Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Marine Site Characterization Surveys off of Delaware, 14417-14443 [2018-06856]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 83, Number 65 (Wednesday, April 4, 2018)]
[Notices]
[Pages 14417-14443]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-06856]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XF991


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Marine Site Characterization 
Surveys off of Delaware

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; proposed incidental harassment authorization; request 
for comments.

-----------------------------------------------------------------------

SUMMARY: NMFS has received a request from Garden State Offshore Energy, 
LLC (GSOE), for authorization to take marine mammals incidental to 
marine site characterization surveys off the coast of Delaware as part 
of the Skipjack Wind Project in the area of the Commercial Lease of 
Submerged Lands for Renewable Energy Development on the Outer 
Continental Shelf (OCS-A 0482) and along potential submarine cable 
routes to a landfall location in Maryland or Delaware. Pursuant to the 
Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its 
proposal to issue an incidental harassment authorization (IHA) to 
incidentally take marine mammals during the specified activities. NMFS 
will consider public comments prior to making any final decision on the 
issuance of the requested MMPA authorizations and agency responses will 
be summarized in the final notice of our decision.

DATES: Comments and information must be received no later than May 4, 
2018.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. Physical comments should be sent to 
1315 East-West Highway, Silver Spring, MD 20910, and electronic 
comments should be sent to [email protected].
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted online at

[[Page 14418]]

www.nmfs.noaa.gov/pr/permits/incidental/energy_other.htm without 
change. All personal identifying information (e.g., name, address) 
voluntarily submitted by the commenter may be publicly accessible. Do 
not submit confidential business information or otherwise sensitive or 
protected information.

FOR FURTHER INFORMATION CONTACT: Jordan Carduner, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the applications 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained by visiting the internet at: 
www.nmfs.noaa.gov/pr/permits/incidental/energy_other.htm. In case of 
problems accessing these documents, please call the contact listed 
above.

SUPPLEMENTARY INFORMATION: 

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C.1361 et seq.) 
direct the Secretary of Commerce (as delegated to NMFS) to allow, upon 
request, the incidental, but not intentional, taking of small numbers 
of marine mammals by U.S. citizens who engage in a specified activity 
(other than commercial fishing) within a specified geographical region 
if certain findings are made and either regulations are issued or, if 
the taking is limited to harassment, a notice of a proposed 
authorization is provided to the public for review.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth.
    NMFS has defined ``negligible impact'' in 50 CFR 216.103 as an 
impact resulting from the specified activity that cannot be reasonably 
expected to, and is not reasonably likely to, adversely affect the 
species or stock through effects on annual rates of recruitment or 
survival.
    The MMPA states that the term ``take'' means to harass, hunt, 
capture, or kill, or attempt to harass, hunt, capture, or kill any 
marine mammal.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild (Level A harassment); or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering (Level B harassment).

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) with respect to potential impacts 
on the human environment.
    Accordingly, NMFS is preparing an Environmental Assessment (EA) to 
consider the environmental impacts associated with the issuance of the 
proposed IHA. We will review all comments submitted in response to this 
notice prior to concluding our NEPA process or making a final decision 
on the IHA request.

Summary of Request

    On November 22, 2017, NMFS received a request from GSOE for an IHA 
to take marine mammals incidental to marine site characterization 
surveys off the coast of Delaware in the area of the Commercial Lease 
of Submerged Lands for Renewable Energy Development on the Outer 
Continental Shelf (OCS-A 0482) (Lease Area) and along potential 
submarine cable routes to a landfall location in Maryland or Delaware. 
GSOE has designated Skipjack Offshore Energy, LLC (Skipjack), a wholly-
owned indirect subsidiary of Deepwater Wind Holdings, LLC (Deepwater 
Wind), and an affiliate of GSOE, to perform the activities described in 
the IHA application. A revised application was received on March 19, 
2018. NMFS deemed that request to be adequate and complete. GSOE's 
request is for take of 14 marine mammal species by Level B harassment. 
Neither GSOE nor NMFS expects serious injury or mortality to result 
from this activity, and the activity is expected to last no more than 
one year Therefore, an IHA is appropriate.

Description of the Proposed Activity

Overview

    GSOE proposes to conduct marine site characterization surveys, 
including high-resolution geophysical (HRG) and geotechnical surveys, 
in the Lease Area and along potential submarine cable routes to 
landfall locations in either the state of Maryland or Delaware. Surveys 
would occur from approximately May 2018 through December 2018.
    The purpose of the marine site characterization 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 the 
proposed Skipjack wind farm. Underwater sound resulting from GSOE's 
proposed site characterization surveys have the potential to result in 
incidental take of marine mammals in the form of behavioral harassment.

Dates and Duration

    The site characterization surveys would occur between May 15, 2018, 
and December 31, 2018. During this time period, geophysical surveys 
would be conducted for up to 183 days and geotechnical surveys would be 
conducted for up to 72 days. This schedule is based on 24-hour 
operations and includes potential down time due to inclement weather. 
Surveys will last for approximately seven months and are anticipated to 
commence upon issuance of the requested IHA, if appropriate.

Specific Geographic Region

    GSOE's survey activities would occur in the Northwest Atlantic 
Ocean within Federal waters. Surveys would occur in the Lease Area and 
along potential submarine cable routes to landfall locations in the 
state of Maryland and Delaware (see Figure 1 in the IHA application). 
The Lease Area is approximately 390 square kilometers (km\2\) (96,430 
acres). The Lease Area is approximately 11 miles due east from Rehoboth 
Beach, Delaware, at its closest point to shore.

