Small Takes of Marine Mammals Incidental to Specified Activities; Cape Wind's High Resolution Survey in Nantucket Sound, MA, 7402-7411 [2013-02195]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 78, Number 22 (Friday, February 1, 2013)]
[Notices]
[Pages 7402-7411]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-02195]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XC430


Small Takes of Marine Mammals Incidental to Specified Activities; 
Cape Wind's High Resolution Survey in Nantucket Sound, MA

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

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

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SUMMARY: NMFS has received an application from Cape Wind Associates 
(CWA) for an Incidental Harassment Authorization (IHA) to take marine 
mammals, by harassment, incidental to pre-construction high resolution 
survey activities. CWA began pre-construction activities last year, but 
was unable to complete the entire survey. Pursuant to the Marine Mammal 
Protection Act (MMPA), NMFS is requesting comments on its proposal to 
issue a second IHA to CWA to incidentally take, by Level B harassment 
only, marine mammals during the specified activity.

DATES: Comments and information must be received no later than March 4, 
2013.

ADDRESSES: Comments on the application and this proposal should be 
addressed to Michael Payne, Chief, Permits and Conservation Division, 
Office of Protected Resources, National Marine Fisheries Service, 1315 
East-West Highway, Silver Spring, MD 20910-3225. The mailbox address 
for providing email comments is ITP.Magliocca@noaa.gov. NMFS is not 
responsible for email comments sent to addresses other than the one 
provided here. Comments sent via email, including all attachments, must 
not exceed a 10-megabyte file size.
    Instructions: All comments received are a part of the public record 
and will generally be posted to https://www.nmfs.noaa.gov/pr/permits/incidental.htm without change. All Personal Identifying Information 
(for example, name, address, etc.) voluntarily submitted by the 
commenter may be publicly accessible. Do not submit Confidential 
Business Information or otherwise sensitive or protected information.
    A copy of the application containing a list of the references used 
in this document may be obtained by visiting the internet at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm. The following associated 
documents are also

[[Page 7403]]

available at the same internet address: 2011 Environmental Assessment. 
Documents cited in this notice may also be viewed, by appointment, 
during regular business hours, at the aforementioned address.

FOR FURTHER INFORMATION CONTACT: Michelle Magliocca, Office of 
Protected Resources, NMFS, (301) 427-8401.

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 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 specific 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.
    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.''
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the U.S. can apply for a 1-year authorization to 
incidentally take small numbers of marine mammals by harassment, 
provided that there is no potential for serious injury or mortality to 
result from the activity. Section 101(a)(5)(D) establishes a 45-day 
time limit for NMFS review of an application followed by a 30-day 
public notice and comment period on any proposed authorizations for the 
incidental harassment of marine mammals. Within 45 days of the close of 
the comment period, NMFS must either issue or deny the authorization.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment].

Summary of Request

    On December 19, 2012, NMFS received an application from CWA for the 
taking of marine mammals incidental to high resolution survey 
activities. NMFS determined that the application was adequate and 
complete on December 31, 2012.
    CWA proposes to conduct a high resolution geophysical survey in 
Nantucket Sound, Massachusetts. The proposed activity would occur 
during daylight hours over an estimated 109-day period beginning in 
April 2013. The following equipment used during the survey is likely to 
result in the take of marine mammals: Shallow-penetration subbottom 
profiler and medium-penetration subbottom profiler. Take, by Level B 
harassment only, of individuals of five species is anticipated to 
result from the specified activity. This request is basically an 
extension of the request made in April 2011 for survey activities that 
were not completed under the previous IHA. CWA is not proposing to 
change their survey activities in any way. However, the geotechnical 
portion of the survey was completed in 2012 and would not be continued 
during the 2013 season.

Description of the Specified Activity

    CWA proposes to conduct a high resolution geophysical survey in 
order to acquire remote-sensing data around Horseshoe Shoal which would 
be used to characterize resources at or below the seafloor. The purpose 
of the survey would be to identify any submerged cultural resources 
that may be present and to generate additional data describing the 
geological environment within the survey area. The survey would satisfy 
the mitigation and monitoring requirements for ``cultural resources and 
geology'' in the environmental stipulations of the Bureau of Ocean 
Energy Management, Regulation, and Enforcement's lease. The survey is 
part of the first phase of a larger Cape Wind energy project, which 
involves the installation of 130 wind turbine generators on Horseshoe 
Shoal over a 2-year period. The survey would collect data along 
predetermined track lines using a towed array of instrumentation, which 
would include a side scan sonar, magnetometer, shallow-penetration 
subbottom profiler, multibeam depth sounder, and medium-penetration 
subbottom profiler. The proposed high resolution geophysical survey 
activities would not result in any disturbance to the sea floor.

Dates and Duration

    Survey activities are necessary prior to construction of the wind 
turbine array and are scheduled to begin in the spring of 2013, 
continuing on a daily basis for up to five months. Survey vessels would 
operate during daytime hours only and CWA estimates that one survey 
vessel would cover about 17 Nautical miles (31 kilometers) of track 
line per day. Therefore, CWA conservatively estimates that survey 
activities would take 109 days (28 days less than what was expected 
under the 2012 IHA). However, if more than one survey vessel is used, 
the survey duration would be considerably shorter. NMFS is proposing to 
issue an authorization that extends from April 1, 2013, to March 31, 
2014.

