Notice2024-13169
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the New London Pier Extension Project at the Naval Submarine Base
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
June 14, 2024
Effective
December 1, 2024
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
In accordance with the regulations implementing the Marine Mammal Protection Act (MMPA) as amended, notification is hereby given that NMFS has issued an incidental harassment authorization (IHA) to the U.S. Navy (Navy) to incidentally harass marine mammals during construction activities associated with the New London Pier Extension Project at Naval Submarine Base (SUBASE) New London in Groton, Connecticut. There are no changes from the proposed authorization in this final authorization.
Full Text
<html>
<head>
<title>Federal Register, Volume 89 Issue 116 (Friday, June 14, 2024)</title>
</head>
<body><pre>
[Federal Register Volume 89, Number 116 (Friday, June 14, 2024)]
[Notices]
[Pages 50565-50579]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-13169]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XD974]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the New London Pier Extension
Project at the Naval Submarine Base
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of an incidental harassment authorization.
-----------------------------------------------------------------------
SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued an incidental harassment authorization (IHA) to
the U.S. Navy (Navy) to incidentally harass marine mammals during
construction activities associated with the New London Pier Extension
Project at Naval
[[Page 50566]]
Submarine Base (SUBASE) New London in Groton, Connecticut. There are no
changes from the proposed authorization in this final authorization.
DATES: This authorization is effective from December 1, 2024, through
November 30, 2025.
ADDRESSES: Electronic copies of the application and supporting
documents, as well as a list of the references cited in this document,
may be obtained online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</a>. In case of problems accessing these documents, please call
the contact listed below.
FOR FURTHER INFORMATION CONTACT: Rachel Wachtendonk, Office of
Protected Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are proposed or, if the taking is limited to harassment, a notice of a
proposed IHA is provided to the public for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of the species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of the takings are set forth. The definitions
of all applicable MMPA statutory terms cited above are included in the
relevant sections below.
Summary of Request
On August 21, 2023, NMFS received a request from the Navy for an
IHA to take marine mammals incidental to pile driving and removal
activities associated with the New London Pier Extension Project at
SUBASE New London in Groton, Connecticut. Following NMFS' review of the
application, the Navy submitted a revised version on January 31, 2024.
The application was deemed adequate and complete on February 2, 2024.
The Navy's request is for take of six species of marine mammals by
Level B harassment and for take of harbor seals, gray seals, and harp
seals by Level A harassment. Neither the Navy nor NMFS expects serious
injury or mortality to result from this activity; therefore, an IHA is
appropriate.
There are no changes from the proposed IHA to the final IHA.
Description of Specified Activity
Overview
The Navy is planning the partial demolition and extension of pier
31 at SUBASE New London in Groton, Connecticut (figure 1). The existing
pier 31 will be partially demolished and then an 81-foot (ft), or 24.7-
meter (m), extension will be constructed. This project will also
include the demolition of an existing small access ramp for pier 17.
The project includes impact and vibratory pile installation and
vibratory pile removal. For a portion of the piles, an auger drill will
be used inside the pipe casing to lift sediment.
The pier 31 extension will include the removal of 28 16-inch (in),
or 0.41-m, fiberglass reinforced plastic fender piles. The pier 17
demolition will include the removal of 20 14-in (0.36-m) concrete
encased steel H-piles and 10 timber piles. Existing piles will be
removed by the deadpull method, with timber piles being cut at the
mudline and all other piles being removed with the vibratory hammer if
deadpull is unsuccessful. Once the existing piles are removed, 20 36-in
(0.91-m) steel pipe piles and 60 16-in (0.41-m) fiberglass reinforced
plastic fender piles will be installed to support the pier 31 extension
and pier 17 quaywall. The installation and removal of a temporary work
trestle supported by 60 14-in (0.36-m) steel H-piles will be completed
to support permanent pile installation. Temporary and permanent piles
will be initially installed with a vibratory hammer followed by an
impact hammer to embed them to their final depth. For a portion of the
piles, an auger drill will be used inside the pipe casing to lift
sediment.
In order to maintain project schedules, it is possible that
multiple pieces of equipment will operate at the same time within the
project area. Piles may be extracted and installed on the same day,
with a maximum of three vibratory hammers operating simultaneously. The
method of installation, and whether concurrent pile driving scenarios
will be implemented, will be determined by the construction crew once
the project has begun. Therefore, the total take estimate reflects the
worst-case scenario for the project.
A further detailed description of the planned construction project
is provided in the Federal Register notice for the proposed IHA (89 FR
27717, April 18, 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 specified activity. Mitigation, monitoring, and
reporting measures are described in detail later in this document
(please see Mitigation and Monitoring and Reporting sections).
Comments and Responses
A notice of NMFS' proposal to issue an IHA to the Navy was
published in the Federal Register on April 18, 2024 (89 FR 27717). That
notice described, in detail, the Navy's activity, the marine mammal
species that may be affected by the activity, and the anticipated
effects on marine mammals. In that notice, we requested public input on
the request for authorization described therein, our analyses, the
proposed authorization, and any other aspect of the notice of proposed
IHA, and requested that interested persons submit relevant information,
suggestions, and comments. During the 30-day public comment period,
NMFS did not receive any substantive comments on the proposed IHA.
Changes From the Proposed IHA to Final IHA
Changes were made between publication of the notice of the proposed
IHA and this notice of the final IHA. The Hydroacoustic Monitoring
section was updated for clarification. We clarified that the monitoring
should occur at 10 m (33 ft) from the monitored pile; at a location
intermediate of the pinniped and cetacean Level A (permanent threshold
shift (PTS) onset) zones; and occasionally near the predicted
harassment zones for Level B (behavioral) harassment. Additionally,
table 11 was updated to reflect that the measurements and acoustic
monitoring
[[Page 50567]]
would be conducted for at least 10 percent and up to a maximum of 10 of
each different type of pile and each method of installation. We also
added a requirement that all PSO data will be submitted electronically
with the draft marine mammal report in a format that can be queried,
such as a spreadsheet or database.
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the IHA 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; <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS'
website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 1 lists all species or stocks for which take is expected and
authorized for this activity and summarizes information related to the
population or stock, including regulatory status under the MMPA and
Endangered Species Act (ESA) and potential biological removal (PBR),
where known. PBR is defined by the MMPA as the maximum number of
animals, not including natural mortalities, that may be removed from a
marine mammal stock while allowing that stock to reach or maintain its
optimum sustainable population (as described in NMFS' SARs). While no
serious injury or mortality is anticipated or authorized here, PBR and
annual serious injury and mortality from anthropogenic sources are
included here as gross indicators of the status of the species or
stocks and other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS' U.S. 2022 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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>.
Table 1--Marine Mammal Species \1\ Likely Impacted by the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/ MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\2\ abundance survey) \3\ SI \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
Atlantic White-Sided Dolphin.... Lagenorhynchus acutus.. Western N Atlantic..... -, -, N 93,233 (0.71, 54,443, 544 28
2021).
Common Dolphin.................. Delphinus delphis...... Western N Atlantic..... -, -, N 93,100 (0.56, 59,897, 1,452 414
2021).
