Small Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the Gulf of Alaska, September 2008, 52950-52959 [E8-21346]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 73, Number 178 (Friday, September 12, 2008)]
[Notices]
[Pages 52950-52959]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-21346]


-----------------------------------------------------------------------

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XI15


Small Takes of Marine Mammals Incidental to Specified Activities; 
Marine Geophysical Survey in the Gulf of Alaska, September 2008

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

ACTION:  Notice; issuance of incidental take authorization.

-----------------------------------------------------------------------

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 Lamont-Doherty Earth 
Observatory (L-DEO), a part of Columbia University, for the take of 
marine mammals, by Level B harassment only, incidental to conducting a 
marine seismic survey in the Gulf of Alaska during September, 2008.

DATES: Effective September 10, 2008, through October 31, 2008.

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 U.S. 
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 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 (where relevant), 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 
marine mammals. Within 45 days of the close of the comment period, NMFS 
must either approve or deny the authorization.

Summary of Request

    On April 10, 2008, NMFS received an application from L-DEO for the 
taking, by Level B harassment only, of small numbers of 20 species of 
marine mammals incidental to conducting, under a cooperative agreement 
with the National Science Foundation (NSF), a marine seismic survey in 
the Gulf of Alaska during September, 2008. The purpose of the research 
program was outlined in NMFS' notice of the proposed IHA (73 FR 45407, 
August 5, 2008).

Description of the Activity

    The seismic survey will involve one source vessel, the R/V Marcus 
G. Langseth (Langseth), which will occur offshore from the Saint Elias 
Mountains. The Langseth will deploy an array of 36 airguns (6,600 
in\3\) as an energy source and, at times, a receiving system consisting 
of a 8-km (5-mi) towed hydrophone streamer and/or Ocean Bottom 
Seismometers (OBSs). The streamer will be towed at a depth of 7 m (23 
ft). The OBSs are housed in 43-cm diameter glass spheres that have a 
gross weight of approximately 45 kg (99 lbs). As the airgun array is 
towed along the survey lines, the hydrophone streamer and/or OBSs will 
receive the returning acoustic signals and transfer the data to the on-
board processing system.
    The Langseth is expected to depart Astoria, Oregon on approximately 
September 10, 2008 for the study area in the GOA (see Figure 1 of L-
DEO's application). The airgun array is expected to operate for a total 
of ~200-250 hours. With OBS deployment and retrieval, the length of the 
survey will be ~18 days. The overall area within which the STEEP survey 
will take place is located at ~58-60.5[deg] N, 138-146[deg] W (see 
Figure 1 of L-DEO's application). The proposed survey will be conducted 
in water depths from <100 m to >3,000 m (<330 to >9,840 ft) entirely 
within the territorial waters and Exclusive Economic Zone (EEZ) of the 
United States. The exact dates of the activities depend upon logistics, 
as well as weather conditions and/or the need to repeat some lines if 
data quality is substandard.
    The primary marine seismic survey will consist of two long transect 
lines that will cross each other (Figure 1 of L-DEO's application). For 
the longer line paralleling the shoreline, a seismic reflection-
refraction profile will be shot using the hydrophone streamer as well 
as 25 OBSs deployed on the seafloor and 60 Texan seismometers deployed 
on land across the toe of the Bering Glacier. A reflection-refraction 
profile will also be obtained from the slightly shorter line that is 
perpendicular to the shoreline using the hydrophone streamer as well as 
17 OBSs; this line will be shot twice if time allows. Both of these 
lines will have a shot spacing

[[Page 52951]]

of 50 m (164 ft, 20 seconds); if the onshore-offshore line is shot 
twice, the shot interval used during the second run will be 150 m (492 
ft, 60 s). During the reflection-refraction profiling, the airgun array 
will be towed at a depth of 9 m. In addition, two reflection-only 2-
dimensional (2-D) seismic grids will be shot; the western grid is 
located approximately 150 km (93 mi) from shore whereas the eastern 
grid is located nearshore (see Figure 1 in L-DEO's application). The 
shot spacing for these grids will be 50 m (164 ft) and the airgun array 
will be towed at a depth of 9 m. No OBSs will be deployed during 
reflection-only profiling. There will be additional operations 
associated with equipment testing, startup, line changes, and repeat 
coverage of any areas where initial data quality is sub-standard. In L-
DEO's calculations, 25 percent has been added to the line total for 
those additional operations.
    The planned seismic survey (excluding the 25 percent contingency) 
will consist of 1,909 km of survey lines including turns (see Figure 1 
in L-DEO's application). Most of this effort (923 km or 574 mi) will 
take place in intermediate water depths of 100-1,000 m and in water 
depths >1,000 m deep (812 km or 504 mi), and a smaller portion (174 km 
or 108 mi) will take place in water <100 m deep.
    All planned geophysical data acquisition activities will be 
conducted by L-DEO with on-board assistance by the scientists who have 
proposed the study. The scientific team is headed by Dr. Sean Gullick 
of the University of Texas at Austin Institute for Geophysics (UTIG) 
and also includes Drs. G. Christesen, P. Mann, and H. Van Avendonk of 
UTIG. The vessel will be self-contained, and the crew will live aboard 
the vessel for the entire cruise.
    In addition to the operations of the airgun array, a multibeam 
echosounder (MBES) will be operated from the Langseth continuously 
throughout the STEEP cruise. Also, a sub-bottom profiler (SBP) will be 
operated by the Langseth during most of the survey.
    A more detailed description of the authorized action, including 
vessel and acoustic source specifications, was included in the proposed 
IHA notice (73 FR 45407, August 5, 2008).

Safety Radii

    L-DEO estimated the safety radii around their operations using a 
model and by adjusting the model results based on empirical data 
gathered in the Gulf of Mexico in 2003. Additional information 
regarding safety radii in general, how the safety radii were 
calculated, and how the empirical measurements were used to correct the 
modeled numbers may be found in NMFS' proposed IHA notice (73 FR 45407, 
August 5, 2008) and Section I and Appendix A of L-DEO's application. 
Using the modeled distances and various correction factors, Table 1 
outlines the distances at which three rms sound levels (190 dB, 180 dB, 
and 160 dB) are expected to be received from the various airgun 
configurations in shallow, intermediate, and deep water depths.

