Notice2023-26158
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the City of Oceanside's Harbor Fishing Pier and Non-Motorized Vessel Launch Improvement Project in Oceanside, 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
November 28, 2023
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from the City of Oceanside for authorization to take marine mammals incidental to pile driving activities associated with harbor fishing pier and non-motorized vessel launch improvement in Oceanside, California. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue an incidental harassment authorization (IHA) to incidentally take marine mammals during the specified activities. NMFS is also requesting comments on a possible one-time, 1-year renewal that could be issued under certain circumstances and if all requirements are met, as described in Request for Public Comments at the end of this notice. NMFS will consider public comments prior to making any final decision on the issuance of the requested MMPA authorization and agency responses will be summarized in the final notice of our decision.
Full Text
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<title>Federal Register, Volume 88 Issue 227 (Tuesday, November 28, 2023)</title>
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[Federal Register Volume 88, Number 227 (Tuesday, November 28, 2023)]
[Notices]
[Pages 83081-83098]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-26158]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XD494]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the City of Oceanside's Harbor
Fishing Pier and Non-Motorized Vessel Launch Improvement Project in
Oceanside, California
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization; request
for comments on proposed authorization and possible renewal.
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SUMMARY: NMFS has received a request from the City of Oceanside for
authorization to take marine mammals incidental to pile driving
activities associated with harbor fishing pier and non-motorized vessel
launch improvement in Oceanside, California. Pursuant to the Marine
Mammal Protection Act (MMPA), NMFS is requesting comments on its
proposal to issue an incidental harassment authorization (IHA) to
incidentally take marine mammals during the specified activities. NMFS
is also requesting comments on a possible one-time, 1-year renewal that
could be issued under certain circumstances and if all requirements are
met, as described in Request for Public Comments at the end of this
notice. NMFS will consider public comments prior to making any final
decision on the issuance of the requested MMPA authorization and agency
responses will be summarized in the final notice of our decision.
DATES: Comments and information must be received no later than December
28, 2023.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service and should be submitted via email to
<a href="/cdn-cgi/l/email-protection#db928f8bf5b8b7beadbeb5a8afb2b5be9bb5b4babaf5bcb4ad"><span class="__cf_email__" data-cfemail="e8a1bcb8c68b848d9e8d869b9c81868da886878989c68f879e">[email protected]</span></a>. 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.
Instructions: NMFS is not responsible for comments sent by any
other method, to any other address or individual, or received after the
end of the comment period. Comments, including all attachments, must
not exceed a 25-megabyte file size. All comments received are a part of
the public record and will generally be posted 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> without change. All
personal identifying information (e.g., name, address) voluntarily
submitted by the commenter may be publicly accessible. Do not submit
confidential business information or otherwise sensitive or protected
information.
FOR FURTHER INFORMATION CONTACT: Alyssa Clevenstine, 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.
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 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 preliminarily determined
that the issuance of the proposed IHA qualifies to be categorically
excluded from further NEPA review.
We will review all comments submitted in response to this notice
prior to concluding our NEPA process or making a final decision on the
IHA request.
Summary of Request
On May 16, 2023, NMFS received a request from the City of Oceanside
for an IHA to take marine mammals incidental to construction activities
associated with fishing pier and non-motorized vessel improvement in
Oceanside Harbor, Oceanside, CA. Following NMFS' review of the
application, the City of Oceanside submitted revised versions on July
18 and October 17, 2023. The application was deemed adequate and
complete on November 2, 2023. The City of Oceanside's request is for
take of seven species of marine mammals by Level B harassment only.
Neither the City of Oceanside nor NMFS expect serious injury or
mortality to result from this activity and, therefore, an IHA is
appropriate.
Description of Proposed Activity
Overview
The City of Oceanside proposes to remove and replace the existing
public fishing pier and non-motorized vessel launch in Oceanside
Harbor, Oceanside,
[[Page 83082]]
CA. The purpose of this project is to completely replace the pier and
launch dock with the goals of making the pier larger, bringing the pier
to current code standards, and relocating the launch dock to improve
accessibility. The existing pier is past its design service life and
has inadequate load-bearing capabilities. The applicant intends to use
vibratory extraction to remove four 16-inch octagonal concrete support
piles; vibratory driving to install up to 18 18-inch round plastic-
coated steel piles to within 0.61-1.52 meters (m; 2-5 feet (ft)) of
required depth; and, potentially, impact driving to complete pile
installation depending on observed soil resistance. While not expected
to be required based on site geology, 18 10-inch steel piles may be
used as temporary guide piles to aid in the installation of the larger
18-inch structural piles.
A maximum of 6 non-consecutive days of piling activities is
proposed to occur during the course of construction (5-6 months) from
March 2024 through February 2025. The proposed project footprint is
approximately 0.0081 square kilometers (km\2\; 0.0031 square miles
(mi\2\)) with water depths ranging from approximately -6 m (-20 ft)
below mean lower low water (MLLW) and 2.4 m (7.8 ft) above MLLW.
Dates and Duration
This IHA would be effective from March 1, 2024, until February 28,
2025. The project is anticipated to occur over a period of 183 days (5-
6 months) from March 1, 2024, through February 28, 2025 (excluding work
from April 1 through August 31, 2024, to account for the breeding and
nesting season of the Endangered Species Act (ESA)-listed California
least tern (Sternula antillarum browni)), and in-water pile activity is
anticipated to occur for 6 non-consecutive days during that time. The
City of Oceanside plans to conduct piling activities during daylight
hours, generally limited to between 45 minutes post-sunrise and 45
minutes pre-sunset. Pile removal and installation activities may take
place concurrently, where multiple piles are extracted or installed
during a day, but not coincidentally. Pile extraction is anticipated to
take 1 day and pile installation is anticipated to take 5 days.
Specific Geographic Region
This project would be located at the existing Oceanside Harbor
Fishing Pier in Oceanside, CA (Figure 1), with depths ranging from
approximately 6 m below to 2.4 m above MLLW.
BILLING CODE 3510-22-P
[[Page 83083]]
[GRAPHIC] [TIFF OMITTED] TN28NO23.003
BILLING CODE 3510-22-C
Detailed Description of the Specified Activity
Vibratory extraction of four existing 16-inch octagonal concrete
support piles would occur in 1 day. Vibratory installation of up to 18
18-inch round plastic-coated steel pipe piles, with the potential for
an additional 18 10-inch
[[Page 83084]]
temporary steel guide piles, would occur over 5 days (table 1). If 10-
inch steel guide piles are needed, they will be installed and extracted
via vibratory hammer within the same timeframe as the permanent piles.
New 18-inch steel piles will be installed with a vibratory hammer until
they are within 0.61-1.52 m of the required depth, at which point the
remaining driving will be done with an impact hammer depending on
observed sediment resistance. Temporary 10-inch guide piles would only
be installed to aid in installation of structural 18-inch piles if hard
sediments are encountered that will deflect pile positioning. All
activities may occur with or without high-pressure water jetting.
Table 1--Pile Extraction and Installation Activities
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Duration of
Duration of vibratory Estimated blows
Pile activity Method Pile size (inch), Piles per day activity activity per of impact
material (days) pile driving per pile
(minutes) (strikes)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Extraction.......................... Vibratory.............. 16, concrete.......... 4 1 25 N/A
Installation........................ Vibratory.............. 18, steel............. 4 * 5 25 N/A
Installation........................ Impact................. 18, steel............. 4 * 5 N/A 300
Installation........................ Vibratory.............. 10, steel............. 4 N/A 10 N/A
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Impact pile installation will be used for driving piles 0.61-1.52 m to final depth, depending on observed sediment resistance.
* Vibratory and impact installation of 18-inch steel piles would occur in the same 5 days.
Other pile removal methods, including removing piles via high-
pressure water jet may also occur, but no take of marine mammals is
anticipated to occur incidental to this portion of the project and
these activities will not be discussed further.
Proposed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see Proposed
Mitigation and Proposed Monitoring and Reporting).
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history of the potentially affected species. NMFS
fully considered all of this information and we refer the reader to
these descriptions instead of reprinting the information. Additional
information regarding population trends and threats may be found in
NMFS' Stock Assessment Reports (SAR; <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 2 lists all species or stocks for which take is expected and
proposed to be authorized for this activity, and summarizes information
related to the population or stock, including regulatory status under
the MMPA and ESA and potential biological removal (PBR), where known.
PBR is defined by the MMPA as the maximum number of animals, not
including natural mortalities, that may be removed from a marine mammal
stock while allowing that stock to reach or maintain its optimum
sustainable population (as described in NMFS' SARs). While no serious
injury or mortality is anticipated or proposed to be authorized here,
PBR and annual serious injury and mortality from anthropogenic sources
are included here as gross indicators of the status of the species or
stocks and other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS' U.S. Pacific SARs. All values presented in table 2 are the most
recent available at the time of publication (including from the final
2022 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 2--Marine Mammal Species 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/SI
\2\ abundance survey) \3\ \4\
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Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
Bottlenose dolphin............. Tursiops truncatus.... California Coastal.... -/-; N 453 (0.06, 346, 2011). 2.7 >=2
Long-beaked common dolphin..... Delphinus delphis California............ -/-; N 83,379 (0.216, 69,636, 668 >=29.7
capensis. 2018).