Family Phocoenidae (porpoises):
Harbor Porpoise................. Phocoena phocoena...... Gulf of Maine/Bay of -, -, N 85,765 (0.53, 56,420, 649 145
Fundy. 2021).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
Gray Seal....................... Halichoerus grypus..... Western N Atlantic \5\. -, -, N 27,911 (0.20, 23,624, 1,512 4,570
2021).
Harbor Seal..................... Phoca vitulina......... Western N Atlantic..... -, -, N 61,336 (0.08, 57,637, 1,729 339
2018).
Harp Seal....................... Pagophilus Western N Atlantic..... -, -, N 7.6M (UNK, 7.1M, 2019) 426,000 178,573
groenlandicus.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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
(<a href="https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies">https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies</a>; Committee on Taxonomy, 2022).
\2\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or
which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
automatically designated under the MMPA as depleted and as a strategic stock.
\3\ NMFS marine mammal SARs online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region</a>.
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, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
\5\ NMFS' stock abundance estimate (and associated PBR value) applies to the U.S. population only. Total stock abundance (including animals in Canada)
is approximately 394,311. The annual M/SI value given is for the total stock.
As indicated above, all six species (with six managed stocks) in
table 1 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur. All species that could
potentially occur in the project area are included in table 3-1 of the
IHA application. While North Atlantic right whale (Eubalaena
glacialis), common minke whale (Balaenoptera acutorostrata), fin whale
(Balaenoptera physalus), and humpback whale (Megaptera novaeangliae)
have been documented in Long Island Sound, the spatial and temporal
occurrence of these species is such that take is not expected to occur,
and they are not discussed further beyond the explanation provided
here. These species occur at low densities at the mouth of the Thames
River, extending into Long Island Sound, and do not occur in the Thames
River. Sound from the project is only expected to propagate into the
Long Island Sound during the vibratory driving of the 36-in steel pipe
piles. Only a small portion of the Long Island Sound will be
ensonified, and therefore incidental take of these species is not
anticipated.
A detailed description of the species likely to be affected by the
Navy's construction project, including brief
[[Page 50568]]
introductions to the species and relevant stocks as well as available
information regarding population trends and threats, and information
regarding local occurrence, were provided in the Federal Register
notice for the proposed IHA (89 FR 27717, April 18, 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 the NMFS website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>) 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).
Otariid pinnipeds (OW) (underwater) 60 Hz to 39 kHz.
(sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65-dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al., 2007) and PW pinniped (approximation).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth et al.,
2013). This division between phocid and otariid pinnipeds is now
reflected in the updated hearing groups proposed in Southall et al.
(2019).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The effects of underwater noise from the Navy's pile driving
activities have the potential to result in behavioral harassment of
marine mammals in the vicinity of the project area. The notice of the
proposed IHA (89 FR 27717, April 18, 2024) included a discussion of the
effects of anthropogenic noise on marine mammals and the potential
effects of underwater noise from the Navy's pile driving activities on
marine mammals and their habitat. That information and analysis is
incorporated by reference into this final IHA determination and is not
repeated here; please refer to the notice of the proposed IHA (89 FR
27717, April 18, 2024).
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
authorized through the IHA, which will inform NMFS' consideration of
``small numbers,'' the negligible impact determinations, and impacts on
subsistence uses.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which: (i) has the potential to injure
a marine mammal or marine mammal stock in the wild (Level A
harassment); or (ii) has the potential to disturb a marine mammal or
marine mammal stock in the wild by causing disruption of behavioral
patterns, including, but not limited to, migration, breathing, nursing,
breeding, feeding, or sheltering (Level B harassment).
Authorized takes will primarily be by Level B harassment, as use of
the acoustic (i.e., pile driving) has the potential to result in
disruption of behavioral patterns for individual marine mammals. There
is also some potential for auditory injury (Level A harassment) to
result, primarily for phocids because no other species have been
observed within the Thames River adjacent to the project site, and the
Level A harassment isopleths do not extend to the Long Island Sound.
The mitigation and monitoring measures are expected to minimize the
severity of the taking to the extent practicable. As described
previously, no serious injury or mortality is anticipated or authorized
for this activity. Here we describe how the information provided above
is synthesized to produce a quantitative estimate of the take that is
reasonably likely to occur and is authorized.
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
[[Page 50569]]
mammals within these ensonified areas; and (4) the number of days of
activities. We note that while these factors can contribute to a basic
calculation to provide an initial prediction of potential takes,
additional information that can qualitatively inform take estimates is
also sometimes available (e.g., previous monitoring results or average
group size). Below, we describe the factors considered here in more
detail and present the authorized take numbers.
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 a PTS of some degree (equated to Level
A harassment).
Level B Harassment--Though significantly driven by received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source or exposure context (e.g., frequency, predictability, duty
cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., bathymetry, other noises in the area,
predators in the area), and the receiving animals (hearing, motivation,
experience, demography, life stage, depth) and can be difficult to
predict (e.g., Southall et al., 2007, 2021; Ellison et al., 2012).
Based on what the available science indicates and the practical need to
use a threshold based on a metric that is both predictable and
measurable for most activities, NMFS typically uses a generalized
acoustic threshold based on received level to estimate the onset of
behavioral harassment. NMFS generally predicts that marine mammals are
likely to be behaviorally harassed in a manner considered to be Level B
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g.,
scientific sonar) sources. Generally speaking, Level B harassment take
estimates based on these behavioral harassment thresholds are expected
to include any likely takes by temporary threshold shift (TTS) as, in
most cases, the likelihood of TTS occurs at distances from the source
less than those at which behavioral harassment is likely. TTS of a
sufficient degree can manifest as behavioral harassment, as reduced
hearing sensitivity and the potential reduced opportunities to detect
important signals (conspecific communication, predators, prey) may
result in changes in behavior patterns that would not otherwise occur.
The Navy's activity includes the use of continuous (vibratory pile
driving and auger drilling) and impulsive (impact pile driving)
sources, and therefore the RMS SPL thresholds of 120 and 160 dB re 1
[mu]Pa are applicable.
Level A Harassment--NMFS' Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0;
Technical Guidance, 2018) identifies dual criteria to assess auditory
injury (Level A harassment) to five different marine mammal groups
(based on hearing sensitivity) as a result of exposure to noise from
two different types of sources (impulsive or non-impulsive). The Navy's
activity includes the use of impulsive (impact pile driving) and non-
impulsive (vibratory pile driving and auger drilling) sources.
These thresholds are provided in the table below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS' 2018 Technical Guidance, which may be accessed at:
<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lp,0-pk,flat: 219 Cell 2: LE,p,LF,24h: 199 dB.
dB; LE,p,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lp,0-pk,flat: 230 Cell 4: LE,p,MF,24h: 198 dB.
dB; LE,p,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lp,0-pk,flat: 202 Cell 6: LE,p,HF,24h: 173 dB.
dB; LE,p,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lp,0-pk,flat: 218 Cell 8: LE,p,PW,24h: 201 dB.
dB; LE,p,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lp,0-pk,flat: 232 Cell 10: LE,p,OW,24h: 219 dB.
dB; LE,p,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric thresholds for impulsive sounds: Use whichever results in the largest isopleth for calculating PTS
onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level thresholds
associated with impulsive sounds, these thresholds are recommended for consideration.
