Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to San Francisco Bay Area Water Emergency Transportation Authority's Ferry Terminal Refurbishment in Alameda, California, 42304-42322 [2023-13899]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 88, Number 125 (Friday, June 30, 2023)]
[Notices]
[Pages 42304-42322]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-13899]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XD066]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to San Francisco Bay Area Water 
Emergency Transportation Authority's Ferry Terminal Refurbishment in 
Alameda, California

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; proposed incidental harassment authorization; request 
for comments on proposed authorization and possible renewal.

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SUMMARY: NMFS has received a request from the San Francisco Bay Area 
Water Emergency Transportation Authority (WETA) for authorization to 
take marine mammals incidental to the refurbishment of the Alameda Main 
Street Ferry Terminal in Alameda, California. Pursuant to the Marine 
Mammal Protection Act (MMPA), NMFS is requesting comments on its 
proposal to issue an incidental harassment authorization (IHA) to 
incidentally take marine mammals during the specified activities. NMFS 
is also requesting comments on a possible one-time, one-year renewal 
that could be issued under certain circumstances and if all 
requirements are met, as described in Request for Public Comments at 
the end of this notice. NMFS will consider public comments prior to 
making any final decision on the issuance of the requested MMPA 
authorization and agency responses will be summarized in the final 
notice of our decision.

DATES: Comments and information must be received no later than July 31, 
2023.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service and should be submitted via email to 
[email protected].
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments, including all attachments, must 
not exceed a 25-megabyte file size. All comments received are a part of 
the public record and will generally be posted online at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities without change. All 
personal identifying information (e.g., name, address) voluntarily 
submitted by the commenter may be publicly accessible. Do not submit 
confidential business information or otherwise sensitive or protected 
information.

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

SUPPLEMENTARY INFORMATION: 

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are proposed or, if the taking is limited to harassment, a notice of a 
proposed IHA is provided to the public for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of the species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring, and reporting of the takings are set forth. The definitions 
of all applicable MMPA statutory terms cited above are included in the 
relevant sections below.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an IHA) 
with respect to potential impacts on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for NOAA Administrative Order 216-
6A, which do not individually or cumulatively have the potential for 
significant impacts on the quality of the human environment and for 
which we have not identified any extraordinary circumstances that would 
preclude this categorical exclusion. Accordingly, NMFS has 
preliminarily determined that the issuance of the proposed IHA 
qualifies to be categorically excluded from further NEPA review.
    We will review all comments submitted in response to this notice 
prior to concluding our NEPA process or making a final decision on the 
IHA request.

Summary of Request

    On February 9, 2023, NMFS received a request from WETA for an IHA 
to take marine mammals incidental to pile removal and driving 
associated with refurbishment of the Alameda Main Street Ferry Terminal 
in Alameda, California. Following NMFS' review of the application, WETA 
submitted revised versions on March 15, April 18, May 18, and May 24, 
2023. The application was deemed adequate and complete on May 25, 2023. 
WETA's request is for take of harbor seals (Phoca vitulina) and 
California sea lions (Zalophus californianus) by Level A harassment and 
Level B harassment. Neither WETA nor NMFS expect serious injury or 
mortality to result from this activity and, therefore, an IHA is 
appropriate.

[[Page 42305]]

Description of Proposed Activity

Overview

    WETA proposes to refurbish the Alameda Main Street Ferry Terminal 
in the Oakland Inner Harbor, Alameda, California, to update and replace 
ageing ferry terminal components and structural support. Water depth 
within the project area varies between 14-28 inches (in; 35.56-71.12 
centimeter (cm)) mean lower low water (MLLW), and most construction 
activities will occur above or at the waterline. The only elements that 
would extend below the mudline are nine new steel piles that would have 
a maximum tip elevation of approximately 110 in MLLW. WETA intends to 
use vibratory extraction to remove four existing 30 in (76.2 cm) steel 
guide piles and vibratory installation to drive nine new steel piles: 
two 24 in (60.9 cm) steel pipe piles with concrete cap beams on land, 
one 48 in (121.9 cm) steel pipe monopile in water, four 36 in (91.4 cm) 
steel guide piles in water, and two 36 in (91.4 cm) donut fender piles 
in water. A maximum of 6 days of consecutive piling activities is 
proposed to occur during the course of construction (4-6 weeks) from 
August through November 2023. WETA proposes to use vibratory pile 
driving and, if necessary, impact pile driving to achieve required tip 
elevation for the nine new piles. No in-air impacts to marine mammals 
are anticipated from the installation of the two 24 in (60.9 cm) piles 
driven on land, as such, they were not included in the Estimated Take 
section and will not be discussed further.
    Project construction would include replacement of the existing 
bridge walkway and foundation, replacement of the gangway, demolition 
and replacement of the float, removal and installation of guide piles, 
and upgrades to utilities at the project site. No take of marine 
mammals is anticipated to occur incidental to these portions of the 
project and these activities will not be discussed further.

Dates and Duration

    This IHA would be effective from August 15, 2023, until August 14, 
2024. Pile extraction and installation activities would occur for a 
total of 6 consecutive days (5 days in water, 1 day on land) from 
August through November 2023. WETA plans to conduct piling activities 
during daylight hours, with noise-generating construction activities 
limited to occur between the hours of 0700-1900 Monday through Friday, 
and 0800-1300 Saturdays. Due to in[hyphen]water work timing 
restrictions to protect ESA-listed fish species, all in[hyphen]water 
construction activities including pile extraction and installation 
would occur during the period from June 1 to November 30. Pile 
extraction is anticipated to take between 1-3 days, pile installation 
is anticipated to take 3 days, of which 2 days will be required for in-
water pile installation.

Specific Geographic Region

    This project will be located at the existing Alameda Main Street 
Ferry Terminal in Alameda, CA (Figure 1), at a water depth between 14-
28 in (35.56-71.12 cm). All project activities for which take is being 
requested will be located in the Oakland Inner Harbor, Alameda (see 
Figure 2 in IHA application).
BILLING CODE 3510-22-P

[[Page 42306]]

[GRAPHIC] [TIFF OMITTED] TN30JN23.048

BILLING CODE 3510-22-C

Detailed Description of the Specified Activity

    Vibratory extraction of four existing 30 in diameter steel guide 
piles would occur over 1 to 3 days. Vibratory installation of one 48 in 
diameter steel pipe monopile, four 36 in diameter steel guide piles, 
and two 36 in diameter donut fender piles would occur over 2 days, with 
the monopile requiring 1 day and the six 36 in piles requiring 1 day. 
Impact installation of the seven new piles would occur only if required 
tip elevation was not achieved through vibratory methods and a bubble 
curtain would be employed to attenuate noise from impact driving 
(assuming a 5-dB reduction).

[[Page 42307]]



                                                  Table 1--Pile Extraction and Installation Activities
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                                                                                                                    Duration of
                                                                                                                     vibratory      Estimated blows of
          Pile activity                  Structure          Pile size     Piles per day   Duration of  activity    activity per     impact driving per
                                                              (in)                                                     pile          pile  (strikes) *
                                                                                                                     (minutes)
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Extraction.......................  Removal of existing               30               4  1-3 days...............              45  N/A
                                    guide piles.
Installation.....................  Terminal bridge and               48               1  1 day..................              45  1,015
                                    foundation
                                    replacement.
Installation.....................  Float replacement                 36               6  1 day..................              45  1,015
                                    (guide piles and
                                    donut fender piles).
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Note: Impact pile installation will only be used if vibratory methods are insufficient to achieve required tip elevation.
* Impact pile driving assumes approx. 20-30 minutes of driving.

