullet> 50, 36-inch steel pipe piles
<bullet> 24, 24-inch steel pipe piles
<bullet> 6, 12-inch steel H-sections
<bullet> 15, 18-inch steel pipe piles,
<bullet> 24, 24 to 30-inch steel pipe piles.
Additionally, a total of up to 24 temporary 24-inch steel piles may
be installed for temporary construction use or to address unforeseen
conditions. The temporary piles will be placed and removed as
necessary. A summary of the proposed pile removal and installation
methods for the dock upgrades and the ship loader facility are
presented below in table 1 and table 2.
Table 1--Planned In-Water Pile Removal and Installation for T4 Dock Upgrades
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Removal/install Total days of Impact strikes per
Location Pile type and size Activity method Number of piles operation Piles per day Hours vib install pile
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Permanent Piles
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Terminal 4A and 4B.............. Up to 18-inch Removal........... Vibratory hammer, Up to 50.......... Up to 12.......... Up to 10.......... Up to 5.0/day or None.
timber piles. direct pull. ~0.5/pile.
Terminal 4B..................... 18-inch steel pipe Installation...... Vibratory hammer.. Up to 15.......... Up to 6........... Up to 6........... Up to 3.0/day or None.
pile. ~0.5/pile.
Terminal 4A..................... 24- to 30-inch Installation...... Vibratory hammer.. Up to 24.......... Up to 18.......... Up to 6........... Up to 6.0/day or None.
steel pipe pile. ~1.0/pile.
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Table 2--In-Water Pile Removal and Installation for New AGP Export Terminal, Shiploader
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Install/removal Total days of Avg. hours Impact strikes per
Location Pile type and size Activity method Number of piles operation Piles per day vibratory per pile pile
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Permanent Piles
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Terminal 4B..................... 12-inch steel H Removal........... Vibratory hammer Up to 6........... Up to 3........... Up to 3........... Up to 1.5/day or None.
sections. or direct pull. ~0.5/pile.
Terminal 4B..................... 16.5-inch concrete Removal........... Vibratory hammer, Up to 27.......... Up to 9........... Up to 8........... Up to 8/day or None.
octagonal pile. direct pull. ~1.0/pile.
Terminal 4B..................... 36-inch-diameter Install........... Vibratory and Up to 50.......... Up to 30.......... Up to 4........... Up to 8/day or ~2/ Up to 2,400/day or
steel pipe pile. impact hammer. pile. ~600/pile.
Terminal 4B..................... New 24-inch steel Install........... Vibratory and Up to 24.......... Up to 12.......... Up to 4........... Up to 6/day or Up to 2,000/day or
pipe pile. impact hammer. ~1.5/pile. ~500/pile.
Terminal 4B..................... 12-inch steel H- Install........... Vibratory hammer.. Up to 6........... Up to 3........... Up to 3........... Up to 1.5/day or None.
piles. ~0.5/pile.
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Temporary Piles
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Terminal 4B..................... 24-inch steel pipe Install........... Vibratory hammer.. Up to 24.......... Up to 6........... Up to 8........... Up to 4/day or None.
pile. ~0.5/pile.
Terminal 4B..................... 24-inch steel pipe Removal........... Vibratory hammer.. Up to 24.......... Up to 6........... Up to 8........... Up to 4/day or None.
pile. ~0.5/pile.
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Above water construction would include rail upgrades and T4 cargo
yard relocation and expansion which would all occur landward of the
Grays Harbor shoreline.
This above-water work is not expected to result in any take of
marine mammals. Noise generated above the water would not be
transmitted into the water to the degree that resulting underwater
noise would be expected to cause disturbance and, none of the pinniped
haulouts are located close enough to the project area to cause
disturbance. Therefore, airborne noise is not considered further in
this document.
Proposed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see Proposed
Mitigation and Proposed Monitoring and Reporting).
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history of the potentially affected species. NMFS
fully considered all of this information, and we refer the reader to
these descriptions, instead of reprinting the information. Additional
information regarding population trends and threats may be found in
NMFS' Stock Assessment Reports (SARs; <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and
more general information about these species (e.g., physical and
behavioral descriptions) may be found on NMFS' website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 3 lists all species or stocks for which take is expected and
proposed to be authorized for this activity and summarizes information
related to the population or stock, including regulatory status under
the MMPA and ESA and potential biological removal (PBR), where known.
PBR is defined by the MMPA as the maximum number of animals, not
including natural mortalities, that may be removed from a marine mammal
stock while allowing that stock to reach or maintain its optimum
sustainable population (as described in NMFS' SARs). While no serious
injury or mortality is anticipated or proposed to be authorized here,
PBR and annual serious injury and mortality from anthropogenic sources
are included here as gross indicators of the status of the species or
stocks and other threats.
Marine mammal abundance estimates presented in this document
represent
[[Page 24439]]
the total number of individuals that make up a given stock or the total
number estimated within a particular study or survey area. NMFS' stock
abundance estimates for most species represent the total estimate of
individuals within the geographic area, if known, that comprises that
stock. For some species, this geographic area may extend beyond U.S.
waters. All managed stocks in this region are assessed in NMFS' Alaska
and Pacific SARs. All values presented in table 3 are the most recent
available at the time of publication (including from the draft 2023
SARs) and are available online at: (<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports</a>).
Table 3--Species Likely Impacted by the Specified Activities \1\
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ESA/MMPA status; Stock abundance (CV,
Common name Scientific name Stock Strategic (Y/N) Nmin, most recent PBR Annual M/
\2\ abundance survey)\3\ SI \4\
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Odontoceti (toothed whales, dolphins, and porpoises)
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Family Phocoenidae (porpoises):
Harbor porpoise................. Phocoena phocoena...... Northern Oregon/, -,-; N 22,074 (0.391, 16,068, 161 3.2
Washington Coast. 2022).
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Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and
sea lions):
California Sea Lion............. Zalophus californianus. U.S.................... -,-; N 257,606 (N/A, 233,515, 14,011 >321
2014).
Steller Sea Lion................ Eumetopias jubatus..... Eastern................ -,-; N 36,308 (N/A, 36,308, 2,178 93.2
2022).
Family Phocidae (earless seals):
Harbor Seal..................... Phoca vitulina......... Oregon/Washington -, -, N 24,731\5\ (1999)...... UNK 10.6
Coastal Stock.
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\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
(<a href="https://www.marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/">https://www.marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/</a>;).
\2\ 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.
\3\ NMFS marine mammal stock assessment reports online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a> assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\4\ 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, vessel strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range.
\5\ There is no current estimate of abundance available for this stock. Value presented is the most recent available and based on 1999 data.
As indicated above, all four species (with four managed stocks) in
table 3 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur. While killer whales
(Orcincus orca), humpback whales (Megaptera novaeangilae), gray whales
(Eschrichtius robustus), and minke whales (Balaenoptera acutorostrada)
have been sighted in Grays Harbor, the temporal and/or spatial
occurrence of these species is such that take is not expected to occur.
Furthermore, if any of these species are sighted approaching Level B
harassment zones, construction activities would be shut down in order
to avoid harassment. Therefore, take is not expected for these species
and they are not discussed further in this document.
Harbor Porpoise
In the eastern North Pacific Ocean, harbor porpoise are found in
coastal and inland waters from Point Barrow, along the Alaskan coast,
and down the west coast of North America to Point Conception,
California (Gaskin, 1984). Harbor porpoise are known to occur year-
round in the inland trans-boundary waters of Washington and British
Columbia, Canada (Osborne et al., 1988), and along the Oregon/
Washington coast (Barlow, 1988; Barlow et al., 1988, Green et al,.
1992). Little information exists on harbor porpoise movements and stock
structure in Grays Harbor. Hall (2004) found that the frequency of
sightings of harbor porpoises decreased with increasing depths beyond
150 meters, with the highest numbers observed at water depths ranging
from 61 to 100 meters. Although harbor porpoises have been spotted in
deep water, they tend to remain in shallower shelf waters (less than
150 meters), where they are most often observed in small groups of few
individuals (Baird, 2003). Stranding incidents in the area have been
rare.
California Sea Lion
California sea lions are found from Vancouver Island, British
Columbia, to the southern tip of Baja, California. California Sea lions
breed on the offshore islands of southern and central California from
May through July (Heath and Perrin, 2008). The California sea lion is
the most frequently sighted pinniped found in Washington waters and
uses haulout sites located on jetties, offshore rocks and islands, log
booms, marina docks, and navigation buoys. Only male California sea
lions migrate into Pacific Northwest waters, with females remaining in
waters near their breeding rookeries off the coast of California and
Mexico. The California sea lion was considered rare in Washington
waters prior to the 1950s.
The nearest documented California sea lion haulout sites to the
Project site are at the Westport Docks, approximately 13 miles west of
the Project site near the entrance to Grays Harbor (Jeffries et al.
2015), and another haulout observed in 1997 referred to as the mid-
harbor flats located approximately 5.65 miles west of the Project site
(Washinton Department of Fish and Wildlife (WDFW), 2022). During six
aerial surveys conducted in 2014 and 2015, a total of 113 California
sea lions were observed in Grays Harbor on the Westport docks (Jeffries
et al., 2015). Occurrences of California sea lion strandings have been
rare near the project area.
Steller Sea Lion
Steller sea lions range from southeast Alaska to central
California, including
[[Page 24440]]
Washington. The species prefers beaches, ledges, and rocky reefs for
breeding and hauling out (NMFS 2023c). In Washington, Steller sea lions
occur mainly along the outer coast from the Columbia River to Cape
Flattery (Jeffries et al., 2000). Smaller numbers use the Strait of
Juan de Fuca, the San Juan Islands, and Puget Sound south to about the
Nisqually River mouth in Thurston and Pierce counties (Wiles, 2015).
