[Federal Register Volume 79, Number 2 (Friday, January 3, 2014)]
[Notices]
[Pages 464-497]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-31471]



[[Page 463]]

Vol. 79

Friday,

No. 2

January 3, 2014

Part III





Department of Commerce





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 National Oceanic and Atmospheric Administration





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 Takes of Marine Mammals Incidental to Specified Activities; Low-Energy 
Marine Geophysical Survey in the Dumont d'Urville Sea Off the Coast of 
East Antarctica, January to March 2013; Notice

  Federal Register / Vol. 79 , No. 2 / Friday, January 3, 2014 / 
Notices  

[[Page 464]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XC779


Takes of Marine Mammals Incidental to Specified Activities; Low-
Energy Marine Geophysical Survey in the Dumont d'Urville Sea Off the 
Coast of East Antarctica, January to March 2013

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 National Science 
Foundation (NSF) Division of Polar Programs, and Antarctic Support 
Contract (ASC) on behalf of five research institutions: Colgate 
University, Columbia University, Texas A&M Research Foundation, 
University of South Florida, and University of Texas at Austin, for an 
Incidental Harassment Authorization (IHA) to take marine mammals, by 
harassment, incidental to conducting a low-energy marine geophysical 
(seismic) survey in the Dumont d'Urville Sea off the coast of East 
Antarctica, January to March 2014. Pursuant to the Marine Mammal 
Protection Act (MMPA), NMFS is requesting comments on its proposal to 
issue an IHA to NSF to incidentally harass, by Level B harassment only, 
14 species of marine mammals during the specified activity.

DATES: Comments and information must be received no later than February 
3, 2014.

ADDRESSES: Comments on the application should be addressed to P. 
Michael Payne, Chief, Permits and Conservation Division, Office of 
Protected Resources, National Marine Fisheries Service, 1315 East-West 
Highway, Silver Spring, MD 20910. The mailbox address for providing 
email comments is [email protected]. NMFS is not responsible for 
email comments sent to addresses other than the one provided here. 
Comments sent via email, including all attachments, must not exceed a 
10-megabyte file size.
    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.
    A copy of the application containing a list of the references used 
in this document may be obtained by writing to the above address, 
telephoning the contact listed here (see FOR FURTHER INFORMATION 
CONTACT) or visiting the internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
    NSF and ASC have provided a ``Draft Initial Environmental 
Evaluation/Environmental Assessment to Conduct a Marine-Based Studies 
of the Totten Glacier System and Marine Record of Cryosphere--Ocean 
Dynamics'' (IEE/EA), prepared by AECOM, on behalf of NSF and ASC, 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)(D) of the MMPA, as amended (16 U.S.C. 1371 
(a)(5)(D)), directs the Secretary of Commerce (Secretary) to authorize, 
upon request, the incidental, but not intentional, taking of small 
numbers of marine mammals of a species or population stock, 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, if the taking is limited to harassment, a notice 
of a proposed authorization is provided to the public for review.
    Authorization for the incidental taking of small numbers of marine 
mammals 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). The authorization must 
set forth the permissible methods of taking, other means of effecting 
the least practicable adverse impact on the species or stock and its 
habitat, and requirements pertaining to the mitigation, monitoring and 
reporting of such takings. 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.''
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the United States can apply for an authorization 
to incidentally take small numbers of marine mammals by harassment. 
Section 101(a)(5)(D) of the MMPA establishes a 45-day time limit for 
NMFS's review of an application followed by a 30-day public notice and 
comment period on any proposed authorizations for the incidental 
harassment of small numbers of marine mammals. Within 45 days of the 
close of the public comment period, NMFS must either issue or deny the 
authorization.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment].

Summary of Request

    On July 3, 2013, NMFS received an application from the NSF and ASC 
requesting that NMFS issue an IHA for the take, by Level B harassment 
only, of small numbers of marine mammals incidental to conducting a 
low-energy marine seismic survey in International Waters (i.e., high 
seas) and in the Southern Ocean off the coast of East Antarctica during 
January to March 2014. We received an addendum to the application from 
the NSF and ASC on December 18, 2013 which reflected updates to 
incidental take requests for marine mammals related to icebreaking 
activities.
    The research would be conducted by five research institutions: 
Colgate University, Columbia University, Texas A&M Research Foundation, 
University of South Florida, and University of Texas at Austin. The NSF 
and ASC plans to use one source vessel, the R/VIB Nathaniel B. Palmer 
(Palmer), and a seismic airgun array to collect seismic data in the 
Southern Ocean. The vessel would be operated by ASC, which operates the 
United States Antarctic Program under contract to the NSF. In support 
of the United States Antarctic Program, the NSF and ASC plans to use 
conventional low-energy, seismic methodology to perform marine-based 
studies in the Dumont d'Urville Sea to include evaluation of 
geophysical and physical oceanographic features in two

[[Page 465]]

areas along the coast of East Antarctica (see Figures 1, 2, and 3 of 
the IHA application). The primary area proposed for the study is the 
Totten Glacier system (preferred study area) including the Moscow 
University Ice Shelf along the Sabrina Coast, and a secondary area, the 
Mertz Glacier and Cook Ice Shelf, along the Oates Coast. In addition to 
the proposed operations of the seismic airgun array and hydrophone 
streamer, NSF and ASC intend to operate a single-beam echosounder, 
multi-beam echosounder, acoustic Doppler current profiler (ADCP), and 
sub-bottom profiler continuously throughout the survey.
    Acoustic stimuli (i.e., increased underwater sound) generated 
during the operation of the seismic airgun array and from icebreaking 
activities may have the potential to cause a behavioral disturbance for 
marine mammals in the survey area. This is the principal means of 
marine mammal taking associated with these activities, and NSF and ASC 
has requested an authorization to take 14 species of marine mammals by 
Level B harassment. Take is not expected to result from the use of the 
single-beam echosounder, multi-beam echosounder, ADCP, acoustic 
locator, and sub-bottom profiler, as the brief exposure of marine 
mammals to one pulse, or small numbers of signals, in this particular 
case is not likely to result in the harassment of marine mammals. Also, 
NMFS does not expect take to result from collision with the source 
vessel because it is a single vessel moving at a relatively slow, 
constant cruise speed of 5 knots [kts]; 9.3 kilometers per hour [km/
hr]; 5.8 miles per hour [mph]) during seismic acquisition within the 
survey, for a relatively short period of time (approximately 45 
operational days). It is likely that any marine mammal would be able to 
avoid the vessel.

Description of the Proposed Specified Activity

    NSF and ASC propose to conduct a low-energy seismic survey in the 
Dumont d'Urville Sea in the Southern Ocean off the coast of East 
Antarctica from January to March 2014. In addition to the low-energy 
seismic survey, scientific activities would include conducting a 
bathymetric profile survey of the seafloor using transducer based 
instruments such as a multi-beam echosounder and sub-bottom profiler; 
conducting magnetometry and imaging surveys using an underwater camera 
assembly; collecting sediment cores and dredge sampling; and collecting 
water samples and conductivity (salinity), temperature, depth (CTD) and 
current data through the deployment and recovery of short-term (in 
place for approximately one month) and long-term (in place for 
approximately one year) instrumentation moorings, CTD equipment casts, 
and the use of transducer-based ADCP instruments. Sea ice conditions 
will dictate areas where the ship and airguns can operate. Due to 
dynamic ice conditions, which cannot be predicted on a local scale, it 
is not possible to develop tracklines a priori. The seismic survey 
would be conducted in one or both of the two study areas depending on 
the sea ice conditions; however, the preferred study area is the Totten 
Glacier region (see Figure 2 of the IHA application). Water depths in 
the survey area range from 100 to 1,000 meters (m) (328.1 to 3,280.1 
feet [ft]), and possibly exceeding 1,000 m in some areas. The seismic 
surveys are scheduled to occur for a total of less than or equal to 300 
hours at one or both of the two study areas for approximately 45 
operational days in January to March 2014. The operation hours and 
survey length would include equipment testing, ramp-up, line changes, 
and repeat coverage. The long transit time between port and the study 
site constrains how long the ship can be in the study area and 
effectively limits the maximum amount of time the airguns can operate. 
Some minor deviation from these dates would be possible, depending on 
logistics and weather.
    The proposed survey of Totten Glacier and Moscow University Ice 
Shelf along the Sabrina Coast continental shelf is designed to address 
several critical questions. The Totten Glacier system, which drains 
one-eighth of the East Antarctic Ice Sheet and contains more ice volume 
than the entire West Antarctic Ice Sheet, remains the single largest 
and least understood glacial system which possesses a potentially 
unsteady dynamic. If it were to melt, sea-level would rise by more than 
5 m (16.4 ft) worldwide. The proposed marine studies would help to 
understand both the dynamics and the controls of the Totten Glacier 
system, and to resolve ambiguity in large ice mass dynamic behavior. 
This research would be accomplished via the collection of 
glaciological, geological, and physical oceanographic data. In order to 
place the modern system, as well as more recent changes to the system, 
into a longer-term perspective, researchers would collect and interpret 
marine geologic, geochemical, and geophysical records of the longer 
term behavior and response of this system.
    The proposed research would complement fieldwork studying other 
Antarctic ice shelves oceanographic studies near the Antarctic 
Peninsula, and ongoing development of ice sheet and other ocean models. 
It would facilitate learning at sea and ashore by students, help to 
fill important spatial and temporal gaps in a sparsely sampled region 
of coastal Antarctica, and communicate its findings via publications 
and outreach. Obtaining records of currents and oceanographic 
properties in this region are consistent with the objectives of the 
Southern Ocean Observing System for climate change. The work would 
enhance general understanding of air-sea-ice interactions, ocean 
circulation, ice shelf sensitivity to climate change, and the present 
and future roles of East Antarctic Ice Sheet on sea level.
    The Principal Investigators are Dr. Amy Leventer of Colgate 
University, Dr. Donald Blankenship and Dr. Sean Gulick of the 
University of Texas at Austin, Dr. Eugene Domack of the University of 
South Florida, Mr. Bruce Huber of Columbia University, and Dr. 
Alejandro Orsi of Texas A&M Research Foundation.
    The procedures to be used for the surveys would be similar to those 
used during previous low-energy seismic surveys by NSF and would use 
conventional seismic methodology. The proposed survey will involve one 
source vessel, the R/V Nathaniel B. Palmer (Palmer). NSF and ASC will 
deploy two (each with a discharge volume of 45 cubic inch [in\3\] with 
a total volume of 90 in\3\ or each with a discharge volume of 105 in\3\ 
with a total volume of 210 in\3\) Sercel Generator Injector (GI) airgun 
array as an energy source at a tow depth of up to 3 m (9.8 ft) below 
the surface (more information on the airguns can be found in Appendix B 
of the IHA application). The receiving system will consist of one 100 m 
(328.1 ft) long, 24-channel, solid-state hydrophone streamer towed 
behind the vessel. As the GI airguns are towed along the survey lines, 
the hydrophone streamer will receive the returning acoustic signals and 
transfer the data to the onboard processing system. All planned seismic 
data acquisition activities will be conducted by technicians provided 
by NSF and ASC with onboard assistance by the scientists who have 
proposed the study. The vessel will be self-contained, and the crew 
will live aboard the vessel for the entire cruise.
    The planned seismic survey (e.g., equipment testing, start-up, line 
changes, repeat coverage of any areas, and equipment recovery) will 
consist of approximately 2,800 kilometer (km) (1,511.9 nautical miles 
[nmi]) of transect lines (including turns) in the survey area in the 
Dumont d'Urville Sea of the

[[Page 466]]

Southern Ocean (see Figures 1, 2, and 3 of the IHA application). In 
addition to the operation of the airgun array, a single-beam and multi-
beam echosounder, ADCP, and a sub-bottom profiler will also likely be 
operated from the Palmer continuously throughout the cruise between the 
first and last survey sites. There will be additional seismic 
operations associated with equipment testing, ramp-up, and possible 
line changes or repeat coverage of any areas where initial data quality 
is sub-standard. In NSF and ASC's estimated take calculations, 25% has 
been added for those additional operations.

    Table 1--Proposed Low-Energy Seismic Survey Activities in the Dumont d'Urville Sea Off the Coast of East
                                                   Antarctica
----------------------------------------------------------------------------------------------------------------
                                     Cumulative
       Survey length (km)          duration (hr)    Airgun array total  Time between airgun  Streamer length (m)
                                        \1\               volume          shots (distance)
----------------------------------------------------------------------------------------------------------------
2,800 (1,511.9 nmi).............           <=300   2 x 45 in\3\ (2 x    5 seconds (12.5 m    100 (328.1 ft).
                                                    737 cm\3\) or        or 41 ft).
                                                   2 x 105 in\3\ (2 x
                                                    1,720 cm\3\).
----------------------------------------------------------------------------------------------------------------
\1\ Airgun operations are planned for no more than 16 continuous hours at a time.

Vessel Specifications

    The Palmer, a research vessel owned by Edison Chouest Offshore, 
Inc. and operated by NSF and ACS (under a long-term charter with Edison 
Chouest Offshore, Inc.), will tow the two GI airgun array, as well as 
the hydrophone streamer. When the Palmer is towing the airgun array and 
the relatively short hydrophone streamer, the turning rate of the 
vessel while the gear is deployed is much higher than the limit of 5 
degrees per a minute for a seismic vessel towing a streamer of more 
typical length (much greater than 1 km [0.5 nmi]), which is 
approximately 20 degrees. Thus, the maneuverability of the vessel is 
not limited much during operations with the streamer.
    The U.S.-flagged vessel has a length of 94 m (308.5 ft); a beam of 
18.3 m (60 ft); a maximum draft of 6.8 m (22.5 ft); and a gross tonnage 
of 6,174. The ship is powered by four Caterpillar 3608 diesel engines 
(3,300 brake horsepower [hp] at 900 rotations per minute [rpm]) and a 
1,400 hp flush-mounted, water jet azimuthing bowthruster. Electrical 
power is provided by four Catepillar 3512, 1,050 kiloWatt (kW) diesel 
generators. The Palmer's operation speed during seismic acquisition is 
typically approximately 9.3 km/hr (5 kts) (varying between 7.4 to 11.1 
km/hr [4 to 6 kts]). When not towing seismic survey gear, the Palmer 
typically cruises at 18.7 km/hr (10.1 kts) and has a maximum speed of 
26.9 km/hr (14.5 kts). The Palmer has an operating range of 
approximately 27,780 km (15,000 nmi) (the distance the vessel can 
travel without refueling), which is approximately 70 to 75 days. The 
vessel can accommodate 37 scientists and 22 crew members.
    The vessel also has two locations as likely observation stations 
from which Protected Species Observers (PSO) will watch for marine 
mammals before and during the proposed airgun operations on the Palmer. 
Observing stations will be at the bridge level with PSO's eye level 
approximately 16.5 m (54.1 ft) above sea level with an approximately 
270[deg] view around the vessel, and an aloft observation tower that is 
approximately 24.4 m (80.1 ft) above sea level that is protected from 
the weather and has an approximately 360[deg] view around the vessel. 
More details of the Palmer can be found in the IHA application and 
online at: http://www.nsf.gov/geo/plr/support/nathpalm.jsp and http://www.usap.gov/vesselScienceAndOperations/contentHandler.cfm?id=1561.

Acoustic Source Specifications

Seismic Airguns

    The Palmer will deploy an airgun array, consisting of two 45 in\3\ 
or two 105 in\3\ GI airguns as the primary energy source and a 100 m 
streamer containing hydrophones. The airgun array will have a supply 
firing pressure of 2,000 pounds per square inch (psi) and 2,200 psi 
when at high pressure stand-by (i.e., shut-down). The regulator is 
adjusted to ensure that the maximum pressure to the GI airguns is 2,000 
psi, but there are times when the GI airguns may be operated at 
pressures as low as 1,750 to 1,800 psi Seismic pulses for the GI 
airguns will be emitted at intervals of approximately 5 seconds. At 
speeds of approximately 9.3 km/hr, the shot intervals correspond to 
spacing of approximately will be 12.5 m (41 ft) during the study. There 
would be approximately 720 shots per hour. During firing, a brief 
(approximately 0.03 second) pulse sound is emitted; the airguns will be 
silent during the intervening periods. The dominant frequency 
components range from two to 188 Hertz (Hz).
    The GI airguns would be used in harmonic mode, that is, the volume 
of the injector chamber (I) of each GI airgun is equal to that of its 
generator chamber (G): 45 in\3\ and 105 in\3\ for each airgun array. 
Each airgun would be initially configured to a displacement volume of 
45 in\3\ for the generator and injector. The generator chamber of each 
GI airgun in the primary source, the one responsible for introducing 
the sound pulse into the ocean, is 45 in\3\. The injector chamber 
injects air into the previously-generated bubble to maintain its shape, 
and does not introduce more sound into the water. The airguns would 
fire the compressed air volume in unison in a harmonic mode. In 
harmonic mode, the injector volume is designed to destructively 
interfere with the reverberations of the generator (source component). 
Firing the airguns in harmonic mode maximizes resolution in the data 
and minimizes any excess noise in the water column or data caused by 
the reverberations (or bubble pulses). The two GI airguns will be 
spaced approximately 3 or 6 m (9.8 or 19.7 ft) apart, side-by-side, 
between 15 and 40 m (49.2 and 131.2 ft) behind the Palmer, at a depth 
of up to 3 m during the surveys. If needed to improve penetration of 
the strata, the two airguns may be reconfigured to a displacement 
volume of 105 in\3\ each and would still be considered a low-energy 
acoustic source as defined in the NSF/USGS PEIS. Therefore, there are 
three possible two airgun array configurations: Two 45/45 in\3\ airguns 
separated by 3 m, two 45/45 in\3\ airguns separated by 6 m, and two 
105/105 in\3\ airguns separated by 3 m. The two 45/45 in\3\ airguns 
separated by 3 m layout is preferred, the two 45/45 in\3\ separated by 
6 m layout would be used in the event the middle of the three 45/45 
in\3\ airgun fails, and the two 105/105 in\3\ airguns separated by 3 m 
would be used only if additional penetration is needed. To summarize, 
two strings of GI airguns would be available: (1) Three 45/45 in\3\ 
airguns on a single string where one of these is used as a ``hot 
spare'' in the event of

[[Page 467]]

failure of one of the other two airguns, these three GI airguns are 
separated by 3 m; and (2) two 105/105 in\3\ airguns on a second string 
without a ``hot spare.'' The total effective volume will be 90 or 210 
in\3\. The two strings would be spaced 14 m (45.9 ft) apart, on either 
side of the midline of the vessel, however, only one string at a time 
would be used.
    The Nucleus modeling software used at Lamont-Doherty Earth 
Observatory of Columbia University (L-DEO) does not include GI airguns 
as part of its airgun library, however signatures and mitigation models 
have been obtained for two 45 in\3\ G airguns at 2 m tow depth and two 
105 in\3\ G airguns at 3 m tow depth that are close approximations. For 
the two 45 in\3\ airgun array, the source output (downward) is 230.6 dB 
re: 1 [mu]Pam for 0-to-peak and 235.9 dB re: 1 [mu]Pam for peak-to-
peak. For the two 105 in\3\ airgun array, the source output (downward) 
is 234.4 dB re: 1 [mu]Pam 0-to-peak and 239.8 dB re: 1 [mu]Pam for 
peak-to-peak. These numbers were determined using the aforementioned G-
airgun approximation to the GI airgun and using signatures filtered 
with DFS V out-256 Hz 72 dB/octave. The dominant frequency range would 
be 20 to 160 Hz for a pair of GI airguns towed at 3 m depth and 35 to 
230 Hz for a pair of GI airguns towed at 2 m depth.
    During the low-energy seismic survey, the vessel would attempt to 
maintain a constant cruise speed of approximately 5 knots. The airguns 
would operate continuously for no more than 16 hours at a time and 
duration of continuous operation is dependent on ice concentration. The 
cumulative duration of the airgun operations will not exceed 200 hrs. 
The relatively short, 24-channel hydrophone streamer would provide 
operational flexibility to allow the seismic survey to proceed along 
the designated cruise track with minimal interruption due to variable 
sea ice conditions. The design of the seismic equipment is to achieve 
high-resolution images of the glacial marine sequence stratigraphy with 
the ability to correlate to the ultra-high frequency sub-bottom 
profiling data and provide cross-sectional views to pair with the 
seafloor bathymetry. The cruise path would be designated once in the 
study area and would take care to avoid heavy ice conditions such as 
icebergs or dense areas of pack ice that could potentially damage the 
airguns or streamer and minimize proximity to potential marine 
receptors.
    Weather conditions that could affect the movement of sea ice and 
hinder the hydrophone streamer would be closely monitored, as well as 
conditions that could limit visibility. If situations are encountered 
which pose a risk to the equipment, impede data collection, or require 
the vessel to stop forward progress, the seismic survey equipment would 
be shut-down and retrieved until conditions improve. In general, the 
hydrophone streamer and sources could be retrieved in less than 30 
minutes.

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, 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. SPL 
does not take the duration of a sound into account.

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 downward-directed source levels of the airgun arrays 
used by NSF and ASC on the Palmer do not represent actual sound levels 
that can be measured at any location in the water. Rather, they 
represent the level that would be found 1 m (3.3 ft) from a 
hypothetical point source emitting the same total amount of sound as is 
emitted by the combined GI airguns. The actual received level at any 
location in the water near the GI airguns will not exceed the source 
level of the strongest individual source. In this case, that will be 
about 224.6 dB re 1 [mu]Pam peak, or 229.8 dB re 1 [mu]Pam peak-to-peak 
for the two 45 in\3\ airgun array, and 228.2 dB re 1 [mu]Pam peak or 
233.5 dB re 1 [mu]Pam peak-to-peak for the two 105 in\3\ airgun array. 
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. Actual levels experienced by any organism 
more than 1 m from either GI airgun will be significantly lower.
    Accordingly, Lamont-Doherty Earth Observatory of Columbia 
University (L-DEO) has predicted and modeled the received sound levels 
in relation to distance and direction from the two GI airgun array. A 
detailed description of L-DEO's modeling for this survey's marine 
seismic source arrays for protected species mitigation is provided in 
the NSF/USGS PEIS. These are the nominal source levels applicable to 
downward propagation. The NSF/USGS PEIS discusses the characteristics 
of the airgun pulses. NMFS refers the reviewers to those documents for 
additional information.

Predicted Sound Levels for the Airguns

    To determine exclusion zones for the airgun array to be used in the 
intermediate and deep water of the Gulf of Mexico (GOM), received sound 
levels have been modeled by L-DEO for a number of airgun 
configurations, including two 45 in\3\ and two 105 in\3\ G airguns, in 
relation to distance and direction from the airguns (see Figure 2 and 3 
in Attachment B of the IHA application). The model does not allow for 
bottom interactions, and is most directly applicable to deep water. 
Because the model results are for G airguns, which have more energy 
than GI airguns of the same size, those distances overestimate (by 
approximately 10%) the distances for the two 45 in\3\ GI airguns and 
two 105 in\3\ GI airguns, respectively. Although the distances are 
overestimated, no adjustments for this have been made to the radii 
distances in Table 2 (below). Based on the modeling, estimates of the 
maximum distances from the GI airguns where sound levels of 190, 180, 
and 160 dB re 1 [mu]Pa (rms) are predicted to be received in shallow, 
intermediate, and deep water are shown in Table 2 (see Table 1 of 
Attachment B of the IHA application).

[[Page 468]]

    Empirical data concerning the 190, 180, and 160 dB (rms) distances 
were acquired for various airgun arrays based on measurements during 
the acoustic verification studies conducted by L-DEO in the northern 
GOM in 2003 (Tolstoy et al., 2004) and 2007 to 2008 (Tolstoy et al., 
2009; Diebold et al., 2010). Results of the 18 and 36 airgun array are 
not relevant for the two GI airguns to be used in the proposed survey. 
The empirical data for the 6, 10, 12, and 20 airgun arrays indicate 
that, for deep water, the L-DEO model tends to overestimate the 
received sound levels at a given distance (Tolstoy et al., 2004). 
Measurements were not made for the two GI airgun array in deep water; 
however, NSF and ASC proposes to use the buffer and exclusion zones 
predicted by L-DEO's model for the proposed GI airgun operations in 
deep water, although they are likely conservative given the empirical 
results for the other arrays. Using the L-DEO model, Table 2 (below) 
shows the distances at which three rms sound levels are expected to be 
received from the two GI airguns. The 180 and 190 dB re 1 [mu]Pam (rms) 
distances are the safety criteria for potential Level A harassment as 
specified by NMFS (2000) and are applicable to cetaceans and pinnipeds, 
respectively. If marine mammals are detected within or about to enter 
the appropriate exclusion zone, the airguns will be shut-down 
immediately.
    Table 2 summarizes the predicted distances at which sound levels 
(160, 180, and 190 dB [rms]) are expected to be received from the two 
airgun array (45 in\3\ or 105 in\3\) operating in shallow (less than 
100 m [328 ft]), intermediate (100 to 1,000 m [328 to 3,280 ft]), and 
deep water (greater than 1,000 m [3,280 ft]) depths.
    Table 2-- Predicted and modeled (two 45 in\3\ and two 105 in\3\ GI 
airgun array) distances to which sound levels >=190, 180 and 160 dB re: 
1 [mu]Pa (rms) could be received in shallow, intermediate, and deep 
water during the proposed low-energy seismic survey in the Dumont 
d'Urville Sea of the Southern Ocean, January to March 2014.

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Predicted RMS radii distances  (m) for 2 GI airgun array
      Source and total volume         Tow depth      Water depth (m)    --------------------------------------------------------------------------------
                                         (m)                                       160 dB                     180 dB                     190 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
Two GI Airguns (45 in\3\).........            3   Shallow (<100).......  1,176....................  296......................  147.
                                                                         (3,858.3 ft).............  (971.1 ft)...............  (482.3 ft).
Two GI Airguns (45 in\3\).........            3   Intermediate (100 to   600......................  100......................  15.
                                                   1,000).               (1,968.5 ft).............  (328ft)..................  (49.2 ft).
Two GI Airguns (45 in\3\).........            3   Deep (>1,000)........  400......................  100......................  10.
                                                                         (1,312.3 ft).............  (328 ft).................  (32.8 ft).
Two GI Airguns (105 in\3\)........            3   Shallow (<100).......  1,970....................  511......................  294.
                                                                         (6,463.3 ft).............  (1,676.5 ft).............  (964.6 ft).
Two GI Airguns (105 in\3\)........            3   Intermediate (100 to   1,005....................  100......................  30.
                                                   1,000).               (3,297.2 ft).............                             (98.4 ft).
Two GI Airguns (105 in\3\)........            3   Deep (>1,000)........  670......................  100......................  20.
                                                                         (2,198.2 ft).............                             (65.6 ft).
--------------------------------------------------------------------------------------------------------------------------------------------------------

    NMFS expects that acoustic stimuli resulting from the proposed 
operation of the two GI airgun array has the potential to harass marine 
mammals. NMFS does not expect that the movement of the Palmer, during 
the conduct of the low-energy seismic survey, has the potential to 
harass marine mammals because of the relatively slow operation speed of 
the vessel (approximately 5 kts; 9.3 km/hr; 5.8 mph) during seismic 
acquisition.

Bathymetric Survey

    Along with the low-energy airgun operations, other additional 
geophysical measurements would be made using swath bathymetry, 
backscatter sonar imagery, high-resolution sub-bottom profiling 
(``CHIRP''), imaging, and magnetometer instruments. In addition, 
several other transducer-based instruments onboard the vessel would be 
operated continuously during the cruise for operational and 
navigational purposes. Operating characteristics for the instruments to 
be used are described below.
    Single-Beam Echosounder (Knudsen 3260)--The hull-mounted CHIRP 
sonar would be operated continuously during all phases of the cruise. 
This instrument is operated at 12 kHz for bottom-tracking purposes or 
at 3.5 kHz in the sub-bottom profiling mode. The sonar emits energy in 
a 30[deg] beam from the bottom of the ship.
    Single-Beam Echosounder (Bathy 2000)--The hull-mounted sonar 
characteristics of the Bathy 2000 are similar to the Knudsen 3260. Only 
one hull-mounted echosounder can be operated a time, and this source 
would be operated instead of the Knudsen 3260 only if needed (i.e., 
only one would be in continuous operation during the cruise).
    Multi-Beam Sonar (Simrad EM120)--The hull-mounted multi-beam sonar 
would be operated continuously during the cruise. This instrument 
operates at a frequency of 12 kHz, has an estimated maximum source 
energy level of 242 dB re 1[mu]Pa (rms), and emits a very narrow 
(<2[deg]) beam fore to aft and 150[deg] in cross-track. The multi-beam 
system emits a series of nine consecutive 15 ms pulses.
    Acoustic Doppler Current Profiler (ADCP Teledyne RDI VM-150)--The 
hull-mounted ADCP would be operated continuously throughout the cruise. 
The ADCP operates at a frequency of 150 kHz with an estimated acoustic 
output level at the source of 223.6 dB re 1[mu]Pa (rms). Sound energy 
from the ADCP is emitted as a 30[deg] conically-shaped beam.
    Acoustic Doppler Current Profiler (ADCP Ocean Surveyor OS-38)--The 
characteristics of this backup hull-mounted ADCP unit are similar to 
the Teledyne VM-150 and would be continuously operated.
    Acoustic Locator (Pinger)--An acoustic locator (i.e., pinger) would 
be deployed when using the Smith-McIntyre grab sampler and multi-corer 
(Mega-corer) to enable these devices to be located in the event they 
become detached from their lines. A pinger typically operates at a 
frequency of 12 kHz, generates a 5 ms pulse per second, and has an 
acoustical output of 162 dB re 1[mu]Pa (rms). A maximum total of 30 
samples would be obtained using these devices and require approximately 
one hour per sample; therefore, the pinger would operate for a total of 
30 hours.
    Passive Instruments--During the seismic survey in the Dumont 
d'Urville Sea, a precession magnetometer and Air-Sea gravity meter 
would be deployed. In addition, numerous (approximately 24) expendable 
bathythermograph (XBTs) probes would

[[Page 469]]

also be released (and none would be recovered) over the course of the 
cruise to obtain temperature data necessary to calculate sound velocity 
profiles used by the multi-beam sonar.

Core and Dredge Sampling

    The primary sampling goals involve the acquisition of marine 
sediment cores of various lengths up to 25 m (82 ft). It is anticipated 
that up to 65 sediment cores and grab samples and 12 rock dredge 
samples would be collected as summarized in Table 3 (Table 3 of the IHA 
application). Each core or grab sample would require approximately one 
hour per sample. All cores and dredges would be deployed using a steel 
cable/winch system.
    Approximately 75 m\2\ (807.3 ft\2\) of seafloor would be disturbed 
by each of four deployments of the dredge at three different sites 
(resulting in a total of 900 m\2\ [9,687.5 ft\2\] of affected seafloor 
for the project). The selection of the bottom sampling locations and 
sampling method would be based on observations of the seafloor, 
subsurface reflectivity, sediment type, and accessibility due to ice 
and weather conditions. Bottom sampling in the Mertz Glacier area would 
be limited to strategically selected locations including possible re-
sampling at a previous core site.

Table 3--Proposed Coring and Dredging Activities in the Dumont d'Urville
                                   Sea
------------------------------------------------------------------------
             Sampling device                   Number of  deployments
------------------------------------------------------------------------
Smith-MycIntyre grab sampler.............  10 to 15.
Multi-corer (Mega-corer).................  10 to 15.
Kasten corer (regular or jumbo)..........  20 to 25.
Jumbo piston corer.......................  8 to 10.
Box cage dredge..........................  10 to 12.
------------------------------------------------------------------------

    Limited sampling of rock material would be conducted using a dredge 
that would be towed along the seafloor for short distances 
(approximately 50 m [164 ft]) to collect samples of bedrock and ice 
rafted debris. The available dredges, which have openings of 0.5 to 1.5 
m (1.6 to 4.9 ft), would be deployed on rocky substrates. The locations 
of the proposed dredge sites are limited to the inner shelf (southern) 
perimeter of three areas: The Mertz Trough and two regions along the 
Sabrina Coast. Final selection of dredge sites will include review to 
ensure that the seamounts or corals in the area are avoided (AOA, 
2011).
    The Commission for the Conservation of Antarctic Marine Living 
Resources (CCAMLR) has adopted conservation measures (i.e., 22-06, 22-
07, and 22-09) to protect vulnerable marine ecosystems (VME), which 
include seamounts, hydrothermal vents, cold water corals, and sponge 
fields. The conservation measure 22-07 includes mitigation and 
reporting requirements if VME are encountered. The science team would 
follow these requirements (see Attachment C of the IHA application) if 
VME's are encountered while sampling the sea bottom.
    In addition, a camera and towed video system would be deployed at 
up to 25 sites. This device would lightly touch the seafloor to 
establish a baseline and rise to an optimum elevation to obtain the 
desired images.

Water Sampling and Current Measurements

    High-resolution conductivity, depth, and temperature (CTD) 
measurements would be collected to characterize the summer regional 
water mass stratification and circulation, and the meridional exchange 
of waters between the oceanic and shelf regimes. These physical 
measurements would involve approximately SeaBird CTD system casts 
including the use of a lowered ADCP (LADCP).
    The LADCP would consist of two Teledyne RDI Workhorse Monitor ADCPs 
mounted on the CTD/rosette frame and one oriented upward and the other 
downward. The LADCP and frame would be raised and lowered by cable and 
winch. The LADCPs would operate at a frequency of 307.2 kHz, with an 
estimated output acoustic pressure along each 4 beams of 216.3 dB re 
1[mu]Pa at 1 m. The beams are angled at 20 degrees from the centerline 
of the ADCP head, with a beam angle of 4 degrees for the individual 
beams. Typical pulse duration is 5.7 ms, with a typical repetition rate 
of 1.75 s. The upward and downward-looking ADCPs are operated in 
master-salve mode so that only one head pings at a time. The LADCP 
would be operated approximately one hour at every CTD/rosette station 
(maximum of 100 stations) for a total of 100 hours of operation.
    These instruments would be used to profile the full water column 
for temperature, salinity (conductivity), dissolved oxygen and currents 
at a series of transects in the study area. Discrete water samples 
would be collected for salinity and dissolved oxygen to monitor CTD/
rosette performance, and for oxygen isotopes to assess meltwater 
content. Water samples would also be collected for development and 
interpretation of marine sediment proxies using Niskin bottles.
    Observations of the thermal structure along other portions of the 
cruise track would be made using an underway CTD system and XBTs while 
the seafloor is swath-mapped. The number and spacing of stations would 
be adjusted according to ocean features discovered through multi-beam 
swath mapping and the sea ice conditions. If portions of the study area 
are inaccessible to the NBP, a contingency sampling focused on the 
inflows of MDCW would be pursued in adjacent shelf troughs.
    It is noted that underway ADCP on the Palmer can, under ideal 
conditions, obtain profiles of ocean currents to depths greater than 
800 m (2,624.7 ft). On continental shelves where depths may be less 
than the range of the ADCP, the underway profiles cannot resolve the 
deepest 15% of the water column due to side lobe reflections from the 
bottom which contaminate the water column Doppler returns. For a depth 
of 800 m, expected in the MCDW, currents in the lower 120 m (393.7 ft) 
could not be measured by the ship ADCP; therefore, the lowered ADCP can 
provide accurate current profiles to within a few meters of the bottom 
and provide complete coverage of the velocity field at each CTD 
station.

Instrumentation Moorings

    Four instrumented moorings would be deployed during the proposed 
cruise to measure current, temperature, and salinity (conductivity) 
continuously. Two of the moorings would be deployed for approximately 
one month (short-term moorings) and two moorings would be deployed for 
approximately one year (long-term moorings). The two short-term 
moorings and one long-term mooring would include ADCP paired with CTD 
recorders, and additional intermediate T (i.e., temperature) recorders. 
The characteristics of the ADCP units deployed on the moorings are 
similar to the Teledyne VM-150; the moored ADCPs operate at frequencies 
of 75 kHz (one unit) and 300 kHz (two units). The fourth mooring would 
be equipped with sediment traps, a CTD recorder and intermediate T 
recorders, and be deployed for approximately one year (long-term 
mooring). The two long-term moorings would be retrieved approximately 
one year later by a U.S. Arctic Program (USAP) vessel or collaborators 
from other countries.
    Subject to sea ice conditions, these moorings would preferably be 
placed in front of Totten Glacier, but otherwise as close as possible 
inside adjacent cross-shelf troughs. If access to the inner shelf is 
not allowed by sea ice conditions we would attempt mooring deployments 
within the outer shelf close to the

[[Page 470]]

troughs mouth, where the Totten Glacier is more directly connected to 
inflows from the oceanic domain offshore. The two long-term moorings 
would be deployed within 16 km of each other. The short-term moorings 
would be within a few kilometers of each other and no farther than 32 
km (17.3 nmi) from the long-term moorings. All instruments would be 
kept at depths below 250 m (820.2 ft) to minimize damage or loss by 
icebergs.
    The moorings would temporarily attached to anchors and be recovered 
using acoustic release mechanisms. The mooring recovery process would 
be similar regardless of mooring type or when they would be retrieved. 
Locating the moorings and releasing the moorings from the steel 
railroad wheel anchors (which would not be recovered) would be 
accomplished by transmitting sound over a period of several seconds. 
This is done with an acoustic deck command unit that sends a sequence 
of coded pulses to the receiving units, the acoustic releases, 
connected to the mooring anchors. The acoustic releases response to 
acknowledge the receipt of commands from the deck unit is by 
transmitting a short sequence of pulses back. Both of the acoustic 
units (onboard deck unit and moored releases) operate at frequencies 
between approximately 7 and 15 kHz. The beam pattern is approximately 
omnidirectional. The acoustic source level is less than 192 dB re 
1[mu]Pa at 1 m.
    In addition to the U.S. moorings described above, three new 
moorings would be deployed on behalf of Australia's national science 
agency the Commonwealth of Scientific and Industrial Research 
Organisation (CSIRO) Physical Oceanography group in the Totten Glacier 
region by the project team. These moorings would be retrieved 
approximately one year later by collaborators from other countries. 
Also, during this cruise, three CSIRO moorings that were deployed over 
a year ago in the western outlet of the Mertz-Ninnis Trough would be 
recovered. The recovery process and acoustic sources described above 
for the U.S. moorings would be used for recovery of the CSIRO moorings.

Icebreaking

    Icebreaking is considered by NMFS to be a continuous sound and NMFS 
estimates that harassment occurs when marine mammals are exposed to 
continuous sounds at a received sound level of 120 dB SPL or above. 
Potential takes of marine mammals may ensue from icebreaking activity 
in which the Palmer is expected to engage in Antarctic waters (i.e., 
along the George V and Oates Coast of East Antarctica, >65[deg] South, 
between 140[deg] and 165[deg] East). While breaking ice, the noise from 
the ship, including impact with ice, engine noise, and propeller 
cavitation, will exceed 120 dB (rms) continuously. If icebreaking does 
occur in Antarctic waters, NMFS, NSF and ASC expect it will occur 
during transit and non-seismic operations to gain access to coring, 
dredging, or other sampling locations and not during seismic airgun 
operations. The research activities and associated contingencies are 
designed to avoid areas of heavy sea ice condition. The buffer zone 
(160 dB [rms]) for the marine mammal Level B harassment threshold 
during the proposed activities is greater than the calculated radius 
during icebreaking. Therefore, if the Palmer breaks ice during seismic 
operations within the Antarctic waters (within the Dumont d'Urville Sea 
or other areas of the Southern Ocean), the more conservative and larger 
radius (i.e., that for seismic operations) will be used and supercede 
the buffer zone for icebreaking.
    In 2008, acousticians from Scripps Institution of Oceanography 
Marine Physical Laboratory and University of New Hampshire Center for 
Coastal and Ocean Mapping conducted measurements of SPLs of the Healy 
icebreaking under various conditions (Roth and Schmidt, 2010). The 
results indicated that the highest mean SPL (185 dB) was measured at 
survey speeds of 4 to 4.5 kts in conditions of 5/10 ice and greater. 
Mean SPL under conditions where the ship was breaking heavy ice by 
backing and ramming was actually lower (180 dB). In addition, when 
backing and ramming, the vessel is essentially stationary, so the 
ensonified area is limited for a short period (on the order of minutes 
to tens of minutes) to the immediate vicinity of the vessel until the 
ship breaks free and once again makes headway.
    The 120 dB received sound level radius around the Healy while 
icebreaking was estimated by researchers (USGS, 2010). Using a 
spherical spreading model, a source level of 185 dB decays to 120 dB in 
about 1,750 m (5,741.5 ft). This model is corroborated by Roth and 
Schmidt (2010). Therefore, as the ship travels through the ice, a watch 
3,500 m (11,482.9 ft) wide would be subject to sound levels greater 
than or equal to 120 dB. This results in potential exposure of 3,500 
km\2\ (1,020.4 nmi\2\) to sounds greater than or equal to 120 dB from 
icebreaking.
    Data characterizing the sound levels generated by icebreaking 
activities conducted by the Palmer are not available; therefore, data 
for noise generating from an icebreaking vessel such as the U.S. Coast 
Guard Cutter (USCGC) Healy will be used as a proxy. It is noted that 
the Palmer is a smaller vessel and has less icebreaking capability than 
the U.S. Coast Guard's other polar icebreakers, being only capable of 
breaking ice up to 1 m thick at speeds of 3 kts (5.6 km/hr or 3 nmi). 
Therefore, the sound levels that may be generated by the Palmer are 
expected to be lower than the conservative levels estimated and 
measured for the Healy. Researchers will work to minimize time spent 
breaking ice as science operations are more difficult to conduct in icy 
conditions since the ice noise degrades the quality of the seismic and 
ADCP data and time spent breaking ice takes away from time supporting 
scientific research. Logistically, if the vessel were in heavy ice 
conditions, researchers would not tow the airgun array and streamer, as 
this would likely damage equipment and generate noisy data. It is 
possible that the seismic survey can be performed in low ice conditions 
if the Palmer could generate an open path behind the vessel.
    Because the Palmer is not rated to break multi-year ice routinely, 
operations generally avoid transiting through older ice (i.e., 2 years 
or older, thicker than 1 m). If sea ice is encountered during the 
cruise, it is anticipated the Palmer will proceed primarily through one 
year sea ice, and possibly some new, very thin ice, and would follow 
leads wherever possible. Satellite imagery from the Totten region 
documents that sea ice is at its minimum extent during the month of 
February. The most recent image for the region, from November 21, 2013, 
shows that the sea ice is currently breaking up, with a significant 
coastal lead of open water. Based on a maximum sea ice extent of 250 km 
(135 nmi) and estimating that NSF and ASC will transit to the innermost 
shelf and back into open water twice, a round trip transit in each of 
the potential work regions, NSF and ASC estimate that the Palmer will 
actively break ice up to a distance of 1,000 km (540 nmi). Based on a 
ship's speed of 5 kts under moderate ice conditions, this distance 
represents approximately 108 hrs of icebreaking operations. It is noted 
that typical transit through areas primarily open water and containing 
brash ice or pancake ice will not be considered icebreaking.

[[Page 471]]

Dates, Duration, and Specified Geographic Region

    The proposed project and survey sites are located in selected 
regions of the Dumont d'Urville Sea in the Southern Ocean off the coast 
of East Antarctica and focus on the Totten Glacier and Moscow 
University Ice Shelf, located on the Sabrina Coast, from greater than 
approximately 64[deg] South and between approximately 95 to 135[deg] 
East (see Figure 2 of the IHA application), and the Mertz Glacier and 
Cook Ice Shelf systems located on the George V and Oates Coast, from 
greater than approximately 65[deg] South and between approximately 140 
to 165[deg] East in International Waters. The proposed study sites are 
characterized by heavy ice cover, with a seasonal break-up in the ice 
that structures biological patterns. The proposed studies would occur 
in both areas, or entirely in one or the other, depending on ice 
conditions. Figure 3 of the IHA application illustrates the limited 
detailed bathymetry of the two study areas. Ice conditions encountered 
during the previous surveys in the region limited the area where 
bathymetric data could be collected. Water depths in the survey area 
range from approximately 100 to 1,000 m, and possibly exceeding 1,000 m 
in some areas. There is limited information on the depths in the study 
area and therefore more detailed information on bathymetry is not 
available. Figures 2 and 3 of the IHA application illustrate the 
limited available detailed bathymetry of the two proposed study areas 
due to ice conditions encountered during previous surveys in the 
region. The proposed seismic survey would be within an area of 
approximately 5,628 km\2\ (1,640.9 nmi\2\). This estimate is based on 
the maximum number of kilometers for the seismic survey (2,800 km) 
times the predicted rms radii (m) based on modeling and empirical 
measurements (assuming 100% use of the two 105 in\3\ GI airguns in 100 
to 1,000 m water depths) which was calculated to be 1,005 m (3,297.2 
ft).
    The icebreaking will occur, as necessary, between approximately 66 
to 70[deg] South and between 140 to 165[deg] East. The total distance 
in the region of the vessel will travel include the proposed seismic 
survey and transit to dredging or sampling locations and will represent 
approximately 5,600 km (3,023.8 nmi). Based on a maximum sea ice extent 
of 250 km (135 nmi) and estimating that NSF and ASC will transit to the 
innermost shelf and back into open water twice, a round trip transit in 
each of the potential work regions, NSF and ASC estimate that the 
Palmer will actively break ice up to a distance of 1,000 km (540 nmi). 
Based on a ship's speed of 5 kts under moderate ice conditions, this 
distance represents approximately 108 hrs of icebreaking operations.
    The Palmer is expected to depart from Hobart, Tasmania on 
approximately January 29, 2014 and arrive at Hobart, Tasmania on 
approximately March 16, 2014. Research operations would be over a span 
of 45-days, including to and from port. Ice-free or very low 
concentrations of sea ice are required in order to collect high quality 
seismic data and not impede passage of the vessel between sampling 
locations. This requirement restricts the cruise to operating in mid to 
late austral summer when the ice concentrations are typically the 
lowest. Some minor deviation from this schedule is possible, depending 
on logistics and weather (i.e., the cruise may depart earlier or be 
extended due to poor weather; there could be additional days of seismic 
operations if collected data are deemed to be of substandard quality).

Description of the Marine Mammals in the Area of the Proposed Specified 
Activity

    The marine mammals that generally occur in the proposed action area 
belong to three taxonomic groups: Mysticetes (baleen whales), 
odontocetes (toothed whales), and pinnipeds (seals and sea lions). The 
marine mammal species that potentially occur within the Southern Ocean 
in proximity to the proposed action area in the Dumont d'Urville Sea 
include 28 species of cetaceans and 6 species of pinnipeds.
    The Dumont d'Urville Sea may be a feeding ground for many of these 
marine mammals. Many of the species that may be potentially present in 
the study area seasonally migrate to higher latitudes along the east 
coast of Antarctica. In general, most species (except for the killer 
whale) migrate north in the middle of the austral winter and return to 
Antarctica in the early austral summer. Some species, particularly 
Antarctic minke (Balaenoptera bonaerensis) and killer whales (Orcinus 
orca), are expected to be present in higher concentrations along the 
ice edge (SCAR, 2002). The 6 species of pinnipeds that are found in the 
Southern Ocean and which may be present in the proposed study area 
include the crabeater (Lebodon carcinophagus), leopard (Hydrurga 
leptonyx), Wedell (Leptonychotes weddellii), Ross (Ommatophoca rossii), 
southern elephant (Mirounga leonina), and Antarctic fur seal 
(Arctocephalus gazella). Many of these pinniped species breed on either 
the pack ice or sub-Antarctic islands. Since the southern elephant seal 
and Antarctic fur seal haul-outs and rookeries are located on sub-
Antarctic islands and prefer beaches, they are more common north of the 
seasonally shifting pack ice found in the proposed study area; 
therefore, these two species have not been considered further. Marine 
mammal species listed as endangered under the U.S. Endangered Species 
Act of 1973 (ESA; 16 U.S.C. 1531 et seq.), includes the southern right 
(Eubalaena australis), humpback (Megaptera novaeangliae), sei 
(Balaenoptera borealis), fin (Balaenoptera physalus), blue 
(Balaenoptera musculus), and sperm (Physeter macrocephalus) whale. Of 
those endangered species, the humpback, sei, fin, blue, and sperm whale 
are likely to be encountered in the proposed survey area.
    Various national Antarctic research programs along the coast of 
East Antarctica have conducted scientific cruises that included data on 
marine mammal sightings. These observations were made primarily between 
30[deg] East and 170[deg] East and north to 60[deg] South. The reported 
cetacean sightings are summarized in Tables 5 to 7 of the IHA 
application. For pinnipeds, observations made during a scientific 
cruise over a 13-day period in East Antarctica are summarized in Table 
8 of the IHA application. These observations were made below 60[deg] 
South and between 110[deg] East to 165[deg] East and include sightings 
of individual animals in the water as well as individuals that were 
hauled-out (i.e., resting on the surface of the sea ice).
    Records from the International Whaling Commission's Southern Ocean 
Whale and Ecosystem Research (IWC-SOWER) circumpolar cruises were also 
considered. In addition to the 14 species known to occur in the Dumont 
d'Urville Sea of the Southern Ocean, there are 18 cetacean species with 
ranges that are known to occur in the sub-Antarctic waters of the study 
area which may also feed and/or migrate to the Southern Ocean during 
the austral summer, these include the southern right, pygmy right 
(Caperea marginata), Bryde's (Balaenoptera brydei), dwarf minke 
(Balaenoptera acutorostrata spp.), pygmy blue (Balaenoptera musculus 
brevicauda), pygmy dwarf sperm whale (Kogia breviceps), Arnoux's beaked 
(Berardius arnuxii), Blainville's beaked whale (Mesoplodon 
densirostris), Cuvier's beaked (Ziphius cavirostris), Shepherd's beaked 
(Tasmacetus shepherdi), Southern bottlenose (Hyperoodon planifrons), 
Andrew's

[[Page 472]]

beaked (Mesoplodon bowdoini), Hector's beaked (Mesoplodon hectori), 
Gray's beaked (Mesoplodon grayi), strap-toothed beaked (Mesoplodon 
layardii), spade-toothed beaked (Mesoplodon traversii), southern right 
whale dolphin (Lissodelphis peronii), Dusky (Lagenorhynchus obscurus), 
and bottlenose dolphin (Tursiops truncatus). However, these species 
have not been sighted and are not expected to occur where the proposed 
activities would take place. These species are not considered further 
in this document. Table 4 (below) presents information on the 
abundance, distribution, population status, conservation status, and 
population trend of the species of marine mammals that may occur in the 
proposed study area during February to March 2014.

  Table 4--The Habitat, Regional Abundance, and Conservation Status of Marine Mammals That May Occur In or Near
             the Proposed Low-Energy Seismic Survey Area in the Antarctic Area of the Southern Ocean
                    [See text and Tables 4 in NSF and ASC's application for further details]
----------------------------------------------------------------------------------------------------------------
                                                       Population
            Species                  Habitat            estimate        ESA \1\      MMPA \2\   Population trend
----------------------------------------------------------------------------------------------------------------
Mysticetes:
    Southern right whale        Coastal, pelagic.  8,000 \3\ to       EN.........  D..........  Increasing.
     (Eubalaena australis).                         15,000 \4\.
    Pygmy right whale (Caperea  Coastal, pelagic.  NA...............  NL.........  NC.........  NA.
     marginata).
    Humpback whale (Megaptera   Pelagic,           35,000 to 40,000   EN.........  D..........  Increasing.
     novaeangliae).              nearshore          \3\--Worldwide.
                                 waters, and       9,484 \5\--Scotia
                                 banks.             Sea and
                                                    Antarctica
                                                    Peninsula.
    Dwarf minke whale           Pelagic and        NA...............  NL.........  NC.........  NA.
     (Balaenoptera               coastal.
     acutorostrata sub-
     species).
    Antarctic minke whale       Pelagic, ice       Several 100,000    NL.........  NC.........  Stable.
     (Balaenoptera               floes.             \3\--Worldwide.
     bonaerensis).                                 18,125 \5\--
                                                    Scotia Sea and
                                                    Antarctica
                                                    Peninsula.
    Bryde's whale               Pelagic and        NA...............  NL.........  NC.........  NA.
     (Balaenoptera brydei).      coastal.
    Sei whale (Balaenoptera     Primarily          80,000 \3\--       EN.........  D..........  NA.
     borealis).                  offshore,          Worldwide.
                                 pelagic.
    Fin whale (Balaenoptera     Continental        140,000 \3\--      EN.........  D..........  NA.
     physalus).                  slope, pelagic.    Worldwide.
                                                   4,672 \5\--Scotia
                                                    Sea and
                                                    Antarctica
                                                    Peninsula.
    Blue whale (Balaenoptera    Pelagic, shelf,    8,000 to 9,000     EN.........  D..........  NA.
     musculus).                  coastal.           \3\--Worldwide.
                                                   1,700 \6\--
                                                    Southern Ocean.
Odontocetes:
    Sperm whale (Physeter       Pelagic, deep sea  360,000 \3\--      EN.........  D..........  NA.
     macrocephalus).                                Worldwide.
                                                   9,500 \3\--
                                                    Antarctic.
    Pygmy sperm whale (Kogia    Pelagic, slope...  NA...............  NL.........  NC.........  NA.
     breviceps).
    Arnoux's beaked whale       Pelagic..........  NA...............  NL.........  NC.........  NA.
     (Berardius arnuxii).
    Blainville's beaked whale   Pelagic..........  NA...............  NL.........  NC.........  NA.
     (Mesoplodon densirostris).
    Cuvier's beaked whale       Pelagic..........  NA...............  NL.........  NC.........  NA.
     (Ziphius cavirostris).
    Shepherd's beaked whale     Pelagic..........  NA...............  NL.........  NC.........  NA.
     (Tasmacetus shepherdi).
    Southern bottlenose whale   Pelagic..........  500,000 \3\--      NL.........  NC.........  NA.
     (Hyperoodon planifrons).                       South of
                                                    Antarctic
                                                    Convergence.
    Andrew's beaked whale       Pelagic..........  NA...............  NL.........  NC.........  NA.
     (Mesoplodon bowdoini).
    Hector's beaked whale       Pelagic..........  NA...............  NL.........  NC.........  NA.
     (Mesoplodon hectori).
    Gray's beaked whale         Pelagic..........  NA...............  NL.........  NC.........  NA.
     (Mesoplodon grayi).
    Strap-toothed beaked whale  Pelagic..........  NA...............  NL.........  NC.........  NA.
     (Mesoplodon layardii).
    Spade-toothed beaked whale  Pelagic..........  NA...............  NL.........  NC.........  NA.
     (Mesoplodon traversii).

[[Page 473]]

 
    Killer whale (Orcinus       Pelagic, shelf,    80,000 \3\--South  NL.........  NC.........  NA.
     orca).                      coastal, pack      of Antarctic
                                 ice.               Convergence.
                                                   25,000 \7\--
                                                    Southern Ocean.
    Long-finned pilot whale     Pelagic, shelf,    200,000 3 8--      NL.........  NC.........  NA.
     (Globicephala melas).       coastal.           South of
                                                    Antarctic
                                                    Convergence.
    Bottlenose dolphin          Offshore,          >625,500 \3\--     NL.........  NC.........  NA.
     (Tursiops truncatus).       inshore,           Worldwide.
                                 coastal,
                                 estuaries.
    Southern right whale        Pelagic..........  NA...............  NL.........  NC.........  NA.
     dolphin (Lissodelphis
     peronii).
    Dusky dolphin               Coastal,           NA...............  NL.........  NC.........  NA.
     (Lagenorhynchus obscurus).  continental
                                 shelf and slope.
    Hourglass dolphin           Pelatic, ice edge  144,000 \3\......  NL.........  NC.........  NA.
     (Lagenorhynchus cruciger).
    Spectacled porpoise         Coastal, pelagic.  NA...............  NL.........  NC.........  NA.
     (Phocoena dioptrica).
Pinnipeds:
    Crabeater seal (Lobodon     Coastal, pack ice  5,000,000 to       NL.........  NC.........  Increasing.
     carcinophaga).                                 15,000,000 3 9.
    Leopard seal (Hydrurga      Pack ice, sub-     220,000 to         NL.........  NC.........  NA.
     leptonyx).                  Antarctic          440,000 3 10.
                                 islands.
    Ross seal (Ommatophoca      Pack ice, smooth   130,000 \3\......  NL.........  NC.........  NA.
     rossii).                    ice floes,
                                 pelagic.
    Wedell seal (Leptonychotes  Fast ice, pack     500,000 to         NL.........  NC.........  NA.
     weddellii).                 ice, sub-          1,000,000 3 11.
                                 Antarctic
                                 islands.
    Southern elephant seal      Coastal, pelagic,  640,000 \12\ to    NL.........  NC.........  Decreasing,
     (Mirounga leonina).         sub-Antarctic      650,000 \3\.                                 increasing or
                                 waters.                                                         stable
                                                                                                 depending on
                                                                                                 breeding
                                                                                                 population.
    Antarctic fur seal          Shelf, rocky       1,600,000 \13\ to  NL.........  NC.........  Increasing.
     (Arctocephalus gazella).    habitats.          3,000,000 \3\.
----------------------------------------------------------------------------------------------------------------
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, S = Strategic, NC = Not Classified.
\3\ Jefferson et al., 2008.
\4\ Kenney, 2009.
\5\ Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) survey area (Reilly et al.,
  2004).
\6\ Sears and Perrin, 2009.
\7\ Ford, 2009.
\8\ Olson, 2009.
\9\ Bengston, 2009.
\10\ Rogers, 2009.
\11\ Thomas and Terhune, 2009.
\12\ Hindell and Perrin, 2009.
\13\ Arnould, 2009.

    Refer to sections 3 and 4 of NSF and ASC's IHA application for 
detailed information regarding the abundance and distribution, 
population status, and life history and behavior of these other marine 
mammal species and their occurrence in the proposed project area. The 
IHA application also presents how NSF and ASC calculated the estimated 
densities for the marine mammals in the proposed survey area. NMFS has 
reviewed these data and determined them to be the best available 
scientific information for the purposes of the proposed IHA.

Potential Effects 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, 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). 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 ``Programmatic Environmental

[[Page 474]]

Impact Statement/Overseas Environmental Impact Statement prepared for 
Marine Seismic Research that is funded by the National Science 
Foundation and conducted by the U.S. Geological Survey'' (NSF/USGS, 
2011).

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) (Richardson, et al., 1995; Thorpe, 1963), 
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. That is often true even in cases when the pulsed sounds must 
be readily audible to the animals based on measured received levels and 
the hearing sensitivity of the marine mammal group. Although various 
baleen whales and toothed whales, and (less frequently) pinnipeds have 
been shown to react behaviorally to airgun pulses under some 
conditions, at other times marine mammals of all three types have shown 
no overt reactions. The relative responsiveness of baleen and toothed 
whales are quite variable.

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).
    The airguns for the proposed low-energy seismic survey have 
dominant frequency components of 2 to 188 Hz. This frequency range 
fully overlaps the lower part of the frequency range of odontocete 
calls and/or functional hearing (full range about 150 Hz to 180 kHz). 
Airguns also produce a small portion of their sound at mid and high 
frequencies that overlap most, if not all, frequencies produced by 
odontocetes. While it is assumed that mysticetes can detect acoustic 
impulses from airguns and vessel sounds (Richardson et al., 1995a), 
sub-bottom profilers, pingers, and most of the multi-beam echosounders 
would likely be detectable by some mysticetes based on presumed 
mysticete hearing sensitivity. Odontocetes are presumably more 
sensitive to mid to high frequencies produced by the mulit-beam 
echosounders, sub-bottom profilers, and pingers than to the dominant 
low frequencies produced by the airguns and vessel. A more 
comprehensive review of the relevant background information for 
odontocetes appears in Section 3.6.4.3, Section 3.7.4.3 and Appendix E 
of the NSF/USGS PEIS (2011).
    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.
    Pinnipeds have the most sensitive hearing and/or produce most of 
their sounds in frequencies higher than the dominant components of 
airgun sound, but there is some overlap in the frequencies of the 
airgun pulses and the calls. However, the intermittent nature of airgun 
pules presumably reduces 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 (Eubalaena glacialis) 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 subtle to conspicuous changes in behavior, movement, and 
displacement. Reactions to sound, if any, depend on species, state of 
maturity, experience, current activity, reproductive state, time of 
day, and many other factors (Richardson et al., 1995; Wartzok et al., 
2004; Southall et al., 2007; Weilgart, 2007). These behavioral 
reactions are often shown as: Changing durations of surfacing and 
dives, number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities; changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping); avoidance of areas where noise sources are located; and/or 
flight responses (e.g., pinnipeds flushing into the water from haul-
outs or rookeries). If a marine mammal does react briefly to an 
underwater sound by changing its behavior or moving a small distance, 
the impacts of the change are unlikely to be significant to the 
individual, let alone the stock or population. However, if a sound 
source displaces marine mammals from an important feeding or breeding 
area for a

[[Page 475]]

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.
    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 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 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).
    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 
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 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 Pacific gray whales

[[Page 476]]

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 versus silent 
(Stone, 2003; Stone and Tasker, 2006). However, these whales tended to 
exhibit localized avoidance, remaining significantly further (on 
average) from the airgun array during seismic operations compared with 
non-seismic periods (Stone and Tasker, 2006). 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 Malme et al., 
1984; Richardson et al., 1995; Allen and Angliss, 2010). The western 
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--Little systematic information is 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 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 or less, and some individuals show no apparent avoidance. Captive 
bottlenose dolphins and beluga whales (Delphinapterus leucas) exhibited 
changes in behavior when exposed to strong pulsed sounds similar in 
duration to those typically used in seismic surveys (Finneran et al., 
2000, 2002, 2005). However, the animals tolerated high received levels 
of sound before exhibiting aversive behaviors.
    Results of porpoises depend on species. The limited available data 
suggest that harbor porpoises (Phocoena phocoena) show stronger 
avoidance of seismic operations than do Dall's porpoises (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 
(Hyperoodon ampullatus) remained in the general area and continued to 
produce high-frequency clicks when exposed to sound pulses from distant 
seismic surveys (Gosselin and Lawson, 2004; Laurinolli and Cochrane, 
2005; Simard et al., 2005). Most beaked whales tend to avoid 
approaching vessels of other types (e.g., Wursig et al., 1998). They 
may also dive for an extended period when approached by a vessel (e.g., 
Kasuya, 1986), although it is uncertain how much longer such dives may 
be as compared to dives by undisturbed beaked whales, which also are 
often quite long (Baird et al., 2006; Tyack et al., 2006). Based on a 
single observation,

[[Page 477]]

Aguilar-Soto et al. (2006) suggested that foraging efficiency of 
Cuvier's beaked whales may be reduced by close approach of vessels. In 
any event, it is likely that most beaked whales would also show strong 
avoidance of an approaching seismic vessel, although this has not been 
documented explicitly. In fact, Moulton and Holst (2010) reported 15 
sightings of beaked whales during seismic studies in the Northwest 
Atlantic; seven of those sightings were made at times when at least one 
airgun was operating. There was little evidence to indicate that beaked 
whale behavior was affected by airgun operations; sighting rates and 
distances were similar during seismic and non-seismic periods (Moulton 
and Holst, 2010).
    There are increasing indications that some beaked whales tend to 
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, 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--Pinnipeds are not likely to show a strong avoidance 
reaction to the airgun array. Visual monitoring from seismic vessels 
has shown only slight (if any) avoidance of airguns by pinnipeds, and 
only slight (if any) changes in behavior. In the Beaufort Sea, some 
ringed seals avoided an area of 100 m to (at most) a few hundred meters 
around seismic vessels, but many seals remained within 100 to 200 m 
(328 to 656 ft) of the trackline as the operating airgun array passed 
by (e.g., Harris et al., 2001; Moulton and Lawson, 2002; Miller et al., 
2005.). Ringed seal (Pusa hispida) sightings averaged somewhat farther 
away from the seismic vessel when the airguns were operating than when 
they were not, but the difference was small (Moulton and Lawson, 2002). 
Similarly, in Puget Sound, sighting distances for harbor seals (Phoca 
vitulina) 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).
    During seismic exploration off Nova Scotia, gray seals (Halichoerus 
grypus) exposed to noise from airguns and linear explosive charges did 
not react strongly (J. Parsons in Greene et al., 1985). Pinnipeds in 
both water and air, sometimes tolerate strong noise pulses from non-
explosive and explosive scaring devices, especially if attracted to the 
area for feeding and reproduction (Mate and Harvey, 1987; Reeves et 
al., 1996). Thus pinnipeds are expected to be rather tolerant of, or 
habituate to, repeated underwater sounds from distant seismic sources, 
at least when the animals are strongly attracted to the area.

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 2 (above) 
presents the estimated distances from the Palmer's airguns at which the 
received energy level (per pulse, flat-weighted) would be expected to 
be greater than or equal to 180 and 190 dB re 1 [mu]Pa (rms).
    To avoid the potential for injury, 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). 
NMFS believes that to avoid the potential for Level A harassment, 
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

[[Page 478]]

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).
    In pinnipeds, researchers have not measured TTS thresholds 
associated with exposure to brief pulses (single or multiple) of 
underwater sound. Initial evidence from more prolonged (non-pulse) 
exposures suggested that some pinnipeds (harbor seals in particular) 
incur TTS at somewhat lower received levels than do small odontocetes 
exposed for similar durations (Kastak et al., 1999, 2005; Ketten et 
al., 2001). The TTS threshold for pulsed sounds has been indirectly 
extimated as being an SEL of approximately 171 dB re 1 
[mu]Pa\2\[middot]s (Southall et al., 2007) which would be equivalent to 
a single pulse with a received level of approximately 181 to 186 dB re 
1 [mu]Pa (rms), or a series of pulses for which the highest rms values 
are a few dB lower. Corresponding values for California sea lions and 
northern elephant seals (Mirounga angustirostris) are likely to be 
higher (Kastak et al., 2005).
    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 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.
    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.
    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

[[Page 479]]

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-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 to marine mammals will 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.
    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.

Potential Effects of Other Acoustic Devices and Sources

Multibeam Echosounder

    NSF and ASC will operate the Simrad EM120 multibeam echosounder 
from the source vessel during the planned study. Sounds from the 
multibeam echosounder are very short pulses, occurring for 15 ms, 
depending on water depth. Most of the energy in the sound pulses 
emitted by the multibeam 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 nine (in water greater than 
1,000 m deep) consecutive 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 Simrad EM120 are 
unlikely to be subjected to repeated pulses because of the narrow fore-
aft width of the beam and will receive only limited amounts of pulse 
energy because of the short pulses. Animals close to the ship (where 
the beam is narrowest) are especially unlikely to be ensonified for 
more than one 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 multibeam 
echosounder emits a

[[Page 480]]

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 Simrad EM120; and (2) are often directed close to horizontally, as 
well as omnidirectional, versus more downward and narrowly for the 
multibeam echosounder. The area of possible influence of the multibeam 
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 NSF and ASC's operations, the individual 
pulses will be very short, and a given mammal would not receive many of 
the downward-directed pulses as the vessel passes by. Possible effects 
of a multibeam echosounder on marine mammals are described below.
    Masking--Marine mammal communications will not be masked 
appreciably by the multibeam echosounder signals given the low duty 
cycle of the echosounder and the brief period when an individual mammal 
is likely to be within its beam. Furthermore, in the case of baleen 
whales, the multibeam 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 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 second tonal signals at frequencies similar 
to those that will be emitted by the multibeam echosounder used by NSF 
and ASC, 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 multibeam 
echosounder.
    Hearing Impairment and Other Physical Effects--Given several 
stranding events that have been associated with the operation of naval 
sonar in specific circumstances, there is concern that mid-frequency 
sonar sounds can cause serious impacts to marine mammals (see above). 
However, the multibeam echosounder proposed for use by NSF and ASC is 
quite different than sonar used for Navy operations. Pulse duration of 
the multibeam 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 multibeam 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 
multibeam 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 in 
this particular case is not likely to result in the harassment of 
marine mammals.

Single-Beam Echosounder

    NSF and ASC will operate the Knudsen 3260 and Bathy 2000 single-
beam echosounders from the source vessel during the planned study. 
Sounds from the single-beam echosounder are very short pulses, 
depending on water depth. Most of the energy in the sound pulses 
emitted by the singlebeam echosounder is at frequencies near 12 kHz for 
bottom-tracking purposes or at 3.5 kHz in the sub-bottom profiling 
mode. The sonar emits energy in a 30[deg] beam from the bottom of the 
ship. Marine mammals that encounter the Simrad EM120 are unlikely to be 
subjected to repeated pulses because of the narrow fore-aft width of 
the beam and will receive only limited amounts of pulse energy because 
of the short pulses. Animals close to the ship (where the beam is 
narrowest) are especially unlikely to be ensonified for more than one 
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 multibeam 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 Simrad EM120; and (2) are often directed close to horizontally 
versus more downward for the echosounder. The area of possible 
influence of the single-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 NSF and ASC's 
operations, the individual pulses will be very short, and a given 
mammal would not receive many of the downward-directed pulses as the 
vessel passes by. Possible effects of a single-beam echosounder on 
marine mammals are described below.
    Masking--Marine mammal communications will not be masked 
appreciably by the single-beam echosounder signals given the low duty 
cycle of the echosounder and the brief period when an individual mammal 
is likely to be within its beam. Furthermore, in the case of baleen 
whales, the single-beam echosounder signals (12 or 3.5 kHz) do not 
overlap with the predominant frequencies in the calls, which would 
avoid any significant masking.
    Behavioral Responses--Behavioral reactions of free-ranging marine 
mammals to sonars, echosounders, and other sound sources appear to vary 
by species and circumstance. Observed reactions have included silencing 
and dispersal by sperm whales (Watkins et al., 1985), increased 
vocalizations and no dispersal by pilot whales (Rendell and Gordon, 
1999), and the previously-mentioned beachings by beaked whales. During 
exposure to a 21 to 25 kHz ``whale-finding'' sonar with a source level 
of 215 dB re 1 [micro]Pa, gray whales reacted by orienting slightly 
away from the source and being deflected from their course by 
approximately 200 m (656.2 ft) (Frankel, 2005). When a 38 kHz 
echosounder and a 150 kHz ADCP were transmitting during studies in the 
Eastern Tropical Pacific, baleen whales

[[Page 481]]

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 second tonal signals at frequencies similar 
to those that will be emitted by the single-beam echosounder used by 
NSF and ASC, 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 single-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 single-beam 
echosounder proposed for use by NSF and ASC is quite different than 
sonar used for Navy operations. Pulse duration of the single-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 
single-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 single-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 single-beam echosounder in 
this particular case is not likely to result in the harassment of 
marine mammals.

Acoustic Doppler Current Profilers

    NSF and ASC will operate the ADCP Teledyne RDI VM-150 and ADCP 
Ocean Surveyor OS-38 from the source vessel during the planned study. 
Most of the energy in the sound pulses emitted by the ADCPs operate at 
frequencies near 150 kHz, and the maximum source level is 223.6 dB re 1 
[mu]Pa (rms). Sound energy from the ADCP is emitted as a 30[deg] 
conically-shaped beam. Marine mammals that encounter the ADCPs are 
unlikely to be subjected to repeated pulses because of the narrow fore-
aft width of the beam and will receive only limited amounts of pulse 
energy because of the short pulses. Animals close to the ship (where 
the beam is narrowest) are especially unlikely to be ensonified for 
more than one 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 the ADCPs 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 ADCPs; and (2) are often directed close to horizontally versus more 
downward for the ADCPs. The area of possible influence of the multibeam 
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 NSF and ASC's operations, the individual 
pulses will be very short, and a given mammal would not receive many of 
the downward-directed pulses as the vessel passes by. Possible effects 
of the ADCPs on marine mammals are described below.
    Masking--Marine mammal communications will not be masked 
appreciably by the ADCP signals given the low duty cycle of the ADCPs 
and the brief period when an individual mammal is likely to be within 
its beam. Furthermore, in the case of baleen whales, the ADCP signals 
(150 kHz) do not overlap with the predominant frequencies in the calls, 
which would avoid any significant masking.
    Behavioral Responses--Behavioral reactions of free-ranging marine 
mammals to sonars, echosounders, and other sound sources appear to vary 
by species and circumstance. Observed reactions have included silencing 
and dispersal by sperm whales (Watkins et al., 1985), increased 
vocalizations and no dispersal by pilot whales (Rendell and Gordon, 
1999), and the previously-mentioned beachings by beaked whales. During 
exposure to a 21 to 25 kHz ``whale-finding'' sonar with a source level 
of 215 dB re 1 [micro]Pa, gray whales reacted by orienting slightly 
away from the source and being deflected from their course by 
approximately 200 m (656.2 ft) (Frankel, 2005). When a 38 kHz 
echosounder and a 150 kHz ADCP 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 second tonal signals at frequencies similar 
to those that will be emitted by the multibeam echosounder used by NSF 
and ASC, 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 multibeam 
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 multibeam 
echosounder proposed for use by NSF and ASC is quite different than 
sonar used for Navy operations. Pulse duration of the ADCP is very 
short relative to the naval sonar. Also, at any given location, an 
individual marine mammal would be in the beam of the multibeam 
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 multibeam 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 in 
this particular case is not likely to result in the harassment of 
marine mammals.

Acoustic Locator

    NSF and ASC will operate the acoustic locator from the source 
vessel during the planned study during sampling. Sounds from the 
locator are very short pulses, occurring for 5 ms. Most of the energy 
in the sound pulses emitted by the acoustic locator is at frequencies 
near 12 kHz, and the maximum source level is 162 dB re 1 [mu]Pa (rms). 
Animals close to the ship (where the beam is narrowest) are especially 
unlikely to be ensonified for more than one 5 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

[[Page 482]]

multibeam 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.
    Masking--Marine mammal communications will not be masked 
appreciably by the acoustic locator signals given the low duty cycle 
and the low source level. Furthermore, in the case of baleen whales, 
the acoustic locator signals (12 kHz) do not overlap with the 
predominant frequencies in the calls, which would avoid any significant 
masking.
    Behavioral Responses--Behavioral reactions of free-ranging marine 
mammals to sonars, echosounders, and other sound sources appear to vary 
by species and circumstance. Observed reactions have included silencing 
and dispersal by sperm whales (Watkins et al., 1985), increased 
vocalizations and no dispersal by pilot whales (Rendell and Gordon, 
1999), and the previously-mentioned beachings by beaked whales. During 
exposure to a 21 to 25 kHz ``whale-finding'' sonar with a source level 
of 215 dB re 1 [micro]Pa, gray whales reacted by orienting slightly 
away from the source and being deflected from their course by 
approximately 200 m (656.2 ft) (Frankel, 2005). When a 38 kHz 
echosounder and a 150 kHz ADCP 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).
    NMFS believes that the brief exposure of marine mammals to one 
pulse, or small numbers of signals, from the acoustic locator is not 
likely to result in the harassment of marine mammals.

Core and Dredge Sampling

    During coring and dredging, the noise created by the mechanical 
action of the devices on the seafloor is expected to be perceived by 
nearby fish and other marine organisms and deter them from swimming 
toward the source. Coring and dredging activities would be highly 
localized and short-term in duration and would not be expected to 
significantly interfere with marine mammal behavior. The potential 
direct effects include temporary localized disturbance or displacement 
from associated sounds and/or physical movement/actions of the 
operations. Additionally, the potential indirect effects may consist of 
very localized and transitory/short-term disturbance of bottom habitat 
and associated prey in shallow-water areas as a result of coring, 
dredging, and sediment sampling (NSF/USGS PEIS, 2011). NMFS believes 
that the brief exposure of marine mammals to noise created from the 
mechanical action of the devices for core and dredge sampling is not 
likely to result in the harassment of marine mammals.

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 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

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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 Palmer will be audible to 
marine mammals over a large distance, it is unlikely that marine 
mammals will 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 
Palmer'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).
    NSF and ASC's proposed operation of one source vessel for the 
proposed low-energy seismic survey is relatively small in scale 
compared to the number of commercial ships transiting at higher speeds 
in the same areas on an annual basis. The probability of vessel and 
marine mammal interactions occurring during the proposed low-energy 
seismic survey is unlikely due to the Palmer's slow operational speed, 
which is typically 5 kts. Outside of seismic operations, the Palmer's 
cruising speed would be approximately 10.1 to 14.5 kts, 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 Palmer has a number of other advantages for 
avoiding ship strikes as compared to most commercial merchant vessels, 
including the following: the Palmer's bridge and aloft observation 
tower offers good visibility to visually monitor for marine mammal 
presence; PSOs posted during operations scan the ocean for marine 
mammals and must report visual alerts of marine mammal presence to 
crew; and the PSOs receive extensive training that covers the 
fundamentals of visual observing for marine mammals and information 
about marine mammals and their identification at sea.

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 low-energy seismic survey would require 
towing approximately a single 100 m cable streamer. This large of an 
array carries the risk of entanglement for marine mammals. Wildlife, 
especially slow moving individuals, such as large whales, have a low 
probability of becoming entangled due to slow speed of the survey 
vessel and onboard monitoring efforts. In May 2011, there was one 
recorded entanglement of an olive ridley sea turtle (Lepidochelys 
olivacea) in the R/V Marcus G. Langseth's barovanes after the 
conclusion of a seismic survey off Costa Rica. There have been cases of 
baleen whales, 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.

Icebreaking Activities

    Icebreakers produce more noise while breaking ice than ships of 
comparable size due, primarily, to the sounds of propeller cavitating 
(Richardson et al., 1995). Multi-year ice, which is expected to be 
encountered in the proposed survey area. Icebreakers commonly back and 
ram into heavy ice until losing momentum to make way. The highest noise 
levels usually occur while backing full astern in preparation to ram 
forward through the ice. Overall the noise generated by an icebreaker 
pushing ice was 10 to 15 dB greater than the noise produced by the ship 
underway in open water (Richardson et al., 1995). In general, the 
Antarctic and Southern Ocean is a noisy environment. Calving and 
grounding icebergs as well as the break-up of ice sheets, can produce a 
large amount of underwater noise. Little information is available about 
the increased sound levels due to icebreaking.
    Cetaceans--Few studies have been conducted to evaluate the 
potential interference of icebreaking noise with marine mammal 
vocalizations. Erbe and Farmer (1998) measured masked hearing 
thresholds of a captive beluga whale. They reported that the recording 
of a CCG ship, Henry Larsen, ramming ice in the Beaufort Sea, masked 
recordings of beluga vocalizations at a noise to signal pressure ratio 
of 18 dB, when the noise pressure level was eight times as high as the 
call pressure. Erbe and Farmer (2000) also predicted when icebreaker 
noise would affect beluga whales through software that combined a sound 
propagation model and beluga whale impact threshold models. They again 
used the data from the recording of the Henry Larsen in the Beaufort 
Sea and predicted that masking of beluga whale vocalizations could 
extend between 40 and 71 km (21.6 and 38.3 nmi) near the surface. 
Lesage et al. (1999) report that beluga whales changed their call type 
and call frequency when exposed to boat noise. It is possible that the 
whales adapt to the ambient noise levels and are able to communicate 
despite the sound. Given the documented reaction of belugas to ships 
and icebreakers it is highly unlikely that beluga whales would remain 
in the proximity of vessels where vocalizations would be masked.
    Beluga whales have been documented swimming rapidly away from ships 
and icebreakers in the Canadian high Arctic when a ship approaches to 
within 35 to 50 km (18.9 to 27 nmi), and they may travel up to 80 km 
(43.2 nmi) from the vessel's track (Richardson et al., 1995). It is 
expected that belugas avoid

[[Page 484]]

icebreakers as soon as they detect the ships (Cosens and Dueck, 1993). 
However, the reactions of beluga whales to ships vary greatly and some 
animals may become habituated to high levels of ambient noise (Erbe and 
Darmber, 2000).
    There is little information about the effects of icebreaking ships 
on baleen whales. Migrating bowhead whales appeared to avoid an area 
around a drill site by greater than 25 km (13.5 mi) where an icebreaker 
was working in the Beaufort Sea. There was intensive icebreaking daily 
in support of the drilling activities (Brewer et al., 1993). Migrating 
bowheads also avoided a nearby drill site at the same time of year 
where little icebreaking was being conducted (LGL and Greeneridge, 
1987). It is unclear as to whether the drilling activities, icebreaking 
operations, or the ice itself might have been the cause for the whale's 
diversion. Bowhead whales are not expected to occur in the proximity of 
the proposed action area.
    Pinnipeds--Brueggeman et al. (1992) reported on the reactions of 
seals to an icebreaker during activities at two prospects in the 
Chukchi Sea. Reactions of seals to the icebreakers varied between the 
two prospects. Most (67%) seals did not react to the icebreaker at 
either prospect. Reaction at one prospect was greatest during 
icebreaking activity (running/maneuvering/jogging) and was 0.23 km 
(0.12 nmi) of the vessel and lowest for animals beyond 0.93 km (0.5 
nmi). At the second prospect however, seal reaction was lowest during 
icebreaking activity with higher and similar levels of response during 
general (non-icebreaking) vessel operations and when the vessel was at 
anchor or drifting. The frequency of seal reaction generally declined 
with increasing distance from the vessel except during general vessel 
activity where it remained consistently high to about 0.46 km (0.25 
nmi) from the vessel before declining.
    Similarly, Kanik et al. (1980) found that ringed (Pusa hispida) and 
harp seals (Pagophilus groenlandicus) often dove into the water when an 
icebreaker was breaking ice within 1 km (0.5 nmi) of the animals. Most 
seals remained on the ice when the ship was breaking ice 1 to 2 km (0.5 
to 1.1 nmi) away.
    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 
adverse 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 airgun operations during the 
proposed low-energy 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 will be temporarily elevated noise levels and the associated 
direct effects on marine mammals in any particular area of the 
approximately 5,628 km\2\ proposed project area, previously discussed 
in this notice.
    The Palmer is designed for continuous passage at 3 kts through ice 
1 m thick. During the proposed project the Palmer will typically 
encounter first- or second-year ice while avoiding thicker ice floes, 
particularly large intact multi-year ice, whenever possible. In 
addition, the vessel will follow leads when possible while following 
the survey route. As the vessel passes through the ice, the ship causes 
the ice to part and travel alongside the hull. This ice typically 
returns to fill the wake as the ship passes. The effects are transitory 
(i.e., hours at most) and localized (i.e., constrained to a relatively 
narrow swath perhaps 10 m (32.1 ft) to each side of the vessel. The 
Palmer's maximum beam is 18.3 m (60 ft). Applying the maximum estimated 
amount of icebreaking (1,000 km), to the corridor opened by the ship, 
NSF and ASC anticipate that a maximum of approximately 18 km\2\ (5.3 
nmi\2\) of ice may be disturbed. This represents an inconsequential 
amount of the total ice present in the Southern Ocean.
    Sea ice is important for pinniped life functions such as resting, 
breeding, and molting. Icebreaking activities may damage seal breathing 
holes and will also reduce the haul-out area in the immediate vicinity 
of the ship's track. Icebreaking along a maximum of 1,000 km of 
trackline will alter local ice conditions in the immediate vicinity of 
the vessel. This has the potential to temporarily lead to a reduction 
of suitable seal haul-out habitat. However, the dynamic sea-ice 
environment requires that seals be able to adapt to changes in sea, 
ice, and snow conditions, and they therefore create new breathing holes 
and lairs throughout the winter and spring (Hammill and Smith, 1989). 
In addition, seals often use open leads and cracks in the ice to 
surface and breathe (Smith and Stirling, 1975). Disturbance of the ice 
will occur in a very small area relative to the Southern Ocean ice-pack 
and no significant impact on marine mammals is anticipated by 
icebreaking during the proposed low-energy seismic 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

[[Page 485]]

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 NSF, ASC, 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 will 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 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.
    For a proposed seismic survey in Southern California, USGS (1999) 
conducted a review of the literature on the effects of airguns on fish 
and fisheries. They reported a 1991 study of the Bay Area Fault system 
from the continental shelf to the Sacramento River, using a 10 airgun 
(5,828 in\3\) array. Brezzina and Associates were hired by USGS to 
monitor the effects of the surveys and concluded that airgun operations 
were not responsible for the death of any of the fish carcasses 
observed. They also concluded that the airgun profiling did not appear 
to alter the feeding behavior of sea lions, seals, or pelicans observed 
feeding during the seismic surveys.
    Some studies have reported, some equivocally, that mortality of 
fish, fish eggs, or larvae can occur close to seismic sources 
(Kostyuchenko, 1973; Dalen and Knutsen, 1986; Booman et al., 1996; 
Dalen et al., 1996). Some of the reports claimed seismic effects from 
treatments quite different from actual seismic survey sounds or even 
reasonable surrogates. However, Payne et al. (2009) reported no 
statistical differences in mortality/morbidity between control and 
exposed groups of capelin eggs or monkfish larvae. Saetre and Ona 
(1996) applied a `worst-case scenario' mathematical model to 
investigate the effects of seismic energy on fish eggs and larvae. They 
concluded that mortality rates caused by exposure to seismic surveys 
are so low, as compared to natural mortality rates, that the impact of 
seismic surveying on recruitment to a fish stock must be regarded as 
insignificant.
    Physiological Effects--Physiological effects refer to cellular and/
or biochemical responses of fish to acoustic stress. Such stress 
potentially could affect fish populations by increasing mortality or 
reducing reproductive success. Primary and secondary stress responses 
of fish after exposure to seismic survey sound appear to be temporary 
in all studies done to date (Sverdrup et al., 1994; Santulli et al., 
1999; McCauley et al., 2000a, b). The periods necessary for the 
biochemical changes to return to normal are variable and depend on 
numerous aspects of the biology of the species and of the sound 
stimulus.
    Behavioral Effects--Behavioral effects include changes in the 
distribution, migration, mating, and catchability of fish populations. 
Studies investigating the possible effects of sound (including seismic 
survey sound) on fish behavior have been conducted on both uncaged and 
caged individuals (e.g., Chapman and Hawkins, 1969; Pearson et al., 
1992; Santulli et al., 1999; Wardle et al., 2001; Hassel et al., 2003). 
Typically, in these studies fish exhibited a sharp startle response at 
the onset of a sound followed by habituation and a return to normal 
behavior after the sound ceased.

[[Page 486]]

    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 
testing. Fishes not dispersing from the airgun noise (e.g., demersal 
species) may startle and move short distances to avoid airgun 
emissions.
    In general, any adverse effects on fish behavior or fisheries 
attributable to seismic testing may depend on the species in question 
and the nature of the fishery (season, duration, fishing method). They 
may also depend on the age of the fish, its motivational state, its 
size, and numerous other factors that are difficult, if not impossible, 
to quantify at this point, given such limited data on effects of 
airguns on fish, particularly under realistic at-sea conditions.

Anticipated Effects on Invertebrates

    The existing body of information on the impacts of seismic survey 
sound on marine invertebrates is very limited. However, there is some 
unpublished and very limited evidence of the potential for adverse 
effects on invertebrates, thereby justifying further discussion and 
analysis of this issue. The three types of potential effects of 
exposure to seismic surveys on marine invertebrates are pathological, 
physiological, and behavioral. Based on the physical structure of their 
sensory organs, marine invertebrates appear to be specialized to 
respond to particle displacement components of an impinging sound field 
and not to the pressure component (Popper et al., 2001).
    The only information available on the impacts of seismic surveys on 
marine invertebrates involves studies of individuals; there have been 
no studies at the population scale. Thus, available information 
provides limited insight on possible real-world effects at the regional 
or ocean scale. The most important aspect of potential impacts concerns 
how exposure to seismic survey sound ultimately affects invertebrate 
populations and their viability, including availability to fisheries.
    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 NSF/USGS's 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 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 1575 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 1575 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, than 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

[[Page 487]]

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.
    NSF and ASC reviewed the following source documents and have 
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 recently 
completed ``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;''
    (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 activities, NSF, ASC and/or its designees have 
proposed to implement the following mitigation measures for marine 
mammals:
    (1) Proposed exclusion zones around the sound source;
    (2) Speed and course alterations;
    (3) Shut-down procedures; and
    (4) Ramp-up procedures.
    Proposed Exclusion Zones--During pre-planning of the cruise, the 
smallest airgun array was identified that could be used and still meet 
the geophysical scientific objectives. NSF and ASC use radii to 
designate exclusion and buffer zones and to estimate take for marine 
mammals. Table 2 (presented earlier in this document) shows the 
distances at which one would expect to receive three sound levels (160, 
180, and 190 dB) from the two GI airgun array. The 180 and 190 dB level 
shut-down criteria are applicable to cetaceans and pinnipeds, 
respectively, as specified by NMFS (2000). NSF and ASC used these 
levels to establish the exclusion and buffer zones.
    Received sound levels have been modeled by L-DEO for a number of 
airgun configurations, including two 45 in\3\ Nucleus G airguns, in 
relation to distance and direction from the airguns (see Figure 2 of 
the IHA application). In addition, propagation measurements of pulses 
from two GI airguns have been reported for shallow water (approximately 
30 m [98.4 ft] depth in the GOM (Tolstoy et al., 2004). However, 
measurements were not made for the two GI airguns in deep water. The 
model does not allow for bottom interactions, and is most directly 
applicable to deep water. Based on the modeling, estimates of the 
maximum distances from the GI airguns where sound levels are predicted 
to be 190, 180, and 160 dB re 1 [mu]Pa (rms) in shallow, intermediate, 
and deep water were determined (see Table 2 above).
    Empirical data concerning the 190, 180, and 160 dB (rms) distances 
were acquired for various airgun arrays based on measurements during 
the acoustic verification studies conducted by L-DEO in the northern 
GOM in 2003 (Tolstoy et al., 2004) and 2007 to 2008 (Tolstoy et al., 
2009). Results of the 36 airgun array are not relevant for the two GI 
airguns to be used in the proposed survey. The empirical data for the 
6, 10, 12, and 20 airgun arrays indicate that, for deep water, the L-
DEO model tends to overestimate the received sound levels at a given 
distance (Tolstoy et al., 2004). Measurements were not made for the two 
GI airgun array in deep water; however, NSF and ASC propose to use the 
safety radii predicted by L-DEO's model for the proposed GI airgun 
operations in shallow, intermediate, and deep water, although they are 
likely conservative given the empirical results for the other arrays.
    Based on the modeling data, the outputs from the pair of 45 in\3\ 
or 105 in\3\ GI airguns proposed to be used during the seismic survey 
are considered a low-energy acoustic source in the NSF/USGS PEIS (2011) 
for marine seismic research. A low-energy seismic source was defined in 
the NSF/USGS PEIS as an acoustic source whose received level at 100 m 
is less than 180 dB. The NSF/USGS PEIS also established for these low-
energy sources, a standard exclusion zone of 100 m for all low-energy 
sources in water depths greater than 100 m. This standard 100 m 
exclusion zone would be used during the proposed low-energy seismic 
survey. The 180 and 190 dB (rms) radii are shut-down criteria 
applicable to cetaceans and pinnipeds, respectively, as specified by 
NMFS (2000); these levels were used to establish exclusion zones. 
Therefore, the assumed 180 and 190 dB radii are 100 m for intermediate 
and deep water, respectively. If the PSO detects a marine mammal(s) 
within or about to enter the appropriate exclusion zone, the airguns 
will be shut-down immediately.
    Speed and Course Alterations--If a marine mammal is detected 
outside the exclusion zone and, based on its position and direction of 
travel (relative motion), is likely to enter the exclusion zone, 
changes of the vessel's speed and/or direct course will be considered 
if this does not compromise operational safety or damage the deployed 
equipment. This would be done if operationally practicable while 
minimizing the effect on the planned science objectives. For marine 
seismic surveys towing large streamer arrays, however, course 
alterations are not typically implemented due to the vessel's limited 
maneuverability. After any such speed and/or course alteration is 
begun, the marine mammal activities and movements relative to the 
seismic vessel will be closely monitored to ensure that the marine 
mammal does not approach within the exclusion zone. If the marine 
mammal appears likely to enter the exclusion zone, further mitigation 
actions will be taken, including further speed and/or course 
alterations, and/or shut-down of the airgun(s). Typically, during 
seismic operations, the source vessel is unable to change speed or 
course, and one or more alternative mitigation measures will need to be 
implemented.
    Shut-down Procedures--NSF and ASC will shut-down the operating 
airgun(s) if a marine mammal is detected outside the exclusion zone for 
the airgun(s), and if the vessel's speed and/or course cannot be 
changed to avoid having the animal enter the exclusion zone, the 
seismic source will be shut-down before the animal is within the 
exclusion zone. Likewise, if a marine mammal is already within the 
exclusion zone when first detected, the seismic source will be shut-
down immediately.
    Following a shut-down, NSF and ASC will not resume airgun activity 
until the marine mammal has cleared the exclusion zone. NSF and ASC 
will consider the animal to have cleared the exclusion zone if:

[[Page 488]]

     A PSO has visually observed the animal leave the exclusion 
zone, or
     A PSO has not sighted the animal within the exclusion zone 
for 15 minutes for species with shorter dive durations (i.e., small 
odontocetes and pinnipeds), or 30 minutes for species with longer dive 
durations (i.e., mysticetes and large odontocetes, including sperm, 
pygmy and dwarf sperm, killer, and beaked whales).
    Although power-down procedures are often standard operating 
practice for seismic surveys, they are not proposed to be used during 
this planned seismic survey because powering-down from two airguns to 
one airgun would make only a small difference in the exclusion 
zone(s)--but probably not enough to allow continued one-airgun 
operations if a marine mammal came within the exclusion zone for two 
airguns.
    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 avoiding any potential injury or impairment 
of their hearing abilities. NSF and ASC will follow a ramp-up procedure 
when the airgun array begins operating after a specified period without 
airgun operations or when a shut-down shut down has exceeded that 
period. NSF and ASC propose that, for the present cruise, this period 
would be approximately 15 minutes. SIO, L-DEO, and USGS have used 
similar periods (approximately 15 minutes) during previous low-energy 
seismic surveys.
    Ramp-up will begin with a single GI airgun (45 or 105 in\3\). The 
second GI airgun (45 or 105 in\3\) will be added after 5 minutes. 
During ramp-up, the PSOs will monitor the exclusion zone, and if marine 
mammals are sighted, a shut-down will be implemented as though both GI 
airguns 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, NSF and ASC will not commence the ramp-up. Given these 
provisions, it is likely that the airgun array will not be ramped-up 
from a complete shut-down at night or in thick fog, because the outer 
part of the exclusion zone for that array will not be visible during 
those conditions. If one airgun has operated, ramp-up to full power 
will be permissible at night or in poor visibility, on the assumption 
that marine mammals will be alerted to the approaching seismic vessel 
by the sounds from the single airgun and could move away if they 
choose. A ramp-up from a shut-down may occur at night, but only where 
the exclusion zone is small enough to be visible. NSF and ASC will not 
initiate a ramp-up of the airguns if a marine mammal is sighted within 
or near the applicable exclusion zones during the day or close to the 
vessel at night.
    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 adverse 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.
    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 adverse impacts 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 IHAs 
must include the suggested means of accomplishing the necessary 
monitoring and reporting that will result in increased knowledge of the 
species and of the level of taking or impacts on populations of marine 
mammals that are expected to be present in the action area.

Proposed Monitoring

    NSF and ASC 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. NSF and ASC's proposed 
``Monitoring Plan'' is described below this section. NSF and ASC 
understand that this monitoring plan will be subject to review by NMFS 
and that refinements may be required. 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 regions. NSF and ASC is prepared to discuss coordination of 
their monitoring program with any related work that might be done by 
other groups insofar as this is practical and desirable.

Vessel-Based Visual Monitoring

    PSOs will be based aboard the seismic source vessel and will watch 
for marine mammals near the vessel during icebreaking activities, 
daytime airgun operations (austral summer) and during any ramp-ups of 
the airguns at night. Nighttime operations of the airguns are not 
anticipated. PSOs will also watch for marine mammals near the seismic 
vessel for at least 30 minutes prior to the start of airgun operations 
and after an extended shut-down (i.e., greater than approximately 15 
minutes for this proposed low-energy seismic survey). When feasible, 
PSOs will 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 PSO observations, the airguns 
will be shut-down when marine mammals are observed within or about to 
enter a designated exclusion zone. The exclusion zone is a region in 
which a possibility exists of adverse effects on animal hearing or 
other physical effects.
    During seismic operations in the Dumont d'Urville Sea of the 
Southern Ocean, at least two PSOs will be based aboard the Palmer. At 
least one PSO will stand watch at all times while the Palmer is 
operating airguns during the proposed low-energy seismic survey; this 
procedure will also be followed when the vessel is conducting 
icebreaking during transit. NSF and ASC will appoint the PSOs with 
NMFS's concurrence. The lead PSO would be experienced with marine 
mammal species in the Southern Ocean, the second PSO would receive 
additional specialized training from the PSO to ensure that they can 
identify marine mammal species commonly found in the Southern Ocean. 
Observations will take place during ongoing daytime operations and 
nighttime ramp-ups of the airguns.

[[Page 489]]

During the majority of seismic operations, at least one PSO will be on 
duty from observation platforms (i.e., the best available vantage point 
on the source vessel) to monitor marine mammals near the seismic 
vessel. PSO(s) will be on duty in shifts no longer than 4 hours in 
duration. Other crew will also be instructed to assist in detecting 
marine mammals and implementing mitigation requirements (if practical). 
Before the start of the low-energy seismic survey, the crew will be 
given additional instruction on how to do so. (Note: because of the 
high latitude locations of the study areas, twilight/darkness 
conditions are expected to be limited to between 3 and 6 hours per day 
during the proposed action.)
    The Palmer is a suitable platform for marine mammal observations 
and will serve as the platform from which PSOs will watch for marine 
mammals before and during seismic operations. Two locations are likely 
as observation stations onboard the Palmer. Observing stations are 
located on the bridge level, with the PSO eye level at approximately 
16.5 m (54.1 ft) above the waterline and the PSO would have a good view 
around the entire vessel. In addition, there is an aloft observation 
tower for the PSO approximately 24.4 m (80.1 ft) above the waterline 
that is protected from the weather, and affords PSOs an even greater 
view. Standard equipment for PSOs will be reticle binoculars. Night-
vision equipment will not be available or required due to the constant 
daylight conditions during the Antarctic summer. The PSOs will be in 
communication with ship's officers on the bridge and scientists in the 
vessel's operations laboratory, so they can advise promptly of the need 
for avoidance maneuvers or seismic source shut-down. Observing stations 
will be at the bridge level and the aloft observation tower. The 
approximate view around the vessel from the bridge is 270[deg] and 
360[deg] from the aloft observation tower. During daytime, the PSO(s) 
will scan the area around the vessel systematically with reticle 
binoculars (e.g., 7 x 50 Fujinon FMTRC-SX) and the naked eye. These 
binoculars will have a built-in daylight compass. Estimating distances 
is done primarily with the reticles in the binoculars. The PSO(s) will 
be in direct (radio) wireless communication with ship's officers on the 
bridge and scientists in the vessel's operations laboratory during 
seismic operations, so they can advise the vessel operator, science 
support personnel, and the science party promptly of the need for 
avoidance maneuvers or a shut-down of the seismic source. PSOs will 
monitor for the presence pinnipeds and cetaceans during icebreaking 
activities, and will be limited to those marine mammal species in 
proximity to the ice margin habitat. Observations within the buffer 
zone would also include pinnipeds that may be present on the surface of 
the sea ice (i.e., hauled-out) and that could potentially dive into the 
water as the vessel approaches, indicating disturbance from noise 
generated by icebreaking activities).
    When marine mammals are detected within or about to enter the 
designated exclusion zone, the airguns will immediately be shut-down if 
necessary. The PSO(s) will continue to maintain watch to determine when 
the animal(s) are outside the exclusion zone by visual confirmation. 
Airgun operations will 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, killer, and beaked whales).

PSO Data and Documentation

    PSOs will 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 will be used to estimate 
numbers of animals potentially ``taken'' by harassment (as defined in 
the MMPA). They will also provide information needed to order a shut-
down of the airguns when a marine mammal is within or near the 
exclusion zone. Observations will also be made during icebreaking 
activities as well as daytime periods when the Palmer is underway 
without seismic operations (i.e., transits, to, from, and through the 
study area) to collect baseline biological data.
    When a sighting is made, the following information about the 
sighting will 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 seismic source or vessel (e.g., none, 
avoidance, approach, paralleling, etc.), and behavioral pace.
    2. Time, location, heading, speed, activity of the vessel, sea 
state, wind force, visibility, and sun glare.
    The data listed under (2) will 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, as well as information regarding ramp-ups or 
shut-downs will be recorded in a standardized format. Data will be 
entered into an electronic database. The data accuracy will be verified 
by computerized data validity checks as the data are entered and by 
subsequent manual checking of the database by the PSOs at sea. These 
procedures will allow initial summaries of data to be prepared during 
and shortly after the field program, and will facilitate transfer of 
the data to statistical, graphical, and other programs for further 
processing and archiving.
    Results from the vessel-based observations will provide the 
following information:
    1. The basis for real-time mitigation (airgun 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.
    NSF and ASC will submit a comprehensive report to NMFS within 90 
days after the end of the cruise. The report will describe the 
operations that were conducted and sightings of marine mammals near the 
operations. The report submitted to NMFS will provide full 
documentation of methods, results, and interpretation pertaining to all 
monitoring. The 90-day report will summarize the dates and locations of 
seismic operations and all marine mammal sightings (i.e., dates, times, 
locations, activities, and associated seismic survey activities). The 
report will 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 other factors affecting 
visibility and detectability of marine mammals;
     Analyses of the effects of various factors influencing 
detectability of marine mammals including Beaufort sea state, number of 
PSOs, and fog/glare;
     Species composition, occurrence, and distribution of 
marine mammals sightings including date, water depth,

[[Page 490]]

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 will 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 
will be publicly available on the NMFS Web site at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#iha.
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by this IHA, 
such as an injury (Level A harassment), serious injury or mortality 
(e.g., ship-strike, gear interaction, and/or entanglement), NSF and ASC 
will 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 
[email protected] and [email protected]. The report must 
include the following information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Name and type of vessel involved;
     Vessel's speed during and leading up to the incident;
     Description of the incident;
     Status of all sound source use in the 24 hours preceding 
the incident;
     Water depth;
     Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS shall work with NSF and ASC 
to determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. NSF and ASC may not resume 
their activities until notified by NMFS via letter or email, or 
telephone.
    In the event that NSF and ASC 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), 
NSF and ASC 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 [email protected] and 
[email protected]. The report must include the same information 
identified in the paragraph above. Activities may continue while NMFS 
reviews the circumstances of the incident. NMFS will work with NSF and 
ASC to determine whether modifications in the activities are 
appropriate.
    In the event that NSF and ASC 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 the IHA 
(e.g., previously wounded animal, carcass with moderate or advanced 
decomposition, or scavenger damage), NSF and ASC will 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 
[email protected] and [email protected], within 24 hours 
of discovery. NSF and ASC will provide photographs or video footage (if 
available) or other documentation of the stranded animal sighting to 
NMFS. 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].
    Level B harassment is anticipated and proposed to be authorized as 
a result of the proposed low-energy marine seismic survey in the Dumont 
d'Urville Sea off the coast of East Antarctica. Acoustic stimuli (i.e., 
increased underwater sound) generated during the operation of the 
seismic airgun array and icebreaking activities are expected to result 
in the behavioral disturbance of some marine mammals. There is no 
evidence that the planned activities could result in injury, serious 
injury, or mortality for which NSF and ASC seeks the IHA. The required 
mitigation and monitoring measures will minimize any potential risk for 
injury, serious injury, or mortality.
    The following sections describe NSF and ASC's methods to estimate 
take by incidental harassment and present the applicant's estimates of 
the numbers of marine mammals that could be affected during the 
proposed low-energy seismic survey in the Dumont d'Urville Sea off the 
coast of East Antarctica. The estimates are based on a consideration of 
the number of marine mammals that could be harassed by approximately 
2,800 km (1511.9 nmi) of seismic operations with the two GI airgun 
array to be used and 1,000 km of icebreaking activities.
    During simultaneous operations of the airgun array and the other 
sound sources, any marine mammals close enough to be affected by the 
single and multi-beam echosounders, pingers, ADCP, sub-bottom profiler, 
etc. would already be affected by the airguns. During times when the 
airguns are not operating, it is unlikely that marine mammals will 
exhibit more than minor, short-term responses to the echosounders, 
ADCPs, and sub-bottom profiler given their characteristics (e.g., 
narrow, downward-directed beam) and other considerations described 
previously. Therefore, for this activity, take was not authorized 
specifically for these sound sources beyond that which is already 
authorized for airguns and icebreaking activities.
    There are no stock assessments and very limited population 
information available for marine mammals in the Dumont d'Urville Sea. 
Sighting data from the Australian Antarctic Division's (AAD) BROKE-West 
surveys (Southwell et al., 2008; 2012) was used to determine and 
estimate marine mammals densities for mysticetes and odontocetes and 
AAD data components for pinnipeds, which were not available for the 
proposed seismic survey's action area in the Dumont d'Urville Sea. 
While population density data for cetaceans in the Southern Ocean is 
sparse to nonexistent, reported sightings data from previous research 
cruises suggest cetaceans such as those identified in Table 12 of the 
IHA application span a range greater than 4,000 km (2,159.8 nmi) off 
the coast of East Antarctica.

[[Page 491]]

The AAD BROKE-West survey was not specifically designed to quantify 
marine mammals. The data was in terms of animals sighted per time unit, 
and this sighting data was then converted to an areal density by 
multiplying the number of animals observed by the estimated area 
observed during the survey. As such, some marine mammals that were 
present in the area may not have been observed.
    The estimated number of cetaceans and pinnipeds that may be 
potentially exposed from the proposed seismic airgun operations and 
icebreaking activities based on sighting data from previous research 
cruises over a 52-day period and 13-day period. Some of the AAD 
sighting data was used as the basis for estimating take included 
``unidentified whale'' species, this category was retained and pro-
rated to the other species because environmental conditions may be 
present during the proposed action to limit identification of observed 
cetaceans. The estimated frequency of sightings data for cetaceans 
incorporates a correction factor of 5 that assumes only 20% of the 
animals present were reported due to sea ice and other conditions that 
may have hindered observation. The 20% factor was intended to 
conservatively account for this. Conservatively, a 40% correction 
factor was used for pinnipeds. The expected sightings data incorporates 
a 40% correction factor to account for seals that may be in the water 
versus those hauled-out on ice surface. This correction factor for 
pinnipeds was conservatively based on Southwell et al. (2012), which 
estimated 20 to 40% of crabeater seals may be in the water in a 
particular area while the rest are hauled-out. The correction factor 
takes into consideration some pinnipeds may not be observed due to poor 
visibility conditions.
    Sightings data were collected by the AAD; however, the AAD 
methodology was not described. Density is generally reported in the 
number of animals per km or square km. Estimated area observed by 
observers was calculated by using the average vessel speed (5.6 km/hr) 
times the estimated hours of the survey to estimate the total distance 
covered for each of the surveys. This was then converted from the 
linear distance into an area by assuming a width of 5 km that could be 
reliably visually surveyed. Therefore, the estimated area was 5,753 
km\2\ (1,677.3 nmi\2\) to obtain mysticete and odontocete densities and 
the estimated area was 1,419 km\2\ (413.7 nmi\2\) to obtain pinniped 
densities.
    Of the six species of pinnipeds that may be present in the study 
area during the proposed action, only four species are expected to be 
observed and occur mostly near pack ice or coastal areas and not 
prevalent in open sea areas where the low-energy seismic survey would 
be conducted. Because density estimates for pinnipeds in that Antarctic 
regions typically represent individuals that have hauled-out of the 
water, those estimates are not representative of individuals that are 
in the water and could be potentially exposed to underwater sounds 
during the seismic airgun operations and icebreaking activities; 
therefore, the pinniped densities have been adjusted to account for 
this concern. Take was not requested for southern elephant seals and 
Antarctic fur seals because preferred habitat for these species is not 
within the proposed action area. Although no sightings of Weddell seals 
and spectacled porpoises were reported in the BROKE-West sighting data, 
take was requested for these species based on NMFS recommendation and 
IWC SOWER data. Although there is some uncertainty about the 
representatives of the data and the assumptions used in the 
calculations below, the approach used here is believed to be the best 
available approach.
    Table 5. Estimated densities and possible number of marine mammal 
species that might be exposed to greater than or equal to 120 dB 
(icebreaking) and 160 dB (airgun operations) during NSF and ASC's 
proposed low-energy seismic survey (approximately 1,000 km of 
tracklines/approximately 3,500 km\2\ ensonified area for icebreaking 
activities and approximately 2,800 km of tracklines/approximately 5,628 
km\2\ ensonified area for airgun operations) in the Dumont d'Urville 
Sea of the Southern Ocean, February to March 2014.

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Calculated      Calculated
                                                                                 take from       take from
                                 Reported                                     seismic airgun    icebreaking
                               sightings 1 2     Corrected      Density in-      operations     activities      Approximate
                                *sightings       sightings    water [density      (i.e.,          (i.e.,       percentage of
                              have been pro-    (assume 20%    in-water and/     estimated       estimated      population       Total requested take
           Species               rated to     for cetaceans,    or on-ice]       number of       number of       estimate          authorization \6\
                                  include         40% of      (/km)    individuals     individuals     (calculated
                               unidentified    pinnipeds in         \2\         exposed to      exposed to      total take)
                                 animals*         water)                       sound levels    sound levels         \5\
                                                                               >=160 dB re 1   >=120 dB re 1
                                                                                [mu]Pa) \3\     [mu]Pa) \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mysticetes:
    Southern right whale....               0               0               0               0               0              NA  0.
    Humpback whale..........             238           1,190       0.2068400           1,165             724             5.4  1,165 + 724 = 1,889.
    Antarctic minke whale...             136             680       0.1181943             666             414             0.4  666 + 414 = 1,080.
    Sei whale...............               4              20       0.0034763              20              13            0.04  20 + 13 = 33.
    Fin whale...............             232           1,160       0.2016255           1,135             706             1.3  1,135 + 706 = 1,841.
    Blue whale..............               2              10       0.0017382              10               7             1.0  10 + 7 = 17.
Odontocetes:
    Sperm whale.............              32             160       0.0278104             157              98             2.7  157 + 98 = 255.
    Arnoux's beaked whale...               0               0               0               0               0              NA  0.
    Cuvier's beaked whale...               0               0               0               0               0              NA  0.
    Southern bottlenose                    0               0               0               0               0              NA  0.
     beaked whale.
    Killer whale............              62             310        0.538827             304             189             2.0  304 + 189 = 493.
    Long-finned pilot whale.              24             120       0.0208578             118              74             0.1  118 + 74 = 192.
    Hourglass dolphin.......              27             135       0.0234650             133              83            0.15  133 + 83 = 216.
    Spectacled porpoise.....              26             130       0.0225690             128              80              NA  128 + 80 = 208.
Pinnipeds:
    Crabeater seal..........           2,220             888        0.625546           3,521           7,663             0.2  3,521 + 7,663 = 11,184.
                                                                  [2.189411]
    Leopard seal............              17               7         0.00479              27              59            0.04  27 + 59 = 86.
                                                                  [0.016766]
    Ross seal...............              42              17        0.011835              66             145             0.2  66 + 145 = 211.
                                                                  [0.041421]

[[Page 492]]

 
    Weddell seal............             302             121           0.054             303             189             0.1  303 + 189 = 492.
                                                                     [0.054]
    Southern elephant seal..               0               0               0               0               0              NA  0.
    Antarctic fur seal......               0               0               0               0               0              NA  0.
--------------------------------------------------------------------------------------------------------------------------------------------------------
NA = Not available or not assessed.
\1\ Sightings from a 52 day (5,753 km\2\) period on the AAD BROKE-West survey during January to March 2006.
\2\ Sightings December 3 to 16, 1999 (1,420 km\2\ and 75,564 km\2\), below 60[deg] South latitude between 110 to 165[deg] East longitude. All sightings
  were animals hauled-out of the water and on the sea ice.
\3\ Calculated take is estimated density (reported density times correction factor) multiplied by the area ensonified to 160 dB (rms) around the planned
  seismic lines, increased by 25% for contingency.
\4\ Calculated take is estimated density (reported density) multiplied by the area ensonified to 120 dB (rms) around the planned transit lines where
  icebreaking activities may occur.
\5\ Total requested (and calculated) takes expressed as percentages of the species or regional populations.
\6\ Requested Take Authorization includes unidentified animals that were added to the observed and identified species on a pro-rated basis.
Note: Take was not requested for southern elephant seals and Antarctic fur seals because preferred habitat for these species is not within the proposed
  action area.

    Icebreaking in Antarctic waters will occur, as necessary, between 
the latitudes of approximately 66 to 70[deg] South and between 140 and 
165[deg] East. Based on a maximum sea ice extent of 250 km and 
estimating that the Palmer will transit to the innermost shelf and back 
into open water twice--a round trip transit in each of the potential 
work regions, it is estimated that the Palmer will actively break ice 
up to a distance of 1,000 km. Based on the ship's speed of 5 kts under 
moderate ice conditions, this distance represents approximately 108 hrs 
of icebreaking operations. This calculation is likely an overestimation 
because icebreakers often follow leads when they are available and thus 
do not break ice at all times.
    Numbers of marine mammals that might be present and potentially 
disturbed are estimated based on the available data about marine mammal 
distribution and densities in the Southern Ocean study are during the 
austral summer. NSF and ASC estimated the number of different 
individuals that may be exposed to airgun sounds with received levels 
greater than or equal to 160 dB re 1 [mu]Pa (rms) for seismic airgun 
operations and greater than or equal to 120 dB re 1 [mu]Pa (rms) for 
icebreaking activities on one or more occasions by considering the 
total marine area that would be within the 160 dB radius around the 
operating airgun array and 120 dB radius for the icebreaking activities 
on at least one occasion and the expected density of marine mammals in 
the area (in the absence of the a seismic survey and icebreaking 
activities). The number of possible exposures can be estimated by 
considering the total marine area that would be within the 160 dB 
radius (i.e., diameter is 1,005 m times 2) around the operating 
airguns. The ensonified area for icebreaking was estimated by 
multiplying the distance of the icebreaking activities (1,000 km) by 
the estimated diameter of the area within the 120 dB radius (i.e., 
diameter is 1,750 m times 2). The 160 dB radii are based on acoustic 
modeling data for the airguns that may be used during the proposed 
action (see Attachment B of the IHA application). As summarized in 
Table 2 (see Table 11 of the IHA application), the modeling results for 
the proposed low-energy seismic airgun array indicate the received 
levels are dependent on water depth. Since the majority of the proposed 
airgun operations would be conducted in waters 100 to 1,000 m deep, the 
buffer zone of 1,005 m used for the two 105 in\3\ GI airguns was used 
to be more conservative. The expected sighting data for pinnipeds 
accounts for both pinnipeds that may be in the water and those hauled-
out on ice surfaces. While the number of cetaceans that may be 
encountered within the ice margin habitat would be expected to be less 
than open water, the estimates utilized expected sightings for the open 
water and represent conservative estimates. It is unlikely that a 
particular animal would stay in the area during the entire survey.
    The number of different individuals potentially exposed to received 
levels greater than or equal to 160 dB re 1 [mu]Pa (rms) from seismic 
airgun operations and 120 dB re 1 [mu]Pa (rms) for icebreaking 
activities was calculated by multiplying:
    (1) The expected species density (in number/km\2\), times.
    (2) The anticipated area to be ensonified to that level during 
airgun operations.
    Applying the approach described above, approximately 5,628 km\2\ 
(including the 25% contingency) would be ensonified within the 160 dB 
isopleth for seismic airgun operations and approximately 3,500 km\2\ 
would be ensonified within the 120 dB isopleth for icebreaking 
activities on one or more occasions during the proposed survey. The 
take calculations within the study sites do not explicitly add animals 
to account for the fact that new animals (i.e., turnover) are not 
accounted for in the initial density snapshot and animals could also 
approach and enter the area ensonified above 160 dB for seismic airgun 
operations and 120 dB for icebreaking activities; however, studies 
suggest that many marine mammals will avoid exposing themselves to 
sounds at this level, which suggests that there would not necessarily 
be a large number of new animals entering the area once the seismic 
survey and icebreaking activities started. Because this approach for 
calculating take estimates 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 or pinnipeds will move away or 
toward the tracklines as the Palmer approaches in response to 
increasing sound levels before the levels reach 160 dB for seismic 
airgun operations and 120 dB for icebreaking activities. Another way of 
interpreting the

[[Page 493]]

estimates that follow is that they represent the number of individuals 
that are expected (in absence of a seismic and icebreaking program) to 
occur in the waters that will be exposed to greater than or equal to 
160 dB (rms) for seismic airgun operations and greater than or equal to 
120 dB (rms) for icebreaking activities.
    NSF and ASC's estimates of exposures to various sound levels assume 
that the proposed surveys will be carried out in full; however, the 
ensonified areas calculated using the planned number of line-kilometers 
has been increased by 25% to accommodate lines that may need to be 
repeated, equipment testing, etc. As is 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. The estimates of the numbers 
of marine mammals potentially exposed to 120 dB (rms) and 160 dB (rms) 
received levels are precautionary and probably overestimate the actual 
numbers of marine mammals that could be involved. These estimates 
assume that there will be no weather, equipment, or mitigation delays, 
which is highly unlikely.
    Table 5 shows the estimates of the number of different individual 
marine mammals anticipated to be exposed to greater than or equal to 
120 dB re 1 [mu]Pa (rms) for icebreaking activities and greater than or 
equal to 160 dB re 1 [mu]Pa (rms) for seismic airgun operations during 
the seismic survey if no animals moved away from the survey vessel. The 
total requested take authorization is given in the far right column of 
Table 5.
    The estimate of the number of individual cetaceans and pinnipeds 
that could be exposed to seismic sounds with received levels greater 
than or equal to 160 dB re 1 [mu]Pa (rms) and sounds from icebreaking 
activities with received levels greater than or equal to 120 dB re 1 
[mu]Pa (rms) during the proposed survey is (with 25% contingency) in 
Table 5 of this document. That total (with 25% contingency) includes 
1,889 humpback, 1,080 Antarctic minke, 33 sei, 1,841 fin, 17 blue, and 
255 sperm whales could be taken by Level B harassment during the 
proposed seismic survey, which would represent 5.4, 0.4, 0.04, 1.3, 1, 
and 2.7% of the worldwide or regional populations, respectively. Some 
of the cetaceans potentially taken by Level B harassment are delphinids 
and porpoises: killer whales, long-finned pilot whales, hourglass 
dolphins, and spectacled porpoises are estimated to be the most common 
delphinid and porpoise species in the area, with estimates of 493, 192, 
216, and 208, which would represent 2, 0.1, and 0.15% (spectacled 
porpoise population is not available) of the affected worldwide or 
regional populations, respectively. Most of the pinnipeds potentially 
taken by Level B harassment are: Crabeater, leopard, Ross, and Weddell 
seals with estimates of 11,184, 86, 211, and 492, which would represent 
0.2, 0.04, 0.2, and 0.1% of the affected worldwide or regional 
populations, respectively.

Encouraging and Coordinating Research

    NSF and ASC will coordinate the planned marine mammal monitoring 
program associated with the proposed low-energy seismic survey with 
other parties that express interest in this activity and area. NSF and 
ASC will coordinate with applicable U.S. agencies (e.g., NMFS), and 
will comply with their requirements. NSF has already reached out to the 
Australian Antarctic Division (AAD), who are the proponents of the 
proposed marine protected area and regularly conduct research 
expeditions in the marine environment off East Antarctica.
    The proposed action would complement fieldwork studying other 
Antarctic ice shelves, oceanographic studies, and ongoing development 
of ice sheet and other ocean models. It would facilitate learning at 
sea and ashore by students, help to fill important spatial and temporal 
gaps in a lightly sampled region of coastal Antarctica, provide 
additional data on marine mammals present in the East Antarctic study 
areas, and communicate its findings via reports, publications and 
public outreach.

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 will 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 in the 
study area (in the Dumont d'Urville Sea off the coast of East 
Antarctica) that implicate MMPA section 101(a)(5)(D).

Negligible Impact and Small Numbers Analysis Determination

    As a preliminary matter, NMFS typically includes our negligible 
impact and small numbers analyses and determinations under the same 
section heading of our Federal Register notices. Despite co-locating 
these terms, NMFS acknowledges that negligible impact and small numbers 
are distinct standards under the MMPA and treat them as such. The 
analyses presented below do not conflate the two standards; instead, 
each standard has been considered independently and NMFS has applied 
the relevant factors to inform our negligible impact and small numbers 
determinations.
    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.'' 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 potential for temporary or permanent hearing impairment is 
relatively low and would likely be avoided through the implementation 
of the shut-down measures;
    No injuries, serious injuries, or mortalities are anticipated to 
occur as a result of the NSF and ASC's planned low-energy marine 
seismic survey, and none are proposed to be authorized by NMFS. Table 5 
of this document outlines the number of requested Level B harassment 
takes that are anticipated as a result of these activities. Due to the

[[Page 494]]

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 NMFS's and the applicant's proposal to 
implement mitigation, monitoring, and reporting measures to minimize 
impacts to marine mammals. Additionally, the seismic survey will not 
adversely impact marine mammal habitat.
    For the other 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). Additionally, the seismic survey will be 
increasing sound levels in the marine environment in a relatively small 
area surrounding the vessel (compared to the range of the animals), 
which is constantly travelling over distances, and some animals may 
only be exposed to and harassed by sound for less than day.
    Of the 14 marine mammal species under NMFS jurisdiction that may or 
are known to likely to occur in the study area, five are listed as 
threatened or endangered under the ESA: southern right, humpback, sei, 
fin, blue, and sperm whales. These species are also considered depleted 
under the MMPA. Of these ESA-listed species, incidental take has been 
requested to be authorized for humpback, sei, fin, blue, and sperm 
whales. There is generally insufficient data to determine population 
trends for the other depleted species in the study area. To protect 
these animals (and other marine mammals in the study area), NSF and ASC 
must cease or reduce airgun operations if any marine mammal enters 
designated zones. No injury, serious injury, or mortality is expected 
to occur and due to the nature, degree, and context of the Level B 
harassment anticipated, and the activity is not expected to impact 
rates of recruitment or survival.
    As mentioned previously, NMFS estimates that 14 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 were 
provided in Table 4 of this document.
    NMFS's practice has been to apply the 160 dB re 1 [mu]Pa (rms) 
received level threshold for underwater impulse sound levels and the 
120 dB re 1 [mu]Pa (rms) received level threshold for icebreaking 
activities 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 low-energy marine seismic survey in the Dumont d'Urville 
Sea off the coast of East Antarctica, February to March 2014, may 
result, at worst, in a modification in behavior and/or low-level 
physiological effects (Level B harassment) of certain species of marine 
mammals.
    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 will have a negligible impact on the affected 
species in the specified geographic region. NMFS believes that the 
length of the seismic survey, the requirement to implement mitigation 
measures (e.g., shut-down of seismic operations), and the inclusion of 
the monitoring and reporting measures, will reduce the amount and 
severity of the potential impacts from the activity to the degree that 
it will have a negligible impact on the species or stocks in the action 
area.
    NMFS has preliminary determined, provided that the aforementioned 
mitigation and monitoring measures are implemented, that the impact of 
conducting a low-energy marine seismic survey in the Dumont d'Urville 
Sea off the coast of East Antarctica, January to March 2014, may 
result, at worst, in a temporary modification in behavior and/or low-
level physiological effects (Level B harassment) of small numbers of 
certain species of marine mammals. See Table 5 for the requested 
authorized take numbers 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 humpback, sei, fin, blue, and sperm whales. NSF and ASC did not 
request take of endangered Southern right whales due to the low 
likelihood of encountering this species during the cruise. Under 
section 7 of the ESA, NSF, on behalf of ASC and five other research 
institutions, 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 will conclude formal section 7 
consultation prior to making a determination on whether or not to issue 
the IHA. If the IHA is issued, NSF and ASC, in addition to the 
mitigation and monitoring requirements included in the IHA, will be 
required to comply with the Terms and Conditions of the Incidental Take 
Statement corresponding to NMFS's Biological Opinion issued to both NSF 
and ASC, and NMFS's Office of Protected Resources.

National Environmental Policy Act

    With NSF and ASC's complete application, NSF and ASC provided NMFS 
a ``Draft Initial Environmental Evaluation/Environmental Assessment to 
Conduct Marine-Based Studies of the Totten Glacier System and Marine 
Record of Cryosphere--Ocean Dynamics,'' (IEE/EA) prepared by AECOM on 
behalf of NSF and ASC. The IEE/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 will either prepare an independent EA, or, after review and 
evaluation of the NSF and ASC IEE/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 NSF and 
ASC IEE/EA and make a decision of whether or not to issue a

[[Page 495]]

Finding of No Significant Impact (FONSI).

Proposed Authorization

    As a result of these preliminary determinations, NMFS propose to 
issue an IHA to NSF and ASC for conducting the low-energy seismic 
survey in the tropical western Pacific Ocean, provided the previously 
mentioned mitigation, monitoring, and reporting requirements are 
incorporated. The proposed IHA language is provided below:
    National Science Foundation, Division of Polar Programs, 4201 
Wilson Boulevard, Arlington, Virginia 22230 and Antarctic Support 
Contract, 7400 South Tucson Way, Centennial, Colorado 80112, is hereby 
authorized 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 low-energy marine geophysical (seismic) survey 
conducted by the RVIB Nathaniel B. Palmer (Palmer) in the Dumont 
d'Urville Sea, Antarctica, January to March 2014:
    1. This Authorization is valid from January 29 through April 27, 
2014.
    2. This Authorization is valid only for the Palmer's activities 
associated with low-energy seismic survey operations that shall occur 
in the following specified geographic area:
    In selected regions of the Dumont d'Urville Sea in the Southern 
Ocean off the coast of East Antarctica and focus on the Totten Glacier 
and Moscow University Ice Shelf, located on the Sabrina Coast, from 
greater than approximately 64[deg] South and between approximately 95 
to 135[deg] East, and the Mertz Glacier and Cook Ice Shelf systems 
located on the George V and Oates Coast, from greater than 
approximately 65[deg] South and between approximately 140 to 165[deg] 
East. The study sites are characterized by heavy ice cover, with a 
seasonal break-up in the ice that structures biological patterns. The 
studies may occur in both areas, or entirely in one or the other, 
depending on ice conditions. Water depths in the survey area generally 
range from approximately 100 to 1,000 m, and possibly exceeding 1,000 m 
in some areas. The low-energy seismic survey will be conducted in 
International Waters (i.e., high seas), as specified in NSF and ASC's 
Incidental Harassment Authorization application and the associated NSF 
and ASC Initial Environmental Evaluation/Environmental Assessment (IEE/
EA).
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 Southern 
Ocean off the coast of East Antarctica:
    (i) Mysticetes--see Table 2 (attached) for authorized species and 
take numbers.
    (ii) Odontocetes--see Table 2 (attached) for authorized species and 
take numbers.
    (iii) Pinnipeds--see Table 2 (attached) for authorized species and 
take numbers.
    (iv) If any marine mammal species are encountered during seismic 
activities that are not listed in Table 2 (attached) 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) for seismic airgun 
operations or greater than or equal to 120 dB re 1 [mu]Pa (rms) for 
icebreaking activities, then the Holder of this Authorization 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 two Generator Injector (GI) airgun array (each with a 
discharge volume of 45 cubic inches [in\3\] or 105 in\3\) with a total 
volume of 90 in\3\ or 210 in\3\ (or smaller);
    (b) A multi-beam echosounder;
    (c) A single-beam echosounder;
    (d) An acoustic Doppler current profiler;
    (e) An acoustic locator;
    (f) A sub-bottom profiler; and
    (g) Icebreaking.
    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.
6. Mitigation and Monitoring Requirements
    The Holder of this Authorization is required to implement the 
following mitigation and monitoring requirements when conducting the 
specified activities to achieve the least practicable adverse impact on 
affected marine mammal species or stocks:
    (a) Utilize one, NMFS-qualified, vessel-based Protected Species 
Observer (PSO) 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. The Palmer's vessel crew shall also 
assist in detecting marine mammals, when practicable. PSOs shall have 
access to reticle binoculars (7 x 50 Fujinon). PSO shifts shall last no 
longer than 4 hours at a time. PSOs shall also make observations during 
daytime periods when the seismic airguns are not operating for 
comparison of animal abundance and behavior, when feasible.
    (b) PSOs shall conduct monitoring while the airgun array and 
streamer are being deployed or recovered from the water.
    (c) 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.
    (d) Visually observe the entire extent of the exclusion zone (180 
dB re 1 [mu]Pa [rms] for cetaceans and 190 dB re 1 [mu]Pa [rms] for 
pinnipeds; see Table 2 [above] for distances) using NMFS-qualified 
PSOs, for at least 30 minutes prior to starting the airgun array (day 
or night). If the PSO finds a marine mammal within the exclusion zone, 
NSF and ASC must delay the seismic survey until the marine mammal(s) 
has left the area. If the PSO sees a marine mammal that surfaces, then 
dives below the surface, the PSO shall wait 30 minutes. If the PSO sees 
no marine mammals during that time, they should assume that the animal 
has moved beyond the exclusion zone. 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 in the 
exclusion zone, the airguns may not be ramped-up. If one airgun is 
already running at a source level of at

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least 180 dB re 1 [mu]Pa (rms), NSF and ASC may start the second airgun 
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[f] below).
    (e) Establish a 180 dB re 1 [mu]Pa (rms) exclusion zone for 
cetaceans and a 190 dB re 1 [mu]Pa (rms) exclusion zone for pinnipeds 
before the two GI airgun array (90 or 210 in\3\ total volume) is in 
operation. See Table 2 (above) for distances and exclusion zones.
    (f) Implement a ``ramp-up'' procedure when starting up at the 
beginning of seismic operations or anytime after the entire array has 
been shut-down for more than 15 minutes, which means starting with a 
single GI airgun and adding a second GI airgun after five minutes. 
During ramp-up, the PSOs shall monitor the exclusion zone, and if 
marine mammals are sighted, a shut-down shall be implemented as though 
the full array (both GI airguns) were operational. Therefore, 
initiation of ramp-up procedures from shut-down requires that the PSOs 
be able to view the full exclusion zone as described in Condition 6(d) 
(above).
    (g) 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 shut-down, shall be taken.
    (h) Shut-down the airgun(s) if a marine mammal is detected within, 
approaches, or enters the relevant exclusion zone (as defined in Table 
2, above). A shut-down means all operating airguns are shut-down (i.e., 
turned off).
    (i) Following a shut-down, the airgun activity shall not resume 
until the PSO 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 and pinnipeds) or 30 minutes for species 
with longer dive durations (mysticetes and large odontocetes, including 
sperm, killer, and beaked whales).
    (j) Following a shut-down and subsequent animal departure, airgun 
operations may resume following ramp-up procedures described in 
Condition 6(f).
    (k) 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.
    (l) 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.
7. Reporting Requirements
    The Holder of this Authorization is required to:
    (a) Submit a draft report on all activities and monitoring results 
to the Office of Protected Resources, NMFS, within 90 days of the 
completion of the Palmer's Dumont d'Urville Sea off the coast of East 
Antarctica cruise. This report must contain and summarize the following 
information:
    (i) Dates, times, locations, heading, speed, weather, sea 
conditions (including Beaufort sea state and wind force), and 
associated activities during all seismic operations and marine mammal 
sightings;
    (ii) Species, number, location, distance from the vessel, and 
behavior of any marine mammals, as well as associated seismic activity 
(e.g., number of 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 120 
dB re 1 [mu]Pa (rms) (for icebreaking activities), greater than or 
equal to 160 dB re 1 [mu]Pa (rms) (for seismic airgun operations), 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 two GI airgun array) to the seismic activity at received 
levels greater than or equal to 120 dB re 1 [mu]Pa (rms) (for 
icebreaking activities), greater than or equal to 160 dB re 1 [mu]Pa 
(rms) (for seismic airgun operations), 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) (attached); 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.
    8. In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by this 
Authorization, such as an injury (Level A harassment), serious injury 
or mortality (e.g., ship-strike, gear interaction, and/or 
entanglement), NSF and ASC 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 [email protected] and 
[email protected]. 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).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS shall work with NSF and ASC 
to determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. NSF and ASC may not resume 
their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that NSF and ASC 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), 
NSF and ASC will immediately report the incident to the Chief of the 
Permits and Conservation Division, Office of Protected Resources,

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NMFS, at 301-427-8401, and/or by email to [email protected] and 
[email protected]. 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 NSF and 
ASC to determine whether modifications in the activities are 
appropriate.
    In the event that NSF and ASC 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), NSF and ASC 
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 [email protected] and [email protected], 
within 24 hours of the discovery. NSF and ASC 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.
    9. NSF and ASC is required to comply with the Terms and Conditions 
of the ITS corresponding to NMFS's Biological Opinion issued to both 
NSF, ASC, and NMFS's Office of Protected Resources (attached).
    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.

Information Solicited

    NMFS requests interested persons to submit comments and information 
concerning this proposed project and NMFS's preliminary determination 
of issuing an IHA (see ADDRESSES). 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: December 30, 2013.
P. Michael Payne,
Chief, Permits and Conservation Division, Office of Protected 
Resources, National Marine Fisheries Service.
[FR Doc. 2013-31471 Filed 12-31-13; 8:45 am]
BILLING CODE 3510-22-P