Detailed Description of the Specified Activities

    GSOE's proposed marine site characterization surveys include HRG 
and geotechnical survey activities. Surveys would occur within the 
Bureau of Ocean Energy Management (BOEM) Delaware Wind Energy Area (DE 
WEA) which is east of Delaware (see Figure 1 in the IHA application). 
Water depths in the Lease Area range from 16 to 28 meters (m) (52 to 92 
feet (ft)). For the purpose of this IHA the Lease Area and submarine 
cable corridor are collectively termed the Project Area.
    Geophysical and shallow geotechnical survey activities are 
anticipated to be supported by a vessel approximately 30-60 m (100-200 
ft) long which will maintain a speed of between two to five knots (kn) 
while transiting survey lines. Deep geotechnical survey activities and 
possible shallow geotechnical activities are anticipated to be 
conducted from an 80 to 100 m (250 to 300 ft) dynamically

[[Page 14419]]

positioned (DP) vessel with support of a tug boat. Survey activities 
will be executed in compliance with the July 2015 BOEM Guidelines for 
Providing Geophysical, Geotechnical, and Geohazard Information Pursuant 
to 30 CFR part 585. The proposed HRG and geotechnical survey activities 
are described below.

Geotechnical Survey Activities

    GSOE's proposed geotechnical survey activities would include the 
following:
     Vibracores to characterize the geological and geotechnical 
characteristics of the seabed, up to approximately 5 m deep. 
Vibracoring entails use of a hydraulic or electric driven pulsating 
head to drive a hollow tube into the seafloor and recover a stratified 
representation of the sediment.
     Core Penetration Testing (CPT) to determine stratigraphy 
and in-situ conditions of the sediments. Target penetration is 60 to 75 
m.
     Deep Boring Cores would be drilled to determine the 
vertical and lateral variation in seabed conditions and provide 
geotechnical data to depths at least 10 m deeper than design 
penetration of the foundations (60 to 75 m target penetration).
    GSOE's proposed geotechnical survey activities would last up to 72 
days. Shallow geotechnical surveys, consisting of CPTs and vibracores, 
are planned for within the Lease Area and approximately every 1-2 
kilometers (km) along the export cable routes. Foundation-depth 
geotechnical borings are also planned at each proposed foundation 
location within the Lease Area. While the quantity and locations of 
wind turbine generators to be installed, as well as cable route, has 
yet to be determined, an estimate of 66 vibracores, 21 CPTs, and 22 
deep borings are planned within the Lease Area and along the export 
cable routes. The geotechnical sampling will be conducted from a DP 
vessel, approximately 80 m in length.
    In considering whether marine mammal harassment is an expected 
outcome of exposure to a particular activity or sound source, NMFS 
considers the nature of the exposure itself (e.g., the magnitude, 
frequency, or duration of exposure), characteristics of the marine 
mammals potentially exposed, and the conditions specific to the 
geographic area where the activity is expected to occur (e.g., whether 
the activity is planned in a foraging area, breeding area, nursery or 
pupping area, or other biologically important area for the species). We 
then consider the expected response of the exposed animal and whether 
the nature and duration or intensity of that response is expected to 
cause disruption of behavioral patterns (e.g., migration, breathing, 
nursing, breeding, feeding, or sheltering) or injury.
    Geotechnical survey activities would be conducted from a drill ship 
equipped with DP thrusters. DP thrusters would be used to position the 
sampling vessel on station and maintain position at each sampling 
location during the sampling activity. Sound produced through use of DP 
thrusters is similar to that produced by transiting vessels and DP 
thrusters are typically operated either in a similarly predictable 
manner or used for short durations around stationary activities. NMFS 
does not believe acoustic impacts from DP thrusters are likely to 
result in take of marine mammals in the absence of activity- or 
location-specific circumstances that may otherwise represent specific 
concerns for marine mammals (i.e., activities proposed in area known to 
be of particular importance for a particular species), or associated 
activities that may increase the potential to result in take when in 
concert with DP thrusters. In this case, we are not aware of any such 
circumstances. Monitoring of past projects that entailed use of DP 
thrusters has shown a lack of observed marine mammal responses as a 
result of exposure to sound from DP thrusters. Therefore, NMFS believes 
the likelihood of DP thrusters used during the proposed geotechnical 
surveys resulting in harassment of marine mammals to be so low as to be 
discountable. As DP thrusters are not expected to result in take of 
marine mammals, these activities are not analyzed further in this 
document.
    Vibracoring entails driving a hydraulic or electric pulsating head 
through a hollow tube into the seafloor to recover a stratified 
representation of the sediment. The vibracoring process is short in 
duration and is performed from a dynamic positioning vessel. The vessel 
would use DP thrusters to maintain the vessel's position while the 
vibracore sample is taken, as described above. The vibracoring process 
would always be performed in concert with DP thrusters, and DP 
thrusters would begin operating prior to the activation of the 
vibracore to maintain the vessel's position; thus, we expect that any 
marine mammals in the project area would detect the presence and noise 
associated with the vessel and the DP thrusters prior to commencement 
of vibracoring. Any reaction by marine mammals would be expected to be 
similar to reactions to the concurrent DP thrusters, which are expected 
to be minor and short term. In this case, vibracoring is not planned in 
any areas of particular biological significance for any marine mammals. 
Thus while a marine mammal may perceive noise from vibracoring and may 
respond briefly, we believe the potential for this response to rise to 
the level of take to be so low as to be discountable, based on the 
short duration of the activity and the fact that marine mammals would 
be expected to react to the vessel and DP thrusters before vibracoring 
commences, potentially through brief avoidance. In addition, the fact 
that the geographic area is not biologically important for any marine 
mammal species means that such reactions are not likely to carry any 
meaningful significance for the animals.
    Field studies conducted off the coast of Virginia to determine the 
underwater noise produced by CPTs and borehole drilling found that 
these activities did not result in underwater noise levels that 
exceeded current thresholds for Level B harassment of marine mammals 
(Kalapinski, 2015). Given the small size and energy footprint of CPTs 
borehole drilling, NMFS believes the likelihood that noise from these 
activities would exceed the Level B harassment threshold at any 
appreciable distance is so low as to be discountable. Therefore, 
geotechnical survey activities, including CPTs, borehole drilling and 
vibracores, are not expected to result in harassment of marine mammals 
and are not analyzed further in this document.