Note: Peak sound pressure level (Lp,0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
exposure level (LE,p) 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 to 160 kHz). The subscript associated with cumulative
sound exposure level thresholds indicates the designated marine mammal auditory weighting function (LF, MF,
and HF cetaceans, and PW and OW pinnipeds) and that the recommended accumulation period is 24 hours. The
weighted cumulative sound exposure level thresholds could be exceeded in a multitude of ways (i.e., varying
exposure levels and durations, duty cycle). When possible, it is valuable for action proponents to indicate
the conditions under which these thresholds will be exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that are used in estimating the area ensonified above the
acoustic thresholds, including source levels and transmission loss
coefficient.
The sound field in the project area is the existing background
noise plus additional construction noise from the project. Pile driving
generates underwater noise that can potentially result in disturbance
to marine mammals in the project area. The maximum (underwater) area
ensonified is determined by the topography of the Thames River,
including intersecting land masses that will reduce the overall area of
potential impact. Additionally, vessel traffic, including large vessels
and ferries, in the project area may contribute to elevated background
noise levels, which may mask sounds produced by the project.
[[Page 50570]]
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 x Log<INF>10</INF> (R<INF>1</INF>/R<INF>2</INF>),
where
TL = transmission loss in dB;
B = transmission loss coefficient; for practical spreading equals
15;
R<INF>1</INF> = the distance of the modeled SPL from the driven
pile; and,
R<INF>2</INF> = 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
(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 x log<INF>10</INF>[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 3 dB in sound level for each doubling of distance from the source
(10 x log<INF>10</INF>[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 would 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,
NMFS used acoustic monitoring data from other locations to develop
proxy source levels for the various pile types, sizes and methods
(table 4). Generally, we choose source levels from similar pile types
from locations (e.g., geology, bathymetry) similar to the project.
Table 4--Proxy Sound Source Levels for Pile Sizes, Driving Methods, and Auger Drilling
--------------------------------------------------------------------------------------------------------------------------------------------------------
Peak SPL (re 1 RMS SPL (re 1 SEL (re 1 [mu]Pa
Pile type Pile size Method [mu]Pa (rms)) [mu]Pa (rms)) (rms)) Source
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steel........................... 14-in H-pile....... Vibratory.......... NA 158 158 Navy, 2019b.
Impact............. 194 177 162 Navy, 2019b.
36-in pipe pile.... Vibratory.......... NA 168 168 Navy, 2018.
Impact............. 209 198 183 Navy, 2019b.
Auger drilling..... NA 154 NA Dazey et al., 2012.
Concrete encased steel.......... 14-in H-pile....... Vibratory.......... 185 162 157 Caltrans, 2020.
Fiberglass reinforced plastic... 16-in fender....... Vibratory.......... NA 158 NA Illingworth and
Rodkin, 2017.
Impact............. 177 165 157 California
Department of
Transportation,
2015.
--------------------------------------------------------------------------------------------------------------------------------------------------------
For this project, up to three vibratory hammers may operate
simultaneously. When 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 if that difference is
between 0 and 1 dB, 3 dB are added to the higher sound source levels;
if the difference is between 2 and 3 dB, 2 dB are added to the highest
sound source levels; if the difference is between 4 and 9 dB, 1 dB is
added to the highest sound source levels; and with differences of 10 or
more dB, there is no addition. For simultaneous usage of three or more
continuous sound sources, the three overlapping sources with the
highest sound source levels are identified. Of the three highest sound
source levels, the lower two are combined using the above rules; then,
the combination of the lower two is combined with the highest of the
three. The calculated proxy source levels for the different potential
concurrent pile driving scenarios are shown in table 5.
Table 5--Calculated Proxy Sound Source Levels for Potential Concurrent Pile Driving Scenarios
----------------------------------------------------------------------------------------------------------------
Structure Pile type and proxy Calculated proxy sound source level
----------------------------------------------------------------------------------------------------------------
Temporary work trestle installation and Vibratory installation of 14- 163 dB RMS.
pier 17 demolition. in steel H-pile: 158 dB RMS.
Vibratory demolition of 14-
in concrete encased steel H-
pile: 162 dB RMS..
Temporary work trestle installation, pier Vibratory installation of 14- 165 dB RMS.
17 demolition, and pier 31 demolition. in steel H-pile: 158 dB RMS.
Vibratory demolition of 14-
in concrete encased steel H-
pile: 162 dB RMS..
Vibratory demolition of 16-
in fiberglass reinforced
plastic fender: 158 dB RMS..
Temporary work trestle installation and Vibratory installation of 14- 161 dB RMS.
pier 31 demolition. in steel H-pile: 158 dB RMS.
Vibratory demolition of 16-
in fiberglass reinforced
plastic fender: 158 dB RMS..
----------------------------------------------------------------------------------------------------------------
[[Page 50571]]
The ensonified area associated with Level A harassment is more
technically challenging to predict due to the need to account for a
duration component. Therefore, NMFS developed an optional User
Spreadsheet tool to accompany the Technical Guidance that can be used
to relatively simply predict an isopleth distance for use in
conjunction with marine mammal density or occurrence to help predict
potential takes. We note that because of some of the assumptions
included in the methods underlying this optional tool, we anticipate
that the resulting isopleth estimates are typically going to be
overestimates of some degree, which may result in an overestimate of
potential take by Level A harassment. However, this optional tool
offers the best way to estimate isopleth distances when more
sophisticated modeling methods are not available or practical. For
stationary sources, like pile driving, the optional User Spreadsheet
tool predicts the distance at which, if a marine mammal remained at
that distance for the duration of the activity, it would be expected to
incur PTS. Inputs used in the optional User Spreadsheet tool, and the
resulting estimated isopleths, are reported below.
Table 6--NMFS User Spreadsheet Inputs
----------------------------------------------------------------------------------------------------------------
Duration of
Weighting sound
Pile size and Spreadsheet tab factor Number of production Number of
Method type used adjustment piles per within 24-h strikes
(kHz) day period per pile
(sec)
----------------------------------------------------------------------------------------------------------------
Vibratory.................... 16-in A.1. Vibratory 2.5 2 2,400 NA
fiberglass pile driving.
reinforced
plastic fender
piles install
and removal.
14-in steel H- A.1. Vibratory 2.5 5 6,000 NA
pile pile driving.
(temporary)
install and
removal.
14-in concrete A.1. Vibratory 2.5 5 6,000 NA
encased steel pile driving.
H-pile removal.
36-in steel A.1 Vibratory 2.5 0.17 428.4 NA
pipe pile pile driving.
install.
Impact....................... 16-in E.1. Impact 2 2.5 NA 1,000
fiberglass pile driving.
reinforced
plastic fender
piles.
14-in steel H- E.1. Impact 2 4 NA 1,000
pile pile driving.
(temporary)
install.
36-in steel E.1. Impact 2 2.5 NA 1,000
pipe pile pile driving.
install.
Auger drilling............... 36-in steel A. Stationary 2 1 28,800 NA
pipe pile source: non-
install. impulsive,
continuous.
