Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the South Atlantic Ocean, January to March 2016, 75355-75386 [2015-30333]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 80, Number 230 (Tuesday, December 1, 2015)]
[Notices]
[Pages 75355-75386]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-30333]



[[Page 75355]]

Vol. 80

Tuesday,

No. 230

December 1, 2015

Part III





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 South Atlantic Ocean, January to March 2016; 
System of Records; Notice

Federal Register / Vol. 80 , No. 230 / Tuesday, December 1, 2015 / 
Notices

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XE291


Takes of Marine Mammals Incidental to Specified Activities; 
Marine Geophysical Survey in the South Atlantic Ocean, January to March 
2016

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 (NSF), for an Incidental Harassment Authorization 
(Authorization) to take marine mammals, by harassment only, incidental 
to conducting a marine geophysical (seismic) survey in the South 
Atlantic Ocean, January through March 2016. The proposed dates for this 
action would be early January 2016 through March 31, 2016, to account 
for minor deviations due to logistics and weather. Per the Marine 
Mammal Protection Act, we are requesting comments on our proposal to 
issue an Authorization to Lamont-Doherty to incidentally take, by Level 
B harassment, 38 species of marine mammals during the specified 
activity and to incidentally take, by Level A harassment, 16 species of 
marine mammals. Although considered unlikely, any Level A harassment 
potentially incurred would be expected to be in the form of some 
smaller degree of permanent hearing loss due in part to the required 
monitoring measures for detecting marine mammals and required 
mitigation measures for power downs or shut downs of the airgun array 
if any animal is likely to enter the Level A exclusion zone. NMFS does 
not expect mortality or complete deafness of marine mammals to result 
from this survey.

DATES: NMFS must receive comments and information on or before December 
31, 2015.

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 ITP.Cody@noaa.gov. Please include 0648-XE291 in the subject 
line. Comments sent via email to ITP.Cody@noaa.gov, 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 https://www.nmfs.noaa.gov/pr/permits/incidental/research.htm without change. All Personal Identifying 
Information (for example, name, address, etc.) voluntarily submitted by 
the commenter may be publicly accessible. Do not submit confidential 
business information or otherwise sensitive or protected information.
    To obtain an electronic copy of Lamont-Doherty's application, NSF's 
draft environmental analysis, NMFS' draft Environmental Assessment, and 
a list of the references used in this document, write to the previously 
mentioned address, telephone the contact listed here (see FOR FURTHER 
INFORMATION CONTACT), or visit the internet at: https://www.nmfs.noaa.gov/pr/permits/incidental/research.htm.
    Information in Lamont-Doherty's application, NSF's draft 
environmental analysis, NMFS' draft Environmental Assessment and this 
notice collectively provide the environmental information related to 
the proposed issuance of the Authorization for public review and 
comment.

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

SUPPLEMENTARY INFORMATION:

Background

    Section 101(a)(5)(D) of the Marine Mammal Protection Act of 1972, 
as amended (MMPA; 16 U.S.C. 1361 et seq.) directs the Secretary of 
Commerce to allow, upon request, the incidental, but not intentional, 
taking of small numbers of marine mammals of a species or population 
stock, by U.S. citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if, after 
NMFS provides a notice of a proposed authorization to the public for 
review and comment: (1) NMFS makes certain findings; and (2) the taking 
is limited to harassment.
    An Authorization shall be granted for the incidental taking of 
small numbers of marine mammals if NMFS finds that the taking will have 
a negligible impact on the species or stock(s), and will not have an 
unmitigable adverse impact on the availability of the species or 
stock(s) for subsistence uses (where relevant). The Authorization must 
also set forth the permissible methods of taking; other means of 
effecting the least practicable adverse impact on the species or stock 
and its habitat (i.e., mitigation); and requirements pertaining to the 
monitoring and reporting of such taking. NMFS has defined ``negligible 
impact'' in 50 CFR 216.103 as ``an impact resulting from the specified 
activity that cannot be reasonably expected to, and is not reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival.''
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment].

Summary of Request

    On July 29, 2015, NMFS received an application from Lamont-Doherty 
requesting that NMFS issue an Authorization for the take of marine 
mammals, incidental to Texas A&M University and the University of Texas 
conducting a seismic survey in the South Atlantic Ocean, January 
through March 2016. Following the initial application submission, 
Lamont-Doherty submitted a revised application with revised take 
estimates. NMFS considered the revised application adequate and 
complete on October 30, 2015.
    Lamont-Doherty proposes to conduct a two-dimensional (2-D), seismic 
survey on the R/V Marcus G. Langseth (Langseth), a vessel owned by NSF 
and operated on its behalf by Columbia University's Lamont-Doherty in 
international waters in the South Atlantic Ocean approximately 1,938 
kilometers (km) (1,232 miles [mi]) southeast of the west coast of 
Brazil for approximately 22 days. 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 
array. We anticipate that take, by Level B harassment, of 38 species of 
marine mammals could result from the specified activity. Although 
unlikely, NMFS also anticipates that a small level of take by Level A 
harassment of 16 species of marine

[[Page 75357]]

mammals could occur during the proposed survey.

Description of the Specified Activity

Overview

    Lamont-Doherty plans to use one source vessel, the Langseth, an 
array of 36 airguns as the energy source, a receiving system of seven 
ocean bottom seismometers (OBS), and a single 8-kilometer (km) 
hydrophone streamer. In addition to the operations of the airguns, 
Lamont-Doherty intends to operate a multibeam echosounder and a sub-
bottom profiler continuously throughout the proposed survey. However, 
Lamont-Doherty will not operate the multibeam echosounder and sub-
bottom profiler during transits to and from the survey area and in 
between transits to each of the five OBS tracklines (i.e., when the 
airguns are not operating).
    The purpose of the survey is to collect and analyze seismic 
refraction data from the Mid-Atlantic Ridge westward to the Rio Grande 
Rise to study the evolution of the South Atlantic Ocean crust on 
million-year timescales and the evolution and stability of low-
spreading ridges over time. NMFS refers the public to Lamont-Doherty's 
application (see page 3) for more detailed information on the proposed 
research objectives.

Dates and Duration

    Lamont-Doherty proposes to conduct the seismic survey for 
approximately 42 days, which includes approximately 22 days of seismic 
surveying with 10 days of OBS deployment and retrieval. The proposed 
study (e.g., equipment testing, startup, line changes, repeat coverage 
of any areas, and equipment recovery) would include approximately 528 
hours of airgun operations (i.e., 22 days over 24 hours). Some minor 
deviation from Lamont-Doherty's requested dates of January through 
March 2016 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 early 
January through March 31, 2016.
    NMFS refers 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 proposed seismic survey in 
the South Atlantic Ocean, located approximately between 10-35[deg] W, 
27-33[deg] S (see Figure 1). Water depths in the survey area range from 
approximately 1,150 to 4,800 meters (m) (3,773 feet [ft] to 2.98 miles 
[mi]).

Principal and Collaborating Investigators

    The proposed survey's principal investigators are Drs. R. Reece and 
R. Carlson (Texas A&M University) and Dr. G. Christeson (University of 
Texas at Austin).
BILLING CODE 3510-22-C
[GRAPHIC] [TIFF OMITTED] TN01DE15.056

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BILLING CODE 3510-22-P

Detailed Description of the Specified Activities

Transit Activities

    The Langseth would depart and return from Montevideo, Uruguay, and 
transit to the survey area. Some minor deviations with the transit 
schedule and port locations are possible depending on logistics and 
weather.

Vessel Specifications

    The survey would involve one source vessel, the R/V Langseth. The 
Langseth, owned by NSF 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 that drive two propellers. 
Each propeller has four blades and the shaft typically rotates at 750 
revolutions per minute. The vessel also has an 800-hp bowthruster, 
which is off during seismic acquisition.
    The 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, its turning rate is limited to five degrees per minute. 
Thus, the Langseth's maneuverability is limited during operations while 
it tows the streamer.
    The vessel also has an observation tower from which protected 
species visual observers (observers) would 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.

Data Acquisition Activities

    The proposed survey would cover a total of approximately 3,263 km 
(2,028 mi) of transect lines. The proposed survey is one continuous 
transect line with transect lines that cross the main line at six 
locations.
    During the survey, the Langseth would deploy 36 airguns as an 
energy source with a total volume of 6,600 cubic inches (in\3\). The 
receiving system would consist of seven OBSs deployed at each 
perpendicular trackline site and a single 8-km (5-mi) hydrophone 
streamer. As the Langseth tows the airgun array along the survey lines, 
the OBSs and hydrophone streamer would receive the returning acoustic 
signals and transfer the data to the on-board processing system.

Seismic Airguns

    The airguns are a mixture of Bolt 1500LL and Bolt 1900LLX airguns 
ranging in size from 40 to 220 in\3\, with a firing pressure of 1,950 
pounds per square inch. The dominant frequency components range from 
zero to 188 Hertz (Hz).
    During the survey, Lamont-Doherty would plan to use the full array 
with most of the airguns in inactive mode. The Langseth would tow the 
array at a depth of 9 m (29.5 ft) resulting in a shot interval of 
approximately 65 seconds (s) (approximately 150 m; 492 ft) for the leg 
with the OBS lines and a shot interval of approximately 22 s 
(approximately 50 m; 164 ft) for the multichannel seismic survey lines 
with the hydrophone streamer. During acquisition the airguns will emit 
a brief (approximately 0.1 s) pulse of sound. During the intervening 
periods of operations, the airguns are silent.
    Airguns function by venting high-pressure air into the water, which 
creates an air bubble. The pressure signature of an individual airgun 
consists of a sharp rise and then fall in pressure, followed by several 
positive and negative pressure excursions caused by the oscillation of 
the resulting air bubble. The oscillation of the air bubble transmits 
sounds downward through the seafloor, and there is also a reduction in 
the amount of sound transmitted in the near horizontal direction. The 
airgun array also emits sounds that travel horizontally toward non-
target areas.
    The nominal source levels of the airgun subarrays on the Langseth 
range from 240 to 247 decibels (dB) re: 1 
[mu]Pa(peak to peak). (We express sound pressure level as 
the ratio of a measured sound pressure and a reference pressure level. 
The commonly used unit for sound pressure is dB and the commonly used 
reference pressure level in underwater acoustics is 1 microPascal 
([mu]Pa)). Briefly, the effective source levels for horizontal 
propagation are lower than source levels for downward propagation. We 
refer the reader to Lamont-Doherty's Authorization application and 
NSF's Environmental Analysis for additional information on downward and 
horizontal sound propagation related to the airgun's source levels.

