Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Construction of the Port of Alaska's Petroleum and Cement Terminal, Anchorage, Alaska, 72154-72184 [2019-28102]
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Federal Register / Vol. 84, No. 249 / Monday, December 30, 2019 / Notices
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric
Administration
[RTID 0648–XR027]
Takes of Marine Mammals Incidental to
Specified Activities; Taking Marine
Mammals Incidental to Construction of
the Port of Alaska’s Petroleum and
Cement Terminal, Anchorage, Alaska
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.
AGENCY:
NMFS has received a request
from the Port of Alaska (POA) for
authorization to take marine mammals
incidental to pile driving associated
with the construction of a new
Petroleum and Cement Terminal (PCT)
in Knik Arm, Alaska. Pursuant to the
Marine Mammal Protection Act
(MMPA), NMFS is requesting comments
on its proposal to issue two successive
incidental harassment authorizations
(IHAs) to incidentally take marine
mammals during the specified activities.
NMFS is also requesting comments on
possible one-year renewals 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 January 29,
2020.
SUMMARY:
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 EastWest Highway, Silver Spring, MD 20910
and electronic comments should be sent
to ITP.Daly@noaa.gov.
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 25megabyte file size. Attachments to
electronic comments will be accepted in
Microsoft Word or Excel or Adobe PDF
file formats only. All comments
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ADDRESSES:
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received are a part of the public record
and will generally be posted online at
https://www.fisheries.noaa.gov/permit/
incidental-take-authorizations-undermarine-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:
Jaclyn Daly, 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-undermarine-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. Under
the MMPA, ‘‘take’’ is defined as
meaning to harass, hunt, capture, or kill,
or attempt to harass, hunt, capture, or
kill any marine mammal.
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
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and reporting of such takings are set
forth. The definitions of all applicable
MMPA statutory terms cited above are
included in the relevant sections below.
National Environmental Policy Act
To comply with the National
Environmental Policy Act of 1969
(NEPA; 42 U.S.C. 4321 et seq.) and
NOAA Administrative Order (NAO)
216–6A, NMFS must review our
proposed action (i.e., the issuance of an
incidental harassment authorization)
with respect to potential impacts on the
human environment.
Accordingly, NMFS is preparing an
Environmental Assessment (EA) to
consider the environmental impacts
associated with the issuance of the
proposed IHA. NMFS’ EA will be made
available at https://
www.fisheries.noaa.gov/permit/
incidental-take-authorizations-undermarine-mammal-protection-act. We will
review all comments submitted in
response to this notice prior to
concluding our NEPA process or making
a final decision on the IHA request.
Summary of Request
On November 28, 2018, NMFS
received a request from the POA for an
IHA to take marine mammals incidental
to pile driving associated with the
construction of the PCT. On June 19,
2019, the POA submitted a subsequent,
after request realizing the project would
take two construction seasons (April–
November) to complete. Because of this
modified construction schedule, the
POA submitted a new application on
July 19, 2019 and a revised application
on August 9, 2019. Although NMFS
disagreed with some of the analysis in
the application (as described later in
this document), we deemed it adequate
and complete on August 28, 2019,
because it contained all the information
necessary for us to conduct our MMPA
analysis. The POA submitted a
subsequent revised application on
October 15, 2019, which is available at
https://www.fisheries.noaa.gov/permit/
incidental-take-authorizations-undermarine-mammal-protection-act. The
POA’s request is for take of small
numbers of six species of marine
mammals, by Level B harassment. Four
of the species could also be taken by
Level A harassment. Neither the POA
nor NMFS expects serious injury or
mortality to result from this activity;
therefore, an IHA is appropriate.
NMFS previously issued IHAs and
Letters of Authorization (LOAs) to the
POA for pile driving (73 FR 41318, July
18, 2008; 74 FR 35136, July 20, 2009;
and 81 FR 15048; March 21, 2016). The
POA complied with all the requirements
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(e.g., mitigation, monitoring, and
reporting) of all previous incidental take
authorizations and did not exceed
authorized take. Information regarding
their monitoring results may be found in
the Effects of the Specified Activity on
Marine Mammals and their Habitat and
Estimated Take sections.
Description of Proposed Activity
Overview
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The POA proposes to construct a new
PCT comprised of a pile-supported
structure located along the
southernmost shoreline of the POA (see
Figure 1–1 and Figure 1–2 in the POA’s
IHA application), as part of its Port of
Alaska Modernization Project (PAMP).
In general, the PAMP will include
construction of new pile-supported
wharves and trestles south and west of
the existing terminals, with a planned
design life of 75 years. The proposed
project, the PCT project, is one
component of the PAMP.
The PCT project will replace the
existing Petroleum Oil Lubricants
Terminal which is currently the only
bulk cement-handling facility in Alaska
and is the primary terminal for receipt
of refined petroleum products. The PCT
Project will involve new construction of
a loading platform, access trestle, and
dolphins; and installation of utilities
(electricity, water, and communication),
petroleum, and cement lines linking the
terminal and shore. Ships mooring to
the PCT will utilize both breasting
dolphins and mooring dolphins. The
PCT will be designed to satisfy projectspecific seismic performance criteria,
allowing the terminal to be quickly
restored to service following a major
seismic event such as the magnitude 7.0
earthquake that struck Anchorage on
November 30, 2018.
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The POA will install three breasting
dolphins and six mooring dolphins as
well as a new loading platform and
catwalks. In addition to these
permanent structures, temporary access
trestles will be installed and
subsequently removed. Pile installation
will occur in water depths that range
from a few feet or dry conditions nearest
the shore to approximately 80 feet at the
outer face of the loading platform,
depending on tidal stage. Various work
boats and barges will be utilized to
support construction. Work will be
completed over two construction
seasons (April through November):
Phase 1 will occur in 2020 and Phase 2
will occur in 2021.
Dates and Duration
POA anticipates two construction
seasons (April–November) will be
required to complete the PCT terminal.
The POA has requested two IHAs to
cover this work. These IHAs correspond
with Phase 1 and Phase 2. The POA
anticipates 359 hours of pile driving and
removal over 127 days in Phase 1 and
229 hours of pile driving and removal
over 75 days in Phase 2. For each phase,
construction mobilization is planned to
commence the first week of April, with
the potential to initiate pile installation
activities by mid-April. Construction
demobilization is planned to occur in
November, with the expectation to
remove the final temporary piles by the
first week of November. Between April
and November, piles will be installed
and removed during daylight hours
only.
Specific Geographic Region
Cook Inlet is a large tidal estuary that
exchanges waters at its mouth with the
Gulf of Alaska. The inlet is roughly
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20,000 square kilometers (km2; 7,700
square miles [mi2]) in area, with
approximately 1,350 linear kilometers
(840 miles) of coastline (Rugh et al.
2000) and an average depth of
approximately 100 meters (330 feet).
Cook Inlet is generally divided into
upper and lower regions by the East and
West Forelands. Northern Cook Inlet
bifurcates into Knik Arm to the north
and Turnagain Arm to the east. The
POA is located in the southeastern
shoreline of Knik Arm (Figure 1).
Knik Arm is generally considered to
begin at Point Woronzof, 7.4 kilometers
(4.6 miles) southwest of the POA. From
Point Woronzof, Knik Arm extends
about 48 kilometers (30 miles) in a
north-northeasterly direction to the
mouths of the Matanuska and Knik
rivers. At Cairn Point, just northeast of
the POA, Knik Arm narrows to about 2.4
kilometers (1.5 miles) before widening
to as much as 8 kilometers (5 miles) at
the tidal flats northwest of Eagle Bay at
the mouth of Eagle River, which are
heavily utilized by Cook Inlet beluga
whales (CIBWs). Approximately 60
percent of Knik Arm is exposed at mean
lower low water (MLLW). The intertidal
(tidally influenced) areas of Knik Arm,
including those at the POA, are
mudflats, both vegetated and
unvegetated, which consist primarily of
fine, silt-sized glacial flour.
The POA’s boundaries currently
occupy an area of approximately 129
acres. Other commercial and industrial
activities related to secure maritime
operations are located near the POA on
Alaska Railroad Corporation (ARRC)
property immediately south of the POA,
on approximately 111 acres.
BILLING CODE 3510–22–C
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BILLING CODE 3510–22–P
Detailed Description of Specific Activity
Located within the Municipality of
Anchorage on Knik Arm in upper Cook
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Inlet (see Figure 1–1 in the POA’s IHA
application), the POA’s existing
infrastructure and support facilities
were constructed largely in the 1960s.
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Port facilities are substantially past their
design life, have degraded to levels of
marginal safety, and are in many cases
functionally obsolete, especially in
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regard to seismic design criteria and
condition.
The purpose for the PCT Project is to
replace the existing Petroleum Oil
Lubricants Terminal (POL 1), the only
bulk cement-handling facility in Alaska
and the primary terminal for receipt of
refined petroleum products. POL 1,
built in 1965, is more than 50 years old
and consists of 160 wharf pilings that
are uncoated, hollow-steel pile. The
need for the PCT is based on the heavily
deteriorated physical condition of POL
1. It suffers from severe corrosion of its
foundation pilings to levels of marginal
safety, as evidenced by currently
imposed load restrictions. A 2014 pile
condition assessment found severe
corrosion throughout the facility, with
pile wall losses exceeding 67 percent of
their original thickness. It also sustained
structural damage from a magnitude 7.1
earthquake that struck the area on
November 30, 2018. Recent inspections
in 2019 have led engineers to confirm
that the stress imposed on the alreadyweakened structure by the November 30
quake caused some piling failure and
predisposes the docks to additional
failure during future earthquakes. The
PCT has been designed to satisfy
project-specific seismic performance
criteria, allowing the terminal to be
quickly restored to service following a
major seismic event. POL 1 is
functionally obsolete, has exceeded its
useful life, and is unlikely to withstand
another such earthquake.
The PCT Project includes three major
components: (1) A loading platform in
Phase 1, (2) an access trestle (bridge-like
structure allowing access to the loading
platform) in Phase 1, and (3) breasting
and mooring dolphins in Phase 2 (see
Table 1–1). A temporary work trestle
and temporary templates are required
for constructing the permanent access
trestle in Phase 1, and temporary
templates are required for constructing
the dolphins in Phase 2. During both
Phase 1 and Phase 2, temporary mooring
dolphins will be required to
accommodate construction barges and
to moor construction vessels. Piles will
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be installed primarily with an impact
hammer; however, some vibratory pile
driving is also required. A bubble
curtain will be deployed to reduce inwater sound levels during PCT
construction for impact and vibratory
hammer pile installation of 144-, 48-,
36-, and 24-inch plumb (vertical) piles
and vibratory hammer removal of 36and 24-inch plumb piles (all temporary
and permanent piles). A bubble curtain
will not be deployed during installation
and removal of 24-inch battered
(installed at an angle, not vertical) piles
for the temporary construction work
trestle and temporary dolphins due to
the difficult geometric application.
All Phase 1 work will occur under the
first IHA, while Phase 2 work will occur
under the second IHA. Pile sizes and
quantities for permanent and temporary
components for each phase are shown
in Table 1–1; estimates of the time
required to install or remove piles for
each phase are shown in Table 1–2.
TABLE 1–1—SUMMARY OF PCT PROJECT COMPONENTS AND ACTIVITIES
Type of activity
Location
Phase
Size and type
Total amount or number
Permanent Components
Permanent pile installation (loading platform) ..............
Permanent pile installation (access trestle) ..................
Permanent pile installation (breasting and mooring
dolphins).
Installation of concrete decking on loading platform
and main trestle.
Catwalks ........................................................................
In water ............
In water ............
In water ............
1
1
2
48-inch steel pipe (plumb)
48-inch steel pipe (plumb)
144-inch steel pipe (plumb)
45 piles.
26 piles.
9 piles.
Above water .....
1
Pre-cast panels .................
About 120 panels.
Above water .....
2
Prefabricated steel or aluminum trusses with open
steel grating.
9 units, totaling 990 feet.
Construction Support and Temporary Components
Vessel support ..............................................................
In water ............
1&2
Barges and tugs ................
Temporary pile installation (construction work trestle)
In-water ............
1
1
Temporary
Temporary
Temporary
Temporary
In-water
In-water
In-water
In-water
24-inch steel pipe (plumb)
24-inch steel pipe (battered).
36-inch steel pipe (plumb)
36-inch steel pipe (plumb)
24-inch steel pipe (plumb)
20,000 pound Danforth anchors.
36-inch steel pipe (plumb)
24-inch steel pipe (plumb)
4-inch steel pipe (battered)
pile installation (dolphin templates) ............
pile installation (construction work trestle)
pile installation (access trestle templates)
mooring anchor systems ............................
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Temporary derrick barge ...............................................
Temporary dolphins for mooring construction vessels
............
............
............
............
2
1
1
1&2
In-water ............
In-water ............
1&2
1&2
16 flat deck barges, 2 derrick barges, and 3–4
tugs.
26 piles
10 piles.
72 piles.
26 piles.
36 piles.
2 mooring systems.
4 piles.
3 dolphins, each with 1
plumb and 2 battered
piles (9 piles total).
Installation of Utility, Petroleum, and Cement Lines
Installation on access trestle and loading platform ......
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Above water,
on-dock.
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1
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Pipelines, various sizes
and types.
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300–600 linear feet each.
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TABLE 1–2—PCT CONSTRUCTION PILE DETAILS AND ESTIMATED EFFORT REQUIRED FOR PILE INSTALLATION AND
REMOVAL
Average
embedded
depth
(feet)
Total
number
of piles
Pipe pile
diameter
Feature a
Number
of piles
48-inch .......
Loading Platform .......
45
Access Trestle ..........
26
Temporary Construction Work Trestle.
Temporary Derrick
Barge.
Temporary Construction Work Trestle.
Temporary Construction Work Trestle,
Battered.
Temporary Construction Access Trestle
Template.
Temporary Dolphins
for mooring construction vessels.
Temporary Dolphins
for mooring construction vessels,
Battered.
26
Vibratory
duration per
pile
(minutes)
Estimated
total
number
of hours
Production
rate piles
per day
(range)
2,300 (50 restrikes
each for 4 piles).
3,000 (50 restrikes
each for 3 piles).
50 restrikes for 10
piles.
NA .............................
73
1.5
30.
56
(1–3)
17.
33
3
(2–4)
4
65
25
3
(2–4)
1.6
(1–2)
9
9
1
1
9
9
6
6
12 installation.
12 removal.
Impact strikes per pile
Days of installation
and removal
Phase 1
36-inch .......
24-inch .......
71
100
30
130
30
115
75
40
75
140
75
10
105
75
50 restrikes of 10
piles.
NA .............................
36
105
75
NA .............................
90
3
(2–4)
3
50
30
NA .............................
3
3
1 installation.
1 removal.
6
50
30
NA .............................
9
3
2 installation.
2 removal.
..................
....................
...................................
359
..................
4
26
81
Phase 1 Construction Totals .................................
182 piles
5
installation.
removal.
installation.
removal.
installation
removal.
installation.
removal.
127.
Phase 2
24-inch .......
36-inch .......
144-inch .....
Temporary Dolphins
for mooring construction vessels.
Temporary Dolphins
for mooring construction vessels,
Battered.
Temporary Construction Dolphin Template.
Temporary derrick
barge.
Mooring Dolphin ........
3
9
6
72
76
4
6
Breasting Dolphin ......
9
3
50
30
NA .............................
3
3
1 installation.
1 removal.
50
30
NA .............................
9
3
2 installation.
2 removal.
115
75
NA .............................
180
3 (2–4)
40
75
NA .............................
5
4
140
45 ( 1 pile)
5,000 (1,500 first day,
3,500 second day).
21
0.5
11
(0.3 or 0.7)
6.
229
..................
75.
135
Phase 2 Construction Totals .................................
94 piles
The estimated source levels for each
pile type and installation method are
provided in Table 2. These source levels
..................
....................
...................................
are from the acoustic monitoring during
the POA’s 2016 Test Pile Program (TPP)
(for 48-in piles) and investigation of
24 installation.
24 removal.
1 installation.
1 removal.
13.
existing literature at other locations for
non-48-in piles.
TABLE 2—ESTIMATED PILE SOURCE LEVELS WITH AND WITHOUT BUBBLE CURTAINS
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Method and pile
size
Sound level at 10 m
Data source
Vibratory
Unattenuated
db rms
Bubble curtain
7 dB reduction, dB rms
144-in ....................
48-in ......................
36-in ......................
24-in ......................
178
168
166
161
171
161
159
154
Unattenuated
Bubble curtain
Caltrans 2015.
Austin et al 2016.
Navy 2015.
Navy 2015.
Impact
dB rms
144-in ....................
48-in ......................
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200
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198
187
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220
215
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202
193
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191
180
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208
Caltrans 2015.
Austin et al. 2016.
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Unattenuated
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Bubble curtain
Impact
dB rms
36-in ......................
24-in ......................
dB SEL
194
193
184
181
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Phase 1—Loading Platform and Access
Trestle Construction Description
Phase 1 will take place during 2020
and will include construction of the
loading platform and access trestle.
Construction will be accomplished from
two concurrent headings or directions;
one marine-side derrick barge with a
crane/hammer will be used to construct
the loading platform, and a land-side
crawler crane/hammer will be used to
construct the temporary and permanent
access trestle from the shoreline out.
The crawler crane will initially advance
the temporary work trestle out from the
shoreline with a top-down or leap-frog
type construction method, and then the
crawler crane will work off of the
temporary work trestle to construct the
permanent trestle all the way out to the
loading platform.
For the loading platform, which is
supported with 48-inch piles, the
contractor will first mobilize the
marine-based derrick barge on the
seaward side of the platform location
and install four temporary mooring piles
to stabilize the derrick barge during the
construction season. Also, three
temporary mooring dolphins will be
constructed in the vicinity of the PCT to
serve as mooring for construction
vessels and barges containing
construction materials, and will be
removed at the end of the construction
season. The derrick barge will host the
crane and hammer used to install the
permanent loading platform piles and
decking. Each of the platform piles will
be installed using an impact hammer
with a bubble curtain applied. A
vibratory hammer would only be used
in the infrequent event that an
obstruction were encountered while
driving the pile that requires removal or
repositioning of the pile with a vibratory
hammer.
Four of the permanent platform piles
will be ‘‘proofed’’ to confirm their
ability to withstand design loads.
Proofing involves approximately 50
impact hammer restrikes over an
approximate 10-minute period while
instrumentation is attached to the pile
during restrike to confirm design
conformance. Pile cleanout activities, to
prepare the interior of the hollow pile
for partial concrete filling, will occur
only in the top portion of the pile, but
not below mudline. Any material
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211
210
dB SEL
187
186
adhered to the top inside of the pile will
be removed to prepare for concrete
installation, and a soffit form will be
inserted into the hollow pile to prevent
the closure pour concrete from reaching
mudline. Formwork will be constructed
around the top of the pile, out of the
water, to support placement of a precast
concrete cap on top of each pile. The
closure pour, where concrete is poured
into the pile above the soffit form,
connects the pile to the precast pile
caps, bonding the pile to the cap.
Precast platform panels are then placed
on the deck, and additional concrete
will be poured on top of the panels to
create the platform decking.
For the access trestle, the permanent
access trestle construction requires
construction of a parallel temporary
trestle, installed adjacent to the
permanent trestle, from which to
advance the temporary piles used for
templates and installation of the
permanent access trestle piles. While
the permanent trestle requires 48-inch
piles, the temporary trestle will be
constructed using 24- and 36-inch piles.
Initial construction of the temporary
work trestle will be advanced first; then,
as the work trestle advances water-ward
and room is made available to
accommodate construction equipment,
work will commence on construction of
the permanent access trestle
coincidentally as the temporary work
trestle is advanced water-ward toward
the loading platform.
Construction of the trestles will occur
concurrently with construction of the
loading platform. A crawler crane will
be used to install piles for the temporary
trestle, building seaward from the shore
using a top-down or leap-frog
construction method. The crawler crane
will advance onto the temporary trestle
to complete pile installation and
decking for the temporary trestle. Once
the first section of temporary trestle is
constructed and the crawler crane is
advanced, a second crawler crane will
advance onto the deck of the temporary
trestle and be used to install the first
section of template and permanent piles
for the permanent access trestle (see Pile
Driving Scenarios, below).
Three of the permanent trestle piles
will be ‘‘proofed’’ to confirm their
ability to withstand design loads. In
addition, it is estimated that 10 each of
the 24- and 36-inch temporary work
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dB peak
177
174
204
203
Navy 2015.
Navy 2015.
trestle piles may need to be proofed to
confirm load capacities for construction
equipment. Template piles will stay in
place until precast pile caps are placed
on the permanent trestle piles following
installation. The temporary trestle will
stay in place for the entire construction
season, and will be used as a work
platform for decking installation on the
permanent trestle. The temporary trestle
decking and piles will be removed at the
end of construction activities for Phase
1. Removal is expected to require the
same amount of time as installation due
to the strong pile setup and resistance
conditions related to Knik Arm
sediments.
The permanent access trestle is
comprised of eight bents (clusters) of
three piles each and one bent of two
piles at the abutment. The abutment
bent (two piles) is located above mean
high water on shore and will be
installed in the dry. The next three
bents are located in the intertidal zone
and therefore may or may not be
installed in water depending upon the
tidal stage (i.e., if the tide is high, they
may be in water, but if the tide is low,
they will not be in water). The parallel
temporary construction trestle will
follow the same pattern. For purposes of
this analysis, it is assumed that all piles
will be driven in water; however, if
piles are driven in the dry during actual
construction, takes of marine mammals
will be assumed not to occur. Also,
some of the permanent trestle piles may
be started/partially driven with a
vibratory hammer when in the dry at the
abutment (two piles) and the first three
bents (three piles each) in order to set
the pile up for impact hammer
installation; this condition also is not
expected to generate takes. This is a
unique situation at this location due to
the highly variable tidal conditions and
the need to provide initial pile support
for impact hammer installation.
To construct the loading platform and
permanent access trestle, piles will be
installed using an impact hammer to
drive through the overburden sediment
layer and into the bearing layer, to an
average embedded depth of about 100
feet (loading platform piles) and 130 feet
(access trestle piles) below the substrate.
Installation and removal of all
temporary piles, including derrick barge
mooring piles, mooring dolphin piles
for mooring construction vessels,
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temporary access trestle piles, and
templates for installation of the
permanent access trestle piles, will use
vibratory hammer methods. Limited
vibratory hammer application may be
required for loading platform and
permanent trestle piles due to safety
reasons, constructability, or if a pile
encounters an obstruction.
Phase 2—Mooring and Breasting
Dolphins Construction Description
Phase 2 will occur in 2021 and will
include construction of the mooring and
breasting dolphins. Construction will be
accomplished from one marine-based
derrick barge with a crane/hammer
work station. Similar to Phase 1, the
contractor will initially install four
temporary mooring piles to stabilize the
derrick barge during the construction
season. Also, three temporary mooring
dolphins will be constructed in the
vicinity of the PCT to serve as mooring
for construction vessels and barges
containing construction materials, and
will be removed at the end of the
construction season. The derrick barge
will host the crane and hammer used to
install the mooring and breasting
dolphins. Temporary template piles will
then be installed to anchor the template
that will guide the installation of the
permanent dolphin piles at each of the
dolphin locations. Template piles will
be installed approximately 115 feet into
the substrate. Temporary template piles
will be driven in a grid formation
surrounding the location of each
dolphin pile, with a steel framework
bolted to the temporary piles to guide
dolphin pile installation. The
framework includes adjustable
components and hydraulic guides that
can be adjusted to maintain correct
positioning of the dolphins once they
are in place. All template piles will be
aligned plumb (vertically) and installed
and removed using a vibratory hammer
due to accuracy requirements for setting
the template. All plumb piles will
employ a bubble curtain during all piledriving activity.
Ships mooring to the PCT will utilize
both breasting dolphins and mooring
dolphins. To meet required structural
demands, monopile dolphins are
planned for both the breasting and
mooring dolphins. Breasting dolphins
are designed to assist in the berthing of
vessels by absorbing some of the lateral
load during vessel impact. Breasting
dolphins also protect the loading
platform from impacts by vessels.
Mooring dolphins, as their name
implies, are used for mooring only and
provide a place for a vessel to be
secured by lines (ropes). Use of mooring
dolphins helps control transverse and
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longitudinal movements of berthed
vessels.
In total, nine 144-in mooring and
breasting dolphins will be installed at
the PCT. Six mooring dolphins will be
constructed parallel to and landward of
the loading platform face and three
breasting dolphins will be installed in
alignment with the loading platform
(Figure 1–2 in the POA’s IHA
application). These dolphins will
provide for secure ship docking at the
terminal. Each mooring and breasting
dolphin will be comprised of a single
round 144-inch steel pipe pile or
monopile, driven to an average
embedded depth of about 140 feet below
the substrate.
Following temporary pile installation
with a vibratory hammer of the dolphin
template, held in place with 36-inch
piles, the crane will loft the first
permanent pile length (approximately
100 feet) and ready it for lowering
through the template framework. The
crane will have a boom holding the top
of the pile as well as a spotter arm lower
on the pile to steady the pile for
positioning. The pile will then be
lowered through the template and
readied for pile driving. Impact pile
driving will be used to advance the pile
to a prescribed depth, at which point
pile-driving activity will stop to allow
field splicing of the second pile length.
Decking will be added to the temporary
pile template framework to
accommodate welders; no pile driving
will be conducted during the welding
and testing of the two lengths of pile, as
the crane will be holding the second
pile length in place. Once the first and
second lengths of pile are spliced, pile
driving will be reinitiated until the tip
is at the prescribed depth. Limited
vibratory hammer application may be
required on the mooring or breasting
dolphin piles for safety reasons or if a
pile encounters an obstruction.
Following monopile installation, the
superstructure will be installed atop the
monopile. A precast concrete mooring
cap will be added to the monopile. The
caps will be welded to the piles by an
embedded steel ring in the precast cap.
This activity will not require in-water
work or hammer activity. The three
breasting dolphins will have fenders
installed, which will be attached to the
mooring cap and will not require inwater or hammer work.
Once the first and second lengths of
pile, ring and mooring cap, and fender,
if applicable, are assembled at the first
location, the temporary pile template
will be removed using a vibratory
hammer. The barge will be repositioned
to the next location, and the work
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activity will commence as described
above.
One crane will be used for installation
of dolphin piles and associated
temporary template piles; multiple
hammers will not be employed
simultaneously. Templates will be reused at each dolphin location. The
crane will alternate between installing
template piles, driving dolphin piles,
removing template piles, and out-ofwater work such as placement of
decking, catwalks, and utility racks
along the platform and trestle. All
terminal utility work is out of the water,
and includes installation of pipe racks
and utilities along the platform and
trestle.
Phases 1 and 2—Temporary Mooring
Dolphins
Three temporary mooring dolphins
will be installed near the PCT during
Phases 1 and 2. Working barges and
construction vessels associated with the
PCT Project will use the temporary
mooring dolphins during PCT
construction. Each temporary mooring
dolphin will consist of one 24-inch
plumb pile and two 24-inch battered
piles installed with a vibratory hammer
(nine piles total).
Pile-Driving Summary—Phases 1 and 2
Pile installation will occur in water
depths that range from a few feet or dry
conditions (at low tide) nearest the
shore to approximately 24 meters (80
feet) at the outer face of the loading
platform at high tide, depending on
tidal stage (see Figure 1–3 and Figure 1–
4 in the POA’s IHA application). Figure
1–3 in the POA’s IHA application shows
three test piles that were installed in
2016 and are located just water-ward of
the face of the PCT loading platform
(test piles were removed in 2019). The
PCT will be constructed between these
three test piles and the shore; for
illustrative purposes, the distance from
the water-ward edge of the PCT loading
platform (general location of test piles)
is approximately 30 meters from mean
lower low water and 115 meters from
mean higher high water.
The pile-driving construction season
for Phase 1 is scheduled to commence
April 15, 2020, and end the first week
of November 2020 (November 7 for
purposes of this analysis), with
decommissioning occurring during the
remainder of November.
Decommissioning will not require inwater pile driving. Construction days
when piles are not being installed or
removed will be devoted to other work
such as welding or deck work. The POA
is working with their contractor to
schedule deck work and other non-pile-
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driving work to the maximum extent
practicable during the August/
September timeframe when beluga
whale abundance is higher in Knik Arm.
Similarly, the pile driving construction
season for Phase 2 is planned to
commence in May 2021 and end in
early November 2021. The estimated
duration for installation and removal of
PCT permanent and temporary piles is
shown in Table 1–2.
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Pile-Driving Scenarios
During Phase 1, the POA expects to
utilize three hammers on the job site to
expedite construction, including an
impact hammer for loading platform
construction and an impact hammer and
a vibratory hammer for permanent and
temporary work trestle construction. In
order to mitigate potential impacts to
beluga whales and attempt to maximize
pile installation activities during the
lower density months of occurrence
(May–July), the contractor plans to add
the third crane with a vibratory hammer
to the equipment work mix in order to
accelerate construction of the temporary
and permanent trestles. This could
mean that one vibratory and two impact
hammers may be operating at the same
time along the trestles for brief periods
of time. Use of these hammers could
also be coincidental with use of the
impact hammer for installation of the
platform piles. It is not anticipated that
two vibratory hammers will be
operating at the same time. Section
6.3.2.3 of the IHA application further
details these conditions.
Given the proximity of the platform
and trestle, hammers could work very
close to each other or as far as 100
meters away from each other. The most
likely combinations of piles that could
be installed within a day include (1)
vibratory hammer installation of 24-inch
temporary piles and impact hammer
installation of 48-inch permanent trestle
or loading platform piles, and (2)
vibratory hammer installation of 36-inch
temporary piles and impact hammer
installation of 48-inch permanent trestle
or loading platform piles.
Since only one crane will be
operational during Phase 2, there will be
no additional pile-driving activity
during the impact installation of either
the 36-inch temporary template piles or
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144-inch monopiles. When using two
hammers, one must consider the
accumulated energy, and there are
fundamental approaches for adjusting
source levels to account for the
aforementioned scenarios. While two
impact hammers could work at the same
time, it is unlikely that the hammers
would be dropping at the exact same
time; therefore, two impact hammers
would not necessitate additional
acoustic analysis.
Auxiliary Non-Pile-Driving Activities
Other activities necessary to construct
the PCT involve the installation of
temporary mooring anchor systems,
installation of utility lines and
pipelines, and use of cranes, tugs, and
floating barges. These activities are
described in detail in the POA’s IHA
application. The National Marine
Fisheries Service has evaluated these
activities for the potential to harass
marine mammals. Installation of the
mooring anchor systems would not
elevate noise levels in Knik Arm;
therefore, marine mammal harassment
is not a likely outcome. Utility,
petroleum, and cement lines will extend
between the PCT loading platform and
the shore, and will connect with
existing onshore infrastructure. The
installed utility lines and pipelines will
be supported by the access trestle and
loading platform above marine waters.
No pile installation or removal is
associated with these auxiliary
activities; therefore, no impacts on the
aquatic environment, including elevated
in-water noise, are anticipated from the
installation of utility lines and
pipelines.
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
There are six species of marine
mammals that may be found in upper
Cook Inlet during the proposed pile
driving activities. Sections 3 and 4 of
the POA’s application summarize
available information regarding status
and trends, distribution and habitat
preferences, and behavior and life
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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/marinemammal-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).
Additional information on beluga
whales may be found in NMFS’ 2016
Recovery Plan for the Cook Inlet Beluga
Whale (Delphinapterus leucas),
available online at https://
www.fisheries.noaa.gov/resource/
document/recovery-plan-cook-inletbeluga-whale-delphinapterus-leucas.
Table 3 lists all species with expected
potential for occurrence in upper Cook
Inlet 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 and all values presented in Table
3 are the most recent available at the
time of publication and are available in
the 2019 draft SARs (Muto et al., 2019).
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TABLE 3—MARINE MAMMAL SPECIES POTENTIALLY OCCURRING IN UPPER COOK INLET, ALASKA
Common name
Scientific name
Stock
ESA/
MMPA
status;
strategic
(Y/N) 1
Stock abundance
(CV, Nmin, most recent
abundance survey) 2
Annual
M/SI 3
PBR
Order Cetartiodactyla—Cetacea—Superfamily Mysticeti (baleen whales)
Family Balaenopteridae
(rorquals):
Humpback whale ................
Megaptera novaeangliae ..........
Western North Pacific ....
E/D; Y
1,107 (0.3, 865, 2006) ..............
3
2.6
Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
Family Delphinidae:
Beluga whale ......................
Killer whale .........................
Delphinapterus leucas ..............
Orcinus orca .............................
Cook Inlet .......................
Alaska Resident .............
Alaska Transient .............
E/D; Y
-/-; N
-/-; N
327 (0.06, 311, 2016) ...............
2,347 (N/A, 2,347, 2012) ..........
587 (N/A, 587, 2012) ................
0.54
24
5.9
0
1
1
Family Phocoenidae (porpoises):
Harbor porpoise ..................
Phocoena ..................................
Gulf of Alaska .................
-/-; Y
31,046 (0.214, N/A, 1998) ........
Undet
72
Order Carnivora—Superfamily Pinnipedia
Family Otariidae (eared seals
and sea lions):
Steller sea lion ....................
Family Phocidae (earless seals):
Harbor seal .........................
Eumetopias jubatus ..................
Western ..........................
E/D; Y
54,267 (N/A, 54,267, 2017) ......
326
247
Phoca vitulina ...........................
Cook Inlet/Shelikof .........
-/-; N
28,411 (26,907, N/A, 2018) ......
807
807
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; N
min is the minimum estimate of stock
abundance. In some cases, CV is not applicable because it has not been calculated.
3 These values, found in NMFS’ SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial fisheries,
ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated with estimated mortality due to commercial fisheries is presented in some cases.
As described below, all six species
(comprising six managed MMPA stocks)
temporally and spatially co-occur with
the activity to the degree that take is
reasonably likely to occur, and we have
proposed authorizing it.
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Humpback Whale
Currently, three populations of
humpback whales are recognized in the
North Pacific, migrating between their
respective summer/fall feeding areas
and winter/spring calving and mating
areas (Baker et al. 1998; Calambokidis et
al. 1997). Although there is considerable
distributional overlap in the humpback
whale stocks that use Alaska, the whales
seasonally found in Cook Inlet are
probably of the Central North Pacific
stock (Muto et al. 2017). The Central
North Pacific stock winters in Hawaii
and summers from British Columbia to
the Aleutian Islands (Calambokidis et
al. 1997), including Cook Inlet. The
humpback whale ESA listing final rule
(81 FR 62259, September 8, 2016)
established 14 Distinct Population
Segments (DPSs) with different listing
statuses. The Hawaii DPS is not listed
as threatened or endangered under the
ESA. NMFS is in the process of
reviewing humpback whale stock
structure under the MMPA in light of
the 14 DPSs established under the ESA.
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Humpback whales are encountered
regularly in lower Cook Inlet and
occasionally in mid-Cook Inlet;
however, sightings are rare in upper
Cook Inlet. There have been few
sightings of humpback whales near the
project area. Humpback whales were not
documented during POA construction
or scientific monitoring from 2005 to
2011 or during 2016 (Cornick and
Pinney 2011; Cornick and SaxonKendall 2008, 2009; Cornick and
Seagars 2016; Cornick et al. 2010, 2011;
ICRC 2009a, 2010a, 2011a, 2012;
Markowitz and McGuire 2007; PrevelRamos et al. 2006). Observers
monitoring the Ship Creek Small Boat
Launch from August 23 to September
11, 2017 recorded two sightings, each of
a single humpback whale, which was
presumed to be the same individual.
