text:
[Federal Register Volume 87, Number 4 (Thursday, January 6, 2022)]
[Pages 806-866]
[[Page 805]]
Takes of Marine Mammals Incidental to Specified Activities; Taking
Marine Mammals Incidental to Construction of the South Fork Offshore
Wind Project; Notice
Federal Register / Vol. 87 , No. 4 / Thursday, January 6, 2022 /
[RTID 0648-XB435]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Construction of the South Fork
Offshore Wind Project
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of an incidental harassment authorization.
SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued an incidental harassment authorization (IHA) to
South Fork Wind, LLC (South Fork Wind) to take, by Level A harassment
and Level B harassment, marine mammals during construction of a
commercial wind energy project offshore New York, Rhode Island, and
Massachusetts.
DATES: This IHA is valid from November 15, 2022 through November 14,
FOR FURTHER INFORMATION CONTACT: Carter Esch, Office of Protected
Resources, NMFS, (301) 427-8421. 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.
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are issued or, if the taking is limited to harassment, a notice of a
proposed incidental take authorization (ITA) 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.
Summary of Request
On March 15, 2019, NMFS received a request from South Fork Wind for
an IHA to take marine mammals incidental to construction of an wind
energy project offshore of New York, Rhode Island, and Massachusetts.
Following a delay of the project, South Fork Wind submitted an updated
version of the application on June 3, 2020, and then a revised version
September 14, 2020. The application was deemed adequate and complete on
September 15, 2020. However, on December 15, 2020, South Fork Wind
submitted a subsequent application due to changes to the project scope.
NMFS deemed the application adequate and complete on December 16, 2020.
A notice of the proposed IHA was published in the Federal Register on
February 5, 2021 (86 FR 8490). In response to South Fork Wind's request
and in consideration of public comments, NMFS has authorized the taking
of 15 species of marine mammals by harassment. Neither South Fork Wind
nor NMFS expects serious injury or mortality to result from this
activity and, therefore, an IHA is appropriate.
South Fork Wind plans to construct a 90-180 megawatt (MW)
commercial offshore wind energy project in the South Fork Wind Farm
(SFWF) Lease Area OCS-A 0517 (SFWF; Figure 1 here, and see Figure 1 in
the IHA application for more detail), southeast of Rhode Island within
the Rhode Island-Massachusetts Wind Energy Area (RI/MA WEA), including
an export cable corridor connecting the SFWF to one of two landing
locations on Long Island, New York. The project would consist of the
installation of up to 15 offshore wind turbine generators (WTGs) and
one offshore substation (OSS), an onshore substation, offshore and
onshore cabling, and onshore operations and maintenance facilities
(Figure 1). Each WTG would interconnect with the OSS via an inter-array
submarine cable system. The offshore export cable transmission system
would connect the OSS to an existing mainland electric grid in East
Hampton, New York. A temporary sheet pile cofferdam may be installed
where the offshore export cable conduit exits from the seabed to
contain drilling returns and prevent the excavated sediments from
silting back into the Horizontal Directional Drill (HDD) exit pit. The
final location of the cofferdam will be dependent upon the selected
cable landing site. Alternatively, a temporary casing pipe may be used
in place of the cofferdam at the same location.
Take of marine mammals may occur incidental to the construction of
the project due to in-water noise exposure resulting from (1) impact
pile-driving activities associated with installation of WTG and OSS
foundations, (2) vibratory pile driving associated with the
installation and removal of a temporary cofferdam nearshore, or impact
hammering and vibratory pile driving associated with installation of a
casing pipe, and (3) surveys, using high-resolution geophysical (HRG)
equipment, of the inter-array cable and export cable construction area
(construction surveys).
South Fork Wind plans to install the WTGs and OSS in the 55.4
square kilometer (km\2\) (13,700 acre) Lease Area (Figure 1). At its
nearest point, the SFWF would be approximately 30 kilometers (km) (19
miles (mi)) southeast of Block Island, Rhode Island, and 56 km (35 mi)
east of Montauk Point, New York. The South Fork Wind export cable
routes (SFEC) would connect SFWF to one of two landing locations on
Long Island, New York, where a temporary cofferdam or casing pipe may
be installed where the SFEC exits the seabed. Water depths in the SFWF
and SFEC range from approximately 33-90 meters (m) (108-295 feet (ft)).
[GRAPHIC] [TIFF OMITTED] TN06JA22.002
Since publication of the proposed IHA, South Fork Wind communicated
to NMFS that construction of the project, beginning with the nearshore
cofferdam or casing pipe, is now planned to commence in November 2022,
rather than between April and May 2022 (as indicated in the proposed
IHA). Either the temporary cofferdam or casing pile and support piles
may be installed for the sea-to-shore cable connection and, if
required, would likely be installed between November 2022 and May 2023
(removal could occur anytime through the expiration of the IHA). If
used, installation and removal of the cofferdam are each expected to
take 18 hours of vibratory pile driving. Alternatively, installation
and removal of the casing pipe and support piles are each expected to
take approximately four hours.
Up to 16 days of impact pile driving to install the WTGs and OSS
may occur on any day between May 1, 2023 and November 14, 2023. The
monopiles supporting the WTGs and OSS (the maximum number would be 16
to correspond to 1 OSS and the maximum of 15 WTGs) will be installed
between May 1, 2023, and November 14, 2023. For monopile installation,
a typical pile-driving operation is expected to take approximately 2-4
hours to achieve the target penetration depth. No more than one
monopile could potentially be driven into the seabed per day.
Accordingly, concurrent driving (i.e., the driving of more than one
pile at the same time) would not occur. Up to 60 days of construction
surveys may be conducted throughout the 12-month period of
effectiveness of the IHA.
Cable Laying
Cable burial operations will occur both in the SFWF for the inter-
array cables connecting the WTGs to the OSS and in the SFEC for the
cables carrying power from the OSS to land. Inter-array cables will
connect the 15 WTGs to the OSS. A single offshore export cable will
connect the OSS to the shore. The offshore export and inter-array
cables will be buried in the seabed at a target depth of up to 1.2-2.8
m (4-6 ft). Installation of the offshore export cable is anticipated to
take approximately 2 months. The estimated installation time for the
inter-array cables is approximately 4 months. All cable burial
operations will follow installation of the monopile foundations, as the
foundations must be in place to provide connection points for the
export cable and inter-array cables. Installation days are not
continuous and do not include equipment preparation or downtime that
may result from weather or maintenance. Equipment preparation is not
considered a source of marine mammal disturbance or harassment.
Some dredging may be required prior to cable laying due to the
presence of sand waves. The upper portions of sand waves may be removed
via mechanical or hydraulic means in order to achieve the proper burial
depth below the stable sea bottom. The majority of the export and
inter-array cable is expected to be installed using simultaneous lay
and bury via jet plowing. Jet plowing entails the use of an adjustable
blade, or plow, which rests on the seafloor and is towed by a surface
vessel. The plow creates a narrow trench at the desired depth, while
water jets fluidize the sediment within the trench. The cable is then
fed through the plow and is laid into the trench as it moves forward.
The fluidized sediments then settle back down into the trench and bury
the cable. The majority of the inter-array
cable is also expected to be installed via jet plowing. Other methods,
such as mechanical plowing or trenching, may be needed in areas of
coarser or more consolidated sediment, rocky bottom, or other difficult
conditions in order to ensure a proper burial depth. The jet plowing
tool may be based from a seafloor tractor or a sled deployed from a
vessel. A mechanical plow may also deployed from a vessel. More
information on cable laying associated with the project is provided in
South Fork Wind's Construction and Operations Plan (SFWF COP; South
Fork Wind, 2020). As the only potential impacts from these activities
are sediment suspension and very low noise emissions, the potential for
take of marine mammals to result from these activities is so low as to
be discountable and South Fork Wind did not request, and NMFS does not
authorize, any take associated with cable laying. Therefore, cable
laying activities are not discussed further in this document.
Construction-Related Vessel Activity
During construction of the project, South Fork Wind anticipates
that an average of approximately 5-10 vessels will operate during a
typical work day in the SFWF and along the SFEC. Many of these vessels
will remain in the SFWF or SFEC for days or weeks at a time,
potentially making only infrequent trips to port for bunkering and
provisioning, as needed. Although South Fork Wind estimates that 20
one-way transits between the SFWF and port(s) will be required per
month, the actual number of vessels involved in the project at one time
will be highly dependent on the project's final schedule, the final
design of the project's components, and the logistics needed to ensure
compliance with the Jones Act, a Federal law that regulates maritime
commerce in the United States.
Existing vessel traffic in the vicinity of the project area
southeast of Rhode Island is relatively high and marine mammals in the
area are expected to be somewhat habituated to vessel noise. In
addition, construction vessels would be stationary on site for
significant periods and the large vessels would travel to and from the
site at relatively low speeds. Project-related vessels would be
required to adhere to several mitigation measures designed to reduce
the potential for marine mammals to be struck by vessels associated
with the project; these measures are described further below (see
Mitigation). As part of various construction-related activities,
including cable laying and construction material delivery, dynamic
positioning thrusters may be utilized to hold vessels in position or
move slowly. Sound produced through use of dynamic positioning
thrusters is similar to that produced by transiting vessels, and
dynamic positioning thrusters are typically operated either in a
similarly predictable manner or used for short durations around
stationary activities. Sound produced by dynamic positioning thrusters
would be preceded by, and associated with, sound from ongoing vessel
noise and would be similar in nature; thus, any marine mammals in the
vicinity of the activity would be aware of the vessel's presence,
further reducing the potential for startle or flight responses on the
part of marine mammals. Construction-related vessel activity, including
the use of dynamic positioning thrusters, is not expected to result in
take of marine mammals and South Fork Wind did not request, and NMFS
does not authorize, any takes associated with construction-related
vessel activity. Accordingly, these activities are not discussed
further in this document.
Installation of WTGs and OSS
A monopile, the only type of foundation that will be installed, is
a single, hollow cylinder fabricated from steel that is secured in the
seabed. The monopiles installed would support up to 15 WTGs and single
OSS, and would be 11 m (36 ft) in diameter, up to 95 m (312 ft) in
length and driven to a maximum penetration depth of 50 m (164 ft). A
schematic diagram showing potential heights and dimensions of the
various components of a monopile foundation are shown in Figure 3.1-2
of the SFWF COP (South Fork Wind, 2020), available online at: https://www.boem.gov/renewable-energy/state-activities/south-fork.
All monopiles would be installed with a hydraulic impact hammer.
Impact pile driving entails the use of a hammer that utilizes a rising
and falling piston to repeatedly strike a pile and drive it into the
ground. Using a crane, the installation vessel would upend the
monopile, place it in the gripper frame, and then lower the monopile to
the seafloor. The gripper frame would stabilize the monopile's vertical
alignment before and during piling. Once the monopile is lowered to the
seafloor, the crane hook would be released and the hydraulic hammer
would be picked up and placed on top of the monopile. A temporary steel
cap called a helmet would be placed on top of the pile to minimize
damage to the head during impact driving. The largest hammer South Fork
Wind expects to use for driving monopiles produces up to 4,000
kilojoules (kJ) of energy (however, required energy may ultimately be
far less than 4,000 kJ). As described in the Mitigation section below,
South Fork Wind would utilize a single big bubble curtain (BBC) paired
with an additional noise mitigation device, or a double big bubble
curtain (dBBC) during all impact pile driving of monopiles.
The intensity (i.e., hammer energy level) of impact pile driving of
monopiles would be gradually increased based on the resistance from the
sediments that is experienced. The strike rate for the monopile
foundations is estimated to be 36 strikes per minute. Two impact pile-
driving scenarios for monopile installation were considered for SFWF
(Table 1). The standard impact pile-driving scenario would require an
estimated 4,500 strikes for the pile to reach the target penetration
depth, with an average installation time of 140 minutes for one pile.
In the event that a pile location presents denser substrate conditions
and requires more strikes to reach the target penetration depth, a
difficult-to-drive pile scenario was considered, for which 8,000
strikes and approximately 250 minutes would be required to install one
pile.
Installation and Removal of Temporary Cofferdam
Before cable-laying HDD begins, a temporary cofferdam could be
installed at the endpoint of the HDD starting point, where the SFEC
conduit exits from the seabed. The cofferdam would be less than 600 m
(1,969 ft) offshore from the mean high water line (MHWL), in 7.6 to
12.2 m (25 to 40 ft) water depth, depending on the final siting point.
The cofferdam, up to 22.9 m (75 ft) by 7.7 m (25 ft), would serve as
containment for the drilling returns during the HDD installation to
keep the excavation free of debris and silt. The cofferdam may be
installed as either a sheet pile structure driven into the seabed or a
gravity cell structure placed on the seafloor using ballast weight.
Installation of a gravity cell cofferdam would not result in incidental
take of marine mammals and is not analyzed further in this document.
Installation of the 19.5 m (64 ft) long, 0.95 centimeters (cm) (0.375
inches (in)) thick Z-type sheet pile cofferdam, and drilling support,
would be conducted from an offshore barge anchored near the cofferdam.
If the potential cofferdam is installed (using sheet piles), a
vibratory hammer would be used to drive the sidewalls and endwalls into
the seabed to a depth of approximately 1.8 m (6 ft); sections of the
shoreside endwall would be
driven to a depth of up to 9 m (30 ft) to facilitate the HDD entering
underneath the endwall. Cofferdam removal would consist of pile removal
using a vibratory hammer, after HDD operations are complete and the
conduit is installed (see Table 1 for a summary of potential vibratory
pile-driving activity).
Vibratory hammering is accomplished by rapidly alternating (~250
Hertz (Hz)) forces to the pile. A system of counter-rotating eccentric
weights powered by hydraulic motors is designed such that horizontal
vibrations cancel out, while vertical vibrations are transmitted into
the pile. The vibrations produced cause liquefaction of the substrate
surrounding the pile, enabling the pile to be driven into the ground
using the weight of the pile plus the impact hammer. If the gravity
cell installation technique is not practicable, South Fork Wind
anticipates that any vibratory pile driving of sheet piles would occur
for a total of 36 hours (18 hours for installation, 18 hours for
removal).
The source levels and source characteristics associated with
vibratory pile driving would generally be similar to those produced
through other concurrent use of South Fork Wind's vessels and related
construction equipment. Any elevated noise levels produced through
vibratory pile driving are expected to be of relatively short duration,
and with low source level values. However, it is possible that if
marine mammals are exposed to sound from vibratory pile driving, they
may alert to the sound and potentially exhibit a behavioral response
that rises to the level of take.
Installation of Casing Pipe
The temporary casing pipe could be installed at the currently
planned exit pit location. The casing pipe would be driven into the
seabed at the approach angle of the HDD, and would extend from the
seabed up through the water column to the sea surface where a work
vessel would be able to access the open end of the pipe. The casing
pipe may require that temporary support piles be installed to ensure
pipe stability. Temporary support piles would consist of up to 8 steel
sheet piles temporarily driven into the seabed using a vibratory pile
driver. It is anticipated that the casing pipe would consist of a steel
pipe pile, approximately 48- to 60-inch diameter and approximately 300
feet in length; installation would likely be accomplished using a small
pneumatic impact hammer (e.g., Grundoram Taurus or similar), to drive
the pipe in the seabed. It is estimated that the hammer operates at up
to 18.6 kJ and that impact hammering of the casing pipe would take
approximately two hours complete. Installation of the steel sheet
support piles would take an additional two hours. Once the HDD
operation has been completed, the casing pipe and support piles would
be removed over a similar timeframe and using a similar methodology to
that used for installation. As mentioned previously, acoustic impacts
associated with installation of the casing pipe (and support piles, if
needed) are expected to be less than or equal to, and over a much
shorter duration than, impacts from installation of a cofferdam. South
Fork Wind will determine whether a cofferdam or casing pipe will be
installed, if required. However, installation of a cofferdam was
carried forward in the analyses here, given the large size of the Level
B harassment zone and the longer duration of the activity.
Table 1--Summary of Pile-driving Activities for SFWF and SFEC
Number of                                         Number of
Pile-driving method         Pile size          piles        Strikes/pile    Duration/pile     piling days
Impact......................  11 m monopile..              16  Standard pile:   Standard pile:   Standard
4,500.           140 minutes.     scenario: 30.
Difficult pile:  Difficult pile:  Maximum
Vibratory \1\...............  19.5 m long/             \2\ 80  ...............  18 hours.......  Installation: 1-
0.95 cm thick                                    18 hours.......   3.
sheet pile.                                                       Removal: 1-3.
\1\ South Fork Wind would install either the sheet pile cofferdam or casing pipe, not both. Because vibratory
pile driving associated with cofferdam installation/removal results in the largest harassment zones and
requires the most amount of time, this activity was carried forward in our analysis (see Estimated Take
section).
\2\ Approximation; the actual number will be based on final engineering design.
Construction Surveys
The construction surveys would be supported by up to four vessels
working concurrently throughout the project area. Construction surveys
would occur throughout the 12-month period of effectiveness for the
IHA. HRG survey equipment would either be deployed from remotely
operated vehicles (ROVs) or mounted to or towed behind the survey
vessel at a typical survey speed of approximately 4.0 knots (kts) (7.4
km) per hour.
Table 2 identifies all the representative HRG survey equipment that
operates below 180 kilohertz (kHz) (i.e., at frequencies that are
audible and have the potential to disturb marine mammals) that may be
used in support of planned construction survey activities, and are
likely to be detected by marine mammals given the source level,
frequency, and beamwidth of the equipment. For discussion of acoustic
terminology, please see the Potential Effects of Specified Activities
on Marine Mammals and their Habitat and Estimated Take sections in the
notice of the proposed IHA (86 FR 8490; February 5, 2021).
Table 2--Summary Of Representative HRG Survey Equipment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Operating                                                                         Pulse
HRG equipment category            Specific HRG         frequency     Source level    Source level      Beamwidth     Typical pulse    repetition
equipment         range (kHz)      (dB rms)       (dB 0-peak)      (degrees)     duration (ms)       rate
Shallow Sub-bottom Profilers......  ET 216 (2000DS or          2-16; 2-8             195               -              24              20               6
3200 top unit).
ET 424..............            4-24             176               -              71             3.4               2
ET 512..............          0.7-12             179               -              80               9               8
GeoPulse 5430A......            2-17             196               -              55              50              10
TB Chirp III--TTV                2-7             197               -             100              60              15
Medium Sub-bottom Profilers.......  AA, Dura-spark UHD           0.3-1.2             203             211            Omni             1.1               4
(400 tips, 500
J).\1\
AA, Dura-spark UHD           0.3-1.2             203             211            Omni             1.1               4
(400 + 400).\1\
GeoMarine, Geo-                0.4-5             203             211            Omni             1.1               2
Source or similar
dual 400 tip
sparker (<=800
GeoMarine Geo-Source         0.3-1.2             203             211            Omni             1.1               4
200 tip light
weight sparker (400
200-400 tip
freshwater sparker
(400 J).\1\
AA, triple plate               0.1-5             205             211              80             0.6               4
S[dash]Boom (700-
1,000 J).\2\
- = not applicable; NR = not reported; AA = Applied Acoustics; dB = decibel; ET = EdgeTech; J = joule; Omni = omnidirectional source.
\1\ The Dura-spark measurements and specifications provided in Crocker and Fratantonio (2016) were used for all sparker systems proposed for the survey.
The data provided in Crocker and Fratantonio (2016) represent the most applicable data for similar sparker systems with comparable operating methods
and settings when manufacturer or other reliable measurements are not available.
\2\ Crocker and Fratantonio (2016) provide S-Boom measurements using two different power sources (CSP-D700 and CSP-N). The CSP-D700 power source was
used in the 700 J measurements but not in the 1,000 J measurements. The CSP-N source was measured for both 700 J and 1,000 J operations but resulted
in a lower SL; therefore, the single maximum SL value was used for both operational levels of the S-Boom.
A detailed description of South Fork Wind's planned construction
activities is provided in the notice of the proposed IHA (86 FR 8490;
February 5, 2021). Since that time, South Fork Wind has not proposed
any changes to its construction activities through the IHA process,
other than the casing pipe alternative to installation of a temporary
cofferdam at the exit pit location of the export cable (as described
above and below). Therefore, a detailed description is not provided
here. Please refer to that notice for the detailed description of the
specified activity. Mitigation, monitoring, and reporting measures are
described in detail later in this document (please see Mitigation and
Monitoring and Reporting below). Modifications and additions to the
mitigation and monitoring measures have occurred since the proposed IHA
was published. All changes since the proposed IHA have been summarized
in the Changes from Proposed IHA to Final IHA section and described in
detail in their respective sections and/or the comment responses below.
Comment 1: The Marine Mammal Commission (Commission) claims that
ranges to the Level B harassment isopleth for impact pile driving of
11-m monopiles are underestimated by JASCO (the source of the modeling
used for NMFS' analysis) for the South Fork Wind project because,
primarily, Lippert et al. (2016) indicated that JASCO's time-domain
finite difference pile-driving source model (TDFD PDSM) predicted lower
sound exposure levels (SELs) in the far-field region than various
finite-element (FE) models. The Commission notes that while the exact
source level difference between the TDFD PDSM and FE models was not
reported, Lippert et al. (2016) indicated that the SELs predicted by
JASCO's TDFD PDSM were approximately 2.5 dB lower than the SELs
predicted by the FE models at 750-m distance from the source. To help
resolve this issue, the Commission suggests that JASCO could add 3 dB
to the SEL predictions from the TDFD PDSM to be consistent with
differences identified in Lippert et al. (2016). In addition, the
Commission suggests that NMFS could use the dampened cylindrical
spreading model (DCSM; Lippert et al., 2018) to substantiate the Level
B harassment zones. Finally, the Commission seeks clarity regarding the
models that JASCO used, and how JASCO's model(s) would compare to the
model used for the COMPILE workshop benchmark case in Lippert et al.
Response: The Commission (1) recommends adding 3 dB based on the
COMPILE workshop comparison (Lippert et al. 2016), (2) recommends that
NMFS use the DCSM to substantiate Level B harassment zones, and (3)
seeks an explanation of the models JASCO used and how JASCO's model(s)
would compare to the model used in the COMPILE workshop benchmark case.
Adding 3 dB (or 2.5 dB, the value from which the Commission apparently
rounded up to 3 dB) to the JASCO SEL predictions at 750 m may bring
JASCO's predictions using the TDFD PDSM into line with the FE
predictions for the COMPILE scenario, but it is not clear that this
would be more accurate. This approach assumes that the FE models are
correct, but Lippert et al. (2016) also state ``a drawback of [the FE]
approach is that it simulates the energy loss due to friction in an
indirect and rather nonphysical way.'' Therefore, NMFS has concluded
that adding 3 dB to the SEL predictions from JASCO's TDFD PDSM is not
warranted.
NMFS agrees that there can generally be utility in comparing the
results of analogous models, but the
Commission's suggestion to use the DCSM (Lippert et al., 2016) as a way
to verify the range to the Level B harassment isopleth predictions
estimated by JASCO is problematic. The DCSM is a modified geometric
model of propagation that applies a general correction for the
interaction of sound with the environmental parameters (e.g.,
absorption, and the assumption of cylindrical spreading), whereas the
full-wave parabolic-equation based propagation model (FWRAM (<2kHz)),
and Gaussian beam ray-trace model (BELLHOP (>2kHz)) JASCO used take
into account environmental interactions (e.g., bathymetry, sound
velocity profile, geoacoustic properties of the seabed) as the sound
propagates. BELLHOP was inadvertently excluded from the acoustic
modeling report (Denes et al., 2020a), but is run along with FWRAM as
part of the acoustic modeling. The DCSM assumes an apparent source
level for different pile sizes and then uses a simple model of
propagation. While NMFS agrees that DCSM is a valuable tool for some
applications, JASCO's well-tested, range-dependent propagation models
based on solutions to the wave equation represent the preferred
alternative to the simpler DCSM.
The Commission seeks clarity regarding the models used by JASCO.
The force at the top of each monopile, associated with the typical
hammers, was computed using the GRLWEAP 2010 wave equation model
(GRLWEAP, Pile Dynamics 2010), which produced forcing functions. The
source signatures of each monopile were predicted using the TDFD PDSM
to compute the monopile vibrations caused by hammer impact. To
accurately calculate propagation metrics of an impulsive sound, a time-
domain representation of the pressure wave in the water was used. To
model the sound waves associated with the monopile vibration in an
acoustic propagation model, the monopiles are represented as vertical
arrays of discrete point sources. The discrete sources are distributed
throughout the length of the monopile below the sea surface and into
the sediment with vertical separation of 3 m. The length of the
acoustic source is adjusted for the site-specific water depth and
penetration at each energy level, and the section length of the
monopile within the sediment is based on the monopile hammering
schedule (Table 6). Pressure signatures for the point sources are
computed from the particle velocity at the monopile wall up to a
maximum frequency of 2,048 Hz. This frequency range is suitable because
most of the sound energy generated by impact hammering of the monopiles
is below 1 kHz.
As mentioned above, to calculate predicted propagation of sounds
produced during impact pile driving of monopiles below 2 kHz, JASCO
used it's FWRAM, which is an acoustic model based on the wide-angle
parabolic equation (PE) algorithm (Collins 1993). FWRAM computes
synthetic pressure waveforms versus range and depth for range-varying
marine acoustic environments. It takes environmental inputs (e.g.,
bathymetry, sound velocity profile, and seabed geoacoustic profile) and
computes pressure waveforms at grid points of range and depth. Because
the monopile is represented as a linear array and FWRAM employs the
array starter method to accurately model sound propagation from a
spatially distributed source (MacGillivray and Chapman 2012), using
FWRAM ensures accurate characterization of vertical directivity effects
in the near-field zone. JASCO used BELLHOP, a Gaussian beam ray-trace
model that also incorporates environmental inputs, to model propagation
of sound produced above 2 kHz during monopile installation. The beam-
tracing model is basically described as an approximation of a given
source by a fan of beams through the medium. Then, the quantities of
interest (e.g., acoustic pressure at different ranges) are computed at
a specified location by summing the contribution of each of the
individual beams.
The acoustic source signature of vibratory driving of sheet piles
was modeled following the same steps used to model impact pile driving
of monopiles. The forcing function was modeled for a single cycle of
the vibrating hammer using the GRLWEAP 2010 wave equation model (Pile
Dynamics 2010). The TDFD PDSM model was used to compute the resulting
sheet pile vibrations from the stress wave that propagates down the
sheet pile. The radiated sound waves were modeled as discrete point
sources over the 18 m (60 ft) of the sheet pile in the water and
sediment (9 m [30 ft] water depth, 9 m [30 ft] penetration) with a
vertical separation of 10 cm. Sound propagation of the discrete point
sources was predicted with JASCO's Marine Operations Noise Model
(MONM). MONM computes received sound energy, the SEL, for directional
sources. MONM uses a wide-angle parabolic equation solution to the
acoustic wave equation (Collins 1993) based on a version of the U.S.
Naval Research Laboratory's Range-dependent Acoustic Model (RAM).
Similar to FWRAM and BELLHOP, MONM incorporates site-specific
environmental properties. MONM treats frequency dependence by computing
acoustic transmission loss at the center frequencies of 1/3-octave-
bands. At each center frequency, the transmission loss is modeled as a
function of depth and range from the source. Composite broadband
received SELs are then computed by summing the received 1/3-octave-band
levels across the modeled frequency range.
The accuracy of JASCO's TDFD PDSM has been verified by comparing
its output against benchmark scenarios (Lippert et al., 2016). In
addition, JASCO compared the TDFD PDSM predictions to an empirical
model prediction in the Institute of Technology and Applied Physics
(ITAP) report (Bellmann 2020). The empirical model is based on a large
data set of pile-driving sounds, measured at 750 m from the source,
collected during installation of various diameter piles (up to 8 m)
during wind farm installation in the North Sea (ITAP, Bellmann 2020).
As no noise monitoring results exist for 11-m monopiles (yet to be
installed offshore), the ITAP prediction facilitates a way of
validating the source levels of the numerical FD model. The ITAP data
are averaged across different scenarios--pile sizes, different hammers,
water depths, depths of penetration, and environmental conditions--and
the 95th percentile level is reported, whereas the aim of JASCO's
modeling is to estimate the median value. While the ITAP forecast and
the FD source predictions were comparable, there is variance in the
underlying ITAP data and there are parametric choices for the FD model
in the different environments, so an exact match is not expected. As
part of the comparison, it was found that different (but reasonable)
parametric input choices in the TDFD modeling can result in output
differences on the order of the variance in the ITAP data, so it was
concluded that the TDFD modeling approach performed as well as can be
discernible given the available data.
Comment 2: The Commission claims that in situ measurements
collected during the installation of Dominion's Coastal Virginia
Offshore Wind (CVOW) project's 7.8-m monopiles suggest that the range
to the Level B harassment isopleth for installation of 11-m monopiles
presented here has been underestimated. Specifically, the Commission
notes that JASCO estimated the Level B harassment zone for South Fork
Wind's impact driving of 11-m piles to be 4,684 m, assuming a 10-dB
sound attenuation, based on the use of a single BBC and up to 4,000 kJ
hammer energy (see Tables 12 and 13; Denes et al. 2020a), while in situ
measurements made during the CVOW project for impact driving of a 7.8-m
pile with a measured 9-12 dB sound attenuation during use of a dBBC for
a hammer operating at a maximum of 550 kJ estimated the Level B
harassment zone to be 3,891 m (WaterProof 2020).
The Commission suggests that South Fork Wind's use of an impact
hammer with 7.3 times more energy intensity than the impact hammer used
for CVOW (4,000 kJ versus 550 kJ) spread over a 1.4 times larger
circumference than the pile size used in CVOW, would result in
approximately five-fold (or 7 dB) higher sound energy level than was
determined for CVOW. Based on DCSM, a 7-dB difference in source levels,
the measured Level B harassment zone of more than 3,800 m at Dominion,
and environmental conditions for Dominion, the Commission claims that
the measured Level B harassment zone would increase by 81 percent,
resulting in a Level B harassment zone of approximately 6,890 m based
on the increased hammer energies and pile size. Further, the Commission
suggests using DCSM to relate this range to the Level B harassment
isopleth to the acoustic propagation conditions in the South Fork Wind
project area, which the Commission states would result in a Level B
harassment zone of more than 9,600 m for the South Fork Wind project.
Response: Recent acoustic measurements associated with the
installation of two 7.8-m-diameter piles, with the hammer operating at
550 kJ, driven as part of the CVOW project found the range to the Level
B harassment isopleth (160 dB rms) to be 3,891 m, while JASCO's
prediction for 11-m piles with hammer energy of 4000 kJ was 4,684 m.
Both efforts employed comparable mitigation--JASCO assumed broadband
attenuation of 10-dB for acoustic modeling, while 9-12 dB of
attenuation was measured at CVOW using a dBBC situated around the pile
to attenuate noise produced by impact hammering of the pile. The
Commission reasons that because the hammer energy used in JASCO's
acoustic propagation modeling is approximately 7.3 times the energy of
the hammer employed for CVOW, JASCO's predicted range to the Level B
harassment isopleth should be more than double that measured at CVOW
instead of being approximately 20-percent larger. The 3,891-m range to
the Level B harassment isopleth reported for CVOW was obtained by
choosing the maximum measured SPL value produced during impact pile
driving of the monopile. JASCO's predictive modeling produces median
(expected or 50th percentile) SPL values. The 50th percentile SPL
values in CVOW (Waterproof 2020; Table 4.1) are 5-6 dB lower than the
maximum. Using the CVOW 50th percentile SPL values and the acoustic
propagation equations in the CVOW report results in a range to Level B
harassment isopleth of approximately 2,000 m, which is less than half
of the 4,684-m range predicted by JASCO for installation of monopiles
by South Fork Wind. JASCO uses the sound fields predicted during
acoustic modeling in subsequent animal movement modeling to estimate
probabilities of exposure. In the exposure analysis, the median
(equivalently, 50th percentile) sound level values are preferred so
that the probabilities represent likely occurrence. Using maximum or
95th percentile sound field values would systematically bias the marine
mammal exposure probabilities.
Regarding the Commission's estimates of zone sizes using the DCSM,
these are approximations but, in general, NMFS agrees with the logic
presented by the Commission, if one were to use that model. However, as
described above, JASCO's predictions are for the expected (median) SPL,
while the predictions for CVOW use the maximum measured SPL values. If
a 7-dB difference in source level is expected with the larger hammer
and larger pile (compared to CVOW) South Fork Wind plans to use, it
should be noted that there is an approximately 5-dB difference between
the measured maximum SPL and the 50th percentile SPL for the CVOW
project, so JASCO's approximately 20-percent increase in the range to
the Level B harassment isopleth (relative to the range measured for the
CVOW project) seems reasonable for a source level difference of 2 dB.
It should also be noted that there is greater than 5-dB difference in
the levels measured at closest location to the pile reported for the
CVOW projects, indicating that concepts like source level do not really
apply to distributed sources and that propagation may not be captured
well with simple models like DCSM.
Comment 3: The Commission seeks clarity regarding the type and
configuration of the bubble curtain South Fork Wind will utilize during
impact pile driving. In addition, the Commission references Bellmann et
al. (2020), in which the authors report an average of 9-dB sound
attenuation utilizing a BBC as a noise mitigation device for
installation of 8-m monopiles in 40 m of water. The authors indicated
diminishing efficacy of the BBC with increasing water depth, suggesting
that additional noise mitigation devices should be used for pile
diameters greater than or equal to 6 m installed in water depths
greater than 25 m.
Response: The Commission is correct that Bellmann (2020) reported
an average of 9-dB (7 < 9 < 11dB) attenuation using a BBC for a water
depth of 40 m, but this was for an air flow rate of 0.3m\3\/(min*m).
South Fork Wind will use an air flow rate of at least 0.5m\3\/(min*m)
for BBC deployments. As increased air flow results in a stronger BBC,
this will effectively result in more attenuation than reported in
Bellmann et al. (2020). Further, the final IHA requires that South Fork
Wind not use a single BBC as the only means of noise mitigation,
meaning they must pair a single BBC with an additional noise mitigation
device; alternatively, they may use a dBBC. South Fork Wind is
committed to reducing noise levels generated by pile driving to the
lowest levels practicable such that they do not exceed a noise
footprint modeled, assuming a 10-dB attenuation. South Fork Wind is
required to prepare and submit a Pile Driving Plan to NMFS for review
and approval 90 days before the start of pile driving. As part of this
plan, South Fork Wind must include specifications of the bubble
curtain(s) and additional noise mitigation device(s) that will be used
during impact pile driving, as well details on how the bubble
curtain(s) and additional noise mitigation device(s) will be deployed
to reduce noise levels to the maximum extent practicable.
Comment 4: The Commission states that estimated ranges to the Level
B harassment isopleth in JASCO's underwater acoustic modeling report
(Denes et al. 2020a) are smaller than those used in its animal exposure
modeling report (Denes et al., 2020b), and indicated that it is not
clear which zones are correct.
Response: The acoustic range estimates in the animal exposure
modeling report (Denes et al., 2020b; Tables 12 and 13) are
approximately 100 m longer than those shown in the acoustic modeling
report (Denes et al., 2020a; Tables E13 and E14). Tables 12 and 13 in
the animal exposure report show the acoustic ranges to the Level B
harassment isopleth for the most conservative case--the impact hammer
with greater range and at the highest hammer energy level for summer
and winter, respectively. Tables E-13 and E14 of the acoustic modeling
report show the SPL ranges to various isopleths, assuming 10-dB
attenuation, for the IHC S-4000 hammer and Menck
3500S hammer, respectively, at two modeling locations (P1 and P2). The
Menck 3500S operating at 3500 kJ produced slightly longer ranges (Table
14) than the IHC S-4000 operating at 4000 kJ (Table 13). Using the
Menck 3500S data (Table 14), the ranges to the Level B harassment
isopleth in winter are 4,769 (P1) and 4,718 (P2), for an average of
4,744 m. Likewise, the ranges to the Level B harassment isopleth in
summer are 4,443 (P1) and 4,403 (P2), for an average of 4,423 m. The
corresponding ranges to the Level B harassment isopleth, assuming 10-dB
attenuation, in the animal movement modeling report are: 4,535 m
(summer; Table 12) and 4,832 m (winter; Table 13). There is an
approximately 10-m difference when comparing the summer values (4,423 m
vs 4,535 m) and winter values (4,744 m vs 4,832 m). Zones are not used
in animal movement modeling (3D sound fields are) so animal exposure
estimates are not affected by the apparent small difference of zone
radius. Zones are shown in the animal exposure modeling for reference
purposes only.
Comment 5: The Commission seeks clarity regarding (1) how sound
field verification (SFV) will be conducted should lesser hammer
energies be required for installation of the first monopile(s), which
might not be representative of the required hammer energies and
associated acoustic impacts for later piles, and (2) the required
mitigation and monitoring should the measured range to the Level B
harassment isopleth exceed the range produced by acoustic propagation
modeling, assuming 10-dB attenuation (4,684 m).