    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions, instead of reprinting the information. Additional 
information regarding population trends and threats may be found in 
NMFS' Stock Assessment Reports (SARs; 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 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 anticipated or proposed to be authorized 
here, PBR and annual serious injury and mortality from anthropogenic 
sources are included here as gross indicators of the status of the 
species or stocks and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS' U.S. Pacific SARs. All values presented in Table 2 are the most 
recent available at the time of publication (including from the draft 
2022 SARs) and are available online at: www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

                                     Table 2--Marine Mammal Species Likely Impacted by the Specified Activities \1\
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                                                                                      ESA/MMPA status;   Stock abundance  (CV,
            Common name                  Scientific name              Stock           strategic (Y/N)      Nmin, most recent        PBR      Annual M/SI
                                                                                            \2\          abundance survey) \3\                   \4\
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                                                               Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and
 sea lions):
    California sea lion............  Zalophus californianus  U.S...................  -/-; N             257,606 (N/A; 233,515;       14,011         >321
                                                                                                         2014).
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Family Phocidae (earless seals):
    Harbor seal....................  Phoca vitulina          California............  -/-; N             30,968 (0.157; 27,348;        1,641         42.8
                                      richardii.                                                         2012).
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\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
  (https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/; Committee on Taxonomy (2022)).
\2\ 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.
\3\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, vessel strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range.

    As indicated above, both species in Table 2 temporally and 
spatially co-occur with the activity to the degree that take is 
reasonably likely to occur and are also included in Table 2 of the IHA 
application. No other marine mammal species are expected to occur in 
the project area.

California Sea Lion

    California sea lions occur from Vancouver Island, British Columbia, 
to the southern tip of Baja California,

[[Page 42308]]

Mexico. Sea lions breed on the offshore islands of southern and central 
California from May through July (Heath and Perrin, 2009). During the 
non-breeding season, adult and sub-adult males and juveniles migrate 
northward along the coast to central and northern California, Oregon, 
Washington, and Vancouver Island (Jefferson et al., 1993). They return 
south the following spring (Heath and Perrin, 2009, Lowry and Forney, 
2005). Females and some juveniles tend to remain closer to rookeries 
(Antonelis et al., 1990, Melin et al., 2008).
    Pupping occurs primarily on the California Channel Islands from 
late May until the end of June (Peterson and Bartholomew, 1967). No 
pupping has been recorded in the San Francisco Bay. Weaning and mating 
occur in late spring and summer during the peak upwelling period 
(Bograd et al., 2009). After the mating season, adult males migrate 
northward to feeding areas as far away as the Gulf of Alaska (Lowry et 
al., 1992), and they remain away until spring (March through May), when 
they migrate back to the breeding colonies. Adult females generally 
remain south of Monterey Bay, California, throughout the year, feeding 
in coastal waters in the summer and offshore waters in the winter, 
alternating between foraging and nursing their pups on shore until the 
next pupping/breeding season (Melin and DeLong, 2000, Melin et al., 
2008).
    California sea lions experienced an Unusual Mortality Event (UME), 
not correlated to an El Ni[ntilde]o event, from 2013-2017 (Carretta et 
al., 2022). Pup and juvenile age classes experienced high mortality 
during this time, likely attributed to sea lion prey availability, 
specifically Pacific sardines (Sardinops sagax). California sea lions 
are also susceptible to the algal neurotoxin domoic acid (Carretta et 
al., 2022). This neurotoxin is expected to cause future mortalities 
among California sea lions due to the prevalence of harmful algal 
blooms within their habitat.
    In San Francisco Bay, sea lions haul out primarily on floating 
docks at Pier 39 at the Fisherman's Wharf area of the San Francisco 
Marina, approximately 10.5 kilometers (6.5 miles) west-northwest of the 
project area. Haul out numbers at Pier 39 vary seasonally. In addition 
to the Pier 39 haul out, California sea lions haul out on buoys, 
wharfs, and similar structures throughout the Bay.

Harbor Seal

    Harbor seals are distributed from Baja California, Mexico, to the 
eastern Aleutian Islands of Alaska (Harvey and Goley, 2011). Harbor 
seals do not make extensive pelagic migrations but may travel hundreds 
of kilometers to find food or suitable breeding areas (Harvey and 
Goley, 2011, Carretta et al., 2022). Seals primarily haul out on remote 
mainland and island beaches, reefs, and estuary areas. At haulout 
sites, they congregate to rest, socialize, breed, and molt. In 
California, there are approximately 500 haulout sites along the 
mainland and on offshore islands, including intertidal sandbars, rocky 
shores, and beaches (Hanan, 1996, Lowry et al., 2008).
    Harbor seals are opportunistic, generalist foragers and are 
expected to forage in shallow, intertidal waters on a variety of fish, 
crustaceans, and other species in the San Francisco Bay and could 
occasionally be found foraging in the Oakland Inner Harbor (Gibble, 
2011). Harbor seals haul out at approximately 20 locations in San 
Francisco Bay with three main locations: Mowry Slough in the south, 
Corte Madera Marsh and Castro Rocks in the north, and Yerba Buena 
Island in the central bay (Gibble, 2011, Grigg et al., 2012).
    Harbor seals are the most common marine mammal species observed in 
the San Francisco Bay, where they primarily haul out on exposed rocky 
ledges and on sloughs in the southern San Francisco Bay. Harbor seals 
are central-place foragers (Orians, 1979) and tend to exhibit strong 
site fidelity within season and across years, generally forage close to 
haulout sites, and repeatedly visit specific foraging areas (Grigg et 
al., 2012, Suryan and Harvey, 1998, Thompson et al., 1998). Harbor 
seals in San Francisco Bay forage mainly within 7 mi (10 km) of their 
primary haulout site (Grigg et al., 2012), and often within just 1-3 mi 
(1-5 km; Torok, 1994). Depth, bottom relief, and prey abundance also 
influence foraging location (Grigg et al., 2012).
    Peak numbers of harbor seals haul out in central California during 
late May to early June, which coincides with the peak molt (May through 
June). During both pupping and molting seasons, the number of seals and 
the length of time hauled out per day increase, from an average of 7 
hours per day to 10-12 hours per day (Harvey and Goley, 2011, Huber et 
al., 2001, Stewart and Yochem, 1994). Pupping occurs from March through 
May in central California and pups are weaned in approximately 4 weeks, 
most by mid-June (Codde and Allen, 2018). The closest recognized harbor 
seal pupping site to the proposed project area is at Castro Rocks, 
approximately 12 mi (19 km) away.
    Harbor seals tend to forage at night and haul out during the day 
with a peak in the afternoon between 1300 and 1600 hr (Grigg et al., 
2012, London et al., 2002, Stewart and Yochem, 1994, Yochem et al., 
1987). Tide levels affect the maximum number of seals hauled out, with 
the largest number of seals hauled out at low tide, but time of day and 
season have the greatest influence on haul out behavior (Manugian et 
al., 2017, Patterson and Acevedo-Guti[eacute]rrez, 2008, Stewart and 
Yochem, 1994).

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.