Additional Acoustic Data Acquisition Systems

    Multibeam Echosounder: The Langseth will operate a Kongsberg EM 122 
multibeam echosounder concurrently during airgun operations to map 
characteristics of the ocean floor. However, as stated earlier, Lamont-
Doherty will not operate the multibeam echosounder during transits to 
and from the survey areas (i.e., when the airguns are not operating).
    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. As with the case of the echosounder, Lamont-Doherty 
will not operate the sub-bottom profiler during transits to and from 
the survey areas (i.e., when the airguns are not operating).
    The profiler is capable of reaching depths of 10,000 m (6.2 mi). 
The dominant frequency component is 3.5 kHz and a hull-mounted 
transducer on the vessel directs the beam downward in a 27[deg] cone. 
The power output is 10 kilowatts (kW), but the actual maximum radiated 
power is three kilowatts or 222 dB re: 1 [mu]Pa. The ping duration is 
up to 64 ms with a pulse interval of one second, but a common mode of 
operation is to broadcast five pulses at 1-s intervals followed by a 5-
s pause.
    Ocean Bottom Seismometers: The Langseth would deploy a total of 
seven OBS at a 10-km (6.2-mi) spacing interval at each crossline site 
and would carry out operations in a west-to-east transit line. For each 
OBS profile site, the

[[Page 75359]]

Langseth crew would deploy seven OBSs on the sea floor, would survey 
the line, and then would recover the source array and the OBSs before 
moving to the next line.
    Lamont-Doherty proposes to use one of two types of OBSs: The Woods 
Hole Oceanographic Institute (WHOI) or the Scripps Institution of 
Oceanography (SIO) OBS.
    The WHOI D2 OBS is approximately 0.9 m (2.9 ft) high with a maximum 
diameter of 50 centimeters (cm) (20 inches [in]). An anchor, made of a 
rolled steel bar grate that measures approximately 2.5 by 30.5 by 38.1 
cm (1 by 12 by 15 in) and weighs 23 kilograms (kg) (51 pounds [lbs]) 
would anchor the seismometer to the seafloor. The SIO L-Cheapo OBS is 
approximately 0.9 m (2.9 ft) high with a maximum diameter of 97 
centimeters (cm) (3.1 ft). The SIO anchors consist of 36-kg (79-lb) 
iron gates and measure approximately 7 by 91 by 91.5 cm (3 by 36 by 36 
inches).
    After the Langseth completes the proposed seismic survey, an 
acoustic signal would trigger the release of each seismometer from the 
ocean floor. The Langseth's acoustic release transponder, located on 
the vessel, communicates with the seismometer at a frequency of 9 to13 
kilohertz (kHz). The maximum source level of the release signal is 242 
dB re: 1 [mu]Pa with an 8-millisecond pulse length. The received signal 
activates the seismometer's double burn-wire release assembly which 
then releases the seismometer from the anchor. The seismometer then 
floats to the ocean surface for retrieval by the Langseth. The steel 
grate anchors from each of the seismometers would remain on the 
seafloor.
    The Langseth crew would deploy 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 mammal.
    Hydrophone Streamer: Lamont-Doherty would deploy the single 
hydrophone streamer for multichannel operations after concluding the 
OBS operations. As the Langseth tows the airgun array along the survey 
lines, the streamer transfers the data to the on-board processing 
system.

Description of Marine Mammals in the Area of the Specified Activity

    Table 1 in this notice provides the following: All marine mammal 
species with possible or confirmed occurrence in the proposed activity 
area; information on those species' regulatory status under the MMPA 
and the Endangered Species Act of 1973 (16 U.S.C. 1531 et seq.); 
abundance; local occurrence and range; and seasonality in the proposed 
activity area. Based on the best available information, NMFS expects 
that there may be a potential for certain cetacean and pinniped species 
to occur within the survey area (i.e., potentially be taken) and have 
included additional information for these species in Table 1 of this 
notice. NMFS will carry forward analyses on the species listed in Table 
1 later in this document.

 Table 1--General Information on Marine Mammals That Could Potentially Occur in the Proposed Survey Areas Within
                                            the South Atlantic Ocean
                                          [January through March 2016]
----------------------------------------------------------------------------------------------------------------
                                                         Species
             Species              Regulatory status 1   abundance     Local occurrence          Season \5\
                                           2               \3\         and range \4\
----------------------------------------------------------------------------------------------------------------
Antarctic minke whale             MMPA-NC, ESA-NL....  \6\ 515,000  Uncommon, shelf,     Winter.
 (Balaenoptera bonaerensis).                                         pelagic.
Blue whale (B. musculus)........  MMPA-D, ESA-EN.....    \7\ 2,300  Rare, coastal,       Winter.
                                                                     slope, pelagic.
Bryde's whale (B. edeni)........  MMPA-NC, ESA-NL....   \8\ 43,633  Rare, coastal,       Winter.
                                                                     pelagic.
Common (dwarf) minke whale (B.    MMPA-NC, ESA-NL....  \6\ 515,000  Uncommon, shelf,     Winter.
 acutorostrata).                                                     pelagic.
Fin whale (B. physalus).........  MMPA-D, ESA-EN.....   \9\ 22,000  Uncommon, Coastal,   Fall.
                                                                     pelagic.
Humpback whale (Megaptera         MMPA-D, ESA-EN.....   \10\42,000  Uncommon, Coastal,   Winter.
 novaeangliae).                                                      shelf, pelagic.
Sei whale (B. borealis).........  MMPA-D, ESA-EN.....  \11\ 10,000  Uncommon, Shelf      Winter.
                                                                     edges, pelagic.
Southern right whale (Eubalaena   MMPA-D, ESA-EN.....  \12\ 12,000  Uncommon, Coastal,   Winter.
 australis).                                                         shelf.
Sperm whale (Physeter             MMPA-D, ESA-EN.....         \13\  Uncommon, Slope,     Winter.
 macrocephalus).                                           355,000   pelagic.
Dwarf sperm whale (Kogia sima)..  MMPA-NC, ESA-NL....        3,785  Rare, Shelf, slope,  Winter.
                                                                     pelagic.
Pygmy sperm whale (K. breviceps)  MMPA-NC, ESA-NL....        3,785  Rare, Shelf, slope,  Winter.
                                                                     pelagic.
Cuvier's beaked whale (Ziphius    MMPA-NC, ESA-NL....         \14\  Uncommon, Slope....  Winter.
 cavirostris).                                             599,300
Andrew's beaked whale             MMPA-NC, ESA-NL....         \14\  Rare, Pelagic......  Winter.
 (Mesoplodon bowdoini).                                    599,300
Arnoux's beaked whale (Berardius  MMPA-NC, ESA-NL....         \14\  Rare, Pelagic......  Winter.
 arnuxii).                                                 599,300
Blainville's beaked whale (M.     MMPA-NC, ESA-NL....         \14\  Rare, Slope,         Winter.
 densirostris).                                            599,300   pelagic.
Gervais' beaked whale (M.         MMPA-NC, ESA-NL....         \14\  Rare, pelagic......  Winter.
 europaeus).                                               599,300
Gray's beaked whale (M. grayi)..  MMPA-NC, ESA-NL....         \14\  Rare, Pelagic......  Winter.
                                                           599,300
Hector's beaked whale (M.         MMPA-NC, ESA-NL....         \14\  Rare, pelagic......  Winter.
 hectori).                                                 599,300
Shepherd's beaked whale           MMPA-NC, ESA-NL....         \14\  Rare, pelagic......  Winter.
 (Tasmacetus shepherdi).                                   599,300
Strap-toothed beaked whale (M.    MMPA-NC, ESA-NL....         \14\  Rare, pelagic......  Winter.
 layardii).                                                599,300
True's beaked whale (M. mirus)..  MMPA-NC, ESA-NL....        7,092  Rare, pelagic......  Winter.
Southern bottlenose whale         MMPA-NC, ESA-NL....         \14\  Rare, Coastal,       Winter.
 (Hyperoodon planifrons).                                  599,300   shelf, pelagic.
Bottlenose dolphin (Tursiops      MMPA-NC, ESA-NL....         \15\  Uncommon, Coastal,   Winter.
 truncatus).                                               600,000   pelagic.
Rough-toothed dolphin (Steno      MMPA-NC, ESA-NL....          271  Uncommon, shelf,     Winter.
 bredanensis).                                                       pelagic.
Pantropical spotted dolphin       MMPA-NC, ESA-NL....        3,333  Uncommon, Coastal,   Winter.
 (Stenella attennuata).                                              slope, pelagic.
Striped dolphin (S.               MMPA-NC, ESA-NL....       54,807  Rare, Pelagic......  Winter.
 coeruleoalba).
Fraser's dolphin (Lagenodelphis   MMPA-NC, ESA-NL....         \16\  Uncommon, Pelagic..  Winter.
 hosei).                                                   289,000
Spinner dolphin (Stenella         MMPA-NC, ESA-NL....         \16\  Rare, Pelagic......  Winter.
 longirostris).                                          1,200,000
Atlantic spotted dolphin (S.      MMPA-NC, ESA-NL....       44,715  Uncommon, Pelagic..  Winter.
 frontalis).

[[Page 75360]]

 
Clymene dolphin (S. clymene)....  MMPA-NC, ESA-NL....        6,215  Rare, Pelagic......  Winter.
Risso's dolphin (Grampus          MMPA-NC, ESA-NL....       20,692  Uncommon, Pelagic..  Winter.
 griseus).
Long-beaked common dolphin        MMPA-NC, ESA-NL....  \17\ 20,000  Rare, Coastal......  Winter.
 (Delphinus capensis).
Short-beaked common dolphin       MMPA-NC, ESA-NL....      173,486  Uncommon, Coastal,   Winter.
 (Delphinus delphis).                                                shelf.
Southern right whale dolphin      MMPA-NC, ESA-NL....      Unknown  Uncommon, Coastal,   Winter.
 (Lissodelphis peronii).                                             shelf.
Melon-headed whale                MMPA-NC, ESA-NL....  \18\ 50,000  Uncommon, Coastal,   Winter.
 (Peponocephala electra).                                            shelf, pelagic.
Pygmy killer whale (Feresa        MMPA-NC, ESA-NL....        3,585  Uncommon, Coastal,   Winter.
 attenuate).                                                         shelf, pelagic.
False killer whale (Pseudorca     MMPA-NC, ESA-NL....          442  Rare, Pelagic......  Winter.
 crassidens).
Killer whale (Orcinus orca).....  MMPA-NC, ESA-NL....  \19\ 50,000  Uncommon, Coastal,   Winter.
                                                                     pelagic.
Long-finned pilot whale           MMPA-NC, ESA-NL....         \14\  Uncommon, Pelagic..  Winter.
 (Globicephala melas).                                     200,000
Short-finned pilot whale          MMPA-NC, ESA-NL....         \14\  Uncommon, Pelagic..  Winter.
 (Globicephala macrorhynchus).                             200,000
Southern Elephant Seal (Mirounga  MMPA-NC, ESA-NL....         \20\  Rare, Coastal......  Winter.
 leonina).                                                 650,000
Subantarctic fur seal             MMPA-NC, ESA-NL....         \21\  Uncommon, Pelagic..  Winter.
 (Arctocephalus tropicalis).                               310,000
----------------------------------------------------------------------------------------------------------------
\2\ ESA: EN = Endangered, T = Threatened, DL = Delisted, NL = Not listed.
\3\ Except where noted abundance information obtained from NOAA Technical Memorandum NMFS-NE-231, U.S. Atlantic
  and Gulf of Mexico Marine Mammal Stock Assessments-2014 (Waring et al., 2015) and the Draft 2015 U.S. Atlantic
  and Gulf of Mexico Marine Mammal Stock Assessments (in review, 2015). NA = Not available.
\4\ Occurrence and range information available from the International Union for the Conservation of Nature
  (IUCN).
\5\ NA= Not available due to limited information on that species' seasonal occurrence in the proposed area.
\6\ Best estimate from the International Whaling Commission's (IWC) estimate for the minke whale population
  (Southern Hemisphere, 2004).
\7\ Best estimate from the IWC's estimate for the blue whale population (Southern Hemisphere, 1998).
\8\ Estimate from IUCN Web page for Bryde's whales. Southern Hemisphere: Southern Indian Ocean (13,854); western
  South Pacific (16,585); and eastern South Pacific (13,194) (IWC, 1981).
\9\ Best estimate from the IWC's estimate for the fin whale population (East Greenland to Faroes, 2007).
\10\ Best estimate from the IWC's estimate for the humpback whale population (Southern Hemisphere, partial
  coverage of Antarctic feeding grounds, 2007).
\11\ Estimate from the IUCN Web page for sei whales (IWC, 1996).
\12\ Best estimate from the IWC's estimate for the southern right whale population (Southern Hemisphere, 2009).
\13\ Whitehead, (2002).
\14\ Abundance estimates for beaked, southern bottlenose, and pilot whales south of the Antarctic Convergence in
  January (Kasamatsu and Joyce, 1995).
\15\ Wells and Scott, (2009).
\16\ Jefferson et al., (2008).
\17\ Cockcroft and Peddemors, (1990).
\18\ Estimate from the IUCN Web page for melon-headed whales (IUCN, 2015).
\19\ Estimate from the IUCN Web page for killer whales (IUCN, 2015).
\20\ Estimate from the IUCN Web page for southern elephant seals (IUCN, 2015).
\21\ Arnoud, (2009).