Response: South Fork Wind will be required to conduct SFV on
multiple piles to capture the spectrum of hammer energies required to
install monopiles in varying substrates throughout the project area.
Specifically, they will monitor the first 3 piles and, if a subsequent
piling location is selected that was not represented by the previous
locations (i.e., substrate composition, water depth), additional SFV
will be required. South Fork Wind has committed to mitigating noise
produced by impact pile driving, such that the ranges to harassment
isopleths align with those modeled, assuming 10-dB attenuation. If the
ranges measured for the first pile are larger than those modeled, South
Fork Wind will be required to make a series of adjustments to the sound
attenuation measures, including (and in the following order): (1) A
reduction in the hammer schedule (the number of strikes at a given
energy level), (2) modifications to the bubble curtain(s), and 3)
implementation of an additional noise mitigation device to further
refine noise mitigation. In the interim between SFV of the first
evaluated pile and the next, South Fork Wind must conduct both visual
and acoustic monitoring of the zones associated with the measured
ranges to the Level A harassment and Level B harassment isopleths for
the first pile. Should additional SFV demonstrate that the ranges to
the Level A harassment and Level B harassment isopleths are still
greater than those modeled assuming 10-dB attenuation, the IHA (see
condition 5(f)(iv)) states that NMFS may adjust the Level A harassment
and Level B harassment zones, and the associated mitigation and
monitoring zones accordingly, for the installation of the remaining
monopiles. In this case, visual monitoring would be adjusted
accordingly by shifting the location of the secondary PSO vessel to
approximately half the measured range to the Level B harassment
isopleth. Clearance and shutdown zones would be adjusted according to
condition 5(f)(iv) of the final IHA. In all cases, passive acoustic
monitoring (PAM) will supplement visual observations. South Fork Wind
is required to establish a PAM system designed to facilitate
localization of baleen whale calls within a 5-km radius of the impact
pile-driving vessel; however, the PAM system will likely have a
detection range of 10 km or more, thus providing ample acoustic
monitoring coverage should the Level B harassment zone be increased in
size. Depending on the extent to which Level A harassment and Level B
harassment zones are expanded, reinitiation of consultation under
Section 7 of the ESA with NMFS GARFO may be required.
Comment 6: The Commission (1) claims that JASCO's assumptions used
to seed its animat modeling were not appropriate, (2) questions whether
the 7-day simulations used in JASCO's exposure modeling appropriately
accounted for the 16 days of proposed pile driving, and (3) suggests
that animal exposure modeling could have been accomplished using 100
Monte Carlo simulations for the 140 and 250 minutes of activities for
installation of standard and difficult-to-drive piles, respectively,
producing density scaled estimates for each activity that could then be
multiplied by the number of days of activities.
Response: It is unclear what the Commission means when claiming
that JASCO's seeding for animat modeling was not appropriate. However,
the use of 7-day simulations can be addressed. Representative 7-day
periods of project construction were simulated (e.g., piling every day,
or every other day). NMFS' Technical Guidance for Assessing the Effects
of Anthropogenic Sound on Marine Mammal Hearing (NMFS 2018) recommends
a 24-hour accumulation period, so 24-hour sliding windows (with 4-hour
advancements) within the 7-day simulations were used to find the
average exposure expected in a 24-hour period that includes pile
driving. This provides a more robust probability calculation of 24-hour
exposure estimates compared to a single-day simulation. The average 24-
hour estimate is then scaled by the number of days of pile driving
(i.e., 15 days of standard pile installations plus 1 day of a
difficult-to-drive pile installation). It is unclear why the Commission
suggests conducting 100 Monte Carlo simulations (or to what that
comment is referring); however, multiple simulations were run. For
example, the piling-every-day simulations consisted of approximately
140 minutes of pile driving in each day of the simulation. JASCO
simulated tens of thousands of animats and determined the average
exposure probability in a 24-hour period. That probability was then
scaled using the real-world density of different species to estimate
the number of individuals expected to exceed a threshold. Note, if the
Commission's suggested use of 100 Monte Carlo simulations is referring
to a Monte Carlo approach to sampling from the different predictions in
a 24-hour period, this could be done but would arrive at the same mean
estimate as scaling the averaged estimates by the number of pile-
driving days, and thus NMFS determined the use of Monte Carlo
simulations is not warranted.
Comment 7: The Commission notes that NMFS did not increase the
proposed numbers of take resulting from impact pile driving to at least
the average group size (based on DoN (2017)) for Level B harassment
take of sperm whales, long-finned pilot whales, and Atlantic spotted
dolphins, and Level A harassment take of blue whales. In addition, the
Commission claims that NMFS did not propose to authorize an appropriate
number of Level A harassment takes of fin whales, Level A harassment
and Level B harassment takes of humpback whales, and Level B harassment
takes for common dolphins and bottlenose dolphins during impact pile
driving, given the frequency of occurrence and group sizes observed in
the South Fork Wind project area during previous monitoring efforts
(A.I.S., Inc. 2017, Smultea Sciences, 2020).
Response: Animal movement modeling that accounts for exposure
within the sound field was used to
estimate take. However, NMFS concurs that density models and animal
movement models may not capture all site-specific conditions nor year-
to-year fluctuations in animal distributions. Where modeled takes were
zero, South Fork Wind requested Level B harassment take for the
following species based on cited references rather than on DoN (2017):
sperm whales (Barkaski and Kelly, 2018) and long finned pilot whales
(Kenney and Vigness-Raposa, 2010).
Given that South Fork Wind already conservatively requested (and
NMFS proposed to authorize) 3 Level B harassment takes of sperm whales
(or one group size; Barkaski and Kelly, 2018) despite animal exposure
modeling resulting in zero Level B harassment takes of sperm whales,
NMFS determined that no further increases in authorized take are
Upon further review of scientific literature, NMFS updated the
reference for average group size for long-finned pilot whales (n=20;
CETAP 1982) and increased authorized take by Level B harassment from 12
to 20 (Table 18). Atlantic spotted dolphins were sighted on two
occasions (approximately 20 individuals total; average group size of
10) during recent monitoring efforts near the South Fork Wind project
area conducted over a 7-month period and covering over 11,000 km of
survey trackline (Smultea Sciences, 2020). Similar monitoring efforts
within the South Fork Wind project area covering 9,597 km from June
through September 2020 detected zero Atlantic spotted dolphins
(Gardline 2021). Barkaski and Kelly (2018) report an average group size
of 13 for Atlantic spotted dolphins, which is similar to the average
group size based on sighting data near the South Fork Wind project area
(10; CSA 2021). To account for group size, NMFS has conservatively
increased take, by Level B harassment, of Atlantic spotted dolphins
from 2 to 13 (Table 18).
NMFS does not agree that take, by Level A harassment, of blue
whales should be increased. Rather, upon further review, and based on
the lack of blue whale sightings during previous monitoring efforts
within and near the South Fork Wind project area (Smultea Sciences,
2020; Gardline 2021), NMFS has determined that any take, by Level A
harassment or Level B harassment, of blue whales resulting from the
project's construction activities is de minimus and, therefore, NMFS
has not authorized take of blue whales by Level B harassment. Tables 18
and 23 have been revised to reflect this change from the notice of the
proposed IHA, which included the proposal of one take, by Level B
harassment, of a blue whale.
South Fork Wind requested, and NMFS proposed to authorize, one
take, by Level A harassment, and 6 takes, by Level B harassment, of fin
whales incidental to impact pile driving. The Level A harassment zone,
assuming 10-dB attenuation, is 1,769 m for fin whales. Given that the
shutdown zone for fin whales (2,000 m) is larger than the Level A
harassment zone (1,769 m), and the relatively small number of monopiles
planned for installation, NMFS has determined that no increases in
take, by Level A harassment or Level B harassment, of fin whales
incidental monopile installation, are warranted.
Because the Level A harassment zone for humpback whales (3,642 m,
assuming 10-dB attenuation) is larger than the 2,000-m shutdown zone,
South Fork Wind requested and NMFS proposed to authorize, 4 takes, by
Level A harassment, of humpback whales in addition to 8 takes, by Level
B harassment. NMFS has determined that, due to the relatively small
number of monopiles planned for installation, 4 takes by Level A
harassment and 8 takes by Level B harassment are appropriate for
Upon further review of scientific literature (DoN 2017; Smultea
Sciences, 2020; CSA 2921; AMAPPS 2021), NMFS has conservatively
selected the largest group size reported among references for common
(35; AMAPPS 2021) and bottlenose (21.6; AMAPPS 2021) dolphins to
incorporate into increases of take, by Level B harassment, for each
species. The group size for each species was multiplied by the number
of days on which impact pile driving of monopiles may occur (16),
resulting in 560 common dolphin and 346 bottlenose dolphin takes, by
Level B harassment.
Comment 8: The Commission noted several perceived inconsistencies,
errors, and omissions in the Federal Register Notice of the proposed
IHA (86 FR 8490; February 5, 2021) and the proposed authorization,
(1) Omission of shutdown, Level A harassment, and Level B
harassment zones in Table 2 of the proposed IHA;
(2) Lack of alignment of mitigation and monitoring measures between
the Federal Register notice and the proposed IHA;
(3) Need to clarify that the 5,000-m clearance and 2,000-m acoustic
shutdown zones for North Atlantic right whales (NARWs) will minimize
the potential for Level A harassment, but not necessarily Level B
harassment (as stated in the notice of the proposed IHA).
Response: The harassment, clearance, and shutdown zone ranges
(which were included in the notice of the proposed IHA but erroneously
excluded from the draft IHA) are now included in the final IHA (Tables
2-6) and align with corresponding tables in this notice. All mitigation
and monitoring measures now align between this notice and the final
IHA. In the final IHA, NMFS is requiring that South Fork Wind shut down
impact pile driving of monopiles if a NARW is sighted at any distance.
On days with good visibility, shutdown may occur based on a NARW
sighting entering or within the limit of the Level B harassment zone
(4,684 m). While this mitigation measure will not necessarily minimize
take by Level B harassment, it might reduce the duration and intensity
of exposure above the Level B harassment isopleth.
Comment 9: The Commission argues that, if NMFS' intent is to
minimize all impacts during impact pile driving, requiring South Fork
Wind to monitor a 2,200-m clearance zone is inadequate given that the
Level B harassment zone is 4,684 m. Further, the Commission asserts
that a single vessel stationed a 2,200 m would not be sufficient to
monitor the farther extents of the zones. The Commission claims that
the range to the farthest extent would be 4,200 m based on the
exclusion zone and more than 6,800 m based on the Commission's
calculation of the size of the Level B harassment zone using DCSM.
Response: NMFS is requiring South Fork Wind to monitor the Level B
harassment zone (4,684 m) prior to all impact pile driving, utilizing a
combination of two PSOs located on the impact pile-driving vessel, two
PSOs located on a dedicated vessel circling the pile-driving vessel at
a radius of 2,200 m from the pile-driving vessel, and PAM capable of
localizing baleen whale calls within a 5-km radius of the impact pile-
driving vessel. The 2,200-m zone to which the Commission is referring
is the minimum visual clearance zone for all baleen whale species other
than the NARW (for which the clearance zone is undefined because any
NARW observed by a PSO stationed on the pile-driving vessel or
dedicated PSO vessel, regardless of distance, would trigger a delay in
pile driving). The use of PAM to complement visual observations will be
particularly important when visibility is limited to the minimum visual
clearance zone rather than the full extent of the Level B harassment
zone. Monitoring must begin 60 minutes prior to initiating pile
driving; however, the clearance zones must be clear of marine mammals
for 30
minutes before pile driving may commence. The final IHA adds and
clarifies all zones and the mitigation and monitoring required to be
implemented by South Fork Wind. It is unclear what method the
Commission used to estimate a range of 4,200 m, or to what that range
refers. Finally, as described above, NMFS does not adopt the use of
DCSM to estimate or substantiate the modeled Level B harassment zone
for impact pile driving, and is proceeding with 4,684 m as the range to
the Level B harassment isopleth. Again, these ranges will be verified
upon the onset of pile driving and the IHA contains measures that must
be followed should SFV indicate ranges are larger than those predicted
by the model.
Comment 10: The Commission states that the measure in the proposed
IHA requiring PAM PSOs to review acoustic detections within 15 minutes
of the original detection to verify whether a NARW has been detected is
not real-time and would not preclude taking.
Response: PAM will occur in real-time, meaning a PAM PSO will be
actively monitoring the hydrophones. However, in some cases, a PAM PSO
cannot immediately identify a call as one from a NARW and requires some
time to analyze the signal. Following the publication of the proposed
IHA, South Fork Wind communicated to NMFS that PAM PSOs will be capable
of reviewing and classifying detections within 5 minutes of the
original detection, better approximating real-time monitoring of NARW
presence. The final IHA and Federal Register notice have been revised
to reflect this updated capability.
Comment 11: The Commission requested more specificity regarding
South Fork Wind's proposed PAM plan (i.e., minimum number, type, and
location of hydrophones; bandwidth/sampling rate; estimated acoustic
detection range; sensitivity of the hydrophones; detection software
planned for use), noting that this information is necessary to ensure
that South Fork Wind can detect, classify, and locate NARWs. ENGOs also
requested that NMFS explain how the number and location of acoustic
detection systems will be adequate to fully cover the area within the
clearance and shutdown zones, particularly during times of high vessel
traffic and development activity. Finally, the Commission recommends
that NMFS consider how the direct strike pulses and reverberation from
pile-driving activity could inhibit detection of marine mammal
vocalizations, particularly those of NARWs.
Response: South Fork Wind is required to submit a detailed PAM plan
to NMFS and BOEM for review and approval at least 90 days prior to the
planned start of construction. The PAM plan must include sufficient
information, including all equipment, procedures, and protocols to
demonstrate that the monitoring and mitigation requirements included in
the authorization will be met. Regarding the Commission's
recommendation that NMFS consider the influence of direct strike pulses
and reverberation on the ability to detect marine mammal vocalizations,
NMFS agrees that the multipaths will potentially spread the signal out
and reduce the ``quiet time'' between pulses, thus increasing masking
and making the detection process during pile driving more difficult.
Additional signal processing methods will be required to enhance signal
detection under such circumstances. The IHA is conditioned such that
hydrophones will not be placed closer than 1 km from the pile being
driven to minimize interference, and that the PAM system must be
capable of detecting whales to implement mitigation within 5 km. The
PAM plan submitted by South Fork Wind must be approved by NMFS prior to
construction.
Comment 12: The Commission noted several perceived errors and
omissions regarding hydroacoustic monitoring reporting requirements for
impact pile driving, recommending that the following should be
included: (1) hydrophone sensitivity, (2) water depth and sediment
type(s) at the pile-driving location(s), (3) ranges to the Level A
SELcum harassment isopleths, (4) fitting of the
hydroacoustic data using DCSM and/or a simple cylindrical spreading
model (following Waterproof (2020)), and 5) ambient noise spectra for
diagnosing issues with hydrophone(s), and that the visibility metrics
and ambient sound level measurements should be omitted from the
reporting requirements.
Response: NMFS concurs with the Commission's recommendation that
the hydroacoustic monitoring report should include (1) hydrophone
sensitivity, water depth and sediment type at the pile location, ranges
to the Level A harassment isopleths, and ambient noise spectra and (2)
omit visibility metrics, and has adjusted those requirements in both
the final IHA and in the Monitoring and Reporting section. In addition,
for comparison of in situ data to sound fields modeled a priori, South
Fork Wind plans to conduct SFV by measuring sound levels at multiple
locations, (e.g., nominal distances of 750; 1,500; 3,000; and 6,000 m).
The SFV results will be fitted using a geometric spreading loss model,
[alpha] [middot] Log(r), to provide the ability to predict sound levels
at any range. The fitting process generates a site-dependent estimate
of the transmission loss coefficient, [alpha], in the geometric
spreading model. This differs from assuming cylindrical spreading loss,
[alpha]=10, as is done in a Damped Cylindrical Spreading Model (DCSM).
The DCSM includes a damping (absorption) term, which may be included
when fitting the geometric model.
NMFS agrees with the Commission that ambient noise spectra should
be reported and that visibility metrics are not a necessary reporting
requirement, and has included these changes in the final IHA. However,
despite the Commission's suggestion, NMFS supports collection of
ambient sound measurements (as proposed by South Fork Wind), as these
data contribute to the overall soundscape characterization within the
WEA and provide context for detections of marine mammals during
construction activities. NMFS has included this requirement in the
final IHA.
Comment 13: The Commission claims that the Level B harassment zone
presented here for vibratory pile driving is overestimated, that the
modeled spectra provided in the Denes et al. (2020a) are inconsistent
with spectra obtained from in situ measurements of similar activities
(e.g., Caltrans 2016; Illingworth and Rodkin 2017), and that the source
level used to model the Level B harassment range for vibratory pile
driving was too high. Using a simple transmission loss calculation and
the estimated distance to the Level B harassment isopleth (36.8 km),
the Commission estimates that the source level would be 173.5 dB re 1
[micro]Pa at 10 m and claims that this source level is higher than that
used by NMFS for installation of smaller piles or sheet piles.
Response: The Commission appears concerned NMFS overestimated the
Level B harassment zone for vibratory pile driving; however, any
difference in the size of the modeled Level B harassment zone using
their back-calculated source level (or any other lower source level) is
minimally impactful given the very short period of activity (no more
than 36 hours). NMFS recognizes that no model is exactly accurate and
that in situ data demonstrate sound levels are not consistent both
vertically and horizontally in the water column or during the same
activity (e.g., installing
2 different piles of the same size/configuration). JASCO maintains, and
NMFS agrees, that the spectra calculated using GRLWEAP (Denes et al.,
2020a) are fundamentally consistent with those provided by Illingworth
and Rodkin (2017), as presented in the Caltrans reports (Caltrans 2016,
2020). The spectra calculated by JASCO are low frequency (i.e., primary
acoustic energy occurs below approximately 1 kHz), with peaks around
the oscillation frequency of the vibratory hammer. This is
approximately the same finding as Illingworth and Rodkin (2017), which
showed that most of the primary acoustic energy occurs below
approximately 2 kHz. The calculated levels near the source exceed the
expected values of SPL 160-165 dB re 1 [micro]Pa measured at 10 m for
sheet pile driving in the Caltrans report (2016, 2020) and as cited in
NOAA's pile-driving worksheet tool (Caltrans 2012, 2015) (https://media.fisheries.noaa.gov/2021-02/SERO%20Pile%20Driving%20Noise%20Calculator_for%20web.xlsx?null). JASCO
estimates an SPL of 180 dB re 1 [micro]Pa at 31 m, and consequently a
range to 120 dB re 1[micro]Pa of approximately 36 km. JASCO recognized
this as an overestimate but considered it acceptable because the source
level measurements for vibratory driving of sheet piles cited in
Caltrans (2012, 2015) come from only a few examples, and were obtained
when setting the pile to a shallow depth before impact pile driving was
used to drive the sheet pile to full desired depth. Only vibratory
driving would be used for installation of sheet piles to construct the
cofferdam for the South Fork Wind project. It is likely that sheet
piles, and therefore the vibratory hammer, might encounter more
resistance as the desired installation depth is approached at the
cofferdam location compared to the examples included in the Caltrans
report (2016, 2020). This increased resistance would require an
increase in vibratory hammer energy, producing an elevated level of
sound propagating from the installation site. NMFS agrees with this
approach and, as such, no adjustments were made to the Level B
harassment zone (or Level A harassment zone) in the final IHA for
vibratory driving of sheet piles.
Comment 14: The Commission claims that NMFS assumed that vibratory
pile driving would occur on only two days, rather than a maximum of six
days (up to three days each for installation and removal) specified
elsewhere in the notice of the proposed IHA 86 FR 8490; February 5,
Response: This is an incorrect interpretation of the text. The
total installation and removal will take up to six days to complete.
Within that period, vibratory pile driving for the cofferdam is
expected to occur for 18 hours to install the sheet piles and 18 hours
to remove them, so a total of 2 days was used to estimate take. [86 FR
8490; February 5, 2021, p. 8533 states: Since NMFS expects that any
exposures would be brief (no more than 3 hours per day for impact pile
driving or 36 hours over 6 days for vibratory pile driving, and likely
less given probable avoidance response). 36 hours over 6 days=a maximum
of two 18-hour periods. p. 8521 states: Modeling of the Level A
harassment exposures resulting from two 18-hour periods of vibratory
pile driving and removal resulted in less than one exposure for all
species for each month between October 1 and May 31. p. 8508 states:
But the short-term duration (approximately 36 hours over 6 non-
consecutive days, 18 hours each for installation and removal). p. 8491
states: Installation and removal of the cofferdam are each expected to
take 1 to 3 days of vibratory pile driving.].
Comment 15: The Commission claims that NMFS did not increase the
estimated Level B harassment takes for vibratory pile driving to an
appropriate number, based on group size and frequency of occurrence in
the project, for fin whales, sei whales, humpback whales, Atlantic
white-sided dolphins, and common dolphins.
Response: Based on the best available scientific information and
the large Level B harassment zone, NMFS agrees and has increased the
number of takes by Level B harassment for humpback whales, and common
and Atlantic white-sided dolphins. NMFS reviewed reported group sizes
for each species (DoN 2017; Smultea Sciences, 2020; CSA 2921; AMAPPS
2021), selected the largest group size reported for humpback whales
(1.6; AMAPPS) and common dolphins (35; AMAPPS), multiplied group size
by the number of potential days on which vibratory pile driving could
occur (18 hours over 3 days for installation, 18 hours over 3 days for
removal, total of 6 days), and rounded to the nearest whole number.
This approach resulted in the following increases in Level B harassment
takes: Humpback whale (10) and common dolphins (210). Previous
monitoring efforts in or near the South Fork Wind Lease Area reported
that no Atlantic white-sided dolphins were sighted during surveys
(Smultea Sciences, 2020; CSA 2021). However, AMAPPS (2021) reported
sightings of Atlantic white-sided dolphins in the RI/MA WEA, with a
peak group size of 50 during the summer. Based on this group size, NMFS
has increased Level B harassment takes of Atlantic white-sided dolphins
from 1 to 50. Finally, the Commission also recommended increasing take,
by Level B harassment, of fin and sei whales incidental to vibratory
pile driving. Exposure modeling resulted in exposures for each of 10
months (October-May; Table 19) for all species potentially impacted by
vibratory pile driving. The amount of take proposed, by Level B
harassment, of fin whales was based on the month (April) with the
highest number of exposures (n=2). Of the remaining months, fin whale
exposure estimates were zero (November, December, January, and
February) and one (March and May). Given that the proposed amount of
take was already conservatively based on modeled exposures in April and
sightings of fin whales are generally more frequent in/near the Lease
Area as compared to along the ECR and nearshore HDD site (e.g., Smultea
Sciences, 2020), NMFS does not find that increasing take of fin whales,
by Level B harassment, is warranted. Exposure modeling resulted in zero
exposures of sei whales in all 10 months considered (Table 19). In
addition, sei whale sightings are extremely rare throughout the project
area, which agrees with the generally offshore pattern of sei whale
distribution (Hayes et al., 2021). Given the brief timeframe for
cofferdam installation/removal, the low likelihood of sei whale
occurrence in the project area during that brief timeframe, and the
lack of exposures resulting from exposure modeling, NMFS does not find
that increasing take of sei whales, by Level B harassment, is
Comment 16: The Commission notes that the input parameters
necessary to estimate the Level A harassment zones for construction
surveys using HRG equipment were not specified in the Federal Register
notice for the proposed IHA (86 FR 8490; February 5, 2021). In
addition, the Commission states that South Fork Wind specified
incorrect frequencies in Table 13 of the IHA application for each
functional hearing group's most sensitive frequency within the proposed
operating frequencies of all impulsive sources, citing the example that
South Fork Wind specified 1.5 kHz as the most sensitive frequency for
all functional hearing groups within the 0.4-5 kHz operating frequency
for the GeoMarine Geo-Source 400 tip sparker. The Commission states
that most sensitive frequencies are 1.7 kHz for low-frequency (LF)
cetaceans and 5 kHz for the other three functional hearing groups.
Response: NMFS recognizes that not all input parameters (e.g.,
Weighting Factor Adjustments, WFAs) required to estimate Level A
harassment zones were included in the notice for the proposed IHA;
however, these values were included in the IHA application, which was
available for review during the public comment period (please refer to
the IHA application for more details on input parameters). The
Commission notes that the frequencies in Table 13 of the application
were incorrectly specified, and NMFS agrees. However, when the correct
frequencies are applied, the resulting ranges to the Level A harassment
isopleths are significantly smaller than the 500-m shutdown zone for
NARWs and 100-m shutdown for all other species (excluding some
delphinid species for which shutdown is waived). Further, NMFS has
repeatedly indicated that the potential for Level A harassment from
marine site characterization surveys is not a realistic outcome
regardless of implementation of mitigation measures such as shut down
(see Take Calculation and Estimation section); therefore, identifying
inputs into any Level A harassment model is not necessary.
Comment 17: The Commission notes that the ranges to Level A
harassment isopleths in Table 12 of the notice of the proposed IHA (86
FR 8490, February 5, 2021) for high-frequency cetaceans are incorrect,
according to their calculations, by a margin of tenths of a meter for
all impulsive sources based on SELcum thresholds (ranges
were reported as zero in the notice of the proposed IHA, but should
have been reported as <1), by a margin of 1.9 m for the AA triple plate
S-boom based on SPLpeak (2.8 m versus 4.7 m, as indicated in
the notice of the proposed IHA), and by a margin of tens of meters for
the non-impulsive GeoPulse 5430 based on SELcum (97.7 m
versus 36.5 m as indicated in the notice of the proposed IHA), assuming
use of the User Spreadsheet and South Fork Wind's specified input
parameters.
Response: NMFS appreciates the Commission's detailed comments
regarding ranges to the Level A harassment isopleths for high-frequency
cetaceans. NMFS has corrected the text in the Take Calculation and
Estimation section to reflect that South Fork Wind estimated the range
to the Level A harassment isopleth based on SELcum for the
GeoPulse 5430 (36.5 m) following NMFS interim guidance (NMFS, 2019b),
which accounts for beamwidth, water depth, and absorption (rather than
using the User Spreadsheet). While there are minor inconsistencies
between values calculated by NMFS and the Commission for the other
ranges to the Level A harassment isopleths, the differences are
inconsequential given that NMFS neither anticipates nor authorizes
Level A harassment incidental to construction surveys. For the purposes
of the exposure analysis, it was conservatively assumed that sparkers
would be the dominant acoustic source for all survey days. Thus, the
range to the isopleth corresponding to the threshold for Level B
harassment for sparkers (141 m), which is larger than any modeled range
to the Level A harassment isopleth for any hearing group, was used as
the basis of the take calculation for all marine mammals.
Comment 18: The Commission seeks clarification regarding why the
exclusion zones for mid-frequency cetaceans (except sperm whales), and
phocids are different between Table 26 in the Federal Register notice
of the proposed IHA (86 FR 8490; February 5, 2021) and Table 2 of the
proposed authorization.
Response: The zones being referenced in Table 26 of the notice of
the proposed IHA are the Level A harassment zones for HRG survey
activities, which are based on the calculated ranges, whereas the zones
in Table 2 of the proposed authorization represent the clearance zones
to be implemented during surveys. These zones are consistent with the
clearance and shutdown zones listed in Table 26 of the notice of the
proposed IHA (100 m).
Comment 19: The Commission notes that the Level B harassment zones
for CHIRPS are inconsistent in Tables 12 and 26 of the Federal Register
Response: The Level B harassment zones for CHIRPS have been
corrected to 54 m in Table 28 of this notice.
Comment 20: The Commission recommends that NMFS publish a revised
Federal Register notice and draft authorization with another 30-day
comment period because it believes there were errors in the proposed
IHA notice that prevented the public from fully understanding NMFS'
proposed action and NMFS's preliminary findings are questionable given
these perceived errors.
Response: NMFS does not agree with the Commission assertions and
does not adopt the recommendation. Specifically, NMFS disagrees that
the information presented in association with the proposed IHA was
insufficient to make the relevant findings under the MMPA. What the
Commission claims are ``inconsistencies, omissions, errors, and
deficiencies'' are, for the most part, differences of opinion on how
available data should be applied to our analysis. For example, the
Commission states that installing 16 monopiles, with one pile installed
every other day, would take 31 rather than 30 days as specified in
South Fork Wind's application and the Federal Register notice. Neither
the IHA application nor the Federal Register notice state that
monopiles would actually be installed every other day. Animal exposure
modeling required a piling schedule within which to conduct animat
modeling; therefore, two construction schedules were considered, one in
which piles are installed every day and one in which piles are
installed every other day. It is likely that neither of these absolute
representative schedules will be adhered to during installation of the
monopiles (e.g., pile installation may occur on consecutive days if
conditions allow, or might be interrupted by days of inclement weather
or other mitigating circumstances, etc.). The 30-day timeframe for
monopile installation was proposed by South Fork Wind in the IHA
application and, therefore, included in the notice of the proposed IHA.
Regardless of the detailed schedule, up to 16 monopiles will be
installed, no more than one per day, over the course of the South Fork
Wind construction project.
As described in responses to comments 1 and 3, a majority of the
Commission's comments were centered around the recommendation to use a
different, but not necessarily more accurate, acoustic model (i.e.,
DCSM and associated spreadsheet tool, DCSiE (Heaney et al., 2020)).
NMFS does not agree that utilizing DCSM and the DCSiE spreadsheet tool
would provide more appropriate acoustic propagation distances because
the DCSM and DCSIE approach would include a simpler model of
propagation (with limitations beyond 5 km from the acoustic source)
that approximates some aspects of environmental interaction (namely
absorption). NMFS believes that the well-tested, range-dependent
propagation models based on solutions to the wave equation used by
JASCO (described in Denes et al., 2020a) are more appropriate. Where we
did agree that there was an error or that the Commission's logic was
more appropriate to implement, we have made the recommended changes.
However, the recommendations by the Commission we did adopt were
predominately to either provide additional clarification or detail and
do not provide additional conservation
value or meaningfully influence any of the analyses underlying the
necessary findings. NMFS strongly disagrees with the Commission's
suggestion that NMFS' negligible impact and least practicable adverse
impact determinations may be invalid, and we note that the Commission
does not provide any information supporting this comment, whether NMFS
retained the take numbers and mitigation requirements from the proposed
IHA or adopted those recommended by the Commission. Since publication
of the proposed IHA, NMFS included additional monitoring and mitigation
measures, including multiple additions to the vessel strike avoidance
requirements. In addition, the Federal Register notice for issuance of
the final IHA includes installation of a casing pipe as an alternative
to a cofferdam. Given the shorter installation time and fewer number of
piles, potential impacts associated with installation of a casing pipe
are anticipated to be equal to or less than those associated with
installation of the cofferdam. Overall, these changes are not
sufficient to lead NMFS to reach any other conclusions regarding the
impact to marine mammals. For these reasons, NMFS is not republishing a
notice of proposed IHA.
Comment 21: The Commission states that NMFS must provide consistent
and informed guidance to the numerous industry operators that have
submitted or soon will submit incidental take authorization
applications for wind energy surveying, siting, and construction
Response: NMFS appreciates the Commission recommendation and will
consider developing broader/general guidance that allows for proper and
consistent mitigation and monitoring during various stages of offshore
wind development. NMFS will continue to prioritize pre-application
engagement with applicants seeking incidental take authorizations.
Comment 22: The Commission recommended that NMFS consider whether,
in situations involving marine site characterization surveys using HRG
equipment, IHAs are necessary. The Commission makes reference to
comments on previously proposed IHAs for marine site characterization
surveys, in which the Commission states that the small size of the
Level B harassment zones, the various shutdown requirements, and BOEM's
lease-stipulated requirements support the claim that NMFS should
consider the Commission's recommendation. In addition, the Commission
recommended that NMFS should evaluate whether take needs to be
authorized for those sources that are not considered de minimis,
including sparkers, and for which implementation of the various
mitigation measures should be sufficient to avoid Level B harassment
takes.
Response: NMFS thanks the Commission for its recommendation.
However, as NMFS has noted previously to comments (e.g., 85 FR 60424;
September 25, 2020), NMFS has evaluated whether taking needs to be
including sparkers and boomers, factoring into consideration the
effectiveness of mitigation and monitoring measures, and we have
determined that implementation of mitigation and monitoring measures
cannot ensure that all take can be avoided during all marine site
characterization survey activities under all circumstances at this
time. If and when we are able to reach such a conclusion, we will re-
evaluate our determination that an incidental take authorization is
warranted for these activities.
Comment 23: The ENGOs recommended that NMFS reduce the number of
Level A harassment takes for large whales to as close to zero as
possible and ensure zero Level A harassment takes of NARWs. The ENGOs
feel that the number of individuals projected to experience permanent
threshold shift (PTS), including humpback, minke, and endangered fin
whales, is relatively high for a project comprising only 15 turbines.
Response: South Fork Wind has not requested, nor has NMFS
authorized, incidental take by Level A harassment of NARWs. The
mitigation and monitoring measures included in the IHA help ensure this
level of harassment does not occur. The estimated Level A harassment
exposures for humpback, minke, and endangered fin whales resulting from
animal movement modeling are conservatively based on the maximum design
scenario including one difficult-to-drive pile, the maximum densities
across the proposed construction months, and a 24-hour accumulation
period. This sophisticated model produces a reliable, but conservative,
estimate of how many marine mammals may experience PTS incidental to
the project. Although modeling does take into account the seasonal
moratorium on impact pile driving of monopiles, it does not account for
any additional mitigation. In addition, the proposed Level A harassment
(in the form of PTS) take numbers, which are based on animal movement
modeling, do not fully account for the likelihood that whales will
avoid a stimulus (i.e., aversion) when possible before the individual
accumulates enough acoustic energy to potentially cause auditory
injury. Any adjustments to the model considering mitigation or
avoidance behavior are uncertain; therefore, to be conservative, NMFS
is authorizing the amount of take, by Level A harassment (PTS),
predicted by the model. 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. Even absent mitigation, no
serious injury or mortality from construction activities is
anticipated.
Comment 24: The ENGOs recommended that NMFS require the seasonal
prohibition on impact pile driving to be effective from December 1
through April 30.
Response: Since publication of the proposed IHA, South Fork Wind
communicated to NMFS that construction activities will not commence
until November 2022, rather than between April and May 2022 (as
indicated in the proposed IHA). Therefore, the period of effectiveness
of the IHA is November 15, 2022, to November 14, 2023. In the final
IHA, NMFS is requiring a seasonal restriction on impact pile driving of
monopiles from December 1 through April 30, unless unanticipated delays
due to weather or technical problems, notified to and approved by the
Bureau of Ocean Energy Management (BOEM), arise that necessitate
extending impact pile driving of monopiles into December. South Fork
Wind's revised project schedule includes, as the first construction
activity during the period of effectiveness of the IHA, installation of
a cofferdam or casing pipe where the export cable conduit exits from
the seabed to contain drilling returns and prevent the excavated
sediments from silting back into the Horizontal Directional Drill (HDD)
exit pit. Based on the seasonal restriction on monopile installation
and South Fork Wind's revised construction schedule, monopile
installation would not begin until May 2023. Therefore, the timeframe
in which South Fork Wind would install monopiles is limited to May 1,
2023, through November 14, 2023.
Comment 25: The ENGOs recommended that NMFS take measures to
minimize Level B harassment exposure of NARWs to noise from pile
driving beyond the 5,000-m clearance
zone by requiring stringent noise reduction and attenuation devices.
Response: While the clearance zone (using a combination of visual
and acoustic observation) for NARWs is 5,000 m, NMFS is including
measures to minimize exposure beyond that zone. For example, any
observation of a NARW at any distance by PSOs on the pile-driving
platform or dedicated PSO vessel will trigger a delay in impact pile
driving. Because PSOs on the pile-driving platform will be equipped
with enhanced vision capabilities (e.g., big eye binoculars), it may
well be that NARWs are observed beyond 5,000 m on days with good
visibility conditions. The final IHA clarifies that the minimum
visibility zone to begin pile driving is 2,200 m and that PAM PSOs must
confirm that there have been no PAM detections of NARWs out to 5,000 m
prior to commencing pile driving (during the clearance period). The IHA
does require noise reduction such that the model results, assuming 10-
dB attenuation, are not exceeded. If acoustic monitoring reveals
greater than anticipated zone sizes, the IHA requires South Fork Wind
to take additional noise mitigation measures to prevent further
exceedance of the modeled zones. If all measures are exhausted and
monitoring reveals South Fork Wind was not successful in meeting the
modeled zones, harassment, minimum visibility, and shutdown zones will
be expanded and monitoring enhanced.
Comment 26: The ENGOs recommended that if a NARW is visually or
acoustically detected within the 5,000-m clearance zone, or visually
detected at any distance from the pile at any time, that pile driving
be shutdown, unless continued pile-driving activities are necessary for
reasons of human safety or installation feasibility. In addition, they
suggest that NMFS should consider expanding these same protections to
other endangered species, as well as those currently experiencing a UME
that are in the same functional hearing group as the NARW.
