Marine Mammals; Incidental Take During Specified Activities; Proposed Incidental Harassment Authorization, 59211-59220 [2012-23749]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 77, Number 187 (Wednesday, September 26, 2012)]
[Notices]
[Pages 59211-59220]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-23749]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

[FWS-R8-FHC-2012-N194; FRES48010810420-L5-FY12]


Marine Mammals; Incidental Take During Specified Activities; 
Proposed Incidental Harassment Authorization

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of receipt of application; request for comments.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), have 
received an application from Pacific Gas and Electric Company (PG&E) 
for authorization under the Marine Mammal Protection Act of 1972 (MMPA) 
to take small numbers of southern sea otters (Enhydra lutris nereis) by 
harassment, as those terms are defined in the statute and the Service 
implementing regulations, incidental to a marine geophysical survey. In 
accordance with provisions of the MMPA, we request comments on our 
proposed authorization for the applicant to incidentally take, by 
harassment, small numbers of southern sea otters for a period of 2.5 
months beginning on October 15, 2012, and ending December 31, 2012. We 
anticipate no take by injury or death and include none in this proposed 
authorization, which would be for ``take by harassment'' only.

DATES: Comments and information must be received by October 26, 2012.

ADDRESSES: You may submit comments by any one of the following methods:

[[Page 59212]]

    1. By U.S. mail or hand-delivery to: Diane Noda, Field Supervisor, 
Ventura Fish and Wildlife Office, 2493 Portola Road, Suite B, Ventura, 
CA 93003.
    2. By fax to: 805-644-3958, attention to Diane Noda, Field 
Supervisor.
    3. By electronic mail (email) to: R8_SSO-IHA_Comment@FWS.gov.
    Please include your name and return address in your message.

FOR FURTHER INFORMATION CONTACT: To request copies of the application, 
the list of references used in this notice, and other supporting 
materials, contact Lilian Carswell at the address in ADDRESSES, or by 
email at Lilian_Carswell@fws.gov.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA, as amended (16 U.S.C. 
1371 (a)(5)(A) and (D)), authorize the Secretary of the Interior to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region, provided that we make certain findings and either 
issue regulations or, if the taking is limited to harassment, provide a 
notice of a proposed authorization to the public for review and 
comment.
    We may grant authorization to incidentally take marine mammals if 
we find that the taking will have a negligible impact on the species or 
stock(s), and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses. As part 
of the authorization process, we prescribe permissible methods of 
taking and other means of affecting the least practicable impact on the 
species or stock and its habitat, and requirements pertaining to the 
monitoring and reporting of such takings.
    The term ``take,'' as defined by the MMPA, means to harass, hunt, 
capture, or kill, or to attempt to harass, hunt, capture, or kill, any 
marine mammal. ``Harassment,'' as defined by the MMPA, means ``any act 
of pursuit, torment, or annoyance which (i) has the potential to injure 
a marine mammal or marine mammal stock in the wild [the MMPA calls this 
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 [the MMPA calls 
this Level B harassment].''
    The terms ``small numbers,'' ``negligible impact,'' and 
``unmitigable adverse impact'' are defined in 50 CFR 18.27, the 
Service's regulations governing take of small numbers of marine mammals 
incidental to specified activities. ``Small numbers'' is defined as ``a 
portion of a marine mammal species or stock whose taking would have a 
negligible impact on that species or stock.'' ``Negligible impact'' is 
defined 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.'' ``Unmitigable adverse impact'' is defined 
as ``an impact resulting from the specified activity (1) that is likely 
to reduce the availability of the species to a level insufficient for a 
harvest to meet subsistence needs by (i) causing the marine mammals to 
abandon or avoid hunting areas, (ii) directly displacing subsistence 
users, or (iii) placing physical barriers between the marine mammals 
and the subsistence hunters; and (2) that cannot be sufficiently 
mitigated by other measures to increase the availability of marine 
mammals to allow subsistence needs to be met.'' The subsistence 
provision does not apply to the southern sea otters.
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which U.S. citizens can apply for an authorization to incidentally 
take small numbers of marine mammals where the take will be limited to 
harassment. Section 101(a)(5)(D)(iii) establishes a 45-day time limit 
for Service 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, we must either issue or deny issuance of the 
authorization. We refer to these authorizations as Incidental 
Harassment Authorizations (IHAs).

Summary of Request

    On August 31, 2012, we received a revised request from PG&E 
(applicant) for MMPA authorization to ``take by harassment'' southern 
sea otters (Enhydra lutris nereis) incidental to a High Energy Seismic 
Survey (HESS) in the vicinity of the Diablo Canyon Power Plant (DCPP) 
and known offshore fault zones near DCPP in San Luis Obispo County, 
California. An initial request was received June 28, 2012. The project 
is a collaborative effort between PG&E and the Lamont-Doherty Earth 
Observatory (LDEO), a part of Columbia University. The project would 
consist of deploying a seismic sound source offshore and receivers at 
both onshore and offshore locations to generate data that could be used 
to improve imaging of major geologic structures and fault zones in the 
vicinity of the DCPP. Project activities are necessary to comply with 
the requirements established by California State Assembly Bill 1632 and 
directives of the California Public Utilities Commission to determine 
whether there is any relationship between the known faults and to 
enhance knowledge of offshore faults that are located in proximity to 
the Central California Coast and DCPP. Estimating the limits of future 
earthquake ruptures is particularly important in light of the close 
proximity of the Hosgri Fault Zone to DCPP, one of California's major 
nuclear power plants.
    The applicant would conduct the geophysical survey with a seismic 
research vessel (R/V Marcus G. Langseth), owned by the National Science 
Foundation (NSF), and support/monitoring vessels, within two partially 
overlapping survey box areas located between Estero Bay and the Santa 
Maria River mouth (survey box area 3 was initially proposed but has 
been removed from the project, and survey box area 1 was initially 
proposed for 2012 but is now proposed to be conducted in 2013; because 
IHAs are valid for no more than 1 year, only survey box areas 2 and 4 
are considered under this authorization). Should the applicant request 
incidental harassment authorization for survey box area 1 in 2013, the 
Service will reanalyze the small number and negligible impact 
determinations, which would include evaluation of the information 
gained through the monitoring and reporting requirements proposed in 
this IHA, and make a new finding at that time. The survey boxes would 
consist of multiple parallel transect lines spaced approximately 200 
meters (m) (656 feet (ft)) apart for survey box area 2 and 
approximately 300 m (984 ft) apart for survey box 4. The average line 
lengths and transit times for survey box areas 2 and 4 are given in 
Table 1.

