Notice2023-09193
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Construction Activities Associated With the Murray St. Bridge Seismic Retrofit Project in Santa Cruz, California
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
May 2, 2023
Effective
May 1, 2023
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 two consecutive incidental harassment authorizations (IHAs) to the City of Santa Cruz to incidentally harass marine mammals during construction activities associated with the seismic retrofit of the Murray St. Bridge in Santa Cruz, California.
Full Text
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<title>Federal Register, Volume 88 Issue 84 (Tuesday, May 2, 2023)</title>
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[Federal Register Volume 88, Number 84 (Tuesday, May 2, 2023)]
[Notices]
[Pages 27452-27462]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-09193]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XC897]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Construction Activities Associated
With the Murray St. Bridge Seismic Retrofit Project in Santa Cruz,
California
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of incidental harassment authorizations.
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SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued two consecutive incidental harassment
authorizations (IHAs) to the City of Santa Cruz to incidentally harass
marine mammals during construction activities associated with the
seismic retrofit of the Murray St. Bridge in Santa Cruz, California.
DATES: These authorizations are effective from May 1, 2023 through
April 30, 2024 and May 1, 2024 through April 30, 2025.
FOR FURTHER INFORMATION CONTACT: Jessica Taylor, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the application
and supporting documents, as well as a list of the references cited in
this document, may be obtained online at: <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 above.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are proposed or, if the taking is limited to harassment, a notice of a
proposed 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 April 19, 2022, NMFS received a request from the City of Santa
Cruz (the City) for two consecutive 1-year IHAs to take marine mammals
incidental to construction activities associated with the Murray St.
Bridge seismic retrofit project in Santa Cruz, CA. Following NMFS'
review of the application, the City submitted revised versions on
August 25, 2022, October 25, 2022, and December 13, 2022, and a final
revised version on January 12, 2023. The application was deemed
adequate and complete on January 24, 2023. The
[[Page 27453]]
City's request is for take of small numbers of California sea lions
(Zalophus californianus) and harbor seals (Phoca vitulina richardii) by
Level B harassment and take of small numbers of harbor seals by Level A
harassment. Neither the City nor NMFS expect serious injury or
mortality to result from this activity and, therefore, IHAs are
appropriate. There are no changes from the proposed IHA to the final
IHA.
Description of Activity
Overview
The City plans to conduct a seismic retrofit on the Murray St.
Bridge, which spans the Santa Cruz Small Craft Harbor. As part of the
project, the City will use vibratory pile extraction to temporarily
remove docks and associated piles to accommodate construction access to
the bridge. Impact pile driving will be used to install additional
bridge support piles. In order to facilitate installation of bridge
piles, vibratory extraction may be used to construct a temporary
trestle. As an alternative to the trestle, a temporary barge may be
constructed instead. The purpose of the project is to provide the
bridge with additional vertical support and resistance to lateral
seismic forces by installing additional pilings and structural support
elements.
The City's activity includes impact and vibratory pile driving and
vibratory pile removal, which may result in the incidental take of
marine mammals by Level A and Level B harassment. The Murray St. Bridge
project area includes waters within the Santa Cruz Small Craft Harbor
and adjacent lands managed by the Santa Cruz Port District.
Construction activities will span the course of 2 years, with the first
year beginning on July 1, 2023 and lasting through July 31, 2023. The
second year of construction activities will begin on July 1, 2024 and
last through September 15, 2024. The City has requested an IHA for each
of the 2 project years. However, given the City has applied for
authorization for both project years concurrently and projects use
similar activities, NMFS is issuing this single Federal Register notice
announce the issuance of the two similar, but separate, IHAs.
A detailed description of the planned construction project is
provided in the Federal Register notice for the proposed IHAs (88 FR
12316, February 27, 2023). Since that time, no changes have been made
to the planned construction activities. Therefore, a detailed
description is not provided here. Please refer to the Federal Register
notice for the description of the specific activity. Mitigation,
monitoring, and reporting measures are described in detail later in
this document (please see Mitigation and Monitoring and Reporting).
Comments and Responses
A notice of NMFS' proposal to issue two consecutive IHAs to the
City was published in the Federal Register on February 27, 2023 (88 FR
12316). That notice described, in detail, the City's activities, the
marine mammal species that may be affected by the activities, and the
anticipated effects on marine mammals. In that notice, we requested
public input on the request for authorization described therein, our
analyses, the proposed authorizations, and any other aspect of the
notice of proposed IHAs, and requested that interested persons submit
relevant information, suggestions, and comments. This proposed notice
was available for a 30-day public comment period. During the 30-day
public comment period, NMFS received no public comments.
