[Federal Register Volume 89, Number 111 (Friday, June 7, 2024)]
[Notices]
[Pages 48579-48597]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-12473]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XD940]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Log Export Dock Project on the 
Columbia River Near Longview, WA

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 Weyerhaeuser Company 
(Weyerhaeuser) for authorization to take marine mammals incidental to 
Log Export Dock Project on the Columbia River near Longview, 
Washington. 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 the 
Request for Public Comments section at the end of this notice. NMFS 
will consider public comments prior to making any final decision on the 
issuance of the requested MMPA authorization and agency responses will 
be summarized in the final notice of our decision.

DATES: Comments and information must be received no later than July 8, 
2024.

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

[[Page 48580]]

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/permit/incidental-take-authorizations-under-marine-mammal-protection-act 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: Rachel Wachtendonk, Office of 
Protected Resources (OPR), NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are proposed or, if the taking is limited to harassment, a notice of a 
proposed IHA is provided to the public for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of the species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the monitoring and 
reporting of the takings. The definitions of all applicable MMPA 
statutory terms cited above are included in the relevant sections 
below.

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 October 29, 2023, NMFS received a request from Weyerhaeuser for 
an IHA to take marine mammals incidental to pile driving and removal 
activities associated with the Log Export Dock Project on the Columbia 
River near Longview, Washington. Following NMFS' review of the 
application, Weyerhaeuser submitted a revised version on March 14, 
2024. The application was deemed adequate and complete on April 16, 
2024. Weyerhaeuser's request is for take of harbor seal (Phoca 
vitulina), California sea lion (Zalophus californiaus), and Steller sea 
lion (Eumatopius jubatus) by Level B harassment and, for harbor seals 
by Level A harassment. Neither Weyerhaeuser nor NMFS expect serious 
injury or mortality to result from this activity and, therefore, an IHA 
is appropriate.

Description of Proposed Activity

Overview

    Weyerhaeuser is proposing the partial demolition and replacement of 
the existing Log Export dock on the Columbia River, near Longview, 
Washington (figure 1). The existing dock is a timber structure that was 
constructed in the early 1970s and has exceeded its designated 
lifespan. Over the past decade, individual timber piles have been 
replaced with steel piles but continued deterioration has led 
Weyerhaeuser to pursue a reconstruction design that will replace all of 
the timber elements with steel and concrete. For the dock to remain in 
operation during construction, only half of the dock would be 
demolished and replaced under this authorization. The reconstruction 
work of the other half of the dock will be under a separate future 
authorization. The proposed project includes impact and vibratory pile 
installation and vibratory pile removal.
    Sounds resulting from pile driving and removal may result in the 
incidental take of marine mammals by Levels A and B harassment in the 
form of auditory injury or behavioral harassment. Underwater sound 
would be constrained to the Columbia River and would be truncated by 
land masses in the river. Construction activities would start in 
September 2025 and last 5 months.

Dates and Duration

    The proposed IHA would be effective from September 1, 2025, through 
August 31, 2026. Vibratory and impact pile driving and auger drilling 
are expected to start in September 2025 and take about 120 days of in-
water work within the U.S. Army Corps of Engineers (USACE) and the U.S. 
Fish and Wildlife Service (USFWS)-designated in-water work window 
(September 1, 2025-January 3, 2026). All pile installation will occur 
during the work window, which would minimize potential exposure of 
Endangered Species Act (ESA) listed fish species from impact pile 
driving. An additional 30 days of vibratory pile removal may occur 
outside the window. All pile driving and removal would be completed 
during daylight hours.

Specific Geographic Region

    The project is located at the Weyerhaeuser marine terminal, near 
Longview, Washington, at river mile (RM) 66 of the Columbia River. 
Project activities would occur within the existing dock's current 
footprint.

[[Page 48581]]

[GRAPHIC] [TIFF OMITTED] TN07JN24.000

Detailed Description of the Specified Activity
    The demolition and replacement of the 612-foot (ft), or 186.5-meter 
(m) berth A of the Log Export Dock would include the removal of 983 16-
inch (in), or 0.41-m, timber piles, 36 16-in (0.41-m) steel pipe piles, 
10 12-in (0.30-m) steel H-piles, 7 12-in (0.30-m) steel pipe piles, and 
20 14- or 16-in (0.36- or 0.41-m) steel fender piles. Existing piles 
would be primarily removed by the deadpull method, with piles being 
removed with the vibratory hammer if the deadpull is unsuccessful. 
Broken or damaged piles would be cut at the mudline. It is anticipated 
that 75 percent of the existing 983 timber piles will be removed by the 
deadpull method, with the remaining 246 being removed with the 
vibratory hammer. The new structure will be supported by the 
installation of 325 30-in (0.76-m) steel pipe piles. In addition, up to 
26 24-in (0.61 m) temporary steel pipe piles may be installed and 
removed to support permanent pile installation. Temporary and permanent 
piles would be initially installed with a vibratory hammer, with 
permanent piles being followed by an impact hammer to embed them to 
their final depth. To reduce underwater noise produced by impact pile 
driving, an unconfined bubble curtain will be used during impact pile 
installation. Table 1 provides a summary of the pile driving 
activities.
    Concurrent Activities--In order to maintain project schedules, it 
is possible that multiple pieces of equipment would operate at the same 
time within the project area. Piles may be driven on the same day or, 
less commonly, at the same time, by two impact hammers, one impact 
hammer and one vibratory hammer, or two vibratory hammers. The method 
of installation, and whether concurrent pile driving scenarios will be 
implemented, will be determined by the construction crew once the 
project has begun. Therefore, the total take estimate reflects the 
worst-case scenario (both hammers installing 30-in steel pipe piles) 
for the proposed project. However, the most likely scenario is the 
vibratory removal of a 16-in timber pile at the same time as installing 
a 30-in steel pipe piles by vibratory or impact methods.

                          Table 1--Number and Type of Piles To Be Installed and Removed
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                                                             Number of                            Piles    Total
              Activity                 Pile type and size      piles            Method           per day   days
----------------------------------------------------------------------------------------------------------------
Demolition.........................  16-in timber pile.....        246  Vibratory.............         8      30
                                     12-in steel pipe pile.          7                                 8      60
                                     12-in steel H-pile....         10                                 8      60
                                     16-in steel pipe pile.         36                                 8      60
                                     14- or 16-in steel             20                                 8      60
                                      fender pile.
                                     24-in temporary steel          26                                 8     120
                                      pipe pile.

[[Page 48582]]

 
Installation.......................  24-in temporary steel          26  Vibratory.............         8     120
                                      pipe pile.
                                     30-in steel pipe pile.        325  Vibratory.............         8     120
                                                                        Impact................         8     120
----------------------------------------------------------------------------------------------------------------

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

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 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. 2022 SARs. All values presented in table 2 are the most 
recent available at the time of publication (including from the draft 
2023 SARs) and are available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

                                     Table 2--Marine Mammal Species \1\ 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/
                                                                                                \2\          abundance survey) \3\               SI \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and
 sea lions):
    California Sea Lion.............  Zalophus californianus.  U.S....................  -, -, N             257,606 (N/A, 233,515,     14,011       >321
                                                                                                             2014).
    Steller Sea Lion................  Eumetopias jubatus.....  Eastern................  -, -, N             36,308 (N/A, 36,308,        2,178       93.2
                                                                                                             2022) \5\.
Family Phocidae (earless seals):
    Harbor Seal.....................  Phoca vitulina.........  OR/WA Coastal..........  -, -, N             UNK (UNK, UNK, 1999)..        UND       10.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
  (https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies; Committee on Taxonomy, 2022).
\2\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
  designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or
  which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
  automatically designated under the MMPA as depleted and as a strategic stock.
\3\ NMFS marine mammal SARs online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region.
  CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.
\5\ Nest is best estimate of counts, which have not been corrected for animals at sea during abundance surveys. Estimates provided are for the U.S.
  only.