[[Page 59213]]



                           Table 1--Geophysical Survey Box Line Lengths and Durations
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                                                                                                  Total time for
                                                                   Line transit    Average line     one survey
              Survey box                   Average line length     time  (hours)    change time       circuit
                                                                                      (hours)         (hours)
----------------------------------------------------------------------------------------------------------------
2.....................................  49.09 km (30.5 mi)......            5.89            1.58           14.94
4.....................................  11.57 km (7.19 mi)......            1.39            2               6.78
----------------------------------------------------------------------------------------------------------------

    The geophysical survey vessel would tow a series of sound-
generating air guns and sound-recording hydrophones along pre-
determined shore-parallel and shore-perpendicular transects to conduct 
deep seismic reflection profiling of major geologic structures and 
fault zones in the vicinity of DCPP. The air gun array would be towed 
at a depth of 9 m (30 ft) and consist of 18 air guns with a total air 
discharge volume of approximately 3,300 inch (in)\3\. The sound would 
be generated by the discharge of the air guns once every 15-20 seconds, 
approximately every 37.5 m (123 ft), assuming a vessel speed of 8.3 
kilometers (km)/hour (hr) (4.5 knots).
    The nearshore actions would include the placement of 12 seafloor 
geophones (e.g., Fairfield Z700 nodal units) in nearshore water areas 
(to approximately the 70 m [300 ft] isobath).The proposed deep (10 to 
15 km or 6 to 9 miles [mi]) below ground survey High Energy Seismic 
Survey (HESS) (energy > 2 kilo joule) would complement previously 
completed shallow (<1 km [<0.6 mi] below ground surface) low energy (<2 
kilo joule) 3D seismic reflection surveys.
    A detailed description of the proposed action is contained in the 
Draft Environmental Assessment (Draft EA) for Marine Geophysical 
Surveys by the R/V Marcus G. Langseth for the Central Coastal 
California Seismic Imaging (Padre Associates, Inc. 2012), and the 
revised Incidental Harassment Authorization (IHA) Application (Padre 
Associates, Inc. 2012) submitted to the National Marine Fisheries 
Service (NMFS) and the Service on August 31, 2012.

Description of the Activity

    Marine Geophysical Surveys by the R/V Marcus G. Langseth for the 
Central Coastal California Seismic Imaging Project (project), San Luis 
Obispo County, California.

a. Timing of Activities

    The surveys are proposed to be conducted from October 15 through 
December 31, 2012, to avoid the period of highest marine mammal and 
fish migration activity and to accommodate nesting bird constraints. 
Mobilization could begin as early as October 15, but sound source 
verification procedures and active air gun surveys would start no 
earlier than November 1. The surveys would occur 24 hours per day, 7 
days per week. The project duration would be approximately 49 days, 
with the seismic survey comprising approximately 23 of those days, and 
the remaining days occupied in project preparation, transit, and 
anticipated weather and/or ship maintenance delays.
    The proposed survey includes a total survey line length of 3,565.8 
km (2,215.7 mi), of which 46.4 km (28.8 mi) of survey transect lines 
would be traveled in areas shallower than the 40-m (131-ft) contour. 
The 40-m (131-ft) contour is the depth within which more than 95 
percent of southern sea otter dives occur (Tinker et al. 2006a). The 
survey vessel would spend approximately 5.5 hours of the 23-day project 
(survey portion) schedule in areas shallower than the 40-m (131-ft) 
contour. However, because sound travels outward from the air guns, 
areas within the 40-m (131-ft) contour would at times be ensonified to 
levels of 160 decibels relative to one microPascal (dB re 1 [mu]Pa) or 
greater even when the vessel is outside this contour. Portions of these 
areas would be ensonified to levels of 160 dB re 1 [mu]Pa or greater 
whenever the vessel was within 6.2 km (3.9 mi) of the 40-m (131-ft) 
contour, totaling approximately 184 hours (115 and 69 hours for survey 
box areas 2 and 4, respectively) over the duration of the survey. A 
circular area surrounding the airguns with a radius of 1.0 km (0.63 mi) 
would be ensonified to levels of 180 dB re 1 [mu]Pa or greater. This 
area would be designated an ``exclusion zone'' (see Mitigation Measures 
below).

b. Geographic Location of Activities

    The 3D seismic survey track lines encompass an area of 
approximately 740.5 km\2\ (285.9 mi\2\), including all survey box 
overlapping areas (the actual survey footprint is approximately 631 
km\2\ [244 mi\2\]). The offshore (vessel) survey would be conducted 
between Cambria and the Santa Maria River mouth in both Federal and 
State waters, in water depths ranging from 0 to over 400 m (1,300 ft). 
The Point Buchon Marine Protected Area (MPA) lies within portions of 
the survey area, and the Cambria and White Rock Marine Conservation 
Areas (MCA) are located within areas of survey vessel turns. The 
Monterey Bay National Marine Sanctuary (MBNMS), a federally protected 
marine sanctuary that extends northward from Cambria to Marin County, 
is located to the north of the project area.

