Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the Southeast Pacific Ocean, 2016-2017, 23117-23154 [2016-09008]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 81, Number 75 (Tuesday, April 19, 2016)]
[Notices]
[Pages 23117-23154]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-09008]



[[Page 23117]]

Vol. 81

Tuesday,

No. 75

April 19, 2016

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 Southeast Pacific Ocean, 2016-2017; Notice

Federal Register / Vol. 81 , No. 75 / Tuesday, April 19, 2016 / 
Notices

[[Page 23118]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XE451


Takes of Marine Mammals Incidental to Specified Activities; 
Marine Geophysical Survey in the Southeast Pacific Ocean, 2016-2017

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Department of 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 three marine geophysical (seismic) surveys in the 
southeast Pacific Ocean, in the latter half of 2016 and/or the 
beginning half of 2017. The proposed dates are between June 2016 and 
June 2017, to account for logistical and scheduling needs of the 
applicant. Per the Marine Mammal Protection Act (MMPA), we are 
requesting comments on our proposal to issue an Authorization to 
Lamont-Doherty to incidentally take, by level B harassment, 44 species 
of marine mammal during the specified activity and to incidentally 
take, by Level A harassment, 26 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 any serious 
injury, mortality, or deafness to occur in marine mammals as a result 
of this proposed survey.

DATES: NMFS must receive comments and information on or before May 19, 
2016.

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.Carduner@noaa.gov. Please include 0648-XE451 in the 
subject line. Comments sent via email, 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 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 also 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 
(EA), and a list of the references used in this document, write to the 
previously mentioned address, telephone the contact listed below (see 
FOR FURTHER INFORMATION CONTACT), or visit the internet at: https://www.nmfs.noaa.gov/pr/permits/incidental/research.htm.

FOR FURTHER INFORMATION CONTACT: Jordan Carduner, 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 January 19, 2016, NMFS received an application from Lamont-
Doherty requesting that NMFS issue an Authorization for the take of 
marine mammals, incidental to Oregon State University (OSU) and 
University of Texas (UT) conducting seismic surveys in the southeast 
Pacific Ocean, in the latter half of 2016 and/or the first half of 
2017. NMFS considered the application and supporting materials adequate 
and complete on March 21, 2016.
    Lamont-Doherty proposes to conduct three two-dimensional (2-D) 
surveys on the R/V Marcus G. Langseth (Langseth), a vessel owned by NSF 
and operated on its behalf by Columbia University's Lamont-Doherty 
Earth Observatory primarily in international waters of the southeast 
Pacific Ocean, with a small portion of the surveys occurring within the 
territorial waters of Chile. All proposed surveys will be conducted 
within the exclusive economic zone (EEZ) of Chile.
    Increased underwater sound generated during the operation of the 
seismic airgun array is the only aspect of the proposed activity that 
is likely to result in the take of marine mammals. We anticipate that 
take, by Level B harassment, of 44 species of marine mammals could 
result from the specified activity. Although unlikely, NMFS also 
anticipates that a small amount of take by Level A harassment of 26 
species of marine mammals could occur during the proposed survey.

Description of the Specified Activity

Overview

    Lamont-Doherty plans to use one source vessel, the Langseth, with 
an

[[Page 23119]]

array of 36 airguns as the energy source with a total volume of 
approximately 6,600 cubic inches (in \3\). The receiving system would 
consist of 64 ocean bottom seismometers (OBSs) and a single hydrophone 
streamer between 8 and 15 kilometers (km) (4.9 and 9.3 miles [mi]) in 
length. In addition to the operations of the airgun array, a multibeam 
echosounder (MBES) and a sub-bottom profiler (SBP) would also be 
operated continuously throughout the proposed surveys. A total of 
approximately 9,633 km (5,986 mi) of transect lines would be surveyed 
in the southeast Pacific Ocean.
    The primary purpose of the northern survey is to image the 
structure of the upper and lower plates in the region that slipped 
during the 2014 Pisagua/Iquique earthquake sequence and immediately to 
the south, where an historic seismic gap remains unruptured in order to 
better understand how geologic structure controlled the initiation, 
propagation, and termination of this rupture sequence.
    The primary purpose of the central survey is to examine the extent 
and location of seafloor displacement and related subsurface fault 
movement related to the recent slip that occurred during the September 
16, 2015, Illapel earthquake. The scientists would compare the newly 
acquired data with previously collected data to determine where 
displacement occurred, how much occurred, and which sub-seafloor faults 
were most likely active during this event.
    The primary goal of the southern survey is to image the deep plate 
boundary thrust fault that can produce some of the world's largest 
earthquakes and tsunamis. This survey will image the characteristics of 
the plate-boundary thrust, sediment subduction, and upper plate 
structure within the 2010 Maule rupture segment and the 1960 Valdivia 
rupture area.

Dates and Duration

    The surveys off Chile are proposed for 2016/2017 and would take 
approximately 60 days with the potential for an additional increase in 
number of days by 25 percent as a contingency for equipment failures, 
resurveys, or other operational needs. The surveys may occur at any 
time during the proposed authorized period of June 2016 to June 2017. 
The proposed survey off northern Chile would consist of approximately 
45 days of science operations that include approximately 28 days of 
seismic operations, approximately 13 days of ocean bottom seismometer 
(OBS) deployment/retrieval, and approximately four days of transit and 
towed equipment deployment/retrieval. The central proposed survey would 
involve approximately six days, including approximately five days of 
seismic operations and approximately one day of equipment deployment/
retrieval time. The southern proposed survey would involve 
approximately 32 days of science operations including approximately 27 
days of seismic operations, and approximately five days of transit and 
towed equipment deployment/retrieval. As described above, the proposed 
surveys may occur at any time during the proposed authorized period of 
June 2016 to June 2017; however the proposed southern survey would most 
likely not occur between February and April.
    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

    The proposed survey off northern Chile would occur within the area 
located at approximately 70.2-73.2[deg] W., 18.3-22.4[deg] S., the 
central proposed survey would occur within approximately 71.8-73.4[deg] 
W., 30.1-33.9[deg] S., and the southern proposed survey would occur 
within approximately 72.2-76.1[deg] W., 33.9-44.1[deg] S.
    Representative survey tracklines are shown in Figure 1 in this 
notice and described further in Lamont-Doherty's application. Some 
deviation in actual track lines could be necessary for reasons such as 
science drivers, poor data quality, inclement weather, or mechanical 
issues with the research vessel and/or equipment. Water depths in the 
proposed survey areas range from approximately 50 to 7,600 m (164 to 
25,000 ft). The proposed seismic surveys would be conducted within the 
EEZ of Chile; only a small proportion of the surveys would take place 
in territorial waters (see Figure 1).

Figure 1--Survey Locations and Sample Tracklines

[[Page 23120]]

[GRAPHIC] [TIFF OMITTED] TN19AP16.000

Principal and Collaborating Investigators

    The northern survey's Principal Investigator (PI) is Dr. A. Trehu 
(OSU) collaborating with Drs. E. Contreras-Reyes, E. Vera, and D. Comte 
(Universidad de Chile) and H. Kopp and D. Lange (Research Center for 
Marine Geosciences, GEOMAR, Helmholtz Centre for Ocean Research). The 
central and southern surveys PIs are Drs. N. Bangs (UT) and A. Trehu, 
participating with Drs. E. Contreras-Reyes and E. Vera.

Detailed Description of the Specified Activities

Transit Activities

    The Langseth would transit to and from the survey locations from 
either a local port, or another research survey location in the region. 
The transit start and return points would be determined as the project 
schedule becomes

[[Page 23121]]

finalized and may vary based on logistics, timing, or other factors.