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                        Predicted RMS Distances (m)
        Source and Volume              Tow Depth (m)            Water Depth      -----------------------------------------------------------------------
                                                                                          190 dB                  180 dB                  160 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
Single Bolt airgun                ......................  Deep                    12                      40                      385
                                                         -----------------------------------------------------------------------------------------------
40 in\3\                          9                       Intermediate            18                      60                      578
                                                         -----------------------------------------------------------------------------------------------
                                  ......................  Shallow                 150                     296                     1050
--------------------------------------------------------------------------------------------------------------------------------------------------------
4 strings                         ......................  Deep                    300                     950                     6000
                                                         -----------------------------------------------------------------------------------------------
36 airguns                        9                       Intermediate            450                     1425                    6667
                                                         -----------------------------------------------------------------------------------------------
6600 in\3\                        ......................  Shallow                 2182                    3694                    8000
--------------------------------------------------------------------------------------------------------------------------------------------------------
4 strings                         ......................  Deep                    340                     1120                    7400
                                                         -----------------------------------------------------------------------------------------------
36 airguns                        12                      Intermediate            510                     1680                    8222
                                                         -----------------------------------------------------------------------------------------------
6600 in\3\                        ......................  Shallow                 2473                    4356                    9867
--------------------------------------------------------------------------------------------------------------------------------------------------------
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 during the STEEP survey in the Gulf of Alaska.

Comments and Responses

    A notice of receipt of the L-DEO application and proposed IHA was 
published in the Federal Register on August 5, 2008 ( 73 FR 45407). 
During the comment period, NMFS received comments from the Marine 
Mammal Commission (Commission). NMFS also received one comment from a 
private citizen. Following are the comments from the Commission, a 
private citizen, the Center for Regulatory Effectiveness (CRE), and 
NMFS' responses.
    Comment 1: The Commission recommends that NMFS provide additional 
justification for its proposed determination that the planned 
monitoring program will be sufficient to detect, with reasonable 
confidence, all marine mammals within or entering the identified safety 
zones; as such monitoring is essential for determining whether animals 
are being taken in unanticipated ways and unexpected numbers.
    Response: NMFS believes that the planned monitoring program will be 
sufficient to detect (using visual detection and PAM), with reasonable 
certainty, most marine mammals within or entering identified safety 
zones. This monitoring, along with the required mitigation measures 
(see below), will result in the least practicable adverse impact on the 
affected species or stocks and will result in a negligible impact on 
the affected species or stocks.
    The Langseth is utilizing a team of trained marine mammal observers 
(MMOs) to both visually monitor from the high observation tower of the 
Langseth and to conduct passive acoustic monitoring (PAM). However, 
there are limitations on marine mammal detection, and ramp-ups are 
required as a mitigation measure due to these limitations. This 
monitoring, along with the required mitigation measures (see below), 
will result in the least practicable adverse impact on the affected 
species or stocks and will result

[[Page 52952]]

