[Federal Register Volume 89, Number 196 (Wednesday, October 9, 2024)]
[Rules and Regulations]
[Pages 81848-81867]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-23392]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 217

[Docket No. 241003-0261]
RIN 0648-BM74


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to U.S. Navy Repair and Replacement of 
the Q8 Bulkhead at Naval Station Norfolk

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

ACTION: Final rule.

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SUMMARY: NMFS, upon request from the U.S. Navy (Navy), hereby issues 
regulations to govern the unintentional taking of marine mammals 
incidental to the Q8 Bulkhead repair and replacement project at Naval 
Station (NAVSTA) Norfolk in Norfolk, Virginia over the course of 5 
years (i.e., 2025-2029) (the Project). These regulations, which allow 
for the issuance of a Letter of Authorization (LOA) for the incidental 
take of marine mammals during the described activities and specified 
timeframes, prescribe the permissible methods of taking and other means 
of effecting the least practicable adverse impact on marine mammal 
species or stocks and their habitat, as well as requirements pertaining 
to the monitoring and reporting of such taking.

DATES: This rule is effective from January 1, 2025, through December 
31, 2029.

ADDRESSES: A copy of the Navy's application and any supporting 
documents, as well as a list of the references cited in this document, 
may be obtained online at: https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navys-construction-activities-q8-bulkhead-naval-station.
    In case of problems accessing these documents, please call the 
contact listed below.

FOR FURTHER INFORMATION CONTACT: Craig Cockrell, Office of Protected 
Resources, NMFS, (301) 427-8401 or <a href="/cdn-cgi/l/email-protection#ccafbeada5abe2afa3afa7bea9a0a08ca2a3adade2aba3ba"><span class="__cf_email__" data-cfemail="caa9b8aba3ade4a9a5a9a1b8afa6a68aa4a5ababe4ada5bc">[email protected]</span></a>.

SUPPLEMENTARY INFORMATION:

Purpose and Need for Regulatory Action

    This rule establishes a framework under the authority of the Marine 
Mammal Protection Act (MMPA) (16 U.S.C. 1361 et seq.) to allow for the 
authorization of take of marine mammals incidental to the Navy's 
construction activities related to the Project at NAVSTA Norfolk.
    We received an application from the Navy requesting 5-year 
regulations and authorization to take multiple species of marine 
mammals. Take is anticipated to occur incidental to impact and 
vibratory pile driving, by Level B harassment only. Please see 
Background below for definitions of harassment.

Legal Authority for the Action

    Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs 
the Secretary of Commerce to allow, upon request, the incidental, but 
not intentional, taking of small numbers of marine mammals by U.S. 
citizens who engage in a specified activity (other than commercial 
fishing) within a specified geographical region for up to 5 years if, 
after notice and public comment, the agency makes certain findings and 
issues regulations that set forth permissible methods of taking 
pursuant to that activity and other means of effecting the ``least 
practicable adverse impact'' on the affected species or stocks and 
their habitat (see the discussion below in the Mitigation section), as 
well as monitoring and reporting requirements. Section 101(a)(5)(A) of 
the MMPA, and the implementing regulations at 50 CFR part 216 subpart 
I, provide the legal basis for issuing this rule containing 5-year 
regulations, and for any subsequent letters of authorization (LOAs). As 
directed by this legal authority, this final rule contains mitigation, 
monitoring, and reporting requirements.

Summary of Major Provisions Within the Rule

    Following is a summary of the major provisions of this final rule 
regarding Navy construction activities. These measures include:
    <bullet> Required monitoring of the construction areas to detect 
the presence of marine mammals before beginning construction 
activities;
    <bullet> Shutdown of construction activities under certain 
circumstances to avoid injury of marine mammals; and
    <bullet> Soft start for impact pile driving to allow marine mammals 
the opportunity to leave the area prior to beginning impact pile 
driving at full power.

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions Section 101(a). 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

[[Page 81849]]

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 (Section 
101(5)(A)(i)(II)(aa)). The definitions of all applicable MMPA statutory 
terms cited above are included in the relevant sections below.

Summary of Request

    On September 14, 2023, NMFS received a request from the Navy for 
authorization to take marine mammals incidental to repair and 
replacement of the Q8 Bulkhead at NAVSTA Norfolk in Norfolk, VA. 
Following NMFS' review of the application, the Navy submitted a revised 
version on December 18, 2024 and after review of that application a 
second revised version was submitted on January 16, 2024. The 
application was deemed adequate and complete on February 23, 2024. A 
notice of receipt of the Navy's application was published in the 
Federal Register on March 14, 2024 (89 FR 18605). No comments were 
received on the application during the 30-day comment period.
    On July 3, 2024, NMFS published a notice of proposed rulemaking in 
the Federal Register (89 FR 55180). All comments were considered in 
development of this final rule (see Comments and Responses). Navy's 
request is for the take of four species by Level B harassment only. 
Neither Navy nor NMFS expect serious injury or mortality to result from 
this activity. The regulations will be valid for 5 years (2025-2029). 
No changes were made from the proposed to the final rule.

Description of the Activity

    The Navy proposes to repair and replace the Q8 bulkhead at NAVSTA 
Norfolk, that has failed in multiple locations, creating sinkholes and 
unsafe conditions. Work on the bulkhead will be conducted from Piers 12 
and 14 to restore function of this Navy dock system. Vibratory and 
impact hammers will be used for pile removal and installation. Sounds 
produced from these pile removal and installation activities may result 
in the incidental take of marine mammals, by Level B harassment only. 
Approximately 378 piles will be removed and 836 piles will be 
installed. Work will be conducted in 3 phases over 212 non-consecutive 
days to complete the pile removal and installation activities.
    A detailed description of the planned construction project is 
provided in the Federal Register notice for the proposed rule (89 FR 
55180, July 3, 2024). Since that time, no changes have been made to the 
planned activities. Therefore, a detailed description is not provided 
here. Please refer to that Federal Register notice for the description 
of the specific activity.

Comments and Responses

    NMFS' notice of proposed rulemaking was published in the Federal 
Register on July 3, 2024 (89 FR 55180). That proposed rule 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 proposed rule, 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 
rulemaking, and requested that interested persons submit relevant 
information, suggestions, and comments. This proposed rule was 
available for a 30-day public comment period.
    During the 30-day public comment period, NMFS received 2 
substantive comment submissions, from members of the public. NMFS' 
responses to the comments are provided below, and all comments are 
available online at: https://www.regulations.gov/document/NOAA-NMFS-2024-0055-0001/comment.
    Comment 1: A commenter stated that the sound propagation equation 
used by the Navy was simplistic and did not account for a variety of 
environmental factors that may affect the accuracy of the predicted 
harassment zones associated with pile driving. The comment stated that 
at a minimum both bottom composition and topography should be included 
in the acoustic modeling of the Level B harassment zones.
    Response 1: NMFS agrees with the commenter that assuming practical 
spreading loss is a simplistic approach and excludes certain 
environmental factors that may be influential on real transmission 
loss. However, NMFS disagrees with the commenter that the acoustic 
modeling is inadequate and ``undermines the predictions of Level B 
harassment.'' The assumption of practical spreading loss is an approach 
that is readily accessible to all applicants, and while it does exclude 
certain relevant factors, it has been supported by hydroacoustic 
measurements in many locations, where measured transmission loss 
coefficients typically are between 10 and 30 depending on the site, 
measurement date, activity, and metric. Further, more complex modeling 
requires detailed knowledge of the source spectra, seabed composition 
and associated acoustic parameters, and the sound speed profile, all of 
which are often not readily available and introduce their own non-
negligible uncertainty.
    In addition, the Navy is among the leaders in hydroacoustic 
measurements of pile driving activities (Illingworth and Rodkin, 2017; 
NAVFAC Southwest, 2020) and continues to contribute to the scientific 
knowledge available on this topic. A relevant example can be found in 
the NAVFAC 2017 pile driving noise measurement report (Illingworth and 
Rodkin, 2017), wherein transmission loss coefficients were measured for 
a variety of pile driving activities at JEB Little Creek NAVSTA and 
NAVSTA Norfolk. Transmission loss coefficients varied significantly by 
activity and location and ranged from 12.2 to 31.9, but were often near 
15. This shows that while practical spreading is not a perfect model, 
it is a good approximation in waters near the planned activity.
    Notably, sophisticated propagation modeling has been performed for 
pile driving of concrete, composite, and timber piles in the Norfolk 
region. The Navy has completed this transmission loss modeling and can 
be reviewed in the following document: https://media.fisheries.noaa.gov/dam-migration/nsn_pile_driving_final_loa_appendix_b_may_2020.pdf. While estimated 
transmission loss coefficients are not provided in the report, the 
depth-averaged cumulative SEL is given as a function of range in figure 
10 in the report, for the case of a constant water depth of 13 meters 
(m). This modeling scenario was included only for illustrative purposes 
but was deemed by the authors to be near the upper bound for expected 
ranges to thresholds for the study. By fitting several points from the 
unweighted curve, NMFS has determined that the best fit transmission 
loss coefficient for this model result is approximately 14.5, which 
agrees well with the practical spreading model.
    Based on the above analyses and information, NMFS is confident that 
the analysis of the harassment zones reasonably assesses the potential 
impacts to marine mammals and has not changed that analysis or the 
reliance upon such analysis in this final rule.
    Comment 2: A commenter urged NMFS to implement ``hard limits'' on 
the number of marine mammals that could be taken under an authorization 
granted to the Navy. Further, the commenter stated that if take of 
marine mammals exceeded those limits construction should be halted 
until NMFS is able to re-analyze the impacts of the project. The 
commenter also

[[Page 81850]]

urged NMFS to have a ``fair process'' for this authorization and to not 
give special exceptions to the Navy regarding their application for an 
LOA. The commenter also recommended that NMFS and the Navy consider the 
use of a sound producing device to deter marine mammals from the 
Project area in order to reduce the number of animals taken during 
construction activities.
    Response 2: NMFS agrees with the commenter that takes should be 
limited in numbers for each incidental take authorization. In this rule 
and the proposed rule the Navy and NMFS estimated takes that were 
likely to occur during the course of this project (see Estimate Take 
section). Take numbers for each marine mammal species were estimated 
for each phase of construction. The maximum annual take numbers for 
each species may not be exceeded in any given year, and the total take 
level may not be exceeded over the 5-year period of effectiveness of 
this rule.
    NMFS also agrees with the commenter that a fair process for the 
application and issuance of all incidental take authorizations should 
be adhered to. Once the application submitted by the Navy for this 
project was deemed adequate and complete, NMFS published a notice of 
receipt of the application in the Federal Register (89 FR 18605, March 
14, 2024) with a 30-day comment period for the public to review and 
comment on the contents of the application. After the comment period 
concluded, NMFS developed a proposed rule (89 FR 55180, July 3, 2024) 
to further engage the public on the analyses of the project and the 
impacts to marine mammals in the Project area. That proposed rule 
process included a 30-day comment period for the public. NMFS reviewed 
and responded comments submitted on the proposed rule and determined if 
any changes were necessary in the final rule. This process is in 
accordance with the relevant requirements of the MMPA and of the 
Administrative Procedure Act, and is applied in the same fashion to all 
applicants for incidental take authorizations.
    NMFS agrees that sound producing devices may be a useful tool for 
deterring marine mammals in certain circumstances and when warranted, 
e.g., when deterrence may prevent mortality or serious injury. This 
project will only result in behavioral disturbance (Level B harassment) 
which may result in (1) changing durations of surfacing and dives, 
number of blows per surfacing, or moving direction and/or speed; (2) 
reduced/increased vocal activities; (3) changing/cessation of certain 
behavioral activities (e.g., socializing or feeding); (4) visible 
startle response or aggressive behavior (e.g., tail/fluke slapping or 
jaw clapping); (5) avoidance of areas where sound sources are located 
(Thorson and Reyff, 2006) (see Behavioral Effects section for more 
information). Therefore, for this project NMFS disagrees with the use 
of acoustic deterrence devices since those devices would produce the 
same level of harassment as the construction activities of this 
project.

