[Federal Register Volume 84, Number 41 (Friday, March 1, 2019)]
[Notices]
[Pages 7023-7041]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-03684]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XG644
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the O'Connell Bridge Lightering
Float Pile Replacement Project in Sitka, 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.
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SUMMARY: NMFS has received a request from City and Borough of Sitka
(CBS) for authorization to take marine mammals incidental to the
O'Connell Bridge Lightering Float Pile Replacement Project in Sitka,
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-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 April 1,
2019.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service. Physical comments should be sent to
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments
should be sent to [email protected].
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 received electronically, including
all attachments, must not exceed a 25-megabyte file size. Attachments
to electronic comments will be accepted in Microsoft Word or Excel or
Adobe PDF file formats only. All comments received are a part of the
public record and will generally be posted online at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. 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: Rob Pauline, Office of Protected
Resources, NMFS, and (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:
www.nmfs.noaa.gov/pr/permits/incidentalconstruction.htm. 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 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 such 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 such takings are set forth.
The NDAA (Pub. L. 108-136) removed the ``small numbers'' and
``specified geographical region'' limitations indicated above and
amended the definition of ``harassment'' as it applies to a ``military
readiness activity. 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
incidental harassment authorization) with respect to potential impacts
on the human environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 (incidental harassment authorizations 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 November 18, 2018, NMFS received a request from CBS for an IHA
to take marine mammals incidental to pile driving and removal
activities associated with the O'Connell Bridge Lightering Float Pile
Replacement Project in Sitka, Alaska. The application was deemed
adequate and complete on December 20, 2018. CBS's request is for take
of small numbers of humpback whale (Megaptera novaeangliae), killer
whale (Orcinus orca), harbor porpoise (Phocoena phocoena), harbor seal
[[Page 7024]]
(Phoca vitulina), and Steller sea lion (Eumetopias jubatus) by Level B
harassment only. Neither CBS nor NMFS expects serious injury or
mortality to result from this activity and, therefore, an IHA is
appropriate.
Description of Proposed Activity
Overview
CBS is repairing the O'Connell Bridge Lightering Float (float)
located in Sitka Sound in Southeast Alaska. The applicant proposes to
remove existing piles and replace them with piles that are more deeply
socketed so that the float can accommodate larger vessels including
yachts, fish processors, and research vessels. Existing piles are not
socketed deep enough to provide proper stability to safely support
these vessels. Additionally, the float was damaged during a storm in
June of 2017, and the existing piles are now leaning. This project
would replace the existing piles with new piles that are socketed
deeper into the ocean floor. Once the piles are replaced, the float
will safely accommodate these larger vessels. Vibratory pile removal,
vibratory pile driving, impact pile driving, and drilling would
introduce sound into nearby waters at levels that could result in
behavioral harassment of marine mammals.
Dates and Duration
Pile removal and installation is expected to occur for a total of
approximately 13 hours over 3 days. The local Sitka Tribe requested
that no pile driving occur between March 15 and May 31 to protect
herring, as has been the case for past permitting in Sitka Sound.
Therefore, and assuming weather conditions are favorable, CBS proposes
to begin pile driving work on June 1, 2019. As a contingency, CBS
requests an IHA for incidental take of marine mammals described within
this application for one year, effective from June 1, 2019 through May
31, 2020.
Specific Geographic Region
The O'Connell Bridge Lightering Float is located near the prominent
O'Connell Bridge within Crescent Bay and adjacent to Sitka Channel (see
Figures 1, 2, and 3 of CBS's application). Crescent Bay is bounded by
Sitka Channel to the northwest, Middle Channel to the southwest and
Eastern Channel to the southeast, and a series of islands to the south.
The bay is relatively shallow with a maximum depth of approximately 30
meters. The north side of the bay has riprap protected developed areas,
including a boat harbor, and undeveloped shorelines on small islands to
the south and on the eastern side of the bay. Lower intertidal and
shallow subtidal areas are primarily cobbles and boulders with varying
amounts of silt. The sediment thickness varies from 3 to 30 inches (PND
2017) until bedrock is reached. The float is located in an active
marine commercial and industrial area.
Detailed Description of Specific Activity
CBS plans to remove and replace the six piles that support the
O'Connell Bridge Lightering Float. The existing float consists of two
100-foot long by 5-foot wide aluminum gangways and a 180-foot long by
10-foot wide concrete modular float system restrained by six 16-inch
diameter steel pipe piles that are socketed 4 feet deep into bedrock.
The existing piles would be removed and replaced with six new 16-inch
diameter steel piles that would be socketed 12 feet deep into bedrock.
Pile installation and removal is expected to occur over three days.
Construction includes the following activities:
Temporarily remove the existing concrete lightering float
and associated aluminum gangways (Note: these components are removed
each winter and reinstalled in the summer.);
Remove six (6) 16-inch diameter steel pipe piles that
support the float;
Install six (6) 16-inch diameter galvanized steel pipe
piles (0.5-inch wall); and
Reinstall the floating dock and gangways.
The following equipment would be used:
Vibratory Hammer: ICE 44B/12,450 pounds static weight;
Diesel Impact Hammer: Delmar D46/Max Energy 107,280 ft.-
pounds;
Drilled shaft drill: Hole 100,000 ft-lb. top drive with
down-the-hole (DTH) hammer and bit; and
Socket drill: Whole 100,000 ft-lb. top drive with DTH
hammer and under-reamer bit.
The first step would be to remove the existing piles by direct pull
using a crane. If the direct pull method is ineffective, the piles
would be extracted with a vibratory hammer. In this case, the vibratory
hammer would be clamped onto the pile and operated while using a crane
to pull the pile upwards.
Next, the new piles would be installed. First the piles would be
vertically stabilized by being vibrated into the existing 4-foot deep
sockets. Next the piles would be socketed into the underlying bedrock
with a down-hole drill and under-reamer bit (the drill will be used
first to drill a hole in the bedrock to a depth of approximately 12
feet and then to socket the pile into the bedrock). After the pile is
socketed, the contractor may choose to impact proof the piles. In this
case, two to five blows of an impact hammer would be used per pile to
confirm that piles are set into bedrock.
Pile removal and installation are expected to occur on three days.
On the first day the existing piles would be removed, and the new piles
would be vibrated into position. Over the second and third day, the
piles would be socketed into bedrock. At the end of the third day, the
piles would be impact proofed, if necessary. Table 1 provides a
conservative estimate of the amount of time required for pile
installation and removal.
Table 1--Pile Driving Construction Summary
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Permanent pile Max installation/ removal
Existing pile removal installation per day
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Pile Diameter and Type............. 16-inch steel......... 16-inch steel.........
Number of Piles.................... 6 piles............... 6 piles...............
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Vibratory Pile Removal/Driving
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Max Number of Piles Vibrated Per 6 piles............... 6 piles............... 12 piles.
Day.
Vibratory Time Per Pile............ 5 minutes............. 5 minutes.............
Vibratory Time per day............. 30 minutes............ 30 minutes............ 60 minutes.
Vibratory Time Total............... 30 minutes............ 30 minutes............
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[[Page 7025]]
Socketing (down-hole drilling)
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Max Number of Piles Socketed per 0..................... 3 piles............... 3 piles.
Day.
Socket Time Per Pile............... 0..................... 2 hours...............
Socket Time per Day................ 0..................... 6 hours............... 6 hours.
Socket Time Total.................. 0..................... 12 hours..............
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Impact Pile Driving
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Max Number of Piles Impacted Per 0..................... 6 piles............... 6 piles.
Day.
Number of Strikes Per Pile......... 0..................... 2-5 strikes........... 30 strikes.
Impact Time Per Pile............... 0..................... 30 seconds............
Impact Time per Day................ 0..................... 3 minutes............. 3 minutes.
Impact Time Total.................. 0..................... 3 minutes.............
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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.
Additional information regarding population trends and threats may be
found in NMFS's Stock Assessment Reports (SAR; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS's
website (https://www.fisheries.noaa.gov/find-species).
Table 2 lists all species with expected potential for occurrence in
Crescent Bay and summarizes information related to the population or
stock, including regulatory status under the MMPA and ESA and potential
biological removal (PBR), where known. For taxonomy, we follow
Committee on Taxonomy (2018). 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' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS' U.S. Alaska SARs (e.g., Muto et al. 2018). All values presented
in Table 2 are the most recent available at the time of publication and
are available in the 2017 SARs (Muto et al. 2018) and draft 2018 SARs
(available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports)
Table 2--Marine Mammals Potentially Present Within Sitka Sound During the Specified Activity
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ESA/ MMPA status; Stock abundance (CV,
Common name Scientific name Stock Strategic (Y/N) NMin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
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Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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Family Balaenidae:
Humpback whale.................. Megaptera novaeangliae. Central North Pacific.. -, -, Y 10,103 (0.3, 7,891, 83 26
2006).
