[Federal Register Volume 87, Number 126 (Friday, July 1, 2022)]
[Notices]
[Pages 39481-39500]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-14138]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XC102]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Sand Island Pile Dikes Repairs in 
the Columbia River

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

ACTION: Notice; proposed incidental harassment authorizations (IHAs); 
request for comments on proposed authorizations and possible renewal.

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SUMMARY: NMFS has received a request from the U.S. Army Corps of 
Engineers (Corps) for authorization to take marine mammals incidental 
to the Sand Island Pile Dikes Repairs Project in the Columbia River. 
Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting 
comments on its proposal to issue two consecutive IHAs to incidentally 
take marine mammals during the specified activities. NMFS is also 
requesting comments on possible one-time, one-year renewals for each 
IHA that could be issued under certain circumstances and if all 
requirements are met, as described in Request for Public Comments at 
the end of this notice. NMFS will consider public comments prior to 
making any final decision on the issuance of the requested MMPA 
authorization and agency responses will be summarized in the final 
notice of our decision.

DATES: Comments and information must be received no later than August 
1, 2022.

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 
<a href="/cdn-cgi/l/email-protection#024b56522c446d756e6770426c6d63632c656d74"><span class="__cf_email__" data-cfemail="eea7babec0a88199828b9cae80818f8fc0898198">[email protected]</span></a>.
    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 
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: Amy Fowler, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of problems 
accessing these documents, please call the contact listed above.

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

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an IHA) 
with respect to potential impacts on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for NOAA Administrative Order 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 IHAs 
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

[[Page 39482]]

or making a final decision on the IHA request.

Summary of Request

    On March 4, 2022, NMFS received a request from the Corps for two 
IHAs to take marine mammals incidental to the Sand Island Pile Dikes 
Repairs Project in the Columbia River over the course of two years. The 
application was deemed adequate and complete on June 9, 2022. The 
Corps' request is for take of 7 species of marine mammals by Level B 
harassment and, for a subset of these species (harbor seal (Phoca 
vitulina) and harbor porpoise (Phocoena phocoena)), Level A harassment. 
Neither the Corps nor NMFS expect serious injury or mortality to result 
from these activities and, therefore, IHAs are appropriate.

Description of Proposed Activity

Overview

    The Sand Island pile dikes are part of the Columbia River pile dike 
system and are comprised of 4 pile dikes, which are named according to 
river mile (RM) location, at RMs 4.01, 4.47, 5.15, and 6.37. The 
purpose of the Sand Island Pile Dikes Repairs project is to perform 
needed repairs. The existing timber pile dikes at Sand Island consist 
of three rows of vertical timber pilings between 12 and 20 inches (in) 
in diameter with two rows of horizontal spreaders, which provide 
structural stability of the vertical timber pilings. A cluster of piles 
with one or more taller piles, called an outer dolphin with king piles, 
is used to anchor and mark the end for navigational safety. There is 
rock apron at the base of the vertical piles and at the shore 
connection to protect against scour. The existing pile dikes have 
deteriorated greatly due to lack of maintenance.
    It was determined that at the channel-ward ends of the pile dikes, 
replacement of the existing, deteriorated piles with new piles is 
necessary but that in shallower water depths, it is possible to remove 
timber pilings completely and add rock for higher enrockment elevation 
to achieve equivalent hydraulic and sediment transport functions. The 
project design team also determined that steel piles can provide 
equivalent hydraulic function and do not require horizontal spreaders, 
thus reducing required construction materials. In addition it is 
feasible to cap steel piles with cones to discourage piscivorous bird 
perching.
    The major project elements proposed to be conducted under these 
IHAs include work at pile dikes 6.37 and 5.15. The Corps proposes to 
remove existing timber piles, drive new steel pipe piles and place rock 
for multiple purposes including scour protection at the base of the new 
piles, enhanced enrockment segments, shore connections, and revetment 
along the western portion of the shoreline at East Sand Island.

Dates and Duration

    The Sand Island Pile Dikes Repairs Project is planned to take a 
total of 3 or 4 years to complete, with in-water work beginning in 
August 2023. The first IHA would be valid from August 1, 2023 to July 
31, 2024, and the second would be valid August 1, 2024 through July 31, 
2025, but in-water work would only occur between August and November 
each year. The Corps would apply separately for the future IHA(s) to 
conduct similar work at pile dikes 4.01 and 4.47.

Specific Geographic Region

    One of the pile dikes is connected to West Sand Island (4.01), two 
of the pile dikes are connected to East Sand Island (4.47, 5.15), and 
the fourth pile dike (6.37) is in open water and runs parallel to the 
Chinook Federal Navigation Channel on the upstream side. The three pile 
dikes connected to West Sand Island and East Sand Island are located 
within Oregon, while the fourth pile dike in open water spans both 
Oregon and Washington. The Sand Island pile dikes are located in the 
downstream terminus of the Columbia River tidal estuary, which is 
dominated by freshwater inputs from the Columbia and Willamette rivers. 
This estuary stretches from the mouth upstream to Bonneville Dam at RM 
146.
[GRAPHIC] [TIFF OMITTED] TN01JY22.011


[[Page 39483]]



Detailed Description of Specific Activity

    Hydraulic modeling of the Sand Island Pile Dike System demonstrated 
that existing timber piles would need to be removed because leaving 
them in place would affect the hydraulic function of the new design. 
Existing timber piles may be removed by pulling, cutting or snapping at 
the approximate level of the enrockment. Vibratory hammers will not be 
used for timber pile removal. Pile removal is expected to proceed 
incrementally as replacement repairs are made to ensure that overall 
function is maintained during construction. The original construction 
of the four pile dikes included 3,936 timber piles. It is estimated 
that 20 percent of those are now missing and that approximately 3,000 
will be removed and disposed of. Take of marine mammals is not expected 
to occur from removal of timber piles, therefore the Corps has not 
calculated the precise number of piles to be removed and removal of 
timber piles will not be discussed further in this document.
    The proposed pile dike design is an offset of the existing pile 
dike alignment, with piles driven approximately 30 feet (ft; 9.1 meters 
(m)) downstream of existing centerline. The pile configuration needed 
to achieve hydraulic and sediment transport functions includes two rows 
of 24'' steel pipe piles, staggered and spaced 6.2 ft (1.9 m) on 
center. Each pile dike would be 80 ft (24.4 m) long.
    The Corps estimates a total of 376 24-in steel pipe piles would be 
installed at the two pile dike locations (pile dikes 6.37 and 5.15) and 
18 24-in steel pipe piles will be installed as marker piles along the 
enrockment at these two pile dikes (Tables 1 and 2). The expected 
minimum embedment depths for each pile are between approximately 30 and 
40 ft (9.1 to 12.2 m).
    The contractor may use barge-mounted cranes equipped with survey 
grade positioning software to ensure the piles are installed with 
precision. Piles are generally installed by a rig which supports the 
pile leads, raises the pile, and operates a hammer. The Corps 
anticipates that vibratory hammers would be used to start the pile 
driving and will drive them 50 percent of the way, and impact hammers 
would be used to complete the pile driving for the remaining 50 
percent. In the event that unusually difficult driving conditions are 
encountered, the contractor would be allowed to temporarily excavate 
the minimum amount of existing scour protection rock needed in order to 
drive the new pile. The contractor would then reinstall the rock to 
provide scour protection for the new pile.
    Land based work would be necessary at pile dike 5.15 to remove some 
existing timber piles and improve the existing pile dike shore 
connections and sections of enhanced enrockment that are too shallow 
for barge-based equipment access. Construction of pile dike 6.37 would 
occur by over-water equipment only. Conceptual locations for a 
temporary material off-loading facility (MOF) and staging areas have 
been chosen based upon multiple constraints including cultural 
resources, avian presence, ordinary high water depths, and tidal 
currents, especially during ebb tide. Approaching and landing a barge 
may not be feasible or safe during some periods of the day during high 
tidal velocities. The MOF pilings supporting dolphins would be 
installed by barge using vibratory pile driving only. It is estimated 
that a maximum of 24 steel pipe piles with a maximum diameter of 24 
inch and up to 100 (24-inch) AZ steel sheet piles would be required for 
the MOF. All piles installed to construct the MOF would be subsequently 
removed in the same year.

                                                          Table 1--Year 1 Proposed Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                          Duration or
       Project element           Pile size and        Method         Number of piles     Maximum piles    strikes per    Estimated days  Estimated month
                                     type                                                   per day           pile           of work         of work
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pile dike 6.37...............  24-in steel pipe  Vibratory         171 \a\............          \b\ 14  15 minutes.....              56  August-Septembe
                                                  install.                                                                                r.
Pile dike 6.37...............  24-in steel pipe  Impact install                                         225 strikes....
MOF..........................  24-in steel pipe  Vibratory         Up to 24 \c\.......               5  30 minutes.....               5  October.
                                                  install.
MOF..........................  24-in steel pipe  Vibratory                                          20  5 minutes......               1  October.
                                                  removal
MOF..........................  24-in steel       Vibratory         Up to 100 \c\......              25  10 minutes.....               4  October.
                                sheet.            install.
MOF..........................  24-in steel       Vibratory                                          50  3 minutes......               1  October.
                                sheet.            removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
    Total days of work.................................................................................................              67
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ A total of 244 steel pipe piles will be installed at PD 6.37 over the two years, with approximately 70 percent installed in year 1 and the remaining
  30 percent installed in year 2. These same 171 piles will be installed using both vibratory and impact hammers.
\b\ The Corps estimates an average of 5 piles will be installed per day but could be up to 14 per day.
\c\ The same MOF piles will be installed and subsequently removed.


                                                          Table 2--Year 2 Proposed Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                          Duration or
       Project element           Pile size and        Method         Number of piles     Maximum piles    strikes per    Estimated days  Estimated month
                                     type                                                   per day           pile           of work         of work
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pile dike 6.37...............  24-in steel pipe  Vibratory         73 \a\.............          \b\ 14  15 min.........              24  August.
                                                  install.
                                                 Impact install                                         225 strikes.
Pile dike 5.15...............  24-in steel pipe  Vibratory         150................              14  15 min.........              71  August-November
                                                  install.                                                                                .
                                                 Impact install                                         225 strikes.
--------------------------------------------------------------------------------------------------------------------------------------------------------
    Total days of work.................................................................................................              95
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ These same 73 piles will be installed using both vibratory and impact hammers.
\b\ The Corps estimates an average of 5 piles will be installed per day but could be up to 14 per day.