in a negligible impact on the affected species or stocks.
    When stationed on the observation platform of the Langseth, the eye 
level will be approximately 17.8 m (58.4 ft) above sea level, so the 
visible distance (in good weather) to the horizon is 8.9 nm (16.5 km; 
the largest safety radii is 2.4 nm, 4.4 km). Big eyes are most 
effective at scanning the horizon (for blows), while 7 x 50 reticle 
binoculars are more effective closer in (MMOs also use a naked eye 
scan). Night vision devices (NVDs) will be used in low light 
situations. Additionally, MMOs will have a good view in all directions 
around the entire vessel. Also, nearly 90 percent of the survey 
transect lines are in intermediate or deep water depths, where the 
safety radii are all less than 1 nm (1.9 km).
    Theoretical detection distance of this PAM system is tens of 
kilometers. The PAM is operated both during the day and at night. 
Though it depends on the lights on the ship, the sea state, and thermal 
factors, MMOs estimated that visual detection is effective out to 
between 150 and 250 m (492 and 820 ft) using NVDs and about 30 m (98.4 
ft) with the naked eye. However, the PAM operates equally as 
effectively at night as during the day, especially for sperm whales and 
dolphins.
     The PAM has reliable detection rates out to 3 km (1.6 nm) and more 
limited ability out to 10s of km. The largest 180-dB safety radii (3.7 
km, 2 nm), which is the radii within which the Langseth is required to 
shut down if a marine mammal enters, are found when the 36-gun array is 
operating in shallow water at a 9 m (29.5 ft) tow depth. Only 174 km (9 
percent) of the total 1,909 km survey lines of the planned seismic 
survey (excluding 25 percent contingency) will take place in water less 
than 100 m deep (shallow water). The species most likely to be 
encountered in the waters of the Gulf of Alaska are Dall's porpoise and 
Pacific white-sided dolphins, which have relatively larger group sizes 
(2-20 animals for Dall's porpoises but even higher in some areas of the 
survey, 10-100 or more animals per group for Pacific white-sided 
dolphins), are not cryptic at the surface, and have relatively short 
dive times (6 minutes for dolphins), all which generally make them 
easier to visually detect. Other species that are likely to be 
encountered during the seismic survey include humpback, fin, and killer 
whales, have relatively long dive times; however, they are not cryptic 
at the surface, have large blows and distinct physical features, all 
which generally make them easier to visually detect. Furthermore, the 
vocalizations of most of these species are easily detected by the PAM. 
During the Maurice Ewing cruise in the GOM in 2003, MMOs detected 
marine mammals at a distance of approximately 10 km (5.4 nm) from the 
vessel and identified them to species level at approximately 5 km (2.7 
nm) from the vessel, though the bridge of that vessel was only 11 m (36 
ft) above the water (vs. the Langseth, which is more than 17 m (55.8 
ft) above sea level). All of the 180-dB safety radii for other water 
depths and tow depths and for the single 40 in\3\ airgun to be used 
during ramp-ups and power-downs (see below) are less than 2 km (1.1 
nm).
    The likelihood of visual detection at night is significantly lower 
than during the day, though the PAM remains just as effective at night 
as during the day. However, the Langseth will not be starting up the 
airguns unless the safety range is visible for the entire 30 minutes 
prior (i.e., not an night), and therefore in all cases at night, the 
airguns will already be operating, which NMFS believes will cause many 
cetaceans to avoid the vessel, which therefore will reduce the number 
likely to come within the safety radii. Additionally, all of the safety 
radii in intermediate and deep water depths are smaller than 3 km (1.6 
nm) and fall easily within the reliable detection capabilities of the 
PAM.
    Comment 2: The Commission recommends that observations be made 
during ramp-up procedures to gather data on its effectiveness as a 
mitigation measure.
    Response: The IHA requires that MMOs on the Langseth make 
observations for 30 minutes prior to ramp-up, during all ramp-ups, and 
during all daytime seismic operations and record the following 
information when a marine mammal is sighted:
    (I) Species, group size, age/size/sex categories (if determinable), 
behavior when first sighted and after initial sighting, heading (if 
consistent), bearing and distance from seismic vessel, sighting cue, 
apparent reaction to the airguns or vessel (e.g., none, avoidance, 
approach, paralleling, etc., and including responses to ramp-up), and 
behavioral pace; and
    (ii) Time, location, heading, speed, activity of the vessel 
(including number of airguns 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 
detected during ramp-up.
    Comment 3: The Commission recommends that the monitoring period 
prior to the initiation of seismic activities and to the resumption of 
airgun activities after a power-down be extended to one hour.
    Response: As the Commission points out, several species of deep-
diving cetaceans 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 Langseth is required to ramp-up, 
the time monitoring prior to start-up of any but the smallest array is 
effectively longer than 30 minutes (i.e., ramp-up will begin with the 
smallest gun in the array and airguns will be added in a sequence such 
that the source level of the array will increase in steps not exceeding 
approximately 6 dB per 5-min period over a total duration of 20-40 
min); (2) in many cases MMOs are making observations during times when 
sonar is not being operated and will actually be observing the area 
prior to the 30-min 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 the short time immediately prior to the pre-start-up 
monitoring, if an animal's maximum underwater time is 45 minutes, there 
is only a 1 in 3 chance that its last random surfacing would be prior 
to the beginning of the required 30 min- monitoring period.
    Comment 4: A member of the public opposes the issuance of permits 
to allow killing of marine mammals.
    Response: NMFS does not believe that the authorized activities will 
result in the death of any marine mammals, nor does this IHA authorize 
any marine mammal mortality.
    Comment 5: CRE states that there is no accompanying Environmental 
Impact Statement (EIS) for the GOA IHA, instead, there is only an EA. 
CRE asks NMFS if there is any continuing plan to prepare an EIS for the 
Langseth.
    Response: A Draft Programmatic EIS (Draft PEIS) is being prepared 
by NSF (not NMFS) for future seismic surveys on the Langseth. However, 
NMFS is a cooperating agency under NEPA in its preparation. It is NMFS' 
intention that the Draft PEIS currently being developed will be used to 
support, in whole, or in part, future MMPA actions relating to academic 
research on seismic surveys.

    Comment 6: CRE asks NMFS if there is any continuing plan to use the

[[Page 52953]]

Acoustic Integration Model (AIM) for the Langseth.
    Response: The use of AIM remains proposed for NSF's Draft PEIS to 
address potential impacts related to marine seismic research. 
Preparation of that EIS continues, and public comments will be 
solicited when the Draft PEIS is published. AIM was developed by and is 
proprietary to Marine Acoustics, Inc. The commentor correctly notes 
that this particular IHA application does not use AIM. This application 
was prepared for NSF, L-DEO, and NMFS by LGL, Ltd., Environmental 
Research Associates (LGL). In the application for the proposed seismic 
operations, LGL notes that it is using the line transect method to 
estimate marine mammal exposures and determine exclusion zones, 
consistent with applications for recent previous NSF-funded research 
seismic cruises.
    Comment 7: CRE requests that be any opportunity for public comment 
on AIM before NMFS issues AIM for the Langseth or for any other 
purpose.
    Response: The NSF Draft PEIS will make the use of AIM available for 
public comment. AIM itself will not be available for public comment as 
it is proprietary.
    Comment 8: CRE states that the GOA IHA application and the 
accompanying EA rely on both visual observers and PAM to monitor 
compliance with seismic safety radii requirements. Neither the IHA 
application nor the EA contain a record demonstrating that PAM is 
accurate and reliable for this purpose. CRE asks NMFS whether there is 
a record demonstrating PAM is sufficiently accurate and reliable to 
monitor compliance with seismic safety radii requirements and whether 
there is an opportunity for public comment on that subject.

    Response: It is unclear what the commentor means by the phrase 
``monitor compliance with seismic safety radii requirements.'' NMFS 
believes that visual observers and PAM are effective tools for 
monitoring marine mammals in the affected area during the seismic 
survey. PAM is required for monitoring on the Langseth (when 
practicable), but not for the implementation of mitigation measures. 
PAM is used by MMOs and the bioacoustician aboard the Langseth for the 
detection of vocalizing marine mammals. Any confirmed marine mammal 
vocalization detections using PAM are communicated to the visual 
observer(s) on watch to help alert the visual observers to the presence 
of vocalizing marine mammals in the survey area (not necessarily the 
safety radii). The use of PAM is therefore used in aid of the visual 
observers, who monitor the safety radii for presence of marine mammals. 
The detection of marine mammals in the vicinity of the array in turn 
triggers mitigation requirements.

