Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to U.S. Coast Guard Construction in Astoria, Oregon, 66393-66409 [2023-20534]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 88, Number 186 (Wednesday, September 27, 2023)]
[Notices]
[Pages 66393-66409]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-20534]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XC044]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to U.S. Coast Guard Construction in 
Astoria, Oregon

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; proposed incidental harassment authorization; request 
for comments on proposed authorization and possible renewal.

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SUMMARY: NMFS has received a request from the United States Coast Guard 
(USCG) for authorization to take marine mammals incidental to the East 
Tongue Point (ETP) construction project in Astoria, Oregon. Pursuant to 
the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on 
its proposal to issue an incidental harassment authorization (IHA) to 
incidentally take marine mammals during the specified activities. NMFS 
is also requesting comments on a possible one-time, 1-year renewal that 
could be issued under certain circumstances and if all requirements are 
met, as described in Request for Public Comments at the end of this 
notice. NMFS will consider public comments prior to making any final 
decision on the issuance of the requested MMPA authorization and agency 
responses will be summarized in the final notice of our decision.

DATES: Comments and information must be received no later than October 
27, 2023.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service and should be submitted via email to 
[email protected]. 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: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. 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 https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities 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: 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

[[Page 66394]]

geographical region if certain findings are made and either regulations 
are proposed or, if the taking is limited to harassment, a notice of a 
proposed IHA is provided to the public for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of the species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of the takings are set forth. The definitions 
of all applicable MMPA statutory terms cited above are included in the 
relevant sections below.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an IHA) 
with respect to potential impacts on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for NAO 216-6A, which do not 
individually or cumulatively have the potential for significant impacts 
on the quality of the human environment and for which we have not 
identified any extraordinary circumstances that would preclude this 
categorical exclusion. Accordingly, NMFS has preliminarily determined 
that the issuance of the proposed IHA qualifies to be categorically 
excluded from further NEPA review.
    We will review all comments submitted in response to this notice 
prior to concluding our NEPA process or making a final decision on the 
IHA request.

Summary of Request

    On April 22, 2022, NMFS received a request from the USCG for an IHA 
to take marine mammals incidental to pile driving activity associated 
with the ETP construction in Astoria, Oregon. Following NMFS' review of 
the application, we received a revised version of the application on 
June 27, 2022. After finalizing construction details, the USCG 
submitted another revised version on May 26, 2023, followed by a final 
revised version on July 24, 2023, which was deemed adequate and 
complete on August 1, 2023. 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 Proposed Activity

Overview

    The USCG requested an IHA to homeport multiple new Fast Response 
Cutters (FRC) to support USCG District 13 at ETP in Astoria, OR (Figure 
1). This three-phased project entails both onshore and in-water 
construction activities to remove old piles, construct and improve 
facilities necessary for the long-term support of the FRC's and USCG 
mission. Phase 1 includes pile removal and demolition, dredging and 
shoreline rock improvements, phase 2 includes all pile driving and in 
water construction, and phase 3 includes all overwater and upland 
construction. The USCG completed a Homeport feasibility study in 2015 
to determine the best site for FRC and determined ETP was the most 
suitable site due to favorable currents and low exposure to wave 
action.
    This overall project is needed to improve or construct waterside 
and landslide facilities that will meet homeporting requirements of the 
FRCs. This includes the availability of logistics and support amenities 
for personnel, the ability of the new FRC docks/floats to accommodate 
the FRCs with all necessary operations on the boat while it is 
stationary at the dock, and the ability of the facility to provide for 
a long-term USCG presence for the economic life of its assets. 
Facilities at ETP are aged, outdated, and will require improvements to 
meet homeporting requirements.
    Of the stages of this project, the only part that may result in 
Level A and Level B harassment, and further analyzed in this notice is 
the in-water construction activities associated with impact pile 
driving (Phase 2). The USCG proposes installation of 30-inch (in) and 
36-in steel pipe piles for their new facilities with an estimated 52 
total days of impact pile driving. Pile driving will only occur within 
the Oregon Department of Fish and Wildlife (ODFW) approved in-water 
working window, however the proposed IHA will have a 1-year period of 
effectiveness. Phase 1 which includes dredging, pile removal and 
shoreline improvements and phase 3 involving only landside or over-
water improvements, do not result in take based on the noise analysis 
and implementation of mitigation measures by the USCG and therefore 
will not be discussed further.

Dates and Duration

    The ETP project is planned in a 3-phase approach with only phase 2 
covered under this IHA. The IHA would be valid from November 1, 2023 to 
October 31, 2024; however, pile driving would only occur in the ODFW 
in-water work window from November 1, 2023 to February 29, 2024.

Specific Geographic Region

    The project location is on the east side of the Tongue Point 
peninsula protruding into the Columbia River at approximately river 
mile 18. It lies in the northern portion of an industrial concrete pier 
area, formerly associated with a World War II-era U.S. Navy 
installation, just north of Highway 30 approximately 3 miles east of 
Astoria (Figure 1). The proposed project area is located within the 
Tongue Point Department of Labor Jobs Corps Center, which falls inside 
the urban growth boundary for Astoria. Various industrial and 
commercial uses, mostly for the marine industry, occur on the southern 
portion of the ETP site. To the north-northeast of the developed 
industrial area, the forested Tongue Point peninsula remains a 
designated natural area.
    The project area is bound by the main stem of the Columbia River to 
the north and west and by Cathlamet Bay to the south and east. Mott 
Island is located approximately 0.5 miles east of the project area and 
Mill Creek flows into the Columbia River immediately south of the 
capped landfill. Further south and east up the John Day channel, Lois 
Island lies across from the John Day River mouth and a protected deep-
water anchorage area is found. Moss and Lois Islands are part of the 
Lewis and Clark National Wildlife Refuge, which encompasses all islands 
approximately 27 miles upstream from the mouth of the Columbia River 
(USFWS 2020).
BILLING CODE 3510-22-P

[[Page 66395]]

[GRAPHIC] [TIFF OMITTED] TN27SE23.006

BILLING CODE 3510-22-C

Detailed Description of the Specified Activity

    Equipment and most materials needed to perform pier demolition and 
disposal, dredging, pile driving, pier, and floating dock construction 
will be mobilized via barges. It is anticipated that multiple barges 
may be present in the project or project staging areas at any time. The 
selected design-build contractor will mobilize equipment and materials 
based on the project phasing and task schedule to be determined once 
the project has been contracted. The overall project includes landslide 
improvements, waterside improvements, in-water construction, over-water 
construction, and upland construction. However, as previously stated 
this IHA only covers in-water construction associated with pile 
installation activities that could result in take of marine mammals.
    Piles will be installed during the in-water work window from 
November 1, 2023, through February 29, 2024, using impact hammers, per 
Table 1-1 and Table 1-2 in USCG's application. USCG estimates up to 
three piles will be driven each 8 hour workday, and the actual driving 
time for each pile could be as high as approximately 30 minutes. An 
estimated 52 total days of pile driving (not all consecutive) will 
occur during the in-water work window from November through February.
    Impact pile driving associated with the project is the only 
activity that could result in incidental take of marine mammals. 
Underwater noise generated during pile driving is dependent upon the 
impact energy produced by the pile driving hammer, the type and size of 
pile, water depth, and the substrate into

[[Page 66396]]

which the pile is being driven. Modeled pile driving scenarios 
accounted for the energy needed to drive the piles and utilized the two 
largest diameter pile sizes for the model as determined from 
engineering plans. A water depth of three meters was used, which is 
representative of the project area depths (Table 1).

