Taking of Marine Mammals Incidental to Specific Activities; Taking of Marine Mammals Incidental to Pile Driving and Removal Activities During Construction of a Cruise Ship Berth, Hoonah, Alaska
| Published date | 01 May 2019 |
| Citation | 84 FR 18495 |
| Record Number | 2019-08848 |
| Section | Notices |
| Court | National Oceanic And Atmospheric Administration |
Federal Register, Volume 84 Issue 84 (Wednesday, May 1, 2019)
[Federal Register Volume 84, Number 84 (Wednesday, May 1, 2019)]
[Notices]
[Pages 18495-18521]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-08848]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XG874
Taking of Marine Mammals Incidental to Specific Activities;
Taking of Marine Mammals Incidental to Pile Driving and Removal
Activities During Construction of a Cruise Ship Berth, Hoonah, 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 Duck Point Development II, LLC.
(DPD) for authorization to take marine mammals incidental pile driving
and removal activities during construction of a second cruise ship
berth and new lightering float at Cannery Point (Icy Strait) on
Chichagof Island near Hoonah, 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 May 31,
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/permit/incidental-take-authorizations-under-marine-mammal-protection-act without change. All personal identifying
information (e.g., name, address) voluntarily submitted by the
commenter may be publicly accessible. Do not submit confidential
business information or otherwise sensitive or protected information.
FOR FURTHER INFORMATION CONTACT: Stephanie Egger, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the application
and supporting documents, as well as a list of the references cited in
this document, may be obtained online at: https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. 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.
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 December 28, 2018 NMFS received a request DPD for an IHA to take
marine mammals incidental to pile driving and removal activities during
construction of a second cruise ship berth and new lightering float at
Cannery Point (Icy Strait) on Chichagof Island near Hoonah, Alaska. The
application was deemed adequate and complete on April 3, 2019. The
applicant's request is for take nine species of marine mammals by Level
B harassment and three species by Level A harassment. Neither DPD nor
NMFS
[[Page 18496]]
expects serious injury or mortality to result from this activity and,
therefore, an IHA is appropriate. NMFS previously issued an IHA to the
Huna Totem Corporation for the first cruise ship berth in Hoonah, AK in
2015 (80 FR 31352; June 2, 2015).
Description of Proposed Activity
Overview
The purpose of this project is to construct a second offshore
mooring facility and small-craft lightering float to accommodate the
exponential growth in cruise ship traffic Hoonah is currently
experiencing. The project is needed because the existing berth
configuration does not have the capacity to support multiple cruise
ships at the same time. Furthermore, the increase in small vessel
traffic generated by the increase in visitor numbers necessitates the
addition of a small-boat lightering float for short excursions around
Icy Strait Point. Once the project is constructed, Hoonah will be
better able to accommodate the increased number of cruise ships and
passengers visiting the community. Therefore, Duck Point Development
proposes to construct a second cruise ship berth and new lightering
float at Cannery Point (Icy Strait) on Chichagof Island near Hoonah,
Alaska, in order to accommodate the increase in cruise ship and visitor
traffic since completion of the first permanent cruise ship berth
completion in 2016 (80 FR 31352; June 2, 2015). The in-water sound from
the pile driving and removal activities, may incidentally take nine
species of marine mammals by Level B harassment and three species by
Level A harassment.
Revenue generated from the tourism industry is a vital part of
Hoonah's economy. Since the addition the permanent cruise ship berth in
2016, Hoonah has become a top cruise ship port in Alaska, with growth
from 34 ship visits in 2004 to a projected 122 visits in 2019 (Alaska
Business Monthly 2018). Prior to placement of the permanent berth,
cruise ship passengers were transferred to shore via smaller,
``lightering'' vessels. Construction of the berth allowed for direct
walking access from ships to the shore, and more passengers
disembarking in Hoonah. In 2016, an estimated 150,000 passengers
visited Hoonah on 78 large-scale cruise ships, with many visiting
Hoonah's shops and restaurants (LeMay Engineering & Consulting 2018).
The existing berth can only accommodate one large vessel at a time.
Oftentimes a second visiting ship is forced to idle in Port Frederick
Inlet near the cannery to wait for mooring space, or return to the
traditional methods of lightering passengers to shore via small
vessels. In addition to safety concerns stemming from decreased large-
ship maneuverability at this location, idling ships and lightering
vessels increase fuel consumption, noise, and hydrocarbon pollution
within the inlet. A second shore berth is needed to allow multiple
cruise ships' pedestrian visitors access directly to shore.
The increase in visitors to Hoonah has concurrently increased
demand for offshore day excursions around Port Frederick and Icy Strait
for wildlife viewing. An additional lightering float on the west side
of the point, nearer to the Icy Strait Cannery, is needed to add
mooring capacity for small vessels providing these short-day
excursions.
Dates and Duration
The applicant is requesting an IHA to conduct pile driving and
removal over 75 working days (not necessarily consecutive) beginning
June 1, 2019 and extending into November 2019 as needed. Approximately
39 days of vibratory and 8 days of impact hammering will occur. An
additional 14 days of socketing and 14 days of anchoring will occur to
stabilize the piles. These are discussed in further detail below.
Specific Geographic Region
The proposed project is located off Cannery Point, approximately
2.4 kilometers (km) north of Hoonah in Southeast Alaska; T43S, R61E,
S20, Copper River Meridian, USGS Quadrangle Juneau A5 NE; latitude
58.1351 and longitude -135.4506 (see Figure 1 of the application). The
project is located at the confluence of Icy Strait and Port Frederick
Inlet. The proposed cruise ship berth would be installed approximately
0.5 kilometer (km) (0.3 miles) east of the existing permanent cruise
ship berth in Icy Strait. A separate small craft lightering float would
be installed between two existing docks in Port Frederick Inlet on the
west side of Cannery Point (alternatively called Icy Strait Point; see
Figure 1 below and Figure 4 of the application).
[[Page 18497]]
[GRAPHIC] [TIFF OMITTED] TN01MY19.003
Icy Strait is part of Alaska's Inside Passage, a route for ships
through Southeast Alaska's network of islands, located between
Chichagof Island and the North American mainland. Port Frederick is a
24-km inlet that dips into northeast Chichagof Island from Icy Strait,
leading to Neka Bay and Salt Lake Bay. The inlet varies between 4 and
almost 6 km wide with a depth of up to 150 meters (m). The inlet near
the proposed project is 14 to 35 m deep (Figure 9, NOAA 2016). NMFS's
ShoreZone Mapper details the proposed project site as a semi-protected/
partially mobile/sediment or rock and sediment habitat class with
gravel beaches environmental sensitivity index (NMFS 2018c).
Detailed Description of Specific Activity
To construct a new cruise ship berth (Berth II), lightering float,
associated support structures, and pedestrian walkway connections to
shore, the project would require the following:
[ssquf] Installation of 62 temporary 30-inch (in) diameter steel
piles as templates to guide proper installation of permanent piles
(these piles would be removed prior to project completion);
[ssquf] Installation of 8 permanent 42-in diameter steel piles, 16
permanent 36-in diameter steel piles, and 18 permanent 24-in diameter
steel piles to support a new 500 feet (ft) x 50 ft floating pontoon
dock, its attached 400 ft x 12 ft small craft float, mooring
structures, and shore-access fixed-pier walkway (Figure 6 of the
application)
[ssquf] Installation of three permanent 30-in diameter steel piles
to support a 120 ft x 20 ft lightering float, and four permanent 16-in
diameter steel piles above the high tide line to construct a 12 ft x 40
ft fixed pier for lightering float shore access (Figure 7 of the
application);
[ssquf] Installation of bull rail, floating fenders, mooring
cleats, and mast lights. (Note: These components would be installed out
of the water.)
[ssquf] Socketing and rock anchoring to stabilize the piles.
Construction Sequence
In-water construction of Berth II would begin with installation of
an approximately 300-ft-long fixed pier. Temporary 30-in piles would be
driven into the bedrock by a vibratory hammer to create a template to
guide installation of the permanent piles. A frame would be welded
around the temporary piles. Permanent 36-in and 42-in piles would then
be driven into the bedrock using vibratory and impact pile driving.
Installation of the lightering float and fixed pier would begin
with removal of a single existing wood pile separate from the existing
wooden pier by direct-pull methods using a crane. Three 30-in steel
piles would then be driven in using a vibratory hammer in to support
the new lightering float structure. Additionally, (4) 16-in steel piles
would be installed with a vibratory hammer (on land) for the lightering
float's fixed pier and placement of a gangway to connect the two
components. The 16-in steel piles are not discussed further because
they occur on land and are not expected to impact species under water.
Installation and Removal of Temporary (Template) Piles
Temporary 30-in steel piles would be installed and removed using a
vibratory hammer (Table 1). If needed for stability, the contractor
would socket in up to 10 of these piles if a sufficient quantity of
overburden is not present (Table 1). Socketing is also known as down-
the-hole drilling or downhole drilling (DTH drilling) to secure a pile
to the bedrock. During socketing, the DTH hammer and under-reamer bit
drill a hole into the bedrock and then socket
[[Page 18498]]
the pile into the bedrock. We refer to it as socketing throughout this
document to clarify this method from rock anchoring, which also uses a
drill.
Installation of Permanent Piles
Eighteen permanent 24-in steel piles would be installed through
sand and gravel with a vibratory hammer (Table 1). All of the 18
permanent 24in steel piles will be secured into underlying bedrock with
socketing (Table 1). Socket depths are expected to be approximately
five ft (as determined by the geotechnical engineer). Two of the 24-in
steel piles may also be secured through rock anchoring (Table 1). Rock
anchoring is the method of drilling a shaft into the concrete, inside
of the existing pile, and filling it with concrete to stabilize the
pile. After a pile is impacted, the pile would be anchored using an 8in
diameter drilled shaft within the pile. Once the shaft is drilled, a
DTH hammer with an 8in diameter bit will be used to drill a shaft
(depth as determined by geotechnical engineer) into the bedrock and
filled with concrete to install the rock anchors.
Sixteen permanent 36-in steel piles and 8 permanent 42-in steel
piles would be driven through sand and gravel with a vibratory hammer
and impacted into bedrock (Table 1). After being impacted, all 24 of
these piles would be anchored using a smaller 33-in diameter drilled
shaft within the pile (Table 1). Once the shaft is drilled, a DTH
hammer with a 33-in diameter bit (isolated from the steel casing) will
be used to drill a shaft (depth as determined by geotechnical engineer)
into the bedrock and filled with concrete to install the rock anchors.
During this anchor drilling, the larger diameter piles would not be
touched by the drill; therefore, anchoring will not generate steel-on-
steel hammering noise (noise that is generated during socketing).
In addition, 3 permanent 30-in steel piles would be driven through
sand and gravel with a vibratory hammer only to support the lightering
float (Table 1).
Table 1--Pile Driving and Removal Activities Required for the Hoonah Berth II and Lightering Float
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Project Component
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Description Temporary pile Temporary pile Permanent pile Permanent pile Permanent pile Permanent pile
installation removal installation installation installation installation
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Diameter of Steel Pile (inches)......................... 30 30 24 30 36 42
# of Piles.............................................. 62 62 18 3 16 8
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Vibratory Pile Driving
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Total Quantity.......................................... 62 62 18 3 16 8
Max # Piles Vibrated per Day............................ 6 6 4 2 2 2
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Impact Pile Driving
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Total Quantity.......................................... 0 0 0 0 16 8
Max # Piles Impacted per Day............................ 0 0 0 0 4 2
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Socketed Pile Installation (Down-Hole Drilling)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total Quantity.......................................... 10 0 18 0 0 0
Max # Piles Socketed per Day............................ 2 0 2 0 0 0
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Rock Anchor Installation (Drilled Shaft)
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Total Quantity.......................................... 0 0 2 0 16 8
Diameter of Anchor...................................... .............. .............. 8 0 33 33
Max # Piles Anchored per Day............................ 0 0 1 0 2 2
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In addition to the activities described above, the proposed action
will involve other in-water construction and heavy machinery
activities. Other types of in-water work including with heavy machinery
will occur using standard barges, tug boats, barge-mounted excavators,
or clamshell equipment to place or remove material; and positioning
piles on the substrate via a crane (i.e., ``stabbing the pile'').
Workers will be transported from shore to the barge work platform by a
25-ft skiff with a 125-250 horsepower motor in the morning and at the
end of the work day. The travel distance will be less than 300 ft.
There could be multiple (up to eight) shore-to-barge trips during the
day; however, the area of travel will be relatively small and close to
shore. We do not expect any of these other in-water construction and
heavy machinery activities to take marine mammals as these activities
occur close to the shoreline (less than 300 feet), but as additional
mitigation, DPD is proposing a 10 m shutdown zone for these additional
in-water activities. Therefore, these other in-water construction and
heavy machinery activities will not be discussed further.
For further details on the proposed action and project components,
please refer to Section 1.2.4. and 1.2.5 of the application.
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 (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS's
website (https://www.fisheries.noaa.gov/find-species).
[[Page 18499]]
Table 2 lists all species with expected potential for occurrence in
the project area 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 (2016). PBR is defined by the MMPA as the
maximum number of animals, not including natural mortalities, that may
be removed from a marine mammal stock while allowing that stock to
reach or maintain its optimum sustainable population (as described in
NMFS's SARs). While no mortality is anticipated or authorized here, PBR
and annual serious injury and mortality from anthropogenic sources are
included here as gross indicators of the status of the species and
other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS's stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS's U.S. Pacific and Alaska SARs (Carretta et al., 2018; Muto et
al., 2018). All values presented in Table 2 are the most recent
available at the time of publication (draft SARS available online at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).
Table 2--Marine Mammals Occurrence in the Project Area
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ESA/ MMPA
status; Stock abundance (CV, Annual M/
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR SI \3\
\1\ abundance survey) \2\
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Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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Family Eschrichtiidae:
Gray Whale..................... Eschrichtius robustus. Eastern N Pacific.... -, -, N 26,960 (0.05, 25,849, 801............. 138
2016).
Family Balaenopteridae (rorquals):
Minke Whale.................... Balaenoptera Alaska............... -, -, N N/A (see SAR, N/A, UND............. 0
acutorostrata. see SAR).
Humpback Whale................. Megaptera novaeangliae Central N Pacific -, -, Y 10,103 (0.3, 7,890, 83.............. 25
(Hawaii and Mexico 2006) (Hawaii DPS
DPS). 9,487 \a\ Mexico DPS
606 \ a\).
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Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Physeteridae:
Sperm whale.................... Physeter macrocephalus North Pacific........ E, D, Y N/A (see SAR, N/A, See SAR......... 4.4
2015).
Family Delphinidae:
Killer Whale................... Orcinus orca.......... Alaska Resident...... -, -, N 2,347 c (N/A, 2347, 24.............. 1
2012).
Northern Resident.... -, -, N 261 c (N/A, 261, 1.96............ 0
2011).
West Coast Transient. -, -, N 243 c (N/A, 243, 2.4............. 0
2009).
Pacific White-Sided Dolphin.... Lagenorhynchus N Pacific............ -, -, N 26,880 (N/A, N/A, UND............. 0
obliquidens. 1990).