The Eastern Depleted Population Segment (DPS) of Steller sea lions has
historically bred on rookeries located in Southeast Alaska, British
Columbia, Oregon, and California. However, within the last several
years, a new rookery has become established on the outer Washington
coast at the Carroll Island and Sea Lion Rock complex (M.M. Muto et
al., 2021). Most pups (86 percent) are born in rookeries in southeast
Alaska and British Columbia (Wiles, 2015). Steller sea lions occupy 22
haulouts in Washington, the largest of which are on the outer Olympic
coast (Wiles, 2015).
WDFW Priority Habitat and Species Data does not indicate any
observances of Steller sea lions in Grays Harbor (WDFW, 2022). The
nearest documented Steller sea lion haulout sites to the Project site
are at Split Rock, 35 miles north of the entrance to Grays Harbor, and
at the mouth of the Columbia River, 46 miles south of the entrance to
Grays Harbor (Jeffries et al., 2000). A few Steller sea lions may haul
out on buoys near the Westport marina, located 13 miles west of the
Project site, or at Westport docks, similar to California sea lions.
Steller sea lion strandings have been rare near the project area.) No
other confirmed Steller sea lion observations have been located
specific to Grays Harbor.
Harbor Seal
Harbor seals inhabit coastal and estuarine waters off Baja
California, north along the western coasts of the continental U.S.,
British Columbia, and southeast Alaska, west through the Gulf of Alaska
and Aleutian Islands, and in the Bering Sea north to Cape Newenham and
the Pribilof Islands (Carretta et al., 2014). They haul out on rocks,
reefs, beaches, and drifting glacial ice and feed in marine, estuarine,
and occasionally fresh waters. Harbor seals generally are non-
migratory, with local movements associated with such factors as tides,
weather, season, food availability, and reproduction (Fisher, 1952;
Bigg 1969, 1981). Harbor seals are the only pinniped species that
occurs year-round and breeds in Washington waters. Pupping seasons vary
by geographic region, with pups born in coastal estuaries (Columbia
River, Willapa Bay, and Grays Harbor) from mid-April through June
(Jeffries et al., 2000). According to WDFW's atlas of seal and sea lion
haulout sites (Jeffries et al., 2000), all haulouts in Grays Harbor are
associated with tidal flats; at high tide it is assumed that these
animals are foraging elsewhere in the estuary. The nearest documented
harbor seal haulout site to the Project site is a low-tide haulout
located 6 miles to the west.
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. 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, 2019) recommended that marine mammals be divided into hearing
groups based on directly measured (behavioral or auditory evoked
potential techniques) or estimated hearing ranges (behavioral response
data, anatomical modeling, etc.). Note that no direct measurements of
hearing ability have been successfully completed for mysticetes (i.e.,
low-frequency cetaceans). Subsequently, NMFS (2018) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65
decibel (dB) threshold from the normalized composite audiograms, with
the exception for lower limits for low-frequency cetaceans where the
lower bound was deemed to be biologically implausible and the lower
bound from Southall et al. (2007) retained. Marine mammal hearing
groups and their associated hearing ranges are provided in table 4.
Table 4--Marine Mammal Hearing Groups
[NMFS, 2018]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans 150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
whales, bottlenose whales).
High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
Cephalorhynchid, Lagenorhynchus
cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) 50 Hz to 86 kHz.
(true seals).
Otariid pinnipeds (OW) (underwater) 60 Hz to 39 kHz.
(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 et al.,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section provides a discussion of the ways in which components
of the specified activity may impact marine mammals and their habitat.
The Estimated Take of Marine Mammals 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 of Marine Mammals section, and the Proposed Mitigation
section, to draw conclusions regarding the likely impacts of these
activities on the reproductive success or survivorship
[[Page 24441]]
of individuals and whether those impacts are reasonably expected to, or
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival.
Description of Sounds Sources
The marine soundscape is comprised of both ambient and
anthropogenic sounds. Ambient sound is defined as the all-encompassing
sound in a given place and is usually a composite of sound from many
sources both near and far. The sound level of an area is defined by the
total acoustical energy being generated by known and unknown sources.
These sources may include physical (e.g., waves, wind, precipitation,
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced
by marine mammals, fish, and invertebrates), and anthropogenic sound
(e.g., vessels, dredging, aircraft, construction).
The sum of the various natural and anthropogenic sound sources at
any given location and time--which comprise ``ambient'' or
``background'' sound--depends not only on the source levels (as
determined by current weather conditions and levels of biological and
shipping activity) but also on the ability of sound to propagate
through the environment. In turn, sound propagation is dependent on the
spatially and temporally varying properties of the water column and sea
floor, and is frequency-dependent. As a result of the dependence on a
large number of varying factors, ambient sound levels can be expected
to vary widely over both coarse and fine spatial and temporal scales.
Sound levels at a given frequency and location can vary by 10 to 20 dB
from day to day (Richardson et al., 1995). The result is that,
depending on the source type and its intensity, sound from the
specified activity may be a negligible addition to the local
environment or could form a distinctive signal that may affect marine
mammals.
In-water construction activities associated with the project would
include impact pile driving, vibratory pile driving, and vibratory pile
removal. The sounds produced by these activities fall into one of two
general sound types: impulsive and non-impulsive. Impulsive sounds
(e.g., explosions, gunshots, sonic booms, impact pile driving) are
typically transient, brief (less than 1 second), broadband, and consist
of high peak sound pressure with rapid rise time and rapid decay (ANSI,
1986; NIOSH, 1998; ANSI, 2005; NMFS, 2018). Non-impulsive sounds (e.g.,
aircraft, machinery operations such as drilling or dredging, vibratory
pile driving, and active sonar systems) can be broadband, narrowband or
tonal, brief or prolonged (continuous or intermittent), and typically
do not have the high peak sound pressure with raid rise/decay time that
impulsive sounds do (ANSI, 1995; NIOSH, 1998; NMFS, 2018). The
distinction between these two sound types is important because they
have differing potential to cause physical effects, particularly with
regard to hearing (e.g., Southall et al., 2007).
Two types of pile hammers would be used on this project: impact and
vibratory. Impact hammers operate by repeatedly dropping a heavy piston
onto a pile to drive the pile into the substrate. Sound generated by
impact hammers is characterized by rapid rise times and high peak
levels, a potentially injurious combination (Hastings and Popper,
2005). Vibratory hammers install piles by vibrating them and allowing
the weight of the hammer to push them into the sediment. Vibratory
hammers produce significantly less sound than impact hammers. Peak
sound pressure levels (SPLs) may be 180 dB or greater, but are
generally 10 to 20 dB lower than SPLs generated during impact pile
driving of the same-sized pile (Oestman et al., 2009). Rise time is
slower, reducing the probability and severity of injury, and sound
energy is distributed over a greater amount of time (Nedwell and
Edwards, 2002; Carlson, et al., 2005).
The likely or possible impacts of the AGP's proposed activity on
marine mammals could involve both non-acoustic and acoustic stressors.
Potential non-acoustic stressors include the physical presence of the
equipment and personnel; however, any impacts to marine mammals are
expected to primarily be acoustic in nature.
Auditory Effects
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 AGP's specified activity. In
general, animals exposed to natural or anthropogenic sound may
experience physical and behavioral effects, ranging in magnitude from
none to severe (Southall et al., 2007, 2021). Exposure to pile driving
noise has the potential to result in auditory threshold shifts (TS) 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., 2004;
Southall et al., 2007). Here we discuss physical auditory effects (TSs)
followed by behavioral effects and potential impacts on habitat.
NMFS defines a noise-induced 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 (Ward et al., 1958, 1959; Ward, 1960;
Kryter et al., 1966; Miller, 1974; Ahroon et al., 1996; Henderson et
al., 2008). PTS levels for marine mammals are estimates, as with the
exception of a single study unintentionally inducing PTS in a harbor
seal (Kastak et al., 2008), there are no empirical data measuring PTS
in marine mammals largely due to the fact that, for various ethical
reasons, experiments involving anthropogenic noise exposure at levels
inducing PTS
[[Page 24442]]
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
(Southall et al., 2007), a TTS of 6 dB is considered the minimum
threshold shift clearly larger than any day-to-day or session-to-
session variation in a subject's normal hearing ability (Schlundt et
al., 2000; Finneran et al., 2000, 2002). As described in Finneran
(2015), marine mammal studies have shown the amount of TTS increases
with cumulative sound exposure level (SELcum) in an accelerating
fashion: At low exposures with lower SELcum, the amount of TTS is
typically small and the growth curves have shallow slopes. At exposures
with higher SELcum, the growth curves become steeper and approach
linear relationships with the noise SEL.
Depending on the degree (elevation of threshold in dB), duration
(i.e., recovery time), and frequency range of TTS, and the context in
which it is experienced, TTS can have effects on marine mammals ranging
from discountable to serious (similar to those discussed in auditory
masking, below). For example, a marine mammal may be able to readily
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal
is traveling through the open ocean, where ambient noise is lower and
there are not as many competing sounds present. Alternatively, a larger
amount and longer duration of TTS sustained during time when
communication is critical for successful mother/calf interactions could
have more serious impacts. We note that reduced hearing sensitivity as
a simple function of aging has been observed in marine mammals, as well
as humans and other taxa (Southall et al., 2007), so we can infer that
strategies exist for coping with this condition to some degree, though
likely not without cost.