Description of Habitat and Marine Mammals Affected by the Activity

    The project would be conducted in rocky-bottom and sandy-bottom 
marine habitat off the coast of central California in water depths 
ranging from 0-400 m (1,300 ft). Sea otter habitat is typically defined 
by the 40-m (131-ft) isobath (Laidre et al. 2001). Individually, survey 
box areas 2 and 4 would ensonify 8.3 and 7.4 percent of the southern 
sea otter range, respectively, to levels of 160 dB re 1 [mu]Pa or 
greater. Because these survey box areas overlap, the total proportion 
of the range affected is less than the sum of two survey box areas 
viewed independently. In total, approximately 11.5 percent of the 
habitat within which the mainland population of the southern sea otter 
currently occurs would be ensonified to levels of 160 dB re 1 [mu]Pa or 
greater over the duration of the survey. This habitat is located in the 
southern half of the southern sea otter's range.
    The southern sea otter is the only marine mammal under the 
jurisdiction of the Service that would be affected by the proposed 
project. Among the largest members of the family Mustelidae but the 
smallest of marine mammals, southern sea otters exhibit limited sexual 
dimorphism (males are larger than females) and can attain weights and 
lengths up to 40 kg (88 lbs) and 140 cm (55 in), respectively. They 
have a typical life span of 11-15 years (Riedman and Estes 1990). 
Unlike most other marine mammals, sea otters have little subcutaneous 
fat. They depend on their clean, dense, water-resistant fur for 
insulation against the cold and maintain a high level of internal heat 
production to compensate for their lack of blubber. Consequently, their 
energetic

[[Page 59214]]

requirements are high, and they consume an amount of food equivalent to 
approximately 23 to 33 percent of their body weight per day (Riedman 
and Estes 1990). Contamination of the fur by oily substances can 
destroy its insulating properties and lead to hypothermia and death. 
The loss of the insulating properties of the fur exacerbates the 
adverse effects of oil spills on southern sea otters and is one of the 
reasons that increased tanker traffic and the potential for oil spills 
was considered in the listing of the species.
    Southern sea otters forage in both rocky and soft-sediment 
communities in water depths generally 25 m (82 ft) or less, although 
individuals occasionally move into deeper water. Individual animals 
tend to specialize on a subset of the overall population diet. Dive 
depth and dive pattern vary by sex (males tend to make deep dives more 
frequently than females), geographic location, and diet specialization 
(Tinker et al. 2006a, Tinker et al. 2007). Sea otters occasionally make 
dives of up to 328 ft (100 m), but the vast majority of feeding dives 
(more than 95 percent) occur in waters less than 131 ft (40 m) in depth 
(Tinker et al. 2006a). Therefore, sea otter habitat is typically 
defined by the 40-m (131-ft) isobath (Laidre et al. 2001).
    The annual patterns that characterize the movements of southern sea 
otters along the coast are complicated and vary between males and 
females. Their home ranges tend to consist of several heavily used 
areas with travel corridors between them. Animals often remain in an 
area for a long period of time and then suddenly move long distances. 
These movements can occur at any time of the year (Riedman and Estes 
1990). Sub-adult males have the largest home ranges, followed by adult 
males, sub-adult females, and adult females (Tinker et al. 2006a). 
Compared to males, most females are more sedentary, although females 
also occasionally travel long distances. Juvenile males move further 
from natal groups than do juvenile females. Aggressive behavior 
exhibited towards the juvenile males by breeding males may be partially 
responsible for their more extensive travels (Ralls et al. 1996). 
Jameson (1998) noted that adult male sea otters are territorial and 
exclude juvenile and subordinate males from their territories. However, 
females move freely across these territories. Generally, southern sea 
otters occupy territories on a seasonal basis. Many males migrate to 
the range peripheries during the winter and early spring, apparently to 
take advantage of more abundant prey resources, but then return to the 
range center during the period when most breeding occurs (June to 
November) in search of estrous females (Jameson 1989; Tinker et al. 
2006a; Tinker et al. 2006b). A peak period of pupping occurs from 
January to March, and a secondary pupping season occurs in late summer 
and early fall (Riedman et al. 1994). Parental care is provided solely 
by the female.
Status and Distribution of Affected Species
    Southern sea otters are listed as threatened under the Endangered 
Species Act of 1973, as amended (ESA), and because of their threatened 
status are automatically considered ``depleted'' under the MMPA. A 
final revised recovery plan for the southern sea otter was published in 
2003 (68 FR 16305). The State of California also recognizes the 
southern sea otter as a fully protected mammal (Fish and Game Code 
section 4700) and as a protected marine mammal (Fish and Game Code 
section 4500).
    All members of the southern sea otter population are descendants of 
a small group that survived the fur trade near Big Sur, California. 
Historically ranging from at least as far north as Oregon (Valentine et 
al. 2008) to Punta Abreojos, Baja California, Mexico, in the south, 
southern sea otters currently occur in only two areas of California. 
The mainland population ranges from San Mateo County in the north to 
Santa Barbara County in the south and numbers approximately 2,800 
animals (the 3-year running average based on the spring 2012 census is 
2,792) (https://www.werc.usgs.gov/Project.aspx?ProjectID=91). A small 
translocated population occurs at San Nicolas Island, numbering 
approximately 50 independent animals as of 2012 (USGS unpublished 
data). Data from recent years suggest that southern sea otter 
population numbers overall are stable or slightly declining.
    Southern sea otter abundance varies considerably across the range, 
with the highest densities occurring in the center part of the range 
(Monterey peninsula to Estero Bay), where they have been present for 
the longest. Densities tend to be most stable from year to year in 
rocky, kelp-dominated areas that are primarily occupied by females, 
dependent pups, and territorial males. In contrast, sandy and soft-
bottom habitats (in particular Monterey Bay, Estero Bay, and Pismo 
Beach to Pt. Sal) tend to be occupied by males and sub-adult animals of 
both sexes (but rarely by adult females and pups) and are more variable 
in abundance from year to year. This variation is apparently driven in 
part by the long-distance movements and seasonal redistribution of 
males (Tinker et al. 2006b). The variability of counts at the south end 
of the range is also related to the seasonal movements of males 
migrating to the range peripheries during the winter and early spring 
(Tinker et al. 2006a, Tinker et al. 2006b).
    Standardized range-wide counts of southern sea otters were 
initiated in 1982. Census and distribution data are available from the 
U.S. Geological Survey Western Ecological Research Center at https://www.werc.usgs.gov/ProjectSubWebPage.aspx?SubWebPageID=4&ProjectID=91. 
These data include various density estimates delineated by polygons 
along the central California coast from shore to the 30-m (98-ft) depth 
contour and between the 30-m (98-ft) and 60-m (197-ft) depth contours. 
Based on these density estimates, Padre Associates calculated average 
sea otter densities for survey box areas 2 and 4 and the associated 160 
dB re 1 [mu]Pa exposure areas that comprise the project footprint: 1.07 
and 1.7 sea otters/km\2\ (2.77 and 4.4 sea otters/mi\2\), respectively.

