[Federal Register Volume 83, Number 155 (Friday, August 10, 2018)]
[Notices]
[Pages 39692-39709]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-17170]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XG170
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to a Marine Geophysical Survey in the
Northwest Atlantic Ocean
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of an incidental harassment authorization.
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SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued an incidental harassment authorization (IHA) to
USGS to incidentally harass, by Level B harassment only, marine mammals
during geophysical survey activities associated with a the USGS's Mid-
Atlantic Resource Imaging Experiment (MATRIX) survey project in the
Northwest Atlantic Ocean.
DATES: This Authorization is effective from August 1, 2018 to July 31,
2019.
FOR FURTHER INFORMATION CONTACT: Jonathan Molineaux, Office of
Protected Resources, NMFS, (301) 427-8401. Electronic copies of the
application and supporting documents, as well as a list of the
references cited in this document, may be obtained online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-research-and-other-activities. In case of problems
accessing these documents, please call the contact listed above.
SUPPLEMENTARY INFORMATION:
Background
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
authorization is provided to the public for review.
An authorization for incidental takings shall be granted if NMFS
finds that the taking will have a negligible impact on the species or
stock(s), will not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (where
relevant), and if the permissible methods of taking and requirements
pertaining to the mitigation, monitoring and reporting of such takings
are set forth.
NMFS has defined ``negligible impact'' in 50 CFR 216.103 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.''
The MMPA states that the term ``take'' means to harass, hunt,
capture, kill or attempt to harass, hunt, capture, or kill any marine
mammal.
Except with respect to certain activities not pertinent here, 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).
Summary of Request
On March 20, 2018, NMFS received a request from USGS for an IHA to
take marine mammals incidental to a marine geophysical survey in the
northwest Atlantic Ocean. On April 11, 2018, we deemed USGS's
application for authorization to be adequate and complete. USGS
requests to take small numbers of 29 species of marine mammals by Level
B harassment only during the survey. Neither USGS nor NMFS expects
serious injury or mortality to result from this activity; and,
therefore, an IHA is appropriate.
Description of Activity
The USGS will conduct a seismic survey aboard the R/V Hugh R.
Sharp, a University National Oceanographic Laboratory (UNOLS) Federal
fleet vessel that is owned and operated by the University of Delaware,
during a cruise up to 22 days long on the northern U.S. Atlantic margin
in August 2018. The seismic survey will take place in water depths
ranging from ~100 meters (m) to 3,500 m, entirely within the U.S.
[[Page 39693]]
Exclusive Economic Zone (EEZ), and acquire ~6 dip lines (roughly
perpendicular to the orientation of the shelf-break) and ~3 strike
lines (roughly parallel to the shelf-break) between about 35 nautical
miles (nmi) south of Hudson Canyon on the north and Cape Hatteras on
the south. In addition, multichannel seismic (MCS) data will be
acquired along some linking/transit/interseismic lines between the main
survey lines. Total data acquisition could be up to ~2,400 kilometers
(km) of trackline.
The purpose of the MATRIX survey is to collect data to constrain
the lateral and vertical distribution of gas hydrates and shallow
natural gas in marine sediments relative to seafloor gas seeps, slope
failures, and geological and erosional features.
The seismic survey's airgun operations are scheduled to occur for
up to 19 days during a cruise that may be as long as 22 days, departing
port on August 8, 2018. Some minor deviation from these dates is
possible, depending on logistics and weather.
The survey will involve only one source vessel, the R/V Hugh R.
Sharp. The source vessel will deploy two to four low-energy Generator-
Injector (GI) airguns (each with a discharge volume of 105 cubic inches
(in\3\)) as an energy source. The GI guns could sometimes be fired in a
mode that gives them a discharge volume of 210 in\3\ each, but only at
water depths greater than 1000 m (See description of Optimal Survey
below for more details).
The Optimal Survey (GG mode) (See Table 1) for the Proposed Action
would acquire the portion of the solid lines in Figure 1 of the IHA
application at water depths greater than 1000 m using the GI-guns in
``GG'' mode. In this mode, the four GI guns would produce a total of
840 in\3\ of air and sonobuoys would be deployed to passively record
data at long distances. When shooting to sonobuoys while in GG mode,
the GI guns will be operated with both chambers releasing air
simultaneously (i.e., ``generator-generator'' or ``GG'' mode). The rest
of the survey, including the portion shallower than 1000 m water depth
on the uppermost slope and the interseismic linking lines (dashed lines
in Figure 1), would be acquired with four GI guns operated in normal
mode (also called GI mode), producing a total of 420 in\3\ of air.
The Base Survey (GI mode) (See Table 1) assumes that all of the
solid lines in Figure 1, as well as all of the interseismic connecting
lines, would be acquired using four GI guns operating in normal mode
(GI mode), producing a total air volume of 420 in\3\. Only a maximum of
half of the interseismic linking lines (dashed lines in Figure 1) would
be acquired. These lines are longer and geometrically more complex at
the deepwater side than near the shelf-break.
Table 1--General Characteristics of Exemplary Survey Scenarios for the Proposed Action
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GI mode (4 x 105 in\3\) GG mode (4 x 210 in\3\)
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Track line Track line
Depth and line type distance (km) Depth and line type distance
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Optimal Survey............ 100-1,000 m water depth ~750 Greater than 1,000 m on ~1,600
on exemplary lines and exemplary lines.
50% of interseismic,
linking lines.
Base Survey............... Exemplary lines plus 50% 2,350 ......................... ..............
of interseismic, linking
lines.
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During the cruise, the USGS would continuously use an echosounder
(EK60/EK80) with 38 kHz transducer at water depths less than ~1,800 m
to locate water column anomalies associated with seafloor seeps
emitting gas bubbles. The 38 kHz transducer would be mounted in the R/V
Sharp's retractable keel and would typically ping 0.5 to 2 Hz with
pings of 0.256 to 1.024 millisecond (m/s) duration. The returned
signals would be detected on an EK60 or EK80 (broadband) transceiver.
Based on past USGS experience with this instrument, it is unlikely to
acquire useful data at water depths greater than 1,800 m, although it
could be used in passive mode at these depths to record broadband
ambient signals in the water column.
A more detailed description of USGS's MATRIX survey is provided in
the Federal Register notice for the proposed IHA (83 FR 25268; May 31,
2018). Since that time, no changes have been made to the planned survey
activities. Therefore, a detailed description is not provided here.
Please refer to that Federal Register notice for the description of the
specific activity.
Comments and Responses
NMFS published a notice of proposed IHA in the Federal Register on
May 31, 2018 (83 FR 25268). During the 30-day public comment period,
NMFS received a comment letter from the Marine Mammal Commission
(Commission). NMFS has posted the comments online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-research-and-other-activities. The following is a
summary of the public comments and NMFS' responses.
Comment 1: After review of the Federal Register notice of the
proposed IHA (83 FR 25268; May 31, 2018) and IHA application for the
USGS MATRIX survey, the Commission inferred that the modeling used by
USGS (Lamont-Doherty Earth Observatory (LDEO)'s Nucleus Model) to
predict Level A and Level B harassment zones applied radial distances
(i.e., slant ranges) and radii indiscriminately. The Commission states
that radial distances were used for metrics based on SELcum
and SPL root-mean-square (SPLrms), and radii were used for
metrics based on SPLpeak, which would yield smaller zones.
As a result, the Commission recommends that NMFS require USGS to
specify why LDEO's Nucleus Model is using radial distances for sound
exposure level (SELcum) and sound pressure level
(SPLrms) metrics and radii for peak sound pressure
(SPLpeak) metrics.
Response: NMFS appreciates the Commission's request for USGS to
explain the specific methodology LDEO's Nucleus Model uses to determine
harassment zones. After consulting with LDEO, USGS has clarified that
two different methods for estimating distance are not being used. In
order to calculate harassment zones, LDEO uses the maximum radial
distance at depth which it vertically projects from that radial
distance back to the surface. This provides a horizontal radius from
the source.
Comment 2: The Commission recommends NMFS provide
[[Page 39694]]
justification for why it believes that LDEO's use of the Nucleus source
model, which does not provide data above 2.5 kHz, is appropriate for
determining the extents of the Level A harassment zones for mid-
frequency and high-frequency cetaceans.
Response: Few broadband calibration studies are available to
support the modeling of airgun spectra above 3 kHz (e.g., Tolstoy et
al. 2004; Breitzke et al. 2008; Tolstoy et al. 2009). Measurements
available indicate that most of the sound produced by airguns is below
1 kHz (i.e., spectral levels drop off continuously above 1 kHz).
Despite JASCO's AASM model predicting acoustic signatures of
seismic airgun arrays up to 25 kHz, often their transmission loss
calculations do not directly use these data to account for frequencies
above 5 kHz because it is computationally intensive (Zeddies et al.
2015). While NMFS agrees that the spectral levels above 3 kHz should
not necessarily be assumed zero, better data are needed to evaluate if
and how airguns at these frequencies are significantly contributing to
noise-induced hearing loss for these two marine mammal hearing groups.
For both MF and HF cetaceans, the TTS onset impulsive thresholds
NMFS currently relies upon are derived directly from individual exposed
to seismic sources (Finneran et al. 2002; Lucke et al. 2009). A more
recent TTS study on harbor porpoises exposed to multiple airgun shots
further supports the current TTS onset thresholds used to evaluate
impulsive sources (Kastelein et al. 2017).
The available TTS onset data do not indicate that airguns are
contributing significantly to noise-induced hearing loss at higher
frequencies in these two hearing groups. Specifically, Lucke et al.
(2009) measured harbor porpoise hearing at 4, 32, and 100 kHz after
exposure to a single airgun shot, with TTS onset only occurring at 4
kHz. Similarly, Kastelein et al. (2017) measured a ~4.4 dB threshold
shift only at 4 kHz, with hearing tested up to 8 kHz, for a harbor
porpoise exposed to multiple airgun shots. Finally, Finneran et al.
(2015) exposed bottlenose dolphins to multiple airgun shots and
measured hearing thresholds up to 64 kHz, without measurable TTS onset
observed. All these studies had measurements demonstrating spectral
levels above 3 kHz for their airgun sources. For these reasons, NMFS
believes that LDEO's use of the Nucleus source model is appropriate.
NMFS appreciates the Commission's interest in this matter and will
continue to evaluate the available information regarding spectral
levels of airgun signals above 3 kHz.
Comment 3. The Commission recommends that NMFS require USGS, in
collaboration with LDEO, to re-estimate the proposed Level A and B
harassment zones and associated takes of marine mammals using (1) both
operational (including number/type/spacing of airguns, tow depth,
source level/operating pressure, operational volume) and site-specific
environmental (including sound speed profiles, bathymetry, and sediment
characteristics at a minimum) parameters, (2) a comprehensive source
model (e.g., Gundalf Optimizer or AASM) and (3) an appropriate sound
propagation model. Specifically, the Commission reiterates its belief
that LDEO should be using the ray-tracing sound propagation model
BELLHOP rather than the MATLAB code currently in use.