Short-beaked common dolphin.... Delphinus delphis California/Oregon/ -/-; N 1,056,308 (0.21, 8,889 >=30.5
delphis. Washington. 888,971, 2018).
Pacific white-sided dolphin.... Lagenorhynchus California............ -/-; N 34,999 (0.222, 29,090, 279 7
obliquidens. 2018).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
sea lions):
[[Page 83085]]
California sea lion............ Zalophus californianus U.S................... -/-; N 257,606 (N/A, 233,515, 14,011 >321
2015).
Family Phocidae (earless seals):
Harbor seal.................... Phoca vitulina California............ -/-; N 30,968 (0.157, 27,348, 1,641 42.8
richardii. 2012).
Northern elephant seal......... Mirounga California Breeding... -/-; N 187,386 (N/A, 85,369, 5,122 13.7
angustirostris. 2013).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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 stock assessment reports online at: <a href="https://www.nmfs.noaa.gov/pr/sars/">https://www.nmfs.noaa.gov/pr/sars/</a>. CV is coefficient of variation; Nmin is the minimum
estimate of stock abundance.
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, vessel strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A
CV associated with estimated mortality due to commercial fisheries is presented in some cases.
As indicated above, all seven species in table 2 temporally and
spatially co-occur with the activity to the degree that take is
reasonably likely to occur. Based on previous marine mammal monitoring
events near the mouth of Oceanside Harbor (Merkel and Associates, Inc.,
2022; Merkel and Associates, Inc., 2023), other marine mammals rarely
occur within Oceanside Harbor and any occurrence in the project area
would be very rare. While Risso's dolphins (Grampus griseus) and gray
whales (Eschrichtius robustus) have been sighted outside of the harbor
and in coastal waters, these species' general spatial occurrence is
such that take is not expected to occur as they typically occur more
offshore, and they are not discussed further beyond the explanation
provided here.
Bottlenose Dolphin
Bottlenose dolphins (California coastal stock) occur in coastal
waters within 1 km of shore, primarily between Point Conception, CA,
and San Quintin, Mexico (Hansen, 1990, Carretta et al., 1998).
California coastal bottlenose dolphins show little site fidelity and
likely move within their home range in response to patchy
concentrations of nearshore prey (Defran and Weller, 1999, Bearzi et
al., 2009). Oceanographic events may influence the distribution and
residency patterns of dolphins (Hansen and Defran, 1990, Wells et al.,
1990). In southern California, coastal bottlenose dolphins are
typically found within 250 m of the shoreline (Hansen and Defran,
1993).
Bottlenose dolphin sightings are not common in Oceanside Harbor but
do occur, typically within the outer surge basin of the harbor and,
rarely, within the inner harbor.
Common Dolphin (Long-Beaked and Short-Beaked)
Short-beaked common dolphins (California/Oregon/Washington stock)
are the most abundant cetacean off of California and are widely
distributed between the coast and approximately 556 km offshore. In
contrast, long-beaked common dolphins (California stock) are considered
a nearshore species and generally occur within 92.6 km of shore. Both
stocks may shift their distributions seasonally and annually in
response to oceanographic conditions and prey availability (Carretta et
al., 2023). Long-beaked common dolphins tend to prefer shallower,
warmer waters as compared to the short-beaked common dolphin (Perrin,
2009), yet both stocks appear to be more abundant in coastal waters
during warm-water months (Bearzi, 2005).
While there is no occurrence data for common dolphin in Oceanside
Harbor, they are rare visitors to the northern portion of San Diego Bay
and could be expected to be rare visitors within the outer portion of
Oceanside Harbor.
Pacific White-Sided Dolphin
Pacific white-sided dolphins (California stock) are endemic to
temperate waters of the North Pacific Ocean, and are the most abundant
pelagic species of dolphin in the region (Carretta et al., 2023). Off
the U.S. West Coast, Pacific white-sided dolphins occur primarily in
shelf and slope waters. Sighting patterns from aerial and shipboard
surveys conducted in California, Oregon, and Washington suggest
seasonal north-south movements, with animals found primarily off
California during colder water months and shifting northward into
Oregon and Washington as water temperatures increase in late spring and
summer (Green et al., 1992, Green et al., 1993, Forney and Barlow,
1998, Carretta et al., 2023). Pacific white-sided dolphins are highly
social and commonly occur in groups of less than a hundred, although
groups of several thousands of individuals have been observed. They
often associate with Risso's dolphins and short-beaked common dolphins,
and occasionally feed in association with California sea lions and
mixed species aggregations of seabirds.
No data of Pacific white-sided dolphin occurrence within Oceanside
Harbor exists but, as they do occur in the waters of southern
California, they could enter the outer portion of Oceanside Harbor.
California Sea Lion
California sea lions occur from Vancouver Island, British Columbia,
to the southern tip of Baja California, Mexico. Habitat use and
distribution varies with sex and reproductive stage, and sea lions
breed on the offshore islands of southern California, western Baja
California, and the Gulf of California from May through July (Heath and
Perrin, 2009, Lowry et al., 2017). Adult males may haul out on land to
breed and defend territory from mid-May through late July. Adult males
and females are known to haul out more often during warm-water months.
California sea lions are commonly seen in the proposed project area
and generally in and around Oceanside Harbor on a pinniped haulout
float, buoys, rocks, and other structures throughout the harbor (Merkel
and Associates, Inc., 2023). Beyond these structures, there are no
known natural haulout locations near the proposed action area.
Abundance in the proposed project area varies substantially through
[[Page 83086]]
time, with variability also being driven by food availability and
breeding season movements (pers. comm. Oceanside Harbor Department).
California sea lions in Oceanside Harbor are typically concentrated
around the pinniped float approximately 21 m north of the end of the
existing fishing pier in the proposed project area. This structure was
installed several years ago to attract sea lions away from docks and
boats (see Figure 2-1 in application). The Harbor Department noted that
the pinniped float varies from being completely full (approximately 100
animals or more) to completely empty. Prior to in-water activity, the
pinniped float would be relocated by the Oceanside Harbor Department
when no sea lions or other marine mammals are present to minimize
attraction of sea lions to the proposed work area during construction.
California sea lions experienced an Unusual Mortality Event (UME),
not correlated to an El Ni[ntilde]o event, from 2013-2017 (Carretta et
al., 2023). Pup and juvenile age classes experienced high mortality
during this time, likely attributed to a lack of prey availability,
specifically Pacific sardines (Sardinops sagax). California sea lions
are also susceptible to the algal neurotoxin domoic acid (Carretta et
al., 2023), which is expected to cause future mortalities among
California sea lions due to the prevalence of harmful algal blooms
within their habitat, as evidenced by recent stranding events along
parts of the Southern California coast in summer 2023.
Harbor Seal
Harbor seals are distributed from Baja California, Mexico, to the
eastern Aleutian Islands of Alaska (Harvey and Goley, 2011). Harbor
seals do not make extensive pelagic migrations but may travel hundreds
of kilometers to find food or suitable breeding areas (Harvey and
Goley, 2011, Carretta et al., 2023). Seals primarily haul out on remote
mainland and island beaches, reefs, and estuary areas. At haulout
sites, they congregate to rest, socialize, breed, and molt. In
California, there are approximately 500 haulout sites along the
mainland and on offshore islands, including intertidal sandbars, rocky
shores, and beaches (Hanan, 1996, Lowry et al., 2008).
Harbor seals are present within Oceanside Harbor, primarily in the
outer surge basin and not typically within the inner harbor (Merkel and
Associates, Inc., 2023). Harbor seals may haul out on the pinniped
float, rocks, buoys, or other structures within the harbor.
Northern Elephant Seal
Northern elephant seals breed and give birth in California and Baja
California, mainly on offshore islands during the months of December
through March (Stewart and Huber, 1993, Stewart et al., 1994, Carretta
et al., 2023). Molting season takes place from March to August. In
between the spring/summer molting season and winter breeding season,
northern elephant seals migrate north, exhibiting spatial segregation
in foraging areas in the Gulf of Alaska, western Aleutian Islands, and
central North Pacific Ocean to feeding grounds (Carretta et al., 2023).
Northern elephant seal populations in the United States and Mexico have
recovered after being hunted to near extinction (Stewart et al., 1994)
and undergoing a severe population bottleneck, leading to a loss of
genetic diversity, that resulted in the population being reduced to an
estimated 10-30 individuals (Hoelzel et al., 2002, Carretta et al.,
2023). There are two distinct populations of northern elephant seals,
including a breeding population in Baja California, Mexico, and a
breeding population on U.S. islands off of California. Northern
elephant seals in the region could be from either population (Carretta
et al., 2023).