Potential Impacts of the Proposed Seismic Survey on Sea Otters

Disturbance Reactions
    Little is known regarding the effects of sound on sea otters. Sea 
otters have not been reported as being particularly sensitive to sound 
disturbance, especially in comparison to other marine mammals. For 
instance, Riedman (1983, 1984) observed the behavior of sea otters 
along the California coast during single, 100-in\3\ air gun pulses and 
pulses from a 4,089-in\3\ air gun array. The air gun array produced 
low-frequency (5-500-Hertz [Hz]) sounds at 230 dB re 1 [mu]Pa at 1 m. 
No disturbance reactions were evident when the air gun array was as 
close as 0.9 km (0.5 mi), and the sea otters did not respond noticeably 
to the single air gun. The proposed seismic survey air gun array has an 
air discharge volume of approximately 3,300 in\3\, a dominant frequency 
of 0-188 Hz, and a source output (downward) of 252 dB re 1 [mu]Pa at 1 
m.
    Underwater sounds are not likely to affect sea otters at the 
surface, due to the pressure release effect. Thus, the susceptibility 
of sea otters to disturbance from underwater sounds is probably 
restricted to behaviors during which the head is submerged, such as 
during foraging dives and underwater swimming and, intermittently, 
during grooming bouts. Yeates et al. (2007) reported the following mean 
percent activity categories for six adult male

[[Page 59215]]

California sea otters: Feeding (36.3), resting (40.2), swimming (8.5), 
grooming (9.1), and other (7.3). In a study with a much larger sample 
size, Tinker et al. (2008) reported that central California sea otters 
spent approximately 40 percent of their time foraging. Because 
underwater behaviors constitute less than half of the total activity 
budget of southern sea otters along the central California coast, their 
exposure to underwater sounds is limited. Nevertheless, the disruption 
of underwater behaviors may result in the disruption of the entire 
activity budget of an exposed individual and, potentially, in the 
disturbance of associated individuals. In the case of the proposed 
seismic survey, which consists of multiple parallel closely spaced 
transect lines, with a time for one complete circuit of 14.94 hours 
(survey box area 2) or 6.78 hours (survey box area 4), it is virtually 
certain that any sea otter engaging in surface behaviors during one 
pass of the vessel would be engaging in underwater behaviors during a 
subsequent pass of the vessel. Therefore, all sea otters that remained 
in the area would ultimately be exposed to underwater sound associated 
with the seismic survey.
    Observed sea otter responses to disturbance are highly variable, 
probably reflecting the level of noise and activity to which they have 
been exposed and become acclimated over time and the particular 
location and social or behavioral state of that individual (G. Bentall, 
Monterey Bay Aquarium Sea Otter Research and Conservation Program, 
pers. comm.). Reactions to anthropogenic noise can be manifested as 
visible startle responses, flight responses (flushing into water from 
haulouts or ``splash-down'' alarm behavior in surface-resting rafts), 
changes in moving direction and/or speed, changes in or cessation of 
certain behaviors (such as grooming, socializing, or feeding), or 
avoidance of areas where noise sources are located.
    The biological significance of these behavioral disturbances is 
difficult to predict, especially if the detected disturbances appear 
minor. However, the consequences of behavioral modification would be 
expected to be biologically significant if the change affected growth, 
survival, or reproduction. Potentially significant behavioral 
modifications include:

 Disturbance of resting sea otters
 Marked disruption of foraging behaviors
 Separation of mothers from pups
 Disruption of spatial and social patterns (sexual segregation 
and male territoriality)

    Currently, NMFS uses 160 dB re 1 [mu]Pa at received level for 
impulse noises (such as air gun pulses) as the onset of behavioral 
harassment (Level B harassment) for all marine mammals that are under 
its jurisdiction, and 180 dB re 1 [mu]Pa at received level as the 
threshold for potential injury or permanent physiological damage (Level 
A harassment) for cetaceans (70 FR 1871, January 11, 2005). In the 
absence of data on which to base thresholds specific to sea otters, we 
utilize the 160 dB re 1 [mu]Pa and 180 dB re 1 [mu]Pa thresholds for 
Level B and Level A harassment of sea otters. Based on the 160 dB re 1 
[mu]Pa exposure area for survey box areas 2 and 4 and the average 
densities of sea otters in these areas, we estimate that approximately 
352 sea otters will be exposed to underwater sound levels of 160 dB re 
1 [mu]Pa or greater (Table 2). Note that because survey box areas 2 and 
4 overlap, the total number of sea otters expected to be exposed to 
this level of sound is less than the sum of the numbers of sea otters 
in the 160 dB re 1 [mu]Pa exposure areas for survey box areas 2 and 4. 
In the overlapping area, sea otters will be subject to sound exposures 
associated with both survey box areas. Because limited evidence 
suggests that sea otters are less suceptible to acoustic disturbance 
than other marine mammals, these thresholds may be overly conservative. 
If, during implementation of the project, sea otters appeared to be 
undisturbed by sound to the extent that the exclusion zone (see 
Mitigation Measures below) could not be successfully kept clear of sea 
otters, the applicant would have the option under the IHA to request 
that the Service approve a reduction of the exclusion zone radius. We 
would review the request and notify the applicant of our determination.

