Notice2025-11458
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Sand Island Pile Dike Repairs in the Columbia River
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
June 23, 2025
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from the U.S. Army Corps of Engineers (USACE) for authorization to take marine mammals incidental to the Sand Island Pile Dike Repairs Project in the Mouth of the Columbia River (MCR). 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 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 90 Issue 118 (Monday, June 23, 2025)</title>
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[Federal Register Volume 90, Number 118 (Monday, June 23, 2025)]
[Notices]
[Pages 26541-26554]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-11458]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RTID 0648-XE963
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Sand Island Pile Dike Repairs in
the Columbia River
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
[[Page 26542]]
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization; request
for comments on proposed authorization and possible renewal.
-----------------------------------------------------------------------
SUMMARY: NMFS has received a request from the U.S. Army Corps of
Engineers (USACE) for authorization to take marine mammals incidental
to the Sand Island Pile Dike Repairs Project in the Mouth of the
Columbia River (MCR). 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 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 July 23,
2025.
ADDRESSES: Comments should be addressed to 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#2c65787c025c4d59404542496c42434d4d024b435a"><span class="__cf_email__" data-cfemail="fbb2afabd58b9a8e9792959ebb95949a9ad59c948d">[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 below.
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/permit/incidental-take-authorizations-under-marine-mammal-protection-act">https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</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: Robert Pauline, 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 (collectively referred to as
``mitigation''); and requirements pertaining to the monitoring and
reporting of the takings. The definitions of all applicable MMPA
statutory terms used above are included in the relevant sections below
and can be found in section 3 of the MMPA (16 U.S.C. 1362) and NMFS
regulations at 50 CFR 216.103.
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.
Summary of Request
On February 26, 2025, NMFS received a request from the USACE for an
IHA to take marine mammals incidental to the multi-year Sand Island
Pile Dike Repairs project in the MCR. The USACE submitted the first
revised version on May 2, 2025, followed by another revision on April
1, 2025. A final version was submitted on May 2, 2025. The application
was deemed adequate and complete on June 3, 2025. The USACE's request
is for take of eight species of marine mammals by Level B harassment
and take by Level A harassment for a subset of 4 of these species.
Neither the USACE nor NMFS expect serious injury or mortality to result
from these activities and, therefore, an IHA is appropriate.
This IHA request is part of the multi-year Sand Island Pile Dike
Repairs project. NMFS previously issued two consecutive IHAs to the
USACE for this project on August 22, 2022 (87 FR 51346) with effective
dates of August 1, 2023 through July 31, 2024 (year 1) and August 1,
2024 through July 31, 2025 (year 2). NMFS also issued a modified IHA to
replace the second of the two initial IHAs (89 FR 82986; October 10,
2024). The modified IHA increased authorized take of humpback whale and
killer whale due to increased sightings of these species near the
project area. The USACE complied with all the requirements (e.g.,
mitigation, monitoring, and reporting) of the previous IHAs, and
information regarding their monitoring results may be found in the
Estimated Take of Marine Mammals section. This proposed IHA would cover
the third year of the Sand Island Pile Dike Repairs project.
Description of Proposed Activity
Overview
The 2025-2026 proposed IHA would cover the same construction
activities associated with the Sand Island Pile Dike Repairs project as
those described for the consecutive year 1 and year 2 IHAs. All
remaining work will be described below. NMFS refers the reader to the
documents related to the previously issued consecutive IHAs for more
detailed description of the project activities (https://
www.fisheries.noaa.gov/action/incidental-take-authorization-army-corps-
engineers-sand-island-pile-dikes-repairs-
[[Page 26543]]
columbia). These previous documents include the Federal Register notice
of the issuance of consecutive 2023-2024 and 2024-2025 IHAs (87 FR
51346; August 22, 2022); Federal Register notice of issuance of
modified 2024-2025 IHA (89 FR 82986; October 10, 2024); Federal
Register notice of the proposed IHAs (87 FR 39481; July 1, 2022) and
all associated references and documents. At the end of the year 2 IHA,
the USACE had 235 24-in steel piles left to be installed by impact and
vibratory driving as well as 8 existing 24-in steel barge piles that
will be extracted via vibratory removal. A total of 243 piles will be
driven/extracted over an estimated 34 work days. A brief description of
the work remaining for the proposed IHA is contained below. We also
refer the reader to USACE's previous and current applications and
monitoring reports which can be found at: <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-army-corps-engineers-sand-island-pile-dikes-repairs-columbia">https://www.fisheries.noaa.gov/action/incidental-take-authorization-army-corps-engineers-sand-island-pile-dikes-repairs-columbia</a>.
Dates and Duration
The Sand Island Pile Dike Repairs Project began in-water
construction work in August 2023. The first IHA was effective from
August 1, 2023 to July 31, 2024, and the year 2 IHA was effective from
August 1, 2024 through July 31, 2025. In-water work only occurred
between August and October each year. The proposed IHA would be valid
for the statutory maximum of one year from the date of effectiveness,
and will become effective upon written notification from the applicant
to NMFS, but not beginning later than one year from the date of
issuance or extending beyond two years from the date of issuance.
Specific Geographic Region
The Sand Island pile dike system consists of four pile dikes near
the MCR, between river mile (RM) 4 and RM 7. One of the pile dikes is
connected to West Sand Island (4.01), two of the pile dikes are
connected to East Sand Island (4.47, 5.15), and the fourth pile dike
(6.37) is in open water and runs parallel to the Chinook Federal
Navigation Channel on the upstream side. The three pile dikes connected
to West Sand Island and East Sand Island are located within Oregon,
while the fourth pile dike in open water spans both Oregon and
Washington. The Sand Island pile dikes are located in the downstream
terminus of the Columbia River tidal estuary, which is dominated by
freshwater inputs from the Columbia and Willamette rivers.
