Notice2025-04995
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to U.S. Coast Guard Construction in Florence, Oregon
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
March 25, 2025
Effective
November 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 U.S. Coast Guard (USCG) to incidentally harass marine mammals during pile driving activities associated with Station Siuslaw River construction project in Florence, Oregon.
Full Text
<html>
<head>
<title>Federal Register, Volume 90 Issue 56 (Tuesday, March 25, 2025)</title>
</head>
<body><pre>
[Federal Register Volume 90, Number 56 (Tuesday, March 25, 2025)]
[Notices]
[Pages 13582-13592]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-04995]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XE693]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to U.S. Coast Guard Construction in
Florence, Oregon
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of an incidental harassment authorization.
-----------------------------------------------------------------------
SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued an Incidental Harassment Authorization (IHA) to
the U.S. Coast Guard (USCG) to incidentally harass marine mammals
during pile driving activities associated with Station Siuslaw River
construction project in Florence, Oregon.
DATES: The authorization is effective from November 1, 2025 through
October 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-us-coast-guards-station-siuslaw-river-construction-project">https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-coast-guards-station-siuslaw-river-construction-project</a>. In case of problems accessing these documents,
please call the contact listed below.
FOR FURTHER INFORMATION CONTACT: Jenna Harlacher, 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
[[Page 13583]]
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 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.
Summary of Request
On October 26, 2023, NMFS received a request from the USCG for an
IHA to take marine mammals incidental to pile driving activity
associated with the Station Siuslaw River construction project in
Florence, Oregon. Following NMFS' review of the application, we
received a revised version of the application on April 18, 2024. After
finalizing construction details, the USCG submitted revised versions on
July 16, 2024 and October 16, 2024, followed by a final revised version
on November 18, 2024, which was deemed adequate and complete on
December 5, 2024. USCG's request is for take of harbor seal, California
sea lion, Steller sea lion, and harbor porpoise by Level B harassment,
and for harbor seal and harbor porpoise, Level A harassment. Neither
USCG nor NMFS expect serious injury or mortality to result from this
activity and, therefore, an IHA is appropriate.
Description of Activity
Overview
The USCG requested an IHA to correct shoreline erosion and replace
the covered mooring and appurtenant structures at USCG Station Siuslaw
River in Florence, Oregon (figure 1). This two-phased project entails
both onshore and in-water construction activities including site
preparation, demolition, shoreline stabilization measures, pile removal
and installation, and overwater construction. Phase 1 includes onshore
infrastructure improvements, sitework and shoreline stabilization, and
phase 2 includes overwater and in-water construction including all pile
install and removal.
The only part of the project that may result in Level A and Level B
harassment of marine mammals, and further analyzed in this notice, are
the in-water construction activities associated with vibratory and
impact pile driving (phase 2). The USCG plans to remove 71 timber piles
via vibratory driving and to install 79 total piles via vibratory and
impact driving with an estimated 48 total days of pile removal and
install. USCG plans to install 16-inch (in) (40.6 centimeters (cm)) to
20-in (50.8 cm) steel pipe piles, and/or 14-in (35.6 cm) H-piles for
their new infrastructure. Pile driving will only occur within the
Oregon Department of Fish and Wildlife (ODFW) approved in-water work
window; however the IHA will have a 1-year period of effectiveness.
A detailed description of the planned construction project is
provided in the Federal Register notice for the proposed IHA (90 FR
7082, January 21, 2025). Since that time, no changes have been made to
the planned construction 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 USCG was published in
the Federal Register on January 21, 2025 (90 FR 7082). That notice
described, in detail, USCG's activities, the marine mammal species that
may be affected by the activities, and the anticipated effects on
marine mammals. In that notice, we requested public input on the
request for authorization described therein, our analyses, the proposed
authorization, and any other aspect of the notice of proposed IHA, and
requested that interested persons submit relevant information,
suggestions, and comments. This proposed notice was available for a 30-
day public comment period. During the 30-day public comment period,
NMFS 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>) and
more general information about these species (e.g., physical and
behavioral descriptions) may be found on NMFS' website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 1 lists all species or stocks for which take is expected and
authorized for this activity and summarizes information related to the
population or stock, including regulatory status under the MMPA and
Endangered Species Act (ESA) and potential biological removal (PBR),
where known. PBR is defined by the MMPA as the maximum number of
animals, not including natural mortalities, that may be removed from a
marine mammal stock while allowing that stock to reach or maintain its
optimum sustainable population (as described in NMFS' SARs). While no
serious injury or mortality is anticipated or authorized here, PBR and
annual serious injury and mortality (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. Pacific Marine Mammal 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>.