Response: NMFS agrees with the ENGOs that impact pile driving
should be delayed or shutdown, if already initiated, if a NARW is
sighted at any distance from the pile and, thus, NMFS included those
conditions in the proposed IHA and has carried them over to the final
authorization as well. South Fork Wind is required to delay pile
driving if a NARW call is localized to a position within the 5,000-m
clearance zone and, if pile driving has already commenced, South Fork
Wind must shutdown pile driving if a NARW call is localized to a
position within the 2,000-m PAM shutdown zone. NMFS has determined that
the combination of a PAM shutdown zone that is larger than the Level A
harassment zone for NARWs (1,621 m) and the requirement to shutdown if
a NARW is sighted at any distance are sufficiently protective to
prevent Level A harassment.
The ENGOs suggested that NMFS should also require a 5,000-m
shutdown zone during monopile installation if other endangered species
(i.e., fin and sei whales) as well as those currently experiencing a
UME (i.e., humpback and minke whales), are detected visually or
acoustically within the 5,000-m clearance zone specific to NARWs. NMFS
is not authorizing any take by Level A harassment (i.e., PTS) for
NARWs; therefore, the shutdown requirements when a NARW is detected
(visually or acoustically) must afford the greatest practicable
protection to avoid any Level A harassment. NMFS is authorizing take by
Level A harassment of fin, sei, and minke whales (one take for each
species), although both the clearance (2,200 m) and shutdown zones
(2,000 m) are hundreds of meters larger than the exposure-based modeled
ranges to the Level A harassment isopleths for these species. Animal
movement modeling resulted in the Level A harassment exposure of one
fin whale and one minke whale; however, animal movement modeling does
not account for mitigation measures or potential avoidance behavior
and, as mentioned above, the shutdown zone is larger than the ranges to
the Level A harassment isopleths for both fin (1,756 m) and minke
whales (1,571 m). Although animal movement modeling resulted in zero
Level A exposures of sei whales, South Fork Wind requested and NMFS is
authorizing take, by Level A harassment, of one sei whale based on (1)
rare observations of singleton sei whales in the Lease Area during
previous monitoring effects (Kenney and Vigness-R,aposa, 2010; Smultea
Sciences, 2020; AMAPPS 2021), and (2) difficulty distinguishing fin and
sei whales at sea (observers sometimes report a sei/fin whale complex).
NMFS is authorizing take, by Level A harassment, of 4 humpback whales
based on the results of animal movement modeling, and the possibility
that humpback whales might remain in the area between the shutdown zone
(2,000 m) and the furthest extent of the Level A harassment zone (3,642
m), (assuming 10-dB attenuation) for a long enough timeframe to incur
If any large whale (including NARWs) enters the Level B harassment
zone undetected or if visibility conditions limit visual monitoring to
the minimum visibility zone, it is possible that individuals might be
exposed to impact pile-driving noise sufficient to cause behavioral
effects rising to the level of take under the MMPA. NMFS expects those
effects would be temporary in nature and unlikely to cause any
perceptible longer-term consequences to individuals or populations.
While NMFS analyzed Level A harassment exposures as requested by
South Fork Wind and authorized them as appropriate, NMFS finds that
such exposures are unlikely given (1) the short duration of monopile
installation (2-4 hours), (2) the fact that authorized take numbers do
not account for mitigation measures, and (3) the potential for a
whale's averse behavior in response to impact pile driving. Level B
harassment of some smaller number of individuals as a subset of the
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. Accordingly, NMFS
does not find it warranted to require shutdown if a fin, sei, humpback,
or minke whale is detected between 2,000 m and 5,000 m of the pile.
Comment 27: The ENGOs stated that NMFS should provide more detail
(both a written description and diagram of potential ``blind spots''
during monitoring) on how the secondary vessel will be deployed during
the 60-minute clearance period (e.g., vessel speed, configuration of
PSOs on the vessel, etc.) to monitor the entire clearance zones as well
as the 3,642-m Level A harassment zone for humpback whales and, if it
is not possible to provide full coverage of the clearance zone for the
full 60-minute period, the ENGOs recommended that NMFS require
additional monitoring vessels and PSOs.
Response: South Fork Wind is required to visually monitor a minimum
clearance zone with a 2.2-km radius from the pile-driving vessel, and
to use a combination of visual and acoustic methods to ensure that a 5-
km radius clearance zone is clear of NARWs prior to initiating pile
driving. Further, on days when PSOs are able to observe beyond 5 km,
any detection of a NARW by PSOs on the pile-driving and/or dedicated
PSO vessels, regardless of distance, would trigger a delay in pile
driving. Each of the two PSOs deployed on the pile-driving vessel will
be responsible for visually surveying 180 degrees (for a total of 360
degrees) out to a minimum of 2.2 km from the pile-driving vessel, the
minimum visibility requirement for clearance to occur, thereby
providing total visual coverage
of the large whale clearance zone without any potential ``blind
spots.'' The PSOs on the pile-driving vessel will likely be positioned
at a higher elevation above the waterline than the PSOs on the
dedicated PSO vessel and will, therefore, have a range of vision well
beyond 2.2 km on days with good visibility. The two additional PSOs
deployed on the dedicated PSO vessel, surveying at a radius of 2.2 km
from the pile-driving vessel, are expected to be positioned at an
elevation above the waterline similar to PSOs on HRG vessels used in
marine site characterization surveys. Each of these PSOs will also be
responsible for surveying 180 degrees, with one PSO providing visual
coverage between the dedicated PSO vessel and the pile-driving vessel
(the 2.2-km clearance zone), and the second PSO visual monitoring the
area beyond the 2.2-km clearance zone. Visibility conditions may, at
times, prevent 100-percent visual coverage of the humpback Level A
harassment zone beyond 2.2 km from the piling vessel; therefore NMFS is
authorizing 4 takes, by Level A harassment, of humpback whales.
PSOs on board the pile-driving and dedicated PSO vessels will
coordinate to the extent practicable to visually cover discrete zones
while monitoring. The dedicated PSO vessel will travel at a maximum
speed of 10 kts, allowing it to make a complete trip around the piling
vessel at a distance of 2.2 km in one hour or less. The use of a real-
time data collection platform, including the software program
Mysticetus, will allow PSOs on the pile-driving vessel to see
detections made by PSOs on the dedicated PSO vessel, and vice versa.
Comment 28: The ENGOs recommended that all project-associated
vessels should adhere to a 10-kt speed restriction at all times, except
in circumstances where the best available scientific information
demonstrates that whales do not use a particular area within the
overall project area.
Response: South Fork Wind is required to operate all vessels at 10
kts or less when overlapping with a DMA and in any designated SMA.
Further, if a vessel is operating faster than 10 kts, a dedicated
observer is required to be onboard that vessel. While NMFS acknowledges
that vessel strikes can result in injury or mortality, and that risk of
vessel strike increases with speed, NMFS has analyzed the potential for
ship strike resulting from South Fork Wind's activity and has
determined that, based on the number and frequency of vessels South
Fork Wind will be operating and the required mitigation measures
specific to vessel strike avoidance included in the IHA, the potential
for vessel strike is so low as to be discountable. These mitigation
measures, most of which were included in the proposed IHA and all of
which are required in the final IHA, include, but are not limited to
the following requirements: (1) All vessel operators must comply with
10-kt (18.5 km/hour) or less speed restriction in any SMA while
underway, (2) in the event that a DMA is established that overlaps with
an area where a project-associated vessel would operate, that vessel,
regardless of size, will transit that area at 10 kts (18.5 km/hour) or
less, and (3) vessels of all sizes must operate port to port at 10 kts
(18.5 km/hour) or less between November 1 and April 30, except while
transiting inside Narragansett Bay or Long Island Sound. NMFS has
determined that the ship strike avoidance measures in the IHA are
sufficient to ensure the least practicable adverse impact on species or
stocks and their habitat. Furthermore, NMFS is not aware of any
documented vessel strikes involving vessels associated with offshore
wind development, including vessels used for marine site
characterization surveys (for which IHAs were issued by NMFS) during
the survey activities themselves or while transiting to and from
project sites.
Comment 29: The ENGOs recommended that NMFS require South Fork Wind
to use the best commercially feasible technology and methods to
minimize sound levels from pile driving. Specifically, they stated that
NMFS should require a combination of noise mitigation systems to (1)
obtain the greatest noise reduction and attenuation using technically
and commercially feasible measures considering factors such as project
design and seabed conditions, and (2) achieve no less than 10-dB SEL in
combined noise reduction and attenuation, taking as a baseline,
projections from prior noise measurements of unmitigated piles from
Europe and North America.
Response: NMFS agrees with the ENGOs recommendation that South Fork
Wind should use the best available technology to reduce acoustic
impacts to marine mammals incidental to impact pile driving of
monopiles. In the IHA application, South Fork Wind proposed to use a
single BBC to attenuate noise produced during monopile installation.
However, the final IHA requires that South Fork Wind use either a
single BBC coupled with an additional noise mitigation device (e.g.,
Hydro Sound Damper), or a dBBC to achieve measured ranges to the Level
A harassment and Level B harassment isopleths that are equal to or less
than those predicted by acoustic modeling, assuming 10-dB attenuation.
NMFS has determined that this mitigation measure will help to ensure
that take of marine mammals, including NARWs, is reduced to the level
of least practicable adverse impact.
Comment 30: The ENGOs recommended that NMFS should require South
Fork Wind to report all visual observations and acoustic detections of
NARWs to NMFS or the Coast Guard as soon as possible and no later than
the end of the PSO shift, and that South Fork Wind should also be
required to immediately report an entangled or dead NARW to NMFS, the
Marine Animal Response Team (1-800-900-3622) or the United States Coast
Guard via one of several available systems (e.g., phone, app, radio).
Response: NMFS agrees with the recommendation that NARW detections,
both visual and acoustic, should be reported as soon as possible. The
IHA requires that if a NARW is observed at any time by PSOs or
personnel on any project vessels, during any project-related activity
or during vessel transit, South Fork Wind must report sighting
information to the NMFS NARW Sighting Advisory System, the U.S. Coast
Guard via channel 16, and the WhaleAlert app as soon as feasible but no
longer than 24 hours after the sighting. We anticipate that most
sightings will be reported by the end of the PSO shift as recommended
by the ENGOs; however, we also recognize that communications at sea can
sometimes be interrupted (e.g., poor cellular or satellite service).
Therefore, we are allowing the 24-hour maximum delay in reporting a
sighting(s) (with the caveat they report a sighting as soon as
feasible). If a NARW is detected via PAM, a report of the detection
must be submitted to NMFS as soon as is feasible, but no longer than 24
hours after the detection. In addition, within 48 hours, metadata
associated with the detection(s) must be submitted to the Northeast
Passive Acoustic Reporting System ([email protected]). We note
that given the gravity of a situation associated with the unauthorized
take by ship strike, the IHA requires South Fork Wind to report any
such taking to NMFS immediately, dedicating all resources to ensure
that the incident is reported. Such dedication, including ceasing
activities (as required if a ship strike occurs) is not necessary for a
sighting or acoustic detection report. See the Mitigation section below
for details. In addition, NMFS agrees with the recommendation that
Wind should be required to immediately report a dead or entangled whale
to NMFS, a Marine Animal Response Team, and the USCG, and has included
this requirement in the final authorization.
Comment 31: The ENGOs and a commenter from the general public
recommended that NMFS incorporate additional data sources into
calculations of marine mammal density and take estimates. Similarly,
RODA stated the NMFS' analyses should rely on the best available data
for estimating marine mammal take and developing robust mitigation
measures, and that the impacts to NARWs be fully considered prior to
the issuance of the IHA.
Response: Habitat-based density models produced by the Duke
University Marine Geospatial Ecology Lab (MGEL; Roberts et al., 2016,
2017, 2018, 2020) represent the best available scientific information
concerning marine mammal occurrence within the U.S. Atlantic Ocean
(more information, including the model results and supplementary
information for each of those models, is available at https://seamap.env.duke.edu/models/Duke/ EC/). Density models were originally
developed for all cetacean taxa in the U.S. Atlantic (Roberts et al.,
2016). These models provided key improvements over previously available
information, by (1) incorporating additional aerial and shipboard
survey data from NMFS and other organizations collected over the period
1992-2014, (2) incorporating data from 60-percent more shipboard and
500-percent more aerial survey hours than did previously available
models, (3) controlling for the influence of sea state, group size,
availability bias, and perception bias on the probability of making a
sighting, and (4) modeling density from an expanded set of 8
physiographic and 16 dynamic oceanographic and biological covariates.
In subsequent years, certain models have been updated on the basis of
availability of additional data as well as methodological improvements.
In addition, a new density model for seals was produced as part of the
2017-18 round of model updates. Of particular note, Roberts (2020)
further updated density model results for NARWs by incorporating
additional sighting data and implementing three major changes:
Increasing spatial resolution, generating monthly estimates based on
three periods of survey data, and dividing the study area into 5
discrete regions. Model Version 9 for NARWs was undertaken with the
following objectives (Roberts 2020): (1) To account for recent changes
to NARW distributions, the model should be based on survey data that
extend through 2018, or later if possible. In addition to updates from
existing collaborators, data should be solicited from two survey
programs not used in prior model versions, including aerial surveys of
an area overlapping the Massachusetts (MA) and RI/MA WEAs from 2011-
2015 led by New England Aquarium (Kraus et al., 2016), and continued
from 2017-2018, and recent surveys of New York waters, either
traditional aerial surveys initiated by the New York State Department
of Environmental Conservation in 2017, or digital aerial surveys
initiated by the New York State Energy Research and Development
Authority in 2016, or both; (2) to reflect a view in the NARW research
community that spatiotemporal patterns in NARW density changed around
the time the species entered a decline in approximately 2010, consider
basing the new model only on recent years, including contrasting
``before'' and ``after'' models that might illustrate shifts in
density, as well as a model spanning both periods, and specifically
consider which model would best represent NARW density in the near
future; (3) to facilitate better application of the model to near-shore
management questions, extend the spatial extent of the model farther
in-shore, particularly north of New York; and (4) increase the
resolution of the model beyond 10 km, if possible. All of these
objectives were met in developing the Version 9 update to the NARW
density model.
Accordingly, NMFS has determined that the Roberts et al. suite of
density models represent the best available scientific information, and
this determination was incorporated into NMFS' analysis for this IHA.
NMFS' reliance on the best available scientific evidence in our
analysis of potential impacts of the project on marine mammals and the
development of take estimates further includes recent survey data. For
example, where marine mammal sighting data collected by PSOs during
marine site characterization surveys in or near the project area
indicated that the potential for take may be higher than indicated by
the modeled exposures, we adjusted take numbers accordingly, when
appropriate. For NARWs, exposure modeling was based on the most recent
density data (Roberts 2020), which, as described above, incorporated
more recent survey data (through 2018) and that for the first time
included data from the 2011-2015 surveys of the MA and RI/MA WEAs
(Kraus et al. 2016) as well as the 2017-2018 continuation of those
surveys, known as the Marine Mammal Surveys of the Wind Energy Areas
(MMS-WEA) (Quintana et al., 2018). In addition, Pace (2021) describes
that the stock abundance of NARW is lower than that considered when the
proposed IHA was published; we have evaluated that new information and
incorporated it into the final IHA. In developing the final IHA, NMFS
also consulted the NARW sighting database, WhaleMap, which aggregates
both visual and acoustic sighting information from 2010 to present day.
Contributors to the database include the Department of Fisheries and
Oceans Canada, Transport Canada, NOAA's Protected Species Branch, Woods
Hole Oceanographic Institution/robots4whales, New England Aquarium,
Center for Coastal Studies, Canadian Whale Institute, Mingan Island
Cetacean Study, Ocean Tracking Network, Dalhousie University,
University of New Brunswick, and Nick Hawkins Photography, making it an
extensive database and useful tool in identifying spatial and temporal
occurrence of whales as well as locations and timing of management
actions such as implementation of DMAs.
NMFS invests heavily in conserving NARWs and, in analyzing the
impacts to NARWs from project construction, has considered and
leveraged the wealth of data collected by NOAA and partners to make
appropriately conservative management decisions in consideration of our
statutory authority under the MMPA. NMFS has applied the best available
(and most recent) science and has made the determinations necessary to
issue this IHA.
For future IHAs, NMFS will continue to review other recommended
data sources that become available to evaluate their applicability in a
quantitative sense (e.g., to an estimate of take numbers) and,
separately, to ensure that relevant information is considered
qualitatively when assessing the impacts of the specified activity on
the affected species or stocks and their habitat. NMFS will continue to
use the best available scientific information, and we welcome future
input from interested parties on data sources that may be of use in
analyzing the potential presence and movement patterns of marine
mammals, including NARWs, in U.S. Atlantic waters.
Comment 32: The ENGOs recommended that NMFS should acknowledge the
potential for take from vessel strikes and vessel noise. RODA similarly
expressed concern that the vessel traffic associated with construction
and operation of offshore wind farms may increase the risk of ship
strike of NARWs, and suggests that
NMFS should focus restrictions on increases in vessel traffic rather
than vessel speed restrictions alone. In addition, RODA stated that
increased vessel travel might contribute to elevated noise levels that
will disrupt NARW behavior.
Response: South Fork Wind did not request authorization for take
incidental to vessel strike during construction of South Fork Wind
Farm. Nevertheless, as mentioned in the response to a previous comment,
NMFS analyzed the potential for vessel strikes to occur during the
construction phase of the project, and determined that the potential
for vessel strike is so low as to be discountable. NMFS does not
authorize any take of marine mammals incidental to vessel strike
resulting from the construction phase of the project. If South Fork
Wind strikes a marine mammal with a vessel, it would be in violation of
the MMPA. This gives South Fork Wind a strong incentive to operate its
vessels with all due caution and to effectively implement the suite of
vessel strike avoidance measures called for in the IHA. South Fork Wind
proposed a very conservative suite of mitigation measures related to
vessel strike avoidance, including measures specifically designed to
avoid impacts to NARWs. Section 4(d) in the IHA contains a suite of
non-discretionary requirements pertaining to ship strike avoidance,
including vessel operation protocols and monitoring. Since publication
of the proposed IHA, NMFS included several new vessel strike avoidance
measures that further reduce the likelihood of take incidental to
vessel strike (see Changes from Proposed IHA to Final IHA).
Construction of the project will likely be based out of ProvPort, RI or
Port of New London, CT, both of which require a 50-60 mile one-way trip
by vessel to the Lease Area. South Fork Wind has indicated that during
construction, the number of crew transfer vessel transits will be
limited to 20 per month. To date, NMFS is not aware of any wind
industry vessel (e.g., marine site characterization survey vessel)
reporting a ship strike. When considered in the context of the low
overall probability of any vessel strike by South Fork Wind vessels,
given the limited additional project-related vessel traffic relative to
existing traffic in the project area, the comprehensive visual and PAM
monitoring required in transit routes, and that construction would
occur during the time of year when NARW density is lowest, NMFS
believes these measures are sufficiently protective to avoid ship
strike; thus, we did not authorize take from ship strike. These
measures are described fully in the Mitigation section below, and
include, but are not limited to: training for all vessel observers and
captains, daily monitoring of the NARW Sighting Advisory System,
WhaleAlert app, and USCG Channel 16 for situational awareness regarding
NARW presence in the project area (including transit corridors),
communication protocols if whales are observed by any South Fork Wind
personnel, vessel operational protocols should any marine mammal be
observed, and visual and passive acoustic monitoring to clear transit
routes of NARWs.
The potential impacts of overall increases in the amount of vessel
traffic related to OSW development, which is separate from the analysis
of the potential for vessel strike during South Fork Wind's
construction phase under the final authorization, were addressed in
BOEM's EIS for the South Fork Wind project, which can be found here:
https://www.boem.gov/renewable-energy/state-activities/south-fork. In
summary, BOEM determined that it is likely that mobile marine mammals
would avoid behavioral disturbance from exposures like those resulting
from vessel noise, meaning that the duration of exposure to noise from
slow-moving, or closely clustered and stationary construction vessels
would be limited. Moreover, a substantial portion of construction
vessel activity would occur in an area having high existing levels of
vessel traffic. In these areas, construction vessel noise would
contribute to, but may not substantially alter, ambient noise generated
by existing large vessel traffic in the vicinity.
As described above, South Fork Wind estimates that 20 crew transfer
vessel transits per month will be required. While some individual
marine mammals may exhibit short-term behavioral responses, and given
the possibility that elevated background noise from vessels and other
sources could interfere with the detection or interpretation of
acoustic cues among NARW conspecifics, brief exposures to one or two
South Fork Wind vessels transporting crew between the Lease Area and a
nearby port would be unlikely to disrupt behavioral patterns in a
manner that would rise to the level of take.
recommended that NMFS analyze cumulative impacts to NARWs and other
endangered and protected marine mammals species and stocks as part of
the take estimation and permitting process, and suggest that NMFS
advance a programmatic incidental take regulation for offshore wind
development activities that takes into account risks from other
sectors.
Response: The ENGOs conflate the requirements of the MMPA and NEPA
in their contention that NMFS must analyze the cumulative impacts from
multiple proposed wind development activities on NARWs and other
endangered and protected species and stocks, and that appropriate
mitigation must be prescribed to mitigate those cumulative impacts.
Neither the MMPA nor NMFS' codified implementing regulations
specifically call for consideration of impacts on marine mammals and
their habitat from activities other than those specified in the request
for authorization. The preamble for NMFS' implementing regulations (54
FR 40338; September 29, 1989) states in response to comments that the
impacts from other past and ongoing anthropogenic activities are to be
incorporated into the negligible impact analysis via their impacts on
the baseline. Consistent with that direction, NMFS has factored into
its negligible impact analysis the impacts of other past and ongoing
anthropogenic activities via their impacts on the baseline (e.g., as
reflected in the density/distribution and status of the species,
population size and growth rate, and other relevant stressors). Section
101(a)(5)(D) of the MMPA requires NMFS to modify, suspend, or revoke
the IHA if it finds that the activity is having more than a negligible
impact on the affected species or stocks of marine mammals. NMFS will
closely monitor baseline conditions before and during the period when
the IHA is effective and will exercise this authority if appropriate.
Section 101(a)(5)(D) of the MMPA requires NMFS to make a determination
that the take incidental to a ``specified activity,'' as opposed to
other activities not specified in the request for an IHA, will have a
negligible impact on the affected species or stocks of marine mammals.
NMFS' implementing regulations require applicants to include in their
request a detailed description of the specified activity or class of
activities that can be expected to result in incidental taking of
marine mammals. 50 CFR 216.104(a)(1). Thus, the ``specified activity''
for which incidental take coverage is being sought under section
101(a)(5)(D) is generally defined and described by the applicant. Here,
South Fork Wind was the applicant for the IHA, and NMFS is responding
to the specified activity as described in their application (and
making the necessary findings on that basis). Through the response to
public comments in the 1989 implementing regulations, we also indicated
(1) that NMFS would consider cumulative effects that are reasonably
foreseeable when preparing a NEPA analysis and (2) that reasonably
foreseeable cumulative effects would also be considered through the
section 7 consultation for ESA-listed species. In this case, cumulative
impacts have been adequately addressed under NEPA in BOEM's
Environmental Impact Statement regarding South Fork Wind's proposed
project. NMFS is a cooperating agency under NEPA on that EIS and has
adopted the Final Environmental Impact Statement (FEIS) for purposes of
issuing the IHA to South Fork Wind. In addition, NMFS was a signatory
to the associated Record of Decision issued on November 24, 2021.
Separately, NMFS engaged in intra-agency consultation under section 7
of the ESA. The resulting Biological Opinion, issued October 1, 2021,
determined that NMFS' action of issuing the IHA is not likely to
adversely affect listed marine mammals or adversely modify their
critical habitat. The Biological Opinion considered activities both
within (related to construction) and outside (e.g., operation and
decommissioning) the scope of NMFS' IHA and included Terms and
Conditions aimed at reducing the potential impacts of the project on
marine mammals, including NARWs.
With respect to the recommendation that NMFS advance programmatic
incidental take regulations for offshore wind development that take
into account risks from other sectors, NMFS may issue regulations upon
request. To date, neither the offshore wind industry nor BOEM has
expressed interest in applying for such regulations. We note that the
footnote the ENGOs provided in the letter including this comment cites
the request to BOEM for a programmatic EIS. Again, it appears the ENGOs
are conflating the NEPA and MMPA processes. NMFS does agree with the
ENGOs that consistency in mitigation measures, where appropriate,
provides efficiencies and helps to ensure adequate measures are being
prescribed. To this end, NMFS is working on developing best management
practice guidelines that will assist NMFS in developing mitigation
measures common to all offshore wind IHAs.
Comment 34: The ENGOs recommended that NMFS avoid describing
potential changes resulting from offshore wind development as
``beneficial,'' as it is unclear what implications these changes may
have on the wider ecosystem, and instead use terminology such as
``increase,'' ``decrease,'' and ``change.''
Response: In the proposed IHA notice, NMFS identified that impacts
from the permanent structures (i.e., WTGs and OSS) on marine mammal
habitat may be beneficial as a result of increased presence of prey due
to the WTGs (and OSS) potentially acting as artificial reefs (Russell
et al., 2014). However, we recognize that the long-term impact from
foundation presence is outside the scope of the effective period of the
IHA and that this analysis is more appropriate in the context of the
ESA consultation and NEPA analysis as it relates to marine mammal
habitat. We agree that the long-term ecosystem effects from offshore
wind development in the Northwest Atlantic are still being evaluated
and that those ecosystem effects are likely to be complex. Thus, while
we acknowledge that there is currently insufficient information to draw
a conclusion regarding longer-term impacts to marine mammals, we agree
with the commenters that the term ``beneficial'' should be avoided when
describing potential outcomes of offshore wind development for marine
mammals.
Comment 35: The ENGOs recommended that NMFS prohibit extensions of
any 1-year authorizations through a truncated 15-day comment period as
it is contrary to the MMPA. A member of the general public echoed this
concern and suggested that there is not adequate time in the review
process to comment on the proposed IHA or any potential renewal IHA.
Response: NMFS did not include language in the final IHA for the
South Fork Wind project related to renewal. While this does not
necessarily preclude a Renewal IHA, we think a Renewal IHA is unlikely
in this case, given the potential for changes over the next three years
that could affect our analyses. However, NMFS' IHA renewal process
meets all statutory requirements. In prior responses to comments about
IHA renewals (e.g., 84 FR 52464; October 02, 2019 and 85 FR 53342,
August 28, 2020), NMFS has explained how the renewal process, as
implemented, is consistent with the statutory requirements contained in
section 101(a)(5)(D) of the MMPA, provides additional efficiencies
beyond the use of abbreviated notices and, further, promotes NMFS'
goals of improving conservation of marine mammals and increasing
efficiency in the MMPA compliance process. Therefore, we intend to
continue implementing the renewal process. The notice of the proposed
IHA published in the Federal Register on February 5, 2021 (86 FR 8490)
made clear that the agency was seeking comment on both the initial
proposed IHA and the potential issuance of a renewal for this project.
Because any renewal is limited to another year of identical or nearly
identical activities in the same location or the same activities that
were not completed within the 1-year period of the initial IHA,
reviewers have the information needed to effectively comment on both
the immediate proposed IHA and a possible 1-year renewal, should the
IHA holder choose to request one. While there would be additional
documents submitted with a renewal request, for a qualifying renewal
these would be limited to documentation that NMFS would make available
and use to verify that the activities are identical to those in the
initial IHA, are nearly identical such that the changes would have
either no effect on impacts to marine mammals or decrease those
impacts, or are a subset of activities already analyzed and authorized
but not completed under the initial IHA. NMFS would also need to
confirm, among other things, that the activities would occur in the
same location; involve the same species and stocks; provide for
continuation of the same mitigation, monitoring, and reporting
requirements; and that no new information has been received that would
alter the prior analysis. The renewal request would also contain a
preliminary monitoring report in order to verify that effects from the
activities do not indicate impacts of a scale or nature not previously
analyzed. The additional 15-day public comment period provides the
public an opportunity to review these few documents, provide any
additional pertinent information, and comment on whether they think the
criteria for a renewal have been met. Between the initial 30-day
comment period on these same activities and the additional 15 days, the
total comment period for a renewal is 45 days.
In addition to the IHA renewal process being consistent with all
requirements under section 101(a)(5)(D), it is also consistent with
Congress' intent for issuance of IHAs to the extent reflected in
statements in the legislative history of the MMPA. Through the
provision for renewals in the regulations, description of the process
and express invitation to comment on specific potential renewals in the
Request for Public Comments section of each proposed IHA, the
description of the process on NMFS' website, further elaboration on the
process through
responses to comments such as these, posting of substantive documents
on the agency's website, and provision of 30 or 45 days for public
review and comment on all proposed initial IHAs and Renewals
respectively, NMFS has ensured that the public is ``invited and
encouraged to participate fully in the agency's decision-making
process'' as Congress intended.
Comment 36: The ENGOs recommended that NMFS work with relevant
experts and stakeholders towards developing a robust and effective near
real-time monitoring and mitigation system for NARWs and other
endangered and protected species (e.g., fin, sei, minke, and humpback
whales) during offshore wind development.
Response: NMFS is generally supportive of this concept. A network
of near real-time baleen whale monitoring devices are active or have
been tested in portions of New England and Canadian waters. These
systems employ various digital acoustic monitoring instruments, which
have been placed on autonomous platforms including slocum gliders, wave
gliders, profiling floats, and moored buoys. Systems that have proven
to be successful will likely see increased use as operational tools for
many whale monitoring and mitigation applications. A recent report
published by NMFS summarizes a workshop NMFS convened to address
objectives specifically related to monitoring NARWs and presents the
Expert Working Group's recommendations for a comprehensive monitoring
strategy to guide future analyses and data collection (``Technical
Memorandum NMFS[hyphen]OPR[hyphen]64: North Atlantic Right Whale
Monitoring and Surveillance: Report and Recommendations of the National
Marine Fisheries Service's Expert Working Group,'' which is available
at: https://www.fisheries.noaa.gov/resource/document/north-atlantic-right-whale-monitoring-and-surveillance-report-and-recommendations).
Among the numerous recommendations found in the report, the Expert
Working Group encouraged the widespread deployment of auto-buoys to
provide near real-time detections of NARW calls that visual survey
teams can then respond to for collection of identification photographs
or biological samples. Similar approaches utilizing real-time or
archival PAM could be utilized to monitor other marine mammal species
throughout the life cycles of offshore wind farms.
Comment 37: For comments and recommendations on high-resolution
geophysical survey activities, the ENGOs directed NMFS to their letter
submitted on September 9, 2020, regarding NMFS' failure to adequately
protect endangered and protected marine mammals during marine site
characterization surveys required for offshore wind development.
Response: NMFS refers the ENGOS to the Federal Register notice 85
FR 63508 (October 8, 2020) for previous responses to the ENGOs'
previous letter.
Comment 38: The ENGOs recommended that NMFS coordinate with BOEM to
establish and fund a robust, long-term scientific plan to monitor the
effects of offshore wind development on marine mammals and other
species before, during, and after large-scale commercial projects are
constructed.
Response: NMFS appreciated the ENGOs' recommendation and will
continue working with BOEM to develop strategies for monitoring the
impacts of offshore wind development on protected species.
Comment 39: RODA expressed concern about potential negative impacts
(i.e., increased restrictions or other constraints) to Atlantic
fisheries, local fisherman, and coastal communities resulting from any
potential adverse impacts to NARWs and other protected species from
offshore wind construction projects, noting that impacts on the fishing
industry were not addressed in the proposed IHA.
Response: The socio-economic impacts of the South Fork Wind's
activities are evaluated in the Final Environmental Impact Statement
(FEIS) prepared by BOEM to assess the effects of construction and
operation of the project, and which NMFS adopted to support the
issuance of the IHA. However, neither the MMPA nor our implementing
regulations require NMFS to analyze impacts to other industries (e.g.,
fishermen) or coastal communities from issuance of an ITA. In order to
issue an ITA, Sections 101(a)(5)(A) and 101(a)(5)(D) of the MMPA
require NMFS to make a determination that the take incidental to a
``specified activity'' will have a negligible impact on the affected
species or stocks of marine mammals, and will not result in an
unmitigable adverse impact on the availability of marine mammals for
taking for subsistence uses. NMFS has made the required determinations.
Comment 40: RODA expressed concern that the presence of offshore
wind turbines may impact low altitude aerial surveys conducted by NOAA/
NMFS to monitor protected species, including NARWs, as the height of
the turbines would exceed the survey altitude.
Response: NMFS has determined that offshore wind development
projects in the Northeast will impact several NEFSC surveys, including
the aerial surveys for protected species. NEFSC has developed a federal
survey mitigation program to mitigate the impacts to these surveys, and
is in the early stages of implementing this program. However, this
impact is outside the scope of analysis related to issuance of take
incidental to the specified activity under the MMPA.
Comment 41: RODA stated that offshore wind site characterization
surveys using HRG equipment could result in long-term and high-
intensity impacts on marine mammals. In addition, RODA questions the
efficacy of mitigation measures prescribed for such surveys, stating
that it is presumptive to assume that mitigation measures are
sufficient to eliminate adverse impacts to marine mammals and guarantee
that no NARWs will be harmed during site characterization surveys.
Response: This IHA does not cover site characterization surveys--
nevertheless, the construction surveys covered similarly utilize HRG
equipment. RODA provides no evidence that site characterization surveys
could result in long-term and high-intensity impacts on marine mammals,
and that NARWs could be harmed during these surveys. The surveys
utilizing HRG equipment SFEC (construction surveys) that will be
conducted under the South Fork Wind IHA are specifically to assess the
inter-array and export cables during construction of the SFWF, are
relatively small scale (i.e., no more than 60 days of survey
activities), and use HRG equipment with small associated Level A
harassment and Level B harassment zones (maximum of 141 m for Level B
harassment). Both the clearance and shutdown zones for NARWs are more
than three times the size of the Level B harassment zone (i.e., 500 m),
making it unlikely that NARWs would even experience Level B harassment
from surveys, let alone more significant or long-term impacts. In
contrast to RODA's comment, the Commission, the agency charged with
advising federal agencies on the impacts of human activity on marine
mammals, has questioned in its comments whether incidental take
authorizations are even necessary for surveys utilizing HRG equipment
(i.e., take is unlikely to occur).
BOEM (2021a) reviewed underwater noise levels produced by the
available types of HRG survey equipment as part of a programmatic
biological assessment for this and other activities associated
with regional offshore wind energy development. NMFS (2021) concurred
with BOEM's determination that planned marine site characterization
survey activities using even the loudest available equipment types
would be unlikely to injure or measurably affect the behavior of ESA-
listed marine mammals. The rationale supporting this conclusion also
applies to non-listed marine mammal species. Specifically, the noise
levels produced by HRG survey equipment are relatively low, meaning
that an individual marine mammal would have to remain very close to the
sound source for extended periods to experience auditory injury. This
type of exposure is unlikely as the sound sources are continuously
mobile and directional (i.e., pointed at the bottom). Along those
lines, on June 29, 2021, NMFS GARFO concluded ESA consultation with
BOEM and NMFS, finding that marine site assessment surveys using HRG
equipment similar to that used by the surveys planned under this South
Fork Wind IHA, may effect, but are not likely to adversely affect, ESA-
listed marine mammals provided the project design criteria (PDC) and
best management practices (BMP) proposed by BOEM are incorporated. NMFS
has included those PDCs and BMPs in South Fork Wind's IHA, including
the use of protected species observer (PSO) monitoring of species-
specific clearance zones around specified HRG equipment (i.e., boomers,
sparkers, and Chirps), and mandatory shutdown procedures to further
minimize exposure risk. While individual marine mammals may be exposed
to marine site characterization survey noise sufficient to cause
behavioral effects rising to the level of take under the MMPA, those
Upon request, NMFS has conservatively issued take, by Level B
harassment, incidental to construction surveys using HRG equipment.
Comment 42: RODA expressed interest in understanding the outcome if
the number of actual takes exceed the number authorized during
construction of an offshore wind project (i.e., would the project be
stopped mid-construction or mid-operation), and how offshore wind
developers will be held accountable for impacts to protected marine
species such that impacts are not inadvertently assigned to fishermen.
Response: It is important to recognize that an IHA does not
authorize the activity but authorizes take of marine mammals incidental
to the activity. As described in condition 3(b) and (c) of the IHA,
authorized take, by Level A harassment and Level B harassment only, is
limited to the species and numbers listed in Table 1 of the final IHA,
and any taking exceeding the authorized amounts listed in Table 1 is
prohibited and may result in the modification, suspension, or
revocation of the IHA. As described in condition 3(f), if an individual
from a species for which authorization has not been granted, or a
species for which authorization has been granted but the authorized
take number has not been met, is observed entering or within the Level
B harassment zone (construction surveys) or clearance zone (both impact
and vibratory piles driving), HRG acoustic sources and pile-driving
activities must be shut down immediately (when technically feasible as
described under condition 4(a)(ix)(1) of the final IHA). Pile driving
and reinitiation of HRG acoustic sources must not resume until the
animal has been confirmed to have left the relevant clearance zone or
the observation time (as indicated in conditions 4(a)(xi)(2),
4(b)(i)(6)), and 4(c)(i)(4) of the final IHA) has elapsed with no
further sightings.
