[Federal Register Volume 84, Number 170 (Tuesday, September 3, 2019)]
[Notices]
[Pages 45955-45983]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-18931]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XF505
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Construction Activities Associated
With the Raritan Bay Pipeline
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization; request
for comments on proposed authorization and possible renewal.
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SUMMARY: NMFS has received a request from Transcontinental Gas Pipe
Line Company, LLC (Transco), a subsidiary of Williams Partners L.P., to
take marine mammals incidental to construction activities associated
with the Raritan Bay Pipeline. Pursuant to the Marine Mammal Protection
Act (MMPA), NMFS is requesting comments on its proposal to issue an
incidental harassment authorization (IHA) to incidentally take marine
mammals during the specified activities. NMFS is also requesting
comments on a possible one-year renewal that could be issued under
certain circumstances and if all requirements are met, as described in
Request for Public Comments at the end of this notice. NMFS will
consider public comments prior to making any final decision on the
issuance of the requested MMPA authorizations and agency responses will
be summarized in the final notice of our decision.
DATES: Comments and information must be received no later than October
3, 2019.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service. Physical comments should be sent to
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments
should be sent to [email protected].
Instructions: NMFS is not responsible for comments sent by any
other method, to any other address or individual, or received after the
end of the comment period. Comments received electronically, including
all attachments, must not exceed a 25-megabyte file size. Attachments
to electronic comments will be accepted in Microsoft Word or Excel or
Adobe PDF file formats only. All comments received are a part of the
public record and will generally be posted online at
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: Jordan Carduner, 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: 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
[[Page 45956]]
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are issued or, if the taking is limited to harassment, a notice of a
proposed incidental take authorization may be provided to the public
for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of such species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of such takings are set forth.
The 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 evaluate our proposed action (i.e., the promulgation of
regulations and subsequent issuance of incidental take authorization)
and alternatives with respect to potential impacts on the human
environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 of the Companion Manual for NAO 216-6A,
which do not individually or cumulatively have the potential for
significant impacts on the quality of the human environment and for
which we have not identified any extraordinary circumstances that would
preclude this categorical exclusion. Accordingly, NMFS has
preliminarily determined that the proposed action qualifies to be
categorically excluded from further NEPA review.
Information in Transco's application and this notice collectively
provide the environmental information related to proposed issuance of
these regulations and subsequent incidental take authorization for
public review and comment. We will review all comments submitted in
response to this notice prior to concluding our NEPA process or making
a final decision on the request for incidental take authorization.
Summary of Request
On February 7, 2019, NMFS received a request from Transco for an
IHA to take marine mammals incidental to construction activities
associated with the Raritan Bay Loop pipeline offshore of New York and
New Jersey. Transco submitted a revised version of the application on
May 23, 2019, and this application was deemed adequate and complete.
Transco's request is for take of 10 species of marine mammals by
harassment. Neither Transco nor NMFS expects serious injury or
mortality to result from this activity and, therefore, an IHA is
appropriate.
Description of Proposed Activity
Overview
Transco, a subsidiary of Williams Partners L.P., is proposing to
expand its existing interstate natural gas pipeline system in
Pennsylvania and New Jersey and its existing offshore natural gas
pipeline system in New Jersey and New York waters. The Northeast Supply
Enhancement Project would consist of several components, including
offshore pipeline facilities in New Jersey and New York. The proposed
offshore pipeline facilities would include the Raritan Bay Loop
pipeline, which would be located primarily in Raritan Bay, as well as
parts of the Lower New York Bay and the Atlantic Ocean.
Construction of the Raritan Bay Loop pipeline would require pile
installation and removal, using both impact and vibratory pile driving,
which may result in the incidental take of marine mammals. Transco
would install and remove a total of 163 piles, which would range in
size from 10 to 60 inches in diameter, using a vibratory device and/or
diesel impact hammer. These piles would be temporary; they would remain
in the water only for the duration of each related offshore
construction activity. Once offshore construction of the project is
complete, all piles installed by Transco would be removed.
Dates and Duration
In-water construction is anticipated to occur between the 2nd
quarter of 2020 and the 4th quarter of 2020. Pile installation and
removal activities are planned to occur from June through August 2020.
However the timeframe for pile removal may occur in fall 2020. Pile
installation and removal activities are expected to take a total of
65.5 days.
Specific Geographic Region
Transco's proposed activity would occur in the waters of Raritan
Bay, the Lower New York Bay, and the Atlantic Ocean (see Figure 1 in
the IHA application). The Project area is located in the greater New
York Bight region. The New York Bight is a triangular-shaped area of
the continental shelf generally bounded by Montauk Point on eastern
Long Island, Cape May in southern New Jersey, and the open shallows of
the Atlantic Ocean. The depth of water in the area averages about 27
meters (m) (90 feet (ft)), except in the northwest-southeast-trending
Hudson Canyon, which has depths in excess of 73 m (240 ft) (Ketchem et
al. 1951). The New York Bight refers to the bend, or curve, in the
shoreline of the open coast and great expanse of shallow ocean between
Long Island and the New Jersey coast. Water depths exceed 30 m (100 ft)
approximately 80 kilometers (km) (50 statute miles) offshore.
Detailed Description of Specific Activity
Transco is proposing to expand its existing interstate natural gas
pipeline system in Pennsylvania and New Jersey and its existing
offshore natural gas pipeline system in New Jersey and New York waters
with the goal of providing an additional 400,000 dekatherms per day
capacity to its customers. To provide this additional capacity, Transco
proposes to expand portions of its system from an existing Compressor
Station in York County, Pennsylvania, to the Rockaway Transfer Point in
New York State waters, which represents the interconnection point
between Transco's existing Lower New York Bay Lateral and the existing
offshore Rockaway Delivery Lateral (RDL). The proposed project would
consist of several components, including onshore pipeline facilities in
Pennsylvania and New Jersey and offshore pipeline facilities in New
Jersey and New York. Only the offshore pipeline components of the
project have the potential to result in the take of marine mammals,
thus the onshore components of the project are not analyzed further in
this document.
Transco's proposed offshore pipeline facilities include the Raritan
Bay Loop pipeline, which would be located primarily in Raritan Bay as
well as parts of the Lower New York Bay and the Atlantic Ocean. The
Raritan Bay Loop would begin at the onshore connection
[[Page 45957]]
with the Madison Loop in Middlesex, New Jersey (see Figure 1 in the IHA
application). The offshore portion of the Raritan Bay Loop would extend
from the Sayreville shoreline approximately 37.6 km (23.3 mi) across
Raritan Bay and Lower New York Bay to the Rockaway Transfer Point,
which is the interconnection point with the RDL in New York State
waters in the Atlantic Ocean, approximately 4.8 km (3 mi) seaward of
Rockaway, New York. Approximately 9.6 km (6.0 mi) of the offshore
portion of the Raritan Bay Loop route would cross New Jersey waters,
while the remaining 28 km (17.4 mi) would cross New York waters. The
Raritan Bay Loop would cross a continuous expanse of open marine and
estuarine waters in New Jersey and New York, which consists of three
major contiguous waterbodies, including Raritan Bay, Lower New York
Bay, and the Atlantic Ocean (See Figures 1 and 2 in the IHA
application). This area is part of the coastal region known as the New
York Bight.
Construction of the Raritan Bay Loop pipeline would require the
installation of 163 piles, ranging in size from 10 to 60 inches in
diameter, using a vibratory device and/or diesel impact hammer. Impact
pile drivers are piston-type drivers that use various means to lift a
piston to a desired height and drop the piston against the head of the
pile in order to drive it into the substrate (Caltrans, 2015). Diesel
impact hammers would be used to install approximately 34 steel piles
(Table 1). A vibratory device uses spinning counterweights, causing the
pile to vibrate at a high speed. The vibrating pile causes the soil
underneath it to ``liquefy'' and allow the pile to move easily into or
out of the sediment. Vibratory devices generally have source levels 10
to 20 decibels (dB) lower than impact devices, so their use is
considered a means to reduce overall underwater sound when pile driving
is necessary for a project and suitable sediment conditions exist
(Caltrans, 2015). Vibratory devices would be used to install and remove
approximately 163 steel pipe piles (Table 1). Note that some piles
would require both impact and vibratory installation.
The total time to install a pile is dependent on the installation
method (vibratory or impact), diameter of the pile, substrate
composition, and depth the pile needs to penetrate through the
substrate. For pile installation of 0.9- to 1.5-m (34- to 60-in) piles
using a diesel impact hammer, the estimated time is 38 to 62 minutes
per pile. For pile installation of 0.3- to 1.5-m (10- to 60-in) piles
using a vibratory hammer, the estimated time is 15 minutes per pile.
For pile removal of 0.3- to 1.5-m (10- to 60-in) piles using a
vibratory hammer, the estimated time is 5 to 30 minutes per pile. The
minimum handling time (i.e., periods during which the pile is being
positioned, steadied, etc., and no in-water construction noise is
anticipated) is dependent on activity type and pile size. For vibratory
hammer periods for 0.3- to 1.2-m (10- to 48-in) piles, the handling
time ranges from 15 to 45 minutes. For vibratory hammer periods for
1.5-m (60-in) piles, the minimum handling time is 1 hour and 45
minutes. For impact hammer periods, the minimum handling time is 30
minutes. The total duration of pile installation (including both
vibratory and impact pile driving) is estimated at 42.5 days. The piles
would remain in the offshore environment only for the duration of each
related offshore construction activity. Once offshore construction is
complete, all piles would be removed using a vibratory hammer, which is
expected to occur over an estimated 23 days. Thus the total duration of
pile installation and removal is 65.5 days (i.e., 42.5 days for pile
installation and 23 days for pile removal). Installation and removal of
all piles is expected to be completed during summer 2020 (June-August);
however, pile removal could shift to fall 2020 (September, October,
and/or November), after finalization of the construction schedule.
All piles would be installed along a string of locations within
Raritan Bay (see Figure 2 in the IHA application). Transco would
complete construction of the various components of the offshore
pipeline in several stages with overlapping schedules. An overview of
these stages and their general sequence are described below.
Temporary fixed platform: During assembly of the fixed
platform, vibratory and impact hammers would be used to install the
steel piles; vibratory hammers would be used to remove the piles once
the work is completed.
Pre-trenching, cable crossings, and initial pipelay:
Trenching for the offshore (subsea) pipeline would take place using a
clamshell dredging device. One clamshell dredge with an environmental
bucket and its supporting scows would be mobilized to first excavate a
pit and trench at the offshore horizontal directional drill exit point
for the Morgan Shore Approach horizontal directional drill (HDD).
Transco would also mobilize a barge equipped with diving, jetting, and
material-handling equipment to remove sediment that covers the first
Neptune Cable crossing. Transco would then place concrete mattresses on
either side of the cable in the excavated areas to create a bridge
above the cable. Due to shallow water depths near the Morgan shoreline,
a combination of the pipelay barge and the temporary fixed platform
would install pipeline in this section of trench. Following completion
of a successful hydrostatic test of the pipeline, a clamshell dredge
would backfill the trench. A second clamshell dredge with an
environmental bucket would begin trenching the Raritan Bay Channel and
the Chapel Hill Channel crossing.
HDD Crossings: For the Morgan Shore Approach HDD, Transco
would mobilize a marine-support barge. The clamshell dredge (with
environmental bucket) would excavate the exit point and then a
vibratory device would be used to install the temporary fixed platform
and the piles, known as ``goal posts,'' to guide the pipe at the exit
point. Transco would assemble the HDD pipe string on the pipelay barge,
a winch wire from the fixed platform would be attached to the HDD pipe
string that would pull the pipe string into place with the aid of a tug
on the tail end section, lay the pipe string on the seafloor, and then
complete a hydrostatic test of the pipeline segment. For the Ambrose
Channel crossing, Transco would mobilize a clamshell dredge with an
environmental bucket and two liftboats with drilling equipment to the
Lower New York Bay. The clamshell dredge would excavate pits at the
east point and west point, and then a vibratory device would be used to
install piles (goal posts) on opposite sides of the Ambrose Channel.
Following the goal post installation, dolphin/fender piles (installed
using a vibratory device and/or impact hammer), and a casing would be
installed at both HDD pits. The HDD string would then be laid and
pulled through.
Additional Pipelay and Backfill: Following assembly and
installation of the Ambrose Channel HDD described above, an anchored
pipelay barge would begin laying pipe on the seafloor from the east
Ambrose HDD pit to the Rockaway Neptune cable crossing. The anchored
pipelay barge would then relocate to west of the Ambrose Channel entry
HDD point and lay the pipeline from the west Ambrose HDD pit to the
mid-line tie-in point at milepost (MP) 16.6. After Transco has laid the
pipeline, Transco would use a jet trencher to lower the pipeline and a
clamshell dredge would backfill the trench near the Ambrose Channel,
Ambrose HDD pits, and navigation channels. Transco would bury the pipe
to a minimum depth of 1.22 m (4 ft) (or
[[Page 45958]]
equivalent) and in accordance with any permit conditions as directed by
the USACE.
Subsea Manifold Tie-in, Hydrostatic Testing, and
Commissioning: Hand jets would be used to expose the existing subsea
manifold at the RDL, and a new tie-in valve spool would be installed. A
tie-in skid and tie-in spools would be installed at the end of the
Raritan Bay Loop. Transco would seal the Raritan Bay Loop pipeline
between the onshore entry point and the tie-in skid and pre-
commissioning would then occur, which would include hydrostatic
pressure testing of the new pipeline. After completion of the
hydrostatic test, a final spool piece would be installed to connect the
Raritan Bay Loop to the subsea manifold. The tie-in spools between the
tie-in skid and tie-in valve spool would be dewatered, the manifold
tie-in location would be backfilled, and Transco would introduce
natural gas into the completed Raritan Bay Loop.
The various components of the proposed construction of the Raritan
Bay Loop pipeline, including pile type, size and quantity, installation
method (i.e., impact or vibratory), and pile driving or removal
duration, are shown in Table 1 and are described in greater detail in
the IHA application.
Table 1--Pile Driving Summary for Raritan Bay Loop, Including Pile Types and Driving Durations
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Installation Removal
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Diameter Installation Removal
Milepost Site Pile type Purpose (in.) Quantity method Driving time Duration time Duration
per pile \c\ (days) (min./ (days)
\d\ pile) \d\
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12.59....... Morgan Shore Platform Piles Temporary fixed 36 18 Vibratory & V-15 Min/Pile.. 4.5 30 3
Approach HDD. (for temporary platform for Diesel Impact I-52-62 Min/
fixed Morgan Shore Hammer. Pile \e\.
platform). Approach HDD.
12.59....... Morgan Shore Platform Provide 36 4 Vibratory & V-15 Min/Pile.. 2 30
Approach HDD. Reaction Piles. additional Diesel Impact I-52-62 Min/
lateral Hammer. Pile \e\.
capacity for
pipeline
pulling winch.
12.59....... Morgan Shore Support Barge Tie up and 36-48 4 Vibratory V-15 Min/Pile.. 2 15
Approach HDD. Fender Piles. breast support Hammer.
barge
alongside HDD
operations.
12.59....... Morgan Shore Water Barge Tie up and 36-48 4 Vibratory V-15 Min/Pile.. 15
Approach HDD. Fender Piles. breast water Hammer.
barge
alongside HDD
operations.
12.59....... Morgan Shore HDD String Goal Support HDD 24 10 Vibratory V-15 Min/Pile.. 3 5 3
Approach HDD. Posts. string. Hammer.
13.84....... Neptune Power Sleeper Provide 10 8 Vibratory V-15 Min/Pile.. 2 15 1.5
Cable Crossing Vertical Pile. mechanical Hammer.
(MP13.84). protection to
ensure
separation
between
Neptune Power
cable and
pipeline.
14.5 to 16.5 MP14.5 to Morgan Shore Ensure pipeline 24 22 Vibratory V-15 Min/Pile.. 5 15 1.5
MP16.5. Pull Vertical stays within Hammer.
Guide Piles. pipeline
corridor
during surface
tow between
MP14.5 to
MP16.5.
28.0 to MP28.0 to Pipelay Barge Assist pipelay 34 12 Vibratory V-15 Min/Pile.. 3 30 2
29.36. MP29.36. Mooring Pile. barge with Hammer.
mooring in
vicinity of
Ambrose
Shipping
Channel.
29.4........ Ambrose Channel W750 Side Piles Landing of 36 3 Vibratory V-15 Min/Pile.. 1.5 15 0.5
HDD West Side. small barges/ Hammer.
vessels
alongside
prior to
fender piles
being
installed.
29.4........ Ambrose Channel Reaction Frame Provide 36-60 8 Vibratory & V-15 Min/Pile.. 4 30 0.5
HDD West Side. Piles. additional Diesel Impact I-38 Min/Pile e
lateral Hammer. f.
capacity for
HDD pipeline
pull.
29.4........ Ambrose Channel Support Barge Tie up and 36-48 4 Vibratory V-15 Min/Pile.. 1.5 15 1
HDD West Side. Fender Piles. breast support Hammer.
barge
alongside HDD
operations.
29.4........ Ambrose Channel Water Barge Tie up and 36-48 4 Vibratory V-15 Min/Pile.. 15
HDD West Side. Fender Piles. breast water Hammer.
barge
alongside HDD
operations.
29.4........ Ambrose Channel HDD String Goal Support HDD 24 12 Vibratory V-15 Min/Pile.. 1.5 5 2
HDD West Side. Posts. string. Hammer.
30.48....... Ambrose Channel Ambrose East Ensure HDD 24 22 Vibratory V-15 Min/Pile.. 5 15 0.5
HDD East Side. Vertical string is Hammer.
Stabilization secured while
Piles. awaiting
pullback.
30.48....... Ambrose Channel W751 Side Piles Landing of 36 3 Vibratory V-15 Min/Pile.. 0.5 15 0.5
HDD East Side. small barges/ Hammer.
vessels
alongside
prior to
fender piles
being
installed.
30.48....... Ambrose Channel Support Barge Tie up and 36-48 4 Vibratory V-15 Min/Pile.. 1 15 1
HDD East Side. Fender Piles. breast support Hammer.
barge
alongside HDD
operations.