Geophysical Survey Activities

    GSOE has proposed that HRG survey operations would be conducted 
continuously 24 hours per day. Based on 24-hour operations, the 
estimated duration of the geophysical survey activities would be 
approximately 183 days (including estimated weather down time). The 
geophysical survey activities proposed by GSOE would include the 
following:
     Multibeam Depth Sounder to determine water depths and 
general bottom topography. The multibeam echosounder sonar system 
projects sonar pulses in several angled beams from a transducer mounted 
to a ship's hull. The beams radiate out from the transducer in a fan-
shaped pattern orthogonally to the ship's direction.
     Shallow Penetration Sub-Bottom Profiler (Chirp) to map the 
near surface stratigraphy (top 0 to 5 m of sediment below seabed). A 
Chirp system emits sonar pulses which increase in frequency (3.5 to 200 
kHz) over time. The pulse length frequency range can be adjusted to 
meet project variables.
     Medium Penetration Sub-Bottom Profiler (Boomer) to map 
deeper subsurface stratigraphy as needed. This

[[Page 14420]]

system is commonly mounted on a sled and towed behind a boat.
     Medium Penetration Sub-Bottom Profiler (Sparker and/or 
bubble gun) to map deeper subsurface stratigraphy as needed. Sparkers 
create acoustic pulses omni-directionally from the source that can 
penetrate several hundred meters into the seafloor. Hydrophone arrays 
towed nearby receive the return signals.
     Sidescan Sonar used to image the seafloor for seabed 
sediment classification purposes and to identify natural and man-made 
acoustic targets on the seafloor. The sonar device emits conical or 
fan-shaped pulses down toward the seafloor in multiple beams at a wide 
angle, perpendicular to the path of the sensor through the water. The 
acoustic return of the pulses is recorded in a series of cross-track 
slices, which can be joined to form an image of the sea bottom within 
the swath of the beam.
     Marine Magnetometer to detect ferrous metal objects on the 
seafloor which may cause a hazard including anchors, chains, cables, 
pipelines, ballast stones and other scattered shipwreck debris, 
munitions of all sizes, unexploded ordinances, aircraft, engines and 
any other object with magnetic expression.
    Table 1 identifies the representative survey equipment that may be 
used in support of planned geophysical survey activities. The make and 
model of the listed geophysical equipment will vary depending on 
availability and the final equipment choices will vary depending upon 
the final survey design, vessel availability, and survey contractor 
selection. Any survey equipment selected would have characteristics 
similar to the systems described below, if different.

                                        Table 1--Summary of Geophysical Survey Equipment Proposed for Use by GSOE
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 Operational depth
        Equipment type           Operating frequencies   Source level (SLrms       (meters below        Beam width (degrees)         Pulse duration
                                         (kHz)           dB re 1 [mu]PA @1 m)         surface)                                       (milliseconds)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Multibeam Depth Sounding
--------------------------------------------------------------------------------------------------------------------------------------------------------
Reson SeaBat 7125 \1\.........  200 and 400...........  220..................  4....................  128.....................  0.03 to 0.3.
Reson SeaBat 7101 \2\.........  100...................  162..................  2 to 5...............  140.....................  0.8 to 3.04.
R2SONIC Sonic 2020 \1\........  170 to 450............  162..................  2 to 5...............  160.....................  0.11.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                              Shallow Sub-bottom Profiling
--------------------------------------------------------------------------------------------------------------------------------------------------------
Teledyne Benthos Chirp III \3\  2 to 7................  197..................  4....................  45......................  0.2.
EdgeTech SB3200 XS............  2 to 16...............  176..................  2 to 5...............  170.....................  3.4.
SB216\4\......................
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Medium Penetration Sub-bottom Profiling
--------------------------------------------------------------------------------------------------------------------------------------------------------
Applied Acoustics.............  0.1 to 10.............  175..................  1 to 2...............  60......................  58.
Fugro boomer \1\..............
Applied Acoustics S-Boom        0.25 to 8.............  203..................  2....................  25 to 35................  0.6.
 system--CSP-D 2400HV (600
 joule/pulse) \5\.
GeoResources 800 Joule Sparker  0.75 to 2.75..........  203..................  4....................  360 (omni-directional)..  0.1 to 0.2.
 \6\.
Falmouth Scientific HMS 620     0.02 to 1.7...........  196..................  1.5..................  360 (omni-directional)..  1.6.
 bubble gun \7\.
Applied Acoustics.............  0.03 to 5.............  213..................  1 to 2...............  170.....................  2.1.
Dura-Spark 240 \5\............
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                                                                     Side Scan Sonar
--------------------------------------------------------------------------------------------------------------------------------------------------------
Klein Marine Systems model      445 and 900...........  242..................  20...................  40......................  0.025.
 3900 \1\.
EdgeTech model 4125 \1\.......  105 and 410...........  225..................  10...................  158.....................  10 to 20.
EdgeTech model 4200 \1\.......  300 and 600...........  215 to 220...........  1....................  0.5 and 0.26............  5 to 12.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Source level obtained from equipment specifications as described in 82 FR 22250: ``Takes of Marine Mammals Incidental to Specified Activities;
  Taking Marine Mammals Incidental to Site Characterization Surveys off the Coast of New York.''
\2\ Source level based on published manufacturer specifications and/or systems manual.
\3\ Source level based on published manufacturer specifications and/or systems manual--assumed configured as TTV-171 with AT-471 transducer per system
  manual.
\4\ Source level obtained from Crocker and Fratantonio (2016). Assumed to be 3200 XS with SB216. Used as proxy: 3200 XS with SB424 in 4-24 kHz mode
  Since the 3200 XS system manual lists same power output between SB216 and SB 424.
\5\ Source level obtained from Crocker and Fratantonio (2016).
\6\ Source level obtained from Crocker and Fratantonio (2016)--ELC820 used as proxy.
\7\ Source level obtained from Crocker and Fratantonio (2016)--Used single plate 1 due to discrepancies noted in Crocker and Fratantonio (2016)
  regarding plate 2.