Currently, TTS data only exist for four species of cetaceans
(bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus
leucas), harbor porpoise, and Yangtze finless porpoise (Neophocoena
asiaeorientalis)) and five species of pinnipeds exposed to a limited
number of sound sources (i.e., mostly tones and octave-band noise) in
laboratory settings (Finneran, 2015). TTS was not observed in trained
spotted (Phoca largha) and ringed (Pusa hispida) seals exposed to
impulsive noise at levels matching previous predictions of TTS onset
(Reichmuth et al., 2016). In general, harbor seals and harbor porpoises
have a lower TTS onset than other measured pinniped or cetacean species
(Finneran, 2015). Additionally, the existing marine mammal TTS data
come from a limited number of individuals within these species. No data
are available on noise-induced hearing loss for mysticetes. For
summaries of data on TTS in marine mammals or for further discussion of
TTS onset thresholds, please see Southall et al. (2007), Finneran and
Jenkins (2012), Finneran (2015), and table 5 in NMFS (2018).
Installing piles requires a combination of impact pile driving and
vibratory pile driving. For the project, these activities would not
occur at the same time and there would likely be pauses in activities
producing the sound during each day. Given these pauses and that many
marine mammals are likely moving through the action area and not
remaining for extended periods of time, the potential for TS declines.
Behavioral Harassment--Exposure to noise from pile driving and
removal also has the potential to behaviorally disturb marine mammals.
Available studies show wide variation in response to underwater sound;
therefore, it is difficult to predict specifically how any given sound
in a particular instance might affect marine mammals perceiving the
signal. If a marine mammal does react briefly to an underwater sound by
changing its behavior or moving a small distance, the impacts of the
change are unlikely to be significant to the individual, let alone the
stock or population. However, if a sound source displaces marine
mammals from an important feeding or breeding area for a prolonged
period, impacts on individuals and populations could be significant
(e.g., Lusseau and Bejder, 2007; Weilgart, 2007; NRC, 2005, Southall et
al., 2021).
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, 2021; Weilgart, 2007; Archer et al., 2010). Behavioral reactions
can vary not only among individuals but also within exposures of an
individual, depending on previous experience with a sound source,
context, and numerous other factors (Ellison et al., 2012, Southall et
al., 2021), 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.
For a review of studies involving marine mammal behavioral responses to
sound, see Southall et al., 2007; Gomez et al., 2016; and Southall et
al., 2021 reviews.
Disruption of feeding behavior can be difficult to correlate with
anthropogenic sound exposure, so it is usually inferred by observed
displacement from known foraging areas, the appearance of secondary
indicators (e.g., bubble nets or sediment plumes), or changes in dive
behavior. As for other types of behavioral response, the frequency,
duration, and temporal pattern of signal presentation, as well as
differences in species sensitivity, are likely contributing factors to
differences in response in any given circumstance (e.g., Croll et al.,
2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko et al.,
2007). A determination of whether foraging disruptions incur fitness
consequences would require information on estimates of the energetic
requirements of the affected individuals and the relationship between
prey availability, foraging effort and success, and the life history
stage of the animal.
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
[[Page 24443]]
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. Grays
Harbor is home to a busy industrial port as well as large numbers small
private vessels that transit the area on a regular basis; therefore,
background sound levels in the bay are likely already elevated.
Marine Mammal Habitat Effects
AGP's construction activities could have localized, temporary
impacts on marine mammal habitat by increasing in-water SPLs and
slightly decreasing water quality. Construction activities are of short
duration and would likely have temporary impacts on marine mammal
habitat through increases in underwater sound. Increased noise levels
may affect acoustic habitat (see masking discussion above) and
adversely affect marine mammal prey in the vicinity of the project area
(see discussion below). During pile driving, elevated levels of
underwater noise would ensonify the Port where both fish and mammals
may occur and could affect foraging success.
In-water pile driving and pile removal would also cause short-term
effects on water quality due to increased turbidity. Local currents are
anticipated to disburse suspended sediments produced by project
activities at moderate to rapid rates depending on tidal stage. AGP
would employ standard construction best management practices, thereby
reducing any impacts. Considering the nature and duration of the
effects, combined with the measures to reduce turbidity, the impact
from increased turbidity levels is expected to be discountable.
Pile installation and removal may temporarily increase turbidity
resulting from suspended sediments. Any increases would be temporary,
localized, and minimal. AGP must comply with state water quality
standards during these operations by limiting the extent of turbidity
to the immediate project area. In general, turbidity associated with
pile installation is localized to about a 25-feet (ft) radius around
the pile (Everitt et al., 1980). Cetaceans are not expected to enter
the harbor and be close enough to the project pile driving areas to
experience effects of turbidity, and any pinnipeds would likely be
transiting the area and could avoid localized areas of turbidity.
Therefore, the impact from increased turbidity levels is expected to be
discountable to marine mammals. Furthermore, pile driving and removal
at the project site would not obstruct movements or migration of marine
mammals.
Effects on Prey
Construction activities would produce continuous (i.e., vibratory
pile driving) and impulsive (i.e., impact driving) sounds. Fish react
to sounds that are especially strong and/or intermittent low-frequency
sounds. Short duration, sharp sounds can cause overt or subtle changes
in fish behavior and local distribution. Hastings and Popper (2005)
identified several studies that suggest fish may relocate to avoid
certain areas of sound energy. Additional studies have documented
effects of pile driving on fish, although several are based on studies
in support of large, multiyear bridge construction projects (e.g.,
Scholik and Yan, 2001, 2002; Popper and Hastings, 2009). Sound pulses
at received levels may cause noticeable changes in behavior (Pearson et
al., 1992; Skalski et al., 1992). SPLs of sufficient strength have been
known to cause injury to fish and fish mortality.
Impacts on marine mammal prey (i.e., fish or invertebrates) of the
immediate area due to the acoustic disturbance are possible. The
duration of fish or invertebrate avoidance or other disruption of
behavioral patterns in this area after pile driving stops is unknown,
but a rapid return to normal recruitment, distribution and behavior is
anticipated. Further, significantly large areas of fish and marine
mammal foraging habitat are available in the nearby waters.
The duration of the construction activities is relatively short,
with pile driving and removal activities expected to take only 105
days. Each day, construction would occur for no more than 12 hours
during the day and pile driving activities would be restricted to
daylight hours. The most likely impact to fish from pile driving
activities at the project area would be temporary behavioral avoidance
of the area. In general, impacts to marine mammal prey species are
expected to be minor and temporary due to the short timeframe for the
project.
Construction activities, in the form of increased turbidity, have
the potential to adversely affect fish in the project area. Increased
turbidity is expected to occur in the immediate vicinity (on the order
of 10 ft (3 meters (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 fish are expected to be minor or
negligible. In addition, best management practices would be in effect,
which would limit the extent of turbidity to the immediate project
area.
In summary, given the relatively short daily duration of sound
associated with individual pile driving and events and the relatively
small areas being affected, pile driving activities associated with the
proposed action are not likely to have a permanent, adverse effect on
any fish habitat, or populations of fish species. Thus, we conclude
that impacts of the specified activity are not likely to have more than
short-term adverse effects on any prey habitat or populations of prey
species. Further, any impacts to marine mammal habitat are not expected
to result in significant or long-term consequences for individual
marine mammals, or to contribute to adverse impacts on their
populations.
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
proposed for authorization through the IHA, which will inform NMFS'
consideration of ``small numbers,'' the negligible impact
determinations, and impacts on subsistence uses.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes would primarily be by Level B harassment, as use
of the acoustic stressors (i.e., pile driving) has the potential to
result in disruption of behavioral patterns for individual
[[Page 24444]]
marine mammals. There is also some potential for auditory injury (Level
A harassment) to result, primarily for high frequency species (harbor
porpoise) and phocids (harbor seal). Auditory injury is unlikely to
occur for other species due to PTS zone sizes. The proposed mitigation
and monitoring measures are expected to minimize the severity of the
taking to the extent practicable.
As described previously, no serious injury or mortality is
anticipated or proposed to be authorized for this activity. Below we
describe how the proposed take numbers are estimated.
For acoustic impacts, 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) the number of days of activities. We note
that while these factors can contribute to a basic calculation to
provide an initial prediction of potential takes, additional
information that can qualitatively inform take estimates is also
sometimes available (e.g., previous monitoring results or average group
size). Below, we describe the factors considered here in more detail
and present the proposed take estimates.
Acoustic Thresholds
NMFS recommends the use of acoustic thresholds that identify the
received level of underwater sound above which exposed marine mammals
would be reasonably expected to be behaviorally harassed (equated to
Level B harassment) or to incur PTS of some degree (equated to Level A
harassment).
Level B Harassment--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 or exposure context (e.g., frequency, predictability, duty
cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., bathymetry, other noises in the area,
predators in the area), and the receiving animals (hearing, motivation,
experience, demography, life stage, depth) and can be difficult to
predict (e.g., Southall et al., 2007, 2021; Ellison et al., 2012).
Based on what the available science indicates and the practical need to
use a threshold based on a metric that is both predictable and
measurable for most activities, NMFS typically uses a generalized
acoustic threshold based on received level to estimate the onset of
behavioral harassment. NMFS generally predicts that marine mammals are
likely to be behaviorally harassed in a manner considered to be Level B
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile
driving, drilling) and above RMS SPL 160 dB (re 1 [mu]Pa) for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g.,
scientific sonar) sources. Generally speaking, Level B harassment take
estimates based on these behavioral harassment thresholds are expected
to include any likely takes by TTS as, in most cases, the likelihood of
TTS occurs at distances from the source less than those at which
behavioral harassment is likely. TTS of a sufficient degree can
manifest as behavioral harassment, as reduced hearing sensitivity and
the potential reduced opportunities to detect important signals
(conspecific communication, predators, prey) may result in changes in
behavior patterns that would not otherwise occur.
AGP's proposed activity includes the use of continuous (vibratory
driving and removal) and impulsive (impact pile driving) sources, and
therefore the RMS SPL thresholds of 120 and 160 dB re 1 [mu]Pa are
applicable.
Level A Harassment--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). AGP's
proposed activity includes the use of impulsive (impact pile driving)
and non-impulsive (vibratory pile driving and removal) sources.
