[Federal Register Volume 79, Number 51 (Monday, March 17, 2014)]
[Notices]
[Pages 14780-14807]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-05553]
[[Page 14779]]
Vol. 79
Monday,
No. 51
March 17, 2014
Part II
Department of Commerce
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National Oceanic and Atmospheric Administration
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Takes of Marine Mammals Incidental to Specified Activities; Marine
Geophysical Survey in the Northwest Atlantic Ocean Offshore New Jersey,
May to August 2014; Notice
Federal Register / Vol. 79 , No. 51 / Monday, March 17, 2014 /
Notices
[[Page 14780]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XD141
Takes of Marine Mammals Incidental to Specified Activities;
Marine Geophysical Survey in the Northwest Atlantic Ocean Offshore New
Jersey, May to August 2014
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 the Lamont Doherty Earth
Observatory (Observatory) in collaboration with the National Science
Foundation (Foundation), for an Incidental Harassment Authorization
(Authorization) to take marine mammals, by harassment incidental to
conducting a marine geophysical (seismic) survey in the northwest
Atlantic Ocean off the New Jersey coast June through July, 2014. The
proposed dates for this action would be May 29, 2014 through August 17,
2014 to account for minor deviations due to logistics and weather. Per
the Marine Mammal Protection Act, we are requesting comments on our
proposal to issue an Authorization to the Observatory to incidentally
take, by Level B harassment only, 26 species of marine mammals during
the specified activity.
DATES: NMFS must receive comments and information on or before April
16, 2014.
ADDRESSES: Address comments on the application to Jolie Harrison,
Supervisor, Incidental Take Program, Permits and Conservation Division,
Office of Protected Resources, National Marine Fisheries Service, 1315
East-West Highway, Silver Spring, MD 20910. The mailbox address for
providing email comments is [email protected]. Please include 0648-
XD141 in the subject line. Comments sent via email to
[email protected], including all attachments, must not exceed a 25-
megabyte file size. NMFS is not responsible for email comments sent to
addresses other than the one provided here.
Instructions: All submitted comments are a part of the public
record and NMFS will post them to http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications 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.
To obtain an electronic copy of the application containing a list
of the references used in this document, write to the previously
mentioned address, telephone the contact listed here (see FOR FURTHER
INFORMATION CONTACT), or visit the internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
The Foundation has prepared a draft Environmental Assessment (EA)
in accordance with the National Environmental Policy Act (NEPA) and the
regulations published by the Council on Environmental Quality. The EA
titled ``Draft Environmental Assessment of a Marine Geophysical Survey
by the R/V Marcus G. Langseth in the Atlantic Ocean off New Jersey,
June-July 2014,'' prepared by LGL, Ltd. environmental research
associates, on behalf of the Foundation and the Observatory is
available at the same internet address. Information in the
Observatory's application, the Foundation's EA, and this notice
collectively provide the environmental information related to proposed
issuance of the Authorization for public review and comment.
FOR FURTHER INFORMATION CONTACT: Jeannine Cody, NMFS, Office of
Protected Resources, NMFS (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Background
Section 101(a)(5)(D) of the Marine Mammal Protection Act of 1972,
as amended (MMPA; 16 U.S.C. 1361 et seq.) directs the Secretary of
Commerce to allow, upon request, the incidental, but not intentional,
taking of small numbers of marine mammals of a species or population
stock, by U.S. citizens who engage in a specified activity (other than
commercial fishing) within a specified geographical region if, after
NMFS provides a notice of a proposed authorization to the public for
review and comment: (1) NMFS makes certain findings; and (2) the taking
is limited to harassment.
An Authorization shall be granted for the incidental taking of
small numbers of marine mammals if NMFS finds that the taking will have
a negligible impact on the species or stock(s), and will not have an
unmitigable adverse impact on the availability of the species or
stock(s) for subsistence uses (where relevant). The Authorization must
also set forth the permissible methods of taking; other means of
effecting the least practicable adverse impact on the species or stock
and its habitat; and requirements pertaining to the mitigation,
monitoring and reporting of such taking. 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.''
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 17, 2013, NMFS received an application from the
Observatory requesting that we issue an Authorization for the take of
marine mammals, incidental to conducting a seismic survey in the
northwest Atlantic Ocean June through July, 2014. NMFS determined the
application complete and adequate on February 3, 2014.
The Observatory proposes to conduct a high-energy, 3-dimensional
(3-D) seismic survey on the R/V Langseth in the northwest Atlantic
Ocean approximately 25 to 85 kilometers (km) (15.5 to 52.8 miles (mi))
off the New Jersey coast for approximately 32 days from June 3 to July
9, 2014. The following specific aspect of the proposed activity has the
potential to take marine mammals: increased underwater sound generated
during the operation of the seismic airgun arrays. Thus, we anticipate
that take, by Level B harassment only, of 26 species of marine mammals
could result from the specified activity.
Description of the Specified Activity
Overview
The Observatory plans to use one source vessel, the R/V Marcus G.
Langseth (Langseth), two pairs of seismic airgun subarrays configured
with four or eight airguns as the energy source and four hydrophone
streamers to conduct the conventional seismic survey. In addition to
the operations of the airguns, the Observatory intends to
[[Page 14781]]
operate a multibeam echosounder, a sub-bottom profiler, and acoustic
Doppler current profiler on the Langseth continuously throughout the
proposed survey.
The purpose of the survey is to collect and analyze data on the
arrangement of sediments deposited during times of changing global sea
level from roughly 60 million years ago to present. The 3-D survey
would investigate features such as river valleys cut into coastal plain
sediments now buried under a kilometer of younger sediment and flooded
by today's ocean.
Dates and Duration
The Observatory proposes to conduct the seismic survey from the
period of June 3 through July 9, 2014. The proposed study (e.g.,
equipment testing, startup, line changes, repeat coverage of any areas,
and equipment recovery) would include approximately 720 hours of airgun
operations (i.e., 30 days over 24 hours). Some minor deviation from the
Observatory's requested dates of June through August, 2014, is
possible, depending on logistics, weather conditions, and the need to
repeat some lines if data quality is substandard. Thus, the proposed
Authorization, if issued, would be effective from May 29, 2014 through
August 17, 2014.
We refer the reader to the Detailed Description of Activities
section later in this notice for more information on the scope of the
proposed activities.
Specified Geographic Region
The Observatory proposes to conduct the seismic survey in the
Atlantic Ocean, approximately 25 to 85 km (15.5 to 52.8 mi) off the
coast of New Jersey between approximately 39.3-39.7[deg] N and
approximately 73.2-73.8[deg] W (see Figure 1). Water depths in the
survey area are approximately 30 to 75 m (98.4 to 246 feet (ft)). They
would conduct the proposed survey outside of New Jersey state waters
and within the U.S. Exclusive Economic Zone.
[GRAPHIC] [TIFF OMITTED] TN17MR14.000
Detailed Description of Activities
Transit Activities
The Langseth would depart from Newark, NJ, on June 3, 2014, and
transit for eight hours to the proposed survey area. Setup, deployment,
and streamer ballasting would occur over approximately three days. At
the conclusion of the 30-day survey, the Langseth would take
approximately one day to retrieve gear. At the conclusion of the
proposed survey activities, the Langseth would return to Newark, NJ on
July 9, 2014.
Vessel Specifications
The survey would involve one source vessel, the R/V Langseth and
one chase vessel. The Langseth, owned by the Foundation and operated by
the Observatory, is a seismic research vessel with a quiet propulsion
system that avoids interference with the seismic signals emanating from
the airgun array. The vessel is 71.5 m (235 ft) long; has a beam of
17.0 m (56 ft); a maximum draft of 5.9 m (19 ft); and a gross tonnage
of 3,834 pounds. It has two 3,550 horsepower (hp) Bergen BRG-6 diesel
engines which drive two propellers. Each propeller has four blades and
the shaft typically rotates at 750 revolutions per minute. The vessel
also has an 800-hp bowthruster, which is off during seismic
acquisition.
The vessel's speed during seismic operations would be approximately
4.5 knots (kt) (8.3 km/hour (hr); 5.1 miles per hour (mph)). The
vessel's cruising speed outside of seismic operations is approximately
10 kt (18.5 km/hr; 11.5 mph). While the Langseth tows the airgun array
and the hydrophone streamer, its turning rate is limited to
[[Page 14782]]
five degrees per minute. Thus, the Langseth's maneuverability is
limited during operations while it tows the streamer.
The vessel also has an observation tower from which protected
species visual observers (observer) will watch for marine mammals
before and during the proposed seismic acquisition operations. When
stationed on the observation platform, the observer's eye level will be
approximately 21.5 m (71 ft) above sea level providing the observer an
unobstructed view around the entire vessel.
The chase vessel would be a multi-purpose offshore utility vessel
similar to the Northstar Commander, which is 28 m (91.9 ft) long with a
beam of 8 m (26.2 ft) and a draft of 2.6 m (8.5 ft). The chase vessel
has twin 450-hp screws (Volvo D125-E).
Data Acquisition Activities
The proposed survey would cover approximately 4,900 km (3,045 mi)
of transect lines within a 12 by 50 km (7.5 by 31 mi) area. Each
transect line would have a spacing interval of 150 m (492 ft) in two 6-
m (19.7-ft) wide race-track patterns.
During the survey, the Langseth would deploy two pairs of subarrays
of four or eight airguns as an energy source. The subarrays would fire
alternately, with a total volume of either approximately 700 cubic
inches (in\3\) or 1,400 in\3\. The receiving system would consist of
four 3,000-m (1.9-mi) hydrophone streamers with a spacing interval of
75 m (246 ft) between each streamer. As the Langseth tows the airgun
subarrays along the survey lines, the hydrophone streamers would
receive the returning acoustic signals and transfer the data to the on-
board processing system.
Seismic Airguns
The airguns are a mixture of Bolt 1500LL and Bolt 1900LLX airguns
ranging in size from 40 to 220 in\3\, with a firing pressure of 1,950
pounds per square inch. The dominant frequency components range from
zero to 188 Hertz (Hz).
During the survey, the Observatory plans to use either a subarray
with four airguns in one string or a subarray with a total of eight
airguns in two strings on the vessel's port (left) side. The vessel's
starboard (right) side would have an identical subarray configuration
of either four airguns in one string or eight airguns in two strings to
form the second source. The Langseth would operate the port and
starboard sources in a ``flip-flop'' mode, firing alternately as it
progresses along the track. In this configuration, the source volume
would not exceed 700 in\3\ (i.e., the four-string subarray) or 1,400
in\3\ (i.e., the eight-string subarray) at any time during acquisition
(see Figure A1, page 57 in the Foundation's 2014 EA). The Langseth
would tow each subarray at a depth of either 4.5 or 6 m (14.8 or 19.7
ft) resulting in a shot interval of approximately 5.4 seconds (12.5 m;
41 ft). During acquisition the airguns will emit a brief (approximately
0.1 s) pulse of sound. During the intervening periods of operations,
the airguns are silent.
Airguns function by venting high-pressure air into the water which
creates an air bubble. The pressure signature of an individual airgun
consists of a sharp rise and then fall in pressure, followed by several
positive and negative pressure excursions caused by the oscillation of
the resulting air bubble. The oscillation of the air bubble transmits
sounds downward through the seafloor and there is also a reduction in
the amount of sound transmitted in the near horizontal direction.
However, the airgun array also emits sounds that travel horizontally
toward non-target areas.
The nominal source levels of the airgun subarrays on the Langseth
range from 246 to 253 decibels (dB) re: 1 [mu]Pa
(peak to peak). (We express sound pressure level as the
ratio of a measured sound pressure and a reference pressure level. The
commonly used unit for sound pressure is dB and the commonly used
reference pressure level in underwater acoustics is 1 microPascal
([mu]Pa)). Briefly, the effective source levels for horizontal
propagation are lower than source levels for downward propagation. We
refer the reader to the Observatory's Authorization application and the
Foundation's EA for additional information on downward and horizontal
sound propagation related to the airgun's source levels.
Additional Acoustic Data Acquisition Systems
Multibeam Echosounder: The Langseth will operate a Kongsberg EM 122
multibeam echosounder concurrently during airgun operations to map
characteristics of the ocean floor. The hull-mounted echosounder emits
brief pulses of sound (also called a ping) (10.5 to 13.0 kHz) in a fan-
shaped beam that extends downward and to the sides of the ship. The
transmitting beamwidth is 1 or 2[deg] fore-aft and 150[deg] athwartship
and the maximum source level is 242 dB re: 1 [mu]Pa.
Each ping consists of eight (in water greater than 1,000 m; 3,280
ft) or four (in water less than 1,000 m; 3,280 ft) successive, fan-
shaped transmissions, from two to 15 milliseconds (ms) in duration and
each ensonifying a sector that extends 1[deg] fore-aft. Continuous wave
pulses increase from 2 to 15 ms long in water depths up to 2,600 m
(8,530 ft). The echosounder uses frequency-modulated chirp pulses up to
100-ms long in water greater than 2,600 m (8,530 ft). The successive
transmissions span an overall cross-track angular extent of about
150[deg], with 2-ms gaps between the pulses for successive sectors.
Sub-bottom Profiler: The Langseth will also operate a Knudsen Chirp
3260 sub-bottom profiler concurrently during airgun and echosounder
operations to provide information about the sedimentary features and
bottom topography. The profiler is capable of reaching depths of 10,000
m (6.2 mi). The dominant frequency component is 3.5 kHz and a hull-
mounted transducer on the vessel directs the beam downward in a 27[deg]
cone. The power output is 10 kilowatts (kW), but the actual maximum
radiated power is three kilowatts or 222 dB re: 1 [mu]Pa. The ping
duration is up to 64 ms with a pulse interval of one second, but a
common mode of operation is to broadcast five pulses at 1-s intervals
followed by a 5-s pause.
Acoustic Doppler Current Profiler: The Observatory would measure
currents using a Teledyne OS75 75-kilohertz (kHz) Acoustic Doppler
current profiler (ADCP). The ADCP's configuration consists of a 4-beam
phased array with a beam angle of 30[deg]. The source level is
proprietary information but has a maximum acoustic source level of 224
dB.
Description of Marine Mammals in the Area of the Specified Activity
Table 1 in this notice provides the following: All marine mammal
species with possible or confirmed occurrence in the proposed activity
area; information on those species' regulatory status under the MMPA
and the Endangered Species Act of 1973 (16 U.S.C. 1531 et seq.);
abundance; occurrence and seasonality in the activity area.
The Observatory presented species information in Table 2 of their
application but excluded information on pinnipeds because they
anticipated that these species would have a more northerly distribution
during the summer and thus have a low likelihood of occurring in the
survey area. Based on the best available information, NMFS expects that
certain pinniped species have the potential to occur within the survey
area and have included
[[Page 14783]]
additional information for these species in Table 1 of this notice.
Table 1--General Information on Marine Mammals That Could Potentially Occur in the Proposed Activity Area in May Through August, 2014
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Stock/ species
Species Stock name Regulatory status 1 2 abundance \3\ Occurrence and range Season
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North Atlantic right whale Western Atlantic...... MMPA-D ESA-EN......... 444.................. common coastal/shelf. year-round.\4\
(Eubalaena glacialis).
Humpback whale (Megaptera Gulf of Maine......... MMPA-D ESA-EN......... 823.................. common coastal....... spring-fall.
novaeangliae).
Common minke whale (Balaenoptera Canadian East Coast... MMPA-D ESA-NL......... 20,741............... rare coastal/shelf... spring-summer.
acutorostrata).
Sei whale (Balaenoptera borealis).. Nova Scotia........... MMPA-D ESA-EN......... 357.................. uncommon shelf edge.. spring.
Fin whale (Balaenoptera physalus).. Western North Atlantic MMPA-D ESA-EN......... 3,522................ common pelagic....... year-round.
Blue whale (Balaenoptera musculus). Western North Atlantic MMPA-D ESA-EN......... 440.................. uncommon coastal/ occasional.
pelagic.
Sperm whale (Physeter Nova Scotia........... MMPA-D ESA-EN......... 1,593................ common pelagic....... year-round.
macrocephalus).
Dwarf sperm whale (Kogia sima)..... Western North Atlantic MMPA-NC ESA-NL........ 1,042................ uncommon shelf....... year-round.
Pygmy sperm whale (K. breviceps)... Western North Atlantic MMPA-NC ESA-NL........ 741.................. uncommon shelf....... year-round.
Blainville's beaked whale Western North Atlantic MMPA-NC ESA-NL........ 7,948 \5\............ uncommon shelf/ spring-summer.
(Mesoplodon densirostris). pelagic.
Cuvier's beaked whale (Ziphius Western North Atlantic MMPA-NC ESA-NL........ 4,962................ uncommon shelf/ spring-summer.
cavirostris). pelagic.
Gervais' beaked whale (M. Western North Atlantic MMPA-NC ESA-NL........ 1,847................ uncommon shelf/ spring-summer.
europaeus). pelagic.
Sowerby's beaked whale (M. bidens). Western North Atlantic MMPA-NC ESA-NL........ 3,653................ uncommon shelf/ spring-summer.
pelagic.
True's beaked whale (M. mirus)..... Western North Atlantic MMPA-NC ESA-NL........ 7,948 \5\............ uncommon shelf/ spring-summer.
pelagic.
Northern bottlenose whale Western North Atlantic MMPA-NC ESA-NL........ unknown.............. rare pelagic......... unknown.
(Hyperoodon ampullatus).
Rough-toothed dolphin (Steno Western North Atlantic MMPA-NC ESA-NL........ 274.................. rare pelagic......... summer.
bredanensis).
Bottlenose dolphin (Tursiops Western North Atlantic MMPA-NC ESA-NL........ 81,588............... common pelagic....... spring-summer.
truncates). Offshore.
Western North Atlantic MMPA-D ESA-NL......... 9,604................ common coastal....... summer.
Northern Migratory
Coastal.
Pantropical spotted dolphin Western North Atlantic MMPA-NC ESA-NL........ 4,439................ rare pelagic......... summer-fall.
(Stenella attenuate).
Atlantic spotted dolphin (S. Western North Atlantic MMPA-NC ESA-NL........ 26,798............... common coastal....... summer-fall.
frontalis).
Spinner dolphin (S. longirostris).. Western North Atlantic MMPA-NC ESA-NL........ unknown.............. rare pelagic......... unknown.
Striped dolphin (S. coeruleoalba).. Western North Atlantic MMPA-NC ESA-NL........ 46,882............... uncommon shelf....... summer.
Short-beaked common dolphin Western North Atlantic MMPA-NC ESA-NL........ 67,191............... common shelf/pelagic. summer-fall.
(Delphinus delphis).
White-beaked dolphin Western North Atlantic MMPA-NC ESA-NL........ 2,003................ rare coastal/shelf... summer.
(Lagenorhynchus albirostris).
Atlantic white-sided-dolphin (L. Western North Atlantic MMPA-NC ESA-NL........ 48,819............... uncommon shelf/slope. summer-winter.
acutus).
Risso's dolphin (Grampus griseus).. Western North Atlantic MMPA-NC ESA-NL........ 15,197............... common shelf/slope... year-round.
False killer whale (Pseudorca Northern Gulf of MMPA-NC ESA-NL........ 777.................. rare pelagic......... spring-summer.
crassidens). Mexico.