Response: USGS's application (USGS, 2018) and the Federal Register
notice of the proposed IHA (83 FR 25268; May 31, 2018) describe the
applicant's approach to modeling Level A and Level B harassment zones.
The model LDEO currently uses does not allow for the consideration of
site-specific environmental parameters as recommended by the
Commission.
In summary, LDEO acquired field measurements for several array
configurations at shallow, intermediate, and deep-water depths during
acoustic verification studies conducted in the northern Gulf of Mexico
(Tolstoy et al., 2009). Based on the empirical data from those studies,
LDEO developed a sound propagation modeling approach that predicts
received sound levels as a function of distance from a particular
airgun array configuration in deep water. For this survey, LDEO modeled
Level A and Level B harassment zones based on the empirically-derived
measurements from the Gulf of Mexico calibration survey (Appendix H of
NSF-USGS 2011). LDEO used the deep-water radii obtained from model
results down to a maximum water depth of 2,000 m (Figure 2 and 3 in
Appendix H of NSF-USGS 2011).
In 2015, LDEO explored the question of whether the Gulf of Mexico
calibration data described above adequately informs the model to
predict harassment isopleths in other areas by conducting a
retrospective sound power analysis of one of the lines acquired during
LDEO's seismic survey offshore New Jersey in 2014 (Crone, 2015). NMFS
presented a comparison of the predicted radii (i.e., modeled exclusion
zones) with radii based on in situ measurements (i.e., the upper bound
[95th percentile] of the cross-line prediction) in a previous notice of
an IHA issued for LDEO (see 80 FR 27635, May 14, 2015, Table 1).
Briefly, the analysis presented in Crone (2015), specific to the survey
site offshore New Jersey, confirmed that in-situ, site-specific
measurements and estimates of 160 decibel (dB) and 180 dB isopleths
collected by the hydrophone streamer of the R/V Marcus Langseth in
shallow water were smaller than the modeled (i.e., predicted) zones for
two seismic surveys conducted offshore New Jersey in shallow water in
2014 and 2015. In that particular case, Crone's (2015) results showed
that LDEO's modeled 180 dB and 160 dB zones were approximately 28
percent and 33 percent larger respectively, than the in-situ, site-
specific measurements, thus confirming that LDEO's model was
conservative in that case.
The following is a summary of two additional analyses of in-situ
data that support LDEO's use of the modeled Level A and Level B
harassment zones in this particular case. In 2010, LDEO assessed the
accuracy of their modeling approach by comparing the sound levels of
the field measurements acquired in the Gulf of Mexico study to their
model predictions (Diebold et al., 2010). They reported that the
observed sound levels from the field measurements fell almost entirely
below the predicted harassment radii curve for deep water (i.e.,
greater than 1,000 m; 3,280.8 ft) (Diebold et al., 2010). In 2012, LDEO
used a similar process to model distances to isopleths corresponding to
Level A and Level B harassment thresholds for a shallow-water seismic
survey in the northeast Pacific Ocean off Washington State. LDEO
conducted the shallow-water survey using a 6,600 in\3\ airgun
configuration aboard the R/V Marcus Langseth and recorded the received
sound levels on both the shelf and slope using the Langseth's 8 km
hydrophone streamer. Crone et al. (2014) analyzed those received sound
levels from the 2012 survey and confirmed that in-situ, site specific
measurements and estimates of the 160 dB and 180 dB isopleths collected
by the Langseth's hydrophone streamer in shallow water were two to
three times smaller than LDEO's modeling approach had predicted. While
the results confirmed the role of bathymetry in sound propagation,
Crone et al. (2014) were also able to confirm that the empirical
measurements from the Gulf of Mexico calibration survey (the same
measurements used to inform LDEO's modeling approach for the planned
surveys in the northwest Atlantic
[[Page 39695]]
Ocean) overestimated the size of the exclusion and buffer zones for the
shallow-water 2012 survey off Washington State and were thus
precautionary, in that particular case.
NMFS continues to work with LDEO to address the issue of
incorporating site-specific information for future authorizations for
seismic surveys. However, LDEO's current modeling approach (supported
by the three studies discussed previously) represents the best
available information for NMFS to reach determinations for this IHA. As
described earlier, the comparisons of LDEO's model results and the
field data collected at multiple locations (i.e., the Gulf of Mexico,
offshore Washington State, and offshore New Jersey) illustrate a degree
of conservativeness built into LDEO's model for deep water, which NMFS
expects to offset some of the limitations of the model to capture the
variability resulting from site-specific factors. Based upon the best
available information (i.e., the referenced studies, two of which are
peer-reviewed, discussed in this response), NMFS finds that the Level A
and Level B harassment zone calculations are reasonable and appropriate
for use in this particular IHA.
LDEO has conveyed to NMFS that additional modeling efforts to
refine the process and conduct comparative analysis may be possible
with the availability of research funds and other resources. Obtaining
research funds is typically accomplished through a competitive process,
including those submitted to U.S. Federal agencies. The use of models
for calculating Level A and Level B harassment zones and for developing
take estimates is not a requirement of the MMPA incidental take
authorization process. Further, NMFS does not provide specific guidance
on model parameters nor prescribe a specific model for applicants as
part of the MMPA incidental take authorization process at this time,
although we do review methods to ensure that they are adequate for
reasonable prediction of take. There is a level of variability not only
with parameters in the models, but also the uncertainty associated with
data used in models, and therefore, the quality of the model results
submitted by applicants. NMFS considers this variability when
evaluating applications and the take estimates and mitigation measures
that the model informs. NMFS takes into consideration the model used,
and its results, in determining the potential impacts to marine
mammals; however, it is just one component of the analysis during the
MMPA authorization process as NMFS also takes into consideration other
factors associated with the activity (e.g., geographic location,
duration of activities, context, sound source intensity, etc.).
Comment 4: The Commission recommends that NMFS require USGS to
archive, analyze, and compare the in-situ data collected by the
sonobuoys and hydrophone streamer to LDEO's modeling results for the
extents of the Level A and B harassment zones based on the various
airgun configurations and water depths to be surveyed and provide the
data and results to NMFS.
Response: NMFS will suggest that the USGS use its collected data to
both analyze and compare with LDEO's modeling results and share with
NMFS. However, NMFS does not deem it necessary to require USGS to use
the in-situ data it collects from the sonobuoys and hydrophone streamer
it deploys during its cruise. As stated in the response to Comment 2,
NMFS continues to work with LDEO to address the issue of incorporating
site-specific information for future authorizations for seismic
surveys. Nevertheless, LDEO's Nucleus model has shown to be
conservative when compared to in-situ, site specific measurements and
estimates (Crone 2015). Therefore, NMFS asserts that the use of the
Nucleus source model in its current state is appropriate.
Comment 5: The Commission recommends that NMFS ensure that USGS
calculated the numbers of takes appropriately based on the line-
kilometers to be surveyed in each of the 11 tracklines and the number
of days it would take to survey each location, the associated
ensonified areas, and site-specific densities--species-specific takes
from each of the 11 locations should be summed to yield the total
numbers of takes for each species.
Response: The number of days are factored into the take estimates.
To calculate take, USGS used 10 km x 10 km density grid blocks taken
from Roberts et al. (2016) which were intersected with two different
buffer zones. One buffer is equivalent to the largest Level A
harassment zone and the other is equal to both the largest Level A
harassment zone and Level B harassment zone (for the Optimal Survey)
combined. As a result, the modeling method derived a take total for
each 10 km x 10 km block the R/V Sharp will survey. Take totals for
each block were each added (rounded at the end) to come up with the
take estimates for each species. Due to the short duration (a few hours
at most) that the R/V Sharp will conduct seismic operations in each 10
km x 10 km survey block, the number of days (1 day per block) is
factored into the take estimates.
Comment 6: The Commission recommends that NMFS require USGS to
provide in all future applications all relevant information regarding
line-kilometers to be surveyed and days necessary to survey each
location based on a presumed survey speed, associated ensonified areas,
site-specific densities, and any other assumptions (including the
assumed 25-percent contingency).
Response: NMFS will continue to request as much information from
applicants as necessary to determine if their take methodology is
scientifically accurate. After NMFS's request, USGS provided NMFS and
the Commission with more data to analyze the method used to estimate
take during the survey. In reviewing these data with the density
estimates provided in Roberts et al. (2016), NMFS determined that the
methodology used for take calculation in the IHA application is
appropriate. In all, USGS provided NMFS with enough information to
effectively assess the generated take estimates. For future surveys,
USGS will work to provide a technical guidance document that will
better detail its take methodology using Geographic Information Systems
(GIS) software.
Comment 7: The Commission recommends that NMFS share its rounding
criteria.
Response: On June 27, 2018, NMFS provided the Commission with
internal guidance on rounding and the consideration of additional
factors in take estimation.
Comment 8: The Commission recommends that NMFS condition the
authorization to limit USGS's use of the echosounder during transits to
and from the survey area except during calibration. In addition, the
Commission recommends NMFS advise USGS that it needs to obtain
additional authorization to take marine mammals while using an
echosounder to collect gas hydrate data during transits to and from the
survey area.
Response: As stated in the IHA application, marine mammals would
have to be either very close and remain near the sound source for many
repeated pings to receive overall exposures sufficient to cause TTS
onset (Lucke et al. 2009; Finneran and Schlundt 2010) from the
fisheries echosounder. The echosounder used by USGS during the MATRIX
survey will only transmit conically downward in a maximum 10 degree
cone. Based on modeling by the U.S. Geological Survey, the area
ensonified at greater than 160 dB re: 1 [mu]Pa (rms) is 0.0407 square
kilometers (0.0119 square nautical
[[Page 39696]]
miles), corresponding to a maximum of approximately 72 meters (236.2
feet) athwartship and approximately 650 meters (2,132.6 feet) below the
research vessel (See Figure 18 of USGS 2018). This, combined with the
vessel strike avoidance measures stipulated in section 4(f) of the IHA
for the USGS MATRIX survey allows NMFS to concur that the minimal use
of a scientific echosounder during transits is not reasonably likely to
result in the incidental taking of marine mammals pursuant to the MMPA.
Description of Marine Mammals in the Area of Specified Activities
A detailed description of the species likely to be affected by
USGS's geophysical survey, including brief introductions to the species
and relevant stocks as well as available information regarding
population trends and threats, and information regarding local
occurrence, were provided in the Federal Register notice for the
proposed IHA (83 FR 25268; May 31, 2018); since that time, we are not
aware of any changes in the status of these species and stocks;
therefore, detailed descriptions are not provided here. Please refer to
that Federal Register notice for these descriptions. Please also refer
to NMFS' website (https://www.fisheries.noaa.gov/topic/population-assessments/marine-mammals) for generalized species accounts. All
species that could potentially occur in the planned survey area are
included in Table 2. However, density estimates in Roberts et al.