These thresholds are provided in the table below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS' 2018 Technical Guidance, which may be accessed at:
<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Table 5--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 218 dB; Cell 8: LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has
a reference value of 1 [mu]Pa2s. In this table, thresholds are abbreviated to reflect American National
Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
[[Page 24445]]
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that are used in estimating the area ensonified above the
acoustic thresholds, including source levels and TL coefficient.
The sound field in the project area is the existing background
noise plus additional construction noise from the proposed project.
Marine mammals are expected to be affected via sound generated by the
primary components of the project (i.e., impact pile driving, vibratory
pile driving and removal). Additionally, vessel traffic and other
commercial and industrial activities in the project area may contribute
to elevated background noise levels which may mask sounds produced by
the project.
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 * Log<INF>10</INF> (R<INF>1</INF>/R<INF>2</INF>),
where
TL = transmission loss in dB
B = transmission loss coefficient
R<INF>1</INF> = the distance of the modeled SPL from the driven
pile, and
R<INF>2</INF> = the distance from the driven pile of the initial
measurement
This formula neglects loss due to scattering and absorption, which
is assumed to be zero here. The degree to which underwater sound
propagates away from a sound source is dependent on a variety of
factors, most notably the water bathymetry and presence or absence of
reflective or absorptive conditions including in-water structures and
sediments. Spherical spreading occurs in a perfectly unobstructed
(free-field) environment not limited by depth or water surface,
resulting in a 6-dB reduction in sound level for each doubling of
distance from the source (20*log[range]). Cylindrical spreading occurs
in an environment in which sound propagation is bounded by the water
surface and sea bottom, resulting in a reduction of 3 dB in sound level
for each doubling of distance from the source (10*log[range]). A
practical spreading value of 15 is often used under conditions, such as
the project site, where water increases with depth as the receiver
moves away from the shoreline, resulting in an expected propagation
environment that would lie between spherical and cylindrical spreading
loss conditions. Practical spreading loss is assumed here.
The intensity of pile driving sounds is greatly influenced by
factors such as the type of piles, hammers, and the physical
environment in which the activity takes place. In order to calculate
the distances to the Level A harassment and the Level B harassment
sound thresholds for the methods and piles being used in this project,
NMFS used acoustic monitoring data from other locations to develop
proxy source levels for the various pile types, sizes and methods. The
project includes vibratory and impact pile installation of steel and
vibratory removal of steel, timber piles, and concrete piles. Pile
sizes range from 12-in to 36-in. Source levels for the various pile
sizes and driving methods are presented in table 6. Bubble curtains
would be employed during all impact driving, with an assumed 5 dB
effective attenuation (Caltrans 2020).
Table 6--Proxy Sound Source Levels for Pile Sizes and Driving Methods
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Method and pile type Sound level at 10 m (dB rms)
-----------------------------------------------------------------
Vibratory hammer
----------------------------------------------------------------------------------------------------------------
36-inch steel piles (installation) \1\.......................... 170
30-inch steel pipe piles (installation) \2\..................... 159
24-inch steel piles (installation and removal) \3\.............. 154
18-inch steel pipe piles (installation) \4\..................... 158
12-inch steel H-piles (installation and removal) \5\............ 150
18-inch creosote timber piles (removal) \6\..................... 162
16.5-inch concrete octagonal sections (removal) \6\............. 163
----------------------------------------------------------------------------------------------------------------
Impact hammer dBrms dBSEL dBpeak
----------------------------------------------------------------------------------------------------------------
24-inch steel piles (single strike) \7\......................... 190 (185) 177 (172) 203 (198)
36-inch steel piles (single strike) \8\......................... 193 (188) 183 (178) 210 (205)
----------------------------------------------------------------------------------------------------------------
\1\ Laughlin 2012 as cited in WSDOT 2020.
\2\ 2023 NMFS Calculations based on data from Denes et al. 2016 (Auke Bay, Ketchikan, Kake), Edmonds Ferry
Terminal (Laughlin 2011, 2017), Colman Dock--Seattle Ferry Terminal (Laughlin 2012), Kodiak Pier 3 (PND
Engineers, 2015).
\3\ 2023 NMFS Calculations based on data from Naval Base Kitsap Bangor Test Pile (Navy (2012)) and EHW-2 (Navy
(2013)), Gustavus (Miner, 2020).
\4\ Caltrans 2020.
\5\ From generic value recommended in the Caltrans 2015 summary table, as it was representative of the data and
provided a citable data point and included projects from San Rafael, CA; Norfolk Naval Station, VA; Chevron
Long Wharf, CA; JEB Little Creek, Norfolk, VA.
\6\ Data not available, anticipated noise levels are based on available noise levels for the vibratory removal
of 20-inch diameter concrete piles (Naval Facilities Engineering Systems Command Southwest 2022). Noise levels
were back-calculated to a 10 meter measurement distance assuming a 15 log transmission loss. Based on prior
coordination with NMFS for the Johnson Pier Expansion and Dock Replacement Project IHA Request (M&N 2022) this
data source is an acceptable surrogate for timber piles (Pers. comm. Cara Hotchkin 2023).
\7\ From Caltrans 2015, pooled and averaged from 20 to 24'' piles from Stockton WWTP, CA; Bradshaw Bridge, CA;
Rodeo Dock, CA; Tongue Point Pier, OR; Cleer Creek WWTP, CA; SR 520 Test Pile, WA; Portland Light Rail, OR;
Port of Coeyman, NY; Pritchard Lake, CA; Amorco Wharf, CA; 5th Street Bridge, CA; Schuyler Heim Bridge, CA;
Tanana River, AK, NBK EHW2, WA; Crescent City, CA; Avon Wharf, CA; Orwood Bridge Replacement, CA; Tesoro
Amorco Wharf, CA; USCG Floating Dock, CA; Norfolk, VA; Plains Terminal, CA. A 5dB attenuation applied in
parenthesis for the use of a bubble curtain.
\8\ Caltrans 2020, unattenuated data used as reference. A 5dB attenuation applied in parenthesis for the use of
a bubble curtain.
Note: It is assumed that noise levels during vibratory pile installation and vibratory pile removal are similar.
The ensonified area associated with Level A harassment is more
technically challenging to predict due to the need to account for a
duration component. Therefore, NMFS developed an optional User
Spreadsheet tool to accompany the
[[Page 24446]]
Technical Guidance that can be used to relatively simply predict an
isopleth distance for use in conjunction with marine mammal density or
occurrence to help predict potential takes. We note that because of
some of the assumptions included in the methods underlying this
optional tool, we anticipate that the resulting isopleth estimates are
typically going to be overestimates of some degree, which may result in
an overestimate of potential take by Level A harassment. However, this
optional tool offers the best way to estimate isopleth distances when
more sophisticated modeling methods are not available or practical. For
stationary sources such as impact or vibratory pile driving and
removal, the optional User Spreadsheet tool predicts the distance at
which, if a marine mammal remained at that distance for the duration of
the activity, it would be expected to incur PTS. Inputs used for impact
driving in the optional User Spreadsheet tool, and the resulting
estimated isopleths, are reported below in table 7 and table 8 below.
Table 7--User Spreadsheet Inputs for Impact Driving
------------------------------------------------------------------------
Inputs 36-inch impact 24-inch impact
------------------------------------------------------------------------
Spreadsheet Tab Used.............. E.1) Impact Pile Driving (STATIONARY
SOURCE: Impulsive, Intermittent)
-------------------------------------
Source Level (Single Strike/shot 183 177
SEL).............................
Weighting Factor Adjustment (kHz). 2 2
Strikes per pile.................. 600 500
Piles Per day..................... 4 4
Propagation (xLogR)............... 15 15
Distance of source level 10 10
measurement (meters).............
------------------------------------------------------------------------
Table 8--Calculated Level A Harassment Zones, Impact Installation (m)
----------------------------------------------------------------------------------------------------------------
Level A threshold
--------------------------------------------------------
Pile type High- frequency
cetaceans 155 dB Phocid pinnipeds Otariid pinnipeds
SELcum 185 dB SELcum 203 db SELcum
----------------------------------------------------------------------------------------------------------------
36-inch steel piles (installation)..................... 990 445 33
24-inch steel piles, permanent (installation).......... 349 157 12
----------------------------------------------------------------------------------------------------------------
Table 9 shows the User Spreadsheet Inputs for vibratory driving and
the resulting Level A harassment zones are shown in table 10.
Calculated Level B harassment isopleths are found in table 11.
Table 9--User Spreadsheet Inputs for Vibratory Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
12-inch
24-to-30-in 24-in steel 24-in steel steel H- 18-in 16.5-inch
Inputs 36-in steel steel perm. temp. 18-in steel piles timber concrete
(install) (install) (install) (install and (install) (install and (removal) (removal)
removal) removal)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tab Used...................................... A.1) Vibratory Pile Driving (STATIONARY: Non-impulsive, Continuous)
---------------------------------------------------------------------------------------------------------
Source Level (RMS)............................ 170 159 154 154 158 150 162 163
---------------------------------------------------------------------------------------------------------
Weighting Factor Adjustment (kHz)............. 2.5
---------------------------------------------------------------------------------------------------------
Duration (minutes)............................ 120 60 90 30 30 30 30 60
Piles per day................................. 4 6 4 8 6 3 10 8
---------------------------------------------------------------------------------------------------------
Propagation (xLogR)........................... 15
---------------------------------------------------------------------------------------------------------
Distance of source level (m).................. 10
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 10--Calculated Level A Harassment Zones, Vibratory Installation and Removal (m)
----------------------------------------------------------------------------------------------------------------
Level A threshold
--------------------------------------------------------
Pile type High-frequency
cetaceans 173 dB Phocid pinnipeds Otariid pinnipeds
SELcum 201 dB SELcum 219 dB SELcum
----------------------------------------------------------------------------------------------------------------
36-inch steel piles (installation)..................... 161 67 5
24-to-30-inch steel pipe piles (installation).......... 25 10 1
24-inch steel piles, permanent (installation).......... 12 5 1
24-inch steel piles, temporary (installation and 9 4 1
removal)..............................................
