[Federal Register Volume 84, Number 232 (Tuesday, December 3, 2019)]
[Notices]
[Pages 66156-66175]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-26091]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XR032]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Marine Site Characterization
Surveys Off of Delaware and Maryland
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
Skipjack Offshore Energy, LLC (Skipjack) to incidentally harass, by
Level B harassment only, marine mammals during marine site
characterization surveys offshore of Delaware in the area of the
Commercial Lease of Submerged Lands for Renewable Energy Development on
the Outer Continental Shelf (OCS-A 0519) and along potential submarine
cable routes to a landfall location in Delaware or Maryland.
DATES: This authorization is valid for one year from the date of
issuance.
FOR FURTHER INFORMATION CONTACT: Jordan Carduner, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the applications
and supporting documents, as well as a list of the references cited in
this document, may be obtained by visiting the internet at:
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable. In case of
problems accessing these documents, please call the contact listed
above.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are issued or, if the taking is limited to harassment, a notice of a
proposed incidental take authorization may be provided to the public
for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of such species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of such takings are set forth.
The definitions of all applicable MMPA statutory terms cited above
are included in the relevant sections below.
Summary of Request
On July 31, 2019, NMFS received a request from Skipjack for an IHA
to take marine mammals incidental to marine site characterization
surveys offshore of Delaware in the area of the Commercial Lease of
Submerged Lands for Renewable Energy Development on the Outer
Continental Shelf (OCS-A 0519) and along potential submarine cable
routes to a landfall location in Delaware or Maryland. A revised
application was received on August 15, 2019. NMFS deemed that request
to be adequate and complete. Skipjack's request is for the take of 17
marine mammal species by Level B harassment that would occur over the
course of 200 survey days. Neither Skipjack nor NMFS expects serious
injury or mortality to result from this activity and the activity is
expected to last no more than one year, therefore, an IHA is
appropriate.
[[Page 66157]]
Description of the Proposed Activity
Skipjack proposes to conduct marine site characterization surveys,
including high-resolution geophysical (HRG) and geotechnical surveys,
in the area of OCS-A 0519 (Lease Area) and along potential submarine
cable routes to landfall locations in either Delaware or Maryland. The
purpose of the surveys is to obtain a baseline assessment of seabed/
sub-surface soil conditions in the Lease Area and cable route corridors
to support the siting of potential future offshore wind projects.
Underwater sound resulting from Skipjack's surveys has the potential to
result in incidental take of marine mammals in the form of behavioral
harassment (i.e., Level B harassment only).
Skipjack's survey activities are anticipated to be supported by as
many as five total vessels, with as many as three vessels operating
concurrently. Survey vessels would maintain a speed of approximately 4
knots (kn) while transiting survey lines. A maximum of 200 total survey
days are expected to be required to complete the surveys. Skipjack's
geotechnical survey activities are described in detail in the notice of
proposed IHA (84 FR 51118; September 27, 2019). As described in that
notice, the geotechnical survey activities not expected to result in
the take of marine mammals and are therefore not analyzed further in
this document. The HRG survey activities proposed by Skipjack are also
described in detail in the notice of proposed IHA (84 FR 51118;
September 27, 2019). The HRG equipment that may be used by Skipjack are
shown in Table 1.
Table 1--Summary of Geophysical Survey Equipment Proposed for Use by Skipjack
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Sound level Sound level
Operating (SLrms dB re 1 (SLpk dB re 1 Pulse duration Repetition
Equipment Source type frequency (kHz) [micro]Pa m) [micro]Pa m) (width) rate (Hz) Beamwidth (degrees)
(millisecond)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Shallow Sub-bottom Profilers (Chirps)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Teledyne Benthos Chirp III-- Non-impulsive, 2 to 7.......... 197 -- 5 to 60......... 15 100.
TTV 170. mobile,
intermittent.
EdgeTech SB 216 (2000DS or Non-impulsive, 2 to 16......... 195 -- 20.............. 6 24.
3200 top unit). mobile, 2 to 8..........
intermittent.
EdgeTech 424................. Non-impulsive, 4 to 24......... 176 -- 3.4............. 2 71.
mobile,
intermittent.
EdgeTech 512................. Non-impulsive, 0.7 to 12....... 179 -- 9............... 8 80.
mobile,
intermittent.
GeoPulse 5430A............... Non-impulsive, 2 to 17......... 196 .............. 50.............. 10 55.
mobile,
intermittent.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Parametric Sub-bottom Profilers
--------------------------------------------------------------------------------------------------------------------------------------------------------
Innomar SES[dash]2000 Medium Non-impulsive, 85 to 115....... 247 -- 0.07 to 2....... 40-100 1-3.5.
100 SBP. mobile,
intermittent.
Innomar SES[dash]2000 Non-impulsive, 85 to 115....... 236 -- 0.07 to 2....... 60 1-3.5.
Standard & Plus. mobile,
intermittent.
Innomar SES[dash]2000 Medium Non-impulsive, 60 to 80........ 241 -- 0.1 to 2.5...... 40 1-3.5.
70. mobile,
intermittent.
Innomar SES[dash]2000 Quattro Non-impulsive, 85 to 115....... 245 -- 0.07 to 1....... 60 1-3.5.
mobile,
intermittent.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Medium Sub-bottom Profilers (Sparkers & Boomers)
--------------------------------------------------------------------------------------------------------------------------------------------------------
GeoMarine Geo-Source 800J Impulsive, 0.05 to 5....... 203 213 3.4............. 0.41 Omni.
Sparker. Mobile.
GeoMarine Geo-Source 600J Impulsive, 0.2 to 5........ 201 212 5.0............. 0.41 Omni.
Sparker. Mobile.
GeoMarine Geo-Source 400J Impulsive, 0.2 to 5........ 195 208 7.2............. 0.41 Omni.
Sparker. Mobile.
GeoResource 800J Sparker Impulsive, 0.05 to 5....... 203 213 3.4............. 0.41 Omni.
System. Mobile.
Applied Acoustics Duraspark Impulsive, 0.3 to 1.2...... 203 211 1.1............. 0.4 Omni.
400. Mobile.
Applied Acoustics triple Impulsive, 0.1 to 5........ 205 211 0.6............. 3 80.
plate S[dash]Boom (700-1000 Mobile.
Joules) \1\.
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Acoustic Corers
--------------------------------------------------------------------------------------------------------------------------------------------------------
PanGeo (LF Chirp)............ Non-impulsive, 2 to 6.5........ 177.5 -- 4.5............. 0.06 73.
stationary,
intermittent.
[[Page 66158]]
PanGeo (HF Chirp)............ Non-impulsive, 4.5 to 12.5..... 177.5 -- 4.5............. 0.06 73.
stationary,
intermittent.
Pangeo Parametric Sonar \5\.. Non-impulsive, 90 to 115....... 239 -- 0.25............ 40 3.5.
stationary,
intermittent.
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Positioning Systems
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sonardyne Ranger 2-- Non-impulsive, 19 to 34........ 194 -- 5............... 1 Omni.
Transponder. mobile,
intermittent.
Sonardyne Ranger 2 USBL HPT Non-impulsive, 19 to 34........ 194 -- 5............... 1 Not Reported.
3000/5/7000 Transceiver. mobile,
intermittent.
Sonardyne Scout Pro Non-impulsive, 35 to 50........ 188 -- 5............... 3 Not Reported.
Transponder. mobile,
intermittent.
IxSea GAPS Beacon System..... Non-impulsive, 8-16............ 188 .............. 12.............. 1 Omni.
mobile,
intermittent.
Easytrak Nexus 2 USBL Non-impulsive, 18 to 32........ 192 .............. 5............... 2 Omni.
Transceiver. mobile,
intermittent.
Kongsberg HiPAP 501/502 USBL Non-impulsive, 27-30.5......... 190 .............. 2............... 1 15.
Tranceiver. mobile,
intermittent.
EdgeTech BATS II Transponder. Non-impulsive, 17 to 30........ Not Reported .............. 5............... 3 Not Reported.
mobile,
intermittent.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Multi-beam Echosounders and Side Scan Sonar
--------------------------------------------------------------------------------------------------------------------------------------------------------
Reson SeaBat 7125 Multibeam Non-impulsive, 200 or 400...... 220 -- 0.03 to 0.3..... -- --
Echosounder. mobile,
intermittent.
RESON 700.................... Non-impulsive, 200 or 400...... 162 -- 0.33............ -- --
mobile,
intermittent.
R2SONIC...................... Non-impulsive, 200 or 400...... 162 -- 0.11............ -- --
mobile,
intermittent.
Klein 3900 SSS............... Non-impulsive, >445 kHz........ 242 -- 0.025........... -- --
mobile,
intermittent.
EdgeTech 4000 & 4125 SSS..... Non-impulsive, 410 kHz......... 225 -- 10.............. -- --
mobile,
intermittent.
EdgeTech 4200 SSS............ Non-impulsive, >300 kHz........ 215 -- 0.025........... -- --
mobile,
intermittent.
--------------------------------------------------------------------------------------------------------------------------------------------------------
-- = not applicable or reportable; dB re 1 [micro]Pa m = decibel reference to 1 micropascal meter; GAPS = Global Acoustic Positioning System; HF = high-
frequency; LF = low-frequency; omni = omnidirectional source; SL = source level; SLpk = peak source level (expressed as dB re 1 [micro]Pa m); SLrms =
root-mean-square source level (expressed as dB re 1 [micro]Pa m); SSS = side scan sonar; USBL = ultra-short baseline.
\4\ Crocker and Fratantonio (2016) provide S-boom measurements using two different power sources (CSP-D700 and CSP-N). The CSP-D700 power source was
used in the 700J measurements but not in the 1000J measurements. The CSP-N source was measured for both 700J and 1000J operations but resulted in a
lower source levels; therefore the single maximum source level value was used for both operational levels of the S-boom.
\5\ The Pangeo acoustic corer parametric sonar was scanned out of further analysis due to high frequency content, operational beam width of less than
eight degrees, and stationary operational position of less than 3.5 m above the seabed (Pangeo, 2018).
Of the potential HRG survey equipment planned for use, NMFS
determined the multi-beam echosounders, side-scan sonars, and acoustic
corers do not have the potential to result in the harassment of marine
mammals because these sources are either outside the functional hearing
ranges of marine mammals or do not result in sound that is expected to
propagate to distances that would result in harassment. Therefore,
these equipment types are not analyzed further in this document. All
other HRG equipment types planned for use by Skipjack as shown in Table
1 are expected to have the potential to result in the harassment of
marine mammals and are therefore carried forward in the analysis.
As described above, detailed description of Skipjack's planned
surveys is provided in the notice of proposed IHA (84 FR 51118;
September 27, 2019). Since that time, no changes have been made to the
activities. Therefore, a detailed description is not provided here.
Please refer to that notice for the detailed description of the
specified activity. Mitigation, monitoring, and reporting measures are
described in detail later in this document (please see ``Mitigation''
and ``Monitoring and Reporting'').
Comments and Responses
A notice of proposed IHA was published in the Federal Register on
September 27, 2019 (84 FR 51118). During the 30-day public comment
period, NMFS received comment letters from: (1) The Marine Mammal
[[Page 66159]]
Commission (Commission); (2) a group of environmental non-governmental
organizations (ENGOs) including the Natural Resources Defense Council,
Conservation Law Foundation, National Wildlife Federation, Defenders of
Wildlife, WDC North America, NY4WHALES, Surfrider Foundation, Mass
Audubon, International Marine Mammal Project of the Earth Island
Institute, and Wildlife Conservation Society; and (3) a member of the
general public. NMFS has posted the comments online at:
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable. The comment we
received from the general public was supportive of issuance of the IHA.
A summary of the public comments received from the Commission and the
ENGOs and NMFS' responses to those comments are below.
Comment 1: The Commission recommended that NMFS engage in various
efforts to ensure consistency in aspects of the MMPA incidental take
authorization process associated with this and similar specified
activities (e.g., site characterization surveys in service of placement
of wind energy facilities), including guidance related to
methodological and signal processing standards, guidance and tools
regarding sound propagation modeling for use by action proponents that
conduct HRG surveys.