[[Page 13584]]
Table 1--Marine Mammal Species \1\ Likely To Occur Near the Project Area That May Be Taken by USCG's Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/ MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\2\ abundance survey) \3\ SI \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocoenidae (porpoises):
Harbor Porpoise................. Phocoena phocoena...... Central Oregon \5\..... -, -, N 7,492 (0.421, 5,332, 53 0
2022).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
sea lions):
CA Sea Lion..................... Zalophus californianus. U.S.................... -, -, N 257,606 (N/A, 233,515, 14,011 >321
2014).
Steller Sea Lion \6\............ Eumetopias jubatus..... Eastern................ -, -, N 36,308 (N/A, 36,308, 2,178 93.2
2022).
Family Phocidae (earless seals):
Harbor Seal..................... Phoca vitulina......... OR/WA Coastal.......... -, -, N UNK (UNK, UNK, 1999).. UND 10.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
(<a href="https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/">https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/</a>; Committee on Taxonomy (2022)).
\2\ 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.
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (commercial
fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated
with estimated mortality due to commercial fisheries is presented in some cases.
\5\New stock in 2023 SARs.
\6\Nest is best estimate of counts, which have not been corrected for animals at sea during abundance surveys. Estimates provided are for the United
States only.
All species that could potentially occur in the project areas are
included in section 3 of the IHA application on page 12. While killer
whales (Orcinus orca), humpback whales (Megaptera novaeangliae), and
gray whales (Eschrichtius robustus) have been sighted off the Oregon
coast, the USCG's project is located in the Siuslaw River where these
species do not occur. Therefore, the temporal and/or spatial occurrence
of these species is such that take is not expected to occur, and they
are not discussed further beyond the explanation provided here and in
the USCG's application. For more details on the species that are likely
to occur near the project area and may be taken by USCG's activities,
see sections 3 and 4 of USCG's IHA application, the SARs, and NMFS'
website.
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
below in table 2.
Table 2--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.
[[Page 13585]]
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
The effects of underwater noise from USCG's construction activities
have the potential to result in harassment of marine mammals in the
vicinity of the project area. The notice of proposed IHA (90 FR 7082,
January 21, 2025) included a discussion of the effects of anthropogenic
noise on marine mammals and the potential effects of underwater noise
from the USCG's pile driving activities on marine mammals and their
habitat. That information and analysis is referenced in the notice and
is not repeated here; please refer to the notice of the proposed IHA
(90 FR 7082, January 21, 2025).
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
authorized through the IHA, which will inform NMFS' consideration of
``small numbers,'' the negligible impact determinations, and impacts on
subsistence uses.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes will primarily be by Level B harassment, as use of
the acoustic sources (i.e., pile driving) has the potential to result
in disruption of behavioral patterns for individual marine mammals.
There is also some potential for auditory injury (Level A harassment)
to result, primarily for very high frequency species and phocids
because predicted auditory injury zones are larger than for high-
frequency species and otariids. Auditory injury is unlikely to occur
for high-frequency species and otariids. The mitigation and monitoring
measures are expected to minimize the severity of the taking to the
extent practicable. As described previously, no serious injury or
mortality is anticipated 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 criteria above which NMFS believes the best
available science indicates marine mammals will likely be behaviorally
harassed or incur some degree of auditory injury; (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 Criteria
NMFS recommends the use of acoustic criteria that identify the
received level of underwater sound above which exposed marine mammals
will be reasonably expected to be behaviorally harassed (equated to
Level B harassment) or to incur auditory injury of some degree (equated
to Level A harassment). We note that the criteria for auditory injury,
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 [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.