Location

    Survey vessels are expected to depart from Falmouth Harbor, 
Massachusetts, or another nearby harbor on Cape Cod. In total, the 
survey would cover approximately 110 square kilometers (km\2\). This 
area includes the future location of the wind turbine generators--an 
area about 8.4 km from Point Gammon, 17.7 km from Nantucket Island, and 
8.9 km from Martha's Vineyard--and cables connecting the wind park to 
the mainland. The survey area within the wind park would be transited 
by survey vessels towing specialized equipment along primary track 
lines and perpendicular tie lines. Preliminary survey designs include 
primary track lines with northwest-southeast orientations and assume 
30-meter (m) line spacing. Preliminary survey designs also call for tie 
lines to likely run in a west-east orientation covering targeted areas 
of the construction footprint where wind turbine generators would be 
located. The survey area along the interconnecting submarine cable 
route includes a construction and anchoring corridor, as part of the 
wind farm's area of potential effect. The total track line distance 
covered during the survey is estimated to be about 3,432 km (as opposed 
to the 4,292 km included in the 2012 IHA).
    Multiple survey vessels may operate within the survey area and 
would travel at about 3 knots during data acquisition and approximately 
15 knots during transit between the survey area and port. If multiple 
vessels are used at the same time, they would be far enough apart that 
sounds from the chirp and

[[Page 7404]]

boomer would not overlap. The survey vessels would acquire data 
continuously throughout the survey area during the day and terminate 
survey activities before dark, prior to returning to port. NMFS 
believes that the likelihood of a survey vessel striking a marine 
mammal is low considering the low marine mammal densities within 
Nantucket Sound, the relatively short distance from port to the survey 
site, the limited number of vessels, and the small vessel size. Vessel 
sounds during survey activities would result from propeller 
cavitations, propeller singing, propulsion, flow noise from water 
dragging across the hull, and bubbles breaking in the wake. The 
dominant sound source from vessels would be from propeller cavitations; 
however, sounds resulting from survey vessel activity are considered to 
be no louder than the existing ambient sound levels and sound generated 
from regular shipping and boating activity in Nantucket Sound (MMS, 
2009).
    NMFS expects that acoustic stimuli resulting from the operation of 
the survey equipment have the potential to harass marine mammals. 
Background information on the characteristics and measurement of sound 
are provided later in this document. The dominant sources of sound 
during the proposed survey activities would be from the towed equipment 
used to gather seafloor data. Two of the seismic survey devices used 
during the high resolution geophysical survey emit sounds within the 
hearing range of marine mammals in Nantucket Sound: Shallow-penetration 
and medium-penetration subbottom profilers (known as a ``chirp'' and 
``boomer,'' respectively). CWA would use a chirp to provide high 
resolution data of the upper 15 m of sea bottom. An EdgeTech 216S or 
similar model would be used. The chirp would be towed near the center 
of the survey vessel directly adjacent to the gunwale of the boat, 
about 1 to 1.5 m beneath the water's surface. Sources such as the chirp 
are considered non-impulsive, intermittent (as opposed to continuous) 
sounds. The frequency range for this instrument is generally 2 to 16 
kilohertz (kHz)--a range audible by all marine mammal species in 
Nantucket Sound. The estimated sound pressure level at the source would 
be 201 dB re 1 [mu]Pa at 1 m with a typical pulse length of 32 
milliseconds and a pulse repetition rate of 4 per second. NMFS does not 
consider the chirp to be a continuous sound source (best represented by 
vibratory pile driving or drilling). CWA would use a boomer to obtain 
deeper resolution of geologic layering that cannot be imaged by the 
chirp. An AP3000 (dual plate) boomer, or similar model would be used. 
The boomer would be towed about 3 to 5 m behind the survey vessel's 
stern at the water's surface. Unlike the chirp, the boomer emits an 
impulse sound, characterized by a relatively rapid rise-time to maximum 
pressure followed by a period of diminishing and oscillating pressures 
(Southall et al., 2007). The boomer has a broad frequency range of 0.3 
to 14 kHz--a range audible by all marine mammal species in Nantucket 
Sound. CWA performed sound source verification monitoring in 2012 on 
the type of chirp and boomer that would be used during the 2013 survey 
season. Underwater sound was recorded with two Autonomous Multichannel 
Acoustic Recorders, deployed 100 m apart, in the vicinity of the 
project area. The received 90-percent rms sound pressure levels (SPLs) 
from the subbottom profilers did not exceed 175 dB re 1uPa. The loudest 
source, the dual-plate boomer, produced a received 90-percent rms SPL 
of less than 140 dB re 1 uPa at a 500-m range. The distance to the 160-
dB isopleth was 12 m for the dual-plate boomer and 10 m for the chirp.

Description of Marine Mammals in the Area of the Specified Activity

    All marine mammals with possible or confirmed occurrence in the 
proposed activity area are listed in Table 1, along with their status 
under the Endangered Species Act (ESA) and MMPA. In general, large 
whales do not frequent Nantucket Sound, but they are discussed below 
because some species have been reported near the project vicinity.

           Table 1--Marine Mammals With Possible or Confirmed Occurrence in the Proposed Activity Area
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             Common name                   Scientific name             ESA status              MMPA status
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Humpback whale.......................  Megaptera novaeangilae.  endangered.............  depleted.
Fin whale............................  Balaenoptera physalus..  endangered.............  depleted.
North Atlantic right whale...........  Eubaelena glacialis....  endangered.............  depleted.
Long-finned pilot whale..............  Globicephalus melas....
Minke whale..........................  Balaenoptera
                                        acutorostrata.
Atlantic white-sided dolphin.........  Lagenorhynchus acutus..
Striped dolphin......................  Stellena coeruleoalba..
Common dolphin.......................  Delphinus delphis......
Harbor porpoise......................  Phocoena phocoena......
Atlantic spotted dolphin.............  Stenella frontalis.....
Risso's dolphin......................  Grampus griseus........
Dwarf and pygmy sperm whale..........  Kogia spp..............
Gray seal............................  Halichoerus grypus.....
Harbor seal..........................  Phoca vitulina.........
Harp seal............................  Phoca groenlandica.....
Hooded seal..........................  Crystophora cristata...
----------------------------------------------------------------------------------------------------------------

    Sightings data indicate that whales rarely visit Nantucket Sound 
and there are no sightings of large whales on Horseshoe Shoal. Since 
2002, no humpback whales have been observed anywhere in Nantucket Sound 
and there are no documented occurrences of fin whales within Nantucket 
Sound. Right whales are considered rare in Nantucket Sound and have not 
been sighted on Horseshoe Shoal. All of the right whales observed in 
Nantucket Sound during 2010 quickly transited the area and there is no 
evidence of any persistent aggregations around the proposed project 
area. The best available science indicates that humpback whales, fin 
whales, and right whales--although present in the New England region--
are rare in Nantucket Sound and transient individuals may be 
occasionally found 20 km from the proposed project area; this is likely 
due to the shallow depths of Nantucket Sound and its location outside 
of the coastal migratory corridor.