    The deployment of HRG survey equipment, including the equipment 
planned for use during GSOE's planned activity, produces sound in the 
marine environment that has the potential to result in harassment of 
marine mammals. However, sound propagation is dependent on several 
factors including operating mode, frequency and beam direction of the 
HRG equipment; thus, potential impacts to marine mammals from HRG 
equipment are driven by the specification of individual HRG sources. 
The specifications of the potential equipment planned for use during 
HRG survey activities (Table 1) were analyzed to determine which types 
of equipment would have the potential to result in harassment of marine 
mammals. HRG equipment that would

[[Page 14421]]

be operated either at frequency ranges that fall outside the functional 
hearing ranges of marine mammals (e.g., above 200 kHz) or that that 
operate within marine mammal functional hearing ranges but have low 
sound source levels (e.g., a single pulse at less than 200 dB re re 1 
[mu]Pa) were assumed to not have the potential to result in marine 
mammal harassment and were therefore eliminated from further analysis. 
Of the potential HRG survey equipment planned for use, the following 
equipment was determined to have the potential to result in harassment 
of marine mammals:
     Teledyne Benthos Chirp III Sub-bottom Profiler;
     EdgeTech Sub-bottom Profilers (Chirp);
     Applied Acoustics Fugro Sub-bottom Profiler (Boomer);
     Applied Acoustics S-Boom Sub-bottom Profiling System 
consisting of a CSP-D 2400HV power supply and 3-plate catamaran;
     GeoResources 800 Joule Sparker;
     Falmouth Scientific HMS 620 Bubble Gun; and
     Applied Acoustics Dura-Spark 240 System;
    As the HRG survey equipment listed above was determined to have the 
potential to result in harassment of marine mammals, the equipment 
listed above was carried forward in the analysis of potential impacts 
to marine mammals; all other HRG equipment planned for use by GSOE is 
not expected to result in harassment of marine mammals and is therefore 
not analyzed further in this document.
    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see ``Proposed 
Mitigation'' and ``Proposed Monitoring and Reporting'').

Description of Marine Mammals in the Area of Specified Activity

    Sections 3 and 4 of GSOE's 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 (SAR; www.nmfs.noaa.gov/pr/sars/) and more general information about these species (e.g., 
physical and behavioral descriptions) may be found on NMFS' website 
(www.nmfs.noaa.gov/pr/species/mammals/). All species that could 
potentially occur in the proposed survey areas are included in Table 5 
of the IHA application. However, the temporal and/or spatial occurrence 
of several species listed in Table 5 of the IHA application is such 
that take of these species is not expected to occur, and they are not 
discussed further beyond the explanation provided here. Take of these 
species is not anticipated either because they have very low densities 
in the project area, are known to occur further offshore than the 
project area, or are considered very unlikely to occur in the project 
area during the proposed survey due to the species' seasonal occurrence 
in the area.
    Table 2 lists all species with expected potential for occurrence in 
the survey area and with the potential to be taken as a result of the 
proposed survey and 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 (2017). 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. 2017 draft SARs (e.g., Hayes et al., 2018). All values 
presented in Table 2 are the most recent available at the time of 
publication and are available in the 2017 draft Atlantic SARs (Hayes et 
al., 2018).

                                                Table 2--Marine Mammals Known to Occur in the Survey Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                   NMFS stock
                                                          NMFS MMPA and ESA        abundance           Predicted                        Occurrence and
           Common name                     Stock          status; strategic      (CV,Nmin, most     abundance (CV)       PBR \4\      seasonality in the
                                                              (Y/N) \1\         recent abundance          \3\                            survey area
                                                                                  survey) \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Toothed whales (Odontoceti)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale (Physeter              North Atlantic......  E; Y...............  2,288 (0.28; 1,815;      5,353 (0.12)             3.6  Rare.
 macrocephalus).                                                               n/a).
Long-finned pilot whale            W. North Atlantic...  --; Y..............  5,636 (0.63; 3,464;        \6\ 18,977              35  Rare.
 (Globicephala melas).                                                         n/a).                         (0.11)
Atlantic white-sided dolphin       W. North Atlantic...  --; N..............  48,819 (0.61;           37,180 (0.07)             304  Rare.
 (Lagenorhynchus acutus).                                                      30,403; n/a).
Atlantic spotted dolphin           W. North Atlantic...  --; N..............  44,715 (0.43;           55,436 (0.32)             316  Rare.
 (Stenella frontalis).                                                         31,610; n/a).
Bottlenose dolphin (Tursiops       W. North Atlantic,    --; N..............  77,532 (0.40;              \5\ 97,476             561  Common year round.
 truncatus).                        Offshore.                                  56,053; 2011).                (0.06)
                                   W. North Atlantic,    --; N..............  6,639 (0.41; 4,759;  ................              48  Common in summer;
                                    Northern Migratory                         2015).                                                 rare in winter.
                                    Coastal.