USCG's planned activity 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' 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 auditory injury (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). USCG's planned activity includes the use
of impulsive (impact pile driving) and non-impulsive (vibratory pile
driving) sources.
The 2024 Updated Technical Guidance criteria include both updated
thresholds and updated weighting functions for each hearing group. The
thresholds are provided in table 3 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 13586]]
Table 3--Thresholds Identifying the Onset of Auditory Injury
----------------------------------------------------------------------------------------------------------------
Auditory injury 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 auditory injury 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 [mu]Pa, and weighted cumulative sound
exposure level (LE,p) has a reference value of 1 [mu]Pa\2\s. In this Table, criteria are abbreviated to be
more reflective of International Organization for Standardization standards (ISO 2017; ISO 2020). 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 USCG opted to perform its own acoustic modeling for the Level A
and Level B harassment isopleths using dBSea, a software developed by
Marshall Day Acoustics for the modeling of underwater sound propagation
in a variety of environments. Use of this model allowed USCG to
incorporate site-specific information, therefore providing more
accurate results than other more generalized tools. dBSea was also used
in a previous construction project by the USCG (88 FR 77985, November
11, 2023). NMFS has reviewed USCG's modeling and determined that it is
acceptable for use here.
Marshall Day Acoustics built the model by importing bathymetry data
and placing noise sources in the environment. Each source can consist
of equipment chosen from either the standard or the user-defined
databases. Noise mitigation methods may also be included. The user has
control over the seabed and water properties including sound speed
profile, temperature, salinity, and current. To examine results in more
detail, the model allows users to plot noise levels in cross sections,
or extract a detailed spectrum at any point in the calculation area.
USCG calculated noise levels to the deepest depth within the project
area.
USCG derived representative acoustic modeling scenarios based on
descriptions of the expected construction activities through
consultations between the USCG project design and engineering teams.
The team modeled activities that are expected to result in take of
marine mammals (i.e., in-water pile driving and removal) at a location
with characteristics representative of the project site. The USCG
modeled the full range of potential water depths in the project area at
a single representative location. As described in the Detailed
Description of the Specified Activity section of the notice of the
proposed IHA (90 FR 7082, January 21, 2025), USCG may install a variety
of pile types and sizes, and the exact pile sizes have not yet been
determined. However, in an effort to avoid underestimating potential
impacts to marine mammals, USCG conducted its analysis using the
maximum possible pile size for each project use. Table 4 lists the
sound source levels for each activity that USCG incorporated into the
model. Table 5 shows the model-estimated Level A and Level B harassment
isopleths for the planned activities. Please refer to the Acoustic
Assessment included in USCG's IHA application for additional details on
the modeling principles and assumptions and a summary of construction
and operational scenarios included in the underwater acoustic modeling
analysis.
Table 4--Estimates of Underwater Sound Sources * Generated During Vibratory and Impact Pile Installation and Vibratory Pile Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pile driving method Pile type and size db RMS dB peak db SEL Reference
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact installation..................... Steel pipe pile 24-in..... 194 207 178 Caltrans 2020.
H-pile.................... 178 200 166 Caltrans 2020.
Vibratory installation.................. Steel pipe pile 24-in..... 165 .............. .............. Caltrans 2020.
Vibratory removal....................... Timber.................... 162 .............. .............. Caltrans 2020.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: dB peak = peak sound level; rms = root mean square; SEL = sound exposure level.
* All sound levels are referenced at 10 m.