Northern elephant seals rarely occur in the Southern California
Bight and are not expected to occur in Oceanside Harbor. However, given
the species has been sighted along the southern California coast in
recent years, potentially due to the continuing long-term increase in
the population of northern elephant seals (Lowry et al., 2020), there
is a possibility of occurrence in the project area.
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) was retained. Marine mammal hearing
groups and their associated hearing ranges are provided in table 3.
Table 3--Marine Mammal Hearing Groups
[NMFS, 2018]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans (dolphins, 150 Hz to 160 kHz.
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) (true 50 Hz to 86 kHz.
seals).
Otariid pinnipeds (OW) (underwater) (sea 60 Hz to 39 kHz.
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).
[[Page 83087]]
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).
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
This section provides a discussion of the ways in which components
of the specified activity may impact marine mammals and their habitat.
The Estimated Take of Marine Mammals section later in this document
includes a quantitative analysis of the number of individuals that are
expected to be taken by this activity. The Negligible Impact Analysis
and Determination section considers the content of this section, the
Estimated Take of Marine Mammals section, and the Proposed Mitigation
section, to draw conclusions regarding the likely impacts of these
activities on the reproductive success or survivorship of individuals
and whether those impacts are reasonably expected to, or reasonably
likely to, adversely affect the species or stock through effects on
annual rates of recruitment or survival.
Acoustic effects on marine mammals during the specified activities
can occur from impact pile driving and vibratory pile driving and
removal. The effects of underwater noise from the City of Oceanside's
proposed activities have the potential to result in Level B harassment
of marine mammals in the project area.
Description of Sound Sources
The marine soundscape is comprised of both ambient and
anthropogenic sounds. Ambient sound is defined as the all-encompassing
sound in a given place and is usually a composite of sound from many
sources both near and far (ANSI, 1995). The sound level of an area is
defined by the total acoustical energy being generated by known and
unknown sources. These sources may include physical (e.g., waves, wind,
precipitation, earthquakes, ice, atmospheric sound), biological (e.g.,
sounds produced by marine mammals, fish, and invertebrates), and
anthropogenic sound (e.g., vessels, dredging, aircraft, construction).
The sum of the various natural and anthropogenic sound sources at
any given location and time--which comprise ``ambient'' or
``background'' sound--depends not only on the source levels (as
determined by current weather conditions and levels of biological and
shipping activity) but also on the ability of sound to propagate
through the environment. In turn, sound propagation is dependent on the
spatially and temporally varying properties of the water column and sea
floor, and is frequency-dependent. As a result of the dependence on a
large number of varying factors, ambient sound levels can be expected
to vary widely over both coarse and fine spatial and temporal scales.
Sound levels at a given frequency and location can vary by 10-20 dB
from day to day (Richardson et al., 1995). The result is that,
depending on the source type and its intensity, sound from the
specified activities may be a negligible addition to the local
environment or could form a distinctive signal that may affect marine
mammals.
In-water construction activities associated with the proposed
project would include vibratory pile extraction and vibratory pile
installation, and, potentially, impact pile installation. The sounds
produced by these activities fall into one of two general sound types:
impulsive and non-impulsive. Impulsive sounds (e.g., explosions, sonic
booms, impact pile driving) are typically transient, brief (less than 1
second), broadband, and consist of high peak sound pressure with rapid
rise time and rapid decay (ANSI, 1986, NIOSH, 1998, NMFS, 2018). Non-
impulsive sounds (e.g., machinery operations such as drilling or
dredging, vibratory pile driving, underwater chainsaws, and active
sonar systems) can be broadband, narrowband, or tonal, brief or
prolonged (continuous or intermittent), and typically do not have the
high peak sound pressure with raid rise/decay time that impulsive
sounds do (ANSI, 1995, NIOSH, 1998, NMFS, 2018). The distinction
between these two sound types is important because they have differing
potential to cause physical effects, particularly with regard to
hearing (e.g., Ward, 1997).
Two types of hammers would be used on this project, vibratory and,
if necessary, impact. Vibratory hammers install piles by vibrating them
and allowing the weight of the hammer to push them into the sediment.
Vibratory hammers produce non-impulsive, continuous sounds. Vibratory
hammering generally produces sound pressure levels (SPLs) 10-20 dB
lower than impact pile driving of the same-sized pile (Oestman et al.,
2009). Rise time is slower, reducing the probability and severity of
injury, and sound energy is distributed over a greater amount of time
(Nedwell and Edwards, 2002, Carlson et al., 2005). Impact hammers
operate by repeatedly dropping and/or pushing a heavy piston onto a
pile to drive the pile into the substrate. Sound generated by impact
hammers is considered impulsive.
The likely or possible impacts of the City of Oceanside's proposed
activities on marine mammals could be generated from both non-acoustic
and acoustic stressors. Potential non-acoustic stressors include the
physical presence of the equipment, vessels, and personnel; however, we
expect that any animals that approach the project site close enough to
be harassed due to the presence of equipment or personnel would be
within the Level B harassment zones from pile removal or driving and
would already be subject to harassment from the in-water activities.
Therefore, any impacts to marine mammals are expected to primarily be
acoustic in nature. Acoustic stressors are generated by heavy equipment
operation during pile driving activities (i.e., impact and vibratory
pile driving and removal).
Acoustic Impacts
The introduction of anthropogenic noise into the aquatic
environment from pile driving equipment is the primary means by which
marine mammals may be harassed from the City of Oceanside's specified
activities. In general, animals exposed to natural or anthropogenic
sound may experience physical and psychological effects, ranging in
magnitude from none to severe (Southall et al., 2007). Generally,
exposure to pile driving and removal and other construction noise has
the potential to result in auditory threshold shifts (TS) and
behavioral reactions (e.g., avoidance, temporary cessation of foraging
and vocalizing, changes in dive behavior). Exposure to anthropogenic
noise can also lead to non-observable physiological responses, such as
an increase in stress hormones. Additional noise in a marine mammal's
habitat can mask acoustic cues used by marine mammals to carry out
daily functions, such as communication and predator and prey detection.
The effects of pile driving and construction noise on marine mammals
are dependent on several factors including, but not limited to, sound
type (e.g., impulsive vs. non-impulsive), the species, age and sex
class (e.g., adult male vs. mother with calf), duration of exposure,
the distance between the pile and the animal, received levels, behavior
at time of exposure, and previous history with exposure (Wartzok et
al., 2004, Southall et al., 2007). Here we discuss physical auditory
effects (threshold shifts)
[[Page 83088]]
followed by behavioral effects and potential impacts on habitat.
NMFS defines a noise-induced TS as a change, usually an increase,
in the threshold of audibility at a specified frequency or portion of
an individual's hearing range above a previously established reference
level (NMFS, 2018). The amount of TS is customarily expressed in dB and
TS can be permanent or temporary. As described in NMFS (2018), there
are numerous factors to consider when examining the consequence of TS,
including, but not limited to, the signal temporal pattern (e.g.,
impulsive or non-impulsive), likelihood an individual would be exposed
for a long enough duration or to a high enough level to induce a TS,
the magnitude of the TS, time to recovery (seconds to minutes or hours
to days), the frequency range of the exposure (i.e., spectral content),
the hearing and vocalization frequency range of the exposed species
relative to the signal's frequency spectrum (i.e., how animal uses
sound within the frequency band of the signal) (Kastelein et al.,
2014b), and the overlap between the animal and the source (e.g.,
spatial, temporal, and spectral).
Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent,
irreversible increase in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS, 2018). Available data
from humans and other terrestrial mammals indicate that a 40 dB TS
approximates PTS onset (see Ward et al., 1958, Ward et al., 1959, Ward,
1960, Kryter et al., 1966, Miller, 1974, Ahroon et al., 1996, Henderson
et al., 2008). PTS levels for marine mammals are estimates because
there are limited empirical data measuring PTS in marine mammals (e.g.,
Kastak et al., 2008), largely due to the fact that, for various ethical
reasons, experiments involving anthropogenic noise exposure at levels
inducing PTS are not typically pursued or authorized (NMFS, 2018).
Temporary Threshold Shift (TTS)--TTS is a temporary, reversible
increase in the threshold of audibility at a specified frequency or
portion of an individual's hearing range above a previously established
reference level (NMFS, 2018). Based on data from cetacean TTS
measurements (see Southall et al., 2007), a TTS of 6 dB is considered
the minimum TS clearly larger than any day-to-day or session-to-session
variation in a subject's normal hearing ability (Schlundt et al., 2000,
Finneran et al., 2000, FInneran et al., 2002). As described in Finneran
(2016), marine mammal studies have shown the amount of TTS increases
with cumulative sound exposure level (SEL<INF>cum</INF>) in an
accelerating fashion: At low exposures with lower SEL<INF>cum</INF>,
the amount of TTS is typically small and the growth curves have shallow
slopes. At exposures with higher SEL<INF>cum</INF>, the growth curves
become steeper and approach linear relationships with the noise SEL.