Pygmy killer whale (Feresa Western North Atlantic MMPA-NC ESA-NL........ unknown.............. rare pelagic......... unknown.
attenuate).
Killer whale (Orcinus orca)........ Western North Atlantic MMPA-NC ESA-NL........ unknown.............. rare pelagic......... unknown.
Long-finned pilot whale Western North Atlantic MMPA-NC ESA-NL........ 12,619............... uncommon shelf/ summer.
(Globicephala melas). pelagic.
Short-finned pilot whale (G. Western North Atlantic MMPA-NC ESA-NL........ 24,674............... uncommon shelf/ summer.
macrorhynchus). pelagic.
[[Page 14784]]
Harbor porpoise (Phocoena phocoena) Gulf of Maine/Bay of MMPA-NC ESA-NL........ 79,833............... common coastal....... year-round.
Fundy.
Gray seal (Halichoerus grypus)..... Western North Atlantic MMPA-NC ESA-NL........ 348,999 \6\.......... common coastal....... fall-spring.
Harbor seal (Phoca vitulina)....... Western North Atlantic MMPA-NC ESA-NL........ 99,340 \7\........... common coastal....... fall-spring.
Harp seal (Pagophilus Western North Atlantic MMPA-NC ESA-NL........ 8,600,000............ rare pack ice........ Jan-May.
groenlandicus).
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\1\ MMPA: D = Depleted, S = Strategic, NC = Not Classified.
\2\ ESA: EN = Endangered, T = Threatened, DL = Delisted, NL = Not listed.
\3\ 2012 NMFS Stock Assessment Report (Waring et al., 2013) unless otherwise noted.
\4\ Seasonality based on Whitt et al., 2013.
\5\ Undifferentiated beaked whales abundance estimate (Waring et al., 2013).
\6\ Canadian population estimate (Waring et al., 2013).
\7\ 2001 survey estimate (Waring et al., 2013).
NMFS refers the public to the Observatory's application, the
Foundation's EA (see ADDRESSES), and the 2012 NMFS Marine Mammal Stock
Assessment Report available online at: http://www.nmfs.noaa.gov/pr/sars/species.htm for further information on the biology and local
distribution of these species.
Potential Effects of the Specified Activities on Marine Mammals
This section includes a summary and discussion of the ways that the
types of stressors associated with the specified activity (e.g.,
seismic airgun operations, vessel movement) impact marine mammals (via
observations or scientific studies). This section may include a
discussion of known effects that do not rise to the level of an MMPA
take (for example, with acoustics, we may include a discussion of
studies of animals exhibiting no reaction to sound or exhibiting barely
perceptible avoidance behaviors). This discussion may also include
reactions that NMFS considers to rise to the level of a take.
NMFS intends to provide a background of potential effects of the
Observatory's activities in this section. This section does not
consider the specific manner in which the Observatory would carry out
the proposed activity, what mitigation measures the Observatory would
implement, and how either of those would shape the anticipated impacts
from this specific activity. The ``Estimated Take by Incidental
Harassment'' section later in this document will include a quantitative
analysis of the number of individuals that we expect the Observatory to
take during this activity. The ``Negligible Impact Analysis'' section
will include the analysis of how this specific activity would impact
marine mammals. NMFS will consider the content of the following
sections: (1) Estimated Take by Incidental Harassment; (3) Proposed
Mitigation; and (4) Anticipated Effects on Marine Mammal Habitat, to
draw conclusions regarding the likely impacts of this activity on the
reproductive success or survivorship of individuals--and from that
consideration--the likely impacts of this activity on the affected
marine mammal populations or stocks.
Acoustic Impacts
When considering the influence of various kinds of sound on the
marine environment, it is necessary to understand that different kinds
of marine life are sensitive to different frequencies of sound. Current
data indicate that not all marine mammal species have equal hearing
capabilities (Richardson et al., 1995; Southall et al., 1997; Wartzok
and Ketten, 1999; Au and Hastings, 2008).
Southall et al. (2007) designated ``functional hearing groups'' for
marine mammals based on available behavioral data; audiograms derived
from auditory evoked potentials; anatomical modeling; and other data.
Southall et al. (2007) also estimated the lower and upper frequencies
of functional hearing for each group. However, animals are less
sensitive to sounds at the outer edges of their functional hearing
range and are more sensitive to a range of frequencies within the
middle of their functional hearing range.
The functional groups applicable to this proposed survey and the
associated frequencies are:
Low frequency cetaceans (13 species of mysticetes):
Functional hearing estimates occur between approximately 7 Hertz (Hz)
and 30 kHz (extended from 22 kHz based on data indicating that some
mysticetes can hear above 22 kHz; Au et al., 2006; Lucifredi and Stein,
2007; Ketten and Mountain, 2009; Tubelli et al., 2012);
Mid-frequency cetaceans (32 species of dolphins, six
species of larger toothed whales, and 19 species of beaked and
bottlenose whales): Functional hearing estimates occur between
approximately 150 Hz and 160 kHz;
High-frequency cetaceans (eight species of true porpoises,
six species of river dolphins, Kogia, the franciscana, and four species
of cephalorhynchids): Functional hearing estimates occur between
approximately 200 Hz and 180 kHz; and
Pinnipeds in water: Phocid (true seals) functional hearing
estimates occur between approximately 75 Hz and 100 kHz (Hemila et al.,
2006; Mulsow et al., 2011; Reichmuth et al., 2013) and otariid (seals
and sea lions) functional hearing estimates occur between approximately
100 Hz to 40 kHz.
As mentioned previously in this document, 26 marine mammal species
(6 mysticetes, 17 odontocetes, and 3 pinnipeds) would likely occur in
the proposed action area. Table 2 presents the classification of these
26 species into their respective functional hearing group. We consider
a species' functional hearing group when we analyze the effects of
exposure to sound on marine mammals.
[[Page 14785]]
Table 2--Classification of Marine Mammals That Could Potentially Occur
in the Proposed Activity Area in May Through August, 2014 by Functional
Hearing Group
[Southall et. al., 2007]
------------------------------------------------------------------------
------------------------------------------------------------------------
Low Frequency Hearing Range............ North Atlantic right, humpback,
common minke, sei, fin, and
blue whale
Mid-Frequency Hearing Range............ Sperm whale, Blainville's
beaked whale, Cuvier's beaked
whale, Gervais' beaked whale,
Sowerby's beaked whale, True's
beaked whale, northern
bottlenose whale, false killer
whale, pygmy killer whale,
killer whale, rough-toothed
dolphin, bottlenose dolphin,
pantropical spotted dolphin,
Atlantic spotted dolphin,
spinner dolphin, striped
dolphin, short-beaked common
dolphin, white-beaked dolphin,
Atlantic white-sided-dolphin,
Risso's dolphin, long-finned
pilot whale, short-finned
pilot whale
High Frequency Hearing Range........... Dwarf sperm whale, pygmy sperm
whale, harbor porpoise
Pinnipeds in Water Hearing Range....... Gray seal, harbor seal, harp
seal
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1. Potential Effects of Airgun Sounds on Marine Mammals
The effects of sounds from airgun operations might include one or
more of the following: Tolerance, masking of natural sounds, behavioral
disturbance, temporary or permanent impairment, or non-auditory
physical or physiological effects (Richardson et al., 1995; Gordon et
al., 2003; Nowacek et al., 2007; Southall et al., 2007). As outlined in
previous NMFS documents, the effects of noise on marine mammals are
highly variable, often depending on species and contextual factors
(based on Richardson et al., 1995).
Tolerance
Studies on marine mammals' tolerance to sound in the natural
environment are relatively rare. Richardson et al. (1995) defined
tolerance as the occurrence of marine mammals in areas where they are
exposed to human activities or manmade noise. In many cases, tolerance
develops by the animal habituating to the stimulus (i.e., the gradual
waning of responses to a repeated or ongoing stimulus) (Richardson, et
al., 1995), but because of ecological or physiological requirements,
many marine animals may need to remain in areas where they are exposed
to chronic stimuli (Richardson, et al., 1995).
Numerous studies have shown that pulsed sounds from airguns are
often readily detectable in the water at distances of many kilometers.
Several studies have also shown that marine mammals at distances of
more than a few kilometers from operating seismic vessels often show no
apparent response. That is often true even in cases when the pulsed
sounds must be readily audible to the animals based on measured
received levels and the hearing sensitivity of the marine mammal group.
Although various baleen whales and toothed whales, and (less
frequently) pinnipeds have been shown to react behaviorally to airgun
pulses under some conditions, at other times marine mammals of all
three types have shown no overt reactions (Stone, 2003; Stone and
Tasker, 2006; Moulton et al. 2005, 2006) and (MacLean and Koski, 2005;
Bain and Williams, 2006 for Dall's porpoises).
Weir (2008) observed marine mammal responses to seismic pulses from
a 24 airgun array firing a total volume of either 5,085 in\3\ or 3,147
in\3\ in Angolan waters between August 2004 and May 2005. Weir (2008)
recorded a total of 207 sightings of humpback whales (n = 66), sperm
whales (n = 124), and Atlantic spotted dolphins (n = 17) and reported
that there were no significant differences in encounter rates
(sightings/hour) for humpback and sperm whales according to the airgun
array's operational status (i.e., active versus silent).
Masking
The term masking refers to the inability of a subject to recognize
the occurrence of an acoustic stimulus as a result of the interference
of another acoustic stimulus (Clark et al., 2009). Masking, or auditory
interference, generally occurs when sounds in the environment are
louder than, and of a similar frequency as, auditory signals an animal
is trying to receive. Masking is a phenomenon that affects animals that
are trying to receive acoustic information about their environment,
including sounds from other members of their species, predators, prey,
and sounds that allow them to orient in their environment. Masking
these acoustic signals can disturb the behavior of individual animals,
groups of animals, or entire populations.
Marine mammals use acoustic signals for a variety of purposes,
which differ among species, but include communication between
individuals, navigation, foraging, reproduction, avoiding predators,
and learning about their environment (Erbe and Farmer, 2000; Tyack,
2000). Introduced underwater sound may, through masking, reduce the
effective communication distance of a marine mammal species if the
frequency of the source is close to that used as a signal by the marine
mammal, and if the anthropogenic sound is present for a significant
fraction of the time (Richardson et al., 1995).
For the airgun sound generated from the proposed seismic survey,
sound will consist of low frequency (under 500 Hz) pulses with
extremely short durations (less than one second). Lower frequency man-
made sounds are more likely to affect detection of communication calls
and other potentially important natural sounds such as surf and prey
noise. Generally, the asking effects of the intermittent seismic pulses
near the sound source should be minor due to the brief duration of
these pulses and relatively long silent periods between air gun shots
(approximately 12 seconds). However, at longer distances (over tens of
kilometers away), due to multipath propagation and reverberation, the
durations of airgun pulses can be ``stretched'' to seconds with long
decays (Madsen et al., 2006), although the intensity of the sound is
greatly reduced.
We expect that the masking effects of pulsed sounds (even from
large arrays of airguns) on marine mammal calls and other natural
sounds will be limited, although there are very few specific data on
this. Because of the intermittent nature and low duty cycle of seismic
airgun pulses, animals can emit and receive sounds in the relatively
quiet intervals between pulses. However, in some situations,
reverberation occurs for much or the entire interval between pulses
(e.g., Simard et al., 2005; Clark and Gagnon, 2006) which could mask
calls. NMFS understands that some baleen and toothed whales continue
calling in the presence of seismic pulses, and that some researchers
have heard these calls between the seismic pulses (e.g., Richardson et
al., 1986; McDonald et al., 1995; Greene et al., 1999; Nieukirk et al.,
2004; Smultea et al., 2004; Holst et al., 2005a, 2005b, 2006; and Dunn
and Hernandez, 2009). However, Clark and Gagnon (2006) reported that
fin whales in the northeast Pacific Ocean went silent for an extended
period starting soon after the onset of a seismic survey in the area.
[[Page 14786]]
Similarly, there has been one report that sperm whales ceased calling
when exposed to pulses from a very distant seismic ship (Bowles et al.,
1994). However, more recent studies have found that they continued
calling in the presence of seismic pulses (Madsen et al., 2002; Tyack
et al., 2003; Smultea et al., 2004; Holst et al., 2006; and Jochens et
al., 2008). Several studies have reported hearing dolphins and
porpoises calling while airguns were operating (e.g., Gordon et al.,
2004; Smultea et al., 2004; Holst et al., 2005a, b; and Potter et al.,
2007). The sounds important to small odontocetes are predominantly at
much higher frequencies than are the dominant components of airgun
sounds, thus limiting the potential for masking.
Marine mammals are thought to be able to compensate for masking by
adjusting their acoustic behavior through shifting call frequencies,
increasing call volume, and increasing vocalization rates. For example
in one study, blue whales increased call rates when exposed to noise
from seismic surveys in the St. Lawrence Estuary (Di Iorio and Clark,
2010). The North Atlantic right whales exposed to high shipping noise
increased call frequency (Parks et al., 2007), while some humpback
whales respond to low-frequency active sonar playbacks by increasing
song length (Miller et al., 2000).
Additionally, beluga whales change their vocalizations in the
presence of high background noise possibly to avoid masking calls (Au
et al., 1985; Lesage et al., 1999; Scheifele et al., 2005). Although
some degree of masking is inevitable when high levels of manmade
broadband sounds are present in the sea, marine mammals have evolved
systems and behavior that function to reduce the impacts of masking.
Structured signals, such as the echolocation click sequences of small
toothed whales, may be readily detected even in the presence of strong
background noise because their frequency content and temporal features
usually differ strongly from those of the background noise (Au and
Moore, 1988, 1990). The components of background noise that are similar
in frequency to the sound signal in question primarily determine the
degree of masking of that signal.
Redundancy and context can also facilitate detection of weak
signals. These phenomena may help marine mammals detect weak sounds in
the presence of natural or manmade noise. Most masking studies in
marine mammals present the test signal and the masking noise from the
same direction. The sound localization abilities of marine mammals
suggest that, if signal and noise come from different directions,
masking would not be as severe as the usual types of masking studies
might suggest (Richardson et al., 1995). The dominant background noise
may be highly directional if it comes from a particular anthropogenic
source such as a ship or industrial site. Directional hearing may
significantly reduce the masking effects of these sounds by improving
the effective signal-to-noise ratio. In the cases of higher frequency
hearing by the bottlenose dolphin, beluga whale, and killer whale,
empirical evidence confirms that masking depends strongly on the
relative directions of arrival of sound signals and the masking noise
(Penner et al., 1986; Dubrovskiy, 1990; Bain et al., 1993; Bain and
Dahlheim, 1994).
Toothed whales and probably other marine mammals as well, have
additional capabilities besides directional hearing that can facilitate
detection of sounds in the presence of background noise. There is
evidence that some toothed whales can shift the dominant frequencies of
their echolocation signals from a frequency range with a lot of ambient
noise toward frequencies with less noise (Au et al., 1974, 1985; Moore
and Pawloski, 1990; Thomas and Turl, 1990; Romanenko and Kitain, 1992;
Lesage et al., 1999). A few marine mammal species increase the source
levels or alter the frequency of their calls in the presence of
elevated sound levels (Dahlheim, 1987; Au, 1993; Lesage et al., 1993,
1999; Terhune, 1999; Foote et al., 2004; Parks et al., 2007, 2009; Di
Iorio and Clark, 2010; Holt et al., 2009).
These data demonstrating adaptations for reduced masking pertain
mainly to the very high frequency echolocation signals of toothed
whales. There is less information about the existence of corresponding
mechanisms at moderate or low frequencies or in other types of marine
mammals. For example, Zaitseva et al. (1980) found that, for the
bottlenose dolphin, the angular separation between a sound source and a
masking noise source had little effect on the degree of masking when
the sound frequency was 18 kHz, in contrast to the pronounced effect at
higher frequencies. Studies have noted directional hearing at
frequencies as low as 0.5-2 kHz in several marine mammals, including
killer whales (Richardson et al., 1995a). This ability may be useful in
reducing masking at these frequencies. In summary, high levels of sound
generated by anthropogenic activities may act to mask the detection of
weaker biologically important sounds by some marine mammals. This
masking may be more prominent for lower frequencies. For higher
frequencies, such as that used in echolocation by toothed whales,
several mechanisms are available that may allow them to reduce the
effects of such masking.
Behavioral Disturbance
Marine mammals may behaviorally react to sound when exposed to
anthropogenic noise. Disturbance includes a variety of effects,
including subtle to conspicuous changes in behavior, movement, and
displacement. Reactions to sound, if any, depend on species, state of
maturity, experience, current activity, reproductive state, time of
day, and many other factors (Richardson et al., 1995; Wartzok et al.,
2004; Southall et al., 2007; Weilgart, 2007). These behavioral
reactions are often shown as: Changing durations of surfacing and
dives, number of blows per surfacing, or moving direction and/or speed;
reduced/increased vocal activities; changing/cessation of certain
behavioral activities (such as socializing or feeding); visible startle
response or aggressive behavior (such as tail/fluke slapping or jaw
clapping); avoidance of areas where noise sources are located; and/or
flight responses (e.g., pinnipeds flushing into the water from haul-
outs or rookeries). 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).
The biological significance of many of these behavioral
disturbances is difficult to predict, especially if the detected
disturbances appear minor. However, one could expect the consequences
of behavioral modification to be biologically significant if the change
affects growth, survival, and/or reproduction. Some of these
significant behavioral modifications include:
Change in diving/surfacing patterns (such as those thought
to be causing beaked whale stranding due to exposure to military mid-
frequency tactical sonar);
Habitat abandonment due to loss of desirable acoustic
environment; and
Cessation of feeding or social interaction.
[[Page 14787]]
The onset of behavioral disturbance from anthropogenic noise
depends on both external factors (characteristics of noise sources and
their paths) and the receiving animals (hearing, motivation,
experience, demography) and is also difficult to predict (Richardson et
al., 1995; Southall et al., 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 industrial activities and/or
exposed to a particular level of industrial sound. In most cases, this
approach likely overestimates the numbers of marine mammals that could
potentially be affected in some biologically-important manner.
The sound criteria used to estimate how many marine mammals might
be disturbed to some biologically-important degree by a seismic program
are based primarily on behavioral observations of a few species.
Scientists have conducted detailed studies on humpback, gray, bowhead
(Balaena mysticetus), and sperm whales. There are less detailed data
available for some other species of baleen whales and small toothed
whales, but for many species there are no data on responses to marine
seismic surveys.
Baleen Whales--Baleen whales generally tend to avoid operating
airguns, but avoidance radii are quite variable (reviewed in Richardson
et al., 1995). Whales are often reported to show no overt reactions to
pulses from large arrays of airguns at distances beyond a few
kilometers, even though the airgun pulses remain well above ambient
noise levels out to much longer distances. However, baleen whales
exposed to strong noise pulses from airguns often react by deviating
from their normal migration route and/or interrupting their feeding and
moving away from the area. In the cases of migrating gray and bowhead
whales, the observed changes in behavior appeared to be of little or no
biological consequence to the animals (Richardson et al., 1995). They
avoided the sound source by displacing their migration route to varying
degrees, but within the natural boundaries of the migration corridors.