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

    A total of approximately 9,633 km (5,986 mi) of transect lines 
would be surveyed in the southeast Pacific Ocean: Approximately 4,543 
km (2,823 mi) off northern Chile, approximately 791 km (491 mi) during 
the central survey, and approximately 4,299 km (2,671 mi) during the 
southern survey. There could be additional seismic operations 
associated with turns, airgun testing, and repeat coverage of any areas 
where initial data quality is sub-standard.
    During the survey, the Langseth would deploy 36 airguns as an 
energy source with a total volume of 6,600 in\3\. The receiving system 
would consist of up to 68 OBSs deployed for the northern survey site, 
and a single 8- to 15-km (5-8.3 mi) hydrophone streamer for all 
surveys. 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.
    In addition to the operations of the airgun array, the ocean floor 
would be mapped with the Kongsberg EM 122 MBES and a Knudsen Chirp 3260 
SBP. The proposed action will also include the use of an unmanned 
submersible vehicle for data collection. A Liquid Robotics SV2 Wave 
Glider could be used during the surveys for a period of several hours 
to collect data from seafloor sensors. An integrated acoustic 
transceiver communicates from the platform to a subsea-mounted acoustic 
data logger (ADL); the ADL then transfers data to a station on the 
platform, which transmits them to a control center via satellite. The 
SV2 Wave Glider platform is 2.1 m long and 60 cm wide (6.9 ft by 2ft).

Seismic Airguns

    The Langseth's full array of airguns consists of four strings with 
36 airguns (plus 4 spares), and a total volume of approximately 6,600 
in\3\. 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). The airguns are fully detailed in Sec.  
2.2.3.1 of NSF's PEIS.
    During the survey, Lamont-Doherty would plan to use the full array 
with most of the airguns in inactive mode. The 4-string array would be 
towed at a depth of 9 to 12 m (30 to 39 ft) during the northern 
proposed survey; the central and southern proposed surveys would use a 
tow depth of 9 m (30 ft). The shot intervals would range from 25 to 50 
m (82 to 164 ft) for multi-channel seismic (MCS) acquisition, 100-150 m 
(328-492 ft) for simultaneous MCS and tomography acquisition, and 300 m 
(984 ft) for tomography acquisition. 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

[[Page 23122]]

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 50-
54 OBS during the northern survey at a nominal 15-km (9.3 mi) spacing 
interval. 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 in).
    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 Three Proposed Survey Areas Within the Southeast Pacific Ocean
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Species                 Regulatory status 1 2     Species abundance \3\        Local occurrence                     Habitat
--------------------------------------------------------------------------------------------------------------------------------------------------------
Antarctic minke whale (Balaenoptera  MMPA--NC, ESA--NL.....  515,000....................  North--Rare, Central/   Coastal, pelagic.
 bonaerensis).                                                                             South--Uncommon.
Blue whale (B. musculus)...........  MMPA--D, ESA--EN......  10,000 \4\.................  North--Common, Central/ Coastal, shelf, pelagic.
                                                                                           South--Common.
Bryde's whale (Balaenoptera edeni).  MMPA--NC, ESA--NL.....  43,633 \5\.................  North--Common, Central/ Coastal, pelagic.
                                                                                           South--Common.
Common minke whale (B.               MMPA--NC, ESA--NL.....  515,000....................  North--Rare, Central/   Coastal, pelagic.
 acutorostrata).                                                                           South--Uncommon.
Fin whale (B. physalus)............  MMPA--D, ESA--EN......  22,000.....................  North--Rare, Central/   Shelf, slope, pelagic.
                                                                                           South--Common.
Humpback whale (Megaptera            MMPA--D, ESA--EN......  42,000.....................  North--Common, Central/ Coastal, shelf, pelagic.
 novaengliae).                                                                             South--Common.
Pygmy right whale (Caperea           MMPA--NC, ESA--NL.....  Unknown....................  North--Unknown,         Coastal, oceanic.
 marginata).                                                                               Central/South--Rare.
Sei whale (B. borealis)............  MMPA--D, ESA--EN......  10,000.....................  North--Uncommon,        Pelagic.
                                                                                           Central/South--
                                                                                           Uncommon.
Southern right whale (Eubalaena      MMPA--D, ESA--EN......  12,000.....................  North--Rare, Central/   Coastal, oceanic.
 australis).                                                                               South--Rare.
Sperm whale (Physeter                MMPA--D, ESA--EN......  355,000 \6\................  North--Common, Central/ Pelagic, deep seas.
 macrocephalus).                                                                           South--Common.
Dwarf sperm whale (Kogia sima).....  MMPA--NC, ESA--NL.....  170,309 \7\................  North--Rare, Central/   Shelf, pelagic.
                                                                                           South--Rare.
Pygmy sperm whale (K. breviceps)...  MMPA--NC, ESA--NL.....  170,309 \7\................  North--Rare, Central/   Shelf, pelagic.
                                                                                           South--Rare.
Andrew's beaked whale (Mesoplodon    MMPA--NC, ESA--NL.....  25,300 \8\.................  North--Unknown,         Pelagic.
 bowdoini).                                                                                Central/South--Rare.
Blainville's beaked whale (M.        MMPA--NC, ESA--NL.....  25,300 \8\.................  North--Uncommon,        Pelagic.
 densirostris).                                                                            Central/South--
                                                                                           Uncommon.
Cuvier's beaked whale (Ziphius       MMPA--NC, ESA--NL.....  20,000 \8\.................  North--Uncommon,        Slope, pelagic.
 cavirostris).                                                                             Central/South--
                                                                                           Uncommon.
Gray's beaked whale (M. grayi).....  MMPA--NC, ESA--NL.....  25,300 \8\.................  North--Rare, Central/   Pelagic.
                                                                                           South--Rare.
Hector's beaked whale (M. hectori).  MMPA--NC, ESA--NL.....  25,300 \8\.................  North--Unknown,         Pelagic.
                                                                                           Central/South--Rare.

[[Page 23123]]

