Notice2022-10938
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the U.S. Coast Guard's Floating Dock Extension Project at Base Ketchikan, Alaska
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
May 20, 2022
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from the United States Coast Guard (USCG) for authorization to take marine mammals incidental to the floating dock extension construction project in Ketchikan, Alaska. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue an incidental harassment authorization (IHA) to incidentally take marine mammals during the specified activities. NMFS is also requesting comments on a possible one-time, one-year renewal that could be issued under certain circumstances and if all requirements are met, as described in Request for Public Comments at the end of this notice. NMFS will consider public comments prior to making any final decision on the issuance of the requested MMPA authorizations and agency responses will be summarized in the final notice of our decision.
Full Text
<html>
<head>
<title>Federal Register, Volume 87 Issue 98 (Friday, May 20, 2022)</title>
</head>
<body><pre>
[Federal Register Volume 87, Number 98 (Friday, May 20, 2022)]
[Notices]
[Pages 30894-30915]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2022-10938]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XB747]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the U.S. Coast Guard's Floating
Dock Extension Project at Base Ketchikan, Alaska
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization; request
for comments on proposed authorization and possible renewal.
-----------------------------------------------------------------------
SUMMARY: NMFS has received a request from the United States Coast Guard
(USCG) for authorization to take marine mammals incidental to the
floating dock extension construction project in Ketchikan, Alaska.
Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting
comments on its proposal to issue an incidental harassment
authorization (IHA) to incidentally take marine mammals during the
specified activities. NMFS is also requesting comments on a possible
one-time, one-year renewal that could be issued under certain
circumstances and if all requirements are met, as described in Request
for Public Comments at the end of this notice. NMFS will consider
public comments prior to making any final decision on the issuance of
the requested MMPA authorizations and agency responses will be
summarized in the final notice of our decision.
DATES: Comments and information must be received no later than June 21,
2022.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service. Written comments should be submitted
via email to <a href="/cdn-cgi/l/email-protection#8dc4d9dda3cee2ffeee2ffece3cde3e2ececa3eae2fb"><span class="__cf_email__" data-cfemail="c0899490ee83afb2a3afb2a1ae80aeafa1a1eea7afb6">[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: Kim Corcoran, 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/permit/incidental-take-authorizations-under-marine-mammal-protection-act">https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</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 issued or, if the taking is limited to harassment, a notice of a
proposed incidental take authorization may be 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
[[Page 30895]]
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 IHA
qualifies to be categorically excluded from further NEPA review. We
will review all comments submitted in response to this notice prior to
concluding our NEPA process or making a final decision on the IHA
request.
Summary of Request
On March 9th, 2021, NMFS received a request from the USCG for an
IHA to take marine mammals incidental to the construction of the
floating dock extension at Base Ketchikan, Alaska. Following NMFS'
review of the request, USCG provided additional information on July 22,
2021, and again on March 7, 2022. The application was deemed adequate
and complete on the latter date. USCG's request is for take of ten
species of marine mammals by Level B harassment and, for a subset of
three species, by Level A harassment. Neither USCG nor NMFS expects
serious injury or mortality to result from this activity and,
therefore, an IHA is appropriate.
Description of Proposed Activity
Overview
The USCG requests an Incidental Harassment Authorization (IHA) for
activities associated with the construction of the Floating Dock
Extension Project in the Tongass Narrows at Coast Guard Base Ketchikan
(Base Ketchikan) in Ketchikan, Alaska. The proposed project will cover
a 12-month window during which approximately 30 days of pile-
installation activity will occur. The project involves the installation
of ten, 24-inch steel guide piles for a third floating dock section.
Three different installation methods will be used including the Down-
the-Hole (DTH) system to create rock sockets for new piles, vibratory
installation of piles, and final pile proofing with a limited use of
impact pile driving. Sounds resulting from pile installation and
drilling may result in the incidental take of marine mammals by Level A
and Level B harassment in the form of auditory injury or behavioral
harassment.
Dates and Duration
The proposed IHA would be effective from July 1, 2022 through June
30, 2023. The total expected work duration would be 15 construction
days (5 days of DTH, 5 days of vibratory pile installation, and 5 days
of impact pile driving) with an additional 15 day buffer to account for
days where work is paused (e.g., inclement weather), for a total work
window of 30 days. The USCG plans to conduct all work during daylight
hours.
Specific Geographic Region
The proposed activity will occur in the Tongass Narrows at Base
Ketchikan in Ketchikan, Alaska (Figure 1). Base Ketchikan is located on
the southwestern end of Revillagigedo Island, approximately 235 miles
south of Juneau and 90 miles north of Prince Rupert, British Columbia.
The Base is about 1 mile south of downtown Ketchikan, on the industrial
limits of the city, and on the East Channel of the Tongass Narrows. The
waters of the Tongass Narrows are heavily used by the public including
cruise ships, commercial fishing vessels, and private craft and sea
planes, which contribute significantly to the ambient acoustic
environment in the Narrows.
[[Page 30896]]
[GRAPHIC] [TIFF OMITTED] TN20MY22.001
[[Page 30897]]
[GRAPHIC] [TIFF OMITTED] TN20MY22.002
Detailed Description of Specific Activity
USCG plans to install ten steel guide piles for a third floating
dock section at Base Ketchikan to support the homeporting of a third
Fast Response Cutter (FRC) (Figure 2). The piles would be installed
over a period of 30 days, allotting five construction days to each of
the three methods of installation, in addition to 15 additional buffer
days to account for unforeseen interruptions (e.g., inclement weather).
These methods include DTH, vibratory pile installation and impact
driving pile proofing (see Table 1).
The use of DTH will depend on the overburden thickness and bedrock
bottom conditions beneath the proposed floating dock extension (see
Figure 2). If needed, the DTH system will be used to pre-drill sockets
for each guide pile that will be installed. Neighboring projects in the
Tongass Narrows have reported ten feet of overburden requiring 20-foot
deep sockets to be drilled for pile installation. USCG expects
conditions to be similar at the proposed project site. Once rock
sockets are drilled, 24-inch steel piles would be inserted using a
vibratory hammer. An impact pile driver would then be used to proof the
newly installed piles which would then be stabilized using concrete in
the pile socket. Floating stick bar booms will be deployed around the
active work area to provide a complete barrier to floating debris.
Additional actions occurring under the proposed action that are not
anticipated to generate in-water noise resulting in marine mammal
harassment include the removal of the existing wave attenuator
southeast of the proposed floating dock extension (Figure 2). Removal
of the existing wave attenuator will include removal of stockless
anchors vertically off the seafloor and floating the concrete wave
attenuator to a recycling/disposal location. Once the piles are
installed, the floating dock would be placed around the 10 guide piles
followed by ancillary infrastructure (e.g., electricity, water, sewage,
communications) to support the docked cutters. NMFS does not expect,
that these ancillary activities will harm or harass marine mammals and
no incidental takes are expected as a result of these activities.
Therefore, these activities are not discussed further in this document.
[[Page 30898]]
Table 1--Pile Installation Methods and Durations
----------------------------------------------------------------------------------------------------------------
Piles
Installation method Duration/impacts per pile driven/day Estimated days
----------------------------------------------------------------------------------------------------------------
DTH...................................... 60 minutes................. 2 5.
Vibratory pile installation.............. 6 minutes.................. 2 5.
Impact driving pile proofing............. 5 impacts.................. 2 5 (10 strikes).
-----------------------------------------
Total................................ ........................... ........... 15 (30) \1\
----------------------------------------------------------------------------------------------------------------
\1\ The total expected work duration is 15 days with an additional 15 day buffer to account for days where work
is paused (e.g., inclement weather) for a total work window of 30 days.
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. Additional information regarding population
trends and threats may be found in NMFS's Stock Assessment Reports
(SARs; <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and more general
information about these species (e.g., physical and behavioral
descriptions) may be found on NMFS's website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 2 lists all species or stocks for which take is expected and
proposed to be authorized for this action, 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. For taxonomy, we follow Committee on
Taxonomy (2021). 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's SARs). While no
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's 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's U.S. 2021 Draft SARs (e.g., Muto et al., 2021). All values
presented in Table 2 are the most recent available at the time of
publication and are available in the 2021 draft SARs (Muto et al.,
2021). 2020 SARs (Muto et al., 2021) 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 2--Species Likely Impacted by the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
Gray whale...................... Eschrichtius robustus.. Eastern North Pacific -,-,N 26,960 (0.05, 25,849, 801 131
Stock. 2016).
Family Balaenopteridae (rorquals):
Humpback whale.................. Megaptera novaeanglinae Central North Pacific -,-,Y 10,103 (0.3, 7,890, 83 26
Stock. 2006).
Minke whale..................... Balaenoptera Alaska Stock........... -,-,N N/A (N/A, N/A, N/A) UND 0
acutorostrata. \4\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
Killer whale.................... Orca orcinus........... Alaska Resident........ -,-,N 2,347 (N/A, 2347, 24 1
2012).
Northern Resident...... -,-,N 302 (N/A, 302, 2018).. 2.2 0.2
West Coast Transient... -,-,N 349 (N/A, 349, 2018).. 3.5 0.4
Pacific white-sided dolphin..... Lagenorhynchus North Pacific Stock.... -,-,N 26,880 (N/A, N/A,1990) UND 0
obliquidens.
Family Phocoenidae (porpoises):
Dall's porpoise \6\............. Phocoenoides dalli..... Alaska Stock........... -,-,N 15,432 131 37
(0.097,13,110,2015).
Harbor porpoise \7\............. Phocoena phocoena...... Southeast Alaska Stock. -,-,Y 1302 (0.21, 1057, 11 34
2019).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
sea lions):
Steller sea lion................ Eumetopias jubatus..... Eastern Stock.......... -,-,N 43,201 (N/A, 43,201, 2,592 112
2017).
[[Page 30899]]
Family Phocidae (earless seals):
Harbor seal..................... Phoca vituline Clarence Strait Stock.. -,-,N 27,659 (N/A, 24,854, 746 40
richardii. 2015).
Northern Elephant seal.......... Mirounga angustirostris California Breeding -,-,N 187,386 (N/A, 85,369, 5,122 5.3
Stock. 2013).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports</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 M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
\4\ No population estimates have been made for the number of minke whales in the entire North Pacific. Some information is available on the numbers of
minke whales on some areas of Alaska, but in the 2009, 2013 and 2015 offshore surveys, so few minke whales were seen during the surveys that a
population estimate for the species in this area could not be determined (Rone et al., 2017). Therefore, this information is N/A (not available).
\6\ Previous abundance estimates covering the entire stock's range are no longer considered reliable and the current estimates presented in the SARs and
reported here only cover a portion of the stock's range. Therefore, the calculated Nmin and PBR is based on the 2015 survey of only a small portion of
the stock's range. PBR is considered to be biased low since it is based on the whole stock whereas the estimate of mortality and serious injury is for
the entire stock's range.
\7\ Abundance estimates assumed that detection probability on the trackline was perfect; work is underway on a corrected estimate. Additionally,
preliminary data results based on eDNA analysis show genetic differentiation between harbor porpoise in the northern and southern regions on the
inland waters of southeast Alaska. Geographic delineation is not yet known. Data to evaluate population structure for harbor porpoise in Southeast
Alaska have been collected and are currently being analyzed. Should the analysis identify different population structure than is currently reflected
in the Alaska SARs, NMFS will consider how to best revise stock designations in the future.