[[Page 14422]]

 
Short-beaked common dolphin        W. North Atlantic...  --; N..............  70,184 (0.28;           86,098 (0.12)             557  Common year round.
 (Delphinus delphis).                                                          55,690; 2011).
Harbor porpoise (Phocoena          Gulf of Maine/Bay of  --; N..............  79,833 (0.32;         * 45,089 (0.12)             706  Common year round.
 phocoena).                         Fundy.                                     61,415; 2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Baleen whales (Mysticeti)
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Atlantic right whale         W. North Atlantic...  E; Y...............  458 (0; 455; n/a)..      * 535 (0.45)             1.4  Year round in
 (Eubalaena glacialis).                                                                                                               continental shelf
                                                                                                                                      and slope waters,
                                                                                                                                      occur seasonally
                                                                                                                                      to forage.
Humpback whale \6\ (Megaptera      Gulf of Maine.......  --; N..............  335 (0.42; 239; n/     * 1,637 (0.07)             3.7  Common year round.
 novaeangliae).                                                                a).
Fin whale (Balaenoptera physalus)  W. North Atlantic...  E; Y...............  1,618 (0.33; 1,234;      4,633 (0.08)             2.5  Year round in
                                                                               n/a).                                                  continental shelf
                                                                                                                                      and slope waters,
                                                                                                                                      occur seasonally
                                                                                                                                      to forage.
Sei whale (Balaenoptera borealis)  Nova Scotia.........  E; Y...............  357 (0.52; 236; n/          717 (0.3)             0.5  Year round in
                                                                               a).                                                    continental shelf
                                                                                                                                      and slope waters,
                                                                                                                                      occur seasonally
                                                                                                                                      to forage.
Minke whale (Balaenoptera          Canadian East Coast.  --; N..............  2,591 (0.81; 1,425;    * 2,112 (0.05)             162  Year round in
 acutorostrata).                                                               n/a).                                                  continental shelf
                                                                                                                                      and slope waters,
                                                                                                                                      occur seasonally
                                                                                                                                      to forage.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Earless seals (Phocidae)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray seal \7\ (Halichoerus         W. North Atlantic...  --; N..............  27,131 (0.10;        ................           1,554  Rare.
 grypus).                                                                      25,908; n/a).
Harbor seal (Phoca vitulina).....  W. North Atlantic...  --; N..............  75,834 (0.15;        ................           2,006  Common year round.
                                                                               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\ NMFS marine mammal stock assessment reports online at: www.nmfs.noaa.gov/pr/sars. CV is coefficient of variation; Nmin is the minimum estimate of
  stock abundance. 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 2017 draft Atlantic SARs (Hayes et al., 2018).
\3\ This information represents species- or guild-specific abundance predicted by recent habitat-based cetacean density models (Roberts et al., 2016).
  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).
\5\ Abundance estimates are in some cases reported for a guild or group of species when those species are difficult to differentiate at sea. Similarly,
  the habitat-based cetacean density models produced by Roberts et al. (2016) are based in part on available observational data which, in some cases, is
  limited to genus or guild in terms of taxonomic definition. Roberts et al. (2016) produced density models to genus level for Globicephala spp. and
  produced a density model for bottlenose dolphins that does not differentiate between offshore and coastal stocks.
\6\ NMFS stock abundance estimate applies to Gulf of Maine feeding population. Actual humpback whale population in survey area is likely to be larger
  and to include humpback whales from additional feeding populations in unknown numbers.
\7\ NMFS stock abundance estimate applies to U.S. population only, actual abundance is believed to be much larger.

    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: North Atlantic right whale, fin whale, sei whale and 
sperm whale.
    Below is a description of the species that are both common in the 
survey area east of Delaware and that have the

[[Page 14423]]

highest likelihood of occurring, at least seasonally, in the survey 
area and thus are expected to have the potential to be taken by the 
proposed activities. Though other marine mammal species are known to 
occur in the Northwest Atlantic Ocean, the temporal and/or spatial 
occurrence of several of these species is such that take of these 
species is not expected to occur, and they are therefore not discussed 
further beyond the explanation provided here. Take of these species is 
not anticipated either because they have very low densities in the 
project area (e.g., blue whale, Clymene dolphin, pantropical spotted 
dolphin, striped dolphin, spinner dolphin, killer whale, false killer 
whale, pygmy killer whale, short-finned pilot whale), or, are known to 
occur further offshore than the project area (e.g., beaked whales, 
rough toothed dolphin, Kogia spp.).
    For the majority of species potentially present in the specific 
geographic region, NMFS has designated only a single generic stock 
(e.g., ``western North Atlantic'') for management purposes. This 
includes the ``Canadian east coast'' stock of minke whales, which 
includes all minke whales found in U.S. waters. For humpback and sei 
whales, NMFS defines stocks on the basis of feeding locations, i.e., 
Gulf of Maine and Nova Scotia, respectively. However, our reference to 
humpback whales and sei whales in this document refers to any 
individuals of the species that are found in the specific geographic 
region.