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

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions, incorporated here by reference, instead of 
reprinting the information.

[[Page 39484]]

Additional information regarding population trends and threats may be 
found in NMFS' Stock Assessment Reports (SARs; 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 3 lists all species or stocks for which take is expected and 
proposed to be authorized for this activity, and summarizes information 
related to the population or stock, including regulatory status under 
the MMPA and Endangered Species Act (ESA) and potential biological 
removal (PBR), where known. PBR is defined by the MMPA as the maximum 
number of animals, not including natural mortalities, that may be 
removed from a marine mammal stock while allowing that stock to reach 
or maintain its optimum sustainable population (as described in NMFS' 
SARs). While no serious injury or mortality is anticipated or 
authorized here, PBR and annual serious injury and mortality from 
anthropogenic sources are included here as gross indicators of the 
status of the species and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS' U.S. Pacific and Alaska SARs. All values presented in Table 3 are 
the most recent available at the time of publication and are available 
in the 2020 SARs (Carretta et al., 2021; Muto et al., 2022) and draft 
2021 SARs (available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).

                          Table 3--Species Likely Impacted by the Specified Activities
----------------------------------------------------------------------------------------------------------------
                                                                             Stock abundance
                                                                  ESA/MMPA      (CV, Nmin,
         Common name           Scientific name       Stock         status;     most recent       PBR     Annual
                                                                  strategic     abundance               M/SI \3\
                                                                  (Y/N) \1\    survey) \2\
----------------------------------------------------------------------------------------------------------------
                      Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
----------------------------------------------------------------------------------------------------------------
Family Balaenopteridae
 (rorquals):
    Humpback whale...........  Megaptera        California/      E, D, Y     4,973 (0.05,         28.7    >=48.6
                                novaeangliae.    Oregon/                      4,776, 2018).
                                                 Washington.
----------------------------------------------------------------------------------------------------------------
                        Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
----------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Killer Whale.............  Orcinus orca...  West Coast       -,-, N      349 \4\ (N/A,         3.5       0.4
                                                 Transient.                   349, 2018).
Family Phocoenidae
 (porpoises):
    Harbor Porpoise..........  Phocoena         Northern Oregon/ -,-, N      21,487 (0.44,         151     >=3.0
                                phocoena.        Washington                   15,123, 2011).
                                                 Coast.
----------------------------------------------------------------------------------------------------------------
                                     Order Carnivora--Superfamily Pinnipedia
----------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals
 and sea lions):
    California Sea Lion......  Zalophus         U.S............  -,-, N      257,606 (N/        14,011      >320
                                californianus.                                A,233,515,
                                                                              2014).
    Steller Sea Lion.........  Eumetopias       Eastern........  -,-, N      43,201 \5\ (see     2,592       112
                                jubatus.                                      SAR, 43,201,
                                                                              2017).
Family Phocidae (earless
 seals):
    Harbor Seal..............  Phoca vitulina.  Oregon/          -,-, N      24,732 \6\            UND      10.6
                                                 Washington                   (UNK, UNK,
                                                 Coast.                       1999).
    Northern Elephant Seal...  Mirounga         California       -,-, N      187,386 (N/A,       5,122      13.7
                                angustirostris.  Breeding.                    85,369, 2013).
----------------------------------------------------------------------------------------------------------------
\1\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species
  is not listed under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one
  for which the level of direct human-caused mortality exceeds PBR or which is determined to be declining and
  likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
  automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://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.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury
  from all sources combined (e.g., commercial fisheries, ship strike). Annual mortality/serious injury (M/SI)
  often cannot be determined precisely and is in some cases presented as a minimum value or range.
\4\ Based on counts of individual animals identified from photo-identification catalogues. Surveys for abundance
  estimates of these stocks are conducted infrequently.
\5\ Best estimate of pup and non-pup counts, which have not been corrected to account for animals at sea during
  abundance surveys.
\6\ The abundance estimate for this stock is greater than eight years old and is therefore not considered
  current. PBR is considered undetermined for this stock, as there is no current minimum abundance estimate for
  use in calculation. We nevertheless present the most recent abundance estimates, as these represent the best
  available information for use in this document.

    As indicated above, all 6 species (with 6 managed stocks) in Table 
3 temporally and spatially co-occur with the activity to the degree 
that take is reasonably likely to occur. All species that could 
potentially occur in the proposed project area are included in Table 4 
of the IHA application. While gray whales (Eschrichtius robustus) and 
killer whales from the Southern Resident Distinct Population Segment 
(DPS) and stock have been reported near the mouth of the Columbia 
River, the temporal and/or spatial occurrence of these species is such 
that take is not expected to occur, and they are not discussed further 
beyond the explanation provided here.
    Gray whales have not been documented near the proposed project area 
although anecdotal evidence indicates they have been seen at the mouth 
of the Columbia River. However, they are not a common visitor as they 
mostly remain in the vicinity of the offshore shelf-break (Griffith 
2015). They migrate along the Oregon coast in three discernible phases 
from early December through May (Herzing and Mate 1984). Therefore, 
they are unlikely

[[Page 39485]]

to occur near the project area between August and November. Monitoring 
reports from recent IHAs issued to the Corps for similar construction 
work on the Columbia River Jetty System (e.g., 82 FR 15046; March 23, 
2017) reported no observations of gray whales. Given the size of gray 
whales, they could be readily identifiable at a considerable distance. 
If a gray whale were to approach the established Level B harassment 
isopleths, shutdown would be initiated to avoid take. The Corps would 
employ at least one vessel-based protected species observer (PSO) who 
would be able to adequately monitor these zones. Therefore, NMFS does 
expect take of gray whales to occur and no take is proposed to be 
authorized.
    Historically, killer whales were regular visitors in the vicinity 
of the estuary. However, they are much less common presently and are 
rarely seen in the interior of the Columbia River Jetty system (Wilson 
2015). Southern Resident killer whales have been documented near the 
mouth of the Columbia River but these observations have most commonly 
been during the late-winter to early-spring months (NMFS 2021), outside 
of the proposed construction window for these projects. Monitoring 
reports from recent IHAs issued to the Corps for similar construction 
work on the Columbia River Jetty System (e.g., 82 FR 15046; March 23, 
2017) reported no observations of killer whales. While it is possible 
that killer whales from the West Coast Transient stock may enter the 
project area (see Estimated Take section), it is unlikely that take of 
Southern Resident killer whales would occur, and no take is proposed to 
be authorized.

Humpback Whale

    Prior to 2016, humpback whales were listed under the ESA as an 
endangered species worldwide. Following a 2015 global status review 
(Bettridge et al., 2015), NMFS delineated 14 distinct population 
segments (DPSs) with different listing statuses (81 FR 62259; September 
8, 2016) pursuant to the ESA. The DPSs that occur in U.S. waters do not 
necessarily equate to the existing stocks designated under the MMPA and 
shown in Table 1. Because MMPA stocks cannot be portioned, i.e., parts 
managed as ESA-listed while other parts managed as not ESA-listed, 
until such time as the MMPA stock delineations are reviewed in light of 
the DPS designations, NMFS considers the existing humpback whale stocks 
under the MMPA that overlap with endangered or threatened DPSs to be 
depleted for MMPA management purposes (e.g., selection of a recovery 
factor, stock status). All humpback whales in the project area would be 
from the California/Oregon/Washington stock (Carretta et al., 2019). 
These animals belong almost exclusively to the Mexican and Central 
American DPSs, which are listed as threatened and endangered under the 
ESA, respectively. According to Wade et al. (2021), the probability 
that humpback whales encountered in Oregon and California (i.e., south 
of the Columbia River) are as follows: Mexico DPS, 58 percent; and 
Central America DPS, 42 percent. In Washington and Southern British 
Columbia waters (i.e., north of the Columbia River) are as follows: 
Hawai'i DPS (unlisted), 69 percent; Mexico DPS, 25 percent; and Central 
America DPS, 6 percent (Wade et al., 2021). Since the Columbia River is 
considered the dividing line between these two areas, the exact 
proportion of humpback whales taken incidental to the Corps' activities 
from each of the three DPSs cannot be determined; however, we assume 
some of the humpback whales taken would be from a listed DPS.
    Humpback whales are primarily found on the continental shelf and 
slope (Adams et al., 2014). Humpback whales are typically seen off the 
Oregon coast from April to October, with peak numbers from June through 
August (Green et al., 1991). Humpback whale feeding groups have begun 
utilizing the mouth of the Columbia River as foraging ground, arriving 
in the lower Columbia estuary as early as mid-June, and have been 
observed as late as mid-November with a peak of abundance coinciding 
with the peak abundance of forage fish in mid-summer. Humpback whales 
were observed in the immediate vicinity of West and East Sand Islands 
in late summer and fall of 2015 and 2016 (The Columbian, 2016). They 
were also observed in the area in 2017 and 2019, but their presence was 
not documented there in 2018 (The Columbian, 2019). Most recently they 
were again seen earlier in the season than ever, at the beginning of 
April in 2020 (Chinook Observer, 2020). Based on this information, it 
is possible that humpback whales may pass through and may forage 
intermittently in the immediate project vicinity.

Killer Whale

    Killer whales are found in waters throughout the North Pacific. 
Along the west coast of North America, `resident,' transient,' and 
`offshore' ecotypes have overlapping distributions and multiple stocks 
are recognized within that broader classification scheme. The West 
Coast Transient stock includes animals that range from California to 
southern Alaska, and is genetically distinct from other transient 
populations in the region (i.e., Gulf of Alaska, Aleutian Islands, and 
Bering Sea transients and AT1 transients) (Carretta et al., 2021; Muto 
et al., 2021). The main diet of transient killer whales consists of 
marine mammals. Along the Washington and Oregon coast, transient killer 
whales primarily hunt pinnipeds and porpoises, though some groups will 
occasionally target larger whales. The seasonal movements of transients 
are largely unpredictable, although there is a tendency to investigate 
harbor seal haulouts off Vancouver Island more frequently during the 
pupping season in August and September (Baird 1994; Ford 2014). While 
not regularly seen in the project area, transient killer whales have 
been observed near the mouth of the Columbia River in March and April 
and a pod of transient killer whales were detected near the Astoria 
Bridge in May of 2018 (Frankowicz 2018).