30.48....... Ambrose Channel HDD Drill Support HDD 24 10 Vibratory V-15 Min/Pile.. 1.5 5 2
HDD East Side. String Goal string. Hammer.
Posts.
30.48....... Ambrose Channel Pipelay Barge Assist pipelay 60 1 Vibratory V-15 Min/Pile 0.5 15 1
HDD East Side. Mooring Pile. barge with Hammer. \f\.
mooring at
Ambrose East.
34.5 to MP34.5 to Pipelay Barge Assist pipelay 34 4 Vibratory & V-15 Min/Pile.. 3 15 2
35.04. MP35.04. Mooring Pile. barge with Diesel Impact I-52 Min/Pile
mooring. Hammer. \e\.
[[Page 45959]]
35.04....... Neptune Power Crossing Pile.. Ensure 10 2 Vibratory V-15 Min/Pile.. 1 15 1
Cable Crossing temporary Hammer.
(MP35.04). stability of
pipeline at
crossing
location.
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Underwater sound produced during impact pile driving and vibratory
driving and removal could result in incidental take of marine mammals
by Level B harassment and, for some species, Level A harassment.
Proposed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see Proposed
Mitigation and Proposed Monitoring and Reporting).
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the IHA 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' Stock Assessment Reports (SARs;
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'
website (www.fisheries.noaa.gov/find-species).
There are 42 marine mammal species that have been documented within
the U.S. Atlantic Exclusive Economic Zone (EEZ). However, 29 of these
species are not expected to occur within the project area, based on a
lack of sightings in the area and their known habitat preferences and
distributions, which are generally further offshore and at greater
depths than the project area. These are: The blue whale (Balaenoptera
musculus), sei whale (Balaenoptera borealis), Bryde's whale
(Balaenoptera edeni), sperm whale (Physeter macrocephalus), dwarf and
pygmy sperm whale (Kogia sima and Kogia breviceps), beluga whale
(Delphinapterus leucas), northern bottlenose whale (Hyperoodon
ampullatus), killer whale (Orcinus orca), pygmy killer whale (Feresa
attenuata), false killer whale (Pseudorca crassidens), melon-headed
whale (Peponocephala electra), Risso's dolphin (Grampus griseus),
striped dolphin (Stenella coeruleoalba), Atlantic spotted dolphin
(Stenella frontalis), white-beaked dolphin (Lagenorhynchus
albirostris), pantropical spotted dolphin (Stenella attenuata),
Fraser's dolphin (Lagenodelphis hosei), rough-toothed dolphin (Steno
bredanensis), Clymene dolphin (Stenella clymene), spinner dolphin
(Stenella longirostris), hooded seal (Cystophora cristata), ringed seal
(Pusa hipsida), Cuvier's beaked whale (Ziphius cavirostris), four
species of Mesoplodont beaked whale (Mesoplodon spp.), and the West
Indian manatee (Trichechus manatus latirostris) (which occurs further
south than the project area). These species are not analyzed further in
this document.
There are 13 marine mammal species that could potentially occur in
the proposed project area and that are included in Table 10 of the IHA
application. However, the temporal and/or spatial occurrence of three
of the species listed in Table 10 of the IHA application is such that
take of these species is not expected to occur, and they are therefore
not discussed further beyond the explanation provided here. Take of
these species is not anticipated either because they have very low
densities in the project area, or because of their likely occurrence in
habitat that is outside the project area, based on the best available
information. The Atlantic white-sided dolphin (Lagenorhynchus acutus)
occurs throughout temperate and sub-polar waters of the North Atlantic,
most prominently in continental shelf waters to depths of approximately
100 m (330 ft) (Hayes et al., 2018). Though recent survey data in
unavailable, Atlantic white-sided dolphins were found primarily east
and north of Long Island and the project area based on observations
made during the Cetaceans and Turtle Assessment Program (CeTAP) surveys
from 1978 to 1982 (CeTAP, 1982). The Atlantic white-sided dolphins
observed south of Long Island were farther offshore in the deeper water
of the continental shelf proper and closer to the continental shelf
slope. There are two pilot whale species in the western North Atlantic:
The long-finned pilot whale (Globicephala melas melas), and short-
finned pilot whale (Globicephala macrorhynchus). The latitudinal ranges
of the two species remain uncertain, although south of Cape Hatteras,
most pilot whale sightings are expected to be short-finned pilot
whales, while north of ~42[deg] N most pilot whale sightings are
expected to be long-finned pilot whales, and the two species overlap
spatially along the mid-Atlantic shelf break between New Jersey and the
southern flank of Georges Bank (Hayes et al., 2018). The available data
suggests that long-finned pilot whales are more common along the
continental shelf off the northeast coast of the United States during
winter and early spring, and move into the more northerly waters of
Georges Bank and the Gulf of Maine from late spring through autumn
(CeTAP, 1982). Both species prefer deeper offshore waters compared to
the relatively shallow waters of the project area, are not often
observed in the waters overlying the continental shelf proper and are
more commonly seen at the continental shelf break and farther offshore
on the slope. As these species are not expected to occur in the project
area during the proposed activities, they are not discussed further in
this document.
We expect that the species listed in Table 2 will potentially occur
in the project area and will potentially be taken as a result of the
proposed project. Table 2 summarizes information related to the
population or stock, including regulatory status under the MMPA and ESA
and potential biological removal (PBR), where known. For taxonomy, we
follow Committee on Taxonomy (2018). PBR is defined by the MMPA as the
maximum number of animals, not including natural mortalities, that may
be removed from a marine mammal stock while allowing that stock to
reach or maintain its optimum sustainable population (as described in
NMFS' SARs). While no mortality is anticipated or authorized here, PBR
is included here as a gross indicator 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
[[Page 45960]]
number estimated within a particular study or survey area. NMFS' stock
abundance estimates for most species represent the total estimate of
individuals within the geographic area, if known, that comprises that
stock. For some species, this geographic area may extend beyond U.S.
waters. All managed stocks in this region are assessed in NMFS' U.S.
Atlantic SARs. All values presented in Table 2 are the most recent
available at the time of publication and are available in the 2017
Atlantic SARs (Hayes et al., 2018) or draft 2018 SARs, available online
at: www.fisheries.noaa.gov/action/2018-draft-marine-mammal-stock-assessment-reports-available.
Table 2--Marine Mammals Known To Occur in the Project Area That May Be Affected by the Proposed Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
MMPA and ESA Stock abundance
status; (CV, Nmin, most Predicted abundance PBR Annual M/ Occurrence and
Common name (scientific name) Stock strategic (Y/ recent abundance (CV) \3\ \4\ SI \4\ seasonality in
N) \1\ survey) \2\ project area
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Toothed whales (Odontoceti)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bottlenose dolphin (Tursiops W. North Atlantic, -; N 77,532 (0.40; \5\ 97,476 (0.06).... 561 39.4 Rare in summer;
truncatus). Offshore. 56,053; 2011). absent in winter.
W. North Atlantic -; N 6,639 (0.41; 4,759; 48 unknown Common year round.
Coastal Migratory. 2015).
Common dolphin \6\ (Delphinus W. North Atlantic.. -; N 173,486 (0.55; 86,098 (0.12)........ 557 406 Common year round.
delphis). 55,690; 2011).
Harbor porpoise (Phocoena Gulf of Maine/Bay -; N 79,833 (0.32; * 45,089 (0.12)...... 706 255 Common year round.
phocoena). of Fundy. 61,415; 2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baleen whales (Mysticeti)
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Atlantic right whale W. North Atlantic.. E; Y 451 (0; 455; n/a).. * 535 (0.45)......... 0.9 56 Year round in
(Eubalaena glacialis). continental shelf
and slope waters,
occur seasonally.
Humpback whale \7\ (Megaptera Gulf of Maine...... -; N 896 (0.42; 239; n/ * 1,637 (0.07)....... 14.6 9.8 Common year round.
novaeangliae). a).
Minke whale \6\ (Balaenoptera Canadian East Coast -; N 20,741 (0.3; 1,425; * 2,112 (0.05)....... 14 7.5 Year round in
acutorostrata). n/a). continental shelf
and slope waters,
occur seasonally.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Earless seals (Phocidae)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray seal \8\ (Halichoerus W. North Atlantic.. -; N 27,131 (0.10; ..................... 1,389 5,688 Common year round.
grypus). 25,908; n/a).
Harbor seal (Phoca vitulina).... W. North Atlantic.. -; N 75,834 (0.15; ..................... 2,006 345 Common year round.
66,884; 2012).
Harp seal (Pagophilus W. North Atlantic.. -; N 7,411,000 (unk.; unk 225,687 Rare.
groenlandicus). unk; 2014).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR (see
footnote 3) 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\ Stock abundance as reported in NMFS marine mammal stock assessment reports (SAR) except where otherwise noted. SARs available online at:
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments. CV is coefficient of variation; Nmin is the minimum estimate
of stock abundance. In some cases, CV is not applicable. For certain stocks, abundance estimates are actual counts of animals and there is no
associated CV. The most recent abundance survey that is reflected in the abundance estimate is presented; there may be more recent surveys that have
not yet been incorporated into the estimate. All values presented here are from the 2018 draft Atlantic SARs.
\3\ This information represents species- or guild-specific abundance predicted by recent habitat-based cetacean density models (Roberts et al., 2016,
2017, 2018). These models provide the best available scientific information regarding predicted density patterns of cetaceans in the U.S. Atlantic
Ocean, and we provide the corresponding abundance predictions as a point of reference. Total abundance estimates were produced by computing the mean
density of all pixels in the modeled area and multiplying by its area. For those species marked with an asterisk, the available information supported
development of either two or four seasonal models; each model has an associated abundance prediction. Here, we report the maximum predicted abundance.
\4\ Potential biological removal, 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 size (OSP). Annual M/SI, found in NMFS' SARs,
represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial fisheries, subsistence hunting, ship
strike). Annual M/SI values often cannot be determined precisely and is in some cases presented as a minimum value. All M/SI values are as presented
in the draft 2018 SARs.
\5\ Abundance estimates are in some cases reported for a guild or group of species when those species are difficult to differentiate at sea. Similarly,
the habitat-based cetacean density models produced by Roberts et al. (2016) are based in part on available observational data which, in some cases, is
limited to genus or guild in terms of taxonomic definition. Roberts et al. (2016) produced a density model for bottlenose dolphins that does not
differentiate between offshore and coastal stocks.
\6\ Abundance as reported in the 2007 Canadian Trans-North Atlantic Sighting Survey (TNASS), which provided full coverage of the Atlantic Canadian coast
(Lawson and Gosselin, 2009). Abundance estimates from TNASS were corrected for perception and availability bias, when possible. In general, where the
TNASS survey effort provided superior coverage of a stock's range (as compared with NOAA shipboard survey effort), the resulting abundance estimate is
considered more accurate than the current NMFS abundance estimate (derived from survey effort with inferior coverage of the stock range). NMFS stock
abundance estimate for the common dolphin is 70,184. NMFS stock abundance estimate for the fin whale is 1,618. NMFS stock abundance estimate for the
minke whale is 2,591.
\7\ 2018 U.S. Atlantic draft SAR for the Gulf of Maine feeding population lists a current abundance estimate of 896 individuals. However, we note that
the estimate is defined on the basis of feeding location alone (i.e., Gulf of Maine) and is therefore likely an underestimate.
\8\ NMFS stock abundance estimate applies to U.S. population only, actual stock abundance is approximately 505,000.
Two marine mammal species that are listed under the Endangered
Species Act (ESA) may be present in the project area and may be taken
incidental to the proposed activity: The North Atlantic right whale and
fin whale.
Below is a description of the species that have the highest
likelihood of occurring in the project area and are thus expected to
potentially be taken by the proposed activities. For the majority of
species potentially present in the specific geographic region, NMFS has
designated only a single generic stock
[[Page 45961]]
(e.g., ``western North Atlantic'') for management purposes. This
includes the ``Canadian east coast'' stock of minke whales, which
includes all minke whales found in U.S. waters is also a generic stock
for management purposes. For humpback whales, NMFS defines stocks on
the basis of feeding locations, i.e., Gulf of Maine. However,
references to humpback whales in this document refer to any individuals
of the species that are found in the specific geographic region. Any
biologically important areas (BIAs) that overlap spatially with the
project area are addressed in the species sections below.
North Atlantic Right Whale
The North Atlantic right whale ranges from calving grounds in the
southeastern United States to feeding grounds in New England waters and
into Canadian waters (Hayes et al., 2018). Surveys have demonstrated
the existence of seven areas where North Atlantic right whales
congregate seasonally, including north and east of the proposed project
area in Georges Bank, off Cape Cod, and in Massachusetts Bay (Hayes et
al., 2018). In the late fall months (e.g., October), right whales are
generally thought to depart from the feeding grounds in the North
Atlantic and move south to their calving grounds off Georgia and
Florida. However, recent research indicates our understanding of their
movement patterns remains incomplete (Davis et al. 2017). A review of
passive acoustic monitoring data from 2004 to 2014 throughout the
western North Atlantic demonstrated nearly continuous year-round right
whale presence across their entire habitat range (for at least some
individuals), including in locations previously thought of as migratory
corridors, suggesting that not all of the population undergoes a
consistent annual migration (Davis et al. 2017). In recent years, right
whales have been observed off Long Island during the summer, outside of
the migration period (NEFSC, 2019). According to the NMFS Northeast
Fisheries Science Center's (NEFSC) North Atlantic Right Whale Sighting
Advisory System, 50 right whale observations were reported in the
waters south of Long Island and north of New Jersey between May 2004
and May 2019, with 6 observations in the project area (NEFSC, 2019).
The project area is not a known feeding area for right whales and right
whales are not expected to be foraging along the southern coast of Long
Island, including the project area, as their main prey species are
typically concentrated in offshore waters several miles seaward of the
Project area, and right whale foraging behavior has never been
documented near the coast of Long Island. Therefore, any right whales
in the vicinity of the project area are expected to be transient, most
likely migrating through the area.
The western North Atlantic population demonstrated overall growth
of 2.8 percent per year between 1990 to 2010, despite a decline in 1993
and no growth between 1997 and 2000 (Pace et al. 2017). However, since
2010 the population has been in decline, with a 99.99 percent
probability of a decline of just under 1 percent per year (Pace et al.
2017). Between 1990 and 2015, calving rates varied substantially, with
low calving rates coinciding with all three periods of decline or no
growth (Pace et al. 2017). On average, North Atlantic right whale
calving rates are estimated to be roughly half that of southern right
whales (Eubalaena australis) (Pace et al. 2017), which are increasing
in abundance (NMFS 2015). In 2018, no new North Atlantic right whale
calves were documented in their calving grounds; this represented the
first time since annual NOAA aerial surveys began in 1989 that no new
right whale calves were observed. Seven right whale calves were
documented in 2019. The current best estimate of population abundance
for the species is 411 individuals, based on data as of September 4,
2018 (Pettis et al., 2018).
Elevated North Atlantic right whale mortalities have occurred since
June 7, 2017 along the U.S. and Canadian coast. A total of 27 confirmed
dead stranded whales (19 in Canada; 8 in the United States) have been
documented. This event has been declared an Unusual Mortality Event
(UME), with human interactions, including entanglement in fixed fishing
gear and vessel strikes, implicated in at least 13 of the mortalities
thus far. More information is available online at:
www.fisheries.noaa.gov/national/marine-life-distress/2017-2019-north-atlantic-right-whale-unusual-mortality-event.
NMFS' regulations at 50 CFR 224.105 designated nearshore waters of
the Mid-Atlantic Bight as Mid-Atlantic U.S. Seasonal Management Areas
(SMA) for right whales in 2008. SMAs were developed to reduce the
threat of collisions between ships and right whales around their
migratory route and calving grounds. A portion of one SMA, which is
associated with the port of New York and New Jersey, overlaps spatially
with the easternmost part of the project area (see Figure 7 in the IHA
application). The SMA that occurs off New York and New Jersey is active
from November 1 through April 30 of each year.
Fin Whale
Fin whales are common in waters of the U. S. Atlantic EEZ,
principally from Cape Hatteras northward (Waring et al., 2016). Fin
whales are present north of 35-degree latitude in every season and are
broadly distributed throughout the western North Atlantic for most of
the year, though densities vary seasonally (Waring et al., 2016). Fin
whales are found in small groups of up to five individuals (Brueggeman
et al., 1987). Fin whales have been observed in the waters off the
eastern end of Long Island, but are more common in deeper waters and
would not be expected to occur within Raritan Bay.
Humpback Whale
Humpback whales are found worldwide in all oceans. Humpback whales
were listed as endangered under the Endangered Species Conservation Act
(ESCA) in June 1970. In 1973, the ESA replaced the ESCA, and humpbacks
continued to be listed as endangered. NMFS recently evaluated the
status of the species, and on September 8, 2016, NMFS divided the
species into 14 distinct population segments (DPS), removed the current
species-level listing, and in its place listed four DPSs as endangered
and one DPS as threatened (81 FR 62259; September 8, 2016). The
remaining nine DPSs were not listed. The West Indies DPS, which is not
listed under the ESA, is the only DPS of humpback whale that is
expected to occur in the project area.
There have been anecdotal reports of increased sightings of live
humpback whales in the project area (Hynes, 2016; Brown et al., 2018a).
Between 2011 and 2016, there have been at least 46 humpback whale
sightings within Lower New York Bay, Upper New York Bay, and Raritan
Bay (Brown et al., 2018a). Most sightings occurred during the summer
months (July to September), with no documented sightings in the winter
(Brown et al., 2018). A total of 617 humpback whale sightings were
reported within the New York Bight based on data collected from 2011-
2017 (Brown et al., 2018). During winter, the majority of humpback
whales from North Atlantic feeding areas mate and calve in the West
Indies, where spatial and genetic mixing among feeding groups occurs,
though significant numbers of animals are found in mid- and high-
latitude regions at this time and some individuals have been sighted
repeatedly within the same winter season, indicating that not all
humpback
[[Page 45962]]
whales migrate south every winter (Hayes et al., 2018).
