[Federal Register Volume 88, Number 86 (Thursday, May 4, 2023)]
[Notices]
[Pages 28517-28531]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-09397]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XC952]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Pile Driving Training Exercises at 
Naval Base Ventura County, Port Hueneme

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 United States Navy (Navy) to incidentally harass, by Level B 
harassment only, marine mammals during pile driving training exercises 
at Naval Base Ventura County, Port Hueneme (NBVC). The Navy's 
activities are considered military readiness activities pursuant to the 
MMPA, as amended by the National Defense Authorization Act for Fiscal 
Year 2004 (2004 NDAA).

DATES: This authorization is effective from May 1, 2023 through April 
30, 2024.

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

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are proposed or, if the taking is limited to harassment, a notice of a 
proposed incidental harassment authorization 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 2004 NDAA (Pub. L. 108-136) removed the ``small numbers'' and 
``specified geographical region'' limitations indicated above and 
amended the definition of ``harassment'' as applied to a ``military 
readiness activity.'' The NDAA also amended the process as it relates 
to military readiness activities and the incidental take authorization 
process such that ``least practicable impact'' on such species or stock 
shall include consideration of personnel safety, practicality of 
implementation, and impact on the effectiveness of the military 
readiness activity. Before making the required determination, the 
Secretary shall consult with the Department of Defense regarding 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity. The activity for 
which incidental take of marine mammals is being requested, addressed 
here, qualifies as a military readiness activity. The definitions of 
all applicable MMPA statutory terms cited above are included in the 
relevant sections below.

[[Page 28518]]

Summary of Request

    NMFS received a request from the U.S. Navy on August 18, 2021, for 
an IHA to take marine mammals incidental to pile driving training 
exercises at NBVC. NMFS provided comments on the application and the 
Navy resubmitted a revised application on May 11, 2022. On May 25, 
2022, the Navy notified NMFS of the need to update the application to 
include additional activities. NMFS received the updated application on 
October 26, 2022. NMFS provided comments on the updated application and 
received a revised application from the Navy on December 5, 2022. NMFS 
provided additional comments on the application on December 8, 2022, 
and received an updated application on January 6, 2023, which was 
deemed adequate and complete on January 12, 2023. The Navy's request is 
for take of California sea lions (Zalophus californius) and harbor 
seals (Phoca vitulina richardii) by Level B harassment only. Neither 
the Navy nor NMFS expect serious injury or mortality to result from 
this activity and, therefore, an IHA is appropriate.
    Changes were made between the publication of the notice of the 
proposed IHA and this notice of the final IHA. Specifically, two 
proposed mitigation measures were removed from the final IHA that were 
included in the notice of the proposed IHA (see Changes from the 
Proposed IHA to Final IHA for more details).

Description of Activity

    The primary mission of NBVC is to provide a home port and to 
furnish training, administrative, and logistical support for the Naval 
Construction Battalions. Naval Construction Group ONE (NCG-1) is 
planning to execute pile driving training exercises at NBVC that are 
essential to construction battalion personnel prior to deployment. The 
specific components of each exercise may vary based on the specific 
training requirements for each battalion, but could include vibratory 
and impact pile driving, temporary pier construction, and subsequent 
removal of all installed materials. These are military readiness 
activities, as defined under the National 7 Defense Authorization Act 
(NDAA) of Fiscal Year 2004 (Pub. L. 108-136).
    Up to four training exercises will take place during the 
authorization period. Each training exercise will last up to 24 days, 
and will include installation (12 days) and removal (12 days) of a 
sheet pile wall and round pile pier (see Table 1 for a summary of pile 
details and the estimated effort required for pile installation and 
removal), for a total of up to 96 days over the four training 
exercises. The sheet pile wall and pier construction/removal will occur 
during the same training evolution, but will not occur at the same 
time. The U.S. Navy is requesting an IHA for Level B harassment of 
California sea lions and harbor seals related to these activities. 
Level A harassment is not anticipated or requested. The IHA will be 
effective from May 1, 2023 through April 30, 2024.

                            Table 1--Summary of Pile Details and Estimated Effort Required for Pile Installation and Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                        Vibratory       Potential    Production rate (piles/
                                                       Number of      installation/       impact               day)
         Pile type/shape                 Size           sheets/     removal duration   strikes per ---------------------------    Days of      Days of
                                                         piles       per pile/sheet      pile, if                              installation    removal
                                                                        (minutes)         needed    Installation    Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steel Sheet.....................  24-in.............           15  10/20.............           NA             3            3             5            5
Timber Pile.....................  16-in.............           10  20/30.............         1800             2            2             5            5
H-Beam..........................  14-in.............            4  20/30.............         1800             2            2             2            2
--------------------------------------------------------------------------------------------------------------------------------------------------------
                   Project Totals                              29  7.17 hours/12       ...........  ............  ...........            12           12
                                                                    hours.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Each training event will occur at either Wharf 4 or Wharf D at 
NBVC. Wharf 4 contains two potential pile driving sites. The Wharf 4 
South site is located directly in front of the Naval Facilities 
Engineering and Expeditionary Warfare Center Dive Locker, while the 
Wharf 4 East site is located along the side of the Naval Facilities 
Engineering and Expeditionary Warfare Center Dive Locker (Figure 1). 
The Wharf D site is located near the mouth of the harbor (Figure 2). 
The Wharf 4 locations are open to the majority of the harbor, whereas 
the Wharf D location is almost entirely self-contained, with only one 
access point from the channel leading to the harbor itself. No part of 
the Navy's training exercises will occur outside of Port Hueneme Harbor 
in the Pacific Ocean.