It is unclear why RODA would be concerned that impacts would be
``inadvertently assigned'' to fishermen. Fishing impacts generally
center on entanglement in fishing gear, which is a very acute, visible,
and severe impact. In contrast, the pathway by which impacts occur
incidental to construction is primarily acoustic in nature. Regardless,
any take beyond that authorized is unlawful. If the authorized takes
were exceeded, but the project could proceed without additional take of
marine mammals, it would be lawful. It is BOEM's responsibility as the
permitting agency to make decisions regarding ceasing the project. If
the case suggested by RODA does occur, NMFS would work with BOEM and
South Fork Wind to determine the most appropriate means by which to
ensure compliance with the MMPA.
Comment 43: A commenter from the general public suggested that
there is a lack of baseline auditory physiology data and adequate
conservation metrics for sea turtles, finfish, and other marine species
in the project area. The commenter correctly noted that the mitigation
measures included in the proposed IHA do not include protections for
sea turtles.
Response: Under the MMPA, NMFS is charged with analyzing the
impacts from the specified activity to marine mammals and their
habitat, including their prey (e.g., fish and invertebrates), and to
prescribe the permissible means of taking and other ``means of
effecting the least practicable adverse impact'' on the affected
species or stocks and their habitat. In the Effects to Prey section of
the notice of the proposed IHA (84 FR 8690, February 5, 2021), NMFS
provides a summary and discussion of the ways noise produced by
construction activities might impact fishes. 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 range, anatomy, and physiology. Key impacts to fishes may
include behavioral responses, hearing damage, barotrauma (pressure-
related injuries), and mortality. However, the most likely impact to
fishes from impact and vibratory pile-driving activities in the project
areas would be temporary avoidance of the area. The duration of fish
avoidance of an area is unknown, but given the relatively short
duration of vibratory pile driving (18 hours each for installation and
removal), and the small number of monopiles planned for installation,
NMFS anticipates a rapid return to normal recruitment, distribution,
and behavior. In general, impacts to marine mammal prey species are
expected to be minor and temporary.
Because sea turtles are not marine mammals, no protections are
afforded to them under the MMPA. However, we refer the commenter to
NMFS' Biological Opinion, issued October 1, 2021. The Biological
Opinion, issued pursuant to the ESA, contains an analysis on the
impacts to ESA-listed fish and all sea turtles (as all sea turtle
species are listed as endangered or threatened under the ESA). Impacts
to non-listed fishes may be found in BOEM's Final EIS for the project,
issued August 20, 2021, and found here: https://www.boem.gov/renewable-energy/state-activities/south-fork.
Comment 44: A commenter from the general public identified several
scientific journal articles that discuss the diving physiology of
marine mammals, and stated that NMFS should consider this information
as it relates to potential avoidance behavior marine mammals might
demonstrate as a result of impact pile driving.
Response: NMFS used the best available science in developing its
impact analysis and making the findings required to issue the requested
IHA. The proposed IHA notice acknowledges avoidance as a potential
response of a marine mammal when exposed to noise from project
construction and identifies that such a response may reduce the
potential of more severe impacts such as PTS. While the commenter was
not specific about how NMFS should consider the suggested literature
to diving behavior, the Level A Harassment exposure estimates modeled
by JASCO incorporated known dive behavior via animat modeling. However,
NMFS has found that incorporating a behavior such as avoidance into an
exposure model is extremely complex and contains a high degree of
uncertainty. For this reason, the exposure modeling, and resulting
take, do not consider avoidance behavior. NMFS reviewed the references
provided by the commenter and determined that that the information
contained therein was not sufficient to lead NMFS to reach any other
conclusions regarding the impacts of pile driving on marine mammals.
Comment 45: A commenter from the general public stated that the
proposed IHA would have benefited from NMFS' consideration of input
from public comments on the DEIS and subsequent corrections in BOEM's
Final Environmental Impact Statement (FEIS), which assesses the
physical, biological, and social/human impacts of the South Fork Wind
project and all reasonable alternatives.
Response: NMFS' proposal to issue an IHA under the MMPA to
authorize the taking of marine mammals incidental to South Fork Wind's
in-water construction activities was a major federal action for
purposes of the National Environmental Policy Act (NEPA), necessitating
preparation of an appropriate level NEPA document. NMFS chose to
satisfy this obligation by actively working with BOEM as a cooperating
agency on the Draft Environmental Impact Statement (DEIS) and Final
Environmental Impact Statement (FEIS) for the South Fork Wind offshore
wind project. Once the FEIS was completed, NMFS independently evaluated
it and determined the FEIS was sufficient to satisfy NMFS' independent
NEPA responsibilities. NMFS drafted a memorandum for the record
documenting its rationale for adopting BOEM's FEIS. NMFS then signed a
Joint Record of Decision (ROD) in which it selected the alternative of
issuing the IHA to South Fork Wind, explained the factors it considered
in doing so, and specified the mitigation measures that would be
Changes From Proposed IHA to Final IHA
In the final IHA, NMFS Office of Protected Resources (OPR) adopted
the Terms and Conditions of the October 2021 Biological Opinion for the
South Fork Offshore Energy Project, the August 2021 Programmatic
Consultation on marine site assessment surveys, and made other
modifications as a result of public input on the proposed IHA, which
resulted in changes to mitigation and monitoring measures from proposed
to final IHA. NMFS provides a summary here, and the changes are also
described in the specific applicable sections below (e.g., Mitigation).
A complete list of final measures may be found in the issued IHA
(available at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable).
Please note that since publication of the notice of the proposed
IHA, NMFS has changed terminology from exclusion zone to shutdown zone
to clarify the mitigation action to be taken when a marine mammal
enters this zone. In addition, in order to distinguish surveys using
HRG equipment to obtain a baseline assessment of seabed, ecological,
and archeological conditions within the footprint of future offshore
wind development (marine site characterization) from those surveys
planned under this IHA (also using HRG equipment) to assess the inter-
array and export cables throughout construction of the SFWF and SFEC,
NMFS has changed terminology from HRG surveys to construction surveys.
to NMFS that construction activities will not commence until November
2022, rather than between April and May 2022 (as indicated in the
proposed IHA). Therefore, the period of effectiveness of the IHA is
November 15, 2022 to November 14, 2023.
In addition to the seasonal restriction on impact pile driving of
monopiles from January 1 through April 30 included in the proposed IHA,
the final IHA specifies that impact pile driving of monopiles must not
occur in December unless an unanticipated delay due to weather or
technical problems, notified to and approved by BOEM, arises that
necessitates extending impact pile driving of monopiles through
December.
After further consideration, NMFS modified several zone sizes
associated with monitoring and mitigation measures to provide
additional protection for NARWs. The final IHA includes the condition
that any large whale visually observed by a PSO within 2,000 m, or as
modified based on SFV measurements, of the impact pile-driving vessel
that cannot be identified to species must be treated as if it were a
NARW for clearance and shutdown purposes. The distance has been
increased from 1,000 m (included in the proposed IHA) to 2,000 m to
align with the large whale shutdown zone. Similarly, the distance
within which PSOs must treat an unspecified large whale as a NARW
during vibratory pile driving has been increased from 1,000 m to 1,500
m for the same reason. In the final IHA, NMFS has defined the minimum
visibility zone, or the area over which PSOs must be able to clearly
observe marine mammals to begin the clearance process, as 2.2 km. In
addition, NMFS has clarified that the 2.2 km large whale clearance zone
included in the notice of proposed IHA (Table 24) is the minimum visual
clearance zone (i.e., the zone that must be both fully visible and
clear of NARWs and other large whales for 30 minutes immediately prior
to commencing impact pile driving of monopiles)--beyond that distance,
PAM, in conjunction with visual monitoring (recognizing the visibility
limitations under certain conditions), must be used to confirm that the
5 km NARW clearance zone is clear of NARW's and other large whales
prior to commencing impact pile driving of monopiles.
to NMFS that the PAM system will be designed such that the PAM PSO will
be capable of reviewing acoustic detections within 5 minutes of the
original detection, rather than 15 minutes (as indicated in the
proposed IHA), to determine if a NARW was detected. This reduced
evaluation time provides improved support for near real-time mitigation
actions, should they be required. While the proposed IHA required a PAM
PSO to have 75-percent confidence that a vocalization originated from a
NARW to call for a delay or shutdown of impact pile driving of
monopiles, the final IHA only requires that a PAM PSO categorize a call
as having a probable (or greater) likelihood of originating from a NARW
(scale: No, possible, probable, yes). In addition, South Fork Wind is
required to communicate detections of all marine mammals detected at
any distance (i.e., not limited to the 5 km Level B harassment zone) to
visual PSOs for situational awareness. Finally, the final IHA now
specifies that the PAM system(s) must not be placed closer than 1 km to
the pile being driven.
The final IHA includes several additional vessel strike avoidance
measures to provide enhanced protection for NARWs. South Fork Wind must
use available sources of information on NARW presence, including (1)
daily monitoring of the Right Whale Sightings Advisory System, (2)
consulting the WhaleAlert app, and (3) monitoring of Coast Guard VHF
Channel 16 throughout the day to receive notifications of any sightings
and information associated with any Dynamic Management Areas (DMAs), to
plan construction activities and vessel routes, if practicable, to
minimize the potential for co-occurrence with NARWs. This measure was
not included in the proposed IHA but affords increased protection of
NARWs by raising awareness of NARW presence in the area through
monitoring efforts outside of South Fork Wind's efforts. In addition,
whenever multiple project-associated vessels (e.g., construction
survey, crew transfer) are operating concurrently, any visual
observations of ESA-listed marine mammals must be communicated to PSOs
and/or vessel captains associated with other vessels to increase
situational awareness. While the proposed IHA only required vessels
greater than or equal to 65 ft (19.8 m) to immediately reduce speed to
10 kts or less when a NARW is sighted at any distance by the observer
or anyone on the underway vessel (or any other large whale, mom/calf
pair, or large assemblage of non-delphinoid cetaceans are observed near
(within 100 m) of an underway vessel), the final IHA includes vessels
of all sizes in this requirement. The final IHA requires that
confirmation of marine mammal observer training (including an
understanding of the IHA requirements) must be documented on a training
course log sheet and reported to NMFS for those dedicated visual
observers required on vessels that are traveling over 10 knots. In
addition, NMFS now requires that when a marine mammal is observed
during vessel transit, the following data must be collected: Time, date
and location (latitude/longitude); the vessel's activity, heading and
speed; sea state, water depth and visibility; marine mammal
identification to the best of the observer's ability (e.g., NARW,
whale, dolphin, seal); initial distance at which the marine mammal was
observed from the vessel and closest point of approach; and any
avoidance measures taken in response to the marine mammal sighting.
South Fork Wind is required to implement a noise mitigation system
to reduce noise during impact pile driving of monopiles such that the
measured ranges to Level A harassment and Level B harassment isopleths
are equal to or less than those predicted by acoustic modeling,
assuming 10-dB attenuation. The proposed IHA included the use of a
single BBC, while the final IHA specifies that South Fork Wind must use
(at a minimum) a single BBC coupled with an additional noise mitigation
device, or a dBBC.
The final IHA requires verification of the Level A harassment and
Level B harassment zones through sound field verification (SFV),
whereas the proposed IHA only required verification of the Level B
harassment zone. Additionally, the final IHA now specifies that NMFS
may expand the relevant clearance and shutdown zones in the event that
field measurements indicate ranges to Level A harassment and Level B
harassment isopleths are consistently greater than the ranges predicted
by modeling, assuming 10-dB attenuation (see Acoustic Monitoring for
Sound Field and Harassment Isopleth Verification section). However, if
harassment zones are expanded beyond an additional 1,500 m, additional
PSOs must be deployed on additional platforms, with each observer
responsible for maintaining watch in no more than 180[deg], and of an
area with a radius no greater than 1,500 m. Depending on the extent of
zone size expansion, reinitiation of consultation under Section 7 of
the ESA may be required. Conversely, if initial acoustic field
measurements indicate ranges to the isopleths corresponding to Level A
harassment and Level B harassment thresholds are less than the ranges
predicted by modeling (assuming 10-dB attenuation), South Fork Wind may
request a modification of the clearance and shutdown zones for impact
pile driving of monopiles. However, for a modification request to be
considered by NMFS, South Fork Wind must have conducted SFV on at least
three piles in representative monopile installation locations (e.g.,
substrate type, water depth) to verify that zone sizes are consistently
smaller than those predicted by modeling, assuming 10-dB attenuation.
In the event that subsequently driven monopiles require greater hammer
energy or substrate conditions suggest noise generated from the
activity could produce larger sound fields, SFV must be conducted for
those subsequent piles. Should NMFS approve reductions in zone sizes
(i.e., Level A harassment, Level B harassment, clearance and/or
shutdown) for impact pile driving of monopiles, the minimum visibility
zone will not be decreased to a size smaller than 2.2 km. The shutdown
and clearance zones would be equivalent to the measured range to the
Level A harassment isopleth plus 10 percent and 20 percent,
respectively, rounded up to the nearest 100 m for PSO clarity. The
shutdown zone for sei, fin, and sperm whales must not be reduced to a
size less than 1,000 m. The visual and PAM clearance and shutdown zones
for NARWs must not be decreased, regardless of acoustic field
measurements. The Level B harassment zone would be equal to the largest
measured range to the Level B harassment isopleth. Finally, the final
IHA requires South Fork Wind to report hammer energies required for
each monopile installation, as well as ambient noise spectra.
There are several additional planning and reporting requirements
included in the final IHA. Specifically, NMFS is requiring that South
Fork Wind prepare and submit Pile Driving and Marine Mammal Monitoring
Plans to NMFS for review and approval at least 90 days before the start
of any pile driving. The plans must include final project design
related to all pile driving (e.g., number and type of piles, hammer
type, noise mitigation equipment, anticipated start date, etc.), and
all information related to PAM PSO protocols and visual PSO protocols
(including alternative monitoring technology (i.e., IR/Thermal
camera)), for all activities. South Fork Wind must also submit a NARW
vessel strike avoidance plan 90 days prior to commencement of vessel
use. The plan will describe, at a minimum, how PAM will be conducted to
ensure the transit corridor(s) is clear of NARWs and provide details on
vessel-based observer protocols on transiting vessels. Submission of
the above plans was not required in the proposed IHA.
When reporting the results of SFV, South Fork Wind must include (in
addition to the information that was included as a requirement in the
proposed IHA) the bandwidth, hydrophone sensitivity, a description of
the depth and sediment type at the recording and pile-driving
locations, and any action taken to adjust the noise mitigation system.
In addition to the final report, the IHA requires South Fork Wind to
provide the initial results of SFV to NMFS in an interim report after
each monopile installation for the first three piles as soon as they
are available, but no later than 48 hours after each installation.
If a NARW is detected via PAM, the date, time, location of the
detection, and the recording platform must be reported to NMFS as soon
as feasible but no longer than 24 hours after the detection. Full
detection data and metadata must be submitted on the 15th of every
month for the previous month. Prior to initiation of the project
activities, South Fork Wind must demonstrate in a report submitted to
NMFS ([email protected]) that all required training has been completed
for South Fork Wind personnel (including vessel crew and
captains, and PSOs). This report was not required in the proposed IHA.
The proposed IHA only required that South Fork Wind submit a draft
report on all monitoring conducted under the IHA within 90 days of
completion of the monitoring efforts. Since that time, NMFS determined
that more frequent reviews of South Fork Wind's monopile installation
activities and monitoring data are warranted. In the final IHA, South
Fork Wind is required to submit weekly and monthly reports (see
Reporting section for details). Finally, NMFS has updated the contact
information for reporting injured or dead marine mammals, or a vessel
strike, in the event that South Fork Wind needs to report either.
From the proposed IHA to the final IHA, NMFS modified the take
number for blue whales. The proposed IHA allocated one take, by Level B
harassment, of a blue whale incidental to impact pile driving of
monopiles, even though animal exposure modeling resulted in zero blue
whale exposures (by Level A harassment or Level B harassment). However,
after further examination, NMFS has determined that the potential for
even Level B harassment of this species is de minimus and NMFS is not
authorizing take by Level B harassment. The area is not a preferred
blue whale habitat, as the species generally prefers deeper water and
bathymetric features such as the continental shelf edge. In addition,
there have been no blue whale sightings during previous monitoring
efforts within and near the SFWF and SFEC (e.g., CSA 2020; Smultea
Environmental Sciences 2020; Gardline 2021). For these reasons, NFMS
does not adopt the Commission's recommendation to authorize (in
addition to the proposed single take, by Level B harassment, which is
now considered de minimus) one take, by Level A harassment (PTS), of a
blue whale incidental to impact pile driving of monopiles.
Per the Commission's recommendation, NMFS has modified take, by
Level B harassment, incidental to impact pile driving of monopiles for
long-finned pilot whales, Atlantic spotted dolphins, common dolphins,
and bottlenose dolphins. The take numbers, by Level B harassment,
included in the proposed IHA for these species were those requested by
South Fork Wind in the IHA application. Upon further review of
scientific literature (DoN 2017; Smultea Sciences, 2020; CSA 2921;
AMAPPS 2021), NMFS updated the reference for average group size for
each species and conservatively selected the largest average group size
for each species reported among references as the basis for increasing
take numbers from the proposed to the final IHA. NMFS selected the
group size reported for long-finned pilot whales (n=20) in CETAP (1982)
and increased take, by Level B harassment, from 12 (included in the
proposed IHA) to 20 (Table 18). Barkaski and Kelly (2018) report an
average group size of 13 for Atlantic spotted dolphins, which is
similar to the average group size based on sighting data within and
near the SFWF and SFEC (Smultea Sciences, 2020). To account for group
size, NMFS conservatively increased take, by Level B harassment, of
Atlantic spotted dolphins from 2 to 13 (Table 18). To account for the
frequent occurrence of common dolphins and bottlenose dolphins in the
project area, NMFS increased take, by Level B harassment, by
multiplying the largest group size (common dolphins (35), bottlenose
dolphins (21.6); AMAPPS 2021) by the maximum number of days on which
monopile installation might occur (n=16), resulting in 560 common
dolphin takes and 346 bottlenose dolphins takes. Given the large size
of the Level B harassment zone for vibratory pile driving
(approximately 36 km), NMFS agreed with the Commission's recommendation
to modify take, by Level B harassment, of humpback whales, as well as
common dolphins and Atlantic white-sided dolphins. NMFS based take
increases on the largest estimated group sizes for each species using
the best available science (DoN 2017; Smultea Sciences, 2020; CSA 2921;
AMAPPS 2021). For humpback whales and common dolphins, the largest
estimated group sizes (humpback whales (1.6), common dolphins (35);
AMAPPS (2021)) were multiplied by the number of days over which
vibratory pile driving might occur (18 hours over 3 days for
installation, 18 hours over 3 days for removal, total = 6 days). This
approach resulted in the following increases in takes, by Level B
harassment, from the proposed IHA to the final IHA: Humpback whales
(from 1 to 9.6, rounded to 10) and common dolphins (from 4 to 210).
Animal exposure modeling predicted one take, by Level B harassment, of
an Atlantic white-sided dolphin incidental to vibratory pile driving,
although sightings of this species are uncommon in the project area.
However, NMFS has conservatively authorized 50 takes (or the equivalent
of the largest seasonal group size, reported for summer; AMAPPS 2021),
by Level B harassment, of Atlantic white-sided dolphins. As described
in the Comments and Responses section, the Commission also recommended
increasing take, by Level B harassment, of fin and sei whales
incidental to vibratory pile driving. Exposure modeling resulted in
exposures for each of 10 months (October-May; Table 19) for all species
potentially impacted by vibratory pile driving. Of the remaining
months, fin whale exposure estimates were zero (November-February) and
one (in both March and May). The proposed take estimate was already
conservatively based on the month with the highest number of modeled
exposures (April; n=2), and sightings of fin whales are less frequent
along the ECR and nearshore HDD site as compared to in/near the Lease
Area (e.g., Smultea Sciences, 2020). For these reasons, NMFS does not
find that increasing take of fin whales, by Level B harassment, is
warranted. As for sei whales, exposure modeling resulted in zero
exposures in all 10 months considered (Table 19). As described in the
Comments and Responses section, sei whale sightings are relatively rare
throughout the project area, which agrees with the generally offshore
pattern of sei whale distribution (Hayes et al., 2021). Given the brief
timeframe for cofferdam installation/removal, the low likelihood of sei
whale occurrence in the project area during that brief timeframe, and
the lack of exposures resulting from exposure modeling, NMFS does not
find that increasing take, by Level B harassment, is warranted.
After review of the scientific literature, NMFS has increased take
of long-finned pilot whales, by Level B harassment, incidental to
construction surveys from 4 (proposed) to 20 (authorized) based on the
largest estimated group size (CETAP 1982).
Since publication of the proposed IHA, South Fork Wind proposed the
installation of a temporary casing pipe using a small pneumatic impact
hammer at the horizontal directional drilling (HDD) exit pit location
for the SFEC as an alternative to the previously assessed sheet pile
cofferdam at the same location. The cofferdam, but not the casing pipe
alternative, was considered in the acoustic impact analysis performed
by JASCO in support of the South Fork Wind Construction Operation Plan
(COP) (Denes et al., 2020a,b). However, JASCO recently provided NMFS
with an general assessment of the potential acoustic impacts of casing
pipe installation, showing that it is expected to have less than, or
equal, acoustic impact relative to vibratory pile driving to construct
a cofferdam. No potential injurious exposures are expected for
of the cofferdam (see Estimated Take), and are, therefore, not expected
for installation of the casing pipe. The range to behavioral disruption
is less for casing pipe driving using a small impact hammer
(approximately 2,154 m) than for cofferdam construction using vibratory
pile driving (approximately 36,000 m). If temporary supports for the
casing pipe are needed during the HDD installation, vibratory pile
driving of up to 8 sheet piles may be required (resulting in a 36,000 m
range to behavioral disruption during installation of the support sheet
piles). South Fork Wind estimates that the entire installation and
removal will each take approximately four hours to complete. In
comparison, installation of a temporary cofferdam would require
vibratory pile driving of approximately 80-100 sheet piles for up to 18
hours for installation and an additional 18 hours for removal. If
vibratory pile driving of support sheet piles for the casing pile is
required, the range to the Level B harassment isopleth may be the same
as for cofferdam construction, but the potential for take would occur
over a shorter duration. Regardless of the construct selected for
installation at the exit pit location, South Fork Wind will adhere to
the more conservative mitigation and monitoring requirements for the
installation of the cofferdam (as proposed by South Fork Wind and
described in the notice of the proposed IHA (86 FR 8490; February 5,
2021)). NMFS agrees with this approach, given that the larger zone
sizes and longer duration for cofferdam installation/removal encompass
the potential spatial and temporal scales for installation of the
casing pipe alternative. Accordingly, authorized take (by Level B
harassment only) in the final IHA is conservatively based on take
incidental to vibratory pile driving associated with installation/
removal of the cofferdam.
In addition to the changes described above, NMFS has also (1)
revised tables in the Federal Register notice and IHA so all the
harassment, clearance, and shutdown zones align between the Federal
Register notice and final IHA, (2) corrected the reported maximum water
depth in the project area to 90 m, (3) corrected a typographical error
in Table 8 to reflect the fact that the mean Level A harassment zone
for a difficult-to-drive pile based on the cumulative SEL
(SELcum) thresholds for low-frequency cetaceans is 7,868 m
rather than 7,846 m, 4) aligned the Level A harassment zones in Tables
10 and 24 based on the SELcum thresholds for gray seals and
in Tables 7 and 24 based on the peak sound pressure level
(SPLpeak) thresholds for harbor porpoises, and gray and
harbor seals, 5) corrected the Level B harassment zone for Chirps to 54
m in Table 28, 6) corrected the Level A harassment zone
(SPL0-pk) for high-frequency cetaceans for AA Triple plate
S-Boom (700/1,000 J) to 2.8 m in Table 12, 7) removed visibility
metrics from the reporting requirements for SFV, and 8) added a target
air flow rate of at least 0.5 m\3\/(min*m) for the bubble curtain(s)
used for noise mitigation during impact pile driving of monopiles. In
addition, the final IHA specifies that if a species for which
authorization has not been granted, or, a species for which
authorization has been granted but the authorized number of takes has
been met, approaches or is observed within the Level B harassment zone
(rather than the clearance zone, as specified in the proposed IHA),
impact pile driving of monopiles must not commence or resume until the
animal has been confirmed to have left the Level B harassment zone or a
full 15 minutes (small odontocetes and seals) or 30 minutes (for all
other marine mammals) have elapsed with no further sightings. Finally,
NMFS did not include language in the final IHA related to a Renewal
IHA. This does not necessarily preclude a Renewal IHA but, as described
above, NMFS thinks a Renewal IHA is unlikely in this case, given the
potential for changes over the next two years that could affect the
analyses germane to construction of the SFWF and SFEC.
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 36 marine mammal species that could potentially occur in
the project area and that are included in Table 16 of the IHA
application. However, the temporal and/or spatial occurrence of 21 of
these species is such that take is not expected to occur or authorized,
and they are, therefore, not discussed further beyond the explanation
provided here. The following species are not expected to occur in the
project area due to their more likely occurrence in habitat that is
outside the SFWF and SFEC, based on the best available information: The
blue whale (Balaenoptera musculus), 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), pygmy sperm whale (Kogia breviceps), Cuvier's beaked whale
(Ziphius cavirostris), Mesplodont beaked whales (spp.), short-finned
pilot whale (Globicephala macrorhynchus), pantropical spotted dolphin
(Stenella attenuata), Fraser's dolphin (Lagenodelphis hosei), white-
beaked dolphin (Lagenorhynchus albirostris), rough-toothed dolphin
(Steno bredanensis), Clymene dolphin (Stenella clymene), spinner
dolphin (Stenella longirostris), and striped dolphin (Stenella
coeruleoalba). The following species may occur in the project area, but
at such low densities that take is not anticipated: Hooded seal
(Cystophora cristata) and harp seal (Pagophilus groenlandica). There
are two pilot whale species (long-finned (Globicephala melas) and
short-finned (Globicephala macrorhynchus)) with distributions that may
overlap in the latitudinal range of the SFWF (Hayes et al., 2021;
Roberts et al., 2016). Because it is difficult to differentiate between
the two species at sea, sightings, and thus the densities calculated
from them, are generally reported together as Globicephala spp. (Hayes
et al., 2021; Roberts et al., 2016). However, based on the best
available information, short-finned pilot whales generally occur in
habitat that is both further offshore on the shelf break and further
south than the project area (Hayes et al., 2021). Therefore, NMFS
assumes that any take of pilot whales would be of long-finned pilot
whales.
In addition, the Florida manatee (Trichechus manatus) may be found
in the coastal waters of the project area. However, Florida manatees
are managed by the U.S. Fish and Wildlife Service and are not
considered further in this document.
Between October 2011 and June 2015, a total of 76 aerial surveys
were conducted throughout the MA and RI/MA WEAs. As mentioned
previously, the SFWF is contained within the RI/MA WEA (along with
several other offshore renewable energy Lease Areas). Between November
2011 and March 2015, Marine Autonomous Recording Units (MARUs; a type
of static PAM recorder) were deployed at nine sites in the MA and RI/MA
WEAs. The goal of
the study was to collect visual and acoustic baseline data on
distribution, abundance, and temporal occurrence patterns of marine
mammals (Kraus et al., 2016). The lack of acoustic detections or
sightings of any of the species listed above reinforces the fact that
these species are not expected to occur in the project area. In
addition, during recent marine site characterization surveys of the
South Fork Wind Lease Area, none (other than long-finned pilot whales)
of the aforementioned species were observed during marine mammal
monitoring (Smultea Sciences, 2020; CSA, 2021). Further, acoustic
detections of four species of baleen whales in data collected from
2004-2014 show important distributional changes over the range of these
baleen whale species (Davis et al., 2020). That study showed blue
whales were more frequently detected in the northern latitudes of the
study area after 2010, and no detections occurred in the project area
in spring, summer, and fall when impact pile driving of monopiles would
occur (Davis et al., 2020). As the species identified above are not
expected to occur in the project area during the planned activities,
they are not discussed further in this document.
NMFS expects that the 15 species listed in Table 3 will potentially
occur in the project area and may, therefore, be taken as a result of
the project. Table 3 summarizes information related to the population
or stock, including regulatory status under the MMPA and Endangered
Species Act (ESA) and potential biological removal (PBR), where known.
For taxonomy, NMFS follows the Committee on Taxonomy (2020). 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. Four 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
planned activity: The NARW, fin whale, sei whale, and sperm whale.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS' U.S. Atlantic SARs. All values presented in Table 3 are the most
recent available at the time of publication, which can be found in the
NMFS' 2021 Draft SARs (Hayes et al., 2021), available online at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.
Table 3--Marine Mammals Known To Occur In the Project Area That May be Affected By South Fork Wind's Construction Activities
MMPA and ESA    Stock abundance  (CV,
status;        Nmin, most  recent                     Annual M/SI      Occurrence and
Common name (scientific name)            Stock           strategic (Y/N)  abundance survey) \2\      PBR \3\           \3\          seasonality in
\1\                                                                   project area
Toothed whales (Odontoceti)
Sperm whale (Physeter               North Atlantic.......  E; Y              4,349 (0.28; 3,451;               3.9               0  Rare.
macrocephalus).                                                              2016).
Long-finned pilot whale             W. North Atlantic....  --; N             39,215 (0.3; 30,627;              306              29  Rare.
(Globicephala melas).                                                        2016).
Atlantic spotted dolphin (Stenella  W. North Atlantic....  --; N             39,921 (0.27; 32,032;             320               0  Rare.
frontalis).                                                                  2016).
Atlantic white-sided dolphin        W. North Atlantic....  --; N             93,233 (0.71; 54,443;             544              27  Common year round.
(Lagenorhynchus acutus).                                                     2016).
Bottlenose dolphin (Tursiops        W. North Atlantic,     --; N             62,851 (0.23; 51,914;             519              28  Common year round.
truncatus).                         Offshore.                                2019).
Common dolphin (Delphinus delphis)  W. North Atlantic....  --; N             172,974 (0.21;                  1,452             390  Common year round.
145,216; 2016).
Risso's dolphin (Grampus griseus).  W. North Atlantic....  --; N             35,215 (0.19; 30,051;             301              34  Rare.
Harbor porpoise (Phocoena           Gulf of Maine/Bay of   --; N             95,543 (0.31; 74,034;             851             164  Common year round.
phocoena).                          Fundy.                                   2019).
Baleen whales (Mysticeti)
North Atlantic right whale          W. North Atlantic....  E; Y              368 (0; 364; 2019)...             0.7             7.7  Year round in
(Eubalaena glacialis).                                                                                continental shelf
and slope waters,
occur seasonally.
Humpback whale (Megaptera           Gulf of Maine........  --; N             1,396 (0.15; 1,375;                22              58  Common year round.
novaeangliae).                                                               2016).
Fin whale (Balaenoptera physalus).  W. North Atlantic....  E; Y              6,802 (0.24; 5,573;                11             1.8  Year round in
2016).                                                 continental shelf
Sei whale (Balaenoptera borealis).  Nova Scotia..........  E; Y              6,292 (1.02; 3,098 ;              6.2             0.8  Year round in
Minke whale (Balaenoptera           Canadian East Coast..  --; N             21,968 (0.31; 17,002;             170            10.6  Year round in
acutorostrata).                                                              2016).                                                 continental shelf
Earless seals (Phocidae)
Gray seal \4\ (Halichoerus grypus)  W. North Atlantic....  --; N             27,300 (0.22; 22,785;           1,389           4,453  Common year round.
Harbor seal (Phoca vitulina)......  W. North Atlantic....  --; N             61,336 (0.08; 57,637;           1,729             339  Common year round.
\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 or
which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS' 2021 Draft 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.
\3\ These values, found in NMFS' SAR, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated
with estimated mortality due to commercial fisheries is presented in some cases.
\4\ The NMFS stock abundance estimate applies to U.S. population only, however the actual stock abundance is approximately 451,431.
A detailed description of the species for which take has been
authorized, including brief introductions to the relevant stocks as
well as available information regarding population trends and threats,
and information regarding local occurrence, were provided in the
Federal Register notice for the proposed IHA (86 FR 8490; February 5,
2021). Since that time, the status of some species and stocks have been
updated, most notably for large whales. In particular, Pace (2021) and
NMFS' 2021 Draft SARS (Hayes et al., 2021) provide an updated
population estimate of 368 for NARWs, a decrease from the estimate of
412 reported in the notice of the proposed IHA (86 FR 8490; February 5,
2021). Table 3 includes the most recent population abundances, PBR, and
annual mortality and serious injury (M/SI) rates for all species. NMFS
refers the reader to the proposed IHA Federal Register notice for basic
descriptions of each species' status, and provides a summary of updates
below where necessary. Please also refer to NMFS' website (https://www.fisheries.noaa.gov/find-species) for generalized species accounts,
and note that Oleson et al. (2020) have established the project area as
year-round foraging habitat for NARWs.
As described in the proposed IHA notice, beginning in 2017,
elevated mortalities in the NARW population have been documented,
primarily in Canada but also in the U.S., and were collectively
declared an Unusual Mortality Event (UME). As of December 2021, 34
NARWs have been confirmed dead and an additional 16 have been
determined to be seriously injured. Entanglement and vessel strikes are
the primary causes of M/SI.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To assess the potential effects of exposure to sound
appropriately, it is necessary to understand the frequency ranges
marine mammals are able to hear. 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; in this case,
the lower bound from Southall et al. (2007) was retained. Marine mammal
hearing groups and their associated hearing ranges are provided in
Table 4--Marine Mammal Hearing Groups
[NMFS, 2018]
Generalized hearing
Hearing group                           range *
Low-frequency (LF) cetaceans (baleen whales)....  7 Hz to 35 kHz.
Mid-frequency (MF) cetaceans (dolphins, toothed   150 Hz to 160 kHz.
whales, beaked whales, bottlenose whales).
High-frequency (HF) cetaceans (true porpoises,    275 Hz to 160 kHz.
Kogia, river dolphins, cephalorhynchid,
Lagenorhynchus cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) (true seals).  50 Hz to 86 kHz.
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al. 2007) and PW pinniped (approximation).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
For more details concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Fifteen marine mammal species (13 cetacean and 2 pinniped (both phocid
species); Table 3) have the reasonable potential to co-occur with South
Fork Wind's construction activities. Of the cetacean species that may
be present, five are classified as low-frequency cetaceans (i.e., all
mysticete species), seven are classified as mid-frequency cetaceans
(i.e., all delphinid species and the sperm whale), and one is
classified as a high-frequency cetacean (i.e., harbor porpoise).
Potential Effects of Specified Activities on Marine Mammals and Their
The effects of underwater noise from South Fork Wind's construction
activities have the potential to result in harassment of marine mammals
in the vicinity of the project area. The notice of proposed IHA (86 FR
8490; February 5, 2021) included a discussion of the effects of
anthropogenic noise on marine mammals, and the potential effects of
underwater noise from South Fork Wind's construction activities on
marine mammals and their habitat. That information and analysis is
incorporated by reference into this final IHA determination and is not
repeated here; for more details, please refer to the notice of proposed
IHA (86 FR 8490; February 5, 2021).
Estimated Take
This section provides an estimate of the number of incidental takes
authorized through this IHA, which will inform both NMFS' consideration
of ``small numbers'' and the negligible impact determination. As noted
in the summary of Changes from Proposed IHA to Final IHA, changes have
been made to the number of takes for the given species incidental to:
Impact pile driving of monopiles (blue whales, pilot whales, Atlantic
spotted dolphins, common dolphins, and bottlenose dolphins); vibratory
pile driving (humpback whales, common dolphins, white-sided dolphins);
and construction surveys (pilot whales). Detailed descriptions are
provided in the Comments and Responses and Changes from Proposed IHA to
Final IHA sections, and below.
Harassment is the only type of take expected to result from South
Fork Wind's construction 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 take would primarily be by Level B harassment, as noise
from impact and vibratory pile driving and construction surveys has the
potential to result in disruption of behavioral patterns for individual
marine mammals, either directly or as a result of masking or temporary
hearing impairment (also referred to as temporary threshold shift
(TTS), as described in the notice of proposed IHA (86 FR 8490, February
5, 2021)). There is also some potential for auditory injury (Level A
harassment) to result for select marine mammals. Mitigation and
monitoring measures are expected to minimize the severity of such
taking to the extent practicable. No serious injury or mortality is
anticipated or authorized for this activity. Below we describe how the
take is estimated.
Generally speaking, NMFS estimates 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. NMFS notes 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, NMFS
describes the factors considered here in more detail and presents the
authorized take.
Acoustic Thresholds
NMFS recommends the use of 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
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 a received level
of 160 dB re 1 [mu]Pa (rms) for impulsive and/or intermittent sources.