Concurrent pile driving...... 14-in steel H- A.1. Vibratory 2.5 5 6,000 NA
pile AND 14-in pile driving.
concrete
encased steel
H-pile.
14-in steel H- A.1. Vibratory 2.5 5 6,000 NA
pile AND 14-in pile driving.
concrete
encased steel
H-pile AND 16-
in fiberglass
reinforced
plastic fender.
14-in steel H- A.1. Vibratory 2.5 7 8,400 NA
pile AND 16-in pile driving.
fiberglass
reinforced
plastic fender.
----------------------------------------------------------------------------------------------------------------
Table 7--Calculated Level A and Level B Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment zone (m/km\2\)
Method Pile size and type ------------------------------------------------------------------ Level B harassment
MF-cetaceans HF-cetaceans Phocid zone (m/km\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory............................. 16-in fiberglass 0.3/0 4.9/0.000075 2.0/0.00013 3,415/2.47916
reinforced plastic
fender piles install
and removal.
14-in steel H-pile 0.5/0.000001 9.0/0.000253 3.7/0.000043
(temporary) install and
removal.
14-in concrete encased 1.0/0.000003 16.5/0.000851 6.8/0.000145 6,310/2.620145
steel H-pile removal.
36-in steel pipe pile 0.4/0.000001 7.2/0.000162 2.9/0.00026 15,849/3.435273
install.
Impact................................ 16-in fiberglass 1.2/0.00005 40.5/0.005136 18.2/0.001035 22/0.001513
reinforced plastic
fender piles.
14-in steel H-pile 3.6/0.000041 119.3/0.044565 53.6/0.009004 136/0.056637
(temporary) install.
36-in steel pipe pile 65.4/0.01341 2,191/1.588304 984.4/0.86872 3,415/2.620145
install.
Auger drilling........................ 36-in steel pipe pile 0.1/0 0.8/0.000002 0.5/0.000001 1,848/1.359058
install.
Concurrent pile driving............... 14-in steel H-pile AND \a\ \b\ 1.2/0.000005 \a\ 19.3/0.001164 \a\ \b\ 7.9/0.000195 \a\ 7,356/3.121835
14-in concrete encased \b\ 19.3/0.001134 \b\ 7,356/0.205166
steel H-pile.
14-in steel H-pile AND \a\ \b\ \c\ 1.6/ \a\ \c\ 26.2/ \a\ \b\ \c\ 10.8/ \a\ 10,000/3.197942
14-in concrete encased 0.000008 0.002146 0.000365 \b\ 10,000/0.205166
steel H-pile AND 16-in \b\ 26.2/0.001807 \c\ 10,000/2.822399
fiberglass reinforced
plastic fender.
14-in steel H-pile AND \a\ \b\ 1.1/0.000004 \a\ \b\ 17.8/0.00099 \a\ \b\ 7.3/0.000167 \a\ 5,412/3.078261
16-in fiberglass \b\ 5,412/2.822399
reinforced plastic
fender.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Harassment zones mapped from pier 31.
\b\ Harassment zones mapped from pier 17.
\c\ Harassment zones mapped from existing pier 31 for fender pile extraction.
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. Density estimates come from
Northeast Ocean Data (2023) for cetaceans and from the U.S. Navy Marine
Species Density Database (Navy, 2017) for pinnipeds. To determine the
incidental take estimate within each harassment zone, the following
equation was used:
Incidental take estimate = (harassment zone [km\2\] x estimated density
[individuals/km\2\]) x days of pile driving activity
A subset of the species (Atlantic white-sided dolphin, common
dolphin, and harbor porpoise) do not occur within the Thames River and
have only been observed in the Long Island Sound. For these species,
the area from the mouth of the Thames River to the furthest extent of
the harassment zone in the Long Island Sound was used to
[[Page 50572]]
determine the incidental take estimate within that zone.
Atlantic White-Sided Dolphin
Atlantic white-sided dolphins do not occur within the Thames River
but they occur occasionally in the Long Island Sound. Monthly surveys
conducted in the Thames River from 2017 through 2019 did not record the
presence of Atlantic white-sided dolphins (Tetra Tech, 2019). The
average density of Atlantic white-sided dolphins in the Long Island
Sound is 0.022 individuals per square kilometer (km\2\). Only vibratory
pile driving activities will generate a harassment zone that extends
into the Long Island Sound so for those activities the area from the
mouth of the Thames River to the furthest extent in the Long Island
Sound (0.24 km\2\) was used to calculate take (table 8). Therefore,
using the equation given above, the calculated estimated take by Level
B harassment for Atlantic white-sided dolphins would be one. However,
Atlantic white-sided dolphins typically travel in pods, so the
estimated take by Level B harassment was increased to the average group
size of 12 (NMFS, 2023b).
The largest Level A harassment zone for Atlantic white-sided
dolphins extends 65 m from the sound source (table 9) and is entirely
contained within the Thames River. Therefore, no take by Level A
harassment is anticipated or authorized.
Common Dolphin
Common dolphins do not occur within the Thames River but they occur
occasionally in the Long Island Sound. Monthly surveys conducted in the
Thames River from 2017 through 2019 did not record the presence of
common dolphins (Tetra Tech, 2019). The average density of common
dolphins in the Long Island Sound is 0.15 individuals per km\2\. Only
vibratory pile driving activities will generate a harassment zone that
extends into the Long Island Sound so for those activities the area
from the mouth of the Thames River to the furthest extent in the Long
Island Sound (0.24 km\2\) was used to calculate take (table 8).
Therefore, using the equation given above, the calculated estimate of
take by Level B harassment for common dolphins would be four. However,
common dolphins generally travel in pods, so the estimated take by
Level B harassment was increased to an assumed average group size of 30
(NMFS, 2023b).
The largest Level A harassment zone for common dolphins extends 65
m from the sound source (table 7) and is entirely contained within the
Thames River. Therefore, no take by Level A harassment is anticipated
or authorized.
Harbor Porpoise
Harbor porpoises do not occur within the Thames River but they
occur occasionally in the Long Island Sound. Monthly surveys conducted
in the Thames River from 2017 through 2019 did not record the presence
of harbor porpoises (Tetra Tech, 2019). The average density of harbor
porpoises in the Long Island Sound is 0.32 individuals per km\2\. Only
vibratory pile driving activities will generate a harassment zone that
extends into the Long Island Sound so for those activities the area
from the mouth of the Thames River to the furthest extent in the Long
Island Sound (0.24 km\2\) was used to calculate take (table 8).
Therefore, using the equation given above, the estimated take by Level
B harassment for harbor porpoises would be nine.
The largest Level A harassment zone for harbor porpoises extends
2,191 m from the sound source (table 7) and is entirely contained
within the Thames River. Therefore, no take by Level A harassment is
anticipated or authorized.
Table 8--Estimated Take by Level B Harassment for Species Observed Only in the Long Island Sound Portion of the Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
Calculated Total
Total Ensonfied area Density estimated authorized
Method Pile size and type ensonified within the Species (individuals/ take by Group take by
area Long Island km\2\) Level B size Level B
(km\2\) Sound (km\2\) harassment harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact............... 36-in steel pipe pile 3.435273 0.24 Atlantic white-sided 0.022 1 12 12
install. dolphin.
