[Federal Register Volume 79, Number 120 (Monday, June 23, 2014)]
[Notices]
[Pages 35642-35676]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-14426]



[[Page 35641]]

Vol. 79

Monday,

No. 120

June 23, 2014

Part II





Department of Commerce





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National Oceanic and Atmospheric Administration





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Takes of Marine Mammals Incidental to Specified Activities; Taking 
Marine Mammals Incidental to a Marine Geophysical Survey in the 
Atlantic Ocean off the Eastern Seaboard, August to September 2014 and 
April to August 2015; Notice

  Federal Register / Vol. 79 , No. 120 / Monday, June 23, 2014 / 
Notices  

[[Page 35642]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XD214


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to a Marine Geophysical Survey in the 
Atlantic Ocean off the Eastern Seaboard, August to September 2014 and 
April to August 2015

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

ACTION: Notice; proposed Incidental Harassment Authorization; request 
for comments.

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SUMMARY: NMFS has received an application from the United States (U.S.) 
Geological Survey (USGS), Lamont-Doherty Earth Observatory of Columbia 
University (L-DEO), and National Science Foundation (NSF) for an 
Incidental Harassment Authorization (IHA) to take marine mammals, by 
harassment, incidental to conducting a marine geophysical (seismic) 
survey in the Atlantic Ocean off the Eastern Seaboard, August to 
September 2014 and April to August 2015. Pursuant to the Marine Mammal 
Protection Act (MMPA), NMFS is requesting comments on its proposal to 
issue an IHA to USGS to incidentally harass, by Level B harassment 
only, 34 species of marine mammals during the specified activity.

DATES: Comments and information must be received no later than July 23, 
2014.

ADDRESSES: Comments on the application should be addressed to Jolie 
Harrison, Supervisor, 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 noaa.gov">ITP.Goldstein@noaa.gov. Please include 0648-XD214 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 comments received are a part of the public record 
and will generally be posted to http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications without change. All Personal Identifying 
Information (for example, name, address, etc.) voluntarily submitted by 
the commenter may be publicly accessible. Do not submit Confidential 
Business Information or otherwise sensitive or protected information.
    An electronic copy of the application may be obtained by writing to 
the address specified above, telephoning the contact listed below (see 
FOR FURTHER INFORMATION CONTACT) or visiting the Internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. The following 
associated documents are also available at the same internet address: 
``Draft Environmental Assessment for Seismic Reflection Scientific 
Research Surveys during 2014 and 2015 in Support of Mapping the U.S. 
Atlantic Seaboard Extended Continental Margin and Investigating Tsunami 
Hazards.'' Documents cited in this notice may also be viewed, by 
appointment, during regular business hours, at the aforementioned 
address.
    The USGS, which is funding the proposed seismic survey, included 
with its application a ``Draft Environmental Assessment for Seismic 
Reflection Scientific Research Surveys during 2014 and 2015 in Support 
of Mapping the U.S. Atlantic Seaboard Extended Continental Margin and 
Investigating Tsunami Hazards,'' prepared by RPS Evan-Hamilton, Inc. in 
association with YOLO Environmental, Inc., GeoSpatial Strategy Group, 
and Ecology and Environment, Inc., on behalf of USGS, which is also 
available at the same internet address. Documents cited in this notice 
may be viewed, by appointment, during regular business hours, at the 
aforementioned address.

FOR FURTHER INFORMATION CONTACT: Howard Goldstein or Jolie Harrison, 
Office of Protected Resources, NMFS, 301-427-8401.

SUPPLEMENTARY INFORMATION:

Background

    Section 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.), 
directs the Secretary of Commerce (Secretary) to allow, upon request, 
the incidental, but not intentional, taking of small numbers of marine 
mammals, by United States citizens who engage in a specified activity 
(other than commercial fishing) within a specified geographical region 
if certain findings are made and either regulations are issued or, if 
the taking is limited to harassment, a notice of a proposed 
authorization is provided to the public for review.
    An authorization for the incidental takings shall be granted 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), and if the permissible methods of taking requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103 
as ``. . . an impact resulting from the specified activity that cannot 
be reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.''
    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 March 27, 2014, NMFS received an application from the USGS, L-
DEO, and NSF (hereafter referred to as USGS) requesting that NMFS issue 
an IHA for the take, by Level B harassment only, of small numbers of 
marine mammals incidental to conducting a marine seismic survey within 
the Exclusive Economic Zone (EEZ) and on the high seas (i.e., 
International Waters) to map the U.S. Atlantic Eastern Seaboard 
Extended Continental Shelf (ECS) region and investigate tsunami hazards 
during August to September 2014 and April to August 2015. USGS plan to 
use one source vessel, the R/V Marcus G. Langseth (Langseth) and a 
seismic airgun array and a hydrophone streamer to collect seismic data 
as part of the proposed seismic survey in the Atlantic Ocean off the 
Eastern Seaboard. In addition to the proposed operation of the seismic 
airgun array and hydrophone streamer, USGS intends to operate a multi-
beam echosounder and a sub-bottom profiler continuously during the 
seismic operations in order to map the ocean floor. The multi-beam 
echosounder and sub-bottom profiler would not be operated during 
transits at the beginning and end of the seismic survey. NMFS 
determined that the IHA application was adequate and complete on May 
14, 2014.
    Acoustic stimuli (i.e., increased underwater sound) generated 
during the operation of the seismic airgun array are likely to result 
in the take of marine mammals. Take, by Level B harassment only, of 
individuals of 34 species of marine mammals is anticipated to result

[[Page 35643]]

from the proposed specified activity. Take is not expected to result 
from the use of the multi-beam echosounder or sub-bottom profiler, for 
reasons discussed in this notice; nor is take expected to result from 
collision with the source vessel because it is a single vessel moving 
at a relatively slow speed (4.5 knots [kts]; 8.5 kilometers per hour 
[km/hr]; 5.3 miles per hour [mph]) during seismic acquisition within 
the survey, for a relatively short period of time (approximately two 17 
to 18 day legs), and it is likely that any marine mammal would be able 
to avoid the vessel.

Description of the Proposed Specified Activity

Overview

    USGS plans to conduct a marine seismic survey within the EEZ and on 
the high seas to map the U.S. Atlantic Eastern Seaboard ECS region and 
investigate tsunami hazards during August to September 2014 and April 
to August 2015. USGS proposes to use one source vessel, the Langseth, 
and a 36-airgun array and one 8 kilometer (km) (4.3 nautical mile 
[nmi]) hydrophone streamer to conduct the conventional seismic survey. 
In addition to the operations of airguns, the USGS intends to operate a 
multi-beam echosounder and a sub-bottom profiler on the Langseth during 
the proposed seismic survey to map the ocean floor.

Dates and Duration

    The Langseth would depart from Newark, New Jersey on August 15, 
2014. The seismic survey is expected to take approximately 16 days to 
complete. Approximately one day transit would be required at the 
beginning and end of the program. When the 2014 survey is completed, 
the Langseth would then transit to Norfolk, Virginia. The survey 
schedule is inclusive of weather and other contingency (e.g., equipment 
failure) time. The proposed activities for 2015 would be virtually 
identical to the proposed activities for 2014 as geographic area, 
duration, and trackline coverage are similar. The exact dates for the 
proposed activities in 2015 are uncertain, but are scheduled to occur 
within the April to August timeframe. The exact dates of the proposed 
activities depend on logistics and weather conditions.

Specified Geographic Region

    The proposed survey would be bounded by the following geographic 
coordinates:
    40.5694[deg] North, -66.5324[deg] West;
    38.5808[deg] North, -61.7105[deg] West;
    29.2456[deg] North, -72.6766[deg] West;
    33.1752[deg] North, -75.8697[deg] West;
    39.1583[deg] North, -72.8697[deg] West;
    The proposed activities for 2014 would generally occur towards the 
periphery of the proposed study area (see Figures 1 and 2 of the IHA 
application). The proposed activities for 2015 would survey more of the 
central portions of the study area. The tracklines proposed for both 
2014 and 2015 would be in International Waters (approximately 80% in 
2014 and 90% in 2015) and in the U.S. EEZ. Water depths range from 
approximately 1,450 to 5,400 meters (m) (4,593.2 to 17,716.5 feet [ft]) 
(see Figure 1 and 2 of the IHA application); no survey lines would 
extend to water depths less than 1,000 m.

Detailed Description of the Proposed Specified Activity

    USGS, Coastal and Marine Geology Program, (Primary Investigator 
[PI], Dr. Deborah Hutchinson) proposes to conduct a regional high-
energy, two-dimensional (2D) seismic survey in the northwest Atlantic 
Ocean within the U.S. EEZ and extending into International Waters as 
far as 648.2 km (350 nmi) from the U.S. coast (see Figure 1 of the IHA 
application). Water depths in the survey area range from approximately 
1,400 to greater than 5,400 meters (m) (4,593.2 to 17,716.5 feet [ft]). 
The proposed seismic survey would be scheduled to occur in two phases; 
the first phase during August to September 2014 (for approximately 17 
to 18 days), and the second phase between April and August 2015 (for 
approximately 17 to 18 days, specific dates to be determined). The 
proposed activities for both Phase 1 and Phase 2 are included in this 
IHA application (see Figure 2 of the IHA application). Some minor 
deviation from these dates is possible, depending on logistics and 
weather.
    USGS proposes to use conventional seismic methodology to: (1) 
Identify the outer limits of the U.S. continental shelf, also referred 
to as the ECS as defined by Article 76 of the Convention of the Law of 
the Sea; and (2) study the sudden mass transport of sediments down the 
continental shelf as submarine landslides that may pose significant 
tsunamigenic (i.e., tsunami-related) hazards to the Atlantic and 
Caribbean coastal communities.
    The proposed survey would involve one source vessel, the Langseth. 
The Langseth would deploy an array of 36 airguns as an energy source 
with a total volume of approximately 6,600 in\3\. The receiving system 
would consist of one 8,000 m (26,246.7 ft) hydrophone streamer. As the 
airgun array is towed along the survey lines, the hydrophone streamer 
would receive the returning acoustic signals from the towed airgun 
array and transfer the data to the on-board processing system. The data 
would be processed on-board the Langseth as the survey occurs.
    Each proposed leg of the survey (2014 and 2015) would be 17 to 18 
days in duration (exclusive of transit and equipment deployment and 
recovery) and would comprise of approximately 3,165 km (1,709 nmi) of 
tracklines of 2D seismic reflection coverage. The airgun array would 
operate continuously during the proposed survey (except for equipment 
testing, repairs, implemented mitigation measures, etc.). Data would 
continue to be acquired between line changes, as the successive track 
segments can be surveyed as almost one continuous line. Line turns of 
90 and no greater than 120 degrees would be required to move from one 
line segment to the next. The 2014 proposed survey design consists 
primarily of the tracklines that run along the periphery of the overall 
study area, including several internal tracklines (see Figure 2 of the 
IHA application). The 2015 proposed survey design consists of 
additional dip and tie lines (i.e., dip lines are lines that are 
perpendicular to the north-south trend of the continental margin; 
strike lines are parallel to the margin; and tie lines are any line 
that connects other lines). The 2015 proposed survey design may be 
modified based on the 2014 results.
    In addition to the operations of the airgun array, a Kongsberg EM 
122 multi-beam echosounder and a Knudsen Model 3260 Chirp sub-bottom 
profiler would also be operated from the Langseth continuously during 
airgun operations throughout the survey to map the ocean floor. The 
multi-beam and sub-bottom profiler would not operate during transits at 
the beginning and end of the survey. All planned geophysical data 
acquisition activities would be conducted by USGS with on-board 
assistance by the scientists who have proposed the study. The vessel 
would be self-contained, and the crew would live aboard the vessel for 
the entire cruise.

Vessel Specifications

    The Langseth, a seismic research vessel owned by the National 
Science Foundation (NSF) and operated by the Lamont-Doherty Earth 
Observatory of Columbia University (L-DEO), would tow the 36 airgun 
array, as well as the hydrophone streamer(s), along predetermined lines 
(see Figure 2 of the IHA application). When the Langseth is

[[Page 35644]]

towing the airgun array and the hydrophone streamer(s), the turning 
rate of the vessel is limited to three degrees per minute (2.5 km [1.5 
mi]). Thus, the maneuverability of the vessel is limited during 
operations with the streamer. The vessel would ``fly'' the appropriate 
U.S. Coast Guard-approved day shapes (mast head signals used to 
communicate with other vessels) and display the appropriate lighting to 
designate the vessel has limited maneuverability.
    The vessel has a length of 71.5 m (235 ft); a beam of 17.0 m (56 
ft); a maximum draft of 5.9 m (19 ft); and a gross tonnage of 3,834. 
The Langseth was designed as a seismic research vessel with a 
propulsion system designed to be as quiet as possible to avoid 
interference with the seismic signals emanating from the airgun array. 
The ship is powered by two 3,550 horsepower (hp) Bergen BRG-6 diesel 
engines which drive two propellers directly. 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 not used during 
seismic acquisition. The Langseth's operation speed during seismic data 
acquisition is typically 7.4 to 9.3 km per hour (hr) (km/hr) (4 to 5 
knots [kts]). When not towing seismic survey gear, the Langseth 
typically cruises at 18.5 to 24 km/hr (10 to 12 kts). The Langseth has 
a range of 25,000 km (13,499 nmi) (the distance the vessel can travel 
without refueling).
    The vessel also has an observation tower from which Protected 
Species Visual Observers (PSVO) would watch for marine mammals before 
and during the proposed airgun operations. When stationed on the 
observation platform, the PSVO's eye level would be approximately 21.5 
m (71 ft) above sea level providing the PSVO an unobstructed view 
around the entire vessel. More details of the Langseth can be found in 
the IHA application and the ``Final Programmatic Environmental Impact 
Statement/Overseas Environmental Impact Statement for Marine Seismic 
Research funded by the National Science Foundation or Conducted by the 
U.S. Geological Survey'' (2011) and the Record of Decision (2012) (NSF/
USGS PEIS).

Acoustic Source Specifications

Seismic Airguns
    The Langseth would deploy a 36-airgun array, consisting of two 18 
airgun (plus 2 spares) sub-arrays. Each sub-array would have a volume 
of approximately 3,300 cubic inches (in\3\) for a total volume of 6,600 
in\3\ for the 36-airgun array. The airgun array would consist of a 
mixture of Bolt 1500LL and Bolt 1900LLX airguns ranging in size from 40 
to 360 in\3\, with a firing pressure of 1,900 pounds per square inch 
(psi). The 18 airgun sub-arrays would be configured as two identical 
linear arrays or ``strings'' (see Figure 2.11 of the NSF/USGS PEIS). 
Each string would have 10 airguns, with the first and last airguns in 
the strings spaced 16 m (52.5 ft) apart. Of the 10 airguns, nine 
airguns in each string would be fired simultaneously (1,650 in\3\), 
whereas the tenth would be kept in reserve as a spare, to be turned on 
in case of failure of another airgun. The sub-arrays would be fired 
simultaneously during the survey. The two airgun sub-arrays would be 
distributed across an area of approximately 12 x 16 m (40 x 52.5 ft) 
behind the Langseth and would be towed approximately 140 m (459.3 ft) 
behind the vessel. Discharge intervals depend on both the ship's speed. 
The shot interval would be 50 m (164 ft) during the study. The shot 
interval would be approximately 20 to 24 seconds (s) based on an 
assumed boat speed of 4.5 knots. During firing, a brief (approximately 
0.1 s) pulse sound is emitted; the airguns would be silent during the 
intervening periods. The dominant frequency components range from 2 to 
188 Hertz (Hz). The firing pressure of the airgun array is 2,000 pounds 
per square inch (psi).
    The tow depth of the airgun array would be 9 m (29.5 ft) during the 
surveys. Because the actual source is a distributed sound source (36 
airguns) rather than a single point source, the highest sound 
measurable at any location in the water would be less than the nominal 
source level. In addition, the effective source level for sound 
propagating in near-horizontal directions would be substantially lower 
than the nominal omni-directional source level applicable to downward 
propagation because of the directional nature of the sound from the 
airgun array (i.e., sound is directed downward).
Hydrophone Streamer
    Acoustic signals would be recorded using a system array of one 
hydrophone streamer, which would be towed behind the Langseth. The 
streamer is Thompson-Marconi SENTRY solid cable construction and is 
approximately 8 km long. Cable-leveling birds would be used to keep the 
streamer cable and hydrophone at a constant depth. Cable-leveling birds 
would be spaced every 300 m (984.3 ft) with extra redundancy at the 
head and tail sections.

Metrics Used in This Document

    This section includes a brief explanation of the sound measurements 
frequently used in the discussions of acoustic effects in this 
document. Sound pressure is the sound force per unit area, and is 
usually measured in micropascals ([mu]Pa), where 1 pascal (Pa) is the 
pressure resulting from a force of one newton exerted over an area of 
one square meter. Sound pressure level (SPL) is expressed as the ratio 
of a measured sound pressure and a reference level. The commonly used 
reference pressure level in underwater acoustics is 1 [mu]Pa, and the 
units for SPLs are dB re 1 [mu]Pa. SPL (in decibels [dB]) = 20 log 
(pressure/reference pressure).
    SPL is an instantaneous measurement and can be expressed as the 
peak, the peak-to-peak (p-p), or the root mean square (rms). Root mean 
square (rms), which is the square root of the arithmetic average of the 
squared instantaneous pressure values, is typically used in discussions 
of the effects of sounds on vertebrates and all references to SPL in 
this document refer to the root mean square unless otherwise noted.

Characteristics of the Airgun Pulses

    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 the amount of sound 
transmitted in the near horizontal directions is reduced. However, the 
airgun array also emits sounds that travel horizontally toward non-
target areas.
    The nominal source levels of the airgun arrays used by L-DEO on the 
Langseth are 236 to 265 dB re 1 [mu]Pa (p-p) and the rms value for a 
given airgun pulse is typically 16 dB re 1 [mu]Pa lower than the peak-
to-peak value (Greene, 1997; McCauley et al., 1998, 2000a). However, 
the difference between rms and peak or peak-to-peak values for a given 
pulse depends on the frequency content and duration of the pulse, among 
other factors.
    Accordingly, L-DEO has predicted the received sound levels in 
relation to distance and direction from the 36 airgun array and the 
single Bolt 1900LL 40 in\3\ airgun, which would be used during power-
downs. A detailed description of L-DEO modeling for this

[[Page 35645]]

survey's marine seismic source arrays for protected species mitigation 
is provided in the NSF/USGS PEIS (see Appendix H). NMFS refers the 
reviewers to the IHA application and NSF/USGS PEIS documents for 
additional information.

Predicted Sound Levels for the Airguns

    Tolstoy et al. (2009) and Diebold et al. (2010) reported results 
for propagation measurements of pulses from the Langseth's 36 airgun, 
6,600 in\3\ array in shallow water (approximately 50 m [164 ft]), 
intermediate water (a slope site), and deep water depths (approximately 
1,600 m [5,249 ft]) in the Gulf of Mexico in 2007 and 2008. Results of 
the Gulf of Mexico calibration study (Tolstoy et al., 2009; Diebold et 
al., 2010) showed that radii around the airguns for various received 
levels varied with water depth and that sound propagation varied with 
array tow depth.
    The L-DEO used the results from the Gulf of Mexico study to 
determine the algorithm for its model that calculates the mitigation 
exclusion zones for the 36-airgun array and the single airgun. L-DEO 
has used these calculated values to determine buffer (i.e., 160 dB) and 
exclusion zones for the 36 airgun array and previously modeled 
measurements by L-DEO for the single airgun, to designate exclusion 
zones for purposes of mitigation, and to estimate take for marine 
mammals in the northwest Atlantic Ocean. A detailed description of the 
modeling effort is provided in the NSF/USGS PEIS.
    Comparison of the Tolstoy et al. (2009) calibration study with the 
L-DEO's model for the Langseth's 36-airgun array indicates that the 
model represents the actual received levels, within the first few 
kilometers and the locations of the predicted exclusion zones. However, 
the model for deep water (greater than 1,000 m; 3,280 ft) overestimated 
the received sound levels at a given distance but is still valid for 
defining exclusion zones at various tow depths. Because the tow depth 
of the array in the calibration study is less shallow (6 m [19.7 ft]) 
than the tow depths in the proposed survey (9 m [29.5 ft]), L-DEO used 
the following correction factors for estimating the received levels 
during the proposed surveys (see Table 1). The correction factors are 
the ratios of the 160, 180, and 190 dB distances from the modeled 
results for the 6,600 in\3\ airgun arrays towed at 6 m (19.7 ft) versus 
9, 12, or 15 m (29.5, 39.4, or 49.2 ft) (LGL, 2008). For a single 
airgun, the tow depth has minimal effect on the maximum near-field 
output and the shape of the frequency spectrum for the single airgun; 
thus, the predicted exclusion zones are essentially the same at 
different tow depths. The L-DEO's model does not allow for bottom 
interactions, and thus is most directly applicable to deep water.
    Using the model (airgun array and single airgun), Table 1 (below) 
shows the distances at which three rms sound levels are expected to be 
received from the 36 airgun array and a single airgun. To avoid the 
potential for injury or permanent physiological damage (Level A 
harassment), NMFS's (1995, 2000) current practice is that cetaceans and 
pinnipeds should not be exposed to pulsed underwater noise at received 
levels exceeding 180 dB re 1 [mu]Pa and 190 dB re 1 [mu]Pa, 
respectively. L-DEO used these levels to establish the proposed 
exclusion zones. If marine mammals are detected within or about to 
enter the appropriate exclusion zone, the airguns would be powered-down 
(or shut-down, if necessary) immediately. NMFS also assumes that marine 
mammals exposed to levels exceeding 160 dB re 1 [mu]Pa may experience 
Level B harassment. Table 1 summarizes the predicted distances at which 
sound levels (160, 180, and 190 dB [rms]) are expected to be received 
from the 36 airgun array and a single airgun operating in deep water 
depths.

  Table 1--Measured (Array) or Predicted (Single Airgun) Distances to Which Sound Levels >=190, 180, and 160 dB re 1 [mu]Pa (rms) Could Be Received in
  Deep Water During the Proposed Seismic Survey in the Northwest Atlantic Ocean Off the Eastern Seaboard, August to September 2014 and April to August
                                                                          2015
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                 Predicted RMS radii distances (m)
                                                             Water depth  ------------------------------------------------------------------------------
         Sound source and volume           Tow depth  (m)        (m)                                                                                 160
                                                                                      190 dB                               180 dB                     dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
Single Bolt airgun (40 in\3\)............               9          >1,000  13 m (42.7 ft) *100 m would   100 m (328.1 ft)..........................  388
                                                                            be used for pinnipeds as                                                  m
                                                                            well as cetaceans.                                                       (1,
                                                                                                                                                     273
                                                                                                                                                     ft)
                                                                                                                                                      .
36 airguns (6,600 in\3\).................               9          >1,000  286 m (938.3 ft)............  927 m (3,041.3 ft)........................  5,7
                                                                                                                                                     80
                                                                                                                                                      m
                                                                                                                                                     (18
                                                                                                                                                     ,96
                                                                                                                                                     3.3
                                                                                                                                                     ft)
                                                                                                                                                      .
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Along with the airgun operations, two additional acoustical data 
acquisition systems would be operated from the Langseth continuously 
during seismic operations during the survey. The ocean floor would be 
mapped with the Kongsberg EM 122 multi-beam echosounder and a Knudsen 
320B sub-bottom profiler. These sound sources would be operated 
continuously from the Langseth throughout the cruise, except for during 
transits at the beginning and end of the proposed survey.