[GRAPHIC] [TIFF OMITTED] TN23JN25.010
Detailed Description of the Specified Activity
Major project elements proposed for the 2025 IHA include removing
existing timber piles, driving new steel pipe piles and placing rock
for multiple purposes including: scour protection at the base of the
new piles, enhanced enrockment segments, shore connections, and
revetment along the western portion of the shoreline at East Sand
Island. Existing timber piles may be removed by pulling, cutting or
snapping at the approximate level of the enrockment. Vibratory hammers
will not be used for timber pile removal. Pile removal is expected to
proceed incrementally as replacement repairs are made to ensure that
overall function is maintained during construction. At the completion
of work activities, the existing barge mooring piles will be removed
with a vibratory hammer within the appropriate work window.
The USACE has installed 418 of the 600 24-inch, steel pipe piles at
2 of the 4 pile dike locations during the last 2 construction seasons.
Another 24 24-inch, steel pipe piles will be installed as marker piles
along the enrockment (see table 1). It is anticipated that vibratory
hammers will be used to start the pile driving and will drive them 75
percent of the way, and impact hammers will be used to complete the
pile driving for the remaining 25 percent. There are a combined 243
piles needing installation (227 steel piles + 8 marker piles) and 8
existing steel piles that need to be extracted.
[[Page 26544]]
Table 1--Remaining 24-Inch Steel Pipe Piles To Complete Repairs
----------------------------------------------------------------------------------------------------------------
Steel piling Steel piles Marker pile Marker piles Barge pile
Pile dike (RM) installation remaining installation remaining extraction
----------------------------------------------------------------------------------------------------------------
4.01............................ 132 10 2 0 0
4.47............................ 132 77 4 4 0
5.15............................ 140 140 4 4 0
6.37............................ 196 0 14 0 0
-------------------------------------------------------------------------------
Total....................... 600 227 24 8 8
----------------------------------------------------------------------------------------------------------------
Estimated construction durations for major repair activities are
shown in table 2. The dates of work are estimates as the Contractor
will have the ability to perform the work as dictated by weather,
equipment and pile availability within the defined work window.
Table 2--Estimated Duration of Pile Driving Activities
----------------------------------------------------------------------------------------------------------------
Pile driving
Activity (RM) Estimated Piles Marker piles days at 8 Est. duration
start remaining remaining piles per day (days)
----------------------------------------------------------------------------------------------------------------
Pile Driving Activity Remaining
----------------------------------------------------------------------------------------------------------------
New pile installation at 4.01... 8/1/2025 10 0 2 8
New Pile Installation 4.47...... 8/9/2025 77 4 11 14
New Pile Installation 5.15...... 9/19/2025 140 4 18 32
Remove Barge Piles.............. 10/26/2025 8 0 3 3
----------------------------------------------------------------------------------------------------------------
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
A description of the marine mammals in the area of the activities
likely to be taken is found in the documents associated with the
previous consecutive IHAs. These remain applicable to the proposed
2025-2026 IHA. Note that NMFS has reviewed the Stock Assessment Reports
(SAR) and has revised table 3 with the most recent data available,
including from the draft 2024 SARs, which differs for some species
compared to the data in the table what was produced as part of the
analysis of the year 1 and year 2 IHAs.
Table 3 lists all species or stocks for which take is expected and
proposed to be authorized for this activity and summarizes information
related to the population or stock, including regulatory status under
the MMPA and Endangered Species Act (ESA) and potential biological
removal (PBR), where known. PBR is defined by the MMPA as the maximum
number of animals, not including natural mortalities, that may be
removed from a marine mammal stock while allowing that stock to reach
or maintain its optimum sustainable population (as described in NMFS'
SARs). While no serious injury or mortality is anticipated or proposed
to be authorized here, PBR and annual serious injury and mortality (M/
SI) 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. Alaska and Pacific SARs. All values presented in table 3 are
the most recent available at the time of publication (including from
the draft 2024 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 3--Marine Mammal Species With Estimated Take From the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/ MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
Gray whale...................... Eschrichtius robustus.. Eastern North Pacific.. -, -, N 26,960 (0.05, 25849, 801 131
2016).
Family Balaenopteridae (rorquals):
Humpback whale.................. Megaptera novaeangliae. Central America/ E, D, Y 1,496 (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).
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 26545]]
Superfamily 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 Oregon/ -, -, N 22,074 (0.391, 16,068, 161 >=3.2
Washington Coast. 2022).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
sea lions):
California sea lion............. Zalophus californianus. U.S. Stock............. -, -, N 257,606 (N/A, 233,515, 14,011 >321
2014).
Steller sea lion................ Eumetopias jubatus..... Eastern U.S............ -, -, N 36,308 (N/A, 36,308, 2,178 93.2
2022).
Family Phocidae (earless seals):
Harbor seal..................... Phoca vitulina Oregon and Washington -, -, N 22,549 (UNK, 19,561, UND 10.6
richardii. Coast. 2022) \4\.