[[Page 42309]]



                  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 (dolphins,      150 Hz to 160 kHz.
 toothed whales, beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans (true          275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 Cephalorhynchid, Lagenorhynchus cruciger &
 L. australis).
Phocid pinnipeds (PW) (underwater) (true     50 Hz to 86 kHz.
 seals).
Otariid pinnipeds (OW) (underwater) (sea     60 Hz to 39 kHz.
 lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006, Kastelein et al., 2009, Reichmuth et al., 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section provides a discussion of the ways in which components 
of the specified activity may impact marine mammals and their habitat. 
The Estimated Take of Marine Mammals section later in this document 
includes a quantitative analysis of the number of individuals that are 
expected to be taken by this activity. The Negligible Impact Analysis 
and Determination section considers the content of this section, the 
Estimated Take of Marine Mammals section, and the Proposed Mitigation 
section, to draw conclusions regarding the likely impacts of these 
activities on the reproductive success or survivorship 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 pile driving and 
removal. The effects of underwater noise from WETA's proposed 
activities have the potential to result in Level A and Level B 
harassment of marine mammals in the project area.

Description of Sound Sources

    The marine soundscape is comprised of both ambient and 
anthropogenic sounds. Ambient sound is defined as the all-encompassing 
sound in a given place and is usually a composite of sound from many 
sources both near and far (American National Standards Institute, 
1995). The sound level of an area is defined by the total acoustical 
energy being generated by known and unknown sources. These sources may 
include physical (e.g., waves, wind, precipitation, earthquakes, ice, 
atmospheric sound), biological (e.g., sounds produced by marine 
mammals, fish, and invertebrates), and anthropogenic sound (e.g., 
vessels, dredging, aircraft, construction).
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from the 
specified 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 proposed 
project would include vibratory pile extraction and vibratory pile 
installation, with the potential for impact pile installation. The 
sounds produced by these activities fall into one of two general sound 
types: impulsive and non-impulsive. Impulsive sounds (e.g., explosions, 
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 (American National Standards Institute, 
1986, 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 (American National Standards 
Institute, 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).
    Two types of hammers would be used on this project, vibratory and, 
if necessary, impact. 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) 10-20 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). 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.
    The likely or possible impacts of WETA'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 close enough to be 
harassed due to the presence of equipment or personnel would be

[[Page 42310]]

within the Level B harassment zones from pile removal or 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 driving activities (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 WETA'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 (TS) and behavioral reactions 
(e.g., avoidance, temporary cessation of foraging and vocalizing, 
changes in dive behavior). Exposure to anthropogenic noise can also 
lead to non-observable physiological responses, such 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 construction 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.
    NMFS defines a noise-induced TS as a change, usually an increase, 
in the threshold of audibility at a specified frequency or portion of 
an individual's hearing range above a previously established reference 
level (NMFS, 2018). The amount of TS is customarily expressed in dB and 
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) (Kastelein et al., 
2014b), 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, Ward et al., 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)--TTS is 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 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, Finneran et al., 2002). As described in Finneran 
(2016), marine mammal studies have shown the amount of TTS increases 
with cumulative sound exposure level (SELcum) in an 
accelerating fashion: At low exposures with lower SELcum, 
the amount of TTS is typically small and the growth curves have shallow 
slopes. At exposures with higher SELcum, the growth curves 
become steeper and approach linear relationships with the noise SEL.
    Depending on the degree (elevation of threshold in dB), duration 
(i.e., recovery time), and frequency range of TTS, and the context in 
which it is experienced, TTS can have effects on marine mammals ranging 
from discountable to serious (similar to those discussed in auditory 
masking, below). For example, a marine mammal may be able to readily 
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal 
is traveling through the open ocean, where ambient noise is lower and 
there are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during time when 
communication is critical for successful mother/calf interactions could 
have more serious impacts. We note that reduced hearing sensitivity as 
a simple function of aging has been observed in marine mammals, as well 
as humans and other taxa (Southall et al., 2007), so we can infer that 
strategies exist for coping with this condition to some degree, though 
likely not without cost.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus 
leucas), harbor porpoise (Phocoena phocoena), Yangtze finless porpoise 
(Neophocoena asiaeorientalis)), and five species of pinnipeds exposed 
to a limited number of sound sources (i.e., tones and octave-band 
noise) in laboratory settings (Finneran, 2015). TTS was not observed in 
trained spotted seals (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). At low frequencies, onset-TTS 
exposure levels are higher compared to those in the region of best 
sensitivity (i.e., a low frequency noise would need to be louder to 
cause TTS onset when TTS exposure level is higher), as shown for harbor 
porpoises and harbor seals (Kastelein et al., 2019b, Kastelein et al., 
2019a, Kastelein et al., 2020a, Kastelein et al., 2020b). In addition, 
TTS can accumulate across multiple exposures, but the resulting TTS 
will be less than the TTS from a single, continuous exposure with the 
same SEL (Mooney et al., 2009, Finneran et al., 2010, Kastelein et al., 
2014a, Kastelein et al., 2015). This means that TTS predictions based 
on the total, cumulative SEL will overestimate the amount of TTS from 
intermittent exposures such as sonars and impulsive sources.
    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 a 15 
minute exposure to 5 dB after a 360 minute exposure; recovery occurred 
within 60 minutes (Kastelein et al., 2016). Additionally, the existing 
marine

[[Page 42311]]

mammal TTS data come from a limited number of individuals within these 
species. No data are available on noise-induced hearing loss for 
mysticetes. Nonetheless, what we considered is the best available 
science. For summaries of data on TTS in marine mammals or for further 
discussion of TTS onset thresholds, please see Southall et al. (2007), 
Southall et al. (2019), Finneran and Jenkins (2012), Finneran (2015), 
and Table 5 in NMFS (2018).
    Proposed activities for this project include impact and vibratory 
pile driving, and vibratory pile removal. There would likely be pauses 
in activities producing the sound 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., NRC, 2005, Lusseau and Bejder, 2007, Weilgart, 2007b).
    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 haul out time, possibly to avoid in-water 
disturbance (Thorson and Reyff, 2006). Behavioral responses to sound 
are highly variable and context-specific and any reactions depend on 
numerous intrinsic and extrinsic factors (e.g., species, state of 
maturity, experience, current activity, reproductive state, auditory 
sensitivity, time of day), as well as the interplay between factors 
(e.g., Richardson et al., 1995, Wartzok et al., 2004, Southall et al., 
2007, Weilgart, 2007a, Archer et al., 2010, Southall et al., 2021). 
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) as well as Nowacek et al. (2007), 
Ellison et al. (2012), and Gomez et al. (2016) 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, 
Melcon et al., 2012). In addition, behavioral state of the animal plays 
a role in the type and severity of a behavioral response, such as 
disruption to foraging (e.g., Sivle et al., 2016, Wensveen et al., 
2017). 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 (Goldbogen et al., 2013).
    Stress responses--An animal's perception of a threat may be 
sufficient to trigger stress responses consisting of some combination 
of behavioral responses, autonomic nervous system responses, 
neuroendocrine responses, or immune responses (e.g., Selye, 1950, 
Moberg, 2000). In many cases, an animal's first and sometimes most 
economical (in terms of energetic costs) response is behavioral 
avoidance of the potential stressor. Autonomic nervous system responses 
to stress typically involve changes in heart rate, blood pressure, and 
gastrointestinal activity. These responses have a relatively short 
duration and may or may not have a significant long-term effect on an 
animal's fitness.
    Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction, altered metabolism, reduced immune 
competence, and behavioral disturbance (e.g., Moberg, 1987, Blecha, 
2000). Increases in the circulation of glucocorticoids are also equated 
with stress (Romano et al., 2004).
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and ``distress'' is the cost of 
the response. During a stress response, an animal uses glycogen stores 
that can be quickly replenished once the stress is alleviated. In such 
circumstances, the cost of the stress response would not pose serious 
fitness consequences. However, when an animal does not have sufficient 
energy reserves to satisfy the energetic costs of a stress response, 
energy resources must be diverted from other functions. This state of 
distress will last until the animal replenishes its energetic reserves 
sufficient to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well-studied through 
controlled experiments for both laboratory and free-ranging animals 
(e.g., Holberton et al., 1996, Hood et al., 1998, Jessop et al., 2003, 
Krausman et al., 2004, Lankford et al., 2005). Stress responses due to 
exposure to anthropogenic sounds or other stressors and their effects 
on marine mammals have also been reviewed (Fair and Becker, 2000, 
Romano et al., 2002b) and, more rarely, studied in wild populations 
(e.g., Romano et al., 2002a). For example, Rolland et al. (2012) found 
that noise reduction from reduced vessel 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