Studies of gray, bowhead, and humpback whales have shown that
seismic pulses with received levels of 160 to 170 dB re: 1 [mu]Pa seem
to cause obvious avoidance behavior in a substantial fraction of the
animals exposed (Malme et al., 1986, 1988; Richardson et al., 1995). In
many areas, seismic pulses from large arrays of airguns diminish to
those levels at distances ranging from four to 15 km (2.5 to 9.3 mi)
from the source. A substantial proportion of the baleen whales within
those distances may show avoidance or other strong behavioral reactions
to the airgun array. Subtle behavioral changes sometimes become evident
at somewhat lower received levels, and studies summarized in the
Foundation's EA have shown that some species of baleen whales, notably
bowhead and humpback whales, at times show strong avoidance at received
levels lower than 160-170 dB re: 1 [mu]Pa.
Researchers have studied the responses of humpback whales to
seismic surveys during migration, feeding during the summer months,
breeding while offshore from Angola, and wintering offshore from
Brazil. McCauley et al. (1998, 2000a) studied the responses of humpback
whales off western Australia to a full-scale seismic survey with a 16-
airgun array (2,678-in\3\) and to a single, 20-in\3\ airgun with source
level of 227 dB re: 1 [mu]Pa (p-p). In the 1998 study, the researchers
documented that avoidance reactions began at five to eight km (3.1 to
4.9 mi) from the array, and that those reactions kept most pods
approximately three to four km (1.9 to 2.5 mi) from the operating
seismic boat. In the 2000 study, McCauley et al. noted localized
displacement during migration of four to five km (2.5 to 3.1 mi) by
traveling pods and seven to 12 km (4.3 to 7.5 mi) by more sensitive
resting pods of cow-calf pairs. Avoidance distances with respect to the
single airgun were smaller but consistent with the results from the
full array in terms of the received sound levels. The mean received
level for initial avoidance of an approaching airgun was 140 dB re: 1
[mu]Pa for humpback pods containing females, and at the mean closest
point of approach distance, the received level was 143 dB re: 1 [mu]Pa.
The initial avoidance response generally occurred at distances of five
to eight km (3.1 to 4.9 mi) from the airgun array and 2 km (1.2 mi)
from the single airgun. However, some individual humpback whales,
especially males, approached within distances of 100 to 400 m (328 to
1,312 ft), where the maximum received level was 179 dB re: 1 [mu]Pa.
Data collected by observers during several seismic surveys in the
northwest Atlantic Ocean showed that sighting rates of humpback whales
were significantly greater during non-seismic periods compared with
periods when a full array was operating (Moulton and Holst, 2010). In
addition, humpback whales were more likely to swim away and less likely
to swim towards a vessel during seismic versus non-seismic periods
(Moulton and Holst, 2010).
Humpback whales on their summer feeding grounds in southeast Alaska
did not exhibit persistent avoidance when exposed to seismic pulses
from a 1.64-L (100-in\3\) airgun (Malme et al., 1985). Some humpbacks
seemed ``startled'' at received levels of 150 to 169 dB re: 1 [mu]Pa.
Malme et al. (1985) concluded that there was no clear evidence of
avoidance, despite the possibility of subtle effects, at received
levels up to 172 re: 1 [mu]Pa. However, Moulton and Holst (2010)
reported that humpback whales monitored during seismic surveys in the
northwest Atlantic had lower sighting rates and were most often seen
swimming away from the vessel during seismic periods compared with
periods when airguns were silent.
Other studies have suggested that south Atlantic humpback whales
wintering off Brazil may be displaced or even strand upon exposure to
seismic surveys (Engel et al., 2004). However, the evidence for this
was circumstantial and subject to alternative explanations (IAGC,
2004). Also, the evidence was not consistent with subsequent results
from the same area of Brazil (Parente et al., 2006), or with direct
studies of humpbacks exposed to seismic surveys in other areas and
seasons. After allowance for data from subsequent years, there was ``no
observable direct correlation'' between strandings and seismic surveys
(IWC, 2007: 236).
A few studies have documented reactions of migrating and feeding
(but not wintering) gray whales to seismic surveys. Malme et al. (1986,
1988) studied the responses of feeding eastern Pacific gray whales to
pulses from a single 100-in\3\ airgun off St. Lawrence Island in the
northern Bering Sea. They estimated, based on small sample sizes, that
50 percent of feeding gray whales stopped feeding at an average
received pressure level of 173 dB re: 1 [mu]Pa on an (approximate) root
mean square basis, and that 10 percent of feeding whales interrupted
feeding at received levels of 163 dB re: 1 [micro]Pa. Those findings
were generally consistent with the results of experiments conducted on
larger numbers of gray whales that were migrating along the California
coast (Malme et al., 1984; Malme and Miles, 1985), and western Pacific
gray whales feeding off Sakhalin Island, Russia (Wursig et al., 1999;
Gailey et al., 2007; Johnson et al., 2007; Yazvenko et al., 2007a,
2007b), along with data on gray whales off British Columbia (Bain and
Williams, 2006).
Observers have seen various species of Balaenoptera (blue, sei,
fin, and minke whales) in areas ensonified by
[[Page 14788]]
airgun pulses (Stone, 2003; MacLean and Haley, 2004; Stone and Tasker,
2006), and have localized calls from blue and fin whales in areas with
airgun operations (e.g., McDonald et al., 1995; Dunn and Hernandez,
2009; Castellote et al., 2010). Sightings by observers on seismic
vessels off the United Kingdom from 1997 to 2000 suggest that, during
times of good sightability, sighting rates for mysticetes (mainly fin
and sei whales) were similar when large arrays of airguns were shooting
vs. silent (Stone, 2003; Stone and Tasker, 2006). However, these whales
tended to exhibit localized avoidance, remaining significantly further
(on average) from the airgun array during seismic operations compared
with non-seismic periods (Stone and Tasker, 2006). Castellote et al.
(2010) observed localized avoidance by fin whales during seismic airgun
events in the western Mediterranean Sea and adjacent Atlantic waters
from 2006-2009 and reported that singing fin whales moved away from an
operating airgun array for a time period that extended beyond the
duration of the airgun activity.
Ship-based monitoring studies of baleen whales (including blue,
fin, sei, minke, and whales) in the northwest Atlantic found that
overall, this group had lower sighting rates during seismic versus non-
seismic periods (Moulton and Holst, 2010). Baleen whales as a group
were also seen significantly farther from the vessel during seismic
compared with non-seismic periods, and they were more often seen to be
swimming away from the operating seismic vessel (Moulton and Holst,
2010). Blue and minke whales were initially sighted significantly
farther from the vessel during seismic operations compared to non-
seismic periods; the same trend was observed for fin whales (Moulton
and Holst, 2010). Minke whales were most often observed to be swimming
away from the vessel when seismic operations were underway (Moulton and
Holst, 2010).
Data on short-term reactions by cetaceans to impulsive noises are
not necessarily indicative of long-term or biologically significant
effects. It is not known whether impulsive sounds affect reproductive
rate or distribution and habitat use in subsequent days or years.
However, gray whales have continued to migrate annually along the west
coast of North America with substantial increases in the population
over recent years, despite intermittent seismic exploration (and much
ship traffic) in that area for decades (Appendix A in Malme et al.,
1984; Richardson et al., 1995; Allen and Angliss, 2011). The western
Pacific gray whale (Eschrichtius robustus) population did not appear
affected by a seismic survey in its feeding ground during a previous
year (Johnson et al., 2007). Similarly, bowhead whales have continued
to travel to the eastern Beaufort Sea each summer, and their numbers
have increased notably, despite seismic exploration in their summer and
autumn range for many years (Richardson et al., 1987; Allen and
Angliss, 2011). The history of coexistence between seismic surveys and
baleen whales suggests that brief exposures to sound pulses from any
single seismic survey are unlikely to result in prolonged effects.
Toothed Whales--There is little systematic information available
about reactions of toothed whales to noise pulses. There are few
studies on toothed whales similar to the more extensive baleen whale/
seismic pulse work summarized earlier in this notice. However, there
are recent systematic studies on sperm whales (e.g., Gordon et al.,
2006; Madsen et al., 2006; Winsor and Mate, 2006; Jochens et al., 2008;
Miller et al., 2009). There is an increasing amount of information
about responses of various odontocetes to seismic surveys based on
monitoring studies (e.g., Stone, 2003; Smultea et al., 2004; Moulton
and Miller, 2005; Bain and Williams, 2006; Holst et al., 2006; Stone
and Tasker, 2006; Potter et al., 2007; Hauser et al., 2008; Holst and
Smultea, 2008; Weir, 2008; Barkaszi et al., 2009; Richardson et al.,
2009; Moulton and Holst, 2010).
Seismic operators and protected species observers (observers) on
seismic vessels regularly see dolphins and other small toothed whales
near operating airgun arrays, but in general there is a tendency for
most delphinids to show some avoidance of operating seismic vessels
(e.g., Goold, 1996a,b,c; Calambokidis and Osmek, 1998; Stone, 2003;
Moulton and Miller, 2005; Holst et al., 2006; Stone and Tasker, 2006;
Weir, 2008; Richardson et al., 2009; Barkaszi et al., 2009; Moulton and
Holst, 2010). Some dolphins seem to be attracted to the seismic vessel
and floats, and some ride the bow wave of the seismic vessel even when
large arrays of airguns are firing (e.g., Moulton and Miller, 2005).
Nonetheless, small toothed whales more often tend to head away, or to
maintain a somewhat greater distance from the vessel, when a large
array of airguns is operating than when it is silent (e.g., Stone and
Tasker, 2006; Weir, 2008, Barry et al., 2010; Moulton and Holst, 2010).
In most cases, the avoidance radii for delphinids appear to be small,
on the order of one km or less, and some individuals show no apparent
avoidance.
Captive bottlenose dolphins and beluga whales (Delphinapterus
leucas) exhibited changes in behavior when exposed to strong pulsed
sounds similar in duration to those typically used in seismic surveys
(Finneran et al., 2000, 2002, 2005). However, the animals tolerated
high received levels of sound before exhibiting aversive behaviors.
Results for porpoises depend on species. The limited available data
suggest that harbor porpoises (Phocoena phocoena) show stronger
avoidance of seismic operations than do Dall's porpoises (Stone, 2003;
MacLean and Koski, 2005; Bain and Williams, 2006; Stone and Tasker,
2006). Dall's porpoises seem relatively tolerant of airgun operations
(MacLean and Koski, 2005; Bain and Williams, 2006), although they too
have been observed to avoid large arrays of operating airguns
(Calambokidis and Osmek, 1998; Bain and Williams, 2006). This apparent
difference in responsiveness of these two porpoise species is
consistent with their relative responsiveness to boat traffic and some
other acoustic sources (Richardson et al., 1995; Southall et al.,
2007).
Most studies of sperm whales exposed to airgun sounds indicate that
the whale shows considerable tolerance of airgun pulses (e.g., Stone,
2003; Moulton et al., 2005, 2006a; Stone and Tasker, 2006; Weir, 2008).
In most cases the whales do not show strong avoidance, and they
continue to call. However, controlled exposure experiments in the Gulf
of Mexico indicate that foraging behavior was altered upon exposure to
airgun sound (Jochens et al., 2008; Miller et al., 2009; Tyack, 2009).
There are almost no specific data on the behavioral reactions of
beaked whales to seismic surveys. However, some northern bottlenose
whales (Hyperoodon ampullatus) remained in the general area and
continued to produce high-frequency clicks when exposed to sound pulses
from distant seismic surveys (Gosselin and Lawson, 2004; Laurinolli and
Cochrane, 2005; Simard et al., 2005). Most beaked whales tend to avoid
approaching vessels of other types (e.g., Wursig et al., 1998). They
may also dive for an extended period when approached by a vessel (e.g.,
Kasuya, 1986), although it is uncertain how much longer such dives may
be as compared to dives by undisturbed beaked whales, which also are
often quite long (Baird et al., 2006; Tyack et al., 2006). Based on a
single observation, Aguilar-Soto et al. (2006) suggested that foraging
efficiency of Cuvier's beaked whales (Ziphius
[[Page 14789]]
cavirostris) may be reduced by close approach of vessels. In any event,
it is likely that most beaked whales would also show strong avoidance
of an approaching seismic vessel, although this has not been documented
explicitly. In fact, Moulton and Holst (2010) reported 15 sightings of
beaked whales during seismic studies in the northwest Atlantic; seven
of those sightings were made at times when at least one airgun was
operating. There was little evidence to indicate that beaked whale
behavior was affected by airgun operations; sighting rates and
distances were similar during seismic and non-seismic periods (Moulton
and Holst, 2010).
Pinnipeds are not likely to show a strong avoidance reaction to the
airgun sources proposed for use. Visual monitoring from seismic vessels
has shown only slight (if any) avoidance of airguns by pinnipeds and
only slight (if any) changes in behavior. Monitoring work in the
Alaskan Beaufort Sea during 1996-2001 provided considerable information
regarding the behavior of Arctic ice seals exposed to seismic pulses
(Harris et al., 2001; Moulton and Lawson, 2002). These seismic projects
usually involved arrays of 6 to 16 airguns with total volumes of 560 to
1,500 in\3\. The combined results suggest that some seals avoid the
immediate area around seismic vessels. In most survey years, ringed
seal sightings tended to be farther away from the seismic vessel when
the airguns were operating than when they were not (Moulton and Lawson,
2002). However, these avoidance movements were relatively small, on the
order of 100 m (328 ft) to a few hundreds of meters, and many seals
remained within 100-200 m (328-656 ft) of the trackline as the
operating airgun array passed by. Seal sighting rates at the water
surface were lower during airgun array operations than during no-airgun
periods in each survey year except 1997. Similarly, seals are often
very tolerant of pulsed sounds from seal-scaring devices (Mate and
Harvey, 1987; Jefferson and Curry, 1994; Richardson et al., 1995).
However, initial telemetry work suggests that avoidance and other
behavioral reactions by two other species of seals to small airgun
sources may at times be stronger than evident to date from visual
studies of pinniped reactions to airguns (Thompson et al., 1998).
Hearing Impairment
Exposure to high intensity sound for a sufficient duration may
result in auditory effects such as a noise-induced threshold shift--an
increase in the auditory threshold after exposure to noise (Finneran et
al., 2005). Factors that influence the amount of threshold shift
include the amplitude, duration, frequency content, temporal pattern,
and energy distribution of noise exposure. The magnitude of hearing
threshold shift normally decreases over time following cessation of the
noise exposure. The amount of threshold shift just after exposure is
the initial threshold shift. If the threshold shift eventually returns
to zero (i.e., the threshold returns to the pre-exposure value), it is
a temporary threshold shift (Southall et al., 2007).
Researchers have studied temporary threshold shift in certain
captive odontocetes and pinnipeds exposed to strong sounds (reviewed in
Southall et al., 2007). However, there has been no specific
documentation of temporary threshold shift let alone permanent hearing
damage, (i.e., permanent threshold shift, in free-ranging marine
mammals exposed to sequences of airgun pulses during realistic field
conditions).
Threshold Shift (noise-induced loss of hearing)--When animals
exhibit reduced hearing sensitivity (i.e., sounds must be louder for an
animal to detect them) following exposure to an intense sound or sound
for long duration, it is referred to as a noise-induced threshold shift
(TS). An animal can experience temporary threshold shift (TTS) or
permanent threshold shift (PTS). TTS can last from minutes or hours to
days (i.e., there is complete recovery), can occur in specific
frequency ranges (i.e., an animal might only have a temporary loss of
hearing sensitivity between the frequencies of 1 and 10 kHz), and can
be of varying amounts (for example, an animal's hearing sensitivity
might be reduced initially by only 6 dB or reduced by 30 dB). PTS is
permanent, but some recovery is possible. PTS can also occur in a
specific frequency range and amount as mentioned above for TTS.
The following physiological mechanisms are thought to play a role
in inducing auditory TS: Effects to sensory hair cells in the inner ear
that reduce their sensitivity, modification of the chemical environment
within the sensory cells, residual muscular activity in the middle ear,
displacement of certain inner ear membranes, increased blood flow, and
post-stimulatory reduction in both efferent and sensory neural output
(Southall et al., 2007). The amplitude, duration, frequency, temporal
pattern, and energy distribution of sound exposure all can affect the
amount of associated TS and the frequency range in which it occurs. As
amplitude and duration of sound exposure increase, so, generally, does
the amount of TS, along with the recovery time. For intermittent
sounds, less TS could occur than compared to a continuous exposure with
the same energy (some recovery could occur between intermittent
exposures depending on the duty cycle between sounds) (Kryter et al.,
1966; Ward, 1997). For example, one short but loud (higher SPL) sound
exposure may induce the same impairment as one longer but softer sound,
which in turn may cause more impairment than a series of several
intermittent softer sounds with the same total energy (Ward, 1997).
Additionally, though TTS is temporary, prolonged exposure to sounds
strong enough to elicit TTS, or shorter-term exposure to sound levels
well above the TTS threshold, can cause PTS, at least in terrestrial
mammals (Kryter, 1985). Although in the case of the seismic survey,
animals are not expected to be exposed to levels high enough or
durations long enough to result in PTS.
PTS is considered auditory injury (Southall et al., 2007).
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).
Although the published body of scientific literature contains
numerous theoretical studies and discussion papers on hearing
impairments that can occur with exposure to a loud sound, only a few
studies provide empirical information on the levels at which noise-
induced loss in hearing sensitivity occurs in nonhuman animals. For
marine mammals, published data are limited to the captive bottlenose
dolphin, beluga, harbor porpoise, and Yangtze finless porpoise
(Finneran et al., 2000, 2002b, 2003, 2005a, 2007, 2010a, 2010b;
Finneran and Schlundt, 2010; Lucke et al., 2009; Mooney et al., 2009a,
2009b; Popov et al., 2011a, 2011b; Kastelein et al., 2012a; Schlundt et
al., 2000; Nachtigall et al., 2003, 2004). For pinnipeds in water, data
are limited to measurements of TTS in harbor seals, an elephant seal,
and California sea lions (Kastak et al., 1999, 2005; Kastelein et al.,
2012b).
Marine mammal hearing plays a critical role in communication with
conspecifics, and 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
[[Page 14790]]
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 (similar to those discussed in auditory
masking, below). For example, a marine mammal may be able to readily
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that occurs during a time 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 time when communication is critical for successful mother/calf
interactions could have more serious impacts. Also, depending on the
degree and frequency range, the effects of PTS on an animal could range
in severity, although it is considered generally more serious because
it is a permanent condition. Of note, reduced hearing sensitivity as a
simple function of aging has been observed in marine mammals, as well
as humans and other taxa (Southall et al., 2007), so we can infer that
strategies exist for coping with this condition to some degree, though
likely not without cost.
Given the higher level of sound necessary to cause PTS as compared
with TTS, it is considerably less likely that PTS would occur during
the proposed seismic survey in Cook Inlet. Cetaceans generally avoid
the immediate area around operating seismic vessels, as do some other
marine mammals. Some pinnipeds show avoidance reactions to airguns, but
their avoidance reactions are generally not as strong or consistent as
those of cetaceans, and occasionally they seem to be attracted to
operating seismic vessels (NMFS, 2010).
Non-auditory Physical Effects: Non-auditory physical effects might
occur in marine mammals exposed to strong underwater pulsed sound.
Possible types of non-auditory physiological effects or injuries that
theoretically might occur in mammals close to a strong sound source
include stress, neurological effects, bubble formation, and other types
of organ or tissue damage. Some marine mammal species (i.e., beaked
whales) may be especially susceptible to injury and/or stranding when
exposed to strong pulsed sounds.