Since January 2016, elevated humpback whale mortalities have
occurred along the Atlantic coast from Maine to Florida. Partial or
full necropsy examinations have been conducted on approximately half of
the 99 known cases. Of the whales examined, about 50 percent had
evidence of human interaction, either ship strike or entanglement.
While a portion of the whales have shown evidence of pre-mortem vessel
strike, this finding is not consistent across all whales examined and
more research is needed. NOAA is consulting with researchers that are
conducting studies on the humpback whale populations, and these efforts
may provide information on changes in whale distribution and habitat
use that could provide additional insight into how these vessel
interactions occurred. Three previous UMEs involving humpback whales
have occurred since 2000, in 2003, 2005, and 2006. More information is
available at: www.fisheries.noaa.gov/national/marine-life-distress/2016-2019-humpback-whale-unusual-mortality-event-along-atlantic-coast.
Minke Whale
Minke whales occur in temperate, tropical, and high-latitude
waters. The Canadian East Coast stock can be found in the area from the
western half of the Davis Strait (45[deg] W) to the Gulf of Mexico
(Hayes et al., 2018). This species generally occupies waters less than
100 m deep on the continental shelf. There appears to be a strong
seasonal component to minke whale distribution (Hayes et al., 2018).
During spring and summer, they appear to be widely distributed from
just east of Montauk Point, Long Island, northeast to Nantucket Shoals,
and north towards Stellwagen Bank and Jeffrey's Ledge (CeTAP, 1982).
During the fall, their range is much smaller and their abundance is
reduced throughout their range (CeTAP, 1982). During the winter, they
are largely absent from the vicinity of the project area (Waring et
al., 2012).
Since January 2017, elevated minke whale mortalities have occurred
along the Atlantic coast from Maine through South Carolina, with a
total of 61 strandings recorded when this document was written. This
event has been declared a UME. Full or partial necropsy examinations
were conducted on more than 60 percent of the whales. Preliminary
findings in several of the whales have shown evidence of human
interactions or infectious disease, but these findings are not
consistent across all of the whales examined, so more research is
needed. More information is available at: www.fisheries.noaa.gov/national/marine-life-distress/2017-2019-minke-whale-unusual-mortality-event-along-atlantic-coast.
Common Dolphin
The common dolphin is found world-wide in temperate to subtropical
seas. In the North Atlantic, common dolphins are typically found over
the continental shelf between the 100-m and 2,000-m isobaths and over
prominent underwater topography and east to the mid-Atlantic Ridge
(Hayes et al., 2018), but may be found in shallower shelf waters as
well. Common dolphins occur primarily east and north of Long Island and
may occur in the project area during all seasons (CeTAP, 1982). Between
2011 and 2015, 68 common dolphins stranded in New York and 53 stranded
in New Jersey (Hayes et al., 2018). During 2013, 23 common dolphins
stranded along the Long Island coast (RFMRP 2014).
Bottlenose Dolphin
There are two distinct bottlenose dolphin mophotypes in the western
North Atlantic: The coastal and offshore forms (Hayes et al., 2018).
The two mophotypes are genetically distinct based upon both
mitochondrial and nuclear markers (Hoelzel et al. 1998; Rosel et al.
2009). The offshore form is distributed primarily along the outer
continental shelf and continental slope in waters greater than 40 m
from Georges Bank to the Florida Keys (Hayes et al., 2018). The Western
North Atlantic Northern Migratory Coastal stock occupies coastal waters
from the shoreline to approximately the 20-m isobath between
Assateague, Virginia, and Long Island, New York during warm water
months. The stock migrates in late summer and fall and, during cold
water months (best described by January and February), occupies coastal
waters from approximately Cape Lookout, North Carolina, to the North
Carolina/Virginia border (Garrison et al., 2017). Based on the known
distribution of the Western North Atlantic Northern Migratory Coastal
stock, this stock could potentially occur in the vicinity of the
project during area during the the proposed project; however, Sandy
Hook, NJ (southeast of Raritan Bay) represents the northern extent of
the stock's range, and there have been no confirmed sightings of the
stock within the project area itself (Hayes et al., 2018).
Harbor Porpoise
Harbor porpoises occur from the coastline to deep waters (>1800 m;
Westgate et al. 1998), although the majority of the population is found
over the continental shelf in waters less than 150 m (Hayes et al.,
2018). In the project area, only the Gulf of Maine/Bay of Fundy stock
of harbor porpoise may be present. This stock is found in U.S. and
Canadian Atlantic waters and is concentrated in the northern Gulf of
Maine and southern Bay of Fundy region, but their range extends to
North Carolina, depending on the season (Hayes et al. 2018). In 2011,
six sightings were recorded inside Long Island Sound with one sighting
recorded just outside the Sound (NEFSC and SEFSC, 2011). Between 2011
and 2015, 33 harbor porpoises stranded in New York and 17 stranded in
New Jersey (Hayes et al., 2018).
Harbor Seal
The harbor seal is found in all nearshore waters of the North
Atlantic and North Pacific Oceans and adjoining seas above about
30[deg] N (Burns, 2009). In the western North Atlantic, harbor seals
are distributed from the eastern Canadian Arctic and Greenland south to
southern New England and New York, and occasionally to the Carolinas
(Hayes et al., 2018). Their presence in the region of the project area
is seasonal, with increasing numbers from October to March and a peak
in mid-March (Hoover et al., 2013), when adults, sub-adults, and
juveniles are expected to migrate south from Maine. They return north
to the coastal waters of Maine and Canada in late spring (Katona et
al., 1993). The closest known haulout sites for harbor seals in the
vicinity of the project area are located 2.9 km (1. 8 mi) southwest of
the Ambrose Channel Crossing site (Sandy Hook Beach) and 16.1 km (10
statute miles) east of the MP14.5 to MP16.5 site (Sandy Hook Beach),
with additional haulout sites along the neighboring islands to the
north (CRESLI, 2019). The Coastal Research and Education Society of
Long Island (CRESLI) has monitored seal populations in the project area
for over 15 years and continues to conduct behavioral and population
studies of seals around Long Island, including regular observations at
a major haulout site at Cupsogue Beach Park, located approximately 96.6
km (60 mi) north of the project area on the eastern shore of Long
Island. There are approximately 26 haulout locations around Long
Island, and CRESLI has documented a total of 18,321 harbor seals during
334 surveys since 2004 (CRESLI, 2019).
Since July 2018, elevated numbers of harbor seal and gray seal
mortalities have occurred across Maine, New Hampshire and
Massachusetts. This
[[Page 45963]]
event has been declared a UME. Additionally, stranded seals have shown
clinical signs as far south as Virginia, although not in elevated
numbers, therefore the UME investigation now encompasses all seal
strandings from Maine to Virginia. Lastly, ice seals (harp and hooded
seals) have also started stranding with clinical signs, again not in
elevated numbers, and those two seal species have also been added to
the UME investigation. A total of 1,593 reported strandings (of all
species) had occurred as of the writing of this document. Full or
partial necropsy examinations have been conducted on some of the seals
and samples have been collected for testing. Based on tests conducted
thus far, the main pathogen found in the seals is phocine distemper
virus. NMFS is performing additional testing to identify any other
factors that may be involved in this UME. Information on this UME is
available online at: www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2019-pinniped-unusual-mortality-event-along.
Gray Seal
There are three major populations of gray seals found in the world;
eastern Canada (western North Atlantic stock), northwestern Europe and
the Baltic Sea. Gray seals in the project area belong to the western
North Atlantic stock. The range for this stock is from New Jersey to
Labrador. Current population trends show that gray seal abundance is
likely increasing in the U.S. Atlantic EEZ (Hayes et al., 2018).
Although the rate of increase is unknown, surveys conducted since their
arrival in the 1980s indicate a steady increase in abundance in both
Maine and Massachusetts (Hayes et al., 2018). It is believed that
recolonization by Canadian gray seals is the source of the U.S.
population (Hayes et al., 2018). The closest known haulout sites for
gray seals in the vicinity of the project area are located 2.9 km (1.8
mi) southwest of the Ambrose Channel Crossing site (Sandy Hook Beach)
and 16.1 km (10 mi) east of the MP14.5 to MP16.5 site (Sandy Hook
Beach). Additional haulout sites are likely Little Gull Island in the
Long Island Sound (CRESLI, 2019). Gray seals also haul out on Great
Gull Island and Little Gull Island in eastern Long Island Sound
(DiGiovanni et al., 2015).
As described above, elevated seal mortalities, including gray
seals, have occurred from Maine to Virginia since July 2018. This event
has been declared a UME, with phocine distemper virus identified as the
main pathogen found in the seals. NMFS is performing additional testing
to identify any other factors that may be involved in this UME.
Information on this UME is available online at: www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2019-pinniped-unusual-mortality-event-along.
Harp Seal
Harp seals are highly migratory and occur throughout much of the
North Atlantic and Arctic Oceans (Hayes et al., 2018). Breeding occurs
between late-February and April and adults then assemble on suitable
pack ice to undergo the annual molt. The migration then continues north
to Arctic summer feeding grounds. Harp seal occurrence in the project
area is considered rare. However, since the early 1990s, numbers of
sightings and strandings have been increasing off the east coast of the
United States from Maine to New Jersey (Katona et al. 1993; Rubinstein
1994; Stevick and Fernald 1998; McAlpine 1999; Lacoste and Stenson
2000; Soulen et al. 2013). These extralimital appearances usually occur
in January-May (Harris et al. 2002), when the western North Atlantic
stock is at its most southern point of migration. Between 2011 and
2015, 78 harp seals stranded (mortalities) in New York and 22 stranded
(mortalities) in New Jersey (Hayes et al., 2018). During 2013, eight
harp seals stranded (mortalities and alive) on Long Island (RFMRP,
2014). All of those strandings occurred between January and June.
As described above, elevated seal mortalities, including harp
seals, have occurred across Maine, New Hampshire and Massachusetts, and
as far south as Virginia, since July 2018. This event has been declared
a UME, with phocine distemper virus identified as the main pathogen
found in the seals. NMFS is performing additional testing to identify
any other factors that may be involved in this UME. Information on this
UME is available online at: www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2019-pinniped-unusual-mortality-event-along.
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, 2019) recommended that marine mammals be
divided into functional hearing groups based on directly measured or
estimated hearing ranges on the basis of available behavioral response
data, audiograms derived using auditory evoked potential techniques,
anatomical modeling, and other data. Note that no direct measurements
of hearing ability have been successfully completed for mysticetes
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65
decibel (dB) threshold from the normalized composite audiograms, with
the exception for lower limits for low-frequency cetaceans where the
lower bound was deemed to be biologically implausible and the lower
bound from Southall et al. (2007) retained. Marine mammal hearing
groups and their associated hearing ranges are provided in Table 3.
Table 3--Marine Mammal Hearing Groups (NMFS, 2018)
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans (dolphins, 150 Hz to 160 kHz.
toothed whales, beaked whales, bottlenose
whales).
High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
cephalorhynchid, Lagenorhynchus cruciger &
L. australis).
Phocid pinnipeds (PW) (underwater) (true 50 Hz to 86 kHz.
seals).
[[Page 45964]]
Otariid pinnipeds (OW) (underwater) (sea 60 Hz to 39 kHz.
lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al. 2007) and PW pinniped (approximation).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Nine marine mammal species (six cetacean and three pinniped (all phocid
species)) have the reasonable potential to co-occur with the proposed
activities. Please refer to Table 2. Of the cetacean species that may
be present, three are classified as low-frequency cetaceans (i.e., all
mysticete species), two are classified as mid-frequency cetaceans
(i.e., all delphinid species), and one is classified as a high-
frequency cetacean (i.e., harbor porpoise).
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section includes a summary and discussion of the ways that
components of the specified activity may impact marine mammals and
their habitat. The Estimated Take section later in this document
includes a quantitative analysis of the number of individuals that are
expected to be taken by this activity. The Negligible Impact Analysis
and Determination section considers the content of this section, the
Estimated Take section, and the Proposed Mitigation section, to draw
conclusions regarding the likely impacts of these activities on the
reproductive success or survivorship of individuals and how those
impacts on individuals are likely to impact marine mammal species or
stocks.
Description of Sound Sources
This section contains a brief technical background on sound, on the
characteristics of certain sound types, and on metrics used in this
proposal inasmuch as the information is relevant to the specified
activity and to a discussion of the potential effects of the specified
activity on marine mammals found later in this document. For general
information on sound and its interaction with the marine environment,
please see, e.g., Au and Hastings (2008); Richardson et al. (1995);
Urick (1983).
Sound travels in waves, the basic components of which are
frequency, wavelength, velocity, and amplitude. Frequency is the number
of pressure waves that pass by a reference point per unit of time and
is measured in hertz (Hz) or cycles per second. Wavelength is the
distance between two peaks or corresponding points of a sound wave
(length of one cycle). Higher frequency sounds have shorter wavelengths
than lower frequency sounds, and typically attenuate (decrease) more
rapidly, except in certain cases in shallower water. Amplitude is the
height of the sound pressure wave or the ``loudness'' of a sound and is
typically described using the relative unit of the decibel (dB). A
sound pressure level (SPL) in dB is described as the ratio between a
measured pressure and a reference pressure (for underwater sound, this
is 1 microPascal ([mu]Pa)), and is a logarithmic unit that accounts for
large variations in amplitude; therefore, a relatively small change in
dB corresponds to large changes in sound pressure. The source level
(SL) represents the SPL referenced at a distance of 1 m from the source
(referenced to 1 [mu]Pa), while the received level is the SPL at the
listener's position (referenced to 1 [mu]Pa).
Root mean square (rms) is the quadratic mean sound pressure over
the duration of an impulse. Root mean square is calculated by squaring
all of the sound amplitudes, averaging the squares, and then taking the
square root of the average (Urick, 1983). Root mean square accounts for
both positive and negative values; squaring the pressures makes all
values positive so that they may be accounted for in the summation of
pressure levels (Hastings and Popper, 2005). This measurement is often
used in the context of discussing behavioral effects, in part because
behavioral effects, which often result from auditory cues, may be
better expressed through averaged units than by peak pressures.
Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s)
represents the total energy in a stated frequency band over a stated
time interval or event, and considers both intensity and duration of
exposure. The per-pulse SEL is calculated over the time window
containing the entire pulse (i.e., 100 percent of the acoustic energy).
SEL is a cumulative metric; it can be accumulated over a single pulse,
or calculated over periods containing multiple pulses. Cumulative SEL
represents the total energy accumulated by a receiver over a defined
time window or during an event. Peak sound pressure (also referred to
as zero-to-peak sound pressure or 0-pk) is the maximum instantaneous
sound pressure measurable in the water at a specified distance from the
source, and is represented in the same units as the rms sound pressure.
When underwater objects vibrate or activity occurs, sound-pressure
waves are created. These waves alternately compress and decompress the
water as the sound wave travels. Underwater sound waves radiate in a
manner similar to ripples on the surface of a pond and may be either
directed in a beam or beams or may radiate in all directions
(omnidirectional sources), as is the case for sound produced by the
pile driving activity considered here. The compressions and
decompressions associated with sound waves are detected as changes in
pressure by aquatic life and man-made sound receptors such as
hydrophones.
Even in the absence of sound from the specified activity, the
underwater environment is typically loud due to ambient sound, which is
defined as environmental background sound levels lacking a single
source or point (Richardson et al., 1995). The sound level of a region
is defined by the total acoustical energy being generated by known and
unknown sources. These sources may include physical (e.g., wind and
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds
produced by marine mammals, fish, and invertebrates), and anthropogenic
(e.g., vessels, dredging, construction) sound. A number of sources
contribute to ambient sound, including wind and waves, which are a main
source of naturally occurring ambient sound for frequencies between 200
hertz (Hz) and 50 kilohertz (kHz) (Mitson, 1995). In general, ambient
[[Page 45965]]
sound levels tend to increase with increasing wind speed and wave
height. Precipitation can become an important component of total sound
at frequencies above 500 Hz, and possibly down to 100 Hz during quiet
times. Marine mammals can contribute significantly to ambient sound
levels, as can some fish and snapping shrimp. The frequency band for
biological contributions is from approximately 12 Hz to over 100 kHz.
Sources of ambient sound related to human activity include
transportation (surface vessels), dredging and construction, oil and
gas drilling and production, geophysical surveys, sonar, and
explosions. Vessel noise typically dominates the total ambient sound
for frequencies between 20 and 300 Hz. In general, the frequencies of
anthropogenic sounds are below 1 kHz and, if higher frequency sound
levels are created, they attenuate rapidly.
The sum of the various natural and anthropogenic sound sources that
comprise ambient sound at any given location and time depends not only
on the source levels (as determined by current weather conditions and
levels of biological and human activity) but also on the ability of
sound to propagate through the environment. In turn, sound propagation
is dependent on the spatially and temporally varying properties of the
water column and sea floor, and is frequency-dependent. As a result of
the dependence on a large number of varying factors, ambient sound
levels can be expected to vary widely over both coarse and fine spatial
and temporal scales. Sound levels at a given frequency and location can
vary by 10-20 decibels (dB) from day to day (Richardson et al., 1995).
The result is that, depending on the source type and its intensity,
sound from the specified activity may be a negligible addition to the
local environment or could form a distinctive signal that may affect
marine mammals. Underwater ambient sound in Raritan Bay and the New
York Bight is comprised of sounds produced by a number of natural and
anthropogenic sources. Human-generated sound is a significant
contributor to the ambient acoustic environment in the project
location. Details of source types are described in the following text.
Sounds are often considered to fall into one of two general types:
Pulsed and non-pulsed (defined in the following). The distinction
between these two sound types is important because they have differing
potential to cause physical effects, particularly with regard to
hearing (e.g., Ward, 1997 in Southall et al., 2007). Please see
Southall et al. (2007) for an in-depth discussion of these concepts.
The distinction between these two sound types is not always obvious, as
certain signals share properties of both pulsed and non-pulsed sounds.
A signal near a source could be categorized as a pulse, but due to
propagation effects as it moves farther from the source, the signal
duration becomes longer (e.g., Greene and Richardson, 1988).