As indicated above, all ten species (with twelve managed stocks) in
Table 2 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur, and we have proposed
authorizing it. Fin whale could potentially occur in the area, however
there are no known sightings nearby and USCG would shut down activity
if the whale enters the harassment zones. Therefore, given the former
and the rarity of the species, take is not expected to occur and they
are not discussed further.
In addition, the northern sea otter (Enhydra lutris kenyoni) may be
found in the Tongass Narrows. However, northern sea otters are managed
by the U.S. Fish and Wildlife Service and are not considered further in
this document.
Steller Sea Lion
Steller sea lions were listed as threatened range-wide under the
ESA on November 26, 1990 (55 FR 49204). Steller sea lions were
subsequently partitioned into the western and eastern Distinct
Population Segments (DPSs; western and eastern stocks) in 1997 (62 FR
24345; May 5, 1997). The eastern DPS remained classified as threatened
until it was delisted in November 2013. The current minimum abundance
estimate for the eastern DPS of Steller sea lions is 43,201 individuals
(Muto et al., 2021). The western DPS (those individuals west of the
144[deg]W longitude or Cape Suckling, Alaska) was upgraded to
endangered status following separation of the DPSs, and it remains
endangered today. There is regular movement of both DPSs across this
144[deg]W longitude boundary (Jemison et al., 2013), however, due to
the distance from this DPS boundary, it is likely that only eastern DPS
Steller sea lions are present in the project area. Therefore, animals
potentially affected by the project are assumed to be part of the
eastern DPS. Sea lions from the western DPS, are not likely to be
affected by the proposed activity and are not discussed further.
There are several mapped and regularly monitored long-term Steller
sea lion haulouts surrounding Ketchikan, such as West Rocks (36 mi/58
km) or Nose point (37 mi/60 km), but none are known to occur within
Tongass Narrows (Fritz et al., 2015). The nearest known Steller sea
lion haulout is located approximately 21 mi (34 km) west/northwest of
Ketchikan on Grindall Island. None of these haulouts would be affected
by the proposed activity. Summer counts of adult and juvenile sea lions
at on Grindall Island from 2000 through 2015 have averaged
approximately 191 individuals, with a range from 6 in 2009 to 378 in
2008. Only two winter surveys of this haulout have occurred. No sea
lion pups have been observed at this haulout during surveys. Although
this is a limited sample, it suggests that abundance may be consistent
year-round at the Grindall Island haulout.
No systematic studies of sea lion abundance or distribution have
occurred in Tongass Narrows. Anecdotal reports suggest that Steller sea
lions may be found in Tongass Narrows year-round, with an increase in
abundance from March to early May during the herring spawning season,
and another increase in late summer associated with salmon runs.
Overall sea lion presence in Tongass Narrows tends to be lower in
summer than in winter (FHWA, 2017). During summer, Steller sea lions
may aggregate outside the project area, at rookery and haulout sites.
Monitoring during construction of the Ketchikan Ferry Terminal in
summer (July 16 through August 17, 2016) did not record any Steller sea
lions (ADOT&PF, 2015); however, monitoring during construction of the
Ward Cove Dock, approximately 11 km northwest of the proposed project
site, recorded 181 individual sea lions between February and September
2020 (Power Systems & Supplies of Alaska, 2020). Most sightings
occurred in February (45 sightings of 88 sea lions) and March (34
sightings of 45 sea lions); the fewest number of sightings were
observed in May (1 sighting of 1 sea lion) (Power Systems & Supplies of
Alaska, 2020).
Sea lions are known to transit through Tongass Narrows while
pursing prey. Steller sea lions are known to follow fishing vessels,
and may congregate in small numbers at seafood processing facilities
and hatcheries or at the mouths of rivers and creeks containing
hatcheries, where large numbers of salmon congregate in late summer.
Three seafood processing facilities are located east of the proposed
berth location on Revillagigedo Island, and two salmon hatcheries
operated by the Alaska Department of Fish & Game (ADF&G) are located
east of the project area. Steller sea lions may aggregate near the
mouth of Ketchikan Creek, where a hatchery upstream supports a summer
salmon run. The Creek mouth
[[Page 30900]]
is more than 4 km (2.5 mi) form both ferry berth sites, and is
positioned behind the cruise ship terminal and within the small boat
harbor of Ketchikan. In addition to these locations, anecdotal
information from a local kayaking company suggests that there are
Steller sea lions present at Gravina Point, near the southwest entrance
to Tongass Narrows, about 3 mi (~5 km) southwest of the project site.
A total of 181 Steller sea lions were sighted on 44 separate days
during all months of the Ward Cove Cruise Ship Dock construction
project (February-September, 2020) (Power Systems and Supplies of
Alaska, 2020). Most sightings occurred in February and March and the
fewest sightings were in May. Sightings were of single individuals,
pairs, and herds of up to 10 individuals. They were identified as
traveling, foraging, swimming, chuffing, milling, looking, sinking,
spyhopping, and playing.
Harbor Seal
Harbor seals inhabit coastal and estuarine waters off Alaska. They
haul out on rocks, reefs, beaches, and drifting glacial ice. They are
opportunistic feeders and often adjust their distribution to take
advantage of locally and seasonally abundant prey (Womble et al., 2009,
Allen and Angliss, 2015).
Harbor seals occurring in the project area belong to the Clarence
Strait stock. Distribution of the Clarence Strait stock ranges from the
east coast of Prince of Wales Island from Cape Chacon north through
Clarence Strait to Point Baker and along the east coast of Mitkof and
Kupreanof Islands north to Bay Point, including Ernest Sound, Behm
Canal, and Pearse Canal (Muto et al., 2021). In the project area, they
tend to be more abundant during spring, summer and fall months when
salmon are present in Ward Creek. Anecdotal evidence indicates that
harbor seals typically occur in groups of 1-3 animals in Ward Cove with
a few sightings per day (Spokely, 2019). They were not observed in
Tongass Narrows during a combined 63.5 hours of marine mammal
monitoring that took place in 2001 and 2016 (OSSA, 2001, Turnagain,
2016). There are no known harbor seal haulouts within the project area.
According to the list of harbor seal haulout locations, the closest
listed haulouts are located off the tip of Gravina Island,
approximately 8 km (5 mi) northwest of Ward Cove (AFSC, 2018), however
none overlap with the proposed project area.
Killer Whale
Killer whales have been observed in all the world's oceans, but the
highest densities occur in colder and more productive waters found at
high latitudes (NMFS, 2016). Killer whales occur along the entire
Alaska coast, in British Columbia and Washington inland waterways, and
along the outer coasts of Washington, Oregon, and California (NMFS,
2016).
Based on data regarding association patterns, acoustics, movements,
and genetic differences, eight killer whale stocks are now recognized
within the Pacific U.S. Exclusive Economic Zone (U.S. EEZ). This
proposed IHA considers only the Eastern North Pacific Alaska Resident
stock (Alaska Resident stock), the Eastern North Pacific Northern
Resident stock (Northern Resident Stock), and the West Coast Transient
stock, as all other stocks do not overlap with the proposed project
area (Muto et al., 2021).
There are three distinct ecotypes, or forms, of killer whales
recognized: Resident, Transient, and Offshore. The three ecotypes
differ morphologically, ecologically, behaviorally, and genetically.
Surveys between 1991 and 2007 encountered resident killer whales during
all seasons throughout Southeast Alaska. Both residents and transients
were common in a variety of habitats and all major waterways, including
protected bays and inlets. There does not appear to be strong seasonal
variation in abundance or distributed of killer whales, but there was
substantial variability between years (Dahlheim et al., 2009). Spatial
distribution has been shown to vary among the different ecotypes, with
resident and, to a lesser extent, transient killer whales more commonly
observed along the continental shelf, and offshore killer whales more
commonly observed in pelagic waters (Rice et al., 2021).
No systematic studies of killer whales have been conducted in or
around Tongass Narrows. Killer whales have been observed in Tongass
Narrows year-round and are most common during the summer Chinook salmon
run (May-July). During the Chinook salmon run, Ketchikan residents have
reported pods of up to 20-30 whales (84 FR 36891; July 30, 2019).
Typical pod sizes observed within the project vicinity range from 1 to
10 animals and the frequency of killer whales passing through the
action area is estimated to be once per month (Frietag, 2017).
Anecdotal reports suggest that large pods of killer whales (as many as
80 individuals, but generally between 25 and 40 individuals) are not
uncommon in May, June, and July when the king salmon are running.
During the rest of the year, killer whales occur irregularly in pods of
6 to 12 or more individuals.
Transient killer whales are often found in long-term stable social
units (pods) of 1 to 16 whales. Average pod sizes in Southeast Alaska
were 6.0 in spring, 5.0 in summer and 3.9 in fall. Pod sizes of
transient whales are generally smaller than those of resident social
groups. Resident killer whales occur in larger pods, ranging from 7 to
70 whales that are seen in association with one another more than 50
percent of the time (Dahlheim et al., 2009).
Although killer whales may occur in large numbers, they generally
form large pods and would incur fewer work stoppages than their numbers
suggest since stoppages correlate more with the number of pods than the
number of individuals. Killer whales tend to transit through Tongass
Narrows, and do not linger in the project area.
Marine mammal observations in Tongass Narrows during 2020 and 2021
support an estimate of approximately one group of killer whales a month
in the project area. During 7 months of monitoring (October 2020-
February 2021; May-June 2021), there were five killer whale sightings
in 4 months (November, February, May, and June) totaling 22 animals and
sightings occurred on 5 out of 88 days of monitoring (DOT&PF, 2020,
2021a, 2021b, 2021c, 2021d). Pod sizes ranged from two to eight
animals. During the COK's monitoring for the Rock Pinnacle Removal
project in December 2019 and January 2020, no killer whales were
observed. Over eight months of monitoring at the Ward Cove Cruise Ship
Dock in occurred in 2020, and killer whales were only observed on two
days in March (Power Systems and Supplies of Alaska, 2020). These
observations included a sighting of one pod of two killer whales and a
second pod of five individuals travelling through the project area.
Pacific White-Sided Dolphin
Pacific white-sided dolphins are a pelagic species inhabiting
temperate waters of the North Pacific Ocean and along the coasts of
California, Oregon, Washington, and Alaska (Muto et al., 2021). Despite
their distribution mostly in deep, offshore waters, they may also be
found over the continental shelf and near shore waters, including
inland waters of Southeast Alaska (Ferrero and Walker, 1996). They are
managed as two distinct stocks: The California/Oregon/Washington stock,
and the North Pacific stock (north of 45 N, including Alaska). The
North Pacific stock ranges from
[[Page 30901]]
Canada into Alaska, and is thus the only stock that is found within the
project area (Muto et al., 2021).
Pacific white-sided dolphins prey on squid and small schooling fish
such as capelin, sardines, and herring (Morton, 2006). They are known
to work in groups to herd schools of fish and can dive underwater for
up to 6 minutes to feed (Morton, 2006). Group sizes have been reported
to range from 40 to over 1,000 animals, but groups of between 10 and
100 individuals occur most commonly (Stacey and Baird, 1991; NMFS no
date). Seasonal movements of Pacific white-sided dolphins are not well
understood, but there is evidence of both north-south seasonal movement
(Leatherwood et al., 1984) and inshore-offshore seasonal movement
(Stacey and Baird, 1991).