Northern elephant seal.......... Mirounga angustirostris CA Breeding............ -, -, N 187,386 (N/A, 85,369, 5,122 13.7
2013).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region</a>. Draft 2024 SAR available at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-
assessment-reports#:~:text=Draft%202024%20Marine%20Mammal%20Stock%20Assessment%20Reports,-
Alaska%20Marine%20Mammal&text=NOAA%20Fisheries%20prepares%20marine%20mammal,the%20Marine%20Mammal%20Protection%20Act. CV is coefficient of variation;
Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
\4\ This is unlikely an underestimate of total abundance since it only includes data for the Washington portion of the Oregon-Washington Coastal Stock
(Pearson et al., 2024).
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.). Generalized hearing ranges were
chosen based on the ~65 decibel (dB) threshold from composite
audiograms, previous analyses in NMFS (2018), and/or data from Southall
et al. (2007) and Southall et al. (2019). We note that the names of two
hearing groups and the generalized hearing ranges of all marine mammal
hearing groups have been recently updated (NMFS 2024) as reflected in
table 4.
Table 4--Marine Mammal Hearing Groups
[NMFS, 2024]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 36 kHz.
whales).
High-frequency (HF) cetaceans 150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
whales, bottlenose whales).
Very High-frequency (VHF) cetaceans 200 Hz to 165 kHz.
(true porpoises, Kogia, river
dolphins, Cephalorhynchid,
Lagenorhynchus cruciger & L.
australis).
Phocid pinnipeds (PW) (underwater) 40 Hz to 90 kHz.
(true seals).
Otariid pinnipeds (OW) (underwater) 60 Hz to 68 kHz.
(sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges may not be as broad. Generalized hearing range
chosen based on ~65 dB threshold from composite audiogram, previous
analysis in NMFS 2018, and/or data from Southall et al. 2007; Southall
et al. 2019. Additionally, animals are able to detect very loud sounds
above and below that ``generalized'' hearing range.
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2024) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
A description of the potential effects of the specified activities
on marine mammals and their habitat may be found in the documents
supporting the previous consecutive IHAs, which remains applicable to
the proposed
[[Page 26546]]
2025-2026 IHA. These previous documents include the Federal Register
notice of the issuance of consecutive 2023-2024 and 2024-2025 IHAs (87
FR 51346; August 22, 2022); Federal Register notice of issuance of
modified 2024-20245 IHA (89 FR 82986; October 10, 2024); Federal
Register notice of the proposed IHAs (87 FR 39481; July 1, 2022).
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
proposed for authorization 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 would primarily be by Level B harassment, as use
of the acoustic source/s (i.e., impact driving, vibratory driving) has
the potential to result in disruption of behavioral patterns for
individual marine mammals. There is also some potential for auditory
injury (AUD INJ) (Level A harassment) to result, primarily for very
high frequency species, phocids and otariids. AUD INJ is unlikely to
occur for low-frequency species and high-frequency species. The
proposed 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 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 criteria above which NMFS believes the best
available science indicates marine mammals will likely be behaviorally
harassed or incur some degree of AUD INJ; (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 Criteria
NMFS recommends the use of acoustic criteria 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 AUD INJ of some degree (equated to
Level A harassment). We note that the criteria for AUD INJ, as well as
the names of two hearing groups, have been recently updated (NMFS 2024)
as reflected below in the Level A harassment section.
Level B Harassment--Though significantly driven by received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source or exposure context (e.g., frequency, predictability, duty
cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., bathymetry, other noises in the area,
predators in the area), and the receiving animals (hearing, motivation,
experience, demography, life stage, depth) and can be difficult to
predict (e.g., Southall et al., 2007, 2021, Ellison et al., 2012).
Based on what the available science indicates and the practical need to
use a threshold based on a metric that is both predictable and
measurable for most activities, NMFS typically uses a generalized
acoustic threshold based on received level to estimate the onset of
behavioral harassment. NMFS generally predicts that marine mammals are
likely to be behaviorally harassed in a manner considered to be Level B
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g.,
scientific sonar) sources.
Generally speaking, Level B harassment take estimates based on
these behavioral harassment thresholds are expected to include any
likely takes by temporary threshold shift (TTS) as, in most cases, the
likelihood of TTS occurs at distances from the source less than those
at which behavioral harassment is likely. TTS of a sufficient degree
can manifest as behavioral harassment, as reduced hearing sensitivity
and the potential reduced opportunities to detect important signals
(conspecific communication, predators, prey) may result in changes in
behavior patterns that would not otherwise occur.
The USACE's proposed activity includes the use of continuous (i.e.,
vibratory pile driving) and impulsive sources (i.e., vibratory pile
driving), and therefore the RMS SPL thresholds of 120 and 160 dB re 1
[mu]Pa are applicable.
Level A Harassment--NMFS' Updated Technical Guidance for Assessing
the Effects of Anthropogenic Sound on Marine Mammal Hearing (Version
3.0) (Updated Technical Guidance, 2024) identifies dual criteria to
assess AUD INJ (Level A harassment) to five different underwater 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 USACE's proposed activity includes includes the use of impulsive
(i.e., impact pile installation) and non-impulsive (i.e.,vibratory pile
installation) sources.
The 2024 Updated Technical Guidance criteria include both updated
thresholds and updated weighting functions for each hearing group. The
thresholds are provided in the table 5 below. The references, analysis,
and methodology used in the development of the criteria are described
in NMFS' 2024 Updated Technical Guidance, which may be accessed at:
<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance-other-acoustic-tools">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance-other-acoustic-tools</a>.