(2016) present very low density estimates within the proposed action
area during the month of August for north Atlantic right whale, harbor
porpoise, minke whale, Bryde's whale, blue whale, and white-beaked
dolphin (See Table 6 of IHA Application). This, in combination with the
short length of the cruise and low level airguns provide reasonable
evidence that take authorization is not necessary, nor should they be
authorized for these species. Species with expected take are discussed
below.
Table 2--Marine Mammals That Could Occur in the Project Area
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NMFS stock
ESA/MMPA abundance (CV, Annual
Common name Scientific name Stock status; Nmin, most recent Predicted abundance PBR M/SI
strategic (Y/ abundance survey) (CV) \5\ \3\
N) \1\ \2\
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Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
Family Balaenidae
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North Atlantic right whale...... Eubalaena glacialis Western North E/D; Y 458 (n/a; 455; n/a) 334 (0.25)........... 1.4 36
Atlantic (WNA).
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Family Balaenopteridae (rorquals)
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Humpback whale.................. Megaptera Gulf of Maine...... -; N 335 (.42; 239; 1,637 (0.07)......... 3.7 8.5
novaeangliae 2012).
novaeangliae.
Minke whale..................... Balaenoptera Canadian East Coast -; N 2,591 (0.81; 1,425; 2,112 (0.05)......... 14 9
acutorostrata 2011).
acutorostrata.
Bryde's whale................... B. edeni brydei.... None defined \4\... -; n/a n/a................ 7 (0.58)............. n/a n/a
Sei whale....................... B. borealis Nova Scotia........ E/D; Y 357 (0.52; 236; 98 (0.25)............ 0.5 0.8
borealis. 2011).
Fin whale....................... B. physalus WNA................ E/D; Y 1,618 (0.33; 1,234; 4,633 (0.08)......... 2.5 2.65
physalus. 2011).
Blue whale...................... B. musculus WNA................ E/D; Y Unknown (n/a; 440; 11 (0.41)............ 0.9 Unk
musculus. n/a).
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Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
Family Physeteridae
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Sperm whale..................... Physeter North Atlantic..... E/D; Y 2,288 (0.28; 1,815; 5,353 (0.12)......... 3.6 0.8
macrocephalus. 2011).
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Family Kogiidae
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Pygmy sperm whale............... Kogia breviceps.... WNA................ -; N 3,785 (0.47; 2,598; 678 (0.23)........... 21 3.5
2011).
Dwarf sperm whale............... K. sima............ WNA................ -; N
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Family Ziphiidae (beaked whales)
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Cuvier's beaked whale........... Ziphius cavirostris WNA................ -; N 6,532 (0.32; 5,021; 14,491(0.17)......... 50 0.4
2011).
Gervais beaked whale............ Mesoplodon WNA................ -; N 7,092 (0.54; 4,632; ..................... 46 0.2
europaeus. 2011).
Blainville's beaked whale....... M. densirostris.... WNA................ -; N
Sowerby's beaked whale.......... M. bidens.......... WNA................ -; N
True's beaked whale............. M. mirus........... WNA................ -; N
Northern bottlenose whale....... Hyperoodon WNA................ -; N Unknown............ 90 (0.63)............ Undet. 0
ampullatus.
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Family Delphinidae
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Rough-toothed dolphin........... Steno bredanensis.. WNA................ -; N 271 (1.0; 134; 532 (0.36)........... 1.3 0
2011).
Common bottlenose dolphin....... Tursiops truncatus WNA Offshore....... -; N 77,532 (0.40; 97,476 (0.06)........ 561 39.4
truncatus. 56,053; 2011).
Clymene dolphin................. Stenella clymene... WNA................ -; N Unknown............ 12,515 (0.56)........ Undet. 0
Atlantic spotted dolphin........ S. frontalis....... WNA................ -; N 44,715 (0.43; 55,436 (0.32)........ 316 0
31,610; 2011).
Pantropical spotted dolphin..... S. attenuata WNA................ -; N 3,333 (0.91; 1,733; 4,436 (0.33)......... 17 0
attenuata. 2011).
Spinner dolphin................. S. longirostris WNA................ -; N Unknown............ 262 (0.93)........... Undet. 0
longirostris.
Striped dolphin................. S. coeruleoalba.... WNA................ -; N 54,807 (0.3; 75,657 (0.21)........ 428 0
42,804; 2011).
Short-beaked common dolphin..... Delphinus delphis WNA................ -; N 70,184 (0.28; 86,098 (0.12)........ 557 437
delphis. 55,690; 2011).
Fraser's dolphin................ Lagenodelphis hosei WNA................ -; N Unknown............ 492 (0.76)........... Undet. 0
Atlantic white-sided dolphin.... Lagenorhynchus WNA................ -; N 48,819 (0.61; 37,180 (0.07)........ 304 57
acutus. 30,403; 2011).
[[Page 39697]]
Risso's dolphin................. Grampus griseus.... WNA................ -; N 18,250 (0.46; 7,732 (0.09)......... 126 43.2
12,619; 2011).
Melon-headed whale.............. Peponocephala WNA................ -; N Unknown............ 1,175 (0.50)......... Undet. 0
electra.
Pygmy killer whale.............. Feresa attenuata... WNA................ -; N Unknown............ N/A.................. Undet. 0
False killer whale.............. Pseudorca WNA................ -; Y 442 (1.06; 212; 95 (0.84)............ 2.1 Unk.
crassidens. 2011).
Killer whale.................... Orcinus orca....... WNA................ -; N Unknown............ 11................... Undet. 0
Short-finned pilot whale........ Globicephala WNA................ -; Y 21,515 (0.37; 18,977 (0.11)........ 159 192
macrorhynchus. 15,913; 2011).
Long-finned pilot whale......... G. melas melas..... WNA................ -; Y 5,636 (0.63; 3,464; ..................... 35 38
2011).
White-beaked dolphin............ Lagenorhynchus WNA................ -; N 2,003 (0.94; 1,023; 39 (0.42)............ 10 0
albirostris. 2007).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocoenidae (porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor porpoise................. Phocoena phocoena Gulf of Maine/Bay -; N 79,833 (0.32; 45,089 (0.12)........ 706 307
phocoena. of Fundy. 61,415; 2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
stock abundance.
\3\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated
with estimated mortality due to commercial fisheries is presented in some cases.
\4\ Bryde's whales are occasionally reported off the southeastern U.S. and southern West Indies. NMFS defines and manages a stock of Bryde's whales
believed to be resident in the northern Gulf of Mexico, but does not define a separate stock in the Atlantic Ocean.
\5\ Predicted mean abundance derived from Roberts et al. (2016).
Note--Italicized species in the ``Common Name ``column are not authorized for take.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The effect of stressors associated with the specified activities
(e.g., seismic airguns) has the potential to result in behavioral
harassment of marine mammals in the vicinity of the action areas. The
Federal Register notice for the proposed IHA (83 FR 25268; May 31,
2018) included a discussion of the effects of such disturbance on
marine mammals, therefore that information is not repeated here.
NMFS described potential impacts to marine mammal habitat in detail
in our Federal Register notice of proposed authorization (83 FR 25268;
May 31, 2018). In summary, due to the short duration of the activities
and the relatively small area of the habitat that the survey covers,
the impacts to marine mammal habitat are not expected to cause
significant or long-term negative consequences for individual marine
mammals or their populations.
Estimated Take
This section provides an estimate of the number of incidental takes
for authorization through this IHA, which will inform both NMFS's
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 will be by Level B harassment only, in the form of
disruption of behavioral patterns for individual marine mammals
resulting from exposure to airguns. Based on the nature of the
activity, the cryptic behavior and low density for Kogia spp. (the only
high-frequency cetacean authorized for take) within the action areas,
and the anticipated effectiveness of the mitigation measures (i.e.,
shutdown and a minimum vessel distance of 100 m from large whales--
discussed in detail below in the Mitigation section), Level A
harassment is neither anticipated nor authorized. As described
previously, no mortality is anticipated or authorized for this
activity. Below we describe how the take is estimated.
Described in the most basic way, 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. Below, we describe these
components in more detail and present the 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 will be reasonably expected to be
behaviorally harassed (equated to Level B harassment) or to incur PTS
of some degree (equated to Level A harassment).
Level B Harassment for non-explosive sources--Though significantly
driven by received level, the onset of behavioral disturbance from
anthropogenic noise exposure is also informed to varying degrees by
other factors related to the source (e.g., frequency, predictability,
duty cycle), the environment (e.g., bathymetry), and the receiving
animals (hearing, motivation, experience, demography, behavioral
context) and can be difficult to predict (Southall et al., 2007,
Ellison et al., 2012). Based on what the available science indicates
and the practical need to use a threshold based on a factor that is
both predictable and measurable for most activities, NMFS uses a
generalized acoustic threshold based on received level to
[[Page 39698]]
estimate the onset of behavioral harassment. NMFS predicts that marine
mammals are likely to be behaviorally harassed in a manner we consider
Level B harassment when exposed to underwater anthropogenic noise above
received levels of 120 decibels (dB) re 1 micro pascal ([mu]Pa) root
mean square (rms) for continuous (e.g., vibratory pile-driving,
drilling) and above 160 dB re 1 [mu]Pa (rms) for non-explosive
impulsive (e.g., seismic airguns) sources. USGS's activity includes the
use of impulsive seismic sources. Therefore, the 160 dB re 1 [mu]Pa
(rms) criteria is applicable for analysis of Level B harassment.
Level A harassment for non-explosive sources--NMFS' Technical
Guidance for Assessing the Effects of Anthropogenic Sound on Marine
Mammal Hearing (Technical Guidance, 2016) 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).
As described above, USGS's activity includes the use of intermittent
and impulsive seismic sources. These thresholds are provided in the
table below. The references, analysis, and methodology used in the
development of the thresholds are described in NMFS 2016 Technical
Guidance, which may be accessed at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 3--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 [mu]Pa, and cumulative sound exposure level (LE) has
a reference value of 1[mu]Pa2s. 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
The survey will entail the use of a 4-airgun array with a total
maximum discharge of 840 cubic inches (in\3\) for operations that occur
at water depths greater than 1,000 m and 420 in\3\ for operations that
occur at water depths of 1,000 m or less with at a tow depth of 3 m.
The distances to the predicted isopleths corresponding to the threshold
for Level B harassment (160 dB re 1 [mu]Pa) were calculated for both
array configurations based on results of modeling performed by LDEO
using the Nucleus Model. Received sound levels were predicted by LDEO's
model (Diebold et al., 2010) as a function of distance from the airgun
array. The LDEO modeling approach uses ray tracing for the direct wave
traveling from the array to the receiver and its associated source
ghost (reflection at the air-water interface in the vicinity of the
array), in a constant-velocity half-space (infinite homogeneous ocean
layer unbounded by a seafloor). In addition, propagation measurements
of pulses from a 36-airgun array at a tow depth of 6 m have been
reported in deep water (~1,600 m), intermediate water depth on the
slope (~600-1,100 m), and shallow water (~50 m) in the Gulf of Mexico
in 2007-2008 (Tolstoy et al., 2009; Diebold et al., 2010). The
estimated distances to Level B harassment isopleths for the two
configurations of the R/V Hugh R. Sharp airgun array are shown in Table
4.