Depending on the degree (elevation of threshold in dB), duration
(i.e., recovery time), and frequency range of TTS, and the context in
which it is experienced, TTS can have effects on marine mammals ranging
from discountable to serious (similar to those discussed in auditory
Masking, below). For example, a marine mammal may be able to readily
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal
is traveling through the open ocean, where ambient noise is lower and
there are not as many competing sounds present. Alternatively, a larger
amount and longer duration of TTS sustained during time when
communication is critical for successful mother/calf interactions could
have more serious impacts. We note that reduced hearing sensitivity as
a simple function of aging has been observed in marine mammals, as well
as humans and other taxa (Southall et al., 2007), so we can infer that
strategies exist for coping with this condition to some degree, though
likely not without cost.
Currently, TTS data only exist for four species of cetaceans
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor
porpoise (Phocoena phocoena), Yangtze finless porpoise (Neophocoena
asiaeorientalis)) and five species of pinnipeds exposed to a limited
number of sound sources (i.e., tones and octave-band noise) in
laboratory settings (Finneran, 2015). TTS was not observed in trained
spotted seals (Phoca largha) and ringed seals (Pusa hispida) exposed to
impulsive noise at levels matching previous predictions of TTS onset
(Reichmuth et al., 2016). In general, harbor seals and harbor porpoises
have a lower TTS onset than other measured pinniped or cetacean species
(Finneran, 2015). At low frequencies, onset-TTS exposure levels are
higher compared to those in the region of best sensitivity (i.e., a low
frequency noise would need to be louder to cause TTS onset when TTS
exposure level is higher), as shown for harbor porpoises and harbor
seals (Kastelein et al., 2019b, Kastelein et al., 2019a, Kastelein et
al., 2020a, Kastelein et al., 2020b). In addition, TTS can accumulate
across multiple exposures but the resulting TTS will be less than the
TTS from a single, continuous exposure with the same SEL (Mooney et
al., 2009, Finneran et al., 2010, Kastelein et al., 2014a, Kastelein et
al., 2015). This means that TTS predictions based on the total
SEL<INF>cum</INF> will overestimate the amount of TTS from intermittent
exposures such as sonars and impulsive sources.
The potential for TTS from impact pile driving exists. After
exposure to playbacks of impact pile driving sounds (rate 2,760
strikes/hour) in captivity, mean TTS increased from 0 dB after a 15
minute exposure to 5 dB after a 360 minute exposure; recovery occurred
within 60 minutes (Kastelein et al., 2016). Additionally, the existing
marine mammal TTS data come from a limited number of individuals within
these species. No data are available on noise-induced hearing loss for
mysticetes. Nonetheless, what we considered is the best available
science. For summaries of data on TTS in marine mammals or for further
discussion of TTS onset thresholds, please see Southall et al. (2007),
Southall et al. (2019), Finneran and Jenkins (2012), Finneran (2015),
and table 5 in NMFS (2018).
Proposed activities for this project include vibratory pile driving
and vibratory pile removal and, potentially, impact pile driving. There
would likely be pauses in activities producing the sound during each
day and, given these pauses and the fact that many marine mammals would
likely be moving through the project areas and not remaining for
extended periods of time, the potential for TS declines.
Behavioral Harassment--Exposure to noise from pile driving and
removal also has the potential to behaviorally disturb marine mammals.
Available studies show wide variation in response to underwater sound;
therefore, it is difficult to predict specifically how any given sound
in a particular instance might affect marine mammals perceiving the
signal. If a marine mammal does react briefly to an underwater sound by
changing its behavior or moving a small distance, the impacts of the
change are unlikely to be significant to the individual, let alone the
stock or population. However, if a sound source displaces marine
mammals from an important feeding or breeding area for a prolonged
period, impacts on individuals and populations could be significant
(e.g., Council, 2005, Lusseau and Bejder, 2007, Weilgart, 2007b).
Disturbance may result in changing durations of surfacing and
dives, number of blows per surfacing, or moving direction and/or speed;
[[Page 83089]]
reduced/increased vocal activities; changing/cessation of certain
behavioral activities (such as socializing or feeding); visible startle
response or aggressive behavior (such as tail/fluke slapping or jaw
clapping); or avoidance of areas where sound sources are located.
Pinnipeds may increase their haulout time, possibly to avoid in-water
disturbance (Thorson and Reyff, 2006). Behavioral responses to sound
are highly variable and context-specific and any reactions depend on
numerous intrinsic and extrinsic factors (e.g., species, state of
maturity, experience, current activity, reproductive state, auditory
sensitivity, time of day), as well as the interplay between factors
(e.g., Richardson et al., 1995, Wartzok et al., 2004, Southall et al.,
2007, Weilgart, 2007a, Archer et al., 2010, Southall et al., 2021).
Behavioral reactions can vary not only among individuals but also
within an individual depending on previous experience with a sound
source, context, and numerous other factors (Ellison et al., 2012), and
can vary depending on characteristics associated with the sound source
(e.g., whether it is moving or stationary, number of sources, distance
from the source). In general, pinnipeds seem more tolerant of, or at
least habituate more quickly to, potentially disturbing underwater
sound than do cetaceans, and generally seem to be less responsive to
exposure to industrial sound than most cetaceans. Please see Appendices
B and C of Southall et al. (2007) as well as Nowacek et al. (2007),
Ellison et al. (2012), and Gomez et al. (2016) for a review of studies
involving marine mammal behavioral responses to sound.
Disruption of feeding behavior can be difficult to correlate with
anthropogenic sound exposure, so it is usually inferred by observed
displacement from known foraging areas, the appearance of secondary
indicators (e.g., bubble nets or sediment plumes), or changes in dive
behavior. As for other types of behavioral response, the frequency,
duration, and temporal pattern of signal presentation, as well as
differences in species sensitivity, are likely contributing factors to
differences in response in any given circumstance (e.g., Croll et al.,
2001, Nowacek et al., 2004, Madsen et al., 2006, Yazvenko et al., 2007,
Melcon et al., 2012). In addition, behavioral state of the animal plays
a role in the type and severity of a behavioral response, such as
disruption to foraging (e.g., Sivle et al., 2016, Wensveen et al.,
2017). A determination of whether foraging disruptions incur fitness
consequences would require information on, or estimates of, the
energetic requirements of the affected individuals and the relationship
between prey availability, foraging effort and success, and the life
history stage of the animal (Goldbogen et al., 2013).
Stress responses--An animal's perception of a threat may be
sufficient to trigger stress responses consisting of some combination
of behavioral responses, autonomic nervous system responses,
neuroendocrine responses, or immune responses (e.g., Selye, 1950,
Moberg, 2000). In many cases, an animal's first and sometimes most
economical (in terms of energetic costs) response is behavioral
avoidance of the potential stressor. Autonomic nervous system responses
to stress typically involve changes in heart rate, blood pressure, and
gastrointestinal activity. These responses have a relatively short
duration and may or may not have a significant long-term effect on an
animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that
are affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been
implicated in failed reproduction, altered metabolism, reduced immune
competence, and behavioral disturbance (e.g., Moberg, 1987, Blecha,
2000). Increases in the circulation of glucocorticoids are also equated
with stress (Romano et al., 2004).
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and ``distress'' is the cost of
the response. During a stress response, an animal uses glycogen stores
that can be quickly replenished once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other functions. This state of
distress will last until the animal replenishes its energetic reserves
sufficient to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well-studied through
controlled experiments for both laboratory and free-ranging animals
(e.g., Holberton et al., 1996, Hood et al., 1998, Jessop et al., 2003,
Krausman et al., 2004, Lankford et al., 2005). Stress responses due to
exposure to anthropogenic sounds or other stressors and their effects
on marine mammals have also been reviewed (Fair and Becker, 2000,
Romano et al., 2002b) and, more rarely, studied in wild populations
(e.g., Romano et al., 2002a). For example, Rolland et al. (2012) found
that noise reduction from reduced vessel traffic in the Bay of Fundy
was associated with decreased stress in North Atlantic right whales
(Eubalaena glacialis). These and other studies lead to a reasonable
expectation that some marine mammals will experience physiological
stress responses upon exposure to acoustic stressors and that it is
possible that some of these would be classified as ``distress.'' In
addition, any animal experiencing TTS would likely also experience
stress responses (NRC, 2003), however, distress is an unlikely result
of the proposed project based on observations of marine mammals during
previous, similar projects in the region.
