[Federal Register Volume 85, Number 29 (Wednesday, February 12, 2020)]
[Notices]
[Pages 7926-7950]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-02661]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XR010]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Marine Site Characterization
Surveys Off of New Jersey and New York
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization; request
for comments on proposed authorization and possible renewal.
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SUMMARY: NMFS has received a request from Atlantic Shores Offshore
Wind, LLC (Atlantic Shores) for authorization to take marine mammals
incidental to marine site characterization surveys off the coasts of
New York and New Jersey in the area of the Commercial Lease of
Submerged Lands for Renewable Energy Development on the Outer
Continental Shelf (OCS-A 0499) and along potential submarine cable
routes to a landfall location in New York or New Jersey. Pursuant to
the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on
its proposal to issue an incidental harassment authorization (IHA) to
incidentally take marine mammals during the specified activities. NMFS
is also requesting comments on a possible one-year renewal that could
be issued under certain circumstances and if all requirements are met,
as described in Request for Public Comments at the end of this notice.
NMFS will consider public comments prior to making any final decision
on the issuance of the requested MMPA authorizations and agency
responses will be summarized in the final notice of our decision.
DATES: Comments and information must be received no later than March
13, 2020.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service. Physical comments should be sent to
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments
should be sent to [email protected].
Instructions: NMFS is not responsible for comments sent by any
other method, to any other address or individual, or received after the
end of the comment period. Comments received electronically, including
all attachments, must not exceed a 25-megabyte file size. Attachments
to electronic comments will be accepted in Microsoft Word or Excel or
Adobe PDF file formats only. All comments received are a part of the
public record and will generally be posted online at
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable without change.
All personal identifying information (e.g., name, address) voluntarily
submitted by the commenter may be publicly accessible. Do not submit
confidential business information or otherwise sensitive or protected
information.
FOR FURTHER INFORMATION CONTACT: Jordan Carduner, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the applications
and supporting documents, as well as a list of the references cited in
this document, may be obtained by visiting the internet at:
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable. In case of
problems accessing these documents, please call the contact listed
above.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are issued or, if the taking is limited to harassment, a notice of a
proposed incidental take authorization may be provided to the public
for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and
[[Page 7927]]
other ``means of effecting the least practicable adverse impact'' on
the affected species or stocks and their habitat, paying particular
attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of such species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of such takings are set forth.
The definitions of all applicable MMPA statutory terms cited above
are included in the relevant sections below.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must evaluate our proposed action (i.e., the promulgation of
regulations and subsequent issuance of incidental take authorization)
and alternatives with respect to potential impacts on the human
environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 of the Companion Manual for NAO 216-6A,
which do not individually or cumulatively have the potential for
significant impacts on the quality of the human environment and for
which we have not identified any extraordinary circumstances that would
preclude this categorical exclusion. Accordingly, NMFS has
preliminarily determined that the proposed action qualifies to be
categorically excluded from further NEPA review.
Information in Atlantic Shores' application and this notice
collectively provide the environmental information related to proposed
issuance of these regulations and subsequent incidental take
authorization for public review and comment. We will review all
comments submitted in response to this notice prior to concluding our
NEPA process or making a final decision on the request for incidental
take authorization.
Summary of Request
On November 5, 2019, NMFS received a request from Atlantic Shores
for an IHA to take marine mammals incidental to marine site
characterization surveys off the coast of New York and New Jersey in
the area of the Commercial Lease of Submerged Lands for Renewable
Energy Development on the Outer Continental Shelf (OCS-A 0499) and
along potential submarine cable routes to a landfall location in either
New York or New Jersey. A revised application was received on December
30, 2019. NMFS deemed that request to be adequate and complete.
Atlantic Shores' request is for the take of 12 marine mammal species by
Level B harassment. Neither Atlantic Shores nor NMFS expects serious
injury or mortality to result from this activity and the activity is
expected to last no more than one year, therefore, an IHA is
appropriate.
Description of the Proposed Activity
Overview
Atlantic Shores proposes to conduct marine site characterization
surveys, including high-resolution geophysical (HRG) and geotechnical
surveys, in the area of Commercial Lease of Submerged Lands for
Renewable Energy Development on the Outer Continental Shelf #OCS-A 0499
(Lease Area) and along potential submarine cable routes to landfall
locations in either New York or New Jersey.
The purpose of the proposed surveys are to support the preliminary
site characterization, siting, and engineering design of offshore wind
project facilities including wind turbine generators, offshore
substations, and submarine cables within the Lease Area and along
export cable routes (ECRs). As many as three survey vessels may be
operate concurrently as part of the proposed surveys. Underwater sound
resulting from Atlantic Shores' proposed site characterization surveys
has the potential to result in incidental take of marine mammals in the
form of behavioral harassment.
Dates and Duration
The estimated duration of the surveys is expected to be up to 350
total days between April 2020 and April 2021. This schedule is based on
24-hour operations and includes potential down time due to inclement
weather.
Specific Geographic Region
Atlantic Shores' survey activities would occur in the Northwest
Atlantic Ocean within Federal waters. Surveys would occur in the Lease
Area and along potential submarine cable routes to landfall locations
in either New York or New Jersey (see Figure 1-1 in the IHA
application).
Detailed Description of the Specified Activities
Atlantic Shores' proposed marine site characterization surveys
include high-resolution geophysical (HRG) and geotechnical survey
activities. These survey activities would occur within the both the
Lease Area and within ECRs between the Lease Area and the coasts of New
York and New Jersey. The Lease Area is approximately 742 square
kilometers (km) (183,353 acres) and is located approximately 18
nautical miles (nm; 34 km) southeast of Atlantic City, New Jersey (see
Figure 1-1 in the IHA application). For the purpose of this IHA the
Lease Area and ECRs are collectively referred to as the Project Area.
Geophysical and shallow geotechnical survey activities are
anticipated to be supported by vessels which will maintain a speed of
approximately to 3.5 knots (kn) while transiting survey lines. The
proposed HRG and geotechnical survey activities are described below.
Geotechnical Survey Activities
Atlantic Shores' proposed geotechnical survey activities would
include the following:
Sample boreholes to determine geological and geotechnical
characteristics of sediments;
Deep cone penetration tests (CPTs) to determine
stratigraphy and in situ conditions of the deep surface sediments; and
Shallow CPTs to determine stratigraphy and in situ
conditions of the near surface sediments.
Geotechnical investigation activities are anticipated to be
conducted from a drill ship equipped with dynamic positioning (DP)
thrusters. Impact to the seafloor from this equipment will be limited
to the minimal contact of the sampling equipment, and inserted boring
and probes.
In considering whether marine mammal harassment is an expected
outcome of exposure to a particular activity or sound source, NMFS
considers the nature of the exposure itself (e.g., the magnitude,
frequency, or duration of exposure), characteristics of the marine
mammals potentially exposed, and the conditions specific to the
geographic area where the activity is expected to occur (e.g., whether
the activity is planned in a foraging area, breeding area, nursery or
pupping area, or other biologically important area for the species). We
then consider the expected response of the exposed animal and whether
the nature and duration or intensity of that response is expected to
cause disruption of behavioral patterns (e.g., migration, breathing,
nursing, breeding, feeding, or sheltering) or injury.
Geotechnical survey activities would be conducted from a drill ship
equipped with DP thrusters. DP thrusters would be used to position the
sampling vessel on station and maintain position at each sampling
location during the sampling
[[Page 7928]]
activity. Sound produced through use of DP thrusters is similar to that
produced by transiting vessels and DP thrusters are typically operated
either in a similarly predictable manner or used for short durations
around stationary activities. NMFS does not believe acoustic impacts
from DP thrusters are likely to result in take of marine mammals in the
absence of activity- or location-specific circumstances that may
otherwise represent specific concerns for marine mammals (i.e.,
activities proposed in area known to be of particular importance for a
particular species), or associated activities that may increase the
potential to result in take when in concert with DP thrusters. In this
case, we are not aware of any such circumstances. Therefore, NMFS
believes the likelihood of DP thrusters used during the proposed
geotechnical surveys resulting in harassment of marine mammals to be so
low as to be discountable. As DP thrusters are not expected to result
in take of marine mammals, these activities are not analyzed further in
this document.
Field studies conducted off the coast of Virginia to determine the
underwater noise produced by CPTs and borehole drilling found that
these activities did not result in underwater noise levels that
exceeded current thresholds for Level B harassment of marine mammals
(Kalapinski, 2015). Given the small size and energy footprint of CPTs
and boring cores, NMFS believes the likelihood that noise from these
activities would exceed the Level B harassment threshold at any
appreciable distance is so low as to be discountable. Therefore,
geotechnical survey activities, including CPTs and borehole drilling,
are not expected to result in harassment of marine mammals and are not
analyzed further in this document.
Geophysical Survey Activities
Atlantic Shores has proposed that HRG survey operations would be
conducted continuously 24 hours per day. Based on 24-hour operations,
the estimated total duration of the proposed activities would be
approximately 350 survey days (including 210 survey days within the
Lease Area and 140 survey days within the ECR areas; see Table 1).
These estimated durations include estimated weather down time.
Table 1--Summary of Proposed HRG Survey Segments
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Duration
Survey segment (survey days)
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Lease Area.............................................. 210
Northern ECR............................................ 80
Southern ECR............................................ 60
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All areas combined.................................... 350
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The HRG survey activities will be supported by vessels of
sufficient size to accomplish the survey goals in each of the specified
survey areas. It is assumed surveys in each of the identified survey
areas will be executed by a single vessel during any given campaign
(i.e., no more than one survey vessel would operate in the Lease Area
at any given time, but there may be one survey vessel operating in the
Lease Area and one vessel operating each of the ECR areas concurrently,
i.e., three vessels). HRG equipment will either be mounted to or towed
behind the survey vessel at a typical survey speed of approximately 3.5
kn (6.5 km) per hour. The geophysical survey activities proposed by
Atlantic Shores would include the following:
Depth sounding (multibeam depth sounder) to determine
water depths and general bottom topography (currently estimated to
range from approximately 5 meters (m) to 40 m in depth;
Magnetic intensity measurements (gradiometer) for
detecting local variations in regional magnetic field from geological
strata and potential ferrous objects on and below the bottom;
Seafloor imaging (side scan sonar) for seabed sediment
classification purposes, to identify natural and man-made acoustic
targets resting on the bottom as well as any anomalous features;
Shallow penetration sub-bottom profiler (pinger/chirp) to
map the near surface stratigraphy (top zero to five m soils below
seabed); and
Medium penetration sub-bottom profiler (chirps/parametric
profilers/sparkers) to map deeper subsurface stratigraphy as needed
(soils down to 75 m to 100 m below seabed).
Table 2 identifies the representative survey equipment that may be
used in support of planned geophysical survey activities. The make and
model of the listed geophysical equipment may vary depending on
availability and the final equipment choices will vary depending upon
the final survey design, vessel availability, and survey contractor
selection. Geophysical surveys are expected to use several equipment
types concurrently in order to collect multiple aspects of geophysical
data along one transect. Selection of equipment combinations is based
on specific survey objectives.
Table 2--Summary of HRG Survey Equipment Proposed for Use by Atlantic Shores
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Pulse
HRG equipment category Specific HRG equipment Operating frequency range Source level Beamwidth Typical pulse repetition
(kHz) (dB rms) (degrees) duration (ms) rate
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Single Beam Echosounders............ Kongsberg EA 400....... 38 to 200................ 222.8 31 0.3 10
Teledyne ODOM Echotrac 24....................... 224.6 20 0.3 10
CVM.
Sparker............................. Applied Acoustics Dura- 0.25 to 5................ 211.4 180 2.5 1.6
Spark 240.
Sub-Bottom Profiler................. Edgetech 2000-DSS...... 2 to 16.................. 178 24 6.3 10
Edgetech 216........... 2 to 16.................. 179 17, 20, or 24 10 10
Edgetech 424........... 4 to 24.................. 180 71 4 2
Edgetech 512i.......... 0.5 to 12................ 180 80 10 10
Teledyne Benthos Chirp 2 to 7................... 197 100 15 10
III.
....................... 10 to 20................. 205 30 15 10
Kongsberg GeoPulse..... 2 to 12.................. 214 30, 40, or 55 16 10
Innomar SES-2000 Medium- 85 to 115................ 241 2 2 40
100 Parametric.
Boomer.............................. Applied Acoustics S- 0.01 to 20............... 203 80 0.8 3
Boom Triple Plate.
Applied Acoustics S- 0.01 to 20............... 195 98 0.8 3
Boom.
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[[Page 7929]]
The deployment of HRG survey equipment, including the equipment
planned for use during Atlantic Shores' proposed activity, produces
sound in the marine environment that has the potential to result in
harassment of marine mammals. Proposed mitigation, monitoring, and
reporting measures are described in detail later in this document
(please see Proposed Mitigation and Proposed Monitoring and Reporting).
Description of Marine Mammals in the Area of Specified Activity
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). All species that could
potentially occur in the proposed survey areas are included in Table 4-
1 of the IHA application. However, the temporal and/or spatial
occurrence of several species listed in Table 7-2 of the IHA
application is such that take of these species is not expected to occur
either because they have very low densities in the project area or are
known to occur further offshore than the project area. These are: The
blue whale (Balaenoptera musculus), Bryde's whale (Balaenoptera edeni),
Cuvier's beaked whale (Ziphius cavirostris), four species of
Mesoplodont beaked whale (Mesoplodon spp.), dwarf and pygmy sperm whale
(Kogia sima and Kogia breviceps), short-finned pilot whale
(Globicephala macrorhynchus), northern bottlenose whale (Hyperoodon
ampullatus), killer whale (Orcinus orca), pygmy killer whale (Feresa
attenuata), false killer whale (Pseudorca crassidens), melon-headed
whale (Peponocephala electra), striped dolphin (Stenella coeruleoalba),
white-beaked dolphin (Lagenorhynchus albirostris), pantropical spotted
dolphin (Stenella attenuata), Fraser's dolphin (Lagenodelphis hosei),
rough-toothed dolphin (Steno bredanensis), Clymene dolphin (Stenella
clymene), spinner dolphin (Stenella longirostris), hooded seal
(Cystophora cristata), and harp seal (Pagophilus groenlandicus). As
take of these species is not anticipated as a result of the proposed
activities, these species are not analyzed further.
Table 3 summarizes information related to the population or stock,
including regulatory status under the MMPA and ESA and potential
biological removal (PBR), where known. For taxonomy, we follow
Committee on Taxonomy (2018). PBR is defined by the MMPA as the maximum
number of animals, not including natural mortalities, that may be
removed from a marine mammal stock while allowing that stock to reach
or maintain its optimum sustainable population (as described in NMFS'
SARs). While no mortality is anticipated or authorized here, PBR is
included here as a gross indicator of the status of the species and
other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total 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 and are available in the
2019 draft Atlantic SARs (Hayes et al., 2019), available online at:
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region.
Table 3--Marine Mammals Known to Occur in the Survey Area That May Be Affected by Atlantic Shores' Proposed Activity
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MMPA and ESA Stock abundance (CV,
status; Nmin, most recent Predicted Annual Occurrence in
Common name (scientific name) Stock strategic (Y/N) abundance survey) abundance (CV) PBR \4\ M/SI project area
\1\ \2\ \3\ \4\
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Toothed whales (Odontoceti)
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Sperm whale (Physeter North Atlantic....... E; Y 4,349 (0.28; 3,451; 5,353 (0.12) 6.9 0.0 Rare.
macrocephalus). n/a).
Long-finned pilot whale W. North Atlantic.... --; N 39,215 (0.3; 30,627; 18,977 (0.11) 306 21 Rare.
(Globicephala melas). n/a). \5\
Atlantic white-sided dolphin W. North Atlantic.... --; N 93,233 (0.71; 37,180 (0.07) 544 26 Common.
(Lagenorhynchus acutus). 54,443; n/a).
Bottlenose dolphin (Tursiops W. North Atlantic, --; N 62,851 (0.23; 97,476 (0.06) 519 28 Common offshore.
truncatus). Offshore. 51,914; 2011). \5\
W. North Atlantic, --; N 6,639 (0.41; 4,759; 48 6.1-13. Common nearshore.
Coastal Migratory. 2015). 2
Common dolphin \6\ (Delphinus W. North Atlantic.... --; N 172,825 (0.21; 86,098 (0.12) 1,452 419 Common.
delphis). 145,216; 2011).