[[Page 28519]]

[GRAPHIC] [TIFF OMITTED] TN04MY23.113

Figure 1--Action Area for Pile Driving Exercises at Wharf 4

[[Page 28520]]

[GRAPHIC] [TIFF OMITTED] TN04MY23.114

Figure 2--Action Area for Pile Driving Exercises at Wharf D
    A detailed description of the Navy's planned training exercises is 
provided in the Federal Register notice for the proposed IHA (88 FR 
15956, March 15, 2023). Since that time, no changes have been made to 
the Navy's planned training exercises. Therefore, a detailed 
description is not provided here. Please refer to that Federal Register 
notice for the description of the specific activity.

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to the Navy was 
published in the Federal Register on March 15, 2023 (88 FR 15956). 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

[[Page 28521]]

available for a 30-day public comment period.
    NMFS received no public comments.

Changes From the Proposed IHA to Final IHA

    Changes were made between the publication of the notice of the 
proposed IHA and this notice of the final IHA. Two proposed mitigation 
measures were removed from the final IHA that were included in the 
notice of the proposed IHA: (1) NMFS will approve resumes of Navy 
biologists who provide the training to lookouts, and (2) Lead lookouts 
will be selected by Navy biologists among the best performing lookouts. 
The Navy has indicated that due to the military structure of the Navy's 
planned training exercises, it is not appropriate for NMFS to approve 
resumes and for Navy civilians to assign active duty personnel as 
lookouts. Lookouts will be assigned through the proper chain of 
command. In addition, some typos were corrected and some minor 
clarifying language was added to more accurately describe the Navy's 
monitoring and reporting requirements.

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, referenced here, 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 or stocks for which take is expected and 
authorized for this action, 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 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 (e.g., Carretta et al., 2022). All values 
presented in Table 2 are the most recent available at the time of 
publication and are available in the 2021 SARs (Carretta et al., 2022) 
(available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).

                                              Table 2--Species Likely Impacted by the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                            Stock abundance Nbest,
                                                                                         ESA/MMPA status;   (CV, Nmin, most recent             Annual M/
             Common name                  Scientific name             MMPA stock          strategic (Y/N)    abundance survey) \2\     PBR       SI \3\
                                                                                                \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
    California sea lion.............  Zalophus californianus.  U.S....................  -,-, N              257,606 (N.A.;             14,011       >320
                                                                                                             233,515; 2014).
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina           California.............  -,-, N              30,968 (N.A.; 27,348;       1,641         43
                                       richardii.                                                            2012).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable (N.A.).
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.

    As indicated above, the two species (with two managed stocks) in 
Table 2 temporally and spatially co-occur with the activity to the 
degree that take is reasonably likely to occur.
    A detailed description of the species likely to be affected by the 
Navy's training exercises, 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 15956, March 15, 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

[[Page 28522]]

(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       7 Hz to 35 kHz.
 (baleen whales).
Mid-frequency (MF) cetaceans       150 Hz to 160 kHz.
 (dolphins, toothed whales,
 beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans      275 Hz to 160 kHz.
 (true porpoises, Kogia, river
 dolphins, Cephalorhynchid,
 Lagenorhynchus cruciger & L.
 australis).
Phocid pinnipeds (PW)              50 Hz to 86 kHz.
 (underwater) (true seals).
Otariid pinnipeds (OW)             60 Hz to 39 kHz.
 (underwater) (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 from underwater noise from the Navy's training 
activities have the potential to result in Level B harassment only of 
marine mammals in the vicinity of the project area. The Federal 
Register notice for the proposed IHA (88 FR 15956, March 15, 2023) 
included a discussion of the effects of anthropogenic noise on marine 
mammals and the potential effects of underwater noise from the Navy's 
training activities on marine mammals and their habitat, therefore that 
information is not repeated here. Please refer to that Federal Register 
notice (88 FR 15956, March 15, 2023) for that information. No instances 
of serious injury or mortality are expected as a result of the planned 
activities.

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized through this IHA, which will inform the negligible impact 
determinations.
    Harassment is the only type of take expected to result from these 
activities. For this military readiness activity, the MMPA defines 
``harassment'' as (i) Any act that injures or has the significant 
potential to injure a marine mammal or marine mammal stock in the wild 
(Level A harassment); or (ii) Any act that disturbs or is likely to 
disturb a marine mammal or marine mammal stock in the wild by causing 
disruption of natural behavioral patterns, including, but not limited 
to, migration, surfacing, nursing, breeding, feeding, or sheltering, to 
a point where the behavioral patterns are abandoned or significantly 
altered (Level B harassment).
    Authorized takes will be by Level B harassment only, in the form of 
disruption of behavioral patterns and/or temporary threshold shifts 
(TTS) for individual marine mammals resulting from exposure to the pile 
driving activities. Based on the nature of the activity and the 
anticipated effectiveness of the mitigation measures (i.e., shutdown 
measures) discussed in detail below in the Mitigation section, Level A 
harassment is neither anticipated nor authorized.
    As described previously, no serious injury or mortality is 
anticipated 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 
will be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur permanent threshold shifts (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

[[Page 28523]]