[[Page 7405]]

    Likewise, sightings data shows no record of long-finned pilot 
whales, striped dolphins, Atlantic spotted dolphins, common dolphins, 
Risso's dolphins, Kogia species, harp seals, or hooded seals in 
Nantucket Sound, although these stocks exist in the New England region. 
Therefore, CWA is not requesting, nor is NMFS proposing, take for the 
aforementioned species.
    Marine mammals with known occurrences in Nantucket Sound that could 
be harassed by high resolution geophysical survey activity in Nantucket 
Sound are listed in Table 2. These are the species for which take is 
being requested.

             Table 2--Marine Mammals That Could Be Impacted by Survey Activities in Nantucket Sound
----------------------------------------------------------------------------------------------------------------
                                                                                             Time of year in New
           Common name              Scientific name       Abundance      Population status         England
----------------------------------------------------------------------------------------------------------------
Minke whale.....................  Balaenoptera                  8,987  stable..............  April through
                                   actuorostrata.                                             October.
Atlantic white-sided dolphin....  Lagenorhynchus               63,000  n/a.................  October through
                                   acutus.                                                    December.
Harbor porpoise.................  Phocoena phocoena..          89,504  n/a.................  Year-round (peak
                                                                                              Sept-Apr).
Gray seal.......................  Halichoerus grypis.         250,000  increasing..........  Year-round.
Harbor seal.....................  Phoca vitulina.....          99,340  n/a.................  October through
                                                                                              April.
----------------------------------------------------------------------------------------------------------------

Minke Whales

    In the North Atlantic, minke whales are found from Canada to the 
Gulf of Mexico and concentrated in New England waters, particularly in 
the spring and summer months. Minke whales found in Nantucket Sound are 
part of the Canadian East Coast stock, which runs from the Davis Strait 
down to the Gulf of Mexico. The best available abundance estimate for 
this stock is 8,987 individuals. Sightings data indicate that minke 
whales prefer shallower waters when in the Cape Cod vicinity, but 
depths significantly greater than Nantucket Sound. Sightings per unit 
effort estimates for Nantucket Sound are 0.1 to 5.9 minke whales per 
1,000 km of survey track for spring and summer. However, estimates may 
be biased due to heavier whale watching activities during those months. 
Minke whales are one of the most abundant whale species in the world 
and their population is considered stable throughout. The minke whale 
is not listed under the ESA nor considered strategic under the MMPA.

Atlantic White-Sided Dolphin

    Atlantic white-sided dolphins are found in temperate and sub-polar 
waters of the North Atlantic, typically along the continental shelf and 
slope. In the western North Atlantic, they are found from North 
Carolina to Greenland. During summer months, Atlantic white-sided 
dolphins move north and closer to shore. Atlantic white-sided dolphins 
are rare in Nantucket Sound, but are found in deeper waters around 
Massachusetts and Rhode Island. In 2011, the estimated population size 
of the Western North Atlantic stock was about 23,390 animals. There is 
insufficient data to determine population trends, but Atlantic white-
sided dolphins are not listed under the ESA, although they are 
considered strategic under the MMPA.

Harbor Porpoises

    Harbor porpoises have a wide and discontinuous range that includes 
the North Atlantic and North Pacific. In the western North Atlantic, 
harbor porpoises are found from Greenland to Cape Hatteras, North 
Carolina. Harbor porpoises in U.S. waters are divided into 10 stocks, 
based on genetics, movement patterns, and management. Any harbor 
porpoises encountered during the proposed survey activities would be 
part of the Gulf of Maine/Bay of Fundy stock which has an estimated 
abundance of 89,054 animals and a minimum population estimate of 60,970 
(NMFS, 2011c). They congregate around the Gulf of Maine during summer 
months, but are otherwise dispersed along the east coast. No trend 
analyses exist for this species. Harbor porpoises are not listed under 
the ESA although they are considered strategic under the MMPA.

Gray Seals

    Gray seals inhabit temperate and sub-arctic waters. They are found 
from Maine to Long Island Sound, live on remote, exposed islands, 
shoals, and unstable sandbars, and are the second most common pinniped 
along the U.S. Atlantic coast. Three major populations exist in eastern 
Canada, northwestern Europe, and the Baltic Sea. The western North 
Atlantic stock is equivalent to the eastern Canada population and 
ranges from New York to Labrador. Pupping occurs on land or ice from 
late December through mid-February with peaks in mid-January. Muskeget 
Island (located between Martha's Vineyard and Nantucket Island) and 
Monomoy Island (at the eastern limit of Nantucket Sound) are the only 
gray seal breeding colonies in the U.S. and the southernmost gray seal 
breeding colonies in the world. These breeding colonies are about 24 km 
and 14 km from the proposed project site, respectively. Gray seals 
presently use the islands as areas to give birth and raise their pups. 
There is no defined migratory behavior for gray seals, so a large 
portion of the population may be present in Nantucket Sound year-round. 
Some adults move north during spring and summer, out of Nantucket Sound 
to the waters off Maine and Canada, but others have been observed in 
high abundance in Chatham Harbor, MA and other areas of lower Cape Cod 
during this time.
    Incidental observations of seals were recorded during avian aerial 
surveys conducted independently by CWA and the Massachusetts Audubon 
Society. Between May 2002 and February 2004, CWA conducted about 46 
aerial avian surveys in Nantucket Sound, with particular focus on 
Horseshoe Shoal. During this time, about 26,873 seals were observed 
throughout Nantucket Sound; about 56 of these were observed within the 
proposed project area over the three-year period. Current population 
numbers for the western North Atlantic stock are unknown, but some pup 
surveys suggest about 223,220 animals. Gray seal numbers are increasing 
in coastal waters between southern Massachusetts and eastern Long 
Island. Their abundance is likely increasing throughout the western 
Atlantic, but the rate of increase is unknown. Gray seals are not 
listed under the ESA, nor considered strategic under the MMPA.