Response: NMFS appreciates the Commission's interest in these
issues and will evaluate the need for and appropriate development of
guidance and tools.
Comment 2: The Commission recommended that NMFS include the
relevant inputs (i.e., source level, weighting factor adjustment,
source velocity, pulse duration, and repetition rate) used to estimate
the Level A harassment zones for all sources proposed for use by the
action proponents in Federal Register notices.
Response: NMFS strives to provide all information relevant to
modeling isopleth distances associated with sound sources used to
estimate marine mammal exposures. In this instance there were numerous
potential sound sources which NMFS determined are unlikely to have the
potential to result in Level A harassment and were not ultimately
relevant to marine mammal exposure modeling, therefore we provided the
inputs that were potentially relevant to the exposure modeling and that
were used for the take estimate.
Comment 3: The Commission recommended that NMFS implement a 50-m
Level B harassment zone for Skipjack's proposed survey based on an
assumption that in-situ measurements and resulting data collected for
sparkers is accurate and should be relied upon for modeling HRG
sources. The Commission also recommended that NMFS deem sound sources
de minimus in a consistent manner for all proposed IHAs and
rulemakings, and that, given the relatively small sizes of Level B
harassment zones, NMFS consider whether IHAs are necessary for HRG
surveys given proposed shutdown requirements and the added protection
afforded by lease-stipulated exclusion zones.
Response: NMFS supports the collection of sound field verification
data on HRG sources and will consider using these data in exposure
estimates when it is deemed reliable. At this time, NMFS has determined
the available data from sound field verification studies on directional
HRG sources is not reliable, but we will review sound field
verification data collected from omni-directional sources on a case by
case basis. However, NMFS has concerns with the reliability of some of
the sound field verification data that has been submitted previously
for omni-directional sources, therefore we are not willing to make
categorical assumptions about sound propagation distances associated
with these equipment types based on this previously submitted data.
NMFS has developed an interim method for determining the rms sound
pressure level (SPLrms) at the 160-dB isopleth HRG survey
equipment that incorporates frequency and some directionality to refine
estimated ensonified zones (this method is described in greater detail
in the Take Estimate section, below). NMFS provided this method to
Skipjack and Skipjack used this method to model isopleth distances to
the Level B harassment threshold for HRG sources (both directional and
omni-directional). NMFS believes this remains a sound and conservative
approach until data from sound field verification studies for HRG
sources can be relied upon consistently. NMFS will continue to base its
analyses of modeling of HRG sound sources on the best available
information.
NMFS agrees that sound sources should be analyzed in a consistent
manner and agrees that sources determined to result in de minimis
impact should generally be considered unlikely to result in take under
the MMPA. As an example, NMFS has determined that most types of
geotechnical survey equipment are generally unlikely to result in the
incidental take of marine mammals (in the absence of site-specific or
species-specific circumstances that may warrant additional analysis).
NMFS has not made such a determination with respect to HRG sources. As
NMFS has not made a determination that sound from all HRG sources would
be considered de minimis we cannot rule out the potential for these
sources to result in the incidental take of marine mammals.
Comment 4: The Commission recommended that NMFS include a
requirement for Skipjack to provide marine mammal observational
datasheets or raw sightings data in its draft and final monitoring
report.
Response: NMFS agrees with the Commission's recommendation and has
incorporated this requirement in the IHA.
Comment 5: The Commission recommended that NMFS refrain from using
the proposed IHA renewal process and that, if NMFS intends to use the
renewal process frequently or for authorizations that require a more
complex review or for which much new information has been generated,
that NMFS provide the Commission and other reviewers 30 days to
comment.
Response: As described in the Federal Register notice for the
proposed IHA and on NMFS' website where information on all MMPA
incidental take authorization processes is provided, requests for IHA
renewals are appropriate only in limited and well-defined
circumstances. NMFS does not anticipate many projects that would meet
all the criteria for a renewal. Nonetheless, information about the
renewal process and the opportunity to comment on a potential renewal
is included in every notice of a proposed IHA because NMFS cannot
predetermine who may seek or qualify for a renewal. Under section
101(a)(5)(D), it is up to an applicant to request incidental harassment
authorization; NMFS includes information about the potential renewal
process in all proposed IHAs because it is at least initially up to the
applicant to decide whether they want to seek qualification for a
renewal IHA. NMFS has also explained that the possibility of a renewal
must be included in the notice of the initial proposed IHA for the
agency to consider a renewal request, for the purpose of providing
adequate opportunity for public comment on the project during the 30-
day comment period on the appropriateness of, and any information
pertinent to, a renewal. Where the commenter has likely already
reviewed and commented on the initial proposed IHA and a potential
renewal for these same activities, activities by the same
[[Page 66160]]
IHA holder in the same geographic area, the abbreviated additional
comment period is sufficient for consideration of the results of the
preliminary monitoring report and new information (if any) from the
past months.
NMFS' purpose in providing for renewal is two-fold. First and
foremost, the efficiencies in dealing with these simple, low-impact
projects (which have already been fully described and analyzed in the
initial IHA) frees up limited staff resources to increase focus on more
complex and impactful projects and improves our ability to conserve and
protect marine mammals by even better evaluating and utilizing new
science, evolving technologies, and potential new mitigation measures.
In addition, while the agency has always striven for efficiency in
regulatory processes, recent directives have called for agencies to put
processes in place that reduce regulatory timelines and the regulatory
burden on the public. The renewal process reduces the effort needed by
both applicants and NMFS staff for simple, relatively low impact
projects with little to no uncertainty regarding effects that have
already been fully analyzed by the agency and considered by the
public--with no reduction in protection to marine mammals.
NMFS has taken a number of steps to ensure the public has adequate
notice, time, and information to be able to comment effectively on
renewal IHAs. Federal Register notices for proposed initial IHAs
identify the conditions under which a one-year renewal IHA could be
appropriate. This information would have been presented in the Request
for Public Comments section, which encouraged submission of comments on
a potential one-year Renewal in addition to the initial IHA during the
initial 30-day comment period. With renewal limited to another year of
identical or nearly identical activity in the same location or a subset
of the initial activity that was not completed, this information about
the renewal process and the project-specific information provided in
the Federal Register notice provides reviewers with the information
needed to provide information and comment on both the initial IHA and a
potential renewal for the project. Thus reviewers interested in
submitting comments on a proposed renewal during the additional 15-day
comment period will have already reviewed the activities, the species
and stocks affected, and the mitigation and monitoring measures, which
will not change from the IHA issued, and the anticipated effects of
those activities on marine mammals and provided their comments and any
information pertinent to a possible renewal during the initial 30-day
comment period. When we receive a request for a renewal IHA, if the
project is appropriate for a renewal we will publish notice of the
proposed IHA renewal in the Federal Register and provide the additional
15 days for public comment to allow review of the additional documents
(preliminary monitoring report, renewal request, and proposed renewal),
which should just confirm that the activities have not changed (or only
minor changes), commit to continue the same mitigation and monitoring
measures, and document that monitoring does not indicate any impacts of
a scale or nature not previously analyzed.
In addition, to minimize any burden on reviewers, NMFS will
directly contact all commenters on the initial IHA by email, phone, or,
if the commenter did not provide email or phone information, by postal
service to provide them direct notice about the opportunity to submit
any additional comments.
Comment 6: The ENGOs expressed concern that the IHA renewal process
discussed in the notice of proposed IHA is inconsistent with the
statutory requirements contained in section 101(a)(5)(D) of the MMPA.
The ENGOs asserted that IHAs can be valid for not more than one year
and both commenters stated that 30 days for comment, including on
Renewal IHAs, is required.
Response: NMFS' IHA Renewal process meets all statutory
requirements. All IHAs issued, whether an initial IHA or a renewal IHA,
are valid for a period of not more than one year, and the public has at
least 30 days to comment on all proposed IHAs, with a cumulative total
of 45 days for IHA renewals. One commenter characterized the agency's
request for comments as seeking comment on the renewal process and the
proposed IHA, but the request for comments was not so limited. While
there will be additional documents submitted with a renewal request,
for a qualifying renewal these will be limited to documentation that
NMFS will make available and use to verify that the activities are
identical to those in the initial IHA, are nearly identical such that
the changes would have either no effect on impacts to marine mammals or
decrease those impacts, or are a subset of activities already analyzed
and authorized but not completed under the initial IHA. NMFS will also
confirm, among other things, that the activities will occur in the same
location; involve the same species and stocks; provide for continuation
of the same mitigation, monitoring, and reporting requirements; and
that no new information has been received that would alter the prior
analysis. The renewal request will also contain a preliminary
monitoring report, but that is to verify that effects from the
activities do not indicate impacts of a scale or nature not previously
analyzed. The additional 15-day public comment period provides the
public an opportunity to review these few documents, provide any
additional pertinent information and comment on whether they think the
criteria for a renewal have been met. Between the initial 30-day
comment period on these same activities and the additional 15 days, the
total comment period for a renewal is 45 days.
In addition to the IHA renewal process being consistent with all
requirements under section 101(a)(5)(D), it is also consistent with
Congress' intent for issuance of IHAs to the extent reflected in
statements in the legislative history of the MMPA. Through the
provision for renewal in the regulations, description of the process
and express invitation to comment on specific potential renewal in the
Request for Public Comments section of each proposed IHA, the
description of the process on NMFS' website, further elaboration on the
process through responses to comments such as these, posting of
substantive documents on the agency's website, and provision of 30 or
45 days for public review and comment on all proposed initial IHAs and
renewal respectively, NMFS has ensured that the public is invited and
encouraged to participate fully in the agency decision-making process.
Comment 7: The ENGOs recommended that a minimum of four PSOs should
be required, following a two-on/two-off rotation, each responsible for
scanning no more than 180[deg] of the EZ at any given time, and that
observation must begin at least 30 minutes prior to the commencement of
geophysical survey activity and shall be conducted throughout the time
of geophysical survey activity.
Response: NMFS does not agree with the commenters that a minimum of
four PSOs should be required, following a two-on/two-off rotation, to
meet the MMPA requirement that mitigation must effect the least
practicable adverse impact upon the affected species or stocks and
their habitat. Previous IHAs issued for HRG surveys have required that
a single PSO must be stationed at the highest vantage point and engaged
in general 360-degree scanning during daylight hours. A number of
marine mammal monitoring reports submitted
[[Page 66161]]
to NMFS have demonstrated that project proponents have effectively
employed this approach. However, we note that Skipjack is required by
BOEM lease stipulations to have two PSOs on duty at all times during
surveys that occur during daylight hours. The IHA already requires 30
minutes of pre-clearance observation prior to the commencement of
survey activities.
Comment 8: The ENGOs recommended that NMFS consider any initial
data from State monitoring efforts, passive acoustic monitoring data,
opportunistic marine mammal sightings data, and other data sources, and
to take steps now to develop a dataset that reflects marine mammal
presence so that it is in hand for future IHA authorizations.
Response: NMFS has used the best available scientific information
in this IHA to inform our determinations. We will review any
recommended data sources and will continue to use the best available
information. We welcome general input on data sources, even outside the
comment period for a particular IHA, may be of use in analyzing the
potential presence and movement patterns of marine mammals, including
North Atlantic right whales, in Mid-Atlantic waters.
Comment 9: The ENGOs recommended that NMFS include more information
on the geographic location and timing of surveys and factor this
information in the take analysis.
Response: NMFS includes as much information in take analyses and in
notices of proposed IHAs on location and seasonality of activities as
is available to us, and has done so in this case.
Comment 10: The ENGOs recommended that all vessels operating within
the survey area, including support vessels, should maintain a speed of
10 knots or less during the entire survey period including those
vessels transiting to/from the survey area.