[[Page 42312]]

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 
masking of communication signals by anthropogenic noise may be 
considered as a reduction in the communication space of animals (e.g., 
Clark et al., 2009) and may result in energetic or other costs as 
animals change their vocalization behavior (e.g., Miller et al., 2000, 
Foote et al., 2004, Parks et al., 2007, Di Iorio and Clark, 2010, Holt 
et al., 2009). The Bay is heavily used by commercial, recreational, and 
military vessels, and background sound levels in the area are already 
elevated. Due to the transient nature of marine mammals to move and 
avoid disturbance, masking is not likely to have long-term impacts on 
marine mammal species within the proposed project area.
    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.
    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, there are no known haul out sites in 
the vicinity of the project area and, if there were, 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. 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

    WETA's proposed construction activities could have localized, 
temporary impacts on marine mammal habitat, including prey, by 
increasing in-water SPLs 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 area where both fishes and mammals occur, 
and could affect foraging success. Additionally, marine mammals may 
avoid the area during construction, however, displacement due to noise 
is expected to be temporary and is not expected to result in long-term 
effects to the individuals or populations. Construction activities are 
expected to be 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 
driving is localized to about a 25-ft (7.6-m) radius around the pile 
(Everitt et al., 1980). 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 proposed action is relatively small 
compared to the total available habitat in the Bay. The proposed 
project area is highly influenced by anthropogenic activities and 
provides limited foraging habitat for marine mammals. Furthermore, pile 
driving and removal at the proposed project site would not obstruct 
long-term movements or migration of marine mammals.
    Avoidance by potential prey (i.e., fish) of the immediate area due 
to the temporary loss of this foraging habitat is also possible. The 
duration of fish 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 by 
prey of the disturbed area would still leave significantly large areas 
of potential 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.
    Fish utilize the soundscape and components of sound in their 
environment to perform important functions such as foraging, predator 
avoidance, mating, and spawning (Zelick et al., 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

[[Page 42313]]

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, Popper and Hastings, 2009). Many 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., Pearson et al., 1992, Skalski et 
al., 1992, Santulli et al., 1999, Fewtrell and McCauley, 2012, Paxton 
et al., 2017). In response to pile driving, Pacific sardines and 
northern anchovies (Engraulis mordax) may exhibit an immediate startle 
response to individual strikes, but return to ``normal'' 
pre[hyphen]strike behavior following the conclusion of pile driving 
with no evidence of injury as a result (see NAVFAC, 2014). However, 
some studies have shown no or slight reaction to impulse sounds (e.g., 
Wardle et al., 2001, Popper et al., 2005, Jorgenson and Gyselman, 2009, 
Pe[ntilde]a et al., 2013).
    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. (2012b) 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., 2012a, Casper et al., 2013).
    The greatest potential impact to fish during construction would 
occur during impact pile driving. However, the duration of impact pile 
driving would be limited to a contingency in the event that vibratory 
driving does not satisfactorily install the pile. In-water construction 
activities would only occur during daylight hours allowing fish to 
forage and transit the project area in the evening. Vibratory pile 
driving may elicit behavioral reactions from fish such as temporary 
avoidance of the area but is unlikely to cause injuries to fish or have 
persistent effects on local fish populations. In addition, it should be 
noted that the area in question is low-quality habitat since it is 
already highly developed and experiences a high level of anthropogenic 
noise from normal dock operations and other vessel traffic.
    The most likely impact to fishes from pile driving and removal and 
construction activities at the project area would be temporary 
behavioral avoidance of the area. The duration of fish avoidance of 
this area after pile driving stops is unknown, but a rapid return to 
normal recruitment, distribution, and behavior is anticipated. In 
general, impacts to marine mammal prey species are expected to be minor 
and temporary. Further, it is anticipated that preparation activities 
for pile driving or removal (i.e., positioning of the hammer) and upon 
initial startup of devices would cause fish to move away from the 
affected area outside areas where injuries may occur. Therefore, 
relatively small portions of the proposed project area would be 
affected for short periods of time, and the potential for effects on 
fish to occur would be temporary and limited to the duration of 
sound[hyphen]generating activities.
    In summary, given the short daily duration of sound associated with 
individual pile driving events and the relatively small areas being 
affected, pile driving activities associated with the proposed 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 potential areas 
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 of Marine Mammals

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform both 
NMFS' consideration of ``small numbers,'' and the negligible impact 
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 removal, vibratory driving, 
impact driving) has the potential to result in disruption of behavioral 
patterns for individual marine mammals. There is also some potential 
for PTS (Level A harassment) to result, primarily for phocids because 
predicted auditory injury zones are larger than for otariids. Auditory 
injury is unlikely to occur for otariids. 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.
    Generally speaking, we estimate take by considering: (1) acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
the number of days of activities. We note that while these factors can 
contribute to a basic calculation to provide an initial prediction of 
potential takes, additional information that can qualitatively inform 
take estimates is also sometimes available (e.g., previous monitoring 
results or average group size). Below, we describe the factors 
considered here in more detail and present the proposed take estimates.

[[Page 42314]]

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, Southall et al., 2021, Ellison et 
al., 2012). Based on what the available science indicates and the 
practical need to use a threshold based on a metric that is both 
predictable and measurable for most activities, NMFS typically uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS generally predicts that marine 
mammals are likely to be behaviorally harassed in a manner considered 
to be Level B harassment when exposed to underwater anthropogenic noise 
above root-mean-squared pressure received levels (RMS SPL) of 120 dB 
(referenced to 1 microPascal (re 1 [mu]Pa)) for continuous (e.g., 
vibratory pile driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa 
for non-explosive impulsive (e.g., seismic airguns) or intermittent 
(e.g., scientific sonar) sources. Generally speaking, Level B 
harassment take estimates based on these behavioral harassment 
thresholds are expected to include any likely takes by TTS as, in most 
cases, the likelihood of TTS occurs at distances from the source less 
than those at which behavioral harassment is likely. TTS of a 
sufficient degree can manifest as behavioral harassment, as reduced 
hearing sensitivity and the potential reduced opportunities to detect 
important signals (conspecific communication, predators, prey) may 
result in changes in behavior patterns that would not otherwise occur.
    WETA's proposed activity includes the use of continuous (vibratory 
pile removal and installation) and, potentially, impulsive (impact pile 
installation) 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). WETA's 
proposed activity includes the use of impulsive (impact hammer) and 
non-impulsive (vibratory hammer) sources.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS' 2018 Technical Guidance, which may be accessed at: 
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.
    Pile driving activities, using an impact hammer as well as a 
vibratory hammer, would generate underwater noise that could result in 
disturbance to marine mammals near the project area. A review of 
underwater sound measurements for similar projects was conducted to 
estimate the near-source sound levels for impact and vibratory pile 
driving and vibratory extraction. Source levels for proposed removal 
and installation activities derived from this review are shown in Table 
5.