                                         Table 1--Proposed Pile Driving
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                                                                                                      Estimated
        Pile size and type                 Method          Maximum piles      Activity duration        days of
                                                              per day                                    work
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36-inch steel pipe................  impact install......               3  40-45 blows per minute              52
                                                                           for 9 minutes.
30-inch steel pipe................  impact install......               3  40-45 blows per minute     ...........
                                                                           for 9 minutes.
----------------------------------------------------------------------------------------------------------------

    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions, instead of reprinting the information. Additional 
information regarding population trends and threats may be found in 
NMFS' Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and 
more general information about these species (e.g., physical and 
behavioral descriptions) may be found on NMFS' website (https://www.fisheries.noaa.gov/find-species).
    Table 2 lists all species or stocks for which take is expected and 
proposed to be authorized for this activity, and summarizes information 
related to the population or stock, including regulatory status under 
the MMPA and 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 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 and Alaska SARs. All values presented in Table 2 are 
the most recent available at the time of publication and are available 
online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

                                              Table 2--Species Likely Impacted by the Specified Activities
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                                                                                         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\
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                                                  Odontoceti (toothed whales, dolphins, and porpoises)
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 Family Phocoenidae (porpoises):
    Harbor Porpoise.................  Phocoena phocoena......  Northern Oregon/         -,-,N               21,487 (0.44, 15,123,         151      >=3.0
                                                                Washington Coast.                            2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
 sea lions):
    California Sea Lion.............  Zalophus californianus.  US.....................  -,-,N               257,606 (N/A, 233,515,     14,011       >321
                                                                                                             2014).
    Steller Sea Lion................  Eumetopias jubatus.....  Eastern................  -,-,N               43,201 (N/A, 43,201,        2,592        112
                                                                                                             2017).
Family Phocidae (earless seals)
    Harbor Seal.....................  Phoca vitulina.........  Oregon/Washington Coast  -,-,N               UNK...................        UND       10.6
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\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: https:// https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports/. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.

    As indicated above, all four species in Table 2 temporally and 
spatially co-occur with the activity to the degree that take is 
reasonably likely to occur. While killer whales (Orcinus orca), 
humpback whales (Megaptera novaeangliae), and

[[Page 66397]]

gray whales (Eschrichtius robustus) have been sighted off the Oregon 
coast, the USCG's project is located 23 km into the mouth of the 
Columbia River. Therefor 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.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Not all marine mammal species have equal 
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and 
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al. 
(2007, 2019) recommended that marine mammals be divided into hearing 
groups based on directly measured (behavioral or auditory evoked 
potential techniques) or estimated hearing ranges (behavioral response 
data, anatomical modeling, etc.). Note that no direct measurements of 
hearing ability have been successfully completed for mysticetes (i.e., 
low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al. (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in Table 3.

                  Table 3--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
            Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen   7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans           150 Hz to 160 kHz.
 (dolphins, toothed whales, beaked
 whales, bottlenose whales).
High-frequency (HF) cetaceans (true    275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 Cephalorhynchid, Lagenorhynchus
 cruciger & L. australis).
Phocid pinnipeds (PW) (underwater)     50 Hz to 86 kHz.
 (true seals).
Otariid pinnipeds (OW) (underwater)    60 Hz to 39 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section provides a discussion of the ways in which components 
of the specified activity may impact marine mammals and their habitat. 
The Estimated Take of Marine Mammals section later in this document 
includes a quantitative analysis of the number of individuals that are 
expected to be taken by this activity. The Negligible Impact Analysis 
and Determination section considers the content of this section, the 
Estimated Take of Marine Mammals section, and the Proposed Mitigation 
section, to draw conclusions regarding the likely impacts of these 
activities on the reproductive success or survivorship of individuals 
and whether those impacts are reasonably expected to, or reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival.
    Acoustic effects on marine mammals during the specified activity 
can occur from impact pile driving. The effects of underwater noise 
from USCG's proposed activities have the potential to result in Level A 
or Level B harassment of marine mammals in the action area.

Description of Sound Source

    The marine soundscape is comprised of both ambient and 
anthropogenic sounds. Ambient sound is defined as the all-encompassing 
sound in a given place and is usually a composite of sound from many 
sources both near and far. The sound level of an area is defined by the 
total acoustical energy being generated by known and unknown sources. 
These sources may include physical (e.g., waves, wind, precipitation, 
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced 
by marine mammals, fish, and invertebrates), and anthropogenic sound 
(e.g., vessels, dredging, aircraft, construction).
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals.
    In-water construction activities associated with the project would 
include vibratory pile removal, and impact and vibratory pile driving. 
The sounds produced by these activities fall into one of two general 
sound types: impulsive and non-impulsive. Impulsive sounds (e.g., 
explosions, gunshots, sonic booms, impact pile driving) are typically 
transient, brief (less than 1 second), broadband, and consist of high 
peak sound pressure with rapid rise time and rapid decay

[[Page 66398]]

(ANSI, 1986; NIOSH, 1998; ANSI, 2005; NMFS, 2018a). Non-impulsive 
sounds (e.g., aircraft, machinery operations such as drilling or 
dredging, vibratory pile driving, and active sonar systems) can be 
broadband, narrowband or tonal, brief or prolonged (continuous or 
intermittent), and typically do not have the high peak sound pressure 
with raid rise/decay time that impulsive sounds do (ANSI, 1995; NIOSH, 
1998; NMFS, 2018a). The distinction between these two sound types is 
important because they have differing potential to cause physical 
effects, particularly with regard to hearing (e.g., Ward 1997 in 
Southall et al., 2007).
    USCG propose to use impact pile driving to install new steel pipe 
piles associated with the ETP project. Impact hammers operate by 
repeatedly dropping a heavy piston onto a pile to drive the pile into 
the substrate. Sound generated by impact hammers is characterized by 
rapid rise times and high peak levels, a potentially injurious 
combination (Hastings and Popper, 2005). Peak sound pressure levels 
(SPLs) may be 180 dB or greater, but are generally 10 to 20 dB lower 
than SPLs generated during impact pile driving of the same-sized pile 
(Oestman et al., 2009). Rise time is slower, reducing the probability 
and severity of injury, and sound energy is distributed over a greater 
amount of time (Nedwell and Edwards, 2002; Carlson et al., 2005).
    The likely or possible impacts of USCG's proposed activity on 
marine mammals could involve both non-acoustic and acoustic stressors. 
Potential non-acoustic stressors could result from the physical 
presence of equipment and personnel; however, any impacts to marine 
mammals are expected to be primarily acoustic in nature. Acoustic 
stressors include effects of heavy equipment operation during pile 
driving.