Response: NMFS has analyzed the potential for ship strike resulting
from Skipjack's activity and has determined that the mitigation
measures specific to ship strike avoidance are sufficient to avoid the
potential for ship strike. These include: A requirement that all vessel
operators comply with 10 knot or less speed restrictions in any
Seasonal Management Area (SMA) or Dynamic Management Area (DMA); a
requirement that all vessel operators reduce vessel speed to 10 knots
or less when any large whale, any mother/calf pairs, pods, or large
assemblages of non-delphinoid cetaceans are observed within 100-m of an
underway vessel; a requirement that all survey vessels maintain a
separation distance of 500-m or greater from any sighted North Atlantic
right whale; a requirement that, if underway, vessels must steer a
course away from any sighted North Atlantic right whale at 10 knots or
less until the 500-m minimum separation distance has been established;
and a requirement that, if a North Atlantic right whale is sighted in a
vessel's path, or within 500-m of an underway vessel, the underway
vessel must reduce speed and shift the engine to neutral. We have
determined that these ship strike avoidance measures are sufficient to
ensure the least practicable adverse impact on species or stocks and
their habitat.
Comment 11: The ENGOs recommended that indirect ship strike risk
resulting from habitat displacement should be accounted for in NMFS'
analysis.
Response: NMFS determined that habitat displacement was not an
expected outcome of the specified activity. As discussed in the notice
of proposed IHA (84 FR 51118; September 27, 2019) we anticipate marine
mammals may temporarily avoid the area of disturbing noise, but this
would be a relatively small area even when multiple vessels are
operating concurrently. The Level B harassment zone was conservatively
estimated to be only 141 m, as described in the Estimated Take section.
Additionally, any potential effects are expected to be short-term,
given the movement of both whales and project vessels and the small
overall area of potential overlap and response. Therefore, habitat
displacement is not reasonably likely to occur.
Comment 12: The ENGOs recommended that NMFS impose a seasonal
restriction on geophysical surveys in the Lease Area from November 1 to
April 30 to reduce potential impacts to North Atlantic right whales.
Response: NMFS appreciates the value of seasonal restrictions under
certain circumstances. However, in this case, we have determined
seasonal restrictions are not warranted. Impacts to right whales from
HRG surveys would be limited to behavioral harassment (i.e., Level B
harassment) in the form of temporary avoidance of the area, responses
that are considered to be of low severity and with no lasting
biological consequences (e.g., Ellison et al., 2012). Based on the best
available information, the highest densities of right whales in the
survey area would be expected from December through March (Roberts et
al., 2018). However, even in those months, densities are relatively low
compared to densities in other areas such as New England (Roberts et
al., 2018). In baseline studies conducted in wind energy areas in the
Mid-Atlantic Outer Continental Shelf from 2012-2014, which included
both aerial and vessel-based surveys, only nine right whales were
observed, all of them south of Skipjack's survey area (Williams et al.,
2015).
In addition, Skipjack has committed to adhering to an agreement
with the ENGOs that stipulates certain mitigation measures. This
written agreement was finalized in 2013 and includes a seasonal
restriction on HRG survey activities during what is referred to as the
``red period'' from November 23 through March 21. Thus, from November
23 through March 21, an effective seasonal closure will be in effect.
For HRG surveys that would occur from November 1 through November 22
and from March 22 through April 30 (referred to as the ``yellow
period'') the agreement also requires that Skipjack submit a risk
assessment report to NMFS and BOEM that analyzes the risk to right
whales from planned survey activities during these periods. This risk
assessment report includes an assessment of the potential for right
whale activity during the planned survey, an acoustic assessment of the
specific equipment to be used, and a site specific Marine Mammal
Harassment Avoidance Plan. As of the writing of this document, Skipjack
has submitted the risk assessment for the period November 1 through
November 22, and would submit a risk assessment report for the period
March 22 through April 30 at a later date, should surveys during that
period be required. NMFS has reviewed the risk assessment report for
the period November 1 through November 22, which includes additional
mitigation measures to those required in the IHA, including enhanced
exclusion zones and pre-clearance times for right whales.
Based on the relatively low densities of right whales in the survey
area from November 1 through April 30, the low risk to right whales
from HRG surveys, the voluntary seasonal closure from November 23
through March 21 that Skipjack has committed to, and the mitigation
measures required in the IHA and the additional mitigation measures
Skipjack has committed to in the NGO agreement, NMFS has determined the
seasonal closures recommended by the commenters are not warranted.
Comment 13: The ENGOs recommended that geophysical surveys should
commence, with ramp up, during daylight hours only to maximize
[[Page 66162]]
the probability that marine mammals are detected and confirmed clear of
the exclusion zone and that if a right whale is detected in the EZ at
night and the survey shuts down, the survey should not resume until
daylight hours.
Response: We acknowledge the limitations inherent in detection of
marine mammals at night. However, similar to the discussion above
regarding time-area closures, restricting the ability of the applicant
to ramp-up surveys only during daylight hours would have the potential
to result in lengthy shutdowns of the survey equipment, which could
result in the applicant failing to collect the data they have
determined is necessary, which could result in the need to conduct
additional surveys the following year. This would result in
significantly increased costs incurred by the applicant. Thus the
restriction suggested by the commenters would not be practicable for
the applicant to implement. In addition, potential impacts to marine
mammals from this survey will be limited to short-term behavioral
responses. Restricting surveys in the manner suggested by the
commenters may reduce marine mammal exposures by some degree in the
short term, but would not result in any significant reduction in either
intensity or duration of noise exposure. No injury is expected to
result even in the absence of mitigation, given the very small
estimated Level A harassment zones. In the event that NMFS imposed the
restriction suggested by the commenters, vessels would potentially be
on the water for a longer period of time. Therefore, in addition to
practicability concerns for the applicant, the restrictions recommended
by the commenters could result in greater overall exposure to sound by
marine mammals. We also note that Skipjack must have at least one PSO
on duty at night per BOEM lease requirements. Thus, the commenters have
not demonstrated that such a requirement would result in a net benefit.
In consideration of potential effectiveness of the recommended measure
and its practicability for the applicant, NMFS has determined that
restricting survey start-ups to daylight hours is not warranted in this
case.
Comment 14: The ENGOs stated that is incumbent upon the agency to
address potential impacts to other endangered and protected whale
species, particularly in light of the UMEs declared for right whales,
humpback whales and minke whales, as well as the several strategic and/
or depleted stocks of small cetaceans that inhabit the region.
Response: NMFS acknowledges the ongoing UMEs for minke whales,
north Atlantic right whales, humpback whales and pinnipeds and we
discuss the potential impacts of Skipjack's surveys on species for
which UMEs have been declared and for which take is authorized in the
Negligible Impact Determination section. Please refer to that
discussion.
Comment 15: The ENGOs recommended that the minimum radii of EZs
should be increased to ensure a 500-m EZ for all marine mammals and an
extended 1,000 m-EZ for North Atlantic right whales. Additionally, the
ENGOs recommended that survey activity should be shut down upon the
visual or acoustic detection of a North Atlantic right whale.
Response: Regarding the recommendation for a 1,000 m EZ
specifically for North Atlantic right whales, we have determined that
the 500-m EZ, as required in the IHA, is sufficiently protective. We
note that the 500-m EZ exceeds--by more than three times--the modeled
distance to the largest Level B harassment isopleth distance (141 m).
Thus, for North Atlantic right whales detected by PSOs, all forms of
incidental take would be avoided. For the same reason, we are not
requiring shutdown if a right whale is observed beyond 500-m.
Similarly, the recommended 500-m EZ for other species is overly
conservative given the 141 m modeled isopleth distance to the Level B
harassment threshold.
Comment 16: The ENGOs recommended that NMFS require all project
vessel operators to report sightings of living North Atlantic right
whales and all sightings of dead, injured, or entangled whales,
regardless of species.
Response: NMFS agrees with the recommendation to report all right
whale sightings to NMFS and has incorporated this requirement in the
IHA. The IHA already includes a requirement to report all observations
of dead, injured, or entangled whales to NMFS.
Comment 17: The ENGOs recommended that a combination of visual
monitoring by PSOs and passive acoustic monitoring (PAM) should be used
at all times.
Response: There are several reasons why we do not think the use of
PAM is warranted. NMFS agrees that PAM can be an important tool for
augmenting detection capabilities in certain circumstances, however,
its utility in further reducing impact for Skipjack's HRG survey
activities is very limited. First, for this activity, the area expected
to be ensonified above the Level B harassment threshold is relatively
small (a maximum of 141 m as described in the Estimated Take section).
PAM is only capable of detecting animals that are actively vocalizing,
while many marine mammal species vocalize infrequently or during
certain activities, which means that only a subset of the animals
within the range of the PAM would be detected (and potentially have
reduced impacts). Additionally, localization and range detection can be
challenging under certain scenarios. For example, odontocetes are fast
moving and often travel in large or dispersed groups which makes
localization difficult. In addition, the ability of PAM to detect
baleen whale vocalizations is further limited due to being deployed
from the stern of a vessel, which puts the PAM hydrophones in proximity
to propeller noise and low frequency engine noise which can mask the
low frequency sounds emitted by baleen whales, including right whales.
Given that the effects to marine mammals from the types of surveys
authorized in this IHA are expected to be limited to low level
behavioral harassment even in the absence of mitigation, the limited
additional benefit anticipated by adding this detection method
(especially for right whales and other low frequency cetaceans), and
the cost and impracticability of implementing a PAM program, we have
determined the current requirements for visual monitoring are
sufficient to ensure the least practicable adverse impact on the
affected species or stocks and their habitat.
Comment 18: The ENGOs commented that the operation of up to three
survey vessels at any one time across a relatively limited geographic
area presents a significant potential for cumulative disturbance during
the North Atlantic right whale's primary migratory period and that NMFS
should analyze the cumulative impacts from Skipjack's survey activities
on North Atlantic right whales and other protected species.
Response: The MMPA grants exceptions to its broad take prohibition
for a ``specified activity.'' 16 U.S.C. 1371(a)(5)(A)(i). Cumulative
impacts (also referred to as cumulative effects) is a term that appears
in the context of NEPA and the ESA, but it is defined differently in
those contexts. Neither the MMPA nor NMFS' codified implementing
regulations address consideration of other unrelated activities and
their impacts on populations. However, the preamble for NMFS'
implementing regulations (54 FR 40338; September 29, 1989) states in
[[Page 66163]]
response to comments that the impacts from other past and ongoing
anthropogenic activities are to be incorporated into the negligible
impact analysis via their impacts on the environmental baseline.
Accordingly, NMFS here has factored into its negligible impact analyses
the impacts of other past and ongoing anthropogenic activities via
their impacts on the baseline (e.g., as reflected in the density/
distribution and status of the species, population size and growth
rate, and other relevant stressors (such as incidental mortality in
commercial fisheries)).
Comment 19: The ENGOs recommended that NMFS fund analyses of
recently collected sighting and acoustic data for all data-holders and
continue to fund and expand surveys and studies to improve our
understanding of distribution and habitat use of marine mammals.
Response: We agree with the ENGOs that analyses of recently
collected sighting and acoustic data, as well as continued marine
mammal surveys, are warranted. We welcome the opportunity to
participate in fora where implications of such data for potential
mitigation measures would be discussed; however, we do not have broad
statutory authority or the ability to require that all ``data-holders''
fund such analyses and surveys. Additionally, NMFS will fund pertinent
surveys based on agency priorities and budgetary considerations.
Changes From the Proposed IHA to Final IHA
As described above, the following additions to reporting
requirements have been incorporated in the IHA based on comments
received during the public comment period:
Vessel operators must report sightings of North Atlantic
right whales to NMFS; and
Marine mammal observational datasheets or raw sightings
data must be provided in the draft and final monitoring report.
Description of Marine Mammals in the Area of Specified Activity
Sections 3 and 4 of the IHA application summarize available
information regarding status and trends, distribution and habitat
preferences, and behavior and life history, of the potentially affected
species. Additional information regarding population trends and threats
may be found in NMFS' Stock Assessment Reports (SARs;
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS'
website (www.fisheries.noaa.gov/find-species).
Table 2 summarizes information related to the population or stock,
including regulatory status under the MMPA and ESA and potential
biological removal (PBR), where known. For taxonomy, we follow
Committee on Taxonomy (2018). PBR is defined by the MMPA as the maximum
number of animals, not including natural mortalities, that may be
removed from a marine mammal stock while allowing that stock to reach
or maintain its optimum sustainable population (as described in NMFS'
SARs). While no mortality is anticipated or authorized here, PBR is
included here as a gross indicator of the status of the species and
other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS' U.S. Atlantic SARs. All values presented in Table 2 are the most
recent available at the time of publication and are available in the
2018 Atlantic SARs (Hayes et al., 2019), available online at:
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region.