    NMFS refers the public to Lamont-Doherty's application, NSF's draft 
environmental analysis (see ADDRESSES), NOAA Technical Memorandum NMFS-
NE-231, U.S. Atlantic and Gulf of Mexico Marine Mammal Stock 
Assessments-2014 (Waring et al., 2015); and the Draft 2015 U.S. 
Atlantic and Gulf of Mexico Marine Mammal Stock Assessments (in review, 
2015) available online at: https://www.nmfs.noaa.gov/pr/sars/species.htm 
for further information on the biology and local distribution of these 
species.

Potential Effects of the Specified Activities on Marine Mammals

    This section includes a summary and discussion of the ways that 
components (e.g., seismic airgun operations, vessel movement) of the 
specified activity may impact marine mammals. The ``Estimated Take by 
Incidental Harassment'' section later in this document will include a 
quantitative analysis of the number of individuals that NMFS expects to 
be taken by this activity. The ``Negligible Impact Analysis'' section 
will include the analysis of how this specific proposed activity would 
impact marine mammals and will consider the content of this section, 
the ``Estimated Take by Incidental Harassment'' section, the ``Proposed 
Mitigation'' section, and the ``Anticipated Effects on Marine Mammal 
Habitat'' section to draw conclusions regarding the likely impacts of 
this activity on the reproductive success or survivorship of 
individuals and from that on the affected marine mammal populations or 
stocks.
    NMFS intends 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. Operating active acoustic sources, such as 
airgun arrays, has the potential for adverse effects on marine mammals. 
The majority of anticipated impacts would be from the use of the airgun 
array.

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.,

[[Page 75361]]

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 25 kHz (extended from 22 kHz based on data indicating that some 
mysticetes can hear above 22 kHz; Au et al., 2006; Lucifredi and Stein, 
2007; Ketten and Mountain, 2009; Tubelli et al., 2012);
     Mid-frequency cetaceans (32 species of dolphins, six 
species of larger toothed whales, and 19 species of beaked and 
bottlenose whales): Functional hearing estimates occur between 
approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (eight species of true porpoises, 
six species of river dolphins, Kogia, the franciscana, and four species 
of cephalorhynchids): Functional hearing estimates occur between 
approximately 200 Hz and 180 kHz; and
     Pinnipeds in water: Phocid (true seals) functional hearing 
estimates occur between approximately 75 Hz and 100 kHz (Hemila et al., 
2006; Mulsow et al., 2011; Reichmuth et al., 2013) and otariid (seals 
and sea lions) functional hearing estimates occur between approximately 
100 Hz to 40 kHz.
    Approximately 42 marine mammal species (8 mysticetes, 32 
odontocetes, and two pinnipeds) would likely occur in the proposed 
action area. Table 2 presents the classification of these species into 
their respective functional hearing group. NMFS consider a species' 
functional hearing group when analyzing the effects of exposure to 
sound on marine mammals.

 Table 2--Classification of Marine Mammals That Could Potentially Occur
  in the Proposed Survey Areas Within the South Atlantic Ocean (January
             through March 2016) by Functional Hearing Group
                         [Southall et al., 2007]
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Low Frequency Hearing Range.......  Antarctic minke, blue, Bryde's,
                                     common (dwarf) minke, fin,
                                     humpback, Sei, and Southern right
                                     whale
Mid-Frequency Hearing Range.......  Sperm whale; Cuvier's, Andrew's,
                                     Arnoux's, Blainville's, Gervais',
                                     Gray's, Hector's, Shepherd's, strap-
                                     toothed, and True's beaked whale;
                                     Southern bottlenose whale;
                                     bottlenose, rough-toothed,
                                     pantropical spotted, striped,
                                     Fraser's dolphin spinner, Atlantic
                                     spotted, Clymene, Risso's, long-
                                     beaked common, short-beaked common,
                                     and Southern right whale dolphin;
                                     melon-headed whale; pygmy killer
                                     whale; false killer whale; killer
                                     whale, long-finned pilot whale; and
                                     short-finned pilot whale
High Frequency Hearing Range......  Dwarf sperm whale and pygmy sperm
                                     whale
Pinnipeds in Water Hearing Range..  Southern elephant seal and
                                     Subantarctic fur seal
------------------------------------------------------------------------

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).
    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 per hour) for humpback and sperm whales according to the 
airgun array's operational status (i.e., active versus silent).
    Bain and Williams (2006) examined the effects of a large airgun 
array (maximum total discharge volume of 1,100 in\3\) on six species in 
shallow waters off British Columbia and Washington: Harbor seal (Phoca 
vitulina), California sea lion (Zalophus californianus), Steller sea 
lion (Eumetopias jubatus), gray whale (Eschrichtius robustus), Dall's 
porpoise (Phocoenoides dalli), and harbor porpoise (Phocoena phocoena). 
Harbor porpoises showed reactions at received levels less than 155 dB 
re: 1 [mu]Pa at a distance of greater than 70 km (43 mi) from the 
seismic source (Bain and Williams, 2006). However, the tendency for 
greater responsiveness by harbor porpoise is consistent with their 
relative responsiveness to boat traffic and some other acoustic sources 
(Richardson, et al., 1995; Southall, et al., 2007). In contrast, the 
authors reported that gray whales seemed to tolerate exposures to sound 
up to approximately 170 dB re: 1 [mu]Pa (Bain and Williams, 2006) and

[[Page 75362]]

Dall's porpoises occupied and tolerated areas receiving exposures of 
170-180 dB re: 1 [mu]Pa (Bain and Williams, 2006; Parsons, et al., 
2009). The authors observed several gray whales that moved away from 
the airguns toward deeper water where sound levels were higher due to 
propagation effects resulting in higher noise exposures (Bain and 
Williams, 2006). However, it is unclear whether their movements 
reflected a response to the sounds (Bain and Williams, 2006). Thus, the 
authors surmised that the lack of gray whale responses to higher 
received sound levels were ambiguous at best because one expects the 
species to be the most sensitive to the low-frequency sound emanating 
from the airguns (Bain and Williams, 2006).
    Pirotta et al. (2014) observed short-term responses of harbor 
porpoises to a two-dimensional (2-D) seismic survey in an enclosed bay 
in northeast Scotland which did not result in broad-scale displacement. 
The harbor porpoises that remained in the enclosed bay area reduced 
their buzzing activity by 15 percent during the seismic survey 
(Pirotta, et al., 2014). Thus, the authors suggest that animals exposed 
to anthropogenic disturbance may make trade-offs between perceived 
risks and the cost of leaving disturbed areas (Pirotta, et al., 2014).

Masking

    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).
    The term masking refers to the inability of an animal to recognize 
the occurrence of an acoustic stimulus because of interference of 
another acoustic stimulus (Clark et al., 2009). Thus, masking is the 
obscuring of sounds of interest by other sounds, often at similar 
frequencies. It 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.
    Introduced underwater sound may, through masking, may more 
specifically 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).
    Marine mammals are thought to be able to compensate for 
communication 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). Other studies reported 
that some North Atlantic right whales exposed to high shipping noise 
increased call frequency (Parks et al., 2007) and some humpback whales 
responded 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).
    Studies have shown that some baleen and toothed whales continue 
calling in the presence of seismic pulses, and some researchers have 
heard these calls between the seismic pulses (e.g., Richardson et al., 
1986; McDonald et al., 1995; Greene et al., 1999; Nieukirk et al., 
2004; Smultea et al., 2004; Holst et al., 2005a, 2005b, 2006; and Dunn 
and Hernandez, 2009).
    In contrast, 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, NMFS 
is aware of one report that observed sperm whales ceasing calls when 
exposed to pulses from a very distant seismic ship (Bowles et al., 
1994). However, more recent studies have found that sperm whales 
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).
    Risch et al. (2012) documented reductions in humpback whale 
vocalizations in the Stellwagen Bank National Marine Sanctuary 
concurrent with transmissions of the Ocean Acoustic Waveguide Remote 
Sensing (OAWRS) low-frequency fish sensor system at distances of 200 km 
(124 mi) from the source. The recorded OAWRS produced series of 
frequency modulated pulses and the signal received levels ranged from 
88 to 110 dB re: 1 [mu]Pa (Risch, et al., 2012). The authors 
hypothesized that individuals did not leave the area but instead ceased 
singing and noted that the duration and frequency range of the OAWRS 
signals (a novel sound to the whales) were similar to those of natural 
humpback whale song components used during mating (Risch et al., 2012). 
Thus, the novelty of the sound to humpback whales in the study area 
provided a compelling contextual probability for the observed effects 
(Risch et al., 2012). However, the authors did not state or imply that 
these changes had long-term effects on individual animals or 
populations (Risch et al., 2012).
    Several studies have also 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 odontocete communication are 
predominantly at much higher frequencies than the dominant components 
of airgun sounds, thus limiting the potential for masking in those 
species.
    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. Odontocete conspecifics may readily detect structured signals, 
such as the echolocation click sequences of small toothed whales 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

[[Page 75363]]

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. 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).
    Types of behavioral reactions can include the following: 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 water from haulouts or rookeries).
    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 (e.g., Lusseau and 
Bejder, 2007; Weilgart, 2007). Examples of behavioral modifications 
that could impact growth, survival, or reproduction include:
     Drastic changes in diving/surfacing patterns (such as 
those associated with beaked whale stranding related to exposure to 
military mid-frequency tactical sonar);
     Permanent habitat abandonment due to loss of desirable 
acoustic environment; and
     Disruption of feeding or social interaction resulting in 
significant energetic costs, inhibited breeding, or cow-calf 
separation.
    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).

Baleen Whales

    Studies have shown that underwater sounds from seismic activities 
are often readily detectable by baleen whales in the water at distances 
of many kilometers (Castellote et al., 2012 for fin whales). Many 
studies have also shown that marine mammals at distances more than a 
few kilometers away often show no apparent response when exposed to 
seismic activities (e.g., Madsen & Mohl, 2000 for sperm whales; Malme 
et al., 1983, 1984 for gray whales; and Richardson et al., 1986 for 
bowhead whales). Other studies have shown that marine mammals continue 
important behaviors in the presence of seismic pulses (e.g., Dunn & 
Hernandez, 2009 for blue whales; Greene Jr. et al., 1999 for bowhead 
whales; Holst and Beland, 2010; Holst and Smultea, 2008; Holst et al., 
2005; Nieukirk et al., 2004; Richardson, et al., 1986; Smultea et al., 
2004).
    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 
visibility, sighting rates for mysticetes (mainly fin and sei whales) 
were similar when large arrays of airguns were shooting versus 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).
    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). The authors observed that 
baleen whales as a group were significantly farther from the vessel 
during seismic compared with non-seismic periods. Moreover, the authors 
observed that the whales swam away more often from the operating 
seismic vessel (Moulton and Holst, 2010). Initial sightings of blue and 
minke whales were significantly farther from the vessel during seismic 
operations compared to non-seismic periods and the authors observed the 
same trend for fin whales (Moulton and Holst, 2010). Also, the authors 
observed that minke whales most often swam away from the vessel when 
seismic operations were underway (Moulton and Holst, 2010).