Harbor Porpoise

    In the eastern North Pacific Ocean, harbor porpoise are found in 
coastal and inland waters from Point Barrow, along the Alaskan coast, 
and down the west coast of North America to Point Conception, 
California. Harbor porpoise are known to occur year-round in the inland 
trans-boundary waters of Washington and British Columbia, Canada and 
along the Oregon/Washington coast. The Northern Oregon/Washington Coast 
stock of harbor porpoises ranges from Lincoln City, OR, to Cape 
Flattery, WA (Carretta et al., 2019).
    Harbor porpoises are usually found in shallow water, most often 
nearshore, although they occasionally travel over deeper offshore 
waters (NOAA 2013a). West Coast populations have more restricted 
movements and do not migrate as much as East Coast populations (Halpin, 
OBIS-SEAMAP 2019). Most harbor porpoise groups are small, generally 
consisting of less than five or six individuals, though for feeding or 
migration they may aggregate into large, loose groups of 50 to several 
hundred animals (Halpin, OBIS-SEAMAP 2019). Behavior tends to be 
inconspicuous, compared to most dolphins, and they feed by seizing prey 
which consists of wide variety of fish and cephalopods ranging from 
benthic or demersal (Halpern, OBIS-SEAMAP 2019). Harbor porpoises are 
sighted year round near the mouth of the Columbia River (Griffith 
2015). Their abundance peaks with the abundance of anchovy presence in 
the river and nearshore.

[[Page 39486]]

California Sea Lion

    California sea lions are found along the west coast from the 
southern tip of Baja California to southeast Alaska. They breed mainly 
on offshore islands from Southern California's Channel Islands south to 
Mexico. Non-breeding males often roam north in spring foraging for 
food. Since the mid-1980s, increasing numbers of California sea lions 
have been documented feeding on fish along the Washington coast and--
more recently--in the Columbia River as far upstream as Bonneville Dam, 
145 mi (233 km) from the river mouth. Large numbers of California sea 
lions use the nearby South Jetty for hauling out (Jeffries 2000). 
According to Oregon Department of Fish and Wildlife (ODFW 2014) counts, 
most California sea lions are concentrated near the tip of the South 
Jetty. ODFW survey information (2007 and 2014) indicates that 
California sea lions are relatively less prevalent in the Pacific 
Northwest during June and July, though in the months just before and 
after their absence there can be several hundred using the South Jetty. 
More frequent Washington Department of Fish and Wildlife (WDFW 2014) 
surveys indicate greater numbers in the summer, and use remains 
concentrated to fall and winter months. Nearly all California sea lions 
in the Pacific Northwest are sub-adult and adult males (females and 
young generally stay in California).

Steller Sea Lion

    The range of the Steller sea lion includes the North Pacific Ocean 
rim from California to northern Japan. Steller sea lions forage in 
nearshore and pelagic waters where they are opportunistic predators. 
There are two separate stocks of Steller sea lions, the Eastern U.S. 
stock, which occurs east of Cape Suckling, Alaska (144[deg] W), and the 
Western U.S. stock, which occurs west of that point. Only the Western 
stock of Steller sea lions, which is designated as the Western DPS of 
Steller sea lions, is listed as endangered under the ESA (78 FR 66139; 
November 4, 2013). Unlike the Western U.S. stock of Steller sea lions, 
there has been a sustained and robust increase in abundance of the 
Eastern U.S. stock throughout its breeding range. The eastern stock of 
Steller sea lions has historically bred on rookeries located in 
Southeast Alaska, British Columbia, Oregon, and California.
    Large numbers of Steller sea lions use the nearby South Jetty for 
hauling out (Jeffries 2000) and are present, in varying abundances, all 
year. Use occurs chiefly at the concrete block structure at the 
terminus, or head of the jetty. According to ODFW (2014), during the 
summer months it is not uncommon to observe between 500-1,000 Steller 
sea lions present per day. Steller sea lions are most abundant in the 
vicinity during the winter months and tend to disperse elsewhere to 
rookeries during breeding season between May and July (Corps 2007). All 
population age classes, and both males and females, use the South Jetty 
to haul out.
    While California sea lions also use this area and can intermingle 
with Steller sea lions, it appears that Steller out-compete California 
sea lions for the preferred haul out area. Previous monthly averages 
between 1995 and 2004 for Steller sea lions hauled out at the South 
Jetty head ranged from about 168 to 1,106 animals. ODFW data from 2000-
2014 reflects a lower frequency of surveys, and numbers ranged from 
zero animals to 606 Steller sea lions (ODFW 2014). More frequent 
surveys by WDFW for the same time frame (2000-2014) put the monthly 
range at 177 to 1,663 animals throughout the year.

Pacific Harbor Seal

    Harbor seals range from Baja California, north along the western 
coasts of the United States, British Columbia and southeast Alaska, 
west through the Gulf of Alaska, Prince William Sound, and the Aleutian 
Islands, and north in the Bering Sea to Cape Newenham and the Pribilof 
Islands. They are one of the most abundant pinnipeds in Oregon and can 
typically be found in coastal marine and estuarine waters of the Oregon 
coast throughout the year. On land, they can be found on offshore rocks 
and islands, along shore, and on exposed flats in the estuary (Harvey 
1987). In 2002, the estimated absolute abundance of harbor seals on the 
Oregon coast (excluding Hunters Island) was 10,087 (95 percent 
confidence interval: 8,445-12,046) animals (Brown et al., 2005). Harbor 
seals are known to use the Chinook Channel/Baker Bay area during low 
tides for hauling out (Jeffries 2000). They haul out on rocks, reefs, 
beaches, and drifting glacial ice and feed in marine, estuarine, and 
occasionally fresh waters. Harbor seals generally are non-migratory, 
with local movements associated with tides, weather, season, food 
availability, and reproduction. Harbor seals do not make extensive 
pelagic migrations (Carretta et al., 2019). The most recent estimated 
population of harbor seals in the Oregon/Washington Coast stock was 
24,732 based on surveys conducted in 1999 (Carretta et al., 2014). 
Based on the analyses of Jeffries et al. (2003) and Brown et al. 
(2005), both the Washington and Oregon portions of this stock were 
reported as reaching carrying capacity. However, in the absence of 
recent abundance estimates, the current population trend is unknown.

Northern Elephant Seal

    The California Breeding Stock of Northern elephant seals (Mirounga 
angustirostris) breeds and gives birth in California, but makes 
extended foraging trips to areas including coastal Oregon biannually 
during the fall and spring (Le Boeuf et al., 2000). They spend about 90 
percent of their time at sea underwater, making sequential deep dives. 
While both males and females may transit areas off the Oregon coast, 
males seem to have focal forage areas near the continental shelf break 
while females typically move further offshore and feed 
opportunistically at numerous sites while in route (Le Beouf et al., 
2000). Prior to 1984, only two sightings of Northern elephant seals 
were recorded (Jeffries 1984). Since then, they have been seen 
infrequently near the mouth of the Columbia River.

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 4.

[[Page 39487]]



                  Table 4--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
               Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen         7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans (dolphins,      150 Hz to 160 kHz.
 toothed whales, beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans (true          275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 Cephalorhynchid, Lagenorhynchus cruciger &
 L. australis).
Phocid pinnipeds (PW) (underwater) (true     50 Hz to 86 kHz.
 seals).
Otariid pinnipeds (OW) (underwater) (sea     60 Hz to 39 kHz.
 lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).

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

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section includes a discussion of the ways that components of 
the specified activity may impact marine mammals and their habitat. The 
Estimated Take 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 section, and 
the Proposed Mitigation section, to draw conclusions regarding the 
likely impacts of these activities on the reproductive success or 
survivorship of individuals and whether those impacts are reasonably 
expected to, or reasonably likely to, adversely affect the species or 
stock through effects on annual rates of recruitment or survival.
    Acoustic effects on marine mammals during the specified activities 
can occur from impact pile driving and vibratory driving and removal. 
The effects of underwater noise from the Corps' proposed activities 
have the potential to result in Level A or Level B harassment of marine 
mammals in the action areas.

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 (ANSI 1995). The sound level of an area is 
defined by the total acoustical energy being generated by known and 
unknown sources. These sources may include physical (e.g., waves, wind, 
precipitation, earthquakes, ice, atmospheric sound), biological (e.g., 
sounds produced by marine mammals, fish, and invertebrates), and 
anthropogenic sound (e.g., vessels, dredging, aircraft, construction).
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 
decibels (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 activities 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 impact and vibratory pile driving and removal. The sounds 
produced by these activities fall into one of two general sound types: 
impulsive and non-impulsive. Impulsive sounds (e.g., explosions, 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 (ANSI, 1986; NIOSH, 1998; NMFS, 2018). Non-
impulsive sounds (e.g., machinery operations such as drilling or 
dredging, vibratory pile driving, underwater chainsaws, 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).
    Two types of hammers would be used on this project, impact and 
vibratory. Impact hammers operate by repeatedly dropping and/or pushing 
a heavy piston onto a pile to drive the pile into the substrate. Sound 
generated by impact hammers is considered impulsive. Vibratory hammers 
install piles by vibrating them and allowing the weight of the hammer 
to push them into the sediment. Vibratory hammers produce non-
impulsive, continuous sounds. Vibratory hammering generally produces 
SPLs 10 to 20 dB lower than 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 the Corps' proposed activities on 
marine mammals could be generated from both non-acoustic and acoustic 
stressors. Potential non-acoustic stressors include the physical 
presence of the equipment, vessels, and personnel; however, we expect 
that any animals that approach the project site(s) close enough to be 
harassed due to the presence of equipment or personnel would be within 
the Level B harassment zones from pile driving and would already be 
subject to harassment from the in-water activities. Therefore, any 
impacts to marine mammals are expected to

[[Page 39488]]

primarily be acoustic in nature. Acoustic stressors are generated by 
heavy equipment operation during pile installation and removal (i.e., 
impact and vibratory pile driving and removal).