Table 2--Marine Mammals Known To Occur in the Survey Area That May Be Affected by Skipjack's Proposed Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
MMPA and ESA Stock abundance
status; (CV, Nmin, most Predicted Annual M/ Expected occurrence
Common name (scientific name) Stock strategic (Y/ recent abundance abundance (CV) PBR \4\ SI \4\ in survey area
N) \1\ survey) \2\ \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Toothed Whales (Odontoceti)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale (Physeter North Atlantic..... E; Y 2,288 (0.28; 1,815; 5,353 (0.12) 3.6 0.8 Rare.
macrocephalus). n/a).
Killer whale (Orcinus orca)..... W North Atlantic... --; N Unknown (n/a; n/a; 11 (0.82) Undet. 0 Rare.
n/a).
Long-finned pilot whale W North Atlantic... --; N 5,636 (0.63; 3,464; \5\ 18,977 (0.11) 35 27 Uncommon.
(Globicephala melas). n/a).
Short-finned pilot whale W North Atlantic... --; N 28,924 (0.24; \5\ 18,977 (0.11) 236 168 Rare.
(Globicephala macrorhynchus). 23,637; n/a).
Atlantic white-sided dolphin W North Atlantic... --; N 48,819 (0.61; 37,180 (0.07) 304 30 Common.
(Lagenorhynchus acutus). 30,403; n/a).
Atlantic spotted dolphin W North Atlantic... --; N 44,715 (0.43; 55,436 (0.32) 316 0 Common.
(Stenella frontalis). 31,610;.
Bottlenose dolphin (Tursiops W North Atlantic --; N 6,639 (0.41; 4,759; \5\ 97,476 (0.06) 48 unknown Common.
truncatus). Coastal Migratory. 2015).
Common dolphin \6\ (Delphinus W North Atlantic... --; N 173,486 (0.55; 86,098 (0.12) 557 406 Common.
delphis). 55,690; 2011).
Risso's dolphin (Grampus W North Atlantic... --; N 18,250 (0.46; 7,732 (0.09) 126 49.9 Rare.
griseus). 12,619; 2011).
Harbor porpoise (Phocoena Gulf of Maine/Bay --; N 79,833 (0.32; * 45,089 (0.12) 706 255 Common.
phocoena). of Fundy. 61,415; 2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 66164]]
Baleen Whales (Mysticeti)
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Atlantic right whale W North Atlantic... E; Y 451 (0; 455; n/a).. \7\ 411 (n/a) 0.9 56 Year round in
(Eubalaena glacialis). continental shelf
and slope waters,
occur seasonally.
Humpback whale \8\ (Megaptera Gulf of Maine...... --; N 896 (0.42; 239; n/ * 1,637 (0.07) 14.6 9.8 Common year round.
novaeangliae). a).
Fin whale \6\ (Balaenoptera W North Atlantic... E; Y 3,522 (0.27; 1,234; 4,633 (0.08) 2.5 2.5 Year round in
physalus). n/a). continental shelf
and slope waters,
occur seasonally.
Sei whale (Balaenoptera Nova Scotia........ E; Y 357 (0.52; 236; n/ * 717 (0.30) 0.5 0.6 Year round in
borealis). a). continental shelf
and slope waters,
occur seasonally.
Minke whale \6\ (Balaenoptera Canadian East Coast --; N 20,741 (0.3; 1,425; * 2,112 (0.05) 14 7.5 Year round in
acutorostrata). n/a). continental shelf
and slope waters,
occur seasonally.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Earless Seals (Phocidae)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray seal \8\ (Halichoerus W North Atlantic... --; N 27,131 (0.10; 505,000 (n/a) 1,389 5,688 Uncommon.
grypus). 25,908; n/a).
Harbor seal (Phoca vitulina).... W North Atlantic... --; N 75,834 (0.15; 75,834 (0.15) 2,006 345 Uncommon.
66,884; 2012).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (--) indicates that the species is not listed under the ESA or
designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR (see
footnote 3) or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ Stock abundance as reported in NMFS marine mammal stock assessment reports (SAR) except where otherwise noted. SARs available online at:
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments. CV is coefficient of variation; Nmin is the minimum estimate
of stock abundance. In some cases, CV is not applicable. For certain stocks, abundance estimates are actual counts of animals and there is no
associated CV. The most recent abundance survey that is reflected in the abundance estimate is presented; there may be more recent surveys that have
not yet been incorporated into the estimate. All values presented here are from the 2018 Atlantic SARs.
\3\ This information represents species- or guild-specific abundance predicted by recent habitat-based cetacean density models (Roberts et al., 2016,
2017, 2018) (with the exception of North Atlantic right whales and pinnipeds--see footnotes 7 and 9 below). These models provide the best available
scientific information regarding predicted density patterns of cetaceans in the U.S. Atlantic Ocean, and we provide the corresponding abundance
predictions as a point of reference. Total abundance estimates were produced by computing the mean density of all pixels in the modeled area and
multiplying by its area. For those species marked with an asterisk (*), the available information supported development of either two or four seasonal
models; each model has an associated abundance prediction. Here, we report the maximum predicted abundance.
\4\ Potential biological removal, defined by the MMPA as the maximum number of animals, not including natural mortalities, that may be removed from a
marine mammal stock while allowing that stock to reach or maintain its optimum sustainable population size (OSP). Annual M/SI, found in NMFS' SARs,
represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial fisheries, subsistence hunting, ship
strike). Annual M/SI values often cannot be determined precisely and is in some cases presented as a minimum value. All M/SI values are as presented
in the 2018 SARs.
\5\ Abundance estimates are in some cases reported for a guild or group of species when those species are difficult to differentiate at sea. Similarly,
the habitat-based cetacean density models produced by Roberts et al. (2016, 2017, 2018) are based in part on available observational data which, in
some cases, is limited to genus or guild in terms of taxonomic definition. Roberts et al. (2016, 2017, 2018) produced density models to genus level
for Globicephala spp. produced density models for bottlenose dolphins that do not differentiate between offshore and coastal stocks, and produced
density models for all seals.
\6\ Abundance as reported in the 2007 Canadian Trans-North Atlantic Sighting Survey (TNASS), which provided full coverage of the Atlantic Canadian coast
(Lawson and Gosselin, 2009). Abundance estimates from TNASS were corrected for perception and availability bias, when possible. In general, where the
TNASS survey effort provided superior coverage of a stock's range (as compared with NOAA shipboard survey effort), the resulting abundance estimate is
considered more accurate than the current NMFS abundance estimate (derived from survey effort with inferior coverage of the stock range). NMFS SAR
reports the stock abundance estimate for the common dolphin as 70,184; NMFS SAR reports the stock abundance estimate for the fin whale as 1,618; NMFS
SAR reports the stock abundance estimate for the minke whale as 2,591.
\7\ For the North Atlantic right whale the best available abundance estimate is derived from the 2018 North Atlantic Right Whale Consortium 2018 Annual
Report Card (Pettis et al., 2018).
\8\ 2018 U.S. Atlantic draft SAR for the Gulf of Maine feeding population lists a current abundance estimate of 896 individuals. However, we note that
the estimate is defined on the basis of feeding location alone (i.e., Gulf of Maine) and is therefore likely an underestimate.
\9\ The NMFS stock abundance estimate applies to U.S. population only, however the actual stock abundance is approximately 505,000.
Four marine mammal species that are listed under the Endangered
Species Act (ESA) may be present in the survey area and are included in
the take request: The North Atlantic right whale, fin whale, sei whale,
and sperm whale. We consulted under section 7 of the ESA with the NMFS
Greater Atlantic Regional Fisheries Office (GARFO) on our authorization
of take for these species; please see the Endangered Species Act
section below.
A detailed description of the species likely to be affected by
Skipjack's surveys, 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 notice of proposed IHA (84 FR 51118; September 27,
2019); 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 notice for these descriptions.
Please also refer to NMFS' website (www.fisheries.noaa.gov/find-species) for generalized species accounts.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The effects of underwater noise from Skipjack's survey activities
have the potential to result in behavioral harassment of marine mammals
in the vicinity of the survey area. The notice of proposed IHA (84 FR
51118; September 27, 2019) included a discussion of the effects of
anthropogenic noise on marine mammals and the potential effects of
underwater noise from Skipjack's survey activities on marine mammals
and their habitat. That information and
[[Page 66165]]
analysis is incorporated by reference into this final IHA determination
and is not repeated here; please refer to the notice of proposed IHA
(84 FR 51118; September 27, 2019).
Estimated Take
This section provides an estimate of the number of incidental takes
authorized through this IHA, which will inform both NMFS' consideration
of ``small numbers'' and the negligible impact determination.
Level B 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 are by Level B harassment only. Based on the
nature of the activity and the anticipated effectiveness of the
mitigation measures (i.e., exclusion zones and shutdown measures),
discussed in detail below in 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.
Generally speaking, we estimate take by considering: (1) Acoustic
thresholds above which NMFS believes the best available science
indicates marine mammals will be behaviorally harassed or incur some
degree of permanent hearing impairment; (2) the area or volume of water
that will be ensonified above these levels in a day; (3) the density or
occurrence of marine mammals within these ensonified areas; and, (4)
and the number of days of activities. We note that while these basic
factors can contribute to a basic calculation to provide an initial
prediction of takes, additional information that can qualitatively
inform take estimates is also sometimes available (e.g., previous
monitoring results or average group size). Below, we describe the
factors considered here in more detail and present the take estimate.
Acoustic Thresholds
Using the best available science, NMFS has developed acoustic
thresholds that identify the received level of underwater sound above
which exposed marine mammals would be reasonably expected to be
behaviorally harassed (equated to Level B harassment) or to incur PTS
of some degree (equated to Level A harassment).
Level B Harassment--Though significantly driven by received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source (e.g., frequency, predictability, duty cycle), the environment
(e.g., bathymetry), and the receiving animals (hearing, motivation,
experience, demography, behavioral context) and can be difficult to
predict (Southall et al., 2007, Ellison et al., 2012). Based on what
the available science indicates and the practical need to use a
threshold based on a factor that is both predictable and measurable for
most activities, NMFS uses a generalized acoustic threshold based on
received level to estimate the onset of behavioral harassment. NMFS
predicts that marine mammals are likely to be behaviorally harassed in
a manner we consider Level B harassment when exposed to underwater
anthropogenic noise above received levels of 160 dB re 1 [mu]Pa (rms)
for impulsive and/or intermittent sources (e.g., impact pile driving)
and 120 dB rms for continuous sources (e.g., vibratory driving).
Skipjack's planned activity includes the use of impulsive sources
(geophysical survey equipment) therefore use of the 120 and 160 dB re 1
[mu]Pa (rms) threshold is applicable.
Level A harassment--NMFS' Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0)
(Technical Guidance, 2018) identifies dual criteria to assess auditory
injury (Level A harassment) to five different marine mammal groups
(based on hearing sensitivity) as a result of exposure to noise from
two different types of sources (impulsive or non-impulsive). The
components of Skipjack's planned activity that may result in the take
of marine mammals include the use of impulsive sources.
These thresholds are provided in Table 3 below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS 2018 Technical Guidance, which may be accessed at:
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 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 [micro]Pa, and cumulative sound exposure level (LE)
has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
[[Page 66166]]
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that will feed into identifying the area ensonified above the
acoustic thresholds, which include source levels and transmission loss
coefficient.
The survey would entail the use of HRG equipment. The distance to
the isopleth corresponding to the threshold for Level B harassment was
calculated for all HRG equipment with the potential to result in
harassment of marine mammals. NMFS has developed an interim methodology
for determining the rms sound pressure level (SPLrms) at the
160-dB isopleth for the purposes of estimating take by Level B
harassment resulting from exposure to HRG survey equipment. This
methodology incorporates frequency and some directionality to refine
estimated ensonified zones and is described below:
If only peak source sound pressure level (SPLpk) is
given, the SPLrms can be roughly approximated by
[GRAPHIC] [TIFF OMITTED] TN03DE19.002
where [tau] is the pulse duration in seconds. If the pulse duration
varies, the longest duration should be used, unless there is certainty
regarding the portion of time a shorter duration will be used, in which
case the result can be calculated/parsed appropriately.