South Fork Wind's activities includes the use of impulsive and
intermittent sources (e.g., impact pile driving, HRG acoustic sources),
and thus the 160 dB threshold applies. Quantifying Level B harassment
in this manner is also expected to capture any qualifying changes in
behavioral patterns that may result from TTS.
Level A harassment--NMFS' Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0)
(Technical Guidance, 2018) identifies dual criteria to assess auditory
injury (Level A harassment) to five different 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 South Fork Wind's activities that may result in take of
marine mammals include the use of impulsive and non-impulsive sources.
These thresholds are provided in Table 5. 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 5--Thresholds Identifying the Onset of Permanent Threshold Shift
PTS onset acoustic thresholds *
(received level)
Hearing group          ---------------------------------------
Impulsive         Non-impulsive
Low-Frequency (LF) Cetaceans....  Lpk,flat: 219 dB;   LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans....  Lpk,flat: 230 dB;   LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans...  Lpk,flat: 202 dB;   LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW)             Lpk,flat: 218 dB;   LE,PW,24h: 201 dB.
(Underwater).                     LE,PW,24h: 185 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 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, NMFS describes 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.
Impact Pile Driving of Monopiles: Acoustic Range
As described above, South Fork Wind plans install up to 15 WTGs and
one OSS in the SFWF (i.e., a maximum of 16 foundations). Two piling
scenarios may be encountered during construction and were, therefore,
considered in the modeling conducted to estimate the potential number
of marine mammal exposures above relevant harassment thresholds: (1)
Maximum design, including one difficult-to-drive pile, and (2) standard
design with no difficult-to-drive pile included.
The two piling scenarios were modeled separately to conservatively
assess the potential impacts of each. The two scenarios modeled were:
(1) The ``maximum design'' consisting of 15 piles requiring ~4,500
strikes per pile (per 24 hours), and one difficult-to-drive pile
requiring ~8,000 strikes (per 24 hours)
(2) The ``standard design'' consisting of 16 piles requiring ~4,500
strike per pile (per 24 hours).
Representative hammering schedules of increasing hammer energy with
increasing penetration depth were modeled, resulting in generally
higher intensity sound fields as the hammer energy and penetration
increases (Table 6).
Table 6--Hammer Energy Schedule For Monopile Installation
Standard pile  Difficult pile       Pile
Energy level (kilojoule[kJ])                     strike count    strike count     penetration
(4,500 total)   (8,000 total)        (m)
1,000...........................................................             500             800             0-6
1,500...........................................................           1,000           1,200          6-23.5
2,500...........................................................           1,500           3,000         23.5-41
4,000...........................................................           1,500           3,000           41-45
Monopiles were assumed to be vertical and driven to a penetration
depth of 45 m. While pile penetration across the sites would vary, this
value was chosen as a reasonable maximum penetration depth. All
acoustic modeling was performed assuming that only one pile is driven
at a time.
Additional modeling assumptions for the monopiles were as follows:
One pile installed per day.
10.97-m steel cylindrical piling with wall thickness of 10
Impact pile driver: IHC S-4000 (4000 kilojoules (kJ) rated
energy; 1977 kilonewtons (kN) ram weight).
Helmet weight: 3234 kN.
As described in the Comments and Responses section, sound fields
produced during monopile installation were estimated by first computing
the force at the top of each pile associated with typical hammers using
the GRLWEAP 2010 wave equation model (GRLWEAP, Pile Dynamics 2010),
which produced forcing functions. The source signatures of each
monopile were predicted using the TDFD PDSM to compute the monopile
vibrations caused by hammer impact. To accurately calculate propagation
metrics of an impulsive sound, a time-domain representation of the
pressure wave in the water was used. To model the sound waves
associated with the monopile vibration in an acoustic propagation
model, the monopiles are represented as vertical arrays of discrete
point sources. The discrete sources are distributed throughout the
length of the monopile below the sea surface and into the sediment with
vertical separation of 3 m. The length of the acoustic source is
adjusted for the site-specific water depth and penetration at each
energy level, and the section length of the monopile within the
sediment is based on the monopile hammering schedule (Table 6).
Pressure signatures for the point sources are computed from the
particle velocity at the monopile wall up to a maximum frequency of
2,048 Hz. This frequency range is suitable because most of the sound
energy generated by impact hammering of the monopiles is below 1 kHz.
As described previously, to calculate predicted propagation of
sounds produced during impact pile driving of monopiles below 2 kHz,
JASCO used it's FWRAM, which is an acoustic model based on the wide-
angle parabolic equation (PE) algorithm (Collins 1993). FWRAM computes
tracing model is described as an approximation of a given source by a
fan of beams through the medium. Then, the quantities of interest
(e.g., acoustic pressure at different ranges) are computed at a
specified location by summing the contribution of each of the
Two locations within the SFWF were selected to provide
representative propagation and sound fields for the project area (see
Figure 1 in SFWF COP, Appendix J1). The two locations were selected to
span the region from shallow to deeper water and varying distances to
dominant bathymetric features (i.e., slope and shelf break). Water
depth and environmental characteristics (e.g., bottom-type) are similar
throughout the SFWF, and therefore minimal differences were found in
sound propagation results for the two sites (Denes et al., 2018).
Propagation modeling also incorporated two different sound velocity
profiles (based on in situ measurements of temperature, salinity, and
pressure within the water column) to account for variations in the
acoustic propagation conditions between summer and winter. Estimated
impact pile driving of monopiles schedules (Table 6) were used to
calculate the SEL sound fields at different points in time during
monopile installation.
The sound propagation modeling incorporated site-specific
environmental data that describes the bathymetry, sound speed in the
water column, and seabed geoacoustics in the construction area. Sound
level estimates were calculated from three-dimensional sound fields and
then at each horizontal sampling range, the maximum received level that
occurs within the water column is used as the received level at that
range. These maximum-over-depth (Rmax) values are then
compared to predetermined threshold levels to determine acoustic ranges
to Level A harassment and Level B harassment isopleths. However, the
ranges to an isopleth typically differ among radii from a source, and
might not be continuous because sound levels may drop below threshold
at some ranges and then exceed threshold at farther ranges. To minimize
the influence of these inconsistencies, 5 percent of such footprints
were excluded from the model data. The resulting range,
R95percent, is used because, regardless of the shape of the
maximum-over-depth footprint, the predicted range encompasses at least
95 percent of the horizontal area that would be exposed to sound at or
above the specified threshold. The difference between Rmax
and R95percent depends on the source directivity and the
heterogeneity of the acoustic environment. R95percent
excludes ends of protruding areas or small isolated acoustic foci not
representative of the nominal ensonified zone (see Figure 12; SFWF COP
Appendix J1).
The modeled source spectrum is provided in Figure 7 of the SFWF COP
(Appendix J1). The dominant energy for both impact pile-driving
scenarios (``maximum'' and ``standard'') is below 1000 Hz. Please see
Appendix J1 of the SFWF COP for further details on the modeling
methodology (Denes et al., 2020a).
South Fork Wind will employ a noise mitigation system during all
impact pile driving of monopiles. Bubble curtains, one type of noise
mitigation technology, are sometimes used to decrease the sound levels
radiated from a source. Bubbles create a local impedance change that
acts as a barrier to sound transmission. The size of the bubbles
determines their effective frequency band, with larger bubbles needed
to attenuate lower frequencies. There are a variety of bubble curtain
systems, confined or unconfined, and some with encapsulated bubbles or
panels. Attenuation levels also vary by type of system, frequency band,
and location. Small bubble curtains have been shown to reduce sound
levels, but effective attenuation is highly dependent on depth of
water, current, and configuration and operation of the curtain (Austin,
Denes, MacDonnell, & Warner, 2016; Koschinski & L[uuml]demann, 2013).
Bubble curtains vary in terms of the sizes of the bubbles. Those with
larger bubbles tend to perform a bit better and more reliably,
particularly when deployed with two separate rings (i.e., dBBC)
(Bellmann, 2014; Koschinski & L[uuml]demann, 2013; Nehls, Rose,
Diederichs, Bellmann, & Pehlke, 2016).
Encapsulated bubble systems (e.g., Hydro Sound Dampers (HSDs)), can
be effective within their targeted frequency ranges, e.g., 100-800 Hz,
and when used in conjunction with a bubble curtain appear to create the
greatest attenuation. The literature presents a wide array of observed
attenuation results for bubble curtains. The variability in attenuation
levels is the result of variation in design, as well as differences in
site conditions and difficulty of properly installing and operating in-
water attenuation devices. A California Department of Transportation
(CalTrans) study tested several systems and found that the best
attenuation systems resulted in 10-15 dB of attenuation (Buehler et
al., 2015). Similarly, D[auml]hne et al. (2017) found that single BBCs
that reduced sound levels by 7-10 dB reduced the overall sound
level by ~12 dB when combined with a dBBC for 6-m steel monopiles in
the North Sea. Bellmann et al. (2020) provide a review of the efficacy
of using bubble curtains (both single and double) as noise abatement
systems in the German EEZ of the North and Baltic Seas. For 8-m
diameter monopiles, single BBCs achieved an average of 11-dB broadband
noise reduction (Bellmann et al., 2020). In modeling the sound fields
for South Fork Wind's activities, hypothetical broadband attenuation
levels of 0-, 6-, 10-, 12-, and 15-dB were modeled to gauge the effects
on the ranges to isopleths given these levels of attenuation. Although
five attenuation levels (and associated ranges) are provided, South
Fork Wind anticipates that the use of a noise mitigation system will
produce field measurements of the ranges to the Level A harassment and
Level B harassment isopleths that accord with those modeled assuming
10-dB attenuation. To account for variability, ensure harassment zone
sizes are no larger than those assumed in this analysis, and ensure
that sound levels are reduced to the lowest level practicable, South
Fork Wind is required to employ an additional noise mitigation device
if using a single BBC. Alternatively, a dBBC may be used without use of
additional noise mitigation equipment.
The acoustic thresholds for impulsive sounds (such as impact pile
driving) contained in the Technical Guidance (NMFS, 2018) were
presented as dual metric acoustic thresholds using both
SELcum and SPLpeak (Table 5). 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.
Tables 7 and 8 shows the modeled acoustic ranges to the Level A
harassment isopleths, with 0, 6 10, 12, and 15-dB sound attenuation
incorporated. For the peak level, the greatest ranges expected within a
given hearing group are shown, typically occurring at the highest
hammer energy (Table 7). The SELcum Level A harassment
threshold is the only metric that is affected by the number of strikes
within a 24-hour period; therefore, it is only this acoustic threshold
that is associated with differences in range estimates between the
standard scenario and the difficult-to drive pile scenario (Table 8).
The maximum ranges for SPLpeak are equal for both scenarios
because this metric is used to define characteristics of a single
impulse and does vary based on the number of strikes (Denes et al.,
2020a). The radial ranges shown in Tables 7 and 8 are the mean ranges
from the piles, averaged between the two modeled locations and between
summer and winter sound velocity profiles.
Table 7--Mean Acoustic Range (R95%) to Level A Peak Sound Pressure Level (SPLpeak) Harassment Isopleths for Marine Mammals Due to Impact Pile Driving of
Monopiles
Threshold                              Mean range (m) to isopleth
SPLpeak (dB re -------------------------------------------------------------------------------
Marine mammal hearing group                 1 [micro]Pa)        0 dB            6 dB            10 dB           12 dB           15 dB
attenuation     attenuation     attenuation     attenuation     attenuation
Low-frequency cetaceans.................................             219              87              22               9               7               2
Mid-frequency cetaceans.................................             230               8               2               1               1               1
High-frequency cetaceans................................             202           1,545             541             243             183             108
Phocid pinnipeds........................................             218             101              26              12               8               2
dB re 1 [micro]Pa = decibel referenced to 1 micropascal.
Table 8--Mean Acoustic Range (R95%) to Level A Sound Exposure Level (SELcum) Harassment Isopleths for Marine Mammals Due to Impact Pile Driving of a
Standard Monopile (S; 4,500 Strikes *) and a Difficult-to-Drive-Monopile (D; 8,000 Strikes *)
Mean range (m) to isopleth
Threshold SELcum ---------------------------------------------------------------------------------------------------
Marine mammal hearing group         (dB re 1       0 dB attenuation    6 dB attenuation    10 dB attenuation   12 dB attenuation   15 dB attenuation
[micro]Pa\2\s)  ---------------------------------------------------------------------------------------------------
S         D         S         D         S         D         S         D         S         D
Low-frequency cetaceans...........               183    16,416    21,941     8,888    11,702     6,085     7,846     5,015     6,520     3,676     4,870
Mid-frequency cetaceans...........               185       107       183        43        59        27        32        27        26        26        26
High-frequency cetaceans..........               155     9,290    13,374     4,012     6,064     2,174     3,314     2,006     2,315       814     1,388
Phocid pinnipeds..................               185     3,224     4,523     1,375     2,084       673     1,080       437       769       230       415
dB re 1 [micro]Pa\2\s = decibel referenced to 1 micropascal squared second.
* Approximation.
Table 9 shows the acoustic ranges to the Level B harassment
isopleth with no attenuation, 6-, 10-, 12-, and 15-dB sound attenuation
incorporated. Acoustic propagation was modeled at two representative
sites in the SFWF, as described above. The radial ranges shown in Table
8 are the mean ranges to the Level B harassment isopleth, derived by
averaging the R95percent to the Level B harassment threshold
for summer and winter (see Appendix P2 of the SFWF COP for more
details). The range estimated assuming 10-dB attenuation (4,684 m) was
used to identify the extent of the Level B harassment zone for impact
pile driving of monopiles.
Table 9--Mean Acoustic Ranges (R95percent) to Level B Harassment Isopleth (SPLrms) Due to Impact Pile Driving of
Threshold SPLrms (dB re 1    -------------------------------------------------------------------------------
[micro]Pa)                  0 dB            6 dB            10 dB           12 dB           15 dB
160.............................          11,382           6,884           4,684           4,164           3,272
Impact Pile Driving of Monopiles: Exposure-Based Ranges
Modeled acoustic ranges to harassment isopleths may overestimate
the actual ranges at which animals receive exposures meeting the Level
A (SELcum) harassment threshold criterion. Therefore, such
ranges are not realistic, particularly for accumulating metrics like
SELcum. Applying animal movement and behavior (Denes et al.,
2020c) within the propagated noise fields provides the exposure range,
which results in a more realistic indication of the ranges at which
acoustic thresholds are met. For modeled animals that have received
enough acoustic energy to exceed a given threshold, the exposure range
for each animal is defined as the closest point of approach (CPA) to
the source made by that animal while it moved throughout the modeled
sound field, accumulating received acoustic energy. The resulting
exposure range for each species is the 95th percentile of the CPA
ranges for all animals that exceeded threshold levels for that species
(termed the 95 percent exposure range (ER95percent)).
Notably, the ER95percent are species-specific rather than
categorized only by hearing group, which affords more biologically-
relevant data (e.g., dive durations, swim speeds, etc.) to be
considered when assessing impact ranges. The ER95percent
values for SELcum provided in Table 10 are smaller than the
acoustic ranges calculated using propagation modeling alone (Table 7
and 8). Please see the Estimated Take section below and Appendix P1 of
the SFWF COP for further detail on the acoustic modeling methodology.
The ER95percent ranges assuming 10-dB attenuation for a
difficult-to-drive pile were used to determine the Level A harassment
zones for impact pile driving of monopiles.
Table 10--Exposure-Based Ranges (ER95percent) to Level A Harassment Sound Exposure Level (SELcum) Harassment Isopleths Due to Impact Pile Driving of a Standard Monopile (S; 4,500 Strikes *)
and a Difficult-to-Drive-Monopile (D; 8,000 Strikes *)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
ER95% to SELcum isopleths (m)
Species                                 0 dB attenuation          6 dB attenuation          10 dB attenuation         12 dB attenuation         15 dB attenuation
S            D            S            D            S            D            S            D            S            D
Low-Frequency Cetaceans
Fin whale.....................................................        5,386        6,741        2,655        2,982        1,451        1,769          959        1,381          552          621
Minke whale...................................................        5,196        6,033        2,845        2,882        1,488        1,571          887          964          524          628
Sei whale.....................................................        5,287        6,488        2,648        3,144        1,346        1,756        1,023        1,518          396          591
Humpback whale................................................        9,333       11,287        5,195        5,947        3,034        3,642        2,450        2,693        1,593        1,813
North Atlantic right whale....................................        4,931        5,857        2,514        3,295        1,481        1,621          918        1,070          427          725
Mid-Frequency Cetaceans
Sperm whale...................................................            0            0            0            0            0            0            0            0            0            0
Atlantic spotted dolphin......................................            0            0            0            0            0            0            0            0            0            0
Atlantic white-sided dolphin..................................           20            6           20            6            0            0            0            0            0            0
Common dolphin................................................            0            0            0            0            0            0            0            0            0            0
Risso's dolphin...............................................           24           13           24            0            0            0            0            0            0            0
Bottlenose dolphin............................................           13           13            0            0            0            0            0            0            0            0
Long-finned pilot whale.......................................            0            0            0            0            0            0            0            0            0            0
High-Frequency Cetaceans
Harbor porpoise...............................................        2,845        3,934          683          996           79          365           26           39           21           26
Pinnipeds in Water
Gray seal.....................................................        1,559        1,986          276          552           46          117            0           21            0           21
Harbor seal...................................................        1,421        2,284          362          513           22           85           22            0           21            0
Cofferdam Installation and Removal
Similar to cylindrical piles, sheet piles are a distributed
acoustic source that can be treated as a linear array of point sources.
The acoustic source modeling of vibratory driving of sheet piles was
conducted following the same steps used to model impact pile driving.
An American Pile-driving Equipment APE Model 200T with Model 200
Universal Clamp was modeled driving a19.5-meter-long (64-foot-long),
0.95 cm (\3/8\ in) thick, Z-type sheet pile 9 m (30 feet) into the
sediment in 9 m (30 ft) of water. The forcing function was modeled for
a single cycle of the vibrating hammer using GRLWEAP 2010 wave equation
model (GRLWEAP, Pile Dynamics 2010). The finite difference (FD) model
was used to compute the resulting pile vibrations from the stress wave
that propagates down the sheet pile. The radiated sound waves were
modeled as discrete point sources over the 18 m (60 ft) of the pile in
the water and sediment (9 m [30 ft] water depth, 9 m [30 ft]
penetration) with a vertical separation of 10 cm. The source level
spectrum for vibratory pile driving of a sheet pile for a cofferdam at
the export cable landfall site is shown in Figure 9 in Denes et al.
(2020a).
Underwater sound propagation (i.e., transmission loss) as a
function of range from each point source was modeled at one
construction site using JASCO's Marine Operations Noise Model (MONM).
MONM computes received sound energy, the sound exposure level (SEL),
for directional sources. MONM uses a wide-angle parabolic equation
solution to the acoustic wave equation (Collins 1993) based on a
version of the U.S. Naval Research Laboratory's Range-dependent
Acoustic Model (RAM), which has been modified to account for a solid
seabed (Zhang and Tindle 1995). The parabolic equation method has been
extensively benchmarked and is widely employed in the underwater
acoustics community (Collins et al. 1996). MONM's predictions have been
validated against experimental data from several underwater acoustic
measurement programs conducted by JASCO (Hannay and Racca 2005, Aerts
et al. 2008, Funk et al. 2008, Ireland et al. 2009, O'Neill et al.
2010, Warner et al. 2010, Racca et al. 2012a, Racca et al. 2012b). MONM
accounts for the additional reflection loss at the seabed due to
partial conversion of incident compressional waves to shear waves at
the seabed and sub-bottom interfaces, and it includes wave attenuations
in all layers. MONM incorporates site-specific environmental
properties, such as bathymetry, underwater sound speed as a function of
depth, and a geoacoustic profile the seafloor. MONM treats frequency
dependence by computing acoustic transmission loss at the center
frequencies of 1/3-octave-bands. At each center frequency, the
transmission loss is modeled as a function of depth and range from the
source. Composite broadband received SELs are then computed by summing
the received 1/3-octave-band levels across the modeled frequency range.
For computational efficiency, MONM and similar models such as PE-
RAM, do not track temporal aspects of the propagating signal (as
opposed to the models used for impact pile driving that can output
time-domain pressure signals). It is the total sound energy
transmission loss that is calculated. For our purposes, that is
equivalent to propagating the SEL acoustic metric. For continuous,
steady-state signals SPL is readily obtained from the SEL.
Removal of the cofferdam using a vibratory extractor is expected to
be acoustically comparable to installation activities. No noise
mitigation system will be used during vibratory piling. Summaries of
the maximum ranges to Level A harassment isopleths and the Level B
harassment isopleth resulting from propagation modeling of vibratory
pile driving are provided in Table 11. Peak thresholds were not reached
for any marine mammal hearing group.
The large range to the Level B harassment isopleth resulting from
vibratory piling installation and removal is, in part, a reflection of
the threshold set for behavioral disturbance from a continuous noise
(i.e., 120 dB rms). In addition (as discussed in the Comments and
Responses section), the source level (SPL of 180 dB re 1 [micro]Pa at
31 m) for installation of sheet piles for the cofferdam is likely an
overestimate but was considered acceptable for the following reasons:
(1) The source level (SPL 160-165 dB re 1 [micro]Pa measured at 10 m)
for vibratory pile driving of sheet piles cited in Caltrans (2016,
2020) and provided in NOAA's Pile Driving Noise Calculator spreadsheet
(Caltrans 2012, 2015) (available at https://media.fisheries.noaa.gov/2021-02/SERO%20Pile%20Driving%20Noise%20Calculator_for%20web.xlsx?null)
is based on measurements of a small number of piles for which vibratory
pile driving was only used to set the pile prior to impact pile driving
to the final desired penetration depth, whereas South Fork Wind would
be vibratory pile driving sheet piles to the full extent of the desired
penetration depth, and (2) the pile (and vibratory hammer) will
potentially encounter more resistance with depth and, therefore,
require more hammer energy, during installation of the cofferdam
because the piles will be driven to a deeper depth than those included
in Caltrans (2016, 2020). Finally, Level B harassment is highly
contextual for different species and the range to the isopleth does not
represent a definitive impact zone or a suggested mitigation zone;
rather, the information serves as the basis for assessing potential
impacts within the context of the project and potentially exposed
Table 11--Ranges to Level A Cumulative Sound Exposure Level (SELcum) Harassment Isopleth and Level B Root-Mean-
Square Sound Pressure Level (SPLrms) Harassment Isopleth Due to 18 Hours of Vibratory Pile Driving \1\
Level B
Level A        Maximum range    harassment     Maximum range
harassment     (m) to level A     threshold    (m) to level B
Marine mammal hearing group            threshold SELcum    harassment     SPLrms (dB re    harassment
(dB re 1         isopleth      1 [micro]Pa)      isopleth
[micro]Pa \2\s)
Low-frequency cetaceans......................                199           1,470             120          36,766
Mid-frequency cetaceans......................                198               0             120          36,766
High-frequency cetaceans.....................                173              63             120          36,766
Phocid pinnipeds.............................                201             103             120          36,766
\1\ Although South Fork Wind may conduct a combination of impact and vibratory pile driving to install a casing
pipe alternative to the cofferdam, mitigation and monitoring will be implemented based on ranges presented
dB re 1 [micro]Pa = decibel referenced to 1 micropascal; [micro]Pa\2\s = decibel referenced to 1 micropascal
squared second.
Ranges to Level A harassment isopleths for HRG equipment planned
for use and all marine mammal functional hearing groups were modeled
using the NMFS User Spreadsheet and NMFS Technical Guidance (2018),
which provides a conservative approach to exposure estimation. However,
sources that project a narrower beam, often in frequencies above 10 kHz
directed at the seabed, are expected to have smaller distances to
isopleths and less horizontal propagation due to the directionality of
the source and faster attenuation rate of higher frequencies. Narrow
beamwidths allow these HRG sources to be highly directional, focusing
energy in the vertical direction and minimizing horizontal propagation,
which greatly reduces the possibility of direct path exposure to
receivers (i.e., marine mammals) from sounds emitted by these sources.
NMFS has developed a user-friendly methodology for determining the
sound pressure level (SPLrms) at the 160-dB isopleth for the
purposes of estimating the extent of Level B harassment isopleths
associated with HRG survey equipment (NMFS, 2020). This methodology
incorporates frequency-dependent absorption and some directionality to
refine estimated ensonified zones. South Fork Wind used NMFS'
methodology with additional modifications to incorporate a seawater
absorption formula and account for energy emitted outside of the
primary beam of the source. Therefore, for sources with beamwidths less
than 180[deg], ranges to the Level B harassment isopleth were
calculated following NMFS's methodology (NMFS, 2020) to account for the
influence of beamwidth and frequency on the horizontal propagation of
these sources. For sources that operate with different beam widths, the
maximum beam width was used (see Table 2). The lowest frequency of the
source was used when calculating the absorption coefficient (Table 2).
NMFS considers the data provided by Crocker and Fratantonio (2016)
to represent the best available information on source levels associated
with HRG equipment and, therefore, recommends that source levels
provided by Crocker and Fratantonio (2016) be incorporated in the
method described above to estimate ranges to the Level A harassment and
Level B harassment isopleths. In cases when the source level for a
specific type of HRG equipment is not provided in Crocker and
Fratantonio (2016), NMFS recommends that either the source levels
provided by the manufacturer be used, or, in instances where source
levels provided by the manufacturer are unavailable or unreliable, a
proxy from Crocker and Fratantonio (2016) be used instead. Table 2
shows the HRG equipment types that may be used during the construction
surveys and the sound levels associated with those HRG equipment types.
Results of modeling using the methodology described above indicated
that, of the HRG equipment planned for use by South Fork Wind that has
the potential to result in Level B harassment of marine mammals, sound
produced by the Applied Acoustics Dura-Spark UHD sparkers and GeoMarine
Geo-Source sparker would propagate furthest to the Level B harassment
isopleth (141 m; Table 12). For the purposes of the exposure analysis,
it was conservatively assumed that sparkers would be the dominant
acoustic source for all survey days. Thus, the range to the isopleth
corresponding to the threshold for Level B harassment for sparkers (141
m) was used as the basis of the take calculation for all marine
Table 12--Range to Weighted Level A Harassment and Unweighted Level B Harassment Isopleths for Each HRG Sound Source or Comparable Sound Source Category
for Marine Mammal Hearing Groups
Range to level A harassment isopleth (m)                     Range to level
--------------------------------------------------------------------------------  B harassment
Source                                                                                isopleth (m)
LF (SELcum      MF (SELcum      HF (SELcum      HF (SPL0-pk     PW (SELcum   ---------------
threshold)      threshold)      threshold)      threshold)      threshold)      All species
Shallow SBPs
ET 216 CHIRP............................................              <1              <1             2.9               -               0              12
ET 424 CHIRP............................................               0               0               0               -               0               4
ET 512i CHIRP...........................................               0               0              <1               -               0               6
GeoPulse 5430...........................................              <1              <1            36.5               -              <1              29
TB CHIRP III............................................             1.5              <1            16.9               -              <1              54
Medium SBPs
AA Triple plate S-Boom (700/1,000 J)....................              <1               0               0             4.7              <1              76
AA, Dura-spark UHD (500 J/400 tip)......................              <1               0               0             2.8              <1             141
AA, Dura-spark UHD 400+400..............................              <1               0               0             2.8              <1             141
GeoMarine, Geo-Source dual 400 tip sparker..............              <1               0               0             2.8              <1             141
- = not applicable; [micro]Pa = micropascal; AA = Applied Acoustics; Chirp = Compressed High-Intensity Radiated Pulse; dB = decibels; ET =EdgeTech; HF =
high-frequency; J = joules; LF = low-frequency; MF = mid-frequency; PW = Phocids in water; re = referenced to; SBP = sub-bottom profiler; SELcum =
cumulative sound exposure level in dB re 1 [micro]Pa\2\s; SPL0-pk = zero to peak sound pressure level in dB re 1 [micro]Pa; TB = teledyne benthos; UHD
= ultra-high definition; USBL = ultra-short baseline.
Marine Mammal Occurrence
This section provides information about the presence, density, or
group dynamics of marine mammals that will inform the take
calculations. 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, 2020). 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 of those models, 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 updates leads to
the conclusion that these modeled densities represent the best
scientific evidence available. Marine mammal density estimates in the
SFWF (animals/km\2\) were obtained using these model results (Roberts
et al., 2016, 2017, 2018, 2020). As noted in the Comments and Responses
section, the updated models incorporate additional sighting data,
including sightings from the NOAA Atlantic Marine Assessment Program
for Protected Species (AMAPPS) surveys from 2010-2016, which included
some aerial surveys over the RI/MA WEAs (NEFSC & SEFSC, 2011a, 2011b,
2012, 2014a, 2014b, 2015, 2016). In addition, the 2020 update to the
NARW density model (Roberts et al., 2020) includes, for the first time,
data from the 2011-2015 surveys of the MA and RI/MA WEAs (Kraus et al.
2016) as well as the 2017-2018 continuation of those surveys, known as
the Marine Mammal Surveys of the Wind Energy Areas (MMS-WEA) (Quintana
et al., 2018).
Densities of marine mammals and their subsequent exposure risk are
different for the SFWF area (where impact pile driving of monopiles
will occur), the nearshore export cable landing area (where vibratory
pile driving will occur), and the construction survey area. Therefore,
density blocks (Roberts et al., 2016; Roberts et al., 2018) specific to
each activity area were selected for evaluating the potential numbers
of take for the 15 assessed species. The Denes et al. (2020b) model
analysis utilized NARW densities from the most recent survey period,
2010-2018, as suggested by Roberts et al. (2020).
Monopile Installation
Mean monthly densities for all animals were calculated using a 60
km (37.3 mi) square centered on SFWF and overlaying it on the density
maps from Roberts et al. (2016, 2017, 2018, 2020). The relatively large
area selected for density estimation encompasses and extends beyond the
estimated ranges to the isopleth corresponding to Level B harassment
(with no attenuation, as well as with 6, 10, 12 and 15-dB sound
attenuation) for all hearing groups using the unweighted threshold of
160 dB re 1 [mu]Pa (rms) (Table 9). Please see Figure 3 in the SFWF COP
(Appendix P2) for an example of a density map showing Roberts et al.
(2016, 2017, 2018, 2020) density grid cells overlaid on a map of the
SFWF.
The mean density for each month was determined by calculating the
unweighted mean of all 10 x 10 km (6.2 x 6.2 mi) grid cells partially
or fully within the buffer zone polygon. Mean values from the density
maps were converted from units of abundance (animals/100 km\2\ [38.6
miles\2\]) to units of density (animals/km\2\). Densities were computed
for the months of May to December to coincide with planned impact pile
driving of monopile activities (as described above, no impact pile
driving of monopiles may occur from December (with caveats) through
April). In cases where monthly densities were unavailable, annual mean
densities (e.g., pilot whales) and seasonal mean densities (e.g., all
seals) were used instead. Table 13 shows the monthly marine mammal
density estimates for each species incorporated in the exposure
modeling analysis. To obtain conservative exposure estimates, South
Fork Wind used the maximum of the mean monthly (May to December)
densities for each species to estimate the number of individuals of
each species exposed to sound above Level A harassment and Level B
harassment thresholds. The maximum densities applied are denoted by an
asterisk.
Table 13--Estimated Densities (Animals/km-\2\) Used for Modeling Marine Mammal Exposures Incidental to Monopile Installation Within South Fork Wind Farm
Monthly density (animals km-\2\)
Common name                           ---------------------------------------------------------------------------------------
May        Jun        Jul        Aug        Sep        Oct        Nov        Dec
Fin whale.......................................................    0.00201    0.00219  * 0.00264    0.00251    0.00217    0.00145    0.00102    0.00105
Minke whale.....................................................  * 0.00163    0.00143    0.00047    0.00026    0.00027    0.00049    0.00022    0.00032
Sei whale.......................................................  * 0.00019    0.00013    0.00003    0.00002    0.00003    0.00000    0.00001    0.00001
Humpback whale..................................................    0.00133    0.00148    0.00069    0.00094  * 0.00317    0.00156    0.00042    0.00061
North Atlantic right whale......................................  * 0.00154    0.00011    0.00002    0.00001    0.00001    0.00005    0.00029    0.00151
Blue whale......................................................                                         * 0.00001
Sperm whale.....................................................    0.00002    0.00008  * 0.00031    0.00024    0.00010    0.00007    0.00007    0.00001
Atlantic white-sided dolphin....................................  * 0.03900    0.03600    0.02500    0.01300    0.01500    0.02200    0.02100    0.02800
Atlantic spotted dolphin........................................    0.00012    0.00016    0.00034    0.00041    0.00051  * 0.00058    0.00037    0.00007
Bottlenose dolphin..............................................    0.00496    0.01800    0.03700    0.03800  * 0.04000    0.02000    0.00962    0.00846
Pilot whales \1\................................................                                         * 0.00596
Risso's dolphin.................................................    0.00005    0.00005    0.00018  * 0.00026    0.00015    0.00005    0.00009    0.00019
Common dolphin..................................................    0.04400    0.04600    0.04300    0.06200    0.10200    0.12800    0.09800  * 0.20400
Harbor porpoise.................................................  * 0.03800    0.00236    0.00160    0.00172    0.00161    0.00399    0.02400    0.02300
Gray seal.......................................................  * 0.03900    0.02600    0.00874    0.00357    0.00529    0.00955    0.00630    0.03400
Harbor seal.....................................................  * 0.03900    0.02600    0.00874    0.00357    0.00529    0.00955    0.00630    0.03400
* Denotes the highest monthly density estimated.
\1\ Long- and short-finned pilot whales are grouped together to estimate the total density of both species.
Marine mammal densities in the nearshore export cable landing area
were estimated from the 10 x 10 km habitat density blocks that
contained the anticipated potential locations (separated by 22 km) of
the cofferdam. Monthly marine mammal densities for the potential
construction locations of the cofferdam are provided in Table 14. The
maximum densities (denoted by an asterisk) were incorporated in the
exposure modeling to obtain the most conservative estimates of
potential take by Level A harassment or Level B harassment.
The species listed in each respective density table represent
animals that could be reasonably expected to occur within the Level B
harassment zone, in the months during which the cofferdam could
potentially be installed and extracted (e.g., installation likely
between November and April; removal could occur anytime up to
expiration of the IHA). Several of the outer continental shelf and
deeper water species that appear in the SFWF area are not included in
the cofferdam species list because the densities were zero for those
Table 14--Estimated Densities (Animals/km-\2\) Used for Modeling Marine Mammal Exposures Within the Affected Area and Construction Schedule of the
Cofferdam Installation
Species \1\                               Jan        Feb        Mar        Apr        May        Oct        Nov        Dec
Fin whale.......................................................     0.0001     0.0001     0.0002   * 0.0005     0.0002     0.0002     0.0001     0.0001
Minke whale.....................................................     0.0005   * 0.0008     0.0008     0.0000     0.0000     0.0000     0.0005     0.0005
Sei whale.......................................................     0.0001     0.0001     0.0001     0.0000     0.0000     0.0000     0.0000     0.0001
Humpback whale..................................................   * 0.0002     0.0002     0.0002     0.0000     0.0000     0.0000     0.0000     0.0002
North Atlantic right whale......................................   * 0.0014     0.0014     0.0013     0.0008     0.0003     0.0000     0.0002     0.0008
Atlantic white-sided dolphin....................................     0.0001     0.0000     0.0001     0.0002   * 0.0003     0.0003     0.0003     0.0002
Common dolphin..................................................     0.0003     0.0001     0.0001     0.0003     0.0007     0.0007   * 0.0010     0.0008
Bottlenose dolphin..............................................     0.0694     0.0296     0.0157     0.0474     0.3625   * 0.4822     0.2614     0.0809
Harbor porpoise.................................................     0.0007     0.0005     0.0005     0.0011     0.0007   * 0.0026     0.0003     0.0006
Gray seal.......................................................   * 0.3136     0.3136     0.3136     0.3136     0.3136     0.3136     0.3136     0.3136
Harbor seal.....................................................   * 0.3136     0.3136     0.3136     0.3136     0.3136     0.3136     0.3136     0.3136
* Denotes density used for take estimates.
\1\ Only species with potential exposures are listed.
Densities for construction surveys were combined for the SFWF area
(inter-array cables) and the SFEC using density blocks that encompassed
those areas. The densities used for construction surveys are provided
in Table 15. Average annual, rather than maximum monthly, densities
were estimated to account for spatial variability in the distribution
of marine mammals throughout the SFWF and SFEC and temporal variability
in distribution over the 12-month timeframe during which construction
surveys would occur.
Take Calculation and Estimation
Below is a description of 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 harassment and Level B harassment thresholds as
a result of the planned activities.
JASCO's Animal Simulation Model Including Noise Exposure (JASMINE)
animal movement model was used to predict the probability of marine
mammal exposure to impact pile driving sound generated by monopile
installation. Sound exposure models like JASMINE use simulated animals
(also known as ``animats'') to forecast behaviors of animals in new
situations and locations based on previously documented behaviors of
those animals. The predicted 3D sound fields (i.e., the output of the
acoustic modeling process described earlier) are sampled by animats
using movement rules derived from animal observations. The output of
the simulation is the exposure history for each animat within the
simulation.