Acoustic Impacts

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving equipment is the primary means by which 
marine mammals may be harassed from the Corps' specified activities. 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). Generally, exposure to 
pile driving and removal and other construction noise has the potential 
to result in auditory threshold shifts and behavioral reactions (e.g., 
avoidance, temporary cessation of foraging and vocalizing, changes in 
dive behavior). Exposure to anthropogenic noise can also lead to non-
observable physiological responses such as an increase in stress 
hormones. Additional noise in a marine mammal's habitat can mask 
acoustic cues used by marine mammals to carry out daily functions such 
as communication and predator and prey detection. The effects of pile 
driving and demolition 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. 
mother 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. No 
physiological effects other than PTS are anticipated or proposed to be 
authorized, and therefore are not discussed further.
    NMFS defines a noise-induced threshold shift (TS) as a change, 
usually an increase, in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS, 2018). The amount of 
threshold shift 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 
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), likelihood an individual would be exposed for a long enough 
duration or to a high enough level to induce a TS, the magnitude of the 
TS, time to recovery (seconds to minutes or hours to days), the 
frequency range of the exposure (i.e., spectral content), the hearing 
and vocalization frequency range of the exposed species relative to the 
signal's frequency spectrum (i.e., how animal uses sound within the 
frequency band of the signal; e.g., Kastelein et al., 2014), and the 
overlap between the animal and the source (e.g., spatial, temporal, and 
spectral).
    Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). Available data from 
humans and other terrestrial mammals indicate that a 40 dB threshold 
shift approximates PTS onset (see Ward et al., 1958, 1959; Ward, 1960; 
Kryter et al., 1966; Miller, 1974; Ahroon et al., 1996; Henderson et 
al., 2008). PTS levels for marine mammals are estimates, because there 
are limited empirical data measuring PTS in marine mammals (e.g., 
Kastak et al., 2008), largely due to the fact that, for various ethical 
reasons, experiments involving anthropogenic noise exposure at levels 
inducing PTS are not typically pursued or authorized (NMFS, 2018).
    Temporary Threshold Shift (TTS)--TTS is a temporary, reversible 
increase in the threshold of audibility at a specified frequency or 
portion of an individual's hearing range above a previously established 
reference level (NMFS, 2018). Based on data from cetacean TTS 
measurements (see Southall et al., 2007), a TTS of 6 dB is considered 
the minimum threshold shift clearly larger than any day-to-day or 
session-to-session variation in a subject's normal hearing ability 
(Schlundt et al., 2000; Finneran et al., 2000, 2002). As described in 
Finneran (2016), marine mammal studies have shown the amount of TTS 
increases with cumulative sound exposure level (SEL<INF>cum</INF>) in 
an accelerating fashion: At low exposures with lower SEL<INF>cum</INF>, 
the amount of TTS is typically small and the growth curves have shallow 
slopes. At exposures with higher SEL<INF>cum</INF>, 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 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.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor 
porpoise, and Yangtze finless porpoise (Neophocoena asiaeorientalis)) 
and five species of pinnipeds exposed to a limited number of sound 
sources (i.e., mostly tones and octave-band noise) in laboratory 
settings (Finneran, 2015). TTS was not observed in trained spotted 
(Phoca largha) and ringed (Pusa hispida) seals exposed to impulsive 
noise at levels matching previous predictions of TTS onset (Reichmuth 
et al., 2016). In general, harbor seals and harbor porpoises have a 
lower TTS onset than other measured pinniped or cetacean species 
(Finneran, 2015). The potential for TTS from impact pile driving 
exists. After exposure to playbacks of impact pile driving sounds (rate 
2,760 strikes/hour) in captivity, mean TTS increased from 0 dB after 15 
minute exposure to 5 dB after 360 minute exposure; recovery occurred 
within 60 minutes (Kastelein et al., 2016). Additionally, the existing 
marine mammal TTS data come from a limited number of individuals within 
these species. No data are available on noise-induced hearing loss for 
mysticetes. Nonetheless, what we considered is the best available 
science. For summaries of data on TTS in marine mammals or for further 
discussion of TTS onset thresholds, please see Southall et al. (2007), 
Finneran and Jenkins (2012), Finneran (2015), and Table 5 in NMFS 
(2018).
    Installing piles for this project requires impact pile driving. 
There would likely be pauses in activities producing the sound during 
each day. Given these pauses and the fact that many marine mammals are 
likely moving through the project areas and not remaining for extended 
periods of time, the potential for TS declines.

[[Page 39489]]

    Behavioral Harassment--Exposure to noise from pile driving and 
removal also has the potential to behaviorally disturb marine mammals. 
Available studies show wide variation in response to underwater sound; 
therefore, it is difficult to predict specifically how any given sound 
in a particular instance might affect marine mammals perceiving the 
signal. If a marine mammal does react briefly to an underwater sound by 
changing its behavior or moving a small distance, the impacts of the 
change are unlikely to be significant to the individual, let alone the 
stock or population. However, if a sound source displaces marine 
mammals from an important feeding or breeding area for a prolonged 
period, impacts on individuals and populations could be significant 
(e.g., Lusseau and Bejder, 2007; Weilgart, 2007; NRC, 2005).
    Disturbance may result in changing durations of surfacing and 
dives, number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities; changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping); 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., 2004; 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 and 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.
    In 2016, the Alaska Department of Transportation and Public 
Facilities (ADOT&PF) documented observations of marine mammals during 
construction activities (i.e., pile driving) at the Kodiak Ferry Dock 
(see 80 FR 60636, October 7, 2015). In the marine mammal monitoring 
report for that project (ABR 2016), 1,281 Steller sea lions were 
observed within the Level B disturbance zone during pile driving or 
drilling (i.e., documented as Level B harassment take). Of these, 19 
individuals demonstrated an alert behavior, 7 were fleeing, and 19 swam 
away from the project site. All other animals (98 percent) were engaged 
in activities such as milling, foraging, or fighting and did not change 
their behavior. In addition, two sea lions approached within 20 m of 
active vibratory pile driving activities. Three harbor seals were 
observed within the disturbance zone during pile driving activities; 
none of them displayed disturbance behaviors. Fifteen killer whales and 
three harbor porpoise were also observed within the Level B harassment 
zone during pile driving. The killer whales were travelling or milling 
while all harbor porpoises were travelling. No signs of disturbance 
were noted for either of these species. Given the similarities in 
species, activities, and habitat (e.g., cool-temperate waters, 
industrialized area), we expect similar behavioral responses from the 
same and similar species affected by the Corps' specified activities. 
That is, disturbance, if any, is likely to be temporary and localized 
(e.g., small area movements).
    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

[[Page 39490]]

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 these projects based on observations 
of marine mammals during previous, similar projects in the area.
    Masking--Sound can disrupt behavior through masking, or interfering 
with, an animal's ability to detect, recognize, or discriminate between 
acoustic signals of interest (e.g., those used for intraspecific 
communication and social interactions, prey detection, predator 
avoidance, navigation) (Richardson et al., 1995). Masking occurs when 
the receipt of a sound is interfered with by another coincident sound 
at similar frequencies and at similar or higher intensity, and may 
occur whether the sound is natural (e.g., snapping shrimp, wind, waves, 
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar, 
seismic exploration) in origin. The ability of a noise source to mask 
biologically important sounds depends on the characteristics of both 
the noise source and the signal of interest (e.g., signal-to-noise 
ratio, temporal variability, direction), in relation to each other and 
to an animal's hearing abilities (e.g., sensitivity, frequency range, 
critical ratios, frequency discrimination, directional discrimination, 
age or TTS hearing loss), and existing ambient noise and propagation 
conditions. Masking of natural sounds can result when human activities 
produce high levels of background sound at frequencies important to 
marine mammals. Conversely, if the background level of underwater sound 
is high (e.g., on a day with strong wind and high waves), an 
anthropogenic sound source would not be detectable as far away as would 
be possible under quieter conditions and would itself be masked. The 
mouth of the Columbia River area contains active commercial shipping 
and commercial fishing as well as numerous recreational and other 
commercial vessels, and background sound levels in the area are already 
elevated.
    Airborne Acoustic Effects--Pinnipeds that occur near the project 
site could be exposed to airborne sounds associated with pile driving 
and removal that have the potential to cause behavioral harassment, 
depending on their distance from pile driving activities. Cetaceans are 
not expected to be exposed to airborne sounds that would result in 
harassment as defined under the MMPA.
    Airborne noise would primarily be an issue for pinnipeds that are 
swimming or hauled out near the project site within the range of noise 
levels elevated above the acoustic criteria. We recognize that 
pinnipeds in the water could be exposed to airborne sound that may 
result in behavioral harassment when looking with their heads above 
water. Most likely, airborne sound would cause behavioral responses 
similar to those discussed above in relation to underwater sound. For 
instance, anthropogenic sound could cause hauled-out pinnipeds to 
exhibit changes in their normal behavior, such as reduction in 
vocalizations, or cause them to temporarily abandon the area and move 
further from the source. However, these animals would likely previously 
have been `taken' because of exposure to underwater sound above the 
behavioral harassment thresholds, which are generally larger than those 
associated with airborne sound. Thus, the behavioral harassment of 
these animals is already accounted for in these estimates of potential 
take. Therefore, we do not believe that authorization of incidental 
take resulting from airborne sound for pinnipeds is warranted, and 
airborne sound is not discussed further here.