 
Pygmy beaked whale (Mesoplodon       MMPA--NC, ESA--NL.....  25,300 \8\.................  North--Rare, Central/   Pelagic.
 peruvianus).                                                                              South--Rare.
Shepherd's beaked whale (Tasmacetus  MMPA--NC, ESA--NL.....  25,300 \8\.................  North--Unknown,         Pelagic.
 shepherdi).                                                                               Central/South--Rare.
Spade-toothed whale (Mesoplodon      MMPA--NC, ESA--NL.....  25,300 \8\.................  North--Unknown,         Pelagic.
 traversii).                                                                               Central/South--Rare.
Strap-toothed beaked whale (M.       MMPA--NC, ESA--NL.....  25,300 \8\.................  North--Unknown,         Pelagic.
 layardii).                                                                                Central/South--Rare.
Southern bottlenose whale            MMPA--NC, ESA--NL.....  72,000 \9\.................  North--Unknown,         Pelagic.
 (Hyperoodon planifrons).                                                                  Central/South--
                                                                                           Uncommon.
Chilean dolphin (Cephalorhynchus     MMPA--NC, ESA--NL.....  10,000.....................  North--Unknown,         Coastal.
 eutropia).                                                                                Central/South--
                                                                                           Uncommon.
Rough-toothed dolphin (Steno         MMPA--NC, ESA--NL.....  107,633 \10\...............  North--Rare, Central/   Oceanic.
 bredanensis).                                                                             South--Unknown.
Common bottlenose dolphin (Tursiops  MMPA--NC, ESA--NL.....  335,834 \10\...............  North--Abundant,        Coastal, pelagic, shelf.
 truncatus).                                                                               Central/South--Common.
Striped dolphin (S. coeruleoalba)..  MMPA--NC, ESA--NL.....  964,362 \10\...............  North--Abundant,        Shelf edge, pelagic.
                                                                                           Central/South--Common.
Short-beaked common dolphin          MMPA--NC, ESA--NL.....  1,766,551 \11\.............  North--Abundant,        Coastal, shelf.
 (Delphinus delphis).                                                                      Central/South--
                                                                                           Abundant.
Long-beaked common dolphin           MMPA--NC, ESA--NL.....  144,000 \12\...............  North--Uncommon,        Coastal, shelf.
 (Delphinus capensis).                                                                     Central/South--
                                                                                           Unknown.
Dusky dolphin (Lagenorhynchus        MMPA--NC, ESA--NL.....  25,880 \13\................  North--Abundant,        Shelf, slope.
 obscurus).                                                                                Central/South--
                                                                                           Abundant.
Peale's dolphin (Lagenorhynchus      MMPA--NC, ESA--NL.....  Unknown....................  North--Unknown,         Coastal.
 australis).                                                                               Central/South--
                                                                                           Uncommon.
Hourglass dolphin (Lagenorhynchus    MMPA--NC, ESA--NL.....  144,300 \14\...............  North--Unknown,         Pelagic.
 cruciger).                                                                                Central/South--Rare.
Southern right whale dolphin         MMPA--NC, ESA--NL.....  Unknown....................  North--Uncommon,        Pelagic.
 (Lissodelphis peronii).                                                                   Central/South--Common.
Risso's dolphin (Grampus griseus)..  MMPA--NC, ESA--NL.....  110,457 \10\...............  North--Common, Central/ Shelf, slope.
                                                                                           South--Uncommon.
Pygmy killer whale (Feresa           MMPA--NC, ESA--NL.....  38,900 \8\.................  North--Rare, Central/   Oceanic, pantropical.
 attenuate).                                                                               South--Uncommon.
False killer whale (Pseudorca        MMPA--NC, ESA--NL.....  39,800 \8\.................  North--Uncommon,        Pelagic.
 crassidens).                                                                              Central/South--Rare.
Killer whale (Orcinus orca)........  MMPA--NC, ESA--NL.....  50,000.....................  North--Rare, Central/   Coastal, shelf, pelagic.
                                                                                           South--Rare.
Long-finned pilot whale              MMPA--NC, ESA--NL.....  200,000 \15\...............  North--Rare, Central/   Coastal, pelagic.
 (Globicephala melas).                                                                     South--Rare.
Short-finned pilot whale             MMPA--NC, ESA--NL.....  589,315 \16\...............  North--Rare, Central/   Coastal, pelagic.
 (Globicephala macrorhynchus).                                                             South--Rare.
Burmeister's porpoise (Phocoena      MMPA--NC, ESA--NL.....  Unknown....................  North--Coastal,         Coastal.
 spinipinnis).                                                                             Central/South--
                                                                                           Coastal.
Juan Fernandez fur seal              MMPA--NC, ESA--NL.....  32,278 \17\................  North--Rare, Central/   Coastal, pelagic.
 (Arctocephalus philippii).                                                                South--Rare.
South American fur seal              MMPA--NC, ESA--NL.....  250,000....................  North--Rare, Central/   Coastal, shelf, slope.
 (Arctocephalus australis).                                                                South--Rare.
South American sea lion (Otaria      MMPA--NC, ESA--NL.....  397,771 \18\...............  North--Abundant,        Coastal, shelf.
 byronia).                                                                                 Central/South--
                                                                                           Abundant.
Southern elephant seal (Mirounga     MMPA--NC, ESA--NL.....  640,000 \19\...............  North--Abundant,        Coastal, pelagic.
 leonina).                                                                                 Central/South--
                                                                                           Abundant.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ MMPA: NC = Not classified; D = Depleted.
\2\ ESA: EN = Endangered, T = Threatened, DL = Delisted, NL = Not listed.
\3\ Except where noted best estimate abundance information obtained from the International Whaling Commission's whale population estimates (IWC, 2016)
  or from the International Union for Conservation of Nature and Natural Resources Red List of Threatened Species Web site (IUCN, 2016). Unknown =
  Abundance information does not exist for this species.
\4\ IUCN's best estimate of the global population is 10,000 to 25,000.
\5\ Estimate from IUCN's 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).
\6\ Whitehead (2002).
\7\ Estimate from IUCN's Web page for Kogia spp. Eastern Tropical Pacific (ETP) (150,000); Hawaii (19,172); Gulf of Mexico (742); and western Atlantic
  (395).
\8\ Wade and Gerrodette (1993).
\9\ South of 60[deg] S. from the 1885/1986-1990/1991 IWC/IDCR and SOWER surveys (Branch and Butterworth, 2001).
\10\ ETP, line-transect survey, August-December 2006 (Gerrodette et al., 2008).
\11\ ETP, southern stock, 2000 survey (Gerrodette and Forcada 2002).
\12\ Gerrodette and Palacios (1996) estimated 55,000 within Pacific coast waters of Mexico, 69,000 in the Gulf of California, and 20,000 off South
  Africa. IUCN, 2016.
\13\ IUCN, 2016 and Markowitz, 2004.
\14\ Kasamatsu and Joyce, 1995.

[[Page 23124]]

 
\15\ Abundance estimates for beaked, southern bottlenose, and pilot whales south of the Antarctic Convergence in January (Kasamatsu and Joyce, 1995).
\16\ Gerrodette and Forcada (2002).
\17\ 2005/2006 minimum population estimate (Osman, 2008).
\18\ Crespo et al. (2012). Current status of the South American sea lion along the distribution range.
\19\ Hindell and Perrin (2009).

    NMFS refers the public to Lamont-Doherty's application, NSF's draft 
environmental analysis (see ADDRESSES), 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., 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 44 marine mammals (9 Mysticetes, 31 odontocetes, and 
4 pinnipeds) would likely occur in the proposed action area. Table 2 
presents the classification of these species into their respected 
functional hearing group. NMFS considers 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 Southeast Pacific Ocean, 2016/
                    2017, by Functional Hearing group
                         [Southall et al., 2007]
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Low Frequency Hearing Range..  Antarctic minke, blue, Bryde's, common
                                (dwarf) minke, fin, humpback, Sei, pygmy
                                right, and Southern right whale.
Mid-Frequency Hearing Range..  Sperm whale; Cuvier's; Andrew's;
                                Blainville's, Gray's; Hector's; pygmy;
                                and Shepherd's beaked whale; strap
                                toothed; spade toothed; Southern
                                bottlenose whale; bottlenose; hourglass;
                                dusky; Peale's; rough-toothed; striped;
                                Chilean; Risso's; long-beaked common;
                                short-beaked common; and Southern right
                                whale dolphin; 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     Southern elephant seal; Southern American
 Range.                         sea lion; Subantarctic fur seal; and
                                Juan Fernandez fur seal.
------------------------------------------------------------------------


[[Page 23125]]

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 
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 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, 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).
    Evidence suggests that some marine mammals may 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, blue whales were shown to 
increase 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

[[Page 23126]]

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 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

[[Page 23127]]

     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 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

[[Page 23128]]