Acoustic Impacts

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving is the primary means by which marine 
mammals may be harassed from the USCG's specified activity. In general, 
animals exposed to natural or anthropogenic sound may experience 
physical and psychological effects, ranging in magnitude from none to 
severe (Southall et al., 2007). In general, exposure to pile driving 
noise has the potential to result in auditory threshold shifts and 
behavioral reactions (e.g., avoidance, temporary cessation of foraging 
and vocalizing, changes in dive behavior). Exposure to anthropogenic 
noise can also lead to non-observable physiological responses, such as 
an increase in stress hormones. Additional noise in a marine mammal's 
habitat can mask acoustic cues used by marine mammals to carry out 
daily functions, such as communication and predator and prey detection. 
The effects of pile driving noise on marine mammals are dependent on 
several factors, including, but not limited to, sound type (e.g., 
impulsive vs. non-impulsive), the species, age and sex class (e.g., 
adult male vs. mom with calf), duration of exposure, the distance 
between the pile and the animal, received levels, behavior at time of 
exposure, and previous history with exposure (Wartzok et al., 2004; 
Southall et al., 2007). Here we discuss physical auditory effects 
(threshold shifts) followed by behavioral effects and potential impacts 
on habitat.
    NMFS defines a noise-induced threshold shift (TS) as a change, 
usually an increase, in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS, 2018). The amount of TS 
is customarily expressed in dB. TS can be permanent or temporary. As 
described in NMFS (2018), there are numerous factors to consider when 
examining the consequence of TS, including, but not limited to, the 
signal temporal pattern (e.g., impulsive or non-impulsive), likelihood 
an individual would be exposed for a long enough duration or to a high 
enough level to induce a TS, the magnitude of the TS, time to recovery 
(seconds to minutes or hours to days), the frequency range of the 
exposure (i.e., spectral content), the hearing and vocalization 
frequency range of the exposed species relative to the signal's 
frequency spectrum (i.e., how an animal uses sound within the frequency 
band of the signal; (e.g., Kastelein et al., 2014), and the overlap 
between the animal and the source (e.g., spatial, temporal, and 
spectral).
    Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS, 2018). Available data 
from humans and other terrestrial mammals indicate that a 40 dB 
threshold shift approximates PTS onset (see Ward et al., 1958, 1959; 
Ward, 1960; Kryter et al., 1966; Miller, 1974; Ahroon et al., 1996; 
Henderson et al., 2008). PTS levels for marine mammals are estimates, 
as with the exception of a single study unintentionally inducing PTS in 
a harbor seal (Kastak et al., 2008), there are no empirical data 
measuring PTS in marine mammals largely due to the fact that, for 
various ethical reasons, experiments involving anthropogenic noise 
exposure at levels inducing PTS are not typically pursued or authorized 
(NMFS, 2018).
    Temporary Threshold Shift (TTS)--TTS is a temporary, reversible 
increase in the threshold of audibility at a specified frequency or 
portion of an individual's hearing range above a previously established 
reference level (NMFS, 2018). Based on data from cetacean TTS 
measurements (see Southall et al., 2007), a TTS of 6 dB is considered 
the minimum threshold shift clearly larger than any day-to-day or 
session-to-session variation in a subject's normal hearing ability 
(Schlundt et al., 2000; Finneran et al., 2000, 2002). As described in 
Finneran (2015), marine mammal studies have shown the amount of TTS 
increases with cumulative sound exposure level (SELcum) in an 
accelerating fashion: At low exposures with lower SELcum, the amount of 
TTS is typically small and the growth curves have shallow slopes. At 
exposures with higher SELcum, the growth curves become steeper and 
approach linear relationships with the noise SEL.
    Depending on the degree (elevation of threshold in dB), duration 
(i.e., recovery time), and frequency range of TTS, and the context in 
which it is experienced, TTS can have effects on marine mammals ranging 
from discountable to serious (similar to those discussed in Masking, 
below). For example, a marine mammal may be able to readily compensate 
for a brief, relatively small amount of TTS in a non-critical frequency 
range that takes place during a time when the animal is traveling 
through the open ocean, where ambient noise is lower and there are not 
as many competing sounds present. Alternatively, a larger amount and 
longer duration of TTS sustained during a time when communication is 
critical for successful mother/calf interactions could have more 
serious impacts. We note that reduced hearing sensitivity as a simple 
function of aging has been observed in marine mammals, as well as 
humans and other taxa (Southall et al., 2007), so we can infer that 
strategies exist for coping with this condition to some degree, though 
likely not without cost.
    Many studies have examined noise-induced hearing loss in marine 
mammals (see Finneran (2015) and Southall et al. (2019) for summaries). 
For cetaceans, published data on the onset of TTS are limited to the 
captive bottlenose dolphin (Tursiops truncatus), beluga whale 
(Delphinapterus leucas), harbor porpoise, and Yangtze finless

[[Page 66399]]