One other humpback whale sighting has
been recorded for the immediate
vicinity of the project area. This event
involved a stranded whale that was
sighted near a number of locations in
upper Cook Inlet before washing ashore
at Kincaid Park in 2017; it is unclear as
to whether the humpback whale was
alive or deceased upon entering Cook
Inlet waters.
Potential concerns include elevated
levels of sound from anthropogenic
sources (e.g., shipping, military sonars)
but no specific habitat concerns have
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been identified for this stock. Other
potential impacts include harmful algal
blooms (Geraci et al. 1989), possible
changes in prey distribution with
climate change, entanglement in fishing
gear, ship strikes due to increased vessel
traffic (e.g., from increased shipping in
higher latitudes and through the Bering
Sea with changes in sea-ice coverage),
and oil and gas activities. An intentional
unauthorized take of a humpback whale
by Alaska Natives in Toksook Bay was
documented in 2016 (Muto et al., 2019);
however, no subsistence use of
humpback whales occurs in Cook Inlet.
The overall trend for most humpback
whale populations found in U.S. waters
is positive and points toward recovery
(81 FR 62259; September 8, 2016),
indicating that prey availability is not a
major problem. However, a sharp
decline in observed reproduction and
encounter rates of humpback whales
from the Central North Pacific stock
between 2013 and 2018 has been related
to oceanographic anomalies and
consequent impacts on prey resources
(Cartwright et al. 2019), suggesting that
humpback whales are vulnerable to
major environmental changes.
Beluga Whale
The CIBW stock is a small,
geographically isolated population
separated from other beluga populations
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by the Alaska Peninsula. The
population is genetically distinct from
other Alaska populations, suggesting the
peninsula is an effective barrier to
genetic exchange (O’Corry-Crowe et al.
1997). The CIBW population is
estimated to have declined from 1,300
animals in the 1970s (Calkins 1989) to
about 340 animals in 2014 (Shelden et
al. 2015). The precipitous decline
documented in the mid-1990s was
attributed to unsustainable subsistence
practices by Alaska Native hunters
(harvest of >50 whales per year)
(Mahoney and Shelden 2000). In 2006,
a moratorium to cease hunting was
agreed upon to protect the species.
The Cook Inlet beluga stock remains
within Cook Inlet throughout the year
(Goetz et al. 2012a). NMFS designated
two areas, consisting of 7,809 km2
(3,016 mi2) of marine and estuarine
environments considered essential for
the species’ survival and recovery as
critical habitat. However, in recent years
the range of the beluga whale has
contracted to the upper reaches of Cook
Inlet because of the decline in the
population (Rugh et al. 2010). Area 1 of
the CIBW critical habitat encompasses
all marine waters of Cook Inlet north of
a line connecting Point Possession
(61.04° N, 150.37° W) and the mouth of
Three Mile Creek (61.08.55° N,
151.04.40° W), including waters of the
Susitna, Little Susitna, and Chickaloon
Rivers below mean higher high water
(MHHW). This area provides important
habitat during ice-free months and is
used intensively by Cook Inlet beluga
between April and November (NMFS
2016a). More information on CIBW
habitat can be found at https://
www.fisheries.noaa.gov/action/criticalhabitat-cook-inlet-beluga-whale.
Since 1993, NMFS has conducted
annual aerial surveys in June, July or
August to document the distribution
and abundance of beluga whales in
Cook Inlet. The collective survey results
show that beluga whales have been
consistently found near or in river
mouths along the northern shores of
upper Cook Inlet (i.e., north of East and
West Foreland). In particular, beluga
whale groups are seen in the Susitna
River Delta, Knik Arm, and along the
shores of Chickaloon Bay. Small groups
had also been recorded farther south in
Kachemak Bay, Redoubt Bay (Big River),
and Trading Bay (McArthurRiver) prior
to 1996 but very rarely thereafter. Since
the mid-1990s, most (96 to 100 percent)
beluga whales in upper Cook Inlet have
been concentrated in shallow areas near
river mouths, no longer occurring in the
central or southern portions of Cook
Inlet (Hobbs et al. 2008). Based on these
aerial surveys, the concentration of
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beluga whales in the northernmost
portion of Cook Inlet appears to be
consistent from June to October (Rugh et
al. 2000, 2004a, 2005, 2006, 2007).
Research reports generated from the
surveys can be found at https://
www.fisheries.noaa.gov/alaska/
endangered-species-conservation/
research-reports-and-publications-cookinlet-beluga-whales.
Though CIBWs can be found
throughout the inlet at any time of year,
they spend the ice-free months generally
in the upper Cook Inlet, shifting into the
middle and lower Inlet in winter (Hobbs
et al. 2005). In 1999, one beluga whale
was tagged with a satellite transmitter,
and its movements were recorded from
June through September of that year.
Since 1999, 18 beluga whales in upper
Cook Inlet have been captured and fitted
with satellite tags to provide
information on their movements during
late summer, fall, winter, and spring.
Using location data from satellite-tagged
Cook Inlet belugas, Ezer et al. (2013)
found most tagged whales were in the
lower to middle inlet (70 to 100 percent
of tagged whales) during January
through March, near the Susitna River
Delta from April to July (60 to 90
percent of tagged whales) and in the
Knik and Turnagain Arms from August
to December.
More recently, the Marine Mammal
Lab has conducted long-term passive
acoustic monitoring demonstrating
seasonal shifts in CIBW concentrations
throughout Cook Inlet. Castellote et al.
(2015) conducted long-term acoustic
monitoring at 13 locations throughout
Cook Inlet between 2008 and 2015:
North Eagle Bay, Eagle River Mouth,
South Eagle Bay, Six Mile, Point
MacKenzie, Cairn Point, Fire Island,
Little Susitna, Beluga River, Trading
Bay, Kenai River, Tuxedni Bay, and
Homer Spit; the former six stations
being located within Knik Arm. In
general, the observed seasonal
distribution is in accordance with
descriptions based on aerial surveys and
satellite telemetry: Beluga detections are
higher in the upper inlet during
summer, peaking at Little Susitna,
Beluga River, and Eagle Bay, followed
by fewer detections at those locations
during winter. Higher detections in
winter at Trading Bay, Kenai River, and
Tuxedni Bay suggest a broader beluga
distribution in the lower inlet during
winter.
Beluga whales in Cook Inlet are
believed to mostly calve between midMay and mid-July, and concurrently
breed between late spring and early
summer (NMFS 2016a), primarily in
upper Cook Inlet. The only known
observed occurrence of calving occurred
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on July 20, 2015 in the Susitna Delta
area (T. McGuire, pers. comm. March
27, 2017). The first neonates
encountered during each field season
from 2005 through 2015 were always
seen in the Susitna River Delta in July.
The photo ID team’s documentation of
the dates of the first neonate of each
year indicate that calving begins in midlate July/early August, generally
coinciding with the observed timing of
annual maximum group size. Probable
mating behavior of belugas was
observed in April and May of 2014, in
Trading Bay. Young beluga whales are
nursed for two years and may continue
to associate with their mothers for a
considerable time thereafter (Colbeck et
al. 2013).
During the spring and summer, beluga
whales are generally concentrated near
the warmer waters of river mouths
where prey availability is high and
predator occurrence is low (Moore et al.
2000). Goetz et al. (2012b) modeled
habitat preferences using NMFS’ 1994–
2008 June abundance survey data. In
large areas, such as the Susitna Delta
(Beluga to Little Susitna Rivers) and
Knik Arm, there was a high probability
that beluga whales were in larger group
sizes. Beluga whale presence also
increased closer to rivers with Chinook
salmon (Oncorhynchus tshawytscha)
runs, such as the Susitna River.
Movement has been correlated with the
peak discharge of seven major rivers
emptying into Cook Inlet. Boat-based
surveys from 2005 to the present
(McGuire and Stephens 2017), and
initial results from passive acoustic
monitoring across the entire inlet
(Castellote et al. 2015) also support
seasonal patterns observed with other
methods. Based on long-term passive
acoustic monitoring, seasonally,
foraging behavior was more prevalent
during summer, particularly at upper
inlet rivers, than during winter.
Foraging index was highest at Little
Susitna, with a peak in July-August and
a secondary peak in May, followed by
Beluga River and then Eagle Bay;
monthly variation in the foraging index
indicates belugas shift their foraging
behavior among these three locations
from April through September.
Despite protection from hunting, this
stock continues to decline. The
population was declining at the end of
the period of unregulated harvest, with
the relatively steep decline ending in
1999, coincident with harvest removals
dropping from an estimated 42 in 1998
to just 0 to 2 whales per year in 2000
to 2006 (and with no removals after
2006). From 1999 to 2016, the rate of
decline of the population was estimated
to be 0.4% (SE = 0.6%) per year, with
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a 73% probability of a population
decline. While from 2006 to 2016, the
most recent 10-year period, the rate of
decline was estimated to be 0.5% per
year, (with a 70% probability of a
population decline) (Shelden et al.
2017). No human-caused mortality or
serious injury of CIBWs has been
recently documented. Other potential
threats most likely to result in direct
human-caused mortality or serious
injury of this stock include ship strikes.
Mortality related to live stranding
events, where a beluga whale group
strands as the tide recedes, has been
regularly observed in upper Cook Inlet.
Most whales involved in a live
stranding event survive, although some
associated deaths may not be observed
if the whales die later from livestranding-related injuries (Vos and
Shelden 2005, Burek-Huntington et al.
2015). Between 2013 and 2017, there
were reports of approximately 78 beluga
whales involved in two known live
stranding events, plus one suspected
live stranding event with two associated
deaths reported. In 2014, necropsy
results from two whales found in
Turnagain Arm suggested that a live
stranding event contributed to their
deaths as both had aspirated mud and
water. No live stranding events were
reported prior to the discovery of these
dead whales, suggesting that not all live
stranding events are observed. Most live
strandings occur in Knik Arm and
Turnagain Arm, which are shallow and
have big tides. Another source of beluga
whale mortality in Cook Inlet is
predation by transient-type (mammaleating) killer whales.
In its Recovery Plan (NMFS, 2016),
NMFS identified several threats to
CIBWs. Potential threats include: (1)
High concern: Catastrophic events (e.g.,
natural disasters, spills, mass
strandings), cumulative effects of
multiple stressors, and noise; (2)
medium concern: Disease agents (e.g.,
pathogens, parasites, and harmful algal
blooms), habitat loss or degradation,
reduction in prey, and unauthorized
take; and (3) low concern: Pollution,
predation, and subsistence harvest. The
recovery plan did not treat climate
change as a distinct threat but rather as
a consideration in the threats of high
and medium concern.
Killer Whale
Two stocks of killer whales may be
present in upper Cook Inlet: The Eastern
North Pacific Alaska Residents and the
Gulf of Alaska, Aleutian Islands, and
Bering Sea Transients. Both ecotypes
overlap in the same geographic area;
however, they maintain social and
reproductive isolation and feed on
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different prey species. During aerial
surveys conducted between 1993 and
2004, killer whales were observed on
only three flights, all in the Kachemak
and English Bay area (Rugh et al. 2005).
Anecdotal reports of killer whales
feeding on belugas in upper Cook Inlet
began increasing in the 1990s; several of
these sightings and strandings report
killer whale predation on beluga
Whales.
No killer whales were spotted in the
vicinity of the POA during surveys by
Funk et al. (2005), Ireland et al. (2005),
or Brueggeman et al. (2007, 2008a,
2008b). No killer whale sightings were
documented during POA construction
or scientific monitoring from 2005 to
2011 or during the 2016 TPP. Very few
killer whales, if any, are expected to
approach or be near the project area
during construction of the PCT.
There are no reports of a subsistence
harvest of killer whales in Alaska. Based
on currently available data, a minimum
estimate of the mean annual mortality
and serious injury rate for both the
Alaska Residents and transient stocks
due to U.S. commercial fisheries is less
than 10% of the PBR and, therefore, is
considered to be insignificant and
approaching zero mortality and serious
injury rate. Therefore, neither stock is
classified as a strategic stock.
Harbor Porpoise
Harbor porpoises primarily frequent
the coastal waters of the Gulf of Alaska
and Southeast Alaska (Dahlheim et al.
2000, 2008), typically occurring in
waters less than 100 m deep (Hobbs and
Waite 2010). Harbor porpoise prefer
nearshore areas, bays, tidal areas, and
river mouths (Dahlheim et al. 2000,
Hobbs and Waite 2010). In Alaskan
waters, NMFS has designated three
stocks of harbor porpoises for
management purposes: Southeast
Alaska, Gulf of Alaska, and Bering Sea
Stocks (Muto et al. 2017). Porpoises
found in Cook Inlet belong to the Gulf
of Alaska Stock, which is distributed
from Cape Suckling to Unimak Pass.
Although harbor porpoise have been
frequently observed during aerial
surveys in Cook Inlet (Shelden et al.
2014), most sightings are of single
animals, and are concentrated at
Chinitna and Tuxedni Bays on the west
side of lower Cook Inlet (Rugh et al.
2005) and in the upper inlet. The
occurrence of larger numbers of
porpoise in the lower Cook Inlet may be
driven by greater availability of
preferred prey and possibly less
competition with beluga whales, as
belugas move into upper inlet waters to
forage on Pacific salmon during the
summer months (Shelden et al. 2014).
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There has been an increase in harbor
porpoise sightings in upper Cook Inlet
over the past two decades (Shelden et
al. 2014). Small numbers of harbor
porpoises have been consistently
reported in upper Cook Inlet between
April and October (Prevel-Ramos et al.
2008). Harbor porpoises have been
observed within Knik Arm during
monitoring efforts since 2005. During
POA construction from 2005 through
2011 and in 2016, harbor porpoises
were reported in 2009, 2010, and 2011
(Cornick and Saxon-Kendall 2008, 2009;
Cornick and Seagars 2016; Cornick et al.
2010, 2011; Markowitz and McGuire
2007; Prevel-Ramos et al. 2006; Table
4–2). In 2009, a total of 20 harbor
porpoises were observed during
construction monitoring, with sightings
in June, July, August, October, and
November. Harbor porpoises were
observed twice in 2010, once in July and
again in August. In 2011, POA
monitoring efforts documented harbor
porpoises five times, with a total of six
individuals, in August, October, and
November at the POA (Cornick et al.
2011). During other monitoring efforts
conducted in Knik Arm, there were four
sightings of harbor porpoises in 2005
(Shelden et al. 2014), and a single
harbor porpoise was observed within
the vicinity of the POA in October 2007.
Estimates of human-caused mortality
and serious injury from stranding data
and fisherman self-reports are
underestimates because not all animals
strand or are self-reported nor are all
stranded animals found, reported, or
have the cause of death determined. In
addition, the trend of this stock is
unknown given data is more than eight
years old. Given their shallow water
distribution, harbor porpoise are
vulnerable to physical modifications of
nearshore habitats resulting from urban
and industrial development (including
waste management and nonpoint source
runoff) and activities such as
construction of docks and other overwater structures, filling of shallow areas,
dredging, and noise (Linnenschmidt et
al. 2013). Subsistence users have not
reported any harvest from the Gulf of
Alaska harbor porpoise stock since the
early 1900s (Shelden et al. 2014).
Steller Sea Lion
Steller sea lions inhabiting Cook Inlet
belong to the western distinct
population segment (WDPS), and this is
the stock considered in this analysis.
NMFS defines the Steller sea lion WDPS
as all populations west of longitude
144° W to the western end of the
Aleutian Islands. The most recent
comprehensive aerial photographic and
land-based surveys of WDPS Steller sea
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lions in Alaska were conducted during
the 2014 and 2015 breeding seasons
(Fritz et al. 2015). The WDPS of Steller
sea lions is currently listed as
endangered under the ESA (55 FR
49204, November 26, 1990) and
designated as depleted under the
MMPA. NMFS designated critical
habitat on August 27, 1993 (58 FR
45269). The critical habitat designation
for the WDPS of Steller sea lions was
determined to include a 37 km (20 nm)
buffer around all major haul outs and
rookeries, and associated terrestrial,
atmospheric, and aquatic zones, plus
three large offshore foraging areas, none
of which occurs in the project area.
Steller sea lions feed largely on walleye
pollock, salmon, and arrowtooth
flounder during the summer, and
walleye pollock and Pacific cod during
the winter (Sinclair and Zeppelin 2002).
Except for salmon, none of these are
found in abundance in upper Cook Inlet
(Nemeth et al. 2007).
Within Cook Inlet, Steller sea lions
primarily inhabit lower Cook Inlet.
However, they occasionally venture to
upper Cook Inlet and Knik Arm. Steller
sea lions have been observed near the
POA in June 2009 (ICRC 2009a) and in
May 2016 (Cornick and Seagars 2016).
During POA construction monitoring in
June of 2009, a Steller sea lion was
documented three times (within the
same day) in Knik Arm and was
believed to be the same individual
(ICRC 2009a). In 2016, Steller sea lions
were observed on two separate days. On
May w, 2016, one individual was
sighted. On May 25, 2016, there were
five Steller sea lion sightings within a
50-minute period, and these sightings
occurred in areas relatively close to one
another suggesting they were likely the
same animal (Cornick and Seagars
2016). Steller sea lions are likely
attracted to the salmon runs; however,
their presence is less common in upper
Cook Inlet than lower Cook Inlet.
The total estimated annual level of
human-caused mortality and serious
injury for Western U.S. Steller sea lions
in 2012–2016 was 247 sea lions: 35 in
U.S. commercial fisheries, 1.2 in
unknown (commercial, recreational, or
subsistence) fisheries, 2 in marine
debris, 5.5 due to other causes (arrow
strike, entangled in hatchery net, illegal
shooting, Marine Mammal Protection
Act (MMPA) authorized researchrelated), and 203 in the Alaska Native
subsistence harvest. However, there are
multiple nearshore commercial fisheries
which are not observed; thus, there is
likely to be unreported fishery-related
mortality and serious injury of Steller
sea lions.
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Several factors may have been
important drivers of the decline of the
stock. However, there is uncertainty
about threats currently impeding their
recovery, particularly in the Aleutian
Islands. Many factors have been
suggested as causes of the steep decline
in abundance of western Steller sea
lions observed in the 1980s, including
competitive effects of fishing,
environmental change, disease,
contaminants, killer whale predation,
incidental take, and illegal and legal
shooting (Atkinson et al. 2008, NMFS
2008). A number of management actions
have been implemented since 1990 to
promote the recovery of the Western
U.S. stock of Steller sea lions, including
3-nmi no-entry zones around rookeries,
prohibition of shooting at or near sea
lions, and regulation of fisheries for sea
lion prey species (e.g., walleye pollock,
Pacific cod, and Atka mackerel)
(Sinclair et al. 2013, Tollit et al. 2017).
Harbor Seal
Harbor seals belonging to the Cook
Inlet/Shelikof Strait stock inhabit the
coastal and estuarine waters of Cook
Inlet and are observed in both upper
and lower Cook Inlet throughout most of
the year (Boveng et al. 2012; Shelden et
al. 2013). Recent research on satellitetagged harbor seals observed several
movement patterns within Cook Inlet
(Boveng et al. 2012). In the fall, a
portion of the harbor seals appeared to
move out of Cook Inlet and into Shelikof
Strait, northern Kodiak Island, and
coastal habitats of the Alaska Peninsula.
The western coast of Cook Inlet had
higher usage by harbor seals than
eastern coast habitats, and seals
captured in lower Cook Inlet generally
exhibited site fidelity by remaining
south of the Forelands in lower Cook
Inlet after release (Boveng et al. 2012).
The presence of harbor seals in upper
Cook Inlet is seasonal. Harbor seals are
commonly observed along the Susitna
River and other tributaries within upper
Cook Inlet during eulachon and salmon
migrations (NMFS 2003). The major
haulout sites for harbor seals are located
in lower Cook Inlet with fewer sites in
upper Cook Inlet (Montgomery et al.
2007). In the project area (Knik Amr),
harbor seals tend to congregate near the
mouth of Ship Creek (Cornick et al.
2011; Shelden et al. 2013), likely
foraging on salmon and eulachon runs.
Approximately 138 harbor seals were
observed during previous POA
monitoring with sightings ranging from
3 individuals in 2008 to 59 individuals
in 2011 (see Table 4–1 in POA’s
application).
The most current population trend
estimate of the Cook Inlet/Shelikof
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Strait stock is approximately ¥111 seals
per year, with a probability that the
stock is decreasing of 0.609 (Muto et al.,
2015). The estimated level of humancaused mortality and serious injury for
this stock is 234 seals, of which 233
seals are taken for subsistence uses.
Additional potential threats most likely
to result in direct human-caused
mortality or serious injury for all stocks
of harbor seals in Alaska include
unmonitored subsistence harvests,
incidental takes in commercial fisheries,
and illegal shooting. Disturbance by
cruise vessels is an additional threat for
harbor seal stocks that occur in glacial
fjords (Jansen et al. 2010, 2015;
Matthews et al. 2016). The average
annual harvest of this stock of harbor
seals between 2004 and 2008 was 233
seals per year. The annual harvest in
2014 was 104 seals (Muto et al., 2019).
In addition, sea otters (Enhydra lutris)
may be found in Cook Inlet. However,
sea otters are managed by the U.S. Fish
and Wildlife Service and are not
considered further in this document.
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 lowfrequency cetaceans where the lower
bound was deemed to be biologically
implausible and the lower bound from
Southall et al. (2007) retained. Marine
mammal hearing groups and their
associated hearing ranges are provided
in Table 4.
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TABLE 4—MARINE MAMMAL HEARING GROUPS
[NMFS, 2018]
Hearing group
Generalized hearing
range *
Low-frequency (LF) cetaceans (baleen whales) .........................................................................................................................
Mid-frequency (MF) cetaceans (dolphins, toothed whales, beaked whales, bottlenose whales) ..............................................
High-frequency (HF) cetaceans (true porpoises, Kogia, river dolphins, cephalorhynchid, Lagenorhynchus cruciger & L.
australis).
Phocid pinnipeds (PW) (underwater) (true seals) .......................................................................................................................
Otariid pinnipeds (OW) (underwater) (sea lions and fur seals) ..................................................................................................
7 Hz to 35 kHz.
150 Hz to 160 kHz.
275 Hz to 160 kHz.
50 Hz to 86 kHz.
60 Hz to 39 kHz.
* 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
(Hemila¨ 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. Six marine
mammal species (four cetacean and two
pinniped (one otariid and one phocid)
species) have the reasonable potential to
co-occur with the proposed survey
activities. Please refer to Table 3. Of the
cetacean species that may be present,
one is classified as a low-frequency
cetacean (i.e., all mysticete species), two
are classified as mid-frequency
cetaceans (i.e., all delphinid and ziphiid
species and the sperm whale), and one
is classified as a high-frequency
cetacean (i.e., harbor porpoise and Kogia
spp.).
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Potential Effects of Specified Activities
on Marine Mammals and Their Habitat
This section includes a summary and
discussion of the ways that components
of the specified activity may impact
marine mammals and their habitat. The
Estimated Take by Incidental
Harassment section later in this
document includes a quantitative
analysis of the number of individuals
that are expected to be taken by this
activity. The Negligible Impact Analysis
and Determination section considers the
content of this section, the Estimated
Take by Incidental Harassment section,
and the Proposed Mitigation section, to
draw conclusions regarding the likely
impacts of these activities on the
reproductive success or survivorship of
individuals and how those impacts on
individuals are likely to impact marine
mammal species or stocks.
Description of Sound Sources—The
primary relevant stressor to marine
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mammals from the proposed activity is
the introduction of noise into the
aquatic environment; therefore, we
focus our impact analysis on the effects
of anthropogenic noise on marine
mammals. To better understand the
potential impacts of exposure to pile
driving noise, we describe sound source
characteristics below. Specifically, we
look at the following two ways to
characterize sound: by its temporal (i.e.,
continuous or intermittent) and its pulse
(i.e., impulsive or non-impulsive)
properties. Continuous sounds are those
whose sound pressure level remains
above that of the ambient sound, with
negligibly small fluctuations in level
(NIOSH, 1998; ANSI, 2005), while
intermittent sounds are defined as
sounds with interrupted levels of low or
no sound (NIOSH, 1998). Impulsive
sounds, such as those generated by
impact pile driving, are typically
transient, brief (<1 sec), broadband, and
consist of a high peak pressure with
rapid rise time and rapid decay (ANSI,
1986; NIOSH, 1998). The majority of
energy in pile impact pulses is at
frequencies below 500 Hz. Impulsive
sounds, by definition, are intermittent.
Non-impulsive sounds, such as those
generated by vibratory pile driving, can
be broadband, narrowband or tonal,
brief or prolonged, and typically do not
have a high peak sound pressure with
rapid rise/decay time that impulsive
sounds do (ANSI 1995; NIOSH 1998).
Non-impulsive sounds can be
intermittent or continuous. Similar to
impact pile driving, vibratory pile
driving generates low frequency sounds.
Vibratory pile driving is considered a
non-impulsive, continuous source.
Discussion on the appropriate
harassment threshold associated with
these types of sources based on these
characteristics can be found in the
Estimated Take section.
Potential Effects of the Specified
Activity—In general, the effects of
sounds from pile driving to marine
mammals might result in one or more of
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the following: Temporary or permanent
hearing impairment, non-auditory
physical or physiological effects,
behavioral disturbance, and masking
(Richardson et al., 1995; Gordon et al.,
2004; Nowacek et al., 2007; Southall et
al., 2007). The potential for and
magnitude of these effects are
dependent on several factors, including
received characteristics (e.g., age, size,
depth of the animal during exposure);
the energy needed to drive the pile
(usually related to pile size, depth
driven, and substrate), the standoff
distance between the pile and receiver;
and the sound propagation properties of
the environment.
Impacts to marine mammals from pile
driving activities are expected to result
primarily from acoustic pathways. As
such, the degree of effect is intrinsically
related to the received level and
duration of the sound exposure, which
are in turn influenced by the distance
between the animal and the source. The
further away from the source, the less
intense the exposure should be. The
substrate and depth of the habitat affect
the sound propagation properties of the
environment. Shallow environments are
typically more structurally complex,
which leads to rapid sound attenuation.
In addition, substrates that are soft (e.g.,
sand) absorb or attenuate the sound
more readily than hard substrates (e.g.,
rock) which may reflect the acoustic
wave. Soft porous substrates also likely
require less time to drive the pile, and
possibly less forceful equipment, which
ultimately decrease the intensity of the
acoustic source.
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
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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
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., permanent hearing impairment,
certain non-auditory physical or
physiological effects) only briefly as we
do not expect that there is a reasonable
likelihood that POA’s activities would
result in such effects (see below for
further discussion).
NMFS defines a noise-induced
threshold shift (TS) as ‘‘a change,
usually an increase, in the threshold of
audibility at a specified frequency or
portion of an individual’s hearing range
above a previously established reference
level’’ (NMFS, 2016). The amount of
threshold shift is customarily expressed
in dB (ANSI 1995, Yost 2007). A TS can
be permanent (PTS) or temporary (TTS).
As described in NMFS (2018), there are
numerous factors to consider when
examining the consequence of TS,
including, but not limited to, the signal
temporal pattern (e.g., impulsive or nonimpulsive), likelihood an individual
would be exposed for a long enough
duration or to a high enough level to
induce a TS, the magnitude of the TS,
time to recovery (seconds to minutes or
hours to days), the frequency range of
the exposure (i.e., spectral content), the
hearing and vocalization frequency
range of the exposed species relative to
the signal’s frequency spectrum (i.e.,
how animal uses sound within the
frequency band of the signal; e.g.,
Kastelein et al., 2014), and the overlap
between the animal and the source (e.g.,
spatial, temporal, and spectral). When
analyzing the auditory effects of noise
exposure, it is often helpful to broadly
categorize sound as either impulsive—
noise with high peak sound pressure,
short duration, fast rise-time, and broad
frequency content—or non-impulsive.
When considering auditory effects,
vibratory pile driving is considered a
non-impulsive source while impact pile
driving is treated as an impulsive
source.
Permanent Threshold Shift—NMFS
defines PTS as a permanent, irreversible
increase in the threshold of audibility at
a specified frequency or portion of an
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individual’s hearing range above a
previously established reference level
(NMFS 2018). Available data from
humans and other terrestrial mammals
indicate that a 40 dB threshold shift
approximates PTS onset (see NMFS
2018 for review).
Temporary Threshold Shift—NMFS
defines TTS as a temporary, reversible
increase in the threshold of audibility at
a specified frequency or portion of an
individual’s hearing range above a
previously established reference level
(NMFS 2018). Based on data from
cetacean TTS measurements (see
Finneran 2014 for a review), a TTS of
6 dB is considered the minimum
threshold shift clearly larger than any
day-to-day or session-to-session
variation in a subject’s normal hearing
ability (Schlundt et al., 2000; Finneran
et al., 2000; Finneran et al., 2002).
Depending on the degree (elevation of
threshold in dB), duration (i.e., recovery
time), and frequency range of TTS, and
the context in which it is experienced,
TTS can have effects on marine
mammals ranging from discountable to
serious (similar to those discussed in
auditory masking, below). For example,
a marine mammal may be able to readily
compensate for a brief, relatively small
amount of TTS in a non-critical
frequency range that takes place during
a time when the animal is traveling
through the open ocean, where ambient
noise is lower and there are not as many
competing sounds present.
Alternatively, a larger amount and
longer duration of TTS sustained during
time when communication is critical for
successful mother/calf interactions
could have more serious impacts. We
note that reduced hearing sensitivity as
a simple function of aging has been
observed in marine mammals, as well as
humans and other taxa (Southall et al.,
2007), so we can infer that strategies
exist for coping with this condition to
some degree, though likely not without
cost.
Schlundt et al. (2000) performed a
study exposing five bottlenose dolphins
and two belugas (same individuals as
Finneran’s studies) to intense 1 second
tones at different frequencies. The
resulting levels of fatiguing stimuli
necessary to induce 6 dB or larger
masked TTSs were generally between
192 and 201 dB re: 1 microPascal (mPa).
Dolphins began to exhibit altered
behavior at levels of 178–193 dB re:
1mPa and above; belugas displayed
altered behavior at 180–196 dB re: 1 mPa
and above. At the conclusion of the
study, all thresholds were at baseline
values.
There are a limited number of studies
investigating the potential for cetacean
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TTS from pile driving and only one has
elicited a small amount of TTS in a
single harbor porpoise individual
(Kastelein et al., 2015). However,
captive bottlenose dolphins and beluga
whales have exhibited changes in
behavior when exposed to pulsed
sounds (Finneran et al., 2000, 2002,
2005). The animals tolerated high
received levels of sound before
exhibiting aversive behaviors.
Experiments on a beluga whale showed
that exposure to a single watergun
impulse at a received level of 207 kPa
(30 psi) p-p, which is equivalent to 228
dB p-p, resulted in a 7 and 6 dB TTS
in the beluga whale at 0.4 and 30 kHz,
respectively. Thresholds returned to
within 2 dB of the pre-exposure level
within four minutes of the exposure
(Finneran et al., 2002). Although the
source level of pile driving from one
hammer strike is expected to be lower
than the single watergun impulse cited
here, animals being exposed for a
prolonged period to repeated hammer
strikes could receive more sound
exposure in terms of SEL than from the
single watergun impulse (estimated at
188 dB re 1 mPa2-s) in the
aforementioned experiment (Finneran et
al., 2002). Results of these studies
suggest odontocetes are susceptible to
TTS from pile driving, but that they
seem to recover quickly from at least
small amounts of TTS.
Behavioral Harassment—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.
Disturbance may result in changing
durations of surfacing and dives,
number of blows per surfacing, or
moving direction and/or speed;
reduced/increased vocal activities;
changing/cessation of certain behavioral
activities (such as socializing or
feeding); visible startle response or
aggressive behavior (such as tail/fluke
slapping or jaw clapping); avoidance of
areas where sound sources are located.
Pinnipeds may increase their haul out
time, possibly to avoid in-water
disturbance (Thorson and Reyff 2006).
Behavioral responses to sound are
highly variable and context-specific and
any reactions depend on numerous
intrinsic and extrinsic factors (e.g.,
species, state of maturity, experience,
current activity, reproductive state,
auditory sensitivity, time of day), as
well as the interplay between factors
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(e.g., Richardson et al. 1995; Wartzok et
al. 2003; Southall et al. 2007; Weilgart
2007; Archer et al. 2010). Behavioral
reactions can vary not only among
individuals but also within an
individual, depending on previous
experience with a sound source,
context, and numerous other factors
(Ellison et al. 2012), and can vary
depending on characteristics associated
with the sound source (e.g., whether it
is moving or stationary, number of
sources, distance from the source). In
general, pinnipeds seem more tolerant
of, or at least habituate more quickly to,
potentially disturbing underwater sound
than do cetaceans, and generally seem
to be less responsive to exposure to
industrial sound than most cetaceans.
Please see Appendices B–C of Southall
et al. (2007) for a review of studies
involving marine mammal behavioral
responses to sound.
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
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 above, 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 seismic 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).
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
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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,b).
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.
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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,
2005b, 2006; Gailey et al., 2007).
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 (Eubalaena glacialis)
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., 2007b). 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 (Eschrictius robustus) are
known to change direction—deflecting
from customary migratory paths—in
order to avoid noise from seismic
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
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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.
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 fiveday 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
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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-pituitaryadrenal 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
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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).
Specific to CIBWs, we have several
years of marine mammal monitoring
data demonstrating the behavioral
responses to pile driving at the POA.
Previous pile driving activities range
from the installation and removal of
sheet pile driving to installation of 48in pipe piles with both vibratory and
impact hammers. Kendell and Cornick
(2016) provide a comprehensive
overview of four years of scientific
marine mammal monitoring conducted
during the POA’s Expansion Project.
These were observations made
independent of pile driving activities
(i.e., not construction based PSOs). The
authors investigated beluga whale
behavior before and during pile driving
activity at the POA. Sighting rates, mean
sighting duration, behavior, mean group
size, group composition, and group
formation were compared between the
two periods. A total of about 2,329 h of
sampling effort was completed across
349 d from 2005 to 2009. Overall, 687
whales in 177 groups were documented
during the 69 days that whales were
sighted. A total of 353 and 1,663 h of
pile driving activity took place in 2008
and 2009, respectively. There was no
relationship between monthly beluga
whale sighting rates and monthly pile
driving rates (r = 0.19, p = 0.37).
Sighting rates before (n = 12; 0.06 ±
0.01) and during (n = 13; 0.01 ± 0.03)
pile driving activity were not
significantly different. However,
sighting duration of beluga whales
decreased significantly during pile
driving (39 ± 6 min before and 18 ± 3
min during). There were also significant
differences in behavior before versus
during pile driving. Beluga whales
primarily traveled through the study
area both before and during pile driving;
however, traveling increased relative to
other behaviors during pile driving
activity. Suspected feeding decreased
during pile driving although the sample
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size was low as feeding was observed on
only two occasions before pile driving
and on zero occasions during pile
driving. Documentation of milling began
in 2008 and was observed on 21
occasions. No acute behavioral
responses were documented. Mean
group size decreased during pile
driving; however, this difference was
not statistically significant. There were
significant differences in group
composition before and during pile
driving ship between monthly beluga
whale sighting rates and monthly pile
driving rates with more white (i.e.,
older) animals being present during pile
driving.