18-inch steel pipe piles (installation)................ 13 6 1
12-inch steel H-piles (installation and removal)....... 3 1 1
18-inch creosote timber piles (removal)................ 35 15 1
[[Page 24447]]
16.5-inch concrete octagonal sections (removal)........ 55 23 2
----------------------------------------------------------------------------------------------------------------
Table 11--Level B Harassment Zones, Vibratory and Impact Driving (m)
------------------------------------------------------------------------
Level B threshold
Pile type all marine
mammals 120 dBrms
------------------------------------------------------------------------
120 dB threshold
------------------------------------------------------------------------
36-inch steel piles (installation)................... 21,545
24-to-30-inch steel pipe piles (installation)........ 3,981
24-inch steel piles (installation and removal)....... 1,847
18-inch steel pipe piles (installation).............. 3,415
12-inch steel H-piles (installation and removal)..... 1,000
18-inch creosote timber piles (removal).............. 6,310
16.5-inch concrete octagonal sections (removal)...... 7,365
------------------------------------------------------------------------
160 dB threshold
------------------------------------------------------------------------
36-inch steel piles (Installation)................... 736
24-inch steel piles, permanent (Installation)........ 465
------------------------------------------------------------------------
Marine Mammal Occurrence and Take Estimation
In this section we provide information about the occurrence of
marine mammals, including density or other relevant information which
will inform the take calculations. The primary source for density
estimates is from the Navy Marine Species Density Database (NMSDD)
Phase III for the Northwest Training and Testing Study Area (Navy,
2019) although density calculated from other aerial surveys was used
for harbor seal. These density estimates will be used to calculate take
due to the lack of site-specific data that is available.
To quantitatively assess potential exposure of marine mammals to
noise levels from pile driving over the NMFS threshold guidance, the
following equation was first used to provide an estimate of potential
exposures within estimated harassment zones:
Exposure estimate = N x Level B harassment zone (km\2\) x maximum days
of pile driving
where
N = density estimate (animals per km\2\) used for each species.
Harbor Seal
There are no harbor seal density estimates for Grays Harbor, but
the Navy Marine Species Density Database (NMSDD 2020) estimates the
density of harbor seals in the waters offshore of Grays Harbor as
0.3424 animals per square kilometer. However, harbor seals are
anticipated to be more common within Grays Harbor than within offshore
areas. Therefore, this density estimate may underestimate actual
densities for the project site.
Two aerial surveys of Grays Harbor were conducted in June of 2014.
The average count was multiplied by a regional correction factor of
1.43 (Huber et al., 2001) to yield the estimated harbor seal abundance.
A correction factor was used because aerial surveys of harbor seals on
land only produce a minimum assessment of the population and animals in
the water must be accounted for to estimate total abundance. The
average survey count (7,495 seals/survey) was used to calculate density
by dividing by the area of Grays Harbor (243 km\2\) resulting in a
calculated density of 30.85 animals per km\2\). This value was used to
calculate estimated take by both Level A harassment and Level B
harassment during the driving of the various types of piles for the
Project. Estimated takes by Level B harassment are shown in table 12
and takes by Level A harassment are shown in table 13.
The largest Level A harassment zone for phocid pinnipeds extends
from 157 to 445 m from the source during impact driving. AGP and NMFS
agreed on the implementation of a 100 m shutdown zone in order to shut
down for those animals closest to the pile driving activity but allow
for pile driving to continue for animals that are beyond 100 m (see
Proposed Mitigation section). AGP is confident they can complete work
in an efficient manner with the occurrence of harbor seals in the
project area. AGP has requested authorization of 18,830 takes of harbor
seals by Level B harassment as well as 73 harbor seal takes by Level A
harassment. NMFS concurs with the requests and is proposing to
authorize take of harbor seals at these levels.
Table 12--Calculated Take Estimate of Harbor Seals by Level B Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor seal Days of Level B Shutdown Shutdown Level B
Pile type Installation/removal method density per pile area zone area take
km\2\ driving (km\2\) distance (km\2\) estimate
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-inch steel piles (installation)......... Vibratory.................... 30.85 24 10.2 70 0.03 7,529.87
36-inch steel piles (installation)......... Impact to proof.............. 30.85 6 1.07 100 0.05 188.80
24-to-30-inch steel pipe piles Vibratory.................... 30.8 18 4.95 10 0.009 2,739.29
(installation).
[[Page 24448]]
24-inch steel piles, permanent Vibratory.................... 30.85 10 2.72 10 0.004 804.37
(installation).
24-inch steel piles, permanent Impact to proof.............. 30.85 2 0.46 100 0.05 30.36
(installation).
24-inch steel piles, temporary Vibratory.................... 30.85 12 2.72 10 0.004 1,005.46
(installation and removal).
18-inch steel pipe piles (installation).... Vibratory.................... 30.85 6 4.3 10 0.009 794.26
12-inch steel H-piles (installation and Vibratory.................... 30.85 6 1.7 10 0.004 313.93
removal).
18-inch creosote timber piles (removal).... Vibratory.................... 30.85 12 7.4 15 0.014 2,734.30
16.5-inch concrete octagonal sections Vibratory.................... 30.85 9 7.97 25 0.011 2,209.82
(removal).
------------------------------------------------------------------------------------------------------------
Total.................................. ............................. ........... ........... ........... ........... ........... 18,350
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 13--Calculated Take Estimate of Harbor Seals by Level A Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor seal Days of Level A Shutdown Shutdown Level A
Pile type installation/removal method density per pile area zone area take
km\2\ driving (km\2\) distance (km\2\) estimate
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-inch steel piles (installation)......... Vibratory.................... 30.85 24 0.03 70 0.03 0.00
36-inch steel piles (installation)......... Impact to proof.............. 30.85 6 0.43 100 0.05 70.34
24-to-30-inch steel pipe piles Vibratory.................... 30.8 18 0.009 10 0.009 0.00
(installation).
24-inch steel piles, permanent Vibratory.................... 30.85 10 0.002 10 0.004 0.00
(installation).
24-inch steel piles, permanent Impact to proof.............. 30.85 2 0.084 100 0.05 2.52
(installation).
24-inch steel piles, temporary Vibratory.................... 30.85 12 0.0018 10 0.004 0.00
(installation and removal).
18-inch steel pipe piles (installation).... Vibratory.................... 30.85 6 0.005 10 0.009 0.00
12-inch steel H-piles (installation and Vibratory.................... 30.85 6 0.0009 10 0.004 0.00
removal).
18-inch creosote timber piles (removal).... Vibratory.................... 30.85 12 0.014 15 0.014 0.00
16.5-inch concrete octagonal sections Vibratory.................... 30.85 9 0.01 25 0.011 0.00
(removal).
------------------------------------------------------------------------------------------------------------
Total.................................. ............................. ........... ........... ........... ........... ........... 73
--------------------------------------------------------------------------------------------------------------------------------------------------------
California Sea Lion
The NMSDD estimates the density of California sea lions in the
waters offshore of Grays Harbor as 0.0288, 0.5573 and 0.66493 animals
per km\2\ in summer, fall and winter, respectively (Navy, 2019). AGP
conservatively utilized the higher winter density value to calculate
estimated take. Based on this density estimate, the number of
California sea lions that may be taken by Level B harassment is
presented in table 14. Take by Level A harassment is not anticipated
since the nearest documented California sea lion haulout sites are at
the Westport Docks, approximately 13 miles west of the Project site
near the entrance to Grays Harbor (Jeffries et al., 2015), and another
haulout observed in 1997 referred to as the mid-harbor flats located
approximately 5.65 miles west of the Project site (WDFW, 2022).
Additionally, the largest Level A harassment zone is 33 m, with all the
other zones for both impact and vibratory driving no more than 12 m.
AGP has requested and NMFS is proposing to authorize 387 California
sea lion takes by Level B harassment as shown in table 14.
Table 14--Level B Harassment Take Estimates for California Sea Lions
--------------------------------------------------------------------------------------------------------------------------------------------------------
California
sea lion Days of Level B Shutdown Shutdown Level B
Pile type Installation/removal method density per pile area zone area take
km\2\ driving (km\2\) distance (km\2\) estimate
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-inch steel piles (installation)......... Vibratory.................... 0.6493 24 10.2 10 0.03 158.48
36-inch steel piles (installation)......... Impact to proof.............. 0.6493 6 1.07 35 0.016 4.11
24-to-30-inch steel pipe piles Vibratory.................... 0.6493 18 4.95 10 0.009 57.75
(installation).
24-inch steel piles, permanent Vibratory.................... 0.6493 10 2.72 10 0.004 16.93
(installation).
24-inch steel piles, permanent Impact to proof.............. 0.6493 2 0.46 15 0.006 0.71
(installation).
24-inch steel piles, temporary Vibratory.................... 0.6493 12 2.72 10 0.004 21.16
(installation and removal).
18-inch steel pipe piles (installation).... Vibratory.................... 0.6493 6 4.3 10 0.009 16.72
12-inch steel H-piles (installation and Vibratory.................... 0.6493 6 1.7 10 0.004 6.61
removal).
18-inch creosote timber piles (removal).... Vibratory.................... 0.6493 12 7.4 10 0.009 57.59
16.5-inch concrete octagonal sections Vibratory.................... 0.6493 9 7.97 10 0.004 46.55
(removal).