Scientific studies and data are lacking relative to the presence or
abundance of Pacific white-sided dolphins in or near Tongass Narrows.
Although they generally prefer deeper and more-offshore waters,
anecdotal reports suggest that Pacific white-sided dolphins have
previously been observed in Tongass Narrows, although they have not
been observed entering Tongass Narrows or nearby inter-island waterways
in 15-20 years.
Pacific white-sided dolphins are rare in the inside passageways of
Southeast Alaska. Most observations occur off the outer coast or in
inland waterways near entrances to the open ocean. According to Muto et
al., (2018), aerial surveys in 1997 sighted one group of 164 Pacific
white-sided dolphins in Dixon entrance to the south of Tongass Narrows.
Surveys in April and May from 1991 to 1993 identified Pacific white-
sided dolphins in Revillagigedo Channel, Behm Canal, and Clarence
Strait (Dahlheim and Towell 1994). There areas are contiguous within
the open ocean waters of the Dixon Entrance. This observational data,
combined with anecdotal information, indicates there is a rare,
however, slight potential for Pacific white-sided dolphins to occur in
the project area.
During marine mammal monitoring of the Tongass Narrows in 2020 and
2021, no Pacific white-sided dolphins were observed on 88 days of
observations across 7 months (October 2020-February 2021; May-June
2021), which supports anecdotal evidence that sightings of this species
are rare (DOT&PF, 2020, 2021a, 2021b, 2021c, 2021d). There were also no
sightings of Pacific white-sided dolphins during the COK Rock Pinnacle
Blasting Project during monitoring surveys conducted in December 2019
and January 2020 (Sitkiewicz, 2020) or during monitoring surveys
conducted between February-September 2020 as part of the Ward Cove
Cruise Ship Dock project (Power Systems and Supplies of Alaska, 2020).
Dall's Porpoise
Dall's porpoises are found throughout the North Pacific, from
southern Japan to southern California north to the Bering Sea. All
Dall's porpoises in Alaska are members of the Alaska stock. This
species can be found in offshore, inshore, and nearshore habitats.
Jefferson et al., (2019) presents historical survey data showing
few sightings in the Ketchikan area. The mean group size in Southeast
Alaska is estimated at approximately three individuals (Dahlheim et
al., 2009, Jefferson et al., 2019), although Freitag (2017, as cited in
83 FR 37473) suggested group sizes near Ketchikan range from 10 to 15
individuals. Anecdotal reports suggest that Dall's porpoises are found
northwest of Ketchikan near the Guard Islands, where waters are deeper,
as well as in deeper waters southeast of Tongass Narrows. This species
has a tendency to bow-ride with vessels and may occur in the action
area incidentally a few times per year. In March and April 2020, 8
individuals were identified across two sighting events during the Ward
Cove Cruise Ship Dock Project (Power Systems and Supplies of Alaska,
2020). No sightings were observed from December 2019-January 2020
during the COK Rock Pinnacle Blasting Project (Sitkiewics, 2020).
Harbor Porpoise
In the eastern North Pacific Ocean, the harbor porpoise ranges from
Point Barrow, along the Alaska coast, and down the west coast of North
America to Point Conception, California. The Southeast Alaska stock
ranges from Cape Suckling to the Canadian border (Muto et al., 2021).
Harbor porpoises frequent primarily coastal waters in Southeast Alaska
(Dahlheim et al., 2009) and occur most frequently in waters less than
100 m (328 ft) deep (Dahlhleim et al., 2015). They are not attracted to
areas with elevated levels of vessel activity and noise such as Tongass
Narrows.
Studies of harbor porpoises reported no evidence of seasonal
changes in distribution for the inland waters of Southeast Alaska
(Dahlheim et al., 2015). Ketchikan area densities are expected to be
low. This is supported by anecdotal estimates. There were no sightings
of harbor porpoises recorded during the December 2019-January 2020 COK
Rock Pinnacle Blasting Project (Sitkiewics, 2020). However, 15
individual harbor porpoises were sighted across three separate sighting
events in March and April 2020 during the Ward Cove Cruise Ship Dock
Project (Power Systems and Supplies of Alaska, 2020). Therefore, harbor
porpoises are expected to be present in the action area only a few
times per year.
Elephant Seals
Northern elephant seals breed and give birth in California and Baja
California, primarily on offshore islands (Stewart et al., 1994).
Spatial segregation in foraging areas between males and females is
evident from satellite tag data (Le Beouf et al., 2000). Males migrate
to the Gulf of Alaska and western Aleutian Islands along the
continental shelf to feed on benthic prey, while females migrate to
pelagic areas in the Gulf of Alaska and the central North Pacific to
feed on pelagic prey (Le Beouf et al., 2000). Elephant seals spend a
majority of their time at sea (average of 74.7 days during post
breeding migration and an average of 218.5 days during the post-molting
migration) (Robinson et al., 2012). Although northern elephant seals
are known to visit the Gulf of Alaska to feed, they are rarely found on
the beaches of Alaska. However, recent anecdotal evidence suggests that
their range is expanding northward, and one elephant seal has
repeatedly been spotted within Ketchikan in and around local docks
(ASE, 2022).
Humpback Whale
The humpback whale is found worldwide in all oceans. 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 established 14 DPSs with different listing statuses (81 FR
62259; September 8, 2016) pursuant to the ESA. Humpback whales found in
the project area are predominantly members of the Hawaii DPS, which is
not listed under the ESA. However, based on a comprehensive photo-
identification study, members of the Mexico DPS, which is listed as
threatened, have a small potential to occur in Southeast Alaska as
well. Members of different DPSs are known to intermix on feeding
grounds; therefore, all waters off the coast of Alaska should be
considered to have ESA-listed humpback whales. Approximately 1 percent
of all humpback whales in Southeast Alaska and northern British
Columbia are members of the listed Mexico DPS, while all others are
members of the non-listed Hawaii DPS (Wade et al., 2021). Therefore, in
consultation with the Alaska Regional Office, NMFS believes
[[Page 30902]]
that the listed DPS of humpback whales is not likely to be encountered
near the project area and, if perchance they are, required mitigation
will be required of USCG to avoid take of the ESA listed DPS of
humpback whales.
The DPSs of humpback whales that were identified through the ESA
listing process do not equate to the existing MMPA stocks. The stock
delineations of humpback whales under the MMPA are currently under
review. Until this review is complete, NMFS considers humpback whales
in Southeast Alaska to be part of the Central North Pacific stock, with
a status of endangered under the ESA and designations of strategic and
depleted under the MMPA (Muto et al., 2021).
Humpback whales experienced large population declines due to
commercial whaling operations in the early 20th century. Barlow (2003)
estimated the population of humpback whales at approximately 1,200
animals in 1966. The population in the North Pacific grew between 6,000
and 8,000 by the mid-1990s. Current threats to humpback whales include
vessel strikes, spills, climate change, and commercial fishing
operations (Muto et al., 2021).
Humpback whales are found throughout Southeast Alaska in a variety
of marine environments, including open-ocean, near-shore waters, and
areas within strong tidal currents (Dahlheim et al., 2009). Most
humpback whales are migratory and spend winters in the breeding grounds
off either Hawaii or Mexico. Humpback whales generally arrive in
Southeast Alaska in March and return to their wintering grounds in
November. Some humpback whales depart late or arrive early to feeding
grounds, and therefore the species occurs in the Southeast Alaska
region year-round (Straley, 1990, Straley et al., 2018). Across the
region, there have been no recent estimates of humpback whale density.
No systematic studies have documented humpback whale abundance near
Ketchikan. Anecdotal information suggests that this species is present
in low numbers year-round in Tongass Narrows, with the highest
abundance during summer and fall. Anecdotal reports suggest that
humpback whales are seen only once or twice per month, while more
recently it has been suggested that the occurrence is more regular,
such as once per week on average, and more seasonal. Humpbacks observed
in Tongass Narrows are generally alone or in groups of one to three
individuals. In August 2017, a group of 6 individuals was observed
passing through Tongass Narrows several times per day, for several days
in a row.
The City of Ketchikan (COK) Rock Pinnacle project, which was
located approximately 2.25 kilometers (km) north of USCG's proposed
project site, reported one humpback whale sighting of one individual
during the project (December 2019 through January 2020). During the
Ward Cove Cruise Ship Dock Construction, located approximately 11 km
northwest of the proposed project site, 28 sightings of humpbacks were
made on eighteen days of in water work that occurred between February
and September 2020, with at least one humpback being recorded every
month. A total of 42 individuals were recorded and group sizes ranged
from 1 to 6 (Power Systems & Supplies of Alaska, 2020). Humpback whales
were sighted on 17 days out of 88 days of monitoring in Tongass Narrows
in 2020 and 2021 (DOT&PF 2020, 2021a, 2021b, 2021c, 2021d). There were
no sightings in January or February, but humpback whales were observed
each month from October to December 2020 and May to June 2021. During
November 2020, a single known individual (by fluke pattern) was
observed repeatedly, accounting for 14 of the 26 sighting events that
month (DOT&PF, 2020). During monitoring, humpback whales were observed
on average once a week.
Southeast Alaska is considered an important area for feeding
humpback whales between March and May (Ellison et al., 2012), though
not currently designated as critical habitat (86 FR 21082; April 21,
2021). In Alaska, humpback whales filter feed on tiny crustaceans,
plankton, and small fish such as walleye Pollock, Pacific sand lance,
herring, eulachon (Thaleichthys pacificus), and capelin (Witteveen et
al., 2012).
Minke Whale
Minke whales are found throughout the northern hemisphere in polar,
temperate, and tropical waters. The population status of minke whales
is considered stable throughout most of their range. Historically,
commercial whaling reduced the population size of this species, but
given their small size, they were never a primary target of whaling and
did not experience the severe population declines as did larger
cetaceans.
Minke whales are found in all Alaska waters. Minke whales in
Southeast Alaska are part of the Alaska stock (Muto et al., 2021).
Research in Southeast Alaska have consistently identified individuals
throughout inland waters in low numbers (Dahlheim et al., 2009). All
sightings were of single minke whales, except for a single sighting of
multiple minke whales. Surveys took place in spring, summer, and fall,
and minke whales were present in low numbers in all seasons and years.
No information appears to be available on the winter occurrence of
minke whales in Southeast Alaska.
There are no known occurrences of minke whales within the project
area. Since their ranges extend into the project area and they have
been observed in southeast Alaska, including in Clarence Strait
(Dahlheim et al., 2009), it is possible the species could occur near
the project area. No minke whales were reported during the COK Rock
Pinnacle Blasting Project (Sitkiewicz, 2020). During marine mammal
monitoring of Tongass Narrows in 2020 and 2021, there were no minke
whales observed over 88 days of observations across 7 months (October
2020-February 2021; May-June 2021) (DOT&PF 2020, 2021a, 2021b, 2021c,
2021d).
In Alaska, the minke whale diet consists primarily of euphausiids
and walleye Pollock. Minke whales are generally found in shallow,
coastal waters within 200 m of shore (Zerbini et al., 2006) and are
almost always solitary or in small groups of 2 to 3. In Alaska,
seasonal movements are associated with feeding areas that are generally
located at the edge of the pack ice (NMFS, 2014).
