[Federal Register Volume 88, Number 159 (Friday, August 18, 2023)]
[Notices]
[Pages 56595-56606]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-17744]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XD136]


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; issuance of an incidental harassment authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued an incidental harassment authorization (IHA) to 
the San Francisco Bay Area Water Emergency Transportation Authority 
(WETA) to incidentally harass, by Level A and Level B harassment, 
marine mammals during construction activities associated with the 
refurbishment of the Alameda Main Street Ferry Terminal in Alameda, 
California. There are no changes from the proposed authorization to the 
final authorization.

DATES: This authorization is effective from August 15, 2023, through 
August 14, 2024.

ADDRESSES: 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/action/incidental-take-authorization-san-francisco-bay-area-water-emergency-transportation. In case of problems accessing these documents, please 
call the contact listed below.

FOR FURTHER INFORMATION CONTACT: Alyssa Clevenstine, Office of 
Protected Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Background

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

Summary of Request

    On February 9, 2023, NMFS received a request from WETA for an IHA 
to take marine mammals incidental to construction activities associated 
with refurbishment of the Alameda Main Street Ferry Terminal in 
Alameda, CA. 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, and the 
applicant submitted a minor modification on June 12, 2023. WETA's 
request is for take of harbor seals (Phoca vitulina) and California sea 
lions (Zalophus californianus) by Level B harassment, and by Level A 
harassment for certain activities. Neither WETA nor NMFS expect serious 
injury or mortality to result from this activity and, therefore, an IHA 
is appropriate. This final notice also includes a description of the 
hydroacoustic monitoring report, which was accidentally omitted from 
the proposed notice (88 FR 42304, June 30, 2023). There are no changes 
from the proposed IHA to the final IHA.

Description of the Specified Activity

    WETA plans to refurbish the Alameda Main Street Ferry Terminal in 
the Oakland Inner Harbor, Alameda, CA, to update and replace ageing 
ferry terminal components and structural support. WETA plans to use 
vibratory extraction to remove four existing 30 inch (in) (76.2 
centimeter (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 consecutive days 
(5 days in water, 1 day on land) of piling activities will occur during 
the course of construction (4-6 weeks) from August through November 
2023 (Table 1). WETA plans 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. 
All project activities for which take is being requested will be 
located in the Oakland Inner Harbor, Alameda (see Figure 2 in IHA 
application).
    A detailed description of the planned construction project is 
provided in the Federal Register notice for the proposed IHA (88 FR 
42304, June 30, 2023). Since that time, no changes have been made to 
the planned activities. Therefore, a detailed description is not 
provided here. Please refer to that Federal Register notice for the 
description of the specified activity.

[[Page 56596]]



                                                  Table 1--Pile Extraction and Installation Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                            Duration of      Estimated
                                                                                                                             vibratory       blows of
               Pile activity                          Structure              Pile size     Piles per day    Duration of    activity per   impact driving
                                                                               (in)                          activity          pile          per pile
                                                                                                                             (minutes)      (strikes) *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Extraction................................  Removal of existing guide                 30               4             1-3              45             N/A
                                             piles.
Installation..............................  Terminal bridge and                       48               1               1              45           1,015
                                             foundation replacement.
Installation..............................  Float replacement (guide                  36               6               1              45           1,015
                                             piles and donut fender
                                             piles).
--------------------------------------------------------------------------------------------------------------------------------------------------------
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.

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to WETA was published in 
the Federal Register on June 30, 2023 (88 FR 42304). That notice 
described, in detail, WETA's planned activities, the marine mammal 
species that may be affected by the activities, and the anticipated 
effects on marine mammals. In that notice, we requested public input on 
the request for authorization described therein, our analyses, the 
proposed authorization, and any other aspect of the notice of proposed 
IHA, and requested that interested persons submit relevant information, 
suggestions, and comments. During the 30-day public comment period, no 
substantive public comments were received.

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 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 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\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                      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\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
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).
Family Phocidae (earless seals):
    Harbor seal....................  Phoca vitulina          California............  -/-; N             30,968 (0.157; 27,348;        1,641         42.8
                                      richardii.                                                         2012).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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\ 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.