The precise location of animats (and their pathways) are not known
prior to a project, therefore, a repeated random sampling technique
(Monte Carlo) is used to estimate exposure probability with many
animats and randomized starting positions. The probability of an animat
starting out in or transitioning into a given behavioral state can be
defined in terms of the animat's current behavioral state, depth, and
the time of day. In addition, each travel parameter and behavioral
state has a termination function that governs how long the parameter
value or overall behavioral state persists in the simulation.
The output of the simulation is the exposure history for each
animat within the simulation, and the combined history of all animats
gives a probability density function of exposure during the project.
Scaling the probability density function by the real-world density of
animals (Table 13) results in the mean number of animats expected to be
exposed over the duration of the project. Due to the probabilistic
nature of the process, fractions of animats may be predicted to exceed
threshold. If, for example, 0.1 animats are predicted to exceed
threshold in the model, that is interpreted as a 10-percent chance that
one animat will exceed a relevant threshold during the project, or
equivalently, if the simulation were re-run ten times, one of the ten
simulations would result in an animat exceeding the threshold.
Similarly, a mean number prediction of 33.11 animats can be interpreted
as re-running the simulation where the number of animats exceeding the
threshold may differ in each simulation but the mean number of animats
over all of the simulations is 33.11. A portion of an individual marine
mammal cannot be taken during a project, so it is common practice to
round mean number animat exposure values to integers using standard
rounding methods. However, for low-probability events it is more
precise to provide the actual values. For this reason, mean number
values are not rounded.
Sound fields were input into the JASMINE model and animats were
programmed based on the best available information to ``behave'' in
ways that reflect the behaviors of the 15 marine mammal species
expected to occur in the project area during the activity. The various
parameters for forecasting realistic marine mammal behaviors (e.g.,
diving, foraging, surface times, etc.) are determined based on the
available literature (e.g., tagging studies). When literature on these
behaviors was not available for a particular species, it was
extrapolated from a similar species for which behaviors would be
expected to be similar to the species of interest. Please refer to the
footnotes on Tables 16 and 17, and Appendix P2 of SFWF COP for a more
detailed description of the species that were used as proxies when data
on a particular species was not available. The parameters used in
JASMINE describe animat movement in both the vertical and horizontal
planes (e.g., direction, travel rate, ascent and descent rates, depth,
bottom following, reversals, inter-dive surface interval). More
information regarding modeling parameters can be found in Denes et al.
(2020b).
The mean numbers of animats that may be exposed to noise exceeding
acoustic thresholds were calculated for two construction schedules, one
representing the most likely schedule, and one representing a more
aggressive, or maximum schedule (Denes et al., 2019). The most likely
schedule assumes that three foundations are installed per week with an
average of one pile installed every other day. The maximum schedule
assumes six monopile foundations are installed per week with one pile
installation per day. Within each of the construction schedules, a
single difficult-to-drive pile was included in the model assumptions to
account for the potential for additional strikes (Denes et al., 2019).
Animats were modeled to move throughout the three-dimensional sound
fields produced by each construction schedule for the entire
construction period. For PTS exposures, both SPLpeak and
SPLcum were calculated for each species based on the
corresponding acoustic criteria. Once an animat is taken within a 24-
hour period, the model does not allow it to be taken a second time in
that same period but rather resets the 24-hour period on a sliding
scale across 7 days of exposure. An individual animat's exposure levels
are summed over that 24-hour period to determine its total received
energy, and then compared to the threshold criteria. Potential
behavioral exposures are estimated when an animat is within the area
ensonified by sound levels exceeding the corresponding thresholds. It
should be noted that the estimated numbers of individuals exceeding any
of the thresholds is conservative because the 24-hour evaluation window
allows individuals to be counted on multiple days (or can be
interpreted as different individuals each 24-hour period) when in the
real world it may in fact be the same individual experiencing repeated
exposures (Denes et al., 2019). Please note that animal aversion was
not incorporated into the JASMINE model runs that were the basis for
the take estimate for any species. See Appendix P2 of the SFWF COP for
more details on the JASMINE modeling methodology, including the
literature sources used for the parameters that were input in JASMINE
to describe animal movement for each species that is expected to occur
in the project area.
In summary, exposures were estimated in the following way:
(1) The characteristics of the sound output from the pile-driving
activities were modeled using the GRLWEAP (wave equation analysis of
pile driving) model and JASCO's TDFD PDSM;
(2) Acoustic propagation modeling was performed within the exposure
model framework using FWRAM and BELLHOP, which combined the outputs of
the source model with the spatial and temporal environmental context
(e.g., location, oceanographic conditions, seabed type) to estimate
sound fields;
(3) Animal movement modeling integrated the estimated sound fields
with species-typical behavioral parameters in the JASMINE model to
estimate received sound levels for the animals that may occur in the
operational area; and
(4) The number of potential exposures above Level A harassment and
Level B harassment thresholds was calculated for each potential piling
scenario (standard, maximum).
All scenarios were modeled with no sound attenuation and 6, 10, 12,
and 15-dB sound attenuation. The results of marine mammal exposure
modeling for the potentially more impactful maximum piling scenarios
are shown in Tables 16 and 17, as these form the basis for authorized
take.
Again, only the estimated Level B harassment exposures for the
maximum design impact pile driving of monopiles schedule are presented
here (Table 17).
BILLING CODE 3510-22-C
Although exposures are presented according to a range of
attenuation levels, take numbers are based on an assumption of 10-dB
attenuation and are shown below in Table 18. South Fork Wind considers
an attenuation level of 10-dB achievable using a dBBC, which is the
most likely noise mitigation technology that will be used during
construction of SFWF. Recently reported in situ measurements during
installation of monopiles (~8 m) for more than 150 WTGs in comparable
water depths (>25 m) and conditions in Europe indicate that attenuation
of 10-dB is readily achieved (Bellmann, 2019; Bellmann et al., 2020)
using single BBCs for noise mitigation. Designed to gather additional
data regarding the efficacy of BBCs, the Coastal Virginia Offshore Wind
(CVOW) pilot project systematically measured noise resulting from the
impact driven installation of two 7.8-m monopiles, one installation
using a dBBC and the other installation using no noise mitigation
system (CVOW, unpublished data). Although many factors contributed to
variability in received levels throughout the installation of the piles
(e.g., hammer energy, technical challenges during operation of the
dBBC), reduction in broadband SEL using the dBBC (comparing
measurements derived from the mitigated and the unmitigated monopiles)
ranged from approximately 9-15 dB. The effectiveness of the dBBC as a
noise mitigation system was found to be frequency-dependent, reaching
maximum efficacy around 1 kHz; this finding is consistent with other
studies (e.g., Bellman, 2014; Bellman et al., 2020). The noise
measurements were incorporated into a dampened cylindrical transmission
loss model to estimate ranges to Level A harassment and Level B
harassment isopleths. The ranges to Level A harassment and Level B
harassment isopleths estimated for the monopile with the dBBC were more
than 90 percent and 74 percent smaller than those estimated for the
unmitigated pile, respectively (CVOW unpublished data).
South Fork Wind conservatively based their exposure modeling on the
maximum piling scenario, including one difficult-to-drive monopile (out
of 16) and a compressed buildout schedule (16 piles installed over 20
days).
In addition, the acoustic modeling scenario represents only that
which produced the largest harassment zones, and does not reflect all
the mitigation measures that must be employed during piling operations
to reduce the ensonified zone or increase mitigation
actions, which may reduce take (see the Mitigation section for
details).
Variability in monthly species densities is not considered in South
Fork Wind's take estimates for impact pile driving of monopiles, which
are based on the highest mean density value for any month for each
species. Given that all monopile installations will potentially occur
within an approximately 30-day timeframe, it is unlikely that maximum
monthly densities would be encountered for all species.
Finally, start delays and shutdowns of monopile installation are
not considered in the exposure modeling parameters for monopile
driving. However, South Fork Wind must delay impact pile driving of
monopiles if a NARW is observed at any distance prior to initiating
pile driving to avoid take, and if any other marine mammal is observed
entering or within the respective clearance zone during the clearance
period. If monopile installation has already commenced, South Fork Wind
is required to shutdown if a NARW is sighted at any distance or
detected via PAM within 2 km of the monopile location, and if any other
marine mammal enters its respective shutdown zone (unless South Fork
Wind and/or its contractor determines shutdown is not practicable due
to an imminent risk of injury or loss of life to an individual, or risk
of damage to a vessel that creates risk of injury or loss of life for
individuals). There are two scenarios, approaching pile refusal and
pile instability, where this imminent risk could be a factor. These
scenarios are considered unlikely and it is expected that shutdowns
will predominantly be practicable during operations. See Mitigation
section for shutdown procedural details.
Although exposure modeling for monopile installations indicated
that take by Level A harassment (PTS) is only expected for a three
species of baleen whales (fin whale, minke whale, and humpback whale),
South Fork Wind requested, and NMFS has authorized, take, by Level A
harassment, of one sei whale based on (1) rare observations of sei
whales in/near the Lease Area during prior monitoring efforts, and (2)
difficulty distinguishing fin and sei whales at sea (observers
sometimes report a fin/sei complex). In addition, South Fork Wind
requested authorization of take, by Level B harassment, equal to the
mean group size for several species, based on the following: Seals,
Herr et al., (2009); long-finned pilot whale, Kenney and Vigness-Raposa
(2010); sperm whale, and Risso's dolphin, Barkaszi and Kelly (2018).
NMFS generally agrees that this approach is appropriate in cases where
instantaneous exposure is expected to result in harassment (e.g., Level
B harassment) and calculated take estimates are either zero or less
than the group size. Upon further review of scientific literature, NMFS
has increased take, by Level B harassment, of long-finned pilot whales
from 12 to 20, based on the largest reported group size (n=20; CETAP,
1982). Similarly, NMFS increased take, by Level B harassment, of
Atlantic spotted dolphins from 2 to 13 based on Barkaski and Kelly
(2018); this group size is similar to average group size estimated from
observations of Atlantic spotted dolphins within or near the project
area (n=10), as reported in Smultea (2020). Common dolphins are
frequently sighted in the project area, although the average group size
varies by season (AMAPPS, 2021). During previous monitoring efforts in
or near the SFWF and SFEC, the average group size ranged from 9.6 (CSA,
2021) to 35 (AMAPPS 2021). To account for the frequency of occurrence
in the project area, NMFS conservatively increased take of common
dolphins, by Level B harassment, from 197 to 560 by multiplying the
largest reported group size (35; AMAPPS, 2021) by the number of days on
which impact pile driving of monopiles may occur (n=16). AMAPPS (2021)
reports the largest average group size for bottlenose dolphins (n=21.6)
among the literature reviewed (DoN, 2017; Smultea, 2020; CSA, 2021;
AMAPPS, 2021). NMFS increased take, by Level B harassment, of
bottlenose dolphins from 43 to 346 by multiplying group size (n=21.6;
AMAPPS, 2021) by the number of days on which monopile installation may
occur (n=16). Finally, as described in the Comments and Responses and
Changes from Proposed to Final IHA sections, one take, by Level B
harassment, of a blue whale was originally proposed for authorization.
However, given the lack of observations of blue whales within or near
the project area and the species' preference for deeper water and
bathymetric features such as continental shelf edges, NMFS has
determined that the potential for Level B harassment for this species
is de minimus and NMFS has not authorized take of a blue whale, by
Level B harassment. Please see Table 18 for the number of takes
proposed and authorized, by species, incidental to impact pile driving
of monopiles.
Table 18--Proposed and Authorized Level A Harassment and Level B Harassment Take of Marine Mammals Resulting
From Impact Pile Driving of Up to 16, 11-m Monopiles With Inclusion of a Single Difficult-To-Drive Pile at South
Fork Wind Farm Assuming 10-dB Broadband Sound Attenuation
Proposed take \2\              Authorized take \3\
Abundance \1\ ---------------------------------------------------------------
Species/stock              estimate         Level A         Level B         Level A         Level B
harassment      harassment      harassment      harassment
Fin whale.......................           6,802               1               6               1               6
Minke whale.....................          21,968               1              10               1              10
Sei whale.......................           6,292            1(0)               1               1               1
Humpback whale..................           1,396               4               8               4               8
North Atlantic right whale......             368               0               4               0               4
Sperm whale.....................           4,349               0            3(0)               0               3
Long-finned pilot whale.........          39,215               0               2               0              20
Atlantic spotted dolphin........          39,921               0               2               0              13
Atlantic white-sided dolphin....          93,233               0             107               0             107
Common dolphin..................         172,974               0             197               0             560
Risso's dolphin.................          35,215               0           30(1)               0              30
Bottlenose dolphin..............          62,851               0              43               0             346
Harbor porpoise.................          95,543               0              78               0              78
Gray seal.......................          27,300               0              60               0              60
Harbor seal.....................          61,336               0              54               0              54
\1\ The best available abundance estimates are derived from the NMFS' 2021 Draft SARs (Hayes et al., 2021). NMFS
stock abundance estimate for gray seals in Table 3 applies to U.S. population only; actual stock abundance is
approximately 451,431.
\2\ Parentheses denote animal exposure model estimates. For species with no modeled exposures for Level A
harassment or Level B harassment, proposed takes are based on mean group sizes (e.g., sei whale, long-finned
pilot whale: Kenney and Vigness-Raposa (2010); sperm whale, Risso's dolphin: Barkaszi and Kelly, (2018)).
\3\ Authorized take is based on largest group size reported from observations in or near the project area (e.g.,
long-finned pilot whale: CETAP 1982; Atlantic spotted dolphin: Barkasky and Kelly (2018); common dolphin,
bottlenose dolphin: AMAPPS 2021).
Animal movement and exposure modeling was not used to determine
potential exposures from vibratory pile driving. Rather, the modeled
acoustic ranges to isopleths corresponding to the Level A harassment
and Level B harassment thresholds were used to calculate the area
around the cofferdam predicted to be ensonified daily to levels that
exceed the thresholds, or the Zone of Influence (ZOI). ZOI is
calculated as the following:
ZOI = [pi]r\2\,
where r is the linear acoustic range from the source to the isopleth
corresponding to Level A harassment or Level B harassment thresholds.
This area was adjusted to account for the portion of the ZOI truncated
by the coastline of Long Island, NY.
The daily area was then multiplied by the maximum monthly density
of a given marine mammal species. Roberts et al. (2018) produced
density models for all seals, but did not differentiate by seal
species. Because the seasonality and habitat use by gray seals roughly
overlaps with that of harbor seals in the project area, it was assumed
that the mean annual density of seals could refer to either of the
respective species and was, therefore, divided equally between the two
Finally, the resulting value was multiplied by the number of
activity days that contain the potential duration of actual vibratory
pile driving (36 hours total) which is, for cofferdam installation and
removal, conservatively estimated as two days. Modeling of the Level A
harassment exposures resulting from an 18-hour period of vibratory pile
driving for installation and another 18-hour period for removal
resulted in less than one exposure for all species for each month
between October 1 and May 31. South Fork Wind plans to install a
cofferdam or casing pipe, if required, as one of the first activities
in the construction schedule; removal could occur at any time through
the expiration of the IHA. Modeled potential Level B harassment
exposures resulting from installation and removal of the cofferdam are
shown in Table 19.
Table 19--Modeled Level B Harassment Exposures Resulting From Vibratory Pile Driving To Install and Remove the
Cofferdam
Species                    Jan      Feb      Mar      Apr      May      Oct      Nov      Dec
Fin whale...............................        0        0        1        2        1        1        0        0
Minke whale.............................        2        3        3        0        0        0        2        2
Sei whale...............................        0        0        0        0        0        0        0        0
Humpback whale..........................        1        1        1        0        0        0        0        1
North Atlantic right whale..............        6        6        5        3        1        0        1        3
Atlantic white-sided dolphin............        0        0        0        1        1        1        1        1
Common dolphin..........................        1        0        0        1        3        3        4        3
Bottlenose dolphin......................      289      123       65      197    1,509    2,007    1,088      337
Harbor porpoise.........................        3        2        2        5        3       11        1        2
Gray seal...............................    1,305    1,305    1,305    1,305    1,305    1,305    1,305    1,305
Harbor seal.............................    1,305    1,305    1,305    1,305    1,305    1,305    1,305    1,305
Maximum 18-hour period of vibratory pile driving for installation and 18-hour period for removal will be
separated by at least 24 hours of no vibratory sound source operating at the cofferdam.
Modeled vibratory pile-driving activities for the SFEC (SFWF COP
Appendix J1 [Denes et al., 2018]) resulted in mean acoustic ranges to
the Level A harassment isopleth for low-frequency cetaceans (LFCs),
ranging from 742 m for 6 hours of piling to 1,470 m for 18 hours of
piling (Denes et al., 2018). Maximum acoustic ranges to Level A
harassment isopleths for other marine mammal hearing groups are all
under 103 m. Level A harassment exposures are not expected, due to
relatively low population densities of LFC species near the
installation area, animal movement and required accumulation periods
(Denes et al., 2019), the short duration of vibratory pile driving, and
mitigation measures (including a 1,500 m shutdown zone for LFCs; see
Mitigation section).
Vibratory pile driving during cofferdam installation and removal
for the SFEC HDD exit pit does have the potential to elicit behavioral
responses in marine mammals. However, predicting Level B harassment
exposure estimates resulting from vibratory pile driving is complicated
by the nearshore location, short duration of cofferdam installation and
removal, and static species density data that are not
indicative of animals transiting the nearshore environment. Marine
mammal densities were estimated from the 10 x 10 km habitat density
block from Roberts et al. (2016) and Roberts et al. (2018) that
contained the anticipated location of the temporary cofferdam. However,
density estimates are not provided for the area adjacent to the
shoreline, although some density blocks do intersect the shore. Due to
this structure, densities are artificially weighted to the nearest 100
km\2\ offshore and do not adequately represent the low numbers expected
for some groups like large whales. In addition, the species densities
represented in the Roberts et al. (2016) and Robert et al. (2018) are
provided as monthly estimates and are, therefore, not indicative of a
single-day distribution of animals within the potential ensonified
zone. The modeled range to the behavioral harassment isopleth extends
beyond 36 km from the source (Table 11); despite this extensive Level B
harassment zone, only bottlenose dolphin, harbor seal, and gray seal
exposure estimates are comparatively large. However, the relatively low
densities of most species nearshore, the seasonality of occurrence, and
the transitory nature of marine mammals coupled with the small period
of vibratory pile driving significantly reduces the risk of behavioral
harassment exposures. In addition, marine mammal species in this region
are not expected to remain in proximity to the cofferdam location for
an extended amount of time. Although the modeled Level B harassment
exposure estimates for harbor and gray seals were relatively large
(1,305), seals are only expected to be seasonally present in the
region, and there are no known rookeries documented near the cofferdam
location. Seals typically haul-out for some portion of their daily
activities, often in large groups (Hayes et al., 2020); however, the
in-water median group size is estimated to be 1-3 animals, depending on
the distance to shore (Herr et al., 2009), with larger groups typically
being associated with direct proximity to a haul-out site. There are a
few documented haul-out sites around Long Island, New York; the nearest
site is Montauk Point, approximately 20 km northeast of the northern
potential cofferdam location, where seals are primarily observed in
winter (CRESLI, 2019). Potential exposures of offshore bottlenose
dolphins varied substantially across the construction months, with a
minimum number of potential Level B harassment exposures in March (65)
and a maximum in October (2,007). The impact of vibratory pile driving
on this species (and both seal species) will be largely dependent on
the timing of the installation and removal of the cofferdam.
Given the possibility that vibratory pile driving (for installation
and removal of the cofferdam, or the casing pipe support piles) could
occur anytime in the construction schedule, the maximum modeled
exposure across months for each species (Table 19) was used to
conservatively predict take numbers and assess impacts resulting from
vibratory pile driving (Table 20). However, in response to a comment
from the Commission on the proposed IHA and as described in the Changes
from Proposed IHA to Final IHA, NMFS has increased take, by Level B
harassment, of humpback whales, white-sided dolphins, and common
dolphins. Please see Table 20 for all proposed and authorized take, by
Level B harassment, incidental to vibratory pile driving.
Table 20--Proposed and Authorized Level B Harassment Take Resulting From Vibratory Pile Driving
Population    Proposed Level      Level B
Species/stock                            estimate \1\    B harassment     harassment
take            take
Fin whale.......................................................           6,802               2               2
Minke whale.....................................................          21,968               3               3
Sei whale.......................................................           6,292               0               0
Humpback whale..................................................           1,396               1              10
North Atlantic right whale......................................             368               6               6
Atlantic white-sided dolphin....................................          93,233               1              50
Common dolphin..................................................         172,974               4             210
Bottlenose dolphin..............................................          62,851           2,007           2,007
Harbor porpoise.................................................          95,543              11              11
Gray seal.......................................................          27,300           1,305           1,305
Harbor seal.....................................................          61,336           1,305           1,305
\1\ The best available abundance estimates are derived from the NMFS' 2021 Draft SARs (Hayes et al., 2021).
NMFS' stock abundance estimate for gray seals in Table 3 applies to U.S. population only; actual stock
abundance is approximately 451,431.
Potential exposures of marine mammals to acoustic impacts from
construction survey activities were estimated using an approach similar
to that described for installation and removal of a cofferdam. For
construction surveys, however, the ZOI was calculated as follows:
ZOI = 2rd + [pi]r\2\
where r is the linear acoustic range from the source to the largest
estimated ranges to Level A harassment (36.5 m) and Level B
harassment (141 m) isopleths, and d is the survey trackline distance
per day (70 km).
The daily area was then multiplied by the mean annual density of a
given marine mammal species. Finally, the resulting value was
multiplied by the number of survey days (60).
Modeled ranges to isopleths corresponding to the Level A harassment
threshold are very small (<1 m) for three of the four marine mammal
functional hearing groups that may be impacted by the planned
activities (i.e., low-frequency and mid-frequency cetaceans, and phocid
pinnipeds; see Table 12). Based on the extremely small Level A
harassment zones for these functional hearing groups, the potential for
species within these functional hearing groups to be taken by Level A
harassment is considered so low as to be discountable. These three
functional hearing groups encompass all but one of the marine mammal
species listed in Table 3 that may be impacted by the planned
activities. There is one species (harbor porpoise) within the high-
frequency functional hearing group that may be impacted by the planned
activities. However, the largest modeled range to the Level A
isopleth for the high-frequency functional hearing group was only 36.5
m (Table 12). More importantly, Level A harassment would also be more
likely to occur at close approach to the sound source, or as a result
of longer duration exposure to the sound source. Mitigation measures
(including a 100-m shutdown zone for harbor porpoises) are expected to
minimize the potential for exposure to HRG sources that would result in
Level A harassment. In addition, harbor porpoises are a notoriously shy
species, known to avoid vessels, and would be expected to avoid a sound
source prior to that source reaching a sound level that would result in
injury (Level A harassment). Therefore, NMFS has determined that the
potential for take by Level A harassment of harbor porpoises is so low
as to be discountable. The modeled Level B harassment exposures of
marine mammals resulting from construction survey activities are shown
in Table 21.
Table 21--Modeled Level B Harassment Exposures Resulting From
Construction Surveys of the SFWF and SFEC
Population        Level B
Species                   estimate \1\     harassment
Fin whale...............................           6,802               3
Minke whale.............................          21,968               1
Sei whale...............................           6,292              <1
Humpback whale..........................           1,396               1
North Atlantic right whale..............             368               3
Sperm whale.............................           4,349              <1
Atlantic spotted dolphin................          39,215              <1
Atlantic white-sided dolphin............          93,233              26
Common dolphin..........................         172,974              47
Bottlenose dolphin......................          62,851              28
Risso's dolphin.........................          35,215              <1
Long-finned pilot whale.................          39,215               4
Harbor porpoise.........................          95,543              43
Gray Seal...............................          27,300              14
Harbor seal.............................          61,336              14
\1\ The best available abundance estimates are derived from the NMFS'
2021 Draft SARs (Hayes et al., 2021). NMFS' stock abundance estimate
for gray seals in Table 3 applies to U.S. population only; actual
stock abundance is approximately 451,431.
The proposed and authorized number of takes by Level B harassment
resulting from construction surveys are shown in Table 22. Again, as
NMFS has determined that the likelihood of take of any marine mammals
in the form of Level A harassment occurring as a result of the planned
surveys is so low as to be discountable, and South Fork Wind did not
request any take by Level A harassment associated with construction
surveys, NMFS does not authorize take by Level A harassment of any
marine mammals.
The seasonal mean number of minke whales sighted during marine site
characterization surveys in or near the Lease Area in 2017 and 2018 was
19; therefore, South Fork Wind increased the number of takes requested
for minke whales from 1 to 19. Preliminary PSO reports from similar
surveys in or near the Lease Area in 2019 and 2020 show a high number
of common dolphin detections within the estimated Level B harassment
zones. Using a mean group size of 25 (based on sightings during
monitoring efforts in the project area), South Fork Wind multiplied the
mean group size by the number of Level B harassment exposures modeled
(47) to produce the number of takes, by Level B harassment, they
requested (1,175). There were zero exposures estimated for several
species; however, as a precautionary measure, South Fork Wind
requested, and NMFS has authorized, Level B harassment takes for those
species based on published values of mean group sizes (Atlantic spotted
dolphin, Risso's dolphin, Barkaszi and Kelly (2018)). After review of
the scientific literature, NMFS has increased authorized take, by Level
B harassment, of long-finned pilot whales from 4 to 20, based on the
largest reported group size (CETAP 1982). Please see Table 22 for all
proposed and authorized take, by Level B harassment, incidental to
construction surveys.
Table 22--Proposed and Authorized Level B Harassment Take Resulting From Construction Surveys of the SFWF and
SFEC
take \2\          take
Minke whale.....................................................          21,968          19 (1)              19
Sei whale.......................................................           6,292           1 (0)               1
Humpback whale..................................................           1,396               1               1
Sperm whale.....................................................           4,349           3 (0)               3
Long-finned pilot whale.........................................          39,215               4              20
Atlantic spotted dolphin........................................          39,921          13 (0)              13
Atlantic white-sided dolphin....................................          93,233              26              26
Common dolphin..................................................         172,974      1,175 (47)           1,175
Risso's dolphin.................................................          35,493          30 (0)              30
Bottlenose dolphin..............................................          62,851              28              28
Gray seal.......................................................          27,300              14              14
Harbor seal.....................................................          61,336              14              14
\2\ The modeled number of takes is shown in parentheses.
Combined Activity Authorized Take
The number of takes, by Level A harassment and Level B harassment,
authorized incidental to the combined activities (impact pile driving
of monopiles using a noise mitigation system, vibratory pile driving,
and construction surveys) are provided in Table 23. NMFS also presents
the percentage of each stock taken based on the total amount of take.
The mitigation and monitoring measures provided in the Mitigation and
Monitoring and Reporting sections are activity-specific and are
designed to minimize acoustic exposures to marine mammal species.
The take numbers NMFS has authorized (Table 23) are considered
conservative for the following key reasons:
Authorized take numbers for impact pile driving of
monopiles assume a maximum piling schedule (16 monopiles installed in
20 days);
Authorized take numbers for vibratory pile driving assume
that a sheet pile temporary cofferdam will be installed (versus the
alternative installation of a casing pipe for which less take is
expected);
monopiles are conservatively based on maximum densities across the
planned construction months;
Authorized Level A harassment take numbers do not fully
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;
Authorized take numbers do not fully account for the
effectiveness of mitigation and monitoring measures in reducing the
number of takes to effect the least practicable adverse impact (with
the exception of the seasonal restriction on impact pile driving of
monopiles, which is accounted for in the authorized take numbers).
Table 23--Authorized Take by Level A Harassment and Level B Harassment for All Activities \1\ Conducted During
SFWF and SFEC Construction
Authorized take for all
construction activities          Total
Population \2\ --------------------------------   authorized     Percentage of
Species/stock              estimate         Level A         Level B      take (Level A   population or
harassment      harassment      + Level B)     stock (%) \3\
Fin whale.......................           6,802               1              11              12            0.28
Minke whale.....................          21,968               1              32              33            0.15
Sei whale.......................           6,292               1               2               3            0.06
Humpback whale..................           1,396               4              19              23            1.65
North Atlantic right whale......             368               0              13              13            3.53
Sperm whale.....................           4,349               0               6               6            0.14
Pilot whales (long-finned)......          39,215               0              40              40            0.10
Atlantic spotted dolphin........          39,921               0              26              26            0.07
Atlantic white-sided dolphin....          93,233               0             183             183            0.20
Common dolphin..................         172,974               0           1,945           1,945            1.12
Risso's dolphin.................          35,215               0              60              60            0.17
Bottlenose dolphin..............          62,851               0           2,381           2,318            3.79
Harbor porpoise.................          95,543               0             132             132            0.14
Gray seal.......................         451,431               0           1,379           1,379            0.31
Harbor seal.....................          61,336               0           1,373           1,373            1.81
\1\ Activities include impact pile driving of monopiles using a noise mitigation system, vibratory pile driving,
and construction surveys.
\3\ Calculations of percentage of stock taken are based on the best available abundance estimate.
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, NMFS
carefully considers 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
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 (e.g., ramp-up, establishing harassment zone, implementing
shutdown zones, etc.). Additional measures have also been incorporated
to account for the fact that some of the planned activities would occur
offshore. Modeling was performed to estimate ensonified areas or ZOIs;
these ensonified area values were used to inform mitigation measures
for all analyzed construction 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.
Several measures have been added or modified since the proposed IHA was
published, and are identified and described in detail below.
In addition to the specific measures described later in this
section, South Fork Wind must conduct briefings for construction
supervisors and crews, the marine mammal and acoustic monitoring teams,
and South Fork Wind staff prior to the start of all pile-driving and
construction survey activity, and when new personnel join the work, in
order to explain responsibilities, communication procedures, the marine
mammal monitoring protocols, and operational procedures. South Fork
Wind must use available sources of information on NARW presence,
including daily monitoring of the Right Whale Sightings Advisory
System, monitoring of Coast Guard VHF Channel 16 throughout the day to
receive notifications of any sightings, and information associated with
any DMAs. This measure was not included in the proposed IHA, but
affords increased protection of NARWs by raising awareness of NARW
presence in the area through ongoing visual and passive acoustic
monitoring efforts (outside of South Fork Wind's efforts), and allows
for planning of construction activities, when practicable, to minimize
potential impacts on NARWs.
Seasonal Restriction on Impact Pile Driving of Monopiles
Based on the best available information (Kraus et al., 2016;
Roberts et al., 2017, 2020), the highest densities of NARWs in the
project area are expected from January through April. As described in
the proposed IHA, impact pile driving of monopiles must not occur
January 1 through April 30. In addition, impact pile driving of
monopiles must not occur in December unless unanticipated delays due to
weather or technical problems, notified to and approved by BOEM, arise
that necessitate extending impact pile driving of monopiles into
December. NMFS is requiring this seasonal restriction to minimize the
potential for NARWs to be exposed to noise incidental to impact pile
driving of monopiles. However, South Fork Wind's revised project
schedule includes installation of a cofferdam or casing pipe (in
preparation for HDD) as the first construction activity during the
period of effectiveness of the IHA (starting November 15, 2022).
Therefore, based on South Fork Wind's construction schedule, impact
pile driving of monopiles will not occur from November 15, 2022 through
April 30, 2023. Impact pile driving of monopiles will occur between May
1, 2023 and November 14, 2023. No more than one monopile will be driven
per day. Monopiles must be no larger than 11 m in diameter. For all
monopiles, the minimum amount of hammer energy necessary to effectively
and safely install and maintain the integrity of the monopiles must be
used. Hammer energies must not exceed 4,000 kJ.
Clearance and Shutdown Zones
South Fork Wind must use PSOs and PAM PSOs to establish clearance
zones around the impact pile-driving location to ensure these zones are
clear of marine mammals prior to the start of impact pile driving. The
purpose of ``clearance'' of a particular zone is to prevent potential
instances of auditory injury, and more severe behavioral disturbance as
a result of exposure to impact pile-driving noise, by delaying the
activity before it begins if marine mammals are detected within certain
pre-defined distances of the impact pile-driving vessel. The primary
goal in this case is to prevent auditory injury (PTS) of NARWs and
reduce the risk of PTS for other marine mammals where there is
potential for it to occur. The clearance zones are larger than the
modeled ranges to isopleths (based on ER95percent
SELcum), assuming 10-dB attenuation, corresponding to Level
A harassment thresholds for all marine mammal species except humpback
whales. These zone sizes vary by species and are shown in Tables 24 and
25. All distances to the perimeter of clearance zones are the radii
from the center of the pile. The clearance zones for large whales
(excluding humpback whales), harbor porpoises, and seals are based on
the maximum range to the Level A harassment isopleth plus a 20-percent
buffer, rounded up for PSO clarity. For mid-frequency cetaceans,
modeled ranges to the Level A harassment isopleth are 0 m, based on
ER95percent SELcum (assuming 10-dB attenuation).
Although the Level A harassment zones based on SPLpeak are
small for mid-frequency cetaceans, clearance zones are defined using a
precautionary distance of 100-m, and will extend to that distance or
just beyond the placement of the noise mitigation system, whichever is
further.
The Level A harassment zone (based on ER95percent
SELcum) is larger for humpback whales than other low-
frequency baleen whales because the animal movement modeling used to
estimate the associated range to the Level A harassment isopleth relies
on behavior-based exposures with no aversion (based on the best
available data that inform the animat models). Specific movement
parameters help drive the larger zone size for humpback whales,
including a modeled preference for slightly deeper water than the
depths in the SFWF. This modeled preference resulted in fewer
exposures, but each exposure was farther from the impact piling
location, producing the larger Level A harassment zone. While the
clearance zone (2,200 m) for humpback whales is smaller than the Level
A harassment zone (3,642 m), visual monitoring must be conducted from
both the impact pile driving vessel and a secondary, smaller vessel (on
which dedicated PSOs must be deployed) surveying the circumference of
the pile-driving vessel at a radius approximate to the clearance zone
for non-NARW large whales (2,200 m). NMFS expects that, depending on
visibility conditions, this additional visual monitoring will
facilitate detection of humpback whales within the Level A harassment
zone (3,642 m) for the species, beyond the farthest extent of the
clearance zone.
The NARW clearance zone is conservatively based on the Level B
harassment zone (4,684 m), rounded up to 5,000 m for PSO clarity. PSOs
and PAM PSOs may use a combination of visual observation and real-time
PAM to clear this zone (see Monitoring and Reporting); however, as
noted in the Changes from Proposed IHA to Final IHA, the 2.2-km minimum
visibility zone is defined as the area over which PSOs must be able to
clearly observe marine mammals, including NARWs, to begin the clearance
process. When visibility conditions permit (i.e., on clear days), PSOs
will be able to detect marine mammals at farther distances. Under all
circumstances, a visual detection of a NARW at any distance by a PSO on
the impact pile-driving or dedicated PSO vessel will trigger a delay.
Further, any large whale sighted by a PSO within 2,000 m of the pile
NARW, triggering a delay in impact pile driving of monopiles. In
addition, an acoustic detection of a NARW localized to a position
within the 5-km radius clearance zone will trigger a delay. Finally,
the PAM system will likely be capable of detecting NARW over an
approximately 10-km radius from the pile, providing PAM PSOs with the
capacity to monitor an area larger than the NARW clearance zone.
Detections of potential NARW vocalizations originating from outside the
PAM clearance zone will provide situational awareness to PSOs.
Table 24--Impact Pile Driving of Monopiles: Radial Distances (m) to Level A Harassment and Level B Harassment Isopleths, Required Clearance and Shutdown
Zones, and Vessel Separation Distances
Level A         Level A         Level B                                       separation
Species                            harassment      harassment      harassment    Clearance zone   Shutdown zone   distance from
zone  (SEL)      zone (PK)         zone                                       marine mammals
Fin whale \E\...........................................           1,756            <=10           4,684           2,200           2,000             100
Minke whale.............................................           1,571            <=10           4,684           2,200           2,000             100
Sei whale \E\...........................................           1,769            <=10           4,684           2,200           2,000             100
Humpback whale..........................................           3,642            <=10           4,684           2,200           2,000             100
North Atlantic right whale \E\..........................           1,621             <10           4,684    See Table 25    See Table 26             500
Sperm whale \E\.........................................  ..............            <=10           4,684           2,200           2,000             100
Atlantic spotted dolphin................................  ..............            <=10           4,684             100              50              50
Atlantic white-sided dolphin............................  ..............            <=10           4,684             100              50              50
Common dolphin..........................................  ..............            <=10           4,684             100              50              50
Risso's dolphin.........................................  ..............            <=10           4,684             100              50              50
Bottlenose dolphin......................................  ..............            <=10           4,684             100              50              50
Long-finned pilot whale.................................  ..............            <=10           4,684             100              50              50
Harbor porpoise.........................................             365             243           4,684             450             450              50
Phocid Pinnipeds in Water
Gray seal...............................................             117              12           4,684             150             150              50
Harbor seal.............................................              85              12           4,684             150             150              50
\1\ Upon receipt of an interim SFV report, NMFS may adjust the zones to reflect SFV measurements. However, minimum visibility zone will not be
decreased, and zones for fin, sei, and sperm whales must not be decreased to a size less than 1 km. Zone sizes for NARWs must not be reduced.
