Notice2022-14138
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Sand Island Pile Dikes Repairs in the Columbia River
Primary source
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Published
July 1, 2022
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
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.
Full Text
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<title>Federal Register, Volume 87 Issue 126 (Friday, July 1, 2022)</title>
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[Federal Register Volume 87, Number 126 (Friday, July 1, 2022)]
[Notices]
[Pages 39481-39500]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[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
<a href="http://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act">www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</a> without change. All personal identifying
information (e.g., name, address) voluntarily submitted by the
commenter may be publicly accessible. Do not submit confidential
business information or otherwise sensitive or protected information.
FOR FURTHER INFORMATION CONTACT: 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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</a>. In case of problems
accessing these documents, please call the contact listed 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
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\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; <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and
more general information about these species (e.g., physical and
behavioral descriptions) may be found on NMFS' website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports">https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports</a>).
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\
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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).
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\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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region</a>. CV is coefficient of variation; Nmin is the minimum
estimate of stock abundance.
\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:
<a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</a>.
Request for Public Comments
We request comment on our analyses, the proposed authorization, and
any other aspect of this notice of 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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This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.