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history of the potentially affected species. NMFS
fully considered all of this information, and we refer the reader to
these descriptions, incorporated here by reference, instead of
reprinting the information. Additional information regarding population
trends and threats may be found in NMFS' Stock Assessment Reports
(SARs; <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">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 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 expected to occur, 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 stocks managed under the MMPA in this region
are assessed in NMFS' U.S. Pacific SARs. All values presented in Table
1 are the most recent available at the time of publication, including
from the draft 2022 SARs, and are available online at:
<a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>.
Table 1--Marine Mammal Species \4\ 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/
\1\ abundance survey) \2\ SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and
sea lions):
California sea lion............. Zalophus californianus. U.S.................... -, -, N 257,606 (N/A,233,515, 14,011 >320
2014).
Family Phocidae (earless seals)
[[Page 27454]]
Harbor seal..................... Phoca vitulina......... California............. -, -, N 30,968 (N/A, 27,348, 1,641 43
2012).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: <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> assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
\4\ 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)).
As indicated above, the two species (with two managed stocks) in
Table 1 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur. While bottlenose
dolphins (Tursiops truncatus) and harbor porpoises (Phocoena phocoena)
have been reported in the area, the temporal and/or spatial occurrence
of these species is such that take is not expected to occur, and they
are not discussed further beyond the explanation provided here.
Bottlenose dolphins and harbor porpoises may transit nearshore areas
just outside the mouth of the Harbor (Carretta et al., 2022). However,
these species were not detected during any surveys of the Harbor area
and are expected to remain outside the Harbor and beyond the project
area.
In addition, the southern sea otter (Enhydra lutris nereis) may be
found in the Harbor. However, sea otters are managed by the U.S. Fish
and Wildlife Service and are not considered further in this document.
A detailed description of the species likely to be affected by the
construction project, including brief introductions to the species and
relevant stocks as well as available information regarding population
trends and threats, and information regarding local occurrence, were
provided in the Federal Register notice of the proposed IHAs (88 FR
12316, February 27, 2023); since that time, we are not aware of any
changes in the status of these species and stocks; therefore, detailed
descriptions are not provided here. Please refer to that Federal
Register notice for these descriptions. Please also refer to 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 and Holt,
2013).
For more detail concerning these groups and associated frequency
ranges,
[[Page 27455]]
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 City's construction
activities have the potential to result in behavioral harassment of
marine mammals in the vicinity of the project area. The notice of the
proposed IHAs (88 FR 12316, February 27, 2023) included a discussion of
the effects of anthropogenic noise on marine mammals and the potential
effects of underwater noise from the City's construction activities on
marine mammals and their habitat. That information and analysis is
incorporated by reference into this final IHA determination and is not
repeated here; please refer to the notice of the proposed IHAs (88 FR
12316, February 27, 2023).
Estimated Take
This section provides an estimate of the number of incidental takes
authorized through these IHAs, which will inform both NMFS'
consideration of ``small numbers,'' and the negligible impact
determinations.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes will primarily be by Level B harassment, as use of
the acoustic source (i.e., impact 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 predicted auditory
injury zones are larger than for otariids. Auditory injury is unlikely
to occur for otariids. The mitigation and monitoring measures are
expected to minimize the severity of the taking to the extent
practicable.
As described previously, no serious injury or mortality is
anticipated or authorized for this activity. Below we describe how the
authorized take numbers are estimated.
For acoustic impacts, generally speaking, we estimate take by
considering: (1) acoustic thresholds above which NMFS believes the best
available science indicates marine mammals will be behaviorally
harassed or incur some degree of permanent hearing impairment; (2) the
area or volume of water that will be ensonified above these levels in a
day; (3) the density or occurrence of marine mammals within these
ensonified areas; and, (4) the number of days of activities. We note
that while these factors can contribute to a basic calculation to
provide an initial prediction of potential takes, additional
information that can qualitatively inform take estimates is also
sometimes available (e.g., previous monitoring results or average group
size). Below, we describe the factors considered here in more detail
and present the authorized take estimates.
Acoustic Thresholds
NMFS recommends the use of acoustic thresholds that identify the
received level of underwater sound above which exposed marine mammals
would be reasonably expected to be behaviorally harassed (equated to
Level B harassment) or to incur permanent threshold shift (PTS) of some
degree (equated to Level A harassment).