Pulsed sound sources (e.g., airguns, explosions, gunshots, sonic
booms, impact pile driving) produce signals that are brief (typically
considered to be less than one second), broadband, atonal transients
(ANSI, 1986, 2005; Harris, 1998; NIOSH, 1998; ISO, 2003) and occur
either as isolated events or repeated in some succession. Pulsed sounds
are all characterized by a relatively rapid rise from ambient pressure
to a maximal pressure value followed by a rapid decay period that may
include a period of diminishing, oscillating maximal and minimal
pressures, and generally have an increased capacity to induce physical
injury as compared with sounds that lack these features.
Non-pulsed sounds can be tonal, narrowband, or broadband, brief or
prolonged, and may be either continuous or intermittent (ANSI, 1995;
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals
of short duration but without the essential properties of pulses (e.g.,
rapid rise time). Examples of non-pulsed sounds include those produced
by vessels, aircraft, machinery operations such as drilling or
dredging, vibratory pile driving, and active sonar systems. The
duration of such sounds, as received at a distance, can be greatly
extended in a highly reverberant environment.
The impulsive sound generated by impact hammers is characterized by
rapid rise times and high peak levels. Vibratory hammers produce non-
impulsive, continuous noise at levels significantly lower than those
produced by impact hammers. Rise time is slower, reducing the
probability and severity of injury, and sound energy is distributed
over a greater amount of time (e.g., Nedwell and Edwards, 2002; Carlson
et al., 2005).
Acoustic Effects
We previously provided general background information on marine
mammal hearing (see ``Description of Marine Mammals in the Area of the
Specified Activity''). Here, we discuss the potential effects of sound
on marine mammals.
Potential Effects of Underwater Sound--Note that, in the following
discussion, we refer in many cases to a review article concerning
studies of noise-induced hearing loss conducted from 1996-2015 (i.e.,
Finneran, 2015). For study-specific citations, please see that work.
Anthropogenic sounds cover a broad range of frequencies and sound
levels and can have a range of highly variable impacts on marine life,
from none or minor to potentially severe responses, depending on
received levels, duration of exposure, behavioral context, and various
other factors. The potential effects of underwater sound from active
acoustic sources can potentially result in one or more of the
following: Temporary or permanent hearing impairment, non-auditory
physical or physiological effects, behavioral disturbance, stress, and
masking (Richardson et al., 1995; Gordon et al., 2004; Nowacek et al.,
2007; Southall et al., 2007; G[ouml]tz et al., 2009). The degree of
effect is intrinsically related to the signal characteristics, received
level, distance from the source, and duration of the sound exposure. In
general, sudden, high level sounds can cause hearing loss, as can
longer exposures to lower level sounds. Temporary or permanent loss of
hearing will occur almost exclusively for noise within an animal's
hearing range. We first describe specific manifestations of acoustic
effects before providing discussion specific to pile driving.
Richardson et al. (1995) described zones of increasing intensity of
effect that might be expected to occur, in relation to distance from a
source and assuming that the signal is within an animal's hearing
range. First is the area within which the acoustic signal would be
audible (potentially perceived) to the animal but not strong enough to
elicit any overt behavioral or physiological response. The next zone
corresponds with the area where the signal is audible to the animal and
of sufficient intensity to elicit behavioral or physiological
responsiveness. Third is a zone within which, for signals of high
intensity, the received level is sufficient to potentially cause
discomfort or tissue damage to auditory or other systems. Overlaying
these zones to a certain extent is the area within which masking (i.e.,
when a sound interferes with or masks the ability of an animal to
detect a signal of interest that is above the absolute hearing
threshold) may occur; the masking zone may be highly variable in size.
We describe the more severe effects (i.e., certain non-auditory
physical or physiological effects) only briefly as we do not expect
that there is a reasonable likelihood that pile driving may result in
such effects (see below for further
[[Page 45966]]
discussion). Potential effects from impulsive sound sources can range
in severity from effects such as behavioral disturbance or tactile
perception to physical discomfort, slight injury of the internal organs
and the auditory system, or mortality (Yelverton et al., 1973). Non-
auditory physiological effects or injuries that theoretically might
occur in marine mammals exposed to high level underwater sound or as a
secondary effect of extreme behavioral reactions (e.g., change in dive
profile as a result of an avoidance reaction) caused by exposure to
sound include neurological effects, bubble formation, resonance
effects, and other types of organ or tissue damage (Cox et al., 2006;
Southall et al., 2007; Zimmer and Tyack, 2007; Tal et al., 2015). The
construction activities considered here do not involve the use of
devices such as explosives or mid-frequency tactical sonar that are
associated with these types of effects.
Threshold Shift--Marine mammals exposed to high-intensity sound, or
to lower-intensity sound for prolonged periods, can experience hearing
threshold shift (TS), which is the loss of hearing sensitivity at
certain frequency ranges (Finneran, 2015). TS can be permanent (PTS),
in which case the loss of hearing sensitivity is not fully recoverable,
or temporary (TTS), in which case the animal's hearing threshold would
recover over time (Southall et al., 2007). Repeated sound exposure that
leads to TTS could cause PTS. In severe cases of PTS, there can be
total or partial deafness, while in most cases the animal has an
impaired ability to hear sounds in specific frequency ranges (Kryter,
1985).
When PTS occurs, there is physical damage to the sound receptors in
the ear (i.e., tissue damage), whereas TTS represents primarily tissue
fatigue and is reversible (Southall et al., 2007). In addition, other
investigators have suggested that TTS is within the normal bounds of
physiological variability and tolerance and does not represent physical
injury (e.g., Ward, 1997). Therefore, NMFS does not consider TTS to
constitute auditory injury.
Relationships between TTS and PTS thresholds have not been studied
in marine mammals, and there is no PTS data for cetaceans, but such
relationships are assumed to be similar to those in humans and other
terrestrial mammals. PTS typically occurs at exposure levels at least
several decibels above (a 40-dB threshold shift approximates PTS onset;
e.g., Kryter et al., 1966; Miller, 1974) that inducing mild TTS (a 6-dB
threshold shift approximates TTS onset; e.g., Southall et al. 2007).
Based on data from terrestrial mammals, a precautionary assumption is
that the PTS thresholds for impulse sounds (such as impact pile driving
pulses as received close to the source) are at least 6 dB higher than
the TTS threshold on a peak-pressure basis and PTS cumulative sound
exposure level thresholds are 15 to 20 dB higher than TTS cumulative
sound exposure level thresholds (Southall et al., 2007). Given the
higher level of sound or longer exposure duration necessary to cause
PTS as compared with TTS, it is considerably less likely that PTS could
occur.
TTS is the mildest form of hearing impairment that can occur during
exposure to sound (Kryter, 1985). While experiencing TTS, the hearing
threshold rises, and a sound must be at a higher level in order to be
heard. In terrestrial and marine mammals, TTS can last from minutes or
hours to days (in cases of strong TTS). In many cases, hearing
sensitivity recovers rapidly after exposure to the sound ends. Few data
on sound levels and durations necessary to elicit mild TTS have been
obtained for marine mammals.
Marine mammal hearing plays a critical role in communication with
conspecifics, and interpretation of environmental cues for purposes
such as predator avoidance and prey capture. Depending on the degree
(elevation of threshold in dB), duration (i.e., recovery time), and
frequency range of TTS, and the context in which it is experienced, TTS
can have effects on marine mammals ranging from discountable to
serious. For example, a marine mammal may be able to readily compensate
for a brief, relatively small amount of TTS in a non-critical frequency
range that occurs during a time where ambient noise is lower and there
are not as many competing sounds present. Alternatively, a larger
amount and longer duration of TTS sustained during time when
communication is critical for successful mother/calf interactions could
have more serious impacts.
Currently, TTS data only exist for four species of cetaceans
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor
porpoise, and Yangtze finless porpoise (Neophocoena asiaeorientalis))
and three species of pinnipeds (northern elephant seal (Mirounga
angustirostris), harbor seal, and California sea lion (Zalophus
californianus)) exposed to a limited number of sound sources (i.e.,
mostly tones and octave-band noise) in laboratory settings (Finneran,
2015). TTS was not observed in trained spotted (Phoca largha) and
ringed (Pusa hispida) seals exposed to impulsive noise at levels
matching previous predictions of TTS onset (Reichmuth et al., 2016). In
general, harbor seals and harbor porpoises have a lower TTS onset than
other measured pinniped or cetacean species (Finneran, 2015).
Additionally, the existing marine mammal TTS data come from a limited
number of individuals within these species. There are no data available
on noise-induced hearing loss for mysticetes. For summaries of data on
TTS in marine mammals or for further discussion of TTS onset
thresholds, please see Southall et al. (2007), Finneran and Jenkins
(2012), Finneran (2015), and NMFS (2018).
Behavioral Effects--Behavioral disturbance may include a variety of
effects, including subtle changes in behavior (e.g., minor or brief
avoidance of an area or changes in vocalizations), more conspicuous
changes in similar behavioral activities, and more sustained and/or
potentially severe reactions, such as displacement from or abandonment
of high-quality habitat. Behavioral responses to sound are highly
variable and context-specific and any reactions depend on numerous
intrinsic and extrinsic factors (e.g., species, state of maturity,
experience, current activity, reproductive state, auditory sensitivity,
time of day), as well as the interplay between factors (e.g.,
Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 2007;
Weilgart, 2007; Archer et al., 2010). Behavioral reactions can vary not
only among individuals but also within an individual, depending on
previous experience with a sound source, context, and numerous other
factors (Ellison et al., 2012), and can vary depending on
characteristics associated with the sound source (e.g., whether it is
moving or stationary, number of sources, distance from the source).
Please see Appendices B-C of Southall et al. (2007) for a review of
studies involving marine mammal behavioral responses to sound.
Habituation can occur when an animal's response to a stimulus wanes
with repeated exposure, usually in the absence of unpleasant associated
events (Wartzok et al., 2003). Animals are most 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
[[Page 45967]]
responses, often in the form of avoidance, at a lower level of
exposure. As noted, behavioral state may affect the type of response.
For example, animals that are resting may show greater behavioral
change in response to disturbing sound levels than animals that are
highly motivated to remain in an area for feeding (Richardson et al.,
1995; NRC, 2003; Wartzok et al., 2003). Controlled experiments with
captive marine mammals have showed pronounced behavioral reactions,
including avoidance of loud sound sources (Ridgway et al., 1997;
Finneran et al., 2003). Observed responses of wild marine mammals to
loud pulsed sound sources (typically airguns or acoustic harassment
devices) have been varied but often consist of avoidance behavior or
other behavioral changes suggesting discomfort (Morton and Symonds,
2002; see also Richardson et al., 1995; Nowacek et al., 2007). However,
many delphinids approach low-frequency airgun source vessels with no
apparent discomfort or obvious behavioral change (e.g., Barkaszi et
al., 2012), indicating the importance of frequency output in relation
to the species' hearing sensitivity.
Available studies show wide variation in response to underwater
sound; therefore, it is difficult to predict specifically how any given
sound in a particular instance might affect marine mammals perceiving
the signal. If a marine mammal does react briefly to an underwater
sound by changing its behavior or moving a small distance, the impacts
of the change are unlikely to be significant to the individual, let
alone the stock or population. However, if a sound source displaces
marine mammals from an important feeding or breeding area for a
prolonged period, impacts on individuals and populations could be
significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007; NRC,
2005). However, there are broad categories of potential response, which
we describe in greater detail here, that include alteration of dive
behavior, alteration of foraging behavior, effects to breathing,
interference with or alteration of vocalization, avoidance, and flight.
Changes in dive behavior can vary widely and may consist of
increased or decreased dive times and surface intervals as well as
changes in the rates of ascent and descent during a dive (e.g., Frankel
and Clark, 2000; Costa et al., 2003; Ng and Leung, 2003; Nowacek et
al.; 2004; Goldbogen et al., 2013a, 2013b). Variations in dive behavior
may reflect interruptions in biologically significant activities (e.g.,
foraging) or they may be of little biological significance. The impact
of an alteration to dive behavior resulting from an acoustic exposure
depends on what the animal is doing at the time of the exposure and the
type and magnitude of the response.
Disruption of feeding behavior can be difficult to correlate with
anthropogenic sound exposure, so it is usually inferred by observed
displacement from known foraging areas, the appearance of secondary
indicators (e.g., bubble nets or sediment plumes), or changes in dive
behavior. As for other types of behavioral response, the frequency,
duration, and temporal pattern of signal presentation, as well as
differences in species sensitivity, are likely contributing factors to
differences in response in any given circumstance (e.g., Croll et al.,
2001; Nowacek et al.; 2004; Madsen et al., 2006; Yazvenko et al.,
2007). A determination of whether foraging disruptions incur fitness
consequences would require information on or estimates of the energetic
requirements of the affected individuals and the relationship between
prey availability, foraging effort and success, and the life history
stage of the animal.
Variations in respiration naturally vary with different behaviors
and alterations to breathing rate as a function of acoustic exposure
can be expected to co-occur with other behavioral reactions, such as a
flight response or an alteration in diving. However, respiration rates
in and of themselves may be representative of annoyance or an acute
stress response. Various studies have shown that respiration rates may
either be unaffected or could increase, depending on the species and
signal characteristics, again highlighting the importance in
understanding species differences in the tolerance of underwater noise
when determining the potential for impacts resulting from anthropogenic
sound exposure (e.g., Kastelein et al., 2001, 2005, 2006; Gailey et
al., 2007; Gailey et al., 2016).
Marine mammals vocalize for different purposes and across multiple
modes, such as whistling, echolocation click production, calling, and
singing. Changes in vocalization behavior in response to anthropogenic
noise can occur for any of these modes and may result from a need to
compete with an increase in background noise or may reflect increased
vigilance or a startle response. For example, in the presence of
potentially masking signals, humpback whales and killer whales have
been observed to increase the length of their songs (Miller et al.,
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales
have been observed to shift the frequency content of their calls upward
while reducing the rate of calling in areas of increased anthropogenic
noise (Parks et al., 2007). In some cases, animals may cease sound
production during production of aversive signals (Bowles et al., 1994).
Avoidance is the displacement of an individual from an area or
migration path as a result of the presence of a sound or other
stressors, and is one of the most obvious manifestations of disturbance
in marine mammals (Richardson et al., 1995). For example, gray whales
are known to change direction--deflecting from customary migratory
paths--in order to avoid noise from airgun surveys (Malme et al.,
1984). Avoidance may be short-term, with animals returning to the area
once the noise has ceased (e.g., Bowles et al., 1994; Goold, 1996;
Stone et al., 2000; Morton and Symonds, 2002; Gailey et al., 2007).
Longer-term displacement is possible, however, which may lead to
changes in abundance or distribution patterns of the affected species
in the affected region if habituation to the presence of the sound does
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann
et al., 2006).
A flight response is a dramatic change in normal movement to a
directed and rapid movement away from the perceived location of a sound
source. The flight response differs from other avoidance responses in
the intensity of the response (e.g., directed movement, rate of
travel). Relatively little information on flight responses of marine
mammals to anthropogenic signals exist, although observations of flight
responses to the presence of predators have occurred (Connor and
Heithaus, 1996). The result of a flight response could range from
brief, temporary exertion and displacement from the area where the
signal provokes flight to, in extreme cases, marine mammal strandings
(Evans and England, 2001). However, it should be noted that response to
a perceived predator does not necessarily invoke flight (Ford and
Reeves, 2008), and whether individuals are solitary or in groups may
influence the response.
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
[[Page 45968]]
reduce feeding rates (e.g., Beauchamp and Livoreil, 1997; Fritz et al.,
2002; Purser and Radford, 2011). In addition, chronic disturbance can
cause population declines through reduction of fitness (e.g., decline
in body condition) and subsequent reduction in reproductive success,
survival, or both (e.g., Harrington and Veitch, 1992; Daan et al.,
1996; Bradshaw et al., 1998). However, Ridgway et al. (2006) reported
that increased vigilance in bottlenose dolphins exposed to sound over a
five-day period did not cause any sleep deprivation or stress effects.
Many animals perform vital functions, such as feeding, resting,
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption
of such functions resulting from reactions to stressors such as sound
exposure are more likely to be significant if they last more than one
diel cycle or recur on subsequent days (Southall et al., 2007).
Consequently, a behavioral response lasting less than one day and not
recurring on subsequent days is not considered particularly severe
unless it could directly affect reproduction or survival (Southall et
al., 2007). Note that there is a difference between multi-day
substantive behavioral reactions and multi-day anthropogenic
activities. For example, just because an activity lasts for multiple
days does not necessarily mean that individual animals are either
exposed to activity-related stressors for multiple days or, further,
exposed in a manner resulting in sustained multi-day substantive
behavioral responses.
Stress Responses--An animal's perception of a threat may be
sufficient to trigger stress responses consisting of some combination
of behavioral responses, autonomic nervous system responses,
neuroendocrine responses, or immune responses (e.g., Seyle, 1950;
Moberg, 2000). In many cases, an animal's first and sometimes most
economical (in terms of energetic costs) response is behavioral
avoidance of the potential stressor. Autonomic nervous system responses
to stress typically involve changes in heart rate, blood pressure, and
gastrointestinal activity. These responses have a relatively short
duration and may or may not have a significant long-term effect on an
animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that
are affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been
implicated in failed reproduction, altered metabolism, reduced immune
competence, and behavioral disturbance (e.g., Moberg, 1987; Blecha,
2000). Increases in the circulation of glucocorticoids are also equated
with stress (Romano et al., 2004).
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and ``distress'' is the cost of
the response. During a stress response, an animal uses glycogen stores
that can be quickly replenished once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other functions. This state of
distress will last until the animal replenishes its energetic reserves
sufficient to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well studied through
controlled experiments and for both laboratory and free-ranging animals
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003;
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to
exposure to anthropogenic sounds or other stressors and their effects
on marine mammals have also been reviewed (Fair and Becker, 2000;
Romano et al., 2002b) and, more rarely, studied in wild populations
(e.g., Romano et al., 2002a). For example, Rolland et al. (2012) found
that noise reduction from reduced ship traffic in the Bay of Fundy was
associated with decreased stress in North Atlantic right whales. These
and other studies lead to a reasonable expectation that some marine
mammals will experience physiological stress responses upon exposure to
acoustic stressors and that it is possible that some of these would be
classified as ``distress.'' In addition, any animal experiencing TTS
would likely also experience stress responses (NRC, 2003).