Changes From the Proposed Rule to Final Rule

    On May 3, 2024, NMFS published (89 FR 36762) and solicited public 
comment on its draft updated Technical Guidance (https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance), which includes updated thresholds and 
weighting functions to inform auditory injury estimates, and is 
intended to replace the 2018 Technical Guidance referenced above, once 
finalized. NMFS completed a basic comparative analysis based on the 
updated Technical Guidance and has updated the Level A harassment and 
shutdown zones (see Estimated Take and Mitigation). This change is 
necessary because the authorization and regulations issued under this 
rule are effective for 5 years and the updated Technical Guidance will 
be effective before this rule expires. This updated analysis did not 
change the anticipated take numbers analyzed through this rule.

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions, instead of reprinting the information. Additional 
information regarding population trends and threats may be found in 
NMFS' Stock Assessment Reports (SARs; 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 at: https://www.fisheries.noaa.gov/find-species.
    Table 3 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) (section 3 (19)(A)). While no serious injury or mortality is 
anticipated or proposed to be authorized here, PBR and annual serious 
injury and mortality from anthropogenic sources are included here as 
gross indicators of the status of the species or stocks and other 
threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS' U.S. Atlantic SARs. All values presented in table 1 are the most 
recent available at the time of publication (including from the draft 
2023 SARs) and are available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

[[Page 81851]]



                                            Table 1--Species Likely Impacted by the Specified Activities \1\
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                                                                                      ESA/MMPA status;   Stock abundance (CV,
            Common name                  Scientific name              Stock           strategic (Y/N)      Nmin, most recent        PBR      Annual M/SI
                                                                                            \2\          abundance survey) \3\                   \4\
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                                            Order Artiodactyla--Infraorder Cetacea--Mysticeti (baleen whales)
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Family Balaenopteridae (rorquals):
    Humpback whale.................  Megaptera novaeangliae  Gulf of Maine.........  -,-, N             1,396 (0, 1380, 2016).           22        12.15
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                                                  Odontoceti (toothed whales, dolphins, and porpoises)
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Family Physeteridae:
    Bottlenose dolphin.............  Tursiops truncatus....  Northern Migratory      -, -, Y            6,639 (0.41, 4,759,              48    12.2-21.5
                                                              Coastal.                                   2016).
                                                             Southern Migratory      -, -, Y            3,751 (0.6, 2,353,               24       0-18.3
                                                              Coastal.                                   2016).
                                                             Northern NC Estuarine.  -, -, N            823 (0.06, 782, 2017).          7.8       7.2-30
Family Phocoenidae (porpoises):
    Harbor porpoise................  Phocoena phocoena.....  Gulf of Maine/Bay of    -, -, N            85,765 (0.53, 56,420,           649          145
                                                              Fundy.                                     2021).
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                                                               Order Carnivora--Pinnipedia
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Family Phocidae (earless seals):
    Harbor Seal....................  Phoca vitulina........  Western North Atlantic  -, -, N            61,336 (0.08, 57,637,         1,729          339
                                                                                                         2018).
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\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
  (https://www.marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/).
\2\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
  designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or
  which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
  automatically designated under the MMPA as depleted and as a strategic stock.
\3\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports/. 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 detailed description of the species likely to be affected by the 
Navy's construction project, including brief introductions to the 
species and relevant stocks as well as available information regarding 
population trends and threats, and information regarding local 
occurrence, were provided in the Federal Register notice for the 
proposed rule (89 FR 55180, July 3, 2024); 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 NMFS' website (https://www.fisheries.noaa.gov/find-species) for 
generalized species accounts.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Not all marine mammal species have equal 
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and 
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al. 
(2007, 2019) recommended that marine mammals be divided into hearing 
groups based on directly measured (behavioral or auditory evoked 
potential techniques) or estimated hearing ranges (behavioral response 
data, anatomical modeling, etc.). Note that no direct measurements of 
hearing ability have been successfully completed for mysticetes (i.e., 
low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al. (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in table 2.

                  Table 2--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).

[[Page 81852]]

 
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.

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 proposed rule 
(89 FR 55180, July 3, 2024) included a discussion of the effects of 
anthropogenic noise on marine mammals and the potential effects of 
underwater noise from the Navy's construction on marine mammals and 
their habitat. That information and analysis is referenced in this 
final rule and is not repeated here; please refer to the proposed rule 
(89 FR 55180, July 3, 2024).

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
that may be authorized, 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) (16 U.S.C. 1362(18)(A)(i)-
(ii)).
    Authorized takes would be by Level B harassment only, in the form 
of disruption of behavioral patterns for individual marine mammals 
resulting from exposure to sounds emitted from pile driving. Based on 
the nature of the activity and the anticipated effectiveness of the 
mitigation measures (i.e., shutdown zones) discussed in detail below in 
the Mitigation section, Level A harassment is neither anticipated nor 
would be 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 permanent threshold shift (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 state of the receiving animals (e.g., 
hearing, motivation, experience, demography, life stage, depth) and can 
be difficult to predict (e.g., Southall et al., 2007, 2021, Ellison et 
al., 2012). Based on what the available science indicates and the 
practical need to use a threshold based on a metric that is both 
predictable and measurable for most activities, NMFS typically uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS generally predicts that marine 
mammals are likely to be behaviorally harassed in a manner considered 
to be Level B harassment when exposed to underwater anthropogenic noise 
above root-mean-squared pressure received levels (RMS SPL) of 120 dB 
(referenced to one micropascal (re one [mu]Pa)) for continuous (e.g., 
vibratory pile driving) and above RMS SPL 160 dB re one [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 (i.e., conspecific communication, predators, and 
prey) may result in changes in behavior patterns that would not 
otherwise occur.
    The Navy's activity includes the use of continuous (e.g., vibratory 
pile driving and removal) and impulsive (e.g., impact pile driving) 
sources, and therefore the RMS SPL thresholds of 120 and 160 dB re one 
[mu]Pa are applicable.
    The ensonified area associated with Level A harassment is more 
technically challenging to predict due to the need

[[Page 81853]]

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 impact or vibratory 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. For concurrent activities where combined impact and 
vibratory hammer scenarios shown in table 9, the estimated Level A 
harassment distances reflect the impact driving activity and the 
estimated Level B harassment distances reflect the combined vibratory 
source levels for that activity.
    On May 3, 2024, NMFS published (89 FR 36762) and solicited public 
comment on its draft updated Technical Guidance (https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance), which includes updated thresholds and 
weighting functions to inform auditory injury estimates, and is 
intended to replace the 2018 Technical Guidance referenced above, once 
finalized. The public comment period ended on June 17, 2024, and 
although the updated Technical Guidance is not final, we expect the 
updated Technical Guidance to represent the best available science once 
it is. To best ensure we have considered an appropriate estimate of 
take by Level A harassment, in consideration of the best available 
science, we have conducted basic comparative calculations using the 
draft updated Technical Guidance for the purposes of understanding the 
number of takes by Level A harassment (auditory injury) that would be 
predicted if the draft updated Technical Guidance were finalized with 
no changes. The relevant draft updated thresholds and weighting 
functions may be found in the executive summary of the draft updated 
Technical Guidance, on pages 3 and 4. We have also considered whether 
modifications to mitigation zones would be appropriate in light of the 
draft updated Technical Guidance. Based on the outcome of these 
comparisons/analyses using the draft updated Technical Guidance, NMFS 
has made changes as appropriate to the required shutdown zones 
necessary to avoid Level A harassment. These updates to the estimated 
harassment zones (see table 8 and table 9) and resulting changes to the 
required shutdown zones (see table 11 and table 12) are minor and do 
not result in any changes to the take levels as described in the 
proposed rule and analyzed through this final rule.
    These thresholds are provided in table 3 and table 4 below. The 
references, analysis, and methodology used in the development of the 
thresholds are described in NMFS' 2018 Technical Guidance and the draft 
NMFS' 2024 Technical Guidance, both of which may be accessed at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                          Table 3--Thresholds Identifying the Onset of Auditory Injury
                                                   [NMFS 2018]
----------------------------------------------------------------------------------------------------------------
                                                     PTS onset acoustic thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of one [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]Pa\2\s. In this table, thresholds are abbreviated to reflect American
  National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
  incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
  ``flat'' is included to indicate peak sound pressure should be flat weighted or unweighted within the
  generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
  the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
  and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
  be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
  it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.


                 Table 4--Updated Thresholds Identifying the Onset of Auditory Injury (AUD INJ)
                                                   [NMFS 2024]
----------------------------------------------------------------------------------------------------------------
                                                       AUD INJ Onset Thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: L0-pk,flat: 222     Cell 2: LE, LF,24h: 197 dB.
                                          dB; LE, LF,24h: 183 dB.
High-Frequency (HF) Cetaceans..........  Cell 3: L0-pk,flat: 230     Cell 4: LE, HF,24h: 201 dB.
                                          dB; LE, HF,24h: 193 dB.
Very High-Frequency (VHF) Cetaceans....  Cell 5: L0-pk,flat: 202     Cell 6: LE, VHF,24h: 181 dB.
                                          dB; LE,VHF,24h: 159 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: L0-pk,flat: 223     Cell 8: LE,PW,24h: 195 dB.
                                          dB; LE,PW,24h: 183 dB.