Blue Whales

    McDonald et al. (1995) tracked blue whales relative to a seismic 
survey with a 1,600 in\3\ airgun array. One whale started its call 
sequence within 15 km (9.3 mi) from the source, then followed a pursuit 
track that decreased its distance to the vessel where it stopped 
calling at a range of 10 km (6.2 mi) (estimated received level at 143 
dB re: 1 [mu]Pa (peak-to-peak)). After that point, the ship increased 
its distance from the whale which continued a new call sequence after 
approximately one hour

[[Page 75364]]

and 10 km (6.2 mi) from the ship. The authors reported that the whale 
had taken a track paralleling the ship during the cessation phase but 
observed the whale moving diagonally away from the ship after 
approximately 30 minutes continuing to vocalize. Because the whale may 
have approached the ship intentionally or perhaps was unaffected by the 
airguns, the authors concluded that there was insufficient data to 
infer conclusions from their study related to blue whale responses 
(McDonald, et al., 1995).
    Dunn and Hernandez (2009) tracked blue whales in the eastern 
tropical Pacific Ocean near the northern East Pacific Rise using 25 
ocean-bottom-mounted hydrophones and ocean bottom seismometers during 
the conduct of an academic seismic survey by the R/V Maurice Ewing in 
1997. During the airgun operations, the authors recorded the airgun 
pulses across the entire seismic array which they determined were 
detectable by eight whales that had entered into the area during a 
period of airgun activity (Dunn and Hernandez, 2009). The authors were 
able to track each whale call-by-call using the B components of the 
calls and examine the whales' locations and call characteristics with 
respect to the periods of airgun activity. The authors tracked the blue 
whales from 28 to 100 km (17 to 62 mi) away from active air-gun 
operations, but did not observe changes in call rates and found no 
evidence of anomalous behavior that they could directly ascribed to the 
use of the airguns (Dunn and Hernandez, 2009; Wilcock et al., 2014). 
Further, the authors state that while the data do not permit a thorough 
investigation of behavioral responses, they observed no correlation in 
vocalization or movement with the concurrent airgun activity and 
estimated that the sound levels produced by the Ewing's airguns were 
approximately less than 145 dB re: 1 [mu]Pa (Dunn and Hernandez, 2009).

Fin Whales

    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.

Gray Whales

    A few studies have documented reactions of migrating and feeding 
(but not wintering) gray whales (Eschrichtius robustus) to seismic 
surveys. Malme et al. (1986, 1988) studied the responses of feeding 
eastern Pacific gray whales to pulses from a single 100-in\3\ airgun 
off St. Lawrence Island in the northern Bering Sea. They estimated, 
based on small sample sizes, that 50 percent of feeding gray whales 
stopped feeding at an average received pressure level of 173 dB re: 1 
[mu]Pa on an (approximate) root mean square basis, and that 10 percent 
of feeding whales interrupted feeding at received levels of 163 dB re: 
1 [micro]Pa. Those findings were generally consistent with the results 
of experiments conducted on larger numbers of gray whales that were 
migrating along the California coast (Malme et al., 1984; Malme and 
Miles, 1985), and western Pacific gray whales feeding off Sakhalin 
Island, Russia (Wursig et al., 1999; Gailey et al., 2007; Johnson et 
al., 2007; Yazvenko et al., 2007a, 2007b), along with data on gray 
whales off British Columbia (Bain and Williams, 2006).
    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, 2014). The western 
Pacific gray whale population did not appear affected by a seismic 
survey in its feeding ground during a previous year (Johnson et al., 
2007). Similarly, bowhead whales (Balaena mysticetus) 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, 2014). 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.

Humpback Whales

    McCauley et al. (1998, 2000) 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 (peak-to-peak). 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

[[Page 75365]]

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).

Toothed Whales

    Few systematic data are available describing reactions of toothed 
whales to noise pulses. However, systematic work on sperm whales is 
underway (e.g., Gordon et al., 2006; Madsen et al., 2006; Winsor and 
Mate, 2006; Jochens et al., 2008; Miller et al., 2009) and 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). Reactions 
of toothed whales to large arrays of airguns are variable and, at least 
for delphinids, seem to be confined to a smaller radius than has been 
observed for mysticetes.

Delphinids

    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, there have been indications that small toothed whales 
sometimes move away or maintain a somewhat greater distance from the 
vessel when a large array of airguns is operating than when it is 
silent (e.g., Goold, 1996a,b,c; 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 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 (pk-pk level > 200 
dB re 1 [mu]Pa) before exhibiting aversive behaviors.

Killer Whales

    Observers stationed on seismic vessels operating off the United 
Kingdom from 1997-2000 have provided data on the occurrence and 
behavior of various toothed whales exposed to seismic pulses (Stone, 
2003; Gordon et al., 2004). The studies note that killer whales were 
significantly farther from large airgun arrays during periods of active 
airgun operations compared with periods of silence. The displacement of 
the median distance from the array was approximately 0.5 km (0.3 mi) or 
more. Killer whales also appear to be more tolerant of seismic shooting 
in deeper water (Stone, 2003; Gordon et al., 2004).

Sperm Whales

    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 alteration of foraging behavior upon exposure to 
airgun sounds (Jochens et al., 2008; Miller et al., 2009; Tyack, 2009).

Beaked Whales

    There are almost no specific data on the behavioral reactions of 
beaked whales to seismic surveys. Most beaked whales tend to avoid 
approaching vessels of other types (e.g., Wursig et al., 1998). They 
may also dive for an extended period when approached by a vessel (e.g., 
Kasuya, 1986), although it is uncertain how much longer such dives may 
be as compared to dives by undisturbed beaked whales, which also are 
often quite long (Baird et al., 2006; Tyack et al., 2006).
    Based on a single observation, Aguilar-Soto et al. (2006) suggested 
a reduction in foraging efficiency of Cuvier's beaked whales during a 
close approach by a vessel. In contrast, Moulton and Holst (2010) 
reported 15 sightings of beaked whales during seismic studies in the 
northwest Atlantic and the authors observed seven of those sightings 
during times when at least one airgun was operating. Because sighting 
rates and distances were similar during seismic and non-seismic 
periods, the authors could not correlate changes to beaked whale 
behavior to the effects of airgun operations (Moulton and Holst, 2010).
    Similarly, other studies have observed northern bottlenose whales 
remain in the general area of active seismic operations while 
continuing 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).

Pinnipeds

    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 (Phoca hispida) 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 hundred 
meters, and many seals remained within 100-200 m (328-656 ft) of the 
trackline as the operating airgun array passed by the animals. 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,

[[Page 75366]]

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).

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).
    PTS is considered an 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 non-human animals.
    Recent studies by Kujawa and Liberman (2009) and Lin et al. (2011) 
found that despite completely reversible threshold shifts that leave 
cochlear sensory cells intact, large threshold shifts could cause 
synaptic level changes and delayed cochlear nerve degeneration in mice 
and guinea pigs, respectively. NMFS notes that the high level of TTS 
that led to the synaptic changes shown in these studies is in the range 
of the high degree of TTS that Southall et al. (2007) used to calculate 
PTS levels. It is unknown whether smaller levels of TTS would lead to 
similar changes. NMFS, however, acknowledges the complexity of noise 
exposure on the nervous system, and will re-examine this issue as more 
data become available.
    For marine mammals, published data are limited to the captive 
bottlenose dolphin, beluga, harbor porpoise, and Yangtze finless 
porpoise (Finneran et al., 2000, 2002b, 2003, 2005a, 2007, 2010a, 
2010b; Finneran and Schlundt, 2010; Lucke et al., 2009; Mooney et al., 
2009a, 2009b; Popov et al., 2011a, 2011b; Kastelein et al., 2012a; 
Schlundt et al., 2000; Nachtigall et al., 2003, 2004). For pinnipeds in 
water, data are limited to measurements of TTS in harbor seals, an 
elephant seal, and California sea lions (Kastak et al., 1999, 2005; 
Kastelein et al., 2012b).
    Lucke et al. (2009) found a threshold shift (TS) of a harbor 
porpoise after exposing it to airgun noise with a received sound 
pressure level (SPL) at 200.2 dB (peak-to-peak) re: 1 [mu]Pa, which 
corresponds to a sound exposure level of 164.5 dB re: 1 [mu]Pa2 s after 
integrating exposure. NMFS currently uses the root-mean-square (rms) of 
received SPL at 180 dB and 190 dB re: 1 [mu]Pa as the threshold above 
which permanent threshold shift (PTS) could occur for cetaceans and 
pinnipeds, respectively. Because the airgun noise is a broadband 
impulse, one cannot directly determine the equivalent of rms SPL from 
the reported peak-to-peak SPLs. However, applying a conservative 
conversion factor of 16 dB for broadband signals from seismic surveys 
(McCauley, et al., 2000) to correct for the difference between peak-to-
peak levels reported in Lucke et al. (2009) and rms SPLs, the rms SPL 
for TTS would be approximately 184 dB re: 1 [mu]Pa, and the received 
levels associated with PTS (Level A harassment) would be higher. This 
is still above NMFS' current 180 dB rms re: 1 [mu]Pa threshold for 
injury. However, NMFS recognizes that TTS of harbor porpoises is lower 
than other cetacean species empirically tested (Finneran & Schlundt, 
2010; Finneran et al., 2002; Kastelein and Jennings, 2012).
    A recent study on bottlenose dolphins (Schlundt, et al., 2013) 
measured hearing thresholds at multiple frequencies to determine the 
amount of TTS induced before and after exposure to a sequence of 
impulses produced by a seismic airgun. The airgun volume and operating 
pressure varied from 40-150 in\3\ and 1000-2000 psi, respectively. 
After three years and 180 sessions, the authors observed no significant 
TTS at any test frequency, for any combinations of airgun volume, 
pressure, or proximity to the dolphin during behavioral tests 
(Schlundt, et al., 2013). Schlundt et al. (2013) suggest that the 
potential for airguns to cause hearing loss in dolphins is lower than 
previously predicted, perhaps as a result of the low-frequency content 
of airgun impulses compared to the high-frequency hearing ability of 
dolphins.
    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

[[Page 75367]]

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 one 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. Cetaceans generally avoid the immediate 
area around operating seismic vessels, as do some other marine mammals. 
Some pinnipeds show avoidance reactions to airguns, but their avoidance 
reactions are generally not as strong or consistent compared to 
cetacean reactions.