Acoustically, Kendall et al. (2013)
only recorded echolocation clicks and
no whistles or noisy vocalizations near
construction activity at the POA. Beluga
whales have been occasionally
documented to forage around Ship
Creek (south of the POA) but, during
pile driving, may choose to move past
the POA to other, potentially richer,
feeding areas further into Knik Arm
(e.g., Six Mile Creek, Eagle River,
Eklutna River). These locations contain
predictable salmon runs (ADFG, 2010),
an important food source for CIBWss
(NMFS1), and the timing of these runs
has been correlated with beluga whale
movements into the upper reaches of
Knik Arm (Ezer et al., 2013).
Auditory Masking
Since many marine mammals rely on
sound to find prey, moderate social
interactions, and facilitate mating
(Tyack, 2008), noise from anthropogenic
sound sources can interfere with these
functions, but only if the noise spectrum
overlaps with the hearing sensitivity of
the marine mammal (Southall et al.,
2007; Clark et al., 2009; Hatch et al.,
2012). Chronic exposure to excessive,
though not high-intensity, noise could
cause masking at particular frequencies
for marine mammals that utilize sound
for vital biological functions (Clark et
al., 2009). Acoustic masking is when
other noises such as from human
sources interfere with animal detection
of acoustic signals such as
communication calls, echolocation
sounds, and environmental sounds
important to marine mammals.
Therefore, under certain circumstances,
marine mammals whose acoustical
sensors or environment are being
severely masked could also be impaired
from maximizing their performance
fitness in survival and reproduction.
Masking, which can occur over large
temporal and spatial scales, can
potentially affect the species at
population, community, or even
ecosystem levels, as well as individual
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levels. Masking affects both senders and
receivers of the signals and could have
long-term chronic effects on marine
mammal species and populations.
Masking occurs at the frequency band
which the animals utilize so the
frequency range of the potentially
masking sound is important in
determining any potential behavioral
impacts. Pile driving generates low
frequency sounds; therefore, mysticete
foraging is likely more affected than
odontocetes given very high frequency
echolocation clicks (typically associated
with odontocete foraging) are likely
unmasked to any significant degree.
However, lower frequency man-made
sounds may affect communication
signals when they occur near the sound
band and thus reduce the
communication space of animals (e.g.,
Clark et al., 2009) and cause increased
stress levels (e.g., Foote et al., 2004; Holt
et al., 2009).
Moreover, even within a given
species, different types of man-made
noises may results in varying degrees of
masking. For example, Erbe et al. (1999)
and Erbe (2000), analyzed the effect of
masking of beluga calls by exposing a
trained beluga to icebreaker propeller
noise, an icebreaker’s bubbler system,
and ambient Arctic ice cracking noise,
and found that the latter was the least
problematic for the whale detecting the
calls. Sheifele et al. (2005) studied a
population of belugas in the SLE to
determine whether beluga vocalizations
showed intensity changes in response to
shipping noise. This type of behavior
has been observed in humans and is
known as the Lombard vocal response
(Lombard 1911). Sheifele et al. (2005)
demonstrated that shipping noise did
cause belugas to vocalize louder. The
acoustic behavior of this same
population of belugas was studied in the
presence of ferry and small boat noise.
Lesage et al. (1999) described more
persistent vocal responses when whales
were exposed to the ferry than to the
small-boat noise. These included a
progressive reduction in calling rate
while vessels were approaching, an
increase in the repetition of specific
calls, and a shift to higher frequency
bands used by vocalizing animals when
vessels were close to the whales. The
authors concluded that these changes,
and the reduction in calling rate to
almost silence, may reduce
communication efficiency which is
critical for a species of a gregarious
nature. However, the authors also stated
that because of the gregarious nature of
belugas, this ‘‘would not pose a serious
problem for intraherd communication’’
of belugas given the short distance
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between group members, and concluded
a noise source would have to be very
close to potentially limit any
communication within the beluga group
(Lesage et al. 1999). However, increasing
the intensity or repetition rate, or
shifting to higher frequencies when
exposed to shipping noise (from
merchant, whale watching, ferry and
small boats), is indicative of an increase
of energy costs (Bradbury and
Vehrencamp 1998).
Marine mammals in Cook Inlet are
continuously exposed to anthropogenic
noise which may lead to some
habituation but is also a source of
masking. A subsample (8,756 hours) of
the acoustic recordings collected by the
Cook Inlet Beluga Acoustics research
program in Cook Inlet, Alaska, from July
2008 to May 2013, were analyzed to
describe anthropogenic sources of
underwater noise, acoustic
characteristics, and frequency of
occurrence and evaluate the potential
for acoustic impact to Cook Inlet
belugas. As described in Castellote et al.
(2016), a total of 13 sources of noise
were identified: Commerical ship,
dredging, helicopter, jet aircraft
(commercial or non-fighter), jet aircraft
(military fighter), outboard engine
(small skiffs, rafts), pile driving,
propeller aircraft, sub-bottom profiler,
unclassified machinery (continuous
mechanical sound; e.g., engine),
unidentified ‘clank’ or ‘bang’ (impulsive
mechanical sound; e.g., barge dumping),
unidentified (unclassifiable
anthropogenic sound), unknown up- or
down-sweep (modulated tone of
mechanical origin; e.g., hydraulics). A
total of 6,263 anthropogenic acoustic
events were detected and classified,
which had a total duration of 1,025
hours and represented 11.7% of the
sound recordings analyzed. There was
strong variability in source diversity,
loudness, distribution, and seasonal
occurrence of noise, which reflects the
many different activities within the
Cook Inlet. Cairn Point was the location
where the loudness and duration of
commercial ship noise events were most
concentrated, due to activities at the
POA. This specific source of
anthropogenic noise was present in the
recordings from all months analyzed,
with highest levels in August. In
addition to the concentrated shipping
noise at Cairn Point, a combination of
unknown noiseclasses occurred in this
area, particularly during summer.
Specifically, unknown up or down
sweeps, unidentified, unclassed
machinery, and unidentified clank or
bang noise classes were all documented.
In contrast, Eagle River (north of the
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POA and where CIBWs concentrate to
forage) was the quietest of all sampled
locations.
Potential Pile Driving Effects on
Prey—Pile driving produces continuous,
non-impulsive (i.e., vibratory pile
driving) sounds and intermittent, pulsed
(i.e., impact driving) sounds. Fish react
to sounds that are especially strong and/
or intermittent low-frequency sounds.
Short duration, sharp sounds can cause
overt or subtle changes in fish behavior
and local distribution. Hastings and
Popper (2005) identified several studies
that suggest fish may relocate to avoid
certain areas of sound energy.
Additional studies have documented
effects of pile driving on fish, although
several are based on studies in support
of large, multiyear bridge construction
projects (e.g., Scholik and Yan, 2001,
2002; Popper and Hastings, 2009). SPLs
of sufficient strength have been known
to cause injury to fish and fish mortality
(summarized in Popper et al. 2014). The
most likely impact to fish from pile
driving activities at the project area
would be temporary behavioral
avoidance of the area. The duration of
fish avoidance of this area after pile
driving stops is unknown, but a rapid
return to normal recruitment,
distribution and behavior is anticipated.
As discussed in the Marine Mammal
section above, NMFS designated CIBW
critical habitat in Knik Arm. Knik Arm
is Type 1 habitat for the CIBWs, which
means it is the most valuable, used
intensively by beluga whales from
spring through fall for foraging and
nursery habitat. However, the POA, the
adjacent navigation channel, and the
turning basin were excluded from
critical habitat designation due to
national security concerns (76 FR
20180, April 11, 2011). Foraging
primarily occurs at river mouths (e.g.,
Susitna Delta, Eagle River flats) which
are unlikely to be influenced by pile
driving activities. The Susitna Delta is
more than 20 km from the POA and
Cairn Point is likely to impede any pile
driving noise from propagating into
northern Knik Arm.
Acoustic habitat is the soundscape
which encompasses all of the sound
present in a particular location and
time, as a whole, when considered from
the perspective of the animals
experiencing it. Animals produce sound
for, or listen for sounds produced by,
conspecifics (communication during
feeding, mating, and other social
activities), other animals (finding prey
or avoiding predators) and the physical
environment (finding suitable habitats,
navigating). Together, sounds made by
animals and the geophysical
environment (e.g., produced by
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earthquakes, lightning, wind, rain,
waves) make up the natural
contributions to the total acoustics of a
place. These acoustic conditions,
termed acoustic habitat, are one
attribute of an animal’s total habitat.
Soundscapes are also defined by, and
acoustic habitat influenced by, the total
contribution of anthropogenic sound.
This may include incidental emissions
from sources such as vessel traffic or
may be intentionally introduced to the
marine environment for data acquisition
purposes (as in the use of airgun arrays
or other sources). Anthropogenic noise
varies widely in its frequency content,
duration, and loudness and these
characteristics greatly influence the
potential habitat-mediated effects to
marine mammals (please see also the
previous discussion on masking under
‘‘Acoustic Effects’’), which may range
from local effects for brief periods of
time to chronic effects over large areas
and for long durations. Depending on
the extent of effects to habitat, animals
may alter their communications signals
(thereby potentially expending
additional energy) or miss acoustic cues
(either conspecific or adventitious). For
more detail on these concepts see, e.g.,
Barber et al., 2010; Pijanowski et al.
2011; Francis and Barber 2013; Lillis et
al. 2014.
Beluga foraging habitat is limited at
the POA given the highly industrialized
area. However, foraging habitat exists
near the POA, including Ship Creek and
to the north of Cairn Point. Potential
impacts to foraging habitat include
increased turbidity and elevation in
noise levels during pile driving. Because
the POA is replacing an existing
terminal, permanent impacts from the
presence of structures is negligible.
Here, we focus on construction impacts
such as increased turbidity and
reference the section on acoustic habitat
impacts above.
Pile installation may temporarily
increase turbidity resulting from
suspended sediments. Any increases
would be temporary, localized, and
minimal. POA must comply with state
water quality standards during these
operations by limiting the extent of
turbidity to the immediate project area.
In general, turbidity associated with pile
installation is localized to about a 25foot (7.6 m) radius around the pile
(Everitt et al. 1980). Cetaceans are not
expected to be close enough to the
project activity areas to experience
effects of turbidity, and any small
cetaceans and pinnipeds could avoid
localized areas of turbidity. Therefore,
the impact from increased turbidity
levels is expected to be discountable to
marine mammals. No impacts to Ship
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72171
Creek or critical CIBW foraging habitats
are anticipated.
In summary, activities associated with
the proposed PCT project are not likely
to have a permanent, adverse effect on
marine mammal habitat or populations
of fish species or on the quality of
acoustic habitat. Marine mammals may
choose to not forage in close proximity
to the PCT site during pile driving;
however, the POA is not a critical
foraging location for any marine
mammal species. As discussed above,
harbor seals primarily use Ship Creek as
foraging habitat within Knik Arm.
Beluga whales utilize Eagle Bay and
rivers north of the POA which are not
expected to be ensonified by the PCT
project. Therefore, no impacts to critical
foraging grounds are anticipated.
Estimated Take
This section provides an estimate of
the number of incidental takes proposed
for authorization through this IHA,
which will inform both NMFS’
consideration of ‘‘small numbers’’ and
the negligible impact determination.
Harassment is the only type of take
expected to result from these activities.
Except with respect to certain activities
not pertinent here, section 3(18) of the
MMPA defines ‘‘harassment’’ as any act
of pursuit, torment, or annoyance,
which (i) has the potential to injure a
marine mammal or marine mammal
stock in the wild (Level A harassment);
or (ii) has the potential to disturb a
marine mammal or marine mammal
stock in the wild by causing disruption
of behavioral patterns, including, but
not limited to, migration, breathing,
nursing, breeding, feeding, or sheltering
(Level B harassment).
Authorized takes would primarily be
by Level B harassment, as pile driving
has the potential to result in disruption
of behavioral patterns for individual
marine mammals. There is also some
potential for auditory injury (Level A
harassment) to result, primarily for
mysticetes, high frequency species, and
phocids because predicted auditory
injury zones are larger than for midfrequency species and otariids. Auditory
injury is unlikely to occur for midfrequency species and otariids. The
proposed mitigation and monitoring
measures are expected to minimize the
severity of such taking to the extent
practicable.
As described previously, no mortality
is anticipated or proposed to be
authorized for this activity. Below we
describe how the take is estimated.
Generally speaking, we estimate take
by considering: (1) Acoustic thresholds
above which NMFS believes the best
available science indicates marine
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mammals will be behaviorally harassed
or incur some degree of permanent
hearing impairment; (2) the area or
volume of water that will be ensonified
above these levels in a day; (3) the
density or occurrence of marine
mammals within these ensonified areas;
and, (4) and the number of days of
activities. We note that while these
basic factors can contribute to a basic
calculation to provide an initial
prediction of takes, additional
information that can qualitatively
inform take estimates is also sometimes
available (e.g., previous monitoring
results or average group size). Below, we
describe the factors considered here in
more detail and present the proposed
take estimate.
Acoustic Thresholds
Using the best available science,
NMFS has developed acoustic
thresholds that identify the received
level of underwater sound above which
exposed marine mammals would be
reasonably expected to be behaviorally
harassed (equated to Level B
harassment) or to incur PTS of some
degree (equated to Level A harassment).
Level B harassment for non-explosive
sources—Though significantly driven by
received level, the onset of behavioral
disturbance from anthropogenic noise
exposure is also informed to varying
degrees by other factors related to the
source (e.g., frequency, predictability,
duty cycle), the environment (e.g.,
bathymetry), and the receiving animals
(hearing, motivation, experience,
demography, behavioral context) and
can be difficult to predict (Southall et
al., 2007, Ellison et al., 2012). Based on
what the available science indicates and
the practical need to use a threshold
based on a factor that is both predictable
and measurable for most activities,
NMFS uses a generalized acoustic
threshold based on received level to
estimate the onset of behavioral
harassment. In general, 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 mPa (rms) for continuous (e.g.,
vibratory pile-driving, drilling) and
above 160 dB re 1 mPa (rms) for nonexplosive impulsive (e.g., seismic
airguns) or intermittent (e.g., scientific
sonar) sources. However, ambient noise
levels within Knik Arm are above the
120-dB threshold, and therefore, for
purposes of this analysis, NMFS
considers received levels above those of
the measured ambient noise (122.2 dB)
to constitute Level B harassment of
marine mammals incidental to
continuous noise, including vibratory
pile driving.
Results from the most recent acoustic
monitoring conducted at the port are
presented in Austin et al. (2016) and
Denes et al. (2016) wherein noise levels
were measured in absence of pile
driving from May 27 through May 30,
2016 at two locations: Ambient-Dock
and Ambient-Offshore. NMFS considers
the median sound levels to be most
appropriate when considering
background noise levels for purposes of
evaluating the potential impacts of the
POA’s PCT Project on marine mammals.
By using median value, which is the
50th percentile of the measurements, for
ambient noise level, one will be able to
eliminate the few transient loud
identifiable events that do not represent
the true ambient condition of the area.
This is relevant because during two of
the four days (50 percent) when
background measurement data were
being collected, the U.S. Army Corps of
Engineers was dredging Terminal 3
(located just north of the AmbientOffshore hydrophone) for 24 hours per
day with two 1-hour breaks for crew
change. On the last two days of data
collection, no dredging was occurring.
Therefore, the median provides a better
representation of background noise
levels when the PCT project would be
occurring. With regard to spatial
considerations of the measurements, the
Ambient-Offshore location is most
applicable to this discussion as it is
complies with the NMFS 2012 memo
discussed above. The median ambient
noise level collected over four days at
the end of May at the Ambient-Offshore
hydrophone was 122.2 dB. We note the
Ambient-Dock location was quieter,
with a median of 117 dB; however, that
hydrophone was placed very close to
the dock and not where we would
expect Level B harassment to occur
given mitigation measures (e.g., shut
downs). If additional data collected in
the future warrant revisiting this issue,
NMFS may adjust the 122.2 dB rms
Level B harassment threshold.
Level A harassment for non-explosive
sources—NMFS’ Technical Guidance
for Assessing the Effects of
Anthropogenic Sound on Marine
Mammal Hearing (Version 2.0)
(Technical Guidance, 2018) identifies
dual criteria to assess auditory injury
(Level A harassment) to five different
marine mammal groups (based on
hearing sensitivity) as a result of
exposure to noise from two different
types of sources (impulsive or nonimpulsive). The POA’s proposed
activity includes the use of impulsive
(impact pile driving) and non-impulsive
(vibratory pile driving) sources.
These thresholds are provided in
Table 5 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-technicalguidance.
TABLE 5—THRESHOLDS IDENTIFYING THE ONSET OF PERMANENT THRESHOLD SHIFT
PTS onset acoustic thresholds *
(received level)
Hearing group
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Impulsive
Low-Frequency (LF) Cetaceans ......................................
Mid-Frequency (MF) Cetaceans ......................................
High-Frequency (HF) Cetaceans .....................................
Phocid Pinnipeds (PW) (Underwater) .............................
Otariid Pinnipeds (OW) (Underwater) .............................
Lpk,flat:
Lpk,flat:
Lpk,flat:
Lpk,flat:
Lpk,flat:
219
230
202
218
232
dB;
dB;
dB;
dB;
dB;
Non-impulsive
LE,LF,24h: 183 dB ....................................
LE,MF,24h: 185 dB ....................................
LE,HF,24h: 155 dB ....................................
LE,PW,24h: 185 dB ...................................
LE,OW,24h: 203 dB ...................................
LE,LF,24h: 199 dB.
LE,MF,24h: 198 dB.
LE,HF,24h: 173 dB.
LE,PW,24h: 201 dB.
LE,OW,24h: 219 dB.
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level thresholds associated with impulsive sounds, these thresholds should
also be considered.
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72173
Note: Peak sound pressure (Lpk) has a reference value of 1 μPa, and cumulative sound exposure level (LE) has a reference value of 1μPa2s.
In this Table, thresholds are abbreviated to reflect American National Standards Institute standards (ANSI 2013). However, peak sound pressure
is defined by ANSI as incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ‘‘flat’’ is being
included to indicate peak sound pressure should be flat weighted or unweighted within the generalized hearing range. The subscript associated
with cumulative sound exposure level thresholds indicates the designated marine mammal auditory weighting function (LF, MF, and HF
cetaceans, and PW and OW pinnipeds) and that the recommended accumulation period is 24 hours. The cumulative sound exposure level
thresholds could be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it is valuable for
action proponents to indicate the conditions under which these acoustic thresholds will be exceeded.
Ensonified Area
Here, we describe operational and
environmental parameters of the activity
that will feed into identifying the area
ensonified above the acoustic
thresholds, which include source levels
and transmission loss coefficient.
The estimated sound source levels
and transmission loss coefficient used
in our analysis are based on direct
measurements during installation of
unattenuated 48-in piles during the
POA’s 2016 TPP and measurements
collected during marine construction
projects conducted by the U.S. Navy.
All source levels used in our analysis
are presented in Table 6.
TABLE 6—ESTIMATED SOUND SOURCE LEVEL WITH AND WITHOUT A BUBBLE CURTAIN
Sound Level at 10 m
Method and pile
size
Unattenuated 1
Bubble curtain
Vibratory
db rms
7 dB reduction, dB rms
144-in ....................
48-in ......................
36-in ......................
24-in ......................
178
168
166
161
171
161
159
154
Unattenuated 1
Bubble curtain
Impact
dB rms
144-in ....................
48-in ......................
36-in ......................
24-in ......................
dB SEL
209
200
194
193
dB peak
198
187
184
181
dB rms
220
215
211
210
Data source
Caltrans 2015.
Austin et al. 2016
Navy 2015.
Navy 2015.
dB SEL
202
193
187
186
dB peak
191
180
177
174
213
208
204
203
Caltrans 2015.
Austin et al. 2016.
Navy 2015.
Navy 2015.
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1 We note the only piles that may be driven or removed without a bubble curtain are 24-in battered piles. We included unattenuated SLs here
for 36-in, 48-in, and 144-in piles to demonstrate how the 7dB reduction for bubble curtains was applied.
During the TPP, JASCO computed
transmission loss (TL) coefficients,
derived from fits of the received sound
level data versus range. TL coefficients
varied between piles with values
ranging from 13 to 19.2 for impact pile
driving and from 12.6 to 17.9 for
vibratory pile driving when using sound
attenuation devices. Results for the
unattenuated hydraulic impact hammer
yielded the highest TL coefficient, 19.2,
indicating that sounds from the
hydraulic impact hammer decayed most
rapidly with range compared to the
other hammers. The TL coefficient for
the unattenuated diesel impact hammer
averaged 17.5. Sounds from the
unattenuated vibratory hammer had the
lowest TL coefficient, with values of
16.1 and 16.9.
Based on these data, the POA
proposed different transmission loss
rates depending on if SEL (used for
Level A harassment) or rms (used for
Level B harassment) values were being
evaluated. SPLrms is a pressure metric
and SEL an energy metric. The
difference in TL coefficient is a
reflection of how SPLrms or SEL is
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dissipated in the marine environment.
During underwater sound propagation,
pressure amplitude tends to suffer more
loss due to multipath propagation and
reverberation, while acoustic energy
does not dissipate as rapidly.
Accordingly, the POA proposed using
TL rate of 16.85 for assessing potential
for Level A harassment from impact pile
driving but a TL rate of 18.35, based on
Austin et al. (2016), when assessing
potential for Level B harassment from
impact pile driving. For vibratory pile
driving, SPLrms is used for both Level
A harassment and Level B harassment
analysis and, based on Austin et al.
(2016), the POA applied a TL rate of
16.5. NMFS found these transmission
loss rates acceptable and carried them
forward in our analysis.
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
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with marine mammal density or
occurrence to help predict takes. We
note that because of some of the
assumptions included in the methods
used for these tools, we anticipate that
isopleths produced are typically going
to be overestimates of some degree,
which may result in some degree of
overestimate of Level A harassment
take. However, these tools offer the best
way to predict appropriate isopleths
when more sophisticated 3D modeling
methods are not available, and NMFS
continues to develop ways to
quantitatively refine these tools, and
will qualitatively address the output
where appropriate. For stationary
sources (such as pile driving), 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.
The User Spreadsheet also includes a
default, single frequency weighting
factor adjustment (WFA) to account for
frequency hearing groups. During the
2016 TPP, the POA collected direct
measurements of sound generated
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during installation of 48-in piles. The
spectra associated with impact and
vibratory driving 48-in unattenuated
piles was also derived. Therefore, we
accepted POA’s applied spectra
approach for 48-in piles but relied on
the User Spreadsheet default WFA for
all other pile sizes.
Inputs used in the User Spreadsheet
for 24-in, 36-in and 144-in piles, and the
resulting isopleths are reported in Table
7.
TABLE 7—NMFS USER SPREADSHEET INPUTS
24-in
(unattenuated)
24-in
(bubble curtain)
36-in
(bubble curtain)
48-in
(bubble curtain)
144-in
(bubble curtain)
(E.1) Impact pile
driving
(E.1) Impact pile
driving
(E.1) Impact pile
driving
(E.1) Impact pile
driving
(E.1) Impact pile
driving
Spreadsheet Tab Used
User Spreadsheet Input: Impact Pile Driving (TL = 16.85)
Source Level (Single Strike/shot SEL) .........
Weighting Factor Adjustment (kHz) ..............
Number of strikes pile ...................................
Piles per day .................................................
181 ............................
2 ................................
100 ............................
5 ................................
174 ............................
2 ................................
100 ............................
5 ................................
177 ............................
2 ................................
3,000 .........................
1–3 ............................
180 ............................
measured spectra .....
2,300 or 3,000 ..........
1–3 ............................
191
2
5,000
0.3 or 0.7
User Spreadsheet Input: Vibratory Pile Driving (TL = 16.5)
Spreadsheet Tab Used
(A) Non-Impul, Stat,
Cont.
(A) Non-Impul, Stat,
Cont.
(A) Non-Impul, Stat,
Cont.
(A) Non-Impul, Stat,
Cont.
Source Level (SPL RMS) ..............................
Weighting Factor Adjustment (kHz) ..............
Time to drive single pile (minutes) ................
Piles per day .................................................
161 ............................
2.5 .............................
75 ..............................
1–5 ............................
154 ............................
2.5 .............................
100 ............................
1–3 ............................
159 ............................
2.5 .............................
75 ..............................
1–3 ............................
171 ............................
measured spectra .....
30 ..............................
1 ................................
To calculate the Level B harassment
isopleths, NMFS considered SPLrms
source levels and the corresponding TL
coefficients of 18.35 and 16.5 for impact
and vibratory pile driving, respectively.
The resulting Level A harassment and
(A) Non-Impul, Stat,
Cont.
171
2.5
45
1
Level B harassment isopleths are
presented in Table 8.
TABLE 8—DISTANCES TO LEVEL A HARASSMENT, BY HEARING GROUP, AND LEVEL B HARASSMENT THRESHOLDS PER
PILE TYPE AND INSTALLATION METHOD
Pile size
48-in (2,300 strikes per
pile).
48-in (3,000 strikes per
pile).
48-in ..............................
36-in ..............................
24-in ..............................
Hammer
type
Impact .......
Impact .......
Attenuation
khammond on DSKJM1Z7X2PROD with NOTICES2
PW
OW
34
766
376
36
629
Bubble Curtain .....
2
3
1
989
1258
767
51
65
39
1156
1470
897
567
721
440
55
70
43
....................
....................
629
2
3
1
3
4
1
2
3
3
4
3
4
5
5
0.3
0.7
1
1158
1473
5
12
14
509
768
978
3
7
9
19
77
304
2286
3781
24
59
76
1
1
2
26
39
50
0
1
1
2
4
16
117
194
3
1353
1721
7
17
20
595
898
1142
5
10
13
27
90
355
2672
4418
34
664
844
3
8
9
292
440
560
2
4
6
12
44
174
1311
2167
15
64
82
0
1
1
28
43
54
0
0
1
1
4
17
127
210
1
....................
....................
2,247
1,699
....................
296
....................
....................
846
....................
2,247
....................
261
629
1,945
1,945
9,069
Bubble Curtain .....
Bubble Curtain .....
Impact .......
Bubble Curtain .....
Vibratory ...
Bubble Curtain .....
Impact .......
Bubble Curtain .....
Unattenuated .......
Bubble Curtain .....
Vibratory ...
..............................
In this section we provide the
information about the presence, density,
or group dynamics of marine mammals
and present take calculations.
For all species of cetaceans other than
beluga whales, density data is not
20:13 Dec 27, 2019
HF
655
Marine Mammal Occurrence and Take
Estimation
VerDate Sep<11>2014
MF
1
Unattenuated .......
144-in ............................
LF
Level B
harassment
(m)
Bubble Curtain .....
Vibratory ...
Vibratory ...
Impact .......
Level A harassment
(m)
Piles
installed/
day
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available for upper Cook Inlet.
Therefore, the POA relied on marine
mammal monitoring data collected
during past POA projects. These data
cover the construction season (April
through November) across multiple
years. Estimated exposure from pile
installation for all marine mammals
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except beluga whales is calculated by
the following equation: Exposure
estimate = N * # days of pile
installation, where: N = highest daily
abundance estimate for each species in
project area across all years of data.
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Harbor Seals
khammond on DSKJM1Z7X2PROD with NOTICES2
Marine mammal monitoring data
collected during from previous POA
projects were used to estimate daily
sighting rates for harbor seals in the
project area. The highest individual
sighting rate recorded for a previous
year was used to quantify take of harbor
seals for pile installation associated
with the PCT. The number of sightings
of harbor seals during 2016 TPP
construction monitoring was 28
sightings recorded over 83.5 hours of
monitoring from May 3 through June 21,
2016. Based on these observations, the
sighting rate during the 2016 TPP
construction monitoring period was one
harbor seal every 3 hours, or
approximately four harbor seals per 12hour work day. Given projected positive
population growth, it is anticipated that
eight harbor seals may be observed, and
potentially exposed to noise, per 12hour work day.
Pile installation and removal is
anticipated to take approximately 127
days for Phase 1 and 75 days for Phase
2. Therefore, we estimate that no more
than 1,016 harbor seals during Phase 1
(8 harbor seals per day * 127 days) plus
600 harbor seals (8 harbor seals per day
* 75 days) during Phase 2, for a total of
1,616 harbor seals, would be potentially
exposed to in-water noise levels
exceeding the Level B harassment
thresholds for pile installation/removal
during PCT construction.
The mouth of Ship Creek, where
harbor seals tend to concentrate is
located approximately 700 m from the
southern end of the PCT, and is
therefore located outside the harbor
seals Level A zone for the majority of
pile sizes for both impact and vibratory
pile installation. However, there is
potential for Level A harassment near
Ship Creek during installation of three
48-in piles per day and installation of
144-in piles. We estimate 30 percent of
the Level B exposures could result in
Level A harassment which is similar to
the proportion of work where the Level
A harassment isopleth extend to Ship
Creek. Therefore, the POA has
requested, and NMFS proposes to
authorize 305 Level A harassment and
711 Level B harassment takes in Phase
1 and 180 Level A harassment and 420
Level B harassment takes in Phase 2.
Steller Sea Lions
Steller sea lions are anticipated to be
encountered in low numbers, if at all,
within the project area. Three sightings
of what was likely a single individual
occurred in the project area in 2009 and
two sightings occurred in 2016. Based
on observations in 2016, we anticipate
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an exposure rate of 2 individuals every
19 days during PCT pile installation and
removal. Based on this rate, the POA
requested 13 sea lions takes during
Phase 1 (127 days * [2 sea lions every
19 days]) and 8 Steller sea lion takes
during Phase 2 (75 days for Phase 2 *
[2 sea lions every 19 days]). During
installation of 144-in piles (Phase 2), the
Level A harassment isopleth extends
beyond 100 m. Although Steller sea
lions are readily detectable at these
distances, we are not proposing the POA
be required to shut down if a Steller sea
lion is observed. Steller sea lions are
rarely present in Knik Arm; however,
they can linger in the area for multiple
days. During Phase 1, the Level A
harassment isopleth is less than the 100
m shutdown zone for all scenarios;
therefore, the potential for Level A take
is negligible. During installation of the
144-in piles in Phase 2, there is a low
potential for Level A harassment and an
animal may remain for a couple days;
therefore, we allocate two takes in Phase
2 to Level A harassment.
Harbor Porpoise
Previous monitoring data at the POA
were used to evaluate daily sighting
rates for harbor porpoises in the project
area. During most years of monitoring,
no harbor porpoises were observed. The
highest individual sighting rate for any
recorded year during pile installation
and removal associated with the PCT
was an average of 0.09 harbor porpoises
per day during 2009 construction
monitoring, but this value may not
account for increased sightings in Upper
Cook Inlet (Shelden et al. 2014).
Therefore, the POA assumed that one
harbor porpoise could be observed every
2 days of pile driving. Based on this
assumption, the POA has requested, and
NMFS is proposing to authorize, 64
exposures during Phase 1 (127 days * [1
harbor porpoise every 2 days]) and 38
harbor porpoises during Phase 2 (75
days for Phase 2 * [1 harbor porpoise
every 2 days]). This estimate also covers
the possibility that larger groups (2–3
individuals) of harbor porpoise could
occur occasionally.
Harbor porpoises are relatively small
cetaceans that move at high velocities,
which can make their detection and
identification at great distances difficult.
Using the NMFS User Spreadsheet,
impact driving 36-in, 48-in and 144-in
piles results in Level A harassment
isopleths larger than the Level B
harassment isopleth. Vibratory driving
and removal result in much smaller
Level B harassment zone than Level B
harassment zones and many temporary
piles (the bulk of the work) would be
installed and removed with a vibratory
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hammer. Further, the Level A
harassment isopleths consider long
durations and harbor porpoise are likely
moving through the area, if present, not
lingering. Therefore, we propose to
authorize approximately one-third of
the expected take to Level A
harassment. For Phase 1, we are
proposing to authorize 21 takes by Level
A harassment and 43 takes by Level B
harassment. For Phase 2, we propose to
authorize 13 Level A harassment and 25
Level B harassment takes.
Killer Whales
Few, if any, killer whales are expected
to approach the project area. No killer
whales were sighted during previous
monitoring programs for the Knik Arm
Crossing and POA construction projects,
including the 2016 TPP. The infrequent
sightings of killer whales that are
reported in upper Cook Inlet tend to
occur when their primary prey
(anadromous fish for resident killer
whales and beluga whales for transient
killer whales) are also in the area
(Shelden et al. 2003). Previous sightings
of transient killer whales have
documented pod sizes in upper Cook
Inlet between one and six individuals
(Shelden et al. 2003). The potential for
exposure of killer whales within the
Level B harassment isopleths is
anticipated to be extremely low. Level B
take is conservatively estimated at no
more than 12 individuals during Phase
1 and Phase 2 to account for two large
(n = 12) groups or several smaller
groups. No Level A harassment take for
killer whales is anticipated or proposed
to be authorized due to the small Level
A harassment zones and
implementation of a 100 m shutdown
which is larger than Level A harassment
isopleths.
Humpback Whales
Sightings of humpback whales in the
project area are rare, and the potential
risk of exposure of a humpback whale
to sounds exceeding the Level B
harassment threshold is low. Few, if
any, humpback whales are expected to
approach the project area. However,
there were two sightings in 2017 of what
was likely a single individual at the
Ship Creek Boat Launch (ABR 2017)
which is located south of the project
area. Based on these data, the POA
conservatively estimates one humpback
whale could be harassed every 16 days
of pile driving. Therefore, the POA
requested 8 humpback whale takes
during Phase 1 (127 days for Phase 1 *
[1 humpback whale every 16 days]) and
5 takes (75 days for Phase 2 * [1
humpback whale every 16 days]) for
Phase 2. This could include sighting a
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cow-calf pair on multiple days or
multiple sightings of single humpback
whales. The POA did not request Level
A take of humpback whales; however,
based on the distances to the large Level
A harassment thresholds relative to
Level B harassment isoplehts and the
fact humback whale sightings in Upper
Cook Inlet is rare, NMFS is proposing to
issue two Level A harassment takes per
year to account for a single individual
or a cow/calf pair. Therefore, NMFS is
proposing to issue two Level A
harassment takes and six Level B
harassment takes during Phase 1 and
two Level A harassment takes and three
Level B harassment takes for Phase 2.
Beluga Whales
For beluga whales, we looked at
several sources of information on
marine mammal occurrence in upper
Cook Inlet to determine how best to
estimate the potential for exposure to
pile driving noise from the PCT Project.
In their application, the POA took a
two-step approach to estimating Level B
harassment take. The POA first
estimated the numbers of beluga whales
potentially exposed to noise levels
above the Level B harassment threshold
for pile installation and removal using
the following formula: Beluga Exposure
Estimate = N * Area * number of days
of pile installation/removal, where: N =
maximum predicted # of beluga whales/
km2 in Knik Arm (0.291 whales/km2)
based on data from Goetz et al. (2012a)
and Area = Area ensonified above Level
B harassment threshold (km2). We note
the actual beluga whale densities within
the Level B harassment isopleths
predicted for the PCT project ranged
from 0.042 to 0.236 beluga whales/km2.
However, the POA applied the highest
beluga whale density in upper Knik
Arm. The higher densities north of the
POA are expected as beluga whales tend
to concentrate in Eagle Bay to forage
whereas in the lower Arm, where the
POA is located, habitat use is more
commonly associated with traveling.
