[Federal Register Volume 88, Number 191 (Wednesday, October 4, 2023)]
[Notices]
[Pages 68575-68586]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-21920]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XD398]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to U.S. Navy Mole Pier South Berth 
Floating Dry Dock Project

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 U.S. Navy to incidentally harass marine mammals during construction 
associated with Mole Pier Floating Dry Dock project at Naval Base San 
Diego.

DATES: This Authorization is effective from March 1, 2024 through 
February 28, 2025.

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/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of problems accessing these documents, please call 
the contact listed below.

FOR FURTHER INFORMATION CONTACT: Steven Tucker, 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 16, 2022, NMFS received a request from the U.S. Navy, 
Navy Base San Diego (or, the Navy) for an IHA to take marine mammals 
incidental to Mole Pier Floating Dry Dock project in south-central San 
Diego Bay. The application was deemed adequate and complete on May 1, 
2023. The Navy's request is for authorization to incidentally take 
California sea lions, harbor seals, and bottlenose dolphins, by Level B 
harassment only. Neither the U.S. Navy nor NMFS expect serious injury 
or mortality to result from this activity and, therefore, an IHA is 
appropriate.
    NMFS previously issued an IHA to the U.S. Navy for similar work (87 
FR 65578, October 31, 2022). The U.S. Navy has complied with all the 
requirements (e.g., mitigation, monitoring, and reporting) of the 
previous IHA, and information regarding their monitoring results is 
publicly available at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.

Description of Activity

Overview

    The U.S. Navy request is associated with demolition and 
construction activities related to partial demolition and construction 
of a floating dry dock and related facilities at Mole Pier, Navy Base 
San Diego. The purpose of the Mole Pier South Berth Floating Dry Dock 
(FDD) Project is to overcome current shortfall in dry dock availability 
for repair and maintenance of vessels at Navy Base San Diego. The 
planned activity remedies some of the constraints resulting from aging 
or obsolete facilities.
    Activities that may result in Level B harassment include removal of 
existing piles and installation of new piles to support facilities that 
are necessary for repair and maintenance of vessels in furtherance of 
the U.S. Navy's Congressionally mandated responsibilities under 10 
U.S.C. 5062. The specified activity also includes dredging and 
demolition of the existing deck at the mooring wharf, installation of 
mooring attachments, installation of a steel floating dry dock and 
construction of a ramp and pier. Demolition activities include 
vibratory removal or clipping of up to fifty-four 24 x 24-inch square 
concrete piles and seven 24-inch octagonal concrete piles. Pile driving 
and extraction activities will take place during 33 days of in-water 
work at the Mole Pier mooring wharf and the ramp. The Test Pile Program 
(TPP) described in the notice of proposed authorization (88 FR 47111, 
July 21, 2023) will not be undertaken. Permanent pile installations, 
expected to occur via impact hammer and/or jetting, consist of eighty 
24-inch octagonal concrete piles at the mooring wharf and twenty-one 
24-inch octagonal piles for the Ramp Pier and access to the FDD.

Dates and Duration

    The U.S. Navy requested that the IHA be effective for a period of 1 
year, from March 1, 2024 through February 28, 2025. During this period, 
the Navy expects to complete the pile driving and removal portions of 
the project during 59 workdays that may be non-consecutive, with all 
in-water activities conducted during daylight hours. Pile driving and 
removal activities may occur at any time during the proposed 1-year 
period of effectiveness.

Specific Geographic Region

    The activities would occur in the south-central portion of San 
Diego Bay. San Diego Bay (the Bay) is a narrow, crescent-shaped natural 
embayment oriented northwest-southeast with an approximate length of 24 
kilometers (km) and a total area of roughly 4 km\2\ (11,000 acres; Port 
of San Diego, 2007). The width of the Bay ranges from 300 meters to 
5.800 meters and depths range from 23 meters Mean Lower Low Water 
(MLLW) near the tip of Ballast Point to less than 1.2 meters at the 
southern end

[[Page 68576]]

(Merkel and Associates, Inc., 2009). Approximately half of the Bay is 
less than 4.5 meters deep and much of it is less than 15 meters deep 
(Merkel and Associates, Inc., 2009). The northern and central portions 
of the Bay have been shaped by historical dredging and filling to 
support large ship navigation and shoreline development. The United 
States Army Corps of Engineers dredges the main navigation channel in 
the Bay to maintain a depth of 14 meters MLLW and is responsible for 
providing safe transit for private, commercial, and military vessels 
within the bay (NOAA, 2012). Outside of the navigation channel, the bay 
floor consists of platforms at depths that vary slightly (Merkel and 
Associates, Inc., 2009). Within the Central Bay, typical depths range 
from 10.7-11.6 meters MLLW to support large ship turning and anchorage, 
and small vessel marinas are typically dredged to depths of 4.6 meters 
MLLW (Merkel and Associates, Inc., 2009).
[GRAPHIC] [TIFF OMITTED] TN04OC23.012

    San Diego Bay is heavily used by commercial, recreational, and 
military vessels, with an average of 82,413 vessel movements (in or out 
of the Bay) per year (approximately 225 vessel transits per day), a 
majority of which are presumed to occur during daylight hours. This 
number of transits does not include recreational boaters that use San 
Diego Bay, estimated to number 200,000 annually (San Diego Harbor 
Safety Committee, 2009). Background (ambient) noise in the south-
central San Diego Bay averaged 126 decibels (dB) re: 1 micropascal 
([micro]Pa) in 2019 (Dahl and Dall'Osto, 2019). Therefore, noise from 
non-impulsive sources associated with the specified activities is 
assumed to become indistinguishable from background noise as it 
diminishes to 126 dB with distance from the source (Dahl and Dall'Osto, 
2019).