[[Page 13587]]
Table 5--Level A and Level B Harassment Isopleths
----------------------------------------------------------------------------------------------------------------
Level A isopleth (m)
Size and type ------------------------------------------------ Level B
VHF Phocids Otariids isopleth (m)
----------------------------------------------------------------------------------------------------------------
Vibratory Installation and Removal
----------------------------------------------------------------------------------------------------------------
24-in steel pipe pile installation.............. 58 39 17 1,117
Timber removal.................................. 16 14 .............. 1,106
----------------------------------------------------------------------------------------------------------------
Impact Installation
----------------------------------------------------------------------------------------------------------------
24-in steel pipe pile........................... 335 256 95 717
H-pile.......................................... 96 35 18 110
----------------------------------------------------------------------------------------------------------------
Marine Mammal Occurrence and Take Calculation and 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 and describe how the information
provided is synthesized to produce a quantitative estimate of the take
that is reasonably likely to occur and authorized. The USCG uses marine
mammal species densities from the Pacific Navy Marine Species Density
Database to estimate take for marine mammals. This database
incorporates analyzed literature and research for marine mammal density
estimates per season for regions throughout the United States, and the
USCG based their take estimates on regionally available population
density estimates and site-specific knowledge. Although this database
provides densities for all species present in the action area, the
densities are based on offshore abundance and not directly relevant to
occurrence within in the Siuslaw River. Following careful review of the
analysis presented by the USCG in its application, including marine
mammal occurrence data, NMFS has determined that different information
inputs than those selected by the USCG, represent the best available
scientific information for marine mammal abundance in the action area.
These selections are discussed in greater detail below.
For all species, the numbers of individuals are based on average
group sizes from Bates et al. (2023) that described marine mammal
occurrences near Coos Bay, Oregon in 2014 and 2015. While Coos Bay is
south of the action area, this area is more representative of the
action area within the Siuslaw River than the offshore data in the
application. We derived potential take estimates from the average group
sizes recorded over the specified period in Bates et al. (2023) and
used the occurrences of these sightings during the surveys, along with
sightings in OBIS-SEAMAP around the action area, to estimate our
sighing rates in the project vicinity (table 6).
Table 6--Species Rate in the Action Area
------------------------------------------------------------------------
Sighting rate for
Species Average group size action area
------------------------------------------------------------------------
California sea lion......... 1.4 Group every other
day.
Steller sea lion............ 1.8 Group every other
day.
Harbor seal................. 1 2 groups/day.
Harbor porpoise............. 1.3 Group every other
day.
------------------------------------------------------------------------
To calculate the total estimated takes by Level B harassment, we
multiplied the estimated days of activity by the associated average
group size and sighting rate for each species (table 6). There is also
some potential for take by Level A harassment of harbor seal and harbor
porpoise during impact pile driving due to the largest zones of each
species being greater than the shutdown zones and because of the
cryptic nature and assumed lower detectability of these species.
Based on the relative proportion of the area expected to be
ensonified above the Level A harassment threshold for phocids from
impact pile driving (approximately 0.14 square kilometers (km\2\)) to
the area ensonified above the Level B harassment threshold (0.59 km\2\
for impact pile driving), we estimated that of the total number of
harbor seals that may be located within the greater Level B harassment
zone, approximately 24 percent will enter the smaller Level A
harassment zone (256 m) and stay in the zone long enough to incur
auditory injury. Thus, we assume that 24 percent of the total estimated
takes of harbor seals (96 individuals; see table 7) will be by Level A
harassment. Therefore, we are authorizing 23 takes of harbor seals by
Level A harassment and 73 takes by Level B harassment (table 7). Take
by Level A harassment for harbor porpoise was calculated in the same
way as for harbor seals. For otarriids, we are not authorizing take by
Level A harassment as the shutdown zones are much larger than the Level
A harassment zones for most activities, and the likely occurrence of
otariids in the action area is much lower than for harbor porpoise and
harbor seals.
