[Federal Register Volume 88, Number 208 (Monday, October 30, 2023)]
[Proposed Rules]
[Pages 74113-74141]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-23737]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 217
[Docket No. 231023-0251]
RIN 0648-BL79
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the Naval Magazine Indian Island
Ammunition Wharf Maintenance and Pile Replacement Project, Puget Sound,
Washington
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Proposed rule, request for comments.
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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for
authorization to take marine mammals incidental to the maintenance and
pile replacement construction activities at the Ammunition Wharf at
Naval Magazine (NAVMAG) Indian Island in Puget Sound, Washington, over
the course of 5 years (2024-2029). As required by the Marine Mammal
Protection Act (MMPA), NMFS is proposing regulations to govern that
take, and requests comments on the proposed regulations. 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 November
29, 2023.
ADDRESSES: You may submit comments on this document, identified by
NOAA-NMFS-2023-0122, by the following method:
Electronic submission: Submit all electronic public
comments via the Federal e-Rulemaking Portal. Go to https://www.regulations.gov and enter NOAA-NMFS-2023-0122 in the Search box,
click the ``Comment'' icon, complete the required fields, and enter or
attach your comments.
Instructions: Comments sent by any other method, to any other
address or individual, or received after the end of the comment period,
may not be considered by NMFS. All comments received are a part of the
public record and will generally be posted for public viewing on
https://www.regulations.gov without change. All personal identifying
information (e.g., name, address), confidential business information,
or otherwise sensitive information submitted voluntarily by the sender
will be publicly accessible. NMFS will accept anonymous comments (enter
``N/A'' in the required fields if you wish to remain anonymous).
Attachments to electronic comments will be accepted in Microsoft Word,
Excel, or Adobe PDF file formats only.
FOR FURTHER INFORMATION CONTACT: Robert Pauline, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Availability of Navy's Application, Marine Mammal Monitoring Plan, and
List of References
A copy of the Navy's application, monitoring plan, and any
supporting documents, as well as a list of the references cited in this
document, may be obtained online at: https://
[[Page 74114]]
www.fisheries.noaa.gov/action/incidental-take-authorization-taking-
marine-mammals-incidental-naval-magazine-indian-island. In case of
problems accessing these documents, please call the contact listed
above (see FOR FURTHER INFORMATION CONTACT).
Purpose and Need for Regulatory Action
This proposed rule, if adopted, would establish a framework under
the authority of the MMPA (16 U.S.C. 1361 et seq.) to authorize, for a
five-year period (2024-2029), take of marine mammals incidental to the
Navy's construction activities associated with maintenance and pile
replacement at the Ammunition Wharf at NAVMAG Indian Island.
We received an application from the Navy requesting 5-year
regulations and authorization to take multiple species of marine
mammals. Take would occur by Level A and Level B harassment incidental
to impact and vibratory pile driving. Please see Background below for
definitions of harassment.
Legal Authority for the Proposed Action
Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs
the Secretary of Commerce 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 for up to 5 years if,
after notice and public comment, the agency makes certain findings and
issues regulations that set forth permissible methods of taking
pursuant to that activity and other means of effecting the ``least
practicable adverse impact'' on the affected species or stocks and
their habitat (see the discussion below in the Proposed Mitigation
section), as well as monitoring and reporting requirements. Section
101(a)(5)(A) of the MMPA and the implementing regulations at 50 CFR
part 216, subpart R provide the legal basis for issuing this proposed
rule containing 5-year regulations, and for any subsequent letters of
authorization (LOAs). As directed by this legal authority, this
proposed rule contains mitigation, monitoring, and reporting
requirements.
Summary of Major Provisions Within the Proposed Rule
The following is a summary of the major provisions of this proposed
rule regarding Navy construction activities. These provisions include
measures requiring:
monitoring of the construction areas to detect the
presence of marine mammals before beginning construction activities;
Shutdown of construction activities under certain
circumstances to avoid injury of marine mammals;
Soft start for impact pile driving to allow marine mammals
the opportunity to leave the area prior to beginning impact pile
driving at full power; and
Use of bubble curtains to attenuate sound levels when
impact driving steel piles.
Background
Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1361 et seq.) directs
the Secretary of Commerce (as subsequently 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, regulations are
issued, and notice is provided to the public.
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), and if the permissible methods of taking and
requirements pertaining to the mitigation, monitoring and reporting of
the takings are set forth.
NMFS has defined ``negligible impact'' in 50 CFR 216.103 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.
Except with respect to certain activities not pertinent here, 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).
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 promulgation of
regulations and subsequent issuance of an incidental take authorization
with respect to potential impacts on the human environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 of the Companion Manual for NOAA
Administrative Order 216-6A, which do not individually or cumulatively
have the potential for significant impacts on the quality of the human
environment and for which we have not identified any extraordinary
circumstances that would preclude this categorical exclusion.
Accordingly, NMFS has preliminarily determined that the issuance of the
proposed rule qualifies to be categorically excluded from further NEPA
review.
Information in the Navy's application and this document
collectively provide the environmental information related to proposed
issuance of these regulations and subsequent incidental take
authorization for public review and comment. We will review all
comments submitted in response to this notice of proposed rulemaking
prior to concluding our NEPA process and prior to making a final
decision on the request for incidental take authorization.
Summary of Request
In May 2021, NMFS received a request from the Navy requesting
authorization to take small numbers of eight species of marine mammals
incidental to construction activities at the Ammunition Wharf at NAVMAG
Indian Island. The Navy has requested regulations that would establish
a process for authorizing such take via an LOA. NMFS reviewed the
Navy's application, and sent initial questions regarding the
application to the Navy on October 5, 2021. The Navy addressed the
questions and submitted a revised LOA application on March 24, 2022.
After additional questions were sent by NMFS, the Navy submitted
another revised application on May 13, 2022, and the revised
application was deemed adequate and complete on June 9, 2022. The
application was published for public review and comment on August 4,
2022 (87 FR 47722). Following publication of the application, the Navy
delayed the project start date by 1 year.
The Navy requests authorization to take eight species of marine
mammals by Level B harassment. They have also requested authorization
to take one of these species by Level A harassment. Neither the Navy
nor NMFS expects serious injury or mortality to result from this
activity. The proposed regulations would be valid for 5 years (2024-
2029).
[[Page 74115]]
Description of Proposed Activity
Overview
The Navy proposes to replace defective structural concrete and
fender piles as well as conduct maintenance and repair activities on
the Ammunition Wharf at NAVMAG Indian Island. Maintaining this wharf
structure is vital to sustaining the Navy's mission and ensuring
readiness. The Navy proposes to replace up to 118 structural concrete
piles or fender piles, conduct maintenance, and engage in repair
activities over a 7-year period on the Ammunition Wharf. However, the
proposed LOA would only be valid for 5 years. The Navy plans to conduct
necessary work, including impact and vibratory pile driving, to replace
and maintain the wharf structure. Under the proposed 5-year LOA, up to
110 structurally unsound structural piles or fender piles would be
replaced. Structural concrete piles would be replaced with 24-inch
concrete piles and old fender piles would be replaced with 14-inch
steel H piles or 18.75-inch composite piles. Up to eight steel piles
may also be installed in addition to the structural concrete piles if
necessary. The 2 years following the expiration of the LOA would
consist of removal and installation of concrete piles, and maintenance
and repair work. The Navy would request incidental take authorizations
as necessary for the final 2 years of work.
Dates and Duration
The proposed regulations would be valid for a period of 5 years
from October 1, 2024, until September 30, 2029. All pile driving would
be conducted during the prescribed in-water work window of October 1 to
January 15 to avoid conducting activities when juvenile salmonids are
most likely to be present. A conservative estimate of annual pile
driving days over the duration of the 5-year LOA based on the
assumption that pile driving rates would be relatively slow would be
approximately 24 days per year with up to 22 concrete piles or fender
piles, and up to 2 steel piles installed per year. Conservatively, one
concrete pile would be installed per day using jetting followed by
proofing with an impact hammer. There may be extra days for additional
proofing or weather/equipment delays. Actual daily production rates may
be higher (often two piles are installed in a day), resulting in fewer
actual pile driving days.
Specific Geographic Region
NAVMAG Indian Island is located near Port Hadlock in Jefferson
County, Washington, southeast of Port Townsend, at the northeast corner
of the Olympic Peninsula (Figure 1). The island is approximately 8
kilometers (km) long and 2 km wide, and comprises approximately 11 km
square (km\2\). NAVMAG Indian Island is located between Port Townsend
Bay and Kilisut Harbor. The Federal Government owns the island and
provides an easement on a small portion of the southern extent of the
island to Washington State Department of Transportation for access to
Marrowstone Island along State Route 116. NAVMAG Indian Island is the
West Coast ammunition ordnance storage center supporting the U.S. Navy
Pacific Fleet.
NAVMAG Indian Island occupies approximately 19 km of shoreline
within Port Townsend Bay. There are two marine structures located at
NAVMAG Indian Island, the Ammunition Wharf and the Small Craft Pier,
but only the Ammunition Wharf activities are addressed in this proposed
rule. Its primary mission is to load, offload, and provide storage and
logistics management for ordnance used on Navy vessels.
BILLING CODE 3510-22-P
[[Page 74116]]
[GRAPHIC] [TIFF OMITTED] TP30OC23.000
BILLING CODE 3510-22-C
Detailed Description of the Specified Activity
NAVMAG Indian Island is the West Coast ammunition ordnance storage
center supporting the U.S. Navy Pacific Fleet. Its primary mission is
to load, offload, and provide storage and logistics management for
ordnance used on Navy vessels. Construction of the Ammunition Wharf was
completed in 1979, and there are a total of 1,783 piles in the
Ammunition Wharf: 1,391 structural piles, 306 fender piles and 86
Operations Building piles.
The Ammunition Wharf was originally constructed using precast
concrete piles. As a result of the steam curing process used at that
time, an unknown quantity of piling is susceptible to a potentially
catastrophic condition called Delayed Ettringite Formation (DEF). DEF
is a result of high early temperatures in the concrete, which prevents
the normal formation of ettringite. DEF occurs rapidly and without
warning.
The Navy schedules inspections on waterfront facilities that
usually occur every 3 years, but due to DEF at the Ammunition Wharf,
inspections for that structure occur every two years. Based on the most
recent inspection in 2021, there are 161 piles (158 under Ammunition
Pier and three under the Operations Building at Ammunition Wharf) with
some appreciable level of DEF damage (most or all of those piles will
be replaced). More piles with DEF damage may be detected and therefore
may need to be replaced over the duration of the LOA.
Table 1 shows the details of the proposed construction activities
which are described below in greater detail.
[[Page 74117]]
Table 1--Project Components for Pile Replacement for the Ammunition
Wharf
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Wharf structure (in-water
construction) Construction details
------------------------------------------------------------------------
Total Piles....................... Up to 118 piles installed over 5
years (including up to eight steel
piles, with the remainder
concrete).
Quantity of concrete piles (24- Up to 22 per year over 5 years.
inch).
Quantity of permanent steel piles Up to 2 per year (Maximum of 8) over
(36-inch). 5 years (Currently no steel pile
installation is planned,
installation would depend on future
pile inspections).
Pile Removal Method............... Cutting.
Pile Installation Method.......... Jetting and impact driving of
concrete piles; Vibratory and
impact driving of steel piles. No
simultaneous pile driving will
occur.
Quantity of piles above -30 feet All.
MLLW.
Maximum number of piles driven per Two concrete piles per day. One
day (approximately). steel pile per day.
Total duration of impact pile No more than 45 minutes per day
driving. (mean = 10 minutes for concrete
piles; 15 minutes for steel piles).
Maximum duration of vibratory pile No more than 30 minutes (mean = 10
driving. minutes per steel pile).
Marine Construction Duration 3.5 months per year (In water work
(including in-water restrictions). window: October 1-January 15).
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Removal of Existing Piles
After demolition of the deck portions of the wharf located above
the waterline, three methods of pile removal (cutting/chipping,
clamshell removal, and direct pull) may be used. However, hydraulic
cutting will be the primary method of pile removal due to working under
the wharf and the DEF damage to the piles. In some cases, piles may be
cut at or below the mudline, with the below-mudline portion of the pile
left in place. None of these pile removal activities are anticipated to
result in take of marine mammals; therefore, they are not discussed
further beyond the brief elaboration on jetting and pile cutting
provided below.
Pile Installation
Three methods of pile installation for concrete and steel piles may
be used (vibratory, jetting, and impact) depending on the type of pile
and site conditions. Only one pile will be installed at a time; no
simultaneous pile driving will occur. These methods are described
below.
The primary methods of concrete pile installation would be water
jetting to within 3 meters (m) of final depth and then impact pile
driving to set or proof the final 3 m. Water jetting aids the
penetration of a pile into a dense sand or sandy gravel stratum. Water
jetting utilizes a carefully directed and pressurized flow of water at
the pile tip, which disturbs a ring of soils directly beneath it. The
jetting technique liquefies the soils at the pile tip during pile
placement, reducing the friction and interlocking between adjacent sub
grade soil particles around the water jet. For load-bearing structures,
an impact hammer is typically required to strike a pile a number of
times to ensure it has met the load-bearing specifications; this is
referred to as ``proofing.'' Load-bearing piles installed with water
jetting would still need to be proofed with an impact pile driver.
A vibratory hammer may be used to install the structural steel
piles and fender piles. The primary method of pile installation for
steel piles would be vibratory to within 3 m of final depth and then
impact pile driving to set or proof the final 3 m. The vibratory pile
driver method is a technique that may be used in pile installation
where the substrate allows. Use of this technique may be limited in
very hard substrates. This process begins by placing a choker cable
around a pile and lifting it into vertical position with a crane. The
pile is then lowered into position and set in place at the mudline. The
pile is held steady while the vibratory driver installs the pile to the
required tip elevation. In some substrates, a vibratory driver may be
unable to advance a pile until it reaches the required depth. In these
cases, an impact hammer may be used to advance the pile to the required
depth.
Impact hammers may be used to proof concrete piles that have been
jetted to depth or steel piles that have been driven using the
vibratory method. Proofing involves impact pile driving to determine if
the pile has been driven to the proper load-bearing specifications
within the substrate. Proofing of concrete piles at the Ammunition
Wharf in 2015 and 2016 required 200-600 strikes per pile to complete
(Navy, 2016).
Impact hammers have a heavy piston that moves up and down striking
the top of the pile and driving the pile into the substrate from the
downward force of the hammer. Impact hammer pile proofing can typically
take a minute or less to 30 minutes depending on pile type, pile size,
and conditions (i.e., bedrock, loose soils, etc.) to reach the required
tip elevation.
The Navy states that piles will be advanced to the extent
practicable with a vibratory driver and only impact driven when
required for proofing or when a pile cannot be advanced with a
vibratory driver due to hard substrate conditions.
Existing piles that are structurally sound may require additional
repair activities. Such activities could include wetwell repair;
recoating of piles and mooring fittings; installation or replacement of
passive cathode protection systems; repair and replacement of pile
caps; concrete repair; mooring foundation and substructure repair;
replacement of components (e.g. hand rails, safety ladders, light
poles); and rewrapping or replacement of steel cable straps on
dolphins. These repairs are described in greater detail in the Navy's
application but would not result in the take of marine mammals and are
not discussed further.
Operation of the following equipment types is not reasonably
expected to result in take of marine mammals and will not be discussed
further beyond the brief summaries provided below:
Jetting produces much lower sound levels (approximately
147.5 decibel (dB) Root Mean Square (RMS); NAVFAC SW, 2020) than
vibratory pile driving 166 dB RMS (Navy, 2015). The sounds produced by
jetting are of similar frequencies to the sounds produced by vessels,
and are anticipated to diminish to background noise levels (or be
masked by background noise levels) in Port Townsend Bay.