North Atlantic Right Whale

    The North Atlantic right whale ranges from the calving grounds in 
the southeastern United States to feeding grounds in New England waters 
and into Canadian waters (Waring et al., 2016). Surveys have 
demonstrated the existence of seven areas where North Atlantic right 
whales congregate seasonally, including Georges Bank, Cape Cod, and 
Massachusetts Bay (Waring et al., 2016). In the late fall months (e.g., 
October), right whales generally depart from the feeding grounds in the 
North Atlantic and move south to their breeding grounds. Movements 
within and between habitats are extensive, and the area off the mid-
Atlantic states is an important migratory corridor (Waring et al., 
2016). In 2000, one whale was photographed in Florida waters on January 
12, then again 11 days later in Cape Cod Bay, less than a month later 
off Georgia, and back in Cape Cod Bay five weeks later, effectively 
making the round-trip migration to the Southeast and back at least 
twice during the winter season (Brown and Marx 2000). During the 
proposed survey right whales may be migrating through the proposed 
survey area and the surrounding waters.
    The western North Atlantic population demonstrated overall growth 
of 2.8 percent per year between 1990 to 2010, despite a decline in 1993 
and no growth between 1997 and 2000 (Pace et al. 2017). However, since 
2010 the population has been in decline, with a 99.99 percent 
probability of a decline of just under 1 percent per year (Pace et al. 
2017). Between 1990 and 2015, calving rates varied substantially, with 
low calving rates coinciding with all three periods of decline or no 
growth (Pace et al. 2017). On average, North Atlantic right whale 
calving rates are estimated to be roughly half that of southern right 
whales (Eubalaena australis) (Pace et al. 2017), which are increasing 
in abundance (NMFS 2015).
    The proposed survey area is part of the Eastern Atlantic 
Biologically Important Area (BIA) for North Atlantic right whales, 
which is important for right whale migration in March, April, November 
and December; this important migratory area is comprised of the waters 
of the continental shelf offshore the East Coast of the United States 
and extends from Florida through Massachusetts. Based on the proposed 
survey schedule (May through December), the majority of the survey 
would occur outside the months when the BIA is considered important for 
right whale migration.
    NMFS' regulations at 50 CFR part 224.105 designated nearshore 
waters of the Mid-Atlantic Bight as Mid-Atlantic U.S. Seasonal 
Management Areas (SMA) for right whales in 2008. SMAs were developed to 
reduce the threat of collisions between ships and right whales around 
their migratory route and calving grounds. Within SMAs, mandatory 
vessel speed restrictions (less than 10 kn) are in place for vessels 
greater than 65 ft. A portion of one SMA overlaps spatially with the 
northern section of the proposed survey area. This SMA, which occurs 
off the mouth of the Delaware Bay, is active from November 1 through 
April 30 of each year. Any survey vessels greater than 65 ft in length 
would be required to adhere to the mandatory vessel speed restrictions 
when operating within the SMA (when the SMA is active from November 1 
through April 30).
    The current abundance estimate for this stock is 458 individuals 
(Hayes et al., 2018). Data indicates that the number of adult females 
fell from 200 in 2010 to 186 in 2015 while males fell from 283 to 272 
in the same timeframe (Pace et al., 2017). In addition, elevated North 
Atlantic right whale mortalities have occurred since June 7, 2017, 
including a total of 17 confirmed dead stranded whales (12 in Canada; 5 
in the United States), and an additional 5 live whale entanglements in 
Canada, documented to date. This event has been declared an Unusual 
Mortality Event (UME). More information is available online at: https://www.nmfs.noaa.gov/pr/health/mmume/2017northatlanticrightwhaleume.html.

Humpback Whale

    Humpback whales are found worldwide in all oceans. The humpback 
whale population within the North Atlantic has been estimated to 
include approximately 11,570 individuals (Waring et al., 2016). 
Humpback whales utilize the mid-Atlantic as a migration pathway between 
calving/mating grounds to the south and feeding grounds in the north 
(Waring et al. 2007). During winter, the majority of humpback whales 
from North Atlantic feeding areas (including the Gulf of Maine) mate 
and calve in the West Indies, where spatial and genetic mixing among 
feeding groups occurs, though significant numbers of animals are found 
in mid- and high-latitude regions at this time and some individuals 
have been sighted repeatedly within the same winter season indicating 
that not all humpback whales migrate south every winter (Waring et al., 
2016).
    A key question with regard to humpback whales off the mid-Atlantic 
states is their stock identity. Using fluke photographs of living and 
dead whales observed in the region, Barco et al. (2002) reported that 
43 percent of 21 live whales matched to the Gulf of Maine, 19 percent 
to Newfoundland, and 4.8 percent to the Gulf of St Lawrence, while 31.6 
percent of 19 dead humpbacks were known Gulf of Maine whales. Although 
the population composition of the mid-Atlantic is apparently dominated 
by Gulf of Maine whales, lack of photographic effort in Newfoundland 
makes it likely that the observed match rates under-represent the true 
presence of Canadian whales in the region (Waring et al., 2016). Barco 
et al. (2002) suggested that the mid-Atlantic region primarily 
represents a supplemental winter feeding ground used by humpbacks.
    Since January 2016, elevated humpback whale mortalities have 
occurred along the Atlantic coast from Maine through North Carolina. 
Partial or full necropsy examinations have been conducted on 
approximately half of the 62 known cases. A portion of the whales have 
shown evidence of pre-mortem vessel strike; however, this finding is

[[Page 14424]]

not consistent across all of the whales examined so more research is 
needed. NOAA is consulting with researchers that are conducting studies 
on the humpback whale populations, and these efforts may provide 
information on changes in whale distribution and habitat use that could 
provide additional insight into how these vessel interactions occurred. 
Three previous UMEs involving humpback whales have occurred since 2000, 
in 2003, 2005, and 2006. More information is available at 
www.nmfs.noaa.gov/pr/health/mmume/2017humpbackatlanticume.html.

Fin Whale

    Fin whales are common in waters of the U.S. Atlantic Exclusive 
Economic Zone (EEZ), principally from Cape Hatteras northward (Waring 
et al., 2016). Fin whales are present north of 35-degree latitude in 
every season and are broadly distributed throughout the western North 
Atlantic for most of the year (Waring et al., 2016). Fin whales are 
found in small groups of up to 5 individuals (Brueggeman et al., 1987). 
The main threats to fin whales are fishery interactions and vessel 
collisions (Waring et al., 2016).

