Notice2024-22394
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Army Corps of Engineers Baker Bay Pile Dike Repair Project
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
September 30, 2024
Effective
August 1, 2025
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
In accordance with the regulations implementing the Marine Mammal Protection Act (MMPA) as amended, notification is hereby given that NMFS has issued an incidental harassment authorization (IHA) to the Army Corps of Engineers (ACOE) to incidentally harass marine mammals during construction activities associated with the Baker Bay pile dike repair project in Baker Bay, Oregon. There are no changes from the proposed authorization in this final authorization.
Full Text
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<title>Federal Register, Volume 89 Issue 189 (Monday, September 30, 2024)</title>
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[Federal Register Volume 89, Number 189 (Monday, September 30, 2024)]
[Notices]
[Pages 79557-79568]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-22394]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XE225]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the Army Corps of Engineers Baker
Bay Pile Dike Repair Project
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of an incidental harassment authorization.
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SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued an incidental harassment authorization (IHA) to
the Army Corps of Engineers (ACOE) to incidentally harass marine
mammals during construction activities associated with the Baker Bay
pile dike repair project in Baker Bay, Oregon. There are no changes
from the proposed authorization in this final authorization.
DATES: This authorization is effective from August 1, 2025 to July 31,
2026.
ADDRESSES: Electronic copies of the application and supporting
documents, as well as a list of the references cited in this document,
may be obtained online at: <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-army-corps-engineers-baker-bay-pile-dike-repair-project-baker">https://www.fisheries.noaa.gov/action/incidental-take-authorization-army-corps-engineers-baker-bay-pile-dike-repair-project-baker</a>. In case of problems accessing these documents,
please call the contact listed below.
FOR FURTHER INFORMATION CONTACT: Craig Cockrell, Office of Protected
Resources, NMFS, (301) 427-8401.
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 monitoring and
reporting of the takings. The definitions of all applicable MMPA
statutory terms cited above are included in the relevant sections
below.
Summary of Request
On September 8, 2022, NMFS received a request from the ACOE for an
IHA to take marine mammals incidental to pile driving and removal at
the mouth of the Columbia River in Oregon. Following NMFS' review of
the application, the ACOE submitted two revised versions on March 4,
2024 and May 1, 2024. The application was deemed adequate and complete
on June 10, 2024. The ACOE's request is for take of eight species of
marine mammals by Level B harassment and, for harbor seal (Phoca
vitulina), Level A harassment. Neither ACOE nor NMFS expect serious
injury or mortality to result from this activity and, therefore, an IHA
is appropriate.
Description of Activity
ACOE is planning to conduct pile dike repairs in the Baker Bay
system, located in the Columbia River estuary. There are a variety of
activities that will occur during this project. Take of marine mammals
is expected to occur only during the construction of the material
offload facility and the installation of the marker piles. Vibratory
and impact pile driving will introduce underwater sounds that may
result in take, by Level A and Level B harassment, of marine mammals.
It is expected to take up to 12 non-consecutive days to complete the
pile driving activities from August through October.
A detailed description of the planned construction project is
provided in the Federal Register notice for the proposed IHA (89 FR
60385, July 25, 2024). Since that time, no changes have been made to
the planned activities. Therefore, a detailed description is not
provided here. Please refer to that Federal Register notice for the
description of the specific activity.
Comments and Responses
A notice of NMFS' proposal to issue an IHA to the ACOE was
published in the Federal Register on July 25, 2024 (89 FR 60385). That
notice described, in detail, the ACOE's activity, the marine mammal
species that may be affected by the activity, and the anticipated
effects on marine mammals. In that notice, we requested public input on
the request for authorization described therein, our analyses, the
proposed authorization, and any other aspect of the notice of proposed
IHA, and requested that interested persons submit relevant information,
suggestions, and comments. During the 30-day public comment period,
NMFS did not receive any public comments.
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history of the potentially affected species. NMFS
fully considered all of this information, and we refer the reader to
these descriptions, instead of reprinting the information. Additional
information regarding population trends and threats may be found in
NMFS' Stock Assessment Reports (SARs; <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>)
[[Page 79558]]
and more general information about these species (e.g., physical and
behavioral descriptions) may be found on NMFS' website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 1 lists all species or stocks for which take is expected and
authorized for this activity and summarizes information related to the
population or stock, including regulatory status under the MMPA and
Endanger Species Act (ESA) and potential biological removal (PBR),
where known. PBR is defined by the MMPA as the maximum number of
animals, not including natural mortalities, that may be removed from a
marine mammal stock while allowing that stock to reach or maintain its
optimum sustainable population (as described in NMFS' SARs). While no
serious injury or mortality is anticipated or authorized here, PBR and
annual serious injury and mortality from anthropogenic sources are
included here as gross indicators of the status of the species or
stocks and other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS' U.S. Pacific SARs. All values presented in table 1 are the most
recent available at the time of publication (including from the draft
2023 SARs) and are available online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>.
Table 1--Species Likely Impacted by the Specified Activities \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\2\ abundance survey) \3\ SI \4\
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Order Artiodactyla--Infraorder Cetacea--Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae (baleen
whale):
Gray Whale...................... Eschrichtius robustus.. Eastern N Pacific...... -, -, N 26,960 (0.05, 25,849, 801 131
2016).
Family Balaenopteridae (rorquals)
Humpback whale.................. Megaptera novaeangliae. Central America/ E, D, Y 1,494 (0.171, 1,284, 3.5 14.9
Southern Mexico--CA/OR/ 2021).
WA.
Mainland Mexico--CA/OR/ T, D, Y 3,477 (0.101, 3,185, 43 22
WA. 2018).
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Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
Killer whale.................... Orcinus orca........... West Coast Transient... -, -, N 349 (N/A, 349, 2018).. 3.5 0.4
Family Phocoenidae (porpoises):
Harbor porpoise................. Phocoena phocoena...... Northern OR/WA Coast... -, -, N 22,074 (0.391, 16,068, 161 3.2
2022).
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Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and
sea lions):
Steller sea lion................ Eumetopias jubatus..... Eastern DPS............ -, -, N 36,308 (N/A, 36,308, 2,178 93.2
2022).
California sea lion............. Zalophus californianus. U.S.................... -, -, N 257,606 (N/A, 233,515, 14,011 >321
2014).
Family Phocidae (earless seals):
Harbor seal..................... Phoca vitulina......... OR/WA Coastal.......... -, -, N UNK (UNK, UNK, 1999).. UND 10.6
Northern elephant seal.......... Mirounga angustirostris CA Breeding............ -, -, N 187,386 (N/A, 85,369, 5,122 13.7
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.
\2\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\3\ NMFS marine mammal stock assessment reports online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region</a>. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
A detailed description of the species likely to be affected by the
Baker Bay pile dike project, including brief introductions to the
species and relevant stocks as well as available information regarding
population trends and threats, and information regarding local
occurrence, were provided in the Federal Register notice for the
proposed IHA (89 FR 60385, July 25, 2024); since that time, we are not
aware of any changes in the status of these species and stocks;
therefore, detailed descriptions are not provided here. Please refer to
that Federal Register notice for these descriptions. Please also refer
to NMFS' website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>) for
generalized species accounts.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Not all marine mammal species have equal
hearing capabilities (e.g., Richardson et al. 1995; Wartzok and Ketten
1999; Au and Hastings 2008). To reflect this, Southall et al. (2007,
2019) recommended that marine mammals be divided into hearing groups
based on directly measured (behavioral or auditory evoked potential
techniques) or estimated hearing ranges
[[Page 79559]]
(behavioral response data, anatomical modeling, etc.). Subsequently,
NMFS (2018) described generalized hearing ranges for these marine
mammal hearing groups. Generalized hearing ranges were chosen based on
the approximately 65-decibel (dB) threshold from the normalized
composite audiograms, with the exception for lower limits for low-
frequency cetaceans where the lower bound was deemed to be biologically
implausible and the lower bound from Southall et al. (2007) retained.
Marine mammal hearing groups and their associated hearing ranges are
provided in table 2.
Table 2--Marine Mammal Hearing Groups
[NMFS, 2018]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans (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).
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
The effects of underwater noise from the ACOE's construction
activities have the potential to result in behavioral harassment of
marine mammals in the vicinity of the project area. The notice of
proposed IHA (89 FR 60385, July 25, 2024) included a discussion of the
effects of anthropogenic noise on marine mammals and the potential
effects of underwater noise from the ACOE's construction on marine
mammals and their habitat. That information and analysis is referenced
in this final IHA determination and is not repeated here; please refer
to the notice of proposed IHA (89 FR 60385, July 25, 2024).
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
authorized through the IHA, which will inform NMFS' consideration of
``small numbers,'' the negligible impact determinations, and impacts on
subsistence uses.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes will primarily be by Level B harassment, as use of
the construction equipment (i.e., pile driving) has the potential to
result in disruption of behavioral patterns for individual marine
mammals. There is also some potential for auditory injury (Level A
harassment) of phocids because predicted auditory injury zones are
larger than for other species. The mitigation and monitoring measures
are expected to minimize the severity of the taking to the extent
practicable.
As described previously, no serious injury or mortality is
anticipated or to be authorized for this activity. Below we describe
how the take numbers are estimated.
For acoustic impacts, generally speaking, we estimate take by
considering: (1) acoustic thresholds above which NMFS believes the best
available science indicates marine mammals will be behaviorally
harassed or incur some degree of permanent hearing impairment; (2) the
area or volume of water that will be ensonified above these levels in a
day; (3) the density or occurrence of marine mammals within these
ensonified areas; and, (4) the number of days of activities. We note
that while these factors can contribute to a basic calculation to
provide an initial prediction of potential takes, additional
information that can qualitatively inform take estimates is also
sometimes available (e.g., previous monitoring results or average group
size). Below, we describe the factors considered here in more detail
and present the take estimates.
Acoustic Thresholds
NMFS recommends the use of acoustic thresholds that identify the
received level of underwater sound above which exposed marine mammals
would be reasonably expected to be behaviorally harassed (equated to
Level B harassment) or to incur Permanent Threshold Shift (PTS) of some
degree (equated to Level A harassment).
Level B Harassment--Though significantly driven by received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source or exposure context (e.g., frequency, predictability, duty
cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., bathymetry, other noises in the area,
predators in the area), and the receiving animals (hearing, motivation,
experience, demography, life stage, depth) and can be difficult to
predict (e.g., Southall et al. 2007, 2021; Ellison et al. 2012). Based
on what the available science indicates and the practical need to use a
threshold based on a metric that is both predictable and measurable for
most activities, NMFS typically uses a generalized acoustic threshold
based on received level to estimate the onset of behavioral harassment.
NMFS generally predicts that marine mammals are likely to be
behaviorally harassed in a manner considered to be Level B harassment
when exposed to underwater anthropogenic noise above root-mean-
[[Page 79560]]
squared pressure received levels (RMS SPL) of 120 dB (referenced to 1
micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g.,
scientific sonar) sources. Generally speaking, Level B harassment take
estimates based on these behavioral harassment thresholds are expected
to include any likely takes by Temporary Threshold Shift (TTS) as, in
most cases, the likelihood of TTS occurs at distances from the source
less than those at which behavioral harassment is likely. TTS of a
sufficient degree can manifest as behavioral harassment, as reduced
hearing sensitivity and the potential reduced opportunities to detect
important signals (conspecific communication, predators, prey) may
result in changes in behavior patterns that will not otherwise occur.
The ACOE's construction includes the use of continuous (vibratory
pile driving) and impulsive (impact pile driving) sources, and
therefore the RMS SPL thresholds of 120 and 160 dB re 1 [mu]Pa are
applicable.
Level A Harassment--NMFS' Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0;
Technical Guidance 2018) identifies dual criteria to assess auditory
injury (Level A harassment) to five different marine mammal groups
(based on hearing sensitivity) as a result of exposure to noise from
two different types of sources (impulsive or non-impulsive). The ACOE's
construction includes the use of impulsive (impact pile driving) and
non-impulsive (vibratory pile driving) sources.
These thresholds are provided in the table below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS' 2018 Technical Guidance, which may be accessed at:
<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset 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.
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* 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[micro]Pa\2\s. In this table, thresholds are abbreviated to reflect American
National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
``flat'' is 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
coefficient.
The sound field in the project area is the existing background
noise plus additional construction noise from the project. Marine
mammals are expected to be affected via sound generated by the primary
components of the project (i.e., impact pile driving and vibratory pile
driving and removal). The maximum (underwater) area ensonified above
the thresholds for behavioral harassment referenced above is 20.72
km\2\ (12.87 mi\2\), and will consist of most of the mouth of the
Columbia River immediately south of West Sand Island (See figure 1 in
the proposed IHA 89 FR 60385, July 25, 2024). Additionally, vessel
traffic in the project area may contribute to elevated background noise
levels which may mask sounds produced by the project.
Transmission loss (TL) is the decrease in acoustic intensity as an
acoustic pressure wave propagates out from a source. TL parameters vary
with frequency, temperature, sea conditions, current, source and
receiver depth, water depth, water chemistry, and bottom composition
and topography. The general formula for underwater TL is:
TL = B x Log<INF>10</INF> (R<INF>1</INF>/R<INF>2</INF>),
where
TL = transmission loss in dB
B = transmission loss coefficient
R<INF>1</INF> = the distance of the modeled SPL from the driven
pile, and
R<INF>2</INF> = the distance from the driven pile of the initial
measurement
This formula neglects loss due to scattering and absorption, which
is assumed to be zero here. The degree to which underwater sound
propagates away from a sound source is dependent on a variety of
factors, most notably the water bathymetry and presence or absence of
reflective or absorptive conditions including in-water structures and
sediments. Spherical spreading occurs in a perfectly unobstructed
(free-field) environment not limited by depth or water surface,
resulting in a 6-dB reduction in sound level for each doubling of
distance from the source (20*log[range]). Cylindrical spreading occurs
in an environment in which sound propagation is bounded by the water
surface and sea bottom, resulting in a reduction of 3 dB in sound level
for each doubling of distance from the source (10*log[range]). A
practical spreading value of 15 is often used under conditions, such as
the project site, where water increases with depth as the receiver
moves away from the shoreline, resulting in an expected propagation
environment that will lie between spherical and cylindrical spreading
loss conditions. Practical spreading loss is assumed here.
The intensity of pile driving sounds is greatly influenced by
factors such as the
[[Page 79561]]
type of piles, hammers, and the physical environment in which the
activity takes place. In order to calculate the distances to the Level
A harassment and the Level B harassment sound thresholds for the
methods and piles being used in this project, the applicant and NMFS
used acoustic monitoring data from other locations to develop proxy
source levels for the various pile types, sizes and methods. The
project includes vibratory and impact pile installation of steel pipe
and sheet piles and vibratory removal of steel sheet piles. Source
levels for 24-in steel pipe piles are used as a proxy for all steel
piles that may be placed for marker piles of the dike system, though
smaller piles may be used during the construction. NMFS consulted
multiple sources to determine valid proxy source levels for the impact
installation of sheet piles, as indicated in table 4. This is the best
available data for sheet pile source levels and is based on 24-in sheet
piles used for a project in California. Source levels for each pile
size and driving method are presented in table 4.
Table 4--Proxy Sound Source Levels for Pile Sizes and Driving Methods
--------------------------------------------------------------------------------------------------------------------------------------------------------
Proxy source level (at 10 m)
--------------------------------------------------
Pile size Method dB RMS re dB SEL re dB peak re Literature source
1[micro]Pa 1[micro]Pa\2\sec 1[micro]Pa
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in................................. Vibratory................ 154 N/A N/A Navy 2015.
24-in sheet pile...................... Vibratory................ 160 N/A N/A Caltrans 2020.
24-in................................. Impact................... 189 178 203 Caltrans 2015.
--------------------------------------------------------------------------------------------------------------------------------------------------------
The ensonified area associated with Level A harassment is more
technically challenging to predict due to the need to account for a
duration component. Therefore, NMFS developed an optional User
Spreadsheet tool to accompany the Technical Guidance that can be used
to relatively simply predict an isopleth distance for use in
conjunction with marine mammal density or occurrence to help predict
potential takes. We note that because of some of the assumptions
included in the methods underlying this optional tool, we anticipate
that the resulting isopleth estimates are typically going to be
overestimates of some degree, which may result in an overestimate of
potential take by Level A harassment. However, this optional tool
offers the best way to estimate isopleth distances when more
sophisticated modeling methods are not available or practical. For
stationary sources such as impact or vibratory pile driving, the
optional User Spreadsheet tool predicts the distance at which, if a
marine mammal remained at that distance for the duration of the
activity, it would be expected to incur PTS. Inputs used in the
optional User Spreadsheet tool are reported below (table 5). The
resulting estimated Level A harassment isopleths and the Level B
harassment isopleths are reported in table 6.
Table 5--User Spreadsheet Inputs for Calculating Level A Harassment Isopleths
----------------------------------------------------------------------------------------------------------------
Weighting
Spreadsheet tab factor Number of Number of Activity
Pile size and installation method used adjustment strikes per piles per duration
(kHz) pile day (minutes)
----------------------------------------------------------------------------------------------------------------
24-in vibratory installation (MOF A.1 Vibratory pile 2.5 N/A 8 20
Option 2). driving.
24-in vibratory removal (MOF A.1 Vibratory pile 2.5 N/A 16 5
Option 2). driving.
24-in sheet pile vibratory A.1 Vibratory pile 2.5 N/A 25 15
installation (MOF Option 1). driving.
24-in sheet pile vibratory A.1 Vibratory pile 2.5 N/A 60 3
removal (MOF Option 1). driving.
24-in vibratory installation A.1 Vibratory pile 2.5 N/A 8 15
(Pile Markers). driving.
24-in impact installation (Pile E.1 Impact pile 2 225 5 N/A
Markers). driving.
----------------------------------------------------------------------------------------------------------------
Table 6--Calculated Level A and Level B Harassment Isopleths
----------------------------------------------------------------------------------------------------------------
Level A harassment zone (m)
---------------------------------------------------------- Level B
Activity LF- MF- HF- harassment
cetaceans cetaceans cetaceans Phocids Otariids zone (m)
----------------------------------------------------------------------------------------------------------------
24-in Steel Pipe Pile Vibratory Install 4.5 0.4 6.6 2.7 0.2 1,847.8
(MOF Option 2)..........................
24-in Steel Pipe Pile Vibratory Removal 2.8 0.3 4.2 1.7 0.1
(MOF Option 2)..........................
24-in sheet pile vibratory installation 23.4 2.1 34.6 14.2 1.0 4,641.1
(MOF Option 1)..........................
24-in sheet pile vibratory removal (MOF 12.2 1.1 18 7.4 0.5
Option 1)...............................
24-in vibratory installation (Pile 3.7 0.3 5.5 2.3 0.2 1,847.8
Markers)................................
24-in impact installation (Pile Markers). 501.4 17.8 597.2 268.3 19.5 857.7
----------------------------------------------------------------------------------------------------------------
[[Page 79562]]
Marine Mammal Occurrence and Take Estimation
In this section we provide information about the occurrence of
marine mammals, including density or other relevant information which
will inform the take calculations. We describe how the information
provided is synthesized to produce a quantitative estimate of the take
that is reasonably likely to occur and authorized.
When available, peer-reviewed scientific publications were used to
estimate marine mammal abundance in the project area. Data from
monitoring reports from the previous Sand Island Test Pile Project was
used to calculate take for several species. However, scientific surveys
and resulting data, such as population estimates, densities, and other
quantitative information, are lacking for some species. The ACOE also
gathered qualitative information from discussions with knowledgeable
local people that frequent the mouth of the Columbia River. Assumptions
regarding the size of expected groups of different species, and the
frequency of occurrence of those groups, were made by the ACOE on the
basis of the aforementioned information and are described for each
species below.
Since reliable densities are not available, the take numbers are
based on the assumed occurrence of a given stock during the activity.
The applicant used equation 1, below, to estimate take of killer whales
and Steller sea lions, equation 2 to estimate take of humpback whale,
harbor porpoise, California sea lions, and harbor seals, and neither
equation for gray whale or Northern elephant seals. NMFS concurs with
this method. The estimated take calculation for these/this species is
explained in the relevant section below.
(1) Estimated Take = number of individuals in a group x groups per day
x days of pile-related activity
(2) Estimated Take = total expected duration of the project (minutes) /
total duration of the Sand Island Test Pile Project x the total number
of animals of a given species observed during the Sand Island Test Pile
Project
Gray Whale
Historically gray whales have not frequented the mouth of the
Columbia River. No gray whales were observed during monitoring
activities of the Sand Island Test Pile Project (Hamer Environment L.P.
2020). In August of 2020, an ACOE biologist observed two gray whales
traveling upriver from the project site. Given this recent sighting and
the temporal overlap of the project and the most recent sighting, NMFS
authorized two takes of gray whales by Level B harassment.
The largest Level A harassment zone for gray whales extends 513 m
from the noise source (table 6). ACOE is planning to implement shutdown
zones for low-frequency cetaceans that exceed the Level A harassment
isopleth for all activities. Therefore, especially in combination with
the already low occurrence of gray whales in the area, implementation
of the shutdown zones is expected to eliminate the potential for take
by Level A harassment of gray whale. Therefore, no take by Level A
harassment is anticipated or authorized for humpback whales.
Humpback Whales
Humpback whales have occurred in the lower Columbia River near the
project area in recent years. Feeding groups have been using the mouth
of the Columbia River as a foraging ground, arriving as early as mid-
June, and have been observed as late as mid-November with a peak of
abundance coinciding with the peak abundance of forage fish in mid-
summer (The Columbian 2019). During pile driving activities of the Sand
Island Test Pile Project, seven animals were observed (Hamer
Environment L.P. 2020). The ACOE estimated take of humpback whales
using equation 2 above resulting in a take estimate of 16 takes by
Level B harassment (2277 (pile driving minutes for this activity)/1037
(pile driving minutes for Sand Island Test Pile Project) x 7 observed
animals). NMFS agrees with this approach and estimated take. As
described above, NMFS anticipates that 42 percent of takes will occur
to individuals of the Central America/Southern Mexico-CA/OR/WA stock
and 58 percent of takes will occur to individuals of the Mainland
Mexico-CA/OR/WA which will equate to seven and nine takes respectively.
The largest Level A harassment zone for humpback whales extends 513
m from the noise source (table 6). ACOE is planning to implement
shutdown zones for low-frequency cetaceans that exceed the Level A
harassment isopleth for all activities. Implementation of the shutdown
zones is expected to eliminate the potential for take by Level A
harassment of humpback whale. No take by Level A harassment is
anticipated or authorized for humpback whales.
Killer Whale
Use of the mouth of the Columbia River is rare for killer whales,
but in recent years pods of killer whales have been observed in and
around the mouth of the Columbia River. During the recent monitoring of
the Sand Island Test Pile Project, no killer whales were observed
(Hamer Environment L.P. 2020). Aerial seabird marine mammal surveys
observed 0 killer whales in January 2011, 0 in February 2012, and 10 in
September 2012 within an approximately 1,500 km2 range near the Mouth
of the Columbia River (Adams 2014). A pod of transient killer whales
was detected near the Astoria Bridge in May of 2018 (Frankowicz 2018)
and in 2022 (Tomlinson 2022). The ACOE estimated the average group
sizes from these past observations was seven. Based on the rare
occurrence of killer whales in the project area, ACOE expects that one
group of seven killer whales may occur during the 12 days of
construction in the Level B harassment zone. NMFS concurs and
authorized seven takes of killer whale by Level B harassment.
The largest Level A harassment zone for killer whales extends 17.8
m from the noise source (table 6). ACOE is planning to implement
shutdown zones for mid-frequency cetaceans that exceed the Level A
harassment isopleth for all activities. Implementation of the shutdown
zones is expected to eliminate the potential for take by Level A
harassment of killer whale. No take by Level A harassment is
anticipated or authorized for killer whales.
Harbor Porpoise
Harbor porpoises are regularly observed in the offshore waters near
the mouth of the Columbia River and are known to occur there year-
round. Porpoise abundance peaks when anchovy (Engraulis mordax)
abundance in the river and nearshore are highest, which is usually
between April and August (Litz et al. 2008). Harbor porpoise tend to
occur in groups of one to two individuals. During the recent monitoring
of the Sand Island Test Pile Project, eight harbor porpoise were
observed during construction activities (Hamer Environment L.P. 2020).
Using equation 2 above, ACOE expects that 18 takes by Level B
harassment will occur over the 12 days of pile driving (2277 (pile
driving minutes for this activity)/1037 (pile driving minutes for Sand
Island Test Pile Project) x 8 observed animals). NMFS agrees with this
approach and authorized 18 takes by Level B harassment of harbor
porpoise.
The largest Level A harassment zone for harbor porpoise extends 597
m from the noise source (table 6). ACOE is planning to implement
shutdown zones for high-frequency cetaceans that exceed the Level A
harassment isopleth for all activities, and it did not request take by
[[Page 79563]]
Level A harassment of harbor porpoise. For some activities (i.e.,
impact driving of 24-in piles), the shutdown zones extends farther than
Protected Species Observers (PSO) may be able to reliably detect harbor
porpoise. However, given the portion of the zone within which PSOs
could reliably detect a harbor porpoise, the infrequency of harbor
porpoise observations during the Sand Island Test Pile project
monitoring, and harbor porpoise sensitivity to noise, no take by Level
A harassment is anticipated or authorized for harbor porpoise.
Steller Sea Lion
Steller sea lion occurrence was estimated using Washington
Department of Fish and Wildlife haulout survey data from the South
Jetty at the mouth of the Columbia River from 2000 to 2014. During the
recent monitoring of the Sand Island Test Pile Project no Steller sea
lions were observed (Hamer Environment L.P. 2020). Given the close
proximity of the haulout, NMFS expects that Steller sea lions could
occur near the project site. Occurrence was estimated using the monthly
haulout numbers for the months when work will be occurring during the
project. In August, the average number of Steller sea lions hauled out
at the jetty was 72, and in October, the average number of sea lions at
the jetty was 77. In August, construction will occur over 7-days, and
in October, construction will occur over 5 days. Given the daily
occurrence rates and days of in-water construction, and using equation
1, the ACOE expects that 889 takes by Level B harassment will occur
(daily occurrence (72 or 77) x days of activity), and NMFS authorized
889 takes by Level B harassment of Steller sea lion.
The largest Level A harassment zone for Steller sea lions extends
19.5 m from the noise source (table 6). ACOE is planning to implement
shutdown zones for otariids that exceed the Level A harassment isopleth
for all activities. Implementation of the shutdown zones is expected to
eliminate the potential for take by Level A harassment of Steller sea
lion. No take by Level A harassment is anticipated or authorized for
Steller sea lion.
California Sea Lion
Similar to Steller sea lions, California sea lions use the South
Jetty at the mouth of the Columbia River and make frequent trips inside
the mouth of the river. Occurrence on the South Jetty peaks in summer
and use in the fall and winter is more concentrated. During recent
monitoring activities of the Sand Island Test Pile Project 59 animals
were observed (Hamer Environment L.P. 2020). Using equation 2 above,
ACOE expects that 144 takes by Level B harassment California sea lions
will occur (2277 (pile driving minutes for this activity)/1037 (pile
driving minutes for Sand Island Test Pile Project) x 59 observed
animals), and NMFS authorized 144 takes by Level B harassment of
California sea lion.
The largest Level A harassment zone for California sea lions
extends 19.5 m from the noise source (table 6). ACOE is planning to
implement shutdown zones for otariids that exceed the Level A
harassment isopleth for all activities. Implementation of the shutdown
zones is expected to eliminate the potential for take by Level A
harassment of California sea lion. No take by Level A harassment is
anticipated or authorized for California sea lion.
Harbor Seal
Harbor seals are the most abundant pinniped in Oregon and occur in
the project are year-round. Large numbers of harbor seals move through
the mouth of the Columbia River throughout the year and are expected to
be present in the project area. During recent monitoring of the Sand
Island Test Pile Project, a total of 309 harbor seals were observed
during construction activities (Hamer Environment L.P. 2020). Take
estimates were generated using equation 2 above and the Sand Island
Pile Test Project monitoring results. ACOE expects that 679 takes by
Level B harassment of harbor seals will occur during the project (2277
(pile driving minutes for this activity)/1037 (pile driving minutes for
Sand Island Test Pile Project) x 309 observed animals), and NMFS
authorized 679 takes by Level B harassment of harbor seal.
The Level A harassment zone for harbor seals during impact
installation is 268 m (table 6). ACOE will implement a shutdown zone of
150 m given the difficulty of observing harbor seals at greater
distances and practicability concerns regarding efficient work
production rates that will be associated with a larger shutdown zone
(see Mitigation section). During impact installation ACOE expects that
two harbor seals could be present in the Level A harassment zone.
Therefore, over the 3 days of impact pile driving, NMFS anticipates,
and authorized, six takes by Level A harassment (two takes per day * 3
days = six takes by Level B harassment).
Northern Elephant Seal
Northern elephant seals occur infrequently in the mouth of the
Columbia River. Recent sightings of elephant seals have occurred in the
fall and spring upriver from the project site. Although, no Northern
elephant seals were observed during the Sand Island Test Pile Project
(Hamer Environment L.P. 2020). ACOE expects that two animals may be
present in the Level B harassment zone during the 12-days of
construction, and NMFS authorized two takes by Level B harassment of
elephant seal.
The largest Level A harassment zone for Northern elephant seals
extends 268 m from the noise source (table 6). ACOE is planning to
implement shutdown zones for Northern elephant seal that exceed the
Level A harassment isopleth for all activities. Implementation of the
shutdown zones is expected to eliminate the potential for take by Level
A harassment of Northern elephant seal. No take by Level A harassment
is anticipated or authorized for Northern elephant seals.
Table 7--Authorized Take by Level A and Level B Harassment, by Species and Stock
----------------------------------------------------------------------------------------------------------------
Stock
Common name Stock abundance Level A Level B Total take Take as a
\a\ percentage
----------------------------------------------------------------------------------------------------------------
Gray Whale.................... Eastern N 26,960 0 2 2 <1
Pacific.
Humpback Whale................ Central America/ 1,494 0 7 7 <1
Southern Mexico-
CA/OR/WA.
Mainland Mexico- 3,477 0 9 9 <1
CA/OR/WA.
Killer Whale.................. West Coast 349 0 7 7 2
Transients.
Harbor Porpoise............... Northern OR/WA 22,074 0 18 18 <1
Coast.
Steller sea lion.............. Eastern......... 36,308 0 889 889 2.4
California Sea Lion........... United States... 257,074 0 144 144 <1
Harbor Seal................... OR/WA Coastal... UKN 6 679 685 N/A
[[Page 79564]]
Northern Elephant Seal........ CA Breeding..... 187,386 0 2 2 <1
----------------------------------------------------------------------------------------------------------------
\a\ Stock size is best estimate of population (Nbest) according to NMFS 2022 Final Stock Assessment Reports and
where apporiate the draft NMFS 2022 Final Stock Assessment Reports was used to estimate Nbest.
Mitigation
In order to issue an IHA under section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to the
activity, and other means of effecting the least practicable impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance. NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting the
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks, and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, NMFS
considers two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned), the likelihood of effective implementation (probability
implemented as planned), and;
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost, impact on
operations.
ACOE is required to implement the following mitigation measures:
Implementation of Shutdown Zones--For all pile driving/removal
activities, the ACOE will implement shutdowns within designated zones.
The purpose of a shutdown zone is generally to define an area within
which shutdown of activity will occur upon sighting of a marine mammal
(or in anticipation of an animal entering the defined area).
Implementation of shutdowns will be used to minimize the number and
severity of takes from vibratory and impact pile driving and removal
(table 8). For all pile driving/removal activities, a minimum 25-m
shutdown zone will be established for pinnipeds and 50-m shutdown zone
for cetaceans as outlined in the ACOE application for an IHA. For
harbor seals, ACOE will implement a shutdown zone of 25 m given its
concerns about potential frequent shutdowns that may occur with a
larger shutdown zone in consideration of high occurrence of harbor
seals in the project area. To minimize the potential of Level A
harassment of harbor seals, NMFS recommended a shutdown zone of 150 m
for harbor seals. ACOE concurred that this zone was practicable, and
therefore, NMFS required a shutdown zone of 150 m for harbor seals.
Shutdown zones for impact pile driving are based on the Level A
harassment zones and therefore vary by marine mammal hearing group
(table 8). The placement of PSOs during all pile driving activities
(described in detail in the Monitoring and Reporting section) will
ensure the full extent of shutdown zones are visible to PSOs.
Table 8--Shutdown Zones During Pile Installation and Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Shutdown zones (m)
-----------------------------------------------------------------------
Activity Pile size Northern
LF MF HF Harbor elephant Otariids
cetaceans cetaceans cetaceans seals seal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Installation........................ 24-in (pile markers)............ 50 50 50 25 25 25
Vibratory Installation and removal............ 24-in (MOF option 2)............ 50 50 50 25 25 25
Vibratory Installation and removal............ 24-in sheet pile (MOF option 1). 50 50 50 25 25 25
Impact Installation........................... 24-in (pile markers)............ 510 50 600 150 270 25
--------------------------------------------------------------------------------------------------------------------------------------------------------
Monitoring for Level A and Level B Harassment--The ACOE has
identified monitoring zones correlated with the Level B harassment
zones. Monitoring zones provide utility for observing by establishing
monitoring protocols for areas adjacent to the shutdown zones.
Monitoring zones enable observers to be aware of and communicate the
presence of marine mammals in the project area outside the shutdown
zone and thus prepare for a potential cessation of activity should the
animal enter the shutdown zone. PSOs will monitor the entire visible
area to maintain the best sense of where animals are moving relative to
the zone boundaries defined in table 8. Placement of PSOs on the
shorelines around Sand Island will allow PSOs to observe marine mammals
near the project area. While not required by this IHA, ACOE states that
it may also place a PSO on a skiff near the project area if safe
conditions allow.
Soft Start--Soft-start procedures are used to provide additional
protection to marine mammals by providing warning and/or giving marine
mammals a chance to leave the area prior to the hammer operating at
full capacity. For impact pile driving, contractors will be required to
provide an initial set of three strikes at reduced energy, followed by
a 30-second waiting period, then two subsequent reduced-energy strike
sets. Soft start will be implemented at the start of each day's impact
pile driving and at any time following cessation of impact pile driving
for a period of 30 minutes or longer. Soft start is not required during
vibratory pile driving and removal activities.
Pre-Activity Monitoring--Prior to the start of daily in-water
construction activity, or whenever a break in pile driving/removal of
30 minutes or longer occurs, PSOs will observe the shutdown and
monitoring zones for a period of 30
[[Page 79565]]
minutes. The shutdown zone will be considered cleared when a marine
mammal has not been observed within the zone for that 30-minute period.
If a marine mammal is observed within the shutdown zone, a soft-start
cannot proceed until the animal has left the zone or has not been
observed for 15 minutes. If the monitoring zone has been observed for
30 minutes and marine mammals are not present within the zone, soft-
start procedures can commence and work can continue. Pre-start
clearance monitoring must be conducted during periods of visibility
sufficient for the lead PSO to determine that the shutdown zones,
indicated in table 9, are clear of marine mammals. When a marine mammal
for which take by Level B harassment is authorized is present in the
Level B harassment zone, activities may begin. If work ceases for more
than 30 minutes, the pre-activity monitoring of both the monitoring
zone and shutdown zone will commence.
Based on our evaluation of the applicant's measures, NMFS has
determined that the mitigation measures provide the means of effecting
the least practicable impact on the affected species or stocks and
their habitat, paying particular attention to rookeries, mating
grounds, and areas of similar significance.
Monitoring and Reporting
In order to issue an IHA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present while
conducting the activities. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
<bullet> Occurrence of marine mammal species or stocks in the area
in which 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
Monitoring shall be conducted by NMFS-approved observers in
accordance with section 5 of the IHA. Trained observers shall be placed
from the best vantage point(s) practicable to monitor for marine
mammals and implement shutdown or delay procedures when applicable
through communication with the equipment operator. Observer training
must be provided prior to project start, and shall include instruction
on species identification (sufficient to distinguish the species in the
project area), description and categorization of observed behaviors and
interpretation of behaviors that may be construed as being reactions to
the specified activity, proper completion of data forms, and other
basic components of biological monitoring, including tracking of
observed animals or groups of animals such that repeat sound exposures
may be attributed to individuals (to the extent possible).
Monitoring will be conducted 30 minutes before, during, and 30
minutes after pile driving/removal activities. In addition, observers
shall record all incidents of marine mammal occurrence, regardless of
distance from activity, and shall document any behavioral reactions in
concert with distance from piles being driven or removed. Pile driving/
removal activities include the time to install or remove a single pile
or series of piles, as long as the time elapsed between uses of the
pile driving equipment is no more than 30 minutes.
A minimum of two PSO will be on duty during all in-water
construction activities. Locations from which PSOs will be able to
monitor for marine mammals are readily available from the shore of Sand
Island. PSOs will monitor for marine mammals entering the harassment
zones.
PSOs will scan the waters using binoculars or spotting scopes and
will use a handheld range-finder device to verify the distance to each
sighting from the project site. PSOs will be placed at the best vantage
point(s) practicable to monitor for marine mammals and implement
shutdown/delay procedures when applicable by calling for the shutdown
to the hammer operator via a radio.
The ACOE will adhere to the following observer qualifications:
(i) PSOs must be independent of the activity contractor (for
example, employed by a subcontractor) and have no other assigned tasks
during monitoring periods;
(ii) At least one PSO must have prior experience performing the
duties of a PSO during construction activity pursuant to a NMFS-issued
incidental take authorization;
(iii) 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;
(iv) 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
(v) PSOs must be approved by NMFS prior to beginning any activity
subject to this IHA.
Additional recommended observer qualifications include:
<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 and times when in-water construction
[[Page 79566]]
activities were suspended to avoid potential incidental injury from
construction sound of marine mammals observed within a defined shutdown
zone; 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.
Reporting
A draft marine mammal monitoring report will be submitted to NMFS
within 90 days after the completion of pile driving and removal
activities. It will include an overall description of work completed, a
narrative regarding marine mammal sightings, and associated PSO data
sheets. Specifically, the report must include:
<bullet> Dates and times (begin and end) of all marine mammal
monitoring.
<bullet> Construction activities occurring during each daily
observation period, including the number and type of piles driven or
removed and by what method (i.e., impact driving) and for each pile or
total number of strikes for each pile (impact driving).
<bullet> PSO locations during marine mammal monitoring.
<bullet> Environmental conditions during monitoring periods (at
beginning and end of PSO shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance.
<bullet> Upon observation of a marine mammal, the following
information: Name of PSO who sighted the animal(s) and PSO location and
activity at time of sighting; time of sighting; identification of the
animal(s) (e.g., genus/species, lowest possible taxonomic level, or
unidentified), PSO confidence in identification, and the composition of
the group if there is a mix of species; distance and bearing of each
marine mammal observed relative to the pile being driven for each
sighting (if pile driving was occurring at time of sighting); estimated
number of animals (min/max/best estimate); estimated number of animals
by cohort (adults, juveniles, neonates, group composition, etc.);
animal's closest point of approach and estimated time spent within the
harassment zone; description of any marine mammal behavioral
observations (e.g., observed behaviors such as feeding or traveling),
including an assessment of behavioral responses thought to have
resulted from the activity (e.g., no response or changes in behavioral
state such as ceasing feeding, changing direction, flushing, or
breaching).
<bullet> Number of marine mammals detected within the harassment
zones, by species.
<bullet> Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensued, and resulting changes in behavior of the
animal(s), if any.
If no comments are received from NMFS within 30 days, the draft
final report will constitute the final report. If comments are
received, a final report addressing NMFS comments must be submitted
within 30 days after receipt of comments.
Reporting Injured or Dead Marine Mammals
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, the Holder must report the
incident to the Office of Protected Resources (OPR), NMFS and to the
West Coast regional stranding network as soon as feasible. If the death
or injury was clearly caused by the specified activity, the Holder must
immediately cease the activities until NMFS OPR is able to review the
circumstances of the incident and determine what, if any, additional
measures are appropriate to ensure compliance with the terms of this
IHA. The Holder must not resume their activities until notified by
NMFS. The report must include the following information:
<bullet> Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
<bullet> Species identification (if known) or description of the
animal(s) involved;
<bullet> Condition of the animal(s) (including carcass condition if
the animal is dead);
<bullet> Observed behaviors of the animal(s), if alive;
<bullet> If available, photographs or video footage of the
animal(s); and
<bullet> General circumstances under which the animal was
discovered.
Negligible Impact Analysis and Determination
NMFS has defined negligible impact as an impact resulting from the
specified activity that cannot be reasonably expected to, and is not
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
``taken'' through harassment, NMFS considers other factors, such as the
likely nature of any impacts or responses (e.g., intensity, duration),
the context of any impacts or responses (e.g., critical reproductive
time or location, foraging impacts affecting energetics), as well as
effects on habitat, and the likely effectiveness of the mitigation. We
also assess the number, intensity, and context of estimated takes by
evaluating this information relative to population status. Consistent
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338,
September 29, 1989), the impacts from other past and ongoing
anthropogenic activities are incorporated into this analysis via their
impacts on the baseline (e.g., as reflected in the regulatory status of
the species, population size and growth rate where known, ongoing
sources of human-caused mortality, or ambient noise levels).
To avoid repetition, the majority of our analysis applies to all
the species listed in table 7, given that many of the anticipated
effects of this project on different marine mammal stocks are expected
to be relatively similar in nature. Where there are meaningful
differences between species or stocks, or groups of species, in
anticipated individual responses to activities, impact of expected take
on the population due to differences in population status, or impacts
on habitat, they are described independently in the analysis below.
Pile driving and removal activities associated with the project as
outlined previously, have the potential to disturb or displace marine
mammals. Specifically, the specified activities may result in take, in
the form of Level A harassment and Level B harassment from underwater
sounds generated from pile driving and removal. Potential takes could
occur if individuals of these species are present in zones ensonified
above the thresholds for Level A or Level B harassment identified above
when these activities are underway.
Take by Level A and Level B harassment will be due to potential
behavioral disturbance, TTS, and PTS. No serious injury or mortality is
anticipated or authorized given the nature of the activity and measures
designed to minimize the possibility of injury to marine mammals. Take
by Level A harassment is only anticipated for harbor seals. The
potential for
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harassment is minimized through the construction method (i.e., use of
direct pull removal or vibratory methods to the extent practical) and
the implementation of the mitigation measures (see Mitigation section).
Behavioral responses of marine mammals to pile driving and removal
at the project site, if any, are expected to be mild and temporary.
Marine mammals within the Level B harassment zone may not show any
visual cues they are disturbed by activities or could become alert,
avoid the area, leave the area, or display other mild responses that
are not observable such as changes in vocalization patterns. Given the
limited number of piles to be installed or extracted per day and that
pile driving and removal will occur across a maximum of 12 days within
the 12-month authorization period, any harassment will be temporary.
In addition to the expected effects resulting from Level B
harassment, we anticipate that harbor seals may sustain some limited
Level A harassment in the form of PTS. However, any PTS is expected to
be of a small degree (i.e., minor degradation of hearing capabilities
within regions of hearing that align most completely with the energy
produced by pile driving (below 2 kHz)) because animals would need to
be exposed to higher levels and/or longer duration than are expected to
occur here in order to incur any more than a small degree of PTS. If
hearing impairment occurs, it is most likely that the affected animal
would lose a few decibels in its hearing sensitivity, which in most
cases is not likely to meaningfully affect its ability to forage and
communicate with conspecifics, as it would be minor and not in the
region of greatest hearing sensitivity.
Additionally, and as noted previously, some subset of the
individuals that are behaviorally harassed could also simultaneously
incur some small degree of TTS for a short duration of time. Because of
the small degree anticipated, though, any PTS or TTS potentially
incurred here would not be expected to adversely impact individual
fitness, let alone annual rates of recruitment or survival.
The project also is not expected to have significant adverse
effects on affected marine mammals' habitat. The project activities
will not modify existing marine mammal habitat for a significant amount
of time. The activities may cause some fish or invertebrates to leave
the area of disturbance, thus temporarily impacting marine mammals'
foraging opportunities in a limited portion of the foraging range; but,
because of the short duration of the activities, the relatively small
area of the habitat that may be affected, and the availability of
nearby habitat of similar or higher value, the impacts to marine mammal
habitat are not expected to cause significant or long-term negative
consequences.
A large portion of the west coast, including the mouth of the
Columbia River, has been identified as a biologically important area
(BIA) for gray whale feeding (Calambokidis et al. 2024). As described
above, the presence of gray whales in the project area is rare, and the
area of overlap of the project with the feeding BIA affected is small
compared to the overall size of the BIA. The gray whale feeding BIA is
active from June through November while the project is scheduled to
occur between August and October, resulting in only three months of
overlap with the project and 3 months when the BIA is active but ACOE
will not be conducting work. Additionally, pile driving associated with
the project is expected to take only 12 days, further reducing the
temporal overlap with the BIA. Therefore, take of gray whales using
this feeding BIA, given both the small footprint of the activity
relative to the BIA, and the scope and nature of the anticipated
impacts of pile driving exposure, is not anticipated to impact the
reproduction or survival of any individuals.
In summary and as described above, the following factors primarily
support our determination that the impacts resulting from this activity
are not expected to adversely affect any of the species or stocks
through effects on annual rates of recruitment or survival:
<bullet> No serious injury or mortality is anticipated or
authorized;
<bullet> Any take by Level A harassment (harbor seals, only) is
anticipated to result in slight PTS within the lower frequencies
associated with pile driving;
<bullet> The anticipated incidents of Level B harassment will
consist of, at worst, temporary modifications in behavior that would
not result in fitness impacts to individuals;
<bullet> The area impacted by the specified activity is very small
relative to the overall habitat ranges of all stocks, and does not
overlap ESA-designated critical habitat. While impacts will occur
within an area that is important for gray whale feeding, because of the
small footprint of the activity relative to the feeding area, the
limited temporal overlap of the activity and the feeding period, and
the scope and nature of the anticipated impacts of pile driving
exposure, we do not expect impacts to the reproduction or survival of
any individuals; and
<bullet> ACOE will implement mitigation measures, such as soft-
starts for impact pile driving and shut downs, to minimize the numbers
of marine mammals exposed to injurious levels of sound, and to ensure
that take by Level A harassment, is at most, a small degree of PTS.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the monitoring and mitigation
measures, NMFS finds that the total marine mammal take from the
activity will have a negligible impact on all affected marine mammal
species or stocks.
Small Numbers
As noted previously, only take of small numbers of marine mammals
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is fewer than one-third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
Table 7 demonstrates the number of animals that NMFS anticipates
could be taken by Level A and Level B harassment for the work. Our
analysis shows that at most 2.4 percent of each affected stock could be
taken by harassment. The numbers of animals to be taken for these
stocks will be considered small relative to the relevant stock's
abundances, even if each estimated taking occurred to a new individual,
which is an unlikely scenario.
Based on the analysis contained herein of the activity (including
the mitigation and monitoring measures) and the anticipated take of
marine mammals, NMFS finds that small numbers of marine mammals will be
taken relative to the population size of the affected species or
stocks.
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
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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, in this case with the West Coast
Regional Office.
Two DPSs of humpback whale (Central America/Southern Mexico-CA/OR/
WA and Mainland Mexico-CA/OR/WA) occur in the project area and are
listed as endangered and threatened, respectively, under the ESA. The
NMFS West Coast Regional OPR Division issued a Biological Opinion on
September 11, 2025 under section 7 of the ESA, on the issuance of an
IHA to the ACOE under section 101(a)(5)(D) of the MMPA by the NMFS
Permits and Conservation Division. The Biological Opinion concluded
that the action is not likely to jeopardize the continued existence of
Central America/Southern Mexico-CA/OR/WA and Mainland Mexico-CA/OR/WA
humpback whales and is not likely to destroy or adversely modify their
critical habitat.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must evaluate our proposed action the issuance of an IHA and
alternatives with respect to potential impacts on the human
environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or
mortality) of the Companion Manual for NAO 216-6A, which do not
individually or cumulatively have the potential for significant impacts
on the quality of the human environment and for which we have not
identified any extraordinary circumstances that would preclude this
categorical exclusion. Accordingly, NMFS has determined that the
issuance of this IHA qualifies to be categorically excluded from
further NEPA review.
Authorization
NMFS has issued an IHA to the ACOE for the potential harassment of
small numbers of eight marine mammal species incidental to the pile
dike repair project in Baker Bay, Oregon, that includes the previously
explained mitigation, monitoring and reporting requirements.
Dated: September 25, 2024.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2024-22394 Filed 9-27-24; 8:45 am]
BILLING CODE 3510-22-P
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</html>Indexed from Federal Register on September 30, 2024.
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