Harbor Seals

    Harbor seals, also known as common seals, are found throughout 
coastal waters of the Atlantic Ocean and considered the most abundant 
pinniped on the U.S. east coast. The best available estimate for the 
harbor seal population along the New England coast is 99,340 (NMFS, 
2011f). They are most common around coastal islands, ledges, and 
sandbars above 30[deg] N latitude and range

[[Page 7406]]

from the Arctic down to Nantucket Sound. Harbor seals are seasonal 
visitors to Massachusetts; breeding and pupping occur through the 
spring and summer in Maine and Canada. Harbor seals typically over-
winter in Massachusetts, but some remain in southern New England year-
round. No pupping areas have been identified in southern New England. 
Extensive sand spits off Muskeget Island and neighboring Tuckernuck and 
Skiff Islands have been identified as preferred haul-out spots for 
large numbers of harbor seals.
    Harbor seal abundance estimates for Nantucket Sound are scarce. 
Barlas (1999) observed harbor seals on Cape Cod from October through 
April and saw abundance peak in March, with very few individuals using 
haul-out sites in Nantucket Sound. Waring (unpublished data, 2002) 
observed an increased abundance of harbor seals on Muskeget Island, 
Monomoy Island, and Tuckernuck Island in 1999 and 2000; however, harbor 
seals are not likely to be in the same area when gray seals are 
breeding.
    Further information on the biology and local distribution of these 
species and others in the region can be found in CWA's application, 
which is available online at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications, and the NMFS Marine Mammal Stock 
Assessment Reports, which are available online at: https://www.nmfs.noaa.gov/pr/species.

Potential Effects of the Specified Activity on Marine Mammals

    Use of subbottom profilers on Horseshoe Shoal may temporarily 
impact marine mammal behavior within the survey area due to elevated 
in-water sound levels. Marine mammals are continually exposed to many 
sources of sound. Naturally occurring sounds such as lightning, rain, 
sub-sea earthquakes, and biological sounds (for example, snapping 
shrimp, whale songs) are widespread throughout the world's oceans. 
Marine mammals produce sounds in various contexts and use sound for 
various biological functions including, but not limited to, (1) social 
interactions; (2) foraging; (3) orientation; and (4) predator 
detection. Interference with producing or receiving these sounds may 
result in adverse impacts. Audible distance, or received levels of 
sound depend on the nature of the sound source, ambient noise 
conditions, and the sensitivity of the receptor to the sound 
(Richardson et al., 1995). Type and significance of marine mammal 
reactions to sound are likely dependent on a variety of factors 
including, but not limited to, (1) the behavioral state of the animal 
(for example, feeding, traveling, etc.); (2) frequency of the sound; 
(3) distance between the animal and the source; and (4) the level of 
the sound relative to ambient conditions (Southall et al., 2007).
    For background, 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 hertz (Hz) or kilohertz (kHz), while 
sound level describes the sound's intensity and is measured in decibels 
(dB). Sound level increases or decreases exponentially with each dB of 
change. The logarithmic nature of the scale means that each 10-dB 
increase is a 10-fold increase in acoustic power (and a 20-dB increase 
is then a 100-fold increase in power). A 10-fold increase in acoustic 
power does not mean that the sound is perceived as being 10 times 
louder, however. Sound levels are compared to a reference sound 
pressure (micro-Pascal) to identify the medium. For air and water, 
these reference pressures are ``re: 20 [mu]Pa'' and ``re: 1 [mu]Pa,'' 
respectively. Root mean square (RMS) is the quadratic mean sound 
pressure over the duration of an impulse. RMS is calculated by squaring 
all of the sound amplitudes, averaging the squares, and then taking the 
square root of the average (Urick, 1975). RMS accounts for both 
positive and negative values; squaring the pressures makes all values 
positive so that they may be accounted for in the summation of pressure 
levels (Hastings and Popper, 2005). This measurement is often used in 
the context of discussing behavioral effects, in part because 
behavioral effects, which often result from auditory cues, may be 
better expressed through averaged units rather than by peak pressures.
    Cetaceans are divided into three functional hearing groups: Low-
frequency, mid-frequency, and high-frequency. Minke whales are 
considered low-frequency cetaceans and their estimated auditory 
bandwidth (lower to upper frequency hearing cut-off) ranges from 7 Hz 
to 30 kHz. Atlantic white-sided dolphins are considered mid-frequency 
cetaceans and their estimated auditory bandwidth ranges from 150 Hz to 
160 kHz. Lastly, harbor porpoises are considered high-frequency 
cetaceans and their estimated auditory bandwidth ranges from 200 Hz to 
180 kHz. In contrast, pinnipeds are divided into two functional hearing 
groups: In-water and in-air. Pinnipeds in water have an estimated 
auditory bandwidth of 75 Hz to 75 kHz. There are no pinniped haul-outs 
close enough to the survey area to take in-air auditory bandwidths into 
consideration.

Hearing Impairment

    Marine mammals may experience temporary or permanent hearing 
impairment when exposed to loud sounds. Hearing impairment is 
classified by temporary threshold shift (TTS) and permanent threshold 
shift (PTS). There are no empirical data for onset of PTS in any marine 
mammal; therefore, PTS-onset must be estimated from TTS-onset 
measurements and from the rate of TTS growth with increasing exposure 
levels above the level eliciting TTS-onset. PTS is presumed to be 
likely if the hearing threshold is reduced by >= 40 dB (that is, 40 dB 
of TTS). PTS is considered auditory injury (Southall et al., 2007) and 
occurs in a specific frequency range and amount. Irreparable damage to 
the inner or outer cochlear hair cells may cause PTS; however, other 
mechanisms are also involved, such as exceeding the elastic limits of 
certain tissues and membranes in the middle and inner ears and 
resultant changes in the chemical composition of the inner ear fluids 
(Southall et al., 2007). Due to proposed mitigation measures and source 
levels, NMFS does not expect marine mammals to be exposed to PTS levels 
during the proposed survey activities.