[[Page 26547]]
Table 5--Thresholds Identifying the Onset of Auditory Injury
----------------------------------------------------------------------------------------------------------------
AUD INJ onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 222 dB; Cell 2: LE,LF,24h: 197 dB.
LE,LF,24h: 183 dB.
High-Frequency (HF) Cetaceans.......... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,HF,24h: 201 dB.
LE,HF,24h: 193 dB.
Very High-Frequency (VHF) Cetaceans.... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,VHF,24h: 181 dB.
LE,VHF,24h: 159 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 223 dB; Cell 8: LE,PW,24h: 195 dB.
LE,PW,24h: 183 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 230 dB; Cell 10: LE,OW,24h: 199 dB.
LE,OW,24h: 185 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric criteria for impulsive sounds: Use whichever criteria results in the larger isopleth for
calculating AUD INJ onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure
level criteria associated with impulsive sounds, the PK SPL criteria are recommended for consideration for non-
impulsive sources.
Note: Peak sound pressure level (Lp,0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
exposure level (LE,p) has a reference value of 1 [micro]Pa\2\s. In this table, criteria are abbreviated to be
more reflective of International Organization for Standardization standards (ISO 2017, ISO 220). The subscript
``flat'' is being included to indicate peak sound pressure are flat weighted or unweighted within the
generalized hearing range of marine mammals underwater (i.e., 7 Hz to 165 kHz). The subscript associated with
cumulative sound exposure level criteria indicates the designated marine mammal auditory weighting function
(LF, HF, and VHF cetaceans, and PW and OW pinnipeds) and that the recommended accumulation period is 24 hours.
The weighted cumulative sound exposure level criteria 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 criteria 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 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 2024 Updated 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 and vibratory 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 AUD INJ. Inputs used in the optional User
Spreadsheet tool, and the resulting estimated isopleths, are reported
below.
Table 6--Estimated Unattenuated Underwater Sound Pressure Levels Associated With Vibratory and Impact Pile
Driving
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Pile type & activity Sound Pressure Level (SPL)
----------------------------------------------------------------------------------------------------------------
24-Inch Steel Pile installation w/ 203 dBPK............... 190 dB RMS............. 177 dBSEL.
impact hammer \1\.
24-Inch Steel Pile Installation or 194 dBPK............... 154 dB RMS............. Not Available.
Removal w/vibratory \2\.
----------------------------------------------------------------------------------------------------------------
\1\ Caltrans 2015.
\2\ Caltrans 2020.
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 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 initial measurement.
Absent site-specific acoustical monitoring with differing measured
TL, a practical spreading value of 15 is used as the TL coefficient in
the above formula and is used to determine the distances to the Level A
harassment and Level B harassment thresholds. 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 2024
Updated 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 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 auditory injury. Inputs used in
the optional User Spreadsheet tool and resulting estimated isopleths
are reported below tables 7 and 8.
[[Page 26548]]
Table 7--User Spreadsheet Inputs
------------------------------------------------------------------------
24-inch pile/
24-in pile/impact vibratory
------------------------------------------------------------------------
User Spreadsheet Variables and Inputs
------------------------------------------------------------------------
Spreadsheet tab used............ E.1) Impact Pile A.1) Vibratory
Driving pile driving.
(Stationary
Source).
Sound Pressure Level (dB)....... 177 dB SEL/203 pK. 154 dB RMS.
---------------------------------------
Distance associated with sound 10
pressure level (meters).
---------------------------------------
Transmission loss constant...... 15
---------------------------------------
Number of piles per day......... 8
---------------------------------------
Strikes/pile.................... 225............... ..................
Duration to drive pile (minutes) .................. 18.
Duration of sound production in .................. 8,640.
a day (seconds).
Marine Mammal WFA (kHz)......... 2................. 2.5.
------------------------------------------------------------------------
Table 8--Calculated Level A and Level B Isopleths
[m]
--------------------------------------------------------------------------------------------------------------------------------------------------------
AUD INJ/level A Level B all
-------------------------------------------------------------------------------- groups
------------------
Noise generation type Phocid Otariid Isopleth
LF HF VHF pinniped pinniped distances
(meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-inch Steel Pile Impact Installation............... 587 75 908 521 195 1,000 (160 dB)
24-inch Steel Pile Vibratory Installation............ 6 2 3 7 2 1,848 (120 dB)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Marine Mammal Occurrence and Take Estimation
In this section we provide information about the occurrence of
marine mammals, which will inform the take calculations. We will also
describe how this information is synthesized to produce a quantitative
estimate of the take that is reasonably likely to occur and proposed
for authorization. With the exception of northern elephant seal, the
methodologies utilized for estimating take of authorized species
differs from what was contained in the initial proposed IHA (87 FR
39481; July 1, 2022), final IHA (87 FR 51346; August 22, 2022), and
modified final IHA (89 FR 82986; October 10, 2024) Federal Register
notices. Monitoring data from year 1 and year 2 of this project was
used to estimate take for this proposed IHA as it is considered the
best available scientific information. The project's location and
seasonality (August-October) remain unchanged while the duration of the
activity for the proposed activity (34 days) is similar to the number
of work days utilized in year 1 (33) and year 2 (44). Note that the
USACE did not request authorization of take of gray whale in the
previous IHAs and none was authorized.