Level B Harassment--Though significantly driven by received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source or exposure context (e.g., frequency, predictability, duty
cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., bathymetry, other noises in the area,
predators in the area), and the 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 City's planned construction activity includes the use of
continuous (vibratory pile driving and removal) 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 City's
planned activity includes the use of impulsive (impact hammer) and non-
impulsive (vibratory hammer) 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="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
[[Page 27456]]
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: L0-pk,flat: 219 dB; LE, LF,24h: 183 dB....................... Cell 2: LE,, LF,24h: 199 dB.
Mid-Frequency (MF) Cetaceans......... Cell 3: L0-pk,flat: 230 dB; LE, MF,24h: 185 dB....................... Cell 4: LE,, MF,24h: 198 dB.
High-Frequency (HF) Cetaceans........ Cell 5: L0-pk,flat: 202 dB; LE,,HF,24h: 155 dB....................... Cell 6: LE, HF,24h: 173 dB.
Phocid Pinnipeds (PW) (Underwater)... Cell 7: L0-pk,flat: 218 dB; LE,,PW,24h: 185 dB....................... Cell 8: LE,PW,24h: 201 dB.
Otariid Pinnipeds (OW) (Underwater).. Cell 9: L0-pk,flat: 232 dB; LE,,OW,24h: 203 dB....................... Cell 10: LE,OW,24h: 219 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 (L0-pk) has a reference value of 1 [mu]Pa, and weighted cumulative sound exposure level (LE,) has a reference value of
1[mu]Pa\2\s. In this Table, thresholds are abbreviated to be more reflective of International Organization for Standardization standards (ISO, 2017).
The subscript ``flat'' is being included to indicate peak sound pressure are flat weighted or unweighted within the generalized hearing range of
marine mammals (i.e., 7 Hz to 160 kHz). The subscript associated with cumulative sound exposure level thresholds indicates the designated marine
mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and that the recommended accumulation period is 24 hours. The
weighted cumulative sound exposure level thresholds could be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty
cycle). When possible, it is valuable for action proponents to indicate the conditions under which these thresholds will be exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that are used in estimating the area ensonified above the
acoustic thresholds, including source levels and transmission loss
coefficient.
The sound field in the project area is the existing background
noise plus additional construction noise from the project. Marine
mammals are expected to be affected by sound generated by the primary
components of the project (i.e., impact and vibratory pile driving).
In order to calculate distances to the Level A harassment and Level
B harassment thresholds for the methods and piles being used in this
project, the City used acoustic monitoring data from various similar
locations to develop source levels for the different pile types, sizes,
and methods planned for use (Table 4).
Table 4--Source Levels for Planned Removal and Installation Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Peak Mean
sound maximum SEL \1\
Activity Location Pile size/type Method pressure RMS SPL (dB re 1 Source
(dB re 1 (dB re 1 [mu]Pa2
[mu]Pa) [mu]Pa) sec)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Removal of existing bridge piles. Bridge Bent 6. Dock 14'' P/C concrete... Vibratory.......... 171 163 155 NAVFAC SW, 2022.
Removal of dock FF&T piles. FF & BY.
Install new permanent bridge Bridge Bents 4 30'' steel in CISS.. Impact............. 210 190 177 Caltrans, 2015.
piles. through 8.
Install new permanent bridge Bridge Bents 4 30'' steel in CISS.. Vibratory.......... 196 159 175 Caltrans, 2020.
piles. through 8.
Install new permanent bridge Dock FF&T piles..... 14'' P/C concrete... Impact............. 185 170 160 Caltrans, 2020.
piles.
Install new permanent bridge Dock FF&T piles..... 14'' P/C concrete... Vibratory.......... 171 163 155 NAVFAC SW, 2022.
piles.
Install temporary trestle piles.. Adjacent to bridge.. 20'' steel \2\...... Vibratory.......... 194 154 NA Caltrans, 2015.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Sound exposure level (SEL).
\2\ 24'' steel pipe used as a proxy for 20'' steel pile for vibratory pile driving.
Level B Harassment Zones
Transmission loss (TL) is the decrease in acoustic intensity as an
acoustic pressure wave propagates out from a source. TL parameters vary
with frequency, temperature, sea conditions, current, source and
receiver depth, water depth, water chemistry, and bottom composition
and topography. The general formula for underwater TL is:
TL = B * 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
The recommended TL coefficient for most nearshore environments is
the practical spreading value of 15. This value results in an expected
propagation environment that would lie between spherical and
cylindrical spreading loss conditions, which is the most appropriate
assumption for the City's activities. The City assumed an open water
attenuation rate of 4.5 dB per doubling of distance. The Level B
harassment zones and ensonified area for the City's activities are
shown in Table 5.