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. (1998, 2000) noted 
localized displacement during migration of four to five km (2.5 to 3.1 
mi) by traveling pods and seven to 12 km (4.3 to 7.5 mi) by more 
sensitive resting pods of cow-calf pairs. Avoidance distances with 
respect to the single airgun were smaller but consistent with the 
results from the full array in terms of the received sound levels. The 
mean received level for initial avoidance of an approaching airgun was 
140 dB re: 1 [micro]Pa for humpback pods containing females, and at the 
mean closest point of approach distance, the received level was 143 dB 
re: 1 [micro]Pa. The initial avoidance response generally occurred at 
distances of five to eight km (3.1 to 4.9 mi) from the airgun array and 
2 km (1.2 mi) from the single airgun. However, some individual humpback 
whales, especially males, approached within distances of 100 to 400 m 
(328 to 1,312 ft), where the maximum received level was 179 dB re: 1 
[micro]Pa.
    Data collected by observers during several of Lamont-Doherty's 
seismic surveys in the northwest Atlantic Ocean showed that sighting 
rates of humpback whales were significantly greater during non-seismic 
periods compared with periods when a full array was operating (Moulton 
and Holst, 2010). In addition, humpback whales were more likely to swim 
away and less likely to swim towards a vessel during seismic versus 
non-seismic periods (Moulton and Holst, 2010).
    Humpback whales on their summer feeding grounds in southeast Alaska 
did not exhibit persistent avoidance when exposed to seismic pulses 
from a 1.64-L (100-in\3\) airgun (Malme et al., 1985). Some humpbacks 
seemed ``startled'' at received levels of 150 to 169 dB re: 1 [mu]Pa. 
Malme et al. (1985) concluded that there was no clear evidence of 
avoidance, despite the possibility of subtle effects, at received 
levels up to 172 re: 1 [mu]Pa. However, Moulton and Holst (2010) 
reported that humpback whales monitored during seismic surveys in the 
northwest Atlantic had lower sighting rates and were most often seen 
swimming away from the vessel during seismic periods compared with 
periods when airguns were silent.
    Other studies have suggested that south Atlantic humpback whales 
wintering off Brazil may be displaced or even strand upon exposure to 
seismic surveys (Engel et al., 2004). However, the evidence for this 
was circumstantial and subject to alternative explanations (IAGC, 
2004). Also, the evidence was not consistent with subsequent results 
from the same area of Brazil (Parente et al., 2006), or with direct 
studies of humpbacks exposed to seismic surveys in other areas and 
seasons. After allowance for data from subsequent years, there was ``no 
observable direct correlation'' between strandings and seismic surveys 
(IWC, 2007: 236).

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

[[Page 23129]]

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, 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,

[[Page 23130]]

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 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 wellbeing. 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.

[[Page 23131]]

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 
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

[[Page 23132]]

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). There is no direct evidence of 
marine mammal stranding being caused by seismic surveys. We have 
considered the potential for the proposed seismic surveys to result in 
marine mammal stranding and have concluded that, based on the best 
available information, stranding is not expected to occur.

2. Potential Effects of the 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/3280 ft deep) or four (less than 1,000 m/
3280 ft 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 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 [mu]Pa, gray whales 
reacted by orienting slightly away from the source and being deflected 
from their course by approximately 200 m (656 ft)(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

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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.

3. Potential Effects of the Sub-Bottom Profiler

    Lamont-Doherty would also operate a sub-bottom profiler from the 
source vessel during the proposed survey. The profiler's sounds are 
very short pulses, occurring for one to four ms once every second. Most 
of the energy in the sound pulses emitted by the profiler is at 3.5 
kHz, and the beam is directed downward. The sub-bottom profiler on the 
Langseth has a maximum source level of 222 dB re: 1 [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.

4. 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 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

[[Page 23134]]

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.'' Based on the best available information, we 
do not believe vessel traffic associated with the proposed activities 
will result in the take of marine mammals; therefore vessel traffic is 
not discussed further in this document.

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). During seismic operations 
the Langseth will travel at approximately 4.5 kts (5.1 mph); the 
vessel's cruising speed outside of seismic operations is approximately 
10 kts (11.5 mph). Based on the best available information, we do not 
believe marine mammals will be struck by vessels as a result of the 
proposed activities; therefore vessel strike is not discussed further 
in this document.

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 relatively low risk of entanglement for 
marine mammals. Wildlife, especially slow moving animals, such as large 
whales, have a low probability of entanglement due to the low amount of 
slack in the lines, the slow speed of the survey vessel, and onboard 
monitoring. Pinnipeds and odontocetes are even less likely to be 
entangled than large whales due to their size, speed and agility. 
Lamont-Doherty has no recorded cases of entanglement of marine mammals 
during their conduct of over 12 years of seismic surveys (NSF, 2015). 
Based on the best available information, we do not believe entanglement 
of marine mammals will occur as a result of the proposed activities; 
therefore entanglement is not discussed further in this document.

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 
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

[[Page 23135]]

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 [29.5 ft] in the former case and less than 2 m [6.5 ft] 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.
    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

[[Page 23136]]

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 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

[[Page 23137]]

seismic research cruises as approved by us and detailed in the NSF's 
2011 PEIS and 2016 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).

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 Southeast Pacific Ocean
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                             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 (40 in\3\)..........  9 or 12...................  <100......................            \2\ 100            \2\ 100              1,041
                                                                     100 to 1,000..............                100                100                647
                                                                     >1,000....................                100                100                431
36-Airgun Array (6,600 in\3\)..........  9.........................  <100......................                591              2,060             22,580
                                                                     100 to 1,000..............                429              1,391              8,670
                                                                     >1,000....................                286                927              5,780

[[Page 23138]]

 
36-Airgun Array (6,600 in\3\)..........  12........................  <100......................                710              2,480             27,130
                                                                     100 to 1,000..............                522              1,674             10,362
                                                                     >1,000....................                348              1,116              6,908
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Predicted distances based on information presented in Lamont-Doherty's application.
\2\ NMFS required Lamont-Doherty to expand the exclusion zone for the mitigation airgun to 100 m (328 ft) in shallow water.

    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 to received levels that 
would constitute the exclusion and buffer zones were two to three times 
smaller than what Lamont-Doherty's modeling approach had 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 and we have concluded that the modeling of RMS distances 
likely results in predicted distances to acoustic thresholds (Table 3) 
that are conservative, i.e., if actual distances to received sound 
levels deviate from distances predicted via modeling, actual distances 
are expected to be lesser, not greater, than predicted distances

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 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

[[Page 23139]]

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.

[[Page 23140]]

Figure 2--Ramp-Up, Power Down, and Shut-Down Procedures for the 
Langseth
[GRAPHIC] [TIFF OMITTED] TN19AP16.001

Special Procedures for Concentrations of Large Whales

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

[[Page 23141]]

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 conduct marine mammal monitoring during 
the proposed project to supplement the proposed mitigation measures 
that include real-time monitoring (see ``Vessel-based Visual Mitigation 
Monitoring'' above), 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.

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 acoustic 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

[[Page 23142]]

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.
    3. 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.
    4. 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 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:

[[Page 23143]]

     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) of 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 sound 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 Tables 5-8 later in this notice.