Detailed Description of the Specified Activity

    The proposed FDD installation and associated dredging activities 
would occur within San Diego Bay at the south berth of the Mole Pier, 
which is located approximately 1.6 km (1 mile) south of the main 
entrance gate to Navy Base San Diego (NBSD), immediately south of Pier 
8 and the Paleta Creek Channel, and north of Pier 10.
    The Mole Pier floating dry dock project includes the following 
phases:
    (1) Relocation of the USS Curtiss and hoteling facilities that are 
currently moored along the south berth of the Mole Pier;
    (2) Dredging at the Mole Pier FDD sump, approaches, and turning 
basin to increase water-depths as well as subsequent sediment disposal 
activities;
    (3) Partial demolition of the existing decking at the mooring 
wharf;
    (4) Installation of mooring attachments and upgrades at the mooring 
wharf;
    (5) Demolition of existing Ramp Pier;
    (6) Utility modifications;
    (7) Placement and operation of a steel FDD; and
    (8) Construction of a new Ramp Pier with vehicle access bridge from 
the quay wall southeast of the 1 Mole Pier to the FDD.

[[Page 68577]]



                       Table 1--Proposed (Parentheses) and Revised (Bold) Pile Activities
----------------------------------------------------------------------------------------------------------------
                                                                                                         Total
           Pile location                Pile size/type        Pile extraction      Piles/  Number of   estimated
                                                                 method \1\         day      piles       days
----------------------------------------------------------------------------------------------------------------
                                        Demolition (Pile Extraction) \ 1\
----------------------------------------------------------------------------------------------------------------
Mooring Wharf.....................  24-inch Square         --Hydraulic Pile             5   \3\ (24)       (5) 5
                                     Concrete.              Clipper.                              24       (2) 2
                                    24-inch Octagonal      --Vibratory                     \3\ (7) 7
                                     Concrete.              Extraction.
Ramp Pier.........................  24-inch Square         --High-pressure Water             (28) 29       (6) 6
                                     Concrete.              Jetting.
TPP (Cancelled/withdrawn).........  N/A..................                           (1) 0      (6) 0       (6) 0
                                                                                          ----------------------
    Total Piles Removed...........  .....................  .....................  .......    (65) 60     (19) 13
----------------------------------------------------------------------------------------------------------------
                                      Construction (Pile Installation) \2\
----------------------------------------------------------------------------------------------------------------
TPP (Cancelled/withdrawn).........  24-inch Octagonal      --Impact Hammer......    (1) 0      (0) 0       (0) 0
Mooring Wharf.....................   Concrete.             --High-pressure Water    (3) 3    (80) 48     (27) 16
                                                            Jetting.
Ramp Pier & Intermediate Support                                                             (21) 12       (7) 4
 Structure.
                                                                                          ----------------------
    Total Piles Installed.........  .....................  .....................  .......   (107) 60     (40) 20
                                                                                                     -----------
        Total In-Water Pile         .....................  .....................  .......  .........     (59) 33
         Extraction/Installation
         Days.
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ While other methods of pile extraction are possible, cutting off the piles at mudline is the most likely
  method that will be used to extract piles though vibratory extraction equipment could be used if conditions
  warrant. No Level A/B take analysis conducted on the other pile extraction methods.
\2\ Impact pile installation is the most likely method that will be used to install piles. High-pressure water
  jetting may be used either separately from, or at the same time as, impact pile installation.
\3\ The removal of the piles at the Mooring Wharf are dependent on interferences during the installation of new
  piles. The anticipated quantity of removed piles is small and will not exceed the listed values.

    Underwater demolition activities covered under this IHA application 
would occur over a period of 13 days at two primary locations: (1) the 
Mole Pier mooring wharf and (2) the Ramp Pier. Piles at the mooring 
wharf will only be removed if they obstruct installation of new piles. 
All of the piles that support the Ramp Pier are slated for removal and 
replacement in the course of constructing a new replacement pier. At 
both locations, the concrete pier deck would be saw cut longitudinally 
and transversely at mid-span of every bent, allowing for removal in 
large but manageable sections, with weights of less than 50 tons (45 
metric tons). While the section is rigged to the derrick crane, a 
hydraulic shearing tool attached to a barge-mounted excavator would be 
used to cut the piles just below pile cap. Once freed from the piles, 
the sections would be set onto a barge. Following the removal of the 
pier deck, the piles could be removed via multiple methods, including 
vibratory extraction, high-pressure water jetting, hydraulic pile 
clipper, wire saw, underwater chain saw, dead pull or via a combination 
of methods. Up to fifty-four 24-by-24-inch square concrete piles and 
seven 24-inch octagonal concrete piles would be removed from the area 
of the existing mooring wharf and the Ramp Pier.
    Any of the pile extraction activities cited above may occur as part 
of the Project-related activities. However, given that the methods 
other than vibratory pile extraction entail lower source levels, we 
assume that take will not result. Vibratory pile driving is the only 
demolition-related activity expected to potentially result in 
incidental Level B harassment and subsequent take of marine mammals.
    Pile installation activities would require 33 days. Similar to pile 
extraction activities, pile installation activities for the Project are 
broken up into separate phases: (1) installation of forty-eight 24-inch 
octagonal concrete piles at the mooring wharf; and (2) installation of 
twelve 24-inch octagonal concrete piles associated with the Ramp Pier 
and Intermediate Support Structure for personnel and vehicle access to 
the FDD. Piles installed for the mooring wharf and the Ramp Pier/
Intermediate Support Structure would occur via an impact pile driver, 
high-pressure water jetting, or a combination of both methods. 
Vibratory pile installation is not expected.
    The relocation of assets, dredging and sediment disposal, utility 
modifications, above-water demolition activities, and placement and 
operation of the FDD does not have the potential to result in 
harassment under the MMPA. Underwater sound associated with pile 
extraction and installation would have the potential to harass marine 
mammals. The demolition and construction elements analyzed in the IHA 
are described below and would occur over 33 days of in-water work over 
the 1 year period of authorization.
    Mitigation, monitoring, and reporting measures are described in 
detail later in this document (please see Mitigation and Monitoring and 
Reporting).