Temporary Threshold Shift (TTS)

    TTS is the mildest form of hearing impairment that can occur during 
exposure to a loud sound (Kryter, 1985). While experiencing TTS, the 
hearing threshold rises and a sound must be stronger in order to be 
heard. At least in terrestrial mammals, TTS can last from minutes or 
hours to (in cases of strong TTS) days, can be limited to a particular 
frequency range, and can occur to varying degrees (i.e., a loss of a 
certain number of dBs of sensitivity). For sound exposures at or 
somewhat above the TTS threshold, hearing sensitivity in both 
terrestrial and marine mammals recovers rapidly after exposure to the 
noise ends.
    Marine mammal hearing plays a critical role in communication with 
conspecifics and in interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS and the context in which it is experienced, TTS 
can have effects on marine mammals ranging from discountable to 
serious. For example, a marine mammal may be able to readily compensate 
for a brief, relatively small amount of TTS

[[Page 7407]]

in a non-critical frequency range that takes place during a time when 
the animals is traveling through the open ocean, where ambient noise is 
lower and there are not as many competing sounds present. 
Alternatively, a larger amount and longer duration of TTS sustained 
during a time when communication is critical for successful mother/calf 
interactions could have more serious impacts if it were in the same 
frequency band as the necessary vocalizations and of a severity that it 
impeded communication. The fact that animals exposed to levels and 
durations of sound that would be expected to result in this 
physiological response would also be expected to have behavioral 
responses of a comparatively more severe or sustained nature is also 
notable and potentially of more importance than the simple existence of 
a TTS.
    Recent literature highlights the inherent complexity of predicting 
TTS onset in marine mammals, as well as the importance of considering 
exposure duration when assessing potential impacts (Mooney et al., 
2009a, 2009b; Kastak et al., 2007). Generally, with sound exposures of 
equal energy, quieter sounds (lower SPL) of longer duration were found 
to induce TTS onset more than louder sounds (higher SPL) of shorter 
duration (more similar to subbottom profilers). For intermittent 
sounds, less threshold shift will occur than from a continuous exposure 
with the same energy (some recovery will occur between intermittent 
exposures) (Kryter et al., 1966; Ward, 1997). For sound exposures at or 
somewhat above the TTS-onset threshold, hearing sensitivity recovers 
rapidly after exposure to the sound ends. Southall et al. (2007) 
considers a 6 dB TTS (that is, baseline thresholds are elevated by 6 
dB) to be a sufficient definition of TTS-onset. NMFS considers TTS as 
Level B harassment that is mediated by physiological effects on the 
auditory system; however, NMFS does not consider TTS-onset to be the 
lowest level at which Level B harassment may occur. Southall et al. 
(2007) summarizes underwater pinniped data from Kastak et al. (2005), 
indicating that a tested harbor seal showed a TTS of around 6 dB when 
exposed to a nonpulse noise at sound pressure level 152 dB re: 1 [mu]Pa 
for 25 minutes.
    Some studies suggest that harbor porpoises may be more sensitive to 
sound than other odontocetes (Lucke et al., 2009; Kastelein et al., 
2011). While TTS onset may occur in harbor porpoises at lower received 
levels (when compared to other odontocetes), NMFS 160-dB threshold 
criteria are based on the onset of behavioral harassment, not the onset 
of TTS. The potential for TTS is considered within NMFS' analysis of 
potential impacts from Level B harassment.

Behavioral Disturbance

    Behavioral responses to sound are highly variable and context-
specific. An animal's perception of and response to (in both nature and 
magnitude) an acoustic event can be influenced by prior experience, 
perceived proximity, bearing of the sound, familiarity of the sound, 
etc. (Southall et al., 2007). If a marine mammal does react briefly to 
an underwater sound by changing its behavior or moving a small 
distance, the impacts of the change are unlikely to be significant to 
the individual, let alone the stock or population. However, if a sound 
source displaces marine mammals from an important feeding or breeding 
area for a prolonged period, impacts on individuals and populations 
could be significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007). 
Given the many uncertainties in predicting the quantity and types of 
impacts of noise on marine mammals, it is common practice to estimate 
how many mammals would be present within a particular distance of 
activities and/or exposed to a particular level of sound. In most 
cases, this approach likely overestimates the numbers of marine mammals 
that would be affected in some biologically-important manner.
    The studies that address responses of low-frequency cetaceans (such 
as the minke whale) to non-pulse sounds include data gathered in the 
field and related to several types of sound sources (of varying 
similarity to chirps), including: Vessel noise, drilling and machinery 
playback, low-frequency M-sequences (sine wave with multiple phase 
reversals) playback, tactical low-frequency active sonar playback, 
drill ships, and non-pulse playbacks. These studies generally indicate 
no (or very limited) responses to received levels in the 90 to 120 dB 
re: 1[mu]Pa range and an increasing likelihood of avoidance and other 
behavioral effects in the 120 to 160 dB range. As mentioned earlier, 
though, contextual variables play a very important role in the reported 
responses and the severity of effects are not linear when compared to 
received level. Also, few of the laboratory or field datasets had 
common conditions, behavioral contexts, or sound sources, so it is not 
surprising that responses differ.
    The studies that address responses of mid-frequency cetaceans (such 
as Atlantic white-sided dolphins) to non-pulse sounds include data 
gathered both in the field and the laboratory and related to several 
different sound sources (of varying similarity to chirps) including: 
Pingers, drilling playbacks, ship and ice-breaking noise, vessel noise, 
Acoustic harassment devices (AHDs), Acoustic Deterrent Devices (ADDs), 
mid-frequency active sonar, and non-pulse bands and tones. Southall et 
al. (2007) were unable to come to a clear conclusion regarding the 
results of these studies. In some cases animals in the field showed 
significant responses to received levels between 90 and 120 dB, while 
in other cases these responses were not seen in the 120 to 150 dB 
range. The disparity in results was likely due to contextual variation 
and the differences between the results in the field and laboratory 
data (animals typically responded at lower levels in the field).
    The studies that address responses of high-frequency cetaceans 
(such as the harbor porpoise) to non-pulse sounds include data gathered 
both in the field and the laboratory and related to several different 
sound sources (of varying similarity to chirps), including: Pingers, 
AHDs, and various laboratory non-pulse sounds. All of these data were 
collected from harbor porpoises. Southall et al. (2007) concluded that 
the existing data indicate that harbor porpoises are likely sensitive 
to a wide range of anthropogenic sounds at low received levels (around 
90 to 120 dB), at least for initial exposures. All recorded exposures 
above 140 dB induced profound and sustained avoidance behavior in wild 
harbor porpoises (Southall et al., 2007). Rapid habituation was noted 
in some but not all studies.
    The studies that address the responses of pinnipeds in water to 
non-pulse sounds include data gathered both in the field and the 
laboratory and related to several different sound sources (of varying 
similarity to chirps), including: AHDs, various non-pulse sounds used 
in underwater data communication, underwater drilling, and construction 
noise. Few studies exist with enough information to include them in the 
analysis. The limited data suggest that exposures to non-pulse sounds 
between 90 and 140 dB generally do not result in strong behavioral 
responses of pinnipeds in water, but no data exist at higher received 
levels (Southall et al., 2007).
    Southall et al. (2007) also addressed behavioral responses of 
marine mammals to impulse sounds. The studies that address the 
responses of low-frequency cetaceans to impulse sounds include data 
gathered in the field and related to two sound sources: Airguns and 
explosions. The onset of