Description of Marine Mammals in the Activity Area

    A total of 18 cetacean species, 3 species of pinnipeds, and the 
northern sea otter are known to or may occur in the GOA study area. 
Several of the species that may occur in the project area are listed as 
Endangered under the U.S. Endangered Species Act (ESA), including the 
sperm, humpback, North Pacific right whale, fin, and blue whale and the 
western stock of Steller sea lions. The eastern stock of Steller sea 
lions are listed at Threatened. Neither the southcentral and southeast 
Alaska population stocks of northern sea otters (Enhydra lutris 
kenyoni) are listed as Threatened or Endangered under the ESA nor 
depleted under the MMPA. The northern sea otter is under the 
jurisdiction of the U.S. Fish and Wildlife Service (USFWS) and 
therefore is not considered further in this analysis. There is little 
information on the distribution of marine mammals inhabiting the waters 
offshore of SE Alaska or the eastern GOA, although a few reports are 
available (e.g., Buckland et al., 1993; Hobbs and Lerczak, 1993; 
Straley et al., 1995; Calambokidis et al., 1997; MacLean and Koski, 
2005; Angliss and Outlaw, 2007).
    Table 2 outlines the species, their habitat and abundance in the 
project area, and the estimated exposure levels. Additional information 
regarding the status and distribution of the marine mammals in the area 
and how the densities were calculated was included in the notice of the 
proposed IHA (73 FR 45407, August 5, 2008) and may be found in L-DEO's 
application.

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                             Number of Indiv.      Percent of Estimated
           Species                 Habitat       Estimated Population     Avg. Density     Max. Density    Exposed to [gteqt]160   Population Exposed to
                                                                                                                    dB                 [gteqt]160 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
Odontocetes
------------------------------
Sperm whale (Physeter          Pelagic          24,000 \5\ (Regional)   0.00 \1\         0.00 \1\         49                      0.2
 macrocephalus)                                                         0.31 \2\         0.58 \2\
                                                                        4.04 \3\         6.06 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cuvier's beaked whale          Pelagic          20,000 \6\ (Regional)   0.00 \1\         0.00 \1\         35                      0.2
 (Ziphius cavirostris)                                                  2.76 \2\         3.70 \2\
                                                                        0.00 \3\         0.00 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baird's beaked whale           Pelagic          6,000 \7\ (Regional)    0.00 \1\         0.00 \1\         8                       0.1
 (Berardius bairdii)                                                    0.66 \2\         0.88 \2\
                                                                        0.00 \3\         0.00 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stejneger's beaked whale       Likely Pelagic   N.A.                    0.00 \1\         0.00 \1\         N.A.                    0
 (Mesoplodon stejnegeri)                                                0.00 \2\         0.00 \2\
                                                                        0.00 \3\         0.00 \0\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Beluga whale (Delphinapterus   Coastal & Ice    366 \8\ (Alaska)        0.00 \1\         0.00 \1\         0                       N.A.
 leucas)                        Edges                                   0.00 \2\         0.00 \2\
                                                                        0.00 \3\         0.00 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 52954]]

 
Pacific white-sided dolphin    Pelagic, Shelf,  26,880 \9\ (Alaska,     2.48 \1\         5.41 \1\         56                      0.2
 (Lagenorhynchus obliquidens)   Coastal          Stock)                 3.36 \2\         13.83 \2\
                                                                        0.00 \3\         0.00 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Killer whale (Orcinus orca)    Pelagic, Shelf,  1,975 \12\ (Alaska)     12.87 \1\        34.14 \1\        116                     5.9
                                Coastal                                 4.03 \2\         8.81 \2\
                                                                        0.00 \3\         0.00 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor Porpoise (Phocoena      Coastal          41,854 \15\ (Alaska,    23.26 \1\        47.27 \1\        346                     0.8
 phocoena)                                       Stock)                 17.85 \2\        24.21 \2\
                                                                        0.00 \3\         0.00 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dall's Porpoise (Phocoenoides  Pelagic & Shelf  83,400 \17\ (Alaska,    146.86 \1\       221.90 \1\       5,379                   0.7
 dalli)                                          Stock)                 662.63 \2\       877.32 \2\
                                                                        141.00 \3\       211.50 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mysticetes
------------------------------
Humpback whale (Megaptera      Coastal & Banks  >6,000 \22\ (Regional)  32.82 \1\        54.58 \1\        246                     4.1
 novaeangliae)                                                          11.89 \2\        24.37 \2\
                                                                        15.60 \3\        15.60 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Minke whale (Balaenoptera      Coastal & Shelf  9,000 \23\ (Regional)   1.20 \1\         4.87 \1\         9                       0.1
 acutorostrata)                                                         0.24 \2\         1.23 \2\
                                                                        0.00 \3\         0.00 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray whale (Eschrichtius       Coastal          18,813 \20\ (Regional,  0.00 \1\         0.00 \1\         0                       0
 robustus)                                       Stock)                 0.00 \2\         0.00 \2\
                                                                        0.00 \3\         0.00 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Fin whale (Balaenoptera        Pelagic          13,620-18,680 \22\      7.31 \1\         19.40 \1\        89                      0.7
 physalus)                                       (Regional)             11.08 \2\        20.25 \2\
                                                                        ...............  0.00 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blue whale (Balaenoptera       Pelagic, Shelf,  1,744 \11\ (Region)     0.00 \1\         0.00 \1\         0                       0
 musculus)                      Coastal                                 0.00 \2\         0.00 \2\
                                                                        0.00 \3\         0.00 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Pacific right whale      Coastal & Shelf  100-200 \19\            0.00 \1\         0.00 \1\         0                       0
 (Eubalaena japonica)                                                   0.00 \2\         0.00 \2\
                                                                        0.00 \3\         0.00 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pinnipeds
------------------------------
Northern fur seal              Pelagic, Breeds  721,935 \25\            0.00 \1\         0.00 \1\         0                       0
 (Callorhinus ursinus)          Coastally        (Regional, Stock)      0.00 \2\         0.00 \2\
                                                                        0.00 \3\         0.00 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steller sea lion (Eumetopias   Coastal          47,885 \26\ (E. Stock)  3.99 \1\         5.99 \1\         74 (62 E, 12 W)         0.1 E
 jubatus)                                       44,780 \27\ (W. Stock)  4.20 \2\         6.30 \2\                                 0.02 W
                                                                        0.00 \3\         0.00 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor seal (Phoca vitulina    Coastal          108,670 (Stock)         2.00 \1\         3.00 \1\         269                     0.2
 richardsi)                                                             20.28 \2\        30.42 \2\
                                                                        0.00 \3\         0.00 \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 2. The habitat, abundance, and conservation status of marine mammals inhabiting the proposed study area in the Gulf of Alaska. Regional abundance
  estimates are also given, usually for the Northeastern Pacific Ocean or the U.S. West Coast. Note: N.A. = Not available or not applicable.
\1\ Depths <100 m (330ft) (Densities of marine mammals during surveys in Southeast Alaska and the Gulf of Alaska calculated from data in Dahlheim and
  Towell (194), Dahlheim et al. (2000), Waite (2003), MacLean and Koski (2005), and Zerbini et al. (2006, 2007)).
\2\ Depths 100-1,000 m (330-3,300 ft)
\3\ Depths >1,000 m (3,300 ft)
\4\ Western GOA and eastern Aleutians (Zerbini et al., 2004).
\5\ Eastern temperate North pacific (Whitehead, 2002).
\6\ Eastern Tropical Pacific (Wade and Gerrodette, 1993).
\7\ Western North Pacific (Reeves and Leatherwood, 1994; Kasuya, 2002).
\8\ Cook Inlet stock (Rugh et al., 2005a).
\9\ GOA (Angliss and Outlaw, 2007).
\10\ North Pacific Ocean (Buckland et al., 1993).
\11\ California/Oregon/Washington (Carretta et al. 2007).
\12\ Minimum abundance in Alaskan waters, includes 1,339 resident and 636 transient (Angliss and Outlaw, 2007).
\13\ Eastern Tropical Pacific (Ford, 2002).