Marine Mammal Habitat Effects

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

In-Water Construction Effects on Potential Foraging Habitat

    The area likely impacted by the project is relatively small 
compared to the available habitat in the lower Columbia River. The area 
is highly influenced by anthropogenic activities. The total seafloor 
area affected by pile installation and removal is a small area compared 
to the vast foraging area available to marine mammals in the area. At 
best, the impact area provides marginal foraging habitat for marine 
mammals and fishes. Furthermore, pile driving and removal at the 
project site would not obstruct long-term movements or migration of 
marine mammals.
    Avoidance by potential prey (i.e., fish or, in the case of 
transient killer whales, other marine mammals) of the immediate area 
due to the temporary loss of this foraging habitat is also possible. 
The duration of fish and marine mammal avoidance of this area after 
pile driving stops is unknown, but a rapid return to normal 
recruitment, distribution, and behavior is anticipated. Any behavioral 
avoidance by fish or marine mammals of the disturbed area would still 
leave significantly large areas of fish and marine mammal foraging 
habitat in the nearby vicinity.
    In-water Construction Effects on Potential Prey--Sound may affect 
marine mammals through impacts on the abundance, behavior, or 
distribution of prey species (e.g., crustaceans, cephalopods, fish, 
zooplankton, other marine mammals). Marine mammal prey varies by 
species, season, and location. Here, we describe studies regarding the 
effects of noise on known marine mammal prey other than other marine 
mammals (which have been discussed earlier).
    Fish utilize the soundscape and components of sound in their

[[Page 39491]]

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

Estimated Take

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

[[Page 39492]]

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.
    The Corps' proposed activities includes the use of continuous 
(vibratory hammer) and impulsive (impact hammer) sources, and therefore 
the 120 and 160 dB re 1 [mu]Pa (rms) thresholds are applicable.
    Level A Harassment--NMFS' Technical Guidance for Assessing the 
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0) 
(Technical Guidance, 2018) identifies dual criteria to assess auditory 
injury (Level A harassment) to five different marine mammal groups 
(based on hearing sensitivity) as a result of exposure to noise from 
two different types of sources (impulsive or non-impulsive). The Corps' 
activities include the use of impulsive (impact hammer) and non-
impulsive (vibratory hammer) 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: 
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

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

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that are used in estimating the area ensonified above the 
acoustic thresholds, including source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the proposed project. 
Marine mammals are expected to be affected by sound generated by the 
primary components of the project (i.e., impact and vibratory pile 
driving).
    In order to calculate distances to the Level A harassment and Level 
B harassment thresholds for the methods and piles being used in this 
project, NMFS used acoustic monitoring data from other locations to 
develop source levels for the various pile types, sizes, and methods 
the Corps proposes to use (Table 6).

                                             Table 6--Source Levels
----------------------------------------------------------------------------------------------------------------
                                                 Source level (dB re 1 [mu]Pa)
      Pile type and method       ------------------------------------------------------------      Reference
                                         Peak                 RMS                 SEL
----------------------------------------------------------------------------------------------------------------
24-in steel pipe impact           203 dB............  190 dB............  177 dB............  CalTrans (2015).
 installation.
24-in steel pipe pile vibratory   Not available.....  161 dB............  Not available.....  U.S. Navy (2015).
 installation/removal.
24-in steel sheet pile vibratory  175 dB............  160 dB............  160 dB............  CalTrans (2015).
 installation/removal.
----------------------------------------------------------------------------------------------------------------


[[Page 39493]]

Level B Harassment Zones

    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 * 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

    The recommended TL coefficient for most nearshore environments is 
the practical spreading value of 15. This value results in an expected 
propagation environment that would lie between spherical and 
cylindrical spreading loss conditions, which is the most appropriate 
assumption for the Corps' proposed activities in the absence of 
specific modelling. The Level B harassment zones for the Corps' 
proposed activities are shown in Table 7.

Level A Harassment Zones

    The ensonified area associated with Level A harassment is more 
technically challenging to predict due to the need to account for a 
duration component. Therefore, NMFS developed an optional User 
Spreadsheet tool to accompany the Technical Guidance that can be used 
to relatively simply predict an isopleth distance for use in 
conjunction with marine mammal density or occurrence to help predict 
potential takes. We note that because of some of the assumptions 
included in the methods underlying this optional tool, we anticipate 
that the resulting isopleth estimates are typically going to be 
overestimates of some degree, which may result in an overestimate of 
potential take by Level A harassment. However, this optional tool 
offers the best way to estimate isopleth distances when more 
sophisticated modeling methods are not available or practical. For 
stationary sources such as pile installation or removal, 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. The isopleths generated by the User 
Spreadsheet used the same TL coefficient as the Level B harassment zone 
calculations (i.e., the practical spreading value of 15). Inputs used 
in the User Spreadsheet (e.g., number of piles per day, duration and/or 
strikes per pile) are presented in Tables 1 and 2, and the resulting 
isopleths are reported below in Table 7. Due to the bathymetry and 
geography of the project areas, sound may not reach the full distance 
of the harassment isopleths in all directions.

                                                Table 7--Level A Harassment and Level B Harassment Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    Level A harassment zone (m)
                                                         --------------------------------------------------------------------------------     Level B
                  Pile type and method                                                                        Phocid          Otariid       harassment
                                                            LF Cetacean     MF Cetacean     HF Cetacean      pinniped        pinniped        zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Steel Pile Impact Installation....................           430.0            15.3           512.2           230.1            16.8           1,000
24-in Steel Pile Vibratory Installation.................             7.9             0.7            11.7             4.8             0.3           5,412
Steel Sheet Pile Vibratory Installation.................            36.8             3.3            54.4            22.4             1.6           4,642
Steel Sheet Pile Vibratory Removal......................             9.6             0.9            14.2             5.8             0.4           4,642
--------------------------------------------------------------------------------------------------------------------------------------------------------

Marine Mammal Occurrence and Take Calculation and Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the 
proposed take incidental to the Corps' pile driving activities. Unless 
otherwise specified, the term ``pile driving'' in this section, and all 
following sections, may refer to either pile installation or removal. 
Unless otherwise specified, the occurrence information described below 
is used to estimate take for both the Year 1 and Year 2 IHAs. NMFS has 
carefully reviewed the Corps' analysis and concludes that it represents 
an appropriate and accurate method for estimating incidental take 
caused by the Corps' activities.
Steller Sea Lion, California Sea Lion, and Harbor Seal
    For Steller sea lions, California sea lions, and harbor seals, the 
numbers of individuals were referenced from WDFW's surveys from 2000-
2014 at the South Jetty for the months of in water work (August through 
October) and averaged to get an estimated daily count (Table 8). While 
animals were surveyed at the prominent haul out site along the South 
Jetty, since the Sand Island pile dikes are very close to the mouth of 
the river and the South Jetty, the Corps assumed each of these 
estimates represent the total number of individuals present in the 
project vicinity. In instances where proposed activities will occur 
over a span of two or more months, the Corps derived potential take 
estimates from the average abundance recorded over the specified 
period. For harbor seals, where abundance was only estimated in July, 
the Corps used that estimate for all projections.

                          Table 8--Pinniped Counts From the South Jetty From 2000-2014
                                                   [WDFW 2014]
----------------------------------------------------------------------------------------------------------------
                                                                    Steller sea   California sea
                                                                       lion            lion         Harbor seal
----------------------------------------------------------------------------------------------------------------
August..........................................................             324             115              57
Average August-September........................................             267             182              57
September.......................................................             209             249              57
October.........................................................             384             508              57
Average (all months)............................................             306             291              57
----------------------------------------------------------------------------------------------------------------


[[Page 39494]]

    To calculate the total estimated takes by Level B harassment, the 
Corps multiplied the estimated days of activity within each month (or 
total across months) by the associated monthly (or average across 
months) count of each species (Table 9).

                                           Table 9--Estimated Take of Steller Sea Lions, California Sea Lions, and Harbor Seals by Level B Harassment
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                    Steller sea
                                                                                   Days of pile     Steller sea        lion       California sea  California sea    Harbor seal     Harbor seal
                Project element                             Month(s)                driving in     lion average     calculated     lion average   lion calculate   average count    calculated
                                                                                     month(s)          count           take            count           take                            take
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Year 1:
    Pile Dike 6.37............................  August-September................              56             267          14,952             182          10,192              57           3,192
    MOF.......................................  October.........................              11             384           4,224             508           5,588              57             627
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
        Total takes by Level B harassment.......................................................................          19,176          Total:          15,780          Total:           3,819
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Year 2:
    Pile Dike 6.37............................  August..........................              24             324           7,776             115           2,760              57           1,368
    Pile Dike 5.15............................  August through October..........              71             306          21,726             291          20,661              57           4,047
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
        Total takes by Level B harassment.......................................................................          29,502          Total:          23,421          Total:           5,415
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