Atlantic spotted dolphin (Stenella W. North Atlantic.... --; N 39,921 (0.27; 55,436 (0.32) 320 0 Common.
frontalis). 32,032; 2012).
Risso's dolphin (Grampus griseus). W. North Atlantic.... --; N 35,493 (0.19; 7,732 (0.09) 303 54.3 Rare.
30,289; 2011).
Harbor porpoise (Phocoena Gulf of Maine/Bay of --; N 95,543 (0.31; * 45,089 851 217 Common.
phocoena). Fundy. 74,034; 2011). (0.12)
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Baleen whales (Mysticeti)
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North Atlantic right whale W. North Atlantic.... E; Y 428 (0; 418; n/a)... * 535 (0.45) 0.8 6.85 Occur seasonally.
(Eubalaena glacialis).
Humpback whale \7\ (Megaptera Gulf of Maine........ --; N 1,396 (0; 1,380; n/ * 1,637 (0.07) 22 12.15 Common year round.
novaeangliae). a).
[[Page 7930]]
Fin whale \6\ (Balaenoptera W. North Atlantic.... E; Y 7,418 (0.25; 6,025; 4,633 (0.08) 12 2.35 Year round in
physalus). n/a). continental shelf
and slope waters.
Sei whale (Balaenoptera borealis). Nova Scotia.......... E; Y 6,292 (1.015; 3,098; * 717 (0.30) 6.2 1.0 Year round in
n/a). continental shelf
and slope waters.
Minke whale \6\ (Balaenoptera Canadian East Coast.. --; N 24,202 (0.3; 18,902; * 2,112 (0.05) 8.0 7.0 Year round in
acutorostrata). n/a). continental shelf
and slope waters.
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Earless seals (Phocidae)
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Gray seal \8\ (Halichoerus grypus) W. North Atlantic.... --; N 27,131 (0.19; .............. 1,389 5,410 Common.
23,158; n/a).
Harbor seal (Phoca vitulina)...... W. North Atlantic.... --; N 75,834 (0.15; .............. 2,006 350 Common.
66,884; 2012).
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\1\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR (see
footnote 3) or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ Stock abundance as reported in NMFS marine mammal stock assessment reports (SAR) except where otherwise noted. SARs available online at:
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments. CV is coefficient of variation; Nmin is the minimum estimate
of stock abundance. In some cases, CV is not applicable. For certain stocks, abundance estimates are actual counts of animals and there is no
associated CV. The most recent abundance survey that is reflected in the abundance estimate is presented; there may be more recent surveys that have
not yet been incorporated into the estimate. All values presented here are from the 2019 draft Atlantic SARs (Hayes et al., 2019).
\3\ This information represents species- or guild-specific abundance predicted by recent habitat-based cetacean density models (Roberts et al., 2016,
2017, 2018). These models provide the best available scientific information regarding predicted density patterns of cetaceans in the U.S. Atlantic
Ocean, and we provide the corresponding abundance predictions as a point of reference. Total abundance estimates were produced by computing the mean
density of all pixels in the modeled area and multiplying by its area. For those species marked with an asterisk, the available information supported
development of either two or four seasonal models; each model has an associated abundance prediction. Here, we report the maximum predicted abundance.
\4\ Potential biological removal, defined by the MMPA as the maximum number of animals, not including natural mortalities, that may be removed from a
marine mammal stock while allowing that stock to reach or maintain its optimum sustainable population size (OSP). Annual M/SI, found in NMFS' SARs,
represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial fisheries, subsistence hunting, ship
strike). Annual M/SI values often cannot be determined precisely and is in some cases presented as a minimum value. All M/SI values are as presented
in the draft 2019 SARs (Hayes et al., 2019).
\5\ Abundance estimates are in some cases reported for a guild or group of species when those species are difficult to differentiate at sea. Similarly,
the habitat-based cetacean density models produced by Roberts et al. (2016, 2017, 2018) are based in part on available observational data which, in
some cases, is limited to genus or guild in terms of taxonomic definition. Roberts et al. (2016, 2017, 2018) produced density models to genus level
for Globicephala spp. and produced a density model for bottlenose dolphins that does not differentiate between offshore and coastal stocks.
\6\ Abundance as reported in the 2007 Canadian Trans-North Atlantic Sighting Survey (TNASS), which provided full coverage of the Atlantic Canadian coast
(Lawson and Gosselin, 2009). Abundance estimates from TNASS were corrected for perception and availability bias, when possible. In general, where the
TNASS survey effort provided superior coverage of a stock's range (as compared with NOAA shipboard survey effort), the resulting abundance estimate is
considered more accurate than the current NMFS abundance estimate (derived from survey effort with inferior coverage of the stock range). NMFS stock
abundance estimate for the common dolphin is 70,184. NMFS stock abundance estimate for the fin whale is 1,618. NMFS stock abundance estimate for the
minke whale is 2,591.
\7\ 2018 U.S. Atlantic draft SAR for the Gulf of Maine feeding population lists a current abundance estimate of 896 individuals. However, we note that
the estimate is defined on the basis of feeding location alone (i.e., Gulf of Maine) and is therefore likely an underestimate.
\8\ NMFS stock abundance estimate applies to U.S. population only, actual stock abundance is approximately 505,000.
Four marine mammal species that are listed under the Endangered
Species Act (ESA) may be present in the survey area and are included in
the take request: The North Atlantic right, fin, sei, and sperm whale.
Below is a description of the species that have the highest
likelihood of occurring in the project area and are thus expected to
potentially be taken by the proposed activities. For the majority of
species potentially present in the specific geographic region, NMFS has
designated only a single generic stock (e.g., ``western North
Atlantic'') for management purposes. This includes the ``Canadian east
coast'' stock of minke whales, which includes all minke whales found in
U.S. waters is also a generic stock for management purposes. For
humpback whales, NMFS defines stocks on the basis of feeding locations,
i.e., Gulf of Maine. However, references to humpback whales in this
document refer to any individuals of the species that are found in the
specific geographic region.
North Atlantic Right Whale
The North Atlantic right whale ranges from calving grounds in the
southeastern United States to feeding grounds in New England waters and
into Canadian waters (Hayes et al., 2018). Surveys have demonstrated
the existence of seven areas where North Atlantic right whales
congregate seasonally, including north and east of the proposed project
area in Georges Bank, off Cape Cod, and in Massachusetts Bay (Hayes et
al., 2018). In the late fall months (e.g. October), right whales are
generally thought to depart from the feeding grounds in the North
Atlantic and move south to their calving grounds off Georgia and
Florida. However, recent research indicates our understanding of their
movement patterns remains incomplete (Davis et al. 2017). A review of
passive acoustic monitoring data from 2004 to 2014 throughout the
western North Atlantic demonstrated nearly continuous year-round right
whale presence across their entire habitat range (for at least some
individuals), including in locations previously thought of as migratory
corridors, suggesting that not all of the population undergoes a
consistent annual migration (Davis et al. 2017).
The western North Atlantic population demonstrated overall growth
of 2.8 percent per year between 1990 to 2010, despite a decline in 1993
and no growth between 1997 and 2000 (Pace et al. 2017). However, since
2010 the population has been in decline, with a 99.99 percent
probability of a decline of just under 1 percent per year (Pace et al.
2017). Between 1990 and 2015, calving rates varied substantially, with
low calving rates coinciding with all three periods of decline or no
growth (Pace et al. 2017). On average, North Atlantic right whale
calving rates are estimated to be roughly half that of southern right
whales (Eubalaena australis) (Pace et al.
[[Page 7931]]
2017), which are increasing in abundance (NMFS 2015). In 2018, no new
North Atlantic right whale calves were documented in their calving
grounds; this represented the first time since annual NOAA aerial
surveys began in 1989 that no new right whale calves were observed.
Seven right whale calves were documented in 2019. The current best
estimate of population abundance for the species is 409 individuals,
based on data as of September 4, 2019 (Pettis et al., 2019).
Elevated North Atlantic right whale mortalities have occurred since
June 7, 2017 along the U.S. and Canadian coast. As of February, 2020, a
total of 30 confirmed dead stranded whales (21 in Canada; 9 in the
United States) have been documented. This event has been declared an
Unusual Mortality Event (UME), with human interactions, including
entanglement in fixed fishing gear and vessel strikes, implicated in at
least 15 of the mortalities thus far. More information is available
online at: www.fisheries.noaa.gov/national/marine-life-distress/2017-2019-north-atlantic-right-whale-unusual-mortality-event.
Any right whales in the vicinity of the survey areas are expected
to be transient, most likely migrating through the area. The proposed
survey areas are part of a biologically important migratory area for
North Atlantic right whales; this important migratory area is comprised
of the waters of the continental shelf offshore the East Coast of the
United States and extends from Florida through Massachusetts. NMFS'
regulations at 50 CFR part 224.105 designated nearshore waters of the
Mid-Atlantic Bight as Mid-Atlantic U.S. Seasonal Management Areas (SMA)
for right whales in 2008. SMAs were developed to reduce the threat of
collisions between ships and right whales around their migratory route
and calving grounds. Within SMAs, the regulations require a mandatory
vessel speed (less than 10 kn) for all vessels greater than 65 ft. A
portion of one SMA overlaps spatially with the northern section of the
proposed survey area. This SMA, which is associated with port of New
York/New Jersey, is active from November 1 through April 30 of each
year. All Atlantic Shores survey vessels, regardless of length, would
be required to adhere to a 10 kn vessel speed restriction when
operating within this SMA (when the SMA is active from November 1
through April 30). In addition, all Atlantic Shores survey vessels,
regardless of length, would be required to adhere to a 10-kn vessel
speed restriction when operating in any Dynamic Management Area (DMA)
declared by NMFS.
Humpback Whale
Humpback whales are found worldwide in all oceans. Humpback whales
were listed as endangered under the Endangered Species Conservation Act
(ESCA) in June 1970. In 1973, the ESA replaced the ESCA, and humpbacks
continued to be listed as endangered. On September 8, 2016, NMFS
divided the species into 14 distinct population segments (DPS), removed
the current species-level listing, and in its place listed four DPSs as
endangered and one DPS as threatened (81 FR 62259; September 8, 2016).
The remaining nine DPSs were not listed. The West Indies DPS, which is
not listed under the ESA, is the only DPS of humpback whale that is
expected to occur in the project area.
Humpback whales utilize the mid-Atlantic as a migration pathway
between calving/mating grounds to the south and feeding grounds in the
north (Waring et al. 2007). A key question with regard to humpback
whales off the mid-Atlantic states is their stock identity. Using fluke
photographs of living and dead whales observed in the region, Barco et
al. (2002) reported that 43 percent of 21 live whales matched to the
Gulf of Maine, 19 percent to Newfoundland, and 4.8 percent to the Gulf
of St Lawrence, while 31.6 percent of 19 dead humpbacks were known Gulf
of Maine whales. Although the population composition of the mid-
Atlantic is apparently dominated by Gulf of Maine whales, lack of
photographic effort in Newfoundland makes it likely that the observed
match rates under-represent the true presence of Canadian whales in the
region (Waring et al., 2016). Barco et al. (2002) suggested that the
mid-Atlantic region primarily represents a supplemental winter feeding
ground used by humpbacks.
Since January 2016, elevated humpback whale mortalities have
occurred along the Atlantic coast from Maine to Florida. As of
February, 2020, partial or full necropsy examinations have been
conducted on approximately half of the 111 known cases. Of the whales
examined, about 50 percent had evidence of human interaction, either
ship strike or entanglement. While a portion of the whales have shown
evidence of pre-mortem vessel strike, this finding is not consistent
across all whales examined and more research is needed. NOAA is
consulting with researchers that are conducting studies on the humpback
whale populations, and these efforts may provide information on changes
in whale distribution and habitat use that could provide additional
insight into how these vessel interactions occurred. Three previous
UMEs involving humpback whales have occurred since 2000, in 2003, 2005,
and 2006. More information is available at: www.fisheries.noaa.gov/national/marine-life-distress/2016-2019-humpback-whale-unusual-mortality-event-along-atlantic-coast.
Fin Whale
Fin whales are common in waters of the U. S. Atlantic Exclusive
Economic Zone (EEZ), principally from Cape Hatteras northward (Waring
et al., 2016). Fin whales are present north of 35-degree latitude in
every season and are broadly distributed throughout the western North
Atlantic for most of the year (Waring et al., 2016). They are typically
found in small groups of up to five individuals (Brueggeman et al.,
1987). The main threats to fin whales are fishery interactions and
vessel collisions (Waring et al., 2016).
Sei Whale
The Nova Scotia stock of sei whales can be found in deeper waters
of the continental shelf edge waters of the northeastern U.S. and
northeastward to south of Newfoundland. The southern portion of the
stock's range during spring and summer includes the Gulf of Maine and
Georges Bank. Spring is the period of greatest abundance in U.S.
waters, with sightings concentrated along the eastern margin of Georges
Bank and into the Northeast Channel area, and along the southwestern
edge of Georges Bank in the area of Hydrographer Canyon (Waring et al.,
2015). Sei whales occur in shallower waters to feed. Sei whales are
listed as engendered under the ESA, and the Nova Scotia stock is
considered strategic and depleted under the MMPA. The main threats to
this stock are interactions with fisheries and vessel collisions.
Minke Whale
Minke whales can be found in temperate, tropical, and high-latitude
waters. The Canadian East Coast stock can be found in the area from the
western half of the Davis Strait (45[deg]W) to the Gulf of Mexico
(Waring et al., 2016). This species generally occupies waters less than
100 m deep on the continental shelf. There appears to be a strong
seasonal component to minke whale distribution in the survey areas, in
which spring to fall are times of relatively widespread and common
occurrence while during winter the
[[Page 7932]]
species appears to be largely absent (Waring et al., 2016).
Since January 2017, elevated minke whale mortalities have occurred
along the Atlantic coast from Maine through South Carolina. This event
has been declared a UME. As of February, 2020 partial or full necropsy
examinations have been conducted on approximately 60 percent of the 79
known cases. Preliminary findings in several of the whales have shown
evidence of human interactions or infectious disease, but these
findings are not consistent across all of the whales examined, so more
research is needed. More information is available at:
www.fisheries.noaa.gov/national/marine-life-distress/2017-2019-minke-whale-unusual-mortality-event-along-atlantic-coast.
Sperm Whale
The distribution of the sperm whale in the U.S. EEZ occurs on the
continental shelf edge, over the continental slope, and into mid-ocean
regions (Waring et al., 2014). The basic social unit of the sperm whale
appears to be the mixed school of adult females plus their calves and
some juveniles of both sexes, normally numbering 20-40 animals in all.
There is evidence that some social bonds persist for many years
(Christal et al., 1998). This species forms stable social groups, site
fidelity, and latitudinal range limitations in groups of females and
juveniles (Whitehead, 2002). In summer, the distribution of sperm
whales includes the area east and north of Georges Bank and into the
Northeast Channel region, as well as the continental shelf (inshore of
the 100-m isobath) south of New England. In the fall, sperm whale
occurrence south of New England on the continental shelf is at its
highest level, and there remains a continental shelf edge occurrence in
the mid-Atlantic bight. In winter, sperm whales are concentrated east
and northeast of Cape Hatteras.
Long-finned Pilot Whale
Long-finned pilot whales are found from North Carolina and north to
Iceland, Greenland and the Barents Sea (Waring et al., 2016). In U.S.
Atlantic waters the species is distributed principally along the
continental shelf edge off the northeastern U.S. coast in winter and
early spring and in late spring, pilot whales move onto Georges Bank
and into the Gulf of Maine and more northern waters and remain in these
areas through late autumn (Waring et al., 2016). Long-finned pilot
whales are not listed under the ESA. The Western North Atlantic stock
is considered strategic under the MMPA.