    As indicated above, all three species (with three managed stocks) 
in table 2 temporally and spatially co-occur with the activity to the 
degree that take is reasonably likely to occur.

California Sea Lion

    California sea lions are the most frequently sighted sea lion found 
in Washington waters and use haulout sites along the outer coast, the 
Strait of Juan de Fuca, and in the Puget Sound. California sea lions 
have been observed in increasing numbers farther and farther up the 
Columbia River since the 1980s, first to the Astoria area, and then to 
the Cowlitz River and Bonneville Dam (Washington Department of Fish and 
Wildlife (WDFW), 2020). However, the number of California sea lions 
observed at Bonneville Dam has been in decline, ranging from 149 
individuals in 2016 to 24 individuals in 2021, including no 
observations of California sea lions during fall and winter of 2019 to 
2020 (van der Leeuw and Tidwell, 2022).

[[Page 48583]]

    In recent years, California sea lions have been reported below 
Bonneville Dam feeding on returning adult salmon. California sea lions 
have been observed hauling out on shoals and log booms in Carroll 
Slough near the confluence of the Cowlitz and Columbia rivers during 
winter and spring months, (Jeffries et al., 2000) about 2.2 miles (mi), 
or 3.5 kilometers (km), upstream of the project site.

Steller Sea Lion

    Steller sea lions that occur in the Lower Columbia River, including 
the project vicinity, are members of the eastern Distinct Population 
Segment (DPS), ranging from Southeast Alaska to central California, 
including Washington (Jeffries et al., 2000; Scordino, 2006; NMFS, 
2013). In Washington, Steller sea lions occur mainly along the outer 
coast from the Columbia River to Cape Flattery (Jeffries et al., 2000). 
Smaller numbers use the Strait of Juan de Fuca, San Juan Islands, and 
Puget Sound south to about the Nisqually River mouth in Thurston and 
Pierce counties (Wiles, 2015). The eastern DPS of Steller sea lions has 
historically bred on rookeries located in Southeast Alaska, British 
Columbia, Oregon, and California. However, within the last several 
years, a new rookery has become established on the outer Washington 
coast at the Carroll Island and Sea Lion Rock complex (Muto et al., 
2019).
    Similar to California sea lions, Steller sea lions have also been 
observed at the base of Bonneville Dam in recent years, feeding on 
white sturgeon (Acipenser transmontanus) and salmonids (WDFW, 2020). 
However, Steller sea lions were not observed entering the Columbia 
River in significant numbers until the 1980s and they were not observed 
at the dam until after 2003.

Harbor Seal

    Harbor seals are the most common, widely distributed marine mammal 
found in Washington marine waters and are frequently observed in the 
nearshore marine environment. The Oregon/Washington Coastal Stock was 
most recently estimated at 24,732 harbor seals in 1999 and more recent 
abundance data is not available and no current estimate of abundance 
for this stock (Carretta et al., 2022). Harbor seals use hundreds of 
sites to rest or haul out along coastal and inland waters, including 
intertidal sand bars and mudflats in estuaries; intertidal rocks and 
reefs; sandy, cobble, and rocky beaches; islands; and log booms, docks, 
and floats in all marine areas of the state (Jeffries et al., 2003).
    Harbor seals in this population are typically non-migratory and 
reside year-round in the Columbia River, and generally remain in the 
same area throughout the year for breeding and feeding. Pupping seasons 
in coastal estuaries vary geographically; in the Columbia River, 
Willapa Bay, and Grays Harbor, pups are born from mid-April through 
June (Jeffries et al., 2003). Harbor seals in the Columbia River do 
exhibit some seasonal movement upriver, including into or through the 
project area of ensonification, to follow winter and spring runs of 
Pacific eulachon (Thaleichthys pacificus) and outmigrating juvenile 
salmon (Oncorhynchus spp.), and they are observed regularly in portions 
of the Columbia River including the action area. Within the lower 
Columbia River, they tend to congregate to feed at the mouths of 
tributary rivers, including the Cowlitz and Kalama rivers (RMs 68 and 
73, respectively). WDFW's atlas of seal and sea lion haulout sites 
(Jeffries et al., 2000) identifies shoals near the confluence of the 
Cowlitz and Columbia rivers located approximately 2.4 mi (3.9 km) 
upstream of the project site as a documented haulout for harbor seals.

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]
------------------------------------------------------------------------
                                      Generalized hearing range in hertz
           Hearing group                  (Hz) and kilohertz (kHz) *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans         7 Hz to 35 kHz.
 (baleen 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 spp., river
 dolphins, Cephalorhynchids,
 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 the ~65-dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth et al., 
2013). This

[[Page 48584]]

division between phocid and otariid pinnipeds is now reflected in the 
updated hearing groups proposed in Southall et al. (2019).
    For more detail concerning these groups and associated frequency 
ranges, 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.

Description of Sound Sources

    The marine soundscape is comprised of both ambient and 
anthropogenic sounds. Ambient sound is defined as the all-encompassing 
sound in a given place and is usually a composite of sound from many 
sources both near and far. 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 to 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 (American 
National Standards Institute (ANSI), 1986; National Institute for 
Occupational Safety and Health (NIOSH), 1998; ANSI, 2005; NMFS, 2018). 
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, 2018). The distinction between these two sound 
types is important because they have differing potential to cause 
physical effects, particularly with regard to hearing (e.g., Ward, 1997 
in Southall et al., 2007).
    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). 
Vibratory hammers install piles by vibrating them and allowing the 
weight of the hammer to push them into the sediment. The vibrations 
produced also cause liquefaction of the substrate surrounding the pile, 
enabling the pile to be extracted or driven into the ground more 
easily. Vibratory hammers produce significantly less sound than impact 
hammers. 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 Weyerhaeuser'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 the 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 installation and removal, and sediment removal during auger 
drilling.

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 proposed 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 an auditory threshold shift (TS) and 
behavioral reactions (e.g., avoidance, temporary cessation of foraging 
and vocalizing, changes in dive behavior). Exposure to anthropogenic 
noise can also lead to non-observable physiological responses, such as 
an increase in stress hormones. Additional noise in a marine mammal's 
habitat can mask acoustic cues used by marine mammals to carry out 
daily functions such as communication and predator and prey detection. 
The effects of pile driving 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 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. A 
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

[[Page 48585]]