porpoise (Neophocoena asiaeorientalis), and for pinnipeds in water, 
measurements of TTS are limited to harbor seals, elephant seals 
(Mirounga angustirostris), and California sea lions. These studies 
examine hearing thresholds measured in marine mammals before and after 
exposure to intense sounds. The difference between the pre-exposure and 
post-exposure thresholds can be used to determine the amount of 
threshold shift at various post-exposure times. The amount and onset of 
TTS depends on the exposure frequency. Sounds at low frequencies, well 
below the region of best sensitivity, are less hazardous than those at 
higher frequencies, near the region of best sensitivity (Finneran and 
Schlundt, 2013). At low frequencies, onset-TTS exposure levels are 
higher compared to those in the region of best sensitivity (i.e., a low 
frequency noise would need to be louder to cause TTS onset when TTS 
exposure level is higher), as shown for harbor porpoises and harbor 
seals (Kastelein et al., 2019a, 2019b, 2020a, 2020b). In addition, TTS 
can accumulate across multiple exposures, but the resulting TTS will be 
less than the TTS from a single, continuous exposure with the same SEL 
(Finneran et al., 2010; Kastelein et al., 2014; Kastelein et al., 
2015a; Mooney et al., 2009). This means that TTS predictions based on 
the total, cumulative SEL will overestimate the amount of TTS from 
intermittent exposures, such as sonars and impulsive sources. 
Nachtigall et al. (2018) and Finneran (2018) describe the measurements 
of hearing sensitivity of multiple odontocete species (bottlenose 
dolphin, harbor porpoise, beluga, and false killer whale (Pseudorca 
crassidens)) when a relatively loud sound was preceded by a warning 
sound. These captive animals were shown to reduce hearing sensitivity 
when warned of an impending intense sound. Based on these experimental 
observations of captive animals, the authors suggest that wild animals 
may dampen their hearing during prolonged exposures or if conditioned 
to anticipate intense sounds. Another study showed that echolocating 
animals (including odontocetes) might have anatomical specializations 
that might allow for conditioned hearing reduction and filtering of 
low-frequency ambient noise, including increased stiffness and control 
of middle ear structures and placement of inner ear structures (Ketten 
et al., 2021). Data available on noise-induced hearing loss for 
mysticetes are currently lacking (NMFS, 2018).
    Behavioral Harassment--Exposure to noise from pile driving and 
removal also has the potential to behaviorally disturb marine mammals. 
Available studies show wide variation in response to underwater sound; 
therefore, it is difficult to predict specifically how any given sound 
in a particular instance might affect marine mammals perceiving the 
signal. If a marine mammal does react briefly to an underwater sound by 
changing its behavior or moving a small distance, the impacts of the 
change are unlikely to be significant to the individual, let alone the 
stock or population. However, if a sound source displaces marine 
mammals from an important feeding or breeding area for a prolonged 
period, impacts on individuals and populations could be significant 
(e.g., Lusseau and Bejder, 2007; Weilgart, 2007; NRC, 2005).
    Disturbance may result in changing durations of surfacing and 
dives, number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities; changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping); and, avoidance of areas where sound sources are located. 
Pinnipeds may increase their haul out time, possibly to avoid in-water 
disturbance (Thorson and Reyff, 2006). Behavioral responses to sound 
are highly variable and context-specific and any reactions depend on 
numerous intrinsic and extrinsic factors (e.g., species, state of 
maturity, experience, current activity, reproductive state, auditory 
sensitivity, time of day), as well as the interplay between factors 
(e.g., Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 
2007; Weilgart, 2007; Archer et al., 2010). Behavioral reactions can 
vary not only among individuals but also within an individual, 
depending on previous experience with a sound source, context, and 
numerous other factors (Ellison et al., 2012), and can vary depending 
on characteristics associated with the sound source (e.g., whether it 
is moving or stationary, number of sources, distance from the source). 
In general, pinnipeds seem more tolerant of, or at least habituate more 
quickly to, potentially disturbing underwater sound than do cetaceans, 
and generally seem to be less responsive to exposure to industrial 
sound than most cetaceans. Please see Appendices B-C of Southall et 
al., (2007) for a review of studies involving marine mammal behavioral 
responses to sound.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the appearance of secondary 
indicators (e.g., bubble nets or sediment plumes), or changes in dive 
behavior. As for other types of behavioral response, the frequency, 
duration, and temporal pattern of signal presentation, as well as 
differences in species sensitivity, are likely contributing factors to 
differences in response in any given circumstance (e.g., Croll et al., 
2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko et al., 
2007). A determination of whether foraging disruptions incur fitness 
consequences would require information on or estimates of the energetic 
requirements of the affected individuals and the relationship between 
prey availability, foraging effort and success, and the life history 
stage of the animal.
    Stress responses--An animal's perception of a threat may be 
sufficient to trigger stress responses consisting of some combination 
of behavioral responses, autonomic nervous system responses, 
neuroendocrine responses, or immune responses (e.g., Seyle, 1950; 
Moberg, 2000). In many cases, an animal's first and sometimes most 
economical (in terms of energetic costs) response is behavioral 
avoidance of the potential stressor. Autonomic nervous system responses 
to stress typically involve changes in heart rate, blood pressure, and 
gastrointestinal activity. These responses have a relatively short 
duration and may or may not have a significant long-term effect on an 
animal's fitness.
    Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction, altered metabolism, reduced immune 
competence, and behavioral disturbance (e.g., Moberg, 1987; Blecha, 
2000). Increases in the circulation of glucocorticoids are also equated 
with stress (Romano et al., 2004).
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and ``distress'' is the cost of 
the response. During a stress response, an animal uses glycogen stores 
that can be quickly replenished once the stress is alleviated. In such 
circumstances, the cost of the stress response would not pose serious

[[Page 66400]]

fitness consequences. However, when an animal does not have sufficient 
energy reserves to satisfy the energetic costs of a stress response, 
energy resources must be diverted from other functions. This state of 
distress will last until the animal replenishes its energetic reserves 
sufficient to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well studied through 
controlled experiments and for both laboratory and free-ranging animals 
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003; 
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to 
exposure to anthropogenic sounds or other stressors and their effects 
on marine mammals have also been reviewed (Fair and Becker, 2000; 
Romano et al., 2002b) and, more rarely, studied in wild populations 
(e.g., Romano et al., 2002a). For example, Rolland et al., (2012) found 
that noise reduction from reduced ship traffic in the Bay of Fundy was 
associated with decreased stress in North Atlantic right whales. These 
and other studies lead to a reasonable expectation that some marine 
mammals will experience physiological stress responses upon exposure to 
acoustic stressors and that it is possible that some of these would be 
classified as ``distress.'' In addition, any animal experiencing TTS 
would likely also experience stress responses (NRC, 2003), however 
distress is an unlikely result of this project based on observations of 
marine mammals during previous, similar projects in the area.
    Masking--Sound can disrupt behavior through masking, or interfering 
with, an animal's ability to detect, recognize, or discriminate between 
acoustic signals of interest (e.g., those used for intraspecific 
communication and social interactions, prey detection, predator 
avoidance, navigation) (Richardson et al., 1995). Masking occurs when 
the receipt of a sound is interfered with by another coincident sound 
at similar frequencies and at similar or higher intensity, and may 
occur whether the sound is natural (e.g., snapping shrimp, wind, waves, 
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar, 
seismic exploration) in origin. The ability of a noise source to mask 
biologically important sounds depends on the characteristics of both 
the noise source and the signal of interest (e.g., signal-to-noise 
ratio, temporal variability, direction), in relation to each other and 
to an animal's hearing abilities (e.g., sensitivity, frequency range, 
critical ratios, frequency discrimination, directional discrimination, 
age or TTS hearing loss), and existing ambient noise and propagation 
conditions. Masking of natural sounds can result when human activities 
produce high levels of background sound at frequencies important to 
marine mammals. Conversely, if the background level of underwater sound 
is high (e.g., on a day with strong wind and high waves), an 
anthropogenic sound source would not be detectable as far away as would 
be possible under quieter conditions and would itself be masked.
    Airborne Acoustic Effects--Although pinnipeds are known to haul out 
regularly near Astoria, we believe that incidents of take resulting 
solely from airborne sound are unlikely due to the sheltered proximity 
between the proposed project area and these haul-out sites which are at 
least 3 miles (4.8 kilometers) away and not in the acoustic zones that 
could be directly affect by noise disturbance. There is a possibility 
that an animal could surface in-water, but with head out, within the 
area in which airborne sound exceeds relevant thresholds and thereby be 
exposed to levels of airborne sound that we associate with harassment, 
but any such occurrence would likely be accounted for in our estimation 
of incidental take from underwater sound. Therefore, authorization of 
incidental take resulting from airborne sound for pinnipeds is not 
warranted, and airborne sound is not discussed further here. Cetaceans 
are not expected to be exposed to airborne sounds that would result in 
harassment as defined under the MMPA.

Marine Mammal Habitat Effects

    The USCG's construction activities could have localized, temporary 
impacts on marine mammal habitat and their prey by increasing in-water 
sound pressure levels and slightly decreasing water quality. However, 
the proposed location is not heavily used by marine mammals and is in 
close proximity to a heavily trafficked industrial area. Construction 
activities are of short duration and would likely have temporary 
impacts on marine mammal habitat through increases in underwater and 
airborne sound. Increased noise levels may affect acoustic habitat (see 
Masking discussion above) and adversely affect marine mammal prey in 
the vicinity of the project area (see discussion below). During impact 
and vibratory pile driving, elevated levels of underwater noise would 
ensonify the project area where both fish and mammals occur and could 
affect foraging success.
    Temporary and localized increase in turbidity near the seafloor 
would occur in the immediate area surrounding the area where piles are 
installed. In general, turbidity associated with pile installation is 
localized to about a 25 feet (ft) (7.6 meter) radius around the pile 
(Everitt et al., 1980). The sediments of the project site will settle 
out rapidly when disturbed. Cetaceans are not expected to be close 
enough to the pile driving areas to experience effects of turbidity, 
and any pinnipeds could avoid localized areas of turbidity. Local 
strong currents are anticipated to disburse any additional suspended 
sediments produced by project activities at moderate to rapid rates 
depending on tidal stage. Therefore, we expect the impact from 
increased turbidity levels to be discountable to marine mammals and do 
not discuss it further.