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Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
Killer whale.................... Orcinus orca........... Alaska Resident........ -, -, N 2,347 (N/A, 2,347, 24 1
2012) \4\.
Northern Resident...... -, -, N 261 (N/A, 261, 1.96 0
2011)\4\.
Gulf of Alaska, -, -, N 587 (N/A, 587, 2012) 5.87 1
Aleutian Islands, \4\.
Bering Sea Transient.
West Coast Transient... -, -, N 243 (N/A, 243, 2009) 2.4 0
\4\.
Family Phocoenidae (porpoises):
Harbor porpoise................. Phocoena phocoena...... Southeast Alaska....... -, -, Y 975 (0.12-0.14, 897, 8.9 34
2012) \5\.
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[[Page 7026]]
Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
sea lions):
Steller sea lion................ Eumetopias jubatus..... Western U.S............ E, D, Y 54,267 (N/A, 54,267, 326 252
2017).
Eastern U.S............ -, D, Y 41,638 (N/A, 41,638, 2498 108
2015).
Family Phocidae (earless seals):
Harbor seal..................... Phoca vitulina Sitka/................. -, -, N 14,855 (N/A, 13,212, 555 77
richardii. Chatham Strait......... 2011).
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\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable (N/A).
\3\ These values, found in NMFS' 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\ N is based on counts of individual animals identified from photo-identification catalogs.
\5\ In the SAR for harbor porpoise, NMFS identified population estimates and PBR for porpoises within inland southeast Alaska waters (these abundance
estimates have not been corrected for g(0); therefore, they are likely conservative).
Multiple additional marine mammal species may occasionally enter
Sitka sound but would not be expected to occur in shallow nearshore
waters of the action area. These include extralimital species, which
are species that do not normally occur in a given area but for which
there are one or more occurrence records that are considered beyond the
normal range of the species. Gray whales are observed in and outside of
Sitka Sound during their northward spring migration; however, they
occur generally north and west of the project area in outer shelf
waters of Sitka Sound during the summer. Similarly, minke whales in
Alaska are migratory and would be found further north during the
summer. Dall's porpoise are observed in mid- to outer-shelf coastal
waters of Sitka Sound ranging to the Gulf of Alaska and are not
expected to occur in the project area. Pacific white-sided dolphins
occur in the outer-shelf slope in the Gulf of Alaska, which is outside
of the project area. Sperm whales, fin whales and Cuvier's beaked
whales generally occur in deeper offshore waters. During eight years of
local surveys, only three gray whales and seven Pacific white sided
dolphins were observed. The sperm whale, Cuvier's beaked whale, minke
whale and Dall's porpoise were not observed (Straley et al. 2018).
Therefore, no take is requested for these species and they are not
considered further in this proposed IHA.
Cetaceans
Humpback Whale
The humpback whale is distributed worldwide in all ocean basins. In
winter, most humpback whales occur in the subtropical and tropical
waters of the Northern and Southern Hemispheres, and migrate to high
latitudes in the summer to feed. The historic summer feeding range of
humpback whales in the North Pacific encompassed coastal and inland
waters around the Pacific Rim from Point Conception, California, north
to the Gulf of Alaska and the Bering Sea, and west along the Aleutian
Islands to the Kamchatka Peninsula and into the Sea of Okhotsk and
north of the Bering Strait.
Under the MMPA, there are three stocks of humpback whales in the
North Pacific: (1) The California/Oregon/Washington and Mexico stock,
consisting of winter/spring populations in coastal Central America and
coastal Mexico which migrate to the coast of California to southern
British Columbia in summer/fall; (2) the central North Pacific stock,
consisting of winter/spring populations of the Hawaiian Islands which
migrate primarily to northern British Columbia/Southeast Alaska, the
Gulf of Alaska, and the Bering Sea/Aleutian Islands; and (3) the
western North Pacific stock, consisting of winter/spring populations
off Asia which migrate primarily to Russia and the Bering Sea/Aleutian
Islands. The central North Pacific stock is the only stock that is
found near the project activities.
On September 8, 2016, NMFS published a final rule dividing the
globally listed endangered species into 14 Distinct Population Segments
(DPS), removing the worldwide species-level listing, and in its place
listing four DPSs as endangered and one DPS as threatened (81 FR 62259;
effective October 11, 2016). Two DPSs (Hawaii and Mexico) are
potentially present within the action area. The Hawaii DPS is not
listed and the Mexico DPS is listed as threatened under the ESA. The
Hawaii DPS is estimated to contain 11,398 animals where the Mexico DPS
is estimated to contain 3,264 animals (Wade et al. 2016).
Humpback whales are known to undertake seasonal migrations from
their tropical calving and breeding grounds in winter to their high-
latitude feeding grounds in summer. However, they have been observed in
Southeast Alaska in all months of the year. Humpback whales are most
common in Sitka Sound's Eastern Channel in November, December, and
January (Straley et al. 2018). In late fall and winter, herring
sometimes overwinter in deep fjords in Silver Bay and Eastern Channel,
and humpback whales aggregate in these areas to feed on them. At some
point in the late winter, it is likely that whales migrate south across
the North Pacific to their mating and calving grounds in Hawaii and
Mexico; however, this likely occurs after herring have moved out of the
fjords. In the summer when prey is dispersed throughout Sitka Sound,
humpback whales also disperse throughout the
[[Page 7027]]
Sound and away from the project area (Straley 2017).
Killer Whale
Killer whales have been observed in all oceans and seas of the
world, but the highest densities occur in colder and more productive
waters found at high latitudes. Killer whales are found throughout the
North Pacific, and occur along the entire Alaska coast, in British
Columbia and Washington inland waterways, and along the outer coasts of
Washington, Oregon, and California (Muto et al. 2017).
Based on data regarding association patterns, acoustics, movements,
and genetic differences, eight killer whale stocks are now recognized:
(1) The Alaska Resident stock; (2) the Northern Resident stock; (3) the
Southern Resident stock; (4) the Gulf of Alaska, Aleutian Islands, and
Bering Sea Transient stock; (5) the AT1 Transient stock; (6) the West
Coast transient stock, occurring from California through southeastern
Alaska; and (7) the Offshore stock, and (8) the Hawaiian stock. Only
the Alaska resident; Northern resident; Gulf of Alaska, Aleutian
Islands, and Bering Sea Transient (Gulf of Alaska transient); and the
West coast transient stocks are considered in this application because
other stocks occur outside the geographic area under consideration. Any
of these four stocks could occur in the action area.
Local observational data by Straley (2017) demonstrated that
transient killer whales, primarily from the West Coast transient stock,
occur most frequently in the project area. Less often, whales from the
Eastern North Pacific Gulf of Alaska, Aleutian Islands, and Bering Sea
transient stock occur in the project area. Because of their transient
nature, it is difficult to predict when killer whales will be present
in the area. Whales from the Alaska resident stock and the Northern
resident stock primarily feed on fish and do occur in Southeast Alaska;
however, they are rare in the project area (Straley 2017).
Harbor Porpoise
The harbor porpoise inhabits temperate, subarctic, and arctic
waters. In the eastern North Pacific, harbor porpoises range from Point
Barrow, Alaska, to Point Conception, California. Harbor porpoise
primarily frequent coastal waters and occur most frequently in waters
less than 100 m deep (Hobbs and Waite 2010). They may occasionally be
found in deeper offshore waters.
In Alaska, harbor porpoises are currently divided into three
stocks, based primarily on geography: (1) The Southeast Alaska stock--
occurring from the northern border of British Columbia to Cape
Suckling, Alaska, (2) the Gulf of Alaska stock--occurring from Cape
Suckling to Unimak Pass, and (3) the Bering Sea stock--occurring
throughout the Aleutian Islands and all waters north of Unimak Pass.
Only the Southeast Alaska stock is considered in this application
because the other stocks are not found in the geographic area under
consideration.
Harbor porpoises commonly frequent nearshore waters, but are not
common in the project vicinity. Monthly observation from Sitka's Whale
Park show harbor porpoises occurring infrequently in or near the action
area in March, April, and October between 1994 to 2002 (Straley et al.
2018). Meanwhile, no harbor porpoises have been observed more recently
during monitoring (Windward 2017 and Turnagain 2017, Turnagain 2018).