Classic stress responses begin when an animal's central nervous
system perceives a potential threat to its homeostasis. That perception
triggers stress responses regardless of whether a stimulus actually
threatens the animal; the mere perception of a threat is sufficient to
trigger a stress response (Moberg, 2000; Sapolsky et al., 2005; Seyle,
1950). Once an animal's central nervous system perceives a threat, it
mounts a biological response or defense that consists of a combination
of the four general biological defense responses: Behavioral responses;
autonomic nervous system responses; neuroendocrine responses; or immune
responses.
In the case of many stressors, an animal's first and most
economical (in terms of biotic costs) response is behavioral avoidance
of the potential stressor or avoidance of continued exposure to a
stressor. An animal's second line of defense to stressors involves the
sympathetic part of the autonomic nervous system and the classical
``fight or flight'' response, which includes the cardiovascular system,
the gastrointestinal system, the exocrine glands, and the adrenal
medulla to produce changes in heart rate, blood pressure, and
gastrointestinal activity that humans commonly associate with
``stress.'' These responses have a relatively short duration and may or
may not have significant long-term effects on an animal's welfare.
An animal's third line of defense to stressors involves its
neuroendocrine or sympathetic nervous systems; the system that has
received the most study has been the hypothalmus-pituitary-adrenal
system (also known as the HPA axis in mammals or the hypothalamus-
pituitary-interrenal axis in fish and some reptiles). Unlike stress
responses associated with the autonomic nervous system, the pituitary
hormones regulate virtually all neuroendocrine functions affected by
stress--including immune competence, reproduction, metabolism, and
behavior. Stress-induced changes in the secretion of pituitary hormones
have been implicated in failed reproduction (Moberg, 1987; Rivier,
1995), altered metabolism (Elasser et al., 2000), reduced immune
competence (Blecha, 2000), and behavioral disturbance. Increases in the
circulation of glucocorticosteroids (cortisol, corticosterone, and
aldosterone in marine mammals; see Romano et al., 2004) have been
equated with stress for many years.
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and distress is the biotic cost
of the response. During a stress response, an animal uses glycogen
stores that are quickly replenished once the stress is alleviated. In
such circumstances, the cost of the stress response would not pose a
risk to the animal's welfare. However, when an animal does not have
sufficient energy reserves to satisfy the energetic costs of a stress
response, energy resources must be diverted from other biotic
functions, which impair those functions that experience the diversion.
For example, when mounting a stress response diverts energy away from
growth in young animals, those animals may experience stunted growth.
When mounting a stress response diverts energy from a fetus, an
animal's reproductive success and fitness will suffer. In these cases,
the animals will have entered a pre-pathological or pathological state
which is called ``distress'' (sensu Seyle, 1950) or ``allostatic
loading'' (sensu McEwen and Wingfield, 2003). This pathological state
will last until the animal replenishes its biotic reserves sufficient
to restore normal function. Note that these examples involved a long-
term (days or weeks) stress response exposure to stimuli.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses have also been documented
fairly well through controlled experiment; because this physiology
exists in every vertebrate that has been studied, it is not surprising
that stress responses and their costs have been documented in both
laboratory and free-living animals (for examples see, Holberton et al.,
1996; Hood et al., 1998; Jessop et al., 2003; Krausman et al., 2004;
Lankford et al., 2005; Reneerkens et al., 2002; Thompson and Hamer,
2000). Although no information has been collected on the physiological
responses of marine mammals to anthropogenic sound exposure, studies of
other marine animals and terrestrial animals would lead us to expect
some marine mammals to experience physiological stress responses and,
perhaps, physiological responses that would be classified as
``distress'' upon exposure to anthropogenic sounds.
For example, Jansen (1998) reported on the relationship between
acoustic exposures and physiological responses that are indicative of
stress responses in humans (e.g., elevated respiration and increased
heart rates). Jones (1998) reported on reductions in human performance
when faced with acute, repetitive exposures to acoustic disturbance.
Trimper et al. (1998) reported on the physiological stress responses of
osprey to low-level aircraft noise while Krausman et al. (2004)
reported on the auditory and physiology stress responses of endangered
Sonoran pronghorn to military overflights. Smith et al. (2004a, 2004b)
identified noise-induced physiological transient stress responses in
hearing-specialist fish (i.e., goldfish) that accompanied short- and
long-term hearing losses. Welch and Welch (1970) reported physiological
[[Page 14791]]
and behavioral stress responses that accompanied damage to the inner
ears of fish and several mammals.
Hearing is one of the primary senses marine mammals use to gather
information about their environment and communicate with conspecifics.
Although empirical information on the relationship between sensory
impairment (TTS, PTS, and acoustic masking) on marine mammals remains
limited, we assume that reducing a marine mammal's ability to gather
information about its environment and communicate with other members of
its species would induce stress, based on data that terrestrial animals
exhibit those responses under similar conditions (NRC, 2003) and
because marine mammals use hearing as their primary sensory mechanism.
Therefore, we assume that acoustic exposures sufficient to trigger
onset PTS or TTS would be accompanied by physiological stress
responses. More importantly, marine mammals might experience stress
responses at received levels lower than those necessary to trigger
onset TTS. Based on empirical studies of the time required to recover
from stress responses (Moberg, 2000), NMFS also assumes that stress
responses could persist beyond the time interval required for animals
to recover from TTS and might result in pathological and pre-
pathological states that would be as significant as behavioral
responses to TTS. However, as stated previously in this document, the
source levels of the drillships are not loud enough to induce PTS or
likely even TTS.
Resonance effects (Gentry, 2002) and direct noise-induced bubble
formations (Crum et al., 2005) are implausible in the case of exposure
to an impulsive broadband source like an airgun array. If seismic
surveys disrupt diving patterns of deep-diving species, this might
result in bubble formation and a form of the bends, as speculated to
occur in beaked whales exposed to sonar. However, there is no specific
evidence of this upon exposure to airgun pulses. Additionally, no
beaked whale species occur in the proposed seismic survey area.
In general, there are few data about the potential for strong,
anthropogenic underwater sounds to cause non-auditory physical effects
in marine mammals. Such effects, if they occur at all, would presumably
be limited to short distances and to activities that extend over a
prolonged period. The available data do not allow identification of a
specific exposure level above which non-auditory effects can be
expected (Southall et al., 2007) or any meaningful quantitative
predictions of the numbers (if any) of marine mammals that might be
affected in those ways. There is no definitive evidence that any of
these effects occur even for marine mammals in close proximity to large
arrays of airguns. In addition, marine mammals that show behavioral
avoidance of seismic vessels, including pinnipeds, are especially
unlikely to incur non-auditory impairment or other physical effects.
Therefore, it is unlikely that such effects would occur during the
Observatory's proposed surveys given the brief duration of exposure and
the planned monitoring and mitigation measures described later in this
document.
Stranding and Mortality
When a living or dead marine mammal swims or floats onto shore and
becomes ``beached'' or incapable of returning to sea, the event is a
``stranding'' (Geraci et al., 1999; Perrin and Geraci, 2002; Geraci and
Lounsbury, 2005; NMFS, 2007). The legal definition for a stranding
under the MMPA is that ``(A) a marine mammal is dead and is (i) on a
beach or shore of the United States; or (ii) in waters under the
jurisdiction of the United States (including any navigable waters); or
(B) a marine mammal is alive and is (i) on a beach or shore of the
United States and is unable to return to the water; (ii) on a beach or
shore of the United States and, although able to return to the water,
is in need of apparent medical attention; or (iii) in the waters under
the jurisdiction of the United States (including any navigable waters),
but is unable to return to its natural habitat under its own power or
without assistance''.
Marine mammals strand for a variety of reasons, such as infectious
agents, biotoxicosis, starvation, fishery interaction, ship strike,
unusual oceanographic or weather events, sound exposure, or
combinations of these stressors sustained concurrently or in series.
However, the cause or causes of most strandings are unknown (Geraci et
al., 1976; Eaton, 1979; Odell et al., 1980; Best, 1982). Numerous
studies suggest that the physiology, behavior, habitat relationships,
age, or condition of cetaceans may cause them to strand or might pre-
dispose them to strand when exposed to another phenomenon. These
suggestions are consistent with the conclusions of numerous other
studies that have demonstrated that combinations of dissimilar
stressors commonly combine to kill an animal or dramatically reduce its
fitness, even though one exposure without the other does not produce
the same result (Chroussos, 2000; Creel, 2005; DeVries et al., 2003;
Fair and Becker, 2000; Foley et al., 2001; Moberg, 2000; Relyea, 2005a;
2005b, Romero, 2004; Sih et al., 2004).
Potential Effects of Other Acoustic Devices
Multibeam Echosounder
The Observatory would operate the Kongsberg EM 122 multibeam
echosounder from the source vessel during the planned study. Sounds
from the multibeam echosounder are very short pulses, occurring for two
to 15 ms once every five to 20 s, depending on water depth. Most of the
energy in the sound pulses emitted by this echosounder is at
frequencies near 12 kHz, and the maximum source level is 242 dB re: 1
[mu]Pa. The beam is narrow (1 to 2[deg]) in fore-aft extent and wide
(150[deg]) in the cross-track extent. Each ping consists of eight (in
water greater than 1,000 m deep) or four (less than 1,000 m deep)
successive fan-shaped transmissions (segments) at different cross-track
angles. Any given mammal at depth near the trackline would be in the
main beam for only one or two of the segments. Also, marine mammals
that encounter the Kongsberg EM 122 are unlikely to be subjected to
repeated pulses because of the narrow fore-aft width of the beam and
will receive only limited amounts of pulse energy because of the short
pulses. Animals close to the vessel (where the beam is narrowest) are
especially unlikely to be ensonified for more than one 2- to 15-ms
pulse (or two pulses if in the overlap area). Similarly, Kremser et al.
(2005) noted that the probability of a cetacean swimming through the
area of exposure when an echosounder emits a pulse is small. The animal
would have to pass the transducer at close range and be swimming at
speeds similar to the vessel in order to receive the multiple pulses
that might result in sufficient exposure to cause temporary threshold
shift.
Navy sonars linked to avoidance reactions and stranding of
cetaceans: (1) Generally have longer pulse duration than the Kongsberg
EM 122; and (2) are often directed close to horizontally versus more
downward for the echosounder. The area of possible influence of the
echosounder is much smaller--a narrow band below the source vessel.
Also, the duration of exposure for a given marine mammal can be much
longer for naval sonar. During the Observatory's operations, the
individual pulses will be very short, and a given mammal would not
receive many of the downward-directed pulses as the vessel passes by
the animal. The
[[Page 14792]]
following section outlines possible effects of an echosounder on marine
mammals.
Masking--Marine mammal communications would not be masked
appreciably by the echosounder's signals given the low duty cycle of
the echosounder and the brief period when an individual mammal is
likely to be within its beam. Furthermore, in the case of baleen
whales, the echosounder's signals (12 kHz) do not overlap with the
predominant frequencies in the calls, which would avoid any significant
masking.
Behavioral Responses--Behavioral reactions of free-ranging marine
mammals to sonars, echosounders, and other sound sources appear to vary
by species and circumstance. Observed reactions have included silencing
and dispersal by sperm whales (Watkins et al., 1985), increased
vocalizations and no dispersal by pilot whales (Globicephala melas)
(Rendell and Gordon, 1999), and the previously-mentioned beachings by
beaked whales. During exposure to a 21 to 25 kHz ``whale-finding''
sonar with a source level of 215 dB re: 1 [micro]Pa, gray whales
reacted by orienting slightly away from the source and being deflected
from their course by approximately 200 m (Frankel, 2005). When a 38-kHz
echosounder and a 150-kHz acoustic Doppler current profiler were
transmitting during studies in the eastern tropical Pacific Ocean,
baleen whales showed no significant responses, while spotted and
spinner dolphins were detected slightly more often and beaked whales
less often during visual surveys (Gerrodette and Pettis, 2005).
Captive bottlenose dolphins and a beluga whale exhibited changes in
behavior when exposed to 1-s tonal signals at frequencies similar to
those emitted by the Observatory's echosounder, and to shorter
broadband pulsed signals. Behavioral changes typically involved what
appeared to be deliberate attempts to avoid the sound exposure
(Schlundt et al., 2000; Finneran et al., 2002; Finneran and Schlundt,
2004). The relevance of those data to free-ranging odontocetes is
uncertain, and in any case, the test sounds were quite different in
duration as compared with those from an echosounder.
Hearing Impairment and Other Physical Effects--Given recent
stranding events that have been associated with the operation of naval
sonar, there is concern that mid-frequency sonar sounds can cause
serious impacts to marine mammals (see above). However, the echosounder
proposed for use by the Langseth is quite different than sonar used for
navy operations. The echosounder's pulse duration is very short
relative to the naval sonar. Also, at any given location, an individual
marine mammal would be in the echosounder's beam for much less time
given the generally downward orientation of the beam and its narrow
fore-aft beamwidth; navy sonar often uses near-horizontally-directed
sound. Those factors would all reduce the sound energy received from
the echosounder relative to that from naval sonar.
Based upon the best available science, we believe that the brief
exposure of marine mammals to one pulse, or small numbers of signals,
from the echosounder is not likely to result in the harassment of
marine mammals.
Sub-Bottom Profiler
The Observatory would also operate a sub-bottom profiler from the
source vessel during the proposed survey. The profiler's sounds are
very short pulses, occurring for one to four ms once every second. Most
of the energy in the sound pulses emitted by the profiler is at 3.5
kHz, and the beam is directed downward. The sub-bottom profiler on the
Langseth has a maximum source level of 222 dB re: 1 [micro]Pa. Kremser
et al. (2005) noted that the probability of a cetacean swimming through
the area of exposure when a bottom profiler emits a pulse is small--
even for a profiler more powerful than that on the Langseth--if the
animal was in the area, it would have to pass the transducer at close
range and in order to be subjected to sound levels that could cause
temporary threshold shift.
Masking--Marine mammal communications would not be masked
appreciably by the profiler's signals given the directionality of the
signal and the brief period when an individual mammal is likely to be
within its beam. Furthermore, in the case of most baleen whales, the
profiler's signals do not overlap with the predominant frequencies in
the calls, which would avoid significant masking.
Behavioral Responses--Marine mammal behavioral reactions to other
pulsed sound sources are discussed above, and responses to the profiler
are likely to be similar to those for other pulsed sources if received
at the same levels. However, the pulsed signals from the profiler are
considerably weaker than those from the echosounder. Therefore,
behavioral responses are not expected unless marine mammals are very
close to the source.
Hearing Impairment and Other Physical Effects--It is unlikely that
the profiler produces pulse levels strong enough to cause hearing
impairment or other physical injuries even in an animal that is
(briefly) in a position near the source. The profiler operates
simultaneously with other higher-power acoustic sources. Many marine
mammals would move away in response to the approaching higher-power
sources or the vessel itself before the mammals would be close enough
for there to be any possibility of effects from the less intense sounds
from the profiler.
Potential Effects of Vessel Movement and Collisions
Vessel movement in the vicinity of marine mammals has the potential
to result in either a behavioral response or a direct physical
interaction. Both scenarios are discussed below this section.
Behavioral Responses to Vessel Movement
There are limited data concerning marine mammal behavioral
responses to vessel traffic and vessel noise, and a lack of consensus
among scientists with respect to what these responses mean or whether
they result in short-term or long-term adverse effects. In those cases
where there is a busy shipping lane or where there is a large amount of
vessel traffic, marine mammals may experience acoustic masking
(Hildebrand, 2005) if they are present in the area (e.g., killer whales
in Puget Sound; Foote et al., 2004; Holt et al., 2008). In cases where
vessels actively approach marine mammals (e.g., whale watching or
dolphin watching boats), scientists have documented that animals
exhibit altered behavior such as increased swimming speed, erratic
movement, and active avoidance behavior (Bursk, 1983; Acevedo, 1991;
Baker and MacGibbon, 1991; Trites and Bain, 2000; Williams et al.,
2002; Constantine et al., 2003), reduced blow interval (Ritcher et al.,
2003), disruption of normal social behaviors (Lusseau, 2003; 2006), and
the shift of behavioral activities which may increase energetic costs
(Constantine et al., 2003; 2004)). A detailed review of marine mammal
reactions to ships and boats is available in Richardson et al. (1995).
For each of the marine mammal taxonomy groups, Richardson et al. (1995)
provides the following assessment regarding reactions to vessel
traffic:
Toothed whales: ``In summary, toothed whales sometimes show no
avoidance reaction to vessels, or even approach them. However,
avoidance can occur, especially in response to vessels of types used to
chase or hunt the animals. This may cause temporary
[[Page 14793]]
displacement, but we know of no clear evidence that toothed whales have
abandoned significant parts of their range because of vessel traffic.''
Baleen whales: ``When baleen whales receive low-level sounds from
distant or stationary vessels, the sounds often seem to be ignored.
Some whales approach the sources of these sounds. When vessels approach
whales slowly and non-aggressively, whales often exhibit slow and
inconspicuous avoidance maneuvers. In response to strong or rapidly
changing vessel noise, baleen whales often interrupt their normal
behavior and swim rapidly away. Avoidance is especially strong when a
boat heads directly toward the whale.''
Behavioral responses to stimuli are complex and influenced to
varying degrees by a number of factors, such as species, behavioral
contexts, geographical regions, source characteristics (moving or
stationary, speed, direction, etc.), prior experience of the animal and
physical status of the animal. For example, studies have shown that
beluga whales' reactions varied when exposed to vessel noise and
traffic. In some cases, naive beluga whales exhibited rapid swimming
from ice-breaking vessels up to 80 km (49.7 mi) away, and showed
changes in surfacing, breathing, diving, and group composition in the
Canadian high Arctic where vessel traffic is rare (Finley et al.,
1990). In other cases, beluga whales were more tolerant of vessels, but
responded differentially to certain vessels and operating
characteristics by reducing their calling rates (especially older
animals) in the St. Lawrence River where vessel traffic is common
(Blane and Jaakson, 1994). In Bristol Bay, Alaska, beluga whales
continued to feed when surrounded by fishing vessels and resisted
dispersal even when purposefully harassed (Fish and Vania, 1971).
In reviewing more than 25 years of whale observation data, Watkins
(1986) concluded that whale reactions to vessel traffic were ``modified
by their previous experience and current activity: Habituation often
occurred rapidly, attention to other stimuli or preoccupation with
other activities sometimes overcame their interest or wariness of
stimuli.'' Watkins noticed that over the years of exposure to ships in
the Cape Cod area, minke whales changed from frequent positive interest
(e.g., approaching vessels) to generally uninterested reactions; fin
whales changed from mostly negative (e.g., avoidance) to uninterested
reactions; right whales apparently continued the same variety of
responses (negative, uninterested, and positive responses) with little
change; and humpbacks dramatically changed from mixed responses that
were often negative to reactions that were often strongly positive.
Watkins (1986) summarized that ``whales near shore, even in regions
with low vessel traffic, generally have become less wary of boats and
their noises, and they have appeared to be less easily disturbed than
previously. In particular locations with intense shipping and repeated
approaches by boats (such as the whale-watching areas of Stellwagen
Bank), more and more whales had positive reactions to familiar vessels,
and they also occasionally approached other boats and yachts in the
same ways.''