The POA’s simple calculation results in
103 takes in Phase 1 and 125 takes in
Phase 2. The second step in POA’s take
estimate approach was to apply a 50
percent correction factor to their
density-based calculation. The POA
provided several reasons why this
reduction factor was appropriate,
including, but not limited to: The POA’s
commitment to using a bubble curtain
means that noise levels along the
western side of Knik Arm will remain
below the regulatory thresholds;
providing a travel corridor for beluga
whales to access upper Knik Arm; for
the majority of PCT construction and
pile installation and removal, only
approximately half of the width of Knik
Arm, along the eastern shore, would be
ensonified; beluga whales observed in
Knik Arm during the autumn were most
frequently sighted on the western side
of the arm (Funk et al. 2005); and beluga
whales in Knik Arm year-round;
however, sightings are much lower in
winter through early summer.
We reviewed the POA’s density-based
take calculation approach and their
reasons for applying a 50 percent
correction factor. We determined use of
the Goetz density data for this specific
project is problematic because the
density data is based on June aerial
surveys while the PCT project is
occurring from April through
November, the data is over seven years
old, and the multiple years of
monitoring data collected by the POA is
not incorporated into this approach.
Regarding the rationale for applying a
50 percent correction factor, we found
the use of a bubble curtain and the fact
the majority of pile driving would
ensonify half or less than half of the
width of Knik Arm is already captured
by the ensonsified area which is
embedded into the take calculation. The
POA is not pile driving during winter
when beluga whale abundance is lowest
and although early summer tends to see
lower beluga abundance, the density
used in the take calculation is from June
surveys. Finally, any habituation to
repeated exposure may be considered
qualitatively in analyzing the intensity
of reactions to pile driving but it cannot
be quantified and is not considered in
take estimates.
To better capture beluga whale
distribution and abundance, we
undertook a multi-step analysis
consisting of an evaluation of long-term,
seasonal sighting data, proposed
mitigation and monitoring measures, the
amount of documented take from
previous POA projects compared to
authorized take, and considered group
size. First, in lieu of density data, NMFS
applied sighting rate data presented in
Kendell and Cornick (2015) to estimate
hourly sighting rates per month (April
through November). We then identified
hours of pile driving per month. The
POA indicated there will be extended
durations when no pile driving is
happening (e.g., later in the season
when decking and other out-of-water
work is occurring); however, the
schedule could not be more refined than
assuming an equal work distribution
across the construction season. The
POA did indicate the first two weeks of
April and the last two weeks in
November would be most likely utilized
for equipment mobilization and
demobilization; therefore, pile driving
effort during those months were limited
to two weeks. The data and calculated
exposure estimates are presented below.
These calculations assume no mitigation
(i.e., uncorrected take estimates) and
that all animals observed would enter a
given Level B harassment zone during
pile driving. In total, we would expect
approximately 94 exposures in Phase 1
and 60 exposures in Phase 2.
TABLE 9—UNCORRECTED BELUGA WHALE EXPOSURE ESTIMATES FOR PHASE 1 AND PHASE 2
Monitoring data 1
Month
Number of
whales
observed
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Effort hours
Estimated instances of take
Pile driving
hours
Phase 1 2
Average
whale/hr
CIBW
exposures
Phase 1
Pile driving
hours
Phase 2 2
CIBW
exposures
Phase 2
April ...............................................................
May ................................................................
June ...............................................................
July ................................................................
August ...........................................................
Sept ...............................................................
October ..........................................................
Nov ................................................................
12
156
280
360
426
447
433
215
2
40
8
2
269
169
22
175
0.17
0.26
0.03
0.01
0.63
0.38
0.05
0.82
25.64
51.29
51.29
51.29
51.29
51.29
51.29
25.64
4.27
13.15
1.47
0.28
32.38
19.37
2.61
20.91
16.37
32.71
32.71
32.71
32.71
32.71
32.71
16.37
2.73
8.39
0.94
0.18
20.65
12.35
1.66
13.35
Total .......................................................
2317
685
0.30
359.02
94.44
229.00
60.25
1 From
Kendell and Cornick 2015.
2 Assumes equal work distribution/month except in April and November when the POA has indicated they would be conducting only 2 weeks of pile driving due to
time needed for mobilization and demobilization.
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Second, NMFS then considered the
proposed mitigation and distribution of
beluga whales in Knik Arm. In the
POA’s application, they proposed a 100m shutdown zone. However, as
described in more detail below, NMFS
has imposed additional mitigation
designed to reduce Level B harassment
take as well as Level A harassment take.
We recognize that in certain situations,
pile driving may not be able to be
shutdown prior to whales entering the
Level B harassment zone due to safety
concerns. Sometimes beluga whales
were initially observed when they
surfaced within the harassment zone.
For example, on November 4, 2009, 15
whales were initially sighted
approximately 950 meters north of the
project site near the shore, and then
they surfaced in the Level B harassment
zone during vibratory pile driving (ICRC
2009b). Construction activities were
immediately shut down, but the 15
whales were documented as takes. On
other occasions, beluga whales were
initially sighted outside of the
harassment zone and shut down was
called, but the beluga whales swam into
the harassment zone before activities
could be halted, and take occurred. For
example, on September 14, 2009, a
construction observer sighted a white
beluga whale just outside the
harassment zone, moving quickly
towards the 1,300 meter Level B
harassment zone during vibratory pile
driving. The animal entered the
harassment zone before construction
activity could be shut down, and was
documented as a take (ICRC 2009c).
To more accurately estimate potential
exposures, we looked at previous takes
at the POA and those actually
authorized. Between 2008 and 2012,
NMFS authorized 34 beluga whale takes
per year to POA with mitigation
measures similar to the measures
proposed here. The percent of the
authorized takes that were documented
as actually occurring during this time
period ranged from 12 to 59 percent
with an average of 36 percent (Table 10).
The previous method of estimating take
was based on density; however, the
results between using densities versus
sighting rate are somewhat comparable
(e.g., 94 exposures in Phase 1 using
sighting rates versus 103 exposures
using density). Further, there was
extensive scientific monitoring and POA
construction monitoring occurring
during these time periods; therefore, we
believe there is little potential animals
were taken but not observed. Therefore
we believe this first step in our analysis
is reasonable.
TABLE 10—AUTHORIZED AND REPORTED BELUGA WHALE TAKES DURING POA ACTIVITIES FROM 2009–2012
Reported
takes
15
15
15
15
July
July
July
July
2008–14
2009–14
2010–14
2011–14
July
July
July
July
2009
2010
2011
2012
.........................................................................................................
.........................................................................................................
.........................................................................................................
.........................................................................................................
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Second, we applied the highest
percentage of previous takes to ensure
potential impacts to beluga whales are
fully evaluated and to ensure the POA
has an adequate amount of take.
Therefore, we assume that
approximately 59 percent of the takes
calculated for Phase 1 (n=94) and Phase
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20:13 Dec 27, 2019
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2 (n=64) will actually be realized. This
approach is further supported by the
proposed mitigation measures which are
strict shutdown requirements for CIBWs
with a goal of avoiding Level B take
altogether, similar to previous POA
mitigation measures.
Finally, we then considered group
size from the long-term scientific
PO 00000
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Authorized
take
12
20
13
4
34
34
34
34
Percent of
authorized
takes occurred
35
59
38
12
monitoring effort and POA
opportunistic data to determine if these
numbers represented realistic scenarios.
Figure 2 presents data from the
scientific monitoring program. The APU
scientific monitoring data set
documented 390 beluga whale sightings.
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Group size exhibits a mode of 1 and
a median of 2, indicating that over half
of the beluga groups observed over the
5-year span of the monitoring program
were of individual beluga whales or
groups of 2. The 95th percentile of
group size from the APU scientific
monitoring data set is 11.1 beluga
whales. This means that, of the 390
documented beluga whale groups in this
data set, 95 percent consisted of fewer
than 11.1 whales; 5 percent of the
groups consisted of more than 11.1
whales. We conclude the amount of take
proposed to be authorized following the
approach above allows for the potential
for large groups to be exposed to noise
above NMFS harassment thresholds.
For reasons described above, NMFS
believes this approach adequately
analyzes the risk of beluga whale
exposure to Level B harassment from
the PCT Project. We conclude there is
the potential for 45 exposures in Phase
1 and 33 exposures in Phase 2 (Table
11).
TABLE 11—PROPOSED BELUGA WHALE LEVEL B HARASSMENT EXPOSURES
Calculated
exposure
PCT construction phase
Phase 1—2020 ............................................................................................................................................
Phase 2—2021 ............................................................................................................................................
1 Proposed
Proposed
take 1
94
60
55
35
take is identified as 59 percent of the calculated exposures using sighting rates.
In summary, the total amount of Level
A harassment and Level B harassment
proposed to be authorized for each
marine mammal stock is presented in
Table 12.
TABLE 12—PROPOSED AMOUNT OF TAKE, BY STOCK AND HARASSMENT TYPE
Phase 1 (2020)
Species
Stock
Level A
Humpback whale ..
Beluga whale ........
Killer whale ...........
Harbor porpoise ....
Steller sea lion ......
Harbor seal ...........
Western N Pacific
Cook Inlet .............
Transient/Alaska
Resident.
Gulf of Alaska .......
Western ................
Cook Inlet/Shelikof
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Proposed Mitigation
In order to issue an IHA under
Section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible
methods of taking pursuant to such
activity, and other means of effecting
the least practicable impact on such
species or stock and its habitat, paying
particular attention to rookeries, mating
grounds, and areas of similar
significance, and on the availability of
such species or stock for taking for
certain subsistence uses. 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:
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Phase 2 (2021)
Percent of
stock
Level B
Percent of
stock
Level B
2
0
0
6
55
12
0.7
17
2
2
0
0
4
35
12
0.7
11
2
21
0
305
43
13
711
0.2
<0.1
3.6
13
2
180
25
6
420
0.2
<0.1
2.1
(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 POA presented a number of
mitigation measures in section 11 of
their application. NMFS accepted a
number of these measures (e.g., use of
bubble curtains on all plumb piles) but
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also requested the POA consider
additional noise attenuation measures
and modified shut down zones, among
other things. We present mitigation
measures NMFS has determined to
affect the least practicable adverse
impact on marine mammals and their
habitat followed by a discussion of the
ongoing considerations by NMFS and
the POA which will be made final prior
to issuance of the final IHA.
A key mitigation measure NMFS
considered for this project is reducing
noise levels propagating into the
environment. The POA will use a
bubble curtain on all plumb piles. At
this time, NMFS is not requiring an
unconfined bubble curtain. The POA
presented a Technical Manual on the
analysis of water current velocity data
collected in the vicinity of the proposed
PCT (TerraSound 2016) demonstrating
current speeds were approximately 3
knots (kts) during times when tides
were strongest. The POA has not
finalized the bubble curtain design;
however, bubble ring placement and
bubble sizes and spacing must combat
the current. In addition, the sound
source verification results (see Proposed
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Monitoring and Reporting Measures
section below) must demonstrate the
bubble curtain is achieving consistent
noise attenuation such that source levels
are at or below those evaluated in this
document during all tide phases. The
bubble curtain will be designed to
absorb as much sound as possible. The
POA proposed, and NMFS is requiring,
all plumb piles installed in-water be
done so in the presence of a fully
operational bubble curtain.
The POA is also currently evaluating
means by which to reduce sound
propagation on battered piles. The POA
has indicated that a full bubble curtain
ring is not possible on battered piles;
however, NMFS has requested the POA
further investigate other means of
reducing noise such as a linear or semicircular curtain around the work area.
The POA is actively looking into this
and final noise attenuation plans will be
made prior to issuance of the IHA. We
note that for purposes of our analysis
here, NMFS did not consider any noise
attenuation during installation of
battered piles. However, we are
requiring that unattenuated piles not be
driven in water depths greater than 3
meters based on the cutoff frequency
(Roger and Cox, 1988). The intent of this
measure is to reduce sound propagation.
In shallower waters, lower frequencies
tend to be cutoff more rapidly than high
frequency sources.
In addition to noise attenuation
devices, NMFS considered the amount
of sound energy entering the aquatic
environment. The installation of 144-in
piles is included in Phase 2 (2021) and
NMFS has determined that given the
extensive Level B harassment zone
generated from this activity, vibratory
driving these large piles during peak
beluga whale season poses an amount of
risk and uncertainty to the degree that
it should be minimized. Therefore,
vibratory driving 144-in piles will not
occur during August. Further, to
minimize the potential for overlapping
sound fields from multiple stressors, the
POA will not simultaneously operate
two vibratory hammers for either pile
installation or removal. This measure is
designed to reduce simultaneous inwater noise exposure. Because impact
hammers will unlikely be dropping at
the same time, and to expedite
construction of the project to minimize
pile driving during peak beluga whale
abundance periods, NMFS is not
proposing to restrict the operation of
two impact hammers at the same time.
We note that harassment zones during
impact pile driving will radiate from
both of the piles being driven, not a
single pile.
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NMFS also considered other means by
which to remove piles since the
majority of piles installed for this
project are temporary (we note the POA
reduced the amount of temporary piles
originally proposed for this project).
NMFS inquired about the potential to
direct pull piles or cut them off at the
mudline; thereby, reducing in-water
noise levels. The POA responded that
the depth at which temporary piles
would be installed and substrate
precludes directly pulling the piles.
Cutting piles at the mudline also
presents navigational (e.g., anchoring)
and safety concerns.
In their IHA application, the POA
proposed a 100-m shutdown zone for all
marine mammals or, where the Level A
harassment zone was deemed to be
greater than 100 m, a shutdown zone
equivalent to the Level A harassment
zone. NMFS found this measure did not
effect the least practicable adverse
impact on marine mammals for several
reasons.
First, except for 48-in piles, the Level
A harassment zones in the application
are based on estimated spectra which
NMFS does not support. Therefore,
NMFS calculated Level A harassment
zones for all piles (except 48-in piles)
using the single frequency, default
weighting factor adjustment provided in
the NMFS User Spreadsheet. As shown
in Table 8, Level A harassment zones for
low-frequency and high frequency
cetaceans and pinnipeds are rather large
when considering multiple piles
installed per day and installation of the
144-in piles. Sighting rates at these
distances, specifically for harbor seals
and porpoise, are unlikely to be good
enough to ensure effective coverage. For
these reasons, NMFS proposes a 100-m
shutdown zone for all marine mammals
(except beluga whales).
For beluga whales, NMFS determined
the proposed shutdown zone of 100 m
or the Level A harassment zone (if
greater than 100 m) was not consistent
with the conservation intentions of the
POA nor what NMFS would consider as
effecting the least practicable adverse
impact based on the proposed project
description and acoustic analysis.
NMFS and the POA entered into
discussions to discuss these opinions
and have determined that measures and
shutdown zones used in previous IHAs
would ensure valuable protection and
conservation of beluga whales. For this
reason, NMFS is proposing the POA
implement the following measures for
CIBWs:
• Prior to the onset of pile driving,
should a beluga whale(s) be observed
within Knik Arm or approaching the
mouth of Knik Arm, pile driving will be
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delayed until the whale moves away
from the POA or is not re-sighted within
30 minutes. If non-beluga whale species
are observed within or likely to enter
the Level B harassment zone prior to
pile driving, the POA may commence
pile driving, recording and reporting
MMPA take that occurs as a result.
• If pile driving has commenced and
a beluga whale is observed within or
likely to enter the Level B harassment
zone, pile driving will shut down and
not re-commence until the whale is out
of and on a path away from the Level
B harassment zone or until no beluga
whale has been observed in the level B
harassment zone for 30 minutes.
• If, during pile driving, PSOs can no
longer effectively monitor all waters
within the Level B harassment zone for
the presence of marine mammals due to
environmental conditions (e.g., fog, rain,
wind), pile driving may continue only
until the current segment of pile is
driven; no additional sections of pile or
additional piles may be driven until
conditions improve such that the Level
B harassment zone can be effectively
monitored. If the Level B harassment
zone cannot be monitored for more than
15 minutes, the entire Level B zone
must be cleared again for 30 minutes
prior to pile driving.
In addition to these measures which
greatly reduce the potential for
harassment to beluga whales and set
shutdown zones that realistically reflect
non-beluga whale detectability, NMFS
is including general mitigation measures
typically included in IHAs:
• PSOs shall begin observing for
marine mammals 30 minutes before pile
driving begins for the day and must
continue for 30 minutes when pile
driving ceases at any time. If pile
driving has ceased for more than 30
minutes within a day, another 30minute pre-pile driving observation
period is required before pile driving
may commence.
• POA must use soft start techniques
when impact pile driving. Soft start
requires contractors to provide an initial
set of three strikes at reduced energy,
followed by a thirty-second waiting
period, then two subsequent reduced
energy strike sets. A soft start must be
implemented at the start of each day’s
impact pile driving and at any time
following cessation of impact pile
driving for a period of thirty minutes or
longer.
• For in-water construction other
than pile driving, the POA must cease
operations or reduce vessel speed to the
minimum level required to maintain
steerage and safe working conditions if
a marine mammal approaches within 10
m of the equipment or vessel.
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• POA is required to conduct
briefings for construction supervisors
and crews, the monitoring team, and
POA staff prior to the start of all pile
driving activity, and when new
personnel join the work, in order to
explain responsibilities, communication
procedures, the marine mammal
monitoring protocol, and operational
procedures.
• If a species for which authorization
has not been granted, or a species for
which authorization has been granted
but the authorized takes are met, is
observed approaching or within the
monitoring zone (Table 8), 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 the 30 minutes
observation time period has elapsed.
Based on our evaluation of the
applicant’s proposed measures, as well
as other measures considered by NMFS,
NMFS has preliminarily determined
that the proposed mitigation measures
provide the means effecting the least
practicable impact on the affected
species or stocks and their habitat,
paying particular attention to rookeries,
mating grounds, and areas of similar
significance and on the availability of
such species or stock for subsistence
uses.
Proposed Monitoring and Reporting
In order to issue an IHA for an
activity, Section 101(a)(5)(D) of the
MMPA states that NMFS must set forth
requirements pertaining to the
monitoring and reporting of such taking.
The MMPA implementing regulations at
50 CFR 216.104 (a)(13) indicate that
requests for authorizations must include
the suggested means of accomplishing
the necessary monitoring and reporting
that will result in increased knowledge
of the species and of the level of taking
or impacts on populations of marine
mammals that are expected to be
present in the proposed action area.
Effective reporting is critical both to
compliance as well as ensuring that the
most value is obtained from the required
monitoring.
Monitoring and reporting
requirements prescribed by NMFS
should contribute to improved
understanding of one or more of the
following:
• Occurrence of marine mammal
species or stocks in the area in which
take is anticipated (e.g., presence,
abundance, distribution, density).
• Nature, scope, or context of likely
marine mammal exposure to potential
stressors/impacts (individual or
cumulative, acute or chronic), through
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better understanding of: (1) Action or
environment (e.g., source
characterization, propagation, ambient
noise); (2) affected species (e.g., life
history, dive patterns); (3) co-occurrence
of marine mammal species with the
action; or (4) biological or behavioral
context of exposure (e.g., age, calving or
feeding areas).
• Individual marine mammal
responses (behavioral or physiological)
to acoustic stressors (acute, chronic, or
cumulative), other stressors, or
cumulative impacts from multiple
stressors.
• How anticipated responses to
stressors impact either: (1) Long-term
fitness and survival of individual
marine mammals; or (2) populations,
species, or stocks.
• Effects on marine mammal habitat
(e.g., marine mammal prey species,
acoustic habitat, or other important
physical components of marine
mammal habitat).
• Mitigation and monitoring
effectiveness.
During the 2016 TPP, observers for
that project ()provided a number of
recommendations to improve marine
mammal monitoring for POA projects.
These recommendations included:
• A minimum of three PSOs at an
observation station is necessary to
prevent fatigue and increase accuracy of
detecting marine mammals, especially
for large-radius zones. When using three
PSOs, one PSO is observing, one PSO is
recording data (and observing when
there are no data to record), and the
third PSO is resting. A fourth PSO
allows the scanning of a 90-degree arc,
instead of a 180-degree arc, increasing
scan intensity and the likelihood of
detecting marine mammals. Thirty to 60
minute rotations work well with this
schedule.
• Communications between the pile
driving/construction contractor and the
PSOs should take place between one
dedicated point of contact, or Lead PSO,
for each shift.
• Each observation station should
employ a pair of 25-power binoculars as
they were superior to the 7- and 10power binoculars at detecting and
identifying marine mammals at greater
distances.
• Electronic data collection methods
should be considered. iPad applications
and other technological advances make
it possible to collect data quickly and
accurately. A theodolite can be plugged
into the device and marine mammal
locations can be calculated on the spot,
minimizing uncertainty. Data can be
downloaded throughout the day to a
database, eliminating the need for data
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entry by hand, and allowing quicker
data assessment.
• Hard copy maps with
pre-established grid-cells and
harassment zones specific to the pile
location being driven were invaluable.
These maps allowed for immediate,
accurate and consistent identification of
marine mammal locations relative to the
harassment zones, regardless of
observation station.
The POA’s IHA application addresses
the majority of these recommendations
in its Marine Mammal Monitoring Plan
(Appendix A in POA’s application) and
NMFS proposes additional measures
here. NMFS is requiring at least three
PSOs (two on-watch and one to record
data) will be positioned at the norther
and southern station while two PSOs
will be on-watch at the PCT (i.e., pile
driving) station. Each station will be
equipped with several pieces of
equipment (see section 2.4 in Appendix
A of POA’s application), including 25x
binoculars and a range finders, as
recommended above. One station will
have a theodolite. PSOs may observe for
no more than 4 hours at time and no
more than 12 hours per day. The POA
will submit all PSO CVs to NMFS prior
to a PSO working on this project. Where
necessary, NMFS may require a
potential PSO shadow an experienced
PSO before working independently.
To improve beluga whale detection,
NMFS has worked with the POA to
include PSO stations in different
locations than the three stations
proposed by the POA, which were all on
POA property. The POA will have three
PSO stations. One PSO station will be
located at the PCT pile driving site. One
station will be at Port Wornzof or a
similar location to maximize beluga
whale detection outside of Knik Arm
and the mouth of Knik Arm. PSOs at
this location will have unencumbered
views of the entrance to Knik Arm and
can provide information on beluga
whale group dynamics (e.g., group size,
demographics, etc) and behavior of
animals approaching Knik Arm in the
absence of and during pile driving. We
have also considered moving a station
from the POA property to Port
MacKenzie for an improved view of
beluga whales moving from north to
south within Knik Arm. However, the
POA is currently investigating if this is
an option with respect to accessibility
(i.e. private property) and personnel
safety. If Port MacKenzie is not an
available option, the third PSO station
will be located toward the north end of
the POA property. The exact placement
of this northern station will be
determined prior to issuing the IHA. We
note the previous station at Cairn Point
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used several years ago is Elemendorf Air
Force Base property and is no longer
accessible.
For both Phase 1 and Phase 2, NMFS
is requiring the POA submit interim
weekly and monthly monitoring reports
during the PCT construction season.
These reports must include a summary
of marine mammal species and
behavioral observations, pile driving
shutdowns or delays, and pile work
completed. A final end-of season report
will be submitted to NMFS within 90
days following pile driving. The report
must include: Dates and times (begin
and end) of all marine mammal
monitoring; a description of daily
construction activities, weather
parameters and water conditions during
each monitoring period; number of
marine mammals observed, by species,
distances and bearings of each marine
mammal observed to the pile being
driven or removed, age and sex class, if
possible; number of individuals of each
species (differentiated by month as
appropriate) detected within the
monitoring zone, and estimates of
number of marine mammals taken, by
species (a correction factor may be
applied); description of mitigation
triggered, and description of attempts to
distinguish between the number of
individual animals taken and the
number of incidences of take. In
addition, any acoustic data and analysis
collected throughout the year will also
be made available to NMFS in the form
of an interim report within 10 days of
data collection and a final report within
60 days. Mean, median, and peak sound
source levels (dB re: 1mPa): cumulative
sound exposure level (SELcum), peak
sound pressure level (SPLpeak), root
mean square sound pressure level
(SPLrms), and single-strike sound
exposure level (SELs-s) will be reported
as well as pile descriptions and acoustic
monitoring methods (e.g., sampling rate,
distance to the hydrophone from the
pile, etc.).
NMFS has also included reporting
requirements for more uncommon
situations. In the unanticipated event
that the specified activity clearly causes
the take of a marine mammal in a
manner prohibited by this IHA, such as
serious injury, or mortality, POA must
immediately cease the specified
activities and report the incident to the
NMFS. In the event POA discovers an
injured or dead marine mammal, and
the lead observer determines that the
cause of the injury or death is unknown
and the death is relatively recent (e.g.,
in less than a moderate state of
decomposition), POA must immediately
report the incident to the Office of
Protected Resources, NMFS, and the
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Alaska Region Stranding Coordinator,
NMFS. In addition, in the event that
POA discovers an injured or dead
marine mammal, and the lead observer
determines that the injury or death is
not associated with or related to the
specified activities (e.g., previously
wounded animal, carcass with moderate
to advanced decomposition, or
scavenger damage), POA must report the
incident to the Office of Protected
Resources, NMFS, and the Alaska
Region Stranding Coordinator, NMFS,
within 24 hours of the discovery.
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., populationlevel effects). An estimate of the number
of takes alone is not enough information
on which to base an impact
determination. In addition to
considering estimates of the number of
marine mammals that might be ‘‘taken’’
through harassment, NMFS considers
other factors, such as the likely nature
of any responses (e.g., intensity,
duration), the context of any responses
(e.g., critical reproductive time or
location, migration), as well as effects
on habitat, and the likely effectiveness
of the mitigation. We also assess the
number, intensity, and context of
estimated takes by evaluating this
information relative to population
status. Consistent with the 1989
preamble for NMFS’s implementing
regulations (54 FR 40338; September 29,
1989), the impacts from other past and
ongoing anthropogenic activities are
incorporated into this analysis via their
impacts on the environmental baseline
(e.g., as reflected in the regulatory status
of the species, population size and
growth rate where known, ongoing
sources of human-caused mortality, or
ambient noise levels).
To avoid repetition, the majority of
our analysis applies to all species listed
in Table 4 except for CIBWs, given that
many of the anticipated effects of this
project on different marine mammal
stocks are expected to be relatively
similar in nature. For CIBWs, there are
meaningful differences in anticipated
individual responses to activities,
impact of expected take on CIBWs), or
impacts on habitat; therefore, we
provide a supplemental analysis for
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CIBWs, independent of the other species
for which we propose to authorize take.
NMFS has identified key factors
which may be employed to assess the
level of analysis necessary to conclude
whether potential impacts associated
with a specified activity should be
considered negligible. These include
(but are not limited to) the type and
magnitude of taking, the amount and
importance of the available habitat for
the species or stock that is affected, the
duration of the anticipated effect to the
species or stock, and the status of the
species or stock. The following factors
support a negligible impact
determination for the affected stocks of
humpback whales, killer whales, harbor
porpoise, harbor seals, and Steller sea
lions. Some of these also apply to
CIBWs; however, a more detailed
analysis for CIBWs is provided below.
• No takes by mortality or serious
injury are anticipated or authorized;
• The number of total takes (by Level
A and Level B harassment) are less than
3 percent of the best available
abundance estimates for all stocks;
• Take would not occur in places
and/or times where take would be more
likely to accrue to impacts on
reproduction or survival, such as within
ESA-designated or proposed critical
habitat, biologically important areas
(BIA), or other habitats critical to
recruitment or survival (e.g., rookery);
• Take would occur over a short
timeframe, being limited to the short
duration a marine mammal would likely
be present within a Level B harassment
zone during pile driving;
• Any impacts to marine mammal
habitat from pile driving are temporary
and minimal; and
• Take would only occur within
upper Cook Inlet—a limited, confined
area of any given stock’s home range.
For CIBWs, we further discuss our
negligible impact finding in the context
of potential impacts to this endangered
stock. As described in the Recovery Plan
for the Cook Inlet Beluga Whale (NMFS,
2016), NMFS determined the following
physical or biological features are
essential to the conservation of this
species: (1) Intertidal and subtidal
waters of Cook Inlet with depths less
than 30 feet mean lower low water (9.1
m) and within 5 mi (8 km) of high and
medium flow anadromous fish streams;
(2) Primary prey species consisting of
four species of Pacific salmon (Chinook,
sockeye, chum, and coho), Pacific
eulachon, Pacific cod, walleye pollock,
saffron cod, and yellowfin sole, (3)
Waters free of toxins or other agents of
a type and amount harmful to CI beluga
whales, (4) Unrestricted passage within
or between the critical habitat areas, and
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(5) Waters with in-water noise below
levels resulting in the abandonment of
critical habitat areas by CI beluga
whales. The PCT would not impact
essential features 1–3 listed above. All
construction would be done in a manner
implementing best management
practices to preserve water quality and
no work would occur around creek
mouths or river systems leading to prey
abundance reductions. In addition, no
physical structures would restrict
passage; however, impacts to the
acoustic habitat are of concern. Previous
marine mammal monitoring data at the
POA demonstrate beluga whales indeed
pass by the POA during pile driving. As
described above, there was no
significant difference in beluga sighting
rate with and in the absence of pile
driving (Kendell and Cornick, 2015).
However, beluga whales do swim faster
and in tighter formation in the presence
of pile driving (Kendell and Cornick,
2015).
During review of the POA’s
application, NMFS was concerned that
exposure to pile driving at the PCT
could result in beluga whales avoiding
Knik Arm and thereby not accessing the
productive foraging grounds north of
POA such as Eagle River flats based on
the proposed project and mitigation
measures—thus, impacting essential
feature number 5 above. Although the
data previously presented demonstrate
whales are not abandoning the area (i.e.,
no significant difference in sighting rate
with and without pile driving), we
considered the results of a recent expert
elicitation (EE) at a 2016 workshop,
which predicted the impacts of noise on
CIBW survival and reproduction given
lost foraging opportunities, to inform
our assessment of impacts on this stock.
The 2016 EE workshop used conceptual
models of an interim population
consequences of disturbance (PCoD) for
marine mammals (NRC 2005; New et al.
2014, Tollit et al., 2016) to help in
understanding how noise-related
stressors might affect vital rates
(survival, birth rate and growth) for
CIBW (King et al. 2015). NMFS (2015,
section IX.D—CI Beluga Hearing,
Vocalization, and Noise Supplement)
suggests that the main direct effects of
noise on CIBW are likely to be through
masking of vocalizations used for
communication and prey location, and
habitat degradation. The 2016 workshop
on beluga whales was specifically
designed to provide regulators with a
tool to help understand whether chronic
and acute anthropogenic noise from
various sources and projects are likely
to be limiting recovery of the CIBW
population. The full report can be found
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at https://www.smruconsulting.com/
publications/ and we provide a
summary of the expert elicitation
portion of the workshop here.
For each of the noise effect
mechanisms chosen for expert
elicitation, the experts to provide a set
of parameter values that determined the
forms of a relationship between the
number of days of disturbance a female
CIBW experiences in a particular period
and the effect of that disturbance on her
energy reserves. Examples included the
number of days of disturbance during
the period April, May and June that
would be predicted to reduce the energy
reserves of a pregnant CIBW to such a
level that she is certain to terminate the
pregnancy or abandon the calf soon after
birth, the number of days of disturbance
in the period April-September required
to reduce the energy reserves of a
lactating CIBW to a level where she is
certain to abandon her calf, and the
number of days of disturbance where a
female fails to gain sufficient energy by
the end of summer to maintain
themselves and their calves during the
subsequent winter. Overall, median
values ranged from 16 to 69 days of
disturbance depending on the question.
However, for this elicitation, a ‘‘day of
disturbance’’ was defined as any day on
which an animal loses the ability to
forage for at least one tidal cycle (i.e., it
forgoes 50–100% of its energy intake on
that day). Therefore, disturbance in this
context is not equivalent to Level B
harassment. The mitigation measures
NMFS has proposed for the PCT project
are designed to avoid the potential that
any animal would lose the ability to
forage for one or more tidal cycles.
While Level B harassment (behavioral
disturbance) is proposed to be
authorized, our mitigation measures
would minimize the intensity of that
harassment to behavioral changes such
as increased swim speeds, tighter group
formations, and cessation of
vocalizations, not the loss of foraging
capabilities. Regardless, this elicitation
recognized that pregnant or lactating
females and calves are inherently more
at risk than other animals, such as
males. NMFS first considered proposing
the POA shutdown based on more
vulnerable life stages (e.g., calf
presence) but ultimately determined all
beluga whales warranted pile driving
shutdown to be protective of potential
vulnerable life stages, such as
pregnancy, that could not be determined
from observations, and to avoid more
severe behavioral reaction.
Monitoring data from the POA suggest
pile driving does not discourage beluga
whales from entering Knik Arm and
travelling to critical foraging grounds
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such as those around Eagle Bay. As
previously described, sighting rates
were not different in the presence or
absence of pile driving. This is not
surprising as food is a strong motivation
for marine mammals. As described in
Forney et al. (2017), animals typically
favor particular areas because of their
importance for survival (e.g. feeding or
breeding), and leaving may have
significant costs to fitness (reduced
foraging success, increased predation
risk, increased exposure to other
anthropogenic threats). Consequently,
animals may be highly motivated to
remain in an area despite negative
impacts (e.g., Rolland et al. 2012).
Previous monitoring data indicates
beluga whales are responding to pile
driving noise but not through
abandonment of critical habitat,
including primary foraging areas north
of the port. Instead, they travel faster
past the POA, more quietly, and in
tighter groups (which may be linked to
the decreased communication patterns).
We anticipate these behaviors to
continue; however, do not believe they
had adverse effects on reproduction or
survival as the whales continue to
access critical foraging grounds north of
the POA and tight associations combat
any communication space lost within a
group. Finally, as described previously,
beluga whales likely stay in upper Knik
Arm for several days before exiting Knik
Arm. Acoustic data indicate beluga
whales move through lower Knik Arm
relatively quickly, when entering or
exiting the arm, and remain in the upper
arm for several days, or weeks, before
moving back out into Cook Inlet
(Castellote et al., in press). Satellite
telemetry data indicate such a
movement pattern may be common.
Specifically, a beluga instrumented with
a satellite link time/depth recorder
entered Knik Arm on August 18th and
remained in Eagle Bay until September
12th (Ferrero et al. 2000). This longerterm use of upper Knik Arm would
avoid repetitive exposures from pile
driving noise.
NMFS has included mitigation
measures beyond those proposed by the
POA in the IHA application,
specifically, not commencing pile
driving if beluga whales are observed
within Knik Arm or within 1 km of the
mouth of Knik Arm, shutting down pile
driving should a beluga whale approach
or enter the Level B harassment zone,
stationing PSOs at Point Woronzof, and
not vibratory pile driving 144-in piles
during August (peak beluga season).
These measures are designed to ensure
beluga whales will not abandon critical
habitat and exposure to pile driving
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noise will not result in adverse impacts
on the reproduction or survival of any
individuals. The location of PSOs at
Point Woronzof allows for detection of
beluga whales at much farther distances
than previous years and behavioral
observations prior to whales entering
Knik Arm. Although NMFS does not
anticipate beluga whales would
abandon entering Knik Arm in the
presence of pile driving with the
proposed mitigation measures, these
PSOs will be integral to identifying if
belugas are potentially altering
pathways they would otherwise take in
the absence of pile driving. Because the
POA is submitting weekly and monthly
reports, NMFS will be able to regularly
evaluate the impacts of the project on
beluga whales. Finally, take by
mortality, serious injury, or Level A
harassment of CIBWs is not anticipated
or proposed to be authorized.