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to the Navy was 
published in the Federal Register on July 21, 2023 (88 FR 47111). That 
notice described, in detail, the Navy's 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. This proposed notice was available for a 30-
day public comment period. NMFS received no public comments.

Changes From the Proposed IHA to Final IHA

    The Navy provided information about additional changes to project 
design and implementation, foregoing the six-pile Test Pile Program 
described in the proposed IHA Federal Register notice. After further 
review, the Navy now expects most piles to be removed by clipping them 
at the mud line, rather than vibratory extraction. In addition, the 
total number of construction piles to be installed has been reduced 
from 107 to 60 and the number of piles slated for removal has been 
revised downward from 65 to 60. There will be a commensurate reduction 
in in-water workdays, from 59 to 33. Pile types, methods of removal and 
installation and project footprint are otherwise

[[Page 68578]]

unchanged. Due to the possibility of further adjustments to 
construction of the project, the Navy requests that the take estimates 
cited in the proposed IHA carry forward, and NMFS concurs with this 
request. There are no other changes. Therefore, NMFS has determined 
that the project changes do not affect the preliminary small numbers 
finding or negligible impact determination.

Description of Marine Mammals in the Area of Specified Activities

    The request provides information about marine mammals that are 
known to occur in the broader geographic region including near the 
mouth of San Diego Bay and North Bay. Based on monitoring of prior 
projects conducted at Navy Base San Diego and in the vicinity of the 
FDD project, three of the species discussed are most likely to occur in 
the project area: California sea lions, bottlenose dolphins, and harbor 
seals.
    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions, instead of reprinting the information. Additional 
information regarding population trends and threats may be found in 
NMFS' Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and 
more general information about these species (e.g., physical and 
behavioral descriptions) may be found on NMFS' website (https://www.fisheries.noaa.gov/find-species).
    Table 2 lists all species or stocks for which take is expected and 
proposed to be authorized for this activity, and summarizes information 
related to the population or stock, including regulatory status under 
the MMPA and Endangered Species Act (ESA) and Potential Biological 
Removal (PBR), where known. PBR is defined by the MMPA as the maximum 
number of animals, not including natural mortalities, that may be 
removed from a marine mammal stock while allowing that stock to reach 
or maintain its optimum sustainable population (as described in NMFS' 
SARs). While no serious injury or mortality is 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 the table represent 
the total number of individuals that make up a given stock. NMFS' stock 
abundance estimates for most species represent the total estimate of 
individuals within the geographic area, if known, that comprises that 
stock. 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 and are available online at: 
https://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/
                                                                                                \2\          abundance survey) \3\               SI \4\
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                                                  Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae
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Bottlenose dolphin..................  Tursiops truncatus.....  California coastal.....  N                   453...................        2.7       >2.0
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                                                               Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and sea lions)
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California Sea Lion.................  Zalophus californianus.  United States..........  N                   257,606...............     14,011       >321
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor seal.........................  Phoca vitulina.........  California.............  N                   30,968................      1,641         43
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation, Nmin is the minimum estimate of
  stock abundance. In some cases, CV is not applicable.
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, vessel strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A
  CV associated with estimated mortality due to commercial fisheries is presented in some cases.

    As indicated above, the 3 species in Table 2 temporally and 
spatially co-occur with the activity to the degree that take is 
reasonably likely to occur. Based on many years of observations and 
numerous Navy-funded surveys in San Diego Bay (Merkel and Associates, 
Inc., 2008; Sorensen and Swope, 2010; Graham and Saunders, 2014; Tierra 
Data Inc., 2016), other marine mammals rarely occur south of the 
Coronado Bay Bridge, are not known to occur near Naval Base San Diego, 
and any occurrence in the project area would be very rare. Therefore, 
while common dolphins (Delphinus delphis and Delphinus capensis), and 
gray whales (Eschrictius robustus) have been sighted in North Bay and 
reported near the mouth of San Diego Bay respectively (Naval Facilities 
Engineering Command, Southwest and Port of San Diego Bay, 2013), they 
are not anticipated to occur in the project area and no take of these 
species is anticipated or proposed to be authorized.

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

[[Page 68579]]

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

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

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

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from the Navy'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 47111, July 21, 2023) included a discussion of the 
effects of anthropogenic noise on marine mammals and the potential 
effects of underwater noise from the Navy's construction activities on 
marine mammals and their habitat. That information and analysis was 
considered in these final IHA determinations and is not repeated here; 
please refer to the Federal Register notice of proposed IHA (88 FR 
47111, July 21, 2023).