[[Page 42315]]



                                                          Table 5--Project Sound Source Levels
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Pile size    Peak SPL dB re   RMS SPL dB re    SEL dB re 1
            Driving method                     Location               (in)          1 [mu]Pa        1 [mu]Pa         [mu]Pa               Source
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact *.............................  Water...................              36             206             188             178  Caltrans 2020
Impact *.............................  Water...................              48             208             187             174  Caltrans 2020
Vibratory............................  Water...................           ** 30             200             168             168  POA 2016
Vibratory............................  Water...................              36             200             168             168  POA 2016
Vibratory............................  Water...................              48             200             168             168  POA 2016
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Attenuated condition achieved using a bubble curtain system for all impact pile driving; attenuated condition assumes a 5-dB reduction in sound.
** Vibratory driving of 36 in piles used as proxy for vibratory extraction of 30 in piles.

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

TL = B * Log10 (R1/R2),
where

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

    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, known as practical spreading, 
which is the most appropriate assumption for WETA's proposed activity 
in the absence of specific modeling and site-specific information. If 
piles are installed or removed with a vibratory hammer, the 
SELcum thresholds apply for sounds greater than 150 dB (re 1 
[mu]Pa\2\-sec) SEL and the peak PTS thresholds that apply to marine 
mammals would not be reached (see Appendix A in the IHA application). 
Sound propagation in the Oakland Inner Harbor is limited by bends in 
the Oakland estuary. Substantial sound is not anticipated to travel 
beyond 4,200 m (13,780 ft) to the west (out the shipping channel into 
the bay) and 1,700 m (5,577 ft) east of the project site (where the 
channel bends around the island of Alameda), and will be confined to 
the north and south by the narrow channel of the Oakland Inner Harbor 
(Figure 1). Therefore, the distance for noise impacts would be limited 
to 4,200 m west and 1,700 m east. The Level A shutdown zones and Level 
B harassment zone for WETA's proposed activities are shown in Table 6.

     Table 6--Distance to the Level A and Level B Harassment Thresholds for Proposed Pile-Driving Activities
----------------------------------------------------------------------------------------------------------------
                                                                     Level A         Level A         Level B
            Method                 Pile type        Pile size     threshold for   threshold for  harassment zone
                                                      (in)        phocids  (m)    otariids  (m)         (m)
----------------------------------------------------------------------------------------------------------------
Impact, installation.........  Steel...........              36             827              60  736
Impact, installation.........  Steel...........              48             136              10  631
Vibratory, extraction *......  Steel...........              30              33              10  4,200 W; 1,700
                                                                                                  E
Vibratory, installation *....  Steel...........              36              33              10  4,200 W; 1,700
                                                                                                  E
Vibratory, installation *....  Steel...........              48              10              10  4,200 W; 1,700
                                                                                                  E
----------------------------------------------------------------------------------------------------------------
Note: Vibratory driving of 36 in piles used as proxy for vibratory extraction of 30 in piles.
* Constrained by bends in the Oakland Estuary and relatively shallow bathymetry near the shipping channel: 4,200
  m (13,780 ft) west, 1,700 m (5,577 ft) east.

    Level A Harassment Thresholds--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 (i.e., vibratory and impact piling), the optional 
User Spreadsheet tool predicts the distance at which, if a marine 
mammal remained at that distance for the duration of the activity, it 
would be expected to incur PTS. Inputs used in the optional User 
Spreadsheet tool, and the resulting estimated isopleths, are reported 
in Table 7 The isopleths generated by the User Spreadsheet used the 
same TL coefficients as the Level B harassment zone calculations, as 
indicated above for each activity type. Inputs used in the User 
Spreadsheet (e.g., number of piles per day, duration and/or strikes per 
pile) are presented in Table 1. The maximum RMS SPL, SEL, and peak SPL 
are reported in Table 7. The cumulative SEL and peak SPL were used to 
calculate Level A harassment isopleths for vibratory pile driving and 
extraction activities, while the single strike SEL value was used to 
calculate Level A isopleths for impact pile driving activity.

[[Page 42316]]



                                                               Table 7--Sound Levels Used for Predicting Underwater Sound Impacts
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Pile size    Peak SPL dB re   RMS SPL dB re    SEL dB re 1    Peak SPL  attenuated *   RMS SPL  attenuated *   SEL  attenuated * dB
          Driving method                 Location             (in)          1 [mu]Pa        1 [mu]Pa         [mu]Pa           dB re 1 [mu]Pa          dB re 1 [mu]Pa            re 1 [mu]Pa
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Impact...........................  Water...............              36             211             193             183  206....................  188...................  178
Impact...........................  Water...............              48             213             192             179  208....................  187...................  174
Vibratory........................  Water...............              36             200             168             168  NA.....................  NA....................  NA
Vibratory........................  Water...............              48             200             168             168  NA.....................  NA....................  NA
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Using estimates for vibratory installation of 36 in (91.4 cm) steel pile as proxy for vibratory extraction of 30 in (76.2 cm) steel pile. Sound pressure levels (SPL) measured in dB re 1
  [mu]Pa at 10 meters.
* Attenuated condition assumes minimum 5 dB lower sounds.
NA: sounds from piles driven on land cannot be further attenuated.

Marine Mammal Occurrence

    In this section we provide information about the occurrence of 
marine mammals, including density or other relevant information which 
will inform the take calculations.
    The California Department of Transportation (Caltrans) conducted 
monitoring of marine mammals in the vicinity of the San Francisco-
Oakland Bay Bridge for 16 years. From those data, Caltrans has produced 
at-sea density estimates for California sea lions and harbor seals 
(Caltrans, 2016). Using these density estimates and the estimated Level 
A and Level B harassment areas, take estimates were calculated for all 
potential construction options. Activities and potential animal 
exposure to Level A harassment levels are presented in the IHA 
application's Table 3 for phocid species and Table 4 for otariid 
species. Take estimates based on exposure and activity duration are 
provided in Tables 5 and 6 of the IHA application.
    WETA ferry boat captains have reported frequently seeing both 
California sea lions and harbor seals in the estuary channel and within 
the Oakland Inner Harbor (in-water sightings, not hauled out) but did 
not report seeing either species or other marine mammals near the 
Alameda Main Street Ferry Terminal dock or platform (WETA, pers. 
comm.).
    California sea lion--Caltrans at-sea density estimate for 
California sea lions is 0.161 animals/km\2\ for the summer-late fall 
season (Caltrans, 2016). During El Ni[ntilde]o Southern Oscillation 
(ENSO) conditions, the density of California sea lions in San Francisco 
Bay may be much greater than the value used above. The likelihood of 
ENSO conditions developing in 2023 is probable. To account for the 
potential increase in California sea lions within San Francisco Bay 
during the proposed project, daily take estimated has been increased by 
a factor of 10 for each pile activity and type (e.g., 82 FR 17799, 
April 13, 2017). California sea lions have occupied docks near Pier 39 
in San Francisco, several miles from the project area, since 1987. The 
highest number of sea lions recorded at Pier 39 was 1,701 individuals 
in November 2009. Occurrence of sea lions here is typically lowest in 
June (during pupping and breeding seasons) and highest in August. 
Approximately 85 percent of the animals that haul out at this site are 
males, and no pupping has been observed here or at any other site in 
San Francisco Bay. Pier 39 is the only regularly used haul out site in 
the project vicinity, but sea lions occasionally haul out on human-made 
structures such as bridge piers, jetties, or navigation buoys (Riedman, 
1990).
    Harbor seal--Caltrans at-sea density estimate for harbor seals is 
3.957 animals/km\2\ (Caltrans, 2016). No resident harbor seals occur 
within the Oakland Inner Harbor. The closest haul out to the proposed 
project area is located outside of the Oakland Inner Harbor at Alameda 
Point (approx. 37.770127[deg], -120.296819[deg]), where a float was 
installed by WETA in 2016 to accommodate harbor seals. This haulout can 
carry approximately 80 individuals, with highest sightings occurring 
during winter months. Additionally, the southern shoreline of Yerba 
Buena Island is a haulout site with the highest numbers hauled out 
during afternoon low tides in fall and winter months.