Table 4--Modeled Radial Distances [m (km\2\)] From R/V Hugh R. Sharp's Airgun Array to Isopleths Corresponding
to Level B harassment thresholds
----------------------------------------------------------------------------------------------------------------
Predicted RMS
Radii (m)
Source and volume Tow depth (m) Water depth (m) -------------------
160 dB
----------------------------------------------------------------------------------------------------------------
Base Configuration 3 >1,000 1,091 m (3.7
(Configuration 1): Four 105 100-1,000 km\2\) \1\
in\3\ GI-guns. 1,637 m (8.42
km\2\) \2\
GG Configuration(Configuration 3 >1,000 1,244 m (4.86
2): Four 210 in\3\ GI-guns. 100-1,000 km\2\) \1\
1,866 m (10.94
km\2\) \2\
----------------------------------------------------------------------------------------------------------------
\1\ Distance is based on L-DEO model results.
\2\ Distance is based on L-DEO model results with a 1.5 x correction factor between deep and intermediate water
depths.
For modeling of radial distances to predicted isopleths
corresponding to harassment thresholds in deep water (>1,000 m), LDEO
used the deep-water radii for various SELs obtained from LDEO model
results down to a
[[Page 39699]]
maximum water depth of 2,000 m (see Figures 4 and 5 in the IHA
application). LDEO's modeling methodology is described in greater
detail in the IHA application (USGS, 2018) and we refer to the reader
to that document rather than repeating it here.
Predicted distances to Level A harassment isopleths, which vary
based on marine mammal functional hearing groups (Table 3), were
calculated based on modeling performed by LDEO using the Nucleus
software program and the NMFS User Spreadsheet, described below. The
updated acoustic thresholds for impulsive sounds (such as airguns)
contained in the Technical Guidance (NMFS, 2016) were presented as dual
metric acoustic thresholds using both SELcum and peak sound
pressure level metrics. As dual metrics, NMFS considers onset of PTS
(Level A harassment) to have occurred when either one of the two
metrics is exceeded (i.e., metric resulting in the largest isopleth).
The SELcum metric considers both level and duration of
exposure, as well as auditory weighting functions by marine mammal
hearing group. In recognition of the fact that the requirement to
calculate Level A harassment ensonified areas could be more technically
challenging to predict due to the duration component and the use of
weighting functions in the new SELcum thresholds, NMFS
developed an optional User Spreadsheet that includes tools to help
predict a simple isopleth that can be used in conjunction with marine
mammal density or occurrence to facilitate the estimation of take
numbers.
The values for SELcum and peak SPL for the R/V Hugh R.
Sharp airgun array were derived from calculating the modified farfield
signature (Table 5). The farfield signature is often used as a
theoretical representation of the source level. To compute the farfield
signature, the source level is estimated at a large distance below the
array (e.g., 9 km), and this level is back projected mathematically to
a notional distance of 1 m from the array's geometrical center.
However, when the source is an array of multiple airguns separated in
space, the source level from the theoretical farfield signature is not
necessarily the best measurement of the source level that is physically
achieved at the source (Tolstoy et al., 2009). Near the source (at
short ranges, distances <1 km), the pulses of sound pressure from each
individual airgun in the source array do not stack constructively, as
they do for the theoretical farfield signature. The pulses from the
different airguns spread out in time such that the source levels
observed or modeled are the result of the summation of pulses from a
few airguns, not the full array (Tolstoy et al., 2009). At larger
distances, away from the source array center, sound pressure of all the
airguns in the array stack coherently, but not within one time sample,
resulting in smaller source levels than the source level derived from
the farfield signature. Because the farfield signature does not take
into account the array effect near the source and is calculated as a
point source, the modified farfield signature is a more appropriate
measure of the sound source level for distributed sound sources, such
as airgun arrays. Though the array effect is not expected to be as
pronounced in the case of a 4-airgun array as it will be with a larger
airgun array, the modified farfield method is considered more
appropriate than use of the theoretical farfield signature.
In order to more realistically incorporate the Technical Guidance's
weighting functions over the seismic array's full acoustic band,
unweighted spectrum data for the R/V Hugh R. Sharp's airgun array
(modeled in 1 Hz bands) was used to make adjustments (dB) to the
unweighted spectrum levels, by frequency, according to the weighting
functions for each relevant marine mammal hearing group. These
adjusted/weighted spectrum levels were then converted to pressures
([mu]Pa) in order to integrate them over the entire broadband spectrum,
resulting in broadband weighted source levels by hearing group that
could be directly incorporated within the User Spreadsheet (i.e., to
override the Spreadsheet's more simple weighting factor adjustment).
Using the User Spreadsheet's ``safe distance'' methodology for mobile
sources (described by Sivle et al., 2014) with the hearing group-
specific weighted source levels, and inputs assuming spherical
spreading propagation, a source velocity of 2.06 m/second and a shot
interval of 12.15 seconds, potential radial distances to auditory
injury zones were calculated for Peak SPLflat and
SELcum thresholds, for both array configurations. Source
level Inputs to the User Spreadsheet are shown in Table 5 (inputs to
the user spreadsheet also included the source velocity and shot
interval listed above). Outputs from the User Spreadsheet in the form
of estimated distances to Level A harassment isopleths are shown in
Table 6. The larger distance of the dual criteria (SELcum or
Peak SPLflat) is used for estimating takes by Level A
harassment. The weighting functions used are shown in Appendix C of the
IHA application.
Table 5--Modeled Source Levels ** (dB) for the R/V Hugh R. Sharp's Airgun Array
--------------------------------------------------------------------------------------------------------------------------------------------------------
Configuration Configuration Configuration Configuration Configuration Configuration
1 * 4 x 105 1 * 4 x 105 2 * 4 x 210 2 * 4 x 210 3 * 2 x 105 3 * 2 x 105
Functional hearing group cu\3\ SELcum cu\3\ Peak cu\3\ SELcum cu\3\ Peak cu\3\ SELcum cu\3\ Peak
SPLflat SPLflat SPLflat
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low frequency cetaceans (Lpk,flat: 219 dB; LE,LF,24h: 214 239 215 240 208 235
183 dB)................................................
Mid frequency cetaceans (Lpk,flat: 230 dB; LE,MF,24h: 214 N/A 215 N/A 208 234
185 dB)................................................
High frequency cetaceans (Lpk,flat: 202 dB; LE,HF,24h: 214 239 215 240 208 235
155 dB)................................................
--------------------------------------------------------------------------------------------------------------------------------------------------------
* All configurations have the following airgun specifications: 3 m tow depth; 2 m separation in the fore-aft direction; 8.6 m separation in the port
(starboard direction).
**Source Levels were rounded to nearest whole number. See Appendix C of IHA Application for exact value.
Table 6--Modeled Radial Distances [m(m2)] From R/V Hugh R. Sharp's Airgun Array to Isopleths Corresponding to Level A Harassment Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
Configuration 1 4 x
Configuration 1 4 x 105 cu\3\ 3 m tow Configuration 2 4 x Configuration 2 4 Configuration 3 2 Configuration 3 2
Functional hearing group 105 cu\3\ SELcum depth, Peak SPLflat 210 cu\3\ SELcum x 210 cu\3\ Peak x 105 cu\3\ SELcum x 105 cu\3\ Peak
SPLflat SPLflat
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low frequency cetaceans 31 m (3,019 m\2\).. 10.03 m (316 m\2\). 39.5 m (4,902 m\2\) 11.56 m (420 m\2\) 10.6 m (353 m\2\). 6.52 m (134 m\2\)
(Lpk,flat: 219 dB;
LE,LF,24h: 183 dB).
Mid frequency cetaceans 0.................. 0.................. 0.................. 0................. 0................. 1.58 m (8 m\2\)
(Lpk,flat: 230 dB;
LE,MF,24h: 185 dB).
[[Page 39700]]
High frequency cetaceans 0.................. 70.43 m (15743.22 0.1(.03 m\2\)...... 80.50 m (20,358 0................. 42.32 m (5,627
(Lpk,flat: 202 dB; m\2\). m\2\). m\2\)
LE,HF,24h: 155 dB).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note that because of some of the assumptions included in the
methods used, isopleths produced may be overestimates to some degree.
However, these tools offer the best way to predict appropriate
isopleths when more sophisticated 3D modeling methods are not
available, and NMFS continues to develop ways to quantitatively refine
these tools and will qualitatively address the output where
appropriate. For mobile sources, such as this seismic survey, the User
Spreadsheet predicts the closest distance at which a stationary animal
would not incur PTS if the sound source traveled by the animal in a
straight line at a constant speed.
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 best available scientific information was considered
in conducting marine mammal exposure estimates (the basis for
estimating take). For all cetacean species, densities calculated by
Roberts et al. (2016) were used. These represent the most comprehensive
and recent density data available for cetacean species in the survey
area. Roberts et al. (2016) retained 21,946 cetacean sightings for
analysis, omitted 4,786 sightings, and modeled 25 individual species
and 3 multi-species guilds. In order to develop density models for
species, Roberts et al. (2016) used an approach known as density
surface modeling, as seen in DoN (2007) and Roberts et al. (2016). This
couples traditional distance sampling with multivariate regression
modeling to produce density maps predicted from fine-scale
environmental covariates (e.g., Becker et al., 2014).
In addition to the density information provided by Roberts et al.
(2016), best available data on average group sizes taken from sightings
in the western North Atlantic were also used. This is discussed more in
the section below.
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate. To estimate marine
mammal exposures, the USGS used published, quantitative density models
by Roberts et al. (2016) for the Survey Area, which is entirely within
the U.S. EEZ. These models are provided at 10 km x 10 km resolution in
ArcGIS compatible IMG grids on the Duke University cetacean density
website (http://seamap.env.duke.edu/models/Duke-EC-GOM-2015). When
available, the cetacean density models for Month 8 (August) were used.
Otherwise, the generic annual density model was employed. Only a single
density model is provided for the Kogia genus (dwarf and sperm pygmy
whales), beaked whale guild (Blainville's, Cuvier's, Gervais',
Sowerby's, and True's beaked whales), and for pilot whales
(Globicephala spp.).
To determine takes, the USGS combined the Duke density grids with
the zones corresponding to the Level A and Level B harassment
thresholds (See Tables 4 and 6) arrayed on either side of each
exemplary seismic line and linking/interseismic line. The takes by
Level B and Level A harassment for each species in each 10 km x 10 km
block of the IMG density grids were calculated based on the fractional
area of each block intersected by the Level A and Level B harassment
zones for LF, MF, and HF cetaceans. Summing takes along all of the
lines yields the total take for each species for the action for the
Base (Configuration 1) and Optimal (Configuration 2) surveys. The
method also yields take for each survey line individually, allowing
examination of those exemplary lines that will yield the largest or
smallest take. No Level A harassment takes were calculated while using
this method.