Gray Whale
Gray whales are distributed throughout the North Pacific Ocean and
are found primarily in shallow coastal waters (Muto et al., 2021). Gray
whales in the Eastern North Pacific stock range from the southern Gulf
of California, Mexico to the arctic waters of the Bering and Chukchi
Seas. Gray whales are generally solitary creatures and travel together
alone or in small groups.
Gray whales are rare in the action area and unlikely to occur in
Tongass Narrows. They were not observed during the Dahlheim et al.,
(2009) surveys of Alaska's inland waters with surveys conducted in the
spring, summer and fall months. No gray whales were reported during COK
Rock Pinnacle Blasting Project (Sitkiewicz, 2020) or Ward Cove (Power
Systems & Supplies of Alaska, 2020). However, a gray whale could
migrate through or near the project area during November especially.
There is an ongoing Unusual Mortality Event (UME) involving gray
whales on the Pacific Coast (https://www.fisheries.noaa.gov/national/
marine-life-distress/2019-2021-gray-
[[Page 30903]]
whale-unusual-mortality-event-along-west-coast-and). Almost half of the
standings in the United States have been in Alaska. A definitive cause
has not been found for the UME but many of the animals show signs of
emaciation.
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. Current data indicate that 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) recommended that marine mammals be divided
into functional hearing groups based on directly measured or estimated
hearing ranges on the basis of available behavioral response data,
audiograms derived using auditory evoked potential techniques,
anatomical modeling, and other data. Note that no direct measurements
of hearing ability have been successfully completed for mysticetes
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65
decibel (dB) threshold from the normalized composite audiograms, with
the exception for lower limits for low-frequency cetaceans where the
lower bound was deemed to be biologically implausible and the lower
bound from Southall et al. (2007) retained. Marine mammal hearing
groups and their associated hearing ranges are provided in Table 3.
Table 3--Marine Mammal Hearing Groups
[NMFS, 2018]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans 150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
whales, bottlenose whales).
High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
Cephalorhynchid, Lagenorhynchus
cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) 50 Hz to 86 kHz.
(true seals).
Otariid pinnipeds (OW) (underwater) 60 Hz to 39 kHz.
(sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al. 2,007) 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 summary and 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 how those
impacts on individuals are likely to impact marine mammal species or
stocks.
Acoustic effects on marine mammals during the specified activity
can occur from impact pile driving, vibratory driving and DTH. The
effects of underwater noise from USCG's proposed activities have the
potential to result in Level A or Level B harassment of marine mammals
in the action area.
Description of Sound Source
The marine soundscape is comprised of both ambient and
anthropogenic sounds. Ambient sound is defined as the all-encompassing
sound in a given place and is usually a composite of sound from many
sources both near and far. The sound level of an area is defined by the
total acoustical energy being generated by known and unknown sources.
These sources may include physical (e.g., waves, wind, precipitation,
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced
by marine mammals, fish, and invertebrates), and anthropogenic sound
(e.g., vessels, dredging, aircraft, construction).
The sum of the various natural and anthropogenic sound sources at
any given location and time--which comprise ``ambient'' or
``background'' sound--depends not only on the source levels (as
determined by current weather conditions and levels of biological and
shipping activity) but also on the ability of sound to propagate
through the environment. In turn, sound propagation is dependent on the
spatially and temporally varying properties of the water column and sea
floor, and is frequency-dependent. As a result of the dependence on a
large number of varying factors, ambient sound levels can be expected
to vary widely over both coarse and fine spatial and temporal scales.
Sound levels at a given frequency and location can vary by 10-20 dB
from day to day (Richardson et al., 1995). The result is that,
depending on the source type and its intensity, sound from the
specified activity may be a negligible addition to the local
environment or could form a distinctive signal that may affect marine
mammals.
In-water construction activities associated with the project would
include vibratory pile removal, impact and vibratory pile driving, and
drilling. The sounds produced by these activities fall into one of two
general sound types: Impulsive and non-impulsive. Impulsive sounds
(e.g., explosions, gunshots, sonic booms, impact pile driving) are
typically transient, brief (less than 1 second), broadband, and consist
of high peak sound pressure with rapid rise time and rapid decay (ANSI
1986; NIOSH 1998; ANSI 2005; NMFS 2018a). Non-impulsive sounds (e.g.,
aircraft, machinery operations
[[Page 30904]]
such as drilling or dredging, vibratory pile driving, and active sonar
systems) can be broadband, narrowband or tonal, brief or prolonged
(continuous or intermittent), and typically do not have the high peak
sound pressure with raid rise/decay time that impulsive sounds do (ANSI
1995; NIOSH 1998; NMFS 2018a). The distinction between these two sound
types is important because they have differing potential to cause
physical effects, particularly with regard to hearing (e.g., Ward 1997
in Southall et al., 2007).
Three types of hammers would be used on this project: Impact,
vibratory, and DTH. Impact hammers operate by repeatedly dropping a
heavy piston onto a pile to drive the pile into the substrate. Sound
generated by impact hammers is characterized by rapid rise times and
high peak levels, a potentially injurious combination (Hastings and
Popper, 2005). Vibratory hammers install piles by vibrating them and
allowing the weight of the hammer to push them into the sediment.
Vibratory hammers produce significantly less sound than impact hammers.
Peak sound pressure levels (SPLs) may be 180 dB or greater, but are
generally 10 to 20 dB lower than SPLs generated during impact pile
driving of the same-sized pile (Oestman et al., 2009). Rise time is
slower, reducing the probability and severity of injury, and sound
energy is distributed over a greater amount of time (Nedwell and
Edwards 2002; Carlson et al., 2005).
A DTH hammer is essentially a drill bit that drills through the
bedrock using a rotating function like a normal drill, in concert with
a hammering mechanism operated by a pneumatic (or sometimes hydraulic)
component integrated into the DTH hammer to increase speed of progress
through the substrate (i.e., it is similar to a ``hammer drill'' hand
tool). Rock socketing involves using DTH equipment to create a hole in
the bedrock inside of which the pile is placed to give it lateral and
longitudinal strength. The sounds produced by the DTH method contain
both a continuous non-impulsive component from the drilling action and
an impulsive component from the hammering effect. Therefore, we treat
DTH systems as both impulsive and non-impulsive sound source types
simultaneously.
The likely or possible impacts of USCG's proposed activity on
marine mammals could involve both non-acoustic and acoustic stressors.
Potential non-acoustic stressors could result from the physical
presence of equipment and personnel; however, any impacts to marine
mammals are expected to be primarily acoustic in nature. Acoustic
stressors include effects of heavy equipment operation during pile
driving and drilling.
Acoustic Impacts
The introduction of anthropogenic noise into the aquatic
environment from pile driving or drilling is the primary means by which
marine mammals may be harassed from the USCG's specified activity. In
general, animals exposed to natural or anthropogenic sound may
experience physical and psychological effects, ranging in magnitude
from none to severe (Southall et al., 2007). In general, exposure to
pile driving or drilling 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 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 or drilling
noise on marine mammals are dependent on several factors, including,
but not limited to, sound type (e.g., impulsive vs. non-impulsive), the
species, age and sex class (e.g., adult male vs. mom with calf),
duration of exposure, the distance between the pile and the animal,
received levels, behavior at time of exposure, and previous history
with exposure (Wartzok et al., 2004; Southall et al., 2007). Here we
discuss physical auditory effects (threshold shifts) followed by
behavioral effects and potential impacts on habitat.
NMFS defines a noise-induced threshold shift (TS) as a change,
usually an increase, in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS 2018). The amount of
threshold shift is customarily expressed in decibels (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 an animal uses sound within the
frequency band of the signal; e.g., Kastelein et al., 2014), and the
overlap between the animal and the source (e.g., spatial, temporal, and
spectral).
Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent,
irreversible increase in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS 2018). Available data from
humans and other terrestrial mammals indicate that a 40 dB threshold
shift approximates PTS onset (see Ward et al., 1958, 1959; Ward 1960;
Kryter et al., 1966; Miller 1974; Ahroon et al., 1996; Henderson et
al., 2008). PTS levels for marine mammals are estimates, as with the
exception of a single study unintentionally inducing PTS in a harbor
seal (Kastak et al., 2008), there are no empirical data measuring PTS
in marine mammals largely due to the fact that, for various ethical
reasons, experiments involving anthropogenic noise exposure at levels
inducing PTS are not typically pursued or authorized (NMFS 2018).
Temporary Threshold Shift (TTS)--TTS is a temporary, reversible
increase in the threshold of audibility at a specified frequency or
portion of an individual's hearing range above a previously established
reference level (NMFS 2018). Based on data from cetacean TTS
measurements (see Southall et al., 2007), a TTS of 6 dB is considered
the minimum threshold shift clearly larger than any day-to-day or
session-to-session variation in a subject's normal hearing ability
(Schlundt et al., 2000; Finneran et al., 2000, 2002). As described in
Finneran (2015), marine mammal studies have shown the amount of TTS
increases with cumulative sound exposure level (SELcum) in an
accelerating fashion: At low exposures with lower SELcum, the amount of
TTS is typically small and the growth curves have shallow slopes. At
exposures with higher SELcum, the growth curves become steeper and
approach linear relationships with the noise SEL.
Depending on the degree (elevation of threshold in dB), duration
(i.e., recovery time), and frequency range of TTS, and the context in
which it is experienced, TTS can have effects on marine mammals ranging
from discountable to serious (similar to those discussed in 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
[[Page 30905]]
through the open ocean, where ambient noise is lower and there are not
as many competing sounds present. Alternatively, a larger amount and
longer duration of TTS sustained during a time when communication is
critical for successful mother/calf interactions could have more
serious impacts. We note that reduced hearing sensitivity as a simple
function of aging has been observed in marine mammals, as well as
humans and other taxa (Southall et al., 2007), so we can infer that
strategies exist for coping with this condition to some degree, though
likely not without cost.
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). 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. 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 a combination of drilling, impact pile
driving and vibratory pile driving. For this project, these activities
would not occur at the same time and there would be pauses in
activities producing the sound during each day. Given these pauses and
that many marine mammals are likely moving through the ensonified area
and not remaining for extended periods of time, the potential for TS
declines.
Behavioral Harassment--Exposure to noise from pile driving and
removal also has the potential to behaviorally disturb marine mammals.
Available studies show wide variation in response to underwater sound;
therefore, it is difficult to predict specifically how any given sound
in a particular instance might affect marine mammals perceiving the
signal. If a marine mammal does react briefly to an underwater sound by
changing its behavior or moving a small distance, the impacts of the
change are unlikely to be significant to the individual, let alone the
stock or population. However, if a sound source displaces marine
mammals from an important feeding or breeding area for a prolonged
period, impacts on individuals and populations could be significant
(e.g., Lusseau and Bejder 2007; Weilgart 2007; 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); avoidance of areas where sound sources are located.