Take Estimation

    Here we describe how the information provided above is synthesized 
to produce a quantitative estimate of the take that is reasonably 
likely to occur and proposed for authorization.
    Incidental take is estimated for each species by estimating the 
maximum number of marine mammals potentially present within a 
harassment zone during active pile driving based on density estimates, 
harassment zone size, and length of construction activity. Animal 
exposure estimates for each species were calculated by multiplying the 
estimated density of each species by the area of each harassment zone 
during active each type of pile driving activity (vibratory removal, 
vibratory driving, impact driving) and pile size (30 in, 36 in, 48 in). 
The estimated density is based on Caltrans (2016) offshore at-sea 
density and increased to account for the likely increase of animals in 
a nearshore environment based on previous comments from the Marine 
Mammal Commission (see Tables 3, 4 in application and 82 FR 17799, 
April 13, 2017).
    Maximum number of animals exposed per activity = Density x Level A 
or Level B harrassment area
    Estimated take was calculated using the exposure estimate 
multiplied by the number of days each in-water pile driving activity 
will occur. An additional take of 0-2 animals per day was added to 
account for the potential occurrence of small groups or additional 
individuals. This was done because small numbers of both species are 
known to incidentally use the Oakland Inner Harbor but extensive 
surveys have not been completed in the proposed project area. Using 
these density estimates and the areas within the Level A and B 
harassment isopleths, the take estimates were calculated for all 
possible construction options and here we show the maximum take 
estimates. Maximum estimated take by Level A harassment is based on 3 
days of in-water vibratory pile removal plus 2 days of in-water impact 
driving, as the Level A harassment isopleth is larger for impact 
driving than vibratory driving (Table 8). Maximum estimated take by 
Level B harassment is based on 3 days of in-water vibratory removal 
plus 2 days of in-water vibratory pile installation, as the Level B 
harassment isopleth for vibratory driving is larger than for impact 
driving (Table 9). This results in a conservative estimate of how many 
marine mammals might be present to ensure that take estimates will not 
be exceeded (Table 10).
    Estimated take = Maximum number of animals exposed x number of days 
per activity + additional individuals

[[Page 42317]]

    Finally, due to the probability of ENSO conditions developing 
throughout 2023 (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml), the daily take 
estimate for California sea lions was multiplied by a factor of 10 for 
each day to account for a potential increase in occurrence that has 
been previously documented for the species under expected 
climatological conditions (see 82 FR 17799, April 13, 2017).

                                               Table 8--Estimated Take by Level A Harassment per Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                           Additional
                                   Pile size                         Potential take/    Duration of       Estimated       level A take    Total level A
      Construction activity           (in)           Species               day        activity  (day)  incidental take     requested           take
                                                                                                                         (animals/day)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory removal...............         * 30  HASE...............  0.04............  1-3              <1               1                1-3
Vibratory removal...............         * 30  CASL...............  NA..............  1-3              NA               NA               NA
Vibratory installation..........           36  HASE...............  0.04............  1                <1               1                1
Vibratory installation..........           36  CASL...............  NA..............  1                NA               NA               NA
Vibratory installation..........           48  HASE...............  0.001...........  1                <1               1                1
Vibratory installation..........           48  CASL...............  NA..............  1                NA               NA               NA
Impact driving..................           36  HASE...............  2.57............  1                3                1                4
Impact driving..................           36  CASL...............  0.002...........  1                <1               1                1
Impact driving..................           48  HASE...............  0.15............  1                <1               1                1
Impact driving..................           48  CASL...............  0.00005.........  1                <1               1                1
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: All California sea lion estimates were multiplied by a factor of 10 to account for the increased occurrence of this species due to potential for
  ENSO conditions.
* Using estimates for vibratory installation of 36 in (91.4 cm) steel pile as proxy for vibratory extraction of 30 in (76.2 cm) steel pile.
HASE: Harbor seal density 3.957 animals/km\2\.
CASL: California sea lion density 0.161 animals/km\2\.


                                               Table 9--Estimated Take by Level B Harassment Per Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                            Additional
                                Pile size                                       Potential     Duration of     Estimated    level B take    Total level B
    Construction activity          (in)         Condition         Species        take/day      activity      incidental      requested         take
                                                                                                 (day)          take       (animals/day)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory removal............         * 30  Unattenuated....  HASE...........         7.64             1-3  8-24                       2           10-30
Vibratory removal............         * 30  Unattenuated....  CASL...........          3.1             1-3  1-3                        2            5-15
Vibratory installation.......           36  Unattenuated....  HASE...........         7.64               1  8                          2              10
Vibratory installation.......           36  Unattenuated....  CASL...........          3.1               1  1                          2               5
Vibratory installation.......           48  Unattenuated....  HASE...........         7.64               1  8                          2              10
Vibratory installation.......           48  Unattenuated....  CASL...........          3.1               1  1                          2               5
Impact driving...............           36  Attenuated......  HASE...........         2.33               1  3                          2               5
Impact driving...............           36  Attenuated......  CASL...........          0.9               1  <1                         2               2
Impact driving...............           48  Attenuated......  HASE...........         1.94               1  2                          2               4
Impact driving...............           48  Attenuated......  CASL...........          0.8               1  <1                         2               2
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: All California sea lion estimates were multiplied by a factor of 10 to account for the increased occurrence of this species due to potential for
  ENSO conditions.
* Using estimates for vibratory installation of 36 in (91.4 cm) steel pile as proxy for vibratory extraction of 30 in (76.2 cm) steel pile.
HASE: Harbor seal density 3.957 animals/km\2\.
CASL: California density 1.61 animals/km\2\.


              Table 10--Estimated Take by Level A and Level B Harassment Proposed for Authorization
----------------------------------------------------------------------------------------------------------------
                                                                      Maximum         Maximum      Estimate take
                                                                     estimated       estimated         as a
     Species common name        Scientific name       Stock           level A         level B      percentage of
                                                                   harassment *    harassment **    population
----------------------------------------------------------------------------------------------------------------
California sea lion ***......  Zalophus          U.S............               2              25           0.011
                                californianus.
Harbor seal..................  Phoca vitulina    California.....               8              50           0.187
                                richardii.
----------------------------------------------------------------------------------------------------------------
Source: NMFS SARs 2015, 2021.
* Based on 3 days of vibratory removal plus 2 days of impact driving (36 in (91.4 cm), 48 in (121.9 cm) piles
  only).
** Based on 3 days of vibratory removal plus 2 days of vibratory installation (36 in (91.4 cm), 48 in (121.9 cm)
  piles only).
*** To account for the increase in California sea lion density due to potential El Ni[ntilde]o conditions, the
  daily take estimated from the density has been increased by a factor of 10 for each day that pile driving or
  removal occurs.

Proposed Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses

[[Page 42318]]

(latter not applicable for this action). NMFS regulations require 
applicants for incidental take authorizations to include information 
about the availability and feasibility (economic and technological) of 
equipment, methods, and manner of conducting the activity or other 
means of effecting the least practicable adverse impact upon the 
affected species or stocks, and their habitat (50 CFR 216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, NMFS 
considers two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned), and;
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, and impact on 
operations.
    WETA must ensure that construction supervisors and crews, the 
monitoring team, and relevant WETA staff are trained prior to the start 
of all pile driving activities, 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.