In-Water Construction Effects on Potential Foraging Habitat

    The proposed activities would result in a minor loss of habitat and 
potentially change underwater features for fish, but these changes are 
insignificant and limited to the area of redevelopment. The total 
seafloor area likely impacted by the project is relatively small 
compared to the available habitat in the Columbia River Gorge and on 
the Pacific Coast and does not include any Biologically Important Areas 
(BIA) or other habitat of known importance. The area is highly 
influenced by anthropogenic activities. Additionally, the total 
seafloor area affected by pile installation and removal is a small area 
compared to the vast foraging area available to marine mammals in the 
area. At best, the impact area provides marginal foraging habitat for 
marine mammals and fishes. Furthermore, pile driving at the project 
site would not obstruct movements or migration of marine mammals.
    Avoidance by potential prey (i.e., fish) of the immediate area due 
to the temporary loss of this foraging habitat is also possible. The 
duration of fish avoidance of this area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated. Any behavioral avoidance by fish of the 
disturbed area would still leave significantly large areas of fish and 
marine mammal foraging habitat in the nearby vicinity.

Effects on Potential Prey

    Sound may affect marine mammals through impacts on the abundance, 
behavior, or distribution of prey species (e.g., crustaceans, 
cephalopods, fish, zooplankton, etc.). Marine mammal prey varies by 
species, season, and location.

[[Page 66401]]

However, impacts to prey will be limited to the construction window of 
November 1, 2023 through February 29, 2024 to reduce impacts to fish 
species in the area. Here, we describe studies regarding the effects of 
noise on known marine mammal prey.
    Fish utilize the soundscape and components of sound in their 
environment to perform important functions such as foraging, predator 
avoidance, mating, and spawning (e.g., Zelick and Mann, 1999; Fay, 
2009). Depending on their hearing anatomy and peripheral sensory 
structures, which vary among species, fishes hear sounds using pressure 
and particle motion sensitivity capabilities and detect the motion of 
surrounding water (Fay et al., 2008). The potential effects of noise on 
fishes depends on the overlapping frequency range, distance from the 
sound source, water depth of exposure, and species-specific hearing 
sensitivity, anatomy, and physiology. Key impacts to fishes may include 
behavioral responses, hearing damage, barotrauma (pressure-related 
injuries), and mortality.
    Fish react to sounds that are especially strong and/or intermittent 
low-frequency sounds, and behavioral responses, such as flight or 
avoidance, are the most likely effects. Short duration, sharp sounds 
can cause overt or subtle changes in fish behavior and local 
distribution. The reaction of fish to noise depends on the 
physiological state of the fish, past exposures, motivation (e.g., 
feeding, spawning, migration), and other environmental factors. 
Hastings and Popper (2005) identified several studies that suggest fish 
may relocate to avoid certain areas of sound energy. Additional studies 
have documented effects of pile driving on fish, although several are 
based on studies in support of large, multiyear bridge construction 
projects (e.g., Scholik and Yan, 2001, 2002; Popper and Hastings, 
2009). Several studies have demonstrated that impulse sounds might 
affect the distribution and behavior of some fishes, potentially 
impacting foraging opportunities or increasing energetic costs (e.g., 
Fewtrell and McCauley, 2012; Pearson et al., 1992; Skalski et al., 
1992; Santulli et al., 1999; Paxton et al., 2017). However, some 
studies have shown no or slight reaction to impulse sounds (e.g., Pena 
et al., 2013; Wardle et al., 2001; Jorgenson and Gyselman, 2009; Popper 
et al., 2015).
    SPLs of sufficient strength have been known to cause injury to fish 
and fish mortality. However, in most fish species, hair cells in the 
ear continuously regenerate and loss of auditory function likely is 
restored when damaged cells are replaced with new cells. Halvorsen et 
al., (2012a) showed that a TTS of 4-6 dB was recoverable within 24 
hours for one species. Impacts would be most severe when the individual 
fish is close to the source and when the duration of exposure is long. 
Injury caused by barotrauma can range from slight to severe and can 
cause death, and is most likely for fish with swim bladders. Barotrauma 
injuries have been documented during controlled exposure to impact pile 
driving (Halvorsen et al., 2012b; Casper et al., 2013).
    The most likely impact to fish from pile driving activities at the 
project areas would be temporary behavioral avoidance of the area. The 
duration of fish avoidance of an area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated.
    Construction activities, in the form of increased turbidity, have 
the potential to adversely affect forage fish in the project area. 
Forage fish form a significant prey base for many marine mammal species 
that occur in the project area. Increased turbidity is expected to 
occur in the immediate vicinity (on the order of 10 ft (3 meters (m)) 
or less) of construction activities. However, suspended sediments and 
particulates are expected to dissipate quickly within a single tidal 
cycle. Given the limited area affected and high tidal dilution rates, 
any effects on forage fish are expected to be minor or negligible. 
Finally, exposure to turbid waters from construction activities is not 
expected to be different from the current exposure; fish and marine 
mammals in the Columbia River are routinely exposed to substantial 
levels of suspended sediment from natural and anthropogenic sources.
    In summary, given the short-term and limited duration of sound 
associated with pile driving events and the relatively small areas 
being affected, pile driving activities associated with the proposed 
action are not likely to have a permanent adverse effect on any fish 
habitat, or populations of fish species. Any behavioral avoidance by 
fish of the disturbed area would be temporary and would still leave 
significantly large areas of fish and marine mammal foraging habitat in 
the nearby vicinity. Additionally, all in-water work will occur during 
the winter, when marine resident fish species are only present in 
limited numbers. Thus, we conclude that impacts of the specified 
activity are not likely to have more than short-term adverse effects on 
any prey habitat or populations of prey species. Further, any impacts 
to marine mammal habitat are not expected to result in significant or 
long-term consequences for individual marine mammals, or to contribute 
to adverse impacts on their populations.

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform both 
NMFS' consideration of ``small numbers,'' and the negligible impact 
determinations.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes would primarily be by Level B harassment, as use 
of the acoustic sources (i.e., impact pile driving) has the potential 
to result in disruption of behavioral patterns for individual marine 
mammals. There is also some potential for auditory injury (Level A 
harassment) to result. 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 thresholds above which NMFS believes the best 
available science indicates marine mammals will be behaviorally 
harassed or incur some degree of permanent hearing impairment; (2) the 
area or volume of water that will be ensonified above these levels in a 
day; (3) the density or occurrence of marine mammals within these 
ensonified areas; and, (4) the number of days of activities. We note 
that while these factors can contribute to a basic calculation to 
provide an initial prediction of potential takes, additional 
information that can qualitatively inform take estimates is also 
sometimes available (e.g., previous monitoring results or average group 
size). Below, we describe the factors considered here in more detail 
and present the proposed take estimates.