  Table 2--Estimated Number of Sea Otters Exposed to Underwater Sound Levels of 160 dB re 1 [mu] Pa or Greater
----------------------------------------------------------------------------------------------------------------
                                          Portion of 160 dB
                                        exposure area (km\2\)    Number of sea otters/   Number of sea otters in
              Survey box                 affecting sea otter             km\2\             160 dB exposure area
                                              population
----------------------------------------------------------------------------------------------------------------
2....................................                      245                     1.07                      261
4....................................                      155                     1.70                      263
2 and 4 merged.......................                      288                     1.22                      352
----------------------------------------------------------------------------------------------------------------

Hearing Impairment and Other Physical Effects
    Exposure to very strong sounds could affect southern sea otters 
physically in a number of ways. These include temporary threshold shift 
(TTS), which is short-term hearing impairment, and permanent threshold 
shift (PTS), which is permanent hearing loss. Non-auditory physical 
effects may also occur in southern sea otters exposed to strong 
underwater pulsed sound. Non-auditory physiological effects or injuries 
that may theoretically occur in mammals close to a strong sound source 
include stress, neurological effects, and other types of organ or 
tissue damage. However, there is no definitive evidence that any of 
these effects occur in sea otters, even those in close proximity to 
large arrays of air guns. It is unlikely that any effects of these 
types would occur during the present project given the brief duration 
of exposure of any given sea otter and the planned monitoring and 
mitigation measures. The following subsections discuss in more detail 
the possibilities of TTS, PTS, and non-auditory physical effects.
Temporary Threshold Shift (TTS)
    TTS is the mildest form of hearing impairment that can occur during 
exposure to a strong sound (Kryter 1985). While an animal is 
experiencing TTS, the hearing threshold rises and a sound must be 
stronger in order to be heard. It is a temporary phenomenon, and 
(especially when mild) is not considered physical damage or ``injury'' 
(Southall et al. 2007). Rather, the onset of TTS is an indicator that, 
if the animal is exposed to higher levels of that sound, physical 
damage is ultimately a possibility.
    The magnitude of TTS depends on the level and duration of noise 
exposure and, to some degree, on frequency, among other considerations 
(Kryter 1985; Richardson et al. 1995; Southall et

[[Page 59216]]

al. 2007). For sound exposures at or somewhat above the TTS threshold, 
hearing sensitivity recovers rapidly after exposure to the noise ends. 
In terrestrial mammals, TTS can last from minutes or hours to days. 
Only limited data have been obtained on sound levels and durations 
necessary to elicit mild TTS in marine mammals, and none of the 
published data concern TTS elicited by exposure to multiple pulses of 
sound during operational seismic surveys (Southall et al. 2007).
Permanent Threshold Shift (PTS)
    When PTS occurs, there is physical damage to the sound receptors in 
the ear. In severe cases, there can be total or partial deafness. In 
other cases, the animal has an impaired ability to hear sounds in 
specific frequency ranges (Kryter 1985). There is no specific evidence 
that exposure to pulses from air guns can cause PTS in any marine 
mammal, even with large arrays of air guns. However, given the 
possibility that mammals close to an air gun array might incur at least 
mild TTS in the absence of appropriate mitigation measures, there has 
been further speculation about the possibility that some individuals in 
very close proximity to air guns might incur PTS (e.g., Richardson et 
al. 1995; Gedamke et al. 2008). Single or occasional occurrences of 
mild TTS are not indicative of permanent auditory damage, but repeated 
or (in some cases) single exposures to a level well above that causing 
TTS might elicit PTS.
Vessel Collision Effects
    Boat strikes are a relatively low but persistent source of sea 
otter mortality. During the 2006-2010 period, 11 sea otters were 
suspected to have been struck by boats (USGS and CDFG unpub. data). 
However, vessel strikes involving sea otters appear primarily to 
involve small, fast boats, and most collision reports have come from 
small vessels (NMFS 2003; NMFS 2006). Because sea otters spend a 
considerable portion of their time at the surface of the water, they 
are typically visually aware of approaching boats and are able to move 
away if the vessel is not traveling too quickly. The noise of 
approaching boats provides an additional warning. Because the R/V 
Marcus G. Langseth and associated scout boats would be traveling 
relatively slowly (4.5 knots), it is unlikely that sea otters would 
suffer injury or death from a vessel collision.

Potential Impacts on Habitat

    The proposed seismic survey would not result in any known impacts 
on the habitats used by southern sea otters or the food sources they 
exploit. The main impact of the project would be temporarily elevated 
noise levels. Although approximately 11.5 percent of the mainland 
southern sea otter range would eventually be ensonified to sound levels 
of 160 dB re 1 [mu]Pa or greater by the time the survey was completed, 
only one circular area with a radius of approximately 6.2 km (3.9 mi) 
would be ensonified to these levels or greater at any one time.
    Preliminary biological surveys have been completed for the areas 
where marine geophone lines are proposed to be placed to ensure they 
are routed along corridors that minimize contact with rock substrates, 
kelp canopy areas, and seagrass beds. In areas where such habitats are 
unavoidable due to their contiguous distribution along the coastline, 
the placement and recovery of the small geophone units in potentially 
sensitive areas would be done by divers/remotely operated vehicles 
(ROVs) deployed from small vessels in such a way as to minimize any 
potential effects and to ensure that no sea otter habitat is 
permanently altered. All deployment and recovery operations would be 
conducted during daylight hours and monitored by an onboard Protected 
Species Observer (PSO).

Potential Impacts on Subsistence Needs

    The subsistence provision of the MMPA does not apply to southern 
sea otters.