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 CIBWs
through effects on annual rates of
recruitment or survival:
• No mortality or serious injury is
anticipated or authorized.
• Area of exposure would be limited
to travel corridors. Data demonstrates
Level B harassment manifests as
increased swim speeds past the POA
and tight group formations and not
through habitat abandonment.
• No critical foraging grounds (e.g.
Eagle Bay, Eagle River, Susitna Delta)
would be impacted by pile driving.
• While animals could be harassed
more than once, exposures are not likely
to exceed more than a few per year for
any given individual and are not
expected to occur on sequential days;
thereby, decreasing the likelihood of
physiological impacts caused by chronic
stress or masking.
Based on the analysis contained
herein of the likely effects of the
specified activity on marine mammals
and their habitat, and taking into
consideration the implementation of the
proposed monitoring and mitigation
measures, NMFS preliminarily finds
that the total marine mammal take from
the proposed activity will have a
negligible impact on all affected marine
mammal species or stocks.
Small Numbers
As noted above, only small numbers
of incidental take may be authorized
under Sections 101(a)(5)(A) and (D) of
the MMPA for specified activities other
than military readiness activities. The
MMPA does not define small numbers
and so, in practice, where estimated
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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.
For all stocks, the amount of taking is
small relative to the population size (0.2
to 17 percent). Further, the amount of
take proposed to be authorized likely
represents smaller numbers of
individual harbor seals and Steller sea
lions. Harbor seals tend to concentrate
near Ship Creek and have small home
ranges; therefore, the amount of take
authorized likely represents repeat
exposures to the same animals. Previous
Steller sea lion sightings identified that
if a Steller sea lion is within Knik Arm,
it is likely lingering to forage on salmon
or eulachon runs and may be present for
several days. With respect to CIBW, they
are known to enter Knik Arm and then
exit after several days of remaining
within Knik Arm. There is potential an
individual is taken on both ingress and
egress; however, due to the mitigation
measures (essentially takes are for
animals where pile driving cannot be
shut down before exposure), the
circumstances would have to be such
that pile driving is occurring while the
whale is both entering and exiting Knik
Arm and that the animal is missed or
taken due to logistical constraints of
shutting down pile driving immediately
in both cases. Therefore, the potential
for repeat takes is low and we anticipate
take predominantly represents
individual animals. Regardless, the
amount of take proposed to be
authorized for CIBW is small (17
percent or less).
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 sizes of
the affected species or stocks.
Unmitigable Adverse Impact Analysis
and Determination
There are no relevant subsistence uses
of the affected marine mammal stocks or
species implicated by this action. No
subsistence use of CIBWs occurs and
subsistence harvest of other marine
mammals is limited. The potential
impacts from harassment on stocks that
are harvested would be limited to minor
behavioral changes (e.g., increased swim
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speeds, changes in dive time, temporary
avoidance near the POA, etc.) within the
vicinity of the POA. Therefore, NMFS
has determined that the total taking of
affected species or stocks would not
have an unmitigable adverse impact on
the availability of such species or stocks
for taking for subsistence purposes.
Endangered Species Act (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 Region Protected
Resources Division Office, whenever we
propose to authorize take for
endangered or threatened species.
NMFS is proposing to authorize take
of CIBWs, humpback whales from the
Mexico DPS stock, and Steller sea lions
from the western DPS, which are listed
under the ESA. Therefore, the Permit
and Conservation Division has
requested initiation of Section 7
consultation with the Alaska Region for
the issuance of this IHA. NMFS will
conclude the ESA consultation prior to
reaching a determination regarding the
proposed issuance of the authorization.
Proposed Authorization
As a result of these preliminary
determinations, NMFS proposes to issue
an IHA to the POA for the PCT Project,
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-undermarine-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 POA’s PCT Project. 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
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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:
• A request for renewal is received no
later than 60 days prior to expiration of
the current IHA.
• The request for renewal must
include the following:
(1) An explanation that the activities
to be conducted beyond the initial dates
either are identical to the previously
VerDate Sep<11>2014
20:13 Dec 27, 2019
Jkt 250001
analyzed activities or include changes
so minor (e.g., reduction in pile size)
that the changes do not affect the
previous analyses, take estimates, or
mitigation and monitoring
requirements.
(2) A preliminary monitoring report
showing the results of the required
monitoring to date and an explanation
showing that the monitoring results do
not indicate impacts of a scale or nature
not previously analyzed or authorized.
• Upon review of the request for
renewal, the status of the affected
PO 00000
Frm 00032
Fmt 4701
Sfmt 9990
species or stocks, and any other
pertinent information, NMFS
determines that there are no more than
minor changes in the activities, the
mitigation and monitoring measures
remain the same and appropriate, and
the original findings remain valid.
Dated: December 20, 2019.
Donna S. Wieting,
Director, Office of Protected Resources,
National Marine Fisheries Service.
[FR Doc. 2019–28102 Filed 12–27–19; 8:45 am]
BILLING CODE 3510–22–P
E:\FR\FM\30DEN2.SGM
30DEN2
Agencies
[Federal Register Volume 84, Number 249 (Monday, December 30, 2019)]
[Notices]
[Pages 72154-72184]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-28102]
[[Page 72153]]
Vol. 84
Monday,
No. 249
December 30, 2019
Part II
Department of Commerce
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National Oceanic and Atmospheric Administration
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Takes of Marine Mammals Incidental to Specified Activities; Taking
Marine Mammals Incidental to Construction of the Port of Alaska's
Petroleum and Cement Terminal, Anchorage, Alaska; Notice
Federal Register / Vol. 84 , No. 249 / Monday, December 30, 2019 /
Notices
[[Page 72154]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XR027]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Construction of the Port of
Alaska's Petroleum and Cement Terminal, Anchorage, Alaska
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization; request
for comments on proposed authorization and possible renewal.
-----------------------------------------------------------------------
SUMMARY: NMFS has received a request from the Port of Alaska (POA) for
authorization to take marine mammals incidental to pile driving
associated with the construction of a new Petroleum and Cement Terminal
(PCT) in Knik Arm, Alaska. Pursuant to the Marine Mammal Protection Act
(MMPA), NMFS is requesting comments on its proposal to issue two
successive incidental harassment authorizations (IHAs) to incidentally
take marine mammals during the specified activities. NMFS is also
requesting comments on possible one-year renewals 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 January
29, 2020.
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: Jaclyn Daly, 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. Under the MMPA, ``take'' is defined as meaning to harass,
hunt, capture, or kill, or attempt to harass, hunt, capture, or kill
any marine mammal.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of such species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of such takings are set forth. The definitions
of all applicable MMPA statutory terms cited above are included in the
relevant sections below.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an
incidental harassment authorization) with respect to potential impacts
on the human environment.
Accordingly, NMFS is preparing an Environmental Assessment (EA) to
consider the environmental impacts associated with the issuance of the
proposed IHA. NMFS' EA will be made available at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. We will review all comments submitted in
response to this notice prior to concluding our NEPA process or making
a final decision on the IHA request.
Summary of Request
On November 28, 2018, NMFS received a request from the POA for an
IHA to take marine mammals incidental to pile driving associated with
the construction of the PCT. On June 19, 2019, the POA submitted a
subsequent, after request realizing the project would take two
construction seasons (April-November) to complete. Because of this
modified construction schedule, the POA submitted a new application on
July 19, 2019 and a revised application on August 9, 2019. Although
NMFS disagreed with some of the analysis in the application (as
described later in this document), we deemed it adequate and complete
on August 28, 2019, because it contained all the information necessary
for us to conduct our MMPA analysis. The POA submitted a subsequent
revised application on October 15, 2019, which is available at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. The POA's request is for take of small
numbers of six species of marine mammals, by Level B harassment. Four
of the species could also be taken by Level A harassment. Neither the
POA nor NMFS expects serious injury or mortality to result from this
activity; therefore, an IHA is appropriate.
NMFS previously issued IHAs and Letters of Authorization (LOAs) to
the POA for pile driving (73 FR 41318, July 18, 2008; 74 FR 35136, July
20, 2009; and 81 FR 15048; March 21, 2016). The POA complied with all
the requirements
[[Page 72155]]
(e.g., mitigation, monitoring, and reporting) of all previous
incidental take authorizations and did not exceed authorized take.
Information regarding their monitoring results may be found in the
Effects of the Specified Activity on Marine Mammals and their Habitat
and Estimated Take sections.
Description of Proposed Activity
Overview
The POA proposes to construct a new PCT comprised of a pile-
supported structure located along the southernmost shoreline of the POA
(see Figure 1-1 and Figure 1-2 in the POA's IHA application), as part
of its Port of Alaska Modernization Project (PAMP). In general, the
PAMP will include construction of new pile-supported wharves and
trestles south and west of the existing terminals, with a planned
design life of 75 years. The proposed project, the PCT project, is one
component of the PAMP.
The PCT project will replace the existing Petroleum Oil Lubricants
Terminal which is currently the only bulk cement-handling facility in
Alaska and is the primary terminal for receipt of refined petroleum
products. The PCT Project will involve new construction of a loading
platform, access trestle, and dolphins; and installation of utilities
(electricity, water, and communication), petroleum, and cement lines
linking the terminal and shore. Ships mooring to the PCT will utilize
both breasting dolphins and mooring dolphins. The PCT will be designed
to satisfy project-specific seismic performance criteria, allowing the
terminal to be quickly restored to service following a major seismic
event such as the magnitude 7.0 earthquake that struck Anchorage on
November 30, 2018.
The POA will install three breasting dolphins and six mooring
dolphins as well as a new loading platform and catwalks. In addition to
these permanent structures, temporary access trestles will be installed
and subsequently removed. Pile installation will occur in water depths
that range from a few feet or dry conditions nearest the shore to
approximately 80 feet at the outer face of the loading platform,
depending on tidal stage. Various work boats and barges will be
utilized to support construction. Work will be completed over two
construction seasons (April through November): Phase 1 will occur in
2020 and Phase 2 will occur in 2021.
Dates and Duration
POA anticipates two construction seasons (April-November) will be
required to complete the PCT terminal. The POA has requested two IHAs
to cover this work. These IHAs correspond with Phase 1 and Phase 2. The
POA anticipates 359 hours of pile driving and removal over 127 days in
Phase 1 and 229 hours of pile driving and removal over 75 days in Phase
2. For each phase, construction mobilization is planned to commence the
first week of April, with the potential to initiate pile installation
activities by mid-April. Construction demobilization is planned to
occur in November, with the expectation to remove the final temporary
piles by the first week of November. Between April and November, piles
will be installed and removed during daylight hours only.
Specific Geographic Region
Cook Inlet is a large tidal estuary that exchanges waters at its
mouth with the Gulf of Alaska. The inlet is roughly 20,000 square
kilometers (km\2\; 7,700 square miles [mi\2\]) in area, with
approximately 1,350 linear kilometers (840 miles) of coastline (Rugh et
al. 2000) and an average depth of approximately 100 meters (330 feet).
Cook Inlet is generally divided into upper and lower regions by the
East and West Forelands. Northern Cook Inlet bifurcates into Knik Arm
to the north and Turnagain Arm to the east. The POA is located in the
southeastern shoreline of Knik Arm (Figure 1).
Knik Arm is generally considered to begin at Point Woronzof, 7.4
kilometers (4.6 miles) southwest of the POA. From Point Woronzof, Knik
Arm extends about 48 kilometers (30 miles) in a north-northeasterly
direction to the mouths of the Matanuska and Knik rivers. At Cairn
Point, just northeast of the POA, Knik Arm narrows to about 2.4
kilometers (1.5 miles) before widening to as much as 8 kilometers (5
miles) at the tidal flats northwest of Eagle Bay at the mouth of Eagle
River, which are heavily utilized by Cook Inlet beluga whales (CIBWs).
Approximately 60 percent of Knik Arm is exposed at mean lower low water
(MLLW). The intertidal (tidally influenced) areas of Knik Arm,
including those at the POA, are mudflats, both vegetated and
unvegetated, which consist primarily of fine, silt-sized glacial flour.
The POA's boundaries currently occupy an area of approximately 129
acres. Other commercial and industrial activities related to secure
maritime operations are located near the POA on Alaska Railroad
Corporation (ARRC) property immediately south of the POA, on
approximately 111 acres.
BILLING CODE 3510-22-C
[[Page 72156]]
[GRAPHIC] [TIFF OMITTED] TN30DE19.010
BILLING CODE 3510-22-P
Detailed Description of Specific Activity
Located within the Municipality of Anchorage on Knik Arm in upper
Cook Inlet (see Figure 1-1 in the POA's IHA application), the POA's
existing infrastructure and support facilities were constructed largely
in the 1960s. Port facilities are substantially past their design life,
have degraded to levels of marginal safety, and are in many cases
functionally obsolete, especially in
[[Page 72157]]
regard to seismic design criteria and condition.
The purpose for the PCT Project is to replace the existing
Petroleum Oil Lubricants Terminal (POL 1), the only bulk cement-
handling facility in Alaska and the primary terminal for receipt of
refined petroleum products. POL 1, built in 1965, is more than 50 years
old and consists of 160 wharf pilings that are uncoated, hollow-steel
pile. The need for the PCT is based on the heavily deteriorated
physical condition of POL 1. It suffers from severe corrosion of its
foundation pilings to levels of marginal safety, as evidenced by
currently imposed load restrictions. A 2014 pile condition assessment
found severe corrosion throughout the facility, with pile wall losses
exceeding 67 percent of their original thickness. It also sustained
structural damage from a magnitude 7.1 earthquake that struck the area
on November 30, 2018. Recent inspections in 2019 have led engineers to
confirm that the stress imposed on the already-weakened structure by
the November 30 quake caused some piling failure and predisposes the
docks to additional failure during future earthquakes. The PCT has been
designed to satisfy project-specific seismic performance criteria,
allowing the terminal to be quickly restored to service following a
major seismic event. POL 1 is functionally obsolete, has exceeded its
useful life, and is unlikely to withstand another such earthquake.
The PCT Project includes three major components: (1) A loading
platform in Phase 1, (2) an access trestle (bridge-like structure
allowing access to the loading platform) in Phase 1, and (3) breasting
and mooring dolphins in Phase 2 (see Table 1-1). A temporary work
trestle and temporary templates are required for constructing the
permanent access trestle in Phase 1, and temporary templates are
required for constructing the dolphins in Phase 2. During both Phase 1
and Phase 2, temporary mooring dolphins will be required to accommodate
construction barges and to moor construction vessels. Piles will be
installed primarily with an impact hammer; however, some vibratory pile
driving is also required. A bubble curtain will be deployed to reduce
in-water sound levels during PCT construction for impact and vibratory
hammer pile installation of 144-, 48-, 36-, and 24-inch plumb
(vertical) piles and vibratory hammer removal of 36- and 24-inch plumb
piles (all temporary and permanent piles). A bubble curtain will not be
deployed during installation and removal of 24-inch battered (installed
at an angle, not vertical) piles for the temporary construction work
trestle and temporary dolphins due to the difficult geometric
application.
All Phase 1 work will occur under the first IHA, while Phase 2 work
will occur under the second IHA. Pile sizes and quantities for
permanent and temporary components for each phase are shown in Table 1-
1; estimates of the time required to install or remove piles for each
phase are shown in Table 1-2.
Table 1-1--Summary of PCT Project Components and Activities
----------------------------------------------------------------------------------------------------------------
Total amount or
Type of activity Location Phase Size and type number
----------------------------------------------------------------------------------------------------------------
Permanent Components
----------------------------------------------------------------------------------------------------------------
Permanent pile installation In water............. 1 48-inch steel pipe 45 piles.
(loading platform). (plumb).
Permanent pile installation In water............. 1 48-inch steel pipe 26 piles.
(access trestle). (plumb).
Permanent pile installation In water............. 2 144-inch steel pipe 9 piles.
(breasting and mooring dolphins). (plumb).
Installation of concrete decking Above water.......... 1 Pre-cast panels..... About 120 panels.
on loading platform and main
trestle.
Catwalks.......................... Above water.......... 2 Prefabricated steel 9 units, totaling
or aluminum trusses 990 feet.
with open steel
grating.
----------------------------------------------------------------------------------------------------------------
Construction Support and Temporary Components
----------------------------------------------------------------------------------------------------------------
Vessel support.................... In water............. 1 & 2 Barges and tugs..... 16 flat deck barges,
2 derrick barges,
and 3-4 tugs.
Temporary pile installation In-water............. 1 24-inch steel pipe 26 piles
(construction work trestle). 1 (plumb). 10 piles.
24-inch steel pipe
(battered).
Temporary pile installation In-water............. 2 36-inch steel pipe 72 piles.
(dolphin templates). (plumb).
Temporary pile installation In-water............. 1 36-inch steel pipe 26 piles.
(construction work trestle). (plumb).
Temporary pile installation In-water............. 1 24-inch steel pipe 36 piles.
(access trestle templates). (plumb).
Temporary mooring anchor systems.. In-water............. 1 & 2 20,000 pound 2 mooring systems.
Danforth anchors.
Temporary derrick barge........... In-water............. 1 & 2 36-inch steel pipe 4 piles.
(plumb).
Temporary dolphins for mooring In-water............. 1 & 2 24-inch steel pipe 3 dolphins, each
construction vessels. (plumb). with 1 plumb and 2
4-inch steel pipe battered piles (9
(battered). piles total).
----------------------------------------------------------------------------------------------------------------
Installation of Utility, Petroleum, and Cement Lines
----------------------------------------------------------------------------------------------------------------
Installation on access trestle and Above water, on-dock. 1 Pipelines, various 300-600 linear feet
loading platform. sizes and types. each.
----------------------------------------------------------------------------------------------------------------
[[Page 72158]]
Table 1-2--PCT Construction Pile Details and Estimated Effort Required for Pile Installation and Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Average Vibratory Estimated Production
Number of Total embedded duration Impact strikes per total rate piles Days of
Pipe pile diameter Feature \a\ piles number of depth per pile pile number of per day installation and
piles (feet) (minutes) hours (range) removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Phase 1
--------------------------------------------------------------------------------------------------------------------------------------------------------
48-inch........... Loading Platform.... 45 71 100 30 2,300 (50 restrikes 73 1.5 30.
each for 4 piles).
Access Trestle...... 26 130 3,000 (50 restrikes 56 (1-3) 17.
each for 3 piles).
36-inch........... Temporary 26 30 115 75 50 restrikes for 10 33 3 9 installation.
Construction Work piles. (2-4) 9 removal.
Trestle.
Temporary Derrick 4 40 75 NA................. 5 4 1 installation.
Barge. 1 removal.
24-inch........... Temporary 26 81 140 75 50 restrikes of 10 65 3 9 installation
Construction Work piles. (2-4) 9 removal.
Trestle.
Temporary 10 105 75 NA................. 25 1.6 6 installation.
Construction Work (1-2) 6 removal.
Trestle, Battered.
Temporary 36 105 75 NA................. 90 3 12 installation.
Construction Access (2-4) 12 removal.
Trestle Template.
Temporary Dolphins 3 50 30 NA................. 3 3 1 installation.
for mooring 1 removal.
construction
vessels.
Temporary Dolphins 6 50 30 NA................. 9 3 2 installation.
for mooring 2 removal.
construction
vessels, Battered.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Phase 1 Construction Totals........................ 182 piles .......... ........... ................... 359 .......... 127.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Phase 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-inch........... Temporary Dolphins 3 9 50 30 NA................. 3 3 1 installation.
for mooring 1 removal.
construction
vessels.
Temporary Dolphins 6 50 30 NA................. 9 3 2 installation.
for mooring 2 removal.
construction
vessels, Battered.
36-inch........... Temporary 72 76 115 75 NA................. 180 3 (2-4) 24 installation.
Construction 24 removal.
Dolphin Template.
Temporary derrick 4 40 75 NA................. 5 4 1 installation.
barge. 1 removal.
144-inch.......... Mooring Dolphin..... 6 9 140 45 ( 1 5,000 (1,500 first 21 0.5 13.
pile) day, 3,500 second
day).
Breasting Dolphin... 3 135 11 (0.3 or 6.
0.7)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Phase 2 Construction Totals........................ 94 piles .......... ........... ................... 229 .......... 75.
--------------------------------------------------------------------------------------------------------------------------------------------------------
The estimated source levels for each pile type and installation
method are provided in Table 2. These source levels are from the
acoustic monitoring during the POA's 2016 Test Pile Program (TPP) (for
48-in piles) and investigation of existing literature at other
locations for non-48-in piles.
Table 2--Estimated Pile Source Levels With and Without Bubble Curtains
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Method and pile size Sound level at 10 m Data source
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unattenuated
Bubble curtain ..............
Vibratory db rms
7 dB reduction, dB rms ..............
--------------------------------------------------------------------------------------------------------------------------------------------------------
144-in............................ 178
171 Caltrans 2015.
48-in............................. 168
161 Austin et al
2016.
36-in............................. 166
159 Navy 2015.
24-in............................. 161
154 Navy 2015.
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unattenuated Bubble curtain
Impact ------------------------------------------------------------------------------------------------
dB rms dB SEL dB peak dB rms dB SEL dB peak
--------------------------------------------------------------------------------------------------------------------------------------------------------
144-in............................ 209 198 220 202 191 213 Caltrans 2015.
48-in............................. 200 187 215 193 180 208 Austin et al. 2016.
[[Page 72159]]
36-in............................. 194 184 211 187 177 204 Navy 2015.
24-in............................. 193 181 210 186 174 203 Navy 2015.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Phase 1--Loading Platform and Access Trestle Construction Description
Phase 1 will take place during 2020 and will include construction
of the loading platform and access trestle. Construction will be
accomplished from two concurrent headings or directions; one marine-
side derrick barge with a crane/hammer will be used to construct the
loading platform, and a land-side crawler crane/hammer will be used to
construct the temporary and permanent access trestle from the shoreline
out. The crawler crane will initially advance the temporary work
trestle out from the shoreline with a top-down or leap-frog type
construction method, and then the crawler crane will work off of the
temporary work trestle to construct the permanent trestle all the way
out to the loading platform.
For the loading platform, which is supported with 48-inch piles,
the contractor will first mobilize the marine-based derrick barge on
the seaward side of the platform location and install four temporary
mooring piles to stabilize the derrick barge during the construction
season. Also, three temporary mooring dolphins will be constructed in
the vicinity of the PCT to serve as mooring for construction vessels
and barges containing construction materials, and will be removed at
the end of the construction season. The derrick barge will host the
crane and hammer used to install the permanent loading platform piles
and decking. Each of the platform piles will be installed using an
impact hammer with a bubble curtain applied. A vibratory hammer would
only be used in the infrequent event that an obstruction were
encountered while driving the pile that requires removal or
repositioning of the pile with a vibratory hammer.
Four of the permanent platform piles will be ``proofed'' to confirm
their ability to withstand design loads. Proofing involves
approximately 50 impact hammer restrikes over an approximate 10-minute
period while instrumentation is attached to the pile during restrike to
confirm design conformance. Pile cleanout activities, to prepare the
interior of the hollow pile for partial concrete filling, will occur
only in the top portion of the pile, but not below mudline. Any
material adhered to the top inside of the pile will be removed to
prepare for concrete installation, and a soffit form will be inserted
into the hollow pile to prevent the closure pour concrete from reaching
mudline. Formwork will be constructed around the top of the pile, out
of the water, to support placement of a precast concrete cap on top of
each pile. The closure pour, where concrete is poured into the pile
above the soffit form, connects the pile to the precast pile caps,
bonding the pile to the cap. Precast platform panels are then placed on
the deck, and additional concrete will be poured on top of the panels
to create the platform decking.
For the access trestle, the permanent access trestle construction
requires construction of a parallel temporary trestle, installed
adjacent to the permanent trestle, from which to advance the temporary
piles used for templates and installation of the permanent access
trestle piles. While the permanent trestle requires 48-inch piles, the
temporary trestle will be constructed using 24- and 36-inch piles.
Initial construction of the temporary work trestle will be advanced
first; then, as the work trestle advances water-ward and room is made
available to accommodate construction equipment, work will commence on
construction of the permanent access trestle coincidentally as the
temporary work trestle is advanced water-ward toward the loading
platform.
Construction of the trestles will occur concurrently with
construction of the loading platform. A crawler crane will be used to
install piles for the temporary trestle, building seaward from the
shore using a top-down or leap-frog construction method. The crawler
crane will advance onto the temporary trestle to complete pile
installation and decking for the temporary trestle. Once the first
section of temporary trestle is constructed and the crawler crane is
advanced, a second crawler crane will advance onto the deck of the
temporary trestle and be used to install the first section of template
and permanent piles for the permanent access trestle (see Pile Driving
Scenarios, below).
Three of the permanent trestle piles will be ``proofed'' to confirm
their ability to withstand design loads. In addition, it is estimated
that 10 each of the 24- and 36-inch temporary work trestle piles may
need to be proofed to confirm load capacities for construction
equipment. Template piles will stay in place until precast pile caps
are placed on the permanent trestle piles following installation. The
temporary trestle will stay in place for the entire construction
season, and will be used as a work platform for decking installation on
the permanent trestle. The temporary trestle decking and piles will be
removed at the end of construction activities for Phase 1. Removal is
expected to require the same amount of time as installation due to the
strong pile setup and resistance conditions related to Knik Arm
sediments.
The permanent access trestle is comprised of eight bents (clusters)
of three piles each and one bent of two piles at the abutment. The
abutment bent (two piles) is located above mean high water on shore and
will be installed in the dry. The next three bents are located in the
intertidal zone and therefore may or may not be installed in water
depending upon the tidal stage (i.e., if the tide is high, they may be
in water, but if the tide is low, they will not be in water). The
parallel temporary construction trestle will follow the same pattern.
For purposes of this analysis, it is assumed that all piles will be
driven in water; however, if piles are driven in the dry during actual
construction, takes of marine mammals will be assumed not to occur.
Also, some of the permanent trestle piles may be started/partially
driven with a vibratory hammer when in the dry at the abutment (two
piles) and the first three bents (three piles each) in order to set the
pile up for impact hammer installation; this condition also is not
expected to generate takes. This is a unique situation at this location
due to the highly variable tidal conditions and the need to provide
initial pile support for impact hammer installation.
To construct the loading platform and permanent access trestle,
piles will be installed using an impact hammer to drive through the
overburden sediment layer and into the bearing layer, to an average
embedded depth of about 100 feet (loading platform piles) and 130 feet
(access trestle piles) below the substrate. Installation and removal of
all temporary piles, including derrick barge mooring piles, mooring
dolphin piles for mooring construction vessels,
[[Page 72160]]
temporary access trestle piles, and templates for installation of the
permanent access trestle piles, will use vibratory hammer methods.
Limited vibratory hammer application may be required for loading
platform and permanent trestle piles due to safety reasons,
constructability, or if a pile encounters an obstruction.
Phase 2--Mooring and Breasting Dolphins Construction Description
Phase 2 will occur in 2021 and will include construction of the
mooring and breasting dolphins. Construction will be accomplished from
one marine-based derrick barge with a crane/hammer work station.
Similar to Phase 1, the contractor will initially install four
temporary mooring piles to stabilize the derrick barge during the
construction season. Also, three temporary mooring dolphins will be
constructed in the vicinity of the PCT to serve as mooring for
construction vessels and barges containing construction materials, and
will be removed at the end of the construction season. The derrick
barge will host the crane and hammer used to install the mooring and
breasting dolphins. Temporary template piles will then be installed to
anchor the template that will guide the installation of the permanent
dolphin piles at each of the dolphin locations. Template piles will be
installed approximately 115 feet into the substrate. Temporary template
piles will be driven in a grid formation surrounding the location of
each dolphin pile, with a steel framework bolted to the temporary piles
to guide dolphin pile installation. The framework includes adjustable
components and hydraulic guides that can be adjusted to maintain
correct positioning of the dolphins once they are in place. All
template piles will be aligned plumb (vertically) and installed and
removed using a vibratory hammer due to accuracy requirements for
setting the template. All plumb piles will employ a bubble curtain
during all pile-driving activity.
Ships mooring to the PCT will utilize both breasting dolphins and
mooring dolphins. To meet required structural demands, monopile
dolphins are planned for both the breasting and mooring dolphins.
Breasting dolphins are designed to assist in the berthing of vessels by
absorbing some of the lateral load during vessel impact. Breasting
dolphins also protect the loading platform from impacts by vessels.
Mooring dolphins, as their name implies, are used for mooring only and
provide a place for a vessel to be secured by lines (ropes). Use of
mooring dolphins helps control transverse and longitudinal movements of
berthed vessels.
In total, nine 144-in mooring and breasting dolphins will be
installed at the PCT. Six mooring dolphins will be constructed parallel
to and landward of the loading platform face and three breasting
dolphins will be installed in alignment with the loading platform
(Figure 1-2 in the POA's IHA application). These dolphins will provide
for secure ship docking at the terminal. Each mooring and breasting
dolphin will be comprised of a single round 144-inch steel pipe pile or
monopile, driven to an average embedded depth of about 140 feet below
the substrate.
Following temporary pile installation with a vibratory hammer of
the dolphin template, held in place with 36-inch piles, the crane will
loft the first permanent pile length (approximately 100 feet) and ready
it for lowering through the template framework. The crane will have a
boom holding the top of the pile as well as a spotter arm lower on the
pile to steady the pile for positioning. The pile will then be lowered
through the template and readied for pile driving. Impact pile driving
will be used to advance the pile to a prescribed depth, at which point
pile-driving activity will stop to allow field splicing of the second
pile length. Decking will be added to the temporary pile template
framework to accommodate welders; no pile driving will be conducted
during the welding and testing of the two lengths of pile, as the crane
will be holding the second pile length in place. Once the first and
second lengths of pile are spliced, pile driving will be reinitiated
until the tip is at the prescribed depth. Limited vibratory hammer
application may be required on the mooring or breasting dolphin piles
for safety reasons or if a pile encounters an obstruction.
Following monopile installation, the superstructure will be
installed atop the monopile. A precast concrete mooring cap will be
added to the monopile. The caps will be welded to the piles by an
embedded steel ring in the precast cap. This activity will not require
in-water work or hammer activity. The three breasting dolphins will
have fenders installed, which will be attached to the mooring cap and
will not require in-water or hammer work.
Once the first and second lengths of pile, ring and mooring cap,
and fender, if applicable, are assembled at the first location, the
temporary pile template will be removed using a vibratory hammer. The
barge will be repositioned to the next location, and the work activity
will commence as described above.
One crane will be used for installation of dolphin piles and
associated temporary template piles; multiple hammers will not be
employed simultaneously. Templates will be re-used at each dolphin
location. The crane will alternate between installing template piles,
driving dolphin piles, removing template piles, and out-of-water work
such as placement of decking, catwalks, and utility racks along the
platform and trestle. All terminal utility work is out of the water,
and includes installation of pipe racks and utilities along the
platform and trestle.
Phases 1 and 2--Temporary Mooring Dolphins
Three temporary mooring dolphins will be installed near the PCT
during Phases 1 and 2. Working barges and construction vessels
associated with the PCT Project will use the temporary mooring dolphins
during PCT construction. Each temporary mooring dolphin will consist of
one 24[hyphen]inch plumb pile and two 24[hyphen]inch battered piles
installed with a vibratory hammer (nine piles total).
Pile-Driving Summary--Phases 1 and 2
Pile installation will occur in water depths that range from a few
feet or dry conditions (at low tide) nearest the shore to approximately
24 meters (80 feet) at the outer face of the loading platform at high
tide, depending on tidal stage (see Figure 1-3 and Figure 1-4 in the
POA's IHA application). Figure 1-3 in the POA's IHA application shows
three test piles that were installed in 2016 and are located just
water-ward of the face of the PCT loading platform (test piles were
removed in 2019). The PCT will be constructed between these three test
piles and the shore; for illustrative purposes, the distance from the
water-ward edge of the PCT loading platform (general location of test
piles) is approximately 30 meters from mean lower low water and 115
meters from mean higher high water.
The pile-driving construction season for Phase 1 is scheduled to
commence April 15, 2020, and end the first week of November 2020
(November 7 for purposes of this analysis), with decommissioning
occurring during the remainder of November. Decommissioning will not
require in-water pile driving. Construction days when piles are not
being installed or removed will be devoted to other work such as
welding or deck work. The POA is working with their contractor to
schedule deck work and other non-pile-
[[Page 72161]]
driving work to the maximum extent practicable during the August/
September timeframe when beluga whale abundance is higher in Knik Arm.
Similarly, the pile driving construction season for Phase 2 is planned
to commence in May 2021 and end in early November 2021. The estimated
duration for installation and removal of PCT permanent and temporary
piles is shown in Table 1-2.
Pile-Driving Scenarios
During Phase 1, the POA expects to utilize three hammers on the job
site to expedite construction, including an impact hammer for loading
platform construction and an impact hammer and a vibratory hammer for
permanent and temporary work trestle construction. In order to mitigate
potential impacts to beluga whales and attempt to maximize pile
installation activities during the lower density months of occurrence
(May-July), the contractor plans to add the third crane with a
vibratory hammer to the equipment work mix in order to accelerate
construction of the temporary and permanent trestles. This could mean
that one vibratory and two impact hammers may be operating at the same
time along the trestles for brief periods of time. Use of these hammers
could also be coincidental with use of the impact hammer for
installation of the platform piles. It is not anticipated that two
vibratory hammers will be operating at the same time. Section 6.3.2.3
of the IHA application further details these conditions.
Given the proximity of the platform and trestle, hammers could work
very close to each other or as far as 100 meters away from each other.
The most likely combinations of piles that could be installed within a
day include (1) vibratory hammer installation of 24-inch temporary
piles and impact hammer installation of 48-inch permanent trestle or
loading platform piles, and (2) vibratory hammer installation of 36-
inch temporary piles and impact hammer installation of 48-inch
permanent trestle or loading platform piles.
Since only one crane will be operational during Phase 2, there will
be no additional pile-driving activity during the impact installation
of either the 36-inch temporary template piles or 144-inch monopiles.
When using two hammers, one must consider the accumulated energy, and
there are fundamental approaches for adjusting source levels to account
for the aforementioned scenarios. While two impact hammers could work
at the same time, it is unlikely that the hammers would be dropping at
the exact same time; therefore, two impact hammers would not
necessitate additional acoustic analysis.
Auxiliary Non-Pile-Driving Activities
Other activities necessary to construct the PCT involve the
installation of temporary mooring anchor systems, installation of
utility lines and pipelines, and use of cranes, tugs, and floating
barges. These activities are described in detail in the POA's IHA
application. The National Marine Fisheries Service has evaluated these
activities for the potential to harass marine mammals. Installation of
the mooring anchor systems would not elevate noise levels in Knik Arm;
therefore, marine mammal harassment is not a likely outcome. Utility,
petroleum, and cement lines will extend between the PCT loading
platform and the shore, and will connect with existing onshore
infrastructure. The installed utility lines and pipelines will be
supported by the access trestle and loading platform above marine
waters. No pile installation or removal is associated with these
auxiliary activities; therefore, no impacts on the aquatic environment,
including elevated in-water noise, are anticipated from the
installation of utility lines and pipelines.
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
There are six species of marine mammals that may be found in upper
Cook Inlet during the proposed pile driving activities. Sections 3 and
4 of the POA's 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). Additional information on beluga
whales may be found in NMFS' 2016 Recovery Plan for the Cook Inlet
Beluga Whale (Delphinapterus leucas), available online at https://www.fisheries.noaa.gov/resource/document/recovery-plan-cook-inlet-beluga-whale-delphinapterus-leucas.