Multi-Beam Echosounder

    The Langseth would operate a Kongsberg EM 122 multi-beam 
echosounder concurrently during airgun operations to map 
characteristics of the ocean floor. The hull-mounted multi-beam 
echosounder emits brief pulses of sound (also called a ping) (10.5 to 
13, usually 12 kHz) in a fan-shaped beam that extends downward and to 
the sides of the ship. The transmitting beamwidth is 1[deg] 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) or four 
(less than 1,000 m) successive, fan-shaped transmissions, each 
ensonifying a sector that extends 1[deg] fore-aft. Continuous-wave 
pulses increase from 2 to 15 milliseconds (ms) long in water depths up 
to 2,600 m (8,350.2 ft), and frequency modulated (FM) chirp pulses up 
to 100 ms long are used in water greater than 2,600 m. The successive 
transmissions span an overall cross-track angular extent of about 
150[deg], with 2 ms gaps between the pulses for successive sectors (see 
Table 1 of the IHA application).

Sub-Bottom Profiler

    The Langseth would also operate a Knudsen Chirp 3260 sub-bottom 
profiler

[[Page 35646]]

continuously throughout the cruise simultaneously with the multi-beam 
echosounder to map and provide information about the sedimentary 
features and bottom topography. The beam is transmitted as a 27[deg] 
cone, which is directed downward by a 3.5 kHz transducer in the hull of 
the Langseth. The nominal power output is 10 kilowatts (kW), but the 
actual maximum radiated power is 3 kW or 222 dB re 1 [micro]Pam. The 
ping duration is up to 64 milliseconds (ms). The ping interval is three 
to five seconds, depending on water depth. The sub-bottom profiler is 
capable of reaching water depths of 10,000 m (32,808.4 ft) and 
penetrating tens of meters into the sediments.
    Both the multi-beam echosounder and sub-bottom profiler are 
operated continuously during survey operations. The multi-beam 
echosounder and sub-bottom profiler would not operate during transits 
at the beginning and end of the proposed seismic survey. Actual 
operating parameters would be established at the time of the survey.
    NMFS expects that acoustic stimuli resulting from the proposed 
operation of the single airgun or the 36 airgun array has the potential 
to harass marine mammals. NMFS does not expect that the movement of the 
Langseth, during the conduct of the seismic survey, has the potential 
to harass marine mammals because of the relatively slow operation speed 
of the vessel (approximately 4.5 knots [kts]; 8.5 km/hr; 5.3 mph) 
during seismic acquisition.
Description of the Marine Mammals in the Area of the Proposed Specified 
Activity
    Forty-five species of marine mammal (37 cetaceans [whales, 
dolphins, and porpoises] including 30 odontocetes and 7 mysticetes, 7 
pinnipeds [seals and sea lions], and 1 sirenian [manatees]) are known 
to occur in the western North Atlantic Ocean study area (Read et al., 
2009; Waring et al., 2013). Of those 45 species of marine mammals, 34 
cetaceans and 4 pinnipeds could be found or are likely to occur in the 
proposed study area during the spring/summer/fall months. Several of 
these species are listed as endangered under the U.S. Endangered 
Species Act of 1973 (ESA; 16 U.S.C. 1531 et seq.), including the North 
Atlantic right (Eubalaena glacialis), humpback (Megaptera 
novaeangliae), sei (Balaenoptera borealis), fin (Balaenoptera 
physalus), blue (Balaenoptera musculus), and sperm (Physeter 
macrocephalus) whales. Fourteen cetacean species, although present in 
the wider western North Atlantic Ocean, are considered rare and likely 
would not be found near the proposed study area. The harbor porpoise 
(Phocoena phocoena) does not occur in deep offshore waters. The four 
pinniped species (harbor [Phoca vitulina], harp [Phoca groenlandica], 
gray [Halichoerus grypus], and hooded [Cystophora cristata] seals) are 
also considered coastal species (any sightings would be considered 
extralimital) and are not known to occur in the deep waters of the 
proposed survey area. No pinnipeds are expected to be present in the 
proposed study area. The West Indian manatee (Trichechus manatus 
latirostris) is listed as endangered under the ESA and is managed by 
the U.S. Fish and Wildlife Service and is not considered further in 
this proposed IHA notice.
    General information on the taxonomy, ecology, distribution, 
seasonality and movements, and acoustic capabilities of marine mammals 
are given in sections 3.6.1, 3.7.1, and 3.8.1 of the NSF/USGS PEIS. The 
general distribution of mysticetes, odontocetes, and pinnipeds in the 
North Atlantic Ocean is discussed in sections 3.6.3.4, 3.7.3.4, and 
3.8.3.4 of the NSF/USGS PEIS, respectively. In addition, Section 3.1 of 
the ``Atlantic OCS Proposed Geological and Geophysical Activities Mid-
Atlantic and South Atlantic Planning Areas Draft Programmatic 
Environmental Impact Statement'' (Bureau of Ocean Energy Management, 
2012) reviews similar information for all marine mammals that may occur 
within the proposed study area.
    Various systematic surveys have been conducted throughout the 
western North Atlantic Ocean, including within sections of the proposed 
study area. Records from the Ocean Biogeographic Information System 
(OBIS) database hosted by Rutgers University and Duke University (Read 
et al., 2009) were used as the main source of information. The database 
includes survey data collected during the Cetaceans and Turtle 
Assessment Program (CeTAP) conducted between 1978 and 1982 that 
consists of both aerial and vessel-based surveys between Cape Hatteras, 
North Carolina, and the Gulf of Maine. The database also includes 
survey data collected during the NMFS Northeast Fisheries Science 
Center and Southeast Fisheries Science Center stock assessment surveys 
conducted in 2004 (surveys between Nova Scotia, Canada, and Florida).
    No known current regional or stock abundance estimates are 
available in the proposed study area of the northwest Atlantic Ocean 
for the Bryde's whale (Balaenoptera edeni), Fraser's (Lagenodelphis 
hosei), spinner (Stenella longirostris), and Clymene dolphin (Stenella 
clymene), and melon-headed (Peponocephala electra), pygmy killer 
(Feresa attenuata), false killer (Pseudorca crassidens), and killer 
whales (Orcinus orca). Although NMFS does not have current regional 
population or stock abundance estimates for these species in the 
northwest Atlantic Ocean, abundance estimates from other areas such as 
the northern Gulf of Mexico stock, regional ocean basins (e.g., eastern 
tropical Pacific Ocean), or global summation are available. These 
abundance estimates are considered the best available information.
    Bryde's whales are distributed worldwide in tropical and sub-
tropical waters. In the western North Atlantic Ocean, Bryde's whales 
are reported from off the southeastern U.S. and the southern West 
Indies to Cabo Frio, Brazil (Leatherwood and Reeves, 1983). No stock of 
Bryde's whales has been identified in U.S. waters of the Atlantic 
coast. The northern Gulf of Mexico population is considered a separate 
stock and has a best abundance estimate of 33 animals. It has been 
postulated that the Bryde's whales found in the northern Gulf of Mexico 
may represent a resident stock (Schmidly, 1981; Leatherwood and Reeves, 
1983).
    Fraser's dolphins are distributed worldwide in tropical waters and 
are assumed to be part of the cetacean fauna of the tropical western 
North Atlantic (Perrin et al., 1994). There are no abundance estimates 
for either the western North Atlantic or the northern Gulf of Mexico 
stocks. The western North Atlantic population is provisionally being 
considered a separate stock for management purposes, although there is 
currently no information to differentiate this stock from the northern 
Gulf of Mexico stock. The numbers of Fraser's dolphins off the U.S. or 
Canadian Atlantic coast are unknown, and seasonal abundance estimates 
are not available for this stock, since it was rarely seen in any 
surveys. The population size for Fraser's dolphins is unknown; however, 
about 289,000 animals occur in the eastern tropical Pacific Ocean 
(Jefferson et al., 2008).
    Spinner dolphins are distributed in oceanic and coastal tropical 
waters (Leatherwood et al., 1976). This is presumably an offshore, 
deep-water species, and its distribution in the Atlantic is poorly 
known (Schmidly, 1981; Perrin and Gilpatrick, 1994). The western North 
Atlantic population of spinner dolphins is provisionally being 
considered a separate stock for

[[Page 35647]]

management purposes, although there is currently no information to 
differentiate this stock from the northern Gulf of Mexico stock. The 
numbers of spinner dolphins off the U.S. or Canadian Atlantic coast are 
unknown, and seasonal abundance estimates are not available for this 
stock since it was rarely seen in any of the surveys. The best 
abundance estimate available for the northern Gulf of Mexico spinner 
dolphins is 11,441 animals.
    The Clymene dolphin is endemic to tropical and sub-tropical waters 
of the Atlantic (Jefferson and Curry, 2003). The western North Atlantic 
population of Clymene dolphins is provisionally considered a separate 
stock for management purposes, although there is currently no 
information to differentiate this stock from the northern Gulf of 
Mexico stock. The numbers of Clymene dolphins off the U.S. or Canadian 
Atlantic coast are unknown, and seasonal abundance estimates are not 
available for this species since it was rarely seen in any surveys. The 
best abundance estimate for the Clymene dolphin in the western North 
Atlantic was 6,086 in 2003 and represents the first and only estimate 
to date for this species in the U.S. Atlantic EEZ; however this 
estimate is older than eight years and is deemed unreliable (Wade and 
Angliss, 1997; Mullin and Fulling, 2003).
    The melon-headed whale is distributed worldwide in tropical to sub-
tropical waters (Jefferson et al., 1994). The western North Atlantic 
population is provisionally being considered a separate stock from the 
northern Gulf of Mexico stock. The numbers of melon-headed whales off 
the U.S. or Canadian Atlantic coast are unknown, and seasonal abundance 
estimates are not available for this stock, since it was rarely seen in 
any surveys. The best abundance estimate available for northern Gulf of 
Mexico melon-headed whales is 2,235 animals.
    The pygmy killer whale is distributed worldwide in tropical to sub-
tropical waters and is assumed to be part of the cetacean fauna of the 
tropical western North Atlantic (Jefferson et al., 1994). The western 
North Atlantic population of pygmy killer whales is provisionally being 
considered one stock for management purposes. The numbers of pygmy 
killer whales off the U.S. or Canadian Atlantic coast are unknown, and 
seasonal abundance estimates are not available for this stock, since it 
was rarely seen in any surveys. The best abundance estimate available 
for the northern Gulf of Mexico pygmy killer whale is 152 animals.
    The false killer whale is distributed worldwide throughout warm 
temperate and tropical oceans (Leatherwood and Reeves, 1983). No stock 
has been identified for false killer whales in U.S. waters off the 
Atlantic coast. The Gulf of Mexico population is provisionally being 
considered one stock for management purposes, although there is 
currently no information to differentiate this stock from the Atlantic 
Ocean stock. The current population size for the false killer whale in 
the northern Gulf of Mexico is unknown because the survey data is more 
than 8 years old; however, the most recent abundance estimate pooled 
from 2003 to 2004 was 777 animals (Wade and Angliss, 1997; Mullin, 
2007).
    Killer whales are characterized as uncommon or rare in waters of 
the U.S. Atlantic EEZ (Katona et al., 1988). Their distribution, 
however, extends from the Arctic ice-edge to the West Indies, often in 
offshore and mid-ocean areas. The size of the western North Atlantic 
stock population off the eastern U.S. coast is unknown. No information 
on stock differentiation for the Atlantic Ocean population exists, 
although an analysis of vocalizations of killer whales from Iceland and 
Norway indicated that whales from these areas may represent different 
stocks (Moore et al., 1988). The northern Gulf of Mexico population is 
provisionally being considered a separate stock for management 
purposes, although there is currently no information to differentiate 
this stock from the Atlantic Ocean stock. The best abundance estimate 
available for northern Gulf of Mexico killer whales is 28 animals. 
There are estimated to be at least approximately 92,500 killer whales 
worldwide (i.e., 80,000 south of Antarctic Convergence, 445 in Norway, 
8,500 in eastern tropical Pacific Ocean, 1,500 in North America coastal 
waters, and 2,000 in Japanese waters) (Jefferson et al., 2008).Table 2 
(below) presents information on the abundance, distribution, population 
status, and conservation status of the species of marine mammals that 
may occur in the proposed study area during August to September 2014 
and April to August 2015.

 Table 2--The Habitat, Occurrence, Range, Abundance, and Conservation Status of Marine Mammals That May Occur in
        or Near the Proposed Seismic Survey Area in the Northwest Atlantic Ocean Off the Eastern Seaboard
                      [See text and Table 3 in USGS's IHA application for further details]
----------------------------------------------------------------------------------------------------------------
                                                                                    Population
                                                                                 estimate in the
           Species                 Habitat        Occurrence        Range in      North Atlantic    ESA    MMPA
                                                                 Atlantic Ocean   region/stock/     \1\     \2\
                                                                                    other \3\
----------------------------------------------------------------------------------------------------------------
Mysticetes:
    North Atlantic right       Pelagic, shelf   Regular.......  Canada to        455/455          EN      D
     whale (Eubalaena           and coastal.                     Florida.         (Western
     glacialis).                                                                  Atlantic
                                                                                  stock).
    Humpback whale (Megaptera  Mainly           Regular.......  Canada to        11,600 \4\/823   EN      D
     novaeangliae).             nearshore,                       Caribbean.       (Gulf of Maine
                                banks.                                            stock).
    Minke whale (Balaenoptera  Pelagic and      Regular.......  Arctic to        138,000 \5\/     NL      NC
     acutorostrata).            coastal.                         Caribbean.       20,741
                                                                                  (Canadian East
                                                                                  Coast stock).
    Bryde's whale              Coastal,         Rare..........  40[deg] North    NA/NA/33         NL      NC
     (Balaenoptera edeni).      offshore.                        to 40[deg]       (Northern Gulf
                                                                 South.           of Mexico
                                                                                  stock)/20,000
                                                                                  to 30,000 \16\
                                                                                  (North Pacific
                                                                                  Ocean).
    Sei whale (Balaenoptera    Primarily        Rare..........  Canada to New    10,300 \6\/357   EN      D
     borealis).                 offshore,                        Jersey.          (Nova Scotia
                                pelagic.                                          stock).

[[Page 35648]]

 
    Fin whale (Balaenoptera    Continental      Regular.......  Canada to North  26,500 \7\/      EN      D
     physalus).                 slope, pelagic.                  Carolina.        3,522 (Western
                                                                                  North Atlantic
                                                                                  stock).
    Blue whale (Balaenoptera   Pelagic, shelf,  Rare..........  Arctic to        855 \8\/440      EN      D
     musculus).                 coastal.                         Florida.         (Western North
                                                                                  Atlantic
                                                                                  stock).
Odontocetes:
    Sperm whale (Physeter      Pelagic, slope,  Regular.......  Canada to        13,190 \9\/      EN      D
     macrocephalus).            canyons, deep                    Caribbean.       2,288 (North
                                sea.                                              Atlantic
                                                                                  stocks).
    Pygmy sperm whale (Kogia   Deep waters off  Rare..........  Massachusetts    NA/3,785         NL      NC
     breviceps).                shelf.                           to Florida.      (Western North
                                                                                  Atlantic
                                                                                  stock).
    Dwarf sperm whale (Kogia   Deep waters off  Rare..........  Massachusetts    ...............  NL      NC
     sima).                     shelf.                           to Florida.
    Cuvier's beaked whale      Pelagic, slope,  Rare..........  Canada to        NA/6,532         NL      NC
     (Ziphius cavirostris).     canyons.                         Caribbean.       (Western North
                                                                                  Atlantic
                                                                                  stock).
    Northern bottlenose whale  Pelagic........  Rare..........  Arctic to New    40,000 \10\/NA   NL      NC
     (Hyperoodon ampullatus).                                    Jersey.          (Western North
                                                                                  Atlantic
                                                                                  stock).
    True's beaked whale        Pelagic, slope,  Rare..........  Canada to        NA/7,092         NL      NC
     (Mesoplodon mirus).        canyons.                         Bahamas.         (Western North
                                                                                  Atlantic
                                                                                  stock).
    Gervais' beaked whale      Pelagic, slope,  Rare..........  Canada to        ...............  NL      NC
     (Mesoplodon europaeus).    canyons.                         Florida.
    Sowerby's beaked whale     Pelagic, slope,  Rare..........  Canada to        ...............  NL      NC
     (Mesoplodon bidens).       canyons.                         Florida.
    Blainville's beaked whale  Pelagic, slope,  Rare..........  Canada to        ...............  NL      NC
     (Mesoplodon                canyons.                         Florida.
     densirostris).
    Bottlenose dolphin         Coastal,         Regular.......  Canada to        NA/77,532        NL      NC
     (Tursiops truncatus).      oceanic, shelf                   Florida.         (Western North
                                break.                                            Atlantic
                                                                                  Offshore
                                                                                  stock).
    Atlantic white-sided       Shelf and slope  Regular.......  Greenland to     10,000 to        NL      NC
     dolphin (Lagenorhynchus                                     North Carolina.  100,000s \11\/
     acutus).                                                                     48,819
                                                                                  (Western North
                                                                                  Atlantic
                                                                                  stock).
    Fraser's dolphin           Shelf and slope  Rare..........  North Carolina   NA/NA (Western   NL      NC
     (Lagenodelphis hosei).                                      to Florida.      North Atlantic
                                                                                  stock)/289,000
                                                                                  \16\ (eastern
                                                                                  tropical
                                                                                  Pacific Ocean).
    Atlantic spotted dolphin   Shelf, offshore  Regular.......  Massachusetts    NA/44,715        NL      NC
     (Stenella frontalis).                                       to Caribbean.    (Western North
                                                                                  Atlantic
                                                                                  stock).
    Pantropical spotted        Coastal, shelf,  Regular.......  Massachusetts    NA/3,333         NL      NC
     dolphin (Stenella          slope.                           to Florida.      (Western North
     attenuata).                                                                  Atlantic
                                                                                  stock).
    Striped dolphin (Stenella  Off continental  Regular.......  Canada to        NA/54,807        NL      NC
     coeruleoalba).             shelf,                           Caribbean.       (Western North
                                convergence                                       Atlantic
                                zones,                                            stock).
                                upwelling.
    Spinner dolphin (Stenella  Mainly           Rare..........  Maine to         NA/NA (Western   NL      NC
     longirostris).             nearshore.                       Caribbean.       North Atlantic
                                                                                  stock)/11,441
                                                                                  (Northern Gulf
                                                                                  of Mexico
                                                                                  stock)/
                                                                                  1,250,000 \16\
                                                                                  (eastern
                                                                                  tropical
                                                                                  Pacific Ocean).
    Clymene dolphin (Stenella  Coastal, shelf,  Rare..........  North Carolina   NA/NA (Western   NL      NC
     clymene).                  slope.                           to Florida.      North Atlantic
                                                                                  stock--6,086
                                                                                  in 2003)/129
                                                                                  (Northern Gulf
                                                                                  of Mexico
                                                                                  stock).
    Short-beaked common        Shelf, pelagic,  Regular.......  Canada to        NA/173,486       NL      NC
     dolphin (Delphinus         seamounts.                       Georgia.         (Western North
     delphis).                                                                    Atlantic
                                                                                  stock).

[[Page 35649]]

 
    Rough-toothed dolphin      Pelagic........  Rare..........  New Jersey to    NA/271 (Western  NL      NC
     (Steno bredanensis).                                        Florida.         North Atlantic
                                                                                  stock).
    Risso's dolphin (Grampus   Shelf, slope,    Regular.......  Canada to        NA/18,250        NL      NC
     griseus).                  seamounts.                       Florida.         (Western North
                                                                                  Atlantic
                                                                                  stock).
    Melon-headed whale         Deep waters off  Rare..........  North Carolina   NA/NA (Western   NL      NC
     (Peponocephala electra).   shelf.                           to Florida.      North Atlantic
                                                                                  stock)/2,235
                                                                                  (Northern Gulf
                                                                                  of Mexico
                                                                                  stock)/45,000
                                                                                  \16\ (eastern
                                                                                  tropical
                                                                                  Pacific Ocean).
    Pygmy killer whale         Pelagic........  Rare..........  NA.............  NA/NA (Western   NL      NC
     (Feresa attenuata).                                                          North Atlantic
                                                                                  stock)/152
                                                                                  (Northern Gulf
                                                                                  of Mexico
                                                                                  stock)/39,000
                                                                                  \16\ (eastern
                                                                                  tropical
                                                                                  Pacific Ocean).
    False killer whale         Pelagic........  Rare..........  NA.............  NA/NA/777 in     NL      NC
     (Pseudorca crassidens).                                                      2003-2004
                                                                                  (Northern Gulf
                                                                                  of Mexico
                                                                                  stock).
    Killer whale (Orcinus      Pelagic, shelf,  Rare..........  Arctic to        NA/NA (Western   NL      NC
     orca).                     coastal.                         Caribbean.       North Atlantic
                                                                                  stock)/28
                                                                                  (Northern Gulf
                                                                                  of Mexico
                                                                                  stock)/At
                                                                                  least ~92,500
                                                                                  \16\ Worldwide.
    Short-finned pilot whale   Mostly pelagic,  Regular.......  Massachusetts    780,000 \12\/    NL      NC
     (Globicephala              high relief.                     to Florida.      21,515 short-
     macrorhynchus).                                                              finned pilot
                                                                                  whale 26,535
                                                                                  long-finned
                                                                                  pilot whale
                                                                                  (Western North
                                                                                  Atlantic
                                                                                  stock).
    Long-finned pilot whale    Mostly pelagic.  Regular.......  Canada to South  NL.............  NC
     (Globicephala melas).                                       Carolina.
    Harbor porpoise (Phocoena  Shelf, coastal,  Rare..........  Canada to North  ~500,000 \13\/   NL      NC
     phocoena).                 pelagic.                         Carolina.        79,883 (Gulf
                                                                                  of Maine/Bay
                                                                                  of Fundy
                                                                                  stock).
Pinnipeds:
    Harbor seal (Phoca         Coastal........  Rare..........  Canada to North  NA/70,142        NL      NC
     vitulina concolor).                                         Carolina.        (Western North
                                                                                  Atlantic
                                                                                  stock).
    Gray seal (Halichoerus     Coastal,         Rare..........  Canada to North  NA/331,000       NL      NC
     grypus).                   pelagic.                         Carolina.        (Western North
                                                                                  Atlantic
                                                                                  stock).
    Harp seal (Phoca           Ice whelpers,    Rare..........  Canada to New    8.6 to 9.6       NL      NC
     groenlandica).             pelagic.                         Jersey.          million \14\/
                                                                                  7.1 million
                                                                                  (Western North
                                                                                  Atlantic
                                                                                  stock).
    Hooded seal (Cystophora    Ice whelpers,    Rare..........  Canada to        600,000/592,100  NL      NC
     cristata).                 pelagic.                         Caribbean.       (Western North
                                                                                  Atlantic
                                                                                  stock).
----------------------------------------------------------------------------------------------------------------
NA = Not available or not assessed.
\1\ U.S. Endangered Species Act: EN = Endangered, T = Threatened, DL = Delisted, NL = Not listed.
\2\ U.S. Marine Mammal Protection Act: D = Depleted, NC = Not Classified.
\3\ NMFS Marine Mammal Stock Assessment Reports.
\4\ Best estimate for western North Atlantic 1992 to 1993 (IWC, 2014).
\5\ Best estimate for North Atlantic 2002 to 2007 (IWC, 2014).
\6\ Estimate for the Northeast Atlantic in 1989 (Cattanach et al., 1993).
\7\ Best estimate for North Atlantic 2007 (IWC, 2014) .
\8\ Central and Northeast Atlantic 2001 (Pike et al., 2009).
\9\ North Atlantic (Whitehead, 2002).
\10\ Eastern North Atlantic (NAMMCO, 1995).
\11\ North Atlantic (Reeves et al., 1999).
\12\ Globicephala spp. combined, Central and Eastern North Atlantic (IWC, 2014).
\13\ North Atlantic (Jefferson et al., 2008).
\14\ Northwest Atlantic (DFO, 2012).
\15\ Northwest Atlantic (Andersen et al., 2009).
\16\ Jefferson et al. (2008).