------------------------------------------------------------------------------------------------------------
Total.................................. ............................. ........... ........... ........... ........... ........... 387
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steller Sea Lion
The NMSDD estimates the density of Steller sea lions in the waters
offshore of Grays Harbor as 0.1993 animals per km\2\ in the summer,
0.1678 animals per km\2\ in the winter/spring, and 0.1390 animals per
km\2\ in the fall (Navy, 2020). The summer density estimate of 0.1993
per km\2\ has been used as a conservative surrogate for Steller sea
lion density within Grays Harbor.
WDFW Priority Habitat and Species Data does not indicate any
observances of Steller sea lions in Grays Harbor (WDFW, 2022). The
nearest documented Steller sea lion haulout sites to the Project site
are at Split Rock, 35 miles
[[Page 24449]]
north of the entrance to Grays Harbor, and at the mouth of the Columbia
River, 46 miles south of the entrance to Grays Harbor (Jeffries et al.,
2000). A few Steller sea lions may haul out on buoys near the Westport
marina, located 13 miles west of the Project site, or at Westport
docks, similar to California sea lions. Given that the Level A
harassment zone varies from one (1) to five (5) meters during vibratory
pile installation and 12 to 33 meters during impact installation, in
addition to their uncommon appearances in Grays Harbor, no take by
Level A harassment is anticipated or proposed by NMFS.
AGP has requested and NMFS is proposing to authorize 119 Steller
sea lion takes by Level B harassment as shown in table 15.
Table 15--Level B Harassment Take Estimates for Steller Sea Lions
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stellar sea
lion Days of Level B Shutdown Shutdown Level B
Pile type Installation/removal method density per pile area zone area take
km\2\ driving (km\2\) distance (km\2\) estimate
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-inch steel piles (installation)......... Vibratory.................... 0.1993 24 10.2 10 0.03 48.65
36-inch steel piles (installation)......... Impact to proof.............. 0.1993 6 1.07 35 0.016 1.26
24-to-30-inch steel pipe piles Vibratory.................... 0.1993 18 4.95 10 0.009 17.73
(installation).
24-inch steel piles, permanent Vibratory.................... 0.1993 10 2.72 10 0.004 5.20
(installation).
24-inch steel piles, permanent Impact to proof.............. 0.1993 2 0.46 15 0.006 0.22
(installation).
24-inch steel piles, temporary Vibratory.................... 0.1993 12 2.72 10 0.004 6.50
(installation and removal).
18-inch steel pipe piles (installation).... Vibratory.................... 0.1993 6 4.3 10 0.009 5.13
12-inch steel H-piles (installation and Vibratory.................... 0.1993 6 1.7 10 0.004 2.03
removal).
18-inch creosote timber piles (removal).... Vibratory.................... 0.1993 12 7.4 10 0.009 17.68
16.5-inch concrete octagonal sections Vibratory.................... 0.1993 9 7.97 10 0.004 14.29
(removal).
------------------------------------------------------------------------------------------------------------
Total.................................. ............................. ........... ........... ........... ........... ........... 119
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor Porpoise
The Navy has estimated that density of harbor porpoises in the
waters offshore of Grays Harbor is 0.467 animals per km\2\ (Navy,
2019). AGP acknowledges that this value may be an overestimate since it
is based on offshore observations. However, lacking additional survey
or anecdotal evidence, this NMSDD value is used as a conservative
estimate for the number of harbor porpoises that are expected to be
within Grays Harbor. Estimated take by Level B harassment is shown in
table 16.
During impact pile driving, the Level A harassment isopleths range
from 349 to 990 m for high-frequency cetaceans and up to 161 m during
vibratory driving. AGP has proposed to implement a maximum of 100-m
shutdown zone. This leaves large areas where take of harbor porpoises
by Level A harassment could occur. It would be challenging for
protected species observers to effectively monitor out to the full
extent of these zones given the cryptic nature of harbor porpoises.
Therefore, take was estimated using porpoise density multiplied by the
area of the Level A harassment zone beyond 100 m (in cases where the
Level A harassment zone exceeded the shutdown zone) multiplied by the
number of driving days as shown in table 17.
AGP has requested and NMFS is proposing to authorize 277 harbor
porpoise takes by Level B harassment and 5 harbor porpoises by Level A
harassment.
Table 16--Calculated Take Estimate of Harbor Porpoise by Level B Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor
porpoise Days of Level B Shutdown Shutdown Level B
Pile type Installation/removal method density per pile area zone area take
km\2\ driving (km\2\) distance (km\2\) estimate
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-inch steel piles (installation)......... Vibratory.................... 0.467 24 10.2 100 0.05 113.76
36-inch steel piles (installation)......... Impact to proof.............. 0.467 6 1.07 100 0.05 2.86
24-to-30-inch steel pipe piles Vibratory.................... 0.467 18 4.95 25 0.023 41.42
(installation).
24-inch steel piles, permanent Vibratory.................... 0.467 10 2.72 10 0.004 12.18
(installation).
24-inch steel piles, permanent Impact to proof.............. 0.467 2 0.46 100 0.05 0.46
(installation).
24-inch steel piles, temporary Vibratory.................... 0.467 12 2.72 10 0.004 15.22
(installation and removal).
18-inch steel pipe piles (installation).... Vibratory.................... 0.467 6 4.3 15 0.014 12.01
12-inch steel H-piles (installation and Vibratory.................... 0.467 6 1.7 10 0.004 4.75
removal).
18-inch creosote timber piles (removal).... Vibratory.................... 0.467 12 7.4 35 0.034 41.28
16.5-inch concrete octagonal sections Vibratory.................... 0.467 9 7.97 55 0.025 33.39
(removal).
------------------------------------------------------------------------------------------------------------
Total.................................. ............................. ........... ........... ........... ........... ........... 277
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 17--Calculated Take Estimate of Harbor Porpoise by Level A Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor
porpoise Days of Level A Shutdown Shutdown Level A
Pile type Installation/removal method density per pile area zone area take
km\2\ driving (km\2\) distance (km\2\) estimate
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-inch steel piles (installation)......... Vibratory.................... 0.467 24 0.086 100 0.05 0.40
36-inch steel piles (installation)......... Impact to proof.............. 0.467 6 1.64 100 0.05 4.46
24-to-30-inch steel pipe piles Vibratory.................... 0.467 18 0.023 25 0.023 0.00
(installation).
24-inch steel piles, permanent Vibratory.................... 0.467 10 0.005 10 0.004 0.00
(installation).
24-inch steel piles, permanent Impact to proof.............. 0.467 2 0.28 100 0.05 0.26
(installation).
24-inch steel piles, temporary Vibratory.................... 0.467 12 0.004 10 0.004 0.00
(installation and removal).
[[Page 24450]]
18-inch steel pipe piles (installation).... Vibratory.................... 0.467 6 0.012 15 0.014 0.00
12-inch steel H-piles (installation and Vibratory.................... 0.467 6 0.001 10 0.004 0.00
removal).
18-inch creosote timber piles (removal).... Vibratory.................... 0.467 12 0.034 35 0.034 0.00
16.5-inch concrete octagonal sections Vibratory.................... 0.467 9 0.025 55 0.025 0.00
(removal).
------------------------------------------------------------------------------------------------------------
Total.................................. ............................. ........... ........... ........... ........... ........... 5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 18--Estimated Take by Level A and Level B Harassment, by Species and Stock
----------------------------------------------------------------------------------------------------------------
Proposed
Stock Total take as
Common name Stock abundance Level A Level B proposed percentage
take of stock
----------------------------------------------------------------------------------------------------------------
Harbor porpoise................ Northern Oregon/ 22,074 5 277 282 1.3
Washington Coast.
Steller sea lion............... Eastern U.S....... 36,308 ......... 119 119 0.3
California sea lion............ U.S............... 257,606 ......... 387 387 0.2
Harbor seal.................... OR/WA coast stock. \a\ 24,731 73 18,350 18,423 74.5
----------------------------------------------------------------------------------------------------------------
\a\ There is no current estimate of abundance available for this stock. Value presented is the most recent
available and based on 1999 data.
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, NMFS
considers 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 and impact on
operations.
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 would observe the shutdown and
monitoring zones for a period of 30 minutes. The shutdown zone would 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. If the
monitoring zone has been observed for 30 minutes and marine mammals are
not present within the zone, soft-start procedures can commence and
work can continue. Pre-start clearance monitoring must be conducted
during periods of visibility sufficient for the lead PSO to determine
that the shutdown zones indicated in Table 19 are clear of marine
mammals. Pile driving may commence following 30 minutes of observation
when the determination is made that the shutdown zones are clear of
marine mammals. If work ceases for more than 30 minutes, the pre-
activity monitoring of both the monitoring zone and shutdown zone would
commence.
Implementation of Shutdown Zones for Level A Harassment--For all
pile driving/removal activities, AGP would implement shutdowns within
designated zones. The purpose of a shutdown zone is generally to define
an area within which shutdown of activity would occur upon sighting of
a marine mammal (or in anticipation of an animal entering the defined
area). Implementation of shutdowns would be used to avoid or minimize
takes by Level A harassment from vibratory and impact pile driving for
all four species for which take may occur. Shutdown zones would be
based upon the Level A harassment isopleth for each pile size/type and
driving method where applicable. However, a maximum shutdown zone of
100 m was requested by AGP and is being proposed by NMFS. This is
anticipated to reduce Level A harassment exposures without resulting in
a substantial risk to the project schedule that could occur if marine
mammals repeatedly enter into larger shutdown zones.
A minimum shutdown zone of 10 m would be required for all in-water
construction activities to avoid physical interaction with marine
mammals. Proposed shutdown zones for each activity type are shown in
table 19.