Auditory Masking--Sound can disrupt behavior through masking, or
interfering with, an animal's ability to detect, recognize, or
discriminate between acoustic signals of interest (e.g., those used for
intraspecific communication and social interactions, prey detection,
predator avoidance, navigation) (Richardson et al., 1995; Erbe et al.,
2016). Masking occurs when the receipt of a sound is interfered with by
another coincident sound at similar frequencies and at similar or
higher intensity, and may occur whether the sound is natural (e.g.,
snapping shrimp, wind, waves, precipitation) or anthropogenic (e.g.,
shipping, sonar, seismic exploration) in origin. The ability of a noise
source to mask biologically important sounds depends on the
characteristics of both the noise source and the signal of interest
(e.g., signal-to-noise ratio, temporal variability, direction), in
relation to each other and to an animal's hearing abilities (e.g.,
sensitivity, frequency range, critical ratios, frequency
discrimination, directional discrimination, age or TTS hearing loss),
and existing ambient noise and propagation conditions.
Under certain circumstances, marine mammals experiencing
significant masking could also be impaired from maximizing their
performance fitness in survival and reproduction. Therefore, when the
coincident (masking) sound is man-made, it may be considered harassment
if disrupting behavioral patterns. It is important to distinguish TTS
and PTS, which persist after the sound exposure, from masking, which
occurs during the sound exposure. Because masking (without resulting in
TS) is not associated with abnormal physiological function, it is not
considered a physiological effect, but rather a potential behavioral
effect.
The frequency range of the potentially masking sound is important
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation
sounds produced by odontocetes but are more likely to affect detection
of mysticete communication calls and other potentially important
natural sounds such as those produced by surf and some prey species.
The masking of communication signals by anthropogenic noise may be
considered as a reduction in the communication space of animals (e.g.,
Clark et al., 2009) and may result in energetic or other costs as
animals change their vocalization behavior (e.g., Miller et al., 2000;
Foote et al., 2004; Parks et al., 2007; Di Iorio and Clark, 2009; Holt
et al., 2009). Masking can be reduced in situations where the signal
and noise come from different directions (Richardson et al., 1995),
through amplitude modulation of the signal, or through other
compensatory behaviors (Houser and Moore, 2014). Masking can be tested
directly in captive species (e.g., Erbe, 2008), but in wild populations
it must be either modeled or inferred from evidence of masking
compensation. There are few studies addressing real-world masking
sounds likely to be experienced by marine
[[Page 45969]]
mammals in the wild (e.g., Branstetter et al., 2013).
Masking affects both senders and receivers of acoustic signals and
can potentially have long-term chronic effects on marine mammals at the
population level as well as at the individual level. Low-frequency
ambient sound levels have increased by as much as 20 dB (more than
three times in terms of SPL) in the world's ocean from pre-industrial
periods, with most of the increase from distant commercial shipping
(Hildebrand, 2009). All anthropogenic sound sources, but especially
chronic and lower-frequency signals (e.g., from vessel traffic),
contribute to elevated ambient sound levels, thus intensifying masking.
Potential Effects of the Specified Activity--As described
previously (see ``Description of Active Acoustic Sound Sources''),
Transco proposes to conduct pile driving and pile removal. The effects
of pile driving and removal on marine mammals are dependent on several
factors, including the size, type, and depth of the animal; the depth,
intensity, and duration of the pile driving sound; the depth of the
water column; the substrate of the habitat; the distance between the
pile and the animal; and the sound propagation properties of the
environment.
Noise generated by impact pile driving consists of regular, pulsed
sounds of short duration. These pulsed sounds are typically high energy
with fast rise times. Exposure to these sounds may result in harassment
depending on proximity to the sound source and a variety of
environmental and biological conditions (Dahl et al. 2015; Nedwell et
al., 2007). Illingworth & Rodkin (2007) measured an unattenuated sound
pressure within 10 m (33 ft) at a peak of 220 dB re 1 [mu]Pa for a 2.4
m (96 in) steel pile driven by an impact hammer. Studies of underwater
sound from pile driving finds that most of the acoustic energy is below
one to two kHz, with broadband sound energy near the source (40 Hz to
>40 kHz) and only low-frequency energy (<~400 Hz) at longer ranges
(Bailey et al., 2010; Erbe, 2009; Illingworth & Rodkin, 2007). There is
typically a decrease in sound pressure and an increase in pulse
duration the greater the distance from the noise source (Bailey et al.,
2010). Maximum noise levels from pile driving usually occur during the
last stage of driving each pile where the highest hammer energy levels
are used (Betke, 2008).
The onset of behavioral disturbance from anthropogenic sound
depends on both external factors (characteristics of sound sources and
their paths) and the specific characteristics of the receiving animals
(hearing, motivation, experience, demography) and is difficult to
predict (Southall et al., 2007). It is possible that the onset of pile
driving could result in temporary, short-term changes in an animal's
typical behavioral patterns and/or temporary avoidance of the affected
area. These behavioral changes may include (Richardson et al., 1995):
Changing durations of surfacing and dives, number of blows per
surfacing, or moving direction and/or speed; reduced/increased vocal
activities; changing/cessation of certain behavioral activities (such
as socializing or feeding); visible startle response or aggressive
behavior (such as tail/fluke slapping or jaw clapping); avoidance of
areas where sound sources are located; and/or flight responses. The
biological significance of many of these behavioral disturbances is
difficult to predict, especially if the detected disturbances appear
minor. However, the consequences of behavioral modification could be
expected to be biologically significant if the change affects growth,
survival, or reproduction. Significant behavioral modifications that
could lead to effects on growth, survival, or reproduction, such as
drastic changes in diving/surfacing patterns or significant habitat
abandonment are considered extremely unlikely in the case of the
proposed project, as it is expected that mitigation measures, including
clearance zones and soft start (described in detail below, see
``Proposed Mitigation Measures'') will minimize the potential for
marine mammals to be exposed to sound levels that would result in more
extreme behavioral responses. In addition, marine mammals in the
project area are expected to avoid any area that would be ensonified at
sound levels high enough for the potential to result in more severe
acute behavioral responses, as the environment within Raritan Bay would
allow marine mammals the ability to freely move to other areas of the
Bay without restriction.
In the case of pile driving, sound sources would be active for
relatively short durations, with relation to potential for masking. The
frequencies output by pile driving activity are lower than those used
by most species expected to be regularly present for communication or
foraging. Those species who would be more susceptible to masking at
these frequencies (LF cetaceans) use the area only seasonally. We
expect insignificant impacts from masking, and any masking event that
could possibly rise to Level B harassment under the MMPA would occur
concurrently within the zones of behavioral harassment already
estimated for pile driving, and which have already been taken into
account in the exposure analysis.
Anticipated Effects on Marine Mammal Habitat
The proposed activities would not result in permanent impacts to
habitats used directly by marine mammals, but may have potential short-
term impacts to food sources such as forage fish. The proposed
activities could also affect acoustic habitat (see masking discussion
above), but meaningful impacts are unlikely. There are no known
foraging hotspots, or other ocean bottom structures of significant
biological importance to marine mammals present in the project area.
Therefore, the main impact issue associated with the proposed activity
would be temporarily elevated sound levels and the associated direct
effects on marine mammals, as discussed previously. The most likely
impact to marine mammal habitat occurs from pile driving effects on
likely marine mammal prey (e.g., fish). Impacts to the immediate
substrate during installation of piles are anticipated, but these would
be limited to minor, temporary suspension of sediments, which could
impact water quality and visibility for a short amount of time, without
any expected effects on individual marine mammals. Impacts to substrate
are therefore not discussed further.
Effects to Prey--Sound may affect marine mammals through impacts on
the abundance, behavior, or distribution of prey species (e.g.,
crustaceans, cephalopods, fish, zooplankton). Marine mammal prey varies
by species, season, and location and, for some, is not well documented.
Here, we describe studies regarding the effects of noise on known
marine mammal prey.
Fish utilize the soundscape and components of sound in their
environment to perform important functions such as foraging, predator
avoidance, mating, and spawning (e.g., Zelick et al., 1999; Fay, 2009).
Depending on their hearing anatomy and peripheral sensory structures,
which vary among species, fishes hear sounds using pressure and
particle motion sensitivity capabilities and detect the motion of
surrounding water (Fay et al., 2008). The potential effects of noise on
fishes depends on the overlapping frequency range, distance from the
sound source, water depth of exposure, and species-specific hearing
sensitivity, anatomy, and physiology. Key impacts to fishes may include
behavioral responses, hearing damage,
[[Page 45970]]
barotrauma (pressure-related injuries), and mortality.
Fish react to sounds which are especially strong and/or
intermittent low-frequency sounds, and behavioral responses such as
flight or avoidance are the most likely effects. Short duration, sharp
sounds can cause overt or subtle changes in fish behavior and local
distribution. The reaction of fish to noise depends on the
physiological state of the fish, past exposures, motivation (e.g.,
feeding, spawning, migration), and other environmental factors.
Hastings and Popper (2005) identified several studies that suggest fish
may relocate to avoid certain areas of sound energy. Additional studies
have documented effects of pile driving on fish, although several are
based on studies in support of large, multiyear bridge construction
projects (e.g., Scholik and Yan, 2001, 2002; Popper and Hastings,
2009). Several studies have demonstrated that impulse sounds might
affect the distribution and behavior of some fishes, potentially
impacting foraging opportunities or increasing energetic costs (e.g.,
Fewtrell and McCauley, 2012; Pearson et al., 1992; Skalski et al.,
1992; Santulli et al., 1999; Paxton et al., 2017). However, some
studies have shown no or slight reaction to impulse sounds (e.g., Pena
et al., 2013; Wardle et al., 2001; Jorgenson and Gyselman, 2009; Cott
et al., 2012). More commonly, though, the impacts of noise on fish are
temporary.
SPLs of sufficient strength have been known to cause injury to fish
and fish mortality. However, in most fish species, hair cells in the
ear continuously regenerate and loss of auditory function likely is
restored when damaged cells are replaced with new cells. Halvorsen et
al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours
for one species. Impacts would be most severe when the individual fish
is close to the source and when the duration of exposure is long.
Injury caused by barotrauma can range from slight to severe and can
cause death, and is most likely for fish with swim bladders. Barotrauma
injuries have been documented during controlled exposure to impact pile
driving (Halvorsen et al., 2012b; Casper et al., 2013).
The most likely impact to fish from pile driving activities in the
project area would be temporary behavioral avoidance of the area. The
duration of fish avoidance of an area after pile driving stops is
unknown, but a rapid return to normal recruitment, distribution and
behavior is anticipated. In general, impacts to marine mammal prey
species are expected to be minor and temporary due to the expected
short daily duration of individual pile driving events and the
relatively small areas being affected.
The area likely impacted by the activities is relatively small
compared to the available habitat in Raritan Bay. Any behavioral
avoidance by fish of the disturbed area would still leave significantly
large areas of fish and marine mammal foraging habitat in the nearby
vicinity. Based on the information discussed herein, we conclude that
impacts of the specified activity are not likely to have more than
short-term adverse effects on any prey habitat or populations of prey
species. Further, any impacts to marine mammal habitat are not expected
to result in significant or long-term consequences for individual
marine mammals, or to contribute to adverse impacts on their
populations. Effects to habitat will not be discussed further in this
document.
Estimated Take
This section provides an estimate of the number of incidental takes
proposed for authorization through this IHA, which will inform both
NMFS' consideration of ``small numbers'' and the negligible impact
determination.
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 noise
from 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. The
proposed mitigation and monitoring measures are expected to minimize
the severity of such taking to the extent practicable. 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 mammals will be behaviorally harassed or incur some
degree of permanent hearing impairment; (2) the area or volume of water
that will be ensonified above these levels in a day; (3) the density or
occurrence of marine mammals within these ensonified areas; and, (4)
and the number of days of activities. We note that while these basic
factors can contribute to a basic calculation to provide an initial
prediction of takes, additional information that can qualitatively
inform take estimates is also sometimes available (e.g., previous
monitoring results or average group size). Below, we describe the
factors considered here in more detail and present the proposed take
estimate.
Acoustic Thresholds
Using the best available science, NMFS has developed acoustic
thresholds that identify the received level of underwater sound above
which exposed marine mammals would be reasonably expected to be
behaviorally harassed (equated to Level B harassment) or to incur PTS
of some degree (equated to Level A harassment).
Level B Harassment--Though significantly driven by received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source (e.g., frequency, predictability, duty cycle), the environment
(e.g., bathymetry), and the receiving animals (hearing, motivation,
experience, demography, behavioral context) and can be difficult to
predict (Southall et al., 2007, Ellison et al., 2012). Based on what
the available science indicates and the practical need to use a
threshold based on a factor that is both predictable and measurable for
most activities, NMFS uses a generalized acoustic threshold based on
received level to estimate the onset of behavioral harassment. NMFS
predicts that marine mammals are likely to be behaviorally harassed in
a manner we consider Level B harassment when exposed to underwater
anthropogenic noise above received levels of 160 dB re 1 [mu]Pa (rms)
for impulsive and/or intermittent sources (e.g., impact pile driving)
and 120 dB rms for continuous sources (e.g., vibratory driving).
Transco's proposed activity includes the use of intermittent sources
(impact pile driving) and continuous sources (vibratory driving),
therefore use of the 120 and 160 dB re 1 [mu]Pa (rms) thresholds are
applicable.
Level A harassment--NMFS' Technical Guidance for Assessing the
Effects of Anthropogenic Sound on
[[Page 45971]]
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 components of Transco's proposed
activity that may result in the take of marine mammals include the use
of impulsive and non-impulsive sources.
These thresholds are provided in Table 4 below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS 2018 Technical Guidance, which may be accessed at:
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 218 dB; Cell 8: LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that will feed into identifying the area ensonified above the
acoustic thresholds, which include source levels and transmission loss
coefficient.
Sound Propagation--Transmission loss (TL) is the decrease in
acoustic intensity as an acoustic pressure wave propagates out from a
source. TL parameters vary with frequency, temperature, sea conditions,
current, source and receiver depth, water depth, water chemistry, and
bottom composition and topography. The general formula for underwater
TL is:
TL = B * log10(R1/R2),
Where
B = transmission loss coefficient (assumed to be 15)
R1 = the distance of the modeled SPL from the driven
pile, and
R2 = the distance from the driven pile of the initial
measurement.
This formula neglects loss due to scattering and absorption, which
is assumed to be zero here. The degree to which underwater sound
propagates away from a sound source is dependent on a variety of
factors, most notably the water bathymetry and presence or absence of
reflective or absorptive conditions including in-water structures and
sediments. Spherical spreading occurs in a perfectly unobstructed
(free-field) environment not limited by depth or water surface,
resulting in a 6 dB reduction in sound level for each doubling of
distance from the source (20*log(range)). Cylindrical spreading occurs
in an environment in which sound propagation is bounded by the water
surface and sea bottom, resulting in a reduction of 3 dB in sound level
for each doubling of distance from the source (10*log(range)). As is
common practice in coastal waters, here we assume practical spreading
loss (4.5 dB reduction in sound level for each doubling of distance).
Practical spreading is a compromise that is often used under conditions
where water depth increases as the receiver moves away from the
shoreline, resulting in an expected propagation environment that would
lie between spherical and cylindrical spreading loss conditions.
Sound Source Levels--The intensity of pile driving sounds is
greatly influenced by factors such as the type of piles, hammers, and
the physical environment in which the activity takes place. Acoustic
measurements of pile driving at the project area are not available.
Therefore, to estimate sound levels associated with the proposed
project, representative source levels for installation and removal of
each pile type and size were identified using the compendium compiled
by the California Department of Transportation (Caltrans, 2015). The
information presented in Caltrans (2015) is a compilation of SPLs
recorded during various in-water pile driving projects in California,
Oregon, Washington, and Nebraska. The compendium is a commonly used
reference document for pile driving source levels when analyzing
potential impacts on protected species, including marine mammals, from
pile driving activities.
The proposed project would include impact and vibratory
installation and vibratory removal of 0.25-m (10-in), 0.61-m (24-in),
0.86-m (34-in), 0.91-m (36-in), 0.91- to 1.2-m (36- to 48-in), and 1.5-
m (60-in)-diameter steel pipe piles. Reference source levels from
Caltrans (2015) were determined using data for piles of similar sizes,
the same pile driving method as that proposed for the project, and at
similar water depths (Table 5). While the pile sizes and water depths
chosen as proxies do not exactly match those for the proposed project,
they represent the closest matches available. It is assumed that the
source levels shown in Table 5 are the most representative for each
pile type and associated pile driving method. To be conservative, the
representative sound source levels were based on the largest pile
expected to be driven/removed at each potential in-water construction
site. For example, where Transco may use a range of pile sizes (i.e.,
0.91 to 1.2 m (36 to 48 in)), the largest potential pile size (1.2 m
(48 in)) was used in the modeling.
[[Page 45972]]
Table 5--Modeled Pile Installation and Removal Source Levels
----------------------------------------------------------------------------------------------------------------
RMS (dB) SEL
Pile diameter (in) ---------------------------------------------------------------
Impact Vibratory Impact Vibratory
----------------------------------------------------------------------------------------------------------------
Installation
----------------------------------------------------------------------------------------------------------------
10.............................................. .............. 150 .............. 150
24.............................................. .............. 160 .............. 160
34.............................................. 193 168 183 168
36.............................................. 193 168 183 168
48.............................................. .............. 170 .............. 170
60.............................................. 195 170 185 170
----------------------------------------------------------------------------------------------------------------
Removal
----------------------------------------------------------------------------------------------------------------
10.............................................. .............. 150 .............. 150
24.............................................. .............. 160 .............. 160
34.............................................. .............. 168 .............. 168
36.............................................. .............. 168 .............. 168
48.............................................. .............. 170 .............. 170
60.............................................. .............. 170 .............. 170
----------------------------------------------------------------------------------------------------------------
Since there would be many piles at each of the construction sites
within close proximately to one another, it was not practical to
estimate zones of influence (ZOIs) for each individual pile, and
results would have been nearly identical for all similarly sized piles
at each construction location. In order to simplify calculations, a
representative pile site was selected for eight separate pile locations
(Table 6) (See Figure 8 in the IHA application for the representative
locations).