In order to account for the greater absorption of higher frequency
sources, we apply 20 log(r) with an absorption term [alpha][middot]r/
1000 to calculate transmission loss (TL), as described in Eq.s (2) and
(3) below.
[GRAPHIC] [TIFF OMITTED] TN03DE19.003
where r is the distance in meters, and [alpha] is absorption
coefficient in dB/km.
While the calculation of absorption coefficient varies with
frequency, temperature, salinity, and pH, the largest factor driving
the absorption coefficient is frequency. A simple formula to
approximate the absorption coefficient (neglecting temperature,
salinity, and pH) is provided by Richardson et al. (1995):
[GRAPHIC] [TIFF OMITTED] TN03DE19.004
where f is frequency in kHz. When a range of frequencies, is being
used, the lower bound of the range should be used for this calculation,
unless there is certainty regarding the portion of time a higher
frequency will be used, in which case the result can be calculated/
parsed appropriately.
Further, if the beamwidth is less than 180[deg] and the angle of
beam axis in respect to sea surface is known, the horizontal impact
distance R should be calculated using
[GRAPHIC] [TIFF OMITTED] TN03DE19.005
where SL is the SPLrms at the source (1 m), [thgr] is the
beamwidth (in radian), and [phi] is the angle of beam axis in respect
to sea surface (in radian)
Finally, if the beam is pointed at a normal downward direction, Eq.
(4) can be simplified as
[GRAPHIC] [TIFF OMITTED] TN03DE19.006
The interim methodology described above was used to estimate
isopleth distances to the Level B harassment threshold for the proposed
HRG survey. NMFS considers the data provided by Crocker and Fratantonio
(2016) to represent the best available information on source levels
associated with HRG equipment and therefore recommends that source
levels provided by Crocker and Fratantonio (2016) be incorporated in
the method described above to estimate isopleth distances to the Level
B harassment threshold. In cases when the source level for a specific
type of HRG equipment is not provided in Crocker and Fratantonio
(2016), NMFS recommends that either the source levels provided by the
manufacturer be used, or, in instances where source levels provided by
the manufacturer are unavailable or unreliable, a proxy from Crocker
and Fratantonio (2016) be used instead. Table 1 shows the HRG equipment
types that may be used during the proposed surveys and the sound levels
associated with those HRG equipment types. Table 4 in the IHA
application shows the literature sources for the sound source levels
that are shown in Table 1 and that were incorporated into the modeling
of isopleth distances to the Level B harassment threshold.
Results of modeling using the methodology described above indicated
that, of the HRG survey equipment planned for use by Skipjack that has
the potential to result in harassment of marine mammals, sound produced
by the AA Dura-Spark 400 sparker and the GeoSource 800 J sparker would
propagate furthest to the Level B harassment threshold (Table 4);
therefore, for the purposes of the exposure analysis, it was assumed
the AA Dura-Spark or the GeoSource 800 J would be active during the
entirety of
[[Page 66167]]
the survey. Thus the distance to the isopleth corresponding to the
threshold for Level B harassment for the AA Dura-Spark 400 and the
GeoSource 800 J (estimated at 141 m; Table 4) was used as the basis of
the take calculation for all marine mammals. Note that this is
conservative as Skipjack has stated that for approximately 120 of the
200 total survey days, neither the AA Dura-Spark nor the GeoSource 800
J would be operated, and the sources with smaller associated isopleth
distances to the Level B harassment threshold would be used (Table 4).
Table 4--Modeled Radial Distances From HRG Survey Equipment to Isopleths Corresponding to Level A Harassment and
Level B Harassment Thresholds
----------------------------------------------------------------------------------------------------------------
Radial distance to Level A harassment threshold (m) * Radial
---------------------------------------------------------------- distance to
Level B
Low frequency Mid frequency High Phocid harassment
Sound source cetaceans cetaceans frequency pinnipeds threshold (m)
(peak SPL/ (peak SPL/ cetaceans (underwater) ---------------
SELcum) SELcum) (peak SPL/ (peak SPL/ All marine
SELcum) SELcum) mammals
----------------------------------------------------------------------------------------------------------------
Shallow Sub-bottom Profilers
----------------------------------------------------------------------------------------------------------------
TB Chirp III.................... -/<1 0 -/<1 -/<1 48
ET 216 Chirp.................... -/<1 -/0 -/<1 -/0 9
ET 424 Chirp.................... -/0 -/0 -/0 -/0 4
ET 512i Chirp................... -/0 -/0 -/0 -/0 6
GeoPulse 5430................... -/<1 -/0 -/<1 -/0 21
----------------------------------------------------------------------------------------------------------------
Parametric Sub-bottom Profilers
----------------------------------------------------------------------------------------------------------------
Innomar Parametric SBPs......... -/<1 -/<1 -/1.2 -/<1 1
----------------------------------------------------------------------------------------------------------------
Medium Sub-bottom Profilers
----------------------------------------------------------------------------------------------------------------
AA Triple plate S-Boom (700/ -/<1 -/0 2.8/0 -/0 34
1000J).........................
AA Dura-Spark 400............... -/<1 -/0 2.8/0 -/0 141
GeoSource 400 J Sparker......... -/<1 -/0 2.0/0 -/0 56
GeoSource 600 J Sparker......... -/<1 -/0 3.2/<1 -/<1 112
GeoSource 800 J Sparker......... -/<1 -/0 3.5/<1 -/<1 141
----------------------------------------------------------------------------------------------------------------
Acoustic Corers
----------------------------------------------------------------------------------------------------------------
Pangeo Acoustic Corer (LF Chirp) -/<1 -/0 -/<1 -/0 4
Pangeo Acoustic Corer (HF Chirp) -/<1 -/0 -/<1 -/0 4
----------------------------------------------------------------------------------------------------------------
Acoustic Positioning
----------------------------------------------------------------------------------------------------------------
USBL and GAPS (all models)...... -/0 -/0 -/<1 -/0 50
----------------------------------------------------------------------------------------------------------------
* Distances to Level A harassment isopleths were calculated to determine the potential for Level A harassment to
occur. Skipjack has not requested, and NMFS does not propose to authorize, the take by Level A harassment of
any marine mammals.
- = not applicable; AA = Applied Acoustics; CF = Crocker and Fratantonio (2016); ET = EdgeTech; GAPS = Global
Acoustic Positioning System; HF = high-frequency; J = joules; LF = low-frequency; m = meter; MF = mid-
frequency; PW = Phocids in water; SBP = Sub-bottom profilers; SELcum = cumulative sound exposure level; SL =
source level; SPLpk = zero to peak sound pressure level in decibel referenced to 1 micropascal (dB re 1
[micro]Pa); TB = teledyne benthos; USBL = ultra-short baseline.
Predicted distances to Level A harassment isopleths, which vary
based on marine mammal functional hearing groups (Table 4), were also
calculated. The updated acoustic thresholds for impulsive sounds (such
as HRG survey equipment) contained in the Technical Guidance (NMFS,
2018) were presented as dual metric acoustic thresholds using both
cumulative sound exposure level (SELcum) and peak sound
pressure level metrics. As dual metrics, NMFS considers onset of PTS
(Level A harassment) to have occurred when either one of the two
metrics is exceeded (i.e., the metric resulting in the largest
isopleth). The SELcum metric considers both level and
duration of exposure, as well as auditory weighting functions by marine
mammal hearing group.
When the NMFS Technical Guidance (2016) was published, in
recognition of the fact that ensonified area/volume could be more
technically challenging to predict because of the duration component in
the new thresholds, we developed a User Spreadsheet that includes tools
to help predict a simple isopleth that can be used in conjunction with
marine mammal density or occurrence to help predict takes. We note that
because of some of the assumptions included in the methods used for
these tools, we anticipate that isopleths produced typically
overestimate Level A harassment. 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 HRG surveys),
the User Spreadsheet predicts the closest distance at which a
stationary animal would incur PTS if the sound source traveled by the
animal in a straight line at a constant speed.
Skipjack used the NMFS optional User Spreadsheet to calculate
distances to Level A harassment isopleths based on SEL and used the
spherical spreading loss model to calculate distances to Level A
harassment
[[Page 66168]]
isopleths based on peak SPL. Modeling of distances to isopleths
corresponding to Level A harassment was performed for all types of HRG
equipment proposed for use with the potential to result in harassment
of marine mammals. Isopleth distances to Level A harassment thresholds
for all types of HRG equipment and all marine mammal functional hearing
groups are shown in Table 4. To be conservative, the largest isopleth
distances for each functional hearing group were used to model
potential exposures above the Level A harassment threshold for all
species within that functional hearing group. Inputs to the NMFS
optional User Spreadsheet for the GeoSource 800 J Sparker, which
resulted in the greatest potential isopleth distance to the Level A
harassment threshold for any of the functional hearing groups, are
shown in Table 5.
Table 5--Inputs to the NMFS Optional User Spreadsheet for GeoSource 800
J Sparker
------------------------------------------------------------------------
------------------------------------------------------------------------
Source Level (RMS SPL)................. 203 dB re 1[mu]Pa.
Source Level (peak).................... 213 dB re 1[mu]Pa.
Weighting Factor Adjustment (kHz)...... 0.05.
Source Velocity (meters/second)........ 2.06.
Pulse Duration (seconds)............... 0.0034.
1/Repetition rate (seconds)............ 2.43.
Duty Cycle............................. 0.00.
------------------------------------------------------------------------
Due to the small estimated distances to Level A harassment
thresholds for all marine mammal functional hearing groups, based on
both SELcum and peak SPL (Table 4), and in consideration of
the mitigation measures (see the Mitigation section for more detail),
NMFS has determined that the likelihood of take of marine mammals in
the form of Level A harassment occurring as a result of the survey is
so low as to be discountable, and we therefore do not authorize the
take by Level A harassment of any marine mammals.
Marine Mammal Occurrence
In this section we provide the information about the presence,
density, or group dynamics of marine mammals that will inform the take
calculations.
The habitat-based density models produced by the Duke University
Marine Geospatial Ecology Laboratory (Roberts et al., 2016, 2017, 2018)
represent the best available information regarding marine mammal
densities in the survey area. The density data presented by Roberts et
al. (2016, 2017, 2018) incorporates aerial and shipboard line-transect
survey data from NMFS and other organizations and incorporates data
from 8 physiographic and 16 dynamic oceanographic and biological
covariates, and controls for the influence of sea state, group size,
availability bias, and perception bias on the probability of making a
sighting. These density models were originally developed for all
cetacean taxa in the U.S. Atlantic (Roberts et al., 2016). In
subsequent years, certain models have been updated on the basis of
additional data as well as certain methodological improvements.
Although these updated models (and a newly developed seal density
model) are not currently publicly available, our evaluation of the
changes leads to a conclusion that these represent the best scientific
evidence available. More information, including the model results and
supplementary information for each model, is available online at
seamap.env.duke.edu/models/Duke-EC-GOM-2015/. Marine mammal density
estimates in the project area (animals/km\2\) were obtained using these
model results (Roberts et al., 2016, 2017, 2018). The updated models
incorporate additional sighting data, including sightings from the NOAA
Atlantic Marine Assessment Program for Protected Species (AMAPPS)
surveys from 2010-2014 (NEFSC & SEFSC, 2011, 2012, 2014a, 2014b, 2015,
2016).
For purposes of the exposure analysis, density data from Roberts et
al. (2016, 2017, 2018) were mapped using a geographic information
system (GIS). The density coverages that included any portion of the
survey area were selected for all survey months (see Figure 4 in the
IHA application for an example of density blocks used to determine
monthly marine mammal densities within the project area). Monthly
density data for each species were then averaged over the year to come
up with a mean annual density value for each species. Estimated monthly
and average annual density (animals per km\2\) of all marine mammal
species that may be taken by the survey are shown in Table 8 of the IHA
application. The mean annual density values used to estimate take
numbers are also shown in Table 6 below.
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate.