(e.g., Southall et al., 2007, 2021, Ellison et al., 2012). Based on 
what the available science indicates and the practical need to use a 
threshold based on a metric that is both predictable and measurable for 
most activities, NMFS typically uses a generalized acoustic threshold 
based on received level to estimate the onset of behavioral harassment. 
NMFS generally predicts that marine mammals are likely to be 
behaviorally harassed in a manner considered to be Level B harassment 
when exposed to underwater anthropogenic noise above root-mean-squared 
pressure received levels (RMS SPL) of 120 dB (referenced to 1 
micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile-
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g., 
scientific sonar) sources.
    The Navy's training activities includes the use of continuous 
(vibratory pile installation/removal) and 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). The Navy's 
training exercises includes the use of impulsive (impact pile driving) 
and non-impulsive (vibratory pile driving/removal) sources.
    These thresholds are provided in Table 4. 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 thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: L,0-pk,flat: 219    Cell 2: LE,, LF,24h: 199 dB.
                                          dB; LE,, LF,24h: 1183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: L,0-pk,flat: 230    Cell 4: LE,,MF,24h: 198 dB.
                                          dB; LE,, MF,24h: 1185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: L,0-pk,flat: 202    Cell 6: LE,,HF,24h: 173 dB.
                                          dB; LE,,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: L,0-pk.flat: 218    Cell 8: LE,,PW,24h: 201 dB.
                                          dB; LE,,PW,24h: 1185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: L,0-pk,flat: 232    Cell 10: LE,,OW,24h: 219 dB.
                                          dB; LE,,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric 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 are recommended for consideration.
Note: Peak sound pressure level (L,0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
  exposure level (LE,) has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to be
  more reflective of International Organization for Standardization standards (ISO, 2017). The subscript
  ``flat'' is being included to indicate peak sound pressure are flat weighted or unweighted within the
  generalized hearing range of marine mammals (i.e., 7 Hz to 160 kHz). 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
  weighted 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 thresholds will be exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that are used in estimating the area ensonified above the 
acoustic thresholds, including source levels and transmission loss 
coefficient.
    Sound Source Levels of Training Exercises--The intensity of pile 
driving sounds is greatly influenced by factors such as the type of 
piles, hammers, and the physical environment in which the activity 
takes place. The Navy evaluated sound source level measurements 
available for certain pile types and sizes from similar environments to 
determine reasonable source levels likely to result from the pile 
driving activities. The Navy determined that data from the California 
Department of Transportation (CALTRANS) (2020) and Naval Facilities 
Engineering Command Southwest (NAVFAC SW) (2020) provided the most 
applicable acoustic source data to use as proxy source levels for this 
action. The Navy proposed, and NFMS agrees, that source level data from 
NAVFAC SW (2020) be used as proxy source levels for vibratory driving 
of 24-inch (61 centimeter) sheet piles because this reference provided 
noise data from the site of the training exercise (i.e., data were 
recorded from Wharf 4 at NBVC). The Navy proposed, and NMFS agrees, 
that source level data from CALTRANS (2020) be used for all other pile 
sizes and installation methods as this reference provided data for the 
same or similar pile sizes and installation techniques, despite source 
levels having been recorded at different locations than the site of the 
Navy's training exercises (Table 5). Details are described below. Note 
that the source levels discussed here and provided in Table 5 represent 
the SPL referenced at a distance of 10 m from the source unless 
otherwise specified. Further, the Navy and NMFS assume that source 
levels attributed to vibratory removal of piles are equivalent or less 
than source levels attributed to the vibratory installation of pile.
    Vibratory or impact data is not available for 16-inch timber piles. 
Therefore, the Navy proposed, and NMFS agrees, that source levels for 
impact driving of 14-inch timber piles at the Ballena Bay in Alameda, 
California be used as a proxy values for impact driving 16-inch timber 
piles (CALTRANS, 2020) (Table 5). For vibratory driving of 16-inch 
timber piles, the Navy proposed, and NMFS concurs, to use source level 
data from vibratory driving of unknown sized timber piles used at the 
Norfolk Naval Station in Norfolk, Virginia (CALTRANS, 2020; Illingworth 
& Rodkin, 2015) as proxy values for the training exercises (Table 5).
    Source level data for the installation and removal of 14-inch steel 
H-beam piles is limited. The Navy proposed, and NMFS agrees, that 
source levels for 15-inch steel H-been piles installed at Ballena Isle 
Marina in Alameda, California be used as proxy values for

[[Page 28524]]

14-inch steel H-beam piles during impact driving. This decision is 
based upon the piles similar size, the use of a vertical hammer 
placement (as opposed to battering at an angle), and the similarity in 
water depths at the action sites (Table 5). The Navy also proposed, and 
NMFS agrees, that source levels for 10-inch steel H-beam piles 
installed during the San Rafeal Canal project in San Rafeal, California 
(CALTRANS, 2020) be used as proxy values for vibratory driving of 14-
inch steel H beam piles during vibratory driving (Table 5).

                      Table 5--Summary of Unattenuated In-Water Pile Driving Source Levels
----------------------------------------------------------------------------------------------------------------
                                                                                                  SELss (dB re 1
                                                                   Peak SPL (dB   RMS SPL (dB re   [micro]Pa\2\
          Pile driving method               Pile description           re 1        1 [micro]Pa)        sec)
                                                                    [micro]Pa)
----------------------------------------------------------------------------------------------------------------
Impact................................  Timber (16-in)..........             180             170             160
                                        Steel H beam (14-in)....             195             180             170
Vibratory (installation and removal)..  Timber (16-in)..........  ..............             162  ..............
                                        Steel sheet (24-in).....  ..............         \1\ 159  ..............
                                        Steel H beam (14-in)....  ..............             147  ..............
----------------------------------------------------------------------------------------------------------------
\1\ The RMS SPL for vibratory installation of 24-inch steel sheets was recorded 11 m from the source.

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

TL = B * log10 (R1/R2),

Where:

B = transmission loss coefficient (assumed to be 15)
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement.