            Table 4--NMFS' Current Acoustic Exposure Criteria
------------------------------------------------------------------------
                                       Criterion
            Criterion                 definition           Threshold
------------------------------------------------------------------------
Level A Harassment (Injury).....  Permanent           180 dB re 1
                                   Threshold Shift     microPa-m
                                   (PTS), (Any level   (cetaceans)/190
                                   above that which    dB re 1 microPa-m
                                   is known to cause   (pinnipeds) root
                                   TTS).               mean square
                                                       (rms).
Level B Harassment..............  Behavioral          160 dB re 1
                                   Disruption (for     microPa-m (rms).
                                   impulse noises).
------------------------------------------------------------------------

    NMFS' practice is to apply the 160 dB re: 1 [mu]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 
[mu]Pa (for cetaceans and pinnipeds, respectively) received level 
threshold for underwater impulse sound levels to predict whether 
permanent threshold shift (auditory injury), which we consider as 
harassment (Level A), 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 for us 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. We use this information to predict how many animals potentially 
could be 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, one 
assumption is that entirely new animals could be exposed every day, 
which results in a take estimate that in some circumstances 
overestimates the number of individuals harassed.
    The following sections describe Lamont-Doherty and NMFS' methods to 
estimate take by incidental harassment. We base these estimates on the 
number of marine mammals that are estimated to be exposed to seismic 
airgun sound levels above the Level B harassment threshold of 160 dB 
during a total of approximately 9,633 km (5,986 mi) of transect lines 
in the southeast Pacific Ocean.
    Density Estimates: Lamont-Doherty was unable to identify any 
systematic aircraft- or ship-based surveys conducted for marine mammals 
in waters of the southeast Pacific Ocean offshore Chile. Lamont-Doherty 
used densities from NMFS' Southwest Fisheries Science Center (SWFSC)

[[Page 23144]]

cruises (Ferguson and Barlow, 2001, 2003; Barlow 2003, 2010; Forney, 
2007) in the California Current which is similar to the Humboldt 
Current Coastal area in which the proposed surveys are located. Both 
are eastern boundary currents that feature narrow continental shelves, 
upwelling, high productivity, and fluctuating fishery resources 
(sardines and anchovies). The densities used were survey effort-
weighted means for the locations (blocks or states). In cases where 
multiple density estimates existed for an area, Lamont-Doherty used the 
highest density range (summer/fall) for each species within the survey 
area. We refer the reader to Lamont-Doherty's application for detailed 
information on how Lamont-Doherty calculated densities for marine 
mammals from the SWFSC cruises.
    For blue whales in the southern survey area, NMFS used the density 
(9.56/km\2\) reported by Galletti Vernazzani et al. (2012) for 
approximately four days of the proposed southern survey to account for 
potential survey operations occurring near a known foraging area 
between 39[deg] S. and 44[deg] S. For the remaining 31 days of the 
proposed survey, NMFS used the density estimate presented in Lamont-
Doherty's application (2.07/km\2\). NMFS considers Lamont-Doherty's 
approach to calculating densities for the remaining marine mammal 
species in the survey areas as the best available information. We 
present the estimated densities (when available) in Tables 5, 6, and 7 
in this notice.
    Modeled Number of Instances of Exposures: Lamont-Doherty would 
conduct the proposed seismic surveys offshore Chile in the southeast 
Pacific Ocean and 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 in Tables 3, 4, and 5 in their application. NMFS has 
independently reviewed these estimates and presents revised estimates 
(described in the following subsections) 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 in Tables 5, 6, and 7 in this notice. Table 8 presents 
the total numbers of instances of take that NMFS proposes to authorize.
    Take Estimate Method for Species with Density Information: Briefly, 
we take the estimated density of marine mammals within an area 
(animals/km\2\) and multiply that number by the daily ensonified area 
(km\2\). The product (rounded) is the number of instance of take within 
one day. We then multiply the number of instances of take within one 
day by the number of survey days (plus 25 percent contingency). The 
result is an estimate of the potential number of instances that marine 
mammals could be exposed to airgun sounds above the Level B harassment 
threshold (i.e., the 160 dB ensonified area minus the 180/190-dB 
ensonified area) and the Level A harassment threshold (i.e., the 180/
190-dB ensonified area only) over the duration of each proposed survey.
    There is some uncertainty about the representativeness of the 
estimated density data and the assumptions used in their calculations. 
Oceanographic conditions, including occasional El Ni[ntilde]o and La 
Ni[ntilde]a events, influence the distribution and numbers of marine 
mammals present in the eastern tropical Pacific Ocean, resulting in 
considerable year-to-year variation in the distribution and abundance 
of many marine mammal species. Thus, for some species, the densities 
derived from past surveys may not be representative of the densities 
that would be encountered during the proposed seismic surveys. However, 
the approach used is based on the best available data.
    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 three periods (northern: 35 
days; central: 6 days; and southern: 34 days) including 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).
    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 75 total survey 
days. Those species include: Bryde's, dwarf sperm, killer, and sei 
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 Bryde's 
whale (2), dwarf sperm whale (2), killer whale (4), and sei whale (3) 
to derive a reasonable estimate of take for eruptive occurrences of 
each these species only once for each survey.
    Take Estimates for Species with No Density Information: Density 
information for the southern right whale, pygmy right whale, Antarctic 
minke whale, sei whale, dwarf sperm whale, Shephard's beaked whale, 
pygmy beaked whale, southern bottlenose whale, hourglass dolphin, pygmy 
killer whale, false killer whale; short-finned pilot whale, Juan 
Fernandez fur seal, and southern elephant seal in the southeast Pacific 
Ocean is data poor or non-existent. When density estimates were not 
available for a particular survey leg, 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) and from Santora (2012) to 
estimate mean group size and take for these species. NMFS assumed that 
Lamont-Doherty could potentially encounter one group of each species 
each day during the seismic survey. NMFS believes it is reasonable to 
use the average (mean) group size (weighted by effort and rounded up) 
for each species multiplied by the number of survey days to derive an 
estimate of take from potential encounters.

[[Page 23145]]



   Table 5--Densities of Marine Mammals and Estimates of Incidents of Exposure to >=160 and 180 or 190 dB re 1
  [mu]Pa rms Predicted During the Northern Proposed Seismic Survey in the Southeast Pacific Ocean in 2016/2017
----------------------------------------------------------------------------------------------------------------
                                                                 Modeled number
                                                                 of instances of
                                                    Density       exposures to    Proposed Level  Proposed Level
                    Species                      estimate \1\     sound levels      A take \3\        B take
                                                                 >=160, 180, and
                                                                   190 dB \2\
----------------------------------------------------------------------------------------------------------------
Southern right whale..........................               0         105, 0, -               0             105
Humpback whale................................            0.32          35, 0, -               0              35
Common (dwarf) minke whale....................            0.34           35, 0 -               0              35
Antarctic minke whale.........................               0          70, 0, -               0              70
Bryde's whale.................................            0.47          35, 0, 0               0              35
Sei whale.....................................               0         105, 0, -               0             105
Fin whale.....................................             1.4        105, 35, -              35             105
Blue whale....................................            0.54          35, 0, -               0              35
Sperm whale...................................            1.19          70, 0, -               0              70
Dwarf sperm whale.............................            8.92       630, 105, -             105             630
Pygmy sperm whale.............................            2.73        210, 35, -              35             210
Cuvier's beaked whale.........................            2.36        175, 35, -              35             175
Pygmy beaked whale............................             0.7          35, 0, -               0              35
Gray's beaked whale...........................            1.95        140, 35, -              35             140
Blainville's beaked whale.....................            1.95        140, 35, -              35             140
Rough-toothed dolphin.........................            7.05       490, 105, -             105             490
Common bottlenose dolphin.....................            18.4     1,330, 245, -             245           1,330
Striped dolphin...............................            61.4     4,410, 805, -             805           4,410
Short-beaked common dolphin...................           356.3  25,515, 4,725, -           4,725          25,515
Long-beaked common dolphin....................            50.3     3,605, 665, -             665           3,605
Dusky dolphin.................................            13.7       980, 175, -             175             980
Southern right whale dolphin..................            3.34        245, 35, -              35             245
Risso's dolphin...............................            29.8     2,135, 385, -             385           2,135
Pygmy killer whale............................            1.31         105, 0, -               0             105
False killer whale............................            0.63          35, 0, -               0              35
Killer whale..................................            0.23           4, 0, -               0               4
Short-finned pilot whale......................               0         700, 0, -               0             700
Long-finned pilot whale.......................            1.09          70, 0, -               0              70
Burmeister's porpoise.........................            5.15        385, 70, -              70             385
Juan Fernandez fur seal.......................               0          70, -, 0               0              70
South American fur seal.......................            37.9     2,730, -, 490             490           2,730
South American sea lion.......................             393  28,140, -, 5,215           5,215          28,140
----------------------------------------------------------------------------------------------------------------
\1\ Densities shown (when available) are 1,000 animals per km\2\. See Lamont-Doherty's application and text in
  this notice for a summary of how Lamont-Doherty derived density estimates for certain species. For species
  without density estimates, see text in this notice for an explanation of NMFS' methodology to derive take
  estimates.
\2\ Take modeled using a daily method for calculating ensonified area: Estimated density multiplied by the daily
  ensonified area to derive instances of take in one day (rounded) multiplied by the number of survey days with
  25 percent contingency (35) Level B take = modeled instances of exposure within the 160-dB ensonified area
  minus the 180-dB or 190-dB ensonified area. Level A take = modeled instances of exposures within the 180-dB or
  190-dB ensonified area only. Modeled instances of exposures include adjustments for species with no density
  information or with species having less than one instance of exposure (see text for sources).
\3\ 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 or 190 dB exclusion zone while the airguns are active.