[[Page 7408]]

significant behavioral disturbance varied between 120 and 160 dB, 
depending on species. The studies that address the responses of mid-
frequency cetaceans to impulse sounds include data gathered both in the 
field and the laboratory and related to several different sound sources 
(of varying similarity to boomers), including: Small explosives, airgun 
arrays, pulse sequences, and natural and artificial pulses. The data 
show no clear indication of increasing probability and severity of 
response with increasing received level. Behavioral responses seem to 
vary depending on species and stimuli. Data on behavioral responses of 
high-frequency cetaceans to multiple pulses is not available. Although 
individual elements of some non-pulse sources (such as pingers) could 
be considered pulses, it is believed that some mammalian auditory 
systems perceive them as non-pulse sounds (Southall et al., 2007).
    The studies that address the responses of pinnipeds in water to 
impulse sounds include data gathered in the field and related to 
several different sources (of varying similarity to boomers), 
including: Small explosives, impact pile driving, and airgun arrays. 
Quantitative data on reactions of pinnipeds to impulse sounds is 
limited, but a general finding is that exposures in the 150 to 180 dB 
range generally have limited potential to induce avoidance behavior 
(Southall et al., 2007).
    Any impacts to marine mammal behavior are expected to be temporary. 
Animals may avoid the area around the survey vessels, thereby reducing 
exposure. Any disturbance to marine mammals is likely to be in the form 
of temporary avoidance or alteration of opportunistic foraging behavior 
near the survey location. In addition, because protected species 
observers would be monitoring a 500-m exclusion zone (much larger than 
the 30-m, 180-dB isopleth in which Level A harassment could occur), 
marine mammal injury or mortality is not anticipated. The protected 
species observers would be on watch to stop survey activities, a 
mitigation measure designed to prevent animals from being exposed to 
injurious level sounds. For these reasons, any changes to marine mammal 
behavior are expected to be temporary and result in a negligible impact 
to affected species and stocks.

Anticipated Effects on Habitat

    There is no anticipated impact on marine mammal habitat from the 
proposed survey activities. The high resolution geophysical survey 
equipment would not come in contact with the seafloor and would not be 
a source of air or water pollution. Marine mammals may avoid the survey 
area temporarily due to ensonification, but survey activities are not 
expected to result in long-term abandonment of marine mammal habitat. A 
negligible area of seafloor would be temporarily disturbed during the 
collection of geotechnical data.
    Overall, the proposed activity is not expected to cause significant 
impacts on marine mammal habitat or marine mammal prey species in the 
proposed survey area. Therefore, NMFS has preliminarily determined 
impacts to marine mammal habitat are negligible.

Proposed Mitigation

    In order to issue an incidental take authorization under section 
101(a)(5)(D) of the MMPA, NMFS must, where applicable, 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 subsistence uses where relevant.
    CWA proposed, with NMFS' guidance, the following mitigation 
measures to help ensure the least practicable adverse impact on marine 
mammals:

Establishment of an Exclusion Zone

    During all survey activities involving the shallow-penetration and 
medium-penetration subbottom profilers, CWA would establish a 500-m 
radius exclusion zone around each survey vessel. This area would be 
monitored for marine mammals 60 minutes (as stipulated by the BOEMRE 
lease) prior to starting or restarting surveys, and during surveys, and 
60 minutes after survey equipment has been turned off. Typically, the 
exclusion zone is based on the area in which marine mammals could be 
exposed to injurious (Level A) levels of sound. CWA's lease specifies a 
500-m exclusion zone, which exceeds both the estimated Level A and 
Level B isopleths for marine mammal harassment. CWA's proposed 
exclusion zone would minimize impacts to marine mammals from increased 
sound exposures. The exclusion zone must not be obscured by fog or poor 
lighting conditions.

Shut Down and Delay Procedures

    If a protected species observer sees a marine mammal within or 
approaching the exclusion zone prior to the start of surveying, the 
observer would notify the appropriate individual who would then be 
required to delay surveying until the marine mammal moves outside of 
the exclusion zone or if the animal has not been resighted for 60 
minutes. If a protected species observer sees a marine mammal within or 
approaching the exclusion zone during survey activities, the observer 
would notify the appropriate individual who would then be required to 
shut down surveying until the marine mammal moves outside of the 
exclusion zone or if the animal has not been resighted for 60 minutes.

Soft-start Procedures

    A ``soft-start'' technique would be used at the beginning of survey 
activities each day (or following a shut down) to allow any marine 
mammal that may be in the immediate area to leave before the sound 
sources reach full energy. Surveys shall not commence at nighttime or 
when the exclusion zone cannot be effectively monitored.
    NMFS has carefully evaluated the applicant's proposed mitigation 
measures and considered a range of other measures in the context of 
ensuring that NMFS prescribes the means of effecting the least 
practicable adverse impact on the affected marine mammal species and 
stocks and their habitat. Our evaluation of potential measures included 
consideration of the following factors in relation to one another:
     The manner in which, and the degree to which, the 
successful implementation of the measure is expected to minimize 
adverse impacts to marine mammals;
     The proven or likely efficacy of the specific measure to 
minimize adverse impacts as planned; and
     The practicability of the measure for applicant 
implementation, including consideration of personnel safety, and 
practicality of implementation.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has preliminarily 
determined that the proposed mitigation measures provide the means of 
effecting the least practicable adverse impacts on marine mammals 
species or stocks and their habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance.

Proposed Monitoring and Reporting

    In order to issue an incidental take statement for an activity, 
section 101(a)(5)(D) of the MMPA states that NMFS must set forth, where 
applicable, ``requirements pertaining to the monitoring and reporting 
of such taking.'' The MMPA implementing

[[Page 7409]]

regulations at 50 CFR 216.104(a)(13) indicate that requests for 
incidental take authorizations must include the suggested means of 
accomplishing the necessary monitoring and reporting that will result 
in increased knowledge of the species and of the level of taking or 
impacts on populations of marine mammals that are expected to be 
present in the proposed action area.