    This formula neglects loss due to scattering and absorption, which 
is assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions including in-water structures and 
sediments. The recommended TL coefficient for most nearshore 
environments is the practical spreading value of 15. This value results 
in an expected propagation environment that will lie between spherical 
and cylindrical spreading loss conditions, which is the most 
appropriate assumption for the Navy's training exercises in the absence 
of specific modelling.
    All Level B harassment isopleths are reported in Table 7 
considering RMS source levels for impact and vibratory pile driving, 
respectively. It should be noted that based on the geography of the 
NBVC and the surrounding land masses, port infrastructure, and the 
shoreline, the Level B harassment isopleths will reach a maximum of 790 
m (2,592 ft) for Wharf 4 South, 795 m (2,601 ft) for Wharf 4 East, and 
655 m (2,149 ft) for Wharf D (See Figure 6-1, 6-2, and 6-3 in the 
Navy's application). Although it is known that there can be leakage or 
diffraction around such barriers, the assumption herein is that any 
impervious barriers will contain all pile driving noise associated with 
the Navy's planned training exercises.
    Level A Harassment Zones--The ensonified area associated with Level 
A harassment is more technically challenging to predict due to the need 
to account for a duration component. Therefore, NMFS developed an 
optional User Spreadsheet tool to accompany the Technical Guidance that 
can be used to relatively simply predict an isopleth distance for use 
in conjunction with marine mammal density or occurrence to help predict 
potential takes. We note that because of some of the assumptions 
included in the methods underlying this optional tool, we anticipate 
that the resulting isopleth estimates are typically going to be 
overestimates of some degree, which may result in an overestimate of 
potential take by Level A harassment. However, this optional tool 
offers the best way to estimate isopleth distances when more 
sophisticated modeling methods are not available or practical. For 
stationary sources, such as vibratory and impact pile driving, the 
optional User Spreadsheet tool predicts the distance at which, if a 
marine mammal remained at that distance for the duration of the 
activity, it will be expected to incur PTS. Inputs used in the optional 
User Spreadsheet tool are reported in Table 6, and the resulting 
estimated isopleths are reported in Table 7.

                                                          Table 6--NMFS User Spreadsheet Inputs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Vibratory pile driving                                      Impact pile driving
                                    --------------------------------------------------------------------------------------------------------------------
                                      16-inch timber piles    14-inch steel H beam    24-inch steel sheet    16-inch timber piles   14-inch steel H beam
--------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used...............  A.1) Non-Impul, Stat,   A.1) Non-Impul, Stat,   A.1) Non-Impul, Stat,  E.1) Impact pile       E.1) Impact pile
                                      Cont.                   Cont.                   Cont.                  driving.               driving.
Source Level (SPL).................  162 dB RMS............  147 dB RMS............  159 dB RMS...........  160 dB SEL...........  170 dB SEL.
Transmission Loss Coefficient......  15....................  15....................  15...................  15...................  15.
Weighting Factor Adjustment (kHz)..  2.5...................  2.5...................  2.5..................  2....................  2.
Time to install/remove single pile   30....................  30....................  20...................
 (minutes).
Number of strikes per pile.........  ......................  ......................  .....................  1800.................  1800.

[[Page 28525]]

 
Piles to install/remove per day....  2.....................  2.....................  3....................  2....................  2.
Distance of sound pressure level     10....................  10....................  11...................  10...................  10.
 measurement (m).
--------------------------------------------------------------------------------------------------------------------------------------------------------


           Table 7--Distances to Level A Harassment, by Hearing Group, and Level B Harassment Thresholds per Pile Type and Pile Driving Method
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                      Level Aharassment       Level A                         Level B
                                                                                        distance (m)        harassment        Level B       harassment
                                                                         Piles per ----------------------  areas (km\2\)    harassment     areas (km\2\)
                 Activity                        Pile description           day                               for all      distance (m)       for all
                                                                                        PW         OW     hearing groups    all hearing   hearing groups
                                                                                                                \1\           groups            \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Installation/Removal...........  16-inch Timber Piles........          3        4.8        0.3            <0.1       \2\ 6,310            <0.3
                                           14-inch Steel H Beam........          2        0.5          0            <0.1             631            <0.3
                                           24-inch Steel Sheet.........          3        3.4        0.2            <0.1       \2\ 4,379            <0.3
Impact Installation/Removal..............  16-inch Timber Piles........          3       36.8        2.7            <0.1              47            <0.1
                                           14-inch Steel H-Beam........          2      170.6       12.4            <0.1             216            <0.1
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Harassment areas have been truncated where appropriate to account for land masses.
\2\ The maximum harassment distances are approximately 790 m (2,592 ft) for Wharf 4 South, 795 m (2,601 ft) for Wharf 4 East, and 655 m (2,149 ft) for
  Wharf D.

Marine Mammal Occurrence and Take Estimation

    In this section we provide information about the occurrence of 
marine mammals, including density or other relevant information that 
will inform the take calculations. Here, we also describe how the 
occurrence information provided is synthesized to produce a 
quantitative estimate of the take that is reasonably likely to occur 
and which is authorized.