Hydraulic cutting would be used be used to assist with
removal of piles. Similar to jetting, the sounds produced by cutting
are of similar frequencies to the sounds produced by vessels (NAVFAC
SW, 2020), and are anticipated to diminish to background noise levels
(or be masked by
[[Page 74118]]
background noise levels) in Port Townsend Bay relatively close to the
Ammunition Wharf. Cutting of 24-inch concrete piles also produces much
lower sound levels (approximately 141.4 decibel (dB) Root Mean Square
(RMS); NAVFAC SW, 2020) than vibratory pile driving 166 dB RMS (Navy,
2015).
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
To characterize potential species occurrence, the Navy's
application utilized density information available for Puget Sound, and
recent research and survey information conducted on-site or in Puget
Sound. The Navy also discussed species occurrence with local species
experts and reviewed incidental sighting reports from the Orca Network
(Whidbey Island, WA) and Center for Whale Research (Friday Harbor, WA)
for verified or reasonably verified species presence, as well as
information on seasonal, intermittent, or unusual species occurrences.
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; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and
more general information about these species (e.g., physical and
behavioral descriptions) may be found on NMFS' website (https://www.fisheries.noaa.gov/find-species).
Table 2 lists all species 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 Endangered Species Act (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 expected to occur, 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 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 stocks managed under the MMPA in this region
are assessed in NMFS' U.S. Pacific Marine Mammal Stock Assessment
Report. All values presented in Table 2 are the most recent available
at the time of publication and are available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.
Table 2--Marine Mammal Species \4\ Likely To Occur Near the Project Area That May Be Taken by the Navy's Activities
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ESA/ MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
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Order Artiodactyla--Cetacea--Mysticeti (baleen whales)
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Family Eschrichtiidae:
Gray Whale...................... (Eschrichtius robustus) Eastern N Pacific...... -,-, N 26,960 (0.05, 25,849, 801 131
2016).
Family Balaenopteridae (rorquals):
Humpback Whale.................. Megaptera novaeangliae. Central America/ E, D, Y 1,496 (0.171, 1,284, 3.5 14.9
Southern Mexico- 2021).
California-Oregon-
Washington.
Mainland Mexico- T, D, Y 3,477 (0.101, 3,185, 43 22
California-Oregon- 2018).
Washington.
Hawaii................. -, -, N 11,278 (0.56, 7,265, 127 27.09
2020).
Minke Whale..................... Balaenoptera CA/OR/WA............... -, -, N 915 (0.792, 509, 2018) 4.1 >=0.59
acutorostrata.
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Odontoceti (toothed whales, dolphins, and porpoises)
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Family Phocoenidae (porpoises):
Dall's Porpoise................. Phocoenoides dalli..... CA/OR/WA............... -, -, N 16,498 (0.61, 10,286, 99 >=0.66
2019).
Harbor Porpoise................. Phocoena phocoena...... Washington Inland -, -, N 11,233 (0.37, 8,308, 66 >=7.2
Waters. 2015).
Family Delphinidae:
Killer Whale.................... Orcinus orca........... West Coast Transient... -, -, N 349 (N/A, 349, 2018).. 3.5 0.4
Eastern North Pacific E, D, Y 74 (N/A, 74, 2021).... 0.13 >=0.4
Southern Resident.
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Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and
sea lions):
CA Sea Lion..................... Zalophus californianus. U.S.................... -, -, N 257,606 (N/A,233,515, 14011 >320
2014).
Steller Sea Lion................ Eumetopias jubatus..... Eastern................ -, -, N 43,201 (N/A, 43,201, 2,592 112
2017).
Family Phocidae (earless seals):
Harbor Seal..................... Phoca vitulina......... Washington Northern -, -, N 11,036 \5\ (UNK, UNK, UND 9.8
Inland Waters. 1999).
[[Page 74119]]
Northern Elephant Seal.......... Mirounga angustirostris CA Breeding............ -, -, N 187,386 (NA, 85,369, 5122 13.7
2013).
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\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
\4\ 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
(https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/; Committee on Taxonomy (2022)).
\5\ The abundance estimate for this stock is greater than 8 years old and is therefore not considered current. PBR is considered undetermined for this
stock, as there is no current minimum abundance estimate for use in calculation. We nevertheless present the most recent abundance estimates, as these
represent the best available information for use in this document.
As indicated above, all nine species (with nine managed stocks) in
Table 2 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur. However, no take is
proposed for authorization for killer whales and humpback whales for
the reasons provided below.
Southern resident killer whales do occur occasionally in the waters
north of NAVMAG Indian Island although as of June 2023 they have not
been reported near Port Townsend since December 2020 and then only by
hydrophones so the exact locations are unknown (Orca Network, 2023). It
is unlikely any would occur close to the Ammunition Wharf. Occurrence
in the inland waters are low in the winter through early spring (Orca
Network, 2023), when project activities would occur. While critical
habitat has been designated in Puget Sound for southern resident killer
whales, the designation does not include the Port Townsend/Indian
Island/Walan Point naval restricted area which extends out 500 m from
the Ammunition Wharf (73 FR 78633; December 23, 2008). In contrast to
southern resident killer whales, which exclusively prey on fish, the
main diet of transient killer whales consists of marine mammals. Within
Puget Sound, transient killer whales primarily hunt pinnipeds and
porpoises, though some groups will occasionally target larger whales.
The seasonal movements of transients are largely unpredictable,
although there is a tendency to investigate harbor seal haulouts off
Vancouver Island more frequently during the pupping season in August
and September (Baird, 1994; Ford, 2014). The movements and locations of
southern resident killer whales are tracked daily by the Center for
Whale Research and the Orca Network, therefore, exposures to noise from
pile driving can be avoided if southern resident killer whales are
known to be near the project area.
Similarly, humpback whales are considered to be regular, but not
frequent visitors to Puget Sound, especially south of Admiralty Inlet.
Opportunistic sightings primarily occur April through July in Puget
Sound, although sightings have been reported in every month of the
year. In addition to the timing of the planned activity, which
minimizes potential for occurrence of humpback and killer whales, the
Navy proposes to implement shutdown procedures for all cetaceans as
needed to avoid harassment. For highly visible species, such as large
whales, this is expected to be successful in avoiding any potential for
take. No take of these species is anticipated or proposed for
authorization, and we do not discuss them further.
Gray Whale
Two North Pacific populations of gray whales are formally
recognized: the Western Pacific subpopulation (also known as the
Western North Pacific or the Korean-Okhotsk population) (WNP) that is
critically endangered and the Eastern Pacific population (also known as
the Eastern North Pacific or the California-Chukchi population) (ENP)
that appears to have recovered from exploitation and was removed from
listing under the ESA in 1994 (Carretta et al., 2016). The two
populations have historically been considered geographically isolated
from each other; however, data from satellite-tracked whales indicate
that there is some overlap between the stocks. Two WNP whales were
tracked from Russian foraging areas along the Pacific rim to Baja
California (Mate et al., 2011), and, in one case where the satellite
tag remained attached to the whale for a longer period, a WNP whale was
tracked from Russia to Mexico and back again (International Whaling
Commission [IWC, 2012]). Between 22-24 WNP whales are known to have
occurred in the eastern Pacific through comparisons of ENP and WNP
photo-identification catalogs (IWC, 2012; Weller et al., 2012; Burdin
et al., 2011). Urban et al. (2013) compared catalogs of photo-
identified individuals from Mexico with photographs of whales off
Russia and reported a total of 21 matches. Therefore, a portion of the
WNP population is assumed to migrate, at least in some years, to the
eastern Pacific during the winter breeding season. However, it is
extremely unlikely that a gray whale in close proximity to NAVMAG
Indian Island construction activity would be one of the few WNP whales
that have been documented in the eastern Pacific. The likelihood that a
WNP whale would be present in the vicinity of the proposed project is
insignificant and discountable, and WNP gray whales are omitted from
further analysis.
Eastern gray whales, however, are known to migrate along the U.S.
West Coast on both their northward and southward migrations. As the
majority of gray whales migrate past the Strait of Juan de Fuca in
route to or from their feeding or breeding grounds, a few of them enter
Washington inland waters to feed (Stout et al., 2001; Calambodkidis et
al., 2015). Gray whales are observed in Washington inland waters,
including Puget Sound in all months of the year (Calambokidis et al.,
2010; Orca Network, 2023) with peak numbers from March through June
(Calambokidis et al., 2010, 2015). Fewer than 20 gray whales are
documented in the inland waters of Washington and British Columbia each
year beginning in
[[Page 74120]]
January (Orca Network, 2011, as cited by Washington Department of Fish
and Wildlife [WDFW], 2012). Most whales sighted are part of a small
regularly occurring group of 6 to 10 gray whales that use mudflats in
the Whidbey Island and the Camano Island area as a springtime feeding
area (Calambokidis et al., 2010). Gray whales feed on benthic
invertebrates, including dense aggregations of ghost shrimp and
tubeworms (Weitkamp et al., 1992, Richardson, 1997).
Gray whales that are not identified with the regularly occurring
group in the Whidbey Island and Camano Island area are occasionally
sighted in Puget Sound. These whales are not associated with feeding
areas and are often emaciated (WDFW, 2012). Gray whales are expected to
occur in the waters surrounding NAVMAG Indian Island. They are expected
to occur primarily from March through June when in-water construction
work will not occur. Therefore, some exposure to individual gray whales
could occur over the duration of the project; however, project timing
will help to minimize potential exposures.
Minke Whale
Minke whales from California to Washington appear to be
behaviorally distinct from migratory whales further north (i.e., Alaska
stock). Animals from the California, Oregon, and Washington stock,
including Washington inland waters are considered ``resident''. Minke
whales appear to establish home ranges in the inland waters of
Washington (Dorsey, 1983; Dorsey et al., 1990). They are reported in
the inland waters year-round, although the majority of the records are
from March through November (Calambokidis & Baird, 1994). Minke whales
are sighted primarily in the San Juan Islands and Strait of Juan de
Fuca but are relatively rare in Puget Sound south of Admiralty Inlet
(Orca Network, 2023). In the Strait of Juan de Fuca, individuals move
within and between specific feeding areas around submarine banks (Stern
et al., 1990). Dorsey et al. (1990) noted minke whales feeding in
locations of strong tidal currents. Hoelzel et al. 16 (1989) reported
that 80 percent of feeding observations in the San Juan Islands were
over submarine slopes of moderate incline at a depth of about 20 m to
100 m. Three feeding grounds have been identified in the Strait of Juan
de Fuca and San Juan Islands area (Osborne et al., 1988; Hoelzel et
al., 1989; Dorsey et al., 1990; Stern et al., 1990). There is year-to-
year variation in the use of these feeding areas, and other feeding
areas probably exist (Osborne et al., 1988; Dorsey et al., 1990). A
review of Washington inland water sighting data from January 2005
through August 2012 indicates that Minke whales typically occur as lone
individuals or in small groups of two or three (Orca Network, 2023).
No minke whales have been reported in Port Townsend Bay although
they have been reported in the Strait of Juan de Fuca and north of Port
Townsend and along the western side of Whidbey Island near Smith Island
in October (Orca Network, 2023).
Based on the information presented, the number of minke whales
potentially present near NAVMAG Indian Island is expected to be very
low in October and unlikely from November through February (Orca
Network, 2023).
Dall's Porpoise
Dall's porpoise is one of the most common odontocete species in
North Pacific waters (Jefferson, 1991; 2 Ferrero & Walker, 1999;
Calambokidis & Barlow, 2004; Williams & Thomas, 2007). Dall's porpoise
is found from northern Baja California, Mexico, north to the northern
Bering Sea and south to southern Japan (Jefferson et al., 1993).
However, the species is only common between 32[deg] N lat. and 62[deg]
N lat. in the eastern North Pacific (Morejohn, 1979; Houck & Jefferson,
1999). Dall's porpoise are found in outer continental shelf, slope, and
oceanic waters, typically in temperatures less than 17 [deg]C (Houck &
Jefferson, 1999; Reeves et al., 2002; Jefferson et al., 2015).
Dall's porpoises may occur in Washington inland waters year-round,
but appear to be very rare (Evenson et al., 2016). Extensive aerial
surveys conducted in Puget Sound and Hood Canal in all seasons from
2013-2015 logged only one sighting of one individual (Jefferson et al.,
2016). Only four Dall's porpoise were detected in aerial surveys of the
northern inland waters of Washington (Strait of Juan de Fuca, San Juan
Islands, Strait of Georgia) during spring 2015 (Smultea et al., 2015).
Additional sightings have been reported in the Strait of Juan de Fuca
and Haro Strait between San Juan Island and Vancouver Island
(Nysewander et al., 2005; Orca Network, 2023). Tagging studies suggest
Dall's porpoises seasonally move between the Haro Strait area and the
Strait of Juan de Fuca or farther west (Hanson et al., 1998).
Dall's porpoise were detected in Puget Sound during aerial surveys
in winter (1993-2008) and summer (1992-1999) (Nysewander et al., 2005;
WDFW, 2008), with additional observations reported to Orca Network
(2023). During the surveys, Dall's porpoise were sighted in Puget Sound
as far south as Carr Inlet in southern Puget Sound and as far north as
Saratoga Passage, north of Naval Station (NAVSTA) Everett (Nysewander
et al., 2005; WDFW, 2008). Recent extensive aerial surveys of Puget
Sound and Hood Canal during 2013-2015 detected only one individual
(Jefferson et al., 2016), but did not specify its location. The number
of Dall's porpoises potentially present near NAVMAG Indian Island is
expected to be very low in any month.
Harbor Porpoise
In Washington inland waters, harbor porpoise are known to occur in
the Strait of Juan de Fuca and the San Juan Islands area year-round
(Calambokidis and Baird, 1994; Osmek et al., 1996; Carretta et al.,
2012). Harbor porpoises were historically one of the most commonly
observed marine mammals in Puget Sound (Scheffer and Slipp, 1948);
however, there was a significant decline in sightings beginning in the
1940s (Everitt et al., 1979; Calambokidis et al., 1992). Only a few
sightings were reported between the 1970s and 1980s (Calambokidis et
al., 1992; Osmek et al., 1996; Raum-Suryan and Harvey, 1998), and no
harbor porpoise sightings were recorded during multiple ship and aerial
surveys conducted in Puget Sound (including Hood Canal) in 1991 and
1994 (Calambokidis et al., 1992; Osmek et al., 1996).
Incidental sightings of marine mammals during aerial bird surveys
conducted as part of the Puget Sound Ambient Monitoring Program (PSAMP)
detected few harbor porpoises in Puget Sound between 1992 and 1999
(Nysewander et al., 2005). However, these sightings may have been
negatively biased due to the low elevation of the plane, which may have
caused an avoidance behavior. Since 1999, PSAMP data, stranding data,
and aerial surveys conducted from 2013 to 2016 documented increasing
numbers of harbor porpoise in Puget Sound, indicating that the species
is increasing in the area (Nysewander, 2008; WDFW, 2008; Jeffries,
2013; Smultea et al., 2017).
Little information is available on harbor porpoise occurrence
outside of Hood Canal and no site-specific information is available for
NAVMAG Indian Island. No harbor porpoises have been reported in Port
Townsend Bay although they have been reported just north of Port
Townsend and along Marrowstone Island as they move south into Puget
Sound (Orca Network, 2023). Based on the information presented, the
number of harbor porpoises present near
[[Page 74121]]
NAVMAG Indian Island is expected to be very low in any month and even
lower in winter months.