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
authorized through the 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).
    Here, authorized takes are by Level B harassment only, in the form 
behavioral response to noise, or short-term disruption of behavioral 
patterns resulting from exposure to sound generated during pile driving 
and extraction activities. Based on the nature of the activity, Level A 
harassment is neither anticipated nor authorized. As described 
previously, no serious injury or mortality is anticipated or authorized 
for this activity. Below, we describe how the take numbers are 
estimated.
    For acoustic impacts, generally speaking, we estimate take by 
considering: (1) acoustic thresholds above which NMFS believes the best 
available science indicates marine mammals will be behaviorally 
harassed or incur some degree of permanent hearing impairment; (2) the 
area or volume of water that will be ensonified above these levels in a 
day; (3) the density or occurrence of marine mammals within these 
ensonified areas; and, (4) the number of days of activities. We note 
that while these factors can contribute to a basic calculation to 
provide an initial prediction of potential takes, additional 
information that can qualitatively inform take estimates is also 
sometimes available (e.g., previous monitoring results or average group 
size). Below, we describe the factors considered here in more detail 
and present the 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 auditory permanent threshold shift 
(PTS) of some degree (equated to Level A harassment).
    Level B harassment is largely driven by received level, the onset 
of behavioral disturbance from anthropogenic noise exposure is also 
informed to varying degrees by other factors related to the source or 
exposure context (e.g., frequency, predictability, duty cycle, duration 
of the exposure, signal-to-noise ratio, distance to the source), the 
environment (e.g., bathymetry, other noises in the area, predators in 
the area), and the receiving animals (hearing, motivation, experience, 
demography, life stage, depth) and can be difficult to predict (e.g., 
Southall et al., 2007, 2021; Ellison

[[Page 68580]]

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) sources, 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 (masking of 
vocalization/conspecific communication, predators, prey) may result in 
changes in behavior patterns that would not otherwise occur.
    The specified activity includes the use of continuous (vibratory 
pile extraction) and impulsive (impact pile driving) sources, and 
therefore the RMS SPL thresholds of 120 and 160 dB re 1 [mu]Pa would 
typically be applicable. However, as discussed above, the Navy has 
established that the ambient noise in the project area is 126 dB re 1 
mPa (rms). Since this is louder than the 120 dB threshold for 
continuous sources, 126 dB becomes the effective threshold for Level B 
harassment for continuous sources.
    Level A harassment is described in detail in NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Version 2.0) (Technical Guidance, 2018). The Technical 
Guidance identifies dual criteria to assess auditory injury (Level A 
harassment) to five different marine mammal groups (based on hearing 
sensitivity) as a result of exposure to noise from two different types 
of sources (impulsive or non-impulsive). The Navy's specified activity 
includes the use of both impulsive (impact pile driving) and non-
impulsive (vibratory extraction) sources.
    The Level A harassment 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: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
    No project activities are expected to approach levels that may 
induce PTS or other injury, and no take by Level A harassment is 
expected or authorized.

                     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.
----------------------------------------------------------------------------------------------------------------

Ensonified Area

    Here, we describe the parameters of the specified activity used to 
estimate the ensonified area and application of related acoustic 
thresholds, including source levels and transmission loss coefficient.
    The ensonified area associated with Level A harassment is more 
technically challenging to predict due to the need to account for a 
duration component. Therefore, NMFS developed an optional User 
Spreadsheet tool to accompany the Technical Guidance that can be used 
to relatively simply predict an isopleth distance for use in 
conjunction with marine mammal density or occurrence to help predict 
potential takes. We note that because of some of the assumptions 
included in the methods underlying this optional tool, we anticipate 
that the resulting isopleth estimates are typically going to be 
overestimates of some degree, which may result in an overestimate of 
potential take by Level A harassment. However, this optional tool 
offers the best way to estimate isopleth distances when more 
sophisticated modeling methods are not available or practical. For 
stationary sources (such as pile driving and removal), the optional 
User Spreadsheet tool predicts the distance at which, if a marine 
mammal remained at that distance for the duration of the activity, it 
would be expected to incur PTS. Inputs used in the optional User 
Spreadsheet tool, and the resulting estimated isopleths, are reported 
below.

                       Table 5--Calculated Extent of Level A and Level B Harassment Zones
----------------------------------------------------------------------------------------------------------------
                                              Level A harassment zones \2\ (meters)    Level B harassment zones
                            Pile size/type & ---------------------------------------         \2\ (meters)
   Activity description       source levels                               Coastal   ----------------------------
                                   \1\         California     Harbor     bottlenose
                                               sea lions      seals       dolphins           All species
----------------------------------------------------------------------------------------------------------------
Vibratory Extraction \3\..  24-inch                   0.0          6.8          1.0  \5\ 3,525 x 1,055
                             octagonal/
                             square concrete
                             (Production)
                             (162 RMS).
                            24-inch                   0.0          2.3          0.3
                             octagonal
                             concrete (TPP)
                             \4\ (162 RMS).
Impact Driving \6\........  24-inch                   0.0         28.0          1.9  375
                             octagonal
                             concrete (TPP)
                             \4\ (188 Peak,
                             176 RMS, 166
                             SEL).