   Table 6--Densities of Marine Mammals and Estimates of Incidents of Exposure to >=160 and 180 or 190 dB re 1
   [mu]Pa rms Predicted During the Central Proposed Seismic Survey in the Southeast Pacific Ocean in 2016/2017
----------------------------------------------------------------------------------------------------------------
                                                                 Modeled number
                                                                 of instances of
                                                    Density       exposures to    Proposed Level  Proposed Level
                    Species                      estimate \1\     sound levels      A take \3\        B take
                                                                 >=160, 180, and
                                                                   190 dB \2\
----------------------------------------------------------------------------------------------------------------
Southern right whale..........................               0          18, 0, -               0              18
Pygmy right whale.............................               0          18, 0, -               0              18
Humpback whale................................            0.43           6, 0, -               0               6
Common (dwarf) minke whale....................            0.34           6, 0, -               0               6
Antarctic minke whale.........................               0          12, 0, -               0              12
Bryde's whale.................................            0.41           6, 0, -               0               6
Sei whale.....................................               0          18, 0, -               0              18
Fin whale.....................................            1.96          18, 6, -               6              18
Blue whale....................................             2.1          18, 6, -               6              18
Sperm whale...................................            1.22          12, 0, -               0              12

[[Page 23146]]

 
Dwarf sperm whale.............................            7.98         78, 12, -              12              78
Pygmy sperm whale.............................            2.98          30, 6, -               6              30
Cuvier's beaked whale.........................            3.02          30, 6, -               6              30
Shepard's beaked whale........................               0          18, 0, -               0              18
Hector's beaked whale.........................            1.54          18, 0, -               0              18
Pygmy beaked whale............................            0.55           6, 0, -               0               6
Gray's beaked whale...........................            1.54          18, 0, -               0              18
Blainville's beaked whale.....................            1.54          18, 0, -               0              18
Andrew's beaked whale.........................            1.54          18, 0, -               0              18
Strap-toothed beaked whale....................            1.54          18, 0, -               0              18
Spade-toothed beaked whale....................            1.54          18, 0, -               0              18
Chilean dolphin...............................            21.2        210, 36, -              36             210
Common bottlenose dolphin.....................            12.3        120, 24, -              24             120
Striped dolphin...............................            46.7        462, 84, -              84             462
Short-beaked common dolphin...................           503.5     4,998, 908, -             906           4,998
Dusky dolphin.................................            14.8        144, 24, -              24             144
Peale's dolphin...............................            21.2        210, 36, -              36             210
Hourglass dolphin.............................               0          30, 0, -               0              30
Southern right whale dolphin..................            6.07         60, 12, -              12              60
Risso's dolphin...............................            21.2        210, 36, -              36             210
Pygmy killer whale............................               0          12, 0, -               0              12
False killer whale............................            0.54           6, 0, -               0               6
Killer whale..................................            0.28           4, 0, -               0               4
Short-finned pilot whale......................               0         120, 0, -               0             120
Long-finned pilot whale.......................            0.94          12, 0, -               0              12
Burmeister's porpoise.........................            4.92          48, 6, -               6              48
Juan Fernandez fur seal.......................               0          12, -, 0               0              12
South American fur seal.......................            37.9        378, -, 66              66             378
South American sea lion.......................             393     3,900, -, 708             708           3,900
Southern elephant seal........................               0          24, -, 0               0              24
----------------------------------------------------------------------------------------------------------------
\1\ Densities shown (when available) are 1,000 animals per km\2\. See Lamont-Doherty's application and text in
  this notice for a summary of how Lamont-Doherty derived density estimates for certain species. For species
  without density estimates, see text in this notice for an explanation of NMFS' methodology to derive take
  estimates.
\2\ Take modeled using a daily method for calculating ensonified area: Estimated density multiplied by the daily
  ensonified area to derive instances of take in one day (rounded) multiplied by the number of survey days with
  25 percent contingency (35) Level B take = modeled instances of exposure within the 160-dB ensonified area
  minus the 180-dB or 190-dB ensonified area. Level A take = modeled instances of exposures within the 180-dB or
  190-dB ensonified area only. Modeled instances of exposures include adjustments for species with no density
  information or with species having less than one instance of exposure (see text for sources).
\3\ 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 or 190 dB exclusion zone while the airguns are active.


   Table 7--Densities of Marine Mammals and Estimates of Incidents of Exposure to >=160 and 180 or 190 dB re 1
  [mu]Pa rms Predicted During the Southern Proposed Seismic Survey in the Southeast Pacific Ocean in 2016/2017
----------------------------------------------------------------------------------------------------------------
                                                      Modeled number of
                                 Density estimate   instances of exposures   Proposed Level A   Proposed Level B
            Species                    \1\          to sound levels >=160,       take \3\             take
                                                     180, and 190 dB \2\
----------------------------------------------------------------------------------------------------------------
Southern right whale..........                  0                102, 0, -                  0                102
Pygmy right whale.............                  0                102, 0, -                  0                102
Humpback whale................               1.22                102, 0, -                  0                102
Common (dwarf) minke whale....               0.61                 34, 0, -                  0                 34
Antarctic minke whale.........                  0                 68, 0, -                  0                 68
Bryde's whale.................               0.03                  2, 0, -                  0                  2
Sei whale.....................               0.02                  3, 0, -                  0                  3
Fin whale.....................               2.43               170, 34, -                 34                170
Blue whale (Feb-Apr)..........               9.56                80, 12, -                 12                 80
Blue whale (May-Jan)..........               2.07               124, 31, -                 31                124
Sperm whale...................               1.32                102, 0, -                  0                102
Dwarf sperm whale.............                  0                 68, 0, -                  0                 68
Pygmy sperm whale.............               4.14               306, 34, -                 34                306
Cuvier's beaked whale.........               4.02               272, 34, -                 34                272

[[Page 23147]]