[[Page 56597]]

    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.
    A detailed description of the species likely to be affected by this 
project, including brief introductions to the species and relevant 
stocks as well as available information regarding population trends and 
threats, and information regarding local occurrence, were provided in 
the Federal Register notice for the proposed IHA (88 FR 42304, June 30, 
2023); since that time, we are not aware of any changes in the status 
of these species and stocks; therefore, detailed descriptions are not 
provided here. Please refer to that Federal Register notice for these 
descriptions. Please also refer to the NMFS website (https://www.fisheries.noaa.gov/find-species) for generalized species accounts.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Not all marine mammal species have equal 
hearing capabilities (e.g., Richardson et al., 1995, Wartzok and 
Ketten, 1999, Au and Hastings, 2008). To reflect this, Southall et al. 
(2007, 2019) recommended that marine mammals be divided into hearing 
groups based on directly measured (behavioral or auditory evoked 
potential techniques) or estimated hearing ranges (behavioral response 
data, anatomical modeling, etc.). Note that no direct measurements of 
hearing ability have been successfully completed for mysticetes (i.e., 
low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al. (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in Table 3.

                  Table 3--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
            Hearing group                 Generalized  hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen   7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans           150 Hz to 160 kHz.
 (dolphins, toothed whales, beaked
 whales, bottlenose whales).
High-frequency (HF) cetaceans (true    275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 Cephalorhynchid, Lagenorhynchus
 cruciger & L. australis).
Phocid pinnipeds (PW) (underwater)     50 Hz to 86 kHz.
 (true seals).
Otariid pinnipeds (OW) (underwater)    60 Hz to 39 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006, Kastelein et al., 2009, Reichmuth 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

    The effects of underwater noise from WETA's construction activities 
have the potential to result in behavioral harassment of marine mammals 
in the vicinity of the project area. The notice of the proposed IHA (88 
FR 42304, June 30, 2023) included a discussion of the effects of 
anthropogenic noise on marine mammals and the potential effects of 
underwater noise from WETA's construction activities on marine mammals 
and their habitat. That information and analysis is incorporated by 
reference into this final IHA determination and is not repeated here; 
please refer to the notice of the proposed IHA (88 FR 42304, June 30, 
2023).

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
authorized through this IHA, which informed 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 permanent threshold shift (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 mitigation and monitoring measures are expected to 
minimize the severity of the taking to the extent practicable (see 
Mitigation and Monitoring and Reporting sections).
    As described previously, no serious injury or mortality is 
anticipated or authorized for this activity. Below we describe how the 
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

[[Page 56598]]

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 authorized 
take estimates.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment).
    Level B Harassment--Though significantly driven by received level, 
the onset of behavioral disturbance from anthropogenic noise exposure 
is also informed to varying degrees by other factors related to the 
source or exposure context (e.g., frequency, predictability, duty 
cycle, duration of the exposure, signal-to-noise ratio, distance to the 
source), the environment (e.g., bathymetry, other noises in the area, 
predators in the area), and the receiving animals (hearing, motivation, 
experience, demography, life stage, depth) and can be difficult to 
predict (e.g., Southall et al., 2007, 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 sound pressure 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 temporary 
threshold shift (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 construction activities include 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 
construction activities include the use of impulsive (impact hammer) 
and non-impulsive (vibratory hammer) sources.
    These thresholds are provided in Table 4 below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS' 2018 Technical Guidance, which may be accessed at: 
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 (TL) 
coefficient.
    Pile driving activities, using an impact hammer as well as a 
vibratory hammer, 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 and sound exposure 
levels (SEL) for planned removal and installation activities derived 
from this review are shown in Table 5.

[[Page 56599]]



                                                          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 \2\-sec              Source
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact *..........................  Water................              36             206             188             178  Caltrans 2020.
Impact *..........................  Water................              48             208             187             174  Caltrans 2020.
Vibratory.........................  Water................     [dagger] 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.
[dagger] Vibratory driving of 36 in piles used as proxy for vibratory extraction of 30 in piles.

    Level B Harassment Zone--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 planned activity in 
the absence of specific modeling and site-specific information. Sound 
propagation in the Oakland Inner Harbor is limited by bends in the 
channel and 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 (see Figure 1 
in the IHA application). Therefore, the distance for noise impacts 
would be limited to 4,200 m west and 1,700 m east of the project 
location. The Level A shutdown zones and Level B harassment zones for 
WETA's planned activities are shown in Table 6.