Timing Restrictions

    All piling activities shall be conducted between June 1 and 
November 30, when the likelihood of sensitive fish species being 
present in the work area is minimal, following U.S. Army Corps of 
Engineer's Proposed Additional Procedures and Criteria for Permitting 
Projects under a Programmatic Determination of Not Likely to Adversely 
Affect Select Listed Species in California (USACE, 2018). Consistent 
with municipal code, noise-generating construction activities would be 
limited to the hours between 0700 and 1900 Monday through Friday, and 
0800 and 1300 on Saturdays.

Protected Species Observers

    The placement of PSOs during all pile driving activities (described 
in the Proposed Monitoring and Reporting section) would ensure that the 
entire shutdown zone is visible. Should environmental conditions 
deteriorate such that the entire shutdown zone would not be visible 
(e.g., fog, heavy rain), pile driving would be delayed until the PSO is 
confident marine mammals within the shutdown zone could be detected.
    PSOs would monitor the full shutdown zones and the Level B 
harassment zones to the extent practicable. Monitoring zones provide 
utility for observing by establishing monitoring protocols for areas 
adjacent to the shutdown zones. Monitoring zones enable observers to be 
aware of and communicate the presence of marine mammals in the project 
areas outside the shutdown zones and thus prepare for a potential 
cessation of activity should the animal enter the shutdown zone.

Pre- and Post-Activity Monitoring

    Monitoring must take place from 30 minutes prior to initiation of 
pile driving activities (i.e., pre-clearance monitoring) through 30 
minutes post-completion of pile driving. 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 
monitoring zones for a period of 30 minutes. The shutdown zone would be 
considered cleared when a marine mammal has not been observed within 
the zone for a 30-minute period. If a marine mammal is observed within 
the shutdown zones listed in Table 11, pile driving activity would be 
delayed or halted. 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).

Soft-Start Procedures for Impact Driving

    Soft-start procedures 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. If 
impact pile driving is necessary to achieve required tip elevation, 
WETA staff and/or 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 for Impact Driving

    A bubble curtain must be employed during all impact pile 
installation of piles to interrupt the acoustic pressure and reduce 
impact on marine mammals. The bubble curtain must distribute air 
bubbles around 100 percent of the piling circumference for the full 
depth of the water column. The lowest bubble ring must be in contact 
with the mudline for the full circumference of the ring. The weights 
attached to the bottom ring must ensure 100 percent substrate contact. 
No parts of the ring or other objects may prevent full substrate 
contact. Air flow to the bubblers must be balanced around the 
circumference of the pile.

Shutdown Zones

    WETA must establish shutdown zones for all 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 would be based upon the Level A harassment zone for each 
pile size/type and driving method where applicable, as shown in Table 
6. A minimum shutdown zone of 10 m would be required for all in-water 
construction activities to avoid physical interaction with marine 
mammals. For pile driving, the radii of the shutdown zones are rounded 
to the next largest 10 m interval in comparison to the Level A 
harassment zone for each activity type. If a marine mammal is observed 
entering or within a shutdown zone during pile driving activity, the 
activity must be stopped until there is visual confirmation that the 
animal has left the zone or the animal is not sighted for a period of 
15 minutes. Proposed shutdown zones for each activity type are shown in 
Table 11.
    All marine mammals would be monitored in the Level B harassment 
zones and throughout the area as far as visual monitoring can take 
place. If a marine mammal enters the Level B harassment zone, in-water 
activities would continue and PSOs would document the animal's presence 
within the estimated harassment zone.

[[Page 42319]]



                                                    Table 11--Proposed Shutdown and Harassment Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                       Shutdown zone   Shutdown zone
                 Method                            Pile type          Pile size (in)    for phocids    for otariids       Level B harassment zone (m)
                                                                                            (m)             (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact, installation....................  Steel.....................              36             830              60  736
Impact, installation....................  Steel.....................              48             140              10  631
Vibratory, extraction *.................  Steel.....................              30              40              10  4,200 W; 1,700 E
Vibratory, installation *...............  Steel.....................              36              40              10  4,200 W; 1,700 E
Vibratory, installation *...............  Steel.....................              48              10              10  4,200 W; 1,700 E
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Vibratory driving of 36 in (91.4 cm) piles used as proxy for vibratory extraction of 30 in (76.2 cm) piles.
* Constrained by bends in the Oakland Estuary and relatively shallow bathymetry near the shipping channel: 4,200 m (13,780 ft) west, 1, 700 m (5,577 ft)
  east.

    Based on our evaluation of the applicant's proposed measures, NMFS 
has preliminarily determined that the proposed mitigation measures 
provide the means of effecting the least practicable impact on the 
affected species or stocks and their habitat, paying particular 
attention to rookeries, mating grounds, and areas of similar 
significance.

Proposed Monitoring and Reporting

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

Visual Monitoring

    Marine mammal monitoring must be conducted in accordance with the 
conditions in this section and this IHA. Marine mammal monitoring 
during pile driving activities would be conducted by PSOs meeting NMFS' 
standards and in a manner consistent with the following:
     PSOs must be independent of the activity contractor (for 
example, employed by a subcontractor) and have no other assigned tasks 
during monitoring periods;
     At least one PSO would have prior experience performing 
the duties of a PSO during construction activity pursuant to a NMFS-
issued incidental take authorization;
     Other PSOs may substitute other relevant experience, 
education (degree in biological science or related field), or training 
for prior experience performing the duties of a PSO during construction 
activity pursuant to a NMFS-issued incidental take authorization;
     Where a team of three or more PSOs is required, a lead 
observer or monitoring coordinator must be designated. The lead 
observer must have prior experience performing the duties of a PSO 
during construction activity pursuant to a NMFS-issued incidental take 
authorization; and
     PSOs must be approved by NMFS prior to beginning any 
activity subject to the IHA.
    PSOs should have the following additional qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    WETA would have 1-3 PSOs stationed at the best possible vantage 
points in the project area to monitor during all pile driving 
activities. Monitoring would occur from elevated locations along the 
shoreline or on vessels where the entire shutdown zones are visible. 
PSOs would be equipped with high quality binoculars for monitoring and 
radios or cells phones for maintaining contact with work crews. 
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. Pile driving 
activities include the time to install or

[[Page 42320]]

remove a single pile or series of piles, as long as the time elapsed 
between uses of the pile driving equipment is no more than 30 minutes.

Pre-Construction Monitoring

    In addition to monitoring on days that pile removal and driving 
would occur, as proposed by the applicant, WETA would conduct pre-
construction monitoring. Prior to initiation of in-water construction, 
a qualified NMFS-approved PSO will conduct monitoring of marine mammals 
to update existing information on species occurrence in and near the 
project area, their movement patterns, and their site use. This pre-
construction monitoring will take place at least 5 days prior to the 
start of in-water construction and will cover a period of at least 1 
week (with at least 5 days of actual observation over a period of 4 
hours each day), 2 hours in the morning at the time that construction 
activities would begin and 2 hours at midday.

