Incidental Takes of Marine Mammals During Specified Activities; Low-Energy Marine Seismic Survey in the Northeast Pacific Ocean, July 2009, 34715-34725 [E9-17067]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 74, Number 136 (Friday, July 17, 2009)]
[Notices]
[Pages 34715-34725]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E9-17067]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XO71


Incidental Takes of Marine Mammals During Specified Activities; 
Low-Energy Marine Seismic Survey in the Northeast Pacific Ocean, July 
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 (MMPA) 
regulations, notification is hereby given that NMFS has issued an 
Incidental Harassment Authorization (IHA) to Scripps Institution of 
Oceanography (SIO), a part of the University of California San Diego 
(UCSD), for the take of small numbers of marine mammals, by Level B 
harassment only, incidental to conducting a marine seismic survey in 
the Northeast Pacific Ocean during July 2009.

DATES: Effective July 14, 2009, through August 14, 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#applications. 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 Ken Hollingshead, 
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''].

16 U.S.C. 1362(18).
    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 March 9, 2009, NMFS received an application from SIO for the 
taking, by Level B harassment only, of small numbers of marine mammals 
incidental to conducting, under cooperative agreement with the National 
Science Foundation (NSF), a low-energy marine seismic survey in the 
Northeast Pacific Ocean. The funding for the survey is provided by the 
NSF. The proposed survey will occur in an overall area between 
approximately 44[deg] and 45[deg] N. and 124.5[deg] and 126[deg] W. 
within the Exclusive Economic Zone (EEZ) of the U.S.A., and is 
scheduled to occur from July 14-20, 2009. The survey will use a single 
Generator Injector (GI) airgun with a discharge volume of 45 in\3\. 
Some minor deviation from these dates is possible, depending on 
logistics and weather.
    The survey is virtually identical to one conducted by SIO in 2007 
under an IHA issued in September 2007 (NMFS, 2007). The SIO 2009 IHA 
application contains minor updates to the project description, updated 
marine mammal population sizes based on the most recent NMFS annual 
stock assessment, an assessment of the relevance of the marine mammal 
density and distribution data contained in the SIO 2007 IHA application 
based on cruise reports from the NMFS SWFSC ORCAWHALE 2008 cruise, and 
updated information on effects of airguns on marine mammals (see 
Appendix A of SIO's application).

Description of the Specified Activity

    SIO plans to conduct an ocean bottom seismograph (OBS) deployment 
and a magnetic, bathymetric, and seismic survey. The planned survey 
will involve one source vessel, the R/V Wecoma (Wecoma), and will occur 
in the Northeast Pacific Ocean off the coast of Oregon.
    The purpose of the research program is to record micro-earthquakes 
in the

[[Page 34716]]

forearc to determine whether seismicity on the plate boundary is 
characteristic of a locked or a freely slipping fault plane. Several 
earthquakes large enough to be recorded on land-based seismic nets have 
occurred along this segment in the past several years. The occurrence 
of ``repeating earthquakes'' (earthquakes with identical waveforms 
indicating repeated rupture of almost the same fault patch) suggests 
that this region is at a boundary between a freely slipping and a 
locked portion of the fault. Some models suggest that the forearc basin 
north of the seismically active zone may be locked; others suggest that 
portion of the fault is slipping freely. OBSs have been deployed for a 
year, and a seismic survey will be used to characterize the shallow 
sediment structure around the instruments. Also, included in the 
research is the use of a magnetometer and sub-bottom profiler.
    The source vessel, the Wecoma, will deploy a single low-energy GI 
airgun as an energy source (with a discharge volume of 45 in\3\) and a 
300 m (984 ft), 16 channel, towed hydrophone streamer. Sixteen OBSs 
were deployed in July and September, 2008. They will continue to 
acquire data during this cruise, and will be recovered before returning 
to port. 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 seismic program will consist of approximately 21 km (13 mi) of 
surveys over each of the 16 OBSs (see Figure 1 of SIO's application). 
Water depths at the seismic survey locations rang from just less than 
100 m (328 ft) to almost 3,000 m (9,842 ft) (see Figure 1 of SIO's 
application). The GI airgun will be operated on a small grid for 
approximately two hours at each of the 16 OBS sites. There will be 
additional seismic operations associated with equipment testing, start-
ups, and repeat coverage of any areas where initial data quality is 
substandard.
    All planned geophysical data acquisition activities will be 
conducted by SIO with on-board assistance by the scientists who have 
proposed the study. The Chief Scientist is Dr. Anne Trehu of Oregon 
State University. 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 single GI airgun, a 
3.5 and 12 kHz sub-bottom profiler will be used continuously throughout 
the cruise, and a magnetometer may be run on the transit between OBS 
locations.