[[Page 81854]]

 
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: L0-pk,flat: 230     Cell 10: LE,OW,24h: 199 dB.
                                          dB; LE,OW,24h: 185 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric thresholds for impulsive sounds: Use whichever results in the largest isopleth for calculating AUD
  INJ 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 (L0-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 165 kHz). The subscript associated with cumulative sound
  exposure level thresholds indicates the designated marine mammal auditory weighting function (LF, HF, and VHF
  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.
    The sound field in the Project area is the existing background 
noise plus additional construction noise from the Project. Marine 
mammals are expected to be affected via sound generated by the primary 
components of the Project (i.e., impact pile driving and vibratory pile 
driving and removal). The maximum underwater area ensonified above the 
thresholds for individual activities of behavioral harassment 
referenced above is 93.5 square kilometers (km\2\)(36.1 miles (mi\2\)) 
and will consist of an area reaching the opposite shoreline of the 
river (see figures 6.6, 6.8, and 6.10 in the Navy's application for the 
Incidental Take Authorization for the Q8 bulkhead Project). The maximum 
(underwater) area ensonified above the thresholds for concurrent 
activities of behavioral harassment referenced above is 97.9 km\2\ 
(37.8 mi\2\) and will consist of a similar area reaching the opposite 
shoreline of the river as individual activities (see figures 6.11-6.16 
in the Navy's application). Additionally, vessel traffic and other 
commercial and industrial activities in the Project area may contribute 
to elevated background noise levels which may mask sounds produced by 
the Project.
    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 * Log<INF>10</INF> (R<INF>1</INF>/R<INF>2</INF>)

Where

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

    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. Spherical spreading occurs in a perfectly unobstructed 
(i.e., free-field) environment not limited by depth or water surface, 
resulting in a 6-dB reduction in sound level for each doubling of 
distance from the source (20*log[range]). Cylindrical spreading occurs 
in an environment in which sound propagation is bounded by the water 
surface and sea bottom, resulting in a reduction of three dB in sound 
level for each doubling of distance from the source (10*log[range]). A 
practical spreading value of 15 is often used under conditions, such as 
the Project site, where water increases with depth as the receiver 
moves away from the shoreline, resulting in an expected propagation 
environment that will lie between spherical and cylindrical spreading 
loss conditions. Practical spreading loss is assumed here.
    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. In order to calculate 
the distances to the Level A harassment and the Level B harassment 
sound thresholds for the methods and piles being used in this Project, 
the Navy and NMFS used acoustic monitoring data from other locations to 
develop proxy source levels for the various pile types, sizes, and 
methods. The Project includes vibratory and impact installation of 
prestressed concrete and composite piles and vibratory removal of 
existing concrete piles. Steel sheet piles to make up the wall of the 
bulkhead will be installed with vibratory hammers. Source levels for 
each pile size and driving method for individual activities are 
presented in table 5. For concurrent activities where two noise sources 
have overlapping sound fields, there is potential for higher sound 
levels than for non-overlapping sources because the isopleth of one 
sound source encompasses the sound source of another isopleth. In such 
instances, the sources are considered additive and combined using the 
rules of decibel addition. For addition of two simultaneous sources, 
the difference between the two sound source levels is calculated, and: 
(1) if that difference is between zero and one dB, three dB are added 
to the higher sound source level; (2) if the difference is between two 
or three dB, two dB are added to the highest sound source level; (3) if 
the difference is between four to nine dB, one dB is added to the 
highest sound source level; and (4) with differences of 10 dB or more, 
there is no addition. Source levels for each pile size and vibratory 
driving for concurrent activities are presented in table 6.

[[Page 81855]]



                      Table 5--Proxy Sound Source Levels for Pile Sizes and Driving Methods
----------------------------------------------------------------------------------------------------------------
                                                              Proxy source level
                                              --------------------------------------------------    Literature
          Pile size                Method         dB RMS re        dB SEL re       dB peak re         source
                                                 1[micro]Pa    1[micro]Pa\2\sec    1[micro]Pa
----------------------------------------------------------------------------------------------------------------
56-in sheet pile............  Vibratory......             168              N/A              N/A  Illingworth and
                                                                                                  Rodkin, 2017.
18-in concrete..............  Vibratory......             162              N/A              N/A  Caltrans, 2020.
16-in composite.............  Vibratory......             158              N/A              N/A  Illingworth and
                                                                                                  Rodkin, 2017.
18-in concrete..............  Impact.........             170              160              185  e4sciences,
                                                                                                  2023.
16-in composite.............  Impact.........             169              157              177  Illingworth and
                                                                                                  Rodkin, 2017.
----------------------------------------------------------------------------------------------------------------


                          Table 6--Proxy Sound Source Levels for Concurrent Activities
----------------------------------------------------------------------------------------------------------------
                                                             Vibratory
                   Pile size and type                       installation    Vibratory extract   Revised SL to be
                                                         source 1 [dB RMS]  source 2 [dB RMS]    used [dB RMS]
----------------------------------------------------------------------------------------------------------------
Source 1: Vibratory hammer 56-in steel sheet pile;                     168                162                169
 Source 2: Vibratory extraction of 18-in concrete pile.
Source 1: Vibratory hammer 18-in concrete pile; Source                 162                162                165
 2: Vibratory extraction of 18-in concrete pile........
Source 1: Vibratory hammer 56-in steel sheet pile;                     168                158                168
 Source 2: 16 in composite pile........................
----------------------------------------------------------------------------------------------------------------


                              Table 7--User Spreadsheet Input Parameters Used for Calculating Level A Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                             Weighting
                                             Pile size and                                    factor         Number of       Number of       Activity
             Phase (year)                 installation method      Spreadsheet tab used     adjustment      strikes per    piles per day     duration
                                                                                               (kHz)           pile                          (minutes)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Phase 1 (Year 1).....................  18-in concrete impact     E.1 Impact pile driving               2             307               6             N/A
                                        installation.
                                       18-in concrete vibratory  A.1 Vibratory pile                  2.5             N/A               6              14
                                        extraction.               driving.
                                       56-in sheet pile          A.1 Vibratory pile                  2.5             N/A               6              24
                                        vibratory installation.   driving.
Phase II (Year 2)....................  18-in concrete impact     E.1 Impact pile driving               2             499               6             N/A
                                        installation.
                                       18-in concrete vibratory  A.1 Vibratory pile                  2.5             N/A               6              26
                                        extraction.               driving.
                                       56-in sheet pile          A.1 Vibratory pile                  2.5             N/A               6              28
                                        vibratory installation.   driving.
Phase III (Year 3)...................  16-in composite impact    E.1 Impact pile driving               2             540               6             N/A
                                        installation.
                                       18-in concrete vibratory  E.1 Impact pile driving               2             540               6             N/A
                                        installation.
                                       16-in composite           A.1 Vibratory pile                  2.5             N/A               6              20
                                        vibratory extraction.     driving.
                                       56-in sheet pile          A.1 Vibratory pile                  2.5             N/A               6              38
                                        vibratory installation.   driving.
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                 Table 8--Calculated Level A and Level B Harassment Isopleths for Individual Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Level A harassment zone (m) \1\
                                                                         ----------------------------------------------------------------     Level B
               Phase (year)                           Activity                               HF (MF)-        VHF (HF)-                      harassment
                                                                           LF- cetaceans     cetaceans       cetaceans        Phocids         zone(m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Phase 1 (Year 1)..........................  18-in concrete impact            43.9 (43.6)       5.6 (1.6)     67.8 (52.3)     38.9 (23.5)            46.4
                                             installation.
                                            18-in concrete vibratory         13.5 (10.0)       5.2 (0.9)     11.0 (14.7)      17.3 (6.1)           6,310
                                             extraction.
                                            56-in sheet pile vibratory       48.4 (35.9)      18.6 (3.2)     39.5 (53.0)     62.3 (21.8)          15,849
                                             installation.
Phase II (Year 2).........................  18-in concrete impact            60.8 (60.8)       7.7 (2.2)     93.7 (72.4)     53.8 (32.5)            46.4
                                             installation.
                                            18-in concrete vibratory         20.3 (15.1)       7.8 (1.3)     16.6 (22.3)      26.2 (9.2)           6,310
                                             extraction.
                                            56-in sheet pile vibratory       53.7 (39.7)      20.6 (3.2)     43.8 (58.7)     69.1 (24.2)          15,849
                                             installation.
Phase III (Year 3)........................  16-in composite impact           40.4 (40.4)       5.1 (1.4)     62.3 (48.1)     35.8 (21.6)            39.8
                                             installation.
                                            18-in concrete impact            64.0 (64.0)       8.1 (2.3)     98.7 (76.3)     56.7 (34.3)            46.4
                                             installation.
                                            16-in composite vibratory          9.2 (6.8)       3.5 (0.6)      7.5 (10.1)      11.9 (4.2)           3,415
                                             extraction.
                                            56-in sheet pile vibratory       65.8 (48.7)      25.3 (4.3)     53.7 (72.0)     84.7 (29.6)          15,849
                                             installation.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Harassment zones shown in parentheticals are based on the 2018 technical guidance and were presented in the proposed rule.


[[Page 81856]]


                                 Table 9--Calculated Level A and Level B Harassment Isopleths for Concurrent Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Level A harassment zone (m) \1\
                                                                         ----------------------------------------------------------------     Level B
               Phase (year)                           Activity                               MF (HF)-        HF (VHF)-                      harassment
                                                                           LF- cetaceans     cetaceans       cetaceans        Phocids        zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Phase 1 (Year 1)..........................  Vibratory extract 18-in          56.4 (41.8)      21.7 (3.7)     46.1 (61.8)     72.7 (25.4)          18,478
                                             concrete piles and
                                             vibratory install 56-in
                                             steel sheet piles.
                                            Vibratory extract 18-in          43.9 (43.9)       5.6 (1.6)     67.8 (52.3)     38.9 (23.5)          18,478
                                             concrete piles; vibratory
                                             install 56-in steel sheet
                                             piles; impact install 18-in
                                             concrete piles.
Phase II (Year 2).........................  Vibratory extract 18-in          62.6 (46.3)      24.0 (4.1)     51.1 (68.5)     80.5 (28.2)          18,478
                                             concrete piles and
                                             vibratory install 56-in
                                             steel sheet piles.
                                            Vibratory install 56-in          60.8 (60.8)       7.7 (2.2)     93.7 (72.4)     53.8 (32.5)          15,849
                                             steel sheet piles and
                                             impact install 18-in
                                             concrete piles.
Phase III (Year 3)........................  Vibratory extract 18-in          65.8 (56.8)      25.3 (5.0)     53.7 (84.0)     84.7 (34.5)          18,478
                                             concrete piles and
                                             vibratory install 56-in
                                             steel sheet piles.
                                            Vibratory install 56-in          40.4 (40.4)       5.1 (1.4)     62.3 (48.1)     35.8 (21.6)          15,849
                                             steel sheet piles and
                                             impact install 16-in
                                             composite piles.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Harassment zones shown in parentheticals are based on the 2018 technical guidance and were presented in the proposed rule.