As indicated earlier, estimated numbers of individuals potentially
exposed to sound above the Level B harassment threshold are based on
the 160-dB re 1[mu]Pa (rms) criterion for all cetaceans. It is assumed
that marine mammals exposed to airgun sounds that strong could change
their behavior sufficiently to be considered taken by harassment. Table
7 shows the estimates of the number of cetaceans that potentially could
be exposed to >=160 dB re 1 [mu]Pa (rms) during the action for the Base
Survey and the Optimal Survey. The takes in Table 7 represents 25
percent more than the number of takes calculated using the ArcGIS-based
quantitative method devised by the USGS. This was used to account for
potential additional seismic operations that may occur after repeat
coverage of any areas where initial data quality is sub-standard.
Also, as shown in Table 7, rough toothed dolphin, sei whale, and
humpback whale calculated takes were increased to account for the
average size of one group for each species. Takes for rare species of
marine mammals in the action area were also increased to the average
size of one group. Rare species that could be encountered and taken
during the surveys are not presented in Table 7, but are presented in
Table 8. These species were omitted from Table 7 due to low calculated
incidents of potential exposures (i.e., less than the average group
size). As a result, NMFS relied on average group size data to authorize
the take of a single group of these species as a precautionary measure
in case the survey encounters them. This is discussed further below
Table 7.
The calculated takes in Table 7 and 8 also assume that the surveys
will be completed. However, it is unlikely that the entire survey
pattern (exemplary lines plus 50 percent of the interseismic, linking
lines) will be completed given the limitations on ship time, likely
logistical challenges (compressor and GI gun repairs), time spent on
transits and refueling, and the historical problems with weather during
August in the western North Atlantic. The USGS's calculated timelines
indicate that 25 days, including contingency, could be required to
complete the full survey pattern. However, only 22 days or fewer will
be scheduled for this USGS survey. The lines that are actually acquired
will be dependent on weather, strength of the Gulf Stream (affects
ability to tow the streamer in the appropriate geometry), and other
considerations.
[[Page 39701]]
Table 7--Calculated Incidents of Potential Exposure for Level B and Level A Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Optimal survey Max Level B take
Species -------------------------------- for optimal or Take (all Level Take as % of
Level A Level B base surveys +25% B) \6\ pop.\1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low Frequency Cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale................................................. 0 0 0 \5\ 3 <0.1
Sei whale...................................................... 0 1 1 \7\ 3 2.04
Fin whale...................................................... 0 4 5 5 0.1
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mid-Frequency Cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale.................................................... 0 128 161 161 2.9
Cuvier's beaked whale.......................................... 0 \2\ 103 \2\ 128 \2\ 128 <0.1
True's beaked whale............................................ 0
Gervais beaked whale........................................... 0
Sowerby's beaked whale......................................... 0
Blainville's beaked whale...................................... 0
Rough-toothed dolphin.......................................... 0 5 6 \3\ 10 1.9
Common bottlenose dolphin...................................... 0 606 757 757 0.8
Pantropical spotted dolphin.................................... 0 40 50 50 1.1
Atlantic spotted dolphin....................................... 0 1,278 1,598 1,598 2.9
Striped dolphin................................................ 0 1,167 1,459 1,459 1.9
Short-beaked common dolphin.................................... 0 1,296 1,620 1,620 1.9
Risso's dolphin................................................ 0 189 237 237 3
Long-finned pilot whale........................................ 0 \4\ 231 0 \4\ 288 1.5
Short-finned pilot whale....................................... 0 0 0
Clymene's dolphin.............................................. 0 97 0 122 1
--------------------------------------------------------------------------------------------------------------------------------------------------------
High-Frequency Cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pygmy/dwarf sperm whale........................................ 0 7 0 9 0.2
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Based on mean abundance estimates from Roberts et al. (2016).
\2\ Values for density, take number, and percentage of population for authorization are for all beaked whales combined.
\3\ Based on one average group size for rough toothed dolphin (Jefferson 2015).
\4\ Values for density, take number, and percentage of population for authorization are for short-finned and long-finned pilot whales combined.
\5\ Based on one average group size for humpback whales (CETAP 1982). Summer seasonal sightings compiled from the OBIS database (See Figure 6 of IHA
Application) show that humpback whales have been seen in the northern part of the action area during August.
\6\ Values are the same take numbers shown in Table 8 below. Table 8 includes take of rare species discussed below.
\7\ Based on one average group size for sei whale in the western Atlantic (CETAP 1982).
Certain species potentially present in the survey areas are
expected to be encountered only extremely rarely, if at all. Although
Roberts et al. (2016) provide density models for these species (with
the exception of the pygmy killer whale), due to the small numbers of
sightings that underlie these models' predictions we believe it
appropriate to account for the small likelihood that these species will
be encountered by assuming that one group of each of these species
might be encountered once by a given survey. With the exception of the
northern bottlenose whale, none of these species should be considered
cryptic (i.e., difficult to observe when present) versus rare (i.e.,
not likely to be present). Average group size was determined by
considering known sightings in the western North Atlantic (CETAP, 1982;
Hansen et al, 1994; NMFS, 2010a, 2011, 2012, 2013a, 2014, 2015a; Waring
et al., 2007, 2015). It is important to note that our authorization of
take equating to harassment of one group of each of these species is
not equivalent to expected exposure. We do not expect that these rarely
occurring (in the survey area) species will be exposed at all.
Nonetheless, we are providing USGS with authorization to take these
species, consistent with the terms of this IHA, in the unlikely event
they are encountered. We provide a brief description for each of these
species below.
Northern Bottlenose Whale--Northern bottlenose whales are
considered extremely rare in U.S. Atlantic waters, with only five NMFS
sightings. The southern extent of distribution is generally considered
to be approximately Nova Scotia (though Mitchell and Kozicki (1975)
reported stranding records as far south as Rhode Island), and there
have been no sightings within the survey areas. Whitehead and Wimmer
(2005) estimated the size of the population on the Scotian Shelf at 163
whales (95 percent CI 119-214). Whitehead and Hooker (2012) report that
northern bottlenose whales are found north of approximately 37.5[deg] N
and prefer deep waters along the continental slope. Roberts et al.
(2016) produced a stratified density model on the basis of four
sightings in the vicinity of Georges Bank (Roberts et al., 2015b). The
five sightings in U.S. waters yield a mean group size of 2.2 whales,
while MacLeod and D'Amico report a mean group size of 3.6. Here, we
authorize take of one group with a maximum group size of four whales.
Killer Whale--Killer whales are also considered rare in U.S.
Atlantic waters (Katona et al., 1988; Forney and Wade, 2006),
constituting 0.1 percent of marine mammal sightings in the 1978-81
Cetacean and Turtle Assessment Program surveys (CETAP, 1982). Roberts
et al. (2016) produced a stratified density model on the basis of four
killer whale sightings (Roberts et al., 2015g), though Lawson and
Stevens (2014) provide a minimum abundance estimate of 67 photo-
identified individual killer whales. Available information suggests
that survey encounters with killer whales will be unlikely but could
occur anywhere within the survey area and at any time of year (e.g.,
Lawson and Stevens, 2014). Silber et al. (1994) reported observations
of two and 15 killer whales in the Gulf of California (mean group size
8.5), while May-Collado et al. (2005) described mean group size of 3.6
whales off the Pacific coast of Costa Rica. Based on 12 CETAP sightings
and one group observed during NOAA surveys (CETAP, 1982; NMFS, 2014),
the average group size in the Atlantic is 6.8 whales. Therefore, we
[[Page 39702]]
authorize take of one group with a maximum group size of seven whales.
False Killer Whale--Although records of false killer whales from
the U.S. Atlantic are uncommon, a combination of sighting, stranding,
and bycatch records indicates that this species does occur in the
western North Atlantic (Waring et al., 2015). Baird (2009) suggests
that false killer whales may be naturally uncommon throughout their
range. Roberts et al. (2016) produced a stratified density model on the
basis of two false killer whale sightings (Roberts et al., 2015m), and
NMFS produced the first abundance estimate for false killer whales on
the basis of one sighting during 2011 shipboard surveys (Waring et al.,
2015). Similar to the killer whale, we believe survey encounters will
be unlikely but could occur anywhere within the survey area and at any
time of year. Mullin et al. (2004) reported a mean false killer whale
group size of 27.5 from the Gulf of Mexico, and May-Collado et al.
(2005) described mean group size of 36.2 whales off the Pacific coast
of Costa Rica. The few sightings from CETAP (1982) and from NOAA
shipboard surveys give an average group size of 10.3 whales. As a
precaution, we authorize take of one group with a maximum group size of
28 whales, as reported from the Gulf of Mexico.
Pygmy Killer Whale--The pygmy killer whale is distributed worldwide
in tropical to sub-tropical waters, and is assumed to be part of the
cetacean fauna of the tropical western North Atlantic (Jefferson et
al., 1994; Waring et al., 2007). Pygmy killer whales are rarely
observed by NOAA surveys outside the Gulf of Mexico--one group was
observed off of Cape Hatteras in 1992--and the rarity of such sightings
may be due to a naturally low number of groups compared to other
cetacean species (Waring et al., 2007). NMFS has never produced an
abundance estimate for this species and Roberts et al. (2016) were not
able to produce a density model for the species. The 1992 sighting was
of six whales; therefore, we authorize take of one group with a maximum
group size of six whales.
Melon-headed Whale--Similar to the pygmy killer whale, the melon-
headed whale is distributed worldwide in tropical to sub-tropical
waters, and is assumed to be part of the cetacean fauna of the tropical
western North Atlantic (Jefferson et al., 1994; Waring et al., 2007).
Melon-headed whales are rarely observed by NOAA surveys outside the
Gulf of Mexico--groups were observed off of Cape Hatteras in 1999 and
2002--and the rarity of such sightings may be due to a naturally low
number of groups compared to other cetacean species (Waring et al.,
2007). NMFS has never produced an abundance estimate for this species
and Roberts et al. (2016) produced a stratified density model on the
basis of four sightings (Roberts et al., 2015d). The two sightings
reported by Waring et al. (2007) yield an average group size of 50
whales; therefore, we authorize take of a single group of a maximum of
50 whales.
Spinner Dolphin--Distribution of spinner dolphins in the Atlantic
is poorly known, but they are thought to occur in deep water along most
of the U.S. coast south to the West Indies and Venezuela (Waring et
al., 2014). There have been a handful of sightings in deeper waters off
the northeast United States and one sighting during a 2011 NOAA
shipboard survey off North Carolina, as well as stranding records from
North Carolina south to Florida and Puerto Rico (Waring et al., 2014).