Visual Monitoring

    CWA would designate at least one biologically-trained, on-site 
individual, approved in advance by NMFS, to monitor the area for marine 
mammals 60 minutes before, during, and 60 minutes after all survey 
activities and call for shut down if any marine mammal is observed 
within or approaching the designated 500-m exclusion zone. Should a 
marine mammal not included in an incidental take authorization be 
observed at any time within the 500-m exclusion zone, shut down and 
delay procedures would be followed.
    CWA would also provide additional monitoring efforts that would 
result in increased knowledge of marine mammal species in Nantucket 
Sound. At least one NMFS-approved protected species observer would 
conduct behavioral monitoring from the survey vessel for two days for 
every 14 days of survey activity to estimate take and evaluate the 
behavioral impacts that survey activities have on marine mammals 
outside of the 500-m exclusion zone. In addition, CWA would also send 
out an additional vessel with a NMFS-approved protected species 
observer to collect data on species presence and behavior before 
surveys begin and once a month during survey activities.
    Protected species observers would be provided with the equipment 
necessary to effectively monitor for marine mammals (for example, high-
quality binoculars, compass, and range-finder) in order to determine if 
animals have entered into the harassment isopleths and to record marine 
mammal sighting information. Protected species observers must be able 
to effectively monitor the 500-m exclusion zone whenever the subbottom 
profilers are in use. Survey efforts would only take place during 
daylight hours and visibility must not be obscured by fog, lighting 
conditions, etc.
    CWA would submit a report to NMFS within 90 days of expiration of 
the IHA or completion of surveying, whichever comes first. The report 
would provide full documentation of methods, results, and 
interpretation pertaining to all monitoring. More specifically, the 
report would include the following information when a marine mammal is 
sighted:
     Dates, times, locations, heading, speed, weather, sea 
conditions (including Beaufort sea state and wind force), and 
associated activities during all survey operations and marine mammal 
sightings;
     Species, number, location, distance from the vessel, and 
behavior of any marine mammals, as well as associated survey activity 
(number of shut-downs or delays), observed throughout all monitoring 
activities;
     An estimate of the number (by species) of marine mammals 
that are known to have been exposed to the survey activity (based on 
visual observation) at received levels greater than or equal to 160 dB 
re 1 uPa (rms) and/or 180 dB re 1 uPa (rms) for cetaceans and 190 dB re 
1 uPa (rms) for pinnipeds with a discussion of any specific behaviors 
those individuals exhibited; and
     A description of the implementation and effectiveness of 
the mitigation measures of the IHA.
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA, 
such as an injury (Level A harassment), serious injury, or mortality 
(e.g., ship-strike, gear interaction, and/or entanglement), CWA would 
immediately cease the specified activities and report the incident to 
the Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, at 301-427-8401 and/or by email to 
Michael.Payne@noaa.gov and ITP.Magliocca@noaa.gov and the Northeast 
Regional Stranding Coordinator at 978-281-9300 (Mendy.Garron@noaa.gov). 
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 prohibited take. NMFS would work with CWA to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. CWA may not resume their 
activities until notified by NMFS via letter, email, or telephone.
    In the event that CWA discovers an injured or dead marine mammal, 
and the lead PSO 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 as described in the next paragraph), 
CWA would immediately report the incident to the Chief of the Permits 
and Conservation Division, Office of Protected Resources, NMFS, at 301-
427-8401 and/or by email to Michael.Payne@noaa.gov and 
ITP.Magliocca@noaa.gov and the Northeast Regional Stranding Coordinator 
at 978-281-9300 (Mendy.Garron@noaa.gov). The report must include the 
same information identified in the paragraph above. Activities may 
continue while NMFS reviews the circumstances of the incident. NMFS 
would work with CWA to determine whether modifications in the 
activities are appropriate.
    In the event that CWA discovers an injured or dead marine mammal, 
and the lead PSO 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), CWA would report the incident to 
the Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, at 301-427-8401 and/or by email to 
Michael.Payne@noaa.gov and ITP.Magliocca@noaa.gov and the Northeast 
Regional Stranding Coordinator at 978-281-9300 (Mendy.Garron@noaa.gov), 
within 24 hours of the discovery. CWA would provide photographs or 
video footage (if available) or other documentation of the stranded 
animal sighting to NMFS.

Summary of Past Monitoring and Reporting

    CWA complied with the requirements under their 2012 IHA. CWA 
completed 28 days and 459 nautical transect miles of survey activity 
during 2012 and no living marine mammals were sighted. On July 10, 
2012, a deceased harbor seal was seen by two protected species 
observers and survey equipment was immediately shut down. The observers 
determined that the seal had been deceased for 24-48 hours, based on 
signs of scavenger damage and bloating, which suggest moderate 
decomposition (Pugliares et al., 2007). Both observers

[[Page 7410]]

concurred that the animal was not injured due to survey activities; 
however, a 60-minute post watch was performed to ensure that no other 
protected species were in the vicinity. A full report was submitted to 
NMFS on July 11, 2012, within 24 hours of the initial sighting. No 
marine mammal takes were reported during the 2012 season. CWA's 
monitoring report is available online at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.