[[Page 27457]]
Table 5--Distances to Level B Harassment Thresholds
------------------------------------------------------------------------
Projected radial
distance to Level B
Pile type/size Method harassment threshold
(m)
------------------------------------------------------------------------
Year 1
------------------------------------------------------------------------
14'' P/C concrete........... Vibratory........... 7,356
------------------------------------------------------------------------
Year 2
------------------------------------------------------------------------
30'' steel pipe pile in CISS Impact.............. 1,000
Vibratory........... 3,981
14'' p/c concrete........... Impact.............. 46
Vibratory........... 7,356
20'' steel pipe piles....... Vibratory........... 1,848
------------------------------------------------------------------------
Level A Harassment Zones
The ensonified area associated with Level A harassment is more
technically challenging to predict due to the need to account for a
duration component. Therefore, NMFS developed an optional User
Spreadsheet tool to accompany the Technical Guidance that can be used
to relatively simply predict an isopleth distance for use in
conjunction with marine mammal density or occurrence to help predict
potential takes. We note that because of some of the assumptions
included in the methods underlying this optional tool, we anticipate
that the resulting isopleth estimates are typically going to be
overestimates of some degree, which may result in an overestimate of
potential take by Level A harassment. However, this optional tool
offers the best way to estimate isopleth distances when more
sophisticated modeling methods are not available or practical. For
stationary sources, such as pile installation or removal, the optional
User Spreadsheet tool predicts the distance at which, if a marine
mammal remained at that distance for the duration of the activity, it
would be expected to incur PTS. The isopleths generated by the User
Spreadsheet used the same TL coefficient as the Level B harassment zone
calculations (i.e., the practical spreading value of 15). Inputs in the
User Spreadsheet tool (i.e., number of piles per day, duration, and/or
strikes per pile) are presented in Table 1 of the Federal Register
notice announcing the proposed IHAs (88 FR 12316, February 27, 2023).
The maximum RMS SPL/SEL SPL for each pile type are presented in Table
4. Resulting Level A harassment isopleths are reported below in Table
6.
Table 6--Distances to Level A Harassment Thresholds
----------------------------------------------------------------------------------------------------------------
Projected distances to Level A
harassment threshold (m)
Pile type/size Method -------------------------------
Phocids Otariids
----------------------------------------------------------------------------------------------------------------
Year 1
----------------------------------------------------------------------------------------------------------------
14'' P/C concrete.......................... Vibratory.......................... 22.6 1.6
----------------------------------------------------------------------------------------------------------------
Year 2
----------------------------------------------------------------------------------------------------------------
30'' steel pipe pile in CISS............... Impact............................. 300 22
Vibratory.......................... 12.3 1
14'' p/c concrete.......................... Impact............................. 13 1
Vibratory.......................... 22.6 1.6
20'' steel pipe piles...................... Vibratory.......................... 5.7 0.4
----------------------------------------------------------------------------------------------------------------
Marine Mammal Occurrence
In this section, we provide information about the occurrence of
marine mammals, including density or other relevant information that
will inform the take calculations. Unless otherwise specified, the term
``pile driving'' in this section, and all following sections, may refer
to either pile installation or removal. NMFS has carefully reviewed the
City's analysis and concludes that it represents an appropriate and
accurate method for estimating incidental take that may be caused by
the City's activities.
Daily occurrence estimates of marine mammals in the project area
are based upon marine mammal surveys conducted in the vicinity of the
Murray St. Bridge by EcoSystems West Consulting Group. Survey sessions
were conducted in December 2006, September 2009 through October 2009.
Of these monitoring years, the maximum counts of California sea lions
and harbor seals were observed in 2009 (Table 7). As the 2009 surveys
occurred during the fall season and the project will occur during the
summer and fall seasons, the 2009 data are likely representative of
maximum occurrences that could be expected in the project area.
[[Page 27458]]
Table 7--Maximum Counts of Species Likely Impacted by Planned Activities
------------------------------------------------------------------------
Species 2006 Monitoring 2009 Monitoring
------------------------------------------------------------------------
California sea lion............... 1 15
Harbor seal....................... 6 11
------------------------------------------------------------------------
Take Estimation
Here, we describe how the information provided above is synthesized
to produce a quantitative estimate of the take that is reasonably
likely to occur and authorized.
Maximum occurrence estimates (reported in Table 7) were multiplied
by the number of days of pile removal and installation (14 days in Year
1; 98 days in Year 2) to calculate estimated take by Level B harassment
of California sea lions and harbor seals (Table 8). The City assumed a
maximum of two harbor seals will be present in the project area that
may be impacted during the 37 days of impact pile driving. The expected
occurrence of two harbor seals was multiplied by the number of impact
pile driving days (37) to estimate take by Level A harassment of harbor
seals. Given the very small Level A harassment isopleths for California
sea lions and mitigation measures, Level A harassment of California sea
lions is not expected nor authorized. By using the sighting-based
approach, take values are not affected by the estimated harassment
distances from Tables 6 and 7. NMFS has carefully reviewed these
methods and agrees with this approach.