Pinnipeds
Steller Sea Lion
The Steller sea lion is the largest of the eared seals, ranging
along the North Pacific Rim from northern Japan to California, with
centers of abundance and distribution in the Gulf of Alaska and
Aleutian Islands. Steller sea lions were listed as threatened range-
wide under the ESA on November 26, 1990 (55 FR 49204). Subsequently,
NMFS published a final rule designating critical habitat for the
species as a 20 nautical mile buffer around all major haulouts and
rookeries, as well as associated terrestrial, air and aquatic zones,
and three large offshore foraging areas (58 FR 45269; August 27, 1993).
In 1997, NMFS reclassified Steller sea lions into two DPSs based on
genetic studies and other information (62 FR 24345; May 5, 1997).
Steller sea lion populations that primarily occur west of 144[deg] W.
(Cape Suckling, Alaska) comprise the western DPS (wDPS), while all
others comprise the eastern DPS (eDPS); however, there is regular
movement of both DPSs across this boundary (Jemison et al. 2013). Upon
this reclassification, the wDPS became listed as endangered while the
eDPS remained as threatened (62 FR 24345; May 5, 1997). In November
2013, the eDPS was delisted (78 FR 66140). Based on recent observations
of branded animals in Southeast Alaska, NMFS estimates that 98 percent
of Steller sea lions occurring within the action area belong to the
eDPS, leaving 2 percent to the wDPS (Suzie Teerlink, pers. comm, May
19, 2017).
Steller sea lions are common in the inside waters of southeastern
Alaska and are common in the vicinity of the project and both Eastern
DPS and Western DPS species are thought to be within Sitka Sound.
Steller sea lions were seen during every month of monitoring (September
to May) between 1994 and 2002 (Straley et al. 2018).
Because the action area contains a herring processing plant,
animals may linger in the area to feed opportunistically. Anecdotal
evidence from staff at the fish processing plant indicate that multiple
(up to 10) Steller sea lions may reside in the area for multiple days
(Straley et al. 2018).
The project action area does not overlap Steller sea lion critical
habitat. The Biorka Island haulout is the closest designated critical
habitat and is over 25 kilometers southwest of the project area.
Steller sea lions also haul out on buoys and navigational markers in
Sitka Sound and along the rocky shores of Sugarloaf south of the
project site. However, these haulouts are far beyond the expected
extent of in-water and in-air noise disturbance thresholds for hauled
out pinnipeds.
Harbor Seal
Harbor seals range from Baja California north along the coasts of
Washington, Oregon, California, British Columbia, and Southeast Alaska;
west through the Gulf of Alaska, Prince William Sound, and the Aleutian
Islands; and north in the Bering Sea to Cape Newenham and the Pribilof
Islands. They haul out on rocks, reefs, beaches, and drifting glacial
ice, and feed in marine, estuarine, and occasionally fresh waters.
Harbor seals are generally non-migratory, with local movements
associated with such factors as tides, weather, season, food
availability, and reproduction.
Harbor seals in Alaska are partitioned into 12 separate stocks
based largely on genetic structure: (1) The Aleutian Islands stock, (2)
the Pribilof Islands stock, (3) the Bristol Bay stock, (4) the North
Kodiak stock, (5) the South Kodiak stock, (6) the Prince William Sound
stock, (7) the Cook Inlet/Shelikof stock, (8) the Glacier Bay/Icy
Strait stock, (9) the Lynn Canal/Stephens Passage stock, (10) the
Sitka/Chatham stock, (11) the Dixon/Cape Decision stock, and (12) the
Clarence Strait stock. Only the Sitka/Chatham stock is considered in
this proposed IHA. The range of this stock includes Cape Bingham south
to Cape Ommaney and the adjacent coastal and inshore waters, including
the project area.
Harbor seals are common in the inside waters of southeastern
Alaska, including
[[Page 7028]]
in the vicinity of the O'Connell Bridge Lightering Float. The species
were seen during most months of monitoring (September through May) from
observation from the Sitka Whale Park between 1994 and 2002, except in
December and May (Straley et al. 2018). Harbor seals were also commonly
observed at nearby locations according to recent monitoring reports
(Turnagain 2017 and Windward 2017, Turnagain 2018). Similar to Steller
sea lions, harbor seals may linger in the action area for multiple
days; however, no designated haulouts are within close proximity.
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 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. The functional groups and the associated
frequencies are indicated below (note that these frequency ranges
correspond to the range for the composite group, with the entire range
not necessarily reflecting the capabilities of every species within
that group):
Low-frequency cetaceans (mysticetes): Generalized hearing
is estimated to occur between approximately 7 Hz and 35 kHz;
Mid-frequency cetaceans (larger toothed whales, beaked
whales, and most delphinids): Generalized hearing is estimated to occur
between approximately 150 Hz and 160 kHz;
High-frequency cetaceans (porpoises, river dolphins, and
members of the genera Kogia and Cephalorhynchus; including two members
of the genus Lagenorhynchus, on the basis of recent echolocation data
and genetic data): Generalized hearing is estimated to occur between
approximately 275 Hz and 160 kHz.
Pinnipeds in water; Phocidae (true seals): Generalized
hearing is estimated to occur between approximately 50 Hz to 86 kHz;
Pinnipeds in water; Otariidae (eared seals): Generalized
hearing is estimated to occur between 60 Hz and 39 kHz.
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.
Five marine mammal species (three cetacean and two pinniped (one
otariid and one phocid) species) have the reasonable potential to co-
occur with the proposed survey activities. Of the cetacean species that
may be present, one is classified as a low-frequency cetacean (i.e.,
humpback whale), one is classified as a mid-frequency cetacean (i.e.,
killer whale), and one is classified as a high-frequency cetacean
(i.e., harbor porpoise).
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 by Incidental Harassment 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 by Incidental Harassment
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.
Description of Sound Sources
The marine soundscape is comprised of both ambient and
anthropogenic sounds. Ambient sound is defined as the all-encompassing
sound in a given place and is usually a composite of sound from many
sources both near and far. The sound level of an area is defined by the
total acoustical energy being generated by known and unknown sources.
These sources may include physical (e.g., waves, wind, precipitation,
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced
by marine mammals, fish, and invertebrates), and anthropogenic sound
(e.g., vessels, dredging, aircraft, construction).
The sum of the various natural and anthropogenic sound sources at
any given location and time--which comprise ``ambient'' or
``background'' sound--depends not only on the source levels (as
determined by current weather conditions and levels of biological and
shipping activity) but also on the ability of sound to propagate
through the environment. In turn, sound propagation is dependent on the
spatially and temporally varying properties of the water column and sea
floor, and is frequency-dependent. As a result of the dependence on a
large number of varying factors, ambient sound levels can be expected
to vary widely over both coarse and fine spatial and temporal scales.
Sound levels at a given frequency and location can vary by 10-20 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 impact pile driving, vibratory pile driving and removal, 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 2018). Non-impulsive sounds (e.g.
aircraft, machinery operations such as drilling or dredging, vibratory
pile driving, and active sonar systems) can be broadband, narrowband or
tonal, brief or prolonged (continuous or intermittent), and typically
do not have the high peak sound pressure with raid
[[Page 7029]]
rise/decay time that impulsive sounds do (ANSI 1995; NIOSH 1998; NMFS
2018). The distinction between these two sound types is important
because they have differing potential to cause physical effects,
particularly with regard to hearing (e.g., Ward 1997 in Southall et al.
2007).
Two types of pile hammers would be used on this project: Impact and
vibratory. 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 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).
Drilling would be conducted using a down-the-hole drill inserted
through the hollow steel piles. A down-the-hole drill is a drill bit
that drills through the bedrock using an impact mechanism that
functions at the bottom of the hole. This breaks up rock to allow
removal of debris and insertion of the pile. The head extends so that
the drilling takes place below the pile. The sounds produced by the
down-the-hole drilling method are considered continuous as the noise
from the drilling component is dominant. In addition, this method
likely increases sound attenuation because the noise is primarily
contained within the steel pile and below ground rather than impact
hammer driving methods which occur at the top of the pile and introduce
sound into the water column to a greater degree.
The likely or possible impacts of CBS's proposed activity on marine
mammals could involve both non-acoustic and acoustic stressors.
Potential non-acoustic stressors could result from the physical
presence of the equipment and personnel; however, any impacts to marine
mammals are expected to primarily be acoustic in nature. Acoustic
stressors include effects of heavy equipment operation during pile
installation and removal and drilling.
Acoustic Impacts
The introduction of anthropogenic noise into the aquatic
environment from pile driving and removal and down-the-hole drilling is
the primary means by which marine mammals may be harassed from CBS'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 and 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 and 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 dB. A TS can be permanent
or temporary. As described in NMFS (2018), there are numerous factors
to consider when examining the consequence of TS, including, but not
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), likelihood an individual would be exposed for a long enough
duration or to a high enough level to induce a TS, the magnitude of the
TS, time to recovery (seconds to minutes or hours to days), the
frequency range of the exposure (i.e., spectral content), the hearing
and vocalization frequency range of the exposed species relative to the
signal's frequency spectrum (i.e., how animal uses sound within the
frequency band of the signal; e.g., Kastelein et al. 2014), and the
overlap between the animal and the source (e.g., spatial, temporal, and
spectral).
Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent,
irreversible increase in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS 2018). Available data from
humans and other terrestrial mammals indicate that a 40 dB threshold
shift approximates PTS onset (see Ward et al. 1958, 1959; Ward 1960;
Kryter et al. 1966; Miller 1974; Ahroon et al. 1996; Henderson et al.
2008). PTS levels for marine mammals are estimates, 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)--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 through the open ocean, where ambient noise is lower and
there are not as many competing sounds present.
[[Page 7030]]
Alternatively, a larger amount and longer duration of TTS sustained
during time when communication is critical for successful mother/calf
interactions could have more serious impacts. We note that reduced
hearing sensitivity as a simple function of aging has been observed in
marine mammals, as well as humans and other taxa (Southall et al.
2007), so we can infer that strategies exist for coping with this
condition to some degree, though likely not without cost.
Currently, TTS data only exist for four species of cetaceans
(bottlenose dolphin (Tursiops truncatus), 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
requires a combination of impact pile driving, vibratory pile driving,
and down-the-hole drilling. For the project, these activities would not
occur at the same time and there would likely be pauses in activities
producing the sound during each day. Given these pauses and that many
marine mammals are likely moving through the action area and not
remaining for extended periods of time, the potential for TS declines.
Behavioral Harassment--Exposure to noise from pile driving and
removal and drilling 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.
In 2016, the Alaska Department of Transportation and Public
Facilities (ADOT&PF) documented observations of marine mammals during
construction activities (i.e., pile driving and down-hole drilling) at
the Kodiak Ferry Dock (see 80 FR 60636 for Final IHA Federal Register
notice). In the marine mammal monitoring report for that project (ABR
2016), 1,281 Steller sea lions were observed within the Level B
disturbance zone during pile driving or drilling (i.e., documented as
Level B harassment take). Of these, 19 individuals demonstrated an
alert behavior, 7 were fleeing, and 19 swam away from the project site.
All other animals (98 percent) were engaged in activities such as
milling, foraging, or fighting and did not change their behavior. In
addition, two sea lions approached within 20 meters of active vibratory
pile driving activities. Three harbor seals were observed within the
disturbance zone during pile driving activities; none of them displayed
disturbance behaviors. Fifteen killer whales and three harbor porpoise
were also observed within the Level B harassment zone during pile
driving. The killer whales were travelling or milling while all harbor
porpoises were travelling. No signs of disturbance were noted for
either of these species. Given the similarities in activities and
habitat and the fact the same species are involved, we expect similar
behavioral responses of marine mammals to the specified activity. That
is, disturbance, if any, is likely to be temporary and localized (e.g.,
small area movements). Monitoring reports from other recent pile
driving and down-the-hole drilling projects in Alaska have observed
similar behaviors (for example, the Biorka Island Dock Replacement
Project).
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.,
[[Page 7031]]
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--Pinnipeds that occur near the project
site could be exposed to airborne sounds associated with pile driving
and removal and down-the-hole drilling that have the potential to cause
behavioral harassment, depending on their distance from pile driving
activities. Cetaceans are not expected to be exposed to airborne sounds
that would result in harassment as defined under the MMPA.
Airborne noise would primarily be an issue for pinnipeds that are
swimming or hauled out near the project site within the range of noise
levels elevated above the acoustic criteria. We recognize that
pinnipeds in the water could be exposed to airborne sound that may
result in behavioral harassment when looking with their heads above
water. Most likely, airborne sound would cause behavioral responses
similar to those discussed above in relation to underwater sound. For
instance, anthropogenic sound could cause hauled-out pinnipeds to
exhibit changes in their normal behavior, such as reduction in
vocalizations, or cause them to temporarily abandon the area and move
further from the source. However, these animals would previously have
been `taken' because of exposure to underwater sound above the
behavioral harassment thresholds, which are in all cases larger than
those associated with airborne sound. Thus, the behavioral harassment
of these animals is already accounted for in these estimates of
potential take. Therefore, we do not believe that authorization of
incidental take resulting from airborne sound for pinnipeds is
warranted, and airborne sound is not discussed further here.
Marine Mammal Habitat Effects
CBS construction activities at the O'Connell Bridge lightering
float could have localized, temporary impacts on marine mammal habitat
and their prey by increasing in-water sound pressure levels and
slightly decreasing water quality. Increased noise levels may affect
acoustic habitat (see masking discussion above) and adversely affect
marine mammal prey in the vicinity of the project area (see discussion
below). During impact pile driving, elevated levels of underwater noise
would ensonify a portion of Sitka Sound where both fish and mammals
occur and could affect foraging success.
Construction activities are of short duration and would likely have
temporary impacts on marine mammal habitat through increases in
underwater and airborne sound. These sounds would not be detectable at
the nearest known Steller sea lion haulouts, and all known harbor seal
haulouts are well beyond the maximum distance of predicted in-air
acoustical disturbance.
In-water pile driving, pile removal, and drilling activities would
also cause short-term effects on water quality due to increased
turbidity. Local strong currents are anticipated to disburse suspended
sediments produced by project activities at moderate to rapid rates
depending on tidal stage. CBS would employ standard construction best
management practices, thereby reducing any impacts. Therefore, the
impact from increased turbidity levels is expected to be discountable.
In-Water Construction Effects on Potential Foraging Habitat
The area likely impacted by the project is relatively small
compared to the available habitat in Crescent Bay and Sitka Sound and
does not include any BIAs or ESA-designated critical habitat. Pile
installation/removal and drilling may temporarily increase turbidity
resulting from suspended sediments. Any increases would be temporary,
localized, and minimal. CBS must comply with state water quality
standards during these operations by limiting the extent of turbidity
to the immediate project area. In general, turbidity associated with
pile installation is localized to about a 25-foot radius around the
pile (Everitt et al. 1980). Cetaceans are not expected to be close
enough to the project pile driving areas to experience effects of
turbidity, and any pinnipeds would be transiting the area and could
avoid localized areas of turbidity. Therefore, the impact from
increased turbidity levels is expected to be discountable to marine
mammals. Furthermore, pile driving and removal 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 in Crescent Bay
and Sitka Sound.
The duration of the construction activities is relatively short.
The construction window is for a maximum of 3 days during daylight
hours only. Impacts to habitat and prey are expected to be minimal
based on the short duration of activities.
In-water Construction Effects on Potential Prey (Fish)--
Construction activities would produce continuous (i.e., vibratory pile
driving and down-the-hole drilling) and intermittent (i.e. impact
driving) sounds. Fish react to sounds that are especially strong and/or
intermittent low-frequency sounds. Short duration, sharp sounds can
cause overt or subtle changes in fish behavior and local distribution.
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).
Sound pulses at received levels of 160 dB may cause subtle changes in
fish behavior. SPLs of 180 dB may cause noticeable changes in behavior
(Pearson et al. 1992; Skalski et al. 1992). SPLs of sufficient strength
have been known to cause injury to fish and fish mortality.
The most likely impact to fish from pile driving and drilling
activities at the project area would be temporary behavioral avoidance
of the area. The duration of fish avoidance of this area after pile
driving stops is unknown, but a rapid return to normal recruitment,
distribution and behavior is anticipated. In general, impacts to marine
mammal prey species are expected to be minor and temporary due to the
short timeframe for the project.
Construction activities, in the form of increased turbidity, have
the potential to adversely affect forage fish and juvenile salmonid
outmigratory routes
[[Page 7032]]
in the project area. Both herring and salmon form a significant prey
base for Steller sea lions, herring is a primary prey species of
humpback whales, and both herring and salmon are components of the diet
of many other marine mammal species that occur in the project area.
Increased turbidity is expected to occur in the immediate vicinity (on
the order of 10 feet 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 and salmon are expected
to be minor or negligible. In addition, best management practices would
be in effect, which would limit the extent of turbidity to the
immediate project area.
In summary, given the short daily duration of sound associated with
individual pile driving and drilling events and the relatively small
areas being affected, pile driving and drilling activities associated
with the proposed action are not likely to have a permanent, adverse
effect on any fish habitat, or populations of fish species. 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
determination.
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 be by Level B harassment only, in the form
of disruption of behavioral patterns for individual marine mammals
resulting from exposure to impact and vibratory hammers and down-the-
hole drilling. Based on the nature of the activity and the anticipated
effectiveness of the mitigation measures (i.e., shutdown--discussed in
detail below in Proposed Mitigation section), Level A harassment is
neither anticipated nor proposed to be authorized.
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
Using the best available science, NMFS has developed acoustic
thresholds that identify the received level of underwater sound above
which exposed marine mammals would be reasonably expected to be
behaviorally harassed (equated to Level B harassment) or to incur PTS
of some degree (equated to Level A harassment).
Level B Harassment 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 [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. CBS's proposed activity includes the
use of continuous (vibratory pile driving/removal and drilling) and
impulsive (impact pile driving) sources, and therefore the 120 and 160
dB re 1 [mu]Pa (rms) thresholds 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). CBS's proposed activity includes the use
of impulsive (impact pile driving) and non-impulsive (vibratory pile
driving/removal and drilling) sources.
These thresholds are provided in the table below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS 2018 Technical Guidance, which may be accessed at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 3--Thresholds identifying the onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset thresholds * (received level)
Hearing group -----------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans............ Lp,0-pk,flat: 219 dB; LE,p, LE,p, LF,24h: 199 dB.
LF,24h: 183 dB.
[[Page 7033]]
Mid-Frequency (MF) Cetaceans............ Lp,0-pk,flat: 230 dB; LE,p, LE,p, MF,24h: 198 dB.
MF,24h: 185 dB.
High-Frequency (HF) Cetaceans........... Lp,0-pk,flat: 202 dB; LE,p, LE,p, HF,24h: 173 dB.
HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)...... Lp,0-pk.flat: 218 dB; LE,p, LE,p, PW,24h: 201 dB.
PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)..... Lp,0-pk,flat: 232 dB; LE,p, LE,p, OW,24h: 219 dB.
OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric 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 are recommended for consideration.
Note: Peak sound pressure level (Lp,0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
exposure level (LE,p) has a reference value of 1[micro]Pa\2\s. In this table, thresholds are abbreviated to be
more reflective of International Organization for Standardization standards (ISO 2017). The subscript ``flat''
is being included to indicate peak sound pressure are flat weighted or unweighted within the generalized
hearing range of marine mammals (i.e., 7 Hz to 160 kHz). 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 weighted
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 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 and removal and down-the-hole drilling). The maximum
(underwater) ensonified area is truncated by land masses and largely
confined to marine waters within Eastern Channel of Sitka Sound,
extending approximately 7.7 kilometers through Crescent Bay, Middle
Channel, and into Eastern Channel and encompassing approximately 7.26
square kilometers (see Figure 5 in the application).
The distances to the Level A and Level B harassment thresholds were
calculated based on source levels from the Naval Base Kitsap at Bangor
EHW-1 Pile Replacement Project, in Bangor, Washington (NAVFAC 2012) and
the Kodiak Ferry Terminal Project in Kodiak, Alaska (Denes et. al.
2016) for a given activity and pile type (e.g., vibratory removal/
installation, drilling, and impact pile driving of 24-inch diameter
steel piles). The vibratory source level is proxy from 24-inch steel
piles driven at the Naval Base Kitsap in Bangor, Washington (NAVFAC
2012) and from acoustic modeling of nearshore marine pile driving at
Navy installations in Puget Sound (United States Navy 2015). The
socketing source level is proxy from mean measured sources levels from
drilling of 24-inch diameter piles to construct the Kodiak Ferry
Terminal (Denes et al. 2016). Sound pressure level root-mean-square
(SPL rms) values were used to calculate distance to Level A and B
harassment isopleths for impact pile driving. The source levels of
168.2 SEL (for Level A harassment) and 181.3 SPL (for Level B
harassment) are the mean measured levels from the Kodiak Ferry Terminal
project (Denes et al. 2016).
Transmission loss (TL) is the decrease in acoustic intensity as an
acoustic pressure wave propagates out from a source. TL parameters vary
with frequency, temperature, sea conditions, current, source and
receiver depth, water depth, water chemistry, and bottom composition
and topography. The general formula for underwater TL is:
TL = B * Log10 (R 1/R 2), where
TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R 1= the distance of the modeled SPL from the driven
pile, and
R 2= the distance from the driven pile of the initial
measurement
A practical spreading value of fifteen is often used under
conditions, such as at the lightering dock location, where water
increases with depth as the receiver moves away from the shoreline,
resulting in an expected propagation environment that would lie between
spherical and cylindrical spreading loss conditions. Practical
spreading loss is assumed here.
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 pile
driving and drilling, NMFS User Spreadsheet predicts the closest
distance at which, if a marine mammal remained at that distance the
whole duration of the activity, it would not incur PTS. Inputs used in
the User Spreadsheet, and the resulting isopleths are reported in
Tables 4 and 5. Isopleths for Level B harassment associated with impact
pile driving (160 dB) and vibratory pile driving/removal and drilling
(120 dB) were also calculated and are can be found in Table 5.
[[Page 7034]]
Table 4--User Spreadsheet Input Parameters Used for Calculating Harassment Isopleths
----------------------------------------------------------------------------------------------------------------
Vibratory driving Drilling/socketing Impact driving
------------------------------------------------------------------------------
(A.1) Vibratory driving-- (E.1): Impact pile
Spreadsheet tab used stationary source: non- (A) Stationary source: driving (stationary
impulsive, continuous non-impulsive, source: impulsive,
continuous intermittent
----------------------------------------------------------------------------------------------------------------
Source Level (dB)................ 161 RMS SPL 167.7 RMS SPL........... 168.2 SEL.
Weighting Factor Adjustment (kHz) 2.5...................... 2....................... 2.
(a) Number of piles in 24-hr..... 12....................... n/a..................... 6.
(b) Number of strikes/pile....... n/a...................... n/a..................... 5.
(c) Duration of sound (hours) n/a...................... 6....................... n/a.
within 24-h period.
(d) Duration of drive single pile 5........................ n/a..................... n/a.
(minutes).
Propagation (xLogR).............. 15....................... 15...................... 15.
Distance of source level 10....................... 10...................... 10.
measurement (meters).
----------------------------------------------------------------------------------------------------------------
* n/a: not applicable
Table 5--Calculated Distances to Level A Harassment and Level B Harassment Isopleths During Pile Installation and Removal and Drilling
--------------------------------------------------------------------------------------------------------------------------------------------------------
Distance (m) to level A and level B thresholds
-----------------------------------------------------------------------------------------------
Source level at 10 Level A
Activity meters (dB) --------------------------------------------------------------------------------
Low-frequency Mid- frequency High-frequency Level B
cetaceans cetaceans cetaceans Phocid Otariid
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving/Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch steel removal and 161 SPL............. 6.8 0.6 10.1 4.2 0.3 5,412
installation (12 piles) (~1 hour
on 1 day).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Drilling/Socketing Pile Installation
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch steel installation (6 167.7 SPL........... 6.3 0.4 5.6 3.4 0.2 *15,136
piles) (6 hours per day on 2
days).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch steel installation (6 168.2 SEL/181.3 SPL. 9.9 0.4 11.8 5.3 0.4 263
piles) (~3 minutes per day on 1
day).
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Ensonified are area would be truncated by land masses with a maximum extent of 7.7 km.
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 and how this information is brought together to produce a
quantitative take estimate.
Density information is not available for marine mammals in the
project area. Potential exposures for marine mammals were estimated
from several sources. Between the months of September through May from
1994 to 2002, weekly surveys were conducted at Sitka's Whale Park,
located at the easternmost end of Eastern Channel as shown in Figure 5
in the application. More recent data (from 2002 to present) were
collected from small vessels or Allen Marine 100-foot catamarans during
school field trips in and around Eastern Channel. Additionally, marine
mammal observational data was collected in the Sitka Channel as part of
the Gary Paxton Industrial Park (GPIP) Multipurpose Dock Project
(Turnagain 2017). Monitors were present during twenty-two days of in
water work as part of this project. This included ten days between
October 9th and 20th, 2017 for wooden pile removal, where only one
monitor was present each day and twelve days between October 22nd and
November 9th, where two observers were monitoring during new pile
installation. Additionally, data was collected in January and October/
November of 2017 in the Sitka Channel when Petro Marine Services
removed and replaced a fuel float in the Sitka Channel and recorded
marine mammal observations (Windward 2017). Finally, marine mammal
observation reports covering the months of June through September, 2018
were also reviewed (Turnagain 2018).
Level B Harassment Calculations
The estimation of takes by Level B harassment uses the following
calculation:
Level B harassment estimate = N (number of animals in the
ensonified area) * Number of days of noise generating activities.
Humpback Whale
Humpback whales are the most commonly observed baleen whale in
Southeast Alaska, particularly during spring and summer months.
Humpback whales frequent the action area and could be encountered
during any given
[[Page 7035]]
day of pile driving/removal activities. In the project vicinity,
humpback whales typically occur in groups of 1 to 2 animals, with an
estimated maximum group size of 4 animals. Most humpback whales
observed in the area were solitary. When more than one whale was
observed, available survey data reports a typical group size of 2-4
whales (Straley et al. 2018). During work on GPIP Dock, groups of 5 and
10 individuals were seen a few times, but most of the time, single
whales were observed (Turnagain 2017). CBS conservatively estimates
that a group of 5 humpback whales may occur within the Level B
harassment zone every day of the 3-day construction window during
active pile driving (5 animals in a group x 1 group each day x 3 days =
15 animals). Therefore, CBS requests and NMFS proposes to authorize 15
Level B harassment takes of humpback whales. Based on Wade et al.
(2016), the probability is that 93.9 percent of the humpback whales
taken would be from the Hawaii DPS (not listed under ESA) and 6.1
percent of the humpback whales taken would be from the ESA-listed
threatened Mexico DPS.
Killer Whale
Killer whales pass through the action area and could be encountered
during any given day of pile removal and installation. In the project
vicinity, typical killer whale pod sizes vary from between 4-8
individuals, with an estimated maximum group size of 8 animals (Straley
et al. 2018). A pod of three killer whales were observed during
monitoring for the Petro Marine Dock, and a pod of seven whales were
observed on one day near Biorka Island (Windward 2017; Turnagain 2018).
CBS estimates that a group of 8 killer whales may occur within the
Level B harassment zone every day of during active pile driving (8
animals in a group x 1 group each day x 3 days = 24 animals).
Therefore, CBS requests and NMFS proposes to authorize 24 killer whales
takes by Level B harassment.
Harbor Porpoise
Harbor porpoises are seen infrequently in the action area, but they
could be encountered during any given day of pile replacement
activities. The mean group size of harbor porpoise in Southeast Alaska
was estimated to be between 2 to 3 individuals (Dahlheim et al., 2009).
In the project vicinity, harbor porpoises typically occur in groups of
1-5 animals, with an estimated maximum group size of 8 animals (Straley
et al. 2018). No harbor porpoises were seen during the Petro Marine
Dock construction monitoring in January 2017 or during monitoring for
the GPIP dock between October and November of 2017 (Windward 2017 and
Turnagain 2017). CBS conservatively estimates that a group of 5 harbor
porpoise may occur within the Level B harassment zone once each day
during the 3-day construction window during active pile driving (5
animals in a group x 1 group each day x 3 days = 15 animals).
Therefore, CBS conservatively requests and NMFS proposes to authorize
15 Level B harassment takes of harbor porpoises.
Harbor Seal
Harbor seals are common in the action area and are expected to be
encountered during pile replacement activities. In the action area
harbor seals typically occur in groups of 1-3 animals. Observations
near Sitka Channel recorded only individual seals, and observations for
GPIP dock observed mostly individuals, however, a few groups with up to
3 seals were observed. Near Biorka Island, recent sightings ranged from
1 individual to a group of 9 (June and September 2018) groups up to 3
(July 2018), and groups up to 8 (August 2018). Harbor seals could occur
in the project area every day. CBS conservatively estimates that 2
groups of 3 harbor seals may occur within the Level B harassment zone
every day that pile driving occurs (3 animals in a group x 2 groups per
day x 3 days = 18 animals). Therefore, CBS requests and NMFS proposes
to authorize 18 harbor seal takes by Level B harassment.
Steller Sea Lion
Steller sea lions are common in the action area and are expected to
be encountered during pile removal and driving. In the project vicinity
Steller sea lions typically occur in groups of 1-8 animals near the
project area (Turnagain 2017 and Windward 2017), with an estimated
maximum group size of 100 animals (Straley et al. 2018). Steller sea
lions can occur in the action area every day during construction. CBS
conservatively estimates that a group of 8 Steller sea lions may occur
within the Level B harassment zone every day that pile driving occurs
(8 animals in a group x 1 group x 3 days = 24 animals). Therefore, CBS
requests and NMFS proposes to authorize 24 takes of sea lion by Level B
harassment.
CBS intends to avoid Level A harassment take by shutting down
removal or installation activities at the approach of any marine mammal
into their representative Level A harassment (PTS onset) zone.
Table 6--Estimated Take by Level B Harassment, by Species and Stock and Percent of Stock
----------------------------------------------------------------------------------------------------------------
Percent of
Species Stock Level B stock
----------------------------------------------------------------------------------------------------------------
Humpback Whale................................ Central North Pacific (10,103).. 15 0.01
Killer Whale.................................. Alaska Resident (2,347)......... \1\ 24 1.02
Northern Resident (261) 9.20
West Coast Transient (243) 9.88
Gulf of Alaska, Aleutian 4.1
Islands, Bering Sea Transient
(587)
Harbor Porpoise............................... Southeast Alaska (975).......... 15 1.54
Harbor Seal................................... Sitka/Chatham Strait (14,855)... 18 <0.01
Steller Sea Lion.............................. Western DPS (54,267)............ \1\ 24 0.04
Eastern DPS (41,638) 0.06
----------------------------------------------------------------------------------------------------------------
\1\ Assumes all takes come from each individual stock.
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 such
activity, and other means of effecting the least practicable impact on
such species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of such species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for
[[Page 7036]]
incidental take authorizations to include information about the
availability and feasibility (economic and technological) of equipment,
methods, and manner of conducting such 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.
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.
In addition to the measures described later in this section, CBS
will employ the following standard mitigation measures:
Conduct briefings between construction supervisors and
crews and the marine mammal monitoring team prior to the start of all
pile driving activity, and when new personnel join the work, to explain
responsibilities, communication procedures, marine mammal monitoring
protocol, and operational procedures;
For in-water heavy machinery work other than pile driving
(e.g., standard barges, etc.), if a marine mammal comes within 10 m,
operations shall cease and vessels shall reduce speed to the minimum
level required to maintain steerage and safe working conditions. This
type of work could include the following activities: (1) Movement of
the barge to the pile location; or (2) positioning of the pile on the
substrate via a crane (i.e., stabbing the pile);
Work may only occur during daylight hours, when visual
monitoring of marine mammals can be conducted;
For those marine mammals for which take by Level B
harassment has not been requested, in-water pile installation/removal
and drilling will shut down immediately if such species are observed
within or on a path towards the monitoring zone (i.e., Level B
harassment zone); and
If take reaches the authorized limit for an authorized
species, pile driving activities will be stopped as these species
approach the Level B harassment zone to avoid additional take.
The following measures would apply to CBS's mitigation
requirements:
Establishment of Shutdown Zone--For all pile driving/removal and
drilling activities, CBS would establish a shutdown zone to avoid take
by Level A harassment. The purpose of a shutdown zone is generally to
define an area within which shutdown of activity would occur upon
sighting of a marine mammal (or in anticipation of an animal entering
the defined area). The shutdown zone would be 10 m in all cases except
for high-frequency cetaceans (harbor porpoises) during impact pile
driving and vibratory pile driving/removal. In those situations the
shutdown zone for high-frequency cetaceans would be 15 m (Table 7).
These defined shutdown zones would be used to prevent incidental Level
A harassment exposures and reduce the potential for such take for other
species. The placement of Protected Species Observers (PSOs) during all
pile driving and drilling activities (described in detail in the
Monitoring and Reporting Section) will ensure shutdown zones are
visible.
Table 7--Proposed Shut Down Zone for Each Project Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-frequency Mid-frequency High-frequency
Noise source cetaceans cetaceans (killer cetaceans (harbor Phocid (harbor Otariid (sea
(humpback whale) whale) porpoise) seal) lion)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving/Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch steel removal and installation (12 piles) (~1 10 10 15 10 10
hour on 1 day)..........................................
--------------------------------------------------------------------------------------------------------------------------------------------------------
Drilling/Socketing Pile Installation
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch steel installation (6 piles) (6 hours per day on 10 10 10 10 10
2 days).................................................
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch steel installation (6 piles) (~3 minutes on 1 10 10 15 10 10
day)....................................................
--------------------------------------------------------------------------------------------------------------------------------------------------------
Establishment of Monitoring Zones for Level B Harassment--CBS would
establish monitoring zones to correlate with Level B harassment
disturbance zones or zones of influence which are areas where SPLs are
equal to or exceed the 160 dB rms threshold for impact driving and the
120 dB rms threshold during vibratory driving and drilling. Monitoring
zones provide utility for observing by establishing monitoring
protocols for areas adjacent to the shutdown zones. Monitoring zones
enable observers to be aware of and communicate the presence of marine
mammals in the project area outside the shutdown zone and thus prepare
for a potential cease of activity should the animal enter the shutdown
zone. The proposed monitoring zones are described in Table 8. The
monitoring zone for drilling activities extends 7,700 m from the noise
source, corresponding to the maximum distance before landfall. It is
likely that PSOs would not be able to effectively observe the entire
monitoring zone. Therefore, Level B harassment exposures will be
recorded and extrapolated based upon the number of observed takes and
the
[[Page 7037]]
percentage of the Level B harassment zone that was not visible.
Table 8--Level B Harassment Monitoring Zones
------------------------------------------------------------------------
Monitoring zones
for take by Level
Pile driving noise source B harassment
(meters)
------------------------------------------------------------------------
Vibratory Pile Driving
------------------------------------------------------------------------
16-inch steel removal and installation (12 piles) (~1 5,500
hour on 1 day)......................................
------------------------------------------------------------------------
Socketing Pile Installation
------------------------------------------------------------------------
16-inch steel installation (6 piles) (6 hours per day 7,700
on 2 days)..........................................
------------------------------------------------------------------------
Impact Pile Driving
------------------------------------------------------------------------
16-inch steel installation (6 piles) (~3 minutes per 265
day on 1 day).......................................
------------------------------------------------------------------------
Use of Pile Caps/Cushions--Pile driving softening material (i.e.
pile caps/cushions) will be used to minimize noise during vibratory and
impact pile driving. Much of the noise generated during pile
installation comes from contact between the pile being driven and the
steel template used to hold the pile in place. The contractor will use
high-density polyethylene (HDPE) or ultra-high-molecular-weight
polyethylene (UHMW) softening material on all templates to eliminate
steel on steel noise generation.
Direct Pull--To minimize construction noise levels as much as
possible, the contractor will first attempt to direct pull old piles;
if those efforts prove to be ineffective, they will proceed with a
vibratory hammer.
Reduced Energy-- To reduce noise production, the vibratory hammer
will be operated at a reduced energy setting (30 to 50 percent of its
rated energy).
Soft Start--The use of soft-start procedures are believed to
provide additional protection to marine mammals by providing warning
and/or giving marine mammals a chance to leave the area prior to the
hammer operating at full capacity. For impact pile driving, contractors
would be required to provide an initial set of strikes from the hammer
at reduced energy, with each strike followed by a 30-second waiting
period. This procedure would be conducted a total of three times before
impact pile driving begins. Soft start would be implemented at the
start of each day's impact pile driving (if more than one day) and at
any time following cessation of impact pile driving for a period of
thirty minutes or longer. Soft start is not required during vibratory
pile driving and removal activities.
Pre-Activity Monitoring--Prior to the start of daily in-water
construction activity, or whenever a break in pile driving/removal or
drilling of 30 minutes or longer occurs, PSOs will observe the shutdown
and monitoring zones for a period of 30 minutes. The shutdown zone will
be cleared when a marine mammal has not been observed within the zone
for the 30-minute period. If a marine mammal is observed within the
shutdown zone, a soft-start cannot proceed until the animal has left
the zone or has not been observed for 15 minutes. If the Level B
harassment zone has been observed for 30 minutes and non-permitted
species are not present within the zone, soft start procedures can
commence and work can continue even if visibility becomes impaired
within the Level B harassment monitoring zone. When a marine mammal
permitted for Level B take is present in the Level B harassment zone,
activities may begin and Level B take will be recorded. As stated
above, if the entire Level B harassment zone is not visible at the
start of construction, piling driving or drilling activities can begin.
If work ceases for more than 30 minutes, the pre-activity monitoring of
both the Level B harassment and shutdown zone will commence.
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.
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:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or
[[Page 7038]]
cumulative impacts from multiple stressors;
How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
Mitigation and monitoring effectiveness.
Monitoring shall be conducted by NMFS-approved PSOs. Trained
observers shall be placed from the best vantage point(s) practicable to
monitor for marine mammals and implement shutdown or delay procedures
when applicable through communication with the equipment operator.
Observer training must be provided prior to project start, and shall
include instruction on species identification (sufficient to
distinguish the species in the project area), description and
categorization of observed behaviors and interpretation of behaviors
that may be construed as being reactions to the specified activity,
proper completion of data forms, and other basic components of
biological monitoring, including tracking of observed animals or groups
of animals such that repeat sound exposures may be attributed to
individuals (to the extent possible).
Monitoring would be conducted 30 minutes before, during, and 30
minutes after pile driving/removal and drilling activities. In
addition, observers shall record all incidents of marine mammal
occurrence, regardless of distance from activity, and shall document
any behavioral reactions in concert with distance from piles being
driven or removed. Pile driving/removal and drilling activities include
the time to install or remove a single pile or series of piles, as long
as the time elapsed between uses of the pile driving equipment is no
more than 30 minutes.
PSOs would scan the waters using binoculars, and/or spotting
scopes, and would use a handheld GPS or range-finder device to verify
the distance to each sighting from the project site. All PSOs would be
trained in marine mammal identification and behaviors and are required
to have no other project-related tasks while conducting monitoring. In
addition, monitoring will be conducted by qualified observers, who will
be placed at the best vantage point(s) practicable to monitor for
marine mammals and implement shutdown/delay procedures when applicable
by calling for the shutdown to the hammer operator. CBS would adhere to
the following observer qualifications:
(i) Independent observers (i.e., not construction personnel) are
required.
(ii) At least one observer must have prior experience working as an
observer.
(iii) Other observers may substitute education (degree in
biological science or related field) or training for experience.
(iv) NMFS will require submission and approval of observer CVs.
CBS must ensure that observers have the following additional
qualifications:
1. Ability to conduct field observations and collect data according
to assigned protocols;
2. Experience or training in the field identification of marine
mammals, including the identification of behaviors;
3. Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
4. 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
5. 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.
Two land-based PSOs would be used to monitor the area during all
pile driving and removal activities. One PSO would monitor from the
O'Connell Bridge which features a high vantage point with unobstructed
views of, and close proximity to, the project site. A second monitor
would be stationed east of the construction site, likely off Islander
Drive. PSOs will work in shifts lasting no longer than 4 hours with at
least a 1-hour break between shifts, and will not perform duties as a
PSO for more than 12 hours in a 24-hr period to reduce PSO fatigue.
A draft marine mammal monitoring report would be submitted to NMFS
within 90 days after the completion of pile driving and removal and
drilling activities. It will include an overall description of work
completed, a narrative regarding marine mammal sightings, and
associated PSO data sheets. Specifically, the report must include:
Dates and times (begin and end) of all marine mammal
monitoring;
Construction activities occurring during each daily
observation period, including how many and what type of piles were
driven or removed and by what method (i.e., impact or vibratory);
Weather parameters and water conditions during each
monitoring period (e.g., wind speed, percent cover, visibility, sea
state);
The number of marine mammals observed, by species,
relative to the pile location and if pile driving or removal was
occurring at time of sighting;
Age and sex class, if possible, of all marine mammals
observed;
PSO locations during marine mammal monitoring;
Distances and bearings of each marine mammal observed to
the pile being driven or removed for each sighting (if pile driving or
removal was occurring at time of sighting);
Description of any marine mammal behavior patterns during
observation, including direction of travel;
Number of individuals of each species (differentiated by
month as appropriate) detected within the monitoring zone, and
estimates of number of marine mammals taken, by species (a correction
factor may be applied to total take numbers, as appropriate);
Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensued, and resulting behavior of the animal, if
any; and
Description of attempts to distinguish between the number
of individual animals taken and the number of incidences of take, such
as ability to track groups or individuals.
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.