Humpback Whale
Protected Species Observers (PSOs) did not spot any humpback whales
according to the year 1 (33 days of in-water work) Sand Island
monitoring report. The year 2 (44 days of in-water work) Sand Island
monitoring reports submitted by the USACE did record 7 potential Level
B harassment takes and an additional 15 sightings. Whales were sighted
on 14 percent of in-water workdays (6 out of 44 days) and the average
daily rate when whales were observed was four (3.66 rounded up). We
conservatively assume that all sightings, whether within Level B
harassment zones or not, represent animals expected to be present in
the action area which could therefore be subject to incidental take. In
order to address potential for increased occurrence of humpback whales,
as occurred from year 1 to year 2, we assume that humpback whales would
be present on approximately 25 percent of workdays (34) under the
proposed IHA. Therefore, whales would be present on 9 work days. Nine
days multiplied by a daily sightings rate of 4 animals would result in
36 takes.
Therefore, the USACE has requested and NMFS proposes to authorize
36 takes by Level B harassment. No take by Level A harassment is
anticipated or proposed for authorization. Any humpback whales entering
into the Level A harassment zone will result in shutdown of in-water
activities by the USACE. The proposed takes will be split between the
Central America/Southern Mexico-CA/OR/WA stock and the Mainland Mexico-
CA/OR/WA stock with respective percentages of 42 and 58 percent (Wade
et al. 2021).
Gray Whale
The previous IHAs did not authorize take of gray whale since they
were rarely observed in the MCR. No sightings were reported in the year
1 or year 2 monitoring reports. However, there have recently been
sightings of two individuals upriver of the work area (Tidwell, 2024).
Therefore, the USACE has requested authorization of four takes (two
groups of two) by Level B harassment to account for the possibility of
the species entering the work area. NMFS concurs and proposes to
authorize four takes of gray whale by Level B harassment. No take by
Level A harassment is anticipated and none is proposed for
authorization.
Killer Whale
It is rare that killer whales are observed in the MCR, although
limited numbers of West Coast Transient (WCT) killer whales have been
observed there
[[Page 26549]]
in recent years and could potentially be present during proposed work,
but larger groupings of more than 20 animals occasionally form (WDFW,
2016). Sightings in the MCR include 1 sighting of T125A (Jetsam) in a
pod of 8-12 total WCT killer whales in 2018 (Frankowicz K.) and pod
T137 composed of 4 WCT killer whales in 2022 (Tomlinson). PSOs did not
spot any killer whales according to the year 1 and year 2 Sand Island
monitoring reports submitted by the USACE.
Given that limited numbers of killer whales have been reported in
the past, the USACE requests authorization of 12 takes by Level B
harassment which is equivalent to the largest pod size observed in the
MCR. No Level A harassment take is being requested due to infrequent
sightings of the species and the ease of spotting such at a
considerable distance. Any in-water work would cease if killer whales
were to approach the estimated harassment isopleths. NMFS concurs with
the USACE's request to authorize 12 killer whale takes by Level B
harassment. No take by Level A harassment is anticipated and none is
proposed for authorization.
Harbor Porpoise
The year 1 monitoring report listed 2 harbor porpoise sightings
while the year 2 report contained a total of 17 sightings with 3 of
those recorded as potential takes by Level B harassment. The maximum
number of sightings on a single day was 7 on August 3, 2024. The 17
observations occurred over 7 different days during a total of 44 in-
water work days. Analysis of this information shows that sightings
occurred on 16 percent (15.9 rounded up) of in-water work days during
the year 2 IHA effective period. For the purposes of estimating take,
we assume that all sightings represent animals present and that may be
subject to incidental take. It was also assumed that the maximum number
of porpoises recorded on a single day (7) may occur on 5 total days
during the project, resulting in 35 total exposures. We assume that
some take by Level A harassment may occur due to larger estimated Level
A harassment zones and the difficulty of effectively observing harbor
porpoise. Based on the size of the Level A harassment area associated
with very-high frequency cetaceans, we assume that 20 percent of the
total estimated exposures could result in AUD INJ. Therefore, NMFS is
proposing to authorize 7 takes of harbor porpoise by Level A harassment
and 28 takes by Level B harassment.
Pinnipeds
The Level A harassment and B harassment estimated takes of
pinnipeds is based on the maximum daily sightings of harbor seals,
California sea lions, and Steller sea lions from the previous 2 years
of work. Sightings recorded in the monitoring reports include both
takes by harassment as well as sightings that did not result in take.
Such sightings could have occurred if an animal was observed beyond the
estimated harassment areas or during periods when the contractor was
not actively engaged in pile driving operations.
After reviewing the year 1 and year 2 monitoring reports, the USACE
determined the maximum daily sightings were 16 harbor seals (year 1),
20 California sea lions (year 2), and 9 Steller sea lions (year 1). The
maximum daily sightings for each species was multiplied by the number
of work days in 2025 (34). The estimated total take is shown in table
10. Based on the size of the estimated Level A harassment zones, and
potential difficulty observing pinnipeds at the larger distances, Level
A harassment takes were estimated to be 10 percent of the total take
for each pinniped species.
Table 10--Estimated Take of Pinniped Species by Level A and Level B Harassment
----------------------------------------------------------------------------------------------------------------
California sea Steller sea
Species Harbor seal HS lion lion
----------------------------------------------------------------------------------------------------------------
Max Daily Sightings Year 1 (2023-2024).......................... 16 13 9
Max Daily Sightings Year 2 (2024-2025).......................... 13 20 8
Estimated total take (Max daily * 34 days)...................... 544 680 306
Level A harassment (10 percent of total take)................... 54 68 31
Level B harassment.............................................. 490 612 275
----------------------------------------------------------------------------------------------------------------
While no northern elephant seals were observed during the previous
2 years of monitoring, the species has been observed near the mouth of
the Columbia River. Based on the rare sightings in and around the
Columbia River, the USACE estimates that no more than two northern
elephant seals per month during August, September, and ctober may enter
the project area and be taken by Level B harassment. It is unlikely
that northern elephant seals would be found within the Level A
harassment zone even during impact driving (521 m isopleth). If they
were seen approaching the Level A harassment zone, the USACE would be
able to detect them and implement the required shutdown measures.