Roberts et al. (2016) provide a stratified density model on the basis
of two sightings (Roberts et al., 2015i). Regarding group size, Mullin
et al. (2004) report a mean of 91.3 in the Gulf of Mexico; May-Collado
(2005) describe a mean of 100.6 off the Pacific coast of Costa Rica;
and CETAP (1982) sightings in the Atlantic yield a mean group size of
42.5 dolphins. As a precaution, we authorize taking a single group with
a maximum size of 91 dolphins (derived from mean group size reported in
Mullin et al. 2004).
Fraser's Dolphin--As was stated for both the pygmy killer whale and
melon-headed whale, the Fraser's dolphin is distributed worldwide in
tropical waters, and is assumed to be part of the cetacean fauna of the
tropical western North Atlantic (Perrin et al., 1994; Waring et al.,
2007). The paucity of sightings of this species may be due to naturally
low abundance compared to other cetacean species (Waring et al., 2007).
Despite possibly being more common in the Gulf of Mexico than in other
parts of its range (Dolar 2009), there were only five reported
sightings during NOAA surveys from 1992-2009. In the Atlantic, NOAA
surveys have yielded only two sightings (Roberts et al., 2015f). May-
Collado et al. (2005) reported a single observation of 158 Fraser's
dolphins off the Pacific coast of Costa Rica, and Waring et al. (2007)
describe a single observation of 250 Fraser's dolphins in the Atlantic,
off Cape Hatteras. Therefore, we authorize take of a single group with
a maximum group size of 204 dolphins (derived from average of May-
Collado et al. 2005 and Waring et al. 2007 sightings data).
Atlantic White-sided Dolphin--White-sided dolphins are found in
temperate and sub-polar continental shelf waters of the North Atlantic,
primarily in the Gulf of Maine and north into Canadian waters (Waring
et al., 2016). Palka et al. (1997) suggest the existence of stocks in
the Gulf of Maine, Gulf of St. Lawrence, and Labrador Sea. Stranding
records from Virginia and North Carolina suggest a southerly winter
range extent of approximately 35[deg] N (Waring et al., 2016);
therefore, it is possible that the surveys could encounter white-sided
dolphins. Roberts et al. (2016) elected to split their study area at
the north wall of the Gulf Stream, separating the cold northern waters,
representing probable habitat, from warm southern waters, where white-
sided dolphins are likely not present (Roberts et al., 2015k). Over 600
observations of Atlantic white-sided dolphins during CETAP (1982) and
during NMFS surveys provide a mean group size estimate of 47.7
dolphins, while Weinrich et al. (2001) reported a mean group size of 52
dolphins. Due to this data, we authorize take of a single group with a
maximum group size of 48 dolphins.
Table 8--Numbers of Incidental Take Authorized
------------------------------------------------------------------------
Level B take
Species ** Level A take
------------------------------------------------------------------------
Humpback whale.......................... 3 0
Sei whale............................... 3 0
Fin whale............................... 5 0
Sperm whale............................. 161 0
Kogia spp............................... 9 0
Beaked whales........................... 128 0
Northern bottlenose whale *............. * 4 0
Rough-toothed dolphin................... 10 0
Common bottlenose dolphin............... 757 0
[[Page 39703]]
Clymene dolphin......................... 122 0
Atlantic spotted dolphin................ 1,598 0
Pantropical spotted dolphin............. 50 0
Spinner dolphin *....................... * 91 0
Striped dolphin......................... 1,459 0
Short-beaked common dolphin............. 1,620 0
Fraser's dolphin *...................... * 204 0
Atlantic white-sided dolphin *.......... * 48 0
Risso's dolphin......................... 237 0
Melon-headed whale *.................... * 50 0
Pygmy killer whale *.................... * 6 0
False killer whale *.................... *28 0
Killer whale *.......................... * 7 0
Pilot whales............................ 288 0
------------------------------------------------------------------------
* Level B harassment take for rare species represent take of a single
group.
** Take numbers for non-rare species are the same as those reported in
Table 7.
Mitigation
In order to issue an IHA under Section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to such
activity, and other means of effecting the least practicable impact on
such species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of such species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting such
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, we
carefully consider two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned) the likelihood of effective implementation (probability
implemented as planned); and
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost and impact on
operations.
USGS has reviewed mitigation measures employed during seismic
research surveys authorized by NMFS under previous incidental
harassment authorizations, as well as recommended best practices in
Richardson et al. (1995), Pierson et al. (1998), Weir and Dolman
(2007), Nowacek et al. (2013), Wright (2014), and Wright and Cosentino
(2015), and has incorporated a suite of mitigation measures into their
project description based on the above sources.
To reduce the potential for disturbance from acoustic stimuli
associated with the activities, USGS will implement the following
mitigation measures for marine mammals:
(1) Vessel-based visual mitigation monitoring;
(2) Establishment of a marine mammal exclusion zone (EZ);
(3) Shutdown procedures;
(4) Ramp-up procedures; and
(5) Vessel strike avoidance measures.
In addition, USGS will establish a marine mammal buffer zone.
Protected Species Observer (PSO) observations will take place
during all daytime airgun operations and nighttime start ups (if
applicable) of the airguns. If airguns are operating throughout the
night, observations will begin 30 minutes prior to sunrise. If airguns
are operating after sunset, observations will continue until 30 minutes
following sunset. Following a shutdown for any reason, observations
will occur for at least 30 minutes prior to the planned start of airgun
operations. Observations will also occur for 30 minutes after airgun
operations cease for any reason. Observations will also be made during
daytime periods when the R/V Hugh R. Sharp is underway without seismic
operations, such as during transits, to allow for comparison of
sighting rates and behavior with and without airgun operations and
between acquisition periods. Airgun operations will be suspended when
marine mammals are observed within, or about to enter, the designated
Exclusion Zone (EZ) (as described below).
During seismic operations, three visual PSOs will be based aboard
the R/V Hugh R. Sharp. PSOs will be appointed by USGS with NMFS
approval. During the majority of seismic operations (excluding ramp-
up), one PSOs will monitor for marine mammals around the seismic
vessel. PSO(s) will be on duty in shifts of duration no longer than
four hours. Other crew will also be instructed to assist in detecting
marine mammals and in implementing mitigation requirements (if
practical). Before the start of the seismic survey, the crew will be
given additional instruction in detecting marine mammals and
implementing mitigation requirements.
The R/V Hugh R. Sharp is a suitable platform from which PSOs will
watch for marine mammals. Standard equipment for marine mammal
observers will be 7 x 50 reticle binoculars, optical range finders, and
Big Eye binoculars. At night, night-vision equipment will be available.
The observers will be in communication with ship's officers on the
bridge and scientists in the vessel's operations laboratory, so they
can advise promptly of the need for avoidance maneuvers or seismic
source shutdown.
The PSOs must have no tasks other than to conduct observational
effort, record observational data, and communicate with and instruct
relevant vessel crew with regard to the presence of marine mammals and
mitigation requirements. PSO resumes will be
[[Page 39704]]
provided to NMFS for approval. At least one PSO must have a minimum of
90 days at-sea experience working as a PSO during a seismic survey. One
``experienced'' visual PSO will be designated as the lead for the
entire protected species observation team. The lead will serve as
primary point of contact for the USGS scientist-in-charge or his/her
designee. The PSOs must have successfully completed relevant training,
including completion of all required coursework and passing a written
and/or oral examination developed for the training program, and must
have successfully attained a bachelor's degree from an accredited
college or university with a major in one of the natural sciences and a
minimum of 30 semester hours or equivalent in the biological sciences
and at least one undergraduate course in math or statistics. The
educational requirements may be waived if the PSO has acquired the
relevant skills through alternate training, including (1) secondary
education and/or experience comparable to PSO duties; (2) previous work
experience conducting academic, commercial, or government-sponsored
marine mammal surveys; or (3) previous work experience as a PSO; the
PSO will demonstrate good standing and consistently good performance of
PSO duties.
Exclusion Zone and Buffer Zone
An EZ is a defined area within which occurrence of a marine mammal
triggers mitigation action intended to reduce the potential for certain
outcomes, e.g., auditory injury, disruption of critical behaviors. The
PSOs will establish a minimum EZ with a 100 m radius from the airgun
array. The 100 m EZ will be based on radial distance from any element
of the airgun array (rather than being based on the center of the array
or around the vessel itself). With certain exceptions (described
below), if a marine mammal appears within, enters, or appears on a
course to enter this zone, the acoustic source will be shut down (see
Shutdown Procedures below).
The 100 m radial distance of the standard EZ is precautionary in
the sense that it will be expected to contain sound exceeding injury
criteria (Level A harassment thresholds) for all marine mammal hearing
groups (Table 6) while also providing a consistent, reasonably
observable zone within which PSOs will typically be able to conduct
effective observational effort.
Our intent in prescribing a standard EZ distance is to (1)
encompass zones within which auditory injury could occur on the basis
of instantaneous exposure; (2) provide additional protection from the
potential for more severe behavioral reactions (e.g., panic,
antipredator response) for marine mammals at relatively close range to
the acoustic source; (3) provide consistency for PSOs, who need to
monitor and implement the EZ; and (4) define a distance within which
detection probabilities are reasonably high for most species under
typical conditions.
PSOs will also establish and monitor an additional 100 m buffer
zone beginning from the outside extent of the 100 m EZ. During use of
the acoustic source, occurrence of marine mammals within the 100 m
buffer zone will be communicated to the USGS scientist-in-charge or
his/her designee to prepare for potential shutdown of the acoustic
source. The 100 m buffer zone is discussed further under Ramp-Up
Procedures below.
Shutdown Procedures
If a marine mammal is detected outside the EZ but is likely to
enter the EZ, the airguns will be shut down before the animal is within
the EZ. Likewise, if a marine mammal is already within the EZ when
first detected, the airguns will be shut down immediately.
Following a shutdown, airgun activity will not resume until the
marine mammal has cleared the 100 m EZ. The animal will be considered
to have cleared the 100 m EZ if the following conditions have been met:
It is visually observed to have departed the 100 m EZ;
it has not been seen within the 100 m EZ for 15 min in the
case of small odontocetes; or
it has not been seen within the 100 m EZ for 30 min in the
case of mysticetes and large odontocetes, including sperm, pygmy and
dwarf sperm, beaked whales, and large delphinids.
This shutdown requirement will be in place for all marine mammals,
with the exception of small delphinoids under certain circumstances.
This exception to the shutdown requirement will apply solely to
specific genera of small dolphins--Tursiops, Steno, Stenella,
Lagenorhynchus and Delphinus--Instead of shutdown, the acoustic source
must be powered down to the smallest single element of the array if a
dolphin of the indicated genera appears within or enters the 100-m
exclusion zone. If there is uncertainty regarding identification (i.e.,
whether the observed animal(s) belongs to the group described above),
shutdown must be implemented. Power-down conditions shall be maintained
until the animal(s) are no longer observed within the exclusion zone,
following which full-power operations may be resumed without ramp-up.