Atlantic White-sided Dolphin
White-sided dolphins are found in temperate and sub-polar waters of
the North Atlantic, primarily in continental shelf waters to the 100-m
depth contour from central West Greenland to North Carolina (Waring et
al., 2016). The Gulf of Maine stock is most common in continental shelf
waters from Hudson Canyon to Georges Bank, and in the Gulf of Maine and
lower Bay of Fundy. Sighting data indicate seasonal shifts in
distribution (Northridge et al., 1997). During January to May, low
numbers of white-sided dolphins are found from Georges Bank to Jeffreys
Ledge (off New Hampshire), with even lower numbers south of Georges
Bank, as documented by a few strandings collected on beaches of
Virginia to South Carolina. From June through September, large numbers
of white-sided dolphins are found from Georges Bank to the lower Bay of
Fundy. From October to December, white-sided dolphins occur at
intermediate densities from southern Georges Bank to southern Gulf of
Maine (Payne and Heinemann 1990). Sightings south of Georges Bank,
particularly around Hudson Canyon, occur year round but at low
densities.
Atlantic Spotted Dolphin
Atlantic spotted dolphins are found in tropical and warm temperate
waters ranging from southern New England, south to Gulf of Mexico and
the Caribbean to Venezuela (Waring et al., 2014). This stock regularly
occurs in continental shelf waters south of Cape Hatteras and in
continental shelf edge and continental slope waters north of this
region (Waring et al., 2014). There are two forms of this species, with
the larger ecotype inhabiting the continental shelf and is usually
found inside or near the 200 m isobaths (Waring et al., 2014).
Common Dolphin
The short-beaked common dolphin is found world-wide in temperate to
subtropical seas. In the North Atlantic, short-beaked common dolphins
are commonly found over the continental shelf between the 100-m and
2,000-m isobaths and over prominent underwater topography and east to
the mid-Atlantic Ridge (Waring et al., 2016).
Bottlenose Dolphin
There are two distinct bottlenose dolphin morphotypes in the
western North Atlantic: The coastal and offshore forms (Waring et al.,
2016). The offshore form is distributed primarily along the outer
continental shelf and continental slope in the Northwest Atlantic Ocean
from Georges Bank to the Florida Keys. The coastal morphotype is
morphologically and genetically distinct from the larger, more robust
morphotype that occupies habitats further offshore. Spatial
distribution data, tag-telemetry studies, photo-ID studies and genetic
studies demonstrate the existence of a distinct Northern Migratory
stock of coastal bottlenose dolphins (Waring et al., 2014). During
summer months (July-August), this stock occupies coastal waters from
the shoreline to approximately the 25 m isobath between the Chesapeake
Bay mouth and Long Island, New York; during winter months (January-
March), the stock occupies coastal waters from Cape Lookout, North
Carolina, to the North Carolina/Virginia border (Waring et al., 2014).
The Western North Atlantic northern migratory coastal stock and the
Western North Atlantic offshore stock may be encountered by the
proposed survey.
Harbor Porpoise
In the Lease Area, only the Gulf of Maine/Bay of Fundy stock may be
present. This stock is found in U.S. and Canadian Atlantic waters and
is concentrated in the northern Gulf of Maine and southern Bay of Fundy
region, generally in waters less than 150 m deep (Waring et al., 2016).
They are seen from the coastline to deep waters (>1800 m; Westgate et
al. 1998), although the majority of the population is found over the
continental shelf (Waring et al., 2016). The main threat to the species
is interactions with fisheries, with documented take in the U.S.
northeast sink gillnet, mid-Atlantic gillnet, and northeast bottom
trawl fisheries and in the Canadian herring weir fisheries (Waring et
al., 2016).
Harbor Seal
The harbor seal is found in all nearshore waters of the North
Atlantic and North Pacific Oceans and adjoining seas above about
30[deg]N (Burns, 2009). In the western North Atlantic, harbor seals are
distributed from the eastern Canadian Arctic and Greenland south to
southern New England and New York, and occasionally to the Carolinas
(Waring et al., 2016). Haulout and pupping sites are located off
Manomet, MA and the Isles of Shoals, ME, but generally do not occur in
areas in southern New England (Waring et al., 2016).
Since July 2018, elevated numbers of harbor seal and gray seal
mortalities have occurred across Maine, New Hampshire and
Massachusetts. This event has been declared a UME. Additionally,
stranded seals have shown clinical signs as far south as Virginia,
although not in elevated
[[Page 7933]]
numbers, therefore the UME investigation now encompasses all seal
strandings from Maine to Virginia. Lastly, ice seals (harp and hooded
seals) have also started stranding with clinical signs, again not in
elevated numbers, and those two seal species have also been added to
the UME investigation. As of February, 2020 a total of 3,050 reported
strandings (of all species) had occurred, including 94 strandings
reported in New Jersey. Full or partial necropsy examinations have been
conducted on some of the seals and samples have been collected for
testing. Based on tests conducted thus far, the main pathogen found in
the seals is phocine distemper virus. NMFS is performing additional
testing to identify any other factors that may be involved in this UME.
Information on this UME is available online at: www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2019-pinniped-unusual-mortality-event-along.
Gray Seal
There are three major populations of gray seals found in the world;
eastern Canada (western North Atlantic stock), northwestern Europe and
the Baltic Sea. Gray seals in the survey area belong to the western
North Atlantic stock. The range for this stock is thought to be from
New Jersey to Labrador. Current population trends show that gray seal
abundance is likely increasing in the U.S. Atlantic EEZ (Waring et al.,
2016). Although the rate of increase is unknown, surveys conducted
since their arrival in the 1980s indicate a steady increase in
abundance in both Maine and Massachusetts (Waring et al., 2016). It is
believed that recolonization by Canadian gray seals is the source of
the U.S. population (Waring et al., 2016).
As described above, elevated seal mortalities, including gray
seals, have occurred from Maine to Virginia since July 2018. This event
has been declared a UME, with phocine distemper virus identified as the
main pathogen found in the seals. NMFS is performing additional testing
to identify any other factors that may be involved in this UME.
Information on this UME is available online at: www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2019-pinniped-unusual-mortality-event-along.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Current data indicate that not all marine
mammal species have equal hearing capabilities (e.g., Richardson et
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect
this, Southall et al. (2007) recommended that marine mammals be divided
into functional hearing groups based on directly measured or estimated
hearing ranges on the basis of available behavioral response data,
audiograms derived using auditory evoked potential techniques,
anatomical modeling, and other data. Note that no direct measurements
of hearing ability have been successfully completed for mysticetes
(i.e., low-frequency cetaceans). Subsequently, NMFS (2016) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65
decibel (dB) threshold from the normalized composite audiograms, with
the exception for lower limits for low-frequency cetaceans where the
lower bound was deemed to be biologically implausible and the lower
bound from Southall et al. (2007) retained. The functional groups and
the associated frequencies are indicated below (note that these
frequency ranges correspond to the range for the composite group, with
the entire range not necessarily reflecting the capabilities of every
species within that group):
Low-frequency cetaceans (mysticetes): Generalized hearing
is estimated to occur between approximately 7 Hertz (Hz) and 35
kilohertz (kHz);
Mid-frequency cetaceans (larger toothed whales, beaked
whales, and most delphinids): Generalized hearing is estimated to occur
between approximately 150 Hz and 160 kHz;
High-frequency cetaceans (porpoises, river dolphins, and
members of the genera Kogia and Cephalorhynchus; including two members
of the genus Lagenorhynchus, on the basis of recent echolocation data
and genetic data): Generalized hearing is estimated to occur between
approximately 275 Hz and 160 kHz; and
Pinnipeds in water; Phocidae (true seals): Generalized
hearing is estimated to occur between approximately 50 Hz to 86 kH.
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2016) for a review of available information.
Fourteen marine mammal species (twelve cetacean and two pinniped (both
phocid species) have the reasonable potential to co-occur with the
proposed survey activities (see Table 3). Of the cetacean species that
may be present, five are classified as low-frequency cetaceans (i.e.,
all mysticete species), six 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
Habitat
This section includes a summary and discussion of the ways that
components of the specified activity may impact marine mammals and
their habitat. The Estimated Take section later in this document
includes a quantitative analysis of the number of individuals that are
expected to be taken by this activity. The Negligible Impact Analysis
and Determination section considers the content of this section, the
Estimated Take section, and the Proposed Mitigation section, to draw
conclusions regarding the likely impacts of these activities on the
reproductive success or survivorship of individuals and how those
impacts on individuals are likely to impact marine mammal species or
stocks.
Background on Sound
Sound is a physical phenomenon consisting of minute vibrations that
travel through a medium, such as air or water, and is generally
characterized by several variables. Frequency describes the sound's
pitch and is measured in Hz or kHz, while sound level describes the
sound's intensity and is measured in dB. Sound level increases or
decreases exponentially with each dB of change. The logarithmic nature
of the scale means that each 10-dB increase is a 10-fold increase in
acoustic power (and a 20-dB increase is then a 100-fold increase in
power). A 10-fold increase in acoustic power does not mean that the
sound is perceived as being 10 times louder, however. Sound levels are
compared to a reference sound pressure (micro-Pascal) to identify the
medium. For air and water, these reference pressures are ``re: 20 micro
Pascals ([micro]Pa)'' and ``re: 1 [micro]Pa,'' respectively. Root mean
square (RMS) is the quadratic mean sound pressure over the duration of
an impulse. RMS is
[[Page 7934]]
calculated by squaring all of the sound amplitudes, averaging the
squares, and then taking the square root of the average (Urick 1975).
RMS accounts for both positive and negative values; squaring the
pressures makes all values positive so that they may be accounted for
in the summation of pressure levels. This measurement is often used in
the context of discussing behavioral effects, in part because
behavioral effects, which often result from auditory cues, may be
better expressed through averaged units rather than by peak pressures.
When sound travels (propagates) from its source, its loudness
decreases as the distance traveled by the sound increases. Thus, the
loudness of a sound at its source is higher than the loudness of that
same sound one km away. Acousticians often refer to the loudness of a
sound at its source (typically referenced to one meter from the source)
as the source level and the loudness of sound elsewhere as the received
level (i.e., typically the receiver). For example, a humpback whale 3
km from a device that has a source level of 230 dB may only be exposed
to sound that is 160 dB loud, depending on how the sound travels
through water (e.g., spherical spreading (6 dB reduction with doubling
of distance) was used in this example). As a result, it is important to
understand the difference between source levels and received levels
when discussing the loudness of sound in the ocean or its impacts on
the marine environment.
As sound travels from a source, its propagation in water is
influenced by various physical characteristics, including water
temperature, depth, salinity, and surface and bottom properties that
cause refraction, reflection, absorption, and scattering of sound
waves. Oceans are not homogeneous and the contribution of each of these
individual factors is extremely complex and interrelated. The physical
characteristics that determine the sound's speed through the water will
change with depth, season, geographic location, and with time of day
(as a result, in actual active sonar operations, crews will measure
oceanic conditions, such as sea water temperature and depth, to
calibrate models that determine the path the sonar signal will take as
it travels through the ocean and how strong the sound signal will be at
a given range along a particular transmission path). As sound travels
through the ocean, the intensity associated with the wavefront
diminishes, or attenuates. This decrease in intensity is referred to as
propagation loss, also commonly called transmission loss.
Acoustic Impacts
Geophysical surveys may temporarily impact marine mammals in the
area due to elevated in-water sound levels. Marine mammals are
continually exposed to many sources of sound. Naturally occurring
sounds such as lightning, rain, sub-sea earthquakes, and biological
sounds (e.g., snapping shrimp, whale songs) are widespread throughout
the world's oceans. Marine mammals produce sounds in various contexts
and use sound for various biological functions including, but not
limited to: (1) Social interactions; (2) foraging; (3) orientation; and
(4) predator detection. Interference with producing or receiving these
sounds may result in adverse impacts. Audible distance, or received
levels of sound depend on the nature of the sound source, ambient noise
conditions, and the sensitivity of the receptor to the sound
(Richardson et al., 1995). Type and significance of marine mammal
reactions to sound are likely dependent on a variety of factors
including, but not limited to, (1) the behavioral state of the animal
(e.g., feeding, traveling, etc.); (2) frequency of the sound; (3)
distance between the animal and the source; and (4) the level of the
sound relative to ambient conditions (Southall et al., 2007).
When considering the influence of various kinds of sound on the
marine environment, it is necessary to understand that different kinds
of marine life are sensitive to different frequencies of sound. Current
data indicate that not all marine mammal species have equal hearing
capabilities (Richardson et al., 1995; Wartzok and Ketten, 1999; Au and
Hastings, 2008).
Animals are less sensitive to sounds at the outer edges of their
functional hearing range and are more sensitive to a range of
frequencies within the middle of their functional hearing range.
Hearing Impairment
Marine mammals may experience temporary or permanent hearing
impairment when exposed to loud sounds. Hearing impairment is
classified by temporary threshold shift (TTS) and permanent threshold
shift (PTS). PTS is considered auditory injury (Southall et al., 2007)
and occurs in a specific frequency range and amount. Irreparable damage
to the inner or outer cochlear hair cells may cause PTS; however, other
mechanisms are also involved, such as exceeding the elastic limits of
certain tissues and membranes in the middle and inner ears and
resultant changes in the chemical composition of the inner ear fluids
(Southall et al., 2007). There are no empirical data for onset of PTS
in any marine mammal; therefore, PTS-onset must be estimated from TTS-
onset measurements and from the rate of TTS growth with increasing
exposure levels above the level eliciting TTS-onset. PTS is presumed to
be likely if the hearing threshold is reduced by >=40 dB (that is, 40
dB of TTS).
Temporary Threshold Shift (TTS)
TTS is the mildest form of hearing impairment that can occur during
exposure to a loud sound (Kryter 1985). While experiencing TTS, the
hearing threshold rises and a sound must be stronger in order to be
heard. At least in terrestrial mammals, TTS can last from minutes or
hours to (in cases of strong TTS) days, can be limited to a particular
frequency range, and can occur to varying degrees (i.e., a loss of a
certain number of dBs of sensitivity). For sound exposures at or
somewhat above the TTS threshold, hearing sensitivity in both
terrestrial and marine mammals recovers rapidly after exposure to the
noise ends.
Marine mammal hearing plays a critical role in communication with
conspecifics and in interpretation of environmental cues for purposes
such as predator avoidance and prey capture. Depending on the degree
(elevation of threshold in dB), duration (i.e., recovery time), and
frequency range of TTS and the context in which it is experienced, TTS
can have effects on marine mammals ranging from discountable to
serious. For example, a marine mammal may be able to readily compensate
for a brief, relatively small amount of TTS in a non-critical frequency
range that takes place during a time when the animals is traveling
through the open ocean, where ambient noise is lower and there are not
as many competing sounds present. Alternatively, a larger amount and
longer duration of TTS sustained during a time when communication is
critical for successful mother/calf interactions could have more
serious impacts if it were in the same frequency band as the necessary
vocalizations and of a severity that it impeded communication. The fact
that animals exposed to levels and durations of sound that would be
expected to result in this physiological response would also be
expected to have behavioral responses of a comparatively more severe or
sustained nature is also notable and potentially of more importance
than the simple existence of a TTS.
[[Page 7935]]
Currently, TTS data only exist for four species of cetaceans
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor
porpoise, and Yangtze finless porpoise (Neophocaena phocaenoides)) and
three species of pinnipeds (northern elephant seal (Mirounga
angustirostris), harbor seal, and California sea lion (Zalophus
californianus)) exposed to a limited number of sound sources (i.e.,
mostly tones and octave-band noise) in laboratory settings (e.g.,
Finneran et al., 2002 and 2010; Nachtigall et al., 2004; Kastak et al.,
2005; Lucke et al., 2009; Mooney et al., 2009; Popov et al., 2011;
Finneran and Schlundt, 2010). In general, harbor seals (Kastak et al.,
2005; Kastelein et al., 2012a) and harbor porpoises (Lucke et al.,
2009; Kastelein et al., 2012b) have a lower TTS onset than other
measured pinniped or cetacean species. However, even for these animals,
which are better able to hear higher frequencies and may be more
sensitive to higher frequencies, exposures on the order of
approximately 170 dB RMS or higher for brief transient signals are
likely required for even temporary (recoverable) changes in hearing
sensitivity that would likely not be categorized as physiologically
damaging (Lucke et al., 2009). Additionally, the existing marine mammal
TTS data come from a limited number of individuals within these
species. There are no data available on noise-induced hearing loss for
mysticetes. For summaries of data on TTS in marine mammals or for
further discussion of TTS onset thresholds, please see Finneran (2015).