Family Phocoenidae (porpoises):
Dall's Porpoise................ Phocoenoides dalli.... AK................... -, -, N 83,400 (0.097, N/A, UND............. 38
1991).
Harbor Porpoise................ Phocoena phocoena..... Southeast Alaska..... -, -, Y see SAR (see SAR, see 8.9............. 34
SAR, 2012).
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Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
sea lions):
Steller Sea Lion............... Eumetopias jubatus.... Western DPS.......... E, D, Y 54,267 a (see SAR, 326............. 252
54,267, 2017).
Eastern DPS.......... T, D, Y 41,638 a (see SAR, 2498............ 108
41,638, 2015).
Family Phocidae (earless seals):
Harbor Seal.................... Phoca vitulina........ Glacier Bay/Icy -, -, N 7,210 (see SAR, 169............. 104
Strait. 5,647, 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: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
stock abundance. In some cases, CV is not applicable [explain if this is the case].
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
Note--Italicized species are not expected to be taken or proposed for authorization.
\a\ Under the MMPA humpback whales are considered a single stock (Central North Pacific); however, we have divided them here to account for distinct
population segments (DPSs) listed under the ESA. Using the stock assessment from Muto et al. 2018 for the Central North Pacific stock (10,103) and
calculations in Wade et al. 2016, 93.9% of the humpback whales in Southeast Alaska are expected to be from the Hawaii DPS and 6.1% are expected to be
from the Mexico DPS.
All species that could potentially occur in the proposed survey
areas are included in Table 2. In addition, the Northern sea otter
(Enhydra lutris kenyoni) may be found in the project area. However, sea
otters are managed by the U.S. Fish and Wildlife Service and are not
considered further in this document.
[[Page 18500]]
Minke Whale
In the North Pacific Ocean, minke whales occur from the Bering and
Chukchi seas south to near the Equator (Leatherwood et al., 1982). In
the northern part of their range, minke whales are believed to be
migratory, whereas, they appear to establish home ranges in the inland
waters of Washington and along central California (Dorsey et al. 1990).
Minke whales are observed in Alaska's nearshore waters during the
summer months (National Park Service (NPS) 2018). Minke whales are
usually sighted individually or in small groups of 2-3, but there are
reports of loose aggregations of hundreds of animals (NMFS 2018d).
Minke whales are rare in the action area, but they could be
encountered. During the construction of the first Icy Strait cruise
ship berth, a single minke was observed during the 135-day monitoring
period (June 2015 through January 2016) (BergerABAM 2016).
No abundance estimates have been made for the number of minke
whales in the entire North Pacific. However, some information is
available on the numbers of minke whales in some areas of Alaska. Line-
transect surveys were conducted in shelf and nearshore waters (within
30-45 nautical miles of land) in 2001-2003 from the Kenai Fjords in the
Gulf of Alaska to the central Aleutian Islands. Minke whale abundance
was estimated to be 1,233 (CV = 0.34) for this area (Zerbini et al.,
2006). This estimate has also not been corrected for animals missed on
the trackline. The majority of the sightings were in the Aleutian
Islands, rather than in the Gulf of Alaska, and in water shallower than
200 m. So few minke whales were seen during three offshore Gulf of
Alaska surveys for cetaceans in 2009, 2013, and 2015 that a population
estimate for this species in this area could not be determined (Rone et
al., 2017).
Humpback Whale
The humpback whale is distributed worldwide in all ocean basins and
a broad geographical range from tropical to temperate waters in the
Northern Hemisphere and from tropical to near-ice-edge waters in the
Southern Hemisphere. The humpback whales that forage throughout British
Colombia and Southeast Alaska undertake seasonal migrations from their
tropical calving and breeding grounds in winter to their high-latitude
feeding grounds in summer. They may be seen at any time of year in
Alaska, but most animals winter in temperate or tropical waters near
Hawaii. In the spring, the animals migrate back to Alaska where food is
abundant.
Within Southeast Alaska, humpback whales are found throughout all
major waterways and in a variety of habitats, including open-ocean
entrances, open-strait environments, near-shore waters, area with
strong tidal currents, and secluded bays and inlets. They tend to
concentrate in several areas, including northern Southeast Alaska.
Patterns of occurrence likely follow the spatial and temporal changes
in prey abundance and distribution with humpback whales adjusting their
foraging locations to areas of high prey density (Clapham 2000).
Humpback whales may be found in and around Chichagof Island, Icy
Strait, and Port Frederick Inlet at any given time. While many humpback
whales migrate to tropical calving and breeding grounds in winter, they
have been observed in Southeast Alaska in all months of the year
(Bettridge et al., 2015). Diet for humpback whales in the Glacier Bay/
Icy Strait area mainly consists of small schooling fish (capelin,
juvenile walleye pollock, sand lance, and Pacific herring) rather than
euphausiids (krill). They migrate to the northern reaches of Southeast
Alaska (Glacier Bay) during spring and early summer following these
fish and then move south towards Stephens Passage in early fall to feed
on krill, passing the project area on the way (Krieger and Wing 1986).
Over 32 years of humpback whale monitoring in the Glacier Bay/Icy
Strait area reveals a substantial decline in population since 2014; a
total of 164 individual whales were documented in 2016 during surveys
conducted from June-August, making it the lowest count since 2008
(Neilson et al., 2017)
During construction of the first Icy Strait cruise ship berth from
June 2015 through January 2016, humpback whales were observed in the
action area on 84 of the 135 days of monitoring; most often in
September and October. Up to 18 humpback sightings were reported on a
single day (October 2, 2015), and a total of 226 Level B harassments
were recorded during project construction (June 2015 through January
2016) (BergerABAM 2016).
Gray Whale
Gray whales are found exclusively in the North Pacific Ocean. The
Eastern North Pacific stock of gray whales inhabit the Chukchi,
Beaufort, and Bering Seas in northern Alaska in the summer and fall and
California and Mexico in the winter months, with a migration route
along the coastal waters of Southeast Alaska. Gray whales have also
been observed feeding in waters off Southeast Alaska during the summer
(NMFS 2018e).
The migration pattern of gray whales appears to follow a route
along the western coast of Southeast Alaska, traveling northward from
British Columbia through Hecate Strait and Dixon Entrance, passing the
west coast of Chichagof Island from late March to May (Jones et al.
1984, Ford et al. 2013). Since the project area is on the east coast of
Chichagof Island it is less likely there will be gray whales sighted
during project construction; however, the possibility exists.
During the 2016 construction of the first cruise ship terminal at
Icy Strait Point, no gray whales were seen during the 135-day
monitoring period (June 2015 through January 2016) (BergerABAM 2016).
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 (NMFS 2018f).
The Alaska Resident stock occurs from Southeast Alaska to the
Aleutian Islands and Bering Sea. The Northern Resident stock occurs
from Washington State through part of Southeast Alaska; and the West
Coast Transient stock occurs from California through Southeast Alaska
(Muto et al., 2018) and are thought to occur frequently in Southeast
Alaska (Straley 2017).
Transient killer whales can pass through the waters surrounding
Chichagof Island, in Icy Strait and Glacier Bay, feeding on marine
mammals. Because of their transient nature, it is difficult to predict
when they will be present in the area. Whales from the Alaska Resident
stock and the Northern Resident stock are thought to primarily feed on
fish. Like the transient killer whales, they can pass through Icy
Strait at any given time (North Gulf Oceanic Society 2018).
Killer whales were observed on 11 days during construction of the
first Icy Strait cruise ship berth during the 135-day monitoring period
(June 2015 through January 2016). Killer whales were observed a few
times a month. Usually a singular animal was observed, but a group
containing 8 individuals was seen in the action area on one occasion,
for a total of 24 animals observed during in-water work (BergerABAM
2016).
[[Page 18501]]
Pacific White-Sided Dolphin
Pacific white-sided dolphins are a pelagic species. They are found
throughout the temperate North Pacific Ocean, north of the coasts of
Japan and Baja California, Mexico (Muto et al., 2018). They are most
common between the latitudes of 38[deg] North and 47[deg] North (from
California to Washington). The distribution and abundance of Pacific
white-sided dolphins may be affected by large-scale oceanographic
occurrences, such as El Ni[ntilde]o, and by underwater acoustic
deterrent devices (NPS 2018a).
No Pacific white-sided dolphins were observed during construction
of the first cruise ship berth during the 135-day monitoring period
(June 2015 through January 2016) (BergerABAM 2016). They are rare in
the action area, likely because they are pelagic and prefer more open
water habitats than are found in Icy Strait and Port Frederick Inlet.
Pacific white-sided dolphins have been observed in Alaska waters in
groups ranging from 20 to 164 animals, with the sighting of 164 animals
occurring in Southeast Alaska near Dixon Entrance (Muto et al., 2018).
Dall's Porpoise
Dall's porpoises are widely distributed across the entire North
Pacific Ocean. They show some migration patterns, inshore and offshore
and north and south, based on morphology and type, geography, and
seasonality (Muto et al., 2018). They are common in most of the larger,
deeper channels in Southeast Alaska and are rare in most narrow
waterways, especially those that are relatively shallow and/or with no
outlets (Jefferson et al., 2019). In Southeast Alaska, abundance varies
with season.
Jefferson et al. (2019) recently published a report with survey
data spanning from 1991 to 2012 that studied Dall's porpoise density
and abundance in Southeast Alaska. They found Dall's porpoise were most
abundant in spring, observed with lower numbers in summer, and lowest
in fall. Surveys found Dall's porpoise to be common in Icy Strait and
sporadic with very low densities in Port Frederick (Jefferson et al.,
2019). During a 16-year survey of cetaceans in Southeast Alaska, Dall's
porpoises were commonly observed during spring, summer, and fall in the
nearshore waters of Icy Strait (Dahlheim et al., 2009). Dall's
porpoises were observed on two days during the 135-day monitoring
period (June 2015 through January 2016) of the construction of the
first cruise ship berth (BergerABAM 2016). Both were single individuals
transiting within the waters of Port Frederick in the vicinity of
Halibut Island. Dall's porpoises generally occur in groups from 2-12
individuals (NMFS 2018g).
Harbor Porpoise
In the eastern North Pacific Ocean, the Bering Sea and Gulf of
Alaska harbor porpoise stocks range from Point Barrow, along the Alaska
coast, and the west coast of North America to Point Conception,
California. The Southeast Alaska stock ranges from Cape Suckling,
Alaska to the northern border of British Columbia. Within the inland
waters of Southeast Alaska, harbor porpoises' distribution is clustered
with greatest densities observed in the Glacier Bay/Icy Strait region
and near Zarembo and Wrangell Islands and the adjacent waters of Sumner
Strait (Dahlheim et al., 2015). Harbor porpoises also were observed
primarily between June and September during construction of the Huna
Berth I cruise ship terminal project. Harbor porpoises were observed on
19 days during the 135-day monitoring period (June 2015 through January
2016) (BergerABAM 2016) and seen either singularly or in groups from
two to four animals.
There is no official stock abundance associated with the SARS for
harbor porpoise. Both aerial and vessel based surveys have been
conducted for this species. Aerial surveys of this stock were conducted
in June and July 1997 and resulted in an observed abundance estimate of
3,766 harbor porpoise (Hobbs and Waite 2010) and the surveys included a
subset of smaller bays and inlets. Correction factors for observer
perception bias and porpoise availability at the surface were used to
develop an estimated corrected abundance of 11,146 harbor porpoise in
the coastal and inside waters of Southeast Alaska (Hobbs and Waite
2010). Vessel based spanning the 22-year study (1991-2012) found the
relative abundance of harbor porpoise varied in the inland waters of
Southeast Alaska. Abundance estimated in 1991-1993 (N = 1,076; 95% CI =
910-1,272) was higher than the estimate obtained for 2006-2007 (N =
604; 95% CI = 468-780) but comparable to the estimate for 2010-2012 (N
= 975; 95% CI = 857-1,109; Dahlheim et al., 2015). These estimates
assume the probability of detection directly on the trackline to be
unity (g(0) = 1) because estimates of g(0) could not be computed for
these surveys. Therefore, these abundance estimates may be biased low
to an unknown degree. A range of possible g(0) values for harbor
porpoise vessel surveys in other regions is 0.5-0.8 (Barlow 1988, Palka
1995), suggesting that as much as 50 percent of the porpoise can be
missed, even by experienced observers.
Further, other vessel based survey data (2010-2012) for the inland
waters of Southeast Alaska, calculated abundance estimates for the
concentrations of harbor porpoise in the northern and southern regions
of the inland waters (Dahlheim et al. 2015). The resulting abundance
estimates are 398 harbor porpoise (CV = 0.12) in the northern inland
waters (including Cross Sound, Icy Strait, Glacier Bay, Lynn Canal,
Stephens Passage, and Chatham Strait) and 577 harbor porpoise (CV =
0.14) in the southern inland waters (including Frederick Sound, Sumner
Strait, Wrangell and Zarembo Islands, and Clarence Strait as far south
as Ketchikan). Because these abundance estimates have not been
corrected for g(0), these estimates are likely underestimates.
The vessel based surveys are not complete coverage of harbor
porpoise habitat and not corrected for bias and likely underestimate
the abundance. Whereas, the aerial survey in 1997, although outdated,
had better coverage of the range and is likely to be more of an
accurate representation of the stock abundance (11,146 harbor porpoise)
in the coastal and inside waters of Southeast Alaska.
Harbor Seal
Harbor seals range from Baja California north along the west 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 and, with local
movements associated with such factors as tide, weather, season, food
availability and reproduction.
Distribution of the Glacier Bay/Icy Strait stock, the only stock
considered in this application, ranges along the coast from Cape
Fairweather and Glacier Bay south through Icy Strait to Tenakee Inlet
on Chichagof Island (Muto et al., 2018).
The Glacier Bay/Icy Strait stock of harbor seals are common
residents of the action area and can occur on any given day in the
area, although they tend to be more abundant during the fall months
(Womble and Gende 2013). A total of 63 harbor seals were seen during 19
days of the 135-day monitoring period (June 2015 through January 2016)
[[Page 18502]]
(BergerABAM 2016), while none were seen during the 2018 test pile
program (SolsticeAK 2018). Harbor seals were primarily observed in
summer and early fall (June to September). Harbor seals were seen
singulary and in groups of two or more, but on one occasion, 22
individuals were observed hauled out on Halibut Rock, across Port
Frederick approximately 1.5 miles from the location of pile
installation activity (BergerABAM 2016).
There are two known harbor seal haulouts within the project area.
According to the AFSC list of harbor seal haulout locations, the
closest listed haulout (id 1,349: name CF39A) is located in Port
Frederick, approximately 1,850 m west (AFSC 2018). The group of 22
animals was observed using Halibut Rock (approximately 2,000 m from any
potential pile-driving activities) as a haulout.
Steller Sea Lion
Steller sea lions range along the North Pacific Rim from northern
Japan to California, with centers of abundance in the Gulf of Alaska
and Aleutian Islands (Loughlin et al., 1984).
