[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:
    <bullet> 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:
    <bullet> monitoring of the construction areas to detect the 
presence of marine mammals before beginning construction activities;
    <bullet> Shutdown of construction activities under certain 
circumstances to avoid injury of marine mammals;
    <bullet> 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
    <bullet> 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
------------------------------------------------------------------------
     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).
------------------------------------------------------------------------

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:
    <bullet> 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.
    <bullet> 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
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         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\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 Order Artiodactyla--Cetacea--Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
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.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                  Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
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.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
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).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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 (SEL<INF>cum</INF>) in an accelerating fashion: At 
low exposures with lower SEL<INF>cum</INF>, the amount of TTS is 
typically small and the growth curves have shallow slopes. At exposures 
with higher SEL<INF>cum</INF>, 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:
    <bullet> Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
    <bullet> Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the activity; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
    <bullet> Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
    <bullet> How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
    <bullet> Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and,
    <bullet> Mitigation and monitoring effectiveness.
    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
    <bullet> 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.
    <bullet> 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.
    <bullet> 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.
    <bullet> 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.
    <bullet> 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:
    <bullet> 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.
    <bullet> Advanced education in biological science, wildlife 
management, mammalogy or related field (Bachelor's degree or higher is 
preferred).
    <bullet> Experience and ability to conduct field observations and 
collect data according to assigned protocols (this may include academic 
experience).
    <bullet> Experience or training in the field identification of 
marine mammals (cetaceans and pinnipeds).
    <bullet> Sufficient training, orientation or experience with vessel 
operation and pile driving operations to provide for personal safety 
during observations.
    <bullet> 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.
    <bullet> Ability to communicate orally, by radio or in person, with 
project personnel to provide real time information on marine mammals 
observed in the area 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:
    <bullet> Dates and times (begin and end) of all marine mammal 
monitoring;
    <bullet> 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);
    <bullet> PSO locations during marine mammal monitoring; and
    <bullet> Environmental conditions during monitoring periods (at 
beginning and end of PSO shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance.
    In addition, for each observation of a marine mammal, the marine 
mammal report would include the following information:
    <bullet> Name of PSO who sighted the animal(s) and PSO location and 
activity at time of sighting;
    <bullet> Time of sighting;
    <bullet> 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;
    <bullet> Distance and location of each observed marine mammal 
relative to the pile being driven for each sighting;
    <bullet> Estimated number of animals (min/max/best estimate);
    <bullet> Estimated number of animals by cohort (adults, juveniles, 
neonates, group composition, etc.);
    <bullet> Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as feeding or traveling), including an 
assessment of behavioral responses thought to have resulted from the 
activity (e.g., no response or changes in behavioral state such as 
ceasing feeding, changing direction, flushing, or breaching);
    <bullet> Number of marine mammals detected within the harassment 
zones, by species; and
    <bullet> 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) 
(<a href="/cdn-cgi/l/email-protection#87d7d5a9ced3d7a9cae8e9eef3e8f5eee9e0d5e2f7e8f5f3f4c7e9e8e6e6a9e0e8f1"><span class="__cf_email__" data-cfemail="1f4f4d31564b4f31527071766b706d7671784d7a6f706d6b6c5f71707e7e31787069">[email protected]</span></a>), 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:
    <bullet> No mortality is anticipated or authorized;
    <bullet> No Level A harassment is anticipated or authorized with 
the exception of limited take of harbor seals;
    <bullet> Anticipated incidents of Level B harassment consist of, at 
worst, temporary modifications in behavior;
    <bullet> The required mitigation measures (i.e., shutdown zones) 
are expected to be effective in reducing the effects of the specified 
activity;
    <bullet> Minimal impacts to marine mammal habitat/prey are 
expected; and
    <bullet> 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


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