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 
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 TS 
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 (Southall et al., 2007, 2019), a TTS of 6 dB is considered 
the minimum TS clearly larger than any day-to-day or session-to-session 
variation in a subject's normal hearing ability (Schlundt et al., 2000; 
Finneran et al., 2000, 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 auditory 
masking, below). For example, a marine mammal may be able to readily 
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal 
is traveling through the open ocean, where ambient noise is lower and 
there are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during 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). 
TTS is the mildest form of hearing impairment that can occur during 
exposure to sound (Kryter, 2013). While experiencing TTS, the hearing 
threshold rises, and a sound must be at a higher level in order to be 
heard. In terrestrial and marine mammals, TTS can last from minutes or 
hours to days (in cases of strong TTS). In many cases, hearing 
sensitivity recovers rapidly after exposure to the sound ends. For 
pinnipeds in water, measurements of TTS are limited to harbor seals, 
elephant seals (Mirounga angustirostris), bearded seals (Erignathus 
barbatus) and California sea lions (Zalophus californianus) (Kastak et 
al., 1999, 2007; Kastelein et al., 2019b, 2019c, 2021, 2022a, 2022b; 
Reichmuth et al., 2019; Sills et al., 2020). These studies examined 
hearing thresholds measured in marine mammals before and after exposure 
to intense or long-duration sound exposures. The difference between the 
pre-exposure and post-exposure thresholds can be used to determine the 
amount of TS 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 
for a species or hearing group, 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, 2019c). Note that in general, harbor 
seals have a lower TTS onset than other measured pinniped species 
(Finneran, 2015). In addition, TTS can accumulate across multiple 
exposures, but the resulting TTS will be less than the TTS from a 
single, continuous exposure with the same SEL (Mooney et al., 2009; 
Finneran et al., 2010; Kastelein et al., 2014, 2015). This means that 
TTS predictions based on the total, SELcum will overestimate 
the amount of TTS from intermittent exposures, such as sonars and 
impulsive sources. Nachtigall et al. (2018) describe 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. Additionally, the existing marine mammal TTS data come 
from a limited number of individuals within these species.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals, but such relationships are assumed to be similar to 
those in humans and other terrestrial mammals. PTS typically occurs at 
exposure levels at least several dBs above that inducing mild TTS 
(e.g., a 40-dB TS approximates PTS onset (Kryter et al., 1966; Miller, 
1974), while a 6-dB TS approximates TTS onset (Southall et al., 2007, 
2019). Based on data from terrestrial mammals, a precautionary 
assumption is that the PTS thresholds for impulsive sounds (such as 
impact pile driving pulses as received close to the source) are at 
least 6 dB higher than the TTS threshold on a peak-pressure basis and 
PTS cumulative sound exposure level thresholds are 15 to 20 dB higher 
than TTS cumulative sound exposure level thresholds (Southall et al., 
2007, 2019). Given the higher level of sound or longer exposure 
duration necessary to cause PTS as compared with TTS, it is 
considerably less likely that PTS could occur.
    Installing piles for this project requires either impact pile 
driving or

[[Page 48586]]

vibratory pile driving. For this project, these activities could occur 
at the same time, and there would be pauses in activities producing the 
sound during each day. Given these pauses, and that many marine mammals 
are likely moving through the ensonified area and not remaining for 
extended periods of time, the potential for TS declines.
    Behavioral Harassment--Exposure to noise from pile driving and 
removal also has the potential to behaviorally disturb marine mammals. 
Available studies show wide variation in response to underwater sound; 
therefore, it is difficult to predict specifically how any given sound 
in a particular instance might affect marine mammals perceiving the 
signal. If a marine mammal does react briefly to an underwater sound by 
changing its behavior or moving a small distance, the impacts of the 
change are unlikely to be significant to the individual, let alone the 
stock or population. However, if a sound source displaces marine 
mammals from an important feeding or breeding area for a prolonged 
period, impacts on individuals and populations could be significant 
(e.g., Lusseau and Bejder, 2007; Weilgart, 2007; National Research 
Council (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); or 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 
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

[[Page 48587]]

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 on manmade objects, we believe that incidents of take 
resulting solely from airborne sound are unlikely because there are no 
known haulouts within the project vicinity on the Columbia River. The 
closest haulout site for California sea lions and harbor seals is 2.2 
mi upstream of the project site in Carroll Slough near the confluence 
of the Cowlitz and Columbia rivers. Steller sea lions do not have any 
known haulouts near the project area. 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.

Marine Mammal Habitat Effects

    Weyerhaeuser's construction activities could have localized, 
temporary impacts on marine mammal habitat by increasing in-water SPLs 
and slightly decreasing water quality. No net habitat loss is expected, 
as the dock will be reconstructed within its original footprint. 
Construction activities are localized and would likely have temporary 
impacts on marine mammal habitat through increases in underwater 
sounds. 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 pile 
driving activities, elevated levels of underwater noise would ensonify 
the project area where both fishes and marine mammals may occur and 
could affect foraging success. Additionally, marine mammals may avoid 
the area during construction; however, displacement due to noise is 
expected to be temporary and is not expected to result in long-term 
effects to the individuals or populations.
    Temporary and localized reduction in water quality would occur 
because of in-water construction activities as well. Most of this 
effect would occur during the installation and removal of piles when 
bottom sediments are disturbed. The installation of piles would disturb 
bottom sediments and may cause a temporary increase in suspended 
sediment in the project area. In general, turbidity associated with 
pile installation is localized to about 25-ft (7.6-m) radius around the 
pile (Everitt et al., 1980). Pinnipeds are not expected to be close 
enough to the pile driving areas to experience effects of turbidity, 
and could avoid localized areas of turbidity. Therefore, we expect the 
impact from increased turbidity levels to be discountable to marine 
mammals and do not discuss it further.

In-Water Construction Effects on Potential Foraging Habitat

    The proposed activities would not result in permanent impacts to 
habitats used directly by marine mammals outside of the actual 
footprint of the reconstructed dock. The total riverbed area affected 
by pile installation and removal is a very small area compared to the 
vast foraging area available to marine mammals in the Columbia River 
and Washington's outer coast. Pile extraction and installation may have 
impacts on benthic invertebrate species primarily associated with 
disturbance of sediments that may cover or displace some invertebrates. 
The impacts would be temporary and highly localized, and no habitat 
would be permanently displaced by construction. Therefore, it is 
expected that impacts on foraging opportunities for marine mammals due 
to the demolition and reconstruction of the dock would be minimal.
    It is possible that avoidance by potential prey (i.e., fish) in the 
immediate area may occur due to temporary loss of this foraging 
habitat. The duration of fish avoidance of this area after pile driving 
stops is unknown, but we anticipate a rapid return to normal 
recruitment, distribution and behavior. Any behavioral avoidance by 
fish of the disturbed area would still leave large areas of fish and 
marine mammal foraging habitat in the nearby vicinity in the in the 
project area and Columbia River.

Effects on Potential Prey

    Sound may affect marine mammals through impacts on the abundance, 
behavior, or distribution of prey species (e.g., fish). Marine mammal 
prey varies by species, season, and location. Here, we describe studies 
regarding the effects of noise on known marine mammal prey.
    Fish utilize the soundscape and components of sound in their 
environment to perform important functions such as foraging, predator 
avoidance, mating, and spawning (e.g., Zelick et al., 1999; Fay, 2009). 
Depending on their hearing anatomy and peripheral sensory structures, 
which vary among species, fishes hear sounds using pressure and 
particle motion sensitivity capabilities and detect the motion of 
surrounding water (Fay et al., 2008). The potential effects of noise on 
fishes depends on the overlapping frequency range, distance from the 
sound source, water depth of exposure, and species-specific hearing 
sensitivity, anatomy, and physiology. Key impacts to fishes may include 
behavioral responses, hearing damage, barotrauma (pressure-related 
injuries), and mortality.
    Fish react to sounds which are especially strong and/or 
intermittent low-frequency sounds, and behavioral responses, such as 
flight or avoidance are the most likely effects. Short duration, sharp 
sounds can cause overt or subtle changes in fish behavior and local 
distribution. The reaction of fish to noise depends on the 
physiological state of the fish, past exposures, motivation (e.g., 
feeding, spawning, migration), and other environmental factors. 
Hastings and Popper (2005) identified several studies that suggest fish 
may relocate to avoid certain areas of sound energy. Additional studies 
have documented effects of pile driving on fish, 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; Cott 
et al., 2012).