In order to estimate the number of marine mammals predicted to be
exposed to sound levels that would result in harassment, radial
distances to predicted isopleths corresponding to harassment thresholds
are calculated, as described above. Those distances are then used to
calculate the area(s) around the HRG survey equipment predicted to be
ensonified to sound levels that exceed harassment thresholds. The area
estimated to be ensonified to relevant thresholds in a single day is
then calculated, based on areas predicted to be ensonified around the
HRG survey equipment and the estimated trackline distance traveled per
day by the survey vessel. Skipjack estimates that planned surveys will
achieve a maximum daily track line distance of 110 km per day during
planned HRG surveys. This distance accounts for the vessel traveling at
roughly 4 knots and accounts for non-active survey periods. Based on
the maximum estimated distance to the Level B harassment threshold of
141 m (Table 4) and the maximum estimated daily track line distance of
110 km, an area of 31.1 km\2\ would be ensonified to the Level B
harassment threshold per day during Skipjack's planned HRG surveys. As
described above, this is a conservative estimate as it assumes the HRG
sources that result in the greatest isopleth distances to the Level B
harassment threshold would be operated at all times during the 200 day
survey.
The number of marine mammals expected to be incidentally taken per
day is then calculated by estimating the number of each species
predicted to occur within the daily ensonified area (animals/km\2\),
incorporating the estimated marine mammal densities as described above.
Estimated numbers of each species taken per day are then multiplied by
the total number of survey days (i.e., 200). The product is then
rounded, to generate an estimate of the total number of instances of
harassment expected for each species over the duration of the survey. A
summary of this method is illustrated in the following formula:
Estimated Take = D x ZOI x # of days
Where:
D = average species density (per km\2\) and ZOI = maximum daily
ensonified area to relevant thresholds.
Using this method to calculate take, Skipjack estimated a total of
2 takes by Level A harassment of 1 species (harbor porpoise) would
occur, in the absence of mitigation (see Table 9 in the IHA application
for the estimated number of Level A takes for all potential HRG
equipment types). However, as described above, due to the very small
estimated distances to Level A harassment thresholds (Table 4), and in
consideration of the mitigation measures, the likelihood of the survey
resulting in take in the form of Level A harassment is considered so
low as to be discountable; therefore, we do not
[[Page 66169]]
propose to authorize take of any marine mammals by Level A harassment.
Authorized take numbers are shown in Table 6.
Table 6--Total Numbers of Potential Incidental Take of Marine Mammals Authorized and Authorized Takes as a Percentage of Population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total
Density Authorized Estimated Authorized authorized
Species (animals/100 takes by Level takes by Level takes by Level Total takes takes as a
km\2\) A harassment B harassment B harassment authorized percentage of
population \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Fin whale............................................... 0.00124 0 8 8 8 0.2
Sei whale \2\........................................... 0.00001 0 0 1 1 0.1
Minke whale............................................. 0.00034 0 2 2 2 0.1
Humpback whale.......................................... 0.00053 0 3 3 3 0.2
North Atlantic right whale.............................. 0.00043 0 3 3 3 0.7
Sperm Whale \2\......................................... 0.00004 0 0 3 3 0.1
Atlantic white-sided dolphin \2\........................ 0.00229 0 14 40 40 0.1
Atlantic spotted dolphin \2\............................ 0.00124 0 8 100 100 0.2
Bottlenose dolphin (W. N. Atlantic Coastal Migratory)... 0.2355 0 1,465 1,465 1,465 22.1
Killer whale \2\........................................ 0.00001 0 0 3 3 27.3
Short-finned pilot whale \2\............................ 0.00031 0 2 20 20 0.1
Long-finned pilot whale \2\............................. 0.00031 0 2 20 20 0.1
Risso's dolphin \2\..................................... 0 0 0 30 30 0.4
Common dolphin.......................................... 0.01328 0 83 83 83 0.1
Harbor porpoise......................................... 0.01277 0 79 79 79 0.2
Gray seal............................................... 0.00072 0 4 4 4 0.0
Harbor seal............................................. 0.00072 0 4 4 4 0.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Calculations of percentage of stock taken are based on the best available abundance estimate as shown in Table 2. In most cases the best available
abundance estimate is provided by Roberts et al. (2016, 2017, 2018), when available, to maintain consistency with density estimates derived from
Roberts et al. (2016, 2017, 2018). For North Atlantic right whales the best available abundance estimate is derived from the 2018 North Atlantic Right
Whale Consortium 2018 Annual Report Card (Pettis et al., 2018).
\2\ The number of authorized takes (Level B harassment only) for these species has been increased from the estimated take number to mean group size.
Source for group size estimates are as follows: Sei whale: Kenney and Vigness-Raposa (2010); sperm whale: Barkaszi and Kelly (2019); killer whale: de
Bruyn et al. (2013); Risso's dolphin: Kenney and Vigness-Raposa (2010); long-finned and short-finned pilot whale: Olson (2018); Atlantic spotted
dolphin: Herzing and Perrin (2018); Atlantic white-sided dolphin: Cipriano (2018).
Skipjack requested take authorization for three marine mammal
species for which no takes were calculated based on the modeling
approach described above: Killer whale, sei whale and Risso's dolphin.
Though the modeling resulted in estimates of less than 1 take for these
species, Skipjack determined that take of these species is possible due
to low densities in some density blocks and general variability in the
movements of these species. NMFS believes this is reasonable and we
therefore authorize take of these species.
As described above, Roberts et al. (2016, 2017, 2018) produced
density models to genus level for Globicephala spp. and did not
differentiate between long-finned and shortfinned pilot whales.
Similarly, Roberts et al. (2018) produced density models for all seals
and did not differentiate by seal species. The take calculation
methodology as described above resulted in an estimate of 2 pilot whale
takes and 4 seal takes. Based on this estimate, Skipjack requested 2
takes each of short-finned and long-finned pilot whales, and 4 takes
each of harbor and gray seals, based on an assumption that the modeled
takes could occur to either of the respective species. We think this is
a reasonable approach and therefore authorize the take of 4 harbor
seals, 4 gray seals, 2 short-finned pilot whales and 2 long-finned
pilot whales.
Using the take methodology approach described above, the take
estimates for the sei whale, sperm whale, killer whale, Risso's
dolphin, Atlantic white-sided dolphin, spotted dolphin, long-finned and
short-finned pilot whale were less than the average group sizes
estimated for these species (Table 6). However, information on the
social structures of these species indicates these species are likely
to be encountered in groups. Therefore it is reasonable to
conservatively assume that one group of each of these species will be
taken during the survey. We therefore authorize the take of the average
group size for these species to account for the possibility that the
survey encounters a group of any of these species or stocks (Table 6).
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,
[[Page 66170]]
scope, range). It further considers the likelihood that the measure
will be effective if implemented (probability of accomplishing the
mitigating result if implemented as planned), the likelihood of
effective implementation (probability implemented as planned), and;
(2) the practicability of the measures for applicant
implementation, which may consider such things as cost, impact on
operations, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
Mitigation Measures
The following mitigation measures must be implemented during
Skipjack's site characterization surveys.
Marine Mammal Exclusion Zones, Buffer Zone and Monitoring Zone
Marine mammal exclusion zones (EZ) must be established around the
HRG survey equipment and monitored by protected species observers (PSO)
during HRG surveys as follows:
A 500-m EZ for North Atlantic right whales;
A 200 m EZ for all other ESA-listed marine mammals (i.e.,
fin, sei and sperm whales), and
A 100-m EZ for all other marine mammals.
If a marine mammal is detected approaching or entering the EZs
during the survey, the vessel operator would adhere to the shutdown
procedures described below. In addition to the EZs described above,
PSOs must visually monitor a 200-m Buffer Zone. During use of acoustic
sources with the potential to result in marine mammal harassment (i.e.,
anytime the acoustic source is active, including ramp-up), occurrences
of marine mammals within the Buffer Zone (but outside the EZs) must be
communicated to the vessel operator to prepare for potential shutdown
of the acoustic source. The Buffer Zone is not applicable when the EZ
is greater than 100 m. PSOs are required to observe a 500-m Monitoring
Zone and record the presence of all marine mammals within this zone. In
addition, any marine mammals observed within 141 m of the HRG equipment
must be documented by PSOs as taken by Level B harassment. The zones
described above must be based upon the radial distance from the active
equipment (rather than being based on distance from the vessel itself).
Visual Monitoring
A minimum of one NMFS-approved PSO must be on duty and conducting
visual observations at all times during daylight hours (i.e., from 30
minutes prior to sunrise through 30 minutes following sunset) and 30
minutes prior to and during nighttime ramp-ups of HRG equipment. Visual
monitoring must begin no less than 30 minutes prior to ramp-up of HRG
equipment and must continue until 30 minutes after use of the acoustic
source ceases or until 30 minutes past sunset. PSOs must establish and
monitor the applicable EZs, Buffer Zone and Monitoring Zone as
described above. Visual PSOs must coordinate to ensure 360[deg] visual
coverage around the vessel from the most appropriate observation posts,
and must conduct visual observations using binoculars and the naked eye
while free from distractions and in a consistent, systematic, and
diligent manner. PSOs must estimate distances to marine mammals located
in proximity to the vessel and/or relevant using range finders. It is
the responsibility of the Lead PSO on duty to communicate the presence
of marine mammals as well as to communicate and enforce the action(s)
that are necessary to ensure mitigation and monitoring requirements are
implemented as appropriate. Position data must be recorded using hand-
held or vessel global positioning system (GPS) units for each confirmed
marine mammal sighting.
Pre-Clearance of the Exclusion Zones
Prior to initiating HRG survey activities, Skipjack must implement
a 30-minute pre-clearance period. During pre-clearance monitoring
(i.e., before ramp-up of HRG equipment begins), the Buffer Zone must
also act as an extension of the 100 m EZ in that observations of marine
mammals within the 200 m Buffer Zone also precludes HRG operations from
beginning. During this period, PSOs must ensure that no marine mammals
are observed within 200 m of the survey equipment (500 m in the case of
North Atlantic right whales). HRG equipment must not start up until
this 200 m zone (or, 500 m zone in the case of North Atlantic right
whales) is clear of marine mammals for at least 30 minutes. The vessel
operator must notify a designated PSO of the planned start of HRG
survey equipment as agreed upon with the lead PSO; the notification
time must not be less than 30 minutes prior to the planned initiation
of HRG equipment order to allow the PSOs time to monitor the EZs and
Buffer Zone for the 30 minutes of pre-clearance. A PSO conducting pre-
clearance observations must be notified again immediately prior to
initiating active HRG sources.
If a marine mammal is observed within the relevant EZs or Buffer
Zone during the pre-clearance period, initiation of HRG survey
equipment must not begin until the animal(s) has been observed exiting
the respective EZ or Buffer Zone, or, until an additional time period
has elapsed with no further sighting (i.e., minimum 15 minutes for
small odontocetes and seals, and 30 minutes for all other species). The
pre-clearance requirement must include small delphinoids that approach
the vessel (e.g., bow ride). PSOs must also continue to monitor the
zone for 30 minutes after survey equipment is shut down or survey
activity has concluded.
Ramp-Up of Survey Equipment
When technically feasible, a ramp-up procedure must be used for
geophysical survey equipment capable of adjusting energy levels at the
start or re-start of survey activities. The ramp-up procedure should be
used at the beginning of HRG survey activities in order to provide
additional protection to marine mammals near the survey area by
allowing them to detect the presence of the survey and vacate the area
prior to the commencement of survey equipment operation at full power.
Ramp-up of the survey equipment must not begin until the relevant EZs
and Buffer Zone has been cleared by the PSOs, as described above. HRG
equipment must be initiated at their lowest power output and would be
incrementally increased to full power. If any marine mammals are
detected within the EZs or Buffer Zone prior to or during ramp-up, the
HRG equipment must be shut down (as described below).
Shutdown Procedures
If an HRG source is active and a marine mammal is observed within
or entering a relevant EZ (as described above) an immediate shutdown of
the HRG survey equipment is required. When shutdown is called for by a
PSO, the acoustic source must be immediately deactivated and any
dispute resolved only following deactivation. Any PSO on duty will have
the authority to delay the start of survey operations or to call for
shutdown of the acoustic source if a marine mammal is detected within
the applicable EZ. The vessel operator must establish and maintain
clear lines of communication directly between PSOs on duty and crew
controlling the HRG source(s) to ensure that shutdown commands are
conveyed swiftly while
[[Page 66171]]
allowing PSOs to maintain watch. Subsequent restart of the HRG
equipment must only occur after the marine mammal has either been
observed exiting the relevant EZ, or, until an additional time period
has elapsed with no further sighting of the animal within the relevant
EZ (i.e., 15 minutes for small odontocetes and seals, and 30 minutes
for large whales).