 
Shepard's beaked whale........                  0                102, 0, -                  0                102
Hector's beaked whale.........               0.31                 34, 0, -                  0                 34
Pygmy beaked whale............                  0                102, 0, -                  0                102
Gray's beaked whale...........               1.95               136, 34, -                 34                136
Blainville's beaked whale.....               0.31                 34, 0, -                  0                 34
Andrew's beaked whale.........               0.31                 34, 0, -                  0                 34
Strap-toothed beaked whale....               0.31                 34, 0, -                  0                 34
Spade-toothed beaked whale....               0.31                 34, 0, -                  0                 34
Southern bottlenose whale.....                  0                102, 0, -                  0                102
Chilean dolphin...............               10.9              748, 136, 0                136                748
Common bottlenose dolphin.....               2.72               204, 34, -                 34                204
Striped dolphin...............               17.7            1,224, 204, -                204              1,224
Short-beaked common dolphin...              516.9         36,210, 5,950, -              5,950             36,210
Dusky dolphin.................               29.9            2,108, 340, -                340              2,108
Peale's dolphin...............               10.9              748, 136, -                136                748
Hourglass dolphin.............                  0                170, 0, -                  0                170
Southern right whale dolphin..               9.79              680, 102, -                102                680
Risso's dolphin...............               10.9              748, 136, -                136                748
Pygmy killer whale............                  0                 68, 0, -                  0                 68
False killer whale............                  0                238, 0, -                  0                238
Killer whale..................               0.73                 68, 0, -                  0                 68
Short-finned pilot whale......                  0                680, 0, -                  0                680
Long-finned pilot whale.......               0.53                 34, 0, -                  0                 34
Burmeister's porpoise.........               55.4            3,876, 646, -                646              3,876
Juan Fernandez fur seal.......                  0                 68, -, 0                  0                 68
South American fur seal.......               37.9            2,652, -, 442                442              2,652
South American sea lion.......                393         27,540, -, 4,522              4,522             27,540
Southern elephant seal........                  0                136, -, 0                  0                136
----------------------------------------------------------------------------------------------------------------
\1\ Densities shown (when available) are 1,000 animals per km\2\. See Lamont-Doherty's application and text in
  this notice for a summary of how Lamont-Doherty derived density estimates for certain species. For species
  without density estimates, see text in this notice for an explanation of NMFS' methodology to derive take
  estimates.
\2\ Take modeled using a daily method for calculating ensonified area: Estimated density multiplied by the daily
  ensonified area to derive instances of take in one day (rounded) multiplied by the number of survey days with
  25 percent contingency (35) Level B take = modeled instances of exposure within the 160-dB ensonified area
  minus the 180-dB or 190-dB ensonified area. Level A take = modeled instances of exposures within the 180-dB or
  190-dB ensonified area only. Modeled instances of exposures include adjustments for species with no density
  information or with species having less than one instance of exposure (see text for sources).
\3\ 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 or 190 dB exclusion zone while the airguns are active.


  Table 8--Take Estimates Based on Total Predicted Incidents of Exposure to >=160 and 180 or 190 dB re 1 [mu]Pa
 rms During the Northern, Central, and Southern Proposed Seismic Survey Off Chile in the Southeast Pacific Ocean
                                                  in 2016/2017
----------------------------------------------------------------------------------------------------------------
                                                     Proposed
                     Species                       Level A  take     Proposed          Total        Percent of
                                                        \1\        Level B  take  proposed  take  population \2\
----------------------------------------------------------------------------------------------------------------
Southern right whale............................               0             225             225           1.875
Pygmy right whale...............................               0             120             120         Unknown
Humpback whale..................................               0             143             143           0.340
Common (dwarf) minke whale......................               0              75              75           0.015
Antarctic minke whale...........................               0              41              41           0.008
Bryde's whale...................................               0              43              43           0.099
Sei whale.......................................               0             126             126           1.260
Fin whale.......................................              75             293             368           1.673
Blue whale......................................              49             257             306           3.060
Sperm whale.....................................               0             184             184           0.051
Dwarf sperm whale...............................             117             776             893           0.524
Pygmy sperm whale...............................              75             546             621           0.365
Cuvier's beaked whale...........................              75             477             552           2.760
Shepard's beaked whale..........................               0             120             120           0.474
Pygmy beaked whale..............................               0             143             143           0.565
Gray's beaked whale.............................              69             294             363           1.435
Blainville's beaked whale.......................              35             192             227           0.897
Hector's beaked whale...........................               0              52              52           0.206
Gray's beaked whale.............................              69             294             363           1.435

[[Page 23148]]

 
Andrew's beaked whale...........................               0              52              52           0.206
Strap-toothed beaked whale......................               0              52              52           0.206
Spade-toothed beaked whale......................               0              52              52           0.206
Southern bottlenose whale.......................               0             102             102           0.142
Chilean dolphin.................................             172             958           1,130          11.300
Rough-toothed dolphin...........................             105             490             595           0.553
Common bottlenose dolphin.......................             303           1,654           1,957           0.583
Striped dolphin.................................           1,093           6,096           7,189           0.745
Short-beaked common dolphin.....................          11,581          66,723          78,304           4.433
Long-beaked common dolphin......................             665           3,605           4,270           2.965
Dusky dolphin...................................             539           3,232           3,771          14.571
Peale's dolphin.................................             172             958           1,130         Unknown
Hourglass dolphin...............................               0             200             200           0.139
Southern right whale dolphin....................             149             985           1,134         Unknown
Risso's dolphin.................................             557           3,093           3,650           3.304
Pygmy killer whale..............................               0             185             185           0.476
False killer whale..............................               0             279             279           0.701
Killer whale....................................               0              76              76           0.152
Short-finned pilot whale........................               0           1,500           1,500           0.255
Long-finned pilot whale.........................               0             116             116           0.058
Burmeister's porpoise...........................             722           4,309           5,031         Unknown
Juan Fernandez fur seal.........................               0             150             150           0.465
South American fur seal.........................             998           5,760           6,758           2.703
South American sea lion.........................          10,445          59,580          70,025          17.604
Southern elephant seal..........................               0             160             160           0.040
----------------------------------------------------------------------------------------------------------------
\1\ 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 or 190 dB exclusion zone while the airguns are active.
\2\ Proposed authorized Level A and B takes (used by NMFS as proxy for number of individuals exposed) expressed
  as the percent of the population listed in Table 1 in this notice. Unknown = Abundance size not available.

    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.
    As described above, NMFS considers the probability for entanglement 
of marine mammals to be so low as to be discountable, because of the 
vessel speed and the monitoring efforts onboard the survey vessel. 
Therefore, NMFS does not propose to authorize additional takes for 
entanglement.
    As described above, 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 avoidance 
where safe. Therefore, NMFS does not anticipate nor do we propose to 
authorize takes of marine mammals as a result of 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 8, 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

[[Page 23149]]