Vessel Specifications

    The Wecoma 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 ship is powered by a 
single 3,000-hp EMD diesel engine driving a single, controllable-pitch 
propeller through a clutch and reduction gear, and an electric 350-hp 
azimuthing bow thruster. An operations speed of 11.1 km/hour (6 knots) 
will be used during seismic acquisition. When not towing seismic survey 
gear, the Wecoma cruises at 22.2 km/hour (12 knots) and has a maximum 
speed of 26 km/hour (14 knots). It has a normal operating range of 
approximately 13,300 km. The Wecoma 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 Wecoma will tow a single GI airgun, 
with a volume of 45 in\3\, and a 300 m long streamer containing 
hydrophones along predetermined lines. Seismic pulses will be emitted 
at intervals of 10 seconds. At a speed of 6 knots (11.1 km/hour), the 
10 second shot spacing corresponds to a shot interval of approximately 
31 m (101.7 ft).
    The generator chamber of the GI airgun, the one responsible for 
introducing the sound pulse into the ocean, is 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. The 45 in\3\ GI airgun will be towed 21 m (68.9 ft) behind 
the Wecoma at a depth of 4 m (13.1 ft). The sound pressure field of 
that GI airgun variation at a tow depth of 2.5 m has been modeled by 
Lamont-Doherty Earth Observatory (L-DEO) in relation to distance and 
direction for the GI airgun.
    As the GI airgun is towed along the survey line, the towed 
hydrophone array in the 300 m streamer receives the reflected signals 
and transfers the data on the on-board processing system. Given the 
relatively short streamer length behind the vessel, the turning rate of 
the vessel while the gear is deployed is much higher than the limit of 
five degrees per minute for a seismic vessel towing a streamer of more 
typical length (much greater than 1 km). Thus, the maneuverability of 
the vessel is not limited much during operations.
    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 [mu]Pa (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.
    Received sound levels have been modeled by L-DEO for a number of 
airgun configurations, including one 45 in\3\ GI airgun, in relation to 
distance from the airgun(s) (see Figure 2 of SIO's application). The 
model does not allow for bottom interactions, and is most directly 
applicable to deep water. Based on modeling, estimates of the maximum 
distances from the GI airgun where sound levels of 190, 180, and 160 dB 
re 1 [mu]Pa (rms) are predicted to be received in deep (>1,000 m) water 
are shown in this Federal Register notice (reprinted from Table 1 of 
SIO's application). Because the model results are for a 2.5 m tow 
depth, the distances in Table 1 slightly underestimate the distances 
for the 45 in\3\ GI airgun towed at 4 m depth.
Sub-bottom Profiler
    Along with the GI airgun operations, one additional acoustical data 
acquisition system will be operated throughout the cruise. The ocean 
floor will be mapped with a Knudsen Engineering Model 320BR 12 kHz and 
3.5 kHz sub-bottom profiler (SBP). Multi-beam sonar will not be used.
    The Knudsen Engineering Model 320BR SBP is a dual-frequency 
transceiver designed to operate at 3.5 and/or 12 kHz. It is used to 
provide data about the sedimentary features that occur below the sea 
floor. The energy from the sub-bottom profiler is directed downward via 
a 12 kHz transducer (EDO 323B) or a 3.5 kHz array of 16 ORE 137D 
transducers in a 4x4 arrangement. The maximum power output of the 320BR 
is 10 kilowatts for the 3.5 kHz section and 2 kilowatts for the 12 kHz 
section.
    The pulse length for the 3.5 kHz section of the 320 BR is 0.8-24 
ms,

[[Page 34717]]

controlled by the system operator in regards to water depth and 
reflectivity of the bottom sediments, and will usually be 12 or 24 ms 
in this survey. The system produces one sound pulse and then waits for 
its return before transmitting again. Thus, the pulse interval is 
directly dependent upon water depth, and in this survey is 4.5-8 
seconds. Using the Sonar Equations and assuming 100 percent efficiency 
in the system (impractical in real world applications), the source 
level for the 320BR is calculated to be 211 dB re 1 Pam. In practical 
operation, the 3.5 kHz array is seldom driven at more than 80 percent 
of maximum, usually less than 50 percent.
Safety Radii
    NMFS has determined that for acoustic effects, using acoustic 
thresholds in combination with corresponding safety radii is an 
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 
dB re 1 [mu]Pa (rms) level for cetaceans and 190 dB re 1 [mu]Pa (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 sound 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, SIO's application sets forth, and 
NMFS is using, the more conservative 180 and 190 dB re 1 [mu]Pa (rms) 
criteria. NMFS also considers 160 dB re 1 [mu]Pa (rms) as the criterion 
for estimating the onset of Level B harassment from acoustic sources 
like impulse sounds used in the seismic survey.
    Empirical 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., 2004). Although the results are limited the 
data showed that radii around the airguns where the received level 
would be 180 dB re 1 [mu]Pa (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 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., 2004). 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 23 m (75.5 ft) and 8 m (26 ft), respectively.
    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., 2004). During the proposed cruise, similar factors will be applied 
to derive appropriate shallow water radii from the modeled deep water 
radii for the GI airgun (see Table 1 below).
    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 35 m (115 ft) and 12 m (39.4 ft), 
respectively (see Table 1 below).