    Based on the relative proportion of the area expected to be 
ensonified above the Level A harassment threshold for phocid pinnipeds 
from impact pile driving of 24-in steel pipe piles (approximately 0.23 
square kilometers (km\2\)) to the area ensonified above the Level B 
harassment threshold (up to 94 km\2\ for vibratory installation of 24-
in steel pipe piles), the Corps estimated that of the total number of 
harbor seals that may be located within the greater Level B harassment 
zone, no more than 1 percent would approach the pile driving activities 
closer and enter the smaller Level A harassment zone (231 m). Thus the 
Corps assumes that 1 percent of the total estimated takes of harbor 
seals (3,819 individuals in Year 1 and 5,415 individuals in Year 2; see 
Table 9) would be by Level A harassment. Therefore, the Corps has 
requested, and NMFS is proposing to authorize, 38 takes of harbor seals 
by Level A harassment and 3,781 takes by Level B harassment in Year 1 
and 54 takes of harbor seals by Level A harassment and 5,361 takes by 
Level B harassment in Year 2 (Table 10).
    The largest Level A harassment zone for otariid pinnipeds is 16.8 
m. The Corps would be required to enforce a minimum shutdown zone of 25 
m for these species. At that close range, the Corps would be able to 
detect California sea lions and Steller sea lions and implement the 
required shutdown measures before any sea lions could enter the Level A 
harassment zone. Therefore, no takes of California sea lions or Steller 
sea lions by Level A harassment are requested or proposed to be 
authorized.
Humpback Whale
    Humpback whales have been observed in the immediate vicinity of the 
project area in recent years. Humpbacks have been arriving in the lower 
Columbia estuary as early as mid-June and have been observed as late as 
mid-November with a peak of abundance coinciding with the peak 
abundance of forage fish in mid-summer. No surveys were located for the 
project area, but it is assumed that they could be present during pile 
driving activities. Given the higher observed abundances in summer, the 
Corps assumes up to two individuals per month could enter the Level B 
harassment zone during pile driving activities each year, for a total 
of 6 takes of humpback whales by Level B harassment in each year (Table 
10).
    The largest Level A harassment zone for low-frequency cetaceans for 
any pile type or method is 430 m. During impact pile driving, the Corps 
would be required to implement a shutdown zone equivalent to the Level 
A harassment zone for low-frequency cetaceans. Given the visibility of 
humpback whales, the Corps would be able to detect humpback whales and 
shut down pile driving before any humpbacks could enter the Level A 
harassment zone. Therefore, no take of humpback whales by Level A 
harassment is requested or proposed to be authorized.
Transient Killer Whale
    Killer whales were not detected in fall and winter aerial surveys 
off the Oregon coast documented in Adams et al. (2014). Aerial seabird 
marine mammal surveys observed zero killer whales in January 2011, zero 
in February 2012, and 10 in September 2012 within an approximately 
1,500 km2 range near the MCR (Adams 2014). While a rare occurrence, a 
pod of transient killer whales were detected near the Astoria Bridge in 
May of 2018 (Frankowicz 2018). There have been no confirmed sightings 
of southern resident killer whales entering the project area. The Corps 
estimates that no more than 2 transient killer whales per year could be 
near the mouth of the Columbia River during proposed work and taken by 
Level B harassment (Table 10).
    The largest Level A harassment zone for mid-frequency cetaceans for 
any pile type or method is 15.3 m. The Corps would be required to 
implement a minimum 25 m shutdown zone for mid-frequency cetaceans. 
Given the visibility of killer whales, at that close range, the Corps 
would be able to detect transient killer whales and shut down pile 
driving before any killer whales could enter the Level A harassment 
zone. Therefore, no take of transient killer whales by Level A 
harassment is requested or proposed to be authorized.
Harbor Porpoise
    Harbor porpoises are regularly observed in the oceanward waters 
adjacent to the project area and are known to occur year-round. Their 
nearshore abundance peaks with anchovy presence, which is generally 
June through October. There was one recorded sighting of a harbor 
porpoise in the project area east of the jetties in the Sept-Nov 
timeframe (OBIS-SEAMAP 2019). Therefore, it is feasible that animals 
could be present during pile driving activities. During monitoring for 
pile driving at the Columbia River Jetty System, over the course of a 
5-day monitoring period, observers detected 5 harbor porpoises (Grette 
Associates 2016). Given the potential for harbor porpoise to travel in 
pairs, the Corps estimates that one pair of harbor porpoises per day 
may enter the Level B harassment zone per day of pile driving (67 days 
in Year 1 and 95

[[Page 39495]]

days in Year 2) for a total of 134 harbor porpoises taken in Year 1 and 
190 taken in Year 2.
    For impact installation of 24-in steel pipe piles, the Level A 
harassment zone for high-frequency cetaceans is 512 m. Although the 
Corps would be required to implement a shutdown zone of 515 m during 
this activity (see Proposed Mitigation), due to the cryptic nature and 
lower detectability of harbor porpoises at large distances, the Corps 
anticipates that up to 16 of the harbor porpoises (2 per week over the 
course of 8 weeks of impact pile driving) that enter the Level B zone 
in Year 1 could approach the project site closer and potentially enter 
the Level A harassment zone undetected during impact installation. 
Similarly, the Corps estimates that up to 27 of the harbor porpoises 
that enter the Level B harassment zone in Year 2 (2 per week over the 
course of 13.5 weeks of impact pile driving) could approach the project 
site closer and potentially enter the Level A harassment zone 
undetected during impact installation. These takes by Level A 
harassment could occur as one group in one day or single animals over 
multiple days. In total, the Corps has requested take of 134 harbor 
porpoises in Year 1 (118 takes by Level B harassment and 16 takes by 
Level A harassment) and 190 harbor porpoises in Year 2 (163 takes by 
Level B harassment and 27 takes by Level A harassment) (Table 10).
Northern Elephant Seal
    Northern elephant seals have been observed near the mouth of the 
Columbia River, but there are no known haulout locations for northern 
elephant seals in the project vicinity. Given the rarity of sightings 
in and around the Columbia River, the Corps estimates that no more than 
2 northern elephant seals per month may enter the project area and be 
taken by Level B harassment each year, for a total of 6 takes by Level 
B harassment in Year 1 and 6 takes by Level B harassment in Year 2 
(Table 10).
    The largest Level A harassment zone (230 m) occurs during impact 
installation of 24-in steel pipe piles. It is unlikely that northern 
elephant seals would be found within this zone, and even more unlikely 
that northern elephant seals would be found within the Level A 
harassment zones for vibratory pile driving of any pile size (less than 
23 m for all pile types). However, even if northern elephant seals were 
encountered in the project areas, at that close range, the Corps would 
be able to detect them and implement the required shutdown measures 
before any northern elephant seals could enter the Level A harassment 
zones. Therefore, no take of northern elephant seals by Level A 
harassment is requested or proposed to be authorized.

         Table 10--Proposed Take of Marine Mammals by Level A and Level B Harassment by Year, by Species and Stock and Percent of Take by Stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                             Proposed take   Proposed take
                  Species                     by Level A      by Level B    Total proposed              Stock                  Stock        Percent of
                                              harassment      harassment         take                                        abundance         stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Year 1:
    Humpback whale........................               0               6               6  California/Oregon/Washington           2,900            0.21
    Killer whale..........................               0               2               2  West Coast Transient........             349            0.57
    Harbor porpoise.......................              16             118             134  Northern Oregon/Washington            21,487            0.60
                                                                                             Coast.
    California sea lion...................               0          15,780          15,780  U.S.........................         257,606            6.13
    Steller sea lion......................               0          19,176          19,176  Eastern.....................          52,932           36.23
    Harbor seal...........................              38           3,781           3,819  Oregon/Washington Coast.....          24,732           15.44
    Northern elephant seal................               0               6               6  California Breeding.........         179,000           0.003
Year 2:
    Humpback whale........................               0               6               6  California/Oregon/Washington           2,900            0.21
    Killer whale..........................               0               2               2  West Coast Transient........             349            0.57
    Harbor porpoise.......................              27             163             190  Northern Oregon/Washington            21,487            0.88
                                                                                             Coast.
    California sea lion...................               0          23,421          23,421  U.S.........................         257,606            9.09
    Steller sea lion......................               0          29,502          29,502  Eastern.....................          52,932           55.74
    Harbor seal...........................              54           5,361           5,415  Oregon/Washington Coast.....          24,732           21.89
    Northern elephant seal................               0               6               6  California Breeding.........         179,000           0.003
--------------------------------------------------------------------------------------------------------------------------------------------------------

Proposed Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks, and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, NMFS 
considers two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned), and;
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost and impact on 
operations.

Time Restrictions

    The Corps has provided in its description of the project that pile 
driving would occur only during daylight hours (no sooner than 30 
minutes after sunrise through no later than 30 minutes before sunset), 
when visual monitoring of marine mammals can be conducted. In addition, 
to minimize impacts to ESA-listed fish species, all in-water 
construction would

[[Page 39496]]

be limited to the months of August through November.

Shutdown Zones

    Before the commencement of in-water construction activities, the 
Corps would establish shutdown zones for all activities. The purpose of 
a shutdown zone is generally to define an area within which shutdown of 
the activity would occur upon sighting of a marine mammal (or in 
anticipation of an animal entering the defined area). Pile driving 
would also not commence until all marine mammals are clear of their 
respective shutdown zones. Shutdown zones are meant to encompass the 
Level A harassment zones and therefore would vary based on the activity 
type and marine mammal hearing group (Table 11). At minimum, the 
shutdown zone for all hearing groups and all activities is 25 m. For 
in-water heavy machinery work other than pile driving (e.g., standard 
barges, etc.), if a marine mammal comes within 25 m, operations would 
cease and vessels would reduce speed to the minimum level required to 
maintain steerage and safe working conditions. This type of work could 
include, for example, the movement of the barge to the pile location or 
positioning of the pile on the substrate via a crane.
    The Corps would also establish shutdown zones for all marine 
mammals for which take has not been authorized or for which incidental 
take has been authorized but the authorized number of takes has been 
met. These zones are equivalent to the Level B harassment zones for 
each activity (see Table 11).

                                                                Table 11--Shutdown Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Shutdown zones by hearing group (m)                       Shutdown zones
                                                         --------------------------------------------------------------------------------       for
                  Pile type and method                                                                        Phocid          Otariid      unauthorized
                                                            LF cetacean     MF cetacean     HF cetacean      pinniped        pinniped       species (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Steel pipe Pile Impact Installation...............             430              25             515          \a\ 50              25           1,000
24-in Steel pipe pile Vibratory Installation............              25              25              25              25              25           5,412
24-in Steel Sheet Pile Vibratory Installation \b\.......              40              25              55              25              25           4,642
24-in Steel Sheet Pile Vibratory Removal \b\............              25              25              25              25              25           4,642
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ 50 m is for harbor seals, shutdown zone for northern elephant seals is 235 m.
\b\ Vibratory installation and removal of 24-in steel sheet piles only applicable in Year 1. No sheet piles will be installed or removed in Year 2.