Although the radiated sound from the Langseth would be audible to
marine mammals over a large distance, it is unlikely that animals would
respond behaviorally (in a manner that we would consider MMPA
harassment) to low-level distant shipping noise as the animals in the
area are likely to be habituated to such noises (Nowacek et al., 2004).
In light of these facts, we do not expect the Langseth's movements to
result in Level B harassment.
Vessel Strike
Ship strikes of cetaceans can cause major wounds, which may lead to
the death of the animal. An animal at the surface could be struck
directly by a vessel, a surfacing animal could hit the bottom of a
vessel, or an animal just below the surface could be cut by a vessel's
propeller. The severity of injuries typically depends on the size and
speed of the vessel (Knowlton and Kraus, 2001; Laist et al., 2001;
Vanderlaan and Taggart, 2007).
The most vulnerable marine mammals are those that spend extended
periods of time at the surface in order to restore oxygen levels within
their tissues after deep dives (e.g., the sperm whale). In addition,
some baleen whales, such as the North Atlantic right whale, seem
generally unresponsive to vessel sound, making them more susceptible to
vessel collisions (Nowacek et al., 2004). These species are primarily
large, slow moving whales. Smaller marine mammals (e.g., bottlenose
dolphin) move quickly through the water column and are often seen
riding the bow wave of large ships. Marine mammal responses to vessels
may include avoidance and changes in dive pattern (NRC, 2003).
An examination of all known ship strikes from all shipping sources
(civilian and military) indicates vessel speed is a principal factor in
whether a vessel strike results in death (Knowlton and Kraus, 2001;
Laist et al., 2001; Jensen and Silber, 2003; Vanderlaan and Taggart,
2007). In assessing records with known vessel speeds, Laist et al.
(2001) found a direct relationship between the occurrence of a whale
strike and the speed of the vessel involved in the collision. The
authors concluded that most deaths occurred when a vessel was traveling
in excess of 24.1 km/h (14.9 mph; 13 kts).
Entanglement
Entanglement can occur if wildlife becomes immobilized in survey
lines, cables, nets, or other equipment that is moving through the
water column. The proposed seismic survey would require towing
approximately 8.0 km (4.9 mi) of equipment and cables. This large of an
array carries the risk of entanglement for marine mammals. Wildlife,
especially slow moving individuals, such as large whales, have a low
probability of entanglement due to slow speed of the survey vessel and
onboard monitoring efforts. The Observatory has no recorded cases of
entanglement of marine mammals during the conduct of over 8 years of
seismic surveys covering over 160,934 km (86,897.4 nmi) of transect
lines.
In May, 2011, there was one recorded entanglement of an olive
ridley sea turtle (Lepidochelys olivacea) in the Langseth's barovanes
after the conclusion of a seismic survey off Costa Rica (LGL, 2011).
Anticipated Effects on Marine Mammal Habitat
The primary potential impacts to marine mammal habitat and other
marine species are associated with elevated sound levels produced by
airguns and other active acoustic sources. This section describes the
potential impacts to marine mammal habitat from the specified activity.
Anticipated Effects on Fish
One reason for the adoption of airguns as the standard energy
source for marine seismic surveys is that, unlike explosives, they have
not been associated with large-scale fish kills. However, existing
information on the impacts of seismic surveys on marine fish
populations is limited. There are three types of potential effects of
exposure to seismic surveys: (1) Pathological, (2) physiological, and
(3) behavioral. Pathological effects involve lethal and temporary or
permanent sub-lethal injury. Physiological effects involve temporary
and permanent primary and secondary stress responses, such as changes
in levels of enzymes and proteins. Behavioral effects refer to
temporary and (if they occur) permanent
[[Page 14794]]
changes in exhibited behavior (e.g., startle and avoidance behavior).
The three categories are interrelated in complex ways. For example, it
is possible that certain physiological and behavioral changes could
potentially lead to an ultimate pathological effect on individuals
(i.e., mortality).
The specific received sound levels at which permanent adverse
effects to fish potentially could occur are little studied and largely
unknown. Furthermore, the available information on the impacts of
seismic surveys on marine fish is from studies of individuals or
portions of a population; there have been no studies at the population
scale. The studies of individual fish have often been on caged fish
that were exposed to airgun pulses in situations not representative of
an actual seismic survey. Thus, available information provides limited
insight on possible real-world effects at the ocean or population
scale.
Hastings and Popper (2005), Popper (2009), and Popper and Hastings
(2009a,b) provided recent critical reviews of the known effects of
sound on fish. The following sections provide a general synopsis of the
available information on the effects of exposure to seismic and other
anthropogenic sound as relevant to fish. The information comprises
results from scientific studies of varying degrees of rigor plus some
anecdotal information. Some of the data sources may have serious
shortcomings in methods, analysis, interpretation, and reproducibility
that must be considered when interpreting their results (see Hastings
and Popper, 2005). Potential adverse effects of the program's sound
sources on marine fish are noted.
Pathological Effects--The potential for pathological damage to
hearing structures in fish depends on the energy level of the received
sound and the physiology and hearing capability of the species in
question. For a given sound to result in hearing loss, the sound must
exceed, by some substantial amount, the hearing threshold of the fish
for that sound (Popper, 2005). The consequences of temporary or
permanent hearing loss in individual fish on a fish population are
unknown; however, they likely depend on the number of individuals
affected and whether critical behaviors involving sound (e.g., predator
avoidance, prey capture, orientation and navigation, reproduction,
etc.) are adversely affected.
There are few data about the mechanisms and characteristics of
damage impacting fish that by exposure to seismic survey sounds. Peer-
reviewed scientific literature has presented few data on this subject.
NMFS is aware of only two papers with proper experimental methods,
controls, and careful pathological investigation that implicate sounds
produced by actual seismic survey airguns in causing adverse anatomical
effects. One such study indicated anatomical damage, and the second
indicated temporary threshold shift in fish hearing. The anatomical
case is McCauley et al. (2003), who found that exposure to airgun sound
caused observable anatomical damage to the auditory maculae of pink
snapper (Pagrus auratus). This damage in the ears had not been repaired
in fish sacrificed and examined almost two months after exposure. On
the other hand, Popper et al. (2005) documented only temporary
threshold shift (as determined by auditory brainstem response) in two
of three fish species from the Mackenzie River Delta. This study found
that broad whitefish (Coregonus nasus) exposed to five airgun shots
were not significantly different from those of controls. During both
studies, the repetitive exposure to sound was greater than would have
occurred during a typical seismic survey. However, the substantial low-
frequency energy produced by the airguns (less than 400 Hz in the study
by McCauley et al. (2003) and less than approximately 200 Hz in Popper
et al. (2005)) likely did not propagate to the fish because the water
in the study areas was very shallow (approximately 9 m in the former
case and less than 2 m in the latter). Water depth sets a lower limit
on the lowest sound frequency that will propagate (i.e., the cutoff
frequency) at about one-quarter wavelength (Urick, 1983; Rogers and
Cox, 1988).
Wardle et al. (2001) suggested that in water, acute injury and
death of organisms exposed to seismic energy depends primarily on two
features of the sound source: (1) The received peak pressure and (2)
the time required for the pressure to rise and decay. Generally, as
received pressure increases, the period for the pressure to rise and
decay decreases, and the chance of acute pathological effects
increases. According to Buchanan et al. (2004), for the types of
seismic airguns and arrays involved with the proposed program, the
pathological (mortality) zone for fish would be expected to be within a
few meters of the seismic source. Numerous other studies provide
examples of no fish mortality upon exposure to seismic sources (Falk
and Lawrence, 1973; Holliday et al., 1987; La Bella et al., 1996;
Santulli et al., 1999; McCauley et al., 2000a,b, 2003; Bjarti, 2002;
Thomsen, 2002; Hassel et al., 2003; Popper et al., 2005; Boeger et al.,
2006).
The National Park Service conducted an experiment of the effects of
a single 700 in\3\ airgun in Lake Meade, Nevada (USGS, 1999) to
understand the effects of a marine reflection survey of the Lake Meade
fault system (Paulson et al., 1993, in USGS, 1999). The researchers
suspended the airgun 3.5 m (11.5 ft) above a school of threadfin shad
in Lake Meade and fired three successive times at a 30 second interval.
Neither surface inspection nor diver observations of the water column
and bottom found any dead fish.
For a proposed seismic survey in Southern California, USGS (1999)
conducted a review of the literature on the effects of airguns on fish
and fisheries. They reported a 1991 study of the Bay Area Fault system
from the continental shelf to the Sacramento River, using a 10 airgun
(5,828 in\3\) array. Brezzina and Associates, hired by USGS to monitor
the effects of the surveys, concluded that airgun operations were not
responsible for the death of any of the fish carcasses observed, and
the airgun profiling did not appear to alter the feeding behavior of
sea lions, seals, or pelicans observed feeding during the seismic
surveys.
Some studies have reported, some equivocally, that mortality of
fish, fish eggs, or larvae can occur close to seismic sources
(Kostyuchenko, 1973; Dalen and Knutsen, 1986; Booman et al., 1996;
Dalen et al., 1996). Some of the reports claimed seismic effects from
treatments quite different from actual seismic survey sounds or even
reasonable surrogates. However, Payne et al. (2009) reported no
statistical differences in mortality/morbidity between control and
exposed groups of capelin eggs or monkfish larvae. Saetre and Ona
(1996) applied a worst-case scenario, mathematical model to investigate
the effects of seismic energy on fish eggs and larvae. They concluded
that mortality rates caused by exposure to seismic surveys are so low,
as compared to natural mortality rates, that the impact of seismic
surveying on recruitment to a fish stock must be regarded as
insignificant.
Physiological Effects--Physiological effects refer to cellular and/
or biochemical responses of fish to acoustic stress. Such stress
potentially could affect fish populations by increasing mortality or
reducing reproductive success. Primary and secondary stress responses
of fish after exposure to seismic survey sound appear to be temporary
in all studies done to date (Sverdrup et al., 1994; Santulli et al.,
1999; McCauley et al.,
[[Page 14795]]
2000a,b). The periods necessary for the biochemical changes to return
to normal are variable and depend on numerous aspects of the biology of
the species and of the sound stimulus.
Behavioral Effects--Behavioral effects include changes in the
distribution, migration, mating, and catchability of fish populations.
Studies investigating the possible effects of sound (including seismic
survey sound) on fish behavior have been conducted on both uncaged and
caged individuals (e.g., Chapman and Hawkins, 1969; Pearson et al.,
1992; Santulli et al., 1999; Wardle et al., 2001; Hassel et al., 2003).
Typically, in these studies fish exhibited a sharp startle response at
the onset of a sound followed by habituation and a return to normal
behavior after the sound ceased.
The Minerals Management Service (MMS, 2005) assessed the effects of
a proposed seismic survey in Cook Inlet, Alaska. The seismic survey
proposed using three vessels, each towing two, four-airgun arrays
ranging from 1,500 to 2,500 in\3\. The Minerals Management Service
noted that the impact to fish populations in the survey area and
adjacent waters would likely be very low and temporary and also
concluded that seismic surveys may displace the pelagic fishes from the
area temporarily when airguns are in use. However, fishes displaced and
avoiding the airgun noise are likely to backfill the survey area in
minutes to hours after cessation of seismic testing. Fishes not
dispersing from the airgun noise (e.g., demersal species) may startle
and move short distances to avoid airgun emissions.
In general, any adverse effects on fish behavior or fisheries
attributable to seismic testing may depend on the species in question
and the nature of the fishery (season, duration, fishing method). They
may also depend on the age of the fish, its motivational state, its
size, and numerous other factors that are difficult, if not impossible,
to quantify at this point, given such limited data on effects of
airguns on fish, particularly under realistic at-sea conditions.
Anticipated Effects on Invertebrates
The existing body of information on the impacts of seismic survey
sound on marine invertebrates is very limited. However, there is some
unpublished and very limited evidence of the potential for adverse
effects on invertebrates, thereby justifying further discussion and
analysis of this issue. The three types of potential effects of
exposure to seismic surveys on marine invertebrates are pathological,
physiological, and behavioral. Based on the physical structure of their
sensory organs, marine invertebrates appear to be specialized to
respond to particle displacement components of an impinging sound field
and not to the pressure component (Popper et al., 2001).
The only information available on the impacts of seismic surveys on
marine invertebrates involves studies of individuals; there have been
no studies at the population scale. Thus, available information
provides limited insight on possible real-world effects at the regional
or ocean scale. The most important aspect of potential impacts concerns
how exposure to seismic survey sound ultimately affects invertebrate
populations and their viability, including availability to fisheries.
Moriyasu et al. (2004) and Payne et al. (2008) provide literature
reviews of the effects of seismic and other underwater sound on
invertebrates. The following sections provide a synopsis of available
information on the effects of exposure to seismic survey sound on
species of decapod crustaceans and cephalopods, the two taxonomic
groups of invertebrates on which most such studies have been conducted.
The available information is from studies with variable degrees of
scientific soundness and from anecdotal information. A more detailed
review of the literature on the effects of seismic survey sound on
invertebrates is in Appendix E of the 2011 PEIS (NSF/USGS, 2011).
Pathological Effects--In water, lethal and sub-lethal injury to
organisms exposed to seismic survey sound appears to depend on at least
two features of the sound source: (1) The received peak pressure; and
(2) the time required for the pressure to rise and decay. Generally, as
received pressure increases, the period for the pressure to rise and
decay decreases, and the chance of acute pathological effects
increases. For the type of airgun array planned for the proposed
program, the pathological (mortality) zone for crustaceans and
cephalopods is expected to be within a few meters of the seismic
source, at most; however, very few specific data are available on
levels of seismic signals that might damage these animals. This premise
is based on the peak pressure and rise/decay time characteristics of
seismic airgun arrays currently in use around the world.
Some studies have suggested that seismic survey sound has a limited
pathological impact on early developmental stages of crustaceans
(Pearson et al., 1994; Christian et al., 2003; DFO, 2004). However, the
impacts appear to be either temporary or insignificant compared to what
occurs under natural conditions. Controlled field experiments on adult
crustaceans (Christian et al., 2003, 2004; DFO, 2004) and adult
cephalopods (McCauley et al., 2000a,b) exposed to seismic survey sound
have not resulted in any significant pathological impacts on the
animals. It has been suggested that exposure to commercial seismic
survey activities has injured giant squid (Guerra et al., 2004), but
the article provides little evidence to support this claim.
Tenera Environmental (2011b) reported that Norris and Mohl (1983,
summarized in Mariyasu et al., 2004) observed lethal effects in squid
(Loligo vulgaris) at levels of 246 to 252 dB after 3 to 11 minutes.
Andre et al. (2011) exposed four cephalopod species (Loligo
vulgaris, Sepia officinalis, Octopus vulgaris, and Ilex coindetii) to
two hours of continuous sound from 50 to 400 Hz at 157 5
dB re: 1 [mu]Pa. They reported lesions to the sensory hair cells of the
statocysts of the exposed animals that increased in severity with time,
suggesting that cephalopods are particularly sensitive to low-frequency
sound. The received sound pressure level was 157 5 dB re:
1 [micro]Pa, with peak levels at 175 dB re 1 [micro]Pa. As in the
McCauley et al. (2003) paper on sensory hair cell damage in pink
snapper as a result of exposure to seismic sound, the cephalopods were
subjected to higher sound levels than they would be under natural
conditions, and they were unable to swim away from the sound source.
Physiological Effects--Physiological effects refer mainly to
biochemical responses by marine invertebrates to acoustic stress. Such
stress potentially could affect invertebrate populations by increasing
mortality or reducing reproductive success. Studies have noted primary
and secondary stress responses (i.e., changes in haemolymph levels of
enzymes, proteins, etc.) of crustaceans occurring several days or
months after exposure to seismic survey sounds (Payne et al., 2007).
The authors noted that crustaceans exhibited no behavioral impacts
(Christian et al., 2003, 2004; DFO, 2004). The periods necessary for
these biochemical changes to return to normal are variable and depend
on numerous aspects of the biology of the species and of the sound
stimulus.
Behavioral Effects--There is increasing interest in assessing the
possible direct and indirect effects of seismic and other sounds on
invertebrate behavior, particularly in relation to the consequences for
[[Page 14796]]
fisheries. Changes in behavior could potentially affect such aspects as
reproductive success, distribution, susceptibility to predation, and
catchability by fisheries. Studies investigating the possible
behavioral effects of exposure to seismic survey sound on crustaceans
and cephalopods have been conducted on both uncaged and caged animals.
In some cases, invertebrates exhibited startle responses (e.g., squid
in McCauley et al., 2000a,b). In other cases, the authors observed no
behavioral impacts (e.g., crustaceans in Christian et al., 2003, 2004;
DFO, 2004). There have been anecdotal reports of reduced catch rates of
shrimp shortly after exposure to seismic surveys; however, other
studies have not observed any significant changes in shrimp catch rate
(Andriguetto-Filho et al., 2005). Similarly, Parry and Gason (2006) did
not find any evidence that lobster catch rates were affected by seismic
surveys. Any adverse effects on crustacean and cephalopod behavior or
fisheries attributable to seismic survey sound depend on the species in
question and the nature of the fishery (season, duration, fishing
method).
Based on the preceding discussion, NMFS does not anticipate that
the proposed activity would have any habitat-related effects that could
cause significant or long-term consequences for individual marine
mammals or their populations.
Proposed Mitigation
In order to issue an incidental take authorization under section
101(a)(5)(D) of the MMPA, NMFS must set forth the permissible methods
of taking pursuant to such activity, and other means of effecting the
least practicable adverse impact on such species or stock and its
habitat, paying particular attention to rookeries, mating grounds, and
areas of similar significance, and on the availability of such species
or stock for taking for certain subsistence uses (where relevant).
The Observatory has reviewed the following source documents and has
incorporated a suite of proposed mitigation measures into their project
description.
(1) Protocols used during previous Foundation and Observatory-
funded seismic research cruises as approved by us and detailed in the
Foundation's 2011 PEIS and 2013 EA;
(2) Previous incidental harassment authorizations applications and
authorizations that we have approved and authorized; and
(3) Recommended best practices in Richardson et al. (1995), Pierson
et al. (1998), and Weir and Dolman, (2007).
To reduce the potential for disturbance from acoustic stimuli
associated with the activities, the Observatory, and/or its designees
have proposed to implement the following mitigation measures for marine
mammals:
(1) Vessel-based visual mitigation monitoring;
(2) Proposed exclusion zones;
(3) Power down procedures;
(4) Shutdown procedures;
(5) Ramp-up procedures; and
(6) Speed and course alterations.
Vessel-Based Visual Mitigation Monitoring
The Observatory would position observers aboard the seismic source
vessel to watch for marine mammals near the vessel during daytime
airgun operations and during any start-ups at night. Observers would
also watch for marine mammals near the seismic vessel for at least 30
minutes prior to the start of airgun operations after an extended
shutdown (i.e., greater than approximately eight minutes for this
proposed cruise). When feasible, the observers would conduct
observations during daytime periods when the seismic system is not
operating for comparison of sighting rates and behavior with and
without airgun operations and between acquisition periods. Based on the
observations, the Langseth would power down or shutdown the airguns
when marine mammals are observed within or about to enter a designated
180-dB or 190-dB exclusion zone.