[[Page 68581]]

 
                            24-inch                   0.0         58.2          3.9
                             octagonal
                             concrete
                             (Production)
                             (188 Peak, 176
                             RMS, 166 SEL).
----------------------------------------------------------------------------------------------------------------
\1\ Sound source levels at 10 meters (m) (33 ft.) distance. Units for Peak and RMS are dB re 1 [micro]Pa. The
  unit for sound exposure level (SEL) is dB 1 [micro]Pa\2\-sec.
\2\ Level A distances are based on a site-specific model for California sea lions (Dall'Osto and Dahl, 2019) and
  a generic Practical Spreading Loss model (NMFS, 2018, 2020) for harbor seals and coastal bottlenose dolphins.
  The Level A harassment criteria are not exceeded for California sea lions based on the site-specific model
  (Dall'Osto and Dahl, 2019). Level B harassment distances are based on the site-specific model (Dall'Osto and
  Dahl, 2019). No take by Level A harassment is requested or proposed for authorization.
\3\ Assumes 20 minutes of vibratory pile extraction, Weighting Factor Adjustment of 2.5 kHz, with 5 piles/day
  for Production, and 1 pile/day for the TPP.
\4\ The TPP Piles will be installed via an impact hammer prior to the production piles, re-struck for testing
  approximately 1 week later, and then removed prior to the start of production pile driving.
\5\ The distances represent the maximum north/south and east/west distance from the pile being driven. These
  distances are represented by the green line in Figure 6-1 of the Navy's application.
\6\ Assumes 600 strikes per pile, 0.01 second single-strike duration, Weighting Factor Adjustment of 2.0 kHz,
  with 3 piles/day for Production, and 1 pile/day for the TPP.

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. In the case of the Navy's FDD 
project, monitoring results from nearby projects provide the best 
available information about marine mammal presence and abundance in the 
project area. Accordingly, for purposes of estimating density of 
species that may occur in the project area, sightings collected in the 
course of monitoring projects for work at other locations within the 
bounds of NBSD are used.
    Due to the dynamic nature and multitude of overlapping uses of the 
north and north-central San Diego Bay, a number of marine mammal 
surveys have been conducted (Merkel and Associates, Inc., 2008; 
Sorensen and Swope, 2010; Graham and Saunders 2014; Naval Facilities 
Engineering Command, Southwest (NAVFAC SW) 2018b). Based on these 
surveys California sea lions are the predominant species observed. 
However, relative to the FDD project area, only one dedicated line 
transect survey (Sorensen and Swope, 2010) surveyed an area south of 
the Coronado Bridge. During the Sorensen and Swope (2010) survey, two 
sightings of one California sea lion each were reported in the water 
adjacent to NBSD. As presented in the NBSD Pier 6 Replacement Project's 
first year's interim report (NAVFAC SW, 2022) a clearer picture of 
marine mammal activity south of the Coronado Bay Bridge was developed 
during 132 days of observations. This recent monitoring effort found 
that California sea lions were the most common species observed south 
of the Coronado Bridge (69.9 percent), but coastal bottlenose dolphins 
(29.5 percent), and to a lesser extent harbor seals (0.6 percent), were 
observed as well. The Pier 6 Replacement Project data represents the 
best available science for an area that is close to the project area 
described here. Accordingly, the application uses these prior 
observations from the immediate vicinity as a basis for assessing 
potential project impacts to California sea lions, coastal bottlenose 
dolphins, and harbor seals by leveraging the numbers provided in NAVFAC 
SW (2022).

Take Estimation

    Here, we describe how the information provided in the application 
was synthesized to produce the quantitative estimate of the take that 
informed the authorization. Changes described in Changes from the 
Proposed IHA to Final IHA above are expected to reduce the effects 
described below. However, due to the potential for further changes that 
may arise during construction, the Navy requests that the higher take 
estimates that follow below, and that were developed based on the 
construction methods and materials described in the initial 
application.
    The degree to which underwater noise propagates away from a noise 
source is dependent on a variety of factors, most notably by bathymetry 
and the presence or absence of reflective or absorptive conditions, 
including the sea surface and sediment type. The two models used to 
assess the potential distances to regulatory thresholds and to evaluate 
the potential for Level A/B harassment: (Dall'Osto and Dahl 2019; NMFS 
2018, 2020), and a Practical Spreading Loss model (PSL). Dall'Osto and 
Dahl (2019) developed site-relevant acoustic models using point sources 
at three locations (Pier 1, Pier 6 and Pier 13) along the eastern 
extent of the south-central San Diego Bay on NBSD. Due to the similar 
bathymetry and location with respect to the channel, the Pier 13 
modeling location, which is roughly 725 meters to the south of the 
Project location approximates the sound propagation profile from a 
notional source at the Mole Pier mooring wharf FFD location. Key to 
this profile is the dampening effect of sound due to the western slope 
of the dredged navigation channel, as well as channelization of sound 
to the north and south within the channel. While the Pier 13 point is 
not exactly in the project location, the model provides suitable 
representation of sound propagation in the project area with a higher 
degree of resolution than a generic PSL model would provide.
    Harbor seals and coastal bottlenose dolphins were not included in 
the site-specific modeling effort for Level A harassment isopleth 
calculations. As a result, the NMFS user spreadsheet (NMFS 2020) was 
used to determine Level A harassment zones for these species. To 
determine zones for potential Level B harassment, the site-specific 
model was used for all species because the threshold criteria for Level 
B harassment are based solely on continuous or impulsive noise source 
and are not frequency-dependent.

[[Page 68582]]



                                Table 6--Estimated Takes From Level B Harassment
----------------------------------------------------------------------------------------------------------------
                                                        Expected                                   Instances of
                                                         average      Requested \1\     Stock         take as
                      Species                          individuals    Level B take    abundance     percent of
                                                         per day                                       stock
----------------------------------------------------------------------------------------------------------------
California sea lion................................               2             118     257, 606           0.05%
Harbor seal........................................               1              59       30,968           0.19%
Coastal bottlenose dolphin.........................               1              59          453             13%
----------------------------------------------------------------------------------------------------------------
\1\ Based on 59 days of pile driving activity.

Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks, and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, NMFS 
considers two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned), and;
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations.
    The following mitigation measures are required in order to avoid 
and minimize the potential for Level A harassment and to reduce, to the 
lowest extent practicable, exposure to noise exceeding Level B 
harassment criteria. The contractor is responsible for complying with 
all the mitigation measures listed below, whereas on-site Navy 
representatives will monitor the contractor's performance and require 
corrective action or stop work, if necessary, to ensure that 
requirements are met.
    (1) Time Restriction: The Navy plans to conduct in-water pile 
extraction/installation activities only when sufficient ambient light 
is available for visual observations (generally 30 minutes after 
sunrise and up to 45 minutes before sunset); however, the Lead 
Protected Species Observer will make a final determination as to when 
to start or stop activities based on ambient lighting conditions.
    (2) General Vessel and Machinery Stoppage: For in-water activities, 
including heavy machinery activities other than pile extraction/
installation (e.g., barge movements) or when using vessels, if a marine 
mammal comes within 10 m (33 ft.), the activity must cease operations 
and/or reduce vessel speed to the minimum level required to maintain 
steerage and safe working conditions.
    (3) Pre-Construction Briefing: Prior to the start of all in-water 
pile installation or extraction activities, briefings will be conducted 
for construction supervisors and crews, the monitoring team and when 
new personnel join the work. The briefing will explain 
responsibilities, communication procedures, the marine mammal 
protocols, and operational procedures for stopping/delaying in-water 
activities.
    (4) Protected Marine Species Visual Monitoring: Marine Species 
Visual Monitoring will assess and document any effects on marine 
mammals. PSOs will visually observe the surrounding waters for marine 
mammal presence, assess any potential Level B harassment and ensure 
effective notification of any animals sighted in established shutdown 
zones.
    <bullet> Monitoring will take place from 30 minutes prior to 
initiation through 30 minutes post-completion of pile extraction/
installation activities;
    <bullet> During all observation periods, the PSOs will use 
binoculars and/or the naked eye to search continuously for protected 
marine species;
    <bullet> Shutdown zone(s) may only be declared clear, and pile 
extraction/installation started, when the entire shutdown zone is 
visible (i.e., when not obscured by a poor light, rain, fog, etc.). If 
the applicable shutdown zone is obscured by fog or poor lighting 
conditions, activity at the location will not be initiated until the 
shutdown zone is visible.
    (4) All observers shall have no other project-related tasks while 
recording data to address the following requirements:
    a. Date and time that pile extraction/installation begins or ends;
    b. Construction activities occurring during each observation 
period;
    c. Weather parameters (e.g., wind, temperature, percent cloud 
cover, and visibility);
    d. Tide stage and sea state (The Beaufort Sea State Scale will be 
used to determine sea-state);
    e. Species, numbers, and, if possible, sex and age class of marine 
mammals;
    f. Marine mammal behavior patterns observed, including bearing and 
direction of travel, and if possible, the correlation to Sound Pressure 
Levels;
    g. Distance from pile installation activities to marine mammals and 
distance of a sighted marine mammal from the observation point;
    h. Locations of all PSOs; and
    i. Other, relevant human activity in the area.
    (5) Soft Start: The use of soft-start procedures for impact pile 
driving are expected to provide additional protection to marine mammals 
by providing a warning and/or giving marine mammals a chance to leave 
the area prior to the hammer operating at full capacity.
    6. Shutdown Zones:

[[Page 68583]]



                                             Table 7--Shutdown Zones
----------------------------------------------------------------------------------------------------------------
                                                                                  Shutdown zones (meters)
                                                                          --------------------------------------
             Activity description                Pile size/type & source                               Coastal
                                                         levels             California     Harbor     bottlenose
                                                                            sea lions      seals       dolphins
----------------------------------------------------------------------------------------------------------------
Vibratory Extraction.........................  24-inch octagonal/square             10           10           10
                                                concrete (Production)
                                                (162 RMS).
                                               24-inch octagonal concrete           10           10           10
                                                (TPP) (162 RMS).
Impact Driving...............................  24-inch octagonal concrete           10           30           10
                                                (TPP) (188 Peak, 176 RMS,
                                                166 SEL).
                                               24-inch octagonal concrete           10           60           10
                                                (Production) (188 Peak,
                                                176 RMS, 166 SEL).
----------------------------------------------------------------------------------------------------------------

