[Federal Register Volume 79, Number 147 (Thursday, July 31, 2014)]
[Notices]
[Pages 44550-44578]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-17998]
[[Page 44549]]
Vol. 79
Thursday,
No. 147
July 31, 2014
Part IV
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 North
Carolina, September to October 2014; Notice
Federal Register / Vol. 79 , No. 147 / Thursday, July 31, 2014 /
Notices
[[Page 44550]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XD394
Takes of Marine Mammals Incidental to Specified Activities;
Marine Geophysical Survey in the Northwest Atlantic Ocean Offshore
North Carolina, September to October 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 (Lamont-Doherty) 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 North Carolina coast from September through
October, 2014. The proposed dates for this action would be September
15, 2014 through October 31, 2014, to account for minor deviations due
to logistics and weather. In accordance with the Marine Mammal
Protection Act, we are requesting comments on our proposal to issue an
Authorization to Lamont-Doherty to incidentally take, by Level B
harassment only, 24 species of marine mammals during the specified
activity.
DATES: NMFS must receive comments and information on or before
September 2, 2014.
ADDRESSES: Address comments on the application to Jolie Harrison,
Chief, 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-XD394 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, 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 Cape Hatteras,
September-October 2014,'' prepared by LGL, Ltd. environmental research
associates, on behalf of the Foundation and Lamont-Doherty is available
at the same internet address. Information in the Lamont-Doherty'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.
Through the authority delegated by the Secretary, NMFS
(hereinafter, we) shall grant an Authorization for the incidental
taking of small numbers of marine mammals if we find 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 prescribe, where applicable, the
permissible methods of taking by harassment pursuant to the activity;
other means of effecting the least practicable adverse impact on the
species or stock and its habitat, and on the availability of such
species or stock for taking for subsistence uses (where applicable);
the measures that we determine are necessary to ensure no unmitigable
adverse impact on the availability for the species or stock for taking
for subsistence purposes (where applicable); and requirements
pertaining to the mitigation, monitoring and reporting of such taking.
We have 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 February 26, 2014, we received an application from Lamont-
Doherty requesting that we issue an Authorization for the take of
marine mammals, incidental to conducting a seismic survey offshore Cape
Hatteras, NC September through October, 2014. NMFS determined the
application complete and adequate on July 15, 2014.
Lamont-Doherty proposes to conduct a high-energy, 2-dimensional (2-
D) seismic survey on the R/V Langseth in the Atlantic Ocean
approximately 17 to 422 kilometers (km) (10 to 262 miles (mi)) off the
coast of Cape Hatteras, NC for approximately 38 days from September 15
to October 22, 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 24
species of marine mammals could result from the specified activity.
[[Page 44551]]
Description of the Specified Activity
Overview
Lamont-Doherty plans to use one source vessel, the R/V Marcus G.
Langseth (Langseth), seismic airgun arrays configured with 18 or 36
airguns as the energy source, one hydrophone streamer, and 90 ocean
bottom seismometers (seismometers) to conduct the conventional seismic
survey. In addition to the operations of the airguns, Lamont-Doherty
proposes to 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
mid-Atlantic coast of the East North America Margin (ENAM). The study
would cover a portion of the rifted margin of the eastern U.S. and the
results would allow scientists to investigate how the continental crust
stretched and separated during the opening of the Atlantic Ocean and
magnetism's role during the continental breakup. The proposed seismic
survey is purely scientific in nature and not related to oil and
natural gas exploration on the outer continental shelf of the Atlantic
Ocean.
Dates and Duration
Lamont-Doherty proposes to conduct the seismic survey from the
period of September 15 through October 22, 2014. The proposed study
(e.g., equipment testing, startup, line changes, repeat coverage of any
areas, and equipment recovery) would include approximately 792 hours of
airgun operations (i.e., a 24-hour operation over 33 days). Some minor
deviation from Lamont-Doherty's requested dates of September 15 through
October 22, 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 September 15, 2014 through October 31, 2014. Lamont-
Doherty will not conduct the survey after October 31, 2014 to avoid
exposing North Atlantic right whales (Eubalaena glacialis) to sound at
the beginning of their migration season.
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
Lamont-Doherty proposes to conduct the seismic survey in the
Atlantic Ocean, approximately 17 to 422 kilometers (km) (10 to 262
miles (mi)) off the coast of Cape Hatteras, NC between approximately
32--37[deg] N and approximately 71.5--77[deg] W (see Figure 1 in this
notice). Water depths in the survey area are approximately 20 to 5,300
m (66 feet (ft) to 3.3 mi). They would conduct the proposed survey
outside of North Carolina state waters, within the U.S. Exclusive
Economic Zone, and partly in international waters.
Principal Investigators
The proposed study's principal investigators are: Drs. H. Van
Avendonk and G. Christeson (University of Texas at Austin). B. Magnani
(University of Memphis), D. Shillington, A. B[eacute]cel, and J.
Gaherty (Lamont-Doherty), M. Hornbach (Southern Methodist University),
B. Dugan (Rice University), M. Long (Yale University), M. Benoit (The
College of New Jersey), and S. Harder (University of Texas at El Paso).
[[Page 44552]]
[GRAPHIC] [TIFF OMITTED] TN31JY14.004
Detailed Description of Activities
Transit Activities
The Langseth would depart from Norfolk, VA on September 15, 2014,
and transit for approximately one day to the proposed survey area.
Setup, deployment, and streamer ballasting would occur over
approximately three days and seismic acquisition would take
approximately 33 days. At the conclusion of the proposed survey, the
Langseth would take approximately one day to retrieve gear. At the
conclusion of the proposed survey activities, the Langseth would return
to Norfolk, VA on October 22, 2014.