[[Page 35650]]

    Further detailed information regarding the biology, distribution, 
seasonality, life history, and occurrence of these marine mammal 
species in the proposed project area can be found in sections 3 and 4 
of USGS's IHA application. NMFS has reviewed these data and determined 
them to be the best available scientific information for the purposes 
of the proposed IHA.

Potential Effects of the Specified Activity on Marine Mammals

    This section includes a summary and discussion of the ways that the 
types of stressors associated with the specified activity (e.g., 
seismic airgun operation, vessel movement, gear deployment) have been 
observed to impact marine mammals. This discussion may also include 
reactions that we consider to rise to the level of a take and those 
that we do not consider to rise to the level of take (for example, with 
acoustics), we may include a discussion of studies that showed animals 
not reacting at all to sound or exhibiting barely measureable 
avoidance). This section is intended as a background of potential 
effects and does not consider either the specific manner in which this 
activity would be carried out or the mitigation that would be 
implemented, and how either of those would shape the anticipated 
impacts from this specific activity. The ``Estimated Take by Incidental 
Harassment'' section later in this document will include a quantitative 
analysis of the number of individuals that are expected to be taken by 
this activity. The ``Negligible Impact Analysis'' section will include 
the analysis of how this specific 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.
    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. Based 
on available behavioral data, audiograms have been derived using 
auditory evoked potentials, anatomical modeling, and other data, 
Southall et al. (2007) designate ``functional hearing groups'' for 
marine mammals and estimate the lower and upper frequencies of 
functional hearing groups'' for marine mammals and estimate the lower 
and upper frequencies of functional hearing of the groups. The 
functional groups and the associated frequencies are indicated below 
(though animals are less sensitive to sounds at the outer edge of their 
functional range and most sensitive to sounds of frequencies within a 
smaller range somewhere in the middle of their functional hearing 
range):
     Low-frequency cetaceans (13 species of mysticetes): 
Functional hearing is estimated to occur between approximately 7 Hz and 
30 kHz;
     Mid-frequency cetaceans (32 species of dolphins, six 
species of larger toothed whales, and 19 species of beaked and 
bottlenose whales): Functional hearing is estimated to occur between 
approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (eight species of true porpoises, 
six species of river dolphins, Kogia spp., the franciscana [Pontoporia 
blainvillei], and four species of cephalorhynchids): Functional hearing 
is estimated to occur between approximately 200 Hz and 180 kHz; and
     Phocid pinnipeds in water: Functional hearing is estimated 
to occur between approximately 75 Hz and 100 kHz;
     Otariid pinnipeds in water: Functional hearing is 
estimated to occur between approximately 100 Hz and 40 kHz.
    As mentioned previously in this document, 38 marine mammal species 
(34 cetacean and 4 pinniped species) are likely to occur in the 
proposed seismic survey area. Of the 34 cetacean species likely to 
occur in USGS's proposed action area, 7 are classified as low-frequency 
cetaceans (i.e., North Atlantic right, humpback, minke, Bryde's, sei, 
fin, and blue whale), 24 are classified as mid-frequency cetaceans 
(i.e., sperm, Cuvier's, True's, Gervais', Sowerby's, Blainville's, 
Northern bottlenose, melon-headed, pygmy killer, false killer, killer, 
short-finned, and long-finned whale, bottlenose, Atlantic white-sided, 
Fraser's, Atlantic spotted, pantropical spotted, striped, spinner, 
Clymene, short-beaked common, rough-toothed, and Risso's dolphin), and 
3 are classified as high-frequency cetaceans (i.e., pygmy sperm and 
dwarf sperm whale and harbor porpoise) (Southall et al., 2007). A 
species' functional hearing group is a consideration when we analyze 
the effects of exposure to sound on marine mammals.
    Acoustic stimuli generated by the operation of the airguns, which 
introduce sound into the marine environment, may have the potential to 
cause Level B harassment of marine mammals in the proposed survey area. 
The effects of sounds from airgun operations might include one or more 
of the following: Tolerance, masking (of natural sounds including 
inter- and intra-specific calls), behavioral disturbance, temporary or 
permanent hearing impairment, or non-auditory physical or physiological 
effects (Richardson et al., 1995; Gordon et al., 2004; Nowacek et al., 
2007; Southall et al., 2007; Wright et al., 2007; Tyack, 2009). 
Permanent hearing impairment, in the unlikely event that it occurred, 
would constitute injury, but temporary threshold shift (TTS) is not an 
injury (Southall et al., 2007). Although the possibility cannot be 
entirely excluded, it is unlikely that the proposed project would 
result in any cases of temporary or permanent hearing impairment, or 
any significant non-auditory physical or physiological effects. Based 
on the available data and studies described here, some behavioral 
disturbance is expected. A more comprehensive review of these issues 
can be found in the NSF/USGS PEIS (2011) and L-DEO's ``Draft 
Environmental Assessment of a Marine Geophysical Survey by the R/V 
Marcus G. Langseth in the Atlantic Ocean off Cape Hatteras, September 
to October 2014.''

Tolerance

    Richardson et al. (1995) defines tolerance as the occurrence of 
marine mammals in areas where they are exposed to human activities or 
man-made 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) (Thorpe, 1963; 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 shown that marine mammals at distances more than a 
few kilometers from operating seismic vessels often show no apparent 
response (Malme et al., 1985; Richardson et al., 1986; Ljungblad et 
al., 1988; McCauley et al., 2000a). 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 and toothed whales, and (less 
frequently) pinnipeds have been shown to react behaviorally to airgun 
pulses

[[Page 35651]]

under some conditions, at other times marine mammals of all three types 
have shown no overt reactions. The relative responsiveness of baleen 
and toothed whales and pinnipeds are quite variable and depend on 
factors such as species, age, and previous exposures of the animal to 
human-generated sound.

Masking

    The term masking refers to the inability of a subject to recognize 
the occurrence of an acoustic stimulus as a result of the interference 
of another acoustic stimulus (Clark et al., 2009). Introduced 
underwater sound may, through masking, reduce the effective 
communication distance of a marine mammal species if the frequency of 
the source is close to that used as a signal by the marine mammal, and 
if the anthropogenic sound is present for a significant fraction of the 
time (Richardson et al., 1995).
    Masking effects of pulsed sounds (even from large arrays of 
airguns) on marine mammal calls and other natural sounds are expected 
to be limited. Because of the intermittent nature and low duty cycle of 
seismic airgun pulses, animals can emit and receive sounds in the 
relatively quiet intervals between pulses. However, in some situations, 
reverberation occurs for much or the entire interval between pulses 
(e.g., Simard et al., 2005; Clark and Gagnon, 2006) which could mask 
calls. Some baleen and toothed whales are known to continue calling in 
the presence of seismic pulses, and their calls can usually be heard 
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,b, 2006; and Dunn and Hernandez, 2009). 
However, Clark and Gagnon (2006) reported that fin whales in the North 
Atlantic Ocean went silent for an extended period starting soon after 
the onset of a seismic survey in the area. Similarly, there has been 
one report that sperm whales ceased calling when exposed to pulses from 
a very distant seismic ship (Bowles et al., 1994). However, more recent 
studies found that they continued calling in the presence of seismic 
pulses (Madsen et al., 2002; Tyack et al., 2003; Smultea et al., 2004; 
Holst et al., 2006; and Jochens et al., 2008). Dilorio and Clark (2009) 
found evidence of increased calling by blue whales during operations by 
a lower-energy seismic source (i.e., sparker). Dolphins and porpoises 
commonly are heard calling while airguns are operating (e.g., Gordon et 
al., 2004; Smultea et al., 2004; Holst et al., 2005a, b; and Potter et 
al., 2007). The sounds important to small odontocetes are predominantly 
at much higher frequencies than are the dominant components of airgun 
sounds, thus limiting the potential for masking.
    Marine mammals are thought to be able to compensate for masking by 
adjusting their acoustic behavior through shifting call frequencies, 
increasing call volume, and increasing vocalization rates. For example, 
blue whales are found to increase call rates when exposed to noise from 
seismic surveys in the St. Lawrence Estuary (Dilorio and Clark, 2009). 
The North Atlantic right whales exposed to high shipping noise 
increased call frequency (Parks et al., 2007), while some humpback 
whales respond to low-frequency active sonar playbacks by increasing 
song length (Miller et al., 2000). In general, NMFS expects the masking 
effects of seismic pulses to be minor, given the normally intermittent 
nature of seismic pulses.

Behavioral Disturbance

    Marine mammals may behaviorally react to sound when exposed to 
anthropogenic noise. Disturbance includes a variety of effects, 
including (but not limited to) subtle to conspicuous changes in 
behavior, movement, and displacement (Nowacek et al., 2007; Tyack, 
2009). Reactions to sound, if any, depend on species, state of 
maturity, experience, current activity, reproductive state, time of 
day, and many other factors (Richardson et al., 1995; Wartzok et al., 
2004; Southall et al., 2007; Weilgart, 2007). These behavioral 
reactions are often shown as: Changing durations of surfacing and 
dives, number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities; changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping); avoidance of areas where noise sources are located; and/or 
flight responses (e.g., pinnipeds flushing into the water from haul-
outs or rookeries). If a marine mammal does react briefly to an 
underwater sound by changing its behavior or moving a small distance, 
the impacts of the change are unlikely to be significant to the 
individual, let alone the stock or population. However, if a sound 
source displaces marine mammals from an important feeding or breeding 
area for a prolonged period, impacts on individuals and populations 
could be significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007).
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could be expected to be biologically significant if the 
change affects growth, survival, and/or reproduction. Some of these 
significant behavioral modifications include:
     Change in diving/surfacing patterns (such as those thought 
to be causing beaked whale stranding due to exposure to military mid-
frequency tactical sonar);
     Habitat abandonment due to loss of desirable acoustic 
environment; and
     Cessation of feeding or social interaction.
    The onset of behavioral disturbance from anthropogenic noise 
depends on both external factors (characteristics of noise sources and 
their paths) and the receiving animals (hearing, motivation, 
experience, demography) and is also difficult to predict (Richardson et 
al., 1995; Southall et al., 2007). Given the many uncertainties in 
predicting the quantity and types of impacts of noise on marine 
mammals, it is common practice to estimate how many mammals would be 
present within a particular distance of industrial activities and/or 
exposed to a particular level of sound. In most cases, this approach 
likely overestimates the numbers of marine mammals that would be 
affected in some biologically-important manner.
    Baleen Whales--Baleen whales generally tend to avoid operating 
airguns, but avoidance radii are quite variable (reviewed in Richardson 
et al., 1995; Gordon et al., 2004). Whales are often reported to show 
no overt reactions to pulses from large arrays of airguns at distances 
beyond a few kilometers, even though the airgun pulses remain well 
above ambient noise levels out to much longer distances. However, 
baleen whales exposed to strong noise pulses from airguns often react 
by deviating from their normal migration route and/or interrupting 
their feeding and moving away. In the cases of migrating gray 
(Eschrichtius robustus) and bowhead (Balaena mysticetus) whales, the 
observed changes in behavior appeared to be of little or no biological 
consequence to the animals (Richardson, et al., 1995). They simply 
avoided the sound source by displacing their migration route to varying 
degrees, but within the natural boundaries of the migration corridors 
(Malme et al., 1984; Malme and Miles, 1985; Richardson et al., 1995).
    Studies of gray, bowhead, and humpback whales have shown that 
seismic pulses with received levels of 160 to 170 dB re 1 [mu]Pa (rms) 
seem to cause obvious avoidance behavior in a

[[Page 35652]]

substantial fraction of the animals exposed (Malme et al., 1986, 1988; 
Richardson et al., 1995). In many areas, seismic pulses from large 
arrays of airguns diminish to those levels at distances ranging from 4 
to 15 km (2.2 to 8.1 nmi) from the source. A substantial proportion of 
the baleen whales within those distances may show avoidance or other 
strong behavioral reactions to the airgun array. Subtle behavioral 
changes sometimes become evident at somewhat lower received levels, and 
studies have shown that some species of baleen whales, notably bowhead, 
gray, and humpback whales, at times, show strong avoidance at received 
levels lower than 160 to 170 dB re 1 [mu]Pa (rms).
    Researchers have studied the responses of humpback whales to 
seismic surveys during migration, feeding during the summer months, 
breeding while offshore from Angola, and wintering offshore from 
Brazil. McCauley et al. (1998, 2000a) studied the responses of humpback 
whales off western Australia to a full-scale seismic survey with a 16-
airgun array (2,678 in \3\) and to a single airgun (20 in\3\) with 
source level of 227 dB re 1 [micro]Pa (p-p). In the 1998 study, they 
documented that avoidance reactions began at 5 to 8 km (2.7 to 4.3 nmi) 
from the array, and that those reactions kept most pods approximately 3 
to 4 km (1.6 to 2.2 nmi) from the operating seismic boat. In the 2000 
study, they noted localized displacement during migration of 4 to 5 km 
(2.2 to 2.7 nmi) by traveling pods and 7 to 12 km (3.8 to 6.5 nmi) by 
more sensitive resting pods of cow-calf pairs. Avoidance distances with 
respect to the single airgun were smaller but consistent with the 
results from the full array in terms of the received sound levels. The 
mean received level for initial avoidance of an approaching airgun was 
140 dB re 1 [mu]Pa (rms) for humpback pods containing females, and at 
the mean closest point of approach distance from the received level was 
143 dB re 1 [mu]Pa (rms). The initial avoidance response generally 
occurred at distances of 5 to 8 km (2.7 to 4.3 nmi) from the airgun 
array and 2 km (1.1 nmi) from the single airgun. However, some 
individual humpback whales, especially males, approached within 
distances of 100 to 400 m (328 to 1,312 ft), where the maximum received 
level was 179 dB re 1 [mu]Pa (rms) (McCauley et al., 1998, 2000b).
    Data collected by observers during several seismic surveys in the 
Northwest Atlantic 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 vs. 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 dB re 1 [mu]Pa (rms). 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.
    Studies have suggested that South Atlantic humpback whales in the 
South Atlantic Ocean wintering off Brazil may be displaced or even 
strand upon exposure to seismic surveys (Engel et al., 2004). 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).
    Reactions of migrating and feeding (but not wintering) gray whales 
to seismic surveys have been studied. Malme et al. (1986, 1988) studied 
the responses of feeding Eastern North 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) rms basis, and 
that 10 percent of feeding whales interrupted feeding at received 
levels of 163 dB re 1 [micro]Pa (rms). 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 North Pacific gray 
whales feeding off Sakhalin Island, Russia (Wursig et al., 1999; Gailey 
et al., 2007; Johnson et al., 2007; Yazvenko et al., 2007a, b), along 
with data on gray whales off British Columbia (Bain and Williams, 
2006).
    Various species of Balaenoptera (blue, sei, fin, and minke whales) 
have occasionally been seen in areas ensonified by airgun pulses 
(Stone, 2003; MacLean and Haley, 2004; Stone and Tasker, 2006), and 
calls from blue and fin whales have been localized in areas with airgun 
operations (e.g., McDonald et al., 1995; Dunn and Hernandez, 2009; 
Castellote et al., 2010). Sightings by observers on seismic vessels off 
the United Kingdom from 1997 to 2000 suggest that, during times of good 
sightability, sighting rates for mysticetes (mainly fin and sei whales) 
were similar when large arrays of airguns were shooting vs. silent 
(Stone, 2003; Stone and Tasker, 2006). However, these whales tended to 
exhibit localized avoidance, remaining significantly further (on 
average) from the airgun array during seismic operations compared with 
non-seismic periods (Stone and Tasker, 2006). Castellote et al. (2010) 
reported that singing fin whales in the Mediterranean moved away from 
an operating airgun array.
    Ship-based monitoring studies of baleen whales (including blue, 
fin, sei, minke, and humpback whales) in the Northwest Atlantic found 
that overall, this group had lower sighting rates during seismic vs. 
non-seismic periods (Moulton and Holst, 2010). Baleen whales as a group 
were also seen significantly farther from the vessel during seismic 
compared with non-seismic periods, and they were more often seen to be 
swimming away from the operating seismic vessel (Moulton and Holst, 
2010). Blue and minke whales were initially sighted significantly 
farther from the vessel during seismic operations compared to non-
seismic periods; the same trend was observed for fin whales (Moulton 
and Holst, 2010). Minke whales were most often observed to be swimming 
away from the vessel when seismic operations were underway (Moulton and 
Holst, 2010).
    Data on short-term reactions by cetaceans to impulsive noises are 
not necessarily indicative of long-term or biologically significant 
effects. It is not known whether impulsive sounds affect reproductive 
rate or distribution and habitat use in subsequent days or years. 
However, gray whales have continued to migrate annually along the west 
coast of North America with substantial increases in the population 
over recent years, despite intermittent seismic exploration (and much 
ship traffic) in that area for decades (Appendix A in

[[Page 35653]]

Malme et al., 1984; Richardson et al., 1995; Allen and Angliss, 2010). 
The Western North Pacific gray whale population did not seem affected 
by a seismic survey in its feeding ground during a previous year 
(Johnson et al., 2007). Similarly, bowhead whales have continued to 
travel to the eastern Beaufort Sea each summer, and their numbers have 
increased notably, despite seismic exploration in their summer and 
autumn range for many years (Richardson et al., 1987; Allen and 
Angliss, 2010). The history of coexistence between seismic surveys and 
baleen whales suggests that brief exposures to sound pulses from any 
single seismic survey are unlikely to result in prolonged effects.
    Toothed Whales--There is little systematic information available 
about reactions of toothed whales to noise pulses. Few studies similar 
to the more extensive baleen whale/seismic pulse work summarized above 
have been reported for toothed whales. However, there are recent 
systematic studies on sperm whales (e.g., Gordon et al., 2006; Madsen 
et al., 2006; Winsor and Mate, 2006; Jochens et al., 2008; Miller et 
al., 2009). There is an increasing amount of information about 
responses of various odontocetes to seismic surveys based on monitoring 
studies (e.g., Stone, 2003; Smultea et al., 2004; Moulton and Miller, 
2005; Bain and Williams, 2006; Holst et al., 2006; Stone and Tasker, 
2006; Potter et al., 2007; Hauser et al., 2008; Holst and Smultea, 
2008; Weir, 2008; Barkaszi et al., 2009; Richardson et al., 2009; 
Moulton and Holst, 2010).
    Seismic operators and Protected Species Observers (PSOs) on seismic 
vessels regularly see dolphins and other small toothed whales near 
operating airgun arrays, but in general there is a tendency for most 
delphinids to show some avoidance of operating seismic vessels (e.g., 
Goold, 1996a,b,c; Calambokidis and Osmek, 1998; Stone, 2003; Moulton 
and Miller, 2005; Holst et al., 2006; Stone and Tasker, 2006; Weir, 
2008; Richardson et al., 2009; Barkaszi et al., 2009; Moulton and 
Holst, 2010). Some dolphins seem to be attracted to the seismic vessel 
and floats, and some ride the bow wave of the seismic vessel even when 
large arrays of airguns are firing (e.g., Moulton and Miller, 2005). 
Nonetheless, small toothed whales more often tend to head away, or to 
maintain a somewhat greater distance from the vessel, when a large 
array of airguns is operating than when it is silent (e.g., Stone and 
Tasker, 2006; Weir, 2008; Barry et al., 2010; Moulton and Holst, 2010). 
In most cases, the avoidance radii for delphinids appear to be small, 
on the order of one km (0.5 nmi) or less, and some individuals show no 
apparent avoidance. Based on observations from seismic surveys off the 
United Kingdom, small odontocetes exhibited greater avoidance to 
operating airguns than previously reported (Stone et al., 2003; Gordon 
et al., 2004; Stone and Tasker, 2006). The observer data also indicated 
that small odontocetes were feeding less and were interacting with the 
vessel less during active seismic surveys. Captive bottlenose dolphins 
and beluga whales (Delphinapterus leucas) exhibited changes in behavior 
when exposed to strong pulsed sounds similar in duration to those 
typically used in seismic surveys (Finneran et al., 2000, 2002, 2005). 
However, the animals tolerated high, received levels of sound before 
exhibiting aversive behaviors.
    Results of reactions to seismic operations for porpoises depend on 
species. The limited available data suggest that harbor porpoises show 
stronger avoidance of seismic operations than do Dall's porpoises 
(Phocoenoides dalli) (Stone, 2003; MacLean and Koski, 2005; Bain and 
Williams, 2006; Stone and Tasker, 2006). Dall's porpoises seem 
relatively tolerant of airgun operations (MacLean and Koski, 2005; Bain 
and Williams, 2006), although they too have been observed to avoid 
large arrays of operating airguns (Calambokidis and Osmek, 1998; Bain 
and Williams, 2006). This apparent difference in responsiveness of 
these two porpoise species is consistent with their relative 
responsiveness to boat traffic and some other acoustic sources 
(Richardson et al., 1995; Southall et al., 2007).
    Most studies of sperm whales exposed to airgun sounds indicate that 
the sperm whale shows considerable tolerance of airgun pulses (e.g., 
Stone, 2003; Moulton et al., 2005, 2006a; Stone and Tasker, 2006; Weir, 
2008). In most cases the whales do not show strong avoidance, and they 
continue to call. However, controlled exposure experiments in the Gulf 
of Mexico indicate that foraging behavior was altered upon exposure to 
airgun sound (Jochens et al., 2008; Miller et al., 2009; Tyack, 2009).
    There are almost no specific data on the behavioral reactions of 
beaked whales to seismic surveys. However, some northern bottlenose 
whales remained in the general area and continued to produce high-
frequency clicks when exposed to sound pulses from distant seismic 
surveys (Gosselin and Lawson, 2004; Laurinolli and Cochrane, 2005; 
Simard et al., 2005). Most beaked whales are illusive and tend to avoid 
approaching vessels of other types (e.g., Wursig et al., 1998). They 
may also dive for an extended period when approached by a vessel (e.g., 
Kasuya, 1986), although it is uncertain how much longer such dives may 
be as compared to dives by undisturbed beaked whales, which also are 
often quite long (Baird et al., 2006; Tyack et al., 2006). Based on a 
single observation, Aguilar-Soto et al. (2006) suggested that foraging 
efficiency of Cuvier's beaked whales may be reduced by close approach 
of vessels. In any event, it is likely that most beaked whales would 
also show strong avoidance of an approaching seismic vessel, although 
this has not been documented definitively. In fact, Moulton and Holst 
(2010) reported 15 sightings of beaked whales during seismic studies in 
the Northwest Atlantic; seven of those sightings were made at times 
when at least one airgun was operating. There was little evidence to 
indicate that beaked whale behavior was affected by airgun operations; 
sighting rates and distances were similar during seismic and non-
seismic periods (Moulton and Holst, 2010).
    There are indications that some beaked whales may strand when naval 
exercises involving mid-frequency sonar operation are ongoing nearby 
(e.g., Simmonds and Lopez-Jurado, 1991; Frantzis, 1998; NOAA and USN, 
2001; Jepson et al., 2003; Hildebrand, 2005; Barlow and Gisiner, 2006; 
see also the ``Stranding and Mortality'' section in this notice). These 
strandings are apparently a disturbance response, although auditory or 
other injuries or other physiological effects may also be involved. 
Whether beaked whales would ever react similarly to seismic surveys is 
unknown. Seismic survey sounds are quite different from those of the 
sonar in operation during the above-cited incidents.
    Odontocete reactions to large arrays of airguns are variable and, 
at least for delphinids and Dall's porpoises, seem to be confined to a 
smaller radius than has been observed for the more responsive of some 
mysticetes. However, other data suggest that some odontocete species, 
including harbor porpoises, may be more responsive than might be 
expected given their poor low-frequency hearing. Reactions at longer 
distances may be particularly likely when sound propagation conditions 
are conducive to transmission of the higher frequency components of 
airgun sound to the animals' location (DeRuiter et al., 2006; Goold and 
Coates, 2006; Tyack et al., 2006; Potter et al., 2007).
    Pinnipeds--Information on the reaction of pinniped species to 
pulsed seismic airgun sounds is limited. Based on early observations, 
pinnipeds appear

[[Page 35654]]

to be quite tolerant of pulsed sounds. Other reports indicate that 
pinnipeds were tolerant of loud, pulsed sounds when they were strongly 
attracted to an area for feeding or reproductive purposes (Mate and 
Harvey, 1987; Reeves et al., 1996). In most recent studies, avoidance 
of pinnipeds during seismic surveys has been reported as being 
relatively small, within 100 to few hundred meters. Many seals remained 
within 100 to 200 m (328.1 to 656.2 ft) of the survey tracklines while 
an operating seismic survey passed (Harris et al., 2001; Moulton and 
Lawson, 2002). Other observations made during seismic surveys in the 
Chukchi and Beaufort Seas reported that pinnipeds (i.e., ringed seals 
[Phoca hispida]) were observed less when seismic airguns were operating 
than when they were silent (Miller et al., 2005). In Puget Sound, 
sighting distances for harbor seals and California sea lions (Zalophus 
californianus) tended to be larger when airguns were operating 
(Calambokidis and Osmek, 1998). Previous telemetry work suggests that 
avoidance and other behavioral reactions may be stronger than evident 
to date from visual studies (Thompson et al., 1998). Overall, 
behavioral reactions from pinnipeds to pulsed seismic sounds are 
variable. It is expected that localized avoidance of operating seismic 
airguns may occur; however, it cannot be guaranteed that these species 
would fully avoid an operating seismic vessel during active surveys.