California Sea Lion
During the summer, California sea lions breed on islands from the
Gulf of California to the Channel Islands and forage in the Southern
California Bight. The primary rookeries are located on the California
Channel Islands of San Miguel, San Nicolas, Santa Barbara, and San
Clemente. In the nonbreeding season, adult and subadult males migrate
northward along the coast to central and northern California, Oregon,
Washington, and Vancouver Island, and return south in the spring
(DeLong et al., 2017; Weise and Harvey, 2008). Primarily male
California sea lions migrate into northwest waters with most adult
females with pups remaining in waters near their breeding rookeries off
the coasts of California and Mexico (Melin et al., 2000; Lowry and
Maravilla-Chavez, 2005; Kuhns and Costa., 2014; Lowry et al., 2017).
California sea lions also enter bays, harbors, and river mouths and
often haul out on artificial structures such as piers, jetties,
offshore buoys, and oil platforms.
Jeffries et al. (2000) and Jeffries (2012 personal communication)
identified dedicated, regular haulouts used by adult and sub-adult
California sea lions in Washington inland waters (See Figure 4-1 in the
Navy's application). California sea lions are typically present most of
the year except for mid-June through July in Washington inland waters,
with peak abundance between October and May (NMFS, 1997; Jeffries et
al., 2000). California sea lions would be expected to forage within the
area, following local prey availability.
Steller Sea Lion
The eastern stock of Steller sea lions is found along the coasts of
southeast Alaska to northern California where they occur at rookeries
and numerous haulout locations along the coastline (Jeffries et al.,
2000; Scordino, 2006). Male Steller sea lions often disperse widely
outside of the breeding season from breeding rookeries in northern
California (e.g., St. George Reef) and southern Oregon (e.g., Rogue
Reef) (Scordino, 2006; Wright et al., 2010). Based on mark recapture
sighting studies, males migrate back into these Oregon and California
locations from winter feeding areas in Washington, British Columbia,
and Alaska (Scordino, 2006).
In Washington, Steller sea lions use haulout sites primarily along
the outer coast from the Columbia River to Cape Flattery, as well as
along the Vancouver Island side of the Strait of Juan de Fuca (Jeffries
et al., 2000). A major winter haulout is located in the Strait of Juan
de Fuca at Race Rocks, British Columbia, Canada (Canadian side of the
Strait of Juan de Fuca) (Edgell & Demarchi, 2012). Numbers vary
seasonally in Washington with peak numbers present during the fall and
winter months and a decline in the summer months that corresponds to
the breeding season at coastal rookeries (approximately late May to
early June) (Jeffries et al., 2000). In Puget Sound, Jeffries (2012
personal communication) identified five winter haulout sites used by
adult and subadult (immature or pre-breeding animals) Steller sea
lions, ranging from immediately south of Port Townsend (near Admiralty
Inlet) to Olympia in southern Puget Sound (see Figure 4-1 in the Navy's
application). Numbers of animals observed at these sites ranged from a
few to less than 100 (Jeffries, 2012 personal communication). In
addition, Steller sea lions opportunistically haul out on various
navigational buoys in Admiralty Inlet south through southern Puget
Sound near Olympia (Jeffries, 2012 personal communication). One or two
animals occur on these buoys.
No haulouts are known in the immediate vicinity of NAVMAG Indian
Island; therefore, no shore-based surveys have been conducted there and
no opportunistic sightings have been reported. The nearest Steller sea
lion haul-outs to NAVMAG Indian Island is located on the east side of
Marrowstone Island, approximately 7 km away (Figure 4-1 in the Navy's
application). Monitoring during pile driving in 2015 and 2016 did not
observe any Steller sea lions hauled out on the Port Security Barrier
or swimming through the area (Navy, 2014, 2016, 2021). Therefore,
Steller sea lions are expected to be rare in the waters off NAVMAG
Indian Island.
Northern Elephant Seal
The northern elephant seal occurs almost exclusively in the eastern
and central North Pacific. Rookeries are located from central Baja
California, Mexico, to northern California (Stewart & Huber, 1993).
Adult elephant seals engage in two long migrations per year, one
following the breeding season, and another following the annual molt
(Stewart and DeLong, 1995; Robinson et al., 2012). Between the two
foraging periods they return to land to molt with females returning
earlier than males (March through April versus July through August).
After the molt, adults then return to their northern feeding areas
until the next winter breeding season. Breeding occurs from December to
March (Stewart & Huber, 1993). Juvenile elephant seals typically leave
the rookeries in April or May and head north, traveling an average of
900 to 1,000 km. Most elephant seals return to their natal rookeries
when they start breeding (Huber et al., 1991). Their foraging range
extends thousands of miles offshore into the central North Pacific.
Adults tend to stay offshore, but juveniles and subadults are often
seen along the coasts of Oregon, Washington, and British Columbia
(Condit & Le Boeuf, 1984; Stewart & Huber, 1993).
In Washington inland waters, there are regular haulout sites in the
Strait of Juan de Fuca at Smith and Minor Islands, Dungeness Spit, and
Protection Island that are thought to be used year-round (Jeffries et
al., 2000; Jeffries, 2012 personal communication) (Figure 4-1 in the
Navy's application). Pupping has occurred at these sites, as well as
Race Rocks on the British Columbia side of the Strait of Juan de Fuca
(Jeffries, 2012 personal communication).
No haulouts occur in Puget Sound with the exception of individual
elephant seals occasionally hauling out for 2 to 4 weeks to molt,
usually during the spring and summer and typically on sandy beaches
(Calambokidis & Baird, 1994). These animals are usually yearlings or
subadults and their haulout locations are unpredictable. Although
regular haul-outs occur in the Strait of Juan de Fuca, the occurrence
of elephant seals in Puget Sound is unpredictable and rare.
Pacific Harbor Seal
Harbor seals are a coastal species, rarely found more than 21 km
from shore, and frequently occupy bays, estuaries, and inlets (Baird,
2001). Individual seals have been observed several kilometers upstream
in coastal rivers (Baird, 2001). Ideal harbor seal habitat includes
haul-out sites, shelter during the breeding periods, and sufficient
food (Bj[oslash]rge, 2002). Harbor seals generally do not make
extensive pelagic migrations (i.e., less than 50 km; Baird, 2001),
Harbor seals have also displayed strong fidelity to haul-out sites.
Harbor seals are the most common, widely distributed marine mammal
found in Washington marine waters and are frequently observed in the
nearshore marine environment. They occur year-round and breed in
Washington. Numerous harbor seal haulouts occur in Washington inland
waters (Figure 4-1 in the Navy's application). Haulouts include
intertidal and subtidal rock outcrops, beaches, reefs, sandbars, log
[[Page 74122]]
booms, and floats. Numbers of individuals at haul-outs range from a few
to between 100 and 500 individuals (Jeffries et al., 2000). Harbor
seals are expected to occur year-round, the nearest documented haul-out
to NAVMAG Indian Island is Rat Island at the north end of NAVMAG Indian
Island approximately 2.4 km from the Ammunition Wharf. The haulout at
Rat Island is estimated to have less than 100 individuals (Jeffries,
2012 personal communication).
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 3.
Table 3--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 and Holt,
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 section later in this document includes a
quantitative analysis of the number of individuals that are expected to
be taken by this activity. The Negligible Impact Analysis and
Determination section considers the content of this section, the
Estimated Take section, and the Proposed Mitigation section, to draw
conclusions regarding the likely impacts of these activities on the
reproductive success or survivorship of individuals and 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.
Acoustic effects on marine mammals during the specified activities
can occur from impact pile driving and vibratory driving and removal.
The effects of underwater noise from the Navy's proposed activities
have the potential to result in Level A or Level B harassment of marine
mammals in the action areas.
Description of Sound Sources
The marine soundscape is comprised of both ambient and
anthropogenic sounds. Ambient sound is defined as the all-encompassing
sound in a given place and is usually a composite of sound from many
sources both near and far (American National Standards Institute
[ANSI], 1995). The sound level of an area is defined by the total
acoustical energy being generated by known and unknown sources. These
sources may include physical (e.g., waves, wind, precipitation,
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced
by marine mammals, fish, and invertebrates), and anthropogenic sound
(e.g., vessels, dredging, aircraft, construction).
The sum of the various natural and anthropogenic sound sources at
any given location and time--which comprise ``ambient'' or
``background'' sound--depends not only on the source levels (as
determined by current weather conditions and levels of biological and
shipping activity) but also on the ability of sound to propagate
through the environment. In turn, sound propagation is dependent on the
spatially and temporally varying properties of the water column and sea
floor, and is frequency-dependent. As a result of the dependence on a
large number of varying factors, ambient sound levels can be expected
to vary widely over both coarse and fine spatial and temporal scales.
Sound levels at a given frequency and location can vary by 10-20
decibels (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 activities 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 projects would
include impact and vibratory pile installation and vibratory removal.
The sounds produced by these activities fall into one of two general
sound types: impulsive and non-impulsive. Impulsive sounds (e.g.,
explosions,
[[Page 74123]]
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; National Institute for
Occupational Safety and Health [NIOSH], 1998; NMFS, 2018). Non-
impulsive sounds (e.g., machinery operations such as drilling or
dredging, vibratory pile driving, underwater chainsaws, and active
sonar systems) can be broadband, narrowband or tonal, brief or
prolonged (continuous or intermittent), and typically do not have the
high peak sound pressure with raid rise/decay time that impulsive
sounds do (ANSI 1995; NIOSH 1998; NMFS 2018). The distinction between
these two sound types is important because they have differing
potential to cause physical effects, particularly with regard to
hearing (e.g., Ward 1997 in Southall et al., 2007).
Two types of hammers would be used on these projects, impact and
vibratory. Impact hammers operate by repeatedly dropping and/or pushing
a heavy piston onto a pile to drive the pile into the substrate. Sound
generated by impact hammers is considered impulsive. Vibratory hammers
install piles by vibrating them and allowing the weight of the hammer
to push them into the sediment. Vibratory hammers produce non-
impulsive, continuous sounds. Vibratory hammering generally produces
sound pressure levels (SPLs) 10 to 20 dB lower than 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 Navy's proposed activities on
marine mammals could be generated from both non-acoustic and acoustic
stressors. Potential non-acoustic stressors include the physical
presence of the equipment, vessels, and personnel; however, we expect
that any animals that approach the project site(s) close enough to be
harassed due to the presence of equipment or personnel would be within
the Level B harassment zones from pile driving and would already be
subject to harassment from the in-water activities. Therefore, any
impacts to marine mammals are expected to primarily be acoustic in
nature. Acoustic stressors are generated by heavy equipment operation
during pile installation and removal (i.e., impact and vibratory pile
driving and removal).
Acoustic Impacts
The introduction of anthropogenic noise into the aquatic
environment from pile driving equipment is the primary means by which
marine mammals may be harassed from the Navy's specified activities. In
general, animals exposed to natural or anthropogenic sound may
experience physical and psychological effects, ranging in magnitude
from none to severe (Southall et al., 2007). Generally, exposure to
pile driving and removal and other construction noise has the potential
to result in auditory threshold shifts and behavioral reactions (e.g.,
avoidance, temporary cessation of foraging and vocalizing, changes in
dive behavior). Exposure to anthropogenic noise can also lead to non-
observable physiological responses such as an increase in stress
hormones. Additional noise in a marine mammal's habitat can mask
acoustic cues used by marine mammals to carry out daily functions such
as communication and predator and prey detection. The effects of pile
driving and demolition 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.
mother with calf), duration of exposure, the distance between the pile
and the animal, received levels, behavior at time of exposure, and
previous history with exposure (Wartzok et al., 2004; Southall et al.,
2007). Here we discuss physical auditory effects (threshold shifts)
followed by behavioral effects and potential impacts on habitat. No
physiological effects other than permanent threshold shift (PTS)
(discussed below) are anticipated or proposed to be authorized, and
therefore are not discussed further.
NMFS defines a noise-induced threshold shift (TS) as a change,
usually an increase, in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS, 2018). The amount of
threshold shift is customarily expressed in dB. A TS can be permanent
or temporary. As described in NMFS (2018), there are numerous factors
to consider when examining the consequence of TS, including, but not
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), likelihood an individual would be exposed for a long enough
duration or to a high enough level to induce a TS, the magnitude of the
TS, time to recovery (seconds to minutes or hours to days), the
frequency range of the exposure (i.e., spectral content), the hearing
and vocalization frequency range of the exposed species relative to the
signal's frequency spectrum (i.e., how animal uses sound within the
frequency band of the signal; e.g., Kastelein et al., 2014), and the
overlap between the animal and the source (e.g., spatial, temporal, and
spectral).
Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent,
irreversible increase in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS 2018). Available data from
humans and other terrestrial mammals indicate that a 40 dB TS
approximates PTS onset (see Ward et al., 1958, 1959; Ward, 1960; Kryter
et al., 1966; Miller, 1974; Ahroon et al., 1996; Henderson et al.,
2008). PTS levels for marine mammals are estimates, because there are
limited empirical data measuring PTS in marine mammals (e.g., Kastak et
al., 2008), largely due to the fact that, for various ethical reasons,
experiments involving anthropogenic noise exposure at levels inducing
PTS are not typically pursued or authorized (NMFS, 2018).
Temporary Threshold Shift (TTS)--A temporary, reversible increase
in the threshold of audibility at a specified frequency or portion of
an individual's hearing range above a previously established reference
level (NMFS, 2018). Based on data from cetacean TTS measurements (see
Southall et al., 2007), a TTS of 6 dB is considered the minimum TS
shift clearly larger than any day-to-day or session-to-session
variation in a subject's normal hearing ability (Schlundt et al., 2000;
Finneran et al., 2000, 2002). As described in Finneran (2016), marine
mammal studies have shown the amount of TTS increases with cumulative
sound exposure level (SELcum) in an accelerating fashion: At
low exposures with lower SELcum, the amount of TTS is
typically small and the growth curves have shallow slopes. At exposures
with higher SELcum, the growth curves become steeper and
approach linear relationships with the noise SEL.
Depending on the degree (elevation of threshold in dB), duration
(i.e., recovery time), and frequency range of TTS, and the context in
which it is experienced, TTS can have effects on marine mammals ranging
from discountable to serious (similar to those discussed in auditory
masking, below). For example, a marine mammal may be able to readily
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal
is traveling through the open ocean, where ambient noise is lower and
there are not as many
[[Page 74124]]
competing sounds present. Alternatively, a larger amount and longer
duration of TTS sustained during time when communication is critical
for successful mother/calf interactions could have more serious
impacts. We note that reduced hearing sensitivity as a simple function
of aging has been observed in marine mammals, as well as humans and
other taxa (Southall et al., 2007), so we can infer that strategies
exist for coping with this condition to some degree, though likely not
without cost.
Currently, TTS data only exist for four species of cetaceans
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor
porpoise, and Yangtze finless porpoise (Neophocoena asiaeorientalis))
and five species of pinnipeds exposed to a limited number of sound
sources (i.e., mostly tones and octave-band noise) in laboratory
settings (Finneran, 2015). TTS was not observed in trained spotted
(Phoca largha) and ringed (Pusa hispida) seals exposed to impulsive
noise at levels matching previous predictions of TTS onset (Reichmuth
et al., 2016). In general, harbor seals and harbor porpoises have a
lower TTS onset than other measured pinniped or cetacean species
(Finneran, 2015). The potential for TTS from impact pile driving
exists. After exposure to playbacks of impact pile driving sounds (rate
2,760 strikes/hour) in captivity, mean TTS increased from 0 dB after 15
minute exposure to 5 dB after 360 minute exposure; recovery occurred
within 60 minutes (Kastelein et al., 2016). Additionally, the existing
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).
The Navy proposes to use impact pile driving to install some piles
for these projects. There would likely be pauses in activities
producing the sound (e.g., impact pile driving) during each day. Given
these pauses and the fact that many marine mammals are likely moving
through the project areas 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; National Research
Council [NRC], 2005).