Vessel Specifications
The survey would involve one source vessel, the R/V Langseth, and
two support vessels. The Langseth, owned by the Foundation and operated
by Lamont-Doherty, 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 (rpm). The
vessel also has an 800-hp bowthruster, which is not active during
seismic acquisition.
The Langseth'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 five degrees per minute, limiting its maneuverability during
operations while it tows the hydrophone streamer.
The Langseth 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 University of Rhode Island's Graduate School of Oceanography
operates the first support vessel, the R/V Endeavor (Endeavor) which
has a length of 56.4 m (184 ft), a beam of 10.1 m (33 ft), and a
maximum draft of 5.6 m (18.3 ft). The Endeavor has one diesel engine
that produces 3050 hp and drives the single propeller directly at a
maximum of 900 rpm. The Endeavor can cruise at approximately 10 kt
(18.5 km/hr; 11.5 mph).
The second support vessel would be a multi-purpose offshore utility
vessel similar to the Northstar Commander,
[[Page 44553]]
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 5,185 km (3,221 mi)
of transect lines (approximately 3,425 km for the multi-channel seismic
and approximately 1,760 km for the seismometer acquisition operations)
within the survey area. This represents a 1,165 km reduction in
transect lines from Lamont-Doherty's original proposal that totaled
6,350 km (3,946 mi) of transect lines within the survey area.
During the survey, the Langseth crew would deploy a four-string
array consisting of 36 airguns with a total discharge volume of
approximately 6,600 cubic inches (in\3\), or a two-string array
consisting of 18 airguns with a total discharge volume of 3,300 in\3\
as an energy source. The Langseth would tow the four-string array at a
depth of approximately 9 m (30 ft) and would tow the two-string array
at a depth of 6 m (20 ft). The shot interval during seismometer
acquisition would be approximately 65 seconds every 150 m (492 ft) and
22 seconds every 50 m (164 ft) during multi-channel acquisition
operations. During acquisition, the airguns will emit a brief
(approximately 0.1 second) pulse of sound and during the intervening
periods of operations, the airguns are silent. The receiving system
would consist of one 8-km (5-mi) hydrophone streamer which would
receive the returning acoustic signals and transfer the data to the on-
board processing system. In addition to the hydrophone, the study would
also use approximately 90 seismometers placed on the seafloor to record
the returning acoustic signals from the airgun array internally for
later analysis.
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).
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 array on the Langseth range
from 246 to 253 decibels (dB) re: 1 [micro]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
([micro]Pa)). The effective source levels for horizontal propagation
are lower than source levels for downward propagation and the relative
sound intensities given in dB in water are not the same as relative
sound intensities given in dB in air. We refer the reader to the
Foundation's 2014 EA for this project and their 2011 Programmatic
Environmental Impact Statement (PEIS) for a detailed description of the
airguns and airgun configurations proposed for use in this study.
Ocean Bottom Seismometers
Lamont-Doherty proposes to place 90 seismometers on the sea floor
prior to the initiation of the seismic survey. Each seismometer is
approximately 0.9 m (2.9 ft) high with a maximum diameter of 97
centimeters (cm) (3.1 ft). An anchor, made of a rolled steel bar grate
which measures approximately 7 by 91 by 91.5 cm (3 by 36 by 36 inches)
and weighs 45 kilograms (99 pounds) would anchor the seismometer to the
seafloor. We refer the reader to section 2.1.3.2 in the Foundation's
2011 PEIS for a detailed description of this passive acoustic recording
system.
The Endeavor crew would deploy and retrieve the seismometers one-
by-one from the stern of the vessel while onboard protected species
observers will alert them to the presence of marine mammals and
recommend ceasing deploying or recovering the seismometers to avoid
potential entanglement with marine mammals.
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 [micro]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: Lamont-Doherty 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' 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.
Lamont-Doherty presented species information in Table 2 of their
application but excluded information on harbor seals and four other
cetacean species because they anticipated that these species would have
a more northerly distribution during the summer and thus would have a
low
[[Page 44554]]
likelihood of occurring in the survey area. The excluded cetacean
species include: Bryde's whale (Balaenoptera edeni), northern
bottlenose whale (Hyperoodon ampullatus), Sowerby's beaked whale
(Mesoplodon bidens), and the white-beaked dolphin (Lagenorhynchus
albirostris).
Based on the best available information (DoN, 2012), we expect that
Bryde's whale may have the potential to occur within the survey area
and have included additional information for this species in Table 1 of
this notice. However, we agree with Lamont-Doherty that the other
species identified earlier have a low likelihood of occurrence in the
action area during September and October.
Table 1--General Information on Marine Mammals That Could Potentially Occur in the Proposed Activity Area in September Through October, 2014
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Regulatory status \1\ Stock/Species Occurrence in summer/
Species Stock name \2\ Abundance \3\ Range fall
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North Atlantic right whale Western Atlantic..... MMPA-D, ESA-EN....... 455 Coastal/shelf.................. Uncommon.
(Eubalaena glacialis).
Humpback whale (Megaptera Gulf of Maine........ MMPA-D, ESA-EN....... 823 Pelagic........................ Uncommon.
novaeangliae).
Minke whale (Balaenoptera Canadian East Coast.. MMPA-D, ESA-NL....... 20,741 Coastal/shelf.................. Uncommon.
acutorostrata).
Sei whale (Balaenoptera borealis). Nova Scotia.......... MMPA-D, ESA-EN....... 357 Offshore....................... Rare.
Fin whale (Balaenoptera physalus). Western North MMPA-D, ESA-EN....... 3,522 Pelagic........................ Rare.
Atlantic.