Mitigation Measures

    Efforts were made during the initial project planning phase to 
identify the minimum energy source level needed for data collection and 
thereby to minimize the sound impacts to the marine environment, to 
reduce the area of the survey to only the area necessary for critical 
data collection, and to consider and plan around marine biological 
resources/life functions (such as presence, breeding, feeding, and 
migration) in the survey area.
    PG&E and LDEO are proposing the following mitigation measures to 
reduce the potential effects of the project on southern sea otters 
resulting from air guns and vessel activities:
     PG&E would conduct an aerial survey approximately 1 week 
prior to the start of the seismic survey to obtain pre-survey 
information on the numbers and distribution of southern sea otters in 
the seismic survey area. Weekly aerial surveys would also be conducted 
throughout the survey program. Survey routes would be adjusted as 
feasible to avoid concentrations of sea otters,
     Protected Species Observers (PSOs) (NMFS-certified and 
Service-approved) would be stationed on the primary survey vessel and 
on the support and scout vessels. PSOs would also be present on vessels 
involved in the deployment and recovery of marine geophones,
     PSOs would visually monitor sea otters within the 
designated survey exclusion (180 dB re 1 [mu]Pa) and safety (160dB re 1 
[mu]Pa) zones during all daylight hours,
     If one or more sea otters were observed near the exclusion 
zone and appeared to be about to enter it, avoidance measures would be 
taken, including decreasing vessel speed or implementing a power down,
     If one or more sea otters were observed within the 
exclusion zone, the air gun arrays would be shut down within several 
seconds. The PSO would then maintain a watch to determine when the sea 
otter(s) appeared to be outside the exclusion zone such that air gun 
operations could resume,
     Power-up, ramp-up, and shut-down procedures would be 
implemented during all air gun operations,
     A mitigation air gun (a continuously operated, low-volume, 
single air gun versus all eighteen) would be used during survey turns 
outside of the 3D survey area as well as during power-down and standby 
periods to deter marine wildlife from re-entering the exclusion zone,
     During nighttime operations, whenever the vessel survey 
tracks were located inshore of the 40-meter depth contour (where 
physical encounters with sea otters are more likely), PSOs would 
visually monitor the area forward of the survey vessel with the aid of 
infra-red (night vision) goggles/binoculars and the forward-looking 
infra-red (FLIR) system available onboard the R/V Marcus G. Langseth. 
Mitigation measures, such as avoidance or power-downs/shut-downs, would 
be implemented if a sea otter were detected in the path of the survey 
vessel.

Findings

    The Service proposes the following findings regarding this action:

Small Numbers Determination and Estimated Take by Incidental Harassment

    For small take analysis, the statute and legislative history do not 
expressly require a specific type of numerical analysis, leaving the 
determination of ``small'' to the agency's discretion. Factors 
considered in our small numbers determination include the following:
    (1) The number of southern sea otters inhabiting the proposed 
impact area is

[[Page 59217]]

small relative to the size of the southern sea otter population. The 
number of southern sea otters that could potentially be taken by 
harassment in association with the proposed activity is 352, less than 
13 percent of the estimated population size of 2,792.
    (2) The area where the activity would occur is small relative to 
the range of the southern sea otter. The combined footprint of survey 
box areas 2 and 4 is 631 km\2\ (244 mi\2\) and the portion of this 
combined footprint within sea otter range is 4.7 km\2\ (1.8 mi\2\), 
whereas the southern sea otter range encompasses approximately 1,346 
km\2\ (519.7 mi\2\). Therefore, the survey footprint would affect less 
than 0.4 percent of the total range of the southern sea otter, and 
exposure to the 160 dB sound levels would occur in less than 12 percent 
of the total range of the southern sea otter. Additionally, it should 
be noted that only one circular area, with a radius of approximately 
6.2 km (3.9 mi), would be ensonified to these levels or greater at any 
one time.
    (3) Monitoring requirements and mitigation measures are expected to 
limit the number of incidental takes. Level A harassment (harassment 
that has the potential to injure southern sea otters) is not 
authorized. PSOs would ensure that sea otters are not exposed to sounds 
or activities that may result in Level A harassment. PSOs would be 
present during all daylight survey activities and would have the 
authority to order a power-down or shut-down of the seismic air guns, 
and/or redirect survey activities to avoid observed sea otters if sea 
otters appeared to enter or approach the 180 dB re 1 [mu]Pa exclusion 
zone. If a sea otter were observed within or approaching the 180 dB re 
1 [mu]Pa exposure area of 1,010 m (0.63 mi), avoidance measures would 
be taken, such as decreasing the speed of the vessel and/or 
implementing a power-down or shut-down of the air guns. Nighttime 
monitoring would be conducted with the aid of night-vision binoculars 
and a FLIR system when the R/V Marcus G. Langseth was inshore of the 
40-m (131-ft) depth contour. All nearshore vessel operations associated 
with marine geophone placements would be monitored by PSOs. Power-up 
and ramp-up procedures would prevent Level A harassment and limit the 
number of incidental takes by Level B harassment by affording time for 
sea otters to leave the area. Monitoring and mitigation measures are 
thus expected to prevent any Level A harassment and to minimize Level B 
harassment.
    It should be noted that if sea otters appeared to be undisturbed by 
sound to the extent that the exclusion zone could not be successfully 
kept clear of sea otters, the applicant would have the option to 
request that the Service approve a reduction of the exclusion zone 
radius. We would review the request and notify the applicant of our 
determination. Our approval would not constitute authorization of Level 
A harassment. Rather, our approval would be based on a determination, 
following review of information on sea otter behavior obtained through 
required monitoring during the survey, that a smaller exclusion zone 
would avoid Level A harassment.
Negligible Impact
    The Service finds that any incidental ``take by harassment'' that 
may result from this proposed seismic survey 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, and would, therefore, have no more than a negligible impact 
on the stock. In making this finding, we considered the best available 
scientific information, including (1) The biological and behavioral 
characteristics of the species, (2) the most recent information on 
distribution and abundance of sea otters within the area of the 
proposed activity, (3) the potential sources of short-term disturbance 
during the proposed activity, and (4) the potential response of 
southern sea otters to this short-term disturbance.
    Limited evidence (Riedman 1983, 1984) suggests that sea otters are 
not particularly sensitive to or adversely affected by sound. Responses 
of sea otters to disturbance would most likely be diving and/or 
swimming away from the sound source, which may entail the temporary, 
but not sustained, interruption of foraging, breeding, resting, or 
other natural behaviors. Thus, although 352 sea otters (approximately 
13 percent of the mainland population) are estimated to be potentially 
taken (i.e., potentially disturbed) by Level B harassment by means of 
exposure to sound levels of 160dB re 1 [mu]Pa or greater over the 
duration of the project, we do not expect that this type of harassment 
would result in adverse effects on the species through effects on 
annual rates of recruitment or survival. In order to verify this 
conclusion, we have recommended that an ancillary scientific study be 
conducted during the survey and afterwards to detect effects on 
individual sea otters and any potential changes in annual rates of 
recruitment and survival among sea otters exposed to sound. PG&E and 
LDEO have agreed to arrange, with input from the Service, for this 
study and subsequent analysis (see ``Marine Mammal Monitoring'' below). 
The preliminary results of this study will be included in our analysis 
should the applicant request incidental harassment authorization for 
survey box area 1 in 2013.
    The mitigation measures outlined above are intended to minimize the 
number of sea otters that may be disturbed by the proposed activity. 
Any impacts on individuals are expected to be limited to Level B 
harassment and to be of short-term duration. No take by injury or death 
is anticipated or authorized. Should the Service determine, based on 
the monitoring and reporting to be conducted throughout the survey 
activities, that the effects are greater than anticipated, the 
authorization may be modified, suspended, or revoked.
    Our finding of negligible impact applies to incidental take 
associated with the proposed activity as mitigated through this 
authorization process. This authorization establishes monitoring and 
reporting requirements to evaluate the impacts of the authorized 
activities, as well as mitigation measures designed to minimize 
interactions with, and impacts to, southern sea otters.
Impact on Subsistence
    The subsistence provision of the MMPA does not apply to southern 
sea otters.