Upon implementation of shutdown, the HRG source must be reactivated
after the marine mammal that triggered the shutdown has been observed
exiting the applicable EZ (i.e., the animal is not required to fully
exit the Buffer Zone where applicable), or, following a clearance
period of 15 minutes for small odontocetes and seals and 30 minutes for
all other species with no further observation of the marine mammal(s)
within the relevant EZ. If the HRG equipment shuts down for brief
periods (i.e., less than 30 minutes) for reasons other than mitigation
(e.g., mechanical or electronic failure) the equipment may be re-
activated as soon as is practicable at full operational level, without
30 minutes of pre-clearance, only if PSOs have maintained constant
visual observation during the shutdown and no visual detections of
marine mammals occurred within the applicable EZs and Buffer Zone
during that time. For a shutdown of 30 minutes or longer, or if visual
observation was not continued diligently during the pause, pre-
clearance observation is required, as described above.
The shutdown requirement is waived for certain genera of small
delphinids (i.e., Delphinus, Lagenorhynchus, Stenella, and Tursiops)
under certain circumstances. If a delphinid(s) from these genera is
visually detected approaching the vessel (i.e., to bow ride) or towed
survey equipment, shutdown is not required. If there is uncertainty
regarding identification of a marine mammal species (i.e., whether the
observed marine mammal(s) belongs to one of the delphinid genera for
which shutdown is waived), PSOs must use best professional judgment in
making the decision to call for a shutdown.
If a species for which authorization has not been granted, or, a
species for which authorization has been granted but the authorized
number of takes have been met, approaches or is observed within the
area encompassing the Level B harassment isopleth (141 m), shutdown
must occur.
Vessel Strike Avoidance
Vessel strike avoidance measures include, but are not be limited
to, the following, except under circumstances when complying with these
requirements would put the safety of the vessel or crew at risk:
All vessel operators and crew will maintain vigilant watch
for cetaceans and pinnipeds, and slow down or stop their vessel to
avoid striking these protected species;
All vessel operators will comply with 10 knot (18.5 km/hr)
or less speed restrictions in any SMA and DMA per NOAA guidance;
All vessel operators will reduce vessel speed to 10 knots
(18.5 km/hr) or less when any large whale, any mother/calf pairs, large
assemblages of non-delphinoid cetaceans are observed near (within 100 m
(330 ft)) an underway vessel;
All survey vessels will maintain a separation distance of
500 m (1640 ft) or greater from any sighted North Atlantic right whale;
If underway, vessels must steer a course away from any
sighted North Atlantic right whale at 10 knots (18.5 km/hr) or less
until the 500 m (1640 ft) minimum separation distance has been
established. If a North Atlantic right whale is sighted in a vessel's
path, or within 100 m (330 ft) to an underway vessel, the underway
vessel must reduce speed and shift the engine to neutral. Engines will
not be engaged until the North Atlantic right whale has moved outside
of the vessel's path and beyond 100 m. If stationary, the vessel must
not engage engines until the North Atlantic right whale has moved
beyond 100 m;
All vessels will maintain a separation distance of 100 m
(330 ft) or greater from any sighted non-delphinoid cetacean. If
sighted, the vessel underway must reduce speed and shift the engine to
neutral, and must not engage the engines until the non-delphinoid
cetacean has moved outside of the vessel's path and beyond 100 m. If a
survey vessel is stationary, the vessel will not engage engines until
the non-delphinoid cetacean has moved out of the vessel's path and
beyond 100 m;
All vessels will maintain a separation distance of 50 m
(164 ft) or greater from any sighted delphinoid cetacean. Any vessel
underway remain parallel to a sighted delphinoid cetacean's course
whenever possible, and avoid excessive speed or abrupt changes in
direction. Any vessel underway reduces vessel speed to 10 knots (18.5
km/hr) or less when pods (including mother/calf pairs) or large
assemblages of delphinoid cetaceans are observed. Vessels may not
adjust course and speed until the delphinoid cetaceans have moved
beyond 50 m and/or the abeam of the underway vessel;
All vessels will maintain a separation distance of 50 m
(164 ft) or greater from any sighted pinniped; and
All vessels underway will not divert or alter course in
order to approach any whale, delphinoid cetacean, or pinniped. Any
vessel underway will avoid excessive speed or abrupt changes in
direction to avoid injury to the sighted cetacean or pinniped.
Skipjack must ensure that vessel operators and crew maintain a
vigilant watch for marine mammals by slowing down or stopping the
vessel to avoid striking marine mammals. Project-specific training will
be conducted for all vessel crew prior to the start of survey
activities. Confirmation of the training and understanding of the
requirements will be documented on a training course log sheet. Signing
the log sheet will certify that the crew members understand and will
comply with the necessary requirements throughout the survey
activities.
Seasonal Operating Requirements
A section of the planned survey area partially overlaps with a
portion of a North Atlantic right whale SMA off the mouth of Delaware
Bay. This SMA is active from November 1 through April 30 of each year.
Any survey vessels that are >65 ft in length is required to adhere to
the mandatory vessel speed restrictions (<10 kn) when operating within
the SMA during times when the SMA is active. In addition, between watch
shifts, members of the monitoring team must consult NMFS' North
Atlantic right whale reporting systems for the presence of North
Atlantic right whales throughout survey operations. Members of the
monitoring team must also monitor the NMFS North Atlantic right whale
reporting systems for the establishment of Dynamic Management Areas
(DMA). If NMFS should establish a DMA in the survey area while surveys
are underway, Skipjack must contact NMFS within 24 hours of the
establishment of the DMA to determine whether alteration of survey
activities was warranted to avoid right whales to the extent possible.
The mitigation measures are designed to avoid the already low
potential for injury in addition to some instances of Level B
harassment, and to minimize the potential for vessel strikes. Further,
we believe the mitigation measures are practicable for the applicant to
implement. Skipjack has proposed additional mitigation measures in
addition to the measures described above; for information on the
measures proposed by Skipjack, see Section 11 of the IHA application.
[[Page 66172]]
There are no known marine mammal rookeries or mating or calving
grounds in the survey area that would otherwise potentially warrant
increased mitigation measures for marine mammals or their habitat (or
both). The survey would occur in an area that has been identified as a
biologically important area for migration for North Atlantic right
whales. However, given the small spatial extent of the survey area
relative to the substantially larger spatial extent of the right whale
migratory area, the survey is not expected to appreciably reduce
migratory habitat nor to negatively impact the migration of North
Atlantic right whales, thus mitigation to address the planned survey's
occurrence in North Atlantic right whale migratory habitat is not
warranted.
Based on our evaluation of the applicant's proposed measures, as
well as other measures considered by NMFS, NMFS has determined that the
mitigation measures provide the means of 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
survey area. Effective reporting is critical both to compliance as well
as ensuring that the most value is obtained from the required
monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density).
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas).
Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors.
How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks.
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat).
Mitigation and monitoring effectiveness.
Monitoring Measures
As described above, visual monitoring must be performed by
qualified and NMFS-approved PSOs. Skipjack must use independent,
dedicated, trained PSOs, meaning that the PSOs must be employed by a
third-party observer provider, must have no tasks other than to conduct
observational effort, collect data, and communicate with and instruct
relevant vessel crew with regard to the presence of marine mammals and
mitigation requirements (including brief alerts regarding maritime
hazards), and must have successfully completed an approved PSO training
course appropriate for their designated task. Skipjack must provide
resumes of all proposed PSOs (including alternates) to NMFS for review
and approval at least 45 days prior to the start of survey operations.
During survey operations (e.g., any day on which use of an HRG
source is planned to occur), a minimum of one PSO must be on duty and
conducting visual observations at all times on all active survey
vessels during daylight hours (i.e., from 30 minutes prior to sunrise
through 30 minutes following sunset) and nighttime ramp-ups of HRG
equipment. Visual monitoring must begin no less than 30 minutes prior
to initiation of HRG survey equipment and must continue until one hour
after use of the acoustic source ceases or until 30 minutes past
sunset. PSOs would coordinate to ensure 360[deg] visual coverage around
the vessel from the most appropriate observation posts, and must
conduct visual observations using binoculars and the naked eye while
free from distractions and in a consistent, systematic, and diligent
manner. PSOs may be on watch for a maximum of four consecutive hours
followed by a break of at least two hours between watches and may
conduct a maximum of 12 hours of observation per 24-hour period. In
cases where multiple vessels are surveying concurrently, any
observations of marine mammals must be communicated to PSOs on all
survey vessels.
PSOs must be equipped with binoculars and have the ability to
estimate distances to marine mammals located in proximity to the vessel
and/or exclusion zone using range finders. Reticulated binoculars must
also be available to PSOs for use as appropriate based on conditions
and visibility to support the monitoring of marine mammals. Position
data must be recorded using hand-held or vessel GPS units for each
sighting. Observations must take place from the highest available
vantage point on the survey vessel. General 360-degree scanning must
occur during the monitoring periods, and target scanning by the PSO
must occur when alerted of a marine mammal presence.
During good conditions (e.g., daylight hours; Beaufort sea state
(BSS) 3 or less), to the maximum extent practicable, PSOs will conduct
observations when the acoustic source is not operating for comparison
of sighting rates and behavior with and without use of the acoustic
source and between acquisition periods. Any observations of marine
mammals by crew members aboard any vessel associated with the survey
must be relayed to the PSO team.
Data on all PSO observations must be recorded based on standard PSO
collection requirements. This includes dates, times, and locations of
survey operations; dates and times of observations, location and
weather; details of marine mammal sightings (e.g., species, numbers,
behavior); and details of any observed marine mammal take that occurs
(e.g., noted behavioral disturbances).
Reporting Measures
Within 90 days after completion of survey activities, a final
technical report must be provided to NMFS that fully documents the
methods and monitoring protocols, summarizes the data recorded during
monitoring, summarizes the number of marine mammals estimated to have
been taken during survey activities (by species, when known),
summarizes the mitigation actions taken during surveys (including what
type of mitigation and the species and number of animals that prompted
the mitigation action, when known), and provides an interpretation of
the results and effectiveness of all mitigation and
[[Page 66173]]
monitoring. Any recommendations made by NMFS must be addressed in the
final report prior to acceptance by NMFS. PSO datasheets or raw
sightings data must also be provided with the draft and final
monitoring report.
In addition to the final technical report, Skipjack must provide
the reporting described below as necessary during survey activities. If
a North Atlantic right whale is observed at any time during surveys or
during vessel transit, Skipjack must report sighting information to the
NMFS North Atlantic Right Whale Sighting Advisory System. North
Atlantic right whale sightings in any location may also be reported to
the U.S. Coast Guard via channel 16.
In the unanticipated event that Skipjack's survey activities lead
to an injury (Level A harassment) or mortality (e.g., ship-strike, gear
interaction, and/or entanglement) of a marine mammal, Skipjack must
immediately cease the specified activities and report the incident to
the Chief of the Permits and Conservation Division, Office of Protected
Resources and the NMFS New England/Mid-Atlantic Stranding Coordinator.
The report must include the following information:
Time, date, and location (latitude/longitude) of the
incident;
Name and type of vessel involved;
Vessel's speed during and leading up to the incident;
Description of the incident;
Status of all sound source use in the 24 hours preceding
the incident;
Water depth;
Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, and visibility);
Description of all marine mammal observations in the 24
hours preceding the incident;
Species identification or description of the animal(s)
involved;
Fate of the animal(s); and
Photographs or video footage of the animal(s) (if
equipment is available).
Activities would not resume until NMFS is able to review the
circumstances of the event. NMFS would work with Skipjack to minimize
reoccurrence of such an event in the future. Skipjack would not resume
activities until notified by NMFS.