Hearing Impairment and Other Physical Effects

    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, 
Carder, Schlundt, and Ridgway, 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 called the initial threshold shift. If the 
threshold shift eventually returns to zero (i.e., the threshold returns 
to the pre-exposure value), it is called temporary threshold shift 
(TTS) (Southall et al., 2007).
    Researchers have studied TTS in certain captive odontocetes and 
pinnipeds exposed to strong sounds (reviewed in Southall et al., 2007). 
However, there has been no specific documentation of TTS let alone 
permanent hearing damage, i.e., permanent threshold shift (PTS), in 
free-ranging marine mammals exposed to sequences of airgun pulses 
during realistic field conditions.
    Temporary Threshold Shift--TTS is the mildest form of hearing 
impairment that can occur during exposure to a strong sound (Kryter, 
1985). While experiencing TTS, the hearing threshold rises and a sound 
must be stronger in order to be heard. At least in terrestrial mammals, 
TTS can last from minutes or hours to (in cases of strong TTS) days. 
For sound exposures at or somewhat above the TTS threshold, hearing 
sensitivity in both terrestrial and marine mammals recovers rapidly 
after exposure to the noise ends. Few data on sound levels and 
durations necessary to elicit mild TTS have been obtained for marine 
mammals, and none of the published data concern TTS elicited by 
exposure to multiple pulses of sound. Available data on TTS in marine 
mammals are summarized in Southall et al. (2007). Table 1 (above) 
presents the estimated distances from the Langseth's airguns at which 
the received energy level (per pulse, flat-weighted) would be expected 
to be greater than or equal to 180 or 190 dB re 1 [micro]Pa (rms).
    To avoid the potential for injury (i.e., Level A harassment), NMFS 
(1995, 2000) concluded that cetaceans and pinnipeds should not be 
exposed to pulsed underwater noise at received levels exceeding 180 and 
190 dB re 1 [mu]Pa (rms), respectively. The established 180 and 190 dB 
(rms) criteria are not considered to be the levels above which TTS 
might occur. Rather, they are the received levels above which, in the 
view of a panel of bioacoustics specialists convened by NMFS before TTS 
measurements for marine mammals started to become available, one could 
not be certain that there would be no injurious effects, auditory or 
otherwise, to marine mammals. NMFS also assumes that cetaceans and 
pinnipeds exposed to levels exceeding 160 dB re 1 [mu]Pa (rms) may 
experience Level B harassment.
    For toothed whales, researchers have derived TTS information for 
odontocetes from studies on the bottlenose dolphin and beluga. The 
experiments show that exposure to a single impulse at a received level 
of 207 kPa (or 30 psi, p-p), which is equivalent to 228 dB re 1 Pa (p-
p), resulted in a 7 and 6 dB TTS in the beluga whale at 0.4 and 30 kHz, 
respectively. Thresholds returned to within 2 dB of the pre-exposure 
level within 4 minutes of the exposure (Finneran et al., 2002). For the 
one harbor porpoise tested, the received level of airgun sound that 
elicited onset of TTS was lower (Lucke et al., 2009). If these results 
from a single animal are representative, it is inappropriate to assume 
that onset of TTS occurs at similar received levels in all odontocetes 
(cf. Southall et al., 2007). Some cetaceans apparently can incur TTS at 
considerably lower sound exposures than are necessary to elicit TTS in 
the beluga or bottlenose dolphin.
    For baleen whales, there are no data, direct or indirect, on levels 
or properties of sound that are required to induce TTS. The frequencies 
to which baleen whales are most sensitive are assumed to be lower than 
those to which odontocetes are most sensitive, and natural background 
noise levels at those low frequencies tend to be higher. As a result, 
auditory thresholds of baleen whales within their frequency band of 
best hearing are believed to be higher (less sensitive) than are those 
of odontocetes at their best frequencies (Clark and Ellison, 2004). 
From this, it is suspected that received levels causing TTS onset may 
also be higher in baleen whales than those of odontocetes (Southall et 
al., 2007).
    Permanent Threshold Shift--When PTS occurs, there is physical 
damage to the sound receptors in the ear. In severe cases, there can be 
total or partial deafness, whereas in other cases, the animal has an 
impaired ability to hear sounds in specific frequency ranges (Kryter, 
1985). There is no specific evidence that exposure to pulses of airgun 
sound can cause PTS in any marine mammal, even with large arrays of 
airguns. However, given the possibility that mammals close to an airgun 
array might incur at least mild TTS, there has been further speculation 
about the possibility that some individuals occurring very close to 
airguns might incur PTS (e.g., Richardson et al., 1995, p. 372ff; 
Gedamke et al., 2008). Single or occasional occurrences of mild TTS are 
not indicative of permanent auditory damage, but repeated or (in some 
cases) single exposures to a level well above that causing TTS onset 
might elicit PTS.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals, but are assumed to be similar to those in humans and 
other terrestrial mammals (Southall et al., 2007). PTS might occur at a 
received sound level at least several dBs above that inducing mild TTS 
if the animal were exposed to strong sound pulses with rapid rise 
times. Based on data from terrestrial mammals, a precautionary 
assumption is that the PTS threshold for impulse sounds (such as airgun 
pulses as received close to the source) is at least 6 dB higher than 
the

[[Page 35655]]

TTS threshold on a peak-pressure basis, and probably greater than 6 dB 
(Southall et al., 2007).
    Given the higher level of sound necessary to cause PTS as compared 
with TTS, it is considerably less likely that PTS would occur. Baleen 
whales generally avoid the immediate area around operating seismic 
vessels, as do some other marine mammals. Some pinnipeds show avoidance 
reactions to airguns, but their avoidance reactions are generally not 
as strong or consistent as those of cetaceans, and occasionally they 
seem to be attracted to operating seismic vessels (NMFS, 2010).
    Non-auditory Physiological Effects--Non-auditory physiological 
effects or injuries that theoretically might occur in marine mammals 
exposed to strong underwater sound include stress, neurological 
effects, bubble formation, resonance, and other types of organ or 
tissue damage (Cox et al., 2006; Southall et al., 2007). Studies 
examining such effects are limited. However, 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 perhaps 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, very little is known about the potential for seismic 
survey sounds (or other types of strong 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. Marine mammals that show 
behavioral avoidance of seismic vessels, including most baleen whales, 
some odontocetes, and some pinnipeds, are especially unlikely to incur 
non-auditory 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 termed 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 are known to strand for a variety of reasons, such 
as infectious agents, biotoxicosis, starvation, fishery interaction, 
ship strike, unusual oceanographic or weather events, sound exposure, 
or combinations of these stressors sustained concurrently or in series. 
However, the cause or causes of most strandings are unknown (Geraci et 
al., 1976; Eaton, 1979; Odell et al., 1980; Best, 1982). Numerous 
studies suggest that the physiology, behavior, habitat relationships, 
age, or condition of cetaceans may cause them to strand or might pre-
dispose them to strand when exposed to another phenomenon. These 
suggestions are consistent with the conclusions of numerous other 
studies that have demonstrated that combinations of dissimilar 
stressors commonly combine to kill an animal or dramatically reduce its 
fitness, even though one exposure without the other does not produce 
the same result (Chroussos, 2000; Creel, 2005; DeVries et al., 2003; 
Fair and Becker, 2000; Foley et al., 2001; Moberg, 2000; Relyea, 2005a, 
2005b; Romero, 2004; Sih et al., 2004).
    Strandings Associated with Military Active Sonar--Several sources 
have published lists of mass stranding events of cetaceans in an 
attempt to identify relationships between those stranding events and 
military active sonar (Hildebrand, 2004; IWC, 2005; Taylor et al., 
2004). For example, based on a review of stranding records between 1960 
and 1995, the International Whaling Commission (2005) identified ten 
mass stranding events and concluded that, out of eight stranding events 
reported from the mid-1980s to the summer of 2003, seven had been 
coincident with the use of mid-frequency active sonar and most involved 
beaked whales.
    Over the past 12 years, there have been five stranding events 
coincident with military mid-frequency active sonar use in which 
exposure to sonar is believed to have been a contributing factor to 
strandings: Greece (1996); the Bahamas (2000); Madeira (2000); Canary 
Islands (2002); and Spain (2006). Refer to Cox et al. (2006) for a 
summary of common features shared by the strandings events in Greece 
(1996), Bahamas (2000), Madeira (2000), and Canary Islands (2002); and 
Fernandez et al., (2005) for an additional summary of the Canary 
Islands 2002 stranding event. USGS would not be using military sonars; 
therefore, NMFS does not expect these potential effects to marine 
mammals.
    Potential for Stranding from Seismic Surveys--Marine mammals close 
to underwater detonations of high explosives can be killed or severely 
injured, and the auditory organs are especially susceptible to injury 
(Ketten et al., 1993; Ketten, 1995). However, explosives are no longer 
used in marine waters for commercial seismic surveys or (with rare 
exceptions) for seismic research. These methods have been replaced 
entirely by airguns or related non-explosive pulse generators. Airgun 
pulses are less energetic and have slower rise times, and there is no 
specific evidence that they can cause serious injury, death, or 
stranding even in the case of large airgun arrays. However, the 
association of strandings of beaked whales with naval exercises 
involving mid-frequency active sonar (non-pulse sound) and, in one 
case, the co-occurrence of an L-DEO seismic survey (Malakoff, 2002; Cox 
et al., 2006), has raised the possibility that beaked whales exposed to 
strong ``pulsed'' sounds could also be susceptible to injury and/or 
behavioral reactions that can lead to stranding (e.g., Hildebrand, 
2005; Southall et al., 2007).
    Specific sound-related processes that lead to strandings and 
mortality are not well documented, but may include:
    (1) Swimming in avoidance of a sound into shallow water;
    (2) A change in behavior (such as a change in diving behavior) that 
might contribute to tissue damage, gas bubble formation, hypoxia, 
cardiac arrhythmia, hypertensive hemorrhage or other forms of trauma;
    (3) A physiological change such as a vestibular response leading to 
a behavioral change or stress-induced hemorrhagic diathesis, leading in 
turn to tissue damage; and
    (4) Tissue damage directly from sound exposure, such as through 
acoustically-mediated bubble formation and growth or acoustic resonance 
of tissues.

Some of these mechanisms are unlikely to apply in the case of impulse 
sounds. However, there are indications that gas-

[[Page 35656]]

bubble disease (analogous to ``the bends''), induced in supersaturated 
tissue by a behavioral response to acoustic exposure, could be a 
pathologic mechanism for the strandings and mortality of some deep-
diving cetaceans exposed to sonar. The evidence for this remains 
circumstantial and associated with exposure to naval mid-frequency 
sonar, not seismic surveys (Cox et al., 2006; Southall et al., 2007).
    Seismic pulses and mid-frequency sonar signals are quite different, 
and some mechanisms by which sonar sounds have been hypothesized to 
affect beaked whales are unlikely to apply to airgun pulses. Sounds 
produced by airgun arrays are broadband impulses with most of the 
energy below one kHz. Typical military mid-frequency sonar emits non-
impulse sounds at frequencies of 2 to 10 kHz, generally with a 
relatively narrow bandwidth at any one time. A further difference 
between seismic surveys and naval exercises is that naval exercises can 
involve sound sources on more than one vessel. Thus, it is not 
appropriate to expect that the same effects to marine mammals would 
result from military sonar and seismic surveys. However, evidence that 
sonar signals can, in special circumstances, lead (at least indirectly) 
to physical damage and mortality (e.g., Balcomb and Claridge, 2001; 
NOAA and USN, 2001; Jepson et al., 2003; Fern[aacute]ndez et al., 2004, 
2005; Hildebrand 2005; Cox et al., 2006) suggests that caution is 
warranted when dealing with exposure of marine mammals to any high-
intensity sound.
    There is no conclusive evidence of cetacean strandings or deaths at 
sea as a result of exposure to seismic surveys, but a few cases of 
strandings in the general area where a seismic survey was ongoing have 
led to speculation concerning a possible link between seismic surveys 
and strandings. Suggestions that there was a link between seismic 
surveys and strandings of humpback whales in Brazil (Engel et al., 
2004) were not well founded (IAGC, 2004; IWC, 2007). In September 2002, 
there was a stranding of two Cuvier's beaked whales in the Gulf of 
California, Mexico, when the L-DEO vessel R/V Maurice Ewing was 
operating a 20 airgun (8,490 in\3\) array in the general area. The link 
between the stranding and the seismic surveys was inconclusive and not 
based on any physical evidence (Hogarth, 2002; Yoder, 2002). 
Nonetheless, the Gulf of California incident plus the beaked whale 
strandings near naval exercises involving use of mid-frequency sonar 
suggests a need for caution in conducting seismic surveys in areas 
occupied by beaked whales until more is known about effects of seismic 
surveys on those species (Hildebrand, 2005). No injuries of beaked 
whales are anticipated during the proposed study because of:
    (1) The high likelihood that any beaked whales nearby would avoid 
the approaching vessel before being exposed to high sound levels, and
    (2) Differences between the sound sources operated by L-DEO and 
those involved in the naval exercises associated with strandings.

Potential Effects of Other Acoustic Devices

Multi-Beam Echosounder
    USGS would operate the Kongsberg EM 122 multi-beam echosounder from 
the source vessel during the planned study. Sounds from the multi-beam 
echosounder are very short pulses, occurring for 2 to 15 ms once every 
5 to 20 s, depending on water depth. Most of the energy in the sound 
pulses emitted by this multi-beam echosounder is at frequencies near 12 
kHz, and the maximum source level is 242 dB re 1 [mu]Pa (rms). The beam 
is narrow (1 to 2[deg]) in fore-aft extent and wide (150[deg]) in the 
cross-track extent. Each ping consists of eight (in water greater than 
1,000 m deep) or four (in water less than 1,000 m deep) successive fan-
shaped transmissions (segments) at different cross-track angles. Any 
given mammal at depth near the trackline would be in the main beam for 
only one or two of the nine 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 would 
receive only limited amounts of pulse energy because of the short 
pulses. Animals close to the ship (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 a multi-beam 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 TTS.
    Navy sonars that have been 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 multi-beam echosounder. The area of 
possible influence of the multi-beam 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 USGS's 
operations, the individual pulses would be very short, and a given 
mammal would not receive many of the downward-directed pulses as the 
vessel passes by. Possible effects of a multi-beam echosounder on 
marine mammals are described below.
    Stranding--In 2013, an International Scientific Review Panel 
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 multi-beam 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 has 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 lead to the eventual entrapment and mortality of the whales within 
the Loza Lagoon system (e.g., the survey vessel transiting in a north-
south direction on the shelf break parallel to the shore may have 
trapped the animals between the sound source and the shore driving them 
towards the Loza Lagoon). They concluded that for odontocete cetaceans 
that hear well in the 10 to 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 (Southall et al., 2013).
    Masking--Marine mammal communications would not be masked 
appreciably by the multi-beam echosounder signals given the low duty 
cycle of the multi-beam echosounder and the brief period when an 
individual mammal is likely to be within its beam. Furthermore, in the 
case of baleen whales, the multi-beam echosounder 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

[[Page 35657]]

other sound sources appear to vary by species and circumstance. 
Observed reactions have included silencing and dispersal by sperm 
whales (Watkins et al., 1985), increased vocalizations and no dispersal 
by pilot whales (Rendell and Gordon, 1999), and the previously-
mentioned beachings by beaked whales. During exposure to a 21 to 25 kHz 
``whale-finding'' sonar with a source level of 215 dB re 1 [mu]Pa, gray 
whales reacted by orienting slightly away from the source and being 
deflected from their course by approximately 200 m (656.2 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, 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 that would be emitted by the multi-beam echosounder used by USGS, 
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 a multi-beam 
echosounder.
    Hearing Impairment and Other Physical Effects--Given recent 
stranding events that have been associated with the operation of naval 
sonar, there is concern that mid-frequency sonar sounds can cause 
serious impacts to marine mammals (see above). However, the multi-beam 
echosounder proposed for use by USGS is quite different than sonar used 
for Navy operations. Pulse duration of the multi-beam echosounder is 
very short relative to the naval sonar. Also, at any given location, an 
individual marine mammal would be in the beam of the multi-beam 
echosounder for much less time given the generally downward orientation 
of the beam and its narrow fore-aft beamwidth; Navy sonar often uses 
near-horizontally-directed sound. Those factors would all reduce the 
sound energy received from the multi-beam echosounder rather 
drastically relative to that from naval sonar. NMFS believes that the 
brief exposure of marine mammals to one pulse, or small numbers of 
signals, from the multi-beam echosounder is not likely to result in the 
harassment of marine mammals.
Sub-Bottom Profiler
    USGS would also operate a sub-bottom profiler from the source 
vessel during the proposed survey. Sounds from the sub-bottom profiler 
are very short pulses, occurring for 1 to 4 ms once every few (3 to 6) 
seconds. Most of the energy in the sound pulses emitted by the sub-
bottom 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 204 
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 sub-bottom 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 in order to be subjected to sound 
levels that could cause TTS.
    Masking--Marine mammal communications would not be masked 
appreciably by the sub-bottom profiler 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 sub-bottom profiler signals do not overlap with the predominant 
frequencies in the calls, which would avoid significant masking.
    Behavioral Responses--Marine mammal behavioral reactions to other 
pulsed sound sources are discussed above, and responses to the sub-
bottom profiler are likely to be similar to those for other pulsed 
sources if received at the same levels. However, the pulsed signals 
from the sub-bottom profiler are considerably weaker than those from 
the multi-beam echosounder. Therefore, behavioral responses are not 
expected unless marine mammals are very close to the source.
    Hearing Impairment and Other Physical Effects--It is unlikely that 
the sub-bottom 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 sub-bottom profiler is 
usually operated simultaneously with other higher-power acoustic 
sources, including airguns. 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 sub-bottom 
profiler.

Potential Effects of Vessel Movement and Collisions

    Vessel movement in the vicinity of marine mammals has the potential 
to result in either a behavioral response or a direct physical 
interaction. Both scenarios are discussed below in this section.
    Behavioral Responses to Vessel Movement--There are limited data 
concerning marine mammal behavioral responses to vessel traffic and 
vessel noise, and a lack of consensus among scientists with respect to 
what these responses mean or whether they result in short-term or long-
term adverse effects. In those cases where there is a busy shipping 
lane or where there is a large amount of vessel traffic, marine mammals 
(especially low frequency specialists) 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

[[Page 35658]]

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' reaction varied when exposed to vessel noise and 
traffic. In some cases, beluga whales exhibited rapid swimming from 
ice-breaking vessels up to 80 km (43.2 nmi) 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; fin whales changed from mostly negative (e.g., avoidance) to 
uninterested reactions; right whales apparently continued the same 
variety of responses (negative, uninterested, and positive responses) 
with little change; and humpbacks dramatically changed from mixed 
responses that were often negative to reactions that were often 
strongly positive. Watkins (1986) summarized that ``whales near shore, 
even in regions with low vessel traffic, generally have become less 
wary of boats and their noises, and they have appeared to be less 
easily disturbed than previously. In particular locations with intense 
shipping and repeated approaches by boats (such as the whale-watching 
areas of Stellwagen Bank), more and more whales had positive reactions 
to familiar vessels, and they also occasionally approached other boats 
and yachts in the same ways.''
    Although the radiated sound from the Langseth would be audible to 
marine mammals over a large distance, it is unlikely that marine 
mammals would respond behaviorally (in a manner that NMFS would 
consider harassment under the MMPA) to low-level distant shipping noise 
as the animals in the area are likely to be habituated to such noises 
(Nowacek et al., 2004). In light of these facts, NMFS does not expect 
the Langseth's movements to result in Level B harassment.
    Vessel Strike--Ship strikes of cetaceans can cause major wounds, 
which may lead to the death of the animal. An animal at the surface 
could be struck directly by a vessel, a surfacing animal could hit the 
bottom of a vessel, or an animal just below the surface could be cut by 
a vessel's propeller. The severity of injuries typically depends on the 
size and speed of the vessel (Knowlton and Kraus, 2001; Laist et al., 
2001; Vanderlaan and Taggart, 2007).
    The most vulnerable marine mammals are those that spend extended 
periods of time at the surface in order to restore oxygen levels within 
their tissues after deep dives (e.g., the sperm whale). In addition, 
some baleen whales, such as the North Atlantic right whale, seem 
generally unresponsive to vessel sound, making them more susceptible to 
vessel collisions (Nowacek et al., 2004). These species are primarily 
large, slow moving whales. Smaller marine mammals (e.g., bottlenose 
dolphin) move quickly through the water column and are often seen 
riding the bow wave of large ships. Marine mammal responses to vessels 
may include avoidance and changes in dive pattern (NRC, 2003).
    An examination of all known ship strikes from all shipping sources 
(civilian and military) indicates vessel speed is a principal factor in 
whether a vessel strike results in death (Knowlton and Kraus, 2001; 
Laist et al., 2001; Jensen and Silber, 2003; Vanderlaan and Taggart, 
2007). In assessing records in which vessel speed was known, 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 13 kts (24.1 km/hr, 14.9 mph).
    USGS's proposed operation of one source vessel for the proposed 
survey is relatively small in scale compared to the number of 
commercial ships transiting at higher speeds in the same area on an 
annual basis. The probability of vessel and marine mammal interactions 
occurring during the proposed survey is unlikely due to the Langseth's 
slow operational speed, which is typically 4.5 kts (8.5 km/hr, 5.3 
mph). Outside of seismic operations, the Langseth's cruising speed 
would be approximately 10 kts (18.5 km/hr, 11.5 mph), which is 
generally below the speed at which studies have noted reported 
increases of marine mammal injury or death (Laist et al., 2001).
    As a final point, the Langseth has a number of other advantages for 
avoiding ship strikes as compared to most commercial merchant vessels, 
including the following: The Langseth's bridge offers good visibility 
to visually monitor for marine mammal presence; Protected Species 
Visual Observers (PSVO) posted during operations would scan the ocean 
for marine mammals and would be required to report visual sightings of 
marine mammal presence to crew; and the PSVOs receive extensive 
training that covers the fundamentals of visual observing for marine 
mammals and information about marine mammals and their identification 
at sea. In addition, during airgun operations, a passive acoustic 
monitoring (PAM) system would be deployed from the Langseth that may 
alert the vessel of the presence of marine mammals in the vicinity of 
the vessel.