[[Page 48588]]

    SPLs of sufficient strength have been known to cause injury to 
fishes and fish mortality (summarized in Popper et al., 2014). However, 
in most fish species, hair cells in the ear continuously regenerate and 
loss of auditory function likely is restored when damaged cells are 
replaced with new cells. Halvorsen et al. (2012b) showed that a TTS of 
4 to 6 dB was recoverable within 24 hours for one species. Impacts 
would be most severe when the individual fish is close to the source 
and when the duration of exposure is long. Injury caused by barotrauma 
can range from slight to severe and can cause death, and is most likely 
for fish with swim bladders. Barotrauma injuries have been documented 
during controlled exposure to impact pile driving (Halvorsen et al., 
2012a; Casper et al., 2013, 2017).
    Fish populations in the proposed project area that serve as marine 
mammal prey could be temporarily affected by noise from pile 
installation and removal. The frequency range in which fishes generally 
perceive underwater sounds is 50 to 2,000 Hz, with peak sensitivities 
below 800 Hz (Popper and Hastings, 2009). Fish behavior or distribution 
may change, especially with strong and/or intermittent sounds that 
could harm fishes. High underwater SPLs have been documented to alter 
behavior, cause hearing loss, and injure or kill individual fish by 
causing serious internal injury (Hastings and Popper, 2005).
    The greatest potential impact to fishes during construction would 
occur during impact pile driving. However, the duration of impact pile 
driving would be limited to the final stage of installation 
(``proofing'') after the pile has been driven as close as practicable 
to the design depth with a vibratory driver. In-water construction 
activities would only occur during daylight hours, allowing fish to 
forage and transit the project area in the evening. Vibratory pile 
driving could elicit behavioral reactions from fishes such as temporary 
avoidance of the area but is unlikely to cause injuries to fishes or 
have persistent effects on local fish populations. Additionally, all 
pile installation would occur only during a USACE and USFWS-designated 
in-water work window to minimize potential exposure of ESA-listed fish 
species migrating through the project site to noise from impact pile 
driving. Vibratory and deadpull removal of piles could occur at any 
time during the authorization period. Construction also would have 
minimal permanent and temporary impacts on benthic invertebrate 
species, a marine mammal prey source.
    The area impacted by the project is relatively small compared to 
the available habitat in the remainder of the Columbia River, and there 
are no areas of particular importance that would be impacted by this 
project. 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. As described in the preceding, 
the potential for Weyerhaeuser's construction to affect the 
availability of prey to marine mammals or to meaningfully impact the 
quality of physical or acoustic habitat is considered to be 
insignificant.

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
proposed for authorization through the IHA, which will inform NMFS' 
consideration of ``small numbers,'' the negligible impact 
determinations, and impacts on subsistence uses.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes would primarily be by Level B harassment, as use 
of the acoustic source (i.e., pile driving) has the potential to result 
in disruption of behavioral patterns for individual marine mammals. 
There is also some potential for auditory injury (Level A harassment) 
to result, primarily for phocids because predicted auditory injury 
zones are larger than for otariids. Auditory injury is unlikely to 
occur for otariids. 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.

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. Generally speaking, Level B harassment take 
estimates based on these behavioral harassment thresholds are expected 
to include any

[[Page 48589]]

likely takes by TTS as, in most cases, the likelihood of TTS occurs at 
distances from the source less than those at which behavioral 
harassment is likely. TTS of a sufficient degree can manifest as 
behavioral harassment, as reduced hearing sensitivity and the potential 
reduced opportunities to detect important signals (conspecific 
communication, predators, prey) may result in changes in behavior 
patterns that would not otherwise occur.
    Weyerhaeuser's proposed activity includes the use of continuous 
(vibratory pile driving) and impulsive (impact pile driving) sources, 
and therefore the RMS SPL thresholds of 120 and 160 dB re 1 [mu]Pa are 
applicable.
    Level A Harassment--NMFS' 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). 
Weyerhaeuser's proposed activity includes the use of impulsive (impact 
pile driving) and non-impulsive (vibratory pile driving) sources.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS' 2018 Technical Guidance, which may be accessed at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

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

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that are used in estimating the area ensonified above the 
acoustic thresholds, including source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the proposed project. 
Pile driving generates underwater noise that can potentially result in 
disturbance to marine mammals in the project area. The maximum 
(underwater) area ensonified is determined by the topography of the 
Columbia River, including intersecting land masses that will reduce the 
overall area of potential impact. Additionally, vessel traffic, 
including the other half of the dock (berth B) remaining operational 
during construction, in the project area may contribute to elevated 
background noise levels, which may mask sounds produced by the project.
    Transmission loss (TL) is the decrease in acoustic intensity as an 
acoustic pressure wave propagates out from a source. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. The general formula for underwater TL is:

TL = B x Log10 (R1/R2),

where

TL = transmission loss in dB;
B = transmission loss coefficient; for practical spreading equals 
15;
R1 = the distance of the modeled SPL from the driven 
pile; and,
R2 = the distance from the driven pile of the initial 
measurement.

    This formula neglects loss due to scattering and absorption, which 
is assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions including in-water structures and 
sediments. Spherical spreading occurs in a perfectly unobstructed 
(free-field) environment not limited by depth or water surface, 
resulting in a 6-dB reduction in sound level for each doubling of 
distance from the source (20 x log10[range]). Cylindrical 
spreading occurs in an environment in which sound propagation is 
bounded by the water surface and sea bottom, resulting in a reduction 
of 3 dB in sound level for each doubling of distance from the source 
(10 x log10[range]). A practical spreading value of 15 is 
often used under conditions, such as the project site, where water 
increases with depth as the receiver moves away from the shoreline, 
resulting in an expected propagation environment that would lie between 
spherical and cylindrical spreading loss conditions. Practical 
spreading loss is assumed here.
    The intensity of pile driving sounds is greatly influenced by 
factors such as the type of piles, hammers, and the physical 
environment in which the activity takes place. In order to calculate 
the distances to the Level A harassment and the Level B harassment 
sound thresholds for the methods and piles being used in this project, 
NMFS used acoustic monitoring data from other locations to develop 
proxy source levels for the various pile types, sizes and methods 
(table 5). Generally, we choose source levels from similar pile types 
from locations (e.g., geology, bathymetry) similar to the project.

[[Page 48590]]



                      Table 5--Proxy Sound Source Levels for Pile Sizes and Driving Methods
----------------------------------------------------------------------------------------------------------------
                                     Peak SPL
        Pile type and size            (re 1     RMS SPL (re     SEL (re 1                   Source
                                     [mu]Pa)     1 [mu]Pa)     [mu]Pa\2\-s)
----------------------------------------------------------------------------------------------------------------
                                     Vibratory pile installation and removal
----------------------------------------------------------------------------------------------------------------
16-in timber pile................  ...........          162  ...............  Caltrans, 2020.
12-in steel pipe.................  ...........          158  ...............  Laughlin, 2012.
12-in steel H-pile...............  ...........          152  ...............  Laughlin, 2019.
16-in steel pipe \1\.............  ...........          161  ...............  Navy, 2015.
24-in temporary steel pipe.......  ...........          161  ...............  Navy, 2015.
30-in steel pipe.................  ...........          163  ...............  Anchor, QEA, 2021; Greenbush,
                                                                               2019, as cited by NMFS in 87 FR
                                                                               31985; Denes et al., 2016, table
                                                                               72.
----------------------------------------------------------------------------------------------------------------
                                            Impact pile installation
----------------------------------------------------------------------------------------------------------------
30-in steel pipe \2\.............          210          190              177  Caltrans, 2020; Cara Hotchkin,
                                                                               NMFS personal communication, 1/18/
                                                                               2024.
----------------------------------------------------------------------------------------------------------------
\1\ For the purposes of this analysis, the underwater sound source level for removal of existing 16-in steel
  piles (i.e., 161 dB RMS per Navy, 2015) has been used for the removal of approximately 36 16-in steel pipe
  piles and 20 fender piles (14- or 16-in steel pipe piles).
\2\ Using an unconfined bubble curtain.

    For this project, two hammers, including any combination of 
vibratory and impact hammers, may operate simultaneously. As noted 
earlier, the estimated ensonfied area reflects the worst-case scenario 
(both hammers installing 30-in steel pipe piles) for the proposed 
project. However, the most likely scenario is the removal of a 16-in 
timber pile at the same time as installing a 30-in steel pipe pile. The 
calculated proxy source levels for the different potential concurrent 
pile driving scenarios are shown in table 6.
Two Impact Hammers
    For simultaneous impact driving of two 30-in steel pipe piles (the 
most conservative scenario), the number of strikes per pile was doubled 
to estimate total sound exposure during simultaneous installation. 
While the likelihood of impact pile driving strikes completely 
overlapping in time is rare due to the intermittent nature and short 
duration of strikes, NMFS conservatively estimates that up to 20 
percent of strikes may overlap completely in time. Therefore, to 
calculate Level B isopleths for simultaneous impact pile driving, dB 
addition (if the difference between the two sound source levels is 
between 0 and 1 dB, 3 dB are added to the higher sound source level) 
was used to calculate the combined sound source level of 193 dB RMS 
that was used in this analysis.
One Impact Hammer, One Vibratory Hammer
    To calculate Level B isopleths for one impact and one vibratory 
hammer operating simultaneously, sources were treated as though they 
were non-overlapping and the isopleth associated with the individual 
source which results in the largest Level B harassment isopleth was 
conservatively used for both sources to account for periods of 
overlapping activities.
Two Vibratory Hammers
    To calculate Level B isopleths for two simultaneous vibratory 
hammers, the NMFS acoustic threshold calculator was used with modified 
inputs to account for accumulation, weighting, and source overlap in 
space and time. Using the rules of dB addition if the difference 
between the two sound source levels is between 0 and 1 dB, 3 dB are 
added to the higher sound source level), the combined sound source 
level for the simultaneous vibratory installation of two 30-in steel 
piles is 166 dB RMS.
    The ensonified area associated with Level A harassment is more 
technically challenging to predict due to the need to account for a 
duration component. Therefore, NMFS developed an optional User 
Spreadsheet tool to accompany the Technical Guidance that can be used 
to relatively simply predict an isopleth distance for use in 
conjunction with marine mammal density or occurrence to help predict 
potential takes. We note that because of some of the assumptions 
included in the methods underlying this optional tool, we anticipate 
that the resulting isopleth estimates are typically going to be 
overestimates of some degree, which may result in an overestimate of 
potential take by Level A harassment. However, this optional tool 
offers the best way to estimate isopleth distances when more 
sophisticated modeling methods are not available or practical. For 
stationary sources, like pile driving, the optional User Spreadsheet 
tool predicts the distance at which, if a marine mammal remained at 
that distance for the duration of the activity, it would be expected to 
incur PTS. Inputs used in the optional User Spreadsheet tool, and the 
resulting estimated isopleths, are reported in table 7, below.
    To calculate Level A isopleths for two impact hammers operating 
simultaneously, the NMFS User Spreadsheet calculator was used with 
modified inputs to account for the total estimated number of strikes 
for all piles. For simultaneous impact driving of two 30-in steel pipe 
piles (the most conservative scenario), the number of strikes per pile 
was doubled to estimate total sound exposure during simultaneous 
installation, and the number of piles per day was reduced to one. The 
source level for two simultaneous impact hammers was not adjusted 
because for identical sources the accumulation of energy depends only 
on the total number of strikes, whether or not they overlap fully in 
time. Therefore, the source level used for two simultaneous impact 
hammers was 177 dB SELss.
    To calculate Level A isopleths of one impact hammer and one 
vibratory hammer operating simultaneously, sources were treated as 
though they were non-overlapping and the isopleth associated with the 
individual source which resulted in the largest Level A isopleth was 
conservatively used for both sources to account for periods of 
overlapping activities.
    To calculate Level A isopleths of two vibratory hammers operating 
simultaneously, the NMFS acoustic threshold calculator was used with 
modified inputs to account for accumulation, weighting, and source 
overlap in space and time. Using the rules of dB addition (NMFS, 2024; 
if the

[[Page 48591]]

difference between the two sound source levels is between 0 and 1 dB, 3 
dB are added to the higher sound source level), the combined sound 
source level for the simultaneous vibratory installation of two 30-in 
steel piles is 166 dB RMS.

          Table 6--Calculated Proxy Sound Source Levels for Potential Concurrent Pile Driving Scenarios
----------------------------------------------------------------------------------------------------------------
                                                                                        Calculated proxy sound
                Scenario                              Pile type and proxy                    source level
----------------------------------------------------------------------------------------------------------------
Two impact hammers......................  Impact install of 30-in steel pipe pile     177 dB SEL for Level A;
                                           (177 dB SEL, 190 dB RMS) AND impact         193 dB RMS for Level B.
                                           install of 30-in steel pipe pile (177 dB
                                           SEL, 190 dB RMS).
One impact hammer, one vibratory hammer.  Impact install of 30-in steel pipe pile     177 dB SEL for Level A;
                                           (177 dB SEL, 190 dB RMS) AND vibratory      163 dB RMS for Level B.
                                           install of 30-in steel pipe pile (163 dB
                                           RMS).
Two vibratory hammers...................  Vibratory install of 30-in steel pipe pile  166 dB RMS.
                                           (163 dB RMS) AND vibratory install of 30-
                                           in steel pipe pile (163 dB RMS).
----------------------------------------------------------------------------------------------------------------


                                      Table 7--NMFS User Spreadsheet Inputs
----------------------------------------------------------------------------------------------------------------
                                                                                       Duration to
                                Spreadsheet tab   Weighting factor   Number of piles     drive a      Number of
      Pile size and type             used         adjustment (kHz)       per day       single pile   strikes per
                                                                                          (min)         pile
----------------------------------------------------------------------------------------------------------------
                                       Vibratory pile driving and removal
----------------------------------------------------------------------------------------------------------------
16-in timber pile............  A.1. Vibratory                   2.5                8            60            NA
                                pile driving.
12-in steel pipe.............  A.1. Vibratory                   2.5                8            60            NA
                                pile driving.
12-in steel H-pile...........  A.1. Vibratory                   2.5                8            60            NA
                                pile driving.
16-in steel pipe.............  A.1 Vibratory                    2.5                8            60            NA
                                pile driving.
24-in temporary steel pipe...  A.1 Vibratory                    2.5                8            60            NA
                                pile driving.
30-in steel pipe.............  A.1. Vibratory                   2.5                8            60            NA
                                pile driving.
----------------------------------------------------------------------------------------------------------------
                                               Impact pile driving
----------------------------------------------------------------------------------------------------------------
30-in steel pipe.............  E.1. Impact pile                   2                8            NA         1,000
                                driving.
----------------------------------------------------------------------------------------------------------------
                                             Concurrent pile driving
----------------------------------------------------------------------------------------------------------------
Impact install of 30-in steel  E.1. Impact pile                   2                1            NA         8,000
 pipe pile AND impact install   driving.
 of 30-in steel pipe pile.
Impact install of 30-in steel  E.1. Impact pile                   2                1            NA         8,000
 pipe pile AND vibratory        driving.
 install of 30-in steel pipe
 pile.
Vibratory install of 30-in     A.1. Vibratory                   2.5                1           480            NA
 steel pipe pile AND            pile driving.
 vibratory install of 30-in
 steel pipe pile.
----------------------------------------------------------------------------------------------------------------


                             Table 8--Calculated Levels A and B Harassment Isopleths
----------------------------------------------------------------------------------------------------------------
                                                                 Level A harassment zone (m/
                                                                           km\2\)                   Level B
                      Pile size and type                      --------------------------------  harassment zone
                                                                   Phocid          Otariid         (m/km\2\)
----------------------------------------------------------------------------------------------------------------
                                       Vibratory pile driving and removal
----------------------------------------------------------------------------------------------------------------
16-in timber pile............................................     20/0.000693      2/0.000012         6,310/8.25
----------------------------------------------------------------------------------------------------------------
12-in steel pipe.............................................     11/0.000226      1/0.000003         3,415/5.14
12-in steel H-pile...........................................      5/0.000055      1/0.000003         1,585/2.46
16-in steel pipe.............................................     17/0.000509      2/0.000012         5,412/7.47
24-in temporary steel pipe...................................
30-in steel pipe.............................................     23/0.000906      2/0.000012     7,356 \a\ \b\/
                                                                                                            8.96
----------------------------------------------------------------------------------------------------------------
                                               Impact pile driving
----------------------------------------------------------------------------------------------------------------
30-in steel pipe.............................................        852/1.16         63 \c\/         1,001/1.46
                                                                                     0.006352
----------------------------------------------------------------------------------------------------------------
                                             Concurrent pile driving
----------------------------------------------------------------------------------------------------------------
Impact install of 30-in steel pipe pile AND impact install of        852/1.16  63\c\/0.006352         1,585/2.46
 30-in steel pipe pile.......................................
Impact install of 30-in steel pipe pile AND vibratory install                                     7,356 \a\ \b\/
 of 30-in steel pipe pile....................................                                               8.96
Vibratory install of 30-in steel pipe pile AND vibratory             36/2,153      3/0.000023   11,660 \b\/10.52
 install of 30-in steel pipe pile............................
----------------------------------------------------------------------------------------------------------------
\a\ The Level B harassment thresholds for the vibratory installation of a single 30-in steel pile are equivalent
  to the potential simultaneous installation of up to two 30-inch steel piles using one impact hammer and one
  vibratory hammer operating concurrently. As noted previously, Levels A and B harassment thresholds for
  simultaneous pile driving were analyzed based on interim guidance provided by NMFS (2024) and in coordination
  with NMFS biologists (Cara Hotchkin, NMFS, personal communication, 1/18/2024 and 2/21/2024).
\b\ The Level B harassment thresholds reported above were calculated using the practical spreading loss model,
  although the extent of actual sound propagation will be limited to the areas identified in figure 6-3 due to
  the shape and configuration of the Columbia River in the vicinity.


[[Page 48592]]

Marine Mammal Occurrence and Take Estimation

    In this section, we provide information about the occurrence of 
marine mammals that 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. Daily occurrence data cones from USACE compiled 
weekly monitoring reports collected at the Bonneville Dam (RM 146) from 
2020 through 2021 (van der Leeuw and Tidwell, 2022). As pinnipeds would 
need to swim past the proposed project site to reach the dam, the 
number of animals observed at Bonneville Dam may be slightly lower than 
what would be observed at the project site. The take calculations for 
this project are:

Incidental take estimate = (number of days during work window x 
estimated number of animals per day) + (number of days outside work 
window x estimated number of animals per day).

California Sea Lion

    The numbers of California sea lions observed at Bonneville Dam have 
been in decline in recent years and ranged from 149 in 2016 to a total 
of 24 in 2021 (van der Leeuw and Tidwell, 2022). During the spring 
period from January 1 to May 6, 2020, daily counts averaged 0.9 animals 
3.3 standard deviation, with a high of seven individuals 
(Tidwell et al., 2020). During spring 2021, California sea lions were 
present from late March through late May, but in relatively low 
numbers, with most days having five or fewer present (van der Leeuw and 
Tidwell, 2022). It is difficult to estimate the number of California 
sea lions that could potentially occur in the Level B harassment zone 
during the fall in-water work window from these data, because the 
numbers at Bonneville Dam reflect a strong seasonal presence in spring. 
A conservative estimate of three California sea lions per day during 
the in-water work window and five California sea lions per day outside 
the in-water work window was used. Therefore, using the equation given 
above, the estimated number of takes by Level B harassment for 
California sea lions would be 510.
    The largest Level A harassment zone for California sea lions 
extends 63 m from the sound source (table 8) during impact pile 
driving. All construction work would be shut down prior to a California 
sea lion entering the Level A harassment zone specific to the in-water 
activity underway at the time. In consideration of the small Level A 
harassment isopleth and proposed shutdown requirements, no take by 
Level A harassment is anticipated or proposed for California sea lions.

Steller Sea Lion

    Steller sea lions have been observed in varying numbers at 
Bonneville Dam throughout much of the year, with a peak in April and 
May (Tidwell et al., 2020; van der Leeuw and Tidwell, 2022). Reports 
from a 2-year period observed daily counts of 12 to 20 Steller sea 
lions during the fall survey period (Tidwell et al., 2020, Tidwell and 
van der Leeuw, 2021), and up to 27 Steller sea lions per day in the 
spring (van der Leeuw and Tidwell, 2022). A conservative estimate of 20 
Steller sea lions per day during the in-water work window and 27 
Steller sea lions per day outside the in-water work window was used. 
Therefore, using the equation given above, the estimated number of 
takes by Level B harassment for Steller sea lions would be 3,210.
    The largest Level A harassment zone for Steller sea lions extends 
63 m from the sound source (table 8) during impact pile driving. All 
construction work would be shut down prior to a Steller sea lion 
entering the Level A harassment zone specific to the in-water activity 
underway at the time. In consideration of the small Level A harassment 
isopleth and proposed shutdown requirements, no take by Level A 
harassment is anticipated or proposed for Steller sea lions.

Harbor Seal

    Harbor seals are rarely observed at Bonneville Dam and have been 
recorded in low numbers over the past 10 years. A recent IHA issued for 
the Port of Kalama Manufacturing and Marine Export Facility (85 FR 
76527), which is located near the proposed project site (RM 72), used a 
conservative estimate based on anecdotal information of harbor seals 
residing near the mouths of the Cowlitz and Kalama Rivers and estimated 
that there could be up to 10 present on any given day of pile driving 
(NMFS, 2017; 81 FR 15064, March 21, 2016). Therefore, using the 
equation given above, the calculated estimate take by Level B 
harassment for harbor seals would be 1,500.
    The largest Level A harassment zone for harbor seals extends 852 m 
from the sound source (table 8) during impact pile driving. The Port of 
Kalama project estimated that one harbor seal per day could be present 
in the Level A harassment zone for each day of impact pile driving. 
Using the equation given above, the calculated estimated take by Level 
A harassment for harbor seals would be 120.

                                                  Table 9--Estimated Take by Levels A and B Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                        Proposed take as
                Common name                               Stock                 Stock        Level A       Level B     Total proposed   a percentage of
                                                                              abundance    harassment    harassment         take             stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion........................  U.S. Stock....................      257,606             0           510              510                0.2
Steller sea lion...........................  Eastern DPS...................       36,308             0         3,210            3,210                8.8
Harbor seal................................  OR/WA coastal stock...........       24,732           120         1,500            1,620                6.6
--------------------------------------------------------------------------------------------------------------------------------------------------------

Proposed Mitigation

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

[[Page 48593]]

implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned); and
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, and impact on 
operations.
    The mitigation measures described in the following paragraphs would 
apply to the Weyerhaeuser in-water construction activities.

Proposed Shutdown and Monitoring Zones

    Weyerhaeuser must establish shutdown zones and Level B harassment 
monitoring 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 animal (or in 
anticipation of an animal entering the defined area). Shutdown zones 
are based on the largest Level A harassment zone for each pile size/
type and driving method, and behavioral monitoring zones are meant to 
encompass Level B harassment zones for each pile size/type and driving 
method, as shown in table 10. A minimum shutdown zone of 10 m would be 
required for all in-water construction activities to avoid physical 
interaction with marine mammals. Proposed shutdown zones for each 
activity type are shown in table 10.
    Prior to pile driving, Protected Species Observers (PSOs) would 
survey the shutdown zones and surrounding areas for at least 30 minutes 
before pile driving activities start. If marine mammals are found 
within the shutdown zone, pile driving would be delayed until the 
animal has moved out of the shutdown zone, either verified by an 
observer or by waiting until 15 minutes has elapsed without a sighting. 
If a marine mammal approaches or enters the shutdown zone during pile 
driving, the activity would be halted. Pile driving may resume after 
the animal has moved out of and is moving away from the shutdown zone 
or after at least 15 minutes has passed since the last observation of 
the animal.
    All marine mammals would be monitored in the Level B harassment to 
the extent of visibility for the on-duty PSOs. If a marine mammal for 
which take is authorized enters the Level B harassment zone, in-water 
activities would continue and PSOs would document the animal's presence 
within the estimated harassment zone.
    If a species for which authorization has not been granted, or for 
which the authorized takes are met, is observed approaching or within 
the Level B harassment zone, pile driving activities would be shut down 
immediately. Activities would not resume until the animal has been 
confirmed to have left the area or 15 minutes has elapsed with no 
sighting of the animal.

                      Table 10--Proposed Shutdown and Level B Monitoring Zones by Activity
----------------------------------------------------------------------------------------------------------------
                                                                             Minimum shutdown zone
                                                                                      (m)             Harassment
                  Method                          Pile size and type      --------------------------  monitoring
                                                                              Phocid      Otariid      zone (m)
----------------------------------------------------------------------------------------------------------------
Vibratory.................................  16-in timber pile removal....           20           10        6,310
                                            12-in steel pipe pile removal           15           10        3,415
                                            12-in steel H-pile removal...           10           10        1,585
                                            16-in steel pipe removal.....           20           10        5,412
                                            24-in steel pipe pile                   20           10        5,412
                                             (temporary) installation and
                                             removal.
                                            30-in steel pipe pile                   25           10        7,356
                                             installation.
Impact....................................  30-in steel pipe pile                  200           65        1,001
                                             installation.
                                            Two impact hammers...........          200           65        1,585
Concurrent pile driving...................  One impact hammer and one              200           65        7,356
                                             vibratory hammer.
                                            Two vibratory hammers........           40           10       11,660
----------------------------------------------------------------------------------------------------------------

PSOs

    The placement of PSOs during all pile driving and removal 
activities (described in detail in the Proposed Monitoring and 
Reporting section) will ensure that the ensonified area of the Columbia 
River is visible during pile installation.

Pre- and Post-Activity Monitoring

    Monitoring must take place from 30 minutes prior to initiation of 
pile driving activities (i.e., pre-clearance monitoring) through 30 
minutes post-completion of pile driving. Prior to the start of daily 
in-water construction activity, or whenever a break in pile driving of 
30 minutes or longer occurs, PSOs would observe the shutdown and 
monitoring zones for a period of 30 minutes. The shutdown zone would be 
considered cleared when a marine mammal has not been observed within 
the zone for a 30-minute period. If a marine mammal is observed within 
the shutdown zones, pile driving activity would be delayed or halted. 
If work ceases for more than 30 minutes, the pre-activity monitoring of 
the shutdown zones would commence. A determination that the shutdown 
zone is clear must be made during a period of good visibility (i.e., 
the entire shutdown zone and surrounding waters must be visible to the 
naked eye).

Bubble Curtain

    A bubble curtain must be employed during all impact pile driving 
activities to interrupt the acoustic pressure and reduce impact on 
marine mammals. The bubble curtain must distribute air bubbles around 
100 percent of the piling circumference for the full depth of the water 
column. The lowest bubble ring must be in contact with the mudline for 
the full circumference of the ring. The weights attached to the bottom 
ring must ensure 100 percent substrate contact. No parts of the ring or 
other objects may prevent full substrate contact. Air flow to the 
bubblers must be balanced around the circumference of the pile. If 
simultaneous use of two impact hammers occurs, both piles must be 
mitigated with bubble curtains as described above.

Soft Start

    Soft-start procedures are believed to provide additional protection 
to marine mammals by providing warning and/or giving marine mammals a 
chance to

[[Page 48594]]

leave the area prior to the impact hammer operating at full capacity. 
For impact driving, an initial set of three strikes will be made by the 
hammer at reduced energy, followed by a 30-second waiting period, then 
two subsequent three-strike sets before initiating continuous driving. 
Soft start will be implemented at the start of each day's impact pile 
driving and at any time following cessation of impact pile driving for 
a period of 30 minutes or longer.
    Based on our evaluation of the applicant's proposed measures, NMFS 
has preliminarily determined that the proposed mitigation measures 
provide the means of effecting the least practicable impact on the 
affected species or stocks and their habitat, paying particular 
attention to rookeries, mating grounds, and areas of similar 
significance.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present while 
conducting the activities. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     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 
Marine Mammal Monitoring Plan and section 5 of the IHA. A Marine Mammal 
Monitoring Plan would be submitted to NMFS for approval prior to 
commencement of project activities. Marine mammal monitoring during 
pile driving and removal must be conducted by NMFS-approved PSOs in a 
manner consistent with the following:
     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 must 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
     Weyerhaeuser must submit PSO Curriculum Vitae for approval 
by NMFS prior to the onset of pile driving.
    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. Weyerhaeuser will employ up to four 
PSOs. PSO locations will provide an unobstructed view of all water 
within the shutdown zone(s), and as much of the Level A harassment and 
Level B harassment zones as possible. PSOs would be stationed along the 
shore of the Columbia River.
    Weyerhaeuser would ensure that construction supervisors and crews, 
the monitoring team, and relevant Weyerhaeuser staff are trained prior 
to the start of activities subject to the proposed IHA, so that 
responsibilities, communication procedures, monitoring protocols, and 
operational procedures are clearly understood. New personnel joining 
during the project would be trained prior to commencing work. 
Monitoring would occur for all pile driving activities during the pile 
installation work window (September 1, 2025 through January 31, 2026). 
For pile removal activities outside the work window, one PSO would be 
on site to monitor the ensonified area once every 7 calendar days, 
whether or not vibratory pile extraction occurs on that day. Monitoring 
would be conducted 30 minutes before, during, and 30 minutes after pile 
driving/removal activities. In addition, observers shall record all 
incidents of marine mammal occurrence, regardless of distance from 
activity, and shall document any behavioral reactions in concert with 
distance from piles being driven or removed. Pile driving/removal 
activities include the time to install or remove a single pile or 
series of piles, as long as the time elapsed between uses of the pile 
driving equipment is no more than 30 minutes.