In the event that Skipjack discovers an injured or dead marine
mammal and determines that the cause of the injury or death is unknown
and the death is relatively recent (i.e., in less than a moderate state
of decomposition), Skipjack would immediately report the incident to
the Chief of the Permits and Conservation Division, Office of Protected
Resources and the NMFS New England/Mid-Atlantic Stranding Coordinator.
The report would include the same information identified in the
paragraph above. Activities would be able to continue while NMFS
reviews the circumstances of the incident. NMFS would work with
Skipjack to determine if modifications in the activities are
appropriate.
In the event that Skipjack discovers an injured or dead marine
mammal and determines that the injury or death is not associated with
or related to the activities authorized in the IHA (e.g., previously
wounded animal, carcass with moderate to advanced decomposition, or
scavenger damage), Skipjack would report the incident to the Chief of
the Permits and Conservation Division, Office of Protected Resources,
and the NMFS New England/Mid-Atlantic Regional Stranding Coordinator,
within 24 hours of the discovery. Skipjack would provide photographs or
video footage (if available) or other documentation of the stranded
animal sighting to NMFS. Skipjack may continue its operations in such a
case.
Negligible Impact Analysis and Determination
NMFS has defined negligible impact as an impact resulting from the
specified activity that cannot be reasonably expected to, and is not
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
``taken'' through harassment, NMFS considers other factors, such as the
likely nature of any responses (e.g., intensity, duration), the context
of any responses (e.g., critical reproductive time or location,
migration), as well as effects on habitat, and the likely effectiveness
of the mitigation. We also assess the number, intensity, and context of
estimated takes by evaluating this information relative to population
status. Consistent with the 1989 preamble for NMFS's implementing
regulations (54 FR 40338; September 29, 1989), the impacts from other
past and ongoing anthropogenic activities are incorporated into this
analysis via their impacts on the environmental baseline (e.g., as
reflected in the regulatory status of the species, population size and
growth rate where known, ongoing sources of human-caused mortality, or
ambient noise levels).
To avoid repetition, our analysis applies to all the species listed
in Table 2, given that NMFS expects the anticipated effects of the
planned survey to be similar in nature.
NMFS does not anticipate that serious injury or mortality would
occur as a result of Skipjack's survey, even in the absence of
mitigation. Thus the authorization does not authorize any serious
injury or mortality. As discussed in the Potential Effects section,
non-auditory physical effects and vessel strike are not expected to
occur. Additionally and as discussed previously, given the nature of
activity and sounds sources used and especially in consideration of the
required mitigation, Level A harassment is neither anticipated nor
authorized. We expect that all potential takes would be in the form of
short-term Level B behavioral harassment in the form of temporary
avoidance of the area, reactions that are considered to be of low
severity and with no lasting biological consequences (e.g., Southall et
al., 2007).
Effects on individuals that are taken by Level B harassment, on the
basis of reports in the literature as well as monitoring from other
similar activities, will likely be limited to reactions such as
increased swimming speeds, increased surfacing time, or decreased
foraging (if such activity were occurring) (e.g., Thorson and Reyff,
2006; HDR, Inc., 2012; Lerma, 2014). Most likely, individuals will
simply move away from the sound source and temporarily avoid the area
where the survey is occurring. We expect that any avoidance of the
survey area by marine mammals would be temporary in nature and that any
marine mammals that avoid the survey area during the survey activities
would not be permanently displaced. Even repeated Level B harassment of
some small subset of an overall stock is unlikely to result in any
significant realized decrease in viability for the affected
individuals, and thus would not result in any adverse impact to the
stock as a whole.
In addition to being temporary and short in overall duration, the
acoustic footprint of the survey is small relative to the overall
distribution of the animals in the area and their use of the area.
Feeding behavior is not likely to be significantly impacted. Prey
species are mobile and are broadly distributed throughout the project
area; therefore, marine mammals that may be temporarily displaced
during survey activities are expected to be able to resume foraging
once they have moved
[[Page 66174]]
away from areas with disturbing levels of underwater noise. Because of
the temporary nature of the disturbance and the availability of similar
habitat and resources in the surrounding area, the impacts to marine
mammals and the food sources that they utilize are not expected to
cause significant or long-term consequences for individual marine
mammals or their populations.
There are no rookeries, mating or calving grounds known to be
biologically important to marine mammals within the survey area and
there are no feeding areas known to be biologically important to marine
mammals within the survey area. There is no designated critical habitat
for any ESA-listed marine mammals in the survey area. The survey area
overlaps a portion of a biologically important migratory area for North
Atlantic right whales (effective March-April and November-December)
that extends from Massachusetts to Florida (LaBrecque, et al., 2015).
Off the coasts of Delaware and Maryland, this biologically important
migratory area extends from the coast to beyond the shelf break. Due to
the fact that that the survey is temporary and the spatial extent of
sound produced by the survey would be very small relative to the
spatial extent of the available migratory habitat in the area, right
whale migration is not expected to be impacted by the survey.
Potential impacts to marine mammal habitat were discussed
previously in this document (see Potential Effects of the Specified
Activity on Marine Mammals and their Habitat). Marine mammal habitat
may be impacted by elevated sound levels, but these impacts would be
temporary. Repeated exposures of individuals to relatively low levels
of sound outside of preferred habitat areas are unlikely to
significantly disrupt critical behaviors. We expect that animals
disturbed by sound associated with the planned survey would simply
avoid the area during the survey in favor of other, similar habitats.
As described above, North Atlantic right, humpback, and minke
whales, and gray and harbor seals are experiencing ongoing UMEs. For
North Atlantic right whales, as described above, no injury as a result
of the proposed survey is expected or authorized, and Level B
harassment takes of right whales are expected to be in the form of
avoidance of the immediate area of the proposed survey. In addition,
the number of takes authorized above the Level B harassment threshold
are minimal (i.e., 3). As no injury or mortality is expected or
authorized, and Level B harassment of North Atlantic right whales will
be reduced to the level of least practicable adverse impact through use
of mitigation measures, the authorized takes of right whales would not
exacerbate or compound the ongoing UME in any way.
Similarly, no injury or mortality is expected or authorized for any
of the other species with UMEs, Level B harassment will be reduced to
the level of least practicable adverse impact through use of mitigation
measures, and the authorized takes would not exacerbate or compound the
ongoing UMEs. For minke whales, although the ongoing UME is under
investigation (as occurs for all UMEs), this event does not provide
cause for concern regarding population level impacts, as the likely
population abundance is greater than 20,000 whales. Even though the PBR
value is based on an abundance for U.S. waters that is negatively
biased and a small fraction of the true population abundance, annual M/
SI does not exceed the calculated PBR value for minke whales. With
regard to humpback whales, the UME does not yet provide cause for
concern regarding population-level impacts. Despite the UME, the
relevant population of humpback whales (the West Indies breeding
population, or distinct population segment (DPS)) remains healthy. The
West Indies DPS, which consists of the whales whose breeding range
includes the Atlantic margin of the Antilles from Cuba to northern
Venezuela, and whose feeding range primarily includes the Gulf of
Maine, eastern Canada, and western Greenland, was delisted. The status
review identified harmful algal blooms, vessel collisions, and fishing
gear entanglements as relevant threats for this DPS, but noted that all
other threats are considered likely to have no or minor impact on
population size or the growth rate of this DPS (Bettridge et al.,
2015). As described in Bettridge et al. (2015), the West Indies DPS has
a substantial population size (i.e., approximately 10,000; Stevick et
al., 2003; Smith et al., 1999; Bettridge et al., 2015), and appears to
be experiencing consistent growth. With regard to gray and harbor
seals, although the ongoing UME is under investigation, the UME does
not yet provide cause for concern regarding population-level impacts to
any of these stocks. For harbor seals, the population abundance is over
75,000 and annual M/SI (345) is well below PBR (2,006) (Hayes et al.,
2018). For gray seals, the population abundance in the United States is
over 27,000, with an estimated abundance including seals in Canada of
approximately 505,000, and abundance is likely increasing in the U.S.
Atlantic EEZ as well as in Canada (Hayes et al., 2018).
The mitigation measures are expected to reduce the number and/or
severity of takes by giving animals the opportunity to move away from
the sound source before HRG survey equipment reaches full energy and by
establishing zones that will prevent animals from being exposed to
higher sound levels that may otherwise result in injury or more severe
behavioral responses. No Level A harassment, which involves the
potential for injury, has been authorized. Additional vessel strike
avoidance requirements will further mitigate potential impacts to
marine mammals during vessel transit to and within the survey area.
NMFS concludes that exposures to marine mammal species and stocks
due to Skipjack's survey would result in only short-term (temporary and
short in duration) effects to individuals exposed. Marine mammals may
temporarily avoid the immediate area, but are not expected to
permanently abandon the area. Major shifts in habitat use,
distribution, or foraging success are not expected. NMFS does not
anticipate the authorized takes 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 mortality, serious injury, or Level A harassment is
anticipated or authorized;
The anticipated impacts of the activity on marine mammals
would primarily be in the form of temporary behavioral changes due to
avoidance of the area around the survey vessel;
The availability of alternate areas of similar habitat
value (for foraging, etc.) for marine mammals that may temporarily
vacate the survey area during the survey to avoid exposure to sounds
from the activity;
The survey area does not contain known areas of
significance for mating or calving;
Effects on species that serve as prey species for marine
mammals from the survey would be minor and temporary and would not be
expected to reduce the availability of prey or to affect marine mammal
feeding;
The mitigation measures, including visual and acoustic
monitoring, exclusion zones, and shutdown measures, are expected to
minimize potential impacts to marine mammals.
[[Page 66175]]
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
proposed activity will have a negligible impact on all affected marine
mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under Sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. Additionally, other qualitative
factors may be considered in the analysis, such as the temporal or
spatial scale of the activities.
The numbers of marine mammals that we authorize to be taken, for
all species and stocks, would be considered small relative to the
relevant stocks or populations (less than 28 percent for two of
seventeen species and stocks, and less than 1 percent for all remaining
species and stocks). See Table 6. 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.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
determined that the total taking of affected species or stocks would
not have an unmitigable adverse impact on the availability of such
species or stocks for taking for subsistence purposes.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must evaluate our proposed action (i.e., the promulgation of
regulations and subsequent issuance of incidental take authorization)
and alternatives with respect to potential impacts on the human
environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 of the Companion Manual for NAO 216-6A,
which do not individually or cumulatively have the potential for
significant impacts on the quality of the human environment and for
which we have not identified any extraordinary circumstances that would
preclude this categorical exclusion. Accordingly, NMFS has determined
that the proposed action qualifies to be categorically excluded from
further NEPA review.
Endangered Species Act
Section 7(a)(2) of the Endangered Species Act of 1973 (16 U.S.C.
1531 et seq.) requires that each Federal agency insure that any action
it authorizes, funds, or carries out is not likely to jeopardize the
continued existence of any endangered or threatened species or result
in the destruction or adverse modification of designated critical
habitat. To ensure ESA compliance for the issuance of IHAs, NMFS
consults internally, in this case with the NMFS Greater Atlantic
Regional Fisheries Office (GARFO), whenever we propose to authorize
take for endangered or threatened species.
The NMFS Office of Protected Resources Permits and Conservation
Division is authorizing the incidental take of four species of marine
mammals which are listed under the ESA: The North Atlantic right, fin,
sei and sperm whale. We requested initiation of consultation under
Section 7 of the ESA with NMFS GARFO on September 30, 2019, for the
issuance of this IHA. In November, 2019, NMFS GARFO determined our
issuance of the IHA to Skipjack was not likely to adversely affect the
North Atlantic right, fin, sei and sperm whale or the critical habitat
of any ESA-listed species or result in the take of any marine mammals
in violation of the ESA.
Authorization
NMFS has issued an IHA to Skipjack for conducting marine site
characterization surveys offshore of Delaware and Maryland, from the
date of issuance for a period of one year, provided the previously
mentioned mitigation, monitoring, and reporting requirements are
incorporated.
Dated: November 26, 2019.
Angela Somma,
Chief, Endangered Species Conservation Division, Office of Protected
Resources, National Marine Fisheries Service.
[FR Doc. 2019-26091 Filed 12-2-19; 8:45 am]
BILLING CODE 3510-22-P