Blue whale (Balaenoptera musculus) Western North MMPA-D, ESA-EN....... \4\ 440 Coastal/pelagic................ Rare.
Atlantic.
Bryde's whale (Balaenoptera edeni) NA................... MMPA-D, ESA-NL....... \5\ 11,523 Shelf/pelagic.................. Uncommon.
Sperm whale (Physeter Nova Scotia.......... MMPA-D, ESA-EN....... 2,288 Pelagic........................ Common.
macrocephalus).
Dwarf sperm whale (Kogia sima).... Western North MMPA-NC, ESA-NL...... 3,785 Off Shelf...................... Uncommon.
Atlantic.
Pygmy sperm whale (K. breviceps).. Western North MMPA-NC, ESA-NL...... 3,785 Off Shelf...................... Uncommon.
Atlantic.
Blainville's beaked whale Western North MMPA-NC, ESA-NL...... 7,092 Pelagic........................ Rare.
(Mesoplodon densirostris). Atlantic.
Cuvier's beaked whale (Ziphius Western North MMPA-NC, ESA-NL...... 7,092 Pelagic........................ Uncommon.
cavirostris). Atlantic.
Gervais' beaked whale (M. Western North MMPA-NC, ESA-NL...... 7,092 Pelagic........................ Rare.
europaeus). Atlantic.
True's beaked whale (M. mirus).... Western North MMPA-NC, ESA-NL...... 7,092 Pelagic........................ Rare.
Atlantic.
Rough-toothed dolphin (Steno Western North MMPA-NC, ESA-NL...... 271 Pelagic........................ Uncommon.
bredanensis). Atlantic.
Bottlenose dolphin (Tursiops Western North MMPA-NC, ESA-NL...... 77,532 Pelagic........................ Common.
truncatus). Atlantic Offshore.
Western North MMPA-D, S, ESA-NL.... 9,173 Coastal........................ Common.
Atlantic Southern
Migratory Coastal.
WNA Southern NC MMPA-D, S, ESA-NL.... 188 Coastal........................ Common.
Estuarine System.
WNA Northern NC MMPA-D, S, ESA-NL.... 950 Coastal........................ Common.
Estuarine System.
Pantropical spotted dolphin Western North MMPA-NC, ESA-NL...... 3,333 Pelagic........................ Common.
(Stenella attenuata). Atlantic.
Atlantic spotted dolphin (S. Western North MMPA-NC, ESA-NL...... 44,715 Shelf/slope pelagic............ Common.
frontalis). Atlantic.
Spinner dolphin (S. longirostris). Western North MMPA-NC, ESA-NL...... \6\ 11,441 Coastal/pelagic................ Rare.
Atlantic.
Striped dolphin (S. coeruleoalba). Western North MMPA-NC, ESA-NL...... 54,807 Off shelf...................... Common.
Atlantic.
Clymene dolphin (S. clymene)...... Western North MMPA-NC, ESA-NL...... \7\ 6,086 Slope.......................... Uncommon.
Atlantic.
Short-beaked common dolphin Western North MMPA-NC, ESA-NL...... 173,486 Shelf/pelagic.................. Common.
(Delphinus delphis). Atlantic.
Atlantic white-sided-dolphin (L. Western North MMPA-NC, ESA-NL...... 48,819 Shelf/slope.................... Rare.
acutus). Atlantic.
Fraser's dolphin (Lagenodelphis Western North MMPA-NC, ESA-NL...... \8\ 726 Pelagic........................ Rare.
hosei). Atlantic.
Risso's dolphin (Grampus griseus). Western North MMPA-NC, ESA-NL...... 18,250 Shelf/slope.................... Common.
Atlantic.
[[Page 44555]]
Melon-headed whale (Peponocephala Western North MMPA-NC, ESA-NL...... \9\ 2,283 Pelagic........................ Rare.
electra). Atlantic.
False killer whale (Pseudorca Northern Gulf of MMPA-NC, ESA-NL...... \10\ 177 Pelagic........................ Rare.
crassidens). Mexico.
Pygmy killer whale (Feresa Western North MMPA-NC, ESA-NL...... \11\ 1,108 Pelagic........................ Rare.
attenuate). Atlantic.
Killer whale (Orcinus orca)....... Western North MMPA-NC, ESA-NL...... \12\ 28 Coastal........................ Rare.
Atlantic.
Long-finned pilot whale Western North MMPA-NC, ESA-NL...... 26,535 Pelagic........................ Common.
(Globicephala melas). Atlantic.
Short-finned pilot whale (G. Western North MMPA-NC, ESA-NL...... 21,515 Pelagic........................ Common.
macrorhynchus). Atlantic.
Harbor porpoise (Phocoena Gulf of Maine/Bay of MMPA-NC, ESA-NL...... 79,883 Coastal........................ Rare.
phocoena). Fundy.
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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\ 2013 NMFS Stock Assessment Report (Waring et al., 2014) unless otherwise noted. NA = Not Available.
\4\ Minimum population estimate based on photo identification studies in the Gulf of St. Lawrence (Waring et al., 2010).
\5\ There is no stock designation for this species in the Atlantic. Abundance estimate derived from the ETP stock = 11,163 (Wade and Gerodette, 1993);
Hawaii stock = 327 (Barlow, 2006); and Northern Gulf of Mexico stock = 33 (Waring et al., 2012).
\6\ There is no abundance information for this species in the Atlantic. Abundance estimate derived from the Northern Gulf of Mexico Stock = 11,441
(Waring et al., 2012).
\7\ There is no abundance information for this species in the Atlantic. The best available estimate of abundance was 6,086 (CV=0.93) (Mullin and
Fulling, 2003).