Data Collection

    PSOs would use approved data forms to record the following 
information:
     Dates and times (beginning and end) of all marine mammal 
monitoring.
     PSO locations during marine mammal monitoring.
     Construction activities occurring during each daily 
observation period, including how many and what type of piles were 
driven or removed and by what method (i.e., vibratory, impact, or auger 
drilling).
     Weather parameters and water conditions.
     The number of marine mammals observed, by species, 
relative to the pile location and if pile driving or removal was 
occurring at time of sighting.

[[Page 48595]]

     Distance and bearings of each marine mammal observed to 
the pile being driven or removed.
     Description of marine mammal behavior patterns, including 
direction of travel.
     Age and sex class, if possible, of all marine mammals 
observed.
     Detailed information about implementation of any 
mitigation triggered (such as shutdowns and delays), a description of 
specific actions that ensued, and resulting behavior of the animal if 
any.

Reporting

    A draft marine mammal monitoring report would be submitted to NMFS 
within 90 days after the completion of pile driving and removal 
activities. It would 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., vibratory driving) and the total 
equipment duration for cutting for each pile.
     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: (1) name of PSO who sighted the animal(s) and PSO location 
and activity at time of sighting; (2) time of sighting; (3) 
identification of the animal(s) (e.g., genus/species, lowest possible 
taxonomic level, or unidentified), PSO confidence in identification, 
and the composition of the group if there is a mix of species; (4) 
distance and bearing of each marine mammal observed relative to the 
pile being driven for each sighting (if pile driving was occurring at 
time of sighting); (5) estimated number of animals (min/max/best 
estimate); (6) estimated number of animals by cohort (adults, 
juveniles, neonates, group composition, etc.); (7) animal's closest 
point of approach and estimated time spent within the harassment zone; 
and (8) description of any marine mammal behavioral observations (e.g., 
observed behaviors such as feeding or traveling), including an 
assessment of behavioral responses thought to have resulted from the 
activity (e.g., no response or changes in behavioral state such as 
ceasing feeding, changing direction, flushing, or breaching).
     Number of marine mammals detected within the harassment 
zones, by species.
     Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensued, and resulting changes in behavior of the 
animal(s), if any.
    If no comments are received from NMFS within 30 days, the draft 
final report would 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, Weyerhaeuser shall report 
the incident to the OPR, NMFS and to the west coast regional stranding 
network as soon as feasible. If the death or injury was clearly caused 
by the specified activity, Weyerhaeuser 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 IHA-
holder 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, the discussion of our analysis applies to 
California sea lions, Steller sea lions, and harbor seals, given that 
the anticipated effects of this activity on these different marine 
mammal stocks are expected to be similar. There is little information 
about the nature or severity of the impacts, or the size, status, or 
structure of any of these species or stocks that would lead to a 
different analysis for this activity.
    Pile driving activities have the potential to disturb or displace 
marine mammals. Specifically, the project activities may result in 
take, in the form of Level A harassment and Level B harassment from 
underwater sounds generated from pile driving and removal. Potential 
takes could occur if individuals are present in the ensonified zone 
when these activities are underway.
    The takes from Level B harassment would be due to potential 
behavioral disturbance, and TTS. Level A harassment takes would be due 
to PTS. No mortality or serious injury is anticipated given the nature 
of the activity, even in the absence of the required mitigation. The 
potential for harassment is minimized through the construction method 
and the implementation of the proposed mitigation measures (see 
Proposed Mitigation section).

[[Page 48596]]

    Take would occur within a limited, confined area (the Columbia 
River) of the stocks' ranges. Level A harassment and Level B harassment 
would be reduced to the level of least practicable adverse impact 
through use of mitigation measures described herein. Further, the 
amount of take proposed to be authorized is extremely small when 
compared to stock abundance, and the project is not anticipated to 
impact any known important habitat areas for any marine mammal species.
    Take by Level A harassment is authorized to account for the 
potential that an animal could enter and remain within the area between 
a Level A harassment zone and the shutdown zone for a duration long 
enough to be taken by Level A harassment. Any take by Level A 
harassment is expected to arise from, at most, a small degree of PTS 
because animals would need to be exposed to higher levels and/or longer 
duration than are expected to occur here in order to incur any more 
than a small degree of PTS. Additionally, and as noted previously, some 
subset of the individuals that are behaviorally harassed could also 
simultaneously incur some small degree of TTS for a short duration of 
time. Because of the small degree anticipated, though, any PTS or TTS 
potentially incurred here would not be expected to adversely impact 
individual fitness, let alone annual rates of recruitment or survival.
    Behavioral responses of marine mammals to pile driving at the 
project site, if any, are expected to be mild and temporary. Marine 
mammals within the Level B harassment zone may not show any visual cues 
they are disturbed by activities or could become alert, avoid the area, 
leave the area, or display other mild responses that are not observable 
such as changes in vocalization patterns. Given the limited number of 
piles to be installed or extracted per day and that pile driving and 
removal would occur across a maximum of 150 days within the 12-month 
authorization period, any harassment would be temporary.
    Any impacts on marine mammal prey that would occur during 
Weyerhaeuser's proposed activity would have, at most, short-term 
effects on foraging of individual marine mammals, and likely no effect 
on the populations of marine mammals as a whole. Indirect effects on 
marine mammal prey during the construction are expected to be minor, 
and these effects are unlikely to cause substantial effects on marine 
mammals at the individual level, with no expected effect on annual 
rates of recruitment or survival.
    In addition, it is unlikely that minor noise effects in a small, 
localized area of habitat would have any effect on the stocks' annual 
rates of recruitment or survival. In combination, we believe that these 
factors, as well as the available body of evidence from other similar 
activities, demonstrate that the potential effects of the specified 
activities will have only minor, short-term effects on individuals. The 
specified activities are not expected to impact rates of recruitment or 
survival and 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 
authorized;
     The intensity of anticipated takes by Level B harassment 
is relatively low for all stocks and would not be of a duration or 
intensity expected to result in impacts on reproduction or survival;
     No important habitat areas have been identified within the 
project area;
     For all species, the Columbia River is a very small and 
peripheral part of their range and anticipated habitat impacts are 
minor; and
     Weyerhaeuser would implement mitigation measures, such as 
soft-starts for impact pile driving and shut downs to minimize the 
numbers of marine mammals exposed to injurious levels of sound, and to 
ensure that take by Level A harassment, is at most, a small degree of 
PTS.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from the proposed activity will have a negligible impact on 
all affected marine mammal species or stocks.

Small Numbers

    As noted previously, only take of small numbers of marine mammals 
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. When the predicted number of 
individuals to be taken is fewer than one-third of the species or stock 
abundance, the take is considered to be of small numbers. Additionally, 
other qualitative factors may be considered in the analysis, such as 
the temporal or spatial scale of the activities.
    Table 9 demonstrates the number of animals that could be exposed to 
received noise levels that could cause Level B harassment for the 
proposed work. Our analysis shows that less than 10 percent of each 
affected stock could be taken by harassment. The numbers of animals 
proposed to be taken for these stocks would be considered small 
relative to the relevant stock's abundances, even if each estimated 
taking occurred to a new individual--an extremely unlikely scenario.
    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.

[[Page 48597]]

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to Weyerhaeuser for conducting Log Export Dock Project, on 
the Columbia River near Longview, Washington, from September 1, 2025, 
through August 31, 2026, 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 Log 
Export Dock 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 is planned, or (2) the activities as described in the 
Description of Proposed Activity section 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, 
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: June 3, 2024.
Catherine Marzin,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2024-12473 Filed 6-6-24; 8:45 am]
BILLING CODE 3510-22-P