 Table 1--Predicted distances to Which Sound Levels [gteqt]190, 180, and 160 dB re 1 [mu]Pa 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
----------------------------------------------------------------------------------------------------------------
Single GI airgun 45 in\3\.....               4  Deep (>1,000 m).               8              23             220
                                ..............  Intermediate                  12              35             330
                                                 (100-1,000 m).
                                ..............  Shallow (<100 m)              95             150             570
----------------------------------------------------------------------------------------------------------------

Dates, Duration, and Region of Activity

    The Wecoma is scheduled to depart from Newport, Oregon, on July 14, 
2009, and to return on July 20, 2009. The GI airgun will be used for 
approximately two hours at each of 16 OBS locations. The program will 
consist of approximately 7 days of seismic acquisition. The exact dates 
of the activities may vary by a few days because of weather conditions, 
repositioning, streamer operations, and adjustments, GI airgun 
deployment, or the need to repeat some lines if data quality is 
substandard. The seismic surveys will take place off the Oregon coast 
in the northeastern Pacific Ocean (see Figure 1 of SIO's application). 
The overall area within which the seismic surveys will occur is located 
between approximately 44[deg] and 45[deg] N. and 124.5[deg] and 
126[deg] W. (see Figure 1 of SIO's application). The surveys will take 
place in water depths just less than 100 m and to almost 3,000 m, 
entirely

[[Page 34718]]

within the Exclusive Economic Zone (EEZ) of the U.S.

Comments and Responses

    A notice of receipt of the SIO application and proposed IHA was 
published in the Federal Register on May 26, 2009 (74 FR 24799). 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 the NMFS issue the 
requested authorization provided that the authorization includes 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 recommendations and 
has included requirements to these effects in the IHA.
    Comment 2: The Commission recommends that the NMFS issue the 
requested authorization provided that the NMFS clarify when the use of 
night vision devices (NVDs) will be required and provide additional 
justification for its implied conclusion that observers will be able to 
achieve a high nighttime detection rate.
    Response: NVDs are used at night and during some low-light 
conditions. 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 (492 to 820 ft) using NVDs and about 30 m 
(98 ft) with the naked eye. Depending on water depth, the relevant 
safety zones for this survey range from 8 m to 150 m (26 to 492 ft) 
(see Table 1 above) and NMFS believes that MMVOs are effective at 
visually detecting marine mammals within these distances.
    Marine seismic surveys may continue into night and low-light hours 
if such segment(s) of the survey is 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 MMVOs on duty aboard the Wecoma. NMFS has included a 
requirement to this effect in the IHA issued to SIO.
    Comment 3: The Commission recommends that the NMFS issue the 
requested authorization provided that the authorization requires that 
operations be suspended immediately, pending review by the 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 concurs with the Commission's recommendations and 
has included a requirement to this effect in the IHA.

Description of Marine Mammals in the Proposed Activity Area

    A total of 32 marine mammal species may occur or have been 
documented to occur in the marine waters off Oregon and Washington, 
excluding extralimital sightings or strandings (Fiscus and Niggol, 
1965; Green et al., 1992, 1993; Barlow, 1997, 2003; Mangels and 
Gerrodette, 1994; Von Saunder and Barlow, 1999; Barlow and Taylor, 
2001; Buchanan et al., 2001; Calambokidis et al., 2004; Calambokidis 
and Barlow, 2004). The species include 19 odontocetes (toothed 
cetaceans, such as dolphins), 7 mysticetes (baleen whales), 5 
pinnipeds, and sea otters. Six of the species that may occur in the 
project area are listed under the Endangered Species Act (ESA) as 
Endangered, including sperm, humpback, sei, fin, blue, and North 
Pacific right whales. Another species, the Steller sea lion, is listed 
as Threatened and may occur in the project area.
    The study area is located approximately 25 to 110 km (15.5 to 68.4 
mi) offshore from Oregon over water depths from just less than 100 m to 
almost 3,000 m. Two of the 32 species, gray whales and sea otters, are 
not expected in the project area because their occurrence off Oregon is 
limited to very shallow, coastal waters. Three other species, 
California sea lions, Steller sea lions, and harbor seals, are mainly 
coastal, and would be rare at most at the OBS locations. Information on 
the habitat, abundance, and conservation status of the species that may 
occur in the study area is given in Table 2 (below, see Table 2 of 
SIO's application). Vagrant ringed seals, hooded seals, and ribbon 
seals have been sighted or stranded on the coast of California (see 
Mead, 1981; Reeves et al., 2002) and presumably passed through Oregon 
waters. A vagrant beluga whale was seen off the coast of Washington 
(Reeves et al., 2002). Those seven species are not addressed in detail 
in the summaries in SIO's application.
    The six species of marine mammals expected to be most common in the 
deep pelagic or slope waters of the project area, where most of the 
survey sites are located, include the Pacific white-sided dolphin, 
northern right whale dolphin, Risso's dolphin, short beaked common 
dolphin, Dall's porpoise, and northern fur seal (Green et al., 1992, 
1993; Buchanan et al., 2001; Barlow, 2003; Barlow and Forney, 2007; 
Carretta et al., 2007). The fin whale, Dall's porpoise, and the 
northern elephant seal were the species sighted most often off Oregon 
and Washington during the ORCAWALE 2008 surveys (NMFS, 2008).
    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 was included in the notice of the proposed 
IHA (74 FR 24799, May 26, 2009) and may be found in SIO's application.