Protected Species Observers

    The placement of protected species observers (PSOs) during all pile 
driving activities (described in the Proposed Monitoring and Reporting 
section) would ensure that the entire shutdown zone is visible. Should 
environmental conditions deteriorate such that the entire shutdown zone 
would not be visible (e.g., fog, heavy rain), pile driving would be 
delayed until the PSO is confident marine mammals within the shutdown 
zone could be detected.
Monitoring for Level A and Level B Harassment
    PSOs would monitor the Level B harassment zones to the extent 
practicable, and all of the Level A harassment zones. Monitoring zones 
provide utility for observing by establishing monitoring protocols for 
areas adjacent to the shutdown zones. Monitoring zones enable observers 
to be aware of and communicate the presence of marine mammals in the 
project areas outside the shutdown zones and thus prepare for a 
potential cessation of activity should the animal enter the shutdown 
zone.
Pre-Activity Monitoring
    Prior to the start of daily in-water construction activity, or 
whenever a break in pile driving of 30 minutes or longer occurs, PSOs 
would observe the shutdown and monitoring zones for a period of 30 
minutes. The shutdown zone would be considered cleared when a marine 
mammal has not been observed within the zone for that 30-minute period. 
If a marine mammal is observed within the shutdown zones listed in 
Tables 12 and 13, pile driving activity would be delayed or halted. If 
pile driving is delayed or halted due to the presence of a marine 
mammal, the activity would not commence or resume until either the 
animal has voluntarily exited and been visually confirmed beyond the 
shutdown zones or 15 minutes have passed without re-detection of the 
animal. When a marine mammal for which Level B harassment take is 
authorized is present in the Level B harassment zone, activities would 
begin and Level B harassment take would be recorded. If work ceases for 
more than 30 minutes, the pre-activity monitoring of the shutdown zones 
would commence. A determination that the shutdown zone is clear must be 
made during a period of good visibility (i.e., the entire shutdown zone 
and surrounding waters must be visible to the naked eye).

Soft Start

    Soft-start procedures are used to provide additional protection to 
marine mammals by providing warning and/or giving marine mammals a 
chance to leave the area prior to the hammer operating at full 
capacity. For impact pile driving, contractors would be required to 
provide an initial set of three strikes from the hammer at reduced 
energy, followed by a 30-second waiting period, then two subsequent 
reduced-energy strike sets. Soft start would be implemented at the 
start of each day's impact pile driving and at any time following 
cessation of impact pile driving for a period of 30 minutes or longer.
    Based on our evaluation of the Corps' proposed measures, as well as 
other measures considered by NMFS, 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

[[Page 39497]]

understanding of one or more of the following:
    <bullet> Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
    <bullet> Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
    <bullet> Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
    <bullet> How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
    <bullet> Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and,
    <bullet> Mitigation and monitoring effectiveness.

Visual Monitoring

    Marine mammal monitoring during pile driving activities would be 
conducted by PSOs meeting NMFS' standards and in a manner consistent 
with the following:
    <bullet> Independent PSOs (i.e., not construction personnel) who 
have no other assigned tasks during monitoring periods would be used;
    <bullet> At least one PSO would have prior experience performing 
the duties of a PSO during construction activity pursuant to a NMFS-
issued incidental take authorization;
    <bullet> Other PSOs may substitute education (degree in biological 
science or related field) or training for experience; and
    <bullet> Where a team of three or more PSOs is required, a lead 
observer or monitoring coordinator would be designated. The lead 
observer would be required to have prior experience working as a marine 
mammal observer during construction.
    PSOs would have the following additional qualifications:
    <bullet> Ability to conduct field observations and collect data 
according to assigned protocols;
    <bullet> Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
    <bullet> Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    <bullet> Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and
    <bullet> Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    The Corps would have at least 2 PSOs stationed in the project area 
to monitor during all pile driving activities. One PSO would be 
positioned at the work site on the construction barge to observe Level 
A harassment and shutdown zones. At least one PSO would monitor from a 
boat to ensure full visual coverage of the Level B harassment zone(s) 
and alert construction crews of marine mammals entering the Level B 
harassment zone and/or approaching the Level A harassment zones. 
Additional PSOs may be employed during periods of low or obstructed 
visibility to ensure the entirety of the shutdown zones are monitored.
    Monitoring would be conducted 30 minutes before, during, and 30 
minutes after all in water construction activities. In addition, 
observers would record all incidents of marine mammal occurrence, 
regardless of distance from activity, and would document any behavioral 
reactions in concert with distance from piles being driven or removed. 
Pile driving activities include the time to install or remove a single 
pile or series of piles, as long as the time elapsed between uses of 
the pile driving equipment is no more than 30 minutes.

Reporting

    A draft marine mammal monitoring report would be submitted to NMFS 
within 90 days after the completion of pile driving activities, or 60 
days prior to a requested date of issuance of any future IHAs for the 
project, or other projects at the same location, whichever comes first. 
The marine mammal report would include an overall description of work 
completed, a narrative regarding marine mammal sightings, and 
associated PSO data sheets. Specifically, the report would include:
    <bullet> Dates and times (begin and end) of all marine mammal 
monitoring;
    <bullet> Construction activities occurring during each daily 
observation period, including: (a) How many and what type of piles were 
driven or removed and the method (i.e., impact or vibratory); and (b) 
the total duration of time for each pile (vibratory driving) number of 
strikes for each pile (impact driving);
    <bullet> PSO locations during marine mammal monitoring; and
    <bullet> Environmental conditions during monitoring periods (at 
beginning and end of PSO shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance.
    For each observation of a marine mammal, the following would be 
reported:
    <bullet> Name of PSO who sighted the animal(s) and PSO location and 
activity at time of sighting;
    <bullet> Time of sighting;
    <bullet> Identification of the animal(s) (e.g., genus/species, 
lowest possible taxonomic level, or unidentified), PSO confidence in 
identification, and the composition of the group if there is a mix of 
species;
    <bullet> Distance and location of each observed marine mammal 
relative to the pile being driven or hole being drilled for each 
sighting;
    <bullet> Estimated number of animals (min/max/best estimate);
    <bullet> Estimated number of animals by cohort (adults, juveniles, 
neonates, group composition, etc.);
    <bullet> Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as feeding or traveling), including an 
assessment of behavioral responses thought to have resulted from the 
activity (e.g., no response or changes in behavioral state such as 
ceasing feeding, changing direction, flushing, or breaching);
    <bullet> Number of marine mammals detected within the harassment 
zones, by species; and
    <bullet> Detailed information about implementation of any 
mitigation (e.g., shutdowns and delays), a description of specified 
actions that ensued, and resulting changes in behavior of the 
animal(s), if any.
    If no comments are received from NMFS within 30 days, the draft 
reports would constitute the final reports. If comments are received, a 
final report addressing NMFS' comments would be required to be 
submitted within 30 days after receipt of comments. All PSO datasheets 
and/or raw sighting data

[[Page 39498]]

would be submitted with the draft marine mammal report.
    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the Corps would report the 
incident to the Office of Protected Resources (OPR) 
(<a href="/cdn-cgi/l/email-protection#3a6a6814736e6a14775554534e554853545d685f4a55484e497a54555b5b145d554c"><span class="__cf_email__" data-cfemail="f8a8aad6b1aca8d6b59796918c978a91969faa9d88978a8c8bb896979999d69f978e">[email protected]</span></a>), NMFS and to the West Coast Region 
(WCR) regional stranding coordinator as soon as feasible. If the death 
or injury was clearly caused by the specified activity, the Corps would 
immediately cease the specified activities until NMFS is able to review 
the circumstances of the incident and determine what, if any, 
additional measures are appropriate to ensure compliance with the terms 
of the IHAs. The Corps would not resume their activities until notified 
by NMFS.
    The report would include the following information:
    1. Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    2. Species identification (if known) or description of the 
animal(s) involved;
    3. Condition of the animal(s) (including carcass condition if the 
animal is dead);
    4. Observed behaviors of the animal(s), if alive;
    5. If available, photographs or video footage of the animal(s); and
    6. General circumstances under which the animal was discovered.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any impacts or responses (e.g., intensity, duration), 
the context of any impacts or responses (e.g., critical reproductive 
time or location, foraging impacts affecting energetics), as well as 
effects on habitat, and the likely effectiveness of the mitigation. We 
also assess the number, intensity, and context of estimated takes by 
evaluating this information relative to population status. Consistent 
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338; 
September 29, 1989), the impacts from other past and ongoing 
anthropogenic activities are incorporated into this analysis via their 
impacts on the baseline (e.g., as reflected in the regulatory status of 
the species, population size and growth rate where known, ongoing 
sources of human-caused mortality, or ambient noise levels).
    To avoid repetition, the discussion of our analysis applies to all 
species listed in Table 10, 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. We 
note, though, that there are far fewer estimated takes of cetaceans 
than pinnipeds, and some additional pinniped-specific analysis is 
included.
    Pile driving activities associated with the Sand Island Pile Dikes 
Repairs Project have the potential to disturb or displace marine 
mammals. Specifically, the project activities may result in take, in 
the form of Level A and Level B harassment, from underwater sounds 
generated from pile driving. Potential takes could occur if individuals 
are present in the ensonified zone when these activities are underway.
    The takes from Level A and Level B harassment would be due to 
potential behavioral disturbance, TTS, and PTS. No serious injury or 
mortality is anticipated given the nature of the activities and 
measures designed to minimize the possibility of injury to marine 
mammals. The potential for harassment is minimized through the 
construction method and the implementation of the planned mitigation 
measures (see Proposed Mitigation section).
    In both years, take by Level A harassment is proposed for 2 species 
(harbor seals and harbor porpoise) to account for the possibility that 
an animal could enter a Level A harassment zone prior to detection, and 
remain within that zone for a duration long enough to incur PTS before 
being observed and the Corps shutting down pile driving activity. Any 
take by Level A harassment is expected to arise from, at most, a small 
degree of PTS, i.e., minor degradation of hearing capabilities within 
regions of hearing that align most completely with the energy produced 
by impact pile driving (i.e. the low-frequency region below 2 kHz), not 
severe hearing impairment or impairment within the ranges of greatest 
hearing sensitivity. Animals would need to be exposed to higher levels 
and/or longer duration than are expected to occur here in order to 
incur any more than a small degree of PTS.
    Additionally, the amount of authorized take by Level A harassment 
is very low for all marine mammal stocks and species. For both IHAs, 
for 5 of 7 affected stocks, NMFS anticipates and proposes to authorize 
no Level A harassment take over the duration of the Corps' planned 
activities; for the other 2 stocks, NMFS authorizes no more than 54 
takes by Level A harassment in any year. If hearing impairment occurs, 
it is most likely that the affected animal would lose only a few 
decibels in its hearing sensitivity. These takes of individuals by 
Level A harassment (i.e., a small degree of PTS) are not expected to 
accrue in a manner that would affect the reproductive success or 
survival of any individuals, much less result in adverse impacts on the 
species or stock.
    As described above, NMFS expects that marine mammals would likely 
move away from an aversive stimulus, especially at levels that would be 
expected to result in PTS, given sufficient notice through use of soft 
start. The Corps would also shut down pile driving activities if marine 
mammals approach within hearing group-specific zones that encompass the 
Level A harassment zones (see Table 11) further minimizing the 
likelihood and degree of PTS that would be incurred. Even absent 
mitigation, no serious injury or mortality from construction activities 
is anticipated or authorized.
    Effects on individuals that are taken by Level B harassment in the 
form of behavioral disruption, on the basis of reports in the 
literature as well as monitoring from other similar activities, 
including the Sand Island Pile Dike System Test Piles Project conducted 
by the Corps in preparation for the proposed Sand Island Pile Dikes 
Repairs Project (84 FR 61026; November 12, 2019), would likely be 
limited to reactions such as avoidance, increased swimming speeds, 
increased surfacing time, or decreased foraging (if such activity were 
occurring) (e.g., Thorson and Reyff 2006). Most likely, individuals 
would simply move away from the sound source and temporarily avoid the 
area where pile driving is occurring. If sound produced by project 
activities is sufficiently disturbing, animals are likely to simply 
avoid the area while the activities are occurring, particularly as the 
project is located on a busy waterway at the mouth of the Columbia 
River with high amounts of