Table 3 lists all species with expected potential for occurrence in
upper Cook Inlet 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 and all values presented in
Table 3 are the most recent available at the time of publication and
are available in the 2019 draft SARs (Muto et al., 2019).
[[Page 72162]]
Table 3--Marine Mammal Species Potentially Occurring in Upper Cook Inlet, Alaska
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (rorquals):
Humpback whale.................. Megaptera novaeangliae. Western North Pacific.. E/D; Y 1,107 (0.3, 865, 2006) 3 2.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
Beluga whale.................... Delphinapterus leucas.. Cook Inlet............. E/D; Y 327 (0.06, 311, 2016). 0.54 0
Killer whale.................... Orcinus orca........... Alaska Resident........ -/-; N 2,347 (N/A, 2,347, 24 1
Alaska Transient....... -/-; N 2012). 5.9 1
587 (N/A, 587, 2012)..
Family Phocoenidae (porpoises):
Harbor porpoise................. Phocoena............... Gulf of Alaska......... -/-; Y 31,046 (0.214, N/A, Undet 72
1998).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
sea lions):
Steller sea lion................ Eumetopias jubatus..... Western................ E/D; Y 54,267 (N/A, 54,267, 326 247
2017).
Family Phocidae (earless seals):
Harbor seal..................... Phoca vitulina......... Cook Inlet/Shelikof.... -/-; N 28,411 (26,907, N/A, 807 807
2018).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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 because it has not been calculated.
\3\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated
with estimated mortality due to commercial fisheries is presented in some cases.
As described below, all six species (comprising six managed MMPA
stocks) temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur, and we have proposed
authorizing it.
Humpback Whale
Currently, three populations of humpback whales are recognized in
the North Pacific, migrating between their respective summer/fall
feeding areas and winter/spring calving and mating areas (Baker et al.
1998; Calambokidis et al. 1997). Although there is considerable
distributional overlap in the humpback whale stocks that use Alaska,
the whales seasonally found in Cook Inlet are probably of the Central
North Pacific stock (Muto et al. 2017). The Central North Pacific stock
winters in Hawaii and summers from British Columbia to the Aleutian
Islands (Calambokidis et al. 1997), including Cook Inlet. The humpback
whale ESA listing final rule (81 FR 62259, September 8, 2016)
established 14 Distinct Population Segments (DPSs) with different
listing statuses. The Hawaii DPS is not listed as threatened or
endangered under the ESA. NMFS is in the process of reviewing humpback
whale stock structure under the MMPA in light of the 14 DPSs
established under the ESA.
Humpback whales are encountered regularly in lower Cook Inlet and
occasionally in mid-Cook Inlet; however, sightings are rare in upper
Cook Inlet. There have been few sightings of humpback whales near the
project area. Humpback whales were not documented during POA
construction or scientific monitoring from 2005 to 2011 or during 2016
(Cornick and Pinney 2011; Cornick and Saxon-Kendall 2008, 2009; Cornick
and Seagars 2016; Cornick et al. 2010, 2011; ICRC 2009a, 2010a, 2011a,
2012; Markowitz and McGuire 2007; Prevel-Ramos et al. 2006). Observers
monitoring the Ship Creek Small Boat Launch from August 23 to September
11, 2017 recorded two sightings, each of a single humpback whale, which
was presumed to be the same individual. One other humpback whale
sighting has been recorded for the immediate vicinity of the project
area. This event involved a stranded whale that was sighted near a
number of locations in upper Cook Inlet before washing ashore at
Kincaid Park in 2017; it is unclear as to whether the humpback whale
was alive or deceased upon entering Cook Inlet waters.
Potential concerns include elevated levels of sound from
anthropogenic sources (e.g., shipping, military sonars) but no specific
habitat concerns have been identified for this stock. Other potential
impacts include harmful algal blooms (Geraci et al. 1989), possible
changes in prey distribution with climate change, entanglement in
fishing gear, ship strikes due to increased vessel traffic (e.g., from
increased shipping in higher latitudes and through the Bering Sea with
changes in sea-ice coverage), and oil and gas activities. An
intentional unauthorized take of a humpback whale by Alaska Natives in
Toksook Bay was documented in 2016 (Muto et al., 2019); however, no
subsistence use of humpback whales occurs in Cook Inlet.
The overall trend for most humpback whale populations found in U.S.
waters is positive and points toward recovery (81 FR 62259; September
8, 2016), indicating that prey availability is not a major problem.
However, a sharp decline in observed reproduction and encounter rates
of humpback whales from the Central North Pacific stock between 2013
and 2018 has been related to oceanographic anomalies and consequent
impacts on prey resources (Cartwright et al. 2019), suggesting that
humpback whales are vulnerable to major environmental changes.
Beluga Whale
The CIBW stock is a small, geographically isolated population
separated from other beluga populations
[[Page 72163]]
by the Alaska Peninsula. The population is genetically distinct from
other Alaska populations, suggesting the peninsula is an effective
barrier to genetic exchange (O'Corry-Crowe et al. 1997). The CIBW
population is estimated to have declined from 1,300 animals in the
1970s (Calkins 1989) to about 340 animals in 2014 (Shelden et al.
2015). The precipitous decline documented in the mid-1990s was
attributed to unsustainable subsistence practices by Alaska Native
hunters (harvest of >50 whales per year) (Mahoney and Shelden 2000). In
2006, a moratorium to cease hunting was agreed upon to protect the
species.
The Cook Inlet beluga stock remains within Cook Inlet throughout
the year (Goetz et al. 2012a). NMFS designated two areas, consisting of
7,809 km2 (3,016 mi2) of marine and estuarine environments considered
essential for the species' survival and recovery as critical habitat.
However, in recent years the range of the beluga whale has contracted
to the upper reaches of Cook Inlet because of the decline in the
population (Rugh et al. 2010). Area 1 of the CIBW critical habitat
encompasses all marine waters of Cook Inlet north of a line connecting
Point Possession (61.04[deg] N, 150.37[deg] W) and the mouth of Three
Mile Creek (61.08.55[deg] N, 151.04.40[deg] W), including waters of the
Susitna, Little Susitna, and Chickaloon Rivers below mean higher high
water (MHHW). This area provides important habitat during ice-free
months and is used intensively by Cook Inlet beluga between April and
November (NMFS 2016a). More information on CIBW habitat can be found at
https://www.fisheries.noaa.gov/action/critical-habitat-cook-inlet-beluga-whale.
Since 1993, NMFS has conducted annual aerial surveys in June, July
or August to document the distribution and abundance of beluga whales
in Cook Inlet. The collective survey results show that beluga whales
have been consistently found near or in river mouths along the northern
shores of upper Cook Inlet (i.e., north of East and West Foreland). In
particular, beluga whale groups are seen in the Susitna River Delta,
Knik Arm, and along the shores of Chickaloon Bay. Small groups had also
been recorded farther south in Kachemak Bay, Redoubt Bay (Big River),
and Trading Bay (McArthurRiver) prior to 1996 but very rarely
thereafter. Since the mid-1990s, most (96 to 100 percent) beluga whales
in upper Cook Inlet have been concentrated in shallow areas near river
mouths, no longer occurring in the central or southern portions of Cook
Inlet (Hobbs et al. 2008). Based on these aerial surveys, the
concentration of beluga whales in the northernmost portion of Cook
Inlet appears to be consistent from June to October (Rugh et al. 2000,
2004a, 2005, 2006, 2007). Research reports generated from the surveys
can be found at https://www.fisheries.noaa.gov/alaska/endangered-species-conservation/research-reports-and-publications-cook-inlet-beluga-whales.
Though CIBWs can be found throughout the inlet at any time of year,
they spend the ice-free months generally in the upper Cook Inlet,
shifting into the middle and lower Inlet in winter (Hobbs et al. 2005).
In 1999, one beluga whale was tagged with a satellite transmitter, and
its movements were recorded from June through September of that year.
Since 1999, 18 beluga whales in upper Cook Inlet have been captured and
fitted with satellite tags to provide information on their movements
during late summer, fall, winter, and spring. Using location data from
satellite-tagged Cook Inlet belugas, Ezer et al. (2013) found most
tagged whales were in the lower to middle inlet (70 to 100 percent of
tagged whales) during January through March, near the Susitna River
Delta from April to July (60 to 90 percent of tagged whales) and in the
Knik and Turnagain Arms from August to December.
More recently, the Marine Mammal Lab has conducted long-term
passive acoustic monitoring demonstrating seasonal shifts in CIBW
concentrations throughout Cook Inlet. Castellote et al. (2015)
conducted long-term acoustic monitoring at 13 locations throughout Cook
Inlet between 2008 and 2015: North Eagle Bay, Eagle River Mouth, South
Eagle Bay, Six Mile, Point MacKenzie, Cairn Point, Fire Island, Little
Susitna, Beluga River, Trading Bay, Kenai River, Tuxedni Bay, and Homer
Spit; the former six stations being located within Knik Arm. In
general, the observed seasonal distribution is in accordance with
descriptions based on aerial surveys and satellite telemetry: Beluga
detections are higher in the upper inlet during summer, peaking at
Little Susitna, Beluga River, and Eagle Bay, followed by fewer
detections at those locations during winter. Higher detections in
winter at Trading Bay, Kenai River, and Tuxedni Bay suggest a broader
beluga distribution in the lower inlet during winter.
Beluga whales in Cook Inlet are believed to mostly calve between
mid-May and mid-July, and concurrently breed between late spring and
early summer (NMFS 2016a), primarily in upper Cook Inlet. The only
known observed occurrence of calving occurred on July 20, 2015 in the
Susitna Delta area (T. McGuire, pers. comm. March 27, 2017). The first
neonates encountered during each field season from 2005 through 2015
were always seen in the Susitna River Delta in July. The photo ID
team's documentation of the dates of the first neonate of each year
indicate that calving begins in mid-late July/early August, generally
coinciding with the observed timing of annual maximum group size.
Probable mating behavior of belugas was observed in April and May of
2014, in Trading Bay. Young beluga whales are nursed for two years and
may continue to associate with their mothers for a considerable time
thereafter (Colbeck et al. 2013).
During the spring and summer, beluga whales are generally
concentrated near the warmer waters of river mouths where prey
availability is high and predator occurrence is low (Moore et al.
2000). Goetz et al. (2012b) modeled habitat preferences using NMFS'
1994-2008 June abundance survey data. In large areas, such as the
Susitna Delta (Beluga to Little Susitna Rivers) and Knik Arm, there was
a high probability that beluga whales were in larger group sizes.
Beluga whale presence also increased closer to rivers with Chinook
salmon (Oncorhynchus tshawytscha) runs, such as the Susitna River.
Movement has been correlated with the peak discharge of seven major
rivers emptying into Cook Inlet. Boat-based surveys from 2005 to the
present (McGuire and Stephens 2017), and initial results from passive
acoustic monitoring across the entire inlet (Castellote et al. 2015)
also support seasonal patterns observed with other methods. Based on
long-term passive acoustic monitoring, seasonally, foraging behavior
was more prevalent during summer, particularly at upper inlet rivers,
than during winter. Foraging index was highest at Little Susitna, with
a peak in July[hyphen]August and a secondary peak in May, followed by
Beluga River and then Eagle Bay; monthly variation in the foraging
index indicates belugas shift their foraging behavior among these three
locations from April through September.
Despite protection from hunting, this stock continues to decline.
The population was declining at the end of the period of unregulated
harvest, with the relatively steep decline ending in 1999, coincident
with harvest removals dropping from an estimated 42 in 1998 to just 0
to 2 whales per year in 2000 to 2006 (and with no removals after 2006).
From 1999 to 2016, the rate of decline of the population was estimated
to be 0.4% (SE = 0.6%) per year, with
[[Page 72164]]
a 73% probability of a population decline. While from 2006 to 2016, the
most recent 10-year period, the rate of decline was estimated to be
0.5% per year, (with a 70% probability of a population decline)
(Shelden et al. 2017). No human-caused mortality or serious injury of
CIBWs has been recently documented. Other potential threats most likely
to result in direct human-caused mortality or serious injury of this
stock include ship strikes.
Mortality related to live stranding events, where a beluga whale
group strands as the tide recedes, has been regularly observed in upper
Cook Inlet. Most whales involved in a live stranding event survive,
although some associated deaths may not be observed if the whales die
later from live-stranding-related injuries (Vos and Shelden 2005,
Burek-Huntington et al. 2015). Between 2013 and 2017, there were
reports of approximately 78 beluga whales involved in two known live
stranding events, plus one suspected live stranding event with two
associated deaths reported. In 2014, necropsy results from two whales
found in Turnagain Arm suggested that a live stranding event
contributed to their deaths as both had aspirated mud and water. No
live stranding events were reported prior to the discovery of these
dead whales, suggesting that not all live stranding events are
observed. Most live strandings occur in Knik Arm and Turnagain Arm,
which are shallow and have big tides. Another source of beluga whale
mortality in Cook Inlet is predation by transient-type (mammal-eating)
killer whales.
In its Recovery Plan (NMFS, 2016), NMFS identified several threats
to CIBWs. Potential threats include: (1) High concern: Catastrophic
events (e.g., natural disasters, spills, mass strandings), cumulative
effects of multiple stressors, and noise; (2) medium concern: Disease
agents (e.g., pathogens, parasites, and harmful algal blooms), habitat
loss or degradation, reduction in prey, and unauthorized take; and (3)
low concern: Pollution, predation, and subsistence harvest. The
recovery plan did not treat climate change as a distinct threat but
rather as a consideration in the threats of high and medium concern.
Killer Whale
Two stocks of killer whales may be present in upper Cook Inlet: The
Eastern North Pacific Alaska Residents and the Gulf of Alaska, Aleutian
Islands, and Bering Sea Transients. Both ecotypes overlap in the same
geographic area; however, they maintain social and reproductive
isolation and feed on different prey species. During aerial surveys
conducted between 1993 and 2004, killer whales were observed on only
three flights, all in the Kachemak and English Bay area (Rugh et al.
2005). Anecdotal reports of killer whales feeding on belugas in upper
Cook Inlet began increasing in the 1990s; several of these sightings
and strandings report killer whale predation on beluga Whales.
No killer whales were spotted in the vicinity of the POA during
surveys by Funk et al. (2005), Ireland et al. (2005), or Brueggeman et
al. (2007, 2008a, 2008b). No killer whale sightings were documented
during POA construction or scientific monitoring from 2005 to 2011 or
during the 2016 TPP. Very few killer whales, if any, are expected to
approach or be near the project area during construction of the PCT.
There are no reports of a subsistence harvest of killer whales in
Alaska. Based on currently available data, a minimum estimate of the
mean annual mortality and serious injury rate for both the Alaska
Residents and transient stocks due to U.S. commercial fisheries is less
than 10% of the PBR and, therefore, is considered to be insignificant
and approaching zero mortality and serious injury rate. Therefore,
neither stock is classified as a strategic stock.
Harbor Porpoise
Harbor porpoises primarily frequent the coastal waters of the Gulf
of Alaska and Southeast Alaska (Dahlheim et al. 2000, 2008), typically
occurring in waters less than 100 m deep (Hobbs and Waite 2010). Harbor
porpoise prefer nearshore areas, bays, tidal areas, and river mouths
(Dahlheim et al. 2000, Hobbs and Waite 2010). In Alaskan waters, NMFS
has designated three stocks of harbor porpoises for management
purposes: Southeast Alaska, Gulf of Alaska, and Bering Sea Stocks (Muto
et al. 2017). Porpoises found in Cook Inlet belong to the Gulf of
Alaska Stock, which is distributed from Cape Suckling to Unimak Pass.
Although harbor porpoise have been frequently observed during
aerial surveys in Cook Inlet (Shelden et al. 2014), most sightings are
of single animals, and are concentrated at Chinitna and Tuxedni Bays on
the west side of lower Cook Inlet (Rugh et al. 2005) and in the upper
inlet. The occurrence of larger numbers of porpoise in the lower Cook
Inlet may be driven by greater availability of preferred prey and
possibly less competition with beluga whales, as belugas move into
upper inlet waters to forage on Pacific salmon during the summer months
(Shelden et al. 2014).
There has been an increase in harbor porpoise sightings in upper
Cook Inlet over the past two decades (Shelden et al. 2014). Small
numbers of harbor porpoises have been consistently reported in upper
Cook Inlet between April and October (Prevel-Ramos et al. 2008). Harbor
porpoises have been observed within Knik Arm during monitoring efforts
since 2005. During POA construction from 2005 through 2011 and in 2016,
harbor porpoises were reported in 2009, 2010, and 2011 (Cornick and
Saxon-Kendall 2008, 2009; Cornick and Seagars 2016; Cornick et al.
2010, 2011; Markowitz and McGuire 2007; Prevel-Ramos et al. 2006; Table
4-2). In 2009, a total of 20 harbor porpoises were observed during
construction monitoring, with sightings in June, July, August, October,
and November. Harbor porpoises were observed twice in 2010, once in
July and again in August. In 2011, POA monitoring efforts documented
harbor porpoises five times, with a total of six individuals, in
August, October, and November at the POA (Cornick et al. 2011). During
other monitoring efforts conducted in Knik Arm, there were four
sightings of harbor porpoises in 2005 (Shelden et al. 2014), and a
single harbor porpoise was observed within the vicinity of the POA in
October 2007.
Estimates of human-caused mortality and serious injury from
stranding data and fisherman self-reports are underestimates because
not all animals strand or are self-reported nor are all stranded
animals found, reported, or have the cause of death determined. In
addition, the trend of this stock is unknown given data is more than
eight years old. Given their shallow water distribution, harbor
porpoise are vulnerable to physical modifications of nearshore habitats
resulting from urban and industrial development (including waste
management and nonpoint source runoff) and activities such as
construction of docks and other over-water structures, filling of
shallow areas, dredging, and noise (Linnenschmidt et al. 2013).
Subsistence users have not reported any harvest from the Gulf of Alaska
harbor porpoise stock since the early 1900s (Shelden et al. 2014).
Steller Sea Lion
Steller sea lions inhabiting Cook Inlet belong to the western
distinct population segment (WDPS), and this is the stock considered in
this analysis. NMFS defines the Steller sea lion WDPS as all
populations west of longitude 144[deg] W to the western end of the
Aleutian Islands. The most recent comprehensive aerial photographic and
land-based surveys of WDPS Steller sea
[[Page 72165]]
lions in Alaska were conducted during the 2014 and 2015 breeding
seasons (Fritz et al. 2015). The WDPS of Steller sea lions is currently
listed as endangered under the ESA (55 FR 49204, November 26, 1990) and
designated as depleted under the MMPA. NMFS designated critical habitat
on August 27, 1993 (58 FR 45269). The critical habitat designation for
the WDPS of Steller sea lions was determined to include a 37 km (20 nm)
buffer around all major haul outs and rookeries, and associated
terrestrial, atmospheric, and aquatic zones, plus three large offshore
foraging areas, none of which occurs in the project area. Steller sea
lions feed largely on walleye pollock, salmon, and arrowtooth flounder
during the summer, and walleye pollock and Pacific cod during the
winter (Sinclair and Zeppelin 2002). Except for salmon, none of these
are found in abundance in upper Cook Inlet (Nemeth et al. 2007).
Within Cook Inlet, Steller sea lions primarily inhabit lower Cook
Inlet. However, they occasionally venture to upper Cook Inlet and Knik
Arm. Steller sea lions have been observed near the POA in June 2009
(ICRC 2009a) and in May 2016 (Cornick and Seagars 2016). During POA
construction monitoring in June of 2009, a Steller sea lion was
documented three times (within the same day) in Knik Arm and was
believed to be the same individual (ICRC 2009a). In 2016, Steller sea
lions were observed on two separate days. On May w, 2016, one
individual was sighted. On May 25, 2016, there were five Steller sea
lion sightings within a 50-minute period, and these sightings occurred
in areas relatively close to one another suggesting they were likely
the same animal (Cornick and Seagars 2016). Steller sea lions are
likely attracted to the salmon runs; however, their presence is less
common in upper Cook Inlet than lower Cook Inlet.
The total estimated annual level of human-caused mortality and
serious injury for Western U.S. Steller sea lions in 2012-2016 was 247
sea lions: 35 in U.S. commercial fisheries, 1.2 in unknown (commercial,
recreational, or subsistence) fisheries, 2 in marine debris, 5.5 due to
other causes (arrow strike, entangled in hatchery net, illegal
shooting, Marine Mammal Protection Act (MMPA) authorized research-
related), and 203 in the Alaska Native subsistence harvest. However,
there are multiple nearshore commercial fisheries which are not
observed; thus, there is likely to be unreported fishery-related
mortality and serious injury of Steller sea lions.
Several factors may have been important drivers of the decline of
the stock. However, there is uncertainty about threats currently
impeding their recovery, particularly in the Aleutian Islands. Many
factors have been suggested as causes of the steep decline in abundance
of western Steller sea lions observed in the 1980s, including
competitive effects of fishing, environmental change, disease,
contaminants, killer whale predation, incidental take, and illegal and
legal shooting (Atkinson et al. 2008, NMFS 2008). A number of
management actions have been implemented since 1990 to promote the
recovery of the Western U.S. stock of Steller sea lions, including 3-
nmi no-entry zones around rookeries, prohibition of shooting at or near
sea lions, and regulation of fisheries for sea lion prey species (e.g.,
walleye pollock, Pacific cod, and Atka mackerel) (Sinclair et al. 2013,
Tollit et al. 2017).
Harbor Seal
Harbor seals belonging to the Cook Inlet/Shelikof Strait stock
inhabit the coastal and estuarine waters of Cook Inlet and are observed
in both upper and lower Cook Inlet throughout most of the year (Boveng
et al. 2012; Shelden et al. 2013). Recent research on satellite-tagged
harbor seals observed several movement patterns within Cook Inlet
(Boveng et al. 2012). In the fall, a portion of the harbor seals
appeared to move out of Cook Inlet and into Shelikof Strait, northern
Kodiak Island, and coastal habitats of the Alaska Peninsula. The
western coast of Cook Inlet had higher usage by harbor seals than
eastern coast habitats, and seals captured in lower Cook Inlet
generally exhibited site fidelity by remaining south of the Forelands
in lower Cook Inlet after release (Boveng et al. 2012).
The presence of harbor seals in upper Cook Inlet is seasonal.
Harbor seals are commonly observed along the Susitna River and other
tributaries within upper Cook Inlet during eulachon and salmon
migrations (NMFS 2003). The major haulout sites for harbor seals are
located in lower Cook Inlet with fewer sites in upper Cook Inlet
(Montgomery et al. 2007). In the project area (Knik Amr), harbor seals
tend to congregate near the mouth of Ship Creek (Cornick et al. 2011;
Shelden et al. 2013), likely foraging on salmon and eulachon runs.
Approximately 138 harbor seals were observed during previous POA
monitoring with sightings ranging from 3 individuals in 2008 to 59
individuals in 2011 (see Table 4-1 in POA's application).
The most current population trend estimate of the Cook Inlet/
Shelikof Strait stock is approximately -111 seals per year, with a
probability that the stock is decreasing of 0.609 (Muto et al., 2015).
The estimated level of human-caused mortality and serious injury for
this stock is 234 seals, of which 233 seals are taken for subsistence
uses. Additional potential threats most likely to result in direct
human-caused mortality or serious injury for all stocks of harbor seals
in Alaska include unmonitored subsistence harvests, incidental takes in
commercial fisheries, and illegal shooting. Disturbance by cruise
vessels is an additional threat for harbor seal stocks that occur in
glacial fjords (Jansen et al. 2010, 2015; Matthews et al. 2016). The
average annual harvest of this stock of harbor seals between 2004 and
2008 was 233 seals per year. The annual harvest in 2014 was 104 seals
(Muto et al., 2019).
In addition, sea otters (Enhydra lutris) may be found in Cook
Inlet. However, sea otters are managed by the U.S. Fish and Wildlife
Service and are not considered further in this document.
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 4.
[[Page 72166]]
Table 4--Marine Mammal Hearing Groups
[NMFS, 2018]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans 150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
whales, bottlenose whales).
High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
cephalorhynchid, Lagenorhynchus
cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) 50 Hz to 86 kHz.
(true seals).
Otariid pinnipeds (OW) (underwater) 60 Hz to 39 kHz.
(sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al. 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.
Six marine mammal species (four cetacean and two pinniped (one otariid
and one phocid) species) have the reasonable potential to co-occur with
the proposed survey activities. Please refer to Table 3. Of the
cetacean species that may be present, one is classified as a low-
frequency cetacean (i.e., all mysticete species), two are classified as
mid-frequency cetaceans (i.e., all delphinid and ziphiid species and
the sperm whale), and one is classified as a high-frequency cetacean
(i.e., harbor porpoise and Kogia spp.).
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section includes a summary and discussion of the ways that
components of the specified activity may impact marine mammals and
their habitat. The Estimated Take by Incidental Harassment section
later in this document includes a quantitative analysis of the number
of individuals that are expected to be taken by this activity. The
Negligible Impact Analysis and Determination section considers the
content of this section, the Estimated Take by Incidental Harassment
section, and the Proposed Mitigation section, to draw conclusions
regarding the likely impacts of these activities on the reproductive
success or survivorship of individuals and how those impacts on
individuals are likely to impact marine mammal species or stocks.
Description of Sound Sources--The primary relevant stressor to
marine mammals from the proposed activity is the introduction of noise
into the aquatic environment; therefore, we focus our impact analysis
on the effects of anthropogenic noise on marine mammals. To better
understand the potential impacts of exposure to pile driving noise, we
describe sound source characteristics below. Specifically, we look at
the following two ways to characterize sound: by its temporal (i.e.,
continuous or intermittent) and its pulse (i.e., impulsive or non-
impulsive) properties. Continuous sounds are those whose sound pressure
level remains above that of the ambient sound, with negligibly small
fluctuations in level (NIOSH, 1998; ANSI, 2005), while intermittent
sounds are defined as sounds with interrupted levels of low or no sound
(NIOSH, 1998). Impulsive sounds, such as those generated by impact pile
driving, are typically transient, brief (<1 sec), broadband, and
consist of a high peak pressure with rapid rise time and rapid decay
(ANSI, 1986; NIOSH, 1998). The majority of energy in pile impact pulses
is at frequencies below 500 Hz. Impulsive sounds, by definition, are
intermittent. Non-impulsive sounds, such as those generated by
vibratory pile driving, can be broadband, narrowband or tonal, brief or
prolonged, and typically do not have a high peak sound pressure with
rapid rise/decay time that impulsive sounds do (ANSI 1995; NIOSH 1998).
Non-impulsive sounds can be intermittent or continuous. Similar to
impact pile driving, vibratory pile driving generates low frequency
sounds. Vibratory pile driving is considered a non-impulsive,
continuous source. Discussion on the appropriate harassment threshold
associated with these types of sources based on these characteristics
can be found in the Estimated Take section.
Potential Effects of the Specified Activity--In general, the
effects of sounds from pile driving to marine mammals might result in
one or more of the following: Temporary or permanent hearing
impairment, non-auditory physical or physiological effects, behavioral
disturbance, and masking (Richardson et al., 1995; Gordon et al., 2004;
Nowacek et al., 2007; Southall et al., 2007). The potential for and
magnitude of these effects are dependent on several factors, including
received characteristics (e.g., age, size, depth of the animal during
exposure); the energy needed to drive the pile (usually related to pile
size, depth driven, and substrate), the standoff distance between the
pile and receiver; and the sound propagation properties of the
environment.
Impacts to marine mammals from pile driving activities are expected
to result primarily from acoustic pathways. As such, the degree of
effect is intrinsically related to the received level and duration of
the sound exposure, which are in turn influenced by the distance
between the animal and the source. The further away from the source,
the less intense the exposure should be. The substrate and depth of the
habitat affect the sound propagation properties of the environment.
Shallow environments are typically more structurally complex, which
leads to rapid sound attenuation. In addition, substrates that are soft
(e.g., sand) absorb or attenuate the sound more readily than hard
substrates (e.g., rock) which may reflect the acoustic wave. Soft
porous substrates also likely require less time to drive the pile, and
possibly less forceful equipment, which ultimately decrease the
intensity of the acoustic source.
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
[[Page 72167]]
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 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., permanent hearing
impairment, certain non-auditory physical or physiological effects)
only briefly as we do not expect that there is a reasonable likelihood
that POA's activities would result in such effects (see below for
further discussion).
NMFS defines a noise-induced threshold shift (TS) as ``a change,
usually an increase, in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level'' (NMFS, 2016). The amount of
threshold shift is customarily expressed in dB (ANSI 1995, Yost 2007).
A TS can be permanent (PTS) or temporary (TTS). As described in NMFS
(2018), there are numerous factors to consider when examining the
consequence of TS, including, but not limited to, the signal temporal
pattern (e.g., impulsive or non-impulsive), likelihood an individual
would be exposed for a long enough duration or to a high enough level
to induce a TS, the magnitude of the TS, time to recovery (seconds to
minutes or hours to days), the frequency range of the exposure (i.e.,
spectral content), the hearing and vocalization frequency range of the
exposed species relative to the signal's frequency spectrum (i.e., how
animal uses sound within the frequency band of the signal; e.g.,
Kastelein et al., 2014), and the overlap between the animal and the
source (e.g., spatial, temporal, and spectral). When analyzing the
auditory effects of noise exposure, it is often helpful to broadly
categorize sound as either impulsive--noise with high peak sound
pressure, short duration, fast rise-time, and broad frequency content--
or non-impulsive. When considering auditory effects, vibratory pile
driving is considered a non-impulsive source while impact pile driving
is treated as an impulsive source.
Permanent Threshold Shift--NMFS defines PTS as a permanent,
irreversible increase in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS 2018). Available data from
humans and other terrestrial mammals indicate that a 40 dB threshold
shift approximates PTS onset (see NMFS 2018 for review).
Temporary Threshold Shift--NMFS defines TTS as a temporary,
reversible increase in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS 2018). Based on data from
cetacean TTS measurements (see Finneran 2014 for a review), a TTS of 6
dB is considered the minimum threshold shift clearly larger than any
day-to-day or session-to-session variation in a subject's normal
hearing ability (Schlundt et al., 2000; Finneran et al., 2000; Finneran
et al., 2002).
Depending on the degree (elevation of threshold in dB), duration
(i.e., recovery time), and frequency range of TTS, and the context in
which it is experienced, TTS can have effects on marine mammals ranging
from discountable to serious (similar to those discussed in auditory
masking, below). For example, a marine mammal may be able to readily
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal
is traveling through the open ocean, where ambient noise is lower and
there are not as many competing sounds present. Alternatively, a larger
amount and longer duration of TTS sustained during time when
communication is critical for successful mother/calf interactions could
have more serious impacts. We note that reduced hearing sensitivity as
a simple function of aging has been observed in marine mammals, as well
as humans and other taxa (Southall et al., 2007), so we can infer that
strategies exist for coping with this condition to some degree, though
likely not without cost.
Schlundt et al. (2000) performed a study exposing five bottlenose
dolphins and two belugas (same individuals as Finneran's studies) to
intense 1 second tones at different frequencies. The resulting levels
of fatiguing stimuli necessary to induce 6 dB or larger masked TTSs
were generally between 192 and 201 dB re: 1 microPascal ([mu]Pa).
Dolphins began to exhibit altered behavior at levels of 178-193 dB re:
1[mu]Pa and above; belugas displayed altered behavior at 180-196 dB re:
1 [mu]Pa and above. At the conclusion of the study, all thresholds were
at baseline values.
There are a limited number of studies investigating the potential
for cetacean TTS from pile driving and only one has elicited a small
amount of TTS in a single harbor porpoise individual (Kastelein et al.,
2015). However, captive bottlenose dolphins and beluga whales have
exhibited changes in behavior when exposed to pulsed sounds (Finneran
et al., 2000, 2002, 2005). The animals tolerated high received levels
of sound before exhibiting aversive behaviors. Experiments on a beluga
whale showed that exposure to a single watergun impulse at a received
level of 207 kPa (30 psi) p-p, which is equivalent to 228 dB p-p,
resulted in a 7 and 6 dB TTS in the beluga whale at 0.4 and 30 kHz,
respectively. Thresholds returned to within 2 dB of the pre-exposure
level within four minutes of the exposure (Finneran et al., 2002).
Although the source level of pile driving from one hammer strike is
expected to be lower than the single watergun impulse cited here,
animals being exposed for a prolonged period to repeated hammer strikes
could receive more sound exposure in terms of SEL than from the single
watergun impulse (estimated at 188 dB re 1 [mu]Pa\2\-s) in the
aforementioned experiment (Finneran et al., 2002). Results of these
studies suggest odontocetes are susceptible to TTS from pile driving,
but that they seem to recover quickly from at least small amounts of
TTS.
Behavioral Harassment--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. Disturbance may result in changing durations
of surfacing and dives, number of blows per surfacing, or moving
direction and/or speed; reduced/increased vocal activities; changing/
cessation of certain behavioral activities (such as socializing or
feeding); visible startle response or aggressive behavior (such as
tail/fluke slapping or jaw clapping); avoidance of areas where sound
sources are located. Pinnipeds may increase their haul out time,
possibly to avoid in-water disturbance (Thorson and Reyff 2006).
Behavioral responses to sound are highly variable and context-specific
and any reactions depend on numerous intrinsic and extrinsic factors
(e.g., species, state of maturity, experience, current activity,
reproductive state, auditory sensitivity, time of day), as well as the
interplay between factors
[[Page 72168]]
(e.g., Richardson et al. 1995; Wartzok et al. 2003; Southall et al.
2007; Weilgart 2007; Archer et al. 2010). Behavioral reactions can vary
not only among individuals but also within an individual, depending on
previous experience with a sound source, context, and numerous other
factors (Ellison et al. 2012), and can vary depending on
characteristics associated with the sound source (e.g., whether it is
moving or stationary, number of sources, distance from the source). In
general, pinnipeds seem more tolerant of, or at least habituate more
quickly to, potentially disturbing underwater sound than do cetaceans,
and generally seem to be less responsive to exposure to industrial
sound than most cetaceans. Please see Appendices B-C of Southall et al.
(2007) for a review of studies involving marine mammal behavioral
responses to sound.
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 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 above, 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 seismic 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).
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,b). 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, 2005b, 2006; Gailey et
al., 2007).
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
(Eubalaena glacialis) 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., 2007b). 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
(Eschrictius robustus) are known to change direction--deflecting from
customary migratory paths--in order to avoid noise from seismic 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
[[Page 72169]]
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.
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).
Specific to CIBWs, we have several years of marine mammal
monitoring data demonstrating the behavioral responses to pile driving
at the POA. Previous pile driving activities range from the
installation and removal of sheet pile driving to installation of 48-in
pipe piles with both vibratory and impact hammers. Kendell and Cornick
(2016) provide a comprehensive overview of four years of scientific
marine mammal monitoring conducted during the POA's Expansion Project.
These were observations made independent of pile driving activities
(i.e., not construction based PSOs). The authors investigated beluga
whale behavior before and during pile driving activity at the POA.