During seismic operations, at least four protected species
observers would be aboard the Langseth. The Observatory would appoint
the observers with our concurrence and they would conduct observations
during ongoing daytime operations and nighttime ramp-ups of the airgun
array. During the majority of seismic operations, two observers would
be on duty from the observation tower to monitor marine mammals near
the seismic vessel. Using two observers would increase the
effectiveness of detecting animals near the source vessel. However,
during mealtimes and bathroom breaks, it is sometimes difficult to have
two observers on effort, but at least one observer would be on watch
during bathroom breaks and mealtimes. Observers would be on duty in
shifts of no longer than four hours in duration.
Two observers on the Langseth would also be on visual watch during
all nighttime ramp-ups of the seismic airguns. A third observer would
monitor the passive acoustic monitoring equipment 24 hours a day to
detect vocalizing marine mammals present in the action area. In
summary, a typical daytime cruise would have scheduled two observers
(visual) on duty from the observation tower, and an observer (acoustic)
on the passive acoustic monitoring system. Before the start of the
seismic survey, the Observatory would instruct the vessel's crew to
assist in detecting marine mammals and implementing mitigation
requirements.
The Langseth is a suitable platform for marine mammal observations.
When stationed on the observation platform, the eye level would be
approximately 21.5 m (70.5 ft) above sea level, and the observer would
have a good view around the entire vessel. During daytime, the
observers would scan the area around the vessel systematically with
reticle binoculars (e.g., 7 x 50 Fujinon), Big-eye binoculars (25 x
150), and with the naked eye. During darkness, night vision devices
would be available (ITT F500 Series Generation 3 binocular-image
intensifier or equivalent), when required. Laser range-finding
binoculars (Leica LRF 1200 laser rangefinder or equivalent) would be
available to assist with distance estimation. They are useful in
training observers to estimate distances visually, but are generally
not useful in measuring distances to animals directly. The user
measures distances to animals with the reticles in the binoculars.
When the observers see marine mammals within or about to enter the
designated exclusion zone, the Langseth would immediately power down or
shutdown the airguns. The observer(s) would continue to maintain watch
to determine when the animal(s) are outside the exclusion zone by
visual confirmation. Airgun operations would not resume until the
observer has confirmed that the animal has left the zone, or if not
observed after 15 minutes for species with shorter dive durations
(small odontocetes and pinnipeds) or 30 minutes for species with longer
dive durations (mysticetes and large odontocetes, including sperm,
pygmy sperm, dwarf sperm, killer, and beaked whales).
Proposed Exclusion Zones: The Observatory would use safety radii to
designate exclusion zones and to estimate take for marine mammals.
Table 3 shows the distances at which one would expect to receive sound
levels (160-, 180-, or 190-dB) from the airgun subarrays and a single
airgun.
[[Page 14797]]
Table 3--Modeled Distances to Which Sound Levels Greater Than or Equal to 160 and 180 dB re: 1 [mu]Pa Could Be
Received During the Proposed Survey Offshore New Jersey in the North Atlantic Ocean, May Through August 2014
----------------------------------------------------------------------------------------------------------------
Predicted RMS distances \1\ (m)
Source and volume (in\3\) Tow depth (m) Water depth -----------------------------------------------
(m) 190 dB \2\ 180 dB 160 dB
----------------------------------------------------------------------------------------------------------------
Single Bolt airgun (40-in\3\)... 6 <100 21 100 995
4-Airgun subarray (700-in\3\)... 4.5 <100 101 378 5,240
4-Airgun subarray (700-in\3\)... 6 <100 118 439 6,100
8-Airgun subarray (1,400-in\3\). 4.5 <100 128 478 6,670
8-Airgun subarray (1,400-in\3\). 6 <100 157 585 8,150
----------------------------------------------------------------------------------------------------------------
\1\ Predicted distances based on Table 1 of the Foundation's application.
\2\ The Observatory did not request take for pinniped species in their application and consequently did not
include distances for the 190-dB isopleth for pinnipeds in Table 1 of their application. Because NMFS
anticipates that pinnipeds have the potential to occur in the survey area, the Observatory calculated the
distances for the 190-dB isopleth and submitted them to NMFS on February 28, 2014 for inclusion in this table.
The 180- or 190-dB level shutdown criteria are applicable to
cetaceans as specified by NMFS (2000). The Observatory used these
levels to establish the exclusion zones.
If the protected species visual observer detects marine mammal(s)
within or about to enter the appropriate exclusion zone, the Langseth
crew would immediately power down the airgun array, or perform a
shutdown if necessary (see Shut-down Procedures).
Power Down Procedures--A power down involves decreasing the number
of airguns in use such that the radius of the 180- or 190-dB zone is
smaller to the extent that marine mammals are no longer within or about
to enter the exclusion zone. A power down of the airgun array can also
occur when the vessel is moving from one seismic line to another.
During a power down for mitigation, the Langseth would operate one
airgun (40 in\3\). The continued operation of one airgun would alert
marine mammals to the presence of the seismic vessel in the area. A
shutdown occurs when the Langseth suspends all airgun activity.
If the observer detects a marine mammal outside the exclusion zone
and the animal is likely to enter the zone, the crew would power down
the airguns to reduce the size of the 180- or 190-dB exclusion zone
before the animal enters that zone. Likewise, if a mammal is already
within the zone after detection, the crew would power-down the airguns
immediately. During a power down of the airgun array, the crew would
operate a single 40-in\3\ airgun which has a smaller exclusion zone. If
the observer detects a marine mammal within or near the smaller
exclusion zone around the airgun (Table 3), the crew would shut down
the single airgun (see next section).
Resuming Airgun Operations After a Power Down--Following a power-
down, the Langseth crew would not resume full airgun activity until the
marine mammal has cleared the 180- or 190-dB exclusion zone (see Table
3). The observers would consider the animal to have cleared the
exclusion zone if:
The observer has visually observed the animal leave the
exclusion zone; or
An observer has not sighted the animal within the
exclusion zone for 15 minutes for species with shorter dive durations
(i.e., small odontocetes or pinnipeds), or 30 minutes for species with
longer dive durations (i.e., mysticetes and large odontocetes,
including sperm, pygmy sperm, dwarf sperm, and beaked whales); or
The Langseth crew would resume operating the airguns at full power
after 15 minutes of sighting any species with short dive durations
(i.e., small odontocetes or pinnipeds). Likewise, the crew would resume
airgun operations at full power after 30 minutes of sighting any
species with longer dive durations (i.e., mysticetes and large
odontocetes, including sperm, pygmy sperm, dwarf sperm, and beaked
whales).
We estimate that the Langseth would transit outside the original
180- or 190-dB exclusion zone after an 8-minute wait period. This
period is based on the 180- or 190-dB exclusion zone for the airgun
subarray towed at a depth of 12 m (39.4 ft) in relation to the average
speed of the Langseth while operating the airguns (8.5 km/h; 5.3 mph).
Because the vessel has transited away from the vicinity of the original
sighting during the 8-minute period, implementing ramp-up procedures
for the full array after an extended power down (i.e., transiting for
an additional 35 minutes from the location of initial sighting) would
not meaningfully increase the effectiveness of observing marine mammals
approaching or entering the exclusion zone for the full source level
and would not further minimize the potential for take. The Langseth's
observers are continually monitoring the exclusion zone for the full
source level while the mitigation airgun is firing. On average,
observers can observe to the horizon (10 km; 6.2 mi) from the height of
the Langseth's observation deck and should be able to say with a
reasonable degree of confidence whether a marine mammal would be
encountered within this distance before resuming airgun operations at
full power.
Shutdown Procedures--The Langseth crew would shutdown the operating
airgun(s) if they see a marine mammal within or approaching the
exclusion zone for the single airgun. The crew would implement a
shutdown:
(1) If an animal enters the exclusion zone of the single airgun
after the crew has initiated a power down; or
(2) If an observer sees the animal is initially within the
exclusion zone of the single airgun when more than one airgun
(typically the full airgun array) is operating.
Considering the conservation status for north Atlantic right
whales, the Langseth crew would shutdown the airgun(s) immediately in
the unlikely event that observers detect this species, regardless of
the distance from the vessel. The Langseth would only begin ramp-up
would only if observers have not seen the north Atlantic right whale
for 30 minutes.
Resuming Airgun Operations After a Shutdown--Following a shutdown
in excess of eight minutes, the Langseth crew would initiate a ramp-up
with the smallest airgun in the array (40-in\3\). The crew would turn
on additional airguns in a sequence such that the source level of the
array would increase in steps not exceeding 6 dB per five-minute period
over a total duration of approximately 30 minutes. During ramp-up, the
observers would monitor the exclusion zone, and if he/she sees a marine
mammal, the Langseth crew would
[[Page 14798]]
implement a power down or shutdown as though the full airgun array were
operational.
During periods of active seismic operations, there are occasions
when the Langseth crew would need to temporarily shut down the airguns
due to equipment failure or for maintenance. In this case, if the
airguns are inactive longer than eight minutes, the crew would follow
ramp-up procedures for a shutdown described earlier and the observers
would monitor the full exclusion zone and would implement a power down
or shutdown if necessary.
If the full exclusion zone is not visible to the observer for at
least 30 minutes prior to the start of operations in either daylight or
nighttime, the Langseth crew would not commence ramp-up unless at least
one airgun (40-in\3\ or similar) has been operating during the
interruption of seismic survey operations. Given these provisions, it
is likely that the vessel's crew would not ramp up the airgun array
from a complete shutdown at night or in thick fog, because the outer
part of the zone for that array would not be visible during those
conditions.
If one airgun has operated during a power down period, ramp-up to
full power would be permissible at night or in poor visibility, on the
assumption that marine mammals would be alerted to the approaching
seismic vessel by the sounds from the single airgun and could move
away. The vessel's crew would not initiate a ramp-up of the airguns if
an observer sees the marine mammal within or near the applicable
exclusion zones during the day or close to the vessel at night.
Ramp-Up Procedures--Ramp-up of an airgun array provides a gradual
increase in sound levels, and involves a step-wise increase in the
number and total volume of airguns firing until the full volume of the
airgun array is achieved. The purpose of a ramp-up is to ``warn''
marine mammals in the vicinity of the airguns, and to provide the time
for them to leave the area and thus avoid any potential injury or
impairment of their hearing abilities. The Observatory would follow a
ramp-up procedure when the airgun array begins operating after an 8
minute period without airgun operations or when shut down has exceeded
that period. The Observatory has used similar waiting periods
(approximately eight to 10 minutes) during previous seismic surveys.
Ramp-up would begin with the smallest airgun in the array (40
in\3\). The crew would add airguns in a sequence such that the source
level of the array would increase in steps not exceeding six dB per
five minute period over a total duration of approximately 30 to 35
minutes. During ramp-up, the observers would monitor the exclusion
zone, and if marine mammals are sighted, the Observatory would
implement a power-down or shut-down as though the full airgun array
were operational.
If the complete exclusion zone has not been visible for at least 30
minutes prior to the start of operations in either daylight or
nighttime, the Observatory would not commence the ramp-up unless at
least one airgun (40 in\3\ or similar) has been operating during the
interruption of seismic survey operations. Given these provisions, it
is likely that the crew would not ramp up the airgun array from a
complete shut-down at night or in thick fog, because the outer part of
the exclusion zone for that array would not be visible during those
conditions. If one airgun has operated during a power-down period,
ramp-up to full power would be permissible at night or in poor
visibility, on the assumption that marine mammals would be alerted to
the approaching seismic vessel by the sounds from the single airgun and
could move away. The Observatory would not initiate a ramp-up of the
airguns if a marine mammal is sighted within or near the applicable
exclusion zones.
Speed and Course Alterations
If during seismic data collection, the Observatory detects marine
mammals outside the exclusion zone and, based on the animal's position
and direction of travel, is likely to enter the exclusion zone, the
Langseth would change speed and/or direction if this does not
compromise operational safety. Due to the limited maneuverability of
the primary survey vessel, altering speed and/or course can result in
an extended period of time to realign onto the transect. However, if
the animal(s) appear likely to enter the exclusion zone, the Langseth
would undertake further mitigation actions, including a power down or
shut down of the airguns.
Mitigation Conclusions
NMFS has carefully evaluated the Observatory's proposed mitigation
measures in the context of ensuring that we prescribe the means of
effecting the least practicable 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.
Any mitigation measure(s) prescribed by NMFS should be able to
accomplish, have a reasonable likelihood of accomplishing (based on
current science), or contribute to the accomplishment of one or more of
the general goals listed here:
1. Avoidance or minimization of injury or death of marine mammals
wherever possible (goals 2, 3, and 4 may contribute to this goal).
2. A reduction in the numbers of marine mammals (total number or
number at biologically important time or location) exposed to airgun
operations that we expect to result in the take of marine mammals (this
goal may contribute to 1, above, or to reducing harassment takes only).
3. A reduction in the number of times (total number or number at
biologically important time or location) individuals would be exposed
to airgun operations that we expect to result in the take of marine
mammals (this goal may contribute to 1, above, or to reducing
harassment takes only).
4. A reduction in the intensity of exposures (either total number
or number at biologically important time or location) to airgun
operations that we expect to result in the take of marine mammals (this
goal may contribute to a, above, or to reducing the severity of
harassment takes only).
5. Avoidance or minimization of adverse effects to marine mammal
habitat, paying special attention to the food base, activities that
block or limit passage to or from biologically important areas,
permanent destruction of habitat, or temporary destruction/disturbance
of habitat during a biologically important time.
6. For monitoring directly related to mitigation--an increase in
the probability of detecting marine mammals, thus allowing for more
effective implementation of the mitigation.
Based on the evaluation of the Observatory's proposed measures, as
well as other measures considered, NMFS has preliminarily determined
that the proposed mitigation measures provide the means of effecting
the least practicable impact on marine mammal species or stocks and
their habitat, paying particular attention to rookeries, mating
grounds, and areas of similar significance.
[[Page 14799]]
Proposed Monitoring
In order to issue an ITA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth ``requirements pertaining to
the monitoring and reporting of such taking''. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
Authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that we expect to be present in the
proposed action area.
The Observatory submitted a marine mammal monitoring plan in
section XIII of the Authorization application. NMFS or the Observatory
may modify or supplement the plan based on comments or new information
received from the public during the public comment period.
Monitoring measures prescribed by NMFS should accomplish one or
more of the following general goals:
1. An increase in the probability of detecting marine mammals, both
within the mitigation zone (thus allowing for more effective
implementation of the mitigation) and during other times and locations,
in order to generate more data to contribute to the analyses mentioned
later;
2. An increase in our understanding of how many marine mammals
would be affected by seismic airguns and other active acoustic sources
and the likelihood of associating those exposures with specific adverse
effects, such as behavioral harassment, temporary or permanent
threshold shift;
3. An increase in our understanding of how marine mammals respond
to stimuli that we expect to result in take and how those anticipated
adverse effects on individuals (in different ways and to varying
degrees) may impact the population, species, or stock (specifically
through effects on annual rates of recruitment or survival) through any
of the following methods:
a. Behavioral observations in the presence of stimuli compared to
observations in the absence of stimuli (i.e., we need to be able to
accurately predict received level, distance from source, and other
pertinent information);
b. Physiological measurements in the presence of stimuli compared
to observations in the absence of stimuli (i.e., we need to be able to
accurately predict received level, distance from source, and other
pertinent information);
c. Distribution and/or abundance comparisons in times or areas with
concentrated stimuli versus times or areas without stimuli;
4. An increased knowledge of the affected species; and
5. An increase in our understanding of the effectiveness of certain
mitigation and monitoring measures.
Proposed Monitoring Measures
The Observatory proposes to sponsor marine mammal monitoring during
the present project to supplement the mitigation measures that require
real-time monitoring, and to satisfy the monitoring requirements of the
Authorization. The Observatory understands that NMFS would review the
monitoring plan and may require refinements to the plan.
The Observatory planned the monitoring work as a self-contained
project independent of any other related monitoring projects that may
occur in the same regions at the same time. Further, the Observatory is
prepared to discuss coordination of its monitoring program with any
other related work that might be conducted by other groups working
insofar as it is practical for the Observatory.
Vessel-Based Passive Acoustic Monitoring
Passive acoustic monitoring would complement the visual mitigation
monitoring program, when practicable. Visual monitoring typically is
not effective during periods of poor visibility or at night, and even
with good visibility, is unable to detect marine mammals when they are
below the surface or beyond visual range. Passive acoustical monitoring
can improve detection, identification, and localization of cetaceans
when used in conjunction with visual observations. The passive acoustic
monitoring would serve to alert visual observers (if on duty) when
vocalizing cetaceans are detected. It is only useful when marine
mammals call, but it can be effective either by day or by night, and
does not depend on good visibility. The acoustic observer would monitor
the system in real time so that he/she can advise the visual observers
if they acoustic detect cetaceans.
The passive acoustic monitoring system consists of hardware (i.e.,
hydrophones) and software. The ``wet end'' of the system consists of a
towed hydrophone array connected to the vessel by a tow cable. The tow
cable is 250 m (820.2 ft) long and the hydrophones are fitted in the
last 10 m (32.8 ft) of cable. A depth gauge, attached to the free end
of the cable, which is typically towed at depths less than 20 m (65.6
ft). The Langseth crew would deploy the array from a winch located on
the back deck. A deck cable would connect the tow cable to the
electronics unit in the main computer lab where the acoustic station,
signal conditioning, and processing system would be located. The
Pamguard software amplifies, digitizes, and then processes the acoustic
signals received by the hydrophones. The system can detect marine
mammal vocalizations at frequencies up to 250 kHz.
One acoustic observer, an expert bioacoustician with primary
responsibility for the passive acoustic monitoring system would be
aboard the Langseth in addition to the four visual observers. The
acoustic observer would monitor the towed hydrophones 24 hours per day
during airgun operations and during most periods when the Langseth is
underway while the airguns are not operating. However, passive acoustic
monitoring may not be possible if damage occurs to both the primary and
back-up hydrophone arrays during operations. The primary passive
acoustic monitoring streamer on the Langseth is a digital hydrophone
streamer. Should the digital streamer fail, back-up systems should
include an analog spare streamer and a hull-mounted hydrophone.
One acoustic observer would monitor the acoustic detection system
by listening to the signals from two channels via headphones and/or
speakers and watching the real-time spectrographic display for
frequency ranges produced by cetaceans. The observer monitoring the
acoustical data would be on shift for one to six hours at a time. The
other observers would rotate as an acoustic observer, although the
expert acoustician would be on passive acoustic monitoring duty more
frequently.
When the acoustic observer detects a vocalization while visual
observations are in progress, the acoustic observer on duty would
contact the visual observer immediately, to alert him/her to the
presence of cetaceans (if they have not already been seen), so that the
vessel's crew can initiate a power down or shutdown, if required. The
observer would enter the information regarding the call into a
database. Data entry would include an acoustic encounter identification
number, whether it was linked with a visual sighting, date, time when
first and last heard and whenever any additional information was
recorded, position and water depth when first detected, bearing if
determinable, species or species group (e.g., unidentified dolphin,
sperm
[[Page 14800]]
whale), types and nature of sounds heard (e.g., clicks, continuous,
sporadic, whistles, creaks, burst pulses, strength of signal, etc.),
and any other notable information. Acousticians record the acoustic
detection for further analysis.