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 classic 
``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 hypothalamus-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 the body quickly replenishes after alleviation of the 
stressor. 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, it diverts energy resources 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 
called ``distress'' (sensu Seyle, 1950) or ``allostatic loading'' 
(sensu McEwen and Wingfield, 2003). This pathological state will last 
until the animal replenishes its biotic reserves sufficient to restore 
normal function. Note that these examples involved a long-term (days or 
weeks) stress response exposure to stimuli.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses have also been documented 
fairly well through controlled experiment; because this physiology 
exists in every vertebrate that has been studied, it is not surprising 
that stress responses and their costs have been documented in both 
laboratory and free-living animals (for examples see, Holberton et al., 
1996; Hood et al., 1998; Jessop et al., 2003; Krausman et al., 2004; 
Lankford et al., 2005; Reneerkens et al., 2002; Thompson and Hamer, 
2000). Although no information has been collected on the physiological 
responses of marine mammals to anthropogenic sound exposure, studies of 
other marine animals and terrestrial animals would lead us to expect 
some marine mammals to experience physiological stress responses and, 
perhaps, physiological responses that would be classified as 
``distress'' upon exposure to anthropogenic sounds.
    For example, Jansen (1998) reported on the relationship between 
acoustic exposures and physiological responses that are indicative of 
stress responses in humans (e.g., elevated respiration and increased 
heart rates). Jones (1998) reported on reductions in human performance 
when faced with acute, repetitive exposures to acoustic disturbance. 
Trimper et al. (1998) reported on the physiological stress responses of 
osprey to low-level aircraft noise while Krausman et al. (2004) 
reported on the auditory and physiology stress responses of endangered 
Sonoran pronghorn to military overflights. Smith et al. (2004a, 2004b) 
identified noise-induced physiological transient stress responses in 
hearing-specialist fish (i.e., goldfish) that accompanied short- and 
long-term hearing losses. Welch and Welch (1970) reported physiological 
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

[[Page 75368]]

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, NMFS assumes that acoustic exposures sufficient to trigger 
onset PTS or TTS would be accompanied by physiological stress 
responses. More importantly, marine mammals might experience stress 
responses at received levels lower than those necessary to trigger 
onset TTS. Based on empirical studies of the time required to recover 
from stress responses (Moberg, 2000), NMFS also assumes that stress 
responses could persist beyond the time interval required for animals 
to recover from TTS and might result in pathological and pre-
pathological states that would be as significant as behavioral 
responses to TTS.
    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, including some pinnipeds, are 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).

2. 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 
survey. 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.
    NMFS has 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 
avoidance responses that led 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

[[Page 75369]]

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 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 associated with the operation of mid-frequency 
tactical sonar, there is concern that mid-frequency sonar sounds can 
cause serious impacts to marine mammals (see earlier discussion). 
However, the echosounder proposed for use by the Langseth is quite 
different from sonar used for naval 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.
    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 [mu]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 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.

3. 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), 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

[[Page 75370]]

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 a vessel's propeller could injure an animal just below the 
surface. 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 size of the 
array generally carries a lower risk of entanglement for marine 
mammals. Wildlife, especially slow moving individuals, such as large 
whales, have a low probability of entanglement due to the low amount of 
slack in the lines, slow speed of the survey vessel, and onboard 
monitoring. Lamont-Doherty has no recorded cases of entanglement of 
marine mammals during their conduct of over 11 years of seismic surveys 
(NSF, 2015).

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 Fish as Prey Species

    NMFS considered 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

[[Page 75371]]

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 by exposure to seismic survey sounds. Peer-
reviewed scientific literature has presented few data on this subject. 
NMFS is aware of only two papers with proper experimental methods, 
controls, and careful pathological investigation that implicate sounds 
produced by actual seismic survey airguns in causing adverse anatomical 
effects. One such study indicated anatomical damage, and the second 
indicated temporary threshold shift in fish hearing. The anatomical 
case is McCauley et al. (2003), who found that exposure to airgun sound 
caused observable anatomical damage to the auditory maculae of pink 
snapper (Pagrus auratus). This damage in the ears had not been repaired 
in fish sacrificed and examined almost two months after exposure. On 
the other hand, Popper et al. (2005) documented only temporary 
threshold shift (as determined by auditory brainstem response) in two 
of three fish species from the Mackenzie River Delta. This study found 
that broad whitefish (Coregonus nasus) exposed to five airgun shots 
were not significantly different from those of controls. During both 
studies, the repetitive exposure to sound was greater than what 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 s 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 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. The authors concluded that mortality 
rates caused by exposure to seismic surveys were low, as compared to 
natural mortality rates, and suggested that the impact of seismic 
surveying on recruitment to a fish stock was not significant.
    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.

[[Page 75372]]

    The former 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). NMFS 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 NSF's 2011 Programmatic Environmental 
Impact Statement (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 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

[[Page 75373]]

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 and 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, NMFS does not anticipate 
that the proposed activity would have any habitat-related effects that 
could cause significant or long-term consequences for individual marine 
mammals or their populations.

Proposed Mitigation

    In order to issue an Incidental Harassment Authorization under 
section 101(a)(5)(D) of the MMPA, NMFS must set forth the permissible 
methods of taking pursuant to such activity, and other means of 
effecting the least practicable adverse impact on such species or stock 
and its habitat, paying particular attention to rookeries, mating 
grounds, and areas of similar significance, and on the availability of 
such species or stock for taking for certain subsistence uses (where 
relevant).
    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 Lamont-Doherty and NSF-funded 
seismic research cruises as approved by us and detailed in the NSF's 
2011 PEIS and 2015 draft environmental analysis;
    (2) Previous incidental harassment authorizations applications and 
authorizations that NMFS has 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.
    NMFS reviewed Lamont-Doherty's proposed mitigation measures and has 
proposed an additional measure to effect the least practicable adverse 
impact on marine mammals. They are:
    (1) Expanded power down procedures for concentrations of six or 
more whales that do not appear to be traveling (e.g., feeding, 
socializing, etc.).

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. 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 
exclusion zone for cetaceans or pinnipeds.
    During seismic operations, at least four protected species 
observers would be aboard the Langseth. Lamont-Doherty would appoint 
the observers with NMFS 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 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.
    Lamont-Doherty would immediately power down or shutdown the airguns 
when observers see marine mammals within or about to enter the 
designated exclusion zone. 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).

[[Page 75374]]

Proposed Mitigation 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 one would expect to receive sound levels (160-, 180-, and 190-
dB,) from the airgun array and a single airgun. 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).

    Table 3--Predicted Distances to Which Sound Levels Greater Than or Equal to 160 re: 1 [micro]Pa Could Be
                    Received During the Proposed Survey Areas Within the South Atlantic Ocean
                                          [January through March, 2016]
----------------------------------------------------------------------------------------------------------------
                                                                          Predicted RMS distances \1\ (m)
   Source and volume  (in\3\)     Tow depth  (m)    Water depth  -----------------------------------------------
                                                        (m)           190 dB          180 dB          160 dB
----------------------------------------------------------------------------------------------------------------
Single Bolt airgun..............               9         > 1,000             100             100             388
(40 in\3\)......................
36-Airgun Array.................               9         > 1,000             286             927           5,780
(6,600 in\3\)...................
----------------------------------------------------------------------------------------------------------------
\1\ Predicted distances based on information presented in Lamont-Doherty's application.

    The 180- or 190-dB level shutdown criteria are applicable to 
cetaceans and pinnipeds respectively as specified by NMFS (2000). 
Lamont-Doherty used these levels to establish the exclusion zones as 
presented in their application.
    Lamont-Doherty used a process to develop and confirm the 
conservativeness of the mitigation radii for a shallow-water seismic 
survey in the northeast Pacific Ocean offshore Washington in 2012. 
Crone et al. (2014) analyzed the received sound levels from the 2012 
survey and reported that the actual distances for the exclusion and 
buffer zones were two to three times smaller than what Lamont-Doherty's 
modeling approach predicted. While these results confirm the role that 
bathymetry plays in propagation, they also confirm that empirical 
measurements from the Gulf of Mexico survey likely over-estimated the 
size of the exclusion zones for the 2012 Washington shallow-water 
seismic surveys. NMFS reviewed this preliminary information in 
consideration of how these data reflect on the accuracy of Lamont-
Doherty's current modeling approach.

Power Down Procedures

    A power down involves decreasing the number of airguns in use such 
that the radius of the 180-dB or 190-dB exclusion zone is smaller to 
the extent that marine mammals are no longer within or about to enter 
the exclusion zone. A power down of the airgun array can also occur 
when the vessel is moving from one seismic line to another. During a 
power down for mitigation, the Langseth would operate one airgun (40 
in\3\). The continued operation of one airgun would alert marine 
mammals to the presence of the seismic vessel in the area. A shutdown 
occurs when the Langseth suspends all airgun activity.
    If the observer detects a marine mammal outside the exclusion zone 
and the animal is likely to enter the zone, the crew would power down 
the airguns to reduce the size of the 180-dB or 190-dB exclusion zone 
before the animal enters that zone. Likewise, if a mammal is already 
within the zone after detection, the crew would power-down the airguns 
immediately. During a power down of the airgun array, the crew would 
operate a single 40-in\3\ airgun which has a smaller exclusion zone. If 
the observer detects a marine mammal within or near the smaller 
exclusion zone around the airgun (Table 3), the crew would shut down 
the single airgun (see next section).

Resuming Airgun Operations After a Power Down

    Following a power-down, the Langseth crew would not resume full 
airgun activity until the marine mammal has cleared the 180-dB or 190-
dB exclusion zone. 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).
    NMFS estimates that the Langseth would transit outside the original 
180-dB or 190-dB exclusion zone after an 8-minute wait period. This 
period is based on 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

[[Page 75375]]

the single airgun when more than one airgun (typically the full airgun 
array) is operating.
    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, Lamont-Doherty 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 an observer sights a marine mammal within or near the 
applicable exclusion zones. NMFS refers the reader to Figure 2, which 
presents a flowchart representing the ramp-up, power down, and shut 
down protocols described in this notice.
BILLING CODE 3510-22-C

[[Page 75376]]

[GRAPHIC] [TIFF OMITTED] TN01DE15.057

BILLING CODE 3510-22-P

Special Procedures for Concentrations of Large Whales

    The Langseth would avoid exposing concentrations of large whales to 
sounds greater than 160 dB re: 1 [micro]Pa within the 160-dB zone and 
would power down the array, if necessary. For purposes of this proposed 
survey, a concentration or

[[Page 75377]]

group of whales would consist of six or more individuals visually 
sighted that do not appear to be traveling (e.g., feeding, socializing, 
etc.).

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 the Langseth to the transect 
line. However, if the animal(s) appear likely to enter the exclusion 
zone, the Langseth would undertake further mitigation actions, 
including a power down or shut down of the airguns.

Mitigation Conclusions

    NMFS has carefully evaluated 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 following factors in relation to 
one another:
     The manner in which, and the degree to which, the 
successful implementation of the measure is expected to minimize 
adverse impacts to marine mammals;
     The proven or likely efficacy of the specific measure to 
minimize adverse impacts as planned; and
     The practicability of the measure for applicant 
implementation.
    Any mitigation measure(s) prescribed by NMFS should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to the accomplishment of one or more of 
the general goals listed here:
    1. Avoidance or minimization of injury or death of marine mammals 
wherever possible (goals 2, 3, and 4 may contribute to this goal).
    2. A reduction in the numbers of marine mammals (total number or 
number at biologically important time or location) exposed to airgun 
operations that we expect to result in the take of marine mammals (this 
goal may contribute to 1, above, or to reducing harassment takes only).
    3. A reduction in the number of times (total number or number at 
biologically important time or location) individuals would be exposed 
to airgun operations that we expect to result in the take of marine 
mammals (this goal may contribute to 1, above, or to reducing 
harassment takes only).
    4. A reduction in the intensity of exposures (either total number 
or number at biologically important time or location) to airgun 
operations that we expect to result in the take of marine mammals (this 
goal may contribute to a, above, or to reducing the severity of 
harassment takes only).
    5. Avoidance or minimization of adverse effects to marine mammal 
habitat, paying special attention to the food base, activities that 
block or limit passage to or from biologically important areas, 
permanent destruction of habitat, or temporary destruction/disturbance 
of habitat during a biologically important time.
    6. For monitoring directly related to mitigation--an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation.
    Based on the evaluation of Lamont-Doherty's proposed measures, as 
well as other measures proposed by NMFS (i.e., special procedures for 
concentrations of large whales), NMFS has preliminarily determined that 
the proposed mitigation measures provide the means of effecting the 
least practicable impact on marine mammal species or stocks and their 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance.