Reporting

    WETA will provide the following reporting as necessary during 
active pile driving activities:
     The applicant will report any observed injury or mortality 
as soon as feasible and in accordance with NMFS' standard reporting 
guidelines. Reports will be made by phone (866-767-6114) and by email 
([email protected]) and will include the following:
    [cir] Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    [cir] Species identification (if known) or description of the 
animal(s) involved;
    [cir] Condition of the animal(s) (including carcass condition if 
the animal is dead);
    [cir] Observed behaviors of the animal(s), if alive;
    [cir] If available, photographs or video footage of the animal(s); 
and,
    [cir] General circumstances under which the animal was discovered.
     An annual report summarizing the prior year's activities 
will be provided that fully documents the methods and monitoring 
protocols, summarizes the data recorded during monitoring, estimates 
the number of listed marine mammals that may have been incidentally 
taken during project pile driving, and provides an interpretation of 
the results and effectiveness of all monitoring tasks. The annual draft 
report will be provided no later than 90 days following completion of 
construction activities. Any recommendations made by NMFS will be 
addressed in the final report, due after the IHA expires and including 
a summary of all monitoring activities, prior to acceptance by NMFS. 
Final reports will follow a standardized format for PSO reporting from 
activities requiring marine mammal mitigation and monitoring.
     All PSOs will use a standardized data entry format (see 
Appendix B of the IHA application).

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 both 
California sea lions and harbor seals, given that the anticipated 
effects of this activity on these different marine mammal stocks are 
expected to be similar. There is little information about the nature or 
severity of the impacts, or the size, status, or structure of any of 
these species or stocks that would lead to a different analysis for 
this activity.
    Pile driving and removal activities have the potential to disturb 
or displace marine mammals. Specifically, the project activities may 
result in take, in the form of Level A and Level B harassment from 
underwater sounds generated from pile driving and removal. Potential 
takes could occur if individuals are present in the ensonified zone 
when these activities are underway.
    The proposed takes by Level A and Level B harassment would be due 
to potential behavioral disturbance, TTS, and PTS. No mortality is 
anticipated given the nature of the activity and measures designed to 
minimize the possibility of injury to marine mammals. The potential for 
harassment is minimized through the construction method and the 
implementation of the planned mitigation measures (see Proposed 
Mitigation section).
    The Level A harassment zones identified in Table 6 are based upon 
an animal exposed to impact pile driving multiple piles per day. 
Considering duration of impact driving each pile (up to 20 minutes) and 
breaks between pile installations (to reset equipment and move pile 
into place), this means an animal would have to remain within the area 
estimated to be ensonified above the Level A harassment threshold for 
multiple hours. This is highly unlikely given marine mammal movement 
throughout the area. If an animal was exposed to accumulated sound 
energy, the resulting PTS would likely be small (e.g., PTS onset) at 
lower frequencies where pile driving energy is concentrated, and 
unlikely to result in impacts to individual fitness, reproduction, or 
survival.
    The nature of the pile driving project precludes the likelihood of 
serious injury or mortality. For all species and stocks, take would 
occur within a limited, confined area (north-central San Francisco Bay 
including Richardson's Bay) of the stock's range. Level A and Level B 
harassment will be reduced to the level of least practicable adverse 
impact through use of mitigation measures described herein. Further, 
the amount of take proposed to be authorized is extremely small when 
compared to stock abundance.
    Behavioral responses of marine mammals to pile driving at the 
project site, if any, are expected to be mild and temporary. Marine 
mammals within the Level B harassment zone may not show any visual cues 
they are disturbed by activities or could become alert, avoid the area, 
leave the area, or display other mild responses that are not observable 
such as changes in vocalization patterns. Given the short duration of 
noise-generating activities per day and that pile driving and removal 
would occur across 6 consecutive days, any

[[Page 42321]]

harassment would be temporary. There are no other areas or times of 
known biological importance for any of the affected species.
    In addition, it is unlikely that minor noise effects in a small, 
localized area of habitat would have any effect on the stocks' ability 
to recover. In combination, we believe that these factors, as well as 
the available body of evidence from other similar activities, 
demonstrate that the potential effects of the specified activities will 
have only minor, short-term effects on individuals. The specified 
activities are not expected to impact rates of recruitment or survival 
and will therefore not result in population-level impacts.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect any of the species 
or stocks through effects on annual rates of recruitment or survival:
     No serious injury or mortality is anticipated or 
authorized;
     The specified activities and associated ensonified areas 
are very small relative to the overall habitat ranges of both species;
     The project area does not overlap with known BIAs or ESA-
designated critical habitat;
     The lack of anticipated significant or long-term effects 
to marine mammal habitat;
     The presumed efficacy of the mitigation measures in 
reducing the effects of the specified activity; and,
     Monitoring reports from similar work in San Francisco Bay 
have documented little to no effect on individuals of the same species 
impacted by the specified activities (AECOM, 2022; AECOM, 2023).
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from the proposed activity will have a negligible impact on 
all affected marine mammal species or stocks.

Small Numbers

    As noted previously, only take of small numbers of marine mammals 
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. When the predicted number of 
individuals to be taken is fewer than one-third of the species or stock 
abundance, the take is considered to be of small numbers. Additionally, 
other qualitative factors may be considered in the analysis, such as 
the temporal or spatial scale of the activities.
    The amount of take NMFS has authorized is below one-third of the 
estimated stock abundances for all seven stocks (see Table 9). For both 
stocks, the proposed take of individuals is less than 1 percent of the 
abundance of the affected stock. This is likely a conservative estimate 
because it assumes all takes are of different individual animals, which 
is likely not the case. Some individuals may return multiple times in a 
day, but PSOs would count them as separate takes if they cannot be 
individually identified.
    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals would be taken relative to the population 
size of the affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
determined that the total taking of affected species or stocks would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

Endangered Species Act

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA; 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally whenever we propose to authorize take for 
endangered or threatened species.
    No incidental take of ESA-listed species is proposed for 
authorization or expected to result from this activity. Therefore, NMFS 
has determined that formal consultation under section 7 of the ESA is 
not required for this action.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to WETA for conducting pile removal and driving in the 
Oakland Inner Harbor at Alameda, California, for one year from the date 
of issuance, provided the previously mentioned mitigation, monitoring, 
and reporting requirements are incorporated. A draft of the proposed 
IHA can be found at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this notice of proposed IHA for the proposed 
construction project. We also request comment on the potential renewal 
of this proposed IHA as described in the paragraph below. Please 
include with your comments any supporting data or literature citations 
to help inform decisions on the request for this IHA or a subsequent 
renewal IHA.
    On a case-by-case basis, NMFS may issue a one-time, one-year 
renewal IHA following notice to the public providing an additional 15 
days for public comments when (1) up to another year of identical or 
nearly identical activities as described in the Description of Proposed 
Activity section of this notice is planned or (2) the activities as 
described in the Description of Proposed Activity section of this 
notice would not be completed by the time the IHA expires and a renewal 
would allow for completion of the activities beyond that described in 
the Dates and Duration section of this notice, provided all of the 
following conditions are met:
     A request for renewal is received no later than 60 days 
prior to the needed renewal IHA effective date (recognizing that the 
renewal IHA expiration date cannot extend beyond one year from 
expiration of the initial IHA); and
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
requested renewal IHA are identical to the activities analyzed under 
the initial IHA, are a subset of the activities, or include changes so 
minor (e.g., reduction in pile size) that the changes do not affect the 
previous analyses, mitigation and monitoring requirements, or take 
estimates (with the exception of reducing the type or amount of take); 
and

[[Page 42322]]

    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized.
    Upon review of the request for renewal, the status of the affected 
species or stocks, and any other pertinent information, NMFS determines 
that there are no more than minor changes in the activities, the 
mitigation and monitoring measures will remain the same and 
appropriate, and the findings in the initial IHA remain valid.

    Dated: June 26, 2023.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2023-13899 Filed 6-29-23; 8:45 am]
BILLING CODE 3510-22-P