Common dolphin......... 0.15 4 30 30
Harbor porpoise........ 0.32 9 3 9
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor Seal
Harbor seals are present in the project vicinity including the
Thames River from September through May. Monthly surveys conducted in
the Thames River from 2017 through 2019 recorded 12 sightings of
individual harbor seals (Tetra Tech, 2019). Seals were not observed on
the shore and there are no harbor seal haulouts within the project
vicinity. Two different density estimates were used to calculate harbor
seal take. A density of 0.049 individuals per km\2\ was used in the
Thames River and a density of 0.07 individuals per km\2\ was used in
the Long Island Sound (Navy, 2017). Therefore, using the equation given
above, the estimated number of takes by Level B harassment for harbor
seals would be 44.
The largest Level A harassment zone for harbor seals extends 984 m
from the sound source (table 7). Using the equation given above, the
calculated estimated take by Level A harassment for harbor seals would
be 1. However, due to the consistent presence of phocid pinnipeds at
the SUBASE over the last several years, NMFS conservatively authorizes
increasing the estimated take by Level A harassment to one per 30 days
of pile driving resulting in an estimated 8 harbor seals by Level A
harassment over the course of the project.
Gray Seal
Gray seals are present in the project vicinity including the Thames
River from March through June. Monthly surveys conducted in the Thames
River from 2017 through 2019 recorded three sightings of individual
gray seals (Tetra Tech, 2019). Seals were not observed on the shore and
there are no gray seal haulouts within the project vicinity. Two
different density estimates were used to calculate take of gray seals.
A density of 0.049 individuals per km\2\ was used in the Thames River
and a density of 0.07 individuals per km\2\ was used in the Long Island
Sound (Navy, 2017). Therefore, using the equation given above, the
calculated estimated take by Level B harassment for gray seals would be
44.
The largest Level A harassment zone for gray seals extends 984 m
from the sound source (table 7). Using the equation given above, the
calculated estimated take by Level A harassment for gray seals would be
one. However, due to the consistent presence of phocid pinnipeds at the
SUBASE over the last several years, NMFS conservatively authorized
increasing the estimated take by Level A harassment to one per 30 days
of pile driving resulting in an
[[Page 50573]]
estimate of 8 takes of harbor seals by Level A harassment over the
course of the project.
Harp Seal
Harp seals are present in the project vicinity from January through
May and are much rarer in the Thames River then the other two seal
species. Harp seals were not observed during monthly surveys conducted
in the Thames River from 2017 through 2019 (Tetra Tech, 2019). However,
two harp seals were identified in March 2019 and one harp seal in April
2019 by Mystic Aquarium staff. On both occasions they were hauled out
on the finger piers of the marina at SUBASE (Navy, 2019a). The average
density of harp seals in the Long Island Sound is 0.278 individuals per
km\2\. Only vibratory pile driving activities will generate a
harassment zone that extends into the Long Island Sound so for those
activities the area from the mouth of the Thames River to the furthest
extent in the Long Island Sound was used to calculate take. Therefore,
using the equation given above, the estimated take by Level B
harassment for harp seals would be seven. However, it was determined
that up to one take by Level B harassment of harp seals could occur
within the Thames River during each month they are present (January to
May) resulting in an estimate of 12 takes of harp seals by Level B
harassment.
The largest Level A harassment zone for harp seals extends 984 m
from the sound source (table 7) and is entirely contained within the
Thames River. Harp seals do not have a density estimate for within the
Thames River; therefore, given the sightings of this species hauled out
at SUBASE, NMFS authorized increasing the estimated take by Level A
harassment to one per 30 days of pile driving during the period in
which harp seals could occur in the river. This results in an estimate
of 5 takes of harp seals by Level A harassment over the course of the
project.
Table 9--Estimated Take by Level A and Level B Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Authorized
Stock Level A Level B Total take as a
Common name Stock abundance \1\ harassment harassment authorized percentage
take of stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Atlantic white-sided dolphin.................... Western North Atlantic............ 93,233 0 \2\ 12 12 0.01
Common dolphin.................................. Western North Atlantic............ 93,100 0 \2\ 30 30 0.03
Harbor porpoise................................. Gulf of Maine/Bay of Fundy........ 87,765 0 9 9 0.01
Harbor seal..................................... Western North Atlantic............ 61,336 8 44 52 0.08
Gray seal....................................... Western North Atlantic............ 27,911 8 44 52 0.19
Harp seal....................................... Western North Atlantic............ 7,600,000 5 12 17 0.00002
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Stock size is Nbest according to NMFS 2023a draft SARs.
\2\ Authorized take increased to mean group size from AMAPPS (Palka et al., 2017 and 2021).
Mitigation
In order to issue an IHA under section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to the
activity, and other means of effecting the least practicable impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of the species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting the
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks, and their habitat (see 50
CFR 216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, NMFS
considers two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned), the likelihood of effective implementation (probability
implemented as planned); and
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost, and impact on
operations.
In addition to the measures described later in this section, the
Navy will employ the following mitigation measures:
<bullet> The Navy will ensure that construction supervisors and
crews, the monitoring team, and relevant Navy staff are trained prior
to the start of activities subject to the IHA, 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.
<bullet> For those marine mammals for which incidental take has not
been authorized, in-water pile installation/removal will shut down
immediately if such species are observed within or entering the Level B
harassment zone.
<bullet> If take reaches the authorized limit for any species, pile
installation/removal will shut down immediately if these species
approach the Level B harassment zone to avoid additional take.
The following mitigation measures will apply to the Navy's in-water
construction activities:
Shutdown and Monitoring Zones
The Navy must establish shutdown zones and Level B harassment
monitoring zones for all pile driving 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 animal (or in
anticipation of an animal entering the defined area). Shutdown zones
are based on the largest Level A harassment zone for each pile size/
type and driving method, and behavioral monitoring zones are meant to
encompass Level B harassment zones for each pile size/type and driving
method, as shown in table 10. A minimum shutdown zone of 10 m will be
required for all in-water construction activities to avoid physical
interaction with marine mammals. Shutdown zones
[[Page 50574]]
for each activity type are shown in table 10.
Prior to pile driving, shutdown zones and monitoring zones will be
established based on zones represented in table 7. Protected Species
Observers (PSOs) will survey the shutdown zones and surrounding areas
for at least 30 minutes before pile driving activities start. If marine
mammals are found within the shutdown zone, pile driving will be
delayed until the animal has moved out of the shutdown zone, either
verified by an observer or by waiting until 15 minutes has elapsed
without a sighting. If a marine mammal approaches or enters the
shutdown zone during pile driving, the activity will be halted. Pile
driving may resume after the animal has moved out of and is moving away
from the shutdown zone or after at least 15 minutes has passed since
the last observation of the animal.
All marine mammals will be monitored in the Level B harassment to
the extent of visibility for the on-duty PSOs. If a marine mammal for
which take is authorized enters the Level B harassment zone, in-water
activities would continue and PSOs will document the animal's presence
within the estimated harassment zone.
If a species for which authorization has not been granted, or for
which the authorized takes are met, is observed approaching or within
the Level B harassment zone, pile driving activities will be shut down
immediately. Activities will not resume until the animal has been
confirmed to have left the area or 15 minutes has elapsed with no
sighting of the animal.