[[Page 52955]]

 
\14\ SE Alaska stock (Angliss and Outlaw, 2007).
\15\ GOA stock (Angliss and Outlaw 2007).
\16\ Western North Pacific Ocean (totals from Carretta et al., 2007 and Angliss and Outlaw, 2007).
\17\ Alaska stock (Angliss and Outlaw, 2007).
\18\ North Pacific Ocean and Bering Sea (Houk and Jefferson, 1999).
\19\ Eastern North Pacific (Wada, 1973).
\20\ Mean of 2000-2001 and 2001-2002 abundance estimates for eastern North Pacific (Angliss and Outlaw, 2007).
\21\ Western GOA and eastern Aleutians (Zerbini et al., 2006).
\22\ North Pacific Ocean (Carretta et al., 2007).
\23\ North Pacific Ocean (Wada, 1976).
\24\ Central waters of western Alaska and eastern and central Aleutian Islands (Angliss and Outlaw, 2007).
\25\ Abundance for Eastern Pacific Stock (Angliss and Outlaw, 2007).
\26\ Eastern U.S. Stock (Angliss and Outlaw, 2007).
\27\ Western U.S. Stock (Angliss and Outlaw, 2007).
\28\ Alaska statewide (Angliss and Outlaw, 2007).
\29\ Abundance estimate for SE Alaska stock (USFWS 2002 in Angliss and Outlaw, 2007).
\30\ Abundance estimate Southcentral Alaska (USFWS 2002 in Angliss and Outlaw, 2007).
\31\ SW Alaska stock (USFWS 2002 in Angliss and Outlaw, 2007).

Potential Effects on Marine Mammals

    The effects of sounds from airguns might include one or more of the 
following: tolerance, masking of natural sounds, behavioral 
disturbances, and at least in theory, temporary or permanent hearing 
impairment, or non-auditory physical or physiological effects 
(Richardson et al., 1995; Gordon et al., 2004; Nowacek et al., 2007; 
Southall et al., 2007). Permanent hearing impairment, in the unlikely 
event that it occurred, would constitute injury, but temporary 
threshold shift (TTS) is not an injury (Southall et al., 2007). With 
the possible exception of some cases of TTS in harbor seals, it is 
unlikely that the project would result in any cases of temporary 
impairment, or any significant non-auditory physical or physiological 
effects. Some behavioral disturbance is expected, but this would be 
localized and short-term. Also, behavioral disturbance is expected to 
be limited to relatively short distances.
    The notice of the proposed IHA (73 FR 45407, August 5, 2008) 
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 Appendix B of L-DEO's application.
    The notice of the proposed IHA also included a discussion of the 
potential effects of the multibeam echosounder (MBES) and the sub-
bottom profiler (SBP). 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 MBES or the SBP at levels at or above 
those likely to cause harassment. Further, NMFS believes that the brief 
exposure of cetaceans or pinnipeds to few signals from the multi-beam 
bathymetric sonar system is not likely to result in the harassment of 
marine mammals.