[[Page 34719]]



 Table 2--The Occurrence, Habitat, Regional Abundance, Best and Maximum Density Estimates, Number of Marine Mammals That Could be Exposed to Sound Level
 at or Above 160dB re 1[mu]Pa, Best Estimate of Number of Individuals Exposed, and Best Estimate of Number of Exposures per Marine Mammal in or Near the
                                         Proposed Low-Energy Seismic Survey Area in the Northeast Pacific Ocean
                                                [See Tables 2-4 in SIO's application for further detail]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                            Percent of
                                                                                           Density/1000    Density/1000      Number of       estimated
               Species                          Habitat            Regional population     km\2\ (best)     km\2\ (max)   indiv. exposed    population
                                                                         size \e\               \b\             \c\         to >=160 dB     exposed to
                                                                                                                                             >=160 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Mysticetes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Eastern Pacific gray whale             Coastal.................  17,752.................           NA              NA                  0            0
 (Eschrichtius robustus).
North Pacific right whale (Eubalaena   Pelagic and coastal.....  NA (Probably less than             0               0                  0            0
 japonica).                                                       100) \f\.
Humpback whale (Megaptera              Mainly nearshore waters   1,396..................            0.69            1.50               1            0.07
 novaeangliae).                         and banks.
Minke whale (Balaenoptera              Pelagic and coastal.....  898....................            0.68            1.1                0            0
 acutorostrata).
Sei whale (Balaenoptera borealis)....  Primarily offshore,       43.....................            0.13            0.5                1            2.33
                                        pelagic.
Fin whale (Balaenoptera physalus)....  Continental slope,        3,454..................            0.95            1.3                1            0.03
                                        mostly pelagic.
Blue whale (Balaenoptera musculus)...  Pelagic and coastal.....  1,186..................            0.19            0.4                1            0.08
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Odontocetes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale (Physeter macrocephalus).  Usually pelagic and deep  2,265..................            1.39            0.58               1            0.04
                                        seas.
Pygmy sperm whale (Kogia breviceps)..  Deep waters off shelf...  NA.....................            1.24            2.8                1           NA
Dwarf sperm whale (Kogia sima).......  Deep waters off the       NA.....................            0               0                  0            0
                                        shelf.
Cuvier's beaked whale (Ziphius         Pelagic.................  2,171..................            0               0                  0            0
 cavirostris).
Baird's beaked whale (Berardius        Pelagic.................  313....................            1.64            0.60               0            0
 bairdii).
Blainville's beaked whale (Mesoplodon  Slope, offshore.........  1,024 \g\..............            0               0                  0            0
 densirostris).
Hubb's beaked whale (Mesoplodon        Slope, offshore.........  1,024 \g\..............            0               0                  0            0
 carlhubbsi).
Stejneger's beaked whale (Mesoplodon   Slope, offshore.........  1,024 \g\..............            0               0                  0            0
 stejnegeri).
Offshore bottlenose dolphin (Tursiops  Offshore, slope.........  3,257..................            0               0                  0            0
 truncatus).
Striped dolphin (Stenella              Off continental shelf...  23,883.................            0.04            0.1                0            0
 coeruleoalba).
Short-beaked common dolphin            Shelf and pelagic,        487,622................           14.14           35                  4           <0.01
 (Delphinus delphis).                   seamounts.
Pacific white-sided dolphin            Offshore, slope.........  25,233.................           24.84           33.2                6            0.02
 (Lagenorhynchus obliquidens).
Risso's dolphin (Grampus griseus)....  Shelf, slope, seamounts.  12,093.................           12.91           17.3                3            0.02
Northern right whale dolphin           Slope, offshore waters..  15,305.................           19.39           26.7                5            0.03
 (Lissodelphis borealis).
False killer whale (Pseudorca          Pelagic, occasionally     NA.....................            0               0                  0            0
 crassidens).                           inshore.
Killer whale (Orcinus orca)..........  Widely distributed......  422 (Offshore).........            1.62            2.7                0            0
Short-finned pilot whale               Mostly pelagic, high-     245....................            0               0                  0            0
 (Globicephala macrorhynchus).          relief topography.
Harbor porpoise (Phocoena phocoena)..  Coastal and inland        37,745 (OR/WA).........           NA              NA                  0            0
                                        waters.