Scientific literature highlights the inherent complexity of
predicting TTS onset in marine mammals, as well as the importance of
considering exposure duration when assessing potential impacts (Mooney
et al., 2009a, 2009b; Kastak et al., 2007). Generally, with sound
exposures of equal energy, quieter sounds (lower sound pressure levels
(SPL)) of longer duration were found to induce TTS onset more than
louder sounds (higher SPL) of shorter duration (more similar to sub-
bottom profilers). For intermittent sounds, less threshold shift will
occur than from a continuous exposure with the same energy (some
recovery will occur between intermittent exposures) (Kryter et al.,
1966; Ward 1997). For sound exposures at or somewhat above the TTS-
onset threshold, hearing sensitivity recovers rapidly after exposure to
the sound ends; intermittent exposures recover faster in comparison
with continuous exposures of the same duration (Finneran et al., 2010).
NMFS considers TTS as Level B harassment that is mediated by
physiological effects on the auditory system.
Animals in the Lease Area during the HRG survey are unlikely to
incur TTS hearing impairment due to the characteristics of the sound
sources, which include low source levels (208 to 221 dB re 1 [micro]Pa-
m) and generally very short pulses and duration of the sound. Even for
high-frequency cetacean species (e.g., harbor porpoises), which may
have increased sensitivity to TTS (Lucke et al., 2009; Kastelein et
al., 2012b), individuals would have to make a very close approach and
also remain very close to vessels operating these sources in order to
receive multiple exposures at relatively high levels, as would be
necessary to cause TTS. Intermittent exposures--as would occur due to
the brief, transient signals produced by these sources--require a
higher cumulative SEL to induce TTS than would continuous exposures of
the same duration (i.e., intermittent exposure results in lower levels
of TTS) (Mooney et al., 2009a; Finneran et al., 2010). Moreover, most
marine mammals would more likely avoid a loud sound source rather than
swim in such close proximity as to result in TTS. Kremser et al. (2005)
noted that the probability of a cetacean swimming through the area of
exposure when a sub-bottom profiler emits a pulse is small--because if
the animal was in the area, it would have to pass the transducer at
close range in order to be subjected to sound levels that could cause
TTS and would likely exhibit avoidance behavior to the area near the
transducer rather than swim through at such a close range. Further, the
restricted beam shape of the majority of the geophysical survey
equipment planned for use (Table 1) makes it unlikely that an animal
would be exposed more than briefly during the passage of the vessel.
Masking
Masking is the obscuring of sounds of interest to an animal by
other sounds, typically at similar frequencies. Marine mammals are
highly dependent on sound, and their ability to recognize sound signals
amid other sound is important in communication and detection of both
predators and prey (Tyack 2000). Background ambient sound may interfere
with or mask the ability of an animal to detect a sound signal even
when that signal is above its absolute hearing threshold. Even in the
absence of anthropogenic sound, the marine environment is often loud.
Natural ambient sound includes contributions from wind, waves,
precipitation, other animals, and (at frequencies above 30 kHz) thermal
sound resulting from molecular agitation (Richardson et al., 1995).
Background sound may also include anthropogenic sound, and masking
of natural sounds can result when human activities produce high levels
of background sound. Conversely, if the background level of underwater
sound is high (e.g., on a day with strong wind and high waves), an
anthropogenic sound source would not be detectable as far away as would
be possible under quieter conditions and would itself be masked.
Ambient sound is highly variable on continental shelves (Myrberg 1978;
Desharnais et al., 1999). This results in a high degree of variability
in the range at which marine mammals can detect anthropogenic sounds.
Although masking is a phenomenon which may occur naturally, the
introduction of loud anthropogenic sounds into the marine environment
at frequencies important to marine mammals increases the severity and
frequency of occurrence of masking. For example, if a baleen whale is
exposed to continuous low-frequency sound from an industrial source,
this would reduce the size of the area around that whale within which
it can hear the calls of another whale. The components of background
noise that are similar in frequency to the signal in question primarily
determine the degree of masking of that signal. In general, little is
known about the degree to which marine mammals rely upon detection of
sounds from conspecifics, predators, prey, or other natural sources. In
the absence of specific information about the importance of detecting
these natural sounds, it is not possible to predict the impact of
masking on marine mammals (Richardson et al., 1995). In general,
masking effects are expected to be less severe when sounds are
transient than when they are continuous. Masking is typically of
greater concern for those marine mammals that utilize low-frequency
communications, such as baleen whales, because of how far low-frequency
sounds propagate.
Marine mammal communications would not likely be masked appreciably
by the sub-bottom profiler signals given the directionality of the
signals (for most geophysical survey equipment types planned for use
(Table 1)) and the brief period when an individual mammal is likely to
be within its beam.
Non-Auditory Physical Effects (Stress)
Classic stress responses begin when an animal's central nervous
system perceives a potential threat to its homeostasis. That perception
triggers
[[Page 7936]]
stress responses regardless of whether a stimulus actually threatens
the animal; the mere perception of a threat is sufficient to trigger a
stress response (Moberg 2000; Seyle 1950). Once an animal's central
nervous system perceives a threat, it mounts a biological response or
defense that consists of a combination of the four general biological
defense responses: behavioral responses, autonomic nervous system
responses, neuroendocrine responses, or immune responses.
In the case of many stressors, an animal's first and sometimes most
economical (in terms of biotic costs) response is behavioral avoidance
of the potential stressor or avoidance of continued exposure to a
stressor. An animal's second line of defense to stressors involves the
sympathetic part of the autonomic nervous system and the classical
``fight or flight'' response which includes the cardiovascular system,
the gastrointestinal system, the exocrine glands, and the adrenal
medulla to produce changes in heart rate, blood pressure, and
gastrointestinal activity that humans commonly associate with
``stress.'' These responses have a relatively short duration and may or
may not have significant long-term effect on an animal's welfare.
An animal's third line of defense to stressors involves its
neuroendocrine systems; the system that has received the most study has
been the hypothalamus-pituitary-adrenal system (also known as the HPA
axis in mammals). Unlike stress responses associated with the autonomic
nervous system, virtually all neuro-endocrine functions that are
affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been
implicated in failed reproduction (Moberg 1987; Rivier 1995), altered
metabolism (Elasser et al., 2000), reduced immune competence (Blecha
2000), and behavioral disturbance. Increases in the circulation of
glucocorticosteroids (cortisol, corticosterone, and aldosterone in
marine mammals; see Romano et al., 2004) have been equated with stress
for many years.
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and distress is the biotic cost
of the response. During a stress response, an animal uses glycogen
stores that can be quickly replenished once the stress is alleviated.
In such circumstances, the cost of the stress response would not pose a
risk to the animal's welfare. However, when an animal does not have
sufficient energy reserves to satisfy the energetic costs of a stress
response, energy resources must be diverted from other biotic function,
which impairs those functions that experience the diversion. For
example, when mounting a stress response diverts energy away from
growth in young animals, those animals may experience stunted growth.
When mounting a stress response diverts energy from a fetus, an
animal's reproductive success and its fitness will suffer. In these
cases, the animals will have entered a pre-pathological or pathological
state which is called ``distress'' (Seyle 1950) or ``allostatic
loading'' (McEwen and Wingfield 2003). This pathological state will
last until the animal replenishes its biotic reserves sufficient to
restore normal function. Note that these examples involved a long-term
(days or weeks) stress response exposure to stimuli.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses have also been documented
fairly well through controlled experiments; because this physiology
exists in every vertebrate that has been studied, it is not surprising
that stress responses and their costs have been documented in both
laboratory and free-living animals (for examples see, Holberton et al.,
1996; Hood et al., 1998; Jessop et al., 2003; Krausman et al., 2004;
Lankford et al., 2005; Reneerkens et al., 2002; Thompson and Hamer,
2000). Information has also been collected on the physiological
responses of marine mammals to exposure to anthropogenic sounds (Fair
and Becker 2000; Romano et al., 2002). For example, Rolland et al.
(2012) found that noise reduction from reduced ship traffic in the Bay
of Fundy was associated with decreased stress in North Atlantic right
whales.
Studies of other marine animals and terrestrial animals would also
lead us to expect some marine mammals to experience physiological
stress responses and, perhaps, physiological responses that would be
classified as ``distress'' upon exposure to high frequency, mid-
frequency and low-frequency sounds. For example, Jansen (1998) reported
on the relationship between acoustic exposures and physiological
responses that are indicative of stress responses in humans (for
example, elevated respiration and increased heart rates). Jones (1998)
reported on reductions in human performance when faced with acute,
repetitive exposures to acoustic disturbance. Trimper et al. (1998)
reported on the physiological stress responses of osprey to low-level
aircraft noise while Krausman et al. (2004) reported on the auditory
and physiology stress responses of endangered Sonoran pronghorn to
military overflights. Smith et al. (2004a, 2004b), for example,
identified noise-induced physiological transient stress responses in
hearing-specialist fish (i.e., goldfish) that accompanied short- and
long-term hearing losses. Welch and Welch (1970) reported physiological
and behavioral stress responses that accompanied damage to the inner
ears of fish and several mammals.
Hearing is one of the primary senses marine mammals use to gather
information about their environment and to communicate with
conspecifics. Although empirical information on the relationship
between sensory impairment (TTS, PTS, and acoustic masking) on marine
mammals remains limited, it seems reasonable to assume that reducing an
animal's ability to gather information about its environment and to
communicate with other members of its species would be stressful for
animals that use hearing as their primary sensory mechanism. Therefore,
we assume that acoustic exposures sufficient to trigger onset PTS or
TTS would be accompanied by physiological stress responses because
terrestrial animals exhibit those responses under similar conditions
(NRC 2003). More importantly, marine mammals might experience stress
responses at received levels lower than those necessary to trigger
onset TTS. Based on empirical studies of the time required to recover
from stress responses (Moberg 2000), we also assume that stress
responses are likely to persist beyond the time interval required for
animals to recover from TTS and might result in pathological and pre-
pathological states that would be as significant as behavioral
responses to TTS.
In general, there are few data on the potential for strong,
anthropogenic underwater sounds to cause non-auditory physical effects
in marine mammals. The available data do not allow identification of a
specific exposure level above which non-auditory effects can be
expected (Southall et al., 2007). There is no definitive evidence that
any of these effects occur even for marine mammals in close proximity
to an anthropogenic sound source. In addition, marine mammals that show
behavioral avoidance of survey vessels and related sound sources are
unlikely to incur non-auditory impairment or other physical effects.
NMFS does not expect that the generally short-term, intermittent, and
[[Page 7937]]
transitory HRG and geotechnical activities would create conditions of
long-term, continuous noise and chronic acoustic exposure leading to
long-term physiological stress responses in marine mammals.
Behavioral Disturbance
Behavioral disturbance may include a variety of effects, including
subtle changes in behavior (e.g., minor or brief avoidance of an area
or changes in vocalizations), more conspicuous changes in similar
behavioral activities, and more sustained and/or potentially severe
reactions, such as displacement from or abandonment of high-quality
habitat. Behavioral responses to sound are highly variable and context-
specific and any reactions depend on numerous intrinsic and extrinsic
factors (e.g., species, state of maturity, experience, current
activity, reproductive state, auditory sensitivity, time of day), as
well as the interplay between factors (e.g., Richardson et al., 1995;
Wartzok et al., 2003; Southall et al., 2007; Weilgart, 2007; Archer et
al., 2010). Behavioral reactions can vary not only among individuals
but also within an individual, depending on previous experience with a
sound source, context, and numerous other factors (Ellison et al.,
2012), and can vary depending on characteristics associated with the
sound source (e.g., whether it is moving or stationary, number of
sources, distance from the source). Please see Appendices B-C of
Southall et al. (2007) for a review of studies involving marine mammal
behavioral responses to sound.
Habituation can occur when an animal's response to a stimulus wanes
with repeated exposure, usually in the absence of unpleasant associated
events (Wartzok et al., 2003). Animals are most likely to habituate to
sounds that are predictable and unvarying. It is important to note that
habituation is appropriately considered as a ``progressive reduction in
response to stimuli that are perceived as neither aversive nor
beneficial,'' rather than as, more generally, moderation in response to
human disturbance (Bejder et al., 2009). The opposite process is
sensitization, when an unpleasant experience leads to subsequent
responses, often in the form of avoidance, at a lower level of
exposure. As noted, behavioral state may affect the type of response.
For example, animals that are resting may show greater behavioral
change in response to disturbing sound levels than animals that are
highly motivated to remain in an area for feeding (Richardson et al.,
1995; NRC 2003; Wartzok et al., 2003). Controlled experiments with
captive marine mammals have shown pronounced behavioral reactions,
including avoidance of loud sound sources (Ridgway et al., 1997;
Finneran et al., 2003). Observed responses of wild marine mammals to
loud, pulsed sound sources (typically seismic airguns or acoustic
harassment devices) have been varied but often consist of avoidance
behavior or other behavioral changes suggesting discomfort (Morton and
Symonds, 2002; see also Richardson et al., 1995; Nowacek et al., 2007).
Available studies show wide variation in response to underwater
sound; therefore, it is difficult to predict specifically how any given
sound in a particular instance might affect marine mammals perceiving
the signal. If a marine mammal does react briefly to an underwater
sound by changing its behavior or moving a small distance, the impacts
of the change are unlikely to be significant to the individual, let
alone the stock or population. However, if a sound source displaces
marine mammals from an important feeding or breeding area for a
prolonged period, impacts on individuals and populations could be
significant (e.g., Lusseau and Bejder, 2007; Weilgart 2007; NRC 2005).
However, there are broad categories of potential response, which we
describe in greater detail here, that include alteration of dive
behavior, alteration of foraging behavior, effects to breathing,
interference with or alteration of vocalization, avoidance, and flight.
Changes in dive behavior can vary widely and may consist of
increased or decreased dive times and surface intervals as well as
changes in the rates of ascent and descent during a dive (e.g., Frankel
and Clark 2000; Costa et al., 2003; Ng and Leung 2003; Nowacek et al.,
2004; Goldbogen et al., 2013a,b). Variations in dive behavior may
reflect interruptions in biologically significant activities (e.g.,
foraging) or they may be of little biological significance. The impact
of an alteration to dive behavior resulting from an acoustic exposure
depends on what the animal is doing at the time of the exposure and the
type and magnitude of the response.
Disruption of feeding behavior can be difficult to correlate with
anthropogenic sound exposure, so it is usually inferred by observed
displacement from known foraging areas, the appearance of secondary
indicators (e.g., bubble nets or sediment plumes), or changes in dive
behavior. As for other types of behavioral response, the frequency,
duration, and temporal pattern of signal presentation, as well as
differences in species sensitivity, are likely contributing factors to
differences in response in any given circumstance (e.g., Croll et al.,
2001; Nowacek et al.; 2004; Madsen et al., 2006; Yazvenko et al.,
2007). A determination of whether foraging disruptions incur fitness
consequences would require information on or estimates of the energetic
requirements of the affected individuals and the relationship between
prey availability, foraging effort and success, and the life history
stage of the animal.
Variations in respiration naturally vary with different behaviors
and alterations to breathing rate as a function of acoustic exposure
can be expected to co-occur with other behavioral reactions, such as a
flight response or an alteration in diving. However, respiration rates
in and of themselves may be representative of annoyance or an acute
stress response. Various studies have shown that respiration rates may
either be unaffected or could increase, depending on the species and
signal characteristics, again highlighting the importance in
understanding species differences in the tolerance of underwater noise
when determining the potential for impacts resulting from anthropogenic
sound exposure (e.g., Kastelein et al., 2001, 2005b, 2006; Gailey et
al., 2007).
Marine mammals vocalize for different purposes and across multiple
modes, such as whistling, echolocation click production, calling, and
singing. Changes in vocalization behavior in response to anthropogenic
noise can occur for any of these modes and may result from a need to
compete with an increase in background noise or may reflect increased
vigilance or a startle response. For example, in the presence of
potentially masking signals, humpback whales and killer whales have
been observed to increase the length of their songs (Miller et al.,
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales
have been observed to shift the frequency content of their calls upward
while reducing the rate of calling in areas of increased anthropogenic
noise (Parks et al., 2007b). In some cases, animals may cease sound
production during production of aversive signals (Bowles et al., 1994).