Estimated Take by Incidental Harassment

    The notice of the proposed IHA (73 FR 45407, August 5, 2008) 
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 L-DEO's 
application. A summary is included here.
    All anticipated ``takes by harassment'' authorized by this IHA are 
Level B harassment only, involving temporary changes in behavior. The 
mitigation measures are expected to minimize the possibility of 
injurious takes. Take calculations were based on maximum exposure 
estimates (based on maximum density estimates) vs. best estimates and 
are based on the 160-dB isopleth of a larger array of airguns. Given 
these considerations, the predicted number of marine mammals that might 
be exposed to sounds 160 dB may be somewhat overestimated.
    There are few systematic data on the numbers and distributions of 
marine mammals in SE Alaska and the GOA. Zerbini et al. (2003, 2006, 
2007) conducted vessel-based surveys in the northern and western GOA 
from the Kenai Peninsula to the central Aleutian Islands during July-
August 2001-2003. Killer whales were the principal target of the 
surveys, but the abundance and distribution of fin, humpback, and minke 
whales were also reported. Waite (2003) conducted vessel-based surveys 
in the northern and western GOA from Prince William Sound (PWS) to 
approximately 160[deg] W off Alaska Peninsula during 26 June- 15 July 
2003; cetaceans recorded included small odontocetes, beaked whales, and 
mysticetes. The eastern part of Zerbini et al. surveys and Waite's 
survey were confined to water <1,000 m deep, and most effort was in 
depths <100 m. Dahlheim et al. (2000) conducted aerial surveys of the 
nearshore waters from Bristol Bay to Dixon Entrance for harbor 
porpoises; SE Alaska was surveyed during 1-26 June 1993. Dahlheim and 
Towell (1994) conducted vessel-based surveys of Pacific white-sided 
dolphins in the inland waterways of SE Alaska during April-May, June or 
July, and September- early October of 1991-1993. In a report on a 
seismic cruise in SE Alaska from Dixon Entrance to Kodiak Island during 
August-September 2004, MacLean and Koski (2005) included density 
estimates of cetaceans and pinnipeds for each of three depth ranges 
(<100 m, 100-1,000 m, and >1,000 m) during non-seismic periods.
    Most surveys for pinnipeds in Alaskan waters have estimated the 
number of animals at haul-out sites, not in the water (e.g., Loughlin, 
1994; Sease et al., 2001; Withrow and Cesarone, 2002; Sease and York, 
2003). To our knowledge, the estimates of MacLean and Koski (2005) are 
the only in-water estimates of pinnipeds in the proposed survey area.
    The L-DEO survey will occur from September- October, 2008 in the 
Gulf of Alaska, , a location and time of year in which the species 
densities are likely similar or slightly different from those during 
the above-mentioned surveys in the Gulf of Alaska, but these surveys 
are the best available data at this time.
    Eight species of odontocete whales, five species of mysticete 
whale, and three species of pinnipeds are expected to be harassed 
during the seismic survey. Risso's dolphins and short-finned pilot 
whales are unlikely to occur in the study area and any sightings would 
be considered extralimital to their range. No take was authorized for 
either of these species. Stejneger's beaked whales, beluga whales, gray 
whales, and northern fur seals occur in the Gulf of Alaska, but 
generally occur in the study area in low numbers or at different times 
of the year. Although not expected in the area,

[[Page 52956]]

small numbers of take of Stejneger's beaked whales, gray whales, blue 
whales, and northern fur seals were authorized due to a lack of marine 
mammal survey data and uncertainty in the study area. No take of North 
Pacific right or beluga whales is expected or authorized due to their 
rare occurrence in the area and the special mitigation for these 
species of concern. Where stock size wasn't available, NMFS used the 
estimated abundance in Alaska or the region to determine the percentage 
of the population exposed to sound levels greater than or equal to 160 
dB. Since the take estimates authorized in this IHA are no more than 
5.9 percent of any affected cetacean species and no more than 0.2 
percent of any affected pinnipeds species found along or offshore of 
the Alaskan coast, NMFS believes that the estimated take numbers for 
these species and stocks are small relative to the relevant population 
of these affected species or stocks.
    Table 3 (see below) outlines the species, estimated stock 
population (minimum and best), and estimated percentage of the stock 
exposed to seismic impulses in the project area. Additional information 
regarding the status, abundance, and distribution of the marine mammals 
in the area and how the densities were calculated was included in Table 
2 (see above), the notice of the proposed IHA (73 FR 45407, August 5, 
2008) and may be found in L-DEO's application

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 notice of the 
proposed IHA (73 FR 45407, August 5, 2008). 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 sources are expected to be 
negligible.

Subsistence Activities

    The proposed project could potentially impact the availability of 
marine mammals for subsistence harvest in a very small area immediately 
around the Langseth, and for a very short time period during seismic 
activities. Considering the limited time and locations for the planned 
seismic surveys, most of which are well offshore, the proposed project 
is not expected to have any significant impacts to the availability of 
beluga whales, Steller sea lions, Pacific harbor seals, and sea otters. 
Also, seismic surveys can at times, cause changes in the catchability 
of fish.
    To avoid having an unmitigable adverse impact on subsistence uses 
of marine mammals, NMFS is required to implement mitigation measures to 
ensure that NSF and L-DEO's seismic activities do not have an 
unmitigable adverse impact on subsistence uses of marine mammals in the 
project area. L-DEO will minimize the potential to negatively impact 
the subsistence harvest by coordinating with local native communities 
and avoiding areas (to the maximum extent practicable) where 
subsistence collectors are hunting marine mammals and fishing. 
Additionally, L-DEO will consult with each village near the planned 
project area to identify and avoid areas of potential conflict. These 
consultations will include all marine subsistence activities (mammals 
and fisheries). Implementation of these measures ensures that there 
will not be significant social or economic impacts on the coastal 
inhabitants of the GOA and Southeast Alaska. NMFS has determined (based 
on the above stated reasons) that L-DEO's activities will not have an 
unmitigable adverse impact on the subsistence uses of the species 
hunted by Alaska Natives and a requirement to these effects will be 
addressed in the IHA.

Monitoring and Mitigation

    Mitigation and monitoring measures required to be implemented for 
the proposed seismic survey have been developed and refined during 
previous L-DEO seismic survey studies and associated environmental 
assessments (EAs), IHA applications, and IHAs. The mitigation and 
monitoring measures described herein represent a combination of the 
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.
    Required mitigation measures include: (1) speed or course 
alteration, provided that doing so will not compromise operational 
safety requirements; (2) power-down procedures; (3) shutdown 
procedures; (4) ramp-up procedures; (5) special procedures for 
situations and species of particular concern, e.g., avoidance of 
critical habitat around Steller sea lion rookeries and haul-outs (see 
``shut-down procedures'' and ``special procedures for situations and 
species of particular concern,'' below).