Proposed Monitoring

    In order to issue an Incidental Harassment Authorization 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. NMFS, NSF, 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 NMFS should accomplish one or 
more of the following general goals:
    1. An increase in the probability of detecting marine mammals, both 
within the mitigation zone (thus allowing for more effective 
implementation of the mitigation) and during other times and locations, 
in order to generate more data to contribute to the analyses mentioned 
later;
    2. An increase in our understanding of how many marine mammals 
would be affected by seismic airguns and other active acoustic sources 
and the likelihood of associating those exposures with specific adverse 
effects, such as behavioral harassment, temporary or permanent 
threshold shift;
    3. An increase in our understanding of how marine mammals respond 
to stimuli that we expect to result in take and how those anticipated 
adverse effects on individuals (in different ways and to varying 
degrees) may impact the population, species, or stock (specifically 
through effects on annual rates of recruitment or survival) through any 
of the following methods:
    a. Behavioral observations in the presence of stimuli compared to 
observations in the absence of stimuli (i.e., 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., 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 NMFS 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 Lamont-Doherty.

[[Page 75378]]

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 acoustically detect cetaceans.
    The passive acoustic monitoring system consists of hardware (i.e., 
hydrophones) and software. The ``wet end'' of the system consists of a 
towed hydrophone array connected to the vessel by a tow cable. The tow 
cable is 250 m (820.2 ft) long and the hydrophones are fitted in the 
last 10 m (32.8 ft) of cable. A depth gauge, attached to the free end 
of the cable, 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 other visual observers who would 
rotate monitoring duties. 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 help better understand the impacts of the activity on marine mammals 
and 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 NSF within 90 
days after the end of the cruise. The report would describe the 
operations conducted and sightings of marine mammals 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 occurred above

[[Page 75379]]

the harassment threshold based on the observations.
    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), 
Lamont-Doherty shall immediately cease the specified activities and 
immediately report the take to the Chief Permits and Conservation 
Division, Office of Protected Resources, NMFS. 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.
    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 Chief Permits and Conservation Division, Office of 
Protected Resources, NMFS. The report must include the same information 
identified in the paragraph above this section. Activities may continue 
while NMFS reviews the circumstances of the incident. NMFS would work 
with 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 Chief Permits and Conservation Division, Office of 
Protected Resources, NMFS, 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.

Estimated Take by Incidental Harassment

    Except with respect to certain activities not pertinent here, 
section 3(18) 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 array may have the potential to 
result in the behavioral disturbance of some marine mammals and may 
have an even smaller potential to result in permanent threshold shift 
(non-lethal injury) of some marine mammals. NMFS expects that the 
proposed mitigation and monitoring measures would minimize the 
possibility of injurious or lethal takes. However, NMFS cannot discount 
the possibility (albeit small) that exposure to energy from the 
proposed survey could result in non-lethal injury (Level A harassment). 
Thus, NMFS proposes to authorize take by Level B harassment and Level A 
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 subject to the limitations in take described 
in Table 5 later in this notice.

            Table 4--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).
------------------------------------------------------------------------

    NMFS' practice is to apply the 160 dB re: 1 [micro]Pa received 
level threshold for underwater impulse sound levels to predict whether 
behavioral disturbance that rises to the level of Level B harassment is 
likely to occur. NMFS' practice is to apply the 180 dB or 190 dB re: 1 
[micro]Pa received level threshold for underwater impulse sound levels 
to predict whether permanent threshold shift (auditory injury), which 
we consider as Level A harassment is likely to occur.

Acknowledging Uncertainties in Estimating Take

    Given the many uncertainties in predicting the quantity and types 
of impacts of sound on marine mammals, it is common practice to 
estimate how many animals are likely to be present within a particular 
distance of a given activity, or exposed to a particular level of sound 
and use that information to predict how many animals are taken. In 
practice, depending on the amount of information available to 
characterize daily and seasonal movement and distribution of affected 
marine mammals, distinguishing between the numbers of individuals 
harassed and the instances of harassment can be difficult to parse. 
Moreover, when one considers the duration of the activity, in the 
absence of information to predict the degree to which individual 
animals are likely exposed repeatedly on subsequent days, the simple 
assumption is that entirely new animals are exposed in every day, which 
results in a take estimate that in some circumstances overestimates the 
number of individuals harassed.
    The following sections describe NMFS' methods to estimate take by 
incidental harassment. We base these estimates on the number of marine

[[Page 75380]]

mammals that potentially harassed by seismic operations with the airgun 
array during approximately 3,236 km (2,028 mi) of transect lines in the 
South Atlantic Ocean.
    Modeled Number of Instances of Exposures: Lamont-Doherty would 
conduct the proposed seismic survey within the high seas in the South 
Atlantic Ocean. NMFS presents estimates of the anticipated numbers of 
instances that marine mammals could be exposed to sound levels greater 
than or equal to 160, 180, and 190 dB re: 1 [mu]Pa during the proposed 
seismic survey. Table 5 represents the numbers of instances of take 
that NMFS proposes to authorize for this survey within the South 
Atlantic Ocean.
    NMFS' Take Estimate Method for Species with Density Information: In 
order to estimate the potential number of instances that marine mammals 
could be exposed to airgun sounds above the 160-dB Level B harassment 
threshold and the 180-dB Level A harassment thresholds, NMFS used the 
following approach for species with density estimates derived from the 
Navy's Atlantic Fleet Training and Testing Navy Marine Species Density 
Database maps for the survey area in the Southern Atlantic Ocean. NMFS 
used the highest density range for each species within the survey area.
    (1) Calculate the total area that the Langseth would ensonify above 
the 160-dB Level B harassment threshold and above the 180-dB Level A 
harassment threshold for cetaceans within a 24-hour period. This 
calculation includes a daily ensonified area of approximately 1,377 
square kilometers (km\2\) (532 square miles [mi\2\]) for the five OBS 
tracklines and 1,839 km\2\ (710 mi\2\) for the MCS trackline based on 
the Langseth traveling approximately 150 km [93 mi] in one day). 
Generally, the Langseth travels approximately 137 km (85 mi) in one day 
while conducting a seismic survey, thus, NMFS' estimate of a daily 
ensonified area based on 150 km is an estimation of the theoretical 
maximum that the Langseth could travel within 24 hours.
    (2) Multiply each daily ensonified area above the 160-dB Level B 
harassment threshold by the species' density (animals/km\2\) to derive 
the predicted number of instances of exposures to received levels 
greater than or equal to 160-dB re: 1 [mu]Pa on a given day;
    (3) Multiply each product (i.e., the expected number of instances 
of exposures within a day) by the number of survey days that includes a 
25 percent contingency (i.e., a total of six days for the five OBS 
tracklines and a total of 22 days for the MCS trackline) to derive the 
predicted number of instances of exposures over the duration of the 
survey;
    (4) Multiply the daily ensonified area by each species-specific 
density to derive the predicted number of instances of exposures to 
received levels greater than or equal to 180-dB re: 1 [mu]Pa for 
cetaceans on a given day (i.e., Level A takes). This calculation 
includes a daily ensonified area of approximately 207 km\2\ (80 mi\2\) 
for the five OBS tracklines and 281 km\2\ (108 mi\2\) for the MCS 
trackline.
    (5) Multiply each product by the number of survey days that 
includes a 25 percent contingency (i.e., a total of six days for the 
five OBS tracklines and a total of 22 days for the MCS trackline). 
Subtract that product from the predicted number of instances of 
exposures to received levels greater than or equal to 160-dB re: 1 
[mu]Pa on a given day to derive the number of instances of exposures 
estimated to occur between 160 and 180-dB threshold (i.e., Level B 
takes).
    In many cases, this estimate of instances of exposures is likely an 
overestimate of the number of individuals that are taken, because it 
assumes 100 percent turnover in the area every day, (i.e., that each 
new day results in takes of entirely new individuals with no repeat 
takes of the same individuals over the 22-day period (28 days with 
contingency). It is difficult to quantify to what degree this method 
overestimates the number of individuals potentially taken. Except as 
described later for a few specific species, NMFS uses this number of 
instances as the estimate of individuals (and authorized take) even 
though NMFS is aware that the number may be somewhat high due to the 
use of the maximum density estimate from the NMSDD.
    Take Estimates for Species with Less than One Instance of Exposure: 
Using the approach described earlier, the model generated instances of 
take for some species that were less than one over the 28-day duration. 
Those species include the humpback, blue, Bryde's, pygmy sperm, and 
dwarf sperm whale. NMFS used data based on dedicated survey sighting 
information from the Atlantic Marine Assessment Program for Protected 
Species (AMAPPS) surveys in 2010, 2011, and 2013 (AMAPPS, 2010, 2011, 
2013) to estimate take and assumed that Lamont-Doherty could 
potentially encounter one group of each species during the proposed 
seismic survey. NMFS believes it is reasonable to use the average 
(mean) group size (weighted by effort and rounded up) from the AMMAPS 
surveys for humpback whale (3), blue whale (2), Bryde's whale (2), 
pygmy sperm whale (2), and dwarf sperm whale (2) to derive a reasonable 
estimate of take for eruptive occurrences.
    Take Estimates for Species with No Density Information: Density 
information for the Southern right whale, southern elephant seal, and 
Subantarctic fur seal in the South Atlantic Ocean is data poor or non-
existent. When density estimates were not available, NMFS used data 
based on dedicated survey sighting information from the Atlantic Marine 
Assessment Program for Protected Species (AMAPPS) surveys in 2010, 
2011, and 2013 (AMAPPS, 2010, 2011, 2013) to estimate take for the 
three species. NMFS assumed that Lamont-Doherty could potentially 
encounter one group of each species during the seismic survey. NMFS 
believes it is reasonable to use the average (mean) group size 
(weighted by effort and rounded up) for North Atlantic right whales (3) 
from the AMMAPS surveys for the Southern right whale and the mean group 
size for unidentified seals (2) from the AMMAPS surveys for southern 
elephant and Subantarctic fur seals multiplied by 28 days to derive an 
estimate of take from a potential encounter.
    NMFS used sighting information from a survey off Namibia, Africa 
(Rose and Payne, 1991) to estimate a mean group size for southern right 
whale dolphins (58) and also multiplied that estimate by 28 days to 
derive an estimate of take from a potential encounter with that 
species.