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 of 
seismic equipment and cables. The large airgun array and hydrophone 
streamer carries the risk of entanglement for marine mammals. Wildlife, 
especially slow moving individuals, such as large whales, have a low 
probability of becoming entangled due to the slow speed of the survey 
vessel and onboard monitoring efforts. There are no recorded cases of 
entanglement of marine mammals during the conduct of over 8 years of 
seismic surveys on the Langseth. In May 2011, there was one recorded 
entanglement of an olive ridley sea turtle (Lepidochelys olivacea) in 
the Langseth's barovanes after the conclusion of a seismic survey off 
Costa Rica. However, the barovanes would not be deployed from the 
Langseth during USGS's proposed seismic survey. There have been cases 
of baleen whales,

[[Page 35659]]

mostly gray whales (Heyning, 1990), becoming entangled in fishing 
lines. The probability for entanglement of marine mammals is considered 
not significant because of the vessel speed and the monitoring efforts 
onboard the survey vessel.
    The potential effects to marine mammals described in this section 
of the document do not take into consideration the proposed monitoring 
and mitigation measures described later in this document (see the 
``Proposed Mitigation'' and ``Proposed Monitoring and Reporting'' 
sections) which, as noted, are designed to effect the least practicable 
impact on affected marine mammal species and stocks.

Anticipated Effects on Marine Mammal Habitat

    The proposed seismic survey is not anticipated to have any 
permanent impact on habitats used by the marine mammals in the proposed 
survey area, including the food sources they use (i.e., fish and 
invertebrates). Additionally, no physical damage to any habitat is 
anticipated as a result of conducting the proposed seismic survey. 
While it is anticipated that the specified activity may result in 
marine mammals avoiding certain areas due to temporary ensonification, 
this impact to habitat is temporary and was considered in further 
detail earlier in this document, as behavioral modification. The main 
impact associated with the proposed activity would be temporarily 
elevated noise levels and the associated direct effects on marine 
mammals in any particular area of the proposed project area, previously 
discussed in this notice. The proposed 2014 and 2015 seismic survey is 
not operating in a small, defined location. During the proposed 3,165 
km (1,709 nmi) and 3,115 km (1,682 nmi) of tracklines in 2014 and 2015, 
respectively, the vessel would continuously move along the tracklines 
during the survey. The next section discusses the potential impacts of 
anthropogenic sound sources on common marine mammal prey in the 
proposed survey area (i.e., fish and invertebrates).

Anticipated Effects on Fish

    One reason for the adoption of airguns as the standard energy 
source for marine seismic surveys is that, unlike explosives, they have 
not been associated with large-scale fish kills. However, existing 
information on the impacts of seismic surveys on marine fish and 
invertebrate populations is limited. There are three types of potential 
effects of exposure to seismic surveys: (1) Pathological, (2) 
physiological, and (3) behavioral. Pathological effects involve lethal 
and temporary or permanent sub-lethal injury. Physiological effects 
involve temporary and permanent primary and secondary stress responses, 
such as changes in levels of enzymes and proteins. Behavioral effects 
refer to temporary and (if they occur) permanent changes in exhibited 
behavior (e.g., startle and avoidance behavior). The three categories 
are interrelated in complex ways. For example, it is possible that 
certain physiological and behavioral changes could potentially lead to 
an ultimate pathological effect on individuals (i.e., mortality).
    The specific received sound levels at which permanent adverse 
effects to fish potentially could occur are little studied and largely 
unknown. Furthermore, the available information on the impacts of 
seismic surveys on marine fish is from studies of individuals or 
portions of a population; there have been no studies at the population 
scale. The studies of individual fish have often been on caged fish 
that were exposed to airgun pulses in situations not representative of 
an actual seismic survey. Thus, available information provides limited 
insight on possible real-world effects at the ocean or population 
scale. This makes drawing conclusions about impacts on fish problematic 
because, ultimately, the most important issues concern effects on 
marine fish populations, their viability, and their availability to 
fisheries.
    Hastings and Popper (2005), Popper (2009), and Popper and Hastings 
(2009a,b) provided recent critical reviews of the known effects of 
sound on fish. The following sections provide a general synopsis of the 
available information on the effects of exposure to seismic and other 
anthropogenic sound as relevant to fish. The information comprises 
results from scientific studies of varying degrees of rigor plus some 
anecdotal information. Some of the data sources may have serious 
shortcomings in methods, analysis, interpretation, and reproducibility 
that must be considered when interpreting their results (see Hastings 
and Popper, 2005). Potential adverse effects of the program's sound 
sources on marine fish are noted.
    Pathological Effects--The potential for pathological damage to 
hearing structures in fish depends on the energy level of the received 
sound and the physiology and hearing capability of the species in 
question. For a given sound to result in hearing loss, the sound must 
exceed, by some substantial amount, the hearing threshold of the fish 
for that sound (Popper, 2005). The consequences of temporary or 
permanent hearing loss in individual fish on a fish population are 
unknown; however, they likely depend on the number of individuals 
affected and whether critical behaviors involving sound (e.g., predator 
avoidance, prey capture, orientation and navigation, reproduction, 
etc.) are adversely affected.
    Little is known about the mechanisms and characteristics of damage 
to fish that may be inflicted by exposure to seismic survey sounds. Few 
data have been presented in the peer-reviewed scientific literature. As 
far as USGS and NMFS know, there are only two papers with proper 
experimental methods, controls, and careful pathological investigation 
implicating sounds produced by actual seismic survey airguns in causing 
adverse anatomical effects. One such study indicated anatomical damage, 
and the second indicated TTS in fish hearing. The anatomical case is 
McCauley et al. (2003), who found that exposure to airgun sound caused 
observable anatomical damage to the auditory maculae of pink snapper 
(Pagrus auratus). This damage in the ears had not been repaired in fish 
sacrificed and examined almost two months after exposure. On the other 
hand, Popper et al. (2005) documented only TTS (as determined by 
auditory brainstem response) in two of three fish species from the 
Mackenzie River Delta. This study found that broad whitefish (Coregonus 
nasus) exposed to five airgun shots were not significantly different 
from those of controls. During both studies, the repetitive exposure to 
sound was greater than would have occurred during a typical seismic 
survey. However, the substantial low-frequency energy produced by the 
airguns (less than 400 Hz in the study by McCauley et al. [2003] and 
less than approximately 200 Hz in Popper et al. [2005]) likely did not 
propagate to the fish because the water in the study areas was very 
shallow (approximately nine m in the former case and less than two m in 
the latter). Water depth sets a lower limit on the lowest sound 
frequency that would propagate (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

[[Page 35660]]

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).
    An experiment of the effects of a single 700 in\3\ airgun was 
conducted in Lake Meade, Nevada (USGS, 1999). The data were used in an 
Environmental Assessment of the effects of a marine reflection survey 
of the Lake Meade fault system by the National Park Service (Paulson et 
al., 1993, in USGS, 1999). The airgun was suspended 3.5 m (11.5 ft) 
above a school of threadfin shad in Lake Meade and was fired three 
successive times at a 30 second interval. Neither surface inspection 
nor diver observations of the water column and bottom found any dead 
fish.
    Some studies have reported, some equivocally, that mortality of 
fish, fish eggs, or larvae can occur close to seismic sources 
(Kostyuchenko, 1973; Dalen and Knutsen, 1986; Booman et al., 1996; 
Dalen et al., 1996). Some of the reports claimed seismic effects from 
treatments quite different from actual seismic survey sounds or even 
reasonable surrogates. However, Payne et al. (2009) reported no 
statistical differences in mortality/morbidity between control and 
exposed groups of capelin eggs or monkfish larvae. Saetre and Ona 
(1996) applied a `worst-case scenario' mathematical model to 
investigate the effects of seismic energy on fish eggs and larvae. They 
concluded that mortality rates caused by exposure to seismic surveys 
are so low, as compared to natural mortality rates, that the impact of 
seismic surveying on recruitment to a fish stock must be regarded as 
insignificant.
    Physiological Effects--Physiological effects refer to cellular and/
or biochemical responses of fish to acoustic stress. Such stress 
potentially could affect fish populations by increasing mortality or 
reducing reproductive success. Primary and secondary stress responses 
of fish after exposure to seismic survey sound appear to be temporary 
in all studies done to date (Sverdrup et al., 1994; Santulli et al., 
1999; McCauley et al., 2000a,b). The periods necessary for the 
biochemical changes to return to normal are variable and depend on 
numerous aspects of the biology of the species and of the sound 
stimulus.
    Behavioral Effects--Behavioral effects include changes in the 
distribution, migration, mating, and catchability of fish populations. 
Studies investigating the possible effects of sound (including seismic 
survey sound) on fish behavior have been conducted on both uncaged and 
caged individuals (e.g., Chapman and Hawkins, 1969; Pearson et al., 
1992; Santulli et al., 1999; Wardle et al., 2001; Hassel et al., 2003). 
Typically, in these studies fish exhibited a sharp startle response at 
the onset of a sound followed by habituation and a return to normal 
behavior after the sound ceased.
    The Minerals Management Service (MMS, 2005) assessed the effects of 
a proposed seismic survey in Cook Inlet. The seismic survey proposed 
using three vessels, each towing two, four-airgun arrays ranging from 
1,500 to 2,500 in\3\. MMS noted that the impact to fish populations in 
the survey area and adjacent waters would likely be very low and 
temporary. MMS 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 
survey. 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 surveys may depend on the species in question 
and the nature of the fishery (season, duration, fishing method). They 
may also depend on the age of the fish, its motivational state, its 
size, and numerous other factors that are difficult, if not impossible, 
to quantify at this point, given such limited data on effects of 
airguns on fish, particularly under realistic at-sea conditions.

Anticipated Effects on Invertebrates

    The existing body of information on the impacts of seismic survey 
sound on marine invertebrates is very limited. However, there is some 
unpublished and very limited evidence of the potential for adverse 
effects on invertebrates, thereby justifying further discussion and 
analysis of this issue. The three types of potential effects of 
exposure to seismic surveys on marine invertebrates are pathological, 
physiological, and behavioral. Based on the physical structure of their 
sensory organs, marine invertebrates appear to be specialized to 
respond to particle displacement components of an impinging sound field 
and not to the pressure component (Popper et al., 2001).
    The only information available on the impacts of seismic surveys on 
marine invertebrates involves studies of individuals; there have been 
no studies at the population scale. Thus, available information 
provides limited insight on possible real-world effects at the regional 
or ocean scale. The most important aspect of potential impacts concerns 
how exposure to seismic survey sound ultimately affects invertebrate 
populations and their viability, including availability to fisheries.
    Literature reviews of the effects of seismic and other underwater 
sound on invertebrates were provided by Moriyasu et al. (2004) and 
Payne et al. (2008). 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 provided in Appendix D of the NSF/USGS PEIS.
    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

[[Page 35661]]

field experiments on adult crustaceans (Christian et al., 2003, 2004; 
DFO, 2004) and adult cephalopods (McCauley et al., 2000a,b) exposed to 
seismic survey sound have not resulted in any significant pathological 
impacts on the animals. It has been suggested that exposure to 
commercial seismic survey activities has injured giant squid (Guerra et 
al., 2004), but the article provides little evidence to support this 
claim. Tenera Environmental (2011b) reported that Norris and Mohl 
(1983, summarized in Mariyasu et al., 2004) observed lethal effects in 
squid (Loligo vulgaris) at levels of 246 to 252 dB after 3 to 11 
minutes.
    Andre et al. (2011) exposed four species of cephalopods (Loligo 
vulgaris, Sepia officinalis, Octopus vulgaris, and Ilex coindetii), 
primarily cuttlefish, to two hours of continuous 50 to 400 Hz 
sinusoidal wave sweeps at 157+/-5 dB re 1 [mu]Pa while captive in 
relatively small tanks. They reported morphological and ultrastructural 
evidence of massive acoustic trauma (i.e., permanent and substantial 
alterations [lesions] of statocyst sensory hair cells) to the exposed 
animals that increased in severity with time, suggesting that 
cephalopods are particularly sensitive to low frequency sound. The 
received SPL was reported as 157+/-5 dB re 1 [mu]Pa, with peak levels 
at 175 dB re 1 [mu]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. Primary and secondary 
stress responses (i.e., changes in haemolymph levels of enzymes, 
proteins, etc.) of crustaceans have been noted several days or months 
after exposure to seismic survey sounds (Payne et al., 2007). It was 
noted however, that no behavioral impacts were exhibited by crustaceans 
(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., 2000a,b). In other cases, no behavioral impacts 
were noted (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).

Proposed Mitigation

    In order to issue an Incidental Take Authorization (ITA) 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 impact on such species or stock and its 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance, and the availability of such species or 
stock for taking for certain subsistence uses (where relevant).
    USGS has reviewed the following source documents and has 
incorporated a suite of appropriate mitigation measures into their 
project description.
    (1) Protocols used during previous NSF and USGS-funded seismic 
research cruises as approved by NMFS and detailed in the NSF/USGS PEIS;
    (2) Previous IHA applications and IHAs approved and authorized by 
NMFS; 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 proposed activities, USGS and/or its designees have 
proposed to implement the following mitigation measures for marine 
mammals:
    (1) Planning Phase;
    (2) Proposed exclusion zones around the airgun(s);
    (3) Power-down procedures;
    (4) Shut-down procedures;
    (5) Ramp-up procedures; and
    (6) Special procedures for situations or species of concern.
    Planning Phase--Mitigation of potential impacts from the proposed 
activities began during the planning phases of the proposed activities. 
USGS considered whether the research objectives could be met with a 
smaller source than the full, 36-airgun array (6,600 in\3\) used on the 
Langseth, and determined that the standard 36-airgun array with a total 
volume of approximately 6,600 in\3\ was appropriate. USGS also worked 
with L-DEO and NSF to identify potential time periods to carry out the 
survey taking into consideration key factors such as environmental 
conditions (i.e., the seasonal presence of marine mammals and other 
protected species), weather conditions, equipment, and optimal timing 
for other proposed seismic surveys using the Langseth. Most marine 
mammal species are expected to occur in the study area year-round, so 
altering the timing of the proposed project from spring and summer 
months likely would result in no net benefits for those species.
    Proposed Exclusion Zones--USGS use radii to designate exclusion and 
buffer zones and to estimate take for marine mammals. Table 1 
(presented earlier in this document) shows the distances at which one 
would expect marine mammal exposures to received sound levels (160 and 
180/190 dB) from the 36 airgun array and a single airgun. (The 180 dB 
and 190 dB level shut-down criteria are applicable to cetaceans and 
pinnipeds, respectively, as specified by NMFS [2000].) USGS used these 
levels to establish the exclusion and buffer zones.
    If the PSVO 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 shut-down if necessary (see ``Shut-
down Procedures''). Table 1 summarizes the calculated distances at 
which sound levels (160, 180 and 190 dB [rms]) are expected to be 
received from the 36 airgun array and the single airgun operating in 
deep water depths. Received sound levels have been calculated by USGS, 
in relation to distance and direction from the airguns, for the 36 
airgun array and for the single 1900LL 40 in\3\ airgun, which would be 
used during power-downs.
    Power-down Procedures--A power-down involves decreasing the number 
of

[[Page 35662]]

airguns in use to one airgun, such that the radius of the 180 dB or 190 
dB zone is decreased to the extent that the observed marine mammal(s) 
are no longer in or about to enter the exclusion zone for the full 
airgun array. During a power-down for mitigation, L-DEO would operate 
one small airgun. The continued operation of one airgun is intended to 
(a) alert marine mammals to the presence of the seismic vessel in the 
area; and (b) retain the option of initiating a ramp-up to full 
operations under poor visibility conditions. In contrast, a shut-down 
occurs when all airgun activity is suspended.
    If the PSVO detects a marine mammal outside the exclusion zone that 
is likely to enter the exclusion zone, USGS would power-down the 
airguns to reduce the size of the 180 dB or 190 dB exclusion zone 
before the animal is within the exclusion zone. Likewise, if a mammal 
is already within the exclusion zone, when first detected USGS would 
power-down the airguns immediately. During a power-down of the airgun 
array, USGS would operate the single 40 in\3\ airgun, which has a 
smaller exclusion zone. If the PSVO detects a marine mammal within or 
near the smaller exclusion zone around that single airgun (see Table 
1), USGS would shut-down the airgun (see next section).
    Resuming Airgun Operations After a Power-down--Following a power-
down, the Langseth will not resume full airgun activity until the 
marine mammal has cleared the 180 or 190 dB exclusion zone (see Table 
1). The PSVO would consider the animal to have cleared the exclusion 
zone if:
     The PSVO has visually observed the animal leave the 
exclusion zone, or
     A PSVO 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 vessel has transited outside the original 180 dB or 
190 dB exclusion zone after a 10 minute wait period.
    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).
    Because the vessel would have transited away from the vicinity of 
the original sighting during the 10 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 PSVOs would continually monitoring the exclusion 
zone for the full source level while the mitigation airgun is firing. 
On average, PSVOs can observe to the horizon (10 km or 5.4 nmi) from 
the height of the Langseth's observation deck and should be able to 
state with a reasonable degree of confidence whether a marine mammal 
would be encountered within this distance before resuming airgun 
operations at full-power.
    Shut-down Procedures--USGS would shut-down the operating airgun(s) 
if a marine mammal is seen within or approaching the exclusion zone for 
the single airgun. USGS would implement a shut-down:
    (1) If an animal enters the exclusion zone of the single airgun 
after USGS has initiated a power-down; or
    (2) If an animal is initially seen within the exclusion zone of the 
single airgun when more than one airgun (typically the full airgun 
array) is operating (and it is not practical or adequate to reduce 
exposure to less than 180 dB [rms] or 190 dB [rms]).
    Considering the conservation status for the North Atlantic right 
whale, the airguns would be shut-down immediately in the unlikely event 
that this species is observed, regardless of the distance from the 
Langseth. Ramp-up would only begin if the North Atlantic right whale 
has not been seen for 30 minutes.
    Resuming Airgun Operations After a Shut-down--Following a shut-down 
in excess of 10 minutes, the Langseth crew would initiate a ramp-up 
with the smallest airgun in the array (40 in\3\). The crew would turn 
on additional airguns in a sequence such that the source level of the 
array would increase in steps not exceeding 6 dB per five-minute period 
over a total duration of approximately 30 minutes. During ramp-up, the 
PSVOs would monitor the exclusion zone, and if they sight a marine 
mammal, the Langseth crew would implement a power-down or shut-down 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 shut-down described earlier and the PSVOs 
would monitor the full exclusion zone and would implement a power-down 
or shut-down if necessary.
    If the full exclusion zone is not visible to the PSVO 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 shut-down at night or during poor visibility conditions 
(i.e., 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 ramp-up of the airguns if a 
marine mammal is sighted within or near the applicable exclusion zones.
    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. USGS would follow a ramp-up 
procedure when the airgun array begins operating after a 10 minute 
period without airgun operations or when a power-down or shut-down has 
exceeded that period. USGS and L-DEO have used similar periods 
(approximately 8 to 10 minutes) during previous USGS and L-DEO seismic 
surveys.
    Ramp-up would begin with the smallest airgun in the array (40 
in\3\). Airguns would be added 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 
(i.e., the time it takes to achieve full operation of the airgun 
array). During ramp-up, the PSVOs would monitor the exclusion zone, and 
if marine mammals are sighted, USGS would implement a power-down or

[[Page 35663]]

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, USGS 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 airgun array would not be ramped-up from a complete shut-down at 
night or during poor visibility conditions (i.e., 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. USGS would not initiate a ramp-up of the 
airguns if a marine mammal is sighted within or near the applicable 
exclusion zones.

Use of a Small-Volume Airgun During Turns and Maintenance

    For short-duration equipment maintenance activities, USGS would 
employ the use of a small-volume airgun (i.e., 40 in\3\ ``mitigation 
airgun'') to deter marine mammals from being within the immediate area 
of the seismic operations. The mitigation airgun would be operated at 
approximately one shot per minute and would not be operated for longer 
than three hours in duration. The seismic survey's tracklines are 
continuous around turns and no mitigation airgun would be necessary. 
For longer-duration equipment maintenance or repair activities (greater 
than three hours), USGS would shut-down the seismic equipment and not 
involve using the mitigation airgun.
    During brief transits (e.g., less than three hours), one mitigation 
airgun would continue operating. The ramp-up procedure would still be 
followed when increasing the source levels from one airgun to the full 
airgun array. However, keeping one airgun firing would avoid the 
prohibition of a ``cold start'' during darkness or other periods of 
poor visibility. Through use of this approach, seismic operations may 
resume without the 30 minute observation period of the full exclusion 
zone required for a ``cold start,'' and without ramp-up if operating 
with the mitigation airgun for under 10 minutes, or with ramp-up if 
operating with the mitigation airgun over 10 minutes. PSOs would be on 
duty whenever the airguns are firing during daylight, during the 30 
minute periods prior to ramp-ups.
    Special Procedures for Situations or Species of Concern--It is 
unlikely that a North Atlantic right whale would be encountered during 
the proposed seismic survey, but if so, the airguns would be shut-down 
immediately if one is visually sighted at any distance from the vessel 
because of its rarity and conservation status. The airgun array shall 
not resume firing (with ramp-up) until 30 minutes after the last 
documented North Atlantic right whale visual sighting. Concentrations 
of humpback, sei, fin, blue, and/or sperm whales would be avoided if 
possible (i.e., exposing concentrations of animals to 160 dB), and the 
array would be powered-down 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.).