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 southeast Pacific 
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, as 
NMFS expects that successful implementation of the proposed 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, given sufficient notice of the Langseth's approach 
due to the vessel's relatively low speed when conducting seismic 
surveys. Though NMFS expects that Level A harassment is unlikely to 
occur at the numbers proposed to be authorized, is difficult to 
quantify the degree to which the mitigation and avoidance will reduce 
the number of animals that might incur PTS, therefore we propose to 
authorize, and have included in our analyses, 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 of the animals, as well as the fact that the vessel is not 
expected to remain in any one area in which individuals would be 
expected to concentrate for any extended amount of time (i.e., since 
the duration of exposure to loud sounds will be relatively short), we 
anticipate that any PTS that may be incurred in marine mammals would be 
in the form of only a small degree of permanent threshold shift, and 
not total deafness, that would not be likely to affect the fitness of 
any individuals.
    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, and sperm whales. 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 to the low frequency signals of 
these airguns than that of mysticetes. NMFS generally expects cetaceans 
to move away from a noise source that is annoying prior to its becoming 
potentially injurious, and this expectation is expected to hold true in 
the case of the proposed activities, especially given the relatively 
slow travel speed of the Langseth while seismic surveys are being 
conducted (4.5 kt; 5.1 mph). The relatively slow ship speed is expected 
to provide cetaceans with sufficient notice of the oncoming vessel and 
thus sufficient opportunity to avoid the seismic sound source before it 
reaches a level that would be potentially injurious to the animal. 
However, as described above, Level A takes for a small group of 
cetacean 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 the feeding success of any individuals long-term. Regarding 
direct effects on cetacean feeding, based on the fact that the action 
footprint does not include any areas recognized specifically for higher 
value feeding habitat, the mobile and ephemeral nature of most prey 
sources, and the size of the southeast Pacific 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 
are expected to be minor based on the fact that other equally valuable 
feeding opportunities likely exist nearby.
    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 based on the best available information, any behaviors 
that are interrupted during the activity are expected to resume once 
the activity ceases. For example, as described above, 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 in that area for decades (Appendix A 
in Malme et al., 1984; Richardson et al., 1995; Allen and Angliss, 
2014). Similarly, bowhead whales have continued to travel to the 
eastern Beaufort Sea each summer, and their numbers have increased 
notably, despite seismic exploration in their summer and autumn range 
for many years (Richardson et al., 1987; Allen and Angliss, 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. Only a small 
portion of marine mammal habitat will be affected at any time, and 
other areas within the southeast Pacific Ocean would be available for 
necessary biological functions. Overall, the consequences of behavioral 
modification are not expected to affect cetacean growth, survival, and/
or reproduction, and therefore are not expected to be biologically 
significant.
    Pinnipeds. Generally speaking, pinnipeds may react to a sound 
source 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, with behavioral responses to sound ranging from a mild 
orienting response, or a shifting of attention, to flight and panic. 
However, research and monitoring observations from activities similar 
to those proposed have shown that pinnipeds in the water are generally 
tolerant of anthropogenic noise and activity. Visual monitoring from 
seismic vessels has shown only slight (if any) avoidance of airguns by 
pinnipeds and only slight (if any) changes in behavior (Harris et al., 
2001; Moulton and Lawson, 2002). 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 effects to sound 
are generally more likely to occur at higher received levels (i.e., 
within a few kilometers of a sound source). However, the slow speed of 
the Langseth while conducting seismic surveys (approximately 4.5 kt; 
5.1 mph) is expected to provide ample opportunity for pinnipeds to 
avoid and keep some distance between themselves and the loudest sources 
of sound associated with the proposed activities. Additionally, 
underwater sound from the proposed survey would not be audible at 
pinniped haulouts or rookeries, therefore the consequences of 
behavioral responses in these areas are expected to be minimal. 
Overall, the consequences of behavioral modification are not expected 
to affect

[[Page 23150]]

pinniped growth, survival, and/or reproduction, and therefore are not 
expected to be biologically significant.
    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 75 
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 proposed 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 around the seismic vessel;
     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), any PTS that is 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.
    Tables 5-8 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, 44 species 
of marine mammals under our jurisdiction. NMFS estimates that Lamont-
Doherty's activities could potentially affect, by Level A harassment, 
up to 26 species of marine mammals under our jurisdiction.
    For each species, the numbers of take being proposed for 
authorization are small relative to the population sizes: Less than 18 
percent for South American sea lion, less than 15 percent for the dusky 
dolphin, less than 11.5 percent for Chilean dolphin, and less than 5 
percent for all other species (Table 8).
    NMFS is not aware of reliable abundance estimates for four species 
of marine mammals (Burmeister's porpoise, Peale's dolphin, pygmy right 
whale, and southern right whale dolphin) for which incidental take 
authorization is proposed. Therefore we rely on the best available 
information on these species to make determinations as to whether the 
proposed authorized take numbers represent small numbers of the total 
populations of these species.
    The Burmeister's porpoise is distributed from the Atlantic Ocean in 
southern Brazil to the Pacific Ocean in northern Peru (Reyes 2009). 
While there are no quantitative data on abundance, the best available 
information suggest the species is assumed to be numerous throughout 
South American coastal waters (Brownell Jr. and Clapham 1999), with 
groups estimated at approximately 150 individuals observed off of Peru 
(Van Waerebeek et al. 2002). In addition the species is typically found 
shoreward of the 60 m isobath (Hammond et al. 2012), suggesting that 
the proposed number of authorized takes is likely conservative as the 
species is unlikely to be encountered throughout the full survey area. 
The species' wide distribution and apparent abundance suggest the 
proposed number of authorized takes would represent a small number of 
individuals relative to the species' total abundance.
    Peale's dolphin is a coastal species that is known to inhabit 
waters very near to shore, commonly within or shoreward of kelp beds, 
while in the waters of southern Chile and Tierra del Fuego they appear 
to prefer channels, fjords and deep bays (Goodall 2009). Their apparent 
habitat preference for waters very near to shore suggests that the 
number of proposed authorized takes is likely very conservative as the 
species is unlikely to be encountered throughout much of the survey 
area. While no abundance estimate exists for the species, Peale's 
dolphin is reportedly the most common cetacean found around the coast 
of the Falkland Islands and Chile (Brownell Jr. et al. 1999). The 
combination of the species' apparent abundance and the species' 
apparent preference for habitats that would not be surveyed by Lamont-
Doherty suggests the proposed number of authorized takes would 
represent a small number of individuals relative to the species' total 
abundance.
    The full distribution of the southern right whale dolphin is not 
known, but the species appears to be circumpolar and fairly common 
throughout its range. Survey data and stranding and fishery interaction 
data in northern Chile suggest that the species may be one of the most 
common cetaceans in the region (Van Waerebeek et al. 1991). The 
species' apparent abundance and its broad distribution suggest the 
proposed number of authorized takes would represent a small number of 
individuals relative to the species' total abundance.
    The pygmy right whale has a circumpolar distribution, between about 
30[deg] and 55[deg] S., with records from southern South America as 
well as Africa, Australia and New Zealand (Kemper 2009). There are no 
estimates of abundance for the species, but judging by the number of 
strandings in Australia and New Zealand, it is likely to be reasonably 
common in that region (Kemper 2009), with aggregations of up to 
approximately 80 individuals reported (Matsuoka 1996). The species' 
apparent abundance and its broad distribution suggest the proposed 
number of authorized takes would represent a small number of 
individuals relative to the species' total abundance.
    NMFS finds that the proposed incidental take described in Table 8 
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.

[[Page 23151]]

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 Southeast Pacific Ocean, 2016/2017. 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 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 Southeast Pacific 
Ocean, 2016/2017. 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 Southeast Pacific Ocean, between June 2016 and June 2017, 
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 Southeast Pacific Ocean 
between June 2016 and June 2017.

1. Effective Dates

    This Authorization is valid between June 2016 and June 2017.

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 Southeast Pacific Ocean, located approximately within the 
exclusive economic zone of Chile, between 18[deg] and 44[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 species in the area described in 
Tables 5-8 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(a) 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(a) 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 (7x50 Fujinon), and big-eye binoculars (25x150).

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

[[Page 23152]]

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, 
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

[[Page 23153]]

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 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 and accounting for 
animals at the surface but not detected [i.e., g(0) values] and for 
animals present but underwater and not available for sighting [i.e., 
f(0) values]) 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

[[Page 23154]]

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. 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: April 12, 2016.
Donna Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2016-09008 Filed 4-18-16; 8:45 am]
 BILLING CODE 3510-22-P