Masking--Sound can disrupt behavior through masking, or interfering
with, an animal's ability to detect, recognize, or discriminate between
acoustic signals of interest (e.g., those used for intraspecific
communication and social interactions, prey detection, predator
avoidance, navigation) (Richardson et al., 1995). Masking occurs when
the receipt of a sound is interfered with by another coincident sound
at similar frequencies and at similar or higher intensity, and may
occur whether the sound is natural (e.g., snapping shrimp, wind, waves,
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar,
seismic exploration) in origin. The ability of a noise source to mask
biologically important sounds depends on the characteristics of both
the noise source and the signal of interest (e.g., signal-to-noise
ratio, temporal variability, direction), in relation to each other and
to an animal's hearing abilities (e.g., sensitivity, frequency range,
critical ratios, frequency discrimination, directional discrimination,
age or TTS hearing loss), and existing ambient noise and propagation
conditions. Masking of natural sounds can result when human activities
produce high levels of background sound at frequencies important to
marine mammals. Conversely, if the background level of underwater sound
is high (e.g., on a day with strong wind and high waves), an
anthropogenic sound source would not be detectable as far away as would
be possible under quieter conditions and would itself be masked. The
masking of communication signals by anthropogenic noise may be
considered as a reduction in the
[[Page 83090]]
communication space of animals (e.g., Clark et al., 2009) and may
result in energetic or other costs as animals change their vocalization
behavior (e.g., Miller et al., 2000, Foote et al., 2004, Parks et al.,
2007, Di Iorio and Clark, 2010, Holt et al., 2009). Oceanside Harbor is
used by commercial and recreational vessels, and background sound
levels in the area are already elevated. Due to the transient nature of
marine mammals to move and avoid disturbance, masking is not likely to
have long-term impacts on marine mammal species within the proposed
project area.
Airborne Acoustic Effects--Pinnipeds that occur near the project
site could be exposed to airborne sounds associated with pile driving
and removal that have the potential to cause behavioral harassment,
depending on their distance from piling activities. Cetaceans are not
expected to be exposed to airborne sounds that would result in
harassment as defined under the MMPA.
Airborne noise would primarily be an issue for pinnipeds that are
swimming or hauled out near the project site within the range of noise
levels elevated above the acoustic criteria. We recognize that
pinnipeds in the water could be exposed to airborne sound that may
result in behavioral harassment when looking with their heads above
water. Most likely, airborne sound would cause behavioral responses
similar to those discussed above in relation to underwater sound. For
instance, anthropogenic sound could cause hauled out pinnipeds to
exhibit changes in their normal behavior, such as reduction in
vocalizations, or cause them to temporarily abandon the area and move
further from the source. However, these animals would likely previously
have been ``taken'' because of exposure to underwater sound above the
behavioral harassment thresholds, which are generally larger than those
associated with airborne sound. Thus, the behavioral harassment of
these animals is already accounted for in these estimates of potential
take. Therefore, we do not believe that authorization of incidental
take resulting from airborne sound for pinnipeds is warranted, and
airborne sound is not discussed further.
Marine Mammal Habitat Effects
The City of Oceanside's proposed construction activities could have
localized, temporary impacts on marine mammal habitat, including prey,
by increasing in-water SPLs and slightly decreasing water quality.
Increased noise levels may affect acoustic habitat (see Masking above)
and adversely affect marine mammal prey in the vicinity of the project
area (see discussion below). During impact and vibratory pile driving
or removal, elevated levels of underwater noise would ensonify the
project area where both fishes and mammals occur and could affect
foraging success. Additionally, marine mammals may avoid the area
during construction, however, displacement due to noise is expected to
be temporary and is not expected to result in long-term effects to the
individuals or populations. Construction activities are expected to be
of short duration (6 non-consecutive days) and would likely have
temporary impacts on marine mammal habitat through increases in
underwater and airborne sound.
A temporary and localized increase in turbidity near the seafloor
would occur in the immediate area surrounding the area where piles are
installed or removed, for example, if high-pressure water jetting is
used. In general, turbidity associated with pile driving is localized
to an approximately 7.6 m radius around the pile (Everitt et al.,
1980). Cetaceans are not expected to be close enough to the pile
driving areas to experience effects of turbidity, and any pinnipeds
could avoid localized areas of turbidity. Therefore, we expect the
impact from increased turbidity levels to be discountable to marine
mammals and do not discuss it further.
In-Water Construction Effects on Potential Foraging Habitat--The
area likely impacted by the proposed action is relatively small
compared to the total available habitat in the area within and outside
the harbor. The proposed project area is highly influenced by
anthropogenic activities and provides limited foraging habitat for
marine mammals. Furthermore, pile driving and removal at the proposed
project site would not obstruct long-term movements or migration of
marine mammals.
Avoidance of the immediate area by potential prey (i.e., fish) due
to the temporary loss of foraging habitat is also possible. The
duration of fish and marine mammal avoidance of this area after pile
driving stops is unknown but a rapid return to normal recruitment,
distribution, and behavior is anticipated. Any behavioral avoidance by
prey of the disturbed area would still leave significantly large areas
of potential foraging habitat in the nearby vicinity, primarily outside
the harbor.
In-water Construction Effects on Potential Prey--Sound may affect
marine mammals through impacts on the abundance, behavior, or
distribution of prey species (e.g., crustaceans, cephalopods, fish,
zooplankton, other marine mammals). Marine mammal prey varies by
species, season, and location. Here, we describe studies regarding the
effects of noise on known marine mammal prey.
Fish utilize the soundscape and components of sound in their
environment to perform important functions such as foraging, predator
avoidance, mating, and spawning (Zelick et al., 1999, Fay, 2009).
Depending on their hearing anatomy and peripheral sensory structures,
which vary among species, fishes hear sounds using pressure and
particle motion sensitivity capabilities and detect the motion of
surrounding water (Fay et al., 2008). The potential effects of noise on
fishes depends on the overlapping frequency range, distance from the
sound source, water depth of exposure, and species-specific hearing
sensitivity, anatomy, and physiology. Key impacts to fishes may include
behavioral responses, hearing damage, barotrauma (pressure-related
injuries), and mortality.
Fish react to sounds which are especially strong and/or
intermittent low-frequency sounds, and behavioral responses such as
flight or avoidance are the most likely effects. Short duration, sharp
sounds can cause overt or subtle changes in fish behavior and local
distribution. The reaction of fish to noise depends on the
physiological state of the fish, past exposures, motivation (e.g.,
feeding, spawning, migration), and other environmental factors.
Hastings and Popper (2005) identified several studies that suggest fish
may relocate to avoid certain areas of sound energy. Additional studies
have documented effects of pile driving on fish, several of which are
based on studies in support of large, multiyear bridge construction
projects (e.g., Scholik and Yan, 2001, Popper and Hastings, 2009). Many
studies have demonstrated that impulse sounds might affect the
distribution and behavior of some fishes, potentially impacting
foraging opportunities or increasing energetic costs (e.g., Pearson et
al., 1992, Skalski et al., 1992, Santulli et al., 1999, Fewtrell and
McCauley, 2012, Paxton et al., 2017). In response to pile driving,
Pacific sardines and northern anchovies (Engraulis mordax) may exhibit
an immediate startle response to individual strikes but return to
``normal'' pre-strike behavior following the conclusion of pile driving
with no evidence of injury as a result (see NAVFAC, 2014). However,
some studies have shown no or slight reaction to impulse sounds (e.g.,
Wardle et al., 2001, Popper et al., 2005, Jorgenson and Gyselman, 2009,
Pe[ntilde]a et al., 2013).
[[Page 83091]]
SPLs of sufficient strength have been known to cause injury to fish
and fish mortality. However, in most fish species, hair cells in the
ear continuously regenerate and loss of auditory function likely is
restored when damaged cells are replaced with new cells. Halvorsen et
al. (2012b) showed that a TTS of 4-6 dB was recoverable within 24 hours
for one species. Impacts would be most severe when the individual fish
is close to the source and when the duration of exposure is long.
Injury caused by barotrauma can range from slight to severe and can
cause death, and is most likely for fish with swim bladders. Barotrauma
injuries have been documented during controlled exposure to impact pile
driving (Halvorsen et al., 2012a, Casper et al., 2013) and the greatest
potential effect on fish during the proposed project would occur during
impact pile driving, if it is required. However, the duration of impact
pile driving would be limited to a contingency in the event that
vibratory driving does not satisfactorily install the pile depending on
observed soil resistance. In-water construction activities would only
occur during daylight hours allowing fish to forage and transit the
project area at night. Vibratory pile driving may elicit behavioral
reactions from fish such as temporary avoidance of the area but is
unlikely to cause injuries to fish or have persistent effects on local
fish populations. In addition, it should be noted that the area in
question is low-quality habitat since it is already developed and
experiences anthropogenic noise from vessel traffic.
The most likely impact to fishes from pile driving and removal and
construction activities at the project area would be temporary
behavioral avoidance of the area. The duration of fish avoidance of
this area after pile driving stops is unknown but a rapid return to
normal recruitment, distribution, and behavior is anticipated. In
general, impacts to marine mammal prey species are expected to be minor
and temporary. Further, it is anticipated that preparation activities
for pile driving or removal (i.e., positioning of the hammer) and upon
initial startup of devices would cause fish to move away from the
affected area where injuries may occur. Therefore, relatively small
portions of the proposed project area would be affected for short
periods of time, and the potential for effects on fish to occur would
be temporary and limited to the duration of sound-generating
activities.