Avoidance is the displacement of an individual from an area or
migration path as a result of the presence of a sound or other
stressors, and is one of the most obvious manifestations of disturbance
in marine mammals (Richardson et al., 1995). For example, gray whales
are known to change direction--deflecting from customary migratory
paths--in order to avoid noise from seismic surveys (Malme et al.,
[[Page 7938]]
1984). Avoidance may be short-term, with animals returning to the area
once the noise has ceased (e.g., Bowles et al., 1994; Goold 1996; Stone
et al., 2000; Morton and Symonds, 2002; Gailey et al., 2007). Longer-
term displacement is possible, however, which may lead to changes in
abundance or distribution patterns of the affected species in the
affected region if habituation to the presence of the sound does not
occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann et
al., 2006).
A flight response is a dramatic change in normal movement to a
directed and rapid movement away from the perceived location of a sound
source. The flight response differs from other avoidance responses in
the intensity of the response (e.g., directed movement, rate of
travel). Relatively little information on flight responses of marine
mammals to anthropogenic signals exist, although observations of flight
responses to the presence of predators have occurred (Connor and
Heithaus, 1996). The result of a flight response could range from
brief, temporary exertion and displacement from the area where the
signal provokes flight to, in extreme cases, marine mammal strandings
(Evans and England, 2001). However, it should be noted that response to
a perceived predator does not necessarily invoke flight (Ford and
Reeves, 2008) and whether individuals are solitary or in groups may
influence the response.
Behavioral disturbance can also impact marine mammals in more
subtle ways. Increased vigilance may result in costs related to
diversion of focus and attention (i.e., when a response consists of
increased vigilance, it may come at the cost of decreased attention to
other critical behaviors such as foraging or resting). These effects
have generally not been demonstrated for marine mammals, but studies
involving fish and terrestrial animals have shown that increased
vigilance may substantially reduce feeding rates (e.g., Beauchamp and
Livoreil, 1997; Fritz et al., 2002; Purser and Radford, 2011). In
addition, chronic disturbance can cause population declines through
reduction of fitness (e.g., decline in body condition) and subsequent
reduction in reproductive success, survival, or both (e.g., Harrington
and Veitch, 1992; Daan et al., 1996; Bradshaw et al., 1998). However,
Ridgway et al. (2006) reported that increased vigilance in bottlenose
dolphins exposed to sound over a five-day period did not cause any
sleep deprivation or stress effects.
Many animals perform vital functions, such as feeding, resting,
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption
of such functions resulting from reactions to stressors such as sound
exposure are more likely to be significant if they last more than one
diel cycle or recur on subsequent days (Southall et al., 2007).
Consequently, a behavioral response lasting less than one day and not
recurring on subsequent days is not considered particularly severe
unless it could directly affect reproduction or survival (Southall et
al., 2007). Note that there is a difference between multi-day
substantive behavioral reactions and multi-day anthropogenic
activities. For example, just because an activity lasts for multiple
days does not necessarily mean that individual animals are either
exposed to activity-related stressors for multiple days or, further,
exposed in a manner resulting in sustained multi-day substantive
behavioral responses.
Marine mammals are likely to avoid the HRG survey activity,
especially the naturally shy harbor porpoise, while the harbor seals
might be attracted to them out of curiosity. However, because the sub-
bottom profilers and other HRG survey equipment operate from a moving
vessel, and the maximum radius to the Level B harassment threshold is
relatively small, the area and time that this equipment would be
affecting a given location is very small. Further, once an area has
been surveyed, it is not likely that it will be surveyed again, thereby
reducing the likelihood of repeated HRG-related impacts within the
survey area.
We have also considered the potential for severe behavioral
responses such as stranding and associated indirect injury or mortality
from Atlantic Shores's use of HRG survey equipment, on the basis of a
2008 mass stranding of approximately 100 melon-headed whales in a
Madagascar lagoon system. An investigation of the event indicated that
use of a high-frequency mapping system (12-kHz multibeam echosounder)
was the most plausible and likely initial behavioral trigger of the
event, while providing the caveat that there is no unequivocal and
easily identifiable single cause (Southall et al., 2013). The
investigatory panel's conclusion was based on (1) very close temporal
and spatial association and directed movement of the survey with the
stranding event; (2) the unusual nature of such an event coupled with
previously documented apparent behavioral sensitivity of the species to
other sound types (Southall et al., 2006; Brownell et al., 2009); and
(3) the fact that all other possible factors considered were determined
to be unlikely causes. Specifically, regarding survey patterns prior to
the event and in relation to bathymetry, the vessel transited in a
north-south direction on the shelf break parallel to the shore,
ensonifying large areas of deep-water habitat prior to operating
intermittently in a concentrated area offshore from the stranding site;
this may have trapped the animals between the sound source and the
shore, thus driving them towards the lagoon system. The investigatory
panel systematically excluded or deemed highly unlikely nearly all
potential reasons for these animals leaving their typical pelagic
habitat for an area extremely atypical for the species (i.e., a shallow
lagoon system). Notably, this was the first time that such a system has
been associated with a stranding event. The panel also noted several
site- and situation-specific secondary factors that may have
contributed to the avoidance responses that led to the eventual
entrapment and mortality of the whales. Specifically, shoreward-
directed surface currents and elevated chlorophyll levels in the area
preceding the event may have played a role (Southall et al., 2013). The
report also notes that prior use of a similar system in the general
area may have sensitized the animals and also concluded that, for
odontocete cetaceans that hear well in higher frequency ranges where
ambient noise is typically quite low, high-power active sonars
operating in this range may be more easily audible and have potential
effects over larger areas than low frequency systems that have more
typically been considered in terms of anthropogenic noise impacts. It
is, however, important to note that the relatively lower output
frequency, higher output power, and complex nature of the system
implicated in this event, in context of the other factors noted here,
likely produced a fairly unusual set of circumstances that indicate
that such events would likely remain rare and are not necessarily
relevant to use of lower-power, higher-frequency systems more commonly
used for HRG survey applications. The risk of similar events recurring
may be very low, given the extensive use of active acoustic systems
used for scientific and navigational purposes worldwide on a daily
basis and the lack of direct evidence of such responses previously
reported.
Tolerance
Numerous studies have shown that underwater sounds from industrial
activities are often readily detectable by marine mammals in the water
at distances of many km. However, other studies have shown that marine
mammals at distances more than a few
[[Page 7939]]
km away often show no apparent response to industrial activities of
various types (Miller et al., 2005). This is often true even in cases
when the sounds must be readily audible to the animals based on
measured received levels and the hearing sensitivity of that mammal
group. Although various baleen whales, toothed whales, and (less
frequently) pinnipeds have been shown to react behaviorally to
underwater sound from sources such as airgun pulses or vessels under
some conditions, at other times, mammals of all three types have shown
no overt reactions (e.g., Malme et al., 1986; Richardson et al., 1995;
Madsen and Mohl 2000; Croll et al., 2001; Jacobs and Terhune 2002;
Madsen et al., 2002; Miller et al., 2005). In general, pinnipeds seem
to be more tolerant of exposure to some types of underwater sound than
are baleen whales. Richardson et al. (1995) found that vessel sound
does not seem to affect pinnipeds that are already in the water.
Richardson et al. (1995) went on to explain that seals on haul-outs
sometimes respond strongly to the presence of vessels and at other
times appear to show considerable tolerance of vessels, and Brueggeman
et al. (1992) observed ringed seals (Pusa hispida) hauled out on ice
pans displaying short-term escape reactions when a ship approached
within 0.16-0.31 miles (0.25-0.5 km). Due to the relatively high vessel
traffic in the Lease Area it is possible that marine mammals are
habituated to noise (e.g., DP thrusters) from project vessels in the
area.
Vessel Strike
Ship strikes of marine mammals can cause major wounds, which may
lead to the death of the animal. An animal at the surface could be
struck directly by a vessel, a surfacing animal could hit the bottom of
a vessel, or a vessel's propeller could injure an animal just below the
surface. The severity of injuries typically depends on the size and
speed of the vessel (Knowlton and Kraus 2001; Laist et al., 2001;
Vanderlaan and Taggart 2007).
The most vulnerable marine mammals are those that spend extended
periods of time at the surface in order to restore oxygen levels within
their tissues after deep dives (e.g., the sperm whale). In addition,
some baleen whales, such as the North Atlantic right whale, seem
generally unresponsive to vessel sound, making them more susceptible to
vessel collisions (Nowacek et al., 2004). These species are primarily
large, slow moving whales. Smaller marine mammals (e.g., bottlenose
dolphin) move quickly through the water column and are often seen
riding the bow wave of large ships. Marine mammal responses to vessels
may include avoidance and changes in dive pattern (NRC 2003).
An examination of all known ship strikes from all shipping sources
(civilian and military) indicates vessel speed is a principal factor in
whether a vessel strike results in death (Knowlton and Kraus 2001;
Laist et al., 2001; Jensen and Silber 2003; Vanderlaan and Taggart
2007). In assessing records with known vessel speeds, Laist et al.
(2001) found a direct relationship between the occurrence of a whale
strike and the speed of the vessel involved in the collision. The
authors concluded that most deaths occurred when a vessel was traveling
in excess of 24.1 km/h (14.9 mph; 13 kn). Given the slow vessel speeds
and predictable course necessary for data acquisition, ship strike is
unlikely to occur during the geophysical and geotechnical surveys.
Marine mammals would be able to easily avoid the survey vessel due to
the slow vessel speed. Further, Atlantic Shores would implement
measures (e.g., protected species monitoring, vessel speed restrictions
and separation distances; see Proposed Mitigation) set forth in the
BOEM lease to reduce the risk of a vessel strike to marine mammal
species in the survey area.
Marine Mammal Habitat
The HRG survey equipment will not contact the seafloor and does not
represent a source of pollution. We are not aware of any available
literature on impacts to marine mammal prey from sound produced by HRG
survey equipment. However, as the HRG survey equipment introduces noise
to the marine environment, there is the potential for it to result in
avoidance of the area around the HRG survey activities on the part of
marine mammal prey. Any avoidance of the area on the part of marine
mammal prey would be expected to be short term and temporary.
Because of the temporary nature of the disturbance, and the
availability of similar habitat and resources (e.g., prey species) 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. Impacts on marine mammal habitat from the proposed
activities will be temporary, insignificant, and discountable.
Estimated Take
This section provides an estimate of the number of incidental takes
proposed for authorization through this IHA, which will inform both
NMFS' consideration of ``small numbers'' and the negligible impact
determination.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes would be by Level B harassment only, in the form
of disruption of behavioral patterns for individual marine mammals
resulting from exposure to HRG sources. Based on the nature of the
activity and the anticipated effectiveness of the mitigation measures
(i.e., exclusion zones and shutdown measures), discussed in detail
below in Proposed Mitigation section, Level A harassment is neither
anticipated nor proposed to be authorized.
As described previously, no mortality is anticipated or proposed to
be authorized for this activity. Below we describe how the take is
estimated.
Generally speaking, we estimate take by considering: (1) Acoustic
thresholds above which NMFS believes the best available science
indicates marine mammals will be behaviorally harassed or incur some
degree of permanent hearing impairment; (2) the area or volume of water
that will be ensonified above these levels in a day; (3) the density or
occurrence of marine mammals within these ensonified areas; and, (4)
and the number of days of activities. We note that while these basic
factors can contribute to a basic calculation to provide an initial
prediction of takes, additional information that can qualitatively
inform take estimates is also sometimes available (e.g., previous
monitoring results or average group size). Below, we describe the
factors considered here in more detail and present the proposed take
estimate.
Acoustic Thresholds
Using the best available science, NMFS has developed acoustic
thresholds that identify the received level of underwater sound above
which exposed marine mammals would be reasonably expected to be
behaviorally harassed (equated to Level B
[[Page 7940]]
harassment) or to incur PTS of some degree (equated to Level A
harassment).
Level B Harassment--Though significantly driven by received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source (e.g., frequency, predictability, duty cycle), the environment
(e.g., bathymetry), and the receiving animals (hearing, motivation,
experience, demography, behavioral context) and can be difficult to
predict (Southall et al., 2007, Ellison et al., 2012). Based on what
the available science indicates and the practical need to use a
threshold based on a factor that is both predictable and measurable for
most activities, NMFS uses a generalized acoustic threshold based on
received level to estimate the onset of behavioral harassment. NMFS
predicts that marine mammals are likely to be behaviorally harassed in
a manner we consider Level B harassment when exposed to underwater
anthropogenic noise above received levels of 160 dB re 1 [mu]Pa (rms)
for impulsive and/or intermittent sources (e.g., impact pile driving)
and 120 dB rms for continuous sources (e.g., vibratory driving).
Atlantic Shores's proposed activity includes the use of impulsive
sources (geophysical survey equipment) therefore use of the 120 and 160
dB re 1 [mu]Pa (rms) threshold is applicable.
Level A harassment--NMFS' Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0)
(Technical Guidance, 2018) identifies dual criteria to assess auditory
injury (Level A harassment) to five different 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 Atlantic Shores's proposed activity that may result in
the take of marine mammals include the use of impulsive sources.
These thresholds are provided in Table 4 below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS 2018 Technical Guidance, which may be accessed at:
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds \*\ (Received Level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 218 dB; Cell 8: LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that will feed into identifying the area ensonified above the
acoustic thresholds, which include source levels and transmission loss
coefficient.
The proposed survey would entail the use of HRG equipment. The
distance to the isopleth corresponding to the threshold for Level B
harassment was calculated for all HRG equipment with the potential to
result in harassment of marine mammals. NMFS has developed an interim
methodology for determining the rms sound pressure level
(SPLrms) at the 160-dB isopleth for the purposes of
estimating take by Level B harassment resulting from exposure to HRG
survey equipment (NMFS, 2019). This methodology incorporates frequency
and some directionality to refine estimated ensonified zones. Atlantic
Shores used the methods specified in the interim methodology (NMFS,
2019) with additional modifications to incorporate a seawater
absorption formula and a method to account for energy emitted outside
of the primary beam of the source. For sources that operate with
different beam widths, the maximum beam width was used. The lowest
frequency of the source was used when calculating the absorption
coefficient. The formulas used to apply the methodology are described
in detail in Appendix B of the IHA application.
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 isopleth distances to the Level B
harassment threshold. 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 1 shows the HRG equipment
types that may be used during the proposed surveys and the sound levels
associated with those HRG equipment types. Table 2-2 in the IHA
application shows the literature sources for the sound source levels
that are shown in Table 1 and that were incorporated into the modeling
of Level B isopleth distances to the Level B harassment threshold.
Results of modeling using the methodology described above indicated
that, of the HRG survey equipment planned for use by Atlantic Shores
that has the potential to result in harassment of marine mammals, sound
produced by the Applied Acoustics Dura-Spark 240 sparker would
propagate furthest to the
[[Page 7941]]
Level B harassment threshold (Table 5); therefore, for the purposes of
the exposure analysis, it was assumed the Applied Acoustics Dura-Spark
240 would be active during the entire duration of the surveys. Thus the
distance to the isopleth corresponding to the threshold for Level B
harassment for the Applied Acoustics Dura-Spark 240 (estimated at 372
m; Table 5) was used as the basis of the take calculation for all
marine mammals. Note that this results in a conservative estimate of
the total ensonified area resulting from the proposed activities as
Atlantic Shores may not operate the Applied Acoustics Dura-Spark 240
during the entire proposed survey, and for any survey segments in which
it is not ultimately operated the distance to the Level B harassment
threshold would be less than 372 m (Table 5). However, as Atlantic
Shores cannot predict the precise number of survey days that will
require the use of the Applied Acoustics Dura-Spark 240, it was assumed
that it would operated during the entire duration of the proposed
surveys.
Table 5--Modeled Radial Distances from HRG Survey Equipment to Isopleths Corresponding to Level A Harassment and
Level B Harassment Thresholds
----------------------------------------------------------------------------------------------------------------
Radial distance to level A harassment threshold (m) * Radial
---------------------------------------------------------------- distance to
Level B
harassment
Sound source Low frequency Mid frequency High frequency Phocid threshold (m)
cetaceans cetaceans cetaceans pinnipeds ---------------
(underwater) All marine
mammals
----------------------------------------------------------------------------------------------------------------
Kongsberg EA 400................ <1 2 213 <1 172
Teledyne ODOM Echotrac CVM...... <1 1 220 <1 173
Applied Acoustics Dura-Spark 240 1 <1 9 1 372
Edgetech 2000-DSS............... <1 <1 <1 <1 4
Edgetech 216.................... <1 <1 <1 <1 5
Edgetech 424.................... <1 <1 <1 <1 6
Edgetech 512i................... <1 <1 <1 <1 7
Teledyne Benthos Chirp III...... n/a n/a n/a n/a 71
Kongsberg GeoPulse.............. n/a n/a n/a n/a 231
Innomar SES-2000 Medium-100 <1 <1 60 <1 116
Parametric.....................