    The maximum distance to the Level A harassment threshold during 
construction will be during the vibratory driving of 56-inch (in) 
concrete piles during Phase III of individual activities (i.e., 84.7 m 
for harbor seals) and during the concurrent vibratory extraction of 18-
in concrete piles and vibratory installation of 56-in steel sheet piles 
for concurrent activities of Phase III (i.e., 84.7 m for harbor seals). 
Given these relatively small isopleths, if a marine mammal enters the 
shutdown zone during vibratory or impact pile driving it is expected 
that the construction activity will be shut down before any marine 
mammal would incur PTS. Therefore, no take by Level A harassment is 
expected during the construction activities associated with the Q8 
bulkhead. The largest calculated Level B harassment isopleth extends 
out to 18,478 m, which will result from concurrent pile driving of the 
scenarios presented in table 9. The largest Level B harassment zone of 
18,478 m is not an attainable observable distance in all directions, 
but in some areas the distance is smaller due to the zone being cut off 
by landmasses. The Level B harassment zone will be monitored to the 
maximum extent possible.

Marine Mammal Occurrence and Take Estimation

    In this section we provide information about the occurrence of 
marine mammals, including density or other relevant information which 
will inform the take calculations. We describe how the information 
provided is synthesized to produce a quantitative estimate of the take 
that is reasonably likely to occur and may be authorized.
Humpback Whale
    Humpback whales occur in the mouth of the Chesapeake Bay and 
nearshore waters of Virginia during winter and spring months. Several 
satellite tagged humpback whales were detected west of the Chesapeake 
Bay Bridge Tunnel, including two individuals with locations near NAVSTA 
Norfolk and Joint Expeditionary Base Little Creek (Aschettino et al., 
2017). Group size was not reported in these surveys; however, most 
whales detected were juveniles. Although two individuals were detected 
in the vicinity of the Project area during shipboard surveys conducted 
in 2020, there is no evidence that they lingered for multiple days 
(Aschettino, 2020). Because no density estimates are available for the 
species in this area, the Navy estimated, and NMFS concurs, that one 
potential sighting of an average size group (i.e., two individuals) 
could occur every 60 days of pile driving. Therefore, given the number 
of Project days expected in each year, NMFS will authorize a total of 
16 takes by Level B harassment of humpback whale over the 5-year 
authorization, with no more than four takes by Level B harassment in a 
given year.
    The largest Level A harassment zone for low-frequency cetaceans 
extends approximately 65.8 m from the source during concurrent 
activities for the vibratory extraction of 18-in concrete piles and 
vibratory install 56-in steel sheet piles (table 9). The Navy plans to 
shut down if a humpback whale is sighted within any of the Level A 
harassment zones for all activities. Therefore, NMFS will not authorize 
take by Level A harassment of humpback whales.
Bottlenose Dolphins
    The expected number of bottlenose dolphins in the Project area was 
estimated using inshore seasonal densities provided in Engelhaupt et 
al. (2016) from vessel line-transect surveys near NAVSTA Norfolk and 
adjacent areas near Virginia Beach, Virginia, from August 2012 through 
August 2015. This density includes sightings inshore of the Chesapeake 
Bay from NAVSTA Norfolk west to the Thimble Shoals Bridge and is the 
most representative density for the Project area. To calculate 
potential Level B harassment takes of bottlenose dolphin, NMFS 
conservatively multiplied the density of 1.38 dolphin/km\2\ (from 
Engelhaupt et al., 2016) by the largest Level B harassment isopleth for 
each activity (tables 7 and 8), and then by the number of days 
associated with that activity. For example, to calculate Level B 
harassment takes associated with work at the Q8 bulkhead in Phase I for 
the vibratory removal of 18-in concrete piles, NMFS multiplied the 
density (i.e., 1.38 dolphins/km\2\) by the Level B harassment zone for 
that activity (i.e., 43.3 km\2\) by the proportional number of pile 
driving days for that activity (i.e., 24 days) for a total of 1,437 
Level B harassment takes for that activity during Phase I. Takes by 
Level B harassment were calculated for both individual pile driving 
activities and concurrent pile driving activities, as authorized takes 
are conservatively based on the scenario that produces more takes by 
Level B harassment (table 9). Therefore, NMFS will authorize 14,191 
takes by Level B

[[Page 81857]]

harassment of bottlenose dolphin across all 5 years, with no more than 
6,168 takes in a given year.
    The largest Level A harassment zone for mid-frequency cetaceans 
extends approximately 25.3 m from the source during individual and 
concurrent activities during Phase III (table 8 and table 9). The Navy 
plans to shut down all activities if a bottlenose dolphin is sighted 
within the shutdown zones for mid-frequency cetaceans. Therefore, NMFS 
will not authorize take by Level A harassment of bottlenose dolphins.
Harbor Porpoise
    Harbor porpoises are known to occur in the coastal waters near 
Virginia Beach (Hayes et al., 2019). Density data for this species 
within the Project vicinity do not exist or were not calculated because 
sample sizes were too small to produce reliable estimates of density. 
Harbor porpoise sighting data collected by the Navy near NAVSTA Norfolk 
and Virginia Beach from 2012 to 2015 (Engelhaupt et al. 2014; 2015; 
2016) did not produce enough sightings to calculate densities. One 
group of two harbor porpoises was seen during spring 2015 (Engelhaupt 
et al. 2016). Elsewhere in their range, harbor porpoises typically 
occur in groups of two to three individuals (Carretta et al. 2001; 
Smultea et al. 2017).
    Due to there being no density estimates for the species in the 
Project area, the Navy conservatively estimated one exposure of two 
porpoises for every 60 days of pile driving. Total pile driving days 
for Phase I will be 74 days, Phase II will be 37 days, and Phase III 
will be 101 days. Takes by Level B harassment were calculated for both 
individual pile driving activities and concurrent pile driving 
activities, as authorized takes are conservatively based on the 
scenario that produced the larger exposure estimate (table 11). Using 
the above methodology, NMFS calculated an exposure estimate of eight 
incidents of take for harbor porpoises.
    NMFS does not expect any Level A harassment of harbor porpoise 
during this Project. The largest Level A harassment zone for high-
frequency cetaceans extends approximately 98.7 m from the source during 
individual activities during Phase III (table 8). The Navy plans to 
shut down all activities if a harbor porpoise is sighted within the 
shutdown zones for high-frequency cetaceans. Therefore, NMFS will not 
authorize take by Level A harassment of harbor porpoise.
Harbor Seal
    The expected number of harbor seals in the Project area was 
estimated using systematic land- and vessel-based survey data for in-
water and hauled out seals collected by the Navy at the CBBT rock armor 
and portal islands from 2014 through 2019 (Jones et al., 2020). The 
average daily seal count from the field season ranged from eight to 23 
seals, with an average of 13.6 harbor seals across all the field 
seasons.
    NMFS expects that harbor seals are likely to be present from 
November to April and, consistent with other recent projects (88 FR 
31633, May 18, 2023; 87 FR 15945, March 31, 2022; 86 FR 24340; May 6, 
2021, and 86 FR 17458; April 2, 2021), NMFS calculated take by Level B 
harassment by multiplying 13.6 seals by the maximum number of pile 
driving days expected to occur from November through April. Therefore, 
we expect the total number of takes by Level B harassment for harbor 
seals to be 2,882.
    NMFS does not expect any Level A harassment of harbor seals during 
this Project. The largest Level A harassment zone for phocids extends 
approximately 84.7 m from the source during individual and concurrent 
activities during Phase III (table 8 and table 9). The Navy plans to 
shut down all activities if a harbor porpoise is sighted within the 
shutdown zones for phocids. Therefore, NMFS will not authorize take by 
Level A harassment of harbor seals.

                               Table 10--Takes by Level B Harassment by Species and Stock in Comparison to Stock Abundance
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                              Level B         Level B
       LOA construction phase (year)                   Species              (individual     (concurrent        Total           Stock       Percentage of
                                                                            activities)     activities)                      abundance         stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Phase 1...................................  Humpback....................               2               2               2           1,396              <1
                                            Bottlenose dolphin--Northern           5,414           2,888           2,607           6,639           39.27
                                             Migratory (NM) 1 2.
                                            Bottlenose dolphin--Southern                                           2,607           3,751           69.50
                                             Migratory (SM) 1 2.
                                            Bottlenose dolphin--NC                                                   200             823           24.30
                                             Estuarine 1 2.
                                            Harbor porpoise.............               4               2               4          85,765              <1
                                            Harbor seal.................           1,006             408           1,006          61,336            1.64
Phase 2...................................  Humpback....................               2               2               2           1,396              <1
                                            Bottlenose dolphin--NM 1 2..           2,609           2,179           1,205           6,639           18.15
                                            Bottlenose dolphin--SM 1 2..                                           1,205           3,751           32.12
                                            Bottlenose dolphin--NC                                                   200             823           24.30
                                             Estuarine 1 2.
                                            Harbor porpoise.............               2               2               2          85,765              <1
                                            Harbor seal.................             503             653             653          61,336            1.06
Phase 3...................................  Humpback....................               4               2               4           1,396              <1
                                            Bottlenose dolphin--NM 1 2..           6,168           6,712           3,256           6,639           49.04
                                            Bottlenose dolphin--SM 1 2..                                           3,256           3,751           85.80
                                            Bottlenose dolphin--NC                                                   200             823           24.30
                                             Estuarine 1 2.
                                            Harbor porpoise.............               4               2               4          85,765              <1
                                            Harbor seal.................           1,236             625           1,373          61,336            2.24
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Take estimates are weighted based on the assumed percentages of population for each distinct stock, those percentages were also used to predict the
  proportion of animals present in the Project area from each stock. Please see Small Numbers section for additional information.
\2\ Assumes multiple repeated takes of the same individuals. Please see Small Numbers section for additional information.