Sei Whale

    The Nova Scotia stock of sei whales can be found in deeper waters 
of the continental shelf edge waters of the northeastern U.S. and 
northeastward to south of Newfoundland. The southern portion of the 
stock's range during spring and summer includes the Gulf of Maine and 
Georges Bank. Spring is the period of greatest abundance in U.S. 
waters, with sightings concentrated along the eastern margin of Georges 
Bank and into the Northeast Channel area, and along the southwestern 
edge of Georges Bank in the area of Hydrographer Canyon (Waring et al., 
2015). Sei whales occur in shallower waters to feed. Sei whales are 
listed as engendered under the ESA, and the Nova Scotia stock is 
considered strategic and depleted under the MMPA. The main threats to 
this stock are interactions with fisheries and vessel collisions.

Minke Whale

    Minke whales can be found in temperate, tropical, and high-latitude 
waters. The Canadian East Coast stock can be found in the area from the 
western half of the Davis Strait (45[deg] W) to the Gulf of Mexico 
(Waring et al., 2016). This species generally occupies waters less than 
100 m deep on the continental shelf. There appears to be a strong 
seasonal component to minke whale distribution in which spring to fall 
are times of relatively widespread and common occurrence, and when the 
whales are most abundant in New England waters, while during winter the 
species appears to be largely absent (Waring et al., 2016). The main 
threats to this stock are interactions with fisheries, strandings, and 
vessel collisions.

Sperm Whale

    The distribution of the sperm whale in the U.S. EEZ occurs on the 
continental shelf edge, over the continental slope, and into mid-ocean 
regions (Waring et al., 2014). The basic social unit of the sperm whale 
appears to be the mixed school of adult females plus their calves and 
some juveniles of both sexes, normally numbering 20-40 animals in all. 
There is evidence that some social bonds persist for many years 
(Christal et al., 1998). This species forms stable social groups, site 
fidelity, and latitudinal range limitations in groups of females and 
juveniles (Whitehead, 2002). In summer, the distribution of sperm 
whales includes the area east and north of Georges Bank and into the 
Northeast Channel region, as well as the continental shelf (inshore of 
the 100-m isobath) south of New England. In the fall, sperm whale 
occurrence south of New England on the continental shelf is at its 
highest level, and there remains a continental shelf edge occurrence in 
the mid-Atlantic bight. In winter, sperm whales are concentrated east 
and northeast of Cape Hatteras. The current abundance estimate for this 
stock is 2,288 (Hayes et al., 2017).

Long-Finned Pilot Whale

    Long-finned pilot whales are found from North Carolina and north to 
Iceland, Greenland and the Barents Sea (Waring et al., 2016). In U.S. 
Atlantic waters the species is distributed principally along the 
continental shelf edge off the northeastern U.S. coast in winter and 
early spring and in late spring, pilot whales move onto Georges Bank 
and into the Gulf of Maine and more northern waters and remain in these 
areas through late autumn (Waring et al., 2016). Long-finned pilot 
whales are not listed under the ESA. The Western North Atlantic stock 
is considered strategic under the MMPA. The main threats to this 
species include interactions with fisheries and habitat issues 
including exposure to high levels of polychlorinated biphenyls and 
chlorinated pesticides, and toxic metals including mercury, lead, 
cadmium, and selenium (Waring et al., 2016).

Atlantic White-Sided Dolphin

    White-sided dolphins are found in temperate and sub-polar waters of 
the North Atlantic, primarily in continental shelf waters to the 100-m 
depth contour from central West Greenland to North Carolina (Waring et 
al., 2016). The Gulf of Maine stock is most common in continental shelf 
waters from Hudson Canyon to Georges Bank, and in the Gulf of Maine and 
lower Bay of Fundy. Sighting data indicate seasonal shifts in 
distribution (Northridge et al., 1997). During January to May, low 
numbers of white-sided dolphins are found from Georges Bank to Jeffreys 
Ledge (off New Hampshire), with even lower numbers south of Georges 
Bank, as documented by a few strandings collected on beaches of 
Virginia to South Carolina. From June through September, large numbers 
of white-sided dolphins are found from Georges Bank to the lower Bay of 
Fundy. From October to December, white-sided dolphins occur at 
intermediate densities from southern Georges Bank to southern Gulf of 
Maine (Payne and Heinemann 1990). Sightings south of Georges Bank, 
particularly around Hudson Canyon, occur year round but at low 
densities. The main threat to this species is interactions with 
fisheries.

Atlantic Spotted Dolphin

    Atlantic spotted dolphins are found in tropical and warm temperate 
waters ranging from southern New England, south to Gulf of Mexico and 
the Caribbean to Venezuela (Waring et al., 2014). This stock regularly 
occurs in continental shelf waters south of Cape Hatteras and in 
continental shelf edge and continental slope waters north of this 
region (Waring et al., 2014). There are two forms of this species, with 
the larger ecotype inhabiting the continental shelf and is usually 
found inside or near the 200 m isobaths (Waring et al., 2014). Atlantic 
spotted dolphins are not listed under the ESA, and the stock is not 
considered depleted or strategic under the MMPA. The main threat to 
this species is interactions with fisheries.

Short-Beaked Common Dolphin

    The short-beaked common dolphin is found world-wide in temperate to 
subtropical seas. In the North Atlantic, short-beaked common dolphins 
are commonly found over the continental shelf between the 100-m and 
2000-m isobaths and over prominent underwater topography and east to 
the mid-Atlantic Ridge (Waring et al., 2016). Only the western North 
Atlantic stock may be present in the Lease Area. The current abundance 
estimate for this

[[Page 14425]]

stock is 70,184 animals (Hayes et al., 2017). The main threat to this 
species is interactions with fisheries.