         Table 6--Distance to the Level A and Level B Harassment Thresholds for 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 56600]]



                                           Table 7--Sound Levels Used for Predicting Underwater Sound Impacts
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 Pile                                                      Peak SPL         RMS SPL      SEL  attenuated
       Driving method             Location       size   Peak SPL dB re   RMS SPL dB re    SEL dB re 1    attenuated *    attenuated *   * dB re 1 [mu]Pa
                                                 (in)      1 [mu]Pa        1 [mu]Pa      [mu]Pa\2\-sec  dB re 1 [mu]Pa  dB re 1 [mu]Pa       \2\-sec
--------------------------------------------------------------------------------------------------------------------------------------------------------
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 5 dB reduction in source level.
NA: No additional attenuation applied to piles driven with a vibratory hammer.

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 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.
    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's 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 conditions, the density 
of California sea lions in San Francisco Bay may be much greater than 
the value used above. Development of El Ni[ntilde]o conditions in 2023 
is ongoing, with chances of a strong event currently estimated at 56 
percent (https://www.climate.gov, June 8, 2023). To account for the 
potential increase in California sea lions within San Francisco Bay 
during the 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 (approx. 10.4 kilometers (km) (6.47 mi) west northwest) 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 project 
area is located outside of the Oakland Inner Harbor at Alameda Point 
(approx. 37.770127[deg], -122.296819[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 (approx. 6.2 km (3.8 mi) west northwest) 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 authorized.
    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 and 4 in the IHA application and 82 FR 
17799, April 13, 2017).

Maximum number of animals exposed per activity = Density x Level A or 
Level B harassment 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 zero to two 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 use the Oakland Inner Harbor but extensive surveys have not 
been completed in the 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

    Finally, due to the probability of El Ni[ntilde]o 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

[[Page 56601]]

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    Duration of   Estimated     Level A take     Total
          Construction activity                (in)                Species              take/day     activity     incidental     requested      Level A
                                                                                                       (day)         take      (animals/day)      take
--------------------------------------------------------------------------------------------------------------------------------------------------------
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
  El Ni[ntilde]o 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
     Construction activity           (in)          Condition            Species         take/day     activity     incidental     requested      Level B
                                                                                                       (day)         take      (animals/day)      take
--------------------------------------------------------------------------------------------------------------------------------------------------------
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
  El Ni[ntilde]o 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 for Authorization
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                            Maximum
                                                                                                           Maximum         estimated      Estimate  take
           Species common name                    Scientific name                    Stock                estimated         Level B            as a
                                                                                                           Level A         harassment     percentage of
                                                                                                         harassment *       [dagger]        population
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion [Dagger].............  Zalophus californianus......  U.S.........................                2               25            0.011
Harbor seal..............................  Phoca vitulina richardii....  California..................                8               50            0.187
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source: NMFS SARs 2015, 2021.
* Based on 3 days of vibratory removal plus 2 days of impact installation (36 in (91.4 cm), 48 in (121.9 cm) piles only).
[dagger] 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).
[Dagger] 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.

Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks, and their habitat (50 CFR 
216.104(a)(11)).

[[Page 56602]]

    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 
Engineers' (USACE) 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 will be limited to the hours between 0700 and 1900 Monday 
through Friday, and 0800 and 1300 on Saturdays.

Protected Species Observers

    The placement of protected species observers (PSOs) during all pile 
driving activities (described in the Monitoring and Reporting section) 
will 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 will be 
delayed until the PSO is confident marine mammals within the shutdown 
zone could be detected.
    PSOs will 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 relevant 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 will observe the shutdown and 
monitoring zones for a period of 30 minutes. The shutdown zone will be 
considered cleared when a marine mammal has not been observed within 
the zone for a 30-minute period. If a marine mammal is observed within 
the shutdown zones listed in Table 11, pile driving activity will be 
delayed or halted. If work ceases for more than 30 minutes, the pre-
activity monitoring of the shutdown zones will 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 will 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 will 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

    WETA plans to use a bubble curtain to mitigate effects from impact 
pile driving on marine mammals, and NMFS concurs with the effectiveness 
of this measure. Therefore, a bubble curtain will be employed during 
all impact installation of piles. 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 are 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 meters (m) is 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. Shutdown zones for each activity type are shown in Table 
11.
    All marine mammals will 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 will continue and PSOs will document the animal's presence 
within the estimated harassment zone.