Vessel-based Visual Monitoring

    Vessel-based 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 shutdown of the airguns (i.e., 7 
minutes). When feasible, MMVOs will also make observations during 
daytime periods when the seismic system is not operating for comparison 
of animal abundance and behavior. Based on MMVO observations, airguns 
will be powered down, or if necessary, shut down completely (see 
below), when marine mammals are detected within or about to enter a 
designated safety radius corresponding to 180 dB (for cetaceans) and 
190 dB (for pinnipeds) isopleths. 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 isopleth in 
Table 1.
    During seismic operations in the Gulf of Alaska, at least three 
visual observers and one bioacoustician will be based aboard the 
Langseth. MMVOs will be appointed by L-DEO with NMFS concurrence. At 
least one MMVO, and when practical two, will monitor the safety radii 
for marine mammals during daytime operations and nighttime startups of 
the airguns. Use of two simultaneous MMVOs will increase the proportion 
of the animals present near the source vessel that are detected. 
MMVO(s) will be on duty in shifts of duration no longer than 4 hours. 
The vessel crew will also be instructed to assist in detecting marine 
mammals and implementing mitigation requirements (if practical). Before 
the start of the seismic survey the crew will be given additional 
instruction regarding how to do so.
    The Langseth is a suitable platform for marine mammal observations. 
When stationed on the observation platform, the eye level will be 
approximately 17.8 m (58.4 ft) above sea level, and the observer will 
have a good view around the entire vessel. During daytime, the MMVO(s) 
will scan the area around the vessel systematically with reticle 
binoculars (e.g., 7x50 Fujinon), Big-eye binoculars (25x150), and with 
the naked eye. During darkness, NVDs will be

[[Page 52957]]

available (ITT F500 Series Generation 3 binocular-image intensifier or 
equivalent). Laser rangefinding binoculars (Leica LRF 1200 laser 
rangefinder or equivalent) will be available to assist with distance 
estimation. Those are useful in training MMVOs to estimate distances 
visually, but are generally not useful in measuring distances to 
animals directly.

Passive Acoustic Monitoring

    PAM will take place to complement the visual monitoring program. 
Acoustic monitoring can be used in addition to visual observations to 
improve detection, identification, localization, and tracking of 
cetaceans. It is only useful when marine mammals call, but it can be 
effective either by day or by night and does not depend on good 
visibility. The acoustic monitoring will serve to alert visual 
observers when vocalizing cetaceans are detected. It will be monitored 
in real time so visual observers can be advised when cetaceans are 
detected. When bearings (primary and mirror-image) to calling 
cetacean(s) are determined, the bearings will be relayed to the visual 
observer to help him/her sight the calling animal(s).
    The PAM system consists of hardware (i.e., hydrophones) and 
software. The ``wet end'' of the system consists of a low-noise, towed 
hydrophone array that is connected to the vessel by a ``hairy'' faired 
cable. The array will be deployed from a winch located on the back 
deck. A deck cable will connect from the winch to the main computer lab 
where the acoustic station and signal condition and processing system 
will be located. Th lead-in from the hydrophone array is approximately 
400 m (1,312 ft) long, and the active part of the hydrophone is 
approximately 56 m (184 ft) long. The hydrophone array is typically 
towed at depths <20 m (65.6 ft).
    The towed hydrophone array will be monitored 24 hours per day while 
at the survey area during airgun operations and also during most 
periods when the Langseth is underway with the airguns not operating. 
One Marine Mammal Observer (MMO) and/or bioacoustician will monitor the 
acoustic detection system at any one time, by listening to the signals 
from two channels via headphones and/or speakers and watching the real 
time spectrographic display for frequency ranges produced by cetaceans. 
MMOs monitoring the acoustical data will be on shift for 1-6 hours. Of 
the three observers required on board, one will have primarily 
responsibility for PAM during the seismic survey. However, all MMOs are 
expected to rotate through the PAM position, although the most 
experienced with acoustics will be on PAM duty more frequently.
    When a vocalization is detected, the acoustic MMO will, if visual 
observations are in progress, contact the MMVO immediately to alert 
him/her to the presence of the vocalizing marine mammal(s) (if they 
have not already been seen), and to allow a power down or shutdown to 
be initiated, if required. The information regarding the call will be 
entered into a database. The data to be entered includes an acoustic 
encounter identification number, whether it was linked with a visual 
sighting, date, time when first and last heard and whenever any 
additional information was recorded, position and water depth when 
first detected, bearing if determinable, species or species group 
(e.g., unidentified dolphin, sperm whale), types and nature of sounds 
heard (e.g., clicks, continuous, sporadic, whistles, creaks, burst 
pulses, strength of signal, etc.), and any other notable information. 
The acoustic detection can also be recorded for further analysis.
    Speed or Course Alteration - If a marine mammal is detected outside 
the safety radius and, based on its position and the relative motion, 
is likely to enter the safety radius or exclusion zone (EZ), the 
vessel's speed and/or direct course may be changed. This would be done 
if practicable while minimizing the effect on th planned science 
objectives. The activities and movements of the marine mammal(s) 
(relative to the seismic vessel) will then be closely monitored to 
determine whether the animals is approaching the applicable EZ. If the 
animal appears likely to enter the EZ, further mitigative actions will 
be taken, i.e., either further course alterations or a power down or 
shut down of the airguns. Typically, during seismic operations, major 
course and speed adjustments are often impractical when towing long 
seismic streamers and large source arrays, thus alternative mitigation 
measures (see below) will need to be implemented.
    Power-down Procedures - A power-down involves reducing the number 
of operating airguns in use to minimize the EZ, so that marine mammals 
are no longer in or about to enter this zone. A power-down of the 
airgun array to a reduced number of operating airguns may also occur 
when the vessel is moving from one seismic line to another. During a 
power down for mitigation, one airgun will be operated. The continued 
operation of at least one airgun is intended to alert marine mammals to 
the presence of the seismic vessel in the area. In contrast, a shut 
down occurs when all airgun activity is suspended.
    If a marine mammal is detected outside the EZ but is likely to 
enter it, and if the vessel's speed and/or course cannot be changed to 
avoid the animal(s) entering the EZ, the airguns will be powered down 
to a single airgun before the animal is within the EZ. Likewise, if a 
mammal is already within the EZ when first detected, the airguns will 
be powered down immediately. During a power down of the airgun array, 
the 40-in\3\ airgun will be operated. If a marine mammal is detected 
within or near the smaller EZ around that single airgun (see Table 1 
above), all airguns will be shutdown (see next subsection).
    Following a power down, 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:
    (1) Is visually observed to have left the EZ; or
    (2) Has not been seen within the EZ for 15 minutes in the case of 
small odontocetes and pinnipeds; or
    (3) Has not been seen within the EZ for 30 minutes in the case of 
mysticetes and large odontocetes, including sperm, pygmy sperm, dwarf 
sperm, and beaked whales; or
    During airgun operations following a power-down (or shut down) and 
subsequent animal departure as above, the airgun array will resume 
operations following ramp-up procedures described below.
    Shutdown Procedures - The operating airgun(s) will be shutdown if a 
marine mammal is detected within or approaching the EZ for the then-
operating single 40 in\3\ airgun while the airgun array is at full 
volume or during a power down. Airgun activity will not resume until 
the marine mammal has cleared the EZ or until the MMVO is confident 
that the animal has left the vicinity of the vessel. Criteria for 
judging that the animal has cleared the EZ will be as described in the 
preceding subsection.
    Ramp-up Procedures - A ramp-up procedure will be followed when the 
airgun array begins operating after more than 7 minutes without airgun 
operations or when a power down has exceeded 7 minutes. This period is 
based on the modeled 180-dB radius for the 36-airgun array (see Table 
1) in relation to the planned speed of the Langseth while shooting. 
Similar periods (approximately 8-10 minutes) were used during previous 
L-DEO surveys.
    Ramp-up will begin with the smallest airgun in the array (40 
in\3\). Airguns will be added in a sequence such that the source level 
of the array will increase in