Marine Mammal Monitoring

    The applicant would be required to conduct monitoring of southern 
sea otters during the seismic surveys in order to implement the 
mitigation measures that require real-time monitoring and to satisfy 
monitoring required under the MMPA. Project personnel would be required 
to record information regarding location and behavior of all sea otters 
observed during operations. When conditions permitted, information 
regarding age (pup, independent) and tag color and position (for 
flipper-tagged animals) would also be required to be recorded.
    Due to the lack of data on the effects of air guns on sea otters, 
in addition to project-related mitigation monitoring, the Service has 
recommended that PG&E and LDEO use the survey as an opportunity to 
investigate the potential effects of air guns on sea otters. PG&E and 
LDEO have agreed to address this request by arranging, with input from 
the Service, for the design and implementation of an ancillary 
scientific study during and after the survey and subsequent analysis. 
The study would be conducted by

[[Page 59218]]

researchers with the appropriate scientific expertise and permits 
(USGS, Biological Resources Division, in cooperation with the 
California Department of Fish and Game and other research partners). 
The Sea Otter Monitoring Program is described in Appendix E to the 
revised IHA application. To supplement data obtained by researchers 
from bottom-mounted passive acoustic recorders placed in and near kelp 
beds used by resident sea otters, PG&E and LDEO would provide 
researchers with GPS-referenced time data for the air gun shots from 
the seismic survey vessel. These data would be used to validate the 
acoustic modeling underlying the 160 dB re 1 [mu]Pa safety zone and 180 
dB re 1 [mu]Pa exclusion zone radii, to measure the propagation of 
sound through sea otter habitat, and to estimate received sound levels 
that may be useful in determining sea otter behavioral response 
thresholds as a function of sound exposure.

Monitoring and Reporting

    The applicant would be required to implement the following 
monitoring and reporting program to increase knowledge regarding the 
species and to assess the level of take caused by the proposed action:

a. Pre-Activity Monitoring

    Approximately 1 week prior to the start of seismic survey 
operations, an aerial survey would be flown to establish a baseline for 
numbers and distribution of southern sea otters in the project area;

b. Activity Monitoring

    Vessel-based monitoring for marine wildlife, including southern sea 
otters, would be done by trained PSOs throughout the period of survey 
activities. PSO duties would include watching for and identifying 
marine mammals; recording their numbers, distances, and any reactions 
to the survey operations; and documenting potential ``take by 
harassment'' as defined by the Service and NMFS.
    A sufficient number of PSOs would be required onboard the survey 
and support vessels to meet the following criteria:
     100-percent monitoring during all periods of survey 
operations (visual everywhere during daylight and inshore of the 40-m 
contour at night); and
     A maximum of four consecutive hours on watch per PSO.
    PSO teams would consist of Service- and NMFS-approved PSOs and 
experienced field biologists. An experienced crew leader would 
supervise the PSO team onboard the survey vessels. Crew leaders and 
biologists serving as PSOs would be individuals with experience as PSOs 
during high-energy survey projects (HESS), and/or shallow hazards 
surveys in California.
    PSOs would be required to have previous marine mammal observation 
experience, and field crew leaders would be highly experienced with 
previous vessel-based marine mammal monitoring and mitigation projects. 
Resumes for those individuals would be provided to the Service and NMFS 
for review and acceptance of their qualifications. PSOs would be 
familiar with the region and the marine mammals of the area and would 
complete an in-house observer training course designed to familiarize 
individuals with monitoring and data collection procedures.
    The PSOs would watch for marine mammals from the best available 
vantage point on the survey vessels, typically the PSO tower on the R/V 
Marcus G. Langseth, or from dedicated monitoring vessels. The PSOs 
would scan systematically with the unaided eye and with binoculars. 
Personnel on the bridge of the survey and monitoring vessels would 
assist the PSOs in watching for marine mammals.
    Information recorded by PSOs would include:
     Species, group size, age/size/gender (if determinable), 
behavior when first sighted and after initial sighting, heading (if 
determinable), bearing and distance from observer, apparent reaction to 
activities (e.g., none, avoidance, approach, paralleling, etc.), 
closest point of approach, and pace;
     Time, location (GPS coordinates), sea state, visibility, 
sun glare, and speed and activity of the vessel, and
     Positions of other vessel(s) in the vicinity of the 
observer location.
    The ship's position, speed of the vessel, water depth, sea state, 
visibility, and sun glare would also be recorded at the start and end 
of each observation watch, every 30 minutes during a watch, and 
whenever there were substantial changes in any of those variables.
    If a southern sea otter were seen within the exclusion zone, the 
geophysical crew would be notified immediately so that the mitigation 
measures called for in the applicable authorization(s) could be 
implemented. The air gun arrays would be shut down within several 
seconds. The PSO would then maintain a watch to determine when the sea 
otter(s) appeared to be outside the exclusion zone such that air gun 
operations could resume.
    Aerial surveys would be conducted weekly during seismic survey 
operations to assist in the identification and avoidance of southern 
sea otters within the project area;

c. Post-Activity Monitoring

    Approximately 1 week prior to the completion of the offshore 
seismic survey operations, a final aerial survey would be conducted to 
document the number and distribution of southern sea otters in the 
project area. These data would be used in comparison with original 
survey data collected prior to the seismic operations.
    No post-activity monitoring is proposed.