Of the two Steller sea lion populations in Alaska, the Eastern DPS
includes sea lions born on rookeries from California north through
Southeast Alaska and the Western DPS includes those animals born on
rookeries from Prince William Sound westward, with an eastern boundary
set at 144[deg] W (NMFS 2018h). Both WDPS and EDPS Steller sea lions
are considered in this application because the WDPS are common within
the geographic area under consideration (north of Summer Strait) (Fritz
et al., 2013, NMFS 2013).
Steller sea lions are not known to migrate annually, but
individuals may widely disperse outside of the breeding season (late-
May to early-July), leading to intermixing of stocks (Jemison et al.
2013; Allen and Angliss 2015).
Steller sea lions are common in the inside waters of Southeast
Alaska. They are residents of the project vicinity and are common year-
round in the action area, moving their haulouts based on seasonal
concentrations of prey from exposed rookeries nearer the open Pacific
Ocean during the summer to more protected sites in the winter (Alaska
Department of Fish & Game (ADF&G) 2018). During the construction of the
existing Icy Strait cruise ship berth a total of 180 Steller sea lions
were observed on 47 days of the 135 monitoring days, amounting to an
average of 1.3 sightings per day (BergerABAM 2016). Steller sea lions
were frequently observed in groups of two or more individuals, but lone
individuals were also observed regularly (BergerABAM 2016). During a
test pile program performed at the project location by the Hoonah
Cruise Ship Dock Company in May 2018, a total of 15 Steller sea lions
were seen over the course of 7 hours in one day (SolsticeAK 2018). They
can occur in groups of 1-10 animals, but may congregate in larger
groups near rookeries and haulouts (NMFS 2018h). No documented
rookeries or haulouts are near the project area.
Critical habitat has been defined in Southeast Alaska at major
haulouts and major rookeries (50 CFR 226.202). The nearest rookery is
on the White Sisters Islands near Sitka and the nearest major haulouts
are at Benjamin Island, Cape Cross, and Graves Rocks. The White Sisters
rookery is located on the west side of Chichagof Island, about 72 km
southwest of the project area. Benjamin Island is about 60 km northeast
of Hoonah. Cape Cross and Graves Rocks are both about 70 km west of
Hoonah. Steller sea lions are known to haul out on land, docks, buoys,
and navigational markers. However, during the summer months when the
proposed project would be constructed Steller sea lions are less likely
to be in the protected waters around the project area, preferring
exposed rookeries on the western shores of Southeast Alaska.
Sperm Whales
Tagged sperm whales have been tracked within the Gulf of Alaska,
and multiple whales have been tracked in Chatham Strait, in Icy Strait,
and in the action area in 2014 and 2015 (http://seaswap.info/whaletrackerAccessed4/15/19). Tagging studies primarily show that sperm
whales use the deep water slope habitat extensively for foraging
(Mathias et al., 2012). Interaction studies between sperm whales and
the longline fishery have been focused along the continental slope of
the eastern Gulf of Alaska in water depths between about 1,970 and
3,280 ft (600 and 1,000 m) (Straley et al. 2005, Straley et al. 2014).
The known sperm whale habitat (these shelf-edge/slope waters of the
Gulf of Alaska) are far outside of the action area.
Also, more recently in November 2018 (4 whales) and March 2019 (2
whales), sperm whales have been observed in southern Lynn Canal, and on
March 20, 2019, NMFS performed a necropsy on a sperm whale that died
from trauma consistent with a ship strike. However, NMFS believes is
highly unlikely that sperm whales will occur in the action area where
pile driving activities will occur because they are generally found in
far deeper waters than those in which the project will occur.
Therefore, sperm whales are not being proposed for take authorization
and not discussed further.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Current data indicate that not all marine
mammal species have equal hearing capabilities (e.g., Richardson et
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect
this, Southall et al. (2007) recommended that marine mammals be divided
into functional hearing groups based on directly measured or estimated
hearing ranges on the basis of available behavioral response data,
audiograms derived using auditory evoked potential techniques,
anatomical modeling, and other data. Note that no direct measurements
of hearing ability have been successfully completed for mysticetes
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65
decibel (dB) threshold from the normalized composite audiograms, with
the exception for lower limits for low-frequency cetaceans where the
lower bound was deemed to be biologically implausible and the lower
bound from Southall et al. (2007) retained. Marine mammal hearing
groups and their associated hearing ranges are provided in Table 2.
Table 2--Marine Mammal Hearing Groups (NMFS, 2018)
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans (dolphins, 150 Hz to 160 kHz.
toothed whales, beaked whales, bottlenose
whales).
[[Page 18503]]
High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
cephalorhynchid, Lagenorhynchus cruciger &
L. australis).
Phocid pinnipeds (PW) (underwater) (true 50 Hz to 86 kHz.
seals).
Otariid pinnipeds (OW) (underwater) (sea 60 Hz to 39 kHz.
lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al. 2007) and PW pinniped (approximation).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Nine marine mammal species (7 cetacean and 2 pinniped (1 otariid and 1
phocid) species) have the reasonable potential to occur during the
proposed activities. Please refer to Table 2. Of the cetacean species
that may be present, three are classified as low-frequency cetaceans
(i.e., all mysticete species), two are classified as mid-frequency
cetaceans (i.e., all delphinid species), and two are classified as
high-frequency cetaceans (i.e., harbor porpoise and Dall's 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.
Acoustic effects on marine mammals during the specified activity
can occur from vibratory and impact pile driving as well as during
socketing and anchoring of the piles. The effects of underwater noise
from DPD's proposed activities have the potential to result in Level B
behavioral harassment of marine mammals in the vicinity of the action
area.
Description of Sound Sources
This section contains a brief technical background on sound, on the
characteristics of certain sound types, and on metrics used in this
proposal inasmuch as the information is relevant to the specified
activity and to a discussion of the potential effects of the specified
activity on marine mammals found later in this document. For general
information on sound and its interaction with the marine environment,
please see, e.g., Au and Hastings (2008); Richardson et al. (1995);
Urick (1983).
Sound travels in waves, the basic components of which are
frequency, wavelength, velocity, and amplitude. Frequency is the number
of pressure waves that pass by a reference point per unit of time and
is measured in hertz (Hz) or cycles per second. Wavelength is the
distance between two peaks or corresponding points of a sound wave
(length of one cycle). Higher frequency sounds have shorter wavelengths
than lower frequency sounds, and typically attenuate (decrease) more
rapidly, except in certain cases in shallower water. Amplitude is the
height of the sound pressure wave or the ``loudness'' of a sound and is
typically described using the relative unit of the decibel (dB). A
sound pressure level (SPL) in dB is described as the ratio between a
measured pressure and a reference pressure (for underwater sound, this
is 1 microPascal ([mu]Pa)), and is a logarithmic unit that accounts for
large variations in amplitude; therefore, a relatively small change in
dB corresponds to large changes in sound pressure. The source level
(SL) represents the SPL referenced at a distance of 1 m from the source
(referenced to 1 [mu]Pa), while the received level is the SPL at the
listener's position (referenced to 1 [mu]Pa).
Root mean square (rms) is the quadratic mean sound pressure over
the duration of an impulse. Root mean square is calculated by squaring
all of the sound amplitudes, averaging the squares, and then taking the
square root of the average (Urick, 1983). Root mean square accounts for
both positive and negative values; squaring the pressures makes all
values positive so that they may be accounted for in the summation of
pressure levels (Hastings and Popper, 2005). This measurement is often
used in the context of discussing behavioral effects, in part because
behavioral effects, which often result from auditory cues, may be
better expressed through averaged units than by peak pressures.
Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s)
represents the total energy in a stated frequency band over a stated
time interval or event, and considers both intensity and duration of
exposure. The per-pulse SEL is calculated over the time window
containing the entire pulse (i.e., 100 percent of the acoustic energy).
SEL is a cumulative metric; it can be accumulated over a single pulse,
or calculated over periods containing multiple pulses. Cumulative SEL
represents the total energy accumulated by a receiver over a defined
time window or during an event. Peak sound pressure (also referred to
as zero-to-peak sound pressure or 0-pk) is the maximum instantaneous
sound pressure measurable in the water at a specified distance from the
source, and is represented in the same units as the rms sound pressure.
When underwater objects vibrate or activity occurs, sound-pressure
waves are created. These waves alternately compress and decompress the
water as the sound wave travels. Underwater sound waves radiate in a
manner similar to ripples on the surface of a pond and may be either
directed in a beam or beams or may radiate in all directions
(omnidirectional sources), as is the case for sound produced by the
pile driving activity considered here. The compressions and
decompressions associated with sound waves are detected as changes in
pressure by aquatic life and man-made sound receptors such as
hydrophones.
Even in the absence of sound from the specified activity, the
underwater
[[Page 18504]]
environment is typically loud due to ambient sound, which is defined as
environmental background sound levels lacking a single source or point
(Richardson et al., 1995). The sound level of a region is defined by
the total acoustical energy being generated by known and unknown
sources. These sources may include physical (e.g., wind and waves,
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced
by marine mammals, fish, and invertebrates), and anthropogenic (e.g.,
vessels, dredging, construction) sound. A number of sources contribute
to ambient sound, including wind and waves, which are a main source of
naturally occurring ambient sound for frequencies between 200 hertz
(Hz) and 50 kilohertz (kHz) (Mitson, 1995). In general, ambient sound
levels tend to increase with increasing wind speed and wave height.
Precipitation can become an important component of total sound at
frequencies above 500 Hz, and possibly down to 100 Hz during quiet
times. Marine mammals can contribute significantly to ambient sound
levels, as can some fish and snapping shrimp. The frequency band for
biological contributions is from approximately 12 Hz to over 100 kHz.
Sources of ambient sound related to human activity include
transportation (surface vessels), dredging and construction, oil and
gas drilling and production, geophysical surveys, sonar, and
explosions. Vessel noise typically dominates the total ambient sound
for frequencies between 20 and 300 Hz. In general, the frequencies of
anthropogenic sounds are below 1 kHz and, if higher frequency sound
levels are created, they attenuate rapidly.
The sum of the various natural and anthropogenic sound sources that
comprise ambient sound at any given location and time depends not only
on the source levels (as determined by current weather conditions and
levels of biological and human activity) but also on the ability of
sound to propagate through the environment. In turn, sound propagation
is dependent on the spatially and temporally varying properties of the
water column and sea floor, and is frequency-dependent. As a result of
the dependence on a large number of varying factors, ambient sound
levels can be expected to vary widely over both coarse and fine spatial
and temporal scales. Sound levels at a given frequency and location can
vary by 10-20 decibels (dB) from day to day (Richardson et al., 1995).
The result is that, depending on the source type and its intensity,
sound from the specified activity may be a negligible addition to the
local environment or could form a distinctive signal that may affect
marine mammals.
Sounds are often considered to fall into one of two general types:
Pulsed and non-pulsed (defined in the following). 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). Please see
Southall et al. (2007) for an in-depth discussion of these concepts.
The distinction between these two sound types is not always obvious, as
certain signals share properties of both pulsed and non-pulsed sounds.
A signal near a source could be categorized as a pulse, but due to
propagation effects as it moves farther from the source, the signal
duration becomes longer (e.g., Greene and Richardson, 1988).
Pulsed sound sources (e.g., airguns, explosions, gunshots, sonic
booms, impact pile driving) produce signals that are brief (typically
considered to be less than one second), broadband, atonal transients
(ANSI, 1986, 2005; Harris, 1998; NIOSH, 1998; ISO, 2003) and occur
either as isolated events or repeated in some succession. Pulsed sounds
are all characterized by a relatively rapid rise from ambient pressure
to a maximal pressure value followed by a rapid decay period that may
include a period of diminishing, oscillating maximal and minimal
pressures, and generally have an increased capacity to induce physical
injury as compared with sounds that lack these features.
Non-pulsed sounds can be tonal, narrowband, or broadband, brief or
prolonged, and may be either continuous or intermittent (ANSI, 1995;
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals
of short duration but without the essential properties of pulses (e.g.,
rapid rise time). Examples of non-pulsed sounds include those produced
by vessels, aircraft, machinery operations such as drilling or
dredging, vibratory pile driving, and active sonar systems. The
duration of such sounds, as received at a distance, can be greatly
extended in a highly reverberant environment.
The impulsive sound generated by impact hammers is characterized by
rapid rise times and high peak levels. Vibratory hammers produce non-
impulsive, continuous noise at levels significantly lower than those
produced by impact hammers. Rise time is slower, reducing the
probability and severity of injury, and sound energy is distributed
over a greater amount of time (e.g., Nedwell and Edwards, 2002; Carlson
et al., 2005).
Acoustic Effects on Marine Mammals
We previously provided general background information on marine
mammal hearing (see ``Description of Marine Mammals in the Area of the
Specified Activity''). Here, we discuss the potential effects of sound
on marine mammals.
Note that, in the following discussion, we refer in many cases to a
review article concerning studies of noise-induced hearing loss
conducted from 1996-2015 (i.e., Finneran, 2015). For study-specific
citations, please see that work. Anthropogenic sounds cover a broad
range of frequencies and sound levels and can have a range of highly
variable impacts on marine life, from none or minor to potentially
severe responses, depending on received levels, duration of exposure,
behavioral context, and various other factors. The potential effects of
underwater sound from active acoustic sources can potentially result in
one or more of the following: Temporary or permanent hearing
impairment, non-auditory physical or physiological effects, behavioral
disturbance, stress, and masking (Richardson et al., 1995; Gordon et
al., 2004; Nowacek et al., 2007; Southall et al., 2007; G[ouml]tz et
al., 2009). The degree of effect is intrinsically related to the signal
characteristics, received level, distance from the source, and duration
of the sound exposure. In general, sudden, high level sounds can cause
hearing loss, as can longer exposures to lower level sounds. Temporary
or permanent loss of hearing will occur almost exclusively for noise
within an animal's hearing range. We first describe specific
manifestations of acoustic effects before providing discussion specific
to pile driving and removal activities.
Richardson et al. (1995) described zones of increasing intensity of
effect that might be expected to occur, in relation to distance from a
source and assuming that the signal is within an animal's hearing
range. First is the area within which the acoustic signal would be
audible (potentially perceived) to the animal but not strong enough to
elicit any overt behavioral or physiological response. The next zone
corresponds with the area where the signal is audible to the animal and
of sufficient intensity to elicit behavioral or physiological
responsiveness. Third is a zone within which, for signals of high
intensity, the received level is sufficient to potentially cause
discomfort or tissue damage to auditory or other systems. Overlaying
these zones to a certain extent is the
[[Page 18505]]
area within which masking (i.e., when a sound interferes with or masks
the ability of an animal to detect a signal of interest that is above
the absolute hearing threshold) may occur; the masking zone may be
highly variable in size.
We describe the more severe effects (i.e., certain non-auditory
physical or physiological effects) only briefly as we do not expect
that there is a reasonable likelihood that pile driving may result in
such effects (see below for further discussion). Potential effects from
explosive impulsive sound sources can range in severity from effects
such as behavioral disturbance or tactile perception to physical
discomfort, slight injury of the internal organs and the auditory
system, or mortality (Yelverton et al., 1973). Non-auditory
physiological effects or injuries that theoretically might occur in
marine mammals exposed to high level underwater sound or as a secondary
effect of extreme behavioral reactions (e.g., change in dive profile as
a result of an avoidance reaction) caused by exposure to sound include
neurological effects, bubble formation, resonance effects, and other
types of organ or tissue damage (Cox et al., 2006; Southall et al.,
2007; Zimmer and Tyack, 2007; Tal et al., 2015). The construction
activities considered here do not involve the use of devices such as
explosives or mid-frequency tactical sonar that are associated with
these types of effects.