Table 6--Representative Pile Sites Selected for Modeling
------------------------------------------------------------------------
Pile size
Location/mile post (MP) (inches)
------------------------------------------------------------------------
HDD Morgan Offshore (MP 12.59).......................... 24
36
48
Neptune Power Cable Crossing (MP 13.84)................. 10
MP 14.5 to MP 16.5...................................... 24
MP 28.0 to MP 29.36..................................... 34
HDD Ambrose West Side (MP 29.4)......................... 24
36
48
60
HDD Ambrose East Side (MP 30.48)........................ 24
36
48
60
MP 34.5 to MP 35.04..................................... 34
Neptune Power Cable Crossing (MP 35.04)................. 10
------------------------------------------------------------------------
For strings where only a single pile type would be installed or
removed (i.e., Neptune Power Cable Crossing MP13.84 and MP35.04, MP14.5
to MP16.5, MP28.0 to MP29.36, and MP34.5 to MP35.04), the
representative pile location was selected in the middle of the string.
For the HDD Morgan Offshore string site, the location closest to the
platform installation was selected as the representative pile location
as it represents the area with the largest pile sizes. The HDD Ambrose
West Side and HDD Ambrose East Side representative pile locations were
selected based on the entry and exit pits. The HDD Ambrose East Side is
the entry pit and the HDD Ambrose West Side is the exit pit. This would
also represent the outer limit of the HDD Ambrose string, and is
therefore the most conservative modeling option.
Distances to isopleths associated with Level A and Level B
harassment thresholds were calculated for each pile size, for vibratory
and impact installation and removal activities, at the representative
pile locations (Table 6). 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 from the proposed project the NMFS
Optional User Spreadsheet predicts the closest distance at which, if a
marine mammal remained at that distance the whole duration of the
activity, it would incur PTS. Inputs used in the Optional User
Spreadsheet, and the resulting isopleths, are reported below. The
``Impact Pile Driving'' and ``Non-Impulse-stationary-continuous'' tabs
of the Optional User Spreadsheet were used to calculate isopleth
distances to the Level A harassment thresholds for impact and vibratory
driving, respectively.
The updated acoustic thresholds for impulsive sounds (such as pile
driving) contained in the Technical Guidance (NMFS, 2018) were
presented as dual metric acoustic thresholds using both
SELcum and peak sound pressure level metrics. As dual
metrics, NMFS considers onset of PTS (Level A harassment) to have
occurred when either one of the two metrics is exceeded (i.e., metric
resulting in the largest isopleth). The SELcum metric
considers both level and duration of exposure, as well as auditory
weighting functions by marine mammal hearing group. Isopleth distances
to relevant Level A harassment thresholds were calculated, for both the
SELcum and peak sound pressure level metrics, for all pile
sizes at the representative pile driving locations as described above.
The largest modeled isopleth distance to harassment thresholds based on
the peak SPL metric was 34.1 m which was modeled based on 60 inch piles
for the high frequency functional hearing group
[[Page 45973]]
(threshold of 202 dB re 1 [micro]Pa; Table 4). Calculation of isopleth
distances to relevant Level A harassment thresholds for all pile sizes
and all marine mammal functional hearing groups resulted in greater
modeled distances associated with the SELcum metric than the
peak sound pressure level metric, thus the modeled distances associated
with the SELcum metric were carried forward in the exposure
analysis to be conservative. It should be noted that this method likely
results in a conservative estimate of Level A exposures because the
SELcum metric assumes continuous exposure to the total
duration of pile driving anticipated for a given day, which represents
an unlikely scenario given that there is likely both some temporal and
spatial separation between pile driving operations within a day (when
multiple piles are driven), and that marine mammals are mobile and
would be expected to move away from a sound source before it reached a
level that would have the potential to result in auditory injury.
Inputs to the Optional User Spreadsheet are shown in Tables 7 and 8.
The resulting isopleth distances to Level A harassment thresholds are
shown in Tables 9 and 10.
Table 7--Inputs to NMFS Optional User Spreadsheet (NMFS, 2018) to Calculate Isopleth Distances to Level A Harassment Thresholds for Vibratory Driving
and Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pile driving Pile removal
duration duration Weighting Distance of
Pile size (representative pile location) Source level (hours) within (hours) within factor Propagation source level
(RMS SPL) 24- hour 24- hour adjustment (xLogR) measurement
period period (kHz) (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
10 in. (Neptune Power Cable Crossing MP 13.84).......... 150 1.0 1.0 2.5 15 10
10 in. (Neptune Power Cable Crossing MP 35.04).......... 150 0.5 0.5 2.5 15 10
24 in. (Ambrose East MP 30.48).......................... 160 1.25 5.5 2.5 15 10
24 in. (Ambrose West MP 29.4)........................... 160 1.5 0.5 2.5 15 10
24 in. (Morgan Offshore MP 12.59)....................... 160 1.0 0.3 2.5 15 10
24 in. (MP 14.5)........................................ 160 1.25 2.75 2.5 15 10
36 in. (Morgan Offshore MP 12.59)....................... 168 1.0 4 2.5 15 10
36 in. (Ambrose East MP 30.48).......................... 168 0.75 0.75 2.5 15 10
36 in. (Ambrose West MP 29.4)........................... 168 0.5 0.75 2.5 15 10
48 in. (Ambrose East MP 30.48).......................... 170 2.0 2.0 2.5 15 10
48 in. (Ambrose West MP 29.4)........................... 170 1.0 2.0 2.5 15 10
48 in. (Morgan Offshore MP 12.59)....................... 170 1.0 0.75 2.5 15 10
60 in. (Ambrose East MP 30.48).......................... 170 0.25 0.25 2.5 15 10
60 in. (Ambrose West MP 29.4)........................... 170 0.5 4.0 2.5 15 10
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Tab A (``Non Impulsive Static Continuous'') in the NMFS Optional User Spreadsheet (NMFS, 2018) was used for all calculations for vibratory
installation of piles.
Table 8--Inputs to NMFS Optional User Spreadsheet (NMFS, 2018) To Calculate Isopleth Distances to Level A Harassment Thresholds for Impact Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
Weighting Distance of
Source level Number of Number of factor Propagation source level
Pile size (representative pile location) (RMS SPL) strikes per piles per day adjustment (xLogR) measurement
pile (kHz) (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
36 in. (Morgan Offshore MP 12.59)....................... 183 2,500 * 2/4 2 15 10
60 in. (Ambrose West.................................... 185 3,382 2 2 15 10
--------------------------------------------------------------------------------------------------------------------------------------------------------
* The number of piles driven per day will vary based on the construction schedule, thus both scenarios (i.e., 2 and 4 piles driven per day) were
modeled.
Note: Tab E1 (``Impact Pile Driving'') in the NMFS Optional User Spreadsheet (NMFS, 2018) was used for all calculations for impact pile driving.
NMFS has established Level B harassment thresholds of 160 dB
re1[mu]Pa (rms) for impulsive sounds (e.g., impact pile driving) and
120 dB re1[mu]Pa (rms) for non-impulsive sounds (e.g., vibratory
driving and removal). Based on the predicted source levels associated
with various pile sizes (Table 5) the distances from the pile driving/
removal equipment to the Level B harassment thresholds were calculated,
using the distance to the 160 dB threshold for the diesel impact hammer
and the distance to the 120 dB threshold for the vibratory device, at
the representative pile locations (Table 6). It should be noted that
while sound levels associated with the Level B harassment threshold for
vibratory driving/removal were estimated to propagate as far as 21,544
m (13 mi) from pile installation and removal activities based on
modeling, it is likely that the noise produced from vibratory
activities associated with the project would be masked by background
noise before reaching this distance, as the Port of New York and New
Jersey, which represents the busiest port on the east coast of the
United States and the third busiest port in the United States, is
located near the project area and sounds from the port and from vessel
traffic propagate throughout the project area. However, take estimates
conservatively assume propagation of project-related noise to the full
extent of the modeled isopleth distance to the Level B harassment
threshold. The modeled distances to isopleths associated with Level B
harassment thresholds for impact and vibratory driving are shown in
Tables 9 and 10.
[[Page 45974]]
Table 9--Modeled Isopleth Distances to Level A and Level B Harassment Thresholds for Impact and Vibratory Pile
Installation
----------------------------------------------------------------------------------------------------------------
Low- Mid- High-
frequency frequency frequency Phocid Cetaceans
cetaceans cetaceans cetaceans seals and phocids
----------------------------------------------------------------------------------------------------------------
Impulsive...................................... 183 dB 185 dB 155 dB 185 dB 160 dB
Non-Impulsive.................................. 199 dB 198 dB 173 dB 201 dB 120 dB
----------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Location/mile post Pile size Hammer Distance to Level A harassment threshold (m) * Distance to
(MP) (inches) type........................ Level B
harassment
threshold
(m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
HDD Morgan Offshore (MP 12.59)........... 24 Vibratory................... 5.9 0.5 8.7 3.6 4,641.6
36 Vibratory................... 20.0 1.8 29.6 12.2 15,848.9
Impact...................... 4,635.2 164.9 5,521.3 2,480.6 1,584.9
48 Vibratory................... 27.2 2.4 40.2 16.5 21,544.3
Neptune Power Cable Crossing (MP 13.84).. 10 Vibratory................... 1.3 0.1 1.9 0.8 1,000.0
MP 14.5 to MP 16.5....................... 24 Vibratory................... 6.8 0.6 10.1 4.1 4,641.6
MP 28.0 to MP 29.36...................... 34 Vibratory................... 20.0 1.8 29.6 12.2 15,848.9
HDD Ambrose West Side (MP 29.4).......... 24 Vibratory................... 7.7 0.7 11.3 4.7 4,641.6
36 Vibratory................... 12.6 1.1 18.6 7.7 15,848.9
48 Vibratory................... 27.2 2.4 40.2 16.5 21,544.3
60 Vibratory................... 17.1 1.5 25.3 10.4 21,544.3
Impact...................... 4,855.2 172.7 5,783.3 2,598.3 2,154.4
HDD Ambrose East Side (MP 30.48)......... 24 Vibratory................... 6.8 0.6 10.1 4.1 4,641.6
36 Vibratory................... 16.5 1.5 24.4 10.0 15,848.9
48 Vibratory................... 43.2 3.8 63.8 26.2 21,544.3
60 Vibratory................... 10.8 1.0 16.0 6.6 21,544.3
MP 34.5 to MP 35.04...................... 34 Vibratory................... 12.6 1.1 18.6 7.7 15,848.9
Impact...................... 2,920.0 103.9 3,478.2 1,562.7 1,584.9
Neptune Power Cable Crossing (MP 35.04).. 10 Vibratory................... 0.8 0.1 1.2 0.5 1,000.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
* All distances shown are based on the SELcum metric. Distances to the peak SPL metric for impact driving were smaller than those for the SELcum metric
for all pile sizes and scenarios.
Table 10--Modeled Isopleth Distances to Level A and Level B Harassment Thresholds for Vibratory Pile Removal
----------------------------------------------------------------------------------------------------------------
Low- Mid- High-
frequency frequency frequency Phocid Cetaceans
cetaceans cetaceans cetaceans seals and phocids
----------------------------------------------------------------------------------------------------------------
Non-Impulsive.................................. 199 dB 198 dB 173 dB 201 dB 120 dB
----------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Location/mile post Pile size Hammer Distance to Level A harassment threshold (m) Distance to
(MP) (inches) type........................ Level B
harassment
threshold
(m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
HDD Morgan Offshore (MP 12.59)........... 24 Vibratory................... 2.6 0.2 3.9 1.6 4,641.6
36 Vibratory................... 50.4 4.5 74.5 30.6 15,848.9
48 Vibratory................... 22.4 2.0 33.2 13.6 21,544.3
Neptune Power Cable Crossing (MP 13.84).. 10 Vibratory................... 1.3 0.1 1.9 0.8 1,000.0
MP 14.5 to MP 16.5....................... 24 Vibratory................... 11.5 1.0 17.0 7.0 4,641.6
MP 28.0 to MP 29.36...................... 34 Vibratory................... 41.6 3.7 61.5 25.3 15,848.9
HDD Ambrose West Side (MP 29.4).......... 24 Vibratory................... 3.7 0.3 5.5 2.2 4,641.6
36 Vibratory................... 16.5 1.5 24.4 10.0 15,848.9
48 Vibratory................... 43.2 3.8 63.8 26.2 21,544.3
60 Vibratory................... 68.5 6.1 101.3 41.6 21,544.3
HDD Ambrose East Side (MP 30.48)......... 24 Vibratory................... 18.3 1.6 27.0 11.1 4,641.6
36 Vibratory................... 16.5 1.5 24.4 10.0 15,848.9
48 Vibratory................... 43.2 3.8 63.8 26.2 21,544.3
60 Vibratory................... 10.8 1.0 16.0 6.6 21,544.3
MP 34.5 to MP 35.04...................... 34 Vibratory................... 12.6 1.1 18.6 7.7 15,848.9
Neptune Power Cable Crossing (MP 35.04).. 10 Vibratory................... 0.8 0.1 1.2 0.5 1,000.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 45975]]
Marine Mammal Occurrence
In this section we provide the information about the presence,
density, or group dynamics of marine mammals that will inform the take
calculations.
There are no marine mammal density estimates for Raritan Bay. The
best available information regarding marine mammal densities in the
project area is provided by habitat-based density models produced by
the Duke University Marine Geospatial Ecology Laboratory (Roberts et
al., 2016, 2017, 2018). These density models were originally developed
for all cetacean taxa in the U.S. Atlantic (Roberts et al., 2016); more
information, including the model results and supplementary information
for each model, is available at seamap.env.duke.edu/models/Duke-EC-GOM-2015/. In subsequent years, certain models have been updated on the
basis of additional data as well as certain methodological
improvements. Although these updated models (and a newly developed seal
density model) are not currently publicly available, our evaluation of
the changes leads to a conclusion that these represent the best
scientific evidence available. Marine mammal density estimates in the
project area (animals/km\2\) were obtained using these model results
(Roberts et al., 2016, 2017, 2018). As noted, the updated models
incorporate additional sighting data, including sightings from the NOAA
Atlantic Marine Assessment Program for Protected Species (AMAPPS)
surveys from 2010-2014 (NEFSC & SEFSC, 2011b, 2012, 2014a, 2014b, 2015,
2016). For each cetacean species, density data for summer (June-August)
and fall (September, October, November) were used to generate source
grids by averaging monthly densities (see Figure 15 in the IHA
application for an example of one such source grid). Since the source
density grids do not extend to Raritan Bay, the grids were extrapolated
to cover the bay and values were pulled from the nearest grid cell to
assign density values to those empty cells in order to approximate
densities in Raritan Bay (see Figure 16 in the IHA application). The
resulting density grid was used to calculate take estimates of marine
mammals for pile installation and removal activities. It should be
noted that this approach likely results in conservative estimates of
cetacean density for the project area, as cetacean densities in Raritan
Bay are expected to be lower than the densities in the areas of the
Atlantic Ocean from which the densities were extrapolated (with the
exception of humpback whales, as described below).
For harbor seals and gray seals, densities were first obtained from
Roberts et al. (2018), as described above for cetacean densities.
However, because the pinniped data used in the Roberts et al. (2018)
density models were derived from offshore aerial and vessel surveys,
the models did not accurately represent the densities of pinnipeds that
would be expected in Raritan Bay, as they underestimate densities that
would be expected closer to shore which would be higher than those
offshore due to closer proximity to haulouts. Thus, the extrapolation
of pinniped densities from Roberts et al. (2018) to Raritan Bay
resulted in exposure estimates that were not consistent with
expectations of actual pinniped densities based on the number of
opportunistic sightings reported in the project area. There have been
no systematic studies focusing on seal populations within Raritan Bay,
Lower New York Bay, or Sandy Hook Bay. Therefore, pinniped densities
were estimated using systematic data collected by Coastal Research and
Education Society of Long Island, Inc. (CRESLI) from November 18, 2018,
to April 16, 2019, at Cupsogue Beach Park in Westhampton Beach, NY
(CRESLI, 2019).
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate. The following steps
were performed to estimate the potential numbers of marine mammal
exposures above Level A and Level B harassment thresholds as a result
of the proposed activity:
1. Distances to isopleths corresponding to Level A and Level B
harassment thresholds were calculated for each pile size for vibratory
and impact installation and removal activities at the representative
pile locations within the Project area, as described above.
2. GIS analysis was then used, incorporating these distance values
and a viewshed analysis (described below), to calculate resulting ZOIs.
3. Species density estimations were incorporated in the GIS
analysis to determine estimated number of daily exposures.
4. Daily exposure estimates were multiplied by the duration (days)
of the corresponding in-water construction activity (based on pile size
and location).
As described above, the distances to isopleths associated with
Level A and Level B harassment thresholds were calculated for each pile
size for vibratory and impact installation and removal activities
(Tables 9 and 10). These distances to relevant thresholds were then
incorporated into a GIS analysis to analyze the relevant ZOIs within
which take of marine mammals would be expected to occur. Given that the
proposed activity would occur in a semi-enclosed bay, the modeled
distances to thresholds would in some cases be truncated by land (i.e.,
the sounds from the proposed activity would not propagate to the full
modeled isopleth distances because of the presence of land, which in
some cases is closer to the pile driving/removal location than the
total distances). A viewshed analysis is a standard technique used in
GIS to determine whether an area is visible from a specific location
(Kim et al., 2004). The analysis uses an elevation value of two points
with direct line of sight to determine the likelihood of seeing the
elevated point from the ground. Incorporating the viewshed analysis
allowed GIS modeling of sound propagation to replicate how sound waves
traveling through the water are truncated when they encounter land. GIS
modeling used an artificial elevation model setting the water to zero
(ground) and any land mass to 100 (elevated point) and focusing only on
areas within the Project area where sound would propagate. Any land
within direct `line of sight' to the sound source would prevent the
sound from propagating farther. This method was applied to each of the
eight representative pile locations. This simple model does not account
for diffusion, which would be minimal with large landmasses; therefore
in the model no sound bends around landmasses. See Figure 9 in the IHA
application for an example of applying the viewshed analysis to a
single representative pile location (HDD Morgan Offshore).