Observer Data and Documentation
Observers would record data to estimate the numbers of marine
mammals exposed to various received sound levels and to document
apparent disturbance reactions or lack thereof. They would use the data
to estimate numbers of animals potentially `taken' by harassment (as
defined in the MMPA). They will also provide information needed to
order a power down or shut down of the airguns when a marine mammal is
within or near the exclusion zone.
When an observer makes a sighting, they will record the following
information:
1. Species, group size, age/size/sex categories (if determinable),
behavior when first sighted and after initial sighting, heading (if
consistent), bearing and distance from seismic vessel, sighting cue,
apparent reaction to the airguns or vessel (e.g., none, avoidance,
approach, paralleling, etc.), and behavioral pace.
2. Time, location, heading, speed, activity of the vessel, sea
state, visibility, and sun glare.
The observer will record the data listed under (2) at the start and
end of each observation watch, and during a watch whenever there is a
change in one or more of the variables.
Observers will record all observations and power downs or shutdowns
in a standardized format and will enter data into an electronic
database. The observers will verify the accuracy of the data entry by
computerized data validity checks during data entry and by subsequent
manual checking of the database. These procedures will allow the
preparation of initial summaries of data during and shortly after the
field program, and will facilitate transfer of the data to statistical,
graphical, and other programs for further processing and archiving.
Results from the vessel-based observations will provide:
1. The basis for real-time mitigation (airgun power down or
shutdown).
2. Information needed to estimate the number of marine mammals
potentially taken by harassment, which the Observatory must report to
the Office of Protected Resources.
3. Data on the occurrence, distribution, and activities of marine
mammals and turtles in the area where the Observatory would conduct the
seismic study.
4. Information to compare the distance and distribution of marine
mammals and turtles relative to the source vessel at times with and
without seismic activity.
5. Data on the behavior and movement patterns of marine mammals
detected during non-active and active seismic operations.
Proposed Reporting
The Observatory would submit a report to us and to the Foundation
within 90 days after the end of the cruise. The report would describe
the operations conducted and sightings of marine mammals and turtles
near the operations. The report would provide full documentation of
methods, results, and interpretation pertaining to all monitoring. The
90-day report would summarize the dates and locations of seismic
operations, and all marine mammal sightings (dates, times, locations,
activities, associated seismic survey activities). The report would
also include estimates of the number and nature of exposures that could
result in ``takes'' of marine mammals by harassment or in other ways.
In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner not permitted by the
authorization (if issued), such as an injury, serious injury, or
mortality (e.g., ship-strike, gear interaction, and/or entanglement),
the Observatory shall immediately cease the specified activities and
immediately report the take to the Incidental Take Program Supervisor,
Permits and Conservation Division, Office of Protected Resources, NMFS,
at 301-427-8401 and/or by email to [email protected] and
[email protected] and the Northeast Regional Stranding Coordinator at
(978) 281-9300. 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).
The Observatory shall not resume its activities until we are able
to review the circumstances of the prohibited take. We shall work with
the Observatory to determine what is necessary to minimize the
likelihood of further prohibited take and ensure MMPA compliance. The
Observatory may not resume their activities until notified by us via
letter, email, or telephone.
In the event that the Observatory discovers an injured or dead
marine mammal, and the lead visual observer 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 we describe in
the next paragraph), the Observatory will immediately report the
incident to the Incidental Take Program Supervisor, Permits and
Conservation Division, Office of Protected Resources, NMFS, at 301-427-
8401 and/or by email to [email protected] and [email protected]
and the Northeast Regional Stranding Coordinator at (978) 281-9300. The
report must include the same information identified in the paragraph
above this section. Activities may continue while NMFS reviews the
circumstances of the incident. NMFS would work with the Observatory to
determine whether modifications in the activities are appropriate.
In the event that the Observatory discovers an injured or dead
marine mammal, and the lead visual observer determines that the injury
or death is not associated with or related to the authorized activities
(e.g., previously wounded animal, carcass with moderate to advanced
decomposition, or scavenger damage), the Observatory would report the
incident to the Incidental Take Program Supervisor, Permits and
Conservation Division, Office of Protected Resources, NMFS, at 301-427-
8401 and/or by email to [email protected] and [email protected]
and the Northeast Regional Stranding Coordinator at (978) 281-9300,
within 24 hours of the discovery. The Observatory would provide
photographs or video footage (if available) or other documentation of
the stranded animal sighting to NMFS.
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
[[Page 14801]]
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].
Acoustic stimuli (i.e., increased underwater sound) generated
during the operation of the airgun sub-arrays may have the potential to
result in the behavioral disturbance of some marine mammals. Thus, NMFS
proposes to authorize take by Level B harassment resulting from the
operation of the sound sources for the proposed seismic survey based
upon the current acoustic exposure criteria shown in Table 4. Our
practice has been to apply the 160 dB re: 1 [micro]Pa received level
threshold for underwater impulse sound levels to determine whether take
by Level B harassment occurs. Southall et al. (2007) provides a
severity scale for ranking observed behavioral responses of both free-
ranging marine mammals and laboratory subjects to various types of
anthropogenic sound (see Table 4 in Southall et al. [2007]).
Table 4--NMFS' Current Acoustic Exposure Criteria
------------------------------------------------------------------------
Criterion
Criterion definition Threshold
------------------------------------------------------------------------
Level A Harassment (Injury)..... Permanent 180 dB re 1
Threshold Shift microPa-m
(PTS) (Any level (cetaceans)/190
above that which dB re 1 microPa-m
is known to cause (pinnipeds) root
TTS). mean square
(rms).
Level B Harassment.............. Behavioral 160 dB re 1
Disruption (for microPa-m (rms).
impulse noises).
------------------------------------------------------------------------
The probability of vessel and marine mammal interactions (i.e.,
ship strike) occurring during the proposed survey is unlikely due to
the Langseth's slow operational speed, which is typically 4.6 kts (8.5
km/h; 5.3 mph). Outside of seismic operations, the Langseth's cruising
speed would be approximately 11.5 mph (18.5 km/h; 10 kts) which is
generally below the speed at which studies have noted reported
increases of marine mammal injury or death (Laist et al., 2001). In
addition, the Langseth has a number of other advantages for avoiding
ship strikes as compared to most commercial merchant vessels, including
the following: The Langseth's bridge offers good visibility to visually
monitor for marine mammal presence; observers posted during operations
scan the ocean for marine mammals and must report visual alerts of
marine mammal presence to crew; and the observers receive extensive
training that covers the fundamentals of visual observing for marine
mammals and information about marine mammals and their identification
at sea. Thus, NMFS does not anticipate that take would result from the
movement of the vessel.
The Observatory did not estimate any additional take allowance for
animals that could be affected by sound sources other than the airgun.
NMFS does not expect that the sound levels produced by the echosounder,
sub-bottom profiler, and ADCP would exceed by the sound levels produced
by the airguns for the majority of the time. Because of the beam
pattern and directionality of these sources, combined with their lower
source levels, it is not likely that these sources would take marine
mammals independently from the takes that the Observatory has estimated
to result from airgun operations. Therefore, NMFS does not believe it
is necessary to authorize additional takes for these sources for the
action at this time. NMFS is currently evaluating the broader use of
these types of sources to determine under what specific circumstances
coverage for incidental take would or would not be advisable. NMFS is
working on guidance that would outline a consistent recommended
approach for applicants to address the potential impacts of these types
of sources.
NMFS considers the probability for entanglement of marine mammals
as low because of the vessel speed and the monitoring efforts onboard
the survey vessel. Therefore, NMFS does not believe it is necessary to
authorize additional takes for entanglement at this time.
There is no evidence that planned activities could result in
serious injury or mortality within the specified geographic area for
the requested Authorization. The required mitigation and monitoring
measures would minimize any potential risk for serious injury or
mortality.
The following sections describe the Observatory's methods to
estimate take by incidental harassment. The Observatory based their
estimates on the number of marine mammals that could be harassed by
seismic operations with the airgun sub-array during approximately 4,900
km\2\ (approximately 1,926.6 square miles (mi\2\) of transect lines in
the northwest Atlantic Ocean as depicted in Figure 1 (Figure 1 of the
Observatory's application).
Ensonified Area Calculations: In order to estimate the potential
number of marine mammals exposed to airgun sounds, the Observatory
considers the total marine area within the 160-dB radius around the
operating airguns. This ensonified area includes areas of overlapping
transect lines. They determine the ensonified area by entering the
planned survey lines into a MapInfo GIS, using the software to identify
the relevant areas by ``drawing'' the applicable 160-dB buffer (see
Table 3; Table 1 in the application) around each seismic line, and then
calculating the total area within the buffers.
Because the Observatory assumes that the Langseth may need to
repeat some tracklines, accommodate the turning of the vessel, address
equipment malfunctions, or conduct equipment testing to complete the
survey; they have increased the proposed number of line-kilometers for
the seismic operations from approximately 2,002 km (1,244 mi) by 25
percent to 2,502 km (1,555 mi) to account for these contingency
operations.
Exposure Estimates: The Observatory calculates the numbers of
different individuals potentially exposed to approximately 160 dB re: 1
[micro]Parms by multiplying the expected species density
estimates (in number/km\2\) for that area in the absence of a seismic
program times the estimated area of ensonification (i.e., 2,502 km;
1,555 mi).
Table 3 of their application presents their estimates of the number
of different individual marine mammals that could potentially
experience exposures greater than or equal to 160 dB re: 1 [mu]Pa (rms)
during the seismic survey if no animals moved away from the survey
vessel. The Observatory used the Strategic Environmental Research and
Development Program's (SERDP) spatial decision support system (SDSS)
Marine Animal Model Mapper tool (Read et al. 2009) to calculate
cetacean densities within the survey area based on the U.S. Navy's
``OPAREA Density Estimates'' (NODE) model (DoN, 2007). The NODE model
derives density estimates using density surface modeling of the
existing line-transect
[[Page 14802]]
data, which uses sea surface temperature, chlorophyll a, depth,
longitude, and latitude to allow extrapolation to areas/seasons where
marine mammal survey data collection did not occur. The Observatory
used the SERDP SDSS tool to obtain mean densities in a polygon the size
of the seismic survey area for 19 cetacean species during summer (June
through August).
For the proposed Authorization, NMFS has reviewed the Observatory's
take estimates presented in Table 3 of their application and has
revised take calculations for several species based upon the best
available density information from SERDP SDSS and other sources. These
include takes for blue, fin, humpback, minke, north Atlantic right, and
sei whales; harbor porpoise; and gray, harbor, and harp seals. Table 5
presents the revised estimates of the possible numbers of marine
mammals exposed to sound levels greater than or equal to 160 dB re: 1
[mu]Pa during the proposed seismic survey.
Table 5--Densities and Estimates of the Possible Numbers of Marine Mammals Exposed to Sound Levels Greater Than
or Equal to 160 dB re: 1 [mu]Pa During the Proposed Seismic Survey in the North Atlantic Ocean, During May
Through August 2014
----------------------------------------------------------------------------------------------------------------
Est. number of
individuals Proposed take Percent of
Species Density exposed to authorization species or stock Population
estimate \1\ sound levels \2\ \3\ trend \3\
>= 160 dB
----------------------------------------------------------------------------------------------------------------
North Atlantic right whale... \4\ 0.283 1 3 0.23............ Increasing.
Humpback whale............... \5\ 0.154 1 2 0.12............ Increasing.
Common minke whale........... 0 0 2 Unknown......... No data.
Sei whale.................... 0.161 1 2 0.28............ No data.
Fin whale.................... 0.002 1 2 0.03............ No data.
Blue whale................... \6\ 6.74 17 17 3.86............ No data.
Sperm whale.................. 7.06 18 18 1.13............ No data.
Dwarf sperm whale............ 0.001 2 2 0.19............ No data.
Pygmy sperm whale............ 0.001 2 2 0.27............ No data.
Cuvier's beaked whale........ 0.124 3 3 0.06............ No data.
Gervais' beaked whale........ 0.124 3 3 0.16............ No data.
Sowerby's beaked whale....... 0.124 3 3 0.08............ No data.
Unidentified Mesoplodon: 0.124 1 3 0.45............ No data.
True's, Blainville, northern
bottlenose whale.
Rough-toothed dolphin........ 0 0 0 0.00............ No data.
Bottlenose dolphin (pelagic). 111.3 279 279 0.34............ No data.
Bottlenose dolphin (coastal). 111.3 .............. .............. 2.91............ No data.
Pantropical spotted dolphin.. 0 0 0 0.00............ No data.
Atlantic spotted dolphin..... 36.1 90 90 0.34............ No data.
Spinner dolphin.............. 0 0 0 0.00............ No data.
Striped dolphin.............. 0 0 47 0.10............ No data.
Short-beaked common dolphin.. 0 0 18 0.03............ No data.
White-beaked dolphin......... 0 0 0 0.00............ No data.
Atlantic white-sided dolphin. 0 0 15 0.03............ No data.
Risso's dolphin.............. 13.6 35 35 0.23............ No data.
False killer whale........... 0 0 0 0.00............ No data
Pygmy killer whale........... 0 0 0 0.00............ No data.
Killer whale................. 0 0 0 0.00............ No data.
Long-finned pilot whale...... 0.184 1 9 0.07............ No data.
Short-finned pilot whale..... 0.184 1 9 0.04............ No data.
Harbor porpoise.............. \4\ 0.009 1 2 0.001........... No data.
Gray seal.................... No data 0 12 0.003........... Increasing.
Harbor seal.................. \4\ 44.43 112 112 0.11............ No data.
Harp seal.................... No data 0 4 0.00005......... Increasing.
----------------------------------------------------------------------------------------------------------------
\1\ Except where noted, densities are the mean values for the survey area calculated from the SERDP SDSS NODES
summer model (Read et al., 2009) as presented in Table 3 of the Observatory's application.
\2\ Proposed take includes increases for mean group size or cow/calf pairs based on Palka, 2012; NJDEP, 2010; or
increases for gray and harp seals based on stranding data from the NJ Marine Mammal Stranding Center.
\3\ Table 1 in this notice lists the stock species abundance estimates used in calculating the percentage of
species/stock. Population trend information from Waring et al., 2012. No data = Insufficient data to determine
population trend.
\4\ NMFS revised estimate based on the NODES model using the spring mean density estimate for that species in
survey area.
\5\ NMFS revised estimate based on the SERDP SDSS Duke Habitat Model using the summer mean density estimate for
humpback whales in survey area.
\6\ NMFS revised estimate based on the SERDP SDSS Duke Habitat Model using the summer mean density estimate for
baleen whales in survey area.
Encouraging and Coordinating Research
The Observatory would coordinate the planned marine mammal
monitoring program associated with the seismic survey in the northwest
Atlantic Ocean with applicable U.S. agencies.
Analysis and Preliminary Determinations
Negligible Impact
Negligible impact' is ``an impact resulting from the specified
activity that
[[Page 14803]]
cannot be reasonably expected to, and is not reasonably likely to,
adversely affect the species or stock through effects on annual rates
of recruitment or survival'' (50 CFR 216.103). The lack of likely
adverse effects on annual rates of recruitment or survival (i.e.,
population level effects) forms the basis of a negligible impact
finding. Thus, an estimate of the number of Level B harassment takes,
alone, is not enough information on which to base an impact
determination. In addition to considering estimates of the number of
marine mammals that might be ``taken'' through behavioral harassment,
NMFS must consider other factors, such as the likely nature of any
responses (their intensity, duration, etc.), the context of any
responses (critical reproductive time or location, migration, etc.), as
well as the number and nature of estimated Level A harassment takes,
and the number of estimated mortalities, effects on habitat, and the
status of the species.
In making a negligible impact determination, NMFS considers:
The number of anticipated injuries, serious injuries, or
mortalities;
The number, nature, and intensity, and duration of Level B
harassment; and
The context in which the takes occur (e.g., impacts to
areas of significance, impacts to local populations, and cumulative
impacts when taking into account successive/contemporaneous actions
when added to baseline data);
The status of stock or species of marine mammals (i.e.,
depleted, not depleted, decreasing, increasing, stable, impact relative
to the size of the population);
Impacts on habitat affecting rates of recruitment/
survival; and
The effectiveness of monitoring and mitigation measures to
reduce the number or severity of incidental take.
For reasons stated previously in this document and based on the
following factors, the Observatory's specified activities are not
likely to cause long-term behavioral disturbance, permanent threshold
shift, or other non-auditory injury, serious injury, or death. They
include:
The likelihood that, given sufficient notice through
relatively slow ship speed, we expect marine mammals to move away from
a noise source that is annoying prior to its becoming potentially
injurious;
The availability of alternate areas of similar habitat
value for marine mammals to temporarily vacate the survey area during
the operation of the airgun(s) to avoid acoustic harassment;
The relatively low potential for temporary or permanent
hearing impairment and the likelihood that the Observatory would avoid
this impact through the incorporation of the required monitoring and
mitigation measures (including power-downs and shutdowns); and
The likelihood that marine mammal detection ability by
trained visual observers is high at close proximity to the vessel.
NMFS does not anticipate that any injuries, serious injuries, or
mortalities would occur as a result of the Observatory's proposed
activities, and NMFS does not propose to authorize injury, serious
injury, or mortality at this time. We anticipate only behavioral
disturbance to occur during the conduct of the survey activities.
Table 5 in this document outlines the number of requested Level B
harassment takes that we anticipate as a result of these activities.
NMFS anticipates that 26 marine mammal species (6 mysticetes, 17
odontocetes, and 3 pinnipeds) would likely occur in the proposed action
area. Of the 24 marine mammal species under our jurisdiction that are
known to occur or likely to occur in the study area, six of these
species are listed as endangered under the ESA and depleted under the
MMPA, including: The blue, fin, humpback, north Atlantic right, sei,
and sperm whales.
Due to the nature, degree, and context of Level B (behavioral)
harassment anticipated and described (see ``Potential Effects on Marine
Mammals'' section in this notice), we do not expect the activity to
impact rates of recruitment or survival for any affected species or
stock. In addition, the seismic surveys would not take place in areas
of significance for marine mammal feeding, resting, breeding, or
calving and would not adversely impact marine mammal habitat.
Many animals perform vital functions, such as feeding, resting,
traveling, and socializing, on a diel cycle (i.e., 24 hour cycle).
Behavioral reactions to noise exposure (such as disruption of critical
life functions, displacement, or avoidance of important habitat) are
more likely to be significant if they last more than one diel cycle or
recur on subsequent days (Southall et al., 2007). While we anticipate
that the seismic operations would occur on consecutive days, the
estimated duration of the survey would last no more than 30 days.
Additionally, the seismic survey would increase sound levels in the
marine environment in a relatively small area surrounding the vessel
(compared to the range of the animals), which is constantly travelling
over distances, and some animals may only be exposed to and harassed by
sound for shorter less than day.
Based on this notice's analysis of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS preliminarily finds that the Observatory's
proposed seismic survey would have a negligible impact on the affected
marine mammal species or stocks.
Small Numbers
As mentioned previously, NMFS estimates that the Observatory's
activities could potentially affect, by Level B harassment only, 26
species of marine mammals under our jurisdiction. For each species,
these estimates are small numbers (each, less than or equal to four
percent) relative to the population size and we have provided the
regional population estimates for the marine mammal species that may be
taken by Level B harassment in Table 5 in this notice.