[[Page 13588]]
Table 7--Take of Marine Mammals by Level A and Level B Harassment by Species and Stock and Percent of Stock Abundance
--------------------------------------------------------------------------------------------------------------------------------------------------------
Take by Level A Take by Level B Percent of
Species Stock harassment harassment Total take stock taken
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion............................. U.S............................... 0 34 34 <0.1
Steller sea lion................................ Eastern........................... 0 43 43 0.1
Harbor seal..................................... Oregon/Washington Coast........... 23 73 96 0.4
Harbor porpoise................................. Central Oregon.................... 11 20 31 0.4
--------------------------------------------------------------------------------------------------------------------------------------------------------
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.
USCG must ensure that construction supervisors and crews, the
monitoring team, and relevant USCG staff are trained prior to the start
of all pile driving activity, so that responsibilities, communication
procedures, monitoring protocols, and operational procedures are
clearly understood. New personnel joining during the project must be
trained prior to commencing work.
Pre- and Post-Activity Monitoring
<bullet> Monitoring must take place from 30 minutes prior to
initiation of pile driving activity (i.e., pre-clearance monitoring)
through 30 minutes post-completion of pile driving activity; and
<bullet> Pre-start clearance monitoring must be conducted during
periods of visibility sufficient for the lead protected species
observer (PSO) to determine that the shutdown zones indicated in table
8 are clear of marine mammals. Pile driving may commence following 30
minutes of observation when the determination is made that the shutdown
zones are clear of marine mammals.
Soft Start
USCG must use soft start techniques when impact pile driving. Soft
start requires contractors 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. A soft start must be implemented
at the start of each day's impact pile driving and at any time
following cessation of impact pile driving for a period of 30 minutes
or longer.
Shutdown Zones
USCG will establish shutdown zones for all pile driving activities.
The purpose of a shutdown zone is generally to define an area within
which shutdown of the activity will occur upon sighting of a marine
mammal (or in anticipation of an animal entering the defined area).
If a marine mammal is observed entering or within the shutdown
zones indicated in table 8, pile driving must be delayed or halted. For
in-water heavy machinery activities other than pile driving, if a
marine mammal comes within 10 m, work must stop and vessels must reduce
speed to the minimum level required to maintain steerage and safe
working conditions. A 10 m shutdown zone will also serve to protect
marine mammals from physical interactions with project vessels during
pile driving and other construction activities, such as barge
positioning or drilling. If an activity is delayed or halted due to the
presence of a marine mammal, the activity may not commence or resume
until either the animal has voluntarily exited and been visually
confirmed beyond the shutdown zone indicated in table 8 or 15 minutes
have passed without re-detection of the animal. Construction activities
must be halted upon observation of 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.
All marine mammals will be monitored in the Level B harassment
zones and throughout the area as far as visual monitoring can take
place. If a marine mammal enters the Level B harassment zone, in-water
activities will continue and the animal's presence within the estimated
harassment zone will be documented.
USCG will 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.
If a marine mammal species for which take is not authorized by this IHA
enters the shutdown zone, all in-water activities will cease until the
animal leaves the zone or has not been observed for at least 15
minutes, and USCG will notify NMFS about the species and precautions
taken. Pile driving will proceed if the non-IHA species is observed to
leave the Level B harassment zone or if 15 minutes have passed since
the last observation.
If shutdown and/or clearance procedures will result in an imminent
safety concern, as determined by USCG or its designated officials, the
in-water activity will be allowed to continue until the safety concern
has been addressed, and the animal will be continuously monitored.
[[Page 13589]]
Table 8--Shutdown Zones and Level B Harassment Zones
----------------------------------------------------------------------------------------------------------------
Minimum shutdown zone (m) Level B
Activity --------------------------------------------------------- harassment zone
VHF cetaceans Phocid Otariid (m)
----------------------------------------------------------------------------------------------------------------
Vibratory Removal................... 20 20 10 1,110
Vibratory Installation.............. 60 40 20 1,120
Impact Installation................. 200 100 100 720
----------------------------------------------------------------------------------------------------------------
Protected Species Observers
The placement of PSOs during all construction activities (described
in the Monitoring and Reporting section) will ensure that the entire
shutdown zone is visible. Should environmental conditions deteriorate
such that the entire shutdown zone will not be visible (e.g., fog,
heavy rain), pile driving will be delayed until the PSO is confident
marine mammals within the shutdown zone could be detected.