[[Page 34720]]

 
Dall's porpoise (Phocoenoides dalli).  Shelf, slope, offshore..  57,549.................          150.17          250.9               39            0.07
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                        Pinnipeds
--------------------------------------------------------------------------------------------------------------------------------------------------------
Northern fur seal (Callorhinus         Pelagic, offshore.......  721,935 \f\............           10             100                  3           <0.01
 ursinus).
California sea lion (Zalophus          Coastal, shelf..........  238,000................           NA              NA                  2           <0.01
 californianus).
Harbor seal (Phoca vitulina            Coastal.................  24,732 (OR/WA).........           13              NA                  1           <0.01
 richardsi).
Steller sea lion (Eumetopias jubatus)  Coastal, shelf..........  48,519 Eastern U.S. \f\           11              NA                  1           <0.01
Northern elephant seal (Mirounga       Coastal, pelagic when     124,000 (CA)...........           20             200                  5            0.01
 angustirostris).                       migrating.
--------------------------------------------------------------------------------------------------------------------------------------------------------
NA--Data not available or species status was not assessed, CA = California, OR = Oregon, WA = Washington.
\a\ U.S. Endangered Species Act: EN = Endangered, T = Threatened, NL = Not listed.
\b\ Best estimate as listed in Table 3 of the application.
\c\ Maximum estimate as listed in Table 3 of the application.
\d\ The numbers of at-sea sightings of California sea lions and northern elephant seals were too small to provide meaningful density estimates (Bonnell
  et al., 1992); density of northern elephant seals was estimated based on sightings during the ORCAWALE 2008 surveys.
\e\ Abundance given for U.S. Eastern North Pacific, or CA/OR/WA stock, whichever is included in the 2007 U.S. Pacific Marine Mammal Stock Assessments
  (Carretta et al., 2007), unless otherwise stated.
\f\ Angliss and Outlaw (2008).
\g\ All mesoplodont whales.

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). With the possible exception of some 
cases of temporary threshold shift in harbor seals, it is unlikely that 
the project would result in any cases of temporary or especially 
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 24799, May 26, 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 SIO's application and associated EA.
    The notice of the proposed IHA also included a discussion of the 
potential effects of the 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 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 
sub-bottom profiler sonar system is not likely to result in the 
harassment of marine mammals.

Estimated Take by Incidental Harassment

    The notice of the proposed IHA (74 FR 24799, May 26, 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 SIO'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, 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. The estimates of ``take by harassment'' are 
based on (1) data concerning marine mammal densities (numbers per unit 
area) obtained during surveys off Oregon and Washington during 1996, 
2001, and 2005 (cetaceans), or 1989 to 1990 (pinnipeds) by NMFS 
Southwest Fisheries Science Center (SWFSC), and (2) estimates of the 
size of the 160 dB isolpeths where takes could potentially occur from 
the proposed seismic survey off the coast of Oregon in the northeastern 
Pacific Ocean.
    Extensive systematic aircraft and ship-based surveys have been 
conducted for marine mammals offshore of Oregon and Washington (Bonnell 
et al., 1992; Green et al., 1992, 1993;

[[Page 34721]]