Table 8--Estimated Take by Level A and Level B Harassment and Percent of Stock Authorized for Take
--------------------------------------------------------------------------------------------------------------------------------------------------------
Maximum number Percent of
of animals Maximum total Authorized Authorized take Total stock
Species expected to days of in- take by Level by Level B authorized take authorized for
occur/day water work \1\ A harassment harassment take
--------------------------------------------------------------------------------------------------------------------------------------------------------
Year 1
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor Seal.......................................... 11 14 0 154 154 0.49
California Sea Lion.................................. 15 14 0 210 210 0.082
--------------------------------------------------------------------------------------------------------------------------------------------------------
Year 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor Seal.......................................... 11 98 \2\ 74 1,078 1,152 3.72
California Sea Lion.................................. 15 98 0 1,470 1,470 0.57
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Includes potential temporary trestle installation/removal.
\2\ Assumes a maximum of 2 harbor seals sighted per day that may be impacted and 37 days of impact pile driving.
Mitigation
In order to issue an IHA under section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to the
activity, and other means of effecting the least practicable impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of the species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting the
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks, and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, NMFS
considers two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned), the likelihood of effective implementation (probability
implemented as planned); and
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost and impact on
operations.
Shutdown Zones
Prior to commencement of in-water construction activities, the City
will establish shutdown zones for all activities. The purpose of a
shutdown zone is to define an area within which shutdown of the
activity will occur upon sighting of a marine mammal (or in
anticipation of an animal entering the defined area). During all in-
water construction activities, the City will implement a standard
minimum 10 m (32.8 ft) shutdown zone. If a marine mammal enters the
shutdown zone, in-water activities must be stopped until visual
confirmation that the animal has left the zone of the animal is not
sighted for 15 minutes.
All marine mammals will be monitored in the Level B harassment
zones and throughout the area as far as visual monitoring can take
place. If a marine mammal enters the Level B harassment zone, in-water
activities will continue and the animal's presence within the estimated
harassment zone must be documented. Pile driving activity must be
halted upon observation of either a species for which incidental take
is not authorized or a species for which incidental take has been
authorized but the authorized number of takes has been met, entering or
within the harassment zone.
[[Page 27459]]
Table 9--Shutdown Zones and Level B Harassment Zones
----------------------------------------------------------------------------------------------------------------
Minimum shutdown zone (m) Level B
Pile size, type, and method -------------------------------- harassment
Phocid Otariid zone (m)
----------------------------------------------------------------------------------------------------------------
Year 1
----------------------------------------------------------------------------------------------------------------
14'' p/c concrete vibratory removal............................. 10 10 7,356
----------------------------------------------------------------------------------------------------------------
Year 2
----------------------------------------------------------------------------------------------------------------
14'' p/c concrete vibratory install/removal..................... 10 10 7,356
----------------------------------------------------------------------------------------------------------------
14'' p/c concrete impact install................................ 46
30'' steel pile in CISS impact install.......................... 1,000
30'' steel pile in CISS vibratory install....................... 3,981
20'' steel pile vibratory install............................... 1,848
----------------------------------------------------------------------------------------------------------------
Protected Species Observers
The placement of protected species observers (PSOs) during all pile
driving activities (described in the Monitoring and Reporting section)
will ensure that the entire shutdown zone is visible. Should
environmental conditions deteriorate such that the entire shutdown zone
would not be visible (i.e., fog, heavy rain), pile driving will be
delayed until the PSO is confident marine mammals within the shutdown
zone could be detected.
Pre-Activity Monitoring
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 zone 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 that 30-minute period.
If a marine mammal is observed within the shutdown zones listed in
Table 9, 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).
Pre-construction monitoring will also take place over the course of
at least 5 days before commencing in-water construction activities. The
purpose of this monitoring effort will be to update occurrence
information on marine mammals in the project area. Specifically, this
monitoring will cover a period of at least 1 week for 4 hours each day.