Therefore, the USACE has requested and NMFS is proposing to authorize
six northern elephant seal takes by Level B harassment.
The results of this estimated take analysis can be found in table
11, where the number of takes for all species that NMFS proposes for
authorization are presented.
Table 11--Proposed Take by Stock, Harassment Type, and as a Percentage of Stock Abundance
--------------------------------------------------------------------------------------------------------------------------------------------------------
Authorized Authorized
Species take by Level take by Level Total proposed Stock Stock Percent of
A harassment B harassment take abundance stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale............................ 0 15 15 Central America/Southern 1,494 1.0
Mexico--California/Oregon/
Washington.
0 21 21 Mainland Mexico--CA/OR/WA... 3,477 0.60
Gray whale................................ 0 4 4 Eastern North Pacific....... 26,960 0.01
[[Page 26550]]
Killer whale.............................. 0 12 12 West Coast Transient........ 349 3.44
Harbor porpoise........................... 7 28 35 Northern Oregon/Washington 22,074 0.16
Coast.
California sea lion....................... 68 612 680 U.S......................... 257,606 0.26
Steller sea lion.......................... 31 275 306 Eastern..................... 36,308 0.84
Harbor seal............................... 54 490 544 Oregon/Washington Coast..... 22,549 2.41
Northern elephant seal.................... 0 6 6 California Breeding......... 187,363 <0.01
--------------------------------------------------------------------------------------------------------------------------------------------------------
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)).
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 proposed mitigation measures are similar to those stated in the
Federal Register notice of the issuance of consecutive 2023-2024 and
2024-2025 IHAs (87 FR 51346; August 22, 2022) and the Federal Register
notice of issuance of modified 2024-20245 IHA (89 FR 82986; October 10,
2024) and are described below.
Time Restrictions
The USACE has described in its description of the project that pile
driving would occur only during daylight hours (no sooner than 30
minutes after sunrise through no later than 30 minutes before sunset),
when visual monitoring of marine mammals can be conducted. In addition,
to minimize impacts to ESA-listed fish species, all in-water
construction would be limited to the months of August through October.
Shutdown Zones
The USACE must establish shutdown zones for all pile driving
activates. 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 animal (or in anticipation of an animal entering the defined
area). Shutdown zones vary based on the activity type and duration and
marine mammal hearing group. As proposed by USACE, a minimum shutdown
zone of 25 m would implemented for all in-water construction activities
to avoid physical interaction with marine mammals. Marine mammal
monitoring would be conducted during all pile driving activities to
ensure that shutdowns occur, as required. Proposed shutdown zones for
each activity type are shown in table 12. Pile driving would not
commence until all marine mammals are clear of their respective
shutdown zones.
The USACE would also establish shutdown zones for all marine
mammals for which take has not been authorized or for which incidental
take has been authorized but the authorized number of takes has been
met. These zones are equivalent to the Level B harassment zones for
each activity (see table 12).
Table 12--Shutdown and Level B Harassment Monitoring Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
Shutdown zones (m) Level B
-------------------------------------------------------------------------------- harassment
Pile type and method Phocid Otariid monitoring
LF Cetacean HF Cetacean VHF Cetacean Pinniped Pinniped zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Steel pipe Pile Impact Installation............... 600 75 300 50 195 1,000
24-in Steel pipe Pile Vibratory Installation............ 25 25 25 25 25 1,848
--------------------------------------------------------------------------------------------------------------------------------------------------------
Protected Species Observers
USACE must employ PSOs and establish monitoring locations as
described below. The USACE must monitor the project area to the maximum
extent possible based on the required number of PSOs, required
monitoring locations, and environmental conditions
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
[[Page 26551]]
rain), pile driving would be delayed until the PSO is confident marine
mammals within the shutdown zone could be detected.
Monitoring for Level A and Level B Harassment
PSOs would monitor the Level B harassment zones to the extent
practicable, and all of the Level A 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 areas outside the shutdown zones and thus prepare for a
potential cessation of activity should the animal enter the shutdown
zone.
Pre-Activity Monitoring
Prior to the start of daily in-water construction activity, or
whenever a break in pile driving 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 that 30-minute period.
If a marine mammal is observed within the shutdown zones, pile
driving activity would be delayed or halted. If pile driving is delayed
or halted due to the presence of a marine mammal, the activity would
not commence or resume until either the animal has voluntarily exited
and been visually confirmed beyond the shutdown zones or 15 minutes
have passed without re-detection of the animal.
Pile driving activity must be halted upon observation of either a
species for which incidental take is not authorized or a species for
which incidental take has been authorized but the authorized number of
takes has been met, entering or within the harassment zone (as shown in
table 2).
The USACE, construction supervisors and crews, PSOs, and relevant
USACE staff must avoid direct physical interaction with marine mammals
during construction activity. If a marine mammal comes within 10 meters
of such activity, operations must cease and vessels must reduce speed
to the minimum level required to maintain steerage and safe working
conditions, as necessary to avoid direct physical interaction.
When a marine mammal for which Level B harassment take is
authorized is present in the Level B harassment zone, activities would
begin and Level B harassment take would be recorded. 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
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 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.
Based on our evaluation of the applicant'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.
The proposed monitoring and reporting measures are similar to those
described in the Federal Register notice of the issuance of consecutive
2023-2024 and 2024-2025 IHAs (87 FR 51346; August 22, 2022) and the
Federal Register notice of issuance of modified 2024-20245 IHA (89 FR
82986; October 10, 2024) and are described below.
Visual Monitoring
Marine mammal monitoring during pile driving activities would be
conducted by PSOs meeting NMFS' standards and in a manner consistent
with the following:
<bullet> Independent PSOs (i.e., not construction personnel) who
have no other assigned tasks during monitoring periods would be used;
<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; and
<bullet> Where a team of three or more PSOs is required, a lead
observer or monitoring coordinator would be designated. The lead
observer would be required to have prior experience working as a marine
mammal observer during construction.
[[Page 26552]]
<bullet> PSOs must be approved by NMFS prior to beginning any
activity subject to this IHA.
PSOs would 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 USACE would have at least two PSOs stationed in the project
area to monitor during all pile driving activities. One PSO would be
positioned at the work site on the construction barge to observe Level
A harassment and shutdown zones. At least one PSO would monitor from a
boat to ensure full visual coverage of the Level B harassment zone(s)
and alert construction crews of marine mammals entering the Level B
harassment zone and/or approaching the Level A harassment zones.
Additional PSOs may be employed during periods of low or obstructed
visibility to ensure the entirety of the shutdown zones are monitored.
PSOs must record all observations of marine mammals, regardless of
distance from the pile being driven, as well as the additional data
indicated below.
Reporting
A draft marine mammal monitoring report would be submitted to NMFS
within 90 days after the completion of pile driving activities, or 60
days prior to a requested date of issuance of any future IHAs for the
project, or other projects at the same location, whichever comes first.
The marine mammal report would include an overall description of work
completed, a narrative regarding marine mammal sightings, and
associated PSO data sheets. Specifically, the report would include:
<bullet> Dates and times (begin and end) of all marine mammal
monitoring;
<bullet> Construction activities occurring during each daily
observation period, including: (a) How many and what type of piles were
driven or removed and the method (i.e., impact or vibratory); and (b)
the total duration of time for each pile (vibratory driving) number of
strikes for each pile (impact driving);
<bullet> PSO locations during marine mammal monitoring; and
<bullet> Environmental conditions during monitoring periods (at
beginning and end of PSO shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance.
For each observation of a marine mammal, the following would be
reported:
<bullet> Name of PSO who sighted the animal(s) and PSO location and
activity at time of sighting;
<bullet> Time of sighting;
<bullet> Identification of the animal(s) (e.g., genus/species,
lowest possible taxonomic level, or unidentified), PSO confidence in
identification, and the composition of the group if there is a mix of
species;
<bullet> Distance and location of each observed marine mammal
relative to the pile being driven or hole being drilled for each
sighting;
<bullet> Estimated number of animals (min/max/best estimate);
<bullet> Estimated number of animals by cohort (adults, juveniles,
neonates, group composition, etc.);
<bullet> Description of any marine mammal behavioral observations
(e.g., observed behaviors such as feeding or traveling), including an
assessment of behavioral responses thought to have resulted from the
activity (e.g., no response or changes in behavioral state such as
ceasing feeding, changing direction, flushing, or breaching);
<bullet> Number of marine mammals detected within the harassment
zones, by species; and
<bullet> Detailed information about implementation of any
mitigation (e.g., shutdowns and delays), a description of specified
actions that ensued, and resulting changes in behavior of the
animal(s), if any.
If no comments are received from NMFS within 30 days, the draft
reports would constitute the final reports. If comments are received, a
final report addressing NMFS' comments would be required to be
submitted within 30 days after receipt of comments. All PSO datasheets
and/or raw sighting data would be submitted with the draft marine
mammal report.
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, the USACE would report the
incident to the Office of Protected Resources (OPR)
(<a href="/cdn-cgi/l/email-protection#2575770b6c71750b684a4b4c514a574c4b427740554a575156654b4a44440b424a53"><span class="__cf_email__" data-cfemail="663634482f3236482b09080f1209140f080134031609141215260809070748010910">[email protected]</span></a>), NMFS and to the West Coast Region
(WCR) regional stranding coordinator as soon as feasible. If the death
or injury was clearly caused by the specified activity, the USACE would
immediately cease the specified activities until NMFS is able to review
the circumstances of the incident and determine what, if any,
additional measures are appropriate to ensure compliance with the terms
of the IHAs. The USACE would not resume their activities until notified
by NMFS.
The report would include the following information:
1. Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
2. Species identification (if known) or description of the
animal(s) involved;
3. Condition of the animal(s) (including carcass condition if the
animal is dead);
4. Observed behaviors of the animal(s), if alive;
5. If available, photographs or video footage of the animal(s); and
6. 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
[[Page 26553]]
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 11, given that the anticipated effects of
this activity on these different marine mammal stocks are expected to
be similar. There is little information about the nature or severity of
the impacts, or the size, status, or structure of any of these species
or stocks that would lead to a different analysis for this activity.
Pile driving activities associated with the Sand Island Pile Dike
Repairs Project have the potential to disturb or displace marine
mammals. Specifically, the project activities may result in take, in
the form of Level A and Level B harassment, from underwater sounds
generated from pile driving. Potential takes could occur if individuals
are present in the ensonified zone when these activities are underway.