Bottlenose Dolphin

    There are two distinct bottlenose dolphin morphotypes in the 
western North Atlantic: the coastal and offshore forms (Waring et al., 
2016). The offshore form is distributed primarily along the outer 
continental shelf and continental slope in the Northwest Atlantic Ocean 
from Georges Bank to the Florida Keys. The coastal morphotype is 
morphologically and genetically distinct from the larger, more robust 
morphotype that occupies habitats further offshore. Spatial 
distribution data, tag-telemetry studies, photo-ID studies and genetic 
studies demonstrate the existence of a distinct Northern Migratory 
stock of coastal bottlenose dolphins (Waring et al., 2014). During 
summer months (July-August), this stock occupies coastal waters from 
the shoreline to approximately the 25 m isobath between the Chesapeake 
Bay mouth and Long Island, New York; during winter months (January-
March), the stock occupies coastal waters from Cape Lookout, North 
Carolina, to the North Carolina/Virginia border (Waring et al., 2014). 
The Western North Atlantic northern migratory coastal stock and the 
Western North Atlantic offshore stock may be encountered by the 
proposed survey.
    The main threat to bottlenose dolphins is interactions with 
fisheries. Bottlenose dolphins are not listed as threatened or 
endangered under the ESA. The Western North Atlantic offshore stock is 
not a strategic stock under the MMPA, but the Northern Migratory 
Coastal Stock is a strategic stock under the MMPA due to the depleted 
listing under the MMPA.

Harbor Porpoise

    In the Lease Area, only the Gulf of Maine/Bay of Fundy stock may be 
present. This stock is found in U.S. and Canadian Atlantic waters and 
is concentrated in the northern Gulf of Maine and southern Bay of Fundy 
region, generally in waters less than 150 m deep (Waring et al., 2016). 
They are seen from the coastline to deep waters (>1800 m; Westgate et 
al. 1998), although the majority of the population is found over the 
continental shelf (Waring et al., 2016). The current abundance estimate 
for this stock is 79,883 (Hayes et al., 2017). The main threat to the 
species is interactions with fisheries, with documented take in the 
U.S. northeast sink gillnet, mid-Atlantic gillnet, and northeast bottom 
trawl fisheries and in the Canadian herring weir fisheries (Waring et 
al., 2016).

Harbor Seal

    The harbor seal is found in all nearshore waters of the North 
Atlantic and North Pacific Oceans and adjoining seas above about 
30[deg] N (Burns, 2009). In the western North Atlantic, harbor seals 
are distributed from the eastern Canadian Arctic and Greenland south to 
southern New England and New York, and occasionally to the Carolinas 
(Waring et al., 2016). Haulout and pupping sites are located off 
Manomet, MA and the Isles of Shoals, ME, but generally do not occur in 
areas in southern New England (Waring et al., 2016). The current 
abundance estimate for this stock is 75,834 (Hayes et al., 2017). The 
main threat to this species is interactions with fisheries.

Gray Seal

    There are three major populations of gray seals found in the world; 
eastern Canada (western North Atlantic stock), northwestern Europe and 
the Baltic Sea. Gray seals in the survey area belong to the western 
North Atlantic stock. The range for this stock is thought to be from 
New Jersey to Labrador. Though gray seals are not regularly sighted in 
Delaware their range has been expanding southward in recent years, and 
they have been observed recently as far south as the barrier islands of 
Virginia. Current population trends show that gray seal abundance is 
likely increasing in the U.S. Atlantic EEZ (Waring et al., 2016). 
Although the rate of increase is unknown, surveys conducted since their 
arrival in the 1980s indicate a steady increase in abundance in both 
Maine and Massachusetts (Waring et al., 2016). It is believed that 
recolonization by Canadian gray seals is the source of the U.S. 
population (Waring et al., 2016).

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2016) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 dB 
threshold from the normalized composite audiograms, with the exception 
for lower limits for low-frequency cetaceans where the lower bound was 
deemed to be biologically implausible and the lower bound from Southall 
et al. (2007) retained. The functional groups and the associated 
frequencies are indicated below (note that these frequency ranges 
correspond to the range for the composite group, with the entire range 
not necessarily reflecting the capabilities of every species within 
that group):
     Low-frequency cetaceans (mysticetes): Generalized hearing 
is estimated to occur between approximately 7 Hertz (Hz) and 35 
kilohertz (kHz);
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Generalized hearing is estimated to occur 
between approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; including two members 
of the genus Lagenorhynchus, on the basis of recent echolocation data 
and genetic data): Generalized hearing is estimated to occur between 
approximately 275 Hz and 160 kHz.
     Pinnipeds in water; Phocidae (true seals): Generalized 
hearing is estimated to occur between approximately 50 Hz to 86 kHz;
    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2016) for a review of available information. 
Eleven marine mammal species (nine cetacean and two pinniped (both 
phocid) species) have the reasonable potential to co-occur with the 
proposed survey activities. Please refer to Table 2. Of the cetacean 
species that may be present, five are classified as low-frequency 
cetaceans

[[Page 14426]]

(i.e., all mysticete species), six are classified as mid-frequency 
cetaceans (i.e., all delphinid species and the sperm whale), and one is 
classified as a high-frequency cetacean (i.e., harbor porpoise).

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity may impact marine mammals and 
their habitat. The ``Estimated Take'' section later in this document 
includes a quantitative analysis of the number of individuals that are 
expected to be taken by this activity. The ``Negligible Impact Analysis 
and Determination'' section considers the content of this section, the 
``Estimated Take'' section, and the ``Proposed Mitigation'' section, to 
draw conclusions regarding the likely impacts of these activities on 
the reproductive success or survivorship of individuals and how those 
impacts on individuals are likely to impact marine mammal species or 
stocks.

Background on Sound

    Sound is a physical phenomenon consisting of minute vibrations that 
travel through a medium, such as air or water, and is generally 
characterized by several variables. Frequency describes the sound's 
pitch and is measured in Hz or kHz, while sound level describes the 
sound's intensity and is measured in decibels (dB). Sound level 
increases or decreases exponentially with ea