Barlow 1997, 2003; Barlow and Taylor, 2001; Calambokidis and Barlow, 
2004; Barlow and Forney in prep.). The most comprehensive and recent 
density data available for cetacean species in slope and offshore 
waters of Oregon are from the 1996, 2001, and 2005 NMFS SWFSC 
``ORCAWALE'' or ``CSCAPE'' ship surveys as synthesized by Barlow and 
Forney (2007). The surveys were conducted up to approximately 550 km 
(342 mi) offshore from June or July to November or December. 
Systematic, offshore, at-sea survey data for pinnipeds are more 
limited. The most comprehensive such studies are reported by Bonnell et 
al. (1992) based on systematic aerial surveys conducted in 1989-1990.
    Oceanographic conditions, including occasional El Ni[ntilde]o and 
La Ni[ntilde]a events, influence the distribution and numbers of marine 
mammals present in the Northeast Pacific Ocean, including Oregon, 
resulting in considerable year-to-year variation in the distribution 
and abundance of many marine mammal species (Forney and Barlow, 1998; 
Buchanan et al., 2001; Escorza-Trevi[ntilde]o, 2002; Ferrero et al., 
2002; Philbrick et al., 2003). Thus, for some species the densities 
derived from recent surveys may not be representative of the densities 
that will be encountered during the proposed seismic survey. For this 
IHA application, cruise reports from the ORCAWALE 2008 surveys (NMFS, 
2008) were inspected to assess whether there were any observable 
changes from the previous surveys of the same area.
    Table 3 of SIO's application (reprinted as Table 2 in this Federal 
Register notice) gives the average and maximum densities for each 
species of cetacean reported off Oregon and Washington, corrected for 
effort, based on the densities reported for the 1996, 2001, and 2005 
surveys (Barlow and Forney, 2007). The densities from those studies had 
been corrected by the original authors for both detectability bias and 
availability bias. Detectability bias is associated with diminishing 
sightability with increasing lateral distance from the trackline. 
Availability bias refers to the fact that there is <100 percent 
probability of sighting an animal that is present along the survey 
trackline.
    Table 3 of SIO's application (Table 2 in this Federal Register 
notice) also includes mean density information for three of the five 
pinniped species that occur off Oregon and Washington and mean and 
maximum densities for one of those species, from Bonnell et al. (1992). 
Densities were not calculated for the other two species because of the 
small number of sightings on systematic transect surveys. One of those, 
the northern elephant seal, was the dominant seal sighted during the 
ORCAWALE 2008 surveys (29 of 33 pinnipeds sighted off Oregon and 
Washington), so it was included at a density set at twice that of the 
northern fur seal, the other species sighted during the ORCAWALE 2008 
surveys.
    It should be noted that the following estimates of ``takes by 
harassment'' assume that the surveys will be undertaken and completed; 
in fact, the planned number of line kms has been increased by 25 
percent to accommodate lines that may need to be repeated, equipment 
testing, etc. 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 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 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 unlikely.
    There is some uncertainty about the representativeness of the data 
and the assumption 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. Best and maximum estimates are based on the average and 
maximum estimates of densities reported primarily by Barlow and Forney 
(2007) and Bonnell et al. (1992) described above. The estimated numbers 
of potential individuals exposed are presented below based on the 160 
dB re 1 [mu]Pa (rms) Level B harassment criterion for all cetaceans and 
pinnipeds. It is assumed that a marine mammal exposed to airgun sounds 
this strong 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 >=160 dB re 1 [mu]Pa (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 proposed 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. The best 
estimates in this section are based on the averages of the densities 
from the 1996, 2001, and 2005 NMFS surveys, and maximum estimates are 
based on the highest of the three densities. Table 4 of SIO's 
application and Table 2 of this Federal Register notice show 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 >=160 dB re 1 [mu]Pa (rms) was calculated by multiplying:
     The expected species density, either ``mean'' (i.e., best 
estimate) or ``maximum,'' times; and
     The area anticipated 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 (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. In 
the proposed survey, there is minimal overlap (5 percent for 160 dB), 
so virtually no marine mammal would be ensonified above those 
thresholds more than once.
    Applying the approach described above, approximately 208 km\2\ 
(80.3 mi\2\) would be within the 160 dB isopleth on one or more 
occasions during the surveys at all 16 OBS locations. For inshore OBS 
locations, approximately 60 km\2\ (23 mi\2\) would be within the 160 dB 
isopleths; that area was used for calculations for the pinniped species 
that could occur only at those locations. This approach does not allow 
for turnover in the mammal populations in the study area during the 
course of the surveys. 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 Wecoma 
approaches, in response to increasing sound levels prior to the time 
the levels reach 160 dB. Another way of interpreting the estimates that 
follow in Table 3 (below) is that they represent the number of 
individuals that are expected (in the absence of a seismic program) to 
occur in the waters that will be exposed to >=160 dB re 1 [mu]Pa (rms).

[[Page 34722]]