Pinnipeds may increase their haul out time, possibly to avoid in-water
disturbance (Thorson and Reyff 2006). Behavioral responses to sound are
highly variable and context-specific and any reactions depend on
numerous intrinsic and extrinsic factors (e.g., species, state of
maturity, experience, current activity, reproductive state, auditory
sensitivity, time of day), as well as the interplay between factors
(e.g., Richardson et al., 1995; Wartzok et al., 2003; Southall et al.,
2007; Weilgart 2007; Archer et al., 2010). Behavioral reactions can
vary not only among individuals but also within an individual,
depending on previous experience with a sound source, context, and
numerous other factors (Ellison et al., 2012), and can vary depending
on characteristics associated with the sound source (e.g., whether it
is moving or stationary, number of sources, distance from the source).
In general, pinnipeds seem more tolerant of, or at least habituate more
quickly to, potentially disturbing underwater sound than do cetaceans,
and generally seem to be less responsive to exposure to industrial
sound than most cetaceans. Please see Appendices B-C of Southall et
al., (2007) for a review of studies involving marine mammal behavioral
responses to sound.
Disruption of feeding behavior can be difficult to correlate with
anthropogenic sound exposure, so it is usually inferred by observed
displacement from known foraging areas, the appearance of secondary
indicators (e.g., bubble nets or sediment plumes), or changes in dive
behavior. As for other types of behavioral response, the frequency,
duration, and temporal pattern of signal presentation, as well as
differences in species sensitivity, are likely contributing factors to
differences in response in any given circumstance (e.g., Croll et al.,
2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko et al.,
2007). A determination of whether foraging disruptions incur fitness
consequences would require information on or estimates of the energetic
requirements of the affected individuals and the relationship between
prey availability, foraging effort and success, and the life history
stage of the animal.
Stress responses--An animal's perception of a threat may be
sufficient to trigger stress responses consisting of some combination
of behavioral responses, autonomic nervous system responses,
neuroendocrine responses, or immune responses (e.g., Seyle 1950; Moberg
2000). In many cases, an animal's first and sometimes most economical
(in terms of energetic costs) response is behavioral avoidance of the
potential stressor. Autonomic nervous system responses to stress
typically involve changes in heart rate, blood pressure, and
gastrointestinal activity. These responses have a relatively short
duration and may or may not have a significant long-term effect on an
animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that
are affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been
implicated in failed reproduction, altered metabolism, reduced immune
competence, and behavioral disturbance (e.g., Moberg 1987; Blecha
2000). Increases in the circulation of glucocorticoids are also equated
with stress (Romano et al., 2004).
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and ``distress'' is the cost of
the response. During a stress response, an animal uses glycogen stores
that can be quickly replenished once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other functions. This state of
distress will last until the animal replenishes its energetic reserves
sufficient to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well studied through
controlled experiments and for both laboratory and free-ranging animals
[[Page 30906]]
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003;
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to
exposure to anthropogenic sounds or other stressors and their effects
on marine mammals have also been reviewed (Fair and Becker 2000; Romano
et al., 2002b) and, more rarely, studied in wild populations (e.g.,
Romano et al., 2002a). For example, Rolland et al., (2012) found that
noise reduction from reduced ship traffic in the Bay of Fundy was
associated with decreased stress in North Atlantic right whales. These
and other studies lead to a reasonable expectation that some marine
mammals will experience physiological stress responses upon exposure to
acoustic stressors and that it is possible that some of these would be
classified as ``distress.'' In addition, any animal experiencing TTS
would likely also experience stress responses (NRC, 2003), however
distress is an unlikely result of this project based on observations of
marine mammals during previous, similar projects in the area.
Masking--Sound can disrupt behavior through masking, or interfering
with, an animal's ability to detect, recognize, or discriminate between
acoustic signals of interest (e.g., those used for intraspecific
communication and social interactions, prey detection, predator
avoidance, navigation) (Richardson et al., 1995). Masking occurs when
the receipt of a sound is interfered with by another coincident sound
at similar frequencies and at similar or higher intensity, and may
occur whether the sound is natural (e.g., snapping shrimp, wind, waves,
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar,
seismic exploration) in origin. The ability of a noise source to mask
biologically important sounds depends on the characteristics of both
the noise source and the signal of interest (e.g., signal-to-noise
ratio, temporal variability, direction), in relation to each other and
to an animal's hearing abilities (e.g., sensitivity, frequency range,
critical ratios, frequency discrimination, directional discrimination,
age or TTS hearing loss), and existing ambient noise and propagation
conditions. Masking of natural sounds can result when human activities
produce high levels of background sound at frequencies important to
marine mammals. Conversely, if the background level of underwater sound
is high (e.g., on a day with strong wind and high waves), an
anthropogenic sound source would not be detectable as far away as would
be possible under quieter conditions and would itself be masked.
Airborne Acoustic Effects--Although pinnipeds are known to haul-out
regularly on man-made objects we believe that incidents of take
resulting solely from airborne sound are unlikely due to the sheltered
proximity between the proposed project area and these haulout sites
(over 20 miles (32.19 km)). There is a possibility that an animal could
surface in-water, but with head out, within the area in which airborne
sound exceeds relevant thresholds and thereby be exposed to levels of
airborne sound that we associate with harassment, but any such
occurrence would likely be accounted for in our estimation of
incidental take from underwater sound. Therefore, authorization of
incidental take resulting from airborne sound for pinnipeds is not
warranted, and airborne sound is not discussed further here. Cetaceans
are not expected to be exposed to airborne sounds that would result in
harassment as defined under the MMPA.
Marine Mammal Habitat Effects
The USCG's construction activities could have localized, temporary
impacts on marine mammal habitat and their pretty by increasing in-
water sound pressure levels and slightly decreasing water quality.
However, since the focus of the proposed action is pile driving and
drilling, no net habitat loss is expect as the floating dock will be a
small extension of the current dock, replacing the location of the
existing wave attenuator (see Figure 2). Construction activities are of
short duration and would likely have temporary impacts on marine mammal
habitat through increases in underwater and airborne sound. Increased
noise levels may affect acoustic habitat (see masking discussion above)
and adversely affect marine mammal prey in the vicinity of the project
area (see discussion below). During DTH, impact and vibratory pile
driving, elevated levels of underwater noise would ensonify the project
area where both fish and mammals occur and could affect foraging
success. Additionally, marine mammals may avoid the area during
construction, however, displacement due to noise is expected to be
temporary and is not expected to result in long-term effects to the
individuals or populations.
Temporary and localized 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 meter) radius around
the pile (Everitt et al., 1980). The sediments of the project site will
settle out rapidly when disturbed. Cetaceans are not expected to be
close enough to the pile driving areas to experience effects of
turbidity, and any pinnipeds could avoid localized areas of turbidity.
Local strong currents are anticipated to disburse any additional
suspended sediments produced by project activities at moderate to rapid
rates depending on tidal stage. Therefore, we expect the impact from
increased turbidity levels to be discountable to marine mammals and do
not discuss it further.
In-Water Construction Effects on Potential Foraging Habitat
The proposed activities would not result in permanent impacts to
habitats used directly by marine mammals except for the actual
footprint of the floating dock extension. The total seafloor area
likely impacted by the project is relatively small compared to the
available habitat in Southeast Alaska and does not include any
Biologically Important Areas or other habitat of known importance. The
area is highly influenced by anthropogenic activities. Additionally,
the total seafloor area affected by pile installation and removal is a
small area compared to the vast foraging area available to marine
mammals in the area. At best, the impact area provides marginal
foraging habitat for marine mammals and fishes. Furthermore, pile
driving at the project site would not obstruct movements or migration
of marine mammals.
Avoidance by potential prey (i.e., fish) of the immediate area due
to the temporary loss of this foraging habitat is also possible. The
duration of fish avoidance of this area after pile driving stops is
unknown, but a rapid return to normal recruitment, distribution and
behavior is anticipated. Any behavioral avoidance by fish of the
disturbed area would still leave significantly large areas of fish and
marine mammal foraging habitat in the nearby vicinity.
Effects on Potential Prey
Sound may affect marine mammals through impacts on the abundance,
behavior, or distribution of prey species (e.g., crustaceans,
cephalopods, fish, zooplankton, etc.). Marine mammal prey varies by
species, season, and location. Here, we describe studies regarding the
effects of noise on known marine mammal prey.
Fish utilize the soundscape and components of sound in their
environment to perform important functions such as foraging, predator
[[Page 30907]]
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, although several are
based on studies in support of large, multiyear bridge construction
projects (e.g., Scholik and Yan, 2001, 2002; Popper and Hastings,
2009). Several studies have demonstrated that impulse sounds might
affect the distribution and behavior of some fishes, potentially
impacting foraging opportunities or increasing energetic costs (e.g.,
Fewtrell and McCauley, 2012; Pearson et al., 1992; Skalski et al.,
1992; Santulli et al., 1999; Paxton et al., 2017). However, some
studies have shown no or slight reaction to impulse sounds (e.g., Pena
et al., 2013; Wardle et al., 2001; Jorgenson and Gyselman, 2009; Popper
et al., 2015).
SPLs of sufficient strength have been known to cause injury to fish
and fish mortality. However, in most fish species, hair cells in the
ear continuously regenerate and loss of auditory function likely is
restored when damaged cells are replaced with new cells. Halvorsen et
al., (2012a) showed that a TTS of 4-6 dB was recoverable within 24
hours for one species. Impacts would be most severe when the individual
fish is close to the source and when the duration of exposure is long.
Injury caused by barotrauma can range from slight to severe and can
cause death, and is most likely for fish with swim bladders. Barotrauma
injuries have been documented during controlled exposure to impact pile
driving (Halvorsen et al., 2012b; Casper et al., 2013).
The most likely impact to fish from pile driving activities at the
project areas would be temporary behavioral avoidance of the area. The
duration of fish avoidance of an area after pile driving stops is
unknown, but a rapid return to normal recruitment, distribution and
behavior is anticipated.
Construction activities, in the form of increased turbidity, have
the potential to adversely affect forage fish in the project area.
Forage fish form a significant prey base for many marine mammal species
that occur in the project area. Increased turbidity is expected to
occur in the immediate vicinity (on the order of 10 ft (3 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 Tongass Narrows 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 action
are not likely to have a permanent adverse effect on any fish habitat,
or populations of fish species. Any behavioral avoidance by fish of the
disturbed area would still leave significantly large areas of fish and
marine mammal foraging habitat in the nearby vicinity. Thus, we
conclude that impacts of the specified activity are not likely to have
more than short-term adverse effects on any prey habitat or populations
of prey species. Further, any impacts to marine mammal habitat are not
expected to result in significant or long-term consequences for
individual marine mammals, or to contribute to adverse impacts on their
populations.
Estimated Take
This section provides an estimate of the number of incidental takes
proposed for authorization through this IHA, which will inform both
NMFS' consideration of ``small numbers'' and the negligible impact
determinations.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes would primarily be by Level B harassment, as use
of the acoustic sources (i.e., vibratory or impact pile driving and
DTH) has the potential to result in disruption of behavioral patterns
for individual marine mammals. There is also some potential for
auditory injury (Level A harassment) to result, primarily for porpoises
and harbor seals, due to the cryptic nature of these species in context
of larger predicted auditory injury zones. Auditory injury is unlikely
to occur for low- and mid-frequency species and otariids, based on the
relatively small predicted zones for the latter two groups and because
of the expected ease of detection for the former group. The proposed
mitigation and monitoring measures are expected to minimize the
severity of the taking to the extent practicable.
As described previously, no mortality is anticipated or proposed to
be authorized for this activity. Below we describe how the take is
estimated.
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)
and the number of days of activities. We note that while these basic
factors can contribute to a basic calculation to provide an initial
prediction of 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
estimate.
Acoustic Thresholds
NMFS recommends the use of acoustic thresholds that identify the
received level of underwater sound above which exposed marine mammals
[[Page 30908]]
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). Thresholds have also been developed identifying the
received level of in-air sound above which exposed pinnipeds would
likely be behaviorally harassed.
Level B Harassment for non-explosive sources--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 (e.g., frequency, predictability,
duty cycle), the environment (e.g., bathymetry), and the receiving
animals (hearing, motivation, experience, demography, behavioral
context) and can be difficult to predict (Southall et al., 2007,
Ellison et al., 2012). Based on what the available science indicates
and the practical need to use a threshold based on a factor that is
both predictable and measurable for most activities, NMFS uses a
generalized acoustic threshold based on received level to estimate the
onset of behavioral harassment. NMFS predicts that marine mammals are
likely to be behaviorally harassed in a manner we consider Level B
harassment when exposed to underwater anthropogenic noise above
received levels of 120 dB re 1 microPascal ([mu]Pa) (rms) for
continuous (e.g., vibratory pile-driving, drilling) and above 160 dB re
1 [mu]Pa (rms) for non-explosive impulsive (e.g., seismic airguns) or
intermittent (e.g., scientific sonar) sources. USCG's activity includes
the use of continuous (vibratory hammer and DTH) and impulsive (DTH and
impact pile-driving), and therefore the 120 and 160 dB re 1 [mu]Pa
(rms) are applicable.
Level A harassment for non-explosive sources--NMFS' Technical
Guidance for Assessing the Effects of Anthropogenic Sound on Marine
Mammal Hearing (Version 2.0) (Technical Guidance, 2018) identifies dual
criteria to assess auditory injury (Level A harassment) to five
different marine mammal groups (based on hearing sensitivity) as a
result of exposure to noise from two different types of sources
(impulsive or non-impulsive). USCG's proposed activity includes the use
of impulsive (impact pile-driving and DTH) and non-impulsive (vibratory
hammer and DTH) sources.
These thresholds are provided in Table 4 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="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 218 dB; Cell 8: LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect 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 will feed into identifying the area ensonified above the
acoustic thresholds, which include 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 via sound generated by the
primary components of the project (i.e., impact pile driving, vibratory
pile driving, vibratory pile removal, and DTH).
In order to calculate distances to the Level A harassment and Level
B harassment sound thresholds for the methods and piles being used in
this project, NMFS used acoustic monitoring data from other locations
to develop source levels for the various pile types, sizes and methods
(Table 5).
Table 5--Observed Source Levels for Pile Installation and Removal
----------------------------------------------------------------------------------------------------------------
Peak SPL RMS SPL
(re 1 (re 1 SEL (re
Activity [mu]Pa [mu]Pa 1 [mu]Pa Source
(rms)) (rms)) (rms))
----------------------------------------------------------------------------------------------------------------
DTH (24-inch Steel Pipe)..................... 184 167 159 Heyvaert & Reyff, 2021.
Vibratory (24-inch Steel Pipe) *............. 175 162 160 Denes et al., 2016.
Impact (24-Inch Steel Pipe).................. 207 194 178 Caltrans 2020.
----------------------------------------------------------------------------------------------------------------
Note: SELss = single strike sound exposure level; RMS = root mean square.
* Source levels proposed here differ from those used in USCG's application.
[[Page 30909]]
When the NMFS Technical Guidance (2016) was published, in
recognition of the fact that ensonified area/volume could be more
technically challenging to predict because of the duration component in
the new thresholds, we developed a User Spreadsheet that includes tools
to help predict a simple isopleth that can be used in conjunction with
marine mammal density or occurrence to help predict takes. We note that
because of some of the assumptions included in the methods used for
these tools, we anticipate that isopleths produced are typically going
to be overestimates of some degree, which may result in some degree of
overestimate of Level A harassment take. However, these tools offer the
best way to predict appropriate isopleths when more sophisticated 3D
modeling methods are not available, and NMFS continues to develop ways
to quantitatively refine these tools, and will qualitatively address
the output where appropriate. For stationary sources such as vibratory
and impact pile driving, vibratory removal and DTH, NMFS User
Spreadsheet predicts the distance at which, if a marine mammal remained
at that distance the whole duration of the activity, it would incur
PTS. Inputs used in the User Spreadsheet are reported in Table 1 and
source levels used in the User Spreadsheet are reported in Table 5.
Resulting isopleths are reported in Table 6.
Table 6--Level A and Level B Harassment Isopleths for Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
Level A harassment isopleths (PTS) (meters) Level B
Activity ----------------------------------------------------------------- harassment
LF MF HF Phocids Otariids isopleths (m)
----------------------------------------------------------------------------------------------------------------
DTH (24-inch Steel Pipe).... 434.1 15.4 517.1 232.3 16.9 13,594
Vibratory (24-inch Steel 1 0.1 1.5 0.6 0.1 * 6,310
Pipe)......................
Impact (24-Inch Steel Pipe). 21.5 0.8 25.6 11.5 0.8 1,848
----------------------------------------------------------------------------------------------------------------
* Differs from USCG's application due to difference in source level use. See Table 5.
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 take
calculations. We also describe how the information provided above is
brought together to produce a quantitative take estimate.
Available information regarding marine mammal occurrence and
abundance in the vicinity of USCG Base Ketchikan includes monitoring
reports from prior incidental take authorizations (the Tongass Narrows
project (85 FR 673; January 7, 2020)) and ESA consultations on
additional projects and is described below for each species. A summary
of proposed take is in Table 7.
Steller Sea Lions
Steller sea lions are anticipated to occur in the vicinity of Base
Ketchikan in the Tongass Narrows. As Base Ketchikan is far enough east
of the line dividing the Eastern and Western stocks, only members of
the Eastern Stock of Steller sea lions are anticipated to occur at Base
Ketchikan. Sightings of Steller sea lions are expected to occur once a
day with the total number of Steller sea lions in the project area
reaching up to 10 animals. The project involves 30 days of potential
in-water work. Therefore, we estimate total take at 10 sea lions x 30
days = 300 takes at the Level B harassment level. Because the shutdown
zone is small and Steller sea lions are not cryptic, we believe the
Level A harassment shutdown zone can be fully implemented by Protected
Species Observers (PSOs) and no Level A harassment take is proposed for
authorization.
Harbor Seal
Harbor seals are anticipated to occur in the project area once per
day. The typical number of harbor seals observed in the project area is
up to 12 animals per day. We estimate total take at 12 seals x 30 days
of activity = 360 takes. Because of the relatively large Level A
harassment zones for impact pile driving and DTH, and because harbor
seals are small and cryptic species that could sometimes remain
undetected within the estimated harassment zones for a duration
sufficient to experience PTS, we propose to authorize 10 takes (1 seal
per day for the expected 10 days of impact pile driving and DTH) by
Level A harassment, and 350 takes by Level B harassment, equaling the
total proposed authorized take to 360.
Dall's Porpoise
Previous construction project monitoring in the Ketchikan area
reported approximately two Dall's porpoises per day (NMFS, 2021).
Therefore, we estimate total take at 2 porpoises per day x 30 days = 60
takes. Forty of these takes are expected to be Level B harassment
takes. Because Dall's porpoises are small and cryptic species and could
sometimes remain undetected within the estimated harassment zones for a
duration sufficient to experience PTS, we proposed to authorize 20
takes by Level A harassment.
Harbor Porpoise
Harbor porpoises are expected to occur in the project area no more
than three times per month and the typical group size for harbor
porpoises in the project area is 5 animals. The project involves 30
days (1 month) of in-water work where take could occur. Therefore, we
estimate total take at 5 porpoises x 3 sightings = 15 takes. Because
harbor porpoises are small and cryptic species and could remain
undetected within the estimated harassment zones for a duration
sufficient to experience PTS, we propose to authorize 5 takes by Level
A harassment and 10 takes by Level B harassment.
Pacific White-Sided Dolphin
Previous construction project monitoring in the Ketchikan area
reported approximately 2.86 Pacific white-sided dolphins per day
(reported value of 20 dolphins over one week of monitoring) (NMFS,
2021). Therefore we estimate 2.86 dolphins x 30 days = 86 takes. All of
these takes are expected to be by Level B harassment as we believe the
Level A shutdown zones can be fully implemented by PSOs due to their
large group size, short dive duration, and easy detection of Pacific
white-sided dolphins, in addition to the smaller size of the shutdown
zones.
Killer Whale
Killer whales are expected to occur in the project area no more
than once per month. Typically a group size for killer whales in the
project area is conservatively estimated at 10 animals, which equates
to 0.4 animals per day. Therefore, we estimate total take at 0.4 whales
x 30 days = 12 takes. All of these takes are expected to be Level B
harassment takes as we believe the Level A shutdown zones can be fully
[[Page 30910]]
implemented by PSOs because of the large size of the animal, short dive
duration, and obvious behavior of killer whales, in additional to the
small size of the shutdown zones.
Gray Whale
Gray whales are expected to occur no more than once per month.
Typical group size for gray whales in the project area is two animals.
Therefore, we conservatively propose to authorize a single group size
for the full 30 days of activity. All of these takes are expected to be
by Level B harassment as we believe the Level A harassment shutdown
zone can be fully implemented by PSOs because of the large size of the
animal, short dive duration, and obvious behaviors of gray whales.
Minke Whales
Minke whales have not been previously observed in the project area
but have a potential to occur. They are often solitary animals.
Therefore, we conservatively propose to authorize a single take of
minke whales. This one estimated take is expected to be by Level B
harassment as we believe the Level A shutdown zones can be fully
implemented by PSOs because of the large size of the animal, the short
dive duration, and obvious behaviors of minke whales.
Northern Elephant Seals
Members of the California breeding stock spend most of their time
at sea and are known to migrate to the Gulf of Alaska to feed on
benthic prey. Recent anecdotal evidence has suggested that an animal
may be present near Base Ketchikan and repeated sightings of that
individual have been spotted near Ketchikan docks. Elephant seals are
known to dive for extended periods of time and it is possible that one
individual may be encountered within the Level B harassment zone.
Therefore one estimated take by Level B harassment per day is proposed
to be authorized, bring the total proposed authorized take of Elephant
seals to 30. We believe the entire Level A shutdown zone can be fully
implemented given their large size and obvious behaviors of elephant
seals.
Humpback Whales
Members of the Western North Pacific stock have the potential to
occur at Base Ketchikan. Previous construction project monitoring in
the Ketchikan area reported approximately 0.571 whales per day during
those activities (NMFS, 2021). Therefore, we estimate total take at
0.571 whales per day x 30 days = 17 takes by Level B harassment only.
We do not anticipate any takes by Level A harassment as we believe the
Level A shutdown zone can be fully implemented by PSOs because of their
larger size, short dive duration, and obvious behaviors of humpback
whales.
Given data in Wade et al., (2021) discussed above on the relative
frequencies of the Hawaii and Mexico DPS humpback whales in the project
area, only 2 percent of the local population is expected to comprise of
the Mexico DPS, equating to 0.34 of the 17 humpback whale takes
proposed for authorization. Therefore, no takes of Mexico DPS whales
are expected to occur.