The USCG must employ PSOs and establish monitoring locations as
described in the application and the IHA. PSOs will monitor the full
shutdown zones and the Level B harassment zones to the extent
practicable. Monitoring zones provide utility for observing by
establishing monitoring protocols for areas adjacent to the shutdown
zones. Monitoring zones enable observers to be aware of and communicate
the presence of marine mammals in the project areas outside the
shutdown zones and thus prepare for a potential cessation of activity
should the animal enter the shutdown zone.
Bubble Curtain
A bubble curtain must be employed during all impact pile
installation. The bubble curtain must be deployed in a manner
guaranteed to distribute air bubbles around 100 percent of the piling
perimeter for the full depth of the water column. The lowest bubble
ring must be in contact with the mudline for the full circumference of
the ring. The weights attached to the bottom ring must ensure 100
percent mudline contact. No parts of the ring or other objects may
prevent full mudline contact. Air flow to the bubblers must be balanced
around the circumference of the pile.
Based on our evaluation of USCG's measures, as well as other
measures considered by NMFS, NMFS has determined that the mitigation
measures provide the means 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
Marine mammal monitoring must be conducted in accordance with the
conditions in this section and the IHA. Marine mammal monitoring during
pile driving activities must be conducted by PSOs meeting the following
requirements:
<bullet> PSOs must be independent of the activity contractor (for
example, employed by a subcontractor) and have no other assigned tasks
during monitoring periods;
<bullet> At least one PSO must have prior experience performing the
duties of a PSO during construction activity pursuant to a NMFS-issued
incidental take authorization;
<bullet> Other PSOs may substitute 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 will be designated. The lead
observer will be required to have prior experience performing the
duties of a PSO during construction activities pursuant to a NMFS-
issued incidental take authorization.
PSOs must have the following additional qualifications:
<bullet> Ability to conduct field observations and collect data
according to assigned protocols;
<bullet> Experience or training in the field identification of
marine mammals, including the identification of behaviors;
<bullet> Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
<bullet> Writing skills sufficient to prepare a report of
observations including but not limited to the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates, times
[[Page 13590]]
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.
USCG must assign a minimum of two PSOs to monitor during pile
driving. One PSO must be stationed at the pile driving site, and the
second PSO must be stationed at the best practicable location for
monitoring the Level A and Level B harassment zones. Possible PSOs
locations include the staging barges, on shore at the project site, or
at the entrance to the commercial dock area. All PSOs will have access
to high-quality binoculars, range finders to monitor distances, and a
compass to record bearing to animals as well as radios or cells phones
for maintaining contact with work crews.
Monitoring will be conducted 30 minutes before, during, and 30
minutes after all in water construction activities. In addition, PSOs
will record all incidents of marine mammal occurrence, regardless of
distance from activity, and will document any behavioral reactions in
concert with distance from piles being driven or removed. Pile driving
activities include the time to install or remove a single pile or
series of piles, as long as the time elapsed between uses of the pile
driving equipment is no more than 30 minutes.
USCG shall conduct briefings between construction supervisors and
crews, PSOs, USCG staff prior to the start of all pile driving
activities and when new personnel join the work. These briefings must
explain responsibilities, communication procedures, marine mammal
monitoring protocol, and operational procedures.
Reporting
A draft marine mammal monitoring report will be submitted to NMFS
within 90 days after the completion of pile driving and removal
activities, or 60 days prior to a requested date of issuance from any
future IHAs for projects at the same location, whichever comes first.