Sighting rates, mean sighting duration, behavior, mean group size,
group composition, and group formation were compared between the two
periods. A total of about 2,329 h of sampling effort was completed
across 349 d from 2005 to 2009. Overall, 687 whales in 177 groups were
documented during the 69 days that whales were sighted. A total of 353
and 1,663 h of pile driving activity took place in 2008 and 2009,
respectively. There was no relationship between monthly beluga whale
sighting rates and monthly pile driving rates (r = 0.19, p = 0.37).
Sighting rates before (n = 12; 0.06 0.01) and during (n =
13; 0.01 0.03) pile driving activity were not
significantly different. However, sighting duration of beluga whales
decreased significantly during pile driving (39 6 min
before and 18 3 min during). There were also significant
differences in behavior before versus during pile driving. Beluga
whales primarily traveled through the study area both before and during
pile driving; however, traveling increased relative to other behaviors
during pile driving activity. Suspected feeding decreased during pile
driving although the sample
[[Page 72170]]
size was low as feeding was observed on only two occasions before pile
driving and on zero occasions during pile driving. Documentation of
milling began in 2008 and was observed on 21 occasions. No acute
behavioral responses were documented. Mean group size decreased during
pile driving; however, this difference was not statistically
significant. There were significant differences in group composition
before and during pile driving ship between monthly beluga whale
sighting rates and monthly pile driving rates with more white (i.e.,
older) animals being present during pile driving.
Acoustically, Kendall et al. (2013) only recorded echolocation
clicks and no whistles or noisy vocalizations near construction
activity at the POA. Beluga whales have been occasionally documented to
forage around Ship Creek (south of the POA) but, during pile driving,
may choose to move past the POA to other, potentially richer, feeding
areas further into Knik Arm (e.g., Six Mile Creek, Eagle River, Eklutna
River). These locations contain predictable salmon runs (ADFG, 2010),
an important food source for CIBWss (NMFS1), and the timing of these
runs has been correlated with beluga whale movements into the upper
reaches of Knik Arm (Ezer et al., 2013).
Auditory Masking
Since many marine mammals rely on sound to find prey, moderate
social interactions, and facilitate mating (Tyack, 2008), noise from
anthropogenic sound sources can interfere with these functions, but
only if the noise spectrum overlaps with the hearing sensitivity of the
marine mammal (Southall et al., 2007; Clark et al., 2009; Hatch et al.,
2012). Chronic exposure to excessive, though not high-intensity, noise
could cause masking at particular frequencies for marine mammals that
utilize sound for vital biological functions (Clark et al., 2009).
Acoustic masking is when other noises such as from human sources
interfere with animal detection of acoustic signals such as
communication calls, echolocation sounds, and environmental sounds
important to marine mammals. Therefore, under certain circumstances,
marine mammals whose acoustical sensors or environment are being
severely masked could also be impaired from maximizing their
performance fitness in survival and reproduction.
Masking, which can occur over large temporal and spatial scales,
can potentially affect the species at population, community, or even
ecosystem levels, as well as individual levels. Masking affects both
senders and receivers of the signals and could have long-term chronic
effects on marine mammal species and populations. Masking occurs at the
frequency band which the animals utilize so the frequency range of the
potentially masking sound is important in determining any potential
behavioral impacts. Pile driving generates low frequency sounds;
therefore, mysticete foraging is likely more affected than odontocetes
given very high frequency echolocation clicks (typically associated
with odontocete foraging) are likely unmasked to any significant
degree. However, lower frequency man-made sounds may affect
communication signals when they occur near the sound band and thus
reduce the communication space of animals (e.g., Clark et al., 2009)
and cause increased stress levels (e.g., Foote et al., 2004; Holt et
al., 2009).
Moreover, even within a given species, different types of man-made
noises may results in varying degrees of masking. For example, Erbe et
al. (1999) and Erbe (2000), analyzed the effect of masking of beluga
calls by exposing a trained beluga to icebreaker propeller noise, an
icebreaker's bubbler system, and ambient Arctic ice cracking noise, and
found that the latter was the least problematic for the whale detecting
the calls. Sheifele et al. (2005) studied a population of belugas in
the SLE to determine whether beluga vocalizations showed intensity
changes in response to shipping noise. This type of behavior has been
observed in humans and is known as the Lombard vocal response (Lombard
1911). Sheifele et al. (2005) demonstrated that shipping noise did
cause belugas to vocalize louder. The acoustic behavior of this same
population of belugas was studied in the presence of ferry and small
boat noise. Lesage et al. (1999) described more persistent vocal
responses when whales were exposed to the ferry than to the small-boat
noise. These included a progressive reduction in calling rate while
vessels were approaching, an increase in the repetition of specific
calls, and a shift to higher frequency bands used by vocalizing animals
when vessels were close to the whales. The authors concluded that these
changes, and the reduction in calling rate to almost silence, may
reduce communication efficiency which is critical for a species of a
gregarious nature. However, the authors also stated that because of the
gregarious nature of belugas, this ``would not pose a serious problem
for intraherd communication'' of belugas given the short distance
between group members, and concluded a noise source would have to be
very close to potentially limit any communication within the beluga
group (Lesage et al. 1999). However, increasing the intensity or
repetition rate, or shifting to higher frequencies when exposed to
shipping noise (from merchant, whale watching, ferry and small boats),
is indicative of an increase of energy costs (Bradbury and Vehrencamp
1998).
Marine mammals in Cook Inlet are continuously exposed to
anthropogenic noise which may lead to some habituation but is also a
source of masking. A subsample (8,756 hours) of the acoustic recordings
collected by the Cook Inlet Beluga Acoustics research program in Cook
Inlet, Alaska, from July 2008 to May 2013, were analyzed to describe
anthropogenic sources of underwater noise, acoustic characteristics,
and frequency of occurrence and evaluate the potential for acoustic
impact to Cook Inlet belugas. As described in Castellote et al. (2016),
a total of 13 sources of noise were identified: Commerical ship,
dredging, helicopter, jet aircraft (commercial or non-fighter), jet
aircraft (military fighter), outboard engine (small skiffs, rafts),
pile driving, propeller aircraft, sub-bottom profiler, unclassified
machinery (continuous mechanical sound; e.g., engine), unidentified
`clank' or `bang' (impulsive mechanical sound; e.g., barge dumping),
unidentified (unclassifiable anthropogenic sound), unknown up- or down-
sweep (modulated tone of mechanical origin; e.g., hydraulics). A total
of 6,263 anthropogenic acoustic events were detected and classified,
which had a total duration of 1,025 hours and represented 11.7% of the
sound recordings analyzed. There was strong variability in source
diversity, loudness, distribution, and seasonal occurrence of noise,
which reflects the many different activities within the Cook Inlet.
Cairn Point was the location where the loudness and duration of
commercial ship noise events were most concentrated, due to activities
at the POA. This specific source of anthropogenic noise was present in
the recordings from all months analyzed, with highest levels in August.
In addition to the concentrated shipping noise at Cairn Point, a
combination of unknown noiseclasses occurred in this area, particularly
during summer. Specifically, unknown up or down sweeps, unidentified,
unclassed machinery, and unidentified clank or bang noise classes were
all documented. In contrast, Eagle River (north of the
[[Page 72171]]
POA and where CIBWs concentrate to forage) was the quietest of all
sampled locations.
Potential Pile Driving Effects on Prey--Pile driving produces
continuous, non-impulsive (i.e., vibratory pile driving) sounds and
intermittent, pulsed (i.e., impact driving) sounds. Fish react to
sounds that are especially strong and/or intermittent low-frequency
sounds. Short duration, sharp sounds can cause overt or subtle changes
in fish behavior and local distribution. Hastings and Popper (2005)
identified several studies that suggest fish may relocate to avoid
certain areas of sound energy. Additional studies have documented
effects of pile driving on fish, although several are based on studies
in support of large, multiyear bridge construction projects (e.g.,
Scholik and Yan, 2001, 2002; Popper and Hastings, 2009). SPLs of
sufficient strength have been known to cause injury to fish and fish
mortality (summarized in Popper et al. 2014). The most likely impact to
fish from pile driving activities at the project area would be
temporary behavioral avoidance of the area. The duration of fish
avoidance of this area after pile driving stops is unknown, but a rapid
return to normal recruitment, distribution and behavior is anticipated.
As discussed in the Marine Mammal section above, NMFS designated
CIBW critical habitat in Knik Arm. Knik Arm is Type 1 habitat for the
CIBWs, which means it is the most valuable, used intensively by beluga
whales from spring through fall for foraging and nursery habitat.
However, the POA, the adjacent navigation channel, and the turning
basin were excluded from critical habitat designation due to national
security concerns (76 FR 20180, April 11, 2011). Foraging primarily
occurs at river mouths (e.g., Susitna Delta, Eagle River flats) which
are unlikely to be influenced by pile driving activities. The Susitna
Delta is more than 20 km from the POA and Cairn Point is likely to
impede any pile driving noise from propagating into northern Knik Arm.
Acoustic habitat is the soundscape which encompasses all of the
sound present in a particular location and time, as a whole, when
considered from the perspective of the animals experiencing it. Animals
produce sound for, or listen for sounds produced by, conspecifics
(communication during feeding, mating, and other social activities),
other animals (finding prey or avoiding predators) and the physical
environment (finding suitable habitats, navigating). Together, sounds
made by animals and the geophysical environment (e.g., produced by
earthquakes, lightning, wind, rain, waves) make up the natural
contributions to the total acoustics of a place. These acoustic
conditions, termed acoustic habitat, are one attribute of an animal's
total habitat. Soundscapes are also defined by, and acoustic habitat
influenced by, the total contribution of anthropogenic sound. This may
include incidental emissions from sources such as vessel traffic or may
be intentionally introduced to the marine environment for data
acquisition purposes (as in the use of airgun arrays or other sources).
Anthropogenic noise varies widely in its frequency content, duration,
and loudness and these characteristics greatly influence the potential
habitat-mediated effects to marine mammals (please see also the
previous discussion on masking under ``Acoustic Effects''), which may
range from local effects for brief periods of time to chronic effects
over large areas and for long durations. Depending on the extent of
effects to habitat, animals may alter their communications signals
(thereby potentially expending additional energy) or miss acoustic cues
(either conspecific or adventitious). For more detail on these concepts
see, e.g., Barber et al., 2010; Pijanowski et al. 2011; Francis and
Barber 2013; Lillis et al. 2014.
Beluga foraging habitat is limited at the POA given the highly
industrialized area. However, foraging habitat exists near the POA,
including Ship Creek and to the north of Cairn Point. Potential impacts
to foraging habitat include increased turbidity and elevation in noise
levels during pile driving. Because the POA is replacing an existing
terminal, permanent impacts from the presence of structures is
negligible. Here, we focus on construction impacts such as increased
turbidity and reference the section on acoustic habitat impacts above.
Pile installation may temporarily increase turbidity resulting from
suspended sediments. Any increases would be temporary, localized, and
minimal. POA must comply with state water quality standards during
these operations by limiting the extent of turbidity to the immediate
project area. In general, turbidity associated with pile installation
is localized to about a 25-foot (7.6 m) radius around the pile (Everitt
et al. 1980). Cetaceans are not expected to be close enough to the
project activity areas to experience effects of turbidity, and any
small cetaceans and pinnipeds could avoid localized areas of turbidity.
Therefore, the impact from increased turbidity levels is expected to be
discountable to marine mammals. No impacts to Ship Creek or critical
CIBW foraging habitats are anticipated.
In summary, activities associated with the proposed PCT project are
not likely to have a permanent, adverse effect on marine mammal habitat
or populations of fish species or on the quality of acoustic habitat.
Marine mammals may choose to not forage in close proximity to the PCT
site during pile driving; however, the POA is not a critical foraging
location for any marine mammal species. As discussed above, harbor
seals primarily use Ship Creek as foraging habitat within Knik Arm.
Beluga whales utilize Eagle Bay and rivers north of the POA which are
not expected to be ensonified by the PCT project. Therefore, no impacts
to critical foraging grounds are anticipated.
Estimated Take
This section provides an estimate of the number of incidental takes
proposed for authorization through this IHA, which will inform both
NMFS' consideration of ``small numbers'' and the negligible impact
determination.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes would primarily be by Level B harassment, as pile
driving has the potential to result in disruption of behavioral
patterns for individual marine mammals. There is also some potential
for auditory injury (Level A harassment) to result, primarily for
mysticetes, high frequency species, and phocids because predicted
auditory injury zones are larger than for mid-frequency species and
otariids. Auditory injury is unlikely to occur for mid-frequency
species and otariids. The proposed mitigation and monitoring measures
are expected to minimize the severity of such taking to the extent
practicable.
As described previously, no mortality is anticipated or proposed to
be authorized for this activity. Below we describe how the take is
estimated.
Generally speaking, we estimate take by considering: (1) Acoustic
thresholds above which NMFS believes the best available science
indicates marine
[[Page 72172]]
mammals will be behaviorally harassed or incur some degree of permanent
hearing impairment; (2) the area or volume of water that will be
ensonified above these levels in a day; (3) the density or occurrence
of marine mammals within these ensonified areas; and, (4) and the
number of days of activities. We note that while these basic factors
can contribute to a basic calculation to provide an initial prediction
of takes, additional information that can qualitatively inform take
estimates is also sometimes available (e.g., previous monitoring
results or average group size). Below, we describe the factors
considered here in more detail and present the proposed take estimate.
Acoustic Thresholds
Using the best available science, NMFS has developed acoustic
thresholds that identify the received level of underwater sound above
which exposed marine mammals would be reasonably expected to be
behaviorally harassed (equated to Level B harassment) or to incur PTS
of some degree (equated to Level A harassment).
Level B harassment for non-explosive sources--Though significantly
driven by received level, the onset of behavioral disturbance from
anthropogenic noise exposure is also informed to varying degrees by
other factors related to the source (e.g., frequency, predictability,
duty cycle), the environment (e.g., bathymetry), and the receiving
animals (hearing, motivation, experience, demography, behavioral
context) and can be difficult to predict (Southall et al., 2007,
Ellison et al., 2012). Based on what the available science indicates
and the practical need to use a threshold based on a factor that is
both predictable and measurable for most activities, NMFS uses a
generalized acoustic threshold based on received level to estimate the
onset of behavioral harassment. In general, NMFS predicts that marine
mammals are likely to be behaviorally harassed in a manner we consider
Level B harassment when exposed to underwater anthropogenic noise above
received levels of 120 dB re 1 [mu]Pa (rms) for continuous (e.g.,
vibratory pile-driving, drilling) and above 160 dB re 1 [mu]Pa (rms)
for non-explosive impulsive (e.g., seismic airguns) or intermittent
(e.g., scientific sonar) sources. However, ambient noise levels within
Knik Arm are above the 120-dB threshold, and therefore, for purposes of
this analysis, NMFS considers received levels above those of the
measured ambient noise (122.2 dB) to constitute Level B harassment of
marine mammals incidental to continuous noise, including vibratory pile
driving.
Results from the most recent acoustic monitoring conducted at the
port are presented in Austin et al. (2016) and Denes et al. (2016)
wherein noise levels were measured in absence of pile driving from May
27 through May 30, 2016 at two locations: Ambient-Dock and Ambient-
Offshore. NMFS considers the median sound levels to be most appropriate
when considering background noise levels for purposes of evaluating the
potential impacts of the POA's PCT Project on marine mammals. By using
median value, which is the 50th percentile of the measurements, for
ambient noise level, one will be able to eliminate the few transient
loud identifiable events that do not represent the true ambient
condition of the area. This is relevant because during two of the four
days (50 percent) when background measurement data were being
collected, the U.S. Army Corps of Engineers was dredging Terminal 3
(located just north of the Ambient-Offshore hydrophone) for 24 hours
per day with two 1-hour breaks for crew change. On the last two days of
data collection, no dredging was occurring. Therefore, the median
provides a better representation of background noise levels when the
PCT project would be occurring. With regard to spatial considerations
of the measurements, the Ambient-Offshore location is most applicable
to this discussion as it is complies with the NMFS 2012 memo discussed
above. The median ambient noise level collected over four days at the
end of May at the Ambient-Offshore hydrophone was 122.2 dB. We note the
Ambient-Dock location was quieter, with a median of 117 dB; however,
that hydrophone was placed very close to the dock and not where we
would expect Level B harassment to occur given mitigation measures
(e.g., shut downs). If additional data collected in the future warrant
revisiting this issue, NMFS may adjust the 122.2 dB rms Level B
harassment threshold.
Level A harassment for non-explosive sources--NMFS' Technical
Guidance for Assessing the Effects of Anthropogenic Sound on Marine
Mammal Hearing (Version 2.0) (Technical Guidance, 2018) identifies dual
criteria to assess auditory injury (Level A harassment) to five
different marine mammal groups (based on hearing sensitivity) as a
result of exposure to noise from two different types of sources
(impulsive or non-impulsive). The POA's proposed activity includes the
use of impulsive (impact pile driving) and non-impulsive (vibratory
pile driving) sources.
These thresholds are provided in Table 5 below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS 2018 Technical Guidance, which may be accessed at
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 5--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Lpk,flat: 219 dB; LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Lpk,flat: 230 dB; LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Lpk,flat: 202 dB; LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Lpk,flat: 218 dB; LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Lpk,flat: 232 dB; LE,OW,24h: 219 dB.
LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
[[Page 72173]]
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that will feed into identifying the area ensonified above the
acoustic thresholds, which include source levels and transmission loss
coefficient.
The estimated sound source levels and transmission loss coefficient
used in our analysis are based on direct measurements during
installation of unattenuated 48-in piles during the POA's 2016 TPP and
measurements collected during marine construction projects conducted by
the U.S. Navy. All source levels used in our analysis are presented in
Table 6.
Table 6--Estimated Sound Source Level With and Without a Bubble Curtain
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sound Level at 10 m
------------------------------------------------------------------------------------------------
Method and pile size Unattenuated \1\
Bubble curtain Data source
------------------------------------------------------------------------------------------------
Vibratory db rms
7 dB reduction, dB rms
--------------------------------------------------------------------------------------------------------------------------------------------------------
144-in............................ 178
171 Caltrans 2015.
48-in............................. 168
161 Austin et al.
2016
36-in............................. 166
159 Navy 2015.
24-in............................. 161
154 Navy 2015.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unattenuated \1\
Bubble curtain ..............
------------------------------------------------------------------------------------------------
Impact dB rms dB SEL dB peak dB rms dB SEL dB peak
--------------------------------------------------------------------------------------------------------------------------------------------------------
144-in............................ 209 198 220 202 191 213 Caltrans 2015.
48-in............................. 200 187 215 193 180 208 Austin et al. 2016.
36-in............................. 194 184 211 187 177 204 Navy 2015.
24-in............................. 193 181 210 186 174 203 Navy 2015.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ We note the only piles that may be driven or removed without a bubble curtain are 24-in battered piles. We included unattenuated SLs here for 36-in,
48-in, and 144-in piles to demonstrate how the 7dB reduction for bubble curtains was applied.
During the TPP, JASCO computed transmission loss (TL) coefficients,
derived from fits of the received sound level data versus range. TL
coefficients varied between piles with values ranging from 13 to 19.2
for impact pile driving and from 12.6 to 17.9 for vibratory pile
driving when using sound attenuation devices. Results for the
unattenuated hydraulic impact hammer yielded the highest TL
coefficient, 19.2, indicating that sounds from the hydraulic impact
hammer decayed most rapidly with range compared to the other hammers.
The TL coefficient for the unattenuated diesel impact hammer averaged
17.5. Sounds from the unattenuated vibratory hammer had the lowest TL
coefficient, with values of 16.1 and 16.9.
Based on these data, the POA proposed different transmission loss
rates depending on if SEL (used for Level A harassment) or rms (used
for Level B harassment) values were being evaluated. SPLrms is a
pressure metric and SEL an energy metric. The difference in TL
coefficient is a reflection of how SPLrms or SEL is dissipated in the
marine environment. During underwater sound propagation, pressure
amplitude tends to suffer more loss due to multipath propagation and
reverberation, while acoustic energy does not dissipate as rapidly.
Accordingly, the POA proposed using TL rate of 16.85 for assessing
potential for Level A harassment from impact pile driving but a TL rate
of 18.35, based on Austin et al. (2016), when assessing potential for
Level B harassment from impact pile driving. For vibratory pile
driving, SPLrms is used for both Level A harassment and Level B
harassment analysis and, based on Austin et al. (2016), the POA applied
a TL rate of 16.5. NMFS found these transmission loss rates acceptable
and carried them forward in our analysis.
When the NMFS Technical Guidance (2016) was published, in
recognition of the fact that ensonified area/volume could be more
technically challenging to predict because of the duration component in
the new thresholds, we developed a User Spreadsheet that includes tools
to help predict a simple isopleth that can be used in conjunction with
marine mammal density or occurrence to help predict takes. We note that
because of some of the assumptions included in the methods used for
these tools, we anticipate that isopleths produced are typically going
to be overestimates of some degree, which may result in some degree of
overestimate of Level A harassment take. However, these tools offer the
best way to predict appropriate isopleths when more sophisticated 3D
modeling methods are not available, and NMFS continues to develop ways
to quantitatively refine these tools, and will qualitatively address
the output where appropriate. For stationary sources (such as pile
driving), 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.
The User Spreadsheet also includes a default, single frequency
weighting factor adjustment (WFA) to account for frequency hearing
groups. During the 2016 TPP, the POA collected direct measurements of
sound generated
[[Page 72174]]
during installation of 48-in piles. The spectra associated with impact
and vibratory driving 48-in unattenuated piles was also derived.
Therefore, we accepted POA's applied spectra approach for 48-in piles
but relied on the User Spreadsheet default WFA for all other pile
sizes.
Inputs used in the User Spreadsheet for 24-in, 36-in and 144-in
piles, and the resulting isopleths are reported in Table 7.
Table 7--NMFS User Spreadsheet Inputs
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in (unattenuated) 24-in (bubble curtain) 36-in (bubble 48-in (bubble 144-in (bubble
------------------------------------------------ curtain) curtain) curtain)
Spreadsheet Tab Used --------------------------------------------------------------------
(E.1) Impact pile (E.1) Impact pile (E.1) Impact pile (E.1) Impact pile (E.1) Impact pile
driving driving driving driving driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
User Spreadsheet Input: Impact Pile Driving (TL = 16.85)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source Level (Single Strike/shot 181................... 174................... 177.................. 180.................. 191
SEL).
Weighting Factor Adjustment (kHz).. 2..................... 2..................... 2.................... measured spectra..... 2
Number of strikes pile............. 100................... 100................... 3,000................ 2,300 or 3,000....... 5,000
Piles per day...................... 5..................... 5..................... 1-3.................. 1-3.................. 0.3 or 0.7
--------------------------------------------------------------------------------------------------------------------------------------------------------
User Spreadsheet Input: Vibratory Pile Driving (TL = 16.5)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used (A) Non-Impul, Stat, (A) Non-Impul, Stat, (A) Non-Impul, Stat, (A) Non-Impul, Stat, (A) Non-Impul, Stat,
Cont. Cont. Cont. Cont. Cont.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source Level (SPL RMS)............. 161................... 154................... 159.................. 171.................. 171
Weighting Factor Adjustment (kHz).. 2.5................... 2.5................... 2.5.................. measured spectra..... 2.5
Time to drive single pile (minutes) 75.................... 100................... 75................... 30................... 45
Piles per day...................... 1-5................... 1-3................... 1-3.................. 1.................... 1
--------------------------------------------------------------------------------------------------------------------------------------------------------
To calculate the Level B harassment isopleths, NMFS considered
SPLrms source levels and the corresponding TL coefficients of 18.35 and
16.5 for impact and vibratory pile driving, respectively. The resulting
Level A harassment and Level B harassment isopleths are presented in
Table 8.
Table 8--Distances to Level A Harassment, by Hearing Group, and Level B Harassment Thresholds per Pile Type and Installation Method
--------------------------------------------------------------------------------------------------------------------------------------------------------
Piles Level A harassment (m) Level B
Pile size Hammer type Attenuation installed/ -------------------------------------------------- harassment
day LF MF HF PW OW (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
48-in (2,300 strikes per pile)... Impact.............. Bubble Curtain..... 1 655 34 766 376 36 629
2 989 51 1156 567 55 ...........
3 1258 65 1470 721 70 ...........
48-in (3,000 strikes per pile)... Impact.............. Bubble Curtain..... 1 767 39 897 440 43 629
2 1158 59 1353 664 64 ...........
3 1473 76 1721 844 82 ...........
48-in............................ Vibratory........... Bubble Curtain..... 1 5 1 7 3 0 2,247
36-in............................ Vibratory........... Bubble Curtain..... 3 12 1 17 8 1 1,699
4 14 2 20 9 1 ...........
Impact.............. Bubble Curtain..... 1 509 26 595 292 28 296
2 768 39 898 440 43 ...........
3 978 50 1142 560 54 ...........
24-in............................ Vibratory........... Bubble Curtain..... 3 3 0 5 2 0 846
4 7 1 10 4 0 ...........
Unattenuated....... 3 9 1 13 6 1 2,247
4 19 2 27 12 1 ...........
Impact.............. Bubble Curtain..... 5 77 4 90 44 4 261
Unattenuated....... 5 304 16 355 174 17 629
144-in........................... Impact.............. Bubble Curtain..... 0.3 2286 117 2672 1311 127 1,945
0.7 3781 194 4418 2167 210 1,945
Vibratory........... ................... 1 24 3 34 15 1 9,069
--------------------------------------------------------------------------------------------------------------------------------------------------------
Marine Mammal Occurrence and Take Estimation
In this section we provide the information about the presence,
density, or group dynamics of marine mammals and present take
calculations.
For all species of cetaceans other than beluga whales, density data
is not available for upper Cook Inlet. Therefore, the POA relied on
marine mammal monitoring data collected during past POA projects. These
data cover the construction season (April through November) across
multiple years. Estimated exposure from pile installation for all
marine mammals except beluga whales is calculated by the following
equation: Exposure estimate = N * # days of pile installation, where: N
= highest daily abundance estimate for each species in project area
across all years of data.
[[Page 72175]]
Harbor Seals
Marine mammal monitoring data collected during from previous POA
projects were used to estimate daily sighting rates for harbor seals in
the project area. The highest individual sighting rate recorded for a
previous year was used to quantify take of harbor seals for pile
installation associated with the PCT. The number of sightings of harbor
seals during 2016 TPP construction monitoring was 28 sightings recorded
over 83.5 hours of monitoring from May 3 through June 21, 2016. Based
on these observations, the sighting rate during the 2016 TPP
construction monitoring period was one harbor seal every 3 hours, or
approximately four harbor seals per 12-hour work day. Given projected
positive population growth, it is anticipated that eight harbor seals
may be observed, and potentially exposed to noise, per 12-hour work
day.
Pile installation and removal is anticipated to take approximately
127 days for Phase 1 and 75 days for Phase 2. Therefore, we estimate
that no more than 1,016 harbor seals during Phase 1 (8 harbor seals per
day * 127 days) plus 600 harbor seals (8 harbor seals per day * 75
days) during Phase 2, for a total of 1,616 harbor seals, would be
potentially exposed to in-water noise levels exceeding the Level B
harassment thresholds for pile installation/removal during PCT
construction.
The mouth of Ship Creek, where harbor seals tend to concentrate is
located approximately 700 m from the southern end of the PCT, and is
therefore located outside the harbor seals Level A zone for the
majority of pile sizes for both impact and vibratory pile installation.
However, there is potential for Level A harassment near Ship Creek
during installation of three 48-in piles per day and installation of
144-in piles. We estimate 30 percent of the Level B exposures could
result in Level A harassment which is similar to the proportion of work
where the Level A harassment isopleth extend to Ship Creek. Therefore,
the POA has requested, and NMFS proposes to authorize 305 Level A
harassment and 711 Level B harassment takes in Phase 1 and 180 Level A
harassment and 420 Level B harassment takes in Phase 2.
Steller Sea Lions
Steller sea lions are anticipated to be encountered in low numbers,
if at all, within the project area. Three sightings of what was likely
a single individual occurred in the project area in 2009 and two
sightings occurred in 2016. Based on observations in 2016, we
anticipate an exposure rate of 2 individuals every 19 days during PCT
pile installation and removal. Based on this rate, the POA requested 13
sea lions takes during Phase 1 (127 days * [2 sea lions every 19 days])
and 8 Steller sea lion takes during Phase 2 (75 days for Phase 2 * [2
sea lions every 19 days]). During installation of 144-in piles (Phase
2), the Level A harassment isopleth extends beyond 100 m. Although
Steller sea lions are readily detectable at these distances, we are not
proposing the POA be required to shut down if a Steller sea lion is
observed. Steller sea lions are rarely present in Knik Arm; however,
they can linger in the area for multiple days. During Phase 1, the
Level A harassment isopleth is less than the 100 m shutdown zone for
all scenarios; therefore, the potential for Level A take is negligible.
During installation of the 144-in piles in Phase 2, there is a low
potential for Level A harassment and an animal may remain for a couple
days; therefore, we allocate two takes in Phase 2 to Level A
harassment.
Harbor Porpoise
Previous monitoring data at the POA were used to evaluate daily
sighting rates for harbor porpoises in the project area. During most
years of monitoring, no harbor porpoises were observed. The highest
individual sighting rate for any recorded year during pile installation
and removal associated with the PCT was an average of 0.09 harbor
porpoises per day during 2009 construction monitoring, but this value
may not account for increased sightings in Upper Cook Inlet (Shelden et
al. 2014). Therefore, the POA assumed that one harbor porpoise could be
observed every 2 days of pile driving. Based on this assumption, the
POA has requested, and NMFS is proposing to authorize, 64 exposures
during Phase 1 (127 days * [1 harbor porpoise every 2 days]) and 38
harbor porpoises during Phase 2 (75 days for Phase 2 * [1 harbor
porpoise every 2 days]). This estimate also covers the possibility that
larger groups (2-3 individuals) of harbor porpoise could occur
occasionally.
Harbor porpoises are relatively small cetaceans that move at high
velocities, which can make their detection and identification at great
distances difficult. Using the NMFS User Spreadsheet, impact driving
36-in, 48-in and 144-in piles results in Level A harassment isopleths
larger than the Level B harassment isopleth. Vibratory driving and
removal result in much smaller Level B harassment zone than Level B
harassment zones and many temporary piles (the bulk of the work) would
be installed and removed with a vibratory hammer. Further, the Level A
harassment isopleths consider long durations and harbor porpoise are
likely moving through the area, if present, not lingering. Therefore,
we propose to authorize approximately one-third of the expected take to
Level A harassment. For Phase 1, we are proposing to authorize 21 takes
by Level A harassment and 43 takes by Level B harassment. For Phase 2,
we propose to authorize 13 Level A harassment and 25 Level B harassment
takes.
Killer Whales
Few, if any, killer whales are expected to approach the project
area. No killer whales were sighted during previous monitoring programs
for the Knik Arm Crossing and POA construction projects, including the
2016 TPP. The infrequent sightings of killer whales that are reported
in upper Cook Inlet tend to occur when their primary prey (anadromous
fish for resident killer whales and beluga whales for transient killer
whales) are also in the area (Shelden et al. 2003). Previous sightings
of transient killer whales have documented pod sizes in upper Cook
Inlet between one and six individuals (Shelden et al. 2003). The
potential for exposure of killer whales within the Level B harassment
isopleths is anticipated to be extremely low. Level B take is
conservatively estimated at no more than 12 individuals during Phase 1
and Phase 2 to account for two large (n = 12) groups or several smaller
groups. No Level A harassment take for killer whales is anticipated or
proposed to be authorized due to the small Level A harassment zones and
implementation of a 100 m shutdown which is larger than Level A
harassment isopleths.
Humpback Whales
Sightings of humpback whales in the project area are rare, and the
potential risk of exposure of a humpback whale to sounds exceeding the
Level B harassment threshold is low. Few, if any, humpback whales are
expected to approach the project area. However, there were two
sightings in 2017 of what was likely a single individual at the Ship
Creek Boat Launch (ABR 2017) which is located south of the project
area. Based on these data, the POA conservatively estimates one
humpback whale could be harassed every 16 days of pile driving.
Therefore, the POA requested 8 humpback whale takes during Phase 1 (127
days for Phase 1 * [1 humpback whale every 16 days]) and 5 takes (75
days for Phase 2 * [1 humpback whale every 16 days]) for Phase 2. This
could include sighting a
[[Page 72176]]
cow-calf pair on multiple days or multiple sightings of single humpback
whales. The POA did not request Level A take of humpback whales;
however, based on the distances to the large Level A harassment
thresholds relative to Level B harassment isoplehts and the fact
humback whale sightings in Upper Cook Inlet is rare, NMFS is proposing
to issue two Level A harassment takes per year to account for a single
individual or a cow/calf pair. Therefore, NMFS is proposing to issue
two Level A harassment takes and six Level B harassment takes during
Phase 1 and two Level A harassment takes and three Level B harassment
takes for Phase 2.
Beluga Whales
For beluga whales, we looked at several sources of information on
marine mammal occurrence in upper Cook Inlet to determine how best to
estimate the potential for exposure to pile driving noise from the PCT
Project. In their application, the POA took a two-step approach to
estimating Level B harassment take. The POA first estimated the numbers
of beluga whales potentially exposed to noise levels above the Level B
harassment threshold for pile installation and removal using the
following formula: Beluga Exposure Estimate = N * Area * number of days
of pile installation/removal, where: N = maximum predicted # of beluga
whales/km\2\ in Knik Arm (0.291 whales/km\2\) based on data from Goetz
et al. (2012a) and Area = Area ensonified above Level B harassment
threshold (km\2\). We note the actual beluga whale densities within the
Level B harassment isopleths predicted for the PCT project ranged from
0.042 to 0.236 beluga whales/km\2\. However, the POA applied the
highest beluga whale density in upper Knik Arm. The higher densities
north of the POA are expected as beluga whales tend to concentrate in
Eagle Bay to forage whereas in the lower Arm, where the POA is located,
habitat use is more commonly associated with traveling. The POA's
simple calculation results in 103 takes in Phase 1 and 125 takes in
Phase 2. The second step in POA's take estimate approach was to apply a
50 percent correction factor to their density-based calculation. The
POA provided several reasons why this reduction factor was appropriate,
including, but not limited to: The POA's commitment to using a bubble
curtain means that noise levels along the western side of Knik Arm will
remain below the regulatory thresholds; providing a travel corridor for
beluga whales to access upper Knik Arm; for the majority of PCT
construction and pile installation and removal, only approximately half
of the width of Knik Arm, along the eastern shore, would be ensonified;
beluga whales observed in Knik Arm during the autumn were most
frequently sighted on the western side of the arm (Funk et al. 2005);
and beluga whales in Knik Arm year-round; however, sightings are much
lower in winter through early summer.
We reviewed the POA's density-based take calculation approach and
their reasons for applying a 50 percent correction factor. We
determined use of the Goetz density data for this specific project is
problematic because the density data is based on June aerial surveys
while the PCT project is occurring from April through November, the
data is over seven years old, and the multiple years of monitoring data
collected by the POA is not incorporated into this approach. Regarding
the rationale for applying a 50 percent correction factor, we found the
use of a bubble curtain and the fact the majority of pile driving would
ensonify half or less than half of the width of Knik Arm is already
captured by the ensonsified area which is embedded into the take
calculation. The POA is not pile driving during winter when beluga
whale abundance is lowest and although early summer tends to see lower
beluga abundance, the density used in the take calculation is from June
surveys. Finally, any habituation to repeated exposure may be
considered qualitatively in analyzing the intensity of reactions to
pile driving but it cannot be quantified and is not considered in take
estimates.