Table 7--Proposed Authorized Amount of Taking
----------------------------------------------------------------------------------------------------------------
Percent of
Species Stock Level A Level B Total stock
----------------------------------------------------------------------------------------------------------------
Humpback whale................ Central North 0 17 17 0.17
Pacific.
Minke whale................... Alaska.......... 0 1 1 N/A
Killer whale.................. Alaska Resident. 0 12 12 0.51
Northern 3.97
Resident.
West Coast 3.44
Transient.
Pacific-white sided dolphin... North Pacific... 0 86 86 0.32
Harbor porpoise............... Southeast Alaska 5 10 15 0.13
Dall's porpoise............... Alaska Stock.... 20 40 60 0.46
Gray whale.................... Eastern North 0 2 2 0.01
Pacific.
Harbor seal................... Clarence Strait. 10 340 360 1.30
Northern Elephant Seal........ California 0 30 30 0.00
Breeding Stock.
Steller sea lion.............. Eastern......... 0 300 300 0.69
----------------------------------------------------------------------------------------------------------------
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. 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, we
carefully consider 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, as
well as subsistence uses. 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, impact on
operations, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
To ensure no take of any ESA listed whales, there are a number of
mitigation measures proposed by USCG that go beyond, or are in addition
to, typical mitigation measures we would
[[Page 30911]]
otherwise require for this project, as determined through informal ESA
Section 7 consultation. The mitigation measures are proposed in the
IHA:
<bullet> Avoid direct physical interaction with marine mammals
during construction activity. If a marine mammal comes within 10 m of
such activity, operations must cease and vessels must reduce speed to
the minimum level required to maintain steerage and safe working
conditions (note that NMFS expects that a 10 m shutdown zone is
sufficient to avoid direct physical interaction with marine mammals,
but USCG has conservatively proposed a 20 m shutdown zone to avoid
physical interaction for in-water activities);
<bullet> Ensure that construction supervisors and crews, the
monitoring team, and relevant USCG staff are trained prior to the start
of all pile driving and DTH activity, so that responsibilities,
communication procedures, monitoring protocols, and operational
procedures are clearly understood. New personnel joining during the
project must be trained prior to commencing work;
<bullet> Pile driving activity must be halted upon observation of
either a species for which incidental take is not authorized or a
species for which incidental take has been authorized but the
authorized number of takes has been met, entering or within the
harassment zone;
<bullet> For any marine mammal species for which take by Level B
harassment has not been requested or authorized, in-water pile
installation/removal and DTH will shut down immediately when the
animals are sighted;
<bullet> Employ a minimum of three PSOs for all DTH and pile
driving activities, where one PSO is assigned to the active pile
driving or DTH site to monitor shutdown zones and as much of the Level
B harassment zones as possible. Two additional PSOs are required to
start at the project site and travel along the Tongass Narrows,
counting all humpback whales present, until they have reached the edge
of the respective Level B harassment zone. At this point, the PSOs will
identify suitable observation points from which to observe the width of
Tongass Narrows for the duration of DTH and pile driving activities.
For the largest zones, these are expected to be on South Tongass
Highway near Mountain Point and North Tongass Highway just northwest of
the intersection with Carlanna Creek.
<bullet> The placement of the PSOs during all pile driving and
removal and DTH activities will ensure that the entire shutdown zone is
visible during activity;
<bullet> Monitoring must take place from 30 minutes prior to
initiation of pile driving or DTH activity (i.e., pre-clearance
monitoring) through 30 minutes post-completion of pile driving or DTH
activity;
<bullet> If in-water work ceases for more than 30 minutes, USCG
will conduct pre-clearance monitoring of both the Level B harassment
zone and the shutdown zone;
<bullet> Pre-start clearance monitoring must be conducted during
periods of visibility sufficient for the lead PSO to determine that the
shutdown zones indicated in Table 8 are clear of marine mammals. Pile
driving and DTH may commence following 30 minutes of observation when
the determination is made that the shutdown zones are clear of marine
mammals;
<bullet> If a marine mammal is observed entering or within the
shutdown zones indicated in Table 8, pile driving and DTH must be
delayed or halted. If pile driving is delayed or halted due to the
presence of a marine mammal, the activity may not commence or resume
until either the animal has voluntarily exited and been visually
confirmed beyond the shutdown zone (Table 8) or 15 minutes have passed
without re-detection of the animal (30 minutes for large cetaceans);
<bullet> For humpback whales, if the boundaries of the harassment
zone have not been monitored continuously during a work stoppage, the
entire harassment zone will be surveyed again to ensure that no
humpback whales have entered the harassment zone that were not
previously accounted for; and
<bullet> In water activities will take place only: Between civil
dawn and civil dusk when PSOs can effectively monitor for the presence
of marine mammals; during conditions with a Beaufort Sea State of 4 or
less; when the entire shutdown zone and adjacent waters are visible
(e.g., monitoring effectiveness in not reduced due to rain, fog, snow,
etc.). Pile driving may continue for up to 30 minutes after sunset
during evening civil twilight, as necessary to secure a pile for safety
prior to demobilization during this time. The length of the post-
activity monitoring period may be reduced if darkness precludes
visibility of the shutdown and monitoring zones.
The following specific mitigation measures will also apply to
USCG's in-water construction activities:
Establishment of Level A Harassment and Shutdown Zones--For all
pile driving/removal and DTH activities, USCG will establish a shutdown
zone (Table 8). The purpose of a shutdown zone is generally to define
an area within which shutdown of activity would occur upon sighting of
marine mammal (or in anticipation of an animal entering the defined
area). Shutdown zones vary based on activity type and duration and
marine mammal hearing group (Table 8). All shutdown zones are based on
the Level A harassment isopleth for the associated activity. The
placement of PSOs during all construction activities (described in
detail in the Proposed Monitoring and Reporting Section) will ensure
that the entire shutdown zones are visible during pile installation.
Table 8--Proposed Shutdown Zones and Level B Harassment Isopleths
----------------------------------------------------------------------------------------------------------------
Shutdown zone (m)
----------------------------------------------------------------- Level B
Activity Low- Mid- High- harassment
frequency frequency frequency Phocid Otariid zone (m)
----------------------------------------------------------------------------------------------------------------
Vibratory......................... 20 20 20 20 20 13,594
DTH............................... 440 20 520 240 20 6,310
Impact............................ 30 20 30 20 20 1,848
----------------------------------------------------------------------------------------------------------------
Based on our evaluation of the applicant's proposed measures, as
well as other measures considered by NMFS, NMFS has preliminarily
determined that the proposed mitigation measures provide the means
effecting the least practicable impact on the affected species or
stocks and their habitat, paying particular attention to rookeries,
mating grounds, and areas of similar significance.
[[Page 30912]]
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 in the
proposed action area. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density).
<bullet> Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the 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).
<bullet> Mitigation and monitoring effectiveness.
Visual Monitoring
Monitoring must be conducted by qualified, NMFS-approved PSOs, in
accordance to the following:
<bullet> PSOs must be independent (i.e., not construction
personnel) and have no other assigned tasks during monitoring periods.
At least one PSO must have prior experience performing the duties of a
PSO during construction activities pursuant to a NMFS-issued IHA. Other
PSOs may substitute other relevant experience, education (degree in
biological science or related field), or training for prior experience
performing the duties of a PSO during construction activity pursuant to
a NMFS-issued IHA. Where a team of three or more PSOs is required, a
lead observer or monitoring coordinator must be designated. The lead
observer must have prior experience performing the duties of a PSO
during construction activity pursuant to a NMFS-issued incidental take
authorization. PSOs must be approved by NMFS prior to beginning any
activity subject to this IHA; and
<bullet> PSOs must record all observations of marine mammals
regardless of distance from the pile being driven. PSOs shall document
any behavioral reactions in concert with distance from piles being
driven or removed.
PSOs must have the following additional qualifications:
<bullet> Ability to conduct field observations and collect data
according to assigned protocols;
<bullet> Experience or training in the field identification of
marine mammals, including the identification of behaviors;
<bullet> Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
<bullet> Writing skills sufficient to prepare a report of
observations including but not limited to the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates, times and reason for implementation
of mitigation (or why mitigation was not implemented when required);
and marine mammal behavior; and
<bullet> Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary.
USCG must employ three PSOs during all pile driving and DTH
activities. A minimum of one PSO (the lead PSO) must be assigned to the
active pile driving or DTH location to monitor the shutdown zones and
as much of the Level B harassment zones as possible. Two additional
PSOs are also required. The additional PSOs will start at the project
site and travel along Tongass Narrows, counting all humpback whales
present, until they have reached the edge of the respective Level B
harassment zone. At this point, the PSOs will identify suitable
observation points from which to observe the width of Tongass Narrows
for the duration of DTH and pile driving activities. For the largest
zones, these are expected to be on the South Tongass Highway near
Mountain Point and north Tongass Highway just northwest of the
intersection with Carlanna Creek. If visibility deteriorates so that
the entire width of Tongass Narrows at the harassment zone boundary is
not visible, additional PSOs may be positioned so that the entire width
is visible, or work will be halted until the entire width is visible to
ensure that any humpback whales entering or are within the harassment
zone are detected by PSOs.
Reporting
A draft marine mammal monitoring report will be submitted to NMFS
within 90 days after the completion of pile driving and removal
activities, or 60 days prior to a requested date of issuance from any
future IHAs for projects at the same location, whichever comes first.
The report will include an overall description of work completed, a
narrative regarding marine mammal sightings, and associated PSO data
sheets. Specifically, the report must include:
<bullet> Dates and times (begin and end) of all marine mammal
monitoring;
<bullet> Construction activities occurring during each daily
observation period, including the number and type of piles driven or
removed and by what method (i.e., impact, vibratory or DTH) and the
total equipment duration for vibratory removal or DTH for each pile or
hole or total number of strikes for each pile (impact driving);
<bullet> PSO locations during marine mammal monitoring;
<bullet> Environmental conditions during monitoring periods (at
beginning and end of PSO shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance;
<bullet> Upon observation of a marine mammal, the following
information: Name of PSO who sighted the animal(s) and PSO location and
activity at the time of sighting; Time of sighting; Identification of
the animal(s) (e.g., genus/species, lowest possible taxonomic level, or
unidentifiable), PSO confidence in identification, and the composition
of the group if there is a mix of species; Distance and bearing of each
marine mammal observed relative to the pile being driven for each
sightings (if pile driving was occurring
[[Page 30913]]
at time of sighting); Estimated number of animals (min/max/best
estimate); Estimated number of animals by cohort (adults, juveniles,
neonates, group composition, sex class, etc.); Animal's closest point
of approach and estimated time spent within the harassment zone;
Description of any marine mammal behavioral observations (e.g.,
observed behaviors such as feeding or traveling), including an
assessment of behavioral responses thought to have resulted from the
activity (e.g., no response or changes in behavioral state such as
ceasing feeding, changing direction, flushing, or breaching);
<bullet> Number of marine mammals detected within the harassment
zones and shutdown zones; by species;
<bullet> Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensured, and resulting changes in behavior of the
animal(s), if any; and
<bullet> If visibility degrades to where PSO(s) cannot view the
entire harassment zones, additional PSOs may be positioned so that the
entire width is visible, or work will be halted until the entire width
is visible to ensure that any humpback whales entering or within the
harassment zone are detected by PSOs.