\8\ There is no abundance information for this species in the Atlantic. The best available estimate of abundance was 726 (CV=0.70) for the Gulf of
Mexico stock (Mullin and Fulling, 2004).
\9\ There is no abundance information for this species in the Atlantic. The best available estimate of abundance was 2,283 (CV=0.76) for the Gulf of
Mexico stock (Mullin, 2007).
\10\ There is no abundance information for this species in the Atlantic. The best available estimate of abundance was 177 (CV=0.56) for the Gulf of
Mexico stock (Mullin, 2007).
\11\ There is no abundance information for this species in the Atlantic. Abundance estimate derived from the Northern Gulf of Mexico stock = 152
(Mullin, 2007) and the Hawaii stock = 956 (Barlow, 2006).
\12\ There is no abundance information for this species in the Atlantic. Abundance estimate derived from the Northern Gulf of Mexico stock = 28 (Waring
et al., 2012).
NMFS refers the public to Lamont-Doherty's application, the
Foundation's EA (see ADDRESSES), and the 2013 NMFS Marine Mammal Stock
Assessment Report available online at: http://www.nmfs.noaa.gov/pr/sars/pdf/ao2013_draft.pdf 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 we consider to rise to the level of a take.
We intend to provide a background of potential effects of Lamont-
Doherty's activities in this section. This section does not consider
the specific manner in which Lamont-Doherty would carry out the
proposed activity, what mitigation measures Lamont-Doherty 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 Lamont-Doherty to
take during this activity. The ``Negligible Impact Analysis'' section
will include the analysis of how this specific activity would impact
marine mammals. We 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
[[Page 44556]]
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, 24 marine mammal species
(7 mysticetes and 17 odontocetes) would likely occur in the proposed
action area. Table 2 presents the classification of these 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.
Table 2--Classification of Marine Mammals That Could Potentially Occur in the Proposed Activity Area in
September Through October, 2014 by Functional Hearing Group (Southall et. al., 2007)
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Low frequency hearing range...................................... North Atlantic right, humpback, Bryde's,
minke, sei, fin, and blue whale.
Mid-frequency hearing range...................................... Sperm whale, Blainville's beaked whale,
Cuvier's beaked whale, Gervais' beaked
whale, True's beaked whale, false killer
whale, pygmy killer whale, killer whale,
rough-toothed dolphin, bottlenose dolphin,
pantropical spotted dolphin, Atlantic
spotted dolphin, striped dolphin, Clymene
dolphin, short-beaked common dolphin,
Risso's dolphin, long-finned pilot whale,
short-finned pilot whale.
High frequency hearing range..................................... Harbor porpoise
----------------------------------------------------------------------------------------------------------------
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). 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).
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. 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.,
[[Page 44557]]
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. 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:
[[Page 44558]]
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.
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 [micro]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
[micro]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 [micro]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
[micro]Pa for humpback pods containing females, and at the mean closest
point of approach distance, the received level was 143 dB re: 1
[micro]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
[micro]Pa.
Data collected by observers during several of Lamont-Doherty's
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
[[Page 44559]]
(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 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, 2013). 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, 2013). 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 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 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,
[[Page 44560]]
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 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
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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 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. Marine mammals generally avoid the
immediate area around operating seismic vessels.
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
[[Page 44562]]
Welch (1970) reported physiological 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), we also assume 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.
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.
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 are especially unlikely to incur non-
auditory impairment or other physical effects.
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
Lamont-Doherty 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.
We have considered the potential for behavioral responses such as
stranding and indirect injury or mortality from Lamont-Doherty's use of
the multibeam echosounder. In 2013, an International Scientific Review
Panel (ISRP) investigated a 2008 mass stranding of approximately 100
melon-headed whales in a Madagascar lagoon system (Southall et al.,
2013) associated with the use of a high-frequency mapping system. The
report indicated that the use of a 12-kHz multibeam echosounder was the
most plausible and likely initial behavioral trigger of the mass
stranding event. This was the first time that a relatively high-
frequency mapping sonar system had been associated with a stranding
event. However, the report also notes that there were several site- and
situation-specific secondary factors that may have contributed to the
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avoidance responses that lead to the eventual entrapment and mortality
of the whales within the Loza Lagoon system (e.g., the survey vessel
transiting in a north-south direction on the shelf break parallel to
the shore may have trapped the animals between the sound source and the
shore driving them towards the Loza Lagoon). They concluded that for
odontocete cetaceans that hear well in the 10-50 kHz range, where
ambient noise is typically quite low, high-power active sonars
operating in this range may be more easily audible and have potential
effects over larger areas than low frequency systems that have more
typically been considered in terms of anthropogenic noise impacts
(Southall, et al., 2013). However, the risk may be very low given the
extensive use of these systems worldwide on a daily basis and the lack
of direct evidence of such responses previously reported (Southall, et
al., 2013).
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 Lamont-Doherty'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 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 (Rendell and Gordon,
1999), and strandings 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 Lamont-Doherty'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.
Sub-bottom Profiler
Lamont-Doherty 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--Responses to the profiler are likely to be
similar to the other pulsed sources discussed earlier if received at
the same levels. However, the pulsed signals from the profiler are
considerably weaker than those from the echosounder.
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. We discuss both scenarios here.
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),
[[Page 44564]]
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 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.''
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 size
for the 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. Lamont-Doherty has no recorded
cases of entanglement of marine mammals during their conduct of over 10
years of seismic surveys (NSF, 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. This section describes the potential impacts to marine mammal
habitat from the specified activity.
Anticipated Effects on the Seafloor
The seismometers would occupy approximately 450 square meters
(4,843.7 square miles) of seafloor habitat and may disturb benthic
invertebrates. However, due to the natural sinking of the anchors from
their own weight into the seafloor and natural sedimentation processes,
these impacts would be localized and short-term. We do not expect any
long-term habitat impacts.
[[Page 44565]]
Anticipated Effects on Fish
We consider the effects of the survey on marine mammal prey (i.e.,
fish and invertebrates), as a component of marine mammal habitat in the
following subsections. 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 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 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
(2009) 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.
We are 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
[[Page 44566]]
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., 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
(Lokkeborg et al., 2012; Fewtrell and McCauley, 2012). We would expect
prey species to return to their pre-exposure behavior once seismic
firing ceased (Lokkeborg et al., 2012; Fewtrell and McCauley, 2012).
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.
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 (2011) 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.
Another laboratory study observed abnormalities in larval scallops
after exposure to low frequency noise in tanks (de Soto et al., 2013).
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
[[Page 44567]]
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
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., 2000). 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).
In examining impacts to fish and invertebrates as prey species for
marine mammals, we expect fish to exhibit a range of behaviors
including no reaction or habituation (Pe[ntilde]a et al., 2013) to
startle responses and/or avoidance (Fewtrell & McCauley, 2012). We
expect that the seismic survey would have no more than a temporary and
minimal adverse effect on any fish or invertebrate species. Although
there is a potential for injury to fish or marine life in close
proximity to the vessel, we expect that the impacts of the seismic
survey on fish and other marine life specifically related to acoustic
activities would be temporary in nature, negligible, and would not
result in substantial impact to these species or to their role in the
ecosystem. Based on the preceding discussion, we do 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, we 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).
Lamont-Doherty 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 2014 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, Lamont-Doherty, 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.
We reviewed Lamont-Doherty's proposed mitigation measures and have
proposed additional measures to effect the least practicable adverse
impact on marine mammals. They are:
(1) Expanded shutdown procedures for North Atlantic right whales;
(2) Expanded exclusion zones in shallow water based on lower
thresholds;
(3) Requirements on the directionality of the survey's tracklines.
Vessel-Based Visual Mitigation Monitoring
Lamont-Doherty 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. Protected species
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 exclusion zone (with buffer).
During seismic operations, at least four protected species
observers would be aboard the Langseth. Lamont-Doherty 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, Lamont-Doherty 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
[[Page 44568]]
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: Lamont-Doherty would use safety radii to
designate exclusion zones and to estimate take for marine mammals.
Table 3 shows the distances at which they predicted the received sound
levels (180 dB with buffer, 180 dB, and 160 dB) from the airgun arrays
and a single airgun.
Table 3--Modeled Distances to Which Sound Levels Greater Than or Equal to 160 and 177 dB re: 1 [micro]Pa Could
Be Received During the Proposed Survey in the Atlantic Ocean, September Through October, 2014.
----------------------------------------------------------------------------------------------------------------
Predicted RMS distances \1\ (m)
Water depth -----------------------------------------------
Source and volume (in\3\) Tow depth (m) (m) 180 dB with
buffer 180 dB 160 dB
----------------------------------------------------------------------------------------------------------------
Single bolt airgun (40 in\3\).. 6 or 9 < 100 121 86 938
100-1,000 100 100 582
> 1,000 100 100 388
18-Airgun array (3,300 in\3\).. 6 < 100 1,630 \2\ 1,097 \2\ 15,280 \2\
100-1,000 675 \3\ 675 \3\ 5,640 \3\
> 1,000 450 450 3,760
36-Airgun array (6,600 in\3\).. 9 < 100 2,880 \4\ 2,060 \4\ 22,600 \4\
100-1,000 1,391 1,391 8,670
> 1,000 927 927 5,780
----------------------------------------------------------------------------------------------------------------
\1\ Predicted distances based on Table 1 of the Foundation's application. The Foundation calculated the 180-dB
zone with 3-dB buffer based on our proposed recommendation to expand the 180-dB exclusion zones in shallow
water.
\2\ Predicted distances based on empirically-derived measurements in the Gulf of Mexico for an 18-airgun array.
\3\ Intermediate Depth: Predicted distances based on model results with a correction factor (1.5) between deep
and intermediate water depths.
\4\ Predicted distances based on empirically-derived measurements in the Gulf of Mexico with scaling factor
applied to account for differences in tow depth.
The 180-dB level shutdown criteria are applicable to cetaceans as
specified by NMFS (2000). Lamont-Doherty used these levels to establish
their original exclusion zones. For this survey, we will require
Lamont-Doherty to enlarge the radius of 180-dB exclusion zones for each
airgun array configuration in shallow water by a factor of 3-dB, which
results in an exclusion zone that is 25 percent larger.
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-dB exclusion zone
(with buffer) 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-dB exclusion zone (with
buffer) 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-dB exclusion zone (with buffer) (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-dB exclusion zone after an 8-minute wait period. This period is
based on the 180-dB exclusion zone for the airgun subarray towed at a
depth of 12 m (39.4
[[Page 44569]]
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 shut down 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 shut down 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 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. Lamont-Doherty 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. Lamont-Doherty 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, Lamont-Doherty 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. Lamont-Doherty 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, Lamont-Doherty 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.
Directionality of Survey Tracklines
In order to avoid the potential entrapment of marine mammals within
inshore areas, we proposed to require Lamont-Doherty to plan to conduct
the seismic surveys (especially when near land) from the coast
(inshore) and proceed towards the sea (offshore).
Mitigation Conclusions
We have evaluated Lamont-Doherty'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
[[Page 44570]]
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 us 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 Lamont Doherty's proposed measures, as
well as other measures considered by us, we have 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.
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.
Lamont-Doherty submitted a marine mammal monitoring plan in section
XIII of the Authorization application. We or Lamont-Doherty 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 us 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
Lamont-Doherty 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. Lamont-Doherty understands that we would review the
monitoring plan and may require refinements to the plan.
Lamont-Doherty 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, Lamont-Doherty 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 them.
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
[[Page 44571]]
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 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 Lamont-Doherty 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 Lamont-Doherty 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
Lamont-Doherty 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 Southeast Regional Stranding Coordinator at
(305) 361-4586. 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;
[[Page 44572]]
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).
Lamont-Doherty shall not resume its activities until we are able to
review the circumstances of the prohibited take. We shall work with
Lamont-Doherty to determine what is necessary to minimize the
likelihood of further prohibited take and ensure MMPA compliance.
Lamont-Doherty may not resume their activities until notified by us via
letter, email, or telephone.
In the event that Lamont-Doherty 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), Lamont-Doherty 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 Southeast Regional Stranding Coordinator at (305) 361-4586. The
report must include the same information identified in the paragraph
above this section. Activities may continue while we review the
circumstances of the incident. We would work with Lamont-Doherty to
determine whether modifications in the activities are appropriate.
In the event that Lamont-Doherty 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), Lamont-Doherty 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 Southeast Regional Stranding Coordinator at (305) 361-4586,
within 24 hours of the discovery. Activities may continue while NMFS
reviews the circumstances of the incident. Lamont-Doherty would provide
photographs or video footage (if available) or other documentation of
the stranded animal sighting to us.
Estimated Take by Incidental Harassment
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as: Any act of pursuit, torment, or
annoyance which (i) has the potential to injure a marine mammal or
marine mammal stock in the wild [Level A harassment]; or (ii) has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behavioral patterns, including, but not
limited to, migration, breathing, nursing, breeding, feeding, or
sheltering [Level B harassment].
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, we
propose 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.
Table 2--NMFS' Current Acoustic Exposure Criteria
------------------------------------------------------------------------
Criterion Criterion definition Threshold
------------------------------------------------------------------------
Level A Harassment (Injury). Permanent Threshold 180 dB re 1 microPa-
Shift (PTS) (Any m (cetaceans)/190
level above that dB re 1 microPa-m
which is known to (pinnipeds) root
cause TTS). mean square (rms).
Level B Harassment.......... Behavioral 160 dB re 1 microPa-
Disruption (for m (rms).
impulse noises).
------------------------------------------------------------------------
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]).
The 180-dB level shutdown criteria are applicable to cetaceans as
specified by NMFS (2000). Lamont-Doherty used these levels to establish
their original exclusion zones. For this survey, we will require
Lamont-Doherty to enlarge the radius of 180-dB exclusion zones for each
airgun array configuration in shallow water by a factor of 3-dB, which
results in an exclusion zone that is 25 percent larger.
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, we do not anticipate that take, by vessel strike, would
result from the movement of the vessel.
Lamont-Doherty 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 during concurrent operations of the sound sources.
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
Lamont-Doherty has estimated to result from airgun operations. At this
time, we propose not to authorize additional takes for these sources
for the action. We are 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. We are
working on guidance that would outline a consistent recommended
approach for applicants to address the potential impacts of these types
of sources.
We considered the probability for entanglement of marine mammals to
be low because of the vessel speed and the
[[Page 44573]]
monitoring efforts onboard the survey vessel. Lamont-Doherty has no
recorded cases of entanglement of marine mammals during their conduct
of over 10 years of seismic surveys. Therefore, we do 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 Lamont-Doherty's methods to
estimate take by incidental harassment. Lamont-Doherty based their
estimates on the number of marine mammals that could be harassed by
seismic operations with the airgun array during approximately 6,350 km
(3,946 mi) of transect lines in the Atlantic Ocean.
Ensonified Area Calculations: In order to estimate the potential
number of marine mammals exposed to airgun sounds, Lamont-Doherty
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) around each seismic line, and then calculating the total area
within the buffers.
For this survey, Lamont-Doherty assumes that the Langseth will not
need to repeat some tracklines, accommodate the turning of the vessel,
address equipment malfunctions, or conduct equipment testing to
complete the survey. They propose not to increase the proposed number
of line-kilometers for the seismic operations by 25 percent to account
for these contingency operations. The revised total ensonified area is
approximately 41,170 km\2\ (15,896 mi\2\) a 36.4 percent reduction in
the total ensonified area that Lamont-Doherty proposed in their
application.
Exposure Estimates: Lamont-Doherty calculates the numbers of
different individuals potentially exposed to approximately 160 dB re: 1
[micro]Pa by multiplying the expected species density estimates
(number/km\2\) for that area in the absence of a seismic program times
the estimated area of ensonification (i.e., 41,170 km\2\; 15,896
mi\2\).
Table 3 of their application presents their original 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 during the seismic survey if no animals moved away from the
survey vessel. Lamont-Doherty 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 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.
Lamont-Doherty used the SERDP SDSS tool to obtain mean densities in a
polygon the size of the seismic survey area for the cetacean species
during the fall (September through November).
For the proposed Authorization, we have reviewed Lamont-Doherty's
take estimates presented in Table 3 of their application and have
revised take calculations for some species based upon the best
available density information from SERDP SDSS and other sources noted
in the footnote section for Table 3. These include takes for North
Atlantic right, fin, blue, Bryde's, and sei whales; and the Southern
Migratory Coastal, Southern North Carolina Estuarine System, and
Northern North Carolina Estuarine System stocks of bottlenose dolphins.
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 4--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 Atlantic Ocean, September Through
October 2014
----------------------------------------------------------------------------------------------------------------
Modeled number
Density of individuals Percent of
Species estimate \1\ exposed to Proposed take species or Population trend
(/1000 sound levels authorization stock \3\ \4\
sq km) >=160 dB \2\
----------------------------------------------------------------------------------------------------------------
North Atlantic right whale... Entire area-- 0 \5\ 5 1.10 Increasing.
0.1 \5\.
Humpback whale............... 0.73, 0.56, 38 38 4.62 Increasing.
1.06.
Minke whale.................. 0.03, 0.02, 1 1 0.005 No data.
0.04.
Sei whale.................... Entire area-- 0 \5\ 21 5.88 No data.
0.489 \5\.
Fin whale.................... Entire area-- 1 \5\ 11 0.31 No data.
0.26 \5\.
Blue whale................... Entire area-- 0 \5\ 2 0.45 No data.
0.036 \5\.
Bryde's whale................ Entire area-- 0 \5\ 18 0.16 No data.
0.429 \5\.
Sperm whale.................. 0.03, 0.68, 91 91 5.71 No data.
3.23.
Dwarf sperm whale............ 0.64, 0.49, 33 33 0.87 No data.
0.93.
Pygmy sperm whale............ 0.64, 0.49, 33 33 0.87 No data.
0.93.
Cuvier's beaked whale........ 0.01, 0.14, 17 17 0.24 No data.
0.58.
Blainville's beaked whale.... 0.01, 0.14, 17 17 0.24 No data.
0.58.
Gervais' beaked whale........ 0.01, 0.14, 17 17 0.24 No data.
0.58.
True's beaked whale.......... 0.01, 0.14, 17 17 0.24 No data.
0.58.
Rough-toothed dolphin........ 0.30, 0.23, 16 16 5.90 No data.
0.44.
Bottlenose dolphin (Offshore) 70.4, 331, 49.4 3,383 3,383 4.36 No data.
Bottlenose dolphin (SMC)..... 70.4, 0, 0..... 685 685 7.05 No data.
Bottlenose dolphin (SNCES)... 70.4, 0, 0..... \6\ 1 1 0.53 No data.
Bottlenose dolphin (NNCES)... 70.4, 0, 0..... \6\ 1 1 0.11 No data.
Pantropical spotted dolphin.. 14, 10.7, 20.4. 737 737 22.11 No data.
Atlantic spotted dolphin..... 216.5, 99.7, 4,632 4,632 10.36 No data.
77.4.
[[Page 44574]]
Spinner dolphin.............. 0, 0, 0........ 0 0 0 No data.
Striped dolphin.............. 0, 0.4, 3.53... 98 98 0.18 No data.
Clymene dolphin.............. 6.7, 5.12, 9.73 352 352 5.78 No data.
Short-beaked common dolphin.. 5.8, 138.7, 1,343 1,343 0.77 No data.
26.4.
Atlantic white-sided dolphin. 0, 0, 0........ 0 0 0 No data.
Fraser's dolphin............. 0, 0, 0........ 0 0 0 No data.
Risso's dolphin.............. 1.18, 4.28, 88 88 0.48 No data.
2.15.
Melon-headed whale........... 0, 0, 0........ 0 0 0 No data.
False killer whale........... 0, 0, 0........ 0 0 0 No data.
Pygmy killer whale........... 0, 0, 0........ 0 0 0 No data.
Killer whale................. 0, 0, 0........ 0 0 0 No data.
Long-finned pilot whale...... 3.74, 58.9, 799 799 3.01 No data.
19.1.
Short-finned pilot whale..... 3.74, 58.9, 799 799 3.71 No data.
19.1.
Harbor porpoise.............. 0, 0, 0........ 0 0 0 No data.
----------------------------------------------------------------------------------------------------------------
\1\ Except where noted, densities are the mean values for the shallow (<100 m), intermediate (100-1,000 m), and
deep (>1,000 m) water stratum in the survey area calculated from the SERDP SDSS NODES summer model (Read et
al., 2009) as presented in Table 3 of Lamont-Doherty's application.
\2\ Modeled take in this table corresponds to the total modeled take over all depth ranges shown in Table 3 of
Lamont-Doherty's application. See Table 3 of their application for their original take estimates by shallow,
intermediate, and deep strata. See the addendum to their application for revised take estimates based on
modifications to the tracklines to reduce the total ensonified area by 36.4 percent (i.e., 41,170 km\2\;
15,896 mi\2\).
\3\ Table 1 in this notice lists the stock species abundance estimates used in calculating the percentage of
species/stock.
\4\ Population trend information from Waring et al., 2013. No data = Insufficient data to determine population
trend.
\5\ Density data derived from the Navy's NMSDD. Increases for group size based on pers. com. with Dr. Caroline
Good (2014) and Mr. McLellan (2014) on large whale presence offshore NC.
\6\ Modeled estimate includes the area that is less than 3 km from shore ensonified to greater than or equal to
160 dB (10 km\2\ total).
Encouraging and Coordinating Research
Lamont-Doherty would coordinate the planned marine mammal
monitoring program associated with the seismic survey in the Atlantic
Ocean with applicable U.S. agencies.
Analysis and Preliminary Determinations
Negligible Impact
As explained previously, we have defined the term ``negligible
impact'' to mean ``an impact resulting from the specified activity that
cannot be reasonably expected to, and is not reasonably likely to,
adversely affect the species or stock through effects on annual rates
of recruitment or survival'' (50 CFR 216.103). 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, we consider:
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, Lamont-Doherty'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 anticipated impacts of Lamont-Doherty's survey
activities on marine mammals are temporary behavioral changes due to
avoidance of the area.
The likelihood that marine mammals approaching the survey
area will likely be traveling through or opportunistically foraging
within the vicinity. Marine mammals transiting within the vicinity of
survey operations will be transient as no breeding, calving, pupping,
or nursing areas, or haul-outs, overlap with the survey area.
The low likelihood that North Atlantic right whales would
be exposed to sound levels greater than or equal to 160 dB re: 1 [mu]Pa
due to the requirement that the Langseth crew must shutdown the
airgun(s) immediately if observers detect this species, at any distance
from the vessel.
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
[[Page 44575]]
survey area during the operation of the airgun(s) to avoid acoustic
harassment;
Our expectation that the seismic survey would have no more
than a temporary and minimal adverse effect on any fish or invertebrate
species that serve as prey species for marine mammals, and the
potential impacts to marine mammal habitat minimal;
The relatively low potential for temporary or permanent
hearing impairment and the likelihood that Lamont-Doherty 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 primarily in the form of avoidance behavior to the
sound source during the conduct of the survey activities. Further, the
additional mitigation measure requiring Lamont-Doherty to increase the
size of the Level A harassment exclusion zones in shallow water will
effect the least practicable impact marine mammals.
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 24 marine mammal species (7 mysticetes and 17
odontocetes) would likely occur in the proposed action area. Of the
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
North Atlantic, blue, fin, humpback, 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, including
the identified habitats for North Atlantic right whales and their
calves.
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.
Specifically, the airgun array moves continuously over 10s of
kilometers daily, as do the animals, making it unlikely that the same
animals would be continuously exposed over multiple consecutive 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 less than a day.
In summary, we expect marine mammals to avoid the survey area,
thereby reducing the risk of exposure and impacts. We do not anticipate
disruption to reproductive behavior and there is no anticipated effect
on annual rates of recruitment or survival of affected marine mammals.
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 Lamont-Doherty's
proposed seismic survey would have a negligible impact on the affected
marine mammal species or stocks.
Small Numbers
As mentioned previously, we estimate that Lamont-Doherty's
activities could potentially affect, by Level B harassment only, 24
species of marine mammals under our jurisdiction. For each species,
these estimates constitute small numbers relative to the population
size. We have provided the 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, we find that Lamont-Doherty'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.
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 Cape Hatteras, September-October 2014'' which
we have posted on our Web site concurrently with the publication of
this notice. We 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. We 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 Lamont-Doherty for conducting a seismic
survey in the Atlantic Ocean offshore Cape Hatteras, NC September 15,
2014 through October 31, 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.
[[Page 44576]]
Incidental Harassment Authorization
We hereby authorize the Lamont-Doherty Earth Observatory (Lamont-
Doherty), 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 Atlantic Ocean offshore
Cape Hatteras, NC September through October, 2014.
1. Effective Dates
This Authorization is valid from September 15 through October 31,
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 Lamont-Doherty's Incidental Harassment
Authorization (Authorization) application and environmental analysis in
the following specified geographic area:
a. In the Atlantic Ocean bounded by the following coordinates: in
the Atlantic Ocean, approximately 17 to 422 kilometers (km) (10 to 262
miles (mi)) off the coast of Cape Hatteras, NC between approximately
32-37[deg] N and approximately 71.5-77[deg] W, as specified in Lamont-
Doherty's application and the National Science Foundation's EA.
3. Species Authorized and Level of Takes
a. This authorization limits the incidental taking of marine
mammals, by Level B harassment only, to the species listed in Table 5
of this notice in the area described in Condition 2(a):
i. 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. an airgun array with a total capacity of 6,600 in\3\ (or
smaller);
ii. a multi-beam echosounder;
iii. a sub-bottom profiler; and
iv. an acoustic Doppler current 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-dB exclusion zone (with buffer) before starting
the airgun subarray (6,600 in\3\ or smaller); and a 180-dB exclusion
zone (with buffer) for the single airgun (40 in\3\). Observers will use
the predicted radius distance for the 180-dB exclusion zone (with
buffer).
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 exclusion zone (with buffer) 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 exclusion zone (with
buffer).
ii. If for any reason the visual observer cannot see the full 180-
dB exclusion zone (with buffer) 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, 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:
[[Page 44577]]
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 exclusion zone (with buffer)
within a period of less than 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
exclusion zone (with buffer), 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
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.
t. To the maximum extent practicable, plan to conduct seismic
surveys (especially when near land) from the coast (inshore) and
proceed towards the sea (offshore) in order to avoid trapping marine
mammals in shallow water.
Mitigation Airgun
u. 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:
[[Page 44578]]
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 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 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; 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 Southeast Regional Stranding Coordinator at
(305) 361-4586. 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).
Lamont-Doherty shall not resume its activities until we are able to
review the circumstances of the prohibited take. We shall work with
Lamont-Doherty to determine what is necessary to minimize the
likelihood of further prohibited take and ensure MMPA compliance.
Lamont-Doherty 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 Lamont-Doherty 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), Lamont-Doherty 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 Southeast Regional Stranding Coordinator at (305) 361-4586. The
report must include the same information identified in the paragraph
above this section. Activities may continue while we review the
circumstances of the incident. We would work with Lamont-Doherty 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 Lamont-Doherty 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), Lamont-Doherty 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 Southeast Regional Stranding Coordinator at (305) 361-4586,
within 24 hours of the discovery. Lamont-Doherty 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. 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
We request comments on our analysis and the draft authorization
proposed Authorization for Lamont-Doherty's activities. Please include
any supporting data or literature citations with your comments to help
inform our final decision on Lamont-Doherty's request for an Incidental
Harassment Authorization.
Dated: July 25, 2014.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2014-17998 Filed 7-30-14; 8:45 am]
BILLING CODE 3510-22-P