    <bullet> Based on the activity and species observed shutdown zones 
will be established around in-water pile extraction/installation 
activities to avoid the potential for Level A harassment of marine 
mammals.
    <bullet> One Pier-based PSO will be stationed with clear view of 
the shutdown zone(s) and will be responsible for initiating shutdowns/
delays of project activities, monitoring for animals in close proximity 
to the project site, and the collection of project-related activity 
data (i.e., pile extraction/installation start and stop times, 
shutdowns/delays);
    <bullet> Visual surveys will occur for at least 30 minutes prior to 
the start of pile extraction/installation;
    <bullet> If marine mammals covered under the IHA are present within 
the Level B harassment zone, in-water construction or demolition will 
be allowed to start without delay.
    <bullet> If a marine mammal covered in the IHA enters an applicable 
shutdown zone, all pile extraction/installation activities at that 
location shall be delayed. The animal(s) shall be allowed to remain in 
the shutdown zone (i.e., must leave of their own volition) and their 
behavior must be monitored and documented. Work will be allowed to 
start once the animal has been observed either leaving the shutdown 
area, or 15 minutes has elapsed since the last observation without re-
detection of the animal;
    <bullet> If a marine mammal covered in the IHA enters the 
applicable shutdown zone, the PSO shall direct a halt of all pile 
extraction/installation activities at that location and initiate 
mitigation. The animal(s) must be allowed to remain in the shutdown 
zone (i.e., must leave of their own volition) and their behavior must 
be monitored and documented. Work may restart once the animal has been 
observed either leaving the shutdown area, or 15 minutes has elapsed 
since the last observation without re-detection of a marine mammal;
    <bullet> If a marine mammal not covered in the IHA enters the 
applicable Level B harassment zone, all pile extraction/installation 
activities shall be halted. The animal(s) must be allowed to remain in 
the Level B harassment zone (i.e., must leave of their own volition) 
and their behavior must be monitored and documented. Work will be 
allowed to restart once the animal has been observed either leaving the 
Level B harassment zone, or 60 minutes has elapsed since the last 
observation without re-detection of the animal; and
    <bullet> In the unlikely event that environmental conditions, such 
as heavy fog, prevent the visual detection of marine mammals within the 
shutdown zone (see Table 7), in-water demolition or construction 
activities will not be initiated. If in-water demolition or 
construction activities have been initiated, and conditions deteriorate 
so that the shutdown zone is not completely visible, then activities 
will be delayed until the zone is fully visible.
    Based on our evaluation of these measures NMFS has determined that 
the required 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:
    <bullet> Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
    <bullet> Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the activity; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
    <bullet> Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
    <bullet> How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
    <bullet> Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
    <bullet> Mitigation and monitoring effectiveness.
    The Navy addresses the above requirements in depth in its NMFS-
approved Marine Species Monitoring Plan and plans to implement the 
following procedures:
    The Navy will retain independent PSOs to collect marine mammal 
sightings data, including behaviors, during site preparation in the 
pre-construction period, during all in-water workdays, through 
completion of in water construction and the demobilization of pile 
extraction/installation extraction equipment. To eliminate the 
potential for bias, all

[[Page 68584]]

marine mammal observations will be logged, regardless of proximity to 
the Level A or Level B harassment zones. The efficacy of visual 
detection depends on several factors including the PSO's ability to 
detect the animal, the environmental conditions (visibility and sea 
state), and monitoring platforms. All observers shall be trained in 
marine mammal identification and behaviors, and satisfy the following 
criteria:
    <bullet> Visual acuity in both eyes (correction is permissible) 
sufficient to discern moving targets at the water's surface with 
ability to estimate target size and distance. Use of binoculars or 
spotting scope may be necessary to correctly identify the target.
    <bullet> Advanced education in biological science, wildlife 
management, mammalogy or related field (Bachelor's degree or higher is 
preferred), or equivalent Alaska Native traditional knowledge.
    <bullet> Experience and ability to conduct field observations and 
collect data according to assigned protocols (this may include academic 
experience).
    <bullet> Experience or training in the field identification of 
marine mammals (cetaceans and pinnipeds).
    <bullet> Sufficient training, orientation or experience with vessel 
operation and pile driving operations to provide for personal safety 
during observations.
    <bullet> Writing skills sufficient to prepare a report of 
observations. Reports should include such information as the number, 
type, and location of marine mammals observed; the behavior of marine 
mammals in the area of potential sound effects during construction; 
dates and times when observations and in-water construction activities 
were conducted; dates and times when in-water construction activities 
were suspended because of marine mammals, etc.
    <bullet> Ability to communicate orally, by radio or in person, with 
project personnel to provide real time information on marine mammals 
observed in the area and necessary actions, as needed.
    General Visual Monitoring Protocols: Trained PSOs will be placed at 
the best vantage point(s) practicable (e.g., the crane barge, on shore, 
or any other suitable location) to monitor for marine mammals and 
implement shutdown/delay procedures, when applicable, by notifying the 
construction operator of a need for a work stoppage.

Marine Mammal Monitoring Protocols

    <bullet> Observation data will be recorded for any marine mammals 
within visual range of the PSO, regardless of proximity to the 
monitoring zones;
    <bullet> Up to three PSOs at up to three locations will conduct the 
marine mammal monitoring depending on the activity and size of 
monitoring zones (see Figure 1-2 of the Navy's application). All PSOs 
will communicate with each other to enhance tracking of marine mammals 
that may be moving through the area and to minimize duplicate 
observation records of the same animal by different PSOs (i.e., a re-
sighting);
    <bullet> Results of all protected marine mammal observations will 
be recorded on electronic tablet or hardcopy datasheets (see Appendix A 
for an example of a hard-copy datasheet);
    <bullet> If an injured, sick, or dead marine mammal is observed, 
procedures outlined in Section 3.0 of the Navy's application will be 
followed:
    [cir] In the event that personnel involved in the Project-related 
activities discover an injured or dead marine mammal, the Navy POC for 
the IHA shall report the incident to the Office of Protected Resources 
(OPR), NMFS, and the Regional Stranding Coordinator as soon as 
feasible;
    [cir] If the death or injury was clearly caused by the specified 
activity, the IHA-holder must immediately cease the specified 
activities until NMFS is able to review the circumstances of the 
incident and determine what, if any, additional measures are 
appropriate to ensure compliance with the terms of the IHA. The IHA-
holder must not resume their activities until notified by NMFS.
    [cir] The report will include the following information:
    [ssquf] Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    [ssquf] Species identification (if known) or description of the 
animal(s) involved;
    [ssquf] Condition of the animal(s) (including carcass condition if 
the animal is dead);
    [ssquf] Observed behavior of the animal(s), if alive;
    [ssquf] If available, photographs or video footage of the 
animal(s); and
    [ssquf] General circumstances under which the animal was 
discovered.
    [cir] In the event that an injured or dead marine mammal is 
discovered, and the Lead PSO determines that the cause of the injury or 
death is unknown and the death is relatively recent (i.e., in less than 
a moderate state of decomposition as described in the next paragraph), 
the PSO will report to the Navy POC;
    [cir] Within 24 hours, the Navy POC will report the incident to the 
NBSD Base Biologist, the NMFS OPR, and the appropriate West Coast 
Region Marine Mammal Network Stranding Coordinators as noted above;
    [cir] The report will include the same information identified 
above. Pursuant to NMFS instruction and approval, activities may 
continue while the circumstances of the incident are under review;
    [cir] In the event that an injured or dead marine mammal is 
discovered, and the Lead PSO determines that the injury or death is not 
a result of activities authorized in the IHA (i.e., previously wounded 
animal, carcass with moderate to advanced decomposition, or scavenger 
damage), the Lead PSO will report the incident to the Navy POC, who 
will report the animal(s) to the NBSD base biologist;
    [cir] The appropriate West Coast Region Marine Mammal Network 
Stranding Coordinators, as noted above, will be notified within 24 
hours of the discovery;
    [cir] The PSOs will provide photographs or video footage (if 
available) or other documentation of the stranded animal sighting to 
the Navy POC under such a case; and
    [cir] At no time should the PSO handle, or attempt to handle, a 
dead marine mammal.