If no comments are received from NMFS within 30 days, the draft
final report will constitute the final report. If comments are
received, a final report addressing NMFS comments must be submitted
within 30 days after receipt of comments.
Reporting Injured or Dead Marine Mammals
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, the IHA-holder must
immediately cease the specified activities and report the incident to
the Office of Protected Resources (OPR)
(<a href="/cdn-cgi/l/email-protection#c19193ef889591ef8caeafa8b5aeb3a8afa693a4b1aeb3b5b281afaea0a0efa6aeb7"><span class="__cf_email__" data-cfemail="6434364a2d30344a290b0a0d100b160d0a033601140b161017240a0b05054a030b12">[email protected]</span></a>), NMFS and to the Alaska Regional
Stranding Coordinator as soon as feasible. If the death or injury was
clearly caused by the specified activity, USCG must immediately cease
the specified activities until NMFS is able to review the circumstances
of the incident and determine what, if any, additional measures are
appropriate to ensure compliance with the terms of the IHA. The IHA-
holder must not resume their activities until notified by NMFS. The
report must include the following information:
<bullet> Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
<bullet> Species identification (if known) or description of the
animal(s) involved;
<bullet> Condition of the animal(s) (including carcass condition if
the animal is dead);
<bullet> Observed behaviors of the animal(s), if alive;
<bullet> If available, photographs or video footage of the
animal(s); and
<bullet> General circumstances under which the animal was
discovered.
Negligible Impact Analysis and Determination
NMFS has defined negligible impact as an impact resulting from the
specified activity that cannot be reasonably expected to, and is not
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
``taken'' through harassment, NMFS considers other factors, such as the
likely nature of any responses (e.g., intensity, duration), the context
of any responses (e.g., critical reproductive time or location,
migration), 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's 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 environmental baseline (e.g., as
reflected in the regulatory status of the species, population size and
growth rate where known, ongoing sources of human-caused mortality, or
ambient noise levels).
To avoid repetition, our analysis applies to all species listed in
Table 2 for which take could occur, given that NMFS expects the
anticipated effects of the proposed pile driving/removal and DTH on
different marine mammal stocks to be similar in nature. Where there are
meaningful differences between species or stocks, or groups of species,
in anticipated individual responses to activities, impact of expected
take on the population due to differences in population status, or
impacts on habitat, NMFS has identified species-specific factors to
inform the analysis.
Pile driving and DTH activities associated with the project, as
outlined previously, have the potential to disturb or displace marine
mammals. Specifically, the specified activities may result in take, in
the form of Level B harassment and, for some species, Level A
harassment from underwater sounds generated by pile driving. Potential
takes could occur if individuals are present in the ensonified zone
when these activities are underway.
The Level A harassment zones identified in Table 6 are based upon
an animal exposed to impact pile driving or DTH up to two piles per
day. Given the short duration to impact drive or vibe, or use DTH
drilling, each pile and break between pile installations (to reset
equipment and move piles into place), an animal would have to remain
within the area estimated to be ensonified above the Level A harassment
threshold for multiple hours. This is highly unlikely give marine
mammal movement in the area. If an animal was exposed to accumulated
sound energy, the resulting PTS would likely be small (e.g., PTS onset)
at lower frequencies where pile driving energy is concentrated, and
unlikely to result in impacts to individual fitness, reproduction, or
survival.
The nature of the pile driving project precludes the likelihood of
serious injury or mortality. For all species and stock, take would
occur within a limited, confined area (adjacent to the project site) of
the stock's range. Level A and Level B harassment will be reduced to
the level of least practicable adverse impact through use of mitigation
measures described herein. Further, the amount of take proposed to be
authorized is extremely small when compared to stock abundance.
Behavioral responses of marine mammals to pile driving, pile
removals, and DTH at the sites in Tongass Narrows are expected to be
mild, short term, and temporary. Marine mammals within the Level B
harassment zones may not show any visual cues they are disturbed by
activities or they could become alert, avoid the area, leave the area,
or display other mild responses that are not observable such as changes
in vocalization patterns. Given that pile driving, pile removal and DTH
would occur for only a portion of the project's duration, any
harassment occurring would be temporary. Additionally, many of the
species present in region would only be present temporarily based on
seasonal patterns or during transit between other habitats. These
temporary present species would be
[[Page 30914]]
exposed to even smaller periods of noise-generating activity, further
decreasing the impacts.
For all species except humpback whales, there are no known
Biologically Important Areas (BIAs) near the project area that would be
impacted by USCG's planned activities. For humpback whales, the whole
Southeast of Alaska is a seasonal BIA from March through November
(Ferguson et al., 2015), however, Tongass Narrows and the Clarence
Strait are not important portions of this habitat due to human
development and presence. The Tongass Narrows is also a small
passageway and represents a very small portion of the total available
habitat. In addition, while the southeast Alaska is considered an
important area for feeding humpback whales between March and May
(Ellison et al., 2012), it is not currently designated as critical
habitat for humpback whales (86 FR 21082; April 21, 2021).
In addition, it is unlikely that minor noise effects in a small,
localized area of habitat would have any effect on each stock's ability
to recover. In combination, we believe that these factors, as well as
the available body of evidence from other similar activities,
demonstrate that the potential effects of the specified activities will
have only minor, short-term effects on individuals. The specified
activities are not expected to impact rates of recruitment or survival
and will therefore not result in population-level impacts.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
this activity are not expected to adversely affect the species or stock
through effects on annual rates of recruitment or survival:
<bullet> No mortality is anticipated or authorized.
<bullet> Authorized Level A harassment would be very small amounts
and of low degree;
<bullet> The only known area of specific biological importance
covers a broad area of southeast Alaska for humpback whales, and the
project area is a very small portion of that BIA. No other known areas
of particular biological importance to any of the affected species or
stocks are impacted by the activity, including ESA-designated critical
habitat;
<bullet> For all species, the Tongass Narrows is a very small and
peripheral part of their range;
<bullet> USCG would implement mitigation measures including soft-
starts and shutdown zones to minimize the numbers of marine mammals
exposed to injurious levels of sound, and to ensure that take by Level
A harassment is, at most, a small degree of PTS;
<bullet> Monitoring reports from similar work in the Tongass
Narrows have documented little to no effect on individuals of the same
species impacted by the specified activity.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS preliminarily finds that the total marine
mammal take from the proposed activity will have a negligible impact on
all affected marine mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is fewer than one third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
The amount of take NMFS proposes to authorize is below one third of
the estimated stock abundance for all species (in fact, take of
individuals is less than five percent of the abundance of the affected
stocks, see Table 7). This is likely a conservative estimate because we
assume all takes are of different individual animals, which is likely
not the case. Some individuals may return multiple times in a day, but
PSOs would count them as separate takes if they cannot be individually
identified.
The most recent estimate for the Alaska stock of Dall's porpoise
was 13,110 animals however this number just accounts for a portion of
the stock's range. Therefore, the 60 takes of this stock proposed for
authorization is believed to be an even smaller portion of the overall
stock abundance.
Likewise, the Southeast Alaska stock of harbor porpoise has no
official NMFS abundance estimate as the most recent estimate is greater
than eight years old. The most recent estimate was 11,146 animal (Muto
et al., 2021) and it is highly unlikely this number has drastically
declined. Therefore, the 15 takes of this stock proposed for
authorization clearly represent small numbers of this stock.
There is no current or historical estimate of the Alaska minke
whale stock, but there are known to be over 1,000 minke whales in the
Gulf of Alaska (Muto et al., 2018) so the 1 take proposed for
authorization clearly represents small numbers of this stock.
Additionally, the range of the Alaska stock of minke whales is
extensive, stretching from the Canadian Pacific coast to the Chukchi
Sea, and USCG's project area impacts a very small portion of this
range. Therefore, the singular take of minke whale proposed for
authorization is small relative to estimated survey abundance, even if
each proposed take occurred to a new individual.
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 will be taken relative to the population size
of the affected species or stocks.
Unmitigable Adverse Impact Analysis and Determination
In order to issue an IHA, NMFS must find that the specified
activity will not have an ``unmitigable adverse impact'' on the
subsistence uses of the affected marine mammal species or stocks by
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50
CFR 216.103 as an impact resulting from the specified activity: (1)
That is likely to reduce the availability of the species to a level
insufficient for a harvest to meet subsistence needs by: (i) Causing
the marine mammals to abandon or avoid hunting areas; (ii) Directly
displacing subsistence users; or (iii) Placing physical barriers
between the marine mammals and the subsistence hunters; and (2) That
cannot be sufficiently mitigated by other measures to increase the
availability of marine mammals to allow subsistence needs to be met.
Alaska Native hunters in the Ketchikan vicinity do not
traditionally harvest cetaceans (Muto et al., 2021). To date, there are
no reports of subsistence takes of killer whale, Pacific white-sided
dolphin, harbor porpoise, or Dall's porpoise within Alaska (Muto et
al., 2021). Harbor seals are the most commonly targeted marine mammal
that is hunted by Alaska Native subsistence hunters within the
Ketchikan area. In 2012, an estimated 595 harbor seals were taken for
subsistence uses, with 22
[[Page 30915]]
of those occurring in Ketchikan (Wolfe et al., 2013). Statewide data
are no longer being consistently collected for subsistence harvest of
Steller sea lions, however subarea collect does occur periodically. In
2012, hunters in Southeast Alaska took an estimated nine sea lions for
subsistence use (Wolfe et al., 2013). Sea lions were taken in two
communities (Hoonah and Sitka) by three hunters. There are no known
haulout locations in the project area. Both the harbor seal and Steller
sea lion may be temporarily displaced from the action are However,
neither the local population nor any individual pinniped are likely to
be adversely impacted by the proposed action beyond noise-induced
harassment or slight injury. The proposed project is anticipated to
have no long-term impacts on either species' populations, or their
habitats. No long-term impacts on the availability of marine mammals
for subsistence uses is anticipated.
Based on the description of the specified activity, the measures
described to minimize adverse effects on the availability of marine
mammals for subsistence purposes, and the proposed mitigation and
monitoring measures, NMFS has preliminarily determined that there will
not be an unmitigable adverse impact on subsistence uses from USCG's
proposed activities.
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 Alaska Regional
Office.
No incidental take of ESA-listed species is proposed for
authorization or expected to result from this activity. Therefore, NMFS
has determined that formal consultation under section 7 of the ESA is
not required for this action.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to the United States Coast Guard for construction
associated with the floating dock extension project in Ketchikan,
Alaska, provided the previously mentioned mitigation, monitoring, and
reporting requirements are incorporated. A draft of the proposed IHA
can be found at <a href="https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act">https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</a>.
Request for Public Comments
We request comment on our analyses, the proposed authorization, and
any other aspect of this notice of proposed IHA for the U.S. Coast
Guard's construction of a floating dock at Base Ketchikan We also
request at this time comment on the potential Renewal of this proposed
IHA as described in the paragraph below. Please include with your
comments any supporting data or literature citations to help inform
decisions on the request for this IHA or a subsequent Renewal IHA.
On a case-by-case basis, NMFS may issue a one-time, 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, 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: May 16, 2022.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2022-10938 Filed 5-19-22; 8:45 am]
BILLING CODE P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on May 20, 2022.
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.