Disturbance may result in changing durations of surfacing and
dives, number of blows per surfacing, or moving direction and/or speed;
reduced/increased vocal activities; changing/cessation of certain
behavioral activities (such as socializing or feeding); visible startle
response or aggressive behavior (such as tail/fluke slapping or jaw
clapping); or avoidance of areas where sound sources are located.
Pinnipeds may increase their haulout time, possibly to avoid in-water
disturbance (Thorson and Reyff, 2006). Behavioral responses to sound
are highly variable and context-specific and any reactions depend on
numerous intrinsic and extrinsic factors (e.g., species, state of
maturity, experience, current activity, reproductive state, auditory
sensitivity, time of day), as well as the interplay between factors
(e.g., Richardson et al., 1995; Wartzok et al., 2004; Southall et al.,
2007; Weilgart, 2007; Archer et al., 2010). Behavioral reactions can
vary not only among individuals but also within an individual,
depending on previous experience with a sound source, context, and
numerous other factors (Ellison et al., 2012), and can vary depending
on characteristics associated with the sound source (e.g., whether it
is moving or stationary, number of sources, distance from the source).
In general, pinnipeds seem more tolerant of, or at least habituate more
quickly to, potentially disturbing underwater sound than do cetaceans,
and generally seem to be less responsive to exposure to industrial
sound than most cetaceans. Please see Appendices B and C of Southall et
al. (2007) for a review of studies involving marine mammal behavioral
responses to sound.
Disruption of feeding behavior can be difficult to correlate with
anthropogenic sound exposure, so it is usually inferred by observed
displacement from known foraging areas, the appearance of secondary
indicators (e.g., bubble nets or sediment plumes), or changes in dive
behavior. As for other types of behavioral response, the frequency,
duration, and temporal pattern of signal presentation, as well as
differences in species sensitivity, are likely contributing factors to
differences in response in any given circumstance (e.g., Croll et al.,
2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko et al.,
2007). A determination of whether foraging disruptions incur fitness
consequences would require information on or estimates of the energetic
requirements of the affected individuals and the relationship between
prey availability, foraging effort and success, and the life history
stage of the animal.
Stress Responses--An animal's perception of a threat may be
sufficient to trigger stress responses consisting of some combination
of behavioral responses, autonomic nervous system responses,
neuroendocrine responses, or immune responses (Moberg, 2000). In many
cases, an animal's first and sometimes most economical (in terms of
energetic costs) response is behavioral avoidance of the potential
stressor. Autonomic nervous system responses to stress typically
involve changes in heart rate, blood pressure, and gastrointestinal
activity. These responses have a relatively short duration and may or
may not have a significant long-term effect on an animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that
are affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been
implicated in failed reproduction, altered metabolism, reduced immune
competence, and behavioral disturbance (e.g., Moberg, 1987; Blecha
2000). Increases in the circulation of glucocorticoids are also equated
with stress (Romano et al., 2004).
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and ``distress'' is the cost of
the response. During a stress response, an animal uses glycogen stores
that can be quickly replenished once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other functions. This state of
distress will last until the animal replenishes its energetic reserves
sufficient to restore normal function.
[[Page 74125]]
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well-studied through
controlled experiments and for both laboratory and free-ranging animals
(e.g., Holberton et al., 1996; Jessop et al., 2003; Krausman et al.,
2004; Lankford et al., 2005). Stress responses due to exposure to
anthropogenic sounds or other stressors and their effects on marine
mammals have also been reviewed (Fair and Becker, 2000; Romano et al.,
2002b) and, more rarely, studied in wild populations (e.g., Romano et
al., 2002a). For example, Rolland et al. (2012) found that noise
reduction from reduced ship traffic in the Bay of Fundy was associated
with decreased stress in North Atlantic right whales. These and other
studies lead to a reasonable expectation that some marine mammals will
experience physiological stress responses upon exposure to acoustic
stressors and that it is possible that some of these would be
classified as ``distress.'' In addition, any animal experiencing TTS
would likely also experience stress responses (NRC, 2003), however
distress is an unlikely result of these projects based on observations
of marine mammals during previous, similar projects in the area.
Masking--Sound can disrupt behavior through masking, or interfering
with, an animal's ability to detect, recognize, or discriminate between
acoustic signals of interest (e.g., those used for intraspecific
communication and social interactions, prey detection, predator
avoidance, navigation) (Richardson et al., 1995). Masking occurs when
the receipt of a sound is interfered with by another coincident sound
at similar frequencies and at similar or higher intensity, and may
occur whether the sound is natural (e.g., snapping shrimp, wind, waves,
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar,
seismic exploration) in origin. The ability of a noise source to mask
biologically important sounds depends on the characteristics of both
the noise source and the signal of interest (e.g., signal-to-noise
ratio, temporal variability, direction), in relation to each other and
to an animal's hearing abilities (e.g., sensitivity, frequency range,
critical ratios, frequency discrimination, directional discrimination,
age or TTS hearing loss), and existing ambient noise and propagation
conditions. Masking of natural sounds can result when human activities
produce high levels of background sound at frequencies important to
marine mammals. Conversely, if the background level of underwater sound
is high (e.g., on a day with strong wind and high waves), an
anthropogenic sound source would not be detectable as far away as would
be possible under quieter conditions and would itself be masked. The
Puget Sound area contains active commercial shipping, ferry operations,
and commercial fishing as well as numerous recreational and other
commercial vessels, and background sound levels in the area are already
elevated.
Airborne Acoustic Effects--Pinnipeds that occur near the project
site could be exposed to airborne sounds associated with pile driving
and removal that have the potential to cause behavioral harassment,
depending on their distance from pile driving activities. Cetaceans are
not expected to be exposed to airborne sounds that would result in
harassment as defined under the MMPA.
Airborne noise would primarily be an issue for pinnipeds that are
swimming or hauled out near the project site within the range of noise
levels elevated above the acoustic criteria. We recognize that
pinnipeds in the water could be exposed to airborne sound that may
result in behavioral harassment when looking with their heads above
water. Most likely, airborne sound would cause behavioral responses
similar to those discussed above in relation to underwater sound. For
instance, anthropogenic sound could cause hauled out pinnipeds to
exhibit changes in their normal behavior, such as reduction in
vocalizations, or cause them to temporarily abandon the area and move
further from the source. However, these animals would likely previously
have been taken because of exposure to underwater sound above the
behavioral harassment thresholds, which are generally larger than those
associated with airborne sound. There are no haulouts in close
proximity to the project site. Thus, the behavioral harassment of these
animals is already accounted for in these estimates of potential take.
Therefore, we do not believe that authorization of incidental take
resulting from airborne sound for pinnipeds is warranted, and airborne
sound is not discussed further here.
Marine Mammal Habitat Effects
The Navy's proposed construction activities could have localized,
temporary impacts on marine mammal habitat, including prey, by
increasing in-water sound pressure levels and slightly decreasing water
quality. Increased noise levels may affect acoustic habitat (see
masking discussion above) and adversely affect marine mammal prey in
the vicinity of the project areas (see discussion below). During impact
and vibratory pile driving or removal, elevated levels of underwater
noise would ensonify the project areas where both fishes and mammals
occur and could affect foraging success. Additionally, marine mammals
may avoid the area during construction, however, displacement due to
noise is expected to be temporary and is not expected to result in
long-term effects to the individuals or populations. Construction
activities are of short duration and would likely have temporary
impacts on marine mammal habitat through increases in underwater and
airborne sound.
A temporary and localized increase in turbidity near the seafloor
would occur in the immediate area surrounding the area where piles are
installed or removed. In general, turbidity associated with pile
installation is localized to about a 25-ft (7.6-m) radius around the
pile (Everitt et al., 1980). The sediments of the project site will
settle out rapidly when disturbed. Cetaceans are not expected to be
close enough to the pile driving areas to experience effects of
turbidity, and any pinnipeds could avoid localized areas of turbidity.
Local currents are anticipated to disburse any additional suspended
sediments produced by project activities at moderate to rapid rates
depending on tidal stage. Therefore, we expect the impact from
increased turbidity levels to be discountable to marine mammals and do
not discuss it further.
In-Water Construction Effects on Potential Foraging Habitat--The
area likely impacted by the project is relatively small compared to the
available habitat in Port Townsend Bay and the larger Puget Sound. The
area is highly influenced by anthropogenic activities. The total
seafloor area affected by pile installation and removal is a small area
compared to the vast foraging area available to marine mammals in the
area. At best, the impact area provides marginal foraging habitat for
marine mammals and fishes. Furthermore, pile driving and removal at the
project site would not obstruct long-term movements or migration of
marine mammals.
Avoidance by potential prey (i.e., fish or, in the case of
transient killer whales, other marine mammals) of the immediate area
due to the temporary loss of this foraging habitat is also possible.
The duration of fish and marine mammal avoidance of this area after
pile driving stops is unknown, but a rapid return to normal
recruitment, distribution, and behavior is anticipated. Any behavioral
avoidance
[[Page 74126]]
by fish or marine mammals of the disturbed area would still leave
significantly large areas of fish and marine mammal foraging habitat in
the nearby vicinity.
In-Water Construction Effects on Potential Prey--Sound may affect
marine mammals through impacts on the abundance, behavior, or
distribution of prey species (e.g., crustaceans, cephalopods, fish,
zooplankton, other marine mammals). Marine mammal prey varies by
species, season, and location. Here, we describe studies regarding the
effects of noise on known marine mammal prey other than other marine
mammals (which have been discussed earlier).
Fish utilize the soundscape and components of sound in their
environment to perform important functions such as foraging, predator
avoidance, mating, and spawning (e.g., Zelick and Mann, 1999; Fay,
2009). Depending on their hearing anatomy and peripheral sensory
structures, which vary among species, fishes hear sounds using pressure
and particle motion sensitivity capabilities and detect the motion of
surrounding water (Fay et al., 2008). The potential effects of noise on
fishes depends on the overlapping frequency range, distance from the
sound source, water depth of exposure, and species-specific hearing
sensitivity, anatomy, and physiology. Key impacts to fishes may include
behavioral responses, hearing damage, barotrauma (pressure-related
injuries), and mortality.
Fish react to sounds which are especially strong and/or
intermittent low-frequency sounds, and behavioral responses such as
flight or avoidance are the most likely effects. Short duration, sharp
sounds can cause overt or subtle changes in fish behavior and local
distribution. The reaction of fish to noise depends on the
physiological state of the fish, past exposures, motivation (e.g.,
feeding, spawning, migration), and other environmental factors.
Hastings and Popper (2005) identified several studies that suggest fish
may relocate to avoid certain areas of sound energy. Additional studies
have documented effects of pile driving on fish; several are based on
studies in support of large, multiyear bridge construction projects
(e.g., Scholik and Yan, 2001, 2002; Popper and Hastings, 2009). Several
studies have demonstrated that impulse sounds might affect the
distribution and behavior of some fishes, potentially impacting
foraging opportunities or increasing energetic costs (e.g., Fewtrell
and McCauley, 2012; Pearson et al., 1992; Skalski et al., 1992).
However, some studies have shown no or slight reaction to impulse
sounds (e.g., Pena et al., 2013; Wardle et al., 2001; Jorgenson and
Gyselman, 2009).
SPLs of sufficient strength have been known to cause injury to fish
and fish mortality. However, in most fish species, hair cells in the
ear continuously regenerate and loss of auditory function likely is
restored when damaged cells are replaced with new cells. Halvorsen et
al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours
for one species. Impacts would be most severe when the individual fish
is close to the source and when the duration of exposure is long.
Injury caused by barotrauma can range from slight to severe and can
cause death, and is most likely for fish with swim bladders. Barotrauma
injuries have been documented during controlled exposure to impact pile
driving (Halvorsen et al., 2012b; Casper et al., 2013).
The most likely impact to fishes from pile driving and removal and
construction activities at the project areas would be temporary
behavioral avoidance of the area. The duration of fish avoidance of
this area after pile driving stops is unknown, but a rapid return to
normal recruitment, distribution, and behavior is anticipated.
Construction activities, in the form of increased turbidity, have
the potential to adversely affect forage fish in the project areas.
Forage fish form a significant prey base for many marine mammal species
that occur in the project areas. Increased turbidity is expected to
occur in the immediate vicinity (on the order of 10 ft (3 m) or less)
of construction activities. However, suspended sediments and
particulates are expected to dissipate quickly within a single tidal
cycle. Given the limited area affected and high tidal dilution rates
any effects on forage fish are expected to be minor or negligible.
Finally, exposure to turbid waters from construction activities is not
expected to be different from the current exposure; fish and marine
mammals in the project area are routinely exposed to substantial levels
of suspended sediment from natural and anthropogenic sources.
In summary, given the brief and intermittent duration (24 days
between October 1 and January 15) of sound associated with individual
pile driving events and the relatively small areas being affected, pile
driving activities associated with the proposed actions are not likely
to have a permanent, adverse effect on any fish habitat, or populations
of fish species. Any behavioral avoidance by fish of the disturbed area
would still leave significantly large areas of fish and marine mammal
foraging habitat in the nearby vicinity. Thus, we conclude that impacts
of the specified activities are not likely to have more than short-term
adverse effects on any prey habitat or populations of prey species.
Further, any impacts to marine mammal habitat are not expected to
result in significant or long-term consequences for individual marine
mammals, or to contribute to adverse impacts on their populations.
Estimated Take
This section provides an estimate of the number of incidental takes
proposed for authorization through this proposed rule, which will
inform both NMFS' consideration of ``small numbers,'' and the
negligible impact determinations.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes would primarily be by Level B harassment, as use
of the acoustic sources (i.e., vibratory and impact pile driving
equipment) has the potential to result in disruption of behavioral
patterns for individual marine mammals. There is also some potential
for auditory injury (Level A harassment) to result, primarily for
harbor seals (phocids) because these animals are known to occur in
close proximity to the pile driving locations. Auditory injury is
unlikely to occur for other hearing groups or species. 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
[[Page 74127]]
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.
The Navy's proposed activity includes the use of continuous
(vibratory hammer source type) and impulsive (impact hammer) 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). The Navy's
proposed activity includes the use of impulsive (impact hammer) and
non-impulsive (vibratory hammer) sources.
These thresholds are provided in the Table 4 below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS' 2018 Technical Guidance, which may be accessed at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 218 dB; Cell 8: LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that are used in estimating the area ensonified above the
acoustic thresholds, including source levels and transmission loss
coefficient.
The sound field in the project area is the existing background
noise plus additional construction noise from the proposed project.
Marine mammals are expected to be affected by sound generated by the
primary components of the project (i.e., impact and vibratory pile
driving).
Data from prior pile driving projects at the Naval Base Kitsap
Bangor and Bremerton waterfronts were reviewed in the analysis. The
representative sound pressure levels used in the analysis are presented
in Table 5.
For vibratory pile driving distances to the PTS thresholds, the
transmission loss (TL) model described above incorporated the auditory
weighting functions for each hearing group using a single frequency as
described in the NMFS Spreadsheet (NMFS, 2018). For impact pile driving
distances to the PTS thresholds for 36-inch steel pile and 24-inch
concrete pile, the TL model described above incorporated frequency
weighting adjustments by applying the auditory weighting function over
the entire 1-second SEL spectral data sets from impact pile driving. If
a source level for a particular pile size was not available, the next
highest source level was used to produce a conservative estimate of
areas above threshold values.
[[Page 74128]]
In order to calculate distances to the Level A harassment and Level
B harassment thresholds for the methods and piles being used in this
project, the Navy used acoustic monitoring data from various similar
locations to develop source levels for the different pile types, sizes,
and methods proposed for use (Table 5).
Table 5--Source Levels for Proposed Removal and Installation Activities
----------------------------------------------------------------------------------------------------------------
Peak \1\ (dB SEL \2\ (dB re
Pile diameter RMS \1\ (dB re re 1 1 [micro]Pa\2\
(inches) 1 [micro]Pa) [micro]Pa) sec)
----------------------------------------------------------------------------------------------------------------
Impact Installation.......... Concrete........ 24 174 189 167
Steel Pipe \2\.. 36 192 211 184
Vibratory Removal............ Steel Fender.... 14 150 N/A N/A
Vibratory Installation....... Steel Fender.... 14 150 N/A N/A
Composite Fender 18.75 150 N/A N/A
Steel pipe...... 36 167 N/A N/A
----------------------------------------------------------------------------------------------------------------
Source: Navy, 2015; Navy, 2017, 2018, NAVFAC SW, 2020; WDOT, 2017.
Key: N/A = not applicable; RMS = root mean square; SEL = sound exposure level.
\1\ Sound pressure levels are presented for a distance of 10 m from the pile. RMS and Peak levels are relative
to 1 [mu]Pa and cumulative SEL levels are relative to 1 [mu]Pa2 sec; and
\2\ Values modeled for impact driving 36-inch steel piles will be reduced by 8 dB for noise exposure modeling to
account for attenuation from a bubble curtain.
A bubble curtain will be used to minimize the noise generated by
impact driving of steel pipe piles. Note that impact pile driving of
steel piles would only occur if it is necessary to install the 36-inch
steel piles and none are currently planned to be installed. If steel
piles became necessary then a maximum of 2 piles would be installed
within the 5-year effective period of the LOA. The bubble curtain is
expected to attenuate impact pile driving sound levels an average of 8
dB based on past performance during similar Navy projects in Puget
Sound (Navy, 2015); therefore, 8 dB was subtracted from values in Table
5 prior to modeling the behavioral and PTS thresholds for impact pile
driving steel pipe piles. For the cumulative SEL PTS thresholds,
auditory weighting functions were applied to the attenuated one-second
SEL spectra for steel pipe piles.
Level B Harassment Zones
TL is the decrease in acoustic intensity as an acoustic pressure
wave propagates out from a source. TL parameters vary with frequency,
temperature, sea conditions, current, source and receiver depth, water
depth, water chemistry, and bottom composition and topography. The
general formula for underwater TL is:
TL = B * Log10 (R1/R2),
Where:
TL = transmission loss in dB,
B = transmission loss coefficient (for practical spreading equals
15),
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement.
The recommended TL coefficient for most nearshore environments is
the practical spreading value of 15. This value results in an expected
propagation environment that would lie between spherical and
cylindrical spreading loss conditions, which is the most appropriate
assumption for the Navy' proposed activities. The Level B harassment
zones and areas for the Navy's proposed activities are shown in Table
6.
Table 6--Calculated Radial Distance(s) to Underwater Marine Mammal Vibratory Pile Driving Noise Thresholds and
Areas Encompassed Within Threshold Distance
----------------------------------------------------------------------------------------------------------------
Behavioral disturbance--Level B harassment (120 dB RMS)
Type -------------------------------------------------------------------------
Radial distance to threshold Area encompassed by threshold
----------------------------------------------------------------------------------------------------------------
14-inch steel H fender pile 1,000 m............................ 1.8 km.
(vibratory).
18.75-in composite fender pile 1,000 m............................ 1.8 km.
(vibratory).
36-inch steel (vibratory)............. 13.6 km............................ 54 km.
----------------------------------------------------------------------------------------------------------------
Level A Harassment Zones
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 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 and vibratory driving, 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.
The isopleths generated by the User Spreadsheet used the same TL
coefficient as the Level B harassment zone calculations (i.e., the
practical spreading value of 15). Inputs used in the User Spreadsheet
(e.g., number of piles per day, duration and/or strikes per pile) are
presented in Table 7. The maximum RMS SPL/SEL SPL and resulting
isopleths are reported below in Table 8 and Table 9. The maximum
[[Page 74129]]
RMS SPL value was used to calculate Level A harassment isopleths for
vibratory pile driving while the single strike SEL SPL value was used
to calculate Level A harassment isopleths for impact pile driving
activities. Note that Peak PTS thresholds were smaller for all pile
sizes and hearing groups compared to SEL SPL values.
Table 7-- Parameters of Pile Driving Activity Used in User Spreadsheet
--------------------------------------------------------------------------------------------------------------------------------------------------------
Removal or
installation of steel
24-inch concrete 36-inch steel Fender pile 14-inch steel or 18.75- 36-inch steel
inch composites
--------------------------------------------------------------------------------------------------------------------------------------------------------
Type of installation/removal.... Impact.................. Impact.................. Vibratory............. Vibratory............. Vibratory.
Source Level.................... 167 SEL/189 PK.......... 184 SEL/211 PK.......... 144 RMS............... 150 RMS............... 192 RMS
Weighting Factor Adjustment 2....................... 2....................... 2.5................... 2.5................... 2.5.
(kHz).
(a) Number of strikes/pile...... 1,000................... 500..................... ...................... ...................... ..................
(a) Activity Duration (min) ........................ ........................ 10.................... 10.................... 45.
within 24-h period.
Propagation (xLogR)............. 15...................... 15...................... 15.................... 15.................... 15.
Piles per day................... 2....................... 1....................... 2..................... 2..................... 1.
Distance of source level 10...................... 10...................... 10.................... 10.................... 10.
measurement (meters).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 8--Calculated Radial Distance(s) to Impact Pile Driving Noise Thresholds for Level A and Level B Harassment and Associated Areas \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment pinnipeds Level A harassment cetaceans Behavioral disturbance level B (160 dB
----------------------------------------------------------------------------------- RMS)
---------------------------------------
Harbor seal Sea lion LF MF HF Radial distance to Area encompassed
threshold by threshold
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-inch concrete............. 29 m........... 2 m............ 54 m........... 2 m........... 64 m.......... 86 m.............. 0.02 km\2\.
36-inch steel................ 182 m.......... 13 m........... 243 m.......... 8 m........... 256 m......... 398 m............. 0.5 km\2\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Calculations based on SELCUM threshold criteria shown in Table 4 and source levels shown in Table 5.
Table 9--Calculated Radial Distance(s) to Vibratory Pile Driving Noise Thresholds for Level A and Level B Harassment and Associated Areas \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment pinnipeds Level A harassment cetaceans Behavioral disturbance level B (120 dB
----------------------------------------------------------------------------------- RMS)
Type ---------------------------------------
Phocids Otariids LF MF HF Radial distance to Area encompassed
threshold by threshold
--------------------------------------------------------------------------------------------------------------------------------------------------------
14-inch steel H fender pile <1 m........... <1 m........... <1 m........... <1 m.......... <1 m.......... 1,000 m........... 1.8 km\2\.
(vibratory).
18.75-in composite fender <1 m........... <1 m........... <1 m........... <1 m.......... <1 m.......... 1,000 m........... 1.8 km\2\.
pile (vibratory).
36-inch steel (vibratory).... 4 m............ <1 m........... 7 m............ <1 m.......... 11 m.......... 13.6 km........... 54 km\2\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Vibratory pile driving would only occur if it is necessary to install 36 inch steel piles, none are currently planned to be installed. If steel
piles became necessary then only up to eight would be installed within the 5 years of the LOA.
Marine Mammal Occurrence and Take Calculation and Estimation
In this section we provide information about the occurrence of
marine mammals, including density or other relevant information that
will inform the take calculations. We describe how the information
provided above is brought together to produce a quantitative take
estimate for each species.
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 per year where N = density estimate (animals per
km\2\) used for each species.
Note that the area of the harassment zone is truncated by land
masses surrounding the area (i.e., Whidbey Island, Port Townsend
mainland, and Indian Island). Densities are shown in Table 10.
In addition, local occurrence data from prior monitoring efforts,
discussed in the next paragraph, was used as a supplement to estimate
potential occurrence of harbor seals within the Level A harassment
zones. This method is conservative in providing estimates of potential
exposure above the total given using the aforementioned equation that
we equate here with Level A harassment.
For harbor seals, which were the primary species found within 1,000
m of the Ammunition Wharf during pile driving monitoring from 2014-2016
and 2020 (Navy, 2014, 2016, 2021), a daily rate of harbor seal
occurrence was determined for vibratory installation of fender piles
for the Level A harassment zones. Only harbor seals were observed
during pile driving monitoring (Navy, 2016, 2020) and weekly marine
mammal surveys (2022) at NAVMAG Indian Island Ammunition Wharf with the
exception of a single harbor porpoise and a single California sea lion.
The site-specific data was used to estimate take only for harbor seals
at a rate of 0.5 seals per day from concrete impact driving and eight
seals per day from steel impact driving, based on the different
estimated zone sizes.
[[Page 74130]]
During the site-specific monitoring efforts discussed above, only
harbor seals were observed during pile driving monitoring (Navy, 2016,
2020) and weekly marine mammal surveys (2022) at NAVMAG Indian Island
Ammunition Wharf, with the exception of a single harbor porpoise and a
single California sea lion. For species other than harbor seal--for
which use of the available density information and the equation given
above provide low calculated take estimates (described in species-
specific sections below)--it was assumed between one (i.e., gray whale,
minke whale) and three animals would be taken over the duration of the
proposed rule (by Level B harassment only). For California sea lions,
Steller sea lions, and northern elephant seals it was assumed that
there would be 1 take per year from concrete/fender pile installation
(by Level B harassment only). It was also assumed that there would be 1
additional take per year by Level B harassment during steel pile
installation for the northern elephant seal. In contrast to pinniped
species, Dall's porpoises and harbor porpoises often occur in pods of
two to four porpoises. Therefore, it was assumed that there would be up
to three takes per year by concrete/fender pile installation for each
species with three additional takes per year only for Dall's porpoises
per year due to steel pile installation. All takes are assumed to be by
Level B harassment only, based on the assumed rarity of occurrence and
the Navy's proposal to implement shutdown procedures for all cetaceans
at the estimated Level B harassment distance.
The density estimates given in Table 10 come from the Pacific
NMSDD, NAVFAC Pacific Technical Report (Navy, 2020) and Smultea et al.
(2017) (for harbor porpoise). The seasonal density value for each
species during the in-water work window at each site was used in the
marine mammal take assessment calculation.
Note that The largest Level B harassment zone will be generated
during vibratory driving. The Level B harassment zone for an impact
hammer will be encompassed by the larger Level B harassment zone from
the vibratory driver. Impact pile driving was assumed to be one pile
per day but actual daily production rates may be higher with a maximum
of two per day, resulting in fewer in-water pile driving days. It was
assumed that 22 days of concrete pile installation would occur. This is
a conservative estimate based on past work at NAVMAG. There would be up
to 22 concrete piles (24-in) driven over the maximum of 22 days per
year over 5 years with up to two 24-inch concrete piles driven per day
(1-2 piles installed per day; mean of 1.8 piles installed per day)
depending on accessing the wharf deck, weather, harbor seal delays, or
equipment issues. Note that this conservative estimate of pile driving
days is used solely to assess the number of days during which pile
driving could occur if production was delayed due to equipment failure,
safety, etc. In a real construction situation, pile driving production
rates would be maximized when possible.
Table 10--Marine Mammal Species Densities in Project Area
----------------------------------------------------------------------------------------------------------------
Density (October-February) * animals
Species Region location km\2\
----------------------------------------------------------------------------------------------------------------
Gray whale.............................. North Puget Sound.......... Zero (within 1,000 m) \1\ 0.00048 (Fall
and Winter).\2\
Minke Whale............................. Puget Sound................ Zero (within 1,000 m) \1\ 0.00045
(Annual).\2\
Harbor porpoise......................... North Puget Sound.......... 1.16 (Annual).2 3
Dall's porpoise......................... Puget Sound................ 0.00045 (Annual) \2\.
Steller sea lion........................ Puget Sound................ Zero (within 1,000 m) \2\ 0.0478 (Fall
and Winter).\1\
California sea lion..................... Puget Sound................ Zero (within 1,000 m) \1\ 0.2211 (Fall)
\2\ 0.1100 (Winter).\2\
Northern elephant seal.................. Puget Sound................ Zero (within 1,000 m) \1\ 0.0000
(Annual).\2\
Harbor Seal............................. North Puget Sound.......... 14-18.75 inch Fender Pile Driving: \1\
Within 10 m = 0.0 seals/day (Level A
zone).
Within 1,000 m = 15.54 seals per day
(Level B harassment zone).
........................... 24 inch Concrete Impact Pile Driving: \1\
Within 29 m = 0.5 seals/day (Level A
harassment zone).
Combine with the larger fender pile
vibratory Level B harassment zone.
........................... 36 inch Steel Impact Pile Driving: \1\
Within 182 m = 8 seals/day (Level A
harassment zone).
Combine with the larger vibratory zone
for Level B harassment.
........................... 36 inch Steel Vibratory Pile Driving:
Within 10 m = 0.0 seals/day (Level A
zone).
Within 13.6 km (54 km\2\) = 2.83 seals/
km\2\.
----------------------------------------------------------------------------------------------------------------
* 13.6 km with an area of 54 km\2\ (a large part of the area was truncated by land masses) was used for 36-inch
steel pile vibratory installation.
Sources: \1\ Navy, 2014, 2016; 2021; \2\ NMSDD (Navy, 2020), \3\ Smultea et al. (2017).
It is important to note that the successful implementation of
mitigation methods (i.e., visual monitoring and the use of shutdown
zones) is expected to result in no Level A harassment exposure to all
marine mammals except harbor seals because the injury zones and
behavioral zones will be monitored during pile driving. Harbor seal
Level A harassment exposure will be limited to the smallest extent
practicable. The exposure assessment estimates the numbers of
individuals potentially exposed to the effects of pile driving noise
exceeding NMFS established thresholds. Results from acoustic impact
exposure assessments should be regarded as conservative overestimates
that are strongly influenced by limited marine mammal data, the
assumption that marine mammals will be present during pile driving, and
the assumptions that the maximum number of piles will be extracted or
installed.
Gray Whale
Most gray whales in Puget Sound utilize the feeding areas in
northern Puget Sound around Whidbey Island and in Port Susan in March
through June with a few individual sightings occurring year-round that
are not always associated with feeding areas. Therefore, gray whales
are included in the proposed take authorization. The majority of in-
water work will occur during the fall and winter when gray whales are
less likely to be present in Puget Sound. Therefore, based on a low
probability of occurrence within the vibratory harassment zones, the
Navy used the formula described above to
[[Page 74131]]
calculate estimated exposures. The formula estimated zero takes per
year; however, due to the uncertainty of gray whale movements and the
large area of exposure during vibratory driving of 36-inch steel piles,
the Navy has requested and NMFS proposes to authorize take by Level B
harassment at a rate of one animal per year.
To protect gray whales from noise impacts, the Navy will implement
a shutdown if protected species obervers (PSOs) see gray whales
approaching or within any harassment zone. A PSO will be stationed at
locations from which the injury zone and behavioral zone for impact and
vibratory pile driving are visible and will implement shutdown if a
whale approaches or enters either zone. With the implementation of
monitoring, even if a whale enters an injury zone, shutdown would occur
before cumulative exposure to noise levels that would result in PTS
could occur. Because pile driving will be shut down if whales are in
the injury zone, no Level A harassment take has been requested or is
being proposed for authorization by NMFS. In summary, the Navy has
requested, and NMFS proposes, to authorize one take of gray whale by
Level B harassment each year for the duration of the 5-year LOA.
Minke Whale
Minke whales in Washington inland waters typically feed in the
areas around the San Juan Islands and along banks in the Strait of Juan
de Fuca. Minke whales are infrequent visitors to Puget Sound,
especially east of Admiralty Inlet. When present, minke whales are
usually seen singly or in pairs. Therefore, based on a low probability
of occurrence within the vibratory harassment zones, the Navy used the
same equation discussed above to calculate estimated exposures. The
formula estimated zero takes annually for the duration of the LOA.
However, due to the uncertainty of minke whale movements and the large
area of exposure during vibratory driving of 36-inch steel piles, the
Navy requested takes for the exposure of one minke whale per year for
the duration of the 5-year LOA.
To protect minke whales from noise impacts, the Navy will implement
a shutdown if PSOs see minke whales approaching or within any
harassment zone. A PSO will be stationed at locations from which the
injury zone and behavioral zone for impact and vibratory pile driving
are visible and will implement shutdown if a whale approaches or enters
either zone. PSOs may be stationed on boats to observe a greater
portion of the shutdown zone than is visible from land-based locations.
With the implementation of monitoring, even if a whale enters an injury
zone, shutdown would occur before cumulative exposure to noise levels
that would result in PTS could occur. Because pile driving will be shut
down if whales are in the injury zone, no Level A harassment take has
been requested or is being proposed for authorization by NMFS. In
summary, although minke whales are rare in the project area, the Navy
has requested and NMFS proposes to authorize one take of minke whale by
Level B harassment each year for the duration of the 5-year LOA.
Dall's Porpoise
Dall's porpoises are most abundant in the Strait of Juan de Fuca
and Haro Strait in the San Juan Islands area, but may be present in
Puget Sound year-round. Group size is usually two to four, although
larger groups are often sighted (Anderson et al., 2018). In Puget
Sound, the Navy has estimated that Dall's porpoise density is 0.045
animals/km\2\, although they have not been reported near NAVMAG Indian
Island in recent years and their occurrence in both the Salish Sea and
Puget Sound appears to be declining (Smultea et al., 2015; Evenson et
al., 2016; Jefferson et al., 2016). The Navy used the formula described
previously to calculate potential exposures. The formula estimated zero
takes. Due to the uncertainty of Dall's porpoise movements and the
large estimated harassment area during vibratory driving, the Navy
assumed, and NMFS concurred, that there would be three takes from work
on the fender piles and three takes from work on the steel piles each
year, by Level B harassment only.
To protect Dall's porpoises from noise impacts, the Navy will
implement a shutdown if PSOs see porpoises approaching or inside of any
harassment zone. A PSO will be stationed at locations from which the
harassment zones for impact and vibratory pile driving are visible and
will implement shutdown if a porpoise approaches or enters any zone.
With the implementation of monitoring, even if a Dall's porpoise enters
an injury zone, shutdown would occur before cumulative exposure to
noise levels that would result in PTS could occur. Because pile driving
will be shut down if porpoises are in the injury zone, no Level A
harassment take has been requested or is proposed for authorization. In
summary, although Dall's porpoises are rare in the project area, the
Navy has requested, and NMFS proposes, to authorize take of 30 Dall's
porpoises (6 per year) by Level B harassment over the 5-year LOA
period.
Harbor Porpoise
Harbor porpoises may be present in all major regions of Puget Sound
throughout the year. Group sizes ranging from 1 to 150 individuals were
reported in aerial surveys conducted from summer 2013 to spring 2016,
but mean group size was 1.7 animals (Smultea et al., 2017). The
estimated harbor porpoise density in inland waters is provided in Table
10. The estimated exposure equation described previously was employed
resulting in 125 takes per year from steel vibratory driving. Take from
concrete/fender vibratory driving was calculated to be 0.05 exposures
per year. However, the Navy requested authorization of three takes per
year resulting from this activity as a precaution. Note that harbor
porpoises were not observed during pile driving monitoring at NAVMAG
Indian Island ammunition wharf from 2014 to 2016 (Navy, 2014; Navy
2016), but one was observed in 2020 within 200 m of the Wharf (Navy,
2021).
The Navy will implement a shutdown if porpoises are seen by PSOs
entering or within any harassment zone in order to protect harbor
porpoises from noise impacts. A monitor will be stationed at locations
from which the injury and behavioral harassment zones for impact and
vibratory pile driving are visible and will implement shutdown if a
porpoise approaches or enters any harassment zone. With the
implementation of monitoring, even if a harbor porpoise enters an
injury zone, shutdown would occur before cumulative exposure to noise
levels that would result in PTS could occur. Because pile driving will
be shut down if porpoises are in the injury zone, no Level A harassment
take has been requested or is proposed for authorization. In summary,
the Navy has requested, and NMFS proposes, to authorize take of up to
640 harbor porpoises by Level B harassment (3 per year for work on
concrete/fender piles and 125 per year from for work on steel piles)
for the duration of the 5-year LOA.
California Sea Lion
California sea lions occur in Puget Sound from approximately August
to June. This species occasionally hauls out on the port security
barriers at NAVMAG Indian Island. These haulouts are adjacent to, in,
or near the Level B harassment zones, so exposure may occur if animals
move through Level B harassment zones during impact or
[[Page 74132]]
vibratory pile driving activities. California sea lions were not
observed during previous pile driving monitoring at NAVMAG Indian
Island ammunition wharf in 2014 to 2016 (Navy, 2014; Navy 2016), but
one was observed during 2020 (Navy, 2021). Although calculated take was
zero, reflecting their unlikely occurrence, Level B harassment
exposures for the concrete and fender pile driving were estimated as
one sea lion per year. Exposure estimates for vibratory driving of
steel piles utilized the estimated exposure equation, resulting in
estimated take of 17.88 sea lions per year, which was rounded up to 18
sea lion takes per year. Because a Level A harassment injury zone can
be effectively monitored and a shutdown zone will be implemented, no
take by Level A harassment is anticipated or proposed for
authorization. Based on the aforementioned considerations, NMFS
proposes to authorize take of 95 California sea lions (1 per year by
work on concrete/fender piles and 18 per year from work on steel
piles), by Level B harassment only, for the duration of the 5-year LOA.
Steller Sea Lion
Steller sea lions occur seasonally in Puget Sound primarily from
September through May. Take may occur if these animals move through
Level B harassment zones during impact or vibratory pile driving.
Although their occurrence is unlikely, the Navy assumed that there
would be one Level B harassment take from concrete and fender pile
driving per year. Level B harassment exposure estimates for steel piles
utilized the exposure estimate equation described previously using
densities from Table 10 resulting in an estimated take of 5.16 animals
per your rounded to 5 takes. Steller sea lions were not observed during
previous monitoring at NAVMAG Indian Island ammunition wharf in 2014 to
2016 (Navy, 2014, 2016, 2021). Because the Level A harassment injury
zone is small under all driving scenarios, it can be effectively
monitored. A shutdown will be implemented if animals approach the
injury zone and no exposure to Level A harassment noise levels is
anticipated at any location. In summary, the Navy has requested, and
NMFS proposes, to authorize take of up to 30 Steller sea lions (five
for work on concrete/fender piles over 5 years and 25 for work on steel
piles over 5 years) by Level B harassment for the duration of the 5-
year LOA.
Northern Elephant Seal
Northern elephant seals are considered rare visitors to Puget
Sound. No regular elephant seal haul outs occur in Puget Sound,
although individual elephant seals have been detected hauling out for 2
to 4 weeks to molt, usually during the spring and summer. Haul out
locations are unpredictable, but only one record is known for a Navy
installation. The Navy reports a density of 0.0 in Puget Sound (Navy,
2020). However, because there are occasional sightings in Puget Sound,
the Navy assumed that there would be one exposure from concrete/fender
driving and one exposure from steel driving during each year of the
LOA. Because elephant seals are rare in the project area and monitoring
and shutdown measures will be implemented, no Level A harassment
exposure is anticipated. In summary, the Navy has requested, and NMFS
is proposing, to authorize take of up to 10 northern elephant seals (2
per year) by Level B harassment for the duration of the 5-year LOA.
Pacific Harbor Seal
Pacific harbor seals are expected to occur year-round at NAVMAG
Indian Island. This species hauls out regularly at Rat Island adjacent
to the northeastern end of NAVMAG Indian Island year-round with a dip
in numbers in winter months. Harbor seals are most likely to be exposed
to Level A harassment noise when they swim through the area near the
Ammunition Wharf during impact pile driving (182 m for steel impact
driving and 29 m for concrete impact driving). Pile driving will
shutdown whenever a seal is detected by monitors nearing or within the
injury zone, but harbor seals can dive for up to 15 minutes and may not
be detected until they have been within the injury zone for a
sufficient period of time to incur PTS. For most pile driving
activities, exposure of harbor seals to pile driving noise will be
limited to Level B harassment. Level B harassment exposure estimates
for vibratory driving were determined using the formula of Level B
harassment zone area x density x days of vibratory pile driving. The
Navy has calculated take by Level B harassment of 1,710 harbor seals
during vibratory installation of fender piles (342 per year), and 1,530
harbor seals during vibratory pile driving of steel piles (306 per
year). Therefore, the Navy has requested, and NMFS proposes, to
authorize take of up to 3,240 Pacific harbor seals by Level B
harassment for the duration of the LOA. In addition, the Navy has
requested and NMFS is proposing to authorize up to 135 harbor seal
takes (27 per year) by Level A harassment during the 5-year LOA. This
is based on the daily average of site-specific observations from
several seasons of pile driving monitoring at the Ammunition Wharf and
weekly surveys conducted at NAVMAG Indian Island provided above.
Observations of seals within 29 m would be calculated to a mean of
seals per day within the Level A harassment zone. (Using the density
value would underestimate the number of seals in that small zone.) This
assumption results in 11 Level A harassment takes per year (0.5 seals/
day for 22 days) for impact driving of concrete piles (55 takes for 5
years) and 16 takes per year (8 seals/day for 2 days) for impact
driving of steel piles (80 takes over 5 years).
The annual and total number of takes requested by the Navy and
proposed for authorization by NMFS are shown in Table 11 and Table 12.
Table 11--Proposed Annual Take by Level A and Level B Harassment and Percentage of Stock Abundance for Authorized Species/Stocks
--------------------------------------------------------------------------------------------------------------------------------------------------------
Exposures
----------------------------------------------------------------------------------------------------------
24 Inch concrete piles and/or 36 Inch steel piles (up to 2
14-in/18.75-inch fender piles piles/year) Percent of
Species (up to 22 piles/year) -------------------------------- Total stock/distinct
-------------------------------- Level B annual Population population
Level B impact vibratory and Level A impact segmant (DPS)
or vibratory Level A Impact impact per year
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray Whale................................... 0 0 1 0 1 26,960 <0.01
Minke Whale.................................. 0 0 1 0 1 915 <0.01
Dall's Porpoise.............................. 3 0 3 0 3 16,498 <0.01
Harbor Porpoise.............................. 3 0 125 0 128 11,233 1.11
California Sea Lion.......................... 1 0 18 0 19 257,606 <0.01
Steller Sea Lion............................. 1 0 5 0 6 43,201 <0.01
[[Page 74133]]
Northern Elephant Seal....................... 1 0 1 0 2 187,386 <0.01
Pacific Harbor Seal.......................... 342 11 306 16 675 11,036 6.11
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 12--Total 5-Year Proposed Takes
[Level A Harassment and Level B Harassment]
----------------------------------------------------------------------------------------------------------------
Level A Level B
Species Stock harassment harassment Total 5-year
----------------------------------------------------------------------------------------------------------------
Gray Whale............................ Eastern North Pacific... .............. 5 5
Minke Whale........................... California/Oregon/ .............. 5 5
Washington.
Dall's Porpoise....................... California/Oregon/ .............. 30 30
Washington.
Harbor Porpoise....................... Washington Inland Waters .............. 640 640
California Sea Lion................... United States........... .............. 95 95
Steller Sea Lion...................... Eastern United States... .............. 30 30
Northern Elephant Seal................ California Breeding..... .............. 10 10
Pacific Harbor Seal................... Washington Northern 135 3,240 3,375
Inland Waters.
----------------------------------------------------------------------------------------------------------------
Proposed Mitigation
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, impact on
operations.
In order to limit impacts to marine mammals, vibratory installation
will be used by the Navy to the extent practicable to drive steel piles
to minimize high sound pressure levels associated with impact pile
driving. Jetting will also be used to the extent possible to install
concrete piles in order to minimize higher sound pressure levels
associated with impact pile driving. Note that a draft monitoring plan
will be submitted in the spring at least 90 days prior to the start of
the in-water work period (October) during the first year of the project
(2024). The final monitoring plan will be prepared and submitted to
NMFS within 30 days following receipt of comments on the draft plan
from NMFS.
The Navy will ensure that construction supervisors and crews, the
monitoring team, and relevant Navy staff are trained and prior to the
start of construction activity subject to this rule, so that
responsibilities, communication procedures, monitoring protocols, and
operational procedures are clearly understood. New personnel joining
during the project will be trained prior to commencing work.
Shutdown Zones
Before the commencement of in-water construction activities, the
Navy would establish shutdown zones for all impact and pile driving
activities. The purpose of a shutdown zone is generally to define an
area within which shutdown of the activity would occur upon sighting of
a marine mammal (or in anticipation of an animal entering the defined
area). Shutdown zones will vary based on the activity type and marine
mammal hearing group but will include all areas where the underwater
sound pressure levels are anticipated to equal or exceed the Level A
harassment (injury) criteria for marine mammals. The shutdown zone will
always be a minimum of 10 m to prevent injury from physical interaction
of marine mammals with construction equipment. The Level A harassment
zones are based on the maximum calculated radius for pinnipeds and
cetaceans, specifically harbor porpoises, during installation of 36-
inch steel piles and 24-inch concrete piles with impact techniques, and
the Level B harassment zone for impact and vibratory pile installation.
Injury to harbor seals from noise due to impact and vibratory pile
driving and physical interaction with construction equipment will be
minimized to the extent practicable by implementing a shutdown if the
animals are observed to be swimming towards the injury zone. For steel
pile impact driving, to the
[[Page 74134]]
extent possible, PSOs would initiate shutdown when harbor seals enter
the injury zone; however, because of the size of the zone and the
inherent difficulty in monitoring harbor seals, a highly mobile
species, it may not be practical, which is why Level A harassment take
is proposed for authorization.
The Navy would establish shutdown zones for all marine mammals for
which take has not been authorized or for which incidental take has
been authorized but the authorized number of takes has been met. These
zones are equivalent to the Level B harassment zones for each activity.
If such animals are sighted within the vicinity of the project areas
and are approaching the Level B harassment zone, the Navy would shut
down the pile driving equipment to avoid possible take of these
species.
Pile driving activities will cease if any cetaceans authorized for
take are seen approaching or entering any harassment zone. Work will be
halted and delayed until either the animal has voluntarily left and
been visually confirmed beyond the injury zone or visual portion of the
Level B harassment zone or 15 minutes have passed without re-detection
of the animal. Additionally, if a shutdown zone is obscured by fog or
poor lighting conditions, pile driving will not be initiated until the
entire shutdown zone is visible.
If a pinniped approaches or enters a shutdown zone during pile
impact or vibratory driving, work will be halted and delayed until
either the animal has voluntarily left and been visually confirmed
beyond the shutdown zone or 15 minutes have passed without re-detection
of the animal. If a pinniped is observed in the Level B harassment
zone, but not approaching or entering the shutdown zone, the work will
be allowed to proceed without cessation of pile driving. Marine mammal
behavior will be monitored and documented.
Table 13--Shutdown and Harassment Zones
----------------------------------------------------------------------------------------------------------------
Shutdown zone (m) Level B
Pile size and type ------------------------------------------------ harassment
Cetaceans Harbor seal Sea lion zone (m)
----------------------------------------------------------------------------------------------------------------
24-inch Concrete Impact......................... 90 30 10 90
36-inch Steel Impact............................ 400 200 20 400
36-inch Steel Vibratory......................... 13,600 10 10 13,600
Fender Vibratory................................ 1,000 10 10 1,000
----------------------------------------------------------------------------------------------------------------
At minimum, the shutdown zone for all hearing groups and all
activities would be 10 m. For in-water heavy machinery work other than
pile driving (e.g., standard barges, etc.), if a marine mammal comes
within 10 m, operations would cease and vessels would reduce speed to
the minimum level required to maintain steerage and safe working
conditions. This type of work could include, for example, the movement
of the barge to the pile location or positioning of the pile on the
substrate via a crane.
Pre-Activity Monitoring
Prior to the start of daily in-water construction activity, or
whenever a break in pile driving of 30 minutes or longer occurs, PSOs
would observe the shutdown and Level B harassment 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 zones listed in
Table 13, pile driving activity would be delayed or halted. If pile
driving is delayed or halted due to the presence of a marine mammal,
the activity would not commence or resume until either the animal has
voluntarily exited and been visually confirmed beyond the shutdown
zones or 15 minutes have passed without re-detection of the animal. If
work ceases for more than 30 minutes, the pre-activity monitoring of
the shutdown zones would commence. A determination that the shutdown
zone is clear must be made during a period of good visibility (i.e.,
the entire shutdown zone and surrounding waters must be visible to the
naked eye).
Monitoring will take place from 30 minutes prior to initiation
through 30 minutes post-completion of pile driving. Prior to the start
of pile driving, the shutdown zone will be monitored for 30 minutes to
ensure that the shutdown zone is clear of marine mammals. Pile driving
will only commence once PSOs have declared the shutdown zone clear of
marine mammals.
Soft Start
Soft-start procedures are used 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 three strikes from the hammer at reduced
energy, followed by a 30-second waiting period, then two subsequent
reduced-energy strike sets. 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.
Bubble Curtain
Should the use of 36-inch steel piles be necessary, a bubble
curtain will be used for all impact driving of steel piles to attenuate
noise. Because of the relatively low underwater noise levels associated
with impact driving of concrete piles, bubble curtains are not proposed
for impact installation of concrete piles.
A bubble curtain would be employed during impact installation or
proofing of steel pile where water depths are greater than 0.67 m. 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. A bubble curtain is usually a ring
or series of stacked rings that are placed around a pile along the
pile's entire length under water. The rings are made of tubing which
has small puncture holes through which compressed air is pumped. As the
compressed air bubbles flow from the tubing, they create an air barrier
that impedes the sound produced during pile driving. 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
[[Page 74135]]
parts of the ring or other objects would prevent full mudline contact.
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 adverse 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 LOA for an activity, section 101(a)(5)(A) 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:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the activity; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
How anticipated responses to stressors impact either: (1)
long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and,
Mitigation and monitoring effectiveness.
The Navy will submit a Marine Mammal Monitoring Plan to NMFS for
approval at least 90 days in advance of the start of the first year of
construction.
Visual Monitoring
Monitoring must be conducted during pile driving
activities by qualified, NMFS-approved PSOs, in accordance with the
following conditions: PSOs must be independent of the activity
contractor (for example, employed by a subcontractor) and have no other
assigned tasks during monitoring periods.
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.
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.
Where a team of three or more PSOs is required, a lead PSO
or monitoring coordinator must be designated. The lead PSO must have
prior experience performing the duties of a PSO during construction
activity pursuant to a NMFS-issued incidental take authorization.
PSOs must be approved by NMFS prior to beginning any
activity subject to this proposed rule.
All PSOs shall be trained in marine mammal identification and
behaviors, and satisfy the following criteria:
Visual acuity in both eyes (correction is permissible)
sufficient to discern moving targets at the water's surface with
ability to estimate target size and distance. Use of binoculars or
spotting scope may be necessary to correctly identify the target.
Advanced education in biological science, wildlife
management, mammalogy or related field (Bachelor's degree or higher is
preferred).
Experience and ability to conduct field observations and
collect data according to assigned protocols (this may include academic
experience).
Experience or training in the field identification of
marine mammals (cetaceans and pinnipeds).
Sufficient training, orientation or experience with vessel
operation and pile driving operations to provide for personal safety
during observations.
Writing skills sufficient to prepare a report of
observations. Reports should include such information as the number,
type, and location of marine mammals observed; the behavior of marine
mammals in the area of potential sound effects during construction;
dates and times when observations and in-water construction activities
were conducted; dates and times when in-water construction activities
were suspended because of marine mammals, etc.
Ability to communicate orally, by radio or in person, with
project personnel to provide real time information on marine mammals
observed in the area and necessary actions, as needed.
During pile driving activities, the Navy will assign PSOs to
monitor the identified harassment zones. The number and placement of
PSOs will vary depending upon the pile size, location, and number of
piles being installed or removed. In order to effectively monitor the
shutdown and Level B harassment zones, PSOs will be positioned at the
best practicable vantage points, taking into consideration security,
safety, and space limitations. The PSOs will be stationed on the pier,
vessel, on shore, or on the pile driving barge in a location that will
provide adequate visual coverage for the identified harassment zones.
During pile driving, at least one PSO will be stationed on a vessel if
practicable.
Monitoring would be conducted 30 minutes before, during, and 30
minutes after all in water construction activities. In addition, PSOs
would record all incidents of marine mammal occurrence, regardless of
distance from activity, and would document any behavioral reactions in
concert with distance from piles being driven or removed.
Reporting
The Navy must submit a draft monitoring report to NMFS within 90
calendar days of the completion of each construction year. A draft
comprehensive 5-year summary report must also be submitted to NMFS
within 90 days of the end of the project. The reports must detail the
monitoring protocol and summarize the data recorded during monitoring.
Final annual reports and the final comprehensive report must be
prepared and submitted within 30 days following resolution of any NMFS
comments on the draft report. If no comments are received from NMFS
within 30 days of receipt of the draft report, the report must be
considered final. If comments are received, a final report addressing
NMFS comments must be submitted within 30 days after receipt of
[[Page 74136]]
comments. The marine mammal report would include an overall description
of work completed, a narrative regarding marine mammal sightings, and
associated PSO data sheets. Specifically, the report would include:
Dates and times (begin and end) of all marine mammal
monitoring;
Construction activities occurring during each daily
observation period, including: (a) How many and what type of piles were
driven or removed and the method (i.e., impact or vibratory); and (b)
the total duration of time for each pile (vibratory driving) number of
strikes for each pile (impact driving);
PSO locations during marine mammal monitoring; and
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.
In addition, for each observation of a marine mammal, the marine
mammal report would include 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 location of each observed marine mammal
relative to the pile being driven for each sighting;
Estimated number of animals (min/max/best estimate);
Estimated number of animals by cohort (adults, juveniles,
neonates, group composition, etc.);
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);
Number of marine mammals detected within the harassment
zones, by species; and
Detailed information about implementation of any
mitigation (e.g., shutdowns and delays), a description of specified
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
reports would constitute the final reports. If comments are received, a
final report addressing NMFS' comments would be required to be
submitted within 30 days after receipt of comments. All PSO datasheets
and/or raw sighting data would be submitted with the draft marine
mammal report.
Reporting of Injured or Dead Marine Mammals
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, the Navy must report the
incident to NMFS Office of Protected Resources (OPR)
([email protected]), NMFS (301-427-8401) and to the
NMFS Northwest Regional Stranding Coordinator as soon as feasible. If
the death or injury was clearly caused by the specified activity, the
Navy must immediately cease the specified activities until NMFS OPR is
able to review the circumstances of the incident and determine what, if
any, additional measures are appropriate to ensure compliance with the
terms of this rule. The Navy will not resume their activities until
notified by NMFS. The report must include the following information:
1. Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
2. Species identification (if known) or description of the
animal(s) involved;
3. Condition of the animal(s) (including carcass condition if the
animal is dead);
4. Observed behaviors of the animal(s), if alive;
5. If available, photographs or video footage of the animal(s); and
6. General circumstances under which the animal was discovered.
Negligible Impact Analysis and Determination
NMFS has defined negligible impact as an impact resulting from the
specified activity that cannot be reasonably expected to, and is not
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
taken through harassment, NMFS considers other factors, such as the
likely nature of any 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 discussion of our analysis applies to the
species listed in Table 12, 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
among species, stocks, or groups of species, anticipated responses of
individual animals to activities, and/or impacts of expected take on
the population (due to differences in population status, or impacts on
habitat), the outliers are described independently in the analysis
below.
Pile driving 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 and Level B harassment from underwater sounds generated by
pile driving. Potential takes could occur if marine mammals are present
in zones ensonified above the thresholds for Level A and Level B
harassment, identified above, while activities are underway.
No serious injury or mortality would be expected even in the
absence of the proposed mitigation measures. During all impact driving,
implementation of soft-start procedures and monitoring of established
shutdown zones will be required, significantly reducing the possibility
of injury. Given sufficient notice through use of soft-start (for
impact driving), marine mammals are expected to move away from an
irritating sound source before it becomes potentially injurious. In
addition, PSOs will be stationed within the project area whenever pile
driving activities are underway. Depending on the activity, the Navy
will employ land-based PSOs to ensure all monitoring and shutdown zones
are properly observed.
[[Page 74137]]
For monitoring of larger harassment zones, the Navy would employ
vessel-based PSOs if practicable. Some harbor seals could be exposed to
Level A harassment levels of noise when they swim through the area near
the Ammunition Wharf during impact pile driving. Pile driving will shut
down whenever a seal is detected by PSOs nearing or within the injury
zone, but harbor seals can dive for up to 15 minutes and may not be
detected. Any animals 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 frequency range
of the energy produced by pile driving (i.e., the low-frequency region
below 2 kHz), not severe hearing impairment or impairment in the range
of greatest hearing sensitivity. If hearing impairment does occur, it
is most likely that the affected animal would lose a few dBs 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, given sufficient
notice through use of soft-start, marine mammals would be likely to
move away from a sound source that represents an aversive stimulus,
especially when the sound source is at levels that would be expected to
result in PTS. For most pile driving activities, exposure of harbor
seals to pile driving noise will be minimized to short-term behavioral
harassment (Level B harassment).
Exposures to elevated sound levels produced during pile driving
activities may cause behavioral disturbance of some individuals, but
the behavioral disturbances are expected to be mild and temporary.
However, as described previously, the mitigation and monitoring
measures are expected to further reduce the likelihood of injury as
well as reduce behavioral disturbances.
Effects on individuals that are taken by Level B harassment, as
enumerated in the Estimated Take section, on the basis of reports in
the literature as well as monitoring from other similar activities,
will likely be limited to reactions such as increased swimming speeds,
increased surfacing time, or decreased foraging (if such activity were
occurring) (e.g., Thorson and Reyff, 2006). Most likely, individual
animals will 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
along both Atlantic and Pacific coasts, which have taken place with no
known long-term adverse consequences from behavioral harassment. These
reactions and behavioral changes are expected to subside quickly when
the exposures cease. Level B harassment will be minimized 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, particularly as
the project is located on a waterfront with vessel traffic from both
Navy and non-Navy activities.
The project is also not expected to have significant adverse
effects on any marine mammal habitat. The Navy's proposed pile driving
activities and associated impacts will occur within a limited portion
of the confluence of the Puget Sound-Port Townsend Bay area. The
project activities will not modify existing marine mammal habitat since
the project will occur within the same footprint as existing marine
infrastructure. Impacts to the immediate substrate during installation
and removal of piles are anticipated, but these would be limited to
minor, temporary suspension of sediments, which could impact water
quality and visibility for a short amount of time, but which would not
be expected to have any effects on individual marine mammals. The
nearshore and intertidal habitat where the project will occur is an
area of consistent vessel traffic from Navy and non-Navy vessels, and
some local individuals would likely be somewhat habituated to the level
of activity in the area, further reducing the likelihood of more severe
impacts. The closest pinniped haulout, Rat Island, is used by harbor
seals and is 2.4 km from the Ammunition Wharf. However, for the reasons
described immediately above (including the nature of expected responses
and the duration of the project), impacts to reproduction or survival
of individuals are not anticipated, and are not expected to have
effects on the species or stock. There are no other biologically
important areas for marine mammals near the project area.
Impacts to marine mammal prey species are expected to be minor and
temporary. Overall, the area impacted by the project is very small
compared to the available habitat in Port Townsend Bay and larger Puget
Sound. The most likely impact to prey will be temporary behavioral
avoidance of the immediate area. During pile driving activities, it is
expected that some fish and marine mammals would temporarily leave the
area of disturbance, thus impacting marine mammals' foraging
opportunities in a limited portion of the foraging range; but, because
of the short duration of the activities and the relatively small area
of the habitat that may be affected, the impacts to marine mammal
habitat are not expected to cause significant or long-term negative
consequences.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
this activity are not expected to adversely affect the species or stock
through effects on annual rates of recruitment or survival:
No mortality is anticipated or authorized;
No Level A harassment is anticipated or authorized with
the exception of limited take of harbor seals;
Anticipated incidents of Level B harassment consist of, at
worst, temporary modifications in behavior;
The required mitigation measures (i.e., shutdown zones)
are expected to be effective in reducing the effects of the specified
activity;
Minimal impacts to marine mammal habitat/prey are
expected; and
There are no known biologically important areas in the
vicinity of the project, with the exception of one harbor seal haulout
(Rat Island). However, as described above, exposure to the work
conducted in the vicinity of the haulout is not expected to impact the
reproduction or survival of any individual seals.
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 small numbers of incidental take may be
authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the
[[Page 74138]]
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.
Take of eight marine mammal stocks proposed for authorization will
comprise no more than 6.11 percent of a single stock abundance (Pacific
harbor seal) as shown in Table 11. The number of animals proposed for
authorization to be taken from these stocks would be considered small
relative to the relevant stock's abundances even if each estimated take
occurred to a new individual, which is an unlikely scenario. Based on
the analysis contained herein of the proposed activity (including the
mitigation and monitoring measures) and the anticipated take of marine
mammals, NMFS preliminarily finds that small numbers of marine mammals
will be taken relative to the population size of the affected species
or stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
determined that the total taking of affected species or stocks would
not have an unmitigable adverse impact on the availability of such
species or stocks for taking for subsistence purposes.
Adaptive Management
The regulations governing the take of marine mammals incidental to
Navy construction activities would contain an adaptive management
component. The reporting requirements associated with this rule are
designed to provide NMFS with monitoring data from completed projects
to allow consideration of whether any changes are appropriate. The use
of adaptive management allows NMFS to consider new information from
different sources to determine (with input from the Navy regarding
practicability) on an annual or biennial basis if mitigation or
monitoring measures should be modified (including additions or
deletions). Mitigation measures could be modified if new data suggests
that such modifications would have a reasonable likelihood of reducing
adverse effects to marine mammals and if the measures are practicable.
The following are some of the possible sources of applicable data
to be considered through the adaptive management process: (1) Results
from monitoring reports, as required by MMPA authorizations; (2)
results from general marine mammal and sound research; and (3) any
information which reveals that marine mammals may have been taken in a
manner, extent, or number not authorized by these regulations or LOAs
issues pursuant to these regulations.
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 proposed rules, NMFS consults
internally whenever we propose to authorize take for endangered or
threatened species, in this case with the NMFS West Coast Regional
Office.
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.
Request for Information
NMFS requests interested persons to submit comments, information,
and suggestions concerning the Navy request and the proposed
regulations (see ADDRESSES). All comments will be reviewed and
evaluated as we prepare a final rule and make final determinations on
whether to issue the requested authorization. This proposed rule and
referenced documents provide all environmental information relating to
our proposed action for public review.
Classification
The Office of Management and Budget has determined that this
proposed rule is not significant for purposes of Executive Order 12866.
Pursuant to section 605(b) of the Regulatory Flexibility Act (RFA),
the Chief Counsel for Regulation of the Department of Commerce has
certified to the Chief Counsel for Advocacy of the Small Business
Administration that this proposed rule, if adopted, would not have a
significant economic impact on a substantial number of small entities.
The Navy is the sole entity that would be subject to the requirements
in these proposed regulations, and the Navy is not a small governmental
jurisdiction, small organization, or small business, as defined by the
RFA. Because of this certification, a regulatory flexibility analysis
is not required and none has been prepared.
This proposed rule does not contain a collection-of-information
requirement subject to the provisions of the Paperwork Reduction Act
(PRA) because the applicant is a Federal agency.
Dated: October 23, 2023.
Jonathan M. Kurland,
Acting Deputy Assistant Administrator for Regulatory Programs, National
Marine Fisheries Service.
List of Subjects in 50 CFR Part 217
Administrative practice and procedure, Exports, Fish, Imports,
Marine mammals, Penalties, Reporting and recordkeeping requirements,
Transportation, Wildlife.
For reasons set forth in the preamble, NMFS proposed to revise
subpart of 50 CFR part 217 as follows:
PART 217--REGULATIONS GOVERNING THE TAKE OF MARINE MAMMALS
INCIDENTAL TO SPECIFIED ACTIVITIES
0
1. The authority citation for part 217 continues to read as follows:
Authority: 16 U.S.C. 1361 et seq., unless otherwise noted.
0
2. Revised subpart I to part 217 to read as follows:
Subpart I--Taking and Importing Marine Mammals Incidental to U.S.
Navy Construction at the Naval Magazine Indian Island Ammunition
Wharf, Puget Sound, Washington
Sec.
217.80 Specified activity and geographical region.
217.81 Effective dates.
217.82 Permissible methods of taking.
217.83 Prohibitions.
217.84 Mitigation requirements.
217.85 Requirements for monitoring and reporting.
217.86 Letters of Authorization.
217.87 Renewals and modifications of Letters of Authorization.
217.88-217.289 [Reserved]
Sec. 217.80 Specified activity and geographical region.
(a) Regulations in this subpart apply only to the U.S. Navy (Navy)
and those persons it authorizes or funds to conduct activities on its
behalf for the taking of marine mammals that occur in the areas
outlined in paragraph (b) of this section and that occur incidental to
construction activities, including maintenance and replacement of
piles, at the Naval Magazine Indian Island Ammunition Wharf, Puget
Sound, Washington.
(b) The taking of marine mammals by the Navy may be authorized in a
Letter
[[Page 74139]]
of Authorization (LOA) only if it occurs at the Naval Magazine Indian
Island Ammunition Wharf, Puget Sound, Washington.
Sec. 217.81 Effective dates.
Regulations in this subpart are effective from October 1, 2024,
until September 30, 2029.
Sec. 217.82 Permissible methods of taking.
Under an LOA issued pursuant to Sec. 216.106 of this chapter and
Sec. 217.86, the Holder of the LOA (hereinafter ``Navy'') may
incidentally, but not intentionally, take marine mammals within the
area described in Sec. 217.80(b) by harassment associated with
construction activities, provided the activity is in compliance with
all terms, conditions, and requirements of the regulations in this
subpart and the applicable LOA.
Sec. 217.83 Prohibitions.
(a) Except for the takings contemplated in Sec. 217.82 and
authorized by a LOA issued under Sec. 216.106 of this chapter and
Sec. 217.86, it is unlawful for any person to do any of the following
in connection with the activities described in Sec. 217.80:
(1) Violate, or fail to comply with, the terms, conditions, and
requirements of this subpart or a LOA issued under Sec. 216.106 of
this chapter and Sec. 217.86;
(2) Take any marine mammal not specified in such LOA;
(3) Take any marine mammal specified in such LOA in any manner
other than as specified;
(4) Take a marine mammal specified in such LOA if NMFS determines
such taking results in more than a negligible impact on the species or
stocks of such marine mammal; or
(5) Take a marine mammal specified in such LOA after NMFS
determines such taking results in an unmitigable adverse impact on the
species or stock of such marine mammal for taking for subsistence uses.
(b) [Reserved]
Sec. 217.84 Mitigation requirements.
(a) When conducting the activities identified in Sec. 217.80(a),
the mitigation measures contained in any LOA issued under Sec. Sec.
216.106 of this chapter and 217.86 must be implemented. These
mitigation measures include but are not limited to:
(1) A copy of any issued LOA must be in the possession of the Navy,
its designees, and work crew personnel operating under the authority of
the issued LOA.
(2) The Navy must follow mitigation procedures as described in
Sec. 217.84. Protected Species Observers (PSOs) must monitor the
designated harassment zones to the maximum extent possible based on
daily visibility conditions.
(3) The Navy must ensure that construction supervisors and crews,
the PSO team, and relevant Navy staff are trained prior to the start of
construction activity subject to this rule, so that responsibilities,
communication procedures, monitoring protocols, and operational
procedures are clearly understood. New personnel joining during the
project must be trained prior to commencing work.
(4) The Navy must avoid direct physical interaction with marine
mammals during construction activity. If a marine mammal comes within
10 m of such activity, operations must cease and vessels must reduce
speed to the minimum level required to maintain steerage and safe
working conditions, as necessary, to avoid direct physical interaction.
(5) For all pile driving activity, the Navy must implement shutdown
zones with radial distances as identified in a LOA issued under Sec.
216.106 of this chapter and Sec. 217.86. If a marine mammal comes
within or approaches the shutdown zone, pile driving activity must
cease.
(6) The Navy must shut down in-water activities when cetaceans are
observed approaching or within any harassment zone.
(7) The Navy must use soft start techniques when impact pile
driving. Soft start requires contractors to provide an initial set of
three strikes from the hammer at reduced energy, followed by a 30-
second waiting period. Then two subsequent reduced-energy strike sets
would occur. A soft start must 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.
(8) The Navy must deploy PSOs as indicated in its Marine Mammal
Monitoring Plan that has been approved by NMFS.
(9) The Navy must employ bubble curtain systems during impact
driving of 36-inch steel piles except under conditions where the water
depth is less than 0.67 meters (2 feet) in depth. Bubble curtains must
meet the following requirements:
(i) The bubble curtain must distribute air bubbles around 100
percent of the piling perimeter for the full depth of the water column.
(ii) The lowest bubble ring must be in contact with the mudline
and/or rock bottom for the full circumference of the ring, and the
weights attached to the bottom ring shall ensure 100 percent mudline
and/or rock bottom contact. No parts of the ring or other objects shall
prevent full mudline and/or rock bottom contact.
(iii) The bubble curtain must be operated such that there is equal
balancing of air flow to all bubblers.
(10) For all pile driving activities, land-based PSOs must be
stationed at the best vantage points practicable to monitor for marine
mammals and implement shutdown/delay procedures. At least one vessel-
based PSO must be employed when practicable. Additional PSOs must be
added if warranted by site conditions and/or the level of marine mammal
activity in the area.
(11) Monitoring must take place from 30 minutes prior to initiation
of pile driving activity (i.e., pre-start clearance monitoring) through
30 minutes post-completion of pile driving activity. Pre-activity
monitoring must be conducted for 30 minutes to ensure that the shutdown
zone is clear of marine mammals, and pile driving may commence when
PSOs have declared the shutdown zone clear of marine mammals. In the
event of a delay or shutdown of activity resulting from marine mammals
in the shutdown zone, animals must be allowed to remain in the shutdown
zone (i.e., must leave of their own volition) and their behavior must
be monitored and documented. 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. Monitoring must occur
throughout the time required to drive a pile. If work ceases for more
than 30 minutes, the pre-activity monitoring of the shutdown zones must
commence. A determination that the shutdown zone is clear must be made
during a period of good visibility.
(12) If a marine mammal approaches or enters the shutdown zone, all
pile driving activities at that location must be halted. If pile
driving is halted or delayed due to the presence of a marine mammal,
the activity may not commence or resume until either the animal has
voluntarily left and been visually confirmed beyond the shutdown zone
or 15 minutes have passed without re-detection of the animal.
(13) Pile driving activity must be halted upon observation of a
species entering or within the harassment zone for either a species for
which incidental take is not authorized or a species for which
incidental take has been authorized but the authorized number of takes
has been met.
[[Page 74140]]
(14) Trained PSOs must be placed at 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.
(15) Monitoring must be conducted by qualified, NMFS-approved PSOs,
in accordance with the following conditions:
(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 are required, a lead PSO or
monitoring coordinator must be designated. The lead PSO 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 these regulations.
(b) [Reserved]
Sec. 217.85 Requirements for monitoring and reporting.
(a) The Navy must submit a Marine Mammal Monitoring Plan to NMFS
for approval at least 90 days before the start of construction and
abide by the Plan if approved.
(b) The Navy must deploy PSOs as indicated in its approved Marine
Mammal Monitoring Plan.
(c) PSOs must be trained in marine mammal identification and
behaviors. PSOs must have no other construction-related tasks while
conducting monitoring.
(d) The Navy must monitor the Level B harassment zones (areas where
SPLs are equal to or exceed the 160 dB root-mean-squared (rms)
threshold for impact driving and the 120 dB rms threshold during
vibratory pile driving) to the maximum extent practicable and the
shutdown zones.
(e) The Navy must coordinate with the Center for Whale Research,
Orca network, and NMFS to avoid noise exposure of southern resident
killer whales. The Navy must shut down in-water activities when
southern resident killer whales are observed or reported within or
approaching any harassment zone.
(f) The Navy must submit a draft monitoring report to NMFS within
90 calendar days of the completion of each construction year. A draft
comprehensive 5-year summary report must also be submitted to NMFS
within 90 days of the end of the project. The reports must detail the
monitoring protocol and summarize the data recorded during monitoring.
Final annual reports and the final comprehensive report must be
prepared and submitted within 30 days following resolution of any NMFS
comments on the draft report. If no comments are received from NMFS
within 30 days of receipt of the draft report, the report must be
considered final. If comments are received, a final report addressing
NMFS comments must be submitted within 30 days after receipt of
comments. The reports must contain the informational elements described
at minimum below including:
(1) Dates and times (begin and end) of all marine mammal
monitoring;
(2) Construction activities occurring during each daily observation
period, including how many and what type of piles were driven or
removed, by what method (i.e., impact or vibratory), the total duration
of driving time for each pile (vibratory driving), and number of
strikes for each pile (impact driving);
(3) Environmental conditions during monitoring periods (at
beginning and end of PSO shift and whenever conditions change
significantly), 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 (if less
than the harassment zone distance);
(4) Upon observation of a marine mammal, the following information
should be collected:
(i) PSO who sighted the animal, observer location, and activity at
time of sighting:
(ii) Time of sighting;
(iii) Identification of the animal (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;
(iv) Distances and bearings of each marine mammal observed in
relation to the pile being driven for each sighting (if pile driving
was occurring at time of sighting);
(v) Estimated number of animals (min/max/best);
(vi) Estimated number of animals by cohort (adults, juveniles,
neonates, group composition, etc.);
(vii) Animal's closest point of approach and estimated time spent
within the harassment zone;
(viii) Description of any marine mammal behavioral observations
(e.g., observed behaviors such as feeding or traveling), including an
assessment of behavioral responses to the activity (e.g., no response
or changes in behavioral state such as ceasing feeding, changing
direction, flushing, or breaching);
(ix) Detailed information about any implementation of any
mitigation (e.g., shutdowns and delays), a description of specific
actions that ensued, and resulting changes in the behavior of the
animal, if any; and
(x) All PSO datasheets and/or raw sightings data.
(g) In the event that personnel involved in the construction
activities discover an injured or dead marine mammal, the Navy must
report the incident to NMFS Office of Protected Resources (OPR), and to
the West Coast Regional Stranding Coordinator, as soon as feasible. If
the death or injury was caused by the specified activity, the Navy must
immediately cease the specified activities until NMFS OPR is able to
review the circumstances of the incident and determine what, if any,
additional measures are appropriate to ensure compliance with the terms
of this rule and the LOA issued under Sec. 216.106 of this chapter and
Sec. 217.86. The Navy must not resume their activities until notified
by NMFS. The report must include the following information:
(1) Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
(2) Species identification (if known) or description of the
animal(s) involved;
(3) Condition of the animal(s) (including carcass condition if the
animal is dead);
(4) Observed behaviors of the animal(s), if alive;
(5) If available, photographs or video footage of the animal(s);
and
(6) General circumstances under which the animal was discovered.
Sec. 217.86 Letters of Authorization.
(a) To incidentally take marine mammals pursuant to these
regulations, the Navy must apply for and obtain an LOA.
(b) An LOA, unless suspended or revoked, may be effective for a
period of time not to exceed the expiration date of these regulations.
(c) If an LOA expires prior to the expiration date of these
regulations, the
[[Page 74141]]
Navy may apply for and obtain a renewal of the LOA.
(d) In the event of projected changes to the activity or to
mitigation and monitoring measures required by an LOA, the Navy must
apply for and obtain a modification of the LOA as described in Sec.
217.87.
(e) The LOA must set forth the following information:
(1) Permissible methods of incidental taking;
(2) Means of effecting the least practicable adverse impact (i.e.,
mitigation) on the species, its habitat, and on the availability of the
species for subsistence uses; and
(3) Requirements for monitoring and reporting.
(f) Issuance of the LOA must be based on a determination that the
level of taking will be consistent with the findings made for the total
taking allowable under these regulations.
(g) Notice of issuance or denial of an LOA must be published in the
Federal Register within 30 days of a determination.
Sec. 217.87 Renewals and modifications of Letters of Authorization.
(a) An LOA issued under Sec. Sec. 216.106 of this chapter and
217.86 for the activity identified in Sec. 217.80(a) may be renewed or
modified upon request by the applicant, provided that:
(1) The proposed specified activity and mitigation, monitoring, and
reporting measures, as well as the anticipated impacts, are the same as
those described and analyzed for these regulations; and
(2) NMFS determines that the mitigation, monitoring, and reporting
measures required by the previous LOA under these regulations were
implemented.
(b) For LOA modification or renewal requests by the applicant that
include changes to the activity or the mitigation, monitoring, or
reporting that do not change the findings made for the regulations or
result in no more than a minor change in the total estimated number of
takes (or distribution by species or years), NMFS may publish a notice
of proposed LOA in the Federal Register, including the associated
analysis of the change, and solicit public comment before issuing the
LOA.
(c) An LOA issued under Sec. 216.106 of this chapter and Sec.
217.86 for the activity identified in Sec. 217.80(a) may be modified
by NMFS under the following circumstances:
(1) NMFS may modify (including augment) the existing mitigation,
monitoring, or reporting measures (after consulting with Navy regarding
the practicability of the modifications) if doing so creates a
reasonable likelihood of more effectively accomplishing the goals of
the mitigation and monitoring set forth in the preamble for these
regulations;
(i) Possible sources of data that could contribute to the decision
to modify the mitigation, monitoring, or reporting measures in an LOA:
(A) Results from Navy's monitoring from previous years;
(B) Results from other marine mammal and/or sound research or
studies; and
(C) Any information that reveals marine mammals may have been taken
in a manner, extent or number not authorized by these regulations or
subsequent LOAs; and
(ii) If, through adaptive management, the modifications to the
mitigation, monitoring, or reporting measures are substantial, NMFS
must publish a notice of proposed LOA in the Federal Register and
solicit public comment;
(2) If NMFS determines that an emergency exists that poses a
significant risk to the well-being of the species or stocks of marine
mammals specified in a LOA issued pursuant to Sec. 216.106 of this
chapter and Sec. 217.86, a LOA may be modified without prior notice or
opportunity for public comment. Notification would be published in the
Federal Register within 30 days of the action.
Sec. Sec. 217.88-217.89 [Reserved]
[FR Doc. 2023-23737 Filed 10-27-23; 8:45 am]
BILLING CODE 3510-22-P