Soft-Start Procedures
Soft-start procedures provide additional protection to marine
mammals by providing warning and/or giving marine mammals a chance to
leave the area prior to the hammer operating at full capacity. For
impact pile driving, contractors will be required to provide an initial
set of three strikes from the hammer at reduced energy, followed by a
30-second waiting period, then two subsequent reduced-energy strike
sets. Soft-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 City's mitigation measures, NMFS has
determined that these 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 to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
<bullet> Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the activity; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
<bullet> How anticipated responses to stressors impact either: (1)
long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
<bullet> Mitigation and monitoring effectiveness.
Visual Monitoring
Marine mammal monitoring during pile driving activities will be
conducted by PSOs meeting the following NMFS requirements:
<bullet> Independent PSOs (i.e., not construction personnel) who
have no other assigned tasks during monitoring periods will be used;
<bullet> At least one PSO will have prior experience performing the
duties of a PSO during construction activity pursuant to a NMFS-issued
incidental take authorization;
[[Page 27460]]
<bullet> Other PSOs may substitute education (degree in biological
science or related field) or training for experience; and
<bullet> Where a team of three or more PSOs is required, a lead
observer or monitoring coordinator will be designated. The lead
observer will be required to have prior experience working as a marine
mammal observer during construction.
PSOs will 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 City will have at least one PSO stationed at the best possible
vantage points in the project area to monitor during all pile driving
activities. If a PSO sights a marine mammal in the shutdown zone, the
PSO should notify the equipment operator to shut down. The PSO will let
the contractor know when activities can re-commence. Additional PSOs
may be employed during periods of low or obstructed visibility to
ensure the entirety of the shutdown zones are monitored. A marine
mammal monitoring plan will be developed and submitted to NMFS for
approval prior to commencing in-water construction activities.
Reporting
A draft marine mammal monitoring report will be submitted to NMFS
within 90 days after the completion of pile driving activities for each
IHA, or 60 days prior to a requested date of issuance of any future
IHAs for the project, or other projects at the same location, whichever
comes first. The marine mammal monitoring report will include an
overall description of work completed, a narrative regarding marine
mammal sightings, and associated PSO datasheets. Specifically, the
report will include:
<bullet> Dates and times (begin and end) of all marine mammal
monitoring;
<bullet> Construction activities occurring during each daily
observation period, including: (a) How many and what type of piles were
driven or removed and the method (i.e., impact or vibratory); and (b)
the total duration of time for each pile (vibratory driving) or number
of strikes for each pile (impact driving);
<bullet> PSO locations during marine mammal monitoring; and
<bullet> Environmental conditions during monitoring periods (at
beginning and end of PSO shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance.
PSOs will record all incidents of marine mammal occurrence,
regardless of distance from activity, and will document any behavioral
reactions in concert with distance from piles being driven or removed.
Specifically, PSOs will record the following:
<bullet> Name of PSO who sighted the animal(s) and PSO location and
activity at time of sighting;
<bullet> Time of sighting;
<bullet> Identification of the animal(s) (e.g., genus/species,
lowest possible taxonomic level, or unidentified), PSO confidence in
identification, and the composition of the group if there is a mix of
species;
<bullet> Distance and location of each observed marine mammal
relative to the pile being driven or hole being drilled for each
sighting;
<bullet> Estimated number of animals (min/max/best estimate);
<bullet> Estimated number of animals by cohort (adults, juveniles,
neonates, group composition, etc.);
<bullet> Description of any marine mammal behavioral observations
(e.g., observed behaviors such as feeding or traveling), including an
assessment of behavioral responses thought to have resulted from the
activity (e.g., no response or changes in behavioral state such as
ceasing feeding, changing direction, or flushing);
<bullet> Number of marine mammals detected within the harassment
zones, by species; and
<bullet> Detailed information about implementation of any
mitigation (e.g., shutdowns and delays), a description of specified
actions that ensued, and resulting changes in behavior of the
animal(s), if any.
If no comments are received from NMFS within 30 days, the draft
report will constitute the final report. If comments are received, a
final report addressing NMFS' comments will be required to be submitted
within 30 days after receipt of comments. All PSO datasheets and/or raw
sighting data will be submitted with the draft marine mammal report.
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, the City will report the
incident to the Office of Protected Resources (OPR), NMFS
(<a href="/cdn-cgi/l/email-protection#6535374b2c31354b280a0b0c110a170c0b023700150a171116250b0a04044b020a13"><span class="__cf_email__" data-cfemail="0c5c5e2245585c224163626578637e65626b5e697c637e787f4c62636d6d226b637a">[email protected]</span></a>) and to the West Coast regional
stranding network (866-767-6114) as soon as feasible. If the death or
injury was clearly caused by the specified activity, the City must
immediately cease the activities until NMFS OPR 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
IHAs. The City will not resume their activities until notified by NMFS.