A custom Python script was developed to calculate potential
cetacean takes due to pile installation and removal activities. The
script overlays the species-specific Level A and Level B harassment
ZOIs (each clipped by the viewshed) for each pile size and type at each
of the representative pile locations (Table 6), over the density grid
cells. The script then multiplies the total density value by the area
of the ZOI, resulting in initial take estimate outputs. The following
formulas were implemented by the script for each species at each
representative pile location:
Initial Level A take estimate = ZOI * d
Initial Level B take estimate = ZOI * d
Where:
[[Page 45976]]
ZOI = the ensonified area at or above the species-specific acoustic
threshold, clipped by the viewshed.
d = density estimate for each species within the ZOI.
The initial take estimates were then multiplied by the duration
(days) of the corresponding in-water construction activity (based on
pile size and location). The following formulas demonstrate this
method:
Level A take estimate = initial take estimate * X days of activity
Level B take estimate = initial take estimate * X days of activity
Where:
X days of activity = number of days for which the corresponding in-
water construction activity occurs.
These numbers were then totaled to provide estimates of the numbers
of take by Level A and Level B harassment for each species. The
exposure numbers were rounded to the nearest whole individual. As the
construction schedule has not yet been finalized, the take calculations
described above were performed for two scenarios: (1) All construction
activities occurring during summer 2020, and (2) installation occurring
during the summer and removal in fall of 2020. To be conservative, the
higher take estimates calculated between the two scenarios were then
carried forward in the analysis.
Note that for bottlenose dolphins, the density data presented by
Roberts et al. (2016) does not differentiate between bottlenose dolphin
stocks. Thus, the take estimate for bottlenose dolphins calculated by
the method described above resulted in an estimate of the total of
bottlenose dolphins expected to be taken, from all stocks (for a total
of 6,331 takes by Level B harassment). However, as described above,
both the Western North Atlantic Northern Migratory Coastal stock and
the Western North Atlantic Offshore stock have the potential to occur
in the project area. As the project area represents the extreme
northern extent of the known range of the Western North Atlantic
Northern Migratory Coastal stock, and as dolphins from the Western
North Atlantic Northern Migratory Coastal stock have never been
documented in Raritan Bay, we assume that 25 percent of bottlenose
dolphins taken would be from the North Atlantic Northern Migratory
Coastal stock and the remaining 75 percent of bottlenose dolphins taken
will be from the Western North Atlantic Offshore stock. Thus, we
allocated 75 percent of the total proposed authorized bottlenose
dolphin takes to the Western North Atlantic Offshore stock (total 4,748
takes by Level B harassment), and 25 percent to the Western North
Atlantic Northern Migratory Coastal stock (total 1,583 takes by Level B
harassment) (Table 11).
For humpback whales and harbor, gray and harp seals, the methods
used to estimate take were slightly different than the methodology
described above. For humpback whales, the steps above resulted in zero
exposures above the Level B harassment threshold. However, there are
confirmed anecdotal sightings of humpback whales within or near the
project area, indicating that potential exposures above the Level B
harassment threshold may occur and therefore should be accounted for.
As the exposure estimate method described above resulted in zero
exposures, other methods for calculating take by Level B harassment
were applied. Brown et al. (2018) reported 617 sightings of humpback
whales within the New York Bight from 2011 to 2017. The total number of
sightings was divided by the total number of years of surveys (n=6),
and this number was then divided by 12 months, to estimate a mean
number of whales per month. This number was then multiplied by a
conservative number of months of pile driving and removal activities
(n=4) to estimate the number of humpback whales that may be taken Level
B harassment (Table 11).
As described above, local survey data represents the best available
information on abundance estimates for pinnipeds in the project area.
Estimates of take by Level B harassment for gray and harbor seals were
calculated using systematic data collected by CRESLI from November 18,
2018, to April 16, 2019, where a total of 2,689 harbor seals were
sighted at Cupsogue Beach Park. The total number of sightings was
divided by the total number of survey months (n=5) to get a mean number
of individual seals per month. This number was then multiplied by a
conservative number of potential months of pile driving and removal
activities (n=4) to estimate a total number of seals (2,151) expected
to be taken over the duration of the proposed project. To estimate the
potential number of gray seals and harbor seals that may be taken, the
ratio of harbor seals (64 percent) versus gray seals (36 percent) was
calculated based on available density data. The data presented by
Roberts et al. (2018 does not differentiate by seal species. Thus the
best available density information on the ratio of gray to harbor seals
comes from the U.S. Navy's OPAREA Density Estimates (Halpin et al.
2009; Navy 2007, 2012). The ratio of gray to harbor seals in the OPAREA
Density Estimates was therefore applied to the total number of seals
estimated to be taken (n=2,151), to estimate the total number of gray
and harbor seals expected to be taken during the duration of the
proposed project. Based on this approach, we propose to authorize the
incidental take of 1,377 harbor seals (2,151 * 0.64) and 774 gray seals
(2,151 * 0.36).
To calculate estimates of take by Level A harassment for gray and
harbor seals, a ratio of take by Level A harassment relative to take by
Level B harassment was calculated using the NODES data. These estimates
accounted for the spatial extent of potential exposure to noise that
could result in Level A and B harassment since they were based on the
ensonifed areas multiplied by the NODES densities. Therefore, an
estimation of the potential exposure of pinnipeds to Level A harassment
as a proportion of potential exposure of pinnipeds to Level B
harassment was used to calculate a reasonable estimate of Level A
harassment takes using the Level B harassment estimates. This ratio was
0.009 for harbor seals and 0.008 for gray seals; therefore, we propose
to authorize the take by Level A harassment of 12 harbor seals (1,377 *
0.009) and 6 gray seals (774 * 0.008).
Due to lack of data and their rare occurrence in the Mid-Atlantic
region, no densities for harp seals are available. However, harp seals
have been documented along the southern coast of Long Island during the
winter, and a recent pinniped UME has resulted in increased strandings
of harp seals on the Atlantic coast. Because so few harp seals have
been documented in the region of the project area, we estimate that up
to four harp seals (the total number opportunistically observed at
Cupsogue Beach (CRESLI, 2008) could enter the Level B harassment zone
and be taken by Level B harassment. Take numbers proposed for
authorization are shown in Table 11.
[[Page 45977]]
Table 11--Total Numbers of Potential Incidental Takes of Marine Mammals Proposed for Authorization and Proposed
Takes as a Percentage of Population
----------------------------------------------------------------------------------------------------------------
Total takes
Takes by Level Takes by Level proposed for
A harassment B harassment Total takes authorization
Species proposed for proposed for proposed for as a
authorization authorization authorization percentage of
stock taken *
----------------------------------------------------------------------------------------------------------------
Fin whale....................................... 0 5 5 0.1
Humpback Whale.................................. 0 34 34 2.1
Minke Whale..................................... 0 1 1 0.0
North Atlantic Right Whale...................... 0 2 2 0.5
Bottlenose Dolphin--Western North Atlantic 0 1,583 1,583 23.8
Northern Migratory Coastal stock...............
Bottlenose Dolphin--Western North Atlantic 0 4,748 4,748 6.1
Offshore stock.................................
Common Dolphin.................................. 0 95 95 0.1
Harbor porpoise................................. 0 11 11 0.0
Gray seal....................................... 6 774 780 2.9
Harbor seal..................................... 12 1,377 1,389 1.8
Harp seal....................................... 0 4 4 0.0
----------------------------------------------------------------------------------------------------------------
* Calculations of percentage of stock taken are based on the best available abundance estimate as shown in Table
2. For North Atlantic right whales the best available abundance estimate is derived from the 2018 North
Atlantic Right Whale Consortium 2018 Annual Report Card (Pettis et al., 2018). For the pinniped species the
best available abundance estimates are derived from the most recent NMFS Stock Assessment Reports. For all
other species, the best available abundance estimates are derived from Roberts et al. (2016, 2017, 2018).
The take numbers we propose for authorization are considered
conservative for the following reasons:
Density estimates assume are largely derived from adjacent
grid-cells that likely overestimate density in the vicinity of the
project area.
Proposed Level A harassment take numbers do not account
for the likelihood that marine mammals will avoid a stimulus when
possible before that stimulus reaches a level that would have the
potential to result in injury; and
Proposed Level A harassment take numbers do not account
for the effectiveness of proposed mitigation and monitoring measures in
reducing the number of takes.
Proposed Mitigation
In order to issue an IHA under Section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to such
activity, and other means of effecting the least practicable impact on
such species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of such species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for 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 and impact on
operations.
The mitigation strategies described below are consistent with those
required and successfully implemented under previous incidental take
authorizations issued in association with in-water construction
activities. Modeling was performed to estimate zones of influence (ZOI;
see ``Estimated Take''); these ZOI values were used to inform
mitigation measures for pile driving activities to minimize Level A
harassment and Level B harassment to the extent possible, while
providing estimates of the areas within which Level B harassment might
occur.
In addition to the specific measures described later in this
section, Transco would conduct briefings for construction supervisors
and crews, the marine mammal monitoring teams, and Transco 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.
Pre-Clearance Zones
Transco would use Protected Species Observers (PSOs) to establish
pre-clearance zones around the pile driving equipment to ensure these
zones are clear of marine mammals prior to the start of pile driving.
The purpose of ``clearance'' of a particular zone is to prevent
potential instances of auditory injury and potential instances of more
severe behavioral disturbance as a result of exposure to pile driving
noise (serious injury or death are unlikely outcomes even in the
absence of mitigation measures) by delaying the activity before it
begins if marine mammals are detected within certain pre-defined
distances of the pile driving equipment. The primary goal in this case
is to prevent auditory injury (Level A harassment), and the proposed
pre-clearance zones are larger than the modeled distances to the
isopleths corresponding to Level A harassment (based on peak SPL) for
all marine mammal functional hearing groups. These zones vary depending
on species and are shown in Table 12. All
[[Page 45978]]
distances to pre-clearance zones are the radius from the center of the
pile being driven.
Table 12--Proposed Pre-Clearance Zones During Transco Pile Driving and
Removal Activities
------------------------------------------------------------------------
Species Clearance zone
------------------------------------------------------------------------
North Atlantic right whale................ Any distance.
Fin and humpback whale.................... 1,000 m.
All other marine mammal species........... 100 m.
------------------------------------------------------------------------
If a marine mammal is observed approaching or entering the relevant
pre-clearance zones prior to the start of pile driving operations, pile
driving activity would be delayed until either the marine mammal has
voluntarily left the respective clearance zone and been visually
confirmed beyond that zone, or, 30 minutes have elapsed without re-
detection of the animal.
Prior to the start of pile driving activity, the pre-clearance
zones will be monitored for 30 minutes to ensure that they are clear of
the relevant species of marine mammals. Pile driving would only
commence once PSOs have declared the respective pre-clearance zones
clear of marine mammals. Marine mammals observed within a pre-clearance
zone will be allowed to remain in the pre-clearance zone (i.e., must
leave of their own volition), and their behavior will be monitored and
documented. The pre-clearance zones (to a distance of 1,000 m) may only
be declared clear, and pile driving started, when the entire pre-
clearance zones are visible (i.e., when not obscured by dark, rain,
fog, etc.) for a full 30 minutes prior to pile driving.
Soft Start
The use of a soft start procedure is believed to provide additional
protection to marine mammals by warning marine mammals or providing
them with a chance to leave the area prior to the hammer operating at
full capacity, and typically involves a requirement to initiate sound
from the hammer at reduced energy followed by a waiting period. Transco
will utilize soft start techniques for impact pile driving by
performing an initial set of three strikes from the impact hammer at a
reduced energy level followed by a thirty second waiting period. The
soft start process would be conducted a total of three times prior to
driving each pile (e.g., three strikes followed by a thirty second
delay, then three additional single strikes followed by a thirty second
delay, then a final set of three strikes followed by an additional
thirty second delay). Soft start would be required at the beginning of
each day's impact pile driving work and at any time following a
cessation of impact pile driving of thirty minutes or longer.
Shutdown
The purpose of a shutdown is to prevent some undesirable outcome,
such as auditory injury or behavioral disturbance of sensitive species,
by halting the activity. If a marine mammal is observed entering or
within the shutdown zones after pile driving has begun, the PSO will
request a temporary cessation of pile driving. Transco has proposed
that, when called for by a PSO, shutdown of pile driving would be
implemented when feasible. However, if a shutdown is called for before
a pile has been driven to a sufficient depth to allow for pile
stability, then for safety reasons the pile would need to be driven to
a sufficient depth to allow for stability and a shutdown would not be
feasible until after that depth was reached. We therefore propose that
shutdown would be implemented when feasible. If shutdown is called for
by a PSO, and Transco determines a shutdown to be technically feasible,
pile driving would be halted immediately. After shutdown, pile driving
may be initiated once all clearance zones are clear of marine mammals
for the minimum species-specific time periods, or, if required to
maintain installation feasibility. For North Atlantic right whales,
shutdown would occur when a right whale is observed by PSOs at any
distance, and a shutdown zone of 85 m (279 ft) would be implemented for
all other species (Table 13). The 500 m zone is proposed as a
protective measure to avoid takes by Level A harassment, and
potentially some takes by Level B harassment, of North Atlantic right
whales. The 85 m zone was calculated based on the distance to the Level
A harassment threshold based on the peak sound pressure metric (202 dB
re 1[micro] Pa) for a 66-inch steel pile, plus an additional 50 m (164-
ft) buffer.
Table 13--Proposed Shutdown Zones During Transco Pile Driving and
Removal Activities
------------------------------------------------------------------------
Species Shutdown zone
------------------------------------------------------------------------
North Atlantic right whale................ Any distance.
All other marine mammal species........... 85 m.
------------------------------------------------------------------------
Visibility Requirements
All in-water construction and removal activities would be conducted
during daylight hours, no earlier than 30 minutes after sunrise and no
later than 30 minutes before sunset. Pile driving would not be
initiated at night, or, when the full extent of all relevant clearance
zones cannot be confirmed to be clear of marine mammals, as determined
by the lead PSO on duty. The clearance zones may only be declared
clear, and pile driving started, when the full extent of all clearance
zones are visible (i.e., when not obscured by dark, rain, fog, etc.)
for a full 30 minutes prior to pile driving.
Monitoring Protocols
Monitoring would be conducted before, during, and after pile
driving activities. In addition, observers will record all incidents of
marine mammal occurrence, regardless of distance from the construction
activity, and monitors will document any behavioral reactions in
concert with distance from piles being driven. Observations made
outside the shutdown zones will not result in delay of pile driving;
that pile segment may be completed without cessation, unless the marine
mammal approaches or enters the shutdown zone, at which point pile
driving activities would be halted when practicable, as described
above. Pile driving activities include the time to install a single
pile or series of piles, as long as the time elapsed between uses of
the pile driving equipment is no more than 30 minutes.
The following additional measures apply to visual monitoring:
(1) A minimum of two PSOs would be on duty at all times during pile
driving and removal activity;
(2) Monitoring would be conducted by qualified, trained PSOs. One
PSO would be stationed on the construction barge and one on an escort
boat, during impact and vibratory pile installation and removal. The
escort boat location would shift depending on work location, but will
be a minimum of 100 to 200 m (328 to 656 ft) from the pile-driving
location, depending on the site and the ensonification area associated
with that specific pile-driving scenario;
(3) PSOs may not exceed four consecutive watch hours; must have a
minimum two-hour break between watches; and may not exceed a combined
watch schedule of more than 12 hours in a 24-hour period;
(4) Monitoring will be conducted from 30 minutes prior to
commencement of pile driving, throughout the time required to drive a
pile, and for 30 minutes following the conclusion of pile driving;
[[Page 45979]]
(5) PSOs will have no other construction-related tasks while
conducting monitoring; and
(6) PSOs would have the following minimum qualifications:
Visual acuity in both eyes (correction is permissible)
sufficient for discernment of moving targets at the water's surface
with ability to estimate target size and distance; use of binoculars
may be necessary to correctly identify the target;
Ability to conduct field observations and collect data
according to assigned protocols;
Experience or training in the field identification of
marine mammals, including the identification of behaviors;
Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
Writing skills sufficient to document observations
including, but not limited to: The number and species of marine mammals
observed; dates and times when in-water construction activities were
conducted; dates and times when in-water construction activities were
suspended to avoid potential incidental injury of marine mammals from
construction noise within a defined shutdown zone; and marine mammal
behavior; and
Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary.
PSOs employed by Transco in satisfaction of the mitigation and
monitoring requirements described herein must meet the following
additional requirements:
Independent observers (i.e., not construction personnel)
are required;
At least one observer must have prior experience working
as an observer;
Other observers may substitute education (degree in
biological science or related field) or training for experience;
One observer will be designated as lead observer or
monitoring coordinator. The lead observer must have prior experience
working as an observer; and
NMFS will require submission and approval of observer CVs.