PSOs may elect to waive the power-down requirement if the animal(s)
appear to be voluntarily approaching the vessel for the purpose of
interacting with the vessel or towed gear, and may use best
professional judgment in making this decision.
We include this small delphinoid exception because shutdown
requirements for small delphinoids under all circumstances represent
practicability concerns without likely commensurate benefits for the
animals in question. Small delphinoids are generally the most commonly
observed marine mammals in the specific geographic region and will
typically be the only marine mammals likely to intentionally approach
the vessel. As described below, auditory injury is extremely unlikely
to occur for mid-frequency cetaceans (e.g., delphinids), as this group
is relatively insensitive to sound produced at the predominant
frequencies in an airgun pulse while also having a relatively high
threshold for the onset of auditory injury (i.e., permanent threshold
shift). Please see ``Potential Effects of the Specified Activity on
Marine Mammals'' in the Federal Register notice for the proposed IHA
(83 FR 25268; May 31, 2018) for further discussion of sound metrics and
thresholds and marine mammal hearing.
A large body of anecdotal evidence indicates that small delphinoids
commonly approach vessels and/or towed arrays during active sound
production for purposes of bow riding, with no apparent effect observed
in those delphinoids (e.g., Barkaszi et al., 2012). The potential for
increased shutdowns resulting from such a measure will require the R/V
Hugh R. Sharp to revisit the missed track line to reacquire data,
resulting in an overall increase in the total sound energy input to the
marine environment and an increase in the total duration over which the
survey is active in a given area. Although other mid-frequency hearing
specialists (e.g., large delphinoids) are no more likely to incur
auditory injury than are small delphinoids, they are much less likely
to approach vessels. Therefore, retaining a shutdown requirement for
large delphinoids will not have similar impacts in terms of either
practicability for the applicant or corollary increase in sound energy
output and time on the water. We do anticipate some benefit for a
shutdown requirement for large delphinoids in that it simplifies
somewhat the total range of decision-making for PSOs and may preclude
any potential for physiological effects other
[[Page 39705]]
than to the auditory impacts. In addition, the required shutdown
measure may prevent more severe behavioral reactions for any large
delphnoids in close proximity to the source vessel.
Shutdown of the acoustic source will also be required upon
observation beyond the 100 m EZ of any of the following:
A large whale (i.e., sperm whale or any baleen whale) with
a calf;
An aggregation of large whales of any species (i.e., sperm
whale or any baleen whale) that does not appear to be traveling (e.g.,
feeding, socializing, etc.); or
A marine mammal species not authorized (i.e., a North
Atlantic right whale) for take that is approaching or entering the
Level B harassment zone.
An authorized marine mammal species that has reached its
total allotted Level B harassment take that is approaching or entering
the Level B harassment zone.
These will be the only four potential situations that will require
shutdown of the array for marine mammals observed beyond the 100 m EZ.
Ramp-Up Procedures
Ramp-up of an acoustic source is intended to provide a gradual
increase in sound levels following a shutdown, enabling animals to move
away from the source if the signal is sufficiently aversive prior to
its reaching full intensity. Ramp-up will be required after the array
is shut down for any reason. Ramp up to the full array will take 20
minutes, starting with operation of a single airgun and with one
additional airgun added every 5 minutes.
At least two PSOs will be required to monitor during ramp-up.
During ramp up, the PSOs will monitor the 100 m EZ, and if marine
mammals were observed within or approaching the 100 m EZ, a shutdown
will be implemented as though the full array were operational. If
airguns have been shut down due to PSO detection of a marine mammal
within or approaching the 100 m EZ, ramp-up will not be initiated until
all marine mammals have cleared the EZ, during the day or night.
Criteria for clearing the EZ will be as described above.
Thirty minutes of pre-clearance observation are required prior to
ramp-up for any shutdown of longer than 30 minutes (i.e., if the array
were shut down during transit from one line to another). This 30 minute
pre-clearance period may occur during any vessel activity (i.e.,
transit). If a marine mammal were observed within or approaching the
100 m EZ or 100 m buffer zone (i.e., total 200 m distance) during this
pre-clearance period, ramp-up will not be initiated until all marine
mammals cleared the 100 m EZ or 100 m buffer zone. Criteria for
clearing the EZ will be as described above. If the airgun array has
been shut down for reasons other than mitigation (e.g., mechanical
difficulty) for a period of less than 30 minutes, it may be activated
again without ramp-up if PSOs have maintained constant visual
observation and no detections of any marine mammal have occurred within
the EZ or 100 m buffer zone. Ramp-up will be planned to occur during
periods of good visibility when possible. However, ramp-up will be
allowed at night and during poor visibility if the 100 m EZ and 100 m
buffer zone have been monitored by visual PSOs for 30 minutes prior to
ramp-up.
The USGS scientist-in-charge or his/her designee will be required
to notify a designated PSO of the planned start of ramp-up as agreed-
upon with the lead PSO; the notification time will not be less than 60
minutes prior to the planned ramp-up. A designated PSO must be notified
again immediately prior to initiating ramp-up procedures and the USGS
scientist-in-charge or his/her designee must receive confirmation from
the PSO to proceed. The USGS scientist-in-charge or his/her designee
must provide information to PSOs documenting that appropriate
procedures were followed. Following deactivation of the array for
reasons other than mitigation, the USGS scientist-in-charge or his/her
designee will be required to communicate the near-term operational plan
to the lead PSO with justification for any planned nighttime ramp-up.
Vessel Strike Avoidance Measures
Vessel strike avoidance measures are intended to minimize the
potential for collisions with marine mammals. These requirements do not
apply in any case where compliance will create an imminent and serious
threat to a person or vessel or to the extent that a vessel is
restricted in its ability to maneuver and, because of the restriction,
cannot comply.
The measures include the following: The USGS scientist-in-charge or
his/her designee, the vessel operator (The University of Delaware) and
crew will maintain a vigilant watch for all marine mammals and slow
down or stop the vessel or alter course to avoid striking any marine
mammal. A visual observer aboard the vessel will monitor a vessel
strike avoidance zone around the vessel according to the parameters
stated below. Visual observers monitoring the vessel strike avoidance
zone will be either third-party observers or crew members, but crew
members responsible for these duties will be provided sufficient
training to distinguish marine mammals from other phenomena. Vessel
strike avoidance measures will be followed during surveys and while in
transit.
The vessel will maintain a minimum separation distance of 100 m
from large whales (i.e., baleen whales and sperm whales) except for
North Atlantic right whales. The vessel will maintain a minimum
separation distance of 500 m from North Atlantic right whales. If a
large whale is located within 100 m of the vessel or a North Atlantic
right whale is located within 500 m of the vessel, the vessel will
reduce speed and shift the engine to neutral, and will not engage the
engines until the whale has moved outside of the vessel's path and the
minimum separation distance has been established. If the vessel is
stationary, the vessel will not engage engines until the whale(s) has
moved out of the vessel's path and beyond 100 m or 500 m for North
Atlantic right whale. The vessel will maintain a minimum separation
distance of 50 m from all other marine mammals (with the exception of
delphinids of the genera Tursiops, Steno, Stenella, Lagenorhynchus and
Delphinus that approach the vessel, as described above). If an animal
is encountered during transit, the vessel will attempt to remain
parallel to the animal's course, avoiding excessive speed or abrupt
changes in course. Vessel speeds will be reduced to 10 kn or less when
mother/calf pairs, pods, or large assemblages of cetaceans (what
constitues ``large'' will vary depending on species) are observed
within 500 m of the vessel. Mariners may use professional judgment as
to when such circumstances warranting additional caution are present.
Actions To Minimize Additional Harm to Live-Stranded (or Milling)
Marine Mammals
In the event of a live stranding (or near-shore atypical milling)
event within 50 km of the survey operations, where the NMFS stranding
network is engaged in herding or other interventions to return animals
to the water, the Director of OPR, NMFS (or designee) will advise the
IHA-holder of the need to implement shutdown procedures for all active
acoustic sources operating within 50 km of the stranding. Shutdown
procedures for live stranding or milling marine mammals include the
following:
[[Page 39706]]
If at any time, the marine mammal(s) die or are
euthanized, or if herding/intervention efforts are stopped, the
Director of OPR, NMFS (or designee) will advise the IHA-holder that the
shutdown is no longer needed.
Otherwise, shutdown procedures will remain in effect until
the Director of OPR, NMFS (or designee) determines and advises the IHA-
holder that all live animals involved have left the area (either of
their own volition or following an intervention).
If further observations of the marine mammals indicate the
potential for re-stranding, additional coordination with the IHA-holder
will be required to determine what measures are necessary to minimize
that likelihood (e.g., extending the shutdown or moving operations
farther away) and to implement those measures as appropriate.
Shutdown procedures are not related to the investigation of the
cause of the stranding and their implementation is not intended to
imply that the specified activity is the cause of the stranding.
Rather, shutdown procedures are intended to protect marine mammals
exhibiting indicators of distress by minimizing their exposure to
possible additional stressors, regardless of the factors that
contributed to the stranding.
Based on our evaluation of the applicant's measures, NMFS
determined that the 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.
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
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 will
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
Mitigation and monitoring effectiveness.
USGS submitted a marine mammal monitoring and reporting plan in
their IHA application. Monitoring that is designed specifically to
facilitate mitigation measures, such as monitoring of the EZ to inform
potential shutdowns of the airgun array, are described above and are
not repeated here.
USGS's monitoring and reporting plan includes the following
measures:
Vessel-Based Visual Monitoring
As described above, PSO observations will take place during daytime
airgun operations and nighttime start-ups (if applicable) of the
airguns. During seismic operations, three visual PSOs will be based
aboard the R/V Hugh R. Sharp. PSOs will be appointed by USGS with NMFS
approval. During the majority of seismic operations (excluding ramp-
up), one PSO will monitor for marine mammals around the seismic vessel.
PSOs will be on duty in shifts of duration no longer than four hours.
Other crew will also be instructed to assist in detecting marine
mammals and in implementing mitigation requirements (if practical).
During daytime, PSOs will scan the area around the vessel
systematically with reticle binoculars, Big Eye binoculars, and with
the naked eye. At night, PSOs will be equipped with night-vision
equipment.
PSOs will record data to estimate the numbers of marine mammals
exposed to various received sound levels and to document apparent
disturbance reactions or lack thereof. Data will be used to estimate
numbers of animals potentially taken by harassment. They will also
provide information needed to order a shutdown of the airguns when a
marine mammal is within or near the EZ. When a sighting is made, the
following information about the sighting will be recorded:
(1) Species, group size, age/size/sex categories (if determinable),
behavior when first sighted and after initial sighting, heading (if
consistent), bearing and distance from seismic vessel, sighting cue,
apparent reaction to the airguns or vessel (e.g., none, avoidance,
approach, paralleling, etc.), and behavioral pace; and
(2) Time, location, heading, speed, activity of the vessel, sea
state, visibility, and sun glare.