[[Page 39499]]

vessel traffic. We expect that any avoidance of the project areas by 
marine mammals would be temporary in nature and that any marine mammals 
that avoid the project areas during construction would not be 
permanently displaced. Short-term avoidance of the project areas and 
energetic impacts of interrupted foraging or other important behaviors 
is unlikely to affect the reproduction or survival of individual marine 
mammals, and the effects of behavioral disturbance on individuals is 
not likely to accrue in a manner that would affect the rates of 
recruitment or survival of any affected stock.
    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. However, 
since the hearing sensitivity of individuals that incur TTS is expected 
to recover completely within minutes to hours, it is unlikely that the 
brief hearing impairment would affect the individual's long-term 
ability to forage and communicate with conspecifics, and would 
therefore not likely impact reproduction or survival of any individual 
marine mammal, let alone adversely affect rates of recruitment or 
survival of the species or stock.
    The project is also not expected to have significant adverse 
effects on affected marine mammals' habitats. The project activities 
will not modify existing marine mammal habitat for a significant amount 
of time. The activities may cause some fish to leave the area of 
disturbance, thus temporarily impacting marine mammals' foraging 
opportunities in a limited portion of the foraging range; but, because 
of the short duration of the activities and the relatively small area 
of the habitat that may be affected (with no known particular 
importance to marine mammals), the impacts to marine mammal habitat are 
not expected to cause significant or long-term negative consequences. 
The shores along the Columbia River are occasionally used by harbor 
seals for pupping, but the Corps' proposed activities would occur 
outside of the harbor seal pupping season. There are no known important 
areas for other marine mammals, such as feeding or pupping areas.
    For all species and stocks, and in both years, take would occur 
within a limited, relatively confined area (the mouth of the Columbia 
River) of the stock's range. Given the availability of suitable habitat 
nearby, any displacement of marine mammals from the project areas is 
not expected to affect marine mammals' fitness, survival, and 
reproduction due to the limited geographic area that would be affected 
in comparison to the much larger habitat for marine mammals within the 
lower Columbia River and immediately outside the river along the Oregon 
and Washington coasts. Level A harassment and Level B harassment would 
be reduced to the level of least practicable adverse impact to the 
marine mammal species or stocks and their habitat through use of 
mitigation measures described herein.
    Some individual marine mammals in the project areas may be present 
and be subject to repeated exposure to sound from pile driving on 
multiple days. However, pile driving is not expected to occur on every 
day of the in-water work window, and these individuals would likely 
return to normal behavior during gaps in pile driving activity within 
each day of construction and in between work days. As discussed above, 
there is similar foraging and haulout habitat available for marine 
mammals within and outside of the Columbia River along the Washington 
and Oregon coasts, outside of the project area, where individuals could 
temporarily relocate during construction activities to reduce exposure 
to elevated sound levels from the project. Therefore, any behavioral 
effects of repeated or long duration exposures are not expected to 
negatively affect survival or reproductive success of any individuals. 
Thus, even repeated Level B harassment of some small subset of an 
overall stock is unlikely to result in any effects on rates of 
reproduction and survival of the stock.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect any of the species 
or stocks through effects on annual rates of recruitment or survival:
    <bullet> No mortality or serious injury is anticipated or proposed 
to be authorized for either year;
    <bullet> In both years, Level A harassment is not anticipated or 
authorized for 5 of the 7 species. For the other 2 species (1 high-
frequency cetacean and 1 phocid pinniped), the amount of Level A 
harassment is low and would be in the form of a slight degree of PTS in 
limited low frequency ranges (<2 kHz) which are not the most sensitive 
primary hearing ranges for these species and would not interfere with 
conspecific communication or echolocation;
    <bullet> For both years, Level B harassment would be in the form of 
behavioral disturbance, primarily resulting in avoidance of the project 
areas around where impact or vibratory pile driving is occurring, and 
some low-level TTS that may limit the detection of acoustic cues for 
relatively brief amounts of time in relatively confined footprints of 
the activities;
    <bullet> Nearby areas of similar habitat value (e.g., foraging and 
haulout habitats) within and outside the lower Columbia River are 
available for marine mammals that may temporarily vacate the project 
areas during construction activities for both projects;
    <bullet> Effects on species that serve as prey for marine mammals 
from the activities are expected to be short-term and, therefore, any 
associated impacts on marine mammal feeding are not expected to result 
in significant or long-term consequences for individuals, or to accrue 
to adverse impacts on their populations from either project;
    <bullet> The ensonified areas in both years are very small relative 
to the overall habitat ranges of all species and stocks, and will not 
adversely affect ESA-designated critical habitat for any species or any 
areas of known biological importance;
    <bullet> The lack of anticipated significant or long-term negative 
effects to marine mammal habitat from either project;
    <bullet> The efficacy of the mitigation measures in reducing the 
effects of the specified activities on all species and stocks for both 
projects;
    <bullet> The enhanced mitigation measures (e.g., shutdown zones 
equivalent to the Level B harassment zones) to eliminate the potential 
for any take of unauthorized species; and
    <bullet> Monitoring reports from similar work in the lower Columbia 
River, including previous work at the Sand Island Pile Dikes, that have 
documented little to no behavioral effect on individuals of the same 
species that could be impacted by the specified activities from both 
projects, suggesting the degree/intensity of behavioral harassment 
would be minimal.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from the proposed activities in Year 1 will have a 
negligible impact on all affected marine mammal species or stocks. NMFS 
also preliminarily finds that the total marine mammal take from the 
proposed activities in Year 2 will have a negligible impact on all 
affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized

[[Page 39500]]

under sections 101(a)(5)(A) and (D) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers and so, in practice, where estimated numbers are 
available, NMFS compares the number of individuals taken to the most 
appropriate estimation of abundance of the relevant species or stock in 
our determination of whether an authorization is limited to small 
numbers of marine mammals. When the predicted number of individuals to 
be taken is fewer than one-third of the species or stock abundance, the 
take is considered to be of small numbers. Additionally, other 
qualitative factors may be considered in the analysis, such as the 
temporal or spatial scale of the activities.
    For all species other than Steller sea lions, the proposed take in 
each year is below one third of the population for all marine mammal 
stocks (Table 10). In Year 1 and Year 2, the proposed take of Steller 
sea lions, as a proportion of the stock abundance is 36.23 percent and 
55.74 percent, respectively, if all takes are assumed to occur for 
unique individuals. In reality, it is unlikely that all takes would 
occur to different individuals. The project area represents a small 
portion of the stock's overall range (from Alaska to California (Muto 
et al., 2019)) and based on observations at other Steller sea lion 
haulouts, it is reasonable to expect individual animals to be present 
at the haulout and in the water nearby on multiple days during the 
activities. Therefore, it is more likely that there will be multiple 
takes of a smaller number of individuals within the project area, such 
that the number of individuals taken would be less than one third of 
the population.
    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 in Year 1. NMFS also 
preliminarily finds that small numbers of marine mammals would be taken 
relative to the population size of the affected species or stocks in 
Year 2.

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, in this case with the West Coast 
Regional Office.
    NMFS is proposing to authorize take of humpback whales from the 
Mexico and Central America DPSs, which are listed under the ESA. The 
Permits and Conservation Division has requested initiation of section 7 
consultation with the West Coast Region for the issuance of this IHA. 
NMFS will conclude the ESA consultation prior to reaching a 
determination regarding the proposed issuance of the authorization.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue two sequential IHAs to the Corps for conducting the Sand Island 
Pile Dikes Repairs Project in the lower Columbia River, beginning in 
August 2023, with the previously mentioned mitigation, monitoring, and 
reporting requirements incorporated. A draft of the proposed IHAs 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 2 proposed sequential IHAs for the 
proposed Sand Island Pile Dikes Repairs Project. We also request 
comment on the potential renewal of these proposed IHAs 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 these IHAs or subsequent renewal IHAs.
    On a case-by-case basis, NMFS may issue a one-time, one-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 
Activities section of this notice is planned or (2) the activities as 
described in the Description of Proposed Activities section of this 
notice would not be completed by the time the IHA expires and a renewal 
would allow for completion of the activities beyond that described in 
the Dates and Duration section of this notice, provided all of the 
following conditions are met:
    <bullet> A request for renewal is received no later than 60 days 
prior to the needed renewal IHA effective date (recognizing that the 
renewal IHA expiration date cannot extend beyond one year from 
expiration of the initial IHA).
    <bullet> The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
requested renewal IHA are identical to the activities analyzed under 
the initial IHA, are a subset of the activities, or include changes so 
minor (e.g., reduction in pile size) that the changes do not affect the 
previous analyses, mitigation and monitoring requirements, or take 
estimates (with the exception of reducing the type or amount of take).
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized.
    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 28, 2022.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2022-14138 Filed 6-30-22; 8:45 am]
BILLING CODE 3510-22-P


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