Applied Acoustics............... <1 <1 38 <1 97
S-Boom Triple Plate.............
Applied Acoustics............... <1 <1 13 <1 56
S-Boom..........................
----------------------------------------------------------------------------------------------------------------
* Distances to the Level A harassment threshold based on the larger of the dual criteria (peak SPL and SELcum)
are shown. For the Applied Acoustics Dura-Spark 240 the peak SPL metric resulted in larger isopleth distances;
for all other sources the SELcum metric resulted in larger isopleth distances.
Predicted distances to Level A harassment isopleths, which vary
based on marine mammal functional hearing groups (Table 4), were also
calculated. The updated acoustic thresholds for impulsive sounds (such
as HRG survey equipment) contained in the Technical Guidance (NMFS,
2018) were presented as dual metric acoustic thresholds using both
cumulative sound exposure level (SELcum) and peak sound
pressure level metrics. As dual metrics, NMFS considers onset of PTS
(Level A harassment) to have occurred when either one of the two
metrics is exceeded (i.e., the 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.
Modeling of distances to isopleths corresponding to the Level A
harassment threshold was performed for all types of HRG equipment
proposed for use with the potential to result in harassment of marine
mammals. Atlantic Shores used a new model developed by JASCO to
calculate distances to Level A harassment isopleths based on both the
peak SPL and the SELcum metric. For the peak SPL metric, the
model is a series of equations that accounts for both seawater
absorption and HRG equipment beam patterns (for all HRG sources with
beam widths larger than 90[deg], it was assumed these sources were
omnidirectional). For the SELcum metric, a model was
developed that accounts for the hearing sensitivity of the marine
mammal group, seawater absorption, and beam width for downwards-facing
transducers. Details of the modeling methodology for both the peak SPL
and SELcum metrics are provided in Appendix A of the IHA
application. This model entails the following steps:
1. Weighted broadband source levels were calculated by assuming a
flat spectrum between the source minimum and maximum frequency,
weighted the spectrum according to the marine mammal hearing group
weighting function (NMFS 2018), and summed across frequency.
2. Propagation loss was modeled as a function of oblique range.
3. Per-pulse SEL was modeled for a stationary receiver at a fixed
distance off a straight survey line, using a vessel transit speed of
3.5 knots and source-specific pulse length and repetition rate. The
off-line distance is referred to as the closest point of approach (CPA)
and was performed for CPA distances between 1 m and 10 km. The survey
line length was modeled as 10 km long (analysis showed longer survey
lines increased SEL by a negligible amount). SEL is calculated as SPL +
10 log10 T/15 dB, where T is the pulse duration.
4. The SEL for each survey line was calculated to produce curves of
weighted SEL as a function of CPA distance.
5. The curves from Step 4 above were used to estimate the CPA
distance to the impact criteria.
We note that in the modeling methods described above and in
Appendix A of the IHA application, sources that operate with a
repetition rate greater than 10 Hz were assessed with the non-impulsive
(intermittent) source criteria while sources with a repetition rate
equal to or less than 10 Hz were assessed with the impulsive source
criteria. NMFS does not necessarily agree with this step in the
modeling
[[Page 7942]]
assessment, which results in nearly all HRG sources being classified as
impulsive; however, we note that the classification of the majority of
HRG sources as impulsive results in more conservative modeling results.
Thus, we have assessed the potential for Level A harassment to result
from the proposed activities based on the modeled Level A zones with
the acknowledgement that these zones are likely conservative.
Modeled isopleth distances to Level A harassment thresholds for all
types of HRG equipment and all marine mammal functional hearing groups
are shown in Table 5. The dual criteria (peak SPL and
SELcum) were applied to all HRG sources using the modeling
methodology as described above, and the largest isopleth distances for
each functional hearing group were then carried forward in the exposure
analysis to be conservative. For the Applied Acoustics Dura-Spark 240
the peak SPL metric resulted in larger isopleth distances; for all HRG
sources other than the Applied Acoustics Dura-Spark 240, the
SELcum metric resulted in larger isopleth distances.
Distances to the Level A harassment threshold based on the larger of
the dual criteria (peak SPL and SELcum) are shown in Table
5.
Modeled distances to isopleths corresponding to the Level A
harassment threshold are very small (< 3 m) for three of the four
marine mammal functional hearing groups that may be impacted by the
proposed activities (i.e., low frequency and mid frequency cetaceans,
and phocid pinnipeds; see Table 5). Based on the very 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 proposed
activities. There is one species (harbor porpoise) within the high
frequency functional hearing group that may be impacted by the proposed
activities. The largest modeled distance to the Level A harassment
threshold for the high frequency functional hearing group was 220 m
(Table 5). However, as noted above, modeled distances to isopleths
corresponding to the Level A harassment threshold are assumed to be
conservative. 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, and mitigation measures--including a 100-
m exclusion zone for harbor porpoises--are expected to minimize the
potential for close approach or longer duration exposure to active HRG
sources. In addition, harbor porpoises are a notoriously shy species
which is known to avoid vessels, and would also be expected to avoid a
sound source prior to that source reaching a level that would result in
injury (Level A harassment). Therefore, we have determined that the
potential for take by Level A harassment of harbor porpoises is so low
as to be discountable. 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 proposed surveys is so low as to be discountable, we
therefore do not propose to authorize the take by Level A harassment of
any marine mammals.
Marine Mammal Occurrence
In this section we provide the information about the presence,
density, or group dynamics of marine mammals that will inform the take
calculations.
The habitat-based density models produced by the Duke University
Marine Geospatial Ecology Laboratory (Roberts et al., 2016, 2017, 2018)
represent the best available information regarding marine mammal
densities in the proposed survey area. The density data presented by
Roberts et al. (2016, 2017, 2018) incorporates aerial and shipboard
line-transect survey data from NMFS and other organizations and
incorporates data from 8 physiographic and 16 dynamic oceanographic and
biological covariates, and controls for the influence of sea state,
group size, availability bias, and perception bias on the probability
of making a sighting. These density models were originally developed
for all cetacean taxa in the U.S. Atlantic (Roberts et al., 2016). In
subsequent years, certain models have been updated on the basis of
additional data as well as certain methodological improvements. Our
evaluation of the changes leads to a conclusion that these represent
the best scientific evidence available. More information, including the
model results and supplementary information for each model, is
available online at seamap.env.duke.edu/models/Duke-EC-GOM-2015/.
Marine mammal density estimates in the project area (animals/km\2\)
were obtained using these model results (Roberts et al., 2016, 2017,
2018). The updated models incorporate additional sighting data,
including sightings from the NOAA Atlantic Marine Assessment Program
for Protected Species (AMAPPS) surveys from 2010-2014 (NEFSC & SEFSC,
2011, 2012, 2014a, 2014b, 2015, 2016).
For the exposure analysis, density data from Roberts et al. (2016,
2017, 2018) were mapped using a geographic information system (GIS).
The density coverages that included any portion of the proposed project
area were selected for all potential survey months. For each of the
survey areas (i.e., Lease Area, CER North and ECR South), the densities
of each species as reported by Roberts et al. (2016, 2017, 2018) were
averaged by season; thus, a density was calculated for each species for
spring, summer, fall and winter. To be conservative, the greatest
seasonal density calculated for each species was then carried forward
in the exposure analysis. Estimated seasonal densities (animals per
km\2\) of all marine mammal species that may be taken by the proposed
survey, for all survey areas are shown in Tables B-1, B-2 and B-3 in
Appendix C of the IHA application. The maximum seasonal density values
used to estimate take numbers are shown in Table 6 below.
For bottlenose dolphin densities, Roberts et al. (2016, 2017, 2018)
does not differentiate by stock. The Western North Atlantic northern
migratory coastal stock only occurs in coastal waters from the
shoreline to approximately the 20-m isobath (Hayes et al. 2018). As the
Lease Area is located within depths exceeding 20-m, where only the
offshore stock would be expected to occur, all calculated bottlenose
dolphin exposures within the Lease Area were assigned to the offshore
stock. However, both stocks have the potential to occur in the ECR
North and ECR South survey areas. To account for the potential for
mixed stocks within ECR North and South, the survey areas ECR North and
South were divided approximately along the 20-m depth isobath, which
roughly corresponds to the 10-fathom contour on NOAA navigation charts.
As approximately 33 percent of ECR North and ECR South are 20-m or less
in depth, 33 percent of the estimated take calculation for bottlenose
dolphins was applied to the Western North Atlantic northern migratory
coastal stock and the remaining 67 percent was applied to the offshore
stock. Similarly, Roberts et al. (2018) produced density models for all
seals and did not differentiate by seal species. Because the
seasonality and habitat use by gray seals roughly overlaps with that of
harbor seals in the survey areas, it was assumed that modeled takes of
seals could occur to either of the respective species, thus the total
number of modeled takes for seals was applied to each species.
[[Page 7943]]
Table 6--Maximum Seasonal Marine Mammal Densities (Number of Animals per 100 km\2\) in the Survey Areas
----------------------------------------------------------------------------------------------------------------
Species Lease area ECR north ECR south
----------------------------------------------------------------------------------------------------------------
North Atlantic right whale...................................... 0.087 0.068 0.073
Humpback whale.................................................. 0.076 0.082 0.103
Fin whale....................................................... 0.100 0.080 0.057
Sei whale....................................................... 0.004 0.004 0.002
Minke whale..................................................... 0.055 0.017 0.019
Sperm Whale..................................................... 0.013 0.005 0.003
Long-finned pilot whale......................................... 0.036 0.012 0.009
Bottlenose dolphin (W. N. Atlantic Coastal Migratory)........... .............. 21.675 58.524
Bottlenose dolphin (W. N. Atlantic Offshore).................... 21.752 21.675 58.524
Common dolphin.................................................. 3.120 1.644 1.114
Atlantic white-sided dolphin.................................... 0.487 0.213 0.152
Atlantic spotted dolphin........................................ 0.076 0.059 0.021
Risso's dolphin................................................. 0.010 0.001 0.002
Harbor porpoise................................................. 2.904 7.357 2.209
Gray seal....................................................... 4.918 9.737 6.539
Harbor seal..................................................... 4.918 9.737 6.539
----------------------------------------------------------------------------------------------------------------
Note: All density values derived from Roberts et al. (2016, 2017, 2018). Densities shown represent the maximum
seasonal density values calculated.
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate.
In order to estimate the number of marine mammals predicted to be
exposed to sound levels that would result in harassment, radial
distances to predicted isopleths corresponding to harassment thresholds
are calculated, as described above. Those distances are then used to
calculate the area(s) around the HRG survey equipment predicted to be
ensonified to sound levels that exceed harassment thresholds. The area
estimated to be ensonified to relevant thresholds in a single day is
then calculated, based on areas predicted to be ensonified around the
HRG survey equipment and the estimated trackline distance traveled per
day by the survey vessel.
Atlantic Shores estimates that proposed surveys will achieve a
maximum daily track line distance of 85 km per day during proposed HRG
surveys. This distance accounts for the vessel traveling at
approximately 3.5 kn and accounts for non-active survey periods. Based
on the maximum estimated distance to the Level B harassment threshold
of 372 m (Table 5) and the maximum estimated daily track line distance
of 85 km, an area of 63.675 km\2\ would be ensonified to the Level B
harassment threshold per day during Atlantic Shores' proposed surveys.
As described above, this is a conservative estimate as it assumes the
HRG source that results in the greatest isopleth distance to the Level
B harassment threshold would be operated at all times during the entire
survey, which may not ultimately occur.
The number of marine mammals expected to be incidentally taken per
day is then calculated by estimating the number of each species
predicted to occur within the daily ensonified area (animals/km\2\),
incorporating the estimated marine mammal densities as described above.
Estimated numbers of each species taken per day are then multiplied by
the total number of survey days (i.e., 350). The product is then
rounded, to generate an estimate of the total number of instances of
harassment expected for each species over the duration of the survey. A
summary of this method is illustrated in the following formula:
Estimated Take = D x ZOI x # of days
Where: D = average species density (per km\2\) and ZOI = maximum
daily ensonified area to relevant thresholds.
Table 7--Numbers of Potential Incidental Take of Marine Mammals Proposed for Authorization and Proposed Takes as
a Percentage of Population
----------------------------------------------------------------------------------------------------------------
Total proposed
Proposed takes Estimated Proposed takes Total takes instances of
Species by level A takes by level by level B proposed for take as a
harassment B harassment harassment authorization percentage of
population \1\
----------------------------------------------------------------------------------------------------------------
North Atlantic right whale...... 0 18 9 9 2.2
Humpback whale.................. 0 18 18 18 1.1
Fin whale....................... 0 20 20 20 0.4
Sei whale....................... 0 1 1 1 0.1
Minke whale..................... 0 9 9 9 0.4
Sperm whale \2\................. 0 2 3 3 0.1
Long-finned pilot whale......... 0 6 6 6 0.0
Bottlenose dolphin (W.N. 0 1,102 1,102 1,102 16.6
Atlantic Coastal Migratory)....
Bottlenose dolphin (W.N. 0 5,113 5,113 5,113 8.1
Atlantic Offshore).............
Common dolphin.................. 0 544 544 544 0.6
Atlantic white-sided dolphin.... 0 82 82 82 0.2
Atlantic spotted dolphin \2\.... 0 14 100 100 0.2
Risso's Dolphin \2\............. 0 2 6 6 0.1
Harbor porpoise................. 0 115 115 115 0.3
Harbor seal..................... 0 1,404 1,404 1,404 1.9
[[Page 7944]]
Gray seal....................... 0 1,404 1,404 1,404 0.3
----------------------------------------------------------------------------------------------------------------
\1\ Calculations of percentage of stock taken are based on the best available abundance estimate as shown in
Table 3. In most cases the best available abundance estimate is provided by Roberts et al. (2016, 2017, 2018),
when available, to maintain consistency with density estimates derived from Roberts et al. (2016, 2017, 2018).
For North Atlantic right whales the best available abundance estimate is derived from the North Atlantic Right
Whale Consortium 2019 Annual Report Card (Pettis et al., 2019). For bottlenose dolphins and seals, Roberts et
al. (2016, 2017, 2018) provides only a single abundance estimate and does not provide abundance estimates at
the stock or species level (respectively), so abundance estimates used to estimate percentage of stock taken
for bottlenose dolphins, gray and harbor seals are derived from NMFS SARs (Hayes et al., 2019).
\2\ The proposed number of authorized takes (Level B harassment only) for these species has been increased from
the estimated take number to mean group size. Sources for mean group size estimates are as follows: Risso's
dolphin: Palka et al. (2018); Atlantic spotted dolphin: Herzing and Perrin (2018); sperm whale: Barkaszi and
Kelly (2019).
The numbers of takes proposed for authorization are shown in Table
7. Atlantic Shores did not request take authorization for four marine
mammal species for which takes by Level B harassment were calculated
based on the modeling approach described above: North Atlantic right,
fin, sei, and sperm whale. Though the modeling resulted in estimates of
take for these species as shown in Table 7, Atlantic Shores determined
that take of these species could be avoided due to mitigation. However,
given the size of modeled Level B harassment zone, the duration of the
proposed surveys, and the fact that surveys will occur 24 hours per
day, NMFS is not confident that all takes of these species could be
avoided due to mitigation, and we therefore propose to authorize the
number of Level B takes modeled for these species, as shown in Table 7.
For fin, sei, and sperm whales we propose to authorize the number of
takes modeled. For North Atlantic right whale, we propose to authorize
50 percent of the takes modeled, as we expect that proposed mitigation
measures, including a 500-m exclusion zone for right whales (which
exceeds the Level B harassment zone by over 100-m) will be effective in
reducing the potential for takes by Level B harassment.