Table 10--Shutdown and Level B Monitoring Zones by Activity
----------------------------------------------------------------------------------------------------------------
Level B monitoring zone (m)
Minimum ---------------------------------------
Method Pile size and type shutdown zone MF- HF-
(m) cetaceans cetaceans Phocid
----------------------------------------------------------------------------------------------------------------
Vibratory......................... 16-in fiberglass 10 10 10 3,415
reinforced plastic
fender piles
install and removal.
14-in steel H-pile 10 10 10 ..............
(temporary) install
and removal.
14-in concrete 10 30 15 6,310
encased steel H-
pile removal.
36-in steel pipe 10 10 10 15,849
pile install.
Impact............................ 16-in fiberglass 10 45 20 22
reinforced plastic
fender piles.
14-in steel H-pile 10 120 55 136
(temporary) install.
36-in steel pipe 70 200 200 3,415
pile install.
Auger drilling.................... 36-in steel pipe 10 10 10 1,848
pile install.
Concurrent pile driving........... 14-in steel H-pile 10 35 15 7,356
AND 14-in concrete
encased steel H-
pile.
14-in steel H-pile 10 30 15 10,000
AND 14-in concrete
encased steel H-
pile AND 16-in
fiberglass
reinforced plastic
fender.
14-in steel H-pile 10 20 10 5,412
AND 16-in
fiberglass
reinforced plastic
fender.
----------------------------------------------------------------------------------------------------------------
Protected Species Observers
The placement of PSOs during all pile driving and removal
activities (described in detail in the Monitoring and Reporting
section) will ensure that the Thames River and portion of the Long
Island Sound is visible during pile installation.
Pre- and Post-Activity Monitoring
Monitoring must take place from 30 minutes prior to initiation of
pile driving activities (i.e., pre-clearance monitoring) through 30
minutes post-completion of pile driving. Prior to the start of daily
in-water construction activity, or whenever a break in pile driving of
30 minutes or longer occurs, PSOs will observe the shutdown and
monitoring zones for a period of 30 minutes. The shutdown zone will be
considered cleared when a marine mammal has not been observed within
the zone for a 30-minute period. If a marine mammal is observed within
the shutdown zones, pile driving activity will be delayed or halted. If
work ceases for more than 30 minutes, the pre-activity monitoring of
the shutdown zones will commence. A determination that the shutdown
zone is clear must be made during a period of good visibility (i.e.,
the entire shutdown zone and surrounding waters must be visible to the
naked eye).
Soft Start
Soft-start procedures are believed to provide additional protection
to marine mammals by providing warning and/or giving marine mammals a
chance to leave the area prior to the impact hammer operating at full
capacity. For impact driving, an initial set of three strikes will be
made by the hammer at reduced energy, followed by a 30-second waiting
period, then two subsequent three-strike sets before initiating
continuous driving. Soft start will be implemented at the start of each
day's impact pile driving and at any time following cessation of impact
pile driving for a period of 30 minutes or longer.
Based on our evaluation of the applicant's planned measures, NMFS
has determined that the mitigation measures provide the means of
effecting the least practicable impact on the affected species or
stocks and their habitat, paying particular attention to rookeries,
mating grounds, and areas of similar significance.
Monitoring and Reporting
In order to issue an IHA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present while
conducting the activities. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
<bullet> Occurrence of marine mammal species or stocks in the area
in which
[[Page 50575]]
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 must be conducted in accordance with the
Monitoring Plan and section 5 of the IHA. Marine mammal monitoring
during pile driving and removal must be conducted by NMFS-approved PSOs
in a manner consistent with the following:
<bullet> PSOs must be independent of the activity contractor (for
example, 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 education (degree in biological
science or related field) or training for experience; and
<bullet> The Navy must submit PSO Curriculum Vitae for approval by
NMFS prior to the onset of pile driving.
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 the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates, times, and reason for implementation
of mitigation (or why mitigation was not implemented when required);
and marine mammal behavior; and
<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. The Navy will employ up to five
PSOs. PSO locations will provide an unobstructed view of all water
within the shutdown zone(s), and as much of the Level A harassment and
Level B harassment zones as possible. PSO locations may include the
pile installation/extraction barge, shore-based locations (such as pier
17 or pier 32), small boats, and the mouth of the Thames River.
Monitoring will be conducted 30 minutes before, during, and 30
minutes after pile driving/removal 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/
removal 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.
Data Collection
PSOs will use approved data forms to record the following
information:
<bullet> Dates and times (beginning and end) of all marine mammal
monitoring.
<bullet> PSO locations during marine mammal monitoring.
Construction activities occurring during each daily observation
period, including how many and what type of piles were driven or
removed and by what method (i.e., vibratory, impact, or auger
drilling).
<bullet> Weather parameters and water conditions.
<bullet> The number of marine mammals observed, by species,
relative to the pile location and if pile driving or removal was
occurring at time of sighting.
<bullet> Distance and bearings of each marine mammal observed to
the pile being driven or removed.
<bullet> Description of marine mammal behavior patterns, including
direction of travel.
<bullet> Age and sex class, if possible, of all marine mammals
observed.
<bullet> Detailed information about implementation of any
mitigation triggered (such as shutdowns and delays), a description of
specific actions that ensued, and resulting behavior of the animal if
any.
Hydroacoustic Monitoring
The Navy plans to conduct hydroacoustic monitoring, or sound source
verification (SSV), of all pile installation and removal methods.
Hydroacoustic monitoring results may be used to adjust the size of the
Level A and Level B harassment and monitoring zones after a request is
made and approved by NMFS. At minimum, the methodology includes:
<bullet> For underwater recordings, a stationary hydrophone system
with the ability to measure SPLs will be placed in accordance with NMFS
most recent guidance for the collection of source levels.
<bullet> Hydroacoustic monitoring will be successfully conducted
for at least 10 percent and up to a maximum of 10 of each different
type of pile and each method of installation (table 11). Monitoring
will occur at 33 ft (10 m) from the noise; at a location intermediate
of the pinniped and cetacean Level A (PTS onset) zones; and
occasionally near the predicted harassment zones for Level B
(Behavioral) harassment. The resulting data set will be analyzed to
examine and confirm SPLs and rates of TL for each separate in-water
construction activity. With NMFS concurrence, these metrics may be used
to recalculate the limits of the shutdown, Level A (PTS onset), and
Level B (Behavioral) disturbance zones, and to make corresponding
adjustments in marine mammal monitoring of these zones. Hydrophones
will be placed using a static line deployed from a stationary
(temporarily moored) vessel. Locations of hydroacoustic recordings will
be collected via global positioning system. A depth sounder and/or
weighted tape measure will be used to determine the depth of the water.
The hydrophone will be attached to a weighted nylon cord or chain to
maintain a constant depth and distance from the pile area. The nylon
cord or chain will be attached to a float or tied to a static line.
<bullet> Each hydrophone will be calibrated at the start of each
action and will be checked frequently to the applicable standards of
the hydrophone manufacturer.