The report 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) and the total equipment
duration for vibratory removal 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: (1) Name of PSO who sighted the animal(s) and PSO location
and activity at the time of sighting; (2) Time of sighting; (3)
Identification of the animal(s) (e.g., genus/species, lowest possible
taxonomic level, or unidentifiable), PSO confidence in identification,
and the composition of the group if there is a mix of species; (4)
Distance and bearing of each marine mammal observed relative to the
pile being driven for each sightings (if pile driving was occurring at
time of sighting); (5) Estimated number of animals (min/max/best
estimate); (6) Estimated number of animals by cohort (adults,
juveniles, neonates, group composition, sex class, etc.); (7) Animal's
closest point of approach and estimated time spent within the
harassment zone; (8) Description of any marine mammal behavioral
observations (e.g., observed behaviors such as feeding or traveling),
including an assessment of behavioral responses thought to have
resulted from the activity (e.g., no response or changes in behavioral
state such as ceasing feeding, changing direction, flushing, or
breaching);
<bullet> Number of marine mammals detected within the harassment
zones and shutdown zones; by species; and,
<bullet> Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensured, 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 USCG must immediately
cease the specified activities and report the incident to the Office of
Protected Resources (OPR) (<a href="/cdn-cgi/l/email-protection#5505077b1c01057b183a3b3c213a273c3b320730253a272126153b3a34347b323a23"><span class="__cf_email__" data-cfemail="a5f5f78becf1f58be8cacbccd1cad7cccbc2f7c0d5cad7d1d6e5cbcac4c48bc2cad3">[email protected]</span></a>), NMFS and
to the West Coast Regional Stranding Coordinator as soon as feasible.
If the death or injury was clearly caused by the specified activity,
USCG must immediately cease the specified activities until NMFS is able
to review the circumstances of the incident and determine what, if any,
additional measures are appropriate to ensure compliance with the terms
of the IHA. The USCG 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
[[Page 13591]]
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, our analysis applies to all species listed in
table 1 for which take could occur, given that NMFS expects the
anticipated effects of the planned pile driving and removal on
different marine mammal stocks to be 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, NMFS has identified species-specific factors to
inform the analysis.
Pile driving activities associated with the USCG construction
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 and removal. Potential takes could occur if individuals
are present in the ensonified zone when these activities are underway.
The takes by Level B harassment will be due to potential behavioral
disturbance and TTS. Takes by Level A harassment will be due to
auditory injury. No serious injury or mortality is expected, even in
the absence of required mitigation measures, given the nature of the
activities. The potential for harassment will be further minimized
through the construction method and the implementation of the planned
mitigation measures (see Mitigation section). Take by Level A
harassment is authorized for harbor seals and harbor porpoise to
account for the possibility that an animal could enter a Level A
harassment zone prior to detection, and remain within that zone for a
duration long enough to incur auditory injury before being observed and
the USCG shutting down pile driving activity. The Level A harassment
zones identified in table 6 are based upon an animal's exposure to pile
driving of up to three of the largest steel piles per day. Given the
short duration to vibratory or impact drive each pile and breaks
between pile installations (to reset equipment and move piles into
place), an animal will have to remain within the area estimated to be
ensonified above the Level A harassment threshold for multiple hours.
This is highly unlikely given marine mammal movement in the area. The
number of takes by Level A harassment authorized is very low for both
marine mammal species. Any take by Level A harassment is expected to
arise from, at most, a small degree of auditory injury, i.e., minor
degradation (likely only a few dB) of hearing capabilities within
regions of hearing that align most completely with the energy produced
by vibratory and impact pile driving (i.e., the low-frequency region
below 2 kHz), not severe hearing impairment or impairment within the
ranges of greatest hearing sensitivity. Animals will 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. Due
to the small degree anticipated, any auditory injury incurred will not
be expected to affect the reproductive success or survival of any
individuals, much less result in adverse impacts on the species or
stock.
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. However, since the hearing sensitivity of
individuals that incur TTS is expected to recover completely within
minutes to hours, it is unlikely that the brief hearing impairment will
affect the individual's long-term ability to forage and communicate
with conspecifics, and will therefore not likely impact reproduction or
survival of any individual marine mammal, let alone adversely affect
rates of recruitment or survival of the species or stock.