Mitigation Conclusions

    NMFS has carefully evaluated the applicant's proposed mitigation 
measures and has considered a range of other measures in the context of 
ensuring that NMFS prescribes the means of effecting the least 
practicable impact on the affected marine mammal species and stocks and 
their habitat. NMFS's evaluation of potential measures included 
consideration of the following factors in relation to one another:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure is expected to minimize adverse impacts 
to marine mammals;
    (2) The proven or likely efficacy of the specific measure to 
minimize adverse impacts as planned; and
    (3) 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 below:
    (1) Avoidance or minimization of injury or death of marine mammal 
wherever possible (goals 2, 3, and 4 may contribute to this goal).
    (2) A reduction in the numbers of marine mammals (total number of 
number at biologically important time or location) exposed to received 
levels of airgun operations, or other activities expected 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 received levels of airgun operations, or other activities expected 
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 received 
levels of airgun operations, or other activities expected 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 of 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 NMFS's evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS or recommended by the public, 
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 and Reporting

    In order to issue an ITA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking.'' The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for ITAs 
must include the suggested means of accomplishing the necessary 
monitoring and reporting that would result in increased knowledge of 
the species and of the level of taking or impacts on populations of 
marine mammals that are expected to be present in the proposed action 
area. USGS submitted a marine mammal monitoring plan as part of the IHA 
application. It can be found in Section 13 of the IHA application. The 
plan may be modified or supplemented based on comments or new 
information received from the public during the

[[Page 35664]]

public comment period or from the peer review panel.
    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 in general to generate more data 
to contribute to the analyses mentioned below;
    (2) An increase in our understanding of how many marine mammals are 
likely to be exposed to levels of seismic airguns that we associate 
with specific adverse effects, such as behavioral harassment, TTS or 
PTS;
    (3) An increase in our understanding of how marine mammals respond 
to stimuli expected to result in take and how 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:
     Behavioral observations in the presence of stimuli 
compared to observations in the absence of stimuli (need to be able to 
accurately predict received level, distance from source, and other 
pertinent information);
     Physiological measurements in the presence of stimuli 
compared to observations in the absence of stimuli (need to be able to 
accurately predict receive level, distance from the source, and other 
pertinent information);
     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

    USGS proposes to sponsor marine mammal monitoring during the 
proposed project, in order to implement the proposed mitigation 
measures that require real-time monitoring, and to satisfy the 
anticipated monitoring requirements of the IHA. USGS's proposed 
``Monitoring Plan'' is described below this section. The monitoring 
work described here has been planned as a self-contained project 
independent of any other related monitoring projects that may be 
occurring simultaneously in the same region. USGS is prepared to 
discuss coordination of its monitoring program with any related work 
that might be done by other groups insofar as this is practical and 
desirable.

Vessel-Based Visual Monitoring

    PSVOs would be based aboard the seismic source vessel and would 
watch for marine mammals near the vessel during daytime airgun 
operations and during any ramp-ups of the airguns at night. PSVOs 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 shut-
down (i.e., greater than approximately 10 minutes for this proposed 
cruise). When feasible, PSVOs would conduct observations during daytime 
periods when the seismic system is not operating (such as during 
transits) for comparison of sighting rates and behavior with and 
without airgun operations and between acquisition periods. Based on 
PSVO observations, the airguns would be powered-down or shut-down when 
marine mammals are observed within or about to enter a designated 
exclusion zone.
    During seismic operations in the northwest Atlantic Ocean off the 
Eastern Seaboard, at least five PSOs (four PSVOs and one Protected 
Species Acoustic Observer [PSAO]) would be based aboard the Langseth. 
USGS would appoint the PSOs with NMFS's concurrence. Observations would 
take place during ongoing daytime operations and nighttime ramp-ups of 
the airguns. During the majority of seismic operations, two PSVOs would 
be on duty from the observation tower (i.e., the best available vantage 
point on the source vessel) to monitor marine mammals near the seismic 
vessel. Use of two simultaneous PSVOs would increase the effectiveness 
of detecting animals near the source vessel. However, during meal times 
and bathroom breaks, it is sometimes difficult to have two PSVOs on 
effort, but at least one PSVO would be on duty. PSVO(s) would be on 
duty in shifts no longer than 4 hours in duration.
    Two PSVOs would also be on visual watch during all daytime ramp-ups 
of the seismic airguns. A third PSAO would monitor the PAM 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 
PSVOs on duty from the observation tower, and a third PSAO on PAM. 
Other ship's crew would also be instructed to assist in detecting 
marine mammals and implementing mitigation requirements (if practical). 
Before the start of the seismic survey, the crew would be given 
additional instruction on how to do so.
    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 PSVO would have 
a good view around the entire vessel. During daytime, the PSVO(s) 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 or low-light conditions, night vision 
devices (monoculars) and a forward looking infrared (FLIR) camera would 
be available, when required. Laser range-finding binoculars (Leica LRF 
1200 laser rangefinder or equivalent) would be available to assist with 
distance estimation. Those are useful in training observers to estimate 
distances visually, but are generally not useful in measuring distances 
to animals directly; that is done primarily with the reticles in the 
binoculars.
    When marine mammals are detected within or about to enter the 
designated exclusion zone, the airguns would immediately be powered-
down or shut-down if necessary. The PSVO(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 
animal is confirmed to have left the exclusion 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).

Vessel-Based Passive Acoustic Monitoring

    Vessel-based, towed PAM would complement the visual 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. PAM can be used in addition to visual 
observations to improve detection, identification, and localization of 
cetaceans. The PAM system would serve to alert visual observers (if on 
duty) when vocalizing cetaceans are detected. It is only useful when 
marine mammals call, but it does not depend on good visibility. It 
would be monitored in real-time so that the PSVOs can be advised when 
cetaceans are acoustically detected.
    The PAM system consists of both hardware (i.e., hydrophones) and

[[Page 35665]]

software (i.e., Pamguard). The ``wet end'' of the system consists of a 
towed hydrophone array that is 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 is attached to the 
free end of the cable, and the cable is typically towed at depths 20 m 
(65.6 ft) or less. The array would be deployed from a winch located on 
the back deck. A deck cable would connect from the winch to the main 
computer laboratory where the acoustic station, signal conditioning, 
and processing system would be located. The acoustic signals received 
by the hydrophones are amplified, digitized, and then processed by the 
Pamguard software. The PAM system, which has a configuration of 4 
hydrophones, can detect a frequency bandwidth of 10 Hz to 200 kHz.
    One PSAO, an expert bioacoustician (in addition to the four PSVOs) 
with primary responsibility for PAM, would be onboard the Langseth. The 
expert bioacoustician would design and set up the PAM system and be 
present to operate, oversee, and troubleshoot any technical problems 
with the PAM system during the proposed survey. The towed hydrophones 
would ideally be monitored by the PSAO 24 hours per day while within 
the proposed seismic survey area during airgun operations, and during 
most periods when the Langseth is underway while the airguns are not 
operating. However, PAM may not be possible if damage occurs to the 
array or back-up systems during operations. The primary PAM 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 PSAO 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 PSAO monitoring 
the acoustical data would be on shift for no greater than six hours at 
a time. All PSOs are expected to rotate through the PAM position, 
although the expert PSAO (most experienced) would be on PAM duty more 
frequently.
    When a vocalization is detected while visual observations (during 
daylight) are in progress, the PSAO would contact the PSVO immediately, 
to alert him/her to the presence of cetaceans (if they have not already 
been seen), and to allow a power-down or shut-down to be initiated, if 
required. When bearings (primary and mirror-image) to calling 
cetacean(s) are determined, the bearings would be relayed to the 
PSVO(s) to help him/her sight the calling animal. During non-daylight 
hours, when a cetacean is detected by acoustic monitoring and may be 
close to the source vessel, the Langseth crew would be notified 
immediately so that the proper mitigation measure may be implemented.
    The information regarding the call would be entered 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. The acoustic 
detection can also be recorded for further analysis.

PSO Data and Documentation

    PSVOs 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. Data would be used to estimate 
numbers of animals potentially `taken' by harassment. They would also 
provide information needed to order a power-down or shut-down of the 
airguns when a marine mammal is within or near the appropriate 
exclusion zone. Observations would also be made during daytime periods 
when the Langseth is underway without seismic operations. There would 
also be opportunities to collect baseline biological data during the 
transits to, from, and through the study area.
    When a sighting is made, the following information about the 
sighting would be recorded:
    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, Beaufort 
sea state and wind force, visibility, and sun glare.
    The data listed under (2) would also be recorded 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.
    All observations and ramp-ups, power-downs, or shut-downs would be 
recorded in a standardized format. The PSVOs would record this 
information onto datasheets. During periods between watches and periods 
when operations are suspended, those data would be entered into a 
laptop computer running a custom electronic database. The accuracy of 
the data entry would be verified by computerized data validity checks 
as the data are entered and by subsequent manual checking of the 
database. These procedures would allow initial summaries of data to be 
prepared during and shortly after the field program, and would 
facilitate transfer of the data to statistical, graphical, and other 
programs for further processing and archiving.
    Results from the vessel-based observations would provide:
    1. The basis for real-time mitigation (airgun power-down or shut-
down).
    2. Information needed to estimate the number of marine mammals 
potentially taken by harassment, which must be reported to NMFS.
    3. Data on the occurrence, distribution, and activities of marine 
mammals in the area where the seismic study is conducted.
    4. Information to compare the distance and distribution of marine 
mammals relative to the source vessel at times with and without seismic 
activity.
    5. Data on the behavior and movement patterns of marine mammals 
seen at times with and without seismic activity.

Proposed Reporting

    USGS would submit a comprehensive report to NMFS and NSF within 90 
days after the end of phase 1 in 2014 and another comprehensive report 
to NMFS and NSF within 90 days after the end of phase 2 in 2015 for the 
proposed cruise. The report would describe the proposed operations that 
were conducted and sightings of marine mammals within the vicinity of 
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 (i.e., dates, times, locations, 
activities, associated seismic survey activities, and associated PAM 
detections). The report would minimally include:
     Summaries of monitoring effort--total hours, total 
distances, and distribution of marine mammals through the study period 
accounting for Beaufort sea state and wind force, and other factors 
affecting visibility and detectability of marine mammals;
     Analyses of the effects of various factors influencing 
detectability of

[[Page 35666]]

marine mammals including Beaufort sea state and wind force, number of 
PSOs, and fog/glare;
     Species composition, occurrence, and distribution of 
marine mammals sightings including date, water depth, numbers, age/
size/gender, and group sizes; and analyses of the effects of seismic 
operations;
     Sighting rates of marine mammals during periods with and 
without airgun activities (and other variables that could affect 
detectability);
     Initial sighting distances versus airgun activity state;
     Closest point of approach versus airgun activity state;
     Observed behaviors and types of movements versus airgun 
activity state;
     Numbers of sightings/individuals seen versus airgun 
activity state; and
     Distribution around the source vessel versus airgun 
activity state.
    The report would also include estimates of the number and nature of 
exposures that could result in ``takes'' of marine mammals by 
harassment or in other ways. After the report is considered final, it 
would be publicly available on the NMFS, USGS and NSF Web sites at: 
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#iha, http://woodshole.er.usgs.gov/project-pages/environmental_compliance/index.html, and http://www.nsf.gov/geo/oce/encomp/index.jsp.
    Notification of Injured or Dead Marine Mammals--In the 
unanticipated event that the specified activity clearly causes the take 
of a marine mammal in a manner not permitted by the authorization (if 
issued), such as an injury, serious injury, or mortality (e.g., ship-
strike, gear interaction, and/or entanglement), the USGS shall 
immediately cease the specified activities and immediately report the 
incident to the Incidental Take Program Supervisor, Permits and 
Conservation Division, Office of Protected Resources, NMFS, at 301-427-
8401 and/or by email to noaa.gov">Jolie.Harrison@noaa.gov and 
noaa.gov">Howard.Goldstein@noaa.gov, the NMFS Greater Atlantic Region Marine 
Mammal Stranding Network at 866-755-6622 (noaa.gov">Mendy.Garron@noaa.gov), and 
the NMFS Southeast Region Marine Mammal Stranding Network at 877-433-
8299 (noaa.gov">Blair.Mase@noaa.gov and noaa.gov">Erin.Fougeres@noaa.gov). The report must 
include the following information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Name and type of vessel involved;
     Vessel's speed during and leading up to the incident;
     Description of the incident;
     Status of all sound source used 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 animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    USGS shall not resume its activities until NMFS is able to review 
the circumstances of the prohibited take. NMFS shall work with USGS to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. The USGS may not resume 
their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that USGS discovers an injured or dead marine mammal, 
and the lead PSO determines that the cause of the injury or death is 
unknown and the death is relatively recent (i.e., in less than a 
moderate state of decomposition as NMFS describes in the next 
paragraph), the USGS would immediately report the incident to the 
Incidental Take Program Supervisor, Permits and Conservation Division, 
Office of Protected Resources, at 301-427-8401 and/or by email to 
noaa.gov">Jolie.Harrison@noaa.gov and noaa.gov">Howard.Goldstein@noaa.gov, the NMFS Greater 
Atlantic Region Marine Mammal Stranding Network (866-755-6622) and/or 
by email to the Greater Atlantic Regional Stranding Coordinator 
(noaa.gov">Mendy.Garron@noaa.gov), and the NMFS Southeast Region Marine Mammal 
Stranding Network (877-433-8299) and/or by email to the Southeast 
Regional Stranding Coordinator (noaa.gov">Blair.Mase@noaa.gov) and Southeast 
Regional Stranding Program Administrator (noaa.gov">Erin.Fougeres@noaa.gov). The 
report must include the same information identified in the paragraph 
above this section. Activities may continue while NMFS reviews the 
circumstances of the incident. NMFS would work with the USGS to 
determine whether modifications in the activities are appropriate.
    In the event that USGS discovers an injured or dead marine mammal, 
and the lead PSO determines that the injury or death is not associated 
with or related to the authorized activities (e.g., previously wounded 
animal, carcass with moderate to advanced decomposition, or scavenger 
damage), the USGS would report the incident to the Incidental Take 
Program Supervisor, Permits and Conservation Division, Office or 
Protected Resources, at 301-427-8401 and/or by email to 
noaa.gov">Jolie.Harrison@noaa.gov and noaa.gov">Howard.Goldstein@noaa.gov, the NMFS Greater 
Atlantic Region Marine Mammal Stranding Network (866-755-6622), and/or 
by email to the Greater Atlantic Regional Stranding Coordinator 
(noaa.gov">Mendy.Garron@noaa.gov), and the NMFS Southeast Region Marine Mammal 
Stranding Network (877-433-8299), and/or by email to the Southeast 
Regional Stranding Coordinator (noaa.gov">Blair.Mase@noaa.gov) and Southeast 
Regional Stranding Program Administrator (noaa.gov">Erin.Fougeres@noaa.gov), 
within 24 hours of the discovery. The USGS would provide photographs or 
video footage (if available) or other documentation of the stranded 
animal sighting to NMFS and the Marine Mammal Stranding Network. 
Activities may continue while NMFS reviews the circumstances of the 
incident.

Estimated Take by Incidental Harassment

    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment].

[[Page 35667]]



      Table 3--NMFS's Current Underwater Acoustic Exposure Criteria
------------------------------------------------------------------------
                     Impulsive (non-explosive) sound
-------------------------------------------------------------------------
          Criterion           Criterion definition        Threshold
------------------------------------------------------------------------
Level A harassment (injury).  Permanent threshold   180 dB re 1
                               shift (PTS) (Any      [micro]Pa-m (root
                               level above that      means square [rms])
                               which is known to     (cetaceans).
                               cause TTS).          190 dB re 1
                                                     [micro]Pa-m (rms)
                                                     (pinnipeds).
Level B harassment..........  Behavioral            160 dB re 1
                               disruption (for       [micro]Pa-m (rms).
                               impulsive noise).
Level B harassment..........  Behavioral            120 dB re 1
                               disruption (for       [micro]Pa-m (rms).
                               continuous noise).
------------------------------------------------------------------------

    Level B harassment is anticipated and proposed to be authorized as 
a result of the proposed marine seismic survey in the northwest 
Atlantic Ocean off the Eastern Seaboard. Acoustic stimuli (i.e., 
increased underwater sound) generated during the operation of the 
seismic airgun array are expected to result in the behavioral 
disturbance of some marine mammals. There is no evidence that the 
planned activities for which USGS seeks the IHA could result in injury, 
serious injury, or mortality. The required mitigation and monitoring 
measures would minimize any potential risk for injury, serious injury, 
or mortality.
    The following sections describe USGS's methods to estimate take by 
incidental harassment and present the applicant's and NMFS's estimates 
of the numbers of marine mammals that could be affected during the 
proposed seismic program in the northwest Atlantic Ocean. The estimates 
are based on a consideration of the number of marine mammals that could 
be harassed by seismic operations with the 36 airgun array to be used. 
The length of the proposed 2D seismic survey area in 2014 is 
approximately 3,165 km (1,704 nmi) and in 2015 is approximately 3,115 
km (1,682 nmi) in the U.S. ECS region of the Eastern Seaboard in the 
Atlantic Ocean, as depicted in Figure 1 of the IHA application. For 
estimating take and other calculations, the 2015 tracklines are assumed 
to be identical in length to the 2014 tracklines (even though they are 
slightly shorter).
    USGS assumes that, during simultaneous operations of the airgun 
array and the other sources, any marine mammals close enough to be 
affected by the multi-beam echosounder and sub-bottom profiler would 
already be affected by the airguns. However, whether or not the airguns 
are operating simultaneously with the other sources, marine mammals are 
expected to exhibit no more than short-term and inconsequential 
responses to the multi-beam echosounder and sub-bottom profiler given 
their characteristics (e.g., narrow, downward-directed beam) and other 
considerations described previously. Such reactions are not considered 
to constitute ``taking'' (NMFS, 2001). Therefore, USGS provided no 
additional allowance for animals that could be affected by sound 
sources other than airguns.
    Density estimates for marine mammals within the vicinity of the 
proposed study area are limited. Density data for species found along 
the East Coast of the U.S. generally extend slightly outside of the 
U.S. EEZ. The proposed study area, however, is well beyond the U.S. 
EEZ, and is well off the continental shelf break. The proposed survey 
lines for the proposed 2014 survey are located in the far eastern 
portion of the proposed study area, primarily within the area where 
little to no density data are currently available. It was determined 
that the best available information for density data (for those species 
where density data existed) of species located off the U.S. East Coast 
was housed at the Strategic Environmental and Development Program 
(SERDP)/National Aeronautics and Space Administration (NASA)/NOAA 
Marine Animal Model Mapper and OBIS-SEAMAP database. Within this 
database, the model outputs for all four seasons from the U.S. 
Department of the Navy Operating Area (OPAREA) Density Estimates (NODE) 
for the Northeast OPAREA and Southeast OPAREA (Department of the Navy 
2007a, 2007b) were used to determine the mean density (animals per 
square kilometer) for 19 of the 38 marine mammals with the potential to 
occur in the proposed study area. Those species include fin, minke, 
Atlantic spotted, bottlenose, long-finned and short-finned pilot, 
pantropical spotted, Risso's, short-beaked common, striped, sperm, 
rough-toothed, dwarf and pygmy sperm, Sowerby's, Blainville's, 
Gervais', True's, and Cuvier's beaked whales. Within the NODE document, 
the density calculations and models both took into account detection 
probability ([fnof][0]) and availability (g[0]) biases. Model outputs 
for each season are available in the database. The data from the NODE 
summer density models, which include the months of June, July, and 
August, were used as the 2014 survey is proposed to take place between 
late August and early September. Of the seasonal NODE density models 
available, it is expected that the summer models are the most accurate 
and robust as the survey data used to create all of the models were 
obtained during summer months. The models for the winter, spring, and 
fall are derived from the data collected during the summer surveys, and 
therefore are expected to be less representative of actual species 
density during those seasons.
    For those species of marine mammals that did not have density model 
outputs within the SERDP/NASA/NOAA and OBIS-SEAMAP database, or for 
those species with density outputs that did not extend into the 
proposed study area at all (i.e., all four pinniped species and sei 
whale), but for which OBIS sightings data within or adjacent to the 
proposed study area exist, the requested take authorization for the 
mean group size of the species of marine mammal is included. The mean 
group sizes were determined based on data reported from the Cetacean 
and Turtle Assessment Program (CeTAP) surveys (CeTAP, 1982).
    The estimated numbers of individuals potentially exposed to sound 
during the proposed 2014 to 2015 survey are presented below and are 
based on the 160 dB (rms) criterion currently used for all cetaceans 
and pinnipeds. It is assumed that marine mammals exposed to airgun 
sounds that strong could change their behavior sufficiently to be 
considered ``taken by harassment.'' Table 4 shows the density estimates 
calculated as described above and the estimates of the number of 
different individual marine mammals that potentially could be exposed 
to greater than or equal to 160 dB (rms) during the seismic survey if 
no animals moved away from the survey vessel. The requested take 
authorization is given in the middle (fourth from the left) column of 
Table 4. For species for which densities were unavailable as described 
above, but for which there were Ocean Biogeographic Information System 
(OBIS) sightings within or adjacent to the proposed study area, USGS 
has

[[Page 35668]]

included a requested take authorization for the mean group size for the 
species.
    It should be noted that unlike previous USGS, NSF, and L-DEO 
seismic surveys aboard the Langseth, the proposed survey would be 
conducted as almost one continuous line. Therefore, the ensonified area 
for the proposed seismic survey does not include a contingency factor 
(typically increased 25% to accommodate turns, lines that may need to 
be repeated, equipment testing, etc.) in line-kilometers. As typical 
during offshore ship surveys, inclement weather and equipment 
malfunctions are likely to cause delays and may limit the number of 
useful line-kilometers of seismic operations that can be undertaken. 
Also, any marine mammal sightings within or near the designated 
exclusion zones would result in a power-down and/or shut-down of 
seismic operations as a mitigation measure. Thus, the following 
estimates of the numbers of marine mammals potentially exposed to 160 
dB (rms) sounds are precautionary and probably overestimate the actual 
numbers of marine mammals that could be involved. These estimates 
assume that there would be no weather, equipment, or mitigation delays, 
which is highly unlikely.
    The number of different individuals that could be exposed to airgun 
sounds with received levels greater than or equal to 160 dB (rms) on 
one or more occasions can be estimated by considering the total marine 
area that would be within the 160 dB (rms) radius around the operating 
seismic source on at least one occasion, along with the expected 
density of animals in the area. The number of possible exposures 
(including repeated exposures of the same individuals) can be estimated 
by considering the total marine area that would be within the 160 dB 
radius around the operating airguns. In many seismic surveys, this 
total marine area includes overlap, as seismic surveys are often 
conducted in parallel survey lines where the ensonified areas of each 
survey line would overlap. The proposed tracklines in 2014 and 2015 
would not have overlap as the individual line segments do not run 
parallel to each other. The entire survey could be considered one 
continual survey line with slight turns (no more than 120 degrees) 
between each line segment. During the proposed seismic survey, the 
vessel would continue on the extensive survey line path, not staying 
within a smaller defined area as most seismic surveys often do. The 
numbers of different individuals potentially exposed to greater than or 
equal to 160 dB (rms) were calculated by multiplying the expected 
species density (for those marine mammal species that had density data 
available) times the total anticipated area to be ensonified to that 
level during airgun operations (3,165 km of survey lines). The total 
area expected to be ensonified was determined by multiplying the total 
trackline distance (3,165 km times the width of the swath of the 160 dB 
buffer zone (2 times 5.78 km). Using this approach, a total of 36,600 
km\2\ (10,671 nmi\2\) would fall within the 160 dB isopleth throughout 
the proposed survey in 2014. The proposed survey in 2015 is expected to 
ensonify an almost identical area (to within 2%); therefore, the same 
ensonified area of 36,600 km\2\ (10,671 nmi\2\) was used for 
calculation purposes since the number of estimated takes would be very 
similar for each of the two years. The number of estimated takes for 
the proposed survey in 2015 may need to be seasonally adjusted if the 
activity takes place in the late spring or early summer. Because it is 
uncertain at this time whether the 2015 survey would be scheduled in 
the spring (March, April, and May) or summer (June, July, and August) 
months, estimated takes were calculated for both seasons. For purposes 
of conservatively estimating the number of takes, the higher density 
(for spring or summer) was used for each species since it is not known 
at this time which season the 2015 proposed survey would take place in 
the April to August 2015 timeframe. If the 2015 survey occurred in the 
spring rather than summer, the density data suggests that takes would 
likely be higher for only the humpback whale, beaked whales, and 
bottlenose dolphin, and takes would likely be fewer for nine species 
(i.e., sperm whale, short-finned and long-finned pilot whales, Atlantic 
spotted, pantropical spotted, striped, Clymene, short-beaked common, 
and Risso's dolphin), and unchanged for the remaining species.