To better capture beluga whale distribution and abundance, we
undertook a multi-step analysis consisting of an evaluation of long-
term, seasonal sighting data, proposed mitigation and monitoring
measures, the amount of documented take from previous POA projects
compared to authorized take, and considered group size. First, in lieu
of density data, NMFS applied sighting rate data presented in Kendell
and Cornick (2015) to estimate hourly sighting rates per month (April
through November). We then identified hours of pile driving per month.
The POA indicated there will be extended durations when no pile driving
is happening (e.g., later in the season when decking and other out-of-
water work is occurring); however, the schedule could not be more
refined than assuming an equal work distribution across the
construction season. The POA did indicate the first two weeks of April
and the last two weeks in November would be most likely utilized for
equipment mobilization and demobilization; therefore, pile driving
effort during those months were limited to two weeks. The data and
calculated exposure estimates are presented below. These calculations
assume no mitigation (i.e., uncorrected take estimates) and that all
animals observed would enter a given Level B harassment zone during
pile driving. In total, we would expect approximately 94 exposures in
Phase 1 and 60 exposures in Phase 2.
Table 9--Uncorrected Beluga Whale Exposure Estimates for Phase 1 and Phase 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
Monitoring data \1\ Estimated instances of take
---------------------------------------------------------------------------------------------------------------
Month Number of Pile driving CIBW Pile driving CIBW
Effort hours whales Average whale/ hours Phase 1 exposures hours Phase 2 exposures
observed hr \2\ Phase 1 \2\ Phase 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
April................................... 12 2 0.17 25.64 4.27 16.37 2.73
May..................................... 156 40 0.26 51.29 13.15 32.71 8.39
June.................................... 280 8 0.03 51.29 1.47 32.71 0.94
July.................................... 360 2 0.01 51.29 0.28 32.71 0.18
August.................................. 426 269 0.63 51.29 32.38 32.71 20.65
Sept.................................... 447 169 0.38 51.29 19.37 32.71 12.35
October................................. 433 22 0.05 51.29 2.61 32.71 1.66
Nov..................................... 215 175 0.82 25.64 20.91 16.37 13.35
---------------------------------------------------------------------------------------------------------------
Total............................... 2317 685 0.30 359.02 94.44 229.00 60.25
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ From Kendell and Cornick 2015.
\2\ Assumes equal work distribution/month except in April and November when the POA has indicated they would be conducting only 2 weeks of pile driving
due to time needed for mobilization and demobilization.
[[Page 72177]]
Second, NMFS then considered the proposed mitigation and
distribution of beluga whales in Knik Arm. In the POA's application,
they proposed a 100-m shutdown zone. However, as described in more
detail below, NMFS has imposed additional mitigation designed to reduce
Level B harassment take as well as Level A harassment take. We
recognize that in certain situations, pile driving may not be able to
be shutdown prior to whales entering the Level B harassment zone due to
safety concerns. Sometimes beluga whales were initially observed when
they surfaced within the harassment zone. For example, on November 4,
2009, 15 whales were initially sighted approximately 950 meters north
of the project site near the shore, and then they surfaced in the Level
B harassment zone during vibratory pile driving (ICRC 2009b).
Construction activities were immediately shut down, but the 15 whales
were documented as takes. On other occasions, beluga whales were
initially sighted outside of the harassment zone and shut down was
called, but the beluga whales swam into the harassment zone before
activities could be halted, and take occurred. For example, on
September 14, 2009, a construction observer sighted a white beluga
whale just outside the harassment zone, moving quickly towards the
1,300 meter Level B harassment zone during vibratory pile driving. The
animal entered the harassment zone before construction activity could
be shut down, and was documented as a take (ICRC 2009c).
To more accurately estimate potential exposures, we looked at
previous takes at the POA and those actually authorized. Between 2008
and 2012, NMFS authorized 34 beluga whale takes per year to POA with
mitigation measures similar to the measures proposed here. The percent
of the authorized takes that were documented as actually occurring
during this time period ranged from 12 to 59 percent with an average of
36 percent (Table 10). The previous method of estimating take was based
on density; however, the results between using densities versus
sighting rate are somewhat comparable (e.g., 94 exposures in Phase 1
using sighting rates versus 103 exposures using density). Further,
there was extensive scientific monitoring and POA construction
monitoring occurring during these time periods; therefore, we believe
there is little potential animals were taken but not observed.
Therefore we believe this first step in our analysis is reasonable.
Table 10--Authorized and Reported Beluga Whale Takes During POA Activities From 2009-2012
----------------------------------------------------------------------------------------------------------------
Percent of
ITA effective dates Reported takes Authorized authorized
take takes occurred
----------------------------------------------------------------------------------------------------------------
15 July 2008-14 July 2009....................................... 12 34 35
15 July 2009-14 July 2010....................................... 20 34 59
15 July 2010-14 July 2011....................................... 13 34 38
15 July 2011-14 July 2012....................................... 4 34 12
----------------------------------------------------------------------------------------------------------------
Second, we applied the highest percentage of previous takes to
ensure potential impacts to beluga whales are fully evaluated and to
ensure the POA has an adequate amount of take. Therefore, we assume
that approximately 59 percent of the takes calculated for Phase 1
(n=94) and Phase 2 (n=64) will actually be realized. This approach is
further supported by the proposed mitigation measures which are strict
shutdown requirements for CIBWs with a goal of avoiding Level B take
altogether, similar to previous POA mitigation measures.
Finally, we then considered group size from the long-term
scientific monitoring effort and POA opportunistic data to determine if
these numbers represented realistic scenarios. Figure 2 presents data
from the scientific monitoring program. The APU scientific monitoring
data set documented 390 beluga whale sightings.
[GRAPHIC] [TIFF OMITTED] TN30DE19.011
[[Page 72178]]
Group size exhibits a mode of 1 and a median of 2, indicating that
over half of the beluga groups observed over the 5-year span of the
monitoring program were of individual beluga whales or groups of 2. The
95th percentile of group size from the APU scientific monitoring data
set is 11.1 beluga whales. This means that, of the 390 documented
beluga whale groups in this data set, 95 percent consisted of fewer
than 11.1 whales; 5 percent of the groups consisted of more than 11.1
whales. We conclude the amount of take proposed to be authorized
following the approach above allows for the potential for large groups
to be exposed to noise above NMFS harassment thresholds.
For reasons described above, NMFS believes this approach adequately
analyzes the risk of beluga whale exposure to Level B harassment from
the PCT Project. We conclude there is the potential for 45 exposures in
Phase 1 and 33 exposures in Phase 2 (Table 11).
Table 11--Proposed Beluga Whale Level B Harassment Exposures
------------------------------------------------------------------------
Calculated
PCT construction phase exposure Proposed take \1\
------------------------------------------------------------------------
Phase 1--2020..................... 94 55
Phase 2--2021..................... 60 35
------------------------------------------------------------------------
\1\ Proposed take is identified as 59 percent of the calculated
exposures using sighting rates.
In summary, the total amount of Level A harassment and Level B
harassment proposed to be authorized for each marine mammal stock is
presented in Table 12.
Table 12--Proposed Amount of Take, by Stock and Harassment Type
--------------------------------------------------------------------------------------------------------------------------------------------------------
Phase 1 (2020) Phase 2 (2021)
-----------------------------------------------------------------------------------------------
Species Stock Percent of Percent of
Level A Level B stock Level A Level B stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale.................... Western N Pacific... 2 6 0.7 2 4 0.7
Beluga whale...................... Cook Inlet.......... 0 55 17 0 35 11
Killer whale...................... Transient/Alaska 0 12 2 0 12 2
Resident.
Harbor porpoise................... Gulf of Alaska...... 21 43 0.2 13 25 0.2
Steller sea lion.................. Western............. 0 13 <0.1 2 6 <0.1
Harbor seal....................... Cook Inlet/Shelikof. 305 711 3.6 180 420 2.1
--------------------------------------------------------------------------------------------------------------------------------------------------------
Proposed Mitigation
In order to issue an IHA under Section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to such
activity, and other means of effecting the least practicable impact on
such species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of such species or stock for taking for certain
subsistence uses. 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 POA presented a number of mitigation measures in section 11 of
their application. NMFS accepted a number of these measures (e.g., use
of bubble curtains on all plumb piles) but also requested the POA
consider additional noise attenuation measures and modified shut down
zones, among other things. We present mitigation measures NMFS has
determined to affect the least practicable adverse impact on marine
mammals and their habitat followed by a discussion of the ongoing
considerations by NMFS and the POA which will be made final prior to
issuance of the final IHA.
A key mitigation measure NMFS considered for this project is
reducing noise levels propagating into the environment. The POA will
use a bubble curtain on all plumb piles. At this time, NMFS is not
requiring an unconfined bubble curtain. The POA presented a Technical
Manual on the analysis of water current velocity data collected in the
vicinity of the proposed PCT (TerraSound 2016) demonstrating current
speeds were approximately 3 knots (kts) during times when tides were
strongest. The POA has not finalized the bubble curtain design;
however, bubble ring placement and bubble sizes and spacing must combat
the current. In addition, the sound source verification results (see
Proposed
[[Page 72179]]
Monitoring and Reporting Measures section below) must demonstrate the
bubble curtain is achieving consistent noise attenuation such that
source levels are at or below those evaluated in this document during
all tide phases. The bubble curtain will be designed to absorb as much
sound as possible. The POA proposed, and NMFS is requiring, all plumb
piles installed in-water be done so in the presence of a fully
operational bubble curtain.
The POA is also currently evaluating means by which to reduce sound
propagation on battered piles. The POA has indicated that a full bubble
curtain ring is not possible on battered piles; however, NMFS has
requested the POA further investigate other means of reducing noise
such as a linear or semi-circular curtain around the work area. The POA
is actively looking into this and final noise attenuation plans will be
made prior to issuance of the IHA. We note that for purposes of our
analysis here, NMFS did not consider any noise attenuation during
installation of battered piles. However, we are requiring that
unattenuated piles not be driven in water depths greater than 3 meters
based on the cutoff frequency (Roger and Cox, 1988). The intent of this
measure is to reduce sound propagation. In shallower waters, lower
frequencies tend to be cutoff more rapidly than high frequency sources.
In addition to noise attenuation devices, NMFS considered the
amount of sound energy entering the aquatic environment. The
installation of 144-in piles is included in Phase 2 (2021) and NMFS has
determined that given the extensive Level B harassment zone generated
from this activity, vibratory driving these large piles during peak
beluga whale season poses an amount of risk and uncertainty to the
degree that it should be minimized. Therefore, vibratory driving 144-in
piles will not occur during August. Further, to minimize the potential
for overlapping sound fields from multiple stressors, the POA will not
simultaneously operate two vibratory hammers for either pile
installation or removal. This measure is designed to reduce
simultaneous in-water noise exposure. Because impact hammers will
unlikely be dropping at the same time, and to expedite construction of
the project to minimize pile driving during peak beluga whale abundance
periods, NMFS is not proposing to restrict the operation of two impact
hammers at the same time. We note that harassment zones during impact
pile driving will radiate from both of the piles being driven, not a
single pile.
NMFS also considered other means by which to remove piles since the
majority of piles installed for this project are temporary (we note the
POA reduced the amount of temporary piles originally proposed for this
project). NMFS inquired about the potential to direct pull piles or cut
them off at the mudline; thereby, reducing in-water noise levels. The
POA responded that the depth at which temporary piles would be
installed and substrate precludes directly pulling the piles. Cutting
piles at the mudline also presents navigational (e.g., anchoring) and
safety concerns.
In their IHA application, the POA proposed a 100-m shutdown zone
for all marine mammals or, where the Level A harassment zone was deemed
to be greater than 100 m, a shutdown zone equivalent to the Level A
harassment zone. NMFS found this measure did not effect the least
practicable adverse impact on marine mammals for several reasons.
First, except for 48-in piles, the Level A harassment zones in the
application are based on estimated spectra which NMFS does not support.
Therefore, NMFS calculated Level A harassment zones for all piles
(except 48-in piles) using the single frequency, default weighting
factor adjustment provided in the NMFS User Spreadsheet. As shown in
Table 8, Level A harassment zones for low-frequency and high frequency
cetaceans and pinnipeds are rather large when considering multiple
piles installed per day and installation of the 144-in piles. Sighting
rates at these distances, specifically for harbor seals and porpoise,
are unlikely to be good enough to ensure effective coverage. For these
reasons, NMFS proposes a 100-m shutdown zone for all marine mammals
(except beluga whales).
For beluga whales, NMFS determined the proposed shutdown zone of
100 m or the Level A harassment zone (if greater than 100 m) was not
consistent with the conservation intentions of the POA nor what NMFS
would consider as effecting the least practicable adverse impact based
on the proposed project description and acoustic analysis. NMFS and the
POA entered into discussions to discuss these opinions and have
determined that measures and shutdown zones used in previous IHAs would
ensure valuable protection and conservation of beluga whales. For this
reason, NMFS is proposing the POA implement the following measures for
CIBWs:
Prior to the onset of pile driving, should a beluga
whale(s) be observed within Knik Arm or approaching the mouth of Knik
Arm, pile driving will be delayed until the whale moves away from the
POA or is not re-sighted within 30 minutes. If non-beluga whale species
are observed within or likely to enter the Level B harassment zone
prior to pile driving, the POA may commence pile driving, recording and
reporting MMPA take that occurs as a result.
If pile driving has commenced and a beluga whale is
observed within or likely to enter the Level B harassment zone, pile
driving will shut down and not re-commence until the whale is out of
and on a path away from the Level B harassment zone or until no beluga
whale has been observed in the level B harassment zone for 30 minutes.
If, during pile driving, PSOs can no longer effectively
monitor all waters within the Level B harassment zone for the presence
of marine mammals due to environmental conditions (e.g., fog, rain,
wind), pile driving may continue only until the current segment of pile
is driven; no additional sections of pile or additional piles may be
driven until conditions improve such that the Level B harassment zone
can be effectively monitored. If the Level B harassment zone cannot be
monitored for more than 15 minutes, the entire Level B zone must be
cleared again for 30 minutes prior to pile driving.
In addition to these measures which greatly reduce the potential
for harassment to beluga whales and set shutdown zones that
realistically reflect non-beluga whale detectability, NMFS is including
general mitigation measures typically included in IHAs:
PSOs shall begin observing for marine mammals 30 minutes
before pile driving begins for the day and must continue for 30 minutes
when pile driving ceases at any time. If pile driving has ceased for
more than 30 minutes within a day, another 30-minute pre-pile driving
observation period is required before pile driving may commence.
POA must use soft start techniques when impact pile
driving. Soft start requires contractors to provide an initial set of
three strikes at reduced energy, followed by a thirty-second waiting
period, then two subsequent reduced energy strike sets. A soft start
must be implemented at the start of each day's impact pile driving and
at any time following cessation of impact pile driving for a period of
thirty minutes or longer.
For in-water construction other than pile driving, the POA
must cease operations or reduce vessel speed to the minimum level
required to maintain steerage and safe working conditions if a marine
mammal approaches within 10 m of the equipment or vessel.
[[Page 72180]]
POA is required to conduct briefings for construction
supervisors and crews, the monitoring team, and POA staff prior to the
start of all pile driving activity, and when new personnel join the
work, in order to explain responsibilities, communication procedures,
the marine mammal monitoring protocol, and operational procedures.
If a species for which authorization has not been granted,
or a species for which authorization has been granted but the
authorized takes are met, is observed approaching or within the
monitoring zone (Table 8), 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 the 30 minutes observation time period has elapsed.
Based on our evaluation of the applicant's proposed measures, as
well as other measures considered by NMFS, NMFS has preliminarily
determined that the proposed mitigation measures provide the means
effecting the least practicable impact on the affected species or
stocks and their habitat, paying particular attention to rookeries,
mating grounds, and areas of similar significance and on the
availability of such species or stock for subsistence uses.
Proposed Monitoring and Reporting
In order to issue an IHA for an activity, Section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104 (a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present in the
proposed action area. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density).
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas).
Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors.
How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks.
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat).
Mitigation and monitoring effectiveness.
During the 2016 TPP, observers for that project ()provided a number
of recommendations to improve marine mammal monitoring for POA
projects. These recommendations included:
A minimum of three PSOs at an observation station is
necessary to prevent fatigue and increase accuracy of detecting marine
mammals, especially for large[hyphen]radius zones. When using three
PSOs, one PSO is observing, one PSO is recording data (and observing
when there are no data to record), and the third PSO is resting. A
fourth PSO allows the scanning of a 90[hyphen]degree arc, instead of a
180[hyphen]degree arc, increasing scan intensity and the likelihood of
detecting marine mammals. Thirty to 60 minute rotations work well with
this schedule.
Communications between the pile driving/construction
contractor and the PSOs should take place between one dedicated point
of contact, or Lead PSO, for each shift.
Each observation station should employ a pair of
25[hyphen]power binoculars as they were superior to the 7- and 10-
power binoculars at detecting and identifying marine mammals at greater
distances.
Electronic data collection methods should be considered.
iPad applications and other technological advances make it possible to
collect data quickly and accurately. A theodolite can be plugged into
the device and marine mammal locations can be calculated on the spot,
minimizing uncertainty. Data can be downloaded throughout the day to a
database, eliminating the need for data entry by hand, and allowing
quicker data assessment.
Hard copy maps with pre[hyphen]established
grid[hyphen]cells and harassment zones specific to the pile location
being driven were invaluable. These maps allowed for immediate,
accurate and consistent identification of marine mammal locations
relative to the harassment zones, regardless of observation station.
The POA's IHA application addresses the majority of these
recommendations in its Marine Mammal Monitoring Plan (Appendix A in
POA's application) and NMFS proposes additional measures here. NMFS is
requiring at least three PSOs (two on-watch and one to record data)
will be positioned at the norther and southern station while two PSOs
will be on-watch at the PCT (i.e., pile driving) station. Each station
will be equipped with several pieces of equipment (see section 2.4 in
Appendix A of POA's application), including 25x binoculars and a range
finders, as recommended above. One station will have a theodolite. PSOs
may observe for no more than 4 hours at time and no more than 12 hours
per day. The POA will submit all PSO CVs to NMFS prior to a PSO working
on this project. Where necessary, NMFS may require a potential PSO
shadow an experienced PSO before working independently.
To improve beluga whale detection, NMFS has worked with the POA to
include PSO stations in different locations than the three stations
proposed by the POA, which were all on POA property. The POA will have
three PSO stations. One PSO station will be located at the PCT pile
driving site. One station will be at Port Wornzof or a similar location
to maximize beluga whale detection outside of Knik Arm and the mouth of
Knik Arm. PSOs at this location will have unencumbered views of the
entrance to Knik Arm and can provide information on beluga whale group
dynamics (e.g., group size, demographics, etc) and behavior of animals
approaching Knik Arm in the absence of and during pile driving. We have
also considered moving a station from the POA property to Port
MacKenzie for an improved view of beluga whales moving from north to
south within Knik Arm. However, the POA is currently investigating if
this is an option with respect to accessibility (i.e. private property)
and personnel safety. If Port MacKenzie is not an available option, the
third PSO station will be located toward the north end of the POA
property. The exact placement of this northern station will be
determined prior to issuing the IHA. We note the previous station at
Cairn Point
[[Page 72181]]
used several years ago is Elemendorf Air Force Base property and is no
longer accessible.
For both Phase 1 and Phase 2, NMFS is requiring the POA submit
interim weekly and monthly monitoring reports during the PCT
construction season. These reports must include a summary of marine
mammal species and behavioral observations, pile driving shutdowns or
delays, and pile work completed. A final end-of season report will be
submitted to NMFS within 90 days following pile driving. The report
must include: Dates and times (begin and end) of all marine mammal
monitoring; a description of daily construction activities, weather
parameters and water conditions during each monitoring period; number
of marine mammals observed, by species, distances and bearings of each
marine mammal observed to the pile being driven or removed, age and sex
class, if possible; number of individuals of each species
(differentiated by month as appropriate) detected within the monitoring
zone, and estimates of number of marine mammals taken, by species (a
correction factor may be applied); description of mitigation triggered,
and description of attempts to distinguish between the number of
individual animals taken and the number of incidences of take. In
addition, any acoustic data and analysis collected throughout the year
will also be made available to NMFS in the form of an interim report
within 10 days of data collection and a final report within 60 days.
Mean, median, and peak sound source levels (dB re: 1[micro]Pa):
cumulative sound exposure level (SELcum), peak sound pressure level
(SPLpeak), root mean square sound pressure level (SPLrms), and single-
strike sound exposure level (SELs-s) will be reported as well as pile
descriptions and acoustic monitoring methods (e.g., sampling rate,
distance to the hydrophone from the pile, etc.).
NMFS has also included reporting requirements for more uncommon
situations. In the unanticipated event that the specified activity
clearly causes the take of a marine mammal in a manner prohibited by
this IHA, such as serious injury, or mortality, POA must immediately
cease the specified activities and report the incident to the NMFS. In
the event POA discovers an injured or dead marine mammal, and the lead
observer determines that the cause of the injury or death is unknown
and the death is relatively recent (e.g., in less than a moderate state
of decomposition), POA must immediately report the incident to the
Office of Protected Resources, NMFS, and the Alaska Region Stranding
Coordinator, NMFS. In addition, in the event that POA discovers an
injured or dead marine mammal, and the lead observer determines that
the injury or death is not associated with or related to the specified
activities (e.g., previously wounded animal, carcass with moderate to
advanced decomposition, or scavenger damage), POA must report the
incident to the Office of Protected Resources, NMFS, and the Alaska
Region Stranding Coordinator, NMFS, within 24 hours of the discovery.
Negligible Impact Analysis and Determination
NMFS has defined negligible impact as an impact resulting from the
specified activity that cannot be reasonably expected to, and is not
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
``taken'' through harassment, NMFS considers other factors, such as the
likely nature of any responses (e.g., intensity, duration), the context
of any responses (e.g., critical reproductive time or location,
migration), as well as effects on habitat, and the likely effectiveness
of the mitigation. We also assess the number, intensity, and context of
estimated takes by evaluating this information relative to population
status. Consistent with the 1989 preamble for NMFS's implementing
regulations (54 FR 40338; September 29, 1989), the impacts from other
past and ongoing anthropogenic activities are incorporated into this
analysis via their impacts on the environmental baseline (e.g., as
reflected in the regulatory status of the species, population size and
growth rate where known, ongoing sources of human-caused mortality, or
ambient noise levels).
To avoid repetition, the majority of our analysis applies to all
species listed in Table 4 except for CIBWs, given that many of the
anticipated effects of this project on different marine mammal stocks
are expected to be relatively similar in nature. For CIBWs, there are
meaningful differences in anticipated individual responses to
activities, impact of expected take on CIBWs), or impacts on habitat;
therefore, we provide a supplemental analysis for CIBWs, independent of
the other species for which we propose to authorize take.
NMFS has identified key factors which may be employed to assess the
level of analysis necessary to conclude whether potential impacts
associated with a specified activity should be considered negligible.
These include (but are not limited to) the type and magnitude of
taking, the amount and importance of the available habitat for the
species or stock that is affected, the duration of the anticipated
effect to the species or stock, and the status of the species or stock.
The following factors support a negligible impact determination for the
affected stocks of humpback whales, killer whales, harbor porpoise,
harbor seals, and Steller sea lions. Some of these also apply to CIBWs;
however, a more detailed analysis for CIBWs is provided below.
No takes by mortality or serious injury are anticipated or
authorized;
The number of total takes (by Level A and Level B
harassment) are less than 3 percent of the best available abundance
estimates for all stocks;
Take would not occur in places and/or times where take
would be more likely to accrue to impacts on reproduction or survival,
such as within ESA-designated or proposed critical habitat,
biologically important areas (BIA), or other habitats critical to
recruitment or survival (e.g., rookery);
Take would occur over a short timeframe, being limited to
the short duration a marine mammal would likely be present within a
Level B harassment zone during pile driving;
Any impacts to marine mammal habitat from pile driving are
temporary and minimal; and
Take would only occur within upper Cook Inlet--a limited,
confined area of any given stock's home range.
For CIBWs, we further discuss our negligible impact finding in the
context of potential impacts to this endangered stock. As described in
the Recovery Plan for the Cook Inlet Beluga Whale (NMFS, 2016), NMFS
determined the following physical or biological features are essential
to the conservation of this species: (1) Intertidal and subtidal waters
of Cook Inlet with depths less than 30 feet mean lower low water (9.1
m) and within 5 mi (8 km) of high and medium flow anadromous fish
streams; (2) Primary prey species consisting of four species of Pacific
salmon (Chinook, sockeye, chum, and coho), Pacific eulachon, Pacific
cod, walleye pollock, saffron cod, and yellowfin sole, (3) Waters free
of toxins or other agents of a type and amount harmful to CI beluga
whales, (4) Unrestricted passage within or between the critical habitat
areas, and
[[Page 72182]]
(5) Waters with in-water noise below levels resulting in the
abandonment of critical habitat areas by CI beluga whales. The PCT
would not impact essential features 1-3 listed above. All construction
would be done in a manner implementing best management practices to
preserve water quality and no work would occur around creek mouths or
river systems leading to prey abundance reductions. In addition, no
physical structures would restrict passage; however, impacts to the
acoustic habitat are of concern. Previous marine mammal monitoring data
at the POA demonstrate beluga whales indeed pass by the POA during pile
driving. As described above, there was no significant difference in
beluga sighting rate with and in the absence of pile driving (Kendell
and Cornick, 2015). However, beluga whales do swim faster and in
tighter formation in the presence of pile driving (Kendell and Cornick,
2015).
During review of the POA's application, NMFS was concerned that
exposure to pile driving at the PCT could result in beluga whales
avoiding Knik Arm and thereby not accessing the productive foraging
grounds north of POA such as Eagle River flats based on the proposed
project and mitigation measures--thus, impacting essential feature
number 5 above. Although the data previously presented demonstrate
whales are not abandoning the area (i.e., no significant difference in
sighting rate with and without pile driving), we considered the results
of a recent expert elicitation (EE) at a 2016 workshop, which predicted
the impacts of noise on CIBW survival and reproduction given lost
foraging opportunities, to inform our assessment of impacts on this
stock. The 2016 EE workshop used conceptual models of an interim
population consequences of disturbance (PCoD) for marine mammals (NRC
2005; New et al. 2014, Tollit et al., 2016) to help in understanding
how noise-related stressors might affect vital rates (survival, birth
rate and growth) for CIBW (King et al. 2015). NMFS (2015, section
IX.D--CI Beluga Hearing, Vocalization, and Noise Supplement) suggests
that the main direct effects of noise on CIBW are likely to be through
masking of vocalizations used for communication and prey location, and
habitat degradation. The 2016 workshop on beluga whales was
specifically designed to provide regulators with a tool to help
understand whether chronic and acute anthropogenic noise from various
sources and projects are likely to be limiting recovery of the CIBW
population. The full report can be found at https://www.smruconsulting.com/publications/ and we provide a summary of the
expert elicitation portion of the workshop here.
For each of the noise effect mechanisms chosen for expert
elicitation, the experts to provide a set of parameter values that
determined the forms of a relationship between the number of days of
disturbance a female CIBW experiences in a particular period and the
effect of that disturbance on her energy reserves. Examples included
the number of days of disturbance during the period April, May and June
that would be predicted to reduce the energy reserves of a pregnant
CIBW to such a level that she is certain to terminate the pregnancy or
abandon the calf soon after birth, the number of days of disturbance in
the period April-September required to reduce the energy reserves of a
lactating CIBW to a level where she is certain to abandon her calf, and
the number of days of disturbance where a female fails to gain
sufficient energy by the end of summer to maintain themselves and their
calves during the subsequent winter. Overall, median values ranged from
16 to 69 days of disturbance depending on the question. However, for
this elicitation, a ``day of disturbance'' was defined as any day on
which an animal loses the ability to forage for at least one tidal
cycle (i.e., it forgoes 50-100% of its energy intake on that day).
Therefore, disturbance in this context is not equivalent to Level B
harassment. The mitigation measures NMFS has proposed for the PCT
project are designed to avoid the potential that any animal would lose
the ability to forage for one or more tidal cycles. While Level B
harassment (behavioral disturbance) is proposed to be authorized, our
mitigation measures would minimize the intensity of that harassment to
behavioral changes such as increased swim speeds, tighter group
formations, and cessation of vocalizations, not the loss of foraging
capabilities. Regardless, this elicitation recognized that pregnant or
lactating females and calves are inherently more at risk than other
animals, such as males. NMFS first considered proposing the POA
shutdown based on more vulnerable life stages (e.g., calf presence) but
ultimately determined all beluga whales warranted pile driving shutdown
to be protective of potential vulnerable life stages, such as
pregnancy, that could not be determined from observations, and to avoid
more severe behavioral reaction.
Monitoring data from the POA suggest pile driving does not
discourage beluga whales from entering Knik Arm and travelling to
critical foraging grounds such as those around Eagle Bay. As previously
described, sighting rates were not different in the presence or absence
of pile driving. This is not surprising as food is a strong motivation
for marine mammals. As described in Forney et al. (2017), animals
typically favor particular areas because of their importance for
survival (e.g. feeding or breeding), and leaving may have significant
costs to fitness (reduced foraging success, increased predation risk,
increased exposure to other anthropogenic threats). Consequently,
animals may be highly motivated to remain in an area despite negative
impacts (e.g., Rolland et al. 2012). Previous monitoring data indicates
beluga whales are responding to pile driving noise but not through
abandonment of critical habitat, including primary foraging areas north
of the port. Instead, they travel faster past the POA, more quietly,
and in tighter groups (which may be linked to the decreased
communication patterns). We anticipate these behaviors to continue;
however, do not believe they had adverse effects on reproduction or
survival as the whales continue to access critical foraging grounds
north of the POA and tight associations combat any communication space
lost within a group. Finally, as described previously, beluga whales
likely stay in upper Knik Arm for several days before exiting Knik Arm.
Acoustic data indicate beluga whales move through lower Knik Arm
relatively quickly, when entering or exiting the arm, and remain in the
upper arm for several days, or weeks, before moving back out into Cook
Inlet (Castellote et al., in press). Satellite telemetry data indicate
such a movement pattern may be common. Specifically, a beluga
instrumented with a satellite link time/depth recorder entered Knik Arm
on August 18th and remained in Eagle Bay until September 12th (Ferrero
et al. 2000). This longer-term use of upper Knik Arm would avoid
repetitive exposures from pile driving noise.
NMFS has included mitigation measures beyond those proposed by the
POA in the IHA application, specifically, not commencing pile driving
if beluga whales are observed within Knik Arm or within 1 km of the
mouth of Knik Arm, shutting down pile driving should a beluga whale
approach or enter the Level B harassment zone, stationing PSOs at Point
Woronzof, and not vibratory pile driving 144-in piles during August
(peak beluga season). These measures are designed to ensure beluga
whales will not abandon critical habitat and exposure to pile driving
[[Page 72183]]
noise will not result in adverse impacts on the reproduction or
survival of any individuals. The location of PSOs at Point Woronzof
allows for detection of beluga whales at much farther distances than
previous years and behavioral observations prior to whales entering
Knik Arm. Although NMFS does not anticipate beluga whales would abandon
entering Knik Arm in the presence of pile driving with the proposed
mitigation measures, these PSOs will be integral to identifying if
belugas are potentially altering pathways they would otherwise take in
the absence of pile driving. Because the POA is submitting weekly and
monthly reports, NMFS will be able to regularly evaluate the impacts of
the project on beluga whales. Finally, take by mortality, serious
injury, or Level A harassment of CIBWs is not anticipated or proposed
to be authorized.
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 CIBWs through
effects on annual rates of recruitment or survival:
No mortality or serious injury is anticipated or
authorized.
Area of exposure would be limited to travel corridors.
Data demonstrates Level B harassment manifests as increased swim speeds
past the POA and tight group formations and not through habitat
abandonment.
No critical foraging grounds (e.g. Eagle Bay, Eagle River,
Susitna Delta) would be impacted by pile driving.
While animals could be harassed more than once, exposures
are not likely to exceed more than a few per year for any given
individual and are not expected to occur on sequential days; thereby,
decreasing the likelihood of physiological impacts caused by chronic
stress or masking.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS preliminarily finds that the total marine
mammal take from the proposed activity will have a negligible impact on
all affected marine mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under Sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. Additionally, other qualitative
factors may be considered in the analysis, such as the temporal or
spatial scale of the activities.
For all stocks, the amount of taking is small relative to the
population size (0.2 to 17 percent). Further, the amount of take
proposed to be authorized likely represents smaller numbers of
individual harbor seals and Steller sea lions. Harbor seals tend to
concentrate near Ship Creek and have small home ranges; therefore, the
amount of take authorized likely represents repeat exposures to the
same animals. Previous Steller sea lion sightings identified that if a
Steller sea lion is within Knik Arm, it is likely lingering to forage
on salmon or eulachon runs and may be present for several days. With
respect to CIBW, they are known to enter Knik Arm and then exit after
several days of remaining within Knik Arm. There is potential an
individual is taken on both ingress and egress; however, due to the
mitigation measures (essentially takes are for animals where pile
driving cannot be shut down before exposure), the circumstances would
have to be such that pile driving is occurring while the whale is both
entering and exiting Knik Arm and that the animal is missed or taken
due to logistical constraints of shutting down pile driving immediately
in both cases. Therefore, the potential for repeat takes is low and we
anticipate take predominantly represents individual animals.
Regardless, the amount of take proposed to be authorized for CIBW is
small (17 percent or less).
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
sizes of the affected species or stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. No subsistence use
of CIBWs occurs and subsistence harvest of other marine mammals is
limited. The potential impacts from harassment on stocks that are
harvested would be limited to minor behavioral changes (e.g., increased
swim speeds, changes in dive time, temporary avoidance near the POA,
etc.) within the vicinity of the POA. Therefore, NMFS has determined
that the total taking of affected species or stocks would not have an
unmitigable adverse impact on the availability of such species or
stocks for taking for subsistence purposes.
Endangered Species Act (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 Region Protected
Resources Division Office, whenever we propose to authorize take for
endangered or threatened species.
NMFS is proposing to authorize take of CIBWs, humpback whales from
the Mexico DPS stock, and Steller sea lions from the western DPS, which
are listed under the ESA. Therefore, the Permit and Conservation
Division has requested initiation of Section 7 consultation with the
Alaska Region for the issuance of this IHA. NMFS will conclude the ESA
consultation prior to reaching a determination regarding the proposed
issuance of the authorization.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to the POA for the PCT Project, 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 POA's PCT
Project. 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
[[Page 72184]]
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:
A request for renewal is received no later than 60 days
prior to expiration of the current IHA.
The request for renewal must include the following:
(1) An explanation that the activities to be conducted beyond the
initial dates either are identical to the previously analyzed
activities or include changes so minor (e.g., reduction in pile size)
that the changes do not affect the previous analyses, take estimates,
or mitigation and monitoring requirements.
(2) A preliminary monitoring report showing the results of the
required monitoring to date and an explanation showing that the
monitoring results do not indicate impacts of a scale or nature not
previously analyzed or authorized.
Upon review of the request for renewal, the status of the
affected species or stocks, and any other pertinent information, NMFS
determines that there are no more than minor changes in the activities,
the mitigation and monitoring measures remain the same and appropriate,
and the original findings remain valid.
Dated: December 20, 2019.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2019-28102 Filed 12-27-19; 8:45 am]
BILLING CODE 3510-22-P