d. Reporting

    Throughout the survey program, PSOs would prepare a report each 
week summarizing the recent results of the monitoring program. The 
reports would summarize the numbers of sea otters sighted. These 
reports would be provided to the Service, PG&E, LDEO, and NSF.
    The results of the vessel-based monitoring, including estimates of 
potential ``take by harassment,'' would be compiled in a report and 
submitted to the Service within 90 days of survey conclusion; the 
report would also be posted on the NSF Web site at: https://www.nsf.gov/geo/oce/envcomp/index.jsp. Reporting would address any requirements 
established by the Service and NMFS.
    Along with any other State or Federal requirements, the 90-day 
report would minimally include:
     Summaries of monitoring effort: Total hours, total 
distances, and distribution of marine mammals through the study period 
accounting for sea state and other factors affecting visibility and 
detectability of marine mammals;
     Analyses of the effects of various factors influencing the 
detectability of marine mammals, including sea state, number of 
observers, and fog/glare;
     Species composition and occurrence, and distribution of 
marine mammal sightings, including date, water depth, numbers, age/
size/gender, and group sizes, and analyses of the effects of survey 
operations;
     Sighting rates of marine mammals during periods with and 
without air gun activities (and other variables that could affect 
detectability);
     Initial sighting distances versus air gun activity state 
(firing, powered down, or shut-down);
     Closest point of approach versus air gun activity state;

[[Page 59219]]

     Observed behaviors and types of movements versus air gun 
activity state;
     Numbers of sightings/individuals seen versus air gun 
activity state;
     Distribution around the survey vessel versus air gun 
activity state; and
     Estimates of ``take by harassment''.

Endangered Species Act

    The southern sea otter is currently listed as threatened under the 
Endangered Species Act of 1973, as amended (ESA). Because the proposed 
activities may affect the southern sea otter, pursuant to section 
7(a)(2) of the ESA, the Service must ensure that its issuance of the 
IHA will not jeopardize the species. In addition, the NSF must ensure 
that its provision of the R/V Marcus G. Langseth will likewise not 
jeopardize the southern sea otter. To address the obligations of both 
the Service and NSF pursuant to section 7(a)(2) of the ESA, the Service 
has initiated internal formal consultation on issuance of an IHA, and 
the NSF has initiated formal consultation with the Service for its 
action of providing the R/V Marcus G. Langseth for the survey. These 
consultations will be addressed in a single biological opinion. The 
biological opinion will consider the effects of the project on the 
southern sea otter, including our issuance of an IHA. The biological 
opinion will be issued prior to the decision on the IHA.

National Environmental Policy Act (NEPA)

    The seismic survey is described in the Draft EA prepared by the 
applicant under the supervision of the NSF, the lead Federal agency. If 
we find it to be adequate and appropriate, we will adopt the Draft EA 
as the Service's Environmental Assessment (EA) of whether issuance of 
the IHA would have a significant effect on the human environment. Our 
analysis will be completed prior to issuance or denial of the IHA and 
will be available at https://www.fws.gov/ventura/speciesinfo/. To obtain 
a copy of the Draft EA, contact the individual identified in the FOR 
FURTHER INFORMATION CONTACT section.

Government-to-Government Relations With Native American Tribal 
Governments

    In accordance with the President's memorandum of April 29, 1994, 
``Government-to-Government Relations with Native American Tribal 
Governments'' (59 FR 22951), Executive Order 13175, Secretarial Order 
3225, and the Department of the Interior's manual at 512 DM 2, we 
readily acknowledge our responsibility to communicate meaningfully with 
Federally recognized Tribes on a Government-to-Government basis. We 
have evaluated possible effects on federally recognized Indian Tribes 
and have determined that there are no effects.

Proposed Authorization

    The Service proposes to issue an IHA for southern sea otters 
harassed incidentally by the applicant in the course of conducting 
seismic surveys beginning October 15, 2012, and ending December 31, 
2012. Mobilization could begin as early as October 15, but sound source 
verification procedures and active air gun surveys would start no 
earlier than November 1. Authorization for incidental take beyond this 
time period would require a new request. The final IHA, if issued, will 
incorporate the mitigation, monitoring, and reporting requirements 
discussed in this proposal. The applicant would be responsible for 
following those requirements. If the level of activity exceeded that 
described by the applicant, or the level or nature of take exceeded 
those projected here, the Service would reevaluate its findings. 
Conversely, if sea otters appeared to be undisturbed by sound to the 
extent that the exclusion zone could not be successfully kept clear of 
sea otters, the applicant would have the option to request that the 
Service approve a reduction of the exclusion zone radius. We would 
review the request and notify the applicant of our determination. The 
Secretary would have the ability to modify, suspend, or revoke this 
authorization if the findings were not accurate or the conditions 
described in this notice were not being met. Should the applicant 
request incidental harassment authorization for survey box area 1 in 
2013, the Service will re-analyze the small numbers and negligible 
impact determinations, which would include an evaluation of the 
information gained through the monitoring and reporting requirements 
proposed in this IHA, and make a new finding at that time.

Request for Public Comments

    The Service requests interested parties to submit comments and 
information concerning this proposed IHA. Consistent with section 
101(a)(5)(D)(iii) of the MMPA, we are opening the comment period on 
this proposed authorization for 30 days (see DATES).
    Before including your address, phone number, email address, or 
other personal identifying information in your comment, you should be 
aware that your entire comment--including your personal identifying 
information--may be made publicly available at any time. While you can 
ask us in your comment to withhold your personal identifying 
information from public review, we cannot guarantee that we will be 
able to do so.

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Alexandra Pitts,
Deputy Regional Director, Pacific Southwest Region.
[FR Doc. 2012-23749 Filed 9-24-12; 11:15 am]
BILLING CODE 4310-55-P