Threshold Shift--Marine mammals exposed to high-intensity sound, or
to lower-intensity sound for prolonged periods, can experience hearing
threshold shift (TS), which is the loss of hearing sensitivity at
certain frequency ranges (Finneran, 2015). TS can be permanent (PTS),
in which case the loss of hearing sensitivity is not fully recoverable,
or temporary (TTS), in which case the animal's hearing threshold would
recover over time (Southall et al., 2007). Repeated sound exposure that
leads to TTS could cause PTS. In severe cases of PTS, there can be
total or partial deafness, while in most cases the animal has an
impaired ability to hear sounds in specific frequency ranges (Kryter,
1985).
When PTS occurs, there is physical damage to the sound receptors in
the ear (i.e., tissue damage), whereas TTS represents primarily tissue
fatigue and is reversible (Southall et al., 2007). In addition, other
investigators have suggested that TTS is within the normal bounds of
physiological variability and tolerance and does not represent physical
injury (e.g., Ward, 1997). Therefore, NMFS does not consider TTS to
constitute auditory injury.
Relationships between TTS and PTS thresholds have not been studied
in marine mammals, and there is no PTS data for cetaceans, but such
relationships are assumed to be similar to those in humans and other
terrestrial mammals. PTS typically occurs at exposure levels at least
several decibels above (a 40-dB threshold shift approximates PTS onset;
e.g., Kryter et al., 1966; Miller, 1974) that inducing mild TTS (a 6-dB
threshold shift approximates TTS onset; e.g., Southall et al. 2007).
Based on data from terrestrial mammals, a precautionary assumption is
that the PTS thresholds for impulse sounds (such as impact pile driving
pulses as received close to the source) are at least 6 dB higher than
the TTS threshold on a peak-pressure basis and PTS cumulative sound
exposure level thresholds are 15 to 20 dB higher than TTS cumulative
sound exposure level thresholds (Southall et al., 2007). Given the
higher level of sound or longer exposure duration necessary to cause
PTS as compared with TTS, it is considerably less likely that PTS could
occur.
TTS is the mildest form of hearing impairment that can occur during
exposure to sound (Kryter, 1985). While experiencing TTS, the hearing
threshold rises, and a sound must be at a higher level in order to be
heard. In terrestrial and marine mammals, TTS can last from minutes or
hours to days (in cases of strong TTS). In many cases, hearing
sensitivity recovers rapidly after exposure to the sound ends. Few data
on sound levels and durations necessary to elicit mild TTS have been
obtained for marine mammals.
Marine mammal hearing plays a critical role in communication with
conspecifics, and interpretation of environmental cues for purposes
such as predator avoidance and prey capture. 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. 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 occurs during a time where ambient noise is lower and there
are not as many competing sounds present. Alternatively, a larger
amount and longer duration of TTS sustained during time when
communication is critical for successful mother/calf interactions could
have more serious impacts.
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 three species of pinnipeds (northern elephant
seal, harbor seal, and California sea lion) 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. There
are no data 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 NMFS (2018).
Behavioral Effects--Behavioral disturbance may include a variety of
effects, including subtle changes in behavior (e.g., minor or brief
avoidance of an area or changes in vocalizations), more conspicuous
changes in similar behavioral activities, and more sustained and/or
potentially severe reactions, such as displacement from or abandonment
of high-quality habitat. 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).
Please see Appendices B-C of Southall et al. (2007) for a review of
studies involving marine mammal behavioral responses to sound.
Habituation can occur when an animal's response to a stimulus wanes
with repeated exposure, usually in the absence of unpleasant associated
events (Wartzok et al., 2003). Animals are most
[[Page 18506]]
likely to habituate to sounds that are predictable and unvarying. It is
important to note that habituation is appropriately considered as a
``progressive reduction in response to stimuli that are perceived as
neither aversive nor beneficial,'' rather than as, more generally,
moderation in response to human disturbance (Bejder et al., 2009). The
opposite process is sensitization, when an unpleasant experience leads
to subsequent responses, often in the form of avoidance, at a lower
level of exposure. As noted, behavioral state may affect the type of
response. For example, animals that are resting may show greater
behavioral change in response to disturbing sound levels than animals
that are highly motivated to remain in an area for feeding (Richardson
et al., 1995; NRC, 2003; Wartzok et al., 2003). Controlled experiments
with captive marine mammals have showed pronounced behavioral
reactions, including avoidance of loud sound sources (Ridgway et al.,
1997; Finneran et al., 2003). Observed responses of wild marine mammals
to loud pulsed sound sources (typically airguns or acoustic harassment
devices) have been varied but often consist of avoidance behavior or
other behavioral changes suggesting discomfort (Morton and Symonds,
2002; see also Richardson et al., 1995; Nowacek et al., 2007). However,
many delphinids approach low-frequency airgun source vessels with no
apparent discomfort or obvious behavioral change (e.g., Barkaszi et
al., 2012), indicating the importance of frequency output in relation
to the species' hearing sensitivity.
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). However, there are broad categories of potential response, which
we describe in greater detail here, that include alteration of dive
behavior, alteration of foraging behavior, effects to breathing,
interference with or alteration of vocalization, avoidance, and flight.
Changes in dive behavior can vary widely and may consist of
increased or decreased dive times and surface intervals as well as
changes in the rates of ascent and descent during a dive (e.g., Frankel
and Clark, 2000; Costa et al., 2003; Ng and Leung, 2003; Nowacek et
al., 2004; Goldbogen et al., 2013a, 2013b). Variations in dive behavior
may reflect interruptions in biologically significant activities (e.g.,
foraging) or they may be of little biological significance. The impact
of an alteration to dive behavior resulting from an acoustic exposure
depends on what the animal is doing at the time of the exposure and the
type and magnitude of the response.
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.
Variations in respiration naturally vary with different behaviors
and alterations to breathing rate as a function of acoustic exposure
can be expected to co-occur with other behavioral reactions, such as a
flight response or an alteration in diving. However, respiration rates
in and of themselves may be representative of annoyance or an acute
stress response. Various studies have shown that respiration rates may
either be unaffected or could increase, depending on the species and
signal characteristics, again highlighting the importance in
understanding species differences in the tolerance of underwater noise
when determining the potential for impacts resulting from anthropogenic
sound exposure (e.g., Kastelein et al., 2001, 2005, 2006; Gailey et
al., 2007; Gailey et al., 2016).
Marine mammals vocalize for different purposes and across multiple
modes, such as whistling, echolocation click production, calling, and
singing. Changes in vocalization behavior in response to anthropogenic
noise can occur for any of these modes and may result from a need to
compete with an increase in background noise or may reflect increased
vigilance or a startle response. For example, in the presence of
potentially masking signals, humpback whales and killer whales have
been observed to increase the length of their songs (Miller et al.,
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales
have been observed to shift the frequency content of their calls upward
while reducing the rate of calling in areas of increased anthropogenic
noise (Parks et al., 2007). In some cases, animals may cease sound
production during production of aversive signals (Bowles et al., 1994).
Avoidance is the displacement of an individual from an area or
migration path as a result of the presence of a sound or other
stressors, and is one of the most obvious manifestations of disturbance
in marine mammals (Richardson et al., 1995). For example, gray whales
are known to change direction--deflecting from customary migratory
paths--in order to avoid noise from airgun surveys (Malme et al.,
1984). Avoidance may be short-term, with animals returning to the area
once the noise has ceased (e.g., Bowles et al., 1994; Goold, 1996;
Stone et al., 2000; Morton and Symonds, 2002; Gailey et al., 2007).
Longer-term displacement is possible, however, which may lead to
changes in abundance or distribution patterns of the affected species
in the affected region if habituation to the presence of the sound does
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann
et al., 2006).
A flight response is a dramatic change in normal movement to a
directed and rapid movement away from the perceived location of a sound
source. The flight response differs from other avoidance responses in
the intensity of the response (e.g., directed movement, rate of
travel). Relatively little information on flight responses of marine
mammals to anthropogenic signals exist, although observations of flight
responses to the presence of predators have occurred (Connor and
Heithaus, 1996). The result of a flight response could range from
brief, temporary exertion and displacement from the area where the
signal provokes flight to, in extreme cases, marine mammal strandings
(Evans and England, 2001). However, it should be noted that response to
a perceived predator does not necessarily invoke flight (Ford and
Reeves, 2008), and whether individuals are solitary or in groups may
influence the response.
[[Page 18507]]
Behavioral disturbance can also impact marine mammals in more
subtle ways. Increased vigilance may result in costs related to
diversion of focus and attention (i.e., when a response consists of
increased vigilance, it may come at the cost of decreased attention to
other critical behaviors such as foraging or resting). These effects
have generally not been demonstrated for marine mammals, but studies
involving fish and terrestrial animals have shown that increased
vigilance may substantially reduce feeding rates (e.g., Beauchamp and
Livoreil, 1997; Fritz et al., 2002; Purser and Radford, 2011). In
addition, chronic disturbance can cause population declines through
reduction of fitness (e.g., decline in body condition) and subsequent
reduction in reproductive success, survival, or both (e.g., Harrington
and Veitch, 1992; Daan et al., 1996; Bradshaw et al., 1998). However,
Ridgway et al. (2006) reported that increased vigilance in bottlenose
dolphins exposed to sound over a five-day period did not cause any
sleep deprivation or stress effects.
Many animals perform vital functions, such as feeding, resting,
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption
of such functions resulting from reactions to stressors such as sound
exposure are more likely to be significant if they last more than one
diel cycle or recur on subsequent days (Southall et al., 2007).
Consequently, a behavioral response lasting less than one day and not
recurring on subsequent days is not considered particularly severe
unless it could directly affect reproduction or survival (Southall et
al., 2007). Note that there is a difference between multi-day
substantive behavioral reactions and multi-day anthropogenic
activities. For example, just because an activity lasts for multiple
days does not necessarily mean that individual animals are either
exposed to activity-related stressors for multiple days or, further,
exposed in a manner resulting in sustained multi-day substantive
behavioral responses.
Stress Responses--An animal's perception of a threat may be
sufficient to trigger stress responses consisting of some combination
of behavioral responses, autonomic nervous system responses,
neuroendocrine responses, or immune responses (e.g., Seyle, 1950;
Moberg, 2000). In many cases, an animal's first and sometimes most
economical (in terms of energetic costs) response is behavioral
avoidance of the potential stressor. Autonomic nervous system responses
to stress typically involve changes in heart rate, blood pressure, and
gastrointestinal activity. These responses have a relatively short
duration and may or may not have a significant long-term effect on an
animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that
are affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been
implicated in failed reproduction, altered metabolism, reduced immune
competence, and behavioral disturbance (e.g., Moberg, 1987; Blecha,
2000). Increases in the circulation of glucocorticoids are also equated
with stress (Romano et al., 2004).
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and ``distress'' is the cost of
the response. During a stress response, an animal uses glycogen stores
that can be quickly replenished once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other functions. This state of
distress will last until the animal replenishes its energetic reserves
sufficient to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well-studied through
controlled experiments and for both laboratory and free-ranging animals
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003;
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to
exposure to anthropogenic sounds or other stressors and their effects
on marine mammals have also been reviewed (Fair and Becker, 2000;
Romano et al., 2002b) and, more rarely, studied in wild populations
(e.g., Romano et al., 2002a). For example, Rolland et al. (2012) found
that noise reduction from reduced ship traffic in the Bay of Fundy was
associated with decreased stress in North Atlantic right whales. These
and other studies lead to a reasonable expectation that some marine
mammals will experience physiological stress responses upon exposure to
acoustic stressors and that it is possible that some of these would be
classified as ``distress.'' In addition, any animal experiencing TTS
would likely also experience stress responses (NRC, 2003).
Auditory 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; Erbe et al.,
2016). 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.,
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.
Under certain circumstances, marine mammals experiencing
significant masking could also be impaired from maximizing their
performance fitness in survival and reproduction. Therefore, when the
coincident (masking) sound is man-made, it may be considered harassment
when disrupting or altering critical behaviors. It is important to
distinguish TTS and PTS, which persist after the sound exposure, from
masking, which occurs during the sound exposure. Because masking
(without resulting in TS) is not associated with abnormal physiological
function, it is not considered a physiological effect, but rather a
potential behavioral effect.
The frequency range of the potentially masking sound is important
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation
sounds produced by odontocetes but are more likely to affect detection
of mysticete communication calls and other potentially important
natural sounds such as those produced by surf and some prey species.
The masking of communication signals by anthropogenic noise may be
considered as a reduction in the communication space of animals (e.g.,
Clark et al., 2009) and may result in energetic or other costs as
animals change their vocalization behavior (e.g., Miller et al., 2000;
Foote et al., 2004; Parks et al., 2007; Di Iorio and Clark, 2009; Holt
et
[[Page 18508]]
al., 2009). Masking can be reduced in situations where the signal and
noise come from different directions (Richardson et al., 1995), through
amplitude modulation of the signal, or through other compensatory
behaviors (Houser and Moore, 2014). Masking can be tested directly in
captive species (e.g., Erbe, 2008), but in wild populations it must be
either modeled or inferred from evidence of masking compensation. There
are few studies addressing real-world masking sounds likely to be
experienced by marine mammals in the wild (e.g., Branstetter et al.,
2013).
Masking affects both senders and receivers of acoustic signals and
can potentially have long-term chronic effects on marine mammals at the
population level as well as at the individual level. Low-frequency
ambient sound levels have increased by as much as 20 dB (more than
three times in terms of SPL) in the world's ocean from pre-industrial
periods, with most of the increase from distant commercial shipping
(Hildebrand, 2009). All anthropogenic sound sources, but especially
chronic and lower-frequency signals (e.g., from vessel traffic),
contribute to elevated ambient sound levels, thus intensifying masking.
Potential Effects of DPD's Activity--As described previously (see
``Description of Active Acoustic Sound Sources''), DPD proposes to
conduct pile driving, including impact and vibratory driving (inclusive
of socketing and anchoring). The effects of pile driving on marine
mammals are dependent on several factors, including the size, type, and
depth of the animal; the depth, intensity, and duration of the pile
driving sound; the depth of the water column; the substrate of the
habitat; the standoff distance between the pile and the animal; and the
sound propagation properties of the environment. With both types, it is
likely that the pile driving could result in temporary, short term
changes in an animal's typical behavioral patterns and/or avoidance of
the affected area. These behavioral changes may include (Richardson et
al., 1995): 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; and/or flight
responses.
The biological significance of many of these behavioral
disturbances is difficult to predict, especially if the detected
disturbances appear minor. However, the consequences of behavioral
modification could be expected to be biologically significant if the
change affects growth, survival, or reproduction. Significant
behavioral modifications that could lead to effects on growth,
survival, or reproduction, such as drastic changes in diving/surfacing
patterns or significant habitat abandonment are extremely unlikely in
this area (i.e., shallow waters in modified industrial areas).