[[Page 81858]]

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. 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 (e.g., likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned); and
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations.
    In addition to the measures described later in this section, the 
Navy will employ the following mitigation measures:
    <bullet> The Navy will conduct briefings between construction 
supervisors and crews, the marine mammal monitoring team, and Navy 
staff prior to the start of all pile driving activity and when new 
personnel join the work, to explain responsibilities, communication 
procedures, marine mammal monitoring protocol, and operational 
procedures;
    <bullet> If a marine mammal comes within 10 m of construction 
activities, including in-water heavy machinery work, operations shall 
cease and vessels shall reduce speed to the minimum level required to 
maintain steerage and safe working conditions; and
    <bullet> Pile driving activity must be halted upon observation of 
either a species for which incidental take is not authorized or a 
species for which incidental take has been authorized but the 
authorized number of takes has been met, entering or is within the 
harassment zone.
    The following mitigation measures apply to the Navy's in-water 
construction activities.
    Establishment of Shutdown Zones--The Navy will establish shutdown 
zones for all pile driving and removal activities. The purpose of a 
shutdown zone is generally to define an area within which shutdown of 
the 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 activity type and marine mammal hearing group 
(table 11 and table 12).
    Protected Species Observers (PSO)--The placement of PSOs during all 
pile driving and removal activities (described in the Monitoring and 
Reporting section) will ensure that the entire shutdown zone is 
visible. A minimum of two PSOs will be used during all activities.
    Monitoring for Level A and B Harassment--The Navy will monitor the 
Level B harassment zones (i.e., areas where SPLs are equal to or exceed 
the 160 dB rms threshold for impact pile driving, and the 120 dB rms 
threshold during vibratory pile driving and removal) to the extent 
practicable, and all of the Level A harassment zones and shutdown 
zones, during all pile driving days. Monitoring zones provide utility 
for observing by establishing monitoring protocols for areas adjacent 
to the shutdown zones. Monitoring zones enable observers to be aware of 
and communicate the presence of marine mammals in the Project area 
outside the shutdown zone and thus prepare for a potential cessation of 
activity should the animal enter the shutdown zone.
    Pre-Activity Monitoring--Prior to the start of daily in-water 
construction activity, or whenever a break in pile driving/removal of 
30 minutes or longer occurs, PSOs will observe the shutdown and 
monitoring zones for a period of 30 minutes. Pile driving may commence 
following 30 minutes of observation when the determination is made that 
the shutdown zones are clear of marine mammals. If a marine mammal is 
observed within the shutdown zones listed in table 11 or table 12, pile 
driving activity must be delayed or halted. If pile driving is delayed 
or halted due to the presence of a marine mammal, the activity may not 
commence or resume until either the animal has voluntarily exited and 
been visually confirmed beyond the shutdown zones or 15 minutes have 
passed without re-detection of the animal. If work ceases for more than 
30 minutes, the pre-activity monitoring of the shutdown zones will 
commence. A determination that the shutdown zone is clear must be made 
during a period of good visibility (i.e., the entire shutdown zone and 
surrounding waters must be visible to the naked eye).
    Soft Start--Soft start procedures are used to provide additional 
protection to marine mammals by providing warning and/or giving marine 
mammals a chance to leave the area prior to the hammer operating at 
full capacity. For impact pile driving, contractors will be required to 
provide an initial set of three strikes from the hammer at reduced 
energy, followed by a 30-second waiting period, then two subsequent 
reduced-energy strike sets. Soft starts will be implemented at the 
start of each day's impact pile driving and at any time following 
cessation of impact pile driving for a period of 30 minutes or longer.

                        Table 11--Shutdown and Monitoring Zones for Individual Activities
----------------------------------------------------------------------------------------------------------------
                                                              Shutdown zones (m) \1\
                                                 ------------------------------------------------     Level B
         Phase (year)               Activity                                         All other      monitoring
                                                   LF- cetaceans     VHF (HF)-        marine         zones all
                                                                     cetaceans        mammals     marine mammals
----------------------------------------------------------------------------------------------------------------
Phase 1 (Year 1)..............  18-in concrete           50 (50)         70 (60)         40 (30)              50
                                 impact
                                 installation.
                                18-in concrete           20 (10)         20 (20)         20 (10)           6,310
                                 vibratory
                                 extraction.
                                56-in sheet pile         50 (40)         40 (60)         60 (30)          15,850
                                 vibratory
                                 installation.
Phase II (Year 2)               18-in concrete           70 (70)        100 (80)         60 (40)              50
                                 impact
                                 installation.
                                18-in concrete           20 (20)         20 (30)         30 (10)           6,310
                                 vibratory
                                 extraction.

[[Page 81859]]

 
                                56-in sheet pile         60 (40)         50 (60)         70 (30)          15,850
                                 vibratory
                                 installation.
Phase III (Year 3)............  16-in composite          50 (50)         70 (50)         40 (30)              40
                                 impact
                                 installation.
                                18-in concrete           70 (70)        100 (80)         60 (40)              50
                                 impact
                                 installation.
                                16-in composite          10 (10)         10 (20)         20 (10)           3,415
                                 vibratory
                                 extraction.
                                56-in sheet pile         70 (50)         60 (80)         90 (30)          15,850
                                 vibratory
                                 installation.
----------------------------------------------------------------------------------------------------------------
\1\ Shutdown zones shown in parentheticals are based on the 2018 technical guidance and were presented in the
  proposed rule.


                        Table 12--Shutdown and Monitoring Zones for Concurrent Activities
----------------------------------------------------------------------------------------------------------------
                                                              Shutdown zones (m) \1\
                                                 ------------------------------------------------     Level B
         Phase (year)               Activity                                         All other      monitoring
                                                   LF- cetaceans   HF- cetaceans      marine         zones all
                                                                                      mammals     marine mammals
----------------------------------------------------------------------------------------------------------------
Phase 1 (Year 1)..............  Vibratory                60 (50)         50 (70)         80 (30)          18,480
                                 extract 18-in
                                 concrete piles
                                 and vibratory
                                 install 56-in
                                 steel sheet
                                 piles.
                                Vibratory                50 (70)         70 (90)         40 (40)          18,480
                                 extract 18-in
                                 concrete piles;
                                 vibratory
                                 install 56-in
                                 steel sheet
                                 piles; impact
                                 install 18-in
                                 concrete piles.
Phase II (Year 2).............  Vibratory                70 (50)         60 (70)         80 (30)          18,480
                                 extract 18-in
                                 concrete piles
                                 and vibratory
                                 install 56-in
                                 steel sheet
                                 piles.
                                Vibratory                70 (50)        100 (80)         60 (30)          15,850
                                 install 56-in
                                 steel sheet
                                 piles and
                                 impact install
                                 18-in concrete
                                 piles.
Phase III (Year 3)............  Vibratory                70 (50)         60 (70)         90 (30)          18,480
                                 extract 18-in
                                 concrete piles
                                 and vibratory
                                 install 56-in
                                 steel sheet
                                 piles.
                                Vibratory                60 (50)         50 (80)         40 (30)          15,850
                                 install 56-in
                                 steel sheet
                                 piles and
                                 impact install
                                 16-in composite
                                 piles.
----------------------------------------------------------------------------------------------------------------
\1\ Shutdown zones shown in parentheticals are based on the 2018 technical guidance and were presented in the
  proposed rule.

    Based on our evaluation of the applicant's mitigation measures, as 
well as other measures considered by NMFS, 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:
    <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.

Visual Monitoring

    Marine mammal monitoring during pile driving and removal must be 
conducted by qualified, NMFS approved PSOs, in accordance with the 
following:
    <bullet> PSOs must be independent of the activity contractor (e.g., 
employed by a subcontractor) and have no other assigned tasks during 
monitoring periods;
    <bullet> At least one PSO must have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization;
    <bullet> Other PSOs may substitute other relevant experience, 
education (i.e., a degree in biological science or related field), or 
training for prior experience performing the duties of a PSO during

[[Page 81860]]

construction activity pursuant to a NMFS-issued incidental take 
authorization;
    <bullet> PSOs must be approved by NMFS prior to beginning any 
activity subject to an LOA issued under this final rule; and
    <bullet> A lead observer or monitoring coordinator must be 
designated. The lead observer must have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization.
    PSOs must have the following additional qualifications:
    <bullet> Ability to conduct field observations and collect data 
according to assigned protocols;
    <bullet> Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
    <bullet> Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    <bullet> Writing skills sufficient to prepare a report of 
observations including but not limited to: (1) The number and species 
of marine mammals observed; (2) dates and times when in-water 
construction activities were conducted; (3) dates, times, and reason 
for implementation of mitigation (or why mitigation was not implemented 
when required); and (4) marine mammal behavior; and
    <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 as necessary.
    Given the configuration of the harassment zones, which vary 
depending on the pile type/size and the pile driver type (tables 9 and 
10), it is assumed that 2 PSOs will be sufficient to monitor the zones 
for impact drivers, and 3 to 4PSOs will be sufficient to monitor the 
zones for vibratory drivers given the placement of the observers in the 
vicinity of the Project area. However, additional monitors may be added 
if warranted by the level of marine mammal activity in the area. PSOs 
will be placed at the best vantage point(s) practicable (figure 1) to 
monitor for marine mammals and implement shutdown/delay procedures when 
applicable by calling for the shutdown by the pile driver operator. 
PSOs will be deployed on the Green Mile Fishing Pier during vibratory 
driving of piles when monitoring zones are exceptionally large.
    Monitoring will be conducted 30 minutes before, during, and after 
all in water construction activities. In addition, observers shall 
record all incidents of marine mammal occurrence, regardless of 
distance from activity, and shall document any behavioral reactions in 
concert with distance from piles being driven or removed. Pile driving 
activities include the time to install or remove a single pile or 
series of piles, as long as the time elapsed between uses of the pile 
driving equipment is no more than 30 minutes.
[GRAPHIC] [TIFF OMITTED] TR09OC24.013

Figure 1 Protected Species Observer Locations at NAVSTA Norfolk at 
Norfolk, Virginia

Acoustic Monitoring

    The Navy will implement in situ acoustic monitoring efforts to 
measure SPLs from in-water construction activities for pile types and 
methods that have not been previously collected at NAVSTA Norfolk 
(table 13). The Navy will collect and evaluate acoustic sound recording 
levels during pile driving activities. The Navy will collect data on 10 
percent of the number of total piles driven for each pile type. 
Hydrophones will be placed at locations 33 feet (ft) from the noise 
source and, where the potential for Level A (PTS onset) harassment 
exists, at a second representative monitoring location that is a 
distance of 20 times the depth of water at the pile location, to the 
maximum extent practicable. For the pile driving events acoustically 
measured, 100 percent of the data will be analyzed. Please see the 
Navy's

[[Page 81861]]

Acoustic Monitoring Plan and section 13.2 in the application for 
additional detail.