[[Page 56603]]



                                                         Table 11--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 planned measures, NMFS 
has determined that the planned 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.

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 will 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 will 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 will have one to three PSOs stationed at the best possible 
vantage points in the project area to monitor during all pile removal 
and driving activities. Monitoring will occur from elevated locations 
along the shoreline or on vessels where the entire shutdown zones are 
visible. PSOs will be equipped with high quality binoculars for 
monitoring and radios or cells phones for maintaining contact with work 
crews. Monitoring will be conducted 30 minutes before, during, and 30 
minutes after all in-water construction activities. In addition, PSOs 
will record all incidents of marine mammal occurrence, regardless of 
distance from activity, and will document any behavioral reactions in 
concert with distance from piles being driven or removed. Pile driving 
activities include the time to install or remove a single

[[Page 56604]]

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 
will occur, as proposed by the applicant, WETA will 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.

Hydroacoustic Monitoring

    WETA will conduct hydroacoustic monitoring during all impact 
driving activities. Acoustic monitoring must be conducted in accordance 
with the Acoustic Monitoring Plan, to be submitted to NMFS no less than 
30 days prior to commencement of pile driving activity.
    The acoustic monitoring report must contain the informational 
elements described in the Acoustic Monitoring Plan and, at a minimum, 
must include:
     Hydrophone equipment and methods: recording device, 
sampling rate, distance (m) from the pile where recordings were made; 
depth of water at the pile location and recording device(s);
     Type and size of pile being driven, substrate type, method 
of driving during recordings (e.g., hammer model and energy), and total 
pile driving duration;
     For all impact driving, a detailed description of the 
sound attenuation device used and the duration of its use per pile;
     For impact pile driving (per pile): Number of strikes and 
strike rate; depth of substrate to penetrate; pulse duration and mean, 
median, and maximum sound levels (dB re: 1 [micro]Pa): root mean square 
sound pressure level (SPLrms), cumulative sound exposure 
level (SELcum), peak sound pressure level 
(SPLpeak), and single-strike sound exposure level 
(SELs-s);
     One-third octave band spectrum and power spectral density 
plots (average per pile type or for each individual pile); and
     Sound measurement data shall be provided to NMFS in 
tabular spreadsheet format (Microsoft Excel or similar).

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 the construction activities 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 these activities.
    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 authorized takes by Level A and Level B harassment would be due 
to potential behavioral disturbance, TTS, and PTS. No mortality or 
serious injury 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 mitigation measures 
(see Mitigation section).
    The Level A harassment zones identified in Table 11 are based upon 
an animal exposed to impact pile driving of

[[Page 56605]]

multiple piles in a single 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 above the Level A harassment 
threshold, 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 project precludes the likelihood of serious 
injury or mortality. For all species and stocks, take would occur 
within a limited, confined area (Oakland Inner Harbor, San Francisco 
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 
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 harassment would be 
temporary. There are no other areas or times of known biological 
importance for any of the affected species that are likely to be 
impacted by the planned activities.
    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 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 Biologically 
Important Areas (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 monitoring and mitigation 
measures, NMFS finds that the total marine mammal take from the 
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 both species (see Table 10). For both 
stocks, the authorized take of individuals is less than 0.2 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 activity (including 
the mitigation and monitoring measures) and the anticipated take of 
marine mammals, NMFS 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 authorized for this 
activity. Therefore, NMFS has determined that formal consultation under 
section 7 of the ESA is not required for this action.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an IHA) 
with respect to potential impacts on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for NAO 216-6A, which do not 
individually or cumulatively have the potential for significant impacts 
on the quality of the human environment and for which we have not 
identified any extraordinary circumstances that would preclude this 
categorical exclusion. Accordingly,

[[Page 56606]]

NMFS has determined that the issuance of this IHA qualifies to be 
categorically excluded from further NEPA review.

Authorization

    NMFS has issued an IHA to WETA for the potential harassment of 
small numbers of two marine mammal species incidental to construction 
activities in the Oakland Inner Harbor at Alameda, California, that 
includes the previously explained mitigation, monitoring, and reporting 
requirements.

    Dated: August 14, 2023.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2023-17744 Filed 8-17-23; 8:45 am]
BILLING CODE 3510-22-P