Whether impact or vibratory driving, sound sources would be active
for relatively short durations, with relation to potential for masking.
The frequencies output by pile driving activity are lower than those
used by most species expected to be regularly present for communication
or foraging. We expect insignificant impacts from masking, and any
masking event that could possibly rise to Level B harassment under the
MMPA would occur concurrently within the zones of behavioral harassment
already estimated for vibratory and impact pile driving, and which have
already been taken into account in the exposure analysis.
Anticipated Effects on Marine Mammal Habitat
The proposed activities would not result in permanent impacts to
habitats used directly by marine mammals except the actual footprint of
the project. The footprint of the project is small, and equal to the
area of the cruise ship berth and associated pile placement. The small
lightering facility nearer to the cannery would not impact any marine
mammal habitat since its proposed location is in between two existing,
heavily-traveled docks, and within an active marine commercial and
tourist area. Over time, marine mammals may be deterred from using
habitat near the project area, due to an increase in vessel traffic and
tourist activity in this area. The number of cruise ships traveling to
Hoonah is expected to increase. Hoonah's increased traffic as a top
Alaskan cruise port-of-call is already occurring. However, this project
would decrease small vessel traffic to and from cruise ships unable to
dock at the existing berth.
The proposed activities may have potential short-term impacts to
food sources such as forage fish. The proposed activities could also
affect acoustic habitat (see masking discussion above), but meaningful
impacts are unlikely. There are no known foraging hotspots, or other
ocean bottom structures of significant biological importance to marine
mammals present in the marine waters in the vicinity of the project
areas. Therefore, the main impact issue associated with the proposed
activity would be temporarily elevated sound levels and the associated
direct effects on marine mammals, as discussed previously. The most
likely impact to marine mammal habitat occurs from pile driving effects
on likely marine mammal prey (i.e., fish) near where the piles are
installed. Impacts to the immediate substrate during installation and
removal of piles are anticipated, but these would be limited to minor,
temporary suspension of sediments, which could impact water quality and
visibility for a short amount of time, but which would not be expected
to have any effects on individual marine mammals. Impacts to substrate
are therefore not discussed further.
Effects to Prey--Sound may affect marine mammals through impacts on
the abundance, behavior, or distribution of prey species (e.g.,
crustaceans, cephalopods, fish, zooplankton). Marine mammal prey varies
by species, season, and location and, for some, is not well documented.
Here, we describe studies regarding the effects of noise on known
marine mammal prey.
Fish utilize the soundscape and components of sound in their
environment to perform important functions such as foraging, predator
avoidance, mating, and spawning (e.g., Zelick et al., 1999; Fay, 2009).
Depending on their hearing anatomy and peripheral sensory structures,
which vary among species, fishes hear sounds using pressure and
particle motion sensitivity capabilities and detect the motion of
surrounding water (Fay et al., 2008). The potential effects of noise on
fishes depends on the overlapping frequency range, distance from the
sound source, water depth of exposure, and species-specific hearing
sensitivity, anatomy, and physiology. Key impacts to fishes may include
behavioral responses, hearing damage, barotrauma (pressure-related
injuries), and mortality.
Fish react to sounds which are especially strong and/or
intermittent low-frequency sounds, and behavioral responses such as
flight or avoidance are the most likely effects. Short duration, sharp
sounds can cause overt or subtle changes in fish behavior and local
distribution. The reaction of fish to noise depends on the
physiological state of the fish, past exposures, motivation (e.g.,
feeding, spawning, migration), and other environmental factors.
Hastings and Popper (2005) identified several
[[Page 18509]]
studies that suggest fish may relocate to avoid certain areas of sound
energy. Additional studies have documented effects of pile driving on
fish, although several are based on studies in support of large,
multiyear bridge construction projects (e.g., Scholik and Yan, 2001,
2002; Popper and Hastings, 2009). Several studies have demonstrated
that impulse sounds might affect the distribution and behavior of some
fishes, potentially impacting foraging opportunities or increasing
energetic costs (e.g., Fewtrell and McCauley, 2012; Pearson et al.,
1992; Skalski et al., 1992; Santulli et al., 1999; Paxton et al.,
2017). However, some studies have shown no or slight reaction to
impulse sounds (e.g., Pena et al., 2013; Wardle et al., 2001; Jorgenson
and Gyselman, 2009; Cott et al., 2012). More commonly, though, the
impacts of noise on fish are temporary.
SPLs of sufficient strength have been known to cause injury to fish
and fish mortality. However, in most fish species, hair cells in the
ear continuously regenerate and loss of auditory function likely is
restored when damaged cells are replaced with new cells. Halvorsen et
al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours
for one species. Impacts would be most severe when the individual fish
is close to the source and when the duration of exposure is long.
Injury caused by barotrauma can range from slight to severe and can
cause death, and is most likely for fish with swim bladders. Barotrauma
injuries have been documented during controlled exposure to impact pile
driving (Halvorsen et al., 2012b; Casper et al., 2013).
The action area supports marine habitat for prey species including
large populations of anadromous fish including Pacific salmon (five
species), cutthroat and steelhead trout, and Dolly Varden (NMFS 2018i)
and other species of marine fish such as halibut, rock sole, sculpins,
Pacific cod, herring, and eulachon (NMFS 2018j). The most likely impact
to fish from pile driving activities at the project areas would be
temporary behavioral avoidance of the area. The duration of fish
avoidance of an area after pile driving stops is unknown, but a rapid
return to normal recruitment, distribution and behavior is anticipated.
In general, impacts to marine mammal prey species are expected to be
minor and temporary due to the expected short daily duration of
individual pile driving events and the relatively small areas being
affected.
The following essential fish habitat (EFH) species may occur in the
project area during at least one phase of their lifestage: Chum Salmon
(Oncorhynchus keta), Pink Salmon (O. gorbuscha), Coho Salmon (O.
kisutch), Sockeye Salmon (O. nerka), and Chinook Salmon (O.
tshawytscha). No habitat areas of particular concern or EFH areas
protected from fishing are identified near the project area (NMFS
2018i). There are no documented anadromous fish streams in the project
area. The closest documented anadromous fish steam is approximately 2.5
miles southeast of the project area (ADF&G 2018a).
The area impacted by the project is relatively small compared to
the available habitat in Port Frederick Inlet and Icy Strait. Any
behavioral avoidance by fish of the disturbed area would still leave
significantly large areas of fish and marine mammal foraging habitat in
the nearby vicinity. As described in the preceding, the potential for
DPD's construction to affect the availability of prey to marine mammals
or to meaningfully impact the quality of physical or acoustic habitat
is considered to be insignificant. Effects to habitat will not be
discussed further in this document.
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.
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).
Take of marine mammals incidental to DPD's pile driving and removal
activities (as well as during socketing and anchoring) could occur as a
result of Level A and Level B harassment. Below we describe how the
potential take is estimated. 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--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) and above 160 dB re 1
[mu]Pa (rms) for impulsive sources (e.g., impact pile driving). DPD's
proposed activity includes the use of continuous (vibratory pile
driving) and impulsive (impact pile driving) sources, and therefore the
120 and 160 dB re 1 [mu]Pa (rms) are applicable.
Level A harassment--NMFS' Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0)
(Technical Guidance, 2018) identifies dual criteria to assess auditory
injury (Level A harassment) to five different
[[Page 18510]]
marine mammal groups (based on hearing sensitivity) as a result of
exposure to noise. The technical guidance identifies the received
levels, or thresholds, above which individual marine mammals are
predicted to experience changes in their hearing sensitivity for all
underwater anthropogenic sound sources, and reflects the best available
science on the potential for noise to affect auditory sensitivity by:
[ssquf] Dividing sound sources into two groups (i.e., impulsive and
non-impulsive) based on their potential to affect hearing sensitivity;
[ssquf] Choosing metrics that best address the impacts of noise on
hearing sensitivity, i.e., sound pressure level (peak SPL) and sound
exposure level (SEL) (also accounts for duration of exposure); and
[ssquf] Dividing marine mammals into hearing groups and developing
auditory weighting functions based on the science supporting that not
all marine mammals hear and use sound in the same manner.
These thresholds were developed by compiling and synthesizing the
best available science, and are provided in Table 3 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.
DPD's pile driving and removal activity includes the use of
impulsive (impact pile driving) and non-impulsive (vibratory pile
driving and removal) sources.
Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift (Auditory Injury)
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW).................. Cell 7: Lpk,flat: 218 dB; Cell 8: LE,PW,24h: 201 dB.
(Underwater)........................... LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW)................. Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
(Underwater)........................... LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
has a reference value of 1[mu]Pa\2\s. In this Table, thresholds are abbreviated to reflect American National
Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that will feed into identifying the area ensonified above the
acoustic thresholds, which include source levels and transmission loss
coefficient.
Sound Propagation
Transmission loss (TL) is the decrease in acoustic intensity as an
acoustic pressure wave propagates out from a source. TL parameters vary
with frequency, temperature, sea conditions, current, source and
receiver depth, water depth, water chemistry, and bottom composition
and topography. The general formula for underwater TL is:
TL = B * log10(R1/R2), where:
B = transmission loss coefficient (assumed to be 15)
R1 = the distance of the modeled SPL from the driven
pile, and
R2 = the distance from the driven pile of the initial
measurement.
This formula neglects loss due to scattering and absorption, which
is assumed to be zero here. The degree to which underwater sound
propagates away from a sound source is dependent on a variety of
factors, most notably the water bathymetry and presence or absence of
reflective or absorptive conditions including in-water structures and
sediments. Spherical spreading occurs in a perfectly unobstructed
(free-field) environment not limited by depth or water surface,
resulting in a 6 dB reduction in sound level for each doubling of
distance from the source (20*log(range)). Cylindrical spreading occurs
in an environment in which sound propagation is bounded by the water
surface and sea bottom, resulting in a reduction of 3 dB in sound level
for each doubling of distance from the source (10*log(range)). As is
common practice in coastal waters, here we assume practical spreading
loss (4.5 dB reduction in sound level for each doubling of distance).
Practical spreading is a compromise that is often used under conditions
where water depth increases as the receiver moves away from the
shoreline, resulting in an expected propagation environment that would
lie between spherical and cylindrical spreading loss conditions.
Sound Source Levels
The intensity of pile driving sounds is greatly influenced by
factors such as the type of piles, hammers, and the physical
environment in which the activity takes place. There are source level
measurements available for certain pile types and sizes from the
similar environments recorded from underwater pile driving projects in
Alaska (e.g., JASCO Reports--Denes et al., 2017 and Austin et al.,
2016).) that were evaluated and used as proxy sound source levels to
determine reasonable sound source levels likely result from DPD's pile
driving and removal activities (Table 4). Many source levels used were
more conservation as the values were from larger pile sizes.
[[Page 18511]]
Table 4--Assumed Sound Source Levels
----------------------------------------------------------------------------------------------------------------
Activity Sound source level at 10 meters Sound source
----------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving/Removal
----------------------------------------------------------------------------------------------------------------
24-in steel pile permanent......... 161.9 SPL............................ The 24-in-diameter source level for
30-in steel pile temporary 161.9 SPL............................ vibratory driving are proxy from
installation. 161.9 SPL............................ median measured source levels from
30-in steel pile removal........... 161.9 SPL............................ pile driving of 30-in-diameter
30-in steel pile permanent piles to construct the Ketchikan
installation. Ferry Terminal (Denes et al., 2016,
Table 72).
36-in steel pile permanent......... 168.2 SPL............................ The 36-in and 42-in pile source
42-in steel pile permanent......... 168.2 SPL............................ level is a proxy from median
measured source level from
vibratory hammering of 48-in piles
for the Port of Anchorage test pile
project (Austin et al., 2016).
----------------------------------------------------------------------------------------------------------------
Impact Pile Driving 5 6
----------------------------------------------------------------------------------------------------------------
36-in steel pile permanent......... 186.7 SEL/198.6 SPL.................. The 36-in and 42-in diameter pile
42-in steel pile permanent......... 186.7 SEL/198.6 SPL.................. source level is a proxy from median
measured source level from impact
hammering of 48-in piles for the
Port of Anchorage test pile project
(Austin et al., 2016).
----------------------------------------------------------------------------------------------------------------
Socketed Pile Installation
----------------------------------------------------------------------------------------------------------------
24-in steel pile permanent......... 166.2 SPL............................ The socketing and rock anchor source
30-in steel pile temporary......... 166.2 SPL............................ level is a proxy from median
measured source level from down-
hole drilling of 24-in-diameter
piles to construct the Kodiak Ferry
Terminal (Denes et al., 2016, Table
72).
----------------------------------------------------------------------------------------------------------------
Rock Anchor Installation
----------------------------------------------------------------------------------------------------------------
8-in anchor permanent (for 24-in 166.2 SPL............................ The socketing and rock anchor source
piles). 166.2 SPL............................ level is a proxy from median
33-in anchor permanent (for 36-in 166.2 SPL............................ measured source level from down-
piles). hole drilling of 24-in-diameter
33-in anchor permanent (for 42-in piles to construct the Kodiak Ferry
piles). Terminal (Denes et al., 2016, Table
72).
----------------------------------------------------------------------------------------------------------------
Notes: Denes et al., 2016--Alaska Department of Transportation's Hydroacoustic Pile Driving Noise Study--
Comprehensive Report and Austin et al., 2016--Hydroacoustic Monitoring Report: Anchorage Port Modernization
Project Test Pile Program. Version 3.0. Technical report by JASCO Applied Sciences for Kiewit Infrastructure
West Co.
Level A Harassment
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 from
impact and vibratory pile driving), 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 (Tables 5 and 6), and the resulting isopleths
are reported below (Table 7).
Table 5--NMFS Technical Guidance (2018) User Spreadsheet Input To Calculate PTS Isopleths for Vibratory Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
User spreadsheet input--vibratory pile driving/anchoring and socketing Spreadsheet Tab A.1 vibratory pile driving used
---------------------------------------------------------------------------------------------------------------------------------------------------------
30-in piles 30-in piles 24-in and
24-in piles (temporary (temporary 30-in piles 36-in piles 42-in piles 8-in 33-in 30-in
(permanent) install) removal) (permanent) (permanent) (permanent) anchoring anchoring socketing
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source Level (RMS SPL)................... 161.9 161.9 161.9 161.9 168.2 168.2 166.2 166.2 166.2
Weighting Factor Adjustment (kHz)........ 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
Number of piles within 24-hr period...... 4 6 6 2 2 2 1 2 2
Duration to drive a single pile (min).... 10 20 10 30 30 60 60 240 60
Propagation (xLogR)...................... 15 15 15 15 15 15 15 15 15
Distance of source level measurement 10 10 10 10 10 10 10 10
(meters)*...............................
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 18512]]
Table 6--NMFS Technical Guidance (2018) User Spreadsheet Input To
Calculate PTS Isopleths for Impact Pile Driving
------------------------------------------------------------------------
User spreadsheet input--impact pile driving Spreadsheet Tab E.1 impact
pile driving used
-------------------------------------------------------------------------
36-in piles 42-in piles
(permanent) (permanent)
------------------------------------------------------------------------
Source Level (Single Strike/shot SEL)... 186.7 186.7
Weighting Factor Adjustment (kHz)....... 2 2
Number of strikes per pile.............. 100 135
Number of piles per day................. 4 2
Propagation (xLogR)..................... 15 15
Distance of source level measurement 10 10
(meters)...............................