                             Table 13--Number of Piles for Hydroacoustic Monitoring
----------------------------------------------------------------------------------------------------------------
                                                                                                      Number
                   Pile type                      Total piles     Method of install of removal       monitored
----------------------------------------------------------------------------------------------------------------
18-in concrete................................             200  Vibratory.......................              20
18-in concrete................................             184  Impact..........................              18
56-in steel sheet.............................             547  Vibratory.......................              55
16-in composite...............................             178  Vibratory.......................              18
16-in composite...............................             105  Impact..........................              11
----------------------------------------------------------------------------------------------------------------

    Environmental data shall be collected and will include, but will 
not be limited to, the following: (1) wind speed and direction; (2) air 
temperature; (3) humidity; (4) surface water temperature; (5) water 
depth; (6) wave height; (7) weather conditions; and (8) other factors 
that could contribute to influencing underwater sound levels (e.g., 
aircrafts, boats, etc.).

Reporting

    The Navy is required to submit an annual report on all activities 
and marine mammal monitoring results to NMFS within 90 days following 
the end of each construction year. Additionally, a draft comprehensive 
5-year summary report must be submitted to NMFS within 90 days of the 
end of the Project. The annual reports will include an overall 
description of work completed, a narrative regarding marine mammal 
sightings, and associated PSO data sheets. Specifically, the report 
must include:
    <bullet> Dates and times (begin and end) of all marine mammal 
monitoring;
    <bullet> Construction activities occurring during each daily 
observation period, including: (a) how many and what type of piles were 
driven or removed and the method (i.e., impact or vibratory); and (b) 
the total duration of time for each pile (vibratory driving) or number 
of strikes for each pile (impact driving);
    <bullet> PSO locations during marine mammal monitoring; and
    <bullet> Environmental conditions during monitoring periods (at 
beginning and end of PSO shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance.
    Upon observation of a marine mammal the following information must 
be reported:
    <bullet> Name of PSO who sighted the animal(s) and PSO location and 
activity at the time of the sighting;
    <bullet> Time of the sighting;
    <bullet> Identification of the animal(s) (e.g., genus/species, 
lowest possible taxonomic level, or unidentified), PSO confidence in 
identification, and the composition of the group if there is a mix of 
species;
    <bullet> Distance and bearing of each observed marine mammal 
relative to the pile being driven or removed for each sighting;
    <bullet> Estimated number of animals (min/max/best estimate);
    <bullet> Estimated number of animals by cohort (e.g., adults, 
juveniles, neonates, group composition, etc.);
    <bullet> Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as feeding or traveling), including an 
assessment of behavioral responses thought to have resulted from the 
activity (e.g., no response or changes in behavioral state such as 
ceasing feeding, changing direction, flushing, or breaching);
    <bullet> Number of marine mammals detected within the harassment 
zones, by species; and
    <bullet> Detailed information about implementation of any 
mitigation (e.g., shutdowns and delays), a description of specified 
actions that ensured, and resulting changes in behavior of the 
animal(s), if any.
    The acoustic monitoring report must contain the informational 
elements described in the Acoustic Monitoring Plan and, at minimum, 
must include:
    <bullet> Hydrophone equipment and methods: (1) recording device, 
sampling rate, distance (m) from the pile where recordings were made; 
and (2) the depth of water and recording device(s);
    <bullet> Type and size of pile being driven, substrate type, method 
of driving during recordings (e.g., hammer model and energy), and total 
pile driving duration;
    <bullet> Whether a sound attenuation device is used and, if so, a 
detailed description of the device used and the duration of its use per 
pile;
    <bullet> For impact pile driving: (1) number of strikes and strike 
rate; (2) depth of substrate to penetrate; (3) pulse duration and mean, 
median, and maximum sound levels (dB re: one [micro]Pa): (4) root mean 
square sound pressure level (SPLrms); and (5) cumulative sound exposure 
level (SELcum), peak sound pressure level (SPLpeak), and single-strike 
sound exposure level (SELs-s); and
    <bullet> For vibratory driving/removal: (1) duration of driving per 
pile; and 2) mean, median, and maximum sound levels (dB re: one 
[micro]Pa): SPLrms, SELcum (and timeframe over which the sound is 
averaged).
    If no comments are received from NMFS within 30 days, the draft 
reports will constitute the final reports. If comments are received, a 
final report addressing NMFS' comments must be submitted within 30 days 
after receipt of comments. All PSO datasheets and/or raw sighting data 
must be submitted with the draft marine mammal report.

Reporting Injured or Dead Marine Mammals

    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the LOA 
(if issued) and the regulations (e.g., an injury, serious injury, or 
mortality) the Navy shall report the incident to Office of Protected 
Resources, NMFS, and the Greater Atlantic Region New England/Mid-
Atlantic Stranding Coordinator. The report must include the following 
information:
    <bullet> Description of the incident;
    <bullet> Environmental conditions (e.g., Beaufort sea state, 
visibility);
    <bullet> Description of all marine mammal observations in the 24 
hours preceding the incident;
    <bullet> Species identification or description of the animal(s) 
involved;
    <bullet> Fate of the animal(s); and
    <bullet> Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities will not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with the Navy to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. The Navy will not

[[Page 81862]]

be able to resume their activities until notified by NMFS.
    In the event that the Navy discovers an injured or dead marine 
mammal, and the lead PSO determines that the cause of the injury or 
death is unknown and the death is relatively recent (e.g., in less than 
a moderate state of decomposition as described in the next paragraph), 
the Navy will immediately report the incident to the Office of 
Protected Resources, NMFS, and the Greater Atlantic Region New England/
Mid-Atlantic Stranding Coordinator. The report will include the same 
information identified in the paragraph above. Activities will be able 
to continue while NMFS reviews the circumstances of the incident. NMFS 
will work with the Navy to determine whether modifications in the 
activities are appropriate.
    In the event that the Navy discovers an injured or dead marine 
mammal and the lead PSO determines that the injury or death is not 
associated with or related to the activities authorized in the LOA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), the Navy will report the incident 
to the Office of Protected Resources, NMFS, and the NMFS Greater 
Atlantic Region New England/Mid-Atlantic Stranding Coordinator, within 
24 hours of the discovery. The Navy will provide photographs, video 
footage (if available), or other documentation of the stranded animal 
sighting to NMFS and the Marine Mammal Stranding Network.

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 introductory discussion of our analysis 
applies to all the species listed in table 3, given that many of the 
anticipated effects of this Project on different marine mammal stocks 
are expected to be relatively similar in nature. Where there are 
meaningful differences between species or stocks, or groups of species, 
in anticipated individual responses to activities, impact of expected 
take on the population due to differences in population status, or 
impacts on habitat, they are described independently in the analysis 
below.
    Construction activities associated with the Project, as outlined 
previously, have the potential to disturb or displace marine mammals. 
Specifically, the specified activities may result in take, in the form 
of Level B harassment from underwater sounds generated by pile driving 
and removal. Potential takes could occur if marine mammals are present 
in zones ensonified above the thresholds for Level B harassment, 
identified above, while activities are underway.
    Level A harassment is unlikely considering the small Level A 
harassment zones (tables 9 and 10) and corresponding shutdown zones 
(tables 12 and 13) where activities will cease if animals were present 
in those zones. Also, pile driving and removal activities are of 
relatively short duration and an animal will have to remain within the 
area estimated to be ensonified above the Level A harassment threshold 
for multiple hours to incur PTS. This is highly unlikely given marine 
mammal movement throughout the area, especially for small, fast-moving 
species such as small cetaceans and pinnipeds. Therefore, NMFS is not 
proposing to authorize take by Level A harassment during any portion of 
the Navy's activities.
    The nature of activities included in the Navy's pile driving 
Project precludes the likelihood of serious injury or mortality. For 
all species and stocks, take will occur within a limited, confined area 
(i.e., immediately surrounding NAVSTA Norfolk in the Chesapeake Bay 
area) of the stock's range. Level B harassment will be reduced to the 
level of least practicable adverse impact through use of mitigation 
measures described herein. Furthermore, the number of individuals 
expected to be taken is extremely small relative to the stock abundance 
for all species.
    Effects on individuals that are taken by Level B harassment, 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, decreased foraging 
(if such activity were occurring), or avoidance (e.g., Thorson and 
Reyff 2006; Hampton Roads Connector Partners 2023; W.F. Magann 
Corporation 2023). Individual animals, even if taken multiple times, 
will most likely move away from the sound source and be temporarily 
displaced from the areas of pile driving, although even this reaction 
has been observed primarily only in association with impact pile 
driving. The pile driving activities analyzed here are similar to, or 
less impactful than, numerous other construction activities conducted 
along both Atlantic and Pacific coasts, which have taken place with no 
known long-term adverse consequences from behavioral harassment. 
Furthermore, many Projects similar to this one are also believed to 
result in multiple takes of individual animals without any documented 
long-term adverse effects. Level B harassment will be minimized through 
use of mitigation measures described herein and, if take does occur the 
impacts would be expected to be minimal, particularly as the Project is 
located on a busy waterfront with high amounts of vessel traffic and 
other ambient noise.
    An unusual mortality event (UME) has been declared for humpback 
whales in the U.S. Atlantic. However, we do not expect authorized takes 
to exacerbate or compound upon these ongoing UMEs. As noted previously, 
no injury, serious injury, or mortality is expected or authorized, and 
the impact of Level B harassment takes of humpback whale will be 
minimized through the incorporation of the mitigation measures. The UME 
does not yet provide cause for concern regarding population-level 
impacts. Despite the UME, the relevant population of humpback whales 
(the West Indies breeding population, or distinct population segment) 
remains healthy.
    The Project is also not expected to have significant adverse 
effects on affected marine mammals' habitats. The

[[Page 81863]]

Project activities will not modify existing marine mammal habitat for a 
significant amount of time. The activities may cause some fish to leave 
the area of disturbance, thus temporarily impacting marine mammals' 
foraging opportunities in a limited portion of the foraging range; 
however, because of the short duration of the activities and the 
relatively small area of the habitat that may be affected (with no 
known particular importance to marine mammals), the impacts to marine 
mammal habitat are not expected to cause significant or long-term 
negative consequences.
    In summary and as described above, the following factors primarily 
support our 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> The intensity of anticipated takes by Level B harassment 
is relatively low for all stocks;
    <bullet> The specified activity and associated ensonified areas are 
very small relative to the overall habitat ranges of all species and do 
not include habitat areas of special significance, including any 
pinniped haulouts;
    <bullet> The lack of anticipated significant or long-term negative 
effects to marine habitat;
    <bullet> The presumed efficacy of the mitigation measures in 
reducing the effects of the taking incidental to the specified 
activity; and
    <bullet> Monitoring reports from similar work in the Chesapeake Bay 
have documented little to no effect on individuals of the same species 
impacted by similar 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 monitoring and mitigation 
measures, NMFS finds that the total marine mammal take from the 
activity will have a negligible impact on all affected marine mammal 
species or stocks.