Estimated Take by Incidental Harassment

    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].
    Based on CWA's application and NMFS' subsequent analysis, the 
impact of the described survey activities may result in, at most, 
short-term modification of behavior by small numbers of marine mammals 
within the action area. Marine mammals may avoid the area or change 
their behavior at time of exposure to elevated sound levels.
    Current NMFS practice regarding exposure of marine mammals to 
anthropogenic sound is that in order to avoid the potential for injury 
of marine mammals (for example, PTS), cetaceans and pinnipeds should 
not be exposed to impulsive sounds of 180 and 190 dB re: 1 [mu]Pa or 
above, respectively. This level is considered precautionary as it is 
likely that more intense sounds would be required before injury would 
actually occur (Southall et al., 2007). Potential for behavioral 
harassment (Level B) is considered to have occurred when marine mammals 
are exposed to sounds at or above 160 dB re: 1 [mu]Pa for impulse 
sounds and 120 dB re: 1 [mu]Pa for non-pulse noise, but below the 
aforementioned thresholds. These levels are also considered 
precautionary.
    CWA estimated the number of potential takes resulting from survey 
activities by considering species density, the zone of influence, and 
duration of survey activities. More specifically, take estimates were 
calculated by multiplying the estimated species density values (n) 
measured in individuals per square kilometers, by the area of the zone 
of influence in km\2\, times the total number of survey days (d = 109). 
The zone of influence was calculated as a function of the distance a 
survey vessel with deployed boomer would travel in one survey day and 
the area around the boomer where sound levels reach or exceed 160 dB. 
For consistency with the 2011 IHA, the take estimate is based on a zone 
of influence equal to 444 m (the initial estimate for the 160 dB 
isopleth for the boomer), although based on acoustic measurements taken 
at the beginning of the 2012 survey, the 160 dB isopleth is thought to 
be much smaller. This distance was applied consistently to all marine 
mammal species.
    Estimated numbers of species potentially exposed to disturbing 
levels of sound from the boomer (the survey equipment with the largest 
160 dB isopleth) were calculated for minke whales, Atlantic white-sided 
dolphins, harbor porpoises, gray seals, and harbor seals. These 
estimates were calculated by multiplying the low and high end of the 
ranges of species density by the boomer's zone of influence and the 
number of days of survey operation. CWA calculated seal density 
estimates based on aerial survey counts for seals observed swimming 
and/or foraging in open water within the activity area. CWA included an 
adjustment factor in these density calculations for seals not seen, but 
considered present during aerial surveys. Density estimates for seals 
based on haul out counts were not used due to the distance of haul outs 
from the activity area (about 20 km to Monomoy Island and 12 km to 
Muskeget Island). Gray seals and harbor seals congregating in these 
locations are not expected to hear sounds from the survey equipment at 
160 dB or higher. The seals most likely to be exposed to potentially 
disturbing sounds are the individuals swimming and/or foraging within 
the zone of influence for the activated medium-penetration subbottom 
profiler.
    CWA is requesting incidental take based on the highest estimated 
possible species exposures to potentially disturbing levels of sound 
from the boomer. No marine mammals are expected to be exposed to 
injurious levels of sound in excess of 180 dB during survey activities. 
CWA is requesting, and NMFS is proposing, Level B harassment of 9 minke 
whales, 185 Atlantic white-sided dolphins, 110 harbor porpoises, 314 
gray seals, and 79 harbor seals. These numbers overestimate the number 
of animals likely to be taken because they are based on the highest 
density estimates and do not account for proposed mitigation measures 
(such as the 500-m exclusion zone, marine mammal monitoring, and ramp 
up procedures). These numbers indicate the maximum number of animals 
expected to occur within 444 m of the boomer. Estimated and proposed 
level of take of each species is less than one percent of each affected 
stock and therefore is considered small in relation to the stock 
estimates previously set forth.
    Negligible Impact and Small Numbers Analysis and Determination
    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.'' In making a negligible impact determination, 
NMFS considers a number of factors which include, but are not limited 
to, number of anticipated injuries or mortalities (none of which would 
be authorized here), number, nature, intensity, and duration of Level B 
harassment, and the context in which takes occur (for instance, will 
the takes occur in an area or time of significance for marine mammals, 
or are takes occurring to a small, localized population?).
    As described above, marine mammals would not be exposed to 
activities or sound levels which would result in injury (for instance, 
PTS), serious injury, or mortality. Anticipated impacts of survey 
activities on marine mammals are temporary behavioral changes due to 
avoidance of the area. All marine mammals in the vicinity of survey 
operations would be transient as no breeding, calving, pupping, or 
nursing areas, or haul-outs, overlap with the survey area. The closest 
pinniped haul-outs are about 20 km and 12 km away on Monomoy Island and 
Muskeget Island, respectively. Marine mammals approaching the survey 
area would likely be traveling or opportunistically foraging. The 
amount of take CWA requested, and NMFS proposes to authorize, is 
considered small (less than one percent) relative to the estimated 
populations of 8,987 minke whales, 23,390 Atlantic white-sided 
dolphins, 89,054 harbor porpoises, 250,000 gray seals, and 99,340 
harbor seals. Furthermore, the amount of take CWA requested and NMFS 
proposes to authorize likely overestimates the actual take that would 
occur; no marine mammal takes were observed during 28 days of survey 
activity in 2012. No affected marine mammals are listed under the ESA 
and only the Atlantic white-sided dolphin and harbor porpoise are 
considered strategic under the MMPA. Marine mammals are

[[Page 7411]]

expected to avoid the survey area, thereby reducing exposure and 
impacts. No disruption to reproductive behavior is anticipated and 
there is no anticipated effect on annual rates of recruitment or 
survival of affected marine mammals.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the mitigation and monitoring 
measures, NMFS preliminarily determines that CWA's survey activities 
would result in the incidental take of small numbers of marine mammals, 
by Level B harassment, and that the total taking would have a 
negligible impact on the affected species or stocks.

Impact on Availability of Affected Species for Taking for Subsistence 
Uses

    There are no relevant subsistence uses of marine mammals implicated 
by this action.

Endangered Species Act (ESA)

    No marine mammal species listed under the ESA are anticipated to 
occur within the action area. Therefore, section 7 consultation under 
the ESA is not required.

National Environmental Policy Act (NEPA)

    In compliance with the National Environmental Policy Act of 1969 
(42 U.S.C. 4321 et seq.), as implemented by the regulations published 
by the Council on Environmental Quality (40 CFR parts 1500-1508), and 
NOAA Administrative Order 216-6, NMFS prepared an Environmental 
Assessment (EA) to consider the direct, indirect, and cumulative 
effects to marine mammals and other applicable environmental resources 
resulting from issuance of a one-year IHA and the potential issuance of 
additional authorization for incidental harassment for the ongoing 
project in 2012. This analysis is still considered relevant for the 
proposed IHA because the applicant's proposed activity has not changed. 
This EA is available on the NMFS Web site listed in the beginning of 
this document.

    Dated: January 29, 2013.
Helen M. Golde,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2013-02195 Filed 1-31-13; 8:45 am]
BILLING CODE 3510-22-P