------------------------------------------------------------------------
Table 7--NMFS Technical Guidance (2018) User Spreadsheet Outputs To Calculate Level A Harassment PTS Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
User spreadsheet output PTS isopleths (meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment
-------------------------------------------------------------------------------
Activity Sound source level at 10 m High-
Low- frequency Mid- frequency frequency Phocid Otariid
cetaceans cetaceans cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving/Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in steel installation.................. 161.9 SPL \1\............... 6.0 0.5 8.8 3.6 0.3
30-in steel temporary installation........ 161.9 SPL \1\............... 12.4 1.1 18.4 7.6 0.5
30-in steel removal....................... 161.9 SPL \1\............... 7.8 0.7 11.6 4.8 0.3
30-in steel permanent installation........ 161.9 SPL \1\............... 7.8 0.7 11.6 4.8 0.3
36-in steel permanent installation........ 168.2 SPL \2\............... 20.6 1.8 30.5 12.5 0.9
42-in steel permanent installation........ 168.2 SPL \2\............... 32.7 2.9 48.4 19.9 1.4
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in steel permanent installation........ 186.7 SEL/198.6 SPL \2\..... 956.7 34.0 1,139.6 512.0 37.3
42-in steel permanent installation........ 186.7 SEL/198.6 SPL \2\..... 736.2 26.2 876.9 394.0 28.7
--------------------------------------------------------------------------------------------------------------------------------------------------------
Socketed Pile Installation
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in steel permanent installation........ 166.2 SPL \3\............... 24.1 2.1 35.6 14.6 1.0
30-in steel temporary installation........ 166.2 SPL \3\............... 24.1 2.1 35.6 14.6 1.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
Rock Anchor Installation
--------------------------------------------------------------------------------------------------------------------------------------------------------
8-in anchor permanent installation (for 24- 166.2 SPL \3\............... 15.2 1.3 22.4 9.2 0.6
in piles).
33-in anchor permanent installation (for 166.2 SPL \3\............... 60.7 5.4 89.7 36.9 2.6
36-in piles).
33-in anchor permanent installation (for 166.2 SPL \3\............... 60.7 5.4 89.7 36.9 2.6
42-in piles).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The 24-in and 30-in-diameter source levels for vibratory driving are proxy from median measured source levels from pile driving of 30-in-diameter
piles to construct the Ketchikan Ferry Terminal (Denes et al. 2016, Table 72).
\2\ The 36-in and 42-in-diameter pile source levels are proxy from median measured source levels from pile driving (vibratory and impact hammering) of
48-in piles for the Port of Anchorage test pile project (Austin et al. 2016, Tables 9 and 16). We calculated the distances to impact pile driving
Level A harassment thresholds for 36-in piles assuming 100 strikes per pile and a maximum of 4 piles installed in 24 hours; for 42-in piles we assumed
135 strikes per pile and a maximum of 2 piles installed in 24 hours.
\3\ The socketing and rock anchoring source level is proxy from median measured sources levels from down-hole drilling of 24-in-diameter piles to
construct the Kodiak Ferry Terminal (Denes et al. 2016, Table 72).
Level B Harassment
Utilizing the practical spreading loss model, DPD determined
underwater noise will fall below the behavioral effects threshold of
120 dB rms for marine mammals at the distances shown in Table 8 for
vibratory pile driving/removal, socketing, and rock anchoring. With
these radial distances, and due to the occurrence of landforms (See
Figure 8, 12, 13 of IHA Application), the largest Level B Harassment
Zone calculated for vibratory pile driving for 36-in and 42-in steel
piles equaled 193 km\2\ and socket and rock anchoring equaled 116
km\2\. For calculating the Level B Harassment Zone for impact driving,
the practical spreading loss model was used with a behavioral threshold
of 160 dB rms. The maximum radial distance of the Level B Harassment
Zone for impact piling equaled 3,744 meters. At this radial distance,
the entire Level B Harassment Zone for impact piling equaled 19 km\2\.
Table 8 below provides all Level B Harassment radial distances
[[Page 18513]]
(m) and their corresponding areas (km\2\) during DPD's proposed
activities.
Table 8--Radial Distances (Meters) to Relevant Behavioral Isopleths and Associated Ensonified Areas (Square
Kilometers) Using the Practice Spreading Model
----------------------------------------------------------------------------------------------------------------
Level B
Activity Received level at 10 meters Level B harassment zone (m) harassment
* zone (km\2\)
----------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving/Removal
----------------------------------------------------------------------------------------------------------------
24-in steel installation............ 161.9 SPL \3\............... 6,215 (calculated 6,213).... 39 km\2\
30-in steel temporary installation.. 161.9 SPL \3\............... 6,215 (calculated 6,213).
30-in steel removal................. 161.9 SPL \3\............... 6,215 (calculated 6,213).
30-in steel permanent installation.. 161.9 SPL \3\............... 6,215 (calculated 6,213).
36-in steel permanent installation.. 168.2 SPL \4\............... 16,345 (calculated 16,343).. 193 km\2\
42-in steel permanent installation.. 168.2 SPL \4\............... 16,345 (calculated 16,343).
----------------------------------------------------------------------------------------------------------------
Impact Pile Driving 5 6
----------------------------------------------------------------------------------------------------------------
36-in steel permanent installation.. 186.7 SEL/198.6 SPL \4\..... 3,745 (calculated 3,744).... 19 km\2\
42-in steel permanent installation.. 186.7 SEL/198.6 SPL \4\..... 3,745 (calculated 3,744).
----------------------------------------------------------------------------------------------------------------
Socketed Pile Installation
----------------------------------------------------------------------------------------------------------------
24-in steel permanent installation.. 166.2 SPL \7\............... 12,025 (calculated 12,023).. 116 km\2\
30-in steel temporary installation.. 166.2 SPL \7\............... 12,025 (calculated 12,023).
----------------------------------------------------------------------------------------------------------------
Rock Anchor Installation
----------------------------------------------------------------------------------------------------------------
8-in anchor permanent installation 166.2 SPL \7\............... 12,025 (calculated 12,023).. 116 km\2\
(for 24-in piles).
33-in anchor permanent installation 166.2 SPL \7\............... 12,025 (calculated 12,023).
(for 36-in piles).
33-in anchor permanent installation 166.2 SPL \7\............... 12,025 (calculated 12,023)..
(for 42-in piles).
----------------------------------------------------------------------------------------------------------------
* Numbers rounded up to nearest 5 meters.
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. Potential exposures to impact pile driving, vibratory
pile driving/removal and socketing/rock anchoring noises for each
acoustic threshold were estimated using group size estimates and local
observational data. As previously stated, take by Level B harassment as
well as small numbers of take by Level A harassment will be will be
considered for this action. Take by Level B and Level A harassment are
calculated differently for some species based on monthly or daily
sightings data and average group sizes within the action area using the
best available data. Take by Level A harassment is being proposed for
three species where the Level A harassment isopleths are very large
during impact pile driving (harbor porpoise, harbor seal, and Steller
sea lion), and is based on average group size multiplied by the number
of days of impact pile driving. Distances to Level A harassment
thresholds for other project activities (vibratory pile driving/
removal, socketing, rock anchoring) are considerably smaller compared
to impact pile driving, and mitigation is expected to avoid Level A
harassment from these other activities.
Minke Whales
There are no density estimates of minke whales available in the
project area. These whales are usually sighted individually or in small
groups of 2-3, but there are reports of loose aggregations of hundreds
of animals (NMFS 2018). There was one sighting of a minke whale during
the 135 days of monitoring during the Huna Berth I construction project
(June 2015 through January 2016) (BergerABAM 2016). To be conservative,
we predict that three minke whales in a group could be sighted 3 times
over the 6-month project period for a total of 9 minke whales that are
proposed to be taken by Level B harassment.
Humpback Whales
There are no density estimates of humpback whales available in the
project area. Humpback whale presence in the action area is likely
steady through the work period until November, when most humpbacks
migrate back to Hawaii or Mexico. NMFS has received a few reports of
humpback whales over-wintering in Southeast Alaska, but numbers of
animals and exact locations are very hard to predict, and NMFS assumes
the presence of much fewer humpbacks in the action area in November and
later winter months. During the previous Huna Berth I project, humpback
whales were observed on 84 of the 135 days of monitoring; most often in
September and October (BergerABAM 2016). The best available information
on the distribution of humpbacks in the project area was obtained from
several sources including: Icy Strait observations from 2015
(BergerABAM 2016), Glacier Bay/Icy Strait NPS Survey data 2014-2018
(provided by NPS, March 2019), Whale Alert opportunistic reported
sightings 2016-2018, and reported HB whale bubble-net feeding group to
NPS, 2015-2018 (provided by NPS, March 2019).
The National Park Service Glacier Bay/Icy Strait survey is designed
to observe humpback whales and has regular effort in June, July, and
August. This is the primary data source used to estimate exposures of
humpback whales
[[Page 18514]]
in the action area during those months, except for when a maximum group
size reported in Whale Alert data was greater, then the Whale Alert
number was used (June and July maximum group size). The on-site marine
mammal monitoring data from BergerABAM (2016) was used to estimate
takes in September and October and Whale Alert data was the only data
source available in November and could represent a minimum number of
observations due to fewer opportunistic sightings recorded in that
month. In addition, a single group of bubble-net feeding humpbacks of
10 animals was added to the total estimated exposures for June and
October, based on anecdotal data provided by NPS of bubble-net feeding
groups of humpbacks in the action area in those months of construction.
To estimate the number of exposures, NMFS looked at the proportion
of days of the month when the numbers of animals observed were within
one standard deviation of that month's average daily sightings. That
proportion was 0.7. The average number of sightings was estimated as
exposures on those days. For the remaining 30 percent of work days, the
maximum number of observations on any single day were estimated to be
exposed on those days. For example, in June, the average number of
daily observations (1.31) was estimated to occur on 70 percent of the
17 work days, which resulted in 15.59 exposures. On the other 30
percent of the 17 work days, the maximum number of observations on any
day (10) resulted in 51 estimated exposures. In addition, in June, NMFS
estimates that one bubble-net feeding group of 10 individuals could be
exposed, due to anecdotal evidence of this feeding activity occurring
inside the proposed action area. NMFS estimates a total of 76.59
humpback whales could be exposed in June. Humpback whales could be in
larger groups when large amounts of prey are available, but this is
difficult to predict with any precision. Although we are not proposing
to authorize takes by month, we are demonstrating how the total take
was calculated. The total number of exposures per month was calculated
to be 76.59 (June), 68.02 (July), 71.93 (August), 132.07 (September),
78.82 (October), and 6.20 (November). The total proposed whales to be
taken by Level B harassment from June to November is 434 (433.63)
humpback whales with 27 of those whales anticipated being from the
Mexico DPS (0.0601 percentage of the total animals).
Gray Whales
There are no density estimates of gray whales available in the
project area. Gray whales travel alone or in small, unstable groups,
although large aggregations may be seen in feeding and breeding grounds
(NMFS 2018e). Observations in Glacier Bay and nearby waters recorded
two gray whales documented over a 10-year period (Keller et al., 2017).
None were observed during Huna Berth I project monitoring (BergerABAM
2016). We conservatively estimate a small group to be 3 gray whales x 1
sighting over the 6-month work period for a total of three gray whale
proposed to be taken by Level B harassment.
Killer Whales
There are no density estimates of killer whales available in the
project area. Killer whales occur commonly in the waters of the project
area, and could include members of several designated stocks that may
occur in the vicinity of the proposed project area. Whales are known to
use the Icy Strait corridor to enter and exit inland waters and are
observed in every month of the year, with certain pods being observed
inside Port Frederick passing directly in front of Hoonah. Group size
of resident killer whale pods in the Icy Strait area ranges from 42 to
79 and occur in every month of the year (Dahlheim pers. comm. to NMFS
2015). As determined during a line-transect survey by Dalheim et al.
(2008), the greatest number of transient killer whale observed occurred
in 1993 with 32 animals seen over two months for an average of 16
sightings per month. NMFS estimates that group size of 79 resident
killer whales and 16 transient killer whales could occur each month
during the 6-month project period for a total of 570 takes by Level B
harassment.
Pacific White-Sided Dolphin
There are no density estimates of Pacific white-sided dolphins
available in the project area. Pacific white-sided dolphins have been
observed in Alaska waters in groups ranging from 20 to 164 animals,
with the sighting of 164 animals occurring in Southeast Alaska near
Dixon Entrance (Muto et al., 2018). There were no Pacific white-sided
dolphins observed during the 135-day monitoring period during the Huna
Berth I project. However, to be conservative NMFS estimates 164 Pacific
white-sided dolphins may be seen once over the 6-month project period
for a total of 164 takes by Level B harassment.
Dall's Porpoise
Little information is available on the abundance of Dall's porpoise
in the inland waters of Southeast Alaska. Dall's porpoise are most
abundant in spring, observed with lower numbers in the summer, and
lowest numbers in fall. Jefferson et al., 2019 presents the first
abundance estimates for Dall's porpoise in these waters and found the
abundance in summer (N = 2,680, CV = 19.6 percent), and lowest in fall
(N = 1,637, CV = 23.3 percent). Dall's porpoise are common in Icy
Strait and sporadic with very low densities in Port Frederick
(Jefferson et al., 2019). Dahlheim et al. (2008) observed 346 Dall's
porpoise in Southeast Alaska (inclusive of Icy Strait) during the
summer (June/July) of 2007 for an average of 173 animals per month as
part of a 17-year study period. During the previous Huna Berth I
project, only two Dall's porpoise were observed, and were transiting
within the waters of Port Frederick in the vicinity of Halibut Island.
Therefore, NMFS' estimates 173 Dall's porpoise per month may be seen
each month of the 6-month project period for a total of 1,038 takes by
Level B harassment.
Harbor Porpoise
Dahlheim et al. (2015) observed 332 resident harbor porpoises occur
in the Icy Strait area, and harbor porpoise are known to use the Port
Frederick area as part of their core range. During the Huna Berth I
project monitoring, a total of 32 harbor porpoise were observed over 19
days during the 4-month project. The harbor porpoises were observed in
small groups with the largest group size reported was four individuals
and most group sizes consisting of three or fewer animals. NMFS
conservatively estimates that 332 harbor porpoises could occur in the
project area each month over the 6-month project period for a total of
1,932 takes by Level B harassment. Because the Level A harassment zone
is significantly larger than the shutdown zone during impact pile
driving, NMFS predicts that some take by Level A harassment may occur.
Based on the previous monitoring results, we estimate that a group size
of four harbor porpoises multiplied by 1 group per day over 8 days of
impact pile driving would yield a total of 32 takes by Level A
harassment.