All observations and shutdowns will be recorded in a standardized
format. Data will be entered into an electronic database. The accuracy
of the data entry will be verified by computerized data validity checks
as the data are entered and by subsequent manual checking of the
database. These procedures will allow initial summaries of data to be
prepared during and shortly after the field program and will facilitate
transfer of the data to statistical, graphical, and other programs for
further processing and archiving. The time, location, heading, speed,
activity of the vessel, sea state, visibility, and sun glare will also
be recorded at the start and end of each observation watch, and during
a watch whenever there is a change in one or more of the variables.
Results from the vessel-based observations will provide:
(1) The basis for real-time mitigation (e.g., airgun shutdown);
(2) Information needed to estimate the number of marine mammals
potentially taken by harassment, which must be reported to NMFS;
(3) Data on the occurrence, distribution, and activities of marine
mammals in the area where the seismic study is conducted;
(4) Information to compare the distance and distribution of marine
mammals relative to the source vessel at times with and without seismic
activity; and
(5) Data on the behavior and movement patterns of marine mammals
seen at times with and without seismic activity.
[[Page 39707]]
Reporting Injured or Dead Marine Mammals
Discovery of Injured or Dead Marine Mammal--In the event that
personnel involved in the survey activities covered by the
authorization discover an injured or dead marine mammal, the IHA-holder
shall report the incident to the Office of Protected Resources (OPR),
NMFS and to regional stranding coordinators as soon as feasible. The
report must 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.
Vessel Strike--In the event of a ship strike of a marine mammal by
any vessel involved in the activities covered by the authorization, the
IHA-holder shall report the incident to OPR, NMFS and to regional
stranding coordinators as soon as feasible. The report must 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).
Additional Information Requests--If NMFS determines that the
circumstances of any marine mammal stranding found in the vicinity of
the activity suggest investigation of the association with survey
activities is warranted (example circumstances noted below), and an
investigation into the stranding is being pursued, NMFS will submit a
written request to the IHA-holder indicating that the following initial
available information must be provided as soon as possible, but no
later than 7 business days after the request for information.
Status of all sound source use in the 48 hours preceding
the estimated time of stranding and within 50 km of the discovery/
notification of the stranding by NMFS; and
If available, description of the behavior of any marine
mammal(s) observed preceding (i.e., within 48 hours and 50 km) and
immediately after the discovery of the stranding.
Examples of circumstances that could trigger the additional
information request include, but are not limited to, the following:
Atypical nearshore milling events of live cetaceans;
Mass strandings of cetaceans (two or more individuals, not
including cow/calf pairs);
Beaked whale strandings;
Necropsies with findings of pathologies that are unusual
for the species or area; or
Stranded animals with findings consistent with blast
trauma.
In the event that the investigation is still inconclusive, the
investigation of the association of the survey activities is still
warranted, and the investigation is still being pursued, NMFS may
provide additional information requests, in writing, regarding the
nature and location of survey operations prior to the time period
above.
Reporting
A report will be submitted to NMFS within 90 days after the end of
the survey. The report will describe the operations that were conducted
and sightings of marine mammals near the operations. The report will
provide full documentation of methods, results, and interpretation
pertaining to all monitoring and will summarize the dates and locations
of seismic operations, and all marine mammal sightings (dates, times,
locations, activities, associated seismic survey activities). The
report will also include estimates of the number and nature of
exposures that occurred above the harassment threshold based on PSO
observations, including an estimate of those on the trackline but not
detected.
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' 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).
NMFS does not anticipate that serious injury or mortality will
occur as a result of USGS's seismic survey, even in the absence of
mitigation. Thus, the authorization does not authorize any mortality.
Potential impacts to marine mammal habitat were discussed
previously in the Federal Register notice for the proposed IHA (83 FR
25268; May 31, 2018). Marine mammal habitat may be impacted by elevated
sound levels, but these impacts will be temporary. Feeding behavior is
not likely to be significantly impacted, as marine mammals appear to be
less likely to exhibit behavioral reactions or avoidance responses
while engaged in feeding activities (Richardson et al., 1995). Prey
species are mobile and are broadly distributed throughout the project
area; therefore, marine mammals
[[Page 39708]]
that may be 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, the availability of similar habitat and resources
in the surrounding area, and 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. In addition, there are no feeding, mating or calving areas
known to be biologically important to marine mammals within the project
area during the time of the survey (LaBrecque et al., 2015).
The acoustic ``footprint'' of the survey will be very small
relative to the ranges of all marine mammals that will potentially be
affected. Sound levels will increase in the marine environment in a
relatively small area surrounding the vessel compared to the range of
the marine mammals within the survey area. The seismic array will be
active 24 hours per day throughout the duration of the survey. However,
the very brief overall duration of the survey (22 days with 19 days of
airgun operations) will further limit potential impacts that may occur
as a result of the activity.
The mitigation measures are expected to reduce the number and/or
severity of takes by allowing for detection of marine mammals in the
vicinity of the vessel by visual and acoustic observers, and by
minimizing the severity of any potential exposures via shutdowns of the
airgun array.
Of the marine mammal species that are likely to occur in the
project area during the survey timeframe, the following species are
listed as endangered under the ESA; fin, sei, and sperm whales. There
are currently insufficient data to determine population trends for
these species (Hayes et al., 2017); however, we are authorizing very
small numbers of takes for these species (Table 6), relative to their
population sizes (again, when compared to mean abundance estimates, for
purposes of comparison only). Therefore, we do not expect population-
level impacts to any of these species. The other marine mammal species
that may be taken by harassment during USGS's seismic survey are not
listed as threatened or endangered under the ESA. There is no
designated critical habitat for any ESA-listed marine mammals within
the project area; of the non-listed marine mammals for which we
authorize take, none are considered ``depleted'' or ``strategic'' by
NMFS under the MMPA, except for pilot whales and false killer whales.
NMFS concludes that exposures to marine mammal species due to
USGS's seismic survey will 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 take estimates to impact annual rates of recruitment or
survival.
In summary and as described above, the following factors primarily
support our 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 injury (Level A take), serious injury or mortality is
anticipated or authorized;
The anticipated impacts of the activity on marine mammals
will primarily be temporary behavioral changes due to avoidance of the
area around the survey vessel. The relatively short duration of the
survey (22 days with 19 days of airgun operations) will further limit
the potential impacts of any temporary behavioral changes that will
occur;
The availability of alternate areas of similar habitat
value for marine mammals to temporarily vacate the survey area during
the survey to avoid exposure to sounds from the activity;
The project area does not contain areas of significance
for feeding, mating or calving;
The potential adverse effects on fish or invertebrate
species that serve as prey species for marine mammals from the survey
will be temporary and spatially limited; and
The mitigation measures, including visual and acoustic
monitoring and shutdowns, are expected to minimize potential impacts to
marine mammals.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the monitoring and mitigation
measures, NMFS finds that the total marine mammal take from the
activity will have a negligible impact on all affected marine mammal
species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under Section 101(a)(5)(D) of the MMPA for specified
activities other than military readiness activities. The MMPA does not
define small numbers and so, in practice, where estimated numbers are
available, NMFS compares the number of individuals taken to the most
appropriate estimation of abundance of the relevant species or stock in
our determination of whether an authorization is limited to small
numbers of marine mammals. Additionally, other qualitative factors may
be considered in the analysis, such as the temporal or spatial scale of
the activities.
Please see Tables 6 and 7 and the related text for information
relating to the basis for our small numbers analyses. Table 7 provides
the numbers of predicted exposures above specified received levels,
while Table 7 provides the numbers of take authorized. For the northern
bottlenose whale, Fraser's dolphin, melon-headed whale, false killer
whale, pygmy killer whale, killer whale, spinner dolphin, and white-
sided dolphin, we authorize take resulting from a single exposure of
one group of each species or stock, as appropriate (using average group
size), for each applicant. We believe that a single incident of take of
one group of any of these species represents take of small numbers for
that species. Due to the scarcity, broad spatial distributions, and
habitat preferences of these species relative to the areas where the
surveys will occur, NMFS concludes that the authorized take of a single
group of these species likely represent small numbers relative to the
affected species' overall population sizes. Therefore, based on the
analyses contained herein of the specified activity, we find that small
numbers of marine mammals will be taken for each of these eight
affected species or stocks for the specified activity. We do not
discuss these eight species further in this small numbers analysis.
As shown in Table 6, we used mean abundance estimates from Roberts
(2016) to calculate the percentage of population that is estimated to
be taken during the activities for non-rare species. The activity is
expected to impact a very small percentage of all marine mammal
populations. As presented in Table 6, take of all 21 marine mammal
species authorized for take is less than three percent of the abundance
estimate.
Based on the analysis contained herein of the activity (including
the mitigation and monitoring measures) and the anticipated take of
marine mammals, NMFS finds that small numbers of marine mammals will be
taken relative to the population size of the affected species or
stocks.
[[Page 39709]]
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 will not
have an unmitigable adverse impact on the availability of such species
or stocks for taking for subsistence purposes.
Endangered Species Act (ESA)
Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16
U.S.C. 1531 et seq.) requires that each Federal agency insure that any
action it authorizes, funds, or carries out is not likely to jeopardize
the continued existence of any endangered or threatened species or
result in the destruction or adverse modification of designated
critical habitat. To ensure ESA compliance for the issuance of IHAs,
NMFS consults internally, in this case with NMFS' ESA Interagency
Cooperation Division, whenever we authorize take for endangered or
threatened species.
NMFS's ESA Interagency Cooperation Division issued a Biological
Opinion on August 6, 2018 to NMFS Office of Protected Resources which
concluded that the USGS's MATRIX survey is not likely to jeopardize the
continued existence of the sei whale, fin whale, sperm whale, and north
Atlantic right whale or adversely modify critical habitat.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an
incidental harassment authorization) with respect to potential impacts
on the human environment. Accordingly, NMFS prepared an Environmental
Assessment (EA) to consider the environmental impacts associated with
the issuance of the IHA to USGS. We reviewed all comments submitted in
response to the Federal Register notice for the proposed IHA (83 FR
25268; May 31, 2018) prior to concluding our NEPA process and deciding
whether or not to issue a Finding of No Significant Impact (FONSI).
NMFS concluded that issuance of an IHA to USGS will not significantly
affect the quality of the human environment and prepared and issued a
FONSI in accordance with NEPA and NAO 216-6A. NMFS's EA and FONSI for
this activity are available on our website at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-research-and-other-activities.
Authorization
As a result of these determinations, we have issued an IHA to USGS
for conducting the described seismic survey activities from August 1,
2018 through July 31, 2019 provided the previously described
mitigation, monitoring, and reporting requirements are incorporated.
Dated: August 7, 2018.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2018-17170 Filed 8-9-18; 8:45 am]
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