California Sea Lion

    No density or abundance numbers exist for California sea lions in 
the action area. Therefore, to quantitatively assess exposure of marine 
mammals to noise from pile driving conducted as part of the Navy's 
training exercises, the Navy used estimates derived from recent 
monitoring efforts to determine the number of animals potentially 
exposed in the Level A and Level B harassment zones in any one day of 
pile driving or extraction.
    NBVC biologists have been conducting opportunistic surveys of 
California sea lions hauled out at Wharf D somewhat regularly since 
2010. California sea lions have been observed regularly hauling out on 
structures (i.e., docks, barges, and boats) near Wharf D, sometimes in 
large numbers. They often crowd onto these structures, making it 
difficult for observers to determine the total number of sea lions 
present. Some of the counts at Wharf D include pinnipeds present in the 
water, which could also include harbor seals. California sea lions are 
the predominant pinniped species at Port Hueneme Harbor, so the 
assumption is that nearly all animals present will be California sea 
lions. The number of California sea lions present in the action area at 
Wharf D is variable by month and by year. The maximum number of 
California sea lions counted at Wharf D during an individual survey day 
was 342 (January 15, 2021). No other pinniped species have been 
observed at Wharf D during these surveys. While these count data 
provide a snapshot of pinniped presence in the action area, they do not 
provide rate of turnover over time of different pinnipeds present in 
the action area; nor do they provide long-term sea lion presence 
patterns.
    Since the fall of 2020, there have also been efforts to count 
pinnipeds in the water near Wharf 4; however, these monitoring efforts 
have been sporadic, taking place for an hour at a time from a boat 
launch just south of Wharf 4. Monitoring efforts have observed anywhere 
from 0 to 85 sea lions in an hour (see Figure 6-4 in the Navy's 
application). Additionally, the same individuals may have been observed 
multiple times within the survey period. Therefore, the number of 
California sea lions assumed to be present in the action area at Wharf 
4 is variable.
    Based on these data, the Navy conservatively estimates that 342 
California sea lions (i.e., the maximum number of California sea lions 
observed in the action area on a single day) may be present in the 
action area each day and be behaviorally harassed during the 96 days of 
pile driving planned as part of the Navy's training exercises. 
Therefore, the Navy requests, and NMFS authorizes, 36,960 instances of 
take by Level B harassment for California Sea Lions. No take Level A 
harassment is anticipated or authorized for California sea lions due to 
the small Level A harassment zones (Table 7) and implementation of 
shutdown zones, which will be larger than Level A harassment isopleths, 
as described below in the Mitigation section.

Harbor Seals

    No density or abundance numbers exist for harbor seals in the 
action area. Harbor seals have only been observed by NBVC biologists 
near Wharf 4; no harbor seals have been detected at Wharf D. The 
maximum number of harbor seals seen over the course of an hour of 
observation was five seals. This was 5.88 percent of the maximum number 
of California sea lions observed at Wharf D (N = 85). Therefore, to 
account for the potential for harbor seals in the action area, the Navy 
assumes that 5.88 percent of the maximum number of California sea lions 
observed animals at Wharf D (5.88 percent of 342, or 20.1 [rounded up 
to 21] animals per day) are harbor seals.
    Based on these data, the Navy conservatively estimates that 21 
harbor seals may be present in the action area each day and be 
behaviorally harassed during the 96 days of pile driving schedule as 
part of the Navy's training

[[Page 28526]]

exercises. Therefore, the Navy requests, and NMFS authorizes, 2,016 
instances of take by Level B harassment for harbor seals. No take by 
Level A harassment is anticipated or authorized for harbor seals. While 
the Level A harassment zone for impact pile driving 14-inch (36-
centimeter) steel H-beams is 170.6 m, harbor seals are considered rare 
in the action area (Department of the Navy, 2019) minimizing the 
likelihood of Level A harassment take. In addition, measures described 
below in the Mitigation section, including shutdown measures and the 
implementation of lookouts at stations where the entire Level B 
harassment zones are observable, will minimize the likelihood that 
harbor seals will be in this larger zone during impact driving of steel 
H-beams and that they will incur PTS before pile driving activities 
could be shut down. Therefore, NMFS agrees with the Navy and is not 
authorizing any takes by Level A harassment takes for harbor seals 
during the Navy's training exercises.
    In summary, the total amount of Level A harassment and Level B 
harassment authorized for each marine mammal stock is presented in 
Table 8.

            Table 8--Amount of Take as a Percentage of Stock Abundance, by Stock and Harassment Type
----------------------------------------------------------------------------------------------------------------
                                                                  Authorized take
            Species                   Stock      ------------------------------------------------   Percent of
                                                      Level A         Level B          Total           stock
----------------------------------------------------------------------------------------------------------------
California Sea Lion...........  U.S.............               0          36,960          36,960            14.3
Harbor Seal...................  California......               0           2,016           2,016            6.51
----------------------------------------------------------------------------------------------------------------

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, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    The Navy must employ the following standard mitigation measures, as 
included in the IHA:
     Conduct briefings between supervisors and trainees, the 
marine mammal monitoring team, and Navy staff prior to the start of all 
in-water pile driving activity, and when new personnel join the work, 
to ensure that responsibilities, communication procedures, marine 
mammal monitoring protocols, and operational procedures are clearly 
understood.
     During all in-water work other than pile driving (e.g., 
pile placement, boat use), in order to prevent injury from physical 
interaction with construction equipment, a shutdown zone of 10 m (33 
ft) will be implemented. If a marine mammal comes within 10 m (33 ft), 
operations shall cease and vessels shall reduce speed to the minimum 
level required to maintain steerage and safe working conditions. If 
human safety is at risk, the in-water activity will be allowed to 
continue until it is safe to stop.
     The Navy must establish shutdown zones for all for in-
water pile driving activities. The purpose of a shutdown zone is 
generally to define an area within which shutdown of activity will 
occur upon sighting of a marine mammal (or in anticipation of an animal 
entering the defined area). Shutdown zones will vary based on the type 
of pile installation/removal activity (See Table 9). Here, shutdown 
zones are larger than the calculated Level A harassment isopleths shown 
in Table 7. The placement of lookouts during all pile driving 
activities (described in detail in the Monitoring and Reporting 
section) will ensure that the entirety of all shutdown zones and Level 
A harassment zones are visible during pile installation and removal.