As described above, Roberts et al. (2018) produced density models
for all seals and did not differentiate by seal species. The take
calculation methodology as described above resulted in an estimate of
1,404 total seal takes. Based on this estimate, Atlantic Shores
requested 1,404 takes each of harbor and gray seals, based on an
assumption that the modeled takes could occur to either of the
respective species. We think this is a reasonable approach and
therefore propose to authorize the take numbers as shown in Table 7.
Using the take methodology approach described above, the take
estimates for Risso's dolphin, spotted dolphin and sperm whale were
less than the average group sizes estimated for these species (Table
7). However, information on the social structures of these species
indicates these species are likely to be encountered in groups.
Therefore it is reasonable to conservatively assume that one group of
each of these species will be taken during the proposed survey. We
therefore propose to authorize the take of the average group size for
these species to account for the possibility that the proposed survey
encounters a group of either of these species (Table 7).
As described above, 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 proposed surveys is so low as to be discountable;
therefore, we do not propose to authorize take of any marine mammals by
Level A harassment.
Proposed Mitigation
In order to issue an IHA under Section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to such
activity, and other means of effecting the least practicable impact on
such species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of such species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting such
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, we
carefully consider two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned), the likelihood of effective implementation (probability
implemented as planned), and;
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost, impact on
operations, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
Proposed Mitigation Measures
NMFS proposes the following mitigation measures be implemented
during Atlantic Shores's proposed marine site characterization surveys.
Marine Mammal Exclusion Zones, Buffer Zone and Monitoring Zone
Marine mammal exclusion zones (EZ) would be established around the
HRG
[[Page 7945]]
survey equipment and monitored by protected species observers (PSO)
during HRG surveys as follows:
A 500-m EZ would be required for North Atlantic right
whales; and
A 100-m EZ would be required for all other marine mammals.
If a marine mammal is detected approaching or entering the EZs
during the proposed survey, the vessel operator would adhere to the
shutdown procedures described below. In addition to the EZs described
above, PSOs would visually monitor a 200 m Buffer Zone. During use of
acoustic sources with the potential to result in marine mammal
harassment (i.e., anytime the acoustic source is active, including
ramp-up), occurrences of marine mammals within the Buffer Zone (but
outside the EZs) would be communicated to the vessel operator to
prepare for potential shutdown of the acoustic source. The Buffer Zone
is not applicable when the EZ is greater than 100 meters. PSOs would
also be required to observe a 500-m Monitoring Zone and record the
presence of all marine mammals within this zone. In addition, any
marine mammals observed within 372 m of the HRG equipment would be
documented by PSOs as taken by Level B harassment. The zones described
above would be based upon the radial distance from the active equipment
(rather than being based on distance from the vessel itself).
Visual Monitoring
A minimum of one NMFS-approved PSO must be on duty and conducting
visual observations at all times during daylight hours (i.e., from 30
minutes prior to sunrise through 30 minutes following sunset) and 30
minutes prior to and during nighttime ramp-ups of HRG equipment. Visual
monitoring would begin no less than 30 minutes prior to ramp-up of HRG
equipment and would continue until 30 minutes after use of the acoustic
source ceases or until 30 minutes past sunset. PSOs would establish and
monitor the applicable EZs, Buffer Zone and Monitoring Zone as
described above. Visual PSOs would coordinate to ensure 360[deg] visual
coverage around the vessel from the most appropriate observation posts,
and would conduct visual observations using binoculars and the naked
eye while free from distractions and in a consistent, systematic, and
diligent manner. PSOs would estimate distances to marine mammals
located in proximity to the vessel and/or relevant using range finders.
It would be the responsibility of the Lead PSO on duty to communicate
the presence of marine mammals as well as to communicate and enforce
the action(s) that are necessary to ensure mitigation and monitoring
requirements are implemented as appropriate. Position data would be
recorded using hand-held or vessel global positioning system (GPS)
units for each confirmed marine mammal sighting.
Pre-Clearance of the Exclusion Zones
Prior to initiating HRG survey activities, Atlantic Shores would
implement a 30-minute pre-clearance period. During pre-clearance
monitoring (i.e., before ramp-up of HRG equipment begins), the Buffer
Zone would also act as an extension of the 100 m EZ in that
observations of marine mammals within the 200 m Buffer Zone would also
preclude HRG operations from beginning. During this period, PSOs would
ensure that no marine mammals are observed within 200 m of the survey
equipment (500 m in the case of North Atlantic right whales). HRG
equipment would not start up until this 200 m zone (or, 500 m zone in
the case of North Atlantic right whales) is clear of marine mammals for
at least 30 minutes. The vessel operator would notify a designated PSO
of the planned start of HRG survey equipment as agreed upon with the
lead PSO; the notification time should not be less than 30 minutes
prior to the planned initiation of HRG equipment order to allow the
PSOs time to monitor the EZs and Buffer Zone for the 30 minutes of pre-
clearance. A PSO conducting pre-clearance observations would be
notified again immediately prior to initiating active HRG sources.
If a marine mammal were observed within the relevant EZs or Buffer
Zone during the pre-clearance period, initiation of HRG survey
equipment would not begin until the animal(s) has been observed exiting
the respective EZ or Buffer Zone, or, until an additional time period
has elapsed with no further sighting (i.e., minimum 15 minutes for
small odontocetes and seals, and 30 minutes for all other species). The
pre-clearance requirement would include small delphinoids that approach
the vessel (e.g., bow ride). PSOs would also continue to monitor the
zone for 30 minutes after survey equipment is shut down or survey
activity has concluded.
Ramp-Up of Survey Equipment
When technically feasible, a ramp-up procedure would be used for
geophysical survey equipment capable of adjusting energy levels at the
start or re-start of survey activities. The ramp-up procedure would be
used at the beginning of HRG survey activities in order to provide
additional protection to marine mammals near the survey area by
allowing them to detect the presence of the survey and vacate the area
prior to the commencement of survey equipment operation at full power.
Ramp-up of the survey equipment would not begin until the relevant EZs
and Buffer Zone has been cleared by the PSOs, as described above. HEG
equipment would be initiated at their lowest power output and would be
incrementally increased to full power. If any marine mammals are
detected within the EZs or Buffer Zone prior to or during ramp-up, the
HRG equipment would be shut down (as described below).
Shutdown Procedures
If an HRG source is active and a marine mammal is observed within
or entering a relevant EZ (as described above) an immediate shutdown of
the HRG survey equipment would be required. When shutdown is called for
by a PSO, the acoustic source would be immediately deactivated and any
dispute resolved only following deactivation. Any PSO on duty would
have the authority to delay the start of survey operations or to call
for shutdown of the acoustic source if a marine mammal is detected
within the applicable EZ. The vessel operator would establish and
maintain clear lines of communication directly between PSOs on duty and
crew controlling the HRG source(s) to ensure that shutdown commands are
conveyed swiftly while allowing PSOs to maintain watch. Subsequent
restart of the HRG equipment would only occur after the marine mammal
has either been observed exiting the relevant EZ, or, until an
additional time period has elapsed with no further sighting of the
animal within the relevant EZ (i.e., 15 minutes for small odontocetes
and seals, and 30 minutes for large whales).
Upon implementation of shutdown, the HRG source may be reactivated
after the marine mammal that triggered the shutdown has been observed
exiting the applicable EZ (i.e., the animal is not required to fully
exit the Buffer Zone where applicable), or, following a clearance
period of 15 minutes for small odontocetes and seals and 30 minutes for
all other species with no further observation of the marine mammal(s)
within the relevant EZ. If the HRG equipment shuts down for brief
periods (i.e., less than 30 minutes) for reasons other than mitigation
(e.g., mechanical or electronic failure) the equipment may be re-
activated as soon as is practicable at full operational level, without
30 minutes of pre-clearance, only if PSOs have maintained constant
visual observation during the shutdown and
[[Page 7946]]
no visual detections of marine mammals occurred within the applicable
EZs and Buffer Zone during that time. For a shutdown of 30 minutes or
longer, or if visual observation was not continued diligently during
the pause, pre-clearance observation is required, as described above.
The shutdown requirement would be waived for certain genera of
small delphinids (i.e., Delphinus, Lagenorhynchus, Stenella, and
Tursiops) under certain circumstances. If a delphinid(s) from these
genera is visually detected approaching the vessel (i.e., to bow ride)
or towed survey equipment, shutdown would not be required. 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 would use best professional
judgment in making the decision to call for a shutdown.
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 have been met, approaches or is observed within the
area encompassing the Level B harassment isopleth (372 m), shutdown
would occur.
Vessel Strike Avoidance
Vessel strike avoidance measures would include, but would not be
limited to, the following, except under circumstances when complying
with these requirements would put the safety of the vessel or crew at
risk:
All vessel operators and crew will maintain vigilant watch
for cetaceans and pinnipeds, and slow down or stop their vessel to
avoid striking these protected species;
All survey vessels, regardless of size, must observe a 10-
knot speed restriction in specific areas designated by NMFS for the
protection of North Atlantic right whales from vessel strikes: Any DMAs
when in effect, and the Mid-Atlantic SMA off the entrance to New York
harbor (from November 1 through April 30);
All vessel operators will reduce vessel speed to 10 knots
(18.5 km/hr) or less when any large whale, any mother/calf pairs, large
assemblages of non-delphinoid cetaceans are observed near (within 100 m
(330 ft)) an underway vessel;
All survey vessels will maintain a separation distance of
500 m (1640 ft) or greater from any sighted North Atlantic right whale;
If underway, vessels must steer a course away from any
sighted North Atlantic right whale at 10 knots (18.5 km/hr) or less
until the 500 m (1640 ft) minimum separation distance has been
established. If a North Atlantic right whale is sighted in a vessel's
path, or within 100 m (330 ft) to an underway vessel, the underway
vessel must reduce speed and shift the engine to neutral. Engines will
not be engaged until the North Atlantic right whale has moved outside
of the vessel's path and beyond 100 m. If stationary, the vessel must
not engage engines until the North Atlantic right whale has moved
beyond 100 m;
All vessels will maintain a separation distance of 100 m
(330 ft) or greater from any sighted non-delphinoid cetacean. If
sighted, the vessel underway must reduce speed and shift the engine to
neutral, and must not engage the engines until the non-delphinoid
cetacean has moved outside of the vessel's path and beyond 100 m. If a
survey vessel is stationary, the vessel will not engage engines until
the non-delphinoid cetacean has moved out of the vessel's path and
beyond 100 m;
All vessels will maintain a separation distance of 50 m
(164 ft) or greater from any sighted delphinoid cetacean. Any vessel
underway remain parallel to a sighted delphinoid cetacean's course
whenever possible, and avoid excessive speed or abrupt changes in
direction. Any vessel underway reduces vessel speed to 10 knots (18.5
km/hr) or less when pods (including mother/calf pairs) or large
assemblages of delphinoid cetaceans are observed. Vessels may not
adjust course and speed until the delphinoid cetaceans have moved
beyond 50 m and/or the abeam of the underway vessel;
All vessels will maintain a separation distance of 50 m
(164 ft) or greater from any sighted pinniped; and
All vessels underway will not divert or alter course in
order to approach any whale, delphinoid cetacean, or pinniped. Any
vessel underway will avoid excessive speed or abrupt changes in
direction to avoid injury to the sighted cetacean or pinniped.
Atlantic Shores will ensure that vessel operators and crew maintain
a vigilant watch for marine mammals by slowing down or stopping the
vessel to avoid striking marine mammals. Project-specific training will
be conducted for all vessel crew prior to the start of survey
activities. Confirmation of the training and understanding of the
requirements will be documented on a training course log sheet. Signing
the log sheet will certify that the crew members understand and will
comply with the necessary requirements throughout the survey
activities.
Seasonal Operating Requirements
As described above, the section of the proposed survey area
partially overlaps with a portion of a North Atlantic right whale SMA
off the port of New York/New Jersey. This SMA is active from November 1
through April 30 of each year. All survey vessels, regardless of
length, would be required to adhere to vessel speed restrictions (<10
kn) when operating within the SMA during times when the SMA is active.
In addition, between watch shifts, members of the monitoring team would
consult NMFS' North Atlantic right whale reporting systems for the
presence of North Atlantic right whales throughout survey operations.
Members of the monitoring team would also monitor the NMFS North
Atlantic right whale reporting systems for the establishment of Dynamic
Management Areas (DMA). If NMFS should establish a DMA in the survey
area while surveys are underway, Atlantic Shores would contact NMFS
within 24 hours of the establishment of the DMA to determine whether
alteration of survey activities was warranted to avoid right whales to
the extent possible.
The proposed mitigation measures are designed to avoid the already
low potential for injury in addition to some instances of Level B
harassment, and to minimize the potential for vessel strikes. Further,
we believe the proposed mitigation measures are practicable for the
applicant to implement. Atlantic Shores has proposed additional
mitigation measures in addition to the measures described above; for
information on the measures proposed by Atlantic Shores, see Section 11
of the IHA application.
There are no known marine mammal rookeries or mating or calving
grounds in the survey area that would otherwise potentially warrant
increased mitigation measures for marine mammals or their habitat (or
both). The proposed survey would occur in an area that has been
identified as a biologically important area for migration for North
Atlantic right whales. However, given the small spatial extent of the
survey area relative to the substantially larger spatial extent of the
right whale migratory area, the survey is not expected to appreciably
reduce migratory habitat nor to negatively impact the migration of
North Atlantic right whales, thus mitigation to address the proposed
survey's occurrence in North Atlantic right whale migratory habitat is
not warranted.
Based on our evaluation of the applicant's proposed measures, as
well as other measures considered by NMFS,
[[Page 7947]]
NMFS has preliminarily determined that the proposed mitigation measures
provide the means effecting the least practicable impact on the
affected species or stocks and their habitat, paying particular
attention to rookeries, mating grounds, and areas of similar
significance.
Proposed Monitoring and Reporting
In order to issue an IHA for an activity, Section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present in the
proposed action area. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density).
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas).
Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or 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.
Proposed Monitoring Measures
As described above, visual monitoring would be performed by
qualified and NMFS-approved PSOs. Atlantic Shores would use
independent, dedicated, trained PSOs, meaning that the PSOs must be
employed by a third-party observer provider, must have no tasks other
than to conduct observational effort, collect data, and communicate
with and instruct relevant vessel crew with regard to the presence of
marine mammals and mitigation requirements (including brief alerts
regarding maritime hazards), and must have successfully completed an
approved PSO training course appropriate for their designated task.
Atlantic Shores would provide resumes of all proposed PSOs (including
alternates) to NMFS for review and approval at least 45 days prior to
the start of survey operations.
During survey operations (e.g., any day on which use of an HRG
source is planned to occur), a minimum of one PSO must be on duty and
conducting visual observations at all times on all active survey
vessels during daylight hours (i.e., from 30 minutes prior to sunrise
through 30 minutes following sunset) and nighttime ramp-ups of HRG
equipment. Visual monitoring would begin no less than 30 minutes prior
to initiation of HRG survey equipment and would continue until one hour
after use of the acoustic source ceases or until 30 minutes past
sunset. PSOs would coordinate to ensure 360[deg] visual coverage around
the vessel from the most appropriate observation posts, and would
conduct visual observations using binoculars and the naked eye while
free from distractions and in a consistent, systematic, and diligent
manner. PSOs may be on watch for a maximum of four consecutive hours
followed by a break of at least two hours between watches and may
conduct a maximum of 12 hours of observation per 24-hour period. In
cases where multiple vessels are surveying concurrently, any
observations of marine mammals would be communicated to PSOs on all
survey vessels.
PSOs would be equipped with binoculars and have the ability to
estimate distances to marine mammals located in proximity to the vessel
and/or exclusion zone using range finders. Reticulated binoculars will
also be available to PSOs for use as appropriate based on conditions
and visibility to support the monitoring of marine mammals. Position
data would be recorded using hand-held or vessel GPS units for each
sighting. Observations would take place from the highest available
vantage point on the survey vessel. General 360-degree scanning would
occur during the monitoring periods, and target scanning by the PSO
would occur when alerted of a marine mammal presence.