In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner prohibited by the IHA
(if issued), such as an injury, serious injury or mortality, CBS would
immediately cease the specified activities and report the incident to
the Chief of the Permits and Conservation Division, Office of Protected
Resources, NMFS, and the Alaska Regional Stranding Coordinator. The
report would include the following information:
Description of the incident;
Environmental conditions (e.g., Beaufort sea state,
visibility);
Description of all marine mammal observations in the 24
hours preceding the incident;
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Species identification or description of the animal(s)
involved;
Fate of the animal(s); and
Photographs or video footage of the animal(s) (if
equipment is available).
Activities would not resume until NMFS is able to review the
circumstances of the prohibited take. NMFS would work with CBS to
determine what is necessary to minimize the likelihood of further
prohibited take and ensure MMPA compliance. CBS would not be able to
resume their activities until notified by NMFS via letter, email, or
telephone.
In the event that CBS discovers an injured or dead marine mammal,
and the lead PSO determines that the cause of the injury or death is
unknown and the death is relatively recent (e.g., in less than a
moderate state of decomposition as described in the next paragraph),
CBS would immediately report the incident to the Chief of the Permits
and Conservation Division, Office of Protected Resources, NMFS, and the
Alaska Regional Stranding Coordinator. The report would include the
same information identified in the paragraph above. Activities would be
able to continue while NMFS reviews the circumstances of the incident.
NMFS would work with CBS to determine whether modifications in the
activities are appropriate.
In the event that CBS discovers an injured or dead marine mammal
and the lead PSO determines that the injury or death is not associated
with or related to the activities authorized in the IHA (e.g.,
previously wounded animal, carcass with moderate to advanced
decomposition, or scavenger damage), CBS would report the incident to
the Chief of the Permits and Conservation Division, Office of Protected
Resources, NMFS, and the Alaska Regional Stranding Coordinator, within
24 hours of the discovery. CBS would provide photographs, video footage
(if available), or other documentation of the stranded animal sighting
to NMFS and the Marine Mammal Stranding Network.
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).
Pile driving, pile removal and drilling activities 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 from underwater sounds generated from vibratory
pile removal, vibratory pile driving, impact pile driving, and drilling
over 3 days. Potential takes could occur if individuals of these
species are present in the ensonified zone when these activities are
underway. One day of work would be dedicated to removing 6 old and
installing 6 new piles which would emit low levels of noise into the
aquatic environment if removed via direct pull or vibratory hammer and
installed via vibratory hammer as proposed. Vibratory removal and
installation would take approximately one hour. Drilling would occur
for only 6 hours per day over 2 days. Impact driving would be used to
proof socketed piles and take place for a total of 3 minutes on a
single day.
Effects on individuals that are taken by Level B harassment, on the
basis of reports in the literature as well as monitoring from other
similar activities, will likely be limited to reactions such as
increased swimming speeds, increased surfacing time, or decreased
foraging (if such activity were occurring) (e.g., Thorson and Reyff
2006; HDR, Inc. 2012; Lerma 2014; ABR 2016). Most likely, individuals
will simply move away from the sound source and be temporarily
displaced from the areas of pile driving and drilling, although even
this reaction has been observed primarily only in association with
impact pile driving. The pile driving activities analyzed here are
similar to, or less impactful than, numerous other construction
activities conducted in southeast Alaska, which have taken place with
no known long-term adverse consequences from behavioral harassment.
Level B harassment will be reduced to the level of least practicable
adverse impact through use of mitigation measures described herein and,
if sound produced by project activities is sufficiently disturbing,
animals are likely to simply avoid the area while the activity is
occurring.
The project also is not expected to have significant adverse
effects on affected marine mammals' habitat. Project activities would
not modify existing marine mammal habitat for a significant amount of
time. The activities may cause some fish to leave the area of
disturbance, thus temporarily impacting marine mammals' foraging
opportunities in a limited portion of the foraging range. However,
because of the short duration of the activities and the relatively
small area of the habitat that may be affected, and the decreased
potential of prey species to be in the project area during the
construction work window, the impacts to marine mammal habitat are not
expected to cause significant or long-term negative consequences.
In summary and as described above, the following factors primarily
support our 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:
No mortality is anticipated or authorized;
No Level A take is authorized;
Level B harassment may consist of, at worst, temporary
modifications in behavior (e.g. temporary avoidance of habitat or
changes in behavior);
The specified activity is temporary and of short duration;
The ensonified area is very small relative to the overall
habitat ranges of all species and does not include habitat areas of
special significance (BIAs or ESA-designated critical habitat); and
The presumed efficacy of the proposed mitigation measures
in reducing the effects of the specified activity to the level of least
practicable adverse impact.
In addition, although affected humpback whales and Steller sea
lions may be from a DPS that is listed under the ESA, it is unlikely
that minor noise effects in a small, localized area of habitat would
have any effect on the stocks' ability to recover. In
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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.
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. Additionally, other qualitative
factors may be considered in the analysis, such as the temporal or
spatial scale of the activities.
Table 6 presents the number of animals that could be exposed to
received noise levels that may result in Level B take for the proposed
work at O'Connell Bridge. Our analysis shows that less than 10 percent
of the best available population estimate of each affected stock could
be taken. Furthermore, these percentages conservatively assume that all
takes of killer whale and Steller sea lion would be accrued to a single
stock, when multiple stocks are known to occur in the project area.
Therefore, the numbers of animals authorized to be taken for all
species would be considered small relative to the relevant stocks or
populations even if each estimated taking occurred to a new
individual--an extremely unlikely scenario. For pinnipeds, especially
harbor seals and Steller sea lions, occurring in the vicinity of the
project site, there could be some overlap in individuals present day-
to-day, and these takes are likely to occur only within some small
portion of the overall regional stock.
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.
The peak hunting season in southeast Alaska occurs during the month
of November and again over the March to April time frame (Wolfe et al.,
2013). The proposed project is in an area where subsistence hunting for
harbor seals or sea lions could occur (Wolfe et al., 2013), but the
area near the proposed project location is not preferred for hunting.
During September 2018, CBS contacted the Alaska Harbor Seal
Commission, the Alaska Sea Otter and Steller Sea Lion Commission, and
the Sitka Tribe of Alaska. These organizations expressed no concerns
about the impact of the proposed action on subsistence marine mammals
or their harvest by hunters near the project area. The Sitka Tribe did
request that no pile driving occur between March 15 and May 31 to
protect herring, as has been the case for past permitting in Sitka
Sound. In response to this request, CBS will not commence in-water
construction operations prior to June 1, 2019 or between March 15, 2020
and May 31, 2020.
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 CBS's
proposed activities.
Endangered Species Act (ESA)
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, in this case with Alaska Regional Office,
whenever we propose to authorize take for endangered or threatened
species.
NMFS is proposing to authorize take of the Steller sea lion western
DPS and humpback whale Mexico DPS, which are listed under the ESA. The
NMFS Office of Protected Resources has requested initiation of section
7 consultation with the Alaska Regional Office for the issuance of this
IHA. NMFS will conclude the ESA consultation prior to reaching a
determination regarding the proposed issuance of the authorization.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to CBS for the O'Connell Bridge Lightering Float Pile
Replacement project in Sitka, Alaska from June 1, 2019 through May 31,
2020, provided the previously mentioned mitigation, monitoring, and
reporting requirements are incorporated. A draft of the IHA itself is
available for review in conjunction with this notice at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.
Request for Public Comments
We request comment on our analyses, the proposed authorization, and
any other aspect of this Notice of Proposed IHA for the proposed
action. We also request comment on the potential for 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 our final decision on the request for MMPA authorization.
On a case-by-case basis, NMFS may issue a second one-year IHA
without additional notice when (1) another year of identical or nearly
identical activities as described in the Specified Activities section
is planned or (2) the activities would not be completed by the time the
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IHA expires and a second IHA would allow for completion of the
activities beyond that described in the Dates and Duration section,
provided all of the following conditions are met:
A request for renewal is received no later than 60 days
prior to expiration of the current IHA;
The request for renewal must include the following:
(1) An explanation that the activities to be conducted beyond the
initial dates either are identical to the previously analyzed
activities or include changes so minor (e.g., reduction in pile size)
that the changes do not affect the previous analyses, take estimates,
or mitigation and monitoring requirements; and
(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; and
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 remain the same and appropriate,
and the original findings remain valid.
Dated: February 26, 2019.
Catherine Marzin,
Acting Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2019-03684 Filed 2-28-19; 8:45 am]
BILLING CODE 3510-22-P