Small Numbers

    As noted previously, only take of small numbers of marine mammals 
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the maximum number of individuals 
taken in any year 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 maximum annual 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 maximum annual take NMFS authorizes for the four marine mammal 
stocks is below one-third of the estimated stock abundance for all 
species except for the western north Atlantic (WNA) southern coastal 
migratory stock and the WNA northern coastal migratory stock of 
bottlenose dolphins (see table 10).
    There are three bottlenose dolphin stocks that could occur in the 
Project area. Therefore, the largest estimated annual take by Level B 
harassment of 6,712 bottlenose dolphin will likely be split among the 
northern migratory coastal stock, the southern migratory coastal stock, 
and the northern North Carolina estuarine stock (NNCES). Based on the 
stocks' respective occurrence in the area, NMFS estimates that there 
will be no more than 200 takes from the NNCES stock during each phase 
of construction, representing 24 percent of that population, with the 
remaining takes split evenly between the northern and southern coastal 
migratory stocks. Based on the consideration of various factors as 
described below, we have determined that the number of individuals 
taken will comprise less than one-third of the best available 
population abundance estimate of either coastal migratory stock. 
Detailed descriptions of the stocks' ranges have been provided in the 
Description of Marine Mammals in the Area of Specified Activities 
section.
    Both the WNA northern migratory stock and the WNA southern 
migratory stock have expansive ranges and they are the only dolphin 
stocks thought to make broad scale, seasonal migrations in coastal 
waters of the WNA. Given the large ranges associated with these two 
stocks, it is unlikely that large segments of either stock will 
approach the Project area and enter into the Chesapeake Bay. The 
majority of both stocks are likely to be found widely dispersed across 
their respective habitat ranges and unlikely to be concentrated in or 
near the Chesapeake Bay.
    Furthermore, the Chesapeake Bay and nearby offshore waters 
represent the boundaries of the ranges of each of the two coastal 
stocks during migration. The WNA northern migratory stock is found 
during warm water months from coastal Virginia, including the 
Chesapeake Bay and Long Island, New York. The stock migrates south in 
the late summer and fall. During cold-water months, dolphins may be 
found in coastal waters from Cape Lookout, North Carolina, to the North 
Carolina/Virginia border. During January-March, the WNA southern 
migratory stock appears to move as far south as northern Florida. From 
April-June, the stock moves back north to North Carolina. During the 
warm water months of July-August, the stock is presumed to occupy the 
coastal waters north of Cape Lookout, North Carolina, to Assateague, 
Virginia, including the Chesapeake Bay. There is likely some overlap 
between the stocks during spring and fall migrations, but the extent of 
overlap is unknown.
    In summary and as described above, the following factors primarily 
support our determination regarding the incidental take of small 
numbers of the affected stocks of a species or stock:
    <bullet> The maximum annual take of marine mammal stocks for 
authorization comprises less than three percent of any stock abundance 
(with the exception of the three bottlenose dolphin stocks);
    <bullet> Potential bottlenose dolphin takes in the Project area are 
likely to be allocated among three distinct stocks;
    <bullet> Bottlenose dolphin stocks in the Project area have 
extensive ranges and it will be unlikely to find a high percentage of 
the individuals of any one stock concentrated in a relatively small 
area such as the Project area or the Chesapeake Bay;
    <bullet> The Chesapeake Bay represents the migratory boundary for 
each of the specified dolphin stocks and it will be unlikely to find a 
high percentage of any stock concentrated at such boundaries; and
    <bullet> Many of the takes will likely be repeats of the same 
animals, including from a resident population of the Chesapeake Bay.
    Based on the analysis contained herein of the activity (including 
the mitigation and monitoring measures) and the anticipated take of 
marine mammals, NMFS finds that small numbers of marine mammals will be 
taken relative to the population size of the affected species or 
stocks.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
determined that the total taking of affected species or stocks will not 
have an unmitigable

[[Page 81864]]

adverse impact on the availability of such species or stocks for taking 
for subsistence purposes.

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 action (i.e., the promulgation of regulations and 
subsequent issuance of incidental take authorization) with respect to 
potential impacts on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for NOAA 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 action 
qualifies to be categorically excluded from further review under NEPA.

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 NMFS authorizes 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.

Classification

    Pursuant to the procedures established to implement Executive Order 
12866, the Office of Management and Budget has determined that this 
rule is not significant.
    Pursuant to section 605(b) of the Regulatory Flexibility Act (RFA), 
the Chief Counsel for Regulation of the Department of Commerce 
certified to the Chief Counsel for Advocacy of the Small Business 
Administration at the proposed rule stage that this action will not 
have a significant economic impact on a substantial number of small 
entities. The Navy is the sole entity that will be subject to the 
requirements in these regulations, and the Navy is not a small 
governmental jurisdiction, small organization, or small business, as 
defined by the RFA. No comments were received regarding this 
certification or on the economic impacts of the rule more generally. As 
a result, a regulatory flexibility analysis is not required and none 
has been prepared.
    This rule does not contain a collection-of-information requirement 
subject to the provisions of the Paperwork Reduction Act because the 
applicant is a Federal agency.

List of Subjects in 50 CFR 217

    Acoustics, Administrative practice and procedure, Construction, 
Endangered and threatened species, Marine mammals, Mitigation and 
Monitoring requirements, Reporting requirements, Wildlife.

    Dated: October 4, 2024.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.

    For reasons set forth in the preamble, NMFS amends 50 CFR part 217 
as follows:

PART 217--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE 
MAMMALS

0
1. The authority citation for part 217 continues to read as follows:

    Authority:  16 U.S.C. 1361 et seq., unless otherwise noted.

0
2. Add subpart X to read as follows
Subpart X--Taking and Importing Marine Mammals Incidental to Navy 
Construction of the Q8 Bulkhead Repair and Replacement Project at Naval 
Station Norfolk at Norfolk, Virginia
Sec.
217.230 Specified activity and geographical region.
217.231 Effective dates.
217.232 Permissible methods of taking.
217.233 Prohibitions.
217.234 Mitigation requirements.
217.235 Requirements for monitoring and reporting.
217.236 Letters of Authorization.
217.237 Renewals and modifications of Letters of Authorization.

Subpart X--Taking and Importing Marine Mammals Incidental to Navy 
Construction of the Q8 Bulkhead Repair and Replacement Project at 
Naval Station Norfolk at Norfolk, Virginia


Sec.  217.230  Specified activity and geographical region.

    (a) Regulations in this subpart apply only to the U.S. Navy (Navy) 
and those persons it authorizes or funds to conduct activities on its 
behalf for the taking of marine mammals that occurs in the areas 
outlined in paragraph (b) of this section and that occurs incidental to 
construction activities related to the repair and replacement of the Q8 
bulkhead at Naval Station Norfolk at Norfolk, Virginia.
    (b) The taking of marine mammals by the Navy may be authorized in a 
Letter of Authorization (LOA) only if it occurs at Naval Station 
Norfolk, Norfolk, Virginia.


Sec.  217.231  Effective dates.

    Regulations under this subpart are effective from January 1, 2025, 
through December 31, 2029.


Sec.  217.232  Permissible methods of taking.

    Under an LOA issued pursuant to Sec. Sec.  216.106 of this chapter 
and 217.236, the Holder of the LOA (hereinafter ``Navy'') may 
incidentally, but not intentionally, take marine mammals within the 
area described in Sec.  217.230(b) by harassment associated with 
construction activities related to the repair and replacement of the Q8 
bulkhead, provided the activity is in compliance with all terms, 
conditions, and requirements of the regulations in this subpart and the 
applicable LOA.


Sec.  217.233  Prohibitions.

    (a) Except for the takings contemplated in Sec.  217.232 and 
authorized by a LOA issued under Sec. Sec.  216.106 of this chapter and 
217.236, it is unlawful for any person to do any of the following in 
connection with the activities described in Sec.  217.230:
    (1) Violate, or fail to comply with, the terms, conditions, and 
requirements of this subpart or a LOA issued under Sec. Sec.  216.106 
of this chapter and 217.236;
    (2) Take any marine mammal not specified in such LOA;
    (3) Take any marine mammal specified in such LOA in any manner 
other than as specified;
    (4) Take a marine mammal specified in such LOA after NMFS 
determines such taking results in more than a negligible impact on the 
species or stocks of such marine mammal; or
    (5) Take a marine mammal specified in such LOA after NMFS 
determined such taking results in an unmitigable adverse impact on the 
species or stock of such marine mammal for taking for subsistence uses.
    (b) [Reserved]


Sec.  217.234  Mitigation requirements.