The takes by Level B harassment would be due to potential
behavioral disturbance and TTS. Takes by Level A harassment would be
due to auditory injury. No mortality or serious injury is anticipated
given the nature of the activity, even in the absence of the required
mitigation. The potential for harassment is minimized through the
implementation of the proposed mitigation measures (see Proposed
Mitigation section).
Take by Level A harassment is proposed for authorization to account
for the potential that an animal could enter and remain within the area
between a Level A harassment zone and the shutdown zone for a duration
long enough to be taken by Level A harassment. Any take by Level A
harassment is expected to arise from, at most, a small degree of
auditory injury 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 auditory injury. Additionally,
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 auditory
injury or TTS potentially incurred here would not be expected to
adversely impact individual fitness, let alone annual rates of
recruitment or survival.
Behavioral responses of marine mammals to pile driving at the
project site, if any, are expected to be mild and temporary. Marine
mammals within the Level B harassment zone may not show any visual cues
they are disturbed by activities or could become alert, avoid the area,
leave the area, or display other mild responses that are not observable
such as changes in vocalization patterns. Given that pile driving and
removal would occur across a maximum of 34 days over a 3-month period,
any harassment would be temporary.
Take would occur within a limited, confined area (Sand Islands in
the MCR) of the stocks' ranges. Given the availability of suitable
habitat nearby, any displacement of marine mammals from the project
areas is not expected to affect marine mammals' fitness, survival, and
reproduction due to the limited geographic area that would be affected
in comparison to the much larger habitat for marine mammals within the
lower Columbia River and immediately outside the river along the Oregon
and Washington coasts.
The intensity and duration of take by Level A harassment and Level
B harassment would be minimized through use of mitigation measures
described herein. Further, there are no areas of specific biological
importance (e.g., ESA critical habitat, other BIAs, or other areas) for
any other species are known to co-occur with the project area; and
Any impacts on marine mammal prey that would occur during the
USACE's proposed activity would have, at most, short-term effects on
foraging of individual marine mammals, and likely no effect on the
populations of marine mammals as a whole. Indirect effects on marine
mammal prey during the construction are expected to be minor, and these
effects are unlikely to cause substantial effects on marine mammals at
the individual level, with no expected effect on annual rates of
recruitment or survival.
In addition, it is unlikely that elevated noise in a small,
localized area of habitat would have any effect on the stocks' annual
rates of recruitment or survival. In combination, we believe that these
factors, as well as the available body of evidence from other similar
activities, demonstrate that the potential effects of the specified
activities will have only minor, short-term effects on individuals. The
specified activities are not expected to impact rates of recruitment or
survival, and would therefore not result in population-level impacts.
Monitoring reports from Sand Island Pile Dikes location during Year
1 and Year 2 have documented little to no behavioral effect on
individuals of the same species that could be impacted by the specified
activities, suggesting the degree/intensity of behavioral harassment
would be minimal.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
this activity are not expected to adversely affect any of the species
or stocks through effects on annual rates of recruitment or survival:
<bullet> No serious injury or mortality is anticipated or
authorized;
<bullet> The intensity of anticipated takes by Level B harassment
is relatively low for all stocks and would not be of a duration or
intensity expected to result in impacts on reproduction or survival;
<bullet> The ensonified areas are very small relative to the
overall habitat ranges of all species and stocks, and will not
adversely affect ESA-designated critical habitat for any species or any
areas of known biological importance;
<bullet> The lack of anticipated significant or long-term negative
effects to marine mammal habitat;
<bullet> The availability of nearby areas of similar habitat value
(e.g., foraging and haulout habitats) within and outside the MCR;
<bullet> Impacts on marine mammal feeding are not expected to
result in significant or long-term consequences for individuals, or to
accrue to adverse impacts on their populations;
<bullet> The USACE would implement mitigation measures, such as
soft-starts for impact pile driving and shutdowns 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
auditory injury.
<bullet> Previous marine mammal monitoring reports for similar
activities at the same location have documented little to no behavioral
effect on individuals.
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.
[[Page 26554]]
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 (see 86 FR
5322; January 19, 2021). Additionally, other qualitative factors may be
considered in the analysis, such as the temporal or spatial scale of
the activities.
The instances of take NMFS has proposed to authorize is below one-
third of the estimate stock abundance for all species. The number of
animals proposed for authorization that could be taken from these
stocks would be considered small relative to the relevant stocks'
abundances even if each estimated taking occurred to a new individual.
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 ensures 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.
NMFS is proposing to authorize take of humpback whale Mainland
Mexico and Central America/Southern Mexico DPS, which are listed under
the ESA. The effects of this proposed Federal action were adequately
analyzed in NMFS' Biological Opinion and Magnuson-Stevens Fishery
Conservation and Management Act Essential Fish Habitat Response for the
Sand Island Pile Dike Repair Project, dated June 14, 2022 which
concluded that the take NMFS proposes to authorize through this IHA
would not jeopardize the continued existence of any endangered or
threatened species.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to the USACE for conducting construction activity at Sand
Island in the MCR, 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 Sand
Island Pile Dike repair 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, 1-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 1 year from expiration
of the initial IHA).
<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).
(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.
<bullet> 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: June 16, 2025.
Tanya Dobrzynski,
Acting Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2025-11458 Filed 6-20-25; 8:45 am]
BILLING CODE 3510-22-P
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