                         Table 9--Shutdown Zones During In-Water Pile Driving Activities
----------------------------------------------------------------------------------------------------------------
                                                                                           Distance (m)
                   Activity                             Pile description         -------------------------------
                                                                                        PW              OW
----------------------------------------------------------------------------------------------------------------
Vibratory Installation/Removal................  16-inch Timber Piles............              15              15
                                                14-inch Steel H Beam............              15              15
                                                24-inch Steel Sheet.............              15              15
Impact Installation...........................  16-inch Timber Piles............              40              40
                                                14-inch Steel H Beam............             175             175
----------------------------------------------------------------------------------------------------------------


[[Page 28527]]

     The Navy must delay or shutdown all in-water pile driving 
activities should an animal approach or enter the appropriate shutdown 
zone. The Navy may resume in-water pile driving activities after one of 
the following conditions has been met: (1) the animal is observed 
exiting the shutdown zone; (2) the animal is thought to have exited the 
shutdown zone based on a determination of its course, speed, and 
movement relative to the pile driving location; or (3) the shutdown 
zone has been clear from any additional sightings for 15 minutes.
     The Navy shall employ lookouts trained in marine mammal 
identification and behaviors to monitor marine mammal presence in the 
action area. Requirements for numbers and locations of observers will 
be based on hammer type, pile material, and Seabees training location 
as described in Section 5 of the IHA. Lookouts must track marine 
mammals observed anywhere within their visual range relative to in-
water training activities, and estimate the amount of time a marine 
mammal spends within the Level A or Level B harassment zones while pile 
driving activities are underway. The Navy must monitor the project 
area, including the Level B harassment zones, to the maximum extent 
possible based on the required number of lookouts, required monitoring 
locations, and environmental conditions. For all pile driving and 
removal activities, at least one lookout must be used.
     The placement of the lookouts during all pile driving and 
removal activities must ensure that the entire applicable shutdown 
zones are visible during all in-water pile installation and removal. 
One observer must be placed in a position to implement shutdown/delay 
procedures, when applicable, by notifying the hammer operator of a need 
for a shutdown of pile driving or removal.
     Prior to the start of pile driving or removal, the 
shutdown zone(s) must be monitored for a minimum of 30 minutes to 
ensure that they are clear of marine mammals (i.e., pre-clearance 
monitoring). Pile driving will only commence once observers have 
declared the shutdown zone(s) are clear of marine mammals. Monitoring 
must also take place for 30 minutes post-completion of pile driving.
     If in-water work ceases for more than 30 minutes, the Navy 
must conduct pre-clearance monitoring of both the Level B harassment 
zone and shutdown zone.
     Pre-start clearance monitoring must be conducted during 
periods of visibility sufficient for the lead lookout to determine that 
the shutdown zones indicated in Table 9 are clear of marine mammals. 
Pile driving may commence following 30 minutes of observation when the 
determination is made that the shutdown zones are clear of marine 
mammals.
     The Navy must use soft start techniques when impact pile 
driving. Soft start requires contractors to provide an initial set of 
three strikes at reduced energy, followed by a 30 second waiting 
period, then two subsequent reduced energy strike sets. A soft start 
must be implemented at the start of each day's impact pile driving and 
at any time following cessation of impact pile driving for a period of 
30 minutes or longer. Soft starts will not be used for vibratory pile 
installation and removal. Lookouts shall begin observing for marine 
mammals 30 minutes before ``soft start'' or in-water pile installation 
or removal begins.
     For any marine mammal species for which take by Level B 
harassment has not been requested or authorized, in-water pile 
installation/removal will shut down immediately when the animals are 
sighted.
     If take by Level B harassment reaches the authorized limit 
for an authorized species, pile installation will be stopped as these 
species approach the Level B harassment zone to avoid additional take 
of them.
    Based on our evaluation of the applicant's described measures, NMFS 
has determined that the 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 action; 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

    Monitoring must be conducted by qualified lookouts with support 
from Navy biologists, in accordance with the following:
     Navy biologists will train and certify lookouts in 
accordance with the mitigation, monitoring and reporting requirements 
of the issued IHA;
     All lookouts will maintain contact via either handheld 
communication devices or flags to signal sightings and shutdowns;
     Lookouts shall be placed at vantage points to monitor for 
marine mammals and implement shutdown/delay procedures when applicable 
by calling for the shutdown to the hammer operator;
     The Lead lookout will be located within auditory range of 
the pile driving team and will have primary responsibility for calling 
activity shutdowns;
     Lookouts shall use a hand-held global positioning device 
(GPS) device, rangefinder, visual reference points, or marker buoy to 
verify the required monitoring distance from the project site;

[[Page 28528]]

     Monitoring shall occur in all-weather until training has 
concluded for the day;
     Lookouts must scan the waters within the Level A 
harassment and Level B harassment zones using binoculars (10x42 or 
similar) and or the naked eye and make visual observations of marine 
mammals present; and
     Lookouts must record all observations of marine mammals as 
described in the Section 5 of the IHA, regardless of distance from the 
pile being driven. Lookouts shall document any behavioral reactions in 
concert with distance from piles being driven or removed.
    Lookouts must have the following additional qualifications:
     Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance; use of binoculars 
may be necessary to correctly identify the target;
     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.