In summary, given the short daily duration of sound associated with
individual pile driving events and the relatively small area being
affected, pile driving activities associated with the proposed action
are not likely to have a permanent, adverse effect on any fish habitat
or populations of fish species. Any behavioral avoidance by fish of the
disturbed area would still leave significantly large potential areas
for fish and marine mammal foraging in the nearby vicinity. Thus, we
conclude that impacts of the specified activities are not likely to
have more than short-term adverse effects on any prey habitat or
populations of prey species. Further, any impacts to marine mammal
habitat are not expected to result in significant or long-term
consequences for individual marine mammals, or to contribute to adverse
impacts on their populations.
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
proposed for authorization through this IHA, which will inform both
NMFS' consideration of ``small numbers,'' and the negligible impact
determinations.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes would be by Level B harassment only in the form of
disruption of behavioral patterns for individual marine mammals
resulting from exposure to the acoustic sources. Based on the nature of
the activity and the anticipated effectiveness of the mitigation
measures (i.e., shutdown) discussed in detail below in the Proposed
Mitigation section, Level A harassment is neither anticipated nor
proposed to be authorized.
As described previously, no serious injury or mortality is
anticipated or proposed to be authorized for this activity. Below we
describe how the proposed 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 proposed 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 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, Southall et al., 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
[[Page 83092]]
likely takes by 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 (e.g., conspecific
communication, predators, prey) may result in changes in behavior
patterns that would not otherwise occur.
The City of Oceanside's proposed construction activities includes
the use of continuous (vibratory pile removal and installation) and,
potentially, impulsive (impact pile installation) sources, and
therefore the RMS SPL thresholds of 120 and 160 dB re 1 [mu]Pa are both
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
of Oceanside's proposed activity includes the use of impulsive (impact
hammer) and non-impulsive (vibratory hammer) sources.
These thresholds are provided in table 4, 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 4--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB..
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB..
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB..
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 218 dB; Cell 8: LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB..
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
LE,OW,24h: 203 dB..
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
has a reference value of 1[mu]Pa\2\s. In this table, thresholds are abbreviated to reflect American National
Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
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 (TL)
coefficient.
Pile driving activities using an impact hammer as well as a
vibratory hammer would generate underwater noise that could result in
disturbance to marine mammals near the project area. A review of
underwater sound measurements for similar projects was conducted to
estimate the near-source sound levels for impact and vibratory pile
driving and vibratory extraction. Source levels for proposed removal
and installation activities derived from this review are shown in table
5.
Table 5--Project Sound Source Levels
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pile size (inch, Peak SPL dB re RMS SPL dB re SEL dB re 1
Activity Method material) 1 [mu]Pa \1\ 1 [mu]Pa \1\ [mu]Pa \1\ Source
--------------------------------------------------------------------------------------------------------------------------------------------------------
Extraction......................... Vibratory............ 16, concrete \2\..... N/A 163 N/A NAVFAC SW, 2022.
Installation....................... Vibratory............ 18, steel............ 196 158 N/A Caltrans, 2020.
Installation....................... Impact............... 18, steel \3\........ 200 185 175 Caltrans, 2020.
Installation....................... Vibratory............ 10, steel \4\........ 171 155 N/A Illingworth and
Rodkin, 2007.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: All 18-inch round steel piles will be installed using both vibratory and impact driving, therefore, the total number of 18-inch piles proposed for
use is 18. Use of 10-inch piles will be as temporary support, and will be driven and removed in the same day as the permanent 18-inch piles.
\1\ As measured, or calculated, at 10 m (33 ft).
\2\ Proxy source levels provided by NMFS from Pier 6 Replacement Project, San Diego Bay (NAVFAC SW, 2022).
\3\ Analysis of pooled reported data provided by NMFS (Caltrans, 2020).
\4\ In the absence of information on vibratory installation of 10-inch round steel piles, source data from 12-inch round steel piles (Illingworth and
Rodkin, 2007) was used as a proxy source level.
Level B Harassment Zone--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 topography. The general formula for underwater TL is:
TL = B * Log10 (R1/R2),
where:
TL = transmission loss in dB;
B = transmission loss coefficient;
R1 = the distance of the modeled SPL from the driven pile; and
R2 = the distance from the driven pile of the
[[Page 83093]]
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, known as practical spreading,
which is the most appropriate assumption for the City of Oceanside's
proposed activity in the absence of specific modeling and site-specific
information. Sound propagation in Oceanside Harbor is limited by
physical structures and substantial sound would be confined within the
harbor (see Figures 6-1, 6-2 in application). The Level A and Level B
harassment isopleths for the City of Oceanside's proposed activities
are shown in table 6.
Table 6--Distance to the Level A and Level B Harassment Thresholds for Proposed Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A Level A Level A Level B
Activity Method Pile size (inch, threshold for threshold for threshold for harassment
material) MF (m) PW (m) OW (m) zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Extraction........................... Vibratory............... 16, concrete........... 1.2 7.9 0.6 7,356
Installation......................... Vibratory............... 18, steel.............. 0.5 3.7 0.3 3,415
Installation......................... Impact.................. 18, steel.............. 11.7 176.7 12.9 100
Installation......................... Vibratory............... 10, steel.............. 0.2 1.3 0.1 2,154
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: for impact pile driving, the single strike SEL was used to calculate distances to Level A harassment thresholds.
Abbreviations: MF = mid-frequency cetaceans, PW = phocid pinnipeds, OW = otariid pinnipeds.
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 (i.e., vibratory and impact piling), 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
in tables 6 and 7. The isopleths generated by the User Spreadsheet used
the same TL coefficients as the Level B harassment isopleth
calculations, as indicated above for each activity type. Inputs used in
the User Spreadsheet (e.g., number of piles per day, duration and/or
strikes per pile) are presented in table 1. The maximum RMS SPL, SEL,
and peak SPL are reported in table 7. The cumulative SEL and peak SPL
were used to calculate Level A harassment isopleths for vibratory pile
driving and extraction activities, while the single strike SEL value
was used to calculate Level A harassment isopleths for impact pile
driving activity.
Table 7--Sound Levels Used for Predicting Underwater Sound Impacts
--------------------------------------------------------------------------------------------------------------------------------------------------------
Single strike
Activity Method Pile size (inch, Duration Peak SPL dB re RMS SPL dB re SEL dB re 1
material) (hours/day) 1 [mu]Pa 1 [mu]Pa [mu]Pa\2\ sec
--------------------------------------------------------------------------------------------------------------------------------------------------------
Extraction........................... Vibratory............... 16, concrete........... 1.67 N/A 163 N/A
Installation......................... Vibratory............... 18, steel.............. 1.67 196 158 N/A
Installation......................... Impact.................. 18, steel.............. 0.13 200 185 175
Installation......................... Vibratory............... 10, steel.............. 0.67 171 155 N/A
--------------------------------------------------------------------------------------------------------------------------------------------------------
Marine Mammal Occurrence
In this section we provide information about the occurrence of
marine mammals, including density or other relevant information which
will inform the take calculations.
Bottlenose Dolphin--Bottlenose dolphins can occur at any time of
year in the waters around Oceanside Harbor. Based on previous
monitoring (Merkel and Associates, Inc., 2022), an average of 6
bottlenose dolphins per day were observed with a maximum of 12
individuals being observed on a single day. This higher peak of 12
individuals was used to calculate Level B harassment for bottlenose
dolphin.
Common Dolphin--Common dolphins are generally abundant in the outer
coastal waters but are not known to occur regularly in Oceanside
Harbor. Based on marine mammal monitoring by NAVFAC SW (2015), during
El Ni[ntilde]o conditions an average of 8.5 common dolphins per day
(rounded to nine per day) were observed in northwest San Diego Bay.
This expected daily individual count was used to calculate the take by
Level B harassment for common dolphins within Oceanside Harbor as no
local data exists.
Pacific White-Sided Dolphin--Pacific white-sided dolphins are
commonly seen offshore of southern California but are not known to
occur regularly in Oceanside Harbor. Based on the observations
presented by NAVFAC SW (2015), during El Ni[ntilde]o conditions an
average of 0.3 Pacific white-sided dolphins per day (rounded to one per
day) were observed. This expected daily individual count was used to
calculate the Level B harassment for Pacific white-sided dolphins.
California Sea Lion--California sea lions are present in Oceanside
Harbor year-round and numbers vary considerably. The daily estimate
provided by the Oceanside Harbor Department is over 100 individuals.
Limited counts from photographs and
[[Page 83094]]
spot counts average approximately 50 individuals and are known to be
incomplete estimates. Based on the variability in the number of sea
lions present in the harbor, an estimate of 100 sea lions per day was
used to estimate take.
Harbor Seal--Based on marine mammal monitoring by NAVFAC SW (2015),
during El Ni[ntilde]o conditions an average of 2.5 harbor seals per day
(rounded to three per day) were observed. This expected daily
individual count was used to calculate the Level B harassment for
harbor seals in Oceanside Harbor.