[[Page 50576]]
<bullet> Environmental data will be collected, including but not
limited to, the following: wind speed and direction, air temperature,
humidity, surface water temperature, water depth, wave height, weather
conditions, and other factors that could contribute to influencing the
airborne and underwater sound levels (e.g., aircraft, boats, etc.).
<bullet> The chief inspector will supply the acoustics specialist
with the substrate composition, hammer/drill model and size, hammer/
drill energy settings, depth of drilling, and boring rates and any
changes to those settings during the monitoring.
<bullet> For acoustically monitored construction activities, data
from the continuous monitoring locations will be post-processed to
obtain the following sound measures:
[cir] Maximum peak pressure level recorded for all activities,
expressed in dB re 1 [mu]Pa.
[ssquf] Mean, median, minimum, and maximum RMS pressure level in
[dB re 1 [mu]Pa].
[ssquf] Mean duration of a pile strike (based on 90 percent energy
criterion).
[ssquf] Number of hammer strikes.
[ssquf] Mean, median, minimum, and maximum single strike sound
exposure level (SEL) in [dB re [mu]Pa\2\ sec].
[cir] Cumulative SEL as defined by the mean single strike SEL +
10*log<INF>10</INF> (number of hammer strikes) (dB re [mu]Pa\2\ sec).
[cir] Median integration time used to calculate RMS SPL.
[cir] A frequency spectrum (pressure spectral density) (dB re
[mu]Pa\2\ per Hz) based on the average of up to eight successive
strikes with similar sound. Spectral resolution will be 1 Hz, and the
spectrum will cover nominal range from 7 Hz to 20 kHz.
[cir] Finally, the cumulative SEL will be computed from all the
strikes associated with each pile occurring during all phases, i.e.,
soft start. This measure is defined as the sum of all single strike SEL
values. The sum is taken of the antilog, with log<INF>10</INF> taken of
result to express (dB re [mu]Pa\2\ sec).
<bullet> For vibratory driving/extraction/drilling: duration and
frequency spectrum of vibratory driving per pile; mean, median, and
maximum sound levels (dB re: 1 [micro]Pa): root mean square sound
pressure level (SPL<INF>rms</INF>), SEL<INF>cum</INF> (and timeframe
over which the sound is averaged).
Table 11--Hydroacoustic Monitoring Summary
------------------------------------------------------------------------
Numbe
Pile type Count Method of monitored
install/extract \1\
------------------------------------------------------------------------
14-in steel H-pile........... 60 Impact.......... 6-10
14-in steel H-pile........... 60 Vibratory....... 6-10
36-in steel pipe pile........ 20 Impact.......... 2-10
36-in steel pipe pile........ 20 Vibratory....... 2-10
36-in steel pipe pile........ 20 Auger (rotary) 2-10
drill.
16-in fiberglass reinforced 60 Impact.......... 6-10
plastic fender pile.
16-in fiberglass reinforced 60 Vibratory....... 6-10
plastic fender pile.
14-in concrete encased steel 20 Vibratory....... 2-10
H-pile.
------------------------------------------------------------------------
\1\ Hydroacoustic monitoring would be successfully conducted for at
least 10 percent and up to 10 of each different type of pile and each
method of installation.
Reporting
A draft marine mammal monitoring report will be submitted to NMFS
within 90 days after the completion of pile driving and removal
activities. It 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 the number and type of piles driven or
removed and by what method (i.e., vibratory driving) and the total
equipment duration for cutting for each pile.
<bullet> PSO locations during marine mammal monitoring.
<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.
<bullet> Upon observation of a marine mammal, the following
information: (1) name of PSO who sighted the animal(s) and PSO location
and activity at time of sighting; (2) time of sighting; (3)
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; (4)
distance and bearing of each marine mammal observed relative to the
pile being driven for each sighting (if pile driving was occurring at
time of sighting); (5) estimated number of animals (min/max/best
estimate); (6) estimated number of animals by cohort (adults,
juveniles, neonates, group composition, etc.); (7) animal's closest
point of approach and estimated time spent within the harassment zone;
and (8) 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.
<bullet> Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensued, and resulting changes in behavior of the
animal(s), if any.
<bullet> All PSO data will be submitted electronically in a format
that can be queried such as a spreadsheet or database and would be
submitted with the draft marine mammal report.
If no comments are received from NMFS within 30 days, the draft
final report will constitute the final report. If comments are
received, a final report addressing NMFS comments must be submitted
within 30 days after receipt of comments.
Reporting of Hydroacoustic Monitoring
The Navy shall also submit a draft hydroacoustic monitoring report
to NMFS within 90 days of the completion of required monitoring at the
end of the project, including data in a tabular spreadsheet format
(Microsoft Excel or similar). The report will detail the hydroacoustic
monitoring protocol and
[[Page 50577]]
summarize the data recorded during monitoring. The final 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 shall be
considered final. If comments are received, a final report addressing
NMFS comments must be submitted within 30 days after receipt of
comments. All draft and final hydroacoustic monitoring reports must be
submitted to <a href="/cdn-cgi/l/email-protection#e1b1b3cfa8b5b1cfac8e8f88958e93888f86b384918e939592a18f8e8080cf868e97"><span class="__cf_email__" data-cfemail="0d5d5f2344595d234062636479627f64636a5f687d627f797e4d63626c6c236a627b">[email protected]</span></a> and
<a href="/cdn-cgi/l/email-protection#90d9c4c0bec7f1f3f8e4f5fef4fffefbd0fefff1f1bef7ffe6"><span class="__cf_email__" data-cfemail="cd84999de39aacaea5b9a8a3a9a2a3a68da3a2acace3aaa2bb">[email protected]</span></a>. The hydroacoustic monitoring report will
contain the informational elements described in the Hydroacoustic
Monitoring Plan and, at minimum, will include:
<bullet> Hydrophone equipment and methods: recording device,
sampling rate, distance (m) from the pile where recordings were made;
depth of 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: number of strikes and strike
rate; depth of substrate to penetrate; pulse duration and mean, median,
and maximum sound levels (dB re: 1 [mu]Pa); SPL<INF>rms</INF>;
SEL<INF>cum</INF>; peak sound pressure level (SPL<INF>peak</INF>); and
single-strike sound exposure level (SEL<INF>ss</INF>).
<bullet> For vibratory driving/extraction/drilling: duration and
frequency spectrum of vibratory driving per pile; mean, median, and
maximum sound levels (dB re: 1 [mu]Pa): SPL<INF>rms</INF>,
SEL<INF>cum</INF> (and timeframe over which the sound is averaged).
<bullet> One-third octave band spectrum and power spectral density
plot.
<bullet> General Daily Site Conditions
[cir] Date and time of activities.
[cir] Water conditions (e.g., sea state, tidal state).
[cir] Weather conditions (e.g., percent cover, visibility).
Reporting Injured or Dead Marine Mammals
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
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 IHA. The IHA-holder must not resume their activities until
notified by NMFS. The report must include the following information:
<bullet> Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
<bullet> Species identification (if known) or description of the
animal(s) involved;
<bullet> Condition of the animal(s) (including carcass condition if
the animal is dead);
<bullet> Observed behaviors of the animal(s), if alive;
<bullet> If available, photographs or video footage of the
animal(s); and
<bullet> General circumstances under which the animal was
discovered.