\2\ dB = decibel; SEL = cumulative sound exposure level; PK = peak sound pressure level.
\2\ SEL values are the 95% Exposure Ranges (ER95%) and assume 10-dB attenuation.
\E\ ESA-listed.
Table 25--Required NARW Clearance and Real-Time PAM Monitoring Zones
(Radial Distances From the Pile) for Monopile Installation
Minimum visibility zone \1\ \2\     PAM clearance      PAM monitoring
\3\                      zone \4\           zone \5\
2.2 km............................               5 km              10 km
\1\ Defined as the area over which PSOs must be able to clearly observe
marine mammals, including NARWs, to begin clearance process. This zone
size cannot be reduced.
\2\ A visual detection of a NARW at any distance from the pile by a PSO
on the pile-driving vessel or dedicated PSO vessel triggers a delay in
pile driving.
\3\ Any large whale sighted by a PSO within 2,000 m of the pile that
cannot be identified to species must be treated as if it were a NARW.
\4\ A confirmed PAM detection of a NARW within the PAM clearance zone
must be treated as a visual detection, triggering a delay in pile
driving.
\5\ Calls detected outside of the PAM clearance zone must be reported to
the lead PSO immediately for situational awareness, but will not
trigger a delay in pile driving.
\6\ Zone sizes for NARWs must not be decreased.
Table 26--Required NARW Shutdown Zones for Monopile Installation
NARW shutdown zone \1\ \2\  (Visual and PAM)
Visual                                 PAM
Any distance............................................            2 km
\1\ If NARW is sighted at any distance, a shutdown of pile driving must
be implemented when practicable, as described under Condition
4(a)(ix)(1-3) of this IHA.
\2\ A confirmed PAM detection of a NARW within the PAM shutdown zone
must be treated as a visual detection, triggering a shutdown of pile
Prior to the start of impact pile driving of monopiles, both visual
and PAM (for NARWs) clearance zones will be monitored for 60 minutes to
ensure that they are clear of the relevant species of marine mammals.
The entire minimum visibility zone must be visible (i.e., not obscured
by dark, rain, fog, etc.) for a full 30 minutes immediately prior to
commencing impact pile driving. Impact pile driving may only commence
once PSOs and PAM PSOs have declared the respective clearance zones
clear of marine mammals. If a marine mammal is observed approaching or
entering the relevant clearance zones prior to the start of impact pile
driving, pile-driving activity must be delayed until either the marine
mammal has voluntarily left the respective clearance zone and been
visually confirmed beyond that clearance zone, 30 minutes have elapsed
without re-detection of the animal in the case of mysticetes (including
NARWs), sperm whales, Risso's dolphins and pilot whales, or 15 minutes
have elapsed without re-detection of the animal in the case of all
other marine mammals. For NARWs, there is an additional requirement
that the clearance zone may only be declared clear if no confirmed NARW
acoustic detections (in addition to visual) have occurred during the
30-minute monitoring period.
The shutdown zones for non-NARW large whales, harbor porpoises, and
seals are based on the maximum Level A harassment zone for each group
(excluding humpback whales), increased by a 10-percent buffer and
rounded up for PSO clarity (Table 24). Similar to clearance zones, mid-
frequency cetacean (except sperm whale) shutdown zones will extend to
the larger of two distances: 50 m, or just outside the noise mitigation
system. For NARWs, a visual detection at any distance by a PSO (from
the impact pile-driving vessel or dedicated PSO vessel) or acoustic
detection localized to a position within 2,000 m of the pile will
trigger shutdown of impact pile driving (Table 26).
If a species for which authorization has not been granted, or, a
number of takes has been met, approaches or is observed within the
Level B harassment zone, impact pile-driving activities must be shut
down immediately or delayed if impact pile driving has not commenced.
Impact pile driving must not commence or resume until the animal has
been confirmed to have left the Level B harassment zone on its own
volition, or a full 30 minutes have elapsed with no further sightings.
Soft Start of Impact Pile Driving
The use of a soft start procedure is believed to provide additional
protection to marine mammals by warning them, or providing them with a
chance to leave the area prior to the hammer operating at full
capacity. Soft start typically involves initiating hammer operation at
a reduced energy level (relative to full operating capacity) followed
by a waiting period. South Fork Wind must utilize a soft start protocol
for impact pile driving of monopiles by performing 4-6 strikes per
minute at 10 to 20 percent of the maximum hammer energy, for a minimum
of 20 minutes. NMFS notes that it is difficult to specify a reduction
in energy for any given hammer because of variation across drivers. For
impact hammers, the actual number of strikes at reduced energy will
vary because operating the hammer at less than full power results in
``bouncing'' of the hammer as it strikes the pile, resulting in
multiple ``strikes''; however, as mentioned previously, South Fork Wind
will target less than 20 percent of the total hammer energy for the
initial hammer strikes during soft start. Soft start will be required
at the beginning of each day's monopile installation, and at any time
following a cessation of impact pile driving of 30 minutes or longer.
Shutdown of Impact Pile-Driving
The purpose of a shutdown is to prevent some undesirable outcome,
such as auditory injury or severe behavioral disturbance of sensitive
species, by halting the activity. If a marine mammal is observed
entering or within the respective shutdown zone (Table 24) after impact
pile driving has
begun, the PSO will request a temporary cessation of impact pile
In situations when shutdown is called for but South Fork Wind
determines shutdown is not practicable due to imminent risk of injury
or loss of life to an individual, or risk of damage to a vessel that
creates risk of injury or loss of life for individuals, reduced hammer
energy must be implemented when the lead engineer determines it is
practicable. After shutdown, impact pile driving may be reinitiated
once all clearance zones are clear of marine mammals for the minimum
species-specific periods, or, if required to maintain installation
feasibility. Installation feasibility refers to ensuring that the pile
installation results in a usable foundation for the WTG (e.g.,
installed to the target penetration depth without refusal).
Visibility Requirements
Impact pile driving of monopiles must not be initiated at night, or
when the full extent of the clearance zones (Table 24) cannot be
confirmed to be clear of marine mammals, as determined by the lead PSO
on duty. As mentioned previously, the 2.2 km clearance zone for non-
NARW baleen whales may only be declared clear when the full extent of
the minimum visibility zone is visible (i.e., when not obscured by
dark, rain, fog, etc.) and PSOs have not detected marine mammals for a
full 30 minutes prior to impact pile driving. Impact pile driving of
monopiles may continue after dark only when driving of the same pile
began no less than 90 minutes prior to civil sunset, when the minimum
visibility zone for impact pile driving of monopiles was fully visible,
and must proceed for human safety or installation feasibility reasons.
PSOs must utilize alternative technology (Infrared (IR) and/or Thermal
camera) to monitor clearance zones if impact pile driving of monopiles
continues past civil sunset.
Sound Attenuation
South Fork Wind must implement noise mitigation technology designed
to result in the targeted reduction in sound levels that would produce
corresponding to those modeled assuming 10-dB sound attenuation,
pending results of SFV (see Acoustic Monitoring for Sound Field and
Harassment Isopleth Verification section below). The noise mitigation
system must be either (1) a single BBC coupled with an additional noise
mitigation device, or (2) a dBBC.
The bubble curtain(s) must distribute air bubbles using a target
air flow rate of at least 0.5 m\3\/(min*m), and must distribute bubbles
around 100 percent of the piling perimeter for the full depth of the
water column. The lowest bubble ring must be in contact with the
seafloor for the full circumference of the ring, and the weights
attached to the bottom ring must ensure 100-percent seafloor contact.
No parts of the ring or other objects should prevent full seafloor
contact. South Fork Wind must require that construction contractors
train personnel in the proper balancing of airflow to the bubble ring,
and must require that construction contractors submit an inspection/
performance report for approval by South Fork Wind within 72 hours
following the performance test. Corrections to the attenuation device
to meet the performance standards must occur prior to impact driving.
If South Fork Wind uses a noise mitigation device in addition to a BBC,
similar quality control measures must be required.
Vibratory pile driving or impact driving of a casing pipe must
occur at the export cable landing site only.
Vibratory pile driving of sheet piles may continue after dark only
when the driving of the same pile began no less than 90 minutes prior
to civil sunset, when the clearance zones were fully visible for a full
30 minutes immediately prior to commencing pile driving, and
installation of sheet piles must proceed for human safety or
installation feasibility reasons.
South Fork Wind must implement visual monitoring of the clearance
zones for 30 minutes immediately prior to the initiation of ramp-up of
vibratory piling equipment (Table 27). During this period, the
clearance zone will be monitored by the PSOs, using the appropriate
visual technology. Ramp-up may not be initiated if any marine mammal(s)
is detected within its respective clearance zone. If a marine mammal is
observed within a clearance zone during the clearance period, ramp-up
may not begin until the animal(s) has been observed exiting its
respective clearance zone or until an additional time period has
elapsed with no further sighting (i.e., 15 minutes for small
odontocetes and seals, and 30 minutes for all other species).
Table 27--Installation and Removal Of a Temporary Cofferdam: Radial Distances (m) to Level A Harassment and
Level B Harassment Isopleths, Required Clearance and Shutdown Zones, and Vessel Separation Distances.
Level A         Level B                                       separation
Species                harassment      harassment    Clearance zone   Shutdown zone   distance from
zone  (SEL)     zone (SPL)                                    marine mammals
Fin whale.......................           1,470          36,766           1,500           1,500             100
Minke whale.....................           1,470          36,766           1,500           1,500             100
Sei whale.......................           1,470          36,766           1,500           1,500             100
Humpback whale..................           1,470          36,766           1,500           1,500             100
North Atlantic right whale......           1,470          36,766           1,500           1,500             500
Sperm whale.....................  ..............          36,766           1,500           1,500             100
Atlantic spotted dolphin........  ..............          36,766             100              50              50
Atlantic white-sided dolphin....  ..............          36,766             100              50              50
Common dolphin..................  ..............          36,766             100              50              50
Risso's dolphin.................  ..............          36,766             100              50              50
Bottlenose dolphin..............  ..............          36,766             100              50              50
Long-finned pilot whale.........  ..............          36,766             100              50              50
Harbor porpoise.................              63          36,766             100             100              50
Gray seal.......................             103          36,766             150             125              50
Harbor seal.....................             103          36,766             150             125              50
SEL = cumulative sound exposure level in units of decibels referenced to 1 micropascal squared second.
SPL = root-mean-square sound pressure level in units of decibels referenced to 1 micropascal.
Shutdown of Vibratory Pile Driving
An immediate shutdown of vibratory pile-driving equipment must be
implemented if a marine mammal(s) is sighted entering or within its
respective shutdown zone after cofferdam installation has commenced.
Resumption of vibratory pile driving may begin if the animal(s) has
been observed exiting its respective shutdown zone or an additional
time period has elapsed without a resighting (i.e., 15 minutes for
small odontocetes and seals and 30 minutes for all other species). If a
species for which authorization has not been granted, or a species for
which authorization has been granted but the authorized number of takes
has been met, approaches or is observed within the Level B harassment
zone, vibratory pile-driving activities must be shut down immediately
or delayed if vibratory pile driving has not commenced. Vibratory pile
driving must not must not recommence until the animal(s) has been
confirmed to have left the Level B harassment zone or a full 15 min
(small odontocetes and seals) or 30 min (all other marine mammals) have
elapsed with no further sightings.
South Fork Wind must implement a 30-minute clearance period of the
clearance zones (Table 28) immediately prior to the initiation of ramp-
up of boomers, sparkers, and Chirps. Since publication of the proposed
IHA, the clearance zones for ESA-listed species have been increased
from 100 to 500 m to align with standard marine site characterization
mitigation and monitoring measures. Any large whale sighted by a PSO
within 1,000 m of boomers, sparkers, and Chirps that cannot be
identified to species must be treated as if it were a NARW. The
clearance zones will be monitored by PSOs, using the appropriate visual
technology. If a marine mammal is observed within a clearance zone
during the clearance period, ramp-up (described below) may not begin
until the animal(s) has been observed voluntarily exiting its
odontocetes and seals, and 30 minutes for all other species). In cases
when the clearance process has begun in conditions with good
visibility, including via the use of night vision equipment (IR/thermal
camera), and the lead PSO has determined that the clearance zones are
clear of marine mammals, survey operations may commence (i.e., no delay
is required) despite periods of inclement weather and/or loss of
daylight. In cases when the shutdown zones become obscured for brief
periods due to inclement weather, survey operations may continue (i.e.,
no shutdown is required).
Table 28--Construction Surveys Operating Chirp Sub-Bottom Profilers, Boomers, and Sparkers: Radial Distances (m) to Level A Harassment and Level B
Harassment Isopleths, Required Clearance and Shutdown Zones, and Vessel Separation Distances.
Maximum extent of zones
----------------------------------------------------------------     Vessel
Level A         Level A        Level B harassment zones                                       separation
Species                    harassment      harassment   --------------------------------                                  distance from
zone (SEL)       zone (PK)                      Boomers and   Clearance zone   Shutdown zone  marine mammals
Chirps         sparkers
Fin whale...............................              <1              <1              54             141             500             100             100
Minke whale.............................              <1              <1              54             141             100             100             100
Sei whale...............................              <1              <1              54             141             500             100             100
Humpback whale..........................              <1              <1              54             141             100             100             100
North Atlantic right whale..............              <1              <1              54             141             500             500             500
Sperm whale.............................              <1              <1              54             141             500             100             100
Atlantic spotted dolphin................              <1              <1              54             141             100  ..............              50
Atlantic white-sided dolphin............              <1              <1              54             141             100  ..............              50
Common dolphin..........................              <1              <1              54             141             100  ..............              50
Risso's dolphin.........................              <1              <1              54             141             100  ..............              50
Bottlenose dolphin......................              <1              <1              54             141             100  ..............              50
Long-finned pilot whale.................              <1              <1              54             141             100  ..............              50
Harbor porpoise.........................              37               5              54             141             100             100              50
Gray seal...............................              <1              <1              54             141             100  ..............              50
Harbor seal.............................              <1              <1              54             141             100  ..............              50
Ramp-Up of HRG Survey Equipment
At the start or restart of the use of boomers, sparkers, and/or
Chirps, a ramp-up procedure must be implemented. Ramp-up must begin
with the powering up of the specified HRG equipment at the lowest power
output appropriate for the survey. When practicable, the power must
then be gradually turned up, and then any other acoustic sources added.
The ramp-up procedure must be used at the beginning of construction
survey activities using the specified HRG equipment to provide
additional protection to marine mammals in or near the survey area by
allowing them to vacate the area prior to operation of survey equipment
at full power.
Ramp-up activities will be delayed if a marine mammal(s) enters its
respective clearance zone. Ramp-up will continue if the animal(s) has
been observed exiting its respective clearance zone or until additional
time has elapsed with no further sighting (i.e, 15 minutes for small
Shutdown of Construction Survey Equipment
An immediate shutdown of boomers and sparkers is required if a
marine mammal(s) is sighted entering or within its respective shutdown
zone. No shutdown is required for Chirp sub-bottom profilers. The
vessel operator must comply immediately with any call for shutdown by
the Lead PSO. Any disagreement between the Lead PSO and vessel operator
should be discussed only after shutdown has occurred. Subsequent
restart of the survey equipment may be initiated if the animal(s) has
been observed exiting its respective shutdown zone or until an
additional period has elapsed (i.e., 15 minutes for small odontocetes
and seals and 30 minutes for all other marine mammals).
If a species for which authorization has not been granted, or a
Level B harassment zone, boomers and sparkers must be shut down
immediately, or use delayed if not yet activated. Use of boomers and
sparkers must not must not commence or resume until the animal(s) has
been confirmed to have left the Level B harassment zone or a full 15
minutes (small odontocetes and seals) or 30 minutes (for all other
marine mammals) have elapsed with no further sightings.
If a boomer, sparker, or Chirp is shut down for reasons other than
mitigation (e.g., mechanical difficulty) for less than 30 minutes, it
may be activated again without ramp-up if PSOs have maintained constant
observation and no detections of any marine mammal have occurred within
the respective shutdown zones. If a boomer, sparker, or Chirp is shut
down for a period longer than 30 minutes, then clearance and ramp-up
procedures must be initiated as described in the previous section.
The shutdown requirement will be waived for small delphinids of the
following genera: Delphinus, Stenella, and Tursiops. Specifically, if a
delphinid from the specified genera is visually detected approaching
the vessel (i.e., to bow ride) or towed equipment, shutdown is not
required. Furthermore, if there is uncertainty regarding identification
of a marine mammal species (i.e., whether the observed marine mammal(s)
belongs to one of the delphinid genera for which shutdown is waived),
PSOs must use their best professional judgement in making the decision
to call for a shutdown. Additionally, shutdown is required if a
delphinid that belongs to a genus other than those specified is
detected in the shutdown zone.
Vessel Strike Avoidance
The IHA contains numerous vessel strike avoidance measures. South
Fork Wind is required to comply with these measures except under
circumstances when doing so would create an imminent and serious threat
to a person or vessel, or to the extent that a vessel is restricted in
its ability to maneuver and, because of the restriction, cannot comply.
South Fork Wind must submit a NARW vessel strike avoidance plan 90
days prior to commencement of vessel use. The plan will describe, at a
minimum, how PAM will be conducted
to ensure the transit corridor is clear of NARWs. The plan must also
provide details on the vessel-based observer protocols on transiting
vessels. The requirement to submit this plan was not included in the
proposed IHA.
Vessel operators and crews must maintain a vigilant watch for all
marine mammals and slow down, stop their vessel, or alter course as
appropriate and regardless of vessel size, to avoid striking any marine
mammal. A visual observer aboard the vessel must monitor a vessel
strike avoidance zone around the vessel (distances stated below).
Visual observers monitoring the vessel strike avoidance zone may be
third-party observers (i.e., PSOs) or crew members, but crew members
responsible for these duties must be provided sufficient training to
distinguish marine mammals from other phenomena and broadly to identify
a marine mammal as a NARW, other whale (defined in this context as
sperm whales or baleen whales other than NARWs), or other marine
mammal. South Fork Wind must adhere to the following measures:
Year-round, operators of all vessels associated with South
Fork Wind must use all available sources of information on NARW
presence, including daily monitoring of the Right Whale Sightings
Advisory System, WhaleAlert app, and Coast Guard VHF Channel 16
throughout the day to receive notifications of any sightings and/or
information associated with any Slow Zones (i.e., DMAs or acoustically-
triggered slow zones) to plan vessel routes, if practicable, to
minimize the potential for co-occurrence with any NARWs.
For construction surveys, members of the PSO monitoring
team must consult the Right Whale Sightings Advisory System, WhaleAlert
app, and monitor Coast Guard VHF Channel 16 for reports of NARW
presence in the survey area.
On all vessels associated with South Fork Wind, regardless
of size or speed of travel, operators and crews must maintain a
vigilant watch for all marine mammals and slow down, stop their vessel,
or alter course as appropriate to avoid striking any marine mammal.
Whenever multiple project-associated vessels (e.g.,
construction survey, crew transfer) are operating concurrently, any
visual observations of ESA-listed marine mammals must be communicated
to PSOs and/or vessel captains associated with other vessels to
increase situational awareness.
Vessels of all sizes associated with South Fork Wind must
operate port to port at 10 kts or less between November 1 and April 30,
and while operating in the Lease Area, along the SFEC, or transit area
to and from ports in NY, CT, RI, and MA, except for vessels transiting
inside Narragansett Bay or Long Island Sound (unless during a DMA).
Vessels transiting from other ports outside those described must
operate at 10 kts or less when within any active Seasonal Management
Area (SMA) or within the Lease Area.
For vessels of all sizes, vessel speeds must immediately
be reduced to 10 kts when any large whale, mother/calf pairs, or large
assemblages of non-delphinoid cetaceans are observed near (within 100
m) an underway vessel. In the proposed IHA, this measure only applied
to vessels greater than or equal to 65 ft (19.8 m).
The measures above were not included in the proposed IHA, but are
included in the final IHA. The measures below were included in the
proposed IHA and are carried over to the final IHA.
All vessels 65-ft (19.8 m) or greater in length must
comply with the 10-kt speed restriction rule in any SMA, per the NOAA
ship strike reduction rule (74 FR 60173; October 10, 2008).
All underway vessels (e.g., transiting, surveying) must
have a dedicated visual observer on duty at all times to monitor for
marine mammals within a 180[deg] direction of the forward path of the
vessel (90[deg] port to 90[deg] starboard). Visual observers must be
equipped with alternative monitoring technology for periods of low
visibility (e.g., darkness, rain, fog, etc.). The dedicated visual
observer must receive prior training on protected species detection and
identification, vessel strike minimization procedures, how and when to
communicate with the vessel captain, and reporting requirements in this
IHA. Visual observers may be third-party observers (i.e., NMFS-approved
PSOs) or crew members. Observer training related to these vessel strike
avoidance measures must be conducted for all vessel operators and crew
prior to the start of in-water construction activities. Confirmation of
the observers' training and understanding of the IHA requirements must
be documented on a training course log sheet and reported to NMFS.
Vessel speed must immediately be reduced to 10 kts or less
when a NARW is sighted by an observer or anyone else on the underway
vessel.
In the event that any Slow Zone (designated as a DMA) is
established that overlaps with an area where a project-associated
vessel must operate, that vessel, regardless of size, must transit that
area at 10 kts or less.
If a vessel is traveling at greater than 10 kts between
May 1 and October 31, in addition to the required dedicated observer,
real-time PAM of transit corridors must be conducted prior to and
during transits. If a NARW is detected via visual observation or PAM
within or approaching the transit corridor, all crew transfer vessels
must travel at 10 kts or less for the following 12 hours. Each
subsequent detection will trigger a 12-hour reset. A slow-down in the
transit corridor expires when there has been no further visual or
acoustic detection in the transit corridor in the past 12 hours.
All vessels must maintain a minimum separation distance of
500 m from NARWs. If a whale is observed but cannot be confirmed as a
species other than a NARW, the vessel operator must assume that it is a
NARW and take appropriate action.
If underway, all vessels must steer a course away from any
sighted NARW at 10 kts or less such that the 500-m minimum separation
distance requirement is not violated. If a NARW, or a large whale that
cannot be confirmed to species, is sighted within 500 m of an underway
vessel, that vessel must shift the engine to neutral. Engines will not
be engaged until the whale has moved outside of the vessel's path and
beyond 500 m.
100 m from sperm whales and non-NARW baleen whales. If one of these
species is sighted within 100 m of an underway vessel, that vessel must
shift the engine to neutral. Engines will not be engaged until the
whale has moved outside of the vessel's path and beyond 100 m.
All vessels must, to the maximum extent practicable,
attempt to maintain a minimum separation distance of 50 m from all
delphinoid cetaceans and pinnipeds, with an exception made for those
that approach the vessel (e.g., bow-riding dolphins). If a delphinoid
cetacean or pinniped is sighted within 50 m of an underway vessel, that
vessel must shift the engine to neutral, with an exception made for
those that approach the vessel (e.g., bow-riding dolphins). Engines
will not be engaged until the animal(s) has moved outside of the
vessel's path and beyond 50 m.
When a marine mammal(s) is sighted while a vessel is
underway, the vessel must take action as necessary to avoid violating
the relevant separation distances (e.g., attempt to remain parallel to
the animal's course, avoid excessive speed or abrupt changes in
direction until the animal has left the
area). If a marine mammal(s) is sighted within the relevant separation
distance, the vessel must reduce speed and shift the engine to neutral,
not engaging the engine(s) until the animal(s) is clear of the area.
This does not apply to any vessel towing gear or any vessel that is
navigationally constrained.
All vessels underway must not divert or alter course in
order to approach any marine mammal. Any vessel underway must avoid
excessive speed or abrupt changes in direction.
For in-water construction heavy machinery activities other
than impact or vibratory pile driving, if a marine mammal comes within
10 m of equipment, South Fork Wind must cease operations (when
practicable) until the marine mammal has moved more than 10 m on a path
away from the activity.
With the measures described herein, NMFS has prescribed the means
of effecting the least practicable adverse impact on the affected
marine mammal species and stocks and their habitat, paying particular
attention to rookeries, mating grounds, and areas of similar
significance.
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
planned action area. Effective reporting is critical both to compliance
as well as ensuring that the most value is obtained from the required
monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density).
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas).
Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors.
How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks.
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat).
Mitigation and monitoring effectiveness.
Visual Marine Mammal Observations
South Fork Wind must collect sighting data and behavioral responses
to construction activities for marine mammals species observed in the
region of activity during the period of activity. All observers must be
trained in marine mammal identification and behaviors and are required
to have no other construction-related tasks while conducting
monitoring. PSOs will monitor all clearance and shutdown zones prior
to, during, and following impact and vibratory pile driving, and while
boomers, sparkers, and Chirps are active. PSOs will also monitor Level
B harassment zones and will document any marine mammals observed within
these zones, to the extent practicable (noting that some zones are too
large to fully observe). As mentioned, South Fork Wind must conduct
monitoring before, during, and after construction activities
(monitoring durations specified below), with observers located at the
best practicable vantage points on the pile driving and dedicated PSO
vessels. Full details regarding marine mammal monitoring must be
included in a Pile Driving and Marine Mammal Monitoring Plan that,
under the IHA, South Fork Wind is required to submit to NMFS for
approval at least 90 days in advance of commencement of construction
activities. Please note submission of this plan was not included in the
proposed IHA. The following additional measures apply to visual
(1) Monitoring must be conducted by qualified, trained PSOs who
will be placed on the pile-driving and dedicated PSO vessels
(monopile), installation or nearby construction vessel (cofferdam or
casing pipe), and construction survey vessels, in positions which
represent the best vantage point to monitor for marine mammals and
implement shutdown procedures when applicable;
(2) PSOs may not exceed 4 consecutive watch hours; must have a
minimum 2-hour break between watches; and may not exceed a combined
watch schedule of more than 12 hours in a 24-hour period;
(3) PSOs must have no other construction-related tasks while
conducting monitoring;
(4) PSOs should 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;
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.
Observer teams employed by South Fork Wind 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
All PSOs must be approved by NMFS. South Fork Wind must
submit the CVs of the initial set of PSOs necessary to commence the
project to NMFS OPR for approval at least 60 days
prior to the first day of construction activities.
South Fork Wind must conduct briefings between construction
supervisors and crews and the PSO team prior to the start of all
construction activities, and when new personnel join the work, in order
to explain responsibilities, communication procedures, marine mammal
monitoring protocols, and operational procedures. An informal guide
must be included with the Marine Mammal Monitoring Plan to aid in
identifying species if they are observed in the vicinity of the project
The following are measures specific to each activity.
South Fork Wind must implement the following procedures for impact
pile driving of monopiles:
A minimum of two PSOs on the impact pile-driving vessel
must maintain watch at all times when impact pile driving is underway.
A minimum of two PSOs on a dedicated PSO vessel located at
the outer edge of the 2,200 m (or as modified based on SFV) large whale
clearance zone must maintain watch at all times when impact pile
driving of monopiles is underway.
PSOs must be located at the best vantage point(s) on the
impact pile-driving vessel and dedicated PSO vessels in order to ensure
360[deg] visual coverage of the entire clearance and shutdown zones
around the vessels, and as much of the Level B harassment zone as
The clearance zones must be monitored for the presence of
marine mammals for 60 minutes before, throughout the installation of
the monopile, and for 30 minutes after monopile installation.
During all observation periods, PSOs must use high
magnification (25X) binoculars, standard handheld (7X) binoculars, and
the naked eye to search continuously for marine mammals. During periods
of low visibility (e.g., darkness, rain, fog, etc.), PSOs must use
alternative technology (e.g., IR/Thermal camera) to monitor clearance
and shutdown zones.
Monopile installation may only commence when the minimum
visibility zone (2.2 km) is fully visible (e.g., not obscured by
darkness, rain, fog, etc.) and clearance zones are clear of marine
mammals for at least 30 minutes, as determined by the lead PSO,
immediately prior to initiation of impact pile driving of monopiles.
If the minimum visibility zone (2.2 km) is obscured by fog
or poor lighting conditions while impact pile driving of monopiles is
underway, the activity must be halted when practicable, as described
above. Following a shutdown, monopile installation may not recommence
until the minimum visibility zone is fully visible and clear of marine
mammals for 30 minutes, as described above.
During vessel transits within or to/from the SFWF (e.g., crew
transfer, etc.), an observer must be stationed on vessels at the best
vantage points to ensure maintenance of standoff distances between
marine mammals and vessels (as described above). South Fork Wind must
implement the following measures during vessel transit when there is an
observation of a marine mammal:
PSOs or dedicated observers will record the time, date,
vessel's position, heading and speed, sea state, water depth, and
visibility, marine mammal species identification, initial distance and
bearing from the vessel to the marine mammal, closest point of
approach, and any avoidance measures taken in response to the marine
mammal sighting. 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
South Fork Wind.
Cofferdam or Casing Pipe Installation and Removal
and vibratory pile driving associated with installation of a cofferdam
or casing pipe:
A minimum of two PSOs will maintain watch at all times
when vibratory pile driving or impact hammering is underway.
impact or vibratory pile-driving platform, or platform in the immediate
vicinity of the impact or vibratory pile-driving platform, in order to
ensure visual coverage of the entire visual clearance zones and as much
of the Level B harassment zone as possible.
The clearance zones will be monitored for the presence of
the sheet piles (and casing pipe, if installed), and for 30 minutes
after all vibratory pile-driving or impact-hammering activity.
During all observation periods related to impact and
vibratory pile driving, PSOs must use high-magnification (25X),
standard handheld (7X) binoculars, and the naked eye to search
continuously for marine mammals. During periods of low visibility
(e.g., darkness, rain, fog, etc.), PSOs must use alternative technology
(e.g., IR/Thermal camera) to monitor clearance and shutdown zones.
Sheet pile or casing pipe installation may only commence
when visual clearance zones are fully visible (e.g., not obscured by
darkness, rain, fog, etc.) and clear of marine mammals, as determined
by the lead PSO, for at least 30 minutes immediately prior to
initiation of impact or vibratory pile driving.
South Fork Wind must implement the following procedures for
construction surveys:
At least one PSO must be on duty on each survey vessel
during daytime operations, conducting visual observations at all times
during daylight hours (i.e., from 30 minutes prior to sunrise through
30 minutes following sunset).
A minimum of two PSOs must be on watch during nighttime
marine mammals for 30 minutes before, throughout, and for 30 minutes
after use of boomers, sparkers, and Chirps.
During all observation periods, PSOs must use standard
handheld (7X) binoculars and the naked eye to search continuously for
marine mammals. During periods of low visibility (e.g., darkness, rain,
fog, etc.), PSOs must use alternative technology (e.g., IR/Thermal
camera) to monitor clearance and shutdown zones.
Ramp-up of boomers, sparkers, and Chirps may only commence
initiation of survey activities utilizing the specified acoustic
sources.
In cases where multiple vessels are surveying
concurrently, any observations of marine mammals must be communicated
to PSOs on all nearby survey vessels.
During daylight hours when survey equipment is not
operating, South Fork Wind must ensure that visual PSOs conduct, as
rotation schedules allow, observations for comparison of sighting rates
and behavior with and without use of the specified acoustic sources.
Off-effort PSO monitoring must be reflected in the monthly PSO
monitoring reports.
NMFS requires that observers use standardized forms. In addition to
other data, South Fork Wind must record detailed information about any
implementation of delays or shutdowns, including the distance of the
animal(s) to the pile or specified HRG equipment and a description of
specific actions that ensued and resulting behavior of the animal, if
any. NMFS requires 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);
All marine mammal sightings, regardless of distance from
the construction activity;
Species, numbers, and, if possible, sex and age class of
marine mammals;
Description of any marine mammal behavioral observations
(e.g., observed behaviors such as feeding or traveling), including an
assessment of behavioral responses thought to have resulted from the
activity;
Distance and bearing of each marine mammal observed
relative to the pile being driven or specified HRG equipment for each
sighting, and time spent within harassment zones;
Type of construction activity (e.g., vibratory or impact
pile driving, construction survey) and specific phase of activity
(e.g., ramp-up of HRG equipment, HRG acoustic source on/off, soft start
for impact pile driving, active pile driving, etc.) 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.
Marine Mammal Passive Acoustic Monitoring
South Fork Wind must utilize a PAM system to supplement visual
monitoring for all monopile installations. The PAM system must be
monitored by a minimum of one PAM PSO beginning at least 60 minutes
prior to soft start of impact pile driving of monopiles, at all times
during monopile installation, and 30 minutes post-completion of
installation. PAM PSOs must immediately communicate all detections of
marine mammals at any distance (i.e., not limited to the 5-km Level B
harassment zone) to visual PSOs, including any determination regarding
species identification, distance, and bearing and the degree of
confidence in the determination.
PAM PSOs may be on watch for a maximum of four consecutive hours
followed by a break of at least two hours between watches. PAM PSOs
must be required to demonstrate that they have completed specialized
training for operating PAM systems, including identification of
species-specific mysticete vocalizations. PSOs can act as PAM PSOs or
visual PSOs (but not simultaneously) as long as they demonstrate that
their training and experience are sufficient to perform each task.
A Passive Acoustic Monitoring Plan must be submitted to NMFS and
BOEM for review and approval at least 90 days prior to the planned
start of monopile installations. PAM must follow standardized
measurement, processing methods, reporting metrics, and metadata
standards for offshore wind (Van Parijs et al., 2021). The plan must
describe all proposed PAM equipment, procedures, and protocols. Please
see the IHA for additional PAM requirements.
Acoustic Monitoring for Sound Field and Harassment Isopleth
During the first three monopile installations, South Fork Wind must
empirically determine the ranges to the isopleths corresponding to
Level A harassment and Level B harassment thresholds. For verification
of the range to the Level B harassment isopleth, South Fork Wind must
report the measured or extrapolated ranges where the received levels
SPLrms decay to 160 dB, as well as integration time for such
SPLrms. South Fork Wind may also estimate ranges to the
Level A harassment and Level B harassment isopleths by extrapolating
from in situ measurements conducted at several distances from the pile
being driven. In addition, South Fork Wind must measure received levels
at a standard distance of 750 m from the pile, or an alternative
distance as agreed to in the SFV Plan.
If acoustic field measurements for installation of the first
monopile indicate ranges to the isopleths corresponding to Level A
harassment and Level B harassment isopleths are greater than the ranges
predicted by modeling (assuming 10-dB attenuation), South Fork Wind
must implement additional noise mitigation measures prior to installing
the second monopile. Initial additional measures may include improving
the efficacy of the implemented noise mitigation technology (e.g., BBC,
dBBC) and/or modifying the piling schedule to reduce the sound source.
Each sequential modification must be evaluated empirically by acoustic
field measurements. In the event that field measurements indicate
ranges to isopleths corresponding to Level A harassment and Level B
harassment thresholds are consistently greater than the ranges
predicted by modeling (assuming 10-dB attenuation), NMFS may expand the
relevant harassment, clearance, and shutdown zones and associated
monitoring protocols. If harassment zones are expanded beyond an
additional 1,500 m, additional PSOs must be deployed on additional
platforms, with each observer responsible for maintaining watch in no
more than 180[deg] and of an area with a radius no greater than 1,500
m. Depending on the extent of zone size expansion, reinitiation of
consultation under Section 7 of the ESA may be required.
If acoustic measurements indicate that ranges to isopleths
corresponding to the Level A harassment and Level B harassment
thresholds are less than the ranges predicted by modeling (assuming 10-
dB attenuation), South Fork Wind may request a modification of the
clearance and shutdown zones for impact pile driving of monopiles. For
a modification request to be considered by NMFS, South Fork Wind must
have conducted SFV on three or more monopile installations to verify
that zone sizes are consistently smaller than predicted by modeling
(assuming 10-dB attenuation). In addition, if a subsequent monopile
installation location is selected that was not represented by previous
three locations (i.e., substrate composition, water depth), SFV must be
conducted. Upon receipt of an interim SFV report, NMFS may adjust zones
(i.e., Level A harassment, Level B harassment, clearance, and/or
shutdown) to reflect SFV measurements. The shutdown and clearance zones
would be equivalent to the measured range to the Level A harassment
isopleths plus 10 percent (shutdown zone) and 20 percent (clearance
zone), rounded up to the nearest 100 m for PSO clarity. However, the
minimum visibility zone must not be decreased to a radius smaller than
2.2 km from the pile. The shutdown zone for sei, fin, and sperm whales
must not be reduced to a size less than 1,000 m. The visual and PAM
clearance and shutdown zones for NARWs must not be decreased,
regardless of acoustic field measurements. The Level B harassment zone
would be equal to the largest
measured range to the Level B harassment isopleth.