[[Page 52958]]

steps not exceeding 6 dB per 5-minute period over a total duration of 
approximately 20-25 minutes. During ramp-up, the MMVOs will monitor the 
EZ, and if marine mammals are sighted, a course/speed change, power 
down, or shutdown will be implemented as though the full array were 
operational.
    If the complete EZ has not been visible for at least 30 min prior 
to the start of operations in either daylight or nighttime, ramp up 
will not commence unless at least one airgun (40 in\3\ or similar) has 
been operating during the interruption of seismic survey operations. 
Given these provisions, it is likely that the airgun array will not be 
ramped up from a complete shut down at night or in thick fog, because 
the other part of the EZ for that array will not be visible during 
those conditions. If one airgun has operated during a power down 
period, ramp up to full power will be permissible at night or in poor 
visibility, on the assumption that marine mammals will be alerted to 
the approaching seismic vessel by the sounds from the single airgun and 
have the opportunity to move away. Ramp up of the airguns will not be 
initiated if a marine mammal is isghted within or near the applicable 
EZ during the day or close to the vessel at night.
Special Procedures for Situations and Species of Concern
    Several species of concern could occur in the study area. To the 
maximum extent practicable, special mitigation procedures will be used 
for those species, as follows:
    (1) Critical habitat around Steller sea lion rookeries and haul-
outs will be avoided;
    (2) The airguns will be shut down if a North Pacific right whale is 
sighted at any distance from the vessel;
    (3) The airguns will be shut down if a beluga whale is sighted at 
any distance from the vessel in or near Yakutat Bay;
    (4) Concentrations of humpback whales, fin whales, and sea otters 
will be avoided;
    (5) The seismic vessel will avoid areas where subsistence fishers 
are hunting for marine mammals and/or fishing; and
    (6) Because the sensitivity of beaked whales, approach to slopes 
will be minimized, if possible. There are no submarine canyons in or 
near the study area, and only a limited amount of airgun operations is 
planned over slope during the proposed survey (Figure 1 of L-DEO's 
application).

MMVO Data and Documentation

    MMVOs will record data to estimate the numbers of marine mammals 
exposed to various received sound levels and to document any apparent 
disturbance reactions or lack thereof. Data will be used to estimate 
the numbers of mammals potentially ``taken'' by harassment. They will 
also provide information needed to order a power-down or shutdown of 
airguns when marine mammals are within or near the relevant safety 
radius. When a sighting is made, the following information about the 
sighting will be recorded:
    (1) Species, group size, age/size/sex categories (if determinable), 
behavior when first sighted and after initial sighting, heading (if 
consistent), bearing and distance from seismic vessel, sighting cue, 
apparent reaction to the airguns or vessel (e.g., none, avoidance, 
approach, paralleling, etc. and including responses to ramp-up), and 
behavioral pace.
    (2) Time, location, heading, speed, activity of the vessel 
(including number of airguns operating and whether in state or ramp-up, 
power-down, or full power), sea state, visibility, cloud cover, and sun 
glare.
    The data listed under (2) will also be recorded at the start and 
end of each observation watch and during a watch, whenever there is a 
change in one or more of the variables.
    All observations, as well as information regarding airgun power 
down and shutdown, will be recorded in a standardized format. Data will 
be entered into a custom electronic database. The accuracy of data will 
be verified by computerized data validity checks as the data are 
entered and by subsequent manual checking of the database. Preliminary 
reports will be prepared during the field program and summaries 
forwarded to the operating institution's shore facility and to NSF 
weekly or more frequently. MMVO observations will provide the following 
information:
    (1) The basis for decisions about powering down or shutting down 
airgun arrays.
    (2) Information needed to estimate the number of marine mammals 
potentially ``taken by harassment.'' These data will be reported to 
NMFS per terms of MMPA authorizations or regulations.
    (3) Data on the occurrence, distribution, and activities of marine 
mammals in the area where the seismic study is conducted.
    (4) Data on the behavior and movement patterns of marine mammals 
seen at times with and without seismic activity.

Reporting

    A report will be submitted to NMFS within 90 days after the end of 
the cruise. The report will describe the operations that were conducted 
and sightings of marine mammals near the operations. T