Reporting

    The Navy must submit a draft marine mammal monitoring report to 
NMFS within 90 days after the completion of pile driving training 
activities, or 60 days prior to a requested date of issuance of any 
future IHAs for projects at the same location, whichever comes first. 
NMFS will provide comments within 30 days after receiving the draft 
report, and the Navy will address the comments and submit revisions 
within 30 days of receipt. If no comments are received from NMFS within 
30 days, the draft report will be considered as final.
    The draft and final marine mammal monitoring reports must be 
submitted to [email protected] and 
[email protected]. The reports shall include an overall 
description of work completed, a narrative regarding marine mammal 
sightings, and associated data sheets. Specifically, the reports must 
include:
     Dates and times (begin and end) of all marine mammal 
monitoring;
     Training activities occurring during each daily 
observation period, including the number and type of piles driven or 
removed and by what method (i.e., impact or vibratory) and the total 
equipment duration for vibratory installation and removal for each pile 
or estimated total number of strikes for each pile for impact driving;
     Lookout locations during marine mammal monitoring;
     Environmental conditions during monitoring periods (at 
beginning and end of lookout shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance;
     Description of any deviation from initial proposal in pile 
numbers, pile types, average driving times, etc.;
     Brief description of any impediments to obtaining reliable 
observations during training periods; and
     Description of any impediments to complying with the 
aforementioned mitigation measures.
    Lookouts must record all incidents of marine mammal occurrence in 
the area in which take is anticipated regardless of distance from 
activity, and shall document any behavioral reactions in concert with 
distance from piles being driven or removed. Specifically, lookouts 
must record the following:
     Name of lookout who sighted the animal(s) and lookout 
location and activity at time of sighting;
     Time of sighting;
     Identification of the animal(s) (e.g., genus/species, 
lowest possible taxonomic level, or unidentified), lookout confidence 
in identification, and the composition of the group if there is a mix 
of species;
     Distance and bearing of each marine mammal observed 
relative to the pile being driven for each sighting (if pile driving 
was occurring at time of sighting);
     Estimated number of animals (min/max/best estimate);
     Estimated number of animals by cohort (adults, juveniles, 
neonates, group composition, sex class, etc.);
     Animal's closest point of approach and estimated time 
spent within the harassment zone;
     Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as feeding or traveling), including an 
assessment of behavioral responses thought to have resulted from the 
activity (e.g., no response or changes in behavioral state such as 
ceasing feeding, changing direction, flushing, or breaching);
     Number of marine mammals detected within the harassment 
zones and shutdown zones, by species; and
     Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensued, and resulting changes in behavior of the 
animal(s), if any.

Reporting Injured or Dead Marine Mammals

    In the event that personnel involved in the activities discover an 
injured or dead marine mammal, the IHA-holder must immediately cease 
the specified activities and report the incident to the Office of 
Protected Resources (OPR) ([email protected]; 
[email protected]) and to the West Coast Regional Stranding 
Coordinator (1-866-767-6114) as soon as feasible. The incident report 
must include the following information:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and
     General circumstances under which the animal was 
discovered.
    If the death or injury was clearly caused by the specified 
activity, the Navy 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 Navy must not resume their 
activities until notified by NMFS that they can continue.

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-

[[Page 28529]]

level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any impacts or responses (e.g., intensity, duration), 
the context of any impacts or responses (e.g., critical reproductive 
time or location, foraging impacts affecting energetics), as well as 
effects on habitat, and the likely effectiveness of the mitigation. We 
also assess the number, intensity, and context of estimated takes by 
evaluating this information relative to population status. Consistent 
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338, 
September 29, 1989), the impacts from other past and ongoing 
anthropogenic activities are incorporated into this analysis via their 
impacts on the baseline (e.g., as reflected in the regulatory status of 
the species, population size and growth rate where known, ongoing 
sources of human-caused mortality, or ambient noise levels).
    To avoid repetition, the discussion of our analysis applies to both 
California sea lions and harbor seals, given that the anticipated 
effects of this activity on these different marine mammal stocks are 
expected to be similar. There is little information about the nature or 
severity of the impacts, or the size, status, or structure of any of 
these species or stocks that will lead to a different analysis for this 
activity.
    NMFS has identified key factors which may be employed to assess the 
level of analysis necessary to conclude whether potential impacts 
associated with a specified activity should be considered negligible. 
These include (but are not limited to) the type and magnitude of 
taking, the amount and importance of the available habitat for the 
species or stock that is affected, the duration of the anticipated 
effect to the species or stock, and the status of the species or stock.
    NMFS does not anticipate that serious injury or mortality will 
occur as a result of the Navy's planned activity given the nature of 
the activity, even in the absence of required mitigation. Pile driving 
activities associated with the Navy's pile driving training exercises, 
as outlined previously, have the potential to disturb or displace 
marine mammals. Specifically, the specified activities may result in 
take, in the form of Level B harassment, incidental to underwater 
sounds generated from pile driving. Potential takes could occur if 
individuals are present in zones ensonified above the thresholds for 
Level B harassment, identified above, while activities are underway. 
Level A harassment is not anticipated or authorized, as described in 
the Estimated Take section, given the construction method and the 
implementation of the planned mitigation measures, including soft start 
measures during impact pile driving and shutdown zones.
    Vibratory and impact hammers will be the primary methods of 
installation. Vibratory pile driving produces lower SPLs than impact 
pile driving and will be the predominant construction method used 
during training (Table 1). The rise time of the sound produced by 
vibratory pile driving is slower, reducing the probability and severity 
of injury. Impact pile driving produces short, sharp pulses with higher 
peak levels and much sharper rise time to reach those peaks. When 
impact pile driving is used, implementation of soft start and shutdown 
zones will significantly reduce any possibility of injury. Given 
sufficient ``notice'' through use of soft starts (for impact driving), 
marine mammals are expected to move away from a sound source prior to 
it becoming potentially injurious. The Navy will use at least one 
lookout stationed strategically to increase detectability of marine 
mammals, enabling a high rate of success in implementation of shutdowns 
to avoid injury.
    Exposures to elevated sound levels produced during pile driving and 
removal in NBVC may cause behavioral disturbance of some individuals, 
however behavioral responses of marine mammals are expected to be mild, 
short term, and temporary. The Navy's activities and associated impacts 
will occur within a limited, confined area of the stocks' range. The 
project area is concentrated within two wharfs and the Level B 
harassment zones will be truncated by land. Given that pile driving and 
removal will occur for only short durations (i.e., four training 
sessions lasting up to 24 days each) on nonconsecutive days, any 
harassment occurring will be temporary. Pinnipeds swim, dive, mill, and 
haul out in and around Port Hueneme, but there is no data regarding the 
rate of turnover over time of different pinnipeds present in the action 
are. Further, there is no information regarding long-term pinniped 
presence patterns. Due to the nature of the training exercise, we can 
presume that some individual harbor seals and California sea lions will 
be repeatedly taken. Repeated, sequential exposure to pile driving 
noise over a long duration could result in more severe impacts to 
individuals that could affect a population; however, the number of non-
consecutive pile driving days for this project means that these types 
of impacts are not anticipated.
    Effects on individuals that are taken by Level B harassment, as 
enumerated in the Estimated Take section, on the basis of reports in 
the literature as well as monitoring from other similar activities, 
will likely be limited to reactions such as increased swimming speeds, 
increased surfacing time, or decreased foraging (if such activity were 
occurring) (e.g., Thorson and Reyff, 2006). Marine mammals within the 
Level B harassment zones may not show any visual cues they are 
disturbed by activities or they could become alert, avoid the area, 
leave the area, or display other mild responses that are not 
observable, such as changes in vocalization patterns. Most likely, 
individuals will simply move away from the sound source and be 
temporarily displaced from the areas of pile driving, although even 
this reaction has been observed primarily only in association with 
impact pile driving. The pile driving activities analyzed here are 
similar to, or less impactful than, numerous other construction 
activities conducted in Southern California, which have taken place 
with no known long-term adverse consequences from behavioral harassment 
(e.g., 86 FR 73247, December 27, 2021; 87 FR 65578, October 31, 2022). 
Level B harassment will be reduced to the level of least practicable 
adverse impact through use of mitigation measures described herein and, 
if sound produced by project activities is sufficiently disturbing, 
animals are likely to simply avoid the area while the activity is 
occurring. While both California sea lions and harbor seals have been 
observed in the NVBC, they are frequently observed along the nearshore 
waters of Southern California and have been observed hauling out 
outside the mouth of Port Hueneme Harbor (Department of the Navy, 2019) 
suggesting they have available habitat outside of the NBVC to use while 
the activity is occurring. While vibratory pile driving associated with 
the project may produce sounds above ambient noise, the project site 
itself is located in an industrialized port, the entire ensonified area 
is within in the NBVC, and sounds produced by the activities are 
anticipated to quickly become indistinguishable from other background 
noise in the port as they attenuate to near ambient SPLs moving away 
from the project site. Therefore, we expect that animals disturbed by