Pre-Construction Monitoring

    Visual surveys will occur for at least 30 minutes prior to the 
start of pile extraction/installation and mitigation measures will be 
initiated as described above.

Monitoring Concurrent With Construction

    <bullet> If a marine mammal approaches, or appears to be 
approaching, the shutdown zone(s), the PSO who first observed the 
animal will alert the ``Command'' PSO, who will notify the construction 
crew of the animal's current status. In-water activities addressed in 
the IHA will be allowed to continue while the animal remains outside 
the shutdown zone;
    <bullet> If shutdown and/or clearance procedures would result in an 
imminent concern for human safety, then the activity will be allowed to 
continue until the safety concern is addressed. During that timeframe, 
the animal(s) will be continuously monitored, and the Navy POC will be 
notified and consulted prior to re-initiation of Project-related 
activities; and
    <bullet> Regardless of location within the Level B harassment zone, 
an initial behavior and the location of the animal(s) will be logged. 
Behaviors will be continually logged until the animal is either passed 
off to another PSO, the

[[Page 68585]]

animal is no longer visible, or it has left the Level B harassment 
zone.

Post-Activity Monitoring

    <bullet> Monitoring of all zones will continue for 30 minutes 
following completion of pile extraction/installation and drilling 
activities. These surveys will record all marine mammal observations 
following the same procedures as identified for the pre-construction 
monitoring time-period, and will focus on observing and reporting 
unusual or abnormal behaviors; and
    <bullet> A summary report of recorded observations, work stoppages 
(if any) and an assessment of (1) effectiveness of mitigation and (2) 
recommendations for adjustment to future monitoring protocols will be 
required within 90 days of project completion or expiration of an IHA.

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, this discussion of our analysis applies to all 
the species listed in Table 2, 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.
    The takes from Level B harassment would be due to potential 
behavioral disturbance such as avoidance or temporary displacement or 
temporary shift in hearing threshold. 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 Mitigation section).
    The nature of the pile driving project precludes the likelihood of 
serious injury or mortality. Take would occur within a limited, 
confined area (south-central San Diego Bay) of the stock's range. The 
duration and intensity of Level B harassment events will be minimized 
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 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 months, any 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 determination that the impacts resulting from this activity 
are not expected to adversely affect any of the species or stocks 
through effects on annual rates of recruitment or survival:
    <bullet> No serious injury or mortality is anticipated or 
authorized;
    <bullet> No important habitat areas have been identified within the 
project area;
    <bullet> For all species, San Diego Bay is a peripheral part of 
their range;
    <bullet> Among the suitable options for construction available, the 
Navy will select lower-impact techniques such as vibratory pile driving 
in lieu of impact driving, to the maximum extent practicable;
    <bullet> The Navy will adhere to standards for soft-starts when 
impact driving and shut downs for all in-water activities subject to 
work stoppage; and
    <bullet> Monitoring reports from similar work in San Diego Bay have 
documented little to no effect on individuals of the same species 
resulting from the specified activities.
    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 finds that the total marine mammal take from 
the specified 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 abundance of the three species that may be subject to 
Level B harassment from the proposed pile driving and extraction 
activities.
    These estimated takes meet the ``small numbers'' criterion given 
that total

[[Page 68586]]

requested instances of take equate to no more than 13 percent of any 
stock expected to be taken, less than benchmark of less than one-third 
of stock abundance often used to substantiate a small numbers finding. 
Comparing estimated instances of take against stock abundance for 
assessment of small numbers is a conservative approach and is likely to 
over-estimate the number of animals that may be affected by the 
activity.
    Based on the analysis contained herein of the specified 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 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.

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

Authorization

    NMFS has issued an IHA to the Navy for the incidental take of 
marine mammals due to in-water construction activities associated with 
the Floating Dry Dock Project at Naval Base San Diego in San Diego, 
California from March 1, 2024 to February 28, 2025, provided the 
previously mentioned mitigation, monitoring, and reporting requirements 
are incorporated.

    Dated: September 28, 2023.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2023-21920 Filed 10-3-23; 8:45 am]
BILLING CODE 3510-22-P