Harbor Seal
There are no density estimates of harbor seals available in the
project area. Keller et al. (2017) observed an average of 26 harbor
seal sightings each month between June and August of 2014
[[Page 18515]]
in Glacier Bay and Icy Strait. During the monitoring of the Huna Berth
I project, harbor seals typically occur in groups of one to four
animals and a total of 63 seals were observed during 19 days of the
135-day monitoring period. NMFS conservatively estimate that 26 harbor
seals could occur in the project area each month during the 6-month
project period for a total of 156 takes by Level B harassment. Because
the Level A harassment zone is significantly larger than the shutdown
zone during impact pile driving, NMFS predicts that some take by Level
A harassment may occur. Based on the previous monitoring results, we
estimate that a group size of two harbor seals multiplied by 1 group
per day over 8 days of impact pile driving would yield a total of 16
takes by Level A harassment.
Steller Sea Lion
There are no density estimates of Steller sea lions available in
the project area. NMFS expects that Steller sea lion presence in the
action area will vary due to prey resources and the spatial
distribution of breeding versus non-breeding season. In April and May,
Steller sea lions are likely feeding on herring spawn in the action
area. Then, most Steller sea lions likely move to the rookeries along
the outside coast (away from the action area) during breeding season,
and would be in the action area in greater numbers in August and later
months (J. Womble, NPS, pers. comm. to NMFS AK Regional Office, March
2019). However, Steller sea lions are also opportunistic predators and
their presence can be hard to predict.
Steller sea lions typically occur in groups of 1-10 animals, but
may congregate in larger groups near rookeries and haulouts. The
previous Huna Berth I project observed a total of 180 Steller sea lion
sightings over 135 days in 2015, amounting to an average of 1.3
sightings per day (BergerABAM 2016). During a test pile program
performed at the project location by the Hoonah Cruise Ship Dock
Company in May 2018, a total of 15 Steller sea lions were seen over the
course of 7 hours in one day (SolsticeAK 2018).
We used the same process to calculate Steller sea lion take as
explained above or humpback whales, except that 79 percent of the work
days in each month are expected to expose the average number of
animals, and 21 percent of the work days would expose the maximum
number of animals. For example, in June, the average number of daily
observations (1.6) was estimated to occur on 13.43 work days, which
would result in 21.48 exposures. On the other 21 percent of the 17 work
days, the maximum number of observations on any day (26) could result
in 92.82 estimated exposures. NMFS estimates a total of 114.31 Steller
sea lions could be exposed in June. Although we are not proposing to
authorize takes by month, we are demonstrating how the total take was
calculated. The total number of exposures per month was calculated to
be 114.31 (June), 57.19 (July), 92.89 (August), 199.23 (September),
79.10 (October), and 16.57 (November). Therefore, the total proposed
Steller sea lions that may be taken by Level B harassment from June to
November is 559 Steller sea lions with 39 of those sea lions
anticipated being from the Western DPS (0.0702 percentage of the total
animals (L. Jemison draft unpublished Steller sea lion data, 2019).
Because the Level A harassment zone is significantly larger than the
shutdown zone during impact pile driving, NMFS predicts that some take
by Level A harassment may occur. Based on the previous monitoring
results, we estimate that a group size of two Steller sea lions
multiplied by 1 group per day over 8 days of impact pile driving would
yield a total of 16 takes by Level A harassment.
Table 9 below summarizes the proposed estimated take for all the
species described above as a percentage of stock abundance.
Table 9--Proposed Take Estimates as a Percentage of Stock Abundance
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Stock (NEST) Level A harassment Level B harassment Percent of stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Minke Whale....................... N/A....................... 0....................... 9....................... N/A
Humpback Whale.................... Hawaii DPS (9,487) \a\.... 406..................... 4.3
Mexico DPS (606) \a\...... 0....................... 27...................... 4.5
(Total 433).
Gray Whale........................ Eastern North Pacific 0....................... 3....................... Less than 1 percent
(26,960).
Killer Whale...................... Alaska Resident (2,347)... 469..................... 19.9 \b\
Northern Resident (261)... 0....................... 52...................... 19.9 \b\
West Coast Transient (243) 49...................... 20.2 \b\
(Total 570).
Pacific White-Sided Dolphin....... North Pacific (26,880).... 0....................... 164..................... Less than 1 percent
Dall's Porpoise................... Alaska (83,400) \c\....... 0....................... 1,038................... 1.2
Harbor Porpoise................... NA........................ 32...................... 1,932................... NA
Harbor Seal....................... Glacier Bay/Icy Strait 16...................... 156..................... 2.16
(7,210).
Steller Sea Lion.................. Eastern U.S. (41,638)..... 15...................... 520..................... 1.25 Less than 1 percent
Western U.S. (53,303)..... 1....................... 39
(Total 16).............. (Total 559).............
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Under the MMPA humpback whales are considered a single stock (Central North Pacific); however, we have divided them here to account for DPSs listed
under the ESA. Using the stock assessment from Muto et al. 2018 for the Central North Pacific stock (10,103 whales) and calculations in Wade et aal.
2016; 9,487 whales are expected to be from the Hawaii DPS and 606 from the Mexico DPS.
\b\ Take estimates are weighted based on calculated percentages of population for each distinct stock, assuming animals present would follow same
probability of presence in project area.
\c\ Jefferson et al. 2019 presents the first abundance estimates for Dall's porpoise in the waters of Southeast Alaska with highest abundance recorded
in spring (N = 5,381, CV = 25.4%), lower numbers in summer (N = 2,680, CV = 19.6%), and lowest in fall (N = 1,637, CV = 23.3%). However, NMFS
currently recognizes a single stock of Dall's porpoise in Alaskan waters and an estimate of 83,400 Dall's porpoises is used by NMFS for the entire
stock (Muto et al., 2018).
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
[[Page 18516]]
such species or stock for taking for certain subsistence uses (latter
not applicable for this action). NMFS regulations require applicants
for incidental take authorizations to include information about the
availability and feasibility (economic and technological) of equipment,
methods, and manner of conducting 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.
The following mitigation measures are proposed in the IHA:
Timing Restrictions
All work will be conducted during daylight hours. If poor
environmental conditions restrict visibility full visibility of the
shutdown zone, pile installation would be delayed.
Sound Attenuation
To minimize noise during impact pile driving, pile caps (pile
softening material) will be used. DPD 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.
Shutdown Zone for In-Water Heavy Machinery Work
For in-water heavy machinery work (using, e.g., movement of the
barge to the pile location; positioning of the pile on the substrate
via a crane (i.e., stabling the pile), removal of the pile from the
water column/substrate via a crane (i.e., deadpull); or placement of
sound attenuation devices around the piles.) If a marine mammal comes
within 10 m of such operations, operations shall cease and vessels
shall reduce speed to the minimum level required to maintain steerage
and safe working conditions.
Shutdown Zones
For all pile driving/removal and drilling activities, DPD will
establish a shutdown zone for a marine mammal species that is greater
than its corresponding Level A harassment zone; except for a few
circumstances during impact pile driving, over the course of 8 days,
where the shutdown zone is smaller than the Level A harassment zone for
high frequency cetaceans and phocids due to the practicability of
shutdowns on the applicant and to the potential difficulty of observing
these animals in the large Level A harassment zones. The calculated PTS
isopleths were rounded up to a whole number to determine the actual
shutdown zones that the applicant will operate under (Table 10). The
purpose of a shutdown zone is generally to define an area within which
shutdown of the activity would occur upon sighting of a marine mammal
(or in anticipation of an animal entering the defined area).
Table 10--Pile Driving Shutdown Zones During Project Activities
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Shutdown zones (radial distance in meters, area in km\2\)
Source ------------------------------------------------------------------------------------------------------------------------------------------------------------
Low-frequency cetaceans Mid-frequency cetaceans High-frequency cetaceans Phocids Otariids
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
In-Water Construction Activities
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Barge movements, pile positioning, 10 m (0.00093 km\2\).......... 10 m (0.00093 km\2\).......... 10 m (0.00093 km\2\)......... 10 m (0.00093 km\2\)......... 10 m (0.00093 km\2\)
sound attenuation placement *.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving/Removal
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
24-in steel installation (18 piles; 25 m (0.005763 km\2\)......... 10 m (0.00093 km\2\).......... 25 m (0.005763 km\2\)........ 10 m (0.00093 km\2\)......... 10 m (0.00093 km\2\)
~40 min per day on 4.5 days).
30-in steel temporary installation 25 m (0.005763 km\2\)......... 10 m (0.00093 km\2\).......... 25 m (0.005763 km\2\)........ 10 m (0.00093 km\2\)......... 10 m (0.00093 km\2\)
(62 piles; ~2 hours per day on
10.5 days).
30-in steel removal (62 piles; ~1 25 m (0.005763 km\2\)......... 10 m (0.00093 km\2\).......... 25 m (0.005763 km\2\)........ 10 m (0.00093 km\2\)......... 10 m (0.00093 km\2\)
hour per day on 10.5 days).
30-in steel permanent installation 25 m (0.005763 km\2\)......... 10 m (0.00093 km\2\).......... 25 m (0.005763 km\2\)........ 10 m (0.00093 km\2\)......... 10 m (0.00093 km\2\)
(3 piles; ~1 hour per day on 1.5
days).
36-in steel permanent installation 25 m (0.005763 km\2\)......... 10 m (0.00093 km\2\).......... 50 m (0.02307 km\2\)......... 25 m (0.005763 km\2\)........ 10 m (0.00093 km\2\)
(16 piles; ~1 hour per day on 8
days).
42-in steel permanent installation 50 m (0.02307 km\2\).......... 10 m (0.00093 km\2\).......... 50 m (0.02307 km\2\)......... 25 m (0.005763 km\2\)........ 10 m (0.00093 km\2\)
(8 piles; ~2 hours per day on 4
days).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Pile Driving
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
36-in steel permanent installation 1,000 m (2.31 km\2\).......... 50 m (0.02307 km\2\).......... 100 m* (0.0875 km\2\)........ 50 m* (0.02307 km\2\)........ 50 m (0.02307 km\2\)
(16 piles; ~10 minutes per day on
4 days).
42-in steel permanent installation 750 m (1.44 km\2\)............ 50 m (0.02307 km\2\).......... 100 m* (0.0875 km\2\)........ 50 m* (0.02307 km\2\)........ 50 m (0.02307 km\2\)
(8 piles; ~6 minutes per day on 4
days).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Socketed Pile Installation
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
24-in steel permanent installation 25 m (0.005763 km\2\)......... 10 m (0.00093 km\2\).......... 50 m (0.02307 km\2\)......... 15 m (0.0021 km\2\).......... 10 m (0.00093 km\2\)
(18 piles; ~2 hours per day on 9
days).
30-in steel temporary installation 25 m (0.005763 km\2\)......... 10 m (0.00093 km\2\).......... 50 m (0.02307 km\2\)......... 15 m (0.0021 km\2\).......... 10 m (0.00093 km\2\)
(up to 10 piles; ~2 hours per day
on 5 days).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 18517]]
Rock Anchor Installation
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
8-in anchor permanent installation 25 m (0.005763 km\2\)......... 10 m (0.00093 km\2\).......... 25 m (0.005763 km\2\)........ 10 m (0.00093 km\2\)......... 10 m (0.00093 km\2\)
(for 24-in piles, 2 anchors; ~1
hour per day on 2 days).
33-in anchor permanent installation 100 m (0.0875 km\2\).......... 10 m (0.00093 km\2\).......... 100 m (0.0875 km\2\)......... 50 m (0.02307 km\2\)......... 10 m (0.00093 km\2\)
(for 36- and 42-in piles, 24
anchors; ~8 hours per day on 12
days).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Due to practicability of the applicant to shutdown and the difficulty of observing some species and low occurrence of some species in the project area, such as high frequency cetaceans or
pinnipeds out to this distance, the shutdown zones were reduced and Level A harassment takes were requested.
Non-Authorized Take Prohibited
If a species enters or approaches the Level B zone and that species
is either not authorized for take or its authorized takes are met, pile
driving and removal activities must shut down immediately using delay
and shut-down procedures. Activities must not resume until the animal
has been confirmed to have left the area or an observation time period
of 15 minutes has elapsed for pinnipeds and small cetaceans and 30
minutes for large whales.
Soft Start
The use of a soft-start procedure 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 impact
hammer operating at full capacity. For impact pile driving, contractors
will be required to provide an initial set of three strikes from the
hammer at 40 percent energy, followed by a one-minute waiting period.
Then two subsequent three strike sets would occur. Soft Start is not
required during vibratory pile driving and removal activities.
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 of
effecting the least practicable impact on the affected species or
stocks and their habitat, paying particular attention to rookeries,
mating grounds, and areas of similar significance.
Proposed Monitoring and Reporting
In order to issue an IHA for an activity, Section 101(a)(5)(D) of
the MMPA states that NMFS must set forth, requirements pertaining to
the monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104 (a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present 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:
[ssquf] Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
[ssquf] 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);
[ssquf] Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
[ssquf] How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
[ssquf] Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
[ssquf] Mitigation and monitoring effectiveness.
DPD Briefings
DPD will conduct briefings between construction supervisors and
crews, marine mammal monitoring team, and DPD staff prior to the start
of all pile driving activities and when new personnel join the work, in
order to explain responsibilities, communication procedures, marine
mammal monitoring protocol, and operational procedures. The crew will
be requested to alert the PSO when a marine mammal is spotted in the
action area.
Protected Species Observer Check-In With Construction Crew
Each day prior to commencing pile driving activities, the lead NMFS
approved Protected Species Observer (PSO) will conduct a radio check
with the construction foreman or superintendent to confirm the
activities and zones to be monitored that day. The construction foreman
and lead PSO will maintain radio communications throughout the day so
that the PSOs may be alerted to any changes in the planned construction
activities and zones to be monitored.
Pre-Activity Monitoring
Prior to the start of daily in-water construction activity, or
whenever a break in pile driving of 30 min or longer occurs, PSOs will
observe the shutdown and monitoring zones for a period of 30 min. The
shutdown zone will be cleared when a marine mammal has not been
observed within the zone for that 30-min period. If a marine mammal is
observed within the shutdown zone, pile driving activities will not
begin until the animal has left the shutdown zone or has not been
observed for 15 min. If the Level B Harassment Monitoring Zone has been
observed for 30 min and no marine mammals (for which take has not been
authorized) are present within the zone, work can continue even if
visibility becomes impaired within the Monitoring Zone. When a marine
mammal permitted for Level B harassment take has been permitted is
present in the Monitoring zone, piling activities may begin and
[[Page 18518]]
Level B harassment take will be recorded.
Monitoring Zones
DPD will establish and observe monitoring zones for Level B
harassment as presented in Table 8. The monitoring zones for this
project are areas where SPLs are equal to or exceed 120 dB rms (for
vibratory pile driving/removal and socketing/rock anchoring) and 160 dB
rms (for impact pile driving). These zones provide utility for
monitoring conducted for mitigation purposes (i.e., shutdown zone
monitoring) by establishing monitoring protocols for areas adjacent to
the shutdown zones. Monitoring of the Level B harassment zones enables
observers to be aware of and communicate the presence of marine mammals
in the project area, but outside the shutdown zone, and thus prepare
for potential shutdowns of activity.