Northern Elephant Seal--Due to increasing population size of
northern elephant seals, presence in the Southern California Bight is
considered a reasonable possibility (Carretta et al., 2023). Based on
marine mammal monitoring by NAVFAC SW (2015), an average of 0.1
northern elephant seals per day (rounded to one per day) were observed
during El Ni[ntilde]o conditions. This expected daily individual count
was used to calculate the Level B harassment for northern elephant
seals in Oceanside Harbor.
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 proposed for authorization.
No take by Level A harassment is proposed for any species of marine
mammal due to the small zone sizes for most taxa, and the low
likelihood that an animal would approach during in-water construction
or remain within the Level A harassment isopleth long enough to incur
PTS during the specified activities. Proposed shutdown zones would
encompass the extent of the estimated Level A harassment isopleths (180
m for phocid pinnipeds during impact driving, 15 m for all other
species and activities) and are expected to be effective at avoiding
Level A harassment for all species. Given the locations of Protected
Species Observers (PSOs) described in the Proposed Monitoring and
Reporting section, in conjunction with the City of Oceanside's proposed
shutdown mitigation measure, NMFS agrees that monitoring and shutdown
measures are likely to be successful at avoiding take by Level A
harassment.
Incidental take by Level B harassment was estimated for each
species by multiplying the expected average number of individuals per
day by the number of work days (6 days; table 8). Take estimates for
each species were calculated by multiplying the estimated site-specific
abundance of each species by the area of impact where noise levels
exceed acoustic thresholds for marine mammals during active each type
of piling activity (vibratory removal, vibratory driving, impact
driving) and pile size (16 inch concrete, 18 inch steel, 10 inch
steel). Estimated daily exposures for each species were based on
evaluation of the potential presence of each marine mammal species
using historical occurrence from Oceanside Harbor (Merkel and
Associates, Inc., 2022; Merkel and Associates, Inc., 2023).
Estimated Take = Expected Average Individuals per Day x Number of Work
Days
Due to a paucity of marine mammal occurrence data within Oceanside
Harbor, and with the probability of El Ni[ntilde]o conditions
persisting throughout 2024 (<a href="https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml">https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml</a>), four species of
marine mammal (common dolphin, Pacific white-sided dolphin, harbor
seal, northern elephant seal) that are unlikely to occur within a semi-
enclosed harbor environment were included to account for a potential
increase in occurrence that has been previously documented for those
species under similar climatological conditions (NAVFAC SW, 2015).
Table 8--Estimated Take by Level B Harassment Proposed for Authorization
----------------------------------------------------------------------------------------------------------------
Maximum
Expected estimated Estimated
Common name Scientific name Stock average Level B takes as a
individuals harassment percentage of
per day takes population
----------------------------------------------------------------------------------------------------------------
Bottlenose dolphin \1\....... Tursiops California 12 72 15.9
truncatus. Coastal.
Common dolphin (long-beaked) Delphinus California..... * 9 * 54 <1
\2\. capensis.
Common dolphin (short-beaked) Delphinus California/ * 9 * 54 <1
\2\. delphis. Oregon/
Washington.
Pacific white-sided dolphin Lagenorhynchus California/ 1 6 <1
\2\. obliquidens. Oregon/
Washington--No
rthern and
Southern.
California sea lion \3\...... Zalophus U.S............ 100 600 <1
californianus.
Harbor seal \2\.............. Phoca vitulina California..... 3 18 <1
richardii.
Northern elephant seal \2\... Mirounga California 1 6 <1
angustirostris. breeding.
----------------------------------------------------------------------------------------------------------------
\1\ Average daily counts based on observations during Oceanside Harbor Dredging 2022 Project Monitoring, rounded
up to nearest individual count (Merkel and Associates Inc., 2022).
\2\ Average daily counts based on observations during Year 2 of Navy Base Point Loma's Fuel Pier Replacement
Project Monitoring, rounded up to nearest individual count (NAVFAC SW, 2015).
\3\ Reported high estimate of sea lions observed on pinniped float by Oceanside Harbor District staff.
* A total of 54 takes are estimated and may be attributed to either long- or short-beaked common dolphin
species.
Proposed 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)).
[[Page 83095]]
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.
The City of Oceanside must ensure that construction supervisors and
crews, the monitoring team, and relevant staff/contractors are trained
prior to the start of all piling activities 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.
Timing Restrictions
All piling activities would be conducted during daylight hours,
generally between 45 minutes post-sunrise and 45 minutes pre-sunset.
All piling would occur in March 2024 and/or September 2024 through
February 2025, when the likelihood of ESA-listed California least tern
breeding and nesting in the work area is minimal, as proposed by the
City of Oceanside.
Protected Species Observers
The placement of PSOs during all pile driving activities (described
in the Proposed Monitoring and Reporting section) would ensure that the
entire shutdown zone is visible. Should environmental conditions
deteriorate such that the entire shutdown zone would not be visible
(e.g., fog, heavy rain), pile driving would be delayed until the PSO is
confident marine mammals within the shutdown zone could be detected.
PSOs would monitor the full shutdown zones and the Level B
harassment zones to the extent practicable. Monitoring zones provide
utility for observing by establishing monitoring protocols for areas
adjacent to the shutdown zones. Monitoring zones enable observers to be
aware of and communicate the presence of marine mammals in the project
areas outside the shutdown zones and thus prepare for a potential
cessation of activity should the animal enter the shutdown zone.
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 would observe the shutdown and
monitoring zones for a period of 30 minutes. The shutdown zone would 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 listed in table 9, pile driving activity would be
delayed or halted. If work ceases for more than 30 minutes, the pre-
activity monitoring of the shutdown zones would 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 Procedures for Impact Driving
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. If
impact pile driving is necessary to achieve required tip elevation,
City of Oceanside staff and/or contractors would 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 would 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.
Shutdown Zones
The City of Oceanside must establish shutdown zones for all pile
driving activities. The purpose of a shutdown zone is generally to
define an area within which shutdown of the activity would occur upon
sighting of a marine mammal (or in anticipation of an animal entering
the defined area). Shutdown zones would be based upon the Level A
harassment thresholds for each pile size/type and driving method where
applicable, as shown in table 6. During all in-water piling activities,
the City of Oceanside has proposed to implement a buffered 15 m
shutdown zone, with the exception of a 180 m shutdown zone for phocids
during the use of impact pile driving of 18-inch piles. These distances
exceed the estimated Level A harassment isopleths described in table 6.
Adherence to this expanded shutdown zone will avoid the potential for
the take of phocids by Level A harassment during impact pile driving.
For pile driving, the radii of the shutdown zones are rounded to the
next largest 10 m interval in comparison to the Level A harassment
isopleth for each activity type. If a marine mammal is observed
entering, or detected within, a shutdown zone during pile driving
activity, the activity must be stopped until there is visual
confirmation that the animal has left the zone or the animal is not
sighted for a period of 15 minutes. Proposed shutdown zones for each
activity type are shown in Table 9.
All marine mammals would 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 would continue and PSOs would document the animal's presence
within the estimated harassment zone.
Table 9--Proposed Shutdown and Harassment Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pile size (inch, Shutdown zone Shutdown zone Shutdown zone Harassment
Activity Method material) for MF (m) for PW (m) for OW (m) zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Extraction........................... Vibratory............... 16, concrete........... 15 15 15 7,360
Installation......................... Vibratory............... 18, steel.............. 15 15 15 3,420
Installation......................... Impact.................. 18, steel.............. 15 180 15 100
Installation......................... Vibratory............... 10, steel.............. 15 15 15 2,160
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 83096]]
Based on our evaluation of the City of Oceanside's proposed
measures, NMFS has preliminarily determined that the proposed
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.
Proposed Monitoring and Reporting
In order to issue an IHA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present while
conducting the activities. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
<bullet> Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the activity; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
<bullet> How anticipated responses to stressors impact either: (1)
long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
<bullet> Mitigation and monitoring effectiveness.
Visual Monitoring
Marine mammal monitoring must be conducted in accordance with the
conditions in this section and this IHA. Marine mammal monitoring
during pile driving activities would be conducted by two PSOs meeting
NMFS' standards and 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 would have prior experience performing
the duties of a PSO during construction activity pursuant to a NMFS-
issued incidental take authorization;
<bullet> Other PSOs may substitute other relevant experience,
education (degree in biological science or related field), or training
for prior experience performing the duties of a PSO during construction
activity pursuant to a NMFS-issued incidental take authorization;
<bullet> Where a team of three or more PSOs is required, a lead
observer or monitoring coordinator must be designated. The lead
observer must have prior experience performing the duties of a PSO
during construction activity pursuant to a NMFS-issued incidental take
authorization; and
<bullet> PSOs must be approved by NMFS prior to beginning any
activity subject to the IHA.
PSOs should 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 of Oceanside would have two PSOs stationed at the best
possible vantage points in the project area to monitor during all pile
driving activities. Monitoring would occur from elevated locations
along the shoreline where the entire shutdown zones are visible. PSOs
would be equipped with high quality binoculars for monitoring and
radios or cells phones for maintaining contact with work crews.