A draft final report must be submitted to NMFS within 90 days of
the completion of activities occurring under this IHA. The report must
include marine mammal observations pre-activity, during-activity, and
post-activity for all pile-driving and construction survey days, and
must also provide descriptions of any changes in marine mammal
behavioral patterns resulting from construction activities. The report
must detail the implemented 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, documentation of when
shutdowns were called for but not implemented and why). The report must
also include results from acoustic monitoring including, but not
limited to, dates and times of all detections, types and nature of
sounds heard, whether detections were linked with visual sightings,
water depth of the hydrophone array, bearing of the animal to the
vessel (if determinable), species or taxonomic group (if determinable),
spectrogram screenshot, a record of the PAM PSO's review of any
acoustic detections, and any other notable information. A final report
must be submitted within 30 days following resolution of comments on
the draft report.
South Fork Wind will be required to provide the initial results of
SFV (including measurements) to NMFS in interim reports after each
monopile installation for the first three piles as soon as they are
available, but no later than 48 hours after each installation. If SFV
is required for subsequent monopile installations, the same reporting
timeline and data requirements apply. In addition to in situ measured
ranges to the Level A harassment and Level B harassment isopleths, the
acoustic monitoring report must include: SPLpeak,
SPLrms that contains 90 percent of the acoustic energy,
single strike sound exposure level, integration time for
SPLrms, SELss, and 24-hour cumulative SEL
extrapolated from measurements. All these levels must be reported in
the form of median, mean, max, and minimum. The acoustic monitoring
report must also include a description of the hydrophones used,
hydrophone and water depth, distance to the pile driven, and sediment
type at the recording location. Final results of SFV must be submitted
as soon as possible, but no later than within 90 days following
completion of impact pile driving of monopiles. Please see the IHA for
a full list of reporting requirements.
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. NMFS also assesses the number, intensity, and
context of estimated takes by evaluating this information relative to
population status. Consistent with the 1989 preamble for NMFS's
implementing regulations (54 FR 40338; September 29, 1989), the impacts
from other past and ongoing anthropogenic activities are incorporated
into this analysis via their impacts on the environmental baseline
(e.g., as reflected in the regulatory status of the species, population
size and growth rate where known, ongoing sources of human-caused
mortality, or ambient noise levels).
Impact and vibratory pile-driving and construction survey
activities associated with South Fork Wind's 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 (PTS, from impact pile driving
only) or Level B harassment (potential behavioral disturbance) from
underwater sounds generated by pile driving (impact and vibratory) and
certain HRG active acoustic sources used for construction surveys.
Potential take could occur if individual marine mammals are present in
the ensonified zone when any pile-driving or construction survey
activities are occurring.
To avoid repetition, the majority of our analyses apply to all the
species listed in Table 3, given that many of the anticipated effects
of South Fork Wind's project on different marine mammal stocks are
expected to be relatively similar in nature. Where there are meaningful
differences between species or stocks--as is the case of the NARW--they
are included as separate subsections below.
Non-NARW Marine Mammal Species
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 (i.e., PTS), even in the absence of the mitigation
measures (Table 16). The potential for injury is expected to be greatly
minimized through implementation of mitigation measures including soft
start, use of a noise mitigation system, and the implementation of
clearance zones that would facilitate a delay of impact pile driving of
monopiles if marine mammals were observed (visually and/or
acoustically) 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 it
becoming potentially injurious (i.e., PTS) or resulting in more severe
behavioral reactions. The requirement that the clearance process for
impact and vibratory pile driving may only commence when the full
extents of the respective visual clearance zones are entirely visible
to PSOs will facilitate a high rate of success in marine mammal
detection and implementation of mitigation measures (i.e., delay) to
avoid injury.
NMFS expects that any take resulting from exposures above the Level
A harassment threshold would be in the form of slight PTS (minor
degradation of hearing capabilities within regions of hearing that
align most completely with the energy produced by impact 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, much less impact reproduction
or survival.
Additionally, the amount of authorized take, by Level A harassment,
is very low for all marine mammal stocks and species. For 11 of 15
stocks, NMFS authorizes no Level A harassment take over the duration of
South Fork Wind's planned activities; for the other four stocks, NMFS
authorizes no more than 4 takes by Level A harassment. As described
above, NMFS expects that marine mammals would likely move away from 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. Even
absent mitigation, no serious injury or mortality from construction
activities is anticipated or authorized.
NMFS has authorized an amount of Level B harassment take for all
marine mammal species based on either modeling or information reflected
in field data (e.g., monitoring reports, published group sizes); NMFS
based the number of authorized takes on whichever approach resulted in
a greater amount. This authorized take, by Level B harassment, reflects
behavioral disturbance directly in response to noise exposure (e.g.,
avoidance) or indirectly from associated impacts such as TTS or
masking. Both the amount and intensity of Level B harassment will be
reduced to the level of least practicable adverse impact through use of
required mitigation 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 avoidance, 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 impact or vibratory pile driving is
occurring. Therefore, NMFS expects that animals annoyed by project
sound would simply avoid the area during impact or vibratory pile
driving in favor of other, similar habitats. NMFS expects 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 would not be permanently displaced.
Feeding behavior is not likely to be significantly impacted, as
most prey species are mobile, broadly distributed throughout the
project area, and likely to only respond temporarily to exposure to
impact or vibratory pile-driving noise; 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. Soft starts would
allow mobile prey to move away from the source prior to exposure to any
noise levels that may cause physical injury. The use of noise
mitigation devices during impact pile driving of monopiles should
reduce sound levels to the degree that any mortality or injury of prey
will minimized. Use of bubble curtains, for example, is a key
mitigation measure in reducing injury and mortality of ESA-listed
salmon on the west coast during impact pile driving. NMFS recognizes
some mortality, physical injury and/or hearing impairment in marine
mammal prey may still occur but anticipates the amount of prey impacted
in this manner is minimal compared to overall prey availability. Any
behavioral responses by mobile marine mammal prey are expected to be
brief. For example, Jones et al. (2020) found that when squid
(Doryteuthis pealeii) were exposed to impact pile-driving noise, body
pattern changes, inking, jetting, and startle responses were observed
and nearly all squid exhibited at least one response. However, these
responses occurred primarily during the first eight impulses and
diminished quickly, indicating potential rapid, short-term habituation.
NMFS expects that other impacts such as stress or masking would occur
in fish that serve as marine mammal prey (Thomas et al. 2006); however,
those impacts would be limited to the duration of impact or vibratory
pile driving and, if prey were to move out the area in response to
noise, these impacts would be minimized.
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 notable
areas of biological significance for non-NARW marine mammals, other
than fin whales, known to exist within the Lease Area or potential
export cable route corridors. Although the SFWF and SFEC will be
constructed within a fin whale foraging BIA that exists east of Montauk
Point, NY, from March through October, the BIA is considerably larger
than the relatively small area within which impacts from monopile
installations may occur; this difference in scale will provide ample
access to foraging opportunities for fin whales within the remaining
area of the BIA. Vibratory pile-driving for installation of the
cofferdam will occur sometime between November 2022 and April 2023
(removal could occur any time prior to expiration of this IHA); this
schedule indicates that the overlap between cofferdam installation and
the fin whale foraging BIA would occur for only 36 non-continuous
hours. Monopiles will be installed on up to 16 days, which is a small
percentage of the duration of the fin whale foraging BIA. Impact pile
driving of one monopile per day (the limit under the IHA), and the
associated potential disturbance of foraging fin whales, will only
occur for 2-4 hours per day. The remaining 20-22 hours of the day will
provide fin whales the opportunity to forage undisturbed by noise
produced during monopile installation. Any disruption of feeding
behavior or avoidance of the project area by fin whales is expected to
be temporary, with habitat utilization by fin whales returning to
baseline once the disturbance ceases. In addition, a second, larger,
year-round fin whale foraging BIA, as well as foraging BIAs for sei,
humpback, and minke whales, are delineated to the east of the project
area. This second fin whale BIA will provide alternate suitable habitat
and food resources for foraging fin whales during construction
activities within the SFWF and SFEC. Please see LeBrecque et al. (2015)
for maps of all East Coast BIAs. It is extremely unlikely that feeding
(or non-feeding) whales would be able to detect any impact or vibratory
pile-driving noise, even near the western-most edges of the BIAs, given
the absorption of sound over the large propagation distances between
the Lease Area and the BIAs. Finally, there are no rookeries, mating,
or calving areas known to be biologically important to marine mammals
within the project area.
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.
NMFS concludes that exposures to marine mammals due to South Fork
Wind's activity 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 planned
activity would impact annual rates of recruitment or survival.
As described in the notice of the proposed IHA (86 FR 8490;
February 5, 2021), humpback and minke whales, and gray and harbor seals
are experiencing ongoing UMEs. For minke whales and seals, although the
ongoing UME is under investigation (as occurs for all UMEs), this event
does not provide cause for concern regarding population-level impacts.
The minke whale population abundance is greater than 20,000 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. 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). With regard
to humpback whales, the population is facing a UME wherein elevated
strandings have occurred since 2016 and are ongoing. A portion of the
whales have shown evidence of pre-mortem vessel strike; however, this
finding is not consistent across all whales examined and investigations
are ongoing. Animals involved in this UME primarily belong to the West
Indies Distinct Population Segment (DPS), of which the Gulf of Maine
stock is a part. While the MMPA designated Gulf of Maine stock is
relatively small (n=1,393), the most recent population estimate for the
ESA-designated West Indies DPS (of which animals belonging to the Gulf
of Maine stock also belong) is approximately 10,400 animals (Smith et
al., 2009). The UME is a cause for concern to the Gulf of Maine stock;
however, the taking associated with the issuance of the IHA is not
anticipated to contribute to the UME or impact the stock such that it
would affect annual rates or recruitment or survival. Authorized take
numbers, by Level A harassment, for the potentially impacted species
are very low (i.e., no more than 4 takes by Level A harassment
authorized 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. The suite of measures for vessel operation and monitoring
ensure risk of serious injury or mortality from ship strikes is
minimized such that the probability of a strike is de minimus.
Mortality and serious injury is neither expected, even absent
mitigation, nor authorized, and Level B harassment of humpback whales
and minke whales and gray, harbor, and harp seals will be reduced to
the level of least practicable adverse impact through implementation of
mitigation measures. As such, the authorized take of these species
would not exacerbate or compound the ongoing UMEs in any way.
North Atlantic Right Whales
NARWs are currently threatened by low population abundance, higher
than average mortality rates, and lower than average reproductive
rates. Pace et al. (2021) recently released an update of his NARW
abundance model. From 1990-2014, the female apparent survival rate
fluctuated around 0.96. In 2014, survival decreased to approximately
0.93 and hit an all-time low of 0.89 in 2017. However, in 2018,
survival increased dramatically back to around 0.95. The average
survival rate, based on the Pace et al. (2021) regime model from 2014-
2018, is approximately 0.93, slightly lower than the average long-term
rate from 1990-2014 (0.96). Since 1990, the estimated number of new
entrants (which can be used as a proxy for recruitment rates) has
widely fluctuated between 0 and 39 (Pace et al., 2021, NMFS 2021). In
the last 10 years (2011-2020), the average number of calves born into
the population is approximately 11. Unfortunately, not all calves born
into the population survive. For example, on December 22, 2020, a
newborn calf was sighted off El Hierro, an island in the Canary
Islands, but has not been subsequently detected with its mother,
suggesting it did not survive. More recently, a dead NARW calf was
reported stranded on February 13, 2021, along the Florida coast.
On November 24, 2021, a NARW and newborn calf were sighted east of
Pawleys Island, SC. On December 2, 2021, a second NARW and newborn calf
were sighted east of the northern tip of Cumberland Island, GA; the
NARW in this pair is currently entangled. On December 10, 2021, a third
NARW and newborn calf were sighted off Ossabaw Island, GA, and a fourth
pair was sighted off Morris Island, SC, on the same day. The fifth and
sixth NARW/calf pairs were sighted off Fernandina Beach, FL, and near
Nassau Sound, FL, respectively, on December 16, 2021. On December 18,
2021, a seventh NARW and calf were sighted off Amelia Island, FL, and
an eighth NARW/calf pair was sighted in Florida off the St. Johns River
entrance. A ninth NARW/calf pair was sighted off St. Simons Sound, GA,
on December 26, 2021. The most recent information on the status of
NARWs can be found in NMFS' 2021 Draft Stock Assessment Reports,
available online at: (www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments).
As described above, the project area represents part of an
important migratory area for NARWs. In addition, core year-round
foraging habitats have been identified south of Martha's Vineyard and
Nantucket to the east of the project area (Oleson et al., 2020);
however, abundance in this area in summer months remains low compared
to winter. It also appears the majority of sightings from June through
October (when South Fork Wind would be conducting most, if not all,
monopile installations) are concentrated approximately 90 km east of
the Lease Area, on Nantucket Shoals (sightings which triggered DMAs in
2019, 2020, and 2021) with occasional sightings or acoustic detections
within the project area triggering DMAs or acoustic Slow Zones. In
general, due to the current status of NARWs, and the spatial overlap of
the planned project with an area of biological significance for NARWs,
the potential impacts of the planned project on NARWs warrant
particular attention.
The IHA includes the following nine overarching mitigation measures
related to impact pile driving of monopiles, which are intended to
reduce both the number and intensity of NARW takes: (1) Time of year
restrictions; (2) time of day restrictions; (3) implementation of
clearance zones; (4) implementation of shutdown zones; (5) use of soft-
start; (6) use of noise mitigation technology; (7) use of PSOs to
visually observe for NARWs (with any detection within designated zones
triggering delay or shutdown); (8) use of PAM to acoustically detect
NARWs (with any detection within designated zones triggering delay or
shutdown); and (9) enhanced awareness of NARW presence (e.g.,
requirement to monitor NARW sighting network platforms to be aware of
NARW presence within or near the project area and/or transit
corridors). The specifics regarding these measures are dependent upon
the time of year. In
addition, the IHA includes mitigation measures for cofferdam
installation (and removal) which mirror a subset of those prescribed
for monopile installation (measures (2-5), (7) and (9)). There is no
time of year restriction on vibratory pile driving at the HDD site;
however, installation and removal will only require a maximum of 36
hours (18 hours for installation, 18 hours for removal). Finally,
mitigation measures for construction surveys include ramp up, and
measures (3-4), (7), and (9) listed above.
As described in Oleson et al. (2020), NARWs respond to
environmental changes and may use habitats intermittently over time.
They have been known to nearly abandon a frequently used foraging
habitat only to come back in future years in large numbers. In recent
years, NARWs have demonstrated actual shifts in distribution,
frequenting previously unrecognized foraging habitats. Sighting data
also indicate that NARWs may investigate a previously preferred
habitat, but not stay if the prey resource is insufficient, so some
habitats previously used no longer have high densities of NARWs (Davis
et al. 2017; Davies et al. 2019). As described above, NARW presence in
the project area is year-round; however, abundance during summer months
is low compared to winter months with spring and fall serving as
``shoulder seasons,'' wherein abundance waxes (fall) or wanes (spring).
During aerial surveys conducted from 2011-2015 in the project area,
NARW sightings occurred only December through April, with no sightings
from May through November (Kraus et al., 2016). There was not
significant variability in sighting rate among years, indicating
consistent annual seasonal use of the area by NARWs during those years
(Kraus et al., 2016). More recently, seasonal distribution patterns of
NARWs have been less consistent, with NARWs observed near the project
area in late summer and fall. As mentioned previously, in 2019, 2020,
and 2021, NARWs were observed in August and September around Nantucket
Shoals, triggering NMFS to establish a DMA that last several weeks each
year; however, as noted above, these sightings around Nantucket Shoals
are approximately 90 km east of the eastern-most edge of the project
area, well outside the Level B harassment zones created by project
activities. Given this year-round habitat usage and in recognition that
where whales may actually occur during project activities is largely
influenced by unpredictable, patchy prey availability, NMFS has
included a suite of mitigation measures designed to reduce impacts to
NARWs to the maximum extent practicable. However, even in consideration
of these recent habitat-use and distribution shifts, South Fork Wind
would be installing monopiles when the presence of NARWs is lower
(compared to winter), as reflected in the density data (Roberts et al.,
2020; Table 13). Up to a maximum of 16 monopiles will be installed,
making for relatively brief elevated sound levels in/near NARW habitat
(1 pile per day (at a maximum of 4 hours per day) for 16 intermittent
The most significant measure to minimize impacts to individual
NARWs during monopile installations is the seasonal moratorium on
impact pile driving of monopiles from January 1 through April 30, when
NARW abundance in the project area is expected to be greatest. In
addition, monopile installation must not occur in December unless an
unanticipated delay due to weather or technical problems, notified to
and approved by BOEM, arises that necessitates extending monopile
installation through December. NMFS also expects this measure to
greatly reduce the potential for mother-calf pairs to be exposed to
impact pile-driving noise above the Level B harassment threshold during
their annual migration through the project area. Mitigation and
monitoring measures outside of those months will greatly minimize any
take that may otherwise occur.
When monopile installation does occur, South Fork Wind is committed
to reducing the noise levels generated by pile driving to the lowest
levels practicable, such that they do not exceed a noise footprint
above that which was modeled, assuming a 10-dB attenuation. Use of a
soft start will allow animals to move away from (i.e., avoid) the sound
source prior to the elevation of the hammer energy to the level
maximally needed to install the pile (South Fork Wind will not use a
hammer energy greater than necessary to install piles). To reduce the
daily amount of time the area may be ensonified (and thereby decrease
daily exposure risk), South Fork Wind will drive no more than one
monopile per day. NMFS is also requiring South Fork Wind to apply a
dBBC, or a single BBC coupled with an additional noise mitigation
device, to ensure sound generated from the project does not exceed that
modeled (assuming 10-dB reduction) at given ranges to harassment
isopleths, and to minimize noise levels to the lowest level
practicable. Double BBCs are successfully and widely applied across
European wind development efforts, and are known to reduce noise levels
more than single BBC alone (e.g., see Table 3, Bellman et al., 2020).
Further, NMFS will be reviewing South Fork Wind's BBC (or dBBC)
operational reports to ensure that deployments are successful (e.g.,
the maximum air flow rate is being used during pile driving).
NMFS expects that any avoidance of the project area by NARWs due to
exposure to monopile installation, cofferdam/casing pipe installation,
and construction surveys would be temporary in nature, and that any
NARW that avoids the project area during construction would not be
permanently displaced. The IHA authorizes a total of 13 takes, by Level
B harassment only, of NARWs (4 based on the maximum impact pile-driving
design scenario for impact pile driving, 6 from vibratory pile driving,
and 3 from construction survey using boomers and/or sparkers). Although
unlikely, this may comprise 13 individuals taken once or fewer than 13
individuals taken on multiple days. For those individuals where take is
limited to occurring once, behavioral disturbance and other Level B
harassment impacts that may occur during exposure to elevated noise
levels (e.g., masking, stress) are likely insignificant. As described
in the notice of proposed IHA, nearly all Population Consequences of
Disturbance (PCOD) studies and experts agree that infrequent exposures
from a single day or less are unlikely to impact individual fitness,
let alone lead to population-level effects.
There is potential for the same individual NARW to be exposed on
multiple days; however, the risk is low, and given the total number of
anticipated exposures, even if a single individual were exposed on more
than one day, it would not be more than a few (and that would mean that
fewer total individuals were exposed). Impact pile driving of monopiles
is limited to one pile per day and may only begin in the absence of
NARWs (based on clearance zones, as determined by visual and PAM PSOs).
If impact pile driving has commenced, NMFS anticipates NARWs would
avoid the area, utilizing nearby habitats not impacted by monopile
installation. However, impact pile driving must be shutdown if a NARW
is sighted at any distance, unless a shutdown is not feasible due to
risk of injury or loss of life. Depending on visibility conditions,
shutdown may occur based on a NARW sighting in the Level B harassment
zone, thereby minimizing the duration and intensity of exposure above
the Level B harassment threshold. NMFS anticipates
that if NARWs go undetected and they are exposed to impact pile-driving
noise from monopile installation, it would be at noise levels only
slightly above the Level B harassment threshold, as it is unlikely a
NARW would approach the impact pile-driving locations to the degree
that they would purposely expose themselves to very high noise levels.
NMFS also anticipates that the combination of PAM and visual observers
(as well as communication protocols with other South Fork Wind vessels,
and other heightened awareness efforts such as daily monitoring of NARW
sighting databases) will result in maximum detection effectiveness such
that as a NARW approaches the source (and thereby could be exposed to
higher noise energy levels), PSO detection efficacy will increase, the
whale will be detected, and a shutdown (if feasible) will occur. In
addition, the implementation of a soft start will provide an
opportunity for whales to move away from the source, reducing received
levels. Although the Level B harassment zone for vibratory pile driving
is large (approximately 36 km), the cofferdam, if South Fork Wind
chooses to install one, would be installed nearshore over a short
timeframe, at a distance approximately 70 km from the Lease Area.
Further, South Fork Wind has indicated that vibratory pile driving for
cofferdam installation would likely occur upon the effectiveness of the
IHA in 2022, while monopile driving is likely to occur several months
later in 2023. NARWs will, therefore, not be exposed to both vibratory
and impact pile driving on any given day. Finally, for construction
surveys, the maximum distance to the Level B harassment isopleth is 141
m. The authorized take, by Level B harassment only, associated with
construction surveys is to account for any NARW PSOs may miss when HRG
acoustic sources are active. However, because of the short maximum
distance to the Level B harassment isopleth (141 m), the requirement
that vessels maintain a distance of 500 m from any NARWs, and the fact
whales are unlikely to remain in close proximity to a construction
survey vessel for any length of time, any exposure to Level B
harassment (the only type that is authorized for construction survey),
if any, would be very brief and exposure of the same individual on
multiple days is unlikely. To further minimize exposure, ramp-up of
boomers, sparkers, and Chirps must be delayed during the clearance
period if PSOs detect a NARW (or any other ESA-listed species) within
500 m of the acoustic source. Operation of this equipment (if active)
must be shut down if a NARW is sighted within 500 m. Overall, given the
information above, the magnitude of any Level B harassment is expected
to be low.
There are no known NARW mating or calving areas within the project
area; however, as described above, it is on the far western edge of a
larger core foraging area (Oleson et al., 2020). If a NARW does avoid
foraging within the project area, there is ample foraging habitat
adjacent to the project area that would not be not ensonified by the
project's impact or vibratory pile-driving noise. For example, the
presence of NARWs on Nantucket Shoals in the fall in recent years
indicates that this habitat is a foraging hotspot. Given that the
nearest NARWs detections on Nantucket Shoals are approximately 90 km
away from the eastern-most edge of the project area where impact pile
driving monopiles would occur, noise from the project would not impact
NARW foraging in this habitat. Further, monopile driving would be
limited to a maximum of four hours per day; therefore, if foraging
activity is disrupted due to pile driving, any disruption would be
brief as NARWs would likely resume foraging after pile driving ceases.
As described above, due to the temporary nature of disturbance from
South Fork Wind's project activities and the availability of similar
habitat and resources in the surrounding area, the impacts to NARWs and
the food sources that they utilize are not expected to cause
significant or long-term consequences for individual NARWs or their
population. Feeding NARWs that may be temporarily displaced during
South Fork Wind's construction activities are expected to be able to
resume foraging once they have moved away from areas with disturbing
levels of underwater noise or when the activity ceases. Even repeated
Level B harassment of some smaller number (13 or less) of individuals,
as a subset of the overall stock, over several days 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.
With respect to potential vessel strike, the IHA includes an
extensive suite of mitigation measures designed to avoid ship strike
and close approaches, including, but not limited it: Separation
distances; limiting vessel speed to 10 kts or less (except in the case
of transiting crew transfer vessels in the transit route under specific
conditions, including use of observers and PAM for crew transfer
vessels travelling in excess of 10 kts (outside of any DMA or SMA);
training and communication protocols; and monitoring of NARW sighting
resources. As described above, given the anticipated effectiveness of
these measures in addition to the already very low probability of a
vessel strike, take from vessel strike is not anticipated or
authorized.
As described above, NARWs are experiencing an ongoing UME, the
primary drivers of which are entanglement and ship strikes leading to
serious injury or mortality. The loss of even one individual could
significantly impact the population. However, no mortality, serious
injury, or injury of NARWs as a result of the project is expected or
authorized. Any disturbance to NARWs due to exposure to impact or
vibratory pile-driving noise (Level B harassment) or construction
surveys is expected to result in temporary avoidance of the immediate
area of construction. As no injury or mortality is expected or
authorized, and Level B harassment of NARWs will be reduced to the
level of least practicable adverse impact through use of mitigation
measures, the authorized number of takes of NARWs would not exacerbate
or compound the effects of the ongoing UME in any way.
NMFS concludes that (1) exposures of NARWs to impact pile-driving
noise from monopile installation will be greatly reduced due to
seasonal restrictions on monopile installation, and (2) additional
required mitigation measures would ensure that any exposures above the
Level B harassment threshold during months outside of the seasonal
restriction on monopile installation would result in only short-term
effects to individuals exposed. With implementation of the mitigation
requirements, take by Level A harassment is not expected to occur and
is therefore not authorized. Potential impacts associated with Level B
harassment would include low-level, temporary behavioral modifications,
most likely in the form of avoidance behavior or potential alteration
of vocalizations (due to masking). Although unlikely given the NARW-
specific mitigation, TTS is another potential form of Level B
harassment that could result in brief periods of slightly reduced
hearing sensitivity, affecting behavioral patterns by making it more
difficult to hear or interpret acoustic cues within the frequency range
(and slightly above) of sound produced during impact pile driving;
however, it is unlikely that any individuals would be exposed to impact
or vibratory pile driving, or active specified HRG acoustic sources at
distances or for durations that would
have more than brief and minor impacts, which would not be expected to
affect the fitness of any individuals.
Although acoustic masking may occur, based on the acoustic
characteristics of noise associated with pile driving (e.g., frequency
spectra, short duration) and construction surveys (e.g., intermittent
signals), NMFS expects masking effects to be minimal (e.g., impact or
vibratory pile driving) to none (e.g., construction surveys). Masking
events that might be considered Level B harassment have already been
accounted for in the exposure analysis as they would be expected to
occur within the behavioral harassment zones predetermined for impact
and vibratory pile driving.
Avoidance of the SFWF or SFEC during construction would represent a
potential manifestation of behavioral disturbance. Although the project
area is located within the migratory BIA for NARWs, impact pile driving
of monopile foundations would only occur on up to 16 days (one pile
would be driven per day for a maximum of 4 hours), and vibratory pile
driving for cofferdam installation/removal would be limited to a
maximum of 36 hours (18 hours for installation and an additional 18
hours for removal) of the 12 months of activities covered in this IHA.
If a casing pipe and support piles are installed, impact hammering and
vibratory pile driving would be limited to a total of 8 hours. Further,
seasonal restrictions preclude monopile installation during the months
in which NARW occurrence is expected to be highest (January through
April). Monopile installation is also prohibited in December, unless
unanticipated delays due to weather or technical problems arise that
necessitate extending installations into December. If avoidance of the
project area by NARWs occurs, it is expected to be temporary. Finally,
consistent NARW utilization of the habitat south of Martha's Vineyard
and Nantucket (Oleson et al., 2020) indicates that suitable alternative
nearby habitat would be available to NARWs that might avoid the project
area during construction.
In order to evaluate whether or not individual behavioral responses
(in combination with other stressors) impact animal populations,
scientists have developed theoretical frameworks which can then be
applied to particular case studies when the supporting data are
available. One such framework is the Population Consequences of
Disturbance Model (PCoD), which attempts to assess the combined effects
of individual animal exposures to stressors at the population level
(NAS 2017). Nearly all PCoD studies (considering multiple marine mammal
species) and experts agree that infrequent exposures of a single day or
less are unlikely to impact individual fitness, let alone lead to
population-level effects (Christiansen and Lusseau 2015; Dunlop et al.,
2021; Harwood et al., 2014; Harwood and Booth 2016; Keen et al., 2021;
King et al., 2015; New et al., 2014; Pirotta et al., 2018; Southall et
al., 2007; Villegas-Amtmann et al., 2015). Since NMFS expects that any
driving of monopiles, 36 hours over 6 days for vibratory pile driving
of a cofferdam, or 8 hours over 2-4 days for impact hammering and
vibratory pile driving if the casing pipe is installed (and likely less
given probable avoidance response)), and the likelihood or repeat
exposures across multiple days to the same individuals is low (but
possible), any behavioral responses that would occur due to animals
being exposed to noise produced during construction activities are
expected to be temporary, with behavior returning to a baseline state
shortly after the acoustic stimuli ceases. NARWs may temporarily avoid
the immediate project area, but are not expected to permanently abandon
the habitat that contains the SFWF and SFEC. Given this, and NMFS'
evaluation of the available PCoD studies, any such behavioral responses
are not expected to impact an individual animal's health or fitness, or
have effects on individual animal's survival or reproduction, much less
impact the population.
In the IHA, up to 13 individual NARWs could be behaviorally
disturbed incidental to all construction activities, or some fewer
number of individual NARWs could be behaviorally disturbed on more than
one day, but no more than 13 total instances of take would occur. Since
most monopile installations would occur during a period when NARW
occurrence is much lower than January through April (when impact pile
driving of monopiles is, under no circumstances, allowed to proceed)
and considering the required mitigation and monitoring, it is highly
unlikely a single NARW would incur all the authorized take (i.e., the
same whale taken on 13 different days). Because the project area is
both a migratory corridor and foraging area (although to a lesser
extent than the area south of Martha's Vineyard and Nantucket), it is
more likely that a subset of whales will be exposed only once and some
subset would potentially be exposed on more than one day (e.g., 7
individuals taken in one day each and 3 individuals taken on two days
each).
While there may be temporary impacts to behaviors such as foraging
near impact and vibratory pile-driving activities, meaningful shifts in
habitat use, distribution, or foraging success are not anticipated. As
described above, NMFS expects NARWs to avoid areas with high noise
levels. Given the suite of monitoring and mitigation measures in the
IHA specific to NARWs, if an individual is exposed to noise levels that
may result in Level B harassment, this exposure would likely occur at
distance (i.e., farther from the noise source). Because sound loses
energy as it moves away from the source, more distant received levels
would be relatively low; any resulting behavioral changes are also
anticipated to be low in severity. Based on the information above, NMFS
does not anticipate that any Level B harassment of NARWs that may
result from South Fork Wind's planned impact and vibratory pile driving
would impact the reproduction or survival of any individual NARWs, much
less annual rates of recruitment or survival.
In summary and as described above, the following factors primarily
support NMFS' determination that the impacts resulting from the South
Fork Wind's construction activites are not expected to adversely affect
any marine mammal species or stock through effects on annual rates of
recruitment or survival:
No mortality or serious injury is anticipated or
authorized;
Where Level A harassment is authorized, the amount of
Level A harassment is low for all impacted species and would be in the
form of a slight PTS;
Level B harassment would be in the form of behavioral
disturbance, primarily resulting in avoidance of the project area
around where impact or vibratory pile driving is occurring, and some
low-level TTS and masking that may limit the detection of acoustic cues
for relatively brief amounts of time.
Repeated disturbance to some individuals, including a very
limited number of NARWs (potentially up to a few individuals on a few
days), may occur; however, any resulting behavioral reactions from
exposure to acoustic impacts from the specified HRG acoustic sources,
and impact and vibratory pile driving (e.g., avoidance, short-term
cessation of foraging) are not expected to result in impacts to any
stock's reproduction or survival.
Total authorized take as a percentage of population is
very low for all species and stocks impacted (i.e., less than 4 percent
for all stocks, and less than 1 percent for 10 of 15 stocks);
Areas of similar habitat value are available for marine
mammals that may temporarily vacate the project area during
construction activities covered in this IHA;
Effects on species that serve as prey for marine mammals
from the activity 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;
A biologically important migratory area exists for NARWs
within the Lease Area and potential export cable route corridors;
however, the required seasonal moratorium on monopile installations is
expected to largely avoid impacts to the NARW migration, as described
above. The project area encompasses a subset of a core year-round
foraging habitat; however, there are areas within this core foraging
habitat that would not be impacted by project noise. Further, any noise
within the project area would be temporary given the limitation to the
amount of pile driving for the project, the limitations on the number
of piles installed per day, and time of day restrictions limiting when
pile driving could occur. Moreover, potential for exposure from noise
causing behavioral disruptions such as a cessation of foraging is
further reduced through implementation of the required mitigation
measures (e.g., requiring a delay in pile driving should a NARW be
observed at any distance by PSOs on the pile-driving/dedicated PSO
vessels would limit any disruption of foraging).
There are no known important feeding, breeding or calving
areas in the project area for any other marine mammals, except fin
whales. A foraging BIA exists for fin whales from March through October
within the Lease Area and ECR, but ample alternate suitable foraging
habitat is available in the immediate vicinity of the project area. A
second fin whale BIA, and BIAs for humpback, sei, and minke whales are
delineated to the east of the project area; however, received levels
(if any) within these areas would be extremely low given the distance
to the BIAs from the project area; therefore, exposure to these low
levels (while possibly audible) are not expected to result in
disruption of foraging within the BIAs.
The required mitigation measures, including visual and
acoustic monitoring, clearance zones, soft start, and ramp-up, are
expected to minimize potential impacts to marine mammals and effect the
least practicable adverse impact on all 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 monitoring and mitigation
measures, NMFS finds that the total marine mammal take from South Fork
Wind's planned activity will have a negligible impact on all affected
marine mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is less than one third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
NMFS authorizes incidental take of 15 marine mammal stocks. The
total amount of take authorized is less than 4 percent for five of
these stocks, and less than 1 percent for the 10 remaining stocks
(Table 23), which NMFS finds are small numbers of marine mammals
relative to the estimated overall population abundances for those
stocks.
Based on the analysis contained herein of the planned activity
(including the required mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS 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.
Section 7(a)(2) of the ESA (16 U.S.C. 1531 et seq.) requires that
each Federal agency insure that any action it authorizes, funds, or
carries out is not likely to jeopardize the continued existence of any
endangered or threatened species or result in the destruction or
adverse modification of designated critical habitat. To ensure ESA
compliance for the issuance of IHAs, NMFS consults internally, in this
case with the NMFS Greater Atlantic Regional Fisheries Office (GARFO),
whenever we propose to authorize take for endangered or threatened
The NMFS Office of Protected Resources Permits and Conservation
Division is authorizing the incidental take of four species of marine
mammals that are listed under the ESA: The NARW, fin, sei and sperm
whale. NMFS requested initiation of consultation under Section 7 of the
ESA with NMFS GARFO on February 8, 2021, for the issuance of this IHA.
On October 1, 2021, NMFS GARFO issued a Biological Opinion concluding
that these activities may adversely affect but are not likely to
jeopardize the continued existence of NARW, fin, sei and sperm whales
or adversely modify their critical habitat. The Biological Opinion can
be found at: https://www.fisheries.noaa.gov/action/incidental-take-authorization-south-fork-wind-llc-construction-south-fork-offshore-wind.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an
incidental harassment authorization) with respect to potential impacts
on the human environment. In compliance with NEPA, as implemented by
the regulations published by the Council on Environmental Quality (40
CFR parts 1500-1508 (1978)), BOEM prepared an Environmental Impact
Statement (EIS) to consider the direct, indirect and cumulative effects
to the human environment resulting from the South Fork Wind project.
NMFS has participated as a cooperating agency on BOEM's EIS and
provided technical expertise to BOEM in development of the document as
it pertains to NMFS trust resources, including marine mammals. BOEM's
Draft EIS was made available for public comment from January 8, 2021 to
February 22, 2021 online at: https://www.boem.gov/renewable-energy/state-activities/south-fork. BOEM published a Notice of Availability of
the Final EIS on August 20, 2021. As a cooperating agency, NMFS
reviewed and provided comments related to NMFS trust resources,
including marine mammals, on the Draft EIS and cooperating agency
review draft of the Final EIS. In
compliance with NEPA and the CEQ regulations (40 CFR 1506.3), as well
as NOAA Administrative Order 216-6 and its Companion Manual, NMFS has
reviewed BOEM's Final EIS, determined it to be sufficient, and adopted
that Final EIS which adequately evaluates the direct, indirect and
cumulative impacts of NMFS's proposed action to issue an IHA under the
MMPA to South Fork Wind for its offshore commercial wind project. NMFS
has further determined that its comments and suggestions as a
cooperating agency have been satisfied and recirculation of BOEM's EIS
is therefore unnecessary (40 CFR 1506.3(c)). NMFS signed a joint Record
of Decision (ROD) on November 24, 2021.
NMFS has issued an IHA to South Fork Wind authorizing take of
marine mammals incidental to pile driving (vibratory and impact) and
surveys utilizing specified HRG equipment associated with construction
of the South Fork Wind Offshore Wind Project offshore New York,
Massachusetts, and Rhode Island, for a period of one year, from
November 15, 2022, through November 14, 2023. South Fork Wind is
required to abide by all mitigation, monitoring, and reporting
requirements in the IHA.
Dated: January 3, 2022.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries