Incidental Takes of Marine Mammals During Specified Activities; Low-Energy Marine Seismic Survey in the Northwest Atlantic Ocean, August 2009, 41382-41397 [E9-19718]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 74, Number 157 (Monday, August 17, 2009)]
[Notices]
[Pages 41382-41397]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E9-19718]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XO99


Incidental Takes of Marine Mammals During Specified Activities; 
Low-Energy Marine Seismic Survey in the Northwest Atlantic Ocean, 
August 2009

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

ACTION:  Notice; issuance of an incidental take authorization.

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SUMMARY:  In accordance with the Marine Mammal Protection Act

[[Page 41383]]

(MMPA) regulations, notification is hereby given that NMFS has issued 
an Incidental Harassment Authorization (IHA) to Rice University (Rice), 
for the take of small numbers of marine mammals, by Level B harassment 
only, incidental to conducting a low-energy marine seismic survey in 
the Northwest Atlantic during August 2009.

DATES:  Effective August 12 through September 12, 2009.

ADDRESSES:  A copy of the IHA and the application are available by 
writing to P. Michael Payne, Chief, Permits, Conservation, and 
Education Division, Office of Protected Resources, National Marine 
Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910-3225 
or by telephoning the contact listed here.
    A copy of the application containing a list of the references used 
in this document may be obtained by writing to the address specified 
above, telephoning the contact listed below (see FOR FURTHER 
INFORMATION CONTACT), or visiting the Internet at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm. Documents cited in this 
notice may be viewed, by appointment, during regular business hours, at 
the aforementioned 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, 301-713-2289.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of marine mammals by United 
States citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if certain 
findings are made and either regulations are issued or, if the taking 
is limited to harassment, a notice of a proposed authorization is 
provided to the public for review.
    Authorization for incidental taking shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses, and if 
the permissible methods of taking and requirements pertaining to the 
mitigation, monitoring and reporting of such takings are set forth. 
NMFS has defined ``negligible impact'' in 50 CFR 216.103 as ''...an 
impact resulting from the specified activity that cannot be reasonably 
expected to, and is not reasonably likely to, adversely affect the 
species or stock through effects on annual rates of recruitment or 
survival.''
    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. 
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''].
    Section 101(a)(5)(D) establishes a 45-day time limit for NMFS= 
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 
comment period, NMFS must either issue or deny issuance of the 
authorization.

Summary of Request

    On April 21, 2009, NMFS received an application from Rice for the 
taking, by Level B harassment only, of small numbers of marine mammals 
incidental to conducting, under a cooperative agreement with the 
National Science Foundation (NSF), a low-energy marine seismic survey 
in the Northwest Atlantic Ocean. The funding for the survey is provided 
by the NSF. The survey will occur off New England within the U.S 
Exclusive Economic Zone (EEZ). Seismic operations will occur over the 
continental shelf southeast of the island of Martha's Vineyard, 
Massachusetts, and likely also in Nantucket Sound (see Figure 1 of 
Rice's application). The cruise is currently scheduled to occur from 
August 12 to 25, 2009. The survey will use two Generator Injector (GI) 
airguns with a discharge volume of 90 in\3\. Some minor deviation from 
these dates is possible, depending on logistics and weather.

Description of the Specified Activity

    Rice plans to conduct a low energy marine seismic survey and 
bathymetric program. The planned survey will involve one source vessel, 
the R/V Endeavor (Endeavor), which will occur in the Northwest Atlantic 
Ocean off of New England.
    The survey will examine stratigraphic controls on freshwater 
beneath the continental shelf off the U.S. east coast. In coastal 
settings worldwide, large freshwater volumes are sequestered in 
permeable continental shelf sediments. Freshwater storage and discharge 
have been documented off North and South America, Europe, and Asia. The 
proposed survey will investigate the Atlantic continental shelf off New 
England, where freshwater extends up to 100 km offshore. Using high-
resolution mathematical models and existing data, it is estimated that 
approximately 1,300 km\3\ (312 m1\3\) of freshwater is sequestered in 
the continental shelf from New York to Maine. However, the models 
indicate that the amount of sequestered freshwater is highly dependent 
on the thickness and distribution of aquifers and aquicludes. The 
survey will provide imaging of the subsurface and characterize the 
distribution of aquifers and aquicludes off Martha's Vineyard.
    The study will provide data integral to improved models to estimate 
the abundance of sequestered freshwater and will provide site survey 
data for an Integrated Ocean Drilling Program (IODP) proposal to drill 
these freshwater resources for hydrogeochemical, biological, and 
climate studies. Combined seismic and drilling data could help identify 
undeveloped freshwater resources that may represent a resource to urban 
coastal centers, if accurately characterized and managed. On a global 
scale, vast quantities of freshwater have been sequestered in the 
continental shelf and may represent an increasingly valuable resource 
to humans. This survey will help constrain process-based mathematical 
models for more precise estimations of the abundance and distribution 
of freshwater wells on the continental shelf.
    The source vessel, the Endeavor, will deploy two low-energy GI 
airguns as an energy source (with a discharge volume of 90 in\3\) and a 
600 m (1,969 ft) towed hydrophone streamer. The energy to the GI airgun 
is compressed air supplied by compressors onboard the source vessel. As 
the GI airgun is towed along the survey lines, the receiving systems 
will receive the returning acoustic signals.
    The planned seismic program will consist of approximately 1,757 km 
(1,092 mi) of surveys lines and turns (see Figure 1 of Rice's 
application). Most of the survey effort (approximately 1,638 km or 
1,018 mi) will take place in water <100 m deep, and approximately 119 
km (74 mi) will occur just past the

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shelf edge, in water depths >100 m (328 ft). There may be additional 
seismic operations associated with equipment testing, start-up, and 
repeat coverage of any areas where initial data quality is sub-
standard.
    All planned geophysical data acquisition activities will be 
conducted with assistance by scientists who have proposed the study, 
Dr. B. Dugan of Rice University, Dr. D. Lizarralde of Woods Hole 
Oceanographic Institution, and Dr. M. Person of New Mexico Institute of 
Mining and Technology. The vessel will be self-contained, and the crew 
will live aboard the vessel for the entire cruise.
    In addition to the seismic operations of the two GI airguns, a 
Knudsen 3260 echosounder, and EdgeTech sub-bottom profiler, and a 
``sparker'' system to image sub-bottom seafloor layers will be used at 
times during the survey.

Vessel Specifications

    The Endeavor has a length of 56.4 m (185 ft), a beam of 10.1 m 
(33.1 ft), and a maximum draft of 5.6 m (18.4 ft). The Endeavor has 
been operated by the University of Rhode Island's Graduate School of 
Oceanography for over thirty years to conduct oceanographic research 
throughout U.S. and world marine waters. The ship is powered by a 
single GM/EMD diesel engine, producing 3,050 hp, which drives a single 
propeller directly at a maximum of 900 revolutions per minute (rpm). 
The vessel also has a 320 hp bowthruster, which is not used during 
seismic acquisition. The optimal operation speed during seismic 
acquisition will be approximately 7.4 km/hour. When not towing seismic 
survey gear, the Endeavor can cruise at 18.5 km/hour. The Endeavor has 
a range of 14,816 km (9,206 mi). The Endeavor will also serve as the 
platform from which vessel-based Marine Mammal Visual Observers (MMVO) 
will watch for animals before and during GI airgun operations.

Acoustic Source Specifications

Seismic Airguns
    During the proposed survey, the Endeavor will tow two GI airguns, 
with a volume of 90 in\3\, and a 600 m long streamer containing 
hydrophones along predetermined lines. The two GI airguns will be towed 
approximately 25 m (82 ft) behind the Endeavor at a depth of 
approximately 3 m (10 ft). Seismic pulses will be emitted at intervals 
of approximately 5 seconds. At a speed of 7.4 km/hour, the 5 second 
spacing corresponds to a shot interval of approximately 10 m (33 ft). 
The operating pressure will be 2,000 psi. A single GI airgun will be 
used during turns.
    The generator chamber of each GI airgun, the one responsible for 
introducing the sound pulse into the ocean, has a volume of 45 in\3\. 
The larger (105 in\3\) injector chamber injects air into the 
previously-generated bubble to maintain its shape, and does not 
introduce more sound into the water. Both GI airguns will be fired 
simultaneously, for a total discharge volume of 90 in\3\. The GI 
airguns are relatively small compared to most other airgun arrays used 
for seismic arrays.
    A single GI airgun, a single 15 in\3\ watergun, or a sparker system 
may be used in shallow waters with sandy seafloors if the two GI 
airguns do not provide accurate seafloor imaging. The watergun is a 
marine seismic sound source that uses an implosive mechanism to provide 
an acoustic signal. Waterguns provide a richer source spectra in high 
frequencies (>200 Hz) than those of GI or airguns. The 15 in\3\ 
watergun potentially provides a cleaner signal for high-resolution 
studies in shallow water, with a short-pulse (<30 ms) providing 
resolution of approximately 10 m. The operating pressure will be 2,000 
psi. Peak pressure of the single watergun and sparker is estimated to 
be approximately 212 dB (0.4 bar-m) and 208 dB re 1 microPam (rms), 
respectively. Thus, both sources would have a considerably lower source 
level than the two GI airguns and single GI airgun.
    The root mean square (rms) received levels that are used as impact 
criteria for marine mammals are not directly comparable to the peak (pk 
or 0-pk) or peak-to-peak (pk - pk) values normally used to characterize 
source levels of airgun arrays. The measurement units used to describe 
airgun sources, peak or peak-to-peak decibels, are always higher than 
the ``root mean square'' (rms) decibels referred to in biological 
literature. A measured received level of 160 dB re 1 microPa (rms) in 
the far field would typically correspond to a peak measurement of 
approximately 170 to 172 dB, and to a peak-to-peak measurement of 
approximately 176 to 178 dB, as measured for the same pulse received at 
the same location (Greene, 1997; McCauley et al., 1998, 2000). The 
precise difference between rms and peak or peak-to-peak values depends 
on the frequency content and duration of the pulse, among other 
factors. However, the rms level is always lower than the peak or peak-
to-peak level for an airgun-type source.
    The sound pressure field of two 45 in\3\ GI airguns has not been 
modeled, but those for two 45 in\3\ Nucleus G airguns and one 45 in\3\ 
GI airgun have been modeled by Lamont-Doherty Earth Observatory (L-DEO) 
of Columbia University in relation to distance and direction from the 
airguns (see Figure 2 and 3 of Rice's application). The GI airgun is 
essentially two G airguns that are joined head to head. The G airgun 
signal has more energy than the GI airgun signal, but the peak energy 
levels are equivalent and appropriate for modeling purposes. The L-DEO 
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 GI airguns where sound levels of 190, 180, and 
160 dB re 1 microPa (rms) are predicted to be received in deep (>1,000 
m) water are shown in Table 1 of Rice's application. Because the model 
results are for G airguns, which have more energy than GI airguns of 
the same size, those distances are overestimates of the distances for 
the 45 in\3\ GI airguns.
Echosounder
    The Knudsen 3260 is a deep-water, dual-frequency echosounder with 
operating frequencies of 3.5 and 12 kHz. The high frequency (12 kHz) 
can be used to record water depth or to track pingers attached to 
various instruments deployed over the side. The low frequency (3.5 kHz) 
is used for sub-bottom profiling. Both frequencies will be used 
simultaneously during the present study. It will be used with a hull-
mounted, downward-facing transducer. A pulse up to 24 ms in length is 
emitted every several seconds with a nominal beam width of 80. Maximum 
output power at 3.5 kHz is 10 kW and at 12 kHz it is 2 kW. The maximum 
source output (downward) for the 3260 is estimated to be 211 dB re 1 
microPam at 10 kW.
Sub-bottom Profiler (SBP)
    The SBP is normally operated to provide information about 
sedimentary features and bottom topography; it will provide a 10 cm 
resolution of the sub-floor. During operations in deeper waters (>30-40 
m), an EdgeTech 3200-XS SBP will be operated from the ship with a SB-
512i towfish that will be towed at a depth of 5 m. It will transmit and 
record a 0.5-12 kHz swept pulse (or chirp), with a nominal beam width 
of 16-32. The SBP will produce a 30 ms pulse repeated at 0.5 to 1 s 
intervals. Depending on seafloor conditions, it could penetrate up to 
100 m.
Sparker
    The ``sparker'' system will be an alternative source of sub-floor 
imaging in shallower waters (<30 to 40 m or 98

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to 131 ft). Source level information from the manufacturer of a 
comparable system, the Applied Acoustics Engineering, Inc. SQUID 2000 
sparker system, gives a sound pressure level of 208 dB re 1 microPam 
(rms) at 1,500 Joules. The frequency output pulse for the SIG 2mille 
sparker system using the SIG sparker-electrode ELC820 is between 800 
and 850 Hz with pulse duration of approximately 1 ms. The trigger rate 
depends on the output power used; the rates go from 250 ms to 2.0 s. It 
is likely that the data collection for these projects will be 
accomplished using a 0.5 s or 1.0 s trigger rate with output power 
between 200 and 500 Joules. The Applied Acoustics CSP 700 sparker is a 
100 to 700 Joule system. The sound pressure level for this system is 
200 dB re 1 microPam (rms) at 500 Joules. The trigger rate depends on 
the output power used; the rates go from 250 ms to 1 s. It is likely 
that the data collection for these projects will be accomplished using 
a 0.5 s or 1 s trigger rate with output power between 200 and 500 
Joules. This will also use the SIG sparker-electrode model ELC820 that 
has an output frequency between 800 and 850 Hz with a pulse duration of 
approximately 1 ms.

Safety Radii

    NMFS has determined that for acoustic effects, using acoustic 
thresholds in combination with corresponding safety radii is the most 
effective way to consistently apply measures to avoid or minimize the 
impacts of an action, and to quantitatively estimate the effects of an 
action. Thresholds are used in two ways: (1) to establish a mitigation 
shut-down or power-down zone, i.e., if an animal enters an area 
calculated to be ensonified above the level of an established 
threshold, a sound source is powered down or shut down; and (2) to 
calculate take, in that a model may be used to calculate the area 
around the sound source that will be ensonified to that level or above, 
then, based on the estimated density of animals and the distance that 
the sound source moves, NMFS can estimate the number of marine mammals 
that may be ``taken.''
    As a matter of past practice and based on the best available 
information at the time regarding the effects of marine sound compiled 
over the past decade, NMFS has used conservative numerical estimates to 
approximate where Level A harassment from acoustic sources begins: 180 
re 1 microPa (rms) level for cetaceans and 190 dB re 1 microPa (rms) 
for pinnipeds. A review of the available scientific data using an 
application of science-based extrapolation procedures (Southall et al., 
2007) strongly suggests that Level A harassment (as well as TTS) from 
single exposure impulse events may occur at much higher levels than the 
levels previously estimated using very limited data. However, for 
purposes of this proposed action, Rice's application sets forth, and 
NMFS is using, the more conservative 180 and 190 dB re 1 microPa (rms) 
criteria. NMFS considers 160 re 1 microPa (rms) as the criterion for 
estimating the onset of Level B harassment from acoustic sources like 
impulse sounds used in the seismic survey.
    Emperical data concerning the 180 and 160 dB distances have been 
acquired based on measurements during the acoustic verification study 
conducted by L-DEO in the northern Gulf of Mexico from May 27 to June 
3, 2003 (Tolstoy et al., 2004a,b). Although the results are limited the 
data showed that radii around the airguns where the received level 
would be 180 dB re 1 microPa (rms), the safety criterion applicable to 
cetaceans (NMFS, 2000), vary with water depth. Similar depth-related 
variation is likely in the 190 dB distances applicable to pinnipeds. 
Correction factors were developed for water depths 100-1,000 m and <100 
m; the proposed survey will occur in depths approximately 20 to 125 m.
    The empirical data indicate that, for deep water (>1,000 m), the L-
DEO model tends to overestimate the received sound levels at a given 
distance (Tolstoy et al., 2004a,b). However, to be precautionary 
pending acquisition of additional empirical data, it is proposed that 
safety radii during GI airgun operations in deep water will be values 
predicted by L-DEO's model (see Table 1 below). Therefore, the assumed 
180 and 190 dB radii are 40 m (131 ft) and 10 m (33 ft) respectively.
    Empirical measurements were not conducted for intermediate depths 
(100-1,000 m). On the expectation that results will be intermediate 
between those from shallow and deep water, a 1.5x correction factor is 
applied to the estimates provided by the model for deep water 
situations. This is the same factor that was applied to the model 
estimates during L-DEO cruises in 2003. The assumed 180 and 190 dB 
radii in intermediate depth water are 60 m (197 ft) and 15 m (49 ft), 
respectively (see Table 1 below).
    Empirical measurements indicated that in shallow water (<100 m), 
the L-DEO model underestimates actual levels. In previous L-DEO 
projects, the exclusion zones were typically based on measured values 
and ranged from 1.3 to 15x higher than the modeled values depending on 
the size of the airgun array and the sound level measured (Tolstoy et 
al., 2004a,b). During the proposed cruise, similar factors will be 
applied to derive appropriate shallow water radii from the modeled deep 
water radii (see Table 1 below). The assumed 180 and 190 dB radii in 
shallow depth water are 296 m (971 ft) and 147 m (482 ft), respectively 
(see Table 1 below).

Table 1. Predicted distances to which sound levels [gteqt]190, 180, and 160 dB re 1 microPa might be received in
shallow (<100 m; 328 ft), intermediate (100-1,000 m; 328-3,280 ft), and deep (>1,000 m; 3,280 ft) water from the
  single 45 in\3\ GI airgun used during the seismic surveys in the northeastern Pacific Ocean during July 2009.
                             Distances are based on model results provided by L-DEO.
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                                                                                 Predicted RMS Distances (m)
          Source and Volume            Tow Depth (m)       Water Depth     -------------------------------------
                                                                             190 dB      180 dB        160 dB
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One GI airgun 45 in\3\                             3      Deep (>1,000 m)         8            23           220
                                                      ----------------------------------------------------------
                                                      ----------------------------------------------
                                                      ---------------------------------------------
                                                      ----------------------------------------------

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Table 1. Predicted distances to which sound levels [gteqt]190, 180, and 160 dB re 1 microPa might be received in
  shallow (<100 m; 328 ft), intermediate (100-1,000 m; 328-3,280 ft), and deep (>1,000 m; 3,280 ft) water from
  the two 45 in\3\ GI airguns used during the seismic surveys in the northwest Atlantic Ocean during August
  2009, and one 45 in\3\ GI airgun that will be used during turns. Distances are based on model results provided
  by L-DEO.

    The GI airguns, watergun, or sparker will be shut-down immediately 
when cetaceans are detected within or about to enter the 180 dB re 1 
microPa (rms) radius for the two GI airguns, or when pinnipeds are 
detected within or about to enter the 190 dB re 1 microPa (rms) radius 
for the two GI airguns. The 180 and 190 dB shut down criteria are 
consistent with guidelines listed for cetaceans and pinnipeds, 
respectively, by NMFS (2000) and other guidance by NMFS.

Dates, Duration, and Region of Activity

    The Endeavor is expected to depart from Narragansett, Rhode Island 
on approximately August 12, 2009, for an approximately four-hour 
transit to the study area southeast of Martha's Vineyard (see Figure 1 
of Rice's application). Seismic operations will commence upon arrival 
at the study area, with highest priority given to the central NNW-SSE 
line, followed by WSW-ENE lines, each of which cross the proposed IODP 
sites; lowest priority will be given to the survey lines in Nantucket 
Sound. The 14-day program will consist of approximately 11 days of 
seismic operations, and three contingency days in case of inclement 
weather. The Endeavor will return to Narragansett on approximately 
August 25, 2009. The exact dates of the proposed activities depend on 
logistics, weather conditions, and the need to repeat some lines if 
data quality is substandard.
    The proposed seismic survey will encompass the area 39.8[deg] to 
41.5[deg] N, 69.8[deg] to 70.6[deg] W (see Figure 1 of Rice's 
application). Water depths in the study area range from approximately 
20 to 125 m (66 to 410 ft), but are typically <100 m. The proposed 
survey will take place in Nantucket Sound and south of Nantucket and 
Martha's Vineyard. The ship will approach the south shore of Martha's 
Vineyard within 10 km (6.2 mi). The seismic survey will be conducted 
within the Exclusive Economic Zone (EEZ) of the U.S.A.

Comments and Responses

    A notice of receipt of the Rice application and proposed IHA was 
published in the Federal Register on June 18, 2009 (74 FR 28890). 
During the comment period, NMFS received comments from the Marine 
Mammal Commission (Commission). Following are comments from the 
Commission, and NMFS' responses.
    Comment 1: The Commission recommends that NMFS issue the requested 
authorization, provided that the authorization include all of the 
proposed monitoring and mitigation measures to minimize the likelihood 
of serious injury to the potentially affected marine mammal species.
    Response: NMFS concurs with the Commission's recommendation and has 
included requirements to these effects in the IHA issued to Rice.
    Comment 2: The Commission recommends that NMFS issue the requested 
authorization, provided that NMFS (1) clarify when the use of night 
vision devices (NVD) will be required and provide additional 
justification for its implied conclusion that observers will be able to 
achieve a high nighttime detection rate, and (2) require the use of 
passive acoustic monitoring (PAM) during all operations.
    Response: (1) Though it depends on the lights on the ship, the sea 
state, and thermal factors, MMVOs estimated that visual detection is 
effective out to between 150 and 250 m using NVDs and about 30 m with 
the naked eye (dolphins, porpoises, pinnipeds, and large whales are the 
species likely to be detected in the shallow and intermediate water 
depths, where the safety zones are the largest). Marine seismic surveys 
may continue into night and low-light hours if such segment(s) of the 
survey are initiated when the entire relevant safety zones are visible 
and can be effectively monitored. 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 safety zone cannot be effectively monitored by the MMVOs on 
duty. NMFS has included a requirement to this effect in the IHA issued 
to Rice; and
    (2) PAM remains as optional, but willingly used as supplemental 
effort specific to the R/V Marcus G. Langseth. The use of PAM in any 
situation as a ``required'' mitigation measure is addressed as 
premature in NSF's draft Programmatic Environmental Impact Statement. 
NMFS recommends that applicants seeking an Incidental Take 
Authorization use PAM for monitoring and mitigation purposes whenever 
possible.
    Comment 3: The Commission recommends that NMFS issue the requested 
authorization, provided that the authorization require that the 
monitoring period be extended to at least one hour before seismic 
activities are initiated or to at least one hour before airgun 
activities are resumed after a power-down because of a marine mammal 
sighting within the safety zone.
    Response: As the Commission points out, several species of 
cetaceans that occur in the study area are capable of remaining 
underwater for more than 30 minutes. However, for the following 
reasons, NMFS believes that 30 minutes is an adequate length for the 
monitoring period prior to the start-up of airguns: (1) because the 
Endeavor is required to ramp-up; (2) in many cases MMOs are making 
observations during times when the sound sources are not being operated 
and will actually be observing the area prior to the start-up 
observation period anyway; (3) many of the species that may be exposed 
do not stay underwater more than 30 min; and (4) all else being equal 
and if a deep-diving individual happened to be in the area in

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the short time immediately prior to the pre-start-up monitoring, if an 
animal's maximum underwater time is 45 min, there is only a one in 
three chance that its last random surfacing would be prior to the 
beginning of the required monitoring period.
    Also, seismic vessels are moving continuously (because of the towed 
array and airguns) and NMFS believes that unless the animals submerges 
and follows at the speed of the vessel (highly unlikely, especially 
when considering that a significant part of their movements is vertical 
[deep-diving]), the vessel will be far beyond the length of the safety 
radii within 30 min, and therefore it will be safe to start the airguns 
again.
    Comment 4: The Commission recommends that NMFS issue the requested 
authorization, provided that the applicant carry out observations of 
all instances where ramp-up is employed to gather data on its 
effectiveness as a mitigation measure.
    Response: The IHA requires that MMVOs on the Endeavor make 
observations prior to ramp-up, during all ramp-ups, and during all 
daytime seismic operations and record the following information when a 
marine mammals 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 reactions 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 operations and whether in state of ramp-up 
or power-down), sea state, visibility, cloud cover, and sun glare.
    These requirements should provide information regarding the 
effectiveness of ramp-up as a mitigation measure, provided animals are 
detecting during ramp-up. NMFS has included a requirement to this 
effect in the IHA issued to Rice.
    Comment 5: The Commission recommends that NMFS issue the requested 
authorization, provided that the authorization require that operations 
be suspended immediately, pending review by NMFS, if a dead or 
seriously injured marine mammal is found in the vicinity of the 
operations and the death or injury could have occurred incidental to 
the seismic survey.
    Response: NMFS has included a requirement to this effect in the IHA 
issued to Rice.

Description of Marine Mammals in the Proposed Activity Area

    A total of 34 marine mammal species (30 cetacean and 4 pinniped) 
are known to or may occur in the proposed study area (see Table 2, 
Waring et al., 2007). Several species are listed as Endangered under 
the Endangered Species Act (ESA): the North Atlantic right, humpback, 
sei, fin, blue, and sperm whales. The Western North Atlantic Coastal 
Morphotype Stock of common bottlenose dolphins is listed as Depleted 
under the MMPA.
    Table 2 below outlines the marine mammal species, their habitat, 
abundance, density, and conservation status in the proposed project 
area. Additional information regarding the distribution of these 
species expected to be found in the project area and how the estimated 
densities were calculated may be found in the notice of the proposed 
IHA (74 FR 28890, June 18, 2009) and may be found in Rice's 
application.
BILLING CODE 3510-22-22-S

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[GRAPHIC] [TIFF OMITTED] TN17AU09.016

BILLING CODE 3510-22-C
    Several Federal Marine Protected Areas (MPAs) or sanctuaries have 
been established near the proposed study area, primarily with the 
intention of preserving cetacean habitat (see Table 3 of Rice's 
application; Hoyt, 2005; Cetacean Habitat, 2009; see also Figure 1 of 
Rice's application). Cape Cod Bay is designated as Right Whale Critical 
Habitat, as is the Great South Channel Northern Right Whale Critical 
Habitat Area located to the east of Cape Cod. The Gerry E. Studds 
Stellwagen Bank National Marine Sanctuary is located north of the 
proposed study are in the Gulf of Maine. The proposed survey is not 
located within any Federal MPAs or sanctuaries. However, a sanctuary 
designated by the state of Massachusetts occurs within the study area - 
the Cape and Islands Ocean Sanctuary. This sanctuary includes nearshore 
waters of southern Cape Cod, Martha's Vineyard, and Nantucket (see 
Table 3 of Rice's application). In addition, there are four National 
Wildlife Refuges within the study area (Monomoy, Nantucket, Mashpee, 
and Nomans Island) and a National Estuarine Research Reserve (Waquoit 
Bay). Except for Nomans Island, these refuges and reserves are located 
in Nantucket Sound. Three Canadian protected areas also occur in the 
Northwest Atlantic for cetacean habitat protection, including the Bay 
of Fundy and Roseway Basin Right Whale Conservation Areas (see Figure 1 
of Rice's application), as well as the Gully Marine Protected Area off 
the Scotian Shelf.

[[Page 41391]]

    There are several areas that are closed to commercial fishing on a 
seasonal basis to reduce the risk of entanglement or incidental 
mortality to marine mammals. To protect large whales like right, 
humpback, and fin whales, NMFS implemented seasonal area management 
zones for lobster, several groundfish, and other marine invertebrate 
trap/pot fisheries, prohibiting gear in the Great South Channel 
Critical Habitat Area from April through June; additional dynamic area 
management zones could be imposed for 15 day time periods if credible 
fisheries observers identify concentrations of right whales in areas 
north of 40 N (NMFS 1999, 2008). To reduce fishery impacts on harbor 
porpoises, additional time and area closures in the Gulf of Maine 
include fall and winter along the mid-coastal area, winter and spring 
in Massachusetts Bay and southern Cape Cod, winter and spring in 
offshore areas, and February around Cashes Ledge (NMFS, 1998). 
Fishermen are also required to use pingers, and New Jersey and mid-
Atlantic waters could close seasonally for fishermen failing to apply 
specific gear modifications (NMFS, 1998).

Potential Effects on Marine Mammals

Potential Effects of Airguns

    The effects of sounds from airguns might result in one or more of 
the following: tolerance, masking of natural sounds, behavioral 
disturbances, temporary or permanent hearing impairment, and 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 project would result in any 
cases of permanent hearing impairment, or any significant non-auditory 
physical or physiological effects. Some behavioral disturbance is 
expected, but this would be localized and short-term.
    The notice of the proposed IHA (74 FR 28890, June 18, 2009) 
included a discussion of the effects of sounds from airguns on 
mysticetes, odontocetes, and pinnipeds, including tolerance, masking, 
behavioral disturbance, hearing impairment, and other non-auditory 
physical effects. Additional information on the behavioral reactions 
(or lack thereof) by all types of marine mammals to seismic vessels can 
be found in Rice's application and associated EA.
    The notice of the proposed IHA also included a discussion of the 
potential effects of the echosounder and sub-bottom profiler. Because 
of the shape of the beams of these sources and their power, NMFS 
believes it unlikely that marine mammals will be exposed to either the 
echosounder or sub-bottom profiler at levels at or above those likely 
to cause harassment. Further, NMFS believes that the brief exposure of 
cetaceans to a few signals from the echosounder or sub-bottom profiler 
sonar systems is not likely to result in the harassment of marine 
mammals.

Estimated Take by Incidental Harassment

    The notice of the proposed IHA (74 FR 28890, June 18, 2009) 
included an in-depth discussion of the methods used to calculate the 
densities of the marine mammals in the area of the seismic survey and 
the take estimates. Additional information was included in Rice's 
application. A summary is included here.
    All anticipated takes would be ``takes by harassment,'' involving 
temporary changes in behavior. The monitoring and mitigation measures 
are expected to minimize the possibility of injurious takes. (However, 
as noted earlier and in Appendix A of Rice's application, there is no 
specific information demonstrating that injurious ``takes'' would occur 
even in the absence of the planned monitoring and mitigation measures.) 
The sections below describe methods to estimate ``take by harassment'', 
and present estimates of the numbers of marine mammals that might be 
affected during the proposed seismic program in the Northwest Atlantic 
Ocean. The estimates of ``take by harassment'' are based on (1) 
cetacean densities (numbers per unit area) obtained during aerial 
surveys off New England during 2002 and 2004 by NMFS Northeast 
Fisheries Science Center (NEFSC), and (2) estimates of the size of the 
area where effects could potentially occur. Few, if any, pinnipeds are 
expected to be encountered during the proposed survey in the summer.
    The following estimates are based on a consideration of the number 
of marine mammals that might be disturbed appreciably by operations 
with the GI airgun to be used during approximately 1,757 line km (1,092 
mi) of surveys (including turns) off the New England coast. The 
anticipated radii of influence of the other sound sources (i.e., SBP, 
sparker system, and echosounder) are less than those for the GI 
airguns. It is assumed that, during simultaneous operations of the GI 
airguns and other sound sources, any marine mammals close enough to be 
affected by the other sound sources would already be affected by the GI 
airguns. However, whether or not the GI airguns are operating 
simultaneously with the other sound sources, marine mammals are 
expected to exhibit no more than short-term and inconsequential 
responses to the other sound sources given their characteristics (e.g., 
narrow downward-directed beam in the echosounder). Therefore, no 
additional allowance is included for animals that could be affected by 
the other sound sources.
    Extensive systematic aircraft and ship-based surveys have been 
conducted for marine mammals offshore from New England (e.g., see 
Palka, 2006). Those that were conducted in the proposed seismic survey 
area were used for density estimates. Oceanographic conditions 
influence the distribution and numbers of marine mammals present in the 
study area, resulting in year-to-year variation in the distribution and 
abundance of many marine mammal species. Thus, for some species the 
densities derived from these surveys may not be representative of the 
densities that will be encountered during the proposed seismic survey. 
To provide some allowance for these uncertainties, ``maximum 
estimates'' as well as ``best estimates'' of the numbers potentially 
affected have been derived. Best and maximum estimates are based on the 
average and maximum estimates of densities calculated from the 
appropriate densities reported by Palka (2006).
    Table 4 of Rice's application gives the average and maximum 
densities for each species of cetacean reported in the proposed survey 
area off New England, corrected for effort, based on the densities as 
described above. The densities from those studies had been corrected, 
by the original authors, for both detectability bias and availability 
bias. Detectability bias associated with diminishing sightability with 
increasing lateral distance from the tracklines [f(0)]. Availability 
bias refers to the fact that there is less-than-100-percent probability 
of sighting an animal that is present along the survey trackline, and 
it is measured by g(0).
    It should be noted that the following estimates of ``takes by 
harassment'' assume that the surveys will be undertaken and completed. 
As is typical on offshore ship surveys, inclement weather, and 
equipment malfunctions are likely to cause delays and may limit the 
number of useful line kms of seismic operations that can be undertaken. 
Furthermore, any marine mammal

[[Page 41392]]

sightings within or near the designated safety zones will result in the 
shut-down of seismic operations as a mitigation measure. Thus, the 
following estimates of the numbers of marine mammals potentially 
exposed to 160 dB sounds are precautionary, and probably overestimate 
the actual numbers of marine mammals that might be involved. These 
estimates assume that there will be no weather, equipment, or 
mitigation delays, which is highly likely.
    There is some uncertainty about the representativeness of the data 
and the assumptions used in the calculations. However, the approach 
used is believed to be the best available approach. Also, to provide 
some allowance for these uncertainties ``maximum estimates'' as well as 
``best estimates'' of the numbers potentially affected have been 
derived. The estimated number of potential individuals exposed are 
presented below based on the 160 dB re 1 microPa (rms) criterion for 
all cetaceans and pinnipeds. It is assumed that a marine mammal exposed 
to airgun at that received level might change their behavior 
sufficiently to be considered ``taken by harassment.''
    The number of different individuals that may be exposed to GI 
airgun sounds with received levels [gteqt]160 dB re 1 microPa (rms) on 
one or more occasions was estimated by considering the total marine 
area that would be within the 160-dB radius around the operating airgun 
array on at least one occasion. The seismic lines do not run parallel 
to each other in close proximity, which minimizes the number of times 
an individual mammal may be exposed during the survey. Table 5 of 
Rice's application shows the best and maximum estimates of the number 
of marine mammals that could potentially be affected during the seismic 
survey.
    The number of different individuals potentially exposed to received 
levels [gteqt]160 dB re 1 microPa (rms) was calculated by multiplying:
     The expected species density, either ``mean'' (i.e., best 
estimate) or ``maximum,'' times;
     The anticipated area to be ensonified to that level during 
GI airgun operations.
    The area expected to be ensonified was determined by entering the 
planned survey lines into a MapInfo Geographic Information System 
(GIS), using the GIS to identify the relevant areas by ``drawing'' the 
applicable 160 dB buffer around each seismic line (two GI airgun 
buffer) and turns (one GI airgun buffer) (depending on water and tow 
depth) and then calculating the total area within the buffers. Areas 
where overlap occurred (because of intersecting lines) were included 
only once to determine the area expected to be ensonified.
    Applying the approach described above, approximately 2,877 km\2\ 
(1,111 mi\2\) would be within the 160 dB isopleth on one or more 
occasions during the survey. This approach does not allow for 
``turnover'' in the mammal populations in the study area during the 
course of the studies. That might underestimate actual numbers of 
individuals exposed, although the conservative distances used to 
calculate the area may offset this. In addition, the approach assumes 
that no cetaceans will move away or toward the trackline as the 
Endeavor approaches in response to increasing sound levels prior to the 
time the levels reach 160 dB. Another way of interpreting the estimates 
that follow is that they represent the number of individuals that are 
expected (in the absence of a seismic survey) to occur in the waters 
that will be exposed to micro160 dB re 1 microPa (rms).
    Table 3 (see below) outlines the species, estimated stock 
population (minimum and best), and estimated percentage of the stock 
exposed to seismic pulses in the project area. Additional information 
regarding status, abundance, and distribution of the marine mammals in 
the area and how densities were calculated was included in Table 2 (see 
above), the notice of the proposed IHA (74 FR 28890) and may be found 
in Rice's application.

 Table 3. The estimates of the possible numbers of marine mammals exposed to sound levels greater than or equal
 to 160 dB during Rice's proposed seismic survey off the coast of New England in August 2009. The proposed sound
    source is a single GI airgun. Received levels are expressed in dB re 1 microPa (rms) (averaged over pulse
  duration), consistent with NMFS' practice. Not all marine mammals will change their behavior when exposed to
these sound levels, but some may alter their behavior when levels are lower (see text). See Tables 3-5 in Rice's
                                         application for further detail.
----------------------------------------------------------------------------------------------------------------
                                     of Individuals   of Individuals     Approx. % Regional
              Species                   Exposed (best)\1\         Exposed (max)\1\        Population (best)\2\
----------------------------------------------------------------------------------------------------------------
Mysticetes
-----------------------------------
Nort Atlantic right whale\3\                              0                         0                         0
(Eubalena glacialis)
----------------------------------------------------------------------------------------------------------------
Humpback whale                                            2                        57                      0.02
(Megaptera novaeangliae)
----------------------------------------------------------------------------------------------------------------
Minke whale(Balaenoptera                                  0                        21                     <0.01
 acutorostrata)
----------------------------------------------------------------------------------------------------------------
Bryde's whale                                             0                         0                         0
(Balenoptera brydei)
----------------------------------------------------------------------------------------------------------------
Sei whale(Balaenoptera borealis)                          0                         0                         0
----------------------------------------------------------------------------------------------------------------
Fin whale                                                11                        75                      0.02
(Balaenoptera physalus)
----------------------------------------------------------------------------------------------------------------
Blue whale                                                0                         0                         0
(Balaenoptera musculus)
----------------------------------------------------------------------------------------------------------------
Odontocetes
-----------------------------------

[[Page 41393]]

 
Sperm whale                                               2                        77                      0.02
(Physeter macrocephalus)
----------------------------------------------------------------------------------------------------------------
Pygmy sperm whale                                         0                         0                         0
(Kogia breviceps)
----------------------------------------------------------------------------------------------------------------
Dwarf sperm whale                                         0                         0                         0
(Kogia sima)
----------------------------------------------------------------------------------------------------------------
Cuvier's beaked whale                                     0                         0                         0
(Ziphius cavirostris)
----------------------------------------------------------------------------------------------------------------
Northern bottlenose whale                                 0                         1                         0
(Hyperodon ampullatus)
----------------------------------------------------------------------------------------------------------------
True's beaked whale(Mesoplodon                            0                         0                         0
 mirus)
----------------------------------------------------------------------------------------------------------------
Gervais' beaked whale                                     0                         0                         0
(Mesoplodon europaeus)
----------------------------------------------------------------------------------------------------------------
Sowerby's beaked whale                                    0                         1                         0
(Mesoplodon bidens)
----------------------------------------------------------------------------------------------------------------
Blainville's beaked whale                                 0                         0                         0
(Mesoplodon densirostris)
----------------------------------------------------------------------------------------------------------------
Unidentified beaked whale                                 0                         2                      N.A.
----------------------------------------------------------------------------------------------------------------
Bottlenose dolphin\3\                                    39                     4,700                      0.05
(Tursiops truncatus)
----------------------------------------------------------------------------------------------------------------
Pantropical spotted dolphin                               0                         0                         0
((Stenella attenuata))
----------------------------------------------------------------------------------------------------------------
Atlantic spotted dolphin                                  0                         0                         0
((Stenella frontalis))
----------------------------------------------------------------------------------------------------------------
Spinner dolphins                                          0                         0                         0
((Stenella longirostris))
----------------------------------------------------------------------------------------------------------------
Striped dolphin                                           0                       212                     <0.01
(Stenella coeruleoalba)
----------------------------------------------------------------------------------------------------------------
Common dolphin                                          349                     3,189                     <0.17
(Delphinu) sp.
----------------------------------------------------------------------------------------------------------------
White-beaked dolphin                                      0                         0                         0
((Lagenorhynchus albirostris))
----------------------------------------------------------------------------------------------------------------
Atlantic white-sided dolphin\5\                           0                         0                         0
Lagenorhynchus acutus)
----------------------------------------------------------------------------------------------------------------
Risso's dolphin                                           2                       929                      0.01
(Grampus griseus)
----------------------------------------------------------------------------------------------------------------
False killer whale                                        0                         0                         0
(Pseudorca crassidens)
----------------------------------------------------------------------------------------------------------------
Killer whale                                              0                         0                         0
(Orcinus orca)
----------------------------------------------------------------------------------------------------------------
Long-finned pilot whale                                N.A.                      N.A.                     <0.01
((Globlicephala melas))
----------------------------------------------------------------------------------------------------------------

[[Page 41394]]

 
Short-finned pilot whale                               N.A.                      N.A.                     <0.01
(Globicephala macrorhynchus)
----------------------------------------------------------------------------------------------------------------
Unidentified pilot whale                                 10                     1,101                     <0.01
Globcephala sp.)
----------------------------------------------------------------------------------------------------------------
Harbor porpoise                                           0                         0                         0
(Phocoena phocoena)
----------------------------------------------------------------------------------------------------------------
Pinnipeds
-----------------------------------
Harbor seal\4\                                           10                      N.A.                      0.01
(Phoca vitulina)
----------------------------------------------------------------------------------------------------------------
Gray seal                                                 5                      N.A.                     <0.01
(Halichoerus grypus)
----------------------------------------------------------------------------------------------------------------
Harp seal\4\                                              0                         0                         0
(Pagophilius groenlandicus)
----------------------------------------------------------------------------------------------------------------
Hooded seal                                               0                         0                         0
(Cystophora cristata)
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
N.A. - Data not available or species status was not assessed
\1\ Best estimate and maximum estimates of exposure are from Table 5 of Rice's application.
\2\ Regional population size estimates are from Table 2 (above) and Table 2 of Rice's application.
\3\Species not sighted in the surveys used for density estimates, but that could occur in low densities in the
  proposed survey area.
\4\Species for which summer densities in the study area are unavailable, but could occur there in low numbers.
\5\Not identified to species level.

    Table 5 of Rice's application shows the best and maximum estimates 
of the number of exposures and the number of individual marine mammals 
that potentially could be exposed to greater than or equal to 160 dB re 
1 microPa (rms) during the different legs of the seismic survey if no 
animals moved away from the survey vessel.
    The ``best estimate'' of the number of individual marine mammals 
that could be exposed to seismic sounds with received levels greater 
than or equal to 160 dB re 1 microPa (rms) (but below Level A 
harassment thresholds) during the survey is shown in Table 5 of Rice's 
application and Table 3 (shown above). That includes 0 North Atlantic 
right (0 percent of the regional population), 2 humpback (0.02 percent 
of the regional population), 11 fin (0.03 percent of the regional 
population), and 2 sperm whales (0.02 percent of the regional 
population), and no beaked whales. Based on the best estimates, most 
(93 percent) of the marine mammals potentially exposed are dolphins. 
The common dolphin and bottlenose dolphin are estimated to be the most 
common species exposed to 160 dB re microPa (rms); the best take 
estimates for those species are 349 (0.17 percent of the regional 
population) and 39 (0.05 percent of the regional population), 
respectively. Estimates for the other dolphin species that could be 
exposed are lower (see Table 5 of Rice's application). The authorized 
takes for unidentified pilot whales and Risso's dolphins was increased 
to 50 (<0.01 percent of the regional population) and 30 (0.15 percent 
of the regional population), respectively, to account for the average 
group size these species in which they are often encountered. In 
addition, it is estimated that 10 harbor seals (0.01 percent) and 5 
gray seals (<0.01 percent) may be exposed to sound levels greater than 
or 160 dB re 1 microPa (rms).
    The ``maximum estimate'' column of Table 5 of Rice's application 
shows an estimated total of 9,479 cetaceans exposed to seismic sounds 
micro160 dB during the surveys. Those estimates are based on the 
highest calculated density in any survey stratum; in this case, the 
stratum with the highest density invariably was one of the areas where 
very little of the proposed seismic survey will take place, i.e., 
Georges Central or Shelf Central. In other words, densities observed in 
the 2002 and 2004 aerial surveys were lowest in the Georges West 
operation area, where most of the proposed seismic surveys will take 
place. Therefore, the numbers for which ``take authorization'' is 
requested, given in the far right column of Table 5 of Rice's 
application, are the best estimates. For three endangered species, the 
best estimates were set at the species' mean group size. The North 
Atlantic right whale, which was not sighted during the aerial surveys, 
could occur in the survey area, and is usually seen individually 
(feeding aggregations are not expected to occur in the study area). The 
humpback and sperm whales, each of whose calculated best estimate was 
one, have a mean group size of two.

Potential Effects on Marine Mammal Habitat

    A detailed discussion of the potential effects of this action on 
marine mammal habitat, including physiological and behavioral effects 
on marine fish and invertebrates was included in the proposed IHA (74 
FR 28890, June 18, 2009). Based on the discussion in the

[[Page 41395]]

proposed IHA notice and the nature of the activities (limited 
duration), the authorized operations are not expected to have any 
habitat-related effects that could cause significant or long-term 
consequences for individual marine mammals or their populations or 
stocks. Similarly, any effects to food resources are expected to be 
negligible.
    The Rice seismic survey will not result in any permanent impact on 
habitats used by marine mammals, or to the food sources they use. The 
main impact issue associated with the proposed activity will be 
temporarily elevated noise levels and the associated direct effects on 
marine mammals, as described above. The following sections briefly 
review effects of airguns on fish and invertebrates, and more details 
are included in Rice's application and associated EA.

Subsistence Activities

    There is no subsistence hunting for marine mammals in the waters 
off of the coast of New England that implicates MMPA Section 
101(a)(5)(D).

Mitigation and Monitoring

    Mitigation and monitoring measures for the seismic survey have been 
developed and refined during previous NSF-funded seismic studies and 
associated Environmental Assessments (EAs), IHA applications, and IHAs. 
The mitigation and monitoring measures described herein represent a 
combination of procedures required by past IHAs for other similar 
projects and on recommended best practices in Richardson et al. (1995), 
Pierson et al. (1998), and Weir and Dolman (2007). The measures are 
described in detail below.
    Mitigation measures proposed for the survey include:
    (1) Speed or course alteration, provided that doing so will not 
compromise operational safety requirements;
    (2) GI airgun shut-down procedures;
    (3) GI airgun power-downs procedures (including turns);
    (4) GI airgun ramp-up procedures;
    (5) Procedures for species of particular concern, e.g., emergency 
shut-down procedures if a North Atlantic right whale is sighted at any 
distance, and concentrations of humpback, fin, sperm, blue, and/or sei 
whales will be avoided.
    The thresholds for estimating take are also used in connection with 
proposed mitigation. The radii in Table 2 (above) will be used as shut-
down criteria for the other sound sources (single GI airgun, watergun, 
and sparker), all of which have lower source levels than the two GI 
airguns.

Vessel-based Visual Monitoring

    Marine Mammal Visual Observers (MMVOs) will be based aboard the 
seismic source vessel and will watch for marine mammals near the vessel 
during daytime GI airgun operations and during start-ups of airguns at 
night. MMVOs 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 of the airguns. When feasible MMVOs will 
also make observations during daytime periods when the seismic system 
is not operating for comparison of sighting rates and animal behavior 
with vs. without GI airgun operations. Based on MMVO observations, the 
GI airgun will be shut-down (see below) when marine mammals are 
detected within or about to enter a designated EZ. The EZ is an area in 
which a possibility exists of adverse effects on animal hearing or 
other physical effects (see Table 1 above for the isopleths as they 
correspond to the relevant EZs). The MMVOs will continue to maintain 
watch to determine when the animal(s) are outside the safety radius, 
and airgun operations will not resume until the animal has left that 
zone. The predicted distances for the safety radius are listed 
according to the sound source, water depth, and received isopleths in 
Table 1.
    MMVOs will be appointed by the academic institution conducting the 
research cruise, with NMFS Office of Protected Resources concurrence. 
During seismic operations off the coast of New England, a total of 
three MMVOs are planned to be aboard the Endeavor. Two MMVOs (except 
during meal times, when at least one MMVO will be on watch) will 
monitor the EZ during daytime GI airgun operations and any night-time 
startups of the airguns. MMVOs will normally work in daytime shifts of 
four hour duration or less. The vessel crew will also be instructed to 
assist in detecting marine mammals and implementing mitigation measures 
(if practical). Before the start of the seismic survey the crew will be 
given additional instruction regarding how to do so.
    The Endeavor is a suitable platform from which MMVOs will conduct 
marine mammal observations. Two locations are likely as observation 
stations onboard the Endeavor; observations may take place from the 
flying bridge approximately 11 m (36 ft) above sea level or the bridge 
(8.2 m or 27 ft).
    During the daytime, the MMVO(s) will scan the area around the 
vessel systematically with standard equipment such as reticle 
binoculars (e.g., 7x50), optical range finders, and with the naked eye. 
During darkness, night vision devices (NVDs) will be available, when 
required. Vessel lights and/or NVDs are useful in sightings some marine 
mammals at the surface within a short distance from the ship (within 
the EZ for the two GI airguns). The MMVOs will be in wireless 
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 GI airgun shut-down.
    Speed or Course Alteration - If a marine mammal is detected outside 
the EZ, but is likely to enter based on its position an