    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 the 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 24799, May 26, 2009) 
and may be found in SIO'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 SIO's Proposed Seismic Survey Off Oregon in July 2009. The Proposed Sound Source is a Single GI
  Airgun. Received Levels are Expressed in dB re 1 [mu]Pa (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 2-4 in SIO's application for further detail]
----------------------------------------------------------------------------------------------------------------
                                                                     Number of       Number of       Approx. %
                                                                    individuals     individuals      Regional
                             Species                              exposed (best)   exposed (max)    Population
                                                                        \1\             \1\         (best) \2\
----------------------------------------------------------------------------------------------------------------
                                                   Mysticetes
----------------------------------------------------------------------------------------------------------------
Eastern Pacific gray whale (Eschrichtius robustus)..............               0               0            0
North Pacific right whale (Eubalaena japonica)..................               0               0            0
Humpback whale (Megaptera novaeangliae).........................               1               2            0.07
Minke whale (Balaenoptera acutorostrata)........................               0               0            0
Sei whale (Balaenoptera borealis)...............................               1               0            2.33
Fin whale (Balaenoptera physalus)...............................               1               1            0.03
Blue whale (Balaenoptera musculus)..............................               1               1            0.08
----------------------------------------------------------------------------------------------------------------
                                                   Odontocetes
----------------------------------------------------------------------------------------------------------------
Sperm whale (Physeter macrocephalus)............................               1               8            0.04
Pygmy sperm whale (Kogia breviceps).............................               0               1           NA
Dwarf sperm whale (Kogia sima)..................................               0               0            0
Cuvier's beaked whale (Ziphius cavirostris).....................               0               0            0
Baird's beaked whale (Berardius bairdii)........................               0               1            0
Blainville's beaked whale (Mesoplodon densirostris).............               0               0            0
Hubb's beaked whale (Mesoplodon carlhubbsi).....................               0               0            0
Stejneger's beaked whale (Mesoplodon stejnegeri)................               0               0            0
Mesoplodon sp. (unidentified) \3\...............................               0               1            0
Offshore bottlenose dolphin (Tursiops truncatus)................               0               0            0
Striped dolphin (Stenella coeruleoalba).........................               0               0            0
Short-beaked common dolphin (Delphinus delphis).................               4               9           <0.01
Pacific white-sided dolphin (Lagenorhynchus obliquidens)........               6               9            0.02
Northern right-whale dolphin (Lissodelphis borealis)............               5               7            0.02
Risso's dolphin (Grampus griseus)...............................               3               4            0.03
False killer whale (Pseudorca crassidens).......................               0               0           NA
Killer whale (Orcinus orca).....................................               0               1            0
Short-finned pilot whale (Globicephala macrorhynchus)...........               0               0            0
Harbor porpoise (Phocoena phocoena).............................               0               0            0
Dall's porpoise (Phocoenoides dalli)............................              39              65            0.07
----------------------------------------------------------------------------------------------------------------
                                                    Pinnipeds
----------------------------------------------------------------------------------------------------------------
Northern fur seal (Callorhinus ursinus).........................               3              26           <0.01
California sea lion (Zalophus californianus)....................               2              NA           <0.01
Steller sea lion (Eumetopias jubatus)...........................               1              NA           <0.01
Harbor seal (Phoca vitulina richardsi)..........................               1              NA           <0.01
Northern elephant seal (Mirounga angustirostris)................               5              52            0.01
----------------------------------------------------------------------------------------------------------------
NA--Data not available or species status was not assessed.
\1\ Best estimate and maximum estimate density are from Table 3 of SIO's application.
\2\ Regional population size estimates are from Table 2 (above).

    Table 4 of SIO's application (Table 3 in this Federal Register 
notice) 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 [mu]Pa (rms) during the 
different legs of the seismic survey if no animals move away from the 
survey vessel.
    The ``best'' 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 [mu]Pa (rms) (but below Level A harassment thresholds) 
during the survey is shown in Table 4 of SIO's application and Table 3 
(shown above). The maximum estimates have been requested by SIO. The 
``best estimate'' total includes 4 baleen whale individuals. These 
estimates were derived from the best density estimates calculated for 
these species in the area (see Table 4 of SIO's application). In 
addition, 1 sperm whale (0.35 percent of

[[Page 34723]]

the regional population) as well as 0 beaked whales (0 percent of the 
regional population). Based on the best estimates, most (93 percent) of 
the marine mammals potentially exposed are dolphins and porpoises; 
short-beaked common, Pacific white-sided, Northern right-whale, Risso's 
dolphins and Dall's porpoises are estimated to be the most common 
species in the area, with best estimates of 4 (<0.01 percent of the 
regional population), 6 (0.02 percent), 5 (0.03 percent), 3 (0.02 
percent), and 39 (0.07 percent) exposed to greater than or equal to 160 
dB re [mu]Pa (rms), respectively. The remainder of the marine mammals 
that may be potentially exposed are pinnipeds; Northern fur, harbor, 
and Northern elephant seals, and Steller sea lions are estimated to be 
the most common species in the area, with best estimates of 3 (<0.01 
percent), 1 (<0.01 percent), 5 (0.01 percent), and 1 (<0.01 percent) 
exposed to greater than or equal to 160 dB re [mu]Pa (rms), 
respectively. Haul-outs of California sea lions and harbor seals are 
known to be located in the Newport, Oregon area. All of these numbers 
are considered small relative to the population sizes of the affected 
species or stocks.

Potential Effects on 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 24799, May 26, 2009). Based on the discussion in the 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 SIO seismic survey will not result in any permanent impact on 
habitats used by marine mammals, or on 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.