Behavioral responses of marine mammals to pile driving in the
Siuslaw River are expected to be mild, short term, and temporary.
Marine mammals within the Level B harassment zones may not show any
visual cues they are disturbed by activities or they 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 will occur for only a portion of the project's
duration, any harassment will be temporary. Additionally, many of the
species present in region will only be present temporarily based on
seasonal patterns or during transit between other habitats. These
temporarily present species will be exposed to even smaller periods of
noise-generating activity, further decreasing the impacts.
Any impacts on marine mammal prey that will occur during USCG's
planned activity will 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.
For all species and stocks, take will occur within a limited,
confined area (adjacent to the project site) of the stock's range, and,
there are no known biologically important areas (BIAs) near the project
area that will be impacted by USCG's activities. While harbor seal is
the species most likely to occur within the immediate project area, the
nearest haulout is outside of the ensonified areas. There are known
haulout sites for harbor seals near the project area including across
the river and upriver from the action area, the closest being 400 m
from the project area. Although, the most recent survey taken of this
area was in 2014. There are no other haulouts in the immediate project
vicinity; the next closest haulout is 129 km away.
In addition, it is unlikely that minor noise effects in a small,
localized area of habitat will have any effect on the reproduction or
survival of any individuals, much less 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 would 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.
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> Take by Level A harassment is authorized for harbor seal
and harbor porpoise only and will be very small amounts and of a low
degree;
<bullet> For all species and stocks, the Siuslaw River is a very
small and peripheral part of their range;
<bullet> The intensity of anticipated takes by Level B harassment
is relatively low for all stocks. Level B harassment will be primarily
in the form of behavioral disturbance, resulting in avoidance of the
project areas around where impact or vibratory pile driving is
occurring, with some low-level TTS that may limit the detection of
acoustic cues for
[[Page 13592]]
relatively brief amounts of time in relatively confined footprints of
the activities;
<bullet> Effects on species that serve as prey for marine mammals
from the activities are expected to be short-term and, therefore, any
associated impacts on marine mammal feeding are not expected to result
in significant or long-term consequences for individuals, or to accrue
to adverse impacts on their populations;
<bullet> The project area does not overlap any areas of known
important habitat for marine mammals;
<bullet> The ensonified areas are very small relative to the
overall habitat ranges of all species and stocks; and,
<bullet> The lack of anticipated significant or long-term negative
effects to marine mammal habitat.
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 planned
activities 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. For all species, the
take is below one third of the population for all marine mammal stocks
(table 7).
Based on the analysis contained herein of the planned activity
(including the mitigation and monitoring measures) and the anticipated
take of marine mammals, NMFS finds that small numbers of marine mammals
will be taken relative to the population size of the affected species
or stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
determined that the total taking of affected species or stocks will not
have an unmitigable adverse impact on the availability of such species
or stocks for taking for subsistence purposes.
Endangered Species Act
Section 7(a)(2) of the ESA of 1973 (16 U.S.C. 1531 et seq.)
requires that each Federal agency insure that any action it authorizes,
funds, or carries out is not likely to jeopardize the continued
existence of any endangered or threatened species or result in the
destruction or adverse modification of designated critical habitat. To
ensure ESA compliance for the issuance of IHAs, NMFS consults
internally whenever we authorize take for endangered or threatened
species.
No incidental take of ESA-listed species is authorized or expected
to result from this activity. Therefore, NMFS has determined that
formal consultation under section 7 of the ESA is not required for this
action.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must 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 determined that the
issuance of the IHA qualifies to be categorically excluded from further
NEPA review.
Authorization
NMFS has issued an IHA to the USCG for the potential harassment of
small numbers of four marine mammal species incidental to the Station
Siuslaw River Construction Project in Florence, Oregon, that includes
the previously explained mitigation, monitoring and reporting
requirements.
Dated: March 19, 2025.
Catherine Marzin,
Acting Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2025-04995 Filed 3-24-25; 8:45 am]
BILLING CODE 3510-22-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on March 25, 2025.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.