[[Page 24451]]
Table 19--Shutdown Zones During Pile Installation and Removal (m)
----------------------------------------------------------------------------------------------------------------
Shutdown zone
------------------------------------------------ Level B
Pile type High- harassment
frequency Phocid Otariid zone
cetaceans pinnipeds pinnipeds
----------------------------------------------------------------------------------------------------------------
Impact
----------------------------------------------------------------------------------------------------------------
36-inch steel piles (installation).............. 100 100 35 740
24-inch steel piles, permanent (installation)... 100 100 15 465
----------------------------------------------------------------------------------------------------------------
Vibratory
----------------------------------------------------------------------------------------------------------------
36-inch steel piles (installation).............. 100 70 10 21,550
24-to-30-inch steel pipe piles (installation)... 25 10 10 3,985
24-inch steel piles, permanent (installation)... 15 10 10 1,850
24-inch steel piles, temporary (installation and 10 10 10 1,850
removal).......................................
18-inch steel pipe piles (installation)......... 15 10 10 3,415
12-inch steel H-piles (installation and removal) 10 10 10 1,000
18-inch creosote timber piles (removal)......... 35 15 10 6,310
16.5-inch concrete octagonal sections (removal). 55 25 10 7,365
----------------------------------------------------------------------------------------------------------------
All marine mammals would be monitored in the Level B harassment
zones and throughout the area as far as visual monitoring can take
place. If a marine mammal enters the Level B harassment zone, in-water
activities would continue and protected Species Observers (PSOs) would
document the animal's presence within the estimated harassment zone.
If a species for which authorization has not been granted, or a
species which has been granted but the authorized takes are met, is
observed approaching or within the Level B harassment zone, pile
driving activities will be shut down immediately. Activities will not
resume until the animal has been confirmed to have left the area or 15
minutes has elapsed with no sighting of the animal.
Soft Start--The use of soft-start procedures are believed to
provide additional protection to marine mammals by providing warning
and/or giving marine mammals a chance to leave the area prior to the
hammer operating at full capacity. For impact pile driving, contractors
would be required to provide an initial set of strikes from the hammer
at reduced energy, with each strike followed by a 30-second waiting
period. This procedure would be conducted a total of three times before
impact pile driving begins. Soft start would be implemented at the
start of each day's impact pile driving and at any time following
cessation of impact pile driving for a period of 30 minutes or longer.
Soft start is not required during vibratory pile driving and removal
activities.
Bubble Curtain--A bubble curtain would be employed during impact
installation or proofing of steel piles. A noise attenuation device
would not be required during vibratory pile driving. If a bubble
curtain or similar measure is used, it would distribute air bubbles
around 100 percent of the piling perimeter for the full depth of the
water column. Any other attenuation measure would be required to
provide 100 percent coverage in the water column for the full depth of
the pile. The lowest bubble ring would be in contact with the mudline
for the full circumference of the ring. The weights attached to the
bottom ring would ensure 100 percent mudline contact. No parts of the
ring or other objects would prevent full mudline contact. Air flow to
the bubblers must be balanced around the circumference of the pile.
Based on our evaluation of the applicant's proposed measures, NMFS
has preliminarily determined that the proposed mitigation measures
provide the means of effecting the least practicable impact on the
affected species or stocks and their habitat, paying particular
attention to rookeries, mating grounds, and areas of similar
significance.
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 while
conducting the activities. 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:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
<bullet> 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 activity; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
<bullet> How anticipated responses to stressors impact either: (1)
long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
<bullet> Mitigation and monitoring effectiveness.
Visual Monitoring
Monitoring shall be conducted by NMFS-approved observers in
[[Page 24452]]
accordance with sections 13.1 and 13.2 of the application. Trained
observers shall be placed from the best vantage point(s) practicable to
monitor for marine mammals and implement shutdown or delay procedures
when applicable through communication with the equipment operator.
Observer training must be provided prior to project start, and shall
include instruction on species identification (sufficient to
distinguish the species in the project area), description and
categorization of observed behaviors and interpretation of behaviors
that may be construed as being reactions to the specified activity,
proper completion of data forms, and other basic components of
biological monitoring, including tracking of observed animals or groups
of animals such that repeat sound exposures may be attributed to
individuals (to the extent possible).
Monitoring would be conducted 30 minutes before, during, and 30
minutes after pile driving/removal activities. In addition, observers
shall record all incidents of marine mammal occurrence, regardless of
distance from activity, and shall document any behavioral reactions in
concert with distance from piles being driven or removed. Pile driving/
removal activities include the time to install or remove a single pile
or series of piles, as long as the time elapsed between uses of the
pile driving equipment is no more than 30 minutes.
A minimum of three PSOs would be on duty during all in-water pile
driving activities. One observer will be stationed on the existing dock
or similar location to monitor the Level A harassment zones, and two
other observers will be stationed throughout the Level B harassment
zones where best line of sight views would provide most complete
coverage of the zone. PSOs would monitor for marine mammals entering
the harassment zones; the position(s) may vary based on construction
activity and location of piles or equipment.
PSOs would scan the waters using binoculars and would use a
handheld range-finder device to verify the distance to each sighting
from the project site. All PSOs would be trained in marine mammal
identification and behaviors and are required to have no other project-
related tasks while conducting monitoring. In addition, monitoring
would be conducted by qualified observers, who would be placed at the
best vantage point(s) practicable to monitor for marine mammals and
implement shutdown/delay procedures when applicable by calling for the
shutdown to the hammer operator via a radio. AGP would adhere to the
following observer qualifications:
(i) PSOs must be independent of the activity contractor (for
example, employed by a subcontractor) and have no other assigned tasks
during monitoring periods.
(ii) At least one PSO must have prior experience performing the
duties of a PSO during construction activity pursuant to a NMFS-issued
incidental take authorization.
(iii) Other PSOs may substitute other relevant experience,
education (degree in biological science or related field), or training
for prior experience performing the duties of a PSO during construction
activity pursuant to a NMFS-issued incidental take authorization.
(iv) Where a team of three or more PSOs is required, a lead
observer or monitoring coordinator must be designated. The lead
observer must have prior experience performing the duties of a PSO
during construction activity pursuant to a NMFS-issued incidental take
authorization.
(v) PSOs must be approved by NMFS prior to beginning any activity
subject to this IHA.
Additional standard observer qualifications include:
<bullet> Ability to conduct field observations and collect data
according to assigned protocols;
<bullet> Experience or training in the field identification of
marine mammals, including the identification of behaviors;
<bullet> Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
<bullet> Writing skills sufficient to prepare a report of
observations including but not limited to the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates and times when in-water construction
activities were suspended to avoid potential incidental injury from
construction sound of marine mammals observed within a defined shutdown
zone; and marine mammal behavior; and
<bullet> 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.
Reporting
A draft marine mammal monitoring report would be submitted to NMFS
within 90 days after the completion of pile driving and removal
activities. It would include an overall description of work completed,
a narrative regarding marine mammal sightings, and associated PSO data
sheets. Specifically, the report must include:
<bullet> Dates and times (begin and end) of all marine mammal
monitoring.
<bullet> Construction activities occurring during each daily
observation period, including the number and type of piles driven or
removed and by what method (i.e., impact driving) and the total
equipment duration for cutting for each pile or total number of strikes
for each pile (impact driving).
<bullet> PSO locations during marine mammal monitoring.
<bullet> Environmental conditions during monitoring periods (at
beginning and end of PSO shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance.
<bullet> Upon observation of a marine mammal, the following
information: Name of PSO who sighted the animal(s) and PSO location and
activity at time of sighting; Time of sighting; Identification of the
animal(s) (e.g., genus/species, lowest possible taxonomic level, or
unidentified), PSO confidence in identification, and the composition of
the group if there is a mix of species; Distance and bearing of each
marine mammal observed relative to the pile being driven for each
sighting (if pile driving was occurring at time of sighting); Estimated
number of animals (min/max/best estimate); Estimated number of animals
by cohort (adults, juveniles, neonates, group composition, etc.);
Animal's closest point of approach and estimated time spent within the
harassment zone; and Description of any marine mammal behavioral
observations (e.g., observed behaviors such as feeding or traveling),
including an assessment of behavioral responses thought to have
resulted from the activity (e.g., no response or changes in behavioral
state such as ceasing feeding, changing direction, flushing, or
breaching).
<bullet> Number of marine mammals detected within the harassment
zones, by species.
<bullet> Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensued, and resulting changes in behavior of the
animal(s), if any.
If no comments are received from NMFS within 30 days, the draft
final report would constitute the final report. If comments are
received, a final report addressing NMFS comments must be submitted
within 30 days after receipt of comments.
[[Page 24453]]
Reporting Injured or Dead Marine Mammals
In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner prohibited by the IHA
(if issued), such as an injury, serious injury or mortality, AGP would
immediately cease the specified activities and report the incident to
the Office of Protected Resources, NMFS, and the West Coast Region
regional stranding coordinator. The report would include the following
information:
<bullet> Description of the incident;
<bullet> Environmental conditions (e.g., Beaufort sea state,
visibility);
<bullet> Description of all marine mammal observations in the 24
hours preceding the incident;
<bullet> Species identification or description of the animal(s)
involved;
<bullet> Fate of the animal(s); and
<bullet> Photographs or video footage of the animal(s) (if
equipment is available).
Activities would not resume until NMFS is able to review the
circumstances of the prohibited take. NMFS would work with AGP to
determine what is necessary to minimize the likelihood of further
prohibited take and ensure MMPA compliance. AGP would not be able to
resume their activities until notified by NMFS.
In the event that the AGP discovers an injured or dead marine
mammal, and the lead PSO determines that the cause of the injury or
death is unknown and the death is relatively recent (e.g., in less than
a moderate state of decomposition as described in the next paragraph),
AGP would immediately report the incident to the Office of Protected
Resources (<a href="/cdn-cgi/l/email-protection#dd8d8ff394898df390b2b3b4a9b2afb4b3ba8fb8adb2afa9ae9db3b2bcbcf3bab2ab"><span class="__cf_email__" data-cfemail="da8a88f4938e8af497b5b4b3aeb5a8b3b4bd88bfaab5a8aea99ab4b5bbbbf4bdb5ac">[email protected]</span></a>), NMFS and to the West
Coast Region regional stranding coordinator as soon as feasible. The
report would include the same information identified in the paragraph
above. Activities would be able to continue while NMFS reviews the
circumstances of the incident. NMFS would work with AGP to determine
whether modifications in the activities are appropriate.