[[Page 28530]]

project sound will simply avoid the area and use more-preferred 
habitats.
    Additionally, and as noted previously, some subset of the 
individuals that are behaviorally harassed could also simultaneously 
incur some small degree of TTS for a short duration of time. Because of 
the small degree anticipated, though, any TTS potentially incurred here 
will not be expected to adversely impact individual fitness, let alone 
annual rates of recruitment or survival.
    More generally, there are no known calving or rookery grounds 
within the project area. Because the Navy's activities could occur 
during any season, takes may occur during important feeding times. 
However, the project area represents a small portion of available 
foraging habitat and impacts on marine mammal feeding for all species 
should be minimal.
    The project also is not expected to have significant adverse 
effects on affected marine mammal habitat. The project activities will 
not modify existing marine mammal habitat for a significant amount of 
time. Impacts to the immediate substrate are anticipated, but these 
will be limited to minor, temporary suspension of sediments, which 
could impact water quality and visibility for a short amount of time 
but which will not be expected to have any effects on individual marine 
mammals. Any impacts on marine mammal prey that will occur during the 
Navy's planned activity will have, at most, short-term effects on 
foraging of individual marine mammals, and likely no effect on the 
populations of marine mammals as a whole. The activities may cause some 
fish to temporarily leave the area of disturbance, thus temporarily 
impacting marine mammal foraging opportunities in a limited portion of 
the foraging range. However, because of the short duration of the 
activities and the small area of the habitat that may be affected, the 
impacts to marine mammal habitat are not expected to cause significant 
or long-term negative consequences. Indirect effects on marine mammal 
prey during the construction are expected to be minor, and these 
effects are unlikely to cause substantial effects on marine mammals at 
the individual level, with no expected effect on annual rates of 
recruitment or survival. Overall, the area impacted by the project is 
very small compared to the available surrounding habitat, and does not 
include habitat of particular importance.
    It is unlikely that minor noise effects in a small, localized area 
of habitat will have any effect on the stocks' annual rates of 
recruitment or survival. 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 negligible impact determinations for the affected stocks of 
California sea lions and harbor seals 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;
     Take by Level A harassment of California sea lions and 
harbor seals is not anticipated or authorized;
     The Navy will implement mitigation measures including soft 
starts for impact pile driving and shutdown zones to minimize the 
numbers of marine mammals exposed to injurious levels of sound, and to 
ensure that take by Level A harassment does not occur;
     The anticipated incidents of Level B harassment consist 
of, at worst, temporary modifications in behavior or TTS that will not 
result in fitness impacts to individuals;
     The specified activity and ensonification area is very 
small relative to the overall habitat ranges of all species and does 
not include habitat areas of special significance (Biologically 
Important Areas or ESA-designated critical habitat);
     The intensity of anticipated takes by Level B harassment 
is relatively low for all stocks and will not be of a duration or 
intensity expected to result in impacts on reproduction or survival; 
and
     The presumed efficacy of the mitigation measures in 
reducing the effects of the specified activity to the level of least 
practicable adverse impact.
    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 Navy's 
activity will have a negligible impact on all affected marine mammal 
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 will 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 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 the proposed action (i.e., the issuance of an IHA) and 
alternatives 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 will 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 potential harassment of 
two marine mammal species incidental to pile driving training exercises 
at NBVC, which includes the previously explained mitigation, 
monitoring, and reporting.


[[Page 28531]]


    Dated: April 28, 2023.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2023-09397 Filed 5-3-23; 8:45 am]
BILLING CODE 3510-22-P