Table 4--Estimated Densities of Marine Mammal Species and Estimates of Possible Numbers of Marine Mammals Exposed to Sound Levels >=160 dB During USGS's
           Proposed Seismic Survey in the Northwest Atlantic Ocean Off the Eastern Seaboard, August to September 2014 and April to August 2015
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Calculated take
                                                       authorization
                                                     2014/2015 [i.e.,                                                Approximate
                                    Density spring/      estimated        Requested take          Abundance         percentage of
                                   summer  (/km\2\) \1\      individuals     (includes increase    population/stock)       regional      Population trend \6\
                                                        exposed to       to average group            \4\          population/stock
                                                       sound levels          size) \3\                             (for requested
                                                       >=160 dB re 1                                                  take) \5\
                                                        [mu]Pa] \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mysticetes:
    North Atlantic right whale...                NA               0/0  3 + 3 = 6...........  455/455............         1.32/1.32  Increasing.
    Humpback whale...............       0.0010170/0              0/38  38 + 3 = 41.........  11,600/823.........         0.35/4.98  Increasing.
    Minke whale..................        0.0000350/               2/2  2 + 2 = 4...........  138,000/20,741.....     0.0014/0.0096  NA.
                                          0.0000360
    Bryde's whale................                NA               0/0  3 + 3 = 6...........  NA/NA..............             NA/NA  NA.
    Sei whale....................                NA               0/0  3 + 3 = 6...........  10,300/357.........         0.06/1.68  NA.
    Fin whale....................         0.000060/               3/3  3 + 3 = 6...........  26,500/3,522.......         0.02/0.17  NA.
                                           0.000610
    Blue whale...................                NA               0/0  2 + 2 = 4...........  855/440............         0.47/0.91  NA.
Odontocetes:
    Sperm whale..................        0.0019050/             83/83  83 + 83 = 166.......  13,190/2,288.......         1.26/7.26  NA.
                                          0.0022510
    Pygmy sperm whale............        0.0008850/             33/33  33 + 33 = 66........  NA/3,785...........           NA/1.74  NA.
                                           0.008970

[[Page 35669]]

 
    Dwarf sperm whale............        0.0008850/             33/33  33 + 33 = 66........  NA/3,785...........           NA/1.74  NA.
                                          0.0008970
    Northern bottlenose whale....                NA               0/0  2 + 2 = 4...........  40,000/NA..........           0.01/NA  NA.
    Cuvier's beaked whale........        0.0021370/             84/84  84 + 84 = 168.......  NA/6,532...........           NA/1.29  NA.
                                          0.0022870
    Mesoplodon spp. (i.e.,         ................  ................  ....................  NA/7,092...........           NA/2.37  NA.
     True's, Gervais', Sowerby's,
     and Blainville's beaked
     whale.
    Bottlenose dolphin...........        0.0069560/           244/255  244 + 255 = 499.....  NA/77,532..........           NA/0.64  NA.
                                          0.0066470
    Atlantic white-sided dolphin.                NA               0/0  54 + 54 = 108.......  10,000 to 100,000s/         1.08/0.22  NA.
                                                                                              48,819.
    Fraser's dolphin.............                NA               0/0  100 + 100 = 200.....  NA/NA..............             NA/NA  NA.
    Atlantic spotted dolphin.....        0.0285700/       1,056/1,056  1,056 + 1,056 =       NA/44,715..........           NA/4.72  NA.
                                          0.0288400                     2,112.
    Pantropical spotted dolphin..        0.0194900/           724/724  724 + 724 = 1,448...  NA/3,333...........          NA/43.44  NA.
                                          0.0197600
    Striped dolphin..............        0.1330000/       4,916/4,916  4,916 + 4,916 =       NA/54,807..........          NA/17.94  NA.
                                          0.1343000                     9,832.
    Spinner dolphin..............                NA               0/0  65 + 65 = 130.......  NA/NA..............             NA/NA  NA.
    Clymene dolphin..............       0.0093110/0             0/341  70 + 341 = 411......  NA/NA..............             NA/NA  NA.
    Short-beaked common dolphin..        0.0053940/           203/203  203 + 203 = 406.....  NA/173,486.........           NA/0.23  NA.
                                          0.0055320
    Rough-toothed dolphin........         0.004200/             16/16  16 + 16 = 32........  NA/271.............          NA/11.81  NA.
                                          0.0004260
    Risso's dolphin..............        0.0092150/           342/342  342 + 342 = 684.....  NA/18,250..........           NA/3.75  NA.
                                          0.0093180
    Melon-headed whale...........                NA               0/0  100 + 100 = 200.....  NA/NA..............             NA/NA  NA.
    Pygmy killer whale...........                NA               0/0  25 + 25 = 50........  NA/NA..............             NA/NA  NA.
    False killer whale...........                NA               0/0  15 + 15 = 30........  NA/NA..............             NA/NA  NA.
    Killer whale.................                NA               0/0  7 + 7 = 14..........  NA/NA..............             NA/NA  NA.
    Short-finned pilot whale.....        0.0108000/           697/697  697 + 697 = 1,394...  780,000/21,515.....         0.18/6.48  NA.
                                          0.0190400
    Long-finned pilot whale......        0.0108000/           697/697  697 + 697 = 1,394...  780,000/26,535.....         0.18/5.25  NA.
                                          0.0190400
    Harbor porpoise..............                NA               0/0  5 + 5 = 10..........  500,000/79,883.....        0.002/0.01  NA.
Pinnipeds:
    Harbor seal..................                NA               0/0  0 + 0 = 0...........  NA/70,142..........             NA/NA  NA.
    Gray seal....................                NA               0/0  0 + 0 = 0...........  NA/331,000.........             NA/NA  Increasing.
    Harp seal....................                NA               0/0  0 + 0 = 0...........  8.6 to 9.6 million/             NA/NA  NA.
                                                                                              7.1 million.
    Hooded seal..................                NA               0/0  0 + 0 = 0...........  600,000/592,100....             NA/NA  NA.
--------------------------------------------------------------------------------------------------------------------------------------------------------
NA = Not available or not assessed.
\1\ OBIS-SERDP-Navy NODE 2007a and 2007b (for those species where density data is available).
\2\ Calculated take is estimated density multiplied by the 160 dB ensonified area.
\3\ Requested take authorization was increased to group size for species for which densities were not available but that have been sighted near the
  proposed survey area (CeTAP, 1984).
\4\ Stock sizes are best populations from NMFS Stock Assessment Reports where available (see Table 2 in above).
\5\ Requested takes expressed as percentages of the larger regional population and NMFS Stock Assessment Reports, where available.
\6\ Based on NMFS Stock Assessment Reports.

    Applying the approach described above, approximately 36,600 km\2\ 
would be within the 160 dB isopleth on one or more occasions during the 
proposed survey in 2014. The proposed survey in 2015 is expected to 
ensonify an almost identical area (to within 2%); therefore an 
ensonified area of 36,600 km\2\ was used for the proposed surveys in 
2014

[[Page 35670]]

and 2015. Because this approach does not allow for turnover in the 
marine mammal populations in the area during the course of the survey, 
the actual number of individuals exposed may be underestimated, 
although the conservative (i.e., probably overestimated) line-kilometer 
distances used to calculate the area may offset this. Also, the 
approach assumes that no cetaceans and pinnipeds would move away or 
toward the trackline as the Langseth approaches in response to 
increasing sound levels before the levels reach 160 dB (rms). Another 
way of interpreting the estimates that follow is that they represent 
the number of individuals that are expected (in the absence of a 
seismic program) to occur in the waters that would be exposed to 
greater than or equal to 160 dB (rms).

Encouraging and Coordinating Research

    USGS would coordinate the planned marine mammal monitoring program 
associated with the seismic survey with other parties that may have 
interest in this area and specified activity. USGS would coordinate 
with applicable U.S. agencies (e.g., NMFS), and would comply with their 
requirements.

Impact on Availability of Affected Species or Stock for Taking for 
Subsistence Uses

    Section 101(a)(5)(D) of the MMPA also requires NMFS to determine 
that the authorization would not have an unmitigable adverse effect on 
the availability of marine mammal species or stocks for subsistence 
use. There are no relevant subsistence uses of marine mammals 
implicated by this action. Therefore, NMFS has determined that the 
total taking of affected species or stocks would not have an 
unmitigable adverse impact on the availability of such species or 
stocks for taking for subsistence purposes.
Analyses and Preliminary 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). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of Level B harassment takes 
alone is not enough information on which to base an impact 
determination. In addition to considering estimates of the number of 
marine mammals that might be ``taken'' through behavioral harassment, 
NMFS must consider other factors, such as the likely nature of any 
responses (their intensity, duration, etc.), the context of any 
responses (critical reproductive time or location, migration, etc.), as 
well as the number and nature of estimated Level A harassment takes, 
the number of estimated mortalities, and effects on habitat.
    In making a negligible impact determination, NMFS evaluated factors 
such as:
    (1) The number of anticipated injuries, serious injuries, or 
mortalities;
    (2) The number, nature, and intensity, and duration of Level B 
harassment (all relatively limited); and
    (3) The context in which the takes occur (i.e., impacts to areas of 
significance, impacts to local populations, and cumulative impacts when 
taking into account successive/contemporaneous actions when added to 
baseline data);
    (4) 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);
    (5) Impacts on habitat affecting rates of recruitment/survival; and
    (6) The effectiveness of monitoring and mitigation measures.
    As described above and based on the following factors, the 
specified activities associated with the marine seismic survey are not 
likely to cause PTS, or other non-auditory injury, serious injury, or 
death. The factors include:
    (1) The likelihood that, given sufficient notice through relatively 
slow ship speed, marine mammals are expected to move away from a noise 
source that is annoying prior to its becoming potentially injurious;
    (2) 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;
    (3) The potential for temporary or permanent hearing impairment is 
relatively low and would likely be avoided through the implementation 
of the required monitoring and mitigation measures (including power-
down and shut-down measures); and
    (4) The likelihood that marine mammal detection ability by trained 
PSOs is high at close proximity to the vessel.
    Table 4 of this document outlines the number of requested Level B 
harassment takes that are anticipated as a result of these activities. 
The type of Level B (behavioral) harassment that could result from the 
proposed action are described in the ``Potential Effects of the 
Specified Activity on Marine Mammals'' section above, and include 
tolerance, masking, behavioral disturbance, TTS, PTS, and non-auditory 
or physiological effects.
    For the marine mammal species that may occur within the proposed 
action area, there are no known designated or important feeding and/or 
reproductive areas. Many animals perform vital functions, such as 
feeding, resting, traveling, and socializing, on a diel cycle (i.e., 24 
hr 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 
seismic operations are anticipated to occur on consecutive days, the 
estimated duration of the survey would last no more than a total of 36 
days (a 17 to 18 day leg in August to September 2014 and a 17 to 18 day 
leg in April to August 2015). Additionally, the seismic survey would be 
increasing sound levels in the marine environment in a relatively small 
area surrounding the vessel (compared to the range of the animals). The 
seismic surveys would not take place in areas of significance for 
marine mammal feeding, resting, breeding, or calving and would not 
adversely impact marine mammal habitat. Furthermore, the vessel would 
be constantly travelling over distances, and some animals may only be 
exposed to and harassed by sound for less than a day.
    NMFS's practice has been to apply the 160 dB re 1 [micro]Pa (rms) 
received level threshold for underwater impulse sound levels to 
determine whether take by Level B harassment occurs. Southall et al. 
(2007) provide a severity scale for ranking observed behavioral 
responses of both free-ranging marine mammals and laboratory subjects 
to various types of anthropogenic sound (see Table 4 in Southall et al. 
[2007]). NMFS has preliminarily determined, provided that the 
aforementioned mitigation and monitoring measures are implemented, the 
impact of conducting a marine seismic survey in the northwest Atlantic 
Ocean off of the Eastern Seaboard, August to September 2014 and April 
to August 2015, may result, at worst, in a modification in behavior 
and/or low-level physiological effects (Level B harassment) of certain 
species of marine mammals. No injuries, serious injuries, or 
mortalities are anticipated to occur as a result of USGS's planned 
marine seismic survey, and none are proposed to be authorized by NMFS.

[[Page 35671]]

    While behavioral modifications, including temporarily vacating the 
area during the operation of the airgun(s), may be made by these 
species to avoid the resultant acoustic disturbance, the availability 
of alternate areas within these areas for species and the short and 
sporadic duration of the research activities, have led NMFS to 
preliminary determine that the taking by Level B harassment from the 
specified activity would have a negligible impact on the affected 
species in the specified geographic region. Due to the nature, degree, 
and context of Level B (behavioral) harassment anticipated and 
described (see ``Potential Effects on Marine Mammals'' section above) 
in this notice, the activity is not expected to impact rates of annual 
recruitment or survival for any affected species or stock, particularly 
given the NMFS and the applicant's proposal to implement mitigation and 
monitoring measures that would minimize impacts to marine mammals. 
Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from USGS's proposed marine seismic survey would have a 
negligible impact on the affected marine mammal species or stocks.

Small Numbers

    As mentioned previously, NMFS estimates that 34 species of marine 
mammals under its jurisdiction could be potentially affected by Level B 
harassment over the course of the IHA. The population estimates for the 
marine mammal species that may be taken by Level B harassment are 
provided in Table 4 of this document. No takes of pinnipeds are 
expected due to a lack of species observations within the proposed 
study area, the great distance offshore, and the deep water depths of 
the proposed study area. It should be noted that the stock populations 
for each marine mammal species in the NMFS Stock Assessment Reports are 
generally for species populations in U.S. waters, which may 
underestimate actual population sizes for species that have ranges that 
would include waters outside the U.S. EEZ.
    NMFS has regional population and/or stock abundance estimates for 
the northwest Atlantic Ocean for 26 of the species under its 
jurisdiction that could potentially be affected by Level B harassment 
over the course of the IHA. The estimate of the number of individual 
cetaceans by species for which NMFS has such data that could be exposed 
to seismic sounds with received levels greater than or equal to 160 dB 
re 1 [mu]Pa (rms) during the proposed survey in 2014 and 2015 is as 
follows: 6 North Atlantic right, 41 humpback, 4 minke, 6 sei, 6 fin, 4 
blue, and 166 sperm whales, which would represent 1.32/1.32, 0.353/
4.96, 0.0014/0.0096, 0.058/1.68, 0.02/0.17, 0.468/0.909, and 1.259/
7.255% of the affected regional populations/stocks, respectively. In 
addition, 4 northern bottlenose, 168 Cuvier's and Mesoplodon (i.e., 
True's, Gervais', Sowerby's, and Blainville's beaked whales), 66 dwarf 
sperm, and 66 pygmy sperm whales could be taken by Level B harassment 
during the proposed seismic survey, which would represent 0.01/unknown, 
unknown/1.286, unknown/2.369, unknown/1.744, and unknown/1.744% of the 
regional populations/stocks, respectively. Most of the cetaceans 
potentially taken by Level B harassment are delphinids; of the 
delphinids for which NMFS has regional population or stock abundance 
estimates for the northwest Atlantic Ocean, 499 bottlenose, 108 
Atlantic white-sided, 2,112 Atlantic spotted, 1,448 pantropical 
spotted, 9,832 striped, 406 short-beaked common, 32 rough-toothed, and 
684 Risso's dolphins could be taken by Level B harassment during the 
proposed seismic survey, which would represent unknown/0.644, 1.08/
0.221, unknown/4.723, unknown/43.444, unknown/17.939, unknown/0.234, 
unknown/11.808, and unknown/3.748% of the regional populations/stocks, 
respectively. Of the remaining species for which NMFS has regional 
population or stock abundance estimates for the northwest Atlantic 
Ocean, 1,394 short-finned and 1,394 long-finned pilot whales, and 10 
harbor porpoises could be taken by Level B harassment during the 
proposed seismic survey, which would represent 0.178/6.479, 0.178/
5.253, and 0.002/0.013% of the regional population/stocks, 
respectively.
    NMFS makes its small numbers determination on the numbers of marine 
mammals that would be taken relative to the populations of the affected 
species or stocks. NMFS calculates the number of animals as a 
percentage of the stock population for marine mammals in the U.S. EEZ. 
For USGS's proposed survey, approximately 80% in 2014 and 90% in 2015 
of the tracklines occur within International Waters (i.e., the high 
seas) and are outside of the U.S. EEZ; therefore, the regional 
population is more applicable for NMFS's small numbers determinations 
as most of the ensonified area and estimated takes are further than 200 
nmi from the U.S. coastline. The requested take estimates represented 
as a percentage of the stock in Table 4 (above) should be reduced to 
20% and 10% of the calculated levels based on the amount of activity 
(i.e., 80% and 90%) planned to occur outside of the U.S. EEZ in 2014 
and 2015. Using the approach of calculating the number of requested 
take estimates within the U.S. EEZ (20% in 2014 and 10% in 2015), the 
take estimates provided in the preceding paragraph should change as 
follows (rounding up): 2 North Atlantic right, 9 humpback, 2 minke, 2 
sei, 2 fin, 2 blue, and 26 sperm whales, which would represent 0.44, 
1.09, <0.01, 0.56, 0.06, 0.46, and 1.14% of the affected stocks, 
respectively; 26 Cuvier's and Mesoplodon (i.e., True's, Gervais', 
Sowerby's, and Blainville's beaked whales), 11 dwarf sperm, and 11 
pygmy sperm whales, which would represent 0.4, 0.37, 0.29, and 0.29% of 
the affected stocks, respectively; 75 bottlenose, 17 Atlantic white-
sided, 318 Atlantic spotted, 218 pantropical spotted, 1,476 striped, 62 
short-beaked common, 6 rough-toothed, and 104 Risso's dolphins could be 
taken by Level B harassment during the proposed seismic survey, which 
would represent 0.1, 0.04, 0.71, 6.54, 2.69, 0.04, 2.21, and 0.57% of 
the affected stocks, respectively; and 210 short-finned and 210 long-
finned pilot whales, and 2 harbor porpoises, which would represent 
0.98, 0.79, and <0.01% of the affected stocks, respectively. No takes 
of pinnipeds are expected within the proposed study area. The requested 
take estimates represent a small number relative to the affected 
species' with a known regional population or stock size (i.e., all for 
which data are available are less than 6.54% of the regional 
populations).
    No known current regional population or stock abundance estimates 
for the northwest Atlantic Ocean are available for the eight remaining 
species under NMFS's jurisdiction that could potentially be affected by 
Level B harassment over the course of the IHA. These species include 
the Bryde's whale, Fraser's, spinner, and Clymene dolphins, and the 
melon-headed, pygmy killer, false killer, and killer whales. Therefore, 
NMFS is using older abundance estimates or abundance estimates from 
other areas such as the northern Gulf of Mexico stock, regional ocean 
basins (e.g., eastern tropical Pacific Ocean), or global summation to 
aid its small numbers determination for these species. These

[[Page 35672]]

abundance estimates are considered the best available information.
    Bryde's whales are distributed worldwide in tropical and sub-
tropical waters and their occurrence in the proposed study area is 
rare. In the western North Atlantic Ocean, Bryde's whales are reported 
from off the southeastern U.S. and southern West Indies to Cabo Frio, 
Brazil (Leatherwood and Reeves, 1983). No stock of Bryde's whales has 
been identified in U.S. waters off the Atlantic coast. The northern 
Gulf of Mexico population is considered a separate stock and has a best 
abundance estimate of 33 animals. In addition, there are estimated to 
be 20,000 to 30,000 animals in the North Pacific Ocean. Based on all of 
these factors, NMFS finds that the requested take estimate of 6 Bryde's 
whales represents a small number relative to the affected species' 
population size.
    Fraser's dolphins are distributed worldwide in tropical waters and 
their occurrence in the proposed study area is rare. There is no 
abundance estimates for either the western North Atlantic or the 
northern Gulf of Mexico stocks. The western North Atlantic population 
is provisionally being considered a separate stock for management 
purposes, although there is currently no information to differentiate 
this stock from the northern Gulf of Mexico stock. The numbers of 
Fraser's dolphins off the U.S. or Canadian Atlantic coast are unknown, 
and seasonal abundance estimates are not available for this stock, 
since it is rarely seen in any surveys. The population size for 
Fraser's dolphins is unknown; however, about 289,000 animals occur in 
the eastern tropical Pacific Ocean (Jefferson et al., 2008). The 
estimated number of requested takes for 200 Fraser's dolphins 
represents 0.06% of the eastern tropical Pacific Ocean population. 
Fraser's dolphins are distributed worldwide in tropical waters and 
their occurrence in the proposed study area is rare. Based on all these 
factors, NMFS finds that the requested take estimate represents a small 
number relative to the affected species' population size.
    Spinner dolphins are found in all tropical and sub-tropical oceans 
and their occurrence in the proposed study area is rare. The western 
North Atlantic population of spinner dolphins is provisionally being 
considered a separate stock for management purposes, although there is 
currently no information to differentiate this stock from the northern 
Gulf of Mexico stock. The numbers of spinner dolphins off the U.S. or 
Canadian Atlantic coast are unknown, and seasonal abundance estimates 
are not available for this stock since it was rarely seen in any of the 
surveys. The best abundance estimate available for northern Gulf of 
Mexico spinner dolphins is 11,441 animals. The estimated number of 
requested takes of 130 spinner dolphins represents 1.13% of the 
northern Gulf of Mexico stock. Based on all of these factors, NMFS 
finds that the requested take estimates represents a small number 
relative to the affected species' population size.
    The Clymene dolphin is endemic to tropical and sub-tropical waters 
of the Atlantic, including the Caribbean Sea and Gulf of Mexico 
(Jefferson and Curry, 2003; Jefferson et al., 2008). This species 
prefer warm waters and records extend from southern Brazil and Angola 
and north to Mauritania and New Jersey off the U.S. east coast 
(Jefferson et al., 2008). Their occurrence in the proposed study area 
is rare. The abundance estimate for the Clymene dolphin in the western 
North Atlantic was 6,086 in 203; this estimate is older than eight 
years and is considered unreliable (Wade and Angliss, 1997; Mullin and 
Fulling, 2003). However, this abundance estimate is the first and only 
estimate to date for this species in the U.S. Atlantic EEZ and 
represents the best abundance estimate. The estimated numbers of 
requested takes of 411 Clymene dolphins represent 6.75% of the western 
North Atlantic 2003 stock or 318.6% of the northern Gulf of Mexico 
stock. Based on all of these factors, NMFS finds that the requested 
take estimate represents a small number relative to the affected 
species' population or stock size.
    Melon-headed whales are distributed worldwide in tropical to sub-
tropical waters and their occurrence in the proposed study area is 
rare. The western North Atlantic population is provisionally being 
considered a separate stock from the northern Gulf of Mexico stock, 
although there is currently no information to differentiate this stock 
from the northern Gulf of Mexico stock. The numbers of melon-headed 
whales off the U.S. or Canadian Atlantic coast are unknown, and 
seasonal abundance estimates are not available for this stock, since it 
was rarely seen in any surveys. The best abundance estimate available 
for northern Gulf of Mexico melon-headed whales is 2,235 animals. The 
estimated number of requested takes of 200 melon-headed whales 
represents 8.94% of the northern Gulf of Mexico stock. Based on all of 
these factors, NMFS finds that the requested take estimate represents a 
small number relative to the affected species' population or stock 
size.
    The pygmy killer whale is distributed worldwide in tropical to sub-
tropical waters and their occurrence in the proposed study area is 
rare. The western North Atlantic population of pygmy killer whales is 
provisionally being considered one stock for management purposes. The 
numbers of pygmy killer whales off the U.S. or Canadian Atlantic coast 
are unknown, and seasonal abundance estimates are not available for 
this stock, since it was rarely seen in any surveys. The best abundance 
estimate available for the northern Gulf of Mexico pygmy killer whale 
is 152 animals. In addition, there are estimated to be 39,000 pygmy 
killer whales in the eastern tropical Pacific Ocean. The estimated 
number of requested takes of 50 pygmy killer whales represents 32.89% 
of the northern Gulf of Mexico stock, and 0.13% of the eastern tropical 
Pacific Ocean. Based on all of these factors, NMFS finds that the 
requested take estimate represents a small number relative to the 
affected species' population or stock size.
    The false killer whale is distributed worldwide throughout warm 
temperate and tropical oceans and their occurrence in the proposed 
study area is rare. No stock has been identified for false killer 
whales in U.S. waters off the Atlantic coast. The Gulf of Mexico 
population is provisionally being considered one stock for management 
purposes, although there is currently no information to differentiate 
this stock from the Atlantic Ocean stock. The current population size 
for the false killer whale in the northern Gulf of Mexico is unknown 
because they survey data is more than 8 years old; however, the most 
recent abundance estimate pooled from 2004 to 2004 was 777 animals 
(Wade and Angliss, 1997; Mullin, 2007). The estimated number of 
requested takes of 30 false killer whales represents 3.86% of the 
northern Gulf of Mexico stock. Based on all of these factors, NMFS 
finds that the requested take estimate represents a small number 
relative to the affected species' population or stock size.
    Killer whales are characterized as uncommon or rare in waters of 
the U.S. Atlantic EEZ (Katona et al., 1988). Their distribution extends 
from the Arctic ice-edge to the West Indies, often in offshore and mid-
ocean areas. There are estimated to be at least approximately 92,500 
killer whales worldwide. The size of the western North Atlantic stock 
population off the eastern U.S. coast is unknown. The northern Gulf of 
Mexico population is provisionally being considered a separate stock 
for management purposes, although there is currently no information to 
differentiate

[[Page 35673]]

this stock from the Atlantic Ocean stock. The best abundance estimate 
available for northern Gulf of Mexico killer whales is 28 animals. The 
estimated number of requested takes of 14 killer whales represents 
0.02% of the worldwide population, and 50% of the northern Gulf of 
Mexico stock. Based on all of these factors, NMFS finds that the 
requested take estimate represents a small number relative to the 
affected species' population or stock size.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration of the implementation of the mitigation and monitoring 
measures, NMFS preliminarily finds that small numbers of marine mammals 
would be taken relative to the populations of the affected species or 
stocks. See Table 4 for the requested authorized take number of marine 
mammals.