[[Page 66402]]

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment).
    Level B Harassment--Though significantly driven by received level, 
the onset of behavioral disturbance from anthropogenic noise exposure 
is also informed to varying degrees by other factors related to the 
source or exposure context (e.g., frequency, predictability, duty 
cycle, duration of the exposure, signal-to-noise ratio, distance to the 
source), the environment (e.g., bathymetry, other noises in the area, 
predators in the area), and the receiving animals (hearing, motivation, 
experience, demography, life stage, depth) and can be difficult to 
predict (e.g., Southall et al., 2007, 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.
    USCG's proposed activity includes the use impulsive (impact pile 
driving) sources, and therefore the RMS SPL threshold of 160 dB re 1 
[mu]Pa is applicable.
    Level A harassment--NMFS' Technical Guidance for Assessing the 
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0) 
(Technical Guidance, 2018) identifies dual criteria to assess auditory 
injury (Level A harassment) to five different marine mammal groups 
(based on hearing sensitivity) as a result of exposure to noise from 
two different types of sources (impulsive or non-impulsive). USCG's 
proposed activity includes the use of impulsive (impact pile driving) 
sources.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS' 2018 Technical Guidance, which may be accessed at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                    PTS onset acoustic thresholds \*\ (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
                                          LEOW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
  National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
  incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
  ``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
  generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
  the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
  and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
  be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
  it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that are used in estimating the area ensonified above the 
acoustic thresholds, including source levels and transmission loss 
coefficient.
    Underwater sound propagation modeling was completed by USCG using 
dBSea, a software developed by Marshall Day Acoustics for the modeling 
of underwater sound propagation in a variety of environments. The model 
was built 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. Noise levels were calculated to the extent of the bathymetry 
area. To examine results in more detail, levels may be plotted in cross 
sections, or a detailed spectrum may be extracted at any point in the 
calculation area. Levels were calculated in third octave bands from 
12.5 (hertz) Hz to 20 kHz. Please refer to Acoustic Assessment included 
in USCG's application for additional details on the modeling principles 
and assumptions.
    The representative acoustic modeling scenarios were derived from 
descriptions of the expected construction activities through 
consultations between the USCG project design and engineering teams. 
The scenarios modeled were ones where potential underwater noise 
impacts of marine species were anticipated and included impact pile 
driving associated with pier installation. All modeling scenarios occur 
at a representative location. This location was selected so that the 
effects of sound propagation at the range of water column depths 
occurring within the project area could be evaluated.
    The USCG opted to perform their own acoustic modeling for the Level 
A and Level B harassment isopleths as they had site specific 
information to input into the model, which may assist in

[[Page 66403]]

providing more accurate results Than, for example, use of NMFS' User 
Spreadsheet tool, which is a relatively simple tool that cannot 
incorporate site-specific environmental information. The modeling used 
by USCG takes into account bathymetry, geo-acoustic properties of sub-
bottom sediments, and sound speed profile. NMFS has reviewed USCG's 
modeling and determined that it is acceptable for use here.
    A summary of construction and operational scenarios included in the 
underwater acoustic modeling analysis is provided in the Acoustic 
Assessment and summarized in Table 5 below. The pile diameters selected 
for the impact pile driving modeling scenarios were based on maximum 
project design considerations approximated by USCG. The Level A and 
Level B harassment isopleths for the proposed activities are shown in 
Table 6.

                               Table 5--Source Levels for Impact Pile Installation
----------------------------------------------------------------------------------------------------------------
            Pile size              Peak SPLs (dB)   RMS SPLs (dB)    SELss (dB)                Source
----------------------------------------------------------------------------------------------------------------
36-in pile.......................             208             190             180  Caltrans 2020.
30-in pile.......................             210             190             177  Caltrans 2020.
----------------------------------------------------------------------------------------------------------------


                    Table 6--Level A and Level B Harassment Isopleths for Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
                                                           Level A harassment zones (m)
                                                 ------------------------------------------------     Level B
                    Activity                                          Phocid          Otariid       harassment
                                                   HF cetaceans      pinnipeds       pinnipeds       zone (m)
----------------------------------------------------------------------------------------------------------------
36-in pile......................................             287             197               0             602
30-in pile......................................             213             130               0             602
----------------------------------------------------------------------------------------------------------------

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 proposed for authorization. The 
USCG proposed using 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 U.S. 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 Columbia 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.

Steller Sea Lion, California Sea Lion and Harbor Seal

    For Steller sea lions, California sea lions, and harbor seals, the 
numbers of individuals were referenced from Washington Department of 
Fish and Wildlife's (WDFW) surveys from 2000-2014 at the South Jetty 
for the months of in water work (November through February) and 
averaged to get an estimated daily count (Table 7). While animals were 
surveyed at the prominent haul out site along the South Jetty, since 
the ETP site is close to the mouth of the river and the South Jetty, we 
assumed each of these estimates represents a good proxy for the total 
number of individuals that could be present in the project vicinity. We 
derived potential take estimates from the average abundance recorded 
over the specified period.

                          Table 7--Pinniped Counts From the South Jetty From 2000-2014
                                                   [WDFW 2014]
----------------------------------------------------------------------------------------------------------------
                                                               California   California
                                Steller sea     Steller sea     Sea lion     sea lion   Harbor seal  Harbor seal
                              lion (monthly)   lion (daily)    (monthly)     (daily)     (monthly)     (daily)
----------------------------------------------------------------------------------------------------------------
November....................           1,663              55        1,214           40            0            0
December....................           1,112              36          725           23           57            2
January.....................             249               8           10          0.3            0            0
February....................             259               9           28            1            1         0.04
Average (all months)........             821              27          494           16           15          0.5
----------------------------------------------------------------------------------------------------------------

    To calculate the total estimated takes, we multiplied the estimated 
days of activity by the associated average daily pinniped counts 
(monthly count/days of the month and averaged across all months) for 
each species (Table 8).

[[Page 66404]]



                                  Table 8--Estimated Take of Steller Sea Lions, California Sea Lions, and Harbor Seals
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                            Steller sea  Steller sea   California   California
                                                                 Days of        lion         lion       sea lion     sea lion   Harbor seal  Harbor seal
                     Pile type and method                        activity     average     calculated    average     calculated    average     calculate
                                                                               count         take        count         take        count         take
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in Steel Pile Impact Installation.........................           52           27        1,404           16          832          0.5           26
30-in Steel Pile Impact Installation
--------------------------------------------------------------------------------------------------------------------------------------------------------

    There is some potential for take by Level A harassment of harbor 
seals due to the largest zone being approximately 200 m and because of 
the cryptic nature and assumed lower detectability of harbor seals at 
this distance. Based on the relative proportion of the area expected to 
be ensonified above the Level A harassment threshold for phocid 
pinnipeds from impact pile driving (approximately 0.36 square 
kilometers (km\2\)) to the area ensonified above the Level B harassment 
threshold (1.1 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 33 percent would approach the 
pile driving activities closer and enter the smaller Level A harassment 
zone (197 m). Thus, we assume that 33 percent of the total estimated 
takes of harbor seals (26 individuals; see Table 9) would be by Level A 
harassment. Therefore, we are proposing to authorize 9 takes of harbor 
seals by Level A harassment and 17 takes by Level B harassment (Table 
10).
    The Level A harassment zone for otariid pinnipeds is 0 m. The USCG 
would be required to enforce a minimum shutdown zone of 10 m for these 
species. At that close range, the USCG would be able to detect 
California sea lions and Steller sea lions and implement the required 
shutdown measures before any sea lions could enter the Level A 
harassment zone. Therefore, no takes of California sea lions or Steller 
sea lions by Level A harassment are requested or proposed to be 
authorized.