    (a) When conducting the activities identified in Sec.  217.230(a), 
the mitigation measures contained in this subpart and

[[Page 81865]]

any LOA issued under Sec. Sec.  216.106 of this chapter and 217.236 
must be implemented by the Navy. These mitigation measures include:
    (1) A copy of any issued LOA must be in the possession of the Navy, 
supervisory construction personnel, lead protected species observers 
(PSO), and any other relevant designees of the Navy operating under the 
authority of the LOA at all times that activities subject to the LOA 
are being conducted;
    (2) The Navy must ensure that construction supervisors and crews, 
the monitoring team, and relevant Navy staff are trained prior to the 
start of activities subject to any issued LOA, so that 
responsibilities, communication procedures, monitoring protocols, and 
operational procedures are clearly understood. New personnel joining 
during the Project must be trained prior to commencing work;
    (3) The Navy, construction supervisors and crews, and relevant Navy 
staff must avoid direct physical interaction with marine mammals during 
construction activity. If a marine mammal comes within 10 meters (m) of 
such activity, operations must cease and vessels must reduce speed to 
the minimum level required to maintain steerage and safe working 
conditions, as necessary to avoid direct physical interaction;
    (4) The Navy must employ PSOs and establish monitoring locations as 
described in the NMFS-approved Marine Mammal Monitoring Plan. The Navy 
must monitor the Project area to the maximum extent possible based on 
the required number of PSOs, required monitoring locations, and 
environmental conditions;
    (5) For all pile driving activities, the Navy shall implement 
shutdown zones with radial distances as identified in a LOA issued 
under Sec.  217.236. If a marine mammal is observed entering or within 
the shutdown zone, such operations must be delayed or halted.
    (6) Monitoring must take place from 30 minutes prior to initiation 
of a pile driving activity (i.e., pre-start clearance monitoring) 
through 30 minutes post-completion of a pile driving activity.
    (7) Pre-start clearance monitoring must be conducted during periods 
of visibility sufficient for the lead PSO to determine that the 
shutdown zones 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.
    (8) If a marine mammal is observed entering or within the shutdown 
zones, pile driving activity must be delayed or halted.
    (9) If pile driving is delayed or halted due to the presence of a 
marine mammal, the activity may not commence or resume until either the 
animal has voluntarily exited and been visually confirmed beyond the 
shutdown zone or 15 minutes have passed without re-detection of the 
animal.
    (10) Pile driving activity must be halted upon observation of 
either a species for which incidental take is not authorized or a 
species for which incidental take has been authorized but the 
authorized number of takes has been met, entering or within the 
harassment zone.
    (11) The Navy must use soft start techniques when impact pile 
driving. Soft start requires contractors to provide an initial set of 
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.
    (b) [Reserved]


Sec.  217.235  Requirements for monitoring and reporting.

    (a) The Navy shall submit a Marine Mammal Monitoring Plan to NMFS 
for approval in advance of construction. Marine mammal monitoring must 
be conducted in accordance with the conditions in this section and the 
NMFS-approved Marine Mammal Monitoring Plan.
    (b) Monitoring must be conducted by qualified, NMFS-approved PSOs, 
in accordance with the following conditions:
    (1) PSOs must be independent of the activity contractor (e.g., 
employed by a subcontractor) and have no other assigned tasks during 
monitoring periods;
    (2) At least one PSO must have prior experience performing the 
duties of an observer during construction activity pursuant to a NMFS-
issued incidental take authorization;
    (3) Other observers may substitute other relevant experience, 
education (i.e., degree in biological science or related field), or 
training for prior experience performing the duties of an observer 
during construction activity pursuant to a NMFS-issued incidental take 
authorization;
    (4) One observer must be designated as lead observer or monitoring 
coordinator. The lead observer must have prior experience performing 
the duties of a PSO during construction activity pursuant to a NMFS-
issued incidental take authorization;
    (5) Observers must be approved by NMFS prior to beginning any 
activity subject to any issued LOA;
    (6) For all pile driving activities, a minimum of two observers 
shall be stationed at the best vantage points practicable. One of these 
observers must be positioned to monitor for marine mammals and 
implement shutdown/delay procedures;
    (7) The Navy shall monitor the harassment zones to the maximum 
extent practicable and the entire shutdown zones. The Navy shall 
monitor at least a portion of the Level B harassment zone on all pile 
driving days;
    (8) The Navy shall conduct hydroacoustic data collection in 
accordance with an Acoustic Monitoring Plan that must be approved by 
NMFS in advance of construction;
    (9) The shutdown/monitoring zones may be modified with NMFS' 
approval following NMFS' acceptance of an acoustic monitoring report;
    (10) The Navy must submit a draft monitoring report to NMFS within 
90 calendar days of the completion of each construction year. A draft 
comprehensive five-year summary report must also be submitted to NMFS 
within 90 days of the end of the Project. The reports must detail the 
monitoring protocol and summarize the data recorded during monitoring. 
Final annual reports and the final comprehensive report must be 
prepared and submitted within 30 days following resolution of any NMFS 
comments on the draft report. If no comments are received from NMFS 
within 30 days of receipt of the draft report, the report must be 
considered final. If comments are received, a final report addressing 
NMFS comments must be submitted within 30 days after receipt of 
comments. The reports must at minimum contain the informational 
elements described below (as well as any additional information 
described in the Marine Mammal Monitoring Plan), including:
    (i) Dates and times (begin and end) of all marine mammal 
monitoring;
    (ii) Construction activities occurring during each daily 
observation period, including the number and type of piles that were 
driven or removed and by what method (i.e., impact or vibratory), total 
duration of driving time for each pile (vibratory) and number of 
strikes for each pile (impact);
    (iii) PSO locations during marine mammal monitoring;
    (iv) Environmental conditions during monitoring periods (at 
beginning and

[[Page 81866]]

end of PSO shift and whenever conditions change significantly), 
including Beaufort sea state and any other relevant weather conditions 
including cloud cover, fog, sun glare, and overall visibility to the 
horizon, and estimated observable distance;
    (v) Upon observation of a marine mammal, the following information:
    (A) Name of PSO who sighted the animal(s) and PSO location and 
activity at time of sighting;
    (B) Time of sighting;
    (C) Identification of the animal(s) (e.g., genus/species, lowest 
possible taxonomic level, or unidentified), PSO confidence in 
identification, and the composition of the group if there is a mix of 
species;
    (D) Distance and location of each observed marine mammal relative 
to the pile being driven for each sighting;
    (E) Estimated number of animals (min/max/best estimate);
    (F) Estimated number of animals by cohort (adults, juveniles, 
neonates, group composition, etc.);
    (G) Animal's closest point of approach and estimated time spent 
within the harassment zone; and
    (H) 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);
    (vi) Number of marine mammals detected within the harassment zones, 
by species; and
    (vii) Detailed information about implementation of any mitigation 
(e.g., shutdown and delays), a description of specific actions that 
ensued, and resulting changes in behavior of the animal(s), if any.
    (11) The Holder must submit all PSO data electronically in a format 
that can be queried such as a spreadsheet or database (i.e., digital 
images of data sheets are not sufficient);
    (12) The Navy must report hydroacoustic data collected as required 
by a LOA issued under Sec. Sec.  216.106 of this chapter and 217.236 
and as discussed in the Navy's Acoustic Monitoring Plan approved by 
NMFS;
    (13) In the event that personnel involved in the construction 
activities discover an injured or dead marine mammal, the Navy shall 
report the incident to the Office of Protected Resources (OPR), NMFS, 
and to the Greater Atlantic Region New England/Mid-Atlantic Regional 
Stranding Coordinator as soon as feasible. If the death or injury was 
clearly caused by the specified activity, the Navy must immediately 
cease the specified activities until NMFS 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 
authorization. The Navy must not resume their activities until notified 
by NMFS. The report must include the following information:
    (i) Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    (ii) Species identification (if known) or description of the 
animal(s) involved;
    (iii) Condition of the animal(s) (including carcass condition if 
the animal is dead);
    (iv) Observed behaviors of the animal(s), if alive;
    (v) If available, photographs or video footage of the animal(s); 
and
    (vi) General circumstances under which the animal was discovered.


Sec.  217.236  Letters of Authorization.

    (a) To incidentally take marine mammals pursuant to these 
regulations, the Navy must apply for and obtain an LOA.
    (b) An LOA, unless suspended or revoked, may be effective for a 
period of time not to exceed the expiration date of these regulations.
    (c) If an LOA expires prior to the expiration date of these 
regulations, the Navy may apply for and obtain a renewal of the LOA.
    (d) In the event of projected changes to the activity or to 
mitigation and monitoring measures required by an LOA, the Navy must 
apply for and obtain a modification of the LOA as described in Sec.  
217.236.
    (e) The LOA must set forth the following information:
    (1) Permissible methods of incidental taking;
    (2) Means of effecting the least practicable adverse impact (i.e., 
mitigation) on the species, its habitat, and on the availability of the 
species for subsistence uses; and
    (3) Requirements for monitoring and reporting.
    (f) Issuance of the LOA must be based on a determination that the 
level of taking must be consistent with the findings made for the total 
taking allowable under these regulations.
    (g) Notice of issuance or denial of an LOA must be published in the 
Federal Register within 30 days of a determination.


Sec.  217.237  Renewals and modifications of Letters of Authorization.

    (a) An LOA issued under Sec. Sec.  216.106 of this chapter and 
217.236 for the activity identified in Sec.  217.230(a) may be renewed 
or modified upon request by the applicant, provided that:
    (1) The specified activity and mitigation, monitoring, and 
reporting measures, as well as the anticipated impacts, are the same as 
those described and analyzed for these regulations; and
    (2) NMFS determines that the mitigation, monitoring, and reporting 
measures required by the previous LOA under these regulations were 
implemented.
    (b) For LOA modification or renewal requests by the applicant that 
include changes to the activity or the mitigation, monitoring, or 
reporting that do not change the findings made for the regulations or 
result in no more than a minor change in the total estimated number of 
takes (or distribution by species or years), NMFS may publish a notice 
of proposed LOA in the Federal Register, including the associated 
analysis of the change, and solicit public comment before issuing the 
LOA.
    (c) A LOA issued under Sec. Sec.  216.106 of this chapter and 
217.236 for the activity identified in Sec.  217.230(a) may be modified 
by NMFS under the following circumstances:
    (1) NMFS may modify (including augment) the existing mitigation, 
monitoring, or reporting measures (after consulting with Navy regarding 
the practicability of the modifications) if doing so creates a 
reasonable likelihood of more effectively accomplishing the goals of 
the mitigation and monitoring set forth in the preamble for these 
regulations;
    (i) Possible sources of data that could contribute to the decision 
to modify the mitigation, monitoring, or reporting measures in a LOA:
    (A) Results from Navy's monitoring from previous years;
    (B) Results from other marine mammal and/or sound research or 
studies; and
    (C) Any information that reveals marine mammals may have been taken 
in a manner, extent or number not authorized by these regulations or 
subsequent LOAs; and
    (ii) If, through adaptive management, the modifications to the 
mitigation, monitoring, or reporting measures are substantial, NMFS 
must publish a notice of proposed LOA in the Federal Register and 
solicit public comment;
    (2) If NMFS determines that an emergency exists that poses a 
significant risk to the well-being of the species or stocks of marine 
mammals specified in

[[Page 81867]]

a LOA issued pursuant to Sec.  216.106 of this chapter and Sec.  
217.236, a LOA may be modified without prior notice or opportunity for 
public comment. Notification will be published in the Federal Register 
within 30 days of the action.

[FR Doc. 2024-23392 Filed 10-8-24; 8:45 am]
BILLING CODE 3510-22-P


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