[[Page 75381]]



  Table 5--Densities and/or Mean Group Size, and Estimates of the Possible Numbers of Marine Mammals and Population Percentages Exposed to Sound Levels
                Greater Than or Equal to 160 dB re: 1 [mu]Pa Over 28 Days During the Proposed Seismic Survey in the South Atlantic Ocean
                                                              [January through March, 2016]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Modeled number
                                                             of instances of
                                                Density       exposures to    Proposed Level  Proposed Level    Percent of
                  Species                    estimate \1\    sound levels >=    A take \3\      B take \3\    population \4\     Population trend \5\
                                                              160, 180, and
                                                               190 dB \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Antarctic minke whale.....................        0.054983      2,276,396, -             396           2,276           0.519  Unknown.
Blue whale................................        0.000032           4, 0, -               0               4           2.074  Unknown.
Bryde's whale.............................        0.000262          56, 0, -               0              56           0.128  Unknown.
Common minke whale........................        0.054983      2,276,396, -             396           2,276           0.519  Unknown.
Fin whale.................................        0.002888        106, 28, -              28             106           0.609  Unknown.
Humpback whale............................        0.000078           6, 0, -               0               6           0.200  [uarr]
Sei whale.................................        0.002688        106, 28, -              28             106           1.340  Unknown.
Southern right whale......................              NA          84, 0, -               0              84           0.700  Unknown.
Sperm whale...............................        0.001214          50, 0, -               0              50           0.014  Unknown.
Dwarf sperm whale.........................        0.000041           4, 0, -               0               4           1.480  Unknown.
Pygmy sperm whale.........................        0.000021           4, 0, -               0               4           1.480  Unknown.
Cuvier's beaked whale.....................        0.003831        156, 28, -              28             156           0.031  Unknown.
Andrew's beaked whale.....................        0.000511          28, 0, -               0              28           0.005  Unknown.
Arnoux's beaked whale.....................        0.000956          28, 0, -               0              28           0.005  Unknown.
Blainville's beaked whale.................        0.000663          28, 0, -               0              28           0.005  Unknown.
Gervais' beaked whale.....................        0.001334          56, 0, -               0              56           0.009  Unknown.
Gray's beaked whale.......................        0.000944          28, 0, -               0              28           0.005  Unknown.
Hector's beaked whale.....................        0.000246           0, 0, -               0               0           0.000  Unknown.
Shepherd's beaked whale...................        0.000816          28, 0, -               0              28           0.005  Unknown.
Strap-toothed beaked whale................        0.000638          28, 0, -               0              28           0.005  Unknown.
True's beaked whale.......................        0.000876          28, 0, -               0              28           0.005  Unknown.
Southern bottlenose whale.................        0.000917          28, 0, -               0              28           0.005  Unknown.
Bottlenose dolphin........................        0.020744       848, 156, -             156             848           0.167  Unknown.
Rough-toothed dolphin.....................        0.000418          22, 0, -               0              22           8.118  Unknown.
Pantropical spotted dolphin...............        0.003674        156, 28, -              28             156           5.521  Unknown.
Striped dolphin...........................        0.174771   7,208, 1,294, -           1,294           7,208          15.513  Unknown.
Fraser's dolphin..........................        0.001568          56, 0, -               0              56           0.019  Unknown.
Spinner dolphin...........................        0.006255        262, 50, -              50             262           0.026  Unknown.
Atlantic spotted dolphin..................        0.023756       982, 184, -             184             982           2.608  Unknown.
Clymene dolphin...........................        0.000258           0, 0, -               0               0           0.000  Unknown.
Risso's dolphin...........................        0.037399     1,540, 290, -             290           1,540           8.844  Unknown.
Long-beaked common dolphin................        0.000105           0, 0, -               0               0           0.000  Unknown.
Short-beaked common dolphin...............        0.129873     5,356, 954, -             954           5,356           3.637  Unknown.
Southern right whale dolphin..............              NA       1,624, 0, -               0           1,624         Unknown  Unknown.
Melon-headed whale........................        0.006285        262, 50, -              50             262           0.624  Unknown.
Pygmy killer whale........................        0.001039          50, 0, -               0              50           1.395  Unknown.
False killer whale........................        0.000158           0, 0, -               0               0           0.000  Unknown.
Killer whale..............................        0.003312        134, 28, -              28             134           0.324  Unknown.
Long-finned pilot whale...................        0.007614        318, 56, -              56             318           0.187  Unknown.
Short-finned pilot whale..................        0.015616       636, 106, -             106             636           0.371  Unknown.
Southern Elephant Seal....................              NA           4, 0, 0               0               4           0.001  Unknown.
Subantarctic fur seal.....................              NA           4, 0, 0               0               4           0.001  Unknown.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Densities (where available) are expressed as number of individuals per km\2\. Densities estimated from the Navy's Atlantic Fleet Training and
  Testing Navy Marine Species Density Database maps for the survey area in the Southern Atlantic Ocean. NA = Not available.
\2\ See preceding text for information on NMFS' take estimate calculations. NA = Not applicable.
\3\ Modeled instances of exposures include adjustments for species with no density information. The Level A estimates are overestimates of predicted
  impacts to marine mammals as the estimates do not take into consideration the required mitigation measures for shutdowns or power downs if a marine
  mammal is likely to enter the 180 dB exclusion zone while the airguns are active.
\4\ Table 2 in this notice lists the stock species abundance estimates used in calculating the percentage of the population.
\5\ Population trend information from Waring et al., 2015. [uarr]= Increasing. [darr] = Decreasing. Unknown = Insufficient data.

    Lamont-Doherty did not estimate any additional take from sound 
sources other than airguns. NMFS does not expect the sound levels 
produced by the echosounder and sub-bottom profiler to exceed the sound 
levels produced by the airguns. Lamont-Doherty will not operate the 
multibeam echosounder and sub-bottom profiler during transits to and 
from the survey area, (i.e., when the airguns are not operating) and in 
between transits to each of the five OBS tracklines, and, therefore, 
NMFS does not anticipate additional takes from these sources in this 
particular case.
    NMFS considers the probability for entanglement of marine mammals 
as low because of the vessel speed and the monitoring efforts onboard 
the survey vessel. Therefore, NMFS does not believe it is necessary to 
authorize additional takes for entanglement at this time.
    The Langseth will operate at a relatively slow speed (typically 4.6 
knots [8.5 km/h; 5.3 mph]) when conducting the survey. Protected 
species observers would monitor for marine mammals, which would trigger 
mitigation measures, including vessel

[[Page 75382]]

avoidance where safe. Therefore, NMFS does not anticipate nor do we 
authorize takes of marine mammals from vessel strike.
    There is no evidence that the planned survey activities could 
result in serious injury or mortality within the specified geographic 
area for the requested proposed Authorization. The required mitigation 
and monitoring measures would minimize any potential risk for serious 
injury or mortality.

Preliminary Analysis and Determinations

Negligible Impact

    Negligible impact is ``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 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, the number of estimated 
mortalities, effects on habitat, and the status of the species.
    In making a negligible impact determination, NMFS considers:
     The number of anticipated injuries, serious injuries, or 
mortalities;
     The number, nature, and intensity, and duration of 
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 takes.
    To avoid repetition, our analysis applies to all the species listed 
in Table 5, given that NMFS expects the anticipated effects of the 
seismic airguns to be similar in nature. Where there are meaningful 
differences between species or stocks, or groups of species, in 
anticipated individual responses to activities, impact of expected take 
on the population due to differences in population status, or impacts 
on habitat, NMFS has identified species-specific factors to inform the 
analysis.
    Given the required mitigation and related monitoring, NMFS does not 
anticipate that serious injury or mortality would occur as a result of 
Lamont-Doherty's proposed seismic survey in the South Atlantic Ocean. 
Thus the proposed authorization does not authorize any mortality.
    NMFS' predicted estimates for Level A harassment take for some 
species are likely overestimates of the injury that will occur. NMFS 
expects that successful implementation of the required visual and 
acoustic mitigation measures would avoid Level A take in some 
instances. Also, NMFS expects that some individuals would avoid the 
source at levels expected to result in injury. Nonetheless, although 
NMFS expects that Level A harassment is unlikely to occur at the 
numbers proposed to be authorized, because it is difficult to quantify 
the degree to which the mitigation and avoidance will reduce the number 
of animals that might incur PTS, we are proposing to authorize (and 
analyze) the modeled number of Level A takes, which does not take the 
mitigation or avoidance into consideration. However, because of the 
constant movement of the Langseth and the animals, as well as the fact 
that the boat is not staying in any one area in which individuals would 
be expected to concentrate for any long amount of time (i.e., since the 
duration of exposure to loud sounds will be relatively short), we 
anticipate that any PTS incurred, would be in the form of only a small 
degree of permanent threshold shift and not total deafness.
    Of the marine mammal species under our jurisdiction that are known 
to occur or likely to occur in the study area, the following species 
are listed as endangered under the ESA: blue, fin, humpback, sei, 
Southern right whale, and sperm whales. The western north Atlantic 
population of humpback whales is known to be increasing. The other 
marine mammal species that may be taken by harassment during Lamont-
Doherty's seismic survey program are not listed as threatened or 
endangered under the ESA.
    Cetaceans. Odontocete reactions to seismic energy pulses are 
usually thought to be limited to shorter distances from the airgun(s) 
than are those of mysticetes, in part because odontocete low-frequency 
hearing is assumed to be less sensitive than that of mysticetes. Given 
sufficient notice through relatively slow ship speed, NMFS generally 
expects marine mammals to move away from a noise source that is 
annoying prior to becoming potentially injurious, although Level A 
takes for a small group of species are proposed for authorization here.
    Potential impacts to marine mammal habitat were discussed 
previously in this document (see the ``Anticipated Effects on Habitat'' 
section). Although some disturbance is possible to food sources of 
marine mammals, the impacts are anticipated to be minor enough as to 
not affect annual rates of recruitment or survival of marine mammals in 
the area. Based on the size of the South Atlantic Ocean where feeding 
by marine mammals occurs versus the localized area of the marine survey 
activities, any missed feeding opportunities in the direct project area 
will be minor based on the fact that other feeding areas exist 
elsewhere. Taking into account the planned mitigation measures, effects 
on cetaceans are generally expected to be restricted to avoidance of a 
limited area around the survey operation and short-term changes in 
behavior, falling within the MMPA definition of ``Level B harassment.'' 
Animals are not expected to permanently abandon any area that is 
surveyed, and any behaviors that are interrupted during the activity 
are expected to resume once the activity ceases. Only a small portion 
of marine mammal habitat will be affected at any time, and other areas 
within the South Atlantic Ocean would be available for necessary 
biological functions.
    Pinnipeds. During foraging trips, extralimital pinnipeds may not 
react at all to the sound from the proposed survey or may alert, ignore 
the stimulus, change their behavior, or avoid the immediate area by 
swimming away or diving. Behavioral responses can range from a mild 
orienting response, or a shifting of attention, to flight and panic. 
Research and observations show that pinnipeds in the water are tolerant 
of anthropogenic noise and activity. They may react in a number of ways 
depending on their experience with the sound source and what activity 
they are engaged in at the time of the exposure. Significant behavioral 
effects are more likely at higher received levels within a few 
kilometers of the source and activities involving sound from the 
proposed survey would not occur near

[[Page 75383]]

any haulout areas where resting behaviors occur.
    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 NMFS 
anticipates that the seismic operations would occur on consecutive 
days, the estimated duration of the survey would last no more than 28 
days but would increase sound levels in the marine environment in a 
relatively small area surrounding the vessel (compared to the range of 
most of the marine mammals within the proposed survey area), which is 
constantly travelling over distances, and some animals may only be 
exposed to and harassed by sound for less than a day.
    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, serious injury, or death, or 
other effects that would be expected to adversely affect reproduction 
or survival of any individuals. They include:
     The anticipated impacts of Lamont-Doherty's survey 
activities on marine mammals are temporary behavioral changes due, 
primarily, to avoidance of the area;
     The likelihood that, given the constant movement of boat 
and animals and the nature of the survey design (not concentrated in 
areas of high marine mammal concentration), PTS incurred would be of a 
low level;
     The availability of alternate areas of similar habitat 
value for marine mammals to temporarily vacate the survey area during 
the operation of the airgun(s) to avoid acoustic harassment;
     The 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 therefore 
consider the potential impacts to marine mammal habitat minimal; and
     The knowledge that the survey is taking place in the open 
ocean and not located within an area of biological importance for 
breeding, calving, or foraging for marine mammals.
    Table 5 in this document outlines the number of requested Level A 
and Level B harassment takes that we anticipate as a result of these 
activities.
    Required mitigation measures, such as special shutdowns for large 
whales, vessel speed, course alteration, and visual monitoring would be 
implemented to help reduce impacts to marine mammals. Based on the 
analysis herein 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 
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, NMFS estimates that Lamont-Doherty's 
activities could potentially affect, by Level B harassment, 38 species 
of marine mammals under our jurisdiction. NMFS estimates that Lamont-
Doherty's activities could potentially affect, by Level A harassment, 
up to 16 species of marine mammals under our jurisdiction.
    For each species, the numbers of take being proposed for 
authorization are small numbers relative to the population sizes: less 
than 16 percent for striped dolphins, less than 8 percent of Risso's 
dolphins, less than 6 percent for pantropical spotted dolphins, and 
less than 4 percent for all other species. NMFS has provided the 
regional population and take estimates for the marine mammal species 
that may be taken by Level A and Level B harassment in Table 5 in this 
notice. NMFS finds that the proposed incidental take described in Table 
5 for the proposed activity would be limited to small numbers relative 
to 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 listed as endangered under the 
Endangered Species Act that may occur in the proposed survey area. 
Under section 7 of the ESA, NSF 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 NSF will conclude the consultation prior to a 
determination on the proposed issuance of the Authorization.