The report will 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
[[Page 27461]]
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
California sea lions and harbor seals, given that the anticipated
effects of this activity on these different marine mammal stocks are
expected to be similar. Where there are meaningful differences between
these species, in anticipated individual responses to activities,
impact of expected take on the population due to differences in
population status, or impacts on habitat, they are described
independently in the analysis below.
Pile installation and removal activities have the potential to
disturb or displace marine mammals. Specifically, the project
activities may result in take, in the form of Level B harassment and,
for harbor seals, Level A harassment, from underwater sounds generated
from impact pile installation and vibratory pile installation and
removal activities. Potential takes could occur if individuals move
into the ensonified zones when these activities are underway.
No serious injury or mortality will be expected, even in the
absence of required mitigation measures, given the nature of the
activities. Further, no take by Level A harassment is anticipated for
California sea lions due to the application of planned mitigation
measures, such as shutdown zones that encompass the Level A harassment
zones for this species. The potential for harassment will be minimized
through the construction method and the implementation of the planned
mitigation measures (see Mitigation section).
Take by Level A harassment is authorized for harbor seals during
Year 2 as the Level A harassment zone for impact pile driving exceeds
the size of the shutdown zone for this activity. Therefore, there is
the possibility that an animal could enter a Level A harassment zone
without being detected, and remain within that zone for a duration long
enough to incur PTS. Any take by Level A harassment is expected to
arise from, at most, a small degree of PTS (i.e., minor degradation of
hearing capabilities within regions of hearing that align most
completely with the energy produced by impact pile driving, such as the
low-frequency region below 2 kHz), not severe hearing impairment or
impairment within the ranges of greatest hearing sensitivity. 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.
Further, the amount of take by Level A harassment authorized for
these species is very low. For California sea lions, NMFS anticipates
and has authorized no Level A harassment take over the duration of the
City's planned activities; for harbor seals, NMFS has authorized no
take by Level A harassment in Year 1 and no more than 74 takes by Level
A harassment in Year 2. If hearing impairment occurs, it is most likely
that the affected animal would lose only a few decibels in its hearing
sensitivity. Due to the small degree anticipated, any PTS potential
incurred would not be expected to affect the reproductive success or
survival of any individuals, much less result in adverse impacts on the
species or stock.
The takes from Level B harassment will be due to potential
behavioral disturbance. On the basis of reports in the literature as
well as monitoring from other similar activities, effects will likely
be limited to reactions such as avoidance, increased swimming speeds,
increased surfacing time, or decreased foraging (if such activity were
occurring) (e.g., Thorson and Reyff, 2006; NAVFAC SW, 2018). Most
likely, individuals will simply move away from the sound source and
temporarily avoid the area where pile driving is occurring. If sound
produced by project activities is sufficiently disturbing, animals are
likely to simply avoid the area while the activities are occurring.
Marine mammals could also experience TTS if they move into the Level B
monitoring zone. TTS is a temporary loss of hearing sensitivity when
exposed to loud sound, and the hearing threshold is expected to recover
completely within minutes to hours. Thus, it is not considered an
injury. While TTS could occur, it is not considered a likely outcome of
this activity. We expect that any avoidance of the project areas by
marine mammals will be temporary in nature and that any marine mammals
that avoid the project areas during construction will not be
permanently displaced. Short-term avoidance of the project areas and
energetic impacts of interrupted foraging or other important behaviors
is unlikely to affect the reproduction or survival of individual marine
mammals, and the effects of behavioral disturbance on individuals is
not likely to accrue in a manner that will affect the rates of
recruitment or survival of any affected stock. The potential for
harassment is minimized through construction methods and the
implementation of planned mitigation strategies (see Mitigation
section).
Anticipated and authorized takes are expected to be limited to
short-term Level A (potential PTS) and Level B harassment (behavioral
disturbance) as construction activities will occur over the course of
14 days in Year 1 and 98 days in Year 2. Take will also occur within a
limited, confined area of each stock's range. Level A and Level B
harassment will be reduced to the level of least practicable adverse
impact through use of mitigation measures described herein. Further,
the amount of take authorized is extremely small when compared to stock
abundance.
No marine mammal stocks for which incidental take is authorized are
listed as threatened or endangered under the ESA or determined to be
strategic or depleted under the MMPA. The relatively low marine mammal
occurrences in the area, small shutdown zones, and monitoring make
injury takes of marine mammals unlikely. The shutdown zones will be
thoroughly monitored before the pile installation or removal begins,
and construction activities will be postponed if a marine mammal is
sighted within the shutdown zone. There is a high likelihood that
marine mammals will be detected by trained observers under
environmental conditions described for the project. Therefore, the
mitigation and monitoring measures are expected to reduce the amount
and intensity for Level A and Level B behavioral harassment.