Harbor Porpoise

    Harbor porpoises are regularly observed in the coastal waters near 
the mouth of the Columbia River and are known to occur year-round, 
although this project occurs farther upstream in the Columbia River. 
Their nearshore abundance peaks with anchovy presence, which is 
generally June through October. However, there was one recorded 
sighting of a harbor porpoise in the project area east of the jetties 
in the September-November timeframe (OBIS-SEAMAP 2019). During 
monitoring for pile driving at the Columbia River Jetty System which is 
at the mouth of the Columbia River approximately 23 km from the USCG's 
proposed action area, over the course of a 5 day monitoring period, 
observers detected 5 harbor porpoises (Grette Associates 2016). 
Additionally we reviewed monitoring reports from four recent projects 
in the nearby area (Army Corps of Engineers King Pile Markers and Sand 
Island Pile Dike Test Piles, and Phase 1 and 2 of the City of Astoria 
Bridge Replacement which can be found at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities#active-authorizations). 
Only one project with activities occurring over 15 days had eight 
sightings of harbor porpoise at Sand Island Dike.
    Given that, there is some potential for harbor porpoise to be 
present near the project area, and based on the previously mentioned 
monitoring reports sighting data, we calculated that harbor porpoise 
could enter the Level B harassment zone every other day of pile driving 
(or 0.5/day). To calculate the total estimated takes by Level B 
harassment, we multiplied the estimated days of activity by the 
associated daily harbor porpoise rate (Table 10).
    There is also some potential for take by Level A harassment of 
harbor porpoise due to the largest zone being approximately 300 m and 
because of the cryptic nature and assumed lower detectability of harbor 
porpoise at this distance. The USCG anticipates that 12 harbor 
porpoises during impact driving could be taken by Level A harassment. 
Take by Level A harassment for harbor porpoise was calculated in the 
same way it was for harbor seals. In total, we are proposing to 
authorize take of 26 harbor porpoises (Table 10).

               Table 10--Proposed Take of Marine Mammals by Level A and Level B Harassment by Species, Stock and Percent of Take by Stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    Proposed take   Proposed take     Total
                    Species                                   Stock                  by Level A      by Level B      proposed      Stock      Percent of
                                                                                     harassment      harassment        take      abundance      stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor Porpoise...............................  Northern Oregon/Washington Coast.              12              14           26       21,487          0.1
California sea lion...........................  U.S..............................               0             832          832      257,606          0.3
Steller sea lion..............................  Eastern..........................               0           1,404        1,404       43,201          3.2
Harbor seal...................................  Oregon/Washington Coast..........               9              17           26       24,732          0.1
--------------------------------------------------------------------------------------------------------------------------------------------------------

Proposed Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks, and their habitat (50 CFR 
216.104(a)(11)).

[[Page 66405]]

    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.

Time Restrictions

    The USCG has proposed 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, 
ODFW requires all in-water construction be limited to the months of 
November through February to minimize impacts to ESA listed fish 
species.

Mitigation Measures

    USCG must follow mitigation measures as specified below:
     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;
     Employ Protected Species Observers (PSOs) and establish 
monitoring locations as described in the application and the IHA. USCG 
must monitor the project area to the maximum extent possible based on 
the required number of PSOs, required monitoring locations, and 
environmental conditions. For all pile driving, at least one PSO must 
be used. The PSO will be stationed as close to the activity as 
possible;
     The placement of the PSOs during all pile driving activity 
will ensure that the entire shutdown zone, see Table 11, is visible 
during pile driving activities. Should environmental conditions 
deteriorate such that marine mammals within the entire shutdown zone 
will not be visible (e.g., fog, heavy rain), pile driving and removal 
must be delayed until the PSO is confident marine mammals within the 
shutdown zone could be detected;
     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;
     Pre-start clearance monitoring must be conducted during 
periods of visibility sufficient for the lead PSO to determine that the 
shutdown zones indicated in Table 11 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;
     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; and
     If a marine mammal is observed entering or within the 
shutdown zones indicated in Table 11, pile driving must be delayed or 
halted. If pile driving 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 (Table 11) or 15 minutes have passed without re-detection 
of the animal.

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 would occur upon sighting of a marine 
mammal (or in anticipation of an animal entering the defined area). 
Shutdown zones would be based upon the Level A harassment zone for each 
pile size/type where applicable, as shown in Table 11.
    For in-water heavy machinery activities other than pile driving, if 
a marine mammal comes within 10 m, work will stop and vessels will 
reduce speed to the minimum level required to maintain steerage and 
safe working conditions. A 10 m shutdown zone would 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 11 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 not covered under 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 
NMFS will be notified about 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 would 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 66406]]



                                  Table 11--Shutdown Zones and Monitoring Zones
----------------------------------------------------------------------------------------------------------------
                                                               Minimum shutdown zone (m)
                       Activity                       -------------------------------------------   Harassment
                                                         HF cetaceans      Phocid      Otariid       zone (m)
----------------------------------------------------------------------------------------------------------------
36-in Impact Installation............................              300           50           10             610
30-in Impact Installation............................              220           50           10             610
----------------------------------------------------------------------------------------------------------------

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 would not be visible (e.g., fog, 
heavy rain), pile driving would be delayed until the PSO is confident 
marine mammals within the shutdown zone could be detected.
    PSOs 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.
    Based on our evaluation of USCG's planned measures, as well as 
other measures considered by NMFS, NMFS has preliminarily 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.

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:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     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);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and,
     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 will be conducted by PSOs meeting the following 
requirements:
     PSOs must be independent of the activity contractor (for 
example, employed by a subcontractor) and have no other assigned tasks 
during monitoring periods;
     At least one PSO will have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization;
     Other PSOs may substitute education (degree in biological 
science or related field) or training for experience; and
     Where a team of three or more PSOs is required, a lead 
observer or monitoring coordinator will be designated. The lead 
observer will be required to have prior experience working as a marine 
mammal observer during construction.
    PSOs must have the following additional qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     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
     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 employ three PSOs during all pile driving 
activities depending on the size of the monitoring and shutdown zones. 
A minimum of one PSO must be assigned to monitor waters surrounding the 
active pile driving location.
     USCG must establish the following monitoring locations 
with the best views of monitoring zones as described below, in the IHA, 
and USCG's application.
     PSOs would be deployed in strategic locations around the 
harassment zone at all times during in-water pile driving. PSOs will be 
positioned at locations that provide full views of the impact hammering 
monitoring zones and the shutdown zones. PSOs will be stationed on the 
staging barges, on shore at the project site, and at the entrance to 
the commercial dock area at ETP. All PSOs will have access to high-
quality

[[Page 66407]]