Negligible Impact Analysis and Determination
NMFS has defined negligible impact as an impact resulting from the
specified activity that cannot be reasonably expected to, and is not
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
``taken'' through harassment, NMFS considers other factors, such as the
likely nature of any impacts or responses (e.g., intensity, duration),
the context of any impacts or responses (e.g., critical reproductive
time or location, foraging impacts affecting energetics), as well as
effects on habitat, and the likely effectiveness of the mitigation. We
also assess the number, intensity, and context of estimated takes by
evaluating this information relative to population status. Consistent
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338,
September 29, 1989), the impacts from other past and ongoing
anthropogenic activities are incorporated into this analysis via their
impacts on the baseline (e.g., as reflected in the regulatory status of
the species, population size and growth rate where known, ongoing
sources of human-caused mortality, or ambient noise levels).
To avoid repetition, the discussion of our analysis applies to all
the species listed in table 1, given that the anticipated effects of
this activity on these different marine mammal stocks are expected to
be similar. There is little information about the nature or severity of
the impacts, or the size, status, or structure of any of these species
or stocks that would lead to a different analysis for this activity.
Pile driving activities have the potential to disturb or displace
marine mammals. Specifically, the project activities may result in
take, in the form of Level A harassment and Level B harassment from
underwater sounds generated from pile driving and removal. Potential
takes could occur if individuals are present in the ensonified zone
when these activities are underway.
Estimated takes by Level B harassment would be due to potential
behavioral disturbance, and TTS. Take by Level A harassment would be
due to PTS. No mortality or serious injury is anticipated given the
nature of the activity, even in the absence of the required mitigation,
and therefore none is authorized. The potential for harassment is
minimized through the construction method and the implementation of the
mitigation measures (see Mitigation section).
Take would occur within a limited, confined area (the Thames River
and a small section of the Long Island Sound) of the stocks' ranges.
Take by Level A and Level B harassment would be reduced to the level of
least practicable adverse impact through use of mitigation measures
described herein. Further, the amount of take authorized is extremely
small when compared to stock abundance, and the project is not
anticipated to impact any known important habitat areas for any marine
mammal species.
Take by Level A harassment is authorized to account for the
potential that an animal could enter and remain within the area between
a Level A harassment zone and the shutdown zone for a duration long
enough to be taken by Level A harassment. Any take by Level A
harassment is expected to arise from, at most, a small degree of PTS
because animals would need to be exposed to higher levels and/or longer
duration than are expected to occur here in order to incur any more
than a small degree of PTS. Additionally, and as noted previously, some
subset of the individuals that are behaviorally harassed could
simultaneously incur some small degree of TTS for a short duration of
time. Because of the small degree anticipated, though, any PTS or
[[Page 50578]]
TTS potentially incurred here would not be expected to adversely impact
individual fitness, let alone annual rates of recruitment or survival.
Behavioral responses of marine mammals to pile driving at the
project site, if any, are expected to be mild and temporary. Marine
mammals within the Level B harassment zone may not show any visual cues
they are disturbed by activities or could become alert, avoid the area,
leave the area, or display other mild responses that are not observable
such as changes in vocalization patterns. Given the limited number of
piles to be installed or extracted per day and that pile driving and
removal will occur across a maximum of 242 days within the 12-month
authorization period, any harassment will be temporary.
Any impacts on marine mammal prey that would occur during the
Navy's activity would have, at most, short-term effects on foraging of
individual marine mammals, and likely no effect on the populations of
marine mammals as a whole. Indirect effects on marine mammal prey
during the construction are expected to be minor, and these effects are
unlikely to cause substantial effects on marine mammals at the
individual level, with no expected effect on annual rates of
recruitment or survival.
In addition, it is unlikely that minor noise effects in a small,
localized area of habitat would have any effect on the stocks' annual
rates of recruitment or survival. In combination, we believe that these
factors, as well as the available body of evidence from other similar
activities, demonstrate that the potential effects of the specified
activities will have only minor, short-term effects on individuals. The
specified activities are not expected to impact rates of recruitment or
survival and will therefore not result in population-level impacts.
In summary and as described above, the following factors primarily
support 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 and would not be of a duration or
intensity expected to result in impacts on reproduction or survival;
<bullet> No important habitat areas have been identified within the
project area;
<bullet> For all species, the Thames River and Long Island Sound
are a very small and peripheral part of their range and anticipated
habitat impacts are minor; and
<bullet> The Navy will implement mitigation measures, such as soft-
starts for impact pile driving and shut downs to minimize the numbers
of marine mammals exposed to injurious levels of sound, and to ensure
that take by Level A harassment, is at most, a small degree of PTS.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the monitoring and mitigation
measures, NMFS finds that the total marine mammal take from the
activity will have a negligible impact on all affected marine mammal
species or stocks.
Small Numbers
As noted previously, only take of small numbers of marine mammals
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is fewer than one-third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
Table 9 demonstrates the number of animals that could be exposed to
received noise levels that could cause take by Level A and Level B
harassment for the work at SUBASE. Our analysis shows that less than 1
percent of each affected stock could be taken by harassment. The
numbers of animals authorized to be taken for these stocks is
considered small relative to the relevant stock's abundances, even if
each estimated taking occurred to a new individual--an extremely
unlikely scenario.
Based on the analysis contained herein of the activity (including
the mitigation and monitoring measures) and the anticipated take of
marine mammals, NMFS finds that small numbers of marine mammals would
be taken relative to the population size of the affected species or
stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
determined that the total taking of affected species or stocks will not
have an unmitigable adverse impact on the availability of such species
or stocks for taking for subsistence purposes.
Endangered Species Act
Section 7(a)(2) of the ESA of 1973 (16 U.S.C. 1531 et seq.)
requires that each Federal agency insure that any action it authorizes,
funds, or carries out is not likely to jeopardize the continued
existence of any endangered or threatened species or result in the
destruction or adverse modification of designated critical habitat. To
ensure ESA compliance for the issuance of IHAs, NMFS consults
internally whenever we authorize take for endangered or threatened
species.
No incidental take of ESA-listed species is authorized or expected
to result from this activity. Therefore, NMFS has determined that
formal consultation under section 7 of the ESA is not required for this
action.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must evaluate our action (i.e., the issuance of an IHA) and
alternatives with respect to potential impacts on the human
environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or
mortality) of the Companion Manual for NAO 216-6A, which do not
individually or cumulatively have the potential for significant impacts
on the quality of the human environment and for which we have not
identified any extraordinary circumstances that would preclude this
categorical exclusion. Accordingly, NMFS has determined that the
issuance of this IHA qualifies to be categorically excluded from
further NEPA review.
Authorization
NMFS has issued an IHA to the Navy for the potential harassment of
small numbers of six marine mammal species incidental to the New London
Pier Extension Project at SUBASE in Groton, Connecticut, that includes
the previously explained mitigation, monitoring and reporting
requirements.
[[Page 50579]]
Dated: June 11, 2024.
Angela Somma,
Acting Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2024-13169 Filed 6-13-24; 8:45 am]
BILLING CODE 3510-22-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on June 14, 2024.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.