Endangered Species Act

    Of the species of marine mammals that may occur in the proposed 
survey area, several are listed as endangered under the ESA, including 
the North Atlantic right, humpback, sei, fin, blue, and sperm whales. 
Under section 7 of the ESA, USGS has initiated formal consultation with 
the NMFS, Office of Protected Resources, Endangered Species Act 
Interagency Cooperation Division, on this proposed seismic survey. 
NMFS's Office of Protected Resources, Permits and Conservation 
Division, has initiated formal consultation under section 7 of the ESA 
with NMFS's Office of Protected Resources, Endangered Species Act 
Interagency Cooperation Division, to obtain a Biological Opinion 
evaluating the effects of issuing the IHA on threatened and endangered 
marine mammals and, if appropriate, authorizing incidental take. NMFS 
would conclude formal section 7 consultation prior to making a 
determination on whether or not to issue the IHA. If the IHA is issued, 
USGS, in addition to the mitigation and monitoring requirements 
included in the IHA, would be required to comply with the Terms and 
Conditions of the Incidental Take Statement corresponding to NMFS's 
Biological Opinion issued to both USGS and NMFS's Office of Protected 
Resources.

National Environmental Policy Act

    With USGS's complete application, USGS provided NMFS a ``Draft 
Environmental Assessment for Seismic Reflection Scientific Research 
Surveys During 2014 and 2015 in Support of Mapping the U.S. Atlantic 
Seaboard Extended Continental Margin and Investigating Tsunami 
Hazards,'' prepared by RPS Evan-Hamilton, Inc., in association with 
YOLO Environmental, Inc., GeoSpatial Strategy Group, and Ecology and 
Environment, Inc., on behalf of USGS. The EA analyzes the direct, 
indirect, and cumulative environmental impacts of the proposed 
specified activities on marine mammals including those listed as 
threatened or endangered under the ESA. Prior to making a final 
decision on the IHA application, NMFS would either prepare an 
independent EA, or, after review and evaluation of the USGS EA for 
consistency with the regulations published by the Council of 
Environmental Quality (CEQ) and NOAA Administrative Order 216-6, 
Environmental Review Procedures for Implementing the National 
Environmental Policy Act, adopt the EA and make a decision of whether 
or not to issue a Finding of No Significant Impact (FONSI).

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to USGS for conducting the high-energy marine seismic 
survey in the northeast Atlantic Ocean off the Eastern Seaboard, 
provided the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated. The proposed IHA language is provided 
below:
    The NMFS hereby authorizes the U.S. Geological Survey, Pacific 
Coastal and Marine Geology Science Center, Mail Stop 999, 345 
Middlefield Road, Menlo Park, California 94025, Lamont-Doherty Earth 
Observatory of Columbia University, P.O. Box 1000, 61 Route 9W, 
Palisades, New York 10964-8000, and National Science Foundation, 
Division of Ocean Sciences, 4201 Wilson Boulevard, Suite 725, 
Arlington, Virginia 22230 (herein referred to USGS) under section 
101(a)(5)(D) of the Marine Mammal Protection Act (MMPA) (16 U.S.C. 
1371(a)(5)(D)), to harass small numbers of marine mammals incidental to 
a high-energy marine geophysical (seismic) survey conducted by the R/V 
Marcus G. Langseth (Langseth) in the northeast Atlantic Ocean off the 
Eastern Seaboard, August to September 2014 and April to August 2015:
    1. This Authorization is valid from August 15, 2014 through August 
14, 2015.
    2. This Authorization is valid only for the Langseth's specified 
activities associated with seismic survey operations as described in 
USGS's IHA application and ``Draft Environmental Assessment for Seismic 
Reflection Scientific Surveys During 2014 and 2015 in Support of 
Mapping the U.S. Atlantic Seaboard Extended Continental Margin and 
Investigating Tsunami Hazards'' that shall occur in the following 
specified geographic area (bounded by the following geographical 
coordinates):

40.5694[deg] North, -66.5324[deg] West;
38.5808[deg] North, -61.7105[deg] West;
29.2456[deg] North, -72.6766[deg] West;
33.1752[deg] North, -75.8697[deg] West;
39.1583[deg] North, -72.8697[deg] West;

    The proposed activities for 2014 will generally occur within the 
outer portions of the study area. The proposed activities for 2015 will 
in-fill more of the study area. Water depths range from approximately 
1,450 to 5,400 m (see Figure 1 and 2 of the IHA application); no survey 
lines will extend to water depths less than 1,000 m. The tracklines 
proposed for both 2014 and 2015 would be in International Waters 
(approximately 80% in 2014 and 90% in 2015) and in the U.S. EEZ, as 
specified in USGS's Incidental Harassment Authorization application and 
the associated USGS Environmental Assessment.
    3. Species Authorized and Level of Takes
    (a) The incidental taking of marine mammals, by Level B harassment 
only, is limited to the following species in the waters of the 
northeast Atlantic off the Eastern Seaboard:
    (i) Mysticetes--see Table 4 for authorized species and take 
numbers.
    (ii) Odontocetes--see Table 4 for authorized species and take 
numbers.
    (iii) If any marine mammal species are encountered during seismic 
activities that are not listed in Table 4 for authorized taking and are 
likely to be exposed to sound pressure levels (SPLs) greater than or 
equal to 160 dB re 1 [mu]Pa (rms), then the USGS must alter speed or 
course or shut-down the airguns to avoid take.
    (b) The taking by injury (Level A harassment), serious injury, or 
death of any of the species listed in Condition 3(a) above 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.
    4. The methods authorized for taking by Level B harassment are 
limited to the following acoustic sources without an amendment to this 
Authorization:
    (a) A 36 airgun array with a total volume of 6,600 cubic inches (in 
\3\) (or smaller);
    (b) A multi-beam echosounder; and
    (c) A sub-bottom profiler.

[[Page 35674]]

    5. The taking of any marine mammal in a manner prohibited under 
this Authorization must be reported immediately to the Office of 
Protected Resources, National Marine Fisheries Service (NMFS), at 301-
427-8401 and/or by email to noaa.gov">Jolie.Harrison@noaa.gov and 
noaa.gov">Howard.Goldstein@noaa.gov.
    6. Mitigation and Monitoring Requirements
    The USGS is required to implement the following mitigation and 
monitoring requirements when conducting the specified activities to 
achieve the least practicable impact on affected marine mammal species 
or stocks:
    (a) Utilize two, NMFS-qualified, vessel-based PSVO (except during 
meal times and restroom breaks, when at least one PSVO shall be on 
watch) to visually 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 ramp-ups 
of airguns day or night.
    (i) The Langseth's vessel crew shall also assist in detecting 
marine mammals, when practicable.
    (ii) PSVOs shall have access to reticle binoculars (7 x 50 
Fujinon), big-eye binoculars (25 x 150), optical range finders, and 
night vision devices.
    (iii) PSVO shifts shall last no longer than 4 hours at a time.
    (iv) When feasible, PSVOs shall also make observations during 
daytime periods when the seismic system is not operating for comparison 
of animal abundance and behavioral reactions during, between, and after 
airgun operations.
    (v) PSVOs shall conduct monitoring while the airgun array and 
streamer(s) are being deployed or recovered from the water.
    (b) PSVOs shall record the following information when a marine 
mammal is sighted:
    (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 Condition 6(c)(ii) shall also be 
recorded 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.
Passive Acoustic Monitoring
    (c) Utilize the 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 NMFS-qualified PSO and/or expert 
bioacoustician (i.e., PSAO) shall monitor the PAM at all times in 
shifts no longer than 6 hours. An expert bioacoustician shall design 
and set up the PAM system and be present to operate to oversee PAM, and 
available when technical issues occur during the survey.
    (d) Do and record the following when an animal is detected by the 
PAM:
    (i) Notify the on-duty PSVO(s) immediately of the presence of a 
vocalizing marine mammal so a power-down or shut-down can be initiated, 
if required:
    (ii) Enter the information regarding the vocalization into a 
database. The data to be entered include an acoustic encounter 
identification number, whether it was linked with a visual sighting, 
date, time when first and last heard and whenever any additional 
information was recorded, position, and water depth when first 
detected, bearing if determinable, species or species group (e.g., 
unidentified dolphin, sperm whale), types and nature of sounds heard 
(e.g., clicks, continuous, sporadic, whistles, creaks, burst pulses, 
strength of signal, etc.), and any other notable information. The 
acoustic detection can also be recorded for further analysis.
Buffer and Exclusion Zones
    (e) Establish a 160 dB re 1 [micro]Pa (rms) buffer zone as well as 
180 and 190 dB re 1 [micro]Pa (rms) exclusion zone for marine mammals 
before the 2-string airgun array (6,600 in\3\) is in operation; and a 
180 and 190 dB re 1 [micro]Pa (rms) exclusion zone before a single 
airgun (40 in\3\) is in operation, respectively. See Table 1 (above) 
for distances and exclusion zones.
Visual Monitoring at the Start of Airgun Operations
    (f) Visually observe the entire extent of the exclusion zone (180 
dB re 1 [mu]Pa [rms] for cetaceans; see Table 1 [above] for distances) 
using NMFS-qualified PSVOs, for at least 30 minutes prior to starting 
the airgun array (day or night).
    (i) If the PSVO observes a marine mammal within the exclusion zone, 
USGS must delay the seismic survey until the marine mammal(s) has left 
the area. If the PSVO sees a marine mammal that surfaces, then dives 
below the surface, the PSVO shall wait 30 minutes. If the PSVO sees no 
marine mammals during that time, he/she should assume that the animal 
has moved beyond the exclusion zone.
    (ii) If for any reason the entire radius cannot be seen for the 
entire 30 minutes (i.e., rough seas, fog, darkness), or if marine 
mammals are near, approaching, or within the exclusion zone, the 
airguns 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 (rms), USGS may start the second airgun, and 
subsequent airguns, without observing the entire exclusion zone for 30 
minutes prior, provided no marine mammals are known to be near the 
exclusion zone (in accordance with Condition 6[h] below).
Ramp-Up Procedures
    (g) Ramp-up procedures at the start of seismic operations or after 
a shut-down--Implement a ``ramp-up'' procedure when starting-up at the 
beginning of seismic operations or any time after the entire array has 
been shut-down for more than 10 minutes, which means starting with the 
smallest airgun first and adding airguns in a sequence such that the 
source level of the array shall increase in steps not exceeding 
approximately 6 dB per 5-minute period. During ramp-up, the PSVOs shall 
monitor the 180 and 190 dB exclusion zone for cetaceans and pinnipeds, 
respectively, and if marine mammals are sighted within or about to 
enter the relevant exclusion zone, a power-down, or shut-down shall be 
implemented as though the full array were operational. Therefore, 
initiation of ramp-up procedures from a shut-down or at the beginning 
of seismic operations requires that the PSVOs be able to view the full 
exclusion zone as described in Condition 6(m) (below).
Power-Down Procedures
    (h) Power-down the airgun(s) if a marine mammal is detected within, 
approaches, or enters the relevant exclusion zone (as defined in Table 
1, above). A power-down means reducing the number of operating airguns 
to a single operating 40 in\3\ airgun, which reduces the exclusion zone 
to the degree that the animal(s) is no longer in or about to enter it 
for the full airgun array. When appropriate or possible, power-down of 
the airgun array shall also occur when the vessel is moving from the 
end of one trackline to the start of the next trackline.
    (i) Following a power-down, if the marine mammal approaches the 
small

[[Page 35675]]

designated exclusion zone, the airguns must then be completely shut-
down. Airgun activity shall not resume until the PSVO 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).
    (j) Following a power-down and subsequent animal departure, the 
airgun operations may resume at full power. Initiation requires that 
PSVOs can effectively monitor the full exclusion zones described 
Condition 6(g). If the PSVO(s) sees a marine mammal within or about to 
enter the relevant zones, when a course/speed alteration, power-down, 
or shut-down will be implemented.
Shut-Down Procedures
    (k) Shut-down the airgun(s) if a marine mammal is detected within, 
approaches, or enters the relevant exclusion zone (as defined in Table 
1, above). A shut-down means all operating airguns are shut-down (i.e., 
turned off).
    (l) Following a shut-down, if the PSVO has visually confirmed that 
the animal has departed the relevant exclusion zone (and is not likely 
to return) within a period less than or equal to 10 minutes after the 
shut-down, the airgun operations may resume at full power. If the PSVO 
has not observed the marine mammal(s) exiting the exclusion zone, the 
airgun operations shall not resume 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). Following 
a shut-down, the Langseth may resume following ramp-up procedures 
described in Condition 6(h).
Speed or Course Alteration
    (m) 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, further mitigation 
measures, such as a power-down or shut-down, shall be taken.
Survey Operations at Night
    (n) Marine seismic surveys may continue into night and low-light 
hours if such segment(s) of the survey is initiated when the entire 
relevant exclusion zones are visible and can be effectively monitored.
    (o) No initiation of airgun array operations is permitted from a 
shut-down position at night or during low-light hours (such as in dense 
fog or heavy rain) when the entire relevant exclusion zone cannot be 
effectively monitored by the PSO(s) on duty.
Mitigation Airgun
    (p) Use of small-volume airgun (i.e., mitigation airgun) during 
turns and maintenance shall be operated at approximately one shot per 
minute and would not be operated for longer than three hours in 
duration. During turns or brief transits between seismic tracklines, 
one airgun will continue operating.
Special Procedures for Situations or Species of Concern
    (q) If a North Atlantic right whale (Eubalaena glacialis) is 
visually sighted, the airgun array shall be shut-down regardless of the 
distance of the animal(s) to the sound source. The array shall not 
resume firing until 30 minutes after the last documented whale visual 
sighting.
    (r) Concentrations of humpback (Megaptera novaeangliae), sei 
(Balaenoptera borealis), fin (Balaenoptera physalus), blue 
(Balaenoptera musculus), and/or sperm whales (Physeter macrocephalus) 
will be avoided if possible (i.e., exposing concentrations of animals 
to 160 dB), and the array will be powered-down if necessary. 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.).
7. Reporting Requirements
    The USGS is required to:
    (a) Submit a draft comprehensive report on all activities and 
monitoring results to the Office of Protected Resources, NMFS, within 
90 days of the completion of the Langseth's cruise in the northwest 
Atlantic Ocean off the Eastern Seaboard after the end of phase 1 in 
2014 and another draft comprehensive report after the end of phase 2 in 
2015. 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 power-downs and shut-downs), observed throughout all 
monitoring activities.
    (iii) An estimate of the number (by species) of marine mammals 
that: (A) Are known to have been exposed to the seismic activity (based 
on visual observation) at received levels greater than or equal to 160 
dB re 1 [mu]Pa (rms) and/or 180 dB re 1 [mu]Pa (rms) for cetaceans and 
190 dB re 1 [mu]Pa (rms) for pinnipeds with a discussion of any 
specific behaviors those individuals exhibited; and (B) may have been 
exposed (based on modeled values for the 36 airgun array) to the 
seismic activity at received levels greater than or equal to 160 dB re 
1 [mu]Pa (rms) and/or 180 dB re 1 [mu]Pa (rms) for cetaceans and 190 dB 
re 1 [mu]Pa (rms) for pinnipeds with a discussion of the nature of the 
probable consequences of that exposure on the individuals that have 
been exposed.
    (iv) A description of the implementation and effectiveness of the: 
(A) Terms and Conditions of the Biological Opinion's Incidental Take 
Statement (ITS); and (B) mitigation measures of the Incidental 
Harassment Authorization. For the Biological Opinion, the report shall 
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, NMFS, within 30 days after 
receiving comments from NMFS on the draft report. If NMFS decides that 
the draft report needs no comments, the draft report shall be 
considered to be the final report.
Reporting Prohibited Take
    8. In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by this 
Authorization (if issued), such as an injury (Level A harassment), 
serious injury, or mortality (e.g., ship-strike, gear interaction, and/
or entanglement), USGS shall immediately cease the specified activities 
and immediately report the incident to the Chief of the Permits and 
Conservation Division, Office of Protected Resources, NMFS, at 301-427-
8401 and/or by email to noaa.gov">Jolie.Harrison@noaa.gov and

[[Page 35676]]

noaa.gov">Howard.Goldstein@noaa.gov and the NMFS Greater Atlantic Region Marine 
Mammal Stranding Network at 866-755-6622 (noaa.gov">Mendy.Garron@noaa.gov), and 
NMFS Southeast Region Marine Mammal Stranding Network at 877-433-8299 
(noaa.gov">Blair.Mase@noaa.gov and noaa.gov">Erin.Fougeres@noaa.gov). The report must 
include the following information:
    (a) Time, date, and location (latitude/longitude) of the incident; 
the name and type of vessel involved; the 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 marine mammal 
observations in the 24 hours preceding the incident; species 
identification or description of the animal(s) involved; the fate of 
the animal(s); and photographs or video footage of the animal (if 
equipment is available).
    USGS shall not resume its activities until NMFS is able to review 
the circumstances of the prohibited take. NMFS shall work with USGS to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. USGS may not resume their 
activities until notified by NMFS via letter, email, or telephone.
Reporting an Injured or Dead Marine Mammal With an Unknown Cause of 
Death
    In the event that USGS discovers an injured or dead marine mammal, 
and the lead PSO determines that the cause of the injury or death is 
unknown and the death is relatively recent (i.e., in less than a 
moderate state of decomposition as described in the next paragraph), 
USGS will immediately report the incident to the Chief of the Permits 
and Conservation Division, Office of Protected Resources, NMFS, at 301-
427-8401, and/or by email to noaa.gov">Jolie.Harrison@noaa.gov and 
noaa.gov">Howard.Goldstein@noaa.gov, and the NMFS Greater Atlantic Region Marine 
Mammal Stranding Network (866-755-6622) and/or by email to the NMFS 
Greater Atlantic Regional Stranding Coordinator 
(noaa.gov">Mendy.Garron@noaa.gov), and the NMFS Southeast Region Marine Mammal 
Stranding Network (877-433-8299) and/or by email to the Southeast 
Regional Stranding Coordinator (noaa.gov">Blair.Mase@noaa.gov) and Southeast 
Regional Stranding Program Administrator (noaa.gov">Erin.Fougeres@noaa.gov). The 
report must include the same information identified in Condition 8(a) 
above. Activities may continue while NMFS reviews the circumstances of 
the incident. NMFS will work with USGS to determine whether 
modifications in the activities are appropriate.
Reporting an Injured or Dead Marine Mammal Not Related to the 
Activities
    In the event that USGS discovers an injured or dead marine mammal, 
and the lead PSO determines that the injury or death is not associated 
with or related to the activities authorized in Condition 2 of this 
Authorization (e.g., previously wounded animal, carcass with moderate 
to advanced decomposition, or scavenger damage), USGS shall report the 
incident to the Chief of the Permits and Conservation Division, Office 
of Protected Resources, NMFS, at 301-427-8401, and/or by email to 
noaa.gov">Jolie.Harrison@noaa.gov and noaa.gov">Howard.Goldstein@noaa.gov, and the NMFS 
Greater Atlantic Marine Mammal Stranding Network (866-755-622), and/or 
by email to the Greater Atlantic Regional Stranding Coordinator 
(noaa.gov">Mendy.Garron@noaa.gov), and the NMFS Southeast Regional Stranding 
Network (877-433-8299), and/or by email to the Southeast Stranding 
Coordinator (noaa.gov">Blair.Mase@noaa.gov) and Southeast Regional Stranding 
Program Administrator (noaa.gov">Erin.Fourgeres@noaa.gov), within 24 hours of the 
discovery. USGS shall provide photographs or video footage (if 
available) or other documentation of the stranded animal sighting to 
NMFS and the Marine Mammal Stranding Network. Activities may continue 
while NMFS reviews the circumstances of the incident.
Endangered Species Act (ESA) Biological Opinion and Incidental Take 
Statement (ITS)
    9. USGS is required to comply with the Terms and Conditions of the 
ITS corresponding to NMFS's ESA Biological Opinion issued to both USGS 
and NMFS's Office of Protected Resources, Permits and Conservation 
Division.
    10. A copy of this Authorization and the ITS must be in the 
possession of all contractors and PSOs operating under the authority of 
this Incidental Harassment Authorization.

Request for Public Comments

    NMFS requests comments on our analysis, the draft authorization, 
and any other aspect of the notice of proposed IHA for USGS's proposed 
marine seismic survey in the Atlantic Ocean off the Eastern Seaboard. 
Please include with your comments any supporting data or literature 
citations to help inform our final decision on USGS's request for an 
MMPA authorization. Concurrent with the publication of this notice in 
the Federal Register, NMFS is forwarding copies of this application to 
the Marine Mammal Commission and its Committee of Scientific Advisors.

    Dated: June 16, 2014.
Perry F. Gayaldo,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2014-14426 Filed 6-20-14; 8:45 am]
BILLING CODE 3510-22-P