Furthermore, the pile installation and removal activities analyzed here
are similar to, or less impactful than, numerous construction
activities conducted in other similar locations, which have occurred
with no reported injuries or mortality to marine mammals, and no known
long-term adverse consequences from behavioral harassment.
The project is not expected to have significant adverse effects on
marine mammal habitat. There are no Biologically Important Areas or
ESA-designated critical habitat within the project area, and activities
will not permanently modify existing marine mammal habitat. The
activities may
[[Page 27462]]
cause fish to leave the area temporarily. This could impact marine
mammals' foraging opportunities in a limited portion of the foraging
range, however, due to the short duration of activities and the
relatively small area of affected habitat, the impacts to marine mammal
habitat are not expected to cause significant or long-term negative
consequences.
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 reproduction or survival of any individual
marine mammals, much less affect rates of recruitment or survival and
will therefore not result in population-level impacts.
In summary and as described above, the following factors primarily
support our determination that the impacts resulting from this activity
are not expected to adversely affect any of the species or stocks
through effects on annual rates of recruitment or survival:
<bullet> No serious injury or mortality is anticipated or
authorized;
<bullet> No Level A harassment of California sea lions is
authorized;
<bullet> The small Level A harassment takes of harbor seals
authorized are expected to be of a small degree;
<bullet> The intensity of anticipated takes by Level B harassment
is relatively low for all stocks. Level B harassment will primarily be
in the form of behavioral disturbance, resulting in avoidance of the
project areas around where pile driving or removal activities are
occurring;
<bullet> Biologically important areas or critical habitat have not
been identified within the project area;
<bullet> The lack of anticipated significant or long-term effects
to marine mammal habitat;
<bullet> Effects on marine mammal prey species are expected to be
short-term and, therefore, any associated impacts on marine mammal
feeding are not expected to result in significant or long-term
consequences for individuals, or to accrue to adverse impacts on their
populations; and
<bullet> The efficacy of the mitigation measures in reducing the
effects of the specified activities on all species and stocks.
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 small numbers of incidental take may be
authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is fewer than one-third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
The instances of take NMFS has authorized is below one-third of the
estimated stock abundance for all impacted stocks (Table 8). (In fact,
take of individuals is less than 4 percent of the abundance for all
affected stocks.) The number of takes authorized are small relative to
the relevant stocks or populations, even if each estimated take
occurred to a new individual. Furthermore, these takes are likely to
only occur within a small portion of the each stock's range and the
likelihood that each take will occur to a new individual is low.
Based on the analysis contained herein of the activity (including
the mitigation and monitoring measures) and the anticipated take of
marine mammals, NMFS finds that small numbers of marine mammals will be
taken relative to the population size of the affected species or
stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
determined that the total taking of affected species or stocks will not
have an unmitigable adverse impact on the availability of such species
or stocks for taking for subsistence purposes.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an IHA)
with respect to potential impacts on the human environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or
mortality) of the Companion Manual for NOAA Administrative Order 216-
6A, which do not individually or cumulatively have the potential for
significant impacts on the quality of the human environment and for
which we have not identified any extraordinary circumstances that would
preclude this categorical exclusion. Accordingly, NMFS has determined
that the issuance of the IHA qualifies to be categorically excluded
from further NEPA review.
Endangered Species Act
Section 7(a)(2) of the Endangered Species Act of 1973 (ESA; 16
U.S.C. 1531 et seq.) requires that each Federal agency insure that any
action it authorizes, funds, or carries out is not likely to jeopardize
the continued existence of any endangered or threatened species or
result in the destruction or adverse modification of designated
critical habitat. To ensure ESA compliance for the issuance of IHAs,
NMFS consults internally whenever we propose to authorize take for
endangered or threatened species.
No incidental take of ESA-listed species is authorized or expected
to result from this activity. Therefore, NMFS has determined that
formal consultation under section 7 of the ESA is not required for this
action.
Authorization
NMFS has issued two consecutive IHAs to the City for the potential
harassment of small numbers of harbor seals and California sea lions
incidental to the seismic retrofit of the Murray St. Bridge project in
Santa Cruz, California, provided the previously mentioned mitigation,
monitoring, and reporting requirements are followed.
Dated: April 26, 2023.
Kimberly Damon-Randall
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2023-09193 Filed 5-1-23; 8:45 am]
BILLING CODE 3510-22-P
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</html>Indexed from Federal Register on May 2, 2023.
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