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 impacts or responses (e.g., intensity, duration),
the context of any impacts or responses (e.g., critical reproductive
time or location, foraging impacts affecting energetics), as well as
effects on habitat, and the likely effectiveness of the mitigation. We
also assess the number, intensity, and context of estimated takes by
evaluating this information relative to population status. Consistent
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338,
September 29, 1989), the impacts from other past and ongoing
anthropogenic activities are incorporated into this analysis via their
impacts on the 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 majority of our analysis applies to all
the species listed in table 18, given that many of the anticipated
effects of this project on different marine mammal stocks are expected
to be relatively similar in nature. Where there are meaningful
differences between species or stocks, or groups of species, in
anticipated individual responses to activities, impact of expected take
on the population due to differences in population status, or impacts
on habitat, they are described independently in the analysis below.
Pile driving and removal activities associated with the project as
outlined previously, have the potential to disturb or displace marine
mammals. Specifically, the specified activities may result in take, in
the form of Level A harassment and Level B harassment from underwater
sounds generated from pile driving and removal. Potential takes could
occur if individuals of these species are present in zones ensonified
above the thresholds for Level A or Level B harassment identified above
when these activities are underway.
Take by Level A and Level B harassment would be due to potential
behavioral disturbance, TTS, and PTS. No serious injury or mortality is
anticipated or proposed for authorization given the nature of the
activity and measures designed to minimize the possibility of injury to
marine mammals. Take by Level A harassment is only anticipated for
harbor porpoise and harbor seal. The potential for harassment is
minimized through the construction method and the implementation of the
planned mitigation measures (see Proposed Mitigation section).
Based on reports in the literature as well as monitoring from other
similar activities, behavioral disturbance (i.e., Level B harassment)
would likely be limited to reactions such as increased swimming speeds,
increased surfacing time, or decreased foraging (if such activity were
occurring) (e.g., Thorson and Reyff, 2006; HDR, Inc., 2012; Lerma,
2014). Most likely for pile driving, individuals would simply move away
from the sound source and be temporarily displaced from the areas of
pile driving, although even this reaction has been observed primarily
only in association with impact pile driving. The pile driving
activities analyzed here are similar to, or less impactful than,
numerous other construction activities conducted in Washington, which
have taken place with no observed severe responses of any individuals
or known long-term adverse consequences. Level B harassment would be
reduced to the level of least practicable adverse impact through use of
mitigation measures described herein and, if sound produced by project
activities is sufficiently disturbing, animals are likely to simply
avoid the area while the activity is occurring. While vibratory driving
associated with the proposed project may produce sound at distances of
many kilometers from the project site, thus overlapping with some
likely less-disturbed habitat, the project site itself is located in a
busy harbor and the majority of sound fields produced by the specified
activities are close to the harbor. Animals disturbed by project sound
would be expected to avoid the area and use nearby higher-quality
habitats.
In addition to the expected effects resulting from authorized Level
B harassment, we anticipate that harbor porpoises and harbor seals may
sustain some limited Level A harassment in the form of auditory injury.
However, animals in these locations that experience PTS would likely
only receive slight PTS, i.e., minor degradation of hearing
capabilities within regions of hearing that align most completely with
the energy produced by pile driving, i.e., the low-frequency region
below 2 kHz, not severe hearing impairment or impairment in the regions
of greatest hearing sensitivity. If hearing impairment occurs, it is
most likely that the affected animal would
[[Page 24454]]
lose a few decibels in its hearing sensitivity, which in most cases is
not likely to meaningfully affect its ability to forage and communicate
with conspecifics. As described above, we expect that marine mammals
would be likely to move away from a sound source that represents an
aversive stimulus, especially at levels that would be expected to
result in PTS, given sufficient notice through use of soft start.
The project also is not expected to have significant adverse
effects on affected marine mammals' habitat. The project activities
would not modify existing marine mammal habitat for a significant
amount of time. The activities may cause some fish or invertebrates to
leave the area of disturbance, thus temporarily impacting marine
mammals' foraging opportunities in a limited portion of the foraging
range; but, because of the short duration of the activities, the
relatively small area of the habitat that may be affected, and the
availability of nearby habitat of similar or higher value, the impacts
to marine mammal habitat are not expected to cause significant or long-
term negative consequences. While there are haulouts for pinnipeds in
the area, these locations are some distance from the actual project
site. According to WDFW's atlas of seal and sea lion haulout sites
(Jeffries et al., 2000), all haulouts in Grays Harbor are associated
with tidal flats and at high tide it is assumed that these animals are
foraging elsewhere in the estuary. The nearest documented harbor seal
haulout site to the Project site is a low-tide haulout located 6 miles
to the west of the project site. The nearest documented California sea
lion haulout sites to the Project site are at the Westport Docks,
approximately 13 miles west of the Project site near the entrance to
Grays Harbor (Jeffries et al., 2015), and another haulout observed in
1997 referred to as the mid-harbor flats located approximately 5.65
miles west of the Project site (WDFW, 2022). The nearest documented
Steller sea lion haulout sites to the Project site are at Split Rock,
35 miles north of the entrance to Grays Harbor, and at the mouth of the
Columbia River, 46 miles south of the entrance to Grays Harbor
(Jeffries et al., 2000). A few Steller sea lions may haul out on buoys
near the Westport marina, located 13 miles west of the Project site, or
at Westport docks, similar to California sea lions. While repeated
exposures of individuals to this pile driving activity could cause
limited Level A harassment in harbor seals and Level B harassment in
seals and sea lions, they are unlikely to considerably disrupt foraging
behavior or result in significant decrease in fitness, reproduction, or
survival for the affected individuals.
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 any of the species
or stocks through effects on annual rates of recruitment or survival:
<bullet> No serious injury or mortality is anticipated or
authorized;
<bullet> Any Level A harassment exposures (i.e., to harbor porpoise
and harbor seals, only) are anticipated to result in slight PTS (i.e.,
of a few decibels), within the lower frequencies associated with pile
driving;
<bullet> The anticipated incidents of Level B harassment would
consist of, at worst, temporary modifications in behavior that would
not result in fitness impacts to individuals;
<bullet> The ensonifed areas from the project is very small
relative to the overall habitat ranges of all species and stocks;
<bullet> Repeated exposures of pinnipeds to this pile driving
activity could cause slight Level A harassment in seals and Level B
harassment in seals and sea lion species, but are unlikely to
considerably disrupt foraging behavior or result in significant
decrease in fitness, reproduction, or survival for the affected
individuals. In all, there would be no adverse impacts to the stocks as
a whole; and
<bullet> The proposed mitigation measures are expected to reduce
the effects of the specified activity to the level of least practicable
adverse impact.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS preliminarily finds that the total marine
mammal take from the proposed activity will have a negligible impact on
all affected marine mammal species or stocks.
Small Numbers
As noted previously, only take of small numbers of marine mammals
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is fewer than one-third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
Table 18 demonstrates the number of instances in which individuals
of a given species could be exposed to received noise levels that could
cause take of marine mammals. Our analysis shows that less than 2
percent of all but one stock could be taken by harassment. While the
percentage of stock taken from the Oregon/Washington coastal stock of
harbor seal appears to be high (74.5 percent), in reality the number of
individuals taken by harassment would be far less. Instead, it is more
likely that there will be multiple takes of a smaller number of
individuals over multiple days, lowering the number of individuals
taken. The range of the Oregon/Washington coastal stock includes harbor
seals from the California/Oregon border to Cape Flattery on the Olympic
Peninsula of Washington, which is a distance of approximately 150 miles
(240 km) (Carretta et al., 2002). Additionally, there are over 150
Oregon/Washington coastal harbor seal stock haulouts along the outer
Washington coast spanning from the Columbia River north to Tatoosh
Island on the northwestern tip of the Olympic Peninsula (Scordino,
2010). This figure does not include many additional haulout sites found
along the Oregon coast. Given the expansive range of the Oregon/
Washington coastal stock along with the numerous haulouts that have
been documented on the Washington coast, it is unlikely that the number
of individuals taken, limited largely to the pool of seals present in
Grays Harbor, would exceed \1/3\ of the stock. In consideration of
various factors described above, we have preliminarily determined that
numbers of individuals taken would comprise less than one-third of the
best available population abundance estimate of the Oregon/Washington
coastal stock of harbor seal.
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 would be taken relative to the population
size of the affected species or stocks.
[[Page 24455]]
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 of 1973 (16 U.S.C. 1531 et seq.)
requires that each Federal agency insure that any action it authorizes,
funds, or carries out is not likely to jeopardize the continued
existence of any endangered or threatened species or result in the
destruction or adverse modification of designated critical habitat. To
ensure ESA compliance for the issuance of IHAs, NMFS consults
internally whenever we propose to authorize take for endangered or
threatened species.
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 AGP for conducting pile driving activities at the Port
from July 16, 2024 through July 15, 2025, provided the previously
mentioned mitigation, monitoring, and reporting requirements are
incorporated. A draft of the proposed IHA can be found at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</a>.
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 pile
driving by AGP. We also request 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, one-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:
<bullet> A request for renewal is received no later than 60 days
prior to the needed renewal IHA effective date (recognizing that the
renewal IHA expiration date cannot extend beyond one year from
expiration of the initial IHA).
<bullet> 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).
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.
<bullet> 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: April 1, 2024.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2024-07338 Filed 4-5-24; 8:45 am]
BILLING CODE 3510-22-P
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This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.