National Environmental Policy Act (NEPA)

    NSF has prepared a draft environmental analysis titled, Draft 
Environmental Analysis of a Marine Geophysical Survey by the R/V Marcus 
G. Langseth in the South Atlantic Ocean, Austral Summer 2016. NMFS has 
posted this document on our Web site concurrently with the publication 
of this notice. NMFS has independently evaluated the draft 
environmental analysis and has prepared a separate draft Environmental 
Assessment (DEA) titled, Proposed Issuance of an Incidental Harassment 
Authorization to Lamont-Doherty Earth Observatory to Take Marine 
Mammals by Harassment Incidental to a Marine Geophysical Survey in the 
South Atlantic Ocean, January-March 2016. Information in Lamont-
Doherty's application, NSF's Draft environmental analysis, NMFS' DEA 
and this notice collectively provide the environmental information 
related to proposed issuance of an Authorization for public review and 
comment. NMFS will review all comments submitted in response to this 
notice as we complete the NEPA process, including a decision of whether 
to sign a Finding of No Significant Impact (FONSI), prior to a final 
decision on the proposed 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 South Atlantic Ocean, early January through March 31, 
2016 provided they incorporate the proposed mitigation, monitoring, and 
reporting requirements.

Draft Proposed Authorization

    This section contains the draft text for the proposed 
Authorization. NMFS proposes to include this language in the 
Authorization if issued.

Incidental Harassment Authorization

    We hereby authorize the Lamont-Doherty Earth Observatory (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 South Atlantic Ocean 
January through March 2016.

[[Page 75384]]

1. Effective Dates

    This Authorization is valid from early January through March 31, 
2016.

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 South Atlantic Ocean, located approximately between 10-35 
[deg]W, 27-33 [deg]S as specified in Lamont-Doherty's application and 
the National Science Foundation's environmental analysis.

3. Species Authorized and Level of Takes

    a. This authorization limits the incidental taking of marine 
mammals, by harassment only, to the following species in the area 
described in Table 5 in this notice.
    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. The taking by 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 is prohibited and may result in the modification, 
suspension, or revocation of this Authorization.
    c. This Authorization limits the methods authorized for taking by 
harassment to the following acoustic sources:
    i. a sub-airgun array with a total capacity of 6,600 in\3\ (or 
smaller);

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 the Chief, 
Permits and Conservation Division.

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 nautical twilight-dawn to 
nautical 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 (7 x 50 Fujinon), and big-eye binoculars (25 x 150).

Exclusion Zones

    b. Establish a 180-decibel (dB) or 190-dB exclusion zone for 
cetaceans and pinnipeds, respectively, before starting the airgun 
subarray (6,660 in\3\); and a 180-dB or 190-dB exclusion zone for 
cetaceans and pinnipeds, respectively for the single airgun (40 in\3\). 
Observers will use the predicted radius distance for the 180-dB or 190-
dB exclusion zones for cetaceans and pinnipeds.

Visual Monitoring at the Start of Airgun Operations

    c. Monitor the entire extent of the exclusion 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 for cetaceans or 190-dB exclusion zone 
for pinnipeds until the marine mammal(s) has left the area.
    i. If the visual observer sees a marine mammal that surfaces, then 
dives below the surface, the observer shall wait 30 minutes. If the 
observer sees no marine mammals during that time, he/she should assume 
that the animal has moved beyond the 180-dB exclusion zone for 
cetaceans or 190-dB exclusion zone for pinnipeds.
    ii. If for any reason the visual observer cannot see the full 180-
dB exclusion zone for cetaceans or the 190-dB exclusion zone for 
pinnipeds for the entire 30 minutes (i.e., rough seas, fog, darkness), 
or if marine mammals are near, approaching, or within zone, the 
Langseth may not resume airgun operations.
    iii. If one airgun is already running at a source level of at least 
180 dB re: 1 [mu]Pa or 190 dB re: 1 [mu]Pa, the Langseth may start the 
second gun-and subsequent airguns-without observing relevant exclusion 
zones for 30 minutes, provided that the observers have not seen any 
marine mammals near the relevant exclusion zones (in accordance with 
Condition 6(b)).

Passive Acoustic Monitoring

    e. Utilize the passive acoustic monitoring (PAM) system, to the 
maximum extent practicable, to detect and allow some localization of 
marine mammals around the Langseth during all airgun operations and 
during most periods when airguns are not operating. One visual observer 
and/or bioacoustician will monitor the PAM at all times in shifts no 
longer than 6 hours. A bioacoustician shall design and set up the PAM 
system and be present to operate or oversee PAM, and available when 
technical issues occur during the survey.
    f. Do and record the following when an observer detects an animal 
by the PAM:
    i. notify the visual observer immediately of a vocalizing marine 
mammal so a power-down or shut-down can be initiated, if required;
    ii. enter the information regarding the vocalization into a 
database. The data to be entered include an acoustic encounter 
identification number, whether it was linked with a visual sighting, 
date, time when first and last heard and whenever any additional 
information was recorded, position, water depth when first detected, 
bearing if determinable, species or species group (e.g., unidentified 
dolphin, sperm whale, monk seal), types and nature of sounds heard 
(e.g., clicks, continuous, sporadic, whistles, creaks, burst pulses,

[[Page 75385]]

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 any time 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.

Resuming Airgun Operations After a Shutdown

    n. Following a shutdown, if the observer has visually confirmed 
that the animal has departed the 180-dB zone for cetaceans or the 190-
dB zone for pinnipeds within a period of less than or equal to 8 
minutes after the shutdown, then the Langseth may resume airgun 
operations at full power.
    o. If the observer has not seen the animal depart the 180-dB zone 
for cetaceans or the 190-dB zone for pinnipeds, the Langseth shall not 
resume airgun activity until 15 minutes has passed for species with 
shorter dive times (i.e., small odontocetes and pinnipeds) or 30 
minutes has passed for species with longer dive durations (i.e., 
mysticetes and large odontocetes, including sperm, pygmy sperm, dwarf 
sperm, killer, and beaked whales). The Langseth will follow the ramp-up 
procedures described in Conditions 6(g).

Survey Operations at Night

    p. 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.
    q. 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.

Mitigation Airgun

    s. 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.

Special Procedures for Concentrations of Large Whales

    t. The Langseth will power-down the array and avoid concentrations 
of large whales if possible (i.e., avoid exposing concentrations of 
these animals to sounds greater than 160 dB re: 1 [mu]Pa). For purposes 
of the survey, a concentration or group of whales will consist of six 
or more individuals visually sighted that do not appear to be traveling 
(e.g., feeding, socializing, etc.). The Langseth will follow the 
procedures described in Conditions 6(k) for resuming operations after a 
power down.

7. Reporting Requirements

    This Authorization requires the Holder of this Authorization to:
    a. Submit a draft report on all activities and monitoring results 
to the Office of Protected Resources, National Marine Fisheries 
Service, within 90 days of the completion of the Langseth's cruise. 
This report must contain and summarize the following information:
    i. Dates, times, locations, heading, speed, weather, sea conditions 
(including Beaufort sea state and wind force), and associated 
activities during all seismic operations and marine mammal sightings.
    ii. Species, number, location, distance from the vessel, and 
behavior of any marine mammals, as well as associated seismic activity 
(number of shutdowns), observed throughout all monitoring activities.
    iii. An estimate of the number (by species) of marine mammals with 
known exposures to the seismic activity (based on visual observation) 
at received

[[Page 75386]]

levels greater than or equal to 160 dB re: 1 [mu]Pa and/or 180 dB re 1 
[mu]Pa for cetaceans and 190-dB re 1 [mu]Pa for pinnipeds and a 
discussion of any specific behaviors those individuals exhibited.
    iv. An estimate of the number (by species) of marine mammals with 
estimated exposures (based on modeling results) to the seismic activity 
at received levels greater than or equal to 160 dB re: 1 [mu]Pa and/or 
180 dB re 1 [mu]Pa for cetaceans and 190-dB re 1 [mu]Pa for pinnipeds 
with a discussion of the nature of the probable consequences of that 
exposure on the individuals.
    v. A description of the implementation and effectiveness of the: 
(A) terms and conditions of the Biological Opinion's Incidental Take 
Statement (attached); and (B) mitigation measures of the Incidental 
Harassment Authorization. For the Biological Opinion, the report will 
confirm the implementation of each Term and Condition, as well as any 
conservation recommendations, and describe their effectiveness, for 
minimizing the adverse effects of the action on Endangered Species Act 
listed marine mammals.
    b. Submit a final report to the Chief, Permits and Conservation 
Division, Office of Protected Resources, National Marine Fisheries 
Service, within 30 days after receiving comments from us on the draft 
report. If we decide that the draft report needs no comments, we will 
consider the draft report to be the final report.

8. Reporting Prohibited Take

    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner not permitted by the 
authorization (if issued), such as an injury, serious injury, or 
mortality (e.g., ship-strike, gear interaction, and/or entanglement), 
Lamont-Doherty shall immediately cease the specified activities and 
immediately report the take to the Chief, Permits and Conservation 
Division, Office of Protected Resources, NMFS, at 301-427-8401 and/or 
by email. 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 Chief, Permits and Conservation Division, Office of 
Protected Resources, NMFS, at 301-427-8401 and/or by email. The report 
must include the same information identified in the paragraph above 
this section. Activities may continue while NMFS reviews the 
circumstances of the incident. NMFS would work with 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 Chief, Permits and Conservation Division, Office of 
Protected Resources, NMFS, at 301-427-8401 and/or by email, 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

    Lamont-Doherty is required to comply with the Terms and Conditions 
of the Incidental Take Statement corresponding to the Endangered 
Species Act Biological Opinion issued to the National Science 
Foundation and NMFS' Office of Protected Resources, Permits and 
Conservation Division (attached). A copy of this Authorization and the 
Incidental Take Statement must be in the possession of all contractors 
and protected species observers operating under the authority of this 
Incidental Harassment Authorization.

Request for Public Comments

    NMFS invites comments on our analysis, the draft authorization, and 
any other aspect of the Notice of 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 application.

    Dated: November 24, 2015.
Perry F. Gayaldo,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2015-30333 Filed 11-25-15; 8:45 am]
 BILLING CODE 3510-22-P