Visual Monitoring
Monitoring would be conducted 30 minutes before, during, and 30
minutes after all pile driving/removal and socking/rock anchoring
activities. In addition, PSO 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/removed or during socketing and rock anchoring. Pile
driving/removal and socketing/anchoring activities include the time to
install, remove, or socket/rock anchor a single pile or series of
piles, as long as the time elapsed between uses of the pile driving
equipment is no more than thirty minutes.
Monitoring will be conducted by PSOs from on land and from a
vessel. The number of PSOs will vary from three to four, depending on
the type of pile driving, method of pile driving and size of pile, all
of which determines the size of the harassment zones. Monitoring
locations will be selected to provide an unobstructed view of all water
within the shutdown zone and as much of the Level B harassment zone as
possible for pile driving activities. Three PSOs will monitor during
all impact pile driving activity at the lightering float project site.
Three PSOs will monitor during all impact pile driving activities at
the Berth II project site. Three PSOs will monitor during vibratory
pile driving of 24-in and 30-in steel piles. Four PSOs will monitor
during vibratory pile driving of 36-in and 42-in steel piles piles and
during all socketing/rock anchoring activities.
Three PSOs will monitor during all pile driving activities at the
lightering float project site, with locations as follows: PSO #1:
Stationed at or near the site of pile driving; PSO #2: Stationed on
Long Island (southwest of Hoonah in Port Frederick Inlet) and
positioned to be able to view west into Port Frederick Inlet and north
towards the project area; and PSO #3: Stationed on a vessel traveling a
circuitous route through the Level B monitoring zone.
Three PSOs will monitor during all impact pile driving activities
at the Berth II project site, with locations as follows: PSO #1:
Stationed at or near the site of pile driving; PSO #2: Stationed on
Halibut Island (northwest of the project site in Port Frederick Inlet)
and positioned to be able to view east towards Icy Strait and southeast
towards the project area; and PSO #3: Stationed on a vessel traveling a
circuitous route through the Level B monitoring zone.
Three PSOs will monitoring during vibratory pile driving of 24- and
30-in steel piles at the Berth II project site, with locations as
follows PSO #1: Stationed at or near the site of pile driving; PSO #2:
Stationed on Scraggy Island (northwest of the project site in Port
Frederick Inlet) an positioned to be able to view south towards the
project area; and PSO#3: Stationed on a vessel traveling a circuitous
route through the Level B monitoring zone.
Four PSOs will monitor during vibratory pile driving of 36-in and
42-in steel piles and during all socketing/rock anchoring activities
with locations as follows: PSO #1: Stationed at or near the site of
pile driving; PSO #2: Stationed on Hoonah Island (northwest of the
project site in Port Frederick Inlet) and positioned to be able to view
south towards the project site; PSO #3: Stationed across Icy Strait
north of the project site (on the mainland or the Porpoise Islands) and
positioned to be able to view west into Icy Strait and southwest
towards the project site; and PSO #4: Stationed on a vessel traveling a
circuitous route through the Level B monitoring zone.
In addition, 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-hour period (to reduce
PSO fatigue).
Monitoring of pile driving shall be conducted by qualified, NMFS-
approved PSOs, who shall have no other assigned tasks during monitoring
periods. DPD shall adhere to the following conditions when selecting
PSOs:
[ssquf] Independent PSOs shall be used (i.e., not construction
personnel);
[ssquf] At least one PSO must have prior experience working as a
marine mammal observer during construction activities;
[ssquf] Other PSOs may substitute education (degree in biological
science or related field) or training for experience;
[ssquf] Where a team of three or more PSOs are required, a lead
observer or monitoring coordinator shall be designated. The lead
observer must have prior experience working as a marine mammal observer
during construction;
[ssquf] DPD shall submit PSO CVs for approval by NMFS for all
observers prior to monitoring.
DPD shall ensure that the PSOs have the following additional
qualifications:
[ssquf] Visual acuity in both eyes (correction is permissible)
sufficient for discernment of moving targets at the water's surface
with ability to estimate target size and distance; use of binoculars
may be necessary to correctly identify the target;
[ssquf] Experience and ability to conduct field observations and
collect data according to assigned protocols;
[ssquf] Experience or training in the field identification of
marine mammals, including the identification of behaviors;
[ssquf] Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
[ssquf] 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;
[ssquf] 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; and
[ssquf] Sufficient training, orientation, or experience with the
construction operations to provide for personal safety during
observations.
Notification of Intent To Commence Construction
DPD shall inform NMFS OPR and the NMFS Alaska Region Protected
Resources Division one week prior to commencing construction
activities.
Interim Monthly Reports
During construction, DPD will submit brief, monthly reports to the
NMFS Alaska Region Protected Resources Division that summarize PSO
[[Page 18519]]
observations and recorded takes. Monthly reporting will allow NMFS to
track the amount of take (including extrapolated takes), to allow
reinitiation of consultation in a timely manner, if necessary. The
monthly reports will be submitted by email to a NMFS representative.
The reporting period for each monthly PSO report will be the entire
calendar month, and reports will be submitted by close of business on
the fifth day of the month following the end of the reporting period
(e.g., the monthly report covering September 1-30, 2019, would be
submitted to the NMFS by close of business on October 5, 2019).
Final Report
DPD shall submit a draft report to NMFS no later than 90 days
following the end of construction activities or 60 days prior to the
issuance of any subsequent IHA for the project. DPD shall provide a
final report within 30 days following resolution of NMFS' comments on
the draft report. Reports shall contain, at minimum, the following:
[ssquf] Date and time that monitored activity begins and ends for
each day conducted (monitoring period);
[ssquf] Construction activities occurring during each daily
observation period, including how many and what type of piles driven;
[ssquf] Deviation from initial proposal in pile numbers, pile
types, average driving times, etc.;
[ssquf] Weather parameters in each monitoring period (e.g., wind
speed, percent cloud cover, visibility);
[ssquf] Water conditions in each monitoring period (e.g., sea
state, tide state);
[ssquf] For each marine mammal sighting:
[cir] Species, numbers, and, if possible, sex and age class of
marine mammals;
[cir] Description of any observable marine mammal behavior
patterns, including bearing and direction of travel and distance from
pile driving activity;
[cir] Type of construction activity that was taking place at the
time of sighting;
[cir] Location and distance from pile driving activities to marine
mammals and distance from the marine mammals to the observation point;
[cir] If shutdown was implemented, behavioral reactions noted and
if they occurred before or after shutdown.
[cir] Estimated amount of time that the animals remained in the
Level A or B Harassment Zone.
[ssquf] Description of implementation of mitigation measures within
each monitoring period (e.g., shutdown or delay);
[ssquf] Other human activity in the area within each monitoring
period;
[ssquf] A summary of the following:
[cir] Total number of individuals of each species detected within
the Level B Harassment Zone, and estimated as taken if correction
factor appropriate.
[cir] Total number of individuals of each species detected within
the Level A Harassment Zone and the average amount of time that they
remained in that zone.
[cir] Daily average number of individuals of each species
(differentiated by month as appropriate) detected within the Level B
Harassment Zone, and estimated as taken, if appropriate.
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).
As stated in the proposed mitigation section, shutdown zones that
are larger than the Level A harassment zones will be implemented in the
majority of construction days, which, in combination with the fact that
the zones are so small to begin with, is expected avoid the likelihood
of Level A harassment for six of the nine species. For the other three
species (Steller sea lions, harbor seals, and harbor porpoises), a
small amount of Level A harassment has been conservatively proposed
because the Level A harassment zones are larger than the proposed
shutdown zones. However, given the nature of the activities and sound
source and the unlikelihood that animals would stay in the vicinity of
the pile-driving for long, any PTS incurred would be expected to be of
a low degree and unlikely to have any effects on individual fitness.
Exposures to elevated sound levels produced during pile driving
activities may cause behavioral responses by an animal, but they are
expected to be mild and temporary. 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; Lerma, 2014). Most likely, individuals
will simply move away from the sound source and be temporarily
displaced from the areas of pile driving, although even this reaction
has been observed primarily only in association with impact pile
driving. These reactions and behavioral changes are expected to subside
quickly when the exposures cease.
To minimize noise during pile driving, DPC will use pile caps (pile
softening material). 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.
During all impact driving, implementation of soft start procedures
and monitoring of established shutdown zones will be required,
significantly reducing the possibility of injury. Given sufficient
notice through use of soft start (for impact driving), marine mammals
are expected to move away from an irritating sound source prior to it
becoming potentially injurious. In addition, PSOs will be stationed
within the action area whenever pile driving/removal and socketing/rock
anchoring activities are underway. Depending on the activity, DDP will
employ the use of three to four PSOs to ensure all monitoring and
shutdown zones are properly observed. Although the expansion of Berth
facilities would have some permanent removal of habitat available to
marine mammals, the area
[[Page 18520]]
lost would be small, approximately equal to the area of the cruise ship
berth and associated pile placements. These impacts have been minimized
by use of a floating, pile-supported design rather than a design
requiring dredging or fill. The proposed design would not impede
migration of marine mammals through the proposed action area. The small
lightering facility nearer to the cannery would likely not impact any
marine mammal habitat since its proposed location is in between two
existing, heavily-traveled docks, and within an active marine
commercial and tourist area. There are no known pinniped haulouts or
other biologically important areas for marine mammals near the action
area.
In addition, impacts to marine mammal prey species are expected to
be minor and temporary. Overall, the area impacted by the project is
very small compared to the available habitat around Hoonah. The most
likely impact to prey will be temporary behavioral avoidance of the
immediate area. During pile driving/removal and socketing/rock
anchoring activities, it is expected that fish and marine mammals would
temporarily move to nearby locations and return to the area following
cessation of in-water construction activities. Therefore, indirect
effects on marine mammal prey during the construction are not expected
to be substantial.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
this activity are not expected to adversely affect the species or stock
through effects on annual rates of recruitment or survival:
[ssquf] No mortality is anticipated or authorized;
[ssquf] Minimal impacts to marine mammal habitat are expected;
[ssquf] The action area is located and within an active marine
commercial and tourist area;
[ssquf] There are no rookeries, or other known areas or features of
special significance for foraging or reproduction in the project area;
[ssquf] Anticipated incidents of Level B harassment consist of, at
worst, temporary modifications in behavior; and
[ssquf] The required mitigation measures (i.e. shutdown zones and
pile caps) are expected to be effective in reducing the effects of the
specified activity.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS preliminarily finds that the total marine
mammal take from the proposed activity will have a negligible impact on
all affected marine mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under Section 101(a)(5)(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.
Six of the nine marine mammal stocks proposed for take is less than
five percent of the stock abundance. For Alaska resident, northern
resident and transient killer whales, the number of proposed instances
of take as compared to the stock abundance are 19.9 percent, 19.9, and
20.2 percent, respectively. However, since three stocks of killer
whales could occur in the action area, the 570 total killer whale takes
are likely split among the three stocks. Nonetheless, since NMFS does
not have a good way to predict exactly how take will be split, NMFS
looked at the most conservative scenario, which is that all 570 takes
could potentially be distributed to each of the three stocks. This is a
highly unlikely scenario to occur and the percentages of each stock
taken are predicted to be significantly lower than values presented in
Table 9 for killer whales. Further, these percentages do not take into
consideration that some number of these take instances are likely
repeat takes incurred by the same individuals, thereby lowering the
number of individuals.
There are no official stock abundances for harbor porpoise and
minke whales; however, as discussed in greater detail in the
``Description of Marine Mammals in the Area of Specified Activities,''
we believe for the abundance information that is available, the
estimated takes are likely small percentages of the stock abundance.
For harbor porpoise, the abundance for the Southeast Alaska stock is
likely more represented by the aerial surveys that were conducted as
these surveys had better coverage and were corrected for observer bias.
Based on this data, the estimated take could potentially be
approximately 17 percent of the stock abundance. However, this is
unlikely and the percentage of the stock taken is likely lower as the
proposed take estimates are conservative and the project occurs in a
small footprint compared to the available habitat in Southeast Alaska.
For minke whales, in the northern part of their range they are believed
to be migratory and so few minke whales have been seen during three
offshore Gulf of Alaska surveys that a population estimate could not be
determined. With only nine proposed takes for this species, the
percentage of take in relation to the stock abundance is likely to be
very small.
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 September 2018, DPD contacted the Indigenous People's Council
for Marine Mammals (IPCoMM), the Alaska Sea Otter and Steller Sea Lion
Commission, and the Hoonah Indian Association (HIA) to determine
potential project impacts on local subsistence activities. No comments
were received from IPCoMM or the Alaska Sea Otter and Steller Sea Lion
Commission. On October 23, 2018, a conference call between
representatives from DPD, Turnagain Marine Construction, SolsticeAK,
and the HIA were held to discuss tribal concerns regarding subsistence
impacts. The tribe confirmed that Steller sea lions and harbor seals
are harvested in and around the project area. The HIA referenced the
2012 subsistence technical paper by Wolf et al. (2013) as the most
recent information available on marine mammal harvesting in Hoonah and
agreed that the proposed construction activities are unlikely to have
significant impacts to marine mammals as they are used in subsistence
applications. Information on the timing of the IHA issuance was
provided by DPD via email to the tribe on October 23, 2018. There have
been no further comments on this project.
Therefore, we believe there are no relevant subsistence uses of the
affected marine mammal stocks or species implicated by this action.
NMFS has preliminarily determined that the total taking of affected
species or stocks would not have an unmitigable adverse impact on the
availability of such
[[Page 18521]]
species or stocks for taking for subsistence purposes.
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 the Alaska Regional Office
(AKRO) whenever we propose to authorize take for endangered or
threatened species.
NMFS is proposing to authorize take of Mexico DPS humpback whales,
which are listed and Western DPS Steller sea lions under the ESA. The
Permit and Conservation Division 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 DPD's for conducting for the proposed pile driving and
removal activities for construction of the Hoonah Berth II cruise ship
terminal and lightering float, Icy Strait, Hoonah Alaska for one year,
beginning June 2019, provided the previously mentioned mitigation,
monitoring, and reporting requirements are incorporated. A draft of the
proposed IHA can be found at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.
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 pile
driving and removal activities for construction of the Hoonah Berth II
cruise ship terminal and lightering float. 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 one-year IHA renewal with
an expedited public comment period (15 days) 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 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:
[ssquf] A request for renewal is received no later than 60 days
prior to expiration of the current IHA.
[ssquf] The request for renewal must include the following:
(1) An explanation that the activities to be conducted under the
proposed Renewal are identical to the activities analyzed under the
initial IHA, are a subset of the activities, or include changes so
minor (e.g., reduction in pile size) that the changes do not affect the
previous analyses, mitigation and monitoring requirements, or take
estimates (with the exception of reducing the type or amount of take
because only a subset of the initially analyzed activities remain to be
completed under the Renewal); 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.
[ssquf] Upon review of the request for renewal, the status of the
affected species or stocks, and any other pertinent information, NMFS
determines that there are no more than minor changes in the activities,
the mitigation and monitoring measures will remain the same and
appropriate, and the findings in the initial IHA remain valid.
Dated: April 26, 2019.
Catherine G. Marzin,
Deputy Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2019-08848 Filed 4-30-19; 8:45 am]
BILLING CODE 3510-22-P