Subsistence Activities

    There is no subsistence hunting for marine mammals in the waters 
off of the coast of Oregon 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 SIO and 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 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 that will be adopted during the proposed survey 
include:
    (1) Speed or course alteration, provided that doing so will not 
compromise operational safety requirements;
    (2) GI airgun shut-down procedures;
    (3) Special procedures for situations or species of particular 
concern, e.g., emergency shut-down procedures for North Pacific right 
whales, avoidance of concentrations of beaked whales (if visually 
sighted), and minimization of approaches to slopes, if possible, to 
avoid beaked whale habitat; and
    (4) Additional mitigation measures (see ``additional mitigation 
measures'' below).
    Two other common mitigation measures, airgun array power-down and 
airgun array ramp-up, are not possible because only one, low-volume GI 
airgun will be used for the surveys. The thresholds for estimating 
Level A harassment take are also used in connection with proposed 
mitigation.

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 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 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 that corresponds to the 180 or 
190 dB re 1 [mu]Pa (rms) isopleths, depending on whether the animal is 
a cetacean or a pinniped. The MMVOs will continue to maintain watch to 
determine when the animal(s) are outside the EZ, and airgun operations 
will not resume until the animal has left that EZ. The predicted 
distances for the 180 and 190 dB EZs are listed according to the water 
depth in Table 1 above.
    During seismic operations off of the coast of Oregon, at least two 
MMVOs will be based aboard the Wecoma. MMVOs will be appointed by SIO 
with NMFS concurrence. At least one MMVO will monitor the EZ for marine 
mammals during ongoing daytime GI airgun operations and nighttime 
startups of the airguns. MMVO(s) will be on duty in shifts no longer 
than 4 hours duration. 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 Wecoma is a suitable platform for marine mammal observations. 
Observing stations will be on the bridge wings, with observers' eyes 
approximately 6.5 m (21.3 ft) above the waterline and a 180 degree view 
outboard from either side, on the whaleback deck in front of the 
bridge, with observers' eyes approximately 7 m (23 ft) above the 
waterline and approximately 200 degrees view forward, and on the aft 
control station, with observer's eyes approximately 5.5 m (18 ft) above 
the waterline and a approximately 180 degree view aft that includes the 
40 m (131 ft) (180 dB) radius area around the GI airgun. The eyes of 
the bridge watch will be at a height of approximately 6.5 m; MMOs will 
move to the enclosed bridge during any inclement weather.
    During the daytime, the MMVO(s) will scan the area around the 
vessel systematically with reticle binoculars (e.g., 7x50), Big-eye 
binoculars (25x150), optical range finders, and with the naked eye. 
During darkness, night vision devices will be available, when required. 
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 and the relative 
movement of the vessel and animal, and if safety and scientific 
objectives allow, the vessel speed and/or course may be adjusted to 
minimize the likelihood of the animal entering the EZ. Typically, 
during seismic operations, major course and speed adjustments are often 
impractical when towing long seismic streamers and

[[Page 34724]]

large source arrays, but are possible in this case because only one GI 
airgun and a short streamer will be used.
    Shut-down Procedures--The operating airguns(s) will be shut-down if 
a marine mammal is detected within or approaching the EZ for the single 
GI airgun source. Following a shut-down, GI airgun activity will not 
resume until the marine mammal is outside the EZ for the full array. 
The animal will be considered to have cleared the EZ if it:
     Is visually observed to have left the EZ;
     Has not been seen within the EZ for 15 min in the case of 
species with shorter dive durations--small odontocetes (i.e., dolphins) 
and pinnipeds; and
     Has not been seen within the EZ for 30 min in the case of 
species with longer dive durations--mysticetes and large odontocetes 
(i.e., sperm, pygmy sperm, dwarf sperm, killer, and beaked whales).
    Procedures for Situations or Species of Particular Concern--Special 
mitigation procedures will be used for certain situations and species 
as follows:
    (1) The GI airgun will be shut-down if a North Pacific right whale 
is sighted at any distance from the vessel;
    (2) To avoid beaked whale habitat, approach to slopes will be 
minimized, if possible, during the proposed survey. Avoidance of airgun 
operations over or near submarine canyons has become a standard 
mitigation measure, but there are none within or near the study area. 
Four of the 16 OBS locations are on the continental slope, but the GI 
airgun is low volume and it will operate only for a short time 
(approximately 2 hours at each location).
    (3) If visually sighted, avoidance of concentrations of beaked 
whales.

Additional Mitigation Measures

    (1) To the maximum extent practicable, SIO will schedule seismic 
operations in inshore or shallow waters during daylight hours, and OBS 
operations during nighttime hours.
    SIO and NSF will coordinate the planned marine mammal monitoring 
program associated with the seismic survey off the coast of Oregon with 
applicable U.S. agencies (e.g., NMFS), and will comply with their 
requirements.

Reporting

MMVO Data and Documentation

    MMVOs 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 shutdown of 
the seismic source when a marine mammal or sea turtle is within or near 
the EZ.
    When a sighting is made, the following information about the 
sighting will be recorded:
    (1) Species, group size, and 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, visibility, cloud cover, and sun glare.
    The data listed (time, location, etc.) will also be recorded at the 
start and end of each observation watch, and during a watch whenever 
there i