Monitoring would be conducted 30 minutes before, during, and 30 minutes
after all in-water construction activities. In addition, PSOs would
record all incidents of marine mammal occurrence, regardless of
distance from activity, and would document any behavioral reactions in
concert with distance from piles being driven or removed. Pile driving
activities include the time to install or remove a single pile or
series of piles, as long as the time elapsed between uses of the pile
driving equipment is no more than 30 minutes.
Reporting
The City of Oceanside will provide the following reporting as
necessary during active pile driving activities:
<bullet> The applicant will report any observed injury or mortality
as soon as feasible and in accordance with NMFS' standard reporting
guidelines. Reports will be made by phone (866-767-6114) and by email
(<a href="/cdn-cgi/l/email-protection#bfefed91f6ebef91f2d0d1d6cbd0cdd6d1d8eddacfd0cdcbccffd1d0dede91d8d0c9"><span class="__cf_email__" data-cfemail="5303017d1a07037d1e3c3d3a273c213a3d340136233c212720133d3c32327d343c25">[email protected]</span></a>) and will include the following:
[cir] Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
[cir] Species identification (if known) or description of the
animal(s) involved;
[cir] Condition of the animal(s) (including carcass condition if
the animal is dead);
[cir] Observed behaviors of the animal(s), if alive;
[cir] If available, photographs or video footage of the animal(s);
and
[cir] General circumstances under which the animal was discovered;
<bullet> An annual report summarizing the prior year's activities
will be provided that fully documents the methods and monitoring
protocols, summarizes the data recorded during monitoring, estimates
the number of listed marine mammals that may have been incidentally
taken during project pile driving, and provides an interpretation of
the results and effectiveness of all monitoring tasks. The annual draft
report will be provided no later than 90 days following completion of
construction activities. Any recommendations made by NMFS will be
addressed in the final report, due
[[Page 83097]]
after the IHA expires and including a summary of all monitoring
activities, prior to acceptance by NMFS. Final reports will follow a
standardized format for PSO reporting from activities requiring marine
mammal mitigation and monitoring; and
<bullet> All PSOs will use a standardized data entry format (see
Monitoring Plan).
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 2, given that the anticipated effects of
this activity on these different marine mammal stocks are expected to
be similar. There is little information about the nature or severity of
the impacts, or the size, status, or structure of any of these species
or stocks that would lead to a different analysis for this activity.
Level A harassment is extremely unlikely given the small size of
the Level A harassment isopleths and the required mitigation measures
designed to minimize the possibility of injury to marine mammals (see
Proposed Mitigation section). No mortality is anticipated given the
nature of the activity.
Pile installation and removal activities are likely to result in
the Level B harassment of marine mammals that move into the ensonified
zone, primarily in the form of disturbance or displacement of marine
mammals.
Take would occur within a limited, confined area of each stock's
range. 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.
No marine mammal stocks for which incidental take authorization is
proposed 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
proposed monitoring make injury takes of marine mammals unlikely. The
shutdown zones would be thoroughly monitored before the proposed
vibratory pile installation and removal begins, and construction
activities would be postponed if a marine mammal is sighted within the
shutdown zone. There is a high likelihood that marine mammals would be
detected by trained observers under environmental conditions described
for the proposed project. Limiting construction activities to daylight
hours would also increase detectability of marine mammals in the area.
Therefore, the proposed mitigation and monitoring measures are expected
to eliminate the potential for injury and Level A harassment as well as
reduce the amount and intensity for 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.
Anticipated and authorized takes are expected to be limited to
short-term Level B harassment (behavioral disturbance) as construction
activities will occur over the course of 5-6 months. Effects on
individuals taken by Level B harassment, based upon reports in the
literature as well as monitoring from other similar activities, may
include increased swimming speeds, increased surfacing time, or
decreased foraging (e.g., NAVFAC SW, 2018). Individual animals, even if
taken multiple times, would likely move away from the sound source and
be temporarily displaced from the area due to elevated noise level
during pile removal. Marine mammals could also experience TTS if they
move into the Level B harassment monitoring zone. TTS is a temporary
loss of hearing sensitivity when exposed to loud sound, and, given the
likely levels and duration of exposure to pile driving, any shift of
the hearing threshold is expected to recover completely within minutes
to hours. While TTS could occur, it is not considered a likely outcome
of this activity.
Given the limited number of total predicted exposures, no
individual marine mammals of any species, with the possible exception
of California sea lions, would be expected to be taken on more than a
few days during the construction activities. California sea lions are
relatively common in the area, and potential takes would likely involve
sea lions loafing on, or in the vicinity of, physical structures or
moving through the area en route to foraging areas or structures where
they haul out. Relocation of the float where they frequently haul out
is expected to reduce both the number of sea lions present in the area
during construction and also the likelihood that they may be repeatedly
impacted.
The proposed 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
the proposed activities would not permanently modify existing marine
mammal habitat. The activities may cause fish to leave the area
temporarily which could impact marine mammals' foraging opportunities
in a limited portion of the foraging range. However, due to the short
duration of the proposed 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 would 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
would therefore not result in population-level impacts.
In summary and as described above, the following factors primarily
support our preliminary determination that the
[[Page 83098]]
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, or Level A harassment, is
anticipated or authorized;
<bullet> The specified activities are of a very short duration and
associated ensonified areas are very small relative to the overall
habitat ranges of both species;
<bullet> The project area does not overlap with known BIAs or ESA-
designated critical habitat;
<bullet> Significant or long-term effects to marine mammal habitat
are not anticipated; and
<bullet> Proposed mitigation measures are expected to reduce the
effects of the specified activity to the level of least practicable
adverse impact.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS preliminarily finds that the total marine
mammal take from the proposed activity will have a negligible impact on
all affected marine mammal species or stocks.
Small Numbers
As noted previously, only take of small numbers of marine mammals
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is fewer than one-third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
The amount of take NMFS has authorized is below one-third of the
estimated stock abundances for all seven species (see table 8). For all
but one species, the proposed take of individuals is less than 1
percent of the abundance of the affected stock (with the exception for
bottlenose dolphins at less than 16 percent). This is likely a
conservative estimate because it assumes all takes are of different
individual animals, which is likely not the case. Some individuals may
return multiple times in a day, but PSOs would count them as separate
takes if they cannot be individually identified.
Based on the analysis contained herein of the proposed activity
(including the proposed mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS preliminarily finds that small
numbers of marine mammals would be taken relative to the population
size of the affected species or stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
determined that the total taking of affected species or stocks would
not have an unmitigable adverse impact on the availability of such
species or stocks for taking for subsistence purposes.
Endangered Species Act
Section 7(a)(2) of the 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 propose to authorize take for endangered or
threatened species.
No incidental take of ESA-listed species is proposed for
authorization or expected to result from this activity. Therefore, NMFS
has determined that formal consultation under section 7 of the ESA is
not required for this action.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to the City of Oceanside for conducting pile removal and
driving in Oceanside Harbor, Oceanside, CA, provided the previously
mentioned mitigation, monitoring, and reporting requirements are
incorporated. A draft of the proposed IHA can be found 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>.
Request for Public Comments
We request comment on our analyses, the proposed authorization, and
any other aspect of this notice of proposed IHA for the proposed
construction project. We also request comment on the potential renewal
of this proposed IHA as described in the paragraph below. Please
include with your comments any supporting data or literature citations
to help inform decisions on the request for this IHA or a subsequent
renewal IHA.
On a case-by-case basis, NMFS may issue a one-time, one-year
renewal IHA following notice to the public providing an additional 15
days for public comments when (1) up to another year of identical or
nearly identical activities as described in the Description of Proposed
Activity section of this notice is planned or (2) the activities as
described in the Description of Proposed Activity section of this
notice would not be completed by the time the IHA expires and a renewal
would allow for completion of the activities beyond that described in
the Dates and Duration section of this notice, provided all of the
following conditions are met:
<bullet> A request for renewal is received no later than 60 days
prior to the needed renewal IHA effective date (recognizing that the
renewal IHA expiration date cannot extend beyond one year from
expiration of the initial IHA); and
<bullet> The request for renewal must include the following:
(1) An explanation that the activities to be conducted under the
requested renewal IHA are identical to the activities analyzed under
the initial IHA, are a subset of the activities, or include changes so
minor (e.g., reduction in pile size) that the changes do not affect the
previous analyses, mitigation and monitoring requirements, or take
estimates (with the exception of reducing the type or amount of take);
and
(2) A preliminary monitoring report showing the results of the
required monitoring to date and an explanation showing that the
monitoring results do not indicate impacts of a scale or nature not
previously analyzed or authorized.
Upon review of the request for renewal, the status of the affected
species or stocks, and any other pertinent information, NMFS determines
that there are no more than minor changes in the activities, the
mitigation and monitoring measures will remain the same and
appropriate, and the findings in the initial IHA remain valid.
Dated: November 20, 2023.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2023-26158 Filed 11-27-23; 8:45 am]
BILLING CODE 3510-22-P
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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.