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 will 
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:
     Dates and times (begin and end) of all marine mammal 
monitoring;
     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);
     PSO locations during marine mammal monitoring;
     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;
     Upon observation of a marine mammal, the following 
information:
     Name of PSO who sighted the animal(s) and PSO location and 
activity at the time of sighting;
     Time of sighting;
     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;
     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);
     Estimated number of animals (min/max/best estimate);
     Estimated number of animals by cohort (adults, juveniles, 
neonates, group composition, sex class, etc.);
     Animal's closest point of approach and estimated time 
spent within the harassment zone;
     Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as feeding or traveling), including an 
assessment of behavioral responses thought to have resulted from the 
activity (e.g., no response or changes in behavioral state such as 
ceasing feeding, changing direction, flushing, or breaching);
     Number of marine mammals detected within the harassment 
zones and shutdown zones; by species;
     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; and
    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) ([email protected]), 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:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and
     General circumstances under which the animal was 
discovered.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any impacts or responses (e.g., intensity, duration), 
the context of any impacts or responses (e.g., critical reproductive 
time or location, foraging impacts affecting energetics), as well as 
effects on habitat, and the likely effectiveness of the mitigation. We 
also assess the number, intensity, and context of estimated takes by 
evaluating this information relative to population status. Consistent 
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338, 
September 29, 1989), the impacts from other past and ongoing 
anthropogenic activities are incorporated into this analysis via their 
impacts on the baseline (e.g., as reflected in the regulatory status of 
the species, population size and growth rate where known, ongoing 
sources of human-caused mortality, or ambient noise levels).
    To avoid repetition, our analysis applies to all species listed in 
Table 2 for which take could occur, given that NMFS expects the 
anticipated effects of the proposed pile driving/removal on different 
marine mammal stocks to be similar in nature. Where there are 
meaningful differences between species

[[Page 66408]]

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. Potential takes could occur if individuals are present in 
the ensonified zone when these activities are underway.
    No serious injury or mortality would be expected, even in the 
absence of required mitigation measures, given the nature of the 
activities. Further, limited take by Level A harassment is proposed for 
two species, but the potential for harassment would be minimized 
through the construction method and the implementation of the planned 
mitigation measures (see Proposed Mitigation section).
    Take by Level A harassment is proposed 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 PTS before being observed and the 
USCG shutting down pile driving activity. Any take by Level A 
harassment is expected to arise from, at most, a small degree of PTS, 
i.e., minor degradation of hearing capabilities within regions of 
hearing that align most completely with the energy produced by impact 
pile driving (i.e., the low-frequency region below 2 kHz), not severe 
hearing impairment or impairment within the ranges of greatest hearing 
sensitivity. Animals would need to be exposed to higher levels and/or 
longer duration than are expected to occur here in order to incur any 
more than a small degree of PTS.
    Further, the amount of authorized take by Level A harassment is 
very low for both marine mammal species. If hearing impairment occurs, 
it is most likely that the affected animal would lose only a few 
decibels in its hearing sensitivity. Due to the small degree 
anticipated, any PTS potential incurred would not be expected to affect 
the reproductive success or survival of any individuals, much less 
result in adverse impacts on the species or stock.
    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 
would affect the individual's long-term ability to forage and 
communicate with conspecifics, and would 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.
    The Level A harassment zones identified in Table 5 are based upon 
an animal's exposure to pile driving of up to three steel piles per 
day. Given the short duration to impact drive each pile and break 
between pile installations (to reset equipment and move piles into 
place), an animal would 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. If an 
animal was exposed to accumulated sound energy, the resulting PTS would 
likely be small (e.g., PTS onset) at lower frequencies where pile 
driving energy is concentrated, and unlikely to result in impacts to 
individual fitness, reproduction, or survival.
    The nature of the pile driving project precludes the likelihood of 
serious injury or mortality. For all species and stocks, take would 
occur within a limited, confined area (adjacent to the project site) of 
the stock's range. Level A and Level B harassment will be reduced to 
the level of least practicable adverse impact through use of mitigation 
measures described herein. Further, the amount of take proposed to be 
authorized is small when compared to stock abundance.
    Behavioral responses of marine mammals to pile driving in the 
Columbia 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 would occur for only a portion of the project's 
duration, any harassment occurring would be temporary. Additionally, 
many of the species present in region would only be present temporarily 
based on seasonal patterns or during transit between other habitats. 
These temporarily present species would be exposed to even smaller 
periods of noise-generating activity, further decreasing the impacts.
    For all species, there are no known BIA near the project area that 
would be impacted by USCG's planned activities. While California sea 
lions and harbor seals are the species most likely to occur within the 
immediate project area the nearest haul out for both species is 
approximately 3 miles (4.8 km) away. There are three known haul out 
sites for both species near the project area including Tongue Point 
Sands, Taylor Sands, and Green Island/Sanborn Slough, the closest being 
Tongue Point Sands 3 miles (4.8 km) from the project area. 
Additionally, there is a Steller sea lion haul out in the Columbia 
River; it is approximately 15 miles (24.1 km) away from the project 
site at the south jetty off the western shoreline of Fort Stevens State 
Park. None of these haul outs are in the immediate project vicinity.
    In addition, it is unlikely that minor noise effects in a small, 
localized area of habitat would have any effect on each stock's 
continued 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 will therefore not result in population-level impacts.
    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:
     No serious injury or mortality is anticipated or proposed 
to be authorized;
     Authorized Level A harassment would be very small amounts 
and of low degree;
     For all species, the mouth of the Columbia River is a very 
small and peripheral part of their range;
     The intensity of anticipated takes by Level B harassment 
is relatively low for all stocks. Level B harassment would 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 relatively brief amounts of time in relatively 
confined footprints of the activities;
     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

[[Page 66409]]

expected to result in significant or long-term consequences for 
individuals, or to accrue to adverse impacts on their populations;
     The ensonified areas are very small relative to the 
overall habitat ranges of all species and stocks;
     The lack of anticipated significant or long-term negative 
effects to marine mammal habitat; and
     USCG would implement mitigation measures including soft 
starts and shutdown zones to minimize the numbers of marine mammals 
exposed to injurious levels of sound, and to ensure that take by Level 
A harassment is, at most, a small degree of PTS.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from the proposed 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 
proposed take is below one third of the population for all marine 
mammal stocks (Table 10).
    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 Endangered Species Act of 1973 (ESA; 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally whenever we propose to authorize take for 
endangered or threatened species.
    No incidental take of ESA-listed species is proposed for 
authorization or expected to result from this activity. Therefore, NMFS 
has determined that formal consultation under section 7 of the ESA is 
not required for this action.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to the USCG for conducting impact pile driving associated 
with the ETP project in Astoria, Oregon, provided the previously 
mentioned mitigation, monitoring, and reporting requirements are 
incorporated. A draft of the proposed IHA can be found at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this notice of proposed IHA for the proposed 
construction project. We also request comment on the potential renewal 
of this proposed IHA as described in the paragraph below. Please 
include with your comments any supporting data or literature citations 
to help inform decisions on the request for this IHA or a subsequent 
renewal IHA.
    On a case-by-case basis, NMFS may issue a one-time, 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:
     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).
     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.
    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: September 18, 2023.
Catherine Marzin,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2023-20534 Filed 9-26-23; 8:45 am]
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