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 finds that the Observatory's proposed
activity would take small numbers of marine mammals relative to the
populations of the affected species or stocks.
Impact on Availability of Affected Species or Stock for Taking for
Subsistence Uses
There are no relevant subsistence uses of marine mammals implicated
by this action.
Endangered Species Act (ESA)
There are six marine mammal species that may occur in the proposed
survey area, several are listed as endangered under the Endangered
Species Act, including the blue, fin, humpback, north Atlantic right,
sei, and sperm whales. Under section 7 of the ESA, the Foundation has
initiated formal consultation with NMFS on the proposed seismic survey.
NMFS (i.e., National Marine Fisheries Service, Office of Protected
Resources, Permits and Conservation Division) will also consult
internally with NMFS on the proposed issuance of an Authorization under
section 101(a)(5)(D) of the MMPA. NMFS and the Foundation will conclude
the consultation prior to a determination on the issuance of the
Authorization.
[[Page 14804]]
National Environmental Policy Act (NEPA)
The Foundation has prepared a draft EA titled ``Draft Environmental
Assessment of a Marine Geophysical Survey by the R/V Marcus G. Langseth
in the Atlantic Ocean off New Jersey, June-July 2014.'' NMFS has posted
this draft EA on our Web site concurrently with the publication of this
notice. NMFS will independently evaluate the Foundation's draft EA and
determine whether or not to adopt it or prepare a separate NEPA
analysis and incorporate relevant portions of the Foundation's draft EA
by reference. NMFS will review all comments submitted in response to
this notice to complete the NEPA process prior to making a final
decision on the Authorization request.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes
issuing an Authorization to the Observatory for conducting a seismic
survey in the northwest Atlantic Ocean off the New Jersey coast May 29,
2014 through August 17, 2014, provided they incorporate the previously
mentioned mitigation, monitoring, and reporting requirements.
Draft Proposed Authorization
This section contains the draft text for the proposed
Authorization. NMFS proposes to include this language in the
Authorization if issued.
Incidental Harassment Authorization
We hereby authorize the Lamont-Doherty Earth Observatory
(Observatory), Columbia University, P.O. Box 1000, 61 Route 9W,
Palisades, New York 10964-8000, under section 101(a)(5)(D) of the
Marine Mammal Protection Act (MMPA) (16 U.S.C. 1371(a)(5)(D)) and 50
CFR 216.107, to incidentally harass small numbers of marine mammals
incidental to a marine geophysical survey conducted by the R/V Marcus
G. Langseth (Langseth) marine geophysical survey in the northwest
Atlantic Ocean off the New Jersey coast May 29, 2014 through August 17,
2014.
1. Effective Dates
This Authorization is valid from May 29, 2014 through August 17,
2014.
2. Specified Geographic Region
This Authorization is valid only for specified activities
associated with the R/V Marcus G. Langseth's (Langseth) seismic
operations as specified in the Observatory's Incidental Harassment
Authorization (IHA) application and environmental analysis in the
following specified geographic area:
a. In the Atlantic Ocean bounded by the following coordinates:
Approximately 25 to 85 km (15.5 to 52.8 mi) off the coast of New Jersey
between approximately 39.3-39.7[deg] N and approximately 73.2-73.8[deg]
W as specified in the Observatory's application and the National
Science Foundation's environmental analysis.
3. Species Authorized and Level of Takes
a. This authorization limits the incidental taking of marine
mammals, by Level B harassment only, to the following species in the
area described in Condition 2(a):
i. Mysticetes--3 north Atlantic right whales; 2 humpback whales; 2
common minke whales; 2 sei whales; 2 fin whales; and 17 blue whales.
ii. Odontocetes--18 sperm whales; 2 dwarf sperm whales; 2 pygmy
sperm whales; 3 Cuvier's beaked whales; 3 Gervais beaked whales; 3
Sowerby's beaked whales; 3 unidentified Mesoplodon species (includes
True's and Blainville beaked and northern bottlenose whales); 279
bottlenose dolphins (coastal or pelagic); 90 Atlantic spotted dolphins;
47 striped dolphins; 18 short-beaked common dolphins; 15 Atlantic
white-sided dolphins; 35 Risso's dolphins; 9 long-finned pilot whales;
9 short-finned pilot whales; and 2 harbor porpoises.
iii. Pinnipeds--8 gray seals; 112 harbor seals; and 4 harp seals.
iv. During the seismic activities, if the Holder of this
Authorization encounters any marine mammal species that are not listed
in Condition 3 for authorized taking and are likely to be exposed to
sound pressure levels greater than or equal to 160 decibels (dB) re: 1
[mu]Pa, then the Holder must alter speed or course or shut-down the
airguns to avoid take.
b. This Authorization prohibits the taking by injury (Level A
harassment), serious injury, or death of any of the species listed in
Condition 3 or the taking of any kind of any other species of marine
mammal. Thus, it may result in the modification, suspension or
revocation of this Authorization.
c. This Authorization limits the methods authorized for taking by
Level B harassment to the following acoustic sources without an
amendment to this Authorization:
i. A sub-airgun array with a total capacity of 1,700 in\3\ (or
smaller);
ii. an acoustic Doppler current profiler;
iii. a multi-beam echosounder; and
iv. a sub-bottom profiler.
4. Reporting Prohibited Take
The Holder of this Authorization must report the taking of any
marine mammal in a manner prohibited under this Authorization
immediately to the Office of Protected Resources, National Marine
Fisheries Service, at 301-427-8401 and/or by email to
[email protected] and [email protected].
5. Cooperation
We require the Holder of this Authorization to cooperate with the
Office of Protected Resources, National Marine Fisheries Service, and
any other Federal, state or local agency monitoring the impacts of the
activity on marine mammals.
6. Mitigation and Monitoring Requirements
We require the Holder of this Authorization to implement the
following mitigation and monitoring requirements when conducting the
specified activities to achieve the least practicable adverse impact on
affected marine mammal species or stocks:
Visual Observers
a. Utilize two, National Marine Fisheries Service-qualified,
vessel-based Protected Species Visual Observers (visual observers) to
watch for and monitor marine mammals near the seismic source vessel
during daytime airgun operations (from civil twilight-dawn to civil
twilight-dusk) and before and during start-ups of airguns day or night.
i. At least one visual observer will be on watch during meal times
and restroom breaks.
ii. Observer shifts will last no longer than four hours at a time.
iii. Visual observers will also conduct monitoring while the
Langseth crew deploy and recover the airgun array and streamers from
the water.
iv. When feasible, visual observers will conduct observations
during daytime periods when the seismic system is not operating for
comparison of sighting rates and behavioral reactions during, between,
and after airgun operations.
v. The Langseth's vessel crew will also assist in detecting marine
mammals, when practicable. Visual observers will have access to reticle
binoculars (7x50 Fujinon), and big-eye binoculars (25x150).
Exclusion Zones
b. Establish a 180-decibel (dB) or 190-dB exclusion zone (zone) for
cetaceans and pinnipeds, respectively before starting the airgun
subarray (1,700 in\3\); and a 180-dB or 190-dB exclusion zone
[[Page 14805]]
for cetaceans and pinnipeds, respectively for the single airgun (40
in\3\). Observers will use the predicted radius distance for the 180-dB
or 190-dB exclusion zone for cetaceans and pinnipeds.
Visual Monitoring at the Start of Airgun Operations
c. Monitor the entire extent of the zones for at least 30 minutes
(day or night) prior to the ramp-up of airgun operations after a
shutdown.
d. Delay airgun operations if the visual observer sees a cetacean
within the 180-dB zone for cetaceans or 190-dB zone for pinnipeds until
the marine mammal(s) has left the area.
i. If the visual observer sees a marine mammal that surfaces, then
dives below the surface, the observer shall wait 30 minutes. If the
observer sees no marine mammals during that time, he/she should assume
that the animal has moved beyond the 180-dB zone for cetaceans or 190-
dB zone for pinnipeds.
ii. If for any reason the visual observer cannot see the full 180-
dB zone for cetaceans or the 190-dB zone for pinnipeds for the entire
30 minutes (i.e., rough seas, fog, darkness), or if marine mammals are
near, approaching, or within zone, the Langseth may not resume airgun
operations.
iii. If one airgun is already running at a source level of at least
180 dB re: 1 [mu]Pa or 190 dB re: 1 [mu]Pa, the Langseth may start the
second gun--and subsequent airguns--without observing relevant
exclusion zones for 30 minutes, provided that the observers have not
seen any marine mammals near the relevant exclusion zones (in
accordance with Condition 6(b)).
Passive Acoustic Monitoring
e. Utilize the passive acoustic monitoring (PAM) system, to the
maximum extent practicable, to detect and allow some localization of
marine mammals around the Langseth during all airgun operations and
during most periods when airguns are not operating. One visual observer
and/or bioacoustician will monitor the PAM at all times in shifts no
longer than 6 hours. A bioacoustician shall design and set up the PAM
system and be present to operate or oversee PAM, and available when
technical issues occur during the survey.
f. Do and record the following when an observer detects an animal
by the PAM:
i. Notify the visual observer immediately of a vocalizing marine
mammal so a power-down or shut-down can be initiated, if required;
ii. Enter the information regarding the vocalization into a
database. The data to be entered include an acoustic encounter
identification number, whether it was linked with a visual sighting,
date, time when first and last heard and whenever any additional
information was recorded, position, and water depth when first
detected, bearing if determinable, species or species group (e.g.,
unidentified dolphin, sperm whale), types and nature of sounds heard
(e.g., clicks, continuous, sporadic, whistles, creaks, burst pulses,
strength of signal, etc.), and any other notable information.
Ramp-Up Procedures
g. Implement a ``ramp-up'' procedure when starting the airguns at
the beginning of seismic operations or anytime after the entire array
has been shutdown, which means start the smallest gun first and add
airguns in a sequence such that the source level of the array will
increase in steps not exceeding approximately 6 dB per 5-minute period.
During ramp-up, the observers will monitor the exclusion zone, and if
marine mammals are sighted, a course/speed alteration, power-down, or
shutdown will be implemented as though the full array were operational.
Recording Visual Detections
h. Visual observers must record the following information when they
have sighted a marine mammal:
i. Species, group size, age/size/sex categories (if determinable),
behavior when first sighted and after initial sighting, heading (if
consistent), bearing and distance from seismic vessel, sighting cue,
apparent reaction to the airguns or vessel (e.g., none, avoidance,
approach, paralleling, etc., and including responses to ramp-up), and
behavioral pace; and
ii. Time, location, heading, speed, activity of the vessel
(including number of airguns operating and whether in state of ramp-up
or shut-down), Beaufort sea state and wind force, visibility, and sun
glare; and
iii. The data listed under 6(f)(ii) at the start and end of each
observation watch and during a watch whenever there is a change in one
or more of the variables.
Speed or Course Alteration
i. Alter speed or course during seismic operations if a marine
mammal, based on its position and relative motion, appears likely to
enter the relevant exclusion zone. If speed or course alteration is not
safe or practicable, or if after alteration the marine mammal still
appears likely to enter the exclusion zone, the Holder of this
Authorization will implement further mitigation measures, such as a
shutdown.
Power-Down Procedures
j. Power down the airguns if a visual observer detects a marine
mammal within, approaching, or entering the relevant exclusion zones. A
power-down means reducing the number of operating airguns to a single
operating 40 in\3\ airgun. This would reduce the exclusion zone to the
degree that the animal(s) is outside of it.
Resuming Airgun Operations After a Power-Down
k. Following a power-down, if the marine mammal approaches the
smaller designated exclusion zone, the airguns must then be completely
shut-down. Airgun activity will not resume until the observer has
visually observed the marine mammal(s) exiting the exclusion zone and
is not likely to return, or has not been seen within the exclusion zone
for 15 minutes for species with shorter dive durations (small
odontocetes) or 30 minutes for species with longer dive durations
(mysticetes and large odontocetes, including sperm, pygmy sperm, dwarf
sperm, killer, and beaked whales).
l. Following a power-down and subsequent animal departure, the
Langseth may resume airgun operations at full power. Initiation
requires that the observers can effectively monitor the full exclusion
zones described in Condition 6(b). If the observer sees a marine mammal
within or about to enter the relevant zones then the Langseth will
implement a course/speed alteration, power-down, or shutdown.
Shutdown Procedures
m. Shutdown the airgun(s) if a visual observer detects a marine
mammal within, approaching, or entering the relevant exclusion zone. A
shutdown means that the Langseth turns off all operating airguns.
n. If a North Atlantic right whale (Eubalaena glacialis) is
visually sighted, the airgun array will be shut-down regardless of the
distance of the animal(s) to the sound source. The array will not
resume firing until 30 minutes after the last documented whale visual
sighting.
Resuming Airgun Operations After a Shutdown
o. Following a shutdown, if the observer has visually confirmed
that the animal has departed the 180-dB zone for cetaceans or the 190-
dB zone for pinnipeds within a period of less than
[[Page 14806]]
or equal to 8 minutes after the shutdown, then the Langseth may resume
airgun operations at full power.
p. Else, if the observer has not seen the animal depart the 180-dB
zone for cetaceans or the 190-dB zone for pinnipeds, the Langseth shall
not resume airgun activity until 15 minutes has passed for species with
shorter dive times (i.e., small odontocetes and pinnipeds) or 30
minutes has passed for species with longer dive durations (i.e.,
mysticetes and large odontocetes, including sperm, pygmy sperm, dwarf
sperm, killer, and beaked whales). The Langseth will follow the ramp-up
procedures described in Conditions 6(g).
Survey Operations at Night
q. The Langseth may continue marine geophysical surveys into night
and low-light hours if the Holder of the Authorization initiates these
segment(s) of the survey when the observers can view and effectively
monitor the full relevant exclusion zones.
r. This Authorization does not permit the Holder of this
Authorization to initiate airgun array operations from a shut-down
position at night or during low-light hours (such as in dense fog or
heavy rain) when the visual observers cannot view and effectively
monitor the full relevant exclusion zones.
s. To the maximum extent practicable, the Holder of this
Authorization should schedule seismic operations (i.e., shooting the
airguns) during daylight hours.
Mitigation Airgun
t. The Langseth may operate a small-volume airgun (i.e., mitigation
airgun) during turns and maintenance at approximately one shot per
minute. The Langseth would not operate the small-volume airgun for
longer than three hours in duration during turns. During turns or brief
transits between seismic tracklines, one airgun would continue to
operate.
7. Reporting Requirements
This Authorization requires the Holder of this Authorization to:
a. Submit a draft report on all activities and monitoring results
to the Office of Protected Resources, National Marine Fisheries
Service, within 90 days of the completion of the Langseth's cruise.
This report must contain and summarize the following information:
i. Dates, times, locations, heading, speed, weather, sea conditions
(including Beaufort sea state and wind force), and associated
activities during all seismic operations and marine mammal sightings;
ii. Species, number, location, distance from the vessel, and
behavior of any marine mammals, as well as associated seismic activity
(number of shutdowns), observed throughout all monitoring activities.
iii. An estimate of the number (by species) of marine mammals with
known exposures to the seismic activity (based on visual observation)
at received levels greater than or equal to 160 dB re: 1 [mu]Pa and/or
180 dB re 1 [mu]Pa for cetaceans and 190-dB re 1 [mu]Pa for pinnipeds
and a discussion of any specific behaviors those individuals exhibited.
iv. An estimate of the number (by species) of marine mammals with
estimated exposures (based on modeling results) to the seismic activity
at received levels greater than or equal to 160 dB re: 1 [mu]Pa and/or
180 dB re 1 [mu]Pa for cetaceans and 190-dB re 1 [mu]Pa for pinnipeds
with a discussion of the nature of the probable consequences of that
exposure on the individuals.
v. A description of the implementation and effectiveness of the:
(A) terms and conditions of the Biological Opinion's Incidental Take
Statement (attached); and (B) mitigation measures of the Incidental
Harassment Authorization. For the Biological Opinion, the report will
confirm the implementation of each Term and Condition, as well as any
conservation recommendations, and describe their effectiveness, for
minimizing the adverse effects of the action on Endangered Species Act
listed marine mammals.
b. Submit a final report to the Chief, Permits and Conservation
Division, Office of Protected Resources, National Marine Fisheries
Service, within 30 days after receiving comments from us on the draft
report. If we decide that the draft report needs no comments, we will
consider the draft report to be the final report.
8. Reporting Prohibited Take
In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner not permitted by the
authorization (if issued), such as an injury, serious injury, or
mortality (e.g., ship-strike, gear interaction, and/or entanglement),
the Observatory shall immediately cease the specified activities and
immediately report the take to the Incidental Take Program Supervisor,
Permits and Conservation Division, Office of Protected Resources, NMFS,
at 301-427-8401 and/or by email to [email protected] and
[email protected] and the Northeast Regional Stranding Coordinator at
(978) 281-9300. 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).
The Observatory shall not resume its activities until we are able
to review the circumstances of the prohibited take. We shall work with
the Observatory to determine what is necessary to minimize the
likelihood of further prohibited take and ensure MMPA compliance. The
Observatory may not resume their activities until notified by us via
letter, email, or telephone.
9. Reporting an Injured or Dead Marine Mammal With an Unknown Cause of
Death
In the event that the Observatory discovers an injured or dead
marine mammal, and the lead visual observer 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 we describe in
the next paragraph), the Observatory will immediately report the
incident to the Incidental Take Program Supervisor, Permits and
Conservation Division, Office of Protected Resources, NMFS, at 301-427-
8401 and/or by email to [email protected] and [email protected]
and the Northeast Regional Stranding Coordinator at (978) 281-9300. The
report must include the same information identified in the paragraph
above this section. Activities may continue while NMFS reviews the
circumstances of the incident. NMFS would work with the Observatory to
determine whether modifications in the activities are appropriate.
10. Reporting an Injured or Dead Marine Mammal Unrelated to the
Activities
In the event that the Observatory discovers an injured or dead
marine mammal, and the lead visual observer determines that the injury
or death is not associated with or related to the authorized activities
(e.g., previously
[[Page 14807]]
wounded animal, carcass with moderate to advanced decomposition, or
scavenger damage), the Observatory would report the incident to the
Incidental Take Program Supervisor, Permits and Conservation Division,
Office of Protected Resources, NMFS, at 301-427-8401 and/or by email to
[email protected] and [email protected] and the Northeast
Regional Stranding Coordinator at (978) 281-9300, within 24 hours of
the discovery. The Observatory would provide photographs or video
footage (if available) or other documentation of the stranded animal
sighting to NMFS.
11. Endangered Species Act Biological Opinion and Incidental Take
Statement
The Observatory is required to comply with the Terms and Conditions
of the Incidental Take Statement corresponding to the Endangered
Species Act Biological Opinion issued to the National Science
Foundation and NMFS' Office of Protected Resources, Permits and
Conservation Division (attached). A copy of this Authorization and the
Incidental Take Statement must be in the possession of all contractors
and protected species observers operating under the authority of this
Incidental Harassment Authorization.
Request for Public Comments
NMFS requests comments on our analysis, the draft authorization,
and any other aspect of the Notice of proposed Authorization for the
Observatory's activities. Please include any supporting data or
literature citations with your comments to help inform our final
decision on the Observatory's request for an application.
Dated: March 10, 2014.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2014-05553 Filed 3-14-14; 8:45 am]
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