Vessel Strike Avoidance
Vessel strike avoidance measures will include, but are not limited
to, the following, except under circumstances when complying with these
measures would put the safety of the vessel or crew at risk:
All vessel operators and crew must maintain vigilant watch
for cetaceans and pinnipeds, and slow down or stop their vessel to
avoid striking these protected species;
All vessels must travel at 10 knots (18.5 km/hr) or less
within any designated Dynamic Management Area (DMA) for North Atlantic
right whales;
All vessels greater than or equal to 65 ft (19.8 m) in
overall length will comply with 10 knot (18.5 km/hr) or less speed
restriction in any Seasonal Management Area (SMA) for North Atlantic
right whales per the NOAA ship strike reduction rule (73 FR 60173;
October 10, 2008);
All vessel operators will reduce vessel speed to 10 knots
(18.5 km/hr) or less when any large whale, any mother/calf pairs, pods,
or large assemblages of non-delphinoid cetaceans are observed near
(within 100 m (330 ft)) an underway vessel;
All survey vessels will maintain a separation distance of
500 m (1640 ft) or greater from any sighted North Atlantic right whale;
If underway, vessels must steer a course away from any
sighted North Atlantic right whale at 10 knots (18.5 km/hr) or less
until the 500 m (1640 ft) minimum separation distance has been
established. If a North Atlantic right whale is sighted in a vessel's
path, or within 500 m (330 ft) to an underway vessel, the underway
vessel must reduce speed and shift the engine to neutral. Engines will
not be engaged until the right whale has moved outside of the vessel's
path and beyond 500 m. If stationary, the vessel must not engage
engines until the North Atlantic right whale has moved beyond 500 m;
All vessels will maintain a separation distance of 100 m
(330 ft) or greater from any sighted non-delphinoid cetacean. If
sighted, the vessel underway must reduce speed and shift the engine to
neutral, and must not engage the engines until the non-delphinoid
cetacean has moved outside of the vessel's path and beyond 100 m. If a
vessel is stationary, the vessel will not engage engines until the non-
delphinoid cetacean has moved out of the vessel's path and beyond 100
m;
All vessels will maintain a separation distance of 50 m
(164 ft) or greater from any sighted delphinoid cetacean, with the
exception of delphinoid cetaceans that voluntarily approach the vessel
(i.e., bow ride). Any vessel underway must remain parallel to a sighted
delphinoid cetacean's course whenever possible, and avoid excessive
speed or abrupt changes in direction. Any vessel underway must reduce
vessel speed to 10 knots (18.5 km/hr) or less when pods (including
mother/calf pairs) or large assemblages of delphinoid cetaceans are
observed. Vessels may not adjust course and speed until the delphinoid
cetaceans have moved beyond 50 m and/or the abeam of the underway
vessel;
All vessels will maintain a separation distance of 50 m
(164 ft) or greater from any sighted pinniped; and
All vessels underway will not divert or alter course in
order to approach any whale, delphinoid cetacean, or pinniped. Any
vessel underway will avoid excessive speed or abrupt changes in
direction to avoid injury to the sighted cetacean or pinniped.
Transco will ensure that vessel operators and crew maintain a
vigilant watch for marine mammals by slowing down or stopping the
vessel to avoid striking marine mammals. Project-specific training will
be conducted for all vessel crew prior to the start of the construction
activities. Confirmation of the training and understanding of the
requirements will be documented on a training course log sheet.
We have carefully evaluated Transco's proposed mitigation measures
and considered a range of other measures in the context of ensuring
that we prescribed the means of effecting the least practicable adverse
impact on the affected marine mammal species and stocks and their
habitat. Based on our evaluation of these measures, we have
preliminarily determined that the proposed mitigation measures provide
the means of effecting the least practicable adverse impact on marine
mammal 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
[[Page 45980]]
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); and
Mitigation and monitoring effectiveness.
Visual Marine Mammal Observations
Transco will collect sighting data and behavioral responses to pile
driving activity for marine mammal species observed in the region of
activity during the period of activity. All observers will be trained
in marine mammal identification and behaviors and are required to have
no other construction-related tasks while conducting monitoring. PSOs
would monitor all clearance zones at all times. PSOs would also monitor
Level B harassment zones and would document any marine mammals observed
within these zones, to the extent practicable (noting that some
distances to these zones are too large to fully observe). Transco would
conduct monitoring before, during, and after pile driving and removal,
with observers located at the best practicable vantage points.
Transco would implement the following monitoring procedures:
A minimum of two PSOs will maintain watch at all times
when pile driving or removal is underway;
PSOs would be located at the best possible vantage
point(s) to ensure that they are able to observe the entire clearance
zones and as much of the Level B harassment zone as possible;
During all observation periods, PSOs will use binoculars
and the naked eye to search continuously for marine mammals;
If the clearance zones are obscured by fog or poor
lighting conditions, pile driving will not be initiated until clearance
zones are fully visible. Should such conditions arise while impact
driving is underway, the activity would be halted when practicable, as
described above; and
The clearance zones will be monitored for the presence of
marine mammals before, during, and after all pile driving activity.
Individuals implementing the monitoring protocol will assess its
effectiveness using an adaptive approach. PSOs will use their best
professional judgment throughout implementation and seek improvements
to these methods when deemed appropriate. Any modifications to the
protocol will be coordinated between NMFS and Transco.
Data Collection
We require that observers use standardized data forms. Among other
pieces of information, Transco will record detailed information about
any implementation of delays or shutdowns, including the distance of
animals to the pile and a description of specific actions that ensued
and resulting behavior of the animal, if any. We require that, at a
minimum, the following information be collected on the sighting forms:
Date and time that monitored activity begins or ends;
Construction activities occurring during each observation
period;
Weather parameters (e.g., wind speed, percent cloud cover,
visibility);
Water conditions (e.g., sea state, tide state);
Species, numbers, and, if possible, sex and age class of
marine mammals;
Description of any observable marine mammal behavior
patterns, including bearing and direction of travel and distance from
pile driving activity;
Distance from pile driving activities to marine mammals
and distance from the marine mammals to the observation point;
Type of construction activity (e.g., impact or vibratory
driving/removal) when marine mammals are observed.
Description of implementation of mitigation measures
(e.g., delay or shutdown).
Locations of all marine mammal observations; and
Other human activity in the area.
Transco would note behavioral observations, to the extent
practicable, if an animal has remained in the area during construction
activities.
Reporting
A draft report would be submitted to NMFS within 90 days of the
completion of monitoring for each installation's in-water work window.
The report would include marine mammal observations pre-activity,
during-activity, and post-activity during pile driving days, and would
also provide descriptions of any behavioral responses to construction
activities by marine mammals. The report would detail the monitoring
protocol, summarize the data recorded during monitoring including an
estimate of the number of marine mammals that may have been harassed
during the period of the report, and describe any mitigation actions
taken (i.e., delays or shutdowns due to detections of marine mammals,
and documentation of when shutdowns were called for but not implemented
and why). A final report must be submitted within 30 days following
resolution of comments on the draft report.
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
[[Page 45981]]
sources of human-caused mortality, or ambient noise levels).
Pile driving and removal activities associated with the proposed
project, as described previously, have the potential to disturb or
temporarily displace marine mammals. Specifically, the specified
activities may result in take, in the form of Level A harassment
(potential injury) or Level B harassment (potential behavioral
disturbance) from underwater sounds generated from pile driving and
removal. Potential takes could occur if individual marine mammals are
present in the ensonified zone when pile driving and removal is
occurring. To avoid repetition, the our analyses apply to all the
species listed in Table 1, given that the anticipated effects of the
proposed project on different marine mammal species and stocks are
expected to be similar in nature.
Impact pile driving has source characteristics (short, sharp pulses
with higher peak levels and sharper rise time to reach those peaks)
that are potentially injurious or more likely to produce severe
behavioral reactions. However, modeling indicates there is limited
potential for injury even in the absence of the proposed mitigation
measures, with most species predicted to experience no Level A
harassment based on modeling results. In addition, the potential for
injury is expected to be greatly minimized through implementation of
the proposed mitigation measures including soft start and the
implementation of clearance zones that would facilitate a delay of pile
driving if marine mammals were observed approaching or within areas
that could be ensonified above sound levels that could result in
auditory injury. Given sufficient notice through use of soft start,
marine mammals are expected to move away from a sound source that is
annoying prior to its becoming potentially injurious or resulting in
more severe behavioral reactions.
We expect that any exposures above the Level A harassment threshold
would be in the form of slight PTS, i.e. minor degradation of hearing
capabilities within regions of hearing that align most completely with
the energy produced by pile driving (i.e. the low-frequency region
below 2 kHz), not severe hearing impairment. If hearing impairment
occurs, it is most likely that the affected animal would lose a few
decibels in its hearing sensitivity, which in most cases is not likely
to meaningfully affect its ability to forage and communicate with
conspecifics. However, given sufficient notice through use of soft
start, marine mammals are expected to move away from a sound source
that is annoying prior to its becoming potentially injurious or
resulting in more severe behavioral reactions.
Additionally, the numbers of exposures above the Level A harassment
proposed for authorization are very low for all marine mammal stocks
and species: For 9 of 11 stocks, we propose to authorize no takes by
Level A harassment; for the remaining two stocks we propose to
authorize no more than 12 takes by Level A harassment. As described
above, we expect that marine mammals would be likely to move away from
a sound source that represents an aversive stimulus, especially at
levels that would be expected to result in PTS, given sufficient notice
through use of soft start, thereby minimizing the degree of PTS that
would be incurred. No serious injury or mortality of any marine mammal
stocks are anticipated or proposed for authorization. Serious injury or
mortality as a result of the proposed activities would not be expected
even in the absence of the proposed mitigation and monitoring measures.
Repeated exposures of individuals to relatively low levels of sound
outside of preferred habitat areas are unlikely to significantly
disrupt critical behaviors. Thus, even repeated Level B harassment of
some small subset of an overall stock is unlikely to result in any
significant realized decrease in viability for the affected
individuals, and thus would not result in any adverse impact to the
stock as a whole. Instances of more severe behavioral harassment are
expected to be minimized by proposed mitigation and monitoring
measures. Effects on individuals that are taken by Level B harassment,
on the basis of reports in the literature as well as monitoring from
other similar activities, will likely be limited to reactions such as
increased swimming speeds, increased surfacing time, or decreased
foraging (if such activity were occurring) (e.g., Thorson and Reyff,
2006; HDR, Inc., 2012; Lerma, 2014). Most likely, individuals will
simply move away from the sound source and temporarily avoid the area
where pile driving is occurring. Therefore, we expect that animals
disturbed by project sound would simply avoid the area during pile
driving in favor of other, similar habitats. We expect that any
avoidance of the project area by marine mammals would be temporary in
nature and that any marine mammals that avoid the project area during
construction activities would not be permanently displaced.
Feeding behavior is not likely to be significantly impacted, as
prey species are mobile and are broadly distributed throughout the
project area; therefore, marine mammals that may be temporarily
displaced during construction activities are expected to be able to
resume foraging once they have moved away from areas with disturbing
levels of underwater noise. Because of the temporary nature of the
disturbance and the availability of similar habitat and resources in
the surrounding area, the impacts to marine mammals and the food
sources that they utilize are not expected to cause significant or
long-term consequences for individual marine mammals or their
populations. There are no areas of notable biological significance for
marine mammal feeding known to exist in the project area. In addition,
there are no rookeries, mating areas, calving areas or migratory areas
known to be biologically important to marine mammals within the
proposed project area.
NMFS concludes that exposures to marine mammals due to the proposed
project would result in only short-term effects to individuals exposed.
Marine mammals may temporarily avoid the immediate area but are not
expected to permanently abandon the area. Impacts to breeding, feeding,
sheltering, resting, or migration are not expected, nor are shifts in
habitat use, distribution, or foraging success. NMFS does not
anticipate the marine mammal takes that would result from the proposed
project would impact annual rates of recruitment or survival.
As described above, north Atlantic right, humpback, and minke
whales, and gray, harbor and harp seals are experiencing ongoing UMEs.
For North Atlantic right whales, as described above, no injury as a
result of the proposed project is expected or proposed for
authorization, and Level B harassment takes of right whales are
expected to be in the form of avoidance of the immediate area of
construction. In addition, the number of exposures above the Level B
harassment threshold are minimal (i.e., 2). As no injury or mortality
is expected or proposed for authorization, and Level B harassment of
North Atlantic right whales will be reduced to the level of least
practicable adverse impact through use of proposed mitigation measures,
the proposed authorized takes of right whales would not exacerbate or
compound the ongoing UME in any way. For minke whales, although the
ongoing UME is under investigation (as occurs for all UMEs), this event
does not provide cause for concern regarding population level impacts,
as the likely population abundance is greater than 20,000
[[Page 45982]]
whales. Even though the PBR value is based on an abundance for U.S.
waters that is negatively biased and a small fraction of the true
population abundance, annual M/SI does not exceed the calculated PBR
value for minke whales. With regard to humpback whales, the UME does
not yet provide cause for concern regarding population-level impacts.
Despite the UME, the relevant population of humpback whales (the West
Indies breeding population, or distinct population segment (DPS))
remains healthy. The West Indies DPS, which consists of the whales
whose breeding range includes the Atlantic margin of the Antilles from
Cuba to northern Venezuela, and whose feeding range primarily includes
the Gulf of Maine, eastern Canada, and western Greenland, was delisted.
The status review identified harmful algal blooms, vessel collisions,
and fishing gear entanglements as relevant threats for this DPS, but
noted that all other threats are considered likely to have no or minor
impact on population size or the growth rate of this DPS (Bettridge et
al., 2015). As described in Bettridge et al. (2015), the West Indies
DPS has a substantial population size (i.e., approximately 10,000;
Stevick et al., 2003; Smith et al., 1999; Bettridge et al., 2015), and
appears to be experiencing consistent growth.
With regard to gray seals, harbor seals and harp seals, although
the ongoing UME is under investigation, the UME does not yet provide
cause for concern regarding population-level impacts to any of these
stocks. For harbor seals, the population abundance is over 75,000 and
annual M/SI (345) is well below PBR (2,006) (Hayes et al., 2018). For
gray seals, the population abundance is over 27,000, and abundance is
likely increasing in the U.S. Atlantic EEZ and in Canada (Hayes et al.,
2018). For harp seals, the current population trend in U.S. waters is
unknown, as is PBR (Hayes et al., 2018), however the population
abundance is over 7 million seals, suggesting that the UME is unlikely
to result in population-level impacts (Hayes et al., 2018).
Proposed authorized takes by Level A harassment for all species are
very low (i.e., no more than 12 takes by Level A harassment proposed
for any of these species) and as described above, any Level A
harassment would be expected to be in the form of slight PTS, i.e.
minor degradation of hearing capabilities which is not likely to
meaningfully affect the ability to forage or communicate with
conspecifics. No serious injury or mortality is expected or proposed
for authorization, and Level B harassment of North Atlantic right,
humpback and minke whales and gray, harbor and harp seals will be
reduced to the level of least practicable adverse impact through use of
proposed mitigation measures. As such, the proposed authorized takes of
North Atlantic right, humpback and minke whales and gray, harbor and
harp seals would not exacerbate or compound the ongoing UMEs in any
way.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
this activity are not expected to adversely affect the species or stock
through effects on annual rates of recruitment or survival:
No mortality or serious injury is anticipated or proposed
for authorization;
The anticipated impacts of the proposed activity on marine
mammals would be temporary behavioral changes due to avoidance of the
project area and limited instances of Level A harassment in the form of
a slight PTS for two marine mammal stocks;
Potential instances of exposure above the Level A
harassment threshold are expected to be relatively low for most
species; any potential for exposures above the Level A harassment
threshold would be minimized by proposed mitigation measures including
clearance zones;
Total proposed authorized takes as a percentage of
population are low for all species and stocks (i.e., less than 24
percent for one stock and less than 7 percent for the remaining 10
stocks);
The availability of alternate areas of similar habitat
value for marine mammals to temporarily vacate the project area during
the proposed project to avoid exposure to sounds from the activity;
Effects on species that serve as prey species for marine
mammals from the proposed project are expected to be short-term and are
not expected to result in significant or long-term consequences for
individual marine mammals, or to contribute to adverse impacts on their
populations;
There are no known important feeding, breeding, calving or
migratory areas in the project area.
The proposed mitigation measures, including visual and
acoustic monitoring, clearance zones, and soft start, are expected to
minimize potential impacts to marine mammals.
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.
We propose to authorize incidental take of 11 marine mammal stocks.
The total amount of taking proposed for authorization is less than 24
percent for one of these stocks, and less than 7 percent for all
remaining stocks (Table 11), which we consider to be relatively small
percentages and we preliminarily find are small numbers of marine
mammals relative to the estimated overall population abundances for
those stocks.
Based on the analysis contained herein of the proposed activity
(including the proposed mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS preliminarily finds that small
numbers of marine mammals will be taken relative to the population size
of all 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. 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
[[Page 45983]]
ESA compliance for the issuance of IHAs, NMFS consults internally
whenever we propose to authorize take for endangered or threatened
species.
NMFS is proposing to authorize take of North Atlantic right whales
and fin whales, which are listed under the ESA. The NMFS Office of
Protected Resources has requested initiation of Section 7 consultation
with the NMFS Greater Atlantic Regional Fisheries Office for the
issuance of this IHA. NMFS will conclude the ESA consultation prior to
reaching a determination regarding the proposed issuance of the
authorization.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to Transco for conducting construction activities in
Raritan Bay for a period of one year, provided the previously mentioned
mitigation, monitoring, and reporting requirements are incorporated. A
draft of the proposed IHA can be found at: www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.
Request for Public Comments
We request comment on our analyses, the proposed authorization, and
any other aspect of this Notice of Proposed IHA for the proposed
action. We also request at this time comment on the potential renewal
of this proposed IHA as described in the paragraph below. Please
include with your comments any supporting data or literature citations
to help inform decisions on the request for this IHA or a subsequent
Renewal.
On a case-by-case basis, NMFS may issue a one-year IHA renewal with
an additional 15 days for public comments when (1) another year of
identical or nearly identical activities as described in the Specified
Activities section of this notice is planned or (2) the activities as
described in the Specified Activities section of this notice would not
be completed by the time the IHA expires and a Renewal would allow for
completion of the activities beyond that described in the Dates and
Duration section of this notice, provided all of the following
conditions are met:
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 under the
requested Renewal are identical to the activities analyzed under the
initial IHA, are a subset of the activities, or include changes so
minor (e.g., reduction in pile size) that the changes do not affect the
previous analyses, mitigation and monitoring requirements, or take
estimates (with the exception of reducing the type or amount of take
because only a subset of the initially analyzed activities remain to be
completed under the Renewal).
(2) A preliminary monitoring report showing the results of the
required monitoring to date and an explanation showing that the
monitoring results do not indicate impacts of a scale or nature not
previously analyzed or authorized.
Upon review of the request for Renewal, the status of the
affected species or stocks, and any other pertinent information, NMFS
determines that there are no more than minor changes in the activities,
the mitigation and monitoring measures will remain the same and
appropriate, and the findings in the initial IHA remain valid.
Dated: August 28, 2019.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2019-18931 Filed 8-30-19; 8:45 am]
BILLING CODE 3510-22-P