During good conditions (e.g., daylight hours; Beaufort sea state
(BSS) 3 or less), to the maximum extent practicable, PSOs would conduct
observations when the acoustic source is not operating for comparison
of sighting rates and behavior with and without use of the acoustic
source and between acquisition periods. Any observations of marine
mammals by crew members aboard any vessel associated with the survey
would be relayed to the PSO team.
Data on all PSO observations would be recorded based on standard
PSO collection requirements. This would include dates, times, and
locations of survey operations; dates and times of observations,
location and weather; details of marine mammal sightings (e.g.,
species, numbers, behavior); and details of any observed marine mammal
take that occurs (e.g., noted behavioral disturbances).
Proposed Reporting Measures
Within 90 days after completion of survey activities, a final
technical report will be provided to NMFS that fully documents the
methods and monitoring protocols, summarizes the data recorded during
monitoring, summarizes the number of marine mammals estimated to have
been taken during survey activities (by species, when known),
summarizes the mitigation actions taken during surveys (including what
type of mitigation and the species and number of animals that prompted
the mitigation action, when known), and provides an interpretation of
the results and effectiveness of all mitigation and monitoring. Any
recommendations made by NMFS must be addressed in the final report
prior to acceptance by NMFS.
In addition to the final technical report, Atlantic Shores will
provide the reports described below as necessary during survey
activities. In the unanticipated event that Atlantic Shores' activities
lead to an injury (Level A harassment) of a marine mammal, Atlantic
Shores would immediately cease the specified activities and report the
incident to the NMFS Office of Protected Resources Permits and
Conservation Division and the NMFS New England/Mid-Atlantic Stranding
Coordinator. The report would include the following information:
Time, date, and location (latitude/longitude) of the
incident;
Name and type of vessel involved;
[[Page 7948]]
Vessel's speed during and leading up to the incident;
Description of the incident;
Status of all sound source use in the 24 hours preceding
the incident;
Water depth;
Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, and visibility);
Description of all marine mammal observations in the 24
hours preceding the incident;
Species identification or description of the animal(s)
involved;
Fate of the animal(s); and
Photographs or video footage of the animal(s) (if
equipment is available).
Activities would not resume until NMFS is able to review the
circumstances of the event. NMFS would work with Atlantic Shores to
minimize reoccurrence of such an event in the future. Atlantic Shores
would not resume activities until notified by NMFS.
In the event that Atlantic Shores personnel discover an injured or
dead marine mammal, Atlantic Shores would report the incident to the
OPR Permits and Conservation Division and the NMFS New England/Mid-
Atlantic Stranding Coordinator as soon as feasible. The report would
include the following information:
Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
Species identification (if known) or description of the
animal(s) involved;
Condition of the animal(s) (including carcass condition if
the animal is dead);
Observed behaviors of the animal(s), if alive;
If available, photographs or video footage of the
animal(s); and
General circumstances under which the animal was
discovered.
In the unanticipated event of a ship strike of a marine mammal by
any vessel involved in the activities covered by the IHA, Atlantic
Shores would report the incident to the NMFS OPR Permits and
Conservation Division and the NMFS New England/Mid-Atlantic Stranding
Coordinator as soon as feasible. The report would include the following
information:
Time, date, and location (latitude/longitude) of the
incident;
Species identification (if known) or description of the
animal(s) involved;
Vessel's speed during and leading up to the incident;
Vessel's course/heading and what operations were being
conducted (if applicable);
Status of all sound sources in use;
Description of avoidance measures/requirements that were
in place at the time of the strike and what additional measures were
taken, if any, to avoid strike;
Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, visibility) immediately preceding the
strike;
Estimated size and length of animal that was struck;
Description of the behavior of the marine mammal
immediately preceding and following the strike;
If available, description of the presence and behavior of
any other marine mammals immediately preceding the strike;
Estimated fate of the animal (e.g., dead, injured but
alive, injured and moving, blood or tissue observed in the water,
status unknown, disappeared); and
To the extent practicable, photographs or video footage of
the animal(s).
Negligible Impact Analysis and Determination
NMFS has defined negligible impact as an impact resulting from the
specified activity that cannot be reasonably expected to, and is not
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
``taken'' through harassment, NMFS considers other factors, such as the
likely nature of any responses (e.g., intensity, duration), the context
of any responses (e.g., critical reproductive time or location,
migration), as well as effects on habitat, and the likely effectiveness
of the mitigation. We also assess the number, intensity, and context of
estimated takes by evaluating this information relative to population
status. Consistent with the 1989 preamble for NMFS's implementing
regulations (54 FR 40338; September 29, 1989), the impacts from other
past and ongoing anthropogenic activities are incorporated into this
analysis via their impacts on the environmental baseline (e.g., as
reflected in the regulatory status of the species, population size and
growth rate where known, ongoing sources of human-caused mortality, or
ambient noise levels).
To avoid repetition, our analysis applies to all the species listed
in Table 2, given that NMFS expects the anticipated effects of the
proposed survey to be similar in nature.
NMFS does not anticipate that serious injury or mortality would
occur as a result of Atlantic Shores's proposed survey, even in the
absence of proposed mitigation, thus the proposed authorization does
not authorize any serious injury or mortality. As discussed in the
Potential Effects of Specified Activities on Marine Mammals and their
Habitat section, non-auditory physical effects and vessel strike are
not expected to occur. Additionally and as discussed previously, given
the nature of activity and sounds sources used and especially in
consideration of the required mitigation, Level A harassment is neither
anticipated nor authorized. We expect that all potential takes would be
in the form of short-term Level B behavioral harassment in the form of
temporary avoidance of the area, reactions that are considered to be of
low severity and with no lasting biological consequences (e.g.,
Southall et al., 2007).
Effects on individuals that are taken by Level B harassment, on the
basis of reports in the literature as well as monitoring from other
similar activities, will likely be limited to reactions such as
increased swimming speeds, increased surfacing time, or decreased
foraging (if such activity were occurring) (e.g., Thorson and Reyff,
2006; HDR, Inc., 2012; Lerma, 2014). Most likely, individuals will
simply move away from the sound source and temporarily avoid the area
where the survey is occurring. We expect that any avoidance of the
survey area by marine mammals would be temporary in nature and that any
marine mammals that avoid the survey area during the survey activities
would not be permanently displaced. Even repeated Level B harassment of
some small subset of an overall stock is unlikely to result in any
significant realized decrease in viability for the affected
individuals, and thus would not result in any adverse impact to the
stock as a whole. Instances of more severe behavioral harassment are
expected to be minimized by proposed mitigation and monitoring
measures.
In addition to being temporary and short in overall duration, the
acoustic footprint of the proposed survey is small relative to the
overall distribution of the animals in the area and their use of the
area. Feeding behavior is not likely to be significantly impacted. Prey
species are mobile and are broadly distributed throughout the project
area; therefore, marine mammals that may be
[[Page 7949]]
temporarily displaced during survey activities are expected to be able
to resume foraging once they have moved away from areas with disturbing
levels of underwater noise. Because of the temporary nature of the
disturbance and the availability of similar habitat and resources in
the surrounding area, the impacts to marine mammals and the food
sources that they utilize are not expected to cause significant or
long-term consequences for individual marine mammals or their
populations.
There are no rookeries, mating or calving grounds known to be
biologically important to marine mammals within the proposed survey
area and there are no feeding areas known to be biologically important
to marine mammals within the proposed survey area. There is no
designated critical habitat for any ESA-listed marine mammals in the
proposed survey area. The proposed survey area overlaps a portion of a
biologically important migratory area for North Atlantic right whales
(effective March-April and November-December) that extends from
Massachusetts to Florida (LaBrecque, et al., 2015). Off the coasts of
Delaware and Maryland, this biologically important migratory area
extends from the coast to beyond the shelf break. Due to the fact that
that the proposed survey is temporary and the spatial extent of sound
produced by the survey would very small relative to the spatial extent
of the available migratory habitat in the area, right whale migration
is not expected to be impacted by the proposed survey.
As described above, North Atlantic right, humpback, and minke
whales, and gray and harbor seals are experiencing ongoing UMEs. For
North Atlantic right whales, as described above, no injury as a result
of the proposed project is expected or proposed for authorization, and
Level B harassment takes of right whales are expected to be in the form
of avoidance of the immediate area of the proposed survey. In addition,
the number of takes proposed for authorization above the Level B
harassment threshold are relatively low (i.e., 18), and the take
numbers proposed for authorization do not account for the proposed
mitigation measures, which would require shutdown of all survey
equipment upon observation of a right whale prior to their entering the
zone that would be ensonified above the Level B harassment threshold.
As no injury or mortality is expected or proposed for authorization,
and Level B harassment of North Atlantic right whales will be reduced
to the level of least practicable adverse impact through use of
proposed mitigation measures, the proposed authorized takes of right
whales would not exacerbate or compound the ongoing UME in any way.
Similarly, no injury or mortality is expected or proposed for
authorization for any of the other species with UMEs, Level B
harassment will be reduced to the level of least practicable adverse
impact through use of proposed mitigation measures, and the proposed
authorized takes would not exacerbate or compound the ongoing UMEs. For
minke whales, although the ongoing UME is under investigation (as
occurs for all UMEs), this event does not provide cause for concern
regarding population level impacts, as the likely population abundance
is greater than 20,000 whales. Even though the PBR value is based on an
abundance for U.S. waters that is negatively biased and a small
fraction of the true population abundance, annual M/SI does not exceed
the calculated PBR value for minke whales. With regard to humpback
whales, the UME does not yet provide cause for concern regarding
population-level impacts. Despite the UME, the relevant population of
humpback whales (the West Indies breeding population, or distinct
population segment (DPS)) remains healthy. The West Indies DPS, which
consists of the whales whose breeding range includes the Atlantic
margin of the Antilles from Cuba to northern Venezuela, and whose
feeding range primarily includes the Gulf of Maine, eastern Canada, and
western Greenland, was delisted. The status review identified harmful
algal blooms, vessel collisions, and fishing gear entanglements as
relevant threats for this DPS, but noted that all other threats are
considered likely to have no or minor impact on population size or the
growth rate of this DPS (Bettridge et al., 2015). As described in
Bettridge et al. (2015), the West Indies DPS has a substantial
population size (i.e., approximately 10,000; Stevick et al., 2003;
Smith et al., 1999; Bettridge et al., 2015), and appears to be
experiencing consistent growth. With regard to gray and harbor seals,
although the ongoing UME is under investigation, the UME does not yet
provide cause for concern regarding population-level impacts to any of
these stocks. For harbor seals, the population abundance is over 75,000
and annual M/SI (345) is well below PBR (2,006) (Hayes et al., 2018).
For gray seals, the population abundance in the United States is over
27,000, with an estimated abundance including seals in Canada of
approximately 505,000, and abundance is likely increasing in the U.S.
Atlantic EEZ as well as in Canada (Hayes et al., 2018).
The proposed mitigation measures are expected to reduce the number
and/or severity of takes by (1) giving animals the opportunity to move
away from the sound source before HRG survey equipment reaches full
energy; (2) preventing animals from being exposed to sound levels that
may otherwise result in injury or more severe behavioral responses.
Additional vessel strike avoidance requirements will further mitigate
potential impacts to marine mammals during vessel transit to and within
the survey area.
NMFS concludes that exposures to marine mammal species and stocks
due to Atlantic Shores's proposed survey would result in only short-
term (temporary and short in duration) effects to individuals exposed.
Marine mammals may temporarily avoid the immediate area, but are not
expected to permanently abandon the area. Major shifts in habitat use,
distribution, or foraging success are not expected. NMFS does not
anticipate the proposed take estimates to impact annual rates of
recruitment or survival.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
this activity are not expected to adversely affect the species or stock
through effects on annual rates of recruitment or survival:
No mortality, serious injury, or Level A harassment is
anticipated or authorized;
The anticipated impacts of the proposed activity on marine
mammals would primarily be in the form of temporary behavioral changes
due to avoidance of the area around the survey vessel;
The availability of alternate areas of similar habitat
value (for foraging, etc.) for marine mammals that may temporarily
vacate the survey area during the proposed survey to avoid exposure to
sounds from the activity;
The proposed project area does not contain known areas of
significance for mating or calving;
Effects on species that serve as prey species for marine
mammals from the proposed survey would be minor and temporary and would
not be expected to reduce the availability of prey or to affect marine
mammal feeding;
The proposed mitigation measures, including visual and
acoustic monitoring, exclusion zones, and shutdown measures, are
expected to minimize potential impacts to marine mammals.
Based on the analysis contained herein of the likely effects of the
[[Page 7950]]
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS preliminarily finds that the total marine
mammal take from the proposed activity will have a negligible impact on
all affected marine mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. Additionally, other qualitative
factors may be considered in the analysis, such as the temporal or
spatial scale of the activities.
We propose to authorize incidental take of 16 marine mammal stocks.
The total amount of taking proposed for authorization is less than 17
percent for one of these stocks, and less than 9 percent for all
remaining stocks (Table 7), which we consider to be relatively small
percentages and we preliminarily find are small numbers of marine
mammals relative to the estimated overall population abundances for
those stocks.
Based on the analysis contained herein of the proposed activity
(including the proposed mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS preliminarily finds that small
numbers of marine mammals will be taken relative to the population size
of all affected species or stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
determined that the total taking of affected species or stocks would
not have an unmitigable adverse impact on the availability of such
species or stocks for taking for subsistence purposes.
Endangered Species Act
Section 7(a)(2) of the Endangered Species Act of 1973 (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 species.
The NMFS Office of Protected Resources is proposing to authorize
the incidental take of four species of marine mammals which are listed
under the ESA: The North Atlantic right, fin, sei, and sperm whale.
BOEM consulted with NMFS GARFO under section 7 of the ESA on commercial
wind lease issuance and site assessment activities on the Atlantic
Outer Continental Shelf in Massachusetts, Rhode Island, New York and
New Jersey Wind Energy Areas. NMFS GARFO issued a Biological Opinion
concluding that these activities may adversely affect but are not
likely to jeopardize the continued existence of the North Atlantic
right, fin, sei and sperm whale. The Biological Opinion can be found
online at: www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable. NMFS
will conclude the ESA section 7 consultation prior to reaching a
determination regarding the proposed issuance of the authorization. If
the IHA is issued, the Biological Opinion may be amended to include an
incidental take statement for these marine mammal species, as
appropriate.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to Atlantic Shores for conducting marine site
characterization activities offshore of New York and New Jersey for a
period of one year, provided the previously mentioned mitigation,
monitoring, and reporting requirements are incorporated. A draft of the
proposed IHA can be found at: www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.
Request for Public Comments
We request comment on our analyses, the proposed authorization, and
any other aspect of this Notice of Proposed IHA for Atlantic Shores'
proposed activity. We also request at this time comment on the
potential Renewal of this proposed IHA as described in the paragraph
below. Please include with your comments any supporting data or
literature citations to help inform decisions on the request for this
IHA or a subsequent Renewal IHA.
On a case-by-case basis, NMFS may issue a one-year Renewal IHA
following notice to the public providing an additional 15 days for
public comments when (1) up to another year of identical or nearly
identical, or nearly identical, activities as described in the
Specified Activities section of this notice is planned or (2) the
activities as described in the Specified Activities section of this
notice would not be completed by the time the IHA expires and a Renewal
would allow for completion of the activities beyond that described in
the Dates and Duration section of this notice, provided all of the
following conditions are met:
A request for renewal is received no later than 60 days
prior to the needed Renewal IHA effective date (recognizing that the
Renewal IHA expiration date cannot extend beyond one year from
expiration of the initial IHA).
The request for renewal must include the following:
(1) An explanation that the activities to be conducted under the
requested Renewal IHA are identical to the activities analyzed under
the initial IHA, are a subset of the activities, or include changes so
minor (e.g., reduction in pile size) that the changes do not affect the
previous analyses, mitigation and monitoring requirements, or take
estimates (with the exception of reducing the type or amount of take).
(2) A preliminary monitoring report showing the results of the
required monitoring to date and an explanation showing that the
monitoring results do not indicate impacts of a scale or nature not
previously analyzed or authorized.
Upon review of the request for Renewal, the status of the
affected species or stocks, and any other pertinent information, NMFS
determines that there are no more than minor changes in the activities,
the mitigation and monitoring measures will remain the same and
appropriate, and the findings in the initial IHA remain valid.
Dated: February 5, 2020.
Donna Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2020-02661 Filed 2-11-20; 8:45 am]
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